diff.con commit Merge branch 'kg/gc-auto-windows-workaround' (562413e)
   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
 277                return error(_("color moved setting must be one of 'no', 'default', 'blocks', 'zebra', 'dimmed_zebra', 'plain'"));
 278}
 279
 280static int parse_color_moved_ws(const char *arg)
 281{
 282        int ret = 0;
 283        struct string_list l = STRING_LIST_INIT_DUP;
 284        struct string_list_item *i;
 285
 286        string_list_split(&l, arg, ',', -1);
 287
 288        for_each_string_list_item(i, &l) {
 289                struct strbuf sb = STRBUF_INIT;
 290                strbuf_addstr(&sb, i->string);
 291                strbuf_trim(&sb);
 292
 293                if (!strcmp(sb.buf, "ignore-space-change"))
 294                        ret |= XDF_IGNORE_WHITESPACE_CHANGE;
 295                else if (!strcmp(sb.buf, "ignore-space-at-eol"))
 296                        ret |= XDF_IGNORE_WHITESPACE_AT_EOL;
 297                else if (!strcmp(sb.buf, "ignore-all-space"))
 298                        ret |= XDF_IGNORE_WHITESPACE;
 299                else if (!strcmp(sb.buf, "allow-indentation-change"))
 300                        ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
 301                else
 302                        error(_("ignoring unknown color-moved-ws mode '%s'"), sb.buf);
 303
 304                strbuf_release(&sb);
 305        }
 306
 307        if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
 308            (ret & XDF_WHITESPACE_FLAGS))
 309                die(_("color-moved-ws: allow-indentation-change cannot be combined with other white space modes"));
 310
 311        string_list_clear(&l, 0);
 312
 313        return ret;
 314}
 315
 316int git_diff_ui_config(const char *var, const char *value, void *cb)
 317{
 318        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 319                diff_use_color_default = git_config_colorbool(var, value);
 320                return 0;
 321        }
 322        if (!strcmp(var, "diff.colormoved")) {
 323                int cm = parse_color_moved(value);
 324                if (cm < 0)
 325                        return -1;
 326                diff_color_moved_default = cm;
 327                return 0;
 328        }
 329        if (!strcmp(var, "diff.colormovedws")) {
 330                int cm = parse_color_moved_ws(value);
 331                if (cm < 0)
 332                        return -1;
 333                diff_color_moved_ws_default = cm;
 334                return 0;
 335        }
 336        if (!strcmp(var, "diff.context")) {
 337                diff_context_default = git_config_int(var, value);
 338                if (diff_context_default < 0)
 339                        return -1;
 340                return 0;
 341        }
 342        if (!strcmp(var, "diff.interhunkcontext")) {
 343                diff_interhunk_context_default = git_config_int(var, value);
 344                if (diff_interhunk_context_default < 0)
 345                        return -1;
 346                return 0;
 347        }
 348        if (!strcmp(var, "diff.renames")) {
 349                diff_detect_rename_default = git_config_rename(var, value);
 350                return 0;
 351        }
 352        if (!strcmp(var, "diff.autorefreshindex")) {
 353                diff_auto_refresh_index = git_config_bool(var, value);
 354                return 0;
 355        }
 356        if (!strcmp(var, "diff.mnemonicprefix")) {
 357                diff_mnemonic_prefix = git_config_bool(var, value);
 358                return 0;
 359        }
 360        if (!strcmp(var, "diff.noprefix")) {
 361                diff_no_prefix = git_config_bool(var, value);
 362                return 0;
 363        }
 364        if (!strcmp(var, "diff.statgraphwidth")) {
 365                diff_stat_graph_width = git_config_int(var, value);
 366                return 0;
 367        }
 368        if (!strcmp(var, "diff.external"))
 369                return git_config_string(&external_diff_cmd_cfg, var, value);
 370        if (!strcmp(var, "diff.wordregex"))
 371                return git_config_string(&diff_word_regex_cfg, var, value);
 372        if (!strcmp(var, "diff.orderfile"))
 373                return git_config_pathname(&diff_order_file_cfg, var, value);
 374
 375        if (!strcmp(var, "diff.ignoresubmodules"))
 376                handle_ignore_submodules_arg(&default_diff_options, value);
 377
 378        if (!strcmp(var, "diff.submodule")) {
 379                if (parse_submodule_params(&default_diff_options, value))
 380                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 381                                value);
 382                return 0;
 383        }
 384
 385        if (!strcmp(var, "diff.algorithm")) {
 386                diff_algorithm = parse_algorithm_value(value);
 387                if (diff_algorithm < 0)
 388                        return -1;
 389                return 0;
 390        }
 391
 392        if (!strcmp(var, "diff.wserrorhighlight")) {
 393                int val = parse_ws_error_highlight(value);
 394                if (val < 0)
 395                        return -1;
 396                ws_error_highlight_default = val;
 397                return 0;
 398        }
 399
 400        if (git_color_config(var, value, cb) < 0)
 401                return -1;
 402
 403        return git_diff_basic_config(var, value, cb);
 404}
 405
 406int git_diff_basic_config(const char *var, const char *value, void *cb)
 407{
 408        const char *name;
 409
 410        if (!strcmp(var, "diff.renamelimit")) {
 411                diff_rename_limit_default = git_config_int(var, value);
 412                return 0;
 413        }
 414
 415        if (userdiff_config(var, value) < 0)
 416                return -1;
 417
 418        if (skip_prefix(var, "diff.color.", &name) ||
 419            skip_prefix(var, "color.diff.", &name)) {
 420                int slot = parse_diff_color_slot(name);
 421                if (slot < 0)
 422                        return 0;
 423                if (!value)
 424                        return config_error_nonbool(var);
 425                return color_parse(value, diff_colors[slot]);
 426        }
 427
 428        /* like GNU diff's --suppress-blank-empty option  */
 429        if (!strcmp(var, "diff.suppressblankempty") ||
 430                        /* for backwards compatibility */
 431                        !strcmp(var, "diff.suppress-blank-empty")) {
 432                diff_suppress_blank_empty = git_config_bool(var, value);
 433                return 0;
 434        }
 435
 436        if (!strcmp(var, "diff.dirstat")) {
 437                struct strbuf errmsg = STRBUF_INIT;
 438                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 439                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 440                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 441                                errmsg.buf);
 442                strbuf_release(&errmsg);
 443                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 444                return 0;
 445        }
 446
 447        if (git_diff_heuristic_config(var, value, cb) < 0)
 448                return -1;
 449
 450        return git_default_config(var, value, cb);
 451}
 452
 453static char *quote_two(const char *one, const char *two)
 454{
 455        int need_one = quote_c_style(one, NULL, NULL, 1);
 456        int need_two = quote_c_style(two, NULL, NULL, 1);
 457        struct strbuf res = STRBUF_INIT;
 458
 459        if (need_one + need_two) {
 460                strbuf_addch(&res, '"');
 461                quote_c_style(one, &res, NULL, 1);
 462                quote_c_style(two, &res, NULL, 1);
 463                strbuf_addch(&res, '"');
 464        } else {
 465                strbuf_addstr(&res, one);
 466                strbuf_addstr(&res, two);
 467        }
 468        return strbuf_detach(&res, NULL);
 469}
 470
 471static const char *external_diff(void)
 472{
 473        static const char *external_diff_cmd = NULL;
 474        static int done_preparing = 0;
 475
 476        if (done_preparing)
 477                return external_diff_cmd;
 478        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 479        if (!external_diff_cmd)
 480                external_diff_cmd = external_diff_cmd_cfg;
 481        done_preparing = 1;
 482        return external_diff_cmd;
 483}
 484
 485/*
 486 * Keep track of files used for diffing. Sometimes such an entry
 487 * refers to a temporary file, sometimes to an existing file, and
 488 * sometimes to "/dev/null".
 489 */
 490static struct diff_tempfile {
 491        /*
 492         * filename external diff should read from, or NULL if this
 493         * entry is currently not in use:
 494         */
 495        const char *name;
 496
 497        char hex[GIT_MAX_HEXSZ + 1];
 498        char mode[10];
 499
 500        /*
 501         * If this diff_tempfile instance refers to a temporary file,
 502         * this tempfile object is used to manage its lifetime.
 503         */
 504        struct tempfile *tempfile;
 505} diff_temp[2];
 506
 507struct emit_callback {
 508        int color_diff;
 509        unsigned ws_rule;
 510        int blank_at_eof_in_preimage;
 511        int blank_at_eof_in_postimage;
 512        int lno_in_preimage;
 513        int lno_in_postimage;
 514        const char **label_path;
 515        struct diff_words_data *diff_words;
 516        struct diff_options *opt;
 517        struct strbuf *header;
 518};
 519
 520static int count_lines(const char *data, int size)
 521{
 522        int count, ch, completely_empty = 1, nl_just_seen = 0;
 523        count = 0;
 524        while (0 < size--) {
 525                ch = *data++;
 526                if (ch == '\n') {
 527                        count++;
 528                        nl_just_seen = 1;
 529                        completely_empty = 0;
 530                }
 531                else {
 532                        nl_just_seen = 0;
 533                        completely_empty = 0;
 534                }
 535        }
 536        if (completely_empty)
 537                return 0;
 538        if (!nl_just_seen)
 539                count++; /* no trailing newline */
 540        return count;
 541}
 542
 543static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 544{
 545        if (!DIFF_FILE_VALID(one)) {
 546                mf->ptr = (char *)""; /* does not matter */
 547                mf->size = 0;
 548                return 0;
 549        }
 550        else if (diff_populate_filespec(one, 0))
 551                return -1;
 552
 553        mf->ptr = one->data;
 554        mf->size = one->size;
 555        return 0;
 556}
 557
 558/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 559static unsigned long diff_filespec_size(struct diff_filespec *one)
 560{
 561        if (!DIFF_FILE_VALID(one))
 562                return 0;
 563        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 564        return one->size;
 565}
 566
 567static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 568{
 569        char *ptr = mf->ptr;
 570        long size = mf->size;
 571        int cnt = 0;
 572
 573        if (!size)
 574                return cnt;
 575        ptr += size - 1; /* pointing at the very end */
 576        if (*ptr != '\n')
 577                ; /* incomplete line */
 578        else
 579                ptr--; /* skip the last LF */
 580        while (mf->ptr < ptr) {
 581                char *prev_eol;
 582                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 583                        if (*prev_eol == '\n')
 584                                break;
 585                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 586                        break;
 587                cnt++;
 588                ptr = prev_eol - 1;
 589        }
 590        return cnt;
 591}
 592
 593static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 594                               struct emit_callback *ecbdata)
 595{
 596        int l1, l2, at;
 597        unsigned ws_rule = ecbdata->ws_rule;
 598        l1 = count_trailing_blank(mf1, ws_rule);
 599        l2 = count_trailing_blank(mf2, ws_rule);
 600        if (l2 <= l1) {
 601                ecbdata->blank_at_eof_in_preimage = 0;
 602                ecbdata->blank_at_eof_in_postimage = 0;
 603                return;
 604        }
 605        at = count_lines(mf1->ptr, mf1->size);
 606        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 607
 608        at = count_lines(mf2->ptr, mf2->size);
 609        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 610}
 611
 612static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 613                        int first, const char *line, int len)
 614{
 615        int has_trailing_newline, has_trailing_carriage_return;
 616        int nofirst;
 617        FILE *file = o->file;
 618
 619        fputs(diff_line_prefix(o), file);
 620
 621        if (len == 0) {
 622                has_trailing_newline = (first == '\n');
 623                has_trailing_carriage_return = (!has_trailing_newline &&
 624                                                (first == '\r'));
 625                nofirst = has_trailing_newline || has_trailing_carriage_return;
 626        } else {
 627                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 628                if (has_trailing_newline)
 629                        len--;
 630                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 631                if (has_trailing_carriage_return)
 632                        len--;
 633                nofirst = 0;
 634        }
 635
 636        if (len || !nofirst) {
 637                fputs(set, file);
 638                if (!nofirst)
 639                        fputc(first, file);
 640                fwrite(line, len, 1, file);
 641                fputs(reset, file);
 642        }
 643        if (has_trailing_carriage_return)
 644                fputc('\r', file);
 645        if (has_trailing_newline)
 646                fputc('\n', file);
 647}
 648
 649static void emit_line(struct diff_options *o, const char *set, const char *reset,
 650                      const char *line, int len)
 651{
 652        emit_line_0(o, set, reset, line[0], line+1, len-1);
 653}
 654
 655enum diff_symbol {
 656        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 657        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 658        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 659        DIFF_SYMBOL_BINARY_DIFF_BODY,
 660        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 661        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 662        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 663        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 664        DIFF_SYMBOL_STATS_LINE,
 665        DIFF_SYMBOL_WORD_DIFF,
 666        DIFF_SYMBOL_STAT_SEP,
 667        DIFF_SYMBOL_SUMMARY,
 668        DIFF_SYMBOL_SUBMODULE_ADD,
 669        DIFF_SYMBOL_SUBMODULE_DEL,
 670        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 671        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 672        DIFF_SYMBOL_SUBMODULE_HEADER,
 673        DIFF_SYMBOL_SUBMODULE_ERROR,
 674        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 675        DIFF_SYMBOL_REWRITE_DIFF,
 676        DIFF_SYMBOL_BINARY_FILES,
 677        DIFF_SYMBOL_HEADER,
 678        DIFF_SYMBOL_FILEPAIR_PLUS,
 679        DIFF_SYMBOL_FILEPAIR_MINUS,
 680        DIFF_SYMBOL_WORDS_PORCELAIN,
 681        DIFF_SYMBOL_WORDS,
 682        DIFF_SYMBOL_CONTEXT,
 683        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 684        DIFF_SYMBOL_PLUS,
 685        DIFF_SYMBOL_MINUS,
 686        DIFF_SYMBOL_NO_LF_EOF,
 687        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 688        DIFF_SYMBOL_CONTEXT_MARKER,
 689        DIFF_SYMBOL_SEPARATOR
 690};
 691/*
 692 * Flags for content lines:
 693 * 0..12 are whitespace rules
 694 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 695 * 16 is marking if the line is blank at EOF
 696 */
 697#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 698#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 699#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 700#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 701#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 702
 703/*
 704 * This struct is used when we need to buffer the output of the diff output.
 705 *
 706 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 707 * into the pre/post image file. This pointer could be a union with the
 708 * line pointer. By storing an offset into the file instead of the literal line,
 709 * we can decrease the memory footprint for the buffered output. At first we
 710 * may want to only have indirection for the content lines, but we could also
 711 * enhance the state for emitting prefabricated lines, e.g. the similarity
 712 * score line or hunk/file headers would only need to store a number or path
 713 * and then the output can be constructed later on depending on state.
 714 */
 715struct emitted_diff_symbol {
 716        const char *line;
 717        int len;
 718        int flags;
 719        enum diff_symbol s;
 720};
 721#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 722
 723struct emitted_diff_symbols {
 724        struct emitted_diff_symbol *buf;
 725        int nr, alloc;
 726};
 727#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 728
 729static void append_emitted_diff_symbol(struct diff_options *o,
 730                                       struct emitted_diff_symbol *e)
 731{
 732        struct emitted_diff_symbol *f;
 733
 734        ALLOC_GROW(o->emitted_symbols->buf,
 735                   o->emitted_symbols->nr + 1,
 736                   o->emitted_symbols->alloc);
 737        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 738
 739        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 740        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 741}
 742
 743struct moved_entry {
 744        struct hashmap_entry ent;
 745        const struct emitted_diff_symbol *es;
 746        struct moved_entry *next_line;
 747        struct ws_delta *wsd;
 748};
 749
 750/**
 751 * The struct ws_delta holds white space differences between moved lines, i.e.
 752 * between '+' and '-' lines that have been detected to be a move.
 753 * The string contains the difference in leading white spaces, before the
 754 * rest of the line is compared using the white space config for move
 755 * coloring. The current_longer indicates if the first string in the
 756 * comparision is longer than the second.
 757 */
 758struct ws_delta {
 759        char *string;
 760        unsigned int current_longer : 1;
 761};
 762#define WS_DELTA_INIT { NULL, 0 }
 763
 764static int compute_ws_delta(const struct emitted_diff_symbol *a,
 765                             const struct emitted_diff_symbol *b,
 766                             struct ws_delta *out)
 767{
 768        const struct emitted_diff_symbol *longer =  a->len > b->len ? a : b;
 769        const struct emitted_diff_symbol *shorter = a->len > b->len ? b : a;
 770        int d = longer->len - shorter->len;
 771
 772        out->string = xmemdupz(longer->line, d);
 773        out->current_longer = (a == longer);
 774
 775        return !strncmp(longer->line + d, shorter->line, shorter->len);
 776}
 777
 778static int cmp_in_block_with_wsd(const struct diff_options *o,
 779                                 const struct moved_entry *cur,
 780                                 const struct moved_entry *match,
 781                                 struct moved_entry *pmb,
 782                                 int n)
 783{
 784        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 785        int al = cur->es->len, cl = l->len;
 786        const char *a = cur->es->line,
 787                   *b = match->es->line,
 788                   *c = l->line;
 789
 790        int wslen;
 791
 792        /*
 793         * We need to check if 'cur' is equal to 'match'.
 794         * As those are from the same (+/-) side, we do not need to adjust for
 795         * indent changes. However these were found using fuzzy matching
 796         * so we do have to check if they are equal.
 797         */
 798        if (strcmp(a, b))
 799                return 1;
 800
 801        if (!pmb->wsd)
 802                /*
 803                 * No white space delta was carried forward? This can happen
 804                 * when we exit early in this function and do not carry
 805                 * forward ws.
 806                 */
 807                return 1;
 808
 809        /*
 810         * The indent changes of the block are known and carried forward in
 811         * pmb->wsd; however we need to check if the indent changes of the
 812         * current line are still the same as before.
 813         *
 814         * To do so we need to compare 'l' to 'cur', adjusting the
 815         * one of them for the white spaces, depending which was longer.
 816         */
 817
 818        wslen = strlen(pmb->wsd->string);
 819        if (pmb->wsd->current_longer) {
 820                c += wslen;
 821                cl -= wslen;
 822        } else {
 823                a += wslen;
 824                al -= wslen;
 825        }
 826
 827        if (strcmp(a, c))
 828                return 1;
 829
 830        return 0;
 831}
 832
 833static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 834                           const void *entry,
 835                           const void *entry_or_key,
 836                           const void *keydata)
 837{
 838        const struct diff_options *diffopt = hashmap_cmp_fn_data;
 839        const struct moved_entry *a = entry;
 840        const struct moved_entry *b = entry_or_key;
 841        unsigned flags = diffopt->color_moved_ws_handling
 842                         & XDF_WHITESPACE_FLAGS;
 843
 844        if (diffopt->color_moved_ws_handling &
 845            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 846                /*
 847                 * As there is not specific white space config given,
 848                 * we'd need to check for a new block, so ignore all
 849                 * white space. The setup of the white space
 850                 * configuration for the next block is done else where
 851                 */
 852                flags |= XDF_IGNORE_WHITESPACE;
 853
 854        return !xdiff_compare_lines(a->es->line, a->es->len,
 855                                    b->es->line, b->es->len,
 856                                    flags);
 857}
 858
 859static struct moved_entry *prepare_entry(struct diff_options *o,
 860                                         int line_no)
 861{
 862        struct moved_entry *ret = xmalloc(sizeof(*ret));
 863        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 864        unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 865
 866        ret->ent.hash = xdiff_hash_string(l->line, l->len, flags);
 867        ret->es = l;
 868        ret->next_line = NULL;
 869        ret->wsd = NULL;
 870
 871        return ret;
 872}
 873
 874static void add_lines_to_move_detection(struct diff_options *o,
 875                                        struct hashmap *add_lines,
 876                                        struct hashmap *del_lines)
 877{
 878        struct moved_entry *prev_line = NULL;
 879
 880        int n;
 881        for (n = 0; n < o->emitted_symbols->nr; n++) {
 882                struct hashmap *hm;
 883                struct moved_entry *key;
 884
 885                switch (o->emitted_symbols->buf[n].s) {
 886                case DIFF_SYMBOL_PLUS:
 887                        hm = add_lines;
 888                        break;
 889                case DIFF_SYMBOL_MINUS:
 890                        hm = del_lines;
 891                        break;
 892                default:
 893                        prev_line = NULL;
 894                        continue;
 895                }
 896
 897                key = prepare_entry(o, n);
 898                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 899                        prev_line->next_line = key;
 900
 901                hashmap_add(hm, key);
 902                prev_line = key;
 903        }
 904}
 905
 906static void pmb_advance_or_null(struct diff_options *o,
 907                                struct moved_entry *match,
 908                                struct hashmap *hm,
 909                                struct moved_entry **pmb,
 910                                int pmb_nr)
 911{
 912        int i;
 913        for (i = 0; i < pmb_nr; i++) {
 914                struct moved_entry *prev = pmb[i];
 915                struct moved_entry *cur = (prev && prev->next_line) ?
 916                                prev->next_line : NULL;
 917                if (cur && !hm->cmpfn(o, cur, match, NULL)) {
 918                        pmb[i] = cur;
 919                } else {
 920                        pmb[i] = NULL;
 921                }
 922        }
 923}
 924
 925static void pmb_advance_or_null_multi_match(struct diff_options *o,
 926                                            struct moved_entry *match,
 927                                            struct hashmap *hm,
 928                                            struct moved_entry **pmb,
 929                                            int pmb_nr, int n)
 930{
 931        int i;
 932        char *got_match = xcalloc(1, pmb_nr);
 933
 934        for (; match; match = hashmap_get_next(hm, match)) {
 935                for (i = 0; i < pmb_nr; i++) {
 936                        struct moved_entry *prev = pmb[i];
 937                        struct moved_entry *cur = (prev && prev->next_line) ?
 938                                        prev->next_line : NULL;
 939                        if (!cur)
 940                                continue;
 941                        if (!cmp_in_block_with_wsd(o, cur, match, pmb[i], n))
 942                                got_match[i] |= 1;
 943                }
 944        }
 945
 946        for (i = 0; i < pmb_nr; i++) {
 947                if (got_match[i]) {
 948                        /* Carry the white space delta forward */
 949                        pmb[i]->next_line->wsd = pmb[i]->wsd;
 950                        pmb[i] = pmb[i]->next_line;
 951                } else
 952                        pmb[i] = NULL;
 953        }
 954}
 955
 956static int shrink_potential_moved_blocks(struct moved_entry **pmb,
 957                                         int pmb_nr)
 958{
 959        int lp, rp;
 960
 961        /* Shrink the set of potential block to the remaining running */
 962        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
 963                while (lp < pmb_nr && pmb[lp])
 964                        lp++;
 965                /* lp points at the first NULL now */
 966
 967                while (rp > -1 && !pmb[rp])
 968                        rp--;
 969                /* rp points at the last non-NULL */
 970
 971                if (lp < pmb_nr && rp > -1 && lp < rp) {
 972                        pmb[lp] = pmb[rp];
 973                        if (pmb[rp]->wsd) {
 974                                free(pmb[rp]->wsd->string);
 975                                FREE_AND_NULL(pmb[rp]->wsd);
 976                        }
 977                        pmb[rp] = NULL;
 978                        rp--;
 979                        lp++;
 980                }
 981        }
 982
 983        /* Remember the number of running sets */
 984        return rp + 1;
 985}
 986
 987/*
 988 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
 989 *
 990 * Otherwise, if the last block has fewer alphanumeric characters than
 991 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
 992 * that block.
 993 *
 994 * The last block consists of the (n - block_length)'th line up to but not
 995 * including the nth line.
 996 *
 997 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
 998 * Think of a way to unify them.
