diff.con commit Merge branch 'es/blame-L-more' (118b9d5)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "delta.h"
   9#include "xdiff-interface.h"
  10#include "color.h"
  11#include "attr.h"
  12#include "run-command.h"
  13#include "utf8.h"
  14#include "userdiff.h"
  15#include "sigchain.h"
  16#include "submodule.h"
  17#include "ll-merge.h"
  18#include "string-list.h"
  19
  20#ifdef NO_FAST_WORKING_DIRECTORY
  21#define FAST_WORKING_DIRECTORY 0
  22#else
  23#define FAST_WORKING_DIRECTORY 1
  24#endif
  25
  26static int diff_detect_rename_default;
  27static int diff_rename_limit_default = 400;
  28static int diff_suppress_blank_empty;
  29static int diff_use_color_default = -1;
  30static int diff_context_default = 3;
  31static const char *diff_word_regex_cfg;
  32static const char *external_diff_cmd_cfg;
  33int diff_auto_refresh_index = 1;
  34static int diff_mnemonic_prefix;
  35static int diff_no_prefix;
  36static int diff_stat_graph_width;
  37static int diff_dirstat_permille_default = 30;
  38static struct diff_options default_diff_options;
  39static long diff_algorithm;
  40
  41static char diff_colors[][COLOR_MAXLEN] = {
  42        GIT_COLOR_RESET,
  43        GIT_COLOR_NORMAL,       /* PLAIN */
  44        GIT_COLOR_BOLD,         /* METAINFO */
  45        GIT_COLOR_CYAN,         /* FRAGINFO */
  46        GIT_COLOR_RED,          /* OLD */
  47        GIT_COLOR_GREEN,        /* NEW */
  48        GIT_COLOR_YELLOW,       /* COMMIT */
  49        GIT_COLOR_BG_RED,       /* WHITESPACE */
  50        GIT_COLOR_NORMAL,       /* FUNCINFO */
  51};
  52
  53static int parse_diff_color_slot(const char *var, int ofs)
  54{
  55        if (!strcasecmp(var+ofs, "plain"))
  56                return DIFF_PLAIN;
  57        if (!strcasecmp(var+ofs, "meta"))
  58                return DIFF_METAINFO;
  59        if (!strcasecmp(var+ofs, "frag"))
  60                return DIFF_FRAGINFO;
  61        if (!strcasecmp(var+ofs, "old"))
  62                return DIFF_FILE_OLD;
  63        if (!strcasecmp(var+ofs, "new"))
  64                return DIFF_FILE_NEW;
  65        if (!strcasecmp(var+ofs, "commit"))
  66                return DIFF_COMMIT;
  67        if (!strcasecmp(var+ofs, "whitespace"))
  68                return DIFF_WHITESPACE;
  69        if (!strcasecmp(var+ofs, "func"))
  70                return DIFF_FUNCINFO;
  71        return -1;
  72}
  73
  74static int parse_dirstat_params(struct diff_options *options, const char *params_string,
  75                                struct strbuf *errmsg)
  76{
  77        char *params_copy = xstrdup(params_string);
  78        struct string_list params = STRING_LIST_INIT_NODUP;
  79        int ret = 0;
  80        int i;
  81
  82        if (*params_copy)
  83                string_list_split_in_place(&params, params_copy, ',', -1);
  84        for (i = 0; i < params.nr; i++) {
  85                const char *p = params.items[i].string;
  86                if (!strcmp(p, "changes")) {
  87                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  88                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  89                } else if (!strcmp(p, "lines")) {
  90                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
  91                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  92                } else if (!strcmp(p, "files")) {
  93                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  94                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
  95                } else if (!strcmp(p, "noncumulative")) {
  96                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
  97                } else if (!strcmp(p, "cumulative")) {
  98                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
  99                } else if (isdigit(*p)) {
 100                        char *end;
 101                        int permille = strtoul(p, &end, 10) * 10;
 102                        if (*end == '.' && isdigit(*++end)) {
 103                                /* only use first digit */
 104                                permille += *end - '0';
 105                                /* .. and ignore any further digits */
 106                                while (isdigit(*++end))
 107                                        ; /* nothing */
 108                        }
 109                        if (!*end)
 110                                options->dirstat_permille = permille;
 111                        else {
 112                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 113                                            p);
 114                                ret++;
 115                        }
 116                } else {
 117                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 118                        ret++;
 119                }
 120
 121        }
 122        string_list_clear(&params, 0);
 123        free(params_copy);
 124        return ret;
 125}
 126
 127static int parse_submodule_params(struct diff_options *options, const char *value)
 128{
 129        if (!strcmp(value, "log"))
 130                DIFF_OPT_SET(options, SUBMODULE_LOG);
 131        else if (!strcmp(value, "short"))
 132                DIFF_OPT_CLR(options, SUBMODULE_LOG);
 133        else
 134                return -1;
 135        return 0;
 136}
 137
 138static int git_config_rename(const char *var, const char *value)
 139{
 140        if (!value)
 141                return DIFF_DETECT_RENAME;
 142        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 143                return  DIFF_DETECT_COPY;
 144        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 145}
 146
 147long parse_algorithm_value(const char *value)
 148{
 149        if (!value)
 150                return -1;
 151        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 152                return 0;
 153        else if (!strcasecmp(value, "minimal"))
 154                return XDF_NEED_MINIMAL;
 155        else if (!strcasecmp(value, "patience"))
 156                return XDF_PATIENCE_DIFF;
 157        else if (!strcasecmp(value, "histogram"))
 158                return XDF_HISTOGRAM_DIFF;
 159        return -1;
 160}
 161
 162/*
 163 * These are to give UI layer defaults.
 164 * The core-level commands such as git-diff-files should
 165 * never be affected by the setting of diff.renames
 166 * the user happens to have in the configuration file.
 167 */
 168int git_diff_ui_config(const char *var, const char *value, void *cb)
 169{
 170        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 171                diff_use_color_default = git_config_colorbool(var, value);
 172                return 0;
 173        }
 174        if (!strcmp(var, "diff.context")) {
 175                diff_context_default = git_config_int(var, value);
 176                if (diff_context_default < 0)
 177                        return -1;
 178                return 0;
 179        }
 180        if (!strcmp(var, "diff.renames")) {
 181                diff_detect_rename_default = git_config_rename(var, value);
 182                return 0;
 183        }
 184        if (!strcmp(var, "diff.autorefreshindex")) {
 185                diff_auto_refresh_index = git_config_bool(var, value);
 186                return 0;
 187        }
 188        if (!strcmp(var, "diff.mnemonicprefix")) {
 189                diff_mnemonic_prefix = git_config_bool(var, value);
 190                return 0;
 191        }
 192        if (!strcmp(var, "diff.noprefix")) {
 193                diff_no_prefix = git_config_bool(var, value);
 194                return 0;
 195        }
 196        if (!strcmp(var, "diff.statgraphwidth")) {
 197                diff_stat_graph_width = git_config_int(var, value);
 198                return 0;
 199        }
 200        if (!strcmp(var, "diff.external"))
 201                return git_config_string(&external_diff_cmd_cfg, var, value);
 202        if (!strcmp(var, "diff.wordregex"))
 203                return git_config_string(&diff_word_regex_cfg, var, value);
 204
 205        if (!strcmp(var, "diff.ignoresubmodules"))
 206                handle_ignore_submodules_arg(&default_diff_options, value);
 207
 208        if (!strcmp(var, "diff.submodule")) {
 209                if (parse_submodule_params(&default_diff_options, value))
 210                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 211                                value);
 212                return 0;
 213        }
 214
 215        if (!strcmp(var, "diff.algorithm")) {
 216                diff_algorithm = parse_algorithm_value(value);
 217                if (diff_algorithm < 0)
 218                        return -1;
 219                return 0;
 220        }
 221
 222        if (git_color_config(var, value, cb) < 0)
 223                return -1;
 224
 225        return git_diff_basic_config(var, value, cb);
 226}
 227
 228int git_diff_basic_config(const char *var, const char *value, void *cb)
 229{
 230        if (!strcmp(var, "diff.renamelimit")) {
 231                diff_rename_limit_default = git_config_int(var, value);
 232                return 0;
 233        }
 234
 235        if (userdiff_config(var, value) < 0)
 236                return -1;
 237
 238        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 239                int slot = parse_diff_color_slot(var, 11);
 240                if (slot < 0)
 241                        return 0;
 242                if (!value)
 243                        return config_error_nonbool(var);
 244                color_parse(value, var, diff_colors[slot]);
 245                return 0;
 246        }
 247
 248        /* like GNU diff's --suppress-blank-empty option  */
 249        if (!strcmp(var, "diff.suppressblankempty") ||
 250                        /* for backwards compatibility */
 251                        !strcmp(var, "diff.suppress-blank-empty")) {
 252                diff_suppress_blank_empty = git_config_bool(var, value);
 253                return 0;
 254        }
 255
 256        if (!strcmp(var, "diff.dirstat")) {
 257                struct strbuf errmsg = STRBUF_INIT;
 258                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 259                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 260                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 261                                errmsg.buf);
 262                strbuf_release(&errmsg);
 263                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 264                return 0;
 265        }
 266
 267        if (!prefixcmp(var, "submodule."))
 268                return parse_submodule_config_option(var, value);
 269
 270        return git_default_config(var, value, cb);
 271}
 272
 273static char *quote_two(const char *one, const char *two)
 274{
 275        int need_one = quote_c_style(one, NULL, NULL, 1);
 276        int need_two = quote_c_style(two, NULL, NULL, 1);
 277        struct strbuf res = STRBUF_INIT;
 278
 279        if (need_one + need_two) {
 280                strbuf_addch(&res, '"');
 281                quote_c_style(one, &res, NULL, 1);
 282                quote_c_style(two, &res, NULL, 1);
 283                strbuf_addch(&res, '"');
 284        } else {
 285                strbuf_addstr(&res, one);
 286                strbuf_addstr(&res, two);
 287        }
 288        return strbuf_detach(&res, NULL);
 289}
 290
 291static const char *external_diff(void)
 292{
 293        static const char *external_diff_cmd = NULL;
 294        static int done_preparing = 0;
 295
 296        if (done_preparing)
 297                return external_diff_cmd;
 298        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 299        if (!external_diff_cmd)
 300                external_diff_cmd = external_diff_cmd_cfg;
 301        done_preparing = 1;
 302        return external_diff_cmd;
 303}
 304
 305static struct diff_tempfile {
 306        const char *name; /* filename external diff should read from */
 307        char hex[41];
 308        char mode[10];
 309        char tmp_path[PATH_MAX];
 310} diff_temp[2];
 311
 312typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 313
 314struct emit_callback {
 315        int color_diff;
 316        unsigned ws_rule;
 317        int blank_at_eof_in_preimage;
 318        int blank_at_eof_in_postimage;
 319        int lno_in_preimage;
 320        int lno_in_postimage;
 321        sane_truncate_fn truncate;
 322        const char **label_path;
 323        struct diff_words_data *diff_words;
 324        struct diff_options *opt;
 325        int *found_changesp;
 326        struct strbuf *header;
 327};
 328
 329static int count_lines(const char *data, int size)
 330{
 331        int count, ch, completely_empty = 1, nl_just_seen = 0;
 332        count = 0;
 333        while (0 < size--) {
 334                ch = *data++;
 335                if (ch == '\n') {
 336                        count++;
 337                        nl_just_seen = 1;
 338                        completely_empty = 0;
 339                }
 340                else {
 341                        nl_just_seen = 0;
 342                        completely_empty = 0;
 343                }
 344        }
 345        if (completely_empty)
 346                return 0;
 347        if (!nl_just_seen)
 348                count++; /* no trailing newline */
 349        return count;
 350}
 351
 352static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 353{
 354        if (!DIFF_FILE_VALID(one)) {
 355                mf->ptr = (char *)""; /* does not matter */
 356                mf->size = 0;
 357                return 0;
 358        }
 359        else if (diff_populate_filespec(one, 0))
 360                return -1;
 361
 362        mf->ptr = one->data;
 363        mf->size = one->size;
 364        return 0;
 365}
 366
 367/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 368static unsigned long diff_filespec_size(struct diff_filespec *one)
 369{
 370        if (!DIFF_FILE_VALID(one))
 371                return 0;
 372        diff_populate_filespec(one, 1);
 373        return one->size;
 374}
 375
 376static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 377{
 378        char *ptr = mf->ptr;
 379        long size = mf->size;
 380        int cnt = 0;
 381
 382        if (!size)
 383                return cnt;
 384        ptr += size - 1; /* pointing at the very end */
 385        if (*ptr != '\n')
 386                ; /* incomplete line */
 387        else
 388                ptr--; /* skip the last LF */
 389        while (mf->ptr < ptr) {
 390                char *prev_eol;
 391                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 392                        if (*prev_eol == '\n')
 393                                break;
 394                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 395                        break;
 396                cnt++;
 397                ptr = prev_eol - 1;
 398        }
 399        return cnt;
 400}
 401
 402static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 403                               struct emit_callback *ecbdata)
 404{
 405        int l1, l2, at;
 406        unsigned ws_rule = ecbdata->ws_rule;
 407        l1 = count_trailing_blank(mf1, ws_rule);
 408        l2 = count_trailing_blank(mf2, ws_rule);
 409        if (l2 <= l1) {
 410                ecbdata->blank_at_eof_in_preimage = 0;
 411                ecbdata->blank_at_eof_in_postimage = 0;
 412                return;
 413        }
 414        at = count_lines(mf1->ptr, mf1->size);
 415        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 416
 417        at = count_lines(mf2->ptr, mf2->size);
 418        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 419}
 420
 421static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 422                        int first, const char *line, int len)
 423{
 424        int has_trailing_newline, has_trailing_carriage_return;
 425        int nofirst;
 426        FILE *file = o->file;
 427
 428        fputs(diff_line_prefix(o), file);
 429
 430        if (len == 0) {
 431                has_trailing_newline = (first == '\n');
 432                has_trailing_carriage_return = (!has_trailing_newline &&
 433                                                (first == '\r'));
 434                nofirst = has_trailing_newline || has_trailing_carriage_return;
 435        } else {
 436                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 437                if (has_trailing_newline)
 438                        len--;
 439                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 440                if (has_trailing_carriage_return)
 441                        len--;
 442                nofirst = 0;
 443        }
 444
 445        if (len || !nofirst) {
 446                fputs(set, file);
 447                if (!nofirst)
 448                        fputc(first, file);
 449                fwrite(line, len, 1, file);
 450                fputs(reset, file);
 451        }
 452        if (has_trailing_carriage_return)
 453                fputc('\r', file);
 454        if (has_trailing_newline)
 455                fputc('\n', file);
 456}
 457
 458static void emit_line(struct diff_options *o, const char *set, const char *reset,
 459                      const char *line, int len)
 460{
 461        emit_line_0(o, set, reset, line[0], line+1, len-1);
 462}
 463
 464static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 465{
 466        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 467              ecbdata->blank_at_eof_in_preimage &&
 468              ecbdata->blank_at_eof_in_postimage &&
 469              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 470              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 471                return 0;
 472        return ws_blank_line(line, len, ecbdata->ws_rule);
 473}
 474
 475static void emit_add_line(const char *reset,
 476                          struct emit_callback *ecbdata,
 477                          const char *line, int len)
 478{
 479        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 480        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 481
 482        if (!*ws)
 483                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 484        else if (new_blank_line_at_eof(ecbdata, line, len))
 485                /* Blank line at EOF - paint '+' as well */
 486                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 487        else {
 488                /* Emit just the prefix, then the rest. */
 489                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 490                ws_check_emit(line, len, ecbdata->ws_rule,
 491                              ecbdata->opt->file, set, reset, ws);
 492        }
 493}
 494
 495static void emit_hunk_header(struct emit_callback *ecbdata,
 496                             const char *line, int len)
 497{
 498        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 499        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 500        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 501        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 502        static const char atat[2] = { '@', '@' };
 503        const char *cp, *ep;
 504        struct strbuf msgbuf = STRBUF_INIT;
 505        int org_len = len;
 506        int i = 1;
 507
 508        /*
 509         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 510         * it always is at least 10 bytes long.
