48f719fb0794fecdcbc3dfeee536e71458695293
   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_SUBMODULE_ADD,
 565        DIFF_SYMBOL_SUBMODULE_DEL,
 566        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 567        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 568        DIFF_SYMBOL_SUBMODULE_HEADER,
 569        DIFF_SYMBOL_SUBMODULE_ERROR,
 570        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 571        DIFF_SYMBOL_REWRITE_DIFF,
 572        DIFF_SYMBOL_BINARY_FILES,
 573        DIFF_SYMBOL_HEADER,
 574        DIFF_SYMBOL_FILEPAIR_PLUS,
 575        DIFF_SYMBOL_FILEPAIR_MINUS,
 576        DIFF_SYMBOL_WORDS_PORCELAIN,
 577        DIFF_SYMBOL_WORDS,
 578        DIFF_SYMBOL_CONTEXT,
 579        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 580        DIFF_SYMBOL_PLUS,
 581        DIFF_SYMBOL_MINUS,
 582        DIFF_SYMBOL_NO_LF_EOF,
 583        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 584        DIFF_SYMBOL_CONTEXT_MARKER,
 585        DIFF_SYMBOL_SEPARATOR
 586};
 587/*
 588 * Flags for content lines:
 589 * 0..12 are whitespace rules
 590 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 591 * 16 is marking if the line is blank at EOF
 592 */
 593#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF (1<<16)
 594#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 595
 596static void emit_line_ws_markup(struct diff_options *o,
 597                                const char *set, const char *reset,
 598                                const char *line, int len, char sign,
 599                                unsigned ws_rule, int blank_at_eof)
 600{
 601        const char *ws = NULL;
 602
 603        if (o->ws_error_highlight & ws_rule) {
 604                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
 605                if (!*ws)
 606                        ws = NULL;
 607        }
 608
 609        if (!ws)
 610                emit_line_0(o, set, reset, sign, line, len);
 611        else if (blank_at_eof)
 612                /* Blank line at EOF - paint '+' as well */
 613                emit_line_0(o, ws, reset, sign, line, len);
 614        else {
 615                /* Emit just the prefix, then the rest. */
 616                emit_line_0(o, set, reset, sign, "", 0);
 617                ws_check_emit(line, len, ws_rule,
 618                              o->file, set, reset, ws);
 619        }
 620}
 621
 622static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
 623                             const char *line, int len, unsigned flags)
 624{
 625        static const char *nneof = " No newline at end of file\n";
 626        const char *context, *reset, *set, *meta, *fraginfo;
 627        switch (s) {
 628        case DIFF_SYMBOL_NO_LF_EOF:
 629                context = diff_get_color_opt(o, DIFF_CONTEXT);
 630                reset = diff_get_color_opt(o, DIFF_RESET);
 631                putc('\n', o->file);
 632                emit_line_0(o, context, reset, '\\',
 633                            nneof, strlen(nneof));
 634                break;
 635        case DIFF_SYMBOL_SUBMODULE_HEADER:
 636        case DIFF_SYMBOL_SUBMODULE_ERROR:
 637        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
 638        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
 639                emit_line(o, "", "", line, len);
 640                break;
 641        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
 642        case DIFF_SYMBOL_CONTEXT_MARKER:
 643                context = diff_get_color_opt(o, DIFF_CONTEXT);
 644                reset = diff_get_color_opt(o, DIFF_RESET);
 645                emit_line(o, context, reset, line, len);
 646                break;
 647        case DIFF_SYMBOL_SEPARATOR:
 648                fprintf(o->file, "%s%c",
 649                        diff_line_prefix(o),
 650                        o->line_termination);
 651                break;
 652        case DIFF_SYMBOL_CONTEXT:
 653                set = diff_get_color_opt(o, DIFF_CONTEXT);
 654                reset = diff_get_color_opt(o, DIFF_RESET);
 655                emit_line_ws_markup(o, set, reset, line, len, ' ',
 656                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
 657                break;
 658        case DIFF_SYMBOL_PLUS:
 659                set = diff_get_color_opt(o, DIFF_FILE_NEW);
 660                reset = diff_get_color_opt(o, DIFF_RESET);
 661                emit_line_ws_markup(o, set, reset, line, len, '+',
 662                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
 663                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
 664                break;
 665        case DIFF_SYMBOL_MINUS:
 666                set = diff_get_color_opt(o, DIFF_FILE_OLD);
 667                reset = diff_get_color_opt(o, DIFF_RESET);
 668                emit_line_ws_markup(o, set, reset, line, len, '-',
 669                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
 670                break;
 671        case DIFF_SYMBOL_WORDS_PORCELAIN:
 672                context = diff_get_color_opt(o, DIFF_CONTEXT);
 673                reset = diff_get_color_opt(o, DIFF_RESET);
 674                emit_line(o, context, reset, line, len);
 675                fputs("~\n", o->file);
 676                break;
 677        case DIFF_SYMBOL_WORDS:
 678                context = diff_get_color_opt(o, DIFF_CONTEXT);
 679                reset = diff_get_color_opt(o, DIFF_RESET);
 680                /*
 681                 * Skip the prefix character, if any.  With
 682                 * diff_suppress_blank_empty, there may be
 683                 * none.
 684                 */
 685                if (line[0] != '\n') {
 686                        line++;
 687                        len--;
 688                }
 689                emit_line(o, context, reset, line, len);
 690                break;
 691        case DIFF_SYMBOL_FILEPAIR_PLUS:
 692                meta = diff_get_color_opt(o, DIFF_METAINFO);
 693                reset = diff_get_color_opt(o, DIFF_RESET);
 694                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
 695                        line, reset,
 696                        strchr(line, ' ') ? "\t" : "");
 697                break;
 698        case DIFF_SYMBOL_FILEPAIR_MINUS:
 699                meta = diff_get_color_opt(o, DIFF_METAINFO);
 700                reset = diff_get_color_opt(o, DIFF_RESET);
 701                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
 702                        line, reset,
 703                        strchr(line, ' ') ? "\t" : "");
 704                break;
 705        case DIFF_SYMBOL_BINARY_FILES:
 706        case DIFF_SYMBOL_HEADER:
 707                fprintf(o->file, "%s", line);
 708                break;
 709        case DIFF_SYMBOL_REWRITE_DIFF:
 710                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 711                reset = diff_get_color_opt(o, DIFF_RESET);
 712                emit_line(o, fraginfo, reset, line, len);
 713                break;
 714        case DIFF_SYMBOL_SUBMODULE_ADD:
 715                set = diff_get_color_opt(o, DIFF_FILE_NEW);
 716                reset = diff_get_color_opt(o, DIFF_RESET);
 717                emit_line(o, set, reset, line, len);
 718                break;
 719        case DIFF_SYMBOL_SUBMODULE_DEL:
 720                set = diff_get_color_opt(o, DIFF_FILE_OLD);
 721                reset = diff_get_color_opt(o, DIFF_RESET);
 722                emit_line(o, set, reset, line, len);
 723                break;
 724        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
 725                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
 726                        diff_line_prefix(o), line);
 727                break;
 728        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
 729                fprintf(o->file, "%sSubmodule %s contains modified content\n",
 730                        diff_line_prefix(o), line);
 731                break;
 732        default:
 733                die("BUG: unknown diff symbol");
 734        }
 735}
 736
 737void diff_emit_submodule_del(struct diff_options *o, const char *line)
 738{
 739        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
 740}
 741
 742void diff_emit_submodule_add(struct diff_options *o, const char *line)
 743{
 744        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
 745}
 746
 747void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
 748{
 749        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 750                         path, strlen(path), 0);
 751}
 752
 753void diff_emit_submodule_modified(struct diff_options *o, const char *path)
 754{
 755        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
 756                         path, strlen(path), 0);
 757}
 758
 759void diff_emit_submodule_header(struct diff_options *o, const char *header)
 760{
 761        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
 762                         header, strlen(header), 0);
 763}
 764
 765void diff_emit_submodule_error(struct diff_options *o, const char *err)
 766{
 767        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
 768}
 769
 770void diff_emit_submodule_pipethrough(struct diff_options *o,
 771                                     const char *line, int len)
 772{
 773        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
 774}
 775
 776static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 777{
 778        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 779              ecbdata->blank_at_eof_in_preimage &&
 780              ecbdata->blank_at_eof_in_postimage &&
 781              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 782              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 783                return 0;
 784        return ws_blank_line(line, len, ecbdata->ws_rule);
 785}
 786
 787static void emit_add_line(const char *reset,
 788                          struct emit_callback *ecbdata,
 789                          const char *line, int len)
 790{
 791        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
 792        if (new_blank_line_at_eof(ecbdata, line, len))
 793                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
 794
 795        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
 796}
 797
 798static void emit_del_line(const char *reset,
 799                          struct emit_callback *ecbdata,
 800                          const char *line, int len)
 801{
 802        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
 803        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
 804}
 805
 806static void emit_context_line(const char *reset,
 807                              struct emit_callback *ecbdata,
 808                              const char *line, int len)
 809{
 810        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
 811        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
 812}
 813
 814static void emit_hunk_header(struct emit_callback *ecbdata,
 815                             const char *line, int len)
 816{
 817        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
 818        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 819        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 820        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 821        static const char atat[2] = { '@', '@' };
 822        const char *cp, *ep;
 823        struct strbuf msgbuf = STRBUF_INIT;
 824        int org_len = len;
 825        int i = 1;
 826
 827        /*
 828         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 829         * it always is at least 10 bytes long.
 830         */
 831        if (len < 10 ||
 832            memcmp(line, atat, 2) ||
 833            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 834                emit_diff_symbol(ecbdata->opt,
 835                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
 836                return;
 837        }
 838        ep += 2; /* skip over @@ */
 839
 840        /* The hunk header in fraginfo color */
 841        strbuf_addstr(&msgbuf, frag);
 842        strbuf_add(&msgbuf, line, ep - line);
 843        strbuf_addstr(&msgbuf, reset);
 844
 845        /*
 846         * trailing "\r\n"
 847         */
 848        for ( ; i < 3; i++)
 849                if (line[len - i] == '\r' || line[len - i] == '\n')
 850                        len--;
 851
 852        /* blank before the func header */
 853        for (cp = ep; ep - line < len; ep++)
 854                if (*ep != ' ' && *ep != '\t')
 855                        break;
 856        if (ep != cp) {
 857                strbuf_addstr(&msgbuf, context);
 858                strbuf_add(&msgbuf, cp, ep - cp);
 859                strbuf_addstr(&msgbuf, reset);
 860        }
 861
 862        if (ep < line + len) {
 863                strbuf_addstr(&msgbuf, func);
 864                strbuf_add(&msgbuf, ep, line + len - ep);
 865                strbuf_addstr(&msgbuf, reset);
 866        }
 867
 868        strbuf_add(&msgbuf, line + len, org_len - len);
 869        strbuf_complete_line(&msgbuf);
 870        emit_diff_symbol(ecbdata->opt,
 871                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
 872        strbuf_release(&msgbuf);
 873}
 874
 875static struct diff_tempfile *claim_diff_tempfile(void) {
 876        int i;
 877        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 878                if (!diff_temp[i].name)
 879                        return diff_temp + i;
 880        die("BUG: diff is failing to clean up its tempfiles");
 881}
 882
 883static void remove_tempfile(void)
 884{
 885        int i;
 886        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 887                if (is_tempfile_active(&diff_temp[i].tempfile))
 888                        delete_tempfile(&diff_temp[i].tempfile);
 889                diff_temp[i].name = NULL;
 890        }
 891}
 892
 893static void add_line_count(struct strbuf *out, int count)
 894{
 895        switch (count) {
 896        case 0:
 897                strbuf_addstr(out, "0,0");
 898                break;
 899        case 1:
 900                strbuf_addstr(out, "1");
 901                break;
 902        default:
 903                strbuf_addf(out, "1,%d", count);
 904                break;
 905        }
 906}
 907
 908static void emit_rewrite_lines(struct emit_callback *ecb,
 909                               int prefix, const char *data, int size)
 910{
 911        const char *endp = NULL;
 912        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 913
 914        while (0 < size) {
 915                int len;
 916
 917                endp = memchr(data, '\n', size);
 918                len = endp ? (endp - data + 1) : size;
 919                if (prefix != '+') {
 920                        ecb->lno_in_preimage++;
 921                        emit_del_line(reset, ecb, data, len);
 922                } else {
 923                        ecb->lno_in_postimage++;
 924                        emit_add_line(reset, ecb, data, len);
 925                }
 926                size -= len;
 927                data += len;
 928        }
 929        if (!endp)
 930                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
 931}
 932
 933static void emit_rewrite_diff(const char *name_a,
 934                              const char *name_b,
 935                              struct diff_filespec *one,
 936                              struct diff_filespec *two,
 937                              struct userdiff_driver *textconv_one,
 938                              struct userdiff_driver *textconv_two,
 939                              struct diff_options *o)
 940{
 941        int lc_a, lc_b;
 942        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 943        const char *a_prefix, *b_prefix;
 944        char *data_one, *data_two;
 945        size_t size_one, size_two;
 946        struct emit_callback ecbdata;
 947        struct strbuf out = STRBUF_INIT;
 948
 949        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 950                a_prefix = o->b_prefix;
 951                b_prefix = o->a_prefix;
 952        } else {
 953                a_prefix = o->a_prefix;
 954                b_prefix = o->b_prefix;
 955        }
 956
 957        name_a += (*name_a == '/');
 958        name_b += (*name_b == '/');
 959
 960        strbuf_reset(&a_name);
 961        strbuf_reset(&b_name);
 962        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 963        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 964
 965        size_one = fill_textconv(textconv_one, one, &data_one);
 966        size_two = fill_textconv(textconv_two, two, &data_two);
 967
 968        memset(&ecbdata, 0, sizeof(ecbdata));
 969        ecbdata.color_diff = want_color(o->use_color);
 970        ecbdata.ws_rule = whitespace_rule(name_b);
 971        ecbdata.opt = o;
 972        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 973                mmfile_t mf1, mf2;
 974                mf1.ptr = (char *)data_one;
 975                mf2.ptr = (char *)data_two;
 976                mf1.size = size_one;
 977                mf2.size = size_two;
 978                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 979        }
 980        ecbdata.lno_in_preimage = 1;
 981        ecbdata.lno_in_postimage = 1;
 982
 983        lc_a = count_lines(data_one, size_one);
 984        lc_b = count_lines(data_two, size_two);
 985
 986        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
 987                         a_name.buf, a_name.len, 0);
 988        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
 989                         b_name.buf, b_name.len, 0);
 990
 991        strbuf_addstr(&out, "@@ -");
 992        if (!o->irreversible_delete)
 993                add_line_count(&out, lc_a);
 994        else
 995                strbuf_addstr(&out, "?,?");
 996        strbuf_addstr(&out, " +");
 997        add_line_count(&out, lc_b);
 998        strbuf_addstr(&out, " @@\n");
 999        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1000        strbuf_release(&out);
1001
1002        if (lc_a && !o->irreversible_delete)
1003                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1004        if (lc_b)
1005                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1006        if (textconv_one)
1007                free((char *)data_one);
1008        if (textconv_two)
1009                free((char *)data_two);
1010}
1011
1012struct diff_words_buffer {
1013        mmfile_t text;
1014        long alloc;
1015        struct diff_words_orig {
1016                const char *begin, *end;
1017        } *orig;
1018        int orig_nr, orig_alloc;
1019};
1020
1021static void diff_words_append(char *line, unsigned long len,
1022                struct diff_words_buffer *buffer)
1023{
1024        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1025        line++;
1026        len--;
1027        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1028        buffer->text.size += len;
1029        buffer->text.ptr[buffer->text.size] = '\0';
1030}
1031
1032struct diff_words_style_elem {
1033        const char *prefix;
1034        const char *suffix;
1035        const char *color; /* NULL; filled in by the setup code if
1036                            * color is enabled */
1037};
1038
1039struct diff_words_style {
1040        enum diff_words_type type;
1041        struct diff_words_style_elem new, old, ctx;
1042        const char *newline;
1043};
1044
1045static struct diff_words_style diff_words_styles[] = {
1046        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1047        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1048        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1049};
1050
1051struct diff_words_data {
1052        struct diff_words_buffer minus, plus;
1053        const char *current_plus;
1054        int last_minus;
1055        struct diff_options *opt;
1056        regex_t *word_regex;
1057        enum diff_words_type type;
1058        struct diff_words_style *style;
1059};
1060
1061static int fn_out_diff_words_write_helper(FILE *fp,
1062                                          struct diff_words_style_elem *st_el,
1063                                          const char *newline,
1064                                          size_t count, const char *buf,
1065                                          const char *line_prefix)
1066{
1067        int print = 0;
1068
1069        while (count) {
1070                char *p = memchr(buf, '\n', count);
1071                if (print)
1072                        fputs(line_prefix, fp);
1073                if (p != buf) {
1074                        if (st_el->color && fputs(st_el->color, fp) < 0)
1075                                return -1;
1076                        if (fputs(st_el->prefix, fp) < 0 ||
1077                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
1078                            fputs(st_el->suffix, fp) < 0)
1079                                return -1;
1080                        if (st_el->color && *st_el->color
1081                            && fputs(GIT_COLOR_RESET, fp) < 0)
1082                                return -1;
1083                }
1084                if (!p)
1085                        return 0;
1086                if (fputs(newline, fp) < 0)
1087                        return -1;
1088                count -= p + 1 - buf;
1089                buf = p + 1;
1090                print = 1;
1091        }
1092        return 0;
1093}
1094
1095/*
1096 * '--color-words' algorithm can be described as:
1097 *
1098 *   1. collect the minus/plus lines of a diff hunk, divided into
1099 *      minus-lines and plus-lines;
1100 *
1101 *   2. break both minus-lines and plus-lines into words and
1102 *      place them into two mmfile_t with one word for each line;
1103 *
1104 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1105 *
1106 * And for the common parts of the both file, we output the plus side text.
1107 * diff_words->current_plus is used to trace the current position of the plus file
1108 * which printed. diff_words->last_minus is used to trace the last minus word
1109 * printed.
1110 *
1111 * For '--graph' to work with '--color-words', we need to output the graph prefix
1112 * on each line of color words output. Generally, there are two conditions on
1113 * which we should output the prefix.
1114 *
1115 *   1. diff_words->last_minus == 0 &&
1116 *      diff_words->current_plus == diff_words->plus.text.ptr
1117 *
1118 *      that is: the plus text must start as a new line, and if there is no minus
1119 *      word printed, a graph prefix must be printed.
