e0d39d04da5c863b3156b4c1a801b0ca7d8e9abe
   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 "userdiff.h"
  17#include "submodule-config.h"
  18#include "submodule.h"
  19#include "ll-merge.h"
  20#include "string-list.h"
  21#include "argv-array.h"
  22#include "graph.h"
  23
  24#ifdef NO_FAST_WORKING_DIRECTORY
  25#define FAST_WORKING_DIRECTORY 0
  26#else
  27#define FAST_WORKING_DIRECTORY 1
  28#endif
  29
  30static int diff_detect_rename_default;
  31static int diff_indent_heuristic = 1;
  32static int diff_rename_limit_default = 400;
  33static int diff_suppress_blank_empty;
  34static int diff_use_color_default = -1;
  35static int diff_context_default = 3;
  36static int diff_interhunk_context_default;
  37static const char *diff_word_regex_cfg;
  38static const char *external_diff_cmd_cfg;
  39static const char *diff_order_file_cfg;
  40int diff_auto_refresh_index = 1;
  41static int diff_mnemonic_prefix;
  42static int diff_no_prefix;
  43static int diff_stat_graph_width;
  44static int diff_dirstat_permille_default = 30;
  45static struct diff_options default_diff_options;
  46static long diff_algorithm;
  47static unsigned ws_error_highlight_default = WSEH_NEW;
  48
  49static char diff_colors[][COLOR_MAXLEN] = {
  50        GIT_COLOR_RESET,
  51        GIT_COLOR_NORMAL,       /* CONTEXT */
  52        GIT_COLOR_BOLD,         /* METAINFO */
  53        GIT_COLOR_CYAN,         /* FRAGINFO */
  54        GIT_COLOR_RED,          /* OLD */
  55        GIT_COLOR_GREEN,        /* NEW */
  56        GIT_COLOR_YELLOW,       /* COMMIT */
  57        GIT_COLOR_BG_RED,       /* WHITESPACE */
  58        GIT_COLOR_NORMAL,       /* FUNCINFO */
  59};
  60
  61static NORETURN void die_want_option(const char *option_name)
  62{
  63        die(_("option '%s' requires a value"), option_name);
  64}
  65
  66static int parse_diff_color_slot(const char *var)
  67{
  68        if (!strcasecmp(var, "context") || !strcasecmp(var, "plain"))
  69                return DIFF_CONTEXT;
  70        if (!strcasecmp(var, "meta"))
  71                return DIFF_METAINFO;
  72        if (!strcasecmp(var, "frag"))
  73                return DIFF_FRAGINFO;
  74        if (!strcasecmp(var, "old"))
  75                return DIFF_FILE_OLD;
  76        if (!strcasecmp(var, "new"))
  77                return DIFF_FILE_NEW;
  78        if (!strcasecmp(var, "commit"))
  79                return DIFF_COMMIT;
  80        if (!strcasecmp(var, "whitespace"))
  81                return DIFF_WHITESPACE;
  82        if (!strcasecmp(var, "func"))
  83                return DIFF_FUNCINFO;
  84        return -1;
  85}
  86
  87static int parse_dirstat_params(struct diff_options *options, const char *params_string,
  88                                struct strbuf *errmsg)
  89{
  90        char *params_copy = xstrdup(params_string);
  91        struct string_list params = STRING_LIST_INIT_NODUP;
  92        int ret = 0;
  93        int i;
  94
  95        if (*params_copy)
  96                string_list_split_in_place(&params, params_copy, ',', -1);
  97        for (i = 0; i < params.nr; i++) {
  98                const char *p = params.items[i].string;
  99                if (!strcmp(p, "changes")) {
 100                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
 101                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
 102                } else if (!strcmp(p, "lines")) {
 103                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
 104                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
 105                } else if (!strcmp(p, "files")) {
 106                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
 107                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
 108                } else if (!strcmp(p, "noncumulative")) {
 109                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
 110                } else if (!strcmp(p, "cumulative")) {
 111                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
 112                } else if (isdigit(*p)) {
 113                        char *end;
 114                        int permille = strtoul(p, &end, 10) * 10;
 115                        if (*end == '.' && isdigit(*++end)) {
 116                                /* only use first digit */
 117                                permille += *end - '0';
 118                                /* .. and ignore any further digits */
 119                                while (isdigit(*++end))
 120                                        ; /* nothing */
 121                        }
 122                        if (!*end)
 123                                options->dirstat_permille = permille;
 124                        else {
 125                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 126                                            p);
 127                                ret++;
 128                        }
 129                } else {
 130                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 131                        ret++;
 132                }
 133
 134        }
 135        string_list_clear(&params, 0);
 136        free(params_copy);
 137        return ret;
 138}
 139
 140static int parse_submodule_params(struct diff_options *options, const char *value)
 141{
 142        if (!strcmp(value, "log"))
 143                options->submodule_format = DIFF_SUBMODULE_LOG;
 144        else if (!strcmp(value, "short"))
 145                options->submodule_format = DIFF_SUBMODULE_SHORT;
 146        else if (!strcmp(value, "diff"))
 147                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 148        else
 149                return -1;
 150        return 0;
 151}
 152
 153static int git_config_rename(const char *var, const char *value)
 154{
 155        if (!value)
 156                return DIFF_DETECT_RENAME;
 157        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 158                return  DIFF_DETECT_COPY;
 159        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 160}
 161
 162long parse_algorithm_value(const char *value)
 163{
 164        if (!value)
 165                return -1;
 166        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 167                return 0;
 168        else if (!strcasecmp(value, "minimal"))
 169                return XDF_NEED_MINIMAL;
 170        else if (!strcasecmp(value, "patience"))
 171                return XDF_PATIENCE_DIFF;
 172        else if (!strcasecmp(value, "histogram"))
 173                return XDF_HISTOGRAM_DIFF;
 174        return -1;
 175}
 176
 177static int parse_one_token(const char **arg, const char *token)
 178{
 179        const char *rest;
 180        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 181                *arg = rest;
 182                return 1;
 183        }
 184        return 0;
 185}
 186
 187static int parse_ws_error_highlight(const char *arg)
 188{
 189        const char *orig_arg = arg;
 190        unsigned val = 0;
 191
 192        while (*arg) {
 193                if (parse_one_token(&arg, "none"))
 194                        val = 0;
 195                else if (parse_one_token(&arg, "default"))
 196                        val = WSEH_NEW;
 197                else if (parse_one_token(&arg, "all"))
 198                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 199                else if (parse_one_token(&arg, "new"))
 200                        val |= WSEH_NEW;
 201                else if (parse_one_token(&arg, "old"))
 202                        val |= WSEH_OLD;
 203                else if (parse_one_token(&arg, "context"))
 204                        val |= WSEH_CONTEXT;
 205                else {
 206                        return -1 - (int)(arg - orig_arg);
 207                }
 208                if (*arg)
 209                        arg++;
 210        }
 211        return val;
 212}
 213
 214/*
 215 * These are to give UI layer defaults.
 216 * The core-level commands such as git-diff-files should
 217 * never be affected by the setting of diff.renames
 218 * the user happens to have in the configuration file.
 219 */
 220void init_diff_ui_defaults(void)
 221{
 222        diff_detect_rename_default = 1;
 223}
 224
 225int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 226{
 227        if (!strcmp(var, "diff.indentheuristic"))
 228                diff_indent_heuristic = git_config_bool(var, value);
 229        return 0;
 230}
 231
 232int git_diff_ui_config(const char *var, const char *value, void *cb)
 233{
 234        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 235                diff_use_color_default = git_config_colorbool(var, value);
 236                return 0;
 237        }
 238        if (!strcmp(var, "diff.context")) {
 239                diff_context_default = git_config_int(var, value);
 240                if (diff_context_default < 0)
 241                        return -1;
 242                return 0;
 243        }
 244        if (!strcmp(var, "diff.interhunkcontext")) {
 245                diff_interhunk_context_default = git_config_int(var, value);
 246                if (diff_interhunk_context_default < 0)
 247                        return -1;
 248                return 0;
 249        }
 250        if (!strcmp(var, "diff.renames")) {
 251                diff_detect_rename_default = git_config_rename(var, value);
 252                return 0;
 253        }
 254        if (!strcmp(var, "diff.autorefreshindex")) {
 255                diff_auto_refresh_index = git_config_bool(var, value);
 256                return 0;
 257        }
 258        if (!strcmp(var, "diff.mnemonicprefix")) {
 259                diff_mnemonic_prefix = git_config_bool(var, value);
 260                return 0;
 261        }
 262        if (!strcmp(var, "diff.noprefix")) {
 263                diff_no_prefix = git_config_bool(var, value);
 264                return 0;
 265        }
 266        if (!strcmp(var, "diff.statgraphwidth")) {
 267                diff_stat_graph_width = git_config_int(var, value);
 268                return 0;
 269        }
 270        if (!strcmp(var, "diff.external"))
 271                return git_config_string(&external_diff_cmd_cfg, var, value);
 272        if (!strcmp(var, "diff.wordregex"))
 273                return git_config_string(&diff_word_regex_cfg, var, value);
 274        if (!strcmp(var, "diff.orderfile"))
 275                return git_config_pathname(&diff_order_file_cfg, var, value);
 276
 277        if (!strcmp(var, "diff.ignoresubmodules"))
 278                handle_ignore_submodules_arg(&default_diff_options, value);
 279
 280        if (!strcmp(var, "diff.submodule")) {
 281                if (parse_submodule_params(&default_diff_options, value))
 282                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 283                                value);
 284                return 0;
 285        }
 286
 287        if (!strcmp(var, "diff.algorithm")) {
 288                diff_algorithm = parse_algorithm_value(value);
 289                if (diff_algorithm < 0)
 290                        return -1;
 291                return 0;
 292        }
 293
 294        if (!strcmp(var, "diff.wserrorhighlight")) {
 295                int val = parse_ws_error_highlight(value);
 296                if (val < 0)
 297                        return -1;
 298                ws_error_highlight_default = val;
 299                return 0;
 300        }
 301
 302        if (git_color_config(var, value, cb) < 0)
 303                return -1;
 304
 305        return git_diff_basic_config(var, value, cb);
 306}
 307
 308int git_diff_basic_config(const char *var, const char *value, void *cb)
 309{
 310        const char *name;
 311
 312        if (!strcmp(var, "diff.renamelimit")) {
 313                diff_rename_limit_default = git_config_int(var, value);
 314                return 0;
 315        }
 316
 317        if (userdiff_config(var, value) < 0)
 318                return -1;
 319
 320        if (skip_prefix(var, "diff.color.", &name) ||
 321            skip_prefix(var, "color.diff.", &name)) {
 322                int slot = parse_diff_color_slot(name);
 323                if (slot < 0)
 324                        return 0;
 325                if (!value)
 326                        return config_error_nonbool(var);
 327                return color_parse(value, diff_colors[slot]);
 328        }
 329
 330        /* like GNU diff's --suppress-blank-empty option  */
 331        if (!strcmp(var, "diff.suppressblankempty") ||
 332                        /* for backwards compatibility */
 333                        !strcmp(var, "diff.suppress-blank-empty")) {
 334                diff_suppress_blank_empty = git_config_bool(var, value);
 335                return 0;
 336        }
 337
 338        if (!strcmp(var, "diff.dirstat")) {
 339                struct strbuf errmsg = STRBUF_INIT;
 340                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 341                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 342                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 343                                errmsg.buf);
 344                strbuf_release(&errmsg);
 345                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 346                return 0;
 347        }
 348
 349        if (starts_with(var, "submodule."))
 350                return parse_submodule_config_option(var, value);
 351
 352        if (git_diff_heuristic_config(var, value, cb) < 0)
 353                return -1;
 354
 355        return git_default_config(var, value, cb);
 356}
 357
 358static char *quote_two(const char *one, const char *two)
 359{
 360        int need_one = quote_c_style(one, NULL, NULL, 1);
 361        int need_two = quote_c_style(two, NULL, NULL, 1);
 362        struct strbuf res = STRBUF_INIT;
 363
 364        if (need_one + need_two) {
 365                strbuf_addch(&res, '"');
 366                quote_c_style(one, &res, NULL, 1);
 367                quote_c_style(two, &res, NULL, 1);
 368                strbuf_addch(&res, '"');
 369        } else {
 370                strbuf_addstr(&res, one);
 371                strbuf_addstr(&res, two);
 372        }
 373        return strbuf_detach(&res, NULL);
 374}
 375
 376static const char *external_diff(void)
 377{
 378        static const char *external_diff_cmd = NULL;
 379        static int done_preparing = 0;
 380
 381        if (done_preparing)
 382                return external_diff_cmd;
 383        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 384        if (!external_diff_cmd)
 385                external_diff_cmd = external_diff_cmd_cfg;
 386        done_preparing = 1;
 387        return external_diff_cmd;
 388}
 389
 390/*
 391 * Keep track of files used for diffing. Sometimes such an entry
 392 * refers to a temporary file, sometimes to an existing file, and
 393 * sometimes to "/dev/null".
 394 */
 395static struct diff_tempfile {
 396        /*
 397         * filename external diff should read from, or NULL if this
 398         * entry is currently not in use:
 399         */
 400        const char *name;
 401
 402        char hex[GIT_MAX_HEXSZ + 1];
 403        char mode[10];
 404
 405        /*
 406         * If this diff_tempfile instance refers to a temporary file,
 407         * this tempfile object is used to manage its lifetime.
 408         */
 409        struct tempfile tempfile;
 410} diff_temp[2];
 411
 412typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 413
 414struct emit_callback {
 415        int color_diff;
 416        unsigned ws_rule;
 417        int blank_at_eof_in_preimage;
 418        int blank_at_eof_in_postimage;
 419        int lno_in_preimage;
 420        int lno_in_postimage;
 421        sane_truncate_fn truncate;
 422        const char **label_path;
 423        struct diff_words_data *diff_words;
 424        struct diff_options *opt;
 425        struct strbuf *header;
 426};
 427
 428static int count_lines(const char *data, int size)
 429{
 430        int count, ch, completely_empty = 1, nl_just_seen = 0;
 431        count = 0;
 432        while (0 < size--) {
 433                ch = *data++;
 434                if (ch == '\n') {
 435                        count++;
 436                        nl_just_seen = 1;
 437                        completely_empty = 0;
 438                }
 439                else {
 440                        nl_just_seen = 0;
 441                        completely_empty = 0;
 442                }
 443        }
 444        if (completely_empty)
 445                return 0;
 446        if (!nl_just_seen)
 447                count++; /* no trailing newline */
 448        return count;
 449}
 450
 451static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 452{
 453        if (!DIFF_FILE_VALID(one)) {
 454                mf->ptr = (char *)""; /* does not matter */
 455                mf->size = 0;
 456                return 0;
 457        }
 458        else if (diff_populate_filespec(one, 0))
 459                return -1;
 460
 461        mf->ptr = one->data;
 462        mf->size = one->size;
 463        return 0;
 464}
 465
 466/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 467static unsigned long diff_filespec_size(struct diff_filespec *one)
 468{
 469        if (!DIFF_FILE_VALID(one))
 470                return 0;
 471        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 472        return one->size;
 473}
 474
 475static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 476{
 477        char *ptr = mf->ptr;
 478        long size = mf->size;
 479        int cnt = 0;
 480
 481        if (!size)
 482                return cnt;
 483        ptr += size - 1; /* pointing at the very end */
 484        if (*ptr != '\n')
 485                ; /* incomplete line */
 486        else
 487                ptr--; /* skip the last LF */
 488        while (mf->ptr < ptr) {
 489                char *prev_eol;
 490                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 491                        if (*prev_eol == '\n')
 492                                break;
 493                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 494                        break;
 495                cnt++;
 496                ptr = prev_eol - 1;
 497        }
 498        return cnt;
 499}
 500
 501static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 502                               struct emit_callback *ecbdata)
 503{
 504        int l1, l2, at;
 505        unsigned ws_rule = ecbdata->ws_rule;
 506        l1 = count_trailing_blank(mf1, ws_rule);
 507        l2 = count_trailing_blank(mf2, ws_rule);
 508        if (l2 <= l1) {
 509                ecbdata->blank_at_eof_in_preimage = 0;
 510                ecbdata->blank_at_eof_in_postimage = 0;
 511                return;
 512        }
 513        at = count_lines(mf1->ptr, mf1->size);
 514        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 515
 516        at = count_lines(mf2->ptr, mf2->size);
 517        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 518}
 519
 520static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 521                        int first, const char *line, int len)
 522{
 523        int has_trailing_newline, has_trailing_carriage_return;
 524        int nofirst;
 525        FILE *file = o->file;
 526
 527        fputs(diff_line_prefix(o), file);
 528
 529        if (len == 0) {
 530                has_trailing_newline = (first == '\n');
 531                has_trailing_carriage_return = (!has_trailing_newline &&
 532                                                (first == '\r'));
 533                nofirst = has_trailing_newline || has_trailing_carriage_return;
 534        } else {
 535                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 536                if (has_trailing_newline)
 537                        len--;
 538                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 539                if (has_trailing_carriage_return)
 540                        len--;
 541                nofirst = 0;
 542        }
 543
 544        if (len || !nofirst) {
 545                fputs(set, file);
 546                if (!nofirst)
 547                        fputc(first, file);
 548                fwrite(line, len, 1, file);
 549                fputs(reset, file);
 550        }
 551        if (has_trailing_carriage_return)
 552                fputc('\r', file);
 553        if (has_trailing_newline)
 554                fputc('\n', file);
 555}
 556
 557static void emit_line(struct diff_options *o, const char *set, const char *reset,
 558                      const char *line, int len)
 559{
 560        emit_line_0(o, set, reset, line[0], line+1, len-1);
 561}
 562
 563enum diff_symbol {
 564        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 565        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 566        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 567        DIFF_SYMBOL_BINARY_DIFF_BODY,
 568        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 569        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 570        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 571        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 572        DIFF_SYMBOL_STATS_LINE,
 573        DIFF_SYMBOL_WORD_DIFF,
 574        DIFF_SYMBOL_SUBMODULE_ADD,
 575        DIFF_SYMBOL_SUBMODULE_DEL,
 576        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 577        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 578        DIFF_SYMBOL_SUBMODULE_HEADER,
 579        DIFF_SYMBOL_SUBMODULE_ERROR,
 580        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 581        DIFF_SYMBOL_REWRITE_DIFF,
 582        DIFF_SYMBOL_BINARY_FILES,
 583        DIFF_SYMBOL_HEADER,
 584        DIFF_SYMBOL_FILEPAIR_PLUS,
 585        DIFF_SYMBOL_FILEPAIR_MINUS,
 586        DIFF_SYMBOL_WORDS_PORCELAIN,
 587        DIFF_SYMBOL_WORDS,
 588        DIFF_SYMBOL_CONTEXT,
 589        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 590        DIFF_SYMBOL_PLUS,
 591        DIFF_SYMBOL_MINUS,
 592        DIFF_SYMBOL_NO_LF_EOF,
 593        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 594        DIFF_SYMBOL_CONTEXT_MARKER,
 595        DIFF_SYMBOL_SEPARATOR
 596};
 597/*
 598 * Flags for content lines:
 599 * 0..12 are whitespace rules
 600 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 601 * 16 is marking if the line is blank at EOF
 602 */
 603#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF (1<<16)
 604#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 605
 606static void emit_line_ws_markup(struct diff_options *o,
 607                                const char *set, const char *reset,
 608                                const char *line, int len, char sign,
 609                                unsigned ws_rule, int blank_at_eof)
 610{
 611        const char *ws = NULL;
 612
 613        if (o->ws_error_highlight & ws_rule) {
 614                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
 615                if (!*ws)
 616                        ws = NULL;
 617        }
 618
 619        if (!ws)
 620                emit_line_0(o, set, reset, sign, line, len);
 621        else if (blank_at_eof)
 622                /* Blank line at EOF - paint '+' as well */
 623                emit_line_0(o, ws, reset, sign, line, len);
 624        else {
 625                /* Emit just the prefix, then the rest. */
 626                emit_line_0(o, set, reset, sign, "", 0);
 627                ws_check_emit(line, len, ws_rule,
 628                              o->file, set, reset, ws);
 629        }
 630}
 631
 632static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
 633                             const char *line, int len, unsigned flags)
 634{
 635        static const char *nneof = " No newline at end of file\n";
 636        const char *context, *reset, *set, *meta, *fraginfo;
 637        struct strbuf sb = STRBUF_INIT;
 638        switch (s) {
 639        case DIFF_SYMBOL_NO_LF_EOF:
 640                context = diff_get_color_opt(o, DIFF_CONTEXT);
 641                reset = diff_get_color_opt(o, DIFF_RESET);
 642                putc('\n', o->file);
 643                emit_line_0(o, context, reset, '\\',
 644                            nneof, strlen(nneof));
 645                break;
 646        case DIFF_SYMBOL_SUBMODULE_HEADER:
 647        case DIFF_SYMBOL_SUBMODULE_ERROR:
 648        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
 649        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
 650        case DIFF_SYMBOL_STATS_LINE:
 651        case DIFF_SYMBOL_BINARY_DIFF_BODY:
 652        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
 653                emit_line(o, "", "", line, len);
 654                break;
 655        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
 656        case DIFF_SYMBOL_CONTEXT_MARKER:
 657                context = diff_get_color_opt(o, DIFF_CONTEXT);
 658                reset = diff_get_color_opt(o, DIFF_RESET);
 659                emit_line(o, context, reset, line, len);
 660                break;
 661        case DIFF_SYMBOL_SEPARATOR:
 662                fprintf(o->file, "%s%c",
 663                        diff_line_prefix(o),
 664                        o->line_termination);
 665                break;
 666        case DIFF_SYMBOL_CONTEXT:
 667                set = diff_get_color_opt(o, DIFF_CONTEXT);
 668                reset = diff_get_color_opt(o, DIFF_RESET);
 669                emit_line_ws_markup(o, set, reset, line, len, ' ',
 670                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
 671                break;
 672        case DIFF_SYMBOL_PLUS:
 673                set = diff_get_color_opt(o, DIFF_FILE_NEW);
 674                reset = diff_get_color_opt(o, DIFF_RESET);
 675                emit_line_ws_markup(o, set, reset, line, len, '+',
 676                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
 677                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
 678                break;
 679        case DIFF_SYMBOL_MINUS:
 680                set = diff_get_color_opt(o, DIFF_FILE_OLD);
 681                reset = diff_get_color_opt(o, DIFF_RESET);
 682                emit_line_ws_markup(o, set, reset, line, len, '-',
 683                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
 684                break;
 685        case DIFF_SYMBOL_WORDS_PORCELAIN:
 686                context = diff_get_color_opt(o, DIFF_CONTEXT);
 687                reset = diff_get_color_opt(o, DIFF_RESET);
 688                emit_line(o, context, reset, line, len);
 689                fputs("~\n", o->file);
 690                break;
 691        case DIFF_SYMBOL_WORDS:
 692                context = diff_get_color_opt(o, DIFF_CONTEXT);
 693                reset = diff_get_color_opt(o, DIFF_RESET);
 694                /*
 695                 * Skip the prefix character, if any.  With
 696                 * diff_suppress_blank_empty, there may be
 697                 * none.
