diff.con commit Merge branch 'nd/pack-objects-threading-doc' (2e2c24f)
   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};
  74
  75static const char *color_diff_slots[] = {
  76        [DIFF_CONTEXT]                = "context",
  77        [DIFF_METAINFO]               = "meta",
  78        [DIFF_FRAGINFO]               = "frag",
  79        [DIFF_FILE_OLD]               = "old",
  80        [DIFF_FILE_NEW]               = "new",
  81        [DIFF_COMMIT]                 = "commit",
  82        [DIFF_WHITESPACE]             = "whitespace",
  83        [DIFF_FUNCINFO]               = "func",
  84        [DIFF_FILE_OLD_MOVED]         = "oldMoved",
  85        [DIFF_FILE_OLD_MOVED_ALT]     = "oldMovedAlternative",
  86        [DIFF_FILE_OLD_MOVED_DIM]     = "oldMovedDimmed",
  87        [DIFF_FILE_OLD_MOVED_ALT_DIM] = "oldMovedAlternativeDimmed",
  88        [DIFF_FILE_NEW_MOVED]         = "newMoved",
  89        [DIFF_FILE_NEW_MOVED_ALT]     = "newMovedAlternative",
  90        [DIFF_FILE_NEW_MOVED_DIM]     = "newMovedDimmed",
  91        [DIFF_FILE_NEW_MOVED_ALT_DIM] = "newMovedAlternativeDimmed",
  92};
  93
  94static NORETURN void die_want_option(const char *option_name)
  95{
  96        die(_("option '%s' requires a value"), option_name);
  97}
  98
  99define_list_config_array_extra(color_diff_slots, {"plain"});
 100
 101static int parse_diff_color_slot(const char *var)
 102{
 103        if (!strcasecmp(var, "plain"))
 104                return DIFF_CONTEXT;
 105        return LOOKUP_CONFIG(color_diff_slots, var);
 106}
 107
 108static int parse_dirstat_params(struct diff_options *options, const char *params_string,
 109                                struct strbuf *errmsg)
 110{
 111        char *params_copy = xstrdup(params_string);
 112        struct string_list params = STRING_LIST_INIT_NODUP;
 113        int ret = 0;
 114        int i;
 115
 116        if (*params_copy)
 117                string_list_split_in_place(&params, params_copy, ',', -1);
 118        for (i = 0; i < params.nr; i++) {
 119                const char *p = params.items[i].string;
 120                if (!strcmp(p, "changes")) {
 121                        options->flags.dirstat_by_line = 0;
 122                        options->flags.dirstat_by_file = 0;
 123                } else if (!strcmp(p, "lines")) {
 124                        options->flags.dirstat_by_line = 1;
 125                        options->flags.dirstat_by_file = 0;
 126                } else if (!strcmp(p, "files")) {
 127                        options->flags.dirstat_by_line = 0;
 128                        options->flags.dirstat_by_file = 1;
 129                } else if (!strcmp(p, "noncumulative")) {
 130                        options->flags.dirstat_cumulative = 0;
 131                } else if (!strcmp(p, "cumulative")) {
 132                        options->flags.dirstat_cumulative = 1;
 133                } else if (isdigit(*p)) {
 134                        char *end;
 135                        int permille = strtoul(p, &end, 10) * 10;
 136                        if (*end == '.' && isdigit(*++end)) {
 137                                /* only use first digit */
 138                                permille += *end - '0';
 139                                /* .. and ignore any further digits */
 140                                while (isdigit(*++end))
 141                                        ; /* nothing */
 142                        }
 143                        if (!*end)
 144                                options->dirstat_permille = permille;
 145                        else {
 146                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 147                                            p);
 148                                ret++;
 149                        }
 150                } else {
 151                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 152                        ret++;
 153                }
 154
 155        }
 156        string_list_clear(&params, 0);
 157        free(params_copy);
 158        return ret;
 159}
 160
 161static int parse_submodule_params(struct diff_options *options, const char *value)
 162{
 163        if (!strcmp(value, "log"))
 164                options->submodule_format = DIFF_SUBMODULE_LOG;
 165        else if (!strcmp(value, "short"))
 166                options->submodule_format = DIFF_SUBMODULE_SHORT;
 167        else if (!strcmp(value, "diff"))
 168                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 169        else
 170                return -1;
 171        return 0;
 172}
 173
 174int git_config_rename(const char *var, const char *value)
 175{
 176        if (!value)
 177                return DIFF_DETECT_RENAME;
 178        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 179                return  DIFF_DETECT_COPY;
 180        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 181}
 182
 183long parse_algorithm_value(const char *value)
 184{
 185        if (!value)
 186                return -1;
 187        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 188                return 0;
 189        else if (!strcasecmp(value, "minimal"))
 190                return XDF_NEED_MINIMAL;
 191        else if (!strcasecmp(value, "patience"))
 192                return XDF_PATIENCE_DIFF;
 193        else if (!strcasecmp(value, "histogram"))
 194                return XDF_HISTOGRAM_DIFF;
 195        return -1;
 196}
 197
 198static int parse_one_token(const char **arg, const char *token)
 199{
 200        const char *rest;
 201        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 202                *arg = rest;
 203                return 1;
 204        }
 205        return 0;
 206}
 207
 208static int parse_ws_error_highlight(const char *arg)
 209{
 210        const char *orig_arg = arg;
 211        unsigned val = 0;
 212
 213        while (*arg) {
 214                if (parse_one_token(&arg, "none"))
 215                        val = 0;
 216                else if (parse_one_token(&arg, "default"))
 217                        val = WSEH_NEW;
 218                else if (parse_one_token(&arg, "all"))
 219                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 220                else if (parse_one_token(&arg, "new"))
 221                        val |= WSEH_NEW;
 222                else if (parse_one_token(&arg, "old"))
 223                        val |= WSEH_OLD;
 224                else if (parse_one_token(&arg, "context"))
 225                        val |= WSEH_CONTEXT;
 226                else {
 227                        return -1 - (int)(arg - orig_arg);
 228                }
 229                if (*arg)
 230                        arg++;
 231        }
 232        return val;
 233}
 234
 235/*
 236 * These are to give UI layer defaults.
 237 * The core-level commands such as git-diff-files should
 238 * never be affected by the setting of diff.renames
 239 * the user happens to have in the configuration file.
 240 */
 241void init_diff_ui_defaults(void)
 242{
 243        diff_detect_rename_default = DIFF_DETECT_RENAME;
 244}
 245
 246int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 247{
 248        if (!strcmp(var, "diff.indentheuristic"))
 249                diff_indent_heuristic = git_config_bool(var, value);
 250        return 0;
 251}
 252
 253static int parse_color_moved(const char *arg)
 254{
 255        switch (git_parse_maybe_bool(arg)) {
 256        case 0:
 257                return COLOR_MOVED_NO;
 258        case 1:
 259                return COLOR_MOVED_DEFAULT;
 260        default:
 261                break;
 262        }
 263
 264        if (!strcmp(arg, "no"))
 265                return COLOR_MOVED_NO;
 266        else if (!strcmp(arg, "plain"))
 267                return COLOR_MOVED_PLAIN;
 268        else if (!strcmp(arg, "blocks"))
 269                return COLOR_MOVED_BLOCKS;
 270        else if (!strcmp(arg, "zebra"))
 271                return COLOR_MOVED_ZEBRA;
 272        else if (!strcmp(arg, "default"))
 273                return COLOR_MOVED_DEFAULT;
 274        else if (!strcmp(arg, "dimmed-zebra"))
 275                return COLOR_MOVED_ZEBRA_DIM;
 276        else if (!strcmp(arg, "dimmed_zebra"))
 277                return COLOR_MOVED_ZEBRA_DIM;
 278        else
 279                return error(_("color moved setting must be one of 'no', 'default', 'blocks', 'zebra', 'dimmed-zebra', 'plain'"));
 280}
 281
 282static int parse_color_moved_ws(const char *arg)
 283{
 284        int ret = 0;
 285        struct string_list l = STRING_LIST_INIT_DUP;
 286        struct string_list_item *i;
 287
 288        string_list_split(&l, arg, ',', -1);
 289
 290        for_each_string_list_item(i, &l) {
 291                struct strbuf sb = STRBUF_INIT;
 292                strbuf_addstr(&sb, i->string);
 293                strbuf_trim(&sb);
 294
 295                if (!strcmp(sb.buf, "ignore-space-change"))
 296                        ret |= XDF_IGNORE_WHITESPACE_CHANGE;
 297                else if (!strcmp(sb.buf, "ignore-space-at-eol"))
 298                        ret |= XDF_IGNORE_WHITESPACE_AT_EOL;
 299                else if (!strcmp(sb.buf, "ignore-all-space"))
 300                        ret |= XDF_IGNORE_WHITESPACE;
 301                else if (!strcmp(sb.buf, "allow-indentation-change"))
 302                        ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
 303                else
 304                        error(_("ignoring unknown color-moved-ws mode '%s'"), sb.buf);
 305
 306                strbuf_release(&sb);
 307        }
 308
 309        if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
 310            (ret & XDF_WHITESPACE_FLAGS))
 311                die(_("color-moved-ws: allow-indentation-change cannot be combined with other white space modes"));
 312
 313        string_list_clear(&l, 0);
 314
 315        return ret;
 316}
 317
 318int git_diff_ui_config(const char *var, const char *value, void *cb)
 319{
 320        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 321                diff_use_color_default = git_config_colorbool(var, value);
 322                return 0;
 323        }
 324        if (!strcmp(var, "diff.colormoved")) {
 325                int cm = parse_color_moved(value);
 326                if (cm < 0)
 327                        return -1;
 328                diff_color_moved_default = cm;
 329                return 0;
 330        }
 331        if (!strcmp(var, "diff.colormovedws")) {
 332                int cm = parse_color_moved_ws(value);
 333                if (cm < 0)
 334                        return -1;
 335                diff_color_moved_ws_default = cm;
 336                return 0;
 337        }
 338        if (!strcmp(var, "diff.context")) {
 339                diff_context_default = git_config_int(var, value);
 340                if (diff_context_default < 0)
 341                        return -1;
 342                return 0;
 343        }
 344        if (!strcmp(var, "diff.interhunkcontext")) {
 345                diff_interhunk_context_default = git_config_int(var, value);
 346                if (diff_interhunk_context_default < 0)
 347                        return -1;
 348                return 0;
 349        }
 350        if (!strcmp(var, "diff.renames")) {
 351                diff_detect_rename_default = git_config_rename(var, value);
 352                return 0;
 353        }
 354        if (!strcmp(var, "diff.autorefreshindex")) {
 355                diff_auto_refresh_index = git_config_bool(var, value);
 356                return 0;
 357        }
 358        if (!strcmp(var, "diff.mnemonicprefix")) {
 359                diff_mnemonic_prefix = git_config_bool(var, value);
 360                return 0;
 361        }
 362        if (!strcmp(var, "diff.noprefix")) {
 363                diff_no_prefix = git_config_bool(var, value);
 364                return 0;
 365        }
 366        if (!strcmp(var, "diff.statgraphwidth")) {
 367                diff_stat_graph_width = git_config_int(var, value);
 368                return 0;
 369        }
 370        if (!strcmp(var, "diff.external"))
 371                return git_config_string(&external_diff_cmd_cfg, var, value);
 372        if (!strcmp(var, "diff.wordregex"))
 373                return git_config_string(&diff_word_regex_cfg, var, value);
 374        if (!strcmp(var, "diff.orderfile"))
 375                return git_config_pathname(&diff_order_file_cfg, var, value);
 376
 377        if (!strcmp(var, "diff.ignoresubmodules"))
 378                handle_ignore_submodules_arg(&default_diff_options, value);
 379
 380        if (!strcmp(var, "diff.submodule")) {
 381                if (parse_submodule_params(&default_diff_options, value))
 382                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 383                                value);
 384                return 0;
 385        }
 386
 387        if (!strcmp(var, "diff.algorithm")) {
 388                diff_algorithm = parse_algorithm_value(value);
 389                if (diff_algorithm < 0)
 390                        return -1;
 391                return 0;
 392        }
 393
 394        if (!strcmp(var, "diff.wserrorhighlight")) {
 395                int val = parse_ws_error_highlight(value);
 396                if (val < 0)
 397                        return -1;
 398                ws_error_highlight_default = val;
 399                return 0;
 400        }
 401
 402        if (git_color_config(var, value, cb) < 0)
 403                return -1;
 404
 405        return git_diff_basic_config(var, value, cb);
 406}
 407
 408int git_diff_basic_config(const char *var, const char *value, void *cb)
 409{
 410        const char *name;
 411
 412        if (!strcmp(var, "diff.renamelimit")) {
 413                diff_rename_limit_default = git_config_int(var, value);
 414                return 0;
 415        }
 416
 417        if (userdiff_config(var, value) < 0)
 418                return -1;
 419
 420        if (skip_prefix(var, "diff.color.", &name) ||
 421            skip_prefix(var, "color.diff.", &name)) {
 422                int slot = parse_diff_color_slot(name);
 423                if (slot < 0)
 424                        return 0;
 425                if (!value)
 426                        return config_error_nonbool(var);
 427                return color_parse(value, diff_colors[slot]);
 428        }
 429
 430        /* like GNU diff's --suppress-blank-empty option  */
 431        if (!strcmp(var, "diff.suppressblankempty") ||
 432                        /* for backwards compatibility */
 433                        !strcmp(var, "diff.suppress-blank-empty")) {
 434                diff_suppress_blank_empty = git_config_bool(var, value);
 435                return 0;
 436        }
 437
 438        if (!strcmp(var, "diff.dirstat")) {
 439                struct strbuf errmsg = STRBUF_INIT;
 440                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 441                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 442                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 443                                errmsg.buf);
 444                strbuf_release(&errmsg);
 445                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 446                return 0;
 447        }
 448
 449        if (git_diff_heuristic_config(var, value, cb) < 0)
 450                return -1;
 451
 452        return git_default_config(var, value, cb);
 453}
 454
 455static char *quote_two(const char *one, const char *two)
 456{
 457        int need_one = quote_c_style(one, NULL, NULL, 1);
 458        int need_two = quote_c_style(two, NULL, NULL, 1);
 459        struct strbuf res = STRBUF_INIT;
 460
 461        if (need_one + need_two) {
 462                strbuf_addch(&res, '"');
 463                quote_c_style(one, &res, NULL, 1);
 464                quote_c_style(two, &res, NULL, 1);
 465                strbuf_addch(&res, '"');
 466        } else {
 467                strbuf_addstr(&res, one);
 468                strbuf_addstr(&res, two);
 469        }
 470        return strbuf_detach(&res, NULL);
 471}
 472
 473static const char *external_diff(void)
 474{
 475        static const char *external_diff_cmd = NULL;
 476        static int done_preparing = 0;
 477
 478        if (done_preparing)
 479                return external_diff_cmd;
 480        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 481        if (!external_diff_cmd)
 482                external_diff_cmd = external_diff_cmd_cfg;
 483        done_preparing = 1;
 484        return external_diff_cmd;
 485}
 486
 487/*
 488 * Keep track of files used for diffing. Sometimes such an entry
 489 * refers to a temporary file, sometimes to an existing file, and
 490 * sometimes to "/dev/null".
 491 */
 492static struct diff_tempfile {
 493        /*
 494         * filename external diff should read from, or NULL if this
 495         * entry is currently not in use:
 496         */
 497        const char *name;
 498
 499        char hex[GIT_MAX_HEXSZ + 1];
 500        char mode[10];
 501
 502        /*
 503         * If this diff_tempfile instance refers to a temporary file,
 504         * this tempfile object is used to manage its lifetime.
 505         */
 506        struct tempfile *tempfile;
 507} diff_temp[2];
 508
 509struct emit_callback {
 510        int color_diff;
 511        unsigned ws_rule;
 512        int blank_at_eof_in_preimage;
 513        int blank_at_eof_in_postimage;
 514        int lno_in_preimage;
 515        int lno_in_postimage;
 516        const char **label_path;
 517        struct diff_words_data *diff_words;
 518        struct diff_options *opt;
 519        struct strbuf *header;
 520};
 521
 522static int count_lines(const char *data, int size)
 523{
 524        int count, ch, completely_empty = 1, nl_just_seen = 0;
 525        count = 0;
 526        while (0 < size--) {
 527                ch = *data++;
 528                if (ch == '\n') {
 529                        count++;
 530                        nl_just_seen = 1;
 531                        completely_empty = 0;
 532                }
 533                else {
 534                        nl_just_seen = 0;
 535                        completely_empty = 0;
 536                }
 537        }
 538        if (completely_empty)
 539                return 0;
 540        if (!nl_just_seen)
 541                count++; /* no trailing newline */
 542        return count;
 543}
 544
 545static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 546{
 547        if (!DIFF_FILE_VALID(one)) {
 548                mf->ptr = (char *)""; /* does not matter */
 549                mf->size = 0;
 550                return 0;
 551        }
 552        else if (diff_populate_filespec(one, 0))
 553                return -1;
 554
 555        mf->ptr = one->data;
 556        mf->size = one->size;
 557        return 0;
 558}
 559
 560/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 561static unsigned long diff_filespec_size(struct diff_filespec *one)
 562{
 563        if (!DIFF_FILE_VALID(one))
 564                return 0;
 565        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 566        return one->size;
 567}
 568
 569static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 570{
 571        char *ptr = mf->ptr;
 572        long size = mf->size;
 573        int cnt = 0;
 574
 575        if (!size)
 576                return cnt;
 577        ptr += size - 1; /* pointing at the very end */
 578        if (*ptr != '\n')
 579                ; /* incomplete line */
 580        else
 581                ptr--; /* skip the last LF */
 582        while (mf->ptr < ptr) {
 583                char *prev_eol;
 584                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 585                        if (*prev_eol == '\n')
 586                                break;
 587                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 588                        break;
 589                cnt++;
 590                ptr = prev_eol - 1;
 591        }
 592        return cnt;
 593}
 594
 595static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 596                               struct emit_callback *ecbdata)
 597{
 598        int l1, l2, at;
 599        unsigned ws_rule = ecbdata->ws_rule;
 600        l1 = count_trailing_blank(mf1, ws_rule);
 601        l2 = count_trailing_blank(mf2, ws_rule);
 602        if (l2 <= l1) {
 603                ecbdata->blank_at_eof_in_preimage = 0;
 604                ecbdata->blank_at_eof_in_postimage = 0;
 605                return;
 606        }
 607        at = count_lines(mf1->ptr, mf1->size);
 608        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 609
 610        at = count_lines(mf2->ptr, mf2->size);
 611        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 612}
 613
 614static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 615                        int first, const char *line, int len)
 616{
 617        int has_trailing_newline, has_trailing_carriage_return;
 618        int nofirst;
 619        FILE *file = o->file;
 620
 621        fputs(diff_line_prefix(o), file);
 622
 623        if (len == 0) {
 624                has_trailing_newline = (first == '\n');
 625                has_trailing_carriage_return = (!has_trailing_newline &&
 626                                                (first == '\r'));
 627                nofirst = has_trailing_newline || has_trailing_carriage_return;
 628        } else {
 629                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 630                if (has_trailing_newline)
 631                        len--;
 632                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 633                if (has_trailing_carriage_return)
 634                        len--;
 635                nofirst = 0;
 636        }
 637
 638        if (len || !nofirst) {
 639                fputs(set, file);
 640                if (!nofirst)
 641                        fputc(first, file);
 642                fwrite(line, len, 1, file);
 643                fputs(reset, file);
 644        }
 645        if (has_trailing_carriage_return)
 646                fputc('\r', file);
 647        if (has_trailing_newline)
 648                fputc('\n', file);
 649}
 650
 651static void emit_line(struct diff_options *o, const char *set, const char *reset,
 652                      const char *line, int len)
 653{
 654        emit_line_0(o, set, reset, line[0], line+1, len-1);
 655}
 656
 657enum diff_symbol {
 658        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 659        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 660        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 661        DIFF_SYMBOL_BINARY_DIFF_BODY,
 662        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 663        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 664        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 665        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 666        DIFF_SYMBOL_STATS_LINE,
 667        DIFF_SYMBOL_WORD_DIFF,
 668        DIFF_SYMBOL_STAT_SEP,
 669        DIFF_SYMBOL_SUMMARY,
 670        DIFF_SYMBOL_SUBMODULE_ADD,
 671        DIFF_SYMBOL_SUBMODULE_DEL,
 672        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 673        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 674        DIFF_SYMBOL_SUBMODULE_HEADER,
 675        DIFF_SYMBOL_SUBMODULE_ERROR,
 676        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 677        DIFF_SYMBOL_REWRITE_DIFF,
 678        DIFF_SYMBOL_BINARY_FILES,
 679        DIFF_SYMBOL_HEADER,
 680        DIFF_SYMBOL_FILEPAIR_PLUS,
 681        DIFF_SYMBOL_FILEPAIR_MINUS,
 682        DIFF_SYMBOL_WORDS_PORCELAIN,
 683        DIFF_SYMBOL_WORDS,
 684        DIFF_SYMBOL_CONTEXT,
 685        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 686        DIFF_SYMBOL_PLUS,
 687        DIFF_SYMBOL_MINUS,
 688        DIFF_SYMBOL_NO_LF_EOF,
 689        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 690        DIFF_SYMBOL_CONTEXT_MARKER,
 691        DIFF_SYMBOL_SEPARATOR
 692};
 693/*
 694 * Flags for content lines:
 695 * 0..12 are whitespace rules
 696 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 697 * 16 is marking if the line is blank at EOF
 698 */
 699#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 700#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 701#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 702#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 703#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 704
 705/*
 706 * This struct is used when we need to buffer the output of the diff output.
 707 *
 708 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 709 * into the pre/post image file. This pointer could be a union with the
 710 * line pointer. By storing an offset into the file instead of the literal line,
 711 * we can decrease the memory footprint for the buffered output. At first we
 712 * may want to only have indirection for the content lines, but we could also
 713 * enhance the state for emitting prefabricated lines, e.g. the similarity
 714 * score line or hunk/file headers would only need to store a number or path
 715 * and then the output can be constructed later on depending on state.
 716 */
 717struct emitted_diff_symbol {
 718        const char *line;
 719        int len;
 720        int flags;
 721        enum diff_symbol s;
 722};
 723#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 724
 725struct emitted_diff_symbols {
 726        struct emitted_diff_symbol *buf;
 727        int nr, alloc;
 728};
 729#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 730
 731static void append_emitted_diff_symbol(struct diff_options *o,
 732                                       struct emitted_diff_symbol *e)
 733{
 734        struct emitted_diff_symbol *f;
 735
 736        ALLOC_GROW(o->emitted_symbols->buf,
 737                   o->emitted_symbols->nr + 1,
 738                   o->emitted_symbols->alloc);
 739        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 740
 741        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 742        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 743}
 744
 745struct moved_entry {
 746        struct hashmap_entry ent;
 747        const struct emitted_diff_symbol *es;
 748        struct moved_entry *next_line;
 749        struct ws_delta *wsd;
 750};
 751
 752/**
 753 * The struct ws_delta holds white space differences between moved lines, i.e.
 754 * between '+' and '-' lines that have been detected to be a move.
 755 * The string contains the difference in leading white spaces, before the
 756 * rest of the line is compared using the white space config for move
 757 * coloring. The current_longer indicates if the first string in the
 758 * comparision is longer than the second.
 759 */
 760struct ws_delta {
 761        char *string;
 762        unsigned int current_longer : 1;
 763};
 764#define WS_DELTA_INIT { NULL, 0 }
 765
 766static int compute_ws_delta(const struct emitted_diff_symbol *a,
 767                             const struct emitted_diff_symbol *b,
 768                             struct ws_delta *out)
 769{
 770        const struct emitted_diff_symbol *longer =  a->len > b->len ? a : b;
 771        const struct emitted_diff_symbol *shorter = a->len > b->len ? b : a;
 772        int d = longer->len - shorter->len;
 773
 774        out->string = xmemdupz(longer->line, d);
 775        out->current_longer = (a == longer);
 776
 777        return !strncmp(longer->line + d, shorter->line, shorter->len);
 778}
 779
 780static int cmp_in_block_with_wsd(const struct diff_options *o,
 781                                 const struct moved_entry *cur,
 782                                 const struct moved_entry *match,
 783                                 struct moved_entry *pmb,
 784                                 int n)
 785{
 786        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 787        int al = cur->es->len, cl = l->len;
 788        const char *a = cur->es->line,
 789                   *b = match->es->line,
 790                   *c = l->line;
 791
 792        int wslen;
 793
 794        /*
 795         * We need to check if 'cur' is equal to 'match'.
 796         * As those are from the same (+/-) side, we do not need to adjust for
 797         * indent changes. However these were found using fuzzy matching
 798         * so we do have to check if they are equal.
 799         */
 800        if (strcmp(a, b))
 801                return 1;
 802
 803        if (!pmb->wsd)
 804                /*
 805                 * No white space delta was carried forward? This can happen
 806                 * when we exit early in this function and do not carry
 807                 * forward ws.
 808                 */
 809                return 1;
 810
 811        /*
 812         * The indent changes of the block are known and carried forward in
 813         * pmb->wsd; however we need to check if the indent changes of the
 814         * current line are still the same as before.
 815         *
 816         * To do so we need to compare 'l' to 'cur', adjusting the
 817         * one of them for the white spaces, depending which was longer.