1120 *
1121 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1122 *      *(diff_words->current_plus - 1) == '\n'
1123 *
1124 *      that is: a graph prefix must be printed following a '\n'
1125 */
1126static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1127{
1128        if ((diff_words->last_minus == 0 &&
1129                diff_words->current_plus == diff_words->plus.text.ptr) ||
1130                (diff_words->current_plus > diff_words->plus.text.ptr &&
1131                *(diff_words->current_plus - 1) == '\n')) {
1132                return 1;
1133        } else {
1134                return 0;
1135        }
1136}
1137
1138static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1139{
1140        struct diff_words_data *diff_words = priv;
1141        struct diff_words_style *style = diff_words->style;
1142        int minus_first, minus_len, plus_first, plus_len;
1143        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1144        struct diff_options *opt = diff_words->opt;
1145        const char *line_prefix;
1146
1147        if (line[0] != '@' || parse_hunk_header(line, len,
1148                        &minus_first, &minus_len, &plus_first, &plus_len))
1149                return;
1150
1151        assert(opt);
1152        line_prefix = diff_line_prefix(opt);
1153
1154        /* POSIX requires that first be decremented by one if len == 0... */
1155        if (minus_len) {
1156                minus_begin = diff_words->minus.orig[minus_first].begin;
1157                minus_end =
1158                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1159        } else
1160                minus_begin = minus_end =
1161                        diff_words->minus.orig[minus_first].end;
1162
1163        if (plus_len) {
1164                plus_begin = diff_words->plus.orig[plus_first].begin;
1165                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1166        } else
1167                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1168
1169        if (color_words_output_graph_prefix(diff_words)) {
1170                fputs(line_prefix, diff_words->opt->file);
1171        }
1172        if (diff_words->current_plus != plus_begin) {
1173                fn_out_diff_words_write_helper(diff_words->opt->file,
1174                                &style->ctx, style->newline,
1175                                plus_begin - diff_words->current_plus,
1176                                diff_words->current_plus, line_prefix);
1177                if (*(plus_begin - 1) == '\n')
1178                        fputs(line_prefix, diff_words->opt->file);
1179        }
1180        if (minus_begin != minus_end) {
1181                fn_out_diff_words_write_helper(diff_words->opt->file,
1182                                &style->old, style->newline,
1183                                minus_end - minus_begin, minus_begin,
1184                                line_prefix);
1185        }
1186        if (plus_begin != plus_end) {
1187                fn_out_diff_words_write_helper(diff_words->opt->file,
1188                                &style->new, style->newline,
1189                                plus_end - plus_begin, plus_begin,
1190                                line_prefix);
1191        }
1192
1193        diff_words->current_plus = plus_end;
1194        diff_words->last_minus = minus_first;
1195}
1196
1197/* This function starts looking at *begin, and returns 0 iff a word was found. */
1198static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1199                int *begin, int *end)
1200{
1201        if (word_regex && *begin < buffer->size) {
1202                regmatch_t match[1];
1203                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1204                                 buffer->size - *begin, 1, match, 0)) {
1205                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1206                                        '\n', match[0].rm_eo - match[0].rm_so);
1207                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1208                        *begin += match[0].rm_so;
1209                        return *begin >= *end;
1210                }
1211                return -1;
1212        }
1213
1214        /* find the next word */
1215        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1216                (*begin)++;
1217        if (*begin >= buffer->size)
1218                return -1;
1219
1220        /* find the end of the word */
1221        *end = *begin + 1;
1222        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1223                (*end)++;
1224
1225        return 0;
1226}
1227
1228/*
1229 * This function splits the words in buffer->text, stores the list with
1230 * newline separator into out, and saves the offsets of the original words
1231 * in buffer->orig.
1232 */
1233static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1234                regex_t *word_regex)
1235{
1236        int i, j;
1237        long alloc = 0;
1238
1239        out->size = 0;
1240        out->ptr = NULL;
1241
1242        /* fake an empty "0th" word */
1243        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1244        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1245        buffer->orig_nr = 1;
1246
1247        for (i = 0; i < buffer->text.size; i++) {
1248                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1249                        return;
1250
1251                /* store original boundaries */
1252                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1253                                buffer->orig_alloc);
1254                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1255                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1256                buffer->orig_nr++;
1257
1258                /* store one word */
1259                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1260                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1261                out->ptr[out->size + j - i] = '\n';
1262                out->size += j - i + 1;
1263
1264                i = j - 1;
1265        }
1266}
1267
1268/* this executes the word diff on the accumulated buffers */
1269static void diff_words_show(struct diff_words_data *diff_words)
1270{
1271        xpparam_t xpp;
1272        xdemitconf_t xecfg;
1273        mmfile_t minus, plus;
1274        struct diff_words_style *style = diff_words->style;
1275
1276        struct diff_options *opt = diff_words->opt;
1277        const char *line_prefix;
1278
1279        assert(opt);
1280        line_prefix = diff_line_prefix(opt);
1281
1282        /* special case: only removal */
1283        if (!diff_words->plus.text.size) {
1284                fputs(line_prefix, diff_words->opt->file);
1285                fn_out_diff_words_write_helper(diff_words->opt->file,
1286                        &style->old, style->newline,
1287                        diff_words->minus.text.size,
1288                        diff_words->minus.text.ptr, line_prefix);
1289                diff_words->minus.text.size = 0;
1290                return;
1291        }
1292
1293        diff_words->current_plus = diff_words->plus.text.ptr;
1294        diff_words->last_minus = 0;
1295
1296        memset(&xpp, 0, sizeof(xpp));
1297        memset(&xecfg, 0, sizeof(xecfg));
1298        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1299        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1300        xpp.flags = 0;
1301        /* as only the hunk header will be parsed, we need a 0-context */
1302        xecfg.ctxlen = 0;
1303        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1304                          &xpp, &xecfg))
1305                die("unable to generate word diff");
1306        free(minus.ptr);
1307        free(plus.ptr);
1308        if (diff_words->current_plus != diff_words->plus.text.ptr +
1309                        diff_words->plus.text.size) {
1310                if (color_words_output_graph_prefix(diff_words))
1311                        fputs(line_prefix, diff_words->opt->file);
1312                fn_out_diff_words_write_helper(diff_words->opt->file,
1313                        &style->ctx, style->newline,
1314                        diff_words->plus.text.ptr + diff_words->plus.text.size
1315                        - diff_words->current_plus, diff_words->current_plus,
1316                        line_prefix);
1317        }
1318        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1319}
1320
1321/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1322static void diff_words_flush(struct emit_callback *ecbdata)
1323{
1324        if (ecbdata->diff_words->minus.text.size ||
1325            ecbdata->diff_words->plus.text.size)
1326                diff_words_show(ecbdata->diff_words);
1327}
1328
1329static void diff_filespec_load_driver(struct diff_filespec *one)
1330{
1331        /* Use already-loaded driver */
1332        if (one->driver)
1333                return;
1334
1335        if (S_ISREG(one->mode))
1336                one->driver = userdiff_find_by_path(one->path);
1337
1338        /* Fallback to default settings */
1339        if (!one->driver)
1340                one->driver = userdiff_find_by_name("default");
1341}
1342
1343static const char *userdiff_word_regex(struct diff_filespec *one)
1344{
1345        diff_filespec_load_driver(one);
1346        return one->driver->word_regex;
1347}
1348
1349static void init_diff_words_data(struct emit_callback *ecbdata,
1350                                 struct diff_options *orig_opts,
1351                                 struct diff_filespec *one,
1352                                 struct diff_filespec *two)
1353{
1354        int i;
1355        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1356        memcpy(o, orig_opts, sizeof(struct diff_options));
1357
1358        ecbdata->diff_words =
1359                xcalloc(1, sizeof(struct diff_words_data));
1360        ecbdata->diff_words->type = o->word_diff;
1361        ecbdata->diff_words->opt = o;
1362        if (!o->word_regex)
1363                o->word_regex = userdiff_word_regex(one);
1364        if (!o->word_regex)
1365                o->word_regex = userdiff_word_regex(two);
1366        if (!o->word_regex)
1367                o->word_regex = diff_word_regex_cfg;
1368        if (o->word_regex) {
1369                ecbdata->diff_words->word_regex = (regex_t *)
1370                        xmalloc(sizeof(regex_t));
1371                if (regcomp(ecbdata->diff_words->word_regex,
1372                            o->word_regex,
1373                            REG_EXTENDED | REG_NEWLINE))
1374                        die ("Invalid regular expression: %s",
1375                             o->word_regex);
1376        }
1377        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1378                if (o->word_diff == diff_words_styles[i].type) {
1379                        ecbdata->diff_words->style =
1380                                &diff_words_styles[i];
1381                        break;
1382                }
1383        }
1384        if (want_color(o->use_color)) {
1385                struct diff_words_style *st = ecbdata->diff_words->style;
1386                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1387                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1388                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
1389        }
1390}
1391
1392static void free_diff_words_data(struct emit_callback *ecbdata)
1393{
1394        if (ecbdata->diff_words) {
1395                diff_words_flush(ecbdata);
1396                free (ecbdata->diff_words->opt);
1397                free (ecbdata->diff_words->minus.text.ptr);
1398                free (ecbdata->diff_words->minus.orig);
1399                free (ecbdata->diff_words->plus.text.ptr);
1400                free (ecbdata->diff_words->plus.orig);
1401                if (ecbdata->diff_words->word_regex) {
1402                        regfree(ecbdata->diff_words->word_regex);
1403                        free(ecbdata->diff_words->word_regex);
1404                }
1405                FREE_AND_NULL(ecbdata->diff_words);
1406        }
1407}
1408
1409const char *diff_get_color(int diff_use_color, enum color_diff ix)
1410{
1411        if (want_color(diff_use_color))
1412                return diff_colors[ix];
1413        return "";
1414}
1415
1416const char *diff_line_prefix(struct diff_options *opt)
1417{
1418        struct strbuf *msgbuf;
1419        if (!opt->output_prefix)
1420                return "";
1421
1422        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1423        return msgbuf->buf;
1424}
1425
1426static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1427{
1428        const char *cp;
1429        unsigned long allot;
1430        size_t l = len;
1431
1432        if (ecb->truncate)
1433                return ecb->truncate(line, len);
1434        cp = line;
1435        allot = l;
1436        while (0 < l) {
1437                (void) utf8_width(&cp, &l);
1438                if (!cp)
1439                        break; /* truncated in the middle? */
1440        }
1441        return allot - l;
1442}
1443
1444static void find_lno(const char *line, struct emit_callback *ecbdata)
1445{
1446        const char *p;
1447        ecbdata->lno_in_preimage = 0;
1448        ecbdata->lno_in_postimage = 0;
1449        p = strchr(line, '-');
1450        if (!p)
1451                return; /* cannot happen */
1452        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1453        p = strchr(p, '+');
1454        if (!p)
1455                return; /* cannot happen */
1456        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1457}
1458
1459static void fn_out_consume(void *priv, char *line, unsigned long len)
1460{
1461        struct emit_callback *ecbdata = priv;
1462        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1463        struct diff_options *o = ecbdata->opt;
1464
1465        o->found_changes = 1;
1466
1467        if (ecbdata->header) {
1468                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
1469                                 ecbdata->header->buf, ecbdata->header->len, 0);
1470                strbuf_reset(ecbdata->header);
1471                ecbdata->header = NULL;
1472        }
1473
1474        if (ecbdata->label_path[0]) {
1475                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1476                                 ecbdata->label_path[0],
1477                                 strlen(ecbdata->label_path[0]), 0);
1478                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1479                                 ecbdata->label_path[1],
1480                                 strlen(ecbdata->label_path[1]), 0);
1481                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1482        }
1483
1484        if (diff_suppress_blank_empty
1485            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1486                line[0] = '\n';
1487                len = 1;
1488        }
1489
1490        if (line[0] == '@') {
1491                if (ecbdata->diff_words)
1492                        diff_words_flush(ecbdata);
1493                len = sane_truncate_line(ecbdata, line, len);
1494                find_lno(line, ecbdata);
1495                emit_hunk_header(ecbdata, line, len);
1496                return;
1497        }
1498
1499        if (ecbdata->diff_words) {
1500                enum diff_symbol s =
1501                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
1502                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
1503                if (line[0] == '-') {
1504                        diff_words_append(line, len,
1505                                          &ecbdata->diff_words->minus);
1506                        return;
1507                } else if (line[0] == '+') {
1508                        diff_words_append(line, len,
1509                                          &ecbdata->diff_words->plus);
1510                        return;
1511                } else if (starts_with(line, "\\ ")) {
1512                        /*
1513                         * Eat the "no newline at eof" marker as if we
1514                         * saw a "+" or "-" line with nothing on it,
1515                         * and return without diff_words_flush() to
1516                         * defer processing. If this is the end of
1517                         * preimage, more "+" lines may come after it.
1518                         */
1519                        return;
1520                }
1521                diff_words_flush(ecbdata);
1522                emit_diff_symbol(o, s, line, len, 0);
1523                return;
1524        }
1525
1526        switch (line[0]) {
1527        case '+':
1528                ecbdata->lno_in_postimage++;
1529                emit_add_line(reset, ecbdata, line + 1, len - 1);
1530                break;
1531        case '-':
1532                ecbdata->lno_in_preimage++;
1533                emit_del_line(reset, ecbdata, line + 1, len - 1);
1534                break;
1535        case ' ':
1536                ecbdata->lno_in_postimage++;
1537                ecbdata->lno_in_preimage++;
1538                emit_context_line(reset, ecbdata, line + 1, len - 1);
1539                break;
1540        default:
1541                /* incomplete line at the end */
1542                ecbdata->lno_in_preimage++;
1543                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
1544                                 line, len, 0);
1545                break;
1546        }
1547}
1548
1549static char *pprint_rename(const char *a, const char *b)
1550{
1551        const char *old = a;
1552        const char *new = b;
1553        struct strbuf name = STRBUF_INIT;
1554        int pfx_length, sfx_length;
1555        int pfx_adjust_for_slash;
1556        int len_a = strlen(a);
1557        int len_b = strlen(b);
1558        int a_midlen, b_midlen;
1559        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1560        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1561
1562        if (qlen_a || qlen_b) {
1563                quote_c_style(a, &name, NULL, 0);
1564                strbuf_addstr(&name, " => ");
1565                quote_c_style(b, &name, NULL, 0);
1566                return strbuf_detach(&name, NULL);
1567        }
1568
1569        /* Find common prefix */
1570        pfx_length = 0;
1571        while (*old && *new && *old == *new) {
1572                if (*old == '/')
1573                        pfx_length = old - a + 1;
1574                old++;
1575                new++;
1576        }
1577
1578        /* Find common suffix */
1579        old = a + len_a;
1580        new = b + len_b;
1581        sfx_length = 0;
1582        /*
1583         * If there is a common prefix, it must end in a slash.  In
1584         * that case we let this loop run 1 into the prefix to see the
1585         * same slash.
1586         *
1587         * If there is no common prefix, we cannot do this as it would
1588         * underrun the input strings.
1589         */
1590        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
1591        while (a + pfx_length - pfx_adjust_for_slash <= old &&
1592               b + pfx_length - pfx_adjust_for_slash <= new &&
1593               *old == *new) {
1594                if (*old == '/')
1595                        sfx_length = len_a - (old - a);
1596                old--;
1597                new--;
1598        }
1599
1600        /*
1601         * pfx{mid-a => mid-b}sfx
1602         * {pfx-a => pfx-b}sfx
1603         * pfx{sfx-a => sfx-b}
1604         * name-a => name-b
1605         */
1606        a_midlen = len_a - pfx_length - sfx_length;
1607        b_midlen = len_b - pfx_length - sfx_length;
1608        if (a_midlen < 0)
1609                a_midlen = 0;
1610        if (b_midlen < 0)
1611                b_midlen = 0;
1612
1613        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1614        if (pfx_length + sfx_length) {
1615                strbuf_add(&name, a, pfx_length);
1616                strbuf_addch(&name, '{');
1617        }
1618        strbuf_add(&name, a + pfx_length, a_midlen);
1619        strbuf_addstr(&name, " => ");
1620        strbuf_add(&name, b + pfx_length, b_midlen);
1621        if (pfx_length + sfx_length) {
1622                strbuf_addch(&name, '}');
1623                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1624        }
1625        return strbuf_detach(&name, NULL);
1626}
1627
1628struct diffstat_t {
1629        int nr;
1630        int alloc;
1631        struct diffstat_file {
1632                char *from_name;
1633                char *name;
1634                char *print_name;
1635                unsigned is_unmerged:1;
1636                unsigned is_binary:1;
1637                unsigned is_renamed:1;
1638                unsigned is_interesting:1;
1639                uintmax_t added, deleted;
1640        } **files;
1641};
1642
1643static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1644                                          const char *name_a,
1645                                          const char *name_b)
1646{
1647        struct diffstat_file *x;
1648        x = xcalloc(1, sizeof(*x));
1649        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
1650        diffstat->files[diffstat->nr++] = x;
1651        if (name_b) {
1652                x->from_name = xstrdup(name_a);
1653                x->name = xstrdup(name_b);
1654                x->is_renamed = 1;
1655        }
1656        else {
1657                x->from_name = NULL;
1658                x->name = xstrdup(name_a);
1659        }
1660        return x;
1661}
1662
1663static void diffstat_consume(void *priv, char *line, unsigned long len)
1664{
1665        struct diffstat_t *diffstat = priv;
1666        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1667
1668        if (line[0] == '+')
1669                x->added++;
1670        else if (line[0] == '-')
1671                x->deleted++;
1672}
1673
1674const char mime_boundary_leader[] = "------------";
1675
1676static int scale_linear(int it, int width, int max_change)
1677{
1678        if (!it)
1679                return 0;
1680        /*
1681         * make sure that at least one '-' or '+' is printed if
1682         * there is any change to this path. The easiest way is to
1683         * scale linearly as if the alloted width is one column shorter
1684         * than it is, and then add 1 to the result.
1685         */
1686        return 1 + (it * (width - 1) / max_change);
1687}
1688
1689static void show_name(FILE *file,
1690                      const char *prefix, const char *name, int len)
1691{
1692        fprintf(file, " %s%-*s |", prefix, len, name);
1693}
1694
1695static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1696{
1697        if (cnt <= 0)
1698                return;
1699        fprintf(file, "%s", set);
1700        while (cnt--)
1701                putc(ch, file);
1702        fprintf(file, "%s", reset);
1703}
1704
1705static void fill_print_name(struct diffstat_file *file)
1706{
1707        char *pname;
1708
1709        if (file->print_name)
1710                return;
1711
1712        if (!file->is_renamed) {
1713                struct strbuf buf = STRBUF_INIT;
1714                if (quote_c_style(file->name, &buf, NULL, 0)) {
1715                        pname = strbuf_detach(&buf, NULL);
1716                } else {
1717                        pname = file->name;
1718                        strbuf_release(&buf);
1719                }
1720        } else {
1721                pname = pprint_rename(file->from_name, file->name);
1722        }
1723        file->print_name = pname;
1724}
1725
1726int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1727{
1728        struct strbuf sb = STRBUF_INIT;
1729        int ret;
1730
1731        if (!files) {
1732                assert(insertions == 0 && deletions == 0);
1733                return fprintf(fp, "%s\n", " 0 files changed");
1734        }
1735
1736        strbuf_addf(&sb,
1737                    (files == 1) ? " %d file changed" : " %d files changed",
1738                    files);
1739
1740        /*
1741         * For binary diff, the caller may want to print "x files
1742         * changed" with insertions == 0 && deletions == 0.
1743         *
1744         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1745         * is probably less confusing (i.e skip over "2 files changed
1746         * but nothing about added/removed lines? Is this a bug in Git?").
1747         */
1748        if (insertions || deletions == 0) {
1749                strbuf_addf(&sb,
1750                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
1751                            insertions);
1752        }
1753
1754        if (deletions || insertions == 0) {
1755                strbuf_addf(&sb,
1756                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
1757                            deletions);
1758        }
1759        strbuf_addch(&sb, '\n');
1760        ret = fputs(sb.buf, fp);
1761        strbuf_release(&sb);
1762        return ret;
1763}
1764
1765static void show_stats(struct diffstat_t *data, struct diff_options *options)
1766{
1767        int i, len, add, del, adds = 0, dels = 0;
1768        uintmax_t max_change = 0, max_len = 0;
1769        int total_files = data->nr, count;
1770        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1771        const char *reset, *add_c, *del_c;
1772        const char *line_prefix = "";
1773        int extra_shown = 0;
1774
1775        if (data->nr == 0)
1776                return;
1777
1778        line_prefix = diff_line_prefix(options);
1779        count = options->stat_count ? options->stat_count : data->nr;
1780
1781        reset = diff_get_color_opt(options, DIFF_RESET);
1782        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1783        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1784
1785        /*
1786         * Find the longest filename and max number of changes
1787         */
1788        for (i = 0; (i < count) && (i < data->nr); i++) {
1789                struct diffstat_file *file = data->files[i];
1790                uintmax_t change = file->added + file->deleted;
1791
1792                if (!file->is_interesting && (change == 0)) {
1793                        count++; /* not shown == room for one more */
1794                        continue;
1795                }
1796                fill_print_name(file);
1797                len = strlen(file->print_name);
1798                if (max_len < len)
1799                        max_len = len;
1800
1801                if (file->is_unmerged) {
1802                        /* "Unmerged" is 8 characters */
1803                        bin_width = bin_width < 8 ? 8 : bin_width;
1804                        continue;
1805                }
1806                if (file->is_binary) {
1807                        /* "Bin XXX -> YYY bytes" */
1808                        int w = 14 + decimal_width(file->added)
1809                                + decimal_width(file->deleted);
1810                        bin_width = bin_width < w ? w : bin_width;
1811                        /* Display change counts aligned with "Bin" */
1812                        number_width = 3;
1813                        continue;
1814                }
1815
1816                if (max_change < change)
1817                        max_change = change;
1818        }
1819        count = i; /* where we can stop scanning in data->files[] */
1820
1821        /*
1822         * We have width = stat_width or term_columns() columns total.
