diff.con commit Merge branch 'kg/external-diff-save-env' (6a015ce)
   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 "help.h"
  27
  28#ifdef NO_FAST_WORKING_DIRECTORY
  29#define FAST_WORKING_DIRECTORY 0
  30#else
  31#define FAST_WORKING_DIRECTORY 1
  32#endif
  33
  34static int diff_detect_rename_default;
  35static int diff_indent_heuristic = 1;
  36static int diff_rename_limit_default = 400;
  37static int diff_suppress_blank_empty;
  38static int diff_use_color_default = -1;
  39static int diff_color_moved_default;
  40static int diff_color_moved_ws_default;
  41static int diff_context_default = 3;
  42static int diff_interhunk_context_default;
  43static const char *diff_word_regex_cfg;
  44static const char *external_diff_cmd_cfg;
  45static const char *diff_order_file_cfg;
  46int diff_auto_refresh_index = 1;
  47static int diff_mnemonic_prefix;
  48static int diff_no_prefix;
  49static int diff_stat_graph_width;
  50static int diff_dirstat_permille_default = 30;
  51static struct diff_options default_diff_options;
  52static long diff_algorithm;
  53static unsigned ws_error_highlight_default = WSEH_NEW;
  54
  55static char diff_colors[][COLOR_MAXLEN] = {
  56        GIT_COLOR_RESET,
  57        GIT_COLOR_NORMAL,       /* CONTEXT */
  58        GIT_COLOR_BOLD,         /* METAINFO */
  59        GIT_COLOR_CYAN,         /* FRAGINFO */
  60        GIT_COLOR_RED,          /* OLD */
  61        GIT_COLOR_GREEN,        /* NEW */
  62        GIT_COLOR_YELLOW,       /* COMMIT */
  63        GIT_COLOR_BG_RED,       /* WHITESPACE */
  64        GIT_COLOR_NORMAL,       /* FUNCINFO */
  65        GIT_COLOR_BOLD_MAGENTA, /* OLD_MOVED */
  66        GIT_COLOR_BOLD_BLUE,    /* OLD_MOVED ALTERNATIVE */
  67        GIT_COLOR_FAINT,        /* OLD_MOVED_DIM */
  68        GIT_COLOR_FAINT_ITALIC, /* OLD_MOVED_ALTERNATIVE_DIM */
  69        GIT_COLOR_BOLD_CYAN,    /* NEW_MOVED */
  70        GIT_COLOR_BOLD_YELLOW,  /* NEW_MOVED ALTERNATIVE */
  71        GIT_COLOR_FAINT,        /* NEW_MOVED_DIM */
  72        GIT_COLOR_FAINT_ITALIC, /* NEW_MOVED_ALTERNATIVE_DIM */
  73        GIT_COLOR_FAINT,        /* CONTEXT_DIM */
  74        GIT_COLOR_FAINT_RED,    /* OLD_DIM */
  75        GIT_COLOR_FAINT_GREEN,  /* NEW_DIM */
  76        GIT_COLOR_BOLD,         /* CONTEXT_BOLD */
  77        GIT_COLOR_BOLD_RED,     /* OLD_BOLD */
  78        GIT_COLOR_BOLD_GREEN,   /* NEW_BOLD */
  79};
  80
  81static const char *color_diff_slots[] = {
  82        [DIFF_CONTEXT]                = "context",
  83        [DIFF_METAINFO]               = "meta",
  84        [DIFF_FRAGINFO]               = "frag",
  85        [DIFF_FILE_OLD]               = "old",
  86        [DIFF_FILE_NEW]               = "new",
  87        [DIFF_COMMIT]                 = "commit",
  88        [DIFF_WHITESPACE]             = "whitespace",
  89        [DIFF_FUNCINFO]               = "func",
  90        [DIFF_FILE_OLD_MOVED]         = "oldMoved",
  91        [DIFF_FILE_OLD_MOVED_ALT]     = "oldMovedAlternative",
  92        [DIFF_FILE_OLD_MOVED_DIM]     = "oldMovedDimmed",
  93        [DIFF_FILE_OLD_MOVED_ALT_DIM] = "oldMovedAlternativeDimmed",
  94        [DIFF_FILE_NEW_MOVED]         = "newMoved",
  95        [DIFF_FILE_NEW_MOVED_ALT]     = "newMovedAlternative",
  96        [DIFF_FILE_NEW_MOVED_DIM]     = "newMovedDimmed",
  97        [DIFF_FILE_NEW_MOVED_ALT_DIM] = "newMovedAlternativeDimmed",
  98        [DIFF_CONTEXT_DIM]            = "contextDimmed",
  99        [DIFF_FILE_OLD_DIM]           = "oldDimmed",
 100        [DIFF_FILE_NEW_DIM]           = "newDimmed",
 101        [DIFF_CONTEXT_BOLD]           = "contextBold",
 102        [DIFF_FILE_OLD_BOLD]          = "oldBold",
 103        [DIFF_FILE_NEW_BOLD]          = "newBold",
 104};
 105
 106static NORETURN void die_want_option(const char *option_name)
 107{
 108        die(_("option '%s' requires a value"), option_name);
 109}
 110
 111define_list_config_array_extra(color_diff_slots, {"plain"});
 112
 113static int parse_diff_color_slot(const char *var)
 114{
 115        if (!strcasecmp(var, "plain"))
 116                return DIFF_CONTEXT;
 117        return LOOKUP_CONFIG(color_diff_slots, var);
 118}
 119
 120static int parse_dirstat_params(struct diff_options *options, const char *params_string,
 121                                struct strbuf *errmsg)
 122{
 123        char *params_copy = xstrdup(params_string);
 124        struct string_list params = STRING_LIST_INIT_NODUP;
 125        int ret = 0;
 126        int i;
 127
 128        if (*params_copy)
 129                string_list_split_in_place(&params, params_copy, ',', -1);
 130        for (i = 0; i < params.nr; i++) {
 131                const char *p = params.items[i].string;
 132                if (!strcmp(p, "changes")) {
 133                        options->flags.dirstat_by_line = 0;
 134                        options->flags.dirstat_by_file = 0;
 135                } else if (!strcmp(p, "lines")) {
 136                        options->flags.dirstat_by_line = 1;
 137                        options->flags.dirstat_by_file = 0;
 138                } else if (!strcmp(p, "files")) {
 139                        options->flags.dirstat_by_line = 0;
 140                        options->flags.dirstat_by_file = 1;
 141                } else if (!strcmp(p, "noncumulative")) {
 142                        options->flags.dirstat_cumulative = 0;
 143                } else if (!strcmp(p, "cumulative")) {
 144                        options->flags.dirstat_cumulative = 1;
 145                } else if (isdigit(*p)) {
 146                        char *end;
 147                        int permille = strtoul(p, &end, 10) * 10;
 148                        if (*end == '.' && isdigit(*++end)) {
 149                                /* only use first digit */
 150                                permille += *end - '0';
 151                                /* .. and ignore any further digits */
 152                                while (isdigit(*++end))
 153                                        ; /* nothing */
 154                        }
 155                        if (!*end)
 156                                options->dirstat_permille = permille;
 157                        else {
 158                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 159                                            p);
 160                                ret++;
 161                        }
 162                } else {
 163                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 164                        ret++;
 165                }
 166
 167        }
 168        string_list_clear(&params, 0);
 169        free(params_copy);
 170        return ret;
 171}
 172
 173static int parse_submodule_params(struct diff_options *options, const char *value)
 174{
 175        if (!strcmp(value, "log"))
 176                options->submodule_format = DIFF_SUBMODULE_LOG;
 177        else if (!strcmp(value, "short"))
 178                options->submodule_format = DIFF_SUBMODULE_SHORT;
 179        else if (!strcmp(value, "diff"))
 180                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 181        else
 182                return -1;
 183        return 0;
 184}
 185
 186int git_config_rename(const char *var, const char *value)
 187{
 188        if (!value)
 189                return DIFF_DETECT_RENAME;
 190        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 191                return  DIFF_DETECT_COPY;
 192        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 193}
 194
 195long parse_algorithm_value(const char *value)
 196{
 197        if (!value)
 198                return -1;
 199        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 200                return 0;
 201        else if (!strcasecmp(value, "minimal"))
 202                return XDF_NEED_MINIMAL;
 203        else if (!strcasecmp(value, "patience"))
 204                return XDF_PATIENCE_DIFF;
 205        else if (!strcasecmp(value, "histogram"))
 206                return XDF_HISTOGRAM_DIFF;
 207        return -1;
 208}
 209
 210static int parse_one_token(const char **arg, const char *token)
 211{
 212        const char *rest;
 213        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 214                *arg = rest;
 215                return 1;
 216        }
 217        return 0;
 218}
 219
 220static int parse_ws_error_highlight(const char *arg)
 221{
 222        const char *orig_arg = arg;
 223        unsigned val = 0;
 224
 225        while (*arg) {
 226                if (parse_one_token(&arg, "none"))
 227                        val = 0;
 228                else if (parse_one_token(&arg, "default"))
 229                        val = WSEH_NEW;
 230                else if (parse_one_token(&arg, "all"))
 231                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 232                else if (parse_one_token(&arg, "new"))
 233                        val |= WSEH_NEW;
 234                else if (parse_one_token(&arg, "old"))
 235                        val |= WSEH_OLD;
 236                else if (parse_one_token(&arg, "context"))
 237                        val |= WSEH_CONTEXT;
 238                else {
 239                        return -1 - (int)(arg - orig_arg);
 240                }
 241                if (*arg)
 242                        arg++;
 243        }
 244        return val;
 245}
 246
 247/*
 248 * These are to give UI layer defaults.
 249 * The core-level commands such as git-diff-files should
 250 * never be affected by the setting of diff.renames
 251 * the user happens to have in the configuration file.
 252 */
 253void init_diff_ui_defaults(void)
 254{
 255        diff_detect_rename_default = DIFF_DETECT_RENAME;
 256}
 257
 258int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 259{
 260        if (!strcmp(var, "diff.indentheuristic"))
 261                diff_indent_heuristic = git_config_bool(var, value);
 262        return 0;
 263}
 264
 265static int parse_color_moved(const char *arg)
 266{
 267        switch (git_parse_maybe_bool(arg)) {
 268        case 0:
 269                return COLOR_MOVED_NO;
 270        case 1:
 271                return COLOR_MOVED_DEFAULT;
 272        default:
 273                break;
 274        }
 275
 276        if (!strcmp(arg, "no"))
 277                return COLOR_MOVED_NO;
 278        else if (!strcmp(arg, "plain"))
 279                return COLOR_MOVED_PLAIN;
 280        else if (!strcmp(arg, "blocks"))
 281                return COLOR_MOVED_BLOCKS;
 282        else if (!strcmp(arg, "zebra"))
 283                return COLOR_MOVED_ZEBRA;
 284        else if (!strcmp(arg, "default"))
 285                return COLOR_MOVED_DEFAULT;
 286        else if (!strcmp(arg, "dimmed-zebra"))
 287                return COLOR_MOVED_ZEBRA_DIM;
 288        else if (!strcmp(arg, "dimmed_zebra"))
 289                return COLOR_MOVED_ZEBRA_DIM;
 290        else
 291                return error(_("color moved setting must be one of 'no', 'default', 'blocks', 'zebra', 'dimmed-zebra', 'plain'"));
 292}
 293
 294static unsigned parse_color_moved_ws(const char *arg)
 295{
 296        int ret = 0;
 297        struct string_list l = STRING_LIST_INIT_DUP;
 298        struct string_list_item *i;
 299
 300        string_list_split(&l, arg, ',', -1);
 301
 302        for_each_string_list_item(i, &l) {
 303                struct strbuf sb = STRBUF_INIT;
 304                strbuf_addstr(&sb, i->string);
 305                strbuf_trim(&sb);
 306
 307                if (!strcmp(sb.buf, "ignore-space-change"))
 308                        ret |= XDF_IGNORE_WHITESPACE_CHANGE;
 309                else if (!strcmp(sb.buf, "ignore-space-at-eol"))
 310                        ret |= XDF_IGNORE_WHITESPACE_AT_EOL;
 311                else if (!strcmp(sb.buf, "ignore-all-space"))
 312                        ret |= XDF_IGNORE_WHITESPACE;
 313                else if (!strcmp(sb.buf, "allow-indentation-change"))
 314                        ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
 315                else {
 316                        ret |= COLOR_MOVED_WS_ERROR;
 317                        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);
 318                }
 319
 320                strbuf_release(&sb);
 321        }
 322
 323        if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
 324            (ret & XDF_WHITESPACE_FLAGS)) {
 325                error(_("color-moved-ws: allow-indentation-change cannot be combined with other white space modes"));
 326                ret |= COLOR_MOVED_WS_ERROR;
 327        }
 328
 329        string_list_clear(&l, 0);
 330
 331        return ret;
 332}
 333
 334int git_diff_ui_config(const char *var, const char *value, void *cb)
 335{
 336        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 337                diff_use_color_default = git_config_colorbool(var, value);
 338                return 0;
 339        }
 340        if (!strcmp(var, "diff.colormoved")) {
 341                int cm = parse_color_moved(value);
 342                if (cm < 0)
 343                        return -1;
 344                diff_color_moved_default = cm;
 345                return 0;
 346        }
 347        if (!strcmp(var, "diff.colormovedws")) {
 348                unsigned cm = parse_color_moved_ws(value);
 349                if (cm & COLOR_MOVED_WS_ERROR)
 350                        return -1;
 351                diff_color_moved_ws_default = cm;
 352                return 0;
 353        }
 354        if (!strcmp(var, "diff.context")) {
 355                diff_context_default = git_config_int(var, value);
 356                if (diff_context_default < 0)
 357                        return -1;
 358                return 0;
 359        }
 360        if (!strcmp(var, "diff.interhunkcontext")) {
 361                diff_interhunk_context_default = git_config_int(var, value);
 362                if (diff_interhunk_context_default < 0)
 363                        return -1;
 364                return 0;
 365        }
 366        if (!strcmp(var, "diff.renames")) {
 367                diff_detect_rename_default = git_config_rename(var, value);
 368                return 0;
 369        }
 370        if (!strcmp(var, "diff.autorefreshindex")) {
 371                diff_auto_refresh_index = git_config_bool(var, value);
 372                return 0;
 373        }
 374        if (!strcmp(var, "diff.mnemonicprefix")) {
 375                diff_mnemonic_prefix = git_config_bool(var, value);
 376                return 0;
 377        }
 378        if (!strcmp(var, "diff.noprefix")) {
 379                diff_no_prefix = git_config_bool(var, value);
 380                return 0;
 381        }
 382        if (!strcmp(var, "diff.statgraphwidth")) {
 383                diff_stat_graph_width = git_config_int(var, value);
 384                return 0;
 385        }
 386        if (!strcmp(var, "diff.external"))
 387                return git_config_string(&external_diff_cmd_cfg, var, value);
 388        if (!strcmp(var, "diff.wordregex"))
 389                return git_config_string(&diff_word_regex_cfg, var, value);
 390        if (!strcmp(var, "diff.orderfile"))
 391                return git_config_pathname(&diff_order_file_cfg, var, value);
 392
 393        if (!strcmp(var, "diff.ignoresubmodules"))
 394                handle_ignore_submodules_arg(&default_diff_options, value);
 395
 396        if (!strcmp(var, "diff.submodule")) {
 397                if (parse_submodule_params(&default_diff_options, value))
 398                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 399                                value);
 400                return 0;
 401        }
 402
 403        if (!strcmp(var, "diff.algorithm")) {
 404                diff_algorithm = parse_algorithm_value(value);
 405                if (diff_algorithm < 0)
 406                        return -1;
 407                return 0;
 408        }
 409
 410        if (!strcmp(var, "diff.wserrorhighlight")) {
 411                int val = parse_ws_error_highlight(value);
 412                if (val < 0)
 413                        return -1;
 414                ws_error_highlight_default = val;
 415                return 0;
 416        }
 417
 418        if (git_color_config(var, value, cb) < 0)
 419                return -1;
 420
 421        return git_diff_basic_config(var, value, cb);
 422}
 423
 424int git_diff_basic_config(const char *var, const char *value, void *cb)
 425{
 426        const char *name;
 427
 428        if (!strcmp(var, "diff.renamelimit")) {
 429                diff_rename_limit_default = git_config_int(var, value);
 430                return 0;
 431        }
 432
 433        if (userdiff_config(var, value) < 0)
 434                return -1;
 435
 436        if (skip_prefix(var, "diff.color.", &name) ||
 437            skip_prefix(var, "color.diff.", &name)) {
 438                int slot = parse_diff_color_slot(name);
 439                if (slot < 0)
 440                        return 0;
 441                if (!value)
 442                        return config_error_nonbool(var);
 443                return color_parse(value, diff_colors[slot]);
 444        }
 445
 446        /* like GNU diff's --suppress-blank-empty option  */
 447        if (!strcmp(var, "diff.suppressblankempty") ||
 448                        /* for backwards compatibility */
 449                        !strcmp(var, "diff.suppress-blank-empty")) {
 450                diff_suppress_blank_empty = git_config_bool(var, value);
 451                return 0;
 452        }
 453
 454        if (!strcmp(var, "diff.dirstat")) {
 455                struct strbuf errmsg = STRBUF_INIT;
 456                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 457                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 458                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 459                                errmsg.buf);
 460                strbuf_release(&errmsg);
 461                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 462                return 0;
 463        }
 464
 465        if (git_diff_heuristic_config(var, value, cb) < 0)
 466                return -1;
 467
 468        return git_default_config(var, value, cb);
 469}
 470
 471static char *quote_two(const char *one, const char *two)
 472{
 473        int need_one = quote_c_style(one, NULL, NULL, 1);
 474        int need_two = quote_c_style(two, NULL, NULL, 1);
 475        struct strbuf res = STRBUF_INIT;
 476
 477        if (need_one + need_two) {
 478                strbuf_addch(&res, '"');
 479                quote_c_style(one, &res, NULL, 1);
 480                quote_c_style(two, &res, NULL, 1);
 481                strbuf_addch(&res, '"');
 482        } else {
 483                strbuf_addstr(&res, one);
 484                strbuf_addstr(&res, two);
 485        }
 486        return strbuf_detach(&res, NULL);
 487}
 488
 489static const char *external_diff(void)
 490{
 491        static const char *external_diff_cmd = NULL;
 492        static int done_preparing = 0;
 493
 494        if (done_preparing)
 495                return external_diff_cmd;
 496        external_diff_cmd = xstrdup_or_null(getenv("GIT_EXTERNAL_DIFF"));
 497        if (!external_diff_cmd)
 498                external_diff_cmd = external_diff_cmd_cfg;
 499        done_preparing = 1;
 500        return external_diff_cmd;
 501}
 502
 503/*
 504 * Keep track of files used for diffing. Sometimes such an entry
 505 * refers to a temporary file, sometimes to an existing file, and
 506 * sometimes to "/dev/null".
 507 */
 508static struct diff_tempfile {
 509        /*
 510         * filename external diff should read from, or NULL if this
 511         * entry is currently not in use:
 512         */
 513        const char *name;
 514
 515        char hex[GIT_MAX_HEXSZ + 1];
 516        char mode[10];
 517
 518        /*
 519         * If this diff_tempfile instance refers to a temporary file,
 520         * this tempfile object is used to manage its lifetime.
 521         */
 522        struct tempfile *tempfile;
 523} diff_temp[2];
 524
 525struct emit_callback {
 526        int color_diff;
 527        unsigned ws_rule;
 528        int blank_at_eof_in_preimage;
 529        int blank_at_eof_in_postimage;
 530        int lno_in_preimage;
 531        int lno_in_postimage;
 532        const char **label_path;
 533        struct diff_words_data *diff_words;
 534        struct diff_options *opt;
 535        struct strbuf *header;
 536};
 537
 538static int count_lines(const char *data, int size)
 539{
 540        int count, ch, completely_empty = 1, nl_just_seen = 0;
 541        count = 0;
 542        while (0 < size--) {
 543                ch = *data++;
 544                if (ch == '\n') {
 545                        count++;
 546                        nl_just_seen = 1;
 547                        completely_empty = 0;
 548                }
 549                else {
 550                        nl_just_seen = 0;
 551                        completely_empty = 0;
 552                }
 553        }
 554        if (completely_empty)
 555                return 0;
 556        if (!nl_just_seen)
 557                count++; /* no trailing newline */
 558        return count;
 559}
 560
 561static int fill_mmfile(struct repository *r, mmfile_t *mf,
 562                       struct diff_filespec *one)
 563{
 564        if (!DIFF_FILE_VALID(one)) {
 565                mf->ptr = (char *)""; /* does not matter */
 566                mf->size = 0;
 567                return 0;
 568        }
 569        else if (diff_populate_filespec(r, one, 0))
 570                return -1;
 571
 572        mf->ptr = one->data;
 573        mf->size = one->size;
 574        return 0;
 575}
 576
 577/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 578static unsigned long diff_filespec_size(struct repository *r,
 579                                        struct diff_filespec *one)
 580{
 581        if (!DIFF_FILE_VALID(one))
 582                return 0;
 583        diff_populate_filespec(r, one, CHECK_SIZE_ONLY);
 584        return one->size;
 585}
 586
 587static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 588{
 589        char *ptr = mf->ptr;
 590        long size = mf->size;
 591        int cnt = 0;
 592
 593        if (!size)
 594                return cnt;
 595        ptr += size - 1; /* pointing at the very end */
 596        if (*ptr != '\n')
 597                ; /* incomplete line */
 598        else
 599                ptr--; /* skip the last LF */
 600        while (mf->ptr < ptr) {
 601                char *prev_eol;
 602                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 603                        if (*prev_eol == '\n')
 604                                break;
 605                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 606                        break;
 607                cnt++;
 608                ptr = prev_eol - 1;
 609        }
 610        return cnt;
 611}
 612
 613static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 614                               struct emit_callback *ecbdata)
 615{
 616        int l1, l2, at;
 617        unsigned ws_rule = ecbdata->ws_rule;
 618        l1 = count_trailing_blank(mf1, ws_rule);
 619        l2 = count_trailing_blank(mf2, ws_rule);
 620        if (l2 <= l1) {
 621                ecbdata->blank_at_eof_in_preimage = 0;
 622                ecbdata->blank_at_eof_in_postimage = 0;
 623                return;
 624        }
 625        at = count_lines(mf1->ptr, mf1->size);
 626        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 627
 628        at = count_lines(mf2->ptr, mf2->size);
 629        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 630}
 631
 632static void emit_line_0(struct diff_options *o,
 633                        const char *set_sign, const char *set, unsigned reverse, const char *reset,
 634                        int first, const char *line, int len)
 635{
 636        int has_trailing_newline, has_trailing_carriage_return;
 637        int needs_reset = 0; /* at the end of the line */
 638        FILE *file = o->file;
 639
 640        fputs(diff_line_prefix(o), file);
 641
 642        has_trailing_newline = (len > 0 && line[len-1] == '\n');
 643        if (has_trailing_newline)
 644                len--;
 645
 646        has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 647        if (has_trailing_carriage_return)
 648                len--;
 649
 650        if (!len && !first)
 651                goto end_of_line;
 652
 653        if (reverse && want_color(o->use_color)) {
 654                fputs(GIT_COLOR_REVERSE, file);
 655                needs_reset = 1;
 656        }
 657
 658        if (set_sign) {
 659                fputs(set_sign, file);
 660                needs_reset = 1;
 661        }
 662
 663        if (first)
 664                fputc(first, file);
 665
 666        if (!len)
 667                goto end_of_line;
 668
 669        if (set) {
 670                if (set_sign && set != set_sign)
 671                        fputs(reset, file);
 672                fputs(set, file);
 673                needs_reset = 1;
 674        }
 675        fwrite(line, len, 1, file);
 676        needs_reset = 1; /* 'line' may contain color codes. */
 677
 678end_of_line:
 679        if (needs_reset)
 680                fputs(reset, file);
 681        if (has_trailing_carriage_return)
 682                fputc('\r', file);
 683        if (has_trailing_newline)
 684                fputc('\n', file);
 685}
 686
 687static void emit_line(struct diff_options *o, const char *set, const char *reset,
 688                      const char *line, int len)
 689{
 690        emit_line_0(o, set, NULL, 0, reset, 0, line, len);
 691}
 692
 693enum diff_symbol {
 694        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 695        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 696        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 697        DIFF_SYMBOL_BINARY_DIFF_BODY,
 698        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 699        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 700        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 701        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 702        DIFF_SYMBOL_STATS_LINE,
 703        DIFF_SYMBOL_WORD_DIFF,
 704        DIFF_SYMBOL_STAT_SEP,
 705        DIFF_SYMBOL_SUMMARY,
 706        DIFF_SYMBOL_SUBMODULE_ADD,
 707        DIFF_SYMBOL_SUBMODULE_DEL,
 708        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 709        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 710        DIFF_SYMBOL_SUBMODULE_HEADER,
 711        DIFF_SYMBOL_SUBMODULE_ERROR,
 712        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 713        DIFF_SYMBOL_REWRITE_DIFF,
 714        DIFF_SYMBOL_BINARY_FILES,
 715        DIFF_SYMBOL_HEADER,
 716        DIFF_SYMBOL_FILEPAIR_PLUS,
 717        DIFF_SYMBOL_FILEPAIR_MINUS,
 718        DIFF_SYMBOL_WORDS_PORCELAIN,
 719        DIFF_SYMBOL_WORDS,
 720        DIFF_SYMBOL_CONTEXT,
 721        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 722        DIFF_SYMBOL_PLUS,
 723        DIFF_SYMBOL_MINUS,
 724        DIFF_SYMBOL_NO_LF_EOF,
 725        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 726        DIFF_SYMBOL_CONTEXT_MARKER,
 727        DIFF_SYMBOL_SEPARATOR
 728};
 729/*
 730 * Flags for content lines:
 731 * 0..12 are whitespace rules
 732 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 733 * 16 is marking if the line is blank at EOF
 734 */
 735#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 736#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 737#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 738#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 739#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 740
 741/*
 742 * This struct is used when we need to buffer the output of the diff output.
 743 *
 744 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 745 * into the pre/post image file. This pointer could be a union with the
 746 * line pointer. By storing an offset into the file instead of the literal line,
 747 * we can decrease the memory footprint for the buffered output. At first we
 748 * may want to only have indirection for the content lines, but we could also
 749 * enhance the state for emitting prefabricated lines, e.g. the similarity
 750 * score line or hunk/file headers would only need to store a number or path
 751 * and then the output can be constructed later on depending on state.