 698                 */
 699                if (line[0] != '\n') {
 700                        line++;
 701                        len--;
 702                }
 703                emit_line(o, context, reset, line, len);
 704                break;
 705        case DIFF_SYMBOL_FILEPAIR_PLUS:
 706                meta = diff_get_color_opt(o, DIFF_METAINFO);
 707                reset = diff_get_color_opt(o, DIFF_RESET);
 708                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
 709                        line, reset,
 710                        strchr(line, ' ') ? "\t" : "");
 711                break;
 712        case DIFF_SYMBOL_FILEPAIR_MINUS:
 713                meta = diff_get_color_opt(o, DIFF_METAINFO);
 714                reset = diff_get_color_opt(o, DIFF_RESET);
 715                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
 716                        line, reset,
 717                        strchr(line, ' ') ? "\t" : "");
 718                break;
 719        case DIFF_SYMBOL_BINARY_FILES:
 720        case DIFF_SYMBOL_HEADER:
 721                fprintf(o->file, "%s", line);
 722                break;
 723        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
 724                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
 725                break;
 726        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
 727                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
 728                break;
 729        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
 730                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
 731                break;
 732        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
 733                fputs(diff_line_prefix(o), o->file);
 734                fputc('\n', o->file);
 735                break;
 736        case DIFF_SYMBOL_REWRITE_DIFF:
 737                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 738                reset = diff_get_color_opt(o, DIFF_RESET);
 739                emit_line(o, fraginfo, reset, line, len);
 740                break;
 741        case DIFF_SYMBOL_SUBMODULE_ADD:
 742                set = diff_get_color_opt(o, DIFF_FILE_NEW);
 743                reset = diff_get_color_opt(o, DIFF_RESET);
 744                emit_line(o, set, reset, line, len);
 745                break;
 746        case DIFF_SYMBOL_SUBMODULE_DEL:
 747                set = diff_get_color_opt(o, DIFF_FILE_OLD);
 748                reset = diff_get_color_opt(o, DIFF_RESET);
 749                emit_line(o, set, reset, line, len);
 750                break;
 751        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
 752                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
 753                        diff_line_prefix(o), line);
 754                break;
 755        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
 756                fprintf(o->file, "%sSubmodule %s contains modified content\n",
 757                        diff_line_prefix(o), line);
 758                break;
 759        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
 760                emit_line(o, "", "", " 0 files changed\n",
 761                          strlen(" 0 files changed\n"));
 762                break;
 763        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
 764                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
 765                break;
 766        case DIFF_SYMBOL_WORD_DIFF:
 767                fprintf(o->file, "%.*s", len, line);
 768                break;
 769        default:
 770                die("BUG: unknown diff symbol");
 771        }
 772        strbuf_release(&sb);
 773}
 774
 775void diff_emit_submodule_del(struct diff_options *o, const char *line)
 776{
 777        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
 778}
 779
 780void diff_emit_submodule_add(struct diff_options *o, const char *line)
 781{
 782        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
 783}
 784
 785void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
 786{
 787        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 788                         path, strlen(path), 0);
 789}
 790
 791void diff_emit_submodule_modified(struct diff_options *o, const char *path)
 792{
 793        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
 794                         path, strlen(path), 0);
 795}
 796
 797void diff_emit_submodule_header(struct diff_options *o, const char *header)
 798{
 799        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
 800                         header, strlen(header), 0);
 801}
 802
 803void diff_emit_submodule_error(struct diff_options *o, const char *err)
 804{
 805        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
 806}
 807
 808void diff_emit_submodule_pipethrough(struct diff_options *o,
 809                                     const char *line, int len)
 810{
 811        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
 812}
 813
 814static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 815{
 816        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 817              ecbdata->blank_at_eof_in_preimage &&
 818              ecbdata->blank_at_eof_in_postimage &&
 819              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 820              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 821                return 0;
 822        return ws_blank_line(line, len, ecbdata->ws_rule);
 823}
 824
 825static void emit_add_line(const char *reset,
 826                          struct emit_callback *ecbdata,
 827                          const char *line, int len)
 828{
 829        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
 830        if (new_blank_line_at_eof(ecbdata, line, len))
 831                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
 832
 833        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
 834}
 835
 836static void emit_del_line(const char *reset,
 837                          struct emit_callback *ecbdata,
 838                          const char *line, int len)
 839{
 840        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
 841        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
 842}
 843
 844static void emit_context_line(const char *reset,
 845                              struct emit_callback *ecbdata,
 846                              const char *line, int len)
 847{
 848        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
 849        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
 850}
 851
 852static void emit_hunk_header(struct emit_callback *ecbdata,
 853                             const char *line, int len)
 854{
 855        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
 856        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 857        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 858        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 859        static const char atat[2] = { '@', '@' };
 860        const char *cp, *ep;
 861        struct strbuf msgbuf = STRBUF_INIT;
 862        int org_len = len;
 863        int i = 1;
 864
 865        /*
 866         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 867         * it always is at least 10 bytes long.
 868         */
 869        if (len < 10 ||
 870            memcmp(line, atat, 2) ||
 871            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 872                emit_diff_symbol(ecbdata->opt,
 873                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
 874                return;
 875        }
 876        ep += 2; /* skip over @@ */
 877
 878        /* The hunk header in fraginfo color */
 879        strbuf_addstr(&msgbuf, frag);
 880        strbuf_add(&msgbuf, line, ep - line);
 881        strbuf_addstr(&msgbuf, reset);
 882
 883        /*
 884         * trailing "\r\n"
 885         */
 886        for ( ; i < 3; i++)
 887                if (line[len - i] == '\r' || line[len - i] == '\n')
 888                        len--;
 889
 890        /* blank before the func header */
 891        for (cp = ep; ep - line < len; ep++)
 892                if (*ep != ' ' && *ep != '\t')
 893                        break;
 894        if (ep != cp) {
 895                strbuf_addstr(&msgbuf, context);
 896                strbuf_add(&msgbuf, cp, ep - cp);
 897                strbuf_addstr(&msgbuf, reset);
 898        }
 899
 900        if (ep < line + len) {
 901                strbuf_addstr(&msgbuf, func);
 902                strbuf_add(&msgbuf, ep, line + len - ep);
 903                strbuf_addstr(&msgbuf, reset);
 904        }
 905
 906        strbuf_add(&msgbuf, line + len, org_len - len);
 907        strbuf_complete_line(&msgbuf);
 908        emit_diff_symbol(ecbdata->opt,
 909                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
 910        strbuf_release(&msgbuf);
 911}
 912
 913static struct diff_tempfile *claim_diff_tempfile(void) {
 914        int i;
 915        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 916                if (!diff_temp[i].name)
 917                        return diff_temp + i;
 918        die("BUG: diff is failing to clean up its tempfiles");
 919}
 920
 921static void remove_tempfile(void)
 922{
 923        int i;
 924        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 925                if (is_tempfile_active(&diff_temp[i].tempfile))
 926                        delete_tempfile(&diff_temp[i].tempfile);
 927                diff_temp[i].name = NULL;
 928        }
 929}
 930
 931static void add_line_count(struct strbuf *out, int count)
 932{
 933        switch (count) {
 934        case 0:
 935                strbuf_addstr(out, "0,0");
 936                break;
 937        case 1:
 938                strbuf_addstr(out, "1");
 939                break;
 940        default:
 941                strbuf_addf(out, "1,%d", count);
 942                break;
 943        }
 944}
 945
 946static void emit_rewrite_lines(struct emit_callback *ecb,
 947                               int prefix, const char *data, int size)
 948{
 949        const char *endp = NULL;
 950        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 951
 952        while (0 < size) {
 953                int len;
 954
 955                endp = memchr(data, '\n', size);
 956                len = endp ? (endp - data + 1) : size;
 957                if (prefix != '+') {
 958                        ecb->lno_in_preimage++;
 959                        emit_del_line(reset, ecb, data, len);
 960                } else {
 961                        ecb->lno_in_postimage++;
 962                        emit_add_line(reset, ecb, data, len);
 963                }
 964                size -= len;
 965                data += len;
 966        }
 967        if (!endp)
 968                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
 969}
 970
 971static void emit_rewrite_diff(const char *name_a,
 972                              const char *name_b,
 973                              struct diff_filespec *one,
 974                              struct diff_filespec *two,
 975                              struct userdiff_driver *textconv_one,
 976                              struct userdiff_driver *textconv_two,
 977                              struct diff_options *o)
 978{
 979        int lc_a, lc_b;
 980        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 981        const char *a_prefix, *b_prefix;
 982        char *data_one, *data_two;
 983        size_t size_one, size_two;
 984        struct emit_callback ecbdata;
 985        struct strbuf out = STRBUF_INIT;
 986
 987        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 988                a_prefix = o->b_prefix;
 989                b_prefix = o->a_prefix;
 990        } else {
 991                a_prefix = o->a_prefix;
 992                b_prefix = o->b_prefix;
 993        }
 994
 995        name_a += (*name_a == '/');
 996        name_b += (*name_b == '/');
 997
 998        strbuf_reset(&a_name);
 999        strbuf_reset(&b_name);
1000        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1001        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1002
1003        size_one = fill_textconv(textconv_one, one, &data_one);
1004        size_two = fill_textconv(textconv_two, two, &data_two);
1005
1006        memset(&ecbdata, 0, sizeof(ecbdata));
1007        ecbdata.color_diff = want_color(o->use_color);
1008        ecbdata.ws_rule = whitespace_rule(name_b);
1009        ecbdata.opt = o;
1010        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1011                mmfile_t mf1, mf2;
1012                mf1.ptr = (char *)data_one;
1013                mf2.ptr = (char *)data_two;
1014                mf1.size = size_one;
1015                mf2.size = size_two;
1016                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1017        }
1018        ecbdata.lno_in_preimage = 1;
1019        ecbdata.lno_in_postimage = 1;
1020
1021        lc_a = count_lines(data_one, size_one);
1022        lc_b = count_lines(data_two, size_two);
1023
1024        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1025                         a_name.buf, a_name.len, 0);
1026        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1027                         b_name.buf, b_name.len, 0);
1028
1029        strbuf_addstr(&out, "@@ -");
1030        if (!o->irreversible_delete)
1031                add_line_count(&out, lc_a);
1032        else
1033                strbuf_addstr(&out, "?,?");
1034        strbuf_addstr(&out, " +");
1035        add_line_count(&out, lc_b);
1036        strbuf_addstr(&out, " @@\n");
1037        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1038        strbuf_release(&out);
1039
1040        if (lc_a && !o->irreversible_delete)
1041                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1042        if (lc_b)
1043                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1044        if (textconv_one)
1045                free((char *)data_one);
1046        if (textconv_two)
1047                free((char *)data_two);
1048}
1049
1050struct diff_words_buffer {
1051        mmfile_t text;
1052        long alloc;
1053        struct diff_words_orig {
1054                const char *begin, *end;
1055        } *orig;
1056        int orig_nr, orig_alloc;
1057};
1058
1059static void diff_words_append(char *line, unsigned long len,
1060                struct diff_words_buffer *buffer)
1061{
1062        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1063        line++;
1064        len--;
1065        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1066        buffer->text.size += len;
1067        buffer->text.ptr[buffer->text.size] = '\0';
1068}
1069
1070struct diff_words_style_elem {
1071        const char *prefix;
1072        const char *suffix;
1073        const char *color; /* NULL; filled in by the setup code if
1074                            * color is enabled */
1075};
1076
1077struct diff_words_style {
1078        enum diff_words_type type;
1079        struct diff_words_style_elem new, old, ctx;
1080        const char *newline;
1081};
1082
1083static struct diff_words_style diff_words_styles[] = {
1084        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1085        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1086        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1087};
1088
1089struct diff_words_data {
1090        struct diff_words_buffer minus, plus;
1091        const char *current_plus;
1092        int last_minus;
1093        struct diff_options *opt;
1094        regex_t *word_regex;
1095        enum diff_words_type type;
1096        struct diff_words_style *style;
1097};
1098
1099static int fn_out_diff_words_write_helper(struct diff_options *o,
1100                                          struct diff_words_style_elem *st_el,
1101                                          const char *newline,
1102                                          size_t count, const char *buf)
1103{
1104        int print = 0;
1105        struct strbuf sb = STRBUF_INIT;
1106
1107        while (count) {
1108                char *p = memchr(buf, '\n', count);
1109                if (print)
1110                        strbuf_addstr(&sb, diff_line_prefix(o));
1111
1112                if (p != buf) {
1113                        const char *reset = st_el->color && *st_el->color ?
1114                                            GIT_COLOR_RESET : NULL;
1115                        if (st_el->color && *st_el->color)
1116                                strbuf_addstr(&sb, st_el->color);
1117                        strbuf_addstr(&sb, st_el->prefix);
1118                        strbuf_add(&sb, buf, p ? p - buf : count);
1119                        strbuf_addstr(&sb, st_el->suffix);
1120                        if (reset)
1121                                strbuf_addstr(&sb, reset);
1122                }
1123                if (!p)
1124                        goto out;
1125
1126                strbuf_addstr(&sb, newline);
1127                count -= p + 1 - buf;
1128                buf = p + 1;
1129                print = 1;
1130                if (count) {
1131                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1132                                         sb.buf, sb.len, 0);
1133                        strbuf_reset(&sb);
1134                }
1135        }
1136
1137out:
1138        if (sb.len)
1139                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1140                                 sb.buf, sb.len, 0);
1141        strbuf_release(&sb);
1142        return 0;
1143}
1144
1145/*
1146 * '--color-words' algorithm can be described as:
1147 *
1148 *   1. collect the minus/plus lines of a diff hunk, divided into
1149 *      minus-lines and plus-lines;
1150 *
1151 *   2. break both minus-lines and plus-lines into words and
1152 *      place them into two mmfile_t with one word for each line;
1153 *
1154 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1155 *
1156 * And for the common parts of the both file, we output the plus side text.
1157 * diff_words->current_plus is used to trace the current position of the plus file
1158 * which printed. diff_words->last_minus is used to trace the last minus word
1159 * printed.
1160 *
1161 * For '--graph' to work with '--color-words', we need to output the graph prefix
1162 * on each line of color words output. Generally, there are two conditions on
1163 * which we should output the prefix.
1164 *
1165 *   1. diff_words->last_minus == 0 &&
1166 *      diff_words->current_plus == diff_words->plus.text.ptr
1167 *
1168 *      that is: the plus text must start as a new line, and if there is no minus
1169 *      word printed, a graph prefix must be printed.
1170 *
1171 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1172 *      *(diff_words->current_plus - 1) == '\n'
1173 *
1174 *      that is: a graph prefix must be printed following a '\n'
1175 */
1176static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1177{
1178        if ((diff_words->last_minus == 0 &&
1179                diff_words->current_plus == diff_words->plus.text.ptr) ||
1180                (diff_words->current_plus > diff_words->plus.text.ptr &&
1181                *(diff_words->current_plus - 1) == '\n')) {
1182                return 1;
1183        } else {
1184                return 0;
1185        }
1186}
1187
1188static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1189{
1190        struct diff_words_data *diff_words = priv;
1191        struct diff_words_style *style = diff_words->style;
1192        int minus_first, minus_len, plus_first, plus_len;
1193        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1194        struct diff_options *opt = diff_words->opt;
1195        const char *line_prefix;
1196
1197        if (line[0] != '@' || parse_hunk_header(line, len,
1198                        &minus_first, &minus_len, &plus_first, &plus_len))
1199                return;
1200
1201        assert(opt);
1202        line_prefix = diff_line_prefix(opt);
1203
1204        /* POSIX requires that first be decremented by one if len == 0... */
1205        if (minus_len) {
1206                minus_begin = diff_words->minus.orig[minus_first].begin;
1207                minus_end =
1208                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1209        } else
1210                minus_begin = minus_end =
1211                        diff_words->minus.orig[minus_first].end;
1212
1213        if (plus_len) {
1214                plus_begin = diff_words->plus.orig[plus_first].begin;
1215                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1216        } else
1217                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1218
1219        if (color_words_output_graph_prefix(diff_words)) {
1220                fputs(line_prefix, diff_words->opt->file);
1221        }
1222        if (diff_words->current_plus != plus_begin) {
1223                fn_out_diff_words_write_helper(diff_words->opt,
1224                                &style->ctx, style->newline,
1225                                plus_begin - diff_words->current_plus,
1226                                diff_words->current_plus);
1227        }
1228        if (minus_begin != minus_end) {
1229                fn_out_diff_words_write_helper(diff_words->opt,
1230                                &style->old, style->newline,
1231                                minus_end - minus_begin, minus_begin);
1232        }
1233        if (plus_begin != plus_end) {
1234                fn_out_diff_words_write_helper(diff_words->opt,
1235                                &style->new, style->newline,
1236                                plus_end - plus_begin, plus_begin);
1237        }
1238
1239        diff_words->current_plus = plus_end;
1240        diff_words->last_minus = minus_first;
1241}
1242
1243/* This function starts looking at *begin, and returns 0 iff a word was found. */
1244static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1245                int *begin, int *end)
1246{
1247        if (word_regex && *begin < buffer->size) {
1248                regmatch_t match[1];
1249                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1250                                 buffer->size - *begin, 1, match, 0)) {
1251                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1252                                        '\n', match[0].rm_eo - match[0].rm_so);
1253                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1254                        *begin += match[0].rm_so;
1255                        return *begin >= *end;
1256                }
1257                return -1;
1258        }
1259
1260        /* find the next word */
1261        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1262                (*begin)++;
1263        if (*begin >= buffer->size)
1264                return -1;
1265
1266        /* find the end of the word */
1267        *end = *begin + 1;
1268        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1269                (*end)++;
1270
1271        return 0;
1272}
1273
1274/*
1275 * This function splits the words in buffer->text, stores the list with
1276 * newline separator into out, and saves the offsets of the original words
1277 * in buffer->orig.