 999 */
1000static void adjust_last_block(struct diff_options *o, int n, int block_length)
1001{
1002        int i, alnum_count = 0;
1003        if (o->color_moved == COLOR_MOVED_PLAIN)
1004                return;
1005        for (i = 1; i < block_length + 1; i++) {
1006                const char *c = o->emitted_symbols->buf[n - i].line;
1007                for (; *c; c++) {
1008                        if (!isalnum(*c))
1009                                continue;
1010                        alnum_count++;
1011                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
1012                                return;
1013                }
1014        }
1015        for (i = 1; i < block_length + 1; i++)
1016                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
1017}
1018
1019/* Find blocks of moved code, delegate actual coloring decision to helper */
1020static void mark_color_as_moved(struct diff_options *o,
1021                                struct hashmap *add_lines,
1022                                struct hashmap *del_lines)
1023{
1024        struct moved_entry **pmb = NULL; /* potentially moved blocks */
1025        int pmb_nr = 0, pmb_alloc = 0;
1026        int n, flipped_block = 1, block_length = 0;
1027
1028
1029        for (n = 0; n < o->emitted_symbols->nr; n++) {
1030                struct hashmap *hm = NULL;
1031                struct moved_entry *key;
1032                struct moved_entry *match = NULL;
1033                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1034
1035                switch (l->s) {
1036                case DIFF_SYMBOL_PLUS:
1037                        hm = del_lines;
1038                        key = prepare_entry(o, n);
1039                        match = hashmap_get(hm, key, NULL);
1040                        free(key);
1041                        break;
1042                case DIFF_SYMBOL_MINUS:
1043                        hm = add_lines;
1044                        key = prepare_entry(o, n);
1045                        match = hashmap_get(hm, key, NULL);
1046                        free(key);
1047                        break;
1048                default:
1049                        flipped_block = 1;
1050                }
1051
1052                if (!match) {
1053                        adjust_last_block(o, n, block_length);
1054                        pmb_nr = 0;
1055                        block_length = 0;
1056                        continue;
1057                }
1058
1059                l->flags |= DIFF_SYMBOL_MOVED_LINE;
1060
1061                if (o->color_moved == COLOR_MOVED_PLAIN)
1062                        continue;
1063
1064                if (o->color_moved_ws_handling &
1065                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1066                        pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
1067                else
1068                        pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
1069
1070                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
1071
1072                if (pmb_nr == 0) {
1073                        /*
1074                         * The current line is the start of a new block.
1075                         * Setup the set of potential blocks.
1076                         */
1077                        for (; match; match = hashmap_get_next(hm, match)) {
1078                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
1079                                if (o->color_moved_ws_handling &
1080                                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
1081                                        struct ws_delta *wsd = xmalloc(sizeof(*match->wsd));
1082                                        if (compute_ws_delta(l, match->es, wsd)) {
1083                                                match->wsd = wsd;
1084                                                pmb[pmb_nr++] = match;
1085                                        } else
1086                                                free(wsd);
1087                                } else {
1088                                        pmb[pmb_nr++] = match;
1089                                }
1090                        }
1091
1092                        flipped_block = (flipped_block + 1) % 2;
1093
1094                        adjust_last_block(o, n, block_length);
1095                        block_length = 0;
1096                }
1097
1098                block_length++;
1099
1100                if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
1101                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
1102        }
1103        adjust_last_block(o, n, block_length);
1104
1105        free(pmb);
1106}
1107
1108#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
1109  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
1110static void dim_moved_lines(struct diff_options *o)
1111{
1112        int n;
1113        for (n = 0; n < o->emitted_symbols->nr; n++) {
1114                struct emitted_diff_symbol *prev = (n != 0) ?
1115                                &o->emitted_symbols->buf[n - 1] : NULL;
1116                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1117                struct emitted_diff_symbol *next =
1118                                (n < o->emitted_symbols->nr - 1) ?
1119                                &o->emitted_symbols->buf[n + 1] : NULL;
1120
1121                /* Not a plus or minus line? */
1122                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
1123                        continue;
1124
1125                /* Not a moved line? */
1126                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
1127                        continue;
1128
1129                /*
1130                 * If prev or next are not a plus or minus line,
1131                 * pretend they don't exist
1132                 */
1133                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1134                            prev->s != DIFF_SYMBOL_MINUS)
1135                        prev = NULL;
1136                if (next && next->s != DIFF_SYMBOL_PLUS &&
1137                            next->s != DIFF_SYMBOL_MINUS)
1138                        next = NULL;
1139
1140                /* Inside a block? */
1141                if ((prev &&
1142                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1143                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1144                    (next &&
1145                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1146                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1147                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1148                        continue;
1149                }
1150
1151                /* Check if we are at an interesting bound: */
1152                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1153                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1154                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1155                        continue;
1156                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1157                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1158                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1159                        continue;
1160
1161                /*
1162                 * The boundary to prev and next are not interesting,
1163                 * so this line is not interesting as a whole
1164                 */
1165                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1166        }
1167}
1168
1169static void emit_line_ws_markup(struct diff_options *o,
1170                                const char *set, const char *reset,
1171                                const char *line, int len, char sign,
1172                                unsigned ws_rule, int blank_at_eof)
1173{
1174        const char *ws = NULL;
1175
1176        if (o->ws_error_highlight & ws_rule) {
1177                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1178                if (!*ws)
1179                        ws = NULL;
1180        }
1181
1182        if (!ws)
1183                emit_line_0(o, set, reset, sign, line, len);
1184        else if (blank_at_eof)
1185                /* Blank line at EOF - paint '+' as well */
1186                emit_line_0(o, ws, reset, sign, line, len);
1187        else {
1188                /* Emit just the prefix, then the rest. */
1189                emit_line_0(o, set, reset, sign, "", 0);
1190                ws_check_emit(line, len, ws_rule,
1191                              o->file, set, reset, ws);
1192        }
1193}
1194
1195static void emit_diff_symbol_from_struct(struct diff_options *o,
1196                                         struct emitted_diff_symbol *eds)
1197{
1198        static const char *nneof = " No newline at end of file\n";
1199        const char *context, *reset, *set, *meta, *fraginfo;
1200        struct strbuf sb = STRBUF_INIT;
1201
1202        enum diff_symbol s = eds->s;
1203        const char *line = eds->line;
1204        int len = eds->len;
1205        unsigned flags = eds->flags;
1206
1207        switch (s) {
1208        case DIFF_SYMBOL_NO_LF_EOF:
1209                context = diff_get_color_opt(o, DIFF_CONTEXT);
1210                reset = diff_get_color_opt(o, DIFF_RESET);
1211                putc('\n', o->file);
1212                emit_line_0(o, context, reset, '\\',
1213                            nneof, strlen(nneof));
1214                break;
1215        case DIFF_SYMBOL_SUBMODULE_HEADER:
1216        case DIFF_SYMBOL_SUBMODULE_ERROR:
1217        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1218        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1219        case DIFF_SYMBOL_SUMMARY:
1220        case DIFF_SYMBOL_STATS_LINE:
1221        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1222        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1223                emit_line(o, "", "", line, len);
1224                break;
1225        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1226        case DIFF_SYMBOL_CONTEXT_MARKER:
1227                context = diff_get_color_opt(o, DIFF_CONTEXT);
1228                reset = diff_get_color_opt(o, DIFF_RESET);
1229                emit_line(o, context, reset, line, len);
1230                break;
1231        case DIFF_SYMBOL_SEPARATOR:
1232                fprintf(o->file, "%s%c",
1233                        diff_line_prefix(o),
1234                        o->line_termination);
1235                break;
1236        case DIFF_SYMBOL_CONTEXT:
1237                set = diff_get_color_opt(o, DIFF_CONTEXT);
1238                reset = diff_get_color_opt(o, DIFF_RESET);
1239                emit_line_ws_markup(o, set, reset, line, len, ' ',
1240                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1241                break;
1242        case DIFF_SYMBOL_PLUS:
1243                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1244                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1245                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1246                case DIFF_SYMBOL_MOVED_LINE |
1247                     DIFF_SYMBOL_MOVED_LINE_ALT |
1248                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1249                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1250                        break;
1251                case DIFF_SYMBOL_MOVED_LINE |
1252                     DIFF_SYMBOL_MOVED_LINE_ALT:
1253                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1254                        break;
1255                case DIFF_SYMBOL_MOVED_LINE |
1256                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1257                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1258                        break;
1259                case DIFF_SYMBOL_MOVED_LINE:
1260                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1261                        break;
1262                default:
1263                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1264                }
1265                reset = diff_get_color_opt(o, DIFF_RESET);
1266                emit_line_ws_markup(o, set, reset, line, len, '+',
1267                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1268                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1269                break;
1270        case DIFF_SYMBOL_MINUS:
1271                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1272                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1273                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1274                case DIFF_SYMBOL_MOVED_LINE |
1275                     DIFF_SYMBOL_MOVED_LINE_ALT |
1276                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1277                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1278                        break;
1279                case DIFF_SYMBOL_MOVED_LINE |
1280                     DIFF_SYMBOL_MOVED_LINE_ALT:
1281                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1282                        break;
1283                case DIFF_SYMBOL_MOVED_LINE |
1284                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1285                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1286                        break;
1287                case DIFF_SYMBOL_MOVED_LINE:
1288                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1289                        break;
1290                default:
1291                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1292                }
1293                reset = diff_get_color_opt(o, DIFF_RESET);
1294                emit_line_ws_markup(o, set, reset, line, len, '-',
1295                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1296                break;
1297        case DIFF_SYMBOL_WORDS_PORCELAIN:
1298                context = diff_get_color_opt(o, DIFF_CONTEXT);
1299                reset = diff_get_color_opt(o, DIFF_RESET);
1300                emit_line(o, context, reset, line, len);
1301                fputs("~\n", o->file);
1302                break;
1303        case DIFF_SYMBOL_WORDS:
1304                context = diff_get_color_opt(o, DIFF_CONTEXT);
1305                reset = diff_get_color_opt(o, DIFF_RESET);
1306                /*
1307                 * Skip the prefix character, if any.  With
1308                 * diff_suppress_blank_empty, there may be
1309                 * none.
1310                 */
1311                if (line[0] != '\n') {
1312                        line++;
1313                        len--;
1314                }
1315                emit_line(o, context, reset, line, len);
1316                break;
1317        case DIFF_SYMBOL_FILEPAIR_PLUS:
1318                meta = diff_get_color_opt(o, DIFF_METAINFO);
1319                reset = diff_get_color_opt(o, DIFF_RESET);
1320                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1321                        line, reset,
1322                        strchr(line, ' ') ? "\t" : "");
1323                break;
1324        case DIFF_SYMBOL_FILEPAIR_MINUS:
1325                meta = diff_get_color_opt(o, DIFF_METAINFO);
1326                reset = diff_get_color_opt(o, DIFF_RESET);
1327                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1328                        line, reset,
1329                        strchr(line, ' ') ? "\t" : "");
1330                break;
1331        case DIFF_SYMBOL_BINARY_FILES:
1332        case DIFF_SYMBOL_HEADER:
1333                fprintf(o->file, "%s", line);
1334                break;
1335        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1336                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1337                break;
1338        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1339                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1340                break;
1341        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1342                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1343                break;
1344        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1345                fputs(diff_line_prefix(o), o->file);
1346                fputc('\n', o->file);
1347                break;
1348        case DIFF_SYMBOL_REWRITE_DIFF:
1349                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1350                reset = diff_get_color_opt(o, DIFF_RESET);
1351                emit_line(o, fraginfo, reset, line, len);
1352                break;
1353        case DIFF_SYMBOL_SUBMODULE_ADD:
1354                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1355                reset = diff_get_color_opt(o, DIFF_RESET);
1356                emit_line(o, set, reset, line, len);
1357                break;
1358        case DIFF_SYMBOL_SUBMODULE_DEL:
1359                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1360                reset = diff_get_color_opt(o, DIFF_RESET);
1361                emit_line(o, set, reset, line, len);
1362                break;
1363        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1364                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1365                        diff_line_prefix(o), line);
1366                break;
1367        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1368                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1369                        diff_line_prefix(o), line);
1370                break;
1371        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1372                emit_line(o, "", "", " 0 files changed\n",
1373                          strlen(" 0 files changed\n"));
1374                break;
1375        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1376                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1377                break;
1378        case DIFF_SYMBOL_WORD_DIFF:
1379                fprintf(o->file, "%.*s", len, line);
1380                break;
1381        case DIFF_SYMBOL_STAT_SEP:
1382                fputs(o->stat_sep, o->file);
1383                break;
1384        default:
1385                BUG("unknown diff symbol");
1386        }
1387        strbuf_release(&sb);
1388}
1389
1390static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1391                             const char *line, int len, unsigned flags)
1392{
1393        struct emitted_diff_symbol e = {line, len, flags, s};
1394
1395        if (o->emitted_symbols)
1396                append_emitted_diff_symbol(o, &e);
1397        else
1398                emit_diff_symbol_from_struct(o, &e);
1399}
1400
1401void diff_emit_submodule_del(struct diff_options *o, const char *line)
1402{
1403        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1404}
1405
1406void diff_emit_submodule_add(struct diff_options *o, const char *line)
1407{
1408        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1409}
1410
1411void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1412{
1413        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1414                         path, strlen(path), 0);
1415}
1416
1417void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1418{
1419        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1420                         path, strlen(path), 0);
1421}
1422
1423void diff_emit_submodule_header(struct diff_options *o, const char *header)
1424{
1425        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1426                         header, strlen(header), 0);
1427}
1428
1429void diff_emit_submodule_error(struct diff_options *o, const char *err)
1430{
1431        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1432}
1433
1434void diff_emit_submodule_pipethrough(struct diff_options *o,
1435                                     const char *line, int len)
1436{
1437        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1438}
1439
1440static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1441{
1442        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1443              ecbdata->blank_at_eof_in_preimage &&
1444              ecbdata->blank_at_eof_in_postimage &&
1445              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1446              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1447                return 0;
1448        return ws_blank_line(line, len, ecbdata->ws_rule);
1449}
1450
1451static void emit_add_line(const char *reset,
1452                          struct emit_callback *ecbdata,
1453                          const char *line, int len)
1454{
1455        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1456        if (new_blank_line_at_eof(ecbdata, line, len))
1457                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1458
1459        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1460}
1461
1462static void emit_del_line(const char *reset,
1463                          struct emit_callback *ecbdata,
1464                          const char *line, int len)
1465{
1466        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1467        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1468}
1469
1470static void emit_context_line(const char *reset,
1471                              struct emit_callback *ecbdata,
1472                              const char *line, int len)
1473{
1474        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1475        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1476}
1477
1478static void emit_hunk_header(struct emit_callback *ecbdata,
1479                             const char *line, int len)
1480{
1481        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1482        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1483        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1484        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1485        static const char atat[2] = { '@', '@' };
1486        const char *cp, *ep;
1487        struct strbuf msgbuf = STRBUF_INIT;
1488        int org_len = len;
1489        int i = 1;
1490
1491        /*
1492         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1493         * it always is at least 10 bytes long.
1494         */
1495        if (len < 10 ||
1496            memcmp(line, atat, 2) ||
1497            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1498                emit_diff_symbol(ecbdata->opt,
1499                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1500                return;
1501        }
1502        ep += 2; /* skip over @@ */
1503
1504        /* The hunk header in fraginfo color */
1505        strbuf_addstr(&msgbuf, frag);
1506        strbuf_add(&msgbuf, line, ep - line);
1507        strbuf_addstr(&msgbuf, reset);
1508
1509        /*
1510         * trailing "\r\n"
1511         */
1512        for ( ; i < 3; i++)
1513                if (line[len - i] == '\r' || line[len - i] == '\n')
1514                        len--;
1515
1516        /* blank before the func header */
1517        for (cp = ep; ep - line < len; ep++)
1518                if (*ep != ' ' && *ep != '\t')
1519                        break;
1520        if (ep != cp) {
1521                strbuf_addstr(&msgbuf, context);
1522                strbuf_add(&msgbuf, cp, ep - cp);
1523                strbuf_addstr(&msgbuf, reset);
1524        }
1525
1526        if (ep < line + len) {
1527                strbuf_addstr(&msgbuf, func);
1528                strbuf_add(&msgbuf, ep, line + len - ep);
1529                strbuf_addstr(&msgbuf, reset);
1530        }
1531
1532        strbuf_add(&msgbuf, line + len, org_len - len);
1533        strbuf_complete_line(&msgbuf);
1534        emit_diff_symbol(ecbdata->opt,
1535                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1536        strbuf_release(&msgbuf);
1537}
1538
1539static struct diff_tempfile *claim_diff_tempfile(void) {
1540        int i;
1541        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1542                if (!diff_temp[i].name)
1543                        return diff_temp + i;
1544        BUG("diff is failing to clean up its tempfiles");
1545}
1546
1547static void remove_tempfile(void)
1548{
1549        int i;
1550        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1551                if (is_tempfile_active(diff_temp[i].tempfile))
1552                        delete_tempfile(&diff_temp[i].tempfile);
1553                diff_temp[i].name = NULL;
1554        }
1555}
1556
1557static void add_line_count(struct strbuf *out, int count)
1558{
1559        switch (count) {
1560        case 0:
1561                strbuf_addstr(out, "0,0");
1562                break;
1563        case 1:
1564                strbuf_addstr(out, "1");
1565                break;
1566        default:
1567                strbuf_addf(out, "1,%d", count);
1568                break;
1569        }
1570}
1571
1572static void emit_rewrite_lines(struct emit_callback *ecb,
1573                               int prefix, const char *data, int size)
1574{
1575        const char *endp = NULL;
1576        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1577
1578        while (0 < size) {
1579                int len;
1580
1581                endp = memchr(data, '\n', size);
1582                len = endp ? (endp - data + 1) : size;
1583                if (prefix != '+') {
1584                        ecb->lno_in_preimage++;
1585                        emit_del_line(reset, ecb, data, len);
1586                } else {
1587                        ecb->lno_in_postimage++;
1588                        emit_add_line(reset, ecb, data, len);
1589                }
1590                size -= len;
1591                data += len;
1592        }
1593        if (!endp)
1594                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1595}
1596
1597static void emit_rewrite_diff(const char *name_a,
1598                              const char *name_b,
1599                              struct diff_filespec *one,
1600                              struct diff_filespec *two,
1601                              struct userdiff_driver *textconv_one,
1602                              struct userdiff_driver *textconv_two,
1603                              struct diff_options *o)
1604{
1605        int lc_a, lc_b;
1606        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1607        const char *a_prefix, *b_prefix;
1608        char *data_one, *data_two;
1609        size_t size_one, size_two;
1610        struct emit_callback ecbdata;
1611        struct strbuf out = STRBUF_INIT;
1612
1613        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1614                a_prefix = o->b_prefix;
1615                b_prefix = o->a_prefix;
1616        } else {
1617                a_prefix = o->a_prefix;
1618                b_prefix = o->b_prefix;
1619        }
1620
1621        name_a += (*name_a == '/');
1622        name_b += (*name_b == '/');
1623
1624        strbuf_reset(&a_name);
1625        strbuf_reset(&b_name);
1626        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1627        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1628
1629        size_one = fill_textconv(textconv_one, one, &data_one);
1630        size_two = fill_textconv(textconv_two, two, &data_two);
1631
1632        memset(&ecbdata, 0, sizeof(ecbdata));
1633        ecbdata.color_diff = want_color(o->use_color);
1634        ecbdata.ws_rule = whitespace_rule(name_b);
1635        ecbdata.opt = o;
1636        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1637                mmfile_t mf1, mf2;
1638                mf1.ptr = (char *)data_one;
1639                mf2.ptr = (char *)data_two;
1640                mf1.size = size_one;
1641                mf2.size = size_two;
1642                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1643        }
1644        ecbdata.lno_in_preimage = 1;
1645        ecbdata.lno_in_postimage = 1;
1646
1647        lc_a = count_lines(data_one, size_one);
1648        lc_b = count_lines(data_two, size_two);
1649
1650        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1651                         a_name.buf, a_name.len, 0);
1652        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1653                         b_name.buf, b_name.len, 0);
1654
1655        strbuf_addstr(&out, "@@ -");
1656        if (!o->irreversible_delete)
1657                add_line_count(&out, lc_a);
1658        else
1659                strbuf_addstr(&out, "?,?");
1660        strbuf_addstr(&out, " +");
1661        add_line_count(&out, lc_b);
1662        strbuf_addstr(&out, " @@\n");
1663        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1664        strbuf_release(&out);
1665
1666        if (lc_a && !o->irreversible_delete)
1667                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1668        if (lc_b)
1669                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1670        if (textconv_one)
1671                free((char *)data_one);
1672        if (textconv_two)
1673                free((char *)data_two);
1674}
1675
1676struct diff_words_buffer {
1677        mmfile_t text;
1678        unsigned long alloc;
1679        struct diff_words_orig {
1680                const char *begin, *end;
1681        } *orig;
1682        int orig_nr, orig_alloc;
1683};
1684
1685static void diff_words_append(char *line, unsigned long len,
1686                struct diff_words_buffer *buffer)
1687{
1688        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1689        line++;
1690        len--;
1691        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1692        buffer->text.size += len;
1693        buffer->text.ptr[buffer->text.size] = '\0';
1694}
1695
1696struct diff_words_style_elem {
1697        const char *prefix;
1698        const char *suffix;
1699        const char *color; /* NULL; filled in by the setup code if
1700                            * color is enabled */
1701};
1702
1703struct diff_words_style {
1704        enum diff_words_type type;
1705        struct diff_words_style_elem new_word, old_word, ctx;
1706        const char *newline;
1707};
1708
1709static struct diff_words_style diff_words_styles[] = {
1710        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1711        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1712        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1713};
1714
1715struct diff_words_data {
1716        struct diff_words_buffer minus, plus;
1717        const char *current_plus;
1718        int last_minus;
1719        struct diff_options *opt;
1720        regex_t *word_regex;
1721        enum diff_words_type type;
1722        struct diff_words_style *style;
1723};
1724
1725static int fn_out_diff_words_write_helper(struct diff_options *o,
1726                                          struct diff_words_style_elem *st_el,
1727                                          const char *newline,
1728                                          size_t count, const char *buf)
1729{
1730        int print = 0;
1731        struct strbuf sb = STRBUF_INIT;
1732
1733        while (count) {
1734                char *p = memchr(buf, '\n', count);
1735                if (print)
1736                        strbuf_addstr(&sb, diff_line_prefix(o));
1737
1738                if (p != buf) {
1739                        const char *reset = st_el->color && *st_el->color ?
1740                                            GIT_COLOR_RESET : NULL;
1741                        if (st_el->color && *st_el->color)
1742                                strbuf_addstr(&sb, st_el->color);
1743                        strbuf_addstr(&sb, st_el->prefix);
1744                        strbuf_add(&sb, buf, p ? p - buf : count);
1745                        strbuf_addstr(&sb, st_el->suffix);
1746                        if (reset)
1747                                strbuf_addstr(&sb, reset);
1748                }
1749                if (!p)
1750                        goto out;
1751
1752                strbuf_addstr(&sb, newline);
1753                count -= p + 1 - buf;
1754                buf = p + 1;
1755                print = 1;
1756                if (count) {
1757                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1758                                         sb.buf, sb.len, 0);
1759                        strbuf_reset(&sb);
1760                }
1761        }
1762
1763out:
1764        if (sb.len)
1765                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1766                                 sb.buf, sb.len, 0);
1767        strbuf_release(&sb);
1768        return 0;
1769}
1770
1771/*
1772 * '--color-words' algorithm can be described as:
1773 *
1774 *   1. collect the minus/plus lines of a diff hunk, divided into
1775 *      minus-lines and plus-lines;
1776 *
1777 *   2. break both minus-lines and plus-lines into words and
1778 *      place them into two mmfile_t with one word for each line;
1779 *
1780 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1781 *
1782 * And for the common parts of the both file, we output the plus side text.
1783 * diff_words->current_plus is used to trace the current position of the plus file
1784 * which printed. diff_words->last_minus is used to trace the last minus word
1785 * printed.
1786 *
1787 * For '--graph' to work with '--color-words', we need to output the graph prefix
1788 * on each line of color words output. Generally, there are two conditions on
1789 * which we should output the prefix.
1790 *
1791 *   1. diff_words->last_minus == 0 &&
1792 *      diff_words->current_plus == diff_words->plus.text.ptr
1793 *
1794 *      that is: the plus text must start as a new line, and if there is no minus
1795 *      word printed, a graph prefix must be printed.
