diff.con commit Merge branch 'jk/misc-uninitialized-fixes' (d8ce144)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "config.h"
   6#include "tempfile.h"
   7#include "quote.h"
   8#include "diff.h"
   9#include "diffcore.h"
  10#include "delta.h"
  11#include "xdiff-interface.h"
  12#include "color.h"
  13#include "attr.h"
  14#include "run-command.h"
  15#include "utf8.h"
  16#include "object-store.h"
  17#include "userdiff.h"
  18#include "submodule-config.h"
  19#include "submodule.h"
  20#include "hashmap.h"
  21#include "ll-merge.h"
  22#include "string-list.h"
  23#include "argv-array.h"
  24#include "graph.h"
  25#include "packfile.h"
  26#include "parse-options.h"
  27#include "help.h"
  28#include "promisor-remote.h"
  29
  30#ifdef NO_FAST_WORKING_DIRECTORY
  31#define FAST_WORKING_DIRECTORY 0
  32#else
  33#define FAST_WORKING_DIRECTORY 1
  34#endif
  35
  36static int diff_detect_rename_default;
  37static int diff_indent_heuristic = 1;
  38static int diff_rename_limit_default = 400;
  39static int diff_suppress_blank_empty;
  40static int diff_use_color_default = -1;
  41static int diff_color_moved_default;
  42static int diff_color_moved_ws_default;
  43static int diff_context_default = 3;
  44static int diff_interhunk_context_default;
  45static const char *diff_word_regex_cfg;
  46static const char *external_diff_cmd_cfg;
  47static const char *diff_order_file_cfg;
  48int diff_auto_refresh_index = 1;
  49static int diff_mnemonic_prefix;
  50static int diff_no_prefix;
  51static int diff_stat_graph_width;
  52static int diff_dirstat_permille_default = 30;
  53static struct diff_options default_diff_options;
  54static long diff_algorithm;
  55static unsigned ws_error_highlight_default = WSEH_NEW;
  56
  57static char diff_colors[][COLOR_MAXLEN] = {
  58        GIT_COLOR_RESET,
  59        GIT_COLOR_NORMAL,       /* CONTEXT */
  60        GIT_COLOR_BOLD,         /* METAINFO */
  61        GIT_COLOR_CYAN,         /* FRAGINFO */
  62        GIT_COLOR_RED,          /* OLD */
  63        GIT_COLOR_GREEN,        /* NEW */
  64        GIT_COLOR_YELLOW,       /* COMMIT */
  65        GIT_COLOR_BG_RED,       /* WHITESPACE */
  66        GIT_COLOR_NORMAL,       /* FUNCINFO */
  67        GIT_COLOR_BOLD_MAGENTA, /* OLD_MOVED */
  68        GIT_COLOR_BOLD_BLUE,    /* OLD_MOVED ALTERNATIVE */
  69        GIT_COLOR_FAINT,        /* OLD_MOVED_DIM */
  70        GIT_COLOR_FAINT_ITALIC, /* OLD_MOVED_ALTERNATIVE_DIM */
  71        GIT_COLOR_BOLD_CYAN,    /* NEW_MOVED */
  72        GIT_COLOR_BOLD_YELLOW,  /* NEW_MOVED ALTERNATIVE */
  73        GIT_COLOR_FAINT,        /* NEW_MOVED_DIM */
  74        GIT_COLOR_FAINT_ITALIC, /* NEW_MOVED_ALTERNATIVE_DIM */
  75        GIT_COLOR_FAINT,        /* CONTEXT_DIM */
  76        GIT_COLOR_FAINT_RED,    /* OLD_DIM */
  77        GIT_COLOR_FAINT_GREEN,  /* NEW_DIM */
  78        GIT_COLOR_BOLD,         /* CONTEXT_BOLD */
  79        GIT_COLOR_BOLD_RED,     /* OLD_BOLD */
  80        GIT_COLOR_BOLD_GREEN,   /* NEW_BOLD */
  81};
  82
  83static const char *color_diff_slots[] = {
  84        [DIFF_CONTEXT]                = "context",
  85        [DIFF_METAINFO]               = "meta",
  86        [DIFF_FRAGINFO]               = "frag",
  87        [DIFF_FILE_OLD]               = "old",
  88        [DIFF_FILE_NEW]               = "new",
  89        [DIFF_COMMIT]                 = "commit",
  90        [DIFF_WHITESPACE]             = "whitespace",
  91        [DIFF_FUNCINFO]               = "func",
  92        [DIFF_FILE_OLD_MOVED]         = "oldMoved",
  93        [DIFF_FILE_OLD_MOVED_ALT]     = "oldMovedAlternative",
  94        [DIFF_FILE_OLD_MOVED_DIM]     = "oldMovedDimmed",
  95        [DIFF_FILE_OLD_MOVED_ALT_DIM] = "oldMovedAlternativeDimmed",
  96        [DIFF_FILE_NEW_MOVED]         = "newMoved",
  97        [DIFF_FILE_NEW_MOVED_ALT]     = "newMovedAlternative",
  98        [DIFF_FILE_NEW_MOVED_DIM]     = "newMovedDimmed",
  99        [DIFF_FILE_NEW_MOVED_ALT_DIM] = "newMovedAlternativeDimmed",
 100        [DIFF_CONTEXT_DIM]            = "contextDimmed",
 101        [DIFF_FILE_OLD_DIM]           = "oldDimmed",
 102        [DIFF_FILE_NEW_DIM]           = "newDimmed",
 103        [DIFF_CONTEXT_BOLD]           = "contextBold",
 104        [DIFF_FILE_OLD_BOLD]          = "oldBold",
 105        [DIFF_FILE_NEW_BOLD]          = "newBold",
 106};
 107
 108define_list_config_array_extra(color_diff_slots, {"plain"});
 109
 110static int parse_diff_color_slot(const char *var)
 111{
 112        if (!strcasecmp(var, "plain"))
 113                return DIFF_CONTEXT;
 114        return LOOKUP_CONFIG(color_diff_slots, var);
 115}
 116
 117static int parse_dirstat_params(struct diff_options *options, const char *params_string,
 118                                struct strbuf *errmsg)
 119{
 120        char *params_copy = xstrdup(params_string);
 121        struct string_list params = STRING_LIST_INIT_NODUP;
 122        int ret = 0;
 123        int i;
 124
 125        if (*params_copy)
 126                string_list_split_in_place(&params, params_copy, ',', -1);
 127        for (i = 0; i < params.nr; i++) {
 128                const char *p = params.items[i].string;
 129                if (!strcmp(p, "changes")) {
 130                        options->flags.dirstat_by_line = 0;
 131                        options->flags.dirstat_by_file = 0;
 132                } else if (!strcmp(p, "lines")) {
 133                        options->flags.dirstat_by_line = 1;
 134                        options->flags.dirstat_by_file = 0;
 135                } else if (!strcmp(p, "files")) {
 136                        options->flags.dirstat_by_line = 0;
 137                        options->flags.dirstat_by_file = 1;
 138                } else if (!strcmp(p, "noncumulative")) {
 139                        options->flags.dirstat_cumulative = 0;
 140                } else if (!strcmp(p, "cumulative")) {
 141                        options->flags.dirstat_cumulative = 1;
 142                } else if (isdigit(*p)) {
 143                        char *end;
 144                        int permille = strtoul(p, &end, 10) * 10;
 145                        if (*end == '.' && isdigit(*++end)) {
 146                                /* only use first digit */
 147                                permille += *end - '0';
 148                                /* .. and ignore any further digits */
 149                                while (isdigit(*++end))
 150                                        ; /* nothing */
 151                        }
 152                        if (!*end)
 153                                options->dirstat_permille = permille;
 154                        else {
 155                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 156                                            p);
 157                                ret++;
 158                        }
 159                } else {
 160                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 161                        ret++;
 162                }
 163
 164        }
 165        string_list_clear(&params, 0);
 166        free(params_copy);
 167        return ret;
 168}
 169
 170static int parse_submodule_params(struct diff_options *options, const char *value)
 171{
 172        if (!strcmp(value, "log"))
 173                options->submodule_format = DIFF_SUBMODULE_LOG;
 174        else if (!strcmp(value, "short"))
 175                options->submodule_format = DIFF_SUBMODULE_SHORT;
 176        else if (!strcmp(value, "diff"))
 177                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 178        /*
 179         * Please update $__git_diff_submodule_formats in
 180         * git-completion.bash when you add new formats.
 181         */
 182        else
 183                return -1;
 184        return 0;
 185}
 186
 187int git_config_rename(const char *var, const char *value)
 188{
 189        if (!value)
 190                return DIFF_DETECT_RENAME;
 191        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 192                return  DIFF_DETECT_COPY;
 193        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 194}
 195
 196long parse_algorithm_value(const char *value)
 197{
 198        if (!value)
 199                return -1;
 200        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 201                return 0;
 202        else if (!strcasecmp(value, "minimal"))
 203                return XDF_NEED_MINIMAL;
 204        else if (!strcasecmp(value, "patience"))
 205                return XDF_PATIENCE_DIFF;
 206        else if (!strcasecmp(value, "histogram"))
 207                return XDF_HISTOGRAM_DIFF;
 208        /*
 209         * Please update $__git_diff_algorithms in git-completion.bash
 210         * when you add new algorithms.
 211         */
 212        return -1;
 213}
 214
 215static int parse_one_token(const char **arg, const char *token)
 216{
 217        const char *rest;
 218        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 219                *arg = rest;
 220                return 1;
 221        }
 222        return 0;
 223}
 224
 225static int parse_ws_error_highlight(const char *arg)
 226{
 227        const char *orig_arg = arg;
 228        unsigned val = 0;
 229
 230        while (*arg) {
 231                if (parse_one_token(&arg, "none"))
 232                        val = 0;
 233                else if (parse_one_token(&arg, "default"))
 234                        val = WSEH_NEW;
 235                else if (parse_one_token(&arg, "all"))
 236                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 237                else if (parse_one_token(&arg, "new"))
 238                        val |= WSEH_NEW;
 239                else if (parse_one_token(&arg, "old"))
 240                        val |= WSEH_OLD;
 241                else if (parse_one_token(&arg, "context"))
 242                        val |= WSEH_CONTEXT;
 243                else {
 244                        return -1 - (int)(arg - orig_arg);
 245                }
 246                if (*arg)
 247                        arg++;
 248        }
 249        return val;
 250}
 251
 252/*
 253 * These are to give UI layer defaults.
 254 * The core-level commands such as git-diff-files should
 255 * never be affected by the setting of diff.renames
 256 * the user happens to have in the configuration file.
 257 */
 258void init_diff_ui_defaults(void)
 259{
 260        diff_detect_rename_default = DIFF_DETECT_RENAME;
 261}
 262
 263int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 264{
 265        if (!strcmp(var, "diff.indentheuristic"))
 266                diff_indent_heuristic = git_config_bool(var, value);
 267        return 0;
 268}
 269
 270static int parse_color_moved(const char *arg)
 271{
 272        switch (git_parse_maybe_bool(arg)) {
 273        case 0:
 274                return COLOR_MOVED_NO;
 275        case 1:
 276                return COLOR_MOVED_DEFAULT;
 277        default:
 278                break;
 279        }
 280
 281        if (!strcmp(arg, "no"))
 282                return COLOR_MOVED_NO;
 283        else if (!strcmp(arg, "plain"))
 284                return COLOR_MOVED_PLAIN;
 285        else if (!strcmp(arg, "blocks"))
 286                return COLOR_MOVED_BLOCKS;
 287        else if (!strcmp(arg, "zebra"))
 288                return COLOR_MOVED_ZEBRA;
 289        else if (!strcmp(arg, "default"))
 290                return COLOR_MOVED_DEFAULT;
 291        else if (!strcmp(arg, "dimmed-zebra"))
 292                return COLOR_MOVED_ZEBRA_DIM;
 293        else if (!strcmp(arg, "dimmed_zebra"))
 294                return COLOR_MOVED_ZEBRA_DIM;
 295        else
 296                return error(_("color moved setting must be one of 'no', 'default', 'blocks', 'zebra', 'dimmed-zebra', 'plain'"));
 297}
 298
 299static unsigned parse_color_moved_ws(const char *arg)
 300{
 301        int ret = 0;
 302        struct string_list l = STRING_LIST_INIT_DUP;
 303        struct string_list_item *i;
 304
 305        string_list_split(&l, arg, ',', -1);
 306
 307        for_each_string_list_item(i, &l) {
 308                struct strbuf sb = STRBUF_INIT;
 309                strbuf_addstr(&sb, i->string);
 310                strbuf_trim(&sb);
 311
 312                if (!strcmp(sb.buf, "no"))
 313                        ret = 0;
 314                else if (!strcmp(sb.buf, "ignore-space-change"))
 315                        ret |= XDF_IGNORE_WHITESPACE_CHANGE;
 316                else if (!strcmp(sb.buf, "ignore-space-at-eol"))
 317                        ret |= XDF_IGNORE_WHITESPACE_AT_EOL;
 318                else if (!strcmp(sb.buf, "ignore-all-space"))
 319                        ret |= XDF_IGNORE_WHITESPACE;
 320                else if (!strcmp(sb.buf, "allow-indentation-change"))
 321                        ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
 322                else {
 323                        ret |= COLOR_MOVED_WS_ERROR;
 324                        error(_("unknown color-moved-ws mode '%s', possible values are 'ignore-space-change', 'ignore-space-at-eol', 'ignore-all-space', 'allow-indentation-change'"), sb.buf);
 325                }
 326
 327                strbuf_release(&sb);
 328        }
 329
 330        if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
 331            (ret & XDF_WHITESPACE_FLAGS)) {
 332                error(_("color-moved-ws: allow-indentation-change cannot be combined with other whitespace modes"));
 333                ret |= COLOR_MOVED_WS_ERROR;
 334        }
 335
 336        string_list_clear(&l, 0);
 337
 338        return ret;
 339}
 340
 341int git_diff_ui_config(const char *var, const char *value, void *cb)
 342{
 343        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 344                diff_use_color_default = git_config_colorbool(var, value);
 345                return 0;
 346        }
 347        if (!strcmp(var, "diff.colormoved")) {
 348                int cm = parse_color_moved(value);
 349                if (cm < 0)
 350                        return -1;
 351                diff_color_moved_default = cm;
 352                return 0;
 353        }
 354        if (!strcmp(var, "diff.colormovedws")) {
 355                unsigned cm = parse_color_moved_ws(value);
 356                if (cm & COLOR_MOVED_WS_ERROR)
 357                        return -1;
 358                diff_color_moved_ws_default = cm;
 359                return 0;
 360        }
 361        if (!strcmp(var, "diff.context")) {
 362                diff_context_default = git_config_int(var, value);
 363                if (diff_context_default < 0)
 364                        return -1;
 365                return 0;
 366        }
 367        if (!strcmp(var, "diff.interhunkcontext")) {
 368                diff_interhunk_context_default = git_config_int(var, value);
 369                if (diff_interhunk_context_default < 0)
 370                        return -1;
 371                return 0;
 372        }
 373        if (!strcmp(var, "diff.renames")) {
 374                diff_detect_rename_default = git_config_rename(var, value);
 375                return 0;
 376        }
 377        if (!strcmp(var, "diff.autorefreshindex")) {
 378                diff_auto_refresh_index = git_config_bool(var, value);
 379                return 0;
 380        }
 381        if (!strcmp(var, "diff.mnemonicprefix")) {
 382                diff_mnemonic_prefix = git_config_bool(var, value);
 383                return 0;
 384        }
 385        if (!strcmp(var, "diff.noprefix")) {
 386                diff_no_prefix = git_config_bool(var, value);
 387                return 0;
 388        }
 389        if (!strcmp(var, "diff.statgraphwidth")) {
 390                diff_stat_graph_width = git_config_int(var, value);
 391                return 0;
 392        }
 393        if (!strcmp(var, "diff.external"))
 394                return git_config_string(&external_diff_cmd_cfg, var, value);
 395        if (!strcmp(var, "diff.wordregex"))
 396                return git_config_string(&diff_word_regex_cfg, var, value);
 397        if (!strcmp(var, "diff.orderfile"))
 398                return git_config_pathname(&diff_order_file_cfg, var, value);
 399
 400        if (!strcmp(var, "diff.ignoresubmodules"))
 401                handle_ignore_submodules_arg(&default_diff_options, value);
 402
 403        if (!strcmp(var, "diff.submodule")) {
 404                if (parse_submodule_params(&default_diff_options, value))
 405                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 406                                value);
 407                return 0;
 408        }
 409
 410        if (!strcmp(var, "diff.algorithm")) {
 411                diff_algorithm = parse_algorithm_value(value);
 412                if (diff_algorithm < 0)
 413                        return -1;
 414                return 0;
 415        }
 416
 417        if (!strcmp(var, "diff.wserrorhighlight")) {
 418                int val = parse_ws_error_highlight(value);
 419                if (val < 0)
 420                        return -1;
 421                ws_error_highlight_default = val;
 422                return 0;
 423        }
 424
 425        if (git_color_config(var, value, cb) < 0)
 426                return -1;
 427
 428        return git_diff_basic_config(var, value, cb);
 429}
 430
 431int git_diff_basic_config(const char *var, const char *value, void *cb)
 432{
 433        const char *name;
 434
 435        if (!strcmp(var, "diff.renamelimit")) {
 436                diff_rename_limit_default = git_config_int(var, value);
 437                return 0;
 438        }
 439
 440        if (userdiff_config(var, value) < 0)
 441                return -1;
 442
 443        if (skip_prefix(var, "diff.color.", &name) ||
 444            skip_prefix(var, "color.diff.", &name)) {
 445                int slot = parse_diff_color_slot(name);
 446                if (slot < 0)
 447                        return 0;
 448                if (!value)
 449                        return config_error_nonbool(var);
 450                return color_parse(value, diff_colors[slot]);
 451        }
 452
 453        /* like GNU diff's --suppress-blank-empty option  */
 454        if (!strcmp(var, "diff.suppressblankempty") ||
 455                        /* for backwards compatibility */
 456                        !strcmp(var, "diff.suppress-blank-empty")) {
 457                diff_suppress_blank_empty = git_config_bool(var, value);
 458                return 0;
 459        }
 460
 461        if (!strcmp(var, "diff.dirstat")) {
 462                struct strbuf errmsg = STRBUF_INIT;
 463                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 464                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 465                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 466                                errmsg.buf);
 467                strbuf_release(&errmsg);
 468                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 469                return 0;
 470        }
 471
 472        if (git_diff_heuristic_config(var, value, cb) < 0)
 473                return -1;
 474
 475        return git_default_config(var, value, cb);
 476}
 477
 478static char *quote_two(const char *one, const char *two)
 479{
 480        int need_one = quote_c_style(one, NULL, NULL, 1);
 481        int need_two = quote_c_style(two, NULL, NULL, 1);
 482        struct strbuf res = STRBUF_INIT;
 483
 484        if (need_one + need_two) {
 485                strbuf_addch(&res, '"');
 486                quote_c_style(one, &res, NULL, 1);
 487                quote_c_style(two, &res, NULL, 1);
 488                strbuf_addch(&res, '"');
 489        } else {
 490                strbuf_addstr(&res, one);
 491                strbuf_addstr(&res, two);
 492        }
 493        return strbuf_detach(&res, NULL);
 494}
 495
 496static const char *external_diff(void)
 497{
 498        static const char *external_diff_cmd = NULL;
 499        static int done_preparing = 0;
 500
 501        if (done_preparing)
 502                return external_diff_cmd;
 503        external_diff_cmd = xstrdup_or_null(getenv("GIT_EXTERNAL_DIFF"));
 504        if (!external_diff_cmd)
 505                external_diff_cmd = external_diff_cmd_cfg;
 506        done_preparing = 1;
 507        return external_diff_cmd;
 508}
 509
 510/*
 511 * Keep track of files used for diffing. Sometimes such an entry
 512 * refers to a temporary file, sometimes to an existing file, and
 513 * sometimes to "/dev/null".
 514 */
 515static struct diff_tempfile {
 516        /*
 517         * filename external diff should read from, or NULL if this
 518         * entry is currently not in use:
 519         */
 520        const char *name;
 521
 522        char hex[GIT_MAX_HEXSZ + 1];
 523        char mode[10];
 524
 525        /*
 526         * If this diff_tempfile instance refers to a temporary file,
 527         * this tempfile object is used to manage its lifetime.
 528         */
 529        struct tempfile *tempfile;
 530} diff_temp[2];
 531
 532struct emit_callback {
 533        int color_diff;
 534        unsigned ws_rule;
 535        int blank_at_eof_in_preimage;
 536        int blank_at_eof_in_postimage;
 537        int lno_in_preimage;
 538        int lno_in_postimage;
 539        const char **label_path;
 540        struct diff_words_data *diff_words;
 541        struct diff_options *opt;
 542        struct strbuf *header;
 543};
 544
 545static int count_lines(const char *data, int size)
 546{
 547        int count, ch, completely_empty = 1, nl_just_seen = 0;
 548        count = 0;
 549        while (0 < size--) {
 550                ch = *data++;
 551                if (ch == '\n') {
 552                        count++;
 553                        nl_just_seen = 1;
 554                        completely_empty = 0;
 555                }
 556                else {
 557                        nl_just_seen = 0;
 558                        completely_empty = 0;
 559                }
 560        }
 561        if (completely_empty)
 562                return 0;
 563        if (!nl_just_seen)
 564                count++; /* no trailing newline */
 565        return count;
 566}
 567
 568static int fill_mmfile(struct repository *r, mmfile_t *mf,
 569                       struct diff_filespec *one)
 570{
 571        if (!DIFF_FILE_VALID(one)) {
 572                mf->ptr = (char *)""; /* does not matter */
 573                mf->size = 0;
 574                return 0;
 575        }
 576        else if (diff_populate_filespec(r, one, 0))
 577                return -1;
 578
 579        mf->ptr = one->data;
 580        mf->size = one->size;
 581        return 0;
 582}
 583
 584/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 585static unsigned long diff_filespec_size(struct repository *r,
 586                                        struct diff_filespec *one)
 587{
 588        if (!DIFF_FILE_VALID(one))
 589                return 0;
 590        diff_populate_filespec(r, one, CHECK_SIZE_ONLY);
 591        return one->size;
 592}
 593
 594static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 595{
 596        char *ptr = mf->ptr;
 597        long size = mf->size;
 598        int cnt = 0;
 599
 600        if (!size)
 601                return cnt;
 602        ptr += size - 1; /* pointing at the very end */
 603        if (*ptr != '\n')
 604                ; /* incomplete line */
 605        else
 606                ptr--; /* skip the last LF */
 607        while (mf->ptr < ptr) {
 608                char *prev_eol;
 609                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 610                        if (*prev_eol == '\n')
 611                                break;
 612                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 613                        break;
 614                cnt++;
 615                ptr = prev_eol - 1;
 616        }
 617        return cnt;
 618}
 619
 620static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 621                               struct emit_callback *ecbdata)
 622{
 623        int l1, l2, at;
 624        unsigned ws_rule = ecbdata->ws_rule;
 625        l1 = count_trailing_blank(mf1, ws_rule);
 626        l2 = count_trailing_blank(mf2, ws_rule);
 627        if (l2 <= l1) {
 628                ecbdata->blank_at_eof_in_preimage = 0;
 629                ecbdata->blank_at_eof_in_postimage = 0;
 630                return;
 631        }
 632        at = count_lines(mf1->ptr, mf1->size);
 633        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 634
 635        at = count_lines(mf2->ptr, mf2->size);
 636        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 637}
 638
 639static void emit_line_0(struct diff_options *o,
 640                        const char *set_sign, const char *set, unsigned reverse, const char *reset,
 641                        int first, const char *line, int len)
 642{
 643        int has_trailing_newline, has_trailing_carriage_return;
 644        int needs_reset = 0; /* at the end of the line */
 645        FILE *file = o->file;
 646
 647        fputs(diff_line_prefix(o), file);
 648
 649        has_trailing_newline = (len > 0 && line[len-1] == '\n');
 650        if (has_trailing_newline)
 651                len--;
 652
 653        has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 654        if (has_trailing_carriage_return)
 655                len--;
 656
 657        if (!len && !first)
 658                goto end_of_line;
 659
 660        if (reverse && want_color(o->use_color)) {
 661                fputs(GIT_COLOR_REVERSE, file);
 662                needs_reset = 1;
 663        }
 664
 665        if (set_sign) {
 666                fputs(set_sign, file);
 667                needs_reset = 1;
 668        }
 669
 670        if (first)
 671                fputc(first, file);
 672
 673        if (!len)
 674                goto end_of_line;
 675
 676        if (set) {
 677                if (set_sign && set != set_sign)
 678                        fputs(reset, file);
 679                fputs(set, file);
 680                needs_reset = 1;
 681        }
 682        fwrite(line, len, 1, file);
 683        needs_reset = 1; /* 'line' may contain color codes. */
 684
 685end_of_line:
 686        if (needs_reset)
 687                fputs(reset, file);
 688        if (has_trailing_carriage_return)
 689                fputc('\r', file);
 690        if (has_trailing_newline)
 691                fputc('\n', file);
 692}
 693
 694static void emit_line(struct diff_options *o, const char *set, const char *reset,
 695                      const char *line, int len)
 696{
 697        emit_line_0(o, set, NULL, 0, reset, 0, line, len);
 698}
 699
 700enum diff_symbol {
 701        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 702        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 703        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 704        DIFF_SYMBOL_BINARY_DIFF_BODY,
 705        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 706        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 707        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 708        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 709        DIFF_SYMBOL_STATS_LINE,
 710        DIFF_SYMBOL_WORD_DIFF,
 711        DIFF_SYMBOL_STAT_SEP,
 712        DIFF_SYMBOL_SUMMARY,
 713        DIFF_SYMBOL_SUBMODULE_ADD,
 714        DIFF_SYMBOL_SUBMODULE_DEL,
 715        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 716        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 717        DIFF_SYMBOL_SUBMODULE_HEADER,
 718        DIFF_SYMBOL_SUBMODULE_ERROR,
 719        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 720        DIFF_SYMBOL_REWRITE_DIFF,
 721        DIFF_SYMBOL_BINARY_FILES,
 722        DIFF_SYMBOL_HEADER,
 723        DIFF_SYMBOL_FILEPAIR_PLUS,
 724        DIFF_SYMBOL_FILEPAIR_MINUS,
 725        DIFF_SYMBOL_WORDS_PORCELAIN,
 726        DIFF_SYMBOL_WORDS,
 727        DIFF_SYMBOL_CONTEXT,
 728        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 729        DIFF_SYMBOL_PLUS,
 730        DIFF_SYMBOL_MINUS,
 731        DIFF_SYMBOL_NO_LF_EOF,
 732        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 733        DIFF_SYMBOL_CONTEXT_MARKER,
 734        DIFF_SYMBOL_SEPARATOR
 735};
 736/*
 737 * Flags for content lines:
 738 * 0..12 are whitespace rules
 739 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 740 * 16 is marking if the line is blank at EOF
 741 */
 742#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 743#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 744#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 745#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 746#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 747
 748/*
 749 * This struct is used when we need to buffer the output of the diff output.
 750 *
 751 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 752 * into the pre/post image file. This pointer could be a union with the
 753 * line pointer. By storing an offset into the file instead of the literal line,
 754 * we can decrease the memory footprint for the buffered output. At first we
 755 * may want to only have indirection for the content lines, but we could also
 756 * enhance the state for emitting prefabricated lines, e.g. the similarity
 757 * score line or hunk/file headers would only need to store a number or path
 758 * and then the output can be constructed later on depending on state.