1278 */
1279static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1280                regex_t *word_regex)
1281{
1282        int i, j;
1283        long alloc = 0;
1284
1285        out->size = 0;
1286        out->ptr = NULL;
1287
1288        /* fake an empty "0th" word */
1289        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1290        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1291        buffer->orig_nr = 1;
1292
1293        for (i = 0; i < buffer->text.size; i++) {
1294                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1295                        return;
1296
1297                /* store original boundaries */
1298                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1299                                buffer->orig_alloc);
1300                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1301                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1302                buffer->orig_nr++;
1303
1304                /* store one word */
1305                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1306                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1307                out->ptr[out->size + j - i] = '\n';
1308                out->size += j - i + 1;
1309
1310                i = j - 1;
1311        }
1312}
1313
1314/* this executes the word diff on the accumulated buffers */
1315static void diff_words_show(struct diff_words_data *diff_words)
1316{
1317        xpparam_t xpp;
1318        xdemitconf_t xecfg;
1319        mmfile_t minus, plus;
1320        struct diff_words_style *style = diff_words->style;
1321
1322        struct diff_options *opt = diff_words->opt;
1323        const char *line_prefix;
1324
1325        assert(opt);
1326        line_prefix = diff_line_prefix(opt);
1327
1328        /* special case: only removal */
1329        if (!diff_words->plus.text.size) {
1330                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1331                                 line_prefix, strlen(line_prefix), 0);
1332                fn_out_diff_words_write_helper(diff_words->opt,
1333                        &style->old, style->newline,
1334                        diff_words->minus.text.size,
1335                        diff_words->minus.text.ptr);
1336                diff_words->minus.text.size = 0;
1337                return;
1338        }
1339
1340        diff_words->current_plus = diff_words->plus.text.ptr;
1341        diff_words->last_minus = 0;
1342
1343        memset(&xpp, 0, sizeof(xpp));
1344        memset(&xecfg, 0, sizeof(xecfg));
1345        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1346        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1347        xpp.flags = 0;
1348        /* as only the hunk header will be parsed, we need a 0-context */
1349        xecfg.ctxlen = 0;
1350        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1351                          &xpp, &xecfg))
1352                die("unable to generate word diff");
1353        free(minus.ptr);
1354        free(plus.ptr);
1355        if (diff_words->current_plus != diff_words->plus.text.ptr +
1356                        diff_words->plus.text.size) {
1357                if (color_words_output_graph_prefix(diff_words))
1358                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1359                                         line_prefix, strlen(line_prefix), 0);
1360                fn_out_diff_words_write_helper(diff_words->opt,
1361                        &style->ctx, style->newline,
1362                        diff_words->plus.text.ptr + diff_words->plus.text.size
1363                        - diff_words->current_plus, diff_words->current_plus);
1364        }
1365        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1366}
1367
1368/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1369static void diff_words_flush(struct emit_callback *ecbdata)
1370{
1371        if (ecbdata->diff_words->minus.text.size ||
1372            ecbdata->diff_words->plus.text.size)
1373                diff_words_show(ecbdata->diff_words);
1374}
1375
1376static void diff_filespec_load_driver(struct diff_filespec *one)
1377{
1378        /* Use already-loaded driver */
1379        if (one->driver)
1380                return;
1381
1382        if (S_ISREG(one->mode))
1383                one->driver = userdiff_find_by_path(one->path);
1384
1385        /* Fallback to default settings */
1386        if (!one->driver)
1387                one->driver = userdiff_find_by_name("default");
1388}
1389
1390static const char *userdiff_word_regex(struct diff_filespec *one)
1391{
1392        diff_filespec_load_driver(one);
1393        return one->driver->word_regex;
1394}
1395
1396static void init_diff_words_data(struct emit_callback *ecbdata,
1397                                 struct diff_options *orig_opts,
1398                                 struct diff_filespec *one,
1399                                 struct diff_filespec *two)
1400{
1401        int i;
1402        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1403        memcpy(o, orig_opts, sizeof(struct diff_options));
1404
1405        ecbdata->diff_words =
1406                xcalloc(1, sizeof(struct diff_words_data));
1407        ecbdata->diff_words->type = o->word_diff;
1408        ecbdata->diff_words->opt = o;
1409        if (!o->word_regex)
1410                o->word_regex = userdiff_word_regex(one);
1411        if (!o->word_regex)
1412                o->word_regex = userdiff_word_regex(two);
1413        if (!o->word_regex)
1414                o->word_regex = diff_word_regex_cfg;
1415        if (o->word_regex) {
1416                ecbdata->diff_words->word_regex = (regex_t *)
1417                        xmalloc(sizeof(regex_t));
1418                if (regcomp(ecbdata->diff_words->word_regex,
1419                            o->word_regex,
1420                            REG_EXTENDED | REG_NEWLINE))
1421                        die ("Invalid regular expression: %s",
1422                             o->word_regex);
1423        }
1424        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1425                if (o->word_diff == diff_words_styles[i].type) {
1426                        ecbdata->diff_words->style =
1427                                &diff_words_styles[i];
1428                        break;
1429                }
1430        }
1431        if (want_color(o->use_color)) {
1432                struct diff_words_style *st = ecbdata->diff_words->style;
1433                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1434                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1435                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
1436        }
1437}
1438
1439static void free_diff_words_data(struct emit_callback *ecbdata)
1440{
1441        if (ecbdata->diff_words) {
1442                diff_words_flush(ecbdata);
1443                free (ecbdata->diff_words->opt);
1444                free (ecbdata->diff_words->minus.text.ptr);
1445                free (ecbdata->diff_words->minus.orig);
1446                free (ecbdata->diff_words->plus.text.ptr);
1447                free (ecbdata->diff_words->plus.orig);
1448                if (ecbdata->diff_words->word_regex) {
1449                        regfree(ecbdata->diff_words->word_regex);
1450                        free(ecbdata->diff_words->word_regex);
1451                }
1452                FREE_AND_NULL(ecbdata->diff_words);
1453        }
1454}
1455
1456const char *diff_get_color(int diff_use_color, enum color_diff ix)
1457{
1458        if (want_color(diff_use_color))
1459                return diff_colors[ix];
1460        return "";
1461}
1462
1463const char *diff_line_prefix(struct diff_options *opt)
1464{
1465        struct strbuf *msgbuf;
1466        if (!opt->output_prefix)
1467                return "";
1468
1469        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1470        return msgbuf->buf;
1471}
1472
1473static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1474{
1475        const char *cp;
1476        unsigned long allot;
1477        size_t l = len;
1478
1479        if (ecb->truncate)
1480                return ecb->truncate(line, len);
1481        cp = line;
1482        allot = l;
1483        while (0 < l) {
1484                (void) utf8_width(&cp, &l);
1485                if (!cp)
1486                        break; /* truncated in the middle? */
1487        }
1488        return allot - l;
1489}
1490
1491static void find_lno(const char *line, struct emit_callback *ecbdata)
1492{
1493        const char *p;
1494        ecbdata->lno_in_preimage = 0;
1495        ecbdata->lno_in_postimage = 0;
1496        p = strchr(line, '-');
1497        if (!p)
1498                return; /* cannot happen */
1499        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1500        p = strchr(p, '+');
1501        if (!p)
1502                return; /* cannot happen */
1503        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1504}
1505
1506static void fn_out_consume(void *priv, char *line, unsigned long len)
1507{
1508        struct emit_callback *ecbdata = priv;
1509        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1510        struct diff_options *o = ecbdata->opt;
1511
1512        o->found_changes = 1;
1513
1514        if (ecbdata->header) {
1515                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
1516                                 ecbdata->header->buf, ecbdata->header->len, 0);
1517                strbuf_reset(ecbdata->header);
1518                ecbdata->header = NULL;
1519        }
1520
1521        if (ecbdata->label_path[0]) {
1522                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1523                                 ecbdata->label_path[0],
1524                                 strlen(ecbdata->label_path[0]), 0);
1525                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1526                                 ecbdata->label_path[1],
1527                                 strlen(ecbdata->label_path[1]), 0);
1528                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1529        }
1530
1531        if (diff_suppress_blank_empty
1532            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1533                line[0] = '\n';
1534                len = 1;
1535        }
1536
1537        if (line[0] == '@') {
1538                if (ecbdata->diff_words)
1539                        diff_words_flush(ecbdata);
1540                len = sane_truncate_line(ecbdata, line, len);
1541                find_lno(line, ecbdata);
1542                emit_hunk_header(ecbdata, line, len);
1543                return;
1544        }
1545
1546        if (ecbdata->diff_words) {
1547                enum diff_symbol s =
1548                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
1549                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
1550                if (line[0] == '-') {
1551                        diff_words_append(line, len,
1552                                          &ecbdata->diff_words->minus);
1553                        return;
1554                } else if (line[0] == '+') {
1555                        diff_words_append(line, len,
1556                                          &ecbdata->diff_words->plus);
1557                        return;
1558                } else if (starts_with(line, "\\ ")) {
1559                        /*
1560                         * Eat the "no newline at eof" marker as if we
1561                         * saw a "+" or "-" line with nothing on it,
1562                         * and return without diff_words_flush() to
1563                         * defer processing. If this is the end of
1564                         * preimage, more "+" lines may come after it.
1565                         */
1566                        return;
1567                }
1568                diff_words_flush(ecbdata);
1569                emit_diff_symbol(o, s, line, len, 0);
1570                return;
1571        }
1572
1573        switch (line[0]) {
1574        case '+':
1575                ecbdata->lno_in_postimage++;
1576                emit_add_line(reset, ecbdata, line + 1, len - 1);
1577                break;
1578        case '-':
1579                ecbdata->lno_in_preimage++;
1580                emit_del_line(reset, ecbdata, line + 1, len - 1);
1581                break;
1582        case ' ':
1583                ecbdata->lno_in_postimage++;
1584                ecbdata->lno_in_preimage++;
1585                emit_context_line(reset, ecbdata, line + 1, len - 1);
1586                break;
1587        default:
1588                /* incomplete line at the end */
1589                ecbdata->lno_in_preimage++;
1590                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
1591                                 line, len, 0);
1592                break;
1593        }
1594}
1595
1596static char *pprint_rename(const char *a, const char *b)
1597{
1598        const char *old = a;
1599        const char *new = b;
1600        struct strbuf name = STRBUF_INIT;
1601        int pfx_length, sfx_length;
1602        int pfx_adjust_for_slash;
1603        int len_a = strlen(a);
1604        int len_b = strlen(b);
1605        int a_midlen, b_midlen;
1606        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1607        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1608
1609        if (qlen_a || qlen_b) {
1610                quote_c_style(a, &name, NULL, 0);
1611                strbuf_addstr(&name, " => ");
1612                quote_c_style(b, &name, NULL, 0);
1613                return strbuf_detach(&name, NULL);
1614        }
1615
1616        /* Find common prefix */
1617        pfx_length = 0;
1618        while (*old && *new && *old == *new) {
1619                if (*old == '/')
1620                        pfx_length = old - a + 1;
1621                old++;
1622                new++;
1623        }
1624
1625        /* Find common suffix */
1626        old = a + len_a;
1627        new = b + len_b;
1628        sfx_length = 0;
1629        /*
1630         * If there is a common prefix, it must end in a slash.  In
1631         * that case we let this loop run 1 into the prefix to see the
1632         * same slash.
1633         *
1634         * If there is no common prefix, we cannot do this as it would
1635         * underrun the input strings.
1636         */
1637        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
1638        while (a + pfx_length - pfx_adjust_for_slash <= old &&
1639               b + pfx_length - pfx_adjust_for_slash <= new &&
1640               *old == *new) {
1641                if (*old == '/')
1642                        sfx_length = len_a - (old - a);
1643                old--;
1644                new--;
1645        }
1646
1647        /*
1648         * pfx{mid-a => mid-b}sfx
1649         * {pfx-a => pfx-b}sfx
1650         * pfx{sfx-a => sfx-b}
1651         * name-a => name-b
1652         */
1653        a_midlen = len_a - pfx_length - sfx_length;
1654        b_midlen = len_b - pfx_length - sfx_length;
1655        if (a_midlen < 0)
1656                a_midlen = 0;
1657        if (b_midlen < 0)
1658                b_midlen = 0;
1659
1660        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1661        if (pfx_length + sfx_length) {
1662                strbuf_add(&name, a, pfx_length);
1663                strbuf_addch(&name, '{');
1664        }
1665        strbuf_add(&name, a + pfx_length, a_midlen);
1666        strbuf_addstr(&name, " => ");
1667        strbuf_add(&name, b + pfx_length, b_midlen);
1668        if (pfx_length + sfx_length) {
1669                strbuf_addch(&name, '}');
1670                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1671        }
1672        return strbuf_detach(&name, NULL);
1673}
1674
1675struct diffstat_t {
1676        int nr;
1677        int alloc;
1678        struct diffstat_file {
1679                char *from_name;
1680                char *name;
1681                char *print_name;
1682                unsigned is_unmerged:1;
1683                unsigned is_binary:1;
1684                unsigned is_renamed:1;
1685                unsigned is_interesting:1;
1686                uintmax_t added, deleted;
1687        } **files;
1688};
1689
1690static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1691                                          const char *name_a,
1692                                          const char *name_b)
1693{
1694        struct diffstat_file *x;
1695        x = xcalloc(1, sizeof(*x));
1696        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
1697        diffstat->files[diffstat->nr++] = x;
1698        if (name_b) {
1699                x->from_name = xstrdup(name_a);
1700                x->name = xstrdup(name_b);
1701                x->is_renamed = 1;
1702        }
1703        else {
1704                x->from_name = NULL;
1705                x->name = xstrdup(name_a);
1706        }
1707        return x;
1708}
1709
1710static void diffstat_consume(void *priv, char *line, unsigned long len)
1711{
1712        struct diffstat_t *diffstat = priv;
1713        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1714
1715        if (line[0] == '+')
1716                x->added++;
1717        else if (line[0] == '-')
1718                x->deleted++;
1719}
1720
1721const char mime_boundary_leader[] = "------------";
1722
1723static int scale_linear(int it, int width, int max_change)
1724{
1725        if (!it)
1726                return 0;
1727        /*
1728         * make sure that at least one '-' or '+' is printed if
1729         * there is any change to this path. The easiest way is to
1730         * scale linearly as if the alloted width is one column shorter
1731         * than it is, and then add 1 to the result.
1732         */
1733        return 1 + (it * (width - 1) / max_change);
1734}
1735
1736static void show_graph(struct strbuf *out, char ch, int cnt,
1737                       const char *set, const char *reset)
1738{
1739        if (cnt <= 0)
1740                return;
1741        strbuf_addstr(out, set);
1742        strbuf_addchars(out, ch, cnt);
1743        strbuf_addstr(out, reset);
1744}
1745
1746static void fill_print_name(struct diffstat_file *file)
1747{
1748        char *pname;
1749
1750        if (file->print_name)
1751                return;
1752
1753        if (!file->is_renamed) {
1754                struct strbuf buf = STRBUF_INIT;
1755                if (quote_c_style(file->name, &buf, NULL, 0)) {
1756                        pname = strbuf_detach(&buf, NULL);
1757                } else {
1758                        pname = file->name;
1759                        strbuf_release(&buf);
1760                }
1761        } else {
1762                pname = pprint_rename(file->from_name, file->name);
1763        }
1764        file->print_name = pname;
1765}
1766
1767static void print_stat_summary_inserts_deletes(struct diff_options *options,
1768                int files, int insertions, int deletions)
1769{
1770        struct strbuf sb = STRBUF_INIT;
1771
1772        if (!files) {
1773                assert(insertions == 0 && deletions == 0);
1774                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
1775                                 NULL, 0, 0);
1776                return;
1777        }
1778
1779        strbuf_addf(&sb,
1780                    (files == 1) ? " %d file changed" : " %d files changed",
1781                    files);
1782
1783        /*
1784         * For binary diff, the caller may want to print "x files
1785         * changed" with insertions == 0 && deletions == 0.
1786         *
1787         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1788         * is probably less confusing (i.e skip over "2 files changed
1789         * but nothing about added/removed lines? Is this a bug in Git?").
1790         */
1791        if (insertions || deletions == 0) {
1792                strbuf_addf(&sb,
1793                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
1794                            insertions);
1795        }
1796
1797        if (deletions || insertions == 0) {
1798                strbuf_addf(&sb,
1799                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
1800                            deletions);
1801        }
1802        strbuf_addch(&sb, '\n');
1803        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
1804                         sb.buf, sb.len, 0);
1805        strbuf_release(&sb);
1806}
1807
1808void print_stat_summary(FILE *fp, int files,
1809                        int insertions, int deletions)
1810{
1811        struct diff_options o;
1812        memset(&o, 0, sizeof(o));
1813        o.file = fp;
1814
1815        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
1816}
1817
1818static void show_stats(struct diffstat_t *data, struct diff_options *options)
1819{
1820        int i, len, add, del, adds = 0, dels = 0;
1821        uintmax_t max_change = 0, max_len = 0;
1822        int total_files = data->nr, count;
1823        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1824        const char *reset, *add_c, *del_c;
1825        int extra_shown = 0;
1826        const char *line_prefix = diff_line_prefix(options);
1827        struct strbuf out = STRBUF_INIT;
1828
1829        if (data->nr == 0)
1830                return;
1831
1832        count = options->stat_count ? options->stat_count : data->nr;
1833
1834        reset = diff_get_color_opt(options, DIFF_RESET);
1835        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1836        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1837
1838        /*
1839         * Find the longest filename and max number of changes
1840         */
1841        for (i = 0; (i < count) && (i < data->nr); i++) {
1842                struct diffstat_file *file = data->files[i];
1843                uintmax_t change = file->added + file->deleted;
1844
1845                if (!file->is_interesting && (change == 0)) {
1846                        count++; /* not shown == room for one more */
1847                        continue;
1848                }
1849                fill_print_name(file);
1850                len = strlen(file->print_name);
1851                if (max_len < len)
1852                        max_len = len;
1853
1854                if (file->is_unmerged) {
1855                        /* "Unmerged" is 8 characters */
1856                        bin_width = bin_width < 8 ? 8 : bin_width;
1857                        continue;
1858                }
1859                if (file->is_binary) {
1860                        /* "Bin XXX -> YYY bytes" */
1861                        int w = 14 + decimal_width(file->added)
1862                                + decimal_width(file->deleted);
1863                        bin_width = bin_width < w ? w : bin_width;
1864                        /* Display change counts aligned with "Bin" */
1865                        number_width = 3;
1866                        continue;
1867                }
1868
1869                if (max_change < change)
1870                        max_change = change;
1871        }
1872        count = i; /* where we can stop scanning in data->files[] */
1873
1874        /*
1875         * We have width = stat_width or term_columns() columns total.
1876         * We want a maximum of min(max_len, stat_name_width) for the name part.
1877         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1878         * We also need 1 for " " and 4 + decimal_width(max_change)
1879         * for " | NNNN " and one the empty column at the end, altogether
1880         * 6 + decimal_width(max_change).
1881         *
1882         * If there's not enough space, we will use the smaller of
1883         * stat_name_width (if set) and 5/8*width for the filename,
1884         * and the rest for constant elements + graph part, but no more
1885         * than stat_graph_width for the graph part.
1886         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1887         * for the standard terminal size).
1888         *
1889         * In other words: stat_width limits the maximum width, and
1890         * stat_name_width fixes the maximum width of the filename,
1891         * and is also used to divide available columns if there
1892         * aren't enough.
1893         *
1894         * Binary files are displayed with "Bin XXX -> YYY bytes"
1895         * instead of the change count and graph. This part is treated
1896         * similarly to the graph part, except that it is not
1897         * "scaled". If total width is too small to accommodate the
1898         * guaranteed minimum width of the filename part and the
1899         * separators and this message, this message will "overflow"
1900         * making the line longer than the maximum width.
1901         */
1902
1903        if (options->stat_width == -1)
1904                width = term_columns() - strlen(line_prefix);
1905        else
1906                width = options->stat_width ? options->stat_width : 80;
1907        number_width = decimal_width(max_change) > number_width ?
1908                decimal_width(max_change) : number_width;
1909
1910        if (options->stat_graph_width == -1)
1911                options->stat_graph_width = diff_stat_graph_width;
1912
1913        /*
1914         * Guarantee 3/8*16==6 for the graph part
1915         * and 5/8*16==10 for the filename part
1916         */
1917        if (width < 16 + 6 + number_width)
1918                width = 16 + 6 + number_width;
1919
1920        /*
1921         * First assign sizes that are wanted, ignoring available width.
1922         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1923         * starting from "XXX" should fit in graph_width.
1924         */
1925        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1926        if (options->stat_graph_width &&
1927            options->stat_graph_width < graph_width)
1928                graph_width = options->stat_graph_width;
1929
1930        name_width = (options->stat_name_width > 0 &&
1931                      options->stat_name_width < max_len) ?
1932                options->stat_name_width : max_len;
1933
1934        /*
1935         * Adjust adjustable widths not to exceed maximum width
1936         */
1937        if (name_width + number_width + 6 + graph_width > width) {
1938                if (graph_width > width * 3/8 - number_width - 6) {
1939                        graph_width = width * 3/8 - number_width - 6;
1940                        if (graph_width < 6)
1941                                graph_width = 6;
1942                }
1943
1944                if (options->stat_graph_width &&
1945                    graph_width > options->stat_graph_width)
1946                        graph_width = options->stat_graph_width;
1947                if (name_width > width - number_width - 6 - graph_width)
1948                        name_width = width - number_width - 6 - graph_width;
1949                else
1950                        graph_width = width - number_width - 6 - name_width;
1951        }
1952
1953        /*
1954         * From here name_width is the width of the name area,
1955         * and graph_width is the width of the graph area.
1956         * max_change is used to scale graph properly.
1957         */
1958        for (i = 0; i < count; i++) {
1959                const char *prefix = "";
1960                struct diffstat_file *file = data->files[i];
1961                char *name = file->print_name;
1962                uintmax_t added = file->added;
1963                uintmax_t deleted = file->deleted;
1964                int name_len;
1965
1966                if (!file->is_interesting && (added + deleted == 0))
1967                        continue;
1968
1969                /*
1970                 * "scale" the filename
1971                 */
1972                len = name_width;
1973                name_len = strlen(name);
1974                if (name_width < name_len) {
1975                        char *slash;
1976                        prefix = "...";
1977                        len -= 3;
1978                        name += name_len - len;
1979                        slash = strchr(name, '/');
1980                        if (slash)
1981                                name = slash;
1982                }
1983
1984                if (file->is_binary) {
1985                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
1986                        strbuf_addf(&out, " %*s", number_width, "Bin");
1987                        if (!added && !deleted) {
1988                                strbuf_addch(&out, '\n');
1989                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
1990                                                 out.buf, out.len, 0);
1991                                strbuf_reset(&out);
1992                                continue;
1993                        }
1994                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
1995                                del_c, deleted, reset);
1996                        strbuf_addstr(&out, " -> ");
1997                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
1998                                add_c, added, reset);
1999                        strbuf_addstr(&out, " bytes\n");
2000                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2001                                         out.buf, out.len, 0);
2002                        strbuf_reset(&out);
2003                        continue;
2004                }
2005                else if (file->is_unmerged) {
2006                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2007                        strbuf_addstr(&out, " Unmerged\n");
2008                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2009                                         out.buf, out.len, 0);
2010                        strbuf_reset(&out);
2011                        continue;
2012                }
2013
2014                /*
2015                 * scale the add/delete
2016                 */
2017                add = added;
2018                del = deleted;
2019
2020                if (graph_width <= max_change) {
2021                        int total = scale_linear(add + del, graph_width, max_change);
2022                        if (total < 2 && add && del)
2023                                /* width >= 2 due to the sanity check */
2024                                total = 2;
2025                        if (add < del) {
2026                                add = scale_linear(add, graph_width, max_change);
2027                                del = total - add;
2028                        } else {
2029                                del = scale_linear(del, graph_width, max_change);
2030                                add = total - del;
2031                        }
2032                }
2033                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2034                strbuf_addf(&out, " %*"PRIuMAX"%s",
2035                        number_width, added + deleted,
2036                        added + deleted ? " " : "");
2037                show_graph(&out, '+', add, add_c, reset);
2038                show_graph(&out, '-', del, del_c, reset);
2039                strbuf_addch(&out, '\n');
2040                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2041                                 out.buf, out.len, 0);
2042                strbuf_reset(&out);
2043        }
2044
2045        for (i = 0; i < data->nr; i++) {
2046                struct diffstat_file *file = data->files[i];
2047                uintmax_t added = file->added;
2048                uintmax_t deleted = file->deleted;
2049
2050                if (file->is_unmerged ||
2051                    (!file->is_interesting && (added + deleted == 0))) {
2052                        total_files--;
2053                        continue;
2054                }
2055
2056                if (!file->is_binary) {
2057                        adds += added;
2058                        dels += deleted;
2059                }
2060                if (i < count)
2061                        continue;
2062                if (!extra_shown)
2063                        emit_diff_symbol(options,
2064                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2065                                         NULL, 0, 0);
2066                extra_shown = 1;
2067        }
2068
2069        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2070}
2071
2072static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2073{
2074        int i, adds = 0, dels = 0, total_files = data->nr;
2075
2076        if (data->nr == 0)
2077                return;
2078
2079        for (i = 0; i < data->nr; i++) {
2080                int added = data->files[i]->added;
2081                int deleted = data->files[i]->deleted;
2082
2083                if (data->files[i]->is_unmerged ||
2084                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2085                        total_files--;
2086                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2087                        adds += added;
2088                        dels += deleted;
2089                }
2090        }
2091        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2092}
2093
2094static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2095{
2096        int i;
2097
2098        if (data->nr == 0)
2099                return;
2100
2101        for (i = 0; i < data->nr; i++) {
2102                struct diffstat_file *file = data->files[i];
2103
2104                fprintf(options->file, "%s", diff_line_prefix(options));
2105
2106                if (file->is_binary)
2107                        fprintf(options->file, "-\t-\t");
2108                else
2109                        fprintf(options->file,
2110                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2111                                file->added, file->deleted);
2112                if (options->line_termination) {
2113                        fill_print_name(file);
2114                        if (!file->is_renamed)
2115                                write_name_quoted(file->name, options->file,
2116                                                  options->line_termination);
2117                        else {
2118                                fputs(file->print_name, options->file);
2119                                putc(options->line_termination, options->file);
2120                        }
2121                } else {
2122                        if (file->is_renamed) {
2123                                putc('\0', options->file);
2124                                write_name_quoted(file->from_name, options->file, '\0');
2125                        }
2126                        write_name_quoted(file->name, options->file, '\0');
2127                }
2128        }
2129}
2130
2131struct dirstat_file {
2132        const char *name;
2133        unsigned long changed;
2134};
2135
2136struct dirstat_dir {
2137        struct dirstat_file *files;
2138        int alloc, nr, permille, cumulative;
2139};
2140
2141static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2142                unsigned long changed, const char *base, int baselen)
2143{
2144        unsigned long this_dir = 0;
2145        unsigned int sources = 0;
2146        const char *line_prefix = diff_line_prefix(opt);
2147
2148        while (dir->nr) {
2149                struct dirstat_file *f = dir->files;
2150                int namelen = strlen(f->name);
2151                unsigned long this;
2152                char *slash;
2153
2154                if (namelen < baselen)
2155                        break;
2156                if (memcmp(f->name, base, baselen))
2157                        break;
2158                slash = strchr(f->name + baselen, '/');
2159                if (slash) {
2160                        int newbaselen = slash + 1 - f->name;
2161                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2162                        sources++;
2163                } else {
2164                        this = f->changed;
2165                        dir->files++;
2166                        dir->nr--;
2167                        sources += 2;
2168                }
2169                this_dir += this;
2170        }
2171
2172        /*
2173         * We don't report dirstat's for
2174         *  - the top level
2175         *  - or cases where everything came from a single directory
2176         *    under this directory (sources == 1).
