diff.con commit diff.c: convert emit_binary_diff_body to use emit_diff_symbol (4eed0eb)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "config.h"
   6#include "tempfile.h"
   7#include "quote.h"
   8#include "diff.h"
   9#include "diffcore.h"
  10#include "delta.h"
  11#include "xdiff-interface.h"
  12#include "color.h"
  13#include "attr.h"
  14#include "run-command.h"
  15#include "utf8.h"
  16#include "userdiff.h"
  17#include "submodule-config.h"
  18#include "submodule.h"
  19#include "ll-merge.h"
  20#include "string-list.h"
  21#include "argv-array.h"
  22#include "graph.h"
  23
  24#ifdef NO_FAST_WORKING_DIRECTORY
  25#define FAST_WORKING_DIRECTORY 0
  26#else
  27#define FAST_WORKING_DIRECTORY 1
  28#endif
  29
  30static int diff_detect_rename_default;
  31static int diff_indent_heuristic = 1;
  32static int diff_rename_limit_default = 400;
  33static int diff_suppress_blank_empty;
  34static int diff_use_color_default = -1;
  35static int diff_context_default = 3;
  36static int diff_interhunk_context_default;
  37static const char *diff_word_regex_cfg;
  38static const char *external_diff_cmd_cfg;
  39static const char *diff_order_file_cfg;
  40int diff_auto_refresh_index = 1;
  41static int diff_mnemonic_prefix;
  42static int diff_no_prefix;
  43static int diff_stat_graph_width;
  44static int diff_dirstat_permille_default = 30;
  45static struct diff_options default_diff_options;
  46static long diff_algorithm;
  47static unsigned ws_error_highlight_default = WSEH_NEW;
  48
  49static char diff_colors[][COLOR_MAXLEN] = {
  50        GIT_COLOR_RESET,
  51        GIT_COLOR_NORMAL,       /* CONTEXT */
  52        GIT_COLOR_BOLD,         /* METAINFO */
  53        GIT_COLOR_CYAN,         /* FRAGINFO */
  54        GIT_COLOR_RED,          /* OLD */
  55        GIT_COLOR_GREEN,        /* NEW */
  56        GIT_COLOR_YELLOW,       /* COMMIT */
  57        GIT_COLOR_BG_RED,       /* WHITESPACE */
  58        GIT_COLOR_NORMAL,       /* FUNCINFO */
  59};
  60
  61static NORETURN void die_want_option(const char *option_name)
  62{
  63        die(_("option '%s' requires a value"), option_name);
  64}
  65
  66static int parse_diff_color_slot(const char *var)
  67{
  68        if (!strcasecmp(var, "context") || !strcasecmp(var, "plain"))
  69                return DIFF_CONTEXT;
  70        if (!strcasecmp(var, "meta"))
  71                return DIFF_METAINFO;
  72        if (!strcasecmp(var, "frag"))
  73                return DIFF_FRAGINFO;
  74        if (!strcasecmp(var, "old"))
  75                return DIFF_FILE_OLD;
  76        if (!strcasecmp(var, "new"))
  77                return DIFF_FILE_NEW;
  78        if (!strcasecmp(var, "commit"))
  79                return DIFF_COMMIT;
  80        if (!strcasecmp(var, "whitespace"))
  81                return DIFF_WHITESPACE;
  82        if (!strcasecmp(var, "func"))
  83                return DIFF_FUNCINFO;
  84        return -1;
  85}
  86
  87static int parse_dirstat_params(struct diff_options *options, const char *params_string,
  88                                struct strbuf *errmsg)
  89{
  90        char *params_copy = xstrdup(params_string);
  91        struct string_list params = STRING_LIST_INIT_NODUP;
  92        int ret = 0;
  93        int i;
  94
  95        if (*params_copy)
  96                string_list_split_in_place(&params, params_copy, ',', -1);
  97        for (i = 0; i < params.nr; i++) {
  98                const char *p = params.items[i].string;
  99                if (!strcmp(p, "changes")) {
 100                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
 101                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
 102                } else if (!strcmp(p, "lines")) {
 103                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
 104                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
 105                } else if (!strcmp(p, "files")) {
 106                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
 107                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
 108                } else if (!strcmp(p, "noncumulative")) {
 109                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
 110                } else if (!strcmp(p, "cumulative")) {
 111                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
 112                } else if (isdigit(*p)) {
 113                        char *end;
 114                        int permille = strtoul(p, &end, 10) * 10;
 115                        if (*end == '.' && isdigit(*++end)) {
 116                                /* only use first digit */
 117                                permille += *end - '0';
 118                                /* .. and ignore any further digits */
 119                                while (isdigit(*++end))
 120                                        ; /* nothing */
 121                        }
 122                        if (!*end)
 123                                options->dirstat_permille = permille;
 124                        else {
 125                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 126                                            p);
 127                                ret++;
 128                        }
 129                } else {
 130                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 131                        ret++;
 132                }
 133
 134        }
 135        string_list_clear(&params, 0);
 136        free(params_copy);
 137        return ret;
 138}
 139
 140static int parse_submodule_params(struct diff_options *options, const char *value)
 141{
 142        if (!strcmp(value, "log"))
 143                options->submodule_format = DIFF_SUBMODULE_LOG;
 144        else if (!strcmp(value, "short"))
 145                options->submodule_format = DIFF_SUBMODULE_SHORT;
 146        else if (!strcmp(value, "diff"))
 147                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 148        else
 149                return -1;
 150        return 0;
 151}
 152
 153static int git_config_rename(const char *var, const char *value)
 154{
 155        if (!value)
 156                return DIFF_DETECT_RENAME;
 157        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 158                return  DIFF_DETECT_COPY;
 159        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 160}
 161
 162long parse_algorithm_value(const char *value)
 163{
 164        if (!value)
 165                return -1;
 166        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 167                return 0;
 168        else if (!strcasecmp(value, "minimal"))
 169                return XDF_NEED_MINIMAL;
 170        else if (!strcasecmp(value, "patience"))
 171                return XDF_PATIENCE_DIFF;
 172        else if (!strcasecmp(value, "histogram"))
 173                return XDF_HISTOGRAM_DIFF;
 174        return -1;
 175}
 176
 177static int parse_one_token(const char **arg, const char *token)
 178{
 179        const char *rest;
 180        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 181                *arg = rest;
 182                return 1;
 183        }
 184        return 0;
 185}
 186
 187static int parse_ws_error_highlight(const char *arg)
 188{
 189        const char *orig_arg = arg;
 190        unsigned val = 0;
 191
 192        while (*arg) {
 193                if (parse_one_token(&arg, "none"))
 194                        val = 0;
 195                else if (parse_one_token(&arg, "default"))
 196                        val = WSEH_NEW;
 197                else if (parse_one_token(&arg, "all"))
 198                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 199                else if (parse_one_token(&arg, "new"))
 200                        val |= WSEH_NEW;
 201                else if (parse_one_token(&arg, "old"))
 202                        val |= WSEH_OLD;
 203                else if (parse_one_token(&arg, "context"))
 204                        val |= WSEH_CONTEXT;
 205                else {
 206                        return -1 - (int)(arg - orig_arg);
 207                }
 208                if (*arg)
 209                        arg++;
 210        }
 211        return val;
 212}
 213
 214/*
 215 * These are to give UI layer defaults.
 216 * The core-level commands such as git-diff-files should
 217 * never be affected by the setting of diff.renames
 218 * the user happens to have in the configuration file.
 219 */
 220void init_diff_ui_defaults(void)
 221{
 222        diff_detect_rename_default = 1;
 223}
 224
 225int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 226{
 227        if (!strcmp(var, "diff.indentheuristic"))
 228                diff_indent_heuristic = git_config_bool(var, value);
 229        return 0;
 230}
 231
 232int git_diff_ui_config(const char *var, const char *value, void *cb)
 233{
 234        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 235                diff_use_color_default = git_config_colorbool(var, value);
 236                return 0;
 237        }
 238        if (!strcmp(var, "diff.context")) {
 239                diff_context_default = git_config_int(var, value);
 240                if (diff_context_default < 0)
 241                        return -1;
 242                return 0;
 243        }
 244        if (!strcmp(var, "diff.interhunkcontext")) {
 245                diff_interhunk_context_default = git_config_int(var, value);
 246                if (diff_interhunk_context_default < 0)
 247                        return -1;
 248                return 0;
 249        }
 250        if (!strcmp(var, "diff.renames")) {
 251                diff_detect_rename_default = git_config_rename(var, value);
 252                return 0;
 253        }
 254        if (!strcmp(var, "diff.autorefreshindex")) {
 255                diff_auto_refresh_index = git_config_bool(var, value);
 256                return 0;
 257        }
 258        if (!strcmp(var, "diff.mnemonicprefix")) {
 259                diff_mnemonic_prefix = git_config_bool(var, value);
 260                return 0;
 261        }
 262        if (!strcmp(var, "diff.noprefix")) {
 263                diff_no_prefix = git_config_bool(var, value);
 264                return 0;
 265        }
 266        if (!strcmp(var, "diff.statgraphwidth")) {
 267                diff_stat_graph_width = git_config_int(var, value);
 268                return 0;
 269        }
 270        if (!strcmp(var, "diff.external"))
 271                return git_config_string(&external_diff_cmd_cfg, var, value);
 272        if (!strcmp(var, "diff.wordregex"))
 273                return git_config_string(&diff_word_regex_cfg, var, value);
 274        if (!strcmp(var, "diff.orderfile"))
 275                return git_config_pathname(&diff_order_file_cfg, var, value);
 276
 277        if (!strcmp(var, "diff.ignoresubmodules"))
 278                handle_ignore_submodules_arg(&default_diff_options, value);
 279
 280        if (!strcmp(var, "diff.submodule")) {
 281                if (parse_submodule_params(&default_diff_options, value))
 282                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 283                                value);
 284                return 0;
 285        }
 286
 287        if (!strcmp(var, "diff.algorithm")) {
 288                diff_algorithm = parse_algorithm_value(value);
 289                if (diff_algorithm < 0)
 290                        return -1;
 291                return 0;
 292        }
 293
 294        if (!strcmp(var, "diff.wserrorhighlight")) {
 295                int val = parse_ws_error_highlight(value);
 296                if (val < 0)
 297                        return -1;
 298                ws_error_highlight_default = val;
 299                return 0;
 300        }
 301
 302        if (git_color_config(var, value, cb) < 0)
 303                return -1;
 304
 305        return git_diff_basic_config(var, value, cb);
 306}
 307
 308int git_diff_basic_config(const char *var, const char *value, void *cb)
 309{
 310        const char *name;
 311
 312        if (!strcmp(var, "diff.renamelimit")) {
 313                diff_rename_limit_default = git_config_int(var, value);
 314                return 0;
 315        }
 316
 317        if (userdiff_config(var, value) < 0)
 318                return -1;
 319
 320        if (skip_prefix(var, "diff.color.", &name) ||
 321            skip_prefix(var, "color.diff.", &name)) {
 322                int slot = parse_diff_color_slot(name);
 323                if (slot < 0)
 324                        return 0;
 325                if (!value)
 326                        return config_error_nonbool(var);
 327                return color_parse(value, diff_colors[slot]);
 328        }
 329
 330        /* like GNU diff's --suppress-blank-empty option  */
 331        if (!strcmp(var, "diff.suppressblankempty") ||
 332                        /* for backwards compatibility */
 333                        !strcmp(var, "diff.suppress-blank-empty")) {
 334                diff_suppress_blank_empty = git_config_bool(var, value);
 335                return 0;
 336        }
 337
 338        if (!strcmp(var, "diff.dirstat")) {
 339                struct strbuf errmsg = STRBUF_INIT;
 340                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 341                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 342                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 343                                errmsg.buf);
 344                strbuf_release(&errmsg);
 345                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 346                return 0;
 347        }
 348
 349        if (starts_with(var, "submodule."))
 350                return parse_submodule_config_option(var, value);
 351
 352        if (git_diff_heuristic_config(var, value, cb) < 0)
 353                return -1;
 354
 355        return git_default_config(var, value, cb);
 356}
 357
 358static char *quote_two(const char *one, const char *two)
 359{
 360        int need_one = quote_c_style(one, NULL, NULL, 1);
 361        int need_two = quote_c_style(two, NULL, NULL, 1);
 362        struct strbuf res = STRBUF_INIT;
 363
 364        if (need_one + need_two) {
 365                strbuf_addch(&res, '"');
 366                quote_c_style(one, &res, NULL, 1);
 367                quote_c_style(two, &res, NULL, 1);
 368                strbuf_addch(&res, '"');
 369        } else {
 370                strbuf_addstr(&res, one);
 371                strbuf_addstr(&res, two);
 372        }
 373        return strbuf_detach(&res, NULL);
 374}
 375
 376static const char *external_diff(void)
 377{
 378        static const char *external_diff_cmd = NULL;
 379        static int done_preparing = 0;
 380
 381        if (done_preparing)
 382                return external_diff_cmd;
 383        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 384        if (!external_diff_cmd)
 385                external_diff_cmd = external_diff_cmd_cfg;
 386        done_preparing = 1;
 387        return external_diff_cmd;
 388}
 389
 390/*
 391 * Keep track of files used for diffing. Sometimes such an entry
 392 * refers to a temporary file, sometimes to an existing file, and
 393 * sometimes to "/dev/null".
 394 */
 395static struct diff_tempfile {
 396        /*
 397         * filename external diff should read from, or NULL if this
 398         * entry is currently not in use:
 399         */
 400        const char *name;
 401
 402        char hex[GIT_MAX_HEXSZ + 1];
 403        char mode[10];
 404
 405        /*
 406         * If this diff_tempfile instance refers to a temporary file,
 407         * this tempfile object is used to manage its lifetime.
 408         */
 409        struct tempfile tempfile;
 410} diff_temp[2];
 411
 412typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 413
 414struct emit_callback {
 415        int color_diff;
 416        unsigned ws_rule;
 417        int blank_at_eof_in_preimage;
 418        int blank_at_eof_in_postimage;
 419        int lno_in_preimage;
 420        int lno_in_postimage;
 421        sane_truncate_fn truncate;
 422        const char **label_path;
 423        struct diff_words_data *diff_words;
 424        struct diff_options *opt;
 425        struct strbuf *header;
 426};
 427
 428static int count_lines(const char *data, int size)
 429{
 430        int count, ch, completely_empty = 1, nl_just_seen = 0;
 431        count = 0;
 432        while (0 < size--) {
 433                ch = *data++;
 434                if (ch == '\n') {
 435                        count++;
 436                        nl_just_seen = 1;
 437                        completely_empty = 0;
 438                }
 439                else {
 440                        nl_just_seen = 0;
 441                        completely_empty = 0;
 442                }
 443        }
 444        if (completely_empty)
 445                return 0;
 446        if (!nl_just_seen)
 447                count++; /* no trailing newline */
 448        return count;
 449}
 450
 451static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 452{
 453        if (!DIFF_FILE_VALID(one)) {
 454                mf->ptr = (char *)""; /* does not matter */
 455                mf->size = 0;
 456                return 0;
 457        }
 458        else if (diff_populate_filespec(one, 0))
 459                return -1;
 460
 461        mf->ptr = one->data;
 462        mf->size = one->size;
 463        return 0;
 464}
 465
 466/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 467static unsigned long diff_filespec_size(struct diff_filespec *one)
 468{
 469        if (!DIFF_FILE_VALID(one))
 470                return 0;
 471        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 472        return one->size;
 473}
 474
 475static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 476{
 477        char *ptr = mf->ptr;
 478        long size = mf->size;
 479        int cnt = 0;
 480
 481        if (!size)
 482                return cnt;
 483        ptr += size - 1; /* pointing at the very end */
 484        if (*ptr != '\n')
 485                ; /* incomplete line */
 486        else
 487                ptr--; /* skip the last LF */
 488        while (mf->ptr < ptr) {
 489                char *prev_eol;
 490                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 491                        if (*prev_eol == '\n')
 492                                break;
 493                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 494                        break;
 495                cnt++;
 496                ptr = prev_eol - 1;
 497        }
 498        return cnt;
 499}
 500
 501static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 502                               struct emit_callback *ecbdata)
 503{
 504        int l1, l2, at;
 505        unsigned ws_rule = ecbdata->ws_rule;
 506        l1 = count_trailing_blank(mf1, ws_rule);
 507        l2 = count_trailing_blank(mf2, ws_rule);
 508        if (l2 <= l1) {
 509                ecbdata->blank_at_eof_in_preimage = 0;
 510                ecbdata->blank_at_eof_in_postimage = 0;
 511                return;
 512        }
 513        at = count_lines(mf1->ptr, mf1->size);
 514        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 515
 516        at = count_lines(mf2->ptr, mf2->size);
 517        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 518}
 519
 520static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 521                        int first, const char *line, int len)
 522{
 523        int has_trailing_newline, has_trailing_carriage_return;
 524        int nofirst;
 525        FILE *file = o->file;
 526
 527        fputs(diff_line_prefix(o), file);
 528
 529        if (len == 0) {
 530                has_trailing_newline = (first == '\n');
 531                has_trailing_carriage_return = (!has_trailing_newline &&
 532                                                (first == '\r'));
 533                nofirst = has_trailing_newline || has_trailing_carriage_return;
 534        } else {
 535                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 536                if (has_trailing_newline)
 537                        len--;
 538                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 539                if (has_trailing_carriage_return)
 540                        len--;
 541                nofirst = 0;
 542        }
 543
 544        if (len || !nofirst) {
 545                fputs(set, file);
 546                if (!nofirst)
 547                        fputc(first, file);
 548                fwrite(line, len, 1, file);
 549                fputs(reset, file);
 550        }
 551        if (has_trailing_carriage_return)
 552                fputc('\r', file);
 553        if (has_trailing_newline)
 554                fputc('\n', file);
 555}
 556
 557static void emit_line(struct diff_options *o, const char *set, const char *reset,
 558                      const char *line, int len)
 559{
 560        emit_line_0(o, set, reset, line[0], line+1, len-1);
 561}
 562
 563enum diff_symbol {
 564        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 565        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 566        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 567        DIFF_SYMBOL_BINARY_DIFF_BODY,
 568        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 569        DIFF_SYMBOL_SUBMODULE_ADD,
 570        DIFF_SYMBOL_SUBMODULE_DEL,
 571        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 572        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 573        DIFF_SYMBOL_SUBMODULE_HEADER,
 574        DIFF_SYMBOL_SUBMODULE_ERROR,
 575        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 576        DIFF_SYMBOL_REWRITE_DIFF,
 577        DIFF_SYMBOL_BINARY_FILES,
 578        DIFF_SYMBOL_HEADER,
 579        DIFF_SYMBOL_FILEPAIR_PLUS,
 580        DIFF_SYMBOL_FILEPAIR_MINUS,
 581        DIFF_SYMBOL_WORDS_PORCELAIN,
 582        DIFF_SYMBOL_WORDS,
 583        DIFF_SYMBOL_CONTEXT,
 584        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 585        DIFF_SYMBOL_PLUS,
 586        DIFF_SYMBOL_MINUS,
 587        DIFF_SYMBOL_NO_LF_EOF,
 588        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 589        DIFF_SYMBOL_CONTEXT_MARKER,
 590        DIFF_SYMBOL_SEPARATOR
 591};
 592/*
 593 * Flags for content lines:
 594 * 0..12 are whitespace rules
 595 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 596 * 16 is marking if the line is blank at EOF
 597 */
 598#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF (1<<16)
 599#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 600
 601static void emit_line_ws_markup(struct diff_options *o,
 602                                const char *set, const char *reset,
 603                                const char *line, int len, char sign,
 604                                unsigned ws_rule, int blank_at_eof)
 605{
 606        const char *ws = NULL;
 607
 608        if (o->ws_error_highlight & ws_rule) {
 609                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
 610                if (!*ws)
 611                        ws = NULL;
 612        }
 613
 614        if (!ws)
 615                emit_line_0(o, set, reset, sign, line, len);
 616        else if (blank_at_eof)
 617                /* Blank line at EOF - paint '+' as well */
 618                emit_line_0(o, ws, reset, sign, line, len);
 619        else {
 620                /* Emit just the prefix, then the rest. */
 621                emit_line_0(o, set, reset, sign, "", 0);
 622                ws_check_emit(line, len, ws_rule,
 623                              o->file, set, reset, ws);
 624        }
 625}
 626
 627static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
 628                             const char *line, int len, unsigned flags)
 629{
 630        static const char *nneof = " No newline at end of file\n";
 631        const char *context, *reset, *set, *meta, *fraginfo;
 632        switch (s) {
 633        case DIFF_SYMBOL_NO_LF_EOF:
 634                context = diff_get_color_opt(o, DIFF_CONTEXT);
 635                reset = diff_get_color_opt(o, DIFF_RESET);
 636                putc('\n', o->file);
 637                emit_line_0(o, context, reset, '\\',
 638                            nneof, strlen(nneof));
 639                break;
 640        case DIFF_SYMBOL_SUBMODULE_HEADER:
 641        case DIFF_SYMBOL_SUBMODULE_ERROR:
 642        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
 643        case DIFF_SYMBOL_BINARY_DIFF_BODY:
 644        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
 645                emit_line(o, "", "", line, len);
 646                break;
 647        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
 648        case DIFF_SYMBOL_CONTEXT_MARKER:
 649                context = diff_get_color_opt(o, DIFF_CONTEXT);
 650                reset = diff_get_color_opt(o, DIFF_RESET);
 651                emit_line(o, context, reset, line, len);
 652                break;
 653        case DIFF_SYMBOL_SEPARATOR:
 654                fprintf(o->file, "%s%c",
 655                        diff_line_prefix(o),
 656                        o->line_termination);
 657                break;
 658        case DIFF_SYMBOL_CONTEXT:
 659                set = diff_get_color_opt(o, DIFF_CONTEXT);
 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), 0);
 663                break;
 664        case DIFF_SYMBOL_PLUS:
 665                set = diff_get_color_opt(o, DIFF_FILE_NEW);
 666                reset = diff_get_color_opt(o, DIFF_RESET);
 667                emit_line_ws_markup(o, set, reset, line, len, '+',
 668                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
 669                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
 670                break;
 671        case DIFF_SYMBOL_MINUS:
 672                set = diff_get_color_opt(o, DIFF_FILE_OLD);
 673                reset = diff_get_color_opt(o, DIFF_RESET);
 674                emit_line_ws_markup(o, set, reset, line, len, '-',
 675                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
 676                break;
 677        case DIFF_SYMBOL_WORDS_PORCELAIN:
 678                context = diff_get_color_opt(o, DIFF_CONTEXT);
 679                reset = diff_get_color_opt(o, DIFF_RESET);
 680                emit_line(o, context, reset, line, len);
 681                fputs("~\n", o->file);
 682                break;
 683        case DIFF_SYMBOL_WORDS:
 684                context = diff_get_color_opt(o, DIFF_CONTEXT);
 685                reset = diff_get_color_opt(o, DIFF_RESET);
 686                /*
 687                 * Skip the prefix character, if any.  With
 688                 * diff_suppress_blank_empty, there may be
 689                 * none.