1823         * We want a maximum of min(max_len, stat_name_width) for the name part.
1824         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1825         * We also need 1 for " " and 4 + decimal_width(max_change)
1826         * for " | NNNN " and one the empty column at the end, altogether
1827         * 6 + decimal_width(max_change).
1828         *
1829         * If there's not enough space, we will use the smaller of
1830         * stat_name_width (if set) and 5/8*width for the filename,
1831         * and the rest for constant elements + graph part, but no more
1832         * than stat_graph_width for the graph part.
1833         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1834         * for the standard terminal size).
1835         *
1836         * In other words: stat_width limits the maximum width, and
1837         * stat_name_width fixes the maximum width of the filename,
1838         * and is also used to divide available columns if there
1839         * aren't enough.
1840         *
1841         * Binary files are displayed with "Bin XXX -> YYY bytes"
1842         * instead of the change count and graph. This part is treated
1843         * similarly to the graph part, except that it is not
1844         * "scaled". If total width is too small to accommodate the
1845         * guaranteed minimum width of the filename part and the
1846         * separators and this message, this message will "overflow"
1847         * making the line longer than the maximum width.
1848         */
1849
1850        if (options->stat_width == -1)
1851                width = term_columns() - strlen(line_prefix);
1852        else
1853                width = options->stat_width ? options->stat_width : 80;
1854        number_width = decimal_width(max_change) > number_width ?
1855                decimal_width(max_change) : number_width;
1856
1857        if (options->stat_graph_width == -1)
1858                options->stat_graph_width = diff_stat_graph_width;
1859
1860        /*
1861         * Guarantee 3/8*16==6 for the graph part
1862         * and 5/8*16==10 for the filename part
1863         */
1864        if (width < 16 + 6 + number_width)
1865                width = 16 + 6 + number_width;
1866
1867        /*
1868         * First assign sizes that are wanted, ignoring available width.
1869         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1870         * starting from "XXX" should fit in graph_width.
1871         */
1872        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1873        if (options->stat_graph_width &&
1874            options->stat_graph_width < graph_width)
1875                graph_width = options->stat_graph_width;
1876
1877        name_width = (options->stat_name_width > 0 &&
1878                      options->stat_name_width < max_len) ?
1879                options->stat_name_width : max_len;
1880
1881        /*
1882         * Adjust adjustable widths not to exceed maximum width
1883         */
1884        if (name_width + number_width + 6 + graph_width > width) {
1885                if (graph_width > width * 3/8 - number_width - 6) {
1886                        graph_width = width * 3/8 - number_width - 6;
1887                        if (graph_width < 6)
1888                                graph_width = 6;
1889                }
1890
1891                if (options->stat_graph_width &&
1892                    graph_width > options->stat_graph_width)
1893                        graph_width = options->stat_graph_width;
1894                if (name_width > width - number_width - 6 - graph_width)
1895                        name_width = width - number_width - 6 - graph_width;
1896                else
1897                        graph_width = width - number_width - 6 - name_width;
1898        }
1899
1900        /*
1901         * From here name_width is the width of the name area,
1902         * and graph_width is the width of the graph area.
1903         * max_change is used to scale graph properly.
1904         */
1905        for (i = 0; i < count; i++) {
1906                const char *prefix = "";
1907                struct diffstat_file *file = data->files[i];
1908                char *name = file->print_name;
1909                uintmax_t added = file->added;
1910                uintmax_t deleted = file->deleted;
1911                int name_len;
1912
1913                if (!file->is_interesting && (added + deleted == 0))
1914                        continue;
1915
1916                /*
1917                 * "scale" the filename
1918                 */
1919                len = name_width;
1920                name_len = strlen(name);
1921                if (name_width < name_len) {
1922                        char *slash;
1923                        prefix = "...";
1924                        len -= 3;
1925                        name += name_len - len;
1926                        slash = strchr(name, '/');
1927                        if (slash)
1928                                name = slash;
1929                }
1930
1931                if (file->is_binary) {
1932                        fprintf(options->file, "%s", line_prefix);
1933                        show_name(options->file, prefix, name, len);
1934                        fprintf(options->file, " %*s", number_width, "Bin");
1935                        if (!added && !deleted) {
1936                                putc('\n', options->file);
1937                                continue;
1938                        }
1939                        fprintf(options->file, " %s%"PRIuMAX"%s",
1940                                del_c, deleted, reset);
1941                        fprintf(options->file, " -> ");
1942                        fprintf(options->file, "%s%"PRIuMAX"%s",
1943                                add_c, added, reset);
1944                        fprintf(options->file, " bytes");
1945                        fprintf(options->file, "\n");
1946                        continue;
1947                }
1948                else if (file->is_unmerged) {
1949                        fprintf(options->file, "%s", line_prefix);
1950                        show_name(options->file, prefix, name, len);
1951                        fprintf(options->file, " Unmerged\n");
1952                        continue;
1953                }
1954
1955                /*
1956                 * scale the add/delete
1957                 */
1958                add = added;
1959                del = deleted;
1960
1961                if (graph_width <= max_change) {
1962                        int total = scale_linear(add + del, graph_width, max_change);
1963                        if (total < 2 && add && del)
1964                                /* width >= 2 due to the sanity check */
1965                                total = 2;
1966                        if (add < del) {
1967                                add = scale_linear(add, graph_width, max_change);
1968                                del = total - add;
1969                        } else {
1970                                del = scale_linear(del, graph_width, max_change);
1971                                add = total - del;
1972                        }
1973                }
1974                fprintf(options->file, "%s", line_prefix);
1975                show_name(options->file, prefix, name, len);
1976                fprintf(options->file, " %*"PRIuMAX"%s",
1977                        number_width, added + deleted,
1978                        added + deleted ? " " : "");
1979                show_graph(options->file, '+', add, add_c, reset);
1980                show_graph(options->file, '-', del, del_c, reset);
1981                fprintf(options->file, "\n");
1982        }
1983
1984        for (i = 0; i < data->nr; i++) {
1985                struct diffstat_file *file = data->files[i];
1986                uintmax_t added = file->added;
1987                uintmax_t deleted = file->deleted;
1988
1989                if (file->is_unmerged ||
1990                    (!file->is_interesting && (added + deleted == 0))) {
1991                        total_files--;
1992                        continue;
1993                }
1994
1995                if (!file->is_binary) {
1996                        adds += added;
1997                        dels += deleted;
1998                }
1999                if (i < count)
2000                        continue;
2001                if (!extra_shown)
2002                        fprintf(options->file, "%s ...\n", line_prefix);
2003                extra_shown = 1;
2004        }
2005        fprintf(options->file, "%s", line_prefix);
2006        print_stat_summary(options->file, total_files, adds, dels);
2007}
2008
2009static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2010{
2011        int i, adds = 0, dels = 0, total_files = data->nr;
2012
2013        if (data->nr == 0)
2014                return;
2015
2016        for (i = 0; i < data->nr; i++) {
2017                int added = data->files[i]->added;
2018                int deleted= data->files[i]->deleted;
2019
2020                if (data->files[i]->is_unmerged ||
2021                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2022                        total_files--;
2023                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2024                        adds += added;
2025                        dels += deleted;
2026                }
2027        }
2028        fprintf(options->file, "%s", diff_line_prefix(options));
2029        print_stat_summary(options->file, total_files, adds, dels);
2030}
2031
2032static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2033{
2034        int i;
2035
2036        if (data->nr == 0)
2037                return;
2038
2039        for (i = 0; i < data->nr; i++) {
2040                struct diffstat_file *file = data->files[i];
2041
2042                fprintf(options->file, "%s", diff_line_prefix(options));
2043
2044                if (file->is_binary)
2045                        fprintf(options->file, "-\t-\t");
2046                else
2047                        fprintf(options->file,
2048                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2049                                file->added, file->deleted);
2050                if (options->line_termination) {
2051                        fill_print_name(file);
2052                        if (!file->is_renamed)
2053                                write_name_quoted(file->name, options->file,
2054                                                  options->line_termination);
2055                        else {
2056                                fputs(file->print_name, options->file);
2057                                putc(options->line_termination, options->file);
2058                        }
2059                } else {
2060                        if (file->is_renamed) {
2061                                putc('\0', options->file);
2062                                write_name_quoted(file->from_name, options->file, '\0');
2063                        }
2064                        write_name_quoted(file->name, options->file, '\0');
2065                }
2066        }
2067}
2068
2069struct dirstat_file {
2070        const char *name;
2071        unsigned long changed;
2072};
2073
2074struct dirstat_dir {
2075        struct dirstat_file *files;
2076        int alloc, nr, permille, cumulative;
2077};
2078
2079static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2080                unsigned long changed, const char *base, int baselen)
2081{
2082        unsigned long this_dir = 0;
2083        unsigned int sources = 0;
2084        const char *line_prefix = diff_line_prefix(opt);
2085
2086        while (dir->nr) {
2087                struct dirstat_file *f = dir->files;
2088                int namelen = strlen(f->name);
2089                unsigned long this;
2090                char *slash;
2091
2092                if (namelen < baselen)
2093                        break;
2094                if (memcmp(f->name, base, baselen))
2095                        break;
2096                slash = strchr(f->name + baselen, '/');
2097                if (slash) {
2098                        int newbaselen = slash + 1 - f->name;
2099                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2100                        sources++;
2101                } else {
2102                        this = f->changed;
2103                        dir->files++;
2104                        dir->nr--;
2105                        sources += 2;
2106                }
2107                this_dir += this;
2108        }
2109
2110        /*
2111         * We don't report dirstat's for
2112         *  - the top level
2113         *  - or cases where everything came from a single directory
2114         *    under this directory (sources == 1).
2115         */
2116        if (baselen && sources != 1) {
2117                if (this_dir) {
2118                        int permille = this_dir * 1000 / changed;
2119                        if (permille >= dir->permille) {
2120                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2121                                        permille / 10, permille % 10, baselen, base);
2122                                if (!dir->cumulative)
2123                                        return 0;
2124                        }
2125                }
2126        }
2127        return this_dir;
2128}
2129
2130static int dirstat_compare(const void *_a, const void *_b)
2131{
2132        const struct dirstat_file *a = _a;
2133        const struct dirstat_file *b = _b;
2134        return strcmp(a->name, b->name);
2135}
2136
2137static void show_dirstat(struct diff_options *options)
2138{
2139        int i;
2140        unsigned long changed;
2141        struct dirstat_dir dir;
2142        struct diff_queue_struct *q = &diff_queued_diff;
2143
2144        dir.files = NULL;
2145        dir.alloc = 0;
2146        dir.nr = 0;
2147        dir.permille = options->dirstat_permille;
2148        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2149
2150        changed = 0;
2151        for (i = 0; i < q->nr; i++) {
2152                struct diff_filepair *p = q->queue[i];
2153                const char *name;
2154                unsigned long copied, added, damage;
2155                int content_changed;
2156
2157                name = p->two->path ? p->two->path : p->one->path;
2158
2159                if (p->one->oid_valid && p->two->oid_valid)
2160                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
2161                else
2162                        content_changed = 1;
2163
2164                if (!content_changed) {
2165                        /*
2166                         * The SHA1 has not changed, so pre-/post-content is
2167                         * identical. We can therefore skip looking at the
2168                         * file contents altogether.
2169                         */
2170                        damage = 0;
2171                        goto found_damage;
2172                }
2173
2174                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
2175                        /*
2176                         * In --dirstat-by-file mode, we don't really need to
2177                         * look at the actual file contents at all.
2178                         * The fact that the SHA1 changed is enough for us to
2179                         * add this file to the list of results
2180                         * (with each file contributing equal damage).
2181                         */
2182                        damage = 1;
2183                        goto found_damage;
2184                }
2185
2186                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2187                        diff_populate_filespec(p->one, 0);
2188                        diff_populate_filespec(p->two, 0);
2189                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2190                                               &copied, &added);
2191                        diff_free_filespec_data(p->one);
2192                        diff_free_filespec_data(p->two);
2193                } else if (DIFF_FILE_VALID(p->one)) {
2194                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2195                        copied = added = 0;
2196                        diff_free_filespec_data(p->one);
2197                } else if (DIFF_FILE_VALID(p->two)) {
2198                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2199                        copied = 0;
2200                        added = p->two->size;
2201                        diff_free_filespec_data(p->two);
2202                } else
2203                        continue;
2204
2205                /*
2206                 * Original minus copied is the removed material,
2207                 * added is the new material.  They are both damages
2208                 * made to the preimage.
2209                 * If the resulting damage is zero, we know that
2210                 * diffcore_count_changes() considers the two entries to
2211                 * be identical, but since content_changed is true, we
2212                 * know that there must have been _some_ kind of change,
2213                 * so we force all entries to have damage > 0.
2214                 */
2215                damage = (p->one->size - copied) + added;
2216                if (!damage)
2217                        damage = 1;
2218
2219found_damage:
2220                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2221                dir.files[dir.nr].name = name;
2222                dir.files[dir.nr].changed = damage;
2223                changed += damage;
2224                dir.nr++;
2225        }
2226
2227        /* This can happen even with many files, if everything was renames */
2228        if (!changed)
2229                return;
2230
2231        /* Show all directories with more than x% of the changes */
2232        QSORT(dir.files, dir.nr, dirstat_compare);
2233        gather_dirstat(options, &dir, changed, "", 0);
2234}
2235
2236static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2237{
2238        int i;
2239        unsigned long changed;
2240        struct dirstat_dir dir;
2241
2242        if (data->nr == 0)
2243                return;
2244
2245        dir.files = NULL;
2246        dir.alloc = 0;
2247        dir.nr = 0;
2248        dir.permille = options->dirstat_permille;
2249        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2250
2251        changed = 0;
2252        for (i = 0; i < data->nr; i++) {
2253                struct diffstat_file *file = data->files[i];
2254                unsigned long damage = file->added + file->deleted;
2255                if (file->is_binary)
2256                        /*
2257                         * binary files counts bytes, not lines. Must find some
2258                         * way to normalize binary bytes vs. textual lines.
2259                         * The following heuristic assumes that there are 64
2260                         * bytes per "line".
2261                         * This is stupid and ugly, but very cheap...
2262                         */
2263                        damage = (damage + 63) / 64;
2264                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2265                dir.files[dir.nr].name = file->name;
2266                dir.files[dir.nr].changed = damage;
2267                changed += damage;
2268                dir.nr++;
2269        }
2270
2271        /* This can happen even with many files, if everything was renames */
2272        if (!changed)
2273                return;
2274
2275        /* Show all directories with more than x% of the changes */
2276        QSORT(dir.files, dir.nr, dirstat_compare);
2277        gather_dirstat(options, &dir, changed, "", 0);
2278}
2279
2280static void free_diffstat_info(struct diffstat_t *diffstat)
2281{
2282        int i;
2283        for (i = 0; i < diffstat->nr; i++) {
2284                struct diffstat_file *f = diffstat->files[i];
2285                if (f->name != f->print_name)
2286                        free(f->print_name);
2287                free(f->name);
2288                free(f->from_name);
2289                free(f);
2290        }
2291        free(diffstat->files);
2292}
2293
2294struct checkdiff_t {
2295        const char *filename;
2296        int lineno;
2297        int conflict_marker_size;
2298        struct diff_options *o;
2299        unsigned ws_rule;
2300        unsigned status;
2301};
2302
2303static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2304{
2305        char firstchar;
2306        int cnt;
2307
2308        if (len < marker_size + 1)
2309                return 0;
2310        firstchar = line[0];
2311        switch (firstchar) {
2312        case '=': case '>': case '<': case '|':
2313                break;
2314        default:
2315                return 0;
2316        }
2317        for (cnt = 1; cnt < marker_size; cnt++)
2318                if (line[cnt] != firstchar)
2319                        return 0;
2320        /* line[1] thru line[marker_size-1] are same as firstchar */
2321        if (len < marker_size + 1 || !isspace(line[marker_size]))
2322                return 0;
2323        return 1;
2324}
2325
2326static void checkdiff_consume(void *priv, char *line, unsigned long len)
2327{
2328        struct checkdiff_t *data = priv;
2329        int marker_size = data->conflict_marker_size;
2330        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2331        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2332        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2333        char *err;
2334        const char *line_prefix;
2335
2336        assert(data->o);
2337        line_prefix = diff_line_prefix(data->o);
2338
2339        if (line[0] == '+') {
2340                unsigned bad;
2341                data->lineno++;
2342                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2343                        data->status |= 1;
2344                        fprintf(data->o->file,
2345                                "%s%s:%d: leftover conflict marker\n",
2346                                line_prefix, data->filename, data->lineno);
2347                }
2348                bad = ws_check(line + 1, len - 1, data->ws_rule);
2349                if (!bad)
2350                        return;
2351                data->status |= bad;
2352                err = whitespace_error_string(bad);
2353                fprintf(data->o->file, "%s%s:%d: %s.\n",
2354                        line_prefix, data->filename, data->lineno, err);
2355                free(err);
2356                emit_line(data->o, set, reset, line, 1);
2357                ws_check_emit(line + 1, len - 1, data->ws_rule,
2358                              data->o->file, set, reset, ws);
2359        } else if (line[0] == ' ') {
2360                data->lineno++;
2361        } else if (line[0] == '@') {
2362                char *plus = strchr(line, '+');
2363                if (plus)
2364                        data->lineno = strtol(plus, NULL, 10) - 1;
2365                else
2366                        die("invalid diff");
2367        }
2368}
2369
2370static unsigned char *deflate_it(char *data,
2371                                 unsigned long size,
2372                                 unsigned long *result_size)
2373{
2374        int bound;
2375        unsigned char *deflated;
2376        git_zstream stream;
2377
2378        git_deflate_init(&stream, zlib_compression_level);
2379        bound = git_deflate_bound(&stream, size);
2380        deflated = xmalloc(bound);
2381        stream.next_out = deflated;
2382        stream.avail_out = bound;
2383
2384        stream.next_in = (unsigned char *)data;
2385        stream.avail_in = size;
2386        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2387                ; /* nothing */
2388        git_deflate_end(&stream);
2389        *result_size = stream.total_out;
2390        return deflated;
2391}
2392
2393static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two,
2394                                  const char *prefix)
2395{
2396        void *cp;
2397        void *delta;
2398        void *deflated;
2399        void *data;
2400        unsigned long orig_size;
2401        unsigned long delta_size;
2402        unsigned long deflate_size;
2403        unsigned long data_size;
2404
2405        /* We could do deflated delta, or we could do just deflated two,
2406         * whichever is smaller.