1796 *
1797 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1798 *      *(diff_words->current_plus - 1) == '\n'
1799 *
1800 *      that is: a graph prefix must be printed following a '\n'
1801 */
1802static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1803{
1804        if ((diff_words->last_minus == 0 &&
1805                diff_words->current_plus == diff_words->plus.text.ptr) ||
1806                (diff_words->current_plus > diff_words->plus.text.ptr &&
1807                *(diff_words->current_plus - 1) == '\n')) {
1808                return 1;
1809        } else {
1810                return 0;
1811        }
1812}
1813
1814static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1815{
1816        struct diff_words_data *diff_words = priv;
1817        struct diff_words_style *style = diff_words->style;
1818        int minus_first, minus_len, plus_first, plus_len;
1819        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1820        struct diff_options *opt = diff_words->opt;
1821        const char *line_prefix;
1822
1823        if (line[0] != '@' || parse_hunk_header(line, len,
1824                        &minus_first, &minus_len, &plus_first, &plus_len))
1825                return;
1826
1827        assert(opt);
1828        line_prefix = diff_line_prefix(opt);
1829
1830        /* POSIX requires that first be decremented by one if len == 0... */
1831        if (minus_len) {
1832                minus_begin = diff_words->minus.orig[minus_first].begin;
1833                minus_end =
1834                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1835        } else
1836                minus_begin = minus_end =
1837                        diff_words->minus.orig[minus_first].end;
1838
1839        if (plus_len) {
1840                plus_begin = diff_words->plus.orig[plus_first].begin;
1841                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1842        } else
1843                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1844
1845        if (color_words_output_graph_prefix(diff_words)) {
1846                fputs(line_prefix, diff_words->opt->file);
1847        }
1848        if (diff_words->current_plus != plus_begin) {
1849                fn_out_diff_words_write_helper(diff_words->opt,
1850                                &style->ctx, style->newline,
1851                                plus_begin - diff_words->current_plus,
1852                                diff_words->current_plus);
1853        }
1854        if (minus_begin != minus_end) {
1855                fn_out_diff_words_write_helper(diff_words->opt,
1856                                &style->old_word, style->newline,
1857                                minus_end - minus_begin, minus_begin);
1858        }
1859        if (plus_begin != plus_end) {
1860                fn_out_diff_words_write_helper(diff_words->opt,
1861                                &style->new_word, style->newline,
1862                                plus_end - plus_begin, plus_begin);
1863        }
1864
1865        diff_words->current_plus = plus_end;
1866        diff_words->last_minus = minus_first;
1867}
1868
1869/* This function starts looking at *begin, and returns 0 iff a word was found. */
1870static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1871                int *begin, int *end)
1872{
1873        if (word_regex && *begin < buffer->size) {
1874                regmatch_t match[1];
1875                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1876                                 buffer->size - *begin, 1, match, 0)) {
1877                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1878                                        '\n', match[0].rm_eo - match[0].rm_so);
1879                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1880                        *begin += match[0].rm_so;
1881                        return *begin >= *end;
1882                }
1883                return -1;
1884        }
1885
1886        /* find the next word */
1887        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1888                (*begin)++;
1889        if (*begin >= buffer->size)
1890                return -1;
1891
1892        /* find the end of the word */
1893        *end = *begin + 1;
1894        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1895                (*end)++;
1896
1897        return 0;
1898}
1899
1900/*
1901 * This function splits the words in buffer->text, stores the list with
1902 * newline separator into out, and saves the offsets of the original words
1903 * in buffer->orig.
1904 */
1905static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1906                regex_t *word_regex)
1907{
1908        int i, j;
1909        long alloc = 0;
1910
1911        out->size = 0;
1912        out->ptr = NULL;
1913
1914        /* fake an empty "0th" word */
1915        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1916        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1917        buffer->orig_nr = 1;
1918
1919        for (i = 0; i < buffer->text.size; i++) {
1920                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1921                        return;
1922
1923                /* store original boundaries */
1924                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1925                                buffer->orig_alloc);
1926                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1927                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1928                buffer->orig_nr++;
1929
1930                /* store one word */
1931                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1932                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1933                out->ptr[out->size + j - i] = '\n';
1934                out->size += j - i + 1;
1935
1936                i = j - 1;
1937        }
1938}
1939
1940/* this executes the word diff on the accumulated buffers */
1941static void diff_words_show(struct diff_words_data *diff_words)
1942{
1943        xpparam_t xpp;
1944        xdemitconf_t xecfg;
1945        mmfile_t minus, plus;
1946        struct diff_words_style *style = diff_words->style;
1947
1948        struct diff_options *opt = diff_words->opt;
1949        const char *line_prefix;
1950
1951        assert(opt);
1952        line_prefix = diff_line_prefix(opt);
1953
1954        /* special case: only removal */
1955        if (!diff_words->plus.text.size) {
1956                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1957                                 line_prefix, strlen(line_prefix), 0);
1958                fn_out_diff_words_write_helper(diff_words->opt,
1959                        &style->old_word, style->newline,
1960                        diff_words->minus.text.size,
1961                        diff_words->minus.text.ptr);
1962                diff_words->minus.text.size = 0;
1963                return;
1964        }
1965
1966        diff_words->current_plus = diff_words->plus.text.ptr;
1967        diff_words->last_minus = 0;
1968
1969        memset(&xpp, 0, sizeof(xpp));
1970        memset(&xecfg, 0, sizeof(xecfg));
1971        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1972        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1973        xpp.flags = 0;
1974        /* as only the hunk header will be parsed, we need a 0-context */
1975        xecfg.ctxlen = 0;
1976        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1977                          &xpp, &xecfg))
1978                die("unable to generate word diff");
1979        free(minus.ptr);
1980        free(plus.ptr);
1981        if (diff_words->current_plus != diff_words->plus.text.ptr +
1982                        diff_words->plus.text.size) {
1983                if (color_words_output_graph_prefix(diff_words))
1984                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1985                                         line_prefix, strlen(line_prefix), 0);
1986                fn_out_diff_words_write_helper(diff_words->opt,
1987                        &style->ctx, style->newline,
1988                        diff_words->plus.text.ptr + diff_words->plus.text.size
1989                        - diff_words->current_plus, diff_words->current_plus);
1990        }
1991        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1992}
1993
1994/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1995static void diff_words_flush(struct emit_callback *ecbdata)
1996{
1997        struct diff_options *wo = ecbdata->diff_words->opt;
1998
1999        if (ecbdata->diff_words->minus.text.size ||
2000            ecbdata->diff_words->plus.text.size)
2001                diff_words_show(ecbdata->diff_words);
2002
2003        if (wo->emitted_symbols) {
2004                struct diff_options *o = ecbdata->opt;
2005                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2006                int i;
2007
2008                /*
2009                 * NEEDSWORK:
2010                 * Instead of appending each, concat all words to a line?
2011                 */
2012                for (i = 0; i < wol->nr; i++)
2013                        append_emitted_diff_symbol(o, &wol->buf[i]);
2014
2015                for (i = 0; i < wol->nr; i++)
2016                        free((void *)wol->buf[i].line);
2017
2018                wol->nr = 0;
2019        }
2020}
2021
2022static void diff_filespec_load_driver(struct diff_filespec *one)
2023{
2024        /* Use already-loaded driver */
2025        if (one->driver)
2026                return;
2027
2028        if (S_ISREG(one->mode))
2029                one->driver = userdiff_find_by_path(one->path);
2030
2031        /* Fallback to default settings */
2032        if (!one->driver)
2033                one->driver = userdiff_find_by_name("default");
2034}
2035
2036static const char *userdiff_word_regex(struct diff_filespec *one)
2037{
2038        diff_filespec_load_driver(one);
2039        return one->driver->word_regex;
2040}
2041
2042static void init_diff_words_data(struct emit_callback *ecbdata,
2043                                 struct diff_options *orig_opts,
2044                                 struct diff_filespec *one,
2045                                 struct diff_filespec *two)
2046{
2047        int i;
2048        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2049        memcpy(o, orig_opts, sizeof(struct diff_options));
2050
2051        ecbdata->diff_words =
2052                xcalloc(1, sizeof(struct diff_words_data));
2053        ecbdata->diff_words->type = o->word_diff;
2054        ecbdata->diff_words->opt = o;
2055
2056        if (orig_opts->emitted_symbols)
2057                o->emitted_symbols =
2058                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2059
2060        if (!o->word_regex)
2061                o->word_regex = userdiff_word_regex(one);
2062        if (!o->word_regex)
2063                o->word_regex = userdiff_word_regex(two);
2064        if (!o->word_regex)
2065                o->word_regex = diff_word_regex_cfg;
2066        if (o->word_regex) {
2067                ecbdata->diff_words->word_regex = (regex_t *)
2068                        xmalloc(sizeof(regex_t));
2069                if (regcomp(ecbdata->diff_words->word_regex,
2070                            o->word_regex,
2071                            REG_EXTENDED | REG_NEWLINE))
2072                        die ("Invalid regular expression: %s",
2073                             o->word_regex);
2074        }
2075        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2076                if (o->word_diff == diff_words_styles[i].type) {
2077                        ecbdata->diff_words->style =
2078                                &diff_words_styles[i];
2079                        break;
2080                }
2081        }
2082        if (want_color(o->use_color)) {
2083                struct diff_words_style *st = ecbdata->diff_words->style;
2084                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2085                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2086                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2087        }
2088}
2089
2090static void free_diff_words_data(struct emit_callback *ecbdata)
2091{
2092        if (ecbdata->diff_words) {
2093                diff_words_flush(ecbdata);
2094                free (ecbdata->diff_words->opt->emitted_symbols);
2095                free (ecbdata->diff_words->opt);
2096                free (ecbdata->diff_words->minus.text.ptr);
2097                free (ecbdata->diff_words->minus.orig);
2098                free (ecbdata->diff_words->plus.text.ptr);
2099                free (ecbdata->diff_words->plus.orig);
2100                if (ecbdata->diff_words->word_regex) {
2101                        regfree(ecbdata->diff_words->word_regex);
2102                        free(ecbdata->diff_words->word_regex);
2103                }
2104                FREE_AND_NULL(ecbdata->diff_words);
2105        }
2106}
2107
2108const char *diff_get_color(int diff_use_color, enum color_diff ix)
2109{
2110        if (want_color(diff_use_color))
2111                return diff_colors[ix];
2112        return "";
2113}
2114
2115const char *diff_line_prefix(struct diff_options *opt)
2116{
2117        struct strbuf *msgbuf;
2118        if (!opt->output_prefix)
2119                return "";
2120
2121        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2122        return msgbuf->buf;
2123}
2124
2125static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
2126{
2127        const char *cp;
2128        unsigned long allot;
2129        size_t l = len;
2130
2131        cp = line;
2132        allot = l;
2133        while (0 < l) {
2134                (void) utf8_width(&cp, &l);
2135                if (!cp)
2136                        break; /* truncated in the middle? */
2137        }
2138        return allot - l;
2139}
2140
2141static void find_lno(const char *line, struct emit_callback *ecbdata)
2142{
2143        const char *p;
2144        ecbdata->lno_in_preimage = 0;
2145        ecbdata->lno_in_postimage = 0;
2146        p = strchr(line, '-');
2147        if (!p)
2148                return; /* cannot happen */
2149        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2150        p = strchr(p, '+');
2151        if (!p)
2152                return; /* cannot happen */
2153        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2154}
2155
2156static void fn_out_consume(void *priv, char *line, unsigned long len)
2157{
2158        struct emit_callback *ecbdata = priv;
2159        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2160        struct diff_options *o = ecbdata->opt;
2161
2162        o->found_changes = 1;
2163
2164        if (ecbdata->header) {
2165                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2166                                 ecbdata->header->buf, ecbdata->header->len, 0);
2167                strbuf_reset(ecbdata->header);
2168                ecbdata->header = NULL;
2169        }
2170
2171        if (ecbdata->label_path[0]) {
2172                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2173                                 ecbdata->label_path[0],
2174                                 strlen(ecbdata->label_path[0]), 0);
2175                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2176                                 ecbdata->label_path[1],
2177                                 strlen(ecbdata->label_path[1]), 0);
2178                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2179        }
2180
2181        if (diff_suppress_blank_empty
2182            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2183                line[0] = '\n';
2184                len = 1;
2185        }
2186
2187        if (line[0] == '@') {
2188                if (ecbdata->diff_words)
2189                        diff_words_flush(ecbdata);
2190                len = sane_truncate_line(ecbdata, line, len);
2191                find_lno(line, ecbdata);
2192                emit_hunk_header(ecbdata, line, len);
2193                return;
2194        }
2195
2196        if (ecbdata->diff_words) {
2197                enum diff_symbol s =
2198                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2199                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2200                if (line[0] == '-') {
2201                        diff_words_append(line, len,
2202                                          &ecbdata->diff_words->minus);
2203                        return;
2204                } else if (line[0] == '+') {
2205                        diff_words_append(line, len,
2206                                          &ecbdata->diff_words->plus);
2207                        return;
2208                } else if (starts_with(line, "\\ ")) {
2209                        /*
2210                         * Eat the "no newline at eof" marker as if we
2211                         * saw a "+" or "-" line with nothing on it,
2212                         * and return without diff_words_flush() to
2213                         * defer processing. If this is the end of
2214                         * preimage, more "+" lines may come after it.
2215                         */
2216                        return;
2217                }
2218                diff_words_flush(ecbdata);
2219                emit_diff_symbol(o, s, line, len, 0);
2220                return;
2221        }
2222
2223        switch (line[0]) {
2224        case '+':
2225                ecbdata->lno_in_postimage++;
2226                emit_add_line(reset, ecbdata, line + 1, len - 1);
2227                break;
2228        case '-':
2229                ecbdata->lno_in_preimage++;
2230                emit_del_line(reset, ecbdata, line + 1, len - 1);
2231                break;
2232        case ' ':
2233                ecbdata->lno_in_postimage++;
2234                ecbdata->lno_in_preimage++;
2235                emit_context_line(reset, ecbdata, line + 1, len - 1);
2236                break;
2237        default:
2238                /* incomplete line at the end */
2239                ecbdata->lno_in_preimage++;
2240                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2241                                 line, len, 0);
2242                break;
2243        }
2244}
2245
2246static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2247{
2248        const char *old_name = a;
2249        const char *new_name = b;
2250        int pfx_length, sfx_length;
2251        int pfx_adjust_for_slash;
2252        int len_a = strlen(a);
2253        int len_b = strlen(b);
2254        int a_midlen, b_midlen;
2255        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2256        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2257
2258        if (qlen_a || qlen_b) {
2259                quote_c_style(a, name, NULL, 0);
2260                strbuf_addstr(name, " => ");
2261                quote_c_style(b, name, NULL, 0);
2262                return;
2263        }
2264
2265        /* Find common prefix */
2266        pfx_length = 0;
2267        while (*old_name && *new_name && *old_name == *new_name) {
2268                if (*old_name == '/')
2269                        pfx_length = old_name - a + 1;
2270                old_name++;
2271                new_name++;
2272        }
2273
2274        /* Find common suffix */
2275        old_name = a + len_a;
2276        new_name = b + len_b;
2277        sfx_length = 0;
2278        /*
2279         * If there is a common prefix, it must end in a slash.  In
2280         * that case we let this loop run 1 into the prefix to see the
2281         * same slash.
2282         *
2283         * If there is no common prefix, we cannot do this as it would
2284         * underrun the input strings.
2285         */
2286        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2287        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2288               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2289               *old_name == *new_name) {
2290                if (*old_name == '/')
2291                        sfx_length = len_a - (old_name - a);
2292                old_name--;
2293                new_name--;
2294        }
2295
2296        /*
2297         * pfx{mid-a => mid-b}sfx
2298         * {pfx-a => pfx-b}sfx
2299         * pfx{sfx-a => sfx-b}
2300         * name-a => name-b
2301         */
2302        a_midlen = len_a - pfx_length - sfx_length;
2303        b_midlen = len_b - pfx_length - sfx_length;
2304        if (a_midlen < 0)
2305                a_midlen = 0;
2306        if (b_midlen < 0)
2307                b_midlen = 0;
2308
2309        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2310        if (pfx_length + sfx_length) {
2311                strbuf_add(name, a, pfx_length);
2312                strbuf_addch(name, '{');
2313        }
2314        strbuf_add(name, a + pfx_length, a_midlen);
2315        strbuf_addstr(name, " => ");
2316        strbuf_add(name, b + pfx_length, b_midlen);
2317        if (pfx_length + sfx_length) {
2318                strbuf_addch(name, '}');
2319                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2320        }
2321}
2322
2323struct diffstat_t {
2324        int nr;
2325        int alloc;
2326        struct diffstat_file {
2327                char *from_name;
2328                char *name;
2329                char *print_name;
2330                const char *comments;
2331                unsigned is_unmerged:1;
2332                unsigned is_binary:1;
2333                unsigned is_renamed:1;
2334                unsigned is_interesting:1;
2335                uintmax_t added, deleted;
2336        } **files;
2337};
2338
2339static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2340                                          const char *name_a,
2341                                          const char *name_b)
2342{
2343        struct diffstat_file *x;
2344        x = xcalloc(1, sizeof(*x));
2345        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2346        diffstat->files[diffstat->nr++] = x;
2347        if (name_b) {
2348                x->from_name = xstrdup(name_a);
2349                x->name = xstrdup(name_b);
2350                x->is_renamed = 1;
2351        }
2352        else {
2353                x->from_name = NULL;
2354                x->name = xstrdup(name_a);
2355        }
2356        return x;
2357}
2358
2359static void diffstat_consume(void *priv, char *line, unsigned long len)
2360{
2361        struct diffstat_t *diffstat = priv;
2362        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2363
2364        if (line[0] == '+')
2365                x->added++;
2366        else if (line[0] == '-')
2367                x->deleted++;
2368}
2369
2370const char mime_boundary_leader[] = "------------";
2371
2372static int scale_linear(int it, int width, int max_change)
2373{
2374        if (!it)
2375                return 0;
2376        /*
2377         * make sure that at least one '-' or '+' is printed if
2378         * there is any change to this path. The easiest way is to
2379         * scale linearly as if the alloted width is one column shorter
2380         * than it is, and then add 1 to the result.
2381         */
2382        return 1 + (it * (width - 1) / max_change);
2383}
2384
2385static void show_graph(struct strbuf *out, char ch, int cnt,
2386                       const char *set, const char *reset)
2387{
2388        if (cnt <= 0)
2389                return;
2390        strbuf_addstr(out, set);
2391        strbuf_addchars(out, ch, cnt);
2392        strbuf_addstr(out, reset);
2393}
2394
2395static void fill_print_name(struct diffstat_file *file)
2396{
2397        struct strbuf pname = STRBUF_INIT;
2398
2399        if (file->print_name)
2400                return;
2401
2402        if (file->is_renamed)
2403                pprint_rename(&pname, file->from_name, file->name);
2404        else
2405                quote_c_style(file->name, &pname, NULL, 0);
2406
2407        if (file->comments)
2408                strbuf_addf(&pname, " (%s)", file->comments);
2409
2410        file->print_name = strbuf_detach(&pname, NULL);
2411}
2412
2413static void print_stat_summary_inserts_deletes(struct diff_options *options,
2414                int files, int insertions, int deletions)
2415{
2416        struct strbuf sb = STRBUF_INIT;
2417
2418        if (!files) {
2419                assert(insertions == 0 && deletions == 0);
2420                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2421                                 NULL, 0, 0);
2422                return;
2423        }
2424
2425        strbuf_addf(&sb,
2426                    (files == 1) ? " %d file changed" : " %d files changed",
2427                    files);
2428
2429        /*
2430         * For binary diff, the caller may want to print "x files
2431         * changed" with insertions == 0 && deletions == 0.
2432         *
2433         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2434         * is probably less confusing (i.e skip over "2 files changed
2435         * but nothing about added/removed lines? Is this a bug in Git?").
2436         */
2437        if (insertions || deletions == 0) {
2438                strbuf_addf(&sb,
2439                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2440                            insertions);
2441        }
2442
2443        if (deletions || insertions == 0) {
2444                strbuf_addf(&sb,
2445                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2446                            deletions);
2447        }
2448        strbuf_addch(&sb, '\n');
2449        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2450                         sb.buf, sb.len, 0);
2451        strbuf_release(&sb);
2452}
2453
2454void print_stat_summary(FILE *fp, int files,
2455                        int insertions, int deletions)
2456{
2457        struct diff_options o;
2458        memset(&o, 0, sizeof(o));
2459        o.file = fp;
2460
2461        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2462}
2463
2464static void show_stats(struct diffstat_t *data, struct diff_options *options)
2465{
2466        int i, len, add, del, adds = 0, dels = 0;
2467        uintmax_t max_change = 0, max_len = 0;
2468        int total_files = data->nr, count;
2469        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2470        const char *reset, *add_c, *del_c;
2471        int extra_shown = 0;
2472        const char *line_prefix = diff_line_prefix(options);
2473        struct strbuf out = STRBUF_INIT;
2474
2475        if (data->nr == 0)
2476                return;
2477
2478        count = options->stat_count ? options->stat_count : data->nr;
2479
2480        reset = diff_get_color_opt(options, DIFF_RESET);
2481        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2482        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2483
2484        /*
2485         * Find the longest filename and max number of changes
2486         */
2487        for (i = 0; (i < count) && (i < data->nr); i++) {
2488                struct diffstat_file *file = data->files[i];
2489                uintmax_t change = file->added + file->deleted;
2490
2491                if (!file->is_interesting && (change == 0)) {
2492                        count++; /* not shown == room for one more */
2493                        continue;
2494                }
2495                fill_print_name(file);
2496                len = strlen(file->print_name);
2497                if (max_len < len)
2498                        max_len = len;
2499
2500                if (file->is_unmerged) {
2501                        /* "Unmerged" is 8 characters */
2502                        bin_width = bin_width < 8 ? 8 : bin_width;
2503                        continue;
2504                }
2505                if (file->is_binary) {
2506                        /* "Bin XXX -> YYY bytes" */
2507                        int w = 14 + decimal_width(file->added)
2508                                + decimal_width(file->deleted);
2509                        bin_width = bin_width < w ? w : bin_width;
2510                        /* Display change counts aligned with "Bin" */
2511                        number_width = 3;
2512                        continue;
2513                }
2514
2515                if (max_change < change)
2516                        max_change = change;
2517        }
2518        count = i; /* where we can stop scanning in data->files[] */
2519
2520        /*
2521         * We have width = stat_width or term_columns() columns total.
2522         * We want a maximum of min(max_len, stat_name_width) for the name part.
2523         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2524         * We also need 1 for " " and 4 + decimal_width(max_change)
2525         * for " | NNNN " and one the empty column at the end, altogether
2526         * 6 + decimal_width(max_change).
2527         *
2528         * If there's not enough space, we will use the smaller of
2529         * stat_name_width (if set) and 5/8*width for the filename,
2530         * and the rest for constant elements + graph part, but no more
2531         * than stat_graph_width for the graph part.
2532         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2533         * for the standard terminal size).
2534         *
2535         * In other words: stat_width limits the maximum width, and
2536         * stat_name_width fixes the maximum width of the filename,
2537         * and is also used to divide available columns if there
2538         * aren't enough.
2539         *
2540         * Binary files are displayed with "Bin XXX -> YYY bytes"
2541         * instead of the change count and graph. This part is treated
2542         * similarly to the graph part, except that it is not
2543         * "scaled". If total width is too small to accommodate the
2544         * guaranteed minimum width of the filename part and the
2545         * separators and this message, this message will "overflow"
2546         * making the line longer than the maximum width.
2547         */
2548
2549        if (options->stat_width == -1)
2550                width = term_columns() - strlen(line_prefix);
2551        else
2552                width = options->stat_width ? options->stat_width : 80;
2553        number_width = decimal_width(max_change) > number_width ?
2554                decimal_width(max_change) : number_width;
2555
2556        if (options->stat_graph_width == -1)
2557                options->stat_graph_width = diff_stat_graph_width;
2558
2559        /*
2560         * Guarantee 3/8*16==6 for the graph part
2561         * and 5/8*16==10 for the filename part
2562         */
2563        if (width < 16 + 6 + number_width)
2564                width = 16 + 6 + number_width;
2565
2566        /*
2567         * First assign sizes that are wanted, ignoring available width.
2568         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2569         * starting from "XXX" should fit in graph_width.
2570         */
2571        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2572        if (options->stat_graph_width &&
2573            options->stat_graph_width < graph_width)
2574                graph_width = options->stat_graph_width;
2575
2576        name_width = (options->stat_name_width > 0 &&
2577                      options->stat_name_width < max_len) ?