 511         */
 512        if (len < 10 ||
 513            memcmp(line, atat, 2) ||
 514            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 515                emit_line(ecbdata->opt, plain, reset, line, len);
 516                return;
 517        }
 518        ep += 2; /* skip over @@ */
 519
 520        /* The hunk header in fraginfo color */
 521        strbuf_add(&msgbuf, frag, strlen(frag));
 522        strbuf_add(&msgbuf, line, ep - line);
 523        strbuf_add(&msgbuf, reset, strlen(reset));
 524
 525        /*
 526         * trailing "\r\n"
 527         */
 528        for ( ; i < 3; i++)
 529                if (line[len - i] == '\r' || line[len - i] == '\n')
 530                        len--;
 531
 532        /* blank before the func header */
 533        for (cp = ep; ep - line < len; ep++)
 534                if (*ep != ' ' && *ep != '\t')
 535                        break;
 536        if (ep != cp) {
 537                strbuf_add(&msgbuf, plain, strlen(plain));
 538                strbuf_add(&msgbuf, cp, ep - cp);
 539                strbuf_add(&msgbuf, reset, strlen(reset));
 540        }
 541
 542        if (ep < line + len) {
 543                strbuf_add(&msgbuf, func, strlen(func));
 544                strbuf_add(&msgbuf, ep, line + len - ep);
 545                strbuf_add(&msgbuf, reset, strlen(reset));
 546        }
 547
 548        strbuf_add(&msgbuf, line + len, org_len - len);
 549        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 550        strbuf_release(&msgbuf);
 551}
 552
 553static struct diff_tempfile *claim_diff_tempfile(void) {
 554        int i;
 555        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 556                if (!diff_temp[i].name)
 557                        return diff_temp + i;
 558        die("BUG: diff is failing to clean up its tempfiles");
 559}
 560
 561static int remove_tempfile_installed;
 562
 563static void remove_tempfile(void)
 564{
 565        int i;
 566        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 567                if (diff_temp[i].name == diff_temp[i].tmp_path)
 568                        unlink_or_warn(diff_temp[i].name);
 569                diff_temp[i].name = NULL;
 570        }
 571}
 572
 573static void remove_tempfile_on_signal(int signo)
 574{
 575        remove_tempfile();
 576        sigchain_pop(signo);
 577        raise(signo);
 578}
 579
 580static void print_line_count(FILE *file, int count)
 581{
 582        switch (count) {
 583        case 0:
 584                fprintf(file, "0,0");
 585                break;
 586        case 1:
 587                fprintf(file, "1");
 588                break;
 589        default:
 590                fprintf(file, "1,%d", count);
 591                break;
 592        }
 593}
 594
 595static void emit_rewrite_lines(struct emit_callback *ecb,
 596                               int prefix, const char *data, int size)
 597{
 598        const char *endp = NULL;
 599        static const char *nneof = " No newline at end of file\n";
 600        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 601        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 602
 603        while (0 < size) {
 604                int len;
 605
 606                endp = memchr(data, '\n', size);
 607                len = endp ? (endp - data + 1) : size;
 608                if (prefix != '+') {
 609                        ecb->lno_in_preimage++;
 610                        emit_line_0(ecb->opt, old, reset, '-',
 611                                    data, len);
 612                } else {
 613                        ecb->lno_in_postimage++;
 614                        emit_add_line(reset, ecb, data, len);
 615                }
 616                size -= len;
 617                data += len;
 618        }
 619        if (!endp) {
 620                const char *plain = diff_get_color(ecb->color_diff,
 621                                                   DIFF_PLAIN);
 622                putc('\n', ecb->opt->file);
 623                emit_line_0(ecb->opt, plain, reset, '\\',
 624                            nneof, strlen(nneof));
 625        }
 626}
 627
 628static void emit_rewrite_diff(const char *name_a,
 629                              const char *name_b,
 630                              struct diff_filespec *one,
 631                              struct diff_filespec *two,
 632                              struct userdiff_driver *textconv_one,
 633                              struct userdiff_driver *textconv_two,
 634                              struct diff_options *o)
 635{
 636        int lc_a, lc_b;
 637        const char *name_a_tab, *name_b_tab;
 638        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 639        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 640        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 641        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 642        const char *a_prefix, *b_prefix;
 643        char *data_one, *data_two;
 644        size_t size_one, size_two;
 645        struct emit_callback ecbdata;
 646        const char *line_prefix = diff_line_prefix(o);
 647
 648        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 649                a_prefix = o->b_prefix;
 650                b_prefix = o->a_prefix;
 651        } else {
 652                a_prefix = o->a_prefix;
 653                b_prefix = o->b_prefix;
 654        }
 655
 656        name_a += (*name_a == '/');
 657        name_b += (*name_b == '/');
 658        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 659        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 660
 661        strbuf_reset(&a_name);
 662        strbuf_reset(&b_name);
 663        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 664        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 665
 666        size_one = fill_textconv(textconv_one, one, &data_one);
 667        size_two = fill_textconv(textconv_two, two, &data_two);
 668
 669        memset(&ecbdata, 0, sizeof(ecbdata));
 670        ecbdata.color_diff = want_color(o->use_color);
 671        ecbdata.found_changesp = &o->found_changes;
 672        ecbdata.ws_rule = whitespace_rule(name_b);
 673        ecbdata.opt = o;
 674        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 675                mmfile_t mf1, mf2;
 676                mf1.ptr = (char *)data_one;
 677                mf2.ptr = (char *)data_two;
 678                mf1.size = size_one;
 679                mf2.size = size_two;
 680                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 681        }
 682        ecbdata.lno_in_preimage = 1;
 683        ecbdata.lno_in_postimage = 1;
 684
 685        lc_a = count_lines(data_one, size_one);
 686        lc_b = count_lines(data_two, size_two);
 687        fprintf(o->file,
 688                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 689                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 690                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 691                line_prefix, fraginfo);
 692        if (!o->irreversible_delete)
 693                print_line_count(o->file, lc_a);
 694        else
 695                fprintf(o->file, "?,?");
 696        fprintf(o->file, " +");
 697        print_line_count(o->file, lc_b);
 698        fprintf(o->file, " @@%s\n", reset);
 699        if (lc_a && !o->irreversible_delete)
 700                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 701        if (lc_b)
 702                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 703        if (textconv_one)
 704                free((char *)data_one);
 705        if (textconv_two)
 706                free((char *)data_two);
 707}
 708
 709struct diff_words_buffer {
 710        mmfile_t text;
 711        long alloc;
 712        struct diff_words_orig {
 713                const char *begin, *end;
 714        } *orig;
 715        int orig_nr, orig_alloc;
 716};
 717
 718static void diff_words_append(char *line, unsigned long len,
 719                struct diff_words_buffer *buffer)
 720{
 721        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 722        line++;
 723        len--;
 724        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 725        buffer->text.size += len;
 726        buffer->text.ptr[buffer->text.size] = '\0';
 727}
 728
 729struct diff_words_style_elem {
 730        const char *prefix;
 731        const char *suffix;
 732        const char *color; /* NULL; filled in by the setup code if
 733                            * color is enabled */
 734};
 735
 736struct diff_words_style {
 737        enum diff_words_type type;
 738        struct diff_words_style_elem new, old, ctx;
 739        const char *newline;
 740};
 741
 742static struct diff_words_style diff_words_styles[] = {
 743        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 744        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 745        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 746};
 747
 748struct diff_words_data {
 749        struct diff_words_buffer minus, plus;
 750        const char *current_plus;
 751        int last_minus;
 752        struct diff_options *opt;
 753        regex_t *word_regex;
 754        enum diff_words_type type;
 755        struct diff_words_style *style;
 756};
 757
 758static int fn_out_diff_words_write_helper(FILE *fp,
 759                                          struct diff_words_style_elem *st_el,
 760                                          const char *newline,
 761                                          size_t count, const char *buf,
 762                                          const char *line_prefix)
 763{
 764        int print = 0;
 765
 766        while (count) {
 767                char *p = memchr(buf, '\n', count);
 768                if (print)
 769                        fputs(line_prefix, fp);
 770                if (p != buf) {
 771                        if (st_el->color && fputs(st_el->color, fp) < 0)
 772                                return -1;
 773                        if (fputs(st_el->prefix, fp) < 0 ||
 774                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 775                            fputs(st_el->suffix, fp) < 0)
 776                                return -1;
 777                        if (st_el->color && *st_el->color
 778                            && fputs(GIT_COLOR_RESET, fp) < 0)
 779                                return -1;
 780                }
 781                if (!p)
 782                        return 0;
 783                if (fputs(newline, fp) < 0)
 784                        return -1;
 785                count -= p + 1 - buf;
 786                buf = p + 1;
 787                print = 1;
 788        }
 789        return 0;
 790}
 791
 792/*
 793 * '--color-words' algorithm can be described as:
 794 *
 795 *   1. collect a the minus/plus lines of a diff hunk, divided into
 796 *      minus-lines and plus-lines;
 797 *
 798 *   2. break both minus-lines and plus-lines into words and
 799 *      place them into two mmfile_t with one word for each line;
 800 *
 801 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 802 *
 803 * And for the common parts of the both file, we output the plus side text.
 804 * diff_words->current_plus is used to trace the current position of the plus file
 805 * which printed. diff_words->last_minus is used to trace the last minus word
 806 * printed.
 807 *
 808 * For '--graph' to work with '--color-words', we need to output the graph prefix
 809 * on each line of color words output. Generally, there are two conditions on
 810 * which we should output the prefix.
 811 *
 812 *   1. diff_words->last_minus == 0 &&
 813 *      diff_words->current_plus == diff_words->plus.text.ptr
 814 *
 815 *      that is: the plus text must start as a new line, and if there is no minus
 816 *      word printed, a graph prefix must be printed.
 817 *
 818 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 819 *      *(diff_words->current_plus - 1) == '\n'
 820 *
 821 *      that is: a graph prefix must be printed following a '\n'
 822 */
 823static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 824{
 825        if ((diff_words->last_minus == 0 &&
 826                diff_words->current_plus == diff_words->plus.text.ptr) ||
 827                (diff_words->current_plus > diff_words->plus.text.ptr &&
 828                *(diff_words->current_plus - 1) == '\n')) {
 829                return 1;
 830        } else {
 831                return 0;
 832        }
 833}
 834
 835static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 836{
 837        struct diff_words_data *diff_words = priv;
 838        struct diff_words_style *style = diff_words->style;
 839        int minus_first, minus_len, plus_first, plus_len;
 840        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 841        struct diff_options *opt = diff_words->opt;
 842        const char *line_prefix;
 843
 844        if (line[0] != '@' || parse_hunk_header(line, len,
 845                        &minus_first, &minus_len, &plus_first, &plus_len))
 846                return;
 847
 848        assert(opt);
 849        line_prefix = diff_line_prefix(opt);
 850
 851        /* POSIX requires that first be decremented by one if len == 0... */
 852        if (minus_len) {
 853                minus_begin = diff_words->minus.orig[minus_first].begin;
 854                minus_end =
 855                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 856        } else
 857                minus_begin = minus_end =
 858                        diff_words->minus.orig[minus_first].end;
 859
 860        if (plus_len) {
 861                plus_begin = diff_words->plus.orig[plus_first].begin;
 862                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 863        } else
 864                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 865
 866        if (color_words_output_graph_prefix(diff_words)) {
 867                fputs(line_prefix, diff_words->opt->file);
 868        }
 869        if (diff_words->current_plus != plus_begin) {
 870                fn_out_diff_words_write_helper(diff_words->opt->file,
 871                                &style->ctx, style->newline,
 872                                plus_begin - diff_words->current_plus,
 873                                diff_words->current_plus, line_prefix);
 874                if (*(plus_begin - 1) == '\n')
 875                        fputs(line_prefix, diff_words->opt->file);
 876        }
 877        if (minus_begin != minus_end) {
 878                fn_out_diff_words_write_helper(diff_words->opt->file,
 879                                &style->old, style->newline,
 880                                minus_end - minus_begin, minus_begin,
 881                                line_prefix);
 882        }
 883        if (plus_begin != plus_end) {
 884                fn_out_diff_words_write_helper(diff_words->opt->file,
 885                                &style->new, style->newline,
 886                                plus_end - plus_begin, plus_begin,
 887                                line_prefix);
 888        }
 889
 890        diff_words->current_plus = plus_end;
 891        diff_words->last_minus = minus_first;
 892}
 893
 894/* This function starts looking at *begin, and returns 0 iff a word was found. */
 895static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 896                int *begin, int *end)
 897{
 898        if (word_regex && *begin < buffer->size) {
 899                regmatch_t match[1];
 900                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 901                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 902                                        '\n', match[0].rm_eo - match[0].rm_so);
 903                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 904                        *begin += match[0].rm_so;
 905                        return *begin >= *end;
 906                }
 907                return -1;
 908        }
 909
 910        /* find the next word */
 911        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 912                (*begin)++;
 913        if (*begin >= buffer->size)
 914                return -1;
 915
 916        /* find the end of the word */
 917        *end = *begin + 1;
 918        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 919                (*end)++;
 920
 921        return 0;
 922}
 923
 924/*
 925 * This function splits the words in buffer->text, stores the list with
 926 * newline separator into out, and saves the offsets of the original words
 927 * in buffer->orig.
 928 */
 929static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 930                regex_t *word_regex)
 931{
 932        int i, j;
 933        long alloc = 0;
 934
 935        out->size = 0;
 936        out->ptr = NULL;
 937
 938        /* fake an empty "0th" word */
 939        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 940        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 941        buffer->orig_nr = 1;
 942
 943        for (i = 0; i < buffer->text.size; i++) {
 944                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 945                        return;
 946
 947                /* store original boundaries */
 948                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 949                                buffer->orig_alloc);
 950                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 951                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 952                buffer->orig_nr++;
 953
 954                /* store one word */
 955                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 956                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 957                out->ptr[out->size + j - i] = '\n';
 958                out->size += j - i + 1;
 959
 960                i = j - 1;
 961        }
 962}
 963
 964/* this executes the word diff on the accumulated buffers */
 965static void diff_words_show(struct diff_words_data *diff_words)
 966{
 967        xpparam_t xpp;
 968        xdemitconf_t xecfg;
 969        mmfile_t minus, plus;
 970        struct diff_words_style *style = diff_words->style;
 971
 972        struct diff_options *opt = diff_words->opt;
 973        const char *line_prefix;
 974
 975        assert(opt);
 976        line_prefix = diff_line_prefix(opt);
 977
 978        /* special case: only removal */
 979        if (!diff_words->plus.text.size) {
 980                fputs(line_prefix, diff_words->opt->file);
 981                fn_out_diff_words_write_helper(diff_words->opt->file,
 982                        &style->old, style->newline,
 983                        diff_words->minus.text.size,
 984                        diff_words->minus.text.ptr, line_prefix);
 985                diff_words->minus.text.size = 0;
 986                return;
 987        }
 988
 989        diff_words->current_plus = diff_words->plus.text.ptr;
 990        diff_words->last_minus = 0;
 991
 992        memset(&xpp, 0, sizeof(xpp));
 993        memset(&xecfg, 0, sizeof(xecfg));
 994        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 995        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 996        xpp.flags = 0;
 997        /* as only the hunk header will be parsed, we need a 0-context */
 998        xecfg.ctxlen = 0;
 999        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1000                      &xpp, &xecfg);
1001        free(minus.ptr);
1002        free(plus.ptr);
1003        if (diff_words->current_plus != diff_words->plus.text.ptr +
1004                        diff_words->plus.text.size) {
1005                if (color_words_output_graph_prefix(diff_words))
1006                        fputs(line_prefix, diff_words->opt->file);
1007                fn_out_diff_words_write_helper(diff_words->opt->file,
1008                        &style->ctx, style->newline,
1009                        diff_words->plus.text.ptr + diff_words->plus.text.size
1010                        - diff_words->current_plus, diff_words->current_plus,
1011                        line_prefix);
1012        }
1013        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1014}
1015
1016/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1017static void diff_words_flush(struct emit_callback *ecbdata)
1018{
1019        if (ecbdata->diff_words->minus.text.size ||
1020            ecbdata->diff_words->plus.text.size)
1021                diff_words_show(ecbdata->diff_words);
1022}
1023
1024static void diff_filespec_load_driver(struct diff_filespec *one)
1025{
1026        /* Use already-loaded driver */
1027        if (one->driver)
1028                return;
1029
1030        if (S_ISREG(one->mode))
1031                one->driver = userdiff_find_by_path(one->path);
1032
1033        /* Fallback to default settings */
1034        if (!one->driver)
1035                one->driver = userdiff_find_by_name("default");
1036}
1037
1038static const char *userdiff_word_regex(struct diff_filespec *one)
1039{
1040        diff_filespec_load_driver(one);
1041        return one->driver->word_regex;
1042}
1043
1044static void init_diff_words_data(struct emit_callback *ecbdata,
1045                                 struct diff_options *orig_opts,
1046                                 struct diff_filespec *one,
1047                                 struct diff_filespec *two)
1048{
1049        int i;
1050        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1051        memcpy(o, orig_opts, sizeof(struct diff_options));
1052
1053        ecbdata->diff_words =
1054                xcalloc(1, sizeof(struct diff_words_data));
1055        ecbdata->diff_words->type = o->word_diff;
1056        ecbdata->diff_words->opt = o;
1057        if (!o->word_regex)
1058                o->word_regex = userdiff_word_regex(one);
1059        if (!o->word_regex)
1060                o->word_regex = userdiff_word_regex(two);
1061        if (!o->word_regex)
1062                o->word_regex = diff_word_regex_cfg;
1063        if (o->word_regex) {
1064                ecbdata->diff_words->word_regex = (regex_t *)
1065                        xmalloc(sizeof(regex_t));
1066                if (regcomp(ecbdata->diff_words->word_regex,
1067                            o->word_regex,
1068                            REG_EXTENDED | REG_NEWLINE))
1069                        die ("Invalid regular expression: %s",
1070                             o->word_regex);
1071        }
1072        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1073                if (o->word_diff == diff_words_styles[i].type) {
1074                        ecbdata->diff_words->style =
1075                                &diff_words_styles[i];
1076                        break;
1077                }
1078        }
1079        if (want_color(o->use_color)) {
1080                struct diff_words_style *st = ecbdata->diff_words->style;
1081                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1082                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1083                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
1084        }
1085}
1086
1087static void free_diff_words_data(struct emit_callback *ecbdata)
1088{
1089        if (ecbdata->diff_words) {
1090                diff_words_flush(ecbdata);
1091                free (ecbdata->diff_words->opt);
1092                free (ecbdata->diff_words->minus.text.ptr);
1093                free (ecbdata->diff_words->minus.orig);
1094                free (ecbdata->diff_words->plus.text.ptr);
1095                free (ecbdata->diff_words->plus.orig);
1096                if (ecbdata->diff_words->word_regex) {
1097                        regfree(ecbdata->diff_words->word_regex);
1098                        free(ecbdata->diff_words->word_regex);
1099                }
1100                free(ecbdata->diff_words);
1101                ecbdata->diff_words = NULL;
1102        }
1103}
1104
1105const char *diff_get_color(int diff_use_color, enum color_diff ix)
1106{
1107        if (want_color(diff_use_color))
1108                return diff_colors[ix];
1109        return "";
1110}
1111
1112const char *diff_line_prefix(struct diff_options *opt)
1113{
1114        struct strbuf *msgbuf;
1115        if (!opt->output_prefix)
1116                return "";
1117
1118        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1119        return msgbuf->buf;
1120}
1121
1122static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1123{
1124        const char *cp;
1125        unsigned long allot;
1126        size_t l = len;
1127
1128        if (ecb->truncate)
1129                return ecb->truncate(line, len);
1130        cp = line;
1131        allot = l;
1132        while (0 < l) {
1133                (void) utf8_width(&cp, &l);
1134                if (!cp)
1135                        break; /* truncated in the middle? */
1136        }
1137        return allot - l;
1138}
1139
1140static void find_lno(const char *line, struct emit_callback *ecbdata)
1141{
1142        const char *p;
1143        ecbdata->lno_in_preimage = 0;
1144        ecbdata->lno_in_postimage = 0;
1145        p = strchr(line, '-');
1146        if (!p)
1147                return; /* cannot happen */
1148        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1149        p = strchr(p, '+');
1150        if (!p)
1151                return; /* cannot happen */
1152        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1153}
1154
1155static void fn_out_consume(void *priv, char *line, unsigned long len)
1156{
1157        struct emit_callback *ecbdata = priv;
1158        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1159        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1160        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1161        struct diff_options *o = ecbdata->opt;
1162        const char *line_prefix = diff_line_prefix(o);
1163
1164        if (ecbdata->header) {
1165                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1166                strbuf_reset(ecbdata->header);
1167                ecbdata->header = NULL;
1168        }
1169        *(ecbdata->found_changesp) = 1;
1170
1171        if (ecbdata->label_path[0]) {
1172                const char *name_a_tab, *name_b_tab;
1173
1174                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1175                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1176
1177                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1178                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1179                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1180                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1181                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1182        }
1183
1184        if (diff_suppress_blank_empty
1185            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1186                line[0] = '\n';
1187                len = 1;
1188        }
1189
1190        if (line[0] == '@') {
1191                if (ecbdata->diff_words)
1192                        diff_words_flush(ecbdata);
1193                len = sane_truncate_line(ecbdata, line, len);
1194                find_lno(line, ecbdata);
1195                emit_hunk_header(ecbdata, line, len);
1196                if (line[len-1] != '\n')
1197                        putc('\n', ecbdata->opt->file);
1198                return;
1199        }
1200
1201        if (len < 1) {
1202                emit_line(ecbdata->opt, reset, reset, line, len);
1203                if (ecbdata->diff_words
1204                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1205                        fputs("~\n", ecbdata->opt->file);
1206                return;
1207        }
1208
1209        if (ecbdata->diff_words) {
1210                if (line[0] == '-') {
1211                        diff_words_append(line, len,
1212                                          &ecbdata->diff_words->minus);
1213                        return;
1214                } else if (line[0] == '+') {
1215                        diff_words_append(line, len,
1216                                          &ecbdata->diff_words->plus);
1217                        return;
1218                } else if (!prefixcmp(line, "\\ ")) {
1219                        /*
1220                         * Eat the "no newline at eof" marker as if we
1221                         * saw a "+" or "-" line with nothing on it,
1222                         * and return without diff_words_flush() to
1223                         * defer processing. If this is the end of
1224                         * preimage, more "+" lines may come after it.
1225                         */
1226                        return;
1227                }
1228                diff_words_flush(ecbdata);
1229                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1230                        emit_line(ecbdata->opt, plain, reset, line, len);
1231                        fputs("~\n", ecbdata->opt->file);
1232                } else {
1233                        /*
1234                         * Skip the prefix character, if any.  With
1235                         * diff_suppress_blank_empty, there may be
1236                         * none.
1237                         */
1238                        if (line[0] != '\n') {
1239                              line++;
1240                              len--;
1241                        }
1242                        emit_line(ecbdata->opt, plain, reset, line, len);
1243                }
1244                return;
1245        }
1246
1247        if (line[0] != '+') {
1248                const char *color =
1249                        diff_get_color(ecbdata->color_diff,
1250                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1251                ecbdata->lno_in_preimage++;
1252                if (line[0] == ' ')
1253                        ecbdata->lno_in_postimage++;
1254                emit_line(ecbdata->opt, color, reset, line, len);
1255        } else {
1256                ecbdata->lno_in_postimage++;
1257                emit_add_line(reset, ecbdata, line + 1, len - 1);
1258        }
1259}
1260
1261static char *pprint_rename(const char *a, const char *b)
1262{
1263        const char *old = a;
1264        const char *new = b;
1265        struct strbuf name = STRBUF_INIT;
1266        int pfx_length, sfx_length;
1267        int pfx_adjust_for_slash;
1268        int len_a = strlen(a);
1269        int len_b = strlen(b);
1270        int a_midlen, b_midlen;
1271        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1272        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1273
1274        if (qlen_a || qlen_b) {
1275                quote_c_style(a, &name, NULL, 0);
1276                strbuf_addstr(&name, " => ");
1277                quote_c_style(b, &name, NULL, 0);
1278                return strbuf_detach(&name, NULL);
1279        }
1280
1281        /* Find common prefix */
1282        pfx_length = 0;
1283        while (*old && *new && *old == *new) {
1284                if (*old == '/')
1285                        pfx_length = old - a + 1;
1286                old++;
1287                new++;
1288        }
1289
1290        /* Find common suffix */
1291        old = a + len_a;
1292        new = b + len_b;
1293        sfx_length = 0;
1294        /*
1295         * If there is a common prefix, it must end in a slash.  In
1296         * that case we let this loop run 1 into the prefix to see the
1297         * same slash.