 752 */
 753struct emitted_diff_symbol {
 754        const char *line;
 755        int len;
 756        int flags;
 757        enum diff_symbol s;
 758};
 759#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 760
 761struct emitted_diff_symbols {
 762        struct emitted_diff_symbol *buf;
 763        int nr, alloc;
 764};
 765#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 766
 767static void append_emitted_diff_symbol(struct diff_options *o,
 768                                       struct emitted_diff_symbol *e)
 769{
 770        struct emitted_diff_symbol *f;
 771
 772        ALLOC_GROW(o->emitted_symbols->buf,
 773                   o->emitted_symbols->nr + 1,
 774                   o->emitted_symbols->alloc);
 775        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 776
 777        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 778        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 779}
 780
 781struct moved_entry {
 782        struct hashmap_entry ent;
 783        const struct emitted_diff_symbol *es;
 784        struct moved_entry *next_line;
 785};
 786
 787/**
 788 * The struct ws_delta holds white space differences between moved lines, i.e.
 789 * between '+' and '-' lines that have been detected to be a move.
 790 * The string contains the difference in leading white spaces, before the
 791 * rest of the line is compared using the white space config for move
 792 * coloring. The current_longer indicates if the first string in the
 793 * comparision is longer than the second.
 794 */
 795struct ws_delta {
 796        char *string;
 797        unsigned int current_longer : 1;
 798};
 799#define WS_DELTA_INIT { NULL, 0 }
 800
 801struct moved_block {
 802        struct moved_entry *match;
 803        struct ws_delta wsd;
 804};
 805
 806static void moved_block_clear(struct moved_block *b)
 807{
 808        FREE_AND_NULL(b->wsd.string);
 809        b->match = NULL;
 810}
 811
 812static int compute_ws_delta(const struct emitted_diff_symbol *a,
 813                             const struct emitted_diff_symbol *b,
 814                             struct ws_delta *out)
 815{
 816        const struct emitted_diff_symbol *longer =  a->len > b->len ? a : b;
 817        const struct emitted_diff_symbol *shorter = a->len > b->len ? b : a;
 818        int d = longer->len - shorter->len;
 819
 820        if (strncmp(longer->line + d, shorter->line, shorter->len))
 821                return 0;
 822
 823        out->string = xmemdupz(longer->line, d);
 824        out->current_longer = (a == longer);
 825
 826        return 1;
 827}
 828
 829static int cmp_in_block_with_wsd(const struct diff_options *o,
 830                                 const struct moved_entry *cur,
 831                                 const struct moved_entry *match,
 832                                 struct moved_block *pmb,
 833                                 int n)
 834{
 835        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 836        int al = cur->es->len, cl = l->len;
 837        const char *a = cur->es->line,
 838                   *b = match->es->line,
 839                   *c = l->line;
 840
 841        int wslen;
 842
 843        /*
 844         * We need to check if 'cur' is equal to 'match'.
 845         * As those are from the same (+/-) side, we do not need to adjust for
 846         * indent changes. However these were found using fuzzy matching
 847         * so we do have to check if they are equal.
 848         */
 849        if (strcmp(a, b))
 850                return 1;
 851
 852        if (!pmb->wsd.string)
 853                /*
 854                 * The white space delta is not active? This can happen
 855                 * when we exit early in this function.
 856                 */
 857                return 1;
 858
 859        /*
 860         * The indent changes of the block are known and stored in
 861         * pmb->wsd; however we need to check if the indent changes of the
 862         * current line are still the same as before.
 863         *
 864         * To do so we need to compare 'l' to 'cur', adjusting the
 865         * one of them for the white spaces, depending which was longer.
 866         */
 867
 868        wslen = strlen(pmb->wsd.string);
 869        if (pmb->wsd.current_longer) {
 870                c += wslen;
 871                cl -= wslen;
 872        } else {
 873                a += wslen;
 874                al -= wslen;
 875        }
 876
 877        if (al != cl || memcmp(a, c, al))
 878                return 1;
 879
 880        return 0;
 881}
 882
 883static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 884                           const void *entry,
 885                           const void *entry_or_key,
 886                           const void *keydata)
 887{
 888        const struct diff_options *diffopt = hashmap_cmp_fn_data;
 889        const struct moved_entry *a = entry;
 890        const struct moved_entry *b = entry_or_key;
 891        unsigned flags = diffopt->color_moved_ws_handling
 892                         & XDF_WHITESPACE_FLAGS;
 893
 894        if (diffopt->color_moved_ws_handling &
 895            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 896                /*
 897                 * As there is not specific white space config given,
 898                 * we'd need to check for a new block, so ignore all
 899                 * white space. The setup of the white space
 900                 * configuration for the next block is done else where
 901                 */
 902                flags |= XDF_IGNORE_WHITESPACE;
 903
 904        return !xdiff_compare_lines(a->es->line, a->es->len,
 905                                    b->es->line, b->es->len,
 906                                    flags);
 907}
 908
 909static struct moved_entry *prepare_entry(struct diff_options *o,
 910                                         int line_no)
 911{
 912        struct moved_entry *ret = xmalloc(sizeof(*ret));
 913        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 914        unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 915
 916        ret->ent.hash = xdiff_hash_string(l->line, l->len, flags);
 917        ret->es = l;
 918        ret->next_line = NULL;
 919
 920        return ret;
 921}
 922
 923static void add_lines_to_move_detection(struct diff_options *o,
 924                                        struct hashmap *add_lines,
 925                                        struct hashmap *del_lines)
 926{
 927        struct moved_entry *prev_line = NULL;
 928
 929        int n;
 930        for (n = 0; n < o->emitted_symbols->nr; n++) {
 931                struct hashmap *hm;
 932                struct moved_entry *key;
 933
 934                switch (o->emitted_symbols->buf[n].s) {
 935                case DIFF_SYMBOL_PLUS:
 936                        hm = add_lines;
 937                        break;
 938                case DIFF_SYMBOL_MINUS:
 939                        hm = del_lines;
 940                        break;
 941                default:
 942                        prev_line = NULL;
 943                        continue;
 944                }
 945
 946                key = prepare_entry(o, n);
 947                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 948                        prev_line->next_line = key;
 949
 950                hashmap_add(hm, key);
 951                prev_line = key;
 952        }
 953}
 954
 955static void pmb_advance_or_null(struct diff_options *o,
 956                                struct moved_entry *match,
 957                                struct hashmap *hm,
 958                                struct moved_block *pmb,
 959                                int pmb_nr)
 960{
 961        int i;
 962        for (i = 0; i < pmb_nr; i++) {
 963                struct moved_entry *prev = pmb[i].match;
 964                struct moved_entry *cur = (prev && prev->next_line) ?
 965                                prev->next_line : NULL;
 966                if (cur && !hm->cmpfn(o, cur, match, NULL)) {
 967                        pmb[i].match = cur;
 968                } else {
 969                        pmb[i].match = NULL;
 970                }
 971        }
 972}
 973
 974static void pmb_advance_or_null_multi_match(struct diff_options *o,
 975                                            struct moved_entry *match,
 976                                            struct hashmap *hm,
 977                                            struct moved_block *pmb,
 978                                            int pmb_nr, int n)
 979{
 980        int i;
 981        char *got_match = xcalloc(1, pmb_nr);
 982
 983        for (; match; match = hashmap_get_next(hm, match)) {
 984                for (i = 0; i < pmb_nr; i++) {
 985                        struct moved_entry *prev = pmb[i].match;
 986                        struct moved_entry *cur = (prev && prev->next_line) ?
 987                                        prev->next_line : NULL;
 988                        if (!cur)
 989                                continue;
 990                        if (!cmp_in_block_with_wsd(o, cur, match, &pmb[i], n))
 991                                got_match[i] |= 1;
 992                }
 993        }
 994
 995        for (i = 0; i < pmb_nr; i++) {
 996                if (got_match[i]) {
 997                        /* Advance to the next line */
 998                        pmb[i].match = pmb[i].match->next_line;
 999                } else {
1000                        moved_block_clear(&pmb[i]);
1001                }
1002        }
1003
1004        free(got_match);
1005}
1006
1007static int shrink_potential_moved_blocks(struct moved_block *pmb,
1008                                         int pmb_nr)
1009{
1010        int lp, rp;
1011
1012        /* Shrink the set of potential block to the remaining running */
1013        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
1014                while (lp < pmb_nr && pmb[lp].match)
1015                        lp++;
1016                /* lp points at the first NULL now */
1017
1018                while (rp > -1 && !pmb[rp].match)
1019                        rp--;
1020                /* rp points at the last non-NULL */
1021
1022                if (lp < pmb_nr && rp > -1 && lp < rp) {
1023                        pmb[lp] = pmb[rp];
1024                        pmb[rp].match = NULL;
1025                        pmb[rp].wsd.string = NULL;
1026                        rp--;
1027                        lp++;
1028                }
1029        }
1030
1031        /* Remember the number of running sets */
1032        return rp + 1;
1033}
1034
1035/*
1036 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
1037 *
1038 * Otherwise, if the last block has fewer alphanumeric characters than
1039 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
1040 * that block.
1041 *
1042 * The last block consists of the (n - block_length)'th line up to but not
1043 * including the nth line.
1044 *
1045 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
1046 * Think of a way to unify them.
1047 */
1048static void adjust_last_block(struct diff_options *o, int n, int block_length)
1049{
1050        int i, alnum_count = 0;
1051        if (o->color_moved == COLOR_MOVED_PLAIN)
1052                return;
1053        for (i = 1; i < block_length + 1; i++) {
1054                const char *c = o->emitted_symbols->buf[n - i].line;
1055                for (; *c; c++) {
1056                        if (!isalnum(*c))
1057                                continue;
1058                        alnum_count++;
1059                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
1060                                return;
1061                }
1062        }
1063        for (i = 1; i < block_length + 1; i++)
1064                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
1065}
1066
1067/* Find blocks of moved code, delegate actual coloring decision to helper */
1068static void mark_color_as_moved(struct diff_options *o,
1069                                struct hashmap *add_lines,
1070                                struct hashmap *del_lines)
1071{
1072        struct moved_block *pmb = NULL; /* potentially moved blocks */
1073        int pmb_nr = 0, pmb_alloc = 0;
1074        int n, flipped_block = 1, block_length = 0;
1075
1076
1077        for (n = 0; n < o->emitted_symbols->nr; n++) {
1078                struct hashmap *hm = NULL;
1079                struct moved_entry *key;
1080                struct moved_entry *match = NULL;
1081                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1082
1083                switch (l->s) {
1084                case DIFF_SYMBOL_PLUS:
1085                        hm = del_lines;
1086                        key = prepare_entry(o, n);
1087                        match = hashmap_get(hm, key, NULL);
1088                        free(key);
1089                        break;
1090                case DIFF_SYMBOL_MINUS:
1091                        hm = add_lines;
1092                        key = prepare_entry(o, n);
1093                        match = hashmap_get(hm, key, NULL);
1094                        free(key);
1095                        break;
1096                default:
1097                        flipped_block = 1;
1098                }
1099
1100                if (!match) {
1101                        int i;
1102
1103                        adjust_last_block(o, n, block_length);
1104                        for(i = 0; i < pmb_nr; i++)
1105                                moved_block_clear(&pmb[i]);
1106                        pmb_nr = 0;
1107                        block_length = 0;
1108                        continue;
1109                }
1110
1111                l->flags |= DIFF_SYMBOL_MOVED_LINE;
1112
1113                if (o->color_moved == COLOR_MOVED_PLAIN)
1114                        continue;
1115
1116                if (o->color_moved_ws_handling &
1117                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1118                        pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
1119                else
1120                        pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
1121
1122                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
1123
1124                if (pmb_nr == 0) {
1125                        /*
1126                         * The current line is the start of a new block.
1127                         * Setup the set of potential blocks.
1128                         */
1129                        for (; match; match = hashmap_get_next(hm, match)) {
1130                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
1131                                if (o->color_moved_ws_handling &
1132                                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
1133                                        if (compute_ws_delta(l, match->es,
1134                                                             &pmb[pmb_nr].wsd))
1135                                                pmb[pmb_nr++].match = match;
1136                                } else {
1137                                        pmb[pmb_nr].wsd.string = NULL;
1138                                        pmb[pmb_nr++].match = match;
1139                                }
1140                        }
1141
1142                        flipped_block = (flipped_block + 1) % 2;
1143
1144                        adjust_last_block(o, n, block_length);
1145                        block_length = 0;
1146                }
1147
1148                block_length++;
1149
1150                if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
1151                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
1152        }
1153        adjust_last_block(o, n, block_length);
1154
1155        for(n = 0; n < pmb_nr; n++)
1156                moved_block_clear(&pmb[n]);
1157        free(pmb);
1158}
1159
1160#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
1161  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
1162static void dim_moved_lines(struct diff_options *o)
1163{
1164        int n;
1165        for (n = 0; n < o->emitted_symbols->nr; n++) {
1166                struct emitted_diff_symbol *prev = (n != 0) ?
1167                                &o->emitted_symbols->buf[n - 1] : NULL;
1168                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1169                struct emitted_diff_symbol *next =
1170                                (n < o->emitted_symbols->nr - 1) ?
1171                                &o->emitted_symbols->buf[n + 1] : NULL;
1172
1173                /* Not a plus or minus line? */
1174                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
1175                        continue;
1176
1177                /* Not a moved line? */
1178                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
1179                        continue;
1180
1181                /*
1182                 * If prev or next are not a plus or minus line,
1183                 * pretend they don't exist
1184                 */
1185                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1186                            prev->s != DIFF_SYMBOL_MINUS)
1187                        prev = NULL;
1188                if (next && next->s != DIFF_SYMBOL_PLUS &&
1189                            next->s != DIFF_SYMBOL_MINUS)
1190                        next = NULL;
1191
1192                /* Inside a block? */
1193                if ((prev &&
1194                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1195                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1196                    (next &&
1197                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1198                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1199                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1200                        continue;
1201                }
1202
1203                /* Check if we are at an interesting bound: */
1204                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1205                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1206                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1207                        continue;
1208                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1209                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1210                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1211                        continue;
1212
1213                /*
1214                 * The boundary to prev and next are not interesting,
1215                 * so this line is not interesting as a whole
1216                 */
1217                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1218        }
1219}
1220
1221static void emit_line_ws_markup(struct diff_options *o,
1222                                const char *set_sign, const char *set,
1223                                const char *reset,
1224                                int sign_index, const char *line, int len,
1225                                unsigned ws_rule, int blank_at_eof)
1226{
1227        const char *ws = NULL;
1228        int sign = o->output_indicators[sign_index];
1229
1230        if (o->ws_error_highlight & ws_rule) {
1231                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1232                if (!*ws)
1233                        ws = NULL;
1234        }
1235
1236        if (!ws && !set_sign)
1237                emit_line_0(o, set, NULL, 0, reset, sign, line, len);
1238        else if (!ws) {
1239                emit_line_0(o, set_sign, set, !!set_sign, reset, sign, line, len);
1240        } else if (blank_at_eof)
1241                /* Blank line at EOF - paint '+' as well */
1242                emit_line_0(o, ws, NULL, 0, reset, sign, line, len);
1243        else {
1244                /* Emit just the prefix, then the rest. */
1245                emit_line_0(o, set_sign ? set_sign : set, NULL, !!set_sign, reset,
1246                            sign, "", 0);
1247                ws_check_emit(line, len, ws_rule,
1248                              o->file, set, reset, ws);
1249        }
1250}
1251
1252static void emit_diff_symbol_from_struct(struct diff_options *o,
1253                                         struct emitted_diff_symbol *eds)
1254{
1255        static const char *nneof = " No newline at end of file\n";
1256        const char *context, *reset, *set, *set_sign, *meta, *fraginfo;
1257        struct strbuf sb = STRBUF_INIT;
1258
1259        enum diff_symbol s = eds->s;
1260        const char *line = eds->line;
1261        int len = eds->len;
1262        unsigned flags = eds->flags;
1263
1264        switch (s) {
1265        case DIFF_SYMBOL_NO_LF_EOF:
1266                context = diff_get_color_opt(o, DIFF_CONTEXT);
1267                reset = diff_get_color_opt(o, DIFF_RESET);
1268                putc('\n', o->file);
1269                emit_line_0(o, context, NULL, 0, reset, '\\',
1270                            nneof, strlen(nneof));
1271                break;
1272        case DIFF_SYMBOL_SUBMODULE_HEADER:
1273        case DIFF_SYMBOL_SUBMODULE_ERROR:
1274        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1275        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1276        case DIFF_SYMBOL_SUMMARY:
1277        case DIFF_SYMBOL_STATS_LINE:
1278        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1279        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1280                emit_line(o, "", "", line, len);
1281                break;
1282        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1283        case DIFF_SYMBOL_CONTEXT_MARKER:
1284                context = diff_get_color_opt(o, DIFF_CONTEXT);
1285                reset = diff_get_color_opt(o, DIFF_RESET);
1286                emit_line(o, context, reset, line, len);
1287                break;
1288        case DIFF_SYMBOL_SEPARATOR:
1289                fprintf(o->file, "%s%c",
1290                        diff_line_prefix(o),
1291                        o->line_termination);
1292                break;
1293        case DIFF_SYMBOL_CONTEXT:
1294                set = diff_get_color_opt(o, DIFF_CONTEXT);
1295                reset = diff_get_color_opt(o, DIFF_RESET);
1296                set_sign = NULL;
1297                if (o->flags.dual_color_diffed_diffs) {
1298                        char c = !len ? 0 : line[0];
1299
1300                        if (c == '+')
1301                                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1302                        else if (c == '@')
1303                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1304                        else if (c == '-')
1305                                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1306                }
1307                emit_line_ws_markup(o, set_sign, set, reset,
1308                                    OUTPUT_INDICATOR_CONTEXT, line, len,
1309                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1310                break;
1311        case DIFF_SYMBOL_PLUS:
1312                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1313                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1314                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1315                case DIFF_SYMBOL_MOVED_LINE |
1316                     DIFF_SYMBOL_MOVED_LINE_ALT |
1317                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1318                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1319                        break;
1320                case DIFF_SYMBOL_MOVED_LINE |
1321                     DIFF_SYMBOL_MOVED_LINE_ALT:
1322                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1323                        break;
1324                case DIFF_SYMBOL_MOVED_LINE |
1325                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1326                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1327                        break;
1328                case DIFF_SYMBOL_MOVED_LINE:
1329                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1330                        break;
1331                default:
1332                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1333                }
1334                reset = diff_get_color_opt(o, DIFF_RESET);
1335                if (!o->flags.dual_color_diffed_diffs)
1336                        set_sign = NULL;
1337                else {
1338                        char c = !len ? 0 : line[0];
1339
1340                        set_sign = set;
1341                        if (c == '-')
1342                                set = diff_get_color_opt(o, DIFF_FILE_OLD_BOLD);
1343                        else if (c == '@')
1344                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1345                        else if (c == '+')
1346                                set = diff_get_color_opt(o, DIFF_FILE_NEW_BOLD);
1347                        else
1348                                set = diff_get_color_opt(o, DIFF_CONTEXT_BOLD);
1349                        flags &= ~DIFF_SYMBOL_CONTENT_WS_MASK;
1350                }
1351                emit_line_ws_markup(o, set_sign, set, reset,
1352                                    OUTPUT_INDICATOR_NEW, line, len,
1353                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1354                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1355                break;
1356        case DIFF_SYMBOL_MINUS:
1357                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1358                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1359                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1360                case DIFF_SYMBOL_MOVED_LINE |
1361                     DIFF_SYMBOL_MOVED_LINE_ALT |
1362                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1363                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1364                        break;
1365                case DIFF_SYMBOL_MOVED_LINE |
1366                     DIFF_SYMBOL_MOVED_LINE_ALT:
1367                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1368                        break;
1369                case DIFF_SYMBOL_MOVED_LINE |
1370                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1371                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1372                        break;
1373                case DIFF_SYMBOL_MOVED_LINE:
1374                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1375                        break;
1376                default:
1377                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1378                }
1379                reset = diff_get_color_opt(o, DIFF_RESET);
1380                if (!o->flags.dual_color_diffed_diffs)
1381                        set_sign = NULL;
1382                else {
1383                        char c = !len ? 0 : line[0];
1384
1385                        set_sign = set;
1386                        if (c == '+')
1387                                set = diff_get_color_opt(o, DIFF_FILE_NEW_DIM);
1388                        else if (c == '@')
1389                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1390                        else if (c == '-')
1391                                set = diff_get_color_opt(o, DIFF_FILE_OLD_DIM);
1392                        else
1393                                set = diff_get_color_opt(o, DIFF_CONTEXT_DIM);
1394                }
1395                emit_line_ws_markup(o, set_sign, set, reset,
1396                                    OUTPUT_INDICATOR_OLD, line, len,
1397                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1398                break;
1399        case DIFF_SYMBOL_WORDS_PORCELAIN:
1400                context = diff_get_color_opt(o, DIFF_CONTEXT);
1401                reset = diff_get_color_opt(o, DIFF_RESET);
1402                emit_line(o, context, reset, line, len);
1403                fputs("~\n", o->file);
1404                break;
1405        case DIFF_SYMBOL_WORDS:
1406                context = diff_get_color_opt(o, DIFF_CONTEXT);
1407                reset = diff_get_color_opt(o, DIFF_RESET);
1408                /*
1409                 * Skip the prefix character, if any.  With
1410                 * diff_suppress_blank_empty, there may be
1411                 * none.
1412                 */
1413                if (line[0] != '\n') {
1414                        line++;
1415                        len--;
1416                }
1417                emit_line(o, context, reset, line, len);
1418                break;
1419        case DIFF_SYMBOL_FILEPAIR_PLUS:
1420                meta = diff_get_color_opt(o, DIFF_METAINFO);
1421                reset = diff_get_color_opt(o, DIFF_RESET);
1422                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1423                        line, reset,
1424                        strchr(line, ' ') ? "\t" : "");
1425                break;
1426        case DIFF_SYMBOL_FILEPAIR_MINUS:
1427                meta = diff_get_color_opt(o, DIFF_METAINFO);
1428                reset = diff_get_color_opt(o, DIFF_RESET);
1429                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1430                        line, reset,
1431                        strchr(line, ' ') ? "\t" : "");
1432                break;
1433        case DIFF_SYMBOL_BINARY_FILES:
1434        case DIFF_SYMBOL_HEADER:
1435                fprintf(o->file, "%s", line);
1436                break;
1437        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1438                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1439                break;
1440        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1441                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1442                break;
1443        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1444                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1445                break;
1446        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1447                fputs(diff_line_prefix(o), o->file);
1448                fputc('\n', o->file);
1449                break;
1450        case DIFF_SYMBOL_REWRITE_DIFF:
1451                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1452                reset = diff_get_color_opt(o, DIFF_RESET);
1453                emit_line(o, fraginfo, reset, line, len);
1454                break;
1455        case DIFF_SYMBOL_SUBMODULE_ADD:
1456                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1457                reset = diff_get_color_opt(o, DIFF_RESET);
1458                emit_line(o, set, reset, line, len);
1459                break;
1460        case DIFF_SYMBOL_SUBMODULE_DEL:
1461                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1462                reset = diff_get_color_opt(o, DIFF_RESET);
1463                emit_line(o, set, reset, line, len);
1464                break;
1465        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1466                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1467                        diff_line_prefix(o), line);
1468                break;
1469        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1470                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1471                        diff_line_prefix(o), line);
1472                break;
1473        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1474                emit_line(o, "", "", " 0 files changed\n",
1475                          strlen(" 0 files changed\n"));
1476                break;
1477        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1478                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1479                break;
1480        case DIFF_SYMBOL_WORD_DIFF:
1481                fprintf(o->file, "%.*s", len, line);
1482                break;
1483        case DIFF_SYMBOL_STAT_SEP:
1484                fputs(o->stat_sep, o->file);
1485                break;
1486        default:
1487                BUG("unknown diff symbol");
1488        }
1489        strbuf_release(&sb);
1490}
1491
1492static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1493                             const char *line, int len, unsigned flags)
1494{
1495        struct emitted_diff_symbol e = {line, len, flags, s};
1496
1497        if (o->emitted_symbols)
1498                append_emitted_diff_symbol(o, &e);
1499        else
1500                emit_diff_symbol_from_struct(o, &e);
1501}
1502
1503void diff_emit_submodule_del(struct diff_options *o, const char *line)
1504{
1505        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1506}
1507
1508void diff_emit_submodule_add(struct diff_options *o, const char *line)
1509{
1510        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1511}
1512
1513void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1514{
1515        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1516                         path, strlen(path), 0);
1517}
1518
1519void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1520{
1521        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1522                         path, strlen(path), 0);
1523}
1524
1525void diff_emit_submodule_header(struct diff_options *o, const char *header)
1526{
1527        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1528                         header, strlen(header), 0);
1529}
1530
1531void diff_emit_submodule_error(struct diff_options *o, const char *err)
1532{
1533        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1534}
1535
1536void diff_emit_submodule_pipethrough(struct diff_options *o,
1537                                     const char *line, int len)
1538{
1539        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1540}
1541
1542static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1543{
1544        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1545              ecbdata->blank_at_eof_in_preimage &&
1546              ecbdata->blank_at_eof_in_postimage &&
1547              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1548              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1549                return 0;
1550        return ws_blank_line(line, len, ecbdata->ws_rule);
1551}
1552
1553static void emit_add_line(const char *reset,
1554                          struct emit_callback *ecbdata,
1555                          const char *line, int len)
1556{
1557        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1558        if (new_blank_line_at_eof(ecbdata, line, len))
1559                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1560
1561        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1562}
1563
1564static void emit_del_line(const char *reset,
1565                          struct emit_callback *ecbdata,
1566                          const char *line, int len)
1567{
1568        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1569        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1570}
1571
1572static void emit_context_line(const char *reset,
1573                              struct emit_callback *ecbdata,
1574                              const char *line, int len)
1575{
1576        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1577        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1578}
1579
1580static void emit_hunk_header(struct emit_callback *ecbdata,
1581                             const char *line, int len)
1582{
1583        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1584        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1585        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1586        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1587        const char *reverse = ecbdata->color_diff ? GIT_COLOR_REVERSE : "";
1588        static const char atat[2] = { '@', '@' };
1589        const char *cp, *ep;
1590        struct strbuf msgbuf = STRBUF_INIT;
1591        int org_len = len;
1592        int i = 1;
1593
1594        /*
1595         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1596         * it always is at least 10 bytes long.