 818         */
 819
 820        wslen = strlen(pmb->wsd->string);
 821        if (pmb->wsd->current_longer) {
 822                c += wslen;
 823                cl -= wslen;
 824        } else {
 825                a += wslen;
 826                al -= wslen;
 827        }
 828
 829        if (strcmp(a, c))
 830                return 1;
 831
 832        return 0;
 833}
 834
 835static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 836                           const void *entry,
 837                           const void *entry_or_key,
 838                           const void *keydata)
 839{
 840        const struct diff_options *diffopt = hashmap_cmp_fn_data;
 841        const struct moved_entry *a = entry;
 842        const struct moved_entry *b = entry_or_key;
 843        unsigned flags = diffopt->color_moved_ws_handling
 844                         & XDF_WHITESPACE_FLAGS;
 845
 846        if (diffopt->color_moved_ws_handling &
 847            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 848                /*
 849                 * As there is not specific white space config given,
 850                 * we'd need to check for a new block, so ignore all
 851                 * white space. The setup of the white space
 852                 * configuration for the next block is done else where
 853                 */
 854                flags |= XDF_IGNORE_WHITESPACE;
 855
 856        return !xdiff_compare_lines(a->es->line, a->es->len,
 857                                    b->es->line, b->es->len,
 858                                    flags);
 859}
 860
 861static struct moved_entry *prepare_entry(struct diff_options *o,
 862                                         int line_no)
 863{
 864        struct moved_entry *ret = xmalloc(sizeof(*ret));
 865        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 866        unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 867
 868        ret->ent.hash = xdiff_hash_string(l->line, l->len, flags);
 869        ret->es = l;
 870        ret->next_line = NULL;
 871        ret->wsd = NULL;
 872
 873        return ret;
 874}
 875
 876static void add_lines_to_move_detection(struct diff_options *o,
 877                                        struct hashmap *add_lines,
 878                                        struct hashmap *del_lines)
 879{
 880        struct moved_entry *prev_line = NULL;
 881
 882        int n;
 883        for (n = 0; n < o->emitted_symbols->nr; n++) {
 884                struct hashmap *hm;
 885                struct moved_entry *key;
 886
 887                switch (o->emitted_symbols->buf[n].s) {
 888                case DIFF_SYMBOL_PLUS:
 889                        hm = add_lines;
 890                        break;
 891                case DIFF_SYMBOL_MINUS:
 892                        hm = del_lines;
 893                        break;
 894                default:
 895                        prev_line = NULL;
 896                        continue;
 897                }
 898
 899                key = prepare_entry(o, n);
 900                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 901                        prev_line->next_line = key;
 902
 903                hashmap_add(hm, key);
 904                prev_line = key;
 905        }
 906}
 907
 908static void pmb_advance_or_null(struct diff_options *o,
 909                                struct moved_entry *match,
 910                                struct hashmap *hm,
 911                                struct moved_entry **pmb,
 912                                int pmb_nr)
 913{
 914        int i;
 915        for (i = 0; i < pmb_nr; i++) {
 916                struct moved_entry *prev = pmb[i];
 917                struct moved_entry *cur = (prev && prev->next_line) ?
 918                                prev->next_line : NULL;
 919                if (cur && !hm->cmpfn(o, cur, match, NULL)) {
 920                        pmb[i] = cur;
 921                } else {
 922                        pmb[i] = NULL;
 923                }
 924        }
 925}
 926
 927static void pmb_advance_or_null_multi_match(struct diff_options *o,
 928                                            struct moved_entry *match,
 929                                            struct hashmap *hm,
 930                                            struct moved_entry **pmb,
 931                                            int pmb_nr, int n)
 932{
 933        int i;
 934        char *got_match = xcalloc(1, pmb_nr);
 935
 936        for (; match; match = hashmap_get_next(hm, match)) {
 937                for (i = 0; i < pmb_nr; i++) {
 938                        struct moved_entry *prev = pmb[i];
 939                        struct moved_entry *cur = (prev && prev->next_line) ?
 940                                        prev->next_line : NULL;
 941                        if (!cur)
 942                                continue;
 943                        if (!cmp_in_block_with_wsd(o, cur, match, pmb[i], n))
 944                                got_match[i] |= 1;
 945                }
 946        }
 947
 948        for (i = 0; i < pmb_nr; i++) {
 949                if (got_match[i]) {
 950                        /* Carry the white space delta forward */
 951                        pmb[i]->next_line->wsd = pmb[i]->wsd;
 952                        pmb[i] = pmb[i]->next_line;
 953                } else
 954                        pmb[i] = NULL;
 955        }
 956}
 957
 958static int shrink_potential_moved_blocks(struct moved_entry **pmb,
 959                                         int pmb_nr)
 960{
 961        int lp, rp;
 962
 963        /* Shrink the set of potential block to the remaining running */
 964        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
 965                while (lp < pmb_nr && pmb[lp])
 966                        lp++;
 967                /* lp points at the first NULL now */
 968
 969                while (rp > -1 && !pmb[rp])
 970                        rp--;
 971                /* rp points at the last non-NULL */
 972
 973                if (lp < pmb_nr && rp > -1 && lp < rp) {
 974                        pmb[lp] = pmb[rp];
 975                        if (pmb[rp]->wsd) {
 976                                free(pmb[rp]->wsd->string);
 977                                FREE_AND_NULL(pmb[rp]->wsd);
 978                        }
 979                        pmb[rp] = NULL;
 980                        rp--;
 981                        lp++;
 982                }
 983        }
 984
 985        /* Remember the number of running sets */
 986        return rp + 1;
 987}
 988
 989/*
 990 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
 991 *
 992 * Otherwise, if the last block has fewer alphanumeric characters than
 993 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
 994 * that block.
 995 *
 996 * The last block consists of the (n - block_length)'th line up to but not
 997 * including the nth line.
 998 *
 999 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
1000 * Think of a way to unify them.
1001 */
1002static void adjust_last_block(struct diff_options *o, int n, int block_length)
1003{
1004        int i, alnum_count = 0;
1005        if (o->color_moved == COLOR_MOVED_PLAIN)
1006                return;
1007        for (i = 1; i < block_length + 1; i++) {
1008                const char *c = o->emitted_symbols->buf[n - i].line;
1009                for (; *c; c++) {
1010                        if (!isalnum(*c))
1011                                continue;
1012                        alnum_count++;
1013                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
1014                                return;
1015                }
1016        }
1017        for (i = 1; i < block_length + 1; i++)
1018                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
1019}
1020
1021/* Find blocks of moved code, delegate actual coloring decision to helper */
1022static void mark_color_as_moved(struct diff_options *o,
1023                                struct hashmap *add_lines,
1024                                struct hashmap *del_lines)
1025{
1026        struct moved_entry **pmb = NULL; /* potentially moved blocks */
1027        int pmb_nr = 0, pmb_alloc = 0;
1028        int n, flipped_block = 1, block_length = 0;
1029
1030
1031        for (n = 0; n < o->emitted_symbols->nr; n++) {
1032                struct hashmap *hm = NULL;
1033                struct moved_entry *key;
1034                struct moved_entry *match = NULL;
1035                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1036
1037                switch (l->s) {
1038                case DIFF_SYMBOL_PLUS:
1039                        hm = del_lines;
1040                        key = prepare_entry(o, n);
1041                        match = hashmap_get(hm, key, NULL);
1042                        free(key);
1043                        break;
1044                case DIFF_SYMBOL_MINUS:
1045                        hm = add_lines;
1046                        key = prepare_entry(o, n);
1047                        match = hashmap_get(hm, key, NULL);
1048                        free(key);
1049                        break;
1050                default:
1051                        flipped_block = 1;
1052                }
1053
1054                if (!match) {
1055                        adjust_last_block(o, n, block_length);
1056                        pmb_nr = 0;
1057                        block_length = 0;
1058                        continue;
1059                }
1060
1061                l->flags |= DIFF_SYMBOL_MOVED_LINE;
1062
1063                if (o->color_moved == COLOR_MOVED_PLAIN)
1064                        continue;
1065
1066                if (o->color_moved_ws_handling &
1067                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1068                        pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
1069                else
1070                        pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
1071
1072                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
1073
1074                if (pmb_nr == 0) {
1075                        /*
1076                         * The current line is the start of a new block.
1077                         * Setup the set of potential blocks.
1078                         */
1079                        for (; match; match = hashmap_get_next(hm, match)) {
1080                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
1081                                if (o->color_moved_ws_handling &
1082                                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
1083                                        struct ws_delta *wsd = xmalloc(sizeof(*match->wsd));
1084                                        if (compute_ws_delta(l, match->es, wsd)) {
1085                                                match->wsd = wsd;
1086                                                pmb[pmb_nr++] = match;
1087                                        } else
1088                                                free(wsd);
1089                                } else {
1090                                        pmb[pmb_nr++] = match;
1091                                }
1092                        }
1093
1094                        flipped_block = (flipped_block + 1) % 2;
1095
1096                        adjust_last_block(o, n, block_length);
1097                        block_length = 0;
1098                }
1099
1100                block_length++;
1101
1102                if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
1103                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
1104        }
1105        adjust_last_block(o, n, block_length);
1106
1107        free(pmb);
1108}
1109
1110#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
1111  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
1112static void dim_moved_lines(struct diff_options *o)
1113{
1114        int n;
1115        for (n = 0; n < o->emitted_symbols->nr; n++) {
1116                struct emitted_diff_symbol *prev = (n != 0) ?
1117                                &o->emitted_symbols->buf[n - 1] : NULL;
1118                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1119                struct emitted_diff_symbol *next =
1120                                (n < o->emitted_symbols->nr - 1) ?
1121                                &o->emitted_symbols->buf[n + 1] : NULL;
1122
1123                /* Not a plus or minus line? */
1124                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
1125                        continue;
1126
1127                /* Not a moved line? */
1128                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
1129                        continue;
1130
1131                /*
1132                 * If prev or next are not a plus or minus line,
1133                 * pretend they don't exist
1134                 */
1135                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1136                            prev->s != DIFF_SYMBOL_MINUS)
1137                        prev = NULL;
1138                if (next && next->s != DIFF_SYMBOL_PLUS &&
1139                            next->s != DIFF_SYMBOL_MINUS)
1140                        next = NULL;
1141
1142                /* Inside a block? */
1143                if ((prev &&
1144                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1145                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1146                    (next &&
1147                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1148                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1149                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1150                        continue;
1151                }
1152
1153                /* Check if we are at an interesting bound: */
1154                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1155                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1156                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1157                        continue;
1158                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1159                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1160                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1161                        continue;
1162
1163                /*
1164                 * The boundary to prev and next are not interesting,
1165                 * so this line is not interesting as a whole
1166                 */
1167                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1168        }
1169}
1170
1171static void emit_line_ws_markup(struct diff_options *o,
1172                                const char *set, const char *reset,
1173                                const char *line, int len, char sign,
1174                                unsigned ws_rule, int blank_at_eof)
1175{
1176        const char *ws = NULL;
1177
1178        if (o->ws_error_highlight & ws_rule) {
1179                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1180                if (!*ws)
1181                        ws = NULL;
1182        }
1183
1184        if (!ws)
1185                emit_line_0(o, set, reset, sign, line, len);
1186        else if (blank_at_eof)
1187                /* Blank line at EOF - paint '+' as well */
1188                emit_line_0(o, ws, reset, sign, line, len);
1189        else {
1190                /* Emit just the prefix, then the rest. */
1191                emit_line_0(o, set, reset, sign, "", 0);
1192                ws_check_emit(line, len, ws_rule,
1193                              o->file, set, reset, ws);
1194        }
1195}
1196
1197static void emit_diff_symbol_from_struct(struct diff_options *o,
1198                                         struct emitted_diff_symbol *eds)
1199{
1200        static const char *nneof = " No newline at end of file\n";
1201        const char *context, *reset, *set, *meta, *fraginfo;
1202        struct strbuf sb = STRBUF_INIT;
1203
1204        enum diff_symbol s = eds->s;
1205        const char *line = eds->line;
1206        int len = eds->len;
1207        unsigned flags = eds->flags;
1208
1209        switch (s) {
1210        case DIFF_SYMBOL_NO_LF_EOF:
1211                context = diff_get_color_opt(o, DIFF_CONTEXT);
1212                reset = diff_get_color_opt(o, DIFF_RESET);
1213                putc('\n', o->file);
1214                emit_line_0(o, context, reset, '\\',
1215                            nneof, strlen(nneof));
1216                break;
1217        case DIFF_SYMBOL_SUBMODULE_HEADER:
1218        case DIFF_SYMBOL_SUBMODULE_ERROR:
1219        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1220        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1221        case DIFF_SYMBOL_SUMMARY:
1222        case DIFF_SYMBOL_STATS_LINE:
1223        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1224        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1225                emit_line(o, "", "", line, len);
1226                break;
1227        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1228        case DIFF_SYMBOL_CONTEXT_MARKER:
1229                context = diff_get_color_opt(o, DIFF_CONTEXT);
1230                reset = diff_get_color_opt(o, DIFF_RESET);
1231                emit_line(o, context, reset, line, len);
1232                break;
1233        case DIFF_SYMBOL_SEPARATOR:
1234                fprintf(o->file, "%s%c",
1235                        diff_line_prefix(o),
1236                        o->line_termination);
1237                break;
1238        case DIFF_SYMBOL_CONTEXT:
1239                set = diff_get_color_opt(o, DIFF_CONTEXT);
1240                reset = diff_get_color_opt(o, DIFF_RESET);
1241                emit_line_ws_markup(o, set, reset, line, len, ' ',
1242                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1243                break;
1244        case DIFF_SYMBOL_PLUS:
1245                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1246                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1247                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1248                case DIFF_SYMBOL_MOVED_LINE |
1249                     DIFF_SYMBOL_MOVED_LINE_ALT |
1250                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1251                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1252                        break;
1253                case DIFF_SYMBOL_MOVED_LINE |
1254                     DIFF_SYMBOL_MOVED_LINE_ALT:
1255                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1256                        break;
1257                case DIFF_SYMBOL_MOVED_LINE |
1258                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1259                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1260                        break;
1261                case DIFF_SYMBOL_MOVED_LINE:
1262                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1263                        break;
1264                default:
1265                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1266                }
1267                reset = diff_get_color_opt(o, DIFF_RESET);
1268                emit_line_ws_markup(o, set, reset, line, len, '+',
1269                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1270                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1271                break;
1272        case DIFF_SYMBOL_MINUS:
1273                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1274                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1275                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1276                case DIFF_SYMBOL_MOVED_LINE |
1277                     DIFF_SYMBOL_MOVED_LINE_ALT |
1278                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1279                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1280                        break;
1281                case DIFF_SYMBOL_MOVED_LINE |
1282                     DIFF_SYMBOL_MOVED_LINE_ALT:
1283                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1284                        break;
1285                case DIFF_SYMBOL_MOVED_LINE |
1286                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1287                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1288                        break;
1289                case DIFF_SYMBOL_MOVED_LINE:
1290                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1291                        break;
1292                default:
1293                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1294                }
1295                reset = diff_get_color_opt(o, DIFF_RESET);
1296                emit_line_ws_markup(o, set, reset, line, len, '-',
1297                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1298                break;
1299        case DIFF_SYMBOL_WORDS_PORCELAIN:
1300                context = diff_get_color_opt(o, DIFF_CONTEXT);
1301                reset = diff_get_color_opt(o, DIFF_RESET);
1302                emit_line(o, context, reset, line, len);
1303                fputs("~\n", o->file);
1304                break;
1305        case DIFF_SYMBOL_WORDS:
1306                context = diff_get_color_opt(o, DIFF_CONTEXT);
1307                reset = diff_get_color_opt(o, DIFF_RESET);
1308                /*
1309                 * Skip the prefix character, if any.  With
1310                 * diff_suppress_blank_empty, there may be
1311                 * none.
1312                 */
1313                if (line[0] != '\n') {
1314                        line++;
1315                        len--;
1316                }
1317                emit_line(o, context, reset, line, len);
1318                break;
1319        case DIFF_SYMBOL_FILEPAIR_PLUS:
1320                meta = diff_get_color_opt(o, DIFF_METAINFO);
1321                reset = diff_get_color_opt(o, DIFF_RESET);
1322                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1323                        line, reset,
1324                        strchr(line, ' ') ? "\t" : "");
1325                break;
1326        case DIFF_SYMBOL_FILEPAIR_MINUS:
1327                meta = diff_get_color_opt(o, DIFF_METAINFO);
1328                reset = diff_get_color_opt(o, DIFF_RESET);
1329                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1330                        line, reset,
1331                        strchr(line, ' ') ? "\t" : "");
1332                break;
1333        case DIFF_SYMBOL_BINARY_FILES:
1334        case DIFF_SYMBOL_HEADER:
1335                fprintf(o->file, "%s", line);
1336                break;
1337        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1338                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1339                break;
1340        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1341                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1342                break;
1343        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1344                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1345                break;
1346        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1347                fputs(diff_line_prefix(o), o->file);
1348                fputc('\n', o->file);
1349                break;
1350        case DIFF_SYMBOL_REWRITE_DIFF:
1351                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1352                reset = diff_get_color_opt(o, DIFF_RESET);
1353                emit_line(o, fraginfo, reset, line, len);
1354                break;
1355        case DIFF_SYMBOL_SUBMODULE_ADD:
1356                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1357                reset = diff_get_color_opt(o, DIFF_RESET);
1358                emit_line(o, set, reset, line, len);
1359                break;
1360        case DIFF_SYMBOL_SUBMODULE_DEL:
1361                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1362                reset = diff_get_color_opt(o, DIFF_RESET);
1363                emit_line(o, set, reset, line, len);
1364                break;
1365        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1366                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1367                        diff_line_prefix(o), line);
1368                break;
1369        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1370                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1371                        diff_line_prefix(o), line);
1372                break;
1373        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1374                emit_line(o, "", "", " 0 files changed\n",
1375                          strlen(" 0 files changed\n"));
1376                break;
1377        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1378                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1379                break;
1380        case DIFF_SYMBOL_WORD_DIFF:
1381                fprintf(o->file, "%.*s", len, line);
1382                break;
1383        case DIFF_SYMBOL_STAT_SEP:
1384                fputs(o->stat_sep, o->file);
1385                break;
1386        default:
1387                BUG("unknown diff symbol");
1388        }
1389        strbuf_release(&sb);
1390}
1391
1392static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1393                             const char *line, int len, unsigned flags)
1394{
1395        struct emitted_diff_symbol e = {line, len, flags, s};
1396
1397        if (o->emitted_symbols)
1398                append_emitted_diff_symbol(o, &e);
1399        else
1400                emit_diff_symbol_from_struct(o, &e);
1401}
1402
1403void diff_emit_submodule_del(struct diff_options *o, const char *line)
1404{
1405        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1406}
1407
1408void diff_emit_submodule_add(struct diff_options *o, const char *line)
1409{
1410        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1411}
1412
1413void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1414{
1415        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1416                         path, strlen(path), 0);
1417}
1418
1419void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1420{
1421        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1422                         path, strlen(path), 0);
1423}
1424
1425void diff_emit_submodule_header(struct diff_options *o, const char *header)
1426{
1427        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1428                         header, strlen(header), 0);
1429}
1430
1431void diff_emit_submodule_error(struct diff_options *o, const char *err)
1432{
1433        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1434}
1435
1436void diff_emit_submodule_pipethrough(struct diff_options *o,
1437                                     const char *line, int len)
1438{
1439        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1440}
1441
1442static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1443{
1444        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1445              ecbdata->blank_at_eof_in_preimage &&
1446              ecbdata->blank_at_eof_in_postimage &&
1447              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1448              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1449                return 0;
1450        return ws_blank_line(line, len, ecbdata->ws_rule);
1451}
1452
1453static void emit_add_line(const char *reset,
1454                          struct emit_callback *ecbdata,
1455                          const char *line, int len)
1456{
1457        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1458        if (new_blank_line_at_eof(ecbdata, line, len))
1459                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1460
1461        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1462}
1463
1464static void emit_del_line(const char *reset,
1465                          struct emit_callback *ecbdata,
1466                          const char *line, int len)
1467{
1468        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1469        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1470}
1471
1472static void emit_context_line(const char *reset,
1473                              struct emit_callback *ecbdata,
1474                              const char *line, int len)
1475{
1476        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1477        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1478}
1479
1480static void emit_hunk_header(struct emit_callback *ecbdata,
1481                             const char *line, int len)
1482{
1483        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1484        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1485        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1486        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1487        static const char atat[2] = { '@', '@' };
1488        const char *cp, *ep;
1489        struct strbuf msgbuf = STRBUF_INIT;
1490        int org_len = len;
1491        int i = 1;
1492
1493        /*
1494         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1495         * it always is at least 10 bytes long.
1496         */
1497        if (len < 10 ||
1498            memcmp(line, atat, 2) ||
1499            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1500                emit_diff_symbol(ecbdata->opt,
1501                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1502                return;
1503        }
1504        ep += 2; /* skip over @@ */
1505
1506        /* The hunk header in fraginfo color */
1507        strbuf_addstr(&msgbuf, frag);
1508        strbuf_add(&msgbuf, line, ep - line);
1509        strbuf_addstr(&msgbuf, reset);
1510
1511        /*
1512         * trailing "\r\n"
1513         */
1514        for ( ; i < 3; i++)
1515                if (line[len - i] == '\r' || line[len - i] == '\n')
1516                        len--;
1517
1518        /* blank before the func header */
1519        for (cp = ep; ep - line < len; ep++)
1520                if (*ep != ' ' && *ep != '\t')
1521                        break;
1522        if (ep != cp) {
1523                strbuf_addstr(&msgbuf, context);
1524                strbuf_add(&msgbuf, cp, ep - cp);
1525                strbuf_addstr(&msgbuf, reset);
1526        }
1527
1528        if (ep < line + len) {
1529                strbuf_addstr(&msgbuf, func);
1530                strbuf_add(&msgbuf, ep, line + len - ep);
1531                strbuf_addstr(&msgbuf, reset);
1532        }
1533
1534        strbuf_add(&msgbuf, line + len, org_len - len);
1535        strbuf_complete_line(&msgbuf);
1536        emit_diff_symbol(ecbdata->opt,
1537                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1538        strbuf_release(&msgbuf);
1539}
1540
1541static struct diff_tempfile *claim_diff_tempfile(void) {
1542        int i;
1543        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1544                if (!diff_temp[i].name)
1545                        return diff_temp + i;
1546        BUG("diff is failing to clean up its tempfiles");
1547}
1548
1549static void remove_tempfile(void)
1550{
1551        int i;
1552        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1553                if (is_tempfile_active(diff_temp[i].tempfile))
1554                        delete_tempfile(&diff_temp[i].tempfile);
1555                diff_temp[i].name = NULL;
1556        }
1557}
1558
1559static void add_line_count(struct strbuf *out, int count)
1560{
1561        switch (count) {
1562        case 0:
1563                strbuf_addstr(out, "0,0");
1564                break;
1565        case 1:
1566                strbuf_addstr(out, "1");
1567                break;
1568        default:
1569                strbuf_addf(out, "1,%d", count);
1570                break;
1571        }
1572}
1573
1574static void emit_rewrite_lines(struct emit_callback *ecb,
1575                               int prefix, const char *data, int size)
1576{
1577        const char *endp = NULL;
1578        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1579
1580        while (0 < size) {
1581                int len;
1582
1583                endp = memchr(data, '\n', size);
1584                len = endp ? (endp - data + 1) : size;
1585                if (prefix != '+') {
1586                        ecb->lno_in_preimage++;
1587                        emit_del_line(reset, ecb, data, len);
1588                } else {
1589                        ecb->lno_in_postimage++;
1590                        emit_add_line(reset, ecb, data, len);
1591                }
1592                size -= len;
1593                data += len;
1594        }
1595        if (!endp)
1596                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1597}
1598
1599static void emit_rewrite_diff(const char *name_a,
1600                              const char *name_b,
1601                              struct diff_filespec *one,
1602                              struct diff_filespec *two,
1603                              struct userdiff_driver *textconv_one,
1604                              struct userdiff_driver *textconv_two,
1605                              struct diff_options *o)
1606{
1607        int lc_a, lc_b;
1608        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1609        const char *a_prefix, *b_prefix;
1610        char *data_one, *data_two;
1611        size_t size_one, size_two;
1612        struct emit_callback ecbdata;
1613        struct strbuf out = STRBUF_INIT;
1614
1615        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1616                a_prefix = o->b_prefix;
1617                b_prefix = o->a_prefix;
1618        } else {
1619                a_prefix = o->a_prefix;
1620                b_prefix = o->b_prefix;
1621        }
1622
1623        name_a += (*name_a == '/');
1624        name_b += (*name_b == '/');
1625
1626        strbuf_reset(&a_name);
1627        strbuf_reset(&b_name);
1628        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1629        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1630
1631        size_one = fill_textconv(textconv_one, one, &data_one);
1632        size_two = fill_textconv(textconv_two, two, &data_two);
1633
1634        memset(&ecbdata, 0, sizeof(ecbdata));
1635        ecbdata.color_diff = want_color(o->use_color);
1636        ecbdata.ws_rule = whitespace_rule(name_b);
1637        ecbdata.opt = o;
1638        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1639                mmfile_t mf1, mf2;
1640                mf1.ptr = (char *)data_one;
1641                mf2.ptr = (char *)data_two;
1642                mf1.size = size_one;
1643                mf2.size = size_two;
1644                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1645        }
1646        ecbdata.lno_in_preimage = 1;
1647        ecbdata.lno_in_postimage = 1;
1648
1649        lc_a = count_lines(data_one, size_one);
1650        lc_b = count_lines(data_two, size_two);
1651
1652        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1653                         a_name.buf, a_name.len, 0);
1654        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1655                         b_name.buf, b_name.len, 0);
1656
1657        strbuf_addstr(&out, "@@ -");
1658        if (!o->irreversible_delete)
1659                add_line_count(&out, lc_a);
1660        else
1661                strbuf_addstr(&out, "?,?");
1662        strbuf_addstr(&out, " +");
1663        add_line_count(&out, lc_b);
1664        strbuf_addstr(&out, " @@\n");
1665        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1666        strbuf_release(&out);
1667
1668        if (lc_a && !o->irreversible_delete)
1669                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1670        if (lc_b)
1671                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1672        if (textconv_one)
1673                free((char *)data_one);
1674        if (textconv_two)
1675                free((char *)data_two);
1676}
1677
1678struct diff_words_buffer {
1679        mmfile_t text;
1680        unsigned long alloc;
1681        struct diff_words_orig {
1682                const char *begin, *end;
1683        } *orig;
1684        int orig_nr, orig_alloc;
1685};
1686
1687static void diff_words_append(char *line, unsigned long len,
1688                struct diff_words_buffer *buffer)
1689{
1690        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1691        line++;
1692        len--;
1693        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1694        buffer->text.size += len;
1695        buffer->text.ptr[buffer->text.size] = '\0';
1696}
1697
1698struct diff_words_style_elem {
1699        const char *prefix;
1700        const char *suffix;
1701        const char *color; /* NULL; filled in by the setup code if
1702                            * color is enabled */
1703};
1704
1705struct diff_words_style {
1706        enum diff_words_type type;
1707        struct diff_words_style_elem new_word, old_word, ctx;
1708        const char *newline;
1709};
1710
1711static struct diff_words_style diff_words_styles[] = {
1712        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1713        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1714        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1715};
1716
1717struct diff_words_data {
1718        struct diff_words_buffer minus, plus;
1719        const char *current_plus;
1720        int last_minus;
1721        struct diff_options *opt;
1722        regex_t *word_regex;
1723        enum diff_words_type type;
1724        struct diff_words_style *style;
1725};
1726
1727static int fn_out_diff_words_write_helper(struct diff_options *o,
1728                                          struct diff_words_style_elem *st_el,
1729                                          const char *newline,
1730                                          size_t count, const char *buf)
1731{
1732        int print = 0;
1733        struct strbuf sb = STRBUF_INIT;
1734
1735        while (count) {
1736                char *p = memchr(buf, '\n', count);
1737                if (print)
1738                        strbuf_addstr(&sb, diff_line_prefix(o));
1739
1740                if (p != buf) {
1741                        const char *reset = st_el->color && *st_el->color ?
