diff.con commit msvc: define O_ACCMODE (a822fb8)
   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 "fetch-object.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        strbuf_add(&msgbuf, line, ep - line);
1677        strbuf_addstr(&msgbuf, reset);
1678
1679        /*
1680         * trailing "\r\n"
1681         */
1682        for ( ; i < 3; i++)
1683                if (line[len - i] == '\r' || line[len - i] == '\n')
1684                        len--;
1685
1686        /* blank before the func header */
1687        for (cp = ep; ep - line < len; ep++)
1688                if (*ep != ' ' && *ep != '\t')
1689                        break;
1690        if (ep != cp) {
1691                strbuf_addstr(&msgbuf, context);
1692                strbuf_add(&msgbuf, cp, ep - cp);
1693                strbuf_addstr(&msgbuf, reset);
1694        }
1695
1696        if (ep < line + len) {
1697                strbuf_addstr(&msgbuf, func);
1698                strbuf_add(&msgbuf, ep, line + len - ep);
1699                strbuf_addstr(&msgbuf, reset);
1700        }
1701
1702        strbuf_add(&msgbuf, line + len, org_len - len);
1703        strbuf_complete_line(&msgbuf);
1704        emit_diff_symbol(ecbdata->opt,
1705                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1706        strbuf_release(&msgbuf);
1707}
1708
1709static struct diff_tempfile *claim_diff_tempfile(void)
1710{
1711        int i;
1712        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1713                if (!diff_temp[i].name)
1714                        return diff_temp + i;
1715        BUG("diff is failing to clean up its tempfiles");
1716}
1717
1718static void remove_tempfile(void)
1719{
1720        int i;
1721        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1722                if (is_tempfile_active(diff_temp[i].tempfile))
1723                        delete_tempfile(&diff_temp[i].tempfile);
1724                diff_temp[i].name = NULL;
1725        }
1726}
1727
1728static void add_line_count(struct strbuf *out, int count)
1729{
1730        switch (count) {
1731        case 0:
1732                strbuf_addstr(out, "0,0");
1733                break;
1734        case 1:
1735                strbuf_addstr(out, "1");
1736                break;
1737        default:
1738                strbuf_addf(out, "1,%d", count);
1739                break;
1740        }
1741}
1742
1743static void emit_rewrite_lines(struct emit_callback *ecb,
1744                               int prefix, const char *data, int size)
1745{
1746        const char *endp = NULL;
1747
1748        while (0 < size) {
1749                int len;
1750
1751                endp = memchr(data, '\n', size);
1752                len = endp ? (endp - data + 1) : size;
1753                if (prefix != '+') {
1754                        ecb->lno_in_preimage++;
1755                        emit_del_line(ecb, data, len);
1756                } else {
1757                        ecb->lno_in_postimage++;
1758                        emit_add_line(ecb, data, len);
1759                }
1760                size -= len;
1761                data += len;
1762        }
1763        if (!endp)
1764                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1765}
1766
1767static void emit_rewrite_diff(const char *name_a,
1768                              const char *name_b,
1769                              struct diff_filespec *one,
1770                              struct diff_filespec *two,
1771                              struct userdiff_driver *textconv_one,
1772                              struct userdiff_driver *textconv_two,
1773                              struct diff_options *o)
1774{
1775        int lc_a, lc_b;
1776        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1777        const char *a_prefix, *b_prefix;
1778        char *data_one, *data_two;
1779        size_t size_one, size_two;
1780        struct emit_callback ecbdata;
1781        struct strbuf out = STRBUF_INIT;
1782
1783        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1784                a_prefix = o->b_prefix;
1785                b_prefix = o->a_prefix;
1786        } else {
1787                a_prefix = o->a_prefix;
1788                b_prefix = o->b_prefix;
1789        }
1790
1791        name_a += (*name_a == '/');
1792        name_b += (*name_b == '/');
1793
1794        strbuf_reset(&a_name);
1795        strbuf_reset(&b_name);
1796        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1797        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1798
1799        size_one = fill_textconv(o->repo, textconv_one, one, &data_one);
1800        size_two = fill_textconv(o->repo, textconv_two, two, &data_two);
1801
1802        memset(&ecbdata, 0, sizeof(ecbdata));
1803        ecbdata.color_diff = want_color(o->use_color);
1804        ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
1805        ecbdata.opt = o;
1806        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1807                mmfile_t mf1, mf2;
1808                mf1.ptr = (char *)data_one;
1809                mf2.ptr = (char *)data_two;
1810                mf1.size = size_one;
1811                mf2.size = size_two;
1812                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1813        }
1814        ecbdata.lno_in_preimage = 1;
1815        ecbdata.lno_in_postimage = 1;
1816
1817        lc_a = count_lines(data_one, size_one);
1818        lc_b = count_lines(data_two, size_two);
1819
1820        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1821                         a_name.buf, a_name.len, 0);
1822        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1823                         b_name.buf, b_name.len, 0);
1824
1825        strbuf_addstr(&out, "@@ -");
1826        if (!o->irreversible_delete)
1827                add_line_count(&out, lc_a);
1828        else
1829                strbuf_addstr(&out, "?,?");
1830        strbuf_addstr(&out, " +");
1831        add_line_count(&out, lc_b);
1832        strbuf_addstr(&out, " @@\n");
1833        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1834        strbuf_release(&out);
1835
1836        if (lc_a && !o->irreversible_delete)
1837                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1838        if (lc_b)
1839                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1840        if (textconv_one)
1841                free((char *)data_one);
1842        if (textconv_two)
1843                free((char *)data_two);
1844}
1845
1846struct diff_words_buffer {
1847        mmfile_t text;
1848        unsigned long alloc;
1849        struct diff_words_orig {
1850                const char *begin, *end;
1851        } *orig;
1852        int orig_nr, orig_alloc;
1853};
1854
1855static void diff_words_append(char *line, unsigned long len,
1856                struct diff_words_buffer *buffer)
1857{
1858        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1859        line++;
1860        len--;
1861        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1862        buffer->text.size += len;
1863        buffer->text.ptr[buffer->text.size] = '\0';
1864}
1865
1866struct diff_words_style_elem {
1867        const char *prefix;
1868        const char *suffix;
1869        const char *color; /* NULL; filled in by the setup code if
1870                            * color is enabled */
1871};
1872
1873struct diff_words_style {
1874        enum diff_words_type type;
1875        struct diff_words_style_elem new_word, old_word, ctx;
1876        const char *newline;
1877};
1878
1879static struct diff_words_style diff_words_styles[] = {
1880        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1881        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1882        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1883};
1884
1885struct diff_words_data {
1886        struct diff_words_buffer minus, plus;
1887        const char *current_plus;
1888        int last_minus;
1889        struct diff_options *opt;
1890        regex_t *word_regex;
1891        enum diff_words_type type;
1892        struct diff_words_style *style;
1893};
1894
1895static int fn_out_diff_words_write_helper(struct diff_options *o,
1896                                          struct diff_words_style_elem *st_el,
1897                                          const char *newline,
1898                                          size_t count, const char *buf)
1899{
1900        int print = 0;
1901        struct strbuf sb = STRBUF_INIT;
1902
1903        while (count) {
1904                char *p = memchr(buf, '\n', count);
1905                if (print)
1906                        strbuf_addstr(&sb, diff_line_prefix(o));
1907
1908                if (p != buf) {
1909                        const char *reset = st_el->color && *st_el->color ?
1910                                            GIT_COLOR_RESET : NULL;
1911                        if (st_el->color && *st_el->color)
1912                                strbuf_addstr(&sb, st_el->color);
1913                        strbuf_addstr(&sb, st_el->prefix);
1914                        strbuf_add(&sb, buf, p ? p - buf : count);
1915                        strbuf_addstr(&sb, st_el->suffix);
1916                        if (reset)
1917                                strbuf_addstr(&sb, reset);
1918                }
1919                if (!p)
1920                        goto out;
1921
1922                strbuf_addstr(&sb, newline);
1923                count -= p + 1 - buf;
1924                buf = p + 1;
1925                print = 1;
1926                if (count) {
1927                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1928                                         sb.buf, sb.len, 0);
1929                        strbuf_reset(&sb);
1930                }
1931        }
1932
1933out:
1934        if (sb.len)
1935                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1936                                 sb.buf, sb.len, 0);
1937        strbuf_release(&sb);
1938        return 0;
1939}
1940
1941/*
1942 * '--color-words' algorithm can be described as:
1943 *
1944 *   1. collect the minus/plus lines of a diff hunk, divided into
1945 *      minus-lines and plus-lines;
1946 *
1947 *   2. break both minus-lines and plus-lines into words and
1948 *      place them into two mmfile_t with one word for each line;
1949 *
1950 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1951 *
1952 * And for the common parts of the both file, we output the plus side text.
1953 * diff_words->current_plus is used to trace the current position of the plus file
1954 * which printed. diff_words->last_minus is used to trace the last minus word
1955 * printed.
1956 *
1957 * For '--graph' to work with '--color-words', we need to output the graph prefix
1958 * on each line of color words output. Generally, there are two conditions on
1959 * which we should output the prefix.
1960 *
1961 *   1. diff_words->last_minus == 0 &&
1962 *      diff_words->current_plus == diff_words->plus.text.ptr
1963 *
1964 *      that is: the plus text must start as a new line, and if there is no minus
1965 *      word printed, a graph prefix must be printed.
1966 *
1967 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1968 *      *(diff_words->current_plus - 1) == '\n'
1969 *
1970 *      that is: a graph prefix must be printed following a '\n'
1971 */
1972static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1973{
1974        if ((diff_words->last_minus == 0 &&
1975                diff_words->current_plus == diff_words->plus.text.ptr) ||
1976                (diff_words->current_plus > diff_words->plus.text.ptr &&
1977                *(diff_words->current_plus - 1) == '\n')) {
1978                return 1;
1979        } else {
1980                return 0;
1981        }
1982}
1983
1984static void fn_out_diff_words_aux(void *priv,
1985                                  long minus_first, long minus_len,
1986                                  long plus_first, long plus_len,
1987                                  const char *func, long funclen)
1988{
1989        struct diff_words_data *diff_words = priv;
1990        struct diff_words_style *style = diff_words->style;
1991        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1992        struct diff_options *opt = diff_words->opt;
1993        const char *line_prefix;
1994
1995        assert(opt);
1996        line_prefix = diff_line_prefix(opt);
1997
1998        /* POSIX requires that first be decremented by one if len == 0... */
1999        if (minus_len) {
2000                minus_begin = diff_words->minus.orig[minus_first].begin;
2001                minus_end =
2002                        diff_words->minus.orig[minus_first + minus_len - 1].end;
2003        } else
2004                minus_begin = minus_end =
2005                        diff_words->minus.orig[minus_first].end;
2006
2007        if (plus_len) {
2008                plus_begin = diff_words->plus.orig[plus_first].begin;
2009                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
2010        } else
2011                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
2012
2013        if (color_words_output_graph_prefix(diff_words)) {
2014                fputs(line_prefix, diff_words->opt->file);
2015        }
2016        if (diff_words->current_plus != plus_begin) {
2017                fn_out_diff_words_write_helper(diff_words->opt,
2018                                &style->ctx, style->newline,
2019                                plus_begin - diff_words->current_plus,
2020                                diff_words->current_plus);
2021        }
2022        if (minus_begin != minus_end) {
2023                fn_out_diff_words_write_helper(diff_words->opt,
2024                                &style->old_word, style->newline,
2025                                minus_end - minus_begin, minus_begin);
2026        }
2027        if (plus_begin != plus_end) {
2028                fn_out_diff_words_write_helper(diff_words->opt,
2029                                &style->new_word, style->newline,
2030                                plus_end - plus_begin, plus_begin);
2031        }
2032
2033        diff_words->current_plus = plus_end;
2034        diff_words->last_minus = minus_first;
2035}
2036
2037/* This function starts looking at *begin, and returns 0 iff a word was found. */
2038static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
2039                int *begin, int *end)
2040{
2041        if (word_regex && *begin < buffer->size) {
2042                regmatch_t match[1];
2043                if (!regexec_buf(word_regex, buffer->ptr + *begin,
2044                                 buffer->size - *begin, 1, match, 0)) {
2045                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
2046                                        '\n', match[0].rm_eo - match[0].rm_so);
2047                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
2048                        *begin += match[0].rm_so;
2049                        return *begin >= *end;
2050                }
2051                return -1;
2052        }
2053
2054        /* find the next word */
2055        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
2056                (*begin)++;
2057        if (*begin >= buffer->size)
2058                return -1;
2059
2060        /* find the end of the word */
2061        *end = *begin + 1;
2062        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
2063                (*end)++;
2064
2065        return 0;
2066}
2067
2068/*
2069 * This function splits the words in buffer->text, stores the list with
2070 * newline separator into out, and saves the offsets of the original words
2071 * in buffer->orig.
2072 */
2073static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
2074                regex_t *word_regex)
2075{
2076        int i, j;
2077        long alloc = 0;
2078
2079        out->size = 0;
2080        out->ptr = NULL;
2081
2082        /* fake an empty "0th" word */
2083        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
2084        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
2085        buffer->orig_nr = 1;
2086
2087        for (i = 0; i < buffer->text.size; i++) {
2088                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
2089                        return;
2090
2091                /* store original boundaries */
2092                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
2093                                buffer->orig_alloc);
2094                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
2095                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
2096                buffer->orig_nr++;
2097
2098                /* store one word */
2099                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
2100                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
2101                out->ptr[out->size + j - i] = '\n';
2102                out->size += j - i + 1;
2103
2104                i = j - 1;
2105        }
2106}
2107
2108/* this executes the word diff on the accumulated buffers */
2109static void diff_words_show(struct diff_words_data *diff_words)
2110{
2111        xpparam_t xpp;
2112        xdemitconf_t xecfg;
2113        mmfile_t minus, plus;
2114        struct diff_words_style *style = diff_words->style;
2115
2116        struct diff_options *opt = diff_words->opt;
2117        const char *line_prefix;
2118
2119        assert(opt);
2120        line_prefix = diff_line_prefix(opt);
2121
2122        /* special case: only removal */
2123        if (!diff_words->plus.text.size) {
2124                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2125                                 line_prefix, strlen(line_prefix), 0);
2126                fn_out_diff_words_write_helper(diff_words->opt,
2127                        &style->old_word, style->newline,
2128                        diff_words->minus.text.size,
2129                        diff_words->minus.text.ptr);
2130                diff_words->minus.text.size = 0;
2131                return;
2132        }
2133
2134        diff_words->current_plus = diff_words->plus.text.ptr;
2135        diff_words->last_minus = 0;
2136
2137        memset(&xpp, 0, sizeof(xpp));
2138        memset(&xecfg, 0, sizeof(xecfg));
2139        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
2140        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
2141        xpp.flags = 0;
2142        /* as only the hunk header will be parsed, we need a 0-context */
2143        xecfg.ctxlen = 0;
2144        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, NULL,
2145                          diff_words, &xpp, &xecfg))
2146                die("unable to generate word diff");
2147        free(minus.ptr);
2148        free(plus.ptr);
2149        if (diff_words->current_plus != diff_words->plus.text.ptr +
2150                        diff_words->plus.text.size) {
2151                if (color_words_output_graph_prefix(diff_words))
2152                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2153                                         line_prefix, strlen(line_prefix), 0);
2154                fn_out_diff_words_write_helper(diff_words->opt,
2155                        &style->ctx, style->newline,
2156                        diff_words->plus.text.ptr + diff_words->plus.text.size
2157                        - diff_words->current_plus, diff_words->current_plus);
2158        }
2159        diff_words->minus.text.size = diff_words->plus.text.size = 0;
2160}
2161
2162/* In "color-words" mode, show word-diff of words accumulated in the buffer */
2163static void diff_words_flush(struct emit_callback *ecbdata)
2164{
2165        struct diff_options *wo = ecbdata->diff_words->opt;
2166
2167        if (ecbdata->diff_words->minus.text.size ||
2168            ecbdata->diff_words->plus.text.size)
2169                diff_words_show(ecbdata->diff_words);
2170
2171        if (wo->emitted_symbols) {
2172                struct diff_options *o = ecbdata->opt;
2173                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2174                int i;
2175
2176                /*
2177                 * NEEDSWORK:
2178                 * Instead of appending each, concat all words to a line?
2179                 */
2180                for (i = 0; i < wol->nr; i++)
2181                        append_emitted_diff_symbol(o, &wol->buf[i]);
2182
2183                for (i = 0; i < wol->nr; i++)
2184                        free((void *)wol->buf[i].line);
2185
2186                wol->nr = 0;
2187        }
2188}
2189
2190static void diff_filespec_load_driver(struct diff_filespec *one,
2191                                      struct index_state *istate)
2192{
2193        /* Use already-loaded driver */
2194        if (one->driver)
2195                return;
2196
2197        if (S_ISREG(one->mode))
2198                one->driver = userdiff_find_by_path(istate, one->path);
2199
2200        /* Fallback to default settings */
2201        if (!one->driver)
2202                one->driver = userdiff_find_by_name("default");
2203}
2204
2205static const char *userdiff_word_regex(struct diff_filespec *one,
2206                                       struct index_state *istate)
2207{
2208        diff_filespec_load_driver(one, istate);
2209        return one->driver->word_regex;
2210}
2211
2212static void init_diff_words_data(struct emit_callback *ecbdata,
2213                                 struct diff_options *orig_opts,
2214                                 struct diff_filespec *one,
2215                                 struct diff_filespec *two)
2216{
2217        int i;
2218        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2219        memcpy(o, orig_opts, sizeof(struct diff_options));
2220
2221        ecbdata->diff_words =
2222                xcalloc(1, sizeof(struct diff_words_data));
2223        ecbdata->diff_words->type = o->word_diff;
2224        ecbdata->diff_words->opt = o;
2225
2226        if (orig_opts->emitted_symbols)
2227                o->emitted_symbols =
2228                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2229
2230        if (!o->word_regex)
2231                o->word_regex = userdiff_word_regex(one, o->repo->index);
2232        if (!o->word_regex)
2233                o->word_regex = userdiff_word_regex(two, o->repo->index);
2234        if (!o->word_regex)
2235                o->word_regex = diff_word_regex_cfg;
2236        if (o->word_regex) {
2237                ecbdata->diff_words->word_regex = (regex_t *)
2238                        xmalloc(sizeof(regex_t));
2239                if (regcomp(ecbdata->diff_words->word_regex,
2240                            o->word_regex,
2241                            REG_EXTENDED | REG_NEWLINE))
2242                        die("invalid regular expression: %s",
2243                            o->word_regex);
2244        }
2245        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2246                if (o->word_diff == diff_words_styles[i].type) {
2247                        ecbdata->diff_words->style =
2248                                &diff_words_styles[i];
2249                        break;
2250                }
2251        }
2252        if (want_color(o->use_color)) {
2253                struct diff_words_style *st = ecbdata->diff_words->style;
2254                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2255                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2256                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2257        }
2258}
2259
2260static void free_diff_words_data(struct emit_callback *ecbdata)
2261{
2262        if (ecbdata->diff_words) {
2263                diff_words_flush(ecbdata);
2264                free (ecbdata->diff_words->opt->emitted_symbols);
2265                free (ecbdata->diff_words->opt);
2266                free (ecbdata->diff_words->minus.text.ptr);
2267                free (ecbdata->diff_words->minus.orig);
2268                free (ecbdata->diff_words->plus.text.ptr);
2269                free (ecbdata->diff_words->plus.orig);
2270                if (ecbdata->diff_words->word_regex) {
2271                        regfree(ecbdata->diff_words->word_regex);
2272                        free(ecbdata->diff_words->word_regex);
2273                }
2274                FREE_AND_NULL(ecbdata->diff_words);
2275        }
2276}
2277
2278const char *diff_get_color(int diff_use_color, enum color_diff ix)
2279{
2280        if (want_color(diff_use_color))
2281                return diff_colors[ix];
2282        return "";
2283}
2284
2285const char *diff_line_prefix(struct diff_options *opt)
2286{
2287        struct strbuf *msgbuf;
2288        if (!opt->output_prefix)
2289                return "";
2290
2291        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2292        return msgbuf->buf;
2293}
2294
2295static unsigned long sane_truncate_line(char *line, unsigned long len)
2296{
2297        const char *cp;
2298        unsigned long allot;
2299        size_t l = len;
2300
2301        cp = line;
2302        allot = l;
2303        while (0 < l) {
2304                (void) utf8_width(&cp, &l);
2305                if (!cp)
2306                        break; /* truncated in the middle? */
2307        }
2308        return allot - l;
2309}
2310
2311static void find_lno(const char *line, struct emit_callback *ecbdata)
2312{
2313        const char *p;
2314        ecbdata->lno_in_preimage = 0;
2315        ecbdata->lno_in_postimage = 0;
2316        p = strchr(line, '-');
2317        if (!p)
2318                return; /* cannot happen */
2319        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2320        p = strchr(p, '+');
2321        if (!p)
2322                return; /* cannot happen */
2323        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2324}
2325
2326static void fn_out_consume(void *priv, char *line, unsigned long len)
2327{
2328        struct emit_callback *ecbdata = priv;
2329        struct diff_options *o = ecbdata->opt;
2330
2331        o->found_changes = 1;
2332
2333        if (ecbdata->header) {
2334                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2335                                 ecbdata->header->buf, ecbdata->header->len, 0);
2336                strbuf_reset(ecbdata->header);
2337                ecbdata->header = NULL;
2338        }
2339
2340        if (ecbdata->label_path[0]) {
2341                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2342                                 ecbdata->label_path[0],
2343                                 strlen(ecbdata->label_path[0]), 0);
2344                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2345                                 ecbdata->label_path[1],
2346                                 strlen(ecbdata->label_path[1]), 0);
2347                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2348        }
2349
2350        if (diff_suppress_blank_empty
2351            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2352                line[0] = '\n';
2353                len = 1;
2354        }
2355
2356        if (line[0] == '@') {
2357                if (ecbdata->diff_words)
2358                        diff_words_flush(ecbdata);
2359                len = sane_truncate_line(line, len);
2360                find_lno(line, ecbdata);
2361                emit_hunk_header(ecbdata, line, len);
2362                return;
2363        }
2364
2365        if (ecbdata->diff_words) {
2366                enum diff_symbol s =
2367                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2368                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2369                if (line[0] == '-') {
2370                        diff_words_append(line, len,
2371                                          &ecbdata->diff_words->minus);
2372                        return;
2373                } else if (line[0] == '+') {
2374                        diff_words_append(line, len,
2375                                          &ecbdata->diff_words->plus);
2376                        return;
2377                } else if (starts_with(line, "\\ ")) {
2378                        /*
2379                         * Eat the "no newline at eof" marker as if we
2380                         * saw a "+" or "-" line with nothing on it,
2381                         * and return without diff_words_flush() to
2382                         * defer processing. If this is the end of
2383                         * preimage, more "+" lines may come after it.
