diff.con commit t/t2021-checkout-last: "checkout -" should work after a rebase finishes (89f2fea)
   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 ? name_b : name_a);
 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 = add + del;
1687
1688                        total = scale_linear(add + del, graph_width, max_change);
1689                        if (total < 2 && add && del)
1690                                /* width >= 2 due to the sanity check */
1691                                total = 2;
1692                        if (add < del) {
1693                                add = scale_linear(add, graph_width, max_change);
1694                                del = total - add;
1695                        } else {
1696                                del = scale_linear(del, graph_width, max_change);
1697                                add = total - del;
1698                        }
1699                }
1700                fprintf(options->file, "%s", line_prefix);
1701                show_name(options->file, prefix, name, len);
1702                fprintf(options->file, " %*"PRIuMAX"%s",
1703                        number_width, added + deleted,
1704                        added + deleted ? " " : "");
1705                show_graph(options->file, '+', add, add_c, reset);
1706                show_graph(options->file, '-', del, del_c, reset);
1707                fprintf(options->file, "\n");
1708        }
1709
1710        for (i = 0; i < data->nr; i++) {
1711                struct diffstat_file *file = data->files[i];
1712                uintmax_t added = file->added;
1713                uintmax_t deleted = file->deleted;
1714
1715                if (file->is_unmerged ||
1716                    (!file->is_interesting && (added + deleted == 0))) {
1717                        total_files--;
1718                        continue;
1719                }
1720
1721                if (!file->is_binary) {
1722                        adds += added;
1723                        dels += deleted;
1724                }
1725                if (i < count)
1726                        continue;
1727                if (!extra_shown)
1728                        fprintf(options->file, "%s ...\n", line_prefix);
1729                extra_shown = 1;
1730        }
1731        fprintf(options->file, "%s", line_prefix);
1732        print_stat_summary(options->file, total_files, adds, dels);
1733}
1734
1735static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1736{
1737        int i, adds = 0, dels = 0, total_files = data->nr;
1738
1739        if (data->nr == 0)
1740                return;
1741
1742        for (i = 0; i < data->nr; i++) {
1743                int added = data->files[i]->added;
1744                int deleted= data->files[i]->deleted;
1745
1746                if (data->files[i]->is_unmerged ||
1747                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
1748                        total_files--;
1749                } else if (!data->files[i]->is_binary) { /* don't count bytes */
1750                        adds += added;
1751                        dels += deleted;
1752                }
1753        }
1754        fprintf(options->file, "%s", diff_line_prefix(options));
1755        print_stat_summary(options->file, total_files, adds, dels);
1756}
1757
1758static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1759{
1760        int i;
1761
1762        if (data->nr == 0)
1763                return;
1764
1765        for (i = 0; i < data->nr; i++) {
1766                struct diffstat_file *file = data->files[i];
1767
1768                fprintf(options->file, "%s", diff_line_prefix(options));
1769
1770                if (file->is_binary)
1771                        fprintf(options->file, "-\t-\t");
1772                else
1773                        fprintf(options->file,
1774                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1775                                file->added, file->deleted);
1776                if (options->line_termination) {
1777                        fill_print_name(file);
1778                        if (!file->is_renamed)
1779                                write_name_quoted(file->name, options->file,
1780                                                  options->line_termination);
1781                        else {
1782                                fputs(file->print_name, options->file);
1783                                putc(options->line_termination, options->file);
1784                        }
1785                } else {
1786                        if (file->is_renamed) {
1787                                putc('\0', options->file);
1788                                write_name_quoted(file->from_name, options->file, '\0');
1789                        }
1790                        write_name_quoted(file->name, options->file, '\0');
1791                }
1792        }
1793}
1794
1795struct dirstat_file {
1796        const char *name;
1797        unsigned long changed;
1798};
1799
1800struct dirstat_dir {
1801        struct dirstat_file *files;
1802        int alloc, nr, permille, cumulative;
1803};
1804
1805static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1806                unsigned long changed, const char *base, int baselen)
1807{
1808        unsigned long this_dir = 0;
1809        unsigned int sources = 0;
1810        const char *line_prefix = diff_line_prefix(opt);
1811
1812        while (dir->nr) {
1813                struct dirstat_file *f = dir->files;
1814                int namelen = strlen(f->name);
1815                unsigned long this;
1816                char *slash;
1817
1818                if (namelen < baselen)
1819                        break;
1820                if (memcmp(f->name, base, baselen))
1821                        break;
1822                slash = strchr(f->name + baselen, '/');
1823                if (slash) {
1824                        int newbaselen = slash + 1 - f->name;
1825                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1826                        sources++;
1827                } else {
1828                        this = f->changed;
1829                        dir->files++;
1830                        dir->nr--;
1831                        sources += 2;
1832                }
1833                this_dir += this;
1834        }
1835
1836        /*
1837         * We don't report dirstat's for
1838         *  - the top level
1839         *  - or cases where everything came from a single directory
1840         *    under this directory (sources == 1).
1841         */
1842        if (baselen && sources != 1) {
1843                if (this_dir) {
1844                        int permille = this_dir * 1000 / changed;
1845                        if (permille >= dir->permille) {
1846                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1847                                        permille / 10, permille % 10, baselen, base);
1848                                if (!dir->cumulative)
1849                                        return 0;
1850                        }
1851                }
1852        }
1853        return this_dir;
1854}
1855
1856static int dirstat_compare(const void *_a, const void *_b)
1857{
1858        const struct dirstat_file *a = _a;
1859        const struct dirstat_file *b = _b;
1860        return strcmp(a->name, b->name);
1861}
1862
1863static void show_dirstat(struct diff_options *options)
1864{
1865        int i;
1866        unsigned long changed;
1867        struct dirstat_dir dir;
1868        struct diff_queue_struct *q = &diff_queued_diff;
1869
1870        dir.files = NULL;
1871        dir.alloc = 0;
1872        dir.nr = 0;
1873        dir.permille = options->dirstat_permille;
1874        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1875
1876        changed = 0;
1877        for (i = 0; i < q->nr; i++) {
1878                struct diff_filepair *p = q->queue[i];
1879                const char *name;
1880                unsigned long copied, added, damage;
1881                int content_changed;
1882
1883                name = p->two->path ? p->two->path : p->one->path;
1884
1885                if (p->one->sha1_valid && p->two->sha1_valid)
1886                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1887                else
1888                        content_changed = 1;
1889
1890                if (!content_changed) {
1891                        /*
1892                         * The SHA1 has not changed, so pre-/post-content is
1893                         * identical. We can therefore skip looking at the
1894                         * file contents altogether.
1895                         */
1896                        damage = 0;
1897                        goto found_damage;
1898                }
1899
1900                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1901                        /*
1902                         * In --dirstat-by-file mode, we don't really need to
1903                         * look at the actual file contents at all.
1904                         * The fact that the SHA1 changed is enough for us to
1905                         * add this file to the list of results
1906                         * (with each file contributing equal damage).
1907                         */
1908                        damage = 1;
1909                        goto found_damage;
1910                }
1911
1912                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1913                        diff_populate_filespec(p->one, 0);
1914                        diff_populate_filespec(p->two, 0);
1915                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1916                                               &copied, &added);
1917                        diff_free_filespec_data(p->one);
1918                        diff_free_filespec_data(p->two);
1919                } else if (DIFF_FILE_VALID(p->one)) {
1920                        diff_populate_filespec(p->one, 1);
1921                        copied = added = 0;
1922                        diff_free_filespec_data(p->one);
1923                } else if (DIFF_FILE_VALID(p->two)) {
1924                        diff_populate_filespec(p->two, 1);
1925                        copied = 0;
1926                        added = p->two->size;
1927                        diff_free_filespec_data(p->two);
1928                } else
1929                        continue;
1930
1931                /*
1932                 * Original minus copied is the removed material,
1933                 * added is the new material.  They are both damages
1934                 * made to the preimage.
1935                 * If the resulting damage is zero, we know that
1936                 * diffcore_count_changes() considers the two entries to
1937                 * be identical, but since content_changed is true, we
1938                 * know that there must have been _some_ kind of change,
1939                 * so we force all entries to have damage > 0.
1940                 */
1941                damage = (p->one->size - copied) + added;
1942                if (!damage)
1943                        damage = 1;
1944
1945found_damage:
1946                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1947                dir.files[dir.nr].name = name;
1948                dir.files[dir.nr].changed = damage;
1949                changed += damage;
1950                dir.nr++;
1951        }
1952
1953        /* This can happen even with many files, if everything was renames */
1954        if (!changed)
1955                return;
1956
1957        /* Show all directories with more than x% of the changes */
1958        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1959        gather_dirstat(options, &dir, changed, "", 0);
1960}
1961
1962static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1963{
1964        int i;
1965        unsigned long changed;
1966        struct dirstat_dir dir;
1967
1968        if (data->nr == 0)
1969                return;
1970
1971        dir.files = NULL;
1972        dir.alloc = 0;
1973        dir.nr = 0;
1974        dir.permille = options->dirstat_permille;
1975        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1976
1977        changed = 0;
1978        for (i = 0; i < data->nr; i++) {
1979                struct diffstat_file *file = data->files[i];
1980                unsigned long damage = file->added + file->deleted;
1981                if (file->is_binary)
1982                        /*
1983                         * binary files counts bytes, not lines. Must find some
1984                         * way to normalize binary bytes vs. textual lines.
1985                         * The following heuristic assumes that there are 64
1986                         * bytes per "line".
1987                         * This is stupid and ugly, but very cheap...
1988                         */
1989                        damage = (damage + 63) / 64;
1990                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1991                dir.files[dir.nr].name = file->name;
1992                dir.files[dir.nr].changed = damage;
1993                changed += damage;
1994                dir.nr++;
1995        }
1996
1997        /* This can happen even with many files, if everything was renames */
1998        if (!changed)
1999                return;
2000
2001        /* Show all directories with more than x% of the changes */
2002        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
2003        gather_dirstat(options, &dir, changed, "", 0);
2004}
2005
2006static void free_diffstat_info(struct diffstat_t *diffstat)
2007{
2008        int i;
2009        for (i = 0; i < diffstat->nr; i++) {
2010                struct diffstat_file *f = diffstat->files[i];
2011                if (f->name != f->print_name)
2012                        free(f->print_name);
2013                free(f->name);
2014                free(f->from_name);
2015                free(f);
2016        }
2017        free(diffstat->files);
2018}
2019
2020struct checkdiff_t {
2021        const char *filename;
2022        int lineno;
2023        int conflict_marker_size;
2024        struct diff_options *o;
2025        unsigned ws_rule;
2026        unsigned status;
2027};
2028
2029static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2030{
2031        char firstchar;
2032        int cnt;
2033
2034        if (len < marker_size + 1)
2035                return 0;
2036        firstchar = line[0];
2037        switch (firstchar) {
2038        case '=': case '>': case '<': case '|':
2039                break;
2040        default:
2041                return 0;
2042        }
2043        for (cnt = 1; cnt < marker_size; cnt++)
2044                if (line[cnt] != firstchar)
2045                        return 0;
2046        /* line[1] thru line[marker_size-1] are same as firstchar */
2047        if (len < marker_size + 1 || !isspace(line[marker_size]))
2048                return 0;
2049        return 1;
2050}
2051
2052static void checkdiff_consume(void *priv, char *line, unsigned long len)
2053{
2054        struct checkdiff_t *data = priv;
2055        int marker_size = data->conflict_marker_size;
2056        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2057        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2058        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2059        char *err;
2060        const char *line_prefix;
2061
2062        assert(data->o);
2063        line_prefix = diff_line_prefix(data->o);
2064
2065        if (line[0] == '+') {
2066                unsigned bad;
2067                data->lineno++;
2068                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2069                        data->status |= 1;
2070                        fprintf(data->o->file,
2071                                "%s%s:%d: leftover conflict marker\n",
2072                                line_prefix, data->filename, data->lineno);
2073                }
2074                bad = ws_check(line + 1, len - 1, data->ws_rule);
2075                if (!bad)
2076                        return;
2077                data->status |= bad;
2078                err = whitespace_error_string(bad);
2079                fprintf(data->o->file, "%s%s:%d: %s.\n",
2080                        line_prefix, data->filename, data->lineno, err);
2081                free(err);
2082                emit_line(data->o, set, reset, line, 1);
2083                ws_check_emit(line + 1, len - 1, data->ws_rule,
2084                              data->o->file, set, reset, ws);
2085        } else if (line[0] == ' ') {
2086                data->lineno++;
2087        } else if (line[0] == '@') {
2088                char *plus = strchr(line, '+');
2089                if (plus)
2090                        data->lineno = strtol(plus, NULL, 10) - 1;
2091                else
2092                        die("invalid diff");
2093        }
2094}
2095
2096static unsigned char *deflate_it(char *data,
2097                                 unsigned long size,
2098                                 unsigned long *result_size)
2099{
2100        int bound;
2101        unsigned char *deflated;
2102        git_zstream stream;
2103
2104        memset(&stream, 0, sizeof(stream));
2105        git_deflate_init(&stream, zlib_compression_level);
2106        bound = git_deflate_bound(&stream, size);
2107        deflated = xmalloc(bound);
2108        stream.next_out = deflated;
2109        stream.avail_out = bound;
2110
2111        stream.next_in = (unsigned char *)data;
2112        stream.avail_in = size;
2113        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2114                ; /* nothing */
2115        git_deflate_end(&stream);
2116        *result_size = stream.total_out;
2117        return deflated;
2118}
2119
2120static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two,
2121                                  const char *prefix)
2122{
2123        void *cp;
2124        void *delta;
2125        void *deflated;
2126        void *data;
2127        unsigned long orig_size;
2128        unsigned long delta_size;
2129        unsigned long deflate_size;
2130        unsigned long data_size;
2131
2132        /* We could do deflated delta, or we could do just deflated two,
2133         * whichever is smaller.