1742                                            GIT_COLOR_RESET : NULL;
1743                        if (st_el->color && *st_el->color)
1744                                strbuf_addstr(&sb, st_el->color);
1745                        strbuf_addstr(&sb, st_el->prefix);
1746                        strbuf_add(&sb, buf, p ? p - buf : count);
1747                        strbuf_addstr(&sb, st_el->suffix);
1748                        if (reset)
1749                                strbuf_addstr(&sb, reset);
1750                }
1751                if (!p)
1752                        goto out;
1753
1754                strbuf_addstr(&sb, newline);
1755                count -= p + 1 - buf;
1756                buf = p + 1;
1757                print = 1;
1758                if (count) {
1759                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1760                                         sb.buf, sb.len, 0);
1761                        strbuf_reset(&sb);
1762                }
1763        }
1764
1765out:
1766        if (sb.len)
1767                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1768                                 sb.buf, sb.len, 0);
1769        strbuf_release(&sb);
1770        return 0;
1771}
1772
1773/*
1774 * '--color-words' algorithm can be described as:
1775 *
1776 *   1. collect the minus/plus lines of a diff hunk, divided into
1777 *      minus-lines and plus-lines;
1778 *
1779 *   2. break both minus-lines and plus-lines into words and
1780 *      place them into two mmfile_t with one word for each line;
1781 *
1782 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1783 *
1784 * And for the common parts of the both file, we output the plus side text.
1785 * diff_words->current_plus is used to trace the current position of the plus file
1786 * which printed. diff_words->last_minus is used to trace the last minus word
1787 * printed.
1788 *
1789 * For '--graph' to work with '--color-words', we need to output the graph prefix
1790 * on each line of color words output. Generally, there are two conditions on
1791 * which we should output the prefix.
1792 *
1793 *   1. diff_words->last_minus == 0 &&
1794 *      diff_words->current_plus == diff_words->plus.text.ptr
1795 *
1796 *      that is: the plus text must start as a new line, and if there is no minus
1797 *      word printed, a graph prefix must be printed.
1798 *
1799 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1800 *      *(diff_words->current_plus - 1) == '\n'
1801 *
1802 *      that is: a graph prefix must be printed following a '\n'
1803 */
1804static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1805{
1806        if ((diff_words->last_minus == 0 &&
1807                diff_words->current_plus == diff_words->plus.text.ptr) ||
1808                (diff_words->current_plus > diff_words->plus.text.ptr &&
1809                *(diff_words->current_plus - 1) == '\n')) {
1810                return 1;
1811        } else {
1812                return 0;
1813        }
1814}
1815
1816static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1817{
1818        struct diff_words_data *diff_words = priv;
1819        struct diff_words_style *style = diff_words->style;
1820        int minus_first, minus_len, plus_first, plus_len;
1821        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1822        struct diff_options *opt = diff_words->opt;
1823        const char *line_prefix;
1824
1825        if (line[0] != '@' || parse_hunk_header(line, len,
1826                        &minus_first, &minus_len, &plus_first, &plus_len))
1827                return;
1828
1829        assert(opt);
1830        line_prefix = diff_line_prefix(opt);
1831
1832        /* POSIX requires that first be decremented by one if len == 0... */
1833        if (minus_len) {
1834                minus_begin = diff_words->minus.orig[minus_first].begin;
1835                minus_end =
1836                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1837        } else
1838                minus_begin = minus_end =
1839                        diff_words->minus.orig[minus_first].end;
1840
1841        if (plus_len) {
1842                plus_begin = diff_words->plus.orig[plus_first].begin;
1843                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1844        } else
1845                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1846
1847        if (color_words_output_graph_prefix(diff_words)) {
1848                fputs(line_prefix, diff_words->opt->file);
1849        }
1850        if (diff_words->current_plus != plus_begin) {
1851                fn_out_diff_words_write_helper(diff_words->opt,
1852                                &style->ctx, style->newline,
1853                                plus_begin - diff_words->current_plus,
1854                                diff_words->current_plus);
1855        }
1856        if (minus_begin != minus_end) {
1857                fn_out_diff_words_write_helper(diff_words->opt,
1858                                &style->old_word, style->newline,
1859                                minus_end - minus_begin, minus_begin);
1860        }
1861        if (plus_begin != plus_end) {
1862                fn_out_diff_words_write_helper(diff_words->opt,
1863                                &style->new_word, style->newline,
1864                                plus_end - plus_begin, plus_begin);
1865        }
1866
1867        diff_words->current_plus = plus_end;
1868        diff_words->last_minus = minus_first;
1869}
1870
1871/* This function starts looking at *begin, and returns 0 iff a word was found. */
1872static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1873                int *begin, int *end)
1874{
1875        if (word_regex && *begin < buffer->size) {
1876                regmatch_t match[1];
1877                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1878                                 buffer->size - *begin, 1, match, 0)) {
1879                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1880                                        '\n', match[0].rm_eo - match[0].rm_so);
1881                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1882                        *begin += match[0].rm_so;
1883                        return *begin >= *end;
1884                }
1885                return -1;
1886        }
1887
1888        /* find the next word */
1889        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1890                (*begin)++;
1891        if (*begin >= buffer->size)
1892                return -1;
1893
1894        /* find the end of the word */
1895        *end = *begin + 1;
1896        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1897                (*end)++;
1898
1899        return 0;
1900}
1901
1902/*
1903 * This function splits the words in buffer->text, stores the list with
1904 * newline separator into out, and saves the offsets of the original words
1905 * in buffer->orig.
1906 */
1907static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1908                regex_t *word_regex)
1909{
1910        int i, j;
1911        long alloc = 0;
1912
1913        out->size = 0;
1914        out->ptr = NULL;
1915
1916        /* fake an empty "0th" word */
1917        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1918        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1919        buffer->orig_nr = 1;
1920
1921        for (i = 0; i < buffer->text.size; i++) {
1922                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1923                        return;
1924
1925                /* store original boundaries */
1926                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1927                                buffer->orig_alloc);
1928                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1929                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1930                buffer->orig_nr++;
1931
1932                /* store one word */
1933                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1934                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1935                out->ptr[out->size + j - i] = '\n';
1936                out->size += j - i + 1;
1937
1938                i = j - 1;
1939        }
1940}
1941
1942/* this executes the word diff on the accumulated buffers */
1943static void diff_words_show(struct diff_words_data *diff_words)
1944{
1945        xpparam_t xpp;
1946        xdemitconf_t xecfg;
1947        mmfile_t minus, plus;
1948        struct diff_words_style *style = diff_words->style;
1949
1950        struct diff_options *opt = diff_words->opt;
1951        const char *line_prefix;
1952
1953        assert(opt);
1954        line_prefix = diff_line_prefix(opt);
1955
1956        /* special case: only removal */
1957        if (!diff_words->plus.text.size) {
1958                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1959                                 line_prefix, strlen(line_prefix), 0);
1960                fn_out_diff_words_write_helper(diff_words->opt,
1961                        &style->old_word, style->newline,
1962                        diff_words->minus.text.size,
1963                        diff_words->minus.text.ptr);
1964                diff_words->minus.text.size = 0;
1965                return;
1966        }
1967
1968        diff_words->current_plus = diff_words->plus.text.ptr;
1969        diff_words->last_minus = 0;
1970
1971        memset(&xpp, 0, sizeof(xpp));
1972        memset(&xecfg, 0, sizeof(xecfg));
1973        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1974        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1975        xpp.flags = 0;
1976        /* as only the hunk header will be parsed, we need a 0-context */
1977        xecfg.ctxlen = 0;
1978        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1979                          &xpp, &xecfg))
1980                die("unable to generate word diff");
1981        free(minus.ptr);
1982        free(plus.ptr);
1983        if (diff_words->current_plus != diff_words->plus.text.ptr +
1984                        diff_words->plus.text.size) {
1985                if (color_words_output_graph_prefix(diff_words))
1986                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1987                                         line_prefix, strlen(line_prefix), 0);
1988                fn_out_diff_words_write_helper(diff_words->opt,
1989                        &style->ctx, style->newline,
1990                        diff_words->plus.text.ptr + diff_words->plus.text.size
1991                        - diff_words->current_plus, diff_words->current_plus);
1992        }
1993        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1994}
1995
1996/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1997static void diff_words_flush(struct emit_callback *ecbdata)
1998{
1999        struct diff_options *wo = ecbdata->diff_words->opt;
2000
2001        if (ecbdata->diff_words->minus.text.size ||
2002            ecbdata->diff_words->plus.text.size)
2003                diff_words_show(ecbdata->diff_words);
2004
2005        if (wo->emitted_symbols) {
2006                struct diff_options *o = ecbdata->opt;
2007                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2008                int i;
2009
2010                /*
2011                 * NEEDSWORK:
2012                 * Instead of appending each, concat all words to a line?
2013                 */
2014                for (i = 0; i < wol->nr; i++)
2015                        append_emitted_diff_symbol(o, &wol->buf[i]);
2016
2017                for (i = 0; i < wol->nr; i++)
2018                        free((void *)wol->buf[i].line);
2019
2020                wol->nr = 0;
2021        }
2022}
2023
2024static void diff_filespec_load_driver(struct diff_filespec *one)
2025{
2026        /* Use already-loaded driver */
2027        if (one->driver)
2028                return;
2029
2030        if (S_ISREG(one->mode))
2031                one->driver = userdiff_find_by_path(one->path);
2032
2033        /* Fallback to default settings */
2034        if (!one->driver)
2035                one->driver = userdiff_find_by_name("default");
2036}
2037
2038static const char *userdiff_word_regex(struct diff_filespec *one)
2039{
2040        diff_filespec_load_driver(one);
2041        return one->driver->word_regex;
2042}
2043
2044static void init_diff_words_data(struct emit_callback *ecbdata,
2045                                 struct diff_options *orig_opts,
2046                                 struct diff_filespec *one,
2047                                 struct diff_filespec *two)
2048{
2049        int i;
2050        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2051        memcpy(o, orig_opts, sizeof(struct diff_options));
2052
2053        ecbdata->diff_words =
2054                xcalloc(1, sizeof(struct diff_words_data));
2055        ecbdata->diff_words->type = o->word_diff;
2056        ecbdata->diff_words->opt = o;
2057
2058        if (orig_opts->emitted_symbols)
2059                o->emitted_symbols =
2060                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2061
2062        if (!o->word_regex)
2063                o->word_regex = userdiff_word_regex(one);
2064        if (!o->word_regex)
2065                o->word_regex = userdiff_word_regex(two);
2066        if (!o->word_regex)
2067                o->word_regex = diff_word_regex_cfg;
2068        if (o->word_regex) {
2069                ecbdata->diff_words->word_regex = (regex_t *)
2070                        xmalloc(sizeof(regex_t));
2071                if (regcomp(ecbdata->diff_words->word_regex,
2072                            o->word_regex,
2073                            REG_EXTENDED | REG_NEWLINE))
2074                        die("invalid regular expression: %s",
2075                            o->word_regex);
2076        }
2077        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2078                if (o->word_diff == diff_words_styles[i].type) {
2079                        ecbdata->diff_words->style =
2080                                &diff_words_styles[i];
2081                        break;
2082                }
2083        }
2084        if (want_color(o->use_color)) {
2085                struct diff_words_style *st = ecbdata->diff_words->style;
2086                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2087                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2088                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2089        }
2090}
2091
2092static void free_diff_words_data(struct emit_callback *ecbdata)
2093{
2094        if (ecbdata->diff_words) {
2095                diff_words_flush(ecbdata);
2096                free (ecbdata->diff_words->opt->emitted_symbols);
2097                free (ecbdata->diff_words->opt);
2098                free (ecbdata->diff_words->minus.text.ptr);
2099                free (ecbdata->diff_words->minus.orig);
2100                free (ecbdata->diff_words->plus.text.ptr);
2101                free (ecbdata->diff_words->plus.orig);
2102                if (ecbdata->diff_words->word_regex) {
2103                        regfree(ecbdata->diff_words->word_regex);
2104                        free(ecbdata->diff_words->word_regex);
2105                }
2106                FREE_AND_NULL(ecbdata->diff_words);
2107        }
2108}
2109
2110const char *diff_get_color(int diff_use_color, enum color_diff ix)
2111{
2112        if (want_color(diff_use_color))
2113                return diff_colors[ix];
2114        return "";
2115}
2116
2117const char *diff_line_prefix(struct diff_options *opt)
2118{
2119        struct strbuf *msgbuf;
2120        if (!opt->output_prefix)
2121                return "";
2122
2123        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2124        return msgbuf->buf;
2125}
2126
2127static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
2128{
2129        const char *cp;
2130        unsigned long allot;
2131        size_t l = len;
2132
2133        cp = line;
2134        allot = l;
2135        while (0 < l) {
2136                (void) utf8_width(&cp, &l);
2137                if (!cp)
2138                        break; /* truncated in the middle? */
2139        }
2140        return allot - l;
2141}
2142
2143static void find_lno(const char *line, struct emit_callback *ecbdata)
2144{
2145        const char *p;
2146        ecbdata->lno_in_preimage = 0;
2147        ecbdata->lno_in_postimage = 0;
2148        p = strchr(line, '-');
2149        if (!p)
2150                return; /* cannot happen */
2151        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2152        p = strchr(p, '+');
2153        if (!p)
2154                return; /* cannot happen */
2155        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2156}
2157
2158static void fn_out_consume(void *priv, char *line, unsigned long len)
2159{
2160        struct emit_callback *ecbdata = priv;
2161        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2162        struct diff_options *o = ecbdata->opt;
2163
2164        o->found_changes = 1;
2165
2166        if (ecbdata->header) {
2167                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2168                                 ecbdata->header->buf, ecbdata->header->len, 0);
2169                strbuf_reset(ecbdata->header);
2170                ecbdata->header = NULL;
2171        }
2172
2173        if (ecbdata->label_path[0]) {
2174                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2175                                 ecbdata->label_path[0],
2176                                 strlen(ecbdata->label_path[0]), 0);
2177                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2178                                 ecbdata->label_path[1],
2179                                 strlen(ecbdata->label_path[1]), 0);
2180                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2181        }
2182
2183        if (diff_suppress_blank_empty
2184            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2185                line[0] = '\n';
2186                len = 1;
2187        }
2188
2189        if (line[0] == '@') {
2190                if (ecbdata->diff_words)
2191                        diff_words_flush(ecbdata);
2192                len = sane_truncate_line(ecbdata, line, len);
2193                find_lno(line, ecbdata);
2194                emit_hunk_header(ecbdata, line, len);
2195                return;
2196        }
2197
2198        if (ecbdata->diff_words) {
2199                enum diff_symbol s =
2200                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2201                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2202                if (line[0] == '-') {
2203                        diff_words_append(line, len,
2204                                          &ecbdata->diff_words->minus);
2205                        return;
2206                } else if (line[0] == '+') {
2207                        diff_words_append(line, len,
2208                                          &ecbdata->diff_words->plus);
2209                        return;
2210                } else if (starts_with(line, "\\ ")) {
2211                        /*
2212                         * Eat the "no newline at eof" marker as if we
2213                         * saw a "+" or "-" line with nothing on it,
2214                         * and return without diff_words_flush() to
2215                         * defer processing. If this is the end of
2216                         * preimage, more "+" lines may come after it.
2217                         */
2218                        return;
2219                }
2220                diff_words_flush(ecbdata);
2221                emit_diff_symbol(o, s, line, len, 0);
2222                return;
2223        }
2224
2225        switch (line[0]) {
2226        case '+':
2227                ecbdata->lno_in_postimage++;
2228                emit_add_line(reset, ecbdata, line + 1, len - 1);
2229                break;
2230        case '-':
2231                ecbdata->lno_in_preimage++;
2232                emit_del_line(reset, ecbdata, line + 1, len - 1);
2233                break;
2234        case ' ':
2235                ecbdata->lno_in_postimage++;
2236                ecbdata->lno_in_preimage++;
2237                emit_context_line(reset, ecbdata, line + 1, len - 1);
2238                break;
2239        default:
2240                /* incomplete line at the end */
2241                ecbdata->lno_in_preimage++;
2242                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2243                                 line, len, 0);
2244                break;
2245        }
2246}
2247
2248static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2249{
2250        const char *old_name = a;
2251        const char *new_name = b;
2252        int pfx_length, sfx_length;
2253        int pfx_adjust_for_slash;
2254        int len_a = strlen(a);
2255        int len_b = strlen(b);
2256        int a_midlen, b_midlen;
2257        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2258        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2259
2260        if (qlen_a || qlen_b) {
2261                quote_c_style(a, name, NULL, 0);
2262                strbuf_addstr(name, " => ");
2263                quote_c_style(b, name, NULL, 0);
2264                return;
2265        }
2266
2267        /* Find common prefix */
2268        pfx_length = 0;
2269        while (*old_name && *new_name && *old_name == *new_name) {
2270                if (*old_name == '/')
2271                        pfx_length = old_name - a + 1;
2272                old_name++;
2273                new_name++;
2274        }
2275
2276        /* Find common suffix */
2277        old_name = a + len_a;
2278        new_name = b + len_b;
2279        sfx_length = 0;
2280        /*
2281         * If there is a common prefix, it must end in a slash.  In
2282         * that case we let this loop run 1 into the prefix to see the
2283         * same slash.
2284         *
2285         * If there is no common prefix, we cannot do this as it would
2286         * underrun the input strings.
2287         */
2288        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2289        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2290               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2291               *old_name == *new_name) {
2292                if (*old_name == '/')
2293                        sfx_length = len_a - (old_name - a);
2294                old_name--;
2295                new_name--;
2296        }
2297
2298        /*
2299         * pfx{mid-a => mid-b}sfx
2300         * {pfx-a => pfx-b}sfx
2301         * pfx{sfx-a => sfx-b}
2302         * name-a => name-b
2303         */
2304        a_midlen = len_a - pfx_length - sfx_length;
2305        b_midlen = len_b - pfx_length - sfx_length;
2306        if (a_midlen < 0)
2307                a_midlen = 0;
2308        if (b_midlen < 0)
2309                b_midlen = 0;
2310
2311        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2312        if (pfx_length + sfx_length) {
2313                strbuf_add(name, a, pfx_length);
2314                strbuf_addch(name, '{');
2315        }
2316        strbuf_add(name, a + pfx_length, a_midlen);
2317        strbuf_addstr(name, " => ");
2318        strbuf_add(name, b + pfx_length, b_midlen);
2319        if (pfx_length + sfx_length) {
2320                strbuf_addch(name, '}');
2321                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2322        }
2323}
2324
2325struct diffstat_t {
2326        int nr;
2327        int alloc;
2328        struct diffstat_file {
2329                char *from_name;
2330                char *name;
2331                char *print_name;
2332                const char *comments;
2333                unsigned is_unmerged:1;
2334                unsigned is_binary:1;
2335                unsigned is_renamed:1;
2336                unsigned is_interesting:1;
2337                uintmax_t added, deleted;
2338        } **files;
2339};
2340
2341static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2342                                          const char *name_a,
2343                                          const char *name_b)
2344{
2345        struct diffstat_file *x;
2346        x = xcalloc(1, sizeof(*x));
2347        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2348        diffstat->files[diffstat->nr++] = x;
2349        if (name_b) {
2350                x->from_name = xstrdup(name_a);
2351                x->name = xstrdup(name_b);
2352                x->is_renamed = 1;
2353        }
2354        else {
2355                x->from_name = NULL;
2356                x->name = xstrdup(name_a);
2357        }
2358        return x;
2359}
2360
2361static void diffstat_consume(void *priv, char *line, unsigned long len)
2362{
2363        struct diffstat_t *diffstat = priv;
2364        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2365
2366        if (line[0] == '+')
2367                x->added++;
2368        else if (line[0] == '-')
2369                x->deleted++;
2370}
2371
2372const char mime_boundary_leader[] = "------------";
2373
2374static int scale_linear(int it, int width, int max_change)
2375{
2376        if (!it)
2377                return 0;
2378        /*
2379         * make sure that at least one '-' or '+' is printed if
2380         * there is any change to this path. The easiest way is to
2381         * scale linearly as if the alloted width is one column shorter
2382         * than it is, and then add 1 to the result.
2383         */
2384        return 1 + (it * (width - 1) / max_change);
2385}
2386
2387static void show_graph(struct strbuf *out, char ch, int cnt,
2388                       const char *set, const char *reset)
2389{
2390        if (cnt <= 0)
2391                return;
2392        strbuf_addstr(out, set);
2393        strbuf_addchars(out, ch, cnt);
2394        strbuf_addstr(out, reset);
2395}
2396
2397static void fill_print_name(struct diffstat_file *file)
2398{
2399        struct strbuf pname = STRBUF_INIT;
2400
2401        if (file->print_name)
2402                return;
2403
2404        if (file->is_renamed)
2405                pprint_rename(&pname, file->from_name, file->name);
2406        else
2407                quote_c_style(file->name, &pname, NULL, 0);
2408
2409        if (file->comments)
2410                strbuf_addf(&pname, " (%s)", file->comments);
2411
2412        file->print_name = strbuf_detach(&pname, NULL);
2413}
2414
2415static void print_stat_summary_inserts_deletes(struct diff_options *options,
2416                int files, int insertions, int deletions)
2417{
2418        struct strbuf sb = STRBUF_INIT;
2419
2420        if (!files) {
2421                assert(insertions == 0 && deletions == 0);
2422                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2423                                 NULL, 0, 0);
2424                return;
2425        }
2426
2427        strbuf_addf(&sb,
2428                    (files == 1) ? " %d file changed" : " %d files changed",
2429                    files);
2430
2431        /*
2432         * For binary diff, the caller may want to print "x files
2433         * changed" with insertions == 0 && deletions == 0.
2434         *
2435         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2436         * is probably less confusing (i.e skip over "2 files changed
2437         * but nothing about added/removed lines? Is this a bug in Git?").