 690                 */
 691                if (line[0] != '\n') {
 692                        line++;
 693                        len--;
 694                }
 695                emit_line(o, context, reset, line, len);
 696                break;
 697        case DIFF_SYMBOL_FILEPAIR_PLUS:
 698                meta = diff_get_color_opt(o, DIFF_METAINFO);
 699                reset = diff_get_color_opt(o, DIFF_RESET);
 700                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
 701                        line, reset,
 702                        strchr(line, ' ') ? "\t" : "");
 703                break;
 704        case DIFF_SYMBOL_FILEPAIR_MINUS:
 705                meta = diff_get_color_opt(o, DIFF_METAINFO);
 706                reset = diff_get_color_opt(o, DIFF_RESET);
 707                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
 708                        line, reset,
 709                        strchr(line, ' ') ? "\t" : "");
 710                break;
 711        case DIFF_SYMBOL_BINARY_FILES:
 712        case DIFF_SYMBOL_HEADER:
 713                fprintf(o->file, "%s", line);
 714                break;
 715        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
 716                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
 717                break;
 718        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
 719                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
 720                break;
 721        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
 722                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
 723                break;
 724        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
 725                fputs(diff_line_prefix(o), o->file);
 726                fputc('\n', o->file);
 727                break;
 728        case DIFF_SYMBOL_REWRITE_DIFF:
 729                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 730                reset = diff_get_color_opt(o, DIFF_RESET);
 731                emit_line(o, fraginfo, reset, line, len);
 732                break;
 733        case DIFF_SYMBOL_SUBMODULE_ADD:
 734                set = diff_get_color_opt(o, DIFF_FILE_NEW);
 735                reset = diff_get_color_opt(o, DIFF_RESET);
 736                emit_line(o, set, reset, line, len);
 737                break;
 738        case DIFF_SYMBOL_SUBMODULE_DEL:
 739                set = diff_get_color_opt(o, DIFF_FILE_OLD);
 740                reset = diff_get_color_opt(o, DIFF_RESET);
 741                emit_line(o, set, reset, line, len);
 742                break;
 743        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
 744                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
 745                        diff_line_prefix(o), line);
 746                break;
 747        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
 748                fprintf(o->file, "%sSubmodule %s contains modified content\n",
 749                        diff_line_prefix(o), line);
 750                break;
 751        default:
 752                die("BUG: unknown diff symbol");
 753        }
 754}
 755
 756void diff_emit_submodule_del(struct diff_options *o, const char *line)
 757{
 758        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
 759}
 760
 761void diff_emit_submodule_add(struct diff_options *o, const char *line)
 762{
 763        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
 764}
 765
 766void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
 767{
 768        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 769                         path, strlen(path), 0);
 770}
 771
 772void diff_emit_submodule_modified(struct diff_options *o, const char *path)
 773{
 774        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
 775                         path, strlen(path), 0);
 776}
 777
 778void diff_emit_submodule_header(struct diff_options *o, const char *header)
 779{
 780        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
 781                         header, strlen(header), 0);
 782}
 783
 784void diff_emit_submodule_error(struct diff_options *o, const char *err)
 785{
 786        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
 787}
 788
 789void diff_emit_submodule_pipethrough(struct diff_options *o,
 790                                     const char *line, int len)
 791{
 792        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
 793}
 794
 795static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 796{
 797        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 798              ecbdata->blank_at_eof_in_preimage &&
 799              ecbdata->blank_at_eof_in_postimage &&
 800              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 801              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 802                return 0;
 803        return ws_blank_line(line, len, ecbdata->ws_rule);
 804}
 805
 806static void emit_add_line(const char *reset,
 807                          struct emit_callback *ecbdata,
 808                          const char *line, int len)
 809{
 810        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
 811        if (new_blank_line_at_eof(ecbdata, line, len))
 812                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
 813
 814        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
 815}
 816
 817static void emit_del_line(const char *reset,
 818                          struct emit_callback *ecbdata,
 819                          const char *line, int len)
 820{
 821        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
 822        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
 823}
 824
 825static void emit_context_line(const char *reset,
 826                              struct emit_callback *ecbdata,
 827                              const char *line, int len)
 828{
 829        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
 830        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
 831}
 832
 833static void emit_hunk_header(struct emit_callback *ecbdata,
 834                             const char *line, int len)
 835{
 836        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
 837        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 838        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 839        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 840        static const char atat[2] = { '@', '@' };
 841        const char *cp, *ep;
 842        struct strbuf msgbuf = STRBUF_INIT;
 843        int org_len = len;
 844        int i = 1;
 845
 846        /*
 847         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 848         * it always is at least 10 bytes long.
 849         */
 850        if (len < 10 ||
 851            memcmp(line, atat, 2) ||
 852            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 853                emit_diff_symbol(ecbdata->opt,
 854                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
 855                return;
 856        }
 857        ep += 2; /* skip over @@ */
 858
 859        /* The hunk header in fraginfo color */
 860        strbuf_addstr(&msgbuf, frag);
 861        strbuf_add(&msgbuf, line, ep - line);
 862        strbuf_addstr(&msgbuf, reset);
 863
 864        /*
 865         * trailing "\r\n"
 866         */
 867        for ( ; i < 3; i++)
 868                if (line[len - i] == '\r' || line[len - i] == '\n')
 869                        len--;
 870
 871        /* blank before the func header */
 872        for (cp = ep; ep - line < len; ep++)
 873                if (*ep != ' ' && *ep != '\t')
 874                        break;
 875        if (ep != cp) {
 876                strbuf_addstr(&msgbuf, context);
 877                strbuf_add(&msgbuf, cp, ep - cp);
 878                strbuf_addstr(&msgbuf, reset);
 879        }
 880
 881        if (ep < line + len) {
 882                strbuf_addstr(&msgbuf, func);
 883                strbuf_add(&msgbuf, ep, line + len - ep);
 884                strbuf_addstr(&msgbuf, reset);
 885        }
 886
 887        strbuf_add(&msgbuf, line + len, org_len - len);
 888        strbuf_complete_line(&msgbuf);
 889        emit_diff_symbol(ecbdata->opt,
 890                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
 891        strbuf_release(&msgbuf);
 892}
 893
 894static struct diff_tempfile *claim_diff_tempfile(void) {
 895        int i;
 896        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 897                if (!diff_temp[i].name)
 898                        return diff_temp + i;
 899        die("BUG: diff is failing to clean up its tempfiles");
 900}
 901
 902static void remove_tempfile(void)
 903{
 904        int i;
 905        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 906                if (is_tempfile_active(&diff_temp[i].tempfile))
 907                        delete_tempfile(&diff_temp[i].tempfile);
 908                diff_temp[i].name = NULL;
 909        }
 910}
 911
 912static void add_line_count(struct strbuf *out, int count)
 913{
 914        switch (count) {
 915        case 0:
 916                strbuf_addstr(out, "0,0");
 917                break;
 918        case 1:
 919                strbuf_addstr(out, "1");
 920                break;
 921        default:
 922                strbuf_addf(out, "1,%d", count);
 923                break;
 924        }
 925}
 926
 927static void emit_rewrite_lines(struct emit_callback *ecb,
 928                               int prefix, const char *data, int size)
 929{
 930        const char *endp = NULL;
 931        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 932
 933        while (0 < size) {
 934                int len;
 935
 936                endp = memchr(data, '\n', size);
 937                len = endp ? (endp - data + 1) : size;
 938                if (prefix != '+') {
 939                        ecb->lno_in_preimage++;
 940                        emit_del_line(reset, ecb, data, len);
 941                } else {
 942                        ecb->lno_in_postimage++;
 943                        emit_add_line(reset, ecb, data, len);
 944                }
 945                size -= len;
 946                data += len;
 947        }
 948        if (!endp)
 949                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
 950}
 951
 952static void emit_rewrite_diff(const char *name_a,
 953                              const char *name_b,
 954                              struct diff_filespec *one,
 955                              struct diff_filespec *two,
 956                              struct userdiff_driver *textconv_one,
 957                              struct userdiff_driver *textconv_two,
 958                              struct diff_options *o)
 959{
 960        int lc_a, lc_b;
 961        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 962        const char *a_prefix, *b_prefix;
 963        char *data_one, *data_two;
 964        size_t size_one, size_two;
 965        struct emit_callback ecbdata;
 966        struct strbuf out = STRBUF_INIT;
 967
 968        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 969                a_prefix = o->b_prefix;
 970                b_prefix = o->a_prefix;
 971        } else {
 972                a_prefix = o->a_prefix;
 973                b_prefix = o->b_prefix;
 974        }
 975
 976        name_a += (*name_a == '/');
 977        name_b += (*name_b == '/');
 978
 979        strbuf_reset(&a_name);
 980        strbuf_reset(&b_name);
 981        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 982        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 983
 984        size_one = fill_textconv(textconv_one, one, &data_one);
 985        size_two = fill_textconv(textconv_two, two, &data_two);
 986
 987        memset(&ecbdata, 0, sizeof(ecbdata));
 988        ecbdata.color_diff = want_color(o->use_color);
 989        ecbdata.ws_rule = whitespace_rule(name_b);
 990        ecbdata.opt = o;
 991        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 992                mmfile_t mf1, mf2;
 993                mf1.ptr = (char *)data_one;
 994                mf2.ptr = (char *)data_two;
 995                mf1.size = size_one;
 996                mf2.size = size_two;
 997                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 998        }
 999        ecbdata.lno_in_preimage = 1;
1000        ecbdata.lno_in_postimage = 1;
1001
1002        lc_a = count_lines(data_one, size_one);
1003        lc_b = count_lines(data_two, size_two);
1004
1005        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1006                         a_name.buf, a_name.len, 0);
1007        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1008                         b_name.buf, b_name.len, 0);
1009
1010        strbuf_addstr(&out, "@@ -");
1011        if (!o->irreversible_delete)
1012                add_line_count(&out, lc_a);
1013        else
1014                strbuf_addstr(&out, "?,?");
1015        strbuf_addstr(&out, " +");
1016        add_line_count(&out, lc_b);
1017        strbuf_addstr(&out, " @@\n");
1018        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1019        strbuf_release(&out);
1020
1021        if (lc_a && !o->irreversible_delete)
1022                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1023        if (lc_b)
1024                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1025        if (textconv_one)
1026                free((char *)data_one);
1027        if (textconv_two)
1028                free((char *)data_two);
1029}
1030
1031struct diff_words_buffer {
1032        mmfile_t text;
1033        long alloc;
1034        struct diff_words_orig {
1035                const char *begin, *end;
1036        } *orig;
1037        int orig_nr, orig_alloc;
1038};
1039
1040static void diff_words_append(char *line, unsigned long len,
1041                struct diff_words_buffer *buffer)
1042{
1043        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1044        line++;
1045        len--;
1046        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1047        buffer->text.size += len;
1048        buffer->text.ptr[buffer->text.size] = '\0';
1049}
1050
1051struct diff_words_style_elem {
1052        const char *prefix;
1053        const char *suffix;
1054        const char *color; /* NULL; filled in by the setup code if
1055                            * color is enabled */
1056};
1057
1058struct diff_words_style {
1059        enum diff_words_type type;
1060        struct diff_words_style_elem new, old, ctx;
1061        const char *newline;
1062};
1063
1064static struct diff_words_style diff_words_styles[] = {
1065        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1066        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1067        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1068};
1069
1070struct diff_words_data {
1071        struct diff_words_buffer minus, plus;
1072        const char *current_plus;
1073        int last_minus;
1074        struct diff_options *opt;
1075        regex_t *word_regex;
1076        enum diff_words_type type;
1077        struct diff_words_style *style;
1078};
1079
1080static int fn_out_diff_words_write_helper(FILE *fp,
1081                                          struct diff_words_style_elem *st_el,
1082                                          const char *newline,
1083                                          size_t count, const char *buf,
1084                                          const char *line_prefix)
1085{
1086        int print = 0;
1087
1088        while (count) {
1089                char *p = memchr(buf, '\n', count);
1090                if (print)
1091                        fputs(line_prefix, fp);
1092                if (p != buf) {
1093                        if (st_el->color && fputs(st_el->color, fp) < 0)
1094                                return -1;
1095                        if (fputs(st_el->prefix, fp) < 0 ||
1096                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
1097                            fputs(st_el->suffix, fp) < 0)
1098                                return -1;
1099                        if (st_el->color && *st_el->color
1100                            && fputs(GIT_COLOR_RESET, fp) < 0)
1101                                return -1;
1102                }
1103                if (!p)
1104                        return 0;
1105                if (fputs(newline, fp) < 0)
1106                        return -1;
1107                count -= p + 1 - buf;
1108                buf = p + 1;
1109                print = 1;
1110        }
1111        return 0;
1112}
1113
1114/*
1115 * '--color-words' algorithm can be described as:
1116 *
1117 *   1. collect the minus/plus lines of a diff hunk, divided into
1118 *      minus-lines and plus-lines;
1119 *
1120 *   2. break both minus-lines and plus-lines into words and
1121 *      place them into two mmfile_t with one word for each line;
1122 *
1123 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1124 *
1125 * And for the common parts of the both file, we output the plus side text.
1126 * diff_words->current_plus is used to trace the current position of the plus file
1127 * which printed. diff_words->last_minus is used to trace the last minus word
1128 * printed.
1129 *
1130 * For '--graph' to work with '--color-words', we need to output the graph prefix
1131 * on each line of color words output. Generally, there are two conditions on
1132 * which we should output the prefix.
1133 *
1134 *   1. diff_words->last_minus == 0 &&
1135 *      diff_words->current_plus == diff_words->plus.text.ptr
1136 *
1137 *      that is: the plus text must start as a new line, and if there is no minus
1138 *      word printed, a graph prefix must be printed.
1139 *
1140 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1141 *      *(diff_words->current_plus - 1) == '\n'
1142 *
1143 *      that is: a graph prefix must be printed following a '\n'
1144 */
1145static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1146{
1147        if ((diff_words->last_minus == 0 &&
1148                diff_words->current_plus == diff_words->plus.text.ptr) ||
1149                (diff_words->current_plus > diff_words->plus.text.ptr &&
1150                *(diff_words->current_plus - 1) == '\n')) {
1151                return 1;
1152        } else {
1153                return 0;
1154        }
1155}
1156
1157static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1158{
1159        struct diff_words_data *diff_words = priv;
1160        struct diff_words_style *style = diff_words->style;
1161        int minus_first, minus_len, plus_first, plus_len;
1162        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1163        struct diff_options *opt = diff_words->opt;
1164        const char *line_prefix;
1165
1166        if (line[0] != '@' || parse_hunk_header(line, len,
1167                        &minus_first, &minus_len, &plus_first, &plus_len))
1168                return;
1169
1170        assert(opt);
1171        line_prefix = diff_line_prefix(opt);
1172
1173        /* POSIX requires that first be decremented by one if len == 0... */
1174        if (minus_len) {
1175                minus_begin = diff_words->minus.orig[minus_first].begin;
1176                minus_end =
1177                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1178        } else
1179                minus_begin = minus_end =
1180                        diff_words->minus.orig[minus_first].end;
1181
1182        if (plus_len) {
1183                plus_begin = diff_words->plus.orig[plus_first].begin;
1184                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1185        } else
1186                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1187
1188        if (color_words_output_graph_prefix(diff_words)) {
1189                fputs(line_prefix, diff_words->opt->file);
1190        }
1191        if (diff_words->current_plus != plus_begin) {
1192                fn_out_diff_words_write_helper(diff_words->opt->file,
1193                                &style->ctx, style->newline,
1194                                plus_begin - diff_words->current_plus,
1195                                diff_words->current_plus, line_prefix);
1196                if (*(plus_begin - 1) == '\n')
1197                        fputs(line_prefix, diff_words->opt->file);
1198        }
1199        if (minus_begin != minus_end) {
1200                fn_out_diff_words_write_helper(diff_words->opt->file,
1201                                &style->old, style->newline,
1202                                minus_end - minus_begin, minus_begin,
1203                                line_prefix);
1204        }
1205        if (plus_begin != plus_end) {
1206                fn_out_diff_words_write_helper(diff_words->opt->file,
1207                                &style->new, style->newline,
1208                                plus_end - plus_begin, plus_begin,
1209                                line_prefix);
1210        }
1211
1212        diff_words->current_plus = plus_end;
1213        diff_words->last_minus = minus_first;
1214}
1215
1216/* This function starts looking at *begin, and returns 0 iff a word was found. */
1217static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1218                int *begin, int *end)
1219{
1220        if (word_regex && *begin < buffer->size) {
1221                regmatch_t match[1];
1222                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1223                                 buffer->size - *begin, 1, match, 0)) {
1224                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1225                                        '\n', match[0].rm_eo - match[0].rm_so);
1226                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1227                        *begin += match[0].rm_so;
1228                        return *begin >= *end;
1229                }
1230                return -1;
1231        }
1232
1233        /* find the next word */
1234        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1235                (*begin)++;
1236        if (*begin >= buffer->size)
1237                return -1;
1238
1239        /* find the end of the word */
1240        *end = *begin + 1;
1241        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1242                (*end)++;
1243
1244        return 0;
1245}
1246
1247/*
1248 * This function splits the words in buffer->text, stores the list with
1249 * newline separator into out, and saves the offsets of the original words
1250 * in buffer->orig.
1251 */
1252static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1253                regex_t *word_regex)
1254{
1255        int i, j;
1256        long alloc = 0;
1257
1258        out->size = 0;
1259        out->ptr = NULL;
1260
1261        /* fake an empty "0th" word */
1262        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1263        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1264        buffer->orig_nr = 1;
1265
1266        for (i = 0; i < buffer->text.size; i++) {
1267                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1268                        return;
1269
1270                /* store original boundaries */
1271                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1272                                buffer->orig_alloc);
1273                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1274                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1275                buffer->orig_nr++;
1276
1277                /* store one word */
1278                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1279                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1280                out->ptr[out->size + j - i] = '\n';
1281                out->size += j - i + 1;
1282
1283                i = j - 1;
1284        }
1285}
1286
1287/* this executes the word diff on the accumulated buffers */
1288static void diff_words_show(struct diff_words_data *diff_words)
1289{
1290        xpparam_t xpp;
1291        xdemitconf_t xecfg;
1292        mmfile_t minus, plus;
1293        struct diff_words_style *style = diff_words->style;
1294
1295        struct diff_options *opt = diff_words->opt;
1296        const char *line_prefix;
1297
1298        assert(opt);
1299        line_prefix = diff_line_prefix(opt);
1300
1301        /* special case: only removal */
1302        if (!diff_words->plus.text.size) {
1303                fputs(line_prefix, diff_words->opt->file);
1304                fn_out_diff_words_write_helper(diff_words->opt->file,
1305                        &style->old, style->newline,
1306                        diff_words->minus.text.size,
1307                        diff_words->minus.text.ptr, line_prefix);
1308                diff_words->minus.text.size = 0;
1309                return;
1310        }
1311
1312        diff_words->current_plus = diff_words->plus.text.ptr;
1313        diff_words->last_minus = 0;
1314
1315        memset(&xpp, 0, sizeof(xpp));
1316        memset(&xecfg, 0, sizeof(xecfg));
1317        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1318        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1319        xpp.flags = 0;
1320        /* as only the hunk header will be parsed, we need a 0-context */
1321        xecfg.ctxlen = 0;
1322        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1323                          &xpp, &xecfg))
1324                die("unable to generate word diff");
1325        free(minus.ptr);
1326        free(plus.ptr);
1327        if (diff_words->current_plus != diff_words->plus.text.ptr +
1328                        diff_words->plus.text.size) {
1329                if (color_words_output_graph_prefix(diff_words))
1330                        fputs(line_prefix, diff_words->opt->file);
1331                fn_out_diff_words_write_helper(diff_words->opt->file,
1332                        &style->ctx, style->newline,
1333                        diff_words->plus.text.ptr + diff_words->plus.text.size
1334                        - diff_words->current_plus, diff_words->current_plus,
1335                        line_prefix);
1336        }
1337        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1338}
1339
1340/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1341static void diff_words_flush(struct emit_callback *ecbdata)
1342{
1343        if (ecbdata->diff_words->minus.text.size ||
1344            ecbdata->diff_words->plus.text.size)
1345                diff_words_show(ecbdata->diff_words);
1346}
1347
1348static void diff_filespec_load_driver(struct diff_filespec *one)
1349{
1350        /* Use already-loaded driver */
1351        if (one->driver)
1352                return;
1353
1354        if (S_ISREG(one->mode))
1355                one->driver = userdiff_find_by_path(one->path);
1356
1357        /* Fallback to default settings */
1358        if (!one->driver)
1359                one->driver = userdiff_find_by_name("default");
1360}
1361
1362static const char *userdiff_word_regex(struct diff_filespec *one)
1363{
1364        diff_filespec_load_driver(one);
1365        return one->driver->word_regex;
1366}
1367
1368static void init_diff_words_data(struct emit_callback *ecbdata,
1369                                 struct diff_options *orig_opts,
1370                                 struct diff_filespec *one,
1371                                 struct diff_filespec *two)
1372{
1373        int i;
1374        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1375        memcpy(o, orig_opts, sizeof(struct diff_options));
1376
1377        ecbdata->diff_words =
1378                xcalloc(1, sizeof(struct diff_words_data));
1379        ecbdata->diff_words->type = o->word_diff;
1380        ecbdata->diff_words->opt = o;
1381        if (!o->word_regex)
1382                o->word_regex = userdiff_word_regex(one);
1383        if (!o->word_regex)
1384                o->word_regex = userdiff_word_regex(two);
1385        if (!o->word_regex)
1386                o->word_regex = diff_word_regex_cfg;
1387        if (o->word_regex) {
1388                ecbdata->diff_words->word_regex = (regex_t *)
1389                        xmalloc(sizeof(regex_t));
1390                if (regcomp(ecbdata->diff_words->word_regex,
1391                            o->word_regex,
1392                            REG_EXTENDED | REG_NEWLINE))
1393                        die ("Invalid regular expression: %s",
1394                             o->word_regex);
1395        }
1396        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1397                if (o->word_diff == diff_words_styles[i].type) {
1398                        ecbdata->diff_words->style =
1399                                &diff_words_styles[i];
1400                        break;
1401                }
1402        }
1403        if (want_color(o->use_color)) {
1404                struct diff_words_style *st = ecbdata->diff_words->style;
1405                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1406                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1407                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
1408        }
1409}
1410
1411static void free_diff_words_data(struct emit_callback *ecbdata)
1412{
1413        if (ecbdata->diff_words) {
1414                diff_words_flush(ecbdata);
1415                free (ecbdata->diff_words->opt);
1416                free (ecbdata->diff_words->minus.text.ptr);
1417                free (ecbdata->diff_words->minus.orig);
1418                free (ecbdata->diff_words->plus.text.ptr);
1419                free (ecbdata->diff_words->plus.orig);
1420                if (ecbdata->diff_words->word_regex) {
1421                        regfree(ecbdata->diff_words->word_regex);
1422                        free(ecbdata->diff_words->word_regex);
1423                }
1424                FREE_AND_NULL(ecbdata->diff_words);
1425        }
1426}
1427
1428const char *diff_get_color(int diff_use_color, enum color_diff ix)
1429{
1430        if (want_color(diff_use_color))
1431                return diff_colors[ix];
1432        return "";
1433}
1434
1435const char *diff_line_prefix(struct diff_options *opt)
1436{
1437        struct strbuf *msgbuf;
1438        if (!opt->output_prefix)
1439                return "";
1440
1441        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1442        return msgbuf->buf;
1443}
1444
1445static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1446{
1447        const char *cp;
1448        unsigned long allot;
1449        size_t l = len;
1450
1451        if (ecb->truncate)
1452                return ecb->truncate(line, len);
1453        cp = line;
1454        allot = l;
1455        while (0 < l) {
1456                (void) utf8_width(&cp, &l);
1457                if (!cp)
1458                        break; /* truncated in the middle? */
1459        }
1460        return allot - l;
1461}
1462
1463static void find_lno(const char *line, struct emit_callback *ecbdata)
1464{
1465        const char *p;
1466        ecbdata->lno_in_preimage = 0;
1467        ecbdata->lno_in_postimage = 0;
1468        p = strchr(line, '-');
1469        if (!p)
1470                return; /* cannot happen */
1471        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1472        p = strchr(p, '+');
1473        if (!p)
1474                return; /* cannot happen */
1475        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1476}
1477
1478static void fn_out_consume(void *priv, char *line, unsigned long len)
1479{
1480        struct emit_callback *ecbdata = priv;
1481        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1482        struct diff_options *o = ecbdata->opt;
1483
1484        o->found_changes = 1;
1485
1486        if (ecbdata->header) {
1487                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
1488                                 ecbdata->header->buf, ecbdata->header->len, 0);
1489                strbuf_reset(ecbdata->header);
1490                ecbdata->header = NULL;
1491        }
1492
1493        if (ecbdata->label_path[0]) {
1494                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1495                                 ecbdata->label_path[0],
1496                                 strlen(ecbdata->label_path[0]), 0);
1497                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1498                                 ecbdata->label_path[1],
1499                                 strlen(ecbdata->label_path[1]), 0);
1500                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1501        }
1502
1503        if (diff_suppress_blank_empty
1504            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1505                line[0] = '\n';
1506                len = 1;
1507        }
1508
1509        if (line[0] == '@') {
1510                if (ecbdata->diff_words)
1511                        diff_words_flush(ecbdata);
1512                len = sane_truncate_line(ecbdata, line, len);
1513                find_lno(line, ecbdata);
1514                emit_hunk_header(ecbdata, line, len);
1515                return;
1516        }
1517
1518        if (ecbdata->diff_words) {
1519                enum diff_symbol s =
1520                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
1521                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
1522                if (line[0] == '-') {
1523                        diff_words_append(line, len,
1524                                          &ecbdata->diff_words->minus);
1525                        return;
1526                } else if (line[0] == '+') {
1527                        diff_words_append(line, len,
1528                                          &ecbdata->diff_words->plus);
1529                        return;
1530                } else if (starts_with(line, "\\ ")) {
1531                        /*
1532                         * Eat the "no newline at eof" marker as if we
1533                         * saw a "+" or "-" line with nothing on it,
1534                         * and return without diff_words_flush() to
1535                         * defer processing. If this is the end of
1536                         * preimage, more "+" lines may come after it.