2407         */
2408        delta = NULL;
2409        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2410        if (one->size && two->size) {
2411                delta = diff_delta(one->ptr, one->size,
2412                                   two->ptr, two->size,
2413                                   &delta_size, deflate_size);
2414                if (delta) {
2415                        void *to_free = delta;
2416                        orig_size = delta_size;
2417                        delta = deflate_it(delta, delta_size, &delta_size);
2418                        free(to_free);
2419                }
2420        }
2421
2422        if (delta && delta_size < deflate_size) {
2423                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2424                free(deflated);
2425                data = delta;
2426                data_size = delta_size;
2427        }
2428        else {
2429                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2430                free(delta);
2431                data = deflated;
2432                data_size = deflate_size;
2433        }
2434
2435        /* emit data encoded in base85 */
2436        cp = data;
2437        while (data_size) {
2438                int bytes = (52 < data_size) ? 52 : data_size;
2439                char line[70];
2440                data_size -= bytes;
2441                if (bytes <= 26)
2442                        line[0] = bytes + 'A' - 1;
2443                else
2444                        line[0] = bytes - 26 + 'a' - 1;
2445                encode_85(line + 1, cp, bytes);
2446                cp = (char *) cp + bytes;
2447                fprintf(file, "%s", prefix);
2448                fputs(line, file);
2449                fputc('\n', file);
2450        }
2451        fprintf(file, "%s\n", prefix);
2452        free(data);
2453}
2454
2455static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two,
2456                             const char *prefix)
2457{
2458        fprintf(file, "%sGIT binary patch\n", prefix);
2459        emit_binary_diff_body(file, one, two, prefix);
2460        emit_binary_diff_body(file, two, one, prefix);
2461}
2462
2463int diff_filespec_is_binary(struct diff_filespec *one)
2464{
2465        if (one->is_binary == -1) {
2466                diff_filespec_load_driver(one);
2467                if (one->driver->binary != -1)
2468                        one->is_binary = one->driver->binary;
2469                else {
2470                        if (!one->data && DIFF_FILE_VALID(one))
2471                                diff_populate_filespec(one, CHECK_BINARY);
2472                        if (one->is_binary == -1 && one->data)
2473                                one->is_binary = buffer_is_binary(one->data,
2474                                                one->size);
2475                        if (one->is_binary == -1)
2476                                one->is_binary = 0;
2477                }
2478        }
2479        return one->is_binary;
2480}
2481
2482static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2483{
2484        diff_filespec_load_driver(one);
2485        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2486}
2487
2488void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2489{
2490        if (!options->a_prefix)
2491                options->a_prefix = a;
2492        if (!options->b_prefix)
2493                options->b_prefix = b;
2494}
2495
2496struct userdiff_driver *get_textconv(struct diff_filespec *one)
2497{
2498        if (!DIFF_FILE_VALID(one))
2499                return NULL;
2500
2501        diff_filespec_load_driver(one);
2502        return userdiff_get_textconv(one->driver);
2503}
2504
2505static void builtin_diff(const char *name_a,
2506                         const char *name_b,
2507                         struct diff_filespec *one,
2508                         struct diff_filespec *two,
2509                         const char *xfrm_msg,
2510                         int must_show_header,
2511                         struct diff_options *o,
2512                         int complete_rewrite)
2513{
2514        mmfile_t mf1, mf2;
2515        const char *lbl[2];
2516        char *a_one, *b_two;
2517        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
2518        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2519        const char *a_prefix, *b_prefix;
2520        struct userdiff_driver *textconv_one = NULL;
2521        struct userdiff_driver *textconv_two = NULL;
2522        struct strbuf header = STRBUF_INIT;
2523        const char *line_prefix = diff_line_prefix(o);
2524
2525        diff_set_mnemonic_prefix(o, "a/", "b/");
2526        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2527                a_prefix = o->b_prefix;
2528                b_prefix = o->a_prefix;
2529        } else {
2530                a_prefix = o->a_prefix;
2531                b_prefix = o->b_prefix;
2532        }
2533
2534        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
2535            (!one->mode || S_ISGITLINK(one->mode)) &&
2536            (!two->mode || S_ISGITLINK(two->mode))) {
2537                show_submodule_summary(o, one->path ? one->path : two->path,
2538                                &one->oid, &two->oid,
2539                                two->dirty_submodule);
2540                return;
2541        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
2542                   (!one->mode || S_ISGITLINK(one->mode)) &&
2543                   (!two->mode || S_ISGITLINK(two->mode))) {
2544                show_submodule_inline_diff(o, one->path ? one->path : two->path,
2545                                &one->oid, &two->oid,
2546                                two->dirty_submodule);
2547                return;
2548        }
2549
2550        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2551                textconv_one = get_textconv(one);
2552                textconv_two = get_textconv(two);
2553        }
2554
2555        /* Never use a non-valid filename anywhere if at all possible */
2556        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2557        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2558
2559        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2560        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2561        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2562        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2563        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
2564        if (lbl[0][0] == '/') {
2565                /* /dev/null */
2566                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
2567                if (xfrm_msg)
2568                        strbuf_addstr(&header, xfrm_msg);
2569                must_show_header = 1;
2570        }
2571        else if (lbl[1][0] == '/') {
2572                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
2573                if (xfrm_msg)
2574                        strbuf_addstr(&header, xfrm_msg);
2575                must_show_header = 1;
2576        }
2577        else {
2578                if (one->mode != two->mode) {
2579                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
2580                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
2581                        must_show_header = 1;
2582                }
2583                if (xfrm_msg)
2584                        strbuf_addstr(&header, xfrm_msg);
2585
2586                /*
2587                 * we do not run diff between different kind
2588                 * of objects.
2589                 */
2590                if ((one->mode ^ two->mode) & S_IFMT)
2591                        goto free_ab_and_return;
2592                if (complete_rewrite &&
2593                    (textconv_one || !diff_filespec_is_binary(one)) &&
2594                    (textconv_two || !diff_filespec_is_binary(two))) {
2595                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2596                                         header.buf, header.len, 0);
2597                        strbuf_reset(&header);
2598                        emit_rewrite_diff(name_a, name_b, one, two,
2599                                                textconv_one, textconv_two, o);
2600                        o->found_changes = 1;
2601                        goto free_ab_and_return;
2602                }
2603        }
2604
2605        if (o->irreversible_delete && lbl[1][0] == '/') {
2606                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
2607                                 header.len, 0);
2608                strbuf_reset(&header);
2609                goto free_ab_and_return;
2610        } else if (!DIFF_OPT_TST(o, TEXT) &&
2611            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2612              (!textconv_two && diff_filespec_is_binary(two)) )) {
2613                struct strbuf sb = STRBUF_INIT;
2614                if (!one->data && !two->data &&
2615                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
2616                    !DIFF_OPT_TST(o, BINARY)) {
2617                        if (!oidcmp(&one->oid, &two->oid)) {
2618                                if (must_show_header)
2619                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2620                                                         header.buf, header.len,
2621                                                         0);
2622                                goto free_ab_and_return;
2623                        }
2624                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2625                                         header.buf, header.len, 0);
2626                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
2627                                    diff_line_prefix(o), lbl[0], lbl[1]);
2628                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
2629                                         sb.buf, sb.len, 0);
2630                        strbuf_release(&sb);
2631                        goto free_ab_and_return;
2632                }
2633                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2634                        die("unable to read files to diff");
2635                /* Quite common confusing case */
2636                if (mf1.size == mf2.size &&
2637                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2638                        if (must_show_header)
2639                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2640                                                 header.buf, header.len, 0);
2641                        goto free_ab_and_return;
2642                }
2643                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
2644                strbuf_reset(&header);
2645                if (DIFF_OPT_TST(o, BINARY))
2646                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2647                else {
2648                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
2649                                    diff_line_prefix(o), lbl[0], lbl[1]);
2650                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
2651                                         sb.buf, sb.len, 0);
2652                        strbuf_release(&sb);
2653                }
2654                o->found_changes = 1;
2655        } else {
2656                /* Crazy xdl interfaces.. */
2657                const char *diffopts = getenv("GIT_DIFF_OPTS");
2658                const char *v;
2659                xpparam_t xpp;
2660                xdemitconf_t xecfg;
2661                struct emit_callback ecbdata;
2662                const struct userdiff_funcname *pe;
2663
2664                if (must_show_header) {
2665                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2666                                         header.buf, header.len, 0);
2667                        strbuf_reset(&header);
2668                }
2669
2670                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2671                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2672
2673                pe = diff_funcname_pattern(one);
2674                if (!pe)
2675                        pe = diff_funcname_pattern(two);
2676
2677                memset(&xpp, 0, sizeof(xpp));
2678                memset(&xecfg, 0, sizeof(xecfg));
2679                memset(&ecbdata, 0, sizeof(ecbdata));
2680                ecbdata.label_path = lbl;
2681                ecbdata.color_diff = want_color(o->use_color);
2682                ecbdata.ws_rule = whitespace_rule(name_b);
2683                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2684                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2685                ecbdata.opt = o;
2686                ecbdata.header = header.len ? &header : NULL;
2687                xpp.flags = o->xdl_opts;
2688                xecfg.ctxlen = o->context;
2689                xecfg.interhunkctxlen = o->interhunkcontext;
2690                xecfg.flags = XDL_EMIT_FUNCNAMES;
2691                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2692                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2693                if (pe)
2694                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2695                if (!diffopts)
2696                        ;
2697                else if (skip_prefix(diffopts, "--unified=", &v))
2698                        xecfg.ctxlen = strtoul(v, NULL, 10);
2699                else if (skip_prefix(diffopts, "-u", &v))
2700                        xecfg.ctxlen = strtoul(v, NULL, 10);
2701                if (o->word_diff)
2702                        init_diff_words_data(&ecbdata, o, one, two);
2703                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2704                                  &xpp, &xecfg))
2705                        die("unable to generate diff for %s", one->path);
2706                if (o->word_diff)
2707                        free_diff_words_data(&ecbdata);
2708                if (textconv_one)
2709                        free(mf1.ptr);
2710                if (textconv_two)
2711                        free(mf2.ptr);
2712                xdiff_clear_find_func(&xecfg);
2713        }
2714
2715 free_ab_and_return:
2716        strbuf_release(&header);
2717        diff_free_filespec_data(one);
2718        diff_free_filespec_data(two);
2719        free(a_one);
2720        free(b_two);
2721        return;
2722}
2723
2724static void builtin_diffstat(const char *name_a, const char *name_b,
2725                             struct diff_filespec *one,
2726                             struct diff_filespec *two,
2727                             struct diffstat_t *diffstat,
2728                             struct diff_options *o,
2729                             struct diff_filepair *p)
2730{
2731        mmfile_t mf1, mf2;
2732        struct diffstat_file *data;
2733        int same_contents;
2734        int complete_rewrite = 0;
2735
2736        if (!DIFF_PAIR_UNMERGED(p)) {
2737                if (p->status == DIFF_STATUS_MODIFIED && p->score)
2738                        complete_rewrite = 1;
2739        }
2740
2741        data = diffstat_add(diffstat, name_a, name_b);
2742        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
2743
2744        if (!one || !two) {
2745                data->is_unmerged = 1;
2746                return;
2747        }
2748
2749        same_contents = !oidcmp(&one->oid, &two->oid);
2750
2751        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2752                data->is_binary = 1;
2753                if (same_contents) {
2754                        data->added = 0;
2755                        data->deleted = 0;
2756                } else {
2757                        data->added = diff_filespec_size(two);
2758                        data->deleted = diff_filespec_size(one);
2759                }
2760        }
2761
2762        else if (complete_rewrite) {
2763                diff_populate_filespec(one, 0);
2764                diff_populate_filespec(two, 0);
2765                data->deleted = count_lines(one->data, one->size);
2766                data->added = count_lines(two->data, two->size);
2767        }
2768
2769        else if (!same_contents) {
2770                /* Crazy xdl interfaces.. */
2771                xpparam_t xpp;
2772                xdemitconf_t xecfg;
2773
2774                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2775                        die("unable to read files to diff");
2776
2777                memset(&xpp, 0, sizeof(xpp));
2778                memset(&xecfg, 0, sizeof(xecfg));
2779                xpp.flags = o->xdl_opts;
2780                xecfg.ctxlen = o->context;
2781                xecfg.interhunkctxlen = o->interhunkcontext;
2782                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2783                                  &xpp, &xecfg))
2784                        die("unable to generate diffstat for %s", one->path);
2785        }
2786
2787        diff_free_filespec_data(one);
2788        diff_free_filespec_data(two);
2789}
2790
2791static void builtin_checkdiff(const char *name_a, const char *name_b,
2792                              const char *attr_path,
2793                              struct diff_filespec *one,
2794                              struct diff_filespec *two,
2795                              struct diff_options *o)
2796{
2797        mmfile_t mf1, mf2;
2798        struct checkdiff_t data;
2799
2800        if (!two)
2801                return;
2802
2803        memset(&data, 0, sizeof(data));
2804        data.filename = name_b ? name_b : name_a;
2805        data.lineno = 0;
2806        data.o = o;
2807        data.ws_rule = whitespace_rule(attr_path);
2808        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2809
2810        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2811                die("unable to read files to diff");
2812
2813        /*
2814         * All the other codepaths check both sides, but not checking
2815         * the "old" side here is deliberate.  We are checking the newly
2816         * introduced changes, and as long as the "new" side is text, we
2817         * can and should check what it introduces.
2818         */
2819        if (diff_filespec_is_binary(two))
2820                goto free_and_return;
2821        else {
2822                /* Crazy xdl interfaces.. */
2823                xpparam_t xpp;
2824                xdemitconf_t xecfg;
2825
2826                memset(&xpp, 0, sizeof(xpp));
2827                memset(&xecfg, 0, sizeof(xecfg));
2828                xecfg.ctxlen = 1; /* at least one context line */
2829                xpp.flags = 0;
2830                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2831                                  &xpp, &xecfg))
2832                        die("unable to generate checkdiff for %s", one->path);
2833
2834                if (data.ws_rule & WS_BLANK_AT_EOF) {
2835                        struct emit_callback ecbdata;
2836                        int blank_at_eof;
2837
2838                        ecbdata.ws_rule = data.ws_rule;
2839                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2840                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2841
2842                        if (blank_at_eof) {
2843                                static char *err;
2844                                if (!err)
2845                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2846                                fprintf(o->file, "%s:%d: %s.\n",
2847                                        data.filename, blank_at_eof, err);
2848                                data.status = 1; /* report errors */
2849                        }
2850                }
2851        }
2852 free_and_return:
2853        diff_free_filespec_data(one);
2854        diff_free_filespec_data(two);
2855        if (data.status)
2856                DIFF_OPT_SET(o, CHECK_FAILED);
2857}
2858
2859struct diff_filespec *alloc_filespec(const char *path)
2860{
2861        struct diff_filespec *spec;
2862
2863        FLEXPTR_ALLOC_STR(spec, path, path);
2864        spec->count = 1;
2865        spec->is_binary = -1;
2866        return spec;
2867}
2868
2869void free_filespec(struct diff_filespec *spec)
2870{
2871        if (!--spec->count) {
2872                diff_free_filespec_data(spec);
2873                free(spec);
2874        }
2875}
2876
2877void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
2878                   int oid_valid, unsigned short mode)
2879{
2880        if (mode) {
2881                spec->mode = canon_mode(mode);
2882                oidcpy(&spec->oid, oid);
2883                spec->oid_valid = oid_valid;
2884        }
2885}
2886
2887/*
2888 * Given a name and sha1 pair, if the index tells us the file in
2889 * the work tree has that object contents, return true, so that
2890 * prepare_temp_file() does not have to inflate and extract.
2891 */
2892static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
2893{
2894        const struct cache_entry *ce;
2895        struct stat st;
2896        int pos, len;
2897
2898        /*
2899         * We do not read the cache ourselves here, because the
2900         * benchmark with my previous version that always reads cache
2901         * shows that it makes things worse for diff-tree comparing
2902         * two linux-2.6 kernel trees in an already checked out work
2903         * tree.  This is because most diff-tree comparisons deal with
2904         * only a small number of files, while reading the cache is
2905         * expensive for a large project, and its cost outweighs the
2906         * savings we get by not inflating the object to a temporary
2907         * file.  Practically, this code only helps when we are used
2908         * by diff-cache --cached, which does read the cache before
2909         * calling us.
2910         */
2911        if (!active_cache)
2912                return 0;
2913
2914        /* We want to avoid the working directory if our caller
2915         * doesn't need the data in a normal file, this system
2916         * is rather slow with its stat/open/mmap/close syscalls,
2917         * and the object is contained in a pack file.  The pack
2918         * is probably already open and will be faster to obtain
2919         * the data through than the working directory.  Loose
2920         * objects however would tend to be slower as they need
2921         * to be individually opened and inflated.
2922         */
2923        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(oid->hash))
2924                return 0;
2925
2926        /*
2927         * Similarly, if we'd have to convert the file contents anyway, that
2928         * makes the optimization not worthwhile.
2929         */
2930        if (!want_file && would_convert_to_git(&the_index, name))
2931                return 0;
2932
2933        len = strlen(name);
2934        pos = cache_name_pos(name, len);
2935        if (pos < 0)
2936                return 0;
2937        ce = active_cache[pos];
2938
2939        /*
2940         * This is not the sha1 we are looking for, or
2941         * unreusable because it is not a regular file.
2942         */
2943        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
2944                return 0;
2945
2946        /*
2947         * If ce is marked as "assume unchanged", there is no
2948         * guarantee that work tree matches what we are looking for.
2949         */
2950        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2951                return 0;
2952
2953        /*
2954         * If ce matches the file in the work tree, we can reuse it.
2955         */
2956        if (ce_uptodate(ce) ||
2957            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2958                return 1;
2959
2960        return 0;
2961}
2962
2963static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2964{
2965        struct strbuf buf = STRBUF_INIT;
2966        char *dirty = "";
2967
2968        /* Are we looking at the work tree? */
2969        if (s->dirty_submodule)
2970                dirty = "-dirty";
2971
2972        strbuf_addf(&buf, "Subproject commit %s%s\n",
2973                    oid_to_hex(&s->oid), dirty);
2974        s->size = buf.len;
2975        if (size_only) {
2976                s->data = NULL;
2977                strbuf_release(&buf);
2978        } else {
2979                s->data = strbuf_detach(&buf, NULL);
2980                s->should_free = 1;
2981        }
2982        return 0;
2983}
2984
2985/*
2986 * While doing rename detection and pickaxe operation, we may need to
2987 * grab the data for the blob (or file) for our own in-core comparison.
2988 * diff_filespec has data and size fields for this purpose.
2989 */
2990int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
2991{
2992        int size_only = flags & CHECK_SIZE_ONLY;
2993        int err = 0;
2994        /*
2995         * demote FAIL to WARN to allow inspecting the situation
2996         * instead of refusing.
2997         */
2998        enum safe_crlf crlf_warn = (safe_crlf == SAFE_CRLF_FAIL
2999                                    ? SAFE_CRLF_WARN
3000                                    : safe_crlf);
3001
3002        if (!DIFF_FILE_VALID(s))
3003                die("internal error: asking to populate invalid file.");
3004        if (S_ISDIR(s->mode))
3005                return -1;
3006
3007        if (s->data)
3008                return 0;
3009
3010        if (size_only && 0 < s->size)
3011                return 0;
3012
3013        if (S_ISGITLINK(s->mode))
3014                return diff_populate_gitlink(s, size_only);
3015
3016        if (!s->oid_valid ||
3017            reuse_worktree_file(s->path, &s->oid, 0)) {
3018                struct strbuf buf = STRBUF_INIT;
3019                struct stat st;
3020                int fd;
3021
3022                if (lstat(s->path, &st) < 0) {
3023                        if (errno == ENOENT) {
3024                        err_empty:
3025                                err = -1;
3026                        empty:
3027                                s->data = (char *)"";
3028                                s->size = 0;
3029                                return err;
3030                        }
3031                }
3032                s->size = xsize_t(st.st_size);
3033                if (!s->size)
3034                        goto empty;
3035                if (S_ISLNK(st.st_mode)) {
3036                        struct strbuf sb = STRBUF_INIT;
3037
3038                        if (strbuf_readlink(&sb, s->path, s->size))
3039                                goto err_empty;
3040                        s->size = sb.len;
3041                        s->data = strbuf_detach(&sb, NULL);
3042                        s->should_free = 1;
3043                        return 0;
3044                }
3045
3046                /*
3047                 * Even if the caller would be happy with getting
3048                 * only the size, we cannot return early at this
3049                 * point if the path requires us to run the content
3050                 * conversion.
3051                 */
3052                if (size_only && !would_convert_to_git(&the_index, s->path))
3053                        return 0;
3054
3055                /*
3056                 * Note: this check uses xsize_t(st.st_size) that may
3057                 * not be the true size of the blob after it goes
3058                 * through convert_to_git().  This may not strictly be
3059                 * correct, but the whole point of big_file_threshold
3060                 * and is_binary check being that we want to avoid
3061                 * opening the file and inspecting the contents, this
3062                 * is probably fine.