2438         */
2439        if (insertions || deletions == 0) {
2440                strbuf_addf(&sb,
2441                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2442                            insertions);
2443        }
2444
2445        if (deletions || insertions == 0) {
2446                strbuf_addf(&sb,
2447                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2448                            deletions);
2449        }
2450        strbuf_addch(&sb, '\n');
2451        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2452                         sb.buf, sb.len, 0);
2453        strbuf_release(&sb);
2454}
2455
2456void print_stat_summary(FILE *fp, int files,
2457                        int insertions, int deletions)
2458{
2459        struct diff_options o;
2460        memset(&o, 0, sizeof(o));
2461        o.file = fp;
2462
2463        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2464}
2465
2466static void show_stats(struct diffstat_t *data, struct diff_options *options)
2467{
2468        int i, len, add, del, adds = 0, dels = 0;
2469        uintmax_t max_change = 0, max_len = 0;
2470        int total_files = data->nr, count;
2471        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2472        const char *reset, *add_c, *del_c;
2473        int extra_shown = 0;
2474        const char *line_prefix = diff_line_prefix(options);
2475        struct strbuf out = STRBUF_INIT;
2476
2477        if (data->nr == 0)
2478                return;
2479
2480        count = options->stat_count ? options->stat_count : data->nr;
2481
2482        reset = diff_get_color_opt(options, DIFF_RESET);
2483        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2484        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2485
2486        /*
2487         * Find the longest filename and max number of changes
2488         */
2489        for (i = 0; (i < count) && (i < data->nr); i++) {
2490                struct diffstat_file *file = data->files[i];
2491                uintmax_t change = file->added + file->deleted;
2492
2493                if (!file->is_interesting && (change == 0)) {
2494                        count++; /* not shown == room for one more */
2495                        continue;
2496                }
2497                fill_print_name(file);
2498                len = strlen(file->print_name);
2499                if (max_len < len)
2500                        max_len = len;
2501
2502                if (file->is_unmerged) {
2503                        /* "Unmerged" is 8 characters */
2504                        bin_width = bin_width < 8 ? 8 : bin_width;
2505                        continue;
2506                }
2507                if (file->is_binary) {
2508                        /* "Bin XXX -> YYY bytes" */
2509                        int w = 14 + decimal_width(file->added)
2510                                + decimal_width(file->deleted);
2511                        bin_width = bin_width < w ? w : bin_width;
2512                        /* Display change counts aligned with "Bin" */
2513                        number_width = 3;
2514                        continue;
2515                }
2516
2517                if (max_change < change)
2518                        max_change = change;
2519        }
2520        count = i; /* where we can stop scanning in data->files[] */
2521
2522        /*
2523         * We have width = stat_width or term_columns() columns total.
2524         * We want a maximum of min(max_len, stat_name_width) for the name part.
2525         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2526         * We also need 1 for " " and 4 + decimal_width(max_change)
2527         * for " | NNNN " and one the empty column at the end, altogether
2528         * 6 + decimal_width(max_change).
2529         *
2530         * If there's not enough space, we will use the smaller of
2531         * stat_name_width (if set) and 5/8*width for the filename,
2532         * and the rest for constant elements + graph part, but no more
2533         * than stat_graph_width for the graph part.
2534         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2535         * for the standard terminal size).
2536         *
2537         * In other words: stat_width limits the maximum width, and
2538         * stat_name_width fixes the maximum width of the filename,
2539         * and is also used to divide available columns if there
2540         * aren't enough.
2541         *
2542         * Binary files are displayed with "Bin XXX -> YYY bytes"
2543         * instead of the change count and graph. This part is treated
2544         * similarly to the graph part, except that it is not
2545         * "scaled". If total width is too small to accommodate the
2546         * guaranteed minimum width of the filename part and the
2547         * separators and this message, this message will "overflow"
2548         * making the line longer than the maximum width.
2549         */
2550
2551        if (options->stat_width == -1)
2552                width = term_columns() - strlen(line_prefix);
2553        else
2554                width = options->stat_width ? options->stat_width : 80;
2555        number_width = decimal_width(max_change) > number_width ?
2556                decimal_width(max_change) : number_width;
2557
2558        if (options->stat_graph_width == -1)
2559                options->stat_graph_width = diff_stat_graph_width;
2560
2561        /*
2562         * Guarantee 3/8*16==6 for the graph part
2563         * and 5/8*16==10 for the filename part
2564         */
2565        if (width < 16 + 6 + number_width)
2566                width = 16 + 6 + number_width;
2567
2568        /*
2569         * First assign sizes that are wanted, ignoring available width.
2570         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2571         * starting from "XXX" should fit in graph_width.
2572         */
2573        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2574        if (options->stat_graph_width &&
2575            options->stat_graph_width < graph_width)
2576                graph_width = options->stat_graph_width;
2577
2578        name_width = (options->stat_name_width > 0 &&
2579                      options->stat_name_width < max_len) ?
2580                options->stat_name_width : max_len;
2581
2582        /*
2583         * Adjust adjustable widths not to exceed maximum width
2584         */
2585        if (name_width + number_width + 6 + graph_width > width) {
2586                if (graph_width > width * 3/8 - number_width - 6) {
2587                        graph_width = width * 3/8 - number_width - 6;
2588                        if (graph_width < 6)
2589                                graph_width = 6;
2590                }
2591
2592                if (options->stat_graph_width &&
2593                    graph_width > options->stat_graph_width)
2594                        graph_width = options->stat_graph_width;
2595                if (name_width > width - number_width - 6 - graph_width)
2596                        name_width = width - number_width - 6 - graph_width;
2597                else
2598                        graph_width = width - number_width - 6 - name_width;
2599        }
2600
2601        /*
2602         * From here name_width is the width of the name area,
2603         * and graph_width is the width of the graph area.
2604         * max_change is used to scale graph properly.
2605         */
2606        for (i = 0; i < count; i++) {
2607                const char *prefix = "";
2608                struct diffstat_file *file = data->files[i];
2609                char *name = file->print_name;
2610                uintmax_t added = file->added;
2611                uintmax_t deleted = file->deleted;
2612                int name_len;
2613
2614                if (!file->is_interesting && (added + deleted == 0))
2615                        continue;
2616
2617                /*
2618                 * "scale" the filename
2619                 */
2620                len = name_width;
2621                name_len = strlen(name);
2622                if (name_width < name_len) {
2623                        char *slash;
2624                        prefix = "...";
2625                        len -= 3;
2626                        name += name_len - len;
2627                        slash = strchr(name, '/');
2628                        if (slash)
2629                                name = slash;
2630                }
2631
2632                if (file->is_binary) {
2633                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2634                        strbuf_addf(&out, " %*s", number_width, "Bin");
2635                        if (!added && !deleted) {
2636                                strbuf_addch(&out, '\n');
2637                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2638                                                 out.buf, out.len, 0);
2639                                strbuf_reset(&out);
2640                                continue;
2641                        }
2642                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2643                                del_c, deleted, reset);
2644                        strbuf_addstr(&out, " -> ");
2645                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2646                                add_c, added, reset);
2647                        strbuf_addstr(&out, " bytes\n");
2648                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2649                                         out.buf, out.len, 0);
2650                        strbuf_reset(&out);
2651                        continue;
2652                }
2653                else if (file->is_unmerged) {
2654                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2655                        strbuf_addstr(&out, " Unmerged\n");
2656                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2657                                         out.buf, out.len, 0);
2658                        strbuf_reset(&out);
2659                        continue;
2660                }
2661
2662                /*
2663                 * scale the add/delete
2664                 */
2665                add = added;
2666                del = deleted;
2667
2668                if (graph_width <= max_change) {
2669                        int total = scale_linear(add + del, graph_width, max_change);
2670                        if (total < 2 && add && del)
2671                                /* width >= 2 due to the sanity check */
2672                                total = 2;
2673                        if (add < del) {
2674                                add = scale_linear(add, graph_width, max_change);
2675                                del = total - add;
2676                        } else {
2677                                del = scale_linear(del, graph_width, max_change);
2678                                add = total - del;
2679                        }
2680                }
2681                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2682                strbuf_addf(&out, " %*"PRIuMAX"%s",
2683                        number_width, added + deleted,
2684                        added + deleted ? " " : "");
2685                show_graph(&out, '+', add, add_c, reset);
2686                show_graph(&out, '-', del, del_c, reset);
2687                strbuf_addch(&out, '\n');
2688                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2689                                 out.buf, out.len, 0);
2690                strbuf_reset(&out);
2691        }
2692
2693        for (i = 0; i < data->nr; i++) {
2694                struct diffstat_file *file = data->files[i];
2695                uintmax_t added = file->added;
2696                uintmax_t deleted = file->deleted;
2697
2698                if (file->is_unmerged ||
2699                    (!file->is_interesting && (added + deleted == 0))) {
2700                        total_files--;
2701                        continue;
2702                }
2703
2704                if (!file->is_binary) {
2705                        adds += added;
2706                        dels += deleted;
2707                }
2708                if (i < count)
2709                        continue;
2710                if (!extra_shown)
2711                        emit_diff_symbol(options,
2712                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2713                                         NULL, 0, 0);
2714                extra_shown = 1;
2715        }
2716
2717        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2718        strbuf_release(&out);
2719}
2720
2721static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2722{
2723        int i, adds = 0, dels = 0, total_files = data->nr;
2724
2725        if (data->nr == 0)
2726                return;
2727
2728        for (i = 0; i < data->nr; i++) {
2729                int added = data->files[i]->added;
2730                int deleted = data->files[i]->deleted;
2731
2732                if (data->files[i]->is_unmerged ||
2733                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2734                        total_files--;
2735                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2736                        adds += added;
2737                        dels += deleted;
2738                }
2739        }
2740        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2741}
2742
2743static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2744{
2745        int i;
2746
2747        if (data->nr == 0)
2748                return;
2749
2750        for (i = 0; i < data->nr; i++) {
2751                struct diffstat_file *file = data->files[i];
2752
2753                fprintf(options->file, "%s", diff_line_prefix(options));
2754
2755                if (file->is_binary)
2756                        fprintf(options->file, "-\t-\t");
2757                else
2758                        fprintf(options->file,
2759                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2760                                file->added, file->deleted);
2761                if (options->line_termination) {
2762                        fill_print_name(file);
2763                        if (!file->is_renamed)
2764                                write_name_quoted(file->name, options->file,
2765                                                  options->line_termination);
2766                        else {
2767                                fputs(file->print_name, options->file);
2768                                putc(options->line_termination, options->file);
2769                        }
2770                } else {
2771                        if (file->is_renamed) {
2772                                putc('\0', options->file);
2773                                write_name_quoted(file->from_name, options->file, '\0');
2774                        }
2775                        write_name_quoted(file->name, options->file, '\0');
2776                }
2777        }
2778}
2779
2780struct dirstat_file {
2781        const char *name;
2782        unsigned long changed;
2783};
2784
2785struct dirstat_dir {
2786        struct dirstat_file *files;
2787        int alloc, nr, permille, cumulative;
2788};
2789
2790static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2791                unsigned long changed, const char *base, int baselen)
2792{
2793        unsigned long sum_changes = 0;
2794        unsigned int sources = 0;
2795        const char *line_prefix = diff_line_prefix(opt);
2796
2797        while (dir->nr) {
2798                struct dirstat_file *f = dir->files;
2799                int namelen = strlen(f->name);
2800                unsigned long changes;
2801                char *slash;
2802
2803                if (namelen < baselen)
2804                        break;
2805                if (memcmp(f->name, base, baselen))
2806                        break;
2807                slash = strchr(f->name + baselen, '/');
2808                if (slash) {
2809                        int newbaselen = slash + 1 - f->name;
2810                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2811                        sources++;
2812                } else {
2813                        changes = f->changed;
2814                        dir->files++;
2815                        dir->nr--;
2816                        sources += 2;
2817                }
2818                sum_changes += changes;
2819        }
2820
2821        /*
2822         * We don't report dirstat's for
2823         *  - the top level
2824         *  - or cases where everything came from a single directory
2825         *    under this directory (sources == 1).
2826         */
2827        if (baselen && sources != 1) {
2828                if (sum_changes) {
2829                        int permille = sum_changes * 1000 / changed;
2830                        if (permille >= dir->permille) {
2831                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2832                                        permille / 10, permille % 10, baselen, base);
2833                                if (!dir->cumulative)
2834                                        return 0;
2835                        }
2836                }
2837        }
2838        return sum_changes;
2839}
2840
2841static int dirstat_compare(const void *_a, const void *_b)
2842{
2843        const struct dirstat_file *a = _a;
2844        const struct dirstat_file *b = _b;
2845        return strcmp(a->name, b->name);
2846}
2847
2848static void show_dirstat(struct diff_options *options)
2849{
2850        int i;
2851        unsigned long changed;
2852        struct dirstat_dir dir;
2853        struct diff_queue_struct *q = &diff_queued_diff;
2854
2855        dir.files = NULL;
2856        dir.alloc = 0;
2857        dir.nr = 0;
2858        dir.permille = options->dirstat_permille;
2859        dir.cumulative = options->flags.dirstat_cumulative;
2860
2861        changed = 0;
2862        for (i = 0; i < q->nr; i++) {
2863                struct diff_filepair *p = q->queue[i];
2864                const char *name;
2865                unsigned long copied, added, damage;
2866                int content_changed;
2867
2868                name = p->two->path ? p->two->path : p->one->path;
2869
2870                if (p->one->oid_valid && p->two->oid_valid)
2871                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
2872                else
2873                        content_changed = 1;
2874
2875                if (!content_changed) {
2876                        /*
2877                         * The SHA1 has not changed, so pre-/post-content is
2878                         * identical. We can therefore skip looking at the
2879                         * file contents altogether.
2880                         */
2881                        damage = 0;
2882                        goto found_damage;
2883                }
2884
2885                if (options->flags.dirstat_by_file) {
2886                        /*
2887                         * In --dirstat-by-file mode, we don't really need to
2888                         * look at the actual file contents at all.
2889                         * The fact that the SHA1 changed is enough for us to
2890                         * add this file to the list of results
2891                         * (with each file contributing equal damage).
2892                         */
2893                        damage = 1;
2894                        goto found_damage;
2895                }
2896
2897                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2898                        diff_populate_filespec(p->one, 0);
2899                        diff_populate_filespec(p->two, 0);
2900                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2901                                               &copied, &added);
2902                        diff_free_filespec_data(p->one);
2903                        diff_free_filespec_data(p->two);
2904                } else if (DIFF_FILE_VALID(p->one)) {
2905                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2906                        copied = added = 0;
2907                        diff_free_filespec_data(p->one);
2908                } else if (DIFF_FILE_VALID(p->two)) {
2909                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2910                        copied = 0;
2911                        added = p->two->size;
2912                        diff_free_filespec_data(p->two);
2913                } else
2914                        continue;
2915
2916                /*
2917                 * Original minus copied is the removed material,
2918                 * added is the new material.  They are both damages
2919                 * made to the preimage.
2920                 * If the resulting damage is zero, we know that
2921                 * diffcore_count_changes() considers the two entries to
2922                 * be identical, but since content_changed is true, we
2923                 * know that there must have been _some_ kind of change,
2924                 * so we force all entries to have damage > 0.
2925                 */
2926                damage = (p->one->size - copied) + added;
2927                if (!damage)
2928                        damage = 1;
2929
2930found_damage:
2931                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2932                dir.files[dir.nr].name = name;
2933                dir.files[dir.nr].changed = damage;
2934                changed += damage;
2935                dir.nr++;
2936        }
2937
2938        /* This can happen even with many files, if everything was renames */
2939        if (!changed)
2940                return;
2941
2942        /* Show all directories with more than x% of the changes */
2943        QSORT(dir.files, dir.nr, dirstat_compare);
2944        gather_dirstat(options, &dir, changed, "", 0);
2945}
2946
2947static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2948{
2949        int i;
2950        unsigned long changed;
2951        struct dirstat_dir dir;
2952
2953        if (data->nr == 0)
2954                return;
2955
2956        dir.files = NULL;
2957        dir.alloc = 0;
2958        dir.nr = 0;
2959        dir.permille = options->dirstat_permille;
2960        dir.cumulative = options->flags.dirstat_cumulative;
2961
2962        changed = 0;
2963        for (i = 0; i < data->nr; i++) {
2964                struct diffstat_file *file = data->files[i];
2965                unsigned long damage = file->added + file->deleted;
2966                if (file->is_binary)
2967                        /*
2968                         * binary files counts bytes, not lines. Must find some
2969                         * way to normalize binary bytes vs. textual lines.
2970                         * The following heuristic assumes that there are 64
2971                         * bytes per "line".
2972                         * This is stupid and ugly, but very cheap...
2973                         */
2974                        damage = DIV_ROUND_UP(damage, 64);
2975                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2976                dir.files[dir.nr].name = file->name;
2977                dir.files[dir.nr].changed = damage;
2978                changed += damage;
2979                dir.nr++;
2980        }
2981
2982        /* This can happen even with many files, if everything was renames */
2983        if (!changed)
2984                return;
2985
2986        /* Show all directories with more than x% of the changes */
2987        QSORT(dir.files, dir.nr, dirstat_compare);
2988        gather_dirstat(options, &dir, changed, "", 0);
2989}
2990
2991static void free_diffstat_info(struct diffstat_t *diffstat)
2992{
2993        int i;
2994        for (i = 0; i < diffstat->nr; i++) {
2995                struct diffstat_file *f = diffstat->files[i];
2996                free(f->print_name);
2997                free(f->name);
2998                free(f->from_name);
2999                free(f);
3000        }
3001        free(diffstat->files);
3002}
3003
3004struct checkdiff_t {
3005        const char *filename;
3006        int lineno;
3007        int conflict_marker_size;
3008        struct diff_options *o;
3009        unsigned ws_rule;
3010        unsigned status;
3011};
3012
3013static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3014{
3015        char firstchar;
3016        int cnt;
3017
3018        if (len < marker_size + 1)
3019                return 0;
3020        firstchar = line[0];
3021        switch (firstchar) {
3022        case '=': case '>': case '<': case '|':
3023                break;
3024        default:
3025                return 0;
3026        }
3027        for (cnt = 1; cnt < marker_size; cnt++)
3028                if (line[cnt] != firstchar)
3029                        return 0;
3030        /* line[1] thru line[marker_size-1] are same as firstchar */
3031        if (len < marker_size + 1 || !isspace(line[marker_size]))
3032                return 0;
3033        return 1;
3034}
3035
3036static void checkdiff_consume(void *priv, char *line, unsigned long len)
3037{
3038        struct checkdiff_t *data = priv;
3039        int marker_size = data->conflict_marker_size;
3040        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3041        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3042        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3043        char *err;
3044        const char *line_prefix;
3045
3046        assert(data->o);
3047        line_prefix = diff_line_prefix(data->o);
3048
3049        if (line[0] == '+') {
3050                unsigned bad;
3051                data->lineno++;
3052                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3053                        data->status |= 1;
3054                        fprintf(data->o->file,
3055                                "%s%s:%d: leftover conflict marker\n",
3056                                line_prefix, data->filename, data->lineno);
3057                }
3058                bad = ws_check(line + 1, len - 1, data->ws_rule);
3059                if (!bad)
3060                        return;
3061                data->status |= bad;
3062                err = whitespace_error_string(bad);
3063                fprintf(data->o->file, "%s%s:%d: %s.\n",
3064                        line_prefix, data->filename, data->lineno, err);
3065                free(err);
3066                emit_line(data->o, set, reset, line, 1);
3067                ws_check_emit(line + 1, len - 1, data->ws_rule,
3068                              data->o->file, set, reset, ws);
3069        } else if (line[0] == ' ') {
3070                data->lineno++;
3071        } else if (line[0] == '@') {
3072                char *plus = strchr(line, '+');
3073                if (plus)
3074                        data->lineno = strtol(plus, NULL, 10) - 1;
3075                else
3076                        die("invalid diff");
3077        }
3078}
3079
3080static unsigned char *deflate_it(char *data,
3081                                 unsigned long size,
3082                                 unsigned long *result_size)
3083{
3084        int bound;
3085        unsigned char *deflated;
3086        git_zstream stream;
3087
3088        git_deflate_init(&stream, zlib_compression_level);
3089        bound = git_deflate_bound(&stream, size);
3090        deflated = xmalloc(bound);
3091        stream.next_out = deflated;
3092        stream.avail_out = bound;
3093
3094        stream.next_in = (unsigned char *)data;
3095        stream.avail_in = size;
3096        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3097                ; /* nothing */
3098        git_deflate_end(&stream);
3099        *result_size = stream.total_out;
3100        return deflated;
3101}
3102
3103static void emit_binary_diff_body(struct diff_options *o,
3104                                  mmfile_t *one, mmfile_t *two)
3105{
3106        void *cp;
3107        void *delta;
3108        void *deflated;
3109        void *data;
3110        unsigned long orig_size;
3111        unsigned long delta_size;
3112        unsigned long deflate_size;
3113        unsigned long data_size;
3114
3115        /* We could do deflated delta, or we could do just deflated two,
3116         * whichever is smaller.
3117         */
3118        delta = NULL;
3119        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3120        if (one->size && two->size) {
3121                delta = diff_delta(one->ptr, one->size,
3122                                   two->ptr, two->size,
3123                                   &delta_size, deflate_size);
3124                if (delta) {
3125                        void *to_free = delta;
3126                        orig_size = delta_size;
3127                        delta = deflate_it(delta, delta_size, &delta_size);
3128                        free(to_free);
3129                }
3130        }
3131
3132        if (delta && delta_size < deflate_size) {
3133                char *s = xstrfmt("%lu", orig_size);
3134                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3135                                 s, strlen(s), 0);
3136                free(s);
3137                free(deflated);
3138                data = delta;
3139                data_size = delta_size;
3140        } else {
3141                char *s = xstrfmt("%lu", two->size);
3142                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3143                                 s, strlen(s), 0);
3144                free(s);
3145                free(delta);
3146                data = deflated;
3147                data_size = deflate_size;
3148        }
3149
3150        /* emit data encoded in base85 */
3151        cp = data;
3152        while (data_size) {
3153                int len;
3154                int bytes = (52 < data_size) ? 52 : data_size;
3155                char line[71];
3156                data_size -= bytes;
3157                if (bytes <= 26)
3158                        line[0] = bytes + 'A' - 1;
3159                else
3160                        line[0] = bytes - 26 + 'a' - 1;
3161                encode_85(line + 1, cp, bytes);
3162                cp = (char *) cp + bytes;
3163
3164                len = strlen(line);
3165                line[len++] = '\n';
3166                line[len] = '\0';
3167
3168                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3169                                 line, len, 0);
3170        }
3171        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3172        free(data);
3173}
3174
3175static void emit_binary_diff(struct diff_options *o,
3176                             mmfile_t *one, mmfile_t *two)
3177{
3178        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3179        emit_binary_diff_body(o, one, two);
3180        emit_binary_diff_body(o, two, one);
3181}
3182
3183int diff_filespec_is_binary(struct diff_filespec *one)
3184{
3185        if (one->is_binary == -1) {
3186                diff_filespec_load_driver(one);
3187                if (one->driver->binary != -1)
3188                        one->is_binary = one->driver->binary;
3189                else {
3190                        if (!one->data && DIFF_FILE_VALID(one))
3191                                diff_populate_filespec(one, CHECK_BINARY);
3192                        if (one->is_binary == -1 && one->data)
3193                                one->is_binary = buffer_is_binary(one->data,
3194                                                one->size);
3195                        if (one->is_binary == -1)
3196                                one->is_binary = 0;
3197                }
3198        }
3199        return one->is_binary;
3200}
3201
3202static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
3203{
3204        diff_filespec_load_driver(one);
3205        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3206}
3207
3208void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3209{
3210        if (!options->a_prefix)
3211                options->a_prefix = a;
3212        if (!options->b_prefix)
3213                options->b_prefix = b;
3214}
3215
3216struct userdiff_driver *get_textconv(struct diff_filespec *one)
3217{
3218        if (!DIFF_FILE_VALID(one))
3219                return NULL;
3220
3221        diff_filespec_load_driver(one);
3222        return userdiff_get_textconv(one->driver);
3223}
3224
3225static void builtin_diff(const char *name_a,
3226                         const char *name_b,
3227                         struct diff_filespec *one,
3228                         struct diff_filespec *two,
3229                         const char *xfrm_msg,
3230                         int must_show_header,
3231                         struct diff_options *o,
3232                         int complete_rewrite)
3233{
3234        mmfile_t mf1, mf2;
3235        const char *lbl[2];
3236        char *a_one, *b_two;
3237        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3238        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3239        const char *a_prefix, *b_prefix;
3240        struct userdiff_driver *textconv_one = NULL;
3241        struct userdiff_driver *textconv_two = NULL;
3242        struct strbuf header = STRBUF_INIT;
3243        const char *line_prefix = diff_line_prefix(o);
3244
3245        diff_set_mnemonic_prefix(o, "a/", "b/");
3246        if (o->flags.reverse_diff) {
3247                a_prefix = o->b_prefix;
3248                b_prefix = o->a_prefix;
3249        } else {
3250                a_prefix = o->a_prefix;
3251                b_prefix = o->b_prefix;
3252        }
3253
3254        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3255            (!one->mode || S_ISGITLINK(one->mode)) &&
3256            (!two->mode || S_ISGITLINK(two->mode))) {
3257                show_submodule_summary(o, one->path ? one->path : two->path,
3258                                &one->oid, &two->oid,
3259                                two->dirty_submodule);
3260                return;
3261        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3262                   (!one->mode || S_ISGITLINK(one->mode)) &&
3263                   (!two->mode || S_ISGITLINK(two->mode))) {
3264                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3265                                &one->oid, &two->oid,
3266                                two->dirty_submodule);
3267                return;
3268        }
3269
3270        if (o->flags.allow_textconv) {
3271                textconv_one = get_textconv(one);
3272                textconv_two = get_textconv(two);
3273        }
3274
3275        /* Never use a non-valid filename anywhere if at all possible */
3276        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3277        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3278
3279        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3280        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3281        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3282        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3283        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3284        if (lbl[0][0] == '/') {
3285                /* /dev/null */
3286                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3287                if (xfrm_msg)
3288                        strbuf_addstr(&header, xfrm_msg);
3289                must_show_header = 1;
3290        }
3291        else if (lbl[1][0] == '/') {
3292                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3293                if (xfrm_msg)
3294                        strbuf_addstr(&header, xfrm_msg);
3295                must_show_header = 1;
3296        }
3297        else {
3298                if (one->mode != two->mode) {
3299                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3300                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3301                        must_show_header = 1;
3302                }
3303                if (xfrm_msg)
3304                        strbuf_addstr(&header, xfrm_msg);
3305
3306                /*
3307                 * we do not run diff between different kind
3308                 * of objects.