2134         */
2135        delta = NULL;
2136        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2137        if (one->size && two->size) {
2138                delta = diff_delta(one->ptr, one->size,
2139                                   two->ptr, two->size,
2140                                   &delta_size, deflate_size);
2141                if (delta) {
2142                        void *to_free = delta;
2143                        orig_size = delta_size;
2144                        delta = deflate_it(delta, delta_size, &delta_size);
2145                        free(to_free);
2146                }
2147        }
2148
2149        if (delta && delta_size < deflate_size) {
2150                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2151                free(deflated);
2152                data = delta;
2153                data_size = delta_size;
2154        }
2155        else {
2156                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2157                free(delta);
2158                data = deflated;
2159                data_size = deflate_size;
2160        }
2161
2162        /* emit data encoded in base85 */
2163        cp = data;
2164        while (data_size) {
2165                int bytes = (52 < data_size) ? 52 : data_size;
2166                char line[70];
2167                data_size -= bytes;
2168                if (bytes <= 26)
2169                        line[0] = bytes + 'A' - 1;
2170                else
2171                        line[0] = bytes - 26 + 'a' - 1;
2172                encode_85(line + 1, cp, bytes);
2173                cp = (char *) cp + bytes;
2174                fprintf(file, "%s", prefix);
2175                fputs(line, file);
2176                fputc('\n', file);
2177        }
2178        fprintf(file, "%s\n", prefix);
2179        free(data);
2180}
2181
2182static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two,
2183                             const char *prefix)
2184{
2185        fprintf(file, "%sGIT binary patch\n", prefix);
2186        emit_binary_diff_body(file, one, two, prefix);
2187        emit_binary_diff_body(file, two, one, prefix);
2188}
2189
2190int diff_filespec_is_binary(struct diff_filespec *one)
2191{
2192        if (one->is_binary == -1) {
2193                diff_filespec_load_driver(one);
2194                if (one->driver->binary != -1)
2195                        one->is_binary = one->driver->binary;
2196                else {
2197                        if (!one->data && DIFF_FILE_VALID(one))
2198                                diff_populate_filespec(one, 0);
2199                        if (one->data)
2200                                one->is_binary = buffer_is_binary(one->data,
2201                                                one->size);
2202                        if (one->is_binary == -1)
2203                                one->is_binary = 0;
2204                }
2205        }
2206        return one->is_binary;
2207}
2208
2209static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2210{
2211        diff_filespec_load_driver(one);
2212        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2213}
2214
2215void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2216{
2217        if (!options->a_prefix)
2218                options->a_prefix = a;
2219        if (!options->b_prefix)
2220                options->b_prefix = b;
2221}
2222
2223struct userdiff_driver *get_textconv(struct diff_filespec *one)
2224{
2225        if (!DIFF_FILE_VALID(one))
2226                return NULL;
2227
2228        diff_filespec_load_driver(one);
2229        return userdiff_get_textconv(one->driver);
2230}
2231
2232static void builtin_diff(const char *name_a,
2233                         const char *name_b,
2234                         struct diff_filespec *one,
2235                         struct diff_filespec *two,
2236                         const char *xfrm_msg,
2237                         int must_show_header,
2238                         struct diff_options *o,
2239                         int complete_rewrite)
2240{
2241        mmfile_t mf1, mf2;
2242        const char *lbl[2];
2243        char *a_one, *b_two;
2244        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
2245        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2246        const char *a_prefix, *b_prefix;
2247        struct userdiff_driver *textconv_one = NULL;
2248        struct userdiff_driver *textconv_two = NULL;
2249        struct strbuf header = STRBUF_INIT;
2250        const char *line_prefix = diff_line_prefix(o);
2251
2252        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2253                        (!one->mode || S_ISGITLINK(one->mode)) &&
2254                        (!two->mode || S_ISGITLINK(two->mode))) {
2255                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2256                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2257                show_submodule_summary(o->file, one ? one->path : two->path,
2258                                line_prefix,
2259                                one->sha1, two->sha1, two->dirty_submodule,
2260                                meta, del, add, reset);
2261                return;
2262        }
2263
2264        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2265                textconv_one = get_textconv(one);
2266                textconv_two = get_textconv(two);
2267        }
2268
2269        diff_set_mnemonic_prefix(o, "a/", "b/");
2270        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2271                a_prefix = o->b_prefix;
2272                b_prefix = o->a_prefix;
2273        } else {
2274                a_prefix = o->a_prefix;
2275                b_prefix = o->b_prefix;
2276        }
2277
2278        /* Never use a non-valid filename anywhere if at all possible */
2279        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2280        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2281
2282        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2283        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2284        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2285        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2286        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
2287        if (lbl[0][0] == '/') {
2288                /* /dev/null */
2289                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
2290                if (xfrm_msg)
2291                        strbuf_addstr(&header, xfrm_msg);
2292                must_show_header = 1;
2293        }
2294        else if (lbl[1][0] == '/') {
2295                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
2296                if (xfrm_msg)
2297                        strbuf_addstr(&header, xfrm_msg);
2298                must_show_header = 1;
2299        }
2300        else {
2301                if (one->mode != two->mode) {
2302                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
2303                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
2304                        must_show_header = 1;
2305                }
2306                if (xfrm_msg)
2307                        strbuf_addstr(&header, xfrm_msg);
2308
2309                /*
2310                 * we do not run diff between different kind
2311                 * of objects.
2312                 */
2313                if ((one->mode ^ two->mode) & S_IFMT)
2314                        goto free_ab_and_return;
2315                if (complete_rewrite &&
2316                    (textconv_one || !diff_filespec_is_binary(one)) &&
2317                    (textconv_two || !diff_filespec_is_binary(two))) {
2318                        fprintf(o->file, "%s", header.buf);
2319                        strbuf_reset(&header);
2320                        emit_rewrite_diff(name_a, name_b, one, two,
2321                                                textconv_one, textconv_two, o);
2322                        o->found_changes = 1;
2323                        goto free_ab_and_return;
2324                }
2325        }
2326
2327        if (o->irreversible_delete && lbl[1][0] == '/') {
2328                fprintf(o->file, "%s", header.buf);
2329                strbuf_reset(&header);
2330                goto free_ab_and_return;
2331        } else if (!DIFF_OPT_TST(o, TEXT) &&
2332            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2333              (!textconv_two && diff_filespec_is_binary(two)) )) {
2334                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2335                        die("unable to read files to diff");
2336                /* Quite common confusing case */
2337                if (mf1.size == mf2.size &&
2338                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2339                        if (must_show_header)
2340                                fprintf(o->file, "%s", header.buf);
2341                        goto free_ab_and_return;
2342                }
2343                fprintf(o->file, "%s", header.buf);
2344                strbuf_reset(&header);
2345                if (DIFF_OPT_TST(o, BINARY))
2346                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2347                else
2348                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2349                                line_prefix, lbl[0], lbl[1]);
2350                o->found_changes = 1;
2351        } else {
2352                /* Crazy xdl interfaces.. */
2353                const char *diffopts = getenv("GIT_DIFF_OPTS");
2354                xpparam_t xpp;
2355                xdemitconf_t xecfg;
2356                struct emit_callback ecbdata;
2357                const struct userdiff_funcname *pe;
2358
2359                if (must_show_header) {
2360                        fprintf(o->file, "%s", header.buf);
2361                        strbuf_reset(&header);
2362                }
2363
2364                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2365                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2366
2367                pe = diff_funcname_pattern(one);
2368                if (!pe)
2369                        pe = diff_funcname_pattern(two);
2370
2371                memset(&xpp, 0, sizeof(xpp));
2372                memset(&xecfg, 0, sizeof(xecfg));
2373                memset(&ecbdata, 0, sizeof(ecbdata));
2374                ecbdata.label_path = lbl;
2375                ecbdata.color_diff = want_color(o->use_color);
2376                ecbdata.found_changesp = &o->found_changes;
2377                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2378                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2379                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2380                ecbdata.opt = o;
2381                ecbdata.header = header.len ? &header : NULL;
2382                xpp.flags = o->xdl_opts;
2383                xecfg.ctxlen = o->context;
2384                xecfg.interhunkctxlen = o->interhunkcontext;
2385                xecfg.flags = XDL_EMIT_FUNCNAMES;
2386                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2387                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2388                if (pe)
2389                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2390                if (!diffopts)
2391                        ;
2392                else if (!prefixcmp(diffopts, "--unified="))
2393                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2394                else if (!prefixcmp(diffopts, "-u"))
2395                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2396                if (o->word_diff)
2397                        init_diff_words_data(&ecbdata, o, one, two);
2398                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2399                              &xpp, &xecfg);
2400                if (o->word_diff)
2401                        free_diff_words_data(&ecbdata);
2402                if (textconv_one)
2403                        free(mf1.ptr);
2404                if (textconv_two)
2405                        free(mf2.ptr);
2406                xdiff_clear_find_func(&xecfg);
2407        }
2408
2409 free_ab_and_return:
2410        strbuf_release(&header);
2411        diff_free_filespec_data(one);
2412        diff_free_filespec_data(two);
2413        free(a_one);
2414        free(b_two);
2415        return;
2416}
2417
2418static void builtin_diffstat(const char *name_a, const char *name_b,
2419                             struct diff_filespec *one,
2420                             struct diff_filespec *two,
2421                             struct diffstat_t *diffstat,
2422                             struct diff_options *o,
2423                             struct diff_filepair *p)
2424{
2425        mmfile_t mf1, mf2;
2426        struct diffstat_file *data;
2427        int same_contents;
2428        int complete_rewrite = 0;
2429
2430        if (!DIFF_PAIR_UNMERGED(p)) {
2431                if (p->status == DIFF_STATUS_MODIFIED && p->score)
2432                        complete_rewrite = 1;
2433        }
2434
2435        data = diffstat_add(diffstat, name_a, name_b);
2436        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
2437
2438        if (!one || !two) {
2439                data->is_unmerged = 1;
2440                return;
2441        }
2442
2443        same_contents = !hashcmp(one->sha1, two->sha1);
2444
2445        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2446                data->is_binary = 1;
2447                if (same_contents) {
2448                        data->added = 0;
2449                        data->deleted = 0;
2450                } else {
2451                        data->added = diff_filespec_size(two);
2452                        data->deleted = diff_filespec_size(one);
2453                }
2454        }
2455
2456        else if (complete_rewrite) {
2457                diff_populate_filespec(one, 0);
2458                diff_populate_filespec(two, 0);
2459                data->deleted = count_lines(one->data, one->size);
2460                data->added = count_lines(two->data, two->size);
2461        }
2462
2463        else if (!same_contents) {
2464                /* Crazy xdl interfaces.. */
2465                xpparam_t xpp;
2466                xdemitconf_t xecfg;
2467
2468                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2469                        die("unable to read files to diff");
2470
2471                memset(&xpp, 0, sizeof(xpp));
2472                memset(&xecfg, 0, sizeof(xecfg));
2473                xpp.flags = o->xdl_opts;
2474                xecfg.ctxlen = o->context;
2475                xecfg.interhunkctxlen = o->interhunkcontext;
2476                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2477                              &xpp, &xecfg);
2478        }
2479
2480        diff_free_filespec_data(one);
2481        diff_free_filespec_data(two);
2482}
2483
2484static void builtin_checkdiff(const char *name_a, const char *name_b,
2485                              const char *attr_path,
2486                              struct diff_filespec *one,
2487                              struct diff_filespec *two,
2488                              struct diff_options *o)
2489{
2490        mmfile_t mf1, mf2;
2491        struct checkdiff_t data;
2492
2493        if (!two)
2494                return;
2495
2496        memset(&data, 0, sizeof(data));
2497        data.filename = name_b ? name_b : name_a;
2498        data.lineno = 0;
2499        data.o = o;
2500        data.ws_rule = whitespace_rule(attr_path);
2501        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2502
2503        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2504                die("unable to read files to diff");
2505
2506        /*
2507         * All the other codepaths check both sides, but not checking
2508         * the "old" side here is deliberate.  We are checking the newly
2509         * introduced changes, and as long as the "new" side is text, we
2510         * can and should check what it introduces.