2578                options->stat_name_width : max_len;
2579
2580        /*
2581         * Adjust adjustable widths not to exceed maximum width
2582         */
2583        if (name_width + number_width + 6 + graph_width > width) {
2584                if (graph_width > width * 3/8 - number_width - 6) {
2585                        graph_width = width * 3/8 - number_width - 6;
2586                        if (graph_width < 6)
2587                                graph_width = 6;
2588                }
2589
2590                if (options->stat_graph_width &&
2591                    graph_width > options->stat_graph_width)
2592                        graph_width = options->stat_graph_width;
2593                if (name_width > width - number_width - 6 - graph_width)
2594                        name_width = width - number_width - 6 - graph_width;
2595                else
2596                        graph_width = width - number_width - 6 - name_width;
2597        }
2598
2599        /*
2600         * From here name_width is the width of the name area,
2601         * and graph_width is the width of the graph area.
2602         * max_change is used to scale graph properly.
2603         */
2604        for (i = 0; i < count; i++) {
2605                const char *prefix = "";
2606                struct diffstat_file *file = data->files[i];
2607                char *name = file->print_name;
2608                uintmax_t added = file->added;
2609                uintmax_t deleted = file->deleted;
2610                int name_len;
2611
2612                if (!file->is_interesting && (added + deleted == 0))
2613                        continue;
2614
2615                /*
2616                 * "scale" the filename
2617                 */
2618                len = name_width;
2619                name_len = strlen(name);
2620                if (name_width < name_len) {
2621                        char *slash;
2622                        prefix = "...";
2623                        len -= 3;
2624                        name += name_len - len;
2625                        slash = strchr(name, '/');
2626                        if (slash)
2627                                name = slash;
2628                }
2629
2630                if (file->is_binary) {
2631                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2632                        strbuf_addf(&out, " %*s", number_width, "Bin");
2633                        if (!added && !deleted) {
2634                                strbuf_addch(&out, '\n');
2635                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2636                                                 out.buf, out.len, 0);
2637                                strbuf_reset(&out);
2638                                continue;
2639                        }
2640                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2641                                del_c, deleted, reset);
2642                        strbuf_addstr(&out, " -> ");
2643                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2644                                add_c, added, reset);
2645                        strbuf_addstr(&out, " bytes\n");
2646                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2647                                         out.buf, out.len, 0);
2648                        strbuf_reset(&out);
2649                        continue;
2650                }
2651                else if (file->is_unmerged) {
2652                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2653                        strbuf_addstr(&out, " Unmerged\n");
2654                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2655                                         out.buf, out.len, 0);
2656                        strbuf_reset(&out);
2657                        continue;
2658                }
2659
2660                /*
2661                 * scale the add/delete
2662                 */
2663                add = added;
2664                del = deleted;
2665
2666                if (graph_width <= max_change) {
2667                        int total = scale_linear(add + del, graph_width, max_change);
2668                        if (total < 2 && add && del)
2669                                /* width >= 2 due to the sanity check */
2670                                total = 2;
2671                        if (add < del) {
2672                                add = scale_linear(add, graph_width, max_change);
2673                                del = total - add;
2674                        } else {
2675                                del = scale_linear(del, graph_width, max_change);
2676                                add = total - del;
2677                        }
2678                }
2679                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2680                strbuf_addf(&out, " %*"PRIuMAX"%s",
2681                        number_width, added + deleted,
2682                        added + deleted ? " " : "");
2683                show_graph(&out, '+', add, add_c, reset);
2684                show_graph(&out, '-', del, del_c, reset);
2685                strbuf_addch(&out, '\n');
2686                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2687                                 out.buf, out.len, 0);
2688                strbuf_reset(&out);
2689        }
2690
2691        for (i = 0; i < data->nr; i++) {
2692                struct diffstat_file *file = data->files[i];
2693                uintmax_t added = file->added;
2694                uintmax_t deleted = file->deleted;
2695
2696                if (file->is_unmerged ||
2697                    (!file->is_interesting && (added + deleted == 0))) {
2698                        total_files--;
2699                        continue;
2700                }
2701
2702                if (!file->is_binary) {
2703                        adds += added;
2704                        dels += deleted;
2705                }
2706                if (i < count)
2707                        continue;
2708                if (!extra_shown)
2709                        emit_diff_symbol(options,
2710                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2711                                         NULL, 0, 0);
2712                extra_shown = 1;
2713        }
2714
2715        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2716        strbuf_release(&out);
2717}
2718
2719static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2720{
2721        int i, adds = 0, dels = 0, total_files = data->nr;
2722
2723        if (data->nr == 0)
2724                return;
2725
2726        for (i = 0; i < data->nr; i++) {
2727                int added = data->files[i]->added;
2728                int deleted = data->files[i]->deleted;
2729
2730                if (data->files[i]->is_unmerged ||
2731                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2732                        total_files--;
2733                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2734                        adds += added;
2735                        dels += deleted;
2736                }
2737        }
2738        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2739}
2740
2741static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2742{
2743        int i;
2744
2745        if (data->nr == 0)
2746                return;
2747
2748        for (i = 0; i < data->nr; i++) {
2749                struct diffstat_file *file = data->files[i];
2750
2751                fprintf(options->file, "%s", diff_line_prefix(options));
2752
2753                if (file->is_binary)
2754                        fprintf(options->file, "-\t-\t");
2755                else
2756                        fprintf(options->file,
2757                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2758                                file->added, file->deleted);
2759                if (options->line_termination) {
2760                        fill_print_name(file);
2761                        if (!file->is_renamed)
2762                                write_name_quoted(file->name, options->file,
2763                                                  options->line_termination);
2764                        else {
2765                                fputs(file->print_name, options->file);
2766                                putc(options->line_termination, options->file);
2767                        }
2768                } else {
2769                        if (file->is_renamed) {
2770                                putc('\0', options->file);
2771                                write_name_quoted(file->from_name, options->file, '\0');
2772                        }
2773                        write_name_quoted(file->name, options->file, '\0');
2774                }
2775        }
2776}
2777
2778struct dirstat_file {
2779        const char *name;
2780        unsigned long changed;
2781};
2782
2783struct dirstat_dir {
2784        struct dirstat_file *files;
2785        int alloc, nr, permille, cumulative;
2786};
2787
2788static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2789                unsigned long changed, const char *base, int baselen)
2790{
2791        unsigned long sum_changes = 0;
2792        unsigned int sources = 0;
2793        const char *line_prefix = diff_line_prefix(opt);
2794
2795        while (dir->nr) {
2796                struct dirstat_file *f = dir->files;
2797                int namelen = strlen(f->name);
2798                unsigned long changes;
2799                char *slash;
2800
2801                if (namelen < baselen)
2802                        break;
2803                if (memcmp(f->name, base, baselen))
2804                        break;
2805                slash = strchr(f->name + baselen, '/');
2806                if (slash) {
2807                        int newbaselen = slash + 1 - f->name;
2808                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2809                        sources++;
2810                } else {
2811                        changes = f->changed;
2812                        dir->files++;
2813                        dir->nr--;
2814                        sources += 2;
2815                }
2816                sum_changes += changes;
2817        }
2818
2819        /*
2820         * We don't report dirstat's for
2821         *  - the top level
2822         *  - or cases where everything came from a single directory
2823         *    under this directory (sources == 1).
2824         */
2825        if (baselen && sources != 1) {
2826                if (sum_changes) {
2827                        int permille = sum_changes * 1000 / changed;
2828                        if (permille >= dir->permille) {
2829                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2830                                        permille / 10, permille % 10, baselen, base);
2831                                if (!dir->cumulative)
2832                                        return 0;
2833                        }
2834                }
2835        }
2836        return sum_changes;
2837}
2838
2839static int dirstat_compare(const void *_a, const void *_b)
2840{
2841        const struct dirstat_file *a = _a;
2842        const struct dirstat_file *b = _b;
2843        return strcmp(a->name, b->name);
2844}
2845
2846static void show_dirstat(struct diff_options *options)
2847{
2848        int i;
2849        unsigned long changed;
2850        struct dirstat_dir dir;
2851        struct diff_queue_struct *q = &diff_queued_diff;
2852
2853        dir.files = NULL;
2854        dir.alloc = 0;
2855        dir.nr = 0;
2856        dir.permille = options->dirstat_permille;
2857        dir.cumulative = options->flags.dirstat_cumulative;
2858
2859        changed = 0;
2860        for (i = 0; i < q->nr; i++) {
2861                struct diff_filepair *p = q->queue[i];
2862                const char *name;
2863                unsigned long copied, added, damage;
2864                int content_changed;
2865
2866                name = p->two->path ? p->two->path : p->one->path;
2867
2868                if (p->one->oid_valid && p->two->oid_valid)
2869                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
2870                else
2871                        content_changed = 1;
2872
2873                if (!content_changed) {
2874                        /*
2875                         * The SHA1 has not changed, so pre-/post-content is
2876                         * identical. We can therefore skip looking at the
2877                         * file contents altogether.
2878                         */
2879                        damage = 0;
2880                        goto found_damage;
2881                }
2882
2883                if (options->flags.dirstat_by_file) {
2884                        /*
2885                         * In --dirstat-by-file mode, we don't really need to
2886                         * look at the actual file contents at all.
2887                         * The fact that the SHA1 changed is enough for us to
2888                         * add this file to the list of results
2889                         * (with each file contributing equal damage).
2890                         */
2891                        damage = 1;
2892                        goto found_damage;
2893                }
2894
2895                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2896                        diff_populate_filespec(p->one, 0);
2897                        diff_populate_filespec(p->two, 0);
2898                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2899                                               &copied, &added);
2900                        diff_free_filespec_data(p->one);
2901                        diff_free_filespec_data(p->two);
2902                } else if (DIFF_FILE_VALID(p->one)) {
2903                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2904                        copied = added = 0;
2905                        diff_free_filespec_data(p->one);
2906                } else if (DIFF_FILE_VALID(p->two)) {
2907                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2908                        copied = 0;
2909                        added = p->two->size;
2910                        diff_free_filespec_data(p->two);
2911                } else
2912                        continue;
2913
2914                /*
2915                 * Original minus copied is the removed material,
2916                 * added is the new material.  They are both damages
2917                 * made to the preimage.
2918                 * If the resulting damage is zero, we know that
2919                 * diffcore_count_changes() considers the two entries to
2920                 * be identical, but since content_changed is true, we
2921                 * know that there must have been _some_ kind of change,
2922                 * so we force all entries to have damage > 0.
2923                 */
2924                damage = (p->one->size - copied) + added;
2925                if (!damage)
2926                        damage = 1;
2927
2928found_damage:
2929                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2930                dir.files[dir.nr].name = name;
2931                dir.files[dir.nr].changed = damage;
2932                changed += damage;
2933                dir.nr++;
2934        }
2935
2936        /* This can happen even with many files, if everything was renames */
2937        if (!changed)
2938                return;
2939
2940        /* Show all directories with more than x% of the changes */
2941        QSORT(dir.files, dir.nr, dirstat_compare);
2942        gather_dirstat(options, &dir, changed, "", 0);
2943}
2944
2945static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2946{
2947        int i;
2948        unsigned long changed;
2949        struct dirstat_dir dir;
2950
2951        if (data->nr == 0)
2952                return;
2953
2954        dir.files = NULL;
2955        dir.alloc = 0;
2956        dir.nr = 0;
2957        dir.permille = options->dirstat_permille;
2958        dir.cumulative = options->flags.dirstat_cumulative;
2959
2960        changed = 0;
2961        for (i = 0; i < data->nr; i++) {
2962                struct diffstat_file *file = data->files[i];
2963                unsigned long damage = file->added + file->deleted;
2964                if (file->is_binary)
2965                        /*
2966                         * binary files counts bytes, not lines. Must find some
2967                         * way to normalize binary bytes vs. textual lines.
2968                         * The following heuristic assumes that there are 64
2969                         * bytes per "line".
2970                         * This is stupid and ugly, but very cheap...
2971                         */
2972                        damage = DIV_ROUND_UP(damage, 64);
2973                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2974                dir.files[dir.nr].name = file->name;
2975                dir.files[dir.nr].changed = damage;
2976                changed += damage;
2977                dir.nr++;
2978        }
2979
2980        /* This can happen even with many files, if everything was renames */
2981        if (!changed)
2982                return;
2983
2984        /* Show all directories with more than x% of the changes */
2985        QSORT(dir.files, dir.nr, dirstat_compare);
2986        gather_dirstat(options, &dir, changed, "", 0);
2987}
2988
2989static void free_diffstat_info(struct diffstat_t *diffstat)
2990{
2991        int i;
2992        for (i = 0; i < diffstat->nr; i++) {
2993                struct diffstat_file *f = diffstat->files[i];
2994                free(f->print_name);
2995                free(f->name);
2996                free(f->from_name);
2997                free(f);
2998        }
2999        free(diffstat->files);
3000}
3001
3002struct checkdiff_t {
3003        const char *filename;
3004        int lineno;
3005        int conflict_marker_size;
3006        struct diff_options *o;
3007        unsigned ws_rule;
3008        unsigned status;
3009};
3010
3011static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3012{
3013        char firstchar;
3014        int cnt;
3015
3016        if (len < marker_size + 1)
3017                return 0;
3018        firstchar = line[0];
3019        switch (firstchar) {
3020        case '=': case '>': case '<': case '|':
3021                break;
3022        default:
3023                return 0;
3024        }
3025        for (cnt = 1; cnt < marker_size; cnt++)
3026                if (line[cnt] != firstchar)
3027                        return 0;
3028        /* line[1] thru line[marker_size-1] are same as firstchar */
3029        if (len < marker_size + 1 || !isspace(line[marker_size]))
3030                return 0;
3031        return 1;
3032}
3033
3034static void checkdiff_consume(void *priv, char *line, unsigned long len)
3035{
3036        struct checkdiff_t *data = priv;
3037        int marker_size = data->conflict_marker_size;
3038        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3039        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3040        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3041        char *err;
3042        const char *line_prefix;
3043
3044        assert(data->o);
3045        line_prefix = diff_line_prefix(data->o);
3046
3047        if (line[0] == '+') {
3048                unsigned bad;
3049                data->lineno++;
3050                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3051                        data->status |= 1;
3052                        fprintf(data->o->file,
3053                                "%s%s:%d: leftover conflict marker\n",
3054                                line_prefix, data->filename, data->lineno);
3055                }
3056                bad = ws_check(line + 1, len - 1, data->ws_rule);
3057                if (!bad)
3058                        return;
3059                data->status |= bad;
3060                err = whitespace_error_string(bad);
3061                fprintf(data->o->file, "%s%s:%d: %s.\n",
3062                        line_prefix, data->filename, data->lineno, err);
3063                free(err);
3064                emit_line(data->o, set, reset, line, 1);
3065                ws_check_emit(line + 1, len - 1, data->ws_rule,
3066                              data->o->file, set, reset, ws);
3067        } else if (line[0] == ' ') {
3068                data->lineno++;
3069        } else if (line[0] == '@') {
3070                char *plus = strchr(line, '+');
3071                if (plus)
3072                        data->lineno = strtol(plus, NULL, 10) - 1;
3073                else
3074                        die("invalid diff");
3075        }
3076}
3077
3078static unsigned char *deflate_it(char *data,
3079                                 unsigned long size,
3080                                 unsigned long *result_size)
3081{
3082        int bound;
3083        unsigned char *deflated;
3084        git_zstream stream;
3085
3086        git_deflate_init(&stream, zlib_compression_level);
3087        bound = git_deflate_bound(&stream, size);
3088        deflated = xmalloc(bound);
3089        stream.next_out = deflated;
3090        stream.avail_out = bound;
3091
3092        stream.next_in = (unsigned char *)data;
3093        stream.avail_in = size;
3094        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3095                ; /* nothing */
3096        git_deflate_end(&stream);
3097        *result_size = stream.total_out;
3098        return deflated;
3099}
3100
3101static void emit_binary_diff_body(struct diff_options *o,
3102                                  mmfile_t *one, mmfile_t *two)
3103{
3104        void *cp;
3105        void *delta;
3106        void *deflated;
3107        void *data;
3108        unsigned long orig_size;
3109        unsigned long delta_size;
3110        unsigned long deflate_size;
3111        unsigned long data_size;
3112
3113        /* We could do deflated delta, or we could do just deflated two,
3114         * whichever is smaller.
3115         */
3116        delta = NULL;
3117        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3118        if (one->size && two->size) {
3119                delta = diff_delta(one->ptr, one->size,
3120                                   two->ptr, two->size,
3121                                   &delta_size, deflate_size);
3122                if (delta) {
3123                        void *to_free = delta;
3124                        orig_size = delta_size;
3125                        delta = deflate_it(delta, delta_size, &delta_size);
3126                        free(to_free);
3127                }
3128        }
3129
3130        if (delta && delta_size < deflate_size) {
3131                char *s = xstrfmt("%lu", orig_size);
3132                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3133                                 s, strlen(s), 0);
3134                free(s);
3135                free(deflated);
3136                data = delta;
3137                data_size = delta_size;
3138        } else {
3139                char *s = xstrfmt("%lu", two->size);
3140                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3141                                 s, strlen(s), 0);
3142                free(s);
3143                free(delta);
3144                data = deflated;
3145                data_size = deflate_size;
3146        }
3147
3148        /* emit data encoded in base85 */
3149        cp = data;
3150        while (data_size) {
3151                int len;
3152                int bytes = (52 < data_size) ? 52 : data_size;
3153                char line[71];
3154                data_size -= bytes;
3155                if (bytes <= 26)
3156                        line[0] = bytes + 'A' - 1;
3157                else
3158                        line[0] = bytes - 26 + 'a' - 1;
3159                encode_85(line + 1, cp, bytes);
3160                cp = (char *) cp + bytes;
3161
3162                len = strlen(line);
3163                line[len++] = '\n';
3164                line[len] = '\0';
3165
3166                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3167                                 line, len, 0);
3168        }
3169        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3170        free(data);
3171}
3172
3173static void emit_binary_diff(struct diff_options *o,
3174                             mmfile_t *one, mmfile_t *two)
3175{
3176        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3177        emit_binary_diff_body(o, one, two);
3178        emit_binary_diff_body(o, two, one);
3179}
3180
3181int diff_filespec_is_binary(struct diff_filespec *one)
3182{
3183        if (one->is_binary == -1) {
3184                diff_filespec_load_driver(one);
3185                if (one->driver->binary != -1)
3186                        one->is_binary = one->driver->binary;
3187                else {
3188                        if (!one->data && DIFF_FILE_VALID(one))
3189                                diff_populate_filespec(one, CHECK_BINARY);
3190                        if (one->is_binary == -1 && one->data)
3191                                one->is_binary = buffer_is_binary(one->data,
3192                                                one->size);
3193                        if (one->is_binary == -1)
3194                                one->is_binary = 0;
3195                }
3196        }
3197        return one->is_binary;
3198}
3199
3200static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
3201{
3202        diff_filespec_load_driver(one);
3203        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3204}
3205
3206void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3207{
3208        if (!options->a_prefix)
3209                options->a_prefix = a;
3210        if (!options->b_prefix)
3211                options->b_prefix = b;
3212}
3213
3214struct userdiff_driver *get_textconv(struct diff_filespec *one)
3215{
3216        if (!DIFF_FILE_VALID(one))
3217                return NULL;
3218
3219        diff_filespec_load_driver(one);
3220        return userdiff_get_textconv(one->driver);
3221}
3222
3223static void builtin_diff(const char *name_a,
3224                         const char *name_b,
3225                         struct diff_filespec *one,
3226                         struct diff_filespec *two,
3227                         const char *xfrm_msg,
3228                         int must_show_header,
3229                         struct diff_options *o,
3230                         int complete_rewrite)
3231{
3232        mmfile_t mf1, mf2;
3233        const char *lbl[2];
3234        char *a_one, *b_two;
3235        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3236        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3237        const char *a_prefix, *b_prefix;
3238        struct userdiff_driver *textconv_one = NULL;
3239        struct userdiff_driver *textconv_two = NULL;
3240        struct strbuf header = STRBUF_INIT;
3241        const char *line_prefix = diff_line_prefix(o);
3242
3243        diff_set_mnemonic_prefix(o, "a/", "b/");
3244        if (o->flags.reverse_diff) {
3245                a_prefix = o->b_prefix;
3246                b_prefix = o->a_prefix;
3247        } else {
3248                a_prefix = o->a_prefix;
3249                b_prefix = o->b_prefix;
3250        }
3251
3252        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3253            (!one->mode || S_ISGITLINK(one->mode)) &&
3254            (!two->mode || S_ISGITLINK(two->mode))) {
3255                show_submodule_summary(o, one->path ? one->path : two->path,
3256                                &one->oid, &two->oid,
3257                                two->dirty_submodule);
3258                return;
3259        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3260                   (!one->mode || S_ISGITLINK(one->mode)) &&
3261                   (!two->mode || S_ISGITLINK(two->mode))) {
3262                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3263                                &one->oid, &two->oid,
3264                                two->dirty_submodule);
3265                return;
3266        }
3267
3268        if (o->flags.allow_textconv) {
3269                textconv_one = get_textconv(one);
3270                textconv_two = get_textconv(two);
3271        }
3272
3273        /* Never use a non-valid filename anywhere if at all possible */
3274        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3275        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3276
3277        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3278        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3279        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3280        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3281        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3282        if (lbl[0][0] == '/') {
3283                /* /dev/null */
3284                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3285                if (xfrm_msg)
3286                        strbuf_addstr(&header, xfrm_msg);
3287                must_show_header = 1;
3288        }
3289        else if (lbl[1][0] == '/') {
3290                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3291                if (xfrm_msg)
3292                        strbuf_addstr(&header, xfrm_msg);
3293                must_show_header = 1;
3294        }
3295        else {
3296                if (one->mode != two->mode) {
3297                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3298                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3299                        must_show_header = 1;
3300                }
3301                if (xfrm_msg)
3302                        strbuf_addstr(&header, xfrm_msg);
3303
3304                /*
3305                 * we do not run diff between different kind
3306                 * of objects.