3063                 */
3064                if ((flags & CHECK_BINARY) &&
3065                    s->size > big_file_threshold && s->is_binary == -1) {
3066                        s->is_binary = 1;
3067                        return 0;
3068                }
3069                fd = open(s->path, O_RDONLY);
3070                if (fd < 0)
3071                        goto err_empty;
3072                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3073                close(fd);
3074                s->should_munmap = 1;
3075
3076                /*
3077                 * Convert from working tree format to canonical git format
3078                 */
3079                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, crlf_warn)) {
3080                        size_t size = 0;
3081                        munmap(s->data, s->size);
3082                        s->should_munmap = 0;
3083                        s->data = strbuf_detach(&buf, &size);
3084                        s->size = size;
3085                        s->should_free = 1;
3086                }
3087        }
3088        else {
3089                enum object_type type;
3090                if (size_only || (flags & CHECK_BINARY)) {
3091                        type = sha1_object_info(s->oid.hash, &s->size);
3092                        if (type < 0)
3093                                die("unable to read %s",
3094                                    oid_to_hex(&s->oid));
3095                        if (size_only)
3096                                return 0;
3097                        if (s->size > big_file_threshold && s->is_binary == -1) {
3098                                s->is_binary = 1;
3099                                return 0;
3100                        }
3101                }
3102                s->data = read_sha1_file(s->oid.hash, &type, &s->size);
3103                if (!s->data)
3104                        die("unable to read %s", oid_to_hex(&s->oid));
3105                s->should_free = 1;
3106        }
3107        return 0;
3108}
3109
3110void diff_free_filespec_blob(struct diff_filespec *s)
3111{
3112        if (s->should_free)
3113                free(s->data);
3114        else if (s->should_munmap)
3115                munmap(s->data, s->size);
3116
3117        if (s->should_free || s->should_munmap) {
3118                s->should_free = s->should_munmap = 0;
3119                s->data = NULL;
3120        }
3121}
3122
3123void diff_free_filespec_data(struct diff_filespec *s)
3124{
3125        diff_free_filespec_blob(s);
3126        FREE_AND_NULL(s->cnt_data);
3127}
3128
3129static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
3130                           void *blob,
3131                           unsigned long size,
3132                           const struct object_id *oid,
3133                           int mode)
3134{
3135        int fd;
3136        struct strbuf buf = STRBUF_INIT;
3137        struct strbuf template = STRBUF_INIT;
3138        char *path_dup = xstrdup(path);
3139        const char *base = basename(path_dup);
3140
3141        /* Generate "XXXXXX_basename.ext" */
3142        strbuf_addstr(&template, "XXXXXX_");
3143        strbuf_addstr(&template, base);
3144
3145        fd = mks_tempfile_ts(&temp->tempfile, template.buf, strlen(base) + 1);
3146        if (fd < 0)
3147                die_errno("unable to create temp-file");
3148        if (convert_to_working_tree(path,
3149                        (const char *)blob, (size_t)size, &buf)) {
3150                blob = buf.buf;
3151                size = buf.len;
3152        }
3153        if (write_in_full(fd, blob, size) != size)
3154                die_errno("unable to write temp-file");
3155        close_tempfile(&temp->tempfile);
3156        temp->name = get_tempfile_path(&temp->tempfile);
3157        oid_to_hex_r(temp->hex, oid);
3158        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3159        strbuf_release(&buf);
3160        strbuf_release(&template);
3161        free(path_dup);
3162}
3163
3164static struct diff_tempfile *prepare_temp_file(const char *name,
3165                struct diff_filespec *one)
3166{
3167        struct diff_tempfile *temp = claim_diff_tempfile();
3168
3169        if (!DIFF_FILE_VALID(one)) {
3170        not_a_valid_file:
3171                /* A '-' entry produces this for file-2, and
3172                 * a '+' entry produces this for file-1.
3173                 */
3174                temp->name = "/dev/null";
3175                xsnprintf(temp->hex, sizeof(temp->hex), ".");
3176                xsnprintf(temp->mode, sizeof(temp->mode), ".");
3177                return temp;
3178        }
3179
3180        if (!S_ISGITLINK(one->mode) &&
3181            (!one->oid_valid ||
3182             reuse_worktree_file(name, &one->oid, 1))) {
3183                struct stat st;
3184                if (lstat(name, &st) < 0) {
3185                        if (errno == ENOENT)
3186                                goto not_a_valid_file;
3187                        die_errno("stat(%s)", name);
3188                }
3189                if (S_ISLNK(st.st_mode)) {
3190                        struct strbuf sb = STRBUF_INIT;
3191                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
3192                                die_errno("readlink(%s)", name);
3193                        prep_temp_blob(name, temp, sb.buf, sb.len,
3194                                       (one->oid_valid ?
3195                                        &one->oid : &null_oid),
3196                                       (one->oid_valid ?
3197                                        one->mode : S_IFLNK));
3198                        strbuf_release(&sb);
3199                }
3200                else {
3201                        /* we can borrow from the file in the work tree */
3202                        temp->name = name;
3203                        if (!one->oid_valid)
3204                                oid_to_hex_r(temp->hex, &null_oid);
3205                        else
3206                                oid_to_hex_r(temp->hex, &one->oid);
3207                        /* Even though we may sometimes borrow the
3208                         * contents from the work tree, we always want
3209                         * one->mode.  mode is trustworthy even when
3210                         * !(one->oid_valid), as long as
3211                         * DIFF_FILE_VALID(one).
3212                         */
3213                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
3214                }
3215                return temp;
3216        }
3217        else {
3218                if (diff_populate_filespec(one, 0))
3219                        die("cannot read data blob for %s", one->path);
3220                prep_temp_blob(name, temp, one->data, one->size,
3221                               &one->oid, one->mode);
3222        }
3223        return temp;
3224}
3225
3226static void add_external_diff_name(struct argv_array *argv,
3227                                   const char *name,
3228                                   struct diff_filespec *df)
3229{
3230        struct diff_tempfile *temp = prepare_temp_file(name, df);
3231        argv_array_push(argv, temp->name);
3232        argv_array_push(argv, temp->hex);
3233        argv_array_push(argv, temp->mode);
3234}
3235
3236/* An external diff command takes:
3237 *
3238 * diff-cmd name infile1 infile1-sha1 infile1-mode \
3239 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
3240 *
3241 */
3242static void run_external_diff(const char *pgm,
3243                              const char *name,
3244                              const char *other,
3245                              struct diff_filespec *one,
3246                              struct diff_filespec *two,
3247                              const char *xfrm_msg,
3248                              int complete_rewrite,
3249                              struct diff_options *o)
3250{
3251        struct argv_array argv = ARGV_ARRAY_INIT;
3252        struct argv_array env = ARGV_ARRAY_INIT;
3253        struct diff_queue_struct *q = &diff_queued_diff;
3254
3255        argv_array_push(&argv, pgm);
3256        argv_array_push(&argv, name);
3257
3258        if (one && two) {
3259                add_external_diff_name(&argv, name, one);
3260                if (!other)
3261                        add_external_diff_name(&argv, name, two);
3262                else {
3263                        add_external_diff_name(&argv, other, two);
3264                        argv_array_push(&argv, other);
3265                        argv_array_push(&argv, xfrm_msg);
3266                }
3267        }
3268
3269        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
3270        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
3271
3272        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
3273                die(_("external diff died, stopping at %s"), name);
3274
3275        remove_tempfile();
3276        argv_array_clear(&argv);
3277        argv_array_clear(&env);
3278}
3279
3280static int similarity_index(struct diff_filepair *p)
3281{
3282        return p->score * 100 / MAX_SCORE;
3283}
3284
3285static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
3286{
3287        if (startup_info->have_repository)
3288                return find_unique_abbrev(oid->hash, abbrev);
3289        else {
3290                char *hex = oid_to_hex(oid);
3291                if (abbrev < 0)
3292                        abbrev = FALLBACK_DEFAULT_ABBREV;
3293                if (abbrev > GIT_SHA1_HEXSZ)
3294                        die("BUG: oid abbreviation out of range: %d", abbrev);
3295                if (abbrev)
3296                        hex[abbrev] = '\0';
3297                return hex;
3298        }
3299}
3300
3301static void fill_metainfo(struct strbuf *msg,
3302                          const char *name,
3303                          const char *other,
3304                          struct diff_filespec *one,
3305                          struct diff_filespec *two,
3306                          struct diff_options *o,
3307                          struct diff_filepair *p,
3308                          int *must_show_header,
3309                          int use_color)
3310{
3311        const char *set = diff_get_color(use_color, DIFF_METAINFO);
3312        const char *reset = diff_get_color(use_color, DIFF_RESET);
3313        const char *line_prefix = diff_line_prefix(o);
3314
3315        *must_show_header = 1;
3316        strbuf_init(msg, PATH_MAX * 2 + 300);
3317        switch (p->status) {
3318        case DIFF_STATUS_COPIED:
3319                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3320                            line_prefix, set, similarity_index(p));
3321                strbuf_addf(msg, "%s\n%s%scopy from ",
3322                            reset,  line_prefix, set);
3323                quote_c_style(name, msg, NULL, 0);
3324                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3325                quote_c_style(other, msg, NULL, 0);
3326                strbuf_addf(msg, "%s\n", reset);
3327                break;
3328        case DIFF_STATUS_RENAMED:
3329                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3330                            line_prefix, set, similarity_index(p));
3331                strbuf_addf(msg, "%s\n%s%srename from ",
3332                            reset, line_prefix, set);
3333                quote_c_style(name, msg, NULL, 0);
3334                strbuf_addf(msg, "%s\n%s%srename to ",
3335                            reset, line_prefix, set);
3336                quote_c_style(other, msg, NULL, 0);
3337                strbuf_addf(msg, "%s\n", reset);
3338                break;
3339        case DIFF_STATUS_MODIFIED:
3340                if (p->score) {
3341                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3342                                    line_prefix,
3343                                    set, similarity_index(p), reset);
3344                        break;
3345                }
3346                /* fallthru */
3347        default:
3348                *must_show_header = 0;
3349        }
3350        if (one && two && oidcmp(&one->oid, &two->oid)) {
3351                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
3352
3353                if (DIFF_OPT_TST(o, BINARY)) {
3354                        mmfile_t mf;
3355                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3356                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3357                                abbrev = 40;
3358                }
3359                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
3360                            diff_abbrev_oid(&one->oid, abbrev),
3361                            diff_abbrev_oid(&two->oid, abbrev));
3362                if (one->mode == two->mode)
3363                        strbuf_addf(msg, " %06o", one->mode);
3364                strbuf_addf(msg, "%s\n", reset);
3365        }
3366}
3367
3368static void run_diff_cmd(const char *pgm,
3369                         const char *name,
3370                         const char *other,
3371                         const char *attr_path,
3372                         struct diff_filespec *one,
3373                         struct diff_filespec *two,
3374                         struct strbuf *msg,
3375                         struct diff_options *o,
3376                         struct diff_filepair *p)
3377{
3378        const char *xfrm_msg = NULL;
3379        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3380        int must_show_header = 0;
3381
3382
3383        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3384                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3385                if (drv && drv->external)
3386                        pgm = drv->external;
3387        }
3388
3389        if (msg) {
3390                /*
3391                 * don't use colors when the header is intended for an
3392                 * external diff driver
3393                 */
3394                fill_metainfo(msg, name, other, one, two, o, p,
3395                              &must_show_header,
3396                              want_color(o->use_color) && !pgm);
3397                xfrm_msg = msg->len ? msg->buf : NULL;
3398        }
3399
3400        if (pgm) {
3401                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3402                                  complete_rewrite, o);
3403                return;
3404        }
3405        if (one && two)
3406                builtin_diff(name, other ? other : name,
3407                             one, two, xfrm_msg, must_show_header,
3408                             o, complete_rewrite);
3409        else
3410                fprintf(o->file, "* Unmerged path %s\n", name);
3411}
3412
3413static void diff_fill_oid_info(struct diff_filespec *one)
3414{
3415        if (DIFF_FILE_VALID(one)) {
3416                if (!one->oid_valid) {
3417                        struct stat st;
3418                        if (one->is_stdin) {
3419                                oidclr(&one->oid);
3420                                return;
3421                        }
3422                        if (lstat(one->path, &st) < 0)
3423                                die_errno("stat '%s'", one->path);
3424                        if (index_path(one->oid.hash, one->path, &st, 0))
3425                                die("cannot hash %s", one->path);
3426                }
3427        }
3428        else
3429                oidclr(&one->oid);
3430}
3431
3432static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3433{
3434        /* Strip the prefix but do not molest /dev/null and absolute paths */
3435        if (*namep && **namep != '/') {
3436                *namep += prefix_length;
3437                if (**namep == '/')
3438                        ++*namep;
3439        }
3440        if (*otherp && **otherp != '/') {
3441                *otherp += prefix_length;
3442                if (**otherp == '/')
3443                        ++*otherp;
3444        }
3445}
3446
3447static void run_diff(struct diff_filepair *p, struct diff_options *o)
3448{
3449        const char *pgm = external_diff();
3450        struct strbuf msg;
3451        struct diff_filespec *one = p->one;
3452        struct diff_filespec *two = p->two;
3453        const char *name;
3454        const char *other;
3455        const char *attr_path;
3456
3457        name  = one->path;
3458        other = (strcmp(name, two->path) ? two->path : NULL);
3459        attr_path = name;
3460        if (o->prefix_length)
3461                strip_prefix(o->prefix_length, &name, &other);
3462
3463        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3464                pgm = NULL;
3465
3466        if (DIFF_PAIR_UNMERGED(p)) {
3467                run_diff_cmd(pgm, name, NULL, attr_path,
3468                             NULL, NULL, NULL, o, p);
3469                return;
3470        }
3471
3472        diff_fill_oid_info(one);
3473        diff_fill_oid_info(two);
3474
3475        if (!pgm &&
3476            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3477            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3478                /*
3479                 * a filepair that changes between file and symlink
3480                 * needs to be split into deletion and creation.
3481                 */
3482                struct diff_filespec *null = alloc_filespec(two->path);
3483                run_diff_cmd(NULL, name, other, attr_path,
3484                             one, null, &msg, o, p);
3485                free(null);
3486                strbuf_release(&msg);
3487
3488                null = alloc_filespec(one->path);
3489                run_diff_cmd(NULL, name, other, attr_path,
3490                             null, two, &msg, o, p);
3491                free(null);
3492        }
3493        else
3494                run_diff_cmd(pgm, name, other, attr_path,
3495                             one, two, &msg, o, p);
3496
3497        strbuf_release(&msg);
3498}
3499
3500static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3501                         struct diffstat_t *diffstat)
3502{
3503        const char *name;
3504        const char *other;
3505
3506        if (DIFF_PAIR_UNMERGED(p)) {
3507                /* unmerged */
3508                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
3509                return;
3510        }
3511
3512        name = p->one->path;
3513        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3514
3515        if (o->prefix_length)
3516                strip_prefix(o->prefix_length, &name, &other);
3517
3518        diff_fill_oid_info(p->one);
3519        diff_fill_oid_info(p->two);
3520
3521        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
3522}
3523
3524static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3525{
3526        const char *name;
3527        const char *other;
3528        const char *attr_path;
3529
3530        if (DIFF_PAIR_UNMERGED(p)) {
3531                /* unmerged */
3532                return;
3533        }
3534
3535        name = p->one->path;
3536        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3537        attr_path = other ? other : name;
3538
3539        if (o->prefix_length)
3540                strip_prefix(o->prefix_length, &name, &other);
3541
3542        diff_fill_oid_info(p->one);
3543        diff_fill_oid_info(p->two);
3544
3545        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3546}
3547
3548void diff_setup(struct diff_options *options)
3549{
3550        memcpy(options, &default_diff_options, sizeof(*options));
3551
3552        options->file = stdout;
3553
3554        options->abbrev = DEFAULT_ABBREV;
3555        options->line_termination = '\n';
3556        options->break_opt = -1;
3557        options->rename_limit = -1;
3558        options->dirstat_permille = diff_dirstat_permille_default;
3559        options->context = diff_context_default;
3560        options->interhunkcontext = diff_interhunk_context_default;
3561        options->ws_error_highlight = ws_error_highlight_default;
3562        DIFF_OPT_SET(options, RENAME_EMPTY);
3563
3564        /* pathchange left =NULL by default */
3565        options->change = diff_change;
3566        options->add_remove = diff_addremove;
3567        options->use_color = diff_use_color_default;
3568        options->detect_rename = diff_detect_rename_default;
3569        options->xdl_opts |= diff_algorithm;
3570        if (diff_indent_heuristic)
3571                DIFF_XDL_SET(options, INDENT_HEURISTIC);
3572
3573        options->orderfile = diff_order_file_cfg;
3574
3575        if (diff_no_prefix) {
3576                options->a_prefix = options->b_prefix = "";
3577        } else if (!diff_mnemonic_prefix) {
3578                options->a_prefix = "a/";
3579                options->b_prefix = "b/";
3580        }
3581}
3582
3583void diff_setup_done(struct diff_options *options)
3584{
3585        int count = 0;
3586
3587        if (options->set_default)
3588                options->set_default(options);
3589
3590        if (options->output_format & DIFF_FORMAT_NAME)
3591                count++;
3592        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3593                count++;
3594        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3595                count++;
3596        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3597                count++;
3598        if (count > 1)
3599                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
3600
3601        /*
3602         * Most of the time we can say "there are changes"
3603         * only by checking if there are changed paths, but
3604         * --ignore-whitespace* options force us to look
3605         * inside contents.
3606         */
3607
3608        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3609            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3610            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3611                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3612        else
3613                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3614
3615        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3616                options->detect_rename = DIFF_DETECT_COPY;
3617
3618        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3619                options->prefix = NULL;
3620        if (options->prefix)
3621                options->prefix_length = strlen(options->prefix);
3622        else
3623                options->prefix_length = 0;
3624
3625        if (options->output_format & (DIFF_FORMAT_NAME |
3626                                      DIFF_FORMAT_NAME_STATUS |
3627                                      DIFF_FORMAT_CHECKDIFF |
3628                                      DIFF_FORMAT_NO_OUTPUT))
3629                options->output_format &= ~(DIFF_FORMAT_RAW |
3630                                            DIFF_FORMAT_NUMSTAT |
3631                                            DIFF_FORMAT_DIFFSTAT |
3632                                            DIFF_FORMAT_SHORTSTAT |
3633                                            DIFF_FORMAT_DIRSTAT |
3634                                            DIFF_FORMAT_SUMMARY |
3635                                            DIFF_FORMAT_PATCH);
3636
3637        /*
3638         * These cases always need recursive; we do not drop caller-supplied
3639         * recursive bits for other formats here.
3640         */
3641        if (options->output_format & (DIFF_FORMAT_PATCH |
3642                                      DIFF_FORMAT_NUMSTAT |
3643                                      DIFF_FORMAT_DIFFSTAT |
3644                                      DIFF_FORMAT_SHORTSTAT |
3645                                      DIFF_FORMAT_DIRSTAT |
3646                                      DIFF_FORMAT_SUMMARY |
3647                                      DIFF_FORMAT_CHECKDIFF))
3648                DIFF_OPT_SET(options, RECURSIVE);
3649        /*
3650         * Also pickaxe would not work very well if you do not say recursive
3651         */
3652        if (options->pickaxe)
3653                DIFF_OPT_SET(options, RECURSIVE);
3654        /*
3655         * When patches are generated, submodules diffed against the work tree
3656         * must be checked for dirtiness too so it can be shown in the output
3657         */
3658        if (options->output_format & DIFF_FORMAT_PATCH)
3659                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3660
3661        if (options->detect_rename && options->rename_limit < 0)
3662                options->rename_limit = diff_rename_limit_default;
3663        if (options->setup & DIFF_SETUP_USE_CACHE) {
3664                if (!active_cache)
3665                        /* read-cache does not die even when it fails
3666                         * so it is safe for us to do this here.  Also
3667                         * it does not smudge active_cache or active_nr
3668                         * when it fails, so we do not have to worry about
3669                         * cleaning it up ourselves either.
3670                         */
3671                        read_cache();
3672        }
3673        if (40 < options->abbrev)
3674                options->abbrev = 40; /* full */
3675
3676        /*
3677         * It does not make sense to show the first hit we happened
3678         * to have found.  It does not make sense not to return with
3679         * exit code in such a case either.