1537                         */
1538                        return;
1539                }
1540                diff_words_flush(ecbdata);
1541                emit_diff_symbol(o, s, line, len, 0);
1542                return;
1543        }
1544
1545        switch (line[0]) {
1546        case '+':
1547                ecbdata->lno_in_postimage++;
1548                emit_add_line(reset, ecbdata, line + 1, len - 1);
1549                break;
1550        case '-':
1551                ecbdata->lno_in_preimage++;
1552                emit_del_line(reset, ecbdata, line + 1, len - 1);
1553                break;
1554        case ' ':
1555                ecbdata->lno_in_postimage++;
1556                ecbdata->lno_in_preimage++;
1557                emit_context_line(reset, ecbdata, line + 1, len - 1);
1558                break;
1559        default:
1560                /* incomplete line at the end */
1561                ecbdata->lno_in_preimage++;
1562                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
1563                                 line, len, 0);
1564                break;
1565        }
1566}
1567
1568static char *pprint_rename(const char *a, const char *b)
1569{
1570        const char *old = a;
1571        const char *new = b;
1572        struct strbuf name = STRBUF_INIT;
1573        int pfx_length, sfx_length;
1574        int pfx_adjust_for_slash;
1575        int len_a = strlen(a);
1576        int len_b = strlen(b);
1577        int a_midlen, b_midlen;
1578        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1579        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1580
1581        if (qlen_a || qlen_b) {
1582                quote_c_style(a, &name, NULL, 0);
1583                strbuf_addstr(&name, " => ");
1584                quote_c_style(b, &name, NULL, 0);
1585                return strbuf_detach(&name, NULL);
1586        }
1587
1588        /* Find common prefix */
1589        pfx_length = 0;
1590        while (*old && *new && *old == *new) {
1591                if (*old == '/')
1592                        pfx_length = old - a + 1;
1593                old++;
1594                new++;
1595        }
1596
1597        /* Find common suffix */
1598        old = a + len_a;
1599        new = b + len_b;
1600        sfx_length = 0;
1601        /*
1602         * If there is a common prefix, it must end in a slash.  In
1603         * that case we let this loop run 1 into the prefix to see the
1604         * same slash.
1605         *
1606         * If there is no common prefix, we cannot do this as it would
1607         * underrun the input strings.
1608         */
1609        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
1610        while (a + pfx_length - pfx_adjust_for_slash <= old &&
1611               b + pfx_length - pfx_adjust_for_slash <= new &&
1612               *old == *new) {
1613                if (*old == '/')
1614                        sfx_length = len_a - (old - a);
1615                old--;
1616                new--;
1617        }
1618
1619        /*
1620         * pfx{mid-a => mid-b}sfx
1621         * {pfx-a => pfx-b}sfx
1622         * pfx{sfx-a => sfx-b}
1623         * name-a => name-b
1624         */
1625        a_midlen = len_a - pfx_length - sfx_length;
1626        b_midlen = len_b - pfx_length - sfx_length;
1627        if (a_midlen < 0)
1628                a_midlen = 0;
1629        if (b_midlen < 0)
1630                b_midlen = 0;
1631
1632        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1633        if (pfx_length + sfx_length) {
1634                strbuf_add(&name, a, pfx_length);
1635                strbuf_addch(&name, '{');
1636        }
1637        strbuf_add(&name, a + pfx_length, a_midlen);
1638        strbuf_addstr(&name, " => ");
1639        strbuf_add(&name, b + pfx_length, b_midlen);
1640        if (pfx_length + sfx_length) {
1641                strbuf_addch(&name, '}');
1642                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1643        }
1644        return strbuf_detach(&name, NULL);
1645}
1646
1647struct diffstat_t {
1648        int nr;
1649        int alloc;
1650        struct diffstat_file {
1651                char *from_name;
1652                char *name;
1653                char *print_name;
1654                unsigned is_unmerged:1;
1655                unsigned is_binary:1;
1656                unsigned is_renamed:1;
1657                unsigned is_interesting:1;
1658                uintmax_t added, deleted;
1659        } **files;
1660};
1661
1662static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1663                                          const char *name_a,
1664                                          const char *name_b)
1665{
1666        struct diffstat_file *x;
1667        x = xcalloc(1, sizeof(*x));
1668        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
1669        diffstat->files[diffstat->nr++] = x;
1670        if (name_b) {
1671                x->from_name = xstrdup(name_a);
1672                x->name = xstrdup(name_b);
1673                x->is_renamed = 1;
1674        }
1675        else {
1676                x->from_name = NULL;
1677                x->name = xstrdup(name_a);
1678        }
1679        return x;
1680}
1681
1682static void diffstat_consume(void *priv, char *line, unsigned long len)
1683{
1684        struct diffstat_t *diffstat = priv;
1685        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1686
1687        if (line[0] == '+')
1688                x->added++;
1689        else if (line[0] == '-')
1690                x->deleted++;
1691}
1692
1693const char mime_boundary_leader[] = "------------";
1694
1695static int scale_linear(int it, int width, int max_change)
1696{
1697        if (!it)
1698                return 0;
1699        /*
1700         * make sure that at least one '-' or '+' is printed if
1701         * there is any change to this path. The easiest way is to
1702         * scale linearly as if the alloted width is one column shorter
1703         * than it is, and then add 1 to the result.
1704         */
1705        return 1 + (it * (width - 1) / max_change);
1706}
1707
1708static void show_name(FILE *file,
1709                      const char *prefix, const char *name, int len)
1710{
1711        fprintf(file, " %s%-*s |", prefix, len, name);
1712}
1713
1714static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1715{
1716        if (cnt <= 0)
1717                return;
1718        fprintf(file, "%s", set);
1719        while (cnt--)
1720                putc(ch, file);
1721        fprintf(file, "%s", reset);
1722}
1723
1724static void fill_print_name(struct diffstat_file *file)
1725{
1726        char *pname;
1727
1728        if (file->print_name)
1729                return;
1730
1731        if (!file->is_renamed) {
1732                struct strbuf buf = STRBUF_INIT;
1733                if (quote_c_style(file->name, &buf, NULL, 0)) {
1734                        pname = strbuf_detach(&buf, NULL);
1735                } else {
1736                        pname = file->name;
1737                        strbuf_release(&buf);
1738                }
1739        } else {
1740                pname = pprint_rename(file->from_name, file->name);
1741        }
1742        file->print_name = pname;
1743}
1744
1745int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1746{
1747        struct strbuf sb = STRBUF_INIT;
1748        int ret;
1749
1750        if (!files) {
1751                assert(insertions == 0 && deletions == 0);
1752                return fprintf(fp, "%s\n", " 0 files changed");
1753        }
1754
1755        strbuf_addf(&sb,
1756                    (files == 1) ? " %d file changed" : " %d files changed",
1757                    files);
1758
1759        /*
1760         * For binary diff, the caller may want to print "x files
1761         * changed" with insertions == 0 && deletions == 0.
1762         *
1763         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1764         * is probably less confusing (i.e skip over "2 files changed
1765         * but nothing about added/removed lines? Is this a bug in Git?").
1766         */
1767        if (insertions || deletions == 0) {
1768                strbuf_addf(&sb,
1769                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
1770                            insertions);
1771        }
1772
1773        if (deletions || insertions == 0) {
1774                strbuf_addf(&sb,
1775                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
1776                            deletions);
1777        }
1778        strbuf_addch(&sb, '\n');
1779        ret = fputs(sb.buf, fp);
1780        strbuf_release(&sb);
1781        return ret;
1782}
1783
1784static void show_stats(struct diffstat_t *data, struct diff_options *options)
1785{
1786        int i, len, add, del, adds = 0, dels = 0;
1787        uintmax_t max_change = 0, max_len = 0;
1788        int total_files = data->nr, count;
1789        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1790        const char *reset, *add_c, *del_c;
1791        const char *line_prefix = "";
1792        int extra_shown = 0;
1793
1794        if (data->nr == 0)
1795                return;
1796
1797        line_prefix = diff_line_prefix(options);
1798        count = options->stat_count ? options->stat_count : data->nr;
1799
1800        reset = diff_get_color_opt(options, DIFF_RESET);
1801        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1802        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1803
1804        /*
1805         * Find the longest filename and max number of changes
1806         */
1807        for (i = 0; (i < count) && (i < data->nr); i++) {
1808                struct diffstat_file *file = data->files[i];
1809                uintmax_t change = file->added + file->deleted;
1810
1811                if (!file->is_interesting && (change == 0)) {
1812                        count++; /* not shown == room for one more */
1813                        continue;
1814                }
1815                fill_print_name(file);
1816                len = strlen(file->print_name);
1817                if (max_len < len)
1818                        max_len = len;
1819
1820                if (file->is_unmerged) {
1821                        /* "Unmerged" is 8 characters */
1822                        bin_width = bin_width < 8 ? 8 : bin_width;
1823                        continue;
1824                }
1825                if (file->is_binary) {
1826                        /* "Bin XXX -> YYY bytes" */
1827                        int w = 14 + decimal_width(file->added)
1828                                + decimal_width(file->deleted);
1829                        bin_width = bin_width < w ? w : bin_width;
1830                        /* Display change counts aligned with "Bin" */
1831                        number_width = 3;
1832                        continue;
1833                }
1834
1835                if (max_change < change)
1836                        max_change = change;
1837        }
1838        count = i; /* where we can stop scanning in data->files[] */
1839
1840        /*
1841         * We have width = stat_width or term_columns() columns total.
1842         * We want a maximum of min(max_len, stat_name_width) for the name part.
1843         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1844         * We also need 1 for " " and 4 + decimal_width(max_change)
1845         * for " | NNNN " and one the empty column at the end, altogether
1846         * 6 + decimal_width(max_change).
1847         *
1848         * If there's not enough space, we will use the smaller of
1849         * stat_name_width (if set) and 5/8*width for the filename,
1850         * and the rest for constant elements + graph part, but no more
1851         * than stat_graph_width for the graph part.
1852         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1853         * for the standard terminal size).
1854         *
1855         * In other words: stat_width limits the maximum width, and
1856         * stat_name_width fixes the maximum width of the filename,
1857         * and is also used to divide available columns if there
1858         * aren't enough.
1859         *
1860         * Binary files are displayed with "Bin XXX -> YYY bytes"
1861         * instead of the change count and graph. This part is treated
1862         * similarly to the graph part, except that it is not
1863         * "scaled". If total width is too small to accommodate the
1864         * guaranteed minimum width of the filename part and the
1865         * separators and this message, this message will "overflow"
1866         * making the line longer than the maximum width.
1867         */
1868
1869        if (options->stat_width == -1)
1870                width = term_columns() - strlen(line_prefix);
1871        else
1872                width = options->stat_width ? options->stat_width : 80;
1873        number_width = decimal_width(max_change) > number_width ?
1874                decimal_width(max_change) : number_width;
1875
1876        if (options->stat_graph_width == -1)
1877                options->stat_graph_width = diff_stat_graph_width;
1878
1879        /*
1880         * Guarantee 3/8*16==6 for the graph part
1881         * and 5/8*16==10 for the filename part
1882         */
1883        if (width < 16 + 6 + number_width)
1884                width = 16 + 6 + number_width;
1885
1886        /*
1887         * First assign sizes that are wanted, ignoring available width.
1888         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1889         * starting from "XXX" should fit in graph_width.
1890         */
1891        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1892        if (options->stat_graph_width &&
1893            options->stat_graph_width < graph_width)
1894                graph_width = options->stat_graph_width;
1895
1896        name_width = (options->stat_name_width > 0 &&
1897                      options->stat_name_width < max_len) ?
1898                options->stat_name_width : max_len;
1899
1900        /*
1901         * Adjust adjustable widths not to exceed maximum width
1902         */
1903        if (name_width + number_width + 6 + graph_width > width) {
1904                if (graph_width > width * 3/8 - number_width - 6) {
1905                        graph_width = width * 3/8 - number_width - 6;
1906                        if (graph_width < 6)
1907                                graph_width = 6;
1908                }
1909
1910                if (options->stat_graph_width &&
1911                    graph_width > options->stat_graph_width)
1912                        graph_width = options->stat_graph_width;
1913                if (name_width > width - number_width - 6 - graph_width)
1914                        name_width = width - number_width - 6 - graph_width;
1915                else
1916                        graph_width = width - number_width - 6 - name_width;
1917        }
1918
1919        /*
1920         * From here name_width is the width of the name area,
1921         * and graph_width is the width of the graph area.
1922         * max_change is used to scale graph properly.
1923         */
1924        for (i = 0; i < count; i++) {
1925                const char *prefix = "";
1926                struct diffstat_file *file = data->files[i];
1927                char *name = file->print_name;
1928                uintmax_t added = file->added;
1929                uintmax_t deleted = file->deleted;
1930                int name_len;
1931
1932                if (!file->is_interesting && (added + deleted == 0))
1933                        continue;
1934
1935                /*
1936                 * "scale" the filename
1937                 */
1938                len = name_width;
1939                name_len = strlen(name);
1940                if (name_width < name_len) {
1941                        char *slash;
1942                        prefix = "...";
1943                        len -= 3;
1944                        name += name_len - len;
1945                        slash = strchr(name, '/');
1946                        if (slash)
1947                                name = slash;
1948                }
1949
1950                if (file->is_binary) {
1951                        fprintf(options->file, "%s", line_prefix);
1952                        show_name(options->file, prefix, name, len);
1953                        fprintf(options->file, " %*s", number_width, "Bin");
1954                        if (!added && !deleted) {
1955                                putc('\n', options->file);
1956                                continue;
1957                        }
1958                        fprintf(options->file, " %s%"PRIuMAX"%s",
1959                                del_c, deleted, reset);
1960                        fprintf(options->file, " -> ");
1961                        fprintf(options->file, "%s%"PRIuMAX"%s",
1962                                add_c, added, reset);
1963                        fprintf(options->file, " bytes");
1964                        fprintf(options->file, "\n");
1965                        continue;
1966                }
1967                else if (file->is_unmerged) {
1968                        fprintf(options->file, "%s", line_prefix);
1969                        show_name(options->file, prefix, name, len);
1970                        fprintf(options->file, " Unmerged\n");
1971                        continue;
1972                }
1973
1974                /*
1975                 * scale the add/delete
1976                 */
1977                add = added;
1978                del = deleted;
1979
1980                if (graph_width <= max_change) {
1981                        int total = scale_linear(add + del, graph_width, max_change);
1982                        if (total < 2 && add && del)
1983                                /* width >= 2 due to the sanity check */
1984                                total = 2;
1985                        if (add < del) {
1986                                add = scale_linear(add, graph_width, max_change);
1987                                del = total - add;
1988                        } else {
1989                                del = scale_linear(del, graph_width, max_change);
1990                                add = total - del;
1991                        }
1992                }
1993                fprintf(options->file, "%s", line_prefix);
1994                show_name(options->file, prefix, name, len);
1995                fprintf(options->file, " %*"PRIuMAX"%s",
1996                        number_width, added + deleted,
1997                        added + deleted ? " " : "");
1998                show_graph(options->file, '+', add, add_c, reset);
1999                show_graph(options->file, '-', del, del_c, reset);
2000                fprintf(options->file, "\n");
2001        }
2002
2003        for (i = 0; i < data->nr; i++) {
2004                struct diffstat_file *file = data->files[i];
2005                uintmax_t added = file->added;
2006                uintmax_t deleted = file->deleted;
2007
2008                if (file->is_unmerged ||
2009                    (!file->is_interesting && (added + deleted == 0))) {
2010                        total_files--;
2011                        continue;
2012                }
2013
2014                if (!file->is_binary) {
2015                        adds += added;
2016                        dels += deleted;
2017                }
2018                if (i < count)
2019                        continue;
2020                if (!extra_shown)
2021                        fprintf(options->file, "%s ...\n", line_prefix);
2022                extra_shown = 1;
2023        }
2024        fprintf(options->file, "%s", line_prefix);
2025        print_stat_summary(options->file, total_files, adds, dels);
2026}
2027
2028static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2029{
2030        int i, adds = 0, dels = 0, total_files = data->nr;
2031
2032        if (data->nr == 0)
2033                return;
2034
2035        for (i = 0; i < data->nr; i++) {
2036                int added = data->files[i]->added;
2037                int deleted= data->files[i]->deleted;
2038
2039                if (data->files[i]->is_unmerged ||
2040                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2041                        total_files--;
2042                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2043                        adds += added;
2044                        dels += deleted;
2045                }
2046        }
2047        fprintf(options->file, "%s", diff_line_prefix(options));
2048        print_stat_summary(options->file, total_files, adds, dels);
2049}
2050
2051static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2052{
2053        int i;
2054
2055        if (data->nr == 0)
2056                return;
2057
2058        for (i = 0; i < data->nr; i++) {
2059                struct diffstat_file *file = data->files[i];
2060
2061                fprintf(options->file, "%s", diff_line_prefix(options));
2062
2063                if (file->is_binary)
2064                        fprintf(options->file, "-\t-\t");
2065                else
2066                        fprintf(options->file,
2067                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2068                                file->added, file->deleted);
2069                if (options->line_termination) {
2070                        fill_print_name(file);
2071                        if (!file->is_renamed)
2072                                write_name_quoted(file->name, options->file,
2073                                                  options->line_termination);
2074                        else {
2075                                fputs(file->print_name, options->file);
2076                                putc(options->line_termination, options->file);
2077                        }
2078                } else {
2079                        if (file->is_renamed) {
2080                                putc('\0', options->file);
2081                                write_name_quoted(file->from_name, options->file, '\0');
2082                        }
2083                        write_name_quoted(file->name, options->file, '\0');
2084                }
2085        }
2086}
2087
2088struct dirstat_file {
2089        const char *name;
2090        unsigned long changed;
2091};
2092
2093struct dirstat_dir {
2094        struct dirstat_file *files;
2095        int alloc, nr, permille, cumulative;
2096};
2097
2098static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2099                unsigned long changed, const char *base, int baselen)
2100{
2101        unsigned long this_dir = 0;
2102        unsigned int sources = 0;
2103        const char *line_prefix = diff_line_prefix(opt);
2104
2105        while (dir->nr) {
2106                struct dirstat_file *f = dir->files;
2107                int namelen = strlen(f->name);
2108                unsigned long this;
2109                char *slash;
2110
2111                if (namelen < baselen)
2112                        break;
2113                if (memcmp(f->name, base, baselen))
2114                        break;
2115                slash = strchr(f->name + baselen, '/');
2116                if (slash) {
2117                        int newbaselen = slash + 1 - f->name;
2118                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2119                        sources++;
2120                } else {
2121                        this = f->changed;
2122                        dir->files++;
2123                        dir->nr--;
2124                        sources += 2;
2125                }
2126                this_dir += this;
2127        }
2128
2129        /*
2130         * We don't report dirstat's for
2131         *  - the top level
2132         *  - or cases where everything came from a single directory
2133         *    under this directory (sources == 1).
