diff.con commit Merge branch 'jc/doc-long-options' (0115042)
   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
  19#ifdef NO_FAST_WORKING_DIRECTORY
  20#define FAST_WORKING_DIRECTORY 0
  21#else
  22#define FAST_WORKING_DIRECTORY 1
  23#endif
  24
  25static int diff_detect_rename_default;
  26static int diff_rename_limit_default = 400;
  27static int diff_suppress_blank_empty;
  28static int diff_use_color_default = -1;
  29static const char *diff_word_regex_cfg;
  30static const char *external_diff_cmd_cfg;
  31int diff_auto_refresh_index = 1;
  32static int diff_mnemonic_prefix;
  33static int diff_no_prefix;
  34static int diff_stat_graph_width;
  35static int diff_dirstat_permille_default = 30;
  36static struct diff_options default_diff_options;
  37
  38static char diff_colors[][COLOR_MAXLEN] = {
  39        GIT_COLOR_RESET,
  40        GIT_COLOR_NORMAL,       /* PLAIN */
  41        GIT_COLOR_BOLD,         /* METAINFO */
  42        GIT_COLOR_CYAN,         /* FRAGINFO */
  43        GIT_COLOR_RED,          /* OLD */
  44        GIT_COLOR_GREEN,        /* NEW */
  45        GIT_COLOR_YELLOW,       /* COMMIT */
  46        GIT_COLOR_BG_RED,       /* WHITESPACE */
  47        GIT_COLOR_NORMAL,       /* FUNCINFO */
  48};
  49
  50static int parse_diff_color_slot(const char *var, int ofs)
  51{
  52        if (!strcasecmp(var+ofs, "plain"))
  53                return DIFF_PLAIN;
  54        if (!strcasecmp(var+ofs, "meta"))
  55                return DIFF_METAINFO;
  56        if (!strcasecmp(var+ofs, "frag"))
  57                return DIFF_FRAGINFO;
  58        if (!strcasecmp(var+ofs, "old"))
  59                return DIFF_FILE_OLD;
  60        if (!strcasecmp(var+ofs, "new"))
  61                return DIFF_FILE_NEW;
  62        if (!strcasecmp(var+ofs, "commit"))
  63                return DIFF_COMMIT;
  64        if (!strcasecmp(var+ofs, "whitespace"))
  65                return DIFF_WHITESPACE;
  66        if (!strcasecmp(var+ofs, "func"))
  67                return DIFF_FUNCINFO;
  68        return -1;
  69}
  70
  71static int parse_dirstat_params(struct diff_options *options, const char *params,
  72                                struct strbuf *errmsg)
  73{
  74        const char *p = params;
  75        int p_len, ret = 0;
  76
  77        while (*p) {
  78                p_len = strchrnul(p, ',') - p;
  79                if (!memcmp(p, "changes", p_len)) {
  80                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  81                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  82                } else if (!memcmp(p, "lines", p_len)) {
  83                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
  84                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  85                } else if (!memcmp(p, "files", p_len)) {
  86                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  87                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
  88                } else if (!memcmp(p, "noncumulative", p_len)) {
  89                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
  90                } else if (!memcmp(p, "cumulative", p_len)) {
  91                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
  92                } else if (isdigit(*p)) {
  93                        char *end;
  94                        int permille = strtoul(p, &end, 10) * 10;
  95                        if (*end == '.' && isdigit(*++end)) {
  96                                /* only use first digit */
  97                                permille += *end - '0';
  98                                /* .. and ignore any further digits */
  99                                while (isdigit(*++end))
 100                                        ; /* nothing */
 101                        }
 102                        if (end - p == p_len)
 103                                options->dirstat_permille = permille;
 104                        else {
 105                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%.*s'\n"),
 106                                            p_len, p);
 107                                ret++;
 108                        }
 109                } else {
 110                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%.*s'\n"),
 111                                    p_len, p);
 112                        ret++;
 113                }
 114
 115                p += p_len;
 116
 117                if (*p)
 118                        p++; /* more parameters, swallow separator */
 119        }
 120        return ret;
 121}
 122
 123static int git_config_rename(const char *var, const char *value)
 124{
 125        if (!value)
 126                return DIFF_DETECT_RENAME;
 127        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 128                return  DIFF_DETECT_COPY;
 129        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 130}
 131
 132/*
 133 * These are to give UI layer defaults.
 134 * The core-level commands such as git-diff-files should
 135 * never be affected by the setting of diff.renames
 136 * the user happens to have in the configuration file.
 137 */
 138int git_diff_ui_config(const char *var, const char *value, void *cb)
 139{
 140        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 141                diff_use_color_default = git_config_colorbool(var, value);
 142                return 0;
 143        }
 144        if (!strcmp(var, "diff.renames")) {
 145                diff_detect_rename_default = git_config_rename(var, value);
 146                return 0;
 147        }
 148        if (!strcmp(var, "diff.autorefreshindex")) {
 149                diff_auto_refresh_index = git_config_bool(var, value);
 150                return 0;
 151        }
 152        if (!strcmp(var, "diff.mnemonicprefix")) {
 153                diff_mnemonic_prefix = git_config_bool(var, value);
 154                return 0;
 155        }
 156        if (!strcmp(var, "diff.noprefix")) {
 157                diff_no_prefix = git_config_bool(var, value);
 158                return 0;
 159        }
 160        if (!strcmp(var, "diff.statgraphwidth")) {
 161                diff_stat_graph_width = git_config_int(var, value);
 162                return 0;
 163        }
 164        if (!strcmp(var, "diff.external"))
 165                return git_config_string(&external_diff_cmd_cfg, var, value);
 166        if (!strcmp(var, "diff.wordregex"))
 167                return git_config_string(&diff_word_regex_cfg, var, value);
 168
 169        if (!strcmp(var, "diff.ignoresubmodules"))
 170                handle_ignore_submodules_arg(&default_diff_options, value);
 171
 172        if (git_color_config(var, value, cb) < 0)
 173                return -1;
 174
 175        return git_diff_basic_config(var, value, cb);
 176}
 177
 178int git_diff_basic_config(const char *var, const char *value, void *cb)
 179{
 180        if (!strcmp(var, "diff.renamelimit")) {
 181                diff_rename_limit_default = git_config_int(var, value);
 182                return 0;
 183        }
 184
 185        if (userdiff_config(var, value) < 0)
 186                return -1;
 187
 188        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 189                int slot = parse_diff_color_slot(var, 11);
 190                if (slot < 0)
 191                        return 0;
 192                if (!value)
 193                        return config_error_nonbool(var);
 194                color_parse(value, var, diff_colors[slot]);
 195                return 0;
 196        }
 197
 198        /* like GNU diff's --suppress-blank-empty option  */
 199        if (!strcmp(var, "diff.suppressblankempty") ||
 200                        /* for backwards compatibility */
 201                        !strcmp(var, "diff.suppress-blank-empty")) {
 202                diff_suppress_blank_empty = git_config_bool(var, value);
 203                return 0;
 204        }
 205
 206        if (!strcmp(var, "diff.dirstat")) {
 207                struct strbuf errmsg = STRBUF_INIT;
 208                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 209                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 210                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 211                                errmsg.buf);
 212                strbuf_release(&errmsg);
 213                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 214                return 0;
 215        }
 216
 217        if (!prefixcmp(var, "submodule."))
 218                return parse_submodule_config_option(var, value);
 219
 220        return git_default_config(var, value, cb);
 221}
 222
 223static char *quote_two(const char *one, const char *two)
 224{
 225        int need_one = quote_c_style(one, NULL, NULL, 1);
 226        int need_two = quote_c_style(two, NULL, NULL, 1);
 227        struct strbuf res = STRBUF_INIT;
 228
 229        if (need_one + need_two) {
 230                strbuf_addch(&res, '"');
 231                quote_c_style(one, &res, NULL, 1);
 232                quote_c_style(two, &res, NULL, 1);
 233                strbuf_addch(&res, '"');
 234        } else {
 235                strbuf_addstr(&res, one);
 236                strbuf_addstr(&res, two);
 237        }
 238        return strbuf_detach(&res, NULL);
 239}
 240
 241static const char *external_diff(void)
 242{
 243        static const char *external_diff_cmd = NULL;
 244        static int done_preparing = 0;
 245
 246        if (done_preparing)
 247                return external_diff_cmd;
 248        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 249        if (!external_diff_cmd)
 250                external_diff_cmd = external_diff_cmd_cfg;
 251        done_preparing = 1;
 252        return external_diff_cmd;
 253}
 254
 255static struct diff_tempfile {
 256        const char *name; /* filename external diff should read from */
 257        char hex[41];
 258        char mode[10];
 259        char tmp_path[PATH_MAX];
 260} diff_temp[2];
 261
 262typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 263
 264struct emit_callback {
 265        int color_diff;
 266        unsigned ws_rule;
 267        int blank_at_eof_in_preimage;
 268        int blank_at_eof_in_postimage;
 269        int lno_in_preimage;
 270        int lno_in_postimage;
 271        sane_truncate_fn truncate;
 272        const char **label_path;
 273        struct diff_words_data *diff_words;
 274        struct diff_options *opt;
 275        int *found_changesp;
 276        struct strbuf *header;
 277};
 278
 279static int count_lines(const char *data, int size)
 280{
 281        int count, ch, completely_empty = 1, nl_just_seen = 0;
 282        count = 0;
 283        while (0 < size--) {
 284                ch = *data++;
 285                if (ch == '\n') {
 286                        count++;
 287                        nl_just_seen = 1;
 288                        completely_empty = 0;
 289                }
 290                else {
 291                        nl_just_seen = 0;
 292                        completely_empty = 0;
 293                }
 294        }
 295        if (completely_empty)
 296                return 0;
 297        if (!nl_just_seen)
 298                count++; /* no trailing newline */
 299        return count;
 300}
 301
 302static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 303{
 304        if (!DIFF_FILE_VALID(one)) {
 305                mf->ptr = (char *)""; /* does not matter */
 306                mf->size = 0;
 307                return 0;
 308        }
 309        else if (diff_populate_filespec(one, 0))
 310                return -1;
 311
 312        mf->ptr = one->data;
 313        mf->size = one->size;
 314        return 0;
 315}
 316
 317/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 318static unsigned long diff_filespec_size(struct diff_filespec *one)
 319{
 320        if (!DIFF_FILE_VALID(one))
 321                return 0;
 322        diff_populate_filespec(one, 1);
 323        return one->size;
 324}
 325
 326static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 327{
 328        char *ptr = mf->ptr;
 329        long size = mf->size;
 330        int cnt = 0;
 331
 332        if (!size)
 333                return cnt;
 334        ptr += size - 1; /* pointing at the very end */
 335        if (*ptr != '\n')
 336                ; /* incomplete line */
 337        else
 338                ptr--; /* skip the last LF */
 339        while (mf->ptr < ptr) {
 340                char *prev_eol;
 341                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 342                        if (*prev_eol == '\n')
 343                                break;
 344                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 345                        break;
 346                cnt++;
 347                ptr = prev_eol - 1;
 348        }
 349        return cnt;
 350}
 351
 352static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 353                               struct emit_callback *ecbdata)
 354{
 355        int l1, l2, at;
 356        unsigned ws_rule = ecbdata->ws_rule;
 357        l1 = count_trailing_blank(mf1, ws_rule);
 358        l2 = count_trailing_blank(mf2, ws_rule);
 359        if (l2 <= l1) {
 360                ecbdata->blank_at_eof_in_preimage = 0;
 361                ecbdata->blank_at_eof_in_postimage = 0;
 362                return;
 363        }
 364        at = count_lines(mf1->ptr, mf1->size);
 365        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 366
 367        at = count_lines(mf2->ptr, mf2->size);
 368        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 369}
 370
 371static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 372                        int first, const char *line, int len)
 373{
 374        int has_trailing_newline, has_trailing_carriage_return;
 375        int nofirst;
 376        FILE *file = o->file;
 377
 378        if (o->output_prefix) {
 379                struct strbuf *msg = NULL;
 380                msg = o->output_prefix(o, o->output_prefix_data);
 381                assert(msg);
 382                fwrite(msg->buf, msg->len, 1, file);
 383        }
 384
 385        if (len == 0) {
 386                has_trailing_newline = (first == '\n');
 387                has_trailing_carriage_return = (!has_trailing_newline &&
 388                                                (first == '\r'));
 389                nofirst = has_trailing_newline || has_trailing_carriage_return;
 390        } else {
 391                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 392                if (has_trailing_newline)
 393                        len--;
 394                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 395                if (has_trailing_carriage_return)
 396                        len--;
 397                nofirst = 0;
 398        }
 399
 400        if (len || !nofirst) {
 401                fputs(set, file);
 402                if (!nofirst)
 403                        fputc(first, file);
 404                fwrite(line, len, 1, file);
 405                fputs(reset, file);
 406        }
 407        if (has_trailing_carriage_return)
 408                fputc('\r', file);
 409        if (has_trailing_newline)
 410                fputc('\n', file);
 411}
 412
 413static void emit_line(struct diff_options *o, const char *set, const char *reset,
 414                      const char *line, int len)
 415{
 416        emit_line_0(o, set, reset, line[0], line+1, len-1);
 417}
 418
 419static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 420{
 421        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 422              ecbdata->blank_at_eof_in_preimage &&
 423              ecbdata->blank_at_eof_in_postimage &&
 424              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 425              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 426                return 0;
 427        return ws_blank_line(line, len, ecbdata->ws_rule);
 428}
 429
 430static void emit_add_line(const char *reset,
 431                          struct emit_callback *ecbdata,
 432                          const char *line, int len)
 433{
 434        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 435        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 436
 437        if (!*ws)
 438                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 439        else if (new_blank_line_at_eof(ecbdata, line, len))
 440                /* Blank line at EOF - paint '+' as well */
 441                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 442        else {
 443                /* Emit just the prefix, then the rest. */
 444                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 445                ws_check_emit(line, len, ecbdata->ws_rule,
 446                              ecbdata->opt->file, set, reset, ws);
 447        }
 448}
 449
 450static void emit_hunk_header(struct emit_callback *ecbdata,
 451                             const char *line, int len)
 452{
 453        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 454        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 455        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 456        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 457        static const char atat[2] = { '@', '@' };
 458        const char *cp, *ep;
 459        struct strbuf msgbuf = STRBUF_INIT;
 460        int org_len = len;
 461        int i = 1;
 462
 463        /*
 464         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 465         * it always is at least 10 bytes long.