3680         */
3681        if (DIFF_OPT_TST(options, QUICK)) {
3682                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3683                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3684        }
3685
3686        options->diff_path_counter = 0;
3687
3688        if (DIFF_OPT_TST(options, FOLLOW_RENAMES) && options->pathspec.nr != 1)
3689                die(_("--follow requires exactly one pathspec"));
3690}
3691
3692static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3693{
3694        char c, *eq;
3695        int len;
3696
3697        if (*arg != '-')
3698                return 0;
3699        c = *++arg;
3700        if (!c)
3701                return 0;
3702        if (c == arg_short) {
3703                c = *++arg;
3704                if (!c)
3705                        return 1;
3706                if (val && isdigit(c)) {
3707                        char *end;
3708                        int n = strtoul(arg, &end, 10);
3709                        if (*end)
3710                                return 0;
3711                        *val = n;
3712                        return 1;
3713                }
3714                return 0;
3715        }
3716        if (c != '-')
3717                return 0;
3718        arg++;
3719        eq = strchrnul(arg, '=');
3720        len = eq - arg;
3721        if (!len || strncmp(arg, arg_long, len))
3722                return 0;
3723        if (*eq) {
3724                int n;
3725                char *end;
3726                if (!isdigit(*++eq))
3727                        return 0;
3728                n = strtoul(eq, &end, 10);
3729                if (*end)
3730                        return 0;
3731                *val = n;
3732        }
3733        return 1;
3734}
3735
3736static int diff_scoreopt_parse(const char *opt);
3737
3738static inline int short_opt(char opt, const char **argv,
3739                            const char **optarg)
3740{
3741        const char *arg = argv[0];
3742        if (arg[0] != '-' || arg[1] != opt)
3743                return 0;
3744        if (arg[2] != '\0') {
3745                *optarg = arg + 2;
3746                return 1;
3747        }
3748        if (!argv[1])
3749                die("Option '%c' requires a value", opt);
3750        *optarg = argv[1];
3751        return 2;
3752}
3753
3754int parse_long_opt(const char *opt, const char **argv,
3755                   const char **optarg)
3756{
3757        const char *arg = argv[0];
3758        if (!skip_prefix(arg, "--", &arg))
3759                return 0;
3760        if (!skip_prefix(arg, opt, &arg))
3761                return 0;
3762        if (*arg == '=') { /* stuck form: --option=value */
3763                *optarg = arg + 1;
3764                return 1;
3765        }
3766        if (*arg != '\0')
3767                return 0;
3768        /* separate form: --option value */
3769        if (!argv[1])
3770                die("Option '--%s' requires a value", opt);
3771        *optarg = argv[1];
3772        return 2;
3773}
3774
3775static int stat_opt(struct diff_options *options, const char **av)
3776{
3777        const char *arg = av[0];
3778        char *end;
3779        int width = options->stat_width;
3780        int name_width = options->stat_name_width;
3781        int graph_width = options->stat_graph_width;
3782        int count = options->stat_count;
3783        int argcount = 1;
3784
3785        if (!skip_prefix(arg, "--stat", &arg))
3786                die("BUG: stat option does not begin with --stat: %s", arg);
3787        end = (char *)arg;
3788
3789        switch (*arg) {
3790        case '-':
3791                if (skip_prefix(arg, "-width", &arg)) {
3792                        if (*arg == '=')
3793                                width = strtoul(arg + 1, &end, 10);
3794                        else if (!*arg && !av[1])
3795                                die_want_option("--stat-width");
3796                        else if (!*arg) {
3797                                width = strtoul(av[1], &end, 10);
3798                                argcount = 2;
3799                        }
3800                } else if (skip_prefix(arg, "-name-width", &arg)) {
3801                        if (*arg == '=')
3802                                name_width = strtoul(arg + 1, &end, 10);
3803                        else if (!*arg && !av[1])
3804                                die_want_option("--stat-name-width");
3805                        else if (!*arg) {
3806                                name_width = strtoul(av[1], &end, 10);
3807                                argcount = 2;
3808                        }
3809                } else if (skip_prefix(arg, "-graph-width", &arg)) {
3810                        if (*arg == '=')
3811                                graph_width = strtoul(arg + 1, &end, 10);
3812                        else if (!*arg && !av[1])
3813                                die_want_option("--stat-graph-width");
3814                        else if (!*arg) {
3815                                graph_width = strtoul(av[1], &end, 10);
3816                                argcount = 2;
3817                        }
3818                } else if (skip_prefix(arg, "-count", &arg)) {
3819                        if (*arg == '=')
3820                                count = strtoul(arg + 1, &end, 10);
3821                        else if (!*arg && !av[1])
3822                                die_want_option("--stat-count");
3823                        else if (!*arg) {
3824                                count = strtoul(av[1], &end, 10);
3825                                argcount = 2;
3826                        }
3827                }
3828                break;
3829        case '=':
3830                width = strtoul(arg+1, &end, 10);
3831                if (*end == ',')
3832                        name_width = strtoul(end+1, &end, 10);
3833                if (*end == ',')
3834                        count = strtoul(end+1, &end, 10);
3835        }
3836
3837        /* Important! This checks all the error cases! */
3838        if (*end)
3839                return 0;
3840        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3841        options->stat_name_width = name_width;
3842        options->stat_graph_width = graph_width;
3843        options->stat_width = width;
3844        options->stat_count = count;
3845        return argcount;
3846}
3847
3848static int parse_dirstat_opt(struct diff_options *options, const char *params)
3849{
3850        struct strbuf errmsg = STRBUF_INIT;
3851        if (parse_dirstat_params(options, params, &errmsg))
3852                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3853                    errmsg.buf);
3854        strbuf_release(&errmsg);
3855        /*
3856         * The caller knows a dirstat-related option is given from the command
3857         * line; allow it to say "return this_function();"
3858         */
3859        options->output_format |= DIFF_FORMAT_DIRSTAT;
3860        return 1;
3861}
3862
3863static int parse_submodule_opt(struct diff_options *options, const char *value)
3864{
3865        if (parse_submodule_params(options, value))
3866                die(_("Failed to parse --submodule option parameter: '%s'"),
3867                        value);
3868        return 1;
3869}
3870
3871static const char diff_status_letters[] = {
3872        DIFF_STATUS_ADDED,
3873        DIFF_STATUS_COPIED,
3874        DIFF_STATUS_DELETED,
3875        DIFF_STATUS_MODIFIED,
3876        DIFF_STATUS_RENAMED,
3877        DIFF_STATUS_TYPE_CHANGED,
3878        DIFF_STATUS_UNKNOWN,
3879        DIFF_STATUS_UNMERGED,
3880        DIFF_STATUS_FILTER_AON,
3881        DIFF_STATUS_FILTER_BROKEN,
3882        '\0',
3883};
3884
3885static unsigned int filter_bit['Z' + 1];
3886
3887static void prepare_filter_bits(void)
3888{
3889        int i;
3890
3891        if (!filter_bit[DIFF_STATUS_ADDED]) {
3892                for (i = 0; diff_status_letters[i]; i++)
3893                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
3894        }
3895}
3896
3897static unsigned filter_bit_tst(char status, const struct diff_options *opt)
3898{
3899        return opt->filter & filter_bit[(int) status];
3900}
3901
3902static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
3903{
3904        int i, optch;
3905
3906        prepare_filter_bits();
3907
3908        /*
3909         * If there is a negation e.g. 'd' in the input, and we haven't
3910         * initialized the filter field with another --diff-filter, start
3911         * from full set of bits, except for AON.
3912         */
3913        if (!opt->filter) {
3914                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3915                        if (optch < 'a' || 'z' < optch)
3916                                continue;
3917                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
3918                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
3919                        break;
3920                }
3921        }
3922
3923        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3924                unsigned int bit;
3925                int negate;
3926
3927                if ('a' <= optch && optch <= 'z') {
3928                        negate = 1;
3929                        optch = toupper(optch);
3930                } else {
3931                        negate = 0;
3932                }
3933
3934                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
3935                if (!bit)
3936                        return optarg[i];
3937                if (negate)
3938                        opt->filter &= ~bit;
3939                else
3940                        opt->filter |= bit;
3941        }
3942        return 0;
3943}
3944
3945static void enable_patch_output(int *fmt) {
3946        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
3947        *fmt |= DIFF_FORMAT_PATCH;
3948}
3949
3950static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
3951{
3952        int val = parse_ws_error_highlight(arg);
3953
3954        if (val < 0) {
3955                error("unknown value after ws-error-highlight=%.*s",
3956                      -1 - val, arg);
3957                return 0;
3958        }
3959        opt->ws_error_highlight = val;
3960        return 1;
3961}
3962
3963int diff_opt_parse(struct diff_options *options,
3964                   const char **av, int ac, const char *prefix)
3965{
3966        const char *arg = av[0];
3967        const char *optarg;
3968        int argcount;
3969
3970        if (!prefix)
3971                prefix = "";
3972
3973        /* Output format options */
3974        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
3975            || opt_arg(arg, 'U', "unified", &options->context))
3976                enable_patch_output(&options->output_format);
3977        else if (!strcmp(arg, "--raw"))
3978                options->output_format |= DIFF_FORMAT_RAW;
3979        else if (!strcmp(arg, "--patch-with-raw")) {
3980                enable_patch_output(&options->output_format);
3981                options->output_format |= DIFF_FORMAT_RAW;
3982        } else if (!strcmp(arg, "--numstat"))
3983                options->output_format |= DIFF_FORMAT_NUMSTAT;
3984        else if (!strcmp(arg, "--shortstat"))
3985                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3986        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3987                return parse_dirstat_opt(options, "");
3988        else if (skip_prefix(arg, "-X", &arg))
3989                return parse_dirstat_opt(options, arg);
3990        else if (skip_prefix(arg, "--dirstat=", &arg))
3991                return parse_dirstat_opt(options, arg);
3992        else if (!strcmp(arg, "--cumulative"))
3993                return parse_dirstat_opt(options, "cumulative");
3994        else if (!strcmp(arg, "--dirstat-by-file"))
3995                return parse_dirstat_opt(options, "files");
3996        else if (skip_prefix(arg, "--dirstat-by-file=", &arg)) {
3997                parse_dirstat_opt(options, "files");
3998                return parse_dirstat_opt(options, arg);
3999        }
4000        else if (!strcmp(arg, "--check"))
4001                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4002        else if (!strcmp(arg, "--summary"))
4003                options->output_format |= DIFF_FORMAT_SUMMARY;
4004        else if (!strcmp(arg, "--patch-with-stat")) {
4005                enable_patch_output(&options->output_format);
4006                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4007        } else if (!strcmp(arg, "--name-only"))
4008                options->output_format |= DIFF_FORMAT_NAME;
4009        else if (!strcmp(arg, "--name-status"))
4010                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4011        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4012                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4013        else if (starts_with(arg, "--stat"))
4014                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4015                return stat_opt(options, av);
4016
4017        /* renames options */
4018        else if (starts_with(arg, "-B") || starts_with(arg, "--break-rewrites=") ||
4019                 !strcmp(arg, "--break-rewrites")) {
4020                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4021                        return error("invalid argument to -B: %s", arg+2);
4022        }
4023        else if (starts_with(arg, "-M") || starts_with(arg, "--find-renames=") ||
4024                 !strcmp(arg, "--find-renames")) {
4025                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4026                        return error("invalid argument to -M: %s", arg+2);
4027                options->detect_rename = DIFF_DETECT_RENAME;
4028        }
4029        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4030                options->irreversible_delete = 1;
4031        }
4032        else if (starts_with(arg, "-C") || starts_with(arg, "--find-copies=") ||
4033                 !strcmp(arg, "--find-copies")) {
4034                if (options->detect_rename == DIFF_DETECT_COPY)
4035                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
4036                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4037                        return error("invalid argument to -C: %s", arg+2);
4038                options->detect_rename = DIFF_DETECT_COPY;
4039        }
4040        else if (!strcmp(arg, "--no-renames"))
4041                options->detect_rename = 0;
4042        else if (!strcmp(arg, "--rename-empty"))
4043                DIFF_OPT_SET(options, RENAME_EMPTY);
4044        else if (!strcmp(arg, "--no-rename-empty"))
4045                DIFF_OPT_CLR(options, RENAME_EMPTY);
4046        else if (!strcmp(arg, "--relative"))
4047                DIFF_OPT_SET(options, RELATIVE_NAME);
4048        else if (skip_prefix(arg, "--relative=", &arg)) {
4049                DIFF_OPT_SET(options, RELATIVE_NAME);
4050                options->prefix = arg;
4051        }
4052
4053        /* xdiff options */
4054        else if (!strcmp(arg, "--minimal"))
4055                DIFF_XDL_SET(options, NEED_MINIMAL);
4056        else if (!strcmp(arg, "--no-minimal"))
4057                DIFF_XDL_CLR(options, NEED_MINIMAL);
4058        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4059                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4060        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4061                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4062        else if (!strcmp(arg, "--ignore-space-at-eol"))
4063                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4064        else if (!strcmp(arg, "--ignore-blank-lines"))
4065                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4066        else if (!strcmp(arg, "--indent-heuristic"))
4067                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4068        else if (!strcmp(arg, "--no-indent-heuristic"))
4069                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4070        else if (!strcmp(arg, "--patience"))
4071                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4072        else if (!strcmp(arg, "--histogram"))
4073                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4074        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4075                long value = parse_algorithm_value(optarg);
4076                if (value < 0)
4077                        return error("option diff-algorithm accepts \"myers\", "
4078                                     "\"minimal\", \"patience\" and \"histogram\"");
4079                /* clear out previous settings */
4080                DIFF_XDL_CLR(options, NEED_MINIMAL);
4081                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4082                options->xdl_opts |= value;
4083                return argcount;
4084        }
4085
4086        /* flags options */
4087        else if (!strcmp(arg, "--binary")) {
4088                enable_patch_output(&options->output_format);
4089                DIFF_OPT_SET(options, BINARY);
4090        }
4091        else if (!strcmp(arg, "--full-index"))
4092                DIFF_OPT_SET(options, FULL_INDEX);
4093        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4094                DIFF_OPT_SET(options, TEXT);
4095        else if (!strcmp(arg, "-R"))
4096                DIFF_OPT_SET(options, REVERSE_DIFF);
4097        else if (!strcmp(arg, "--find-copies-harder"))
4098                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
4099        else if (!strcmp(arg, "--follow"))
4100                DIFF_OPT_SET(options, FOLLOW_RENAMES);
4101        else if (!strcmp(arg, "--no-follow")) {
4102                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
4103                DIFF_OPT_CLR(options, DEFAULT_FOLLOW_RENAMES);
4104        } else if (!strcmp(arg, "--color"))
4105                options->use_color = 1;
4106        else if (skip_prefix(arg, "--color=", &arg)) {
4107                int value = git_config_colorbool(NULL, arg);
4108                if (value < 0)
4109                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4110                options->use_color = value;
4111        }
4112        else if (!strcmp(arg, "--no-color"))
4113                options->use_color = 0;
4114        else if (!strcmp(arg, "--color-words")) {
4115                options->use_color = 1;
4116                options->word_diff = DIFF_WORDS_COLOR;
4117        }
4118        else if (skip_prefix(arg, "--color-words=", &arg)) {
4119                options->use_color = 1;
4120                options->word_diff = DIFF_WORDS_COLOR;
4121                options->word_regex = arg;
4122        }
4123        else if (!strcmp(arg, "--word-diff")) {
4124                if (options->word_diff == DIFF_WORDS_NONE)
4125                        options->word_diff = DIFF_WORDS_PLAIN;
4126        }
4127        else if (skip_prefix(arg, "--word-diff=", &arg)) {
4128                if (!strcmp(arg, "plain"))
4129                        options->word_diff = DIFF_WORDS_PLAIN;
4130                else if (!strcmp(arg, "color")) {
4131                        options->use_color = 1;
4132                        options->word_diff = DIFF_WORDS_COLOR;
4133                }
4134                else if (!strcmp(arg, "porcelain"))
4135                        options->word_diff = DIFF_WORDS_PORCELAIN;
4136                else if (!strcmp(arg, "none"))
4137                        options->word_diff = DIFF_WORDS_NONE;
4138                else
4139                        die("bad --word-diff argument: %s", arg);
4140        }
4141        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
4142                if (options->word_diff == DIFF_WORDS_NONE)
4143                        options->word_diff = DIFF_WORDS_PLAIN;
4144                options->word_regex = optarg;
4145                return argcount;
4146        }
4147        else if (!strcmp(arg, "--exit-code"))
4148                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
4149        else if (!strcmp(arg, "--quiet"))
4150                DIFF_OPT_SET(options, QUICK);
4151        else if (!strcmp(arg, "--ext-diff"))
4152                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
4153        else if (!strcmp(arg, "--no-ext-diff"))
4154                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
4155        else if (!strcmp(arg, "--textconv"))
4156                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
4157        else if (!strcmp(arg, "--no-textconv"))
4158                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
4159        else if (!strcmp(arg, "--ignore-submodules")) {
4160                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
4161                handle_ignore_submodules_arg(options, "all");
4162        } else if (skip_prefix(arg, "--ignore-submodules=", &arg)) {
4163                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
4164                handle_ignore_submodules_arg(options, arg);
4165        } else if (!strcmp(arg, "--submodule"))
4166                options->submodule_format = DIFF_SUBMODULE_LOG;
4167        else if (skip_prefix(arg, "--submodule=", &arg))
4168                return parse_submodule_opt(options, arg);
4169        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
4170                return parse_ws_error_highlight_opt(options, arg);
4171        else if (!strcmp(arg, "--ita-invisible-in-index"))
4172                options->ita_invisible_in_index = 1;
4173        else if (!strcmp(arg, "--ita-visible-in-index"))
4174                options->ita_invisible_in_index = 0;
4175
4176        /* misc options */
4177        else if (!strcmp(arg, "-z"))
4178                options->line_termination = 0;
4179        else if ((argcount = short_opt('l', av, &optarg))) {
4180                options->rename_limit = strtoul(optarg, NULL, 10);
4181                return argcount;
4182        }
4183        else if ((argcount = short_opt('S', av, &optarg))) {
4184                options->pickaxe = optarg;
4185                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
4186                return argcount;
4187        } else if ((argcount = short_opt('G', av, &optarg))) {
4188                options->pickaxe = optarg;
4189                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
4190                return argcount;
4191        }
4192        else if (!strcmp(arg, "--pickaxe-all"))
4193                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
4194        else if (!strcmp(arg, "--pickaxe-regex"))
4195                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
4196        else if ((argcount = short_opt('O', av, &optarg))) {
4197                options->orderfile = prefix_filename(prefix, optarg);
4198                return argcount;
4199        }
4200        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
4201                int offending = parse_diff_filter_opt(optarg, options);
4202                if (offending)
4203                        die("unknown change class '%c' in --diff-filter=%s",
4204                            offending, optarg);
4205                return argcount;
4206        }
4207        else if (!strcmp(arg, "--no-abbrev"))
4208                options->abbrev = 0;
4209        else if (!strcmp(arg, "--abbrev"))
4210                options->abbrev = DEFAULT_ABBREV;
4211        else if (skip_prefix(arg, "--abbrev=", &arg)) {
4212                options->abbrev = strtoul(arg, NULL, 10);
4213                if (options->abbrev < MINIMUM_ABBREV)
4214                        options->abbrev = MINIMUM_ABBREV;
4215                else if (40 < options->abbrev)
4216                        options->abbrev = 40;
4217        }
4218        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
4219                options->a_prefix = optarg;
4220                return argcount;
4221        }
4222        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
4223                options->line_prefix = optarg;
4224                options->line_prefix_length = strlen(options->line_prefix);
4225                graph_setup_line_prefix(options);
4226                return argcount;
4227        }
4228        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
4229                options->b_prefix = optarg;
4230                return argcount;
4231        }
4232        else if (!strcmp(arg, "--no-prefix"))
4233                options->a_prefix = options->b_prefix = "";
4234        else if (opt_arg(arg, '\0', "inter-hunk-context",
4235                         &options->interhunkcontext))
4236                ;
4237        else if (!strcmp(arg, "-W"))
4238                DIFF_OPT_SET(options, FUNCCONTEXT);
4239        else if (!strcmp(arg, "--function-context"))
4240                DIFF_OPT_SET(options, FUNCCONTEXT);
4241        else if (!strcmp(arg, "--no-function-context"))
4242                DIFF_OPT_CLR(options, FUNCCONTEXT);
4243        else if ((argcount = parse_long_opt("output", av, &optarg))) {
4244                char *path = prefix_filename(prefix, optarg);
4245                options->file = xfopen(path, "w");
4246                options->close_file = 1;
4247                if (options->use_color != GIT_COLOR_ALWAYS)
4248                        options->use_color = GIT_COLOR_NEVER;
4249                free(path);
4250                return argcount;
4251        } else
4252                return 0;
4253        return 1;
4254}
4255
4256int parse_rename_score(const char **cp_p)
4257{
4258        unsigned long num, scale;
4259        int ch, dot;
4260        const char *cp = *cp_p;
4261
4262        num = 0;
4263        scale = 1;
4264        dot = 0;
4265        for (;;) {
4266                ch = *cp;
4267                if ( !dot && ch == '.' ) {
4268                        scale = 1;
4269                        dot = 1;
4270                } else if ( ch == '%' ) {
4271                        scale = dot ? scale*100 : 100;
4272                        cp++;   /* % is always at the end */
4273                        break;
4274                } else if ( ch >= '0' && ch <= '9' ) {
4275                        if ( scale < 100000 ) {
4276                                scale *= 10;
4277                                num = (num*10) + (ch-'0');
4278                        }
4279                } else {
4280                        break;
4281                }
4282                cp++;
4283        }
4284        *cp_p = cp;
4285
4286        /* user says num divided by scale and we say internally that
4287         * is MAX_SCORE * num / scale.