1298         *
1299         * If there is no common prefix, we cannot do this as it would
1300         * underrun the input strings.
1301         */
1302        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
1303        while (a + pfx_length - pfx_adjust_for_slash <= old &&
1304               b + pfx_length - pfx_adjust_for_slash <= new &&
1305               *old == *new) {
1306                if (*old == '/')
1307                        sfx_length = len_a - (old - a);
1308                old--;
1309                new--;
1310        }
1311
1312        /*
1313         * pfx{mid-a => mid-b}sfx
1314         * {pfx-a => pfx-b}sfx
1315         * pfx{sfx-a => sfx-b}
1316         * name-a => name-b
1317         */
1318        a_midlen = len_a - pfx_length - sfx_length;
1319        b_midlen = len_b - pfx_length - sfx_length;
1320        if (a_midlen < 0)
1321                a_midlen = 0;
1322        if (b_midlen < 0)
1323                b_midlen = 0;
1324
1325        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1326        if (pfx_length + sfx_length) {
1327                strbuf_add(&name, a, pfx_length);
1328                strbuf_addch(&name, '{');
1329        }
1330        strbuf_add(&name, a + pfx_length, a_midlen);
1331        strbuf_addstr(&name, " => ");
1332        strbuf_add(&name, b + pfx_length, b_midlen);
1333        if (pfx_length + sfx_length) {
1334                strbuf_addch(&name, '}');
1335                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1336        }
1337        return strbuf_detach(&name, NULL);
1338}
1339
1340struct diffstat_t {
1341        int nr;
1342        int alloc;
1343        struct diffstat_file {
1344                char *from_name;
1345                char *name;
1346                char *print_name;
1347                unsigned is_unmerged:1;
1348                unsigned is_binary:1;
1349                unsigned is_renamed:1;
1350                unsigned is_interesting:1;
1351                uintmax_t added, deleted;
1352        } **files;
1353};
1354
1355static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1356                                          const char *name_a,
1357                                          const char *name_b)
1358{
1359        struct diffstat_file *x;
1360        x = xcalloc(sizeof (*x), 1);
1361        if (diffstat->nr == diffstat->alloc) {
1362                diffstat->alloc = alloc_nr(diffstat->alloc);
1363                diffstat->files = xrealloc(diffstat->files,
1364                                diffstat->alloc * sizeof(x));
1365        }
1366        diffstat->files[diffstat->nr++] = x;
1367        if (name_b) {
1368                x->from_name = xstrdup(name_a);
1369                x->name = xstrdup(name_b);
1370                x->is_renamed = 1;
1371        }
1372        else {
1373                x->from_name = NULL;
1374                x->name = xstrdup(name_a);
1375        }
1376        return x;
1377}
1378
1379static void diffstat_consume(void *priv, char *line, unsigned long len)
1380{
1381        struct diffstat_t *diffstat = priv;
1382        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1383
1384        if (line[0] == '+')
1385                x->added++;
1386        else if (line[0] == '-')
1387                x->deleted++;
1388}
1389
1390const char mime_boundary_leader[] = "------------";
1391
1392static int scale_linear(int it, int width, int max_change)
1393{
1394        if (!it)
1395                return 0;
1396        /*
1397         * make sure that at least one '-' or '+' is printed if
1398         * there is any change to this path. The easiest way is to
1399         * scale linearly as if the alloted width is one column shorter
1400         * than it is, and then add 1 to the result.
1401         */
1402        return 1 + (it * (width - 1) / max_change);
1403}
1404
1405static void show_name(FILE *file,
1406                      const char *prefix, const char *name, int len)
1407{
1408        fprintf(file, " %s%-*s |", prefix, len, name);
1409}
1410
1411static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1412{
1413        if (cnt <= 0)
1414                return;
1415        fprintf(file, "%s", set);
1416        while (cnt--)
1417                putc(ch, file);
1418        fprintf(file, "%s", reset);
1419}
1420
1421static void fill_print_name(struct diffstat_file *file)
1422{
1423        char *pname;
1424
1425        if (file->print_name)
1426                return;
1427
1428        if (!file->is_renamed) {
1429                struct strbuf buf = STRBUF_INIT;
1430                if (quote_c_style(file->name, &buf, NULL, 0)) {
1431                        pname = strbuf_detach(&buf, NULL);
1432                } else {
1433                        pname = file->name;
1434                        strbuf_release(&buf);
1435                }
1436        } else {
1437                pname = pprint_rename(file->from_name, file->name);
1438        }
1439        file->print_name = pname;
1440}
1441
1442int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1443{
1444        struct strbuf sb = STRBUF_INIT;
1445        int ret;
1446
1447        if (!files) {
1448                assert(insertions == 0 && deletions == 0);
1449                return fprintf(fp, "%s\n", " 0 files changed");
1450        }
1451
1452        strbuf_addf(&sb,
1453                    (files == 1) ? " %d file changed" : " %d files changed",
1454                    files);
1455
1456        /*
1457         * For binary diff, the caller may want to print "x files
1458         * changed" with insertions == 0 && deletions == 0.
1459         *
1460         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1461         * is probably less confusing (i.e skip over "2 files changed
1462         * but nothing about added/removed lines? Is this a bug in Git?").
1463         */
1464        if (insertions || deletions == 0) {
1465                /*
1466                 * TRANSLATORS: "+" in (+) is a line addition marker;
1467                 * do not translate it.
1468                 */
1469                strbuf_addf(&sb,
1470                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
1471                            insertions);
1472        }
1473
1474        if (deletions || insertions == 0) {
1475                /*
1476                 * TRANSLATORS: "-" in (-) is a line removal marker;
1477                 * do not translate it.
1478                 */
1479                strbuf_addf(&sb,
1480                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
1481                            deletions);
1482        }
1483        strbuf_addch(&sb, '\n');
1484        ret = fputs(sb.buf, fp);
1485        strbuf_release(&sb);
1486        return ret;
1487}
1488
1489static void show_stats(struct diffstat_t *data, struct diff_options *options)
1490{
1491        int i, len, add, del, adds = 0, dels = 0;
1492        uintmax_t max_change = 0, max_len = 0;
1493        int total_files = data->nr, count;
1494        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1495        const char *reset, *add_c, *del_c;
1496        const char *line_prefix = "";
1497        int extra_shown = 0;
1498
1499        if (data->nr == 0)
1500                return;
1501
1502        line_prefix = diff_line_prefix(options);
1503        count = options->stat_count ? options->stat_count : data->nr;
1504
1505        reset = diff_get_color_opt(options, DIFF_RESET);
1506        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1507        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1508
1509        /*
1510         * Find the longest filename and max number of changes
1511         */
1512        for (i = 0; (i < count) && (i < data->nr); i++) {
1513                struct diffstat_file *file = data->files[i];
1514                uintmax_t change = file->added + file->deleted;
1515
1516                if (!file->is_interesting && (change == 0)) {
1517                        count++; /* not shown == room for one more */
1518                        continue;
1519                }
1520                fill_print_name(file);
1521                len = strlen(file->print_name);
1522                if (max_len < len)
1523                        max_len = len;
1524
1525                if (file->is_unmerged) {
1526                        /* "Unmerged" is 8 characters */
1527                        bin_width = bin_width < 8 ? 8 : bin_width;
1528                        continue;
1529                }
1530                if (file->is_binary) {
1531                        /* "Bin XXX -> YYY bytes" */
1532                        int w = 14 + decimal_width(file->added)
1533                                + decimal_width(file->deleted);
1534                        bin_width = bin_width < w ? w : bin_width;
1535                        /* Display change counts aligned with "Bin" */
1536                        number_width = 3;
1537                        continue;
1538                }
1539
1540                if (max_change < change)
1541                        max_change = change;
1542        }
1543        count = i; /* where we can stop scanning in data->files[] */
1544
1545        /*
1546         * We have width = stat_width or term_columns() columns total.
1547         * We want a maximum of min(max_len, stat_name_width) for the name part.
1548         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1549         * We also need 1 for " " and 4 + decimal_width(max_change)
1550         * for " | NNNN " and one the empty column at the end, altogether
1551         * 6 + decimal_width(max_change).
1552         *
1553         * If there's not enough space, we will use the smaller of
1554         * stat_name_width (if set) and 5/8*width for the filename,
1555         * and the rest for constant elements + graph part, but no more
1556         * than stat_graph_width for the graph part.
1557         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1558         * for the standard terminal size).
1559         *
1560         * In other words: stat_width limits the maximum width, and
1561         * stat_name_width fixes the maximum width of the filename,
1562         * and is also used to divide available columns if there
1563         * aren't enough.
1564         *
1565         * Binary files are displayed with "Bin XXX -> YYY bytes"
1566         * instead of the change count and graph. This part is treated
1567         * similarly to the graph part, except that it is not
1568         * "scaled". If total width is too small to accommodate the
1569         * guaranteed minimum width of the filename part and the
1570         * separators and this message, this message will "overflow"
1571         * making the line longer than the maximum width.
1572         */
1573
1574        if (options->stat_width == -1)
1575                width = term_columns() - options->output_prefix_length;
1576        else
1577                width = options->stat_width ? options->stat_width : 80;
1578        number_width = decimal_width(max_change) > number_width ?
1579                decimal_width(max_change) : number_width;
1580
1581        if (options->stat_graph_width == -1)
1582                options->stat_graph_width = diff_stat_graph_width;
1583
1584        /*
1585         * Guarantee 3/8*16==6 for the graph part
1586         * and 5/8*16==10 for the filename part
1587         */
1588        if (width < 16 + 6 + number_width)
1589                width = 16 + 6 + number_width;
1590
1591        /*
1592         * First assign sizes that are wanted, ignoring available width.
1593         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1594         * starting from "XXX" should fit in graph_width.
1595         */
1596        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1597        if (options->stat_graph_width &&
1598            options->stat_graph_width < graph_width)
1599                graph_width = options->stat_graph_width;
1600
1601        name_width = (options->stat_name_width > 0 &&
1602                      options->stat_name_width < max_len) ?
1603                options->stat_name_width : max_len;
1604
1605        /*
1606         * Adjust adjustable widths not to exceed maximum width
1607         */
1608        if (name_width + number_width + 6 + graph_width > width) {
1609                if (graph_width > width * 3/8 - number_width - 6) {
1610                        graph_width = width * 3/8 - number_width - 6;
1611                        if (graph_width < 6)
1612                                graph_width = 6;
1613                }
1614
1615                if (options->stat_graph_width &&
1616                    graph_width > options->stat_graph_width)
1617                        graph_width = options->stat_graph_width;
1618                if (name_width > width - number_width - 6 - graph_width)
1619                        name_width = width - number_width - 6 - graph_width;
1620                else
1621                        graph_width = width - number_width - 6 - name_width;
1622        }
1623
1624        /*
1625         * From here name_width is the width of the name area,
1626         * and graph_width is the width of the graph area.
1627         * max_change is used to scale graph properly.
1628         */
1629        for (i = 0; i < count; i++) {
1630                const char *prefix = "";
1631                struct diffstat_file *file = data->files[i];
1632                char *name = file->print_name;
1633                uintmax_t added = file->added;
1634                uintmax_t deleted = file->deleted;
1635                int name_len;
1636
1637                if (!file->is_interesting && (added + deleted == 0))
1638                        continue;
1639
1640                /*
1641                 * "scale" the filename
1642                 */
1643                len = name_width;
1644                name_len = strlen(name);
1645                if (name_width < name_len) {
1646                        char *slash;
1647                        prefix = "...";
1648                        len -= 3;
1649                        name += name_len - len;
1650                        slash = strchr(name, '/');
1651                        if (slash)
1652                                name = slash;
1653                }
1654
1655                if (file->is_binary) {
1656                        fprintf(options->file, "%s", line_prefix);
1657                        show_name(options->file, prefix, name, len);
1658                        fprintf(options->file, " %*s", number_width, "Bin");
1659                        if (!added && !deleted) {
1660                                putc('\n', options->file);
1661                                continue;
1662                        }
1663                        fprintf(options->file, " %s%"PRIuMAX"%s",
1664                                del_c, deleted, reset);
1665                        fprintf(options->file, " -> ");
1666                        fprintf(options->file, "%s%"PRIuMAX"%s",
1667                                add_c, added, reset);
1668                        fprintf(options->file, " bytes");
1669                        fprintf(options->file, "\n");
1670                        continue;
1671                }
1672                else if (file->is_unmerged) {
1673                        fprintf(options->file, "%s", line_prefix);
1674                        show_name(options->file, prefix, name, len);
1675                        fprintf(options->file, " Unmerged\n");
1676                        continue;
1677                }
1678
1679                /*
1680                 * scale the add/delete
1681                 */
1682                add = added;
1683                del = deleted;
1684
1685                if (graph_width <= max_change) {
1686                        int total = scale_linear(add + del, graph_width, max_change);
1687                        if (total < 2 && add && del)
1688                                /* width >= 2 due to the sanity check */
1689                                total = 2;
1690                        if (add < del) {
1691                                add = scale_linear(add, graph_width, max_change);
1692                                del = total - add;
1693                        } else {
1694                                del = scale_linear(del, graph_width, max_change);
1695                                add = total - del;
1696                        }
1697                }
1698                fprintf(options->file, "%s", line_prefix);
1699                show_name(options->file, prefix, name, len);
1700                fprintf(options->file, " %*"PRIuMAX"%s",
1701                        number_width, added + deleted,
1702                        added + deleted ? " " : "");
1703                show_graph(options->file, '+', add, add_c, reset);
1704                show_graph(options->file, '-', del, del_c, reset);
1705                fprintf(options->file, "\n");
1706        }
1707
1708        for (i = 0; i < data->nr; i++) {
1709                struct diffstat_file *file = data->files[i];
1710                uintmax_t added = file->added;
1711                uintmax_t deleted = file->deleted;
1712
1713                if (file->is_unmerged ||
1714                    (!file->is_interesting && (added + deleted == 0))) {
1715                        total_files--;
1716                        continue;
1717                }
1718
1719                if (!file->is_binary) {
1720                        adds += added;
1721                        dels += deleted;
1722                }
1723                if (i < count)
1724                        continue;
1725                if (!extra_shown)
1726                        fprintf(options->file, "%s ...\n", line_prefix);
1727                extra_shown = 1;
1728        }
1729        fprintf(options->file, "%s", line_prefix);
1730        print_stat_summary(options->file, total_files, adds, dels);
1731}
1732
1733static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1734{
1735        int i, adds = 0, dels = 0, total_files = data->nr;
1736
1737        if (data->nr == 0)
1738                return;
1739
1740        for (i = 0; i < data->nr; i++) {
1741                int added = data->files[i]->added;
1742                int deleted= data->files[i]->deleted;
1743
1744                if (data->files[i]->is_unmerged ||
1745                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
1746                        total_files--;
1747                } else if (!data->files[i]->is_binary) { /* don't count bytes */
1748                        adds += added;
1749                        dels += deleted;
1750                }
1751        }
1752        fprintf(options->file, "%s", diff_line_prefix(options));
1753        print_stat_summary(options->file, total_files, adds, dels);
1754}
1755
1756static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1757{
1758        int i;
1759
1760        if (data->nr == 0)
1761                return;
1762
1763        for (i = 0; i < data->nr; i++) {
1764                struct diffstat_file *file = data->files[i];
1765
1766                fprintf(options->file, "%s", diff_line_prefix(options));
1767
1768                if (file->is_binary)
1769                        fprintf(options->file, "-\t-\t");
1770                else
1771                        fprintf(options->file,
1772                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1773                                file->added, file->deleted);
1774                if (options->line_termination) {
1775                        fill_print_name(file);
1776                        if (!file->is_renamed)
1777                                write_name_quoted(file->name, options->file,
1778                                                  options->line_termination);
1779                        else {
1780                                fputs(file->print_name, options->file);
1781                                putc(options->line_termination, options->file);
1782                        }
1783                } else {
1784                        if (file->is_renamed) {
1785                                putc('\0', options->file);
1786                                write_name_quoted(file->from_name, options->file, '\0');
1787                        }
1788                        write_name_quoted(file->name, options->file, '\0');
1789                }
1790        }
1791}
1792
1793struct dirstat_file {
1794        const char *name;
1795        unsigned long changed;
1796};
1797
1798struct dirstat_dir {
1799        struct dirstat_file *files;
1800        int alloc, nr, permille, cumulative;
1801};
1802
1803static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1804                unsigned long changed, const char *base, int baselen)
1805{
1806        unsigned long this_dir = 0;
1807        unsigned int sources = 0;
1808        const char *line_prefix = diff_line_prefix(opt);
1809
1810        while (dir->nr) {
1811                struct dirstat_file *f = dir->files;
1812                int namelen = strlen(f->name);
1813                unsigned long this;
1814                char *slash;
1815
1816                if (namelen < baselen)
1817                        break;
1818                if (memcmp(f->name, base, baselen))
1819                        break;
1820                slash = strchr(f->name + baselen, '/');
1821                if (slash) {
1822                        int newbaselen = slash + 1 - f->name;
1823                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1824                        sources++;
1825                } else {
1826                        this = f->changed;
1827                        dir->files++;
1828                        dir->nr--;
1829                        sources += 2;
1830                }
1831                this_dir += this;
1832        }
1833
1834        /*
1835         * We don't report dirstat's for
1836         *  - the top level
1837         *  - or cases where everything came from a single directory
1838         *    under this directory (sources == 1).
1839         */
1840        if (baselen && sources != 1) {
1841                if (this_dir) {
1842                        int permille = this_dir * 1000 / changed;
1843                        if (permille >= dir->permille) {
1844                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1845                                        permille / 10, permille % 10, baselen, base);
1846                                if (!dir->cumulative)
1847                                        return 0;
1848                        }
1849                }
1850        }
1851        return this_dir;
1852}
1853
1854static int dirstat_compare(const void *_a, const void *_b)
1855{
1856        const struct dirstat_file *a = _a;
1857        const struct dirstat_file *b = _b;
1858        return strcmp(a->name, b->name);
1859}
1860
1861static void show_dirstat(struct diff_options *options)
1862{
1863        int i;
1864        unsigned long changed;
1865        struct dirstat_dir dir;
1866        struct diff_queue_struct *q = &diff_queued_diff;
1867
1868        dir.files = NULL;
1869        dir.alloc = 0;
1870        dir.nr = 0;
1871        dir.permille = options->dirstat_permille;
1872        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1873
1874        changed = 0;
1875        for (i = 0; i < q->nr; i++) {
1876                struct diff_filepair *p = q->queue[i];
1877                const char *name;
1878                unsigned long copied, added, damage;
1879                int content_changed;
1880
1881                name = p->two->path ? p->two->path : p->one->path;
1882
1883                if (p->one->sha1_valid && p->two->sha1_valid)
1884                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1885                else
1886                        content_changed = 1;
1887
1888                if (!content_changed) {
1889                        /*
1890                         * The SHA1 has not changed, so pre-/post-content is
1891                         * identical. We can therefore skip looking at the
1892                         * file contents altogether.
1893                         */
1894                        damage = 0;
1895                        goto found_damage;
1896                }
1897
1898                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1899                        /*
1900                         * In --dirstat-by-file mode, we don't really need to
1901                         * look at the actual file contents at all.
1902                         * The fact that the SHA1 changed is enough for us to
1903                         * add this file to the list of results
1904                         * (with each file contributing equal damage).