 759 */
 760struct emitted_diff_symbol {
 761        const char *line;
 762        int len;
 763        int flags;
 764        int indent_off;   /* Offset to first non-whitespace character */
 765        int indent_width; /* The visual width of the indentation */
 766        enum diff_symbol s;
 767};
 768#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 769
 770struct emitted_diff_symbols {
 771        struct emitted_diff_symbol *buf;
 772        int nr, alloc;
 773};
 774#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 775
 776static void append_emitted_diff_symbol(struct diff_options *o,
 777                                       struct emitted_diff_symbol *e)
 778{
 779        struct emitted_diff_symbol *f;
 780
 781        ALLOC_GROW(o->emitted_symbols->buf,
 782                   o->emitted_symbols->nr + 1,
 783                   o->emitted_symbols->alloc);
 784        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 785
 786        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 787        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 788}
 789
 790struct moved_entry {
 791        struct hashmap_entry ent;
 792        const struct emitted_diff_symbol *es;
 793        struct moved_entry *next_line;
 794};
 795
 796struct moved_block {
 797        struct moved_entry *match;
 798        int wsd; /* The whitespace delta of this block */
 799};
 800
 801static void moved_block_clear(struct moved_block *b)
 802{
 803        memset(b, 0, sizeof(*b));
 804}
 805
 806#define INDENT_BLANKLINE INT_MIN
 807
 808static void fill_es_indent_data(struct emitted_diff_symbol *es)
 809{
 810        unsigned int off = 0, i;
 811        int width = 0, tab_width = es->flags & WS_TAB_WIDTH_MASK;
 812        const char *s = es->line;
 813        const int len = es->len;
 814
 815        /* skip any \v \f \r at start of indentation */
 816        while (s[off] == '\f' || s[off] == '\v' ||
 817               (s[off] == '\r' && off < len - 1))
 818                off++;
 819
 820        /* calculate the visual width of indentation */
 821        while(1) {
 822                if (s[off] == ' ') {
 823                        width++;
 824                        off++;
 825                } else if (s[off] == '\t') {
 826                        width += tab_width - (width % tab_width);
 827                        while (s[++off] == '\t')
 828                                width += tab_width;
 829                } else {
 830                        break;
 831                }
 832        }
 833
 834        /* check if this line is blank */
 835        for (i = off; i < len; i++)
 836                if (!isspace(s[i]))
 837                    break;
 838
 839        if (i == len) {
 840                es->indent_width = INDENT_BLANKLINE;
 841                es->indent_off = len;
 842        } else {
 843                es->indent_off = off;
 844                es->indent_width = width;
 845        }
 846}
 847
 848static int compute_ws_delta(const struct emitted_diff_symbol *a,
 849                            const struct emitted_diff_symbol *b,
 850                            int *out)
 851{
 852        int a_len = a->len,
 853            b_len = b->len,
 854            a_off = a->indent_off,
 855            a_width = a->indent_width,
 856            b_off = b->indent_off,
 857            b_width = b->indent_width;
 858        int delta;
 859
 860        if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE) {
 861                *out = INDENT_BLANKLINE;
 862                return 1;
 863        }
 864
 865        if (a->s == DIFF_SYMBOL_PLUS)
 866                delta = a_width - b_width;
 867        else
 868                delta = b_width - a_width;
 869
 870        if (a_len - a_off != b_len - b_off ||
 871            memcmp(a->line + a_off, b->line + b_off, a_len - a_off))
 872                return 0;
 873
 874        *out = delta;
 875
 876        return 1;
 877}
 878
 879static int cmp_in_block_with_wsd(const struct diff_options *o,
 880                                 const struct moved_entry *cur,
 881                                 const struct moved_entry *match,
 882                                 struct moved_block *pmb,
 883                                 int n)
 884{
 885        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 886        int al = cur->es->len, bl = match->es->len, cl = l->len;
 887        const char *a = cur->es->line,
 888                   *b = match->es->line,
 889                   *c = l->line;
 890        int a_off = cur->es->indent_off,
 891            a_width = cur->es->indent_width,
 892            c_off = l->indent_off,
 893            c_width = l->indent_width;
 894        int delta;
 895
 896        /*
 897         * We need to check if 'cur' is equal to 'match'.  As those
 898         * are from the same (+/-) side, we do not need to adjust for
 899         * indent changes. However these were found using fuzzy
 900         * matching so we do have to check if they are equal. Here we
 901         * just check the lengths. We delay calling memcmp() to check
 902         * the contents until later as if the length comparison for a
 903         * and c fails we can avoid the call all together.
 904         */
 905        if (al != bl)
 906                return 1;
 907
 908        /* If 'l' and 'cur' are both blank then they match. */
 909        if (a_width == INDENT_BLANKLINE && c_width == INDENT_BLANKLINE)
 910                return 0;
 911
 912        /*
 913         * The indent changes of the block are known and stored in pmb->wsd;
 914         * however we need to check if the indent changes of the current line
 915         * match those of the current block and that the text of 'l' and 'cur'
 916         * after the indentation match.
 917         */
 918        if (cur->es->s == DIFF_SYMBOL_PLUS)
 919                delta = a_width - c_width;
 920        else
 921                delta = c_width - a_width;
 922
 923        /*
 924         * If the previous lines of this block were all blank then set its
 925         * whitespace delta.
 926         */
 927        if (pmb->wsd == INDENT_BLANKLINE)
 928                pmb->wsd = delta;
 929
 930        return !(delta == pmb->wsd && al - a_off == cl - c_off &&
 931                 !memcmp(a, b, al) && !
 932                 memcmp(a + a_off, c + c_off, al - a_off));
 933}
 934
 935static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 936                           const void *entry,
 937                           const void *entry_or_key,
 938                           const void *keydata)
 939{
 940        const struct diff_options *diffopt = hashmap_cmp_fn_data;
 941        const struct moved_entry *a = entry;
 942        const struct moved_entry *b = entry_or_key;
 943        unsigned flags = diffopt->color_moved_ws_handling
 944                         & XDF_WHITESPACE_FLAGS;
 945
 946        if (diffopt->color_moved_ws_handling &
 947            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 948                /*
 949                 * As there is not specific white space config given,
 950                 * we'd need to check for a new block, so ignore all
 951                 * white space. The setup of the white space
 952                 * configuration for the next block is done else where
 953                 */
 954                flags |= XDF_IGNORE_WHITESPACE;
 955
 956        return !xdiff_compare_lines(a->es->line, a->es->len,
 957                                    b->es->line, b->es->len,
 958                                    flags);
 959}
 960
 961static struct moved_entry *prepare_entry(struct diff_options *o,
 962                                         int line_no)
 963{
 964        struct moved_entry *ret = xmalloc(sizeof(*ret));
 965        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 966        unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 967
 968        ret->ent.hash = xdiff_hash_string(l->line, l->len, flags);
 969        ret->es = l;
 970        ret->next_line = NULL;
 971
 972        return ret;
 973}
 974
 975static void add_lines_to_move_detection(struct diff_options *o,
 976                                        struct hashmap *add_lines,
 977                                        struct hashmap *del_lines)
 978{
 979        struct moved_entry *prev_line = NULL;
 980
 981        int n;
 982        for (n = 0; n < o->emitted_symbols->nr; n++) {
 983                struct hashmap *hm;
 984                struct moved_entry *key;
 985
 986                switch (o->emitted_symbols->buf[n].s) {
 987                case DIFF_SYMBOL_PLUS:
 988                        hm = add_lines;
 989                        break;
 990                case DIFF_SYMBOL_MINUS:
 991                        hm = del_lines;
 992                        break;
 993                default:
 994                        prev_line = NULL;
 995                        continue;
 996                }
 997
 998                if (o->color_moved_ws_handling &
 999                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1000                        fill_es_indent_data(&o->emitted_symbols->buf[n]);
1001                key = prepare_entry(o, n);
1002                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
1003                        prev_line->next_line = key;
1004
1005                hashmap_add(hm, key);
1006                prev_line = key;
1007        }
1008}
1009
1010static void pmb_advance_or_null(struct diff_options *o,
1011                                struct moved_entry *match,
1012                                struct hashmap *hm,
1013                                struct moved_block *pmb,
1014                                int pmb_nr)
1015{
1016        int i;
1017        for (i = 0; i < pmb_nr; i++) {
1018                struct moved_entry *prev = pmb[i].match;
1019                struct moved_entry *cur = (prev && prev->next_line) ?
1020                                prev->next_line : NULL;
1021                if (cur && !hm->cmpfn(o, cur, match, NULL)) {
1022                        pmb[i].match = cur;
1023                } else {
1024                        pmb[i].match = NULL;
1025                }
1026        }
1027}
1028
1029static void pmb_advance_or_null_multi_match(struct diff_options *o,
1030                                            struct moved_entry *match,
1031                                            struct hashmap *hm,
1032                                            struct moved_block *pmb,
1033                                            int pmb_nr, int n)
1034{
1035        int i;
1036        char *got_match = xcalloc(1, pmb_nr);
1037
1038        for (; match; match = hashmap_get_next(hm, match)) {
1039                for (i = 0; i < pmb_nr; i++) {
1040                        struct moved_entry *prev = pmb[i].match;
1041                        struct moved_entry *cur = (prev && prev->next_line) ?
1042                                        prev->next_line : NULL;
1043                        if (!cur)
1044                                continue;
1045                        if (!cmp_in_block_with_wsd(o, cur, match, &pmb[i], n))
1046                                got_match[i] |= 1;
1047                }
1048        }
1049
1050        for (i = 0; i < pmb_nr; i++) {
1051                if (got_match[i]) {
1052                        /* Advance to the next line */
1053                        pmb[i].match = pmb[i].match->next_line;
1054                } else {
1055                        moved_block_clear(&pmb[i]);
1056                }
1057        }
1058
1059        free(got_match);
1060}
1061
1062static int shrink_potential_moved_blocks(struct moved_block *pmb,
1063                                         int pmb_nr)
1064{
1065        int lp, rp;
1066
1067        /* Shrink the set of potential block to the remaining running */
1068        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
1069                while (lp < pmb_nr && pmb[lp].match)
1070                        lp++;
1071                /* lp points at the first NULL now */
1072
1073                while (rp > -1 && !pmb[rp].match)
1074                        rp--;
1075                /* rp points at the last non-NULL */
1076
1077                if (lp < pmb_nr && rp > -1 && lp < rp) {
1078                        pmb[lp] = pmb[rp];
1079                        memset(&pmb[rp], 0, sizeof(pmb[rp]));
1080                        rp--;
1081                        lp++;
1082                }
1083        }
1084
1085        /* Remember the number of running sets */
1086        return rp + 1;
1087}
1088
1089/*
1090 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
1091 *
1092 * Otherwise, if the last block has fewer alphanumeric characters than
1093 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
1094 * that block.
1095 *
1096 * The last block consists of the (n - block_length)'th line up to but not
1097 * including the nth line.
1098 *
1099 * Returns 0 if the last block is empty or is unset by this function, non zero
1100 * otherwise.
1101 *
1102 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
1103 * Think of a way to unify them.
1104 */
1105static int adjust_last_block(struct diff_options *o, int n, int block_length)
1106{
1107        int i, alnum_count = 0;
1108        if (o->color_moved == COLOR_MOVED_PLAIN)
1109                return block_length;
1110        for (i = 1; i < block_length + 1; i++) {
1111                const char *c = o->emitted_symbols->buf[n - i].line;
1112                for (; *c; c++) {
1113                        if (!isalnum(*c))
1114                                continue;
1115                        alnum_count++;
1116                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
1117                                return 1;
1118                }
1119        }
1120        for (i = 1; i < block_length + 1; i++)
1121                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
1122        return 0;
1123}
1124
1125/* Find blocks of moved code, delegate actual coloring decision to helper */
1126static void mark_color_as_moved(struct diff_options *o,
1127                                struct hashmap *add_lines,
1128                                struct hashmap *del_lines)
1129{
1130        struct moved_block *pmb = NULL; /* potentially moved blocks */
1131        int pmb_nr = 0, pmb_alloc = 0;
1132        int n, flipped_block = 0, block_length = 0;
1133
1134
1135        for (n = 0; n < o->emitted_symbols->nr; n++) {
1136                struct hashmap *hm = NULL;
1137                struct moved_entry *key;
1138                struct moved_entry *match = NULL;
1139                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1140                enum diff_symbol last_symbol = 0;
1141
1142                switch (l->s) {
1143                case DIFF_SYMBOL_PLUS:
1144                        hm = del_lines;
1145                        key = prepare_entry(o, n);
1146                        match = hashmap_get(hm, key, NULL);
1147                        free(key);
1148                        break;
1149                case DIFF_SYMBOL_MINUS:
1150                        hm = add_lines;
1151                        key = prepare_entry(o, n);
1152                        match = hashmap_get(hm, key, NULL);
1153                        free(key);
1154                        break;
1155                default:
1156                        flipped_block = 0;
1157                }
1158
1159                if (!match) {
1160                        int i;
1161
1162                        adjust_last_block(o, n, block_length);
1163                        for(i = 0; i < pmb_nr; i++)
1164                                moved_block_clear(&pmb[i]);
1165                        pmb_nr = 0;
1166                        block_length = 0;
1167                        flipped_block = 0;
1168                        last_symbol = l->s;
1169                        continue;
1170                }
1171
1172                if (o->color_moved == COLOR_MOVED_PLAIN) {
1173                        last_symbol = l->s;
1174                        l->flags |= DIFF_SYMBOL_MOVED_LINE;
1175                        continue;
1176                }
1177
1178                if (o->color_moved_ws_handling &
1179                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1180                        pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
1181                else
1182                        pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
1183
1184                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
1185
1186                if (pmb_nr == 0) {
1187                        /*
1188                         * The current line is the start of a new block.
1189                         * Setup the set of potential blocks.
1190                         */
1191                        for (; match; match = hashmap_get_next(hm, match)) {
1192                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
1193                                if (o->color_moved_ws_handling &
1194                                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
1195                                        if (compute_ws_delta(l, match->es,
1196                                                             &pmb[pmb_nr].wsd))
1197                                                pmb[pmb_nr++].match = match;
1198                                } else {
1199                                        pmb[pmb_nr].wsd = 0;
1200                                        pmb[pmb_nr++].match = match;
1201                                }
1202                        }
1203
1204                        if (adjust_last_block(o, n, block_length) &&
1205                            pmb_nr && last_symbol != l->s)
1206                                flipped_block = (flipped_block + 1) % 2;
1207                        else
1208                                flipped_block = 0;
1209
1210                        block_length = 0;
1211                }
1212
1213                if (pmb_nr) {
1214                        block_length++;
1215                        l->flags |= DIFF_SYMBOL_MOVED_LINE;
1216                        if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
1217                                l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
1218                }
1219                last_symbol = l->s;
1220        }
1221        adjust_last_block(o, n, block_length);
1222
1223        for(n = 0; n < pmb_nr; n++)
1224                moved_block_clear(&pmb[n]);
1225        free(pmb);
1226}
1227
1228#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
1229  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
1230static void dim_moved_lines(struct diff_options *o)
1231{
1232        int n;
1233        for (n = 0; n < o->emitted_symbols->nr; n++) {
1234                struct emitted_diff_symbol *prev = (n != 0) ?
1235                                &o->emitted_symbols->buf[n - 1] : NULL;
1236                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1237                struct emitted_diff_symbol *next =
1238                                (n < o->emitted_symbols->nr - 1) ?
1239                                &o->emitted_symbols->buf[n + 1] : NULL;
1240
1241                /* Not a plus or minus line? */
1242                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
1243                        continue;
1244
1245                /* Not a moved line? */
1246                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
1247                        continue;
1248
1249                /*
1250                 * If prev or next are not a plus or minus line,
1251                 * pretend they don't exist
1252                 */
1253                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1254                            prev->s != DIFF_SYMBOL_MINUS)
1255                        prev = NULL;
1256                if (next && next->s != DIFF_SYMBOL_PLUS &&
1257                            next->s != DIFF_SYMBOL_MINUS)
1258                        next = NULL;
1259
1260                /* Inside a block? */
1261                if ((prev &&
1262                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1263                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1264                    (next &&
1265                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1266                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1267                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1268                        continue;
1269                }
1270
1271                /* Check if we are at an interesting bound: */
1272                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1273                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1274                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1275                        continue;
1276                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1277                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1278                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1279                        continue;
1280
1281                /*
1282                 * The boundary to prev and next are not interesting,
1283                 * so this line is not interesting as a whole
1284                 */
1285                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1286        }
1287}
1288
1289static void emit_line_ws_markup(struct diff_options *o,
1290                                const char *set_sign, const char *set,
1291                                const char *reset,
1292                                int sign_index, const char *line, int len,
1293                                unsigned ws_rule, int blank_at_eof)
1294{
1295        const char *ws = NULL;
1296        int sign = o->output_indicators[sign_index];
1297
1298        if (o->ws_error_highlight & ws_rule) {
1299                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1300                if (!*ws)
1301                        ws = NULL;
1302        }
1303
1304        if (!ws && !set_sign)
1305                emit_line_0(o, set, NULL, 0, reset, sign, line, len);
1306        else if (!ws) {
1307                emit_line_0(o, set_sign, set, !!set_sign, reset, sign, line, len);
1308        } else if (blank_at_eof)
1309                /* Blank line at EOF - paint '+' as well */
1310                emit_line_0(o, ws, NULL, 0, reset, sign, line, len);
1311        else {
1312                /* Emit just the prefix, then the rest. */
1313                emit_line_0(o, set_sign ? set_sign : set, NULL, !!set_sign, reset,
1314                            sign, "", 0);
1315                ws_check_emit(line, len, ws_rule,
1316                              o->file, set, reset, ws);
1317        }
1318}
1319
1320static void emit_diff_symbol_from_struct(struct diff_options *o,
1321                                         struct emitted_diff_symbol *eds)
1322{
1323        static const char *nneof = " No newline at end of file\n";
1324        const char *context, *reset, *set, *set_sign, *meta, *fraginfo;
1325        struct strbuf sb = STRBUF_INIT;
1326
1327        enum diff_symbol s = eds->s;
1328        const char *line = eds->line;
1329        int len = eds->len;
1330        unsigned flags = eds->flags;
1331
1332        switch (s) {
1333        case DIFF_SYMBOL_NO_LF_EOF:
1334                context = diff_get_color_opt(o, DIFF_CONTEXT);
1335                reset = diff_get_color_opt(o, DIFF_RESET);
1336                putc('\n', o->file);
1337                emit_line_0(o, context, NULL, 0, reset, '\\',
1338                            nneof, strlen(nneof));
1339                break;
1340        case DIFF_SYMBOL_SUBMODULE_HEADER:
1341        case DIFF_SYMBOL_SUBMODULE_ERROR:
1342        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1343        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1344        case DIFF_SYMBOL_SUMMARY:
1345        case DIFF_SYMBOL_STATS_LINE:
1346        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1347        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1348                emit_line(o, "", "", line, len);
1349                break;
1350        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1351        case DIFF_SYMBOL_CONTEXT_MARKER:
1352                context = diff_get_color_opt(o, DIFF_CONTEXT);
1353                reset = diff_get_color_opt(o, DIFF_RESET);
1354                emit_line(o, context, reset, line, len);
1355                break;
1356        case DIFF_SYMBOL_SEPARATOR:
1357                fprintf(o->file, "%s%c",
1358                        diff_line_prefix(o),
1359                        o->line_termination);
1360                break;
1361        case DIFF_SYMBOL_CONTEXT:
1362                set = diff_get_color_opt(o, DIFF_CONTEXT);
1363                reset = diff_get_color_opt(o, DIFF_RESET);
1364                set_sign = NULL;
1365                if (o->flags.dual_color_diffed_diffs) {
1366                        char c = !len ? 0 : line[0];
1367
1368                        if (c == '+')
1369                                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1370                        else if (c == '@')
1371                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1372                        else if (c == '-')
1373                                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1374                }
1375                emit_line_ws_markup(o, set_sign, set, reset,
1376                                    OUTPUT_INDICATOR_CONTEXT, line, len,
1377                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1378                break;
1379        case DIFF_SYMBOL_PLUS:
1380                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1381                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1382                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1383                case DIFF_SYMBOL_MOVED_LINE |
1384                     DIFF_SYMBOL_MOVED_LINE_ALT |
1385                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1386                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1387                        break;
1388                case DIFF_SYMBOL_MOVED_LINE |
1389                     DIFF_SYMBOL_MOVED_LINE_ALT:
1390                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1391                        break;
1392                case DIFF_SYMBOL_MOVED_LINE |
1393                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1394                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1395                        break;
1396                case DIFF_SYMBOL_MOVED_LINE:
1397                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1398                        break;
1399                default:
1400                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1401                }
1402                reset = diff_get_color_opt(o, DIFF_RESET);
1403                if (!o->flags.dual_color_diffed_diffs)
1404                        set_sign = NULL;
1405                else {
1406                        char c = !len ? 0 : line[0];
1407
1408                        set_sign = set;
1409                        if (c == '-')
1410                                set = diff_get_color_opt(o, DIFF_FILE_OLD_BOLD);
1411                        else if (c == '@')
1412                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1413                        else if (c == '+')
1414                                set = diff_get_color_opt(o, DIFF_FILE_NEW_BOLD);
1415                        else
1416                                set = diff_get_color_opt(o, DIFF_CONTEXT_BOLD);
1417                        flags &= ~DIFF_SYMBOL_CONTENT_WS_MASK;
1418                }
1419                emit_line_ws_markup(o, set_sign, set, reset,
1420                                    OUTPUT_INDICATOR_NEW, line, len,
1421                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1422                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1423                break;
1424        case DIFF_SYMBOL_MINUS:
1425                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1426                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1427                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1428                case DIFF_SYMBOL_MOVED_LINE |
1429                     DIFF_SYMBOL_MOVED_LINE_ALT |
1430                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1431                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1432                        break;
1433                case DIFF_SYMBOL_MOVED_LINE |
1434                     DIFF_SYMBOL_MOVED_LINE_ALT:
1435                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1436                        break;
1437                case DIFF_SYMBOL_MOVED_LINE |
1438                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1439                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1440                        break;
1441                case DIFF_SYMBOL_MOVED_LINE:
1442                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1443                        break;
1444                default:
1445                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1446                }
1447                reset = diff_get_color_opt(o, DIFF_RESET);
1448                if (!o->flags.dual_color_diffed_diffs)
1449                        set_sign = NULL;
1450                else {
1451                        char c = !len ? 0 : line[0];
1452
1453                        set_sign = set;
1454                        if (c == '+')
1455                                set = diff_get_color_opt(o, DIFF_FILE_NEW_DIM);
1456                        else if (c == '@')
1457                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1458                        else if (c == '-')
1459                                set = diff_get_color_opt(o, DIFF_FILE_OLD_DIM);
1460                        else
1461                                set = diff_get_color_opt(o, DIFF_CONTEXT_DIM);
1462                }
1463                emit_line_ws_markup(o, set_sign, set, reset,
1464                                    OUTPUT_INDICATOR_OLD, line, len,
1465                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1466                break;
1467        case DIFF_SYMBOL_WORDS_PORCELAIN:
1468                context = diff_get_color_opt(o, DIFF_CONTEXT);
1469                reset = diff_get_color_opt(o, DIFF_RESET);
1470                emit_line(o, context, reset, line, len);
1471                fputs("~\n", o->file);
1472                break;
1473        case DIFF_SYMBOL_WORDS:
1474                context = diff_get_color_opt(o, DIFF_CONTEXT);
1475                reset = diff_get_color_opt(o, DIFF_RESET);
1476                /*
1477                 * Skip the prefix character, if any.  With
1478                 * diff_suppress_blank_empty, there may be
1479                 * none.
1480                 */
1481                if (line[0] != '\n') {
1482                        line++;
1483                        len--;
1484                }
1485                emit_line(o, context, reset, line, len);
1486                break;
1487        case DIFF_SYMBOL_FILEPAIR_PLUS:
1488                meta = diff_get_color_opt(o, DIFF_METAINFO);
1489                reset = diff_get_color_opt(o, DIFF_RESET);
1490                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1491                        line, reset,
1492                        strchr(line, ' ') ? "\t" : "");
1493                break;
1494        case DIFF_SYMBOL_FILEPAIR_MINUS:
1495                meta = diff_get_color_opt(o, DIFF_METAINFO);
1496                reset = diff_get_color_opt(o, DIFF_RESET);
1497                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1498                        line, reset,
1499                        strchr(line, ' ') ? "\t" : "");
1500                break;
1501        case DIFF_SYMBOL_BINARY_FILES:
1502        case DIFF_SYMBOL_HEADER:
1503                fprintf(o->file, "%s", line);
1504                break;
1505        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1506                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1507                break;
1508        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1509                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1510                break;
1511        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1512                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1513                break;
1514        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1515                fputs(diff_line_prefix(o), o->file);
1516                fputc('\n', o->file);
1517                break;
1518        case DIFF_SYMBOL_REWRITE_DIFF:
1519                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1520                reset = diff_get_color_opt(o, DIFF_RESET);
1521                emit_line(o, fraginfo, reset, line, len);
1522                break;
1523        case DIFF_SYMBOL_SUBMODULE_ADD:
1524                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1525                reset = diff_get_color_opt(o, DIFF_RESET);
1526                emit_line(o, set, reset, line, len);
1527                break;
1528        case DIFF_SYMBOL_SUBMODULE_DEL:
1529                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1530                reset = diff_get_color_opt(o, DIFF_RESET);
1531                emit_line(o, set, reset, line, len);
1532                break;
1533        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1534                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1535                        diff_line_prefix(o), line);
1536                break;
1537        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1538                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1539                        diff_line_prefix(o), line);
1540                break;
1541        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1542                emit_line(o, "", "", " 0 files changed\n",
1543                          strlen(" 0 files changed\n"));
1544                break;
1545        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1546                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1547                break;
1548        case DIFF_SYMBOL_WORD_DIFF:
1549                fprintf(o->file, "%.*s", len, line);
1550                break;
1551        case DIFF_SYMBOL_STAT_SEP:
1552                fputs(o->stat_sep, o->file);
1553                break;
1554        default:
1555                BUG("unknown diff symbol");
1556        }
1557        strbuf_release(&sb);
1558}
1559
1560static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1561                             const char *line, int len, unsigned flags)
1562{
1563        struct emitted_diff_symbol e = {line, len, flags, 0, 0, s};
1564
1565        if (o->emitted_symbols)
1566                append_emitted_diff_symbol(o, &e);
1567        else
1568                emit_diff_symbol_from_struct(o, &e);
1569}
1570
1571void diff_emit_submodule_del(struct diff_options *o, const char *line)
1572{
1573        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1574}
1575
1576void diff_emit_submodule_add(struct diff_options *o, const char *line)
1577{
1578        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1579}
1580
1581void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1582{
1583        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1584                         path, strlen(path), 0);
1585}
1586
1587void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1588{
1589        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1590                         path, strlen(path), 0);
1591}
1592
1593void diff_emit_submodule_header(struct diff_options *o, const char *header)
1594{
1595        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1596                         header, strlen(header), 0);
1597}
1598
1599void diff_emit_submodule_error(struct diff_options *o, const char *err)
1600{
1601        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1602}
1603
1604void diff_emit_submodule_pipethrough(struct diff_options *o,
1605                                     const char *line, int len)
1606{
1607        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1608}
1609
1610static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1611{
1612        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1613              ecbdata->blank_at_eof_in_preimage &&
1614              ecbdata->blank_at_eof_in_postimage &&
1615              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1616              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1617                return 0;
1618        return ws_blank_line(line, len, ecbdata->ws_rule);
1619}
1620
1621static void emit_add_line(struct emit_callback *ecbdata,
1622                          const char *line, int len)
1623{
1624        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1625        if (new_blank_line_at_eof(ecbdata, line, len))
1626                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1627
1628        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1629}
1630
1631static void emit_del_line(struct emit_callback *ecbdata,
1632                          const char *line, int len)
1633{
1634        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1635        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1636}
1637
1638static void emit_context_line(struct emit_callback *ecbdata,
1639                              const char *line, int len)
1640{
1641        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1642        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1643}
1644
1645static void emit_hunk_header(struct emit_callback *ecbdata,
1646                             const char *line, int len)
1647{
1648        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1649        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1650        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1651        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1652        const char *reverse = ecbdata->color_diff ? GIT_COLOR_REVERSE : "";
1653        static const char atat[2] = { '@', '@' };
1654        const char *cp, *ep;
1655        struct strbuf msgbuf = STRBUF_INIT;
1656        int org_len = len;
1657        int i = 1;
1658
1659        /*
1660         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1661         * it always is at least 10 bytes long.