2177         */
2178        if (baselen && sources != 1) {
2179                if (this_dir) {
2180                        int permille = this_dir * 1000 / changed;
2181                        if (permille >= dir->permille) {
2182                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2183                                        permille / 10, permille % 10, baselen, base);
2184                                if (!dir->cumulative)
2185                                        return 0;
2186                        }
2187                }
2188        }
2189        return this_dir;
2190}
2191
2192static int dirstat_compare(const void *_a, const void *_b)
2193{
2194        const struct dirstat_file *a = _a;
2195        const struct dirstat_file *b = _b;
2196        return strcmp(a->name, b->name);
2197}
2198
2199static void show_dirstat(struct diff_options *options)
2200{
2201        int i;
2202        unsigned long changed;
2203        struct dirstat_dir dir;
2204        struct diff_queue_struct *q = &diff_queued_diff;
2205
2206        dir.files = NULL;
2207        dir.alloc = 0;
2208        dir.nr = 0;
2209        dir.permille = options->dirstat_permille;
2210        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2211
2212        changed = 0;
2213        for (i = 0; i < q->nr; i++) {
2214                struct diff_filepair *p = q->queue[i];
2215                const char *name;
2216                unsigned long copied, added, damage;
2217                int content_changed;
2218
2219                name = p->two->path ? p->two->path : p->one->path;
2220
2221                if (p->one->oid_valid && p->two->oid_valid)
2222                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
2223                else
2224                        content_changed = 1;
2225
2226                if (!content_changed) {
2227                        /*
2228                         * The SHA1 has not changed, so pre-/post-content is
2229                         * identical. We can therefore skip looking at the
2230                         * file contents altogether.
2231                         */
2232                        damage = 0;
2233                        goto found_damage;
2234                }
2235
2236                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
2237                        /*
2238                         * In --dirstat-by-file mode, we don't really need to
2239                         * look at the actual file contents at all.
2240                         * The fact that the SHA1 changed is enough for us to
2241                         * add this file to the list of results
2242                         * (with each file contributing equal damage).
2243                         */
2244                        damage = 1;
2245                        goto found_damage;
2246                }
2247
2248                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2249                        diff_populate_filespec(p->one, 0);
2250                        diff_populate_filespec(p->two, 0);
2251                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2252                                               &copied, &added);
2253                        diff_free_filespec_data(p->one);
2254                        diff_free_filespec_data(p->two);
2255                } else if (DIFF_FILE_VALID(p->one)) {
2256                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2257                        copied = added = 0;
2258                        diff_free_filespec_data(p->one);
2259                } else if (DIFF_FILE_VALID(p->two)) {
2260                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2261                        copied = 0;
2262                        added = p->two->size;
2263                        diff_free_filespec_data(p->two);
2264                } else
2265                        continue;
2266
2267                /*
2268                 * Original minus copied is the removed material,
2269                 * added is the new material.  They are both damages
2270                 * made to the preimage.
2271                 * If the resulting damage is zero, we know that
2272                 * diffcore_count_changes() considers the two entries to
2273                 * be identical, but since content_changed is true, we
2274                 * know that there must have been _some_ kind of change,
2275                 * so we force all entries to have damage > 0.
2276                 */
2277                damage = (p->one->size - copied) + added;
2278                if (!damage)
2279                        damage = 1;
2280
2281found_damage:
2282                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2283                dir.files[dir.nr].name = name;
2284                dir.files[dir.nr].changed = damage;
2285                changed += damage;
2286                dir.nr++;
2287        }
2288
2289        /* This can happen even with many files, if everything was renames */
2290        if (!changed)
2291                return;
2292
2293        /* Show all directories with more than x% of the changes */
2294        QSORT(dir.files, dir.nr, dirstat_compare);
2295        gather_dirstat(options, &dir, changed, "", 0);
2296}
2297
2298static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2299{
2300        int i;
2301        unsigned long changed;
2302        struct dirstat_dir dir;
2303
2304        if (data->nr == 0)
2305                return;
2306
2307        dir.files = NULL;
2308        dir.alloc = 0;
2309        dir.nr = 0;
2310        dir.permille = options->dirstat_permille;
2311        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2312
2313        changed = 0;
2314        for (i = 0; i < data->nr; i++) {
2315                struct diffstat_file *file = data->files[i];
2316                unsigned long damage = file->added + file->deleted;
2317                if (file->is_binary)
2318                        /*
2319                         * binary files counts bytes, not lines. Must find some
2320                         * way to normalize binary bytes vs. textual lines.
2321                         * The following heuristic assumes that there are 64
2322                         * bytes per "line".
2323                         * This is stupid and ugly, but very cheap...
2324                         */
2325                        damage = (damage + 63) / 64;
2326                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2327                dir.files[dir.nr].name = file->name;
2328                dir.files[dir.nr].changed = damage;
2329                changed += damage;
2330                dir.nr++;
2331        }
2332
2333        /* This can happen even with many files, if everything was renames */
2334        if (!changed)
2335                return;
2336
2337        /* Show all directories with more than x% of the changes */
2338        QSORT(dir.files, dir.nr, dirstat_compare);
2339        gather_dirstat(options, &dir, changed, "", 0);
2340}
2341
2342static void free_diffstat_info(struct diffstat_t *diffstat)
2343{
2344        int i;
2345        for (i = 0; i < diffstat->nr; i++) {
2346                struct diffstat_file *f = diffstat->files[i];
2347                if (f->name != f->print_name)
2348                        free(f->print_name);
2349                free(f->name);
2350                free(f->from_name);
2351                free(f);
2352        }
2353        free(diffstat->files);
2354}
2355
2356struct checkdiff_t {
2357        const char *filename;
2358        int lineno;
2359        int conflict_marker_size;
2360        struct diff_options *o;
2361        unsigned ws_rule;
2362        unsigned status;
2363};
2364
2365static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2366{
2367        char firstchar;
2368        int cnt;
2369
2370        if (len < marker_size + 1)
2371                return 0;
2372        firstchar = line[0];
2373        switch (firstchar) {
2374        case '=': case '>': case '<': case '|':
2375                break;
2376        default:
2377                return 0;
2378        }
2379        for (cnt = 1; cnt < marker_size; cnt++)
2380                if (line[cnt] != firstchar)
2381                        return 0;
2382        /* line[1] thru line[marker_size-1] are same as firstchar */
2383        if (len < marker_size + 1 || !isspace(line[marker_size]))
2384                return 0;
2385        return 1;
2386}
2387
2388static void checkdiff_consume(void *priv, char *line, unsigned long len)
2389{
2390        struct checkdiff_t *data = priv;
2391        int marker_size = data->conflict_marker_size;
2392        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2393        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2394        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2395        char *err;
2396        const char *line_prefix;
2397
2398        assert(data->o);
2399        line_prefix = diff_line_prefix(data->o);
2400
2401        if (line[0] == '+') {
2402                unsigned bad;
2403                data->lineno++;
2404                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2405                        data->status |= 1;
2406                        fprintf(data->o->file,
2407                                "%s%s:%d: leftover conflict marker\n",
2408                                line_prefix, data->filename, data->lineno);
2409                }
2410                bad = ws_check(line + 1, len - 1, data->ws_rule);
2411                if (!bad)
2412                        return;
2413                data->status |= bad;
2414                err = whitespace_error_string(bad);
2415                fprintf(data->o->file, "%s%s:%d: %s.\n",
2416                        line_prefix, data->filename, data->lineno, err);
2417                free(err);
2418                emit_line(data->o, set, reset, line, 1);
2419                ws_check_emit(line + 1, len - 1, data->ws_rule,
2420                              data->o->file, set, reset, ws);
2421        } else if (line[0] == ' ') {
2422                data->lineno++;
2423        } else if (line[0] == '@') {
2424                char *plus = strchr(line, '+');
2425                if (plus)
2426                        data->lineno = strtol(plus, NULL, 10) - 1;
2427                else
2428                        die("invalid diff");
2429        }
2430}
2431
2432static unsigned char *deflate_it(char *data,
2433                                 unsigned long size,
2434                                 unsigned long *result_size)
2435{
2436        int bound;
2437        unsigned char *deflated;
2438        git_zstream stream;
2439
2440        git_deflate_init(&stream, zlib_compression_level);
2441        bound = git_deflate_bound(&stream, size);
2442        deflated = xmalloc(bound);
2443        stream.next_out = deflated;
2444        stream.avail_out = bound;
2445
2446        stream.next_in = (unsigned char *)data;
2447        stream.avail_in = size;
2448        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2449                ; /* nothing */
2450        git_deflate_end(&stream);
2451        *result_size = stream.total_out;
2452        return deflated;
2453}
2454
2455static void emit_binary_diff_body(struct diff_options *o,
2456                                  mmfile_t *one, mmfile_t *two)
2457{
2458        void *cp;
2459        void *delta;
2460        void *deflated;
2461        void *data;
2462        unsigned long orig_size;
2463        unsigned long delta_size;
2464        unsigned long deflate_size;
2465        unsigned long data_size;
2466
2467        /* We could do deflated delta, or we could do just deflated two,
2468         * whichever is smaller.
2469         */
2470        delta = NULL;
2471        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2472        if (one->size && two->size) {
2473                delta = diff_delta(one->ptr, one->size,
2474                                   two->ptr, two->size,
2475                                   &delta_size, deflate_size);
2476                if (delta) {
2477                        void *to_free = delta;
2478                        orig_size = delta_size;
2479                        delta = deflate_it(delta, delta_size, &delta_size);
2480                        free(to_free);
2481                }
2482        }
2483
2484        if (delta && delta_size < deflate_size) {
2485                char *s = xstrfmt("%lu", orig_size);
2486                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
2487                                 s, strlen(s), 0);
2488                free(s);
2489                free(deflated);
2490                data = delta;
2491                data_size = delta_size;
2492        } else {
2493                char *s = xstrfmt("%lu", two->size);
2494                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
2495                                 s, strlen(s), 0);
2496                free(s);
2497                free(delta);
2498                data = deflated;
2499                data_size = deflate_size;
2500        }
2501
2502        /* emit data encoded in base85 */
2503        cp = data;
2504        while (data_size) {
2505                int len;
2506                int bytes = (52 < data_size) ? 52 : data_size;
2507                char line[71];
2508                data_size -= bytes;
2509                if (bytes <= 26)
2510                        line[0] = bytes + 'A' - 1;
2511                else
2512                        line[0] = bytes - 26 + 'a' - 1;
2513                encode_85(line + 1, cp, bytes);
2514                cp = (char *) cp + bytes;
2515
2516                len = strlen(line);
2517                line[len++] = '\n';
2518                line[len] = '\0';
2519
2520                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
2521                                 line, len, 0);
2522        }
2523        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
2524        free(data);
2525}
2526
2527static void emit_binary_diff(struct diff_options *o,
2528                             mmfile_t *one, mmfile_t *two)
2529{
2530        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
2531        emit_binary_diff_body(o, one, two);
2532        emit_binary_diff_body(o, two, one);
2533}
2534
2535int diff_filespec_is_binary(struct diff_filespec *one)
2536{
2537        if (one->is_binary == -1) {
2538                diff_filespec_load_driver(one);
2539                if (one->driver->binary != -1)
2540                        one->is_binary = one->driver->binary;
2541                else {
2542                        if (!one->data && DIFF_FILE_VALID(one))
2543                                diff_populate_filespec(one, CHECK_BINARY);
2544                        if (one->is_binary == -1 && one->data)
2545                                one->is_binary = buffer_is_binary(one->data,
2546                                                one->size);
2547                        if (one->is_binary == -1)
2548                                one->is_binary = 0;
2549                }
2550        }
2551        return one->is_binary;
2552}
2553
2554static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2555{
2556        diff_filespec_load_driver(one);
2557        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2558}
2559
2560void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2561{
2562        if (!options->a_prefix)
2563                options->a_prefix = a;
2564        if (!options->b_prefix)
2565                options->b_prefix = b;
2566}
2567
2568struct userdiff_driver *get_textconv(struct diff_filespec *one)
2569{
2570        if (!DIFF_FILE_VALID(one))
2571                return NULL;
2572
2573        diff_filespec_load_driver(one);
2574        return userdiff_get_textconv(one->driver);
2575}
2576
2577static void builtin_diff(const char *name_a,
2578                         const char *name_b,
2579                         struct diff_filespec *one,
2580                         struct diff_filespec *two,
2581                         const char *xfrm_msg,
2582                         int must_show_header,
2583                         struct diff_options *o,
2584                         int complete_rewrite)
2585{
2586        mmfile_t mf1, mf2;
2587        const char *lbl[2];
2588        char *a_one, *b_two;
2589        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
2590        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2591        const char *a_prefix, *b_prefix;
2592        struct userdiff_driver *textconv_one = NULL;
2593        struct userdiff_driver *textconv_two = NULL;
2594        struct strbuf header = STRBUF_INIT;
2595        const char *line_prefix = diff_line_prefix(o);
2596
2597        diff_set_mnemonic_prefix(o, "a/", "b/");
2598        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2599                a_prefix = o->b_prefix;
2600                b_prefix = o->a_prefix;
2601        } else {
2602                a_prefix = o->a_prefix;
2603                b_prefix = o->b_prefix;
2604        }
2605
2606        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
2607            (!one->mode || S_ISGITLINK(one->mode)) &&
2608            (!two->mode || S_ISGITLINK(two->mode))) {
2609                show_submodule_summary(o, one->path ? one->path : two->path,
2610                                &one->oid, &two->oid,
2611                                two->dirty_submodule);
2612                return;
2613        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
2614                   (!one->mode || S_ISGITLINK(one->mode)) &&
2615                   (!two->mode || S_ISGITLINK(two->mode))) {
2616                show_submodule_inline_diff(o, one->path ? one->path : two->path,
2617                                &one->oid, &two->oid,
2618                                two->dirty_submodule);
2619                return;
2620        }
2621
2622        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2623                textconv_one = get_textconv(one);
2624                textconv_two = get_textconv(two);
2625        }
2626
2627        /* Never use a non-valid filename anywhere if at all possible */
2628        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2629        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2630
2631        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2632        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2633        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2634        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2635        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
2636        if (lbl[0][0] == '/') {
2637                /* /dev/null */
2638                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
2639                if (xfrm_msg)
2640                        strbuf_addstr(&header, xfrm_msg);
2641                must_show_header = 1;
2642        }
2643        else if (lbl[1][0] == '/') {
2644                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
2645                if (xfrm_msg)
2646                        strbuf_addstr(&header, xfrm_msg);
2647                must_show_header = 1;
2648        }
2649        else {
2650                if (one->mode != two->mode) {
2651                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
2652                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
2653                        must_show_header = 1;
2654                }
2655                if (xfrm_msg)
2656                        strbuf_addstr(&header, xfrm_msg);
2657
2658                /*
2659                 * we do not run diff between different kind
2660                 * of objects.
2661                 */
2662                if ((one->mode ^ two->mode) & S_IFMT)
2663                        goto free_ab_and_return;
2664                if (complete_rewrite &&
2665                    (textconv_one || !diff_filespec_is_binary(one)) &&
2666                    (textconv_two || !diff_filespec_is_binary(two))) {
2667                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2668                                         header.buf, header.len, 0);
2669                        strbuf_reset(&header);
2670                        emit_rewrite_diff(name_a, name_b, one, two,
2671                                                textconv_one, textconv_two, o);
2672                        o->found_changes = 1;
2673                        goto free_ab_and_return;
2674                }
2675        }
2676
2677        if (o->irreversible_delete && lbl[1][0] == '/') {
2678                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
2679                                 header.len, 0);
2680                strbuf_reset(&header);
2681                goto free_ab_and_return;
2682        } else if (!DIFF_OPT_TST(o, TEXT) &&
2683            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2684              (!textconv_two && diff_filespec_is_binary(two)) )) {
2685                struct strbuf sb = STRBUF_INIT;
2686                if (!one->data && !two->data &&
2687                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
2688                    !DIFF_OPT_TST(o, BINARY)) {
2689                        if (!oidcmp(&one->oid, &two->oid)) {
2690                                if (must_show_header)
2691                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2692                                                         header.buf, header.len,
2693                                                         0);
2694                                goto free_ab_and_return;
2695                        }
2696                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2697                                         header.buf, header.len, 0);
2698                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
2699                                    diff_line_prefix(o), lbl[0], lbl[1]);
2700                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
2701                                         sb.buf, sb.len, 0);
2702                        strbuf_release(&sb);
2703                        goto free_ab_and_return;
2704                }
2705                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2706                        die("unable to read files to diff");
2707                /* Quite common confusing case */
2708                if (mf1.size == mf2.size &&
2709                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2710                        if (must_show_header)
2711                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2712                                                 header.buf, header.len, 0);
2713                        goto free_ab_and_return;
2714                }
2715                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
2716                strbuf_reset(&header);
2717                if (DIFF_OPT_TST(o, BINARY))
2718                        emit_binary_diff(o, &mf1, &mf2);
2719                else {
2720                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
2721                                    diff_line_prefix(o), lbl[0], lbl[1]);
2722                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
2723                                         sb.buf, sb.len, 0);
2724                        strbuf_release(&sb);
2725                }
2726                o->found_changes = 1;
2727        } else {
2728                /* Crazy xdl interfaces.. */
2729                const char *diffopts = getenv("GIT_DIFF_OPTS");
2730                const char *v;
2731                xpparam_t xpp;
2732                xdemitconf_t xecfg;
2733                struct emit_callback ecbdata;
2734                const struct userdiff_funcname *pe;
2735
2736                if (must_show_header) {
2737                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2738                                         header.buf, header.len, 0);
2739                        strbuf_reset(&header);
2740                }
2741
2742                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2743                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2744
2745                pe = diff_funcname_pattern(one);
2746                if (!pe)
2747                        pe = diff_funcname_pattern(two);
2748
2749                memset(&xpp, 0, sizeof(xpp));
2750                memset(&xecfg, 0, sizeof(xecfg));
2751                memset(&ecbdata, 0, sizeof(ecbdata));
2752                ecbdata.label_path = lbl;
2753                ecbdata.color_diff = want_color(o->use_color);
2754                ecbdata.ws_rule = whitespace_rule(name_b);
2755                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2756                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2757                ecbdata.opt = o;
2758                ecbdata.header = header.len ? &header : NULL;
2759                xpp.flags = o->xdl_opts;
2760                xecfg.ctxlen = o->context;
2761                xecfg.interhunkctxlen = o->interhunkcontext;
2762                xecfg.flags = XDL_EMIT_FUNCNAMES;
2763                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2764                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2765                if (pe)
2766                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2767                if (!diffopts)
2768                        ;
2769                else if (skip_prefix(diffopts, "--unified=", &v))
2770                        xecfg.ctxlen = strtoul(v, NULL, 10);
2771                else if (skip_prefix(diffopts, "-u", &v))
2772                        xecfg.ctxlen = strtoul(v, NULL, 10);
2773                if (o->word_diff)
2774                        init_diff_words_data(&ecbdata, o, one, two);
2775                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2776                                  &xpp, &xecfg))
2777                        die("unable to generate diff for %s", one->path);
2778                if (o->word_diff)
2779                        free_diff_words_data(&ecbdata);
2780                if (textconv_one)
2781                        free(mf1.ptr);
2782                if (textconv_two)
2783                        free(mf2.ptr);
2784                xdiff_clear_find_func(&xecfg);
2785        }
2786
2787 free_ab_and_return:
2788        strbuf_release(&header);
2789        diff_free_filespec_data(one);
2790        diff_free_filespec_data(two);
2791        free(a_one);
2792        free(b_two);
2793        return;
2794}
2795
2796static void builtin_diffstat(const char *name_a, const char *name_b,
2797                             struct diff_filespec *one,
2798                             struct diff_filespec *two,
2799                             struct diffstat_t *diffstat,
2800                             struct diff_options *o,
2801                             struct diff_filepair *p)
2802{
2803        mmfile_t mf1, mf2;
2804        struct diffstat_file *data;
2805        int same_contents;
2806        int complete_rewrite = 0;
2807
2808        if (!DIFF_PAIR_UNMERGED(p)) {
2809                if (p->status == DIFF_STATUS_MODIFIED && p->score)
2810                        complete_rewrite = 1;
2811        }
2812
2813        data = diffstat_add(diffstat, name_a, name_b);
2814        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
2815
2816        if (!one || !two) {
2817                data->is_unmerged = 1;
2818                return;
2819        }
2820
2821        same_contents = !oidcmp(&one->oid, &two->oid);
2822
2823        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2824                data->is_binary = 1;
2825                if (same_contents) {
2826                        data->added = 0;
2827                        data->deleted = 0;
2828                } else {
2829                        data->added = diff_filespec_size(two);
2830                        data->deleted = diff_filespec_size(one);
2831                }
2832        }
2833
2834        else if (complete_rewrite) {
2835                diff_populate_filespec(one, 0);
2836                diff_populate_filespec(two, 0);
2837                data->deleted = count_lines(one->data, one->size);
2838                data->added = count_lines(two->data, two->size);
2839        }
2840
2841        else if (!same_contents) {
2842                /* Crazy xdl interfaces.. */
2843                xpparam_t xpp;
2844                xdemitconf_t xecfg;
2845
2846                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2847                        die("unable to read files to diff");
2848
2849                memset(&xpp, 0, sizeof(xpp));
2850                memset(&xecfg, 0, sizeof(xecfg));
2851                xpp.flags = o->xdl_opts;
2852                xecfg.ctxlen = o->context;
2853                xecfg.interhunkctxlen = o->interhunkcontext;
2854                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2855                                  &xpp, &xecfg))
2856                        die("unable to generate diffstat for %s", one->path);
2857        }
2858
2859        diff_free_filespec_data(one);
2860        diff_free_filespec_data(two);
2861}
2862
2863static void builtin_checkdiff(const char *name_a, const char *name_b,
2864                              const char *attr_path,
2865                              struct diff_filespec *one,
2866                              struct diff_filespec *two,
2867                              struct diff_options *o)
2868{
2869        mmfile_t mf1, mf2;
2870        struct checkdiff_t data;
2871
2872        if (!two)
2873                return;
2874
2875        memset(&data, 0, sizeof(data));
2876        data.filename = name_b ? name_b : name_a;
2877        data.lineno = 0;
2878        data.o = o;
2879        data.ws_rule = whitespace_rule(attr_path);
2880        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2881
2882        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2883                die("unable to read files to diff");
2884
2885        /*
2886         * All the other codepaths check both sides, but not checking
2887         * the "old" side here is deliberate.  We are checking the newly
2888         * introduced changes, and as long as the "new" side is text, we
2889         * can and should check what it introduces.