1905                         */
1906                        damage = 1;
1907                        goto found_damage;
1908                }
1909
1910                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1911                        diff_populate_filespec(p->one, 0);
1912                        diff_populate_filespec(p->two, 0);
1913                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1914                                               &copied, &added);
1915                        diff_free_filespec_data(p->one);
1916                        diff_free_filespec_data(p->two);
1917                } else if (DIFF_FILE_VALID(p->one)) {
1918                        diff_populate_filespec(p->one, 1);
1919                        copied = added = 0;
1920                        diff_free_filespec_data(p->one);
1921                } else if (DIFF_FILE_VALID(p->two)) {
1922                        diff_populate_filespec(p->two, 1);
1923                        copied = 0;
1924                        added = p->two->size;
1925                        diff_free_filespec_data(p->two);
1926                } else
1927                        continue;
1928
1929                /*
1930                 * Original minus copied is the removed material,
1931                 * added is the new material.  They are both damages
1932                 * made to the preimage.
1933                 * If the resulting damage is zero, we know that
1934                 * diffcore_count_changes() considers the two entries to
1935                 * be identical, but since content_changed is true, we
1936                 * know that there must have been _some_ kind of change,
1937                 * so we force all entries to have damage > 0.
1938                 */
1939                damage = (p->one->size - copied) + added;
1940                if (!damage)
1941                        damage = 1;
1942
1943found_damage:
1944                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1945                dir.files[dir.nr].name = name;
1946                dir.files[dir.nr].changed = damage;
1947                changed += damage;
1948                dir.nr++;
1949        }
1950
1951        /* This can happen even with many files, if everything was renames */
1952        if (!changed)
1953                return;
1954
1955        /* Show all directories with more than x% of the changes */
1956        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1957        gather_dirstat(options, &dir, changed, "", 0);
1958}
1959
1960static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1961{
1962        int i;
1963        unsigned long changed;
1964        struct dirstat_dir dir;
1965
1966        if (data->nr == 0)
1967                return;
1968
1969        dir.files = NULL;
1970        dir.alloc = 0;
1971        dir.nr = 0;
1972        dir.permille = options->dirstat_permille;
1973        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1974
1975        changed = 0;
1976        for (i = 0; i < data->nr; i++) {
1977                struct diffstat_file *file = data->files[i];
1978                unsigned long damage = file->added + file->deleted;
1979                if (file->is_binary)
1980                        /*
1981                         * binary files counts bytes, not lines. Must find some
1982                         * way to normalize binary bytes vs. textual lines.
1983                         * The following heuristic assumes that there are 64
1984                         * bytes per "line".
1985                         * This is stupid and ugly, but very cheap...
1986                         */
1987                        damage = (damage + 63) / 64;
1988                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1989                dir.files[dir.nr].name = file->name;
1990                dir.files[dir.nr].changed = damage;
1991                changed += damage;
1992                dir.nr++;
1993        }
1994
1995        /* This can happen even with many files, if everything was renames */
1996        if (!changed)
1997                return;
1998
1999        /* Show all directories with more than x% of the changes */
2000        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
2001        gather_dirstat(options, &dir, changed, "", 0);
2002}
2003
2004static void free_diffstat_info(struct diffstat_t *diffstat)
2005{
2006        int i;
2007        for (i = 0; i < diffstat->nr; i++) {
2008                struct diffstat_file *f = diffstat->files[i];
2009                if (f->name != f->print_name)
2010                        free(f->print_name);
2011                free(f->name);
2012                free(f->from_name);
2013                free(f);
2014        }
2015        free(diffstat->files);
2016}
2017
2018struct checkdiff_t {
2019        const char *filename;
2020        int lineno;
2021        int conflict_marker_size;
2022        struct diff_options *o;
2023        unsigned ws_rule;
2024        unsigned status;
2025};
2026
2027static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2028{
2029        char firstchar;
2030        int cnt;
2031
2032        if (len < marker_size + 1)
2033                return 0;
2034        firstchar = line[0];
2035        switch (firstchar) {
2036        case '=': case '>': case '<': case '|':
2037                break;
2038        default:
2039                return 0;
2040        }
2041        for (cnt = 1; cnt < marker_size; cnt++)
2042                if (line[cnt] != firstchar)
2043                        return 0;
2044        /* line[1] thru line[marker_size-1] are same as firstchar */
2045        if (len < marker_size + 1 || !isspace(line[marker_size]))
2046                return 0;
2047        return 1;
2048}
2049
2050static void checkdiff_consume(void *priv, char *line, unsigned long len)
2051{
2052        struct checkdiff_t *data = priv;
2053        int marker_size = data->conflict_marker_size;
2054        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2055        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2056        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2057        char *err;
2058        const char *line_prefix;
2059
2060        assert(data->o);
2061        line_prefix = diff_line_prefix(data->o);
2062
2063        if (line[0] == '+') {
2064                unsigned bad;
2065                data->lineno++;
2066                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2067                        data->status |= 1;
2068                        fprintf(data->o->file,
2069                                "%s%s:%d: leftover conflict marker\n",
2070                                line_prefix, data->filename, data->lineno);
2071                }
2072                bad = ws_check(line + 1, len - 1, data->ws_rule);
2073                if (!bad)
2074                        return;
2075                data->status |= bad;
2076                err = whitespace_error_string(bad);
2077                fprintf(data->o->file, "%s%s:%d: %s.\n",
2078                        line_prefix, data->filename, data->lineno, err);
2079                free(err);
2080                emit_line(data->o, set, reset, line, 1);
2081                ws_check_emit(line + 1, len - 1, data->ws_rule,
2082                              data->o->file, set, reset, ws);
2083        } else if (line[0] == ' ') {
2084                data->lineno++;
2085        } else if (line[0] == '@') {
2086                char *plus = strchr(line, '+');
2087                if (plus)
2088                        data->lineno = strtol(plus, NULL, 10) - 1;
2089                else
2090                        die("invalid diff");
2091        }
2092}
2093
2094static unsigned char *deflate_it(char *data,
2095                                 unsigned long size,
2096                                 unsigned long *result_size)
2097{
2098        int bound;
2099        unsigned char *deflated;
2100        git_zstream stream;
2101
2102        memset(&stream, 0, sizeof(stream));
2103        git_deflate_init(&stream, zlib_compression_level);
2104        bound = git_deflate_bound(&stream, size);
2105        deflated = xmalloc(bound);
2106        stream.next_out = deflated;
2107        stream.avail_out = bound;
2108
2109        stream.next_in = (unsigned char *)data;
2110        stream.avail_in = size;
2111        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2112                ; /* nothing */
2113        git_deflate_end(&stream);
2114        *result_size = stream.total_out;
2115        return deflated;
2116}
2117
2118static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two,
2119                                  const char *prefix)
2120{
2121        void *cp;
2122        void *delta;
2123        void *deflated;
2124        void *data;
2125        unsigned long orig_size;
2126        unsigned long delta_size;
2127        unsigned long deflate_size;
2128        unsigned long data_size;
2129
2130        /* We could do deflated delta, or we could do just deflated two,
2131         * whichever is smaller.
2132         */
2133        delta = NULL;
2134        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2135        if (one->size && two->size) {
2136                delta = diff_delta(one->ptr, one->size,
2137                                   two->ptr, two->size,
2138                                   &delta_size, deflate_size);
2139                if (delta) {
2140                        void *to_free = delta;
2141                        orig_size = delta_size;
2142                        delta = deflate_it(delta, delta_size, &delta_size);
2143                        free(to_free);
2144                }
2145        }
2146
2147        if (delta && delta_size < deflate_size) {
2148                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2149                free(deflated);
2150                data = delta;
2151                data_size = delta_size;
2152        }
2153        else {
2154                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2155                free(delta);
2156                data = deflated;
2157                data_size = deflate_size;
2158        }
2159
2160        /* emit data encoded in base85 */
2161        cp = data;
2162        while (data_size) {
2163                int bytes = (52 < data_size) ? 52 : data_size;
2164                char line[70];
2165                data_size -= bytes;
2166                if (bytes <= 26)
2167                        line[0] = bytes + 'A' - 1;
2168                else
2169                        line[0] = bytes - 26 + 'a' - 1;
2170                encode_85(line + 1, cp, bytes);
2171                cp = (char *) cp + bytes;
2172                fprintf(file, "%s", prefix);
2173                fputs(line, file);
2174                fputc('\n', file);
2175        }
2176        fprintf(file, "%s\n", prefix);
2177        free(data);
2178}
2179
2180static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two,
2181                             const char *prefix)
2182{
2183        fprintf(file, "%sGIT binary patch\n", prefix);
2184        emit_binary_diff_body(file, one, two, prefix);
2185        emit_binary_diff_body(file, two, one, prefix);
2186}
2187
2188int diff_filespec_is_binary(struct diff_filespec *one)
2189{
2190        if (one->is_binary == -1) {
2191                diff_filespec_load_driver(one);
2192                if (one->driver->binary != -1)
2193                        one->is_binary = one->driver->binary;
2194                else {
2195                        if (!one->data && DIFF_FILE_VALID(one))
2196                                diff_populate_filespec(one, 0);
2197                        if (one->data)
2198                                one->is_binary = buffer_is_binary(one->data,
2199                                                one->size);
2200                        if (one->is_binary == -1)
2201                                one->is_binary = 0;
2202                }
2203        }
2204        return one->is_binary;
2205}
2206
2207static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2208{
2209        diff_filespec_load_driver(one);
2210        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2211}
2212
2213void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2214{
2215        if (!options->a_prefix)
2216                options->a_prefix = a;
2217        if (!options->b_prefix)
2218                options->b_prefix = b;
2219}
2220
2221struct userdiff_driver *get_textconv(struct diff_filespec *one)
2222{
2223        if (!DIFF_FILE_VALID(one))
2224                return NULL;
2225
2226        diff_filespec_load_driver(one);
2227        return userdiff_get_textconv(one->driver);
2228}
2229
2230static void builtin_diff(const char *name_a,
2231                         const char *name_b,
2232                         struct diff_filespec *one,
2233                         struct diff_filespec *two,
2234                         const char *xfrm_msg,
2235                         int must_show_header,
2236                         struct diff_options *o,
2237                         int complete_rewrite)
2238{
2239        mmfile_t mf1, mf2;
2240        const char *lbl[2];
2241        char *a_one, *b_two;
2242        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
2243        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2244        const char *a_prefix, *b_prefix;
2245        struct userdiff_driver *textconv_one = NULL;
2246        struct userdiff_driver *textconv_two = NULL;
2247        struct strbuf header = STRBUF_INIT;
2248        const char *line_prefix = diff_line_prefix(o);
2249
2250        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2251                        (!one->mode || S_ISGITLINK(one->mode)) &&
2252                        (!two->mode || S_ISGITLINK(two->mode))) {
2253                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2254                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2255                show_submodule_summary(o->file, one->path ? one->path : two->path,
2256                                line_prefix,
2257                                one->sha1, two->sha1, two->dirty_submodule,
2258                                meta, del, add, reset);
2259                return;
2260        }
2261
2262        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2263                textconv_one = get_textconv(one);
2264                textconv_two = get_textconv(two);
2265        }
2266
2267        diff_set_mnemonic_prefix(o, "a/", "b/");
2268        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2269                a_prefix = o->b_prefix;
2270                b_prefix = o->a_prefix;
2271        } else {
2272                a_prefix = o->a_prefix;
2273                b_prefix = o->b_prefix;
2274        }
2275
2276        /* Never use a non-valid filename anywhere if at all possible */
2277        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2278        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2279
2280        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2281        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2282        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2283        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2284        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
2285        if (lbl[0][0] == '/') {
2286                /* /dev/null */
2287                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
2288                if (xfrm_msg)
2289                        strbuf_addstr(&header, xfrm_msg);
2290                must_show_header = 1;
2291        }
2292        else if (lbl[1][0] == '/') {
2293                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
2294                if (xfrm_msg)
2295                        strbuf_addstr(&header, xfrm_msg);
2296                must_show_header = 1;
2297        }
2298        else {
2299                if (one->mode != two->mode) {
2300                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
2301                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
2302                        must_show_header = 1;
2303                }
2304                if (xfrm_msg)
2305                        strbuf_addstr(&header, xfrm_msg);
2306
2307                /*
2308                 * we do not run diff between different kind
2309                 * of objects.
2310                 */
2311                if ((one->mode ^ two->mode) & S_IFMT)
2312                        goto free_ab_and_return;
2313                if (complete_rewrite &&
2314                    (textconv_one || !diff_filespec_is_binary(one)) &&
2315                    (textconv_two || !diff_filespec_is_binary(two))) {
2316                        fprintf(o->file, "%s", header.buf);
2317                        strbuf_reset(&header);
2318                        emit_rewrite_diff(name_a, name_b, one, two,
2319                                                textconv_one, textconv_two, o);
2320                        o->found_changes = 1;
2321                        goto free_ab_and_return;
2322                }
2323        }
2324
2325        if (o->irreversible_delete && lbl[1][0] == '/') {
2326                fprintf(o->file, "%s", header.buf);
2327                strbuf_reset(&header);
2328                goto free_ab_and_return;
2329        } else if (!DIFF_OPT_TST(o, TEXT) &&
2330            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2331              (!textconv_two && diff_filespec_is_binary(two)) )) {
2332                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2333                        die("unable to read files to diff");
2334                /* Quite common confusing case */
2335                if (mf1.size == mf2.size &&
2336                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2337                        if (must_show_header)
2338                                fprintf(o->file, "%s", header.buf);
2339                        goto free_ab_and_return;
2340                }
2341                fprintf(o->file, "%s", header.buf);
2342                strbuf_reset(&header);
2343                if (DIFF_OPT_TST(o, BINARY))
2344                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2345                else
2346                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2347                                line_prefix, lbl[0], lbl[1]);
2348                o->found_changes = 1;
2349        } else {
2350                /* Crazy xdl interfaces.. */
2351                const char *diffopts = getenv("GIT_DIFF_OPTS");
2352                xpparam_t xpp;
2353                xdemitconf_t xecfg;
2354                struct emit_callback ecbdata;
2355                const struct userdiff_funcname *pe;
2356
2357                if (must_show_header) {
2358                        fprintf(o->file, "%s", header.buf);
2359                        strbuf_reset(&header);
2360                }
2361
2362                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2363                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2364
2365                pe = diff_funcname_pattern(one);
2366                if (!pe)
2367                        pe = diff_funcname_pattern(two);
2368
2369                memset(&xpp, 0, sizeof(xpp));
2370                memset(&xecfg, 0, sizeof(xecfg));
2371                memset(&ecbdata, 0, sizeof(ecbdata));
2372                ecbdata.label_path = lbl;
2373                ecbdata.color_diff = want_color(o->use_color);
2374                ecbdata.found_changesp = &o->found_changes;
2375                ecbdata.ws_rule = whitespace_rule(name_b);
2376                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2377                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2378                ecbdata.opt = o;
2379                ecbdata.header = header.len ? &header : NULL;
2380                xpp.flags = o->xdl_opts;
2381                xecfg.ctxlen = o->context;
2382                xecfg.interhunkctxlen = o->interhunkcontext;
2383                xecfg.flags = XDL_EMIT_FUNCNAMES;
2384                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2385                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2386                if (pe)
2387                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2388                if (!diffopts)
2389                        ;
2390                else if (!prefixcmp(diffopts, "--unified="))
2391                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2392                else if (!prefixcmp(diffopts, "-u"))
2393                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2394                if (o->word_diff)
2395                        init_diff_words_data(&ecbdata, o, one, two);
2396                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2397                              &xpp, &xecfg);
2398                if (o->word_diff)
2399                        free_diff_words_data(&ecbdata);
2400                if (textconv_one)
2401                        free(mf1.ptr);
2402                if (textconv_two)
2403                        free(mf2.ptr);
2404                xdiff_clear_find_func(&xecfg);
2405        }
2406
2407 free_ab_and_return:
2408        strbuf_release(&header);
2409        diff_free_filespec_data(one);
2410        diff_free_filespec_data(two);
2411        free(a_one);
2412        free(b_two);
2413        return;
2414}
2415
2416static void builtin_diffstat(const char *name_a, const char *name_b,
2417                             struct diff_filespec *one,
2418                             struct diff_filespec *two,
2419                             struct diffstat_t *diffstat,
2420                             struct diff_options *o,
2421                             struct diff_filepair *p)
2422{
2423        mmfile_t mf1, mf2;
2424        struct diffstat_file *data;
2425        int same_contents;
2426        int complete_rewrite = 0;
2427
2428        if (!DIFF_PAIR_UNMERGED(p)) {
2429                if (p->status == DIFF_STATUS_MODIFIED && p->score)
2430                        complete_rewrite = 1;
2431        }
2432
2433        data = diffstat_add(diffstat, name_a, name_b);
2434        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
2435
2436        if (!one || !two) {
2437                data->is_unmerged = 1;
2438                return;
2439        }
2440
2441        same_contents = !hashcmp(one->sha1, two->sha1);
2442
2443        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2444                data->is_binary = 1;
2445                if (same_contents) {
2446                        data->added = 0;
2447                        data->deleted = 0;
2448                } else {
2449                        data->added = diff_filespec_size(two);
2450                        data->deleted = diff_filespec_size(one);
2451                }
2452        }
2453
2454        else if (complete_rewrite) {
2455                diff_populate_filespec(one, 0);
2456                diff_populate_filespec(two, 0);
2457                data->deleted = count_lines(one->data, one->size);
2458                data->added = count_lines(two->data, two->size);
2459        }
2460
2461        else if (!same_contents) {
2462                /* Crazy xdl interfaces.. */
2463                xpparam_t xpp;
2464                xdemitconf_t xecfg;
2465
2466                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2467                        die("unable to read files to diff");
2468
2469                memset(&xpp, 0, sizeof(xpp));
2470                memset(&xecfg, 0, sizeof(xecfg));
2471                xpp.flags = o->xdl_opts;
2472                xecfg.ctxlen = o->context;
2473                xecfg.interhunkctxlen = o->interhunkcontext;
2474                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2475                              &xpp, &xecfg);
2476        }
2477
2478        diff_free_filespec_data(one);
2479        diff_free_filespec_data(two);
2480}
2481
2482static void builtin_checkdiff(const char *name_a, const char *name_b,
2483                              const char *attr_path,
2484                              struct diff_filespec *one,
2485                              struct diff_filespec *two,
2486                              struct diff_options *o)
2487{
2488        mmfile_t mf1, mf2;
2489        struct checkdiff_t data;
2490
2491        if (!two)
2492                return;
2493
2494        memset(&data, 0, sizeof(data));
2495        data.filename = name_b ? name_b : name_a;
2496        data.lineno = 0;
2497        data.o = o;
2498        data.ws_rule = whitespace_rule(attr_path);
2499        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2500
2501        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2502                die("unable to read files to diff");
2503
2504        /*
2505         * All the other codepaths check both sides, but not checking
2506         * the "old" side here is deliberate.  We are checking the newly
2507         * introduced changes, and as long as the "new" side is text, we
2508         * can and should check what it introduces.