2384                         */
2385                        return;
2386                }
2387                diff_words_flush(ecbdata);
2388                emit_diff_symbol(o, s, line, len, 0);
2389                return;
2390        }
2391
2392        switch (line[0]) {
2393        case '+':
2394                ecbdata->lno_in_postimage++;
2395                emit_add_line(ecbdata, line + 1, len - 1);
2396                break;
2397        case '-':
2398                ecbdata->lno_in_preimage++;
2399                emit_del_line(ecbdata, line + 1, len - 1);
2400                break;
2401        case ' ':
2402                ecbdata->lno_in_postimage++;
2403                ecbdata->lno_in_preimage++;
2404                emit_context_line(ecbdata, line + 1, len - 1);
2405                break;
2406        default:
2407                /* incomplete line at the end */
2408                ecbdata->lno_in_preimage++;
2409                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2410                                 line, len, 0);
2411                break;
2412        }
2413}
2414
2415static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2416{
2417        const char *old_name = a;
2418        const char *new_name = b;
2419        int pfx_length, sfx_length;
2420        int pfx_adjust_for_slash;
2421        int len_a = strlen(a);
2422        int len_b = strlen(b);
2423        int a_midlen, b_midlen;
2424        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2425        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2426
2427        if (qlen_a || qlen_b) {
2428                quote_c_style(a, name, NULL, 0);
2429                strbuf_addstr(name, " => ");
2430                quote_c_style(b, name, NULL, 0);
2431                return;
2432        }
2433
2434        /* Find common prefix */
2435        pfx_length = 0;
2436        while (*old_name && *new_name && *old_name == *new_name) {
2437                if (*old_name == '/')
2438                        pfx_length = old_name - a + 1;
2439                old_name++;
2440                new_name++;
2441        }
2442
2443        /* Find common suffix */
2444        old_name = a + len_a;
2445        new_name = b + len_b;
2446        sfx_length = 0;
2447        /*
2448         * If there is a common prefix, it must end in a slash.  In
2449         * that case we let this loop run 1 into the prefix to see the
2450         * same slash.
2451         *
2452         * If there is no common prefix, we cannot do this as it would
2453         * underrun the input strings.
2454         */
2455        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2456        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2457               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2458               *old_name == *new_name) {
2459                if (*old_name == '/')
2460                        sfx_length = len_a - (old_name - a);
2461                old_name--;
2462                new_name--;
2463        }
2464
2465        /*
2466         * pfx{mid-a => mid-b}sfx
2467         * {pfx-a => pfx-b}sfx
2468         * pfx{sfx-a => sfx-b}
2469         * name-a => name-b
2470         */
2471        a_midlen = len_a - pfx_length - sfx_length;
2472        b_midlen = len_b - pfx_length - sfx_length;
2473        if (a_midlen < 0)
2474                a_midlen = 0;
2475        if (b_midlen < 0)
2476                b_midlen = 0;
2477
2478        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2479        if (pfx_length + sfx_length) {
2480                strbuf_add(name, a, pfx_length);
2481                strbuf_addch(name, '{');
2482        }
2483        strbuf_add(name, a + pfx_length, a_midlen);
2484        strbuf_addstr(name, " => ");
2485        strbuf_add(name, b + pfx_length, b_midlen);
2486        if (pfx_length + sfx_length) {
2487                strbuf_addch(name, '}');
2488                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2489        }
2490}
2491
2492struct diffstat_t {
2493        int nr;
2494        int alloc;
2495        struct diffstat_file {
2496                char *from_name;
2497                char *name;
2498                char *print_name;
2499                const char *comments;
2500                unsigned is_unmerged:1;
2501                unsigned is_binary:1;
2502                unsigned is_renamed:1;
2503                unsigned is_interesting:1;
2504                uintmax_t added, deleted;
2505        } **files;
2506};
2507
2508static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2509                                          const char *name_a,
2510                                          const char *name_b)
2511{
2512        struct diffstat_file *x;
2513        x = xcalloc(1, sizeof(*x));
2514        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2515        diffstat->files[diffstat->nr++] = x;
2516        if (name_b) {
2517                x->from_name = xstrdup(name_a);
2518                x->name = xstrdup(name_b);
2519                x->is_renamed = 1;
2520        }
2521        else {
2522                x->from_name = NULL;
2523                x->name = xstrdup(name_a);
2524        }
2525        return x;
2526}
2527
2528static void diffstat_consume(void *priv, char *line, unsigned long len)
2529{
2530        struct diffstat_t *diffstat = priv;
2531        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2532
2533        if (line[0] == '+')
2534                x->added++;
2535        else if (line[0] == '-')
2536                x->deleted++;
2537}
2538
2539const char mime_boundary_leader[] = "------------";
2540
2541static int scale_linear(int it, int width, int max_change)
2542{
2543        if (!it)
2544                return 0;
2545        /*
2546         * make sure that at least one '-' or '+' is printed if
2547         * there is any change to this path. The easiest way is to
2548         * scale linearly as if the alloted width is one column shorter
2549         * than it is, and then add 1 to the result.
2550         */
2551        return 1 + (it * (width - 1) / max_change);
2552}
2553
2554static void show_graph(struct strbuf *out, char ch, int cnt,
2555                       const char *set, const char *reset)
2556{
2557        if (cnt <= 0)
2558                return;
2559        strbuf_addstr(out, set);
2560        strbuf_addchars(out, ch, cnt);
2561        strbuf_addstr(out, reset);
2562}
2563
2564static void fill_print_name(struct diffstat_file *file)
2565{
2566        struct strbuf pname = STRBUF_INIT;
2567
2568        if (file->print_name)
2569                return;
2570
2571        if (file->is_renamed)
2572                pprint_rename(&pname, file->from_name, file->name);
2573        else
2574                quote_c_style(file->name, &pname, NULL, 0);
2575
2576        if (file->comments)
2577                strbuf_addf(&pname, " (%s)", file->comments);
2578
2579        file->print_name = strbuf_detach(&pname, NULL);
2580}
2581
2582static void print_stat_summary_inserts_deletes(struct diff_options *options,
2583                int files, int insertions, int deletions)
2584{
2585        struct strbuf sb = STRBUF_INIT;
2586
2587        if (!files) {
2588                assert(insertions == 0 && deletions == 0);
2589                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2590                                 NULL, 0, 0);
2591                return;
2592        }
2593
2594        strbuf_addf(&sb,
2595                    (files == 1) ? " %d file changed" : " %d files changed",
2596                    files);
2597
2598        /*
2599         * For binary diff, the caller may want to print "x files
2600         * changed" with insertions == 0 && deletions == 0.
2601         *
2602         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2603         * is probably less confusing (i.e skip over "2 files changed
2604         * but nothing about added/removed lines? Is this a bug in Git?").
2605         */
2606        if (insertions || deletions == 0) {
2607                strbuf_addf(&sb,
2608                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2609                            insertions);
2610        }
2611
2612        if (deletions || insertions == 0) {
2613                strbuf_addf(&sb,
2614                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2615                            deletions);
2616        }
2617        strbuf_addch(&sb, '\n');
2618        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2619                         sb.buf, sb.len, 0);
2620        strbuf_release(&sb);
2621}
2622
2623void print_stat_summary(FILE *fp, int files,
2624                        int insertions, int deletions)
2625{
2626        struct diff_options o;
2627        memset(&o, 0, sizeof(o));
2628        o.file = fp;
2629
2630        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2631}
2632
2633static void show_stats(struct diffstat_t *data, struct diff_options *options)
2634{
2635        int i, len, add, del, adds = 0, dels = 0;
2636        uintmax_t max_change = 0, max_len = 0;
2637        int total_files = data->nr, count;
2638        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2639        const char *reset, *add_c, *del_c;
2640        int extra_shown = 0;
2641        const char *line_prefix = diff_line_prefix(options);
2642        struct strbuf out = STRBUF_INIT;
2643
2644        if (data->nr == 0)
2645                return;
2646
2647        count = options->stat_count ? options->stat_count : data->nr;
2648
2649        reset = diff_get_color_opt(options, DIFF_RESET);
2650        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2651        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2652
2653        /*
2654         * Find the longest filename and max number of changes
2655         */
2656        for (i = 0; (i < count) && (i < data->nr); i++) {
2657                struct diffstat_file *file = data->files[i];
2658                uintmax_t change = file->added + file->deleted;
2659
2660                if (!file->is_interesting && (change == 0)) {
2661                        count++; /* not shown == room for one more */
2662                        continue;
2663                }
2664                fill_print_name(file);
2665                len = strlen(file->print_name);
2666                if (max_len < len)
2667                        max_len = len;
2668
2669                if (file->is_unmerged) {
2670                        /* "Unmerged" is 8 characters */
2671                        bin_width = bin_width < 8 ? 8 : bin_width;
2672                        continue;
2673                }
2674                if (file->is_binary) {
2675                        /* "Bin XXX -> YYY bytes" */
2676                        int w = 14 + decimal_width(file->added)
2677                                + decimal_width(file->deleted);
2678                        bin_width = bin_width < w ? w : bin_width;
2679                        /* Display change counts aligned with "Bin" */
2680                        number_width = 3;
2681                        continue;
2682                }
2683
2684                if (max_change < change)
2685                        max_change = change;
2686        }
2687        count = i; /* where we can stop scanning in data->files[] */
2688
2689        /*
2690         * We have width = stat_width or term_columns() columns total.
2691         * We want a maximum of min(max_len, stat_name_width) for the name part.
2692         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2693         * We also need 1 for " " and 4 + decimal_width(max_change)
2694         * for " | NNNN " and one the empty column at the end, altogether
2695         * 6 + decimal_width(max_change).
2696         *
2697         * If there's not enough space, we will use the smaller of
2698         * stat_name_width (if set) and 5/8*width for the filename,
2699         * and the rest for constant elements + graph part, but no more
2700         * than stat_graph_width for the graph part.
2701         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2702         * for the standard terminal size).
2703         *
2704         * In other words: stat_width limits the maximum width, and
2705         * stat_name_width fixes the maximum width of the filename,
2706         * and is also used to divide available columns if there
2707         * aren't enough.
2708         *
2709         * Binary files are displayed with "Bin XXX -> YYY bytes"
2710         * instead of the change count and graph. This part is treated
2711         * similarly to the graph part, except that it is not
2712         * "scaled". If total width is too small to accommodate the
2713         * guaranteed minimum width of the filename part and the
2714         * separators and this message, this message will "overflow"
2715         * making the line longer than the maximum width.
2716         */
2717
2718        if (options->stat_width == -1)
2719                width = term_columns() - strlen(line_prefix);
2720        else
2721                width = options->stat_width ? options->stat_width : 80;
2722        number_width = decimal_width(max_change) > number_width ?
2723                decimal_width(max_change) : number_width;
2724
2725        if (options->stat_graph_width == -1)
2726                options->stat_graph_width = diff_stat_graph_width;
2727
2728        /*
2729         * Guarantee 3/8*16==6 for the graph part
2730         * and 5/8*16==10 for the filename part
2731         */
2732        if (width < 16 + 6 + number_width)
2733                width = 16 + 6 + number_width;
2734
2735        /*
2736         * First assign sizes that are wanted, ignoring available width.
2737         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2738         * starting from "XXX" should fit in graph_width.
2739         */
2740        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2741        if (options->stat_graph_width &&
2742            options->stat_graph_width < graph_width)
2743                graph_width = options->stat_graph_width;
2744
2745        name_width = (options->stat_name_width > 0 &&
2746                      options->stat_name_width < max_len) ?
2747                options->stat_name_width : max_len;
2748
2749        /*
2750         * Adjust adjustable widths not to exceed maximum width
2751         */
2752        if (name_width + number_width + 6 + graph_width > width) {
2753                if (graph_width > width * 3/8 - number_width - 6) {
2754                        graph_width = width * 3/8 - number_width - 6;
2755                        if (graph_width < 6)
2756                                graph_width = 6;
2757                }
2758
2759                if (options->stat_graph_width &&
2760                    graph_width > options->stat_graph_width)
2761                        graph_width = options->stat_graph_width;
2762                if (name_width > width - number_width - 6 - graph_width)
2763                        name_width = width - number_width - 6 - graph_width;
2764                else
2765                        graph_width = width - number_width - 6 - name_width;
2766        }
2767
2768        /*
2769         * From here name_width is the width of the name area,
2770         * and graph_width is the width of the graph area.
2771         * max_change is used to scale graph properly.
2772         */
2773        for (i = 0; i < count; i++) {
2774                const char *prefix = "";
2775                struct diffstat_file *file = data->files[i];
2776                char *name = file->print_name;
2777                uintmax_t added = file->added;
2778                uintmax_t deleted = file->deleted;
2779                int name_len;
2780
2781                if (!file->is_interesting && (added + deleted == 0))
2782                        continue;
2783
2784                /*
2785                 * "scale" the filename
2786                 */
2787                len = name_width;
2788                name_len = strlen(name);
2789                if (name_width < name_len) {
2790                        char *slash;
2791                        prefix = "...";
2792                        len -= 3;
2793                        name += name_len - len;
2794                        slash = strchr(name, '/');
2795                        if (slash)
2796                                name = slash;
2797                }
2798
2799                if (file->is_binary) {
2800                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2801                        strbuf_addf(&out, " %*s", number_width, "Bin");
2802                        if (!added && !deleted) {
2803                                strbuf_addch(&out, '\n');
2804                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2805                                                 out.buf, out.len, 0);
2806                                strbuf_reset(&out);
2807                                continue;
2808                        }
2809                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2810                                del_c, deleted, reset);
2811                        strbuf_addstr(&out, " -> ");
2812                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2813                                add_c, added, reset);
2814                        strbuf_addstr(&out, " bytes\n");
2815                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2816                                         out.buf, out.len, 0);
2817                        strbuf_reset(&out);
2818                        continue;
2819                }
2820                else if (file->is_unmerged) {
2821                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2822                        strbuf_addstr(&out, " Unmerged\n");
2823                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2824                                         out.buf, out.len, 0);
2825                        strbuf_reset(&out);
2826                        continue;
2827                }
2828
2829                /*
2830                 * scale the add/delete
2831                 */
2832                add = added;
2833                del = deleted;
2834
2835                if (graph_width <= max_change) {
2836                        int total = scale_linear(add + del, graph_width, max_change);
2837                        if (total < 2 && add && del)
2838                                /* width >= 2 due to the sanity check */
2839                                total = 2;
2840                        if (add < del) {
2841                                add = scale_linear(add, graph_width, max_change);
2842                                del = total - add;
2843                        } else {
2844                                del = scale_linear(del, graph_width, max_change);
2845                                add = total - del;
2846                        }
2847                }
2848                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2849                strbuf_addf(&out, " %*"PRIuMAX"%s",
2850                        number_width, added + deleted,
2851                        added + deleted ? " " : "");
2852                show_graph(&out, '+', add, add_c, reset);
2853                show_graph(&out, '-', del, del_c, reset);
2854                strbuf_addch(&out, '\n');
2855                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2856                                 out.buf, out.len, 0);
2857                strbuf_reset(&out);
2858        }
2859
2860        for (i = 0; i < data->nr; i++) {
2861                struct diffstat_file *file = data->files[i];
2862                uintmax_t added = file->added;
2863                uintmax_t deleted = file->deleted;
2864
2865                if (file->is_unmerged ||
2866                    (!file->is_interesting && (added + deleted == 0))) {
2867                        total_files--;
2868                        continue;
2869                }
2870
2871                if (!file->is_binary) {
2872                        adds += added;
2873                        dels += deleted;
2874                }
2875                if (i < count)
2876                        continue;
2877                if (!extra_shown)
2878                        emit_diff_symbol(options,
2879                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2880                                         NULL, 0, 0);
2881                extra_shown = 1;
2882        }
2883
2884        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2885        strbuf_release(&out);
2886}
2887
2888static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2889{
2890        int i, adds = 0, dels = 0, total_files = data->nr;
2891
2892        if (data->nr == 0)
2893                return;
2894
2895        for (i = 0; i < data->nr; i++) {
2896                int added = data->files[i]->added;
2897                int deleted = data->files[i]->deleted;
2898
2899                if (data->files[i]->is_unmerged ||
2900                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2901                        total_files--;
2902                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2903                        adds += added;
2904                        dels += deleted;
2905                }
2906        }
2907        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2908}
2909
2910static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2911{
2912        int i;
2913
2914        if (data->nr == 0)
2915                return;
2916
2917        for (i = 0; i < data->nr; i++) {
2918                struct diffstat_file *file = data->files[i];
2919
2920                fprintf(options->file, "%s", diff_line_prefix(options));
2921
2922                if (file->is_binary)
2923                        fprintf(options->file, "-\t-\t");
2924                else
2925                        fprintf(options->file,
2926                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2927                                file->added, file->deleted);
2928                if (options->line_termination) {
2929                        fill_print_name(file);
2930                        if (!file->is_renamed)
2931                                write_name_quoted(file->name, options->file,
2932                                                  options->line_termination);
2933                        else {
2934                                fputs(file->print_name, options->file);
2935                                putc(options->line_termination, options->file);
2936                        }
2937                } else {
2938                        if (file->is_renamed) {
2939                                putc('\0', options->file);
2940                                write_name_quoted(file->from_name, options->file, '\0');
2941                        }
2942                        write_name_quoted(file->name, options->file, '\0');
2943                }
2944        }
2945}
2946
2947struct dirstat_file {
2948        const char *name;
2949        unsigned long changed;
2950};
2951
2952struct dirstat_dir {
2953        struct dirstat_file *files;
2954        int alloc, nr, permille, cumulative;
2955};
2956
2957static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2958                unsigned long changed, const char *base, int baselen)
2959{
2960        unsigned long sum_changes = 0;
2961        unsigned int sources = 0;
2962        const char *line_prefix = diff_line_prefix(opt);
2963
2964        while (dir->nr) {
2965                struct dirstat_file *f = dir->files;
2966                int namelen = strlen(f->name);
2967                unsigned long changes;
2968                char *slash;
2969
2970                if (namelen < baselen)
2971                        break;
2972                if (memcmp(f->name, base, baselen))
2973                        break;
2974                slash = strchr(f->name + baselen, '/');
2975                if (slash) {
2976                        int newbaselen = slash + 1 - f->name;
2977                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2978                        sources++;
2979                } else {
2980                        changes = f->changed;
2981                        dir->files++;
2982                        dir->nr--;
2983                        sources += 2;
2984                }
2985                sum_changes += changes;
2986        }
2987
2988        /*
2989         * We don't report dirstat's for
2990         *  - the top level
2991         *  - or cases where everything came from a single directory
2992         *    under this directory (sources == 1).
2993         */
2994        if (baselen && sources != 1) {
2995                if (sum_changes) {
2996                        int permille = sum_changes * 1000 / changed;
2997                        if (permille >= dir->permille) {
2998                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2999                                        permille / 10, permille % 10, baselen, base);
3000                                if (!dir->cumulative)
3001                                        return 0;
3002                        }
3003                }
3004        }
3005        return sum_changes;
3006}
3007
3008static int dirstat_compare(const void *_a, const void *_b)
3009{
3010        const struct dirstat_file *a = _a;
3011        const struct dirstat_file *b = _b;
3012        return strcmp(a->name, b->name);
3013}
3014
3015static void show_dirstat(struct diff_options *options)
3016{
3017        int i;
3018        unsigned long changed;
3019        struct dirstat_dir dir;
3020        struct diff_queue_struct *q = &diff_queued_diff;
3021
3022        dir.files = NULL;
3023        dir.alloc = 0;
3024        dir.nr = 0;
3025        dir.permille = options->dirstat_permille;
3026        dir.cumulative = options->flags.dirstat_cumulative;
3027
3028        changed = 0;
3029        for (i = 0; i < q->nr; i++) {
3030                struct diff_filepair *p = q->queue[i];
3031                const char *name;
3032                unsigned long copied, added, damage;
3033
3034                name = p->two->path ? p->two->path : p->one->path;
3035
3036                if (p->one->oid_valid && p->two->oid_valid &&
3037                    oideq(&p->one->oid, &p->two->oid)) {
3038                        /*
3039                         * The SHA1 has not changed, so pre-/post-content is
3040                         * identical. We can therefore skip looking at the
3041                         * file contents altogether.
3042                         */
3043                        damage = 0;
3044                        goto found_damage;
3045                }
3046
3047                if (options->flags.dirstat_by_file) {
3048                        /*
3049                         * In --dirstat-by-file mode, we don't really need to
3050                         * look at the actual file contents at all.
3051                         * The fact that the SHA1 changed is enough for us to
3052                         * add this file to the list of results
3053                         * (with each file contributing equal damage).
3054                         */
3055                        damage = 1;
3056                        goto found_damage;
3057                }
3058
3059                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
3060                        diff_populate_filespec(options->repo, p->one, 0);
3061                        diff_populate_filespec(options->repo, p->two, 0);
3062                        diffcore_count_changes(options->repo,
3063                                               p->one, p->two, NULL, NULL,
3064                                               &copied, &added);
3065                        diff_free_filespec_data(p->one);
3066                        diff_free_filespec_data(p->two);
3067                } else if (DIFF_FILE_VALID(p->one)) {
3068                        diff_populate_filespec(options->repo, p->one, CHECK_SIZE_ONLY);
3069                        copied = added = 0;
3070                        diff_free_filespec_data(p->one);
3071                } else if (DIFF_FILE_VALID(p->two)) {
3072                        diff_populate_filespec(options->repo, p->two, CHECK_SIZE_ONLY);
3073                        copied = 0;
3074                        added = p->two->size;
3075                        diff_free_filespec_data(p->two);
3076                } else
3077                        continue;
3078
3079                /*
3080                 * Original minus copied is the removed material,
3081                 * added is the new material.  They are both damages
3082                 * made to the preimage.