3307                 */
3308                if ((one->mode ^ two->mode) & S_IFMT)
3309                        goto free_ab_and_return;
3310                if (complete_rewrite &&
3311                    (textconv_one || !diff_filespec_is_binary(one)) &&
3312                    (textconv_two || !diff_filespec_is_binary(two))) {
3313                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3314                                         header.buf, header.len, 0);
3315                        strbuf_reset(&header);
3316                        emit_rewrite_diff(name_a, name_b, one, two,
3317                                                textconv_one, textconv_two, o);
3318                        o->found_changes = 1;
3319                        goto free_ab_and_return;
3320                }
3321        }
3322
3323        if (o->irreversible_delete && lbl[1][0] == '/') {
3324                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3325                                 header.len, 0);
3326                strbuf_reset(&header);
3327                goto free_ab_and_return;
3328        } else if (!o->flags.text &&
3329            ( (!textconv_one && diff_filespec_is_binary(one)) ||
3330              (!textconv_two && diff_filespec_is_binary(two)) )) {
3331                struct strbuf sb = STRBUF_INIT;
3332                if (!one->data && !two->data &&
3333                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3334                    !o->flags.binary) {
3335                        if (!oidcmp(&one->oid, &two->oid)) {
3336                                if (must_show_header)
3337                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3338                                                         header.buf, header.len,
3339                                                         0);
3340                                goto free_ab_and_return;
3341                        }
3342                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3343                                         header.buf, header.len, 0);
3344                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3345                                    diff_line_prefix(o), lbl[0], lbl[1]);
3346                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3347                                         sb.buf, sb.len, 0);
3348                        strbuf_release(&sb);
3349                        goto free_ab_and_return;
3350                }
3351                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3352                        die("unable to read files to diff");
3353                /* Quite common confusing case */
3354                if (mf1.size == mf2.size &&
3355                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3356                        if (must_show_header)
3357                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3358                                                 header.buf, header.len, 0);
3359                        goto free_ab_and_return;
3360                }
3361                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3362                strbuf_reset(&header);
3363                if (o->flags.binary)
3364                        emit_binary_diff(o, &mf1, &mf2);
3365                else {
3366                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3367                                    diff_line_prefix(o), lbl[0], lbl[1]);
3368                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3369                                         sb.buf, sb.len, 0);
3370                        strbuf_release(&sb);
3371                }
3372                o->found_changes = 1;
3373        } else {
3374                /* Crazy xdl interfaces.. */
3375                const char *diffopts = getenv("GIT_DIFF_OPTS");
3376                const char *v;
3377                xpparam_t xpp;
3378                xdemitconf_t xecfg;
3379                struct emit_callback ecbdata;
3380                const struct userdiff_funcname *pe;
3381
3382                if (must_show_header) {
3383                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3384                                         header.buf, header.len, 0);
3385                        strbuf_reset(&header);
3386                }
3387
3388                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
3389                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
3390
3391                pe = diff_funcname_pattern(one);
3392                if (!pe)
3393                        pe = diff_funcname_pattern(two);
3394
3395                memset(&xpp, 0, sizeof(xpp));
3396                memset(&xecfg, 0, sizeof(xecfg));
3397                memset(&ecbdata, 0, sizeof(ecbdata));
3398                ecbdata.label_path = lbl;
3399                ecbdata.color_diff = want_color(o->use_color);
3400                ecbdata.ws_rule = whitespace_rule(name_b);
3401                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3402                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3403                ecbdata.opt = o;
3404                ecbdata.header = header.len ? &header : NULL;
3405                xpp.flags = o->xdl_opts;
3406                xpp.anchors = o->anchors;
3407                xpp.anchors_nr = o->anchors_nr;
3408                xecfg.ctxlen = o->context;
3409                xecfg.interhunkctxlen = o->interhunkcontext;
3410                xecfg.flags = XDL_EMIT_FUNCNAMES;
3411                if (o->flags.funccontext)
3412                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3413                if (pe)
3414                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3415                if (!diffopts)
3416                        ;
3417                else if (skip_prefix(diffopts, "--unified=", &v))
3418                        xecfg.ctxlen = strtoul(v, NULL, 10);
3419                else if (skip_prefix(diffopts, "-u", &v))
3420                        xecfg.ctxlen = strtoul(v, NULL, 10);
3421                if (o->word_diff)
3422                        init_diff_words_data(&ecbdata, o, one, two);
3423                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
3424                                  &xpp, &xecfg))
3425                        die("unable to generate diff for %s", one->path);
3426                if (o->word_diff)
3427                        free_diff_words_data(&ecbdata);
3428                if (textconv_one)
3429                        free(mf1.ptr);
3430                if (textconv_two)
3431                        free(mf2.ptr);
3432                xdiff_clear_find_func(&xecfg);
3433        }
3434
3435 free_ab_and_return:
3436        strbuf_release(&header);
3437        diff_free_filespec_data(one);
3438        diff_free_filespec_data(two);
3439        free(a_one);
3440        free(b_two);
3441        return;
3442}
3443
3444static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3445{
3446        if (!is_renamed) {
3447                if (p->status == DIFF_STATUS_ADDED) {
3448                        if (S_ISLNK(p->two->mode))
3449                                return "new +l";
3450                        else if ((p->two->mode & 0777) == 0755)
3451                                return "new +x";
3452                        else
3453                                return "new";
3454                } else if (p->status == DIFF_STATUS_DELETED)
3455                        return "gone";
3456        }
3457        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3458                return "mode -l";
3459        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3460                return "mode +l";
3461        else if ((p->one->mode & 0777) == 0644 &&
3462                 (p->two->mode & 0777) == 0755)
3463                return "mode +x";
3464        else if ((p->one->mode & 0777) == 0755 &&
3465                 (p->two->mode & 0777) == 0644)
3466                return "mode -x";
3467        return NULL;
3468}
3469
3470static void builtin_diffstat(const char *name_a, const char *name_b,
3471                             struct diff_filespec *one,
3472                             struct diff_filespec *two,
3473                             struct diffstat_t *diffstat,
3474                             struct diff_options *o,
3475                             struct diff_filepair *p)
3476{
3477        mmfile_t mf1, mf2;
3478        struct diffstat_file *data;
3479        int same_contents;
3480        int complete_rewrite = 0;
3481
3482        if (!DIFF_PAIR_UNMERGED(p)) {
3483                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3484                        complete_rewrite = 1;
3485        }
3486
3487        data = diffstat_add(diffstat, name_a, name_b);
3488        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3489        if (o->flags.stat_with_summary)
3490                data->comments = get_compact_summary(p, data->is_renamed);
3491
3492        if (!one || !two) {
3493                data->is_unmerged = 1;
3494                return;
3495        }
3496
3497        same_contents = !oidcmp(&one->oid, &two->oid);
3498
3499        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
3500                data->is_binary = 1;
3501                if (same_contents) {
3502                        data->added = 0;
3503                        data->deleted = 0;
3504                } else {
3505                        data->added = diff_filespec_size(two);
3506                        data->deleted = diff_filespec_size(one);
3507                }
3508        }
3509
3510        else if (complete_rewrite) {
3511                diff_populate_filespec(one, 0);
3512                diff_populate_filespec(two, 0);
3513                data->deleted = count_lines(one->data, one->size);
3514                data->added = count_lines(two->data, two->size);
3515        }
3516
3517        else if (!same_contents) {
3518                /* Crazy xdl interfaces.. */
3519                xpparam_t xpp;
3520                xdemitconf_t xecfg;
3521
3522                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3523                        die("unable to read files to diff");
3524
3525                memset(&xpp, 0, sizeof(xpp));
3526                memset(&xecfg, 0, sizeof(xecfg));
3527                xpp.flags = o->xdl_opts;
3528                xpp.anchors = o->anchors;
3529                xpp.anchors_nr = o->anchors_nr;
3530                xecfg.ctxlen = o->context;
3531                xecfg.interhunkctxlen = o->interhunkcontext;
3532                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
3533                                  &xpp, &xecfg))
3534                        die("unable to generate diffstat for %s", one->path);
3535        }
3536
3537        diff_free_filespec_data(one);
3538        diff_free_filespec_data(two);
3539}
3540
3541static void builtin_checkdiff(const char *name_a, const char *name_b,
3542                              const char *attr_path,
3543                              struct diff_filespec *one,
3544                              struct diff_filespec *two,
3545                              struct diff_options *o)
3546{
3547        mmfile_t mf1, mf2;
3548        struct checkdiff_t data;
3549
3550        if (!two)
3551                return;
3552
3553        memset(&data, 0, sizeof(data));
3554        data.filename = name_b ? name_b : name_a;
3555        data.lineno = 0;
3556        data.o = o;
3557        data.ws_rule = whitespace_rule(attr_path);
3558        data.conflict_marker_size = ll_merge_marker_size(attr_path);
3559
3560        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3561                die("unable to read files to diff");
3562
3563        /*
3564         * All the other codepaths check both sides, but not checking
3565         * the "old" side here is deliberate.  We are checking the newly
3566         * introduced changes, and as long as the "new" side is text, we
3567         * can and should check what it introduces.
3568         */
3569        if (diff_filespec_is_binary(two))
3570                goto free_and_return;
3571        else {
3572                /* Crazy xdl interfaces.. */
3573                xpparam_t xpp;
3574                xdemitconf_t xecfg;
3575
3576                memset(&xpp, 0, sizeof(xpp));
3577                memset(&xecfg, 0, sizeof(xecfg));
3578                xecfg.ctxlen = 1; /* at least one context line */
3579                xpp.flags = 0;
3580                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
3581                                  &xpp, &xecfg))
3582                        die("unable to generate checkdiff for %s", one->path);
3583
3584                if (data.ws_rule & WS_BLANK_AT_EOF) {
3585                        struct emit_callback ecbdata;
3586                        int blank_at_eof;
3587
3588                        ecbdata.ws_rule = data.ws_rule;
3589                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3590                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3591
3592                        if (blank_at_eof) {
3593                                static char *err;
3594                                if (!err)
3595                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3596                                fprintf(o->file, "%s:%d: %s.\n",
3597                                        data.filename, blank_at_eof, err);
3598                                data.status = 1; /* report errors */
3599                        }
3600                }
3601        }
3602 free_and_return:
3603        diff_free_filespec_data(one);
3604        diff_free_filespec_data(two);
3605        if (data.status)
3606                o->flags.check_failed = 1;
3607}
3608
3609struct diff_filespec *alloc_filespec(const char *path)
3610{
3611        struct diff_filespec *spec;
3612
3613        FLEXPTR_ALLOC_STR(spec, path, path);
3614        spec->count = 1;
3615        spec->is_binary = -1;
3616        return spec;
3617}
3618
3619void free_filespec(struct diff_filespec *spec)
3620{
3621        if (!--spec->count) {
3622                diff_free_filespec_data(spec);
3623                free(spec);
3624        }
3625}
3626
3627void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3628                   int oid_valid, unsigned short mode)
3629{
3630        if (mode) {
3631                spec->mode = canon_mode(mode);
3632                oidcpy(&spec->oid, oid);
3633                spec->oid_valid = oid_valid;
3634        }
3635}
3636
3637/*
3638 * Given a name and sha1 pair, if the index tells us the file in
3639 * the work tree has that object contents, return true, so that
3640 * prepare_temp_file() does not have to inflate and extract.
3641 */
3642static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
3643{
3644        const struct cache_entry *ce;
3645        struct stat st;
3646        int pos, len;
3647
3648        /*
3649         * We do not read the cache ourselves here, because the
3650         * benchmark with my previous version that always reads cache
3651         * shows that it makes things worse for diff-tree comparing
3652         * two linux-2.6 kernel trees in an already checked out work
3653         * tree.  This is because most diff-tree comparisons deal with
3654         * only a small number of files, while reading the cache is
3655         * expensive for a large project, and its cost outweighs the
3656         * savings we get by not inflating the object to a temporary
3657         * file.  Practically, this code only helps when we are used
3658         * by diff-cache --cached, which does read the cache before
3659         * calling us.
3660         */
3661        if (!active_cache)
3662                return 0;
3663
3664        /* We want to avoid the working directory if our caller
3665         * doesn't need the data in a normal file, this system
3666         * is rather slow with its stat/open/mmap/close syscalls,
3667         * and the object is contained in a pack file.  The pack
3668         * is probably already open and will be faster to obtain
3669         * the data through than the working directory.  Loose
3670         * objects however would tend to be slower as they need
3671         * to be individually opened and inflated.
3672         */
3673        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3674                return 0;
3675
3676        /*
3677         * Similarly, if we'd have to convert the file contents anyway, that
3678         * makes the optimization not worthwhile.
3679         */
3680        if (!want_file && would_convert_to_git(&the_index, name))
3681                return 0;
3682
3683        len = strlen(name);
3684        pos = cache_name_pos(name, len);
3685        if (pos < 0)
3686                return 0;
3687        ce = active_cache[pos];
3688
3689        /*
3690         * This is not the sha1 we are looking for, or
3691         * unreusable because it is not a regular file.
3692         */
3693        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3694                return 0;
3695
3696        /*
3697         * If ce is marked as "assume unchanged", there is no
3698         * guarantee that work tree matches what we are looking for.
3699         */
3700        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3701                return 0;
3702
3703        /*
3704         * If ce matches the file in the work tree, we can reuse it.
3705         */
3706        if (ce_uptodate(ce) ||
3707            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
3708                return 1;
3709
3710        return 0;
3711}
3712
3713static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3714{
3715        struct strbuf buf = STRBUF_INIT;
3716        char *dirty = "";
3717
3718        /* Are we looking at the work tree? */
3719        if (s->dirty_submodule)
3720                dirty = "-dirty";
3721
3722        strbuf_addf(&buf, "Subproject commit %s%s\n",
3723                    oid_to_hex(&s->oid), dirty);
3724        s->size = buf.len;
3725        if (size_only) {
3726                s->data = NULL;
3727                strbuf_release(&buf);
3728        } else {
3729                s->data = strbuf_detach(&buf, NULL);
3730                s->should_free = 1;
3731        }
3732        return 0;
3733}
3734
3735/*
3736 * While doing rename detection and pickaxe operation, we may need to
3737 * grab the data for the blob (or file) for our own in-core comparison.
3738 * diff_filespec has data and size fields for this purpose.
3739 */
3740int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
3741{
3742        int size_only = flags & CHECK_SIZE_ONLY;
3743        int err = 0;
3744        int conv_flags = global_conv_flags_eol;
3745        /*
3746         * demote FAIL to WARN to allow inspecting the situation
3747         * instead of refusing.
3748         */
3749        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3750                conv_flags = CONV_EOL_RNDTRP_WARN;
3751
3752        if (!DIFF_FILE_VALID(s))
3753                die("internal error: asking to populate invalid file.");
3754        if (S_ISDIR(s->mode))
3755                return -1;
3756
3757        if (s->data)
3758                return 0;
3759
3760        if (size_only && 0 < s->size)
3761                return 0;
3762
3763        if (S_ISGITLINK(s->mode))
3764                return diff_populate_gitlink(s, size_only);
3765
3766        if (!s->oid_valid ||
3767            reuse_worktree_file(s->path, &s->oid, 0)) {
3768                struct strbuf buf = STRBUF_INIT;
3769                struct stat st;
3770                int fd;
3771
3772                if (lstat(s->path, &st) < 0) {
3773                err_empty:
3774                        err = -1;
3775                empty:
3776                        s->data = (char *)"";
3777                        s->size = 0;
3778                        return err;
3779                }
3780                s->size = xsize_t(st.st_size);
3781                if (!s->size)
3782                        goto empty;
3783                if (S_ISLNK(st.st_mode)) {
3784                        struct strbuf sb = STRBUF_INIT;
3785
3786                        if (strbuf_readlink(&sb, s->path, s->size))
3787                                goto err_empty;
3788                        s->size = sb.len;
3789                        s->data = strbuf_detach(&sb, NULL);
3790                        s->should_free = 1;
3791                        return 0;
3792                }
3793
3794                /*
3795                 * Even if the caller would be happy with getting
3796                 * only the size, we cannot return early at this
3797                 * point if the path requires us to run the content
3798                 * conversion.
3799                 */
3800                if (size_only && !would_convert_to_git(&the_index, s->path))
3801                        return 0;
3802
3803                /*
3804                 * Note: this check uses xsize_t(st.st_size) that may
3805                 * not be the true size of the blob after it goes
3806                 * through convert_to_git().  This may not strictly be
3807                 * correct, but the whole point of big_file_threshold
3808                 * and is_binary check being that we want to avoid
3809                 * opening the file and inspecting the contents, this
3810                 * is probably fine.
3811                 */
3812                if ((flags & CHECK_BINARY) &&
3813                    s->size > big_file_threshold && s->is_binary == -1) {
3814                        s->is_binary = 1;
3815                        return 0;
3816                }
3817                fd = open(s->path, O_RDONLY);
3818                if (fd < 0)
3819                        goto err_empty;
3820                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3821                close(fd);
3822                s->should_munmap = 1;
3823
3824                /*
3825                 * Convert from working tree format to canonical git format
3826                 */
3827                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, conv_flags)) {
3828                        size_t size = 0;
3829                        munmap(s->data, s->size);
3830                        s->should_munmap = 0;
3831                        s->data = strbuf_detach(&buf, &size);
3832                        s->size = size;
3833                        s->should_free = 1;
3834                }
3835        }
3836        else {
3837                enum object_type type;
3838                if (size_only || (flags & CHECK_BINARY)) {
3839                        type = oid_object_info(the_repository, &s->oid,
3840                                               &s->size);
3841                        if (type < 0)
3842                                die("unable to read %s",
3843                                    oid_to_hex(&s->oid));
3844                        if (size_only)
3845                                return 0;
3846                        if (s->size > big_file_threshold && s->is_binary == -1) {
3847                                s->is_binary = 1;
3848                                return 0;
3849                        }
3850                }
3851                s->data = read_object_file(&s->oid, &type, &s->size);
3852                if (!s->data)
3853                        die("unable to read %s", oid_to_hex(&s->oid));
3854                s->should_free = 1;
3855        }
3856        return 0;
3857}
3858
3859void diff_free_filespec_blob(struct diff_filespec *s)
3860{
3861        if (s->should_free)
3862                free(s->data);
3863        else if (s->should_munmap)
3864                munmap(s->data, s->size);
3865
3866        if (s->should_free || s->should_munmap) {
3867                s->should_free = s->should_munmap = 0;
3868                s->data = NULL;
3869        }
3870}
3871
3872void diff_free_filespec_data(struct diff_filespec *s)
3873{
3874        diff_free_filespec_blob(s);
3875        FREE_AND_NULL(s->cnt_data);
3876}
3877
3878static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
3879                           void *blob,
3880                           unsigned long size,
3881                           const struct object_id *oid,
3882                           int mode)
3883{
3884        struct strbuf buf = STRBUF_INIT;
3885        struct strbuf tempfile = STRBUF_INIT;
3886        char *path_dup = xstrdup(path);
3887        const char *base = basename(path_dup);
3888
3889        /* Generate "XXXXXX_basename.ext" */
3890        strbuf_addstr(&tempfile, "XXXXXX_");
3891        strbuf_addstr(&tempfile, base);
3892
3893        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
3894        if (!temp->tempfile)
3895                die_errno("unable to create temp-file");
3896        if (convert_to_working_tree(path,
3897                        (const char *)blob, (size_t)size, &buf)) {
3898                blob = buf.buf;
3899                size = buf.len;
3900        }
3901        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
3902            close_tempfile_gently(temp->tempfile))
3903                die_errno("unable to write temp-file");
3904        temp->name = get_tempfile_path(temp->tempfile);
3905        oid_to_hex_r(temp->hex, oid);
3906        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3907        strbuf_release(&buf);
3908        strbuf_release(&tempfile);
3909        free(path_dup);
3910}
3911
3912static struct diff_tempfile *prepare_temp_file(const char *name,
3913                struct diff_filespec *one)
3914{
3915        struct diff_tempfile *temp = claim_diff_tempfile();
3916
3917        if (!DIFF_FILE_VALID(one)) {
3918        not_a_valid_file:
3919                /* A '-' entry produces this for file-2, and
3920                 * a '+' entry produces this for file-1.
3921                 */
3922                temp->name = "/dev/null";
3923                xsnprintf(temp->hex, sizeof(temp->hex), ".");
3924                xsnprintf(temp->mode, sizeof(temp->mode), ".");
3925                return temp;
3926        }
3927
3928        if (!S_ISGITLINK(one->mode) &&
3929            (!one->oid_valid ||
3930             reuse_worktree_file(name, &one->oid, 1))) {
3931                struct stat st;
3932                if (lstat(name, &st) < 0) {
3933                        if (errno == ENOENT)
3934                                goto not_a_valid_file;
3935                        die_errno("stat(%s)", name);
3936                }
3937                if (S_ISLNK(st.st_mode)) {
3938                        struct strbuf sb = STRBUF_INIT;
3939                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
3940                                die_errno("readlink(%s)", name);
3941                        prep_temp_blob(name, temp, sb.buf, sb.len,
3942                                       (one->oid_valid ?
3943                                        &one->oid : &null_oid),
3944                                       (one->oid_valid ?
3945                                        one->mode : S_IFLNK));
3946                        strbuf_release(&sb);
3947                }
3948                else {
3949                        /* we can borrow from the file in the work tree */
3950                        temp->name = name;
3951                        if (!one->oid_valid)
3952                                oid_to_hex_r(temp->hex, &null_oid);
3953                        else
3954                                oid_to_hex_r(temp->hex, &one->oid);
3955                        /* Even though we may sometimes borrow the
3956                         * contents from the work tree, we always want
3957                         * one->mode.  mode is trustworthy even when
3958                         * !(one->oid_valid), as long as
3959                         * DIFF_FILE_VALID(one).
3960                         */
3961                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
3962                }
3963                return temp;
3964        }
3965        else {
3966                if (diff_populate_filespec(one, 0))
3967                        die("cannot read data blob for %s", one->path);
3968                prep_temp_blob(name, temp, one->data, one->size,
3969                               &one->oid, one->mode);
3970        }
3971        return temp;
3972}
3973
3974static void add_external_diff_name(struct argv_array *argv,
3975                                   const char *name,
3976                                   struct diff_filespec *df)
3977{
3978        struct diff_tempfile *temp = prepare_temp_file(name, df);
3979        argv_array_push(argv, temp->name);
3980        argv_array_push(argv, temp->hex);
3981        argv_array_push(argv, temp->mode);
3982}
3983
3984/* An external diff command takes:
3985 *
3986 * diff-cmd name infile1 infile1-sha1 infile1-mode \
3987 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
3988 *
3989 */
3990static void run_external_diff(const char *pgm,
3991                              const char *name,
3992                              const char *other,
3993                              struct diff_filespec *one,
3994                              struct diff_filespec *two,
3995                              const char *xfrm_msg,
3996                              int complete_rewrite,
3997                              struct diff_options *o)
3998{
3999        struct argv_array argv = ARGV_ARRAY_INIT;
4000        struct argv_array env = ARGV_ARRAY_INIT;
4001        struct diff_queue_struct *q = &diff_queued_diff;
4002
4003        argv_array_push(&argv, pgm);
4004        argv_array_push(&argv, name);
4005
4006        if (one && two) {
4007                add_external_diff_name(&argv, name, one);
4008                if (!other)
4009                        add_external_diff_name(&argv, name, two);
4010                else {
4011                        add_external_diff_name(&argv, other, two);
4012                        argv_array_push(&argv, other);
4013                        argv_array_push(&argv, xfrm_msg);
4014                }
4015        }
4016
4017        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4018        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4019
4020        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4021                die(_("external diff died, stopping at %s"), name);
4022
4023        remove_tempfile();
4024        argv_array_clear(&argv);
4025        argv_array_clear(&env);
4026}
4027
4028static int similarity_index(struct diff_filepair *p)
4029{
4030        return p->score * 100 / MAX_SCORE;
4031}
4032
4033static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4034{
4035        if (startup_info->have_repository)
4036                return find_unique_abbrev(oid, abbrev);
4037        else {
4038                char *hex = oid_to_hex(oid);
4039                if (abbrev < 0)
4040                        abbrev = FALLBACK_DEFAULT_ABBREV;
4041                if (abbrev > the_hash_algo->hexsz)
4042                        BUG("oid abbreviation out of range: %d", abbrev);
4043                if (abbrev)
4044                        hex[abbrev] = '\0';
4045                return hex;
4046        }
4047}
4048
4049static void fill_metainfo(struct strbuf *msg,
4050                          const char *name,
4051                          const char *other,
4052                          struct diff_filespec *one,
4053                          struct diff_filespec *two,
4054                          struct diff_options *o,
4055                          struct diff_filepair *p,
4056                          int *must_show_header,
4057                          int use_color)
4058{
4059        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4060        const char *reset = diff_get_color(use_color, DIFF_RESET);
4061        const char *line_prefix = diff_line_prefix(o);
4062
4063        *must_show_header = 1;
4064        strbuf_init(msg, PATH_MAX * 2 + 300);
4065        switch (p->status) {
4066        case DIFF_STATUS_COPIED:
4067                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4068                            line_prefix, set, similarity_index(p));
4069                strbuf_addf(msg, "%s\n%s%scopy from ",
4070                            reset,  line_prefix, set);
4071                quote_c_style(name, msg, NULL, 0);
4072                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4073                quote_c_style(other, msg, NULL, 0);
4074                strbuf_addf(msg, "%s\n", reset);
4075                break;
4076        case DIFF_STATUS_RENAMED:
4077                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4078                            line_prefix, set, similarity_index(p));
4079                strbuf_addf(msg, "%s\n%s%srename from ",
4080                            reset, line_prefix, set);
4081                quote_c_style(name, msg, NULL, 0);
4082                strbuf_addf(msg, "%s\n%s%srename to ",
4083                            reset, line_prefix, set);
4084                quote_c_style(other, msg, NULL, 0);
4085                strbuf_addf(msg, "%s\n", reset);
4086                break;
4087        case DIFF_STATUS_MODIFIED:
4088                if (p->score) {
4089                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4090                                    line_prefix,
4091                                    set, similarity_index(p), reset);
4092                        break;
4093                }
4094                /* fallthru */
4095        default:
4096                *must_show_header = 0;
4097        }
4098        if (one && two && oidcmp(&one->oid, &two->oid)) {
4099                const unsigned hexsz = the_hash_algo->hexsz;
4100                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4101
4102                if (o->flags.binary) {
4103                        mmfile_t mf;
4104                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
4105                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
4106                                abbrev = hexsz;
4107                }
4108                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4109                            diff_abbrev_oid(&one->oid, abbrev),
4110                            diff_abbrev_oid(&two->oid, abbrev));
4111                if (one->mode == two->mode)
4112                        strbuf_addf(msg, " %06o", one->mode);
4113                strbuf_addf(msg, "%s\n", reset);
4114        }
4115}
4116
4117static void run_diff_cmd(const char *pgm,
4118                         const char *name,
4119                         const char *other,
4120                         const char *attr_path,
4121                         struct diff_filespec *one,
4122                         struct diff_filespec *two,
4123                         struct strbuf *msg,
4124                         struct diff_options *o,
4125                         struct diff_filepair *p)
4126{
4127        const char *xfrm_msg = NULL;
4128        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4129        int must_show_header = 0;
4130
4131
4132        if (o->flags.allow_external) {
4133                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
4134                if (drv && drv->external)
4135                        pgm = drv->external;
4136        }
4137
4138        if (msg) {
4139                /*
4140                 * don't use colors when the header is intended for an
4141                 * external diff driver
4142                 */
4143                fill_metainfo(msg, name, other, one, two, o, p,
4144                              &must_show_header,
4145                              want_color(o->use_color) && !pgm);
4146                xfrm_msg = msg->len ? msg->buf : NULL;
4147        }
4148
4149        if (pgm) {
4150                run_external_diff(pgm, name, other, one, two, xfrm_msg,
4151                                  complete_rewrite, o);
4152                return;
4153        }
4154        if (one && two)
4155                builtin_diff(name, other ? other : name,
4156                             one, two, xfrm_msg, must_show_header,
4157                             o, complete_rewrite);
4158        else
4159                fprintf(o->file, "* Unmerged path %s\n", name);
4160}
4161
4162static void diff_fill_oid_info(struct diff_filespec *one)
4163{
4164        if (DIFF_FILE_VALID(one)) {
4165                if (!one->oid_valid) {
4166                        struct stat st;
4167                        if (one->is_stdin) {
4168                                oidclr(&one->oid);
4169                                return;
4170                        }
4171                        if (lstat(one->path, &st) < 0)
4172                                die_errno("stat '%s'", one->path);
4173                        if (index_path(&one->oid, one->path, &st, 0))
4174                                die("cannot hash %s", one->path);
4175                }
4176        }
4177        else
4178                oidclr(&one->oid);
4179}
4180
4181static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4182{
4183        /* Strip the prefix but do not molest /dev/null and absolute paths */
4184        if (*namep && **namep != '/') {
4185                *namep += prefix_length;
4186                if (**namep == '/')
4187                        ++*namep;
4188        }
4189        if (*otherp && **otherp != '/') {
4190                *otherp += prefix_length;
4191                if (**otherp == '/')
4192                        ++*otherp;
4193        }
4194}
4195
4196static void run_diff(struct diff_filepair *p, struct diff_options *o)
4197{
4198        const char *pgm = external_diff();
4199        struct strbuf msg;
4200        struct diff_filespec *one = p->one;
4201        struct diff_filespec *two = p->two;
4202        const char *name;
4203        const char *other;
4204        const char *attr_path;
4205
4206        name  = one->path;
4207        other = (strcmp(name, two->path) ? two->path : NULL);
4208        attr_path = name;
4209        if (o->prefix_length)
4210                strip_prefix(o->prefix_length, &name, &other);
4211
4212        if (!o->flags.allow_external)
4213                pgm = NULL;
4214
4215        if (DIFF_PAIR_UNMERGED(p)) {
4216                run_diff_cmd(pgm, name, NULL, attr_path,
4217                             NULL, NULL, NULL, o, p);
4218                return;
4219        }
4220
4221        diff_fill_oid_info(one);
4222        diff_fill_oid_info(two);
4223
4224        if (!pgm &&
4225            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4226            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4227                /*
4228                 * a filepair that changes between file and symlink
4229                 * needs to be split into deletion and creation.