1662         */
1663        if (len < 10 ||
1664            memcmp(line, atat, 2) ||
1665            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1666                emit_diff_symbol(ecbdata->opt,
1667                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1668                return;
1669        }
1670        ep += 2; /* skip over @@ */
1671
1672        /* The hunk header in fraginfo color */
1673        if (ecbdata->opt->flags.dual_color_diffed_diffs)
1674                strbuf_addstr(&msgbuf, reverse);
1675        strbuf_addstr(&msgbuf, frag);
1676        if (ecbdata->opt->flags.suppress_hunk_header_line_count)
1677                strbuf_add(&msgbuf, atat, sizeof(atat));
1678        else
1679                strbuf_add(&msgbuf, line, ep - line);
1680        strbuf_addstr(&msgbuf, reset);
1681
1682        /*
1683         * trailing "\r\n"
1684         */
1685        for ( ; i < 3; i++)
1686                if (line[len - i] == '\r' || line[len - i] == '\n')
1687                        len--;
1688
1689        /* blank before the func header */
1690        for (cp = ep; ep - line < len; ep++)
1691                if (*ep != ' ' && *ep != '\t')
1692                        break;
1693        if (ep != cp) {
1694                strbuf_addstr(&msgbuf, context);
1695                strbuf_add(&msgbuf, cp, ep - cp);
1696                strbuf_addstr(&msgbuf, reset);
1697        }
1698
1699        if (ep < line + len) {
1700                strbuf_addstr(&msgbuf, func);
1701                strbuf_add(&msgbuf, ep, line + len - ep);
1702                strbuf_addstr(&msgbuf, reset);
1703        }
1704
1705        strbuf_add(&msgbuf, line + len, org_len - len);
1706        strbuf_complete_line(&msgbuf);
1707        emit_diff_symbol(ecbdata->opt,
1708                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1709        strbuf_release(&msgbuf);
1710}
1711
1712static struct diff_tempfile *claim_diff_tempfile(void)
1713{
1714        int i;
1715        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1716                if (!diff_temp[i].name)
1717                        return diff_temp + i;
1718        BUG("diff is failing to clean up its tempfiles");
1719}
1720
1721static void remove_tempfile(void)
1722{
1723        int i;
1724        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1725                if (is_tempfile_active(diff_temp[i].tempfile))
1726                        delete_tempfile(&diff_temp[i].tempfile);
1727                diff_temp[i].name = NULL;
1728        }
1729}
1730
1731static void add_line_count(struct strbuf *out, int count)
1732{
1733        switch (count) {
1734        case 0:
1735                strbuf_addstr(out, "0,0");
1736                break;
1737        case 1:
1738                strbuf_addstr(out, "1");
1739                break;
1740        default:
1741                strbuf_addf(out, "1,%d", count);
1742                break;
1743        }
1744}
1745
1746static void emit_rewrite_lines(struct emit_callback *ecb,
1747                               int prefix, const char *data, int size)
1748{
1749        const char *endp = NULL;
1750
1751        while (0 < size) {
1752                int len;
1753
1754                endp = memchr(data, '\n', size);
1755                len = endp ? (endp - data + 1) : size;
1756                if (prefix != '+') {
1757                        ecb->lno_in_preimage++;
1758                        emit_del_line(ecb, data, len);
1759                } else {
1760                        ecb->lno_in_postimage++;
1761                        emit_add_line(ecb, data, len);
1762                }
1763                size -= len;
1764                data += len;
1765        }
1766        if (!endp)
1767                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1768}
1769
1770static void emit_rewrite_diff(const char *name_a,
1771                              const char *name_b,
1772                              struct diff_filespec *one,
1773                              struct diff_filespec *two,
1774                              struct userdiff_driver *textconv_one,
1775                              struct userdiff_driver *textconv_two,
1776                              struct diff_options *o)
1777{
1778        int lc_a, lc_b;
1779        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1780        const char *a_prefix, *b_prefix;
1781        char *data_one, *data_two;
1782        size_t size_one, size_two;
1783        struct emit_callback ecbdata;
1784        struct strbuf out = STRBUF_INIT;
1785
1786        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1787                a_prefix = o->b_prefix;
1788                b_prefix = o->a_prefix;
1789        } else {
1790                a_prefix = o->a_prefix;
1791                b_prefix = o->b_prefix;
1792        }
1793
1794        name_a += (*name_a == '/');
1795        name_b += (*name_b == '/');
1796
1797        strbuf_reset(&a_name);
1798        strbuf_reset(&b_name);
1799        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1800        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1801
1802        size_one = fill_textconv(o->repo, textconv_one, one, &data_one);
1803        size_two = fill_textconv(o->repo, textconv_two, two, &data_two);
1804
1805        memset(&ecbdata, 0, sizeof(ecbdata));
1806        ecbdata.color_diff = want_color(o->use_color);
1807        ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
1808        ecbdata.opt = o;
1809        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1810                mmfile_t mf1, mf2;
1811                mf1.ptr = (char *)data_one;
1812                mf2.ptr = (char *)data_two;
1813                mf1.size = size_one;
1814                mf2.size = size_two;
1815                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1816        }
1817        ecbdata.lno_in_preimage = 1;
1818        ecbdata.lno_in_postimage = 1;
1819
1820        lc_a = count_lines(data_one, size_one);
1821        lc_b = count_lines(data_two, size_two);
1822
1823        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1824                         a_name.buf, a_name.len, 0);
1825        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1826                         b_name.buf, b_name.len, 0);
1827
1828        strbuf_addstr(&out, "@@ -");
1829        if (!o->irreversible_delete)
1830                add_line_count(&out, lc_a);
1831        else
1832                strbuf_addstr(&out, "?,?");
1833        strbuf_addstr(&out, " +");
1834        add_line_count(&out, lc_b);
1835        strbuf_addstr(&out, " @@\n");
1836        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1837        strbuf_release(&out);
1838
1839        if (lc_a && !o->irreversible_delete)
1840                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1841        if (lc_b)
1842                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1843        if (textconv_one)
1844                free((char *)data_one);
1845        if (textconv_two)
1846                free((char *)data_two);
1847}
1848
1849struct diff_words_buffer {
1850        mmfile_t text;
1851        unsigned long alloc;
1852        struct diff_words_orig {
1853                const char *begin, *end;
1854        } *orig;
1855        int orig_nr, orig_alloc;
1856};
1857
1858static void diff_words_append(char *line, unsigned long len,
1859                struct diff_words_buffer *buffer)
1860{
1861        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1862        line++;
1863        len--;
1864        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1865        buffer->text.size += len;
1866        buffer->text.ptr[buffer->text.size] = '\0';
1867}
1868
1869struct diff_words_style_elem {
1870        const char *prefix;
1871        const char *suffix;
1872        const char *color; /* NULL; filled in by the setup code if
1873                            * color is enabled */
1874};
1875
1876struct diff_words_style {
1877        enum diff_words_type type;
1878        struct diff_words_style_elem new_word, old_word, ctx;
1879        const char *newline;
1880};
1881
1882static struct diff_words_style diff_words_styles[] = {
1883        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1884        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1885        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1886};
1887
1888struct diff_words_data {
1889        struct diff_words_buffer minus, plus;
1890        const char *current_plus;
1891        int last_minus;
1892        struct diff_options *opt;
1893        regex_t *word_regex;
1894        enum diff_words_type type;
1895        struct diff_words_style *style;
1896};
1897
1898static int fn_out_diff_words_write_helper(struct diff_options *o,
1899                                          struct diff_words_style_elem *st_el,
1900                                          const char *newline,
1901                                          size_t count, const char *buf)
1902{
1903        int print = 0;
1904        struct strbuf sb = STRBUF_INIT;
1905
1906        while (count) {
1907                char *p = memchr(buf, '\n', count);
1908                if (print)
1909                        strbuf_addstr(&sb, diff_line_prefix(o));
1910
1911                if (p != buf) {
1912                        const char *reset = st_el->color && *st_el->color ?
1913                                            GIT_COLOR_RESET : NULL;
1914                        if (st_el->color && *st_el->color)
1915                                strbuf_addstr(&sb, st_el->color);
1916                        strbuf_addstr(&sb, st_el->prefix);
1917                        strbuf_add(&sb, buf, p ? p - buf : count);
1918                        strbuf_addstr(&sb, st_el->suffix);
1919                        if (reset)
1920                                strbuf_addstr(&sb, reset);
1921                }
1922                if (!p)
1923                        goto out;
1924
1925                strbuf_addstr(&sb, newline);
1926                count -= p + 1 - buf;
1927                buf = p + 1;
1928                print = 1;
1929                if (count) {
1930                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1931                                         sb.buf, sb.len, 0);
1932                        strbuf_reset(&sb);
1933                }
1934        }
1935
1936out:
1937        if (sb.len)
1938                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1939                                 sb.buf, sb.len, 0);
1940        strbuf_release(&sb);
1941        return 0;
1942}
1943
1944/*
1945 * '--color-words' algorithm can be described as:
1946 *
1947 *   1. collect the minus/plus lines of a diff hunk, divided into
1948 *      minus-lines and plus-lines;
1949 *
1950 *   2. break both minus-lines and plus-lines into words and
1951 *      place them into two mmfile_t with one word for each line;
1952 *
1953 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1954 *
1955 * And for the common parts of the both file, we output the plus side text.
1956 * diff_words->current_plus is used to trace the current position of the plus file
1957 * which printed. diff_words->last_minus is used to trace the last minus word
1958 * printed.
1959 *
1960 * For '--graph' to work with '--color-words', we need to output the graph prefix
1961 * on each line of color words output. Generally, there are two conditions on
1962 * which we should output the prefix.
1963 *
1964 *   1. diff_words->last_minus == 0 &&
1965 *      diff_words->current_plus == diff_words->plus.text.ptr
1966 *
1967 *      that is: the plus text must start as a new line, and if there is no minus
1968 *      word printed, a graph prefix must be printed.
1969 *
1970 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1971 *      *(diff_words->current_plus - 1) == '\n'
1972 *
1973 *      that is: a graph prefix must be printed following a '\n'
1974 */
1975static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1976{
1977        if ((diff_words->last_minus == 0 &&
1978                diff_words->current_plus == diff_words->plus.text.ptr) ||
1979                (diff_words->current_plus > diff_words->plus.text.ptr &&
1980                *(diff_words->current_plus - 1) == '\n')) {
1981                return 1;
1982        } else {
1983                return 0;
1984        }
1985}
1986
1987static void fn_out_diff_words_aux(void *priv,
1988                                  long minus_first, long minus_len,
1989                                  long plus_first, long plus_len,
1990                                  const char *func, long funclen)
1991{
1992        struct diff_words_data *diff_words = priv;
1993        struct diff_words_style *style = diff_words->style;
1994        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1995        struct diff_options *opt = diff_words->opt;
1996        const char *line_prefix;
1997
1998        assert(opt);
1999        line_prefix = diff_line_prefix(opt);
2000
2001        /* POSIX requires that first be decremented by one if len == 0... */
2002        if (minus_len) {
2003                minus_begin = diff_words->minus.orig[minus_first].begin;
2004                minus_end =
2005                        diff_words->minus.orig[minus_first + minus_len - 1].end;
2006        } else
2007                minus_begin = minus_end =
2008                        diff_words->minus.orig[minus_first].end;
2009
2010        if (plus_len) {
2011                plus_begin = diff_words->plus.orig[plus_first].begin;
2012                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
2013        } else
2014                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
2015
2016        if (color_words_output_graph_prefix(diff_words)) {
2017                fputs(line_prefix, diff_words->opt->file);
2018        }
2019        if (diff_words->current_plus != plus_begin) {
2020                fn_out_diff_words_write_helper(diff_words->opt,
2021                                &style->ctx, style->newline,
2022                                plus_begin - diff_words->current_plus,
2023                                diff_words->current_plus);
2024        }
2025        if (minus_begin != minus_end) {
2026                fn_out_diff_words_write_helper(diff_words->opt,
2027                                &style->old_word, style->newline,
2028                                minus_end - minus_begin, minus_begin);
2029        }
2030        if (plus_begin != plus_end) {
2031                fn_out_diff_words_write_helper(diff_words->opt,
2032                                &style->new_word, style->newline,
2033                                plus_end - plus_begin, plus_begin);
2034        }
2035
2036        diff_words->current_plus = plus_end;
2037        diff_words->last_minus = minus_first;
2038}
2039
2040/* This function starts looking at *begin, and returns 0 iff a word was found. */
2041static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
2042                int *begin, int *end)
2043{
2044        if (word_regex && *begin < buffer->size) {
2045                regmatch_t match[1];
2046                if (!regexec_buf(word_regex, buffer->ptr + *begin,
2047                                 buffer->size - *begin, 1, match, 0)) {
2048                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
2049                                        '\n', match[0].rm_eo - match[0].rm_so);
2050                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
2051                        *begin += match[0].rm_so;
2052                        return *begin >= *end;
2053                }
2054                return -1;
2055        }
2056
2057        /* find the next word */
2058        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
2059                (*begin)++;
2060        if (*begin >= buffer->size)
2061                return -1;
2062
2063        /* find the end of the word */
2064        *end = *begin + 1;
2065        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
2066                (*end)++;
2067
2068        return 0;
2069}
2070
2071/*
2072 * This function splits the words in buffer->text, stores the list with
2073 * newline separator into out, and saves the offsets of the original words
2074 * in buffer->orig.
2075 */
2076static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
2077                regex_t *word_regex)
2078{
2079        int i, j;
2080        long alloc = 0;
2081
2082        out->size = 0;
2083        out->ptr = NULL;
2084
2085        /* fake an empty "0th" word */
2086        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
2087        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
2088        buffer->orig_nr = 1;
2089
2090        for (i = 0; i < buffer->text.size; i++) {
2091                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
2092                        return;
2093
2094                /* store original boundaries */
2095                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
2096                                buffer->orig_alloc);
2097                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
2098                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
2099                buffer->orig_nr++;
2100
2101                /* store one word */
2102                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
2103                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
2104                out->ptr[out->size + j - i] = '\n';
2105                out->size += j - i + 1;
2106
2107                i = j - 1;
2108        }
2109}
2110
2111/* this executes the word diff on the accumulated buffers */
2112static void diff_words_show(struct diff_words_data *diff_words)
2113{
2114        xpparam_t xpp;
2115        xdemitconf_t xecfg;
2116        mmfile_t minus, plus;
2117        struct diff_words_style *style = diff_words->style;
2118
2119        struct diff_options *opt = diff_words->opt;
2120        const char *line_prefix;
2121
2122        assert(opt);
2123        line_prefix = diff_line_prefix(opt);
2124
2125        /* special case: only removal */
2126        if (!diff_words->plus.text.size) {
2127                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2128                                 line_prefix, strlen(line_prefix), 0);
2129                fn_out_diff_words_write_helper(diff_words->opt,
2130                        &style->old_word, style->newline,
2131                        diff_words->minus.text.size,
2132                        diff_words->minus.text.ptr);
2133                diff_words->minus.text.size = 0;
2134                return;
2135        }
2136
2137        diff_words->current_plus = diff_words->plus.text.ptr;
2138        diff_words->last_minus = 0;
2139
2140        memset(&xpp, 0, sizeof(xpp));
2141        memset(&xecfg, 0, sizeof(xecfg));
2142        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
2143        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
2144        xpp.flags = 0;
2145        /* as only the hunk header will be parsed, we need a 0-context */
2146        xecfg.ctxlen = 0;
2147        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, NULL,
2148                          diff_words, &xpp, &xecfg))
2149                die("unable to generate word diff");
2150        free(minus.ptr);
2151        free(plus.ptr);
2152        if (diff_words->current_plus != diff_words->plus.text.ptr +
2153                        diff_words->plus.text.size) {
2154                if (color_words_output_graph_prefix(diff_words))
2155                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2156                                         line_prefix, strlen(line_prefix), 0);
2157                fn_out_diff_words_write_helper(diff_words->opt,
2158                        &style->ctx, style->newline,
2159                        diff_words->plus.text.ptr + diff_words->plus.text.size
2160                        - diff_words->current_plus, diff_words->current_plus);
2161        }
2162        diff_words->minus.text.size = diff_words->plus.text.size = 0;
2163}
2164
2165/* In "color-words" mode, show word-diff of words accumulated in the buffer */
2166static void diff_words_flush(struct emit_callback *ecbdata)
2167{
2168        struct diff_options *wo = ecbdata->diff_words->opt;
2169
2170        if (ecbdata->diff_words->minus.text.size ||
2171            ecbdata->diff_words->plus.text.size)
2172                diff_words_show(ecbdata->diff_words);
2173
2174        if (wo->emitted_symbols) {
2175                struct diff_options *o = ecbdata->opt;
2176                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2177                int i;
2178
2179                /*
2180                 * NEEDSWORK:
2181                 * Instead of appending each, concat all words to a line?
2182                 */
2183                for (i = 0; i < wol->nr; i++)
2184                        append_emitted_diff_symbol(o, &wol->buf[i]);
2185
2186                for (i = 0; i < wol->nr; i++)
2187                        free((void *)wol->buf[i].line);
2188
2189                wol->nr = 0;
2190        }
2191}
2192
2193static void diff_filespec_load_driver(struct diff_filespec *one,
2194                                      struct index_state *istate)
2195{
2196        /* Use already-loaded driver */
2197        if (one->driver)
2198                return;
2199
2200        if (S_ISREG(one->mode))
2201                one->driver = userdiff_find_by_path(istate, one->path);
2202
2203        /* Fallback to default settings */
2204        if (!one->driver)
2205                one->driver = userdiff_find_by_name("default");
2206}
2207
2208static const char *userdiff_word_regex(struct diff_filespec *one,
2209                                       struct index_state *istate)
2210{
2211        diff_filespec_load_driver(one, istate);
2212        return one->driver->word_regex;
2213}
2214
2215static void init_diff_words_data(struct emit_callback *ecbdata,
2216                                 struct diff_options *orig_opts,
2217                                 struct diff_filespec *one,
2218                                 struct diff_filespec *two)
2219{
2220        int i;
2221        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2222        memcpy(o, orig_opts, sizeof(struct diff_options));
2223
2224        ecbdata->diff_words =
2225                xcalloc(1, sizeof(struct diff_words_data));
2226        ecbdata->diff_words->type = o->word_diff;
2227        ecbdata->diff_words->opt = o;
2228
2229        if (orig_opts->emitted_symbols)
2230                o->emitted_symbols =
2231                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2232
2233        if (!o->word_regex)
2234                o->word_regex = userdiff_word_regex(one, o->repo->index);
2235        if (!o->word_regex)
2236                o->word_regex = userdiff_word_regex(two, o->repo->index);
2237        if (!o->word_regex)
2238                o->word_regex = diff_word_regex_cfg;
2239        if (o->word_regex) {
2240                ecbdata->diff_words->word_regex = (regex_t *)
2241                        xmalloc(sizeof(regex_t));
2242                if (regcomp(ecbdata->diff_words->word_regex,
2243                            o->word_regex,
2244                            REG_EXTENDED | REG_NEWLINE))
2245                        die("invalid regular expression: %s",
2246                            o->word_regex);
2247        }
2248        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2249                if (o->word_diff == diff_words_styles[i].type) {
2250                        ecbdata->diff_words->style =
2251                                &diff_words_styles[i];
2252                        break;
2253                }
2254        }
2255        if (want_color(o->use_color)) {
2256                struct diff_words_style *st = ecbdata->diff_words->style;
2257                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2258                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2259                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2260        }
2261}
2262
2263static void free_diff_words_data(struct emit_callback *ecbdata)
2264{
2265        if (ecbdata->diff_words) {
2266                diff_words_flush(ecbdata);
2267                free (ecbdata->diff_words->opt->emitted_symbols);
2268                free (ecbdata->diff_words->opt);
2269                free (ecbdata->diff_words->minus.text.ptr);
2270                free (ecbdata->diff_words->minus.orig);
2271                free (ecbdata->diff_words->plus.text.ptr);
2272                free (ecbdata->diff_words->plus.orig);
2273                if (ecbdata->diff_words->word_regex) {
2274                        regfree(ecbdata->diff_words->word_regex);
2275                        free(ecbdata->diff_words->word_regex);
2276                }
2277                FREE_AND_NULL(ecbdata->diff_words);
2278        }
2279}
2280
2281const char *diff_get_color(int diff_use_color, enum color_diff ix)
2282{
2283        if (want_color(diff_use_color))
2284                return diff_colors[ix];
2285        return "";
2286}
2287
2288const char *diff_line_prefix(struct diff_options *opt)
2289{
2290        struct strbuf *msgbuf;
2291        if (!opt->output_prefix)
2292                return "";
2293
2294        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2295        return msgbuf->buf;
2296}
2297
2298static unsigned long sane_truncate_line(char *line, unsigned long len)
2299{
2300        const char *cp;
2301        unsigned long allot;
2302        size_t l = len;
2303
2304        cp = line;
2305        allot = l;
2306        while (0 < l) {
2307                (void) utf8_width(&cp, &l);
2308                if (!cp)
2309                        break; /* truncated in the middle? */
2310        }
2311        return allot - l;
2312}
2313
2314static void find_lno(const char *line, struct emit_callback *ecbdata)
2315{
2316        const char *p;
2317        ecbdata->lno_in_preimage = 0;
2318        ecbdata->lno_in_postimage = 0;
2319        p = strchr(line, '-');
2320        if (!p)
2321                return; /* cannot happen */
2322        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2323        p = strchr(p, '+');
2324        if (!p)
2325                return; /* cannot happen */
2326        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2327}
2328
2329static void fn_out_consume(void *priv, char *line, unsigned long len)
2330{
2331        struct emit_callback *ecbdata = priv;
2332        struct diff_options *o = ecbdata->opt;
2333
2334        o->found_changes = 1;
2335
2336        if (ecbdata->header) {
2337                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2338                                 ecbdata->header->buf, ecbdata->header->len, 0);
2339                strbuf_reset(ecbdata->header);
2340                ecbdata->header = NULL;
2341        }
2342
2343        if (ecbdata->label_path[0]) {
2344                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2345                                 ecbdata->label_path[0],
2346                                 strlen(ecbdata->label_path[0]), 0);
2347                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2348                                 ecbdata->label_path[1],
2349                                 strlen(ecbdata->label_path[1]), 0);
2350                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2351        }
2352
2353        if (diff_suppress_blank_empty
2354            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2355                line[0] = '\n';
2356                len = 1;
2357        }
2358
2359        if (line[0] == '@') {
2360                if (ecbdata->diff_words)
2361                        diff_words_flush(ecbdata);
2362                len = sane_truncate_line(line, len);
2363                find_lno(line, ecbdata);
2364                emit_hunk_header(ecbdata, line, len);
2365                return;
2366        }
2367
2368        if (ecbdata->diff_words) {
2369                enum diff_symbol s =
2370                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2371                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2372                if (line[0] == '-') {
2373                        diff_words_append(line, len,
2374                                          &ecbdata->diff_words->minus);
2375                        return;
2376                } else if (line[0] == '+') {
2377                        diff_words_append(line, len,
2378                                          &ecbdata->diff_words->plus);
2379                        return;
2380                } else if (starts_with(line, "\\ ")) {
2381                        /*
2382                         * Eat the "no newline at eof" marker as if we
2383                         * saw a "+" or "-" line with nothing on it,
2384                         * and return without diff_words_flush() to
2385                         * defer processing. If this is the end of
2386                         * preimage, more "+" lines may come after it.
2387                         */
2388                        return;
2389                }
2390                diff_words_flush(ecbdata);
2391                emit_diff_symbol(o, s, line, len, 0);
2392                return;
2393        }
2394
2395        switch (line[0]) {
2396        case '+':
2397                ecbdata->lno_in_postimage++;
2398                emit_add_line(ecbdata, line + 1, len - 1);
2399                break;
2400        case '-':
2401                ecbdata->lno_in_preimage++;
2402                emit_del_line(ecbdata, line + 1, len - 1);
2403                break;
2404        case ' ':
2405                ecbdata->lno_in_postimage++;
2406                ecbdata->lno_in_preimage++;
2407                emit_context_line(ecbdata, line + 1, len - 1);
2408                break;
2409        default:
2410                /* incomplete line at the end */
2411                ecbdata->lno_in_preimage++;
2412                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2413                                 line, len, 0);
2414                break;
2415        }
2416}
2417
2418static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2419{
2420        const char *old_name = a;
2421        const char *new_name = b;
2422        int pfx_length, sfx_length;
2423        int pfx_adjust_for_slash;
2424        int len_a = strlen(a);
2425        int len_b = strlen(b);
2426        int a_midlen, b_midlen;
2427        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2428        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2429
2430        if (qlen_a || qlen_b) {
2431                quote_c_style(a, name, NULL, 0);
2432                strbuf_addstr(name, " => ");
2433                quote_c_style(b, name, NULL, 0);
2434                return;
2435        }
2436
2437        /* Find common prefix */
2438        pfx_length = 0;
2439        while (*old_name && *new_name && *old_name == *new_name) {
2440                if (*old_name == '/')
2441                        pfx_length = old_name - a + 1;
2442                old_name++;
2443                new_name++;
2444        }
2445
2446        /* Find common suffix */
2447        old_name = a + len_a;
2448        new_name = b + len_b;
2449        sfx_length = 0;
2450        /*
2451         * If there is a common prefix, it must end in a slash.  In
2452         * that case we let this loop run 1 into the prefix to see the
2453         * same slash.
2454         *
2455         * If there is no common prefix, we cannot do this as it would
2456         * underrun the input strings.
2457         */
2458        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2459        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2460               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2461               *old_name == *new_name) {
2462                if (*old_name == '/')
2463                        sfx_length = len_a - (old_name - a);
2464                old_name--;
2465                new_name--;
2466        }
2467
2468        /*
2469         * pfx{mid-a => mid-b}sfx
2470         * {pfx-a => pfx-b}sfx
2471         * pfx{sfx-a => sfx-b}
2472         * name-a => name-b
2473         */
2474        a_midlen = len_a - pfx_length - sfx_length;
2475        b_midlen = len_b - pfx_length - sfx_length;
2476        if (a_midlen < 0)
2477                a_midlen = 0;
2478        if (b_midlen < 0)
2479                b_midlen = 0;
2480
2481        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2482        if (pfx_length + sfx_length) {
2483                strbuf_add(name, a, pfx_length);
2484                strbuf_addch(name, '{');
2485        }
2486        strbuf_add(name, a + pfx_length, a_midlen);
2487        strbuf_addstr(name, " => ");
2488        strbuf_add(name, b + pfx_length, b_midlen);
2489        if (pfx_length + sfx_length) {
2490                strbuf_addch(name, '}');
2491                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2492        }
2493}
2494
2495struct diffstat_t {
2496        int nr;
2497        int alloc;
2498        struct diffstat_file {
2499                char *from_name;
2500                char *name;
2501                char *print_name;
2502                const char *comments;
2503                unsigned is_unmerged:1;
2504                unsigned is_binary:1;
2505                unsigned is_renamed:1;
2506                unsigned is_interesting:1;
2507                uintmax_t added, deleted;
2508        } **files;
2509};
2510
2511static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2512                                          const char *name_a,
2513                                          const char *name_b)
2514{
2515        struct diffstat_file *x;
2516        x = xcalloc(1, sizeof(*x));
2517        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2518        diffstat->files[diffstat->nr++] = x;
2519        if (name_b) {
2520                x->from_name = xstrdup(name_a);
2521                x->name = xstrdup(name_b);
2522                x->is_renamed = 1;
2523        }
2524        else {
2525                x->from_name = NULL;
2526                x->name = xstrdup(name_a);
2527        }
2528        return x;
2529}
2530
2531static void diffstat_consume(void *priv, char *line, unsigned long len)
2532{
2533        struct diffstat_t *diffstat = priv;
2534        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2535
2536        if (line[0] == '+')
2537                x->added++;
2538        else if (line[0] == '-')
2539                x->deleted++;
2540}
2541
2542const char mime_boundary_leader[] = "------------";
2543
2544static int scale_linear(int it, int width, int max_change)
2545{
2546        if (!it)
2547                return 0;
2548        /*
2549         * make sure that at least one '-' or '+' is printed if
2550         * there is any change to this path. The easiest way is to
2551         * scale linearly as if the alloted width is one column shorter
2552         * than it is, and then add 1 to the result.
2553         */
2554        return 1 + (it * (width - 1) / max_change);
2555}
2556
2557static void show_graph(struct strbuf *out, char ch, int cnt,
2558                       const char *set, const char *reset)
2559{
2560        if (cnt <= 0)
2561                return;
2562        strbuf_addstr(out, set);
2563        strbuf_addchars(out, ch, cnt);
2564        strbuf_addstr(out, reset);
2565}
2566
2567static void fill_print_name(struct diffstat_file *file)
2568{
2569        struct strbuf pname = STRBUF_INIT;
2570
2571        if (file->print_name)
2572                return;
2573
2574        if (file->is_renamed)
2575                pprint_rename(&pname, file->from_name, file->name);
2576        else
2577                quote_c_style(file->name, &pname, NULL, 0);
2578
2579        if (file->comments)
2580                strbuf_addf(&pname, " (%s)", file->comments);
2581
2582        file->print_name = strbuf_detach(&pname, NULL);
2583}
2584
2585static void print_stat_summary_inserts_deletes(struct diff_options *options,
2586                int files, int insertions, int deletions)
2587{
2588        struct strbuf sb = STRBUF_INIT;
2589
2590        if (!files) {
2591                assert(insertions == 0 && deletions == 0);
2592                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2593                                 NULL, 0, 0);
2594                return;
2595        }
2596
2597        strbuf_addf(&sb,
2598                    (files == 1) ? " %d file changed" : " %d files changed",
2599                    files);
2600
2601        /*
2602         * For binary diff, the caller may want to print "x files
2603         * changed" with insertions == 0 && deletions == 0.
2604         *
2605         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2606         * is probably less confusing (i.e skip over "2 files changed
2607         * but nothing about added/removed lines? Is this a bug in Git?").
2608         */
2609        if (insertions || deletions == 0) {
2610                strbuf_addf(&sb,
2611                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2612                            insertions);
2613        }
2614
2615        if (deletions || insertions == 0) {
2616                strbuf_addf(&sb,
2617                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2618                            deletions);
2619        }
2620        strbuf_addch(&sb, '\n');
2621        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2622                         sb.buf, sb.len, 0);
2623        strbuf_release(&sb);
2624}
2625
2626void print_stat_summary(FILE *fp, int files,
2627                        int insertions, int deletions)
2628{
2629        struct diff_options o;
2630        memset(&o, 0, sizeof(o));
2631        o.file = fp;
2632
2633        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2634}
2635
2636static void show_stats(struct diffstat_t *data, struct diff_options *options)
2637{
2638        int i, len, add, del, adds = 0, dels = 0;
2639        uintmax_t max_change = 0, max_len = 0;
2640        int total_files = data->nr, count;
2641        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2642        const char *reset, *add_c, *del_c;
2643        int extra_shown = 0;
2644        const char *line_prefix = diff_line_prefix(options);
2645        struct strbuf out = STRBUF_INIT;
2646
2647        if (data->nr == 0)
2648                return;
2649
2650        count = options->stat_count ? options->stat_count : data->nr;
2651
2652        reset = diff_get_color_opt(options, DIFF_RESET);
2653        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2654        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2655
2656        /*
2657         * Find the longest filename and max number of changes
2658         */
2659        for (i = 0; (i < count) && (i < data->nr); i++) {
2660                struct diffstat_file *file = data->files[i];
2661                uintmax_t change = file->added + file->deleted;
2662
2663                if (!file->is_interesting && (change == 0)) {
2664                        count++; /* not shown == room for one more */
2665                        continue;
2666                }
2667                fill_print_name(file);
2668                len = strlen(file->print_name);
2669                if (max_len < len)
2670                        max_len = len;
2671
2672                if (file->is_unmerged) {
2673                        /* "Unmerged" is 8 characters */
2674                        bin_width = bin_width < 8 ? 8 : bin_width;
2675                        continue;
2676                }
2677                if (file->is_binary) {
2678                        /* "Bin XXX -> YYY bytes" */
2679                        int w = 14 + decimal_width(file->added)
2680                                + decimal_width(file->deleted);
2681                        bin_width = bin_width < w ? w : bin_width;
2682                        /* Display change counts aligned with "Bin" */
2683                        number_width = 3;
2684                        continue;
2685                }
2686
2687                if (max_change < change)
2688                        max_change = change;
2689        }
2690        count = i; /* where we can stop scanning in data->files[] */
2691
2692        /*
2693         * We have width = stat_width or term_columns() columns total.