2509         */
2510        if (diff_filespec_is_binary(two))
2511                goto free_and_return;
2512        else {
2513                /* Crazy xdl interfaces.. */
2514                xpparam_t xpp;
2515                xdemitconf_t xecfg;
2516
2517                memset(&xpp, 0, sizeof(xpp));
2518                memset(&xecfg, 0, sizeof(xecfg));
2519                xecfg.ctxlen = 1; /* at least one context line */
2520                xpp.flags = 0;
2521                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2522                              &xpp, &xecfg);
2523
2524                if (data.ws_rule & WS_BLANK_AT_EOF) {
2525                        struct emit_callback ecbdata;
2526                        int blank_at_eof;
2527
2528                        ecbdata.ws_rule = data.ws_rule;
2529                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2530                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2531
2532                        if (blank_at_eof) {
2533                                static char *err;
2534                                if (!err)
2535                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2536                                fprintf(o->file, "%s:%d: %s.\n",
2537                                        data.filename, blank_at_eof, err);
2538                                data.status = 1; /* report errors */
2539                        }
2540                }
2541        }
2542 free_and_return:
2543        diff_free_filespec_data(one);
2544        diff_free_filespec_data(two);
2545        if (data.status)
2546                DIFF_OPT_SET(o, CHECK_FAILED);
2547}
2548
2549struct diff_filespec *alloc_filespec(const char *path)
2550{
2551        int namelen = strlen(path);
2552        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2553
2554        memset(spec, 0, sizeof(*spec));
2555        spec->path = (char *)(spec + 1);
2556        memcpy(spec->path, path, namelen+1);
2557        spec->count = 1;
2558        spec->is_binary = -1;
2559        return spec;
2560}
2561
2562void free_filespec(struct diff_filespec *spec)
2563{
2564        if (!--spec->count) {
2565                diff_free_filespec_data(spec);
2566                free(spec);
2567        }
2568}
2569
2570void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2571                   int sha1_valid, unsigned short mode)
2572{
2573        if (mode) {
2574                spec->mode = canon_mode(mode);
2575                hashcpy(spec->sha1, sha1);
2576                spec->sha1_valid = sha1_valid;
2577        }
2578}
2579
2580/*
2581 * Given a name and sha1 pair, if the index tells us the file in
2582 * the work tree has that object contents, return true, so that
2583 * prepare_temp_file() does not have to inflate and extract.
2584 */
2585static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2586{
2587        const struct cache_entry *ce;
2588        struct stat st;
2589        int pos, len;
2590
2591        /*
2592         * We do not read the cache ourselves here, because the
2593         * benchmark with my previous version that always reads cache
2594         * shows that it makes things worse for diff-tree comparing
2595         * two linux-2.6 kernel trees in an already checked out work
2596         * tree.  This is because most diff-tree comparisons deal with
2597         * only a small number of files, while reading the cache is
2598         * expensive for a large project, and its cost outweighs the
2599         * savings we get by not inflating the object to a temporary
2600         * file.  Practically, this code only helps when we are used
2601         * by diff-cache --cached, which does read the cache before
2602         * calling us.
2603         */
2604        if (!active_cache)
2605                return 0;
2606
2607        /* We want to avoid the working directory if our caller
2608         * doesn't need the data in a normal file, this system
2609         * is rather slow with its stat/open/mmap/close syscalls,
2610         * and the object is contained in a pack file.  The pack
2611         * is probably already open and will be faster to obtain
2612         * the data through than the working directory.  Loose
2613         * objects however would tend to be slower as they need
2614         * to be individually opened and inflated.
2615         */
2616        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2617                return 0;
2618
2619        len = strlen(name);
2620        pos = cache_name_pos(name, len);
2621        if (pos < 0)
2622                return 0;
2623        ce = active_cache[pos];
2624
2625        /*
2626         * This is not the sha1 we are looking for, or
2627         * unreusable because it is not a regular file.
2628         */
2629        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2630                return 0;
2631
2632        /*
2633         * If ce is marked as "assume unchanged", there is no
2634         * guarantee that work tree matches what we are looking for.
2635         */
2636        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2637                return 0;
2638
2639        /*
2640         * If ce matches the file in the work tree, we can reuse it.
2641         */
2642        if (ce_uptodate(ce) ||
2643            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2644                return 1;
2645
2646        return 0;
2647}
2648
2649static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2650{
2651        int len;
2652        char *data = xmalloc(100), *dirty = "";
2653
2654        /* Are we looking at the work tree? */
2655        if (s->dirty_submodule)
2656                dirty = "-dirty";
2657
2658        len = snprintf(data, 100,
2659                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2660        s->data = data;
2661        s->size = len;
2662        s->should_free = 1;
2663        if (size_only) {
2664                s->data = NULL;
2665                free(data);
2666        }
2667        return 0;
2668}
2669
2670/*
2671 * While doing rename detection and pickaxe operation, we may need to
2672 * grab the data for the blob (or file) for our own in-core comparison.
2673 * diff_filespec has data and size fields for this purpose.
2674 */
2675int diff_populate_filespec(struct diff_filespec *s, int size_only)
2676{
2677        int err = 0;
2678        /*
2679         * demote FAIL to WARN to allow inspecting the situation
2680         * instead of refusing.
2681         */
2682        enum safe_crlf crlf_warn = (safe_crlf == SAFE_CRLF_FAIL
2683                                    ? SAFE_CRLF_WARN
2684                                    : safe_crlf);
2685
2686        if (!DIFF_FILE_VALID(s))
2687                die("internal error: asking to populate invalid file.");
2688        if (S_ISDIR(s->mode))
2689                return -1;
2690
2691        if (s->data)
2692                return 0;
2693
2694        if (size_only && 0 < s->size)
2695                return 0;
2696
2697        if (S_ISGITLINK(s->mode))
2698                return diff_populate_gitlink(s, size_only);
2699
2700        if (!s->sha1_valid ||
2701            reuse_worktree_file(s->path, s->sha1, 0)) {
2702                struct strbuf buf = STRBUF_INIT;
2703                struct stat st;
2704                int fd;
2705
2706                if (lstat(s->path, &st) < 0) {
2707                        if (errno == ENOENT) {
2708                        err_empty:
2709                                err = -1;
2710                        empty:
2711                                s->data = (char *)"";
2712                                s->size = 0;
2713                                return err;
2714                        }
2715                }
2716                s->size = xsize_t(st.st_size);
2717                if (!s->size)
2718                        goto empty;
2719                if (S_ISLNK(st.st_mode)) {
2720                        struct strbuf sb = STRBUF_INIT;
2721
2722                        if (strbuf_readlink(&sb, s->path, s->size))
2723                                goto err_empty;
2724                        s->size = sb.len;
2725                        s->data = strbuf_detach(&sb, NULL);
2726                        s->should_free = 1;
2727                        return 0;
2728                }
2729                if (size_only)
2730                        return 0;
2731                fd = open(s->path, O_RDONLY);
2732                if (fd < 0)
2733                        goto err_empty;
2734                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2735                close(fd);
2736                s->should_munmap = 1;
2737
2738                /*
2739                 * Convert from working tree format to canonical git format
2740                 */
2741                if (convert_to_git(s->path, s->data, s->size, &buf, crlf_warn)) {
2742                        size_t size = 0;
2743                        munmap(s->data, s->size);
2744                        s->should_munmap = 0;
2745                        s->data = strbuf_detach(&buf, &size);
2746                        s->size = size;
2747                        s->should_free = 1;
2748                }
2749        }
2750        else {
2751                enum object_type type;
2752                if (size_only) {
2753                        type = sha1_object_info(s->sha1, &s->size);
2754                        if (type < 0)
2755                                die("unable to read %s", sha1_to_hex(s->sha1));
2756                } else {
2757                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2758                        if (!s->data)
2759                                die("unable to read %s", sha1_to_hex(s->sha1));
2760                        s->should_free = 1;
2761                }
2762        }
2763        return 0;
2764}
2765
2766void diff_free_filespec_blob(struct diff_filespec *s)
2767{
2768        if (s->should_free)
2769                free(s->data);
2770        else if (s->should_munmap)
2771                munmap(s->data, s->size);
2772
2773        if (s->should_free || s->should_munmap) {
2774                s->should_free = s->should_munmap = 0;
2775                s->data = NULL;
2776        }
2777}
2778
2779void diff_free_filespec_data(struct diff_filespec *s)
2780{
2781        diff_free_filespec_blob(s);
2782        free(s->cnt_data);
2783        s->cnt_data = NULL;
2784}
2785
2786static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2787                           void *blob,
2788                           unsigned long size,
2789                           const unsigned char *sha1,
2790                           int mode)
2791{
2792        int fd;
2793        struct strbuf buf = STRBUF_INIT;
2794        struct strbuf template = STRBUF_INIT;
2795        char *path_dup = xstrdup(path);
2796        const char *base = basename(path_dup);
2797
2798        /* Generate "XXXXXX_basename.ext" */
2799        strbuf_addstr(&template, "XXXXXX_");
2800        strbuf_addstr(&template, base);
2801
2802        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2803                        strlen(base) + 1);
2804        if (fd < 0)
2805                die_errno("unable to create temp-file");
2806        if (convert_to_working_tree(path,
2807                        (const char *)blob, (size_t)size, &buf)) {
2808                blob = buf.buf;
2809                size = buf.len;
2810        }
2811        if (write_in_full(fd, blob, size) != size)
2812                die_errno("unable to write temp-file");
2813        close(fd);
2814        temp->name = temp->tmp_path;
2815        strcpy(temp->hex, sha1_to_hex(sha1));
2816        temp->hex[40] = 0;
2817        sprintf(temp->mode, "%06o", mode);
2818        strbuf_release(&buf);
2819        strbuf_release(&template);
2820        free(path_dup);
2821}
2822
2823static struct diff_tempfile *prepare_temp_file(const char *name,
2824                struct diff_filespec *one)
2825{
2826        struct diff_tempfile *temp = claim_diff_tempfile();
2827
2828        if (!DIFF_FILE_VALID(one)) {
2829        not_a_valid_file:
2830                /* A '-' entry produces this for file-2, and
2831                 * a '+' entry produces this for file-1.
2832                 */
2833                temp->name = "/dev/null";
2834                strcpy(temp->hex, ".");
2835                strcpy(temp->mode, ".");
2836                return temp;
2837        }
2838
2839        if (!remove_tempfile_installed) {
2840                atexit(remove_tempfile);
2841                sigchain_push_common(remove_tempfile_on_signal);
2842                remove_tempfile_installed = 1;
2843        }
2844
2845        if (!one->sha1_valid ||
2846            reuse_worktree_file(name, one->sha1, 1)) {
2847                struct stat st;
2848                if (lstat(name, &st) < 0) {
2849                        if (errno == ENOENT)
2850                                goto not_a_valid_file;
2851                        die_errno("stat(%s)", name);
2852                }
2853                if (S_ISLNK(st.st_mode)) {
2854                        struct strbuf sb = STRBUF_INIT;
2855                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2856                                die_errno("readlink(%s)", name);
2857                        prep_temp_blob(name, temp, sb.buf, sb.len,
2858                                       (one->sha1_valid ?
2859                                        one->sha1 : null_sha1),
2860                                       (one->sha1_valid ?
2861                                        one->mode : S_IFLNK));
2862                        strbuf_release(&sb);
2863                }
2864                else {
2865                        /* we can borrow from the file in the work tree */
2866                        temp->name = name;
2867                        if (!one->sha1_valid)
2868                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2869                        else
2870                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2871                        /* Even though we may sometimes borrow the
2872                         * contents from the work tree, we always want
2873                         * one->mode.  mode is trustworthy even when
2874                         * !(one->sha1_valid), as long as
2875                         * DIFF_FILE_VALID(one).
2876                         */
2877                        sprintf(temp->mode, "%06o", one->mode);
2878                }
2879                return temp;
2880        }
2881        else {
2882                if (diff_populate_filespec(one, 0))
2883                        die("cannot read data blob for %s", one->path);
2884                prep_temp_blob(name, temp, one->data, one->size,
2885                               one->sha1, one->mode);
2886        }
2887        return temp;
2888}
2889
2890/* An external diff command takes:
2891 *
2892 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2893 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2894 *
2895 */
2896static void run_external_diff(const char *pgm,
2897                              const char *name,
2898                              const char *other,
2899                              struct diff_filespec *one,
2900                              struct diff_filespec *two,
2901                              const char *xfrm_msg,
2902                              int complete_rewrite)
2903{
2904        const char *spawn_arg[10];
2905        int retval;
2906        const char **arg = &spawn_arg[0];
2907
2908        if (one && two) {
2909                struct diff_tempfile *temp_one, *temp_two;
2910                const char *othername = (other ? other : name);
2911                temp_one = prepare_temp_file(name, one);
2912                temp_two = prepare_temp_file(othername, two);
2913                *arg++ = pgm;
2914                *arg++ = name;
2915                *arg++ = temp_one->name;
2916                *arg++ = temp_one->hex;
2917                *arg++ = temp_one->mode;
2918                *arg++ = temp_two->name;
2919                *arg++ = temp_two->hex;
2920                *arg++ = temp_two->mode;
2921                if (other) {
2922                        *arg++ = other;
2923                        *arg++ = xfrm_msg;
2924                }
2925        } else {
2926                *arg++ = pgm;
2927                *arg++ = name;
2928        }
2929        *arg = NULL;
2930        fflush(NULL);
2931        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2932        remove_tempfile();
2933        if (retval) {
2934                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2935                exit(1);
2936        }
2937}
2938
2939static int similarity_index(struct diff_filepair *p)
2940{
2941        return p->score * 100 / MAX_SCORE;
2942}
2943
2944static void fill_metainfo(struct strbuf *msg,
2945                          const char *name,
2946                          const char *other,
2947                          struct diff_filespec *one,
2948                          struct diff_filespec *two,
2949                          struct diff_options *o,
2950                          struct diff_filepair *p,
2951                          int *must_show_header,
2952                          int use_color)
2953{
2954        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2955        const char *reset = diff_get_color(use_color, DIFF_RESET);
2956        const char *line_prefix = diff_line_prefix(o);
2957
2958        *must_show_header = 1;
2959        strbuf_init(msg, PATH_MAX * 2 + 300);
2960        switch (p->status) {
2961        case DIFF_STATUS_COPIED:
2962                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2963                            line_prefix, set, similarity_index(p));
2964                strbuf_addf(msg, "%s\n%s%scopy from ",
2965                            reset,  line_prefix, set);
2966                quote_c_style(name, msg, NULL, 0);
2967                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2968                quote_c_style(other, msg, NULL, 0);
2969                strbuf_addf(msg, "%s\n", reset);
2970                break;
2971        case DIFF_STATUS_RENAMED:
2972                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2973                            line_prefix, set, similarity_index(p));
2974                strbuf_addf(msg, "%s\n%s%srename from ",
2975                            reset, line_prefix, set);
2976                quote_c_style(name, msg, NULL, 0);
2977                strbuf_addf(msg, "%s\n%s%srename to ",
2978                            reset, line_prefix, set);
2979                quote_c_style(other, msg, NULL, 0);
2980                strbuf_addf(msg, "%s\n", reset);
2981                break;
2982        case DIFF_STATUS_MODIFIED:
2983                if (p->score) {
2984                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2985                                    line_prefix,
2986                                    set, similarity_index(p), reset);
2987                        break;
2988                }
2989                /* fallthru */
2990        default:
2991                *must_show_header = 0;
2992        }
2993        if (one && two && hashcmp(one->sha1, two->sha1)) {
2994                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2995
2996                if (DIFF_OPT_TST(o, BINARY)) {
2997                        mmfile_t mf;
2998                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2999                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3000                                abbrev = 40;
3001                }
3002                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
3003                            find_unique_abbrev(one->sha1, abbrev));
3004                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
3005                if (one->mode == two->mode)
3006                        strbuf_addf(msg, " %06o", one->mode);
3007                strbuf_addf(msg, "%s\n", reset);
3008        }
3009}
3010
3011static void run_diff_cmd(const char *pgm,
3012                         const char *name,
3013                         const char *other,
3014                         const char *attr_path,
3015                         struct diff_filespec *one,
3016                         struct diff_filespec *two,
3017                         struct strbuf *msg,
3018                         struct diff_options *o,
3019                         struct diff_filepair *p)
3020{
3021        const char *xfrm_msg = NULL;
3022        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3023        int must_show_header = 0;
3024
3025
3026        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3027                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3028                if (drv && drv->external)
3029                        pgm = drv->external;
3030        }
3031
3032        if (msg) {
3033                /*
3034                 * don't use colors when the header is intended for an
3035                 * external diff driver
3036                 */
3037                fill_metainfo(msg, name, other, one, two, o, p,
3038                              &must_show_header,
3039                              want_color(o->use_color) && !pgm);
3040                xfrm_msg = msg->len ? msg->buf : NULL;
3041        }
3042
3043        if (pgm) {
3044                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3045                                  complete_rewrite);
3046                return;
3047        }
3048        if (one && two)
3049                builtin_diff(name, other ? other : name,
3050                             one, two, xfrm_msg, must_show_header,
3051                             o, complete_rewrite);
3052        else
3053                fprintf(o->file, "* Unmerged path %s\n", name);
3054}
3055
3056static void diff_fill_sha1_info(struct diff_filespec *one)
3057{
3058        if (DIFF_FILE_VALID(one)) {
3059                if (!one->sha1_valid) {
3060                        struct stat st;
3061                        if (one->is_stdin) {
3062                                hashcpy(one->sha1, null_sha1);
3063                                return;
3064                        }
3065                        if (lstat(one->path, &st) < 0)
3066                                die_errno("stat '%s'", one->path);
3067                        if (index_path(one->sha1, one->path, &st, 0))
3068                                die("cannot hash %s", one->path);
3069                }
3070        }
3071        else
3072                hashclr(one->sha1);
3073}
3074
3075static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3076{
3077        /* Strip the prefix but do not molest /dev/null and absolute paths */
3078        if (*namep && **namep != '/') {
3079                *namep += prefix_length;
3080                if (**namep == '/')
3081                        ++*namep;
3082        }
3083        if (*otherp && **otherp != '/') {
3084                *otherp += prefix_length;
3085                if (**otherp == '/')
3086                        ++*otherp;
3087        }
3088}
3089
3090static void run_diff(struct diff_filepair *p, struct diff_options *o)
3091{
3092        const char *pgm = external_diff();
3093        struct strbuf msg;
3094        struct diff_filespec *one = p->one;
3095        struct diff_filespec *two = p->two;
3096        const char *name;
3097        const char *other;
3098        const char *attr_path;
3099
3100        name  = p->one->path;
3101        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3102        attr_path = name;
3103        if (o->prefix_length)
3104                strip_prefix(o->prefix_length, &name, &other);
3105
3106        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3107                pgm = NULL;
3108
3109        if (DIFF_PAIR_UNMERGED(p)) {
3110                run_diff_cmd(pgm, name, NULL, attr_path,
3111                             NULL, NULL, NULL, o, p);
3112                return;
3113        }
3114
3115        diff_fill_sha1_info(one);
3116        diff_fill_sha1_info(two);
3117
3118        if (!pgm &&
3119            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3120            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3121                /*
3122                 * a filepair that changes between file and symlink
3123                 * needs to be split into deletion and creation.
3124                 */
3125                struct diff_filespec *null = alloc_filespec(two->path);
3126                run_diff_cmd(NULL, name, other, attr_path,
3127                             one, null, &msg, o, p);
3128                free(null);
3129                strbuf_release(&msg);
3130
3131                null = alloc_filespec(one->path);
3132                run_diff_cmd(NULL, name, other, attr_path,
3133                             null, two, &msg, o, p);
3134                free(null);
3135        }
3136        else
3137                run_diff_cmd(pgm, name, other, attr_path,
3138                             one, two, &msg, o, p);
3139
3140        strbuf_release(&msg);
3141}
3142
3143static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3144                         struct diffstat_t *diffstat)
3145{
3146        const char *name;
3147        const char *other;
3148
3149        if (DIFF_PAIR_UNMERGED(p)) {
3150                /* unmerged */
3151                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
3152                return;
3153        }
3154
3155        name = p->one->path;
3156        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3157
3158        if (o->prefix_length)
3159                strip_prefix(o->prefix_length, &name, &other);
3160
3161        diff_fill_sha1_info(p->one);
3162        diff_fill_sha1_info(p->two);
3163
3164        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
3165}
3166
3167static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3168{
3169        const char *name;
3170        const char *other;
3171        const char *attr_path;
3172
3173        if (DIFF_PAIR_UNMERGED(p)) {
3174                /* unmerged */
3175                return;
3176        }
3177
3178        name = p->one->path;
3179        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3180        attr_path = other ? other : name;
3181
3182        if (o->prefix_length)
3183                strip_prefix(o->prefix_length, &name, &other);
3184
3185        diff_fill_sha1_info(p->one);
3186        diff_fill_sha1_info(p->two);
3187
3188        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3189}
3190
3191void diff_setup(struct diff_options *options)
3192{
3193        memcpy(options, &default_diff_options, sizeof(*options));
3194
3195        options->file = stdout;
3196
3197        options->line_termination = '\n';
3198        options->break_opt = -1;
3199        options->rename_limit = -1;
3200        options->dirstat_permille = diff_dirstat_permille_default;
3201        options->context = diff_context_default;
3202        DIFF_OPT_SET(options, RENAME_EMPTY);
3203
3204        options->change = diff_change;
3205        options->add_remove = diff_addremove;
3206        options->use_color = diff_use_color_default;
3207        options->detect_rename = diff_detect_rename_default;
3208        options->xdl_opts |= diff_algorithm;
3209
3210        if (diff_no_prefix) {
3211                options->a_prefix = options->b_prefix = "";
3212        } else if (!diff_mnemonic_prefix) {
3213                options->a_prefix = "a/";
3214                options->b_prefix = "b/";
3215        }
3216}
3217
3218void diff_setup_done(struct diff_options *options)
3219{
3220        int count = 0;
3221
3222        if (options->output_format & DIFF_FORMAT_NAME)
3223                count++;
3224        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3225                count++;
3226        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3227                count++;
3228        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3229                count++;
3230        if (count > 1)
3231                die("--name-only, --name-status, --check and -s are mutually exclusive");
3232
3233        /*
3234         * Most of the time we can say "there are changes"
3235         * only by checking if there are changed paths, but
3236         * --ignore-whitespace* options force us to look
3237         * inside contents.