2511         */
2512        if (diff_filespec_is_binary(two))
2513                goto free_and_return;
2514        else {
2515                /* Crazy xdl interfaces.. */
2516                xpparam_t xpp;
2517                xdemitconf_t xecfg;
2518
2519                memset(&xpp, 0, sizeof(xpp));
2520                memset(&xecfg, 0, sizeof(xecfg));
2521                xecfg.ctxlen = 1; /* at least one context line */
2522                xpp.flags = 0;
2523                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2524                              &xpp, &xecfg);
2525
2526                if (data.ws_rule & WS_BLANK_AT_EOF) {
2527                        struct emit_callback ecbdata;
2528                        int blank_at_eof;
2529
2530                        ecbdata.ws_rule = data.ws_rule;
2531                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2532                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2533
2534                        if (blank_at_eof) {
2535                                static char *err;
2536                                if (!err)
2537                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2538                                fprintf(o->file, "%s:%d: %s.\n",
2539                                        data.filename, blank_at_eof, err);
2540                                data.status = 1; /* report errors */
2541                        }
2542                }
2543        }
2544 free_and_return:
2545        diff_free_filespec_data(one);
2546        diff_free_filespec_data(two);
2547        if (data.status)
2548                DIFF_OPT_SET(o, CHECK_FAILED);
2549}
2550
2551struct diff_filespec *alloc_filespec(const char *path)
2552{
2553        int namelen = strlen(path);
2554        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2555
2556        memset(spec, 0, sizeof(*spec));
2557        spec->path = (char *)(spec + 1);
2558        memcpy(spec->path, path, namelen+1);
2559        spec->count = 1;
2560        spec->is_binary = -1;
2561        return spec;
2562}
2563
2564void free_filespec(struct diff_filespec *spec)
2565{
2566        if (!--spec->count) {
2567                diff_free_filespec_data(spec);
2568                free(spec);
2569        }
2570}
2571
2572void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2573                   int sha1_valid, unsigned short mode)
2574{
2575        if (mode) {
2576                spec->mode = canon_mode(mode);
2577                hashcpy(spec->sha1, sha1);
2578                spec->sha1_valid = sha1_valid;
2579        }
2580}
2581
2582/*
2583 * Given a name and sha1 pair, if the index tells us the file in
2584 * the work tree has that object contents, return true, so that
2585 * prepare_temp_file() does not have to inflate and extract.
2586 */
2587static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2588{
2589        struct cache_entry *ce;
2590        struct stat st;
2591        int pos, len;
2592
2593        /*
2594         * We do not read the cache ourselves here, because the
2595         * benchmark with my previous version that always reads cache
2596         * shows that it makes things worse for diff-tree comparing
2597         * two linux-2.6 kernel trees in an already checked out work
2598         * tree.  This is because most diff-tree comparisons deal with
2599         * only a small number of files, while reading the cache is
2600         * expensive for a large project, and its cost outweighs the
2601         * savings we get by not inflating the object to a temporary
2602         * file.  Practically, this code only helps when we are used
2603         * by diff-cache --cached, which does read the cache before
2604         * calling us.
2605         */
2606        if (!active_cache)
2607                return 0;
2608
2609        /* We want to avoid the working directory if our caller
2610         * doesn't need the data in a normal file, this system
2611         * is rather slow with its stat/open/mmap/close syscalls,
2612         * and the object is contained in a pack file.  The pack
2613         * is probably already open and will be faster to obtain
2614         * the data through than the working directory.  Loose
2615         * objects however would tend to be slower as they need
2616         * to be individually opened and inflated.
2617         */
2618        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2619                return 0;
2620
2621        len = strlen(name);
2622        pos = cache_name_pos(name, len);
2623        if (pos < 0)
2624                return 0;
2625        ce = active_cache[pos];
2626
2627        /*
2628         * This is not the sha1 we are looking for, or
2629         * unreusable because it is not a regular file.
2630         */
2631        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2632                return 0;
2633
2634        /*
2635         * If ce is marked as "assume unchanged", there is no
2636         * guarantee that work tree matches what we are looking for.
2637         */
2638        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2639                return 0;
2640
2641        /*
2642         * If ce matches the file in the work tree, we can reuse it.
2643         */
2644        if (ce_uptodate(ce) ||
2645            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2646                return 1;
2647
2648        return 0;
2649}
2650
2651static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2652{
2653        int len;
2654        char *data = xmalloc(100), *dirty = "";
2655
2656        /* Are we looking at the work tree? */
2657        if (s->dirty_submodule)
2658                dirty = "-dirty";
2659
2660        len = snprintf(data, 100,
2661                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2662        s->data = data;
2663        s->size = len;
2664        s->should_free = 1;
2665        if (size_only) {
2666                s->data = NULL;
2667                free(data);
2668        }
2669        return 0;
2670}
2671
2672/*
2673 * While doing rename detection and pickaxe operation, we may need to
2674 * grab the data for the blob (or file) for our own in-core comparison.
2675 * diff_filespec has data and size fields for this purpose.
2676 */
2677int diff_populate_filespec(struct diff_filespec *s, int size_only)
2678{
2679        int err = 0;
2680        if (!DIFF_FILE_VALID(s))
2681                die("internal error: asking to populate invalid file.");
2682        if (S_ISDIR(s->mode))
2683                return -1;
2684
2685        if (s->data)
2686                return 0;
2687
2688        if (size_only && 0 < s->size)
2689                return 0;
2690
2691        if (S_ISGITLINK(s->mode))
2692                return diff_populate_gitlink(s, size_only);
2693
2694        if (!s->sha1_valid ||
2695            reuse_worktree_file(s->path, s->sha1, 0)) {
2696                struct strbuf buf = STRBUF_INIT;
2697                struct stat st;
2698                int fd;
2699
2700                if (lstat(s->path, &st) < 0) {
2701                        if (errno == ENOENT) {
2702                        err_empty:
2703                                err = -1;
2704                        empty:
2705                                s->data = (char *)"";
2706                                s->size = 0;
2707                                return err;
2708                        }
2709                }
2710                s->size = xsize_t(st.st_size);
2711                if (!s->size)
2712                        goto empty;
2713                if (S_ISLNK(st.st_mode)) {
2714                        struct strbuf sb = STRBUF_INIT;
2715
2716                        if (strbuf_readlink(&sb, s->path, s->size))
2717                                goto err_empty;
2718                        s->size = sb.len;
2719                        s->data = strbuf_detach(&sb, NULL);
2720                        s->should_free = 1;
2721                        return 0;
2722                }
2723                if (size_only)
2724                        return 0;
2725                fd = open(s->path, O_RDONLY);
2726                if (fd < 0)
2727                        goto err_empty;
2728                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2729                close(fd);
2730                s->should_munmap = 1;
2731
2732                /*
2733                 * Convert from working tree format to canonical git format
2734                 */
2735                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2736                        size_t size = 0;
2737                        munmap(s->data, s->size);
2738                        s->should_munmap = 0;
2739                        s->data = strbuf_detach(&buf, &size);
2740                        s->size = size;
2741                        s->should_free = 1;
2742                }
2743        }
2744        else {
2745                enum object_type type;
2746                if (size_only) {
2747                        type = sha1_object_info(s->sha1, &s->size);
2748                        if (type < 0)
2749                                die("unable to read %s", sha1_to_hex(s->sha1));
2750                } else {
2751                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2752                        if (!s->data)
2753                                die("unable to read %s", sha1_to_hex(s->sha1));
2754                        s->should_free = 1;
2755                }
2756        }
2757        return 0;
2758}
2759
2760void diff_free_filespec_blob(struct diff_filespec *s)
2761{
2762        if (s->should_free)
2763                free(s->data);
2764        else if (s->should_munmap)
2765                munmap(s->data, s->size);
2766
2767        if (s->should_free || s->should_munmap) {
2768                s->should_free = s->should_munmap = 0;
2769                s->data = NULL;
2770        }
2771}
2772
2773void diff_free_filespec_data(struct diff_filespec *s)
2774{
2775        diff_free_filespec_blob(s);
2776        free(s->cnt_data);
2777        s->cnt_data = NULL;
2778}
2779
2780static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2781                           void *blob,
2782                           unsigned long size,
2783                           const unsigned char *sha1,
2784                           int mode)
2785{
2786        int fd;
2787        struct strbuf buf = STRBUF_INIT;
2788        struct strbuf template = STRBUF_INIT;
2789        char *path_dup = xstrdup(path);
2790        const char *base = basename(path_dup);
2791
2792        /* Generate "XXXXXX_basename.ext" */
2793        strbuf_addstr(&template, "XXXXXX_");
2794        strbuf_addstr(&template, base);
2795
2796        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2797                        strlen(base) + 1);
2798        if (fd < 0)
2799                die_errno("unable to create temp-file");
2800        if (convert_to_working_tree(path,
2801                        (const char *)blob, (size_t)size, &buf)) {
2802                blob = buf.buf;
2803                size = buf.len;
2804        }
2805        if (write_in_full(fd, blob, size) != size)
2806                die_errno("unable to write temp-file");
2807        close(fd);
2808        temp->name = temp->tmp_path;
2809        strcpy(temp->hex, sha1_to_hex(sha1));
2810        temp->hex[40] = 0;
2811        sprintf(temp->mode, "%06o", mode);
2812        strbuf_release(&buf);
2813        strbuf_release(&template);
2814        free(path_dup);
2815}
2816
2817static struct diff_tempfile *prepare_temp_file(const char *name,
2818                struct diff_filespec *one)
2819{
2820        struct diff_tempfile *temp = claim_diff_tempfile();
2821
2822        if (!DIFF_FILE_VALID(one)) {
2823        not_a_valid_file:
2824                /* A '-' entry produces this for file-2, and
2825                 * a '+' entry produces this for file-1.
2826                 */
2827                temp->name = "/dev/null";
2828                strcpy(temp->hex, ".");
2829                strcpy(temp->mode, ".");
2830                return temp;
2831        }
2832
2833        if (!remove_tempfile_installed) {
2834                atexit(remove_tempfile);
2835                sigchain_push_common(remove_tempfile_on_signal);
2836                remove_tempfile_installed = 1;
2837        }
2838
2839        if (!one->sha1_valid ||
2840            reuse_worktree_file(name, one->sha1, 1)) {
2841                struct stat st;
2842                if (lstat(name, &st) < 0) {
2843                        if (errno == ENOENT)
2844                                goto not_a_valid_file;
2845                        die_errno("stat(%s)", name);
2846                }
2847                if (S_ISLNK(st.st_mode)) {
2848                        struct strbuf sb = STRBUF_INIT;
2849                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2850                                die_errno("readlink(%s)", name);
2851                        prep_temp_blob(name, temp, sb.buf, sb.len,
2852                                       (one->sha1_valid ?
2853                                        one->sha1 : null_sha1),
2854                                       (one->sha1_valid ?
2855                                        one->mode : S_IFLNK));
2856                        strbuf_release(&sb);
2857                }
2858                else {
2859                        /* we can borrow from the file in the work tree */
2860                        temp->name = name;
2861                        if (!one->sha1_valid)
2862                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2863                        else
2864                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2865                        /* Even though we may sometimes borrow the
2866                         * contents from the work tree, we always want
2867                         * one->mode.  mode is trustworthy even when
2868                         * !(one->sha1_valid), as long as
2869                         * DIFF_FILE_VALID(one).