3309                 */
3310                if ((one->mode ^ two->mode) & S_IFMT)
3311                        goto free_ab_and_return;
3312                if (complete_rewrite &&
3313                    (textconv_one || !diff_filespec_is_binary(one)) &&
3314                    (textconv_two || !diff_filespec_is_binary(two))) {
3315                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3316                                         header.buf, header.len, 0);
3317                        strbuf_reset(&header);
3318                        emit_rewrite_diff(name_a, name_b, one, two,
3319                                                textconv_one, textconv_two, o);
3320                        o->found_changes = 1;
3321                        goto free_ab_and_return;
3322                }
3323        }
3324
3325        if (o->irreversible_delete && lbl[1][0] == '/') {
3326                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3327                                 header.len, 0);
3328                strbuf_reset(&header);
3329                goto free_ab_and_return;
3330        } else if (!o->flags.text &&
3331            ( (!textconv_one && diff_filespec_is_binary(one)) ||
3332              (!textconv_two && diff_filespec_is_binary(two)) )) {
3333                struct strbuf sb = STRBUF_INIT;
3334                if (!one->data && !two->data &&
3335                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3336                    !o->flags.binary) {
3337                        if (!oidcmp(&one->oid, &two->oid)) {
3338                                if (must_show_header)
3339                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3340                                                         header.buf, header.len,
3341                                                         0);
3342                                goto free_ab_and_return;
3343                        }
3344                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3345                                         header.buf, header.len, 0);
3346                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3347                                    diff_line_prefix(o), lbl[0], lbl[1]);
3348                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3349                                         sb.buf, sb.len, 0);
3350                        strbuf_release(&sb);
3351                        goto free_ab_and_return;
3352                }
3353                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3354                        die("unable to read files to diff");
3355                /* Quite common confusing case */
3356                if (mf1.size == mf2.size &&
3357                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3358                        if (must_show_header)
3359                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3360                                                 header.buf, header.len, 0);
3361                        goto free_ab_and_return;
3362                }
3363                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3364                strbuf_reset(&header);
3365                if (o->flags.binary)
3366                        emit_binary_diff(o, &mf1, &mf2);
3367                else {
3368                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3369                                    diff_line_prefix(o), lbl[0], lbl[1]);
3370                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3371                                         sb.buf, sb.len, 0);
3372                        strbuf_release(&sb);
3373                }
3374                o->found_changes = 1;
3375        } else {
3376                /* Crazy xdl interfaces.. */
3377                const char *diffopts = getenv("GIT_DIFF_OPTS");
3378                const char *v;
3379                xpparam_t xpp;
3380                xdemitconf_t xecfg;
3381                struct emit_callback ecbdata;
3382                const struct userdiff_funcname *pe;
3383
3384                if (must_show_header) {
3385                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3386                                         header.buf, header.len, 0);
3387                        strbuf_reset(&header);
3388                }
3389
3390                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
3391                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
3392
3393                pe = diff_funcname_pattern(one);
3394                if (!pe)
3395                        pe = diff_funcname_pattern(two);
3396
3397                memset(&xpp, 0, sizeof(xpp));
3398                memset(&xecfg, 0, sizeof(xecfg));
3399                memset(&ecbdata, 0, sizeof(ecbdata));
3400                ecbdata.label_path = lbl;
3401                ecbdata.color_diff = want_color(o->use_color);
3402                ecbdata.ws_rule = whitespace_rule(name_b);
3403                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3404                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3405                ecbdata.opt = o;
3406                ecbdata.header = header.len ? &header : NULL;
3407                xpp.flags = o->xdl_opts;
3408                xpp.anchors = o->anchors;
3409                xpp.anchors_nr = o->anchors_nr;
3410                xecfg.ctxlen = o->context;
3411                xecfg.interhunkctxlen = o->interhunkcontext;
3412                xecfg.flags = XDL_EMIT_FUNCNAMES;
3413                if (o->flags.funccontext)
3414                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3415                if (pe)
3416                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3417                if (!diffopts)
3418                        ;
3419                else if (skip_prefix(diffopts, "--unified=", &v))
3420                        xecfg.ctxlen = strtoul(v, NULL, 10);
3421                else if (skip_prefix(diffopts, "-u", &v))
3422                        xecfg.ctxlen = strtoul(v, NULL, 10);
3423                if (o->word_diff)
3424                        init_diff_words_data(&ecbdata, o, one, two);
3425                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
3426                                  &xpp, &xecfg))
3427                        die("unable to generate diff for %s", one->path);
3428                if (o->word_diff)
3429                        free_diff_words_data(&ecbdata);
3430                if (textconv_one)
3431                        free(mf1.ptr);
3432                if (textconv_two)
3433                        free(mf2.ptr);
3434                xdiff_clear_find_func(&xecfg);
3435        }
3436
3437 free_ab_and_return:
3438        strbuf_release(&header);
3439        diff_free_filespec_data(one);
3440        diff_free_filespec_data(two);
3441        free(a_one);
3442        free(b_two);
3443        return;
3444}
3445
3446static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3447{
3448        if (!is_renamed) {
3449                if (p->status == DIFF_STATUS_ADDED) {
3450                        if (S_ISLNK(p->two->mode))
3451                                return "new +l";
3452                        else if ((p->two->mode & 0777) == 0755)
3453                                return "new +x";
3454                        else
3455                                return "new";
3456                } else if (p->status == DIFF_STATUS_DELETED)
3457                        return "gone";
3458        }
3459        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3460                return "mode -l";
3461        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3462                return "mode +l";
3463        else if ((p->one->mode & 0777) == 0644 &&
3464                 (p->two->mode & 0777) == 0755)
3465                return "mode +x";
3466        else if ((p->one->mode & 0777) == 0755 &&
3467                 (p->two->mode & 0777) == 0644)
3468                return "mode -x";
3469        return NULL;
3470}
3471
3472static void builtin_diffstat(const char *name_a, const char *name_b,
3473                             struct diff_filespec *one,
3474                             struct diff_filespec *two,
3475                             struct diffstat_t *diffstat,
3476                             struct diff_options *o,
3477                             struct diff_filepair *p)
3478{
3479        mmfile_t mf1, mf2;
3480        struct diffstat_file *data;
3481        int same_contents;
3482        int complete_rewrite = 0;
3483
3484        if (!DIFF_PAIR_UNMERGED(p)) {
3485                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3486                        complete_rewrite = 1;
3487        }
3488
3489        data = diffstat_add(diffstat, name_a, name_b);
3490        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3491        if (o->flags.stat_with_summary)
3492                data->comments = get_compact_summary(p, data->is_renamed);
3493
3494        if (!one || !two) {
3495                data->is_unmerged = 1;
3496                return;
3497        }
3498
3499        same_contents = !oidcmp(&one->oid, &two->oid);
3500
3501        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
3502                data->is_binary = 1;
3503                if (same_contents) {
3504                        data->added = 0;
3505                        data->deleted = 0;
3506                } else {
3507                        data->added = diff_filespec_size(two);
3508                        data->deleted = diff_filespec_size(one);
3509                }
3510        }
3511
3512        else if (complete_rewrite) {
3513                diff_populate_filespec(one, 0);
3514                diff_populate_filespec(two, 0);
3515                data->deleted = count_lines(one->data, one->size);
3516                data->added = count_lines(two->data, two->size);
3517        }
3518
3519        else if (!same_contents) {
3520                /* Crazy xdl interfaces.. */
3521                xpparam_t xpp;
3522                xdemitconf_t xecfg;
3523
3524                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3525                        die("unable to read files to diff");
3526
3527                memset(&xpp, 0, sizeof(xpp));
3528                memset(&xecfg, 0, sizeof(xecfg));
3529                xpp.flags = o->xdl_opts;
3530                xpp.anchors = o->anchors;
3531                xpp.anchors_nr = o->anchors_nr;
3532                xecfg.ctxlen = o->context;
3533                xecfg.interhunkctxlen = o->interhunkcontext;
3534                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
3535                                  &xpp, &xecfg))
3536                        die("unable to generate diffstat for %s", one->path);
3537        }
3538
3539        diff_free_filespec_data(one);
3540        diff_free_filespec_data(two);
3541}
3542
3543static void builtin_checkdiff(const char *name_a, const char *name_b,
3544                              const char *attr_path,
3545                              struct diff_filespec *one,
3546                              struct diff_filespec *two,
3547                              struct diff_options *o)
3548{
3549        mmfile_t mf1, mf2;
3550        struct checkdiff_t data;
3551
3552        if (!two)
3553                return;
3554
3555        memset(&data, 0, sizeof(data));
3556        data.filename = name_b ? name_b : name_a;
3557        data.lineno = 0;
3558        data.o = o;
3559        data.ws_rule = whitespace_rule(attr_path);
3560        data.conflict_marker_size = ll_merge_marker_size(attr_path);
3561
3562        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3563                die("unable to read files to diff");
3564
3565        /*
3566         * All the other codepaths check both sides, but not checking
3567         * the "old" side here is deliberate.  We are checking the newly
3568         * introduced changes, and as long as the "new" side is text, we
3569         * can and should check what it introduces.
3570         */
3571        if (diff_filespec_is_binary(two))
3572                goto free_and_return;
3573        else {
3574                /* Crazy xdl interfaces.. */
3575                xpparam_t xpp;
3576                xdemitconf_t xecfg;
3577
3578                memset(&xpp, 0, sizeof(xpp));
3579                memset(&xecfg, 0, sizeof(xecfg));
3580                xecfg.ctxlen = 1; /* at least one context line */
3581                xpp.flags = 0;
3582                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
3583                                  &xpp, &xecfg))
3584                        die("unable to generate checkdiff for %s", one->path);
3585
3586                if (data.ws_rule & WS_BLANK_AT_EOF) {
3587                        struct emit_callback ecbdata;
3588                        int blank_at_eof;
3589
3590                        ecbdata.ws_rule = data.ws_rule;
3591                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3592                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3593
3594                        if (blank_at_eof) {
3595                                static char *err;
3596                                if (!err)
3597                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3598                                fprintf(o->file, "%s:%d: %s.\n",
3599                                        data.filename, blank_at_eof, err);
3600                                data.status = 1; /* report errors */
3601                        }
3602                }
3603        }
3604 free_and_return:
3605        diff_free_filespec_data(one);
3606        diff_free_filespec_data(two);
3607        if (data.status)
3608                o->flags.check_failed = 1;
3609}
3610
3611struct diff_filespec *alloc_filespec(const char *path)
3612{
3613        struct diff_filespec *spec;
3614
3615        FLEXPTR_ALLOC_STR(spec, path, path);
3616        spec->count = 1;
3617        spec->is_binary = -1;
3618        return spec;
3619}
3620
3621void free_filespec(struct diff_filespec *spec)
3622{
3623        if (!--spec->count) {
3624                diff_free_filespec_data(spec);
3625                free(spec);
3626        }
3627}
3628
3629void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3630                   int oid_valid, unsigned short mode)
3631{
3632        if (mode) {
3633                spec->mode = canon_mode(mode);
3634                oidcpy(&spec->oid, oid);
3635                spec->oid_valid = oid_valid;
3636        }
3637}
3638
3639/*
3640 * Given a name and sha1 pair, if the index tells us the file in
3641 * the work tree has that object contents, return true, so that
3642 * prepare_temp_file() does not have to inflate and extract.
3643 */
3644static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
3645{
3646        const struct cache_entry *ce;
3647        struct stat st;
3648        int pos, len;
3649
3650        /*
3651         * We do not read the cache ourselves here, because the
3652         * benchmark with my previous version that always reads cache
3653         * shows that it makes things worse for diff-tree comparing
3654         * two linux-2.6 kernel trees in an already checked out work
3655         * tree.  This is because most diff-tree comparisons deal with
3656         * only a small number of files, while reading the cache is
3657         * expensive for a large project, and its cost outweighs the
3658         * savings we get by not inflating the object to a temporary
3659         * file.  Practically, this code only helps when we are used
3660         * by diff-cache --cached, which does read the cache before
3661         * calling us.
3662         */
3663        if (!active_cache)
3664                return 0;
3665
3666        /* We want to avoid the working directory if our caller
3667         * doesn't need the data in a normal file, this system
3668         * is rather slow with its stat/open/mmap/close syscalls,
3669         * and the object is contained in a pack file.  The pack
3670         * is probably already open and will be faster to obtain
3671         * the data through than the working directory.  Loose
3672         * objects however would tend to be slower as they need
3673         * to be individually opened and inflated.
3674         */
3675        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3676                return 0;
3677
3678        /*
3679         * Similarly, if we'd have to convert the file contents anyway, that
3680         * makes the optimization not worthwhile.
3681         */
3682        if (!want_file && would_convert_to_git(&the_index, name))
3683                return 0;
3684
3685        len = strlen(name);
3686        pos = cache_name_pos(name, len);
3687        if (pos < 0)
3688                return 0;
3689        ce = active_cache[pos];
3690
3691        /*
3692         * This is not the sha1 we are looking for, or
3693         * unreusable because it is not a regular file.
3694         */
3695        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3696                return 0;
3697
3698        /*
3699         * If ce is marked as "assume unchanged", there is no
3700         * guarantee that work tree matches what we are looking for.
3701         */
3702        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3703                return 0;
3704
3705        /*
3706         * If ce matches the file in the work tree, we can reuse it.
3707         */
3708        if (ce_uptodate(ce) ||
3709            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
3710                return 1;
3711
3712        return 0;
3713}
3714
3715static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3716{
3717        struct strbuf buf = STRBUF_INIT;
3718        char *dirty = "";
3719
3720        /* Are we looking at the work tree? */
3721        if (s->dirty_submodule)
3722                dirty = "-dirty";
3723
3724        strbuf_addf(&buf, "Subproject commit %s%s\n",
3725                    oid_to_hex(&s->oid), dirty);
3726        s->size = buf.len;
3727        if (size_only) {
3728                s->data = NULL;
3729                strbuf_release(&buf);
3730        } else {
3731                s->data = strbuf_detach(&buf, NULL);
3732                s->should_free = 1;
3733        }
3734        return 0;
3735}
3736
3737/*
3738 * While doing rename detection and pickaxe operation, we may need to
3739 * grab the data for the blob (or file) for our own in-core comparison.
3740 * diff_filespec has data and size fields for this purpose.
3741 */
3742int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
3743{
3744        int size_only = flags & CHECK_SIZE_ONLY;
3745        int err = 0;
3746        int conv_flags = global_conv_flags_eol;
3747        /*
3748         * demote FAIL to WARN to allow inspecting the situation
3749         * instead of refusing.
3750         */
3751        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3752                conv_flags = CONV_EOL_RNDTRP_WARN;
3753
3754        if (!DIFF_FILE_VALID(s))
3755                die("internal error: asking to populate invalid file.");
3756        if (S_ISDIR(s->mode))
3757                return -1;
3758
3759        if (s->data)
3760                return 0;
3761
3762        if (size_only && 0 < s->size)
3763                return 0;
3764
3765        if (S_ISGITLINK(s->mode))
3766                return diff_populate_gitlink(s, size_only);
3767
3768        if (!s->oid_valid ||
3769            reuse_worktree_file(s->path, &s->oid, 0)) {
3770                struct strbuf buf = STRBUF_INIT;
3771                struct stat st;
3772                int fd;
3773
3774                if (lstat(s->path, &st) < 0) {
3775                err_empty:
3776                        err = -1;
3777                empty:
3778                        s->data = (char *)"";
3779                        s->size = 0;
3780                        return err;
3781                }
3782                s->size = xsize_t(st.st_size);
3783                if (!s->size)
3784                        goto empty;
3785                if (S_ISLNK(st.st_mode)) {
3786                        struct strbuf sb = STRBUF_INIT;
3787
3788                        if (strbuf_readlink(&sb, s->path, s->size))
3789                                goto err_empty;
3790                        s->size = sb.len;
3791                        s->data = strbuf_detach(&sb, NULL);
3792                        s->should_free = 1;
3793                        return 0;
3794                }
3795
3796                /*
3797                 * Even if the caller would be happy with getting
3798                 * only the size, we cannot return early at this
3799                 * point if the path requires us to run the content
3800                 * conversion.
3801                 */
3802                if (size_only && !would_convert_to_git(&the_index, s->path))
3803                        return 0;
3804
3805                /*
3806                 * Note: this check uses xsize_t(st.st_size) that may
3807                 * not be the true size of the blob after it goes
3808                 * through convert_to_git().  This may not strictly be
3809                 * correct, but the whole point of big_file_threshold
3810                 * and is_binary check being that we want to avoid
3811                 * opening the file and inspecting the contents, this
3812                 * is probably fine.
3813                 */
3814                if ((flags & CHECK_BINARY) &&
3815                    s->size > big_file_threshold && s->is_binary == -1) {
3816                        s->is_binary = 1;
3817                        return 0;
3818                }
3819                fd = open(s->path, O_RDONLY);
3820                if (fd < 0)
3821                        goto err_empty;
3822                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3823                close(fd);
3824                s->should_munmap = 1;
3825
3826                /*
3827                 * Convert from working tree format to canonical git format
3828                 */
3829                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, conv_flags)) {
3830                        size_t size = 0;
3831                        munmap(s->data, s->size);
3832                        s->should_munmap = 0;
3833                        s->data = strbuf_detach(&buf, &size);
3834                        s->size = size;
3835                        s->should_free = 1;
3836                }
3837        }
3838        else {
3839                enum object_type type;
3840                if (size_only || (flags & CHECK_BINARY)) {
3841                        type = oid_object_info(the_repository, &s->oid,
3842                                               &s->size);
3843                        if (type < 0)
3844                                die("unable to read %s",
3845                                    oid_to_hex(&s->oid));
3846                        if (size_only)
3847                                return 0;
3848                        if (s->size > big_file_threshold && s->is_binary == -1) {
3849                                s->is_binary = 1;
3850                                return 0;
3851                        }
3852                }
3853                s->data = read_object_file(&s->oid, &type, &s->size);
3854                if (!s->data)
3855                        die("unable to read %s", oid_to_hex(&s->oid));
3856                s->should_free = 1;
3857        }
3858        return 0;
3859}
3860
3861void diff_free_filespec_blob(struct diff_filespec *s)
3862{
3863        if (s->should_free)
3864                free(s->data);
3865        else if (s->should_munmap)
3866                munmap(s->data, s->size);
3867
3868        if (s->should_free || s->should_munmap) {
3869                s->should_free = s->should_munmap = 0;
3870                s->data = NULL;
3871        }
3872}
3873
3874void diff_free_filespec_data(struct diff_filespec *s)
3875{
3876        diff_free_filespec_blob(s);
3877        FREE_AND_NULL(s->cnt_data);
3878}
3879
3880static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
3881                           void *blob,
3882                           unsigned long size,
3883                           const struct object_id *oid,
3884                           int mode)
3885{
3886        struct strbuf buf = STRBUF_INIT;
3887        struct strbuf tempfile = STRBUF_INIT;
3888        char *path_dup = xstrdup(path);
3889        const char *base = basename(path_dup);
3890
3891        /* Generate "XXXXXX_basename.ext" */
3892        strbuf_addstr(&tempfile, "XXXXXX_");
3893        strbuf_addstr(&tempfile, base);
3894
3895        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
3896        if (!temp->tempfile)
3897                die_errno("unable to create temp-file");
3898        if (convert_to_working_tree(path,
3899                        (const char *)blob, (size_t)size, &buf)) {
3900                blob = buf.buf;
3901                size = buf.len;
3902        }
3903        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
3904            close_tempfile_gently(temp->tempfile))
3905                die_errno("unable to write temp-file");
3906        temp->name = get_tempfile_path(temp->tempfile);
3907        oid_to_hex_r(temp->hex, oid);
3908        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3909        strbuf_release(&buf);
3910        strbuf_release(&tempfile);
3911        free(path_dup);
3912}
3913
3914static struct diff_tempfile *prepare_temp_file(const char *name,
3915                struct diff_filespec *one)
3916{
3917        struct diff_tempfile *temp = claim_diff_tempfile();
3918
3919        if (!DIFF_FILE_VALID(one)) {
3920        not_a_valid_file:
3921                /* A '-' entry produces this for file-2, and
3922                 * a '+' entry produces this for file-1.
3923                 */
3924                temp->name = "/dev/null";
3925                xsnprintf(temp->hex, sizeof(temp->hex), ".");
3926                xsnprintf(temp->mode, sizeof(temp->mode), ".");
3927                return temp;
3928        }
3929
3930        if (!S_ISGITLINK(one->mode) &&
3931            (!one->oid_valid ||
3932             reuse_worktree_file(name, &one->oid, 1))) {
3933                struct stat st;
3934                if (lstat(name, &st) < 0) {
3935                        if (errno == ENOENT)
3936                                goto not_a_valid_file;
3937                        die_errno("stat(%s)", name);
3938                }
3939                if (S_ISLNK(st.st_mode)) {
3940                        struct strbuf sb = STRBUF_INIT;
3941                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
3942                                die_errno("readlink(%s)", name);
3943                        prep_temp_blob(name, temp, sb.buf, sb.len,
3944                                       (one->oid_valid ?
3945                                        &one->oid : &null_oid),
3946                                       (one->oid_valid ?
3947                                        one->mode : S_IFLNK));
3948                        strbuf_release(&sb);
3949                }
3950                else {
3951                        /* we can borrow from the file in the work tree */
3952                        temp->name = name;
3953                        if (!one->oid_valid)
3954                                oid_to_hex_r(temp->hex, &null_oid);
3955                        else
3956                                oid_to_hex_r(temp->hex, &one->oid);
3957                        /* Even though we may sometimes borrow the
3958                         * contents from the work tree, we always want
3959                         * one->mode.  mode is trustworthy even when
3960                         * !(one->oid_valid), as long as
3961                         * DIFF_FILE_VALID(one).