3083                 * If the resulting damage is zero, we know that
3084                 * diffcore_count_changes() considers the two entries to
3085                 * be identical, but since the oid changed, we
3086                 * know that there must have been _some_ kind of change,
3087                 * so we force all entries to have damage > 0.
3088                 */
3089                damage = (p->one->size - copied) + added;
3090                if (!damage)
3091                        damage = 1;
3092
3093found_damage:
3094                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3095                dir.files[dir.nr].name = name;
3096                dir.files[dir.nr].changed = damage;
3097                changed += damage;
3098                dir.nr++;
3099        }
3100
3101        /* This can happen even with many files, if everything was renames */
3102        if (!changed)
3103                return;
3104
3105        /* Show all directories with more than x% of the changes */
3106        QSORT(dir.files, dir.nr, dirstat_compare);
3107        gather_dirstat(options, &dir, changed, "", 0);
3108}
3109
3110static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
3111{
3112        int i;
3113        unsigned long changed;
3114        struct dirstat_dir dir;
3115
3116        if (data->nr == 0)
3117                return;
3118
3119        dir.files = NULL;
3120        dir.alloc = 0;
3121        dir.nr = 0;
3122        dir.permille = options->dirstat_permille;
3123        dir.cumulative = options->flags.dirstat_cumulative;
3124
3125        changed = 0;
3126        for (i = 0; i < data->nr; i++) {
3127                struct diffstat_file *file = data->files[i];
3128                unsigned long damage = file->added + file->deleted;
3129                if (file->is_binary)
3130                        /*
3131                         * binary files counts bytes, not lines. Must find some
3132                         * way to normalize binary bytes vs. textual lines.
3133                         * The following heuristic assumes that there are 64
3134                         * bytes per "line".
3135                         * This is stupid and ugly, but very cheap...
3136                         */
3137                        damage = DIV_ROUND_UP(damage, 64);
3138                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3139                dir.files[dir.nr].name = file->name;
3140                dir.files[dir.nr].changed = damage;
3141                changed += damage;
3142                dir.nr++;
3143        }
3144
3145        /* This can happen even with many files, if everything was renames */
3146        if (!changed)
3147                return;
3148
3149        /* Show all directories with more than x% of the changes */
3150        QSORT(dir.files, dir.nr, dirstat_compare);
3151        gather_dirstat(options, &dir, changed, "", 0);
3152}
3153
3154static void free_diffstat_info(struct diffstat_t *diffstat)
3155{
3156        int i;
3157        for (i = 0; i < diffstat->nr; i++) {
3158                struct diffstat_file *f = diffstat->files[i];
3159                free(f->print_name);
3160                free(f->name);
3161                free(f->from_name);
3162                free(f);
3163        }
3164        free(diffstat->files);
3165}
3166
3167struct checkdiff_t {
3168        const char *filename;
3169        int lineno;
3170        int conflict_marker_size;
3171        struct diff_options *o;
3172        unsigned ws_rule;
3173        unsigned status;
3174};
3175
3176static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3177{
3178        char firstchar;
3179        int cnt;
3180
3181        if (len < marker_size + 1)
3182                return 0;
3183        firstchar = line[0];
3184        switch (firstchar) {
3185        case '=': case '>': case '<': case '|':
3186                break;
3187        default:
3188                return 0;
3189        }
3190        for (cnt = 1; cnt < marker_size; cnt++)
3191                if (line[cnt] != firstchar)
3192                        return 0;
3193        /* line[1] thru line[marker_size-1] are same as firstchar */
3194        if (len < marker_size + 1 || !isspace(line[marker_size]))
3195                return 0;
3196        return 1;
3197}
3198
3199static void checkdiff_consume_hunk(void *priv,
3200                                   long ob, long on, long nb, long nn,
3201                                   const char *func, long funclen)
3202
3203{
3204        struct checkdiff_t *data = priv;
3205        data->lineno = nb - 1;
3206}
3207
3208static void checkdiff_consume(void *priv, char *line, unsigned long len)
3209{
3210        struct checkdiff_t *data = priv;
3211        int marker_size = data->conflict_marker_size;
3212        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3213        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3214        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3215        char *err;
3216        const char *line_prefix;
3217
3218        assert(data->o);
3219        line_prefix = diff_line_prefix(data->o);
3220
3221        if (line[0] == '+') {
3222                unsigned bad;
3223                data->lineno++;
3224                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3225                        data->status |= 1;
3226                        fprintf(data->o->file,
3227                                "%s%s:%d: leftover conflict marker\n",
3228                                line_prefix, data->filename, data->lineno);
3229                }
3230                bad = ws_check(line + 1, len - 1, data->ws_rule);
3231                if (!bad)
3232                        return;
3233                data->status |= bad;
3234                err = whitespace_error_string(bad);
3235                fprintf(data->o->file, "%s%s:%d: %s.\n",
3236                        line_prefix, data->filename, data->lineno, err);
3237                free(err);
3238                emit_line(data->o, set, reset, line, 1);
3239                ws_check_emit(line + 1, len - 1, data->ws_rule,
3240                              data->o->file, set, reset, ws);
3241        } else if (line[0] == ' ') {
3242                data->lineno++;
3243        }
3244}
3245
3246static unsigned char *deflate_it(char *data,
3247                                 unsigned long size,
3248                                 unsigned long *result_size)
3249{
3250        int bound;
3251        unsigned char *deflated;
3252        git_zstream stream;
3253
3254        git_deflate_init(&stream, zlib_compression_level);
3255        bound = git_deflate_bound(&stream, size);
3256        deflated = xmalloc(bound);
3257        stream.next_out = deflated;
3258        stream.avail_out = bound;
3259
3260        stream.next_in = (unsigned char *)data;
3261        stream.avail_in = size;
3262        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3263                ; /* nothing */
3264        git_deflate_end(&stream);
3265        *result_size = stream.total_out;
3266        return deflated;
3267}
3268
3269static void emit_binary_diff_body(struct diff_options *o,
3270                                  mmfile_t *one, mmfile_t *two)
3271{
3272        void *cp;
3273        void *delta;
3274        void *deflated;
3275        void *data;
3276        unsigned long orig_size;
3277        unsigned long delta_size;
3278        unsigned long deflate_size;
3279        unsigned long data_size;
3280
3281        /* We could do deflated delta, or we could do just deflated two,
3282         * whichever is smaller.
3283         */
3284        delta = NULL;
3285        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3286        if (one->size && two->size) {
3287                delta = diff_delta(one->ptr, one->size,
3288                                   two->ptr, two->size,
3289                                   &delta_size, deflate_size);
3290                if (delta) {
3291                        void *to_free = delta;
3292                        orig_size = delta_size;
3293                        delta = deflate_it(delta, delta_size, &delta_size);
3294                        free(to_free);
3295                }
3296        }
3297
3298        if (delta && delta_size < deflate_size) {
3299                char *s = xstrfmt("%"PRIuMAX , (uintmax_t)orig_size);
3300                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3301                                 s, strlen(s), 0);
3302                free(s);
3303                free(deflated);
3304                data = delta;
3305                data_size = delta_size;
3306        } else {
3307                char *s = xstrfmt("%lu", two->size);
3308                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3309                                 s, strlen(s), 0);
3310                free(s);
3311                free(delta);
3312                data = deflated;
3313                data_size = deflate_size;
3314        }
3315
3316        /* emit data encoded in base85 */
3317        cp = data;
3318        while (data_size) {
3319                int len;
3320                int bytes = (52 < data_size) ? 52 : data_size;
3321                char line[71];
3322                data_size -= bytes;
3323                if (bytes <= 26)
3324                        line[0] = bytes + 'A' - 1;
3325                else
3326                        line[0] = bytes - 26 + 'a' - 1;
3327                encode_85(line + 1, cp, bytes);
3328                cp = (char *) cp + bytes;
3329
3330                len = strlen(line);
3331                line[len++] = '\n';
3332                line[len] = '\0';
3333
3334                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3335                                 line, len, 0);
3336        }
3337        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3338        free(data);
3339}
3340
3341static void emit_binary_diff(struct diff_options *o,
3342                             mmfile_t *one, mmfile_t *two)
3343{
3344        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3345        emit_binary_diff_body(o, one, two);
3346        emit_binary_diff_body(o, two, one);
3347}
3348
3349int diff_filespec_is_binary(struct repository *r,
3350                            struct diff_filespec *one)
3351{
3352        if (one->is_binary == -1) {
3353                diff_filespec_load_driver(one, r->index);
3354                if (one->driver->binary != -1)
3355                        one->is_binary = one->driver->binary;
3356                else {
3357                        if (!one->data && DIFF_FILE_VALID(one))
3358                                diff_populate_filespec(r, one, CHECK_BINARY);
3359                        if (one->is_binary == -1 && one->data)
3360                                one->is_binary = buffer_is_binary(one->data,
3361                                                one->size);
3362                        if (one->is_binary == -1)
3363                                one->is_binary = 0;
3364                }
3365        }
3366        return one->is_binary;
3367}
3368
3369static const struct userdiff_funcname *
3370diff_funcname_pattern(struct diff_options *o, struct diff_filespec *one)
3371{
3372        diff_filespec_load_driver(one, o->repo->index);
3373        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3374}
3375
3376void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3377{
3378        if (!options->a_prefix)
3379                options->a_prefix = a;
3380        if (!options->b_prefix)
3381                options->b_prefix = b;
3382}
3383
3384struct userdiff_driver *get_textconv(struct repository *r,
3385                                     struct diff_filespec *one)
3386{
3387        if (!DIFF_FILE_VALID(one))
3388                return NULL;
3389
3390        diff_filespec_load_driver(one, r->index);
3391        return userdiff_get_textconv(r, one->driver);
3392}
3393
3394static void builtin_diff(const char *name_a,
3395                         const char *name_b,
3396                         struct diff_filespec *one,
3397                         struct diff_filespec *two,
3398                         const char *xfrm_msg,
3399                         int must_show_header,
3400                         struct diff_options *o,
3401                         int complete_rewrite)
3402{
3403        mmfile_t mf1, mf2;
3404        const char *lbl[2];
3405        char *a_one, *b_two;
3406        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3407        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3408        const char *a_prefix, *b_prefix;
3409        struct userdiff_driver *textconv_one = NULL;
3410        struct userdiff_driver *textconv_two = NULL;
3411        struct strbuf header = STRBUF_INIT;
3412        const char *line_prefix = diff_line_prefix(o);
3413
3414        diff_set_mnemonic_prefix(o, "a/", "b/");
3415        if (o->flags.reverse_diff) {
3416                a_prefix = o->b_prefix;
3417                b_prefix = o->a_prefix;
3418        } else {
3419                a_prefix = o->a_prefix;
3420                b_prefix = o->b_prefix;
3421        }
3422
3423        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3424            (!one->mode || S_ISGITLINK(one->mode)) &&
3425            (!two->mode || S_ISGITLINK(two->mode))) {
3426                show_submodule_summary(o, one->path ? one->path : two->path,
3427                                &one->oid, &two->oid,
3428                                two->dirty_submodule);
3429                return;
3430        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3431                   (!one->mode || S_ISGITLINK(one->mode)) &&
3432                   (!two->mode || S_ISGITLINK(two->mode))) {
3433                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3434                                &one->oid, &two->oid,
3435                                two->dirty_submodule);
3436                return;
3437        }
3438
3439        if (o->flags.allow_textconv) {
3440                textconv_one = get_textconv(o->repo, one);
3441                textconv_two = get_textconv(o->repo, two);
3442        }
3443
3444        /* Never use a non-valid filename anywhere if at all possible */
3445        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3446        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3447
3448        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3449        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3450        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3451        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3452        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3453        if (lbl[0][0] == '/') {
3454                /* /dev/null */
3455                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3456                if (xfrm_msg)
3457                        strbuf_addstr(&header, xfrm_msg);
3458                must_show_header = 1;
3459        }
3460        else if (lbl[1][0] == '/') {
3461                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3462                if (xfrm_msg)
3463                        strbuf_addstr(&header, xfrm_msg);
3464                must_show_header = 1;
3465        }
3466        else {
3467                if (one->mode != two->mode) {
3468                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3469                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3470                        must_show_header = 1;
3471                }
3472                if (xfrm_msg)
3473                        strbuf_addstr(&header, xfrm_msg);
3474
3475                /*
3476                 * we do not run diff between different kind
3477                 * of objects.
3478                 */
3479                if ((one->mode ^ two->mode) & S_IFMT)
3480                        goto free_ab_and_return;
3481                if (complete_rewrite &&
3482                    (textconv_one || !diff_filespec_is_binary(o->repo, one)) &&
3483                    (textconv_two || !diff_filespec_is_binary(o->repo, two))) {
3484                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3485                                         header.buf, header.len, 0);
3486                        strbuf_reset(&header);
3487                        emit_rewrite_diff(name_a, name_b, one, two,
3488                                          textconv_one, textconv_two, o);
3489                        o->found_changes = 1;
3490                        goto free_ab_and_return;
3491                }
3492        }
3493
3494        if (o->irreversible_delete && lbl[1][0] == '/') {
3495                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3496                                 header.len, 0);
3497                strbuf_reset(&header);
3498                goto free_ab_and_return;
3499        } else if (!o->flags.text &&
3500                   ( (!textconv_one && diff_filespec_is_binary(o->repo, one)) ||
3501                     (!textconv_two && diff_filespec_is_binary(o->repo, two)) )) {
3502                struct strbuf sb = STRBUF_INIT;
3503                if (!one->data && !two->data &&
3504                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3505                    !o->flags.binary) {
3506                        if (oideq(&one->oid, &two->oid)) {
3507                                if (must_show_header)
3508                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3509                                                         header.buf, header.len,
3510                                                         0);
3511                                goto free_ab_and_return;
3512                        }
3513                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3514                                         header.buf, header.len, 0);
3515                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3516                                    diff_line_prefix(o), lbl[0], lbl[1]);
3517                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3518                                         sb.buf, sb.len, 0);
3519                        strbuf_release(&sb);
3520                        goto free_ab_and_return;
3521                }
3522                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3523                    fill_mmfile(o->repo, &mf2, two) < 0)
3524                        die("unable to read files to diff");
3525                /* Quite common confusing case */
3526                if (mf1.size == mf2.size &&
3527                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3528                        if (must_show_header)
3529                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3530                                                 header.buf, header.len, 0);
3531                        goto free_ab_and_return;
3532                }
3533                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3534                strbuf_reset(&header);
3535                if (o->flags.binary)
3536                        emit_binary_diff(o, &mf1, &mf2);
3537                else {
3538                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3539                                    diff_line_prefix(o), lbl[0], lbl[1]);
3540                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3541                                         sb.buf, sb.len, 0);
3542                        strbuf_release(&sb);
3543                }
3544                o->found_changes = 1;
3545        } else {
3546                /* Crazy xdl interfaces.. */
3547                const char *diffopts;
3548                const char *v;
3549                xpparam_t xpp;
3550                xdemitconf_t xecfg;
3551                struct emit_callback ecbdata;
3552                const struct userdiff_funcname *pe;
3553
3554                if (must_show_header) {
3555                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3556                                         header.buf, header.len, 0);
3557                        strbuf_reset(&header);
3558                }
3559
3560                mf1.size = fill_textconv(o->repo, textconv_one, one, &mf1.ptr);
3561                mf2.size = fill_textconv(o->repo, textconv_two, two, &mf2.ptr);
3562
3563                pe = diff_funcname_pattern(o, one);
3564                if (!pe)
3565                        pe = diff_funcname_pattern(o, two);
3566
3567                memset(&xpp, 0, sizeof(xpp));
3568                memset(&xecfg, 0, sizeof(xecfg));
3569                memset(&ecbdata, 0, sizeof(ecbdata));
3570                if (o->flags.suppress_diff_headers)
3571                        lbl[0] = NULL;
3572                ecbdata.label_path = lbl;
3573                ecbdata.color_diff = want_color(o->use_color);
3574                ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
3575                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3576                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3577                ecbdata.opt = o;
3578                if (header.len && !o->flags.suppress_diff_headers)
3579                        ecbdata.header = &header;
3580                xpp.flags = o->xdl_opts;
3581                xpp.anchors = o->anchors;
3582                xpp.anchors_nr = o->anchors_nr;
3583                xecfg.ctxlen = o->context;
3584                xecfg.interhunkctxlen = o->interhunkcontext;
3585                xecfg.flags = XDL_EMIT_FUNCNAMES;
3586                if (o->flags.funccontext)
3587                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3588                if (pe)
3589                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3590
3591                diffopts = getenv("GIT_DIFF_OPTS");
3592                if (!diffopts)
3593                        ;
3594                else if (skip_prefix(diffopts, "--unified=", &v))
3595                        xecfg.ctxlen = strtoul(v, NULL, 10);
3596                else if (skip_prefix(diffopts, "-u", &v))
3597                        xecfg.ctxlen = strtoul(v, NULL, 10);
3598
3599                if (o->word_diff)
3600                        init_diff_words_data(&ecbdata, o, one, two);
3601                if (xdi_diff_outf(&mf1, &mf2, NULL, fn_out_consume,
3602                                  &ecbdata, &xpp, &xecfg))
3603                        die("unable to generate diff for %s", one->path);
3604                if (o->word_diff)
3605                        free_diff_words_data(&ecbdata);
3606                if (textconv_one)
3607                        free(mf1.ptr);
3608                if (textconv_two)
3609                        free(mf2.ptr);
3610                xdiff_clear_find_func(&xecfg);
3611        }
3612
3613 free_ab_and_return:
3614        strbuf_release(&header);
3615        diff_free_filespec_data(one);
3616        diff_free_filespec_data(two);
3617        free(a_one);
3618        free(b_two);
3619        return;
3620}
3621
3622static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3623{
3624        if (!is_renamed) {
3625                if (p->status == DIFF_STATUS_ADDED) {
3626                        if (S_ISLNK(p->two->mode))
3627                                return "new +l";
3628                        else if ((p->two->mode & 0777) == 0755)
3629                                return "new +x";
3630                        else
3631                                return "new";
3632                } else if (p->status == DIFF_STATUS_DELETED)
3633                        return "gone";
3634        }
3635        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3636                return "mode -l";
3637        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3638                return "mode +l";
3639        else if ((p->one->mode & 0777) == 0644 &&
3640                 (p->two->mode & 0777) == 0755)
3641                return "mode +x";
3642        else if ((p->one->mode & 0777) == 0755 &&
3643                 (p->two->mode & 0777) == 0644)
3644                return "mode -x";
3645        return NULL;
3646}
3647
3648static void builtin_diffstat(const char *name_a, const char *name_b,
3649                             struct diff_filespec *one,
3650                             struct diff_filespec *two,
3651                             struct diffstat_t *diffstat,
3652                             struct diff_options *o,
3653                             struct diff_filepair *p)
3654{
3655        mmfile_t mf1, mf2;
3656        struct diffstat_file *data;
3657        int same_contents;
3658        int complete_rewrite = 0;
3659
3660        if (!DIFF_PAIR_UNMERGED(p)) {
3661                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3662                        complete_rewrite = 1;
3663        }
3664
3665        data = diffstat_add(diffstat, name_a, name_b);
3666        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3667        if (o->flags.stat_with_summary)
3668                data->comments = get_compact_summary(p, data->is_renamed);
3669
3670        if (!one || !two) {
3671                data->is_unmerged = 1;
3672                return;
3673        }
3674
3675        same_contents = oideq(&one->oid, &two->oid);
3676
3677        if (diff_filespec_is_binary(o->repo, one) ||
3678            diff_filespec_is_binary(o->repo, two)) {
3679                data->is_binary = 1;
3680                if (same_contents) {
3681                        data->added = 0;
3682                        data->deleted = 0;
3683                } else {
3684                        data->added = diff_filespec_size(o->repo, two);
3685                        data->deleted = diff_filespec_size(o->repo, one);
3686                }
3687        }
3688
3689        else if (complete_rewrite) {
3690                diff_populate_filespec(o->repo, one, 0);
3691                diff_populate_filespec(o->repo, two, 0);
3692                data->deleted = count_lines(one->data, one->size);
3693                data->added = count_lines(two->data, two->size);
3694        }
3695
3696        else if (!same_contents) {
3697                /* Crazy xdl interfaces.. */
3698                xpparam_t xpp;
3699                xdemitconf_t xecfg;
3700
3701                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3702                    fill_mmfile(o->repo, &mf2, two) < 0)
3703                        die("unable to read files to diff");
3704
3705                memset(&xpp, 0, sizeof(xpp));
3706                memset(&xecfg, 0, sizeof(xecfg));
3707                xpp.flags = o->xdl_opts;
3708                xpp.anchors = o->anchors;
3709                xpp.anchors_nr = o->anchors_nr;
3710                xecfg.ctxlen = o->context;
3711                xecfg.interhunkctxlen = o->interhunkcontext;
3712                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
3713                                  diffstat_consume, diffstat, &xpp, &xecfg))
3714                        die("unable to generate diffstat for %s", one->path);
3715        }
3716
3717        diff_free_filespec_data(one);
3718        diff_free_filespec_data(two);
3719}
3720
3721static void builtin_checkdiff(const char *name_a, const char *name_b,
3722                              const char *attr_path,
3723                              struct diff_filespec *one,
3724                              struct diff_filespec *two,
3725                              struct diff_options *o)
3726{
3727        mmfile_t mf1, mf2;
3728        struct checkdiff_t data;
3729
3730        if (!two)
3731                return;
3732
3733        memset(&data, 0, sizeof(data));
3734        data.filename = name_b ? name_b : name_a;
3735        data.lineno = 0;
3736        data.o = o;
3737        data.ws_rule = whitespace_rule(o->repo->index, attr_path);
3738        data.conflict_marker_size = ll_merge_marker_size(o->repo->index, attr_path);
3739
3740        if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3741            fill_mmfile(o->repo, &mf2, two) < 0)
3742                die("unable to read files to diff");
3743
3744        /*
3745         * All the other codepaths check both sides, but not checking
3746         * the "old" side here is deliberate.  We are checking the newly
3747         * introduced changes, and as long as the "new" side is text, we
3748         * can and should check what it introduces.