 466         */
 467        if (len < 10 ||
 468            memcmp(line, atat, 2) ||
 469            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 470                emit_line(ecbdata->opt, plain, reset, line, len);
 471                return;
 472        }
 473        ep += 2; /* skip over @@ */
 474
 475        /* The hunk header in fraginfo color */
 476        strbuf_add(&msgbuf, frag, strlen(frag));
 477        strbuf_add(&msgbuf, line, ep - line);
 478        strbuf_add(&msgbuf, reset, strlen(reset));
 479
 480        /*
 481         * trailing "\r\n"
 482         */
 483        for ( ; i < 3; i++)
 484                if (line[len - i] == '\r' || line[len - i] == '\n')
 485                        len--;
 486
 487        /* blank before the func header */
 488        for (cp = ep; ep - line < len; ep++)
 489                if (*ep != ' ' && *ep != '\t')
 490                        break;
 491        if (ep != cp) {
 492                strbuf_add(&msgbuf, plain, strlen(plain));
 493                strbuf_add(&msgbuf, cp, ep - cp);
 494                strbuf_add(&msgbuf, reset, strlen(reset));
 495        }
 496
 497        if (ep < line + len) {
 498                strbuf_add(&msgbuf, func, strlen(func));
 499                strbuf_add(&msgbuf, ep, line + len - ep);
 500                strbuf_add(&msgbuf, reset, strlen(reset));
 501        }
 502
 503        strbuf_add(&msgbuf, line + len, org_len - len);
 504        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 505        strbuf_release(&msgbuf);
 506}
 507
 508static struct diff_tempfile *claim_diff_tempfile(void) {
 509        int i;
 510        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 511                if (!diff_temp[i].name)
 512                        return diff_temp + i;
 513        die("BUG: diff is failing to clean up its tempfiles");
 514}
 515
 516static int remove_tempfile_installed;
 517
 518static void remove_tempfile(void)
 519{
 520        int i;
 521        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 522                if (diff_temp[i].name == diff_temp[i].tmp_path)
 523                        unlink_or_warn(diff_temp[i].name);
 524                diff_temp[i].name = NULL;
 525        }
 526}
 527
 528static void remove_tempfile_on_signal(int signo)
 529{
 530        remove_tempfile();
 531        sigchain_pop(signo);
 532        raise(signo);
 533}
 534
 535static void print_line_count(FILE *file, int count)
 536{
 537        switch (count) {
 538        case 0:
 539                fprintf(file, "0,0");
 540                break;
 541        case 1:
 542                fprintf(file, "1");
 543                break;
 544        default:
 545                fprintf(file, "1,%d", count);
 546                break;
 547        }
 548}
 549
 550static void emit_rewrite_lines(struct emit_callback *ecb,
 551                               int prefix, const char *data, int size)
 552{
 553        const char *endp = NULL;
 554        static const char *nneof = " No newline at end of file\n";
 555        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 556        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 557
 558        while (0 < size) {
 559                int len;
 560
 561                endp = memchr(data, '\n', size);
 562                len = endp ? (endp - data + 1) : size;
 563                if (prefix != '+') {
 564                        ecb->lno_in_preimage++;
 565                        emit_line_0(ecb->opt, old, reset, '-',
 566                                    data, len);
 567                } else {
 568                        ecb->lno_in_postimage++;
 569                        emit_add_line(reset, ecb, data, len);
 570                }
 571                size -= len;
 572                data += len;
 573        }
 574        if (!endp) {
 575                const char *plain = diff_get_color(ecb->color_diff,
 576                                                   DIFF_PLAIN);
 577                putc('\n', ecb->opt->file);
 578                emit_line_0(ecb->opt, plain, reset, '\\',
 579                            nneof, strlen(nneof));
 580        }
 581}
 582
 583static void emit_rewrite_diff(const char *name_a,
 584                              const char *name_b,
 585                              struct diff_filespec *one,
 586                              struct diff_filespec *two,
 587                              struct userdiff_driver *textconv_one,
 588                              struct userdiff_driver *textconv_two,
 589                              struct diff_options *o)
 590{
 591        int lc_a, lc_b;
 592        const char *name_a_tab, *name_b_tab;
 593        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 594        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 595        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 596        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 597        const char *a_prefix, *b_prefix;
 598        char *data_one, *data_two;
 599        size_t size_one, size_two;
 600        struct emit_callback ecbdata;
 601        char *line_prefix = "";
 602        struct strbuf *msgbuf;
 603
 604        if (o && o->output_prefix) {
 605                msgbuf = o->output_prefix(o, o->output_prefix_data);
 606                line_prefix = msgbuf->buf;
 607        }
 608
 609        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 610                a_prefix = o->b_prefix;
 611                b_prefix = o->a_prefix;
 612        } else {
 613                a_prefix = o->a_prefix;
 614                b_prefix = o->b_prefix;
 615        }
 616
 617        name_a += (*name_a == '/');
 618        name_b += (*name_b == '/');
 619        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 620        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 621
 622        strbuf_reset(&a_name);
 623        strbuf_reset(&b_name);
 624        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 625        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 626
 627        size_one = fill_textconv(textconv_one, one, &data_one);
 628        size_two = fill_textconv(textconv_two, two, &data_two);
 629
 630        memset(&ecbdata, 0, sizeof(ecbdata));
 631        ecbdata.color_diff = want_color(o->use_color);
 632        ecbdata.found_changesp = &o->found_changes;
 633        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 634        ecbdata.opt = o;
 635        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 636                mmfile_t mf1, mf2;
 637                mf1.ptr = (char *)data_one;
 638                mf2.ptr = (char *)data_two;
 639                mf1.size = size_one;
 640                mf2.size = size_two;
 641                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 642        }
 643        ecbdata.lno_in_preimage = 1;
 644        ecbdata.lno_in_postimage = 1;
 645
 646        lc_a = count_lines(data_one, size_one);
 647        lc_b = count_lines(data_two, size_two);
 648        fprintf(o->file,
 649                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 650                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 651                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 652                line_prefix, fraginfo);
 653        if (!o->irreversible_delete)
 654                print_line_count(o->file, lc_a);
 655        else
 656                fprintf(o->file, "?,?");
 657        fprintf(o->file, " +");
 658        print_line_count(o->file, lc_b);
 659        fprintf(o->file, " @@%s\n", reset);
 660        if (lc_a && !o->irreversible_delete)
 661                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 662        if (lc_b)
 663                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 664        if (textconv_one)
 665                free((char *)data_one);
 666        if (textconv_two)
 667                free((char *)data_two);
 668}
 669
 670struct diff_words_buffer {
 671        mmfile_t text;
 672        long alloc;
 673        struct diff_words_orig {
 674                const char *begin, *end;
 675        } *orig;
 676        int orig_nr, orig_alloc;
 677};
 678
 679static void diff_words_append(char *line, unsigned long len,
 680                struct diff_words_buffer *buffer)
 681{
 682        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 683        line++;
 684        len--;
 685        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 686        buffer->text.size += len;
 687        buffer->text.ptr[buffer->text.size] = '\0';
 688}
 689
 690struct diff_words_style_elem {
 691        const char *prefix;
 692        const char *suffix;
 693        const char *color; /* NULL; filled in by the setup code if
 694                            * color is enabled */
 695};
 696
 697struct diff_words_style {
 698        enum diff_words_type type;
 699        struct diff_words_style_elem new, old, ctx;
 700        const char *newline;
 701};
 702
 703static struct diff_words_style diff_words_styles[] = {
 704        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 705        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 706        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 707};
 708
 709struct diff_words_data {
 710        struct diff_words_buffer minus, plus;
 711        const char *current_plus;
 712        int last_minus;
 713        struct diff_options *opt;
 714        regex_t *word_regex;
 715        enum diff_words_type type;
 716        struct diff_words_style *style;
 717};
 718
 719static int fn_out_diff_words_write_helper(FILE *fp,
 720                                          struct diff_words_style_elem *st_el,
 721                                          const char *newline,
 722                                          size_t count, const char *buf,
 723                                          const char *line_prefix)
 724{
 725        int print = 0;
 726
 727        while (count) {
 728                char *p = memchr(buf, '\n', count);
 729                if (print)
 730                        fputs(line_prefix, fp);
 731                if (p != buf) {
 732                        if (st_el->color && fputs(st_el->color, fp) < 0)
 733                                return -1;
 734                        if (fputs(st_el->prefix, fp) < 0 ||
 735                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 736                            fputs(st_el->suffix, fp) < 0)
 737                                return -1;
 738                        if (st_el->color && *st_el->color
 739                            && fputs(GIT_COLOR_RESET, fp) < 0)
 740                                return -1;
 741                }
 742                if (!p)
 743                        return 0;
 744                if (fputs(newline, fp) < 0)
 745                        return -1;
 746                count -= p + 1 - buf;
 747                buf = p + 1;
 748                print = 1;
 749        }
 750        return 0;
 751}
 752
 753/*
 754 * '--color-words' algorithm can be described as:
 755 *
 756 *   1. collect a the minus/plus lines of a diff hunk, divided into
 757 *      minus-lines and plus-lines;
 758 *
 759 *   2. break both minus-lines and plus-lines into words and
 760 *      place them into two mmfile_t with one word for each line;
 761 *
 762 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 763 *
 764 * And for the common parts of the both file, we output the plus side text.
 765 * diff_words->current_plus is used to trace the current position of the plus file
 766 * which printed. diff_words->last_minus is used to trace the last minus word
 767 * printed.
 768 *
 769 * For '--graph' to work with '--color-words', we need to output the graph prefix
 770 * on each line of color words output. Generally, there are two conditions on
 771 * which we should output the prefix.
 772 *
 773 *   1. diff_words->last_minus == 0 &&
 774 *      diff_words->current_plus == diff_words->plus.text.ptr
 775 *
 776 *      that is: the plus text must start as a new line, and if there is no minus
 777 *      word printed, a graph prefix must be printed.