3962                         */
3963                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
3964                }
3965                return temp;
3966        }
3967        else {
3968                if (diff_populate_filespec(one, 0))
3969                        die("cannot read data blob for %s", one->path);
3970                prep_temp_blob(name, temp, one->data, one->size,
3971                               &one->oid, one->mode);
3972        }
3973        return temp;
3974}
3975
3976static void add_external_diff_name(struct argv_array *argv,
3977                                   const char *name,
3978                                   struct diff_filespec *df)
3979{
3980        struct diff_tempfile *temp = prepare_temp_file(name, df);
3981        argv_array_push(argv, temp->name);
3982        argv_array_push(argv, temp->hex);
3983        argv_array_push(argv, temp->mode);
3984}
3985
3986/* An external diff command takes:
3987 *
3988 * diff-cmd name infile1 infile1-sha1 infile1-mode \
3989 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
3990 *
3991 */
3992static void run_external_diff(const char *pgm,
3993                              const char *name,
3994                              const char *other,
3995                              struct diff_filespec *one,
3996                              struct diff_filespec *two,
3997                              const char *xfrm_msg,
3998                              int complete_rewrite,
3999                              struct diff_options *o)
4000{
4001        struct argv_array argv = ARGV_ARRAY_INIT;
4002        struct argv_array env = ARGV_ARRAY_INIT;
4003        struct diff_queue_struct *q = &diff_queued_diff;
4004
4005        argv_array_push(&argv, pgm);
4006        argv_array_push(&argv, name);
4007
4008        if (one && two) {
4009                add_external_diff_name(&argv, name, one);
4010                if (!other)
4011                        add_external_diff_name(&argv, name, two);
4012                else {
4013                        add_external_diff_name(&argv, other, two);
4014                        argv_array_push(&argv, other);
4015                        argv_array_push(&argv, xfrm_msg);
4016                }
4017        }
4018
4019        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4020        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4021
4022        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4023                die(_("external diff died, stopping at %s"), name);
4024
4025        remove_tempfile();
4026        argv_array_clear(&argv);
4027        argv_array_clear(&env);
4028}
4029
4030static int similarity_index(struct diff_filepair *p)
4031{
4032        return p->score * 100 / MAX_SCORE;
4033}
4034
4035static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4036{
4037        if (startup_info->have_repository)
4038                return find_unique_abbrev(oid, abbrev);
4039        else {
4040                char *hex = oid_to_hex(oid);
4041                if (abbrev < 0)
4042                        abbrev = FALLBACK_DEFAULT_ABBREV;
4043                if (abbrev > the_hash_algo->hexsz)
4044                        BUG("oid abbreviation out of range: %d", abbrev);
4045                if (abbrev)
4046                        hex[abbrev] = '\0';
4047                return hex;
4048        }
4049}
4050
4051static void fill_metainfo(struct strbuf *msg,
4052                          const char *name,
4053                          const char *other,
4054                          struct diff_filespec *one,
4055                          struct diff_filespec *two,
4056                          struct diff_options *o,
4057                          struct diff_filepair *p,
4058                          int *must_show_header,
4059                          int use_color)
4060{
4061        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4062        const char *reset = diff_get_color(use_color, DIFF_RESET);
4063        const char *line_prefix = diff_line_prefix(o);
4064
4065        *must_show_header = 1;
4066        strbuf_init(msg, PATH_MAX * 2 + 300);
4067        switch (p->status) {
4068        case DIFF_STATUS_COPIED:
4069                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4070                            line_prefix, set, similarity_index(p));
4071                strbuf_addf(msg, "%s\n%s%scopy from ",
4072                            reset,  line_prefix, set);
4073                quote_c_style(name, msg, NULL, 0);
4074                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4075                quote_c_style(other, msg, NULL, 0);
4076                strbuf_addf(msg, "%s\n", reset);
4077                break;
4078        case DIFF_STATUS_RENAMED:
4079                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4080                            line_prefix, set, similarity_index(p));
4081                strbuf_addf(msg, "%s\n%s%srename from ",
4082                            reset, line_prefix, set);
4083                quote_c_style(name, msg, NULL, 0);
4084                strbuf_addf(msg, "%s\n%s%srename to ",
4085                            reset, line_prefix, set);
4086                quote_c_style(other, msg, NULL, 0);
4087                strbuf_addf(msg, "%s\n", reset);
4088                break;
4089        case DIFF_STATUS_MODIFIED:
4090                if (p->score) {
4091                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4092                                    line_prefix,
4093                                    set, similarity_index(p), reset);
4094                        break;
4095                }
4096                /* fallthru */
4097        default:
4098                *must_show_header = 0;
4099        }
4100        if (one && two && oidcmp(&one->oid, &two->oid)) {
4101                const unsigned hexsz = the_hash_algo->hexsz;
4102                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4103
4104                if (o->flags.binary) {
4105                        mmfile_t mf;
4106                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
4107                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
4108                                abbrev = hexsz;
4109                }
4110                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4111                            diff_abbrev_oid(&one->oid, abbrev),
4112                            diff_abbrev_oid(&two->oid, abbrev));
4113                if (one->mode == two->mode)
4114                        strbuf_addf(msg, " %06o", one->mode);
4115                strbuf_addf(msg, "%s\n", reset);
4116        }
4117}
4118
4119static void run_diff_cmd(const char *pgm,
4120                         const char *name,
4121                         const char *other,
4122                         const char *attr_path,
4123                         struct diff_filespec *one,
4124                         struct diff_filespec *two,
4125                         struct strbuf *msg,
4126                         struct diff_options *o,
4127                         struct diff_filepair *p)
4128{
4129        const char *xfrm_msg = NULL;
4130        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4131        int must_show_header = 0;
4132
4133
4134        if (o->flags.allow_external) {
4135                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
4136                if (drv && drv->external)
4137                        pgm = drv->external;
4138        }
4139
4140        if (msg) {
4141                /*
4142                 * don't use colors when the header is intended for an
4143                 * external diff driver
4144                 */
4145                fill_metainfo(msg, name, other, one, two, o, p,
4146                              &must_show_header,
4147                              want_color(o->use_color) && !pgm);
4148                xfrm_msg = msg->len ? msg->buf : NULL;
4149        }
4150
4151        if (pgm) {
4152                run_external_diff(pgm, name, other, one, two, xfrm_msg,
4153                                  complete_rewrite, o);
4154                return;
4155        }
4156        if (one && two)
4157                builtin_diff(name, other ? other : name,
4158                             one, two, xfrm_msg, must_show_header,
4159                             o, complete_rewrite);
4160        else
4161                fprintf(o->file, "* Unmerged path %s\n", name);
4162}
4163
4164static void diff_fill_oid_info(struct diff_filespec *one)
4165{
4166        if (DIFF_FILE_VALID(one)) {
4167                if (!one->oid_valid) {
4168                        struct stat st;
4169                        if (one->is_stdin) {
4170                                oidclr(&one->oid);
4171                                return;
4172                        }
4173                        if (lstat(one->path, &st) < 0)
4174                                die_errno("stat '%s'", one->path);
4175                        if (index_path(&one->oid, one->path, &st, 0))
4176                                die("cannot hash %s", one->path);
4177                }
4178        }
4179        else
4180                oidclr(&one->oid);
4181}
4182
4183static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4184{
4185        /* Strip the prefix but do not molest /dev/null and absolute paths */
4186        if (*namep && **namep != '/') {
4187                *namep += prefix_length;
4188                if (**namep == '/')
4189                        ++*namep;
4190        }
4191        if (*otherp && **otherp != '/') {
4192                *otherp += prefix_length;
4193                if (**otherp == '/')
4194                        ++*otherp;
4195        }
4196}
4197
4198static void run_diff(struct diff_filepair *p, struct diff_options *o)
4199{
4200        const char *pgm = external_diff();
4201        struct strbuf msg;
4202        struct diff_filespec *one = p->one;
4203        struct diff_filespec *two = p->two;
4204        const char *name;
4205        const char *other;
4206        const char *attr_path;
4207
4208        name  = one->path;
4209        other = (strcmp(name, two->path) ? two->path : NULL);
4210        attr_path = name;
4211        if (o->prefix_length)
4212                strip_prefix(o->prefix_length, &name, &other);
4213
4214        if (!o->flags.allow_external)
4215                pgm = NULL;
4216
4217        if (DIFF_PAIR_UNMERGED(p)) {
4218                run_diff_cmd(pgm, name, NULL, attr_path,
4219                             NULL, NULL, NULL, o, p);
4220                return;
4221        }
4222
4223        diff_fill_oid_info(one);
4224        diff_fill_oid_info(two);
4225
4226        if (!pgm &&
4227            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4228            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4229                /*
4230                 * a filepair that changes between file and symlink
4231                 * needs to be split into deletion and creation.
4232                 */
4233                struct diff_filespec *null = alloc_filespec(two->path);
4234                run_diff_cmd(NULL, name, other, attr_path,
4235                             one, null, &msg, o, p);
4236                free(null);
4237                strbuf_release(&msg);
4238
4239                null = alloc_filespec(one->path);
4240                run_diff_cmd(NULL, name, other, attr_path,
4241                             null, two, &msg, o, p);
4242                free(null);
4243        }
4244        else
4245                run_diff_cmd(pgm, name, other, attr_path,
4246                             one, two, &msg, o, p);
4247
4248        strbuf_release(&msg);
4249}
4250
4251static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4252                         struct diffstat_t *diffstat)
4253{
4254        const char *name;
4255        const char *other;
4256
4257        if (DIFF_PAIR_UNMERGED(p)) {
4258                /* unmerged */
4259                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
4260                return;
4261        }
4262
4263        name = p->one->path;
4264        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4265
4266        if (o->prefix_length)
4267                strip_prefix(o->prefix_length, &name, &other);
4268
4269        diff_fill_oid_info(p->one);
4270        diff_fill_oid_info(p->two);
4271
4272        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
4273}
4274
4275static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4276{
4277        const char *name;
4278        const char *other;
4279        const char *attr_path;
4280
4281        if (DIFF_PAIR_UNMERGED(p)) {
4282                /* unmerged */
4283                return;
4284        }
4285
4286        name = p->one->path;
4287        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4288        attr_path = other ? other : name;
4289
4290        if (o->prefix_length)
4291                strip_prefix(o->prefix_length, &name, &other);
4292
4293        diff_fill_oid_info(p->one);
4294        diff_fill_oid_info(p->two);
4295
4296        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4297}
4298
4299void diff_setup(struct diff_options *options)
4300{
4301        memcpy(options, &default_diff_options, sizeof(*options));
4302
4303        options->file = stdout;
4304
4305        options->abbrev = DEFAULT_ABBREV;
4306        options->line_termination = '\n';
4307        options->break_opt = -1;
4308        options->rename_limit = -1;
4309        options->dirstat_permille = diff_dirstat_permille_default;
4310        options->context = diff_context_default;
4311        options->interhunkcontext = diff_interhunk_context_default;
4312        options->ws_error_highlight = ws_error_highlight_default;
4313        options->flags.rename_empty = 1;
4314        options->objfind = NULL;
4315
4316        /* pathchange left =NULL by default */
4317        options->change = diff_change;
4318        options->add_remove = diff_addremove;
4319        options->use_color = diff_use_color_default;
4320        options->detect_rename = diff_detect_rename_default;
4321        options->xdl_opts |= diff_algorithm;
4322        if (diff_indent_heuristic)
4323                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4324
4325        options->orderfile = diff_order_file_cfg;
4326
4327        if (diff_no_prefix) {
4328                options->a_prefix = options->b_prefix = "";
4329        } else if (!diff_mnemonic_prefix) {
4330                options->a_prefix = "a/";
4331                options->b_prefix = "b/";
4332        }
4333
4334        options->color_moved = diff_color_moved_default;
4335        options->color_moved_ws_handling = diff_color_moved_ws_default;
4336}
4337
4338void diff_setup_done(struct diff_options *options)
4339{
4340        unsigned check_mask = DIFF_FORMAT_NAME |
4341                              DIFF_FORMAT_NAME_STATUS |
4342                              DIFF_FORMAT_CHECKDIFF |
4343                              DIFF_FORMAT_NO_OUTPUT;
4344        /*
4345         * This must be signed because we're comparing against a potentially
4346         * negative value.
4347         */
4348        const int hexsz = the_hash_algo->hexsz;
4349
4350        if (options->set_default)
4351                options->set_default(options);
4352
4353        if (HAS_MULTI_BITS(options->output_format & check_mask))
4354                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4355
4356        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4357                die(_("-G, -S and --find-object are mutually exclusive"));
4358
4359        /*
4360         * Most of the time we can say "there are changes"
4361         * only by checking if there are changed paths, but
4362         * --ignore-whitespace* options force us to look
4363         * inside contents.
4364         */
4365
4366        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4367                options->flags.diff_from_contents = 1;
4368        else
4369                options->flags.diff_from_contents = 0;
4370
4371        if (options->flags.find_copies_harder)
4372                options->detect_rename = DIFF_DETECT_COPY;
4373
4374        if (!options->flags.relative_name)
4375                options->prefix = NULL;
4376        if (options->prefix)
4377                options->prefix_length = strlen(options->prefix);
4378        else
4379                options->prefix_length = 0;
4380
4381        if (options->output_format & (DIFF_FORMAT_NAME |
4382                                      DIFF_FORMAT_NAME_STATUS |
4383                                      DIFF_FORMAT_CHECKDIFF |
4384                                      DIFF_FORMAT_NO_OUTPUT))
4385                options->output_format &= ~(DIFF_FORMAT_RAW |
4386                                            DIFF_FORMAT_NUMSTAT |
4387                                            DIFF_FORMAT_DIFFSTAT |
4388                                            DIFF_FORMAT_SHORTSTAT |
4389                                            DIFF_FORMAT_DIRSTAT |
4390                                            DIFF_FORMAT_SUMMARY |
4391                                            DIFF_FORMAT_PATCH);
4392
4393        /*
4394         * These cases always need recursive; we do not drop caller-supplied
4395         * recursive bits for other formats here.
4396         */
4397        if (options->output_format & (DIFF_FORMAT_PATCH |
4398                                      DIFF_FORMAT_NUMSTAT |
4399                                      DIFF_FORMAT_DIFFSTAT |
4400                                      DIFF_FORMAT_SHORTSTAT |
4401                                      DIFF_FORMAT_DIRSTAT |
4402                                      DIFF_FORMAT_SUMMARY |
4403                                      DIFF_FORMAT_CHECKDIFF))
4404                options->flags.recursive = 1;
4405        /*
4406         * Also pickaxe would not work very well if you do not say recursive
4407         */
4408        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4409                options->flags.recursive = 1;
4410        /*
4411         * When patches are generated, submodules diffed against the work tree
4412         * must be checked for dirtiness too so it can be shown in the output
4413         */
4414        if (options->output_format & DIFF_FORMAT_PATCH)
4415                options->flags.dirty_submodules = 1;
4416
4417        if (options->detect_rename && options->rename_limit < 0)
4418                options->rename_limit = diff_rename_limit_default;
4419        if (options->setup & DIFF_SETUP_USE_CACHE) {
4420                if (!active_cache)
4421                        /* read-cache does not die even when it fails
4422                         * so it is safe for us to do this here.  Also
4423                         * it does not smudge active_cache or active_nr
4424                         * when it fails, so we do not have to worry about
4425                         * cleaning it up ourselves either.
4426                         */
4427                        read_cache();
4428        }
4429        if (hexsz < options->abbrev)
4430                options->abbrev = hexsz; /* full */
4431
4432        /*
4433         * It does not make sense to show the first hit we happened
4434         * to have found.  It does not make sense not to return with
4435         * exit code in such a case either.
4436         */
4437        if (options->flags.quick) {
4438                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4439                options->flags.exit_with_status = 1;
4440        }
4441
4442        options->diff_path_counter = 0;
4443
4444        if (options->flags.follow_renames && options->pathspec.nr != 1)
4445                die(_("--follow requires exactly one pathspec"));
4446
4447        if (!options->use_color || external_diff())
4448                options->color_moved = 0;
4449}
4450
4451static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4452{
4453        char c, *eq;
4454        int len;
4455
4456        if (*arg != '-')
4457                return 0;
4458        c = *++arg;
4459        if (!c)
4460                return 0;
4461        if (c == arg_short) {
4462                c = *++arg;
4463                if (!c)
4464                        return 1;
4465                if (val && isdigit(c)) {
4466                        char *end;
4467                        int n = strtoul(arg, &end, 10);
4468                        if (*end)
4469                                return 0;
4470                        *val = n;
4471                        return 1;
4472                }
4473                return 0;
4474        }
4475        if (c != '-')
4476                return 0;
4477        arg++;
4478        eq = strchrnul(arg, '=');
4479        len = eq - arg;
4480        if (!len || strncmp(arg, arg_long, len))
4481                return 0;
4482        if (*eq) {
4483                int n;
4484                char *end;
4485                if (!isdigit(*++eq))
4486                        return 0;
4487                n = strtoul(eq, &end, 10);
4488                if (*end)
4489                        return 0;
4490                *val = n;
4491        }
4492        return 1;
4493}
4494
4495static int diff_scoreopt_parse(const char *opt);
4496
4497static inline int short_opt(char opt, const char **argv,
4498                            const char **optarg)
4499{
4500        const char *arg = argv[0];
4501        if (arg[0] != '-' || arg[1] != opt)
4502                return 0;
4503        if (arg[2] != '\0') {
4504                *optarg = arg + 2;
4505                return 1;
4506        }
4507        if (!argv[1])
4508                die("Option '%c' requires a value", opt);
4509        *optarg = argv[1];
4510        return 2;
4511}
4512
4513int parse_long_opt(const char *opt, const char **argv,
4514                   const char **optarg)
4515{
4516        const char *arg = argv[0];
4517        if (!skip_prefix(arg, "--", &arg))
4518                return 0;
4519        if (!skip_prefix(arg, opt, &arg))
4520                return 0;
4521        if (*arg == '=') { /* stuck form: --option=value */
4522                *optarg = arg + 1;
4523                return 1;
4524        }
4525        if (*arg != '\0')
4526                return 0;
4527        /* separate form: --option value */
4528        if (!argv[1])
4529                die("Option '--%s' requires a value", opt);
4530        *optarg = argv[1];
4531        return 2;
4532}
4533
4534static int stat_opt(struct diff_options *options, const char **av)
4535{
4536        const char *arg = av[0];
4537        char *end;
4538        int width = options->stat_width;
4539        int name_width = options->stat_name_width;
4540        int graph_width = options->stat_graph_width;
4541        int count = options->stat_count;
4542        int argcount = 1;
4543
4544        if (!skip_prefix(arg, "--stat", &arg))
4545                BUG("stat option does not begin with --stat: %s", arg);
4546        end = (char *)arg;
4547
4548        switch (*arg) {
4549        case '-':
4550                if (skip_prefix(arg, "-width", &arg)) {
4551                        if (*arg == '=')
4552                                width = strtoul(arg + 1, &end, 10);
4553                        else if (!*arg && !av[1])
4554                                die_want_option("--stat-width");
4555                        else if (!*arg) {
4556                                width = strtoul(av[1], &end, 10);
4557                                argcount = 2;
4558                        }
4559                } else if (skip_prefix(arg, "-name-width", &arg)) {
4560                        if (*arg == '=')
4561                                name_width = strtoul(arg + 1, &end, 10);
4562                        else if (!*arg && !av[1])
4563                                die_want_option("--stat-name-width");
4564                        else if (!*arg) {
4565                                name_width = strtoul(av[1], &end, 10);
4566                                argcount = 2;
4567                        }
4568                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4569                        if (*arg == '=')
4570                                graph_width = strtoul(arg + 1, &end, 10);
4571                        else if (!*arg && !av[1])
4572                                die_want_option("--stat-graph-width");
4573                        else if (!*arg) {
4574                                graph_width = strtoul(av[1], &end, 10);
4575                                argcount = 2;
4576                        }
4577                } else if (skip_prefix(arg, "-count", &arg)) {
4578                        if (*arg == '=')
4579                                count = strtoul(arg + 1, &end, 10);
4580                        else if (!*arg && !av[1])
4581                                die_want_option("--stat-count");
4582                        else if (!*arg) {
4583                                count = strtoul(av[1], &end, 10);
4584                                argcount = 2;
4585                        }
4586                }
4587                break;
4588        case '=':
4589                width = strtoul(arg+1, &end, 10);
4590                if (*end == ',')
4591                        name_width = strtoul(end+1, &end, 10);
4592                if (*end == ',')
4593                        count = strtoul(end+1, &end, 10);
4594        }
4595
4596        /* Important! This checks all the error cases! */
4597        if (*end)
4598                return 0;
4599        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4600        options->stat_name_width = name_width;
4601        options->stat_graph_width = graph_width;
4602        options->stat_width = width;
4603        options->stat_count = count;
4604        return argcount;
4605}
4606
4607static int parse_dirstat_opt(struct diff_options *options, const char *params)
4608{
4609        struct strbuf errmsg = STRBUF_INIT;
4610        if (parse_dirstat_params(options, params, &errmsg))
4611                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4612                    errmsg.buf);
4613        strbuf_release(&errmsg);
4614        /*
4615         * The caller knows a dirstat-related option is given from the command
4616         * line; allow it to say "return this_function();"
4617         */
4618        options->output_format |= DIFF_FORMAT_DIRSTAT;
4619        return 1;
4620}
4621
4622static int parse_submodule_opt(struct diff_options *options, const char *value)
4623{
4624        if (parse_submodule_params(options, value))
4625                die(_("Failed to parse --submodule option parameter: '%s'"),
4626                        value);
4627        return 1;
4628}
4629
4630static const char diff_status_letters[] = {
4631        DIFF_STATUS_ADDED,
4632        DIFF_STATUS_COPIED,
4633        DIFF_STATUS_DELETED,
4634        DIFF_STATUS_MODIFIED,
4635        DIFF_STATUS_RENAMED,
4636        DIFF_STATUS_TYPE_CHANGED,
4637        DIFF_STATUS_UNKNOWN,
4638        DIFF_STATUS_UNMERGED,
4639        DIFF_STATUS_FILTER_AON,
4640        DIFF_STATUS_FILTER_BROKEN,
4641        '\0',
4642};
4643
4644static unsigned int filter_bit['Z' + 1];
4645
4646static void prepare_filter_bits(void)
4647{
4648        int i;
4649
4650        if (!filter_bit[DIFF_STATUS_ADDED]) {
4651                for (i = 0; diff_status_letters[i]; i++)
4652                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4653        }
4654}
4655
4656static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4657{
4658        return opt->filter & filter_bit[(int) status];
4659}
4660
4661static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4662{
4663        int i, optch;
4664
4665        prepare_filter_bits();
4666
4667        /*
4668         * If there is a negation e.g. 'd' in the input, and we haven't
4669         * initialized the filter field with another --diff-filter, start
4670         * from full set of bits, except for AON.
4671         */
4672        if (!opt->filter) {
4673                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4674                        if (optch < 'a' || 'z' < optch)
4675                                continue;
4676                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4677                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4678                        break;
4679                }
4680        }
4681
4682        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4683                unsigned int bit;
4684                int negate;
4685
4686                if ('a' <= optch && optch <= 'z') {
4687                        negate = 1;
4688                        optch = toupper(optch);
4689                } else {
4690                        negate = 0;
4691                }
4692
4693                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4694                if (!bit)
4695                        return optarg[i];
4696                if (negate)
4697                        opt->filter &= ~bit;
4698                else
4699                        opt->filter |= bit;
4700        }
4701        return 0;
4702}
4703
4704static void enable_patch_output(int *fmt) {
4705        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4706        *fmt |= DIFF_FORMAT_PATCH;
4707}
4708
4709static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4710{
4711        int val = parse_ws_error_highlight(arg);
4712
4713        if (val < 0) {
4714                error("unknown value after ws-error-highlight=%.*s",
4715                      -1 - val, arg);
4716                return 0;
4717        }
4718        opt->ws_error_highlight = val;
4719        return 1;
4720}
4721
4722static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4723{
4724        struct object_id oid;
4725
4726        if (get_oid(arg, &oid))
4727                return error("unable to resolve '%s'", arg);
4728
4729        if (!opt->objfind)
4730                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4731
4732        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4733        opt->flags.recursive = 1;
4734        opt->flags.tree_in_recursive = 1;
4735        oidset_insert(opt->objfind, &oid);
4736        return 1;
4737}
4738
4739int diff_opt_parse(struct diff_options *options,
4740                   const char **av, int ac, const char *prefix)
4741{
4742        const char *arg = av[0];
4743        const char *optarg;
4744        int argcount;
4745
4746        if (!prefix)
4747                prefix = "";
4748
4749        /* Output format options */
4750        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4751            || opt_arg(arg, 'U', "unified", &options->context))
4752                enable_patch_output(&options->output_format);
4753        else if (!strcmp(arg, "--raw"))
4754                options->output_format |= DIFF_FORMAT_RAW;
4755        else if (!strcmp(arg, "--patch-with-raw")) {
4756                enable_patch_output(&options->output_format);
4757                options->output_format |= DIFF_FORMAT_RAW;
4758        } else if (!strcmp(arg, "--numstat"))
4759                options->output_format |= DIFF_FORMAT_NUMSTAT;
4760        else if (!strcmp(arg, "--shortstat"))
4761                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4762        else if (skip_prefix(arg, "-X", &arg) ||
4763                 skip_to_optional_arg(arg, "--dirstat", &arg))
4764                return parse_dirstat_opt(options, arg);
4765        else if (!strcmp(arg, "--cumulative"))
4766                return parse_dirstat_opt(options, "cumulative");
4767        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4768                parse_dirstat_opt(options, "files");
4769                return parse_dirstat_opt(options, arg);
4770        }
4771        else if (!strcmp(arg, "--check"))
4772                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4773        else if (!strcmp(arg, "--summary"))
4774                options->output_format |= DIFF_FORMAT_SUMMARY;
4775        else if (!strcmp(arg, "--patch-with-stat")) {
4776                enable_patch_output(&options->output_format);
4777                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4778        } else if (!strcmp(arg, "--name-only"))
4779                options->output_format |= DIFF_FORMAT_NAME;
4780        else if (!strcmp(arg, "--name-status"))
4781                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4782        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4783                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4784        else if (starts_with(arg, "--stat"))
4785                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4786                return stat_opt(options, av);
4787        else if (!strcmp(arg, "--compact-summary")) {
4788                 options->flags.stat_with_summary = 1;
4789                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4790        } else if (!strcmp(arg, "--no-compact-summary"))
4791                 options->flags.stat_with_summary = 0;
4792
4793        /* renames options */
4794        else if (starts_with(arg, "-B") ||
4795                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
4796                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4797                        return error("invalid argument to -B: %s", arg+2);
4798        }
4799        else if (starts_with(arg, "-M") ||
4800                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
4801                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4802                        return error("invalid argument to -M: %s", arg+2);
4803                options->detect_rename = DIFF_DETECT_RENAME;
4804        }
4805        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4806                options->irreversible_delete = 1;
4807        }
4808        else if (starts_with(arg, "-C") ||
4809                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
4810                if (options->detect_rename == DIFF_DETECT_COPY)
4811                        options->flags.find_copies_harder = 1;
4812                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4813                        return error("invalid argument to -C: %s", arg+2);
4814                options->detect_rename = DIFF_DETECT_COPY;
4815        }
4816        else if (!strcmp(arg, "--no-renames"))
4817                options->detect_rename = 0;
4818        else if (!strcmp(arg, "--rename-empty"))
4819                options->flags.rename_empty = 1;
4820        else if (!strcmp(arg, "--no-rename-empty"))
4821                options->flags.rename_empty = 0;
4822        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
4823                options->flags.relative_name = 1;
4824                if (arg)
4825                        options->prefix = arg;
4826        }
4827
4828        /* xdiff options */
4829        else if (!strcmp(arg, "--minimal"))
4830                DIFF_XDL_SET(options, NEED_MINIMAL);
4831        else if (!strcmp(arg, "--no-minimal"))
4832                DIFF_XDL_CLR(options, NEED_MINIMAL);
4833        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4834                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4835        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4836                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4837        else if (!strcmp(arg, "--ignore-space-at-eol"))
4838                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4839        else if (!strcmp(arg, "--ignore-cr-at-eol"))
4840                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
4841        else if (!strcmp(arg, "--ignore-blank-lines"))
4842                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4843        else if (!strcmp(arg, "--indent-heuristic"))
4844                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4845        else if (!strcmp(arg, "--no-indent-heuristic"))
4846                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4847        else if (!strcmp(arg, "--patience")) {
4848                int i;
4849                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4850                /*
4851                 * Both --patience and --anchored use PATIENCE_DIFF
4852                 * internally, so remove any anchors previously
4853                 * specified.