3238         */
3239
3240        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3241            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3242            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3243                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3244        else
3245                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3246
3247        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3248                options->detect_rename = DIFF_DETECT_COPY;
3249
3250        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3251                options->prefix = NULL;
3252        if (options->prefix)
3253                options->prefix_length = strlen(options->prefix);
3254        else
3255                options->prefix_length = 0;
3256
3257        if (options->output_format & (DIFF_FORMAT_NAME |
3258                                      DIFF_FORMAT_NAME_STATUS |
3259                                      DIFF_FORMAT_CHECKDIFF |
3260                                      DIFF_FORMAT_NO_OUTPUT))
3261                options->output_format &= ~(DIFF_FORMAT_RAW |
3262                                            DIFF_FORMAT_NUMSTAT |
3263                                            DIFF_FORMAT_DIFFSTAT |
3264                                            DIFF_FORMAT_SHORTSTAT |
3265                                            DIFF_FORMAT_DIRSTAT |
3266                                            DIFF_FORMAT_SUMMARY |
3267                                            DIFF_FORMAT_PATCH);
3268
3269        /*
3270         * These cases always need recursive; we do not drop caller-supplied
3271         * recursive bits for other formats here.
3272         */
3273        if (options->output_format & (DIFF_FORMAT_PATCH |
3274                                      DIFF_FORMAT_NUMSTAT |
3275                                      DIFF_FORMAT_DIFFSTAT |
3276                                      DIFF_FORMAT_SHORTSTAT |
3277                                      DIFF_FORMAT_DIRSTAT |
3278                                      DIFF_FORMAT_SUMMARY |
3279                                      DIFF_FORMAT_CHECKDIFF))
3280                DIFF_OPT_SET(options, RECURSIVE);
3281        /*
3282         * Also pickaxe would not work very well if you do not say recursive
3283         */
3284        if (options->pickaxe)
3285                DIFF_OPT_SET(options, RECURSIVE);
3286        /*
3287         * When patches are generated, submodules diffed against the work tree
3288         * must be checked for dirtiness too so it can be shown in the output
3289         */
3290        if (options->output_format & DIFF_FORMAT_PATCH)
3291                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3292
3293        if (options->detect_rename && options->rename_limit < 0)
3294                options->rename_limit = diff_rename_limit_default;
3295        if (options->setup & DIFF_SETUP_USE_CACHE) {
3296                if (!active_cache)
3297                        /* read-cache does not die even when it fails
3298                         * so it is safe for us to do this here.  Also
3299                         * it does not smudge active_cache or active_nr
3300                         * when it fails, so we do not have to worry about
3301                         * cleaning it up ourselves either.
3302                         */
3303                        read_cache();
3304        }
3305        if (options->abbrev <= 0 || 40 < options->abbrev)
3306                options->abbrev = 40; /* full */
3307
3308        /*
3309         * It does not make sense to show the first hit we happened
3310         * to have found.  It does not make sense not to return with
3311         * exit code in such a case either.
3312         */
3313        if (DIFF_OPT_TST(options, QUICK)) {
3314                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3315                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3316        }
3317}
3318
3319static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3320{
3321        char c, *eq;
3322        int len;
3323
3324        if (*arg != '-')
3325                return 0;
3326        c = *++arg;
3327        if (!c)
3328                return 0;
3329        if (c == arg_short) {
3330                c = *++arg;
3331                if (!c)
3332                        return 1;
3333                if (val && isdigit(c)) {
3334                        char *end;
3335                        int n = strtoul(arg, &end, 10);
3336                        if (*end)
3337                                return 0;
3338                        *val = n;
3339                        return 1;
3340                }
3341                return 0;
3342        }
3343        if (c != '-')
3344                return 0;
3345        arg++;
3346        eq = strchr(arg, '=');
3347        if (eq)
3348                len = eq - arg;
3349        else
3350                len = strlen(arg);
3351        if (!len || strncmp(arg, arg_long, len))
3352                return 0;
3353        if (eq) {
3354                int n;
3355                char *end;
3356                if (!isdigit(*++eq))
3357                        return 0;
3358                n = strtoul(eq, &end, 10);
3359                if (*end)
3360                        return 0;
3361                *val = n;
3362        }
3363        return 1;
3364}
3365
3366static int diff_scoreopt_parse(const char *opt);
3367
3368static inline int short_opt(char opt, const char **argv,
3369                            const char **optarg)
3370{
3371        const char *arg = argv[0];
3372        if (arg[0] != '-' || arg[1] != opt)
3373                return 0;
3374        if (arg[2] != '\0') {
3375                *optarg = arg + 2;
3376                return 1;
3377        }
3378        if (!argv[1])
3379                die("Option '%c' requires a value", opt);
3380        *optarg = argv[1];
3381        return 2;
3382}
3383
3384int parse_long_opt(const char *opt, const char **argv,
3385                   const char **optarg)
3386{
3387        const char *arg = argv[0];
3388        if (arg[0] != '-' || arg[1] != '-')
3389                return 0;
3390        arg += strlen("--");
3391        if (prefixcmp(arg, opt))
3392                return 0;
3393        arg += strlen(opt);
3394        if (*arg == '=') { /* sticked form: --option=value */
3395                *optarg = arg + 1;
3396                return 1;
3397        }
3398        if (*arg != '\0')
3399                return 0;
3400        /* separate form: --option value */
3401        if (!argv[1])
3402                die("Option '--%s' requires a value", opt);
3403        *optarg = argv[1];
3404        return 2;
3405}
3406
3407static int stat_opt(struct diff_options *options, const char **av)
3408{
3409        const char *arg = av[0];
3410        char *end;
3411        int width = options->stat_width;
3412        int name_width = options->stat_name_width;
3413        int graph_width = options->stat_graph_width;
3414        int count = options->stat_count;
3415        int argcount = 1;
3416
3417        arg += strlen("--stat");
3418        end = (char *)arg;
3419
3420        switch (*arg) {
3421        case '-':
3422                if (!prefixcmp(arg, "-width")) {
3423                        arg += strlen("-width");
3424                        if (*arg == '=')
3425                                width = strtoul(arg + 1, &end, 10);
3426                        else if (!*arg && !av[1])
3427                                die("Option '--stat-width' requires a value");
3428                        else if (!*arg) {
3429                                width = strtoul(av[1], &end, 10);
3430                                argcount = 2;
3431                        }
3432                } else if (!prefixcmp(arg, "-name-width")) {
3433                        arg += strlen("-name-width");
3434                        if (*arg == '=')
3435                                name_width = strtoul(arg + 1, &end, 10);
3436                        else if (!*arg && !av[1])
3437                                die("Option '--stat-name-width' requires a value");
3438                        else if (!*arg) {
3439                                name_width = strtoul(av[1], &end, 10);
3440                                argcount = 2;
3441                        }
3442                } else if (!prefixcmp(arg, "-graph-width")) {
3443                        arg += strlen("-graph-width");
3444                        if (*arg == '=')
3445                                graph_width = strtoul(arg + 1, &end, 10);
3446                        else if (!*arg && !av[1])
3447                                die("Option '--stat-graph-width' requires a value");
3448                        else if (!*arg) {
3449                                graph_width = strtoul(av[1], &end, 10);
3450                                argcount = 2;
3451                        }
3452                } else if (!prefixcmp(arg, "-count")) {
3453                        arg += strlen("-count");
3454                        if (*arg == '=')
3455                                count = strtoul(arg + 1, &end, 10);
3456                        else if (!*arg && !av[1])
3457                                die("Option '--stat-count' requires a value");
3458                        else if (!*arg) {
3459                                count = strtoul(av[1], &end, 10);
3460                                argcount = 2;
3461                        }
3462                }
3463                break;
3464        case '=':
3465                width = strtoul(arg+1, &end, 10);
3466                if (*end == ',')
3467                        name_width = strtoul(end+1, &end, 10);
3468                if (*end == ',')
3469                        count = strtoul(end+1, &end, 10);
3470        }
3471
3472        /* Important! This checks all the error cases! */
3473        if (*end)
3474                return 0;
3475        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3476        options->stat_name_width = name_width;
3477        options->stat_graph_width = graph_width;
3478        options->stat_width = width;
3479        options->stat_count = count;
3480        return argcount;
3481}
3482
3483static int parse_dirstat_opt(struct diff_options *options, const char *params)
3484{
3485        struct strbuf errmsg = STRBUF_INIT;
3486        if (parse_dirstat_params(options, params, &errmsg))
3487                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3488                    errmsg.buf);
3489        strbuf_release(&errmsg);
3490        /*
3491         * The caller knows a dirstat-related option is given from the command
3492         * line; allow it to say "return this_function();"
3493         */
3494        options->output_format |= DIFF_FORMAT_DIRSTAT;
3495        return 1;
3496}
3497
3498static int parse_submodule_opt(struct diff_options *options, const char *value)
3499{
3500        if (parse_submodule_params(options, value))
3501                die(_("Failed to parse --submodule option parameter: '%s'"),
3502                        value);
3503        return 1;
3504}
3505
3506static const char diff_status_letters[] = {
3507        DIFF_STATUS_ADDED,
3508        DIFF_STATUS_COPIED,
3509        DIFF_STATUS_DELETED,
3510        DIFF_STATUS_MODIFIED,
3511        DIFF_STATUS_RENAMED,
3512        DIFF_STATUS_TYPE_CHANGED,
3513        DIFF_STATUS_UNKNOWN,
3514        DIFF_STATUS_UNMERGED,
3515        DIFF_STATUS_FILTER_AON,
3516        DIFF_STATUS_FILTER_BROKEN,
3517        '\0',
3518};
3519
3520static unsigned int filter_bit['Z' + 1];
3521
3522static void prepare_filter_bits(void)
3523{
3524        int i;
3525
3526        if (!filter_bit[DIFF_STATUS_ADDED]) {
3527                for (i = 0; diff_status_letters[i]; i++)
3528                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
3529        }
3530}
3531
3532static unsigned filter_bit_tst(char status, const struct diff_options *opt)
3533{
3534        return opt->filter & filter_bit[(int) status];
3535}
3536
3537static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
3538{
3539        int i, optch;
3540
3541        prepare_filter_bits();
3542
3543        /*
3544         * If there is a negation e.g. 'd' in the input, and we haven't
3545         * initialized the filter field with another --diff-filter, start
3546         * from full set of bits, except for AON.
3547         */
3548        if (!opt->filter) {
3549                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3550                        if (optch < 'a' || 'z' < optch)
3551                                continue;
3552                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
3553                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
3554                        break;
3555                }
3556        }
3557
3558        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3559                unsigned int bit;
3560                int negate;
3561
3562                if ('a' <= optch && optch <= 'z') {
3563                        negate = 1;
3564                        optch = toupper(optch);
3565                } else {
3566                        negate = 0;
3567                }
3568
3569                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
3570                if (!bit)
3571                        return optarg[i];
3572                if (negate)
3573                        opt->filter &= ~bit;
3574                else
3575                        opt->filter |= bit;
3576        }
3577        return 0;
3578}
3579
3580/* Used only by "diff-files" and "diff --no-index" */
3581void handle_deprecated_show_diff_q(struct diff_options *opt)
3582{
3583        warning("'diff -q' and 'diff-files -q' are deprecated.");
3584        warning("Use 'diff --diff-filter=d' instead to ignore deleted filepairs.");
3585        parse_diff_filter_opt("d", opt);
3586}
3587
3588static void enable_patch_output(int *fmt) {
3589        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
3590        *fmt |= DIFF_FORMAT_PATCH;
3591}
3592
3593int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3594{
3595        const char *arg = av[0];
3596        const char *optarg;
3597        int argcount;
3598
3599        /* Output format options */
3600        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
3601            || opt_arg(arg, 'U', "unified", &options->context))
3602                enable_patch_output(&options->output_format);
3603        else if (!strcmp(arg, "--raw"))
3604                options->output_format |= DIFF_FORMAT_RAW;
3605        else if (!strcmp(arg, "--patch-with-raw")) {
3606                enable_patch_output(&options->output_format);
3607                options->output_format |= DIFF_FORMAT_RAW;
3608        } else if (!strcmp(arg, "--numstat"))
3609                options->output_format |= DIFF_FORMAT_NUMSTAT;
3610        else if (!strcmp(arg, "--shortstat"))
3611                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3612        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3613                return parse_dirstat_opt(options, "");
3614        else if (!prefixcmp(arg, "-X"))
3615                return parse_dirstat_opt(options, arg + 2);
3616        else if (!prefixcmp(arg, "--dirstat="))
3617                return parse_dirstat_opt(options, arg + 10);
3618        else if (!strcmp(arg, "--cumulative"))
3619                return parse_dirstat_opt(options, "cumulative");
3620        else if (!strcmp(arg, "--dirstat-by-file"))
3621                return parse_dirstat_opt(options, "files");
3622        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3623                parse_dirstat_opt(options, "files");
3624                return parse_dirstat_opt(options, arg + 18);
3625        }
3626        else if (!strcmp(arg, "--check"))
3627                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3628        else if (!strcmp(arg, "--summary"))
3629                options->output_format |= DIFF_FORMAT_SUMMARY;
3630        else if (!strcmp(arg, "--patch-with-stat")) {
3631                enable_patch_output(&options->output_format);
3632                options->output_format |= DIFF_FORMAT_DIFFSTAT;
3633        } else if (!strcmp(arg, "--name-only"))
3634                options->output_format |= DIFF_FORMAT_NAME;
3635        else if (!strcmp(arg, "--name-status"))
3636                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3637        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
3638                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3639        else if (!prefixcmp(arg, "--stat"))
3640                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3641                return stat_opt(options, av);
3642
3643        /* renames options */
3644        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3645                 !strcmp(arg, "--break-rewrites")) {
3646                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3647                        return error("invalid argument to -B: %s", arg+2);
3648        }
3649        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3650                 !strcmp(arg, "--find-renames")) {
3651                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3652                        return error("invalid argument to -M: %s", arg+2);
3653                options->detect_rename = DIFF_DETECT_RENAME;
3654        }
3655        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3656                options->irreversible_delete = 1;
3657        }
3658        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3659                 !strcmp(arg, "--find-copies")) {
3660                if (options->detect_rename == DIFF_DETECT_COPY)
3661                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3662                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3663                        return error("invalid argument to -C: %s", arg+2);
3664                options->detect_rename = DIFF_DETECT_COPY;
3665        }
3666        else if (!strcmp(arg, "--no-renames"))
3667                options->detect_rename = 0;
3668        else if (!strcmp(arg, "--rename-empty"))
3669                DIFF_OPT_SET(options, RENAME_EMPTY);
3670        else if (!strcmp(arg, "--no-rename-empty"))
3671                DIFF_OPT_CLR(options, RENAME_EMPTY);
3672        else if (!strcmp(arg, "--relative"))
3673                DIFF_OPT_SET(options, RELATIVE_NAME);
3674        else if (!prefixcmp(arg, "--relative=")) {
3675                DIFF_OPT_SET(options, RELATIVE_NAME);
3676                options->prefix = arg + 11;
3677        }
3678
3679        /* xdiff options */
3680        else if (!strcmp(arg, "--minimal"))
3681                DIFF_XDL_SET(options, NEED_MINIMAL);
3682        else if (!strcmp(arg, "--no-minimal"))
3683                DIFF_XDL_CLR(options, NEED_MINIMAL);
3684        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3685                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3686        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3687                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3688        else if (!strcmp(arg, "--ignore-space-at-eol"))
3689                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3690        else if (!strcmp(arg, "--ignore-blank-lines"))
3691                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
3692        else if (!strcmp(arg, "--patience"))
3693                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3694        else if (!strcmp(arg, "--histogram"))
3695                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3696        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
3697                long value = parse_algorithm_value(optarg);
3698                if (value < 0)
3699                        return error("option diff-algorithm accepts \"myers\", "
3700                                     "\"minimal\", \"patience\" and \"histogram\"");
3701                /* clear out previous settings */
3702                DIFF_XDL_CLR(options, NEED_MINIMAL);
3703                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
3704                options->xdl_opts |= value;
3705                return argcount;
3706        }
3707
3708        /* flags options */
3709        else if (!strcmp(arg, "--binary")) {
3710                enable_patch_output(&options->output_format);
3711                DIFF_OPT_SET(options, BINARY);
3712        }
3713        else if (!strcmp(arg, "--full-index"))
3714                DIFF_OPT_SET(options, FULL_INDEX);
3715        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3716                DIFF_OPT_SET(options, TEXT);
3717        else if (!strcmp(arg, "-R"))
3718                DIFF_OPT_SET(options, REVERSE_DIFF);
3719        else if (!strcmp(arg, "--find-copies-harder"))
3720                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3721        else if (!strcmp(arg, "--follow"))
3722                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3723        else if (!strcmp(arg, "--no-follow"))
3724                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
3725        else if (!strcmp(arg, "--color"))
3726                options->use_color = 1;
3727        else if (!prefixcmp(arg, "--color=")) {
3728                int value = git_config_colorbool(NULL, arg+8);
3729                if (value < 0)
3730                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3731                options->use_color = value;
3732        }
3733        else if (!strcmp(arg, "--no-color"))
3734                options->use_color = 0;
3735        else if (!strcmp(arg, "--color-words")) {
3736                options->use_color = 1;
3737                options->word_diff = DIFF_WORDS_COLOR;
3738        }
3739        else if (!prefixcmp(arg, "--color-words=")) {
3740                options->use_color = 1;
3741                options->word_diff = DIFF_WORDS_COLOR;
3742                options->word_regex = arg + 14;
3743        }
3744        else if (!strcmp(arg, "--word-diff")) {
3745                if (options->word_diff == DIFF_WORDS_NONE)
3746                        options->word_diff = DIFF_WORDS_PLAIN;
3747        }
3748        else if (!prefixcmp(arg, "--word-diff=")) {
3749                const char *type = arg + 12;
3750                if (!strcmp(type, "plain"))
3751                        options->word_diff = DIFF_WORDS_PLAIN;
3752                else if (!strcmp(type, "color")) {
3753                        options->use_color = 1;
3754                        options->word_diff = DIFF_WORDS_COLOR;
3755                }
3756                else if (!strcmp(type, "porcelain"))
3757                        options->word_diff = DIFF_WORDS_PORCELAIN;
3758                else if (!strcmp(type, "none"))
3759                        options->word_diff = DIFF_WORDS_NONE;
3760                else
3761                        die("bad --word-diff argument: %s", type);
3762        }
3763        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3764                if (options->word_diff == DIFF_WORDS_NONE)
3765                        options->word_diff = DIFF_WORDS_PLAIN;
3766                options->word_regex = optarg;
3767                return argcount;
3768        }
3769        else if (!strcmp(arg, "--exit-code"))
3770                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3771        else if (!strcmp(arg, "--quiet"))
3772                DIFF_OPT_SET(options, QUICK);
3773        else if (!strcmp(arg, "--ext-diff"))
3774                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3775        else if (!strcmp(arg, "--no-ext-diff"))
3776                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3777        else if (!strcmp(arg, "--textconv"))
3778                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3779        else if (!strcmp(arg, "--no-textconv"))
3780                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3781        else if (!strcmp(arg, "--ignore-submodules")) {
3782                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3783                handle_ignore_submodules_arg(options, "all");
3784        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3785                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3786                handle_ignore_submodules_arg(options, arg + 20);
3787        } else if (!strcmp(arg, "--submodule"))
3788                DIFF_OPT_SET(options, SUBMODULE_LOG);
3789        else if (!prefixcmp(arg, "--submodule="))
3790                return parse_submodule_opt(options, arg + 12);
3791
3792        /* misc options */
3793        else if (!strcmp(arg, "-z"))
3794                options->line_termination = 0;
3795        else if ((argcount = short_opt('l', av, &optarg))) {
3796                options->rename_limit = strtoul(optarg, NULL, 10);
3797                return argcount;
3798        }
3799        else if ((argcount = short_opt('S', av, &optarg))) {
3800                options->pickaxe = optarg;
3801                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3802                return argcount;
3803        } else if ((argcount = short_opt('G', av, &optarg))) {
3804                options->pickaxe = optarg;
3805                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3806                return argcount;
3807        }
3808        else if (!strcmp(arg, "--pickaxe-all"))
3809                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3810        else if (!strcmp(arg, "--pickaxe-regex"))
3811                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3812        else if ((argcount = short_opt('O', av, &optarg))) {
3813                options->orderfile = optarg;
3814                return argcount;
3815        }
3816        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3817                int offending = parse_diff_filter_opt(optarg, options);
3818                if (offending)
3819                        die("unknown change class '%c' in --diff-filter=%s",
3820                            offending, optarg);
3821                return argcount;
3822        }
3823        else if (!strcmp(arg, "--abbrev"))
3824                options->abbrev = DEFAULT_ABBREV;
3825        else if (!prefixcmp(arg, "--abbrev=")) {
3826                options->abbrev = strtoul(arg + 9, NULL, 10);
3827                if (options->abbrev < MINIMUM_ABBREV)
3828                        options->abbrev = MINIMUM_ABBREV;
3829                else if (40 < options->abbrev)
3830                        options->abbrev = 40;
3831        }
3832        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3833                options->a_prefix = optarg;
3834                return argcount;
3835        }
3836        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3837                options->b_prefix = optarg;
3838                return argcount;
3839        }
3840        else if (!strcmp(arg, "--no-prefix"))
3841                options->a_prefix = options->b_prefix = "";
3842        else if (opt_arg(arg, '\0', "inter-hunk-context",
3843                         &options->interhunkcontext))
3844                ;
3845        else if (!strcmp(arg, "-W"))
3846                DIFF_OPT_SET(options, FUNCCONTEXT);
3847        else if (!strcmp(arg, "--function-context"))
3848                DIFF_OPT_SET(options, FUNCCONTEXT);
3849        else if (!strcmp(arg, "--no-function-context"))
3850                DIFF_OPT_CLR(options, FUNCCONTEXT);
3851        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3852                options->file = fopen(optarg, "w");
3853                if (!options->file)
3854                        die_errno("Could not open '%s'", optarg);
3855                options->close_file = 1;
3856                return argcount;
3857        } else
3858                return 0;
3859        return 1;
3860}
3861
3862int parse_rename_score(const char **cp_p)
3863{
3864        unsigned long num, scale;
3865        int ch, dot;
3866        const char *cp = *cp_p;
3867
3868        num = 0;
3869        scale = 1;
3870        dot = 0;
3871        for (;;) {
3872                ch = *cp;
3873                if ( !dot && ch == '.' ) {
3874                        scale = 1;
3875                        dot = 1;
3876                } else if ( ch == '%' ) {
3877                        scale = dot ? scale*100 : 100;
3878                        cp++;   /* % is always at the end */
3879                        break;
3880                } else if ( ch >= '0' && ch <= '9' ) {
3881                        if ( scale < 100000 ) {
3882                                scale *= 10;
3883                                num = (num*10) + (ch-'0');
3884                        }
3885                } else {
3886                        break;
3887                }
3888                cp++;
3889        }
3890        *cp_p = cp;
3891
3892        /* user says num divided by scale and we say internally that
3893         * is MAX_SCORE * num / scale.