1597         */
1598        if (len < 10 ||
1599            memcmp(line, atat, 2) ||
1600            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1601                emit_diff_symbol(ecbdata->opt,
1602                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1603                return;
1604        }
1605        ep += 2; /* skip over @@ */
1606
1607        /* The hunk header in fraginfo color */
1608        if (ecbdata->opt->flags.dual_color_diffed_diffs)
1609                strbuf_addstr(&msgbuf, reverse);
1610        strbuf_addstr(&msgbuf, frag);
1611        strbuf_add(&msgbuf, line, ep - line);
1612        strbuf_addstr(&msgbuf, reset);
1613
1614        /*
1615         * trailing "\r\n"
1616         */
1617        for ( ; i < 3; i++)
1618                if (line[len - i] == '\r' || line[len - i] == '\n')
1619                        len--;
1620
1621        /* blank before the func header */
1622        for (cp = ep; ep - line < len; ep++)
1623                if (*ep != ' ' && *ep != '\t')
1624                        break;
1625        if (ep != cp) {
1626                strbuf_addstr(&msgbuf, context);
1627                strbuf_add(&msgbuf, cp, ep - cp);
1628                strbuf_addstr(&msgbuf, reset);
1629        }
1630
1631        if (ep < line + len) {
1632                strbuf_addstr(&msgbuf, func);
1633                strbuf_add(&msgbuf, ep, line + len - ep);
1634                strbuf_addstr(&msgbuf, reset);
1635        }
1636
1637        strbuf_add(&msgbuf, line + len, org_len - len);
1638        strbuf_complete_line(&msgbuf);
1639        emit_diff_symbol(ecbdata->opt,
1640                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1641        strbuf_release(&msgbuf);
1642}
1643
1644static struct diff_tempfile *claim_diff_tempfile(void)
1645{
1646        int i;
1647        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1648                if (!diff_temp[i].name)
1649                        return diff_temp + i;
1650        BUG("diff is failing to clean up its tempfiles");
1651}
1652
1653static void remove_tempfile(void)
1654{
1655        int i;
1656        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1657                if (is_tempfile_active(diff_temp[i].tempfile))
1658                        delete_tempfile(&diff_temp[i].tempfile);
1659                diff_temp[i].name = NULL;
1660        }
1661}
1662
1663static void add_line_count(struct strbuf *out, int count)
1664{
1665        switch (count) {
1666        case 0:
1667                strbuf_addstr(out, "0,0");
1668                break;
1669        case 1:
1670                strbuf_addstr(out, "1");
1671                break;
1672        default:
1673                strbuf_addf(out, "1,%d", count);
1674                break;
1675        }
1676}
1677
1678static void emit_rewrite_lines(struct emit_callback *ecb,
1679                               int prefix, const char *data, int size)
1680{
1681        const char *endp = NULL;
1682        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1683
1684        while (0 < size) {
1685                int len;
1686
1687                endp = memchr(data, '\n', size);
1688                len = endp ? (endp - data + 1) : size;
1689                if (prefix != '+') {
1690                        ecb->lno_in_preimage++;
1691                        emit_del_line(reset, ecb, data, len);
1692                } else {
1693                        ecb->lno_in_postimage++;
1694                        emit_add_line(reset, ecb, data, len);
1695                }
1696                size -= len;
1697                data += len;
1698        }
1699        if (!endp)
1700                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1701}
1702
1703static void emit_rewrite_diff(const char *name_a,
1704                              const char *name_b,
1705                              struct diff_filespec *one,
1706                              struct diff_filespec *two,
1707                              struct userdiff_driver *textconv_one,
1708                              struct userdiff_driver *textconv_two,
1709                              struct diff_options *o)
1710{
1711        int lc_a, lc_b;
1712        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1713        const char *a_prefix, *b_prefix;
1714        char *data_one, *data_two;
1715        size_t size_one, size_two;
1716        struct emit_callback ecbdata;
1717        struct strbuf out = STRBUF_INIT;
1718
1719        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1720                a_prefix = o->b_prefix;
1721                b_prefix = o->a_prefix;
1722        } else {
1723                a_prefix = o->a_prefix;
1724                b_prefix = o->b_prefix;
1725        }
1726
1727        name_a += (*name_a == '/');
1728        name_b += (*name_b == '/');
1729
1730        strbuf_reset(&a_name);
1731        strbuf_reset(&b_name);
1732        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1733        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1734
1735        size_one = fill_textconv(o->repo, textconv_one, one, &data_one);
1736        size_two = fill_textconv(o->repo, textconv_two, two, &data_two);
1737
1738        memset(&ecbdata, 0, sizeof(ecbdata));
1739        ecbdata.color_diff = want_color(o->use_color);
1740        ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
1741        ecbdata.opt = o;
1742        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1743                mmfile_t mf1, mf2;
1744                mf1.ptr = (char *)data_one;
1745                mf2.ptr = (char *)data_two;
1746                mf1.size = size_one;
1747                mf2.size = size_two;
1748                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1749        }
1750        ecbdata.lno_in_preimage = 1;
1751        ecbdata.lno_in_postimage = 1;
1752
1753        lc_a = count_lines(data_one, size_one);
1754        lc_b = count_lines(data_two, size_two);
1755
1756        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1757                         a_name.buf, a_name.len, 0);
1758        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1759                         b_name.buf, b_name.len, 0);
1760
1761        strbuf_addstr(&out, "@@ -");
1762        if (!o->irreversible_delete)
1763                add_line_count(&out, lc_a);
1764        else
1765                strbuf_addstr(&out, "?,?");
1766        strbuf_addstr(&out, " +");
1767        add_line_count(&out, lc_b);
1768        strbuf_addstr(&out, " @@\n");
1769        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1770        strbuf_release(&out);
1771
1772        if (lc_a && !o->irreversible_delete)
1773                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1774        if (lc_b)
1775                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1776        if (textconv_one)
1777                free((char *)data_one);
1778        if (textconv_two)
1779                free((char *)data_two);
1780}
1781
1782struct diff_words_buffer {
1783        mmfile_t text;
1784        unsigned long alloc;
1785        struct diff_words_orig {
1786                const char *begin, *end;
1787        } *orig;
1788        int orig_nr, orig_alloc;
1789};
1790
1791static void diff_words_append(char *line, unsigned long len,
1792                struct diff_words_buffer *buffer)
1793{
1794        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1795        line++;
1796        len--;
1797        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1798        buffer->text.size += len;
1799        buffer->text.ptr[buffer->text.size] = '\0';
1800}
1801
1802struct diff_words_style_elem {
1803        const char *prefix;
1804        const char *suffix;
1805        const char *color; /* NULL; filled in by the setup code if
1806                            * color is enabled */
1807};
1808
1809struct diff_words_style {
1810        enum diff_words_type type;
1811        struct diff_words_style_elem new_word, old_word, ctx;
1812        const char *newline;
1813};
1814
1815static struct diff_words_style diff_words_styles[] = {
1816        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1817        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1818        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1819};
1820
1821struct diff_words_data {
1822        struct diff_words_buffer minus, plus;
1823        const char *current_plus;
1824        int last_minus;
1825        struct diff_options *opt;
1826        regex_t *word_regex;
1827        enum diff_words_type type;
1828        struct diff_words_style *style;
1829};
1830
1831static int fn_out_diff_words_write_helper(struct diff_options *o,
1832                                          struct diff_words_style_elem *st_el,
1833                                          const char *newline,
1834                                          size_t count, const char *buf)
1835{
1836        int print = 0;
1837        struct strbuf sb = STRBUF_INIT;
1838
1839        while (count) {
1840                char *p = memchr(buf, '\n', count);
1841                if (print)
1842                        strbuf_addstr(&sb, diff_line_prefix(o));
1843
1844                if (p != buf) {
1845                        const char *reset = st_el->color && *st_el->color ?
1846                                            GIT_COLOR_RESET : NULL;
1847                        if (st_el->color && *st_el->color)
1848                                strbuf_addstr(&sb, st_el->color);
1849                        strbuf_addstr(&sb, st_el->prefix);
1850                        strbuf_add(&sb, buf, p ? p - buf : count);
1851                        strbuf_addstr(&sb, st_el->suffix);
1852                        if (reset)
1853                                strbuf_addstr(&sb, reset);
1854                }
1855                if (!p)
1856                        goto out;
1857
1858                strbuf_addstr(&sb, newline);
1859                count -= p + 1 - buf;
1860                buf = p + 1;
1861                print = 1;
1862                if (count) {
1863                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1864                                         sb.buf, sb.len, 0);
1865                        strbuf_reset(&sb);
1866                }
1867        }
1868
1869out:
1870        if (sb.len)
1871                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1872                                 sb.buf, sb.len, 0);
1873        strbuf_release(&sb);
1874        return 0;
1875}
1876
1877/*
1878 * '--color-words' algorithm can be described as:
1879 *
1880 *   1. collect the minus/plus lines of a diff hunk, divided into
1881 *      minus-lines and plus-lines;
1882 *
1883 *   2. break both minus-lines and plus-lines into words and
1884 *      place them into two mmfile_t with one word for each line;
1885 *
1886 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1887 *
1888 * And for the common parts of the both file, we output the plus side text.
1889 * diff_words->current_plus is used to trace the current position of the plus file
1890 * which printed. diff_words->last_minus is used to trace the last minus word
1891 * printed.
1892 *
1893 * For '--graph' to work with '--color-words', we need to output the graph prefix
1894 * on each line of color words output. Generally, there are two conditions on
1895 * which we should output the prefix.
1896 *
1897 *   1. diff_words->last_minus == 0 &&
1898 *      diff_words->current_plus == diff_words->plus.text.ptr
1899 *
1900 *      that is: the plus text must start as a new line, and if there is no minus
1901 *      word printed, a graph prefix must be printed.
1902 *
1903 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1904 *      *(diff_words->current_plus - 1) == '\n'
1905 *
1906 *      that is: a graph prefix must be printed following a '\n'
1907 */
1908static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1909{
1910        if ((diff_words->last_minus == 0 &&
1911                diff_words->current_plus == diff_words->plus.text.ptr) ||
1912                (diff_words->current_plus > diff_words->plus.text.ptr &&
1913                *(diff_words->current_plus - 1) == '\n')) {
1914                return 1;
1915        } else {
1916                return 0;
1917        }
1918}
1919
1920static void fn_out_diff_words_aux(void *priv,
1921                                  long minus_first, long minus_len,
1922                                  long plus_first, long plus_len,
1923                                  const char *func, long funclen)
1924{
1925        struct diff_words_data *diff_words = priv;
1926        struct diff_words_style *style = diff_words->style;
1927        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1928        struct diff_options *opt = diff_words->opt;
1929        const char *line_prefix;
1930
1931        assert(opt);
1932        line_prefix = diff_line_prefix(opt);
1933
1934        /* POSIX requires that first be decremented by one if len == 0... */
1935        if (minus_len) {
1936                minus_begin = diff_words->minus.orig[minus_first].begin;
1937                minus_end =
1938                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1939        } else
1940                minus_begin = minus_end =
1941                        diff_words->minus.orig[minus_first].end;
1942
1943        if (plus_len) {
1944                plus_begin = diff_words->plus.orig[plus_first].begin;
1945                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1946        } else
1947                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1948
1949        if (color_words_output_graph_prefix(diff_words)) {
1950                fputs(line_prefix, diff_words->opt->file);
1951        }
1952        if (diff_words->current_plus != plus_begin) {
1953                fn_out_diff_words_write_helper(diff_words->opt,
1954                                &style->ctx, style->newline,
1955                                plus_begin - diff_words->current_plus,
1956                                diff_words->current_plus);
1957        }
1958        if (minus_begin != minus_end) {
1959                fn_out_diff_words_write_helper(diff_words->opt,
1960                                &style->old_word, style->newline,
1961                                minus_end - minus_begin, minus_begin);
1962        }
1963        if (plus_begin != plus_end) {
1964                fn_out_diff_words_write_helper(diff_words->opt,
1965                                &style->new_word, style->newline,
1966                                plus_end - plus_begin, plus_begin);
1967        }
1968
1969        diff_words->current_plus = plus_end;
1970        diff_words->last_minus = minus_first;
1971}
1972
1973/* This function starts looking at *begin, and returns 0 iff a word was found. */
1974static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1975                int *begin, int *end)
1976{
1977        if (word_regex && *begin < buffer->size) {
1978                regmatch_t match[1];
1979                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1980                                 buffer->size - *begin, 1, match, 0)) {
1981                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1982                                        '\n', match[0].rm_eo - match[0].rm_so);
1983                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1984                        *begin += match[0].rm_so;
1985                        return *begin >= *end;
1986                }
1987                return -1;
1988        }
1989
1990        /* find the next word */
1991        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1992                (*begin)++;
1993        if (*begin >= buffer->size)
1994                return -1;
1995
1996        /* find the end of the word */
1997        *end = *begin + 1;
1998        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1999                (*end)++;
2000
2001        return 0;
2002}
2003
2004/*
2005 * This function splits the words in buffer->text, stores the list with
2006 * newline separator into out, and saves the offsets of the original words
2007 * in buffer->orig.
2008 */
2009static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
2010                regex_t *word_regex)
2011{
2012        int i, j;
2013        long alloc = 0;
2014
2015        out->size = 0;
2016        out->ptr = NULL;
2017
2018        /* fake an empty "0th" word */
2019        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
2020        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
2021        buffer->orig_nr = 1;
2022
2023        for (i = 0; i < buffer->text.size; i++) {
2024                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
2025                        return;
2026
2027                /* store original boundaries */
2028                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
2029                                buffer->orig_alloc);
2030                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
2031                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
2032                buffer->orig_nr++;
2033
2034                /* store one word */
2035                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
2036                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
2037                out->ptr[out->size + j - i] = '\n';
2038                out->size += j - i + 1;
2039
2040                i = j - 1;
2041        }
2042}
2043
2044/* this executes the word diff on the accumulated buffers */
2045static void diff_words_show(struct diff_words_data *diff_words)
2046{
2047        xpparam_t xpp;
2048        xdemitconf_t xecfg;
2049        mmfile_t minus, plus;
2050        struct diff_words_style *style = diff_words->style;
2051
2052        struct diff_options *opt = diff_words->opt;
2053        const char *line_prefix;
2054
2055        assert(opt);
2056        line_prefix = diff_line_prefix(opt);
2057
2058        /* special case: only removal */
2059        if (!diff_words->plus.text.size) {
2060                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2061                                 line_prefix, strlen(line_prefix), 0);
2062                fn_out_diff_words_write_helper(diff_words->opt,
2063                        &style->old_word, style->newline,
2064                        diff_words->minus.text.size,
2065                        diff_words->minus.text.ptr);
2066                diff_words->minus.text.size = 0;
2067                return;
2068        }
2069
2070        diff_words->current_plus = diff_words->plus.text.ptr;
2071        diff_words->last_minus = 0;
2072
2073        memset(&xpp, 0, sizeof(xpp));
2074        memset(&xecfg, 0, sizeof(xecfg));
2075        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
2076        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
2077        xpp.flags = 0;
2078        /* as only the hunk header will be parsed, we need a 0-context */
2079        xecfg.ctxlen = 0;
2080        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, NULL,
2081                          diff_words, &xpp, &xecfg))
2082                die("unable to generate word diff");
2083        free(minus.ptr);
2084        free(plus.ptr);
2085        if (diff_words->current_plus != diff_words->plus.text.ptr +
2086                        diff_words->plus.text.size) {
2087                if (color_words_output_graph_prefix(diff_words))
2088                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2089                                         line_prefix, strlen(line_prefix), 0);
2090                fn_out_diff_words_write_helper(diff_words->opt,
2091                        &style->ctx, style->newline,
2092                        diff_words->plus.text.ptr + diff_words->plus.text.size
2093                        - diff_words->current_plus, diff_words->current_plus);
2094        }
2095        diff_words->minus.text.size = diff_words->plus.text.size = 0;
2096}
2097
2098/* In "color-words" mode, show word-diff of words accumulated in the buffer */
2099static void diff_words_flush(struct emit_callback *ecbdata)
2100{
2101        struct diff_options *wo = ecbdata->diff_words->opt;
2102
2103        if (ecbdata->diff_words->minus.text.size ||
2104            ecbdata->diff_words->plus.text.size)
2105                diff_words_show(ecbdata->diff_words);
2106
2107        if (wo->emitted_symbols) {
2108                struct diff_options *o = ecbdata->opt;
2109                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2110                int i;
2111
2112                /*
2113                 * NEEDSWORK:
2114                 * Instead of appending each, concat all words to a line?
2115                 */
2116                for (i = 0; i < wol->nr; i++)
2117                        append_emitted_diff_symbol(o, &wol->buf[i]);
2118
2119                for (i = 0; i < wol->nr; i++)
2120                        free((void *)wol->buf[i].line);
2121
2122                wol->nr = 0;
2123        }
2124}
2125
2126static void diff_filespec_load_driver(struct diff_filespec *one,
2127                                      struct index_state *istate)
2128{
2129        /* Use already-loaded driver */
2130        if (one->driver)
2131                return;
2132
2133        if (S_ISREG(one->mode))
2134                one->driver = userdiff_find_by_path(istate, one->path);
2135
2136        /* Fallback to default settings */
2137        if (!one->driver)
2138                one->driver = userdiff_find_by_name("default");
2139}
2140
2141static const char *userdiff_word_regex(struct diff_filespec *one,
2142                                       struct index_state *istate)
2143{
2144        diff_filespec_load_driver(one, istate);
2145        return one->driver->word_regex;
2146}
2147
2148static void init_diff_words_data(struct emit_callback *ecbdata,
2149                                 struct diff_options *orig_opts,
2150                                 struct diff_filespec *one,
2151                                 struct diff_filespec *two)
2152{
2153        int i;
2154        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2155        memcpy(o, orig_opts, sizeof(struct diff_options));
2156
2157        ecbdata->diff_words =
2158                xcalloc(1, sizeof(struct diff_words_data));
2159        ecbdata->diff_words->type = o->word_diff;
2160        ecbdata->diff_words->opt = o;
2161
2162        if (orig_opts->emitted_symbols)
2163                o->emitted_symbols =
2164                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2165
2166        if (!o->word_regex)
2167                o->word_regex = userdiff_word_regex(one, o->repo->index);
2168        if (!o->word_regex)
2169                o->word_regex = userdiff_word_regex(two, o->repo->index);
2170        if (!o->word_regex)
2171                o->word_regex = diff_word_regex_cfg;
2172        if (o->word_regex) {
2173                ecbdata->diff_words->word_regex = (regex_t *)
2174                        xmalloc(sizeof(regex_t));
2175                if (regcomp(ecbdata->diff_words->word_regex,
2176                            o->word_regex,
2177                            REG_EXTENDED | REG_NEWLINE))
2178                        die("invalid regular expression: %s",
2179                            o->word_regex);
2180        }
2181        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2182                if (o->word_diff == diff_words_styles[i].type) {
2183                        ecbdata->diff_words->style =
2184                                &diff_words_styles[i];
2185                        break;
2186                }
2187        }
2188        if (want_color(o->use_color)) {
2189                struct diff_words_style *st = ecbdata->diff_words->style;
2190                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2191                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2192                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2193        }
2194}
2195
2196static void free_diff_words_data(struct emit_callback *ecbdata)
2197{
2198        if (ecbdata->diff_words) {
2199                diff_words_flush(ecbdata);
2200                free (ecbdata->diff_words->opt->emitted_symbols);
2201                free (ecbdata->diff_words->opt);
2202                free (ecbdata->diff_words->minus.text.ptr);
2203                free (ecbdata->diff_words->minus.orig);
2204                free (ecbdata->diff_words->plus.text.ptr);
2205                free (ecbdata->diff_words->plus.orig);
2206                if (ecbdata->diff_words->word_regex) {
2207                        regfree(ecbdata->diff_words->word_regex);
2208                        free(ecbdata->diff_words->word_regex);
2209                }
2210                FREE_AND_NULL(ecbdata->diff_words);
2211        }
2212}
2213
2214const char *diff_get_color(int diff_use_color, enum color_diff ix)
2215{
2216        if (want_color(diff_use_color))
2217                return diff_colors[ix];
2218        return "";
2219}
2220
2221const char *diff_line_prefix(struct diff_options *opt)
2222{
2223        struct strbuf *msgbuf;
2224        if (!opt->output_prefix)
2225                return "";
2226
2227        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2228        return msgbuf->buf;
2229}
2230
2231static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
2232{
2233        const char *cp;
2234        unsigned long allot;
2235        size_t l = len;
2236
2237        cp = line;
2238        allot = l;
2239        while (0 < l) {
2240                (void) utf8_width(&cp, &l);
2241                if (!cp)
2242                        break; /* truncated in the middle? */
2243        }
2244        return allot - l;
2245}
2246
2247static void find_lno(const char *line, struct emit_callback *ecbdata)
2248{
2249        const char *p;
2250        ecbdata->lno_in_preimage = 0;
2251        ecbdata->lno_in_postimage = 0;
2252        p = strchr(line, '-');
2253        if (!p)
2254                return; /* cannot happen */
2255        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2256        p = strchr(p, '+');
2257        if (!p)
2258                return; /* cannot happen */
2259        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2260}
2261
2262static void fn_out_consume(void *priv, char *line, unsigned long len)
2263{
2264        struct emit_callback *ecbdata = priv;
2265        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2266        struct diff_options *o = ecbdata->opt;
2267
2268        o->found_changes = 1;
2269
2270        if (ecbdata->header) {
2271                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2272                                 ecbdata->header->buf, ecbdata->header->len, 0);
2273                strbuf_reset(ecbdata->header);
2274                ecbdata->header = NULL;
2275        }
2276
2277        if (ecbdata->label_path[0]) {
2278                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2279                                 ecbdata->label_path[0],
2280                                 strlen(ecbdata->label_path[0]), 0);
2281                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2282                                 ecbdata->label_path[1],
2283                                 strlen(ecbdata->label_path[1]), 0);
2284                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2285        }
2286
2287        if (diff_suppress_blank_empty
2288            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2289                line[0] = '\n';
2290                len = 1;
2291        }
2292
2293        if (line[0] == '@') {
2294                if (ecbdata->diff_words)
2295                        diff_words_flush(ecbdata);
2296                len = sane_truncate_line(ecbdata, line, len);
2297                find_lno(line, ecbdata);
2298                emit_hunk_header(ecbdata, line, len);
2299                return;
2300        }
2301
2302        if (ecbdata->diff_words) {
2303                enum diff_symbol s =
2304                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2305                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2306                if (line[0] == '-') {
2307                        diff_words_append(line, len,
2308                                          &ecbdata->diff_words->minus);
2309                        return;
2310                } else if (line[0] == '+') {
2311                        diff_words_append(line, len,
2312                                          &ecbdata->diff_words->plus);
2313                        return;
2314                } else if (starts_with(line, "\\ ")) {
2315                        /*
2316                         * Eat the "no newline at eof" marker as if we
2317                         * saw a "+" or "-" line with nothing on it,
2318                         * and return without diff_words_flush() to
2319                         * defer processing. If this is the end of
2320                         * preimage, more "+" lines may come after it.
2321                         */
2322                        return;
2323                }
2324                diff_words_flush(ecbdata);
2325                emit_diff_symbol(o, s, line, len, 0);
2326                return;
2327        }
2328
2329        switch (line[0]) {
2330        case '+':
2331                ecbdata->lno_in_postimage++;
2332                emit_add_line(reset, ecbdata, line + 1, len - 1);
2333                break;
2334        case '-':
2335                ecbdata->lno_in_preimage++;
2336                emit_del_line(reset, ecbdata, line + 1, len - 1);
2337                break;
2338        case ' ':
2339                ecbdata->lno_in_postimage++;
2340                ecbdata->lno_in_preimage++;
2341                emit_context_line(reset, ecbdata, line + 1, len - 1);
2342                break;
2343        default:
2344                /* incomplete line at the end */
2345                ecbdata->lno_in_preimage++;
2346                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2347                                 line, len, 0);
2348                break;
2349        }
2350}
2351
2352static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2353{
2354        const char *old_name = a;
2355        const char *new_name = b;
2356        int pfx_length, sfx_length;
2357        int pfx_adjust_for_slash;
2358        int len_a = strlen(a);
2359        int len_b = strlen(b);
2360        int a_midlen, b_midlen;
2361        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2362        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2363
2364        if (qlen_a || qlen_b) {
2365                quote_c_style(a, name, NULL, 0);
2366                strbuf_addstr(name, " => ");
2367                quote_c_style(b, name, NULL, 0);
2368                return;
2369        }
2370
2371        /* Find common prefix */
2372        pfx_length = 0;
2373        while (*old_name && *new_name && *old_name == *new_name) {
2374                if (*old_name == '/')
2375                        pfx_length = old_name - a + 1;
2376                old_name++;
2377                new_name++;
2378        }
2379
2380        /* Find common suffix */
2381        old_name = a + len_a;
2382        new_name = b + len_b;
2383        sfx_length = 0;
2384        /*
2385         * If there is a common prefix, it must end in a slash.  In
2386         * that case we let this loop run 1 into the prefix to see the
2387         * same slash.
2388         *
2389         * If there is no common prefix, we cannot do this as it would
2390         * underrun the input strings.
2391         */
2392        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2393        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2394               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2395               *old_name == *new_name) {
2396                if (*old_name == '/')
2397                        sfx_length = len_a - (old_name - a);
2398                old_name--;
2399                new_name--;
2400        }
2401
2402        /*
2403         * pfx{mid-a => mid-b}sfx
2404         * {pfx-a => pfx-b}sfx
2405         * pfx{sfx-a => sfx-b}
2406         * name-a => name-b
2407         */
2408        a_midlen = len_a - pfx_length - sfx_length;
2409        b_midlen = len_b - pfx_length - sfx_length;
2410        if (a_midlen < 0)
2411                a_midlen = 0;
2412        if (b_midlen < 0)
2413                b_midlen = 0;
2414
2415        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2416        if (pfx_length + sfx_length) {
2417                strbuf_add(name, a, pfx_length);
2418                strbuf_addch(name, '{');
2419        }
2420        strbuf_add(name, a + pfx_length, a_midlen);
2421        strbuf_addstr(name, " => ");
2422        strbuf_add(name, b + pfx_length, b_midlen);
2423        if (pfx_length + sfx_length) {
2424                strbuf_addch(name, '}');
2425                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2426        }
2427}
2428
2429struct diffstat_t {
2430        int nr;
2431        int alloc;
2432        struct diffstat_file {
2433                char *from_name;
2434                char *name;
2435                char *print_name;
2436                const char *comments;
2437                unsigned is_unmerged:1;
2438                unsigned is_binary:1;
2439                unsigned is_renamed:1;
2440                unsigned is_interesting:1;
2441                uintmax_t added, deleted;
2442        } **files;
2443};
2444
2445static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2446                                          const char *name_a,
2447                                          const char *name_b)
2448{
2449        struct diffstat_file *x;
2450        x = xcalloc(1, sizeof(*x));
2451        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2452        diffstat->files[diffstat->nr++] = x;
2453        if (name_b) {
2454                x->from_name = xstrdup(name_a);
2455                x->name = xstrdup(name_b);
2456                x->is_renamed = 1;
2457        }
2458        else {
2459                x->from_name = NULL;
2460                x->name = xstrdup(name_a);
2461        }
2462        return x;
2463}
2464
2465static void diffstat_consume(void *priv, char *line, unsigned long len)
2466{
2467        struct diffstat_t *diffstat = priv;
2468        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2469
2470        if (line[0] == '+')
2471                x->added++;
2472        else if (line[0] == '-')
2473                x->deleted++;
2474}
2475
2476const char mime_boundary_leader[] = "------------";
2477
2478static int scale_linear(int it, int width, int max_change)
2479{
2480        if (!it)
2481                return 0;
2482        /*
2483         * make sure that at least one '-' or '+' is printed if
2484         * there is any change to this path. The easiest way is to
2485         * scale linearly as if the alloted width is one column shorter
2486         * than it is, and then add 1 to the result.