4230                 */
4231                struct diff_filespec *null = alloc_filespec(two->path);
4232                run_diff_cmd(NULL, name, other, attr_path,
4233                             one, null, &msg, o, p);
4234                free(null);
4235                strbuf_release(&msg);
4236
4237                null = alloc_filespec(one->path);
4238                run_diff_cmd(NULL, name, other, attr_path,
4239                             null, two, &msg, o, p);
4240                free(null);
4241        }
4242        else
4243                run_diff_cmd(pgm, name, other, attr_path,
4244                             one, two, &msg, o, p);
4245
4246        strbuf_release(&msg);
4247}
4248
4249static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4250                         struct diffstat_t *diffstat)
4251{
4252        const char *name;
4253        const char *other;
4254
4255        if (DIFF_PAIR_UNMERGED(p)) {
4256                /* unmerged */
4257                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
4258                return;
4259        }
4260
4261        name = p->one->path;
4262        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4263
4264        if (o->prefix_length)
4265                strip_prefix(o->prefix_length, &name, &other);
4266
4267        diff_fill_oid_info(p->one);
4268        diff_fill_oid_info(p->two);
4269
4270        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
4271}
4272
4273static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4274{
4275        const char *name;
4276        const char *other;
4277        const char *attr_path;
4278
4279        if (DIFF_PAIR_UNMERGED(p)) {
4280                /* unmerged */
4281                return;
4282        }
4283
4284        name = p->one->path;
4285        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4286        attr_path = other ? other : name;
4287
4288        if (o->prefix_length)
4289                strip_prefix(o->prefix_length, &name, &other);
4290
4291        diff_fill_oid_info(p->one);
4292        diff_fill_oid_info(p->two);
4293
4294        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4295}
4296
4297void diff_setup(struct diff_options *options)
4298{
4299        memcpy(options, &default_diff_options, sizeof(*options));
4300
4301        options->file = stdout;
4302
4303        options->abbrev = DEFAULT_ABBREV;
4304        options->line_termination = '\n';
4305        options->break_opt = -1;
4306        options->rename_limit = -1;
4307        options->dirstat_permille = diff_dirstat_permille_default;
4308        options->context = diff_context_default;
4309        options->interhunkcontext = diff_interhunk_context_default;
4310        options->ws_error_highlight = ws_error_highlight_default;
4311        options->flags.rename_empty = 1;
4312        options->objfind = NULL;
4313
4314        /* pathchange left =NULL by default */
4315        options->change = diff_change;
4316        options->add_remove = diff_addremove;
4317        options->use_color = diff_use_color_default;
4318        options->detect_rename = diff_detect_rename_default;
4319        options->xdl_opts |= diff_algorithm;
4320        if (diff_indent_heuristic)
4321                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4322
4323        options->orderfile = diff_order_file_cfg;
4324
4325        if (diff_no_prefix) {
4326                options->a_prefix = options->b_prefix = "";
4327        } else if (!diff_mnemonic_prefix) {
4328                options->a_prefix = "a/";
4329                options->b_prefix = "b/";
4330        }
4331
4332        options->color_moved = diff_color_moved_default;
4333        options->color_moved_ws_handling = diff_color_moved_ws_default;
4334}
4335
4336void diff_setup_done(struct diff_options *options)
4337{
4338        unsigned check_mask = DIFF_FORMAT_NAME |
4339                              DIFF_FORMAT_NAME_STATUS |
4340                              DIFF_FORMAT_CHECKDIFF |
4341                              DIFF_FORMAT_NO_OUTPUT;
4342        /*
4343         * This must be signed because we're comparing against a potentially
4344         * negative value.
4345         */
4346        const int hexsz = the_hash_algo->hexsz;
4347
4348        if (options->set_default)
4349                options->set_default(options);
4350
4351        if (HAS_MULTI_BITS(options->output_format & check_mask))
4352                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4353
4354        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4355                die(_("-G, -S and --find-object are mutually exclusive"));
4356
4357        /*
4358         * Most of the time we can say "there are changes"
4359         * only by checking if there are changed paths, but
4360         * --ignore-whitespace* options force us to look
4361         * inside contents.
4362         */
4363
4364        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4365                options->flags.diff_from_contents = 1;
4366        else
4367                options->flags.diff_from_contents = 0;
4368
4369        if (options->flags.find_copies_harder)
4370                options->detect_rename = DIFF_DETECT_COPY;
4371
4372        if (!options->flags.relative_name)
4373                options->prefix = NULL;
4374        if (options->prefix)
4375                options->prefix_length = strlen(options->prefix);
4376        else
4377                options->prefix_length = 0;
4378
4379        if (options->output_format & (DIFF_FORMAT_NAME |
4380                                      DIFF_FORMAT_NAME_STATUS |
4381                                      DIFF_FORMAT_CHECKDIFF |
4382                                      DIFF_FORMAT_NO_OUTPUT))
4383                options->output_format &= ~(DIFF_FORMAT_RAW |
4384                                            DIFF_FORMAT_NUMSTAT |
4385                                            DIFF_FORMAT_DIFFSTAT |
4386                                            DIFF_FORMAT_SHORTSTAT |
4387                                            DIFF_FORMAT_DIRSTAT |
4388                                            DIFF_FORMAT_SUMMARY |
4389                                            DIFF_FORMAT_PATCH);
4390
4391        /*
4392         * These cases always need recursive; we do not drop caller-supplied
4393         * recursive bits for other formats here.
4394         */
4395        if (options->output_format & (DIFF_FORMAT_PATCH |
4396                                      DIFF_FORMAT_NUMSTAT |
4397                                      DIFF_FORMAT_DIFFSTAT |
4398                                      DIFF_FORMAT_SHORTSTAT |
4399                                      DIFF_FORMAT_DIRSTAT |
4400                                      DIFF_FORMAT_SUMMARY |
4401                                      DIFF_FORMAT_CHECKDIFF))
4402                options->flags.recursive = 1;
4403        /*
4404         * Also pickaxe would not work very well if you do not say recursive
4405         */
4406        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4407                options->flags.recursive = 1;
4408        /*
4409         * When patches are generated, submodules diffed against the work tree
4410         * must be checked for dirtiness too so it can be shown in the output
4411         */
4412        if (options->output_format & DIFF_FORMAT_PATCH)
4413                options->flags.dirty_submodules = 1;
4414
4415        if (options->detect_rename && options->rename_limit < 0)
4416                options->rename_limit = diff_rename_limit_default;
4417        if (options->setup & DIFF_SETUP_USE_CACHE) {
4418                if (!active_cache)
4419                        /* read-cache does not die even when it fails
4420                         * so it is safe for us to do this here.  Also
4421                         * it does not smudge active_cache or active_nr
4422                         * when it fails, so we do not have to worry about
4423                         * cleaning it up ourselves either.
4424                         */
4425                        read_cache();
4426        }
4427        if (hexsz < options->abbrev)
4428                options->abbrev = hexsz; /* full */
4429
4430        /*
4431         * It does not make sense to show the first hit we happened
4432         * to have found.  It does not make sense not to return with
4433         * exit code in such a case either.
4434         */
4435        if (options->flags.quick) {
4436                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4437                options->flags.exit_with_status = 1;
4438        }
4439
4440        options->diff_path_counter = 0;
4441
4442        if (options->flags.follow_renames && options->pathspec.nr != 1)
4443                die(_("--follow requires exactly one pathspec"));
4444
4445        if (!options->use_color || external_diff())
4446                options->color_moved = 0;
4447}
4448
4449static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4450{
4451        char c, *eq;
4452        int len;
4453
4454        if (*arg != '-')
4455                return 0;
4456        c = *++arg;
4457        if (!c)
4458                return 0;
4459        if (c == arg_short) {
4460                c = *++arg;
4461                if (!c)
4462                        return 1;
4463                if (val && isdigit(c)) {
4464                        char *end;
4465                        int n = strtoul(arg, &end, 10);
4466                        if (*end)
4467                                return 0;
4468                        *val = n;
4469                        return 1;
4470                }
4471                return 0;
4472        }
4473        if (c != '-')
4474                return 0;
4475        arg++;
4476        eq = strchrnul(arg, '=');
4477        len = eq - arg;
4478        if (!len || strncmp(arg, arg_long, len))
4479                return 0;
4480        if (*eq) {
4481                int n;
4482                char *end;
4483                if (!isdigit(*++eq))
4484                        return 0;
4485                n = strtoul(eq, &end, 10);
4486                if (*end)
4487                        return 0;
4488                *val = n;
4489        }
4490        return 1;
4491}
4492
4493static int diff_scoreopt_parse(const char *opt);
4494
4495static inline int short_opt(char opt, const char **argv,
4496                            const char **optarg)
4497{
4498        const char *arg = argv[0];
4499        if (arg[0] != '-' || arg[1] != opt)
4500                return 0;
4501        if (arg[2] != '\0') {
4502                *optarg = arg + 2;
4503                return 1;
4504        }
4505        if (!argv[1])
4506                die("Option '%c' requires a value", opt);
4507        *optarg = argv[1];
4508        return 2;
4509}
4510
4511int parse_long_opt(const char *opt, const char **argv,
4512                   const char **optarg)
4513{
4514        const char *arg = argv[0];
4515        if (!skip_prefix(arg, "--", &arg))
4516                return 0;
4517        if (!skip_prefix(arg, opt, &arg))
4518                return 0;
4519        if (*arg == '=') { /* stuck form: --option=value */
4520                *optarg = arg + 1;
4521                return 1;
4522        }
4523        if (*arg != '\0')
4524                return 0;
4525        /* separate form: --option value */
4526        if (!argv[1])
4527                die("Option '--%s' requires a value", opt);
4528        *optarg = argv[1];
4529        return 2;
4530}
4531
4532static int stat_opt(struct diff_options *options, const char **av)
4533{
4534        const char *arg = av[0];
4535        char *end;
4536        int width = options->stat_width;
4537        int name_width = options->stat_name_width;
4538        int graph_width = options->stat_graph_width;
4539        int count = options->stat_count;
4540        int argcount = 1;
4541
4542        if (!skip_prefix(arg, "--stat", &arg))
4543                BUG("stat option does not begin with --stat: %s", arg);
4544        end = (char *)arg;
4545
4546        switch (*arg) {
4547        case '-':
4548                if (skip_prefix(arg, "-width", &arg)) {
4549                        if (*arg == '=')
4550                                width = strtoul(arg + 1, &end, 10);
4551                        else if (!*arg && !av[1])
4552                                die_want_option("--stat-width");
4553                        else if (!*arg) {
4554                                width = strtoul(av[1], &end, 10);
4555                                argcount = 2;
4556                        }
4557                } else if (skip_prefix(arg, "-name-width", &arg)) {
4558                        if (*arg == '=')
4559                                name_width = strtoul(arg + 1, &end, 10);
4560                        else if (!*arg && !av[1])
4561                                die_want_option("--stat-name-width");
4562                        else if (!*arg) {
4563                                name_width = strtoul(av[1], &end, 10);
4564                                argcount = 2;
4565                        }
4566                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4567                        if (*arg == '=')
4568                                graph_width = strtoul(arg + 1, &end, 10);
4569                        else if (!*arg && !av[1])
4570                                die_want_option("--stat-graph-width");
4571                        else if (!*arg) {
4572                                graph_width = strtoul(av[1], &end, 10);
4573                                argcount = 2;
4574                        }
4575                } else if (skip_prefix(arg, "-count", &arg)) {
4576                        if (*arg == '=')
4577                                count = strtoul(arg + 1, &end, 10);
4578                        else if (!*arg && !av[1])
4579                                die_want_option("--stat-count");
4580                        else if (!*arg) {
4581                                count = strtoul(av[1], &end, 10);
4582                                argcount = 2;
4583                        }
4584                }
4585                break;
4586        case '=':
4587                width = strtoul(arg+1, &end, 10);
4588                if (*end == ',')
4589                        name_width = strtoul(end+1, &end, 10);
4590                if (*end == ',')
4591                        count = strtoul(end+1, &end, 10);
4592        }
4593
4594        /* Important! This checks all the error cases! */
4595        if (*end)
4596                return 0;
4597        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4598        options->stat_name_width = name_width;
4599        options->stat_graph_width = graph_width;
4600        options->stat_width = width;
4601        options->stat_count = count;
4602        return argcount;
4603}
4604
4605static int parse_dirstat_opt(struct diff_options *options, const char *params)
4606{
4607        struct strbuf errmsg = STRBUF_INIT;
4608        if (parse_dirstat_params(options, params, &errmsg))
4609                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4610                    errmsg.buf);
4611        strbuf_release(&errmsg);
4612        /*
4613         * The caller knows a dirstat-related option is given from the command
4614         * line; allow it to say "return this_function();"
4615         */
4616        options->output_format |= DIFF_FORMAT_DIRSTAT;
4617        return 1;
4618}
4619
4620static int parse_submodule_opt(struct diff_options *options, const char *value)
4621{
4622        if (parse_submodule_params(options, value))
4623                die(_("Failed to parse --submodule option parameter: '%s'"),
4624                        value);
4625        return 1;
4626}
4627
4628static const char diff_status_letters[] = {
4629        DIFF_STATUS_ADDED,
4630        DIFF_STATUS_COPIED,
4631        DIFF_STATUS_DELETED,
4632        DIFF_STATUS_MODIFIED,
4633        DIFF_STATUS_RENAMED,
4634        DIFF_STATUS_TYPE_CHANGED,
4635        DIFF_STATUS_UNKNOWN,
4636        DIFF_STATUS_UNMERGED,
4637        DIFF_STATUS_FILTER_AON,
4638        DIFF_STATUS_FILTER_BROKEN,
4639        '\0',
4640};
4641
4642static unsigned int filter_bit['Z' + 1];
4643
4644static void prepare_filter_bits(void)
4645{
4646        int i;
4647
4648        if (!filter_bit[DIFF_STATUS_ADDED]) {
4649                for (i = 0; diff_status_letters[i]; i++)
4650                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4651        }
4652}
4653
4654static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4655{
4656        return opt->filter & filter_bit[(int) status];
4657}
4658
4659static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4660{
4661        int i, optch;
4662
4663        prepare_filter_bits();
4664
4665        /*
4666         * If there is a negation e.g. 'd' in the input, and we haven't
4667         * initialized the filter field with another --diff-filter, start
4668         * from full set of bits, except for AON.
4669         */
4670        if (!opt->filter) {
4671                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4672                        if (optch < 'a' || 'z' < optch)
4673                                continue;
4674                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4675                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4676                        break;
4677                }
4678        }
4679
4680        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4681                unsigned int bit;
4682                int negate;
4683
4684                if ('a' <= optch && optch <= 'z') {
4685                        negate = 1;
4686                        optch = toupper(optch);
4687                } else {
4688                        negate = 0;
4689                }
4690
4691                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4692                if (!bit)
4693                        return optarg[i];
4694                if (negate)
4695                        opt->filter &= ~bit;
4696                else
4697                        opt->filter |= bit;
4698        }
4699        return 0;
4700}
4701
4702static void enable_patch_output(int *fmt) {
4703        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4704        *fmt |= DIFF_FORMAT_PATCH;
4705}
4706
4707static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4708{
4709        int val = parse_ws_error_highlight(arg);
4710
4711        if (val < 0) {
4712                error("unknown value after ws-error-highlight=%.*s",
4713                      -1 - val, arg);
4714                return 0;
4715        }
4716        opt->ws_error_highlight = val;
4717        return 1;
4718}
4719
4720static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4721{
4722        struct object_id oid;
4723
4724        if (get_oid(arg, &oid))
4725                return error("unable to resolve '%s'", arg);
4726
4727        if (!opt->objfind)
4728                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4729
4730        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4731        opt->flags.recursive = 1;
4732        opt->flags.tree_in_recursive = 1;
4733        oidset_insert(opt->objfind, &oid);
4734        return 1;
4735}
4736
4737int diff_opt_parse(struct diff_options *options,
4738                   const char **av, int ac, const char *prefix)
4739{
4740        const char *arg = av[0];
4741        const char *optarg;
4742        int argcount;
4743
4744        if (!prefix)
4745                prefix = "";
4746
4747        /* Output format options */
4748        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4749            || opt_arg(arg, 'U', "unified", &options->context))
4750                enable_patch_output(&options->output_format);
4751        else if (!strcmp(arg, "--raw"))
4752                options->output_format |= DIFF_FORMAT_RAW;
4753        else if (!strcmp(arg, "--patch-with-raw")) {
4754                enable_patch_output(&options->output_format);
4755                options->output_format |= DIFF_FORMAT_RAW;
4756        } else if (!strcmp(arg, "--numstat"))
4757                options->output_format |= DIFF_FORMAT_NUMSTAT;
4758        else if (!strcmp(arg, "--shortstat"))
4759                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4760        else if (skip_prefix(arg, "-X", &arg) ||
4761                 skip_to_optional_arg(arg, "--dirstat", &arg))
4762                return parse_dirstat_opt(options, arg);
4763        else if (!strcmp(arg, "--cumulative"))
4764                return parse_dirstat_opt(options, "cumulative");
4765        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4766                parse_dirstat_opt(options, "files");
4767                return parse_dirstat_opt(options, arg);
4768        }
4769        else if (!strcmp(arg, "--check"))
4770                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4771        else if (!strcmp(arg, "--summary"))
4772                options->output_format |= DIFF_FORMAT_SUMMARY;
4773        else if (!strcmp(arg, "--patch-with-stat")) {
4774                enable_patch_output(&options->output_format);
4775                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4776        } else if (!strcmp(arg, "--name-only"))
4777                options->output_format |= DIFF_FORMAT_NAME;
4778        else if (!strcmp(arg, "--name-status"))
4779                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4780        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4781                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4782        else if (starts_with(arg, "--stat"))
4783                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4784                return stat_opt(options, av);
4785        else if (!strcmp(arg, "--compact-summary")) {
4786                 options->flags.stat_with_summary = 1;
4787                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4788        } else if (!strcmp(arg, "--no-compact-summary"))
4789                 options->flags.stat_with_summary = 0;
4790
4791        /* renames options */
4792        else if (starts_with(arg, "-B") ||
4793                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
4794                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4795                        return error("invalid argument to -B: %s", arg+2);
4796        }
4797        else if (starts_with(arg, "-M") ||
4798                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
4799                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4800                        return error("invalid argument to -M: %s", arg+2);
4801                options->detect_rename = DIFF_DETECT_RENAME;
4802        }
4803        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4804                options->irreversible_delete = 1;
4805        }
4806        else if (starts_with(arg, "-C") ||
4807                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
4808                if (options->detect_rename == DIFF_DETECT_COPY)
4809                        options->flags.find_copies_harder = 1;
4810                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4811                        return error("invalid argument to -C: %s", arg+2);
4812                options->detect_rename = DIFF_DETECT_COPY;
4813        }
4814        else if (!strcmp(arg, "--no-renames"))
4815                options->detect_rename = 0;
4816        else if (!strcmp(arg, "--rename-empty"))
4817                options->flags.rename_empty = 1;
4818        else if (!strcmp(arg, "--no-rename-empty"))
4819                options->flags.rename_empty = 0;
4820        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
4821                options->flags.relative_name = 1;
4822                if (arg)
4823                        options->prefix = arg;
4824        }
4825
4826        /* xdiff options */
4827        else if (!strcmp(arg, "--minimal"))
4828                DIFF_XDL_SET(options, NEED_MINIMAL);
4829        else if (!strcmp(arg, "--no-minimal"))
4830                DIFF_XDL_CLR(options, NEED_MINIMAL);
4831        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4832                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4833        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4834                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4835        else if (!strcmp(arg, "--ignore-space-at-eol"))
4836                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4837        else if (!strcmp(arg, "--ignore-cr-at-eol"))
4838                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
4839        else if (!strcmp(arg, "--ignore-blank-lines"))
4840                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4841        else if (!strcmp(arg, "--indent-heuristic"))
4842                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4843        else if (!strcmp(arg, "--no-indent-heuristic"))
4844                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4845        else if (!strcmp(arg, "--patience")) {
4846                int i;
4847                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4848                /*
4849                 * Both --patience and --anchored use PATIENCE_DIFF
4850                 * internally, so remove any anchors previously
4851                 * specified.