2890         */
2891        if (diff_filespec_is_binary(two))
2892                goto free_and_return;
2893        else {
2894                /* Crazy xdl interfaces.. */
2895                xpparam_t xpp;
2896                xdemitconf_t xecfg;
2897
2898                memset(&xpp, 0, sizeof(xpp));
2899                memset(&xecfg, 0, sizeof(xecfg));
2900                xecfg.ctxlen = 1; /* at least one context line */
2901                xpp.flags = 0;
2902                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2903                                  &xpp, &xecfg))
2904                        die("unable to generate checkdiff for %s", one->path);
2905
2906                if (data.ws_rule & WS_BLANK_AT_EOF) {
2907                        struct emit_callback ecbdata;
2908                        int blank_at_eof;
2909
2910                        ecbdata.ws_rule = data.ws_rule;
2911                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2912                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2913
2914                        if (blank_at_eof) {
2915                                static char *err;
2916                                if (!err)
2917                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2918                                fprintf(o->file, "%s:%d: %s.\n",
2919                                        data.filename, blank_at_eof, err);
2920                                data.status = 1; /* report errors */
2921                        }
2922                }
2923        }
2924 free_and_return:
2925        diff_free_filespec_data(one);
2926        diff_free_filespec_data(two);
2927        if (data.status)
2928                DIFF_OPT_SET(o, CHECK_FAILED);
2929}
2930
2931struct diff_filespec *alloc_filespec(const char *path)
2932{
2933        struct diff_filespec *spec;
2934
2935        FLEXPTR_ALLOC_STR(spec, path, path);
2936        spec->count = 1;
2937        spec->is_binary = -1;
2938        return spec;
2939}
2940
2941void free_filespec(struct diff_filespec *spec)
2942{
2943        if (!--spec->count) {
2944                diff_free_filespec_data(spec);
2945                free(spec);
2946        }
2947}
2948
2949void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
2950                   int oid_valid, unsigned short mode)
2951{
2952        if (mode) {
2953                spec->mode = canon_mode(mode);
2954                oidcpy(&spec->oid, oid);
2955                spec->oid_valid = oid_valid;
2956        }
2957}
2958
2959/*
2960 * Given a name and sha1 pair, if the index tells us the file in
2961 * the work tree has that object contents, return true, so that
2962 * prepare_temp_file() does not have to inflate and extract.
2963 */
2964static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
2965{
2966        const struct cache_entry *ce;
2967        struct stat st;
2968        int pos, len;
2969
2970        /*
2971         * We do not read the cache ourselves here, because the
2972         * benchmark with my previous version that always reads cache
2973         * shows that it makes things worse for diff-tree comparing
2974         * two linux-2.6 kernel trees in an already checked out work
2975         * tree.  This is because most diff-tree comparisons deal with
2976         * only a small number of files, while reading the cache is
2977         * expensive for a large project, and its cost outweighs the
2978         * savings we get by not inflating the object to a temporary
2979         * file.  Practically, this code only helps when we are used
2980         * by diff-cache --cached, which does read the cache before
2981         * calling us.
2982         */
2983        if (!active_cache)
2984                return 0;
2985
2986        /* We want to avoid the working directory if our caller
2987         * doesn't need the data in a normal file, this system
2988         * is rather slow with its stat/open/mmap/close syscalls,
2989         * and the object is contained in a pack file.  The pack
2990         * is probably already open and will be faster to obtain
2991         * the data through than the working directory.  Loose
2992         * objects however would tend to be slower as they need
2993         * to be individually opened and inflated.
2994         */
2995        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(oid->hash))
2996                return 0;
2997
2998        /*
2999         * Similarly, if we'd have to convert the file contents anyway, that
3000         * makes the optimization not worthwhile.
3001         */
3002        if (!want_file && would_convert_to_git(&the_index, name))
3003                return 0;
3004
3005        len = strlen(name);
3006        pos = cache_name_pos(name, len);
3007        if (pos < 0)
3008                return 0;
3009        ce = active_cache[pos];
3010
3011        /*
3012         * This is not the sha1 we are looking for, or
3013         * unreusable because it is not a regular file.
3014         */
3015        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3016                return 0;
3017
3018        /*
3019         * If ce is marked as "assume unchanged", there is no
3020         * guarantee that work tree matches what we are looking for.
3021         */
3022        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3023                return 0;
3024
3025        /*
3026         * If ce matches the file in the work tree, we can reuse it.
3027         */
3028        if (ce_uptodate(ce) ||
3029            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
3030                return 1;
3031
3032        return 0;
3033}
3034
3035static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3036{
3037        struct strbuf buf = STRBUF_INIT;
3038        char *dirty = "";
3039
3040        /* Are we looking at the work tree? */
3041        if (s->dirty_submodule)
3042                dirty = "-dirty";
3043
3044        strbuf_addf(&buf, "Subproject commit %s%s\n",
3045                    oid_to_hex(&s->oid), dirty);
3046        s->size = buf.len;
3047        if (size_only) {
3048                s->data = NULL;
3049                strbuf_release(&buf);
3050        } else {
3051                s->data = strbuf_detach(&buf, NULL);
3052                s->should_free = 1;
3053        }
3054        return 0;
3055}
3056
3057/*
3058 * While doing rename detection and pickaxe operation, we may need to
3059 * grab the data for the blob (or file) for our own in-core comparison.
3060 * diff_filespec has data and size fields for this purpose.
3061 */
3062int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
3063{
3064        int size_only = flags & CHECK_SIZE_ONLY;
3065        int err = 0;
3066        /*
3067         * demote FAIL to WARN to allow inspecting the situation
3068         * instead of refusing.
3069         */
3070        enum safe_crlf crlf_warn = (safe_crlf == SAFE_CRLF_FAIL
3071                                    ? SAFE_CRLF_WARN
3072                                    : safe_crlf);
3073
3074        if (!DIFF_FILE_VALID(s))
3075                die("internal error: asking to populate invalid file.");
3076        if (S_ISDIR(s->mode))
3077                return -1;
3078
3079        if (s->data)
3080                return 0;
3081
3082        if (size_only && 0 < s->size)
3083                return 0;
3084
3085        if (S_ISGITLINK(s->mode))
3086                return diff_populate_gitlink(s, size_only);
3087
3088        if (!s->oid_valid ||
3089            reuse_worktree_file(s->path, &s->oid, 0)) {
3090                struct strbuf buf = STRBUF_INIT;
3091                struct stat st;
3092                int fd;
3093
3094                if (lstat(s->path, &st) < 0) {
3095                        if (errno == ENOENT) {
3096                        err_empty:
3097                                err = -1;
3098                        empty:
3099                                s->data = (char *)"";
3100                                s->size = 0;
3101                                return err;
3102                        }
3103                }
3104                s->size = xsize_t(st.st_size);
3105                if (!s->size)
3106                        goto empty;
3107                if (S_ISLNK(st.st_mode)) {
3108                        struct strbuf sb = STRBUF_INIT;
3109
3110                        if (strbuf_readlink(&sb, s->path, s->size))
3111                                goto err_empty;
3112                        s->size = sb.len;
3113                        s->data = strbuf_detach(&sb, NULL);
3114                        s->should_free = 1;
3115                        return 0;
3116                }
3117
3118                /*
3119                 * Even if the caller would be happy with getting
3120                 * only the size, we cannot return early at this
3121                 * point if the path requires us to run the content
3122                 * conversion.
3123                 */
3124                if (size_only && !would_convert_to_git(&the_index, s->path))
3125                        return 0;
3126
3127                /*
3128                 * Note: this check uses xsize_t(st.st_size) that may
3129                 * not be the true size of the blob after it goes
3130                 * through convert_to_git().  This may not strictly be
3131                 * correct, but the whole point of big_file_threshold
3132                 * and is_binary check being that we want to avoid
3133                 * opening the file and inspecting the contents, this
3134                 * is probably fine.
3135                 */
3136                if ((flags & CHECK_BINARY) &&
3137                    s->size > big_file_threshold && s->is_binary == -1) {
3138                        s->is_binary = 1;
3139                        return 0;
3140                }
3141                fd = open(s->path, O_RDONLY);
3142                if (fd < 0)
3143                        goto err_empty;
3144                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3145                close(fd);
3146                s->should_munmap = 1;
3147
3148                /*
3149                 * Convert from working tree format to canonical git format
3150                 */
3151                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, crlf_warn)) {
3152                        size_t size = 0;
3153                        munmap(s->data, s->size);
3154                        s->should_munmap = 0;
3155                        s->data = strbuf_detach(&buf, &size);
3156                        s->size = size;
3157                        s->should_free = 1;
3158                }
3159        }
3160        else {
3161                enum object_type type;
3162                if (size_only || (flags & CHECK_BINARY)) {
3163                        type = sha1_object_info(s->oid.hash, &s->size);
3164                        if (type < 0)
3165                                die("unable to read %s",
3166                                    oid_to_hex(&s->oid));
3167                        if (size_only)
3168                                return 0;
3169                        if (s->size > big_file_threshold && s->is_binary == -1) {
3170                                s->is_binary = 1;
3171                                return 0;
3172                        }
3173                }
3174                s->data = read_sha1_file(s->oid.hash, &type, &s->size);
3175                if (!s->data)
3176                        die("unable to read %s", oid_to_hex(&s->oid));
3177                s->should_free = 1;
3178        }
3179        return 0;
3180}
3181
3182void diff_free_filespec_blob(struct diff_filespec *s)
3183{
3184        if (s->should_free)
3185                free(s->data);
3186        else if (s->should_munmap)
3187                munmap(s->data, s->size);
3188
3189        if (s->should_free || s->should_munmap) {
3190                s->should_free = s->should_munmap = 0;
3191                s->data = NULL;
3192        }
3193}
3194
3195void diff_free_filespec_data(struct diff_filespec *s)
3196{
3197        diff_free_filespec_blob(s);
3198        FREE_AND_NULL(s->cnt_data);
3199}
3200
3201static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
3202                           void *blob,
3203                           unsigned long size,
3204                           const struct object_id *oid,
3205                           int mode)
3206{
3207        int fd;
3208        struct strbuf buf = STRBUF_INIT;
3209        struct strbuf template = STRBUF_INIT;
3210        char *path_dup = xstrdup(path);
3211        const char *base = basename(path_dup);
3212
3213        /* Generate "XXXXXX_basename.ext" */
3214        strbuf_addstr(&template, "XXXXXX_");
3215        strbuf_addstr(&template, base);
3216
3217        fd = mks_tempfile_ts(&temp->tempfile, template.buf, strlen(base) + 1);
3218        if (fd < 0)
3219                die_errno("unable to create temp-file");
3220        if (convert_to_working_tree(path,
3221                        (const char *)blob, (size_t)size, &buf)) {
3222                blob = buf.buf;
3223                size = buf.len;
3224        }
3225        if (write_in_full(fd, blob, size) != size)
3226                die_errno("unable to write temp-file");
3227        close_tempfile(&temp->tempfile);
3228        temp->name = get_tempfile_path(&temp->tempfile);
3229        oid_to_hex_r(temp->hex, oid);
3230        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3231        strbuf_release(&buf);
3232        strbuf_release(&template);
3233        free(path_dup);
3234}
3235
3236static struct diff_tempfile *prepare_temp_file(const char *name,
3237                struct diff_filespec *one)
3238{
3239        struct diff_tempfile *temp = claim_diff_tempfile();
3240
3241        if (!DIFF_FILE_VALID(one)) {
3242        not_a_valid_file:
3243                /* A '-' entry produces this for file-2, and
3244                 * a '+' entry produces this for file-1.
3245                 */
3246                temp->name = "/dev/null";
3247                xsnprintf(temp->hex, sizeof(temp->hex), ".");
3248                xsnprintf(temp->mode, sizeof(temp->mode), ".");
3249                return temp;
3250        }
3251
3252        if (!S_ISGITLINK(one->mode) &&
3253            (!one->oid_valid ||
3254             reuse_worktree_file(name, &one->oid, 1))) {
3255                struct stat st;
3256                if (lstat(name, &st) < 0) {
3257                        if (errno == ENOENT)
3258                                goto not_a_valid_file;
3259                        die_errno("stat(%s)", name);
3260                }
3261                if (S_ISLNK(st.st_mode)) {
3262                        struct strbuf sb = STRBUF_INIT;
3263                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
3264                                die_errno("readlink(%s)", name);
3265                        prep_temp_blob(name, temp, sb.buf, sb.len,
3266                                       (one->oid_valid ?
3267                                        &one->oid : &null_oid),
3268                                       (one->oid_valid ?
3269                                        one->mode : S_IFLNK));
3270                        strbuf_release(&sb);
3271                }
3272                else {
3273                        /* we can borrow from the file in the work tree */
3274                        temp->name = name;
3275                        if (!one->oid_valid)
3276                                oid_to_hex_r(temp->hex, &null_oid);
3277                        else
3278                                oid_to_hex_r(temp->hex, &one->oid);
3279                        /* Even though we may sometimes borrow the
3280                         * contents from the work tree, we always want
3281                         * one->mode.  mode is trustworthy even when
3282                         * !(one->oid_valid), as long as
3283                         * DIFF_FILE_VALID(one).
3284                         */
3285                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
3286                }
3287                return temp;
3288        }
3289        else {
3290                if (diff_populate_filespec(one, 0))
3291                        die("cannot read data blob for %s", one->path);
3292                prep_temp_blob(name, temp, one->data, one->size,
3293                               &one->oid, one->mode);
3294        }
3295        return temp;
3296}
3297
3298static void add_external_diff_name(struct argv_array *argv,
3299                                   const char *name,
3300                                   struct diff_filespec *df)
3301{
3302        struct diff_tempfile *temp = prepare_temp_file(name, df);
3303        argv_array_push(argv, temp->name);
3304        argv_array_push(argv, temp->hex);
3305        argv_array_push(argv, temp->mode);
3306}
3307
3308/* An external diff command takes:
3309 *
3310 * diff-cmd name infile1 infile1-sha1 infile1-mode \
3311 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
3312 *
3313 */
3314static void run_external_diff(const char *pgm,
3315                              const char *name,
3316                              const char *other,
3317                              struct diff_filespec *one,
3318                              struct diff_filespec *two,
3319                              const char *xfrm_msg,
3320                              int complete_rewrite,
3321                              struct diff_options *o)
3322{
3323        struct argv_array argv = ARGV_ARRAY_INIT;
3324        struct argv_array env = ARGV_ARRAY_INIT;
3325        struct diff_queue_struct *q = &diff_queued_diff;
3326
3327        argv_array_push(&argv, pgm);
3328        argv_array_push(&argv, name);
3329
3330        if (one && two) {
3331                add_external_diff_name(&argv, name, one);
3332                if (!other)
3333                        add_external_diff_name(&argv, name, two);
3334                else {
3335                        add_external_diff_name(&argv, other, two);
3336                        argv_array_push(&argv, other);
3337                        argv_array_push(&argv, xfrm_msg);
3338                }
3339        }
3340
3341        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
3342        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
3343
3344        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
3345                die(_("external diff died, stopping at %s"), name);
3346
3347        remove_tempfile();
3348        argv_array_clear(&argv);
3349        argv_array_clear(&env);
3350}
3351
3352static int similarity_index(struct diff_filepair *p)
3353{
3354        return p->score * 100 / MAX_SCORE;
3355}
3356
3357static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
3358{
3359        if (startup_info->have_repository)
3360                return find_unique_abbrev(oid->hash, abbrev);
3361        else {
3362                char *hex = oid_to_hex(oid);
3363                if (abbrev < 0)
3364                        abbrev = FALLBACK_DEFAULT_ABBREV;
3365                if (abbrev > GIT_SHA1_HEXSZ)
3366                        die("BUG: oid abbreviation out of range: %d", abbrev);
3367                if (abbrev)
3368                        hex[abbrev] = '\0';
3369                return hex;
3370        }
3371}
3372
3373static void fill_metainfo(struct strbuf *msg,
3374                          const char *name,
3375                          const char *other,
3376                          struct diff_filespec *one,
3377                          struct diff_filespec *two,
3378                          struct diff_options *o,
3379                          struct diff_filepair *p,
3380                          int *must_show_header,
3381                          int use_color)
3382{
3383        const char *set = diff_get_color(use_color, DIFF_METAINFO);
3384        const char *reset = diff_get_color(use_color, DIFF_RESET);
3385        const char *line_prefix = diff_line_prefix(o);
3386
3387        *must_show_header = 1;
3388        strbuf_init(msg, PATH_MAX * 2 + 300);
3389        switch (p->status) {
3390        case DIFF_STATUS_COPIED:
3391                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3392                            line_prefix, set, similarity_index(p));
3393                strbuf_addf(msg, "%s\n%s%scopy from ",
3394                            reset,  line_prefix, set);
3395                quote_c_style(name, msg, NULL, 0);
3396                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3397                quote_c_style(other, msg, NULL, 0);
3398                strbuf_addf(msg, "%s\n", reset);
3399                break;
3400        case DIFF_STATUS_RENAMED:
3401                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3402                            line_prefix, set, similarity_index(p));
3403                strbuf_addf(msg, "%s\n%s%srename from ",
3404                            reset, line_prefix, set);
3405                quote_c_style(name, msg, NULL, 0);
3406                strbuf_addf(msg, "%s\n%s%srename to ",
3407                            reset, line_prefix, set);
3408                quote_c_style(other, msg, NULL, 0);
3409                strbuf_addf(msg, "%s\n", reset);
3410                break;
3411        case DIFF_STATUS_MODIFIED:
3412                if (p->score) {
3413                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3414                                    line_prefix,
3415                                    set, similarity_index(p), reset);
3416                        break;
3417                }
3418                /* fallthru */
3419        default:
3420                *must_show_header = 0;
3421        }
3422        if (one && two && oidcmp(&one->oid, &two->oid)) {
3423                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
3424
3425                if (DIFF_OPT_TST(o, BINARY)) {
3426                        mmfile_t mf;
3427                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3428                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3429                                abbrev = 40;
3430                }
3431                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
3432                            diff_abbrev_oid(&one->oid, abbrev),
3433                            diff_abbrev_oid(&two->oid, abbrev));
3434                if (one->mode == two->mode)
3435                        strbuf_addf(msg, " %06o", one->mode);
3436                strbuf_addf(msg, "%s\n", reset);
3437        }
3438}
3439
3440static void run_diff_cmd(const char *pgm,
3441                         const char *name,
3442                         const char *other,
3443                         const char *attr_path,
3444                         struct diff_filespec *one,
3445                         struct diff_filespec *two,
3446                         struct strbuf *msg,
3447                         struct diff_options *o,
3448                         struct diff_filepair *p)
3449{
3450        const char *xfrm_msg = NULL;
3451        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3452        int must_show_header = 0;
3453
3454
3455        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3456                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3457                if (drv && drv->external)
3458                        pgm = drv->external;
3459        }
3460
3461        if (msg) {
3462                /*
3463                 * don't use colors when the header is intended for an
3464                 * external diff driver
3465                 */
3466                fill_metainfo(msg, name, other, one, two, o, p,
3467                              &must_show_header,
3468                              want_color(o->use_color) && !pgm);
3469                xfrm_msg = msg->len ? msg->buf : NULL;
3470        }
3471
3472        if (pgm) {
3473                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3474                                  complete_rewrite, o);
3475                return;
3476        }
3477        if (one && two)
3478                builtin_diff(name, other ? other : name,
3479                             one, two, xfrm_msg, must_show_header,
3480                             o, complete_rewrite);
3481        else
3482                fprintf(o->file, "* Unmerged path %s\n", name);
3483}
3484
3485static void diff_fill_oid_info(struct diff_filespec *one)
3486{
3487        if (DIFF_FILE_VALID(one)) {
3488                if (!one->oid_valid) {
3489                        struct stat st;
3490                        if (one->is_stdin) {
3491                                oidclr(&one->oid);
3492                                return;
3493                        }
3494                        if (lstat(one->path, &st) < 0)
3495                                die_errno("stat '%s'", one->path);
3496                        if (index_path(one->oid.hash, one->path, &st, 0))
3497                                die("cannot hash %s", one->path);
3498                }
3499        }
3500        else
3501                oidclr(&one->oid);
3502}
3503
3504static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3505{
3506        /* Strip the prefix but do not molest /dev/null and absolute paths */
3507        if (*namep && **namep != '/') {
3508                *namep += prefix_length;
3509                if (**namep == '/')
3510                        ++*namep;
3511        }
3512        if (*otherp && **otherp != '/') {
3513                *otherp += prefix_length;
3514                if (**otherp == '/')
3515                        ++*otherp;
3516        }
3517}
3518
3519static void run_diff(struct diff_filepair *p, struct diff_options *o)
3520{
3521        const char *pgm = external_diff();
3522        struct strbuf msg;
3523        struct diff_filespec *one = p->one;
3524        struct diff_filespec *two = p->two;
3525        const char *name;
3526        const char *other;
3527        const char *attr_path;
3528
3529        name  = one->path;
3530        other = (strcmp(name, two->path) ? two->path : NULL);
3531        attr_path = name;
3532        if (o->prefix_length)
3533                strip_prefix(o->prefix_length, &name, &other);
3534
3535        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3536                pgm = NULL;
3537
3538        if (DIFF_PAIR_UNMERGED(p)) {
3539                run_diff_cmd(pgm, name, NULL, attr_path,
3540                             NULL, NULL, NULL, o, p);
3541                return;
3542        }
3543
3544        diff_fill_oid_info(one);
3545        diff_fill_oid_info(two);
3546
3547        if (!pgm &&
3548            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3549            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3550                /*
3551                 * a filepair that changes between file and symlink
3552                 * needs to be split into deletion and creation.