2487         */
2488        return 1 + (it * (width - 1) / max_change);
2489}
2490
2491static void show_graph(struct strbuf *out, char ch, int cnt,
2492                       const char *set, const char *reset)
2493{
2494        if (cnt <= 0)
2495                return;
2496        strbuf_addstr(out, set);
2497        strbuf_addchars(out, ch, cnt);
2498        strbuf_addstr(out, reset);
2499}
2500
2501static void fill_print_name(struct diffstat_file *file)
2502{
2503        struct strbuf pname = STRBUF_INIT;
2504
2505        if (file->print_name)
2506                return;
2507
2508        if (file->is_renamed)
2509                pprint_rename(&pname, file->from_name, file->name);
2510        else
2511                quote_c_style(file->name, &pname, NULL, 0);
2512
2513        if (file->comments)
2514                strbuf_addf(&pname, " (%s)", file->comments);
2515
2516        file->print_name = strbuf_detach(&pname, NULL);
2517}
2518
2519static void print_stat_summary_inserts_deletes(struct diff_options *options,
2520                int files, int insertions, int deletions)
2521{
2522        struct strbuf sb = STRBUF_INIT;
2523
2524        if (!files) {
2525                assert(insertions == 0 && deletions == 0);
2526                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2527                                 NULL, 0, 0);
2528                return;
2529        }
2530
2531        strbuf_addf(&sb,
2532                    (files == 1) ? " %d file changed" : " %d files changed",
2533                    files);
2534
2535        /*
2536         * For binary diff, the caller may want to print "x files
2537         * changed" with insertions == 0 && deletions == 0.
2538         *
2539         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2540         * is probably less confusing (i.e skip over "2 files changed
2541         * but nothing about added/removed lines? Is this a bug in Git?").
2542         */
2543        if (insertions || deletions == 0) {
2544                strbuf_addf(&sb,
2545                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2546                            insertions);
2547        }
2548
2549        if (deletions || insertions == 0) {
2550                strbuf_addf(&sb,
2551                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2552                            deletions);
2553        }
2554        strbuf_addch(&sb, '\n');
2555        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2556                         sb.buf, sb.len, 0);
2557        strbuf_release(&sb);
2558}
2559
2560void print_stat_summary(FILE *fp, int files,
2561                        int insertions, int deletions)
2562{
2563        struct diff_options o;
2564        memset(&o, 0, sizeof(o));
2565        o.file = fp;
2566
2567        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2568}
2569
2570static void show_stats(struct diffstat_t *data, struct diff_options *options)
2571{
2572        int i, len, add, del, adds = 0, dels = 0;
2573        uintmax_t max_change = 0, max_len = 0;
2574        int total_files = data->nr, count;
2575        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2576        const char *reset, *add_c, *del_c;
2577        int extra_shown = 0;
2578        const char *line_prefix = diff_line_prefix(options);
2579        struct strbuf out = STRBUF_INIT;
2580
2581        if (data->nr == 0)
2582                return;
2583
2584        count = options->stat_count ? options->stat_count : data->nr;
2585
2586        reset = diff_get_color_opt(options, DIFF_RESET);
2587        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2588        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2589
2590        /*
2591         * Find the longest filename and max number of changes
2592         */
2593        for (i = 0; (i < count) && (i < data->nr); i++) {
2594                struct diffstat_file *file = data->files[i];
2595                uintmax_t change = file->added + file->deleted;
2596
2597                if (!file->is_interesting && (change == 0)) {
2598                        count++; /* not shown == room for one more */
2599                        continue;
2600                }
2601                fill_print_name(file);
2602                len = strlen(file->print_name);
2603                if (max_len < len)
2604                        max_len = len;
2605
2606                if (file->is_unmerged) {
2607                        /* "Unmerged" is 8 characters */
2608                        bin_width = bin_width < 8 ? 8 : bin_width;
2609                        continue;
2610                }
2611                if (file->is_binary) {
2612                        /* "Bin XXX -> YYY bytes" */
2613                        int w = 14 + decimal_width(file->added)
2614                                + decimal_width(file->deleted);
2615                        bin_width = bin_width < w ? w : bin_width;
2616                        /* Display change counts aligned with "Bin" */
2617                        number_width = 3;
2618                        continue;
2619                }
2620
2621                if (max_change < change)
2622                        max_change = change;
2623        }
2624        count = i; /* where we can stop scanning in data->files[] */
2625
2626        /*
2627         * We have width = stat_width or term_columns() columns total.
2628         * We want a maximum of min(max_len, stat_name_width) for the name part.
2629         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2630         * We also need 1 for " " and 4 + decimal_width(max_change)
2631         * for " | NNNN " and one the empty column at the end, altogether
2632         * 6 + decimal_width(max_change).
2633         *
2634         * If there's not enough space, we will use the smaller of
2635         * stat_name_width (if set) and 5/8*width for the filename,
2636         * and the rest for constant elements + graph part, but no more
2637         * than stat_graph_width for the graph part.
2638         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2639         * for the standard terminal size).
2640         *
2641         * In other words: stat_width limits the maximum width, and
2642         * stat_name_width fixes the maximum width of the filename,
2643         * and is also used to divide available columns if there
2644         * aren't enough.
2645         *
2646         * Binary files are displayed with "Bin XXX -> YYY bytes"
2647         * instead of the change count and graph. This part is treated
2648         * similarly to the graph part, except that it is not
2649         * "scaled". If total width is too small to accommodate the
2650         * guaranteed minimum width of the filename part and the
2651         * separators and this message, this message will "overflow"
2652         * making the line longer than the maximum width.
2653         */
2654
2655        if (options->stat_width == -1)
2656                width = term_columns() - strlen(line_prefix);
2657        else
2658                width = options->stat_width ? options->stat_width : 80;
2659        number_width = decimal_width(max_change) > number_width ?
2660                decimal_width(max_change) : number_width;
2661
2662        if (options->stat_graph_width == -1)
2663                options->stat_graph_width = diff_stat_graph_width;
2664
2665        /*
2666         * Guarantee 3/8*16==6 for the graph part
2667         * and 5/8*16==10 for the filename part
2668         */
2669        if (width < 16 + 6 + number_width)
2670                width = 16 + 6 + number_width;
2671
2672        /*
2673         * First assign sizes that are wanted, ignoring available width.
2674         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2675         * starting from "XXX" should fit in graph_width.
2676         */
2677        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2678        if (options->stat_graph_width &&
2679            options->stat_graph_width < graph_width)
2680                graph_width = options->stat_graph_width;
2681
2682        name_width = (options->stat_name_width > 0 &&
2683                      options->stat_name_width < max_len) ?
2684                options->stat_name_width : max_len;
2685
2686        /*
2687         * Adjust adjustable widths not to exceed maximum width
2688         */
2689        if (name_width + number_width + 6 + graph_width > width) {
2690                if (graph_width > width * 3/8 - number_width - 6) {
2691                        graph_width = width * 3/8 - number_width - 6;
2692                        if (graph_width < 6)
2693                                graph_width = 6;
2694                }
2695
2696                if (options->stat_graph_width &&
2697                    graph_width > options->stat_graph_width)
2698                        graph_width = options->stat_graph_width;
2699                if (name_width > width - number_width - 6 - graph_width)
2700                        name_width = width - number_width - 6 - graph_width;
2701                else
2702                        graph_width = width - number_width - 6 - name_width;
2703        }
2704
2705        /*
2706         * From here name_width is the width of the name area,
2707         * and graph_width is the width of the graph area.
2708         * max_change is used to scale graph properly.
2709         */
2710        for (i = 0; i < count; i++) {
2711                const char *prefix = "";
2712                struct diffstat_file *file = data->files[i];
2713                char *name = file->print_name;
2714                uintmax_t added = file->added;
2715                uintmax_t deleted = file->deleted;
2716                int name_len;
2717
2718                if (!file->is_interesting && (added + deleted == 0))
2719                        continue;
2720
2721                /*
2722                 * "scale" the filename
2723                 */
2724                len = name_width;
2725                name_len = strlen(name);
2726                if (name_width < name_len) {
2727                        char *slash;
2728                        prefix = "...";
2729                        len -= 3;
2730                        name += name_len - len;
2731                        slash = strchr(name, '/');
2732                        if (slash)
2733                                name = slash;
2734                }
2735
2736                if (file->is_binary) {
2737                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2738                        strbuf_addf(&out, " %*s", number_width, "Bin");
2739                        if (!added && !deleted) {
2740                                strbuf_addch(&out, '\n');
2741                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2742                                                 out.buf, out.len, 0);
2743                                strbuf_reset(&out);
2744                                continue;
2745                        }
2746                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2747                                del_c, deleted, reset);
2748                        strbuf_addstr(&out, " -> ");
2749                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2750                                add_c, added, reset);
2751                        strbuf_addstr(&out, " bytes\n");
2752                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2753                                         out.buf, out.len, 0);
2754                        strbuf_reset(&out);
2755                        continue;
2756                }
2757                else if (file->is_unmerged) {
2758                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2759                        strbuf_addstr(&out, " Unmerged\n");
2760                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2761                                         out.buf, out.len, 0);
2762                        strbuf_reset(&out);
2763                        continue;
2764                }
2765
2766                /*
2767                 * scale the add/delete
2768                 */
2769                add = added;
2770                del = deleted;
2771
2772                if (graph_width <= max_change) {
2773                        int total = scale_linear(add + del, graph_width, max_change);
2774                        if (total < 2 && add && del)
2775                                /* width >= 2 due to the sanity check */
2776                                total = 2;
2777                        if (add < del) {
2778                                add = scale_linear(add, graph_width, max_change);
2779                                del = total - add;
2780                        } else {
2781                                del = scale_linear(del, graph_width, max_change);
2782                                add = total - del;
2783                        }
2784                }
2785                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2786                strbuf_addf(&out, " %*"PRIuMAX"%s",
2787                        number_width, added + deleted,
2788                        added + deleted ? " " : "");
2789                show_graph(&out, '+', add, add_c, reset);
2790                show_graph(&out, '-', del, del_c, reset);
2791                strbuf_addch(&out, '\n');
2792                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2793                                 out.buf, out.len, 0);
2794                strbuf_reset(&out);
2795        }
2796
2797        for (i = 0; i < data->nr; i++) {
2798                struct diffstat_file *file = data->files[i];
2799                uintmax_t added = file->added;
2800                uintmax_t deleted = file->deleted;
2801
2802                if (file->is_unmerged ||
2803                    (!file->is_interesting && (added + deleted == 0))) {
2804                        total_files--;
2805                        continue;
2806                }
2807
2808                if (!file->is_binary) {
2809                        adds += added;
2810                        dels += deleted;
2811                }
2812                if (i < count)
2813                        continue;
2814                if (!extra_shown)
2815                        emit_diff_symbol(options,
2816                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2817                                         NULL, 0, 0);
2818                extra_shown = 1;
2819        }
2820
2821        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2822        strbuf_release(&out);
2823}
2824
2825static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2826{
2827        int i, adds = 0, dels = 0, total_files = data->nr;
2828
2829        if (data->nr == 0)
2830                return;
2831
2832        for (i = 0; i < data->nr; i++) {
2833                int added = data->files[i]->added;
2834                int deleted = data->files[i]->deleted;
2835
2836                if (data->files[i]->is_unmerged ||
2837                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2838                        total_files--;
2839                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2840                        adds += added;
2841                        dels += deleted;
2842                }
2843        }
2844        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2845}
2846
2847static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2848{
2849        int i;
2850
2851        if (data->nr == 0)
2852                return;
2853
2854        for (i = 0; i < data->nr; i++) {
2855                struct diffstat_file *file = data->files[i];
2856
2857                fprintf(options->file, "%s", diff_line_prefix(options));
2858
2859                if (file->is_binary)
2860                        fprintf(options->file, "-\t-\t");
2861                else
2862                        fprintf(options->file,
2863                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2864                                file->added, file->deleted);
2865                if (options->line_termination) {
2866                        fill_print_name(file);
2867                        if (!file->is_renamed)
2868                                write_name_quoted(file->name, options->file,
2869                                                  options->line_termination);
2870                        else {
2871                                fputs(file->print_name, options->file);
2872                                putc(options->line_termination, options->file);
2873                        }
2874                } else {
2875                        if (file->is_renamed) {
2876                                putc('\0', options->file);
2877                                write_name_quoted(file->from_name, options->file, '\0');
2878                        }
2879                        write_name_quoted(file->name, options->file, '\0');
2880                }
2881        }
2882}
2883
2884struct dirstat_file {
2885        const char *name;
2886        unsigned long changed;
2887};
2888
2889struct dirstat_dir {
2890        struct dirstat_file *files;
2891        int alloc, nr, permille, cumulative;
2892};
2893
2894static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2895                unsigned long changed, const char *base, int baselen)
2896{
2897        unsigned long sum_changes = 0;
2898        unsigned int sources = 0;
2899        const char *line_prefix = diff_line_prefix(opt);
2900
2901        while (dir->nr) {
2902                struct dirstat_file *f = dir->files;
2903                int namelen = strlen(f->name);
2904                unsigned long changes;
2905                char *slash;
2906
2907                if (namelen < baselen)
2908                        break;
2909                if (memcmp(f->name, base, baselen))
2910                        break;
2911                slash = strchr(f->name + baselen, '/');
2912                if (slash) {
2913                        int newbaselen = slash + 1 - f->name;
2914                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2915                        sources++;
2916                } else {
2917                        changes = f->changed;
2918                        dir->files++;
2919                        dir->nr--;
2920                        sources += 2;
2921                }
2922                sum_changes += changes;
2923        }
2924
2925        /*
2926         * We don't report dirstat's for
2927         *  - the top level
2928         *  - or cases where everything came from a single directory
2929         *    under this directory (sources == 1).
2930         */
2931        if (baselen && sources != 1) {
2932                if (sum_changes) {
2933                        int permille = sum_changes * 1000 / changed;
2934                        if (permille >= dir->permille) {
2935                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2936                                        permille / 10, permille % 10, baselen, base);
2937                                if (!dir->cumulative)
2938                                        return 0;
2939                        }
2940                }
2941        }
2942        return sum_changes;
2943}
2944
2945static int dirstat_compare(const void *_a, const void *_b)
2946{
2947        const struct dirstat_file *a = _a;
2948        const struct dirstat_file *b = _b;
2949        return strcmp(a->name, b->name);
2950}
2951
2952static void show_dirstat(struct diff_options *options)
2953{
2954        int i;
2955        unsigned long changed;
2956        struct dirstat_dir dir;
2957        struct diff_queue_struct *q = &diff_queued_diff;
2958
2959        dir.files = NULL;
2960        dir.alloc = 0;
2961        dir.nr = 0;
2962        dir.permille = options->dirstat_permille;
2963        dir.cumulative = options->flags.dirstat_cumulative;
2964
2965        changed = 0;
2966        for (i = 0; i < q->nr; i++) {
2967                struct diff_filepair *p = q->queue[i];
2968                const char *name;
2969                unsigned long copied, added, damage;
2970
2971                name = p->two->path ? p->two->path : p->one->path;
2972
2973                if (p->one->oid_valid && p->two->oid_valid &&
2974                    oideq(&p->one->oid, &p->two->oid)) {
2975                        /*
2976                         * The SHA1 has not changed, so pre-/post-content is
2977                         * identical. We can therefore skip looking at the
2978                         * file contents altogether.
2979                         */
2980                        damage = 0;
2981                        goto found_damage;
2982                }
2983
2984                if (options->flags.dirstat_by_file) {
2985                        /*
2986                         * In --dirstat-by-file mode, we don't really need to
2987                         * look at the actual file contents at all.
2988                         * The fact that the SHA1 changed is enough for us to
2989                         * add this file to the list of results
2990                         * (with each file contributing equal damage).
2991                         */
2992                        damage = 1;
2993                        goto found_damage;
2994                }
2995
2996                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2997                        diff_populate_filespec(options->repo, p->one, 0);
2998                        diff_populate_filespec(options->repo, p->two, 0);
2999                        diffcore_count_changes(options->repo,
3000                                               p->one, p->two, NULL, NULL,
3001                                               &copied, &added);
3002                        diff_free_filespec_data(p->one);
3003                        diff_free_filespec_data(p->two);
3004                } else if (DIFF_FILE_VALID(p->one)) {
3005                        diff_populate_filespec(options->repo, p->one, CHECK_SIZE_ONLY);
3006                        copied = added = 0;
3007                        diff_free_filespec_data(p->one);
3008                } else if (DIFF_FILE_VALID(p->two)) {
3009                        diff_populate_filespec(options->repo, p->two, CHECK_SIZE_ONLY);
3010                        copied = 0;
3011                        added = p->two->size;
3012                        diff_free_filespec_data(p->two);
3013                } else
3014                        continue;
3015
3016                /*
3017                 * Original minus copied is the removed material,
3018                 * added is the new material.  They are both damages
3019                 * made to the preimage.
3020                 * If the resulting damage is zero, we know that
3021                 * diffcore_count_changes() considers the two entries to
3022                 * be identical, but since the oid changed, we
3023                 * know that there must have been _some_ kind of change,
3024                 * so we force all entries to have damage > 0.
3025                 */
3026                damage = (p->one->size - copied) + added;
3027                if (!damage)
3028                        damage = 1;
3029
3030found_damage:
3031                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3032                dir.files[dir.nr].name = name;
3033                dir.files[dir.nr].changed = damage;
3034                changed += damage;
3035                dir.nr++;
3036        }
3037
3038        /* This can happen even with many files, if everything was renames */
3039        if (!changed)
3040                return;
3041
3042        /* Show all directories with more than x% of the changes */
3043        QSORT(dir.files, dir.nr, dirstat_compare);
3044        gather_dirstat(options, &dir, changed, "", 0);
3045}
3046
3047static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
3048{
3049        int i;
3050        unsigned long changed;
3051        struct dirstat_dir dir;
3052
3053        if (data->nr == 0)
3054                return;
3055
3056        dir.files = NULL;
3057        dir.alloc = 0;
3058        dir.nr = 0;
3059        dir.permille = options->dirstat_permille;
3060        dir.cumulative = options->flags.dirstat_cumulative;
3061
3062        changed = 0;
3063        for (i = 0; i < data->nr; i++) {
3064                struct diffstat_file *file = data->files[i];
3065                unsigned long damage = file->added + file->deleted;
3066                if (file->is_binary)
3067                        /*
3068                         * binary files counts bytes, not lines. Must find some
3069                         * way to normalize binary bytes vs. textual lines.
3070                         * The following heuristic assumes that there are 64
3071                         * bytes per "line".
3072                         * This is stupid and ugly, but very cheap...
3073                         */
3074                        damage = DIV_ROUND_UP(damage, 64);
3075                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3076                dir.files[dir.nr].name = file->name;
3077                dir.files[dir.nr].changed = damage;
3078                changed += damage;
3079                dir.nr++;
3080        }
3081
3082        /* This can happen even with many files, if everything was renames */
3083        if (!changed)
3084                return;
3085
3086        /* Show all directories with more than x% of the changes */
3087        QSORT(dir.files, dir.nr, dirstat_compare);
3088        gather_dirstat(options, &dir, changed, "", 0);
3089}
3090
3091static void free_diffstat_info(struct diffstat_t *diffstat)
3092{
3093        int i;
3094        for (i = 0; i < diffstat->nr; i++) {
3095                struct diffstat_file *f = diffstat->files[i];
3096                free(f->print_name);
3097                free(f->name);
3098                free(f->from_name);
3099                free(f);
3100        }
3101        free(diffstat->files);
3102}
3103
3104struct checkdiff_t {
3105        const char *filename;
3106        int lineno;
3107        int conflict_marker_size;
3108        struct diff_options *o;
3109        unsigned ws_rule;
3110        unsigned status;
3111};
3112
3113static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3114{
3115        char firstchar;
3116        int cnt;
3117
3118        if (len < marker_size + 1)
3119                return 0;
3120        firstchar = line[0];
3121        switch (firstchar) {
3122        case '=': case '>': case '<': case '|':
3123                break;
3124        default:
3125                return 0;
3126        }
3127        for (cnt = 1; cnt < marker_size; cnt++)
3128                if (line[cnt] != firstchar)
3129                        return 0;
3130        /* line[1] thru line[marker_size-1] are same as firstchar */
3131        if (len < marker_size + 1 || !isspace(line[marker_size]))
3132                return 0;
3133        return 1;
3134}
3135
3136static void checkdiff_consume_hunk(void *priv,
3137                                   long ob, long on, long nb, long nn,
3138                                   const char *func, long funclen)
3139
3140{
3141        struct checkdiff_t *data = priv;
3142        data->lineno = nb - 1;
3143}
3144
3145static void checkdiff_consume(void *priv, char *line, unsigned long len)
3146{
3147        struct checkdiff_t *data = priv;
3148        int marker_size = data->conflict_marker_size;
3149        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3150        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3151        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3152        char *err;
3153        const char *line_prefix;
3154
3155        assert(data->o);
3156        line_prefix = diff_line_prefix(data->o);
3157
3158        if (line[0] == '+') {
3159                unsigned bad;
3160                data->lineno++;
3161                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3162                        data->status |= 1;
3163                        fprintf(data->o->file,
3164                                "%s%s:%d: leftover conflict marker\n",
3165                                line_prefix, data->filename, data->lineno);
3166                }
3167                bad = ws_check(line + 1, len - 1, data->ws_rule);
3168                if (!bad)
3169                        return;
3170                data->status |= bad;
3171                err = whitespace_error_string(bad);
3172                fprintf(data->o->file, "%s%s:%d: %s.\n",
3173                        line_prefix, data->filename, data->lineno, err);
3174                free(err);
3175                emit_line(data->o, set, reset, line, 1);
3176                ws_check_emit(line + 1, len - 1, data->ws_rule,
3177                              data->o->file, set, reset, ws);
3178        } else if (line[0] == ' ') {
3179                data->lineno++;
3180        }
3181}
3182
3183static unsigned char *deflate_it(char *data,
3184                                 unsigned long size,
3185                                 unsigned long *result_size)
3186{
3187        int bound;
3188        unsigned char *deflated;
3189        git_zstream stream;
3190
3191        git_deflate_init(&stream, zlib_compression_level);
3192        bound = git_deflate_bound(&stream, size);
3193        deflated = xmalloc(bound);
3194        stream.next_out = deflated;
3195        stream.avail_out = bound;
3196
3197        stream.next_in = (unsigned char *)data;
3198        stream.avail_in = size;
3199        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3200                ; /* nothing */
3201        git_deflate_end(&stream);
3202        *result_size = stream.total_out;
3203        return deflated;
3204}
3205
3206static void emit_binary_diff_body(struct diff_options *o,
3207                                  mmfile_t *one, mmfile_t *two)
3208{
3209        void *cp;
3210        void *delta;
3211        void *deflated;
3212        void *data;
3213        unsigned long orig_size;
3214        unsigned long delta_size;
3215        unsigned long deflate_size;
3216        unsigned long data_size;
3217
3218        /* We could do deflated delta, or we could do just deflated two,
3219         * whichever is smaller.