4852                 */
4853                for (i = 0; i < options->anchors_nr; i++)
4854                        free(options->anchors[i]);
4855                options->anchors_nr = 0;
4856        } else if (!strcmp(arg, "--histogram"))
4857                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4858        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4859                long value = parse_algorithm_value(optarg);
4860                if (value < 0)
4861                        return error("option diff-algorithm accepts \"myers\", "
4862                                     "\"minimal\", \"patience\" and \"histogram\"");
4863                /* clear out previous settings */
4864                DIFF_XDL_CLR(options, NEED_MINIMAL);
4865                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4866                options->xdl_opts |= value;
4867                return argcount;
4868        } else if (skip_prefix(arg, "--anchored=", &arg)) {
4869                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4870                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
4871                           options->anchors_alloc);
4872                options->anchors[options->anchors_nr++] = xstrdup(arg);
4873        }
4874
4875        /* flags options */
4876        else if (!strcmp(arg, "--binary")) {
4877                enable_patch_output(&options->output_format);
4878                options->flags.binary = 1;
4879        }
4880        else if (!strcmp(arg, "--full-index"))
4881                options->flags.full_index = 1;
4882        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4883                options->flags.text = 1;
4884        else if (!strcmp(arg, "-R"))
4885                options->flags.reverse_diff = 1;
4886        else if (!strcmp(arg, "--find-copies-harder"))
4887                options->flags.find_copies_harder = 1;
4888        else if (!strcmp(arg, "--follow"))
4889                options->flags.follow_renames = 1;
4890        else if (!strcmp(arg, "--no-follow")) {
4891                options->flags.follow_renames = 0;
4892                options->flags.default_follow_renames = 0;
4893        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
4894                int value = git_config_colorbool(NULL, arg);
4895                if (value < 0)
4896                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4897                options->use_color = value;
4898        }
4899        else if (!strcmp(arg, "--no-color"))
4900                options->use_color = 0;
4901        else if (!strcmp(arg, "--color-moved")) {
4902                if (diff_color_moved_default)
4903                        options->color_moved = diff_color_moved_default;
4904                if (options->color_moved == COLOR_MOVED_NO)
4905                        options->color_moved = COLOR_MOVED_DEFAULT;
4906        } else if (!strcmp(arg, "--no-color-moved"))
4907                options->color_moved = COLOR_MOVED_NO;
4908        else if (skip_prefix(arg, "--color-moved=", &arg)) {
4909                int cm = parse_color_moved(arg);
4910                if (cm < 0)
4911                        die("bad --color-moved argument: %s", arg);
4912                options->color_moved = cm;
4913        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
4914                options->color_moved_ws_handling = parse_color_moved_ws(arg);
4915        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
4916                options->use_color = 1;
4917                options->word_diff = DIFF_WORDS_COLOR;
4918        }
4919        else if (!strcmp(arg, "--word-diff")) {
4920                if (options->word_diff == DIFF_WORDS_NONE)
4921                        options->word_diff = DIFF_WORDS_PLAIN;
4922        }
4923        else if (skip_prefix(arg, "--word-diff=", &arg)) {
4924                if (!strcmp(arg, "plain"))
4925                        options->word_diff = DIFF_WORDS_PLAIN;
4926                else if (!strcmp(arg, "color")) {
4927                        options->use_color = 1;
4928                        options->word_diff = DIFF_WORDS_COLOR;
4929                }
4930                else if (!strcmp(arg, "porcelain"))
4931                        options->word_diff = DIFF_WORDS_PORCELAIN;
4932                else if (!strcmp(arg, "none"))
4933                        options->word_diff = DIFF_WORDS_NONE;
4934                else
4935                        die("bad --word-diff argument: %s", arg);
4936        }
4937        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
4938                if (options->word_diff == DIFF_WORDS_NONE)
4939                        options->word_diff = DIFF_WORDS_PLAIN;
4940                options->word_regex = optarg;
4941                return argcount;
4942        }
4943        else if (!strcmp(arg, "--exit-code"))
4944                options->flags.exit_with_status = 1;
4945        else if (!strcmp(arg, "--quiet"))
4946                options->flags.quick = 1;
4947        else if (!strcmp(arg, "--ext-diff"))
4948                options->flags.allow_external = 1;
4949        else if (!strcmp(arg, "--no-ext-diff"))
4950                options->flags.allow_external = 0;
4951        else if (!strcmp(arg, "--textconv")) {
4952                options->flags.allow_textconv = 1;
4953                options->flags.textconv_set_via_cmdline = 1;
4954        } else if (!strcmp(arg, "--no-textconv"))
4955                options->flags.allow_textconv = 0;
4956        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
4957                options->flags.override_submodule_config = 1;
4958                handle_ignore_submodules_arg(options, arg);
4959        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
4960                return parse_submodule_opt(options, arg);
4961        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
4962                return parse_ws_error_highlight_opt(options, arg);
4963        else if (!strcmp(arg, "--ita-invisible-in-index"))
4964                options->ita_invisible_in_index = 1;
4965        else if (!strcmp(arg, "--ita-visible-in-index"))
4966                options->ita_invisible_in_index = 0;
4967
4968        /* misc options */
4969        else if (!strcmp(arg, "-z"))
4970                options->line_termination = 0;
4971        else if ((argcount = short_opt('l', av, &optarg))) {
4972                options->rename_limit = strtoul(optarg, NULL, 10);
4973                return argcount;
4974        }
4975        else if ((argcount = short_opt('S', av, &optarg))) {
4976                options->pickaxe = optarg;
4977                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
4978                return argcount;
4979        } else if ((argcount = short_opt('G', av, &optarg))) {
4980                options->pickaxe = optarg;
4981                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
4982                return argcount;
4983        }
4984        else if (!strcmp(arg, "--pickaxe-all"))
4985                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
4986        else if (!strcmp(arg, "--pickaxe-regex"))
4987                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
4988        else if ((argcount = short_opt('O', av, &optarg))) {
4989                options->orderfile = prefix_filename(prefix, optarg);
4990                return argcount;
4991        } else if (skip_prefix(arg, "--find-object=", &arg))
4992                return parse_objfind_opt(options, arg);
4993        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
4994                int offending = parse_diff_filter_opt(optarg, options);
4995                if (offending)
4996                        die("unknown change class '%c' in --diff-filter=%s",
4997                            offending, optarg);
4998                return argcount;
4999        }
5000        else if (!strcmp(arg, "--no-abbrev"))
5001                options->abbrev = 0;
5002        else if (!strcmp(arg, "--abbrev"))
5003                options->abbrev = DEFAULT_ABBREV;
5004        else if (skip_prefix(arg, "--abbrev=", &arg)) {
5005                options->abbrev = strtoul(arg, NULL, 10);
5006                if (options->abbrev < MINIMUM_ABBREV)
5007                        options->abbrev = MINIMUM_ABBREV;
5008                else if (the_hash_algo->hexsz < options->abbrev)
5009                        options->abbrev = the_hash_algo->hexsz;
5010        }
5011        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5012                options->a_prefix = optarg;
5013                return argcount;
5014        }
5015        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5016                options->line_prefix = optarg;
5017                options->line_prefix_length = strlen(options->line_prefix);
5018                graph_setup_line_prefix(options);
5019                return argcount;
5020        }
5021        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5022                options->b_prefix = optarg;
5023                return argcount;
5024        }
5025        else if (!strcmp(arg, "--no-prefix"))
5026                options->a_prefix = options->b_prefix = "";
5027        else if (opt_arg(arg, '\0', "inter-hunk-context",
5028                         &options->interhunkcontext))
5029                ;
5030        else if (!strcmp(arg, "-W"))
5031                options->flags.funccontext = 1;
5032        else if (!strcmp(arg, "--function-context"))
5033                options->flags.funccontext = 1;
5034        else if (!strcmp(arg, "--no-function-context"))
5035                options->flags.funccontext = 0;
5036        else if ((argcount = parse_long_opt("output", av, &optarg))) {
5037                char *path = prefix_filename(prefix, optarg);
5038                options->file = xfopen(path, "w");
5039                options->close_file = 1;
5040                if (options->use_color != GIT_COLOR_ALWAYS)
5041                        options->use_color = GIT_COLOR_NEVER;
5042                free(path);
5043                return argcount;
5044        } else
5045                return 0;
5046        return 1;
5047}
5048
5049int parse_rename_score(const char **cp_p)
5050{
5051        unsigned long num, scale;
5052        int ch, dot;
5053        const char *cp = *cp_p;
5054
5055        num = 0;
5056        scale = 1;
5057        dot = 0;
5058        for (;;) {
5059                ch = *cp;
5060                if ( !dot && ch == '.' ) {
5061                        scale = 1;
5062                        dot = 1;
5063                } else if ( ch == '%' ) {
5064                        scale = dot ? scale*100 : 100;
5065                        cp++;   /* % is always at the end */
5066                        break;
5067                } else if ( ch >= '0' && ch <= '9' ) {
5068                        if ( scale < 100000 ) {
5069                                scale *= 10;
5070                                num = (num*10) + (ch-'0');
5071                        }
5072                } else {
5073                        break;
5074                }
5075                cp++;
5076        }
5077        *cp_p = cp;
5078
5079        /* user says num divided by scale and we say internally that
5080         * is MAX_SCORE * num / scale.
5081         */
5082        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5083}
5084
5085static int diff_scoreopt_parse(const char *opt)
5086{
5087        int opt1, opt2, cmd;
5088
5089        if (*opt++ != '-')
5090                return -1;
5091        cmd = *opt++;
5092        if (cmd == '-') {
5093                /* convert the long-form arguments into short-form versions */
5094                if (skip_prefix(opt, "break-rewrites", &opt)) {
5095                        if (*opt == 0 || *opt++ == '=')
5096                                cmd = 'B';
5097                } else if (skip_prefix(opt, "find-copies", &opt)) {
5098                        if (*opt == 0 || *opt++ == '=')
5099                                cmd = 'C';
5100                } else if (skip_prefix(opt, "find-renames", &opt)) {
5101                        if (*opt == 0 || *opt++ == '=')
5102                                cmd = 'M';
5103                }
5104        }
5105        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
5106                return -1; /* that is not a -M, -C, or -B option */
5107
5108        opt1 = parse_rename_score(&opt);
5109        if (cmd != 'B')
5110                opt2 = 0;
5111        else {
5112                if (*opt == 0)
5113                        opt2 = 0;
5114                else if (*opt != '/')
5115                        return -1; /* we expect -B80/99 or -B80 */
5116                else {
5117                        opt++;
5118                        opt2 = parse_rename_score(&opt);
5119                }
5120        }
5121        if (*opt != 0)
5122                return -1;
5123        return opt1 | (opt2 << 16);
5124}
5125
5126struct diff_queue_struct diff_queued_diff;
5127
5128void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5129{
5130        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5131        queue->queue[queue->nr++] = dp;
5132}
5133
5134struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5135                                 struct diff_filespec *one,
5136                                 struct diff_filespec *two)
5137{
5138        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5139        dp->one = one;
5140        dp->two = two;
5141        if (queue)
5142                diff_q(queue, dp);
5143        return dp;
5144}
5145
5146void diff_free_filepair(struct diff_filepair *p)
5147{
5148        free_filespec(p->one);
5149        free_filespec(p->two);
5150        free(p);
5151}
5152
5153const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5154{
5155        int abblen;
5156        const char *abbrev;
5157
5158        /* Do we want all 40 hex characters? */
5159        if (len == the_hash_algo->hexsz)
5160                return oid_to_hex(oid);
5161
5162        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5163        abbrev = diff_abbrev_oid(oid, len);
5164
5165        if (!print_sha1_ellipsis())
5166                return abbrev;
5167
5168        abblen = strlen(abbrev);
5169
5170        /*
5171         * In well-behaved cases, where the abbreviated result is the
5172         * same as the requested length, append three dots after the
5173         * abbreviation (hence the whole logic is limited to the case
5174         * where abblen < 37); when the actual abbreviated result is a
5175         * bit longer than the requested length, we reduce the number
5176         * of dots so that they match the well-behaved ones.  However,
5177         * if the actual abbreviation is longer than the requested
5178         * length by more than three, we give up on aligning, and add
5179         * three dots anyway, to indicate that the output is not the
5180         * full object name.  Yes, this may be suboptimal, but this
5181         * appears only in "diff --raw --abbrev" output and it is not
5182         * worth the effort to change it now.  Note that this would
5183         * likely to work fine when the automatic sizing of default
5184         * abbreviation length is used--we would be fed -1 in "len" in
5185         * that case, and will end up always appending three-dots, but
5186         * the automatic sizing is supposed to give abblen that ensures
5187         * uniqueness across all objects (statistically speaking).
5188         */
5189        if (abblen < the_hash_algo->hexsz - 3) {
5190                static char hex[GIT_MAX_HEXSZ + 1];
5191                if (len < abblen && abblen <= len + 2)
5192                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5193                else
5194                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5195                return hex;
5196        }
5197
5198        return oid_to_hex(oid);
5199}
5200
5201static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5202{
5203        int line_termination = opt->line_termination;
5204        int inter_name_termination = line_termination ? '\t' : '\0';
5205
5206        fprintf(opt->file, "%s", diff_line_prefix(opt));
5207        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5208                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5209                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5210                fprintf(opt->file, "%s ",
5211                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5212        }
5213        if (p->score) {
5214                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5215                        inter_name_termination);
5216        } else {
5217                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5218        }
5219
5220        if (p->status == DIFF_STATUS_COPIED ||
5221            p->status == DIFF_STATUS_RENAMED) {
5222                const char *name_a, *name_b;
5223                name_a = p->one->path;
5224                name_b = p->two->path;
5225                strip_prefix(opt->prefix_length, &name_a, &name_b);
5226                write_name_quoted(name_a, opt->file, inter_name_termination);
5227                write_name_quoted(name_b, opt->file, line_termination);
5228        } else {
5229                const char *name_a, *name_b;
5230                name_a = p->one->mode ? p->one->path : p->two->path;
5231                name_b = NULL;
5232                strip_prefix(opt->prefix_length, &name_a, &name_b);
5233                write_name_quoted(name_a, opt->file, line_termination);
5234        }
5235}
5236
5237int diff_unmodified_pair(struct diff_filepair *p)
5238{
5239        /* This function is written stricter than necessary to support
5240         * the currently implemented transformers, but the idea is to
5241         * let transformers to produce diff_filepairs any way they want,
5242         * and filter and clean them up here before producing the output.
5243         */
5244        struct diff_filespec *one = p->one, *two = p->two;
5245
5246        if (DIFF_PAIR_UNMERGED(p))
5247                return 0; /* unmerged is interesting */
5248
5249        /* deletion, addition, mode or type change
5250         * and rename are all interesting.
5251         */
5252        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5253            DIFF_PAIR_MODE_CHANGED(p) ||
5254            strcmp(one->path, two->path))
5255                return 0;
5256
5257        /* both are valid and point at the same path.  that is, we are
5258         * dealing with a change.
5259         */
5260        if (one->oid_valid && two->oid_valid &&
5261            !oidcmp(&one->oid, &two->oid) &&
5262            !one->dirty_submodule && !two->dirty_submodule)
5263                return 1; /* no change */
5264        if (!one->oid_valid && !two->oid_valid)
5265                return 1; /* both look at the same file on the filesystem. */
5266        return 0;
5267}
5268
5269static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5270{
5271        if (diff_unmodified_pair(p))
5272                return;
5273
5274        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5275            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5276                return; /* no tree diffs in patch format */
5277
5278        run_diff(p, o);
5279}
5280
5281static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5282                            struct diffstat_t *diffstat)
5283{
5284        if (diff_unmodified_pair(p))
5285                return;
5286
5287        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5288            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5289                return; /* no useful stat for tree diffs */
5290
5291        run_diffstat(p, o, diffstat);
5292}
5293
5294static void diff_flush_checkdiff(struct diff_filepair *p,
5295                struct diff_options *o)
5296{
5297        if (diff_unmodified_pair(p))
5298                return;
5299
5300        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5301            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5302                return; /* nothing to check in tree diffs */
5303
5304        run_checkdiff(p, o);
5305}
5306
5307int diff_queue_is_empty(void)
5308{
5309        struct diff_queue_struct *q = &diff_queued_diff;
5310        int i;
5311        for (i = 0; i < q->nr; i++)
5312                if (!diff_unmodified_pair(q->queue[i]))
5313                        return 0;
5314        return 1;
5315}
5316
5317#if DIFF_DEBUG
5318void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5319{
5320        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5321                x, one ? one : "",
5322                s->path,
5323                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5324                s->mode,
5325                s->oid_valid ? oid_to_hex(&s->oid) : "");
5326        fprintf(stderr, "queue[%d] %s size %lu\n",
5327                x, one ? one : "",
5328                s->size);
5329}
5330
5331void diff_debug_filepair(const struct diff_filepair *p, int i)
5332{
5333        diff_debug_filespec(p->one, i, "one");
5334        diff_debug_filespec(p->two, i, "two");
5335        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5336                p->score, p->status ? p->status : '?',
5337                p->one->rename_used, p->broken_pair);
5338}
5339
5340void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5341{
5342        int i;
5343        if (msg)
5344                fprintf(stderr, "%s\n", msg);
5345        fprintf(stderr, "q->nr = %d\n", q->nr);
5346        for (i = 0; i < q->nr; i++) {
5347                struct diff_filepair *p = q->queue[i];
5348                diff_debug_filepair(p, i);
5349        }
5350}
5351#endif
5352
5353static void diff_resolve_rename_copy(void)
5354{
5355        int i;
5356        struct diff_filepair *p;
5357        struct diff_queue_struct *q = &diff_queued_diff;
5358
5359        diff_debug_queue("resolve-rename-copy", q);
5360
5361        for (i = 0; i < q->nr; i++) {
5362                p = q->queue[i];
5363                p->status = 0; /* undecided */
5364                if (DIFF_PAIR_UNMERGED(p))
5365                        p->status = DIFF_STATUS_UNMERGED;
5366                else if (!DIFF_FILE_VALID(p->one))
5367                        p->status = DIFF_STATUS_ADDED;
5368                else if (!DIFF_FILE_VALID(p->two))
5369                        p->status = DIFF_STATUS_DELETED;
5370                else if (DIFF_PAIR_TYPE_CHANGED(p))
5371                        p->status = DIFF_STATUS_TYPE_CHANGED;
5372
5373                /* from this point on, we are dealing with a pair
5374                 * whose both sides are valid and of the same type, i.e.
5375                 * either in-place edit or rename/copy edit.
5376                 */
5377                else if (DIFF_PAIR_RENAME(p)) {
5378                        /*
5379                         * A rename might have re-connected a broken
5380                         * pair up, causing the pathnames to be the
5381                         * same again. If so, that's not a rename at
5382                         * all, just a modification..
5383                         *
5384                         * Otherwise, see if this source was used for
5385                         * multiple renames, in which case we decrement
5386                         * the count, and call it a copy.
5387                         */
5388                        if (!strcmp(p->one->path, p->two->path))
5389                                p->status = DIFF_STATUS_MODIFIED;
5390                        else if (--p->one->rename_used > 0)
5391                                p->status = DIFF_STATUS_COPIED;
5392                        else
5393                                p->status = DIFF_STATUS_RENAMED;
5394                }
5395                else if (oidcmp(&p->one->oid, &p->two->oid) ||
5396                         p->one->mode != p->two->mode ||
5397                         p->one->dirty_submodule ||
5398                         p->two->dirty_submodule ||
5399                         is_null_oid(&p->one->oid))
5400                        p->status = DIFF_STATUS_MODIFIED;
5401                else {
5402                        /* This is a "no-change" entry and should not
5403                         * happen anymore, but prepare for broken callers.