4854                 */
4855                for (i = 0; i < options->anchors_nr; i++)
4856                        free(options->anchors[i]);
4857                options->anchors_nr = 0;
4858        } else if (!strcmp(arg, "--histogram"))
4859                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4860        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4861                long value = parse_algorithm_value(optarg);
4862                if (value < 0)
4863                        return error("option diff-algorithm accepts \"myers\", "
4864                                     "\"minimal\", \"patience\" and \"histogram\"");
4865                /* clear out previous settings */
4866                DIFF_XDL_CLR(options, NEED_MINIMAL);
4867                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4868                options->xdl_opts |= value;
4869                return argcount;
4870        } else if (skip_prefix(arg, "--anchored=", &arg)) {
4871                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4872                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
4873                           options->anchors_alloc);
4874                options->anchors[options->anchors_nr++] = xstrdup(arg);
4875        }
4876
4877        /* flags options */
4878        else if (!strcmp(arg, "--binary")) {
4879                enable_patch_output(&options->output_format);
4880                options->flags.binary = 1;
4881        }
4882        else if (!strcmp(arg, "--full-index"))
4883                options->flags.full_index = 1;
4884        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4885                options->flags.text = 1;
4886        else if (!strcmp(arg, "-R"))
4887                options->flags.reverse_diff = 1;
4888        else if (!strcmp(arg, "--find-copies-harder"))
4889                options->flags.find_copies_harder = 1;
4890        else if (!strcmp(arg, "--follow"))
4891                options->flags.follow_renames = 1;
4892        else if (!strcmp(arg, "--no-follow")) {
4893                options->flags.follow_renames = 0;
4894                options->flags.default_follow_renames = 0;
4895        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
4896                int value = git_config_colorbool(NULL, arg);
4897                if (value < 0)
4898                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4899                options->use_color = value;
4900        }
4901        else if (!strcmp(arg, "--no-color"))
4902                options->use_color = 0;
4903        else if (!strcmp(arg, "--color-moved")) {
4904                if (diff_color_moved_default)
4905                        options->color_moved = diff_color_moved_default;
4906                if (options->color_moved == COLOR_MOVED_NO)
4907                        options->color_moved = COLOR_MOVED_DEFAULT;
4908        } else if (!strcmp(arg, "--no-color-moved"))
4909                options->color_moved = COLOR_MOVED_NO;
4910        else if (skip_prefix(arg, "--color-moved=", &arg)) {
4911                int cm = parse_color_moved(arg);
4912                if (cm < 0)
4913                        die("bad --color-moved argument: %s", arg);
4914                options->color_moved = cm;
4915        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
4916                options->color_moved_ws_handling = parse_color_moved_ws(arg);
4917        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
4918                options->use_color = 1;
4919                options->word_diff = DIFF_WORDS_COLOR;
4920        }
4921        else if (!strcmp(arg, "--word-diff")) {
4922                if (options->word_diff == DIFF_WORDS_NONE)
4923                        options->word_diff = DIFF_WORDS_PLAIN;
4924        }
4925        else if (skip_prefix(arg, "--word-diff=", &arg)) {
4926                if (!strcmp(arg, "plain"))
4927                        options->word_diff = DIFF_WORDS_PLAIN;
4928                else if (!strcmp(arg, "color")) {
4929                        options->use_color = 1;
4930                        options->word_diff = DIFF_WORDS_COLOR;
4931                }
4932                else if (!strcmp(arg, "porcelain"))
4933                        options->word_diff = DIFF_WORDS_PORCELAIN;
4934                else if (!strcmp(arg, "none"))
4935                        options->word_diff = DIFF_WORDS_NONE;
4936                else
4937                        die("bad --word-diff argument: %s", arg);
4938        }
4939        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
4940                if (options->word_diff == DIFF_WORDS_NONE)
4941                        options->word_diff = DIFF_WORDS_PLAIN;
4942                options->word_regex = optarg;
4943                return argcount;
4944        }
4945        else if (!strcmp(arg, "--exit-code"))
4946                options->flags.exit_with_status = 1;
4947        else if (!strcmp(arg, "--quiet"))
4948                options->flags.quick = 1;
4949        else if (!strcmp(arg, "--ext-diff"))
4950                options->flags.allow_external = 1;
4951        else if (!strcmp(arg, "--no-ext-diff"))
4952                options->flags.allow_external = 0;
4953        else if (!strcmp(arg, "--textconv")) {
4954                options->flags.allow_textconv = 1;
4955                options->flags.textconv_set_via_cmdline = 1;
4956        } else if (!strcmp(arg, "--no-textconv"))
4957                options->flags.allow_textconv = 0;
4958        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
4959                options->flags.override_submodule_config = 1;
4960                handle_ignore_submodules_arg(options, arg);
4961        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
4962                return parse_submodule_opt(options, arg);
4963        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
4964                return parse_ws_error_highlight_opt(options, arg);
4965        else if (!strcmp(arg, "--ita-invisible-in-index"))
4966                options->ita_invisible_in_index = 1;
4967        else if (!strcmp(arg, "--ita-visible-in-index"))
4968                options->ita_invisible_in_index = 0;
4969
4970        /* misc options */
4971        else if (!strcmp(arg, "-z"))
4972                options->line_termination = 0;
4973        else if ((argcount = short_opt('l', av, &optarg))) {
4974                options->rename_limit = strtoul(optarg, NULL, 10);
4975                return argcount;
4976        }
4977        else if ((argcount = short_opt('S', av, &optarg))) {
4978                options->pickaxe = optarg;
4979                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
4980                return argcount;
4981        } else if ((argcount = short_opt('G', av, &optarg))) {
4982                options->pickaxe = optarg;
4983                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
4984                return argcount;
4985        }
4986        else if (!strcmp(arg, "--pickaxe-all"))
4987                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
4988        else if (!strcmp(arg, "--pickaxe-regex"))
4989                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
4990        else if ((argcount = short_opt('O', av, &optarg))) {
4991                options->orderfile = prefix_filename(prefix, optarg);
4992                return argcount;
4993        } else if (skip_prefix(arg, "--find-object=", &arg))
4994                return parse_objfind_opt(options, arg);
4995        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
4996                int offending = parse_diff_filter_opt(optarg, options);
4997                if (offending)
4998                        die("unknown change class '%c' in --diff-filter=%s",
4999                            offending, optarg);
5000                return argcount;
5001        }
5002        else if (!strcmp(arg, "--no-abbrev"))
5003                options->abbrev = 0;
5004        else if (!strcmp(arg, "--abbrev"))
5005                options->abbrev = DEFAULT_ABBREV;
5006        else if (skip_prefix(arg, "--abbrev=", &arg)) {
5007                options->abbrev = strtoul(arg, NULL, 10);
5008                if (options->abbrev < MINIMUM_ABBREV)
5009                        options->abbrev = MINIMUM_ABBREV;
5010                else if (the_hash_algo->hexsz < options->abbrev)
5011                        options->abbrev = the_hash_algo->hexsz;
5012        }
5013        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5014                options->a_prefix = optarg;
5015                return argcount;
5016        }
5017        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5018                options->line_prefix = optarg;
5019                options->line_prefix_length = strlen(options->line_prefix);
5020                graph_setup_line_prefix(options);
5021                return argcount;
5022        }
5023        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5024                options->b_prefix = optarg;
5025                return argcount;
5026        }
5027        else if (!strcmp(arg, "--no-prefix"))
5028                options->a_prefix = options->b_prefix = "";
5029        else if (opt_arg(arg, '\0', "inter-hunk-context",
5030                         &options->interhunkcontext))
5031                ;
5032        else if (!strcmp(arg, "-W"))
5033                options->flags.funccontext = 1;
5034        else if (!strcmp(arg, "--function-context"))
5035                options->flags.funccontext = 1;
5036        else if (!strcmp(arg, "--no-function-context"))
5037                options->flags.funccontext = 0;
5038        else if ((argcount = parse_long_opt("output", av, &optarg))) {
5039                char *path = prefix_filename(prefix, optarg);
5040                options->file = xfopen(path, "w");
5041                options->close_file = 1;
5042                if (options->use_color != GIT_COLOR_ALWAYS)
5043                        options->use_color = GIT_COLOR_NEVER;
5044                free(path);
5045                return argcount;
5046        } else
5047                return 0;
5048        return 1;
5049}
5050
5051int parse_rename_score(const char **cp_p)
5052{
5053        unsigned long num, scale;
5054        int ch, dot;
5055        const char *cp = *cp_p;
5056
5057        num = 0;
5058        scale = 1;
5059        dot = 0;
5060        for (;;) {
5061                ch = *cp;
5062                if ( !dot && ch == '.' ) {
5063                        scale = 1;
5064                        dot = 1;
5065                } else if ( ch == '%' ) {
5066                        scale = dot ? scale*100 : 100;
5067                        cp++;   /* % is always at the end */
5068                        break;
5069                } else if ( ch >= '0' && ch <= '9' ) {
5070                        if ( scale < 100000 ) {
5071                                scale *= 10;
5072                                num = (num*10) + (ch-'0');
5073                        }
5074                } else {
5075                        break;
5076                }
5077                cp++;
5078        }
5079        *cp_p = cp;
5080
5081        /* user says num divided by scale and we say internally that
5082         * is MAX_SCORE * num / scale.
5083         */
5084        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5085}
5086
5087static int diff_scoreopt_parse(const char *opt)
5088{
5089        int opt1, opt2, cmd;
5090
5091        if (*opt++ != '-')
5092                return -1;
5093        cmd = *opt++;
5094        if (cmd == '-') {
5095                /* convert the long-form arguments into short-form versions */
5096                if (skip_prefix(opt, "break-rewrites", &opt)) {
5097                        if (*opt == 0 || *opt++ == '=')
5098                                cmd = 'B';
5099                } else if (skip_prefix(opt, "find-copies", &opt)) {
5100                        if (*opt == 0 || *opt++ == '=')
5101                                cmd = 'C';
5102                } else if (skip_prefix(opt, "find-renames", &opt)) {
5103                        if (*opt == 0 || *opt++ == '=')
5104                                cmd = 'M';
5105                }
5106        }
5107        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
5108                return -1; /* that is not a -M, -C, or -B option */
5109
5110        opt1 = parse_rename_score(&opt);
5111        if (cmd != 'B')
5112                opt2 = 0;
5113        else {
5114                if (*opt == 0)
5115                        opt2 = 0;
5116                else if (*opt != '/')
5117                        return -1; /* we expect -B80/99 or -B80 */
5118                else {
5119                        opt++;
5120                        opt2 = parse_rename_score(&opt);
5121                }
5122        }
5123        if (*opt != 0)
5124                return -1;
5125        return opt1 | (opt2 << 16);
5126}
5127
5128struct diff_queue_struct diff_queued_diff;
5129
5130void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5131{
5132        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5133        queue->queue[queue->nr++] = dp;
5134}
5135
5136struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5137                                 struct diff_filespec *one,
5138                                 struct diff_filespec *two)
5139{
5140        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5141        dp->one = one;
5142        dp->two = two;
5143        if (queue)
5144                diff_q(queue, dp);
5145        return dp;
5146}
5147
5148void diff_free_filepair(struct diff_filepair *p)
5149{
5150        free_filespec(p->one);
5151        free_filespec(p->two);
5152        free(p);
5153}
5154
5155const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5156{
5157        int abblen;
5158        const char *abbrev;
5159
5160        /* Do we want all 40 hex characters? */
5161        if (len == the_hash_algo->hexsz)
5162                return oid_to_hex(oid);
5163
5164        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5165        abbrev = diff_abbrev_oid(oid, len);
5166
5167        if (!print_sha1_ellipsis())
5168                return abbrev;
5169
5170        abblen = strlen(abbrev);
5171
5172        /*
5173         * In well-behaved cases, where the abbreviated result is the
5174         * same as the requested length, append three dots after the
5175         * abbreviation (hence the whole logic is limited to the case
5176         * where abblen < 37); when the actual abbreviated result is a
5177         * bit longer than the requested length, we reduce the number
5178         * of dots so that they match the well-behaved ones.  However,
5179         * if the actual abbreviation is longer than the requested
5180         * length by more than three, we give up on aligning, and add
5181         * three dots anyway, to indicate that the output is not the
5182         * full object name.  Yes, this may be suboptimal, but this
5183         * appears only in "diff --raw --abbrev" output and it is not
5184         * worth the effort to change it now.  Note that this would
5185         * likely to work fine when the automatic sizing of default
5186         * abbreviation length is used--we would be fed -1 in "len" in
5187         * that case, and will end up always appending three-dots, but
5188         * the automatic sizing is supposed to give abblen that ensures
5189         * uniqueness across all objects (statistically speaking).
5190         */
5191        if (abblen < the_hash_algo->hexsz - 3) {
5192                static char hex[GIT_MAX_HEXSZ + 1];
5193                if (len < abblen && abblen <= len + 2)
5194                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5195                else
5196                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5197                return hex;
5198        }
5199
5200        return oid_to_hex(oid);
5201}
5202
5203static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5204{
5205        int line_termination = opt->line_termination;
5206        int inter_name_termination = line_termination ? '\t' : '\0';
5207
5208        fprintf(opt->file, "%s", diff_line_prefix(opt));
5209        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5210                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5211                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5212                fprintf(opt->file, "%s ",
5213                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5214        }
5215        if (p->score) {
5216                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5217                        inter_name_termination);
5218        } else {
5219                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5220        }
5221
5222        if (p->status == DIFF_STATUS_COPIED ||
5223            p->status == DIFF_STATUS_RENAMED) {
5224                const char *name_a, *name_b;
5225                name_a = p->one->path;
5226                name_b = p->two->path;
5227                strip_prefix(opt->prefix_length, &name_a, &name_b);
5228                write_name_quoted(name_a, opt->file, inter_name_termination);
5229                write_name_quoted(name_b, opt->file, line_termination);
5230        } else {
5231                const char *name_a, *name_b;
5232                name_a = p->one->mode ? p->one->path : p->two->path;
5233                name_b = NULL;
5234                strip_prefix(opt->prefix_length, &name_a, &name_b);
5235                write_name_quoted(name_a, opt->file, line_termination);
5236        }
5237}
5238
5239int diff_unmodified_pair(struct diff_filepair *p)
5240{
5241        /* This function is written stricter than necessary to support
5242         * the currently implemented transformers, but the idea is to
5243         * let transformers to produce diff_filepairs any way they want,
5244         * and filter and clean them up here before producing the output.
5245         */
5246        struct diff_filespec *one = p->one, *two = p->two;
5247
5248        if (DIFF_PAIR_UNMERGED(p))
5249                return 0; /* unmerged is interesting */
5250
5251        /* deletion, addition, mode or type change
5252         * and rename are all interesting.
5253         */
5254        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5255            DIFF_PAIR_MODE_CHANGED(p) ||
5256            strcmp(one->path, two->path))
5257                return 0;
5258
5259        /* both are valid and point at the same path.  that is, we are
5260         * dealing with a change.
5261         */
5262        if (one->oid_valid && two->oid_valid &&
5263            !oidcmp(&one->oid, &two->oid) &&
5264            !one->dirty_submodule && !two->dirty_submodule)
5265                return 1; /* no change */
5266        if (!one->oid_valid && !two->oid_valid)
5267                return 1; /* both look at the same file on the filesystem. */
5268        return 0;
5269}
5270
5271static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5272{
5273        if (diff_unmodified_pair(p))
5274                return;
5275
5276        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5277            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5278                return; /* no tree diffs in patch format */
5279
5280        run_diff(p, o);
5281}
5282
5283static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5284                            struct diffstat_t *diffstat)
5285{
5286        if (diff_unmodified_pair(p))
5287                return;
5288
5289        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5290            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5291                return; /* no useful stat for tree diffs */
5292
5293        run_diffstat(p, o, diffstat);
5294}
5295
5296static void diff_flush_checkdiff(struct diff_filepair *p,
5297                struct diff_options *o)
5298{
5299        if (diff_unmodified_pair(p))
5300                return;
5301
5302        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5303            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5304                return; /* nothing to check in tree diffs */
5305
5306        run_checkdiff(p, o);
5307}
5308
5309int diff_queue_is_empty(void)
5310{
5311        struct diff_queue_struct *q = &diff_queued_diff;
5312        int i;
5313        for (i = 0; i < q->nr; i++)
5314                if (!diff_unmodified_pair(q->queue[i]))
5315                        return 0;
5316        return 1;
5317}
5318
5319#if DIFF_DEBUG
5320void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5321{
5322        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5323                x, one ? one : "",
5324                s->path,
5325                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5326                s->mode,
5327                s->oid_valid ? oid_to_hex(&s->oid) : "");
5328        fprintf(stderr, "queue[%d] %s size %lu\n",
5329                x, one ? one : "",
5330                s->size);
5331}
5332
5333void diff_debug_filepair(const struct diff_filepair *p, int i)
5334{
5335        diff_debug_filespec(p->one, i, "one");
5336        diff_debug_filespec(p->two, i, "two");
5337        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5338                p->score, p->status ? p->status : '?',
5339                p->one->rename_used, p->broken_pair);
5340}
5341
5342void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5343{
5344        int i;
5345        if (msg)
5346                fprintf(stderr, "%s\n", msg);
5347        fprintf(stderr, "q->nr = %d\n", q->nr);
5348        for (i = 0; i < q->nr; i++) {
5349                struct diff_filepair *p = q->queue[i];
5350                diff_debug_filepair(p, i);
5351        }
5352}
5353#endif
5354
5355static void diff_resolve_rename_copy(void)
5356{
5357        int i;
5358        struct diff_filepair *p;
5359        struct diff_queue_struct *q = &diff_queued_diff;
5360
5361        diff_debug_queue("resolve-rename-copy", q);
5362
5363        for (i = 0; i < q->nr; i++) {
5364                p = q->queue[i];
5365                p->status = 0; /* undecided */
5366                if (DIFF_PAIR_UNMERGED(p))
5367                        p->status = DIFF_STATUS_UNMERGED;
5368                else if (!DIFF_FILE_VALID(p->one))
5369                        p->status = DIFF_STATUS_ADDED;
5370                else if (!DIFF_FILE_VALID(p->two))
5371                        p->status = DIFF_STATUS_DELETED;
5372                else if (DIFF_PAIR_TYPE_CHANGED(p))
5373                        p->status = DIFF_STATUS_TYPE_CHANGED;
5374
5375                /* from this point on, we are dealing with a pair
5376                 * whose both sides are valid and of the same type, i.e.
5377                 * either in-place edit or rename/copy edit.
5378                 */
5379                else if (DIFF_PAIR_RENAME(p)) {
5380                        /*
5381                         * A rename might have re-connected a broken
5382                         * pair up, causing the pathnames to be the
5383                         * same again. If so, that's not a rename at
5384                         * all, just a modification..
5385                         *
5386                         * Otherwise, see if this source was used for
5387                         * multiple renames, in which case we decrement
5388                         * the count, and call it a copy.
5389                         */
5390                        if (!strcmp(p->one->path, p->two->path))
5391                                p->status = DIFF_STATUS_MODIFIED;
5392                        else if (--p->one->rename_used > 0)
5393                                p->status = DIFF_STATUS_COPIED;
5394                        else
5395                                p->status = DIFF_STATUS_RENAMED;
5396                }
5397                else if (oidcmp(&p->one->oid, &p->two->oid) ||
5398                         p->one->mode != p->two->mode ||
5399                         p->one->dirty_submodule ||
5400                         p->two->dirty_submodule ||
5401                         is_null_oid(&p->one->oid))
5402                        p->status = DIFF_STATUS_MODIFIED;
5403                else {
5404                        /* This is a "no-change" entry and should not
5405                         * happen anymore, but prepare for broken callers.