2134         */
2135        if (baselen && sources != 1) {
2136                if (this_dir) {
2137                        int permille = this_dir * 1000 / changed;
2138                        if (permille >= dir->permille) {
2139                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2140                                        permille / 10, permille % 10, baselen, base);
2141                                if (!dir->cumulative)
2142                                        return 0;
2143                        }
2144                }
2145        }
2146        return this_dir;
2147}
2148
2149static int dirstat_compare(const void *_a, const void *_b)
2150{
2151        const struct dirstat_file *a = _a;
2152        const struct dirstat_file *b = _b;
2153        return strcmp(a->name, b->name);
2154}
2155
2156static void show_dirstat(struct diff_options *options)
2157{
2158        int i;
2159        unsigned long changed;
2160        struct dirstat_dir dir;
2161        struct diff_queue_struct *q = &diff_queued_diff;
2162
2163        dir.files = NULL;
2164        dir.alloc = 0;
2165        dir.nr = 0;
2166        dir.permille = options->dirstat_permille;
2167        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2168
2169        changed = 0;
2170        for (i = 0; i < q->nr; i++) {
2171                struct diff_filepair *p = q->queue[i];
2172                const char *name;
2173                unsigned long copied, added, damage;
2174                int content_changed;
2175
2176                name = p->two->path ? p->two->path : p->one->path;
2177
2178                if (p->one->oid_valid && p->two->oid_valid)
2179                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
2180                else
2181                        content_changed = 1;
2182
2183                if (!content_changed) {
2184                        /*
2185                         * The SHA1 has not changed, so pre-/post-content is
2186                         * identical. We can therefore skip looking at the
2187                         * file contents altogether.
2188                         */
2189                        damage = 0;
2190                        goto found_damage;
2191                }
2192
2193                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
2194                        /*
2195                         * In --dirstat-by-file mode, we don't really need to
2196                         * look at the actual file contents at all.
2197                         * The fact that the SHA1 changed is enough for us to
2198                         * add this file to the list of results
2199                         * (with each file contributing equal damage).
2200                         */
2201                        damage = 1;
2202                        goto found_damage;
2203                }
2204
2205                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2206                        diff_populate_filespec(p->one, 0);
2207                        diff_populate_filespec(p->two, 0);
2208                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2209                                               &copied, &added);
2210                        diff_free_filespec_data(p->one);
2211                        diff_free_filespec_data(p->two);
2212                } else if (DIFF_FILE_VALID(p->one)) {
2213                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2214                        copied = added = 0;
2215                        diff_free_filespec_data(p->one);
2216                } else if (DIFF_FILE_VALID(p->two)) {
2217                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2218                        copied = 0;
2219                        added = p->two->size;
2220                        diff_free_filespec_data(p->two);
2221                } else
2222                        continue;
2223
2224                /*
2225                 * Original minus copied is the removed material,
2226                 * added is the new material.  They are both damages
2227                 * made to the preimage.
2228                 * If the resulting damage is zero, we know that
2229                 * diffcore_count_changes() considers the two entries to
2230                 * be identical, but since content_changed is true, we
2231                 * know that there must have been _some_ kind of change,
2232                 * so we force all entries to have damage > 0.
2233                 */
2234                damage = (p->one->size - copied) + added;
2235                if (!damage)
2236                        damage = 1;
2237
2238found_damage:
2239                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2240                dir.files[dir.nr].name = name;
2241                dir.files[dir.nr].changed = damage;
2242                changed += damage;
2243                dir.nr++;
2244        }
2245
2246        /* This can happen even with many files, if everything was renames */
2247        if (!changed)
2248                return;
2249
2250        /* Show all directories with more than x% of the changes */
2251        QSORT(dir.files, dir.nr, dirstat_compare);
2252        gather_dirstat(options, &dir, changed, "", 0);
2253}
2254
2255static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2256{
2257        int i;
2258        unsigned long changed;
2259        struct dirstat_dir dir;
2260
2261        if (data->nr == 0)
2262                return;
2263
2264        dir.files = NULL;
2265        dir.alloc = 0;
2266        dir.nr = 0;
2267        dir.permille = options->dirstat_permille;
2268        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2269
2270        changed = 0;
2271        for (i = 0; i < data->nr; i++) {
2272                struct diffstat_file *file = data->files[i];
2273                unsigned long damage = file->added + file->deleted;
2274                if (file->is_binary)
2275                        /*
2276                         * binary files counts bytes, not lines. Must find some
2277                         * way to normalize binary bytes vs. textual lines.
2278                         * The following heuristic assumes that there are 64
2279                         * bytes per "line".
2280                         * This is stupid and ugly, but very cheap...
2281                         */
2282                        damage = (damage + 63) / 64;
2283                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2284                dir.files[dir.nr].name = file->name;
2285                dir.files[dir.nr].changed = damage;
2286                changed += damage;
2287                dir.nr++;
2288        }
2289
2290        /* This can happen even with many files, if everything was renames */
2291        if (!changed)
2292                return;
2293
2294        /* Show all directories with more than x% of the changes */
2295        QSORT(dir.files, dir.nr, dirstat_compare);
2296        gather_dirstat(options, &dir, changed, "", 0);
2297}
2298
2299static void free_diffstat_info(struct diffstat_t *diffstat)
2300{
2301        int i;
2302        for (i = 0; i < diffstat->nr; i++) {
2303                struct diffstat_file *f = diffstat->files[i];
2304                if (f->name != f->print_name)
2305                        free(f->print_name);
2306                free(f->name);
2307                free(f->from_name);
2308                free(f);
2309        }
2310        free(diffstat->files);
2311}
2312
2313struct checkdiff_t {
2314        const char *filename;
2315        int lineno;
2316        int conflict_marker_size;
2317        struct diff_options *o;
2318        unsigned ws_rule;
2319        unsigned status;
2320};
2321
2322static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2323{
2324        char firstchar;
2325        int cnt;
2326
2327        if (len < marker_size + 1)
2328                return 0;
2329        firstchar = line[0];
2330        switch (firstchar) {
2331        case '=': case '>': case '<': case '|':
2332                break;
2333        default:
2334                return 0;
2335        }
2336        for (cnt = 1; cnt < marker_size; cnt++)
2337                if (line[cnt] != firstchar)
2338                        return 0;
2339        /* line[1] thru line[marker_size-1] are same as firstchar */
2340        if (len < marker_size + 1 || !isspace(line[marker_size]))
2341                return 0;
2342        return 1;
2343}
2344
2345static void checkdiff_consume(void *priv, char *line, unsigned long len)
2346{
2347        struct checkdiff_t *data = priv;
2348        int marker_size = data->conflict_marker_size;
2349        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2350        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2351        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2352        char *err;
2353        const char *line_prefix;
2354
2355        assert(data->o);
2356        line_prefix = diff_line_prefix(data->o);
2357
2358        if (line[0] == '+') {
2359                unsigned bad;
2360                data->lineno++;
2361                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2362                        data->status |= 1;
2363                        fprintf(data->o->file,
2364                                "%s%s:%d: leftover conflict marker\n",
2365                                line_prefix, data->filename, data->lineno);
2366                }
2367                bad = ws_check(line + 1, len - 1, data->ws_rule);
2368                if (!bad)
2369                        return;
2370                data->status |= bad;
2371                err = whitespace_error_string(bad);
2372                fprintf(data->o->file, "%s%s:%d: %s.\n",
2373                        line_prefix, data->filename, data->lineno, err);
2374                free(err);
2375                emit_line(data->o, set, reset, line, 1);
2376                ws_check_emit(line + 1, len - 1, data->ws_rule,
2377                              data->o->file, set, reset, ws);
2378        } else if (line[0] == ' ') {
2379                data->lineno++;
2380        } else if (line[0] == '@') {
2381                char *plus = strchr(line, '+');
2382                if (plus)
2383                        data->lineno = strtol(plus, NULL, 10) - 1;
2384                else
2385                        die("invalid diff");
2386        }
2387}
2388
2389static unsigned char *deflate_it(char *data,
2390                                 unsigned long size,
2391                                 unsigned long *result_size)
2392{
2393        int bound;
2394        unsigned char *deflated;
2395        git_zstream stream;
2396
2397        git_deflate_init(&stream, zlib_compression_level);
2398        bound = git_deflate_bound(&stream, size);
2399        deflated = xmalloc(bound);
2400        stream.next_out = deflated;
2401        stream.avail_out = bound;
2402
2403        stream.next_in = (unsigned char *)data;
2404        stream.avail_in = size;
2405        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2406                ; /* nothing */
2407        git_deflate_end(&stream);
2408        *result_size = stream.total_out;
2409        return deflated;
2410}
2411
2412static void emit_binary_diff_body(struct diff_options *o,
2413                                  mmfile_t *one, mmfile_t *two)
2414{
2415        void *cp;
2416        void *delta;
2417        void *deflated;
2418        void *data;
2419        unsigned long orig_size;
2420        unsigned long delta_size;
2421        unsigned long deflate_size;
2422        unsigned long data_size;
2423
2424        /* We could do deflated delta, or we could do just deflated two,
2425         * whichever is smaller.
2426         */
2427        delta = NULL;
2428        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2429        if (one->size && two->size) {
2430                delta = diff_delta(one->ptr, one->size,
2431                                   two->ptr, two->size,
2432                                   &delta_size, deflate_size);
2433                if (delta) {
2434                        void *to_free = delta;
2435                        orig_size = delta_size;
2436                        delta = deflate_it(delta, delta_size, &delta_size);
2437                        free(to_free);
2438                }
2439        }
2440
2441        if (delta && delta_size < deflate_size) {
2442                char *s = xstrfmt("%lu", orig_size);
2443                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
2444                                 s, strlen(s), 0);
2445                free(s);
2446                free(deflated);
2447                data = delta;
2448                data_size = delta_size;
2449        } else {
2450                char *s = xstrfmt("%lu", two->size);
2451                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
2452                                 s, strlen(s), 0);
2453                free(s);
2454                free(delta);
2455                data = deflated;
2456                data_size = deflate_size;
2457        }
2458
2459        /* emit data encoded in base85 */
2460        cp = data;
2461        while (data_size) {
2462                int len;
2463                int bytes = (52 < data_size) ? 52 : data_size;
2464                char line[71];
2465                data_size -= bytes;
2466                if (bytes <= 26)
2467                        line[0] = bytes + 'A' - 1;
2468                else
2469                        line[0] = bytes - 26 + 'a' - 1;
2470                encode_85(line + 1, cp, bytes);
2471                cp = (char *) cp + bytes;
2472
2473                len = strlen(line);
2474                line[len++] = '\n';
2475                line[len] = '\0';
2476
2477                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
2478                                 line, len, 0);
2479        }
2480        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
2481        free(data);
2482}
2483
2484static void emit_binary_diff(struct diff_options *o,
2485                             mmfile_t *one, mmfile_t *two)
2486{
2487        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
2488        emit_binary_diff_body(o, one, two);
2489        emit_binary_diff_body(o, two, one);
2490}
2491
2492int diff_filespec_is_binary(struct diff_filespec *one)
2493{
2494        if (one->is_binary == -1) {
2495                diff_filespec_load_driver(one);
2496                if (one->driver->binary != -1)
2497                        one->is_binary = one->driver->binary;
2498                else {
2499                        if (!one->data && DIFF_FILE_VALID(one))
2500                                diff_populate_filespec(one, CHECK_BINARY);
2501                        if (one->is_binary == -1 && one->data)
2502                                one->is_binary = buffer_is_binary(one->data,
2503                                                one->size);
2504                        if (one->is_binary == -1)
2505                                one->is_binary = 0;
2506                }
2507        }
2508        return one->is_binary;
2509}
2510
2511static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2512{
2513        diff_filespec_load_driver(one);
2514        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2515}
2516
2517void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2518{
2519        if (!options->a_prefix)
2520                options->a_prefix = a;
2521        if (!options->b_prefix)
2522                options->b_prefix = b;
2523}
2524
2525struct userdiff_driver *get_textconv(struct diff_filespec *one)
2526{
2527        if (!DIFF_FILE_VALID(one))
2528                return NULL;
2529
2530        diff_filespec_load_driver(one);
2531        return userdiff_get_textconv(one->driver);
2532}
2533
2534static void builtin_diff(const char *name_a,
2535                         const char *name_b,
2536                         struct diff_filespec *one,
2537                         struct diff_filespec *two,
2538                         const char *xfrm_msg,
2539                         int must_show_header,
2540                         struct diff_options *o,
2541                         int complete_rewrite)
2542{
2543        mmfile_t mf1, mf2;
2544        const char *lbl[2];
2545        char *a_one, *b_two;
2546        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
2547        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2548        const char *a_prefix, *b_prefix;
2549        struct userdiff_driver *textconv_one = NULL;
2550        struct userdiff_driver *textconv_two = NULL;
2551        struct strbuf header = STRBUF_INIT;
2552        const char *line_prefix = diff_line_prefix(o);
2553
2554        diff_set_mnemonic_prefix(o, "a/", "b/");
2555        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2556                a_prefix = o->b_prefix;
2557                b_prefix = o->a_prefix;
2558        } else {
2559                a_prefix = o->a_prefix;
2560                b_prefix = o->b_prefix;
2561        }
2562
2563        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
2564            (!one->mode || S_ISGITLINK(one->mode)) &&
2565            (!two->mode || S_ISGITLINK(two->mode))) {
2566                show_submodule_summary(o, one->path ? one->path : two->path,
2567                                &one->oid, &two->oid,
2568                                two->dirty_submodule);
2569                return;
2570        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
2571                   (!one->mode || S_ISGITLINK(one->mode)) &&
2572                   (!two->mode || S_ISGITLINK(two->mode))) {
2573                show_submodule_inline_diff(o, one->path ? one->path : two->path,
2574                                &one->oid, &two->oid,
2575                                two->dirty_submodule);
2576                return;
2577        }
2578
2579        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2580                textconv_one = get_textconv(one);
2581                textconv_two = get_textconv(two);
2582        }
2583
2584        /* Never use a non-valid filename anywhere if at all possible */
2585        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2586        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2587
2588        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2589        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2590        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2591        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2592        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
2593        if (lbl[0][0] == '/') {
2594                /* /dev/null */
2595                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
2596                if (xfrm_msg)
2597                        strbuf_addstr(&header, xfrm_msg);
2598                must_show_header = 1;
2599        }
2600        else if (lbl[1][0] == '/') {
2601                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
2602                if (xfrm_msg)
2603                        strbuf_addstr(&header, xfrm_msg);
2604                must_show_header = 1;
2605        }
2606        else {
2607                if (one->mode != two->mode) {
2608                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
2609                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
2610                        must_show_header = 1;
2611                }
2612                if (xfrm_msg)
2613                        strbuf_addstr(&header, xfrm_msg);
2614
2615                /*
2616                 * we do not run diff between different kind
2617                 * of objects.
2618                 */
2619                if ((one->mode ^ two->mode) & S_IFMT)
2620                        goto free_ab_and_return;
2621                if (complete_rewrite &&
2622                    (textconv_one || !diff_filespec_is_binary(one)) &&
2623                    (textconv_two || !diff_filespec_is_binary(two))) {
2624                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2625                                         header.buf, header.len, 0);
2626                        strbuf_reset(&header);
2627                        emit_rewrite_diff(name_a, name_b, one, two,
2628                                                textconv_one, textconv_two, o);
2629                        o->found_changes = 1;
2630                        goto free_ab_and_return;
2631                }
2632        }
2633
2634        if (o->irreversible_delete && lbl[1][0] == '/') {
2635                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
2636                                 header.len, 0);
2637                strbuf_reset(&header);
2638                goto free_ab_and_return;
2639        } else if (!DIFF_OPT_TST(o, TEXT) &&
2640            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2641              (!textconv_two && diff_filespec_is_binary(two)) )) {
2642                struct strbuf sb = STRBUF_INIT;
2643                if (!one->data && !two->data &&
2644                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
2645                    !DIFF_OPT_TST(o, BINARY)) {
2646                        if (!oidcmp(&one->oid, &two->oid)) {
2647                                if (must_show_header)
2648                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2649                                                         header.buf, header.len,
2650                                                         0);
2651                                goto free_ab_and_return;
2652                        }
2653                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2654                                         header.buf, header.len, 0);
2655                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
2656                                    diff_line_prefix(o), lbl[0], lbl[1]);
2657                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
2658                                         sb.buf, sb.len, 0);
2659                        strbuf_release(&sb);
2660                        goto free_ab_and_return;
2661                }
2662                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2663                        die("unable to read files to diff");
2664                /* Quite common confusing case */
2665                if (mf1.size == mf2.size &&
2666                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2667                        if (must_show_header)
2668                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2669                                                 header.buf, header.len, 0);
2670                        goto free_ab_and_return;
2671                }
2672                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
2673                strbuf_reset(&header);
2674                if (DIFF_OPT_TST(o, BINARY))
2675                        emit_binary_diff(o, &mf1, &mf2);
2676                else {
2677                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
2678                                    diff_line_prefix(o), lbl[0], lbl[1]);
2679                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
2680                                         sb.buf, sb.len, 0);
2681                        strbuf_release(&sb);
2682                }
2683                o->found_changes = 1;
2684        } else {
2685                /* Crazy xdl interfaces.. */
2686                const char *diffopts = getenv("GIT_DIFF_OPTS");
2687                const char *v;
2688                xpparam_t xpp;
2689                xdemitconf_t xecfg;
2690                struct emit_callback ecbdata;
2691                const struct userdiff_funcname *pe;
2692
2693                if (must_show_header) {
2694                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2695                                         header.buf, header.len, 0);
2696                        strbuf_reset(&header);
2697                }
2698
2699                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2700                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2701
2702                pe = diff_funcname_pattern(one);
2703                if (!pe)
2704                        pe = diff_funcname_pattern(two);
2705
2706                memset(&xpp, 0, sizeof(xpp));
2707                memset(&xecfg, 0, sizeof(xecfg));
2708                memset(&ecbdata, 0, sizeof(ecbdata));
2709                ecbdata.label_path = lbl;
2710                ecbdata.color_diff = want_color(o->use_color);
2711                ecbdata.ws_rule = whitespace_rule(name_b);
2712                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2713                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2714                ecbdata.opt = o;
2715                ecbdata.header = header.len ? &header : NULL;
2716                xpp.flags = o->xdl_opts;
2717                xecfg.ctxlen = o->context;
2718                xecfg.interhunkctxlen = o->interhunkcontext;
2719                xecfg.flags = XDL_EMIT_FUNCNAMES;
2720                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2721                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2722                if (pe)
2723                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2724                if (!diffopts)
2725                        ;
2726                else if (skip_prefix(diffopts, "--unified=", &v))
2727                        xecfg.ctxlen = strtoul(v, NULL, 10);
2728                else if (skip_prefix(diffopts, "-u", &v))
2729                        xecfg.ctxlen = strtoul(v, NULL, 10);
2730                if (o->word_diff)
2731                        init_diff_words_data(&ecbdata, o, one, two);
2732                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2733                                  &xpp, &xecfg))
2734                        die("unable to generate diff for %s", one->path);
2735                if (o->word_diff)
2736                        free_diff_words_data(&ecbdata);
2737                if (textconv_one)
2738                        free(mf1.ptr);
2739                if (textconv_two)
2740                        free(mf2.ptr);
2741                xdiff_clear_find_func(&xecfg);
2742        }
2743
2744 free_ab_and_return:
2745        strbuf_release(&header);
2746        diff_free_filespec_data(one);
2747        diff_free_filespec_data(two);
2748        free(a_one);
2749        free(b_two);
2750        return;
2751}
2752
2753static void builtin_diffstat(const char *name_a, const char *name_b,
2754                             struct diff_filespec *one,
2755                             struct diff_filespec *two,
2756                             struct diffstat_t *diffstat,
2757                             struct diff_options *o,
2758                             struct diff_filepair *p)
2759{
2760        mmfile_t mf1, mf2;
2761        struct diffstat_file *data;
2762        int same_contents;
2763        int complete_rewrite = 0;
2764
2765        if (!DIFF_PAIR_UNMERGED(p)) {
2766                if (p->status == DIFF_STATUS_MODIFIED && p->score)
2767                        complete_rewrite = 1;
2768        }
2769
2770        data = diffstat_add(diffstat, name_a, name_b);
2771        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
2772
2773        if (!one || !two) {
2774                data->is_unmerged = 1;
2775                return;
2776        }
2777
2778        same_contents = !oidcmp(&one->oid, &two->oid);
2779
2780        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2781                data->is_binary = 1;
2782                if (same_contents) {
2783                        data->added = 0;
2784                        data->deleted = 0;
2785                } else {
2786                        data->added = diff_filespec_size(two);
2787                        data->deleted = diff_filespec_size(one);
2788                }
2789        }
2790
2791        else if (complete_rewrite) {
2792                diff_populate_filespec(one, 0);
2793                diff_populate_filespec(two, 0);
2794                data->deleted = count_lines(one->data, one->size);
2795                data->added = count_lines(two->data, two->size);
2796        }
2797
2798        else if (!same_contents) {
2799                /* Crazy xdl interfaces.. */
2800                xpparam_t xpp;
2801                xdemitconf_t xecfg;
2802
2803                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2804                        die("unable to read files to diff");
2805
2806                memset(&xpp, 0, sizeof(xpp));
2807                memset(&xecfg, 0, sizeof(xecfg));
2808                xpp.flags = o->xdl_opts;
2809                xecfg.ctxlen = o->context;
2810                xecfg.interhunkctxlen = o->interhunkcontext;
2811                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2812                                  &xpp, &xecfg))
2813                        die("unable to generate diffstat for %s", one->path);
2814        }
2815
2816        diff_free_filespec_data(one);
2817        diff_free_filespec_data(two);
2818}
2819
2820static void builtin_checkdiff(const char *name_a, const char *name_b,
2821                              const char *attr_path,
2822                              struct diff_filespec *one,
2823                              struct diff_filespec *two,
2824                              struct diff_options *o)
2825{
2826        mmfile_t mf1, mf2;
2827        struct checkdiff_t data;
2828
2829        if (!two)
2830                return;
2831
2832        memset(&data, 0, sizeof(data));
2833        data.filename = name_b ? name_b : name_a;
2834        data.lineno = 0;
2835        data.o = o;
2836        data.ws_rule = whitespace_rule(attr_path);
2837        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2838
2839        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2840                die("unable to read files to diff");
2841
2842        /*
2843         * All the other codepaths check both sides, but not checking
2844         * the "old" side here is deliberate.  We are checking the newly
2845         * introduced changes, and as long as the "new" side is text, we
2846         * can and should check what it introduces.