2870                         */
2871                        sprintf(temp->mode, "%06o", one->mode);
2872                }
2873                return temp;
2874        }
2875        else {
2876                if (diff_populate_filespec(one, 0))
2877                        die("cannot read data blob for %s", one->path);
2878                prep_temp_blob(name, temp, one->data, one->size,
2879                               one->sha1, one->mode);
2880        }
2881        return temp;
2882}
2883
2884/* An external diff command takes:
2885 *
2886 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2887 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2888 *
2889 */
2890static void run_external_diff(const char *pgm,
2891                              const char *name,
2892                              const char *other,
2893                              struct diff_filespec *one,
2894                              struct diff_filespec *two,
2895                              const char *xfrm_msg,
2896                              int complete_rewrite)
2897{
2898        const char *spawn_arg[10];
2899        int retval;
2900        const char **arg = &spawn_arg[0];
2901
2902        if (one && two) {
2903                struct diff_tempfile *temp_one, *temp_two;
2904                const char *othername = (other ? other : name);
2905                temp_one = prepare_temp_file(name, one);
2906                temp_two = prepare_temp_file(othername, two);
2907                *arg++ = pgm;
2908                *arg++ = name;
2909                *arg++ = temp_one->name;
2910                *arg++ = temp_one->hex;
2911                *arg++ = temp_one->mode;
2912                *arg++ = temp_two->name;
2913                *arg++ = temp_two->hex;
2914                *arg++ = temp_two->mode;
2915                if (other) {
2916                        *arg++ = other;
2917                        *arg++ = xfrm_msg;
2918                }
2919        } else {
2920                *arg++ = pgm;
2921                *arg++ = name;
2922        }
2923        *arg = NULL;
2924        fflush(NULL);
2925        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2926        remove_tempfile();
2927        if (retval) {
2928                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2929                exit(1);
2930        }
2931}
2932
2933static int similarity_index(struct diff_filepair *p)
2934{
2935        return p->score * 100 / MAX_SCORE;
2936}
2937
2938static void fill_metainfo(struct strbuf *msg,
2939                          const char *name,
2940                          const char *other,
2941                          struct diff_filespec *one,
2942                          struct diff_filespec *two,
2943                          struct diff_options *o,
2944                          struct diff_filepair *p,
2945                          int *must_show_header,
2946                          int use_color)
2947{
2948        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2949        const char *reset = diff_get_color(use_color, DIFF_RESET);
2950        const char *line_prefix = diff_line_prefix(o);
2951
2952        *must_show_header = 1;
2953        strbuf_init(msg, PATH_MAX * 2 + 300);
2954        switch (p->status) {
2955        case DIFF_STATUS_COPIED:
2956                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2957                            line_prefix, set, similarity_index(p));
2958                strbuf_addf(msg, "%s\n%s%scopy from ",
2959                            reset,  line_prefix, set);
2960                quote_c_style(name, msg, NULL, 0);
2961                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2962                quote_c_style(other, msg, NULL, 0);
2963                strbuf_addf(msg, "%s\n", reset);
2964                break;
2965        case DIFF_STATUS_RENAMED:
2966                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2967                            line_prefix, set, similarity_index(p));
2968                strbuf_addf(msg, "%s\n%s%srename from ",
2969                            reset, line_prefix, set);
2970                quote_c_style(name, msg, NULL, 0);
2971                strbuf_addf(msg, "%s\n%s%srename to ",
2972                            reset, line_prefix, set);
2973                quote_c_style(other, msg, NULL, 0);
2974                strbuf_addf(msg, "%s\n", reset);
2975                break;
2976        case DIFF_STATUS_MODIFIED:
2977                if (p->score) {
2978                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2979                                    line_prefix,
2980                                    set, similarity_index(p), reset);
2981                        break;
2982                }
2983                /* fallthru */
2984        default:
2985                *must_show_header = 0;
2986        }
2987        if (one && two && hashcmp(one->sha1, two->sha1)) {
2988                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2989
2990                if (DIFF_OPT_TST(o, BINARY)) {
2991                        mmfile_t mf;
2992                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2993                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2994                                abbrev = 40;
2995                }
2996                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2997                            find_unique_abbrev(one->sha1, abbrev));
2998                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2999                if (one->mode == two->mode)
3000                        strbuf_addf(msg, " %06o", one->mode);
3001                strbuf_addf(msg, "%s\n", reset);
3002        }
3003}
3004
3005static void run_diff_cmd(const char *pgm,
3006                         const char *name,
3007                         const char *other,
3008                         const char *attr_path,
3009                         struct diff_filespec *one,
3010                         struct diff_filespec *two,
3011                         struct strbuf *msg,
3012                         struct diff_options *o,
3013                         struct diff_filepair *p)
3014{
3015        const char *xfrm_msg = NULL;
3016        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3017        int must_show_header = 0;
3018
3019
3020        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3021                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3022                if (drv && drv->external)
3023                        pgm = drv->external;
3024        }
3025
3026        if (msg) {
3027                /*
3028                 * don't use colors when the header is intended for an
3029                 * external diff driver
3030                 */
3031                fill_metainfo(msg, name, other, one, two, o, p,
3032                              &must_show_header,
3033                              want_color(o->use_color) && !pgm);
3034                xfrm_msg = msg->len ? msg->buf : NULL;
3035        }
3036
3037        if (pgm) {
3038                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3039                                  complete_rewrite);
3040                return;
3041        }
3042        if (one && two)
3043                builtin_diff(name, other ? other : name,
3044                             one, two, xfrm_msg, must_show_header,
3045                             o, complete_rewrite);
3046        else
3047                fprintf(o->file, "* Unmerged path %s\n", name);
3048}
3049
3050static void diff_fill_sha1_info(struct diff_filespec *one)
3051{
3052        if (DIFF_FILE_VALID(one)) {
3053                if (!one->sha1_valid) {
3054                        struct stat st;
3055                        if (one->is_stdin) {
3056                                hashcpy(one->sha1, null_sha1);
3057                                return;
3058                        }
3059                        if (lstat(one->path, &st) < 0)
3060                                die_errno("stat '%s'", one->path);
3061                        if (index_path(one->sha1, one->path, &st, 0))
3062                                die("cannot hash %s", one->path);
3063                }
3064        }
3065        else
3066                hashclr(one->sha1);
3067}
3068
3069static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3070{
3071        /* Strip the prefix but do not molest /dev/null and absolute paths */
3072        if (*namep && **namep != '/') {
3073                *namep += prefix_length;
3074                if (**namep == '/')
3075                        ++*namep;
3076        }
3077        if (*otherp && **otherp != '/') {
3078                *otherp += prefix_length;
3079                if (**otherp == '/')
3080                        ++*otherp;
3081        }
3082}
3083
3084static void run_diff(struct diff_filepair *p, struct diff_options *o)
3085{
3086        const char *pgm = external_diff();
3087        struct strbuf msg;
3088        struct diff_filespec *one = p->one;
3089        struct diff_filespec *two = p->two;
3090        const char *name;
3091        const char *other;
3092        const char *attr_path;
3093
3094        name  = p->one->path;
3095        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3096        attr_path = name;
3097        if (o->prefix_length)
3098                strip_prefix(o->prefix_length, &name, &other);
3099
3100        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3101                pgm = NULL;
3102
3103        if (DIFF_PAIR_UNMERGED(p)) {
3104                run_diff_cmd(pgm, name, NULL, attr_path,
3105                             NULL, NULL, NULL, o, p);
3106                return;
3107        }
3108
3109        diff_fill_sha1_info(one);
3110        diff_fill_sha1_info(two);
3111
3112        if (!pgm &&
3113            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3114            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3115                /*
3116                 * a filepair that changes between file and symlink
3117                 * needs to be split into deletion and creation.
3118                 */
3119                struct diff_filespec *null = alloc_filespec(two->path);
3120                run_diff_cmd(NULL, name, other, attr_path,
3121                             one, null, &msg, o, p);
3122                free(null);
3123                strbuf_release(&msg);
3124
3125                null = alloc_filespec(one->path);
3126                run_diff_cmd(NULL, name, other, attr_path,
3127                             null, two, &msg, o, p);
3128                free(null);
3129        }
3130        else
3131                run_diff_cmd(pgm, name, other, attr_path,
3132                             one, two, &msg, o, p);
3133
3134        strbuf_release(&msg);
3135}
3136
3137static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3138                         struct diffstat_t *diffstat)
3139{
3140        const char *name;
3141        const char *other;
3142
3143        if (DIFF_PAIR_UNMERGED(p)) {
3144                /* unmerged */
3145                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
3146                return;
3147        }
3148
3149        name = p->one->path;
3150        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3151
3152        if (o->prefix_length)
3153                strip_prefix(o->prefix_length, &name, &other);
3154
3155        diff_fill_sha1_info(p->one);
3156        diff_fill_sha1_info(p->two);
3157
3158        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
3159}
3160
3161static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3162{
3163        const char *name;
3164        const char *other;
3165        const char *attr_path;
3166
3167        if (DIFF_PAIR_UNMERGED(p)) {
3168                /* unmerged */
3169                return;
3170        }
3171
3172        name = p->one->path;
3173        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3174        attr_path = other ? other : name;
3175
3176        if (o->prefix_length)
3177                strip_prefix(o->prefix_length, &name, &other);
3178
3179        diff_fill_sha1_info(p->one);
3180        diff_fill_sha1_info(p->two);
3181
3182        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3183}
3184
3185void diff_setup(struct diff_options *options)
3186{
3187        memcpy(options, &default_diff_options, sizeof(*options));
3188
3189        options->file = stdout;
3190
3191        options->line_termination = '\n';
3192        options->break_opt = -1;
3193        options->rename_limit = -1;
3194        options->dirstat_permille = diff_dirstat_permille_default;
3195        options->context = diff_context_default;
3196        DIFF_OPT_SET(options, RENAME_EMPTY);
3197
3198        options->change = diff_change;
3199        options->add_remove = diff_addremove;
3200        options->use_color = diff_use_color_default;
3201        options->detect_rename = diff_detect_rename_default;
3202        options->xdl_opts |= diff_algorithm;
3203
3204        if (diff_no_prefix) {
3205                options->a_prefix = options->b_prefix = "";
3206        } else if (!diff_mnemonic_prefix) {
3207                options->a_prefix = "a/";
3208                options->b_prefix = "b/";
3209        }
3210}
3211
3212void diff_setup_done(struct diff_options *options)
3213{
3214        int count = 0;
3215
3216        if (options->output_format & DIFF_FORMAT_NAME)
3217                count++;
3218        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3219                count++;
3220        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3221                count++;
3222        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3223                count++;
3224        if (count > 1)
3225                die("--name-only, --name-status, --check and -s are mutually exclusive");
3226
3227        /*
3228         * Most of the time we can say "there are changes"
3229         * only by checking if there are changed paths, but
3230         * --ignore-whitespace* options force us to look
3231         * inside contents.
3232         */
3233
3234        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3235            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3236            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3237                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3238        else
3239                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3240
3241        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3242                options->detect_rename = DIFF_DETECT_COPY;
3243
3244        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3245                options->prefix = NULL;
3246        if (options->prefix)
3247                options->prefix_length = strlen(options->prefix);
3248        else
3249                options->prefix_length = 0;
3250
3251        if (options->output_format & (DIFF_FORMAT_NAME |
3252                                      DIFF_FORMAT_NAME_STATUS |
3253                                      DIFF_FORMAT_CHECKDIFF |
3254                                      DIFF_FORMAT_NO_OUTPUT))
3255                options->output_format &= ~(DIFF_FORMAT_RAW |
3256                                            DIFF_FORMAT_NUMSTAT |
3257                                            DIFF_FORMAT_DIFFSTAT |
3258                                            DIFF_FORMAT_SHORTSTAT |
3259                                            DIFF_FORMAT_DIRSTAT |
3260                                            DIFF_FORMAT_SUMMARY |
3261                                            DIFF_FORMAT_PATCH);
3262
3263        /*
3264         * These cases always need recursive; we do not drop caller-supplied
3265         * recursive bits for other formats here.
3266         */
3267        if (options->output_format & (DIFF_FORMAT_PATCH |
3268                                      DIFF_FORMAT_NUMSTAT |
3269                                      DIFF_FORMAT_DIFFSTAT |
3270                                      DIFF_FORMAT_SHORTSTAT |
3271                                      DIFF_FORMAT_DIRSTAT |
3272                                      DIFF_FORMAT_SUMMARY |
3273                                      DIFF_FORMAT_CHECKDIFF))
3274                DIFF_OPT_SET(options, RECURSIVE);
3275        /*
3276         * Also pickaxe would not work very well if you do not say recursive
3277         */
3278        if (options->pickaxe)
3279                DIFF_OPT_SET(options, RECURSIVE);
3280        /*
3281         * When patches are generated, submodules diffed against the work tree
3282         * must be checked for dirtiness too so it can be shown in the output
3283         */
3284        if (options->output_format & DIFF_FORMAT_PATCH)
3285                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3286
3287        if (options->detect_rename && options->rename_limit < 0)
3288                options->rename_limit = diff_rename_limit_default;
3289        if (options->setup & DIFF_SETUP_USE_CACHE) {
3290                if (!active_cache)
3291                        /* read-cache does not die even when it fails
3292                         * so it is safe for us to do this here.  Also
3293                         * it does not smudge active_cache or active_nr
3294                         * when it fails, so we do not have to worry about
3295                         * cleaning it up ourselves either.
3296                         */
3297                        read_cache();
3298        }
3299        if (options->abbrev <= 0 || 40 < options->abbrev)
3300                options->abbrev = 40; /* full */
3301
3302        /*
3303         * It does not make sense to show the first hit we happened
3304         * to have found.  It does not make sense not to return with
3305         * exit code in such a case either.