3553                 */
3554                struct diff_filespec *null = alloc_filespec(two->path);
3555                run_diff_cmd(NULL, name, other, attr_path,
3556                             one, null, &msg, o, p);
3557                free(null);
3558                strbuf_release(&msg);
3559
3560                null = alloc_filespec(one->path);
3561                run_diff_cmd(NULL, name, other, attr_path,
3562                             null, two, &msg, o, p);
3563                free(null);
3564        }
3565        else
3566                run_diff_cmd(pgm, name, other, attr_path,
3567                             one, two, &msg, o, p);
3568
3569        strbuf_release(&msg);
3570}
3571
3572static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3573                         struct diffstat_t *diffstat)
3574{
3575        const char *name;
3576        const char *other;
3577
3578        if (DIFF_PAIR_UNMERGED(p)) {
3579                /* unmerged */
3580                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
3581                return;
3582        }
3583
3584        name = p->one->path;
3585        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3586
3587        if (o->prefix_length)
3588                strip_prefix(o->prefix_length, &name, &other);
3589
3590        diff_fill_oid_info(p->one);
3591        diff_fill_oid_info(p->two);
3592
3593        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
3594}
3595
3596static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3597{
3598        const char *name;
3599        const char *other;
3600        const char *attr_path;
3601
3602        if (DIFF_PAIR_UNMERGED(p)) {
3603                /* unmerged */
3604                return;
3605        }
3606
3607        name = p->one->path;
3608        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3609        attr_path = other ? other : name;
3610
3611        if (o->prefix_length)
3612                strip_prefix(o->prefix_length, &name, &other);
3613
3614        diff_fill_oid_info(p->one);
3615        diff_fill_oid_info(p->two);
3616
3617        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3618}
3619
3620void diff_setup(struct diff_options *options)
3621{
3622        memcpy(options, &default_diff_options, sizeof(*options));
3623
3624        options->file = stdout;
3625
3626        options->abbrev = DEFAULT_ABBREV;
3627        options->line_termination = '\n';
3628        options->break_opt = -1;
3629        options->rename_limit = -1;
3630        options->dirstat_permille = diff_dirstat_permille_default;
3631        options->context = diff_context_default;
3632        options->interhunkcontext = diff_interhunk_context_default;
3633        options->ws_error_highlight = ws_error_highlight_default;
3634        DIFF_OPT_SET(options, RENAME_EMPTY);
3635
3636        /* pathchange left =NULL by default */
3637        options->change = diff_change;
3638        options->add_remove = diff_addremove;
3639        options->use_color = diff_use_color_default;
3640        options->detect_rename = diff_detect_rename_default;
3641        options->xdl_opts |= diff_algorithm;
3642        if (diff_indent_heuristic)
3643                DIFF_XDL_SET(options, INDENT_HEURISTIC);
3644
3645        options->orderfile = diff_order_file_cfg;
3646
3647        if (diff_no_prefix) {
3648                options->a_prefix = options->b_prefix = "";
3649        } else if (!diff_mnemonic_prefix) {
3650                options->a_prefix = "a/";
3651                options->b_prefix = "b/";
3652        }
3653}
3654
3655void diff_setup_done(struct diff_options *options)
3656{
3657        int count = 0;
3658
3659        if (options->set_default)
3660                options->set_default(options);
3661
3662        if (options->output_format & DIFF_FORMAT_NAME)
3663                count++;
3664        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3665                count++;
3666        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3667                count++;
3668        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3669                count++;
3670        if (count > 1)
3671                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
3672
3673        /*
3674         * Most of the time we can say "there are changes"
3675         * only by checking if there are changed paths, but
3676         * --ignore-whitespace* options force us to look
3677         * inside contents.
3678         */
3679
3680        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3681            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3682            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3683                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3684        else
3685                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3686
3687        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3688                options->detect_rename = DIFF_DETECT_COPY;
3689
3690        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3691                options->prefix = NULL;
3692        if (options->prefix)
3693                options->prefix_length = strlen(options->prefix);
3694        else
3695                options->prefix_length = 0;
3696
3697        if (options->output_format & (DIFF_FORMAT_NAME |
3698                                      DIFF_FORMAT_NAME_STATUS |
3699                                      DIFF_FORMAT_CHECKDIFF |
3700                                      DIFF_FORMAT_NO_OUTPUT))
3701                options->output_format &= ~(DIFF_FORMAT_RAW |
3702                                            DIFF_FORMAT_NUMSTAT |
3703                                            DIFF_FORMAT_DIFFSTAT |
3704                                            DIFF_FORMAT_SHORTSTAT |
3705                                            DIFF_FORMAT_DIRSTAT |
3706                                            DIFF_FORMAT_SUMMARY |
3707                                            DIFF_FORMAT_PATCH);
3708
3709        /*
3710         * These cases always need recursive; we do not drop caller-supplied
3711         * recursive bits for other formats here.
3712         */
3713        if (options->output_format & (DIFF_FORMAT_PATCH |
3714                                      DIFF_FORMAT_NUMSTAT |
3715                                      DIFF_FORMAT_DIFFSTAT |
3716                                      DIFF_FORMAT_SHORTSTAT |
3717                                      DIFF_FORMAT_DIRSTAT |
3718                                      DIFF_FORMAT_SUMMARY |
3719                                      DIFF_FORMAT_CHECKDIFF))
3720                DIFF_OPT_SET(options, RECURSIVE);
3721        /*
3722         * Also pickaxe would not work very well if you do not say recursive
3723         */
3724        if (options->pickaxe)
3725                DIFF_OPT_SET(options, RECURSIVE);
3726        /*
3727         * When patches are generated, submodules diffed against the work tree
3728         * must be checked for dirtiness too so it can be shown in the output
3729         */
3730        if (options->output_format & DIFF_FORMAT_PATCH)
3731                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3732
3733        if (options->detect_rename && options->rename_limit < 0)
3734                options->rename_limit = diff_rename_limit_default;
3735        if (options->setup & DIFF_SETUP_USE_CACHE) {
3736                if (!active_cache)
3737                        /* read-cache does not die even when it fails
3738                         * so it is safe for us to do this here.  Also
3739                         * it does not smudge active_cache or active_nr
3740                         * when it fails, so we do not have to worry about
3741                         * cleaning it up ourselves either.
3742                         */
3743                        read_cache();
3744        }
3745        if (40 < options->abbrev)
3746                options->abbrev = 40; /* full */
3747
3748        /*
3749         * It does not make sense to show the first hit we happened
3750         * to have found.  It does not make sense not to return with
3751         * exit code in such a case either.
3752         */
3753        if (DIFF_OPT_TST(options, QUICK)) {
3754                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3755                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3756        }
3757
3758        options->diff_path_counter = 0;
3759
3760        if (DIFF_OPT_TST(options, FOLLOW_RENAMES) && options->pathspec.nr != 1)
3761                die(_("--follow requires exactly one pathspec"));
3762}
3763
3764static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3765{
3766        char c, *eq;
3767        int len;
3768
3769        if (*arg != '-')
3770                return 0;
3771        c = *++arg;
3772        if (!c)
3773                return 0;
3774        if (c == arg_short) {
3775                c = *++arg;
3776                if (!c)
3777                        return 1;
3778                if (val && isdigit(c)) {
3779                        char *end;
3780                        int n = strtoul(arg, &end, 10);
3781                        if (*end)
3782                                return 0;
3783                        *val = n;
3784                        return 1;
3785                }
3786                return 0;
3787        }
3788        if (c != '-')
3789                return 0;
3790        arg++;
3791        eq = strchrnul(arg, '=');
3792        len = eq - arg;
3793        if (!len || strncmp(arg, arg_long, len))
3794                return 0;
3795        if (*eq) {
3796                int n;
3797                char *end;
3798                if (!isdigit(*++eq))
3799                        return 0;
3800                n = strtoul(eq, &end, 10);
3801                if (*end)
3802                        return 0;
3803                *val = n;
3804        }
3805        return 1;
3806}
3807
3808static int diff_scoreopt_parse(const char *opt);
3809
3810static inline int short_opt(char opt, const char **argv,
3811                            const char **optarg)
3812{
3813        const char *arg = argv[0];
3814        if (arg[0] != '-' || arg[1] != opt)
3815                return 0;
3816        if (arg[2] != '\0') {
3817                *optarg = arg + 2;
3818                return 1;
3819        }
3820        if (!argv[1])
3821                die("Option '%c' requires a value", opt);
3822        *optarg = argv[1];
3823        return 2;
3824}
3825
3826int parse_long_opt(const char *opt, const char **argv,
3827                   const char **optarg)
3828{
3829        const char *arg = argv[0];
3830        if (!skip_prefix(arg, "--", &arg))
3831                return 0;
3832        if (!skip_prefix(arg, opt, &arg))
3833                return 0;
3834        if (*arg == '=') { /* stuck form: --option=value */
3835                *optarg = arg + 1;
3836                return 1;
3837        }
3838        if (*arg != '\0')
3839                return 0;
3840        /* separate form: --option value */
3841        if (!argv[1])
3842                die("Option '--%s' requires a value", opt);
3843        *optarg = argv[1];
3844        return 2;
3845}
3846
3847static int stat_opt(struct diff_options *options, const char **av)
3848{
3849        const char *arg = av[0];
3850        char *end;
3851        int width = options->stat_width;
3852        int name_width = options->stat_name_width;
3853        int graph_width = options->stat_graph_width;
3854        int count = options->stat_count;
3855        int argcount = 1;
3856
3857        if (!skip_prefix(arg, "--stat", &arg))
3858                die("BUG: stat option does not begin with --stat: %s", arg);
3859        end = (char *)arg;
3860
3861        switch (*arg) {
3862        case '-':
3863                if (skip_prefix(arg, "-width", &arg)) {
3864                        if (*arg == '=')
3865                                width = strtoul(arg + 1, &end, 10);
3866                        else if (!*arg && !av[1])
3867                                die_want_option("--stat-width");
3868                        else if (!*arg) {
3869                                width = strtoul(av[1], &end, 10);
3870                                argcount = 2;
3871                        }
3872                } else if (skip_prefix(arg, "-name-width", &arg)) {
3873                        if (*arg == '=')
3874                                name_width = strtoul(arg + 1, &end, 10);
3875                        else if (!*arg && !av[1])
3876                                die_want_option("--stat-name-width");
3877                        else if (!*arg) {
3878                                name_width = strtoul(av[1], &end, 10);
3879                                argcount = 2;
3880                        }
3881                } else if (skip_prefix(arg, "-graph-width", &arg)) {
3882                        if (*arg == '=')
3883                                graph_width = strtoul(arg + 1, &end, 10);
3884                        else if (!*arg && !av[1])
3885                                die_want_option("--stat-graph-width");
3886                        else if (!*arg) {
3887                                graph_width = strtoul(av[1], &end, 10);
3888                                argcount = 2;
3889                        }
3890                } else if (skip_prefix(arg, "-count", &arg)) {
3891                        if (*arg == '=')
3892                                count = strtoul(arg + 1, &end, 10);
3893                        else if (!*arg && !av[1])
3894                                die_want_option("--stat-count");
3895                        else if (!*arg) {
3896                                count = strtoul(av[1], &end, 10);
3897                                argcount = 2;
3898                        }
3899                }
3900                break;
3901        case '=':
3902                width = strtoul(arg+1, &end, 10);
3903                if (*end == ',')
3904                        name_width = strtoul(end+1, &end, 10);
3905                if (*end == ',')
3906                        count = strtoul(end+1, &end, 10);
3907        }
3908
3909        /* Important! This checks all the error cases! */
3910        if (*end)
3911                return 0;
3912        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3913        options->stat_name_width = name_width;
3914        options->stat_graph_width = graph_width;
3915        options->stat_width = width;
3916        options->stat_count = count;
3917        return argcount;
3918}
3919
3920static int parse_dirstat_opt(struct diff_options *options, const char *params)
3921{
3922        struct strbuf errmsg = STRBUF_INIT;
3923        if (parse_dirstat_params(options, params, &errmsg))
3924                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3925                    errmsg.buf);
3926        strbuf_release(&errmsg);
3927        /*
3928         * The caller knows a dirstat-related option is given from the command
3929         * line; allow it to say "return this_function();"
3930         */
3931        options->output_format |= DIFF_FORMAT_DIRSTAT;
3932        return 1;
3933}
3934
3935static int parse_submodule_opt(struct diff_options *options, const char *value)
3936{
3937        if (parse_submodule_params(options, value))
3938                die(_("Failed to parse --submodule option parameter: '%s'"),
3939                        value);
3940        return 1;
3941}
3942
3943static const char diff_status_letters[] = {
3944        DIFF_STATUS_ADDED,
3945        DIFF_STATUS_COPIED,
3946        DIFF_STATUS_DELETED,
3947        DIFF_STATUS_MODIFIED,
3948        DIFF_STATUS_RENAMED,
3949        DIFF_STATUS_TYPE_CHANGED,
3950        DIFF_STATUS_UNKNOWN,
3951        DIFF_STATUS_UNMERGED,
3952        DIFF_STATUS_FILTER_AON,
3953        DIFF_STATUS_FILTER_BROKEN,
3954        '\0',
3955};
3956
3957static unsigned int filter_bit['Z' + 1];
3958
3959static void prepare_filter_bits(void)
3960{
3961        int i;
3962
3963        if (!filter_bit[DIFF_STATUS_ADDED]) {
3964                for (i = 0; diff_status_letters[i]; i++)
3965                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
3966        }
3967}
3968
3969static unsigned filter_bit_tst(char status, const struct diff_options *opt)
3970{
3971        return opt->filter & filter_bit[(int) status];
3972}
3973
3974static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
3975{
3976        int i, optch;
3977
3978        prepare_filter_bits();
3979
3980        /*
3981         * If there is a negation e.g. 'd' in the input, and we haven't
3982         * initialized the filter field with another --diff-filter, start
3983         * from full set of bits, except for AON.
3984         */
3985        if (!opt->filter) {
3986                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3987                        if (optch < 'a' || 'z' < optch)
3988                                continue;
3989                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
3990                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
3991                        break;
3992                }
3993        }
3994
3995        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3996                unsigned int bit;
3997                int negate;
3998
3999                if ('a' <= optch && optch <= 'z') {
4000                        negate = 1;
4001                        optch = toupper(optch);
4002                } else {
4003                        negate = 0;
4004                }
4005
4006                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4007                if (!bit)
4008                        return optarg[i];
4009                if (negate)
4010                        opt->filter &= ~bit;
4011                else
4012                        opt->filter |= bit;
4013        }
4014        return 0;
4015}
4016
4017static void enable_patch_output(int *fmt) {
4018        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4019        *fmt |= DIFF_FORMAT_PATCH;
4020}
4021
4022static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4023{
4024        int val = parse_ws_error_highlight(arg);
4025
4026        if (val < 0) {
4027                error("unknown value after ws-error-highlight=%.*s",
4028                      -1 - val, arg);
4029                return 0;
4030        }
4031        opt->ws_error_highlight = val;
4032        return 1;
4033}
4034
4035int diff_opt_parse(struct diff_options *options,
4036                   const char **av, int ac, const char *prefix)
4037{
4038        const char *arg = av[0];
4039        const char *optarg;
4040        int argcount;
4041
4042        if (!prefix)
4043                prefix = "";
4044
4045        /* Output format options */
4046        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4047            || opt_arg(arg, 'U', "unified", &options->context))
4048                enable_patch_output(&options->output_format);
4049        else if (!strcmp(arg, "--raw"))
4050                options->output_format |= DIFF_FORMAT_RAW;
4051        else if (!strcmp(arg, "--patch-with-raw")) {
4052                enable_patch_output(&options->output_format);
4053                options->output_format |= DIFF_FORMAT_RAW;
4054        } else if (!strcmp(arg, "--numstat"))
4055                options->output_format |= DIFF_FORMAT_NUMSTAT;
4056        else if (!strcmp(arg, "--shortstat"))
4057                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4058        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
4059                return parse_dirstat_opt(options, "");
4060        else if (skip_prefix(arg, "-X", &arg))
4061                return parse_dirstat_opt(options, arg);
4062        else if (skip_prefix(arg, "--dirstat=", &arg))
4063                return parse_dirstat_opt(options, arg);
4064        else if (!strcmp(arg, "--cumulative"))
4065                return parse_dirstat_opt(options, "cumulative");
4066        else if (!strcmp(arg, "--dirstat-by-file"))
4067                return parse_dirstat_opt(options, "files");
4068        else if (skip_prefix(arg, "--dirstat-by-file=", &arg)) {
4069                parse_dirstat_opt(options, "files");
4070                return parse_dirstat_opt(options, arg);
4071        }
4072        else if (!strcmp(arg, "--check"))
4073                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4074        else if (!strcmp(arg, "--summary"))
4075                options->output_format |= DIFF_FORMAT_SUMMARY;
4076        else if (!strcmp(arg, "--patch-with-stat")) {
4077                enable_patch_output(&options->output_format);
4078                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4079        } else if (!strcmp(arg, "--name-only"))
4080                options->output_format |= DIFF_FORMAT_NAME;
4081        else if (!strcmp(arg, "--name-status"))
4082                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4083        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4084                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4085        else if (starts_with(arg, "--stat"))
4086                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4087                return stat_opt(options, av);
4088
4089        /* renames options */
4090        else if (starts_with(arg, "-B") || starts_with(arg, "--break-rewrites=") ||
4091                 !strcmp(arg, "--break-rewrites")) {
4092                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4093                        return error("invalid argument to -B: %s", arg+2);
4094        }
4095        else if (starts_with(arg, "-M") || starts_with(arg, "--find-renames=") ||
4096                 !strcmp(arg, "--find-renames")) {
4097                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4098                        return error("invalid argument to -M: %s", arg+2);
4099                options->detect_rename = DIFF_DETECT_RENAME;
4100        }
4101        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4102                options->irreversible_delete = 1;
4103        }
4104        else if (starts_with(arg, "-C") || starts_with(arg, "--find-copies=") ||
4105                 !strcmp(arg, "--find-copies")) {
4106                if (options->detect_rename == DIFF_DETECT_COPY)
4107                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
4108                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4109                        return error("invalid argument to -C: %s", arg+2);
4110                options->detect_rename = DIFF_DETECT_COPY;
4111        }
4112        else if (!strcmp(arg, "--no-renames"))
4113                options->detect_rename = 0;
4114        else if (!strcmp(arg, "--rename-empty"))
4115                DIFF_OPT_SET(options, RENAME_EMPTY);
4116        else if (!strcmp(arg, "--no-rename-empty"))
4117                DIFF_OPT_CLR(options, RENAME_EMPTY);
4118        else if (!strcmp(arg, "--relative"))
4119                DIFF_OPT_SET(options, RELATIVE_NAME);
4120        else if (skip_prefix(arg, "--relative=", &arg)) {
4121                DIFF_OPT_SET(options, RELATIVE_NAME);
4122                options->prefix = arg;
4123        }
4124
4125        /* xdiff options */
4126        else if (!strcmp(arg, "--minimal"))
4127                DIFF_XDL_SET(options, NEED_MINIMAL);
4128        else if (!strcmp(arg, "--no-minimal"))
4129                DIFF_XDL_CLR(options, NEED_MINIMAL);
4130        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4131                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4132        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4133                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4134        else if (!strcmp(arg, "--ignore-space-at-eol"))
4135                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4136        else if (!strcmp(arg, "--ignore-blank-lines"))
4137                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4138        else if (!strcmp(arg, "--indent-heuristic"))
4139                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4140        else if (!strcmp(arg, "--no-indent-heuristic"))
4141                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4142        else if (!strcmp(arg, "--patience"))
4143                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4144        else if (!strcmp(arg, "--histogram"))
4145                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4146        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4147                long value = parse_algorithm_value(optarg);
4148                if (value < 0)
4149                        return error("option diff-algorithm accepts \"myers\", "
4150                                     "\"minimal\", \"patience\" and \"histogram\"");
4151                /* clear out previous settings */
4152                DIFF_XDL_CLR(options, NEED_MINIMAL);
4153                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4154                options->xdl_opts |= value;
4155                return argcount;
4156        }
4157
4158        /* flags options */
4159        else if (!strcmp(arg, "--binary")) {
4160                enable_patch_output(&options->output_format);
4161                DIFF_OPT_SET(options, BINARY);
4162        }
4163        else if (!strcmp(arg, "--full-index"))
4164                DIFF_OPT_SET(options, FULL_INDEX);
4165        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4166                DIFF_OPT_SET(options, TEXT);
4167        else if (!strcmp(arg, "-R"))
4168                DIFF_OPT_SET(options, REVERSE_DIFF);
4169        else if (!strcmp(arg, "--find-copies-harder"))
4170                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
4171        else if (!strcmp(arg, "--follow"))
4172                DIFF_OPT_SET(options, FOLLOW_RENAMES);
4173        else if (!strcmp(arg, "--no-follow")) {
4174                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
4175                DIFF_OPT_CLR(options, DEFAULT_FOLLOW_RENAMES);
4176        } else if (!strcmp(arg, "--color"))
4177                options->use_color = 1;
4178        else if (skip_prefix(arg, "--color=", &arg)) {
4179                int value = git_config_colorbool(NULL, arg);
4180                if (value < 0)
4181                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4182                options->use_color = value;
4183        }
4184        else if (!strcmp(arg, "--no-color"))
4185                options->use_color = 0;
4186        else if (!strcmp(arg, "--color-words")) {
4187                options->use_color = 1;
4188                options->word_diff = DIFF_WORDS_COLOR;
4189        }
4190        else if (skip_prefix(arg, "--color-words=", &arg)) {
4191                options->use_color = 1;
4192                options->word_diff = DIFF_WORDS_COLOR;
4193                options->word_regex = arg;
4194        }
4195        else if (!strcmp(arg, "--word-diff")) {
4196                if (options->word_diff == DIFF_WORDS_NONE)
4197                        options->word_diff = DIFF_WORDS_PLAIN;
4198        }
4199        else if (skip_prefix(arg, "--word-diff=", &arg)) {
4200                if (!strcmp(arg, "plain"))
4201                        options->word_diff = DIFF_WORDS_PLAIN;
4202                else if (!strcmp(arg, "color")) {
4203                        options->use_color = 1;
4204                        options->word_diff = DIFF_WORDS_COLOR;
4205                }
4206                else if (!strcmp(arg, "porcelain"))
4207                        options->word_diff = DIFF_WORDS_PORCELAIN;
4208                else if (!strcmp(arg, "none"))
4209                        options->word_diff = DIFF_WORDS_NONE;
4210                else
4211                        die("bad --word-diff argument: %s", arg);
4212        }
4213        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
4214                if (options->word_diff == DIFF_WORDS_NONE)
4215                        options->word_diff = DIFF_WORDS_PLAIN;
4216                options->word_regex = optarg;
4217                return argcount;
4218        }
4219        else if (!strcmp(arg, "--exit-code"))
4220                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
4221        else if (!strcmp(arg, "--quiet"))
4222                DIFF_OPT_SET(options, QUICK);
4223        else if (!strcmp(arg, "--ext-diff"))
4224                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
4225        else if (!strcmp(arg, "--no-ext-diff"))
4226                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
4227        else if (!strcmp(arg, "--textconv"))
4228                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
4229        else if (!strcmp(arg, "--no-textconv"))
4230                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
4231        else if (!strcmp(arg, "--ignore-submodules")) {
4232                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
4233                handle_ignore_submodules_arg(options, "all");
4234        } else if (skip_prefix(arg, "--ignore-submodules=", &arg)) {
4235                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
4236                handle_ignore_submodules_arg(options, arg);
4237        } else if (!strcmp(arg, "--submodule"))
4238                options->submodule_format = DIFF_SUBMODULE_LOG;
4239        else if (skip_prefix(arg, "--submodule=", &arg))
4240                return parse_submodule_opt(options, arg);
4241        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
4242                return parse_ws_error_highlight_opt(options, arg);
4243        else if (!strcmp(arg, "--ita-invisible-in-index"))
4244                options->ita_invisible_in_index = 1;
4245        else if (!strcmp(arg, "--ita-visible-in-index"))
4246                options->ita_invisible_in_index = 0;
4247
4248        /* misc options */
4249        else if (!strcmp(arg, "-z"))
4250                options->line_termination = 0;
4251        else if ((argcount = short_opt('l', av, &optarg))) {
4252                options->rename_limit = strtoul(optarg, NULL, 10);
4253                return argcount;
4254        }
4255        else if ((argcount = short_opt('S', av, &optarg))) {
4256                options->pickaxe = optarg;
4257                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
4258                return argcount;
4259        } else if ((argcount = short_opt('G', av, &optarg))) {
4260                options->pickaxe = optarg;
4261                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
4262                return argcount;
4263        }
4264        else if (!strcmp(arg, "--pickaxe-all"))
4265                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
4266        else if (!strcmp(arg, "--pickaxe-regex"))
4267                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
4268        else if ((argcount = short_opt('O', av, &optarg))) {
4269                options->orderfile = prefix_filename(prefix, optarg);
4270                return argcount;
4271        }
4272        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
4273                int offending = parse_diff_filter_opt(optarg, options);
4274                if (offending)
4275                        die("unknown change class '%c' in --diff-filter=%s",
4276                            offending, optarg);
4277                return argcount;
4278        }
4279        else if (!strcmp(arg, "--no-abbrev"))
4280                options->abbrev = 0;
4281        else if (!strcmp(arg, "--abbrev"))
4282                options->abbrev = DEFAULT_ABBREV;
4283        else if (skip_prefix(arg, "--abbrev=", &arg)) {
4284                options->abbrev = strtoul(arg, NULL, 10);
4285                if (options->abbrev < MINIMUM_ABBREV)
4286                        options->abbrev = MINIMUM_ABBREV;
4287                else if (40 < options->abbrev)
4288                        options->abbrev = 40;
4289        }
4290        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
4291                options->a_prefix = optarg;
4292                return argcount;
4293        }
4294        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
4295                options->line_prefix = optarg;
4296                options->line_prefix_length = strlen(options->line_prefix);
4297                graph_setup_line_prefix(options);
4298                return argcount;
4299        }
4300        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
4301                options->b_prefix = optarg;
4302                return argcount;
4303        }
4304        else if (!strcmp(arg, "--no-prefix"))
4305                options->a_prefix = options->b_prefix = "";
4306        else if (opt_arg(arg, '\0', "inter-hunk-context",
4307                         &options->interhunkcontext))
4308                ;
4309        else if (!strcmp(arg, "-W"))
4310                DIFF_OPT_SET(options, FUNCCONTEXT);
4311        else if (!strcmp(arg, "--function-context"))
4312                DIFF_OPT_SET(options, FUNCCONTEXT);
4313        else if (!strcmp(arg, "--no-function-context"))
4314                DIFF_OPT_CLR(options, FUNCCONTEXT);
4315        else if ((argcount = parse_long_opt("output", av, &optarg))) {
4316                char *path = prefix_filename(prefix, optarg);
4317                options->file = xfopen(path, "w");
4318                options->close_file = 1;
4319                if (options->use_color != GIT_COLOR_ALWAYS)
4320                        options->use_color = GIT_COLOR_NEVER;
4321                free(path);
4322                return argcount;
4323        } else
4324                return 0;
4325        return 1;
4326}
4327
4328int parse_rename_score(const char **cp_p)
4329{
4330        unsigned long num, scale;
4331        int ch, dot;
4332        const char *cp = *cp_p;
4333
4334        num = 0;
4335        scale = 1;
4336        dot = 0;
4337        for (;;) {
4338                ch = *cp;
4339                if ( !dot && ch == '.' ) {
4340                        scale = 1;
4341                        dot = 1;
4342                } else if ( ch == '%' ) {
4343                        scale = dot ? scale*100 : 100;
4344                        cp++;   /* % is always at the end */
4345                        break;
4346                } else if ( ch >= '0' && ch <= '9' ) {
4347                        if ( scale < 100000 ) {
4348                                scale *= 10;
4349                                num = (num*10) + (ch-'0');
4350                        }
4351                } else {
4352                        break;
4353                }
4354                cp++;
4355        }
4356        *cp_p = cp;
4357
4358        /* user says num divided by scale and we say internally that
4359         * is MAX_SCORE * num / scale.