3220         */
3221        delta = NULL;
3222        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3223        if (one->size && two->size) {
3224                delta = diff_delta(one->ptr, one->size,
3225                                   two->ptr, two->size,
3226                                   &delta_size, deflate_size);
3227                if (delta) {
3228                        void *to_free = delta;
3229                        orig_size = delta_size;
3230                        delta = deflate_it(delta, delta_size, &delta_size);
3231                        free(to_free);
3232                }
3233        }
3234
3235        if (delta && delta_size < deflate_size) {
3236                char *s = xstrfmt("%"PRIuMAX , (uintmax_t)orig_size);
3237                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3238                                 s, strlen(s), 0);
3239                free(s);
3240                free(deflated);
3241                data = delta;
3242                data_size = delta_size;
3243        } else {
3244                char *s = xstrfmt("%lu", two->size);
3245                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3246                                 s, strlen(s), 0);
3247                free(s);
3248                free(delta);
3249                data = deflated;
3250                data_size = deflate_size;
3251        }
3252
3253        /* emit data encoded in base85 */
3254        cp = data;
3255        while (data_size) {
3256                int len;
3257                int bytes = (52 < data_size) ? 52 : data_size;
3258                char line[71];
3259                data_size -= bytes;
3260                if (bytes <= 26)
3261                        line[0] = bytes + 'A' - 1;
3262                else
3263                        line[0] = bytes - 26 + 'a' - 1;
3264                encode_85(line + 1, cp, bytes);
3265                cp = (char *) cp + bytes;
3266
3267                len = strlen(line);
3268                line[len++] = '\n';
3269                line[len] = '\0';
3270
3271                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3272                                 line, len, 0);
3273        }
3274        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3275        free(data);
3276}
3277
3278static void emit_binary_diff(struct diff_options *o,
3279                             mmfile_t *one, mmfile_t *two)
3280{
3281        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3282        emit_binary_diff_body(o, one, two);
3283        emit_binary_diff_body(o, two, one);
3284}
3285
3286int diff_filespec_is_binary(struct repository *r,
3287                            struct diff_filespec *one)
3288{
3289        if (one->is_binary == -1) {
3290                diff_filespec_load_driver(one, r->index);
3291                if (one->driver->binary != -1)
3292                        one->is_binary = one->driver->binary;
3293                else {
3294                        if (!one->data && DIFF_FILE_VALID(one))
3295                                diff_populate_filespec(r, one, CHECK_BINARY);
3296                        if (one->is_binary == -1 && one->data)
3297                                one->is_binary = buffer_is_binary(one->data,
3298                                                one->size);
3299                        if (one->is_binary == -1)
3300                                one->is_binary = 0;
3301                }
3302        }
3303        return one->is_binary;
3304}
3305
3306static const struct userdiff_funcname *
3307diff_funcname_pattern(struct diff_options *o, struct diff_filespec *one)
3308{
3309        diff_filespec_load_driver(one, o->repo->index);
3310        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3311}
3312
3313void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3314{
3315        if (!options->a_prefix)
3316                options->a_prefix = a;
3317        if (!options->b_prefix)
3318                options->b_prefix = b;
3319}
3320
3321struct userdiff_driver *get_textconv(struct repository *r,
3322                                     struct diff_filespec *one)
3323{
3324        if (!DIFF_FILE_VALID(one))
3325                return NULL;
3326
3327        diff_filespec_load_driver(one, r->index);
3328        return userdiff_get_textconv(r, one->driver);
3329}
3330
3331static void builtin_diff(const char *name_a,
3332                         const char *name_b,
3333                         struct diff_filespec *one,
3334                         struct diff_filespec *two,
3335                         const char *xfrm_msg,
3336                         int must_show_header,
3337                         struct diff_options *o,
3338                         int complete_rewrite)
3339{
3340        mmfile_t mf1, mf2;
3341        const char *lbl[2];
3342        char *a_one, *b_two;
3343        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3344        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3345        const char *a_prefix, *b_prefix;
3346        struct userdiff_driver *textconv_one = NULL;
3347        struct userdiff_driver *textconv_two = NULL;
3348        struct strbuf header = STRBUF_INIT;
3349        const char *line_prefix = diff_line_prefix(o);
3350
3351        diff_set_mnemonic_prefix(o, "a/", "b/");
3352        if (o->flags.reverse_diff) {
3353                a_prefix = o->b_prefix;
3354                b_prefix = o->a_prefix;
3355        } else {
3356                a_prefix = o->a_prefix;
3357                b_prefix = o->b_prefix;
3358        }
3359
3360        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3361            (!one->mode || S_ISGITLINK(one->mode)) &&
3362            (!two->mode || S_ISGITLINK(two->mode))) {
3363                show_submodule_summary(o, one->path ? one->path : two->path,
3364                                &one->oid, &two->oid,
3365                                two->dirty_submodule);
3366                return;
3367        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3368                   (!one->mode || S_ISGITLINK(one->mode)) &&
3369                   (!two->mode || S_ISGITLINK(two->mode))) {
3370                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3371                                &one->oid, &two->oid,
3372                                two->dirty_submodule);
3373                return;
3374        }
3375
3376        if (o->flags.allow_textconv) {
3377                textconv_one = get_textconv(o->repo, one);
3378                textconv_two = get_textconv(o->repo, two);
3379        }
3380
3381        /* Never use a non-valid filename anywhere if at all possible */
3382        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3383        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3384
3385        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3386        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3387        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3388        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3389        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3390        if (lbl[0][0] == '/') {
3391                /* /dev/null */
3392                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3393                if (xfrm_msg)
3394                        strbuf_addstr(&header, xfrm_msg);
3395                must_show_header = 1;
3396        }
3397        else if (lbl[1][0] == '/') {
3398                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3399                if (xfrm_msg)
3400                        strbuf_addstr(&header, xfrm_msg);
3401                must_show_header = 1;
3402        }
3403        else {
3404                if (one->mode != two->mode) {
3405                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3406                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3407                        must_show_header = 1;
3408                }
3409                if (xfrm_msg)
3410                        strbuf_addstr(&header, xfrm_msg);
3411
3412                /*
3413                 * we do not run diff between different kind
3414                 * of objects.
3415                 */
3416                if ((one->mode ^ two->mode) & S_IFMT)
3417                        goto free_ab_and_return;
3418                if (complete_rewrite &&
3419                    (textconv_one || !diff_filespec_is_binary(o->repo, one)) &&
3420                    (textconv_two || !diff_filespec_is_binary(o->repo, two))) {
3421                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3422                                         header.buf, header.len, 0);
3423                        strbuf_reset(&header);
3424                        emit_rewrite_diff(name_a, name_b, one, two,
3425                                          textconv_one, textconv_two, o);
3426                        o->found_changes = 1;
3427                        goto free_ab_and_return;
3428                }
3429        }
3430
3431        if (o->irreversible_delete && lbl[1][0] == '/') {
3432                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3433                                 header.len, 0);
3434                strbuf_reset(&header);
3435                goto free_ab_and_return;
3436        } else if (!o->flags.text &&
3437                   ( (!textconv_one && diff_filespec_is_binary(o->repo, one)) ||
3438                     (!textconv_two && diff_filespec_is_binary(o->repo, two)) )) {
3439                struct strbuf sb = STRBUF_INIT;
3440                if (!one->data && !two->data &&
3441                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3442                    !o->flags.binary) {
3443                        if (oideq(&one->oid, &two->oid)) {
3444                                if (must_show_header)
3445                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3446                                                         header.buf, header.len,
3447                                                         0);
3448                                goto free_ab_and_return;
3449                        }
3450                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3451                                         header.buf, header.len, 0);
3452                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3453                                    diff_line_prefix(o), lbl[0], lbl[1]);
3454                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3455                                         sb.buf, sb.len, 0);
3456                        strbuf_release(&sb);
3457                        goto free_ab_and_return;
3458                }
3459                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3460                    fill_mmfile(o->repo, &mf2, two) < 0)
3461                        die("unable to read files to diff");
3462                /* Quite common confusing case */
3463                if (mf1.size == mf2.size &&
3464                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3465                        if (must_show_header)
3466                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3467                                                 header.buf, header.len, 0);
3468                        goto free_ab_and_return;
3469                }
3470                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3471                strbuf_reset(&header);
3472                if (o->flags.binary)
3473                        emit_binary_diff(o, &mf1, &mf2);
3474                else {
3475                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3476                                    diff_line_prefix(o), lbl[0], lbl[1]);
3477                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3478                                         sb.buf, sb.len, 0);
3479                        strbuf_release(&sb);
3480                }
3481                o->found_changes = 1;
3482        } else {
3483                /* Crazy xdl interfaces.. */
3484                const char *diffopts = getenv("GIT_DIFF_OPTS");
3485                const char *v;
3486                xpparam_t xpp;
3487                xdemitconf_t xecfg;
3488                struct emit_callback ecbdata;
3489                const struct userdiff_funcname *pe;
3490
3491                if (must_show_header) {
3492                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3493                                         header.buf, header.len, 0);
3494                        strbuf_reset(&header);
3495                }
3496
3497                mf1.size = fill_textconv(o->repo, textconv_one, one, &mf1.ptr);
3498                mf2.size = fill_textconv(o->repo, textconv_two, two, &mf2.ptr);
3499
3500                pe = diff_funcname_pattern(o, one);
3501                if (!pe)
3502                        pe = diff_funcname_pattern(o, two);
3503
3504                memset(&xpp, 0, sizeof(xpp));
3505                memset(&xecfg, 0, sizeof(xecfg));
3506                memset(&ecbdata, 0, sizeof(ecbdata));
3507                if (o->flags.suppress_diff_headers)
3508                        lbl[0] = NULL;
3509                ecbdata.label_path = lbl;
3510                ecbdata.color_diff = want_color(o->use_color);
3511                ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
3512                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3513                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3514                ecbdata.opt = o;
3515                if (header.len && !o->flags.suppress_diff_headers)
3516                        ecbdata.header = &header;
3517                xpp.flags = o->xdl_opts;
3518                xpp.anchors = o->anchors;
3519                xpp.anchors_nr = o->anchors_nr;
3520                xecfg.ctxlen = o->context;
3521                xecfg.interhunkctxlen = o->interhunkcontext;
3522                xecfg.flags = XDL_EMIT_FUNCNAMES;
3523                if (o->flags.funccontext)
3524                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3525                if (pe)
3526                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3527                if (!diffopts)
3528                        ;
3529                else if (skip_prefix(diffopts, "--unified=", &v))
3530                        xecfg.ctxlen = strtoul(v, NULL, 10);
3531                else if (skip_prefix(diffopts, "-u", &v))
3532                        xecfg.ctxlen = strtoul(v, NULL, 10);
3533                if (o->word_diff)
3534                        init_diff_words_data(&ecbdata, o, one, two);
3535                if (xdi_diff_outf(&mf1, &mf2, NULL, fn_out_consume,
3536                                  &ecbdata, &xpp, &xecfg))
3537                        die("unable to generate diff for %s", one->path);
3538                if (o->word_diff)
3539                        free_diff_words_data(&ecbdata);
3540                if (textconv_one)
3541                        free(mf1.ptr);
3542                if (textconv_two)
3543                        free(mf2.ptr);
3544                xdiff_clear_find_func(&xecfg);
3545        }
3546
3547 free_ab_and_return:
3548        strbuf_release(&header);
3549        diff_free_filespec_data(one);
3550        diff_free_filespec_data(two);
3551        free(a_one);
3552        free(b_two);
3553        return;
3554}
3555
3556static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3557{
3558        if (!is_renamed) {
3559                if (p->status == DIFF_STATUS_ADDED) {
3560                        if (S_ISLNK(p->two->mode))
3561                                return "new +l";
3562                        else if ((p->two->mode & 0777) == 0755)
3563                                return "new +x";
3564                        else
3565                                return "new";
3566                } else if (p->status == DIFF_STATUS_DELETED)
3567                        return "gone";
3568        }
3569        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3570                return "mode -l";
3571        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3572                return "mode +l";
3573        else if ((p->one->mode & 0777) == 0644 &&
3574                 (p->two->mode & 0777) == 0755)
3575                return "mode +x";
3576        else if ((p->one->mode & 0777) == 0755 &&
3577                 (p->two->mode & 0777) == 0644)
3578                return "mode -x";
3579        return NULL;
3580}
3581
3582static void builtin_diffstat(const char *name_a, const char *name_b,
3583                             struct diff_filespec *one,
3584                             struct diff_filespec *two,
3585                             struct diffstat_t *diffstat,
3586                             struct diff_options *o,
3587                             struct diff_filepair *p)
3588{
3589        mmfile_t mf1, mf2;
3590        struct diffstat_file *data;
3591        int same_contents;
3592        int complete_rewrite = 0;
3593
3594        if (!DIFF_PAIR_UNMERGED(p)) {
3595                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3596                        complete_rewrite = 1;
3597        }
3598
3599        data = diffstat_add(diffstat, name_a, name_b);
3600        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3601        if (o->flags.stat_with_summary)
3602                data->comments = get_compact_summary(p, data->is_renamed);
3603
3604        if (!one || !two) {
3605                data->is_unmerged = 1;
3606                return;
3607        }
3608
3609        same_contents = oideq(&one->oid, &two->oid);
3610
3611        if (diff_filespec_is_binary(o->repo, one) ||
3612            diff_filespec_is_binary(o->repo, two)) {
3613                data->is_binary = 1;
3614                if (same_contents) {
3615                        data->added = 0;
3616                        data->deleted = 0;
3617                } else {
3618                        data->added = diff_filespec_size(o->repo, two);
3619                        data->deleted = diff_filespec_size(o->repo, one);
3620                }
3621        }
3622
3623        else if (complete_rewrite) {
3624                diff_populate_filespec(o->repo, one, 0);
3625                diff_populate_filespec(o->repo, two, 0);
3626                data->deleted = count_lines(one->data, one->size);
3627                data->added = count_lines(two->data, two->size);
3628        }
3629
3630        else if (!same_contents) {
3631                /* Crazy xdl interfaces.. */
3632                xpparam_t xpp;
3633                xdemitconf_t xecfg;
3634
3635                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3636                    fill_mmfile(o->repo, &mf2, two) < 0)
3637                        die("unable to read files to diff");
3638
3639                memset(&xpp, 0, sizeof(xpp));
3640                memset(&xecfg, 0, sizeof(xecfg));
3641                xpp.flags = o->xdl_opts;
3642                xpp.anchors = o->anchors;
3643                xpp.anchors_nr = o->anchors_nr;
3644                xecfg.ctxlen = o->context;
3645                xecfg.interhunkctxlen = o->interhunkcontext;
3646                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
3647                                  diffstat_consume, diffstat, &xpp, &xecfg))
3648                        die("unable to generate diffstat for %s", one->path);
3649        }
3650
3651        diff_free_filespec_data(one);
3652        diff_free_filespec_data(two);
3653}
3654
3655static void builtin_checkdiff(const char *name_a, const char *name_b,
3656                              const char *attr_path,
3657                              struct diff_filespec *one,
3658                              struct diff_filespec *two,
3659                              struct diff_options *o)
3660{
3661        mmfile_t mf1, mf2;
3662        struct checkdiff_t data;
3663
3664        if (!two)
3665                return;
3666
3667        memset(&data, 0, sizeof(data));
3668        data.filename = name_b ? name_b : name_a;
3669        data.lineno = 0;
3670        data.o = o;
3671        data.ws_rule = whitespace_rule(o->repo->index, attr_path);
3672        data.conflict_marker_size = ll_merge_marker_size(o->repo->index, attr_path);
3673
3674        if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3675            fill_mmfile(o->repo, &mf2, two) < 0)
3676                die("unable to read files to diff");
3677
3678        /*
3679         * All the other codepaths check both sides, but not checking
3680         * the "old" side here is deliberate.  We are checking the newly
3681         * introduced changes, and as long as the "new" side is text, we
3682         * can and should check what it introduces.
3683         */
3684        if (diff_filespec_is_binary(o->repo, two))
3685                goto free_and_return;
3686        else {
3687                /* Crazy xdl interfaces.. */
3688                xpparam_t xpp;
3689                xdemitconf_t xecfg;
3690
3691                memset(&xpp, 0, sizeof(xpp));
3692                memset(&xecfg, 0, sizeof(xecfg));
3693                xecfg.ctxlen = 1; /* at least one context line */
3694                xpp.flags = 0;
3695                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume_hunk,
3696                                  checkdiff_consume, &data,
3697                                  &xpp, &xecfg))
3698                        die("unable to generate checkdiff for %s", one->path);
3699
3700                if (data.ws_rule & WS_BLANK_AT_EOF) {
3701                        struct emit_callback ecbdata;
3702                        int blank_at_eof;
3703
3704                        ecbdata.ws_rule = data.ws_rule;
3705                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3706                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3707
3708                        if (blank_at_eof) {
3709                                static char *err;
3710                                if (!err)
3711                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3712                                fprintf(o->file, "%s:%d: %s.\n",
3713                                        data.filename, blank_at_eof, err);
3714                                data.status = 1; /* report errors */
3715                        }
3716                }
3717        }
3718 free_and_return:
3719        diff_free_filespec_data(one);
3720        diff_free_filespec_data(two);
3721        if (data.status)
3722                o->flags.check_failed = 1;
3723}
3724
3725struct diff_filespec *alloc_filespec(const char *path)
3726{
3727        struct diff_filespec *spec;
3728
3729        FLEXPTR_ALLOC_STR(spec, path, path);
3730        spec->count = 1;
3731        spec->is_binary = -1;
3732        return spec;
3733}
3734
3735void free_filespec(struct diff_filespec *spec)
3736{
3737        if (!--spec->count) {
3738                diff_free_filespec_data(spec);
3739                free(spec);
3740        }
3741}
3742
3743void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3744                   int oid_valid, unsigned short mode)
3745{
3746        if (mode) {
3747                spec->mode = canon_mode(mode);
3748                oidcpy(&spec->oid, oid);
3749                spec->oid_valid = oid_valid;
3750        }
3751}
3752
3753/*
3754 * Given a name and sha1 pair, if the index tells us the file in
3755 * the work tree has that object contents, return true, so that
3756 * prepare_temp_file() does not have to inflate and extract.
3757 */
3758static int reuse_worktree_file(struct index_state *istate,
3759                               const char *name,
3760                               const struct object_id *oid,
3761                               int want_file)
3762{
3763        const struct cache_entry *ce;
3764        struct stat st;
3765        int pos, len;
3766
3767        /*
3768         * We do not read the cache ourselves here, because the
3769         * benchmark with my previous version that always reads cache
3770         * shows that it makes things worse for diff-tree comparing
3771         * two linux-2.6 kernel trees in an already checked out work
3772         * tree.  This is because most diff-tree comparisons deal with
3773         * only a small number of files, while reading the cache is
3774         * expensive for a large project, and its cost outweighs the
3775         * savings we get by not inflating the object to a temporary
3776         * file.  Practically, this code only helps when we are used
3777         * by diff-cache --cached, which does read the cache before
3778         * calling us.
3779         */
3780        if (!istate->cache)
3781                return 0;
3782
3783        /* We want to avoid the working directory if our caller
3784         * doesn't need the data in a normal file, this system
3785         * is rather slow with its stat/open/mmap/close syscalls,
3786         * and the object is contained in a pack file.  The pack
3787         * is probably already open and will be faster to obtain
3788         * the data through than the working directory.  Loose
3789         * objects however would tend to be slower as they need
3790         * to be individually opened and inflated.
3791         */
3792        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3793                return 0;
3794
3795        /*
3796         * Similarly, if we'd have to convert the file contents anyway, that
3797         * makes the optimization not worthwhile.
3798         */
3799        if (!want_file && would_convert_to_git(istate, name))
3800                return 0;
3801
3802        len = strlen(name);
3803        pos = index_name_pos(istate, name, len);
3804        if (pos < 0)
3805                return 0;
3806        ce = istate->cache[pos];
3807
3808        /*
3809         * This is not the sha1 we are looking for, or
3810         * unreusable because it is not a regular file.
3811         */
3812        if (!oideq(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3813                return 0;
3814
3815        /*
3816         * If ce is marked as "assume unchanged", there is no
3817         * guarantee that work tree matches what we are looking for.
3818         */
3819        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3820                return 0;
3821
3822        /*
3823         * If ce matches the file in the work tree, we can reuse it.
3824         */
3825        if (ce_uptodate(ce) ||
3826            (!lstat(name, &st) && !ie_match_stat(istate, ce, &st, 0)))
3827                return 1;
3828
3829        return 0;
3830}
3831
3832static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3833{
3834        struct strbuf buf = STRBUF_INIT;
3835        char *dirty = "";
3836
3837        /* Are we looking at the work tree? */
3838        if (s->dirty_submodule)
3839                dirty = "-dirty";
3840
3841        strbuf_addf(&buf, "Subproject commit %s%s\n",
3842                    oid_to_hex(&s->oid), dirty);
3843        s->size = buf.len;
3844        if (size_only) {
3845                s->data = NULL;
3846                strbuf_release(&buf);
3847        } else {
3848                s->data = strbuf_detach(&buf, NULL);
3849                s->should_free = 1;
3850        }
3851        return 0;
3852}
3853
3854/*
3855 * While doing rename detection and pickaxe operation, we may need to
3856 * grab the data for the blob (or file) for our own in-core comparison.
3857 * diff_filespec has data and size fields for this purpose.
3858 */
3859int diff_populate_filespec(struct repository *r,
3860                           struct diff_filespec *s,
3861                           unsigned int flags)
3862{
3863        int size_only = flags & CHECK_SIZE_ONLY;
3864        int err = 0;
3865        int conv_flags = global_conv_flags_eol;
3866        /*
3867         * demote FAIL to WARN to allow inspecting the situation
3868         * instead of refusing.
3869         */
3870        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3871                conv_flags = CONV_EOL_RNDTRP_WARN;
3872
3873        if (!DIFF_FILE_VALID(s))
3874                die("internal error: asking to populate invalid file.");
3875        if (S_ISDIR(s->mode))
3876                return -1;
3877
3878        if (s->data)
3879                return 0;
3880
3881        if (size_only && 0 < s->size)
3882                return 0;
3883
3884        if (S_ISGITLINK(s->mode))
3885                return diff_populate_gitlink(s, size_only);
3886
3887        if (!s->oid_valid ||
3888            reuse_worktree_file(r->index, s->path, &s->oid, 0)) {
3889                struct strbuf buf = STRBUF_INIT;
3890                struct stat st;
3891                int fd;
3892
3893                if (lstat(s->path, &st) < 0) {
3894                err_empty:
3895                        err = -1;
3896                empty:
3897                        s->data = (char *)"";
3898                        s->size = 0;
3899                        return err;
3900                }
3901                s->size = xsize_t(st.st_size);
3902                if (!s->size)
3903                        goto empty;
3904                if (S_ISLNK(st.st_mode)) {
3905                        struct strbuf sb = STRBUF_INIT;
3906
3907                        if (strbuf_readlink(&sb, s->path, s->size))
3908                                goto err_empty;
3909                        s->size = sb.len;
3910                        s->data = strbuf_detach(&sb, NULL);
3911                        s->should_free = 1;
3912                        return 0;
3913                }
3914
3915                /*
3916                 * Even if the caller would be happy with getting
3917                 * only the size, we cannot return early at this
3918                 * point if the path requires us to run the content
3919                 * conversion.
3920                 */
3921                if (size_only && !would_convert_to_git(r->index, s->path))
3922                        return 0;
3923
3924                /*
3925                 * Note: this check uses xsize_t(st.st_size) that may
3926                 * not be the true size of the blob after it goes
3927                 * through convert_to_git().  This may not strictly be
3928                 * correct, but the whole point of big_file_threshold
3929                 * and is_binary check being that we want to avoid
3930                 * opening the file and inspecting the contents, this
3931                 * is probably fine.
3932                 */
3933                if ((flags & CHECK_BINARY) &&
3934                    s->size > big_file_threshold && s->is_binary == -1) {
3935                        s->is_binary = 1;
3936                        return 0;
3937                }
3938                fd = open(s->path, O_RDONLY);
3939                if (fd < 0)
3940                        goto err_empty;
3941                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3942                close(fd);
3943                s->should_munmap = 1;
3944
3945                /*
3946                 * Convert from working tree format to canonical git format
3947                 */
3948                if (convert_to_git(r->index, s->path, s->data, s->size, &buf, conv_flags)) {
3949                        size_t size = 0;
3950                        munmap(s->data, s->size);
3951                        s->should_munmap = 0;
3952                        s->data = strbuf_detach(&buf, &size);
3953                        s->size = size;
3954                        s->should_free = 1;
3955                }
3956        }
3957        else {
3958                enum object_type type;
3959                if (size_only || (flags & CHECK_BINARY)) {
3960                        type = oid_object_info(r, &s->oid, &s->size);
3961                        if (type < 0)
3962                                die("unable to read %s",
3963                                    oid_to_hex(&s->oid));
3964                        if (size_only)
3965                                return 0;
3966                        if (s->size > big_file_threshold && s->is_binary == -1) {
3967                                s->is_binary = 1;
3968                                return 0;
3969                        }
3970                }
3971                s->data = read_object_file(&s->oid, &type, &s->size);
3972                if (!s->data)
3973                        die("unable to read %s", oid_to_hex(&s->oid));
3974                s->should_free = 1;
3975        }
3976        return 0;
3977}
3978
3979void diff_free_filespec_blob(struct diff_filespec *s)
3980{
3981        if (s->should_free)
3982                free(s->data);
3983        else if (s->should_munmap)
3984                munmap(s->data, s->size);
3985
3986        if (s->should_free || s->should_munmap) {
3987                s->should_free = s->should_munmap = 0;
3988                s->data = NULL;
3989        }
3990}
3991
3992void diff_free_filespec_data(struct diff_filespec *s)
3993{
3994        diff_free_filespec_blob(s);
3995        FREE_AND_NULL(s->cnt_data);
3996}
3997
3998static void prep_temp_blob(struct index_state *istate,
3999                           const char *path, struct diff_tempfile *temp,
4000                           void *blob,
4001                           unsigned long size,
4002                           const struct object_id *oid,
4003                           int mode)
4004{
4005        struct strbuf buf = STRBUF_INIT;
4006        struct strbuf tempfile = STRBUF_INIT;
4007        char *path_dup = xstrdup(path);
4008        const char *base = basename(path_dup);
4009
4010        /* Generate "XXXXXX_basename.ext" */
4011        strbuf_addstr(&tempfile, "XXXXXX_");
4012        strbuf_addstr(&tempfile, base);
4013
4014        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
4015        if (!temp->tempfile)
4016                die_errno("unable to create temp-file");
4017        if (convert_to_working_tree(istate, path,
4018                        (const char *)blob, (size_t)size, &buf)) {
4019                blob = buf.buf;
4020                size = buf.len;
4021        }
4022        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
4023            close_tempfile_gently(temp->tempfile))
4024                die_errno("unable to write temp-file");
4025        temp->name = get_tempfile_path(temp->tempfile);
4026        oid_to_hex_r(temp->hex, oid);
4027        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
4028        strbuf_release(&buf);
4029        strbuf_release(&tempfile);
4030        free(path_dup);
4031}
4032
4033static struct diff_tempfile *prepare_temp_file(struct repository *r,
4034                                               const char *name,
4035                                               struct diff_filespec *one)
4036{
4037        struct diff_tempfile *temp = claim_diff_tempfile();
4038
4039        if (!DIFF_FILE_VALID(one)) {
4040        not_a_valid_file:
4041                /* A '-' entry produces this for file-2, and
4042                 * a '+' entry produces this for file-1.
4043                 */
4044                temp->name = "/dev/null";
4045                xsnprintf(temp->hex, sizeof(temp->hex), ".");
4046                xsnprintf(temp->mode, sizeof(temp->mode), ".");
4047                return temp;
4048        }
4049
4050        if (!S_ISGITLINK(one->mode) &&
4051            (!one->oid_valid ||
4052             reuse_worktree_file(r->index, name, &one->oid, 1))) {
4053                struct stat st;
4054                if (lstat(name, &st) < 0) {
4055                        if (errno == ENOENT)
4056                                goto not_a_valid_file;
4057                        die_errno("stat(%s)", name);
4058                }
4059                if (S_ISLNK(st.st_mode)) {
4060                        struct strbuf sb = STRBUF_INIT;
4061                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
4062                                die_errno("readlink(%s)", name);
4063                        prep_temp_blob(r->index, name, temp, sb.buf, sb.len,
4064                                       (one->oid_valid ?
4065                                        &one->oid : &null_oid),
4066                                       (one->oid_valid ?
4067                                        one->mode : S_IFLNK));
4068                        strbuf_release(&sb);
4069                }
4070                else {
4071                        /* we can borrow from the file in the work tree */
4072                        temp->name = name;
4073                        if (!one->oid_valid)
4074                                oid_to_hex_r(temp->hex, &null_oid);
4075                        else
4076                                oid_to_hex_r(temp->hex, &one->oid);
4077                        /* Even though we may sometimes borrow the
4078                         * contents from the work tree, we always want
4079                         * one->mode.  mode is trustworthy even when
4080                         * !(one->oid_valid), as long as
4081                         * DIFF_FILE_VALID(one).