2847         */
2848        if (diff_filespec_is_binary(two))
2849                goto free_and_return;
2850        else {
2851                /* Crazy xdl interfaces.. */
2852                xpparam_t xpp;
2853                xdemitconf_t xecfg;
2854
2855                memset(&xpp, 0, sizeof(xpp));
2856                memset(&xecfg, 0, sizeof(xecfg));
2857                xecfg.ctxlen = 1; /* at least one context line */
2858                xpp.flags = 0;
2859                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2860                                  &xpp, &xecfg))
2861                        die("unable to generate checkdiff for %s", one->path);
2862
2863                if (data.ws_rule & WS_BLANK_AT_EOF) {
2864                        struct emit_callback ecbdata;
2865                        int blank_at_eof;
2866
2867                        ecbdata.ws_rule = data.ws_rule;
2868                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2869                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2870
2871                        if (blank_at_eof) {
2872                                static char *err;
2873                                if (!err)
2874                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2875                                fprintf(o->file, "%s:%d: %s.\n",
2876                                        data.filename, blank_at_eof, err);
2877                                data.status = 1; /* report errors */
2878                        }
2879                }
2880        }
2881 free_and_return:
2882        diff_free_filespec_data(one);
2883        diff_free_filespec_data(two);
2884        if (data.status)
2885                DIFF_OPT_SET(o, CHECK_FAILED);
2886}
2887
2888struct diff_filespec *alloc_filespec(const char *path)
2889{
2890        struct diff_filespec *spec;
2891
2892        FLEXPTR_ALLOC_STR(spec, path, path);
2893        spec->count = 1;
2894        spec->is_binary = -1;
2895        return spec;
2896}
2897
2898void free_filespec(struct diff_filespec *spec)
2899{
2900        if (!--spec->count) {
2901                diff_free_filespec_data(spec);
2902                free(spec);
2903        }
2904}
2905
2906void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
2907                   int oid_valid, unsigned short mode)
2908{
2909        if (mode) {
2910                spec->mode = canon_mode(mode);
2911                oidcpy(&spec->oid, oid);
2912                spec->oid_valid = oid_valid;
2913        }
2914}
2915
2916/*
2917 * Given a name and sha1 pair, if the index tells us the file in
2918 * the work tree has that object contents, return true, so that
2919 * prepare_temp_file() does not have to inflate and extract.
2920 */
2921static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
2922{
2923        const struct cache_entry *ce;
2924        struct stat st;
2925        int pos, len;
2926
2927        /*
2928         * We do not read the cache ourselves here, because the
2929         * benchmark with my previous version that always reads cache
2930         * shows that it makes things worse for diff-tree comparing
2931         * two linux-2.6 kernel trees in an already checked out work
2932         * tree.  This is because most diff-tree comparisons deal with
2933         * only a small number of files, while reading the cache is
2934         * expensive for a large project, and its cost outweighs the
2935         * savings we get by not inflating the object to a temporary
2936         * file.  Practically, this code only helps when we are used
2937         * by diff-cache --cached, which does read the cache before
2938         * calling us.
2939         */
2940        if (!active_cache)
2941                return 0;
2942
2943        /* We want to avoid the working directory if our caller
2944         * doesn't need the data in a normal file, this system
2945         * is rather slow with its stat/open/mmap/close syscalls,
2946         * and the object is contained in a pack file.  The pack
2947         * is probably already open and will be faster to obtain
2948         * the data through than the working directory.  Loose
2949         * objects however would tend to be slower as they need
2950         * to be individually opened and inflated.
2951         */
2952        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(oid->hash))
2953                return 0;
2954
2955        /*
2956         * Similarly, if we'd have to convert the file contents anyway, that
2957         * makes the optimization not worthwhile.
2958         */
2959        if (!want_file && would_convert_to_git(&the_index, name))
2960                return 0;
2961
2962        len = strlen(name);
2963        pos = cache_name_pos(name, len);
2964        if (pos < 0)
2965                return 0;
2966        ce = active_cache[pos];
2967
2968        /*
2969         * This is not the sha1 we are looking for, or
2970         * unreusable because it is not a regular file.
2971         */
2972        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
2973                return 0;
2974
2975        /*
2976         * If ce is marked as "assume unchanged", there is no
2977         * guarantee that work tree matches what we are looking for.
2978         */
2979        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2980                return 0;
2981
2982        /*
2983         * If ce matches the file in the work tree, we can reuse it.
2984         */
2985        if (ce_uptodate(ce) ||
2986            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2987                return 1;
2988
2989        return 0;
2990}
2991
2992static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2993{
2994        struct strbuf buf = STRBUF_INIT;
2995        char *dirty = "";
2996
2997        /* Are we looking at the work tree? */
2998        if (s->dirty_submodule)
2999                dirty = "-dirty";
3000
3001        strbuf_addf(&buf, "Subproject commit %s%s\n",
3002                    oid_to_hex(&s->oid), dirty);
3003        s->size = buf.len;
3004        if (size_only) {
3005                s->data = NULL;
3006                strbuf_release(&buf);
3007        } else {
3008                s->data = strbuf_detach(&buf, NULL);
3009                s->should_free = 1;
3010        }
3011        return 0;
3012}
3013
3014/*
3015 * While doing rename detection and pickaxe operation, we may need to
3016 * grab the data for the blob (or file) for our own in-core comparison.
3017 * diff_filespec has data and size fields for this purpose.
3018 */
3019int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
3020{
3021        int size_only = flags & CHECK_SIZE_ONLY;
3022        int err = 0;
3023        /*
3024         * demote FAIL to WARN to allow inspecting the situation
3025         * instead of refusing.
3026         */
3027        enum safe_crlf crlf_warn = (safe_crlf == SAFE_CRLF_FAIL
3028                                    ? SAFE_CRLF_WARN
3029                                    : safe_crlf);
3030
3031        if (!DIFF_FILE_VALID(s))
3032                die("internal error: asking to populate invalid file.");
3033        if (S_ISDIR(s->mode))
3034                return -1;
3035
3036        if (s->data)
3037                return 0;
3038
3039        if (size_only && 0 < s->size)
3040                return 0;
3041
3042        if (S_ISGITLINK(s->mode))
3043                return diff_populate_gitlink(s, size_only);
3044
3045        if (!s->oid_valid ||
3046            reuse_worktree_file(s->path, &s->oid, 0)) {
3047                struct strbuf buf = STRBUF_INIT;
3048                struct stat st;
3049                int fd;
3050
3051                if (lstat(s->path, &st) < 0) {
3052                        if (errno == ENOENT) {
3053                        err_empty:
3054                                err = -1;
3055                        empty:
3056                                s->data = (char *)"";
3057                                s->size = 0;
3058                                return err;
3059                        }
3060                }
3061                s->size = xsize_t(st.st_size);
3062                if (!s->size)
3063                        goto empty;
3064                if (S_ISLNK(st.st_mode)) {
3065                        struct strbuf sb = STRBUF_INIT;
3066
3067                        if (strbuf_readlink(&sb, s->path, s->size))
3068                                goto err_empty;
3069                        s->size = sb.len;
3070                        s->data = strbuf_detach(&sb, NULL);
3071                        s->should_free = 1;
3072                        return 0;
3073                }
3074
3075                /*
3076                 * Even if the caller would be happy with getting
3077                 * only the size, we cannot return early at this
3078                 * point if the path requires us to run the content
3079                 * conversion.
3080                 */
3081                if (size_only && !would_convert_to_git(&the_index, s->path))
3082                        return 0;
3083
3084                /*
3085                 * Note: this check uses xsize_t(st.st_size) that may
3086                 * not be the true size of the blob after it goes
3087                 * through convert_to_git().  This may not strictly be
3088                 * correct, but the whole point of big_file_threshold
3089                 * and is_binary check being that we want to avoid
3090                 * opening the file and inspecting the contents, this
3091                 * is probably fine.
3092                 */
3093                if ((flags & CHECK_BINARY) &&
3094                    s->size > big_file_threshold && s->is_binary == -1) {
3095                        s->is_binary = 1;
3096                        return 0;
3097                }
3098                fd = open(s->path, O_RDONLY);
3099                if (fd < 0)
3100                        goto err_empty;
3101                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3102                close(fd);
3103                s->should_munmap = 1;
3104
3105                /*
3106                 * Convert from working tree format to canonical git format
3107                 */
3108                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, crlf_warn)) {
3109                        size_t size = 0;
3110                        munmap(s->data, s->size);
3111                        s->should_munmap = 0;
3112                        s->data = strbuf_detach(&buf, &size);
3113                        s->size = size;
3114                        s->should_free = 1;
3115                }
3116        }
3117        else {
3118                enum object_type type;
3119                if (size_only || (flags & CHECK_BINARY)) {
3120                        type = sha1_object_info(s->oid.hash, &s->size);
3121                        if (type < 0)
3122                                die("unable to read %s",
3123                                    oid_to_hex(&s->oid));
3124                        if (size_only)
3125                                return 0;
3126                        if (s->size > big_file_threshold && s->is_binary == -1) {
3127                                s->is_binary = 1;
3128                                return 0;
3129                        }
3130                }
3131                s->data = read_sha1_file(s->oid.hash, &type, &s->size);
3132                if (!s->data)
3133                        die("unable to read %s", oid_to_hex(&s->oid));
3134                s->should_free = 1;
3135        }
3136        return 0;
3137}
3138
3139void diff_free_filespec_blob(struct diff_filespec *s)
3140{
3141        if (s->should_free)
3142                free(s->data);
3143        else if (s->should_munmap)
3144                munmap(s->data, s->size);
3145
3146        if (s->should_free || s->should_munmap) {
3147                s->should_free = s->should_munmap = 0;
3148                s->data = NULL;
3149        }
3150}
3151
3152void diff_free_filespec_data(struct diff_filespec *s)
3153{
3154        diff_free_filespec_blob(s);
3155        FREE_AND_NULL(s->cnt_data);
3156}
3157
3158static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
3159                           void *blob,
3160                           unsigned long size,
3161                           const struct object_id *oid,
3162                           int mode)
3163{
3164        int fd;
3165        struct strbuf buf = STRBUF_INIT;
3166        struct strbuf template = STRBUF_INIT;
3167        char *path_dup = xstrdup(path);
3168        const char *base = basename(path_dup);
3169
3170        /* Generate "XXXXXX_basename.ext" */
3171        strbuf_addstr(&template, "XXXXXX_");
3172        strbuf_addstr(&template, base);
3173
3174        fd = mks_tempfile_ts(&temp->tempfile, template.buf, strlen(base) + 1);
3175        if (fd < 0)
3176                die_errno("unable to create temp-file");
3177        if (convert_to_working_tree(path,
3178                        (const char *)blob, (size_t)size, &buf)) {
3179                blob = buf.buf;
3180                size = buf.len;
3181        }
3182        if (write_in_full(fd, blob, size) != size)
3183                die_errno("unable to write temp-file");
3184        close_tempfile(&temp->tempfile);
3185        temp->name = get_tempfile_path(&temp->tempfile);
3186        oid_to_hex_r(temp->hex, oid);
3187        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3188        strbuf_release(&buf);
3189        strbuf_release(&template);
3190        free(path_dup);
3191}
3192
3193static struct diff_tempfile *prepare_temp_file(const char *name,
3194                struct diff_filespec *one)
3195{
3196        struct diff_tempfile *temp = claim_diff_tempfile();
3197
3198        if (!DIFF_FILE_VALID(one)) {
3199        not_a_valid_file:
3200                /* A '-' entry produces this for file-2, and
3201                 * a '+' entry produces this for file-1.
3202                 */
3203                temp->name = "/dev/null";
3204                xsnprintf(temp->hex, sizeof(temp->hex), ".");
3205                xsnprintf(temp->mode, sizeof(temp->mode), ".");
3206                return temp;
3207        }
3208
3209        if (!S_ISGITLINK(one->mode) &&
3210            (!one->oid_valid ||
3211             reuse_worktree_file(name, &one->oid, 1))) {
3212                struct stat st;
3213                if (lstat(name, &st) < 0) {
3214                        if (errno == ENOENT)
3215                                goto not_a_valid_file;
3216                        die_errno("stat(%s)", name);
3217                }
3218                if (S_ISLNK(st.st_mode)) {
3219                        struct strbuf sb = STRBUF_INIT;
3220                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
3221                                die_errno("readlink(%s)", name);
3222                        prep_temp_blob(name, temp, sb.buf, sb.len,
3223                                       (one->oid_valid ?
3224                                        &one->oid : &null_oid),
3225                                       (one->oid_valid ?
3226                                        one->mode : S_IFLNK));
3227                        strbuf_release(&sb);
3228                }
3229                else {
3230                        /* we can borrow from the file in the work tree */
3231                        temp->name = name;
3232                        if (!one->oid_valid)
3233                                oid_to_hex_r(temp->hex, &null_oid);
3234                        else
3235                                oid_to_hex_r(temp->hex, &one->oid);
3236                        /* Even though we may sometimes borrow the
3237                         * contents from the work tree, we always want
3238                         * one->mode.  mode is trustworthy even when
3239                         * !(one->oid_valid), as long as
3240                         * DIFF_FILE_VALID(one).
3241                         */
3242                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
3243                }
3244                return temp;
3245        }
3246        else {
3247                if (diff_populate_filespec(one, 0))
3248                        die("cannot read data blob for %s", one->path);
3249                prep_temp_blob(name, temp, one->data, one->size,
3250                               &one->oid, one->mode);
3251        }
3252        return temp;
3253}
3254
3255static void add_external_diff_name(struct argv_array *argv,
3256                                   const char *name,
3257                                   struct diff_filespec *df)
3258{
3259        struct diff_tempfile *temp = prepare_temp_file(name, df);
3260        argv_array_push(argv, temp->name);
3261        argv_array_push(argv, temp->hex);
3262        argv_array_push(argv, temp->mode);
3263}
3264
3265/* An external diff command takes:
3266 *
3267 * diff-cmd name infile1 infile1-sha1 infile1-mode \
3268 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
3269 *
3270 */
3271static void run_external_diff(const char *pgm,
3272                              const char *name,
3273                              const char *other,
3274                              struct diff_filespec *one,
3275                              struct diff_filespec *two,
3276                              const char *xfrm_msg,
3277                              int complete_rewrite,
3278                              struct diff_options *o)
3279{
3280        struct argv_array argv = ARGV_ARRAY_INIT;
3281        struct argv_array env = ARGV_ARRAY_INIT;
3282        struct diff_queue_struct *q = &diff_queued_diff;
3283
3284        argv_array_push(&argv, pgm);
3285        argv_array_push(&argv, name);
3286
3287        if (one && two) {
3288                add_external_diff_name(&argv, name, one);
3289                if (!other)
3290                        add_external_diff_name(&argv, name, two);
3291                else {
3292                        add_external_diff_name(&argv, other, two);
3293                        argv_array_push(&argv, other);
3294                        argv_array_push(&argv, xfrm_msg);
3295                }
3296        }
3297
3298        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
3299        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
3300
3301        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
3302                die(_("external diff died, stopping at %s"), name);
3303
3304        remove_tempfile();
3305        argv_array_clear(&argv);
3306        argv_array_clear(&env);
3307}
3308
3309static int similarity_index(struct diff_filepair *p)
3310{
3311        return p->score * 100 / MAX_SCORE;
3312}
3313
3314static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
3315{
3316        if (startup_info->have_repository)
3317                return find_unique_abbrev(oid->hash, abbrev);
3318        else {
3319                char *hex = oid_to_hex(oid);
3320                if (abbrev < 0)
3321                        abbrev = FALLBACK_DEFAULT_ABBREV;
3322                if (abbrev > GIT_SHA1_HEXSZ)
3323                        die("BUG: oid abbreviation out of range: %d", abbrev);
3324                if (abbrev)
3325                        hex[abbrev] = '\0';
3326                return hex;
3327        }
3328}
3329
3330static void fill_metainfo(struct strbuf *msg,
3331                          const char *name,
3332                          const char *other,
3333                          struct diff_filespec *one,
3334                          struct diff_filespec *two,
3335                          struct diff_options *o,
3336                          struct diff_filepair *p,
3337                          int *must_show_header,
3338                          int use_color)
3339{
3340        const char *set = diff_get_color(use_color, DIFF_METAINFO);
3341        const char *reset = diff_get_color(use_color, DIFF_RESET);
3342        const char *line_prefix = diff_line_prefix(o);
3343
3344        *must_show_header = 1;
3345        strbuf_init(msg, PATH_MAX * 2 + 300);
3346        switch (p->status) {
3347        case DIFF_STATUS_COPIED:
3348                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3349                            line_prefix, set, similarity_index(p));
3350                strbuf_addf(msg, "%s\n%s%scopy from ",
3351                            reset,  line_prefix, set);
3352                quote_c_style(name, msg, NULL, 0);
3353                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3354                quote_c_style(other, msg, NULL, 0);
3355                strbuf_addf(msg, "%s\n", reset);
3356                break;
3357        case DIFF_STATUS_RENAMED:
3358                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3359                            line_prefix, set, similarity_index(p));
3360                strbuf_addf(msg, "%s\n%s%srename from ",
3361                            reset, line_prefix, set);
3362                quote_c_style(name, msg, NULL, 0);
3363                strbuf_addf(msg, "%s\n%s%srename to ",
3364                            reset, line_prefix, set);
3365                quote_c_style(other, msg, NULL, 0);
3366                strbuf_addf(msg, "%s\n", reset);
3367                break;
3368        case DIFF_STATUS_MODIFIED:
3369                if (p->score) {
3370                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3371                                    line_prefix,
3372                                    set, similarity_index(p), reset);
3373                        break;
3374                }
3375                /* fallthru */
3376        default:
3377                *must_show_header = 0;
3378        }
3379        if (one && two && oidcmp(&one->oid, &two->oid)) {
3380                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
3381
3382                if (DIFF_OPT_TST(o, BINARY)) {
3383                        mmfile_t mf;
3384                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3385                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3386                                abbrev = 40;
3387                }
3388                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
3389                            diff_abbrev_oid(&one->oid, abbrev),
3390                            diff_abbrev_oid(&two->oid, abbrev));
3391                if (one->mode == two->mode)
3392                        strbuf_addf(msg, " %06o", one->mode);
3393                strbuf_addf(msg, "%s\n", reset);
3394        }
3395}
3396
3397static void run_diff_cmd(const char *pgm,
3398                         const char *name,
3399                         const char *other,
3400                         const char *attr_path,
3401                         struct diff_filespec *one,
3402                         struct diff_filespec *two,
3403                         struct strbuf *msg,
3404                         struct diff_options *o,
3405                         struct diff_filepair *p)
3406{
3407        const char *xfrm_msg = NULL;
3408        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3409        int must_show_header = 0;
3410
3411
3412        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3413                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3414                if (drv && drv->external)
3415                        pgm = drv->external;
3416        }
3417
3418        if (msg) {
3419                /*
3420                 * don't use colors when the header is intended for an
3421                 * external diff driver
3422                 */
3423                fill_metainfo(msg, name, other, one, two, o, p,
3424                              &must_show_header,
3425                              want_color(o->use_color) && !pgm);
3426                xfrm_msg = msg->len ? msg->buf : NULL;
3427        }
3428
3429        if (pgm) {
3430                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3431                                  complete_rewrite, o);
3432                return;
3433        }
3434        if (one && two)
3435                builtin_diff(name, other ? other : name,
3436                             one, two, xfrm_msg, must_show_header,
3437                             o, complete_rewrite);
3438        else
3439                fprintf(o->file, "* Unmerged path %s\n", name);
3440}
3441
3442static void diff_fill_oid_info(struct diff_filespec *one)
3443{
3444        if (DIFF_FILE_VALID(one)) {
3445                if (!one->oid_valid) {
3446                        struct stat st;
3447                        if (one->is_stdin) {
3448                                oidclr(&one->oid);
3449                                return;
3450                        }
3451                        if (lstat(one->path, &st) < 0)
3452                                die_errno("stat '%s'", one->path);
3453                        if (index_path(one->oid.hash, one->path, &st, 0))
3454                                die("cannot hash %s", one->path);
3455                }
3456        }
3457        else
3458                oidclr(&one->oid);
3459}
3460
3461static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3462{
3463        /* Strip the prefix but do not molest /dev/null and absolute paths */
3464        if (*namep && **namep != '/') {
3465                *namep += prefix_length;
3466                if (**namep == '/')
3467                        ++*namep;
3468        }
3469        if (*otherp && **otherp != '/') {
3470                *otherp += prefix_length;
3471                if (**otherp == '/')
3472                        ++*otherp;
3473        }
3474}
3475
3476static void run_diff(struct diff_filepair *p, struct diff_options *o)
3477{
3478        const char *pgm = external_diff();
3479        struct strbuf msg;
3480        struct diff_filespec *one = p->one;
3481        struct diff_filespec *two = p->two;
3482        const char *name;
3483        const char *other;
3484        const char *attr_path;
3485
3486        name  = one->path;
3487        other = (strcmp(name, two->path) ? two->path : NULL);
3488        attr_path = name;
3489        if (o->prefix_length)
3490                strip_prefix(o->prefix_length, &name, &other);
3491
3492        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3493                pgm = NULL;
3494
3495        if (DIFF_PAIR_UNMERGED(p)) {
3496                run_diff_cmd(pgm, name, NULL, attr_path,
3497                             NULL, NULL, NULL, o, p);
3498                return;
3499        }
3500
3501        diff_fill_oid_info(one);
3502        diff_fill_oid_info(two);
3503
3504        if (!pgm &&
3505            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3506            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3507                /*
3508                 * a filepair that changes between file and symlink
3509                 * needs to be split into deletion and creation.