3749         */
3750        if (diff_filespec_is_binary(o->repo, two))
3751                goto free_and_return;
3752        else {
3753                /* Crazy xdl interfaces.. */
3754                xpparam_t xpp;
3755                xdemitconf_t xecfg;
3756
3757                memset(&xpp, 0, sizeof(xpp));
3758                memset(&xecfg, 0, sizeof(xecfg));
3759                xecfg.ctxlen = 1; /* at least one context line */
3760                xpp.flags = 0;
3761                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume_hunk,
3762                                  checkdiff_consume, &data,
3763                                  &xpp, &xecfg))
3764                        die("unable to generate checkdiff for %s", one->path);
3765
3766                if (data.ws_rule & WS_BLANK_AT_EOF) {
3767                        struct emit_callback ecbdata;
3768                        int blank_at_eof;
3769
3770                        ecbdata.ws_rule = data.ws_rule;
3771                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3772                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3773
3774                        if (blank_at_eof) {
3775                                static char *err;
3776                                if (!err)
3777                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3778                                fprintf(o->file, "%s:%d: %s.\n",
3779                                        data.filename, blank_at_eof, err);
3780                                data.status = 1; /* report errors */
3781                        }
3782                }
3783        }
3784 free_and_return:
3785        diff_free_filespec_data(one);
3786        diff_free_filespec_data(two);
3787        if (data.status)
3788                o->flags.check_failed = 1;
3789}
3790
3791struct diff_filespec *alloc_filespec(const char *path)
3792{
3793        struct diff_filespec *spec;
3794
3795        FLEXPTR_ALLOC_STR(spec, path, path);
3796        spec->count = 1;
3797        spec->is_binary = -1;
3798        return spec;
3799}
3800
3801void free_filespec(struct diff_filespec *spec)
3802{
3803        if (!--spec->count) {
3804                diff_free_filespec_data(spec);
3805                free(spec);
3806        }
3807}
3808
3809void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3810                   int oid_valid, unsigned short mode)
3811{
3812        if (mode) {
3813                spec->mode = canon_mode(mode);
3814                oidcpy(&spec->oid, oid);
3815                spec->oid_valid = oid_valid;
3816        }
3817}
3818
3819/*
3820 * Given a name and sha1 pair, if the index tells us the file in
3821 * the work tree has that object contents, return true, so that
3822 * prepare_temp_file() does not have to inflate and extract.
3823 */
3824static int reuse_worktree_file(struct index_state *istate,
3825                               const char *name,
3826                               const struct object_id *oid,
3827                               int want_file)
3828{
3829        const struct cache_entry *ce;
3830        struct stat st;
3831        int pos, len;
3832
3833        /*
3834         * We do not read the cache ourselves here, because the
3835         * benchmark with my previous version that always reads cache
3836         * shows that it makes things worse for diff-tree comparing
3837         * two linux-2.6 kernel trees in an already checked out work
3838         * tree.  This is because most diff-tree comparisons deal with
3839         * only a small number of files, while reading the cache is
3840         * expensive for a large project, and its cost outweighs the
3841         * savings we get by not inflating the object to a temporary
3842         * file.  Practically, this code only helps when we are used
3843         * by diff-cache --cached, which does read the cache before
3844         * calling us.
3845         */
3846        if (!istate->cache)
3847                return 0;
3848
3849        /* We want to avoid the working directory if our caller
3850         * doesn't need the data in a normal file, this system
3851         * is rather slow with its stat/open/mmap/close syscalls,
3852         * and the object is contained in a pack file.  The pack
3853         * is probably already open and will be faster to obtain
3854         * the data through than the working directory.  Loose
3855         * objects however would tend to be slower as they need
3856         * to be individually opened and inflated.
3857         */
3858        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3859                return 0;
3860
3861        /*
3862         * Similarly, if we'd have to convert the file contents anyway, that
3863         * makes the optimization not worthwhile.
3864         */
3865        if (!want_file && would_convert_to_git(istate, name))
3866                return 0;
3867
3868        len = strlen(name);
3869        pos = index_name_pos(istate, name, len);
3870        if (pos < 0)
3871                return 0;
3872        ce = istate->cache[pos];
3873
3874        /*
3875         * This is not the sha1 we are looking for, or
3876         * unreusable because it is not a regular file.
3877         */
3878        if (!oideq(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3879                return 0;
3880
3881        /*
3882         * If ce is marked as "assume unchanged", there is no
3883         * guarantee that work tree matches what we are looking for.
3884         */
3885        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3886                return 0;
3887
3888        /*
3889         * If ce matches the file in the work tree, we can reuse it.
3890         */
3891        if (ce_uptodate(ce) ||
3892            (!lstat(name, &st) && !ie_match_stat(istate, ce, &st, 0)))
3893                return 1;
3894
3895        return 0;
3896}
3897
3898static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3899{
3900        struct strbuf buf = STRBUF_INIT;
3901        char *dirty = "";
3902
3903        /* Are we looking at the work tree? */
3904        if (s->dirty_submodule)
3905                dirty = "-dirty";
3906
3907        strbuf_addf(&buf, "Subproject commit %s%s\n",
3908                    oid_to_hex(&s->oid), dirty);
3909        s->size = buf.len;
3910        if (size_only) {
3911                s->data = NULL;
3912                strbuf_release(&buf);
3913        } else {
3914                s->data = strbuf_detach(&buf, NULL);
3915                s->should_free = 1;
3916        }
3917        return 0;
3918}
3919
3920/*
3921 * While doing rename detection and pickaxe operation, we may need to
3922 * grab the data for the blob (or file) for our own in-core comparison.
3923 * diff_filespec has data and size fields for this purpose.
3924 */
3925int diff_populate_filespec(struct repository *r,
3926                           struct diff_filespec *s,
3927                           unsigned int flags)
3928{
3929        int size_only = flags & CHECK_SIZE_ONLY;
3930        int err = 0;
3931        int conv_flags = global_conv_flags_eol;
3932        /*
3933         * demote FAIL to WARN to allow inspecting the situation
3934         * instead of refusing.
3935         */
3936        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3937                conv_flags = CONV_EOL_RNDTRP_WARN;
3938
3939        if (!DIFF_FILE_VALID(s))
3940                die("internal error: asking to populate invalid file.");
3941        if (S_ISDIR(s->mode))
3942                return -1;
3943
3944        if (s->data)
3945                return 0;
3946
3947        if (size_only && 0 < s->size)
3948                return 0;
3949
3950        if (S_ISGITLINK(s->mode))
3951                return diff_populate_gitlink(s, size_only);
3952
3953        if (!s->oid_valid ||
3954            reuse_worktree_file(r->index, s->path, &s->oid, 0)) {
3955                struct strbuf buf = STRBUF_INIT;
3956                struct stat st;
3957                int fd;
3958
3959                if (lstat(s->path, &st) < 0) {
3960                err_empty:
3961                        err = -1;
3962                empty:
3963                        s->data = (char *)"";
3964                        s->size = 0;
3965                        return err;
3966                }
3967                s->size = xsize_t(st.st_size);
3968                if (!s->size)
3969                        goto empty;
3970                if (S_ISLNK(st.st_mode)) {
3971                        struct strbuf sb = STRBUF_INIT;
3972
3973                        if (strbuf_readlink(&sb, s->path, s->size))
3974                                goto err_empty;
3975                        s->size = sb.len;
3976                        s->data = strbuf_detach(&sb, NULL);
3977                        s->should_free = 1;
3978                        return 0;
3979                }
3980
3981                /*
3982                 * Even if the caller would be happy with getting
3983                 * only the size, we cannot return early at this
3984                 * point if the path requires us to run the content
3985                 * conversion.
3986                 */
3987                if (size_only && !would_convert_to_git(r->index, s->path))
3988                        return 0;
3989
3990                /*
3991                 * Note: this check uses xsize_t(st.st_size) that may
3992                 * not be the true size of the blob after it goes
3993                 * through convert_to_git().  This may not strictly be
3994                 * correct, but the whole point of big_file_threshold
3995                 * and is_binary check being that we want to avoid
3996                 * opening the file and inspecting the contents, this
3997                 * is probably fine.
3998                 */
3999                if ((flags & CHECK_BINARY) &&
4000                    s->size > big_file_threshold && s->is_binary == -1) {
4001                        s->is_binary = 1;
4002                        return 0;
4003                }
4004                fd = open(s->path, O_RDONLY);
4005                if (fd < 0)
4006                        goto err_empty;
4007                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
4008                close(fd);
4009                s->should_munmap = 1;
4010
4011                /*
4012                 * Convert from working tree format to canonical git format
4013                 */
4014                if (convert_to_git(r->index, s->path, s->data, s->size, &buf, conv_flags)) {
4015                        size_t size = 0;
4016                        munmap(s->data, s->size);
4017                        s->should_munmap = 0;
4018                        s->data = strbuf_detach(&buf, &size);
4019                        s->size = size;
4020                        s->should_free = 1;
4021                }
4022        }
4023        else {
4024                enum object_type type;
4025                if (size_only || (flags & CHECK_BINARY)) {
4026                        type = oid_object_info(r, &s->oid, &s->size);
4027                        if (type < 0)
4028                                die("unable to read %s",
4029                                    oid_to_hex(&s->oid));
4030                        if (size_only)
4031                                return 0;
4032                        if (s->size > big_file_threshold && s->is_binary == -1) {
4033                                s->is_binary = 1;
4034                                return 0;
4035                        }
4036                }
4037                s->data = read_object_file(&s->oid, &type, &s->size);
4038                if (!s->data)
4039                        die("unable to read %s", oid_to_hex(&s->oid));
4040                s->should_free = 1;
4041        }
4042        return 0;
4043}
4044
4045void diff_free_filespec_blob(struct diff_filespec *s)
4046{
4047        if (s->should_free)
4048                free(s->data);
4049        else if (s->should_munmap)
4050                munmap(s->data, s->size);
4051
4052        if (s->should_free || s->should_munmap) {
4053                s->should_free = s->should_munmap = 0;
4054                s->data = NULL;
4055        }
4056}
4057
4058void diff_free_filespec_data(struct diff_filespec *s)
4059{
4060        diff_free_filespec_blob(s);
4061        FREE_AND_NULL(s->cnt_data);
4062}
4063
4064static void prep_temp_blob(struct index_state *istate,
4065                           const char *path, struct diff_tempfile *temp,
4066                           void *blob,
4067                           unsigned long size,
4068                           const struct object_id *oid,
4069                           int mode)
4070{
4071        struct strbuf buf = STRBUF_INIT;
4072        struct strbuf tempfile = STRBUF_INIT;
4073        char *path_dup = xstrdup(path);
4074        const char *base = basename(path_dup);
4075
4076        /* Generate "XXXXXX_basename.ext" */
4077        strbuf_addstr(&tempfile, "XXXXXX_");
4078        strbuf_addstr(&tempfile, base);
4079
4080        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
4081        if (!temp->tempfile)
4082                die_errno("unable to create temp-file");
4083        if (convert_to_working_tree(istate, path,
4084                        (const char *)blob, (size_t)size, &buf)) {
4085                blob = buf.buf;
4086                size = buf.len;
4087        }
4088        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
4089            close_tempfile_gently(temp->tempfile))
4090                die_errno("unable to write temp-file");
4091        temp->name = get_tempfile_path(temp->tempfile);
4092        oid_to_hex_r(temp->hex, oid);
4093        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
4094        strbuf_release(&buf);
4095        strbuf_release(&tempfile);
4096        free(path_dup);
4097}
4098
4099static struct diff_tempfile *prepare_temp_file(struct repository *r,
4100                                               const char *name,
4101                                               struct diff_filespec *one)
4102{
4103        struct diff_tempfile *temp = claim_diff_tempfile();
4104
4105        if (!DIFF_FILE_VALID(one)) {
4106        not_a_valid_file:
4107                /* A '-' entry produces this for file-2, and
4108                 * a '+' entry produces this for file-1.
4109                 */
4110                temp->name = "/dev/null";
4111                xsnprintf(temp->hex, sizeof(temp->hex), ".");
4112                xsnprintf(temp->mode, sizeof(temp->mode), ".");
4113                return temp;
4114        }
4115
4116        if (!S_ISGITLINK(one->mode) &&
4117            (!one->oid_valid ||
4118             reuse_worktree_file(r->index, name, &one->oid, 1))) {
4119                struct stat st;
4120                if (lstat(name, &st) < 0) {
4121                        if (errno == ENOENT)
4122                                goto not_a_valid_file;
4123                        die_errno("stat(%s)", name);
4124                }
4125                if (S_ISLNK(st.st_mode)) {
4126                        struct strbuf sb = STRBUF_INIT;
4127                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
4128                                die_errno("readlink(%s)", name);
4129                        prep_temp_blob(r->index, name, temp, sb.buf, sb.len,
4130                                       (one->oid_valid ?
4131                                        &one->oid : &null_oid),
4132                                       (one->oid_valid ?
4133                                        one->mode : S_IFLNK));
4134                        strbuf_release(&sb);
4135                }
4136                else {
4137                        /* we can borrow from the file in the work tree */
4138                        temp->name = name;
4139                        if (!one->oid_valid)
4140                                oid_to_hex_r(temp->hex, &null_oid);
4141                        else
4142                                oid_to_hex_r(temp->hex, &one->oid);
4143                        /* Even though we may sometimes borrow the
4144                         * contents from the work tree, we always want
4145                         * one->mode.  mode is trustworthy even when
4146                         * !(one->oid_valid), as long as
4147                         * DIFF_FILE_VALID(one).
4148                         */
4149                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
4150                }
4151                return temp;
4152        }
4153        else {
4154                if (diff_populate_filespec(r, one, 0))
4155                        die("cannot read data blob for %s", one->path);
4156                prep_temp_blob(r->index, name, temp,
4157                               one->data, one->size,
4158                               &one->oid, one->mode);
4159        }
4160        return temp;
4161}
4162
4163static void add_external_diff_name(struct repository *r,
4164                                   struct argv_array *argv,
4165                                   const char *name,
4166                                   struct diff_filespec *df)
4167{
4168        struct diff_tempfile *temp = prepare_temp_file(r, name, df);
4169        argv_array_push(argv, temp->name);
4170        argv_array_push(argv, temp->hex);
4171        argv_array_push(argv, temp->mode);
4172}
4173
4174/* An external diff command takes:
4175 *
4176 * diff-cmd name infile1 infile1-sha1 infile1-mode \
4177 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
4178 *
4179 */
4180static void run_external_diff(const char *pgm,
4181                              const char *name,
4182                              const char *other,
4183                              struct diff_filespec *one,
4184                              struct diff_filespec *two,
4185                              const char *xfrm_msg,
4186                              struct diff_options *o)
4187{
4188        struct argv_array argv = ARGV_ARRAY_INIT;
4189        struct argv_array env = ARGV_ARRAY_INIT;
4190        struct diff_queue_struct *q = &diff_queued_diff;
4191
4192        argv_array_push(&argv, pgm);
4193        argv_array_push(&argv, name);
4194
4195        if (one && two) {
4196                add_external_diff_name(o->repo, &argv, name, one);
4197                if (!other)
4198                        add_external_diff_name(o->repo, &argv, name, two);
4199                else {
4200                        add_external_diff_name(o->repo, &argv, other, two);
4201                        argv_array_push(&argv, other);
4202                        argv_array_push(&argv, xfrm_msg);
4203                }
4204        }
4205
4206        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4207        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4208
4209        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4210                die(_("external diff died, stopping at %s"), name);
4211
4212        remove_tempfile();
4213        argv_array_clear(&argv);
4214        argv_array_clear(&env);
4215}
4216
4217static int similarity_index(struct diff_filepair *p)
4218{
4219        return p->score * 100 / MAX_SCORE;
4220}
4221
4222static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4223{
4224        if (startup_info->have_repository)
4225                return find_unique_abbrev(oid, abbrev);
4226        else {
4227                char *hex = oid_to_hex(oid);
4228                if (abbrev < 0)
4229                        abbrev = FALLBACK_DEFAULT_ABBREV;
4230                if (abbrev > the_hash_algo->hexsz)
4231                        BUG("oid abbreviation out of range: %d", abbrev);
4232                if (abbrev)
4233                        hex[abbrev] = '\0';
4234                return hex;
4235        }
4236}
4237
4238static void fill_metainfo(struct strbuf *msg,
4239                          const char *name,
4240                          const char *other,
4241                          struct diff_filespec *one,
4242                          struct diff_filespec *two,
4243                          struct diff_options *o,
4244                          struct diff_filepair *p,
4245                          int *must_show_header,
4246                          int use_color)
4247{
4248        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4249        const char *reset = diff_get_color(use_color, DIFF_RESET);
4250        const char *line_prefix = diff_line_prefix(o);
4251
4252        *must_show_header = 1;
4253        strbuf_init(msg, PATH_MAX * 2 + 300);
4254        switch (p->status) {
4255        case DIFF_STATUS_COPIED:
4256                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4257                            line_prefix, set, similarity_index(p));
4258                strbuf_addf(msg, "%s\n%s%scopy from ",
4259                            reset,  line_prefix, set);
4260                quote_c_style(name, msg, NULL, 0);
4261                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4262                quote_c_style(other, msg, NULL, 0);
4263                strbuf_addf(msg, "%s\n", reset);
4264                break;
4265        case DIFF_STATUS_RENAMED:
4266                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4267                            line_prefix, set, similarity_index(p));
4268                strbuf_addf(msg, "%s\n%s%srename from ",
4269                            reset, line_prefix, set);
4270                quote_c_style(name, msg, NULL, 0);
4271                strbuf_addf(msg, "%s\n%s%srename to ",
4272                            reset, line_prefix, set);
4273                quote_c_style(other, msg, NULL, 0);
4274                strbuf_addf(msg, "%s\n", reset);
4275                break;
4276        case DIFF_STATUS_MODIFIED:
4277                if (p->score) {
4278                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4279                                    line_prefix,
4280                                    set, similarity_index(p), reset);
4281                        break;
4282                }
4283                /* fallthru */
4284        default:
4285                *must_show_header = 0;
4286        }
4287        if (one && two && !oideq(&one->oid, &two->oid)) {
4288                const unsigned hexsz = the_hash_algo->hexsz;
4289                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4290
4291                if (o->flags.binary) {
4292                        mmfile_t mf;
4293                        if ((!fill_mmfile(o->repo, &mf, one) &&
4294                             diff_filespec_is_binary(o->repo, one)) ||
4295                            (!fill_mmfile(o->repo, &mf, two) &&
4296                             diff_filespec_is_binary(o->repo, two)))
4297                                abbrev = hexsz;
4298                }
4299                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4300                            diff_abbrev_oid(&one->oid, abbrev),
4301                            diff_abbrev_oid(&two->oid, abbrev));
4302                if (one->mode == two->mode)
4303                        strbuf_addf(msg, " %06o", one->mode);
4304                strbuf_addf(msg, "%s\n", reset);
4305        }
4306}
4307
4308static void run_diff_cmd(const char *pgm,
4309                         const char *name,
4310                         const char *other,
4311                         const char *attr_path,
4312                         struct diff_filespec *one,
4313                         struct diff_filespec *two,
4314                         struct strbuf *msg,
4315                         struct diff_options *o,
4316                         struct diff_filepair *p)
4317{
4318        const char *xfrm_msg = NULL;
4319        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4320        int must_show_header = 0;
4321
4322
4323        if (o->flags.allow_external) {
4324                struct userdiff_driver *drv;
4325
4326                drv = userdiff_find_by_path(o->repo->index, attr_path);
4327                if (drv && drv->external)
4328                        pgm = drv->external;
4329        }
4330
4331        if (msg) {
4332                /*
4333                 * don't use colors when the header is intended for an
4334                 * external diff driver
4335                 */
4336                fill_metainfo(msg, name, other, one, two, o, p,
4337                              &must_show_header,
4338                              want_color(o->use_color) && !pgm);
4339                xfrm_msg = msg->len ? msg->buf : NULL;
4340        }
4341
4342        if (pgm) {
4343                run_external_diff(pgm, name, other, one, two, xfrm_msg, o);
4344                return;
4345        }
4346        if (one && two)
4347                builtin_diff(name, other ? other : name,
4348                             one, two, xfrm_msg, must_show_header,
4349                             o, complete_rewrite);
4350        else
4351                fprintf(o->file, "* Unmerged path %s\n", name);
4352}
4353
4354static void diff_fill_oid_info(struct diff_filespec *one, struct index_state *istate)
4355{
4356        if (DIFF_FILE_VALID(one)) {
4357                if (!one->oid_valid) {
4358                        struct stat st;
4359                        if (one->is_stdin) {
4360                                oidclr(&one->oid);
4361                                return;
4362                        }
4363                        if (lstat(one->path, &st) < 0)
4364                                die_errno("stat '%s'", one->path);
4365                        if (index_path(istate, &one->oid, one->path, &st, 0))
4366                                die("cannot hash %s", one->path);
4367                }
4368        }
4369        else
4370                oidclr(&one->oid);
4371}
4372
4373static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4374{
4375        /* Strip the prefix but do not molest /dev/null and absolute paths */
4376        if (*namep && !is_absolute_path(*namep)) {
4377                *namep += prefix_length;
4378                if (**namep == '/')
4379                        ++*namep;
4380        }
4381        if (*otherp && !is_absolute_path(*otherp)) {
4382                *otherp += prefix_length;
4383                if (**otherp == '/')
4384                        ++*otherp;
4385        }
4386}
4387
4388static void run_diff(struct diff_filepair *p, struct diff_options *o)
4389{
4390        const char *pgm = external_diff();
4391        struct strbuf msg;
4392        struct diff_filespec *one = p->one;
4393        struct diff_filespec *two = p->two;
4394        const char *name;
4395        const char *other;
4396        const char *attr_path;
4397
4398        name  = one->path;
4399        other = (strcmp(name, two->path) ? two->path : NULL);
4400        attr_path = name;
4401        if (o->prefix_length)
4402                strip_prefix(o->prefix_length, &name, &other);
4403
4404        if (!o->flags.allow_external)
4405                pgm = NULL;
4406
4407        if (DIFF_PAIR_UNMERGED(p)) {
4408                run_diff_cmd(pgm, name, NULL, attr_path,
4409                             NULL, NULL, NULL, o, p);
4410                return;
4411        }
4412
4413        diff_fill_oid_info(one, o->repo->index);
4414        diff_fill_oid_info(two, o->repo->index);
4415
4416        if (!pgm &&
4417            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4418            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4419                /*
4420                 * a filepair that changes between file and symlink
4421                 * needs to be split into deletion and creation.