4360         */
4361        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
4362}
4363
4364static int diff_scoreopt_parse(const char *opt)
4365{
4366        int opt1, opt2, cmd;
4367
4368        if (*opt++ != '-')
4369                return -1;
4370        cmd = *opt++;
4371        if (cmd == '-') {
4372                /* convert the long-form arguments into short-form versions */
4373                if (skip_prefix(opt, "break-rewrites", &opt)) {
4374                        if (*opt == 0 || *opt++ == '=')
4375                                cmd = 'B';
4376                } else if (skip_prefix(opt, "find-copies", &opt)) {
4377                        if (*opt == 0 || *opt++ == '=')
4378                                cmd = 'C';
4379                } else if (skip_prefix(opt, "find-renames", &opt)) {
4380                        if (*opt == 0 || *opt++ == '=')
4381                                cmd = 'M';
4382                }
4383        }
4384        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
4385                return -1; /* that is not a -M, -C, or -B option */
4386
4387        opt1 = parse_rename_score(&opt);
4388        if (cmd != 'B')
4389                opt2 = 0;
4390        else {
4391                if (*opt == 0)
4392                        opt2 = 0;
4393                else if (*opt != '/')
4394                        return -1; /* we expect -B80/99 or -B80 */
4395                else {
4396                        opt++;
4397                        opt2 = parse_rename_score(&opt);
4398                }
4399        }
4400        if (*opt != 0)
4401                return -1;
4402        return opt1 | (opt2 << 16);
4403}
4404
4405struct diff_queue_struct diff_queued_diff;
4406
4407void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
4408{
4409        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
4410        queue->queue[queue->nr++] = dp;
4411}
4412
4413struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
4414                                 struct diff_filespec *one,
4415                                 struct diff_filespec *two)
4416{
4417        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
4418        dp->one = one;
4419        dp->two = two;
4420        if (queue)
4421                diff_q(queue, dp);
4422        return dp;
4423}
4424
4425void diff_free_filepair(struct diff_filepair *p)
4426{
4427        free_filespec(p->one);
4428        free_filespec(p->two);
4429        free(p);
4430}
4431
4432const char *diff_aligned_abbrev(const struct object_id *oid, int len)
4433{
4434        int abblen;
4435        const char *abbrev;
4436
4437        if (len == GIT_SHA1_HEXSZ)
4438                return oid_to_hex(oid);
4439
4440        abbrev = diff_abbrev_oid(oid, len);
4441        abblen = strlen(abbrev);
4442
4443        /*
4444         * In well-behaved cases, where the abbbreviated result is the
4445         * same as the requested length, append three dots after the
4446         * abbreviation (hence the whole logic is limited to the case
4447         * where abblen < 37); when the actual abbreviated result is a
4448         * bit longer than the requested length, we reduce the number
4449         * of dots so that they match the well-behaved ones.  However,
4450         * if the actual abbreviation is longer than the requested
4451         * length by more than three, we give up on aligning, and add
4452         * three dots anyway, to indicate that the output is not the
4453         * full object name.  Yes, this may be suboptimal, but this
4454         * appears only in "diff --raw --abbrev" output and it is not
4455         * worth the effort to change it now.  Note that this would
4456         * likely to work fine when the automatic sizing of default
4457         * abbreviation length is used--we would be fed -1 in "len" in
4458         * that case, and will end up always appending three-dots, but
4459         * the automatic sizing is supposed to give abblen that ensures
4460         * uniqueness across all objects (statistically speaking).
4461         */
4462        if (abblen < GIT_SHA1_HEXSZ - 3) {
4463                static char hex[GIT_MAX_HEXSZ + 1];
4464                if (len < abblen && abblen <= len + 2)
4465                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
4466                else
4467                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
4468                return hex;
4469        }
4470
4471        return oid_to_hex(oid);
4472}
4473
4474static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4475{
4476        int line_termination = opt->line_termination;
4477        int inter_name_termination = line_termination ? '\t' : '\0';
4478
4479        fprintf(opt->file, "%s", diff_line_prefix(opt));
4480        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
4481                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
4482                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
4483                fprintf(opt->file, "%s ",
4484                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
4485        }
4486        if (p->score) {
4487                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
4488                        inter_name_termination);
4489        } else {
4490                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
4491        }
4492
4493        if (p->status == DIFF_STATUS_COPIED ||
4494            p->status == DIFF_STATUS_RENAMED) {
4495                const char *name_a, *name_b;
4496                name_a = p->one->path;
4497                name_b = p->two->path;
4498                strip_prefix(opt->prefix_length, &name_a, &name_b);
4499                write_name_quoted(name_a, opt->file, inter_name_termination);
4500                write_name_quoted(name_b, opt->file, line_termination);
4501        } else {
4502                const char *name_a, *name_b;
4503                name_a = p->one->mode ? p->one->path : p->two->path;
4504                name_b = NULL;
4505                strip_prefix(opt->prefix_length, &name_a, &name_b);
4506                write_name_quoted(name_a, opt->file, line_termination);
4507        }
4508}
4509
4510int diff_unmodified_pair(struct diff_filepair *p)
4511{
4512        /* This function is written stricter than necessary to support
4513         * the currently implemented transformers, but the idea is to
4514         * let transformers to produce diff_filepairs any way they want,
4515         * and filter and clean them up here before producing the output.
4516         */
4517        struct diff_filespec *one = p->one, *two = p->two;
4518
4519        if (DIFF_PAIR_UNMERGED(p))
4520                return 0; /* unmerged is interesting */
4521
4522        /* deletion, addition, mode or type change
4523         * and rename are all interesting.
4524         */
4525        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
4526            DIFF_PAIR_MODE_CHANGED(p) ||
4527            strcmp(one->path, two->path))
4528                return 0;
4529
4530        /* both are valid and point at the same path.  that is, we are
4531         * dealing with a change.
4532         */
4533        if (one->oid_valid && two->oid_valid &&
4534            !oidcmp(&one->oid, &two->oid) &&
4535            !one->dirty_submodule && !two->dirty_submodule)
4536                return 1; /* no change */
4537        if (!one->oid_valid && !two->oid_valid)
4538                return 1; /* both look at the same file on the filesystem. */
4539        return 0;
4540}
4541
4542static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
4543{
4544        if (diff_unmodified_pair(p))
4545                return;
4546
4547        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4548            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4549                return; /* no tree diffs in patch format */
4550
4551        run_diff(p, o);
4552}
4553
4554static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
4555                            struct diffstat_t *diffstat)
4556{
4557        if (diff_unmodified_pair(p))
4558                return;
4559
4560        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4561            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4562                return; /* no useful stat for tree diffs */
4563
4564        run_diffstat(p, o, diffstat);
4565}
4566
4567static void diff_flush_checkdiff(struct diff_filepair *p,
4568                struct diff_options *o)
4569{
4570        if (diff_unmodified_pair(p))
4571                return;
4572
4573        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4574            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4575                return; /* nothing to check in tree diffs */
4576
4577        run_checkdiff(p, o);
4578}
4579
4580int diff_queue_is_empty(void)
4581{
4582        struct diff_queue_struct *q = &diff_queued_diff;
4583        int i;
4584        for (i = 0; i < q->nr; i++)
4585                if (!diff_unmodified_pair(q->queue[i]))
4586                        return 0;
4587        return 1;
4588}
4589
4590#if DIFF_DEBUG
4591void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
4592{
4593        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
4594                x, one ? one : "",
4595                s->path,
4596                DIFF_FILE_VALID(s) ? "valid" : "invalid",
4597                s->mode,
4598                s->oid_valid ? oid_to_hex(&s->oid) : "");
4599        fprintf(stderr, "queue[%d] %s size %lu\n",
4600                x, one ? one : "",
4601                s->size);
4602}
4603
4604void diff_debug_filepair(const struct diff_filepair *p, int i)
4605{
4606        diff_debug_filespec(p->one, i, "one");
4607        diff_debug_filespec(p->two, i, "two");
4608        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4609                p->score, p->status ? p->status : '?',
4610                p->one->rename_used, p->broken_pair);
4611}
4612
4613void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4614{
4615        int i;
4616        if (msg)
4617                fprintf(stderr, "%s\n", msg);
4618        fprintf(stderr, "q->nr = %d\n", q->nr);
4619        for (i = 0; i < q->nr; i++) {
4620                struct diff_filepair *p = q->queue[i];
4621                diff_debug_filepair(p, i);
4622        }
4623}
4624#endif
4625
4626static void diff_resolve_rename_copy(void)
4627{
4628        int i;
4629        struct diff_filepair *p;
4630        struct diff_queue_struct *q = &diff_queued_diff;
4631
4632        diff_debug_queue("resolve-rename-copy", q);
4633
4634        for (i = 0; i < q->nr; i++) {
4635                p = q->queue[i];
4636                p->status = 0; /* undecided */
4637                if (DIFF_PAIR_UNMERGED(p))
4638                        p->status = DIFF_STATUS_UNMERGED;
4639                else if (!DIFF_FILE_VALID(p->one))
4640                        p->status = DIFF_STATUS_ADDED;
4641                else if (!DIFF_FILE_VALID(p->two))
4642                        p->status = DIFF_STATUS_DELETED;
4643                else if (DIFF_PAIR_TYPE_CHANGED(p))
4644                        p->status = DIFF_STATUS_TYPE_CHANGED;
4645
4646                /* from this point on, we are dealing with a pair
4647                 * whose both sides are valid and of the same type, i.e.
4648                 * either in-place edit or rename/copy edit.
4649                 */
4650                else if (DIFF_PAIR_RENAME(p)) {
4651                        /*
4652                         * A rename might have re-connected a broken
4653                         * pair up, causing the pathnames to be the
4654                         * same again. If so, that's not a rename at
4655                         * all, just a modification..
4656                         *
4657                         * Otherwise, see if this source was used for
4658                         * multiple renames, in which case we decrement
4659                         * the count, and call it a copy.
4660                         */
4661                        if (!strcmp(p->one->path, p->two->path))
4662                                p->status = DIFF_STATUS_MODIFIED;
4663                        else if (--p->one->rename_used > 0)
4664                                p->status = DIFF_STATUS_COPIED;
4665                        else
4666                                p->status = DIFF_STATUS_RENAMED;
4667                }
4668                else if (oidcmp(&p->one->oid, &p->two->oid) ||
4669                         p->one->mode != p->two->mode ||
4670                         p->one->dirty_submodule ||
4671                         p->two->dirty_submodule ||
4672                         is_null_oid(&p->one->oid))
4673                        p->status = DIFF_STATUS_MODIFIED;
4674                else {
4675                        /* This is a "no-change" entry and should not
4676                         * happen anymore, but prepare for broken callers.