3510                 */
3511                struct diff_filespec *null = alloc_filespec(two->path);
3512                run_diff_cmd(NULL, name, other, attr_path,
3513                             one, null, &msg, o, p);
3514                free(null);
3515                strbuf_release(&msg);
3516
3517                null = alloc_filespec(one->path);
3518                run_diff_cmd(NULL, name, other, attr_path,
3519                             null, two, &msg, o, p);
3520                free(null);
3521        }
3522        else
3523                run_diff_cmd(pgm, name, other, attr_path,
3524                             one, two, &msg, o, p);
3525
3526        strbuf_release(&msg);
3527}
3528
3529static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3530                         struct diffstat_t *diffstat)
3531{
3532        const char *name;
3533        const char *other;
3534
3535        if (DIFF_PAIR_UNMERGED(p)) {
3536                /* unmerged */
3537                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
3538                return;
3539        }
3540
3541        name = p->one->path;
3542        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3543
3544        if (o->prefix_length)
3545                strip_prefix(o->prefix_length, &name, &other);
3546
3547        diff_fill_oid_info(p->one);
3548        diff_fill_oid_info(p->two);
3549
3550        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
3551}
3552
3553static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3554{
3555        const char *name;
3556        const char *other;
3557        const char *attr_path;
3558
3559        if (DIFF_PAIR_UNMERGED(p)) {
3560                /* unmerged */
3561                return;
3562        }
3563
3564        name = p->one->path;
3565        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3566        attr_path = other ? other : name;
3567
3568        if (o->prefix_length)
3569                strip_prefix(o->prefix_length, &name, &other);
3570
3571        diff_fill_oid_info(p->one);
3572        diff_fill_oid_info(p->two);
3573
3574        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3575}
3576
3577void diff_setup(struct diff_options *options)
3578{
3579        memcpy(options, &default_diff_options, sizeof(*options));
3580
3581        options->file = stdout;
3582
3583        options->abbrev = DEFAULT_ABBREV;
3584        options->line_termination = '\n';
3585        options->break_opt = -1;
3586        options->rename_limit = -1;
3587        options->dirstat_permille = diff_dirstat_permille_default;
3588        options->context = diff_context_default;
3589        options->interhunkcontext = diff_interhunk_context_default;
3590        options->ws_error_highlight = ws_error_highlight_default;
3591        DIFF_OPT_SET(options, RENAME_EMPTY);
3592
3593        /* pathchange left =NULL by default */
3594        options->change = diff_change;
3595        options->add_remove = diff_addremove;
3596        options->use_color = diff_use_color_default;
3597        options->detect_rename = diff_detect_rename_default;
3598        options->xdl_opts |= diff_algorithm;
3599        if (diff_indent_heuristic)
3600                DIFF_XDL_SET(options, INDENT_HEURISTIC);
3601
3602        options->orderfile = diff_order_file_cfg;
3603
3604        if (diff_no_prefix) {
3605                options->a_prefix = options->b_prefix = "";
3606        } else if (!diff_mnemonic_prefix) {
3607                options->a_prefix = "a/";
3608                options->b_prefix = "b/";
3609        }
3610}
3611
3612void diff_setup_done(struct diff_options *options)
3613{
3614        int count = 0;
3615
3616        if (options->set_default)
3617                options->set_default(options);
3618
3619        if (options->output_format & DIFF_FORMAT_NAME)
3620                count++;
3621        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3622                count++;
3623        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3624                count++;
3625        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3626                count++;
3627        if (count > 1)
3628                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
3629
3630        /*
3631         * Most of the time we can say "there are changes"
3632         * only by checking if there are changed paths, but
3633         * --ignore-whitespace* options force us to look
3634         * inside contents.
3635         */
3636
3637        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3638            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3639            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3640                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3641        else
3642                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3643
3644        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3645                options->detect_rename = DIFF_DETECT_COPY;
3646
3647        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3648                options->prefix = NULL;
3649        if (options->prefix)
3650                options->prefix_length = strlen(options->prefix);
3651        else
3652                options->prefix_length = 0;
3653
3654        if (options->output_format & (DIFF_FORMAT_NAME |
3655                                      DIFF_FORMAT_NAME_STATUS |
3656                                      DIFF_FORMAT_CHECKDIFF |
3657                                      DIFF_FORMAT_NO_OUTPUT))
3658                options->output_format &= ~(DIFF_FORMAT_RAW |
3659                                            DIFF_FORMAT_NUMSTAT |
3660                                            DIFF_FORMAT_DIFFSTAT |
3661                                            DIFF_FORMAT_SHORTSTAT |
3662                                            DIFF_FORMAT_DIRSTAT |
3663                                            DIFF_FORMAT_SUMMARY |
3664                                            DIFF_FORMAT_PATCH);
3665
3666        /*
3667         * These cases always need recursive; we do not drop caller-supplied
3668         * recursive bits for other formats here.
3669         */
3670        if (options->output_format & (DIFF_FORMAT_PATCH |
3671                                      DIFF_FORMAT_NUMSTAT |
3672                                      DIFF_FORMAT_DIFFSTAT |
3673                                      DIFF_FORMAT_SHORTSTAT |
3674                                      DIFF_FORMAT_DIRSTAT |
3675                                      DIFF_FORMAT_SUMMARY |
3676                                      DIFF_FORMAT_CHECKDIFF))
3677                DIFF_OPT_SET(options, RECURSIVE);
3678        /*
3679         * Also pickaxe would not work very well if you do not say recursive
3680         */
3681        if (options->pickaxe)
3682                DIFF_OPT_SET(options, RECURSIVE);
3683        /*
3684         * When patches are generated, submodules diffed against the work tree
3685         * must be checked for dirtiness too so it can be shown in the output
3686         */
3687        if (options->output_format & DIFF_FORMAT_PATCH)
3688                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3689
3690        if (options->detect_rename && options->rename_limit < 0)
3691                options->rename_limit = diff_rename_limit_default;
3692        if (options->setup & DIFF_SETUP_USE_CACHE) {
3693                if (!active_cache)
3694                        /* read-cache does not die even when it fails
3695                         * so it is safe for us to do this here.  Also
3696                         * it does not smudge active_cache or active_nr
3697                         * when it fails, so we do not have to worry about
3698                         * cleaning it up ourselves either.
3699                         */
3700                        read_cache();
3701        }
3702        if (40 < options->abbrev)
3703                options->abbrev = 40; /* full */
3704
3705        /*
3706         * It does not make sense to show the first hit we happened
3707         * to have found.  It does not make sense not to return with
3708         * exit code in such a case either.
3709         */
3710        if (DIFF_OPT_TST(options, QUICK)) {
3711                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3712                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3713        }
3714
3715        options->diff_path_counter = 0;
3716
3717        if (DIFF_OPT_TST(options, FOLLOW_RENAMES) && options->pathspec.nr != 1)
3718                die(_("--follow requires exactly one pathspec"));
3719}
3720
3721static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3722{
3723        char c, *eq;
3724        int len;
3725
3726        if (*arg != '-')
3727                return 0;
3728        c = *++arg;
3729        if (!c)
3730                return 0;
3731        if (c == arg_short) {
3732                c = *++arg;
3733                if (!c)
3734                        return 1;
3735                if (val && isdigit(c)) {
3736                        char *end;
3737                        int n = strtoul(arg, &end, 10);
3738                        if (*end)
3739                                return 0;
3740                        *val = n;
3741                        return 1;
3742                }
3743                return 0;
3744        }
3745        if (c != '-')
3746                return 0;
3747        arg++;
3748        eq = strchrnul(arg, '=');
3749        len = eq - arg;
3750        if (!len || strncmp(arg, arg_long, len))
3751                return 0;
3752        if (*eq) {
3753                int n;
3754                char *end;
3755                if (!isdigit(*++eq))
3756                        return 0;
3757                n = strtoul(eq, &end, 10);
3758                if (*end)
3759                        return 0;
3760                *val = n;
3761        }
3762        return 1;
3763}
3764
3765static int diff_scoreopt_parse(const char *opt);
3766
3767static inline int short_opt(char opt, const char **argv,
3768                            const char **optarg)
3769{
3770        const char *arg = argv[0];
3771        if (arg[0] != '-' || arg[1] != opt)
3772                return 0;
3773        if (arg[2] != '\0') {
3774                *optarg = arg + 2;
3775                return 1;
3776        }
3777        if (!argv[1])
3778                die("Option '%c' requires a value", opt);
3779        *optarg = argv[1];
3780        return 2;
3781}
3782
3783int parse_long_opt(const char *opt, const char **argv,
3784                   const char **optarg)
3785{
3786        const char *arg = argv[0];
3787        if (!skip_prefix(arg, "--", &arg))
3788                return 0;
3789        if (!skip_prefix(arg, opt, &arg))
3790                return 0;
3791        if (*arg == '=') { /* stuck form: --option=value */
3792                *optarg = arg + 1;
3793                return 1;
3794        }
3795        if (*arg != '\0')
3796                return 0;
3797        /* separate form: --option value */
3798        if (!argv[1])
3799                die("Option '--%s' requires a value", opt);
3800        *optarg = argv[1];
3801        return 2;
3802}
3803
3804static int stat_opt(struct diff_options *options, const char **av)
3805{
3806        const char *arg = av[0];
3807        char *end;
3808        int width = options->stat_width;
3809        int name_width = options->stat_name_width;
3810        int graph_width = options->stat_graph_width;
3811        int count = options->stat_count;
3812        int argcount = 1;
3813
3814        if (!skip_prefix(arg, "--stat", &arg))
3815                die("BUG: stat option does not begin with --stat: %s", arg);
3816        end = (char *)arg;
3817
3818        switch (*arg) {
3819        case '-':
3820                if (skip_prefix(arg, "-width", &arg)) {
3821                        if (*arg == '=')
3822                                width = strtoul(arg + 1, &end, 10);
3823                        else if (!*arg && !av[1])
3824                                die_want_option("--stat-width");
3825                        else if (!*arg) {
3826                                width = strtoul(av[1], &end, 10);
3827                                argcount = 2;
3828                        }
3829                } else if (skip_prefix(arg, "-name-width", &arg)) {
3830                        if (*arg == '=')
3831                                name_width = strtoul(arg + 1, &end, 10);
3832                        else if (!*arg && !av[1])
3833                                die_want_option("--stat-name-width");
3834                        else if (!*arg) {
3835                                name_width = strtoul(av[1], &end, 10);
3836                                argcount = 2;
3837                        }
3838                } else if (skip_prefix(arg, "-graph-width", &arg)) {
3839                        if (*arg == '=')
3840                                graph_width = strtoul(arg + 1, &end, 10);
3841                        else if (!*arg && !av[1])
3842                                die_want_option("--stat-graph-width");
3843                        else if (!*arg) {
3844                                graph_width = strtoul(av[1], &end, 10);
3845                                argcount = 2;
3846                        }
3847                } else if (skip_prefix(arg, "-count", &arg)) {
3848                        if (*arg == '=')
3849                                count = strtoul(arg + 1, &end, 10);
3850                        else if (!*arg && !av[1])
3851                                die_want_option("--stat-count");
3852                        else if (!*arg) {
3853                                count = strtoul(av[1], &end, 10);
3854                                argcount = 2;
3855                        }
3856                }
3857                break;
3858        case '=':
3859                width = strtoul(arg+1, &end, 10);
3860                if (*end == ',')
3861                        name_width = strtoul(end+1, &end, 10);
3862                if (*end == ',')
3863                        count = strtoul(end+1, &end, 10);
3864        }
3865
3866        /* Important! This checks all the error cases! */
3867        if (*end)
3868                return 0;
3869        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3870        options->stat_name_width = name_width;
3871        options->stat_graph_width = graph_width;
3872        options->stat_width = width;
3873        options->stat_count = count;
3874        return argcount;
3875}
3876
3877static int parse_dirstat_opt(struct diff_options *options, const char *params)
3878{
3879        struct strbuf errmsg = STRBUF_INIT;
3880        if (parse_dirstat_params(options, params, &errmsg))
3881                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3882                    errmsg.buf);
3883        strbuf_release(&errmsg);
3884        /*
3885         * The caller knows a dirstat-related option is given from the command
3886         * line; allow it to say "return this_function();"
3887         */
3888        options->output_format |= DIFF_FORMAT_DIRSTAT;
3889        return 1;
3890}
3891
3892static int parse_submodule_opt(struct diff_options *options, const char *value)
3893{
3894        if (parse_submodule_params(options, value))
3895                die(_("Failed to parse --submodule option parameter: '%s'"),
3896                        value);
3897        return 1;
3898}
3899
3900static const char diff_status_letters[] = {
3901        DIFF_STATUS_ADDED,
3902        DIFF_STATUS_COPIED,
3903        DIFF_STATUS_DELETED,
3904        DIFF_STATUS_MODIFIED,
3905        DIFF_STATUS_RENAMED,
3906        DIFF_STATUS_TYPE_CHANGED,
3907        DIFF_STATUS_UNKNOWN,
3908        DIFF_STATUS_UNMERGED,
3909        DIFF_STATUS_FILTER_AON,
3910        DIFF_STATUS_FILTER_BROKEN,
3911        '\0',
3912};
3913
3914static unsigned int filter_bit['Z' + 1];
3915
3916static void prepare_filter_bits(void)
3917{
3918        int i;
3919
3920        if (!filter_bit[DIFF_STATUS_ADDED]) {
3921                for (i = 0; diff_status_letters[i]; i++)
3922                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
3923        }
3924}
3925
3926static unsigned filter_bit_tst(char status, const struct diff_options *opt)
3927{
3928        return opt->filter & filter_bit[(int) status];
3929}
3930
3931static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
3932{
3933        int i, optch;
3934
3935        prepare_filter_bits();
3936
3937        /*
3938         * If there is a negation e.g. 'd' in the input, and we haven't
3939         * initialized the filter field with another --diff-filter, start
3940         * from full set of bits, except for AON.
3941         */
3942        if (!opt->filter) {
3943                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3944                        if (optch < 'a' || 'z' < optch)
3945                                continue;
3946                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
3947                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
3948                        break;
3949                }
3950        }
3951
3952        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3953                unsigned int bit;
3954                int negate;
3955
3956                if ('a' <= optch && optch <= 'z') {
3957                        negate = 1;
3958                        optch = toupper(optch);
3959                } else {
3960                        negate = 0;
3961                }
3962
3963                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
3964                if (!bit)
3965                        return optarg[i];
3966                if (negate)
3967                        opt->filter &= ~bit;
3968                else
3969                        opt->filter |= bit;
3970        }
3971        return 0;
3972}
3973
3974static void enable_patch_output(int *fmt) {
3975        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
3976        *fmt |= DIFF_FORMAT_PATCH;
3977}
3978
3979static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
3980{
3981        int val = parse_ws_error_highlight(arg);
3982
3983        if (val < 0) {
3984                error("unknown value after ws-error-highlight=%.*s",
3985                      -1 - val, arg);
3986                return 0;
3987        }
3988        opt->ws_error_highlight = val;
3989        return 1;
3990}
3991
3992int diff_opt_parse(struct diff_options *options,
3993                   const char **av, int ac, const char *prefix)
3994{
3995        const char *arg = av[0];
3996        const char *optarg;
3997        int argcount;
3998
3999        if (!prefix)
4000                prefix = "";
4001
4002        /* Output format options */
4003        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4004            || opt_arg(arg, 'U', "unified", &options->context))
4005                enable_patch_output(&options->output_format);
4006        else if (!strcmp(arg, "--raw"))
4007                options->output_format |= DIFF_FORMAT_RAW;
4008        else if (!strcmp(arg, "--patch-with-raw")) {
4009                enable_patch_output(&options->output_format);
4010                options->output_format |= DIFF_FORMAT_RAW;
4011        } else if (!strcmp(arg, "--numstat"))
4012                options->output_format |= DIFF_FORMAT_NUMSTAT;
4013        else if (!strcmp(arg, "--shortstat"))
4014                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4015        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
4016                return parse_dirstat_opt(options, "");
4017        else if (skip_prefix(arg, "-X", &arg))
4018                return parse_dirstat_opt(options, arg);
4019        else if (skip_prefix(arg, "--dirstat=", &arg))
4020                return parse_dirstat_opt(options, arg);
4021        else if (!strcmp(arg, "--cumulative"))
4022                return parse_dirstat_opt(options, "cumulative");
4023        else if (!strcmp(arg, "--dirstat-by-file"))
4024                return parse_dirstat_opt(options, "files");
4025        else if (skip_prefix(arg, "--dirstat-by-file=", &arg)) {
4026                parse_dirstat_opt(options, "files");
4027                return parse_dirstat_opt(options, arg);
4028        }
4029        else if (!strcmp(arg, "--check"))
4030                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4031        else if (!strcmp(arg, "--summary"))
4032                options->output_format |= DIFF_FORMAT_SUMMARY;
4033        else if (!strcmp(arg, "--patch-with-stat")) {
4034                enable_patch_output(&options->output_format);
4035                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4036        } else if (!strcmp(arg, "--name-only"))
4037                options->output_format |= DIFF_FORMAT_NAME;
4038        else if (!strcmp(arg, "--name-status"))
4039                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4040        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4041                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4042        else if (starts_with(arg, "--stat"))
4043                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4044                return stat_opt(options, av);
4045
4046        /* renames options */
4047        else if (starts_with(arg, "-B") || starts_with(arg, "--break-rewrites=") ||
4048                 !strcmp(arg, "--break-rewrites")) {
4049                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4050                        return error("invalid argument to -B: %s", arg+2);
4051        }
4052        else if (starts_with(arg, "-M") || starts_with(arg, "--find-renames=") ||
4053                 !strcmp(arg, "--find-renames")) {
4054                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4055                        return error("invalid argument to -M: %s", arg+2);
4056                options->detect_rename = DIFF_DETECT_RENAME;
4057        }
4058        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4059                options->irreversible_delete = 1;
4060        }
4061        else if (starts_with(arg, "-C") || starts_with(arg, "--find-copies=") ||
4062                 !strcmp(arg, "--find-copies")) {
4063                if (options->detect_rename == DIFF_DETECT_COPY)
4064                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
4065                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4066                        return error("invalid argument to -C: %s", arg+2);
4067                options->detect_rename = DIFF_DETECT_COPY;
4068        }
4069        else if (!strcmp(arg, "--no-renames"))
4070                options->detect_rename = 0;
4071        else if (!strcmp(arg, "--rename-empty"))
4072                DIFF_OPT_SET(options, RENAME_EMPTY);
4073        else if (!strcmp(arg, "--no-rename-empty"))
4074                DIFF_OPT_CLR(options, RENAME_EMPTY);
4075        else if (!strcmp(arg, "--relative"))
4076                DIFF_OPT_SET(options, RELATIVE_NAME);
4077        else if (skip_prefix(arg, "--relative=", &arg)) {
4078                DIFF_OPT_SET(options, RELATIVE_NAME);
4079                options->prefix = arg;
4080        }
4081
4082        /* xdiff options */
4083        else if (!strcmp(arg, "--minimal"))
4084                DIFF_XDL_SET(options, NEED_MINIMAL);
4085        else if (!strcmp(arg, "--no-minimal"))
4086                DIFF_XDL_CLR(options, NEED_MINIMAL);
4087        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4088                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4089        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4090                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4091        else if (!strcmp(arg, "--ignore-space-at-eol"))
4092                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4093        else if (!strcmp(arg, "--ignore-blank-lines"))
4094                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4095        else if (!strcmp(arg, "--indent-heuristic"))
4096                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4097        else if (!strcmp(arg, "--no-indent-heuristic"))
4098                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4099        else if (!strcmp(arg, "--patience"))
4100                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4101        else if (!strcmp(arg, "--histogram"))
4102                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4103        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4104                long value = parse_algorithm_value(optarg);
4105                if (value < 0)
4106                        return error("option diff-algorithm accepts \"myers\", "
4107                                     "\"minimal\", \"patience\" and \"histogram\"");
4108                /* clear out previous settings */
4109                DIFF_XDL_CLR(options, NEED_MINIMAL);
4110                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4111                options->xdl_opts |= value;
4112                return argcount;
4113        }
4114
4115        /* flags options */
4116        else if (!strcmp(arg, "--binary")) {
4117                enable_patch_output(&options->output_format);
4118                DIFF_OPT_SET(options, BINARY);
4119        }
4120        else if (!strcmp(arg, "--full-index"))
4121                DIFF_OPT_SET(options, FULL_INDEX);
4122        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4123                DIFF_OPT_SET(options, TEXT);
4124        else if (!strcmp(arg, "-R"))
4125                DIFF_OPT_SET(options, REVERSE_DIFF);
4126        else if (!strcmp(arg, "--find-copies-harder"))
4127                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
4128        else if (!strcmp(arg, "--follow"))
4129                DIFF_OPT_SET(options, FOLLOW_RENAMES);
4130        else if (!strcmp(arg, "--no-follow")) {
4131                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
4132                DIFF_OPT_CLR(options, DEFAULT_FOLLOW_RENAMES);
4133        } else if (!strcmp(arg, "--color"))
4134                options->use_color = 1;
4135        else if (skip_prefix(arg, "--color=", &arg)) {
4136                int value = git_config_colorbool(NULL, arg);
4137                if (value < 0)
4138                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4139                options->use_color = value;
4140        }
4141        else if (!strcmp(arg, "--no-color"))
4142                options->use_color = 0;
4143        else if (!strcmp(arg, "--color-words")) {
4144                options->use_color = 1;
4145                options->word_diff = DIFF_WORDS_COLOR;
4146        }
4147        else if (skip_prefix(arg, "--color-words=", &arg)) {
4148                options->use_color = 1;
4149                options->word_diff = DIFF_WORDS_COLOR;
4150                options->word_regex = arg;
4151        }
4152        else if (!strcmp(arg, "--word-diff")) {
4153                if (options->word_diff == DIFF_WORDS_NONE)
4154                        options->word_diff = DIFF_WORDS_PLAIN;
4155        }
4156        else if (skip_prefix(arg, "--word-diff=", &arg)) {
4157                if (!strcmp(arg, "plain"))
4158                        options->word_diff = DIFF_WORDS_PLAIN;
4159                else if (!strcmp(arg, "color")) {
4160                        options->use_color = 1;
4161                        options->word_diff = DIFF_WORDS_COLOR;
4162                }
4163                else if (!strcmp(arg, "porcelain"))
4164                        options->word_diff = DIFF_WORDS_PORCELAIN;
4165                else if (!strcmp(arg, "none"))
4166                        options->word_diff = DIFF_WORDS_NONE;
4167                else
4168                        die("bad --word-diff argument: %s", arg);
4169        }
4170        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
4171                if (options->word_diff == DIFF_WORDS_NONE)
4172                        options->word_diff = DIFF_WORDS_PLAIN;
4173                options->word_regex = optarg;
4174                return argcount;
4175        }
4176        else if (!strcmp(arg, "--exit-code"))
4177                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
4178        else if (!strcmp(arg, "--quiet"))
4179                DIFF_OPT_SET(options, QUICK);
4180        else if (!strcmp(arg, "--ext-diff"))
4181                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
4182        else if (!strcmp(arg, "--no-ext-diff"))
4183                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
4184        else if (!strcmp(arg, "--textconv"))
4185                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
4186        else if (!strcmp(arg, "--no-textconv"))
4187                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
4188        else if (!strcmp(arg, "--ignore-submodules")) {
4189                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
4190                handle_ignore_submodules_arg(options, "all");
4191        } else if (skip_prefix(arg, "--ignore-submodules=", &arg)) {
4192                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
4193                handle_ignore_submodules_arg(options, arg);
4194        } else if (!strcmp(arg, "--submodule"))
4195                options->submodule_format = DIFF_SUBMODULE_LOG;
4196        else if (skip_prefix(arg, "--submodule=", &arg))
4197                return parse_submodule_opt(options, arg);
4198        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
4199                return parse_ws_error_highlight_opt(options, arg);
4200        else if (!strcmp(arg, "--ita-invisible-in-index"))
4201                options->ita_invisible_in_index = 1;
4202        else if (!strcmp(arg, "--ita-visible-in-index"))
4203                options->ita_invisible_in_index = 0;
4204
4205        /* misc options */
4206        else if (!strcmp(arg, "-z"))
4207                options->line_termination = 0;
4208        else if ((argcount = short_opt('l', av, &optarg))) {
4209                options->rename_limit = strtoul(optarg, NULL, 10);
4210                return argcount;
4211        }
4212        else if ((argcount = short_opt('S', av, &optarg))) {
4213                options->pickaxe = optarg;
4214                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
4215                return argcount;
4216        } else if ((argcount = short_opt('G', av, &optarg))) {
4217                options->pickaxe = optarg;
4218                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
4219                return argcount;
4220        }
4221        else if (!strcmp(arg, "--pickaxe-all"))
4222                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
4223        else if (!strcmp(arg, "--pickaxe-regex"))
4224                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
4225        else if ((argcount = short_opt('O', av, &optarg))) {
4226                options->orderfile = prefix_filename(prefix, optarg);
4227                return argcount;
4228        }
4229        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
4230                int offending = parse_diff_filter_opt(optarg, options);
4231                if (offending)
4232                        die("unknown change class '%c' in --diff-filter=%s",
4233                            offending, optarg);
4234                return argcount;
4235        }
4236        else if (!strcmp(arg, "--no-abbrev"))
4237                options->abbrev = 0;
4238        else if (!strcmp(arg, "--abbrev"))
4239                options->abbrev = DEFAULT_ABBREV;
4240        else if (skip_prefix(arg, "--abbrev=", &arg)) {
4241                options->abbrev = strtoul(arg, NULL, 10);
4242                if (options->abbrev < MINIMUM_ABBREV)
4243                        options->abbrev = MINIMUM_ABBREV;
4244                else if (40 < options->abbrev)
4245                        options->abbrev = 40;
4246        }
4247        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
4248                options->a_prefix = optarg;
4249                return argcount;
4250        }
4251        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
4252                options->line_prefix = optarg;
4253                options->line_prefix_length = strlen(options->line_prefix);
4254                graph_setup_line_prefix(options);
4255                return argcount;
4256        }
4257        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
4258                options->b_prefix = optarg;
4259                return argcount;
4260        }
4261        else if (!strcmp(arg, "--no-prefix"))
4262                options->a_prefix = options->b_prefix = "";
4263        else if (opt_arg(arg, '\0', "inter-hunk-context",
4264                         &options->interhunkcontext))
4265                ;
4266        else if (!strcmp(arg, "-W"))
4267                DIFF_OPT_SET(options, FUNCCONTEXT);
4268        else if (!strcmp(arg, "--function-context"))
4269                DIFF_OPT_SET(options, FUNCCONTEXT);
4270        else if (!strcmp(arg, "--no-function-context"))
4271                DIFF_OPT_CLR(options, FUNCCONTEXT);
4272        else if ((argcount = parse_long_opt("output", av, &optarg))) {
4273                char *path = prefix_filename(prefix, optarg);
4274                options->file = xfopen(path, "w");
4275                options->close_file = 1;
4276                if (options->use_color != GIT_COLOR_ALWAYS)
4277                        options->use_color = GIT_COLOR_NEVER;
4278                free(path);
4279                return argcount;
4280        } else
4281                return 0;
4282        return 1;
4283}
4284
4285int parse_rename_score(const char **cp_p)
4286{
4287        unsigned long num, scale;
4288        int ch, dot;
4289        const char *cp = *cp_p;
4290
4291        num = 0;
4292        scale = 1;
4293        dot = 0;
4294        for (;;) {
4295                ch = *cp;
4296                if ( !dot && ch == '.' ) {
4297                        scale = 1;
4298                        dot = 1;
4299                } else if ( ch == '%' ) {
4300                        scale = dot ? scale*100 : 100;
4301                        cp++;   /* % is always at the end */
4302                        break;
4303                } else if ( ch >= '0' && ch <= '9' ) {
4304                        if ( scale < 100000 ) {
4305                                scale *= 10;
4306                                num = (num*10) + (ch-'0');
4307                        }
4308                } else {
4309                        break;
4310                }
4311                cp++;
4312        }
4313        *cp_p = cp;
4314
4315        /* user says num divided by scale and we say internally that
4316         * is MAX_SCORE * num / scale.