4422                 */
4423                struct diff_filespec *null = alloc_filespec(two->path);
4424                run_diff_cmd(NULL, name, other, attr_path,
4425                             one, null, &msg,
4426                             o, p);
4427                free(null);
4428                strbuf_release(&msg);
4429
4430                null = alloc_filespec(one->path);
4431                run_diff_cmd(NULL, name, other, attr_path,
4432                             null, two, &msg, o, p);
4433                free(null);
4434        }
4435        else
4436                run_diff_cmd(pgm, name, other, attr_path,
4437                             one, two, &msg, o, p);
4438
4439        strbuf_release(&msg);
4440}
4441
4442static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4443                         struct diffstat_t *diffstat)
4444{
4445        const char *name;
4446        const char *other;
4447
4448        if (DIFF_PAIR_UNMERGED(p)) {
4449                /* unmerged */
4450                builtin_diffstat(p->one->path, NULL, NULL, NULL,
4451                                 diffstat, o, p);
4452                return;
4453        }
4454
4455        name = p->one->path;
4456        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4457
4458        if (o->prefix_length)
4459                strip_prefix(o->prefix_length, &name, &other);
4460
4461        diff_fill_oid_info(p->one, o->repo->index);
4462        diff_fill_oid_info(p->two, o->repo->index);
4463
4464        builtin_diffstat(name, other, p->one, p->two,
4465                         diffstat, o, p);
4466}
4467
4468static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4469{
4470        const char *name;
4471        const char *other;
4472        const char *attr_path;
4473
4474        if (DIFF_PAIR_UNMERGED(p)) {
4475                /* unmerged */
4476                return;
4477        }
4478
4479        name = p->one->path;
4480        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4481        attr_path = other ? other : name;
4482
4483        if (o->prefix_length)
4484                strip_prefix(o->prefix_length, &name, &other);
4485
4486        diff_fill_oid_info(p->one, o->repo->index);
4487        diff_fill_oid_info(p->two, o->repo->index);
4488
4489        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4490}
4491
4492static void prep_parse_options(struct diff_options *options);
4493
4494void repo_diff_setup(struct repository *r, struct diff_options *options)
4495{
4496        memcpy(options, &default_diff_options, sizeof(*options));
4497
4498        options->file = stdout;
4499        options->repo = r;
4500
4501        options->output_indicators[OUTPUT_INDICATOR_NEW] = '+';
4502        options->output_indicators[OUTPUT_INDICATOR_OLD] = '-';
4503        options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = ' ';
4504        options->abbrev = DEFAULT_ABBREV;
4505        options->line_termination = '\n';
4506        options->break_opt = -1;
4507        options->rename_limit = -1;
4508        options->dirstat_permille = diff_dirstat_permille_default;
4509        options->context = diff_context_default;
4510        options->interhunkcontext = diff_interhunk_context_default;
4511        options->ws_error_highlight = ws_error_highlight_default;
4512        options->flags.rename_empty = 1;
4513        options->objfind = NULL;
4514
4515        /* pathchange left =NULL by default */
4516        options->change = diff_change;
4517        options->add_remove = diff_addremove;
4518        options->use_color = diff_use_color_default;
4519        options->detect_rename = diff_detect_rename_default;
4520        options->xdl_opts |= diff_algorithm;
4521        if (diff_indent_heuristic)
4522                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4523
4524        options->orderfile = diff_order_file_cfg;
4525
4526        if (diff_no_prefix) {
4527                options->a_prefix = options->b_prefix = "";
4528        } else if (!diff_mnemonic_prefix) {
4529                options->a_prefix = "a/";
4530                options->b_prefix = "b/";
4531        }
4532
4533        options->color_moved = diff_color_moved_default;
4534        options->color_moved_ws_handling = diff_color_moved_ws_default;
4535
4536        prep_parse_options(options);
4537}
4538
4539void diff_setup_done(struct diff_options *options)
4540{
4541        unsigned check_mask = DIFF_FORMAT_NAME |
4542                              DIFF_FORMAT_NAME_STATUS |
4543                              DIFF_FORMAT_CHECKDIFF |
4544                              DIFF_FORMAT_NO_OUTPUT;
4545        /*
4546         * This must be signed because we're comparing against a potentially
4547         * negative value.
4548         */
4549        const int hexsz = the_hash_algo->hexsz;
4550
4551        if (options->set_default)
4552                options->set_default(options);
4553
4554        if (HAS_MULTI_BITS(options->output_format & check_mask))
4555                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4556
4557        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4558                die(_("-G, -S and --find-object are mutually exclusive"));
4559
4560        /*
4561         * Most of the time we can say "there are changes"
4562         * only by checking if there are changed paths, but
4563         * --ignore-whitespace* options force us to look
4564         * inside contents.
4565         */
4566
4567        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4568                options->flags.diff_from_contents = 1;
4569        else
4570                options->flags.diff_from_contents = 0;
4571
4572        if (options->flags.find_copies_harder)
4573                options->detect_rename = DIFF_DETECT_COPY;
4574
4575        if (!options->flags.relative_name)
4576                options->prefix = NULL;
4577        if (options->prefix)
4578                options->prefix_length = strlen(options->prefix);
4579        else
4580                options->prefix_length = 0;
4581
4582        if (options->output_format & (DIFF_FORMAT_NAME |
4583                                      DIFF_FORMAT_NAME_STATUS |
4584                                      DIFF_FORMAT_CHECKDIFF |
4585                                      DIFF_FORMAT_NO_OUTPUT))
4586                options->output_format &= ~(DIFF_FORMAT_RAW |
4587                                            DIFF_FORMAT_NUMSTAT |
4588                                            DIFF_FORMAT_DIFFSTAT |
4589                                            DIFF_FORMAT_SHORTSTAT |
4590                                            DIFF_FORMAT_DIRSTAT |
4591                                            DIFF_FORMAT_SUMMARY |
4592                                            DIFF_FORMAT_PATCH);
4593
4594        /*
4595         * These cases always need recursive; we do not drop caller-supplied
4596         * recursive bits for other formats here.
4597         */
4598        if (options->output_format & (DIFF_FORMAT_PATCH |
4599                                      DIFF_FORMAT_NUMSTAT |
4600                                      DIFF_FORMAT_DIFFSTAT |
4601                                      DIFF_FORMAT_SHORTSTAT |
4602                                      DIFF_FORMAT_DIRSTAT |
4603                                      DIFF_FORMAT_SUMMARY |
4604                                      DIFF_FORMAT_CHECKDIFF))
4605                options->flags.recursive = 1;
4606        /*
4607         * Also pickaxe would not work very well if you do not say recursive
4608         */
4609        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4610                options->flags.recursive = 1;
4611        /*
4612         * When patches are generated, submodules diffed against the work tree
4613         * must be checked for dirtiness too so it can be shown in the output
4614         */
4615        if (options->output_format & DIFF_FORMAT_PATCH)
4616                options->flags.dirty_submodules = 1;
4617
4618        if (options->detect_rename && options->rename_limit < 0)
4619                options->rename_limit = diff_rename_limit_default;
4620        if (hexsz < options->abbrev)
4621                options->abbrev = hexsz; /* full */
4622
4623        /*
4624         * It does not make sense to show the first hit we happened
4625         * to have found.  It does not make sense not to return with
4626         * exit code in such a case either.
4627         */
4628        if (options->flags.quick) {
4629                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4630                options->flags.exit_with_status = 1;
4631        }
4632
4633        options->diff_path_counter = 0;
4634
4635        if (options->flags.follow_renames && options->pathspec.nr != 1)
4636                die(_("--follow requires exactly one pathspec"));
4637
4638        if (!options->use_color || external_diff())
4639                options->color_moved = 0;
4640
4641        FREE_AND_NULL(options->parseopts);
4642}
4643
4644int parse_long_opt(const char *opt, const char **argv,
4645                   const char **optarg)
4646{
4647        const char *arg = argv[0];
4648        if (!skip_prefix(arg, "--", &arg))
4649                return 0;
4650        if (!skip_prefix(arg, opt, &arg))
4651                return 0;
4652        if (*arg == '=') { /* stuck form: --option=value */
4653                *optarg = arg + 1;
4654                return 1;
4655        }
4656        if (*arg != '\0')
4657                return 0;
4658        /* separate form: --option value */
4659        if (!argv[1])
4660                die("Option '--%s' requires a value", opt);
4661        *optarg = argv[1];
4662        return 2;
4663}
4664
4665static int diff_opt_stat(const struct option *opt, const char *value, int unset)
4666{
4667        struct diff_options *options = opt->value;
4668        int width = options->stat_width;
4669        int name_width = options->stat_name_width;
4670        int graph_width = options->stat_graph_width;
4671        int count = options->stat_count;
4672        char *end;
4673
4674        BUG_ON_OPT_NEG(unset);
4675
4676        if (!strcmp(opt->long_name, "stat")) {
4677                if (value) {
4678                        width = strtoul(value, &end, 10);
4679                        if (*end == ',')
4680                                name_width = strtoul(end+1, &end, 10);
4681                        if (*end == ',')
4682                                count = strtoul(end+1, &end, 10);
4683                        if (*end)
4684                                return error(_("invalid --stat value: %s"), value);
4685                }
4686        } else if (!strcmp(opt->long_name, "stat-width")) {
4687                width = strtoul(value, &end, 10);
4688                if (*end)
4689                        return error(_("%s expects a numerical value"),
4690                                     opt->long_name);
4691        } else if (!strcmp(opt->long_name, "stat-name-width")) {
4692                name_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-graph-width")) {
4697                graph_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-count")) {
4702                count = strtoul(value, &end, 10);
4703                if (*end)
4704                        return error(_("%s expects a numerical value"),
4705                                     opt->long_name);
4706        } else
4707                BUG("%s should not get here", opt->long_name);
4708
4709        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4710        options->stat_name_width = name_width;
4711        options->stat_graph_width = graph_width;
4712        options->stat_width = width;
4713        options->stat_count = count;
4714        return 0;
4715}
4716
4717static int parse_dirstat_opt(struct diff_options *options, const char *params)
4718{
4719        struct strbuf errmsg = STRBUF_INIT;
4720        if (parse_dirstat_params(options, params, &errmsg))
4721                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4722                    errmsg.buf);
4723        strbuf_release(&errmsg);
4724        /*
4725         * The caller knows a dirstat-related option is given from the command
4726         * line; allow it to say "return this_function();"
4727         */
4728        options->output_format |= DIFF_FORMAT_DIRSTAT;
4729        return 1;
4730}
4731
4732static const char diff_status_letters[] = {
4733        DIFF_STATUS_ADDED,
4734        DIFF_STATUS_COPIED,
4735        DIFF_STATUS_DELETED,
4736        DIFF_STATUS_MODIFIED,
4737        DIFF_STATUS_RENAMED,
4738        DIFF_STATUS_TYPE_CHANGED,
4739        DIFF_STATUS_UNKNOWN,
4740        DIFF_STATUS_UNMERGED,
4741        DIFF_STATUS_FILTER_AON,
4742        DIFF_STATUS_FILTER_BROKEN,
4743        '\0',
4744};
4745
4746static unsigned int filter_bit['Z' + 1];
4747
4748static void prepare_filter_bits(void)
4749{
4750        int i;
4751
4752        if (!filter_bit[DIFF_STATUS_ADDED]) {
4753                for (i = 0; diff_status_letters[i]; i++)
4754                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4755        }
4756}
4757
4758static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4759{
4760        return opt->filter & filter_bit[(int) status];
4761}
4762
4763unsigned diff_filter_bit(char status)
4764{
4765        prepare_filter_bits();
4766        return filter_bit[(int) status];
4767}
4768
4769static int diff_opt_diff_filter(const struct option *option,
4770                                const char *optarg, int unset)
4771{
4772        struct diff_options *opt = option->value;
4773        int i, optch;
4774
4775        BUG_ON_OPT_NEG(unset);
4776        prepare_filter_bits();
4777
4778        /*
4779         * If there is a negation e.g. 'd' in the input, and we haven't
4780         * initialized the filter field with another --diff-filter, start
4781         * from full set of bits, except for AON.
4782         */
4783        if (!opt->filter) {
4784                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4785                        if (optch < 'a' || 'z' < optch)
4786                                continue;
4787                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4788                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4789                        break;
4790                }
4791        }
4792
4793        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4794                unsigned int bit;
4795                int negate;
4796
4797                if ('a' <= optch && optch <= 'z') {
4798                        negate = 1;
4799                        optch = toupper(optch);
4800                } else {
4801                        negate = 0;
4802                }
4803
4804                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4805                if (!bit)
4806                        return error(_("unknown change class '%c' in --diff-filter=%s"),
4807                                     optarg[i], optarg);
4808                if (negate)
4809                        opt->filter &= ~bit;
4810                else
4811                        opt->filter |= bit;
4812        }
4813        return 0;
4814}
4815
4816static void enable_patch_output(int *fmt)
4817{
4818        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4819        *fmt |= DIFF_FORMAT_PATCH;
4820}
4821
4822static int diff_opt_ws_error_highlight(const struct option *option,
4823                                       const char *arg, int unset)
4824{
4825        struct diff_options *opt = option->value;
4826        int val = parse_ws_error_highlight(arg);
4827
4828        BUG_ON_OPT_NEG(unset);
4829        if (val < 0)
4830                return error(_("unknown value after ws-error-highlight=%.*s"),
4831                             -1 - val, arg);
4832        opt->ws_error_highlight = val;
4833        return 0;
4834}
4835
4836static int diff_opt_find_object(const struct option *option,
4837                                const char *arg, int unset)
4838{
4839        struct diff_options *opt = option->value;
4840        struct object_id oid;
4841
4842        BUG_ON_OPT_NEG(unset);
4843        if (get_oid(arg, &oid))
4844                return error(_("unable to resolve '%s'"), arg);
4845
4846        if (!opt->objfind)
4847                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4848
4849        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4850        opt->flags.recursive = 1;
4851        opt->flags.tree_in_recursive = 1;
4852        oidset_insert(opt->objfind, &oid);
4853        return 0;
4854}
4855
4856static int diff_opt_anchored(const struct option *opt,
4857                             const char *arg, int unset)
4858{
4859        struct diff_options *options = opt->value;
4860
4861        BUG_ON_OPT_NEG(unset);
4862        options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4863        ALLOC_GROW(options->anchors, options->anchors_nr + 1,
4864                   options->anchors_alloc);
4865        options->anchors[options->anchors_nr++] = xstrdup(arg);
4866        return 0;
4867}
4868
4869static int diff_opt_binary(const struct option *opt,
4870                           const char *arg, int unset)
4871{
4872        struct diff_options *options = opt->value;
4873
4874        BUG_ON_OPT_NEG(unset);
4875        BUG_ON_OPT_ARG(arg);
4876        enable_patch_output(&options->output_format);
4877        options->flags.binary = 1;
4878        return 0;
4879}
4880
4881static int diff_opt_break_rewrites(const struct option *opt,
4882                                   const char *arg, int unset)
4883{
4884        int *break_opt = opt->value;
4885        int opt1, opt2;
4886
4887        BUG_ON_OPT_NEG(unset);
4888        if (!arg)
4889                arg = "";
4890        opt1 = parse_rename_score(&arg);
4891        if (*arg == 0)
4892                opt2 = 0;
4893        else if (*arg != '/')
4894                return error(_("%s expects <n>/<m> form"), opt->long_name);
4895        else {
4896                arg++;
4897                opt2 = parse_rename_score(&arg);
4898        }
4899        if (*arg != 0)
4900                return error(_("%s expects <n>/<m> form"), opt->long_name);
4901        *break_opt = opt1 | (opt2 << 16);
4902        return 0;
4903}
4904
4905static int diff_opt_char(const struct option *opt,
4906                         const char *arg, int unset)
4907{
4908        char *value = opt->value;
4909
4910        BUG_ON_OPT_NEG(unset);
4911        if (arg[1])
4912                return error(_("%s expects a character, got '%s'"),
4913                             opt->long_name, arg);
4914        *value = arg[0];
4915        return 0;
4916}
4917
4918static int diff_opt_color_moved(const struct option *opt,
4919                                const char *arg, int unset)
4920{
4921        struct diff_options *options = opt->value;
4922
4923        if (unset) {
4924                options->color_moved = COLOR_MOVED_NO;
4925        } else if (!arg) {
4926                if (diff_color_moved_default)
4927                        options->color_moved = diff_color_moved_default;
4928                if (options->color_moved == COLOR_MOVED_NO)
4929                        options->color_moved = COLOR_MOVED_DEFAULT;
4930        } else {
4931                int cm = parse_color_moved(arg);
4932                if (cm < 0)
4933                        return error(_("bad --color-moved argument: %s"), arg);
4934                options->color_moved = cm;
4935        }
4936        return 0;
4937}
4938
4939static int diff_opt_color_moved_ws(const struct option *opt,
4940                                   const char *arg, int unset)
4941{
4942        struct diff_options *options = opt->value;
4943        unsigned cm;
4944
4945        if (unset) {
4946                options->color_moved_ws_handling = 0;
4947                return 0;
4948        }
4949
4950        cm = parse_color_moved_ws(arg);
4951        if (cm & COLOR_MOVED_WS_ERROR)
4952                return error(_("invalid mode '%s' in --color-moved-ws"), arg);
4953        options->color_moved_ws_handling = cm;
4954        return 0;
4955}
4956
4957static int diff_opt_color_words(const struct option *opt,
4958                                const char *arg, int unset)
4959{
4960        struct diff_options *options = opt->value;
4961
4962        BUG_ON_OPT_NEG(unset);
4963        options->use_color = 1;
4964        options->word_diff = DIFF_WORDS_COLOR;
4965        options->word_regex = arg;
4966        return 0;
4967}
4968
4969static int diff_opt_compact_summary(const struct option *opt,
4970                                    const char *arg, int unset)
4971{
4972        struct diff_options *options = opt->value;
4973
4974        BUG_ON_OPT_ARG(arg);
4975        if (unset) {
4976                options->flags.stat_with_summary = 0;
4977        } else {
4978                options->flags.stat_with_summary = 1;
4979                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4980        }
4981        return 0;
4982}
4983
4984static int diff_opt_diff_algorithm(const struct option *opt,
4985                                   const char *arg, int unset)
4986{
4987        struct diff_options *options = opt->value;
4988        long value = parse_algorithm_value(arg);
4989
4990        BUG_ON_OPT_NEG(unset);
4991        if (value < 0)
4992                return error(_("option diff-algorithm accepts \"myers\", "
4993                               "\"minimal\", \"patience\" and \"histogram\""));
4994
4995        /* clear out previous settings */
4996        DIFF_XDL_CLR(options, NEED_MINIMAL);
4997        options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4998        options->xdl_opts |= value;
4999        return 0;
5000}
5001
5002static int diff_opt_dirstat(const struct option *opt,
5003                            const char *arg, int unset)
5004{
5005        struct diff_options *options = opt->value;
5006
5007        BUG_ON_OPT_NEG(unset);
5008        if (!strcmp(opt->long_name, "cumulative")) {
5009                if (arg)
5010                        BUG("how come --cumulative take a value?");
5011                arg = "cumulative";
5012        } else if (!strcmp(opt->long_name, "dirstat-by-file"))
5013                parse_dirstat_opt(options, "files");
5014        parse_dirstat_opt(options, arg ? arg : "");
5015        return 0;
5016}
5017
5018static int diff_opt_find_copies(const struct option *opt,
5019                                const char *arg, int unset)
5020{
5021        struct diff_options *options = opt->value;
5022
5023        BUG_ON_OPT_NEG(unset);
5024        if (!arg)
5025                arg = "";
5026        options->rename_score = parse_rename_score(&arg);
5027        if (*arg != 0)
5028                return error(_("invalid argument to %s"), opt->long_name);
5029
5030        if (options->detect_rename == DIFF_DETECT_COPY)
5031                options->flags.find_copies_harder = 1;
5032        else
5033                options->detect_rename = DIFF_DETECT_COPY;
5034
5035        return 0;
5036}
5037
5038static int diff_opt_find_renames(const struct option *opt,
5039                                 const char *arg, int unset)
5040{
5041        struct diff_options *options = opt->value;
5042
5043        BUG_ON_OPT_NEG(unset);
5044        if (!arg)
5045                arg = "";
5046        options->rename_score = parse_rename_score(&arg);
5047        if (*arg != 0)
5048                return error(_("invalid argument to %s"), opt->long_name);
5049
5050        options->detect_rename = DIFF_DETECT_RENAME;
5051        return 0;
5052}
5053
5054static int diff_opt_follow(const struct option *opt,
5055                           const char *arg, int unset)
5056{
5057        struct diff_options *options = opt->value;
5058
5059        BUG_ON_OPT_ARG(arg);
5060        if (unset) {
5061                options->flags.follow_renames = 0;
5062                options->flags.default_follow_renames = 0;
5063        } else {
5064                options->flags.follow_renames = 1;
5065        }
5066        return 0;
5067}
5068
5069static int diff_opt_ignore_submodules(const struct option *opt,
5070                                      const char *arg, int unset)
5071{
5072        struct diff_options *options = opt->value;
5073
5074        BUG_ON_OPT_NEG(unset);
5075        if (!arg)
5076                arg = "all";
5077        options->flags.override_submodule_config = 1;
5078        handle_ignore_submodules_arg(options, arg);
5079        return 0;
5080}
5081
5082static int diff_opt_line_prefix(const struct option *opt,
5083                                const char *optarg, int unset)
5084{
5085        struct diff_options *options = opt->value;
5086
5087        BUG_ON_OPT_NEG(unset);
5088        options->line_prefix = optarg;
5089        options->line_prefix_length = strlen(options->line_prefix);
5090        graph_setup_line_prefix(options);
5091        return 0;
5092}
5093
5094static int diff_opt_no_prefix(const struct option *opt,
5095                              const char *optarg, int unset)
5096{
5097        struct diff_options *options = opt->value;
5098
5099        BUG_ON_OPT_NEG(unset);
5100        BUG_ON_OPT_ARG(optarg);
5101        options->a_prefix = "";
5102        options->b_prefix = "";
5103        return 0;
5104}
5105
5106static enum parse_opt_result diff_opt_output(struct parse_opt_ctx_t *ctx,
5107                                             const struct option *opt,
5108                                             const char *arg, int unset)
5109{
5110        struct diff_options *options = opt->value;
5111        char *path;
5112
5113        BUG_ON_OPT_NEG(unset);
5114        path = prefix_filename(ctx->prefix, arg);
5115        options->file = xfopen(path, "w");
5116        options->close_file = 1;
5117        if (options->use_color != GIT_COLOR_ALWAYS)
5118                options->use_color = GIT_COLOR_NEVER;
5119        free(path);
5120        return 0;
5121}
5122
5123static int diff_opt_patience(const struct option *opt,
5124                             const char *arg, int unset)
5125{
5126        struct diff_options *options = opt->value;
5127        int i;
5128
5129        BUG_ON_OPT_NEG(unset);
5130        BUG_ON_OPT_ARG(arg);
5131        options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
5132        /*
5133         * Both --patience and --anchored use PATIENCE_DIFF
5134         * internally, so remove any anchors previously
5135         * specified.