4082                         */
4083                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
4084                }
4085                return temp;
4086        }
4087        else {
4088                if (diff_populate_filespec(r, one, 0))
4089                        die("cannot read data blob for %s", one->path);
4090                prep_temp_blob(r->index, name, temp,
4091                               one->data, one->size,
4092                               &one->oid, one->mode);
4093        }
4094        return temp;
4095}
4096
4097static void add_external_diff_name(struct repository *r,
4098                                   struct argv_array *argv,
4099                                   const char *name,
4100                                   struct diff_filespec *df)
4101{
4102        struct diff_tempfile *temp = prepare_temp_file(r, name, df);
4103        argv_array_push(argv, temp->name);
4104        argv_array_push(argv, temp->hex);
4105        argv_array_push(argv, temp->mode);
4106}
4107
4108/* An external diff command takes:
4109 *
4110 * diff-cmd name infile1 infile1-sha1 infile1-mode \
4111 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
4112 *
4113 */
4114static void run_external_diff(const char *pgm,
4115                              const char *name,
4116                              const char *other,
4117                              struct diff_filespec *one,
4118                              struct diff_filespec *two,
4119                              const char *xfrm_msg,
4120                              int complete_rewrite,
4121                              struct diff_options *o)
4122{
4123        struct argv_array argv = ARGV_ARRAY_INIT;
4124        struct argv_array env = ARGV_ARRAY_INIT;
4125        struct diff_queue_struct *q = &diff_queued_diff;
4126
4127        argv_array_push(&argv, pgm);
4128        argv_array_push(&argv, name);
4129
4130        if (one && two) {
4131                add_external_diff_name(o->repo, &argv, name, one);
4132                if (!other)
4133                        add_external_diff_name(o->repo, &argv, name, two);
4134                else {
4135                        add_external_diff_name(o->repo, &argv, other, two);
4136                        argv_array_push(&argv, other);
4137                        argv_array_push(&argv, xfrm_msg);
4138                }
4139        }
4140
4141        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4142        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4143
4144        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4145                die(_("external diff died, stopping at %s"), name);
4146
4147        remove_tempfile();
4148        argv_array_clear(&argv);
4149        argv_array_clear(&env);
4150}
4151
4152static int similarity_index(struct diff_filepair *p)
4153{
4154        return p->score * 100 / MAX_SCORE;
4155}
4156
4157static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4158{
4159        if (startup_info->have_repository)
4160                return find_unique_abbrev(oid, abbrev);
4161        else {
4162                char *hex = oid_to_hex(oid);
4163                if (abbrev < 0)
4164                        abbrev = FALLBACK_DEFAULT_ABBREV;
4165                if (abbrev > the_hash_algo->hexsz)
4166                        BUG("oid abbreviation out of range: %d", abbrev);
4167                if (abbrev)
4168                        hex[abbrev] = '\0';
4169                return hex;
4170        }
4171}
4172
4173static void fill_metainfo(struct strbuf *msg,
4174                          const char *name,
4175                          const char *other,
4176                          struct diff_filespec *one,
4177                          struct diff_filespec *two,
4178                          struct diff_options *o,
4179                          struct diff_filepair *p,
4180                          int *must_show_header,
4181                          int use_color)
4182{
4183        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4184        const char *reset = diff_get_color(use_color, DIFF_RESET);
4185        const char *line_prefix = diff_line_prefix(o);
4186
4187        *must_show_header = 1;
4188        strbuf_init(msg, PATH_MAX * 2 + 300);
4189        switch (p->status) {
4190        case DIFF_STATUS_COPIED:
4191                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4192                            line_prefix, set, similarity_index(p));
4193                strbuf_addf(msg, "%s\n%s%scopy from ",
4194                            reset,  line_prefix, set);
4195                quote_c_style(name, msg, NULL, 0);
4196                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4197                quote_c_style(other, msg, NULL, 0);
4198                strbuf_addf(msg, "%s\n", reset);
4199                break;
4200        case DIFF_STATUS_RENAMED:
4201                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4202                            line_prefix, set, similarity_index(p));
4203                strbuf_addf(msg, "%s\n%s%srename from ",
4204                            reset, line_prefix, set);
4205                quote_c_style(name, msg, NULL, 0);
4206                strbuf_addf(msg, "%s\n%s%srename to ",
4207                            reset, line_prefix, set);
4208                quote_c_style(other, msg, NULL, 0);
4209                strbuf_addf(msg, "%s\n", reset);
4210                break;
4211        case DIFF_STATUS_MODIFIED:
4212                if (p->score) {
4213                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4214                                    line_prefix,
4215                                    set, similarity_index(p), reset);
4216                        break;
4217                }
4218                /* fallthru */
4219        default:
4220                *must_show_header = 0;
4221        }
4222        if (one && two && !oideq(&one->oid, &two->oid)) {
4223                const unsigned hexsz = the_hash_algo->hexsz;
4224                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4225
4226                if (o->flags.binary) {
4227                        mmfile_t mf;
4228                        if ((!fill_mmfile(o->repo, &mf, one) &&
4229                             diff_filespec_is_binary(o->repo, one)) ||
4230                            (!fill_mmfile(o->repo, &mf, two) &&
4231                             diff_filespec_is_binary(o->repo, two)))
4232                                abbrev = hexsz;
4233                }
4234                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4235                            diff_abbrev_oid(&one->oid, abbrev),
4236                            diff_abbrev_oid(&two->oid, abbrev));
4237                if (one->mode == two->mode)
4238                        strbuf_addf(msg, " %06o", one->mode);
4239                strbuf_addf(msg, "%s\n", reset);
4240        }
4241}
4242
4243static void run_diff_cmd(const char *pgm,
4244                         const char *name,
4245                         const char *other,
4246                         const char *attr_path,
4247                         struct diff_filespec *one,
4248                         struct diff_filespec *two,
4249                         struct strbuf *msg,
4250                         struct diff_options *o,
4251                         struct diff_filepair *p)
4252{
4253        const char *xfrm_msg = NULL;
4254        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4255        int must_show_header = 0;
4256
4257
4258        if (o->flags.allow_external) {
4259                struct userdiff_driver *drv;
4260
4261                drv = userdiff_find_by_path(o->repo->index, attr_path);
4262                if (drv && drv->external)
4263                        pgm = drv->external;
4264        }
4265
4266        if (msg) {
4267                /*
4268                 * don't use colors when the header is intended for an
4269                 * external diff driver
4270                 */
4271                fill_metainfo(msg, name, other, one, two, o, p,
4272                              &must_show_header,
4273                              want_color(o->use_color) && !pgm);
4274                xfrm_msg = msg->len ? msg->buf : NULL;
4275        }
4276
4277        if (pgm) {
4278                run_external_diff(pgm, name, other, one, two, xfrm_msg,
4279                                  complete_rewrite, o);
4280                return;
4281        }
4282        if (one && two)
4283                builtin_diff(name, other ? other : name,
4284                             one, two, xfrm_msg, must_show_header,
4285                             o, complete_rewrite);
4286        else
4287                fprintf(o->file, "* Unmerged path %s\n", name);
4288}
4289
4290static void diff_fill_oid_info(struct diff_filespec *one, struct index_state *istate)
4291{
4292        if (DIFF_FILE_VALID(one)) {
4293                if (!one->oid_valid) {
4294                        struct stat st;
4295                        if (one->is_stdin) {
4296                                oidclr(&one->oid);
4297                                return;
4298                        }
4299                        if (lstat(one->path, &st) < 0)
4300                                die_errno("stat '%s'", one->path);
4301                        if (index_path(istate, &one->oid, one->path, &st, 0))
4302                                die("cannot hash %s", one->path);
4303                }
4304        }
4305        else
4306                oidclr(&one->oid);
4307}
4308
4309static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4310{
4311        /* Strip the prefix but do not molest /dev/null and absolute paths */
4312        if (*namep && !is_absolute_path(*namep)) {
4313                *namep += prefix_length;
4314                if (**namep == '/')
4315                        ++*namep;
4316        }
4317        if (*otherp && !is_absolute_path(*otherp)) {
4318                *otherp += prefix_length;
4319                if (**otherp == '/')
4320                        ++*otherp;
4321        }
4322}
4323
4324static void run_diff(struct diff_filepair *p, struct diff_options *o)
4325{
4326        const char *pgm = external_diff();
4327        struct strbuf msg;
4328        struct diff_filespec *one = p->one;
4329        struct diff_filespec *two = p->two;
4330        const char *name;
4331        const char *other;
4332        const char *attr_path;
4333
4334        name  = one->path;
4335        other = (strcmp(name, two->path) ? two->path : NULL);
4336        attr_path = name;
4337        if (o->prefix_length)
4338                strip_prefix(o->prefix_length, &name, &other);
4339
4340        if (!o->flags.allow_external)
4341                pgm = NULL;
4342
4343        if (DIFF_PAIR_UNMERGED(p)) {
4344                run_diff_cmd(pgm, name, NULL, attr_path,
4345                             NULL, NULL, NULL, o, p);
4346                return;
4347        }
4348
4349        diff_fill_oid_info(one, o->repo->index);
4350        diff_fill_oid_info(two, o->repo->index);
4351
4352        if (!pgm &&
4353            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4354            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4355                /*
4356                 * a filepair that changes between file and symlink
4357                 * needs to be split into deletion and creation.
4358                 */
4359                struct diff_filespec *null = alloc_filespec(two->path);
4360                run_diff_cmd(NULL, name, other, attr_path,
4361                             one, null, &msg,
4362                             o, p);
4363                free(null);
4364                strbuf_release(&msg);
4365
4366                null = alloc_filespec(one->path);
4367                run_diff_cmd(NULL, name, other, attr_path,
4368                             null, two, &msg, o, p);
4369                free(null);
4370        }
4371        else
4372                run_diff_cmd(pgm, name, other, attr_path,
4373                             one, two, &msg, o, p);
4374
4375        strbuf_release(&msg);
4376}
4377
4378static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4379                         struct diffstat_t *diffstat)
4380{
4381        const char *name;
4382        const char *other;
4383
4384        if (DIFF_PAIR_UNMERGED(p)) {
4385                /* unmerged */
4386                builtin_diffstat(p->one->path, NULL, NULL, NULL,
4387                                 diffstat, o, p);
4388                return;
4389        }
4390
4391        name = p->one->path;
4392        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4393
4394        if (o->prefix_length)
4395                strip_prefix(o->prefix_length, &name, &other);
4396
4397        diff_fill_oid_info(p->one, o->repo->index);
4398        diff_fill_oid_info(p->two, o->repo->index);
4399
4400        builtin_diffstat(name, other, p->one, p->two,
4401                         diffstat, o, p);
4402}
4403
4404static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4405{
4406        const char *name;
4407        const char *other;
4408        const char *attr_path;
4409
4410        if (DIFF_PAIR_UNMERGED(p)) {
4411                /* unmerged */
4412                return;
4413        }
4414
4415        name = p->one->path;
4416        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4417        attr_path = other ? other : name;
4418
4419        if (o->prefix_length)
4420                strip_prefix(o->prefix_length, &name, &other);
4421
4422        diff_fill_oid_info(p->one, o->repo->index);
4423        diff_fill_oid_info(p->two, o->repo->index);
4424
4425        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4426}
4427
4428void repo_diff_setup(struct repository *r, struct diff_options *options)
4429{
4430        memcpy(options, &default_diff_options, sizeof(*options));
4431
4432        options->file = stdout;
4433        options->repo = r;
4434
4435        options->output_indicators[OUTPUT_INDICATOR_NEW] = '+';
4436        options->output_indicators[OUTPUT_INDICATOR_OLD] = '-';
4437        options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = ' ';
4438        options->abbrev = DEFAULT_ABBREV;
4439        options->line_termination = '\n';
4440        options->break_opt = -1;
4441        options->rename_limit = -1;
4442        options->dirstat_permille = diff_dirstat_permille_default;
4443        options->context = diff_context_default;
4444        options->interhunkcontext = diff_interhunk_context_default;
4445        options->ws_error_highlight = ws_error_highlight_default;
4446        options->flags.rename_empty = 1;
4447        options->objfind = NULL;
4448
4449        /* pathchange left =NULL by default */
4450        options->change = diff_change;
4451        options->add_remove = diff_addremove;
4452        options->use_color = diff_use_color_default;
4453        options->detect_rename = diff_detect_rename_default;
4454        options->xdl_opts |= diff_algorithm;
4455        if (diff_indent_heuristic)
4456                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4457
4458        options->orderfile = diff_order_file_cfg;
4459
4460        if (diff_no_prefix) {
4461                options->a_prefix = options->b_prefix = "";
4462        } else if (!diff_mnemonic_prefix) {
4463                options->a_prefix = "a/";
4464                options->b_prefix = "b/";
4465        }
4466
4467        options->color_moved = diff_color_moved_default;
4468        options->color_moved_ws_handling = diff_color_moved_ws_default;
4469}
4470
4471void diff_setup_done(struct diff_options *options)
4472{
4473        unsigned check_mask = DIFF_FORMAT_NAME |
4474                              DIFF_FORMAT_NAME_STATUS |
4475                              DIFF_FORMAT_CHECKDIFF |
4476                              DIFF_FORMAT_NO_OUTPUT;
4477        /*
4478         * This must be signed because we're comparing against a potentially
4479         * negative value.
4480         */
4481        const int hexsz = the_hash_algo->hexsz;
4482
4483        if (options->set_default)
4484                options->set_default(options);
4485
4486        if (HAS_MULTI_BITS(options->output_format & check_mask))
4487                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4488
4489        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4490                die(_("-G, -S and --find-object are mutually exclusive"));
4491
4492        /*
4493         * Most of the time we can say "there are changes"
4494         * only by checking if there are changed paths, but
4495         * --ignore-whitespace* options force us to look
4496         * inside contents.
4497         */
4498
4499        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4500                options->flags.diff_from_contents = 1;
4501        else
4502                options->flags.diff_from_contents = 0;
4503
4504        if (options->flags.find_copies_harder)
4505                options->detect_rename = DIFF_DETECT_COPY;
4506
4507        if (!options->flags.relative_name)
4508                options->prefix = NULL;
4509        if (options->prefix)
4510                options->prefix_length = strlen(options->prefix);
4511        else
4512                options->prefix_length = 0;
4513
4514        if (options->output_format & (DIFF_FORMAT_NAME |
4515                                      DIFF_FORMAT_NAME_STATUS |
4516                                      DIFF_FORMAT_CHECKDIFF |
4517                                      DIFF_FORMAT_NO_OUTPUT))
4518                options->output_format &= ~(DIFF_FORMAT_RAW |
4519                                            DIFF_FORMAT_NUMSTAT |
4520                                            DIFF_FORMAT_DIFFSTAT |
4521                                            DIFF_FORMAT_SHORTSTAT |
4522                                            DIFF_FORMAT_DIRSTAT |
4523                                            DIFF_FORMAT_SUMMARY |
4524                                            DIFF_FORMAT_PATCH);
4525
4526        /*
4527         * These cases always need recursive; we do not drop caller-supplied
4528         * recursive bits for other formats here.
4529         */
4530        if (options->output_format & (DIFF_FORMAT_PATCH |
4531                                      DIFF_FORMAT_NUMSTAT |
4532                                      DIFF_FORMAT_DIFFSTAT |
4533                                      DIFF_FORMAT_SHORTSTAT |
4534                                      DIFF_FORMAT_DIRSTAT |
4535                                      DIFF_FORMAT_SUMMARY |
4536                                      DIFF_FORMAT_CHECKDIFF))
4537                options->flags.recursive = 1;
4538        /*
4539         * Also pickaxe would not work very well if you do not say recursive
4540         */
4541        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4542                options->flags.recursive = 1;
4543        /*
4544         * When patches are generated, submodules diffed against the work tree
4545         * must be checked for dirtiness too so it can be shown in the output
4546         */
4547        if (options->output_format & DIFF_FORMAT_PATCH)
4548                options->flags.dirty_submodules = 1;
4549
4550        if (options->detect_rename && options->rename_limit < 0)
4551                options->rename_limit = diff_rename_limit_default;
4552        if (hexsz < options->abbrev)
4553                options->abbrev = hexsz; /* full */
4554
4555        /*
4556         * It does not make sense to show the first hit we happened
4557         * to have found.  It does not make sense not to return with
4558         * exit code in such a case either.
4559         */
4560        if (options->flags.quick) {
4561                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4562                options->flags.exit_with_status = 1;
4563        }
4564
4565        options->diff_path_counter = 0;
4566
4567        if (options->flags.follow_renames && options->pathspec.nr != 1)
4568                die(_("--follow requires exactly one pathspec"));
4569
4570        if (!options->use_color || external_diff())
4571                options->color_moved = 0;
4572}
4573
4574static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4575{
4576        char c, *eq;
4577        int len;
4578
4579        if (*arg != '-')
4580                return 0;
4581        c = *++arg;
4582        if (!c)
4583                return 0;
4584        if (c == arg_short) {
4585                c = *++arg;
4586                if (!c)
4587                        return 1;
4588                if (val && isdigit(c)) {
4589                        char *end;
4590                        int n = strtoul(arg, &end, 10);
4591                        if (*end)
4592                                return 0;
4593                        *val = n;
4594                        return 1;
4595                }
4596                return 0;
4597        }
4598        if (c != '-')
4599                return 0;
4600        arg++;
4601        eq = strchrnul(arg, '=');
4602        len = eq - arg;
4603        if (!len || strncmp(arg, arg_long, len))
4604                return 0;
4605        if (*eq) {
4606                int n;
4607                char *end;
4608                if (!isdigit(*++eq))
4609                        return 0;
4610                n = strtoul(eq, &end, 10);
4611                if (*end)
4612                        return 0;
4613                *val = n;
4614        }
4615        return 1;
4616}
4617
4618static int diff_scoreopt_parse(const char *opt);
4619
4620static inline int short_opt(char opt, const char **argv,
4621                            const char **optarg)
4622{
4623        const char *arg = argv[0];
4624        if (arg[0] != '-' || arg[1] != opt)
4625                return 0;
4626        if (arg[2] != '\0') {
4627                *optarg = arg + 2;
4628                return 1;
4629        }
4630        if (!argv[1])
4631                die("Option '%c' requires a value", opt);
4632        *optarg = argv[1];
4633        return 2;
4634}
4635
4636int parse_long_opt(const char *opt, const char **argv,
4637                   const char **optarg)
4638{
4639        const char *arg = argv[0];
4640        if (!skip_prefix(arg, "--", &arg))
4641                return 0;
4642        if (!skip_prefix(arg, opt, &arg))
4643                return 0;
4644        if (*arg == '=') { /* stuck form: --option=value */
4645                *optarg = arg + 1;
4646                return 1;
4647        }
4648        if (*arg != '\0')
4649                return 0;
4650        /* separate form: --option value */
4651        if (!argv[1])
4652                die("Option '--%s' requires a value", opt);
4653        *optarg = argv[1];
4654        return 2;
4655}
4656
4657static int stat_opt(struct diff_options *options, const char **av)
4658{
4659        const char *arg = av[0];
4660        char *end;
4661        int width = options->stat_width;
4662        int name_width = options->stat_name_width;
4663        int graph_width = options->stat_graph_width;
4664        int count = options->stat_count;
4665        int argcount = 1;
4666
4667        if (!skip_prefix(arg, "--stat", &arg))
4668                BUG("stat option does not begin with --stat: %s", arg);
4669        end = (char *)arg;
4670
4671        switch (*arg) {
4672        case '-':
4673                if (skip_prefix(arg, "-width", &arg)) {
4674                        if (*arg == '=')
4675                                width = strtoul(arg + 1, &end, 10);
4676                        else if (!*arg && !av[1])
4677                                die_want_option("--stat-width");
4678                        else if (!*arg) {
4679                                width = strtoul(av[1], &end, 10);
4680                                argcount = 2;
4681                        }
4682                } else if (skip_prefix(arg, "-name-width", &arg)) {
4683                        if (*arg == '=')
4684                                name_width = strtoul(arg + 1, &end, 10);
4685                        else if (!*arg && !av[1])
4686                                die_want_option("--stat-name-width");
4687                        else if (!*arg) {
4688                                name_width = strtoul(av[1], &end, 10);
4689                                argcount = 2;
4690                        }
4691                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4692                        if (*arg == '=')
4693                                graph_width = strtoul(arg + 1, &end, 10);
4694                        else if (!*arg && !av[1])
4695                                die_want_option("--stat-graph-width");
4696                        else if (!*arg) {
4697                                graph_width = strtoul(av[1], &end, 10);
4698                                argcount = 2;
4699                        }
4700                } else if (skip_prefix(arg, "-count", &arg)) {
4701                        if (*arg == '=')
4702                                count = strtoul(arg + 1, &end, 10);
4703                        else if (!*arg && !av[1])
4704                                die_want_option("--stat-count");
4705                        else if (!*arg) {
4706                                count = strtoul(av[1], &end, 10);
4707                                argcount = 2;
4708                        }
4709                }
4710                break;
4711        case '=':
4712                width = strtoul(arg+1, &end, 10);
4713                if (*end == ',')
4714                        name_width = strtoul(end+1, &end, 10);
4715                if (*end == ',')
4716                        count = strtoul(end+1, &end, 10);
4717        }
4718
4719        /* Important! This checks all the error cases! */
4720        if (*end)
4721                return 0;
4722        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4723        options->stat_name_width = name_width;
4724        options->stat_graph_width = graph_width;
4725        options->stat_width = width;
4726        options->stat_count = count;
4727        return argcount;
4728}
4729
4730static int parse_dirstat_opt(struct diff_options *options, const char *params)
4731{
4732        struct strbuf errmsg = STRBUF_INIT;
4733        if (parse_dirstat_params(options, params, &errmsg))
4734                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4735                    errmsg.buf);
4736        strbuf_release(&errmsg);
4737        /*
4738         * The caller knows a dirstat-related option is given from the command
4739         * line; allow it to say "return this_function();"
4740         */
4741        options->output_format |= DIFF_FORMAT_DIRSTAT;
4742        return 1;
4743}
4744
4745static int parse_submodule_opt(struct diff_options *options, const char *value)
4746{
4747        if (parse_submodule_params(options, value))
4748                die(_("Failed to parse --submodule option parameter: '%s'"),
4749                        value);
4750        return 1;
4751}
4752
4753static const char diff_status_letters[] = {
4754        DIFF_STATUS_ADDED,
4755        DIFF_STATUS_COPIED,
4756        DIFF_STATUS_DELETED,
4757        DIFF_STATUS_MODIFIED,
4758        DIFF_STATUS_RENAMED,
4759        DIFF_STATUS_TYPE_CHANGED,
4760        DIFF_STATUS_UNKNOWN,
4761        DIFF_STATUS_UNMERGED,
4762        DIFF_STATUS_FILTER_AON,
4763        DIFF_STATUS_FILTER_BROKEN,
4764        '\0',
4765};
4766
4767static unsigned int filter_bit['Z' + 1];
4768
4769static void prepare_filter_bits(void)
4770{
4771        int i;
4772
4773        if (!filter_bit[DIFF_STATUS_ADDED]) {
4774                for (i = 0; diff_status_letters[i]; i++)
4775                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4776        }
4777}
4778
4779static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4780{
4781        return opt->filter & filter_bit[(int) status];
4782}
4783
4784static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4785{
4786        int i, optch;
4787
4788        prepare_filter_bits();
4789
4790        /*
4791         * If there is a negation e.g. 'd' in the input, and we haven't
4792         * initialized the filter field with another --diff-filter, start
4793         * from full set of bits, except for AON.