4317         */
4318        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
4319}
4320
4321static int diff_scoreopt_parse(const char *opt)
4322{
4323        int opt1, opt2, cmd;
4324
4325        if (*opt++ != '-')
4326                return -1;
4327        cmd = *opt++;
4328        if (cmd == '-') {
4329                /* convert the long-form arguments into short-form versions */
4330                if (skip_prefix(opt, "break-rewrites", &opt)) {
4331                        if (*opt == 0 || *opt++ == '=')
4332                                cmd = 'B';
4333                } else if (skip_prefix(opt, "find-copies", &opt)) {
4334                        if (*opt == 0 || *opt++ == '=')
4335                                cmd = 'C';
4336                } else if (skip_prefix(opt, "find-renames", &opt)) {
4337                        if (*opt == 0 || *opt++ == '=')
4338                                cmd = 'M';
4339                }
4340        }
4341        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
4342                return -1; /* that is not a -M, -C, or -B option */
4343
4344        opt1 = parse_rename_score(&opt);
4345        if (cmd != 'B')
4346                opt2 = 0;
4347        else {
4348                if (*opt == 0)
4349                        opt2 = 0;
4350                else if (*opt != '/')
4351                        return -1; /* we expect -B80/99 or -B80 */
4352                else {
4353                        opt++;
4354                        opt2 = parse_rename_score(&opt);
4355                }
4356        }
4357        if (*opt != 0)
4358                return -1;
4359        return opt1 | (opt2 << 16);
4360}
4361
4362struct diff_queue_struct diff_queued_diff;
4363
4364void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
4365{
4366        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
4367        queue->queue[queue->nr++] = dp;
4368}
4369
4370struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
4371                                 struct diff_filespec *one,
4372                                 struct diff_filespec *two)
4373{
4374        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
4375        dp->one = one;
4376        dp->two = two;
4377        if (queue)
4378                diff_q(queue, dp);
4379        return dp;
4380}
4381
4382void diff_free_filepair(struct diff_filepair *p)
4383{
4384        free_filespec(p->one);
4385        free_filespec(p->two);
4386        free(p);
4387}
4388
4389const char *diff_aligned_abbrev(const struct object_id *oid, int len)
4390{
4391        int abblen;
4392        const char *abbrev;
4393
4394        if (len == GIT_SHA1_HEXSZ)
4395                return oid_to_hex(oid);
4396
4397        abbrev = diff_abbrev_oid(oid, len);
4398        abblen = strlen(abbrev);
4399
4400        /*
4401         * In well-behaved cases, where the abbbreviated result is the
4402         * same as the requested length, append three dots after the
4403         * abbreviation (hence the whole logic is limited to the case
4404         * where abblen < 37); when the actual abbreviated result is a
4405         * bit longer than the requested length, we reduce the number
4406         * of dots so that they match the well-behaved ones.  However,
4407         * if the actual abbreviation is longer than the requested
4408         * length by more than three, we give up on aligning, and add
4409         * three dots anyway, to indicate that the output is not the
4410         * full object name.  Yes, this may be suboptimal, but this
4411         * appears only in "diff --raw --abbrev" output and it is not
4412         * worth the effort to change it now.  Note that this would
4413         * likely to work fine when the automatic sizing of default
4414         * abbreviation length is used--we would be fed -1 in "len" in
4415         * that case, and will end up always appending three-dots, but
4416         * the automatic sizing is supposed to give abblen that ensures
4417         * uniqueness across all objects (statistically speaking).
4418         */
4419        if (abblen < GIT_SHA1_HEXSZ - 3) {
4420                static char hex[GIT_MAX_HEXSZ + 1];
4421                if (len < abblen && abblen <= len + 2)
4422                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
4423                else
4424                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
4425                return hex;
4426        }
4427
4428        return oid_to_hex(oid);
4429}
4430
4431static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4432{
4433        int line_termination = opt->line_termination;
4434        int inter_name_termination = line_termination ? '\t' : '\0';
4435
4436        fprintf(opt->file, "%s", diff_line_prefix(opt));
4437        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
4438                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
4439                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
4440                fprintf(opt->file, "%s ",
4441                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
4442        }
4443        if (p->score) {
4444                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
4445                        inter_name_termination);
4446        } else {
4447                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
4448        }
4449
4450        if (p->status == DIFF_STATUS_COPIED ||
4451            p->status == DIFF_STATUS_RENAMED) {
4452                const char *name_a, *name_b;
4453                name_a = p->one->path;
4454                name_b = p->two->path;
4455                strip_prefix(opt->prefix_length, &name_a, &name_b);
4456                write_name_quoted(name_a, opt->file, inter_name_termination);
4457                write_name_quoted(name_b, opt->file, line_termination);
4458        } else {
4459                const char *name_a, *name_b;
4460                name_a = p->one->mode ? p->one->path : p->two->path;
4461                name_b = NULL;
4462                strip_prefix(opt->prefix_length, &name_a, &name_b);
4463                write_name_quoted(name_a, opt->file, line_termination);
4464        }
4465}
4466
4467int diff_unmodified_pair(struct diff_filepair *p)
4468{
4469        /* This function is written stricter than necessary to support
4470         * the currently implemented transformers, but the idea is to
4471         * let transformers to produce diff_filepairs any way they want,
4472         * and filter and clean them up here before producing the output.
4473         */
4474        struct diff_filespec *one = p->one, *two = p->two;
4475
4476        if (DIFF_PAIR_UNMERGED(p))
4477                return 0; /* unmerged is interesting */
4478
4479        /* deletion, addition, mode or type change
4480         * and rename are all interesting.
4481         */
4482        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
4483            DIFF_PAIR_MODE_CHANGED(p) ||
4484            strcmp(one->path, two->path))
4485                return 0;
4486
4487        /* both are valid and point at the same path.  that is, we are
4488         * dealing with a change.
4489         */
4490        if (one->oid_valid && two->oid_valid &&
4491            !oidcmp(&one->oid, &two->oid) &&
4492            !one->dirty_submodule && !two->dirty_submodule)
4493                return 1; /* no change */
4494        if (!one->oid_valid && !two->oid_valid)
4495                return 1; /* both look at the same file on the filesystem. */
4496        return 0;
4497}
4498
4499static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
4500{
4501        if (diff_unmodified_pair(p))
4502                return;
4503
4504        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4505            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4506                return; /* no tree diffs in patch format */
4507
4508        run_diff(p, o);
4509}
4510
4511static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
4512                            struct diffstat_t *diffstat)
4513{
4514        if (diff_unmodified_pair(p))
4515                return;
4516
4517        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4518            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4519                return; /* no useful stat for tree diffs */
4520
4521        run_diffstat(p, o, diffstat);
4522}
4523
4524static void diff_flush_checkdiff(struct diff_filepair *p,
4525                struct diff_options *o)
4526{
4527        if (diff_unmodified_pair(p))
4528                return;
4529
4530        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4531            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4532                return; /* nothing to check in tree diffs */
4533
4534        run_checkdiff(p, o);
4535}
4536
4537int diff_queue_is_empty(void)
4538{
4539        struct diff_queue_struct *q = &diff_queued_diff;
4540        int i;
4541        for (i = 0; i < q->nr; i++)
4542                if (!diff_unmodified_pair(q->queue[i]))
4543                        return 0;
4544        return 1;
4545}
4546
4547#if DIFF_DEBUG
4548void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
4549{
4550        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
4551                x, one ? one : "",
4552                s->path,
4553                DIFF_FILE_VALID(s) ? "valid" : "invalid",
4554                s->mode,
4555                s->oid_valid ? oid_to_hex(&s->oid) : "");
4556        fprintf(stderr, "queue[%d] %s size %lu\n",
4557                x, one ? one : "",
4558                s->size);
4559}
4560
4561void diff_debug_filepair(const struct diff_filepair *p, int i)
4562{
4563        diff_debug_filespec(p->one, i, "one");
4564        diff_debug_filespec(p->two, i, "two");
4565        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4566                p->score, p->status ? p->status : '?',
4567                p->one->rename_used, p->broken_pair);
4568}
4569
4570void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4571{
4572        int i;
4573        if (msg)
4574                fprintf(stderr, "%s\n", msg);
4575        fprintf(stderr, "q->nr = %d\n", q->nr);
4576        for (i = 0; i < q->nr; i++) {
4577                struct diff_filepair *p = q->queue[i];
4578                diff_debug_filepair(p, i);
4579        }
4580}
4581#endif
4582
4583static void diff_resolve_rename_copy(void)
4584{
4585        int i;
4586        struct diff_filepair *p;
4587        struct diff_queue_struct *q = &diff_queued_diff;
4588
4589        diff_debug_queue("resolve-rename-copy", q);
4590
4591        for (i = 0; i < q->nr; i++) {
4592                p = q->queue[i];
4593                p->status = 0; /* undecided */
4594                if (DIFF_PAIR_UNMERGED(p))
4595                        p->status = DIFF_STATUS_UNMERGED;
4596                else if (!DIFF_FILE_VALID(p->one))
4597                        p->status = DIFF_STATUS_ADDED;
4598                else if (!DIFF_FILE_VALID(p->two))
4599                        p->status = DIFF_STATUS_DELETED;
4600                else if (DIFF_PAIR_TYPE_CHANGED(p))
4601                        p->status = DIFF_STATUS_TYPE_CHANGED;
4602
4603                /* from this point on, we are dealing with a pair
4604                 * whose both sides are valid and of the same type, i.e.
4605                 * either in-place edit or rename/copy edit.
4606                 */
4607                else if (DIFF_PAIR_RENAME(p)) {
4608                        /*
4609                         * A rename might have re-connected a broken
4610                         * pair up, causing the pathnames to be the
4611                         * same again. If so, that's not a rename at
4612                         * all, just a modification..
4613                         *
4614                         * Otherwise, see if this source was used for
4615                         * multiple renames, in which case we decrement
4616                         * the count, and call it a copy.
4617                         */
4618                        if (!strcmp(p->one->path, p->two->path))
4619                                p->status = DIFF_STATUS_MODIFIED;
4620                        else if (--p->one->rename_used > 0)
4621                                p->status = DIFF_STATUS_COPIED;
4622                        else
4623                                p->status = DIFF_STATUS_RENAMED;
4624                }
4625                else if (oidcmp(&p->one->oid, &p->two->oid) ||
4626                         p->one->mode != p->two->mode ||
4627                         p->one->dirty_submodule ||
4628                         p->two->dirty_submodule ||
4629                         is_null_oid(&p->one->oid))
4630                        p->status = DIFF_STATUS_MODIFIED;
4631                else {
4632                        /* This is a "no-change" entry and should not
4633                         * happen anymore, but prepare for broken callers.