5136         */
5137        for (i = 0; i < options->anchors_nr; i++)
5138                free(options->anchors[i]);
5139        options->anchors_nr = 0;
5140        return 0;
5141}
5142
5143static int diff_opt_pickaxe_regex(const struct option *opt,
5144                                  const char *arg, int unset)
5145{
5146        struct diff_options *options = opt->value;
5147
5148        BUG_ON_OPT_NEG(unset);
5149        options->pickaxe = arg;
5150        options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
5151        return 0;
5152}
5153
5154static int diff_opt_pickaxe_string(const struct option *opt,
5155                                   const char *arg, int unset)
5156{
5157        struct diff_options *options = opt->value;
5158
5159        BUG_ON_OPT_NEG(unset);
5160        options->pickaxe = arg;
5161        options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
5162        return 0;
5163}
5164
5165static int diff_opt_relative(const struct option *opt,
5166                             const char *arg, int unset)
5167{
5168        struct diff_options *options = opt->value;
5169
5170        BUG_ON_OPT_NEG(unset);
5171        options->flags.relative_name = 1;
5172        if (arg)
5173                options->prefix = arg;
5174        return 0;
5175}
5176
5177static int diff_opt_submodule(const struct option *opt,
5178                              const char *arg, int unset)
5179{
5180        struct diff_options *options = opt->value;
5181
5182        BUG_ON_OPT_NEG(unset);
5183        if (!arg)
5184                arg = "log";
5185        if (parse_submodule_params(options, arg))
5186                return error(_("failed to parse --submodule option parameter: '%s'"),
5187                             arg);
5188        return 0;
5189}
5190
5191static int diff_opt_textconv(const struct option *opt,
5192                             const char *arg, int unset)
5193{
5194        struct diff_options *options = opt->value;
5195
5196        BUG_ON_OPT_ARG(arg);
5197        if (unset) {
5198                options->flags.allow_textconv = 0;
5199        } else {
5200                options->flags.allow_textconv = 1;
5201                options->flags.textconv_set_via_cmdline = 1;
5202        }
5203        return 0;
5204}
5205
5206static int diff_opt_unified(const struct option *opt,
5207                            const char *arg, int unset)
5208{
5209        struct diff_options *options = opt->value;
5210        char *s;
5211
5212        BUG_ON_OPT_NEG(unset);
5213
5214        if (arg) {
5215                options->context = strtol(arg, &s, 10);
5216                if (*s)
5217                        return error(_("%s expects a numerical value"), "--unified");
5218        }
5219        enable_patch_output(&options->output_format);
5220
5221        return 0;
5222}
5223
5224static int diff_opt_word_diff(const struct option *opt,
5225                              const char *arg, int unset)
5226{
5227        struct diff_options *options = opt->value;
5228
5229        BUG_ON_OPT_NEG(unset);
5230        if (arg) {
5231                if (!strcmp(arg, "plain"))
5232                        options->word_diff = DIFF_WORDS_PLAIN;
5233                else if (!strcmp(arg, "color")) {
5234                        options->use_color = 1;
5235                        options->word_diff = DIFF_WORDS_COLOR;
5236                }
5237                else if (!strcmp(arg, "porcelain"))
5238                        options->word_diff = DIFF_WORDS_PORCELAIN;
5239                else if (!strcmp(arg, "none"))
5240                        options->word_diff = DIFF_WORDS_NONE;
5241                else
5242                        return error(_("bad --word-diff argument: %s"), arg);
5243        } else {
5244                if (options->word_diff == DIFF_WORDS_NONE)
5245                        options->word_diff = DIFF_WORDS_PLAIN;
5246        }
5247        return 0;
5248}
5249
5250static int diff_opt_word_diff_regex(const struct option *opt,
5251                                    const char *arg, int unset)
5252{
5253        struct diff_options *options = opt->value;
5254
5255        BUG_ON_OPT_NEG(unset);
5256        if (options->word_diff == DIFF_WORDS_NONE)
5257                options->word_diff = DIFF_WORDS_PLAIN;
5258        options->word_regex = arg;
5259        return 0;
5260}
5261
5262static void prep_parse_options(struct diff_options *options)
5263{
5264        struct option parseopts[] = {
5265                OPT_GROUP(N_("Diff output format options")),
5266                OPT_BITOP('p', "patch", &options->output_format,
5267                          N_("generate patch"),
5268                          DIFF_FORMAT_PATCH, DIFF_FORMAT_NO_OUTPUT),
5269                OPT_BIT_F('s', "no-patch", &options->output_format,
5270                          N_("suppress diff output"),
5271                          DIFF_FORMAT_NO_OUTPUT, PARSE_OPT_NONEG),
5272                OPT_BITOP('u', NULL, &options->output_format,
5273                          N_("generate patch"),
5274                          DIFF_FORMAT_PATCH, DIFF_FORMAT_NO_OUTPUT),
5275                OPT_CALLBACK_F('U', "unified", options, N_("<n>"),
5276                               N_("generate diffs with <n> lines context"),
5277                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG, diff_opt_unified),
5278                OPT_BOOL('W', "function-context", &options->flags.funccontext,
5279                         N_("generate diffs with <n> lines context")),
5280                OPT_BIT_F(0, "raw", &options->output_format,
5281                          N_("generate the diff in raw format"),
5282                          DIFF_FORMAT_RAW, PARSE_OPT_NONEG),
5283                OPT_BITOP(0, "patch-with-raw", &options->output_format,
5284                          N_("synonym for '-p --raw'"),
5285                          DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW,
5286                          DIFF_FORMAT_NO_OUTPUT),
5287                OPT_BITOP(0, "patch-with-stat", &options->output_format,
5288                          N_("synonym for '-p --stat'"),
5289                          DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT,
5290                          DIFF_FORMAT_NO_OUTPUT),
5291                OPT_BIT_F(0, "numstat", &options->output_format,
5292                          N_("machine friendly --stat"),
5293                          DIFF_FORMAT_NUMSTAT, PARSE_OPT_NONEG),
5294                OPT_BIT_F(0, "shortstat", &options->output_format,
5295                          N_("output only the last line of --stat"),
5296                          DIFF_FORMAT_SHORTSTAT, PARSE_OPT_NONEG),
5297                OPT_CALLBACK_F('X', "dirstat", options, N_("<param1,param2>..."),
5298                               N_("output the distribution of relative amount of changes for each sub-directory"),
5299                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5300                               diff_opt_dirstat),
5301                OPT_CALLBACK_F(0, "cumulative", options, NULL,
5302                               N_("synonym for --dirstat=cumulative"),
5303                               PARSE_OPT_NONEG | PARSE_OPT_NOARG,
5304                               diff_opt_dirstat),
5305                OPT_CALLBACK_F(0, "dirstat-by-file", options, N_("<param1,param2>..."),
5306                               N_("synonym for --dirstat=files,param1,param2..."),
5307                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5308                               diff_opt_dirstat),
5309                OPT_BIT_F(0, "check", &options->output_format,
5310                          N_("warn if changes introduce conflict markers or whitespace errors"),
5311                          DIFF_FORMAT_CHECKDIFF, PARSE_OPT_NONEG),
5312                OPT_BIT_F(0, "summary", &options->output_format,
5313                          N_("condensed summary such as creations, renames and mode changes"),
5314                          DIFF_FORMAT_SUMMARY, PARSE_OPT_NONEG),
5315                OPT_BIT_F(0, "name-only", &options->output_format,
5316                          N_("show only names of changed files"),
5317                          DIFF_FORMAT_NAME, PARSE_OPT_NONEG),
5318                OPT_BIT_F(0, "name-status", &options->output_format,
5319                          N_("show only names and status of changed files"),
5320                          DIFF_FORMAT_NAME_STATUS, PARSE_OPT_NONEG),
5321                OPT_CALLBACK_F(0, "stat", options, N_("<width>[,<name-width>[,<count>]]"),
5322                               N_("generate diffstat"),
5323                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG, diff_opt_stat),
5324                OPT_CALLBACK_F(0, "stat-width", options, N_("<width>"),
5325                               N_("generate diffstat with a given width"),
5326                               PARSE_OPT_NONEG, diff_opt_stat),
5327                OPT_CALLBACK_F(0, "stat-name-width", options, N_("<width>"),
5328                               N_("generate diffstat with a given name width"),
5329                               PARSE_OPT_NONEG, diff_opt_stat),
5330                OPT_CALLBACK_F(0, "stat-graph-width", options, N_("<width>"),
5331                               N_("generate diffstat with a given graph width"),
5332                               PARSE_OPT_NONEG, diff_opt_stat),
5333                OPT_CALLBACK_F(0, "stat-count", options, N_("<count>"),
5334                               N_("generate diffstat with limited lines"),
5335                               PARSE_OPT_NONEG, diff_opt_stat),
5336                OPT_CALLBACK_F(0, "compact-summary", options, NULL,
5337                               N_("generate compact summary in diffstat"),
5338                               PARSE_OPT_NOARG, diff_opt_compact_summary),
5339                OPT_CALLBACK_F(0, "binary", options, NULL,
5340                               N_("output a binary diff that can be applied"),
5341                               PARSE_OPT_NONEG | PARSE_OPT_NOARG, diff_opt_binary),
5342                OPT_BOOL(0, "full-index", &options->flags.full_index,
5343                         N_("show full pre- and post-image object names on the \"index\" lines")),
5344                OPT_COLOR_FLAG(0, "color", &options->use_color,
5345                               N_("show colored diff")),
5346                OPT_CALLBACK_F(0, "ws-error-highlight", options, N_("<kind>"),
5347                               N_("highlight whitespace errors in the 'context', 'old' or 'new' lines in the diff"),
5348                               PARSE_OPT_NONEG, diff_opt_ws_error_highlight),
5349                OPT_SET_INT('z', NULL, &options->line_termination,
5350                            N_("do not munge pathnames and use NULs as output field terminators in --raw or --numstat"),
5351                            0),
5352                OPT__ABBREV(&options->abbrev),
5353                OPT_STRING_F(0, "src-prefix", &options->a_prefix, N_("<prefix>"),
5354                             N_("show the given source prefix instead of \"a/\""),
5355                             PARSE_OPT_NONEG),
5356                OPT_STRING_F(0, "dst-prefix", &options->b_prefix, N_("<prefix>"),
5357                             N_("show the given destination prefix instead of \"b/\""),
5358                             PARSE_OPT_NONEG),
5359                OPT_CALLBACK_F(0, "line-prefix", options, N_("<prefix>"),
5360                               N_("prepend an additional prefix to every line of output"),
5361                               PARSE_OPT_NONEG, diff_opt_line_prefix),
5362                OPT_CALLBACK_F(0, "no-prefix", options, NULL,
5363                               N_("do not show any source or destination prefix"),
5364                               PARSE_OPT_NONEG | PARSE_OPT_NOARG, diff_opt_no_prefix),
5365                OPT_INTEGER_F(0, "inter-hunk-context", &options->interhunkcontext,
5366                              N_("show context between diff hunks up to the specified number of lines"),
5367                              PARSE_OPT_NONEG),
5368                OPT_CALLBACK_F(0, "output-indicator-new",
5369                               &options->output_indicators[OUTPUT_INDICATOR_NEW],
5370                               N_("<char>"),
5371                               N_("specify the character to indicate a new line instead of '+'"),
5372                               PARSE_OPT_NONEG, diff_opt_char),
5373                OPT_CALLBACK_F(0, "output-indicator-old",
5374                               &options->output_indicators[OUTPUT_INDICATOR_OLD],
5375                               N_("<char>"),
5376                               N_("specify the character to indicate an old line instead of '-'"),
5377                               PARSE_OPT_NONEG, diff_opt_char),
5378                OPT_CALLBACK_F(0, "output-indicator-context",
5379                               &options->output_indicators[OUTPUT_INDICATOR_CONTEXT],
5380                               N_("<char>"),
5381                               N_("specify the character to indicate a context instead of ' '"),
5382                               PARSE_OPT_NONEG, diff_opt_char),
5383
5384                OPT_GROUP(N_("Diff rename options")),
5385                OPT_CALLBACK_F('B', "break-rewrites", &options->break_opt, N_("<n>[/<m>]"),
5386                               N_("break complete rewrite changes into pairs of delete and create"),
5387                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5388                               diff_opt_break_rewrites),
5389                OPT_CALLBACK_F('M', "find-renames", options, N_("<n>"),
5390                               N_("detect renames"),
5391                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5392                               diff_opt_find_renames),
5393                OPT_SET_INT_F('D', "irreversible-delete", &options->irreversible_delete,
5394                              N_("omit the preimage for deletes"),
5395                              1, PARSE_OPT_NONEG),
5396                OPT_CALLBACK_F('C', "find-copies", options, N_("<n>"),
5397                               N_("detect copies"),
5398                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5399                               diff_opt_find_copies),
5400                OPT_BOOL(0, "find-copies-harder", &options->flags.find_copies_harder,
5401                         N_("use unmodified files as source to find copies")),
5402                OPT_SET_INT_F(0, "no-renames", &options->detect_rename,
5403                              N_("disable rename detection"),
5404                              0, PARSE_OPT_NONEG),
5405                OPT_BOOL(0, "rename-empty", &options->flags.rename_empty,
5406                         N_("use empty blobs as rename source")),
5407                OPT_CALLBACK_F(0, "follow", options, NULL,
5408                               N_("continue listing the history of a file beyond renames"),
5409                               PARSE_OPT_NOARG, diff_opt_follow),
5410                OPT_INTEGER('l', NULL, &options->rename_limit,
5411                            N_("prevent rename/copy detection if the number of rename/copy targets exceeds given limit")),
5412
5413                OPT_GROUP(N_("Diff algorithm options")),
5414                OPT_BIT(0, "minimal", &options->xdl_opts,
5415                        N_("produce the smallest possible diff"),
5416                        XDF_NEED_MINIMAL),
5417                OPT_BIT_F('w', "ignore-all-space", &options->xdl_opts,
5418                          N_("ignore whitespace when comparing lines"),
5419                          XDF_IGNORE_WHITESPACE, PARSE_OPT_NONEG),
5420                OPT_BIT_F('b', "ignore-space-change", &options->xdl_opts,
5421                          N_("ignore changes in amount of whitespace"),
5422                          XDF_IGNORE_WHITESPACE_CHANGE, PARSE_OPT_NONEG),
5423                OPT_BIT_F(0, "ignore-space-at-eol", &options->xdl_opts,
5424                          N_("ignore changes in whitespace at EOL"),
5425                          XDF_IGNORE_WHITESPACE_AT_EOL, PARSE_OPT_NONEG),
5426                OPT_BIT_F(0, "ignore-cr-at-eol", &options->xdl_opts,
5427                          N_("ignore carrier-return at the end of line"),
5428                          XDF_IGNORE_CR_AT_EOL, PARSE_OPT_NONEG),
5429                OPT_BIT_F(0, "ignore-blank-lines", &options->xdl_opts,
5430                          N_("ignore changes whose lines are all blank"),
5431                          XDF_IGNORE_BLANK_LINES, PARSE_OPT_NONEG),
5432                OPT_BIT(0, "indent-heuristic", &options->xdl_opts,
5433                        N_("heuristic to shift diff hunk boundaries for easy reading"),
5434                        XDF_INDENT_HEURISTIC),
5435                OPT_CALLBACK_F(0, "patience", options, NULL,
5436                               N_("generate diff using the \"patience diff\" algorithm"),
5437                               PARSE_OPT_NONEG | PARSE_OPT_NOARG,
5438                               diff_opt_patience),
5439                OPT_BITOP(0, "histogram", &options->xdl_opts,
5440                          N_("generate diff using the \"histogram diff\" algorithm"),
5441                          XDF_HISTOGRAM_DIFF, XDF_DIFF_ALGORITHM_MASK),
5442                OPT_CALLBACK_F(0, "diff-algorithm", options, N_("<algorithm>"),
5443                               N_("choose a diff algorithm"),
5444                               PARSE_OPT_NONEG, diff_opt_diff_algorithm),
5445                OPT_CALLBACK_F(0, "anchored", options, N_("<text>"),
5446                               N_("generate diff using the \"anchored diff\" algorithm"),
5447                               PARSE_OPT_NONEG, diff_opt_anchored),
5448                OPT_CALLBACK_F(0, "word-diff", options, N_("<mode>"),
5449                               N_("show word diff, using <mode> to delimit changed words"),
5450                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG, diff_opt_word_diff),
5451                OPT_CALLBACK_F(0, "word-diff-regex", options, N_("<regex>"),
5452                               N_("use <regex> to decide what a word is"),
5453                               PARSE_OPT_NONEG, diff_opt_word_diff_regex),
5454                OPT_CALLBACK_F(0, "color-words", options, N_("<regex>"),
5455                               N_("equivalent to --word-diff=color --word-diff-regex=<regex>"),
5456                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG, diff_opt_color_words),
5457                OPT_CALLBACK_F(0, "color-moved", options, N_("<mode>"),
5458                               N_("moved lines of code are colored differently"),
5459                               PARSE_OPT_OPTARG, diff_opt_color_moved),
5460                OPT_CALLBACK_F(0, "color-moved-ws", options, N_("<mode>"),
5461                               N_("how white spaces are ignored in --color-moved"),
5462                               0, diff_opt_color_moved_ws),
5463
5464                OPT_GROUP(N_("Other diff options")),
5465                OPT_CALLBACK_F(0, "relative", options, N_("<prefix>"),
5466                               N_("when run from subdir, exclude changes outside and show relative paths"),
5467                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5468                               diff_opt_relative),
5469                OPT_BOOL('a', "text", &options->flags.text,
5470                         N_("treat all files as text")),
5471                OPT_BOOL('R', NULL, &options->flags.reverse_diff,
5472                         N_("swap two inputs, reverse the diff")),
5473                OPT_BOOL(0, "exit-code", &options->flags.exit_with_status,
5474                         N_("exit with 1 if there were differences, 0 otherwise")),
5475                OPT_BOOL(0, "quiet", &options->flags.quick,
5476                         N_("disable all output of the program")),
5477                OPT_BOOL(0, "ext-diff", &options->flags.allow_external,
5478                         N_("allow an external diff helper to be executed")),
5479                OPT_CALLBACK_F(0, "textconv", options, NULL,
5480                               N_("run external text conversion filters when comparing binary files"),
5481                               PARSE_OPT_NOARG, diff_opt_textconv),
5482                OPT_CALLBACK_F(0, "ignore-submodules", options, N_("<when>"),
5483                               N_("ignore changes to submodules in the diff generation"),
5484                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5485                               diff_opt_ignore_submodules),
5486                OPT_CALLBACK_F(0, "submodule", options, N_("<format>"),
5487                               N_("specify how differences in submodules are shown"),
5488                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5489                               diff_opt_submodule),
5490                OPT_SET_INT_F(0, "ita-invisible-in-index", &options->ita_invisible_in_index,
5491                              N_("hide 'git add -N' entries from the index"),
5492                              1, PARSE_OPT_NONEG),
5493                OPT_SET_INT_F(0, "ita-visible-in-index", &options->ita_invisible_in_index,
5494                              N_("treat 'git add -N' entries as real in the index"),
5495                              0, PARSE_OPT_NONEG),
5496                OPT_CALLBACK_F('S', NULL, options, N_("<string>"),
5497                               N_("look for differences that change the number of occurrences of the specified string"),
5498                               0, diff_opt_pickaxe_string),
5499                OPT_CALLBACK_F('G', NULL, options, N_("<regex>"),
5500                               N_("look for differences that change the number of occurrences of the specified regex"),
5501                               0, diff_opt_pickaxe_regex),
5502                OPT_BIT_F(0, "pickaxe-all", &options->pickaxe_opts,
5503                          N_("show all changes in the changeset with -S or -G"),
5504                          DIFF_PICKAXE_ALL, PARSE_OPT_NONEG),
5505                OPT_BIT_F(0, "pickaxe-regex", &options->pickaxe_opts,
5506                          N_("treat <string> in -S as extended POSIX regular expression"),
5507                          DIFF_PICKAXE_REGEX, PARSE_OPT_NONEG),
5508                OPT_FILENAME('O', NULL, &options->orderfile,
5509                             N_("control the order in which files appear in the output")),
5510                OPT_CALLBACK_F(0, "find-object", options, N_("<object-id>"),
5511                               N_("look for differences that change the number of occurrences of the specified object"),
5512                               PARSE_OPT_NONEG, diff_opt_find_object),
5513                OPT_CALLBACK_F(0, "diff-filter", options, N_("[(A|C|D|M|R|T|U|X|B)...[*]]"),
5514                               N_("select files by diff type"),
5515                               PARSE_OPT_NONEG, diff_opt_diff_filter),
5516                { OPTION_CALLBACK, 0, "output", options, N_("<file>"),
5517                  N_("Output to a specific file"),
5518                  PARSE_OPT_NONEG, NULL, 0, diff_opt_output },
5519
5520                OPT_END()
5521        };
5522
5523        ALLOC_ARRAY(options->parseopts, ARRAY_SIZE(parseopts));
5524        memcpy(options->parseopts, parseopts, sizeof(parseopts));
5525}
5526
5527int diff_opt_parse(struct diff_options *options,
5528                   const char **av, int ac, const char *prefix)
5529{
5530        if (!prefix)
5531                prefix = "";
5532
5533        ac = parse_options(ac, av, prefix, options->parseopts, NULL,
5534                           PARSE_OPT_KEEP_DASHDASH |
5535                           PARSE_OPT_KEEP_UNKNOWN |
5536                           PARSE_OPT_NO_INTERNAL_HELP |
5537                           PARSE_OPT_ONE_SHOT |
5538                           PARSE_OPT_STOP_AT_NON_OPTION);
5539
5540        return ac;
5541}
5542
5543int parse_rename_score(const char **cp_p)
5544{
5545        unsigned long num, scale;
5546        int ch, dot;
5547        const char *cp = *cp_p;
5548
5549        num = 0;
5550        scale = 1;
5551        dot = 0;
5552        for (;;) {
5553                ch = *cp;
5554                if ( !dot && ch == '.' ) {
5555                        scale = 1;
5556                        dot = 1;
5557                } else if ( ch == '%' ) {
5558                        scale = dot ? scale*100 : 100;
5559                        cp++;   /* % is always at the end */
5560                        break;
5561                } else if ( ch >= '0' && ch <= '9' ) {
5562                        if ( scale < 100000 ) {
5563                                scale *= 10;
5564                                num = (num*10) + (ch-'0');
5565                        }
5566                } else {
5567                        break;
5568                }
5569                cp++;
5570        }
5571        *cp_p = cp;
5572
5573        /* user says num divided by scale and we say internally that
5574         * is MAX_SCORE * num / scale.