4677                         */
4678                        error("feeding unmodified %s to diffcore",
4679                              p->one->path);
4680                        p->status = DIFF_STATUS_UNKNOWN;
4681                }
4682        }
4683        diff_debug_queue("resolve-rename-copy done", q);
4684}
4685
4686static int check_pair_status(struct diff_filepair *p)
4687{
4688        switch (p->status) {
4689        case DIFF_STATUS_UNKNOWN:
4690                return 0;
4691        case 0:
4692                die("internal error in diff-resolve-rename-copy");
4693        default:
4694                return 1;
4695        }
4696}
4697
4698static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4699{
4700        int fmt = opt->output_format;
4701
4702        if (fmt & DIFF_FORMAT_CHECKDIFF)
4703                diff_flush_checkdiff(p, opt);
4704        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4705                diff_flush_raw(p, opt);
4706        else if (fmt & DIFF_FORMAT_NAME) {
4707                const char *name_a, *name_b;
4708                name_a = p->two->path;
4709                name_b = NULL;
4710                strip_prefix(opt->prefix_length, &name_a, &name_b);
4711                fprintf(opt->file, "%s", diff_line_prefix(opt));
4712                write_name_quoted(name_a, opt->file, opt->line_termination);
4713        }
4714}
4715
4716static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4717{
4718        if (fs->mode)
4719                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4720        else
4721                fprintf(file, " %s ", newdelete);
4722        write_name_quoted(fs->path, file, '\n');
4723}
4724
4725
4726static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4727                const char *line_prefix)
4728{
4729        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4730                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4731                        p->two->mode, show_name ? ' ' : '\n');
4732                if (show_name) {
4733                        write_name_quoted(p->two->path, file, '\n');
4734                }
4735        }
4736}
4737
4738static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4739                        const char *line_prefix)
4740{
4741        char *names = pprint_rename(p->one->path, p->two->path);
4742
4743        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4744        free(names);
4745        show_mode_change(file, p, 0, line_prefix);
4746}
4747
4748static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4749{
4750        FILE *file = opt->file;
4751        const char *line_prefix = diff_line_prefix(opt);
4752
4753        switch(p->status) {
4754        case DIFF_STATUS_DELETED:
4755                fputs(line_prefix, file);
4756                show_file_mode_name(file, "delete", p->one);
4757                break;
4758        case DIFF_STATUS_ADDED:
4759                fputs(line_prefix, file);
4760                show_file_mode_name(file, "create", p->two);
4761                break;
4762        case DIFF_STATUS_COPIED:
4763                fputs(line_prefix, file);
4764                show_rename_copy(file, "copy", p, line_prefix);
4765                break;
4766        case DIFF_STATUS_RENAMED:
4767                fputs(line_prefix, file);
4768                show_rename_copy(file, "rename", p, line_prefix);
4769                break;
4770        default:
4771                if (p->score) {
4772                        fprintf(file, "%s rewrite ", line_prefix);
4773                        write_name_quoted(p->two->path, file, ' ');
4774                        fprintf(file, "(%d%%)\n", similarity_index(p));
4775                }
4776                show_mode_change(file, p, !p->score, line_prefix);
4777                break;
4778        }
4779}
4780
4781struct patch_id_t {
4782        git_SHA_CTX *ctx;
4783        int patchlen;
4784};
4785
4786static int remove_space(char *line, int len)
4787{
4788        int i;
4789        char *dst = line;
4790        unsigned char c;
4791
4792        for (i = 0; i < len; i++)
4793                if (!isspace((c = line[i])))
4794                        *dst++ = c;
4795
4796        return dst - line;
4797}
4798
4799static void patch_id_consume(void *priv, char *line, unsigned long len)
4800{
4801        struct patch_id_t *data = priv;
4802        int new_len;
4803
4804        /* Ignore line numbers when computing the SHA1 of the patch */
4805        if (starts_with(line, "@@ -"))
4806                return;
4807
4808        new_len = remove_space(line, len);
4809
4810        git_SHA1_Update(data->ctx, line, new_len);
4811        data->patchlen += new_len;
4812}
4813
4814static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
4815{
4816        git_SHA1_Update(ctx, str, strlen(str));
4817}
4818
4819static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
4820{
4821        /* large enough for 2^32 in octal */
4822        char buf[12];
4823        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
4824        git_SHA1_Update(ctx, buf, len);
4825}
4826
4827/* returns 0 upon success, and writes result into sha1 */
4828static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
4829{
4830        struct diff_queue_struct *q = &diff_queued_diff;
4831        int i;
4832        git_SHA_CTX ctx;
4833        struct patch_id_t data;
4834
4835        git_SHA1_Init(&ctx);
4836        memset(&data, 0, sizeof(struct patch_id_t));
4837        data.ctx = &ctx;
4838
4839        for (i = 0; i < q->nr; i++) {
4840                xpparam_t xpp;
4841                xdemitconf_t xecfg;
4842                mmfile_t mf1, mf2;
4843                struct diff_filepair *p = q->queue[i];
4844                int len1, len2;
4845
4846                memset(&xpp, 0, sizeof(xpp));
4847                memset(&xecfg, 0, sizeof(xecfg));
4848                if (p->status == 0)
4849                        return error("internal diff status error");
4850                if (p->status == DIFF_STATUS_UNKNOWN)
4851                        continue;
4852                if (diff_unmodified_pair(p))
4853                        continue;
4854                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4855                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4856                        continue;
4857                if (DIFF_PAIR_UNMERGED(p))
4858                        continue;
4859
4860                diff_fill_oid_info(p->one);
4861                diff_fill_oid_info(p->two);
4862
4863                len1 = remove_space(p->one->path, strlen(p->one->path));
4864                len2 = remove_space(p->two->path, strlen(p->two->path));
4865                patch_id_add_string(&ctx, "diff--git");
4866                patch_id_add_string(&ctx, "a/");
4867                git_SHA1_Update(&ctx, p->one->path, len1);
4868                patch_id_add_string(&ctx, "b/");
4869                git_SHA1_Update(&ctx, p->two->path, len2);
4870
4871                if (p->one->mode == 0) {
4872                        patch_id_add_string(&ctx, "newfilemode");
4873                        patch_id_add_mode(&ctx, p->two->mode);
4874                        patch_id_add_string(&ctx, "---/dev/null");
4875                        patch_id_add_string(&ctx, "+++b/");
4876                        git_SHA1_Update(&ctx, p->two->path, len2);
4877                } else if (p->two->mode == 0) {
4878                        patch_id_add_string(&ctx, "deletedfilemode");
4879                        patch_id_add_mode(&ctx, p->one->mode);
4880                        patch_id_add_string(&ctx, "---a/");
4881                        git_SHA1_Update(&ctx, p->one->path, len1);
4882                        patch_id_add_string(&ctx, "+++/dev/null");
4883                } else {
4884                        patch_id_add_string(&ctx, "---a/");
4885                        git_SHA1_Update(&ctx, p->one->path, len1);
4886                        patch_id_add_string(&ctx, "+++b/");
4887                        git_SHA1_Update(&ctx, p->two->path, len2);
4888                }
4889
4890                if (diff_header_only)
4891                        continue;
4892
4893                if (fill_mmfile(&mf1, p->one) < 0 ||
4894                    fill_mmfile(&mf2, p->two) < 0)
4895                        return error("unable to read files to diff");
4896
4897                if (diff_filespec_is_binary(p->one) ||
4898                    diff_filespec_is_binary(p->two)) {
4899                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
4900                                        GIT_SHA1_HEXSZ);
4901                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
4902                                        GIT_SHA1_HEXSZ);
4903                        continue;
4904                }
4905
4906                xpp.flags = 0;
4907                xecfg.ctxlen = 3;
4908                xecfg.flags = 0;
4909                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4910                                  &xpp, &xecfg))
4911                        return error("unable to generate patch-id diff for %s",
4912                                     p->one->path);
4913        }
4914
4915        git_SHA1_Final(oid->hash, &ctx);
4916        return 0;
4917}
4918
4919int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
4920{
4921        struct diff_queue_struct *q = &diff_queued_diff;
4922        int i;
4923        int result = diff_get_patch_id(options, oid, diff_header_only);
4924
4925        for (i = 0; i < q->nr; i++)
4926                diff_free_filepair(q->queue[i]);
4927
4928        free(q->queue);
4929        DIFF_QUEUE_CLEAR(q);
4930
4931        return result;
4932}
4933
4934static int is_summary_empty(const struct diff_queue_struct *q)
4935{
4936        int i;
4937
4938        for (i = 0; i < q->nr; i++) {
4939                const struct diff_filepair *p = q->queue[i];
4940
4941                switch (p->status) {
4942                case DIFF_STATUS_DELETED:
4943                case DIFF_STATUS_ADDED:
4944                case DIFF_STATUS_COPIED:
4945                case DIFF_STATUS_RENAMED:
4946                        return 0;
4947                default:
4948                        if (p->score)
4949                                return 0;
4950                        if (p->one->mode && p->two->mode &&
4951                            p->one->mode != p->two->mode)
4952                                return 0;
4953                        break;
4954                }
4955        }
4956        return 1;
4957}
4958
4959static const char rename_limit_warning[] =
4960N_("inexact rename detection was skipped due to too many files.");
4961
4962static const char degrade_cc_to_c_warning[] =
4963N_("only found copies from modified paths due to too many files.");
4964
4965static const char rename_limit_advice[] =
4966N_("you may want to set your %s variable to at least "
4967   "%d and retry the command.");
4968
4969void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4970{
4971        if (degraded_cc)
4972                warning(_(degrade_cc_to_c_warning));
4973        else if (needed)
4974                warning(_(rename_limit_warning));
4975        else
4976                return;
4977        if (0 < needed && needed < 32767)
4978                warning(_(rename_limit_advice), varname, needed);
4979}
4980
4981static void diff_flush_patch_all_file_pairs(struct diff_options *o)
4982{
4983        int i;
4984        struct diff_queue_struct *q = &diff_queued_diff;
4985
4986        if (WSEH_NEW & WS_RULE_MASK)
4987                die("BUG: WS rules bit mask overlaps with diff symbol flags");
4988
4989        for (i = 0; i < q->nr; i++) {
4990                struct diff_filepair *p = q->queue[i];
4991                if (check_pair_status(p))
4992                        diff_flush_patch(p, o);
4993        }
4994}
4995
4996void diff_flush(struct diff_options *options)
4997{
4998        struct diff_queue_struct *q = &diff_queued_diff;
4999        int i, output_format = options->output_format;
5000        int separator = 0;
5001        int dirstat_by_line = 0;
5002
5003        /*
5004         * Order: raw, stat, summary, patch
5005         * or:    name/name-status/checkdiff (other bits clear)
5006         */
5007        if (!q->nr)
5008                goto free_queue;
5009
5010        if (output_format & (DIFF_FORMAT_RAW |
5011                             DIFF_FORMAT_NAME |
5012                             DIFF_FORMAT_NAME_STATUS |
5013                             DIFF_FORMAT_CHECKDIFF)) {
5014                for (i = 0; i < q->nr; i++) {
5015                        struct diff_filepair *p = q->queue[i];
5016                        if (check_pair_status(p))
5017                                flush_one_pair(p, options);
5018                }
5019                separator++;
5020        }
5021
5022        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
5023                dirstat_by_line = 1;
5024
5025        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5026            dirstat_by_line) {
5027                struct diffstat_t diffstat;
5028
5029                memset(&diffstat, 0, sizeof(struct diffstat_t));
5030                for (i = 0; i < q->nr; i++) {
5031                        struct diff_filepair *p = q->queue[i];
5032                        if (check_pair_status(p))
5033                                diff_flush_stat(p, options, &diffstat);
5034                }
5035                if (output_format & DIFF_FORMAT_NUMSTAT)
5036                        show_numstat(&diffstat, options);
5037                if (output_format & DIFF_FORMAT_DIFFSTAT)
5038                        show_stats(&diffstat, options);
5039                if (output_format & DIFF_FORMAT_SHORTSTAT)
5040                        show_shortstats(&diffstat, options);
5041                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5042                        show_dirstat_by_line(&diffstat, options);
5043                free_diffstat_info(&diffstat);
5044                separator++;
5045        }
5046        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5047                show_dirstat(options);
5048
5049        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5050                for (i = 0; i < q->nr; i++) {
5051                        diff_summary(options, q->queue[i]);
5052                }
5053                separator++;
5054        }
5055
5056        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5057            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
5058            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
5059                /*
5060                 * run diff_flush_patch for the exit status. setting
5061                 * options->file to /dev/null should be safe, because we
5062                 * aren't supposed to produce any output anyway.
5063                 */
5064                if (options->close_file)
5065                        fclose(options->file);
5066                options->file = xfopen("/dev/null", "w");
5067                options->close_file = 1;
5068                for (i = 0; i < q->nr; i++) {
5069                        struct diff_filepair *p = q->queue[i];
5070                        if (check_pair_status(p))
5071                                diff_flush_patch(p, options);
5072                        if (options->found_changes)
5073                                break;
5074                }
5075        }
5076
5077        if (output_format & DIFF_FORMAT_PATCH) {
5078                if (separator) {
5079                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5080                        if (options->stat_sep) {
5081                                /* attach patch instead of inline */
5082                                fputs(options->stat_sep, options->file);
5083                        }
5084                }
5085
5086                diff_flush_patch_all_file_pairs(options);
5087        }
5088
5089        if (output_format & DIFF_FORMAT_CALLBACK)
5090                options->format_callback(q, options, options->format_callback_data);
5091
5092        for (i = 0; i < q->nr; i++)
5093                diff_free_filepair(q->queue[i]);
5094free_queue:
5095        free(q->queue);
5096        DIFF_QUEUE_CLEAR(q);
5097        if (options->close_file)
5098                fclose(options->file);
5099
5100        /*
5101         * Report the content-level differences with HAS_CHANGES;
5102         * diff_addremove/diff_change does not set the bit when
5103         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5104         */
5105        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
5106                if (options->found_changes)
5107                        DIFF_OPT_SET(options, HAS_CHANGES);
5108                else
5109                        DIFF_OPT_CLR(options, HAS_CHANGES);
5110        }
5111}
5112
5113static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5114{
5115        return (((p->status == DIFF_STATUS_MODIFIED) &&
5116                 ((p->score &&
5117                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5118                  (!p->score &&
5119                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5120                ((p->status != DIFF_STATUS_MODIFIED) &&
5121                 filter_bit_tst(p->status, options)));
5122}
5123
5124static void diffcore_apply_filter(struct diff_options *options)
5125{
5126        int i;
5127        struct diff_queue_struct *q = &diff_queued_diff;
5128        struct diff_queue_struct outq;
5129
5130        DIFF_QUEUE_CLEAR(&outq);
5131
5132        if (!options->filter)
5133                return;
5134
5135        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
5136                int found;
5137                for (i = found = 0; !found && i < q->nr; i++) {
5138                        if (match_filter(options, q->queue[i]))
5139                                found++;
5140                }
5141                if (found)
5142                        return;
5143
5144                /* otherwise we will clear the whole queue
5145                 * by copying the empty outq at the end of this
5146                 * function, but first clear the current entries
5147                 * in the queue.
5148                 */
5149                for (i = 0; i < q->nr; i++)
5150                        diff_free_filepair(q->queue[i]);
5151        }
5152        else {
5153                /* Only the matching ones */
5154                for (i = 0; i < q->nr; i++) {
5155                        struct diff_filepair *p = q->queue[i];
5156                        if (match_filter(options, p))
5157                                diff_q(&outq, p);
5158                        else
5159                                diff_free_filepair(p);
5160                }
5161        }
5162        free(q->queue);
5163        *q = outq;
5164}
5165
5166/* Check whether two filespecs with the same mode and size are identical */
5167static int diff_filespec_is_identical(struct diff_filespec *one,
5168                                      struct diff_filespec *two)
5169{
5170        if (S_ISGITLINK(one->mode))
5171                return 0;
5172        if (diff_populate_filespec(one, 0))
5173                return 0;
5174        if (diff_populate_filespec(two, 0))
5175                return 0;
5176        return !memcmp(one->data, two->data, one->size);
5177}
5178
5179static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
5180{
5181        if (p->done_skip_stat_unmatch)
5182                return p->skip_stat_unmatch_result;
5183
5184        p->done_skip_stat_unmatch = 1;
5185        p->skip_stat_unmatch_result = 0;
5186        /*
5187         * 1. Entries that come from stat info dirtiness
5188         *    always have both sides (iow, not create/delete),
5189         *    one side of the object name is unknown, with
5190         *    the same mode and size.  Keep the ones that
5191         *    do not match these criteria.  They have real
5192         *    differences.
5193         *
5194         * 2. At this point, the file is known to be modified,
5195         *    with the same mode and size, and the object
5196         *    name of one side is unknown.  Need to inspect
5197         *    the identical contents.
5198         */
5199        if (!DIFF_FILE_VALID(p->one) || /* (1) */
5200            !DIFF_FILE_VALID(p->two) ||
5201            (p->one->oid_valid && p->two->oid_valid) ||
5202            (p->one->mode != p->two->mode) ||
5203            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
5204            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
5205            (p->one->size != p->two->size) ||
5206            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
5207                p->skip_stat_unmatch_result = 1;
5208        return p->skip_stat_unmatch_result;
5209}
5210
5211static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
5212{
5213        int i;
5214        struct diff_queue_struct *q = &diff_queued_diff;
5215        struct diff_queue_struct outq;
5216        DIFF_QUEUE_CLEAR(&outq);
5217
5218        for (i = 0; i < q->nr; i++) {
5219                struct diff_filepair *p = q->queue[i];
5220
5221                if (diff_filespec_check_stat_unmatch(p))
5222                        diff_q(&outq, p);
5223                else {
5224                        /*
5225                         * The caller can subtract 1 from skip_stat_unmatch
5226                         * to determine how many paths were dirty only
5227                         * due to stat info mismatch.
5228                         */
5229                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
5230                                diffopt->skip_stat_unmatch++;
5231                        diff_free_filepair(p);
5232                }
5233        }
5234        free(q->queue);
5235        *q = outq;
5236}
5237
5238static int diffnamecmp(const void *a_, const void *b_)
5239{
5240        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
5241        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
5242        const char *name_a, *name_b;
5243
5244        name_a = a->one ? a->one->path : a->two->path;
5245        name_b = b->one ? b->one->path : b->two->path;
5246        return strcmp(name_a, name_b);
5247}
5248
5249void diffcore_fix_diff_index(struct diff_options *options)
5250{
5251        struct diff_queue_struct *q = &diff_queued_diff;
5252        QSORT(q->queue, q->nr, diffnamecmp);
5253}
5254
5255void diffcore_std(struct diff_options *options)
5256{
5257        /* NOTE please keep the following in sync with diff_tree_combined() */
5258        if (options->skip_stat_unmatch)
5259                diffcore_skip_stat_unmatch(options);
5260        if (!options->found_follow) {
5261                /* See try_to_follow_renames() in tree-diff.c */
5262                if (options->break_opt != -1)
5263                        diffcore_break(options->break_opt);
5264                if (options->detect_rename)
5265                        diffcore_rename(options);
5266                if (options->break_opt != -1)
5267                        diffcore_merge_broken();
5268        }
5269        if (options->pickaxe)
5270                diffcore_pickaxe(options);
5271        if (options->orderfile)
5272                diffcore_order(options->orderfile);
5273        if (!options->found_follow)
5274                /* See try_to_follow_renames() in tree-diff.c */
5275                diff_resolve_rename_copy();
5276        diffcore_apply_filter(options);
5277
5278        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5279                DIFF_OPT_SET(options, HAS_CHANGES);
5280        else
5281                DIFF_OPT_CLR(options, HAS_CHANGES);
5282
5283        options->found_follow = 0;
5284}
5285
5286int diff_result_code(struct diff_options *opt, int status)
5287{
5288        int result = 0;
5289
5290        diff_warn_rename_limit("diff.renameLimit",
5291                               opt->needed_rename_limit,
5292                               opt->degraded_cc_to_c);
5293        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5294            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
5295                return status;
5296        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5297            DIFF_OPT_TST(opt, HAS_CHANGES))
5298                result |= 01;
5299        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
5300            DIFF_OPT_TST(opt, CHECK_FAILED))
5301                result |= 02;
5302        return result;
5303}
5304
5305int diff_can_quit_early(struct diff_options *opt)
5306{
5307        return (DIFF_OPT_TST(opt, QUICK) &&
5308                !opt->filter &&
5309                DIFF_OPT_TST(opt, HAS_CHANGES));
5310}
5311
5312/*
5313 * Shall changes to this submodule be ignored?
5314 *
5315 * Submodule changes can be configured to be ignored separately for each path,
5316 * but that configuration can be overridden from the command line.
5317 */
5318static int is_submodule_ignored(const char *path, struct diff_options *options)
5319{
5320        int ignored = 0;
5321        unsigned orig_flags = options->flags;
5322        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
5323                set_diffopt_flags_from_submodule_config(options, path);
5324        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
5325                ignored = 1;
5326        options->flags = orig_flags;
5327        return ignored;
5328}
5329
5330void diff_addremove(struct diff_options *options,
5331                    int addremove, unsigned mode,
5332                    const struct object_id *oid,
5333                    int oid_valid,
5334                    const char *concatpath, unsigned dirty_submodule)
5335{
5336        struct diff_filespec *one, *two;
5337
5338        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
5339                return;
5340
5341        /* This may look odd, but it is a preparation for
5342         * feeding "there are unchanged files which should
5343         * not produce diffs, but when you are doing copy
5344         * detection you would need them, so here they are"
5345         * entries to the diff-core.  They will be prefixed
5346         * with something like '=' or '*' (I haven't decided
5347         * which but should not make any difference).
5348         * Feeding the same new and old to diff_change()
5349         * also has the same effect.
5350         * Before the final output happens, they are pruned after
5351         * merged into rename/copy pairs as appropriate.
5352         */
5353        if (DIFF_OPT_TST(options, REVERSE_DIFF))
5354                addremove = (addremove == '+' ? '-' :
5355                             addremove == '-' ? '+' : addremove);
5356
5357        if (options->prefix &&
5358            strncmp(concatpath, options->prefix, options->prefix_length))
5359                return;
5360
5361        one = alloc_filespec(concatpath);
5362        two = alloc_filespec(concatpath);
5363
5364        if (addremove != '+')
5365                fill_filespec(one, oid, oid_valid, mode);
5366        if (addremove != '-') {
5367                fill_filespec(two, oid, oid_valid, mode);
5368                two->dirty_submodule = dirty_submodule;
5369        }
5370
5371        diff_queue(&diff_queued_diff, one, two);
5372        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5373                DIFF_OPT_SET(options, HAS_CHANGES);
5374}
5375
5376void diff_change(struct diff_options *options,
5377                 unsigned old_mode, unsigned new_mode,
5378                 const struct object_id *old_oid,
5379                 const struct object_id *new_oid,
5380                 int old_oid_valid, int new_oid_valid,
5381                 const char *concatpath,
5382                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
5383{
5384        struct diff_filespec *one, *two;
5385        struct diff_filepair *p;
5386
5387        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
5388            is_submodule_ignored(concatpath, options))
5389                return;
5390
5391        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
5392                SWAP(old_mode, new_mode);
5393                SWAP(old_oid, new_oid);
5394                SWAP(old_oid_valid, new_oid_valid);
5395                SWAP(old_dirty_submodule, new_dirty_submodule);
5396        }
5397
5398        if (options->prefix &&
5399            strncmp(concatpath, options->prefix, options->prefix_length))
5400                return;
5401
5402        one = alloc_filespec(concatpath);
5403        two = alloc_filespec(concatpath);
5404        fill_filespec(one, old_oid, old_oid_valid, old_mode);
5405        fill_filespec(two, new_oid, new_oid_valid, new_mode);
5406        one->dirty_submodule = old_dirty_submodule;
5407        two->dirty_submodule = new_dirty_submodule;
5408        p = diff_queue(&diff_queued_diff, one, two);
5409
5410        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5411                return;
5412
5413        if (DIFF_OPT_TST(options, QUICK) && options->skip_stat_unmatch &&
5414            !diff_filespec_check_stat_unmatch(p))
5415                return;
5416
5417        DIFF_OPT_SET(options, HAS_CHANGES);
5418}
5419
5420struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
5421{
5422        struct diff_filepair *pair;
5423        struct diff_filespec *one, *two;
5424
5425        if (options->prefix &&
5426            strncmp(path, options->prefix, options->prefix_length))
5427                return NULL;
5428
5429        one = alloc_filespec(path);
5430        two = alloc_filespec(path);
5431        pair = diff_queue(&diff_queued_diff, one, two);
5432        pair->is_unmerged = 1;
5433        return pair;
5434}
5435
5436static char *run_textconv(const char *pgm, struct diff_filespec *spec,
5437                size_t *outsize)
5438{
5439        struct diff_tempfile *temp;
5440        const char *argv[3];
5441        const char **arg = argv;
5442        struct child_process child = CHILD_PROCESS_INIT;
5443        struct strbuf buf = STRBUF_INIT;
5444        int err = 0;
5445
5446        temp = prepare_temp_file(spec->path, spec);
5447        *arg++ = pgm;
5448        *arg++ = temp->name;
5449        *arg = NULL;
5450
5451        child.use_shell = 1;
5452        child.argv = argv;
5453        child.out = -1;
5454        if (start_command(&child)) {
5455                remove_tempfile();
5456                return NULL;
5457        }
5458
5459        if (strbuf_read(&buf, child.out, 0) < 0)
5460                err = error("error reading from textconv command '%s'", pgm);
5461        close(child.out);
5462
5463        if (finish_command(&child) || err) {
5464                strbuf_release(&buf);
5465                remove_tempfile();
5466                return NULL;
5467        }
5468        remove_tempfile();
5469
5470        return strbuf_detach(&buf, outsize);
5471}
5472
5473size_t fill_textconv(struct userdiff_driver *driver,
5474                     struct diff_filespec *df,
5475                     char **outbuf)
5476{
5477        size_t size;
5478
5479        if (!driver) {
5480                if (!DIFF_FILE_VALID(df)) {
5481                        *outbuf = "";
5482                        return 0;
5483                }
5484                if (diff_populate_filespec(df, 0))
5485                        die("unable to read files to diff");
5486                *outbuf = df->data;
5487                return df->size;
5488        }
5489
5490        if (!driver->textconv)
5491                die("BUG: fill_textconv called with non-textconv driver");
5492
5493        if (driver->textconv_cache && df->oid_valid) {
5494                *outbuf = notes_cache_get(driver->textconv_cache,
5495                                          &df->oid,
5496                                          &size);
5497                if (*outbuf)
5498                        return size;
5499        }
5500
5501        *outbuf = run_textconv(driver->textconv, df, &size);
5502        if (!*outbuf)
5503                die("unable to read files to diff");
5504
5505        if (driver->textconv_cache && df->oid_valid) {
5506                /* ignore errors, as we might be in a readonly repository */
5507                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
5508                                size);
5509                /*
5510                 * we could save up changes and flush them all at the end,
5511                 * but we would need an extra call after all diffing is done.
5512                 * Since generating a cache entry is the slow path anyway,
5513                 * this extra overhead probably isn't a big deal.
5514                 */
5515                notes_cache_write(driver->textconv_cache);
5516        }
5517
5518        return size;
5519}
5520
5521int textconv_object(const char *path,
5522                    unsigned mode,
5523                    const struct object_id *oid,
5524                    int oid_valid,
5525                    char **buf,
5526                    unsigned long *buf_size)
5527{
5528        struct diff_filespec *df;
5529        struct userdiff_driver *textconv;
5530
5531        df = alloc_filespec(path);
5532        fill_filespec(df, oid, oid_valid, mode);
5533        textconv = get_textconv(df);
5534        if (!textconv) {
5535                free_filespec(df);
5536                return 0;
5537        }
5538
5539        *buf_size = fill_textconv(textconv, df, buf);
5540        free_filespec(df);
5541        return 1;
5542}
5543
5544void setup_diff_pager(struct diff_options *opt)
5545{
5546        /*
5547         * If the user asked for our exit code, then either they want --quiet
5548         * or --exit-code. We should definitely not bother with a pager in the
5549         * former case, as we will generate no output. Since we still properly
5550         * report our exit code even when a pager is run, we _could_ run a
5551         * pager with --exit-code. But since we have not done so historically,
5552         * and because it is easy to find people oneline advising "git diff
5553         * --exit-code" in hooks and other scripts, we do not do so.
5554         */
5555        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5556            check_pager_config("diff") != 0)
5557                setup_pager();
5558}