3306         */
3307        if (DIFF_OPT_TST(options, QUICK)) {
3308                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3309                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3310        }
3311}
3312
3313static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3314{
3315        char c, *eq;
3316        int len;
3317
3318        if (*arg != '-')
3319                return 0;
3320        c = *++arg;
3321        if (!c)
3322                return 0;
3323        if (c == arg_short) {
3324                c = *++arg;
3325                if (!c)
3326                        return 1;
3327                if (val && isdigit(c)) {
3328                        char *end;
3329                        int n = strtoul(arg, &end, 10);
3330                        if (*end)
3331                                return 0;
3332                        *val = n;
3333                        return 1;
3334                }
3335                return 0;
3336        }
3337        if (c != '-')
3338                return 0;
3339        arg++;
3340        eq = strchr(arg, '=');
3341        if (eq)
3342                len = eq - arg;
3343        else
3344                len = strlen(arg);
3345        if (!len || strncmp(arg, arg_long, len))
3346                return 0;
3347        if (eq) {
3348                int n;
3349                char *end;
3350                if (!isdigit(*++eq))
3351                        return 0;
3352                n = strtoul(eq, &end, 10);
3353                if (*end)
3354                        return 0;
3355                *val = n;
3356        }
3357        return 1;
3358}
3359
3360static int diff_scoreopt_parse(const char *opt);
3361
3362static inline int short_opt(char opt, const char **argv,
3363                            const char **optarg)
3364{
3365        const char *arg = argv[0];
3366        if (arg[0] != '-' || arg[1] != opt)
3367                return 0;
3368        if (arg[2] != '\0') {
3369                *optarg = arg + 2;
3370                return 1;
3371        }
3372        if (!argv[1])
3373                die("Option '%c' requires a value", opt);
3374        *optarg = argv[1];
3375        return 2;
3376}
3377
3378int parse_long_opt(const char *opt, const char **argv,
3379                   const char **optarg)
3380{
3381        const char *arg = argv[0];
3382        if (arg[0] != '-' || arg[1] != '-')
3383                return 0;
3384        arg += strlen("--");
3385        if (prefixcmp(arg, opt))
3386                return 0;
3387        arg += strlen(opt);
3388        if (*arg == '=') { /* sticked form: --option=value */
3389                *optarg = arg + 1;
3390                return 1;
3391        }
3392        if (*arg != '\0')
3393                return 0;
3394        /* separate form: --option value */
3395        if (!argv[1])
3396                die("Option '--%s' requires a value", opt);
3397        *optarg = argv[1];
3398        return 2;
3399}
3400
3401static int stat_opt(struct diff_options *options, const char **av)
3402{
3403        const char *arg = av[0];
3404        char *end;
3405        int width = options->stat_width;
3406        int name_width = options->stat_name_width;
3407        int graph_width = options->stat_graph_width;
3408        int count = options->stat_count;
3409        int argcount = 1;
3410
3411        arg += strlen("--stat");
3412        end = (char *)arg;
3413
3414        switch (*arg) {
3415        case '-':
3416                if (!prefixcmp(arg, "-width")) {
3417                        arg += strlen("-width");
3418                        if (*arg == '=')
3419                                width = strtoul(arg + 1, &end, 10);
3420                        else if (!*arg && !av[1])
3421                                die("Option '--stat-width' requires a value");
3422                        else if (!*arg) {
3423                                width = strtoul(av[1], &end, 10);
3424                                argcount = 2;
3425                        }
3426                } else if (!prefixcmp(arg, "-name-width")) {
3427                        arg += strlen("-name-width");
3428                        if (*arg == '=')
3429                                name_width = strtoul(arg + 1, &end, 10);
3430                        else if (!*arg && !av[1])
3431                                die("Option '--stat-name-width' requires a value");
3432                        else if (!*arg) {
3433                                name_width = strtoul(av[1], &end, 10);
3434                                argcount = 2;
3435                        }
3436                } else if (!prefixcmp(arg, "-graph-width")) {
3437                        arg += strlen("-graph-width");
3438                        if (*arg == '=')
3439                                graph_width = strtoul(arg + 1, &end, 10);
3440                        else if (!*arg && !av[1])
3441                                die("Option '--stat-graph-width' requires a value");
3442                        else if (!*arg) {
3443                                graph_width = strtoul(av[1], &end, 10);
3444                                argcount = 2;
3445                        }
3446                } else if (!prefixcmp(arg, "-count")) {
3447                        arg += strlen("-count");
3448                        if (*arg == '=')
3449                                count = strtoul(arg + 1, &end, 10);
3450                        else if (!*arg && !av[1])
3451                                die("Option '--stat-count' requires a value");
3452                        else if (!*arg) {
3453                                count = strtoul(av[1], &end, 10);
3454                                argcount = 2;
3455                        }
3456                }
3457                break;
3458        case '=':
3459                width = strtoul(arg+1, &end, 10);
3460                if (*end == ',')
3461                        name_width = strtoul(end+1, &end, 10);
3462                if (*end == ',')
3463                        count = strtoul(end+1, &end, 10);
3464        }
3465
3466        /* Important! This checks all the error cases! */
3467        if (*end)
3468                return 0;
3469        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3470        options->stat_name_width = name_width;
3471        options->stat_graph_width = graph_width;
3472        options->stat_width = width;
3473        options->stat_count = count;
3474        return argcount;
3475}
3476
3477static int parse_dirstat_opt(struct diff_options *options, const char *params)
3478{
3479        struct strbuf errmsg = STRBUF_INIT;
3480        if (parse_dirstat_params(options, params, &errmsg))
3481                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3482                    errmsg.buf);
3483        strbuf_release(&errmsg);
3484        /*
3485         * The caller knows a dirstat-related option is given from the command
3486         * line; allow it to say "return this_function();"
3487         */
3488        options->output_format |= DIFF_FORMAT_DIRSTAT;
3489        return 1;
3490}
3491
3492static int parse_submodule_opt(struct diff_options *options, const char *value)
3493{
3494        if (parse_submodule_params(options, value))
3495                die(_("Failed to parse --submodule option parameter: '%s'"),
3496                        value);
3497        return 1;
3498}
3499
3500int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3501{
3502        const char *arg = av[0];
3503        const char *optarg;
3504        int argcount;
3505
3506        /* Output format options */
3507        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3508                options->output_format |= DIFF_FORMAT_PATCH;
3509        else if (opt_arg(arg, 'U', "unified", &options->context))
3510                options->output_format |= DIFF_FORMAT_PATCH;
3511        else if (!strcmp(arg, "--raw"))
3512                options->output_format |= DIFF_FORMAT_RAW;
3513        else if (!strcmp(arg, "--patch-with-raw"))
3514                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3515        else if (!strcmp(arg, "--numstat"))
3516                options->output_format |= DIFF_FORMAT_NUMSTAT;
3517        else if (!strcmp(arg, "--shortstat"))
3518                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3519        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3520                return parse_dirstat_opt(options, "");
3521        else if (!prefixcmp(arg, "-X"))
3522                return parse_dirstat_opt(options, arg + 2);
3523        else if (!prefixcmp(arg, "--dirstat="))
3524                return parse_dirstat_opt(options, arg + 10);
3525        else if (!strcmp(arg, "--cumulative"))
3526                return parse_dirstat_opt(options, "cumulative");
3527        else if (!strcmp(arg, "--dirstat-by-file"))
3528                return parse_dirstat_opt(options, "files");
3529        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3530                parse_dirstat_opt(options, "files");
3531                return parse_dirstat_opt(options, arg + 18);
3532        }
3533        else if (!strcmp(arg, "--check"))
3534                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3535        else if (!strcmp(arg, "--summary"))
3536                options->output_format |= DIFF_FORMAT_SUMMARY;
3537        else if (!strcmp(arg, "--patch-with-stat"))
3538                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3539        else if (!strcmp(arg, "--name-only"))
3540                options->output_format |= DIFF_FORMAT_NAME;
3541        else if (!strcmp(arg, "--name-status"))
3542                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3543        else if (!strcmp(arg, "-s"))
3544                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3545        else if (!prefixcmp(arg, "--stat"))
3546                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3547                return stat_opt(options, av);
3548
3549        /* renames options */
3550        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3551                 !strcmp(arg, "--break-rewrites")) {
3552                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3553                        return error("invalid argument to -B: %s", arg+2);
3554        }
3555        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3556                 !strcmp(arg, "--find-renames")) {
3557                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3558                        return error("invalid argument to -M: %s", arg+2);
3559                options->detect_rename = DIFF_DETECT_RENAME;
3560        }
3561        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3562                options->irreversible_delete = 1;
3563        }
3564        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3565                 !strcmp(arg, "--find-copies")) {
3566                if (options->detect_rename == DIFF_DETECT_COPY)
3567                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3568                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3569                        return error("invalid argument to -C: %s", arg+2);
3570                options->detect_rename = DIFF_DETECT_COPY;
3571        }
3572        else if (!strcmp(arg, "--no-renames"))
3573                options->detect_rename = 0;
3574        else if (!strcmp(arg, "--rename-empty"))
3575                DIFF_OPT_SET(options, RENAME_EMPTY);
3576        else if (!strcmp(arg, "--no-rename-empty"))
3577                DIFF_OPT_CLR(options, RENAME_EMPTY);
3578        else if (!strcmp(arg, "--relative"))
3579                DIFF_OPT_SET(options, RELATIVE_NAME);
3580        else if (!prefixcmp(arg, "--relative=")) {
3581                DIFF_OPT_SET(options, RELATIVE_NAME);
3582                options->prefix = arg + 11;
3583        }
3584
3585        /* xdiff options */
3586        else if (!strcmp(arg, "--minimal"))
3587                DIFF_XDL_SET(options, NEED_MINIMAL);
3588        else if (!strcmp(arg, "--no-minimal"))
3589                DIFF_XDL_CLR(options, NEED_MINIMAL);
3590        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3591                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3592        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3593                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3594        else if (!strcmp(arg, "--ignore-space-at-eol"))
3595                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3596        else if (!strcmp(arg, "--patience"))
3597                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3598        else if (!strcmp(arg, "--histogram"))
3599                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3600        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
3601                long value = parse_algorithm_value(optarg);
3602                if (value < 0)
3603                        return error("option diff-algorithm accepts \"myers\", "
3604                                     "\"minimal\", \"patience\" and \"histogram\"");
3605                /* clear out previous settings */
3606                DIFF_XDL_CLR(options, NEED_MINIMAL);
3607                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
3608                options->xdl_opts |= value;
3609                return argcount;
3610        }
3611
3612        /* flags options */
3613        else if (!strcmp(arg, "--binary")) {
3614                options->output_format |= DIFF_FORMAT_PATCH;
3615                DIFF_OPT_SET(options, BINARY);
3616        }
3617        else if (!strcmp(arg, "--full-index"))
3618                DIFF_OPT_SET(options, FULL_INDEX);
3619        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3620                DIFF_OPT_SET(options, TEXT);
3621        else if (!strcmp(arg, "-R"))
3622                DIFF_OPT_SET(options, REVERSE_DIFF);
3623        else if (!strcmp(arg, "--find-copies-harder"))
3624                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3625        else if (!strcmp(arg, "--follow"))
3626                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3627        else if (!strcmp(arg, "--no-follow"))
3628                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
3629        else if (!strcmp(arg, "--color"))
3630                options->use_color = 1;
3631        else if (!prefixcmp(arg, "--color=")) {
3632                int value = git_config_colorbool(NULL, arg+8);
3633                if (value < 0)
3634                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3635                options->use_color = value;
3636        }
3637        else if (!strcmp(arg, "--no-color"))
3638                options->use_color = 0;
3639        else if (!strcmp(arg, "--color-words")) {
3640                options->use_color = 1;
3641                options->word_diff = DIFF_WORDS_COLOR;
3642        }
3643        else if (!prefixcmp(arg, "--color-words=")) {
3644                options->use_color = 1;
3645                options->word_diff = DIFF_WORDS_COLOR;
3646                options->word_regex = arg + 14;
3647        }
3648        else if (!strcmp(arg, "--word-diff")) {
3649                if (options->word_diff == DIFF_WORDS_NONE)
3650                        options->word_diff = DIFF_WORDS_PLAIN;
3651        }
3652        else if (!prefixcmp(arg, "--word-diff=")) {
3653                const char *type = arg + 12;
3654                if (!strcmp(type, "plain"))
3655                        options->word_diff = DIFF_WORDS_PLAIN;
3656                else if (!strcmp(type, "color")) {
3657                        options->use_color = 1;
3658                        options->word_diff = DIFF_WORDS_COLOR;
3659                }
3660                else if (!strcmp(type, "porcelain"))
3661                        options->word_diff = DIFF_WORDS_PORCELAIN;
3662                else if (!strcmp(type, "none"))
3663                        options->word_diff = DIFF_WORDS_NONE;
3664                else
3665                        die("bad --word-diff argument: %s", type);
3666        }
3667        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3668                if (options->word_diff == DIFF_WORDS_NONE)
3669                        options->word_diff = DIFF_WORDS_PLAIN;
3670                options->word_regex = optarg;
3671                return argcount;
3672        }
3673        else if (!strcmp(arg, "--exit-code"))
3674                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3675        else if (!strcmp(arg, "--quiet"))
3676                DIFF_OPT_SET(options, QUICK);
3677        else if (!strcmp(arg, "--ext-diff"))
3678                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3679        else if (!strcmp(arg, "--no-ext-diff"))
3680                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3681        else if (!strcmp(arg, "--textconv"))
3682                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3683        else if (!strcmp(arg, "--no-textconv"))
3684                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3685        else if (!strcmp(arg, "--ignore-submodules")) {
3686                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3687                handle_ignore_submodules_arg(options, "all");
3688        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3689                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3690                handle_ignore_submodules_arg(options, arg + 20);
3691        } else if (!strcmp(arg, "--submodule"))
3692                DIFF_OPT_SET(options, SUBMODULE_LOG);
3693        else if (!prefixcmp(arg, "--submodule="))
3694                return parse_submodule_opt(options, arg + 12);
3695
3696        /* misc options */
3697        else if (!strcmp(arg, "-z"))
3698                options->line_termination = 0;
3699        else if ((argcount = short_opt('l', av, &optarg))) {
3700                options->rename_limit = strtoul(optarg, NULL, 10);
3701                return argcount;
3702        }
3703        else if ((argcount = short_opt('S', av, &optarg))) {
3704                options->pickaxe = optarg;
3705                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3706                return argcount;
3707        } else if ((argcount = short_opt('G', av, &optarg))) {
3708                options->pickaxe = optarg;
3709                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3710                return argcount;
3711        }
3712        else if (!strcmp(arg, "--pickaxe-all"))
3713                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3714        else if (!strcmp(arg, "--pickaxe-regex"))
3715                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3716        else if ((argcount = short_opt('O', av, &optarg))) {
3717                options->orderfile = optarg;
3718                return argcount;
3719        }
3720        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3721                options->filter = optarg;
3722                return argcount;
3723        }
3724        else if (!strcmp(arg, "--abbrev"))
3725                options->abbrev = DEFAULT_ABBREV;
3726        else if (!prefixcmp(arg, "--abbrev=")) {
3727                options->abbrev = strtoul(arg + 9, NULL, 10);
3728                if (options->abbrev < MINIMUM_ABBREV)
3729                        options->abbrev = MINIMUM_ABBREV;
3730                else if (40 < options->abbrev)
3731                        options->abbrev = 40;
3732        }
3733        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3734                options->a_prefix = optarg;
3735                return argcount;
3736        }
3737        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3738                options->b_prefix = optarg;
3739                return argcount;
3740        }
3741        else if (!strcmp(arg, "--no-prefix"))
3742                options->a_prefix = options->b_prefix = "";
3743        else if (opt_arg(arg, '\0', "inter-hunk-context",
3744                         &options->interhunkcontext))
3745                ;
3746        else if (!strcmp(arg, "-W"))
3747                DIFF_OPT_SET(options, FUNCCONTEXT);
3748        else if (!strcmp(arg, "--function-context"))
3749                DIFF_OPT_SET(options, FUNCCONTEXT);
3750        else if (!strcmp(arg, "--no-function-context"))
3751                DIFF_OPT_CLR(options, FUNCCONTEXT);
3752        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3753                options->file = fopen(optarg, "w");
3754                if (!options->file)
3755                        die_errno("Could not open '%s'", optarg);
3756                options->close_file = 1;
3757                return argcount;
3758        } else
3759                return 0;
3760        return 1;
3761}
3762
3763int parse_rename_score(const char **cp_p)
3764{
3765        unsigned long num, scale;
3766        int ch, dot;
3767        const char *cp = *cp_p;
3768
3769        num = 0;
3770        scale = 1;
3771        dot = 0;
3772        for (;;) {
3773                ch = *cp;
3774                if ( !dot && ch == '.' ) {
3775                        scale = 1;
3776                        dot = 1;
3777                } else if ( ch == '%' ) {
3778                        scale = dot ? scale*100 : 100;
3779                        cp++;   /* % is always at the end */
3780                        break;
3781                } else if ( ch >= '0' && ch <= '9' ) {
3782                        if ( scale < 100000 ) {
3783                                scale *= 10;
3784                                num = (num*10) + (ch-'0');
3785                        }
3786                } else {
3787                        break;
3788                }
3789                cp++;
3790        }
3791        *cp_p = cp;
3792
3793        /* user says num divided by scale and we say internally that
3794         * is MAX_SCORE * num / scale.