 778 *
 779 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 780 *      *(diff_words->current_plus - 1) == '\n'
 781 *
 782 *      that is: a graph prefix must be printed following a '\n'
 783 */
 784static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 785{
 786        if ((diff_words->last_minus == 0 &&
 787                diff_words->current_plus == diff_words->plus.text.ptr) ||
 788                (diff_words->current_plus > diff_words->plus.text.ptr &&
 789                *(diff_words->current_plus - 1) == '\n')) {
 790                return 1;
 791        } else {
 792                return 0;
 793        }
 794}
 795
 796static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 797{
 798        struct diff_words_data *diff_words = priv;
 799        struct diff_words_style *style = diff_words->style;
 800        int minus_first, minus_len, plus_first, plus_len;
 801        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 802        struct diff_options *opt = diff_words->opt;
 803        struct strbuf *msgbuf;
 804        char *line_prefix = "";
 805
 806        if (line[0] != '@' || parse_hunk_header(line, len,
 807                        &minus_first, &minus_len, &plus_first, &plus_len))
 808                return;
 809
 810        assert(opt);
 811        if (opt->output_prefix) {
 812                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 813                line_prefix = msgbuf->buf;
 814        }
 815
 816        /* POSIX requires that first be decremented by one if len == 0... */
 817        if (minus_len) {
 818                minus_begin = diff_words->minus.orig[minus_first].begin;
 819                minus_end =
 820                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 821        } else
 822                minus_begin = minus_end =
 823                        diff_words->minus.orig[minus_first].end;
 824
 825        if (plus_len) {
 826                plus_begin = diff_words->plus.orig[plus_first].begin;
 827                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 828        } else
 829                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 830
 831        if (color_words_output_graph_prefix(diff_words)) {
 832                fputs(line_prefix, diff_words->opt->file);
 833        }
 834        if (diff_words->current_plus != plus_begin) {
 835                fn_out_diff_words_write_helper(diff_words->opt->file,
 836                                &style->ctx, style->newline,
 837                                plus_begin - diff_words->current_plus,
 838                                diff_words->current_plus, line_prefix);
 839                if (*(plus_begin - 1) == '\n')
 840                        fputs(line_prefix, diff_words->opt->file);
 841        }
 842        if (minus_begin != minus_end) {
 843                fn_out_diff_words_write_helper(diff_words->opt->file,
 844                                &style->old, style->newline,
 845                                minus_end - minus_begin, minus_begin,
 846                                line_prefix);
 847        }
 848        if (plus_begin != plus_end) {
 849                fn_out_diff_words_write_helper(diff_words->opt->file,
 850                                &style->new, style->newline,
 851                                plus_end - plus_begin, plus_begin,
 852                                line_prefix);
 853        }
 854
 855        diff_words->current_plus = plus_end;
 856        diff_words->last_minus = minus_first;
 857}
 858
 859/* This function starts looking at *begin, and returns 0 iff a word was found. */
 860static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 861                int *begin, int *end)
 862{
 863        if (word_regex && *begin < buffer->size) {
 864                regmatch_t match[1];
 865                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 866                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 867                                        '\n', match[0].rm_eo - match[0].rm_so);
 868                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 869                        *begin += match[0].rm_so;
 870                        return *begin >= *end;
 871                }
 872                return -1;
 873        }
 874
 875        /* find the next word */
 876        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 877                (*begin)++;
 878        if (*begin >= buffer->size)
 879                return -1;
 880
 881        /* find the end of the word */
 882        *end = *begin + 1;
 883        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 884                (*end)++;
 885
 886        return 0;
 887}
 888
 889/*
 890 * This function splits the words in buffer->text, stores the list with
 891 * newline separator into out, and saves the offsets of the original words
 892 * in buffer->orig.
 893 */
 894static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 895                regex_t *word_regex)
 896{
 897        int i, j;
 898        long alloc = 0;
 899
 900        out->size = 0;
 901        out->ptr = NULL;
 902
 903        /* fake an empty "0th" word */
 904        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 905        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 906        buffer->orig_nr = 1;
 907
 908        for (i = 0; i < buffer->text.size; i++) {
 909                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 910                        return;
 911
 912                /* store original boundaries */
 913                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 914                                buffer->orig_alloc);
 915                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 916                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 917                buffer->orig_nr++;
 918
 919                /* store one word */
 920                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 921                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 922                out->ptr[out->size + j - i] = '\n';
 923                out->size += j - i + 1;
 924
 925                i = j - 1;
 926        }
 927}
 928
 929/* this executes the word diff on the accumulated buffers */
 930static void diff_words_show(struct diff_words_data *diff_words)
 931{
 932        xpparam_t xpp;
 933        xdemitconf_t xecfg;
 934        mmfile_t minus, plus;
 935        struct diff_words_style *style = diff_words->style;
 936
 937        struct diff_options *opt = diff_words->opt;
 938        struct strbuf *msgbuf;
 939        char *line_prefix = "";
 940
 941        assert(opt);
 942        if (opt->output_prefix) {
 943                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 944                line_prefix = msgbuf->buf;
 945        }
 946
 947        /* special case: only removal */
 948        if (!diff_words->plus.text.size) {
 949                fputs(line_prefix, diff_words->opt->file);
 950                fn_out_diff_words_write_helper(diff_words->opt->file,
 951                        &style->old, style->newline,
 952                        diff_words->minus.text.size,
 953                        diff_words->minus.text.ptr, line_prefix);
 954                diff_words->minus.text.size = 0;
 955                return;
 956        }
 957
 958        diff_words->current_plus = diff_words->plus.text.ptr;
 959        diff_words->last_minus = 0;
 960
 961        memset(&xpp, 0, sizeof(xpp));
 962        memset(&xecfg, 0, sizeof(xecfg));
 963        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 964        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 965        xpp.flags = 0;
 966        /* as only the hunk header will be parsed, we need a 0-context */
 967        xecfg.ctxlen = 0;
 968        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 969                      &xpp, &xecfg);
 970        free(minus.ptr);
 971        free(plus.ptr);
 972        if (diff_words->current_plus != diff_words->plus.text.ptr +
 973                        diff_words->plus.text.size) {
 974                if (color_words_output_graph_prefix(diff_words))
 975                        fputs(line_prefix, diff_words->opt->file);
 976                fn_out_diff_words_write_helper(diff_words->opt->file,
 977                        &style->ctx, style->newline,
 978                        diff_words->plus.text.ptr + diff_words->plus.text.size
 979                        - diff_words->current_plus, diff_words->current_plus,
 980                        line_prefix);
 981        }
 982        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 983}
 984
 985/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 986static void diff_words_flush(struct emit_callback *ecbdata)
 987{
 988        if (ecbdata->diff_words->minus.text.size ||
 989            ecbdata->diff_words->plus.text.size)
 990                diff_words_show(ecbdata->diff_words);
 991}
 992
 993static void diff_filespec_load_driver(struct diff_filespec *one)
 994{
 995        /* Use already-loaded driver */
 996        if (one->driver)
 997                return;
 998
 999        if (S_ISREG(one->mode))
1000                one->driver = userdiff_find_by_path(one->path);
1001
1002        /* Fallback to default settings */
1003        if (!one->driver)
1004                one->driver = userdiff_find_by_name("default");
1005}
1006
1007static const char *userdiff_word_regex(struct diff_filespec *one)
1008{
1009        diff_filespec_load_driver(one);
1010        return one->driver->word_regex;
1011}
1012
1013static void init_diff_words_data(struct emit_callback *ecbdata,
1014                                 struct diff_options *orig_opts,
1015                                 struct diff_filespec *one,
1016                                 struct diff_filespec *two)
1017{
1018        int i;
1019        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1020        memcpy(o, orig_opts, sizeof(struct diff_options));
1021
1022        ecbdata->diff_words =
1023                xcalloc(1, sizeof(struct diff_words_data));
1024        ecbdata->diff_words->type = o->word_diff;
1025        ecbdata->diff_words->opt = o;
1026        if (!o->word_regex)
1027                o->word_regex = userdiff_word_regex(one);
1028        if (!o->word_regex)
1029                o->word_regex = userdiff_word_regex(two);
1030        if (!o->word_regex)
1031                o->word_regex = diff_word_regex_cfg;
1032        if (o->word_regex) {
1033                ecbdata->diff_words->word_regex = (regex_t *)
1034                        xmalloc(sizeof(regex_t));
1035                if (regcomp(ecbdata->diff_words->word_regex,
1036                            o->word_regex,
1037                            REG_EXTENDED | REG_NEWLINE))
1038                        die ("Invalid regular expression: %s",
1039                             o->word_regex);
1040        }
1041        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1042                if (o->word_diff == diff_words_styles[i].type) {
1043                        ecbdata->diff_words->style =
1044                                &diff_words_styles[i];
1045                        break;
1046                }
1047        }
1048        if (want_color(o->use_color)) {
1049                struct diff_words_style *st = ecbdata->diff_words->style;
1050                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1051                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1052                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
1053        }
1054}
1055
1056static void free_diff_words_data(struct emit_callback *ecbdata)
1057{
1058        if (ecbdata->diff_words) {
1059                diff_words_flush(ecbdata);
1060                free (ecbdata->diff_words->opt);
1061                free (ecbdata->diff_words->minus.text.ptr);
1062                free (ecbdata->diff_words->minus.orig);
1063                free (ecbdata->diff_words->plus.text.ptr);
1064                free (ecbdata->diff_words->plus.orig);
1065                if (ecbdata->diff_words->word_regex) {
1066                        regfree(ecbdata->diff_words->word_regex);
1067                        free(ecbdata->diff_words->word_regex);
1068                }
1069                free(ecbdata->diff_words);
1070                ecbdata->diff_words = NULL;
1071        }
1072}
1073
1074const char *diff_get_color(int diff_use_color, enum color_diff ix)
1075{
1076        if (want_color(diff_use_color))
1077                return diff_colors[ix];
1078        return "";
1079}
1080
1081static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1082{
1083        const char *cp;
1084        unsigned long allot;
1085        size_t l = len;
1086
1087        if (ecb->truncate)
1088                return ecb->truncate(line, len);
1089        cp = line;
1090        allot = l;
1091        while (0 < l) {
1092                (void) utf8_width(&cp, &l);
1093                if (!cp)
1094                        break; /* truncated in the middle? */
1095        }
1096        return allot - l;
1097}
1098
1099static void find_lno(const char *line, struct emit_callback *ecbdata)
1100{
1101        const char *p;
1102        ecbdata->lno_in_preimage = 0;
1103        ecbdata->lno_in_postimage = 0;
1104        p = strchr(line, '-');
1105        if (!p)
1106                return; /* cannot happen */
1107        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1108        p = strchr(p, '+');
1109        if (!p)
1110                return; /* cannot happen */
1111        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1112}
1113
1114static void fn_out_consume(void *priv, char *line, unsigned long len)
1115{
1116        struct emit_callback *ecbdata = priv;
1117        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1118        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1119        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1120        struct diff_options *o = ecbdata->opt;
1121        char *line_prefix = "";
1122        struct strbuf *msgbuf;
1123
1124        if (o && o->output_prefix) {
1125                msgbuf = o->output_prefix(o, o->output_prefix_data);
1126                line_prefix = msgbuf->buf;
1127        }
1128
1129        if (ecbdata->header) {
1130                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1131                strbuf_reset(ecbdata->header);
1132                ecbdata->header = NULL;
1133        }
1134        *(ecbdata->found_changesp) = 1;
1135
1136        if (ecbdata->label_path[0]) {
1137                const char *name_a_tab, *name_b_tab;
1138
1139                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1140                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1141
1142                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1143                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1144                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1145                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1146                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1147        }
1148
1149        if (diff_suppress_blank_empty
1150            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1151                line[0] = '\n';
1152                len = 1;
1153        }
1154
1155        if (line[0] == '@') {
1156                if (ecbdata->diff_words)
1157                        diff_words_flush(ecbdata);
1158                len = sane_truncate_line(ecbdata, line, len);
1159                find_lno(line, ecbdata);
1160                emit_hunk_header(ecbdata, line, len);
1161                if (line[len-1] != '\n')
1162                        putc('\n', ecbdata->opt->file);
1163                return;
1164        }
1165
1166        if (len < 1) {
1167                emit_line(ecbdata->opt, reset, reset, line, len);
1168                if (ecbdata->diff_words
1169                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1170                        fputs("~\n", ecbdata->opt->file);
1171                return;
1172        }
1173
1174        if (ecbdata->diff_words) {
1175                if (line[0] == '-') {
1176                        diff_words_append(line, len,
1177                                          &ecbdata->diff_words->minus);
1178                        return;
1179                } else if (line[0] == '+') {
1180                        diff_words_append(line, len,
1181                                          &ecbdata->diff_words->plus);
1182                        return;
1183                } else if (!prefixcmp(line, "\\ ")) {
1184                        /*
1185                         * Eat the "no newline at eof" marker as if we
1186                         * saw a "+" or "-" line with nothing on it,
1187                         * and return without diff_words_flush() to
1188                         * defer processing. If this is the end of
1189                         * preimage, more "+" lines may come after it.
1190                         */
1191                        return;
1192                }
1193                diff_words_flush(ecbdata);
1194                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1195                        emit_line(ecbdata->opt, plain, reset, line, len);
1196                        fputs("~\n", ecbdata->opt->file);
1197                } else {
1198                        /*
1199                         * Skip the prefix character, if any.  With
1200                         * diff_suppress_blank_empty, there may be
1201                         * none.