2694         * We want a maximum of min(max_len, stat_name_width) for the name part.
2695         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2696         * We also need 1 for " " and 4 + decimal_width(max_change)
2697         * for " | NNNN " and one the empty column at the end, altogether
2698         * 6 + decimal_width(max_change).
2699         *
2700         * If there's not enough space, we will use the smaller of
2701         * stat_name_width (if set) and 5/8*width for the filename,
2702         * and the rest for constant elements + graph part, but no more
2703         * than stat_graph_width for the graph part.
2704         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2705         * for the standard terminal size).
2706         *
2707         * In other words: stat_width limits the maximum width, and
2708         * stat_name_width fixes the maximum width of the filename,
2709         * and is also used to divide available columns if there
2710         * aren't enough.
2711         *
2712         * Binary files are displayed with "Bin XXX -> YYY bytes"
2713         * instead of the change count and graph. This part is treated
2714         * similarly to the graph part, except that it is not
2715         * "scaled". If total width is too small to accommodate the
2716         * guaranteed minimum width of the filename part and the
2717         * separators and this message, this message will "overflow"
2718         * making the line longer than the maximum width.
2719         */
2720
2721        if (options->stat_width == -1)
2722                width = term_columns() - strlen(line_prefix);
2723        else
2724                width = options->stat_width ? options->stat_width : 80;
2725        number_width = decimal_width(max_change) > number_width ?
2726                decimal_width(max_change) : number_width;
2727
2728        if (options->stat_graph_width == -1)
2729                options->stat_graph_width = diff_stat_graph_width;
2730
2731        /*
2732         * Guarantee 3/8*16==6 for the graph part
2733         * and 5/8*16==10 for the filename part
2734         */
2735        if (width < 16 + 6 + number_width)
2736                width = 16 + 6 + number_width;
2737
2738        /*
2739         * First assign sizes that are wanted, ignoring available width.
2740         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2741         * starting from "XXX" should fit in graph_width.
2742         */
2743        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2744        if (options->stat_graph_width &&
2745            options->stat_graph_width < graph_width)
2746                graph_width = options->stat_graph_width;
2747
2748        name_width = (options->stat_name_width > 0 &&
2749                      options->stat_name_width < max_len) ?
2750                options->stat_name_width : max_len;
2751
2752        /*
2753         * Adjust adjustable widths not to exceed maximum width
2754         */
2755        if (name_width + number_width + 6 + graph_width > width) {
2756                if (graph_width > width * 3/8 - number_width - 6) {
2757                        graph_width = width * 3/8 - number_width - 6;
2758                        if (graph_width < 6)
2759                                graph_width = 6;
2760                }
2761
2762                if (options->stat_graph_width &&
2763                    graph_width > options->stat_graph_width)
2764                        graph_width = options->stat_graph_width;
2765                if (name_width > width - number_width - 6 - graph_width)
2766                        name_width = width - number_width - 6 - graph_width;
2767                else
2768                        graph_width = width - number_width - 6 - name_width;
2769        }
2770
2771        /*
2772         * From here name_width is the width of the name area,
2773         * and graph_width is the width of the graph area.
2774         * max_change is used to scale graph properly.
2775         */
2776        for (i = 0; i < count; i++) {
2777                const char *prefix = "";
2778                struct diffstat_file *file = data->files[i];
2779                char *name = file->print_name;
2780                uintmax_t added = file->added;
2781                uintmax_t deleted = file->deleted;
2782                int name_len;
2783
2784                if (!file->is_interesting && (added + deleted == 0))
2785                        continue;
2786
2787                /*
2788                 * "scale" the filename
2789                 */
2790                len = name_width;
2791                name_len = strlen(name);
2792                if (name_width < name_len) {
2793                        char *slash;
2794                        prefix = "...";
2795                        len -= 3;
2796                        name += name_len - len;
2797                        slash = strchr(name, '/');
2798                        if (slash)
2799                                name = slash;
2800                }
2801
2802                if (file->is_binary) {
2803                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2804                        strbuf_addf(&out, " %*s", number_width, "Bin");
2805                        if (!added && !deleted) {
2806                                strbuf_addch(&out, '\n');
2807                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2808                                                 out.buf, out.len, 0);
2809                                strbuf_reset(&out);
2810                                continue;
2811                        }
2812                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2813                                del_c, deleted, reset);
2814                        strbuf_addstr(&out, " -> ");
2815                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2816                                add_c, added, reset);
2817                        strbuf_addstr(&out, " bytes\n");
2818                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2819                                         out.buf, out.len, 0);
2820                        strbuf_reset(&out);
2821                        continue;
2822                }
2823                else if (file->is_unmerged) {
2824                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2825                        strbuf_addstr(&out, " Unmerged\n");
2826                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2827                                         out.buf, out.len, 0);
2828                        strbuf_reset(&out);
2829                        continue;
2830                }
2831
2832                /*
2833                 * scale the add/delete
2834                 */
2835                add = added;
2836                del = deleted;
2837
2838                if (graph_width <= max_change) {
2839                        int total = scale_linear(add + del, graph_width, max_change);
2840                        if (total < 2 && add && del)
2841                                /* width >= 2 due to the sanity check */
2842                                total = 2;
2843                        if (add < del) {
2844                                add = scale_linear(add, graph_width, max_change);
2845                                del = total - add;
2846                        } else {
2847                                del = scale_linear(del, graph_width, max_change);
2848                                add = total - del;
2849                        }
2850                }
2851                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2852                strbuf_addf(&out, " %*"PRIuMAX"%s",
2853                        number_width, added + deleted,
2854                        added + deleted ? " " : "");
2855                show_graph(&out, '+', add, add_c, reset);
2856                show_graph(&out, '-', del, del_c, reset);
2857                strbuf_addch(&out, '\n');
2858                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2859                                 out.buf, out.len, 0);
2860                strbuf_reset(&out);
2861        }
2862
2863        for (i = 0; i < data->nr; i++) {
2864                struct diffstat_file *file = data->files[i];
2865                uintmax_t added = file->added;
2866                uintmax_t deleted = file->deleted;
2867
2868                if (file->is_unmerged ||
2869                    (!file->is_interesting && (added + deleted == 0))) {
2870                        total_files--;
2871                        continue;
2872                }
2873
2874                if (!file->is_binary) {
2875                        adds += added;
2876                        dels += deleted;
2877                }
2878                if (i < count)
2879                        continue;
2880                if (!extra_shown)
2881                        emit_diff_symbol(options,
2882                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2883                                         NULL, 0, 0);
2884                extra_shown = 1;
2885        }
2886
2887        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2888        strbuf_release(&out);
2889}
2890
2891static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2892{
2893        int i, adds = 0, dels = 0, total_files = data->nr;
2894
2895        if (data->nr == 0)
2896                return;
2897
2898        for (i = 0; i < data->nr; i++) {
2899                int added = data->files[i]->added;
2900                int deleted = data->files[i]->deleted;
2901
2902                if (data->files[i]->is_unmerged ||
2903                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2904                        total_files--;
2905                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2906                        adds += added;
2907                        dels += deleted;
2908                }
2909        }
2910        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2911}
2912
2913static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2914{
2915        int i;
2916
2917        if (data->nr == 0)
2918                return;
2919
2920        for (i = 0; i < data->nr; i++) {
2921                struct diffstat_file *file = data->files[i];
2922
2923                fprintf(options->file, "%s", diff_line_prefix(options));
2924
2925                if (file->is_binary)
2926                        fprintf(options->file, "-\t-\t");
2927                else
2928                        fprintf(options->file,
2929                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2930                                file->added, file->deleted);
2931                if (options->line_termination) {
2932                        fill_print_name(file);
2933                        if (!file->is_renamed)
2934                                write_name_quoted(file->name, options->file,
2935                                                  options->line_termination);
2936                        else {
2937                                fputs(file->print_name, options->file);
2938                                putc(options->line_termination, options->file);
2939                        }
2940                } else {
2941                        if (file->is_renamed) {
2942                                putc('\0', options->file);
2943                                write_name_quoted(file->from_name, options->file, '\0');
2944                        }
2945                        write_name_quoted(file->name, options->file, '\0');
2946                }
2947        }
2948}
2949
2950struct dirstat_file {
2951        const char *name;
2952        unsigned long changed;
2953};
2954
2955struct dirstat_dir {
2956        struct dirstat_file *files;
2957        int alloc, nr, permille, cumulative;
2958};
2959
2960static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2961                unsigned long changed, const char *base, int baselen)
2962{
2963        unsigned long sum_changes = 0;
2964        unsigned int sources = 0;
2965        const char *line_prefix = diff_line_prefix(opt);
2966
2967        while (dir->nr) {
2968                struct dirstat_file *f = dir->files;
2969                int namelen = strlen(f->name);
2970                unsigned long changes;
2971                char *slash;
2972
2973                if (namelen < baselen)
2974                        break;
2975                if (memcmp(f->name, base, baselen))
2976                        break;
2977                slash = strchr(f->name + baselen, '/');
2978                if (slash) {
2979                        int newbaselen = slash + 1 - f->name;
2980                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2981                        sources++;
2982                } else {
2983                        changes = f->changed;
2984                        dir->files++;
2985                        dir->nr--;
2986                        sources += 2;
2987                }
2988                sum_changes += changes;
2989        }
2990
2991        /*
2992         * We don't report dirstat's for
2993         *  - the top level
2994         *  - or cases where everything came from a single directory
2995         *    under this directory (sources == 1).
2996         */
2997        if (baselen && sources != 1) {
2998                if (sum_changes) {
2999                        int permille = sum_changes * 1000 / changed;
3000                        if (permille >= dir->permille) {
3001                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
3002                                        permille / 10, permille % 10, baselen, base);
3003                                if (!dir->cumulative)
3004                                        return 0;
3005                        }
3006                }
3007        }
3008        return sum_changes;
3009}
3010
3011static int dirstat_compare(const void *_a, const void *_b)
3012{
3013        const struct dirstat_file *a = _a;
3014        const struct dirstat_file *b = _b;
3015        return strcmp(a->name, b->name);
3016}
3017
3018static void show_dirstat(struct diff_options *options)
3019{
3020        int i;
3021        unsigned long changed;
3022        struct dirstat_dir dir;
3023        struct diff_queue_struct *q = &diff_queued_diff;
3024
3025        dir.files = NULL;
3026        dir.alloc = 0;
3027        dir.nr = 0;
3028        dir.permille = options->dirstat_permille;
3029        dir.cumulative = options->flags.dirstat_cumulative;
3030
3031        changed = 0;
3032        for (i = 0; i < q->nr; i++) {
3033                struct diff_filepair *p = q->queue[i];
3034                const char *name;
3035                unsigned long copied, added, damage;
3036
3037                name = p->two->path ? p->two->path : p->one->path;
3038
3039                if (p->one->oid_valid && p->two->oid_valid &&
3040                    oideq(&p->one->oid, &p->two->oid)) {
3041                        /*
3042                         * The SHA1 has not changed, so pre-/post-content is
3043                         * identical. We can therefore skip looking at the
3044                         * file contents altogether.
3045                         */
3046                        damage = 0;
3047                        goto found_damage;
3048                }
3049
3050                if (options->flags.dirstat_by_file) {
3051                        /*
3052                         * In --dirstat-by-file mode, we don't really need to
3053                         * look at the actual file contents at all.
3054                         * The fact that the SHA1 changed is enough for us to
3055                         * add this file to the list of results
3056                         * (with each file contributing equal damage).
3057                         */
3058                        damage = 1;
3059                        goto found_damage;
3060                }
3061
3062                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
3063                        diff_populate_filespec(options->repo, p->one, 0);
3064                        diff_populate_filespec(options->repo, p->two, 0);
3065                        diffcore_count_changes(options->repo,
3066                                               p->one, p->two, NULL, NULL,
3067                                               &copied, &added);
3068                        diff_free_filespec_data(p->one);
3069                        diff_free_filespec_data(p->two);
3070                } else if (DIFF_FILE_VALID(p->one)) {
3071                        diff_populate_filespec(options->repo, p->one, CHECK_SIZE_ONLY);
3072                        copied = added = 0;
3073                        diff_free_filespec_data(p->one);
3074                } else if (DIFF_FILE_VALID(p->two)) {
3075                        diff_populate_filespec(options->repo, p->two, CHECK_SIZE_ONLY);
3076                        copied = 0;
3077                        added = p->two->size;
3078                        diff_free_filespec_data(p->two);
3079                } else
3080                        continue;
3081
3082                /*
3083                 * Original minus copied is the removed material,
3084                 * added is the new material.  They are both damages
3085                 * made to the preimage.
3086                 * If the resulting damage is zero, we know that
3087                 * diffcore_count_changes() considers the two entries to
3088                 * be identical, but since the oid changed, we
3089                 * know that there must have been _some_ kind of change,
3090                 * so we force all entries to have damage > 0.
3091                 */
3092                damage = (p->one->size - copied) + added;
3093                if (!damage)
3094                        damage = 1;
3095
3096found_damage:
3097                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3098                dir.files[dir.nr].name = name;
3099                dir.files[dir.nr].changed = damage;
3100                changed += damage;
3101                dir.nr++;
3102        }
3103
3104        /* This can happen even with many files, if everything was renames */
3105        if (!changed)
3106                return;
3107
3108        /* Show all directories with more than x% of the changes */
3109        QSORT(dir.files, dir.nr, dirstat_compare);
3110        gather_dirstat(options, &dir, changed, "", 0);
3111}
3112
3113static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
3114{
3115        int i;
3116        unsigned long changed;
3117        struct dirstat_dir dir;
3118
3119        if (data->nr == 0)
3120                return;
3121
3122        dir.files = NULL;
3123        dir.alloc = 0;
3124        dir.nr = 0;
3125        dir.permille = options->dirstat_permille;
3126        dir.cumulative = options->flags.dirstat_cumulative;
3127
3128        changed = 0;
3129        for (i = 0; i < data->nr; i++) {
3130                struct diffstat_file *file = data->files[i];
3131                unsigned long damage = file->added + file->deleted;
3132                if (file->is_binary)
3133                        /*
3134                         * binary files counts bytes, not lines. Must find some
3135                         * way to normalize binary bytes vs. textual lines.
3136                         * The following heuristic assumes that there are 64
3137                         * bytes per "line".
3138                         * This is stupid and ugly, but very cheap...
3139                         */
3140                        damage = DIV_ROUND_UP(damage, 64);
3141                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3142                dir.files[dir.nr].name = file->name;
3143                dir.files[dir.nr].changed = damage;
3144                changed += damage;
3145                dir.nr++;
3146        }
3147
3148        /* This can happen even with many files, if everything was renames */
3149        if (!changed)
3150                return;
3151
3152        /* Show all directories with more than x% of the changes */
3153        QSORT(dir.files, dir.nr, dirstat_compare);
3154        gather_dirstat(options, &dir, changed, "", 0);
3155}
3156
3157static void free_diffstat_info(struct diffstat_t *diffstat)
3158{
3159        int i;
3160        for (i = 0; i < diffstat->nr; i++) {
3161                struct diffstat_file *f = diffstat->files[i];
3162                free(f->print_name);
3163                free(f->name);
3164                free(f->from_name);
3165                free(f);
3166        }
3167        free(diffstat->files);
3168}
3169
3170struct checkdiff_t {
3171        const char *filename;
3172        int lineno;
3173        int conflict_marker_size;
3174        struct diff_options *o;
3175        unsigned ws_rule;
3176        unsigned status;
3177};
3178
3179static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3180{
3181        char firstchar;
3182        int cnt;
3183
3184        if (len < marker_size + 1)
3185                return 0;
3186        firstchar = line[0];
3187        switch (firstchar) {
3188        case '=': case '>': case '<': case '|':
3189                break;
3190        default:
3191                return 0;
3192        }
3193        for (cnt = 1; cnt < marker_size; cnt++)
3194                if (line[cnt] != firstchar)
3195                        return 0;
3196        /* line[1] thru line[marker_size-1] are same as firstchar */
3197        if (len < marker_size + 1 || !isspace(line[marker_size]))
3198                return 0;
3199        return 1;
3200}
3201
3202static void checkdiff_consume_hunk(void *priv,
3203                                   long ob, long on, long nb, long nn,
3204                                   const char *func, long funclen)
3205
3206{
3207        struct checkdiff_t *data = priv;
3208        data->lineno = nb - 1;
3209}
3210
3211static void checkdiff_consume(void *priv, char *line, unsigned long len)
3212{
3213        struct checkdiff_t *data = priv;
3214        int marker_size = data->conflict_marker_size;
3215        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3216        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3217        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3218        char *err;
3219        const char *line_prefix;
3220
3221        assert(data->o);
3222        line_prefix = diff_line_prefix(data->o);
3223
3224        if (line[0] == '+') {
3225                unsigned bad;
3226                data->lineno++;
3227                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3228                        data->status |= 1;
3229                        fprintf(data->o->file,
3230                                "%s%s:%d: leftover conflict marker\n",
3231                                line_prefix, data->filename, data->lineno);
3232                }
3233                bad = ws_check(line + 1, len - 1, data->ws_rule);
3234                if (!bad)
3235                        return;
3236                data->status |= bad;
3237                err = whitespace_error_string(bad);
3238                fprintf(data->o->file, "%s%s:%d: %s.\n",
3239                        line_prefix, data->filename, data->lineno, err);
3240                free(err);
3241                emit_line(data->o, set, reset, line, 1);
3242                ws_check_emit(line + 1, len - 1, data->ws_rule,
3243                              data->o->file, set, reset, ws);
3244        } else if (line[0] == ' ') {
3245                data->lineno++;
3246        }
3247}
3248
3249static unsigned char *deflate_it(char *data,
3250                                 unsigned long size,
3251                                 unsigned long *result_size)
3252{
3253        int bound;
3254        unsigned char *deflated;
3255        git_zstream stream;
3256
3257        git_deflate_init(&stream, zlib_compression_level);
3258        bound = git_deflate_bound(&stream, size);
3259        deflated = xmalloc(bound);
3260        stream.next_out = deflated;
3261        stream.avail_out = bound;
3262
3263        stream.next_in = (unsigned char *)data;
3264        stream.avail_in = size;
3265        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3266                ; /* nothing */
3267        git_deflate_end(&stream);
3268        *result_size = stream.total_out;
3269        return deflated;
3270}
3271
3272static void emit_binary_diff_body(struct diff_options *o,
3273                                  mmfile_t *one, mmfile_t *two)
3274{
3275        void *cp;
3276        void *delta;
3277        void *deflated;
3278        void *data;
3279        unsigned long orig_size;
3280        unsigned long delta_size;
3281        unsigned long deflate_size;
3282        unsigned long data_size;
3283
3284        /* We could do deflated delta, or we could do just deflated two,
3285         * whichever is smaller.
3286         */
3287        delta = NULL;
3288        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3289        if (one->size && two->size) {
3290                delta = diff_delta(one->ptr, one->size,
3291                                   two->ptr, two->size,
3292                                   &delta_size, deflate_size);
3293                if (delta) {
3294                        void *to_free = delta;
3295                        orig_size = delta_size;
3296                        delta = deflate_it(delta, delta_size, &delta_size);
3297                        free(to_free);
3298                }
3299        }
3300
3301        if (delta && delta_size < deflate_size) {
3302                char *s = xstrfmt("%"PRIuMAX , (uintmax_t)orig_size);
3303                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3304                                 s, strlen(s), 0);
3305                free(s);
3306                free(deflated);
3307                data = delta;
3308                data_size = delta_size;
3309        } else {
3310                char *s = xstrfmt("%lu", two->size);
3311                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3312                                 s, strlen(s), 0);
3313                free(s);
3314                free(delta);
3315                data = deflated;
3316                data_size = deflate_size;
3317        }
3318
3319        /* emit data encoded in base85 */
3320        cp = data;
3321        while (data_size) {
3322                int len;
3323                int bytes = (52 < data_size) ? 52 : data_size;
3324                char line[71];
3325                data_size -= bytes;
3326                if (bytes <= 26)
3327                        line[0] = bytes + 'A' - 1;
3328                else
3329                        line[0] = bytes - 26 + 'a' - 1;
3330                encode_85(line + 1, cp, bytes);
3331                cp = (char *) cp + bytes;
3332
3333                len = strlen(line);
3334                line[len++] = '\n';
3335                line[len] = '\0';
3336
3337                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3338                                 line, len, 0);
3339        }
3340        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3341        free(data);
3342}
3343
3344static void emit_binary_diff(struct diff_options *o,
3345                             mmfile_t *one, mmfile_t *two)
3346{
3347        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3348        emit_binary_diff_body(o, one, two);
3349        emit_binary_diff_body(o, two, one);
3350}
3351
3352int diff_filespec_is_binary(struct repository *r,
3353                            struct diff_filespec *one)
3354{
3355        if (one->is_binary == -1) {
3356                diff_filespec_load_driver(one, r->index);
3357                if (one->driver->binary != -1)
3358                        one->is_binary = one->driver->binary;
3359                else {
3360                        if (!one->data && DIFF_FILE_VALID(one))
3361                                diff_populate_filespec(r, one, CHECK_BINARY);
3362                        if (one->is_binary == -1 && one->data)
3363                                one->is_binary = buffer_is_binary(one->data,
3364                                                one->size);
3365                        if (one->is_binary == -1)
3366                                one->is_binary = 0;
3367                }
3368        }
3369        return one->is_binary;
3370}
3371
3372static const struct userdiff_funcname *
3373diff_funcname_pattern(struct diff_options *o, struct diff_filespec *one)
3374{
3375        diff_filespec_load_driver(one, o->repo->index);
3376        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3377}
3378
3379void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3380{
3381        if (!options->a_prefix)
3382                options->a_prefix = a;
3383        if (!options->b_prefix)
3384                options->b_prefix = b;
3385}
3386
3387struct userdiff_driver *get_textconv(struct repository *r,
3388                                     struct diff_filespec *one)
3389{
3390        if (!DIFF_FILE_VALID(one))
3391                return NULL;
3392
3393        diff_filespec_load_driver(one, r->index);
3394        return userdiff_get_textconv(r, one->driver);
3395}
3396
3397static void builtin_diff(const char *name_a,
3398                         const char *name_b,
3399                         struct diff_filespec *one,
3400                         struct diff_filespec *two,
3401                         const char *xfrm_msg,
3402                         int must_show_header,
3403                         struct diff_options *o,
3404                         int complete_rewrite)
3405{
3406        mmfile_t mf1, mf2;
3407        const char *lbl[2];
3408        char *a_one, *b_two;
3409        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3410        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3411        const char *a_prefix, *b_prefix;
3412        struct userdiff_driver *textconv_one = NULL;
3413        struct userdiff_driver *textconv_two = NULL;
3414        struct strbuf header = STRBUF_INIT;
3415        const char *line_prefix = diff_line_prefix(o);
3416
3417        diff_set_mnemonic_prefix(o, "a/", "b/");
3418        if (o->flags.reverse_diff) {
3419                a_prefix = o->b_prefix;
3420                b_prefix = o->a_prefix;
3421        } else {
3422                a_prefix = o->a_prefix;
3423                b_prefix = o->b_prefix;
3424        }
3425
3426        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3427            (!one->mode || S_ISGITLINK(one->mode)) &&
3428            (!two->mode || S_ISGITLINK(two->mode))) {
3429                show_submodule_summary(o, one->path ? one->path : two->path,
3430                                &one->oid, &two->oid,
3431                                two->dirty_submodule);
3432                return;
3433        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3434                   (!one->mode || S_ISGITLINK(one->mode)) &&
3435                   (!two->mode || S_ISGITLINK(two->mode))) {
3436                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3437                                &one->oid, &two->oid,
3438                                two->dirty_submodule);
3439                return;
3440        }
3441
3442        if (o->flags.allow_textconv) {
3443                textconv_one = get_textconv(o->repo, one);
3444                textconv_two = get_textconv(o->repo, two);
3445        }
3446
3447        /* Never use a non-valid filename anywhere if at all possible */
3448        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3449        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3450
3451        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3452        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3453        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3454        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3455        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3456        if (lbl[0][0] == '/') {
3457                /* /dev/null */
3458                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3459                if (xfrm_msg)
3460                        strbuf_addstr(&header, xfrm_msg);
3461                must_show_header = 1;
3462        }
3463        else if (lbl[1][0] == '/') {
3464                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3465                if (xfrm_msg)
3466                        strbuf_addstr(&header, xfrm_msg);
3467                must_show_header = 1;
3468        }
3469        else {
3470                if (one->mode != two->mode) {
3471                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3472                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3473                        must_show_header = 1;
3474                }
3475                if (xfrm_msg)
3476                        strbuf_addstr(&header, xfrm_msg);
3477
3478                /*
3479                 * we do not run diff between different kind
3480                 * of objects.