3894         */
3895        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3896}
3897
3898static int diff_scoreopt_parse(const char *opt)
3899{
3900        int opt1, opt2, cmd;
3901
3902        if (*opt++ != '-')
3903                return -1;
3904        cmd = *opt++;
3905        if (cmd == '-') {
3906                /* convert the long-form arguments into short-form versions */
3907                if (!prefixcmp(opt, "break-rewrites")) {
3908                        opt += strlen("break-rewrites");
3909                        if (*opt == 0 || *opt++ == '=')
3910                                cmd = 'B';
3911                } else if (!prefixcmp(opt, "find-copies")) {
3912                        opt += strlen("find-copies");
3913                        if (*opt == 0 || *opt++ == '=')
3914                                cmd = 'C';
3915                } else if (!prefixcmp(opt, "find-renames")) {
3916                        opt += strlen("find-renames");
3917                        if (*opt == 0 || *opt++ == '=')
3918                                cmd = 'M';
3919                }
3920        }
3921        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3922                return -1; /* that is not a -M, -C nor -B option */
3923
3924        opt1 = parse_rename_score(&opt);
3925        if (cmd != 'B')
3926                opt2 = 0;
3927        else {
3928                if (*opt == 0)
3929                        opt2 = 0;
3930                else if (*opt != '/')
3931                        return -1; /* we expect -B80/99 or -B80 */
3932                else {
3933                        opt++;
3934                        opt2 = parse_rename_score(&opt);
3935                }
3936        }
3937        if (*opt != 0)
3938                return -1;
3939        return opt1 | (opt2 << 16);
3940}
3941
3942struct diff_queue_struct diff_queued_diff;
3943
3944void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3945{
3946        if (queue->alloc <= queue->nr) {
3947                queue->alloc = alloc_nr(queue->alloc);
3948                queue->queue = xrealloc(queue->queue,
3949                                        sizeof(dp) * queue->alloc);
3950        }
3951        queue->queue[queue->nr++] = dp;
3952}
3953
3954struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3955                                 struct diff_filespec *one,
3956                                 struct diff_filespec *two)
3957{
3958        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3959        dp->one = one;
3960        dp->two = two;
3961        if (queue)
3962                diff_q(queue, dp);
3963        return dp;
3964}
3965
3966void diff_free_filepair(struct diff_filepair *p)
3967{
3968        free_filespec(p->one);
3969        free_filespec(p->two);
3970        free(p);
3971}
3972
3973/* This is different from find_unique_abbrev() in that
3974 * it stuffs the result with dots for alignment.
3975 */
3976const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3977{
3978        int abblen;
3979        const char *abbrev;
3980        if (len == 40)
3981                return sha1_to_hex(sha1);
3982
3983        abbrev = find_unique_abbrev(sha1, len);
3984        abblen = strlen(abbrev);
3985        if (abblen < 37) {
3986                static char hex[41];
3987                if (len < abblen && abblen <= len + 2)
3988                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3989                else
3990                        sprintf(hex, "%s...", abbrev);
3991                return hex;
3992        }
3993        return sha1_to_hex(sha1);
3994}
3995
3996static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3997{
3998        int line_termination = opt->line_termination;
3999        int inter_name_termination = line_termination ? '\t' : '\0';
4000
4001        fprintf(opt->file, "%s", diff_line_prefix(opt));
4002        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
4003                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
4004                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
4005                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
4006        }
4007        if (p->score) {
4008                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
4009                        inter_name_termination);
4010        } else {
4011                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
4012        }
4013
4014        if (p->status == DIFF_STATUS_COPIED ||
4015            p->status == DIFF_STATUS_RENAMED) {
4016                const char *name_a, *name_b;
4017                name_a = p->one->path;
4018                name_b = p->two->path;
4019                strip_prefix(opt->prefix_length, &name_a, &name_b);
4020                write_name_quoted(name_a, opt->file, inter_name_termination);
4021                write_name_quoted(name_b, opt->file, line_termination);
4022        } else {
4023                const char *name_a, *name_b;
4024                name_a = p->one->mode ? p->one->path : p->two->path;
4025                name_b = NULL;
4026                strip_prefix(opt->prefix_length, &name_a, &name_b);
4027                write_name_quoted(name_a, opt->file, line_termination);
4028        }
4029}
4030
4031int diff_unmodified_pair(struct diff_filepair *p)
4032{
4033        /* This function is written stricter than necessary to support
4034         * the currently implemented transformers, but the idea is to
4035         * let transformers to produce diff_filepairs any way they want,
4036         * and filter and clean them up here before producing the output.
4037         */
4038        struct diff_filespec *one = p->one, *two = p->two;
4039
4040        if (DIFF_PAIR_UNMERGED(p))
4041                return 0; /* unmerged is interesting */
4042
4043        /* deletion, addition, mode or type change
4044         * and rename are all interesting.
4045         */
4046        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
4047            DIFF_PAIR_MODE_CHANGED(p) ||
4048            strcmp(one->path, two->path))
4049                return 0;
4050
4051        /* both are valid and point at the same path.  that is, we are
4052         * dealing with a change.
4053         */
4054        if (one->sha1_valid && two->sha1_valid &&
4055            !hashcmp(one->sha1, two->sha1) &&
4056            !one->dirty_submodule && !two->dirty_submodule)
4057                return 1; /* no change */
4058        if (!one->sha1_valid && !two->sha1_valid)
4059                return 1; /* both look at the same file on the filesystem. */
4060        return 0;
4061}
4062
4063static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
4064{
4065        if (diff_unmodified_pair(p))
4066                return;
4067
4068        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4069            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4070                return; /* no tree diffs in patch format */
4071
4072        run_diff(p, o);
4073}
4074
4075static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
4076                            struct diffstat_t *diffstat)
4077{
4078        if (diff_unmodified_pair(p))
4079                return;
4080
4081        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4082            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4083                return; /* no useful stat for tree diffs */
4084
4085        run_diffstat(p, o, diffstat);
4086}
4087
4088static void diff_flush_checkdiff(struct diff_filepair *p,
4089                struct diff_options *o)
4090{
4091        if (diff_unmodified_pair(p))
4092                return;
4093
4094        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4095            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4096                return; /* nothing to check in tree diffs */
4097
4098        run_checkdiff(p, o);
4099}
4100
4101int diff_queue_is_empty(void)
4102{
4103        struct diff_queue_struct *q = &diff_queued_diff;
4104        int i;
4105        for (i = 0; i < q->nr; i++)
4106                if (!diff_unmodified_pair(q->queue[i]))
4107                        return 0;
4108        return 1;
4109}
4110
4111#if DIFF_DEBUG
4112void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
4113{
4114        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
4115                x, one ? one : "",
4116                s->path,
4117                DIFF_FILE_VALID(s) ? "valid" : "invalid",
4118                s->mode,
4119                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
4120        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
4121                x, one ? one : "",
4122                s->size, s->xfrm_flags);
4123}
4124
4125void diff_debug_filepair(const struct diff_filepair *p, int i)
4126{
4127        diff_debug_filespec(p->one, i, "one");
4128        diff_debug_filespec(p->two, i, "two");
4129        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4130                p->score, p->status ? p->status : '?',
4131                p->one->rename_used, p->broken_pair);
4132}
4133
4134void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4135{
4136        int i;
4137        if (msg)
4138                fprintf(stderr, "%s\n", msg);
4139        fprintf(stderr, "q->nr = %d\n", q->nr);
4140        for (i = 0; i < q->nr; i++) {
4141                struct diff_filepair *p = q->queue[i];
4142                diff_debug_filepair(p, i);
4143        }
4144}
4145#endif
4146
4147static void diff_resolve_rename_copy(void)
4148{
4149        int i;
4150        struct diff_filepair *p;
4151        struct diff_queue_struct *q = &diff_queued_diff;
4152
4153        diff_debug_queue("resolve-rename-copy", q);
4154
4155        for (i = 0; i < q->nr; i++) {
4156                p = q->queue[i];
4157                p->status = 0; /* undecided */
4158                if (DIFF_PAIR_UNMERGED(p))
4159                        p->status = DIFF_STATUS_UNMERGED;
4160                else if (!DIFF_FILE_VALID(p->one))
4161                        p->status = DIFF_STATUS_ADDED;
4162                else if (!DIFF_FILE_VALID(p->two))
4163                        p->status = DIFF_STATUS_DELETED;
4164                else if (DIFF_PAIR_TYPE_CHANGED(p))
4165                        p->status = DIFF_STATUS_TYPE_CHANGED;
4166
4167                /* from this point on, we are dealing with a pair
4168                 * whose both sides are valid and of the same type, i.e.
4169                 * either in-place edit or rename/copy edit.
4170                 */
4171                else if (DIFF_PAIR_RENAME(p)) {
4172                        /*
4173                         * A rename might have re-connected a broken
4174                         * pair up, causing the pathnames to be the
4175                         * same again. If so, that's not a rename at
4176                         * all, just a modification..
4177                         *
4178                         * Otherwise, see if this source was used for
4179                         * multiple renames, in which case we decrement
4180                         * the count, and call it a copy.
4181                         */
4182                        if (!strcmp(p->one->path, p->two->path))
4183                                p->status = DIFF_STATUS_MODIFIED;
4184                        else if (--p->one->rename_used > 0)
4185                                p->status = DIFF_STATUS_COPIED;
4186                        else
4187                                p->status = DIFF_STATUS_RENAMED;
4188                }
4189                else if (hashcmp(p->one->sha1, p->two->sha1) ||
4190                         p->one->mode != p->two->mode ||
4191                         p->one->dirty_submodule ||
4192                         p->two->dirty_submodule ||
4193                         is_null_sha1(p->one->sha1))
4194                        p->status = DIFF_STATUS_MODIFIED;
4195                else {
4196                        /* This is a "no-change" entry and should not
4197                         * happen anymore, but prepare for broken callers.
4198                         */
4199                        error("feeding unmodified %s to diffcore",
4200                              p->one->path);
4201                        p->status = DIFF_STATUS_UNKNOWN;
4202                }
4203        }
4204        diff_debug_queue("resolve-rename-copy done", q);
4205}
4206
4207static int check_pair_status(struct diff_filepair *p)
4208{
4209        switch (p->status) {
4210        case DIFF_STATUS_UNKNOWN:
4211                return 0;
4212        case 0:
4213                die("internal error in diff-resolve-rename-copy");
4214        default:
4215                return 1;
4216        }
4217}
4218
4219static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4220{
4221        int fmt = opt->output_format;
4222
4223        if (fmt & DIFF_FORMAT_CHECKDIFF)
4224                diff_flush_checkdiff(p, opt);
4225        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4226                diff_flush_raw(p, opt);
4227        else if (fmt & DIFF_FORMAT_NAME) {
4228                const char *name_a, *name_b;
4229                name_a = p->two->path;
4230                name_b = NULL;
4231                strip_prefix(opt->prefix_length, &name_a, &name_b);
4232                write_name_quoted(name_a, opt->file, opt->line_termination);
4233        }
4234}
4235
4236static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4237{
4238        if (fs->mode)
4239                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4240        else
4241                fprintf(file, " %s ", newdelete);
4242        write_name_quoted(fs->path, file, '\n');
4243}
4244
4245
4246static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4247                const char *line_prefix)
4248{
4249        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4250                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4251                        p->two->mode, show_name ? ' ' : '\n');
4252                if (show_name) {
4253                        write_name_quoted(p->two->path, file, '\n');
4254                }
4255        }
4256}
4257
4258static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4259                        const char *line_prefix)
4260{
4261        char *names = pprint_rename(p->one->path, p->two->path);
4262
4263        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4264        free(names);
4265        show_mode_change(file, p, 0, line_prefix);
4266}
4267
4268static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4269{
4270        FILE *file = opt->file;
4271        const char *line_prefix = diff_line_prefix(opt);
4272
4273        switch(p->status) {
4274        case DIFF_STATUS_DELETED:
4275                fputs(line_prefix, file);
4276                show_file_mode_name(file, "delete", p->one);
4277                break;
4278        case DIFF_STATUS_ADDED:
4279                fputs(line_prefix, file);
4280                show_file_mode_name(file, "create", p->two);
4281                break;
4282        case DIFF_STATUS_COPIED:
4283                fputs(line_prefix, file);
4284                show_rename_copy(file, "copy", p, line_prefix);
4285                break;
4286        case DIFF_STATUS_RENAMED:
4287                fputs(line_prefix, file);
4288                show_rename_copy(file, "rename", p, line_prefix);
4289                break;
4290        default:
4291                if (p->score) {
4292                        fprintf(file, "%s rewrite ", line_prefix);
4293                        write_name_quoted(p->two->path, file, ' ');
4294                        fprintf(file, "(%d%%)\n", similarity_index(p));
4295                }
4296                show_mode_change(file, p, !p->score, line_prefix);
4297                break;
4298        }
4299}
4300
4301struct patch_id_t {
4302        git_SHA_CTX *ctx;
4303        int patchlen;
4304};
4305
4306static int remove_space(char *line, int len)
4307{
4308        int i;
4309        char *dst = line;
4310        unsigned char c;
4311
4312        for (i = 0; i < len; i++)
4313                if (!isspace((c = line[i])))
4314                        *dst++ = c;
4315
4316        return dst - line;
4317}
4318
4319static void patch_id_consume(void *priv, char *line, unsigned long len)
4320{
4321        struct patch_id_t *data = priv;
4322        int new_len;
4323
4324        /* Ignore line numbers when computing the SHA1 of the patch */
4325        if (!prefixcmp(line, "@@ -"))
4326                return;
4327
4328        new_len = remove_space(line, len);
4329
4330        git_SHA1_Update(data->ctx, line, new_len);
4331        data->patchlen += new_len;
4332}
4333
4334/* returns 0 upon success, and writes result into sha1 */
4335static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4336{
4337        struct diff_queue_struct *q = &diff_queued_diff;
4338        int i;
4339        git_SHA_CTX ctx;
4340        struct patch_id_t data;
4341        char buffer[PATH_MAX * 4 + 20];
4342
4343        git_SHA1_Init(&ctx);
4344        memset(&data, 0, sizeof(struct patch_id_t));
4345        data.ctx = &ctx;
4346
4347        for (i = 0; i < q->nr; i++) {
4348                xpparam_t xpp;
4349                xdemitconf_t xecfg;
4350                mmfile_t mf1, mf2;
4351                struct diff_filepair *p = q->queue[i];
4352                int len1, len2;
4353
4354                memset(&xpp, 0, sizeof(xpp));
4355                memset(&xecfg, 0, sizeof(xecfg));
4356                if (p->status == 0)
4357                        return error("internal diff status error");
4358                if (p->status == DIFF_STATUS_UNKNOWN)
4359                        continue;
4360                if (diff_unmodified_pair(p))
4361                        continue;
4362                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4363                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4364                        continue;
4365                if (DIFF_PAIR_UNMERGED(p))
4366                        continue;
4367
4368                diff_fill_sha1_info(p->one);
4369                diff_fill_sha1_info(p->two);
4370                if (fill_mmfile(&mf1, p->one) < 0 ||
4371                                fill_mmfile(&mf2, p->two) < 0)
4372                        return error("unable to read files to diff");
4373
4374                len1 = remove_space(p->one->path, strlen(p->one->path));
4375                len2 = remove_space(p->two->path, strlen(p->two->path));
4376                if (p->one->mode == 0)
4377                        len1 = snprintf(buffer, sizeof(buffer),
4378                                        "diff--gita/%.*sb/%.*s"
4379                                        "newfilemode%06o"
4380                                        "---/dev/null"
4381                                        "+++b/%.*s",
4382                                        len1, p->one->path,
4383                                        len2, p->two->path,
4384                                        p->two->mode,
4385                                        len2, p->two->path);
4386                else if (p->two->mode == 0)
4387                        len1 = snprintf(buffer, sizeof(buffer),
4388                                        "diff--gita/%.*sb/%.*s"
4389                                        "deletedfilemode%06o"
4390                                        "---a/%.*s"
4391                                        "+++/dev/null",
4392                                        len1, p->one->path,
4393                                        len2, p->two->path,
4394                                        p->one->mode,
4395                                        len1, p->one->path);
4396                else
4397                        len1 = snprintf(buffer, sizeof(buffer),
4398                                        "diff--gita/%.*sb/%.*s"
4399                                        "---a/%.*s"
4400                                        "+++b/%.*s",
4401                                        len1, p->one->path,
4402                                        len2, p->two->path,
4403                                        len1, p->one->path,
4404                                        len2, p->two->path);
4405                git_SHA1_Update(&ctx, buffer, len1);
4406
4407                if (diff_filespec_is_binary(p->one) ||
4408                    diff_filespec_is_binary(p->two)) {
4409                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4410                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4411                        continue;
4412                }
4413
4414                xpp.flags = 0;
4415                xecfg.ctxlen = 3;
4416                xecfg.flags = 0;
4417                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4418                              &xpp, &xecfg);
4419        }
4420
4421        git_SHA1_Final(sha1, &ctx);
4422        return 0;
4423}
4424
4425int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4426{
4427        struct diff_queue_struct *q = &diff_queued_diff;
4428        int i;
4429        int result = diff_get_patch_id(options, sha1);
4430
4431        for (i = 0; i < q->nr; i++)
4432                diff_free_filepair(q->queue[i]);
4433
4434        free(q->queue);
4435        DIFF_QUEUE_CLEAR(q);
4436
4437        return result;
4438}
4439
4440static int is_summary_empty(const struct diff_queue_struct *q)
4441{
4442        int i;
4443
4444        for (i = 0; i < q->nr; i++) {
4445                const struct diff_filepair *p = q->queue[i];
4446
4447                switch (p->status) {
4448                case DIFF_STATUS_DELETED:
4449                case DIFF_STATUS_ADDED:
4450                case DIFF_STATUS_COPIED:
4451                case DIFF_STATUS_RENAMED:
4452                        return 0;
4453                default:
4454                        if (p->score)
4455                                return 0;
4456                        if (p->one->mode && p->two->mode &&
4457                            p->one->mode != p->two->mode)
4458                                return 0;
4459                        break;
4460                }
4461        }
4462        return 1;
4463}
4464
4465static const char rename_limit_warning[] =
4466"inexact rename detection was skipped due to too many files.";
4467
4468static const char degrade_cc_to_c_warning[] =
4469"only found copies from modified paths due to too many files.";
4470
4471static const char rename_limit_advice[] =
4472"you may want to set your %s variable to at least "
4473"%d and retry the command.";
4474
4475void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4476{
4477        if (degraded_cc)
4478                warning(degrade_cc_to_c_warning);
4479        else if (needed)
4480                warning(rename_limit_warning);
4481        else
4482                return;
4483        if (0 < needed && needed < 32767)
4484                warning(rename_limit_advice, varname, needed);
4485}
4486
4487void diff_flush(struct diff_options *options)
4488{
4489        struct diff_queue_struct *q = &diff_queued_diff;
4490        int i, output_format = options->output_format;
4491        int separator = 0;
4492        int dirstat_by_line = 0;
4493
4494        /*
4495         * Order: raw, stat, summary, patch
4496         * or:    name/name-status/checkdiff (other bits clear)
4497         */
4498        if (!q->nr)
4499                goto free_queue;
4500
4501        if (output_format & (DIFF_FORMAT_RAW |
4502                             DIFF_FORMAT_NAME |
4503                             DIFF_FORMAT_NAME_STATUS |
4504                             DIFF_FORMAT_CHECKDIFF)) {
4505                for (i = 0; i < q->nr; i++) {
4506                        struct diff_filepair *p = q->queue[i];
4507                        if (check_pair_status(p))
4508                                flush_one_pair(p, options);
4509                }
4510                separator++;
4511        }
4512
4513        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4514                dirstat_by_line = 1;
4515
4516        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4517            dirstat_by_line) {
4518                struct diffstat_t diffstat;
4519
4520                memset(&diffstat, 0, sizeof(struct diffstat_t));
4521                for (i = 0; i < q->nr; i++) {
4522                        struct diff_filepair *p = q->queue[i];
4523                        if (check_pair_status(p))
4524                                diff_flush_stat(p, options, &diffstat);
4525                }
4526                if (output_format & DIFF_FORMAT_NUMSTAT)
4527                        show_numstat(&diffstat, options);
4528                if (output_format & DIFF_FORMAT_DIFFSTAT)
4529                        show_stats(&diffstat, options);
4530                if (output_format & DIFF_FORMAT_SHORTSTAT)
4531                        show_shortstats(&diffstat, options);
4532                if (output_format & DIFF_FORMAT_DIRSTAT)
4533                        show_dirstat_by_line(&diffstat, options);
4534                free_diffstat_info(&diffstat);
4535                separator++;
4536        }
4537        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4538                show_dirstat(options);
4539
4540        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4541                for (i = 0; i < q->nr; i++) {
4542                        diff_summary(options, q->queue[i]);
4543                }
4544                separator++;
4545        }
4546
4547        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4548            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4549            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4550                /*
4551                 * run diff_flush_patch for the exit status. setting
4552                 * options->file to /dev/null should be safe, because we
4553                 * aren't supposed to produce any output anyway.