1202                         */
1203                        if (line[0] != '\n') {
1204                              line++;
1205                              len--;
1206                        }
1207                        emit_line(ecbdata->opt, plain, reset, line, len);
1208                }
1209                return;
1210        }
1211
1212        if (line[0] != '+') {
1213                const char *color =
1214                        diff_get_color(ecbdata->color_diff,
1215                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1216                ecbdata->lno_in_preimage++;
1217                if (line[0] == ' ')
1218                        ecbdata->lno_in_postimage++;
1219                emit_line(ecbdata->opt, color, reset, line, len);
1220        } else {
1221                ecbdata->lno_in_postimage++;
1222                emit_add_line(reset, ecbdata, line + 1, len - 1);
1223        }
1224}
1225
1226static char *pprint_rename(const char *a, const char *b)
1227{
1228        const char *old = a;
1229        const char *new = b;
1230        struct strbuf name = STRBUF_INIT;
1231        int pfx_length, sfx_length;
1232        int len_a = strlen(a);
1233        int len_b = strlen(b);
1234        int a_midlen, b_midlen;
1235        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1236        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1237
1238        if (qlen_a || qlen_b) {
1239                quote_c_style(a, &name, NULL, 0);
1240                strbuf_addstr(&name, " => ");
1241                quote_c_style(b, &name, NULL, 0);
1242                return strbuf_detach(&name, NULL);
1243        }
1244
1245        /* Find common prefix */
1246        pfx_length = 0;
1247        while (*old && *new && *old == *new) {
1248                if (*old == '/')
1249                        pfx_length = old - a + 1;
1250                old++;
1251                new++;
1252        }
1253
1254        /* Find common suffix */
1255        old = a + len_a;
1256        new = b + len_b;
1257        sfx_length = 0;
1258        while (a <= old && b <= new && *old == *new) {
1259                if (*old == '/')
1260                        sfx_length = len_a - (old - a);
1261                old--;
1262                new--;
1263        }
1264
1265        /*
1266         * pfx{mid-a => mid-b}sfx
1267         * {pfx-a => pfx-b}sfx
1268         * pfx{sfx-a => sfx-b}
1269         * name-a => name-b
1270         */
1271        a_midlen = len_a - pfx_length - sfx_length;
1272        b_midlen = len_b - pfx_length - sfx_length;
1273        if (a_midlen < 0)
1274                a_midlen = 0;
1275        if (b_midlen < 0)
1276                b_midlen = 0;
1277
1278        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1279        if (pfx_length + sfx_length) {
1280                strbuf_add(&name, a, pfx_length);
1281                strbuf_addch(&name, '{');
1282        }
1283        strbuf_add(&name, a + pfx_length, a_midlen);
1284        strbuf_addstr(&name, " => ");
1285        strbuf_add(&name, b + pfx_length, b_midlen);
1286        if (pfx_length + sfx_length) {
1287                strbuf_addch(&name, '}');
1288                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1289        }
1290        return strbuf_detach(&name, NULL);
1291}
1292
1293struct diffstat_t {
1294        int nr;
1295        int alloc;
1296        struct diffstat_file {
1297                char *from_name;
1298                char *name;
1299                char *print_name;
1300                unsigned is_unmerged:1;
1301                unsigned is_binary:1;
1302                unsigned is_renamed:1;
1303                uintmax_t added, deleted;
1304        } **files;
1305};
1306
1307static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1308                                          const char *name_a,
1309                                          const char *name_b)
1310{
1311        struct diffstat_file *x;
1312        x = xcalloc(sizeof (*x), 1);
1313        if (diffstat->nr == diffstat->alloc) {
1314                diffstat->alloc = alloc_nr(diffstat->alloc);
1315                diffstat->files = xrealloc(diffstat->files,
1316                                diffstat->alloc * sizeof(x));
1317        }
1318        diffstat->files[diffstat->nr++] = x;
1319        if (name_b) {
1320                x->from_name = xstrdup(name_a);
1321                x->name = xstrdup(name_b);
1322                x->is_renamed = 1;
1323        }
1324        else {
1325                x->from_name = NULL;
1326                x->name = xstrdup(name_a);
1327        }
1328        return x;
1329}
1330
1331static void diffstat_consume(void *priv, char *line, unsigned long len)
1332{
1333        struct diffstat_t *diffstat = priv;
1334        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1335
1336        if (line[0] == '+')
1337                x->added++;
1338        else if (line[0] == '-')
1339                x->deleted++;
1340}
1341
1342const char mime_boundary_leader[] = "------------";
1343
1344static int scale_linear(int it, int width, int max_change)
1345{
1346        if (!it)
1347                return 0;
1348        /*
1349         * make sure that at least one '-' or '+' is printed if
1350         * there is any change to this path. The easiest way is to
1351         * scale linearly as if the alloted width is one column shorter
1352         * than it is, and then add 1 to the result.
1353         */
1354        return 1 + (it * (width - 1) / max_change);
1355}
1356
1357static void show_name(FILE *file,
1358                      const char *prefix, const char *name, int len)
1359{
1360        fprintf(file, " %s%-*s |", prefix, len, name);
1361}
1362
1363static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1364{
1365        if (cnt <= 0)
1366                return;
1367        fprintf(file, "%s", set);
1368        while (cnt--)
1369                putc(ch, file);
1370        fprintf(file, "%s", reset);
1371}
1372
1373static void fill_print_name(struct diffstat_file *file)
1374{
1375        char *pname;
1376
1377        if (file->print_name)
1378                return;
1379
1380        if (!file->is_renamed) {
1381                struct strbuf buf = STRBUF_INIT;
1382                if (quote_c_style(file->name, &buf, NULL, 0)) {
1383                        pname = strbuf_detach(&buf, NULL);
1384                } else {
1385                        pname = file->name;
1386                        strbuf_release(&buf);
1387                }
1388        } else {
1389                pname = pprint_rename(file->from_name, file->name);
1390        }
1391        file->print_name = pname;
1392}
1393
1394int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1395{
1396        struct strbuf sb = STRBUF_INIT;
1397        int ret;
1398
1399        if (!files) {
1400                assert(insertions == 0 && deletions == 0);
1401                return fprintf(fp, "%s\n", " 0 files changed");
1402        }
1403
1404        strbuf_addf(&sb,
1405                    (files == 1) ? " %d file changed" : " %d files changed",
1406                    files);
1407
1408        /*
1409         * For binary diff, the caller may want to print "x files
1410         * changed" with insertions == 0 && deletions == 0.
1411         *
1412         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1413         * is probably less confusing (i.e skip over "2 files changed
1414         * but nothing about added/removed lines? Is this a bug in Git?").
1415         */
1416        if (insertions || deletions == 0) {
1417                /*
1418                 * TRANSLATORS: "+" in (+) is a line addition marker;
1419                 * do not translate it.
1420                 */
1421                strbuf_addf(&sb,
1422                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
1423                            insertions);
1424        }
1425
1426        if (deletions || insertions == 0) {
1427                /*
1428                 * TRANSLATORS: "-" in (-) is a line removal marker;
1429                 * do not translate it.
1430                 */
1431                strbuf_addf(&sb,
1432                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
1433                            deletions);
1434        }
1435        strbuf_addch(&sb, '\n');
1436        ret = fputs(sb.buf, fp);
1437        strbuf_release(&sb);
1438        return ret;
1439}
1440
1441static void show_stats(struct diffstat_t *data, struct diff_options *options)
1442{
1443        int i, len, add, del, adds = 0, dels = 0;
1444        uintmax_t max_change = 0, max_len = 0;
1445        int total_files = data->nr, count;
1446        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1447        const char *reset, *add_c, *del_c;
1448        const char *line_prefix = "";
1449        int extra_shown = 0;
1450        struct strbuf *msg = NULL;
1451
1452        if (data->nr == 0)
1453                return;
1454
1455        if (options->output_prefix) {
1456                msg = options->output_prefix(options, options->output_prefix_data);
1457                line_prefix = msg->buf;
1458        }
1459
1460        count = options->stat_count ? options->stat_count : data->nr;
1461
1462        reset = diff_get_color_opt(options, DIFF_RESET);
1463        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1464        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1465
1466        /*
1467         * Find the longest filename and max number of changes
1468         */
1469        for (i = 0; (i < count) && (i < data->nr); i++) {
1470                struct diffstat_file *file = data->files[i];
1471                uintmax_t change = file->added + file->deleted;
1472                if (!data->files[i]->is_renamed &&
1473                         (change == 0)) {
1474                        count++; /* not shown == room for one more */
1475                        continue;
1476                }
1477                fill_print_name(file);
1478                len = strlen(file->print_name);
1479                if (max_len < len)
1480                        max_len = len;
1481
1482                if (file->is_unmerged) {
1483                        /* "Unmerged" is 8 characters */
1484                        bin_width = bin_width < 8 ? 8 : bin_width;
1485                        continue;
1486                }
1487                if (file->is_binary) {
1488                        /* "Bin XXX -> YYY bytes" */
1489                        int w = 14 + decimal_width(file->added)
1490                                + decimal_width(file->deleted);
1491                        bin_width = bin_width < w ? w : bin_width;
1492                        /* Display change counts aligned with "Bin" */
1493                        number_width = 3;
1494                        continue;
1495                }
1496
1497                if (max_change < change)
1498                        max_change = change;
1499        }
1500        count = i; /* min(count, data->nr) */
1501
1502        /*
1503         * We have width = stat_width or term_columns() columns total.
1504         * We want a maximum of min(max_len, stat_name_width) for the name part.
1505         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1506         * We also need 1 for " " and 4 + decimal_width(max_change)
1507         * for " | NNNN " and one the empty column at the end, altogether
1508         * 6 + decimal_width(max_change).
1509         *
1510         * If there's not enough space, we will use the smaller of
1511         * stat_name_width (if set) and 5/8*width for the filename,
1512         * and the rest for constant elements + graph part, but no more
1513         * than stat_graph_width for the graph part.
1514         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1515         * for the standard terminal size).
1516         *
1517         * In other words: stat_width limits the maximum width, and
1518         * stat_name_width fixes the maximum width of the filename,
1519         * and is also used to divide available columns if there
1520         * aren't enough.
1521         *
1522         * Binary files are displayed with "Bin XXX -> YYY bytes"
1523         * instead of the change count and graph. This part is treated
1524         * similarly to the graph part, except that it is not
1525         * "scaled". If total width is too small to accomodate the
1526         * guaranteed minimum width of the filename part and the
1527         * separators and this message, this message will "overflow"
1528         * making the line longer than the maximum width.
1529         */
1530
1531        if (options->stat_width == -1)
1532                width = term_columns() - options->output_prefix_length;
1533        else
1534                width = options->stat_width ? options->stat_width : 80;
1535        number_width = decimal_width(max_change) > number_width ?
1536                decimal_width(max_change) : number_width;
1537
1538        if (options->stat_graph_width == -1)
1539                options->stat_graph_width = diff_stat_graph_width;
1540
1541        /*
1542         * Guarantee 3/8*16==6 for the graph part
1543         * and 5/8*16==10 for the filename part
1544         */
1545        if (width < 16 + 6 + number_width)
1546                width = 16 + 6 + number_width;
1547
1548        /*
1549         * First assign sizes that are wanted, ignoring available width.
1550         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1551         * starting from "XXX" should fit in graph_width.
1552         */
1553        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1554        if (options->stat_graph_width &&
1555            options->stat_graph_width < graph_width)
1556                graph_width = options->stat_graph_width;
1557
1558        name_width = (options->stat_name_width > 0 &&
1559                      options->stat_name_width < max_len) ?
1560                options->stat_name_width : max_len;
1561
1562        /*
1563         * Adjust adjustable widths not to exceed maximum width
1564         */
1565        if (name_width + number_width + 6 + graph_width > width) {
1566                if (graph_width > width * 3/8 - number_width - 6) {
1567                        graph_width = width * 3/8 - number_width - 6;
1568                        if (graph_width < 6)
1569                                graph_width = 6;
1570                }
1571
1572                if (options->stat_graph_width &&
1573                    graph_width > options->stat_graph_width)
1574                        graph_width = options->stat_graph_width;
1575                if (name_width > width - number_width - 6 - graph_width)
1576                        name_width = width - number_width - 6 - graph_width;
1577                else
1578                        graph_width = width - number_width - 6 - name_width;
1579        }
1580
1581        /*
1582         * From here name_width is the width of the name area,
1583         * and graph_width is the width of the graph area.
1584         * max_change is used to scale graph properly.