5575         */
5576        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5577}
5578
5579struct diff_queue_struct diff_queued_diff;
5580
5581void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5582{
5583        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5584        queue->queue[queue->nr++] = dp;
5585}
5586
5587struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5588                                 struct diff_filespec *one,
5589                                 struct diff_filespec *two)
5590{
5591        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5592        dp->one = one;
5593        dp->two = two;
5594        if (queue)
5595                diff_q(queue, dp);
5596        return dp;
5597}
5598
5599void diff_free_filepair(struct diff_filepair *p)
5600{
5601        free_filespec(p->one);
5602        free_filespec(p->two);
5603        free(p);
5604}
5605
5606const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5607{
5608        int abblen;
5609        const char *abbrev;
5610
5611        /* Do we want all 40 hex characters? */
5612        if (len == the_hash_algo->hexsz)
5613                return oid_to_hex(oid);
5614
5615        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5616        abbrev = diff_abbrev_oid(oid, len);
5617
5618        if (!print_sha1_ellipsis())
5619                return abbrev;
5620
5621        abblen = strlen(abbrev);
5622
5623        /*
5624         * In well-behaved cases, where the abbreviated result is the
5625         * same as the requested length, append three dots after the
5626         * abbreviation (hence the whole logic is limited to the case
5627         * where abblen < 37); when the actual abbreviated result is a
5628         * bit longer than the requested length, we reduce the number
5629         * of dots so that they match the well-behaved ones.  However,
5630         * if the actual abbreviation is longer than the requested
5631         * length by more than three, we give up on aligning, and add
5632         * three dots anyway, to indicate that the output is not the
5633         * full object name.  Yes, this may be suboptimal, but this
5634         * appears only in "diff --raw --abbrev" output and it is not
5635         * worth the effort to change it now.  Note that this would
5636         * likely to work fine when the automatic sizing of default
5637         * abbreviation length is used--we would be fed -1 in "len" in
5638         * that case, and will end up always appending three-dots, but
5639         * the automatic sizing is supposed to give abblen that ensures
5640         * uniqueness across all objects (statistically speaking).
5641         */
5642        if (abblen < the_hash_algo->hexsz - 3) {
5643                static char hex[GIT_MAX_HEXSZ + 1];
5644                if (len < abblen && abblen <= len + 2)
5645                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5646                else
5647                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5648                return hex;
5649        }
5650
5651        return oid_to_hex(oid);
5652}
5653
5654static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5655{
5656        int line_termination = opt->line_termination;
5657        int inter_name_termination = line_termination ? '\t' : '\0';
5658
5659        fprintf(opt->file, "%s", diff_line_prefix(opt));
5660        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5661                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5662                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5663                fprintf(opt->file, "%s ",
5664                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5665        }
5666        if (p->score) {
5667                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5668                        inter_name_termination);
5669        } else {
5670                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5671        }
5672
5673        if (p->status == DIFF_STATUS_COPIED ||
5674            p->status == DIFF_STATUS_RENAMED) {
5675                const char *name_a, *name_b;
5676                name_a = p->one->path;
5677                name_b = p->two->path;
5678                strip_prefix(opt->prefix_length, &name_a, &name_b);
5679                write_name_quoted(name_a, opt->file, inter_name_termination);
5680                write_name_quoted(name_b, opt->file, line_termination);
5681        } else {
5682                const char *name_a, *name_b;
5683                name_a = p->one->mode ? p->one->path : p->two->path;
5684                name_b = NULL;
5685                strip_prefix(opt->prefix_length, &name_a, &name_b);
5686                write_name_quoted(name_a, opt->file, line_termination);
5687        }
5688}
5689
5690int diff_unmodified_pair(struct diff_filepair *p)
5691{
5692        /* This function is written stricter than necessary to support
5693         * the currently implemented transformers, but the idea is to
5694         * let transformers to produce diff_filepairs any way they want,
5695         * and filter and clean them up here before producing the output.
5696         */
5697        struct diff_filespec *one = p->one, *two = p->two;
5698
5699        if (DIFF_PAIR_UNMERGED(p))
5700                return 0; /* unmerged is interesting */
5701
5702        /* deletion, addition, mode or type change
5703         * and rename are all interesting.
5704         */
5705        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5706            DIFF_PAIR_MODE_CHANGED(p) ||
5707            strcmp(one->path, two->path))
5708                return 0;
5709
5710        /* both are valid and point at the same path.  that is, we are
5711         * dealing with a change.
5712         */
5713        if (one->oid_valid && two->oid_valid &&
5714            oideq(&one->oid, &two->oid) &&
5715            !one->dirty_submodule && !two->dirty_submodule)
5716                return 1; /* no change */
5717        if (!one->oid_valid && !two->oid_valid)
5718                return 1; /* both look at the same file on the filesystem. */
5719        return 0;
5720}
5721
5722static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5723{
5724        if (diff_unmodified_pair(p))
5725                return;
5726
5727        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5728            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5729                return; /* no tree diffs in patch format */
5730
5731        run_diff(p, o);
5732}
5733
5734static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5735                            struct diffstat_t *diffstat)
5736{
5737        if (diff_unmodified_pair(p))
5738                return;
5739
5740        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5741            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5742                return; /* no useful stat for tree diffs */
5743
5744        run_diffstat(p, o, diffstat);
5745}
5746
5747static void diff_flush_checkdiff(struct diff_filepair *p,
5748                struct diff_options *o)
5749{
5750        if (diff_unmodified_pair(p))
5751                return;
5752
5753        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5754            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5755                return; /* nothing to check in tree diffs */
5756
5757        run_checkdiff(p, o);
5758}
5759
5760int diff_queue_is_empty(void)
5761{
5762        struct diff_queue_struct *q = &diff_queued_diff;
5763        int i;
5764        for (i = 0; i < q->nr; i++)
5765                if (!diff_unmodified_pair(q->queue[i]))
5766                        return 0;
5767        return 1;
5768}
5769
5770#if DIFF_DEBUG
5771void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5772{
5773        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5774                x, one ? one : "",
5775                s->path,
5776                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5777                s->mode,
5778                s->oid_valid ? oid_to_hex(&s->oid) : "");
5779        fprintf(stderr, "queue[%d] %s size %lu\n",
5780                x, one ? one : "",
5781                s->size);
5782}
5783
5784void diff_debug_filepair(const struct diff_filepair *p, int i)
5785{
5786        diff_debug_filespec(p->one, i, "one");
5787        diff_debug_filespec(p->two, i, "two");
5788        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5789                p->score, p->status ? p->status : '?',
5790                p->one->rename_used, p->broken_pair);
5791}
5792
5793void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5794{
5795        int i;
5796        if (msg)
5797                fprintf(stderr, "%s\n", msg);
5798        fprintf(stderr, "q->nr = %d\n", q->nr);
5799        for (i = 0; i < q->nr; i++) {
5800                struct diff_filepair *p = q->queue[i];
5801                diff_debug_filepair(p, i);
5802        }
5803}
5804#endif
5805
5806static void diff_resolve_rename_copy(void)
5807{
5808        int i;
5809        struct diff_filepair *p;
5810        struct diff_queue_struct *q = &diff_queued_diff;
5811
5812        diff_debug_queue("resolve-rename-copy", q);
5813
5814        for (i = 0; i < q->nr; i++) {
5815                p = q->queue[i];
5816                p->status = 0; /* undecided */
5817                if (DIFF_PAIR_UNMERGED(p))
5818                        p->status = DIFF_STATUS_UNMERGED;
5819                else if (!DIFF_FILE_VALID(p->one))
5820                        p->status = DIFF_STATUS_ADDED;
5821                else if (!DIFF_FILE_VALID(p->two))
5822                        p->status = DIFF_STATUS_DELETED;
5823                else if (DIFF_PAIR_TYPE_CHANGED(p))
5824                        p->status = DIFF_STATUS_TYPE_CHANGED;
5825
5826                /* from this point on, we are dealing with a pair
5827                 * whose both sides are valid and of the same type, i.e.
5828                 * either in-place edit or rename/copy edit.
5829                 */
5830                else if (DIFF_PAIR_RENAME(p)) {
5831                        /*
5832                         * A rename might have re-connected a broken
5833                         * pair up, causing the pathnames to be the
5834                         * same again. If so, that's not a rename at
5835                         * all, just a modification..
5836                         *
5837                         * Otherwise, see if this source was used for
5838                         * multiple renames, in which case we decrement
5839                         * the count, and call it a copy.
5840                         */
5841                        if (!strcmp(p->one->path, p->two->path))
5842                                p->status = DIFF_STATUS_MODIFIED;
5843                        else if (--p->one->rename_used > 0)
5844                                p->status = DIFF_STATUS_COPIED;
5845                        else
5846                                p->status = DIFF_STATUS_RENAMED;
5847                }
5848                else if (!oideq(&p->one->oid, &p->two->oid) ||
5849                         p->one->mode != p->two->mode ||
5850                         p->one->dirty_submodule ||
5851                         p->two->dirty_submodule ||
5852                         is_null_oid(&p->one->oid))
5853                        p->status = DIFF_STATUS_MODIFIED;
5854                else {
5855                        /* This is a "no-change" entry and should not
5856                         * happen anymore, but prepare for broken callers.
5857                         */
5858                        error("feeding unmodified %s to diffcore",
5859                              p->one->path);
5860                        p->status = DIFF_STATUS_UNKNOWN;
5861                }
5862        }
5863        diff_debug_queue("resolve-rename-copy done", q);
5864}
5865
5866static int check_pair_status(struct diff_filepair *p)
5867{
5868        switch (p->status) {
5869        case DIFF_STATUS_UNKNOWN:
5870                return 0;
5871        case 0:
5872                die("internal error in diff-resolve-rename-copy");
5873        default:
5874                return 1;
5875        }
5876}
5877
5878static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5879{
5880        int fmt = opt->output_format;
5881
5882        if (fmt & DIFF_FORMAT_CHECKDIFF)
5883                diff_flush_checkdiff(p, opt);
5884        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5885                diff_flush_raw(p, opt);
5886        else if (fmt & DIFF_FORMAT_NAME) {
5887                const char *name_a, *name_b;
5888                name_a = p->two->path;
5889                name_b = NULL;
5890                strip_prefix(opt->prefix_length, &name_a, &name_b);
5891                fprintf(opt->file, "%s", diff_line_prefix(opt));
5892                write_name_quoted(name_a, opt->file, opt->line_termination);
5893        }
5894}
5895
5896static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5897{
5898        struct strbuf sb = STRBUF_INIT;
5899        if (fs->mode)
5900                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5901        else
5902                strbuf_addf(&sb, " %s ", newdelete);
5903
5904        quote_c_style(fs->path, &sb, NULL, 0);
5905        strbuf_addch(&sb, '\n');
5906        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5907                         sb.buf, sb.len, 0);
5908        strbuf_release(&sb);
5909}
5910
5911static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5912                int show_name)
5913{
5914        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5915                struct strbuf sb = STRBUF_INIT;
5916                strbuf_addf(&sb, " mode change %06o => %06o",
5917                            p->one->mode, p->two->mode);
5918                if (show_name) {
5919                        strbuf_addch(&sb, ' ');
5920                        quote_c_style(p->two->path, &sb, NULL, 0);
5921                }
5922                strbuf_addch(&sb, '\n');
5923                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5924                                 sb.buf, sb.len, 0);
5925                strbuf_release(&sb);
5926        }
5927}
5928
5929static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5930                struct diff_filepair *p)
5931{
5932        struct strbuf sb = STRBUF_INIT;
5933        struct strbuf names = STRBUF_INIT;
5934
5935        pprint_rename(&names, p->one->path, p->two->path);
5936        strbuf_addf(&sb, " %s %s (%d%%)\n",
5937                    renamecopy, names.buf, similarity_index(p));
5938        strbuf_release(&names);
5939        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5940                                 sb.buf, sb.len, 0);
5941        show_mode_change(opt, p, 0);
5942        strbuf_release(&sb);
5943}
5944
5945static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5946{
5947        switch(p->status) {
5948        case DIFF_STATUS_DELETED:
5949                show_file_mode_name(opt, "delete", p->one);
5950                break;
5951        case DIFF_STATUS_ADDED:
5952                show_file_mode_name(opt, "create", p->two);
5953                break;
5954        case DIFF_STATUS_COPIED:
5955                show_rename_copy(opt, "copy", p);
5956                break;
5957        case DIFF_STATUS_RENAMED:
5958                show_rename_copy(opt, "rename", p);
5959                break;
5960        default:
5961                if (p->score) {
5962                        struct strbuf sb = STRBUF_INIT;
5963                        strbuf_addstr(&sb, " rewrite ");
5964                        quote_c_style(p->two->path, &sb, NULL, 0);
5965                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5966                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5967                                         sb.buf, sb.len, 0);
5968                        strbuf_release(&sb);
5969                }
5970                show_mode_change(opt, p, !p->score);
5971                break;
5972        }
5973}
5974
5975struct patch_id_t {
5976        git_SHA_CTX *ctx;
5977        int patchlen;
5978};
5979
5980static int remove_space(char *line, int len)
5981{
5982        int i;
5983        char *dst = line;
5984        unsigned char c;
5985
5986        for (i = 0; i < len; i++)
5987                if (!isspace((c = line[i])))
5988                        *dst++ = c;
5989
5990        return dst - line;
5991}
5992
5993void flush_one_hunk(struct object_id *result, git_SHA_CTX *ctx)
5994{
5995        unsigned char hash[GIT_MAX_RAWSZ];
5996        unsigned short carry = 0;
5997        int i;
5998
5999        git_SHA1_Final(hash, ctx);
6000        git_SHA1_Init(ctx);
6001        /* 20-byte sum, with carry */
6002        for (i = 0; i < GIT_SHA1_RAWSZ; ++i) {
6003                carry += result->hash[i] + hash[i];
6004                result->hash[i] = carry;
6005                carry >>= 8;
6006        }
6007}
6008
6009static void patch_id_consume(void *priv, char *line, unsigned long len)
6010{
6011        struct patch_id_t *data = priv;
6012        int new_len;
6013
6014        new_len = remove_space(line, len);
6015
6016        git_SHA1_Update(data->ctx, line, new_len);
6017        data->patchlen += new_len;
6018}
6019
6020static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
6021{
6022        git_SHA1_Update(ctx, str, strlen(str));
6023}
6024
6025static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
6026{
6027        /* large enough for 2^32 in octal */
6028        char buf[12];
6029        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
6030        git_SHA1_Update(ctx, buf, len);
6031}
6032
6033/* returns 0 upon success, and writes result into oid */
6034static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only, int stable)
6035{
6036        struct diff_queue_struct *q = &diff_queued_diff;
6037        int i;
6038        git_SHA_CTX ctx;
6039        struct patch_id_t data;
6040
6041        git_SHA1_Init(&ctx);
6042        memset(&data, 0, sizeof(struct patch_id_t));
6043        data.ctx = &ctx;
6044        oidclr(oid);
6045
6046        for (i = 0; i < q->nr; i++) {
6047                xpparam_t xpp;
6048                xdemitconf_t xecfg;
6049                mmfile_t mf1, mf2;
6050                struct diff_filepair *p = q->queue[i];
6051                int len1, len2;
6052
6053                memset(&xpp, 0, sizeof(xpp));
6054                memset(&xecfg, 0, sizeof(xecfg));
6055                if (p->status == 0)
6056                        return error("internal diff status error");
6057                if (p->status == DIFF_STATUS_UNKNOWN)
6058                        continue;
6059                if (diff_unmodified_pair(p))
6060                        continue;
6061                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
6062                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
6063                        continue;
6064                if (DIFF_PAIR_UNMERGED(p))
6065                        continue;
6066
6067                diff_fill_oid_info(p->one, options->repo->index);
6068                diff_fill_oid_info(p->two, options->repo->index);
6069
6070                len1 = remove_space(p->one->path, strlen(p->one->path));
6071                len2 = remove_space(p->two->path, strlen(p->two->path));
6072                patch_id_add_string(&ctx, "diff--git");
6073                patch_id_add_string(&ctx, "a/");
6074                git_SHA1_Update(&ctx, p->one->path, len1);
6075                patch_id_add_string(&ctx, "b/");
6076                git_SHA1_Update(&ctx, p->two->path, len2);
6077
6078                if (p->one->mode == 0) {
6079                        patch_id_add_string(&ctx, "newfilemode");
6080                        patch_id_add_mode(&ctx, p->two->mode);
6081                        patch_id_add_string(&ctx, "---/dev/null");
6082                        patch_id_add_string(&ctx, "+++b/");
6083                        git_SHA1_Update(&ctx, p->two->path, len2);
6084                } else if (p->two->mode == 0) {
6085                        patch_id_add_string(&ctx, "deletedfilemode");
6086                        patch_id_add_mode(&ctx, p->one->mode);
6087                        patch_id_add_string(&ctx, "---a/");
6088                        git_SHA1_Update(&ctx, p->one->path, len1);
6089                        patch_id_add_string(&ctx, "+++/dev/null");
6090                } else {
6091                        patch_id_add_string(&ctx, "---a/");
6092                        git_SHA1_Update(&ctx, p->one->path, len1);
6093                        patch_id_add_string(&ctx, "+++b/");
6094                        git_SHA1_Update(&ctx, p->two->path, len2);
6095                }
6096
6097                if (diff_header_only)
6098                        continue;
6099
6100                if (fill_mmfile(options->repo, &mf1, p->one) < 0 ||
6101                    fill_mmfile(options->repo, &mf2, p->two) < 0)
6102                        return error("unable to read files to diff");
6103
6104                if (diff_filespec_is_binary(options->repo, p->one) ||
6105                    diff_filespec_is_binary(options->repo, p->two)) {
6106                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
6107                                        GIT_SHA1_HEXSZ);
6108                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
6109                                        GIT_SHA1_HEXSZ);
6110                        continue;
6111                }
6112
6113                xpp.flags = 0;
6114                xecfg.ctxlen = 3;
6115                xecfg.flags = 0;
6116                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
6117                                  patch_id_consume, &data, &xpp, &xecfg))
6118                        return error("unable to generate patch-id diff for %s",
6119                                     p->one->path);
6120
6121                if (stable)
6122                        flush_one_hunk(oid, &ctx);
6123        }
6124
6125        if (!stable)
6126                git_SHA1_Final(oid->hash, &ctx);
6127
6128        return 0;
6129}
6130
6131int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only, int stable)
6132{
6133        struct diff_queue_struct *q = &diff_queued_diff;
6134        int i;
6135        int result = diff_get_patch_id(options, oid, diff_header_only, stable);
6136
6137        for (i = 0; i < q->nr; i++)
6138                diff_free_filepair(q->queue[i]);
6139
6140        free(q->queue);
6141        DIFF_QUEUE_CLEAR(q);
6142
6143        return result;
6144}
6145
6146static int is_summary_empty(const struct diff_queue_struct *q)
6147{
6148        int i;
6149
6150        for (i = 0; i < q->nr; i++) {
6151                const struct diff_filepair *p = q->queue[i];
6152
6153                switch (p->status) {
6154                case DIFF_STATUS_DELETED:
6155                case DIFF_STATUS_ADDED:
6156                case DIFF_STATUS_COPIED:
6157                case DIFF_STATUS_RENAMED:
6158                        return 0;
6159                default:
6160                        if (p->score)
6161                                return 0;
6162                        if (p->one->mode && p->two->mode &&
6163                            p->one->mode != p->two->mode)
6164                                return 0;
6165                        break;
6166                }
6167        }
6168        return 1;
6169}
6170
6171static const char rename_limit_warning[] =
6172N_("inexact rename detection was skipped due to too many files.");
6173
6174static const char degrade_cc_to_c_warning[] =
6175N_("only found copies from modified paths due to too many files.");
6176
6177static const char rename_limit_advice[] =
6178N_("you may want to set your %s variable to at least "
6179   "%d and retry the command.");
6180
6181void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
6182{
6183        fflush(stdout);
6184        if (degraded_cc)
6185                warning(_(degrade_cc_to_c_warning));
6186        else if (needed)
6187                warning(_(rename_limit_warning));
6188        else
6189                return;
6190        if (0 < needed)
6191                warning(_(rename_limit_advice), varname, needed);
6192}
6193
6194static void diff_flush_patch_all_file_pairs(struct diff_options *o)
6195{
6196        int i;
6197        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
6198        struct diff_queue_struct *q = &diff_queued_diff;
6199
6200        if (WSEH_NEW & WS_RULE_MASK)
6201                BUG("WS rules bit mask overlaps with diff symbol flags");
6202
6203        if (o->color_moved)
6204                o->emitted_symbols = &esm;
6205
6206        for (i = 0; i < q->nr; i++) {
6207                struct diff_filepair *p = q->queue[i];
6208                if (check_pair_status(p))
6209                        diff_flush_patch(p, o);
6210        }
6211
6212        if (o->emitted_symbols) {
6213                if (o->color_moved) {
6214                        struct hashmap add_lines, del_lines;
6215
6216                        if (o->color_moved_ws_handling &
6217                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
6218                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
6219
6220                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
6221                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
6222
6223                        add_lines_to_move_detection(o, &add_lines, &del_lines);
6224                        mark_color_as_moved(o, &add_lines, &del_lines);
6225                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
6226                                dim_moved_lines(o);
6227
6228                        hashmap_free(&add_lines, 1);
6229                        hashmap_free(&del_lines, 1);
6230                }
6231
6232                for (i = 0; i < esm.nr; i++)
6233                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
6234
6235                for (i = 0; i < esm.nr; i++)
6236                        free((void *)esm.buf[i].line);
6237                esm.nr = 0;
6238
6239                o->emitted_symbols = NULL;
6240        }
6241}
6242
6243void diff_flush(struct diff_options *options)
6244{
6245        struct diff_queue_struct *q = &diff_queued_diff;
6246        int i, output_format = options->output_format;
6247        int separator = 0;
6248        int dirstat_by_line = 0;
6249
6250        /*
6251         * Order: raw, stat, summary, patch
6252         * or:    name/name-status/checkdiff (other bits clear)
6253         */
6254        if (!q->nr)
6255                goto free_queue;
6256
6257        if (output_format & (DIFF_FORMAT_RAW |
6258                             DIFF_FORMAT_NAME |
6259                             DIFF_FORMAT_NAME_STATUS |
6260                             DIFF_FORMAT_CHECKDIFF)) {
6261                for (i = 0; i < q->nr; i++) {
6262                        struct diff_filepair *p = q->queue[i];
6263                        if (check_pair_status(p))
6264                                flush_one_pair(p, options);
6265                }
6266                separator++;
6267        }
6268
6269        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
6270                dirstat_by_line = 1;
6271
6272        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
6273            dirstat_by_line) {
6274                struct diffstat_t diffstat;
6275
6276                memset(&diffstat, 0, sizeof(struct diffstat_t));
6277                for (i = 0; i < q->nr; i++) {
6278                        struct diff_filepair *p = q->queue[i];
6279                        if (check_pair_status(p))
6280                                diff_flush_stat(p, options, &diffstat);
6281                }
6282                if (output_format & DIFF_FORMAT_NUMSTAT)
6283                        show_numstat(&diffstat, options);
6284                if (output_format & DIFF_FORMAT_DIFFSTAT)
6285                        show_stats(&diffstat, options);
6286                if (output_format & DIFF_FORMAT_SHORTSTAT)
6287                        show_shortstats(&diffstat, options);
6288                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
6289                        show_dirstat_by_line(&diffstat, options);
6290                free_diffstat_info(&diffstat);
6291                separator++;
6292        }
6293        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
6294                show_dirstat(options);
6295
6296        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
6297                for (i = 0; i < q->nr; i++) {
6298                        diff_summary(options, q->queue[i]);
6299                }
6300                separator++;
6301        }
6302
6303        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
6304            options->flags.exit_with_status &&
6305            options->flags.diff_from_contents) {
6306                /*
6307                 * run diff_flush_patch for the exit status. setting
6308                 * options->file to /dev/null should be safe, because we
6309                 * aren't supposed to produce any output anyway.