5404                         */
5405                        error("feeding unmodified %s to diffcore",
5406                              p->one->path);
5407                        p->status = DIFF_STATUS_UNKNOWN;
5408                }
5409        }
5410        diff_debug_queue("resolve-rename-copy done", q);
5411}
5412
5413static int check_pair_status(struct diff_filepair *p)
5414{
5415        switch (p->status) {
5416        case DIFF_STATUS_UNKNOWN:
5417                return 0;
5418        case 0:
5419                die("internal error in diff-resolve-rename-copy");
5420        default:
5421                return 1;
5422        }
5423}
5424
5425static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5426{
5427        int fmt = opt->output_format;
5428
5429        if (fmt & DIFF_FORMAT_CHECKDIFF)
5430                diff_flush_checkdiff(p, opt);
5431        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5432                diff_flush_raw(p, opt);
5433        else if (fmt & DIFF_FORMAT_NAME) {
5434                const char *name_a, *name_b;
5435                name_a = p->two->path;
5436                name_b = NULL;
5437                strip_prefix(opt->prefix_length, &name_a, &name_b);
5438                fprintf(opt->file, "%s", diff_line_prefix(opt));
5439                write_name_quoted(name_a, opt->file, opt->line_termination);
5440        }
5441}
5442
5443static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5444{
5445        struct strbuf sb = STRBUF_INIT;
5446        if (fs->mode)
5447                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5448        else
5449                strbuf_addf(&sb, " %s ", newdelete);
5450
5451        quote_c_style(fs->path, &sb, NULL, 0);
5452        strbuf_addch(&sb, '\n');
5453        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5454                         sb.buf, sb.len, 0);
5455        strbuf_release(&sb);
5456}
5457
5458static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5459                int show_name)
5460{
5461        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5462                struct strbuf sb = STRBUF_INIT;
5463                strbuf_addf(&sb, " mode change %06o => %06o",
5464                            p->one->mode, p->two->mode);
5465                if (show_name) {
5466                        strbuf_addch(&sb, ' ');
5467                        quote_c_style(p->two->path, &sb, NULL, 0);
5468                }
5469                strbuf_addch(&sb, '\n');
5470                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5471                                 sb.buf, sb.len, 0);
5472                strbuf_release(&sb);
5473        }
5474}
5475
5476static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5477                struct diff_filepair *p)
5478{
5479        struct strbuf sb = STRBUF_INIT;
5480        struct strbuf names = STRBUF_INIT;
5481
5482        pprint_rename(&names, p->one->path, p->two->path);
5483        strbuf_addf(&sb, " %s %s (%d%%)\n",
5484                    renamecopy, names.buf, similarity_index(p));
5485        strbuf_release(&names);
5486        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5487                                 sb.buf, sb.len, 0);
5488        show_mode_change(opt, p, 0);
5489        strbuf_release(&sb);
5490}
5491
5492static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5493{
5494        switch(p->status) {
5495        case DIFF_STATUS_DELETED:
5496                show_file_mode_name(opt, "delete", p->one);
5497                break;
5498        case DIFF_STATUS_ADDED:
5499                show_file_mode_name(opt, "create", p->two);
5500                break;
5501        case DIFF_STATUS_COPIED:
5502                show_rename_copy(opt, "copy", p);
5503                break;
5504        case DIFF_STATUS_RENAMED:
5505                show_rename_copy(opt, "rename", p);
5506                break;
5507        default:
5508                if (p->score) {
5509                        struct strbuf sb = STRBUF_INIT;
5510                        strbuf_addstr(&sb, " rewrite ");
5511                        quote_c_style(p->two->path, &sb, NULL, 0);
5512                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5513                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5514                                         sb.buf, sb.len, 0);
5515                        strbuf_release(&sb);
5516                }
5517                show_mode_change(opt, p, !p->score);
5518                break;
5519        }
5520}
5521
5522struct patch_id_t {
5523        git_SHA_CTX *ctx;
5524        int patchlen;
5525};
5526
5527static int remove_space(char *line, int len)
5528{
5529        int i;
5530        char *dst = line;
5531        unsigned char c;
5532
5533        for (i = 0; i < len; i++)
5534                if (!isspace((c = line[i])))
5535                        *dst++ = c;
5536
5537        return dst - line;
5538}
5539
5540static void patch_id_consume(void *priv, char *line, unsigned long len)
5541{
5542        struct patch_id_t *data = priv;
5543        int new_len;
5544
5545        /* Ignore line numbers when computing the SHA1 of the patch */
5546        if (starts_with(line, "@@ -"))
5547                return;
5548
5549        new_len = remove_space(line, len);
5550
5551        git_SHA1_Update(data->ctx, line, new_len);
5552        data->patchlen += new_len;
5553}
5554
5555static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5556{
5557        git_SHA1_Update(ctx, str, strlen(str));
5558}
5559
5560static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5561{
5562        /* large enough for 2^32 in octal */
5563        char buf[12];
5564        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5565        git_SHA1_Update(ctx, buf, len);
5566}
5567
5568/* returns 0 upon success, and writes result into sha1 */
5569static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5570{
5571        struct diff_queue_struct *q = &diff_queued_diff;
5572        int i;
5573        git_SHA_CTX ctx;
5574        struct patch_id_t data;
5575
5576        git_SHA1_Init(&ctx);
5577        memset(&data, 0, sizeof(struct patch_id_t));
5578        data.ctx = &ctx;
5579
5580        for (i = 0; i < q->nr; i++) {
5581                xpparam_t xpp;
5582                xdemitconf_t xecfg;
5583                mmfile_t mf1, mf2;
5584                struct diff_filepair *p = q->queue[i];
5585                int len1, len2;
5586
5587                memset(&xpp, 0, sizeof(xpp));
5588                memset(&xecfg, 0, sizeof(xecfg));
5589                if (p->status == 0)
5590                        return error("internal diff status error");
5591                if (p->status == DIFF_STATUS_UNKNOWN)
5592                        continue;
5593                if (diff_unmodified_pair(p))
5594                        continue;
5595                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5596                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5597                        continue;
5598                if (DIFF_PAIR_UNMERGED(p))
5599                        continue;
5600
5601                diff_fill_oid_info(p->one);
5602                diff_fill_oid_info(p->two);
5603
5604                len1 = remove_space(p->one->path, strlen(p->one->path));
5605                len2 = remove_space(p->two->path, strlen(p->two->path));
5606                patch_id_add_string(&ctx, "diff--git");
5607                patch_id_add_string(&ctx, "a/");
5608                git_SHA1_Update(&ctx, p->one->path, len1);
5609                patch_id_add_string(&ctx, "b/");
5610                git_SHA1_Update(&ctx, p->two->path, len2);
5611
5612                if (p->one->mode == 0) {
5613                        patch_id_add_string(&ctx, "newfilemode");
5614                        patch_id_add_mode(&ctx, p->two->mode);
5615                        patch_id_add_string(&ctx, "---/dev/null");
5616                        patch_id_add_string(&ctx, "+++b/");
5617                        git_SHA1_Update(&ctx, p->two->path, len2);
5618                } else if (p->two->mode == 0) {
5619                        patch_id_add_string(&ctx, "deletedfilemode");
5620                        patch_id_add_mode(&ctx, p->one->mode);
5621                        patch_id_add_string(&ctx, "---a/");
5622                        git_SHA1_Update(&ctx, p->one->path, len1);
5623                        patch_id_add_string(&ctx, "+++/dev/null");
5624                } else {
5625                        patch_id_add_string(&ctx, "---a/");
5626                        git_SHA1_Update(&ctx, p->one->path, len1);
5627                        patch_id_add_string(&ctx, "+++b/");
5628                        git_SHA1_Update(&ctx, p->two->path, len2);
5629                }
5630
5631                if (diff_header_only)
5632                        continue;
5633
5634                if (fill_mmfile(&mf1, p->one) < 0 ||
5635                    fill_mmfile(&mf2, p->two) < 0)
5636                        return error("unable to read files to diff");
5637
5638                if (diff_filespec_is_binary(p->one) ||
5639                    diff_filespec_is_binary(p->two)) {
5640                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5641                                        GIT_SHA1_HEXSZ);
5642                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5643                                        GIT_SHA1_HEXSZ);
5644                        continue;
5645                }
5646
5647                xpp.flags = 0;
5648                xecfg.ctxlen = 3;
5649                xecfg.flags = 0;
5650                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
5651                                  &xpp, &xecfg))
5652                        return error("unable to generate patch-id diff for %s",
5653                                     p->one->path);
5654        }
5655
5656        git_SHA1_Final(oid->hash, &ctx);
5657        return 0;
5658}
5659
5660int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5661{
5662        struct diff_queue_struct *q = &diff_queued_diff;
5663        int i;
5664        int result = diff_get_patch_id(options, oid, diff_header_only);
5665
5666        for (i = 0; i < q->nr; i++)
5667                diff_free_filepair(q->queue[i]);
5668
5669        free(q->queue);
5670        DIFF_QUEUE_CLEAR(q);
5671
5672        return result;
5673}
5674
5675static int is_summary_empty(const struct diff_queue_struct *q)
5676{
5677        int i;
5678
5679        for (i = 0; i < q->nr; i++) {
5680                const struct diff_filepair *p = q->queue[i];
5681
5682                switch (p->status) {
5683                case DIFF_STATUS_DELETED:
5684                case DIFF_STATUS_ADDED:
5685                case DIFF_STATUS_COPIED:
5686                case DIFF_STATUS_RENAMED:
5687                        return 0;
5688                default:
5689                        if (p->score)
5690                                return 0;
5691                        if (p->one->mode && p->two->mode &&
5692                            p->one->mode != p->two->mode)
5693                                return 0;
5694                        break;
5695                }
5696        }
5697        return 1;
5698}
5699
5700static const char rename_limit_warning[] =
5701N_("inexact rename detection was skipped due to too many files.");
5702
5703static const char degrade_cc_to_c_warning[] =
5704N_("only found copies from modified paths due to too many files.");
5705
5706static const char rename_limit_advice[] =
5707N_("you may want to set your %s variable to at least "
5708   "%d and retry the command.");
5709
5710void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5711{
5712        fflush(stdout);
5713        if (degraded_cc)
5714                warning(_(degrade_cc_to_c_warning));
5715        else if (needed)
5716                warning(_(rename_limit_warning));
5717        else
5718                return;
5719        if (0 < needed)
5720                warning(_(rename_limit_advice), varname, needed);
5721}
5722
5723static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5724{
5725        int i;
5726        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5727        struct diff_queue_struct *q = &diff_queued_diff;
5728
5729        if (WSEH_NEW & WS_RULE_MASK)
5730                BUG("WS rules bit mask overlaps with diff symbol flags");
5731
5732        if (o->color_moved)
5733                o->emitted_symbols = &esm;
5734
5735        for (i = 0; i < q->nr; i++) {
5736                struct diff_filepair *p = q->queue[i];
5737                if (check_pair_status(p))
5738                        diff_flush_patch(p, o);
5739        }
5740
5741        if (o->emitted_symbols) {
5742                if (o->color_moved) {
5743                        struct hashmap add_lines, del_lines;
5744
5745                        if (o->color_moved_ws_handling &
5746                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
5747                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
5748
5749                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
5750                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
5751
5752                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5753                        mark_color_as_moved(o, &add_lines, &del_lines);
5754                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5755                                dim_moved_lines(o);
5756
5757                        hashmap_free(&add_lines, 0);
5758                        hashmap_free(&del_lines, 0);
5759                }
5760
5761                for (i = 0; i < esm.nr; i++)
5762                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5763
5764                for (i = 0; i < esm.nr; i++)
5765                        free((void *)esm.buf[i].line);
5766        }
5767        esm.nr = 0;
5768}
5769
5770void diff_flush(struct diff_options *options)
5771{
5772        struct diff_queue_struct *q = &diff_queued_diff;
5773        int i, output_format = options->output_format;
5774        int separator = 0;
5775        int dirstat_by_line = 0;
5776
5777        /*
5778         * Order: raw, stat, summary, patch
5779         * or:    name/name-status/checkdiff (other bits clear)
5780         */
5781        if (!q->nr)
5782                goto free_queue;
5783
5784        if (output_format & (DIFF_FORMAT_RAW |
5785                             DIFF_FORMAT_NAME |
5786                             DIFF_FORMAT_NAME_STATUS |
5787                             DIFF_FORMAT_CHECKDIFF)) {
5788                for (i = 0; i < q->nr; i++) {
5789                        struct diff_filepair *p = q->queue[i];
5790                        if (check_pair_status(p))
5791                                flush_one_pair(p, options);
5792                }
5793                separator++;
5794        }
5795
5796        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5797                dirstat_by_line = 1;
5798
5799        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5800            dirstat_by_line) {
5801                struct diffstat_t diffstat;
5802
5803                memset(&diffstat, 0, sizeof(struct diffstat_t));
5804                for (i = 0; i < q->nr; i++) {
5805                        struct diff_filepair *p = q->queue[i];
5806                        if (check_pair_status(p))
5807                                diff_flush_stat(p, options, &diffstat);
5808                }
5809                if (output_format & DIFF_FORMAT_NUMSTAT)
5810                        show_numstat(&diffstat, options);
5811                if (output_format & DIFF_FORMAT_DIFFSTAT)
5812                        show_stats(&diffstat, options);
5813                if (output_format & DIFF_FORMAT_SHORTSTAT)
5814                        show_shortstats(&diffstat, options);
5815                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5816                        show_dirstat_by_line(&diffstat, options);
5817                free_diffstat_info(&diffstat);
5818                separator++;
5819        }
5820        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5821                show_dirstat(options);
5822
5823        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5824                for (i = 0; i < q->nr; i++) {
5825                        diff_summary(options, q->queue[i]);
5826                }
5827                separator++;
5828        }
5829
5830        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5831            options->flags.exit_with_status &&
5832            options->flags.diff_from_contents) {
5833                /*
5834                 * run diff_flush_patch for the exit status. setting
5835                 * options->file to /dev/null should be safe, because we
5836                 * aren't supposed to produce any output anyway.
5837                 */
5838                if (options->close_file)
5839                        fclose(options->file);
5840                options->file = xfopen("/dev/null", "w");
5841                options->close_file = 1;
5842                options->color_moved = 0;
5843                for (i = 0; i < q->nr; i++) {
5844                        struct diff_filepair *p = q->queue[i];
5845                        if (check_pair_status(p))
5846                                diff_flush_patch(p, options);
5847                        if (options->found_changes)
5848                                break;
5849                }
5850        }
5851
5852        if (output_format & DIFF_FORMAT_PATCH) {
5853                if (separator) {
5854                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5855                        if (options->stat_sep)
5856                                /* attach patch instead of inline */
5857                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5858                                                 NULL, 0, 0);
5859                }
5860
5861                diff_flush_patch_all_file_pairs(options);
5862        }
5863
5864        if (output_format & DIFF_FORMAT_CALLBACK)
5865                options->format_callback(q, options, options->format_callback_data);
5866
5867        for (i = 0; i < q->nr; i++)
5868                diff_free_filepair(q->queue[i]);
5869free_queue:
5870        free(q->queue);
5871        DIFF_QUEUE_CLEAR(q);
5872        if (options->close_file)
5873                fclose(options->file);
5874
5875        /*
5876         * Report the content-level differences with HAS_CHANGES;
5877         * diff_addremove/diff_change does not set the bit when
5878         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5879         */
5880        if (options->flags.diff_from_contents) {
5881                if (options->found_changes)
5882                        options->flags.has_changes = 1;
5883                else
5884                        options->flags.has_changes = 0;
5885        }
5886}
5887
5888static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5889{
5890        return (((p->status == DIFF_STATUS_MODIFIED) &&
5891                 ((p->score &&
5892                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5893                  (!p->score &&
5894                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5895                ((p->status != DIFF_STATUS_MODIFIED) &&
5896                 filter_bit_tst(p->status, options)));
5897}
5898
5899static void diffcore_apply_filter(struct diff_options *options)
5900{
5901        int i;
5902        struct diff_queue_struct *q = &diff_queued_diff;
5903        struct diff_queue_struct outq;
5904
5905        DIFF_QUEUE_CLEAR(&outq);
5906
5907        if (!options->filter)
5908                return;
5909
5910        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
5911                int found;
5912                for (i = found = 0; !found && i < q->nr; i++) {
5913                        if (match_filter(options, q->queue[i]))
5914                                found++;
5915                }
5916                if (found)
5917                        return;
5918
5919                /* otherwise we will clear the whole queue
5920                 * by copying the empty outq at the end of this
5921                 * function, but first clear the current entries
5922                 * in the queue.
5923                 */
5924                for (i = 0; i < q->nr; i++)
5925                        diff_free_filepair(q->queue[i]);
5926        }
5927        else {
5928                /* Only the matching ones */
5929                for (i = 0; i < q->nr; i++) {
5930                        struct diff_filepair *p = q->queue[i];
5931                        if (match_filter(options, p))
5932                                diff_q(&outq, p);
5933                        else
5934                                diff_free_filepair(p);
5935                }
5936        }
5937        free(q->queue);
5938        *q = outq;
5939}
5940
5941/* Check whether two filespecs with the same mode and size are identical */
5942static int diff_filespec_is_identical(struct diff_filespec *one,
5943                                      struct diff_filespec *two)
5944{
5945        if (S_ISGITLINK(one->mode))
5946                return 0;
5947        if (diff_populate_filespec(one, 0))
5948                return 0;
5949        if (diff_populate_filespec(two, 0))
5950                return 0;
5951        return !memcmp(one->data, two->data, one->size);
5952}
5953
5954static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
5955{
5956        if (p->done_skip_stat_unmatch)
5957                return p->skip_stat_unmatch_result;
5958
5959        p->done_skip_stat_unmatch = 1;
5960        p->skip_stat_unmatch_result = 0;
5961        /*
5962         * 1. Entries that come from stat info dirtiness
5963         *    always have both sides (iow, not create/delete),
5964         *    one side of the object name is unknown, with
5965         *    the same mode and size.  Keep the ones that
5966         *    do not match these criteria.  They have real
5967         *    differences.
5968         *
5969         * 2. At this point, the file is known to be modified,
5970         *    with the same mode and size, and the object
5971         *    name of one side is unknown.  Need to inspect
5972         *    the identical contents.
5973         */
5974        if (!DIFF_FILE_VALID(p->one) || /* (1) */
5975            !DIFF_FILE_VALID(p->two) ||
5976            (p->one->oid_valid && p->two->oid_valid) ||
5977            (p->one->mode != p->two->mode) ||
5978            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
5979            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
5980            (p->one->size != p->two->size) ||
5981            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
5982                p->skip_stat_unmatch_result = 1;
5983        return p->skip_stat_unmatch_result;
5984}
5985
5986static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
5987{
5988        int i;
5989        struct diff_queue_struct *q = &diff_queued_diff;
5990        struct diff_queue_struct outq;
5991        DIFF_QUEUE_CLEAR(&outq);
5992
5993        for (i = 0; i < q->nr; i++) {
5994                struct diff_filepair *p = q->queue[i];
5995
5996                if (diff_filespec_check_stat_unmatch(p))
5997                        diff_q(&outq, p);
5998                else {
5999                        /*
6000                         * The caller can subtract 1 from skip_stat_unmatch
6001                         * to determine how many paths were dirty only
6002                         * due to stat info mismatch.
6003                         */
6004                        if (!diffopt->flags.no_index)
6005                                diffopt->skip_stat_unmatch++;
6006                        diff_free_filepair(p);
6007                }
6008        }
6009        free(q->queue);
6010        *q = outq;
6011}
6012
6013static int diffnamecmp(const void *a_, const void *b_)
6014{
6015        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6016        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6017        const char *name_a, *name_b;
6018
6019        name_a = a->one ? a->one->path : a->two->path;
6020        name_b = b->one ? b->one->path : b->two->path;
6021        return strcmp(name_a, name_b);
6022}
6023
6024void diffcore_fix_diff_index(struct diff_options *options)
6025{
6026        struct diff_queue_struct *q = &diff_queued_diff;
6027        QSORT(q->queue, q->nr, diffnamecmp);
6028}
6029
6030void diffcore_std(struct diff_options *options)
6031{
6032        /* NOTE please keep the following in sync with diff_tree_combined() */
6033        if (options->skip_stat_unmatch)
6034                diffcore_skip_stat_unmatch(options);
6035        if (!options->found_follow) {
6036                /* See try_to_follow_renames() in tree-diff.c */
6037                if (options->break_opt != -1)
6038                        diffcore_break(options->break_opt);
6039                if (options->detect_rename)
6040                        diffcore_rename(options);
6041                if (options->break_opt != -1)
6042                        diffcore_merge_broken();
6043        }
6044        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6045                diffcore_pickaxe(options);
6046        if (options->orderfile)
6047                diffcore_order(options->orderfile);
6048        if (!options->found_follow)
6049                /* See try_to_follow_renames() in tree-diff.c */
6050                diff_resolve_rename_copy();
6051        diffcore_apply_filter(options);
6052
6053        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6054                options->flags.has_changes = 1;
6055        else
6056                options->flags.has_changes = 0;
6057
6058        options->found_follow = 0;
6059}
6060
6061int diff_result_code(struct diff_options *opt, int status)
6062{
6063        int result = 0;
6064
6065        diff_warn_rename_limit("diff.renameLimit",
6066                               opt->needed_rename_limit,
6067                               opt->degraded_cc_to_c);
6068        if (!opt->flags.exit_with_status &&
6069            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6070                return status;
6071        if (opt->flags.exit_with_status &&
6072            opt->flags.has_changes)
6073                result |= 01;
6074        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6075            opt->flags.check_failed)
6076                result |= 02;
6077        return result;
6078}
6079
6080int diff_can_quit_early(struct diff_options *opt)
6081{
6082        return (opt->flags.quick &&
6083                !opt->filter &&
6084                opt->flags.has_changes);
6085}
6086
6087/*
6088 * Shall changes to this submodule be ignored?
6089 *
6090 * Submodule changes can be configured to be ignored separately for each path,
6091 * but that configuration can be overridden from the command line.
6092 */
6093static int is_submodule_ignored(const char *path, struct diff_options *options)
6094{
6095        int ignored = 0;
6096        struct diff_flags orig_flags = options->flags;
6097        if (!options->flags.override_submodule_config)
6098                set_diffopt_flags_from_submodule_config(options, path);
6099        if (options->flags.ignore_submodules)
6100                ignored = 1;
6101        options->flags = orig_flags;
6102        return ignored;
6103}
6104
6105void diff_addremove(struct diff_options *options,
6106                    int addremove, unsigned mode,
6107                    const struct object_id *oid,
6108                    int oid_valid,
6109                    const char *concatpath, unsigned dirty_submodule)
6110{
6111        struct diff_filespec *one, *two;
6112
6113        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6114                return;
6115
6116        /* This may look odd, but it is a preparation for
6117         * feeding "there are unchanged files which should
6118         * not produce diffs, but when you are doing copy
6119         * detection you would need them, so here they are"
6120         * entries to the diff-core.  They will be prefixed
6121         * with something like '=' or '*' (I haven't decided
6122         * which but should not make any difference).
6123         * Feeding the same new and old to diff_change()
6124         * also has the same effect.
6125         * Before the final output happens, they are pruned after
6126         * merged into rename/copy pairs as appropriate.
6127         */
6128        if (options->flags.reverse_diff)
6129                addremove = (addremove == '+' ? '-' :
6130                             addremove == '-' ? '+' : addremove);
6131
6132        if (options->prefix &&
6133            strncmp(concatpath, options->prefix, options->prefix_length))
6134                return;
6135
6136        one = alloc_filespec(concatpath);
6137        two = alloc_filespec(concatpath);
6138
6139        if (addremove != '+')
6140                fill_filespec(one, oid, oid_valid, mode);
6141        if (addremove != '-') {
6142                fill_filespec(two, oid, oid_valid, mode);
6143                two->dirty_submodule = dirty_submodule;
6144        }
6145
6146        diff_queue(&diff_queued_diff, one, two);
6147        if (!options->flags.diff_from_contents)
6148                options->flags.has_changes = 1;
6149}
6150
6151void diff_change(struct diff_options *options,
6152                 unsigned old_mode, unsigned new_mode,
6153                 const struct object_id *old_oid,
6154                 const struct object_id *new_oid,
6155                 int old_oid_valid, int new_oid_valid,
6156                 const char *concatpath,
6157                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6158{
6159        struct diff_filespec *one, *two;
6160        struct diff_filepair *p;
6161
6162        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6163            is_submodule_ignored(concatpath, options))
6164                return;
6165
6166        if (options->flags.reverse_diff) {
6167                SWAP(old_mode, new_mode);
6168                SWAP(old_oid, new_oid);
6169                SWAP(old_oid_valid, new_oid_valid);
6170                SWAP(old_dirty_submodule, new_dirty_submodule);
6171        }
6172
6173        if (options->prefix &&
6174            strncmp(concatpath, options->prefix, options->prefix_length))
6175                return;
6176
6177        one = alloc_filespec(concatpath);
6178        two = alloc_filespec(concatpath);
6179        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6180        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6181        one->dirty_submodule = old_dirty_submodule;
6182        two->dirty_submodule = new_dirty_submodule;
6183        p = diff_queue(&diff_queued_diff, one, two);
6184
6185        if (options->flags.diff_from_contents)
6186                return;
6187
6188        if (options->flags.quick && options->skip_stat_unmatch &&
6189            !diff_filespec_check_stat_unmatch(p))
6190                return;
6191
6192        options->flags.has_changes = 1;
6193}
6194
6195struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6196{
6197        struct diff_filepair *pair;
6198        struct diff_filespec *one, *two;
6199
6200        if (options->prefix &&
6201            strncmp(path, options->prefix, options->prefix_length))
6202                return NULL;
6203
6204        one = alloc_filespec(path);
6205        two = alloc_filespec(path);
6206        pair = diff_queue(&diff_queued_diff, one, two);
6207        pair->is_unmerged = 1;
6208        return pair;
6209}
6210
6211static char *run_textconv(const char *pgm, struct diff_filespec *spec,
6212                size_t *outsize)
6213{
6214        struct diff_tempfile *temp;
6215        const char *argv[3];
6216        const char **arg = argv;
6217        struct child_process child = CHILD_PROCESS_INIT;
6218        struct strbuf buf = STRBUF_INIT;
6219        int err = 0;
6220
6221        temp = prepare_temp_file(spec->path, spec);
6222        *arg++ = pgm;
6223        *arg++ = temp->name;
6224        *arg = NULL;
6225
6226        child.use_shell = 1;
6227        child.argv = argv;
6228        child.out = -1;
6229        if (start_command(&child)) {
6230                remove_tempfile();
6231                return NULL;
6232        }
6233
6234        if (strbuf_read(&buf, child.out, 0) < 0)
6235                err = error("error reading from textconv command '%s'", pgm);
6236        close(child.out);
6237
6238        if (finish_command(&child) || err) {
6239                strbuf_release(&buf);
6240                remove_tempfile();
6241                return NULL;
6242        }
6243        remove_tempfile();
6244
6245        return strbuf_detach(&buf, outsize);
6246}
6247
6248size_t fill_textconv(struct userdiff_driver *driver,
6249                     struct diff_filespec *df,
6250                     char **outbuf)
6251{
6252        size_t size;
6253
6254        if (!driver) {
6255                if (!DIFF_FILE_VALID(df)) {
6256                        *outbuf = "";
6257                        return 0;
6258                }
6259                if (diff_populate_filespec(df, 0))
6260                        die("unable to read files to diff");
6261                *outbuf = df->data;
6262                return df->size;
6263        }
6264
6265        if (!driver->textconv)
6266                BUG("fill_textconv called with non-textconv driver");
6267
6268        if (driver->textconv_cache && df->oid_valid) {
6269                *outbuf = notes_cache_get(driver->textconv_cache,
6270                                          &df->oid,
6271                                          &size);
6272                if (*outbuf)
6273                        return size;
6274        }
6275
6276        *outbuf = run_textconv(driver->textconv, df, &size);
6277        if (!*outbuf)
6278                die("unable to read files to diff");
6279
6280        if (driver->textconv_cache && df->oid_valid) {
6281                /* ignore errors, as we might be in a readonly repository */
6282                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6283                                size);
6284                /*
6285                 * we could save up changes and flush them all at the end,
6286                 * but we would need an extra call after all diffing is done.
6287                 * Since generating a cache entry is the slow path anyway,
6288                 * this extra overhead probably isn't a big deal.
6289                 */
6290                notes_cache_write(driver->textconv_cache);
6291        }
6292
6293        return size;
6294}
6295
6296int textconv_object(const char *path,
6297                    unsigned mode,
6298                    const struct object_id *oid,
6299                    int oid_valid,
6300                    char **buf,
6301                    unsigned long *buf_size)
6302{
6303        struct diff_filespec *df;
6304        struct userdiff_driver *textconv;
6305
6306        df = alloc_filespec(path);
6307        fill_filespec(df, oid, oid_valid, mode);
6308        textconv = get_textconv(df);
6309        if (!textconv) {
6310                free_filespec(df);
6311                return 0;
6312        }
6313
6314        *buf_size = fill_textconv(textconv, df, buf);
6315        free_filespec(df);
6316        return 1;
6317}
6318
6319void setup_diff_pager(struct diff_options *opt)
6320{
6321        /*
6322         * If the user asked for our exit code, then either they want --quiet
6323         * or --exit-code. We should definitely not bother with a pager in the
6324         * former case, as we will generate no output. Since we still properly
6325         * report our exit code even when a pager is run, we _could_ run a
6326         * pager with --exit-code. But since we have not done so historically,
6327         * and because it is easy to find people oneline advising "git diff
6328         * --exit-code" in hooks and other scripts, we do not do so.
6329         */
6330        if (!opt->flags.exit_with_status &&
6331            check_pager_config("diff") != 0)
6332                setup_pager();
6333}