1585         */
1586        for (i = 0; i < count; i++) {
1587                const char *prefix = "";
1588                char *name = data->files[i]->print_name;
1589                uintmax_t added = data->files[i]->added;
1590                uintmax_t deleted = data->files[i]->deleted;
1591                int name_len;
1592
1593                if (!data->files[i]->is_renamed &&
1594                         (added + deleted == 0)) {
1595                        total_files--;
1596                        continue;
1597                }
1598                /*
1599                 * "scale" the filename
1600                 */
1601                len = name_width;
1602                name_len = strlen(name);
1603                if (name_width < name_len) {
1604                        char *slash;
1605                        prefix = "...";
1606                        len -= 3;
1607                        name += name_len - len;
1608                        slash = strchr(name, '/');
1609                        if (slash)
1610                                name = slash;
1611                }
1612
1613                if (data->files[i]->is_binary) {
1614                        fprintf(options->file, "%s", line_prefix);
1615                        show_name(options->file, prefix, name, len);
1616                        fprintf(options->file, " %*s", number_width, "Bin");
1617                        if (!added && !deleted) {
1618                                putc('\n', options->file);
1619                                continue;
1620                        }
1621                        fprintf(options->file, " %s%"PRIuMAX"%s",
1622                                del_c, deleted, reset);
1623                        fprintf(options->file, " -> ");
1624                        fprintf(options->file, "%s%"PRIuMAX"%s",
1625                                add_c, added, reset);
1626                        fprintf(options->file, " bytes");
1627                        fprintf(options->file, "\n");
1628                        continue;
1629                }
1630                else if (data->files[i]->is_unmerged) {
1631                        fprintf(options->file, "%s", line_prefix);
1632                        show_name(options->file, prefix, name, len);
1633                        fprintf(options->file, " Unmerged\n");
1634                        continue;
1635                }
1636
1637                /*
1638                 * scale the add/delete
1639                 */
1640                add = added;
1641                del = deleted;
1642                adds += add;
1643                dels += del;
1644
1645                if (graph_width <= max_change) {
1646                        int total = add + del;
1647
1648                        total = scale_linear(add + del, graph_width, max_change);
1649                        if (total < 2 && add && del)
1650                                /* width >= 2 due to the sanity check */
1651                                total = 2;
1652                        if (add < del) {
1653                                add = scale_linear(add, graph_width, max_change);
1654                                del = total - add;
1655                        } else {
1656                                del = scale_linear(del, graph_width, max_change);
1657                                add = total - del;
1658                        }
1659                }
1660                fprintf(options->file, "%s", line_prefix);
1661                show_name(options->file, prefix, name, len);
1662                fprintf(options->file, " %*"PRIuMAX"%s",
1663                        number_width, added + deleted,
1664                        added + deleted ? " " : "");
1665                show_graph(options->file, '+', add, add_c, reset);
1666                show_graph(options->file, '-', del, del_c, reset);
1667                fprintf(options->file, "\n");
1668        }
1669        for (i = count; i < data->nr; i++) {
1670                uintmax_t added = data->files[i]->added;
1671                uintmax_t deleted = data->files[i]->deleted;
1672                if (!data->files[i]->is_renamed &&
1673                         (added + deleted == 0)) {
1674                        total_files--;
1675                        continue;
1676                }
1677                adds += added;
1678                dels += deleted;
1679                if (!extra_shown)
1680                        fprintf(options->file, "%s ...\n", line_prefix);
1681                extra_shown = 1;
1682        }
1683        fprintf(options->file, "%s", line_prefix);
1684        print_stat_summary(options->file, total_files, adds, dels);
1685}
1686
1687static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1688{
1689        int i, adds = 0, dels = 0, total_files = data->nr;
1690
1691        if (data->nr == 0)
1692                return;
1693
1694        for (i = 0; i < data->nr; i++) {
1695                int added = data->files[i]->added;
1696                int deleted= data->files[i]->deleted;
1697
1698                if (data->files[i]->is_unmerged)
1699                        continue;
1700                if (!data->files[i]->is_renamed && (added + deleted == 0)) {
1701                        total_files--;
1702                } else if (!data->files[i]->is_binary) { /* don't count bytes */
1703                        adds += added;
1704                        dels += deleted;
1705                }
1706        }
1707        if (options->output_prefix) {
1708                struct strbuf *msg = NULL;
1709                msg = options->output_prefix(options,
1710                                options->output_prefix_data);
1711                fprintf(options->file, "%s", msg->buf);
1712        }
1713        print_stat_summary(options->file, total_files, adds, dels);
1714}
1715
1716static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1717{
1718        int i;
1719
1720        if (data->nr == 0)
1721                return;
1722
1723        for (i = 0; i < data->nr; i++) {
1724                struct diffstat_file *file = data->files[i];
1725
1726                if (options->output_prefix) {
1727                        struct strbuf *msg = NULL;
1728                        msg = options->output_prefix(options,
1729                                        options->output_prefix_data);
1730                        fprintf(options->file, "%s", msg->buf);
1731                }
1732
1733                if (file->is_binary)
1734                        fprintf(options->file, "-\t-\t");
1735                else
1736                        fprintf(options->file,
1737                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1738                                file->added, file->deleted);
1739                if (options->line_termination) {
1740                        fill_print_name(file);
1741                        if (!file->is_renamed)
1742                                write_name_quoted(file->name, options->file,
1743                                                  options->line_termination);
1744                        else {
1745                                fputs(file->print_name, options->file);
1746                                putc(options->line_termination, options->file);
1747                        }
1748                } else {
1749                        if (file->is_renamed) {
1750                                putc('\0', options->file);
1751                                write_name_quoted(file->from_name, options->file, '\0');
1752                        }
1753                        write_name_quoted(file->name, options->file, '\0');
1754                }
1755        }
1756}
1757
1758struct dirstat_file {
1759        const char *name;
1760        unsigned long changed;
1761};
1762
1763struct dirstat_dir {
1764        struct dirstat_file *files;
1765        int alloc, nr, permille, cumulative;
1766};
1767
1768static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1769                unsigned long changed, const char *base, int baselen)
1770{
1771        unsigned long this_dir = 0;
1772        unsigned int sources = 0;
1773        const char *line_prefix = "";
1774        struct strbuf *msg = NULL;
1775
1776        if (opt->output_prefix) {
1777                msg = opt->output_prefix(opt, opt->output_prefix_data);
1778                line_prefix = msg->buf;
1779        }
1780
1781        while (dir->nr) {
1782                struct dirstat_file *f = dir->files;
1783                int namelen = strlen(f->name);
1784                unsigned long this;
1785                char *slash;
1786
1787                if (namelen < baselen)
1788                        break;
1789                if (memcmp(f->name, base, baselen))
1790                        break;
1791                slash = strchr(f->name + baselen, '/');
1792                if (slash) {
1793                        int newbaselen = slash + 1 - f->name;
1794                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1795                        sources++;
1796                } else {
1797                        this = f->changed;
1798                        dir->files++;
1799                        dir->nr--;
1800                        sources += 2;
1801                }
1802                this_dir += this;
1803        }
1804
1805        /*
1806         * We don't report dirstat's for
1807         *  - the top level
1808         *  - or cases where everything came from a single directory
1809         *    under this directory (sources == 1).
1810         */
1811        if (baselen && sources != 1) {
1812                if (this_dir) {
1813                        int permille = this_dir * 1000 / changed;
1814                        if (permille >= dir->permille) {
1815                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1816                                        permille / 10, permille % 10, baselen, base);
1817                                if (!dir->cumulative)
1818                                        return 0;
1819                        }
1820                }
1821        }
1822        return this_dir;
1823}
1824
1825static int dirstat_compare(const void *_a, const void *_b)
1826{
1827        const struct dirstat_file *a = _a;
1828        const struct dirstat_file *b = _b;
1829        return strcmp(a->name, b->name);
1830}
1831
1832static void show_dirstat(struct diff_options *options)
1833{
1834        int i;
1835        unsigned long changed;
1836        struct dirstat_dir dir;
1837        struct diff_queue_struct *q = &diff_queued_diff;
1838
1839        dir.files = NULL;
1840        dir.alloc = 0;
1841        dir.nr = 0;
1842        dir.permille = options->dirstat_permille;
1843        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1844
1845        changed = 0;
1846        for (i = 0; i < q->nr; i++) {
1847                struct diff_filepair *p = q->queue[i];
1848                const char *name;
1849                unsigned long copied, added, damage;
1850                int content_changed;
1851
1852                name = p->two->path ? p->two->path : p->one->path;
1853
1854                if (p->one->sha1_valid && p->two->sha1_valid)
1855                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1856                else
1857                        content_changed = 1;
1858
1859                if (!content_changed) {
1860                        /*
1861                         * The SHA1 has not changed, so pre-/post-content is
1862                         * identical. We can therefore skip looking at the
1863                         * file contents altogether.
1864                         */
1865                        damage = 0;
1866                        goto found_damage;
1867                }
1868
1869                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1870                        /*
1871                         * In --dirstat-by-file mode, we don't really need to
1872                         * look at the actual file contents at all.
1873                         * The fact that the SHA1 changed is enough for us to
1874                         * add this file to the list of results
1875                         * (with each file contributing equal damage).
1876                         */
1877                        damage = 1;
1878                        goto found_damage;
1879                }
1880
1881                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1882                        diff_populate_filespec(p->one, 0);
1883                        diff_populate_filespec(p->two, 0);
1884                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1885                                               &copied, &added);
1886                        diff_free_filespec_data(p->one);
1887                        diff_free_filespec_data(p->two);
1888                } else if (DIFF_FILE_VALID(p->one)) {
1889                        diff_populate_filespec(p->one, 1);
1890                        copied = added = 0;
1891                        diff_free_filespec_data(p->one);
1892                } else if (DIFF_FILE_VALID(p->two)) {
1893                        diff_populate_filespec(p->two, 1);
1894                        copied = 0;
1895                        added = p->two->size;
1896                        diff_free_filespec_data(p->two);
1897                } else
1898                        continue;
1899
1900                /*
1901                 * Original minus copied is the removed material,
1902                 * added is the new material.  They are both damages
1903                 * made to the preimage.
1904                 * If the resulting damage is zero, we know that
1905                 * diffcore_count_changes() considers the two entries to
1906                 * be identical, but since content_changed is true, we
1907                 * know that there must have been _some_ kind of change,
1908                 * so we force all entries to have damage > 0.
1909                 */
1910                damage = (p->one->size - copied) + added;
1911                if (!damage)
1912                        damage = 1;
1913
1914found_damage:
1915                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1916                dir.files[dir.nr].name = name;
1917                dir.files[dir.nr].changed = damage;
1918                changed += damage;
1919                dir.nr++;
1920        }
1921
1922        /* This can happen even with many files, if everything was renames */
1923        if (!changed)
1924                return;
1925
1926        /* Show all directories with more than x% of the changes */
1927        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1928        gather_dirstat(options, &dir, changed, "", 0);
1929}
1930
1931static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1932{
1933        int i;
1934        unsigned long changed;
1935        struct dirstat_dir dir;
1936
1937        if (data->nr == 0)
1938                return;
1939
1940        dir.files = NULL;
1941        dir.alloc = 0;
1942        dir.nr = 0;
1943        dir.permille = options->dirstat_permille;
1944        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1945
1946        changed = 0;
1947        for (i = 0; i < data->nr; i++) {
1948                struct diffstat_file *file = data->files[i];
1949                unsigned long damage = file->added + file->deleted;
1950                if (file->is_binary)
1951                        /*
1952                         * binary files counts bytes, not lines. Must find some
1953                         * way to normalize binary bytes vs. textual lines.
1954                         * The following heuristic assumes that there are 64
1955                         * bytes per "line".
1956                         * This is stupid and ugly, but very cheap...
1957                         */
1958                        damage = (damage + 63) / 64;
1959                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1960                dir.files[dir.nr].name = file->name;
1961                dir.files[dir.nr].changed = damage;
1962                changed += damage;
1963                dir.nr++;
1964        }
1965
1966        /* This can happen even with many files, if everything was renames */
1967        if (!changed)
1968                return;
1969
1970        /* Show all directories with more than x% of the changes */
1971        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1972        gather_dirstat(options, &dir, changed, "", 0);
1973}
1974
1975static void free_diffstat_info(struct diffstat_t *diffstat)
1976{
1977        int i;
1978        for (i = 0; i < diffstat->nr; i++) {
1979                struct diffstat_file *f = diffstat->files[i];
1980                if (f->name != f->print_name)
1981                        free(f->print_name);
1982                free(f->name);
1983                free(f->from_name);
1984                free(f);
1985        }
1986        free(diffstat->files);
1987}
1988
1989struct checkdiff_t {
1990        const char *filename;
1991        int lineno;
1992        int conflict_marker_size;
1993        struct diff_options *o;
1994        unsigned ws_rule;
1995        unsigned status;
1996};
1997
1998static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1999{
2000        char firstchar;
2001        int cnt;
2002
2003        if (len < marker_size + 1)
2004                return 0;
2005        firstchar = line[0];
2006        switch (firstchar) {
2007        case '=': case '>': case '<': case '|':
2008                break;
2009        default:
2010                return 0;
2011        }
2012        for (cnt = 1; cnt < marker_size; cnt++)
2013                if (line[cnt] != firstchar)
2014                        return 0;
2015        /* line[1] thru line[marker_size-1] are same as firstchar */
2016        if (len < marker_size + 1 || !isspace(line[marker_size]))
2017                return 0;
2018        return 1;
2019}
2020
2021static void checkdiff_consume(void *priv, char *line, unsigned long len)
2022{
2023        struct checkdiff_t *data = priv;
2024        int marker_size = data->conflict_marker_size;
2025        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2026        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2027        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2028        char *err;
2029        char *line_prefix = "";
2030        struct strbuf *msgbuf;
2031
2032        assert(data->o);
2033        if (data->o->output_prefix) {
2034                msgbuf = data->o->output_prefix(data->o,
2035                        data->o->output_prefix_data);
2036                line_prefix = msgbuf->buf;
2037        }
2038
2039        if (line[0] == '+') {
2040                unsigned bad;
2041                data->lineno++;
2042                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2043                        data->status |= 1;
2044                        fprintf(data->o->file,
2045                                "%s%s:%d: leftover conflict marker\n",
2046                                line_prefix, data->filename, data->lineno);
2047                }
2048                bad = ws_check(line + 1, len - 1, data->ws_rule);
2049                if (!bad)
2050                        return;
2051                data->status |= bad;
2052                err = whitespace_error_string(bad);
2053                fprintf(data->o->file, "%s%s:%d: %s.\n",
2054                        line_prefix, data->filename, data->lineno, err);
2055                free(err);
2056                emit_line(data->o, set, reset, line, 1);
2057                ws_check_emit(line + 1, len - 1, data->ws_rule,
2058                              data->o->file, set, reset, ws);
2059        } else if (line[0] == ' ') {
2060                data->lineno++;
2061        } else if (line[0] == '@') {
2062                char *plus = strchr(line, '+');
2063                if (plus)
2064                        data->lineno = strtol(plus, NULL, 10) - 1;
2065                else
2066                        die("invalid diff");
2067        }
2068}
2069
2070static unsigned char *deflate_it(char *data,
2071                                 unsigned long size,
2072                                 unsigned long *result_size)
2073{
2074        int bound;
2075        unsigned char *deflated;
2076        git_zstream stream;
2077
2078        memset(&stream, 0, sizeof(stream));
2079        git_deflate_init(&stream, zlib_compression_level);
2080        bound = git_deflate_bound(&stream, size);
2081        deflated = xmalloc(bound);
2082        stream.next_out = deflated;
2083        stream.avail_out = bound;
2084
2085        stream.next_in = (unsigned char *)data;
2086        stream.avail_in = size;
2087        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2088                ; /* nothing */
2089        git_deflate_end(&stream);
2090        *result_size = stream.total_out;
2091        return deflated;
2092}
2093
2094static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2095{
2096        void *cp;
2097        void *delta;
2098        void *deflated;
2099        void *data;
2100        unsigned long orig_size;
2101        unsigned long delta_size;
2102        unsigned long deflate_size;
2103        unsigned long data_size;
2104
2105        /* We could do deflated delta, or we could do just deflated two,
2106         * whichever is smaller.