6310                 */
6311                if (options->close_file)
6312                        fclose(options->file);
6313                options->file = xfopen("/dev/null", "w");
6314                options->close_file = 1;
6315                options->color_moved = 0;
6316                for (i = 0; i < q->nr; i++) {
6317                        struct diff_filepair *p = q->queue[i];
6318                        if (check_pair_status(p))
6319                                diff_flush_patch(p, options);
6320                        if (options->found_changes)
6321                                break;
6322                }
6323        }
6324
6325        if (output_format & DIFF_FORMAT_PATCH) {
6326                if (separator) {
6327                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
6328                        if (options->stat_sep)
6329                                /* attach patch instead of inline */
6330                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
6331                                                 NULL, 0, 0);
6332                }
6333
6334                diff_flush_patch_all_file_pairs(options);
6335        }
6336
6337        if (output_format & DIFF_FORMAT_CALLBACK)
6338                options->format_callback(q, options, options->format_callback_data);
6339
6340        for (i = 0; i < q->nr; i++)
6341                diff_free_filepair(q->queue[i]);
6342free_queue:
6343        free(q->queue);
6344        DIFF_QUEUE_CLEAR(q);
6345        if (options->close_file)
6346                fclose(options->file);
6347
6348        /*
6349         * Report the content-level differences with HAS_CHANGES;
6350         * diff_addremove/diff_change does not set the bit when
6351         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
6352         */
6353        if (options->flags.diff_from_contents) {
6354                if (options->found_changes)
6355                        options->flags.has_changes = 1;
6356                else
6357                        options->flags.has_changes = 0;
6358        }
6359}
6360
6361static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
6362{
6363        return (((p->status == DIFF_STATUS_MODIFIED) &&
6364                 ((p->score &&
6365                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
6366                  (!p->score &&
6367                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
6368                ((p->status != DIFF_STATUS_MODIFIED) &&
6369                 filter_bit_tst(p->status, options)));
6370}
6371
6372static void diffcore_apply_filter(struct diff_options *options)
6373{
6374        int i;
6375        struct diff_queue_struct *q = &diff_queued_diff;
6376        struct diff_queue_struct outq;
6377
6378        DIFF_QUEUE_CLEAR(&outq);
6379
6380        if (!options->filter)
6381                return;
6382
6383        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
6384                int found;
6385                for (i = found = 0; !found && i < q->nr; i++) {
6386                        if (match_filter(options, q->queue[i]))
6387                                found++;
6388                }
6389                if (found)
6390                        return;
6391
6392                /* otherwise we will clear the whole queue
6393                 * by copying the empty outq at the end of this
6394                 * function, but first clear the current entries
6395                 * in the queue.
6396                 */
6397                for (i = 0; i < q->nr; i++)
6398                        diff_free_filepair(q->queue[i]);
6399        }
6400        else {
6401                /* Only the matching ones */
6402                for (i = 0; i < q->nr; i++) {
6403                        struct diff_filepair *p = q->queue[i];
6404                        if (match_filter(options, p))
6405                                diff_q(&outq, p);
6406                        else
6407                                diff_free_filepair(p);
6408                }
6409        }
6410        free(q->queue);
6411        *q = outq;
6412}
6413
6414/* Check whether two filespecs with the same mode and size are identical */
6415static int diff_filespec_is_identical(struct repository *r,
6416                                      struct diff_filespec *one,
6417                                      struct diff_filespec *two)
6418{
6419        if (S_ISGITLINK(one->mode))
6420                return 0;
6421        if (diff_populate_filespec(r, one, 0))
6422                return 0;
6423        if (diff_populate_filespec(r, two, 0))
6424                return 0;
6425        return !memcmp(one->data, two->data, one->size);
6426}
6427
6428static int diff_filespec_check_stat_unmatch(struct repository *r,
6429                                            struct diff_filepair *p)
6430{
6431        if (p->done_skip_stat_unmatch)
6432                return p->skip_stat_unmatch_result;
6433
6434        p->done_skip_stat_unmatch = 1;
6435        p->skip_stat_unmatch_result = 0;
6436        /*
6437         * 1. Entries that come from stat info dirtiness
6438         *    always have both sides (iow, not create/delete),
6439         *    one side of the object name is unknown, with
6440         *    the same mode and size.  Keep the ones that
6441         *    do not match these criteria.  They have real
6442         *    differences.
6443         *
6444         * 2. At this point, the file is known to be modified,
6445         *    with the same mode and size, and the object
6446         *    name of one side is unknown.  Need to inspect
6447         *    the identical contents.
6448         */
6449        if (!DIFF_FILE_VALID(p->one) || /* (1) */
6450            !DIFF_FILE_VALID(p->two) ||
6451            (p->one->oid_valid && p->two->oid_valid) ||
6452            (p->one->mode != p->two->mode) ||
6453            diff_populate_filespec(r, p->one, CHECK_SIZE_ONLY) ||
6454            diff_populate_filespec(r, p->two, CHECK_SIZE_ONLY) ||
6455            (p->one->size != p->two->size) ||
6456            !diff_filespec_is_identical(r, p->one, p->two)) /* (2) */
6457                p->skip_stat_unmatch_result = 1;
6458        return p->skip_stat_unmatch_result;
6459}
6460
6461static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
6462{
6463        int i;
6464        struct diff_queue_struct *q = &diff_queued_diff;
6465        struct diff_queue_struct outq;
6466        DIFF_QUEUE_CLEAR(&outq);
6467
6468        for (i = 0; i < q->nr; i++) {
6469                struct diff_filepair *p = q->queue[i];
6470
6471                if (diff_filespec_check_stat_unmatch(diffopt->repo, p))
6472                        diff_q(&outq, p);
6473                else {
6474                        /*
6475                         * The caller can subtract 1 from skip_stat_unmatch
6476                         * to determine how many paths were dirty only
6477                         * due to stat info mismatch.
6478                         */
6479                        if (!diffopt->flags.no_index)
6480                                diffopt->skip_stat_unmatch++;
6481                        diff_free_filepair(p);
6482                }
6483        }
6484        free(q->queue);
6485        *q = outq;
6486}
6487
6488static int diffnamecmp(const void *a_, const void *b_)
6489{
6490        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6491        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6492        const char *name_a, *name_b;
6493
6494        name_a = a->one ? a->one->path : a->two->path;
6495        name_b = b->one ? b->one->path : b->two->path;
6496        return strcmp(name_a, name_b);
6497}
6498
6499void diffcore_fix_diff_index(void)
6500{
6501        struct diff_queue_struct *q = &diff_queued_diff;
6502        QSORT(q->queue, q->nr, diffnamecmp);
6503}
6504
6505static void add_if_missing(struct repository *r,
6506                           struct oid_array *to_fetch,
6507                           const struct diff_filespec *filespec)
6508{
6509        if (filespec && filespec->oid_valid &&
6510            oid_object_info_extended(r, &filespec->oid, NULL,
6511                                     OBJECT_INFO_FOR_PREFETCH))
6512                oid_array_append(to_fetch, &filespec->oid);
6513}
6514
6515void diffcore_std(struct diff_options *options)
6516{
6517        if (options->repo == the_repository &&
6518            repository_format_partial_clone) {
6519                /*
6520                 * Prefetch the diff pairs that are about to be flushed.
6521                 */
6522                int i;
6523                struct diff_queue_struct *q = &diff_queued_diff;
6524                struct oid_array to_fetch = OID_ARRAY_INIT;
6525
6526                for (i = 0; i < q->nr; i++) {
6527                        struct diff_filepair *p = q->queue[i];
6528                        add_if_missing(options->repo, &to_fetch, p->one);
6529                        add_if_missing(options->repo, &to_fetch, p->two);
6530                }
6531                if (to_fetch.nr)
6532                        /*
6533                         * NEEDSWORK: Consider deduplicating the OIDs sent.
6534                         */
6535                        fetch_objects(repository_format_partial_clone,
6536                                      to_fetch.oid, to_fetch.nr);
6537                oid_array_clear(&to_fetch);
6538        }
6539
6540        /* NOTE please keep the following in sync with diff_tree_combined() */
6541        if (options->skip_stat_unmatch)
6542                diffcore_skip_stat_unmatch(options);
6543        if (!options->found_follow) {
6544                /* See try_to_follow_renames() in tree-diff.c */
6545                if (options->break_opt != -1)
6546                        diffcore_break(options->repo,
6547                                       options->break_opt);
6548                if (options->detect_rename)
6549                        diffcore_rename(options);
6550                if (options->break_opt != -1)
6551                        diffcore_merge_broken();
6552        }
6553        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6554                diffcore_pickaxe(options);
6555        if (options->orderfile)
6556                diffcore_order(options->orderfile);
6557        if (!options->found_follow)
6558                /* See try_to_follow_renames() in tree-diff.c */
6559                diff_resolve_rename_copy();
6560        diffcore_apply_filter(options);
6561
6562        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6563                options->flags.has_changes = 1;
6564        else
6565                options->flags.has_changes = 0;
6566
6567        options->found_follow = 0;
6568}
6569
6570int diff_result_code(struct diff_options *opt, int status)
6571{
6572        int result = 0;
6573
6574        diff_warn_rename_limit("diff.renameLimit",
6575                               opt->needed_rename_limit,
6576                               opt->degraded_cc_to_c);
6577        if (!opt->flags.exit_with_status &&
6578            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6579                return status;
6580        if (opt->flags.exit_with_status &&
6581            opt->flags.has_changes)
6582                result |= 01;
6583        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6584            opt->flags.check_failed)
6585                result |= 02;
6586        return result;
6587}
6588
6589int diff_can_quit_early(struct diff_options *opt)
6590{
6591        return (opt->flags.quick &&
6592                !opt->filter &&
6593                opt->flags.has_changes);
6594}
6595
6596/*
6597 * Shall changes to this submodule be ignored?
6598 *
6599 * Submodule changes can be configured to be ignored separately for each path,
6600 * but that configuration can be overridden from the command line.
6601 */
6602static int is_submodule_ignored(const char *path, struct diff_options *options)
6603{
6604        int ignored = 0;
6605        struct diff_flags orig_flags = options->flags;
6606        if (!options->flags.override_submodule_config)
6607                set_diffopt_flags_from_submodule_config(options, path);
6608        if (options->flags.ignore_submodules)
6609                ignored = 1;
6610        options->flags = orig_flags;
6611        return ignored;
6612}
6613
6614void diff_addremove(struct diff_options *options,
6615                    int addremove, unsigned mode,
6616                    const struct object_id *oid,
6617                    int oid_valid,
6618                    const char *concatpath, unsigned dirty_submodule)
6619{
6620        struct diff_filespec *one, *two;
6621
6622        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6623                return;
6624
6625        /* This may look odd, but it is a preparation for
6626         * feeding "there are unchanged files which should
6627         * not produce diffs, but when you are doing copy
6628         * detection you would need them, so here they are"
6629         * entries to the diff-core.  They will be prefixed
6630         * with something like '=' or '*' (I haven't decided
6631         * which but should not make any difference).
6632         * Feeding the same new and old to diff_change()
6633         * also has the same effect.
6634         * Before the final output happens, they are pruned after
6635         * merged into rename/copy pairs as appropriate.
6636         */
6637        if (options->flags.reverse_diff)
6638                addremove = (addremove == '+' ? '-' :
6639                             addremove == '-' ? '+' : addremove);
6640
6641        if (options->prefix &&
6642            strncmp(concatpath, options->prefix, options->prefix_length))
6643                return;
6644
6645        one = alloc_filespec(concatpath);
6646        two = alloc_filespec(concatpath);
6647
6648        if (addremove != '+')
6649                fill_filespec(one, oid, oid_valid, mode);
6650        if (addremove != '-') {
6651                fill_filespec(two, oid, oid_valid, mode);
6652                two->dirty_submodule = dirty_submodule;
6653        }
6654
6655        diff_queue(&diff_queued_diff, one, two);
6656        if (!options->flags.diff_from_contents)
6657                options->flags.has_changes = 1;
6658}
6659
6660void diff_change(struct diff_options *options,
6661                 unsigned old_mode, unsigned new_mode,
6662                 const struct object_id *old_oid,
6663                 const struct object_id *new_oid,
6664                 int old_oid_valid, int new_oid_valid,
6665                 const char *concatpath,
6666                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6667{
6668        struct diff_filespec *one, *two;
6669        struct diff_filepair *p;
6670
6671        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6672            is_submodule_ignored(concatpath, options))
6673                return;
6674
6675        if (options->flags.reverse_diff) {
6676                SWAP(old_mode, new_mode);
6677                SWAP(old_oid, new_oid);
6678                SWAP(old_oid_valid, new_oid_valid);
6679                SWAP(old_dirty_submodule, new_dirty_submodule);
6680        }
6681
6682        if (options->prefix &&
6683            strncmp(concatpath, options->prefix, options->prefix_length))
6684                return;
6685
6686        one = alloc_filespec(concatpath);
6687        two = alloc_filespec(concatpath);
6688        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6689        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6690        one->dirty_submodule = old_dirty_submodule;
6691        two->dirty_submodule = new_dirty_submodule;
6692        p = diff_queue(&diff_queued_diff, one, two);
6693
6694        if (options->flags.diff_from_contents)
6695                return;
6696
6697        if (options->flags.quick && options->skip_stat_unmatch &&
6698            !diff_filespec_check_stat_unmatch(options->repo, p))
6699                return;
6700
6701        options->flags.has_changes = 1;
6702}
6703
6704struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6705{
6706        struct diff_filepair *pair;
6707        struct diff_filespec *one, *two;
6708
6709        if (options->prefix &&
6710            strncmp(path, options->prefix, options->prefix_length))
6711                return NULL;
6712
6713        one = alloc_filespec(path);
6714        two = alloc_filespec(path);
6715        pair = diff_queue(&diff_queued_diff, one, two);
6716        pair->is_unmerged = 1;
6717        return pair;
6718}
6719
6720static char *run_textconv(struct repository *r,
6721                          const char *pgm,
6722                          struct diff_filespec *spec,
6723                          size_t *outsize)
6724{
6725        struct diff_tempfile *temp;
6726        const char *argv[3];
6727        const char **arg = argv;
6728        struct child_process child = CHILD_PROCESS_INIT;
6729        struct strbuf buf = STRBUF_INIT;
6730        int err = 0;
6731
6732        temp = prepare_temp_file(r, spec->path, spec);
6733        *arg++ = pgm;
6734        *arg++ = temp->name;
6735        *arg = NULL;
6736
6737        child.use_shell = 1;
6738        child.argv = argv;
6739        child.out = -1;
6740        if (start_command(&child)) {
6741                remove_tempfile();
6742                return NULL;
6743        }
6744
6745        if (strbuf_read(&buf, child.out, 0) < 0)
6746                err = error("error reading from textconv command '%s'", pgm);
6747        close(child.out);
6748
6749        if (finish_command(&child) || err) {
6750                strbuf_release(&buf);
6751                remove_tempfile();
6752                return NULL;
6753        }
6754        remove_tempfile();
6755
6756        return strbuf_detach(&buf, outsize);
6757}
6758
6759size_t fill_textconv(struct repository *r,
6760                     struct userdiff_driver *driver,
6761                     struct diff_filespec *df,
6762                     char **outbuf)
6763{
6764        size_t size;
6765
6766        if (!driver) {
6767                if (!DIFF_FILE_VALID(df)) {
6768                        *outbuf = "";
6769                        return 0;
6770                }
6771                if (diff_populate_filespec(r, df, 0))
6772                        die("unable to read files to diff");
6773                *outbuf = df->data;
6774                return df->size;
6775        }
6776
6777        if (!driver->textconv)
6778                BUG("fill_textconv called with non-textconv driver");
6779
6780        if (driver->textconv_cache && df->oid_valid) {
6781                *outbuf = notes_cache_get(driver->textconv_cache,
6782                                          &df->oid,
6783                                          &size);
6784                if (*outbuf)
6785                        return size;
6786        }
6787
6788        *outbuf = run_textconv(r, driver->textconv, df, &size);
6789        if (!*outbuf)
6790                die("unable to read files to diff");
6791
6792        if (driver->textconv_cache && df->oid_valid) {
6793                /* ignore errors, as we might be in a readonly repository */
6794                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6795                                size);
6796                /*
6797                 * we could save up changes and flush them all at the end,
6798                 * but we would need an extra call after all diffing is done.
6799                 * Since generating a cache entry is the slow path anyway,
6800                 * this extra overhead probably isn't a big deal.
6801                 */
6802                notes_cache_write(driver->textconv_cache);
6803        }
6804
6805        return size;
6806}
6807
6808int textconv_object(struct repository *r,
6809                    const char *path,
6810                    unsigned mode,
6811                    const struct object_id *oid,
6812                    int oid_valid,
6813                    char **buf,
6814                    unsigned long *buf_size)
6815{
6816        struct diff_filespec *df;
6817        struct userdiff_driver *textconv;
6818
6819        df = alloc_filespec(path);
6820        fill_filespec(df, oid, oid_valid, mode);
6821        textconv = get_textconv(r, df);
6822        if (!textconv) {
6823                free_filespec(df);
6824                return 0;
6825        }
6826
6827        *buf_size = fill_textconv(r, textconv, df, buf);
6828        free_filespec(df);
6829        return 1;
6830}
6831
6832void setup_diff_pager(struct diff_options *opt)
6833{
6834        /*
6835         * If the user asked for our exit code, then either they want --quiet
6836         * or --exit-code. We should definitely not bother with a pager in the
6837         * former case, as we will generate no output. Since we still properly
6838         * report our exit code even when a pager is run, we _could_ run a
6839         * pager with --exit-code. But since we have not done so historically,
6840         * and because it is easy to find people oneline advising "git diff
6841         * --exit-code" in hooks and other scripts, we do not do so.
6842         */
6843        if (!opt->flags.exit_with_status &&
6844            check_pager_config("diff") != 0)
6845                setup_pager();
6846}