4554                 */
4555                if (options->close_file)
4556                        fclose(options->file);
4557                options->file = fopen("/dev/null", "w");
4558                if (!options->file)
4559                        die_errno("Could not open /dev/null");
4560                options->close_file = 1;
4561                for (i = 0; i < q->nr; i++) {
4562                        struct diff_filepair *p = q->queue[i];
4563                        if (check_pair_status(p))
4564                                diff_flush_patch(p, options);
4565                        if (options->found_changes)
4566                                break;
4567                }
4568        }
4569
4570        if (output_format & DIFF_FORMAT_PATCH) {
4571                if (separator) {
4572                        fprintf(options->file, "%s%c",
4573                                diff_line_prefix(options),
4574                                options->line_termination);
4575                        if (options->stat_sep) {
4576                                /* attach patch instead of inline */
4577                                fputs(options->stat_sep, options->file);
4578                        }
4579                }
4580
4581                for (i = 0; i < q->nr; i++) {
4582                        struct diff_filepair *p = q->queue[i];
4583                        if (check_pair_status(p))
4584                                diff_flush_patch(p, options);
4585                }
4586        }
4587
4588        if (output_format & DIFF_FORMAT_CALLBACK)
4589                options->format_callback(q, options, options->format_callback_data);
4590
4591        for (i = 0; i < q->nr; i++)
4592                diff_free_filepair(q->queue[i]);
4593free_queue:
4594        free(q->queue);
4595        DIFF_QUEUE_CLEAR(q);
4596        if (options->close_file)
4597                fclose(options->file);
4598
4599        /*
4600         * Report the content-level differences with HAS_CHANGES;
4601         * diff_addremove/diff_change does not set the bit when
4602         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4603         */
4604        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4605                if (options->found_changes)
4606                        DIFF_OPT_SET(options, HAS_CHANGES);
4607                else
4608                        DIFF_OPT_CLR(options, HAS_CHANGES);
4609        }
4610}
4611
4612static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
4613{
4614        return (((p->status == DIFF_STATUS_MODIFIED) &&
4615                 ((p->score &&
4616                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
4617                  (!p->score &&
4618                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
4619                ((p->status != DIFF_STATUS_MODIFIED) &&
4620                 filter_bit_tst(p->status, options)));
4621}
4622
4623static void diffcore_apply_filter(struct diff_options *options)
4624{
4625        int i;
4626        struct diff_queue_struct *q = &diff_queued_diff;
4627        struct diff_queue_struct outq;
4628
4629        DIFF_QUEUE_CLEAR(&outq);
4630
4631        if (!options->filter)
4632                return;
4633
4634        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
4635                int found;
4636                for (i = found = 0; !found && i < q->nr; i++) {
4637                        if (match_filter(options, q->queue[i]))
4638                                found++;
4639                }
4640                if (found)
4641                        return;
4642
4643                /* otherwise we will clear the whole queue
4644                 * by copying the empty outq at the end of this
4645                 * function, but first clear the current entries
4646                 * in the queue.
4647                 */
4648                for (i = 0; i < q->nr; i++)
4649                        diff_free_filepair(q->queue[i]);
4650        }
4651        else {
4652                /* Only the matching ones */
4653                for (i = 0; i < q->nr; i++) {
4654                        struct diff_filepair *p = q->queue[i];
4655                        if (match_filter(options, p))
4656                                diff_q(&outq, p);
4657                        else
4658                                diff_free_filepair(p);
4659                }
4660        }
4661        free(q->queue);
4662        *q = outq;
4663}
4664
4665/* Check whether two filespecs with the same mode and size are identical */
4666static int diff_filespec_is_identical(struct diff_filespec *one,
4667                                      struct diff_filespec *two)
4668{
4669        if (S_ISGITLINK(one->mode))
4670                return 0;
4671        if (diff_populate_filespec(one, 0))
4672                return 0;
4673        if (diff_populate_filespec(two, 0))
4674                return 0;
4675        return !memcmp(one->data, two->data, one->size);
4676}
4677
4678static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4679{
4680        int i;
4681        struct diff_queue_struct *q = &diff_queued_diff;
4682        struct diff_queue_struct outq;
4683        DIFF_QUEUE_CLEAR(&outq);
4684
4685        for (i = 0; i < q->nr; i++) {
4686                struct diff_filepair *p = q->queue[i];
4687
4688                /*
4689                 * 1. Entries that come from stat info dirtiness
4690                 *    always have both sides (iow, not create/delete),
4691                 *    one side of the object name is unknown, with
4692                 *    the same mode and size.  Keep the ones that
4693                 *    do not match these criteria.  They have real
4694                 *    differences.
4695                 *
4696                 * 2. At this point, the file is known to be modified,
4697                 *    with the same mode and size, and the object
4698                 *    name of one side is unknown.  Need to inspect
4699                 *    the identical contents.
4700                 */
4701                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4702                    !DIFF_FILE_VALID(p->two) ||
4703                    (p->one->sha1_valid && p->two->sha1_valid) ||
4704                    (p->one->mode != p->two->mode) ||
4705                    diff_populate_filespec(p->one, 1) ||
4706                    diff_populate_filespec(p->two, 1) ||
4707                    (p->one->size != p->two->size) ||
4708                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4709                        diff_q(&outq, p);
4710                else {
4711                        /*
4712                         * The caller can subtract 1 from skip_stat_unmatch
4713                         * to determine how many paths were dirty only
4714                         * due to stat info mismatch.
4715                         */
4716                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4717                                diffopt->skip_stat_unmatch++;
4718                        diff_free_filepair(p);
4719                }
4720        }
4721        free(q->queue);
4722        *q = outq;
4723}
4724
4725static int diffnamecmp(const void *a_, const void *b_)
4726{
4727        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4728        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4729        const char *name_a, *name_b;
4730
4731        name_a = a->one ? a->one->path : a->two->path;
4732        name_b = b->one ? b->one->path : b->two->path;
4733        return strcmp(name_a, name_b);
4734}
4735
4736void diffcore_fix_diff_index(struct diff_options *options)
4737{
4738        struct diff_queue_struct *q = &diff_queued_diff;
4739        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4740}
4741
4742void diffcore_std(struct diff_options *options)
4743{
4744        if (options->skip_stat_unmatch)
4745                diffcore_skip_stat_unmatch(options);
4746        if (!options->found_follow) {
4747                /* See try_to_follow_renames() in tree-diff.c */
4748                if (options->break_opt != -1)
4749                        diffcore_break(options->break_opt);
4750                if (options->detect_rename)
4751                        diffcore_rename(options);
4752                if (options->break_opt != -1)
4753                        diffcore_merge_broken();
4754        }
4755        if (options->pickaxe)
4756                diffcore_pickaxe(options);
4757        if (options->orderfile)
4758                diffcore_order(options->orderfile);
4759        if (!options->found_follow)
4760                /* See try_to_follow_renames() in tree-diff.c */
4761                diff_resolve_rename_copy();
4762        diffcore_apply_filter(options);
4763
4764        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4765                DIFF_OPT_SET(options, HAS_CHANGES);
4766        else
4767                DIFF_OPT_CLR(options, HAS_CHANGES);
4768
4769        options->found_follow = 0;
4770}
4771
4772int diff_result_code(struct diff_options *opt, int status)
4773{
4774        int result = 0;
4775
4776        diff_warn_rename_limit("diff.renameLimit",
4777                               opt->needed_rename_limit,
4778                               opt->degraded_cc_to_c);
4779        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4780            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4781                return status;
4782        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4783            DIFF_OPT_TST(opt, HAS_CHANGES))
4784                result |= 01;
4785        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4786            DIFF_OPT_TST(opt, CHECK_FAILED))
4787                result |= 02;
4788        return result;
4789}
4790
4791int diff_can_quit_early(struct diff_options *opt)
4792{
4793        return (DIFF_OPT_TST(opt, QUICK) &&
4794                !opt->filter &&
4795                DIFF_OPT_TST(opt, HAS_CHANGES));
4796}
4797
4798/*
4799 * Shall changes to this submodule be ignored?
4800 *
4801 * Submodule changes can be configured to be ignored separately for each path,
4802 * but that configuration can be overridden from the command line.
4803 */
4804static int is_submodule_ignored(const char *path, struct diff_options *options)
4805{
4806        int ignored = 0;
4807        unsigned orig_flags = options->flags;
4808        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4809                set_diffopt_flags_from_submodule_config(options, path);
4810        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4811                ignored = 1;
4812        options->flags = orig_flags;
4813        return ignored;
4814}
4815
4816void diff_addremove(struct diff_options *options,
4817                    int addremove, unsigned mode,
4818                    const unsigned char *sha1,
4819                    int sha1_valid,
4820                    const char *concatpath, unsigned dirty_submodule)
4821{
4822        struct diff_filespec *one, *two;
4823
4824        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4825                return;
4826
4827        /* This may look odd, but it is a preparation for
4828         * feeding "there are unchanged files which should
4829         * not produce diffs, but when you are doing copy
4830         * detection you would need them, so here they are"
4831         * entries to the diff-core.  They will be prefixed
4832         * with something like '=' or '*' (I haven't decided
4833         * which but should not make any difference).
4834         * Feeding the same new and old to diff_change()
4835         * also has the same effect.
4836         * Before the final output happens, they are pruned after
4837         * merged into rename/copy pairs as appropriate.
4838         */
4839        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4840                addremove = (addremove == '+' ? '-' :
4841                             addremove == '-' ? '+' : addremove);
4842
4843        if (options->prefix &&
4844            strncmp(concatpath, options->prefix, options->prefix_length))
4845                return;
4846
4847        one = alloc_filespec(concatpath);
4848        two = alloc_filespec(concatpath);
4849
4850        if (addremove != '+')
4851                fill_filespec(one, sha1, sha1_valid, mode);
4852        if (addremove != '-') {
4853                fill_filespec(two, sha1, sha1_valid, mode);
4854                two->dirty_submodule = dirty_submodule;
4855        }
4856
4857        diff_queue(&diff_queued_diff, one, two);
4858        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4859                DIFF_OPT_SET(options, HAS_CHANGES);
4860}
4861
4862void diff_change(struct diff_options *options,
4863                 unsigned old_mode, unsigned new_mode,
4864                 const unsigned char *old_sha1,
4865                 const unsigned char *new_sha1,
4866                 int old_sha1_valid, int new_sha1_valid,
4867                 const char *concatpath,
4868                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4869{
4870        struct diff_filespec *one, *two;
4871
4872        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4873            is_submodule_ignored(concatpath, options))
4874                return;
4875
4876        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4877                unsigned tmp;
4878                const unsigned char *tmp_c;
4879                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4880                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4881                tmp = old_sha1_valid; old_sha1_valid = new_sha1_valid;
4882                        new_sha1_valid = tmp;
4883                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4884                        new_dirty_submodule = tmp;
4885        }
4886
4887        if (options->prefix &&
4888            strncmp(concatpath, options->prefix, options->prefix_length))
4889                return;
4890
4891        one = alloc_filespec(concatpath);
4892        two = alloc_filespec(concatpath);
4893        fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
4894        fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
4895        one->dirty_submodule = old_dirty_submodule;
4896        two->dirty_submodule = new_dirty_submodule;
4897
4898        diff_queue(&diff_queued_diff, one, two);
4899        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4900                DIFF_OPT_SET(options, HAS_CHANGES);
4901}
4902
4903struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4904{
4905        struct diff_filepair *pair;
4906        struct diff_filespec *one, *two;
4907
4908        if (options->prefix &&
4909            strncmp(path, options->prefix, options->prefix_length))
4910                return NULL;
4911
4912        one = alloc_filespec(path);
4913        two = alloc_filespec(path);
4914        pair = diff_queue(&diff_queued_diff, one, two);
4915        pair->is_unmerged = 1;
4916        return pair;
4917}
4918
4919static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4920                size_t *outsize)
4921{
4922        struct diff_tempfile *temp;
4923        const char *argv[3];
4924        const char **arg = argv;
4925        struct child_process child;
4926        struct strbuf buf = STRBUF_INIT;
4927        int err = 0;
4928
4929        temp = prepare_temp_file(spec->path, spec);
4930        *arg++ = pgm;
4931        *arg++ = temp->name;
4932        *arg = NULL;
4933
4934        memset(&child, 0, sizeof(child));
4935        child.use_shell = 1;
4936        child.argv = argv;
4937        child.out = -1;
4938        if (start_command(&child)) {
4939                remove_tempfile();
4940                return NULL;
4941        }
4942
4943        if (strbuf_read(&buf, child.out, 0) < 0)
4944                err = error("error reading from textconv command '%s'", pgm);
4945        close(child.out);
4946
4947        if (finish_command(&child) || err) {
4948                strbuf_release(&buf);
4949                remove_tempfile();
4950                return NULL;
4951        }
4952        remove_tempfile();
4953
4954        return strbuf_detach(&buf, outsize);
4955}
4956
4957size_t fill_textconv(struct userdiff_driver *driver,
4958                     struct diff_filespec *df,
4959                     char **outbuf)
4960{
4961        size_t size;
4962
4963        if (!driver || !driver->textconv) {
4964                if (!DIFF_FILE_VALID(df)) {
4965                        *outbuf = "";
4966                        return 0;
4967                }
4968                if (diff_populate_filespec(df, 0))
4969                        die("unable to read files to diff");
4970                *outbuf = df->data;
4971                return df->size;
4972        }
4973
4974        if (driver->textconv_cache && df->sha1_valid) {
4975                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4976                                          &size);
4977                if (*outbuf)
4978                        return size;
4979        }
4980
4981        *outbuf = run_textconv(driver->textconv, df, &size);
4982        if (!*outbuf)
4983                die("unable to read files to diff");
4984
4985        if (driver->textconv_cache && df->sha1_valid) {
4986                /* ignore errors, as we might be in a readonly repository */
4987                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4988                                size);
4989                /*
4990                 * we could save up changes and flush them all at the end,
4991                 * but we would need an extra call after all diffing is done.
4992                 * Since generating a cache entry is the slow path anyway,
4993                 * this extra overhead probably isn't a big deal.
4994                 */
4995                notes_cache_write(driver->textconv_cache);
4996        }
4997
4998        return size;
4999}
5000
5001void setup_diff_pager(struct diff_options *opt)
5002{
5003        /*
5004         * If the user asked for our exit code, then either they want --quiet
5005         * or --exit-code. We should definitely not bother with a pager in the
5006         * former case, as we will generate no output. Since we still properly
5007         * report our exit code even when a pager is run, we _could_ run a
5008         * pager with --exit-code. But since we have not done so historically,
5009         * and because it is easy to find people oneline advising "git diff
5010         * --exit-code" in hooks and other scripts, we do not do so.
5011         */
5012        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5013            check_pager_config("diff") != 0)
5014                setup_pager();
5015}