4794         */
4795        if (!opt->filter) {
4796                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4797                        if (optch < 'a' || 'z' < optch)
4798                                continue;
4799                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4800                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4801                        break;
4802                }
4803        }
4804
4805        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4806                unsigned int bit;
4807                int negate;
4808
4809                if ('a' <= optch && optch <= 'z') {
4810                        negate = 1;
4811                        optch = toupper(optch);
4812                } else {
4813                        negate = 0;
4814                }
4815
4816                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4817                if (!bit)
4818                        return optarg[i];
4819                if (negate)
4820                        opt->filter &= ~bit;
4821                else
4822                        opt->filter |= bit;
4823        }
4824        return 0;
4825}
4826
4827static void enable_patch_output(int *fmt)
4828{
4829        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4830        *fmt |= DIFF_FORMAT_PATCH;
4831}
4832
4833static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4834{
4835        int val = parse_ws_error_highlight(arg);
4836
4837        if (val < 0) {
4838                error("unknown value after ws-error-highlight=%.*s",
4839                      -1 - val, arg);
4840                return 0;
4841        }
4842        opt->ws_error_highlight = val;
4843        return 1;
4844}
4845
4846static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4847{
4848        struct object_id oid;
4849
4850        if (get_oid(arg, &oid))
4851                return error("unable to resolve '%s'", arg);
4852
4853        if (!opt->objfind)
4854                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4855
4856        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4857        opt->flags.recursive = 1;
4858        opt->flags.tree_in_recursive = 1;
4859        oidset_insert(opt->objfind, &oid);
4860        return 1;
4861}
4862
4863int diff_opt_parse(struct diff_options *options,
4864                   const char **av, int ac, const char *prefix)
4865{
4866        const char *arg = av[0];
4867        const char *optarg;
4868        int argcount;
4869
4870        if (!prefix)
4871                prefix = "";
4872
4873        /* Output format options */
4874        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4875            || opt_arg(arg, 'U', "unified", &options->context))
4876                enable_patch_output(&options->output_format);
4877        else if (!strcmp(arg, "--raw"))
4878                options->output_format |= DIFF_FORMAT_RAW;
4879        else if (!strcmp(arg, "--patch-with-raw")) {
4880                enable_patch_output(&options->output_format);
4881                options->output_format |= DIFF_FORMAT_RAW;
4882        } else if (!strcmp(arg, "--numstat"))
4883                options->output_format |= DIFF_FORMAT_NUMSTAT;
4884        else if (!strcmp(arg, "--shortstat"))
4885                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4886        else if (skip_prefix(arg, "-X", &arg) ||
4887                 skip_to_optional_arg(arg, "--dirstat", &arg))
4888                return parse_dirstat_opt(options, arg);
4889        else if (!strcmp(arg, "--cumulative"))
4890                return parse_dirstat_opt(options, "cumulative");
4891        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4892                parse_dirstat_opt(options, "files");
4893                return parse_dirstat_opt(options, arg);
4894        }
4895        else if (!strcmp(arg, "--check"))
4896                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4897        else if (!strcmp(arg, "--summary"))
4898                options->output_format |= DIFF_FORMAT_SUMMARY;
4899        else if (!strcmp(arg, "--patch-with-stat")) {
4900                enable_patch_output(&options->output_format);
4901                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4902        } else if (!strcmp(arg, "--name-only"))
4903                options->output_format |= DIFF_FORMAT_NAME;
4904        else if (!strcmp(arg, "--name-status"))
4905                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4906        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4907                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4908        else if (starts_with(arg, "--stat"))
4909                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4910                return stat_opt(options, av);
4911        else if (!strcmp(arg, "--compact-summary")) {
4912                 options->flags.stat_with_summary = 1;
4913                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4914        } else if (!strcmp(arg, "--no-compact-summary"))
4915                 options->flags.stat_with_summary = 0;
4916        else if (skip_prefix(arg, "--output-indicator-new=", &arg))
4917                options->output_indicators[OUTPUT_INDICATOR_NEW] = arg[0];
4918        else if (skip_prefix(arg, "--output-indicator-old=", &arg))
4919                options->output_indicators[OUTPUT_INDICATOR_OLD] = arg[0];
4920        else if (skip_prefix(arg, "--output-indicator-context=", &arg))
4921                options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = arg[0];
4922
4923        /* renames options */
4924        else if (starts_with(arg, "-B") ||
4925                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
4926                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4927                        return error("invalid argument to -B: %s", arg+2);
4928        }
4929        else if (starts_with(arg, "-M") ||
4930                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
4931                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4932                        return error("invalid argument to -M: %s", arg+2);
4933                options->detect_rename = DIFF_DETECT_RENAME;
4934        }
4935        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4936                options->irreversible_delete = 1;
4937        }
4938        else if (starts_with(arg, "-C") ||
4939                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
4940                if (options->detect_rename == DIFF_DETECT_COPY)
4941                        options->flags.find_copies_harder = 1;
4942                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4943                        return error("invalid argument to -C: %s", arg+2);
4944                options->detect_rename = DIFF_DETECT_COPY;
4945        }
4946        else if (!strcmp(arg, "--no-renames"))
4947                options->detect_rename = 0;
4948        else if (!strcmp(arg, "--rename-empty"))
4949                options->flags.rename_empty = 1;
4950        else if (!strcmp(arg, "--no-rename-empty"))
4951                options->flags.rename_empty = 0;
4952        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
4953                options->flags.relative_name = 1;
4954                if (arg)
4955                        options->prefix = arg;
4956        }
4957
4958        /* xdiff options */
4959        else if (!strcmp(arg, "--minimal"))
4960                DIFF_XDL_SET(options, NEED_MINIMAL);
4961        else if (!strcmp(arg, "--no-minimal"))
4962                DIFF_XDL_CLR(options, NEED_MINIMAL);
4963        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4964                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4965        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4966                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4967        else if (!strcmp(arg, "--ignore-space-at-eol"))
4968                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4969        else if (!strcmp(arg, "--ignore-cr-at-eol"))
4970                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
4971        else if (!strcmp(arg, "--ignore-blank-lines"))
4972                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4973        else if (!strcmp(arg, "--indent-heuristic"))
4974                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4975        else if (!strcmp(arg, "--no-indent-heuristic"))
4976                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4977        else if (!strcmp(arg, "--patience")) {
4978                int i;
4979                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4980                /*
4981                 * Both --patience and --anchored use PATIENCE_DIFF
4982                 * internally, so remove any anchors previously
4983                 * specified.
4984                 */
4985                for (i = 0; i < options->anchors_nr; i++)
4986                        free(options->anchors[i]);
4987                options->anchors_nr = 0;
4988        } else if (!strcmp(arg, "--histogram"))
4989                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4990        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4991                long value = parse_algorithm_value(optarg);
4992                if (value < 0)
4993                        return error("option diff-algorithm accepts \"myers\", "
4994                                     "\"minimal\", \"patience\" and \"histogram\"");
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 argcount;
5000        } else if (skip_prefix(arg, "--anchored=", &arg)) {
5001                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
5002                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
5003                           options->anchors_alloc);
5004                options->anchors[options->anchors_nr++] = xstrdup(arg);
5005        }
5006
5007        /* flags options */
5008        else if (!strcmp(arg, "--binary")) {
5009                enable_patch_output(&options->output_format);
5010                options->flags.binary = 1;
5011        }
5012        else if (!strcmp(arg, "--full-index"))
5013                options->flags.full_index = 1;
5014        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
5015                options->flags.text = 1;
5016        else if (!strcmp(arg, "-R"))
5017                options->flags.reverse_diff = 1;
5018        else if (!strcmp(arg, "--find-copies-harder"))
5019                options->flags.find_copies_harder = 1;
5020        else if (!strcmp(arg, "--follow"))
5021                options->flags.follow_renames = 1;
5022        else if (!strcmp(arg, "--no-follow")) {
5023                options->flags.follow_renames = 0;
5024                options->flags.default_follow_renames = 0;
5025        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
5026                int value = git_config_colorbool(NULL, arg);
5027                if (value < 0)
5028                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
5029                options->use_color = value;
5030        }
5031        else if (!strcmp(arg, "--no-color"))
5032                options->use_color = 0;
5033        else if (!strcmp(arg, "--color-moved")) {
5034                if (diff_color_moved_default)
5035                        options->color_moved = diff_color_moved_default;
5036                if (options->color_moved == COLOR_MOVED_NO)
5037                        options->color_moved = COLOR_MOVED_DEFAULT;
5038        } else if (!strcmp(arg, "--no-color-moved"))
5039                options->color_moved = COLOR_MOVED_NO;
5040        else if (skip_prefix(arg, "--color-moved=", &arg)) {
5041                int cm = parse_color_moved(arg);
5042                if (cm < 0)
5043                        return error("bad --color-moved argument: %s", arg);
5044                options->color_moved = cm;
5045        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
5046                unsigned cm = parse_color_moved_ws(arg);
5047                if (cm & COLOR_MOVED_WS_ERROR)
5048                        return -1;
5049                options->color_moved_ws_handling = cm;
5050        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
5051                options->use_color = 1;
5052                options->word_diff = DIFF_WORDS_COLOR;
5053        }
5054        else if (!strcmp(arg, "--word-diff")) {
5055                if (options->word_diff == DIFF_WORDS_NONE)
5056                        options->word_diff = DIFF_WORDS_PLAIN;
5057        }
5058        else if (skip_prefix(arg, "--word-diff=", &arg)) {
5059                if (!strcmp(arg, "plain"))
5060                        options->word_diff = DIFF_WORDS_PLAIN;
5061                else if (!strcmp(arg, "color")) {
5062                        options->use_color = 1;
5063                        options->word_diff = DIFF_WORDS_COLOR;
5064                }
5065                else if (!strcmp(arg, "porcelain"))
5066                        options->word_diff = DIFF_WORDS_PORCELAIN;
5067                else if (!strcmp(arg, "none"))
5068                        options->word_diff = DIFF_WORDS_NONE;
5069                else
5070                        die("bad --word-diff argument: %s", arg);
5071        }
5072        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
5073                if (options->word_diff == DIFF_WORDS_NONE)
5074                        options->word_diff = DIFF_WORDS_PLAIN;
5075                options->word_regex = optarg;
5076                return argcount;
5077        }
5078        else if (!strcmp(arg, "--exit-code"))
5079                options->flags.exit_with_status = 1;
5080        else if (!strcmp(arg, "--quiet"))
5081                options->flags.quick = 1;
5082        else if (!strcmp(arg, "--ext-diff"))
5083                options->flags.allow_external = 1;
5084        else if (!strcmp(arg, "--no-ext-diff"))
5085                options->flags.allow_external = 0;
5086        else if (!strcmp(arg, "--textconv")) {
5087                options->flags.allow_textconv = 1;
5088                options->flags.textconv_set_via_cmdline = 1;
5089        } else if (!strcmp(arg, "--no-textconv"))
5090                options->flags.allow_textconv = 0;
5091        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
5092                options->flags.override_submodule_config = 1;
5093                handle_ignore_submodules_arg(options, arg);
5094        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
5095                return parse_submodule_opt(options, arg);
5096        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
5097                return parse_ws_error_highlight_opt(options, arg);
5098        else if (!strcmp(arg, "--ita-invisible-in-index"))
5099                options->ita_invisible_in_index = 1;
5100        else if (!strcmp(arg, "--ita-visible-in-index"))
5101                options->ita_invisible_in_index = 0;
5102
5103        /* misc options */
5104        else if (!strcmp(arg, "-z"))
5105                options->line_termination = 0;
5106        else if ((argcount = short_opt('l', av, &optarg))) {
5107                options->rename_limit = strtoul(optarg, NULL, 10);
5108                return argcount;
5109        }
5110        else if ((argcount = short_opt('S', av, &optarg))) {
5111                options->pickaxe = optarg;
5112                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
5113                return argcount;
5114        } else if ((argcount = short_opt('G', av, &optarg))) {
5115                options->pickaxe = optarg;
5116                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
5117                return argcount;
5118        }
5119        else if (!strcmp(arg, "--pickaxe-all"))
5120                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
5121        else if (!strcmp(arg, "--pickaxe-regex"))
5122                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
5123        else if ((argcount = short_opt('O', av, &optarg))) {
5124                options->orderfile = prefix_filename(prefix, optarg);
5125                return argcount;
5126        } else if (skip_prefix(arg, "--find-object=", &arg))
5127                return parse_objfind_opt(options, arg);
5128        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
5129                int offending = parse_diff_filter_opt(optarg, options);
5130                if (offending)
5131                        die("unknown change class '%c' in --diff-filter=%s",
5132                            offending, optarg);
5133                return argcount;
5134        }
5135        else if (!strcmp(arg, "--no-abbrev"))
5136                options->abbrev = 0;
5137        else if (!strcmp(arg, "--abbrev"))
5138                options->abbrev = DEFAULT_ABBREV;
5139        else if (skip_prefix(arg, "--abbrev=", &arg)) {
5140                options->abbrev = strtoul(arg, NULL, 10);
5141                if (options->abbrev < MINIMUM_ABBREV)
5142                        options->abbrev = MINIMUM_ABBREV;
5143                else if (the_hash_algo->hexsz < options->abbrev)
5144                        options->abbrev = the_hash_algo->hexsz;
5145        }
5146        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5147                options->a_prefix = optarg;
5148                return argcount;
5149        }
5150        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5151                options->line_prefix = optarg;
5152                options->line_prefix_length = strlen(options->line_prefix);
5153                graph_setup_line_prefix(options);
5154                return argcount;
5155        }
5156        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5157                options->b_prefix = optarg;
5158                return argcount;
5159        }
5160        else if (!strcmp(arg, "--no-prefix"))
5161                options->a_prefix = options->b_prefix = "";
5162        else if (opt_arg(arg, '\0', "inter-hunk-context",
5163                         &options->interhunkcontext))
5164                ;
5165        else if (!strcmp(arg, "-W"))
5166                options->flags.funccontext = 1;
5167        else if (!strcmp(arg, "--function-context"))
5168                options->flags.funccontext = 1;
5169        else if (!strcmp(arg, "--no-function-context"))
5170                options->flags.funccontext = 0;
5171        else if ((argcount = parse_long_opt("output", av, &optarg))) {
5172                char *path = prefix_filename(prefix, optarg);
5173                options->file = xfopen(path, "w");
5174                options->close_file = 1;
5175                if (options->use_color != GIT_COLOR_ALWAYS)
5176                        options->use_color = GIT_COLOR_NEVER;
5177                free(path);
5178                return argcount;
5179        } else
5180                return 0;
5181        return 1;
5182}
5183
5184int parse_rename_score(const char **cp_p)
5185{
5186        unsigned long num, scale;
5187        int ch, dot;
5188        const char *cp = *cp_p;
5189
5190        num = 0;
5191        scale = 1;
5192        dot = 0;
5193        for (;;) {
5194                ch = *cp;
5195                if ( !dot && ch == '.' ) {
5196                        scale = 1;
5197                        dot = 1;
5198                } else if ( ch == '%' ) {
5199                        scale = dot ? scale*100 : 100;
5200                        cp++;   /* % is always at the end */
5201                        break;
5202                } else if ( ch >= '0' && ch <= '9' ) {
5203                        if ( scale < 100000 ) {
5204                                scale *= 10;
5205                                num = (num*10) + (ch-'0');
5206                        }
5207                } else {
5208                        break;
5209                }
5210                cp++;
5211        }
5212        *cp_p = cp;
5213
5214        /* user says num divided by scale and we say internally that
5215         * is MAX_SCORE * num / scale.
5216         */
5217        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5218}
5219
5220static int diff_scoreopt_parse(const char *opt)
5221{
5222        int opt1, opt2, cmd;
5223
5224        if (*opt++ != '-')
5225                return -1;
5226        cmd = *opt++;
5227        if (cmd == '-') {
5228                /* convert the long-form arguments into short-form versions */
5229                if (skip_prefix(opt, "break-rewrites", &opt)) {
5230                        if (*opt == 0 || *opt++ == '=')
5231                                cmd = 'B';
5232                } else if (skip_prefix(opt, "find-copies", &opt)) {
5233                        if (*opt == 0 || *opt++ == '=')
5234                                cmd = 'C';
5235                } else if (skip_prefix(opt, "find-renames", &opt)) {
5236                        if (*opt == 0 || *opt++ == '=')
5237                                cmd = 'M';
5238                }
5239        }
5240        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
5241                return -1; /* that is not a -M, -C, or -B option */
5242
5243        opt1 = parse_rename_score(&opt);
5244        if (cmd != 'B')
5245                opt2 = 0;
5246        else {
5247                if (*opt == 0)
5248                        opt2 = 0;
5249                else if (*opt != '/')
5250                        return -1; /* we expect -B80/99 or -B80 */
5251                else {
5252                        opt++;
5253                        opt2 = parse_rename_score(&opt);
5254                }
5255        }
5256        if (*opt != 0)
5257                return -1;
5258        return opt1 | (opt2 << 16);
5259}
5260
5261struct diff_queue_struct diff_queued_diff;
5262
5263void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5264{
5265        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5266        queue->queue[queue->nr++] = dp;
5267}
5268
5269struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5270                                 struct diff_filespec *one,
5271                                 struct diff_filespec *two)
5272{
5273        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5274        dp->one = one;
5275        dp->two = two;
5276        if (queue)
5277                diff_q(queue, dp);
5278        return dp;
5279}
5280
5281void diff_free_filepair(struct diff_filepair *p)
5282{
5283        free_filespec(p->one);
5284        free_filespec(p->two);
5285        free(p);
5286}
5287
5288const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5289{
5290        int abblen;
5291        const char *abbrev;
5292
5293        /* Do we want all 40 hex characters? */
5294        if (len == the_hash_algo->hexsz)
5295                return oid_to_hex(oid);
5296
5297        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5298        abbrev = diff_abbrev_oid(oid, len);
5299
5300        if (!print_sha1_ellipsis())
5301                return abbrev;
5302
5303        abblen = strlen(abbrev);
5304
5305        /*
5306         * In well-behaved cases, where the abbreviated result is the
5307         * same as the requested length, append three dots after the
5308         * abbreviation (hence the whole logic is limited to the case
5309         * where abblen < 37); when the actual abbreviated result is a
5310         * bit longer than the requested length, we reduce the number
5311         * of dots so that they match the well-behaved ones.  However,
5312         * if the actual abbreviation is longer than the requested
5313         * length by more than three, we give up on aligning, and add
5314         * three dots anyway, to indicate that the output is not the
5315         * full object name.  Yes, this may be suboptimal, but this
5316         * appears only in "diff --raw --abbrev" output and it is not
5317         * worth the effort to change it now.  Note that this would
5318         * likely to work fine when the automatic sizing of default
5319         * abbreviation length is used--we would be fed -1 in "len" in
5320         * that case, and will end up always appending three-dots, but
5321         * the automatic sizing is supposed to give abblen that ensures
5322         * uniqueness across all objects (statistically speaking).
5323         */
5324        if (abblen < the_hash_algo->hexsz - 3) {
5325                static char hex[GIT_MAX_HEXSZ + 1];
5326                if (len < abblen && abblen <= len + 2)
5327                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5328                else
5329                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5330                return hex;
5331        }
5332
5333        return oid_to_hex(oid);
5334}
5335
5336static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5337{
5338        int line_termination = opt->line_termination;
5339        int inter_name_termination = line_termination ? '\t' : '\0';
5340
5341        fprintf(opt->file, "%s", diff_line_prefix(opt));
5342        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5343                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5344                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5345                fprintf(opt->file, "%s ",
5346                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5347        }
5348        if (p->score) {
5349                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5350                        inter_name_termination);
5351        } else {
5352                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5353        }
5354
5355        if (p->status == DIFF_STATUS_COPIED ||
5356            p->status == DIFF_STATUS_RENAMED) {
5357                const char *name_a, *name_b;
5358                name_a = p->one->path;
5359                name_b = p->two->path;
5360                strip_prefix(opt->prefix_length, &name_a, &name_b);
5361                write_name_quoted(name_a, opt->file, inter_name_termination);
5362                write_name_quoted(name_b, opt->file, line_termination);
5363        } else {
5364                const char *name_a, *name_b;
5365                name_a = p->one->mode ? p->one->path : p->two->path;
5366                name_b = NULL;
5367                strip_prefix(opt->prefix_length, &name_a, &name_b);
5368                write_name_quoted(name_a, opt->file, line_termination);
5369        }
5370}
5371
5372int diff_unmodified_pair(struct diff_filepair *p)
5373{
5374        /* This function is written stricter than necessary to support
5375         * the currently implemented transformers, but the idea is to
5376         * let transformers to produce diff_filepairs any way they want,
5377         * and filter and clean them up here before producing the output.
5378         */
5379        struct diff_filespec *one = p->one, *two = p->two;
5380
5381        if (DIFF_PAIR_UNMERGED(p))
5382                return 0; /* unmerged is interesting */
5383
5384        /* deletion, addition, mode or type change
5385         * and rename are all interesting.
5386         */
5387        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5388            DIFF_PAIR_MODE_CHANGED(p) ||
5389            strcmp(one->path, two->path))
5390                return 0;
5391
5392        /* both are valid and point at the same path.  that is, we are
5393         * dealing with a change.
5394         */
5395        if (one->oid_valid && two->oid_valid &&
5396            oideq(&one->oid, &two->oid) &&
5397            !one->dirty_submodule && !two->dirty_submodule)
5398                return 1; /* no change */
5399        if (!one->oid_valid && !two->oid_valid)
5400                return 1; /* both look at the same file on the filesystem. */
5401        return 0;
5402}
5403
5404static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5405{
5406        if (diff_unmodified_pair(p))
5407                return;
5408
5409        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5410            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5411                return; /* no tree diffs in patch format */
5412
5413        run_diff(p, o);
5414}
5415
5416static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5417                            struct diffstat_t *diffstat)
5418{
5419        if (diff_unmodified_pair(p))
5420                return;
5421
5422        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5423            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5424                return; /* no useful stat for tree diffs */
5425
5426        run_diffstat(p, o, diffstat);
5427}
5428
5429static void diff_flush_checkdiff(struct diff_filepair *p,
5430                struct diff_options *o)
5431{
5432        if (diff_unmodified_pair(p))
5433                return;
5434
5435        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5436            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5437                return; /* nothing to check in tree diffs */
5438
5439        run_checkdiff(p, o);
5440}
5441
5442int diff_queue_is_empty(void)
5443{
5444        struct diff_queue_struct *q = &diff_queued_diff;
5445        int i;
5446        for (i = 0; i < q->nr; i++)
5447                if (!diff_unmodified_pair(q->queue[i]))
5448                        return 0;
5449        return 1;
5450}
5451
5452#if DIFF_DEBUG
5453void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5454{
5455        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5456                x, one ? one : "",
5457                s->path,
5458                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5459                s->mode,
5460                s->oid_valid ? oid_to_hex(&s->oid) : "");
5461        fprintf(stderr, "queue[%d] %s size %lu\n",
5462                x, one ? one : "",
5463                s->size);
5464}
5465
5466void diff_debug_filepair(const struct diff_filepair *p, int i)
5467{
5468        diff_debug_filespec(p->one, i, "one");
5469        diff_debug_filespec(p->two, i, "two");
5470        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5471                p->score, p->status ? p->status : '?',
5472                p->one->rename_used, p->broken_pair);
5473}
5474
5475void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5476{
5477        int i;
5478        if (msg)
5479                fprintf(stderr, "%s\n", msg);
5480        fprintf(stderr, "q->nr = %d\n", q->nr);
5481        for (i = 0; i < q->nr; i++) {
5482                struct diff_filepair *p = q->queue[i];
5483                diff_debug_filepair(p, i);
5484        }
5485}
5486#endif
5487
5488static void diff_resolve_rename_copy(void)
5489{
5490        int i;
5491        struct diff_filepair *p;
5492        struct diff_queue_struct *q = &diff_queued_diff;
5493
5494        diff_debug_queue("resolve-rename-copy", q);
5495
5496        for (i = 0; i < q->nr; i++) {
5497                p = q->queue[i];
5498                p->status = 0; /* undecided */
5499                if (DIFF_PAIR_UNMERGED(p))
5500                        p->status = DIFF_STATUS_UNMERGED;
5501                else if (!DIFF_FILE_VALID(p->one))
5502                        p->status = DIFF_STATUS_ADDED;
5503                else if (!DIFF_FILE_VALID(p->two))
5504                        p->status = DIFF_STATUS_DELETED;
5505                else if (DIFF_PAIR_TYPE_CHANGED(p))
5506                        p->status = DIFF_STATUS_TYPE_CHANGED;
5507
5508                /* from this point on, we are dealing with a pair
5509                 * whose both sides are valid and of the same type, i.e.
5510                 * either in-place edit or rename/copy edit.
5511                 */
5512                else if (DIFF_PAIR_RENAME(p)) {
5513                        /*
5514                         * A rename might have re-connected a broken
5515                         * pair up, causing the pathnames to be the
5516                         * same again. If so, that's not a rename at
5517                         * all, just a modification..
5518                         *
5519                         * Otherwise, see if this source was used for
5520                         * multiple renames, in which case we decrement
5521                         * the count, and call it a copy.
5522                         */
5523                        if (!strcmp(p->one->path, p->two->path))
5524                                p->status = DIFF_STATUS_MODIFIED;
5525                        else if (--p->one->rename_used > 0)
5526                                p->status = DIFF_STATUS_COPIED;
5527                        else
5528                                p->status = DIFF_STATUS_RENAMED;
5529                }
5530                else if (!oideq(&p->one->oid, &p->two->oid) ||
5531                         p->one->mode != p->two->mode ||
5532                         p->one->dirty_submodule ||
5533                         p->two->dirty_submodule ||
5534                         is_null_oid(&p->one->oid))
5535                        p->status = DIFF_STATUS_MODIFIED;
5536                else {
5537                        /* This is a "no-change" entry and should not
5538                         * happen anymore, but prepare for broken callers.