3795         */
3796        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3797}
3798
3799static int diff_scoreopt_parse(const char *opt)
3800{
3801        int opt1, opt2, cmd;
3802
3803        if (*opt++ != '-')
3804                return -1;
3805        cmd = *opt++;
3806        if (cmd == '-') {
3807                /* convert the long-form arguments into short-form versions */
3808                if (!prefixcmp(opt, "break-rewrites")) {
3809                        opt += strlen("break-rewrites");
3810                        if (*opt == 0 || *opt++ == '=')
3811                                cmd = 'B';
3812                } else if (!prefixcmp(opt, "find-copies")) {
3813                        opt += strlen("find-copies");
3814                        if (*opt == 0 || *opt++ == '=')
3815                                cmd = 'C';
3816                } else if (!prefixcmp(opt, "find-renames")) {
3817                        opt += strlen("find-renames");
3818                        if (*opt == 0 || *opt++ == '=')
3819                                cmd = 'M';
3820                }
3821        }
3822        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3823                return -1; /* that is not a -M, -C nor -B option */
3824
3825        opt1 = parse_rename_score(&opt);
3826        if (cmd != 'B')
3827                opt2 = 0;
3828        else {
3829                if (*opt == 0)
3830                        opt2 = 0;
3831                else if (*opt != '/')
3832                        return -1; /* we expect -B80/99 or -B80 */
3833                else {
3834                        opt++;
3835                        opt2 = parse_rename_score(&opt);
3836                }
3837        }
3838        if (*opt != 0)
3839                return -1;
3840        return opt1 | (opt2 << 16);
3841}
3842
3843struct diff_queue_struct diff_queued_diff;
3844
3845void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3846{
3847        if (queue->alloc <= queue->nr) {
3848                queue->alloc = alloc_nr(queue->alloc);
3849                queue->queue = xrealloc(queue->queue,
3850                                        sizeof(dp) * queue->alloc);
3851        }
3852        queue->queue[queue->nr++] = dp;
3853}
3854
3855struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3856                                 struct diff_filespec *one,
3857                                 struct diff_filespec *two)
3858{
3859        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3860        dp->one = one;
3861        dp->two = two;
3862        if (queue)
3863                diff_q(queue, dp);
3864        return dp;
3865}
3866
3867void diff_free_filepair(struct diff_filepair *p)
3868{
3869        free_filespec(p->one);
3870        free_filespec(p->two);
3871        free(p);
3872}
3873
3874/* This is different from find_unique_abbrev() in that
3875 * it stuffs the result with dots for alignment.
3876 */
3877const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3878{
3879        int abblen;
3880        const char *abbrev;
3881        if (len == 40)
3882                return sha1_to_hex(sha1);
3883
3884        abbrev = find_unique_abbrev(sha1, len);
3885        abblen = strlen(abbrev);
3886        if (abblen < 37) {
3887                static char hex[41];
3888                if (len < abblen && abblen <= len + 2)
3889                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3890                else
3891                        sprintf(hex, "%s...", abbrev);
3892                return hex;
3893        }
3894        return sha1_to_hex(sha1);
3895}
3896
3897static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3898{
3899        int line_termination = opt->line_termination;
3900        int inter_name_termination = line_termination ? '\t' : '\0';
3901
3902        fprintf(opt->file, "%s", diff_line_prefix(opt));
3903        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3904                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3905                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3906                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3907        }
3908        if (p->score) {
3909                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3910                        inter_name_termination);
3911        } else {
3912                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3913        }
3914
3915        if (p->status == DIFF_STATUS_COPIED ||
3916            p->status == DIFF_STATUS_RENAMED) {
3917                const char *name_a, *name_b;
3918                name_a = p->one->path;
3919                name_b = p->two->path;
3920                strip_prefix(opt->prefix_length, &name_a, &name_b);
3921                write_name_quoted(name_a, opt->file, inter_name_termination);
3922                write_name_quoted(name_b, opt->file, line_termination);
3923        } else {
3924                const char *name_a, *name_b;
3925                name_a = p->one->mode ? p->one->path : p->two->path;
3926                name_b = NULL;
3927                strip_prefix(opt->prefix_length, &name_a, &name_b);
3928                write_name_quoted(name_a, opt->file, line_termination);
3929        }
3930}
3931
3932int diff_unmodified_pair(struct diff_filepair *p)
3933{
3934        /* This function is written stricter than necessary to support
3935         * the currently implemented transformers, but the idea is to
3936         * let transformers to produce diff_filepairs any way they want,
3937         * and filter and clean them up here before producing the output.
3938         */
3939        struct diff_filespec *one = p->one, *two = p->two;
3940
3941        if (DIFF_PAIR_UNMERGED(p))
3942                return 0; /* unmerged is interesting */
3943
3944        /* deletion, addition, mode or type change
3945         * and rename are all interesting.
3946         */
3947        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3948            DIFF_PAIR_MODE_CHANGED(p) ||
3949            strcmp(one->path, two->path))
3950                return 0;
3951
3952        /* both are valid and point at the same path.  that is, we are
3953         * dealing with a change.
3954         */
3955        if (one->sha1_valid && two->sha1_valid &&
3956            !hashcmp(one->sha1, two->sha1) &&
3957            !one->dirty_submodule && !two->dirty_submodule)
3958                return 1; /* no change */
3959        if (!one->sha1_valid && !two->sha1_valid)
3960                return 1; /* both look at the same file on the filesystem. */
3961        return 0;
3962}
3963
3964static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3965{
3966        if (diff_unmodified_pair(p))
3967                return;
3968
3969        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3970            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3971                return; /* no tree diffs in patch format */
3972
3973        run_diff(p, o);
3974}
3975
3976static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3977                            struct diffstat_t *diffstat)
3978{
3979        if (diff_unmodified_pair(p))
3980                return;
3981
3982        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3983            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3984                return; /* no useful stat for tree diffs */
3985
3986        run_diffstat(p, o, diffstat);
3987}
3988
3989static void diff_flush_checkdiff(struct diff_filepair *p,
3990                struct diff_options *o)
3991{
3992        if (diff_unmodified_pair(p))
3993                return;
3994
3995        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3996            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3997                return; /* nothing to check in tree diffs */
3998
3999        run_checkdiff(p, o);
4000}
4001
4002int diff_queue_is_empty(void)
4003{
4004        struct diff_queue_struct *q = &diff_queued_diff;
4005        int i;
4006        for (i = 0; i < q->nr; i++)
4007                if (!diff_unmodified_pair(q->queue[i]))
4008                        return 0;
4009        return 1;
4010}
4011
4012#if DIFF_DEBUG
4013void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
4014{
4015        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
4016                x, one ? one : "",
4017                s->path,
4018                DIFF_FILE_VALID(s) ? "valid" : "invalid",
4019                s->mode,
4020                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
4021        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
4022                x, one ? one : "",
4023                s->size, s->xfrm_flags);
4024}
4025
4026void diff_debug_filepair(const struct diff_filepair *p, int i)
4027{
4028        diff_debug_filespec(p->one, i, "one");
4029        diff_debug_filespec(p->two, i, "two");
4030        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4031                p->score, p->status ? p->status : '?',
4032                p->one->rename_used, p->broken_pair);
4033}
4034
4035void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4036{
4037        int i;
4038        if (msg)
4039                fprintf(stderr, "%s\n", msg);
4040        fprintf(stderr, "q->nr = %d\n", q->nr);
4041        for (i = 0; i < q->nr; i++) {
4042                struct diff_filepair *p = q->queue[i];
4043                diff_debug_filepair(p, i);
4044        }
4045}
4046#endif
4047
4048static void diff_resolve_rename_copy(void)
4049{
4050        int i;
4051        struct diff_filepair *p;
4052        struct diff_queue_struct *q = &diff_queued_diff;
4053
4054        diff_debug_queue("resolve-rename-copy", q);
4055
4056        for (i = 0; i < q->nr; i++) {
4057                p = q->queue[i];
4058                p->status = 0; /* undecided */
4059                if (DIFF_PAIR_UNMERGED(p))
4060                        p->status = DIFF_STATUS_UNMERGED;
4061                else if (!DIFF_FILE_VALID(p->one))
4062                        p->status = DIFF_STATUS_ADDED;
4063                else if (!DIFF_FILE_VALID(p->two))
4064                        p->status = DIFF_STATUS_DELETED;
4065                else if (DIFF_PAIR_TYPE_CHANGED(p))
4066                        p->status = DIFF_STATUS_TYPE_CHANGED;
4067
4068                /* from this point on, we are dealing with a pair
4069                 * whose both sides are valid and of the same type, i.e.
4070                 * either in-place edit or rename/copy edit.
4071                 */
4072                else if (DIFF_PAIR_RENAME(p)) {
4073                        /*
4074                         * A rename might have re-connected a broken
4075                         * pair up, causing the pathnames to be the
4076                         * same again. If so, that's not a rename at
4077                         * all, just a modification..
4078                         *
4079                         * Otherwise, see if this source was used for
4080                         * multiple renames, in which case we decrement
4081                         * the count, and call it a copy.
4082                         */
4083                        if (!strcmp(p->one->path, p->two->path))
4084                                p->status = DIFF_STATUS_MODIFIED;
4085                        else if (--p->one->rename_used > 0)
4086                                p->status = DIFF_STATUS_COPIED;
4087                        else
4088                                p->status = DIFF_STATUS_RENAMED;
4089                }
4090                else if (hashcmp(p->one->sha1, p->two->sha1) ||
4091                         p->one->mode != p->two->mode ||
4092                         p->one->dirty_submodule ||
4093                         p->two->dirty_submodule ||
4094                         is_null_sha1(p->one->sha1))
4095                        p->status = DIFF_STATUS_MODIFIED;
4096                else {
4097                        /* This is a "no-change" entry and should not
4098                         * happen anymore, but prepare for broken callers.