3481                 */
3482                if ((one->mode ^ two->mode) & S_IFMT)
3483                        goto free_ab_and_return;
3484                if (complete_rewrite &&
3485                    (textconv_one || !diff_filespec_is_binary(o->repo, one)) &&
3486                    (textconv_two || !diff_filespec_is_binary(o->repo, two))) {
3487                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3488                                         header.buf, header.len, 0);
3489                        strbuf_reset(&header);
3490                        emit_rewrite_diff(name_a, name_b, one, two,
3491                                          textconv_one, textconv_two, o);
3492                        o->found_changes = 1;
3493                        goto free_ab_and_return;
3494                }
3495        }
3496
3497        if (o->irreversible_delete && lbl[1][0] == '/') {
3498                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3499                                 header.len, 0);
3500                strbuf_reset(&header);
3501                goto free_ab_and_return;
3502        } else if (!o->flags.text &&
3503                   ( (!textconv_one && diff_filespec_is_binary(o->repo, one)) ||
3504                     (!textconv_two && diff_filespec_is_binary(o->repo, two)) )) {
3505                struct strbuf sb = STRBUF_INIT;
3506                if (!one->data && !two->data &&
3507                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3508                    !o->flags.binary) {
3509                        if (oideq(&one->oid, &two->oid)) {
3510                                if (must_show_header)
3511                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3512                                                         header.buf, header.len,
3513                                                         0);
3514                                goto free_ab_and_return;
3515                        }
3516                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3517                                         header.buf, header.len, 0);
3518                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3519                                    diff_line_prefix(o), lbl[0], lbl[1]);
3520                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3521                                         sb.buf, sb.len, 0);
3522                        strbuf_release(&sb);
3523                        goto free_ab_and_return;
3524                }
3525                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3526                    fill_mmfile(o->repo, &mf2, two) < 0)
3527                        die("unable to read files to diff");
3528                /* Quite common confusing case */
3529                if (mf1.size == mf2.size &&
3530                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3531                        if (must_show_header)
3532                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3533                                                 header.buf, header.len, 0);
3534                        goto free_ab_and_return;
3535                }
3536                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3537                strbuf_reset(&header);
3538                if (o->flags.binary)
3539                        emit_binary_diff(o, &mf1, &mf2);
3540                else {
3541                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3542                                    diff_line_prefix(o), lbl[0], lbl[1]);
3543                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3544                                         sb.buf, sb.len, 0);
3545                        strbuf_release(&sb);
3546                }
3547                o->found_changes = 1;
3548        } else {
3549                /* Crazy xdl interfaces.. */
3550                const char *diffopts;
3551                const char *v;
3552                xpparam_t xpp;
3553                xdemitconf_t xecfg;
3554                struct emit_callback ecbdata;
3555                const struct userdiff_funcname *pe;
3556
3557                if (must_show_header) {
3558                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3559                                         header.buf, header.len, 0);
3560                        strbuf_reset(&header);
3561                }
3562
3563                mf1.size = fill_textconv(o->repo, textconv_one, one, &mf1.ptr);
3564                mf2.size = fill_textconv(o->repo, textconv_two, two, &mf2.ptr);
3565
3566                pe = diff_funcname_pattern(o, one);
3567                if (!pe)
3568                        pe = diff_funcname_pattern(o, two);
3569
3570                memset(&xpp, 0, sizeof(xpp));
3571                memset(&xecfg, 0, sizeof(xecfg));
3572                memset(&ecbdata, 0, sizeof(ecbdata));
3573                if (o->flags.suppress_diff_headers)
3574                        lbl[0] = NULL;
3575                ecbdata.label_path = lbl;
3576                ecbdata.color_diff = want_color(o->use_color);
3577                ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
3578                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3579                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3580                ecbdata.opt = o;
3581                if (header.len && !o->flags.suppress_diff_headers)
3582                        ecbdata.header = &header;
3583                xpp.flags = o->xdl_opts;
3584                xpp.anchors = o->anchors;
3585                xpp.anchors_nr = o->anchors_nr;
3586                xecfg.ctxlen = o->context;
3587                xecfg.interhunkctxlen = o->interhunkcontext;
3588                xecfg.flags = XDL_EMIT_FUNCNAMES;
3589                if (o->flags.funccontext)
3590                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3591                if (pe)
3592                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3593
3594                diffopts = getenv("GIT_DIFF_OPTS");
3595                if (!diffopts)
3596                        ;
3597                else if (skip_prefix(diffopts, "--unified=", &v))
3598                        xecfg.ctxlen = strtoul(v, NULL, 10);
3599                else if (skip_prefix(diffopts, "-u", &v))
3600                        xecfg.ctxlen = strtoul(v, NULL, 10);
3601
3602                if (o->word_diff)
3603                        init_diff_words_data(&ecbdata, o, one, two);
3604                if (xdi_diff_outf(&mf1, &mf2, NULL, fn_out_consume,
3605                                  &ecbdata, &xpp, &xecfg))
3606                        die("unable to generate diff for %s", one->path);
3607                if (o->word_diff)
3608                        free_diff_words_data(&ecbdata);
3609                if (textconv_one)
3610                        free(mf1.ptr);
3611                if (textconv_two)
3612                        free(mf2.ptr);
3613                xdiff_clear_find_func(&xecfg);
3614        }
3615
3616 free_ab_and_return:
3617        strbuf_release(&header);
3618        diff_free_filespec_data(one);
3619        diff_free_filespec_data(two);
3620        free(a_one);
3621        free(b_two);
3622        return;
3623}
3624
3625static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3626{
3627        if (!is_renamed) {
3628                if (p->status == DIFF_STATUS_ADDED) {
3629                        if (S_ISLNK(p->two->mode))
3630                                return "new +l";
3631                        else if ((p->two->mode & 0777) == 0755)
3632                                return "new +x";
3633                        else
3634                                return "new";
3635                } else if (p->status == DIFF_STATUS_DELETED)
3636                        return "gone";
3637        }
3638        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3639                return "mode -l";
3640        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3641                return "mode +l";
3642        else if ((p->one->mode & 0777) == 0644 &&
3643                 (p->two->mode & 0777) == 0755)
3644                return "mode +x";
3645        else if ((p->one->mode & 0777) == 0755 &&
3646                 (p->two->mode & 0777) == 0644)
3647                return "mode -x";
3648        return NULL;
3649}
3650
3651static void builtin_diffstat(const char *name_a, const char *name_b,
3652                             struct diff_filespec *one,
3653                             struct diff_filespec *two,
3654                             struct diffstat_t *diffstat,
3655                             struct diff_options *o,
3656                             struct diff_filepair *p)
3657{
3658        mmfile_t mf1, mf2;
3659        struct diffstat_file *data;
3660        int same_contents;
3661        int complete_rewrite = 0;
3662
3663        if (!DIFF_PAIR_UNMERGED(p)) {
3664                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3665                        complete_rewrite = 1;
3666        }
3667
3668        data = diffstat_add(diffstat, name_a, name_b);
3669        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3670        if (o->flags.stat_with_summary)
3671                data->comments = get_compact_summary(p, data->is_renamed);
3672
3673        if (!one || !two) {
3674                data->is_unmerged = 1;
3675                return;
3676        }
3677
3678        same_contents = oideq(&one->oid, &two->oid);
3679
3680        if (diff_filespec_is_binary(o->repo, one) ||
3681            diff_filespec_is_binary(o->repo, two)) {
3682                data->is_binary = 1;
3683                if (same_contents) {
3684                        data->added = 0;
3685                        data->deleted = 0;
3686                } else {
3687                        data->added = diff_filespec_size(o->repo, two);
3688                        data->deleted = diff_filespec_size(o->repo, one);
3689                }
3690        }
3691
3692        else if (complete_rewrite) {
3693                diff_populate_filespec(o->repo, one, 0);
3694                diff_populate_filespec(o->repo, two, 0);
3695                data->deleted = count_lines(one->data, one->size);
3696                data->added = count_lines(two->data, two->size);
3697        }
3698
3699        else if (!same_contents) {
3700                /* Crazy xdl interfaces.. */
3701                xpparam_t xpp;
3702                xdemitconf_t xecfg;
3703
3704                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3705                    fill_mmfile(o->repo, &mf2, two) < 0)
3706                        die("unable to read files to diff");
3707
3708                memset(&xpp, 0, sizeof(xpp));
3709                memset(&xecfg, 0, sizeof(xecfg));
3710                xpp.flags = o->xdl_opts;
3711                xpp.anchors = o->anchors;
3712                xpp.anchors_nr = o->anchors_nr;
3713                xecfg.ctxlen = o->context;
3714                xecfg.interhunkctxlen = o->interhunkcontext;
3715                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
3716                                  diffstat_consume, diffstat, &xpp, &xecfg))
3717                        die("unable to generate diffstat for %s", one->path);
3718        }
3719
3720        diff_free_filespec_data(one);
3721        diff_free_filespec_data(two);
3722}
3723
3724static void builtin_checkdiff(const char *name_a, const char *name_b,
3725                              const char *attr_path,
3726                              struct diff_filespec *one,
3727                              struct diff_filespec *two,
3728                              struct diff_options *o)
3729{
3730        mmfile_t mf1, mf2;
3731        struct checkdiff_t data;
3732
3733        if (!two)
3734                return;
3735
3736        memset(&data, 0, sizeof(data));
3737        data.filename = name_b ? name_b : name_a;
3738        data.lineno = 0;
3739        data.o = o;
3740        data.ws_rule = whitespace_rule(o->repo->index, attr_path);
3741        data.conflict_marker_size = ll_merge_marker_size(o->repo->index, attr_path);
3742
3743        if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3744            fill_mmfile(o->repo, &mf2, two) < 0)
3745                die("unable to read files to diff");
3746
3747        /*
3748         * All the other codepaths check both sides, but not checking
3749         * the "old" side here is deliberate.  We are checking the newly
3750         * introduced changes, and as long as the "new" side is text, we
3751         * can and should check what it introduces.
3752         */
3753        if (diff_filespec_is_binary(o->repo, two))
3754                goto free_and_return;
3755        else {
3756                /* Crazy xdl interfaces.. */
3757                xpparam_t xpp;
3758                xdemitconf_t xecfg;
3759
3760                memset(&xpp, 0, sizeof(xpp));
3761                memset(&xecfg, 0, sizeof(xecfg));
3762                xecfg.ctxlen = 1; /* at least one context line */
3763                xpp.flags = 0;
3764                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume_hunk,
3765                                  checkdiff_consume, &data,
3766                                  &xpp, &xecfg))
3767                        die("unable to generate checkdiff for %s", one->path);
3768
3769                if (data.ws_rule & WS_BLANK_AT_EOF) {
3770                        struct emit_callback ecbdata;
3771                        int blank_at_eof;
3772
3773                        ecbdata.ws_rule = data.ws_rule;
3774                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3775                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3776
3777                        if (blank_at_eof) {
3778                                static char *err;
3779                                if (!err)
3780                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3781                                fprintf(o->file, "%s:%d: %s.\n",
3782                                        data.filename, blank_at_eof, err);
3783                                data.status = 1; /* report errors */
3784                        }
3785                }
3786        }
3787 free_and_return:
3788        diff_free_filespec_data(one);
3789        diff_free_filespec_data(two);
3790        if (data.status)
3791                o->flags.check_failed = 1;
3792}
3793
3794struct diff_filespec *alloc_filespec(const char *path)
3795{
3796        struct diff_filespec *spec;
3797
3798        FLEXPTR_ALLOC_STR(spec, path, path);
3799        spec->count = 1;
3800        spec->is_binary = -1;
3801        return spec;
3802}
3803
3804void free_filespec(struct diff_filespec *spec)
3805{
3806        if (!--spec->count) {
3807                diff_free_filespec_data(spec);
3808                free(spec);
3809        }
3810}
3811
3812void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3813                   int oid_valid, unsigned short mode)
3814{
3815        if (mode) {
3816                spec->mode = canon_mode(mode);
3817                oidcpy(&spec->oid, oid);
3818                spec->oid_valid = oid_valid;
3819        }
3820}
3821
3822/*
3823 * Given a name and sha1 pair, if the index tells us the file in
3824 * the work tree has that object contents, return true, so that
3825 * prepare_temp_file() does not have to inflate and extract.
3826 */
3827static int reuse_worktree_file(struct index_state *istate,
3828                               const char *name,
3829                               const struct object_id *oid,
3830                               int want_file)
3831{
3832        const struct cache_entry *ce;
3833        struct stat st;
3834        int pos, len;
3835
3836        /*
3837         * We do not read the cache ourselves here, because the
3838         * benchmark with my previous version that always reads cache
3839         * shows that it makes things worse for diff-tree comparing
3840         * two linux-2.6 kernel trees in an already checked out work
3841         * tree.  This is because most diff-tree comparisons deal with
3842         * only a small number of files, while reading the cache is
3843         * expensive for a large project, and its cost outweighs the
3844         * savings we get by not inflating the object to a temporary
3845         * file.  Practically, this code only helps when we are used
3846         * by diff-cache --cached, which does read the cache before
3847         * calling us.
3848         */
3849        if (!istate->cache)
3850                return 0;
3851
3852        /* We want to avoid the working directory if our caller
3853         * doesn't need the data in a normal file, this system
3854         * is rather slow with its stat/open/mmap/close syscalls,
3855         * and the object is contained in a pack file.  The pack
3856         * is probably already open and will be faster to obtain
3857         * the data through than the working directory.  Loose
3858         * objects however would tend to be slower as they need
3859         * to be individually opened and inflated.
3860         */
3861        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3862                return 0;
3863
3864        /*
3865         * Similarly, if we'd have to convert the file contents anyway, that
3866         * makes the optimization not worthwhile.
3867         */
3868        if (!want_file && would_convert_to_git(istate, name))
3869                return 0;
3870
3871        len = strlen(name);
3872        pos = index_name_pos(istate, name, len);
3873        if (pos < 0)
3874                return 0;
3875        ce = istate->cache[pos];
3876
3877        /*
3878         * This is not the sha1 we are looking for, or
3879         * unreusable because it is not a regular file.
3880         */
3881        if (!oideq(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3882                return 0;
3883
3884        /*
3885         * If ce is marked as "assume unchanged", there is no
3886         * guarantee that work tree matches what we are looking for.
3887         */
3888        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3889                return 0;
3890
3891        /*
3892         * If ce matches the file in the work tree, we can reuse it.
3893         */
3894        if (ce_uptodate(ce) ||
3895            (!lstat(name, &st) && !ie_match_stat(istate, ce, &st, 0)))
3896                return 1;
3897
3898        return 0;
3899}
3900
3901static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3902{
3903        struct strbuf buf = STRBUF_INIT;
3904        char *dirty = "";
3905
3906        /* Are we looking at the work tree? */
3907        if (s->dirty_submodule)
3908                dirty = "-dirty";
3909
3910        strbuf_addf(&buf, "Subproject commit %s%s\n",
3911                    oid_to_hex(&s->oid), dirty);
3912        s->size = buf.len;
3913        if (size_only) {
3914                s->data = NULL;
3915                strbuf_release(&buf);
3916        } else {
3917                s->data = strbuf_detach(&buf, NULL);
3918                s->should_free = 1;
3919        }
3920        return 0;
3921}
3922
3923/*
3924 * While doing rename detection and pickaxe operation, we may need to
3925 * grab the data for the blob (or file) for our own in-core comparison.
3926 * diff_filespec has data and size fields for this purpose.
3927 */
3928int diff_populate_filespec(struct repository *r,
3929                           struct diff_filespec *s,
3930                           unsigned int flags)
3931{
3932        int size_only = flags & CHECK_SIZE_ONLY;
3933        int err = 0;
3934        int conv_flags = global_conv_flags_eol;
3935        /*
3936         * demote FAIL to WARN to allow inspecting the situation
3937         * instead of refusing.
3938         */
3939        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3940                conv_flags = CONV_EOL_RNDTRP_WARN;
3941
3942        if (!DIFF_FILE_VALID(s))
3943                die("internal error: asking to populate invalid file.");
3944        if (S_ISDIR(s->mode))
3945                return -1;
3946
3947        if (s->data)
3948                return 0;
3949
3950        if (size_only && 0 < s->size)
3951                return 0;
3952
3953        if (S_ISGITLINK(s->mode))
3954                return diff_populate_gitlink(s, size_only);
3955
3956        if (!s->oid_valid ||
3957            reuse_worktree_file(r->index, s->path, &s->oid, 0)) {
3958                struct strbuf buf = STRBUF_INIT;
3959                struct stat st;
3960                int fd;
3961
3962                if (lstat(s->path, &st) < 0) {
3963                err_empty:
3964                        err = -1;
3965                empty:
3966                        s->data = (char *)"";
3967                        s->size = 0;
3968                        return err;
3969                }
3970                s->size = xsize_t(st.st_size);
3971                if (!s->size)
3972                        goto empty;
3973                if (S_ISLNK(st.st_mode)) {
3974                        struct strbuf sb = STRBUF_INIT;
3975
3976                        if (strbuf_readlink(&sb, s->path, s->size))
3977                                goto err_empty;
3978                        s->size = sb.len;
3979                        s->data = strbuf_detach(&sb, NULL);
3980                        s->should_free = 1;
3981                        return 0;
3982                }
3983
3984                /*
3985                 * Even if the caller would be happy with getting
3986                 * only the size, we cannot return early at this
3987                 * point if the path requires us to run the content
3988                 * conversion.
3989                 */
3990                if (size_only && !would_convert_to_git(r->index, s->path))
3991                        return 0;
3992
3993                /*
3994                 * Note: this check uses xsize_t(st.st_size) that may
3995                 * not be the true size of the blob after it goes
3996                 * through convert_to_git().  This may not strictly be
3997                 * correct, but the whole point of big_file_threshold
3998                 * and is_binary check being that we want to avoid
3999                 * opening the file and inspecting the contents, this
4000                 * is probably fine.
4001                 */
4002                if ((flags & CHECK_BINARY) &&
4003                    s->size > big_file_threshold && s->is_binary == -1) {
4004                        s->is_binary = 1;
4005                        return 0;
4006                }
4007                fd = open(s->path, O_RDONLY);
4008                if (fd < 0)
4009                        goto err_empty;
4010                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
4011                close(fd);
4012                s->should_munmap = 1;
4013
4014                /*
4015                 * Convert from working tree format to canonical git format
4016                 */
4017                if (convert_to_git(r->index, s->path, s->data, s->size, &buf, conv_flags)) {
4018                        size_t size = 0;
4019                        munmap(s->data, s->size);
4020                        s->should_munmap = 0;
4021                        s->data = strbuf_detach(&buf, &size);
4022                        s->size = size;
4023                        s->should_free = 1;
4024                }
4025        }
4026        else {
4027                enum object_type type;
4028                if (size_only || (flags & CHECK_BINARY)) {
4029                        type = oid_object_info(r, &s->oid, &s->size);
4030                        if (type < 0)
4031                                die("unable to read %s",
4032                                    oid_to_hex(&s->oid));
4033                        if (size_only)
4034                                return 0;
4035                        if (s->size > big_file_threshold && s->is_binary == -1) {
4036                                s->is_binary = 1;
4037                                return 0;
4038                        }
4039                }
4040                s->data = read_object_file(&s->oid, &type, &s->size);
4041                if (!s->data)
4042                        die("unable to read %s", oid_to_hex(&s->oid));
4043                s->should_free = 1;
4044        }
4045        return 0;
4046}
4047
4048void diff_free_filespec_blob(struct diff_filespec *s)
4049{
4050        if (s->should_free)
4051                free(s->data);
4052        else if (s->should_munmap)
4053                munmap(s->data, s->size);
4054
4055        if (s->should_free || s->should_munmap) {
4056                s->should_free = s->should_munmap = 0;
4057                s->data = NULL;
4058        }
4059}
4060
4061void diff_free_filespec_data(struct diff_filespec *s)
4062{
4063        diff_free_filespec_blob(s);
4064        FREE_AND_NULL(s->cnt_data);
4065}
4066
4067static void prep_temp_blob(struct index_state *istate,
4068                           const char *path, struct diff_tempfile *temp,
4069                           void *blob,
4070                           unsigned long size,
4071                           const struct object_id *oid,
4072                           int mode)
4073{
4074        struct strbuf buf = STRBUF_INIT;
4075        struct strbuf tempfile = STRBUF_INIT;
4076        char *path_dup = xstrdup(path);
4077        const char *base = basename(path_dup);
4078
4079        /* Generate "XXXXXX_basename.ext" */
4080        strbuf_addstr(&tempfile, "XXXXXX_");
4081        strbuf_addstr(&tempfile, base);
4082
4083        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
4084        if (!temp->tempfile)
4085                die_errno("unable to create temp-file");
4086        if (convert_to_working_tree(istate, path,
4087                        (const char *)blob, (size_t)size, &buf)) {
4088                blob = buf.buf;
4089                size = buf.len;
4090        }
4091        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
4092            close_tempfile_gently(temp->tempfile))
4093                die_errno("unable to write temp-file");
4094        temp->name = get_tempfile_path(temp->tempfile);
4095        oid_to_hex_r(temp->hex, oid);
4096        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
4097        strbuf_release(&buf);
4098        strbuf_release(&tempfile);
4099        free(path_dup);
4100}
4101
4102static struct diff_tempfile *prepare_temp_file(struct repository *r,
4103                                               const char *name,
4104                                               struct diff_filespec *one)
4105{
4106        struct diff_tempfile *temp = claim_diff_tempfile();
4107
4108        if (!DIFF_FILE_VALID(one)) {
4109        not_a_valid_file:
4110                /* A '-' entry produces this for file-2, and
4111                 * a '+' entry produces this for file-1.
4112                 */
4113                temp->name = "/dev/null";
4114                xsnprintf(temp->hex, sizeof(temp->hex), ".");
4115                xsnprintf(temp->mode, sizeof(temp->mode), ".");
4116                return temp;
4117        }
4118
4119        if (!S_ISGITLINK(one->mode) &&
4120            (!one->oid_valid ||
4121             reuse_worktree_file(r->index, name, &one->oid, 1))) {
4122                struct stat st;
4123                if (lstat(name, &st) < 0) {
4124                        if (errno == ENOENT)
4125                                goto not_a_valid_file;
4126                        die_errno("stat(%s)", name);
4127                }
4128                if (S_ISLNK(st.st_mode)) {
4129                        struct strbuf sb = STRBUF_INIT;
4130                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
4131                                die_errno("readlink(%s)", name);
4132                        prep_temp_blob(r->index, name, temp, sb.buf, sb.len,
4133                                       (one->oid_valid ?
4134                                        &one->oid : &null_oid),
4135                                       (one->oid_valid ?
4136                                        one->mode : S_IFLNK));
4137                        strbuf_release(&sb);
4138                }
4139                else {
4140                        /* we can borrow from the file in the work tree */
4141                        temp->name = name;
4142                        if (!one->oid_valid)
4143                                oid_to_hex_r(temp->hex, &null_oid);
4144                        else
4145                                oid_to_hex_r(temp->hex, &one->oid);
4146                        /* Even though we may sometimes borrow the
4147                         * contents from the work tree, we always want
4148                         * one->mode.  mode is trustworthy even when
4149                         * !(one->oid_valid), as long as
4150                         * DIFF_FILE_VALID(one).
4151                         */
4152                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
4153                }
4154                return temp;
4155        }
4156        else {
4157                if (diff_populate_filespec(r, one, 0))
4158                        die("cannot read data blob for %s", one->path);
4159                prep_temp_blob(r->index, name, temp,
4160                               one->data, one->size,
4161                               &one->oid, one->mode);
4162        }
4163        return temp;
4164}
4165
4166static void add_external_diff_name(struct repository *r,
4167                                   struct argv_array *argv,
4168                                   const char *name,
4169                                   struct diff_filespec *df)
4170{
4171        struct diff_tempfile *temp = prepare_temp_file(r, name, df);
4172        argv_array_push(argv, temp->name);
4173        argv_array_push(argv, temp->hex);
4174        argv_array_push(argv, temp->mode);
4175}
4176
4177/* An external diff command takes:
4178 *
4179 * diff-cmd name infile1 infile1-sha1 infile1-mode \
4180 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
4181 *
4182 */
4183static void run_external_diff(const char *pgm,
4184                              const char *name,
4185                              const char *other,
4186                              struct diff_filespec *one,
4187                              struct diff_filespec *two,
4188                              const char *xfrm_msg,
4189                              struct diff_options *o)
4190{
4191        struct argv_array argv = ARGV_ARRAY_INIT;
4192        struct argv_array env = ARGV_ARRAY_INIT;
4193        struct diff_queue_struct *q = &diff_queued_diff;
4194
4195        argv_array_push(&argv, pgm);
4196        argv_array_push(&argv, name);
4197
4198        if (one && two) {
4199                add_external_diff_name(o->repo, &argv, name, one);
4200                if (!other)
4201                        add_external_diff_name(o->repo, &argv, name, two);
4202                else {
4203                        add_external_diff_name(o->repo, &argv, other, two);
4204                        argv_array_push(&argv, other);
4205                        argv_array_push(&argv, xfrm_msg);
4206                }
4207        }
4208
4209        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4210        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4211
4212        diff_free_filespec_data(one);
4213        diff_free_filespec_data(two);
4214        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4215                die(_("external diff died, stopping at %s"), name);
4216
4217        remove_tempfile();
4218        argv_array_clear(&argv);
4219        argv_array_clear(&env);
4220}
4221
4222static int similarity_index(struct diff_filepair *p)
4223{
4224        return p->score * 100 / MAX_SCORE;
4225}
4226
4227static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4228{
4229        if (startup_info->have_repository)
4230                return find_unique_abbrev(oid, abbrev);
4231        else {
4232                char *hex = oid_to_hex(oid);
4233                if (abbrev < 0)
4234                        abbrev = FALLBACK_DEFAULT_ABBREV;
4235                if (abbrev > the_hash_algo->hexsz)
4236                        BUG("oid abbreviation out of range: %d", abbrev);
4237                if (abbrev)
4238                        hex[abbrev] = '\0';
4239                return hex;
4240        }
4241}
4242
4243static void fill_metainfo(struct strbuf *msg,
4244                          const char *name,
4245                          const char *other,
4246                          struct diff_filespec *one,
4247                          struct diff_filespec *two,
4248                          struct diff_options *o,
4249                          struct diff_filepair *p,
4250                          int *must_show_header,
4251                          int use_color)
4252{
4253        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4254        const char *reset = diff_get_color(use_color, DIFF_RESET);
4255        const char *line_prefix = diff_line_prefix(o);
4256
4257        *must_show_header = 1;
4258        strbuf_init(msg, PATH_MAX * 2 + 300);
4259        switch (p->status) {
4260        case DIFF_STATUS_COPIED:
4261                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4262                            line_prefix, set, similarity_index(p));
4263                strbuf_addf(msg, "%s\n%s%scopy from ",
4264                            reset,  line_prefix, set);
4265                quote_c_style(name, msg, NULL, 0);
4266                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4267                quote_c_style(other, msg, NULL, 0);
4268                strbuf_addf(msg, "%s\n", reset);
4269                break;
4270        case DIFF_STATUS_RENAMED:
4271                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4272                            line_prefix, set, similarity_index(p));
4273                strbuf_addf(msg, "%s\n%s%srename from ",
4274                            reset, line_prefix, set);
4275                quote_c_style(name, msg, NULL, 0);
4276                strbuf_addf(msg, "%s\n%s%srename to ",
4277                            reset, line_prefix, set);
4278                quote_c_style(other, msg, NULL, 0);
4279                strbuf_addf(msg, "%s\n", reset);
4280                break;
4281        case DIFF_STATUS_MODIFIED:
4282                if (p->score) {
4283                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4284                                    line_prefix,
4285                                    set, similarity_index(p), reset);
4286                        break;
4287                }
4288                /* fallthru */
4289        default:
4290                *must_show_header = 0;
4291        }
4292        if (one && two && !oideq(&one->oid, &two->oid)) {
4293                const unsigned hexsz = the_hash_algo->hexsz;
4294                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4295
4296                if (o->flags.binary) {
4297                        mmfile_t mf;
4298                        if ((!fill_mmfile(o->repo, &mf, one) &&
4299                             diff_filespec_is_binary(o->repo, one)) ||
4300                            (!fill_mmfile(o->repo, &mf, two) &&
4301                             diff_filespec_is_binary(o->repo, two)))
4302                                abbrev = hexsz;
4303                }
4304                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4305                            diff_abbrev_oid(&one->oid, abbrev),
4306                            diff_abbrev_oid(&two->oid, abbrev));
4307                if (one->mode == two->mode)
4308                        strbuf_addf(msg, " %06o", one->mode);
4309                strbuf_addf(msg, "%s\n", reset);
4310        }
4311}
4312
4313static void run_diff_cmd(const char *pgm,
4314                         const char *name,
4315                         const char *other,
4316                         const char *attr_path,
4317                         struct diff_filespec *one,
4318                         struct diff_filespec *two,
4319                         struct strbuf *msg,
4320                         struct diff_options *o,
4321                         struct diff_filepair *p)
4322{
4323        const char *xfrm_msg = NULL;
4324        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4325        int must_show_header = 0;
4326
4327
4328        if (o->flags.allow_external) {
4329                struct userdiff_driver *drv;
4330
4331                drv = userdiff_find_by_path(o->repo->index, attr_path);
4332                if (drv && drv->external)
4333                        pgm = drv->external;
4334        }
4335
4336        if (msg) {
4337                /*
4338                 * don't use colors when the header is intended for an
4339                 * external diff driver
4340                 */
4341                fill_metainfo(msg, name, other, one, two, o, p,
4342                              &must_show_header,
4343                              want_color(o->use_color) && !pgm);
4344                xfrm_msg = msg->len ? msg->buf : NULL;
4345        }
4346
4347        if (pgm) {
4348                run_external_diff(pgm, name, other, one, two, xfrm_msg, o);
4349                return;
4350        }
4351        if (one && two)
4352                builtin_diff(name, other ? other : name,
4353                             one, two, xfrm_msg, must_show_header,
4354                             o, complete_rewrite);
4355        else
4356                fprintf(o->file, "* Unmerged path %s\n", name);
4357}
4358
4359static void diff_fill_oid_info(struct diff_filespec *one, struct index_state *istate)
4360{
4361        if (DIFF_FILE_VALID(one)) {
4362                if (!one->oid_valid) {
4363                        struct stat st;
4364                        if (one->is_stdin) {
4365                                oidclr(&one->oid);
4366                                return;
4367                        }
4368                        if (lstat(one->path, &st) < 0)
4369                                die_errno("stat '%s'", one->path);
4370                        if (index_path(istate, &one->oid, one->path, &st, 0))
4371                                die("cannot hash %s", one->path);
4372                }
4373        }
4374        else
4375                oidclr(&one->oid);
4376}
4377
4378static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4379{
4380        /* Strip the prefix but do not molest /dev/null and absolute paths */
4381        if (*namep && !is_absolute_path(*namep)) {
4382                *namep += prefix_length;
4383                if (**namep == '/')
4384                        ++*namep;
4385        }
4386        if (*otherp && !is_absolute_path(*otherp)) {
4387                *otherp += prefix_length;
4388                if (**otherp == '/')
4389                        ++*otherp;
4390        }
4391}
4392
4393static void run_diff(struct diff_filepair *p, struct diff_options *o)
4394{
4395        const char *pgm = external_diff();
4396        struct strbuf msg;
4397        struct diff_filespec *one = p->one;
4398        struct diff_filespec *two = p->two;
4399        const char *name;
4400        const char *other;
4401        const char *attr_path;
4402
4403        name  = one->path;
4404        other = (strcmp(name, two->path) ? two->path : NULL);
4405        attr_path = name;
4406        if (o->prefix_length)
4407                strip_prefix(o->prefix_length, &name, &other);
4408
4409        if (!o->flags.allow_external)
4410                pgm = NULL;
4411
4412        if (DIFF_PAIR_UNMERGED(p)) {
4413                run_diff_cmd(pgm, name, NULL, attr_path,
4414                             NULL, NULL, NULL, o, p);
4415                return;
4416        }
4417
4418        diff_fill_oid_info(one, o->repo->index);
4419        diff_fill_oid_info(two, o->repo->index);
4420
4421        if (!pgm &&
4422            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4423            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4424                /*
4425                 * a filepair that changes between file and symlink
4426                 * needs to be split into deletion and creation.