4634                         */
4635                        error("feeding unmodified %s to diffcore",
4636                              p->one->path);
4637                        p->status = DIFF_STATUS_UNKNOWN;
4638                }
4639        }
4640        diff_debug_queue("resolve-rename-copy done", q);
4641}
4642
4643static int check_pair_status(struct diff_filepair *p)
4644{
4645        switch (p->status) {
4646        case DIFF_STATUS_UNKNOWN:
4647                return 0;
4648        case 0:
4649                die("internal error in diff-resolve-rename-copy");
4650        default:
4651                return 1;
4652        }
4653}
4654
4655static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4656{
4657        int fmt = opt->output_format;
4658
4659        if (fmt & DIFF_FORMAT_CHECKDIFF)
4660                diff_flush_checkdiff(p, opt);
4661        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4662                diff_flush_raw(p, opt);
4663        else if (fmt & DIFF_FORMAT_NAME) {
4664                const char *name_a, *name_b;
4665                name_a = p->two->path;
4666                name_b = NULL;
4667                strip_prefix(opt->prefix_length, &name_a, &name_b);
4668                fprintf(opt->file, "%s", diff_line_prefix(opt));
4669                write_name_quoted(name_a, opt->file, opt->line_termination);
4670        }
4671}
4672
4673static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4674{
4675        if (fs->mode)
4676                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4677        else
4678                fprintf(file, " %s ", newdelete);
4679        write_name_quoted(fs->path, file, '\n');
4680}
4681
4682
4683static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4684                const char *line_prefix)
4685{
4686        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4687                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4688                        p->two->mode, show_name ? ' ' : '\n');
4689                if (show_name) {
4690                        write_name_quoted(p->two->path, file, '\n');
4691                }
4692        }
4693}
4694
4695static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4696                        const char *line_prefix)
4697{
4698        char *names = pprint_rename(p->one->path, p->two->path);
4699
4700        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4701        free(names);
4702        show_mode_change(file, p, 0, line_prefix);
4703}
4704
4705static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4706{
4707        FILE *file = opt->file;
4708        const char *line_prefix = diff_line_prefix(opt);
4709
4710        switch(p->status) {
4711        case DIFF_STATUS_DELETED:
4712                fputs(line_prefix, file);
4713                show_file_mode_name(file, "delete", p->one);
4714                break;
4715        case DIFF_STATUS_ADDED:
4716                fputs(line_prefix, file);
4717                show_file_mode_name(file, "create", p->two);
4718                break;
4719        case DIFF_STATUS_COPIED:
4720                fputs(line_prefix, file);
4721                show_rename_copy(file, "copy", p, line_prefix);
4722                break;
4723        case DIFF_STATUS_RENAMED:
4724                fputs(line_prefix, file);
4725                show_rename_copy(file, "rename", p, line_prefix);
4726                break;
4727        default:
4728                if (p->score) {
4729                        fprintf(file, "%s rewrite ", line_prefix);
4730                        write_name_quoted(p->two->path, file, ' ');
4731                        fprintf(file, "(%d%%)\n", similarity_index(p));
4732                }
4733                show_mode_change(file, p, !p->score, line_prefix);
4734                break;
4735        }
4736}
4737
4738struct patch_id_t {
4739        git_SHA_CTX *ctx;
4740        int patchlen;
4741};
4742
4743static int remove_space(char *line, int len)
4744{
4745        int i;
4746        char *dst = line;
4747        unsigned char c;
4748
4749        for (i = 0; i < len; i++)
4750                if (!isspace((c = line[i])))
4751                        *dst++ = c;
4752
4753        return dst - line;
4754}
4755
4756static void patch_id_consume(void *priv, char *line, unsigned long len)
4757{
4758        struct patch_id_t *data = priv;
4759        int new_len;
4760
4761        /* Ignore line numbers when computing the SHA1 of the patch */
4762        if (starts_with(line, "@@ -"))
4763                return;
4764
4765        new_len = remove_space(line, len);
4766
4767        git_SHA1_Update(data->ctx, line, new_len);
4768        data->patchlen += new_len;
4769}
4770
4771static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
4772{
4773        git_SHA1_Update(ctx, str, strlen(str));
4774}
4775
4776static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
4777{
4778        /* large enough for 2^32 in octal */
4779        char buf[12];
4780        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
4781        git_SHA1_Update(ctx, buf, len);
4782}
4783
4784/* returns 0 upon success, and writes result into sha1 */
4785static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
4786{
4787        struct diff_queue_struct *q = &diff_queued_diff;
4788        int i;
4789        git_SHA_CTX ctx;
4790        struct patch_id_t data;
4791
4792        git_SHA1_Init(&ctx);
4793        memset(&data, 0, sizeof(struct patch_id_t));
4794        data.ctx = &ctx;
4795
4796        for (i = 0; i < q->nr; i++) {
4797                xpparam_t xpp;
4798                xdemitconf_t xecfg;
4799                mmfile_t mf1, mf2;
4800                struct diff_filepair *p = q->queue[i];
4801                int len1, len2;
4802
4803                memset(&xpp, 0, sizeof(xpp));
4804                memset(&xecfg, 0, sizeof(xecfg));
4805                if (p->status == 0)
4806                        return error("internal diff status error");
4807                if (p->status == DIFF_STATUS_UNKNOWN)
4808                        continue;
4809                if (diff_unmodified_pair(p))
4810                        continue;
4811                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4812                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4813                        continue;
4814                if (DIFF_PAIR_UNMERGED(p))
4815                        continue;
4816
4817                diff_fill_oid_info(p->one);
4818                diff_fill_oid_info(p->two);
4819
4820                len1 = remove_space(p->one->path, strlen(p->one->path));
4821                len2 = remove_space(p->two->path, strlen(p->two->path));
4822                patch_id_add_string(&ctx, "diff--git");
4823                patch_id_add_string(&ctx, "a/");
4824                git_SHA1_Update(&ctx, p->one->path, len1);
4825                patch_id_add_string(&ctx, "b/");
4826                git_SHA1_Update(&ctx, p->two->path, len2);
4827
4828                if (p->one->mode == 0) {
4829                        patch_id_add_string(&ctx, "newfilemode");
4830                        patch_id_add_mode(&ctx, p->two->mode);
4831                        patch_id_add_string(&ctx, "---/dev/null");
4832                        patch_id_add_string(&ctx, "+++b/");
4833                        git_SHA1_Update(&ctx, p->two->path, len2);
4834                } else if (p->two->mode == 0) {
4835                        patch_id_add_string(&ctx, "deletedfilemode");
4836                        patch_id_add_mode(&ctx, p->one->mode);
4837                        patch_id_add_string(&ctx, "---a/");
4838                        git_SHA1_Update(&ctx, p->one->path, len1);
4839                        patch_id_add_string(&ctx, "+++/dev/null");
4840                } else {
4841                        patch_id_add_string(&ctx, "---a/");
4842                        git_SHA1_Update(&ctx, p->one->path, len1);
4843                        patch_id_add_string(&ctx, "+++b/");
4844                        git_SHA1_Update(&ctx, p->two->path, len2);
4845                }
4846
4847                if (diff_header_only)
4848                        continue;
4849
4850                if (fill_mmfile(&mf1, p->one) < 0 ||
4851                    fill_mmfile(&mf2, p->two) < 0)
4852                        return error("unable to read files to diff");
4853
4854                if (diff_filespec_is_binary(p->one) ||
4855                    diff_filespec_is_binary(p->two)) {
4856                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
4857                                        GIT_SHA1_HEXSZ);
4858                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
4859                                        GIT_SHA1_HEXSZ);
4860                        continue;
4861                }
4862
4863                xpp.flags = 0;
4864                xecfg.ctxlen = 3;
4865                xecfg.flags = 0;
4866                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4867                                  &xpp, &xecfg))
4868                        return error("unable to generate patch-id diff for %s",
4869                                     p->one->path);
4870        }
4871
4872        git_SHA1_Final(oid->hash, &ctx);
4873        return 0;
4874}
4875
4876int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
4877{
4878        struct diff_queue_struct *q = &diff_queued_diff;
4879        int i;
4880        int result = diff_get_patch_id(options, oid, diff_header_only);
4881
4882        for (i = 0; i < q->nr; i++)
4883                diff_free_filepair(q->queue[i]);
4884
4885        free(q->queue);
4886        DIFF_QUEUE_CLEAR(q);
4887
4888        return result;
4889}
4890
4891static int is_summary_empty(const struct diff_queue_struct *q)
4892{
4893        int i;
4894
4895        for (i = 0; i < q->nr; i++) {
4896                const struct diff_filepair *p = q->queue[i];
4897
4898                switch (p->status) {
4899                case DIFF_STATUS_DELETED:
4900                case DIFF_STATUS_ADDED:
4901                case DIFF_STATUS_COPIED:
4902                case DIFF_STATUS_RENAMED:
4903                        return 0;
4904                default:
4905                        if (p->score)
4906                                return 0;
4907                        if (p->one->mode && p->two->mode &&
4908                            p->one->mode != p->two->mode)
4909                                return 0;
4910                        break;
4911                }
4912        }
4913        return 1;
4914}
4915
4916static const char rename_limit_warning[] =
4917N_("inexact rename detection was skipped due to too many files.");
4918
4919static const char degrade_cc_to_c_warning[] =
4920N_("only found copies from modified paths due to too many files.");
4921
4922static const char rename_limit_advice[] =
4923N_("you may want to set your %s variable to at least "
4924   "%d and retry the command.");
4925
4926void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4927{
4928        if (degraded_cc)
4929                warning(_(degrade_cc_to_c_warning));
4930        else if (needed)
4931                warning(_(rename_limit_warning));
4932        else
4933                return;
4934        if (0 < needed && needed < 32767)
4935                warning(_(rename_limit_advice), varname, needed);
4936}
4937
4938static void diff_flush_patch_all_file_pairs(struct diff_options *o)
4939{
4940        int i;
4941        struct diff_queue_struct *q = &diff_queued_diff;
4942
4943        if (WSEH_NEW & WS_RULE_MASK)
4944                die("BUG: WS rules bit mask overlaps with diff symbol flags");
4945
4946        for (i = 0; i < q->nr; i++) {
4947                struct diff_filepair *p = q->queue[i];
4948                if (check_pair_status(p))
4949                        diff_flush_patch(p, o);
4950        }
4951}
4952
4953void diff_flush(struct diff_options *options)
4954{
4955        struct diff_queue_struct *q = &diff_queued_diff;
4956        int i, output_format = options->output_format;
4957        int separator = 0;
4958        int dirstat_by_line = 0;
4959
4960        /*
4961         * Order: raw, stat, summary, patch
4962         * or:    name/name-status/checkdiff (other bits clear)
4963         */
4964        if (!q->nr)
4965                goto free_queue;
4966
4967        if (output_format & (DIFF_FORMAT_RAW |
4968                             DIFF_FORMAT_NAME |
4969                             DIFF_FORMAT_NAME_STATUS |
4970                             DIFF_FORMAT_CHECKDIFF)) {
4971                for (i = 0; i < q->nr; i++) {
4972                        struct diff_filepair *p = q->queue[i];
4973                        if (check_pair_status(p))
4974                                flush_one_pair(p, options);
4975                }
4976                separator++;
4977        }
4978
4979        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4980                dirstat_by_line = 1;
4981
4982        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4983            dirstat_by_line) {
4984                struct diffstat_t diffstat;
4985
4986                memset(&diffstat, 0, sizeof(struct diffstat_t));
4987                for (i = 0; i < q->nr; i++) {
4988                        struct diff_filepair *p = q->queue[i];
4989                        if (check_pair_status(p))
4990                                diff_flush_stat(p, options, &diffstat);
4991                }
4992                if (output_format & DIFF_FORMAT_NUMSTAT)
4993                        show_numstat(&diffstat, options);
4994                if (output_format & DIFF_FORMAT_DIFFSTAT)
4995                        show_stats(&diffstat, options);
4996                if (output_format & DIFF_FORMAT_SHORTSTAT)
4997                        show_shortstats(&diffstat, options);
4998                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
4999                        show_dirstat_by_line(&diffstat, options);
5000                free_diffstat_info(&diffstat);
5001                separator++;
5002        }
5003        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5004                show_dirstat(options);
5005
5006        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5007                for (i = 0; i < q->nr; i++) {
5008                        diff_summary(options, q->queue[i]);
5009                }
5010                separator++;
5011        }
5012
5013        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5014            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
5015            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
5016                /*
5017                 * run diff_flush_patch for the exit status. setting
5018                 * options->file to /dev/null should be safe, because we
5019                 * aren't supposed to produce any output anyway.
5020                 */
5021                if (options->close_file)
5022                        fclose(options->file);
5023                options->file = xfopen("/dev/null", "w");
5024                options->close_file = 1;
5025                for (i = 0; i < q->nr; i++) {
5026                        struct diff_filepair *p = q->queue[i];
5027                        if (check_pair_status(p))
5028                                diff_flush_patch(p, options);
5029                        if (options->found_changes)
5030                                break;
5031                }
5032        }
5033
5034        if (output_format & DIFF_FORMAT_PATCH) {
5035                if (separator) {
5036                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5037                        if (options->stat_sep) {
5038                                /* attach patch instead of inline */
5039                                fputs(options->stat_sep, options->file);
5040                        }
5041                }
5042
5043                diff_flush_patch_all_file_pairs(options);
5044        }
5045
5046        if (output_format & DIFF_FORMAT_CALLBACK)
5047                options->format_callback(q, options, options->format_callback_data);
5048
5049        for (i = 0; i < q->nr; i++)
5050                diff_free_filepair(q->queue[i]);
5051free_queue:
5052        free(q->queue);
5053        DIFF_QUEUE_CLEAR(q);
5054        if (options->close_file)
5055                fclose(options->file);
5056
5057        /*
5058         * Report the content-level differences with HAS_CHANGES;
5059         * diff_addremove/diff_change does not set the bit when
5060         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5061         */
5062        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
5063                if (options->found_changes)
5064                        DIFF_OPT_SET(options, HAS_CHANGES);
5065                else
5066                        DIFF_OPT_CLR(options, HAS_CHANGES);
5067        }
5068}
5069
5070static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5071{
5072        return (((p->status == DIFF_STATUS_MODIFIED) &&
5073                 ((p->score &&
5074                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5075                  (!p->score &&
5076                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5077                ((p->status != DIFF_STATUS_MODIFIED) &&
5078                 filter_bit_tst(p->status, options)));
5079}
5080
5081static void diffcore_apply_filter(struct diff_options *options)
5082{
5083        int i;
5084        struct diff_queue_struct *q = &diff_queued_diff;
5085        struct diff_queue_struct outq;
5086
5087        DIFF_QUEUE_CLEAR(&outq);
5088
5089        if (!options->filter)
5090                return;
5091
5092        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
5093                int found;
5094                for (i = found = 0; !found && i < q->nr; i++) {
5095                        if (match_filter(options, q->queue[i]))
5096                                found++;
5097                }
5098                if (found)
5099                        return;
5100
5101                /* otherwise we will clear the whole queue
5102                 * by copying the empty outq at the end of this
5103                 * function, but first clear the current entries
5104                 * in the queue.
5105                 */
5106                for (i = 0; i < q->nr; i++)
5107                        diff_free_filepair(q->queue[i]);
5108        }
5109        else {
5110                /* Only the matching ones */
5111                for (i = 0; i < q->nr; i++) {
5112                        struct diff_filepair *p = q->queue[i];
5113                        if (match_filter(options, p))
5114                                diff_q(&outq, p);
5115                        else
5116                                diff_free_filepair(p);
5117                }
5118        }
5119        free(q->queue);
5120        *q = outq;
5121}
5122
5123/* Check whether two filespecs with the same mode and size are identical */
5124static int diff_filespec_is_identical(struct diff_filespec *one,
5125                                      struct diff_filespec *two)
5126{
5127        if (S_ISGITLINK(one->mode))
5128                return 0;
5129        if (diff_populate_filespec(one, 0))
5130                return 0;
5131        if (diff_populate_filespec(two, 0))
5132                return 0;
5133        return !memcmp(one->data, two->data, one->size);
5134}
5135
5136static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
5137{
5138        if (p->done_skip_stat_unmatch)
5139                return p->skip_stat_unmatch_result;
5140
5141        p->done_skip_stat_unmatch = 1;
5142        p->skip_stat_unmatch_result = 0;
5143        /*
5144         * 1. Entries that come from stat info dirtiness
5145         *    always have both sides (iow, not create/delete),
5146         *    one side of the object name is unknown, with
5147         *    the same mode and size.  Keep the ones that
5148         *    do not match these criteria.  They have real
5149         *    differences.
5150         *
5151         * 2. At this point, the file is known to be modified,
5152         *    with the same mode and size, and the object
5153         *    name of one side is unknown.  Need to inspect
5154         *    the identical contents.
5155         */
5156        if (!DIFF_FILE_VALID(p->one) || /* (1) */
5157            !DIFF_FILE_VALID(p->two) ||
5158            (p->one->oid_valid && p->two->oid_valid) ||
5159            (p->one->mode != p->two->mode) ||
5160            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
5161            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
5162            (p->one->size != p->two->size) ||
5163            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
5164                p->skip_stat_unmatch_result = 1;
5165        return p->skip_stat_unmatch_result;
5166}
5167
5168static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
5169{
5170        int i;
5171        struct diff_queue_struct *q = &diff_queued_diff;
5172        struct diff_queue_struct outq;
5173        DIFF_QUEUE_CLEAR(&outq);
5174
5175        for (i = 0; i < q->nr; i++) {
5176                struct diff_filepair *p = q->queue[i];
5177
5178                if (diff_filespec_check_stat_unmatch(p))
5179                        diff_q(&outq, p);
5180                else {
5181                        /*
5182                         * The caller can subtract 1 from skip_stat_unmatch
5183                         * to determine how many paths were dirty only
5184                         * due to stat info mismatch.
5185                         */
5186                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
5187                                diffopt->skip_stat_unmatch++;
5188                        diff_free_filepair(p);
5189                }
5190        }
5191        free(q->queue);
5192        *q = outq;
5193}
5194
5195static int diffnamecmp(const void *a_, const void *b_)
5196{
5197        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
5198        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
5199        const char *name_a, *name_b;
5200
5201        name_a = a->one ? a->one->path : a->two->path;
5202        name_b = b->one ? b->one->path : b->two->path;
5203        return strcmp(name_a, name_b);
5204}
5205
5206void diffcore_fix_diff_index(struct diff_options *options)
5207{
5208        struct diff_queue_struct *q = &diff_queued_diff;
5209        QSORT(q->queue, q->nr, diffnamecmp);
5210}
5211
5212void diffcore_std(struct diff_options *options)
5213{
5214        /* NOTE please keep the following in sync with diff_tree_combined() */
5215        if (options->skip_stat_unmatch)
5216                diffcore_skip_stat_unmatch(options);
5217        if (!options->found_follow) {
5218                /* See try_to_follow_renames() in tree-diff.c */
5219                if (options->break_opt != -1)
5220                        diffcore_break(options->break_opt);
5221                if (options->detect_rename)
5222                        diffcore_rename(options);
5223                if (options->break_opt != -1)
5224                        diffcore_merge_broken();
5225        }
5226        if (options->pickaxe)
5227                diffcore_pickaxe(options);
5228        if (options->orderfile)
5229                diffcore_order(options->orderfile);
5230        if (!options->found_follow)
5231                /* See try_to_follow_renames() in tree-diff.c */
5232                diff_resolve_rename_copy();
5233        diffcore_apply_filter(options);
5234
5235        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5236                DIFF_OPT_SET(options, HAS_CHANGES);
5237        else
5238                DIFF_OPT_CLR(options, HAS_CHANGES);
5239
5240        options->found_follow = 0;
5241}
5242
5243int diff_result_code(struct diff_options *opt, int status)
5244{
5245        int result = 0;
5246
5247        diff_warn_rename_limit("diff.renameLimit",
5248                               opt->needed_rename_limit,
5249                               opt->degraded_cc_to_c);
5250        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5251            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
5252                return status;
5253        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5254            DIFF_OPT_TST(opt, HAS_CHANGES))
5255                result |= 01;
5256        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
5257            DIFF_OPT_TST(opt, CHECK_FAILED))
5258                result |= 02;
5259        return result;
5260}
5261
5262int diff_can_quit_early(struct diff_options *opt)
5263{
5264        return (DIFF_OPT_TST(opt, QUICK) &&
5265                !opt->filter &&
5266                DIFF_OPT_TST(opt, HAS_CHANGES));
5267}
5268
5269/*
5270 * Shall changes to this submodule be ignored?
5271 *
5272 * Submodule changes can be configured to be ignored separately for each path,
5273 * but that configuration can be overridden from the command line.
5274 */
5275static int is_submodule_ignored(const char *path, struct diff_options *options)
5276{
5277        int ignored = 0;
5278        unsigned orig_flags = options->flags;
5279        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
5280                set_diffopt_flags_from_submodule_config(options, path);
5281        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
5282                ignored = 1;
5283        options->flags = orig_flags;
5284        return ignored;
5285}
5286
5287void diff_addremove(struct diff_options *options,
5288                    int addremove, unsigned mode,
5289                    const struct object_id *oid,
5290                    int oid_valid,
5291                    const char *concatpath, unsigned dirty_submodule)
5292{
5293        struct diff_filespec *one, *two;
5294
5295        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
5296                return;
5297
5298        /* This may look odd, but it is a preparation for
5299         * feeding "there are unchanged files which should
5300         * not produce diffs, but when you are doing copy
5301         * detection you would need them, so here they are"
5302         * entries to the diff-core.  They will be prefixed
5303         * with something like '=' or '*' (I haven't decided
5304         * which but should not make any difference).
5305         * Feeding the same new and old to diff_change()
5306         * also has the same effect.
5307         * Before the final output happens, they are pruned after
5308         * merged into rename/copy pairs as appropriate.
5309         */
5310        if (DIFF_OPT_TST(options, REVERSE_DIFF))
5311                addremove = (addremove == '+' ? '-' :
5312                             addremove == '-' ? '+' : addremove);
5313
5314        if (options->prefix &&
5315            strncmp(concatpath, options->prefix, options->prefix_length))
5316                return;
5317
5318        one = alloc_filespec(concatpath);
5319        two = alloc_filespec(concatpath);
5320
5321        if (addremove != '+')
5322                fill_filespec(one, oid, oid_valid, mode);
5323        if (addremove != '-') {
5324                fill_filespec(two, oid, oid_valid, mode);
5325                two->dirty_submodule = dirty_submodule;
5326        }
5327
5328        diff_queue(&diff_queued_diff, one, two);
5329        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5330                DIFF_OPT_SET(options, HAS_CHANGES);
5331}
5332
5333void diff_change(struct diff_options *options,
5334                 unsigned old_mode, unsigned new_mode,
5335                 const struct object_id *old_oid,
5336                 const struct object_id *new_oid,
5337                 int old_oid_valid, int new_oid_valid,
5338                 const char *concatpath,
5339                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
5340{
5341        struct diff_filespec *one, *two;
5342        struct diff_filepair *p;
5343
5344        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
5345            is_submodule_ignored(concatpath, options))
5346                return;
5347
5348        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
5349                SWAP(old_mode, new_mode);
5350                SWAP(old_oid, new_oid);
5351                SWAP(old_oid_valid, new_oid_valid);
5352                SWAP(old_dirty_submodule, new_dirty_submodule);
5353        }
5354
5355        if (options->prefix &&
5356            strncmp(concatpath, options->prefix, options->prefix_length))
5357                return;
5358
5359        one = alloc_filespec(concatpath);
5360        two = alloc_filespec(concatpath);
5361        fill_filespec(one, old_oid, old_oid_valid, old_mode);
5362        fill_filespec(two, new_oid, new_oid_valid, new_mode);
5363        one->dirty_submodule = old_dirty_submodule;
5364        two->dirty_submodule = new_dirty_submodule;
5365        p = diff_queue(&diff_queued_diff, one, two);
5366
5367        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5368                return;
5369
5370        if (DIFF_OPT_TST(options, QUICK) && options->skip_stat_unmatch &&
5371            !diff_filespec_check_stat_unmatch(p))
5372                return;
5373
5374        DIFF_OPT_SET(options, HAS_CHANGES);
5375}
5376
5377struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
5378{
5379        struct diff_filepair *pair;
5380        struct diff_filespec *one, *two;
5381
5382        if (options->prefix &&
5383            strncmp(path, options->prefix, options->prefix_length))
5384                return NULL;
5385
5386        one = alloc_filespec(path);
5387        two = alloc_filespec(path);
5388        pair = diff_queue(&diff_queued_diff, one, two);
5389        pair->is_unmerged = 1;
5390        return pair;
5391}
5392
5393static char *run_textconv(const char *pgm, struct diff_filespec *spec,
5394                size_t *outsize)
5395{
5396        struct diff_tempfile *temp;
5397        const char *argv[3];
5398        const char **arg = argv;
5399        struct child_process child = CHILD_PROCESS_INIT;
5400        struct strbuf buf = STRBUF_INIT;
5401        int err = 0;
5402
5403        temp = prepare_temp_file(spec->path, spec);
5404        *arg++ = pgm;
5405        *arg++ = temp->name;
5406        *arg = NULL;
5407
5408        child.use_shell = 1;
5409        child.argv = argv;
5410        child.out = -1;
5411        if (start_command(&child)) {
5412                remove_tempfile();
5413                return NULL;
5414        }
5415
5416        if (strbuf_read(&buf, child.out, 0) < 0)
5417                err = error("error reading from textconv command '%s'", pgm);
5418        close(child.out);
5419
5420        if (finish_command(&child) || err) {
5421                strbuf_release(&buf);
5422                remove_tempfile();
5423                return NULL;
5424        }
5425        remove_tempfile();
5426
5427        return strbuf_detach(&buf, outsize);
5428}
5429
5430size_t fill_textconv(struct userdiff_driver *driver,
5431                     struct diff_filespec *df,
5432                     char **outbuf)
5433{
5434        size_t size;
5435
5436        if (!driver) {
5437                if (!DIFF_FILE_VALID(df)) {
5438                        *outbuf = "";
5439                        return 0;
5440                }
5441                if (diff_populate_filespec(df, 0))
5442                        die("unable to read files to diff");
5443                *outbuf = df->data;
5444                return df->size;
5445        }
5446
5447        if (!driver->textconv)
5448                die("BUG: fill_textconv called with non-textconv driver");
5449
5450        if (driver->textconv_cache && df->oid_valid) {
5451                *outbuf = notes_cache_get(driver->textconv_cache,
5452                                          &df->oid,
5453                                          &size);
5454                if (*outbuf)
5455                        return size;
5456        }
5457
5458        *outbuf = run_textconv(driver->textconv, df, &size);
5459        if (!*outbuf)
5460                die("unable to read files to diff");
5461
5462        if (driver->textconv_cache && df->oid_valid) {
5463                /* ignore errors, as we might be in a readonly repository */
5464                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
5465                                size);
5466                /*
5467                 * we could save up changes and flush them all at the end,
5468                 * but we would need an extra call after all diffing is done.
5469                 * Since generating a cache entry is the slow path anyway,
5470                 * this extra overhead probably isn't a big deal.
5471                 */
5472                notes_cache_write(driver->textconv_cache);
5473        }
5474
5475        return size;
5476}
5477
5478int textconv_object(const char *path,
5479                    unsigned mode,
5480                    const struct object_id *oid,
5481                    int oid_valid,
5482                    char **buf,
5483                    unsigned long *buf_size)
5484{
5485        struct diff_filespec *df;
5486        struct userdiff_driver *textconv;
5487
5488        df = alloc_filespec(path);
5489        fill_filespec(df, oid, oid_valid, mode);
5490        textconv = get_textconv(df);
5491        if (!textconv) {
5492                free_filespec(df);
5493                return 0;
5494        }
5495
5496        *buf_size = fill_textconv(textconv, df, buf);
5497        free_filespec(df);
5498        return 1;
5499}
5500
5501void setup_diff_pager(struct diff_options *opt)
5502{
5503        /*
5504         * If the user asked for our exit code, then either they want --quiet
5505         * or --exit-code. We should definitely not bother with a pager in the
5506         * former case, as we will generate no output. Since we still properly
5507         * report our exit code even when a pager is run, we _could_ run a
5508         * pager with --exit-code. But since we have not done so historically,
5509         * and because it is easy to find people oneline advising "git diff
5510         * --exit-code" in hooks and other scripts, we do not do so.
5511         */
5512        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5513            check_pager_config("diff") != 0)
5514                setup_pager();
5515}