4099                         */
4100                        error("feeding unmodified %s to diffcore",
4101                              p->one->path);
4102                        p->status = DIFF_STATUS_UNKNOWN;
4103                }
4104        }
4105        diff_debug_queue("resolve-rename-copy done", q);
4106}
4107
4108static int check_pair_status(struct diff_filepair *p)
4109{
4110        switch (p->status) {
4111        case DIFF_STATUS_UNKNOWN:
4112                return 0;
4113        case 0:
4114                die("internal error in diff-resolve-rename-copy");
4115        default:
4116                return 1;
4117        }
4118}
4119
4120static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4121{
4122        int fmt = opt->output_format;
4123
4124        if (fmt & DIFF_FORMAT_CHECKDIFF)
4125                diff_flush_checkdiff(p, opt);
4126        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4127                diff_flush_raw(p, opt);
4128        else if (fmt & DIFF_FORMAT_NAME) {
4129                const char *name_a, *name_b;
4130                name_a = p->two->path;
4131                name_b = NULL;
4132                strip_prefix(opt->prefix_length, &name_a, &name_b);
4133                write_name_quoted(name_a, opt->file, opt->line_termination);
4134        }
4135}
4136
4137static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4138{
4139        if (fs->mode)
4140                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4141        else
4142                fprintf(file, " %s ", newdelete);
4143        write_name_quoted(fs->path, file, '\n');
4144}
4145
4146
4147static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4148                const char *line_prefix)
4149{
4150        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4151                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4152                        p->two->mode, show_name ? ' ' : '\n');
4153                if (show_name) {
4154                        write_name_quoted(p->two->path, file, '\n');
4155                }
4156        }
4157}
4158
4159static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4160                        const char *line_prefix)
4161{
4162        char *names = pprint_rename(p->one->path, p->two->path);
4163
4164        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4165        free(names);
4166        show_mode_change(file, p, 0, line_prefix);
4167}
4168
4169static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4170{
4171        FILE *file = opt->file;
4172        const char *line_prefix = diff_line_prefix(opt);
4173
4174        switch(p->status) {
4175        case DIFF_STATUS_DELETED:
4176                fputs(line_prefix, file);
4177                show_file_mode_name(file, "delete", p->one);
4178                break;
4179        case DIFF_STATUS_ADDED:
4180                fputs(line_prefix, file);
4181                show_file_mode_name(file, "create", p->two);
4182                break;
4183        case DIFF_STATUS_COPIED:
4184                fputs(line_prefix, file);
4185                show_rename_copy(file, "copy", p, line_prefix);
4186                break;
4187        case DIFF_STATUS_RENAMED:
4188                fputs(line_prefix, file);
4189                show_rename_copy(file, "rename", p, line_prefix);
4190                break;
4191        default:
4192                if (p->score) {
4193                        fprintf(file, "%s rewrite ", line_prefix);
4194                        write_name_quoted(p->two->path, file, ' ');
4195                        fprintf(file, "(%d%%)\n", similarity_index(p));
4196                }
4197                show_mode_change(file, p, !p->score, line_prefix);
4198                break;
4199        }
4200}
4201
4202struct patch_id_t {
4203        git_SHA_CTX *ctx;
4204        int patchlen;
4205};
4206
4207static int remove_space(char *line, int len)
4208{
4209        int i;
4210        char *dst = line;
4211        unsigned char c;
4212
4213        for (i = 0; i < len; i++)
4214                if (!isspace((c = line[i])))
4215                        *dst++ = c;
4216
4217        return dst - line;
4218}
4219
4220static void patch_id_consume(void *priv, char *line, unsigned long len)
4221{
4222        struct patch_id_t *data = priv;
4223        int new_len;
4224
4225        /* Ignore line numbers when computing the SHA1 of the patch */
4226        if (!prefixcmp(line, "@@ -"))
4227                return;
4228
4229        new_len = remove_space(line, len);
4230
4231        git_SHA1_Update(data->ctx, line, new_len);
4232        data->patchlen += new_len;
4233}
4234
4235/* returns 0 upon success, and writes result into sha1 */
4236static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4237{
4238        struct diff_queue_struct *q = &diff_queued_diff;
4239        int i;
4240        git_SHA_CTX ctx;
4241        struct patch_id_t data;
4242        char buffer[PATH_MAX * 4 + 20];
4243
4244        git_SHA1_Init(&ctx);
4245        memset(&data, 0, sizeof(struct patch_id_t));
4246        data.ctx = &ctx;
4247
4248        for (i = 0; i < q->nr; i++) {
4249                xpparam_t xpp;
4250                xdemitconf_t xecfg;
4251                mmfile_t mf1, mf2;
4252                struct diff_filepair *p = q->queue[i];
4253                int len1, len2;
4254
4255                memset(&xpp, 0, sizeof(xpp));
4256                memset(&xecfg, 0, sizeof(xecfg));
4257                if (p->status == 0)
4258                        return error("internal diff status error");
4259                if (p->status == DIFF_STATUS_UNKNOWN)
4260                        continue;
4261                if (diff_unmodified_pair(p))
4262                        continue;
4263                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4264                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4265                        continue;
4266                if (DIFF_PAIR_UNMERGED(p))
4267                        continue;
4268
4269                diff_fill_sha1_info(p->one);
4270                diff_fill_sha1_info(p->two);
4271                if (fill_mmfile(&mf1, p->one) < 0 ||
4272                                fill_mmfile(&mf2, p->two) < 0)
4273                        return error("unable to read files to diff");
4274
4275                len1 = remove_space(p->one->path, strlen(p->one->path));
4276                len2 = remove_space(p->two->path, strlen(p->two->path));
4277                if (p->one->mode == 0)
4278                        len1 = snprintf(buffer, sizeof(buffer),
4279                                        "diff--gita/%.*sb/%.*s"
4280                                        "newfilemode%06o"
4281                                        "---/dev/null"
4282                                        "+++b/%.*s",
4283                                        len1, p->one->path,
4284                                        len2, p->two->path,
4285                                        p->two->mode,
4286                                        len2, p->two->path);
4287                else if (p->two->mode == 0)
4288                        len1 = snprintf(buffer, sizeof(buffer),
4289                                        "diff--gita/%.*sb/%.*s"
4290                                        "deletedfilemode%06o"
4291                                        "---a/%.*s"
4292                                        "+++/dev/null",
4293                                        len1, p->one->path,
4294                                        len2, p->two->path,
4295                                        p->one->mode,
4296                                        len1, p->one->path);
4297                else
4298                        len1 = snprintf(buffer, sizeof(buffer),
4299                                        "diff--gita/%.*sb/%.*s"
4300                                        "---a/%.*s"
4301                                        "+++b/%.*s",
4302                                        len1, p->one->path,
4303                                        len2, p->two->path,
4304                                        len1, p->one->path,
4305                                        len2, p->two->path);
4306                git_SHA1_Update(&ctx, buffer, len1);
4307
4308                if (diff_filespec_is_binary(p->one) ||
4309                    diff_filespec_is_binary(p->two)) {
4310                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4311                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4312                        continue;
4313                }
4314
4315                xpp.flags = 0;
4316                xecfg.ctxlen = 3;
4317                xecfg.flags = 0;
4318                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4319                              &xpp, &xecfg);
4320        }
4321
4322        git_SHA1_Final(sha1, &ctx);
4323        return 0;
4324}
4325
4326int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4327{
4328        struct diff_queue_struct *q = &diff_queued_diff;
4329        int i;
4330        int result = diff_get_patch_id(options, sha1);
4331
4332        for (i = 0; i < q->nr; i++)
4333                diff_free_filepair(q->queue[i]);
4334
4335        free(q->queue);
4336        DIFF_QUEUE_CLEAR(q);
4337
4338        return result;
4339}
4340
4341static int is_summary_empty(const struct diff_queue_struct *q)
4342{
4343        int i;
4344
4345        for (i = 0; i < q->nr; i++) {
4346                const struct diff_filepair *p = q->queue[i];
4347
4348                switch (p->status) {
4349                case DIFF_STATUS_DELETED:
4350                case DIFF_STATUS_ADDED:
4351                case DIFF_STATUS_COPIED:
4352                case DIFF_STATUS_RENAMED:
4353                        return 0;
4354                default:
4355                        if (p->score)
4356                                return 0;
4357                        if (p->one->mode && p->two->mode &&
4358                            p->one->mode != p->two->mode)
4359                                return 0;
4360                        break;
4361                }
4362        }
4363        return 1;
4364}
4365
4366static const char rename_limit_warning[] =
4367"inexact rename detection was skipped due to too many files.";
4368
4369static const char degrade_cc_to_c_warning[] =
4370"only found copies from modified paths due to too many files.";
4371
4372static const char rename_limit_advice[] =
4373"you may want to set your %s variable to at least "
4374"%d and retry the command.";
4375
4376void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4377{
4378        if (degraded_cc)
4379                warning(degrade_cc_to_c_warning);
4380        else if (needed)
4381                warning(rename_limit_warning);
4382        else
4383                return;
4384        if (0 < needed && needed < 32767)
4385                warning(rename_limit_advice, varname, needed);
4386}
4387
4388void diff_flush(struct diff_options *options)
4389{
4390        struct diff_queue_struct *q = &diff_queued_diff;
4391        int i, output_format = options->output_format;
4392        int separator = 0;
4393        int dirstat_by_line = 0;
4394
4395        /*
4396         * Order: raw, stat, summary, patch
4397         * or:    name/name-status/checkdiff (other bits clear)
4398         */
4399        if (!q->nr)
4400                goto free_queue;
4401
4402        if (output_format & (DIFF_FORMAT_RAW |
4403                             DIFF_FORMAT_NAME |
4404                             DIFF_FORMAT_NAME_STATUS |
4405                             DIFF_FORMAT_CHECKDIFF)) {
4406                for (i = 0; i < q->nr; i++) {
4407                        struct diff_filepair *p = q->queue[i];
4408                        if (check_pair_status(p))
4409                                flush_one_pair(p, options);
4410                }
4411                separator++;
4412        }
4413
4414        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4415                dirstat_by_line = 1;
4416
4417        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4418            dirstat_by_line) {
4419                struct diffstat_t diffstat;
4420
4421                memset(&diffstat, 0, sizeof(struct diffstat_t));
4422                for (i = 0; i < q->nr; i++) {
4423                        struct diff_filepair *p = q->queue[i];
4424                        if (check_pair_status(p))
4425                                diff_flush_stat(p, options, &diffstat);
4426                }
4427                if (output_format & DIFF_FORMAT_NUMSTAT)
4428                        show_numstat(&diffstat, options);
4429                if (output_format & DIFF_FORMAT_DIFFSTAT)
4430                        show_stats(&diffstat, options);
4431                if (output_format & DIFF_FORMAT_SHORTSTAT)
4432                        show_shortstats(&diffstat, options);
4433                if (output_format & DIFF_FORMAT_DIRSTAT)
4434                        show_dirstat_by_line(&diffstat, options);
4435                free_diffstat_info(&diffstat);
4436                separator++;
4437        }
4438        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4439                show_dirstat(options);
4440
4441        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4442                for (i = 0; i < q->nr; i++) {
4443                        diff_summary(options, q->queue[i]);
4444                }
4445                separator++;
4446        }
4447
4448        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4449            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4450            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4451                /*
4452                 * run diff_flush_patch for the exit status. setting
4453                 * options->file to /dev/null should be safe, becaue we
4454                 * aren't supposed to produce any output anyway.
4455                 */
4456                if (options->close_file)
4457                        fclose(options->file);
4458                options->file = fopen("/dev/null", "w");
4459                if (!options->file)
4460                        die_errno("Could not open /dev/null");
4461                options->close_file = 1;
4462                for (i = 0; i < q->nr; i++) {
4463                        struct diff_filepair *p = q->queue[i];
4464                        if (check_pair_status(p))
4465                                diff_flush_patch(p, options);
4466                        if (options->found_changes)
4467                                break;
4468                }
4469        }
4470
4471        if (output_format & DIFF_FORMAT_PATCH) {
4472                if (separator) {
4473                        fprintf(options->file, "%s%c",
4474                                diff_line_prefix(options),
4475                                options->line_termination);
4476                        if (options->stat_sep) {
4477                                /* attach patch instead of inline */
4478                                fputs(options->stat_sep, options->file);
4479                        }
4480                }
4481
4482                for (i = 0; i < q->nr; i++) {
4483                        struct diff_filepair *p = q->queue[i];
4484                        if (check_pair_status(p))
4485                                diff_flush_patch(p, options);
4486                }
4487        }
4488
4489        if (output_format & DIFF_FORMAT_CALLBACK)
4490                options->format_callback(q, options, options->format_callback_data);
4491
4492        for (i = 0; i < q->nr; i++)
4493                diff_free_filepair(q->queue[i]);
4494free_queue:
4495        free(q->queue);
4496        DIFF_QUEUE_CLEAR(q);
4497        if (options->close_file)
4498                fclose(options->file);
4499
4500        /*
4501         * Report the content-level differences with HAS_CHANGES;
4502         * diff_addremove/diff_change does not set the bit when
4503         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4504         */
4505        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4506                if (options->found_changes)
4507                        DIFF_OPT_SET(options, HAS_CHANGES);
4508                else
4509                        DIFF_OPT_CLR(options, HAS_CHANGES);
4510        }
4511}
4512
4513static void diffcore_apply_filter(const char *filter)
4514{
4515        int i;
4516        struct diff_queue_struct *q = &diff_queued_diff;
4517        struct diff_queue_struct outq;
4518        DIFF_QUEUE_CLEAR(&outq);
4519
4520        if (!filter)
4521                return;
4522
4523        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4524                int found;
4525                for (i = found = 0; !found && i < q->nr; i++) {
4526                        struct diff_filepair *p = q->queue[i];
4527                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4528                             ((p->score &&
4529                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4530                              (!p->score &&
4531                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4532                            ((p->status != DIFF_STATUS_MODIFIED) &&
4533                             strchr(filter, p->status)))
4534                                found++;
4535                }
4536                if (found)
4537                        return;
4538
4539                /* otherwise we will clear the whole queue
4540                 * by copying the empty outq at the end of this
4541                 * function, but first clear the current entries
4542                 * in the queue.