4427                 */
4428                struct diff_filespec *null = alloc_filespec(two->path);
4429                run_diff_cmd(NULL, name, other, attr_path,
4430                             one, null, &msg,
4431                             o, p);
4432                free(null);
4433                strbuf_release(&msg);
4434
4435                null = alloc_filespec(one->path);
4436                run_diff_cmd(NULL, name, other, attr_path,
4437                             null, two, &msg, o, p);
4438                free(null);
4439        }
4440        else
4441                run_diff_cmd(pgm, name, other, attr_path,
4442                             one, two, &msg, o, p);
4443
4444        strbuf_release(&msg);
4445}
4446
4447static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4448                         struct diffstat_t *diffstat)
4449{
4450        const char *name;
4451        const char *other;
4452
4453        if (DIFF_PAIR_UNMERGED(p)) {
4454                /* unmerged */
4455                builtin_diffstat(p->one->path, NULL, NULL, NULL,
4456                                 diffstat, o, p);
4457                return;
4458        }
4459
4460        name = p->one->path;
4461        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4462
4463        if (o->prefix_length)
4464                strip_prefix(o->prefix_length, &name, &other);
4465
4466        diff_fill_oid_info(p->one, o->repo->index);
4467        diff_fill_oid_info(p->two, o->repo->index);
4468
4469        builtin_diffstat(name, other, p->one, p->two,
4470                         diffstat, o, p);
4471}
4472
4473static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4474{
4475        const char *name;
4476        const char *other;
4477        const char *attr_path;
4478
4479        if (DIFF_PAIR_UNMERGED(p)) {
4480                /* unmerged */
4481                return;
4482        }
4483
4484        name = p->one->path;
4485        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4486        attr_path = other ? other : name;
4487
4488        if (o->prefix_length)
4489                strip_prefix(o->prefix_length, &name, &other);
4490
4491        diff_fill_oid_info(p->one, o->repo->index);
4492        diff_fill_oid_info(p->two, o->repo->index);
4493
4494        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4495}
4496
4497static void prep_parse_options(struct diff_options *options);
4498
4499void repo_diff_setup(struct repository *r, struct diff_options *options)
4500{
4501        memcpy(options, &default_diff_options, sizeof(*options));
4502
4503        options->file = stdout;
4504        options->repo = r;
4505
4506        options->output_indicators[OUTPUT_INDICATOR_NEW] = '+';
4507        options->output_indicators[OUTPUT_INDICATOR_OLD] = '-';
4508        options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = ' ';
4509        options->abbrev = DEFAULT_ABBREV;
4510        options->line_termination = '\n';
4511        options->break_opt = -1;
4512        options->rename_limit = -1;
4513        options->dirstat_permille = diff_dirstat_permille_default;
4514        options->context = diff_context_default;
4515        options->interhunkcontext = diff_interhunk_context_default;
4516        options->ws_error_highlight = ws_error_highlight_default;
4517        options->flags.rename_empty = 1;
4518        options->objfind = NULL;
4519
4520        /* pathchange left =NULL by default */
4521        options->change = diff_change;
4522        options->add_remove = diff_addremove;
4523        options->use_color = diff_use_color_default;
4524        options->detect_rename = diff_detect_rename_default;
4525        options->xdl_opts |= diff_algorithm;
4526        if (diff_indent_heuristic)
4527                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4528
4529        options->orderfile = diff_order_file_cfg;
4530
4531        if (diff_no_prefix) {
4532                options->a_prefix = options->b_prefix = "";
4533        } else if (!diff_mnemonic_prefix) {
4534                options->a_prefix = "a/";
4535                options->b_prefix = "b/";
4536        }
4537
4538        options->color_moved = diff_color_moved_default;
4539        options->color_moved_ws_handling = diff_color_moved_ws_default;
4540
4541        prep_parse_options(options);
4542}
4543
4544void diff_setup_done(struct diff_options *options)
4545{
4546        unsigned check_mask = DIFF_FORMAT_NAME |
4547                              DIFF_FORMAT_NAME_STATUS |
4548                              DIFF_FORMAT_CHECKDIFF |
4549                              DIFF_FORMAT_NO_OUTPUT;
4550        /*
4551         * This must be signed because we're comparing against a potentially
4552         * negative value.
4553         */
4554        const int hexsz = the_hash_algo->hexsz;
4555
4556        if (options->set_default)
4557                options->set_default(options);
4558
4559        if (HAS_MULTI_BITS(options->output_format & check_mask))
4560                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4561
4562        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4563                die(_("-G, -S and --find-object are mutually exclusive"));
4564
4565        /*
4566         * Most of the time we can say "there are changes"
4567         * only by checking if there are changed paths, but
4568         * --ignore-whitespace* options force us to look
4569         * inside contents.
4570         */
4571
4572        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4573                options->flags.diff_from_contents = 1;
4574        else
4575                options->flags.diff_from_contents = 0;
4576
4577        if (options->flags.find_copies_harder)
4578                options->detect_rename = DIFF_DETECT_COPY;
4579
4580        if (!options->flags.relative_name)
4581                options->prefix = NULL;
4582        if (options->prefix)
4583                options->prefix_length = strlen(options->prefix);
4584        else
4585                options->prefix_length = 0;
4586
4587        if (options->output_format & (DIFF_FORMAT_NAME |
4588                                      DIFF_FORMAT_NAME_STATUS |
4589                                      DIFF_FORMAT_CHECKDIFF |
4590                                      DIFF_FORMAT_NO_OUTPUT))
4591                options->output_format &= ~(DIFF_FORMAT_RAW |
4592                                            DIFF_FORMAT_NUMSTAT |
4593                                            DIFF_FORMAT_DIFFSTAT |
4594                                            DIFF_FORMAT_SHORTSTAT |
4595                                            DIFF_FORMAT_DIRSTAT |
4596                                            DIFF_FORMAT_SUMMARY |
4597                                            DIFF_FORMAT_PATCH);
4598
4599        /*
4600         * These cases always need recursive; we do not drop caller-supplied
4601         * recursive bits for other formats here.
4602         */
4603        if (options->output_format & (DIFF_FORMAT_PATCH |
4604                                      DIFF_FORMAT_NUMSTAT |
4605                                      DIFF_FORMAT_DIFFSTAT |
4606                                      DIFF_FORMAT_SHORTSTAT |
4607                                      DIFF_FORMAT_DIRSTAT |
4608                                      DIFF_FORMAT_SUMMARY |
4609                                      DIFF_FORMAT_CHECKDIFF))
4610                options->flags.recursive = 1;
4611        /*
4612         * Also pickaxe would not work very well if you do not say recursive
4613         */
4614        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4615                options->flags.recursive = 1;
4616        /*
4617         * When patches are generated, submodules diffed against the work tree
4618         * must be checked for dirtiness too so it can be shown in the output
4619         */
4620        if (options->output_format & DIFF_FORMAT_PATCH)
4621                options->flags.dirty_submodules = 1;
4622
4623        if (options->detect_rename && options->rename_limit < 0)
4624                options->rename_limit = diff_rename_limit_default;
4625        if (hexsz < options->abbrev)
4626                options->abbrev = hexsz; /* full */
4627
4628        /*
4629         * It does not make sense to show the first hit we happened
4630         * to have found.  It does not make sense not to return with
4631         * exit code in such a case either.
4632         */
4633        if (options->flags.quick) {
4634                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4635                options->flags.exit_with_status = 1;
4636        }
4637
4638        options->diff_path_counter = 0;
4639
4640        if (options->flags.follow_renames && options->pathspec.nr != 1)
4641                die(_("--follow requires exactly one pathspec"));
4642
4643        if (!options->use_color || external_diff())
4644                options->color_moved = 0;
4645
4646        FREE_AND_NULL(options->parseopts);
4647}
4648
4649int parse_long_opt(const char *opt, const char **argv,
4650                   const char **optarg)
4651{
4652        const char *arg = argv[0];
4653        if (!skip_prefix(arg, "--", &arg))
4654                return 0;
4655        if (!skip_prefix(arg, opt, &arg))
4656                return 0;
4657        if (*arg == '=') { /* stuck form: --option=value */
4658                *optarg = arg + 1;
4659                return 1;
4660        }
4661        if (*arg != '\0')
4662                return 0;
4663        /* separate form: --option value */
4664        if (!argv[1])
4665                die("Option '--%s' requires a value", opt);
4666        *optarg = argv[1];
4667        return 2;
4668}
4669
4670static int diff_opt_stat(const struct option *opt, const char *value, int unset)
4671{
4672        struct diff_options *options = opt->value;
4673        int width = options->stat_width;
4674        int name_width = options->stat_name_width;
4675        int graph_width = options->stat_graph_width;
4676        int count = options->stat_count;
4677        char *end;
4678
4679        BUG_ON_OPT_NEG(unset);
4680
4681        if (!strcmp(opt->long_name, "stat")) {
4682                if (value) {
4683                        width = strtoul(value, &end, 10);
4684                        if (*end == ',')
4685                                name_width = strtoul(end+1, &end, 10);
4686                        if (*end == ',')
4687                                count = strtoul(end+1, &end, 10);
4688                        if (*end)
4689                                return error(_("invalid --stat value: %s"), value);
4690                }
4691        } else if (!strcmp(opt->long_name, "stat-width")) {
4692                width = strtoul(value, &end, 10);
4693                if (*end)
4694                        return error(_("%s expects a numerical value"),
4695                                     opt->long_name);
4696        } else if (!strcmp(opt->long_name, "stat-name-width")) {
4697                name_width = strtoul(value, &end, 10);
4698                if (*end)
4699                        return error(_("%s expects a numerical value"),
4700                                     opt->long_name);
4701        } else if (!strcmp(opt->long_name, "stat-graph-width")) {
4702                graph_width = strtoul(value, &end, 10);
4703                if (*end)
4704                        return error(_("%s expects a numerical value"),
4705                                     opt->long_name);
4706        } else if (!strcmp(opt->long_name, "stat-count")) {
4707                count = strtoul(value, &end, 10);
4708                if (*end)
4709                        return error(_("%s expects a numerical value"),
4710                                     opt->long_name);
4711        } else
4712                BUG("%s should not get here", opt->long_name);
4713
4714        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4715        options->stat_name_width = name_width;
4716        options->stat_graph_width = graph_width;
4717        options->stat_width = width;
4718        options->stat_count = count;
4719        return 0;
4720}
4721
4722static int parse_dirstat_opt(struct diff_options *options, const char *params)
4723{
4724        struct strbuf errmsg = STRBUF_INIT;
4725        if (parse_dirstat_params(options, params, &errmsg))
4726                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4727                    errmsg.buf);
4728        strbuf_release(&errmsg);
4729        /*
4730         * The caller knows a dirstat-related option is given from the command
4731         * line; allow it to say "return this_function();"
4732         */
4733        options->output_format |= DIFF_FORMAT_DIRSTAT;
4734        return 1;
4735}
4736
4737static const char diff_status_letters[] = {
4738        DIFF_STATUS_ADDED,
4739        DIFF_STATUS_COPIED,
4740        DIFF_STATUS_DELETED,
4741        DIFF_STATUS_MODIFIED,
4742        DIFF_STATUS_RENAMED,
4743        DIFF_STATUS_TYPE_CHANGED,
4744        DIFF_STATUS_UNKNOWN,
4745        DIFF_STATUS_UNMERGED,
4746        DIFF_STATUS_FILTER_AON,
4747        DIFF_STATUS_FILTER_BROKEN,
4748        '\0',
4749};
4750
4751static unsigned int filter_bit['Z' + 1];
4752
4753static void prepare_filter_bits(void)
4754{
4755        int i;
4756
4757        if (!filter_bit[DIFF_STATUS_ADDED]) {
4758                for (i = 0; diff_status_letters[i]; i++)
4759                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4760        }
4761}
4762
4763static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4764{
4765        return opt->filter & filter_bit[(int) status];
4766}
4767
4768unsigned diff_filter_bit(char status)
4769{
4770        prepare_filter_bits();
4771        return filter_bit[(int) status];
4772}
4773
4774static int diff_opt_diff_filter(const struct option *option,
4775                                const char *optarg, int unset)
4776{
4777        struct diff_options *opt = option->value;
4778        int i, optch;
4779
4780        BUG_ON_OPT_NEG(unset);
4781        prepare_filter_bits();
4782
4783        /*
4784         * If there is a negation e.g. 'd' in the input, and we haven't
4785         * initialized the filter field with another --diff-filter, start
4786         * from full set of bits, except for AON.
4787         */
4788        if (!opt->filter) {
4789                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4790                        if (optch < 'a' || 'z' < optch)
4791                                continue;
4792                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4793                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4794                        break;
4795                }
4796        }
4797
4798        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4799                unsigned int bit;
4800                int negate;
4801
4802                if ('a' <= optch && optch <= 'z') {
4803                        negate = 1;
4804                        optch = toupper(optch);
4805                } else {
4806                        negate = 0;
4807                }
4808
4809                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4810                if (!bit)
4811                        return error(_("unknown change class '%c' in --diff-filter=%s"),
4812                                     optarg[i], optarg);
4813                if (negate)
4814                        opt->filter &= ~bit;
4815                else
4816                        opt->filter |= bit;
4817        }
4818        return 0;
4819}
4820
4821static void enable_patch_output(int *fmt)
4822{
4823        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4824        *fmt |= DIFF_FORMAT_PATCH;
4825}
4826
4827static int diff_opt_ws_error_highlight(const struct option *option,
4828                                       const char *arg, int unset)
4829{
4830        struct diff_options *opt = option->value;
4831        int val = parse_ws_error_highlight(arg);
4832
4833        BUG_ON_OPT_NEG(unset);
4834        if (val < 0)
4835                return error(_("unknown value after ws-error-highlight=%.*s"),
4836                             -1 - val, arg);
4837        opt->ws_error_highlight = val;
4838        return 0;
4839}
4840
4841static int diff_opt_find_object(const struct option *option,
4842                                const char *arg, int unset)
4843{
4844        struct diff_options *opt = option->value;
4845        struct object_id oid;
4846
4847        BUG_ON_OPT_NEG(unset);
4848        if (get_oid(arg, &oid))
4849                return error(_("unable to resolve '%s'"), arg);
4850
4851        if (!opt->objfind)
4852                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4853
4854        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4855        opt->flags.recursive = 1;
4856        opt->flags.tree_in_recursive = 1;
4857        oidset_insert(opt->objfind, &oid);
4858        return 0;
4859}
4860
4861static int diff_opt_anchored(const struct option *opt,
4862                             const char *arg, int unset)
4863{
4864        struct diff_options *options = opt->value;
4865
4866        BUG_ON_OPT_NEG(unset);
4867        options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4868        ALLOC_GROW(options->anchors, options->anchors_nr + 1,
4869                   options->anchors_alloc);
4870        options->anchors[options->anchors_nr++] = xstrdup(arg);
4871        return 0;
4872}
4873
4874static int diff_opt_binary(const struct option *opt,
4875                           const char *arg, int unset)
4876{
4877        struct diff_options *options = opt->value;
4878
4879        BUG_ON_OPT_NEG(unset);
4880        BUG_ON_OPT_ARG(arg);
4881        enable_patch_output(&options->output_format);
4882        options->flags.binary = 1;
4883        return 0;
4884}
4885
4886static int diff_opt_break_rewrites(const struct option *opt,
4887                                   const char *arg, int unset)
4888{
4889        int *break_opt = opt->value;
4890        int opt1, opt2;
4891
4892        BUG_ON_OPT_NEG(unset);
4893        if (!arg)
4894                arg = "";
4895        opt1 = parse_rename_score(&arg);
4896        if (*arg == 0)
4897                opt2 = 0;
4898        else if (*arg != '/')
4899                return error(_("%s expects <n>/<m> form"), opt->long_name);
4900        else {
4901                arg++;
4902                opt2 = parse_rename_score(&arg);
4903        }
4904        if (*arg != 0)
4905                return error(_("%s expects <n>/<m> form"), opt->long_name);
4906        *break_opt = opt1 | (opt2 << 16);
4907        return 0;
4908}
4909
4910static int diff_opt_char(const struct option *opt,
4911                         const char *arg, int unset)
4912{
4913        char *value = opt->value;
4914
4915        BUG_ON_OPT_NEG(unset);
4916        if (arg[1])
4917                return error(_("%s expects a character, got '%s'"),
4918                             opt->long_name, arg);
4919        *value = arg[0];
4920        return 0;
4921}
4922
4923static int diff_opt_color_moved(const struct option *opt,
4924                                const char *arg, int unset)
4925{
4926        struct diff_options *options = opt->value;
4927
4928        if (unset) {
4929                options->color_moved = COLOR_MOVED_NO;
4930        } else if (!arg) {
4931                if (diff_color_moved_default)
4932                        options->color_moved = diff_color_moved_default;
4933                if (options->color_moved == COLOR_MOVED_NO)
4934                        options->color_moved = COLOR_MOVED_DEFAULT;
4935        } else {
4936                int cm = parse_color_moved(arg);
4937                if (cm < 0)
4938                        return error(_("bad --color-moved argument: %s"), arg);
4939                options->color_moved = cm;
4940        }
4941        return 0;
4942}
4943
4944static int diff_opt_color_moved_ws(const struct option *opt,
4945                                   const char *arg, int unset)
4946{
4947        struct diff_options *options = opt->value;
4948        unsigned cm;
4949
4950        if (unset) {
4951                options->color_moved_ws_handling = 0;
4952                return 0;
4953        }
4954
4955        cm = parse_color_moved_ws(arg);
4956        if (cm & COLOR_MOVED_WS_ERROR)
4957                return error(_("invalid mode '%s' in --color-moved-ws"), arg);
4958        options->color_moved_ws_handling = cm;
4959        return 0;
4960}
4961
4962static int diff_opt_color_words(const struct option *opt,
4963                                const char *arg, int unset)
4964{
4965        struct diff_options *options = opt->value;
4966
4967        BUG_ON_OPT_NEG(unset);
4968        options->use_color = 1;
4969        options->word_diff = DIFF_WORDS_COLOR;
4970        options->word_regex = arg;
4971        return 0;
4972}
4973
4974static int diff_opt_compact_summary(const struct option *opt,
4975                                    const char *arg, int unset)
4976{
4977        struct diff_options *options = opt->value;
4978
4979        BUG_ON_OPT_ARG(arg);
4980        if (unset) {
4981                options->flags.stat_with_summary = 0;
4982        } else {
4983                options->flags.stat_with_summary = 1;
4984                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4985        }
4986        return 0;
4987}
4988
4989static int diff_opt_diff_algorithm(const struct option *opt,
4990                                   const char *arg, int unset)
4991{
4992        struct diff_options *options = opt->value;
4993        long value = parse_algorithm_value(arg);
4994
4995        BUG_ON_OPT_NEG(unset);
4996        if (value < 0)
4997                return error(_("option diff-algorithm accepts \"myers\", "
4998                               "\"minimal\", \"patience\" and \"histogram\""));
4999
5000        /* clear out previous settings */
5001        DIFF_XDL_CLR(options, NEED_MINIMAL);
5002        options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
5003        options->xdl_opts |= value;
5004        return 0;
5005}
5006
5007static int diff_opt_dirstat(const struct option *opt,
5008                            const char *arg, int unset)
5009{
5010        struct diff_options *options = opt->value;
5011
5012        BUG_ON_OPT_NEG(unset);
5013        if (!strcmp(opt->long_name, "cumulative")) {
5014                if (arg)
5015                        BUG("how come --cumulative take a value?");
5016                arg = "cumulative";
5017        } else if (!strcmp(opt->long_name, "dirstat-by-file"))
5018                parse_dirstat_opt(options, "files");
5019        parse_dirstat_opt(options, arg ? arg : "");
5020        return 0;
5021}
5022
5023static int diff_opt_find_copies(const struct option *opt,
5024                                const char *arg, int unset)
5025{
5026        struct diff_options *options = opt->value;
5027
5028        BUG_ON_OPT_NEG(unset);
5029        if (!arg)
5030                arg = "";
5031        options->rename_score = parse_rename_score(&arg);
5032        if (*arg != 0)
5033                return error(_("invalid argument to %s"), opt->long_name);
5034
5035        if (options->detect_rename == DIFF_DETECT_COPY)
5036                options->flags.find_copies_harder = 1;
5037        else
5038                options->detect_rename = DIFF_DETECT_COPY;
5039
5040        return 0;
5041}
5042
5043static int diff_opt_find_renames(const struct option *opt,
5044                                 const char *arg, int unset)
5045{
5046        struct diff_options *options = opt->value;
5047
5048        BUG_ON_OPT_NEG(unset);
5049        if (!arg)
5050                arg = "";
5051        options->rename_score = parse_rename_score(&arg);
5052        if (*arg != 0)
5053                return error(_("invalid argument to %s"), opt->long_name);
5054
5055        options->detect_rename = DIFF_DETECT_RENAME;
5056        return 0;
5057}
5058
5059static int diff_opt_follow(const struct option *opt,
5060                           const char *arg, int unset)
5061{
5062        struct diff_options *options = opt->value;
5063
5064        BUG_ON_OPT_ARG(arg);
5065        if (unset) {
5066                options->flags.follow_renames = 0;
5067                options->flags.default_follow_renames = 0;
5068        } else {
5069                options->flags.follow_renames = 1;
5070        }
5071        return 0;
5072}
5073
5074static int diff_opt_ignore_submodules(const struct option *opt,
5075                                      const char *arg, int unset)
5076{
5077        struct diff_options *options = opt->value;
5078
5079        BUG_ON_OPT_NEG(unset);
5080        if (!arg)
5081                arg = "all";
5082        options->flags.override_submodule_config = 1;
5083        handle_ignore_submodules_arg(options, arg);
5084        return 0;
5085}
5086
5087static int diff_opt_line_prefix(const struct option *opt,
5088                                const char *optarg, int unset)
5089{
5090        struct diff_options *options = opt->value;
5091
5092        BUG_ON_OPT_NEG(unset);
5093        options->line_prefix = optarg;
5094        options->line_prefix_length = strlen(options->line_prefix);
5095        graph_setup_line_prefix(options);
5096        return 0;
5097}
5098
5099static int diff_opt_no_prefix(const struct option *opt,
5100                              const char *optarg, int unset)
5101{
5102        struct diff_options *options = opt->value;
5103
5104        BUG_ON_OPT_NEG(unset);
5105        BUG_ON_OPT_ARG(optarg);
5106        options->a_prefix = "";
5107        options->b_prefix = "";
5108        return 0;
5109}
5110
5111static enum parse_opt_result diff_opt_output(struct parse_opt_ctx_t *ctx,
5112                                             const struct option *opt,
5113                                             const char *arg, int unset)
5114{
5115        struct diff_options *options = opt->value;
5116        char *path;
5117
5118        BUG_ON_OPT_NEG(unset);
5119        path = prefix_filename(ctx->prefix, arg);
5120        options->file = xfopen(path, "w");
5121        options->close_file = 1;
5122        if (options->use_color != GIT_COLOR_ALWAYS)
5123                options->use_color = GIT_COLOR_NEVER;
5124        free(path);
5125        return 0;
5126}
5127
5128static int diff_opt_patience(const struct option *opt,
5129                             const char *arg, int unset)
5130{
5131        struct diff_options *options = opt->value;
5132        int i;
5133
5134        BUG_ON_OPT_NEG(unset);
5135        BUG_ON_OPT_ARG(arg);
5136        options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
5137        /*
5138         * Both --patience and --anchored use PATIENCE_DIFF
5139         * internally, so remove any anchors previously
5140         * specified.