5406                         */
5407                        error("feeding unmodified %s to diffcore",
5408                              p->one->path);
5409                        p->status = DIFF_STATUS_UNKNOWN;
5410                }
5411        }
5412        diff_debug_queue("resolve-rename-copy done", q);
5413}
5414
5415static int check_pair_status(struct diff_filepair *p)
5416{
5417        switch (p->status) {
5418        case DIFF_STATUS_UNKNOWN:
5419                return 0;
5420        case 0:
5421                die("internal error in diff-resolve-rename-copy");
5422        default:
5423                return 1;
5424        }
5425}
5426
5427static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5428{
5429        int fmt = opt->output_format;
5430
5431        if (fmt & DIFF_FORMAT_CHECKDIFF)
5432                diff_flush_checkdiff(p, opt);
5433        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5434                diff_flush_raw(p, opt);
5435        else if (fmt & DIFF_FORMAT_NAME) {
5436                const char *name_a, *name_b;
5437                name_a = p->two->path;
5438                name_b = NULL;
5439                strip_prefix(opt->prefix_length, &name_a, &name_b);
5440                fprintf(opt->file, "%s", diff_line_prefix(opt));
5441                write_name_quoted(name_a, opt->file, opt->line_termination);
5442        }
5443}
5444
5445static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5446{
5447        struct strbuf sb = STRBUF_INIT;
5448        if (fs->mode)
5449                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5450        else
5451                strbuf_addf(&sb, " %s ", newdelete);
5452
5453        quote_c_style(fs->path, &sb, NULL, 0);
5454        strbuf_addch(&sb, '\n');
5455        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5456                         sb.buf, sb.len, 0);
5457        strbuf_release(&sb);
5458}
5459
5460static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5461                int show_name)
5462{
5463        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5464                struct strbuf sb = STRBUF_INIT;
5465                strbuf_addf(&sb, " mode change %06o => %06o",
5466                            p->one->mode, p->two->mode);
5467                if (show_name) {
5468                        strbuf_addch(&sb, ' ');
5469                        quote_c_style(p->two->path, &sb, NULL, 0);
5470                }
5471                strbuf_addch(&sb, '\n');
5472                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5473                                 sb.buf, sb.len, 0);
5474                strbuf_release(&sb);
5475        }
5476}
5477
5478static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5479                struct diff_filepair *p)
5480{
5481        struct strbuf sb = STRBUF_INIT;
5482        struct strbuf names = STRBUF_INIT;
5483
5484        pprint_rename(&names, p->one->path, p->two->path);
5485        strbuf_addf(&sb, " %s %s (%d%%)\n",
5486                    renamecopy, names.buf, similarity_index(p));
5487        strbuf_release(&names);
5488        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5489                                 sb.buf, sb.len, 0);
5490        show_mode_change(opt, p, 0);
5491        strbuf_release(&sb);
5492}
5493
5494static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5495{
5496        switch(p->status) {
5497        case DIFF_STATUS_DELETED:
5498                show_file_mode_name(opt, "delete", p->one);
5499                break;
5500        case DIFF_STATUS_ADDED:
5501                show_file_mode_name(opt, "create", p->two);
5502                break;
5503        case DIFF_STATUS_COPIED:
5504                show_rename_copy(opt, "copy", p);
5505                break;
5506        case DIFF_STATUS_RENAMED:
5507                show_rename_copy(opt, "rename", p);
5508                break;
5509        default:
5510                if (p->score) {
5511                        struct strbuf sb = STRBUF_INIT;
5512                        strbuf_addstr(&sb, " rewrite ");
5513                        quote_c_style(p->two->path, &sb, NULL, 0);
5514                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5515                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5516                                         sb.buf, sb.len, 0);
5517                        strbuf_release(&sb);
5518                }
5519                show_mode_change(opt, p, !p->score);
5520                break;
5521        }
5522}
5523
5524struct patch_id_t {
5525        git_SHA_CTX *ctx;
5526        int patchlen;
5527};
5528
5529static int remove_space(char *line, int len)
5530{
5531        int i;
5532        char *dst = line;
5533        unsigned char c;
5534
5535        for (i = 0; i < len; i++)
5536                if (!isspace((c = line[i])))
5537                        *dst++ = c;
5538
5539        return dst - line;
5540}
5541
5542static void patch_id_consume(void *priv, char *line, unsigned long len)
5543{
5544        struct patch_id_t *data = priv;
5545        int new_len;
5546
5547        /* Ignore line numbers when computing the SHA1 of the patch */
5548        if (starts_with(line, "@@ -"))
5549                return;
5550
5551        new_len = remove_space(line, len);
5552
5553        git_SHA1_Update(data->ctx, line, new_len);
5554        data->patchlen += new_len;
5555}
5556
5557static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5558{
5559        git_SHA1_Update(ctx, str, strlen(str));
5560}
5561
5562static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5563{
5564        /* large enough for 2^32 in octal */
5565        char buf[12];
5566        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5567        git_SHA1_Update(ctx, buf, len);
5568}
5569
5570/* returns 0 upon success, and writes result into sha1 */
5571static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5572{
5573        struct diff_queue_struct *q = &diff_queued_diff;
5574        int i;
5575        git_SHA_CTX ctx;
5576        struct patch_id_t data;
5577
5578        git_SHA1_Init(&ctx);
5579        memset(&data, 0, sizeof(struct patch_id_t));
5580        data.ctx = &ctx;
5581
5582        for (i = 0; i < q->nr; i++) {
5583                xpparam_t xpp;
5584                xdemitconf_t xecfg;
5585                mmfile_t mf1, mf2;
5586                struct diff_filepair *p = q->queue[i];
5587                int len1, len2;
5588
5589                memset(&xpp, 0, sizeof(xpp));
5590                memset(&xecfg, 0, sizeof(xecfg));
5591                if (p->status == 0)
5592                        return error("internal diff status error");
5593                if (p->status == DIFF_STATUS_UNKNOWN)
5594                        continue;
5595                if (diff_unmodified_pair(p))
5596                        continue;
5597                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5598                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5599                        continue;
5600                if (DIFF_PAIR_UNMERGED(p))
5601                        continue;
5602
5603                diff_fill_oid_info(p->one);
5604                diff_fill_oid_info(p->two);
5605
5606                len1 = remove_space(p->one->path, strlen(p->one->path));
5607                len2 = remove_space(p->two->path, strlen(p->two->path));
5608                patch_id_add_string(&ctx, "diff--git");
5609                patch_id_add_string(&ctx, "a/");
5610                git_SHA1_Update(&ctx, p->one->path, len1);
5611                patch_id_add_string(&ctx, "b/");
5612                git_SHA1_Update(&ctx, p->two->path, len2);
5613
5614                if (p->one->mode == 0) {
5615                        patch_id_add_string(&ctx, "newfilemode");
5616                        patch_id_add_mode(&ctx, p->two->mode);
5617                        patch_id_add_string(&ctx, "---/dev/null");
5618                        patch_id_add_string(&ctx, "+++b/");
5619                        git_SHA1_Update(&ctx, p->two->path, len2);
5620                } else if (p->two->mode == 0) {
5621                        patch_id_add_string(&ctx, "deletedfilemode");
5622                        patch_id_add_mode(&ctx, p->one->mode);
5623                        patch_id_add_string(&ctx, "---a/");
5624                        git_SHA1_Update(&ctx, p->one->path, len1);
5625                        patch_id_add_string(&ctx, "+++/dev/null");
5626                } else {
5627                        patch_id_add_string(&ctx, "---a/");
5628                        git_SHA1_Update(&ctx, p->one->path, len1);
5629                        patch_id_add_string(&ctx, "+++b/");
5630                        git_SHA1_Update(&ctx, p->two->path, len2);
5631                }
5632
5633                if (diff_header_only)
5634                        continue;
5635
5636                if (fill_mmfile(&mf1, p->one) < 0 ||
5637                    fill_mmfile(&mf2, p->two) < 0)
5638                        return error("unable to read files to diff");
5639
5640                if (diff_filespec_is_binary(p->one) ||
5641                    diff_filespec_is_binary(p->two)) {
5642                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5643                                        GIT_SHA1_HEXSZ);
5644                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5645                                        GIT_SHA1_HEXSZ);
5646                        continue;
5647                }
5648
5649                xpp.flags = 0;
5650                xecfg.ctxlen = 3;
5651                xecfg.flags = 0;
5652                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
5653                                  &xpp, &xecfg))
5654                        return error("unable to generate patch-id diff for %s",
5655                                     p->one->path);
5656        }
5657
5658        git_SHA1_Final(oid->hash, &ctx);
5659        return 0;
5660}
5661
5662int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5663{
5664        struct diff_queue_struct *q = &diff_queued_diff;
5665        int i;
5666        int result = diff_get_patch_id(options, oid, diff_header_only);
5667
5668        for (i = 0; i < q->nr; i++)
5669                diff_free_filepair(q->queue[i]);
5670
5671        free(q->queue);
5672        DIFF_QUEUE_CLEAR(q);
5673
5674        return result;
5675}
5676
5677static int is_summary_empty(const struct diff_queue_struct *q)
5678{
5679        int i;
5680
5681        for (i = 0; i < q->nr; i++) {
5682                const struct diff_filepair *p = q->queue[i];
5683
5684                switch (p->status) {
5685                case DIFF_STATUS_DELETED:
5686                case DIFF_STATUS_ADDED:
5687                case DIFF_STATUS_COPIED:
5688                case DIFF_STATUS_RENAMED:
5689                        return 0;
5690                default:
5691                        if (p->score)
5692                                return 0;
5693                        if (p->one->mode && p->two->mode &&
5694                            p->one->mode != p->two->mode)
5695                                return 0;
5696                        break;
5697                }
5698        }
5699        return 1;
5700}
5701
5702static const char rename_limit_warning[] =
5703N_("inexact rename detection was skipped due to too many files.");
5704
5705static const char degrade_cc_to_c_warning[] =
5706N_("only found copies from modified paths due to too many files.");
5707
5708static const char rename_limit_advice[] =
5709N_("you may want to set your %s variable to at least "
5710   "%d and retry the command.");
5711
5712void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5713{
5714        fflush(stdout);
5715        if (degraded_cc)
5716                warning(_(degrade_cc_to_c_warning));
5717        else if (needed)
5718                warning(_(rename_limit_warning));
5719        else
5720                return;
5721        if (0 < needed)
5722                warning(_(rename_limit_advice), varname, needed);
5723}
5724
5725static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5726{
5727        int i;
5728        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5729        struct diff_queue_struct *q = &diff_queued_diff;
5730
5731        if (WSEH_NEW & WS_RULE_MASK)
5732                BUG("WS rules bit mask overlaps with diff symbol flags");
5733
5734        if (o->color_moved)
5735                o->emitted_symbols = &esm;
5736
5737        for (i = 0; i < q->nr; i++) {
5738                struct diff_filepair *p = q->queue[i];
5739                if (check_pair_status(p))
5740                        diff_flush_patch(p, o);
5741        }
5742
5743        if (o->emitted_symbols) {
5744                if (o->color_moved) {
5745                        struct hashmap add_lines, del_lines;
5746
5747                        if (o->color_moved_ws_handling &
5748                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
5749                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
5750
5751                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
5752                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
5753
5754                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5755                        mark_color_as_moved(o, &add_lines, &del_lines);
5756                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5757                                dim_moved_lines(o);
5758
5759                        hashmap_free(&add_lines, 0);
5760                        hashmap_free(&del_lines, 0);
5761                }
5762
5763                for (i = 0; i < esm.nr; i++)
5764                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5765
5766                for (i = 0; i < esm.nr; i++)
5767                        free((void *)esm.buf[i].line);
5768        }
5769        esm.nr = 0;
5770}
5771
5772void diff_flush(struct diff_options *options)
5773{
5774        struct diff_queue_struct *q = &diff_queued_diff;
5775        int i, output_format = options->output_format;
5776        int separator = 0;
5777        int dirstat_by_line = 0;
5778
5779        /*
5780         * Order: raw, stat, summary, patch
5781         * or:    name/name-status/checkdiff (other bits clear)
5782         */
5783        if (!q->nr)
5784                goto free_queue;
5785
5786        if (output_format & (DIFF_FORMAT_RAW |
5787                             DIFF_FORMAT_NAME |
5788                             DIFF_FORMAT_NAME_STATUS |
5789                             DIFF_FORMAT_CHECKDIFF)) {
5790                for (i = 0; i < q->nr; i++) {
5791                        struct diff_filepair *p = q->queue[i];
5792                        if (check_pair_status(p))
5793                                flush_one_pair(p, options);
5794                }
5795                separator++;
5796        }
5797
5798        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5799                dirstat_by_line = 1;
5800
5801        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5802            dirstat_by_line) {
5803                struct diffstat_t diffstat;
5804
5805                memset(&diffstat, 0, sizeof(struct diffstat_t));
5806                for (i = 0; i < q->nr; i++) {
5807                        struct diff_filepair *p = q->queue[i];
5808                        if (check_pair_status(p))
5809                                diff_flush_stat(p, options, &diffstat);
5810                }
5811                if (output_format & DIFF_FORMAT_NUMSTAT)
5812                        show_numstat(&diffstat, options);
5813                if (output_format & DIFF_FORMAT_DIFFSTAT)
5814                        show_stats(&diffstat, options);
5815                if (output_format & DIFF_FORMAT_SHORTSTAT)
5816                        show_shortstats(&diffstat, options);
5817                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5818                        show_dirstat_by_line(&diffstat, options);
5819                free_diffstat_info(&diffstat);
5820                separator++;
5821        }
5822        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5823                show_dirstat(options);
5824
5825        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5826                for (i = 0; i < q->nr; i++) {
5827                        diff_summary(options, q->queue[i]);
5828                }
5829                separator++;
5830        }
5831
5832        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5833            options->flags.exit_with_status &&
5834            options->flags.diff_from_contents) {
5835                /*
5836                 * run diff_flush_patch for the exit status. setting
5837                 * options->file to /dev/null should be safe, because we
5838                 * aren't supposed to produce any output anyway.
5839                 */
5840                if (options->close_file)
5841                        fclose(options->file);
5842                options->file = xfopen("/dev/null", "w");
5843                options->close_file = 1;
5844                options->color_moved = 0;
5845                for (i = 0; i < q->nr; i++) {
5846                        struct diff_filepair *p = q->queue[i];
5847                        if (check_pair_status(p))
5848                                diff_flush_patch(p, options);
5849                        if (options->found_changes)
5850                                break;
5851                }
5852        }
5853
5854        if (output_format & DIFF_FORMAT_PATCH) {
5855                if (separator) {
5856                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5857                        if (options->stat_sep)
5858                                /* attach patch instead of inline */
5859                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5860                                                 NULL, 0, 0);
5861                }
5862
5863                diff_flush_patch_all_file_pairs(options);
5864        }
5865
5866        if (output_format & DIFF_FORMAT_CALLBACK)
5867                options->format_callback(q, options, options->format_callback_data);
5868
5869        for (i = 0; i < q->nr; i++)
5870                diff_free_filepair(q->queue[i]);
5871free_queue:
5872        free(q->queue);
5873        DIFF_QUEUE_CLEAR(q);
5874        if (options->close_file)
5875                fclose(options->file);
5876
5877        /*
5878         * Report the content-level differences with HAS_CHANGES;
5879         * diff_addremove/diff_change does not set the bit when
5880         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5881         */
5882        if (options->flags.diff_from_contents) {
5883                if (options->found_changes)
5884                        options->flags.has_changes = 1;
5885                else
5886                        options->flags.has_changes = 0;
5887        }
5888}
5889
5890static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5891{
5892        return (((p->status == DIFF_STATUS_MODIFIED) &&
5893                 ((p->score &&
5894                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5895                  (!p->score &&
5896                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5897                ((p->status != DIFF_STATUS_MODIFIED) &&
5898                 filter_bit_tst(p->status, options)));
5899}
5900
5901static void diffcore_apply_filter(struct diff_options *options)
5902{
5903        int i;
5904        struct diff_queue_struct *q = &diff_queued_diff;
5905        struct diff_queue_struct outq;
5906
5907        DIFF_QUEUE_CLEAR(&outq);
5908
5909        if (!options->filter)
5910                return;
5911
5912        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
5913                int found;
5914                for (i = found = 0; !found && i < q->nr; i++) {
5915                        if (match_filter(options, q->queue[i]))
5916                                found++;
5917                }
5918                if (found)
5919                        return;
5920
5921                /* otherwise we will clear the whole queue
5922                 * by copying the empty outq at the end of this
5923                 * function, but first clear the current entries
5924                 * in the queue.
5925                 */
5926                for (i = 0; i < q->nr; i++)
5927                        diff_free_filepair(q->queue[i]);
5928        }
5929        else {
5930                /* Only the matching ones */
5931                for (i = 0; i < q->nr; i++) {
5932                        struct diff_filepair *p = q->queue[i];
5933                        if (match_filter(options, p))
5934                                diff_q(&outq, p);
5935                        else
5936                                diff_free_filepair(p);
5937                }
5938        }
5939        free(q->queue);
5940        *q = outq;
5941}
5942
5943/* Check whether two filespecs with the same mode and size are identical */
5944static int diff_filespec_is_identical(struct diff_filespec *one,
5945                                      struct diff_filespec *two)
5946{
5947        if (S_ISGITLINK(one->mode))
5948                return 0;
5949        if (diff_populate_filespec(one, 0))
5950                return 0;
5951        if (diff_populate_filespec(two, 0))
5952                return 0;
5953        return !memcmp(one->data, two->data, one->size);
5954}
5955
5956static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
5957{
5958        if (p->done_skip_stat_unmatch)
5959                return p->skip_stat_unmatch_result;
5960
5961        p->done_skip_stat_unmatch = 1;
5962        p->skip_stat_unmatch_result = 0;
5963        /*
5964         * 1. Entries that come from stat info dirtiness
5965         *    always have both sides (iow, not create/delete),
5966         *    one side of the object name is unknown, with
5967         *    the same mode and size.  Keep the ones that
5968         *    do not match these criteria.  They have real
5969         *    differences.
5970         *
5971         * 2. At this point, the file is known to be modified,
5972         *    with the same mode and size, and the object
5973         *    name of one side is unknown.  Need to inspect
5974         *    the identical contents.
5975         */
5976        if (!DIFF_FILE_VALID(p->one) || /* (1) */
5977            !DIFF_FILE_VALID(p->two) ||
5978            (p->one->oid_valid && p->two->oid_valid) ||
5979            (p->one->mode != p->two->mode) ||
5980            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
5981            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
5982            (p->one->size != p->two->size) ||
5983            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
5984                p->skip_stat_unmatch_result = 1;
5985        return p->skip_stat_unmatch_result;
5986}
5987
5988static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
5989{
5990        int i;
5991        struct diff_queue_struct *q = &diff_queued_diff;
5992        struct diff_queue_struct outq;
5993        DIFF_QUEUE_CLEAR(&outq);
5994
5995        for (i = 0; i < q->nr; i++) {
5996                struct diff_filepair *p = q->queue[i];
5997
5998                if (diff_filespec_check_stat_unmatch(p))
5999                        diff_q(&outq, p);
6000                else {
6001                        /*
6002                         * The caller can subtract 1 from skip_stat_unmatch
6003                         * to determine how many paths were dirty only
6004                         * due to stat info mismatch.
6005                         */
6006                        if (!diffopt->flags.no_index)
6007                                diffopt->skip_stat_unmatch++;
6008                        diff_free_filepair(p);
6009                }
6010        }
6011        free(q->queue);
6012        *q = outq;
6013}
6014
6015static int diffnamecmp(const void *a_, const void *b_)
6016{
6017        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6018        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6019        const char *name_a, *name_b;
6020
6021        name_a = a->one ? a->one->path : a->two->path;
6022        name_b = b->one ? b->one->path : b->two->path;
6023        return strcmp(name_a, name_b);
6024}
6025
6026void diffcore_fix_diff_index(struct diff_options *options)
6027{
6028        struct diff_queue_struct *q = &diff_queued_diff;
6029        QSORT(q->queue, q->nr, diffnamecmp);
6030}
6031
6032void diffcore_std(struct diff_options *options)
6033{
6034        /* NOTE please keep the following in sync with diff_tree_combined() */
6035        if (options->skip_stat_unmatch)
6036                diffcore_skip_stat_unmatch(options);
6037        if (!options->found_follow) {
6038                /* See try_to_follow_renames() in tree-diff.c */
6039                if (options->break_opt != -1)
6040                        diffcore_break(options->break_opt);
6041                if (options->detect_rename)
6042                        diffcore_rename(options);
6043                if (options->break_opt != -1)
6044                        diffcore_merge_broken();
6045        }
6046        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6047                diffcore_pickaxe(options);
6048        if (options->orderfile)
6049                diffcore_order(options->orderfile);
6050        if (!options->found_follow)
6051                /* See try_to_follow_renames() in tree-diff.c */
6052                diff_resolve_rename_copy();
6053        diffcore_apply_filter(options);
6054
6055        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6056                options->flags.has_changes = 1;
6057        else
6058                options->flags.has_changes = 0;
6059
6060        options->found_follow = 0;
6061}
6062
6063int diff_result_code(struct diff_options *opt, int status)
6064{
6065        int result = 0;
6066
6067        diff_warn_rename_limit("diff.renameLimit",
6068                               opt->needed_rename_limit,
6069                               opt->degraded_cc_to_c);
6070        if (!opt->flags.exit_with_status &&
6071            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6072                return status;
6073        if (opt->flags.exit_with_status &&
6074            opt->flags.has_changes)
6075                result |= 01;
6076        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6077            opt->flags.check_failed)
6078                result |= 02;
6079        return result;
6080}
6081
6082int diff_can_quit_early(struct diff_options *opt)
6083{
6084        return (opt->flags.quick &&
6085                !opt->filter &&
6086                opt->flags.has_changes);
6087}
6088
6089/*
6090 * Shall changes to this submodule be ignored?
6091 *
6092 * Submodule changes can be configured to be ignored separately for each path,
6093 * but that configuration can be overridden from the command line.
6094 */
6095static int is_submodule_ignored(const char *path, struct diff_options *options)
6096{
6097        int ignored = 0;
6098        struct diff_flags orig_flags = options->flags;
6099        if (!options->flags.override_submodule_config)
6100                set_diffopt_flags_from_submodule_config(options, path);
6101        if (options->flags.ignore_submodules)
6102                ignored = 1;
6103        options->flags = orig_flags;
6104        return ignored;
6105}
6106
6107void diff_addremove(struct diff_options *options,
6108                    int addremove, unsigned mode,
6109                    const struct object_id *oid,
6110                    int oid_valid,
6111                    const char *concatpath, unsigned dirty_submodule)
6112{
6113        struct diff_filespec *one, *two;
6114
6115        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6116                return;
6117
6118        /* This may look odd, but it is a preparation for
6119         * feeding "there are unchanged files which should
6120         * not produce diffs, but when you are doing copy
6121         * detection you would need them, so here they are"
6122         * entries to the diff-core.  They will be prefixed
6123         * with something like '=' or '*' (I haven't decided
6124         * which but should not make any difference).
6125         * Feeding the same new and old to diff_change()
6126         * also has the same effect.
6127         * Before the final output happens, they are pruned after
6128         * merged into rename/copy pairs as appropriate.
6129         */
6130        if (options->flags.reverse_diff)
6131                addremove = (addremove == '+' ? '-' :
6132                             addremove == '-' ? '+' : addremove);
6133
6134        if (options->prefix &&
6135            strncmp(concatpath, options->prefix, options->prefix_length))
6136                return;
6137
6138        one = alloc_filespec(concatpath);
6139        two = alloc_filespec(concatpath);
6140
6141        if (addremove != '+')
6142                fill_filespec(one, oid, oid_valid, mode);
6143        if (addremove != '-') {
6144                fill_filespec(two, oid, oid_valid, mode);
6145                two->dirty_submodule = dirty_submodule;
6146        }
6147
6148        diff_queue(&diff_queued_diff, one, two);
6149        if (!options->flags.diff_from_contents)
6150                options->flags.has_changes = 1;
6151}
6152
6153void diff_change(struct diff_options *options,
6154                 unsigned old_mode, unsigned new_mode,
6155                 const struct object_id *old_oid,
6156                 const struct object_id *new_oid,
6157                 int old_oid_valid, int new_oid_valid,
6158                 const char *concatpath,
6159                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6160{
6161        struct diff_filespec *one, *two;
6162        struct diff_filepair *p;
6163
6164        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6165            is_submodule_ignored(concatpath, options))
6166                return;
6167
6168        if (options->flags.reverse_diff) {
6169                SWAP(old_mode, new_mode);
6170                SWAP(old_oid, new_oid);
6171                SWAP(old_oid_valid, new_oid_valid);
6172                SWAP(old_dirty_submodule, new_dirty_submodule);
6173        }
6174
6175        if (options->prefix &&
6176            strncmp(concatpath, options->prefix, options->prefix_length))
6177                return;
6178
6179        one = alloc_filespec(concatpath);
6180        two = alloc_filespec(concatpath);
6181        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6182        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6183        one->dirty_submodule = old_dirty_submodule;
6184        two->dirty_submodule = new_dirty_submodule;
6185        p = diff_queue(&diff_queued_diff, one, two);
6186
6187        if (options->flags.diff_from_contents)
6188                return;
6189
6190        if (options->flags.quick && options->skip_stat_unmatch &&
6191            !diff_filespec_check_stat_unmatch(p))
6192                return;
6193
6194        options->flags.has_changes = 1;
6195}
6196
6197struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6198{
6199        struct diff_filepair *pair;
6200        struct diff_filespec *one, *two;
6201
6202        if (options->prefix &&
6203            strncmp(path, options->prefix, options->prefix_length))
6204                return NULL;
6205
6206        one = alloc_filespec(path);
6207        two = alloc_filespec(path);
6208        pair = diff_queue(&diff_queued_diff, one, two);
6209        pair->is_unmerged = 1;
6210        return pair;
6211}
6212
6213static char *run_textconv(const char *pgm, struct diff_filespec *spec,
6214                size_t *outsize)
6215{
6216        struct diff_tempfile *temp;
6217        const char *argv[3];
6218        const char **arg = argv;
6219        struct child_process child = CHILD_PROCESS_INIT;
6220        struct strbuf buf = STRBUF_INIT;
6221        int err = 0;
6222
6223        temp = prepare_temp_file(spec->path, spec);
6224        *arg++ = pgm;
6225        *arg++ = temp->name;
6226        *arg = NULL;
6227
6228        child.use_shell = 1;
6229        child.argv = argv;
6230        child.out = -1;
6231        if (start_command(&child)) {
6232                remove_tempfile();
6233                return NULL;
6234        }
6235
6236        if (strbuf_read(&buf, child.out, 0) < 0)
6237                err = error("error reading from textconv command '%s'", pgm);
6238        close(child.out);
6239
6240        if (finish_command(&child) || err) {
6241                strbuf_release(&buf);
6242                remove_tempfile();
6243                return NULL;
6244        }
6245        remove_tempfile();
6246
6247        return strbuf_detach(&buf, outsize);
6248}
6249
6250size_t fill_textconv(struct userdiff_driver *driver,
6251                     struct diff_filespec *df,
6252                     char **outbuf)
6253{
6254        size_t size;
6255
6256        if (!driver) {
6257                if (!DIFF_FILE_VALID(df)) {
6258                        *outbuf = "";
6259                        return 0;
6260                }
6261                if (diff_populate_filespec(df, 0))
6262                        die("unable to read files to diff");
6263                *outbuf = df->data;
6264                return df->size;
6265        }
6266
6267        if (!driver->textconv)
6268                BUG("fill_textconv called with non-textconv driver");
6269
6270        if (driver->textconv_cache && df->oid_valid) {
6271                *outbuf = notes_cache_get(driver->textconv_cache,
6272                                          &df->oid,
6273                                          &size);
6274                if (*outbuf)
6275                        return size;
6276        }
6277
6278        *outbuf = run_textconv(driver->textconv, df, &size);
6279        if (!*outbuf)
6280                die("unable to read files to diff");
6281
6282        if (driver->textconv_cache && df->oid_valid) {
6283                /* ignore errors, as we might be in a readonly repository */
6284                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6285                                size);
6286                /*
6287                 * we could save up changes and flush them all at the end,
6288                 * but we would need an extra call after all diffing is done.
6289                 * Since generating a cache entry is the slow path anyway,
6290                 * this extra overhead probably isn't a big deal.
6291                 */
6292                notes_cache_write(driver->textconv_cache);
6293        }
6294
6295        return size;
6296}
6297
6298int textconv_object(const char *path,
6299                    unsigned mode,
6300                    const struct object_id *oid,
6301                    int oid_valid,
6302                    char **buf,
6303                    unsigned long *buf_size)
6304{
6305        struct diff_filespec *df;
6306        struct userdiff_driver *textconv;
6307
6308        df = alloc_filespec(path);
6309        fill_filespec(df, oid, oid_valid, mode);
6310        textconv = get_textconv(df);
6311        if (!textconv) {
6312                free_filespec(df);
6313                return 0;
6314        }
6315
6316        *buf_size = fill_textconv(textconv, df, buf);
6317        free_filespec(df);
6318        return 1;
6319}
6320
6321void setup_diff_pager(struct diff_options *opt)
6322{
6323        /*
6324         * If the user asked for our exit code, then either they want --quiet
6325         * or --exit-code. We should definitely not bother with a pager in the
6326         * former case, as we will generate no output. Since we still properly
6327         * report our exit code even when a pager is run, we _could_ run a
6328         * pager with --exit-code. But since we have not done so historically,
6329         * and because it is easy to find people oneline advising "git diff
6330         * --exit-code" in hooks and other scripts, we do not do so.
6331         */
6332        if (!opt->flags.exit_with_status &&
6333            check_pager_config("diff") != 0)
6334                setup_pager();
6335}