4543                 */
4544                for (i = 0; i < q->nr; i++)
4545                        diff_free_filepair(q->queue[i]);
4546        }
4547        else {
4548                /* Only the matching ones */
4549                for (i = 0; i < q->nr; i++) {
4550                        struct diff_filepair *p = q->queue[i];
4551
4552                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4553                             ((p->score &&
4554                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4555                              (!p->score &&
4556                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4557                            ((p->status != DIFF_STATUS_MODIFIED) &&
4558                             strchr(filter, p->status)))
4559                                diff_q(&outq, p);
4560                        else
4561                                diff_free_filepair(p);
4562                }
4563        }
4564        free(q->queue);
4565        *q = outq;
4566}
4567
4568/* Check whether two filespecs with the same mode and size are identical */
4569static int diff_filespec_is_identical(struct diff_filespec *one,
4570                                      struct diff_filespec *two)
4571{
4572        if (S_ISGITLINK(one->mode))
4573                return 0;
4574        if (diff_populate_filespec(one, 0))
4575                return 0;
4576        if (diff_populate_filespec(two, 0))
4577                return 0;
4578        return !memcmp(one->data, two->data, one->size);
4579}
4580
4581static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4582{
4583        int i;
4584        struct diff_queue_struct *q = &diff_queued_diff;
4585        struct diff_queue_struct outq;
4586        DIFF_QUEUE_CLEAR(&outq);
4587
4588        for (i = 0; i < q->nr; i++) {
4589                struct diff_filepair *p = q->queue[i];
4590
4591                /*
4592                 * 1. Entries that come from stat info dirtiness
4593                 *    always have both sides (iow, not create/delete),
4594                 *    one side of the object name is unknown, with
4595                 *    the same mode and size.  Keep the ones that
4596                 *    do not match these criteria.  They have real
4597                 *    differences.
4598                 *
4599                 * 2. At this point, the file is known to be modified,
4600                 *    with the same mode and size, and the object
4601                 *    name of one side is unknown.  Need to inspect
4602                 *    the identical contents.
4603                 */
4604                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4605                    !DIFF_FILE_VALID(p->two) ||
4606                    (p->one->sha1_valid && p->two->sha1_valid) ||
4607                    (p->one->mode != p->two->mode) ||
4608                    diff_populate_filespec(p->one, 1) ||
4609                    diff_populate_filespec(p->two, 1) ||
4610                    (p->one->size != p->two->size) ||
4611                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4612                        diff_q(&outq, p);
4613                else {
4614                        /*
4615                         * The caller can subtract 1 from skip_stat_unmatch
4616                         * to determine how many paths were dirty only
4617                         * due to stat info mismatch.
4618                         */
4619                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4620                                diffopt->skip_stat_unmatch++;
4621                        diff_free_filepair(p);
4622                }
4623        }
4624        free(q->queue);
4625        *q = outq;
4626}
4627
4628static int diffnamecmp(const void *a_, const void *b_)
4629{
4630        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4631        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4632        const char *name_a, *name_b;
4633
4634        name_a = a->one ? a->one->path : a->two->path;
4635        name_b = b->one ? b->one->path : b->two->path;
4636        return strcmp(name_a, name_b);
4637}
4638
4639void diffcore_fix_diff_index(struct diff_options *options)
4640{
4641        struct diff_queue_struct *q = &diff_queued_diff;
4642        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4643}
4644
4645void diffcore_std(struct diff_options *options)
4646{
4647        if (options->skip_stat_unmatch)
4648                diffcore_skip_stat_unmatch(options);
4649        if (!options->found_follow) {
4650                /* See try_to_follow_renames() in tree-diff.c */
4651                if (options->break_opt != -1)
4652                        diffcore_break(options->break_opt);
4653                if (options->detect_rename)
4654                        diffcore_rename(options);
4655                if (options->break_opt != -1)
4656                        diffcore_merge_broken();
4657        }
4658        if (options->pickaxe)
4659                diffcore_pickaxe(options);
4660        if (options->orderfile)
4661                diffcore_order(options->orderfile);
4662        if (!options->found_follow)
4663                /* See try_to_follow_renames() in tree-diff.c */
4664                diff_resolve_rename_copy();
4665        diffcore_apply_filter(options->filter);
4666
4667        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4668                DIFF_OPT_SET(options, HAS_CHANGES);
4669        else
4670                DIFF_OPT_CLR(options, HAS_CHANGES);
4671
4672        options->found_follow = 0;
4673}
4674
4675int diff_result_code(struct diff_options *opt, int status)
4676{
4677        int result = 0;
4678
4679        diff_warn_rename_limit("diff.renameLimit",
4680                               opt->needed_rename_limit,
4681                               opt->degraded_cc_to_c);
4682        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4683            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4684                return status;
4685        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4686            DIFF_OPT_TST(opt, HAS_CHANGES))
4687                result |= 01;
4688        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4689            DIFF_OPT_TST(opt, CHECK_FAILED))
4690                result |= 02;
4691        return result;
4692}
4693
4694int diff_can_quit_early(struct diff_options *opt)
4695{
4696        return (DIFF_OPT_TST(opt, QUICK) &&
4697                !opt->filter &&
4698                DIFF_OPT_TST(opt, HAS_CHANGES));
4699}
4700
4701/*
4702 * Shall changes to this submodule be ignored?
4703 *
4704 * Submodule changes can be configured to be ignored separately for each path,
4705 * but that configuration can be overridden from the command line.
4706 */
4707static int is_submodule_ignored(const char *path, struct diff_options *options)
4708{
4709        int ignored = 0;
4710        unsigned orig_flags = options->flags;
4711        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4712                set_diffopt_flags_from_submodule_config(options, path);
4713        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4714                ignored = 1;
4715        options->flags = orig_flags;
4716        return ignored;
4717}
4718
4719void diff_addremove(struct diff_options *options,
4720                    int addremove, unsigned mode,
4721                    const unsigned char *sha1,
4722                    int sha1_valid,
4723                    const char *concatpath, unsigned dirty_submodule)
4724{
4725        struct diff_filespec *one, *two;
4726
4727        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4728                return;
4729
4730        /* This may look odd, but it is a preparation for
4731         * feeding "there are unchanged files which should
4732         * not produce diffs, but when you are doing copy
4733         * detection you would need them, so here they are"
4734         * entries to the diff-core.  They will be prefixed
4735         * with something like '=' or '*' (I haven't decided
4736         * which but should not make any difference).
4737         * Feeding the same new and old to diff_change()
4738         * also has the same effect.
4739         * Before the final output happens, they are pruned after
4740         * merged into rename/copy pairs as appropriate.
4741         */
4742        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4743                addremove = (addremove == '+' ? '-' :
4744                             addremove == '-' ? '+' : addremove);
4745
4746        if (options->prefix &&
4747            strncmp(concatpath, options->prefix, options->prefix_length))
4748                return;
4749
4750        one = alloc_filespec(concatpath);
4751        two = alloc_filespec(concatpath);
4752
4753        if (addremove != '+')
4754                fill_filespec(one, sha1, sha1_valid, mode);
4755        if (addremove != '-') {
4756                fill_filespec(two, sha1, sha1_valid, mode);
4757                two->dirty_submodule = dirty_submodule;
4758        }
4759
4760        diff_queue(&diff_queued_diff, one, two);
4761        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4762                DIFF_OPT_SET(options, HAS_CHANGES);
4763}
4764
4765void diff_change(struct diff_options *options,
4766                 unsigned old_mode, unsigned new_mode,
4767                 const unsigned char *old_sha1,
4768                 const unsigned char *new_sha1,
4769                 int old_sha1_valid, int new_sha1_valid,
4770                 const char *concatpath,
4771                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4772{
4773        struct diff_filespec *one, *two;
4774
4775        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4776            is_submodule_ignored(concatpath, options))
4777                return;
4778
4779        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4780                unsigned tmp;
4781                const unsigned char *tmp_c;
4782                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4783                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4784                tmp = old_sha1_valid; old_sha1_valid = new_sha1_valid;
4785                        new_sha1_valid = tmp;
4786                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4787                        new_dirty_submodule = tmp;
4788        }
4789
4790        if (options->prefix &&
4791            strncmp(concatpath, options->prefix, options->prefix_length))
4792                return;
4793
4794        one = alloc_filespec(concatpath);
4795        two = alloc_filespec(concatpath);
4796        fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
4797        fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
4798        one->dirty_submodule = old_dirty_submodule;
4799        two->dirty_submodule = new_dirty_submodule;
4800
4801        diff_queue(&diff_queued_diff, one, two);
4802        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4803                DIFF_OPT_SET(options, HAS_CHANGES);
4804}
4805
4806struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4807{
4808        struct diff_filepair *pair;
4809        struct diff_filespec *one, *two;
4810
4811        if (options->prefix &&
4812            strncmp(path, options->prefix, options->prefix_length))
4813                return NULL;
4814
4815        one = alloc_filespec(path);
4816        two = alloc_filespec(path);
4817        pair = diff_queue(&diff_queued_diff, one, two);
4818        pair->is_unmerged = 1;
4819        return pair;
4820}
4821
4822static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4823                size_t *outsize)
4824{
4825        struct diff_tempfile *temp;
4826        const char *argv[3];
4827        const char **arg = argv;
4828        struct child_process child;
4829        struct strbuf buf = STRBUF_INIT;
4830        int err = 0;
4831
4832        temp = prepare_temp_file(spec->path, spec);
4833        *arg++ = pgm;
4834        *arg++ = temp->name;
4835        *arg = NULL;
4836
4837        memset(&child, 0, sizeof(child));
4838        child.use_shell = 1;
4839        child.argv = argv;
4840        child.out = -1;
4841        if (start_command(&child)) {
4842                remove_tempfile();
4843                return NULL;
4844        }
4845
4846        if (strbuf_read(&buf, child.out, 0) < 0)
4847                err = error("error reading from textconv command '%s'", pgm);
4848        close(child.out);
4849
4850        if (finish_command(&child) || err) {
4851                strbuf_release(&buf);
4852                remove_tempfile();
4853                return NULL;
4854        }
4855        remove_tempfile();
4856
4857        return strbuf_detach(&buf, outsize);
4858}
4859
4860size_t fill_textconv(struct userdiff_driver *driver,
4861                     struct diff_filespec *df,
4862                     char **outbuf)
4863{
4864        size_t size;
4865
4866        if (!driver || !driver->textconv) {
4867                if (!DIFF_FILE_VALID(df)) {
4868                        *outbuf = "";
4869                        return 0;
4870                }
4871                if (diff_populate_filespec(df, 0))
4872                        die("unable to read files to diff");
4873                *outbuf = df->data;
4874                return df->size;
4875        }
4876
4877        if (driver->textconv_cache && df->sha1_valid) {
4878                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4879                                          &size);
4880                if (*outbuf)
4881                        return size;
4882        }
4883
4884        *outbuf = run_textconv(driver->textconv, df, &size);
4885        if (!*outbuf)
4886                die("unable to read files to diff");
4887
4888        if (driver->textconv_cache && df->sha1_valid) {
4889                /* ignore errors, as we might be in a readonly repository */
4890                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4891                                size);
4892                /*
4893                 * we could save up changes and flush them all at the end,
4894                 * but we would need an extra call after all diffing is done.
4895                 * Since generating a cache entry is the slow path anyway,
4896                 * this extra overhead probably isn't a big deal.
4897                 */
4898                notes_cache_write(driver->textconv_cache);
4899        }
4900
4901        return size;
4902}
4903
4904void setup_diff_pager(struct diff_options *opt)
4905{
4906        /*
4907         * If the user asked for our exit code, then either they want --quiet
4908         * or --exit-code. We should definitely not bother with a pager in the
4909         * former case, as we will generate no output. Since we still properly
4910         * report our exit code even when a pager is run, we _could_ run a
4911         * pager with --exit-code. But since we have not done so historically,
4912         * and because it is easy to find people oneline advising "git diff
4913         * --exit-code" in hooks and other scripts, we do not do so.
4914         */
4915        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4916            check_pager_config("diff") != 0)
4917                setup_pager();
4918}