2107         */
2108        delta = NULL;
2109        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2110        if (one->size && two->size) {
2111                delta = diff_delta(one->ptr, one->size,
2112                                   two->ptr, two->size,
2113                                   &delta_size, deflate_size);
2114                if (delta) {
2115                        void *to_free = delta;
2116                        orig_size = delta_size;
2117                        delta = deflate_it(delta, delta_size, &delta_size);
2118                        free(to_free);
2119                }
2120        }
2121
2122        if (delta && delta_size < deflate_size) {
2123                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2124                free(deflated);
2125                data = delta;
2126                data_size = delta_size;
2127        }
2128        else {
2129                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2130                free(delta);
2131                data = deflated;
2132                data_size = deflate_size;
2133        }
2134
2135        /* emit data encoded in base85 */
2136        cp = data;
2137        while (data_size) {
2138                int bytes = (52 < data_size) ? 52 : data_size;
2139                char line[70];
2140                data_size -= bytes;
2141                if (bytes <= 26)
2142                        line[0] = bytes + 'A' - 1;
2143                else
2144                        line[0] = bytes - 26 + 'a' - 1;
2145                encode_85(line + 1, cp, bytes);
2146                cp = (char *) cp + bytes;
2147                fprintf(file, "%s", prefix);
2148                fputs(line, file);
2149                fputc('\n', file);
2150        }
2151        fprintf(file, "%s\n", prefix);
2152        free(data);
2153}
2154
2155static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2156{
2157        fprintf(file, "%sGIT binary patch\n", prefix);
2158        emit_binary_diff_body(file, one, two, prefix);
2159        emit_binary_diff_body(file, two, one, prefix);
2160}
2161
2162int diff_filespec_is_binary(struct diff_filespec *one)
2163{
2164        if (one->is_binary == -1) {
2165                diff_filespec_load_driver(one);
2166                if (one->driver->binary != -1)
2167                        one->is_binary = one->driver->binary;
2168                else {
2169                        if (!one->data && DIFF_FILE_VALID(one))
2170                                diff_populate_filespec(one, 0);
2171                        if (one->data)
2172                                one->is_binary = buffer_is_binary(one->data,
2173                                                one->size);
2174                        if (one->is_binary == -1)
2175                                one->is_binary = 0;
2176                }
2177        }
2178        return one->is_binary;
2179}
2180
2181static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2182{
2183        diff_filespec_load_driver(one);
2184        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2185}
2186
2187void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2188{
2189        if (!options->a_prefix)
2190                options->a_prefix = a;
2191        if (!options->b_prefix)
2192                options->b_prefix = b;
2193}
2194
2195struct userdiff_driver *get_textconv(struct diff_filespec *one)
2196{
2197        if (!DIFF_FILE_VALID(one))
2198                return NULL;
2199
2200        diff_filespec_load_driver(one);
2201        return userdiff_get_textconv(one->driver);
2202}
2203
2204static void builtin_diff(const char *name_a,
2205                         const char *name_b,
2206                         struct diff_filespec *one,
2207                         struct diff_filespec *two,
2208                         const char *xfrm_msg,
2209                         int must_show_header,
2210                         struct diff_options *o,
2211                         int complete_rewrite)
2212{
2213        mmfile_t mf1, mf2;
2214        const char *lbl[2];
2215        char *a_one, *b_two;
2216        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2217        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2218        const char *a_prefix, *b_prefix;
2219        struct userdiff_driver *textconv_one = NULL;
2220        struct userdiff_driver *textconv_two = NULL;
2221        struct strbuf header = STRBUF_INIT;
2222        struct strbuf *msgbuf;
2223        char *line_prefix = "";
2224
2225        if (o->output_prefix) {
2226                msgbuf = o->output_prefix(o, o->output_prefix_data);
2227                line_prefix = msgbuf->buf;
2228        }
2229
2230        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2231                        (!one->mode || S_ISGITLINK(one->mode)) &&
2232                        (!two->mode || S_ISGITLINK(two->mode))) {
2233                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2234                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2235                show_submodule_summary(o->file, one ? one->path : two->path,
2236                                one->sha1, two->sha1, two->dirty_submodule,
2237                                del, add, reset);
2238                return;
2239        }
2240
2241        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2242                textconv_one = get_textconv(one);
2243                textconv_two = get_textconv(two);
2244        }
2245
2246        diff_set_mnemonic_prefix(o, "a/", "b/");
2247        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2248                a_prefix = o->b_prefix;
2249                b_prefix = o->a_prefix;
2250        } else {
2251                a_prefix = o->a_prefix;
2252                b_prefix = o->b_prefix;
2253        }
2254
2255        /* Never use a non-valid filename anywhere if at all possible */
2256        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2257        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2258
2259        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2260        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2261        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2262        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2263        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2264        if (lbl[0][0] == '/') {
2265                /* /dev/null */
2266                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2267                if (xfrm_msg)
2268                        strbuf_addstr(&header, xfrm_msg);
2269                must_show_header = 1;
2270        }
2271        else if (lbl[1][0] == '/') {
2272                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2273                if (xfrm_msg)
2274                        strbuf_addstr(&header, xfrm_msg);
2275                must_show_header = 1;
2276        }
2277        else {
2278                if (one->mode != two->mode) {
2279                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2280                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2281                        must_show_header = 1;
2282                }
2283                if (xfrm_msg)
2284                        strbuf_addstr(&header, xfrm_msg);
2285
2286                /*
2287                 * we do not run diff between different kind
2288                 * of objects.
2289                 */
2290                if ((one->mode ^ two->mode) & S_IFMT)
2291                        goto free_ab_and_return;
2292                if (complete_rewrite &&
2293                    (textconv_one || !diff_filespec_is_binary(one)) &&
2294                    (textconv_two || !diff_filespec_is_binary(two))) {
2295                        fprintf(o->file, "%s", header.buf);
2296                        strbuf_reset(&header);
2297                        emit_rewrite_diff(name_a, name_b, one, two,
2298                                                textconv_one, textconv_two, o);
2299                        o->found_changes = 1;
2300                        goto free_ab_and_return;
2301                }
2302        }
2303
2304        if (o->irreversible_delete && lbl[1][0] == '/') {
2305                fprintf(o->file, "%s", header.buf);
2306                strbuf_reset(&header);
2307                goto free_ab_and_return;
2308        } else if (!DIFF_OPT_TST(o, TEXT) &&
2309            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2310              (!textconv_two && diff_filespec_is_binary(two)) )) {
2311                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2312                        die("unable to read files to diff");
2313                /* Quite common confusing case */
2314                if (mf1.size == mf2.size &&
2315                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2316                        if (must_show_header)
2317                                fprintf(o->file, "%s", header.buf);
2318                        goto free_ab_and_return;
2319                }
2320                fprintf(o->file, "%s", header.buf);
2321                strbuf_reset(&header);
2322                if (DIFF_OPT_TST(o, BINARY))
2323                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2324                else
2325                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2326                                line_prefix, lbl[0], lbl[1]);
2327                o->found_changes = 1;
2328        } else {
2329                /* Crazy xdl interfaces.. */
2330                const char *diffopts = getenv("GIT_DIFF_OPTS");
2331                xpparam_t xpp;
2332                xdemitconf_t xecfg;
2333                struct emit_callback ecbdata;
2334                const struct userdiff_funcname *pe;
2335
2336                if (must_show_header) {
2337                        fprintf(o->file, "%s", header.buf);
2338                        strbuf_reset(&header);
2339                }
2340
2341                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2342                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2343
2344                pe = diff_funcname_pattern(one);
2345                if (!pe)
2346                        pe = diff_funcname_pattern(two);
2347
2348                memset(&xpp, 0, sizeof(xpp));
2349                memset(&xecfg, 0, sizeof(xecfg));
2350                memset(&ecbdata, 0, sizeof(ecbdata));
2351                ecbdata.label_path = lbl;
2352                ecbdata.color_diff = want_color(o->use_color);
2353                ecbdata.found_changesp = &o->found_changes;
2354                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2355                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2356                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2357                ecbdata.opt = o;
2358                ecbdata.header = header.len ? &header : NULL;
2359                xpp.flags = o->xdl_opts;
2360                xecfg.ctxlen = o->context;
2361                xecfg.interhunkctxlen = o->interhunkcontext;
2362                xecfg.flags = XDL_EMIT_FUNCNAMES;
2363                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2364                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2365                if (pe)
2366                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2367                if (!diffopts)
2368                        ;
2369                else if (!prefixcmp(diffopts, "--unified="))
2370                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2371                else if (!prefixcmp(diffopts, "-u"))
2372                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2373                if (o->word_diff)
2374                        init_diff_words_data(&ecbdata, o, one, two);
2375                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2376                              &xpp, &xecfg);
2377                if (o->word_diff)
2378                        free_diff_words_data(&ecbdata);
2379                if (textconv_one)
2380                        free(mf1.ptr);
2381                if (textconv_two)
2382                        free(mf2.ptr);
2383                xdiff_clear_find_func(&xecfg);
2384        }
2385
2386 free_ab_and_return:
2387        strbuf_release(&header);
2388        diff_free_filespec_data(one);
2389        diff_free_filespec_data(two);
2390        free(a_one);
2391        free(b_two);
2392        return;
2393}
2394
2395static void builtin_diffstat(const char *name_a, const char *name_b,
2396                             struct diff_filespec *one,
2397                             struct diff_filespec *two,
2398                             struct diffstat_t *diffstat,
2399                             struct diff_options *o,
2400                             int complete_rewrite)
2401{
2402        mmfile_t mf1, mf2;
2403        struct diffstat_file *data;
2404        int same_contents;
2405
2406        data = diffstat_add(diffstat, name_a, name_b);
2407
2408        if (!one || !two) {
2409                data->is_unmerged = 1;
2410                return;
2411        }
2412
2413        same_contents = !hashcmp(one->sha1, two->sha1);
2414
2415        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2416                data->is_binary = 1;
2417                if (same_contents) {
2418                        data->added = 0;
2419                        data->deleted = 0;
2420                } else {
2421                        data->added = diff_filespec_size(two);
2422                        data->deleted = diff_filespec_size(one);
2423                }
2424        }
2425
2426        else if (complete_rewrite) {
2427                diff_populate_filespec(one, 0);
2428                diff_populate_filespec(two, 0);
2429                data->deleted = count_lines(one->data, one->size);
2430                data->added = count_lines(two->data, two->size);
2431        }
2432
2433        else if (!same_contents) {
2434                /* Crazy xdl interfaces.. */
2435                xpparam_t xpp;
2436                xdemitconf_t xecfg;
2437
2438                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2439                        die("unable to read files to diff");
2440
2441                memset(&xpp, 0, sizeof(xpp));
2442                memset(&xecfg, 0, sizeof(xecfg));
2443                xpp.flags = o->xdl_opts;
2444                xecfg.ctxlen = o->context;
2445                xecfg.interhunkctxlen = o->interhunkcontext;
2446                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2447                              &xpp, &xecfg);
2448        }
2449
2450        diff_free_filespec_data(one);
2451        diff_free_filespec_data(two);
2452}
2453
2454static void builtin_checkdiff(const char *name_a, const char *name_b,
2455                              const char *attr_path,
2456                              struct diff_filespec *one,
2457                              struct diff_filespec *two,
2458                              struct diff_options *o)
2459{
2460        mmfile_t mf1, mf2;
2461        struct checkdiff_t data;
2462
2463        if (!two)
2464                return;
2465
2466        memset(&data, 0, sizeof(data));
2467        data.filename = name_b ? name_b : name_a;
2468        data.lineno = 0;
2469        data.o = o;
2470        data.ws_rule = whitespace_rule(attr_path);
2471        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2472
2473        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2474                die("unable to read files to diff");
2475
2476        /*
2477         * All the other codepaths check both sides, but not checking
2478         * the "old" side here is deliberate.  We are checking the newly
2479         * introduced changes, and as long as the "new" side is text, we
2480         * can and should check what it introduces.