5539                         */
5540                        error("feeding unmodified %s to diffcore",
5541                              p->one->path);
5542                        p->status = DIFF_STATUS_UNKNOWN;
5543                }
5544        }
5545        diff_debug_queue("resolve-rename-copy done", q);
5546}
5547
5548static int check_pair_status(struct diff_filepair *p)
5549{
5550        switch (p->status) {
5551        case DIFF_STATUS_UNKNOWN:
5552                return 0;
5553        case 0:
5554                die("internal error in diff-resolve-rename-copy");
5555        default:
5556                return 1;
5557        }
5558}
5559
5560static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5561{
5562        int fmt = opt->output_format;
5563
5564        if (fmt & DIFF_FORMAT_CHECKDIFF)
5565                diff_flush_checkdiff(p, opt);
5566        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5567                diff_flush_raw(p, opt);
5568        else if (fmt & DIFF_FORMAT_NAME) {
5569                const char *name_a, *name_b;
5570                name_a = p->two->path;
5571                name_b = NULL;
5572                strip_prefix(opt->prefix_length, &name_a, &name_b);
5573                fprintf(opt->file, "%s", diff_line_prefix(opt));
5574                write_name_quoted(name_a, opt->file, opt->line_termination);
5575        }
5576}
5577
5578static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5579{
5580        struct strbuf sb = STRBUF_INIT;
5581        if (fs->mode)
5582                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5583        else
5584                strbuf_addf(&sb, " %s ", newdelete);
5585
5586        quote_c_style(fs->path, &sb, NULL, 0);
5587        strbuf_addch(&sb, '\n');
5588        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5589                         sb.buf, sb.len, 0);
5590        strbuf_release(&sb);
5591}
5592
5593static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5594                int show_name)
5595{
5596        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5597                struct strbuf sb = STRBUF_INIT;
5598                strbuf_addf(&sb, " mode change %06o => %06o",
5599                            p->one->mode, p->two->mode);
5600                if (show_name) {
5601                        strbuf_addch(&sb, ' ');
5602                        quote_c_style(p->two->path, &sb, NULL, 0);
5603                }
5604                strbuf_addch(&sb, '\n');
5605                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5606                                 sb.buf, sb.len, 0);
5607                strbuf_release(&sb);
5608        }
5609}
5610
5611static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5612                struct diff_filepair *p)
5613{
5614        struct strbuf sb = STRBUF_INIT;
5615        struct strbuf names = STRBUF_INIT;
5616
5617        pprint_rename(&names, p->one->path, p->two->path);
5618        strbuf_addf(&sb, " %s %s (%d%%)\n",
5619                    renamecopy, names.buf, similarity_index(p));
5620        strbuf_release(&names);
5621        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5622                                 sb.buf, sb.len, 0);
5623        show_mode_change(opt, p, 0);
5624        strbuf_release(&sb);
5625}
5626
5627static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5628{
5629        switch(p->status) {
5630        case DIFF_STATUS_DELETED:
5631                show_file_mode_name(opt, "delete", p->one);
5632                break;
5633        case DIFF_STATUS_ADDED:
5634                show_file_mode_name(opt, "create", p->two);
5635                break;
5636        case DIFF_STATUS_COPIED:
5637                show_rename_copy(opt, "copy", p);
5638                break;
5639        case DIFF_STATUS_RENAMED:
5640                show_rename_copy(opt, "rename", p);
5641                break;
5642        default:
5643                if (p->score) {
5644                        struct strbuf sb = STRBUF_INIT;
5645                        strbuf_addstr(&sb, " rewrite ");
5646                        quote_c_style(p->two->path, &sb, NULL, 0);
5647                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5648                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5649                                         sb.buf, sb.len, 0);
5650                        strbuf_release(&sb);
5651                }
5652                show_mode_change(opt, p, !p->score);
5653                break;
5654        }
5655}
5656
5657struct patch_id_t {
5658        git_SHA_CTX *ctx;
5659        int patchlen;
5660};
5661
5662static int remove_space(char *line, int len)
5663{
5664        int i;
5665        char *dst = line;
5666        unsigned char c;
5667
5668        for (i = 0; i < len; i++)
5669                if (!isspace((c = line[i])))
5670                        *dst++ = c;
5671
5672        return dst - line;
5673}
5674
5675static void patch_id_consume(void *priv, char *line, unsigned long len)
5676{
5677        struct patch_id_t *data = priv;
5678        int new_len;
5679
5680        new_len = remove_space(line, len);
5681
5682        git_SHA1_Update(data->ctx, line, new_len);
5683        data->patchlen += new_len;
5684}
5685
5686static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5687{
5688        git_SHA1_Update(ctx, str, strlen(str));
5689}
5690
5691static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5692{
5693        /* large enough for 2^32 in octal */
5694        char buf[12];
5695        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5696        git_SHA1_Update(ctx, buf, len);
5697}
5698
5699/* returns 0 upon success, and writes result into sha1 */
5700static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5701{
5702        struct diff_queue_struct *q = &diff_queued_diff;
5703        int i;
5704        git_SHA_CTX ctx;
5705        struct patch_id_t data;
5706
5707        git_SHA1_Init(&ctx);
5708        memset(&data, 0, sizeof(struct patch_id_t));
5709        data.ctx = &ctx;
5710
5711        for (i = 0; i < q->nr; i++) {
5712                xpparam_t xpp;
5713                xdemitconf_t xecfg;
5714                mmfile_t mf1, mf2;
5715                struct diff_filepair *p = q->queue[i];
5716                int len1, len2;
5717
5718                memset(&xpp, 0, sizeof(xpp));
5719                memset(&xecfg, 0, sizeof(xecfg));
5720                if (p->status == 0)
5721                        return error("internal diff status error");
5722                if (p->status == DIFF_STATUS_UNKNOWN)
5723                        continue;
5724                if (diff_unmodified_pair(p))
5725                        continue;
5726                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5727                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5728                        continue;
5729                if (DIFF_PAIR_UNMERGED(p))
5730                        continue;
5731
5732                diff_fill_oid_info(p->one, options->repo->index);
5733                diff_fill_oid_info(p->two, options->repo->index);
5734
5735                len1 = remove_space(p->one->path, strlen(p->one->path));
5736                len2 = remove_space(p->two->path, strlen(p->two->path));
5737                patch_id_add_string(&ctx, "diff--git");
5738                patch_id_add_string(&ctx, "a/");
5739                git_SHA1_Update(&ctx, p->one->path, len1);
5740                patch_id_add_string(&ctx, "b/");
5741                git_SHA1_Update(&ctx, p->two->path, len2);
5742
5743                if (p->one->mode == 0) {
5744                        patch_id_add_string(&ctx, "newfilemode");
5745                        patch_id_add_mode(&ctx, p->two->mode);
5746                        patch_id_add_string(&ctx, "---/dev/null");
5747                        patch_id_add_string(&ctx, "+++b/");
5748                        git_SHA1_Update(&ctx, p->two->path, len2);
5749                } else if (p->two->mode == 0) {
5750                        patch_id_add_string(&ctx, "deletedfilemode");
5751                        patch_id_add_mode(&ctx, p->one->mode);
5752                        patch_id_add_string(&ctx, "---a/");
5753                        git_SHA1_Update(&ctx, p->one->path, len1);
5754                        patch_id_add_string(&ctx, "+++/dev/null");
5755                } else {
5756                        patch_id_add_string(&ctx, "---a/");
5757                        git_SHA1_Update(&ctx, p->one->path, len1);
5758                        patch_id_add_string(&ctx, "+++b/");
5759                        git_SHA1_Update(&ctx, p->two->path, len2);
5760                }
5761
5762                if (diff_header_only)
5763                        continue;
5764
5765                if (fill_mmfile(options->repo, &mf1, p->one) < 0 ||
5766                    fill_mmfile(options->repo, &mf2, p->two) < 0)
5767                        return error("unable to read files to diff");
5768
5769                if (diff_filespec_is_binary(options->repo, p->one) ||
5770                    diff_filespec_is_binary(options->repo, p->two)) {
5771                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5772                                        GIT_SHA1_HEXSZ);
5773                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5774                                        GIT_SHA1_HEXSZ);
5775                        continue;
5776                }
5777
5778                xpp.flags = 0;
5779                xecfg.ctxlen = 3;
5780                xecfg.flags = 0;
5781                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
5782                                  patch_id_consume, &data, &xpp, &xecfg))
5783                        return error("unable to generate patch-id diff for %s",
5784                                     p->one->path);
5785        }
5786
5787        git_SHA1_Final(oid->hash, &ctx);
5788        return 0;
5789}
5790
5791int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5792{
5793        struct diff_queue_struct *q = &diff_queued_diff;
5794        int i;
5795        int result = diff_get_patch_id(options, oid, diff_header_only);
5796
5797        for (i = 0; i < q->nr; i++)
5798                diff_free_filepair(q->queue[i]);
5799
5800        free(q->queue);
5801        DIFF_QUEUE_CLEAR(q);
5802
5803        return result;
5804}
5805
5806static int is_summary_empty(const struct diff_queue_struct *q)
5807{
5808        int i;
5809
5810        for (i = 0; i < q->nr; i++) {
5811                const struct diff_filepair *p = q->queue[i];
5812
5813                switch (p->status) {
5814                case DIFF_STATUS_DELETED:
5815                case DIFF_STATUS_ADDED:
5816                case DIFF_STATUS_COPIED:
5817                case DIFF_STATUS_RENAMED:
5818                        return 0;
5819                default:
5820                        if (p->score)
5821                                return 0;
5822                        if (p->one->mode && p->two->mode &&
5823                            p->one->mode != p->two->mode)
5824                                return 0;
5825                        break;
5826                }
5827        }
5828        return 1;
5829}
5830
5831static const char rename_limit_warning[] =
5832N_("inexact rename detection was skipped due to too many files.");
5833
5834static const char degrade_cc_to_c_warning[] =
5835N_("only found copies from modified paths due to too many files.");
5836
5837static const char rename_limit_advice[] =
5838N_("you may want to set your %s variable to at least "
5839   "%d and retry the command.");
5840
5841void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5842{
5843        fflush(stdout);
5844        if (degraded_cc)
5845                warning(_(degrade_cc_to_c_warning));
5846        else if (needed)
5847                warning(_(rename_limit_warning));
5848        else
5849                return;
5850        if (0 < needed)
5851                warning(_(rename_limit_advice), varname, needed);
5852}
5853
5854static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5855{
5856        int i;
5857        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5858        struct diff_queue_struct *q = &diff_queued_diff;
5859
5860        if (WSEH_NEW & WS_RULE_MASK)
5861                BUG("WS rules bit mask overlaps with diff symbol flags");
5862
5863        if (o->color_moved)
5864                o->emitted_symbols = &esm;
5865
5866        for (i = 0; i < q->nr; i++) {
5867                struct diff_filepair *p = q->queue[i];
5868                if (check_pair_status(p))
5869                        diff_flush_patch(p, o);
5870        }
5871
5872        if (o->emitted_symbols) {
5873                if (o->color_moved) {
5874                        struct hashmap add_lines, del_lines;
5875
5876                        if (o->color_moved_ws_handling &
5877                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
5878                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
5879
5880                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
5881                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
5882
5883                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5884                        mark_color_as_moved(o, &add_lines, &del_lines);
5885                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5886                                dim_moved_lines(o);
5887
5888                        hashmap_free(&add_lines, 1);
5889                        hashmap_free(&del_lines, 1);
5890                }
5891
5892                for (i = 0; i < esm.nr; i++)
5893                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5894
5895                for (i = 0; i < esm.nr; i++)
5896                        free((void *)esm.buf[i].line);
5897        }
5898        esm.nr = 0;
5899}
5900
5901void diff_flush(struct diff_options *options)
5902{
5903        struct diff_queue_struct *q = &diff_queued_diff;
5904        int i, output_format = options->output_format;
5905        int separator = 0;
5906        int dirstat_by_line = 0;
5907
5908        /*
5909         * Order: raw, stat, summary, patch
5910         * or:    name/name-status/checkdiff (other bits clear)
5911         */
5912        if (!q->nr)
5913                goto free_queue;
5914
5915        if (output_format & (DIFF_FORMAT_RAW |
5916                             DIFF_FORMAT_NAME |
5917                             DIFF_FORMAT_NAME_STATUS |
5918                             DIFF_FORMAT_CHECKDIFF)) {
5919                for (i = 0; i < q->nr; i++) {
5920                        struct diff_filepair *p = q->queue[i];
5921                        if (check_pair_status(p))
5922                                flush_one_pair(p, options);
5923                }
5924                separator++;
5925        }
5926
5927        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5928                dirstat_by_line = 1;
5929
5930        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5931            dirstat_by_line) {
5932                struct diffstat_t diffstat;
5933
5934                memset(&diffstat, 0, sizeof(struct diffstat_t));
5935                for (i = 0; i < q->nr; i++) {
5936                        struct diff_filepair *p = q->queue[i];
5937                        if (check_pair_status(p))
5938                                diff_flush_stat(p, options, &diffstat);
5939                }
5940                if (output_format & DIFF_FORMAT_NUMSTAT)
5941                        show_numstat(&diffstat, options);
5942                if (output_format & DIFF_FORMAT_DIFFSTAT)
5943                        show_stats(&diffstat, options);
5944                if (output_format & DIFF_FORMAT_SHORTSTAT)
5945                        show_shortstats(&diffstat, options);
5946                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5947                        show_dirstat_by_line(&diffstat, options);
5948                free_diffstat_info(&diffstat);
5949                separator++;
5950        }
5951        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5952                show_dirstat(options);
5953
5954        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5955                for (i = 0; i < q->nr; i++) {
5956                        diff_summary(options, q->queue[i]);
5957                }
5958                separator++;
5959        }
5960
5961        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5962            options->flags.exit_with_status &&
5963            options->flags.diff_from_contents) {
5964                /*
5965                 * run diff_flush_patch for the exit status. setting
5966                 * options->file to /dev/null should be safe, because we
5967                 * aren't supposed to produce any output anyway.
5968                 */
5969                if (options->close_file)
5970                        fclose(options->file);
5971                options->file = xfopen("/dev/null", "w");
5972                options->close_file = 1;
5973                options->color_moved = 0;
5974                for (i = 0; i < q->nr; i++) {
5975                        struct diff_filepair *p = q->queue[i];
5976                        if (check_pair_status(p))
5977                                diff_flush_patch(p, options);
5978                        if (options->found_changes)
5979                                break;
5980                }
5981        }
5982
5983        if (output_format & DIFF_FORMAT_PATCH) {
5984                if (separator) {
5985                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5986                        if (options->stat_sep)
5987                                /* attach patch instead of inline */
5988                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5989                                                 NULL, 0, 0);
5990                }
5991
5992                diff_flush_patch_all_file_pairs(options);
5993        }
5994
5995        if (output_format & DIFF_FORMAT_CALLBACK)
5996                options->format_callback(q, options, options->format_callback_data);
5997
5998        for (i = 0; i < q->nr; i++)
5999                diff_free_filepair(q->queue[i]);
6000free_queue:
6001        free(q->queue);
6002        DIFF_QUEUE_CLEAR(q);
6003        if (options->close_file)
6004                fclose(options->file);
6005
6006        /*
6007         * Report the content-level differences with HAS_CHANGES;
6008         * diff_addremove/diff_change does not set the bit when
6009         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
6010         */
6011        if (options->flags.diff_from_contents) {
6012                if (options->found_changes)
6013                        options->flags.has_changes = 1;
6014                else
6015                        options->flags.has_changes = 0;
6016        }
6017}
6018
6019static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
6020{
6021        return (((p->status == DIFF_STATUS_MODIFIED) &&
6022                 ((p->score &&
6023                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
6024                  (!p->score &&
6025                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
6026                ((p->status != DIFF_STATUS_MODIFIED) &&
6027                 filter_bit_tst(p->status, options)));
6028}
6029
6030static void diffcore_apply_filter(struct diff_options *options)
6031{
6032        int i;
6033        struct diff_queue_struct *q = &diff_queued_diff;
6034        struct diff_queue_struct outq;
6035
6036        DIFF_QUEUE_CLEAR(&outq);
6037
6038        if (!options->filter)
6039                return;
6040
6041        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
6042                int found;
6043                for (i = found = 0; !found && i < q->nr; i++) {
6044                        if (match_filter(options, q->queue[i]))
6045                                found++;
6046                }
6047                if (found)
6048                        return;
6049
6050                /* otherwise we will clear the whole queue
6051                 * by copying the empty outq at the end of this
6052                 * function, but first clear the current entries
6053                 * in the queue.
6054                 */
6055                for (i = 0; i < q->nr; i++)
6056                        diff_free_filepair(q->queue[i]);
6057        }
6058        else {
6059                /* Only the matching ones */
6060                for (i = 0; i < q->nr; i++) {
6061                        struct diff_filepair *p = q->queue[i];
6062                        if (match_filter(options, p))
6063                                diff_q(&outq, p);
6064                        else
6065                                diff_free_filepair(p);
6066                }
6067        }
6068        free(q->queue);
6069        *q = outq;
6070}
6071
6072/* Check whether two filespecs with the same mode and size are identical */
6073static int diff_filespec_is_identical(struct repository *r,
6074                                      struct diff_filespec *one,
6075                                      struct diff_filespec *two)
6076{
6077        if (S_ISGITLINK(one->mode))
6078                return 0;
6079        if (diff_populate_filespec(r, one, 0))
6080                return 0;
6081        if (diff_populate_filespec(r, two, 0))
6082                return 0;
6083        return !memcmp(one->data, two->data, one->size);
6084}
6085
6086static int diff_filespec_check_stat_unmatch(struct repository *r,
6087                                            struct diff_filepair *p)
6088{
6089        if (p->done_skip_stat_unmatch)
6090                return p->skip_stat_unmatch_result;
6091
6092        p->done_skip_stat_unmatch = 1;
6093        p->skip_stat_unmatch_result = 0;
6094        /*
6095         * 1. Entries that come from stat info dirtiness
6096         *    always have both sides (iow, not create/delete),
6097         *    one side of the object name is unknown, with
6098         *    the same mode and size.  Keep the ones that
6099         *    do not match these criteria.  They have real
6100         *    differences.
6101         *
6102         * 2. At this point, the file is known to be modified,
6103         *    with the same mode and size, and the object
6104         *    name of one side is unknown.  Need to inspect
6105         *    the identical contents.
6106         */
6107        if (!DIFF_FILE_VALID(p->one) || /* (1) */
6108            !DIFF_FILE_VALID(p->two) ||
6109            (p->one->oid_valid && p->two->oid_valid) ||
6110            (p->one->mode != p->two->mode) ||
6111            diff_populate_filespec(r, p->one, CHECK_SIZE_ONLY) ||
6112            diff_populate_filespec(r, p->two, CHECK_SIZE_ONLY) ||
6113            (p->one->size != p->two->size) ||
6114            !diff_filespec_is_identical(r, p->one, p->two)) /* (2) */
6115                p->skip_stat_unmatch_result = 1;
6116        return p->skip_stat_unmatch_result;
6117}
6118
6119static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
6120{
6121        int i;
6122        struct diff_queue_struct *q = &diff_queued_diff;
6123        struct diff_queue_struct outq;
6124        DIFF_QUEUE_CLEAR(&outq);
6125
6126        for (i = 0; i < q->nr; i++) {
6127                struct diff_filepair *p = q->queue[i];
6128
6129                if (diff_filespec_check_stat_unmatch(diffopt->repo, p))
6130                        diff_q(&outq, p);
6131                else {
6132                        /*
6133                         * The caller can subtract 1 from skip_stat_unmatch
6134                         * to determine how many paths were dirty only
6135                         * due to stat info mismatch.
6136                         */
6137                        if (!diffopt->flags.no_index)
6138                                diffopt->skip_stat_unmatch++;
6139                        diff_free_filepair(p);
6140                }
6141        }
6142        free(q->queue);
6143        *q = outq;
6144}
6145
6146static int diffnamecmp(const void *a_, const void *b_)
6147{
6148        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6149        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6150        const char *name_a, *name_b;
6151
6152        name_a = a->one ? a->one->path : a->two->path;
6153        name_b = b->one ? b->one->path : b->two->path;
6154        return strcmp(name_a, name_b);
6155}
6156
6157void diffcore_fix_diff_index(struct diff_options *options)
6158{
6159        struct diff_queue_struct *q = &diff_queued_diff;
6160        QSORT(q->queue, q->nr, diffnamecmp);
6161}
6162
6163void diffcore_std(struct diff_options *options)
6164{
6165        /* NOTE please keep the following in sync with diff_tree_combined() */
6166        if (options->skip_stat_unmatch)
6167                diffcore_skip_stat_unmatch(options);
6168        if (!options->found_follow) {
6169                /* See try_to_follow_renames() in tree-diff.c */
6170                if (options->break_opt != -1)
6171                        diffcore_break(options->repo,
6172                                       options->break_opt);
6173                if (options->detect_rename)
6174                        diffcore_rename(options);
6175                if (options->break_opt != -1)
6176                        diffcore_merge_broken();
6177        }
6178        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6179                diffcore_pickaxe(options);
6180        if (options->orderfile)
6181                diffcore_order(options->orderfile);
6182        if (!options->found_follow)
6183                /* See try_to_follow_renames() in tree-diff.c */
6184                diff_resolve_rename_copy();
6185        diffcore_apply_filter(options);
6186
6187        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6188                options->flags.has_changes = 1;
6189        else
6190                options->flags.has_changes = 0;
6191
6192        options->found_follow = 0;
6193}
6194
6195int diff_result_code(struct diff_options *opt, int status)
6196{
6197        int result = 0;
6198
6199        diff_warn_rename_limit("diff.renameLimit",
6200                               opt->needed_rename_limit,
6201                               opt->degraded_cc_to_c);
6202        if (!opt->flags.exit_with_status &&
6203            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6204                return status;
6205        if (opt->flags.exit_with_status &&
6206            opt->flags.has_changes)
6207                result |= 01;
6208        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6209            opt->flags.check_failed)
6210                result |= 02;
6211        return result;
6212}
6213
6214int diff_can_quit_early(struct diff_options *opt)
6215{
6216        return (opt->flags.quick &&
6217                !opt->filter &&
6218                opt->flags.has_changes);
6219}
6220
6221/*
6222 * Shall changes to this submodule be ignored?
6223 *
6224 * Submodule changes can be configured to be ignored separately for each path,
6225 * but that configuration can be overridden from the command line.
6226 */
6227static int is_submodule_ignored(const char *path, struct diff_options *options)
6228{
6229        int ignored = 0;
6230        struct diff_flags orig_flags = options->flags;
6231        if (!options->flags.override_submodule_config)
6232                set_diffopt_flags_from_submodule_config(options, path);
6233        if (options->flags.ignore_submodules)
6234                ignored = 1;
6235        options->flags = orig_flags;
6236        return ignored;
6237}
6238
6239void diff_addremove(struct diff_options *options,
6240                    int addremove, unsigned mode,
6241                    const struct object_id *oid,
6242                    int oid_valid,
6243                    const char *concatpath, unsigned dirty_submodule)
6244{
6245        struct diff_filespec *one, *two;
6246
6247        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6248                return;
6249
6250        /* This may look odd, but it is a preparation for
6251         * feeding "there are unchanged files which should
6252         * not produce diffs, but when you are doing copy
6253         * detection you would need them, so here they are"
6254         * entries to the diff-core.  They will be prefixed
6255         * with something like '=' or '*' (I haven't decided
6256         * which but should not make any difference).
6257         * Feeding the same new and old to diff_change()
6258         * also has the same effect.
6259         * Before the final output happens, they are pruned after
6260         * merged into rename/copy pairs as appropriate.
6261         */
6262        if (options->flags.reverse_diff)
6263                addremove = (addremove == '+' ? '-' :
6264                             addremove == '-' ? '+' : addremove);
6265
6266        if (options->prefix &&
6267            strncmp(concatpath, options->prefix, options->prefix_length))
6268                return;
6269
6270        one = alloc_filespec(concatpath);
6271        two = alloc_filespec(concatpath);
6272
6273        if (addremove != '+')
6274                fill_filespec(one, oid, oid_valid, mode);
6275        if (addremove != '-') {
6276                fill_filespec(two, oid, oid_valid, mode);
6277                two->dirty_submodule = dirty_submodule;
6278        }
6279
6280        diff_queue(&diff_queued_diff, one, two);
6281        if (!options->flags.diff_from_contents)
6282                options->flags.has_changes = 1;
6283}
6284
6285void diff_change(struct diff_options *options,
6286                 unsigned old_mode, unsigned new_mode,
6287                 const struct object_id *old_oid,
6288                 const struct object_id *new_oid,
6289                 int old_oid_valid, int new_oid_valid,
6290                 const char *concatpath,
6291                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6292{
6293        struct diff_filespec *one, *two;
6294        struct diff_filepair *p;
6295
6296        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6297            is_submodule_ignored(concatpath, options))
6298                return;
6299
6300        if (options->flags.reverse_diff) {
6301                SWAP(old_mode, new_mode);
6302                SWAP(old_oid, new_oid);
6303                SWAP(old_oid_valid, new_oid_valid);
6304                SWAP(old_dirty_submodule, new_dirty_submodule);
6305        }
6306
6307        if (options->prefix &&
6308            strncmp(concatpath, options->prefix, options->prefix_length))
6309                return;
6310
6311        one = alloc_filespec(concatpath);
6312        two = alloc_filespec(concatpath);
6313        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6314        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6315        one->dirty_submodule = old_dirty_submodule;
6316        two->dirty_submodule = new_dirty_submodule;
6317        p = diff_queue(&diff_queued_diff, one, two);
6318
6319        if (options->flags.diff_from_contents)
6320                return;
6321
6322        if (options->flags.quick && options->skip_stat_unmatch &&
6323            !diff_filespec_check_stat_unmatch(options->repo, p))
6324                return;
6325
6326        options->flags.has_changes = 1;
6327}
6328
6329struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6330{
6331        struct diff_filepair *pair;
6332        struct diff_filespec *one, *two;
6333
6334        if (options->prefix &&
6335            strncmp(path, options->prefix, options->prefix_length))
6336                return NULL;
6337
6338        one = alloc_filespec(path);
6339        two = alloc_filespec(path);
6340        pair = diff_queue(&diff_queued_diff, one, two);
6341        pair->is_unmerged = 1;
6342        return pair;
6343}
6344
6345static char *run_textconv(struct repository *r,
6346                          const char *pgm,
6347                          struct diff_filespec *spec,
6348                          size_t *outsize)
6349{
6350        struct diff_tempfile *temp;
6351        const char *argv[3];
6352        const char **arg = argv;
6353        struct child_process child = CHILD_PROCESS_INIT;
6354        struct strbuf buf = STRBUF_INIT;
6355        int err = 0;
6356
6357        temp = prepare_temp_file(r, spec->path, spec);
6358        *arg++ = pgm;
6359        *arg++ = temp->name;
6360        *arg = NULL;
6361
6362        child.use_shell = 1;
6363        child.argv = argv;
6364        child.out = -1;
6365        if (start_command(&child)) {
6366                remove_tempfile();
6367                return NULL;
6368        }
6369
6370        if (strbuf_read(&buf, child.out, 0) < 0)
6371                err = error("error reading from textconv command '%s'", pgm);
6372        close(child.out);
6373
6374        if (finish_command(&child) || err) {
6375                strbuf_release(&buf);
6376                remove_tempfile();
6377                return NULL;
6378        }
6379        remove_tempfile();
6380
6381        return strbuf_detach(&buf, outsize);
6382}
6383
6384size_t fill_textconv(struct repository *r,
6385                     struct userdiff_driver *driver,
6386                     struct diff_filespec *df,
6387                     char **outbuf)
6388{
6389        size_t size;
6390
6391        if (!driver) {
6392                if (!DIFF_FILE_VALID(df)) {
6393                        *outbuf = "";
6394                        return 0;
6395                }
6396                if (diff_populate_filespec(r, df, 0))
6397                        die("unable to read files to diff");
6398                *outbuf = df->data;
6399                return df->size;
6400        }
6401
6402        if (!driver->textconv)
6403                BUG("fill_textconv called with non-textconv driver");
6404
6405        if (driver->textconv_cache && df->oid_valid) {
6406                *outbuf = notes_cache_get(driver->textconv_cache,
6407                                          &df->oid,
6408                                          &size);
6409                if (*outbuf)
6410                        return size;
6411        }
6412
6413        *outbuf = run_textconv(r, driver->textconv, df, &size);
6414        if (!*outbuf)
6415                die("unable to read files to diff");
6416
6417        if (driver->textconv_cache && df->oid_valid) {
6418                /* ignore errors, as we might be in a readonly repository */
6419                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6420                                size);
6421                /*
6422                 * we could save up changes and flush them all at the end,
6423                 * but we would need an extra call after all diffing is done.
6424                 * Since generating a cache entry is the slow path anyway,
6425                 * this extra overhead probably isn't a big deal.
6426                 */
6427                notes_cache_write(driver->textconv_cache);
6428        }
6429
6430        return size;
6431}
6432
6433int textconv_object(struct repository *r,
6434                    const char *path,
6435                    unsigned mode,
6436                    const struct object_id *oid,
6437                    int oid_valid,
6438                    char **buf,
6439                    unsigned long *buf_size)
6440{
6441        struct diff_filespec *df;
6442        struct userdiff_driver *textconv;
6443
6444        df = alloc_filespec(path);
6445        fill_filespec(df, oid, oid_valid, mode);
6446        textconv = get_textconv(r, df);
6447        if (!textconv) {
6448                free_filespec(df);
6449                return 0;
6450        }
6451
6452        *buf_size = fill_textconv(r, textconv, df, buf);
6453        free_filespec(df);
6454        return 1;
6455}
6456
6457void setup_diff_pager(struct diff_options *opt)
6458{
6459        /*
6460         * If the user asked for our exit code, then either they want --quiet
6461         * or --exit-code. We should definitely not bother with a pager in the
6462         * former case, as we will generate no output. Since we still properly
6463         * report our exit code even when a pager is run, we _could_ run a
6464         * pager with --exit-code. But since we have not done so historically,
6465         * and because it is easy to find people oneline advising "git diff
6466         * --exit-code" in hooks and other scripts, we do not do so.
6467         */
6468        if (!opt->flags.exit_with_status &&
6469            check_pager_config("diff") != 0)
6470                setup_pager();
6471}