5141         */
5142        for (i = 0; i < options->anchors_nr; i++)
5143                free(options->anchors[i]);
5144        options->anchors_nr = 0;
5145        return 0;
5146}
5147
5148static int diff_opt_pickaxe_regex(const struct option *opt,
5149                                  const char *arg, int unset)
5150{
5151        struct diff_options *options = opt->value;
5152
5153        BUG_ON_OPT_NEG(unset);
5154        options->pickaxe = arg;
5155        options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
5156        return 0;
5157}
5158
5159static int diff_opt_pickaxe_string(const struct option *opt,
5160                                   const char *arg, int unset)
5161{
5162        struct diff_options *options = opt->value;
5163
5164        BUG_ON_OPT_NEG(unset);
5165        options->pickaxe = arg;
5166        options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
5167        return 0;
5168}
5169
5170static int diff_opt_relative(const struct option *opt,
5171                             const char *arg, int unset)
5172{
5173        struct diff_options *options = opt->value;
5174
5175        BUG_ON_OPT_NEG(unset);
5176        options->flags.relative_name = 1;
5177        if (arg)
5178                options->prefix = arg;
5179        return 0;
5180}
5181
5182static int diff_opt_submodule(const struct option *opt,
5183                              const char *arg, int unset)
5184{
5185        struct diff_options *options = opt->value;
5186
5187        BUG_ON_OPT_NEG(unset);
5188        if (!arg)
5189                arg = "log";
5190        if (parse_submodule_params(options, arg))
5191                return error(_("failed to parse --submodule option parameter: '%s'"),
5192                             arg);
5193        return 0;
5194}
5195
5196static int diff_opt_textconv(const struct option *opt,
5197                             const char *arg, int unset)
5198{
5199        struct diff_options *options = opt->value;
5200
5201        BUG_ON_OPT_ARG(arg);
5202        if (unset) {
5203                options->flags.allow_textconv = 0;
5204        } else {
5205                options->flags.allow_textconv = 1;
5206                options->flags.textconv_set_via_cmdline = 1;
5207        }
5208        return 0;
5209}
5210
5211static int diff_opt_unified(const struct option *opt,
5212                            const char *arg, int unset)
5213{
5214        struct diff_options *options = opt->value;
5215        char *s;
5216
5217        BUG_ON_OPT_NEG(unset);
5218
5219        if (arg) {
5220                options->context = strtol(arg, &s, 10);
5221                if (*s)
5222                        return error(_("%s expects a numerical value"), "--unified");
5223        }
5224        enable_patch_output(&options->output_format);
5225
5226        return 0;
5227}
5228
5229static int diff_opt_word_diff(const struct option *opt,
5230                              const char *arg, int unset)
5231{
5232        struct diff_options *options = opt->value;
5233
5234        BUG_ON_OPT_NEG(unset);
5235        if (arg) {
5236                if (!strcmp(arg, "plain"))
5237                        options->word_diff = DIFF_WORDS_PLAIN;
5238                else if (!strcmp(arg, "color")) {
5239                        options->use_color = 1;
5240                        options->word_diff = DIFF_WORDS_COLOR;
5241                }
5242                else if (!strcmp(arg, "porcelain"))
5243                        options->word_diff = DIFF_WORDS_PORCELAIN;
5244                else if (!strcmp(arg, "none"))
5245                        options->word_diff = DIFF_WORDS_NONE;
5246                else
5247                        return error(_("bad --word-diff argument: %s"), arg);
5248        } else {
5249                if (options->word_diff == DIFF_WORDS_NONE)
5250                        options->word_diff = DIFF_WORDS_PLAIN;
5251        }
5252        return 0;
5253}
5254
5255static int diff_opt_word_diff_regex(const struct option *opt,
5256                                    const char *arg, int unset)
5257{
5258        struct diff_options *options = opt->value;
5259
5260        BUG_ON_OPT_NEG(unset);
5261        if (options->word_diff == DIFF_WORDS_NONE)
5262                options->word_diff = DIFF_WORDS_PLAIN;
5263        options->word_regex = arg;
5264        return 0;
5265}
5266
5267static void prep_parse_options(struct diff_options *options)
5268{
5269        struct option parseopts[] = {
5270                OPT_GROUP(N_("Diff output format options")),
5271                OPT_BITOP('p', "patch", &options->output_format,
5272                          N_("generate patch"),
5273                          DIFF_FORMAT_PATCH, DIFF_FORMAT_NO_OUTPUT),
5274                OPT_BIT_F('s', "no-patch", &options->output_format,
5275                          N_("suppress diff output"),
5276                          DIFF_FORMAT_NO_OUTPUT, PARSE_OPT_NONEG),
5277                OPT_BITOP('u', NULL, &options->output_format,
5278                          N_("generate patch"),
5279                          DIFF_FORMAT_PATCH, DIFF_FORMAT_NO_OUTPUT),
5280                OPT_CALLBACK_F('U', "unified", options, N_("<n>"),
5281                               N_("generate diffs with <n> lines context"),
5282                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG, diff_opt_unified),
5283                OPT_BOOL('W', "function-context", &options->flags.funccontext,
5284                         N_("generate diffs with <n> lines context")),
5285                OPT_BIT_F(0, "raw", &options->output_format,
5286                          N_("generate the diff in raw format"),
5287                          DIFF_FORMAT_RAW, PARSE_OPT_NONEG),
5288                OPT_BITOP(0, "patch-with-raw", &options->output_format,
5289                          N_("synonym for '-p --raw'"),
5290                          DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW,
5291                          DIFF_FORMAT_NO_OUTPUT),
5292                OPT_BITOP(0, "patch-with-stat", &options->output_format,
5293                          N_("synonym for '-p --stat'"),
5294                          DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT,
5295                          DIFF_FORMAT_NO_OUTPUT),
5296                OPT_BIT_F(0, "numstat", &options->output_format,
5297                          N_("machine friendly --stat"),
5298                          DIFF_FORMAT_NUMSTAT, PARSE_OPT_NONEG),
5299                OPT_BIT_F(0, "shortstat", &options->output_format,
5300                          N_("output only the last line of --stat"),
5301                          DIFF_FORMAT_SHORTSTAT, PARSE_OPT_NONEG),
5302                OPT_CALLBACK_F('X', "dirstat", options, N_("<param1,param2>..."),
5303                               N_("output the distribution of relative amount of changes for each sub-directory"),
5304                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5305                               diff_opt_dirstat),
5306                OPT_CALLBACK_F(0, "cumulative", options, NULL,
5307                               N_("synonym for --dirstat=cumulative"),
5308                               PARSE_OPT_NONEG | PARSE_OPT_NOARG,
5309                               diff_opt_dirstat),
5310                OPT_CALLBACK_F(0, "dirstat-by-file", options, N_("<param1,param2>..."),
5311                               N_("synonym for --dirstat=files,param1,param2..."),
5312                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5313                               diff_opt_dirstat),
5314                OPT_BIT_F(0, "check", &options->output_format,
5315                          N_("warn if changes introduce conflict markers or whitespace errors"),
5316                          DIFF_FORMAT_CHECKDIFF, PARSE_OPT_NONEG),
5317                OPT_BIT_F(0, "summary", &options->output_format,
5318                          N_("condensed summary such as creations, renames and mode changes"),
5319                          DIFF_FORMAT_SUMMARY, PARSE_OPT_NONEG),
5320                OPT_BIT_F(0, "name-only", &options->output_format,
5321                          N_("show only names of changed files"),
5322                          DIFF_FORMAT_NAME, PARSE_OPT_NONEG),
5323                OPT_BIT_F(0, "name-status", &options->output_format,
5324                          N_("show only names and status of changed files"),
5325                          DIFF_FORMAT_NAME_STATUS, PARSE_OPT_NONEG),
5326                OPT_CALLBACK_F(0, "stat", options, N_("<width>[,<name-width>[,<count>]]"),
5327                               N_("generate diffstat"),
5328                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG, diff_opt_stat),
5329                OPT_CALLBACK_F(0, "stat-width", options, N_("<width>"),
5330                               N_("generate diffstat with a given width"),
5331                               PARSE_OPT_NONEG, diff_opt_stat),
5332                OPT_CALLBACK_F(0, "stat-name-width", options, N_("<width>"),
5333                               N_("generate diffstat with a given name width"),
5334                               PARSE_OPT_NONEG, diff_opt_stat),
5335                OPT_CALLBACK_F(0, "stat-graph-width", options, N_("<width>"),
5336                               N_("generate diffstat with a given graph width"),
5337                               PARSE_OPT_NONEG, diff_opt_stat),
5338                OPT_CALLBACK_F(0, "stat-count", options, N_("<count>"),
5339                               N_("generate diffstat with limited lines"),
5340                               PARSE_OPT_NONEG, diff_opt_stat),
5341                OPT_CALLBACK_F(0, "compact-summary", options, NULL,
5342                               N_("generate compact summary in diffstat"),
5343                               PARSE_OPT_NOARG, diff_opt_compact_summary),
5344                OPT_CALLBACK_F(0, "binary", options, NULL,
5345                               N_("output a binary diff that can be applied"),
5346                               PARSE_OPT_NONEG | PARSE_OPT_NOARG, diff_opt_binary),
5347                OPT_BOOL(0, "full-index", &options->flags.full_index,
5348                         N_("show full pre- and post-image object names on the \"index\" lines")),
5349                OPT_COLOR_FLAG(0, "color", &options->use_color,
5350                               N_("show colored diff")),
5351                OPT_CALLBACK_F(0, "ws-error-highlight", options, N_("<kind>"),
5352                               N_("highlight whitespace errors in the 'context', 'old' or 'new' lines in the diff"),
5353                               PARSE_OPT_NONEG, diff_opt_ws_error_highlight),
5354                OPT_SET_INT('z', NULL, &options->line_termination,
5355                            N_("do not munge pathnames and use NULs as output field terminators in --raw or --numstat"),
5356                            0),
5357                OPT__ABBREV(&options->abbrev),
5358                OPT_STRING_F(0, "src-prefix", &options->a_prefix, N_("<prefix>"),
5359                             N_("show the given source prefix instead of \"a/\""),
5360                             PARSE_OPT_NONEG),
5361                OPT_STRING_F(0, "dst-prefix", &options->b_prefix, N_("<prefix>"),
5362                             N_("show the given destination prefix instead of \"b/\""),
5363                             PARSE_OPT_NONEG),
5364                OPT_CALLBACK_F(0, "line-prefix", options, N_("<prefix>"),
5365                               N_("prepend an additional prefix to every line of output"),
5366                               PARSE_OPT_NONEG, diff_opt_line_prefix),
5367                OPT_CALLBACK_F(0, "no-prefix", options, NULL,
5368                               N_("do not show any source or destination prefix"),
5369                               PARSE_OPT_NONEG | PARSE_OPT_NOARG, diff_opt_no_prefix),
5370                OPT_INTEGER_F(0, "inter-hunk-context", &options->interhunkcontext,
5371                              N_("show context between diff hunks up to the specified number of lines"),
5372                              PARSE_OPT_NONEG),
5373                OPT_CALLBACK_F(0, "output-indicator-new",
5374                               &options->output_indicators[OUTPUT_INDICATOR_NEW],
5375                               N_("<char>"),
5376                               N_("specify the character to indicate a new line instead of '+'"),
5377                               PARSE_OPT_NONEG, diff_opt_char),
5378                OPT_CALLBACK_F(0, "output-indicator-old",
5379                               &options->output_indicators[OUTPUT_INDICATOR_OLD],
5380                               N_("<char>"),
5381                               N_("specify the character to indicate an old line instead of '-'"),
5382                               PARSE_OPT_NONEG, diff_opt_char),
5383                OPT_CALLBACK_F(0, "output-indicator-context",
5384                               &options->output_indicators[OUTPUT_INDICATOR_CONTEXT],
5385                               N_("<char>"),
5386                               N_("specify the character to indicate a context instead of ' '"),
5387                               PARSE_OPT_NONEG, diff_opt_char),
5388
5389                OPT_GROUP(N_("Diff rename options")),
5390                OPT_CALLBACK_F('B', "break-rewrites", &options->break_opt, N_("<n>[/<m>]"),
5391                               N_("break complete rewrite changes into pairs of delete and create"),
5392                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5393                               diff_opt_break_rewrites),
5394                OPT_CALLBACK_F('M', "find-renames", options, N_("<n>"),
5395                               N_("detect renames"),
5396                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5397                               diff_opt_find_renames),
5398                OPT_SET_INT_F('D', "irreversible-delete", &options->irreversible_delete,
5399                              N_("omit the preimage for deletes"),
5400                              1, PARSE_OPT_NONEG),
5401                OPT_CALLBACK_F('C', "find-copies", options, N_("<n>"),
5402                               N_("detect copies"),
5403                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5404                               diff_opt_find_copies),
5405                OPT_BOOL(0, "find-copies-harder", &options->flags.find_copies_harder,
5406                         N_("use unmodified files as source to find copies")),
5407                OPT_SET_INT_F(0, "no-renames", &options->detect_rename,
5408                              N_("disable rename detection"),
5409                              0, PARSE_OPT_NONEG),
5410                OPT_BOOL(0, "rename-empty", &options->flags.rename_empty,
5411                         N_("use empty blobs as rename source")),
5412                OPT_CALLBACK_F(0, "follow", options, NULL,
5413                               N_("continue listing the history of a file beyond renames"),
5414                               PARSE_OPT_NOARG, diff_opt_follow),
5415                OPT_INTEGER('l', NULL, &options->rename_limit,
5416                            N_("prevent rename/copy detection if the number of rename/copy targets exceeds given limit")),
5417
5418                OPT_GROUP(N_("Diff algorithm options")),
5419                OPT_BIT(0, "minimal", &options->xdl_opts,
5420                        N_("produce the smallest possible diff"),
5421                        XDF_NEED_MINIMAL),
5422                OPT_BIT_F('w', "ignore-all-space", &options->xdl_opts,
5423                          N_("ignore whitespace when comparing lines"),
5424                          XDF_IGNORE_WHITESPACE, PARSE_OPT_NONEG),
5425                OPT_BIT_F('b', "ignore-space-change", &options->xdl_opts,
5426                          N_("ignore changes in amount of whitespace"),
5427                          XDF_IGNORE_WHITESPACE_CHANGE, PARSE_OPT_NONEG),
5428                OPT_BIT_F(0, "ignore-space-at-eol", &options->xdl_opts,
5429                          N_("ignore changes in whitespace at EOL"),
5430                          XDF_IGNORE_WHITESPACE_AT_EOL, PARSE_OPT_NONEG),
5431                OPT_BIT_F(0, "ignore-cr-at-eol", &options->xdl_opts,
5432                          N_("ignore carrier-return at the end of line"),
5433                          XDF_IGNORE_CR_AT_EOL, PARSE_OPT_NONEG),
5434                OPT_BIT_F(0, "ignore-blank-lines", &options->xdl_opts,
5435                          N_("ignore changes whose lines are all blank"),
5436                          XDF_IGNORE_BLANK_LINES, PARSE_OPT_NONEG),
5437                OPT_BIT(0, "indent-heuristic", &options->xdl_opts,
5438                        N_("heuristic to shift diff hunk boundaries for easy reading"),
5439                        XDF_INDENT_HEURISTIC),
5440                OPT_CALLBACK_F(0, "patience", options, NULL,
5441                               N_("generate diff using the \"patience diff\" algorithm"),
5442                               PARSE_OPT_NONEG | PARSE_OPT_NOARG,
5443                               diff_opt_patience),
5444                OPT_BITOP(0, "histogram", &options->xdl_opts,
5445                          N_("generate diff using the \"histogram diff\" algorithm"),
5446                          XDF_HISTOGRAM_DIFF, XDF_DIFF_ALGORITHM_MASK),
5447                OPT_CALLBACK_F(0, "diff-algorithm", options, N_("<algorithm>"),
5448                               N_("choose a diff algorithm"),
5449                               PARSE_OPT_NONEG, diff_opt_diff_algorithm),
5450                OPT_CALLBACK_F(0, "anchored", options, N_("<text>"),
5451                               N_("generate diff using the \"anchored diff\" algorithm"),
5452                               PARSE_OPT_NONEG, diff_opt_anchored),
5453                OPT_CALLBACK_F(0, "word-diff", options, N_("<mode>"),
5454                               N_("show word diff, using <mode> to delimit changed words"),
5455                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG, diff_opt_word_diff),
5456                OPT_CALLBACK_F(0, "word-diff-regex", options, N_("<regex>"),
5457                               N_("use <regex> to decide what a word is"),
5458                               PARSE_OPT_NONEG, diff_opt_word_diff_regex),
5459                OPT_CALLBACK_F(0, "color-words", options, N_("<regex>"),
5460                               N_("equivalent to --word-diff=color --word-diff-regex=<regex>"),
5461                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG, diff_opt_color_words),
5462                OPT_CALLBACK_F(0, "color-moved", options, N_("<mode>"),
5463                               N_("moved lines of code are colored differently"),
5464                               PARSE_OPT_OPTARG, diff_opt_color_moved),
5465                OPT_CALLBACK_F(0, "color-moved-ws", options, N_("<mode>"),
5466                               N_("how white spaces are ignored in --color-moved"),
5467                               0, diff_opt_color_moved_ws),
5468
5469                OPT_GROUP(N_("Other diff options")),
5470                OPT_CALLBACK_F(0, "relative", options, N_("<prefix>"),
5471                               N_("when run from subdir, exclude changes outside and show relative paths"),
5472                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5473                               diff_opt_relative),
5474                OPT_BOOL('a', "text", &options->flags.text,
5475                         N_("treat all files as text")),
5476                OPT_BOOL('R', NULL, &options->flags.reverse_diff,
5477                         N_("swap two inputs, reverse the diff")),
5478                OPT_BOOL(0, "exit-code", &options->flags.exit_with_status,
5479                         N_("exit with 1 if there were differences, 0 otherwise")),
5480                OPT_BOOL(0, "quiet", &options->flags.quick,
5481                         N_("disable all output of the program")),
5482                OPT_BOOL(0, "ext-diff", &options->flags.allow_external,
5483                         N_("allow an external diff helper to be executed")),
5484                OPT_CALLBACK_F(0, "textconv", options, NULL,
5485                               N_("run external text conversion filters when comparing binary files"),
5486                               PARSE_OPT_NOARG, diff_opt_textconv),
5487                OPT_CALLBACK_F(0, "ignore-submodules", options, N_("<when>"),
5488                               N_("ignore changes to submodules in the diff generation"),
5489                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5490                               diff_opt_ignore_submodules),
5491                OPT_CALLBACK_F(0, "submodule", options, N_("<format>"),
5492                               N_("specify how differences in submodules are shown"),
5493                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5494                               diff_opt_submodule),
5495                OPT_SET_INT_F(0, "ita-invisible-in-index", &options->ita_invisible_in_index,
5496                              N_("hide 'git add -N' entries from the index"),
5497                              1, PARSE_OPT_NONEG),
5498                OPT_SET_INT_F(0, "ita-visible-in-index", &options->ita_invisible_in_index,
5499                              N_("treat 'git add -N' entries as real in the index"),
5500                              0, PARSE_OPT_NONEG),
5501                OPT_CALLBACK_F('S', NULL, options, N_("<string>"),
5502                               N_("look for differences that change the number of occurrences of the specified string"),
5503                               0, diff_opt_pickaxe_string),
5504                OPT_CALLBACK_F('G', NULL, options, N_("<regex>"),
5505                               N_("look for differences that change the number of occurrences of the specified regex"),
5506                               0, diff_opt_pickaxe_regex),
5507                OPT_BIT_F(0, "pickaxe-all", &options->pickaxe_opts,
5508                          N_("show all changes in the changeset with -S or -G"),
5509                          DIFF_PICKAXE_ALL, PARSE_OPT_NONEG),
5510                OPT_BIT_F(0, "pickaxe-regex", &options->pickaxe_opts,
5511                          N_("treat <string> in -S as extended POSIX regular expression"),
5512                          DIFF_PICKAXE_REGEX, PARSE_OPT_NONEG),
5513                OPT_FILENAME('O', NULL, &options->orderfile,
5514                             N_("control the order in which files appear in the output")),
5515                OPT_CALLBACK_F(0, "find-object", options, N_("<object-id>"),
5516                               N_("look for differences that change the number of occurrences of the specified object"),
5517                               PARSE_OPT_NONEG, diff_opt_find_object),
5518                OPT_CALLBACK_F(0, "diff-filter", options, N_("[(A|C|D|M|R|T|U|X|B)...[*]]"),
5519                               N_("select files by diff type"),
5520                               PARSE_OPT_NONEG, diff_opt_diff_filter),
5521                { OPTION_CALLBACK, 0, "output", options, N_("<file>"),
5522                  N_("Output to a specific file"),
5523                  PARSE_OPT_NONEG, NULL, 0, diff_opt_output },
5524
5525                OPT_END()
5526        };
5527
5528        ALLOC_ARRAY(options->parseopts, ARRAY_SIZE(parseopts));
5529        memcpy(options->parseopts, parseopts, sizeof(parseopts));
5530}
5531
5532int diff_opt_parse(struct diff_options *options,
5533                   const char **av, int ac, const char *prefix)
5534{
5535        if (!prefix)
5536                prefix = "";
5537
5538        ac = parse_options(ac, av, prefix, options->parseopts, NULL,
5539                           PARSE_OPT_KEEP_DASHDASH |
5540                           PARSE_OPT_KEEP_UNKNOWN |
5541                           PARSE_OPT_NO_INTERNAL_HELP |
5542                           PARSE_OPT_ONE_SHOT |
5543                           PARSE_OPT_STOP_AT_NON_OPTION);
5544
5545        return ac;
5546}
5547
5548int parse_rename_score(const char **cp_p)
5549{
5550        unsigned long num, scale;
5551        int ch, dot;
5552        const char *cp = *cp_p;
5553
5554        num = 0;
5555        scale = 1;
5556        dot = 0;
5557        for (;;) {
5558                ch = *cp;
5559                if ( !dot && ch == '.' ) {
5560                        scale = 1;
5561                        dot = 1;
5562                } else if ( ch == '%' ) {
5563                        scale = dot ? scale*100 : 100;
5564                        cp++;   /* % is always at the end */
5565                        break;
5566                } else if ( ch >= '0' && ch <= '9' ) {
5567                        if ( scale < 100000 ) {
5568                                scale *= 10;
5569                                num = (num*10) + (ch-'0');
5570                        }
5571                } else {
5572                        break;
5573                }
5574                cp++;
5575        }
5576        *cp_p = cp;
5577
5578        /* user says num divided by scale and we say internally that
5579         * is MAX_SCORE * num / scale.
5580         */
5581        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5582}
5583
5584struct diff_queue_struct diff_queued_diff;
5585
5586void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5587{
5588        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5589        queue->queue[queue->nr++] = dp;
5590}
5591
5592struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5593                                 struct diff_filespec *one,
5594                                 struct diff_filespec *two)
5595{
5596        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5597        dp->one = one;
5598        dp->two = two;
5599        if (queue)
5600                diff_q(queue, dp);
5601        return dp;
5602}
5603
5604void diff_free_filepair(struct diff_filepair *p)
5605{
5606        free_filespec(p->one);
5607        free_filespec(p->two);
5608        free(p);
5609}
5610
5611const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5612{
5613        int abblen;
5614        const char *abbrev;
5615
5616        /* Do we want all 40 hex characters? */
5617        if (len == the_hash_algo->hexsz)
5618                return oid_to_hex(oid);
5619
5620        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5621        abbrev = diff_abbrev_oid(oid, len);
5622
5623        if (!print_sha1_ellipsis())
5624                return abbrev;
5625
5626        abblen = strlen(abbrev);
5627
5628        /*
5629         * In well-behaved cases, where the abbreviated result is the
5630         * same as the requested length, append three dots after the
5631         * abbreviation (hence the whole logic is limited to the case
5632         * where abblen < 37); when the actual abbreviated result is a
5633         * bit longer than the requested length, we reduce the number
5634         * of dots so that they match the well-behaved ones.  However,
5635         * if the actual abbreviation is longer than the requested
5636         * length by more than three, we give up on aligning, and add
5637         * three dots anyway, to indicate that the output is not the
5638         * full object name.  Yes, this may be suboptimal, but this
5639         * appears only in "diff --raw --abbrev" output and it is not
5640         * worth the effort to change it now.  Note that this would
5641         * likely to work fine when the automatic sizing of default
5642         * abbreviation length is used--we would be fed -1 in "len" in
5643         * that case, and will end up always appending three-dots, but
5644         * the automatic sizing is supposed to give abblen that ensures
5645         * uniqueness across all objects (statistically speaking).
5646         */
5647        if (abblen < the_hash_algo->hexsz - 3) {
5648                static char hex[GIT_MAX_HEXSZ + 1];
5649                if (len < abblen && abblen <= len + 2)
5650                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5651                else
5652                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5653                return hex;
5654        }
5655
5656        return oid_to_hex(oid);
5657}
5658
5659static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5660{
5661        int line_termination = opt->line_termination;
5662        int inter_name_termination = line_termination ? '\t' : '\0';
5663
5664        fprintf(opt->file, "%s", diff_line_prefix(opt));
5665        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5666                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5667                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5668                fprintf(opt->file, "%s ",
5669                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5670        }
5671        if (p->score) {
5672                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5673                        inter_name_termination);
5674        } else {
5675                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5676        }
5677
5678        if (p->status == DIFF_STATUS_COPIED ||
5679            p->status == DIFF_STATUS_RENAMED) {
5680                const char *name_a, *name_b;
5681                name_a = p->one->path;
5682                name_b = p->two->path;
5683                strip_prefix(opt->prefix_length, &name_a, &name_b);
5684                write_name_quoted(name_a, opt->file, inter_name_termination);
5685                write_name_quoted(name_b, opt->file, line_termination);
5686        } else {
5687                const char *name_a, *name_b;
5688                name_a = p->one->mode ? p->one->path : p->two->path;
5689                name_b = NULL;
5690                strip_prefix(opt->prefix_length, &name_a, &name_b);
5691                write_name_quoted(name_a, opt->file, line_termination);
5692        }
5693}
5694
5695int diff_unmodified_pair(struct diff_filepair *p)
5696{
5697        /* This function is written stricter than necessary to support
5698         * the currently implemented transformers, but the idea is to
5699         * let transformers to produce diff_filepairs any way they want,
5700         * and filter and clean them up here before producing the output.
5701         */
5702        struct diff_filespec *one = p->one, *two = p->two;
5703
5704        if (DIFF_PAIR_UNMERGED(p))
5705                return 0; /* unmerged is interesting */
5706
5707        /* deletion, addition, mode or type change
5708         * and rename are all interesting.
5709         */
5710        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5711            DIFF_PAIR_MODE_CHANGED(p) ||
5712            strcmp(one->path, two->path))
5713                return 0;
5714
5715        /* both are valid and point at the same path.  that is, we are
5716         * dealing with a change.
5717         */
5718        if (one->oid_valid && two->oid_valid &&
5719            oideq(&one->oid, &two->oid) &&
5720            !one->dirty_submodule && !two->dirty_submodule)
5721                return 1; /* no change */
5722        if (!one->oid_valid && !two->oid_valid)
5723                return 1; /* both look at the same file on the filesystem. */
5724        return 0;
5725}
5726
5727static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5728{
5729        if (diff_unmodified_pair(p))
5730                return;
5731
5732        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5733            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5734                return; /* no tree diffs in patch format */
5735
5736        run_diff(p, o);
5737}
5738
5739static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5740                            struct diffstat_t *diffstat)
5741{
5742        if (diff_unmodified_pair(p))
5743                return;
5744
5745        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5746            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5747                return; /* no useful stat for tree diffs */
5748
5749        run_diffstat(p, o, diffstat);
5750}
5751
5752static void diff_flush_checkdiff(struct diff_filepair *p,
5753                struct diff_options *o)
5754{
5755        if (diff_unmodified_pair(p))
5756                return;
5757
5758        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5759            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5760                return; /* nothing to check in tree diffs */
5761
5762        run_checkdiff(p, o);
5763}
5764
5765int diff_queue_is_empty(void)
5766{
5767        struct diff_queue_struct *q = &diff_queued_diff;
5768        int i;
5769        for (i = 0; i < q->nr; i++)
5770                if (!diff_unmodified_pair(q->queue[i]))
5771                        return 0;
5772        return 1;
5773}
5774
5775#if DIFF_DEBUG
5776void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5777{
5778        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5779                x, one ? one : "",
5780                s->path,
5781                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5782                s->mode,
5783                s->oid_valid ? oid_to_hex(&s->oid) : "");
5784        fprintf(stderr, "queue[%d] %s size %lu\n",
5785                x, one ? one : "",
5786                s->size);
5787}
5788
5789void diff_debug_filepair(const struct diff_filepair *p, int i)
5790{
5791        diff_debug_filespec(p->one, i, "one");
5792        diff_debug_filespec(p->two, i, "two");
5793        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5794                p->score, p->status ? p->status : '?',
5795                p->one->rename_used, p->broken_pair);
5796}
5797
5798void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5799{
5800        int i;
5801        if (msg)
5802                fprintf(stderr, "%s\n", msg);
5803        fprintf(stderr, "q->nr = %d\n", q->nr);
5804        for (i = 0; i < q->nr; i++) {
5805                struct diff_filepair *p = q->queue[i];
5806                diff_debug_filepair(p, i);
5807        }
5808}
5809#endif
5810
5811static void diff_resolve_rename_copy(void)
5812{
5813        int i;
5814        struct diff_filepair *p;
5815        struct diff_queue_struct *q = &diff_queued_diff;
5816
5817        diff_debug_queue("resolve-rename-copy", q);
5818
5819        for (i = 0; i < q->nr; i++) {
5820                p = q->queue[i];
5821                p->status = 0; /* undecided */
5822                if (DIFF_PAIR_UNMERGED(p))
5823                        p->status = DIFF_STATUS_UNMERGED;
5824                else if (!DIFF_FILE_VALID(p->one))
5825                        p->status = DIFF_STATUS_ADDED;
5826                else if (!DIFF_FILE_VALID(p->two))
5827                        p->status = DIFF_STATUS_DELETED;
5828                else if (DIFF_PAIR_TYPE_CHANGED(p))
5829                        p->status = DIFF_STATUS_TYPE_CHANGED;
5830
5831                /* from this point on, we are dealing with a pair
5832                 * whose both sides are valid and of the same type, i.e.
5833                 * either in-place edit or rename/copy edit.
5834                 */
5835                else if (DIFF_PAIR_RENAME(p)) {
5836                        /*
5837                         * A rename might have re-connected a broken
5838                         * pair up, causing the pathnames to be the
5839                         * same again. If so, that's not a rename at
5840                         * all, just a modification..
5841                         *
5842                         * Otherwise, see if this source was used for
5843                         * multiple renames, in which case we decrement
5844                         * the count, and call it a copy.
5845                         */
5846                        if (!strcmp(p->one->path, p->two->path))
5847                                p->status = DIFF_STATUS_MODIFIED;
5848                        else if (--p->one->rename_used > 0)
5849                                p->status = DIFF_STATUS_COPIED;
5850                        else
5851                                p->status = DIFF_STATUS_RENAMED;
5852                }
5853                else if (!oideq(&p->one->oid, &p->two->oid) ||
5854                         p->one->mode != p->two->mode ||
5855                         p->one->dirty_submodule ||
5856                         p->two->dirty_submodule ||
5857                         is_null_oid(&p->one->oid))
5858                        p->status = DIFF_STATUS_MODIFIED;
5859                else {
5860                        /* This is a "no-change" entry and should not
5861                         * happen anymore, but prepare for broken callers.