4288         */
4289        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
4290}
4291
4292static int diff_scoreopt_parse(const char *opt)
4293{
4294        int opt1, opt2, cmd;
4295
4296        if (*opt++ != '-')
4297                return -1;
4298        cmd = *opt++;
4299        if (cmd == '-') {
4300                /* convert the long-form arguments into short-form versions */
4301                if (skip_prefix(opt, "break-rewrites", &opt)) {
4302                        if (*opt == 0 || *opt++ == '=')
4303                                cmd = 'B';
4304                } else if (skip_prefix(opt, "find-copies", &opt)) {
4305                        if (*opt == 0 || *opt++ == '=')
4306                                cmd = 'C';
4307                } else if (skip_prefix(opt, "find-renames", &opt)) {
4308                        if (*opt == 0 || *opt++ == '=')
4309                                cmd = 'M';
4310                }
4311        }
4312        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
4313                return -1; /* that is not a -M, -C, or -B option */
4314
4315        opt1 = parse_rename_score(&opt);
4316        if (cmd != 'B')
4317                opt2 = 0;
4318        else {
4319                if (*opt == 0)
4320                        opt2 = 0;
4321                else if (*opt != '/')
4322                        return -1; /* we expect -B80/99 or -B80 */
4323                else {
4324                        opt++;
4325                        opt2 = parse_rename_score(&opt);
4326                }
4327        }
4328        if (*opt != 0)
4329                return -1;
4330        return opt1 | (opt2 << 16);
4331}
4332
4333struct diff_queue_struct diff_queued_diff;
4334
4335void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
4336{
4337        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
4338        queue->queue[queue->nr++] = dp;
4339}
4340
4341struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
4342                                 struct diff_filespec *one,
4343                                 struct diff_filespec *two)
4344{
4345        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
4346        dp->one = one;
4347        dp->two = two;
4348        if (queue)
4349                diff_q(queue, dp);
4350        return dp;
4351}
4352
4353void diff_free_filepair(struct diff_filepair *p)
4354{
4355        free_filespec(p->one);
4356        free_filespec(p->two);
4357        free(p);
4358}
4359
4360const char *diff_aligned_abbrev(const struct object_id *oid, int len)
4361{
4362        int abblen;
4363        const char *abbrev;
4364
4365        if (len == GIT_SHA1_HEXSZ)
4366                return oid_to_hex(oid);
4367
4368        abbrev = diff_abbrev_oid(oid, len);
4369        abblen = strlen(abbrev);
4370
4371        /*
4372         * In well-behaved cases, where the abbbreviated result is the
4373         * same as the requested length, append three dots after the
4374         * abbreviation (hence the whole logic is limited to the case
4375         * where abblen < 37); when the actual abbreviated result is a
4376         * bit longer than the requested length, we reduce the number
4377         * of dots so that they match the well-behaved ones.  However,
4378         * if the actual abbreviation is longer than the requested
4379         * length by more than three, we give up on aligning, and add
4380         * three dots anyway, to indicate that the output is not the
4381         * full object name.  Yes, this may be suboptimal, but this
4382         * appears only in "diff --raw --abbrev" output and it is not
4383         * worth the effort to change it now.  Note that this would
4384         * likely to work fine when the automatic sizing of default
4385         * abbreviation length is used--we would be fed -1 in "len" in
4386         * that case, and will end up always appending three-dots, but
4387         * the automatic sizing is supposed to give abblen that ensures
4388         * uniqueness across all objects (statistically speaking).
4389         */
4390        if (abblen < GIT_SHA1_HEXSZ - 3) {
4391                static char hex[GIT_MAX_HEXSZ + 1];
4392                if (len < abblen && abblen <= len + 2)
4393                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
4394                else
4395                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
4396                return hex;
4397        }
4398
4399        return oid_to_hex(oid);
4400}
4401
4402static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4403{
4404        int line_termination = opt->line_termination;
4405        int inter_name_termination = line_termination ? '\t' : '\0';
4406
4407        fprintf(opt->file, "%s", diff_line_prefix(opt));
4408        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
4409                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
4410                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
4411                fprintf(opt->file, "%s ",
4412                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
4413        }
4414        if (p->score) {
4415                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
4416                        inter_name_termination);
4417        } else {
4418                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
4419        }
4420
4421        if (p->status == DIFF_STATUS_COPIED ||
4422            p->status == DIFF_STATUS_RENAMED) {
4423                const char *name_a, *name_b;
4424                name_a = p->one->path;
4425                name_b = p->two->path;
4426                strip_prefix(opt->prefix_length, &name_a, &name_b);
4427                write_name_quoted(name_a, opt->file, inter_name_termination);
4428                write_name_quoted(name_b, opt->file, line_termination);
4429        } else {
4430                const char *name_a, *name_b;
4431                name_a = p->one->mode ? p->one->path : p->two->path;
4432                name_b = NULL;
4433                strip_prefix(opt->prefix_length, &name_a, &name_b);
4434                write_name_quoted(name_a, opt->file, line_termination);
4435        }
4436}
4437
4438int diff_unmodified_pair(struct diff_filepair *p)
4439{
4440        /* This function is written stricter than necessary to support
4441         * the currently implemented transformers, but the idea is to
4442         * let transformers to produce diff_filepairs any way they want,
4443         * and filter and clean them up here before producing the output.
4444         */
4445        struct diff_filespec *one = p->one, *two = p->two;
4446
4447        if (DIFF_PAIR_UNMERGED(p))
4448                return 0; /* unmerged is interesting */
4449
4450        /* deletion, addition, mode or type change
4451         * and rename are all interesting.
4452         */
4453        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
4454            DIFF_PAIR_MODE_CHANGED(p) ||
4455            strcmp(one->path, two->path))
4456                return 0;
4457
4458        /* both are valid and point at the same path.  that is, we are
4459         * dealing with a change.
4460         */
4461        if (one->oid_valid && two->oid_valid &&
4462            !oidcmp(&one->oid, &two->oid) &&
4463            !one->dirty_submodule && !two->dirty_submodule)
4464                return 1; /* no change */
4465        if (!one->oid_valid && !two->oid_valid)
4466                return 1; /* both look at the same file on the filesystem. */
4467        return 0;
4468}
4469
4470static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
4471{
4472        if (diff_unmodified_pair(p))
4473                return;
4474
4475        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4476            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4477                return; /* no tree diffs in patch format */
4478
4479        run_diff(p, o);
4480}
4481
4482static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
4483                            struct diffstat_t *diffstat)
4484{
4485        if (diff_unmodified_pair(p))
4486                return;
4487
4488        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4489            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4490                return; /* no useful stat for tree diffs */
4491
4492        run_diffstat(p, o, diffstat);
4493}
4494
4495static void diff_flush_checkdiff(struct diff_filepair *p,
4496                struct diff_options *o)
4497{
4498        if (diff_unmodified_pair(p))
4499                return;
4500
4501        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4502            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4503                return; /* nothing to check in tree diffs */
4504
4505        run_checkdiff(p, o);
4506}
4507
4508int diff_queue_is_empty(void)
4509{
4510        struct diff_queue_struct *q = &diff_queued_diff;
4511        int i;
4512        for (i = 0; i < q->nr; i++)
4513                if (!diff_unmodified_pair(q->queue[i]))
4514                        return 0;
4515        return 1;
4516}
4517
4518#if DIFF_DEBUG
4519void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
4520{
4521        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
4522                x, one ? one : "",
4523                s->path,
4524                DIFF_FILE_VALID(s) ? "valid" : "invalid",
4525                s->mode,
4526                s->oid_valid ? oid_to_hex(&s->oid) : "");
4527        fprintf(stderr, "queue[%d] %s size %lu\n",
4528                x, one ? one : "",
4529                s->size);
4530}
4531
4532void diff_debug_filepair(const struct diff_filepair *p, int i)
4533{
4534        diff_debug_filespec(p->one, i, "one");
4535        diff_debug_filespec(p->two, i, "two");
4536        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4537                p->score, p->status ? p->status : '?',
4538                p->one->rename_used, p->broken_pair);
4539}
4540
4541void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4542{
4543        int i;
4544        if (msg)
4545                fprintf(stderr, "%s\n", msg);
4546        fprintf(stderr, "q->nr = %d\n", q->nr);
4547        for (i = 0; i < q->nr; i++) {
4548                struct diff_filepair *p = q->queue[i];
4549                diff_debug_filepair(p, i);
4550        }
4551}
4552#endif
4553
4554static void diff_resolve_rename_copy(void)
4555{
4556        int i;
4557        struct diff_filepair *p;
4558        struct diff_queue_struct *q = &diff_queued_diff;
4559
4560        diff_debug_queue("resolve-rename-copy", q);
4561
4562        for (i = 0; i < q->nr; i++) {
4563                p = q->queue[i];
4564                p->status = 0; /* undecided */
4565                if (DIFF_PAIR_UNMERGED(p))
4566                        p->status = DIFF_STATUS_UNMERGED;
4567                else if (!DIFF_FILE_VALID(p->one))
4568                        p->status = DIFF_STATUS_ADDED;
4569                else if (!DIFF_FILE_VALID(p->two))
4570                        p->status = DIFF_STATUS_DELETED;
4571                else if (DIFF_PAIR_TYPE_CHANGED(p))
4572                        p->status = DIFF_STATUS_TYPE_CHANGED;
4573
4574                /* from this point on, we are dealing with a pair
4575                 * whose both sides are valid and of the same type, i.e.
4576                 * either in-place edit or rename/copy edit.
4577                 */
4578                else if (DIFF_PAIR_RENAME(p)) {
4579                        /*
4580                         * A rename might have re-connected a broken
4581                         * pair up, causing the pathnames to be the
4582                         * same again. If so, that's not a rename at
4583                         * all, just a modification..
4584                         *
4585                         * Otherwise, see if this source was used for
4586                         * multiple renames, in which case we decrement
4587                         * the count, and call it a copy.
4588                         */
4589                        if (!strcmp(p->one->path, p->two->path))
4590                                p->status = DIFF_STATUS_MODIFIED;
4591                        else if (--p->one->rename_used > 0)
4592                                p->status = DIFF_STATUS_COPIED;
4593                        else
4594                                p->status = DIFF_STATUS_RENAMED;
4595                }
4596                else if (oidcmp(&p->one->oid, &p->two->oid) ||
4597                         p->one->mode != p->two->mode ||
4598                         p->one->dirty_submodule ||
4599                         p->two->dirty_submodule ||
4600                         is_null_oid(&p->one->oid))
4601                        p->status = DIFF_STATUS_MODIFIED;
4602                else {
4603                        /* This is a "no-change" entry and should not
4604                         * happen anymore, but prepare for broken callers.
4605                         */
4606                        error("feeding unmodified %s to diffcore",
4607                              p->one->path);
4608                        p->status = DIFF_STATUS_UNKNOWN;
4609                }
4610        }
4611        diff_debug_queue("resolve-rename-copy done", q);
4612}
4613
4614static int check_pair_status(struct diff_filepair *p)
4615{
4616        switch (p->status) {
4617        case DIFF_STATUS_UNKNOWN:
4618                return 0;
4619        case 0:
4620                die("internal error in diff-resolve-rename-copy");
4621        default:
4622                return 1;
4623        }
4624}
4625
4626static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4627{
4628        int fmt = opt->output_format;
4629
4630        if (fmt & DIFF_FORMAT_CHECKDIFF)
4631                diff_flush_checkdiff(p, opt);
4632        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4633                diff_flush_raw(p, opt);
4634        else if (fmt & DIFF_FORMAT_NAME) {
4635                const char *name_a, *name_b;
4636                name_a = p->two->path;
4637                name_b = NULL;
4638                strip_prefix(opt->prefix_length, &name_a, &name_b);
4639                fprintf(opt->file, "%s", diff_line_prefix(opt));
4640                write_name_quoted(name_a, opt->file, opt->line_termination);
4641        }
4642}
4643
4644static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4645{
4646        if (fs->mode)
4647                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4648        else
4649                fprintf(file, " %s ", newdelete);
4650        write_name_quoted(fs->path, file, '\n');
4651}
4652
4653
4654static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4655                const char *line_prefix)
4656{
4657        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4658                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4659                        p->two->mode, show_name ? ' ' : '\n');
4660                if (show_name) {
4661                        write_name_quoted(p->two->path, file, '\n');
4662                }
4663        }
4664}
4665
4666static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4667                        const char *line_prefix)
4668{
4669        char *names = pprint_rename(p->one->path, p->two->path);
4670
4671        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4672        free(names);
4673        show_mode_change(file, p, 0, line_prefix);
4674}
4675
4676static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4677{
4678        FILE *file = opt->file;
4679        const char *line_prefix = diff_line_prefix(opt);
4680
4681        switch(p->status) {
4682        case DIFF_STATUS_DELETED:
4683                fputs(line_prefix, file);
4684                show_file_mode_name(file, "delete", p->one);
4685                break;
4686        case DIFF_STATUS_ADDED:
4687                fputs(line_prefix, file);
4688                show_file_mode_name(file, "create", p->two);
4689                break;
4690        case DIFF_STATUS_COPIED:
4691                fputs(line_prefix, file);
4692                show_rename_copy(file, "copy", p, line_prefix);
4693                break;
4694        case DIFF_STATUS_RENAMED:
4695                fputs(line_prefix, file);
4696                show_rename_copy(file, "rename", p, line_prefix);
4697                break;
4698        default:
4699                if (p->score) {
4700                        fprintf(file, "%s rewrite ", line_prefix);
4701                        write_name_quoted(p->two->path, file, ' ');
4702                        fprintf(file, "(%d%%)\n", similarity_index(p));
4703                }
4704                show_mode_change(file, p, !p->score, line_prefix);
4705                break;
4706        }
4707}
4708
4709struct patch_id_t {
4710        git_SHA_CTX *ctx;
4711        int patchlen;
4712};
4713
4714static int remove_space(char *line, int len)
4715{
4716        int i;
4717        char *dst = line;
4718        unsigned char c;
4719
4720        for (i = 0; i < len; i++)
4721                if (!isspace((c = line[i])))
4722                        *dst++ = c;
4723
4724        return dst - line;
4725}
4726
4727static void patch_id_consume(void *priv, char *line, unsigned long len)
4728{
4729        struct patch_id_t *data = priv;
4730        int new_len;
4731
4732        /* Ignore line numbers when computing the SHA1 of the patch */
4733        if (starts_with(line, "@@ -"))
4734                return;
4735
4736        new_len = remove_space(line, len);
4737
4738        git_SHA1_Update(data->ctx, line, new_len);
4739        data->patchlen += new_len;
4740}
4741
4742static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
4743{
4744        git_SHA1_Update(ctx, str, strlen(str));
4745}
4746
4747static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
4748{
4749        /* large enough for 2^32 in octal */
4750        char buf[12];
4751        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
4752        git_SHA1_Update(ctx, buf, len);
4753}
4754
4755/* returns 0 upon success, and writes result into sha1 */
4756static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
4757{
4758        struct diff_queue_struct *q = &diff_queued_diff;
4759        int i;
4760        git_SHA_CTX ctx;
4761        struct patch_id_t data;
4762
4763        git_SHA1_Init(&ctx);
4764        memset(&data, 0, sizeof(struct patch_id_t));
4765        data.ctx = &ctx;
4766
4767        for (i = 0; i < q->nr; i++) {
4768                xpparam_t xpp;
4769                xdemitconf_t xecfg;
4770                mmfile_t mf1, mf2;
4771                struct diff_filepair *p = q->queue[i];
4772                int len1, len2;
4773
4774                memset(&xpp, 0, sizeof(xpp));
4775                memset(&xecfg, 0, sizeof(xecfg));
4776                if (p->status == 0)
4777                        return error("internal diff status error");
4778                if (p->status == DIFF_STATUS_UNKNOWN)
4779                        continue;
4780                if (diff_unmodified_pair(p))
4781                        continue;
4782                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4783                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4784                        continue;
4785                if (DIFF_PAIR_UNMERGED(p))
4786                        continue;
4787
4788                diff_fill_oid_info(p->one);
4789                diff_fill_oid_info(p->two);
4790
4791                len1 = remove_space(p->one->path, strlen(p->one->path));
4792                len2 = remove_space(p->two->path, strlen(p->two->path));
4793                patch_id_add_string(&ctx, "diff--git");
4794                patch_id_add_string(&ctx, "a/");
4795                git_SHA1_Update(&ctx, p->one->path, len1);
4796                patch_id_add_string(&ctx, "b/");
4797                git_SHA1_Update(&ctx, p->two->path, len2);
4798
4799                if (p->one->mode == 0) {
4800                        patch_id_add_string(&ctx, "newfilemode");
4801                        patch_id_add_mode(&ctx, p->two->mode);
4802                        patch_id_add_string(&ctx, "---/dev/null");
4803                        patch_id_add_string(&ctx, "+++b/");
4804                        git_SHA1_Update(&ctx, p->two->path, len2);
4805                } else if (p->two->mode == 0) {
4806                        patch_id_add_string(&ctx, "deletedfilemode");
4807                        patch_id_add_mode(&ctx, p->one->mode);
4808                        patch_id_add_string(&ctx, "---a/");
4809                        git_SHA1_Update(&ctx, p->one->path, len1);
4810                        patch_id_add_string(&ctx, "+++/dev/null");
4811                } else {
4812                        patch_id_add_string(&ctx, "---a/");
4813                        git_SHA1_Update(&ctx, p->one->path, len1);
4814                        patch_id_add_string(&ctx, "+++b/");
4815                        git_SHA1_Update(&ctx, p->two->path, len2);
4816                }
4817
4818                if (diff_header_only)
4819                        continue;
4820
4821                if (fill_mmfile(&mf1, p->one) < 0 ||
4822                    fill_mmfile(&mf2, p->two) < 0)
4823                        return error("unable to read files to diff");
4824
4825                if (diff_filespec_is_binary(p->one) ||
4826                    diff_filespec_is_binary(p->two)) {
4827                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
4828                                        GIT_SHA1_HEXSZ);
4829                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
4830                                        GIT_SHA1_HEXSZ);
4831                        continue;
4832                }
4833
4834                xpp.flags = 0;
4835                xecfg.ctxlen = 3;
4836                xecfg.flags = 0;
4837                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4838                                  &xpp, &xecfg))
4839                        return error("unable to generate patch-id diff for %s",
4840                                     p->one->path);
4841        }
4842
4843        git_SHA1_Final(oid->hash, &ctx);
4844        return 0;
4845}
4846
4847int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
4848{
4849        struct diff_queue_struct *q = &diff_queued_diff;
4850        int i;
4851        int result = diff_get_patch_id(options, oid, diff_header_only);
4852
4853        for (i = 0; i < q->nr; i++)
4854                diff_free_filepair(q->queue[i]);
4855
4856        free(q->queue);
4857        DIFF_QUEUE_CLEAR(q);
4858
4859        return result;
4860}
4861
4862static int is_summary_empty(const struct diff_queue_struct *q)
4863{
4864        int i;
4865
4866        for (i = 0; i < q->nr; i++) {
4867                const struct diff_filepair *p = q->queue[i];
4868
4869                switch (p->status) {
4870                case DIFF_STATUS_DELETED:
4871                case DIFF_STATUS_ADDED:
4872                case DIFF_STATUS_COPIED:
4873                case DIFF_STATUS_RENAMED:
4874                        return 0;
4875                default:
4876                        if (p->score)
4877                                return 0;
4878                        if (p->one->mode && p->two->mode &&
4879                            p->one->mode != p->two->mode)
4880                                return 0;
4881                        break;
4882                }
4883        }
4884        return 1;
4885}
4886
4887static const char rename_limit_warning[] =
4888N_("inexact rename detection was skipped due to too many files.");
4889
4890static const char degrade_cc_to_c_warning[] =
4891N_("only found copies from modified paths due to too many files.");
4892
4893static const char rename_limit_advice[] =
4894N_("you may want to set your %s variable to at least "
4895   "%d and retry the command.");
4896
4897void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4898{
4899        if (degraded_cc)
4900                warning(_(degrade_cc_to_c_warning));
4901        else if (needed)
4902                warning(_(rename_limit_warning));
4903        else
4904                return;
4905        if (0 < needed && needed < 32767)
4906                warning(_(rename_limit_advice), varname, needed);
4907}
4908
4909static void diff_flush_patch_all_file_pairs(struct diff_options *o)
4910{
4911        int i;
4912        struct diff_queue_struct *q = &diff_queued_diff;
4913
4914        if (WSEH_NEW & WS_RULE_MASK)
4915                die("BUG: WS rules bit mask overlaps with diff symbol flags");
4916
4917        for (i = 0; i < q->nr; i++) {
4918                struct diff_filepair *p = q->queue[i];
4919                if (check_pair_status(p))
4920                        diff_flush_patch(p, o);
4921        }
4922}
4923
4924void diff_flush(struct diff_options *options)
4925{
4926        struct diff_queue_struct *q = &diff_queued_diff;
4927        int i, output_format = options->output_format;
4928        int separator = 0;
4929        int dirstat_by_line = 0;
4930
4931        /*
4932         * Order: raw, stat, summary, patch
4933         * or:    name/name-status/checkdiff (other bits clear)
4934         */
4935        if (!q->nr)
4936                goto free_queue;
4937
4938        if (output_format & (DIFF_FORMAT_RAW |
4939                             DIFF_FORMAT_NAME |
4940                             DIFF_FORMAT_NAME_STATUS |
4941                             DIFF_FORMAT_CHECKDIFF)) {
4942                for (i = 0; i < q->nr; i++) {
4943                        struct diff_filepair *p = q->queue[i];
4944                        if (check_pair_status(p))
4945                                flush_one_pair(p, options);
4946                }
4947                separator++;
4948        }
4949
4950        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4951                dirstat_by_line = 1;
4952
4953        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4954            dirstat_by_line) {
4955                struct diffstat_t diffstat;
4956
4957                memset(&diffstat, 0, sizeof(struct diffstat_t));
4958                for (i = 0; i < q->nr; i++) {
4959                        struct diff_filepair *p = q->queue[i];
4960                        if (check_pair_status(p))
4961                                diff_flush_stat(p, options, &diffstat);
4962                }
4963                if (output_format & DIFF_FORMAT_NUMSTAT)
4964                        show_numstat(&diffstat, options);
4965                if (output_format & DIFF_FORMAT_DIFFSTAT)
4966                        show_stats(&diffstat, options);
4967                if (output_format & DIFF_FORMAT_SHORTSTAT)
4968                        show_shortstats(&diffstat, options);
4969                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
4970                        show_dirstat_by_line(&diffstat, options);
4971                free_diffstat_info(&diffstat);
4972                separator++;
4973        }
4974        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4975                show_dirstat(options);
4976
4977        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4978                for (i = 0; i < q->nr; i++) {
4979                        diff_summary(options, q->queue[i]);
4980                }
4981                separator++;
4982        }
4983
4984        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4985            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4986            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4987                /*
4988                 * run diff_flush_patch for the exit status. setting
4989                 * options->file to /dev/null should be safe, because we
4990                 * aren't supposed to produce any output anyway.