2481         */
2482        if (diff_filespec_is_binary(two))
2483                goto free_and_return;
2484        else {
2485                /* Crazy xdl interfaces.. */
2486                xpparam_t xpp;
2487                xdemitconf_t xecfg;
2488
2489                memset(&xpp, 0, sizeof(xpp));
2490                memset(&xecfg, 0, sizeof(xecfg));
2491                xecfg.ctxlen = 1; /* at least one context line */
2492                xpp.flags = 0;
2493                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2494                              &xpp, &xecfg);
2495
2496                if (data.ws_rule & WS_BLANK_AT_EOF) {
2497                        struct emit_callback ecbdata;
2498                        int blank_at_eof;
2499
2500                        ecbdata.ws_rule = data.ws_rule;
2501                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2502                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2503
2504                        if (blank_at_eof) {
2505                                static char *err;
2506                                if (!err)
2507                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2508                                fprintf(o->file, "%s:%d: %s.\n",
2509                                        data.filename, blank_at_eof, err);
2510                                data.status = 1; /* report errors */
2511                        }
2512                }
2513        }
2514 free_and_return:
2515        diff_free_filespec_data(one);
2516        diff_free_filespec_data(two);
2517        if (data.status)
2518                DIFF_OPT_SET(o, CHECK_FAILED);
2519}
2520
2521struct diff_filespec *alloc_filespec(const char *path)
2522{
2523        int namelen = strlen(path);
2524        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2525
2526        memset(spec, 0, sizeof(*spec));
2527        spec->path = (char *)(spec + 1);
2528        memcpy(spec->path, path, namelen+1);
2529        spec->count = 1;
2530        spec->is_binary = -1;
2531        return spec;
2532}
2533
2534void free_filespec(struct diff_filespec *spec)
2535{
2536        if (!--spec->count) {
2537                diff_free_filespec_data(spec);
2538                free(spec);
2539        }
2540}
2541
2542void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2543                   int sha1_valid, unsigned short mode)
2544{
2545        if (mode) {
2546                spec->mode = canon_mode(mode);
2547                hashcpy(spec->sha1, sha1);
2548                spec->sha1_valid = sha1_valid;
2549        }
2550}
2551
2552/*
2553 * Given a name and sha1 pair, if the index tells us the file in
2554 * the work tree has that object contents, return true, so that
2555 * prepare_temp_file() does not have to inflate and extract.
2556 */
2557static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2558{
2559        struct cache_entry *ce;
2560        struct stat st;
2561        int pos, len;
2562
2563        /*
2564         * We do not read the cache ourselves here, because the
2565         * benchmark with my previous version that always reads cache
2566         * shows that it makes things worse for diff-tree comparing
2567         * two linux-2.6 kernel trees in an already checked out work
2568         * tree.  This is because most diff-tree comparisons deal with
2569         * only a small number of files, while reading the cache is
2570         * expensive for a large project, and its cost outweighs the
2571         * savings we get by not inflating the object to a temporary
2572         * file.  Practically, this code only helps when we are used
2573         * by diff-cache --cached, which does read the cache before
2574         * calling us.
2575         */
2576        if (!active_cache)
2577                return 0;
2578
2579        /* We want to avoid the working directory if our caller
2580         * doesn't need the data in a normal file, this system
2581         * is rather slow with its stat/open/mmap/close syscalls,
2582         * and the object is contained in a pack file.  The pack
2583         * is probably already open and will be faster to obtain
2584         * the data through than the working directory.  Loose
2585         * objects however would tend to be slower as they need
2586         * to be individually opened and inflated.
2587         */
2588        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2589                return 0;
2590
2591        len = strlen(name);
2592        pos = cache_name_pos(name, len);
2593        if (pos < 0)
2594                return 0;
2595        ce = active_cache[pos];
2596
2597        /*
2598         * This is not the sha1 we are looking for, or
2599         * unreusable because it is not a regular file.
2600         */
2601        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2602                return 0;
2603
2604        /*
2605         * If ce is marked as "assume unchanged", there is no
2606         * guarantee that work tree matches what we are looking for.
2607         */
2608        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2609                return 0;
2610
2611        /*
2612         * If ce matches the file in the work tree, we can reuse it.
2613         */
2614        if (ce_uptodate(ce) ||
2615            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2616                return 1;
2617
2618        return 0;
2619}
2620
2621static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2622{
2623        int len;
2624        char *data = xmalloc(100), *dirty = "";
2625
2626        /* Are we looking at the work tree? */
2627        if (s->dirty_submodule)
2628                dirty = "-dirty";
2629
2630        len = snprintf(data, 100,
2631                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2632        s->data = data;
2633        s->size = len;
2634        s->should_free = 1;
2635        if (size_only) {
2636                s->data = NULL;
2637                free(data);
2638        }
2639        return 0;
2640}
2641
2642/*
2643 * While doing rename detection and pickaxe operation, we may need to
2644 * grab the data for the blob (or file) for our own in-core comparison.
2645 * diff_filespec has data and size fields for this purpose.
2646 */
2647int diff_populate_filespec(struct diff_filespec *s, int size_only)
2648{
2649        int err = 0;
2650        if (!DIFF_FILE_VALID(s))
2651                die("internal error: asking to populate invalid file.");
2652        if (S_ISDIR(s->mode))
2653                return -1;
2654
2655        if (s->data)
2656                return 0;
2657
2658        if (size_only && 0 < s->size)
2659                return 0;
2660
2661        if (S_ISGITLINK(s->mode))
2662                return diff_populate_gitlink(s, size_only);
2663
2664        if (!s->sha1_valid ||
2665            reuse_worktree_file(s->path, s->sha1, 0)) {
2666                struct strbuf buf = STRBUF_INIT;
2667                struct stat st;
2668                int fd;
2669
2670                if (lstat(s->path, &st) < 0) {
2671                        if (errno == ENOENT) {
2672                        err_empty:
2673                                err = -1;
2674                        empty:
2675                                s->data = (char *)"";
2676                                s->size = 0;
2677                                return err;
2678                        }
2679                }
2680                s->size = xsize_t(st.st_size);
2681                if (!s->size)
2682                        goto empty;
2683                if (S_ISLNK(st.st_mode)) {
2684                        struct strbuf sb = STRBUF_INIT;
2685
2686                        if (strbuf_readlink(&sb, s->path, s->size))
2687                                goto err_empty;
2688                        s->size = sb.len;
2689                        s->data = strbuf_detach(&sb, NULL);
2690                        s->should_free = 1;
2691                        return 0;
2692                }
2693                if (size_only)
2694                        return 0;
2695                fd = open(s->path, O_RDONLY);
2696                if (fd < 0)
2697                        goto err_empty;
2698                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2699                close(fd);
2700                s->should_munmap = 1;
2701
2702                /*
2703                 * Convert from working tree format to canonical git format
2704                 */
2705                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2706                        size_t size = 0;
2707                        munmap(s->data, s->size);
2708                        s->should_munmap = 0;
2709                        s->data = strbuf_detach(&buf, &size);
2710                        s->size = size;
2711                        s->should_free = 1;
2712                }
2713        }
2714        else {
2715                enum object_type type;
2716                if (size_only) {
2717                        type = sha1_object_info(s->sha1, &s->size);
2718                        if (type < 0)
2719                                die("unable to read %s", sha1_to_hex(s->sha1));
2720                } else {
2721                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2722                        if (!s->data)
2723                                die("unable to read %s", sha1_to_hex(s->sha1));
2724                        s->should_free = 1;
2725                }
2726        }
2727        return 0;
2728}
2729
2730void diff_free_filespec_blob(struct diff_filespec *s)
2731{
2732        if (s->should_free)
2733                free(s->data);
2734        else if (s->should_munmap)
2735                munmap(s->data, s->size);
2736
2737        if (s->should_free || s->should_munmap) {
2738                s->should_free = s->should_munmap = 0;
2739                s->data = NULL;
2740        }
2741}
2742
2743void diff_free_filespec_data(struct diff_filespec *s)
2744{
2745        diff_free_filespec_blob(s);
2746        free(s->cnt_data);
2747        s->cnt_data = NULL;
2748}
2749
2750static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2751                           void *blob,
2752                           unsigned long size,
2753                           const unsigned char *sha1,
2754                           int mode)
2755{
2756        int fd;
2757        struct strbuf buf = STRBUF_INIT;
2758        struct strbuf template = STRBUF_INIT;
2759        char *path_dup = xstrdup(path);
2760        const char *base = basename(path_dup);
2761
2762        /* Generate "XXXXXX_basename.ext" */
2763        strbuf_addstr(&template, "XXXXXX_");
2764        strbuf_addstr(&template, base);
2765
2766        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2767                        strlen(base) + 1);
2768        if (fd < 0)
2769                die_errno("unable to create temp-file");
2770        if (convert_to_working_tree(path,
2771                        (const char *)blob, (size_t)size, &buf)) {
2772                blob = buf.buf;
2773                size = buf.len;
2774        }
2775        if (write_in_full(fd, blob, size) != size)
2776                die_errno("unable to write temp-file");
2777        close(fd);
2778        temp->name = temp->tmp_path;
2779        strcpy(temp->hex, sha1_to_hex(sha1));
2780        temp->hex[40] = 0;
2781        sprintf(temp->mode, "%06o", mode);
2782        strbuf_release(&buf);
2783        strbuf_release(&template);
2784        free(path_dup);
2785}
2786
2787static struct diff_tempfile *prepare_temp_file(const char *name,
2788                struct diff_filespec *one)
2789{
2790        struct diff_tempfile *temp = claim_diff_tempfile();
2791
2792        if (!DIFF_FILE_VALID(one)) {
2793        not_a_valid_file:
2794                /* A '-' entry produces this for file-2, and
2795                 * a '+' entry produces this for file-1.
2796                 */
2797                temp->name = "/dev/null";
2798                strcpy(temp->hex, ".");
2799                strcpy(temp->mode, ".");
2800                return temp;
2801        }
2802
2803        if (!remove_tempfile_installed) {
2804                atexit(remove_tempfile);
2805                sigchain_push_common(remove_tempfile_on_signal);
2806                remove_tempfile_installed = 1;
2807        }
2808
2809        if (!one->sha1_valid ||
2810            reuse_worktree_file(name, one->sha1, 1)) {
2811                struct stat st;
2812                if (lstat(name, &st) < 0) {
2813                        if (errno == ENOENT)
2814                                goto not_a_valid_file;
2815                        die_errno("stat(%s)", name);
2816                }
2817                if (S_ISLNK(st.st_mode)) {
2818                        struct strbuf sb = STRBUF_INIT;
2819                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2820                                die_errno("readlink(%s)", name);
2821                        prep_temp_blob(name, temp, sb.buf, sb.len,
2822                                       (one->sha1_valid ?
2823                                        one->sha1 : null_sha1),
2824                                       (one->sha1_valid ?
2825                                        one->mode : S_IFLNK));
2826                        strbuf_release(&sb);
2827                }
2828                else {
2829                        /* we can borrow from the file in the work tree */
2830                        temp->name = name;
2831                        if (!one->sha1_valid)
2832                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2833                        else
2834                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2835                        /* Even though we may sometimes borrow the
2836                         * contents from the work tree, we always want
2837                         * one->mode.  mode is trustworthy even when
2838                         * !(one->sha1_valid), as long as
2839                         * DIFF_FILE_VALID(one).