5862                         */
5863                        error("feeding unmodified %s to diffcore",
5864                              p->one->path);
5865                        p->status = DIFF_STATUS_UNKNOWN;
5866                }
5867        }
5868        diff_debug_queue("resolve-rename-copy done", q);
5869}
5870
5871static int check_pair_status(struct diff_filepair *p)
5872{
5873        switch (p->status) {
5874        case DIFF_STATUS_UNKNOWN:
5875                return 0;
5876        case 0:
5877                die("internal error in diff-resolve-rename-copy");
5878        default:
5879                return 1;
5880        }
5881}
5882
5883static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5884{
5885        int fmt = opt->output_format;
5886
5887        if (fmt & DIFF_FORMAT_CHECKDIFF)
5888                diff_flush_checkdiff(p, opt);
5889        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5890                diff_flush_raw(p, opt);
5891        else if (fmt & DIFF_FORMAT_NAME) {
5892                const char *name_a, *name_b;
5893                name_a = p->two->path;
5894                name_b = NULL;
5895                strip_prefix(opt->prefix_length, &name_a, &name_b);
5896                fprintf(opt->file, "%s", diff_line_prefix(opt));
5897                write_name_quoted(name_a, opt->file, opt->line_termination);
5898        }
5899}
5900
5901static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5902{
5903        struct strbuf sb = STRBUF_INIT;
5904        if (fs->mode)
5905                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5906        else
5907                strbuf_addf(&sb, " %s ", newdelete);
5908
5909        quote_c_style(fs->path, &sb, NULL, 0);
5910        strbuf_addch(&sb, '\n');
5911        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5912                         sb.buf, sb.len, 0);
5913        strbuf_release(&sb);
5914}
5915
5916static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5917                int show_name)
5918{
5919        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5920                struct strbuf sb = STRBUF_INIT;
5921                strbuf_addf(&sb, " mode change %06o => %06o",
5922                            p->one->mode, p->two->mode);
5923                if (show_name) {
5924                        strbuf_addch(&sb, ' ');
5925                        quote_c_style(p->two->path, &sb, NULL, 0);
5926                }
5927                strbuf_addch(&sb, '\n');
5928                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5929                                 sb.buf, sb.len, 0);
5930                strbuf_release(&sb);
5931        }
5932}
5933
5934static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5935                struct diff_filepair *p)
5936{
5937        struct strbuf sb = STRBUF_INIT;
5938        struct strbuf names = STRBUF_INIT;
5939
5940        pprint_rename(&names, p->one->path, p->two->path);
5941        strbuf_addf(&sb, " %s %s (%d%%)\n",
5942                    renamecopy, names.buf, similarity_index(p));
5943        strbuf_release(&names);
5944        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5945                                 sb.buf, sb.len, 0);
5946        show_mode_change(opt, p, 0);
5947        strbuf_release(&sb);
5948}
5949
5950static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5951{
5952        switch(p->status) {
5953        case DIFF_STATUS_DELETED:
5954                show_file_mode_name(opt, "delete", p->one);
5955                break;
5956        case DIFF_STATUS_ADDED:
5957                show_file_mode_name(opt, "create", p->two);
5958                break;
5959        case DIFF_STATUS_COPIED:
5960                show_rename_copy(opt, "copy", p);
5961                break;
5962        case DIFF_STATUS_RENAMED:
5963                show_rename_copy(opt, "rename", p);
5964                break;
5965        default:
5966                if (p->score) {
5967                        struct strbuf sb = STRBUF_INIT;
5968                        strbuf_addstr(&sb, " rewrite ");
5969                        quote_c_style(p->two->path, &sb, NULL, 0);
5970                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5971                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5972                                         sb.buf, sb.len, 0);
5973                        strbuf_release(&sb);
5974                }
5975                show_mode_change(opt, p, !p->score);
5976                break;
5977        }
5978}
5979
5980struct patch_id_t {
5981        git_SHA_CTX *ctx;
5982        int patchlen;
5983};
5984
5985static int remove_space(char *line, int len)
5986{
5987        int i;
5988        char *dst = line;
5989        unsigned char c;
5990
5991        for (i = 0; i < len; i++)
5992                if (!isspace((c = line[i])))
5993                        *dst++ = c;
5994
5995        return dst - line;
5996}
5997
5998void flush_one_hunk(struct object_id *result, git_SHA_CTX *ctx)
5999{
6000        unsigned char hash[GIT_MAX_RAWSZ];
6001        unsigned short carry = 0;
6002        int i;
6003
6004        git_SHA1_Final(hash, ctx);
6005        git_SHA1_Init(ctx);
6006        /* 20-byte sum, with carry */
6007        for (i = 0; i < GIT_SHA1_RAWSZ; ++i) {
6008                carry += result->hash[i] + hash[i];
6009                result->hash[i] = carry;
6010                carry >>= 8;
6011        }
6012}
6013
6014static void patch_id_consume(void *priv, char *line, unsigned long len)
6015{
6016        struct patch_id_t *data = priv;
6017        int new_len;
6018
6019        new_len = remove_space(line, len);
6020
6021        git_SHA1_Update(data->ctx, line, new_len);
6022        data->patchlen += new_len;
6023}
6024
6025static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
6026{
6027        git_SHA1_Update(ctx, str, strlen(str));
6028}
6029
6030static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
6031{
6032        /* large enough for 2^32 in octal */
6033        char buf[12];
6034        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
6035        git_SHA1_Update(ctx, buf, len);
6036}
6037
6038/* returns 0 upon success, and writes result into oid */
6039static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only, int stable)
6040{
6041        struct diff_queue_struct *q = &diff_queued_diff;
6042        int i;
6043        git_SHA_CTX ctx;
6044        struct patch_id_t data;
6045
6046        git_SHA1_Init(&ctx);
6047        memset(&data, 0, sizeof(struct patch_id_t));
6048        data.ctx = &ctx;
6049        oidclr(oid);
6050
6051        for (i = 0; i < q->nr; i++) {
6052                xpparam_t xpp;
6053                xdemitconf_t xecfg;
6054                mmfile_t mf1, mf2;
6055                struct diff_filepair *p = q->queue[i];
6056                int len1, len2;
6057
6058                memset(&xpp, 0, sizeof(xpp));
6059                memset(&xecfg, 0, sizeof(xecfg));
6060                if (p->status == 0)
6061                        return error("internal diff status error");
6062                if (p->status == DIFF_STATUS_UNKNOWN)
6063                        continue;
6064                if (diff_unmodified_pair(p))
6065                        continue;
6066                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
6067                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
6068                        continue;
6069                if (DIFF_PAIR_UNMERGED(p))
6070                        continue;
6071
6072                diff_fill_oid_info(p->one, options->repo->index);
6073                diff_fill_oid_info(p->two, options->repo->index);
6074
6075                len1 = remove_space(p->one->path, strlen(p->one->path));
6076                len2 = remove_space(p->two->path, strlen(p->two->path));
6077                patch_id_add_string(&ctx, "diff--git");
6078                patch_id_add_string(&ctx, "a/");
6079                git_SHA1_Update(&ctx, p->one->path, len1);
6080                patch_id_add_string(&ctx, "b/");
6081                git_SHA1_Update(&ctx, p->two->path, len2);
6082
6083                if (p->one->mode == 0) {
6084                        patch_id_add_string(&ctx, "newfilemode");
6085                        patch_id_add_mode(&ctx, p->two->mode);
6086                        patch_id_add_string(&ctx, "---/dev/null");
6087                        patch_id_add_string(&ctx, "+++b/");
6088                        git_SHA1_Update(&ctx, p->two->path, len2);
6089                } else if (p->two->mode == 0) {
6090                        patch_id_add_string(&ctx, "deletedfilemode");
6091                        patch_id_add_mode(&ctx, p->one->mode);
6092                        patch_id_add_string(&ctx, "---a/");
6093                        git_SHA1_Update(&ctx, p->one->path, len1);
6094                        patch_id_add_string(&ctx, "+++/dev/null");
6095                } else {
6096                        patch_id_add_string(&ctx, "---a/");
6097                        git_SHA1_Update(&ctx, p->one->path, len1);
6098                        patch_id_add_string(&ctx, "+++b/");
6099                        git_SHA1_Update(&ctx, p->two->path, len2);
6100                }
6101
6102                if (diff_header_only)
6103                        continue;
6104
6105                if (fill_mmfile(options->repo, &mf1, p->one) < 0 ||
6106                    fill_mmfile(options->repo, &mf2, p->two) < 0)
6107                        return error("unable to read files to diff");
6108
6109                if (diff_filespec_is_binary(options->repo, p->one) ||
6110                    diff_filespec_is_binary(options->repo, p->two)) {
6111                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
6112                                        GIT_SHA1_HEXSZ);
6113                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
6114                                        GIT_SHA1_HEXSZ);
6115                        continue;
6116                }
6117
6118                xpp.flags = 0;
6119                xecfg.ctxlen = 3;
6120                xecfg.flags = 0;
6121                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
6122                                  patch_id_consume, &data, &xpp, &xecfg))
6123                        return error("unable to generate patch-id diff for %s",
6124                                     p->one->path);
6125
6126                if (stable)
6127                        flush_one_hunk(oid, &ctx);
6128        }
6129
6130        if (!stable)
6131                git_SHA1_Final(oid->hash, &ctx);
6132
6133        return 0;
6134}
6135
6136int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only, int stable)
6137{
6138        struct diff_queue_struct *q = &diff_queued_diff;
6139        int i;
6140        int result = diff_get_patch_id(options, oid, diff_header_only, stable);
6141
6142        for (i = 0; i < q->nr; i++)
6143                diff_free_filepair(q->queue[i]);
6144
6145        free(q->queue);
6146        DIFF_QUEUE_CLEAR(q);
6147
6148        return result;
6149}
6150
6151static int is_summary_empty(const struct diff_queue_struct *q)
6152{
6153        int i;
6154
6155        for (i = 0; i < q->nr; i++) {
6156                const struct diff_filepair *p = q->queue[i];
6157
6158                switch (p->status) {
6159                case DIFF_STATUS_DELETED:
6160                case DIFF_STATUS_ADDED:
6161                case DIFF_STATUS_COPIED:
6162                case DIFF_STATUS_RENAMED:
6163                        return 0;
6164                default:
6165                        if (p->score)
6166                                return 0;
6167                        if (p->one->mode && p->two->mode &&
6168                            p->one->mode != p->two->mode)
6169                                return 0;
6170                        break;
6171                }
6172        }
6173        return 1;
6174}
6175
6176static const char rename_limit_warning[] =
6177N_("inexact rename detection was skipped due to too many files.");
6178
6179static const char degrade_cc_to_c_warning[] =
6180N_("only found copies from modified paths due to too many files.");
6181
6182static const char rename_limit_advice[] =
6183N_("you may want to set your %s variable to at least "
6184   "%d and retry the command.");
6185
6186void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
6187{
6188        fflush(stdout);
6189        if (degraded_cc)
6190                warning(_(degrade_cc_to_c_warning));
6191        else if (needed)
6192                warning(_(rename_limit_warning));
6193        else
6194                return;
6195        if (0 < needed)
6196                warning(_(rename_limit_advice), varname, needed);
6197}
6198
6199static void diff_flush_patch_all_file_pairs(struct diff_options *o)
6200{
6201        int i;
6202        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
6203        struct diff_queue_struct *q = &diff_queued_diff;
6204
6205        if (WSEH_NEW & WS_RULE_MASK)
6206                BUG("WS rules bit mask overlaps with diff symbol flags");
6207
6208        if (o->color_moved)
6209                o->emitted_symbols = &esm;
6210
6211        for (i = 0; i < q->nr; i++) {
6212                struct diff_filepair *p = q->queue[i];
6213                if (check_pair_status(p))
6214                        diff_flush_patch(p, o);
6215        }
6216
6217        if (o->emitted_symbols) {
6218                if (o->color_moved) {
6219                        struct hashmap add_lines, del_lines;
6220
6221                        if (o->color_moved_ws_handling &
6222                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
6223                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
6224
6225                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
6226                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
6227
6228                        add_lines_to_move_detection(o, &add_lines, &del_lines);
6229                        mark_color_as_moved(o, &add_lines, &del_lines);
6230                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
6231                                dim_moved_lines(o);
6232
6233                        hashmap_free(&add_lines, 1);
6234                        hashmap_free(&del_lines, 1);
6235                }
6236
6237                for (i = 0; i < esm.nr; i++)
6238                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
6239
6240                for (i = 0; i < esm.nr; i++)
6241                        free((void *)esm.buf[i].line);
6242                esm.nr = 0;
6243
6244                o->emitted_symbols = NULL;
6245        }
6246}
6247
6248void diff_flush(struct diff_options *options)
6249{
6250        struct diff_queue_struct *q = &diff_queued_diff;
6251        int i, output_format = options->output_format;
6252        int separator = 0;
6253        int dirstat_by_line = 0;
6254
6255        /*
6256         * Order: raw, stat, summary, patch
6257         * or:    name/name-status/checkdiff (other bits clear)
6258         */
6259        if (!q->nr)
6260                goto free_queue;
6261
6262        if (output_format & (DIFF_FORMAT_RAW |
6263                             DIFF_FORMAT_NAME |
6264                             DIFF_FORMAT_NAME_STATUS |
6265                             DIFF_FORMAT_CHECKDIFF)) {
6266                for (i = 0; i < q->nr; i++) {
6267                        struct diff_filepair *p = q->queue[i];
6268                        if (check_pair_status(p))
6269                                flush_one_pair(p, options);
6270                }
6271                separator++;
6272        }
6273
6274        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
6275                dirstat_by_line = 1;
6276
6277        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
6278            dirstat_by_line) {
6279                struct diffstat_t diffstat;
6280
6281                memset(&diffstat, 0, sizeof(struct diffstat_t));
6282                for (i = 0; i < q->nr; i++) {
6283                        struct diff_filepair *p = q->queue[i];
6284                        if (check_pair_status(p))
6285                                diff_flush_stat(p, options, &diffstat);
6286                }
6287                if (output_format & DIFF_FORMAT_NUMSTAT)
6288                        show_numstat(&diffstat, options);
6289                if (output_format & DIFF_FORMAT_DIFFSTAT)
6290                        show_stats(&diffstat, options);
6291                if (output_format & DIFF_FORMAT_SHORTSTAT)
6292                        show_shortstats(&diffstat, options);
6293                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
6294                        show_dirstat_by_line(&diffstat, options);
6295                free_diffstat_info(&diffstat);
6296                separator++;
6297        }
6298        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
6299                show_dirstat(options);
6300
6301        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
6302                for (i = 0; i < q->nr; i++) {
6303                        diff_summary(options, q->queue[i]);
6304                }
6305                separator++;
6306        }
6307
6308        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
6309            options->flags.exit_with_status &&
6310            options->flags.diff_from_contents) {
6311                /*
6312                 * run diff_flush_patch for the exit status. setting
6313                 * options->file to /dev/null should be safe, because we
6314                 * aren't supposed to produce any output anyway.
6315                 */
6316                if (options->close_file)
6317                        fclose(options->file);
6318                options->file = xfopen("/dev/null", "w");
6319                options->close_file = 1;
6320                options->color_moved = 0;
6321                for (i = 0; i < q->nr; i++) {
6322                        struct diff_filepair *p = q->queue[i];
6323                        if (check_pair_status(p))
6324                                diff_flush_patch(p, options);
6325                        if (options->found_changes)
6326                                break;
6327                }
6328        }
6329
6330        if (output_format & DIFF_FORMAT_PATCH) {
6331                if (separator) {
6332                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
6333                        if (options->stat_sep)
6334                                /* attach patch instead of inline */
6335                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
6336                                                 NULL, 0, 0);
6337                }
6338
6339                diff_flush_patch_all_file_pairs(options);
6340        }
6341
6342        if (output_format & DIFF_FORMAT_CALLBACK)
6343                options->format_callback(q, options, options->format_callback_data);
6344
6345        for (i = 0; i < q->nr; i++)
6346                diff_free_filepair(q->queue[i]);
6347free_queue:
6348        free(q->queue);
6349        DIFF_QUEUE_CLEAR(q);
6350        if (options->close_file)
6351                fclose(options->file);
6352
6353        /*
6354         * Report the content-level differences with HAS_CHANGES;
6355         * diff_addremove/diff_change does not set the bit when
6356         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
6357         */
6358        if (options->flags.diff_from_contents) {
6359                if (options->found_changes)
6360                        options->flags.has_changes = 1;
6361                else
6362                        options->flags.has_changes = 0;
6363        }
6364}
6365
6366static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
6367{
6368        return (((p->status == DIFF_STATUS_MODIFIED) &&
6369                 ((p->score &&
6370                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
6371                  (!p->score &&
6372                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
6373                ((p->status != DIFF_STATUS_MODIFIED) &&
6374                 filter_bit_tst(p->status, options)));
6375}
6376
6377static void diffcore_apply_filter(struct diff_options *options)
6378{
6379        int i;
6380        struct diff_queue_struct *q = &diff_queued_diff;
6381        struct diff_queue_struct outq;
6382
6383        DIFF_QUEUE_CLEAR(&outq);
6384
6385        if (!options->filter)
6386                return;
6387
6388        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
6389                int found;
6390                for (i = found = 0; !found && i < q->nr; i++) {
6391                        if (match_filter(options, q->queue[i]))
6392                                found++;
6393                }
6394                if (found)
6395                        return;
6396
6397                /* otherwise we will clear the whole queue
6398                 * by copying the empty outq at the end of this
6399                 * function, but first clear the current entries
6400                 * in the queue.
6401                 */
6402                for (i = 0; i < q->nr; i++)
6403                        diff_free_filepair(q->queue[i]);
6404        }
6405        else {
6406                /* Only the matching ones */
6407                for (i = 0; i < q->nr; i++) {
6408                        struct diff_filepair *p = q->queue[i];
6409                        if (match_filter(options, p))
6410                                diff_q(&outq, p);
6411                        else
6412                                diff_free_filepair(p);
6413                }
6414        }
6415        free(q->queue);
6416        *q = outq;
6417}
6418
6419/* Check whether two filespecs with the same mode and size are identical */
6420static int diff_filespec_is_identical(struct repository *r,
6421                                      struct diff_filespec *one,
6422                                      struct diff_filespec *two)
6423{
6424        if (S_ISGITLINK(one->mode))
6425                return 0;
6426        if (diff_populate_filespec(r, one, 0))
6427                return 0;
6428        if (diff_populate_filespec(r, two, 0))
6429                return 0;
6430        return !memcmp(one->data, two->data, one->size);
6431}
6432
6433static int diff_filespec_check_stat_unmatch(struct repository *r,
6434                                            struct diff_filepair *p)
6435{
6436        if (p->done_skip_stat_unmatch)
6437                return p->skip_stat_unmatch_result;
6438
6439        p->done_skip_stat_unmatch = 1;
6440        p->skip_stat_unmatch_result = 0;
6441        /*
6442         * 1. Entries that come from stat info dirtiness
6443         *    always have both sides (iow, not create/delete),
6444         *    one side of the object name is unknown, with
6445         *    the same mode and size.  Keep the ones that
6446         *    do not match these criteria.  They have real
6447         *    differences.
6448         *
6449         * 2. At this point, the file is known to be modified,
6450         *    with the same mode and size, and the object
6451         *    name of one side is unknown.  Need to inspect
6452         *    the identical contents.
6453         */
6454        if (!DIFF_FILE_VALID(p->one) || /* (1) */
6455            !DIFF_FILE_VALID(p->two) ||
6456            (p->one->oid_valid && p->two->oid_valid) ||
6457            (p->one->mode != p->two->mode) ||
6458            diff_populate_filespec(r, p->one, CHECK_SIZE_ONLY) ||
6459            diff_populate_filespec(r, p->two, CHECK_SIZE_ONLY) ||
6460            (p->one->size != p->two->size) ||
6461            !diff_filespec_is_identical(r, p->one, p->two)) /* (2) */
6462                p->skip_stat_unmatch_result = 1;
6463        return p->skip_stat_unmatch_result;
6464}
6465
6466static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
6467{
6468        int i;
6469        struct diff_queue_struct *q = &diff_queued_diff;
6470        struct diff_queue_struct outq;
6471        DIFF_QUEUE_CLEAR(&outq);
6472
6473        for (i = 0; i < q->nr; i++) {
6474                struct diff_filepair *p = q->queue[i];
6475
6476                if (diff_filespec_check_stat_unmatch(diffopt->repo, p))
6477                        diff_q(&outq, p);
6478                else {
6479                        /*
6480                         * The caller can subtract 1 from skip_stat_unmatch
6481                         * to determine how many paths were dirty only
6482                         * due to stat info mismatch.
6483                         */
6484                        if (!diffopt->flags.no_index)
6485                                diffopt->skip_stat_unmatch++;
6486                        diff_free_filepair(p);
6487                }
6488        }
6489        free(q->queue);
6490        *q = outq;
6491}
6492
6493static int diffnamecmp(const void *a_, const void *b_)
6494{
6495        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6496        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6497        const char *name_a, *name_b;
6498
6499        name_a = a->one ? a->one->path : a->two->path;
6500        name_b = b->one ? b->one->path : b->two->path;
6501        return strcmp(name_a, name_b);
6502}
6503
6504void diffcore_fix_diff_index(void)
6505{
6506        struct diff_queue_struct *q = &diff_queued_diff;
6507        QSORT(q->queue, q->nr, diffnamecmp);
6508}
6509
6510static void add_if_missing(struct repository *r,
6511                           struct oid_array *to_fetch,
6512                           const struct diff_filespec *filespec)
6513{
6514        if (filespec && filespec->oid_valid &&
6515            !S_ISGITLINK(filespec->mode) &&
6516            oid_object_info_extended(r, &filespec->oid, NULL,
6517                                     OBJECT_INFO_FOR_PREFETCH))
6518                oid_array_append(to_fetch, &filespec->oid);
6519}
6520
6521void diffcore_std(struct diff_options *options)
6522{
6523        if (options->repo == the_repository && has_promisor_remote()) {
6524                /*
6525                 * Prefetch the diff pairs that are about to be flushed.
6526                 */
6527                int i;
6528                struct diff_queue_struct *q = &diff_queued_diff;
6529                struct oid_array to_fetch = OID_ARRAY_INIT;
6530
6531                for (i = 0; i < q->nr; i++) {
6532                        struct diff_filepair *p = q->queue[i];
6533                        add_if_missing(options->repo, &to_fetch, p->one);
6534                        add_if_missing(options->repo, &to_fetch, p->two);
6535                }
6536                if (to_fetch.nr)
6537                        /*
6538                         * NEEDSWORK: Consider deduplicating the OIDs sent.
6539                         */
6540                        promisor_remote_get_direct(options->repo,
6541                                                   to_fetch.oid, to_fetch.nr);
6542                oid_array_clear(&to_fetch);
6543        }
6544
6545        /* NOTE please keep the following in sync with diff_tree_combined() */
6546        if (options->skip_stat_unmatch)
6547                diffcore_skip_stat_unmatch(options);
6548        if (!options->found_follow) {
6549                /* See try_to_follow_renames() in tree-diff.c */
6550                if (options->break_opt != -1)
6551                        diffcore_break(options->repo,
6552                                       options->break_opt);
6553                if (options->detect_rename)
6554                        diffcore_rename(options);
6555                if (options->break_opt != -1)
6556                        diffcore_merge_broken();
6557        }
6558        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6559                diffcore_pickaxe(options);
6560        if (options->orderfile)
6561                diffcore_order(options->orderfile);
6562        if (!options->found_follow)
6563                /* See try_to_follow_renames() in tree-diff.c */
6564                diff_resolve_rename_copy();
6565        diffcore_apply_filter(options);
6566
6567        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6568                options->flags.has_changes = 1;
6569        else
6570                options->flags.has_changes = 0;
6571
6572        options->found_follow = 0;
6573}
6574
6575int diff_result_code(struct diff_options *opt, int status)
6576{
6577        int result = 0;
6578
6579        diff_warn_rename_limit("diff.renameLimit",
6580                               opt->needed_rename_limit,
6581                               opt->degraded_cc_to_c);
6582        if (!opt->flags.exit_with_status &&
6583            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6584                return status;
6585        if (opt->flags.exit_with_status &&
6586            opt->flags.has_changes)
6587                result |= 01;
6588        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6589            opt->flags.check_failed)
6590                result |= 02;
6591        return result;
6592}
6593
6594int diff_can_quit_early(struct diff_options *opt)
6595{
6596        return (opt->flags.quick &&
6597                !opt->filter &&
6598                opt->flags.has_changes);
6599}
6600
6601/*
6602 * Shall changes to this submodule be ignored?
6603 *
6604 * Submodule changes can be configured to be ignored separately for each path,
6605 * but that configuration can be overridden from the command line.
6606 */
6607static int is_submodule_ignored(const char *path, struct diff_options *options)
6608{
6609        int ignored = 0;
6610        struct diff_flags orig_flags = options->flags;
6611        if (!options->flags.override_submodule_config)
6612                set_diffopt_flags_from_submodule_config(options, path);
6613        if (options->flags.ignore_submodules)
6614                ignored = 1;
6615        options->flags = orig_flags;
6616        return ignored;
6617}
6618
6619void diff_addremove(struct diff_options *options,
6620                    int addremove, unsigned mode,
6621                    const struct object_id *oid,
6622                    int oid_valid,
6623                    const char *concatpath, unsigned dirty_submodule)
6624{
6625        struct diff_filespec *one, *two;
6626
6627        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6628                return;
6629
6630        /* This may look odd, but it is a preparation for
6631         * feeding "there are unchanged files which should
6632         * not produce diffs, but when you are doing copy
6633         * detection you would need them, so here they are"
6634         * entries to the diff-core.  They will be prefixed
6635         * with something like '=' or '*' (I haven't decided
6636         * which but should not make any difference).
6637         * Feeding the same new and old to diff_change()
6638         * also has the same effect.
6639         * Before the final output happens, they are pruned after
6640         * merged into rename/copy pairs as appropriate.
6641         */
6642        if (options->flags.reverse_diff)
6643                addremove = (addremove == '+' ? '-' :
6644                             addremove == '-' ? '+' : addremove);
6645
6646        if (options->prefix &&
6647            strncmp(concatpath, options->prefix, options->prefix_length))
6648                return;
6649
6650        one = alloc_filespec(concatpath);
6651        two = alloc_filespec(concatpath);
6652
6653        if (addremove != '+')
6654                fill_filespec(one, oid, oid_valid, mode);
6655        if (addremove != '-') {
6656                fill_filespec(two, oid, oid_valid, mode);
6657                two->dirty_submodule = dirty_submodule;
6658        }
6659
6660        diff_queue(&diff_queued_diff, one, two);
6661        if (!options->flags.diff_from_contents)
6662                options->flags.has_changes = 1;
6663}
6664
6665void diff_change(struct diff_options *options,
6666                 unsigned old_mode, unsigned new_mode,
6667                 const struct object_id *old_oid,
6668                 const struct object_id *new_oid,
6669                 int old_oid_valid, int new_oid_valid,
6670                 const char *concatpath,
6671                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6672{
6673        struct diff_filespec *one, *two;
6674        struct diff_filepair *p;
6675
6676        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6677            is_submodule_ignored(concatpath, options))
6678                return;
6679
6680        if (options->flags.reverse_diff) {
6681                SWAP(old_mode, new_mode);
6682                SWAP(old_oid, new_oid);
6683                SWAP(old_oid_valid, new_oid_valid);
6684                SWAP(old_dirty_submodule, new_dirty_submodule);
6685        }
6686
6687        if (options->prefix &&
6688            strncmp(concatpath, options->prefix, options->prefix_length))
6689                return;
6690
6691        one = alloc_filespec(concatpath);
6692        two = alloc_filespec(concatpath);
6693        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6694        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6695        one->dirty_submodule = old_dirty_submodule;
6696        two->dirty_submodule = new_dirty_submodule;
6697        p = diff_queue(&diff_queued_diff, one, two);
6698
6699        if (options->flags.diff_from_contents)
6700                return;
6701
6702        if (options->flags.quick && options->skip_stat_unmatch &&
6703            !diff_filespec_check_stat_unmatch(options->repo, p))
6704                return;
6705
6706        options->flags.has_changes = 1;
6707}
6708
6709struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6710{
6711        struct diff_filepair *pair;
6712        struct diff_filespec *one, *two;
6713
6714        if (options->prefix &&
6715            strncmp(path, options->prefix, options->prefix_length))
6716                return NULL;
6717
6718        one = alloc_filespec(path);
6719        two = alloc_filespec(path);
6720        pair = diff_queue(&diff_queued_diff, one, two);
6721        pair->is_unmerged = 1;
6722        return pair;
6723}
6724
6725static char *run_textconv(struct repository *r,
6726                          const char *pgm,
6727                          struct diff_filespec *spec,
6728                          size_t *outsize)
6729{
6730        struct diff_tempfile *temp;
6731        const char *argv[3];
6732        const char **arg = argv;
6733        struct child_process child = CHILD_PROCESS_INIT;
6734        struct strbuf buf = STRBUF_INIT;
6735        int err = 0;
6736
6737        temp = prepare_temp_file(r, spec->path, spec);
6738        *arg++ = pgm;
6739        *arg++ = temp->name;
6740        *arg = NULL;
6741
6742        child.use_shell = 1;
6743        child.argv = argv;
6744        child.out = -1;
6745        if (start_command(&child)) {
6746                remove_tempfile();
6747                return NULL;
6748        }
6749
6750        if (strbuf_read(&buf, child.out, 0) < 0)
6751                err = error("error reading from textconv command '%s'", pgm);
6752        close(child.out);
6753
6754        if (finish_command(&child) || err) {
6755                strbuf_release(&buf);
6756                remove_tempfile();
6757                return NULL;
6758        }
6759        remove_tempfile();
6760
6761        return strbuf_detach(&buf, outsize);
6762}
6763
6764size_t fill_textconv(struct repository *r,
6765                     struct userdiff_driver *driver,
6766                     struct diff_filespec *df,
6767                     char **outbuf)
6768{
6769        size_t size;
6770
6771        if (!driver) {
6772                if (!DIFF_FILE_VALID(df)) {
6773                        *outbuf = "";
6774                        return 0;
6775                }
6776                if (diff_populate_filespec(r, df, 0))
6777                        die("unable to read files to diff");
6778                *outbuf = df->data;
6779                return df->size;
6780        }
6781
6782        if (!driver->textconv)
6783                BUG("fill_textconv called with non-textconv driver");
6784
6785        if (driver->textconv_cache && df->oid_valid) {
6786                *outbuf = notes_cache_get(driver->textconv_cache,
6787                                          &df->oid,
6788                                          &size);
6789                if (*outbuf)
6790                        return size;
6791        }
6792
6793        *outbuf = run_textconv(r, driver->textconv, df, &size);
6794        if (!*outbuf)
6795                die("unable to read files to diff");
6796
6797        if (driver->textconv_cache && df->oid_valid) {
6798                /* ignore errors, as we might be in a readonly repository */
6799                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6800                                size);
6801                /*
6802                 * we could save up changes and flush them all at the end,
6803                 * but we would need an extra call after all diffing is done.
6804                 * Since generating a cache entry is the slow path anyway,
6805                 * this extra overhead probably isn't a big deal.
6806                 */
6807                notes_cache_write(driver->textconv_cache);
6808        }
6809
6810        return size;
6811}
6812
6813int textconv_object(struct repository *r,
6814                    const char *path,
6815                    unsigned mode,
6816                    const struct object_id *oid,
6817                    int oid_valid,
6818                    char **buf,
6819                    unsigned long *buf_size)
6820{
6821        struct diff_filespec *df;
6822        struct userdiff_driver *textconv;
6823
6824        df = alloc_filespec(path);
6825        fill_filespec(df, oid, oid_valid, mode);
6826        textconv = get_textconv(r, df);
6827        if (!textconv) {
6828                free_filespec(df);
6829                return 0;
6830        }
6831
6832        *buf_size = fill_textconv(r, textconv, df, buf);
6833        free_filespec(df);
6834        return 1;
6835}
6836
6837void setup_diff_pager(struct diff_options *opt)
6838{
6839        /*
6840         * If the user asked for our exit code, then either they want --quiet
6841         * or --exit-code. We should definitely not bother with a pager in the
6842         * former case, as we will generate no output. Since we still properly
6843         * report our exit code even when a pager is run, we _could_ run a
6844         * pager with --exit-code. But since we have not done so historically,
6845         * and because it is easy to find people oneline advising "git diff
6846         * --exit-code" in hooks and other scripts, we do not do so.
6847         */
6848        if (!opt->flags.exit_with_status &&
6849            check_pager_config("diff") != 0)
6850                setup_pager();
6851}