4991                 */
4992                if (options->close_file)
4993                        fclose(options->file);
4994                options->file = xfopen("/dev/null", "w");
4995                options->close_file = 1;
4996                for (i = 0; i < q->nr; i++) {
4997                        struct diff_filepair *p = q->queue[i];
4998                        if (check_pair_status(p))
4999                                diff_flush_patch(p, options);
5000                        if (options->found_changes)
5001                                break;
5002                }
5003        }
5004
5005        if (output_format & DIFF_FORMAT_PATCH) {
5006                if (separator) {
5007                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5008                        if (options->stat_sep) {
5009                                /* attach patch instead of inline */
5010                                fputs(options->stat_sep, options->file);
5011                        }
5012                }
5013
5014                diff_flush_patch_all_file_pairs(options);
5015        }
5016
5017        if (output_format & DIFF_FORMAT_CALLBACK)
5018                options->format_callback(q, options, options->format_callback_data);
5019
5020        for (i = 0; i < q->nr; i++)
5021                diff_free_filepair(q->queue[i]);
5022free_queue:
5023        free(q->queue);
5024        DIFF_QUEUE_CLEAR(q);
5025        if (options->close_file)
5026                fclose(options->file);
5027
5028        /*
5029         * Report the content-level differences with HAS_CHANGES;
5030         * diff_addremove/diff_change does not set the bit when
5031         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5032         */
5033        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
5034                if (options->found_changes)
5035                        DIFF_OPT_SET(options, HAS_CHANGES);
5036                else
5037                        DIFF_OPT_CLR(options, HAS_CHANGES);
5038        }
5039}
5040
5041static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5042{
5043        return (((p->status == DIFF_STATUS_MODIFIED) &&
5044                 ((p->score &&
5045                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5046                  (!p->score &&
5047                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5048                ((p->status != DIFF_STATUS_MODIFIED) &&
5049                 filter_bit_tst(p->status, options)));
5050}
5051
5052static void diffcore_apply_filter(struct diff_options *options)
5053{
5054        int i;
5055        struct diff_queue_struct *q = &diff_queued_diff;
5056        struct diff_queue_struct outq;
5057
5058        DIFF_QUEUE_CLEAR(&outq);
5059
5060        if (!options->filter)
5061                return;
5062
5063        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
5064                int found;
5065                for (i = found = 0; !found && i < q->nr; i++) {
5066                        if (match_filter(options, q->queue[i]))
5067                                found++;
5068                }
5069                if (found)
5070                        return;
5071
5072                /* otherwise we will clear the whole queue
5073                 * by copying the empty outq at the end of this
5074                 * function, but first clear the current entries
5075                 * in the queue.
5076                 */
5077                for (i = 0; i < q->nr; i++)
5078                        diff_free_filepair(q->queue[i]);
5079        }
5080        else {
5081                /* Only the matching ones */
5082                for (i = 0; i < q->nr; i++) {
5083                        struct diff_filepair *p = q->queue[i];
5084                        if (match_filter(options, p))
5085                                diff_q(&outq, p);
5086                        else
5087                                diff_free_filepair(p);
5088                }
5089        }
5090        free(q->queue);
5091        *q = outq;
5092}
5093
5094/* Check whether two filespecs with the same mode and size are identical */
5095static int diff_filespec_is_identical(struct diff_filespec *one,
5096                                      struct diff_filespec *two)
5097{
5098        if (S_ISGITLINK(one->mode))
5099                return 0;
5100        if (diff_populate_filespec(one, 0))
5101                return 0;
5102        if (diff_populate_filespec(two, 0))
5103                return 0;
5104        return !memcmp(one->data, two->data, one->size);
5105}
5106
5107static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
5108{
5109        if (p->done_skip_stat_unmatch)
5110                return p->skip_stat_unmatch_result;
5111
5112        p->done_skip_stat_unmatch = 1;
5113        p->skip_stat_unmatch_result = 0;
5114        /*
5115         * 1. Entries that come from stat info dirtiness
5116         *    always have both sides (iow, not create/delete),
5117         *    one side of the object name is unknown, with
5118         *    the same mode and size.  Keep the ones that
5119         *    do not match these criteria.  They have real
5120         *    differences.
5121         *
5122         * 2. At this point, the file is known to be modified,
5123         *    with the same mode and size, and the object
5124         *    name of one side is unknown.  Need to inspect
5125         *    the identical contents.
5126         */
5127        if (!DIFF_FILE_VALID(p->one) || /* (1) */
5128            !DIFF_FILE_VALID(p->two) ||
5129            (p->one->oid_valid && p->two->oid_valid) ||
5130            (p->one->mode != p->two->mode) ||
5131            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
5132            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
5133            (p->one->size != p->two->size) ||
5134            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
5135                p->skip_stat_unmatch_result = 1;
5136        return p->skip_stat_unmatch_result;
5137}
5138
5139static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
5140{
5141        int i;
5142        struct diff_queue_struct *q = &diff_queued_diff;
5143        struct diff_queue_struct outq;
5144        DIFF_QUEUE_CLEAR(&outq);
5145
5146        for (i = 0; i < q->nr; i++) {
5147                struct diff_filepair *p = q->queue[i];
5148
5149                if (diff_filespec_check_stat_unmatch(p))
5150                        diff_q(&outq, p);
5151                else {
5152                        /*
5153                         * The caller can subtract 1 from skip_stat_unmatch
5154                         * to determine how many paths were dirty only
5155                         * due to stat info mismatch.
5156                         */
5157                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
5158                                diffopt->skip_stat_unmatch++;
5159                        diff_free_filepair(p);
5160                }
5161        }
5162        free(q->queue);
5163        *q = outq;
5164}
5165
5166static int diffnamecmp(const void *a_, const void *b_)
5167{
5168        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
5169        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
5170        const char *name_a, *name_b;
5171
5172        name_a = a->one ? a->one->path : a->two->path;
5173        name_b = b->one ? b->one->path : b->two->path;
5174        return strcmp(name_a, name_b);
5175}
5176
5177void diffcore_fix_diff_index(struct diff_options *options)
5178{
5179        struct diff_queue_struct *q = &diff_queued_diff;
5180        QSORT(q->queue, q->nr, diffnamecmp);
5181}
5182
5183void diffcore_std(struct diff_options *options)
5184{
5185        /* NOTE please keep the following in sync with diff_tree_combined() */
5186        if (options->skip_stat_unmatch)
5187                diffcore_skip_stat_unmatch(options);
5188        if (!options->found_follow) {
5189                /* See try_to_follow_renames() in tree-diff.c */
5190                if (options->break_opt != -1)
5191                        diffcore_break(options->break_opt);
5192                if (options->detect_rename)
5193                        diffcore_rename(options);
5194                if (options->break_opt != -1)
5195                        diffcore_merge_broken();
5196        }
5197        if (options->pickaxe)
5198                diffcore_pickaxe(options);
5199        if (options->orderfile)
5200                diffcore_order(options->orderfile);
5201        if (!options->found_follow)
5202                /* See try_to_follow_renames() in tree-diff.c */
5203                diff_resolve_rename_copy();
5204        diffcore_apply_filter(options);
5205
5206        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5207                DIFF_OPT_SET(options, HAS_CHANGES);
5208        else
5209                DIFF_OPT_CLR(options, HAS_CHANGES);
5210
5211        options->found_follow = 0;
5212}
5213
5214int diff_result_code(struct diff_options *opt, int status)
5215{
5216        int result = 0;
5217
5218        diff_warn_rename_limit("diff.renameLimit",
5219                               opt->needed_rename_limit,
5220                               opt->degraded_cc_to_c);
5221        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5222            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
5223                return status;
5224        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5225            DIFF_OPT_TST(opt, HAS_CHANGES))
5226                result |= 01;
5227        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
5228            DIFF_OPT_TST(opt, CHECK_FAILED))
5229                result |= 02;
5230        return result;
5231}
5232
5233int diff_can_quit_early(struct diff_options *opt)
5234{
5235        return (DIFF_OPT_TST(opt, QUICK) &&
5236                !opt->filter &&
5237                DIFF_OPT_TST(opt, HAS_CHANGES));
5238}
5239
5240/*
5241 * Shall changes to this submodule be ignored?
5242 *
5243 * Submodule changes can be configured to be ignored separately for each path,
5244 * but that configuration can be overridden from the command line.
5245 */
5246static int is_submodule_ignored(const char *path, struct diff_options *options)
5247{
5248        int ignored = 0;
5249        unsigned orig_flags = options->flags;
5250        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
5251                set_diffopt_flags_from_submodule_config(options, path);
5252        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
5253                ignored = 1;
5254        options->flags = orig_flags;
5255        return ignored;
5256}
5257
5258void diff_addremove(struct diff_options *options,
5259                    int addremove, unsigned mode,
5260                    const struct object_id *oid,
5261                    int oid_valid,
5262                    const char *concatpath, unsigned dirty_submodule)
5263{
5264        struct diff_filespec *one, *two;
5265
5266        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
5267                return;
5268
5269        /* This may look odd, but it is a preparation for
5270         * feeding "there are unchanged files which should
5271         * not produce diffs, but when you are doing copy
5272         * detection you would need them, so here they are"
5273         * entries to the diff-core.  They will be prefixed
5274         * with something like '=' or '*' (I haven't decided
5275         * which but should not make any difference).
5276         * Feeding the same new and old to diff_change()
5277         * also has the same effect.
5278         * Before the final output happens, they are pruned after
5279         * merged into rename/copy pairs as appropriate.
5280         */
5281        if (DIFF_OPT_TST(options, REVERSE_DIFF))
5282                addremove = (addremove == '+' ? '-' :
5283                             addremove == '-' ? '+' : addremove);
5284
5285        if (options->prefix &&
5286            strncmp(concatpath, options->prefix, options->prefix_length))
5287                return;
5288
5289        one = alloc_filespec(concatpath);
5290        two = alloc_filespec(concatpath);
5291
5292        if (addremove != '+')
5293                fill_filespec(one, oid, oid_valid, mode);
5294        if (addremove != '-') {
5295                fill_filespec(two, oid, oid_valid, mode);
5296                two->dirty_submodule = dirty_submodule;
5297        }
5298
5299        diff_queue(&diff_queued_diff, one, two);
5300        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5301                DIFF_OPT_SET(options, HAS_CHANGES);
5302}
5303
5304void diff_change(struct diff_options *options,
5305                 unsigned old_mode, unsigned new_mode,
5306                 const struct object_id *old_oid,
5307                 const struct object_id *new_oid,
5308                 int old_oid_valid, int new_oid_valid,
5309                 const char *concatpath,
5310                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
5311{
5312        struct diff_filespec *one, *two;
5313        struct diff_filepair *p;
5314
5315        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
5316            is_submodule_ignored(concatpath, options))
5317                return;
5318
5319        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
5320                SWAP(old_mode, new_mode);
5321                SWAP(old_oid, new_oid);
5322                SWAP(old_oid_valid, new_oid_valid);
5323                SWAP(old_dirty_submodule, new_dirty_submodule);
5324        }
5325
5326        if (options->prefix &&
5327            strncmp(concatpath, options->prefix, options->prefix_length))
5328                return;
5329
5330        one = alloc_filespec(concatpath);
5331        two = alloc_filespec(concatpath);
5332        fill_filespec(one, old_oid, old_oid_valid, old_mode);
5333        fill_filespec(two, new_oid, new_oid_valid, new_mode);
5334        one->dirty_submodule = old_dirty_submodule;
5335        two->dirty_submodule = new_dirty_submodule;
5336        p = diff_queue(&diff_queued_diff, one, two);
5337
5338        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5339                return;
5340
5341        if (DIFF_OPT_TST(options, QUICK) && options->skip_stat_unmatch &&
5342            !diff_filespec_check_stat_unmatch(p))
5343                return;
5344
5345        DIFF_OPT_SET(options, HAS_CHANGES);
5346}
5347
5348struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
5349{
5350        struct diff_filepair *pair;
5351        struct diff_filespec *one, *two;
5352
5353        if (options->prefix &&
5354            strncmp(path, options->prefix, options->prefix_length))
5355                return NULL;
5356
5357        one = alloc_filespec(path);
5358        two = alloc_filespec(path);
5359        pair = diff_queue(&diff_queued_diff, one, two);
5360        pair->is_unmerged = 1;
5361        return pair;
5362}
5363
5364static char *run_textconv(const char *pgm, struct diff_filespec *spec,
5365                size_t *outsize)
5366{
5367        struct diff_tempfile *temp;
5368        const char *argv[3];
5369        const char **arg = argv;
5370        struct child_process child = CHILD_PROCESS_INIT;
5371        struct strbuf buf = STRBUF_INIT;
5372        int err = 0;
5373
5374        temp = prepare_temp_file(spec->path, spec);
5375        *arg++ = pgm;
5376        *arg++ = temp->name;
5377        *arg = NULL;
5378
5379        child.use_shell = 1;
5380        child.argv = argv;
5381        child.out = -1;
5382        if (start_command(&child)) {
5383                remove_tempfile();
5384                return NULL;
5385        }
5386
5387        if (strbuf_read(&buf, child.out, 0) < 0)
5388                err = error("error reading from textconv command '%s'", pgm);
5389        close(child.out);
5390
5391        if (finish_command(&child) || err) {
5392                strbuf_release(&buf);
5393                remove_tempfile();
5394                return NULL;
5395        }
5396        remove_tempfile();
5397
5398        return strbuf_detach(&buf, outsize);
5399}
5400
5401size_t fill_textconv(struct userdiff_driver *driver,
5402                     struct diff_filespec *df,
5403                     char **outbuf)
5404{
5405        size_t size;
5406
5407        if (!driver) {
5408                if (!DIFF_FILE_VALID(df)) {
5409                        *outbuf = "";
5410                        return 0;
5411                }
5412                if (diff_populate_filespec(df, 0))
5413                        die("unable to read files to diff");
5414                *outbuf = df->data;
5415                return df->size;
5416        }
5417
5418        if (!driver->textconv)
5419                die("BUG: fill_textconv called with non-textconv driver");
5420
5421        if (driver->textconv_cache && df->oid_valid) {
5422                *outbuf = notes_cache_get(driver->textconv_cache,
5423                                          &df->oid,
5424                                          &size);
5425                if (*outbuf)
5426                        return size;
5427        }
5428
5429        *outbuf = run_textconv(driver->textconv, df, &size);
5430        if (!*outbuf)
5431                die("unable to read files to diff");
5432
5433        if (driver->textconv_cache && df->oid_valid) {
5434                /* ignore errors, as we might be in a readonly repository */
5435                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
5436                                size);
5437                /*
5438                 * we could save up changes and flush them all at the end,
5439                 * but we would need an extra call after all diffing is done.
5440                 * Since generating a cache entry is the slow path anyway,
5441                 * this extra overhead probably isn't a big deal.
5442                 */
5443                notes_cache_write(driver->textconv_cache);
5444        }
5445
5446        return size;
5447}
5448
5449int textconv_object(const char *path,
5450                    unsigned mode,
5451                    const struct object_id *oid,
5452                    int oid_valid,
5453                    char **buf,
5454                    unsigned long *buf_size)
5455{
5456        struct diff_filespec *df;
5457        struct userdiff_driver *textconv;
5458
5459        df = alloc_filespec(path);
5460        fill_filespec(df, oid, oid_valid, mode);
5461        textconv = get_textconv(df);
5462        if (!textconv) {
5463                free_filespec(df);
5464                return 0;
5465        }
5466
5467        *buf_size = fill_textconv(textconv, df, buf);
5468        free_filespec(df);
5469        return 1;
5470}
5471
5472void setup_diff_pager(struct diff_options *opt)
5473{
5474        /*
5475         * If the user asked for our exit code, then either they want --quiet
5476         * or --exit-code. We should definitely not bother with a pager in the
5477         * former case, as we will generate no output. Since we still properly
5478         * report our exit code even when a pager is run, we _could_ run a
5479         * pager with --exit-code. But since we have not done so historically,
5480         * and because it is easy to find people oneline advising "git diff
5481         * --exit-code" in hooks and other scripts, we do not do so.
5482         */
5483        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5484            check_pager_config("diff") != 0)
5485                setup_pager();
5486}