2840                         */
2841                        sprintf(temp->mode, "%06o", one->mode);
2842                }
2843                return temp;
2844        }
2845        else {
2846                if (diff_populate_filespec(one, 0))
2847                        die("cannot read data blob for %s", one->path);
2848                prep_temp_blob(name, temp, one->data, one->size,
2849                               one->sha1, one->mode);
2850        }
2851        return temp;
2852}
2853
2854/* An external diff command takes:
2855 *
2856 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2857 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2858 *
2859 */
2860static void run_external_diff(const char *pgm,
2861                              const char *name,
2862                              const char *other,
2863                              struct diff_filespec *one,
2864                              struct diff_filespec *two,
2865                              const char *xfrm_msg,
2866                              int complete_rewrite)
2867{
2868        const char *spawn_arg[10];
2869        int retval;
2870        const char **arg = &spawn_arg[0];
2871
2872        if (one && two) {
2873                struct diff_tempfile *temp_one, *temp_two;
2874                const char *othername = (other ? other : name);
2875                temp_one = prepare_temp_file(name, one);
2876                temp_two = prepare_temp_file(othername, two);
2877                *arg++ = pgm;
2878                *arg++ = name;
2879                *arg++ = temp_one->name;
2880                *arg++ = temp_one->hex;
2881                *arg++ = temp_one->mode;
2882                *arg++ = temp_two->name;
2883                *arg++ = temp_two->hex;
2884                *arg++ = temp_two->mode;
2885                if (other) {
2886                        *arg++ = other;
2887                        *arg++ = xfrm_msg;
2888                }
2889        } else {
2890                *arg++ = pgm;
2891                *arg++ = name;
2892        }
2893        *arg = NULL;
2894        fflush(NULL);
2895        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2896        remove_tempfile();
2897        if (retval) {
2898                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2899                exit(1);
2900        }
2901}
2902
2903static int similarity_index(struct diff_filepair *p)
2904{
2905        return p->score * 100 / MAX_SCORE;
2906}
2907
2908static void fill_metainfo(struct strbuf *msg,
2909                          const char *name,
2910                          const char *other,
2911                          struct diff_filespec *one,
2912                          struct diff_filespec *two,
2913                          struct diff_options *o,
2914                          struct diff_filepair *p,
2915                          int *must_show_header,
2916                          int use_color)
2917{
2918        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2919        const char *reset = diff_get_color(use_color, DIFF_RESET);
2920        struct strbuf *msgbuf;
2921        char *line_prefix = "";
2922
2923        *must_show_header = 1;
2924        if (o->output_prefix) {
2925                msgbuf = o->output_prefix(o, o->output_prefix_data);
2926                line_prefix = msgbuf->buf;
2927        }
2928        strbuf_init(msg, PATH_MAX * 2 + 300);
2929        switch (p->status) {
2930        case DIFF_STATUS_COPIED:
2931                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2932                            line_prefix, set, similarity_index(p));
2933                strbuf_addf(msg, "%s\n%s%scopy from ",
2934                            reset,  line_prefix, set);
2935                quote_c_style(name, msg, NULL, 0);
2936                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2937                quote_c_style(other, msg, NULL, 0);
2938                strbuf_addf(msg, "%s\n", reset);
2939                break;
2940        case DIFF_STATUS_RENAMED:
2941                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2942                            line_prefix, set, similarity_index(p));
2943                strbuf_addf(msg, "%s\n%s%srename from ",
2944                            reset, line_prefix, set);
2945                quote_c_style(name, msg, NULL, 0);
2946                strbuf_addf(msg, "%s\n%s%srename to ",
2947                            reset, line_prefix, set);
2948                quote_c_style(other, msg, NULL, 0);
2949                strbuf_addf(msg, "%s\n", reset);
2950                break;
2951        case DIFF_STATUS_MODIFIED:
2952                if (p->score) {
2953                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2954                                    line_prefix,
2955                                    set, similarity_index(p), reset);
2956                        break;
2957                }
2958                /* fallthru */
2959        default:
2960                *must_show_header = 0;
2961        }
2962        if (one && two && hashcmp(one->sha1, two->sha1)) {
2963                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2964
2965                if (DIFF_OPT_TST(o, BINARY)) {
2966                        mmfile_t mf;
2967                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2968                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2969                                abbrev = 40;
2970                }
2971                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2972                            find_unique_abbrev(one->sha1, abbrev));
2973                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2974                if (one->mode == two->mode)
2975                        strbuf_addf(msg, " %06o", one->mode);
2976                strbuf_addf(msg, "%s\n", reset);
2977        }
2978}
2979
2980static void run_diff_cmd(const char *pgm,
2981                         const char *name,
2982                         const char *other,
2983                         const char *attr_path,
2984                         struct diff_filespec *one,
2985                         struct diff_filespec *two,
2986                         struct strbuf *msg,
2987                         struct diff_options *o,
2988                         struct diff_filepair *p)
2989{
2990        const char *xfrm_msg = NULL;
2991        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2992        int must_show_header = 0;
2993
2994
2995        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
2996                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2997                if (drv && drv->external)
2998                        pgm = drv->external;
2999        }
3000
3001        if (msg) {
3002                /*
3003                 * don't use colors when the header is intended for an
3004                 * external diff driver
3005                 */
3006                fill_metainfo(msg, name, other, one, two, o, p,
3007                              &must_show_header,
3008                              want_color(o->use_color) && !pgm);
3009                xfrm_msg = msg->len ? msg->buf : NULL;
3010        }
3011
3012        if (pgm) {
3013                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3014                                  complete_rewrite);
3015                return;
3016        }
3017        if (one && two)
3018                builtin_diff(name, other ? other : name,
3019                             one, two, xfrm_msg, must_show_header,
3020                             o, complete_rewrite);
3021        else
3022                fprintf(o->file, "* Unmerged path %s\n", name);
3023}
3024
3025static void diff_fill_sha1_info(struct diff_filespec *one)
3026{
3027        if (DIFF_FILE_VALID(one)) {
3028                if (!one->sha1_valid) {
3029                        struct stat st;
3030                        if (one->is_stdin) {
3031                                hashcpy(one->sha1, null_sha1);
3032                                return;
3033                        }
3034                        if (lstat(one->path, &st) < 0)
3035                                die_errno("stat '%s'", one->path);
3036                        if (index_path(one->sha1, one->path, &st, 0))
3037                                die("cannot hash %s", one->path);
3038                }
3039        }
3040        else
3041                hashclr(one->sha1);
3042}
3043
3044static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3045{
3046        /* Strip the prefix but do not molest /dev/null and absolute paths */
3047        if (*namep && **namep != '/') {
3048                *namep += prefix_length;
3049                if (**namep == '/')
3050                        ++*namep;
3051        }
3052        if (*otherp && **otherp != '/') {
3053                *otherp += prefix_length;
3054                if (**otherp == '/')
3055                        ++*otherp;
3056        }
3057}
3058
3059static void run_diff(struct diff_filepair *p, struct diff_options *o)
3060{
3061        const char *pgm = external_diff();
3062        struct strbuf msg;
3063        struct diff_filespec *one = p->one;
3064        struct diff_filespec *two = p->two;
3065        const char *name;
3066        const char *other;
3067        const char *attr_path;
3068
3069        name  = p->one->path;
3070        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3071        attr_path = name;
3072        if (o->prefix_length)
3073                strip_prefix(o->prefix_length, &name, &other);
3074
3075        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3076                pgm = NULL;
3077
3078        if (DIFF_PAIR_UNMERGED(p)) {
3079                run_diff_cmd(pgm, name, NULL, attr_path,
3080                             NULL, NULL, NULL, o, p);
3081                return;
3082        }
3083
3084        diff_fill_sha1_info(one);
3085        diff_fill_sha1_info(two);
3086
3087        if (!pgm &&
3088            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3089            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3090                /*
3091                 * a filepair that changes between file and symlink
3092                 * needs to be split into deletion and creation.
3093                 */
3094                struct diff_filespec *null = alloc_filespec(two->path);
3095                run_diff_cmd(NULL, name, other, attr_path,
3096                             one, null, &msg, o, p);
3097                free(null);
3098                strbuf_release(&msg);
3099
3100                null = alloc_filespec(one->path);
3101                run_diff_cmd(NULL, name, other, attr_path,
3102                             null, two, &msg, o, p);
3103                free(null);
3104        }
3105        else
3106                run_diff_cmd(pgm, name, other, attr_path,
3107                             one, two, &msg, o, p);
3108
3109        strbuf_release(&msg);
3110}
3111
3112static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3113                         struct diffstat_t *diffstat)
3114{
3115        const char *name;
3116        const char *other;
3117        int complete_rewrite = 0;
3118
3119        if (DIFF_PAIR_UNMERGED(p)) {
3120                /* unmerged */
3121                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
3122                return;
3123        }
3124
3125        name = p->one->path;
3126        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3127
3128        if (o->prefix_length)
3129                strip_prefix(o->prefix_length, &name, &other);
3130
3131        diff_fill_sha1_info(p->one);
3132        diff_fill_sha1_info(p->two);
3133
3134        if (p->status == DIFF_STATUS_MODIFIED && p->score)
3135                complete_rewrite = 1;
3136        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
3137}
3138
3139static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3140{
3141        const char *name;
3142        const char *other;
3143        const char *attr_path;
3144
3145        if (DIFF_PAIR_UNMERGED(p)) {
3146                /* unmerged */
3147                return;
3148        }
3149
3150        name = p->one->path;
3151        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3152        attr_path = other ? other : name;
3153
3154        if (o->prefix_length)
3155                strip_prefix(o->prefix_length, &name, &other);
3156
3157        diff_fill_sha1_info(p->one);
3158        diff_fill_sha1_info(p->two);
3159
3160        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3161}
3162
3163void diff_setup(struct diff_options *options)
3164{
3165        memcpy(options, &default_diff_options, sizeof(*options));
3166
3167        options->file = stdout;
3168
3169        options->line_termination = '\n';
3170        options->break_opt = -1;
3171        options->rename_limit = -1;
3172        options->dirstat_permille = diff_dirstat_permille_default;
3173        options->context = 3;
3174        DIFF_OPT_SET(options, RENAME_EMPTY);
3175
3176        options->change = diff_change;
3177        options->add_remove = diff_addremove;
3178        options->use_color = diff_use_color_default;
3179        options->detect_rename = diff_detect_rename_default;
3180
3181        if (diff_no_prefix) {
3182                options->a_prefix = options->b_prefix = "";
3183        } else if (!diff_mnemonic_prefix) {
3184                options->a_prefix = "a/";
3185                options->b_prefix = "b/";
3186        }
3187}
3188
3189void diff_setup_done(struct diff_options *options)
3190{
3191        int count = 0;
3192
3193        if (options->output_format & DIFF_FORMAT_NAME)
3194                count++;
3195        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3196                count++;
3197        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3198                count++;
3199        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3200                count++;
3201        if (count > 1)
3202                die("--name-only, --name-status, --check and -s are mutually exclusive");
3203
3204        /*
3205         * Most of the time we can say "there are changes"
3206         * only by checking if there are changed paths, but
3207         * --ignore-whitespace* options force us to look
3208         * inside contents.
3209         */
3210
3211        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3212            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3213            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3214                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3215        else
3216                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3217
3218        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3219                options->detect_rename = DIFF_DETECT_COPY;
3220
3221        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3222                options->prefix = NULL;
3223        if (options->prefix)
3224                options->prefix_length = strlen(options->prefix);
3225        else
3226                options->prefix_length = 0;
3227
3228        if (options->output_format & (DIFF_FORMAT_NAME |
3229                                      DIFF_FORMAT_NAME_STATUS |
3230                                      DIFF_FORMAT_CHECKDIFF |
3231                                      DIFF_FORMAT_NO_OUTPUT))
3232                options->output_format &= ~(DIFF_FORMAT_RAW |
3233                                            DIFF_FORMAT_NUMSTAT |
3234                                            DIFF_FORMAT_DIFFSTAT |
3235                                            DIFF_FORMAT_SHORTSTAT |
3236                                            DIFF_FORMAT_DIRSTAT |
3237                                            DIFF_FORMAT_SUMMARY |
3238                                            DIFF_FORMAT_PATCH);
3239
3240        /*
3241         * These cases always need recursive; we do not drop caller-supplied
3242         * recursive bits for other formats here.
3243         */
3244        if (options->output_format & (DIFF_FORMAT_PATCH |
3245                                      DIFF_FORMAT_NUMSTAT |
3246                                      DIFF_FORMAT_DIFFSTAT |
3247                                      DIFF_FORMAT_SHORTSTAT |
3248                                      DIFF_FORMAT_DIRSTAT |
3249                                      DIFF_FORMAT_SUMMARY |
3250                                      DIFF_FORMAT_CHECKDIFF))
3251                DIFF_OPT_SET(options, RECURSIVE);
3252        /*
3253         * Also pickaxe would not work very well if you do not say recursive
3254         */
3255        if (options->pickaxe)
3256                DIFF_OPT_SET(options, RECURSIVE);
3257        /*
3258         * When patches are generated, submodules diffed against the work tree
3259         * must be checked for dirtiness too so it can be shown in the output
3260         */
3261        if (options->output_format & DIFF_FORMAT_PATCH)
3262                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3263
3264        if (options->detect_rename && options->rename_limit < 0)
3265                options->rename_limit = diff_rename_limit_default;
3266        if (options->setup & DIFF_SETUP_USE_CACHE) {
3267                if (!active_cache)
3268                        /* read-cache does not die even when it fails
3269                         * so it is safe for us to do this here.  Also
3270                         * it does not smudge active_cache or active_nr
3271                         * when it fails, so we do not have to worry about
3272                         * cleaning it up ourselves either.
3273                         */
3274                        read_cache();
3275        }
3276        if (options->abbrev <= 0 || 40 < options->abbrev)
3277                options->abbrev = 40; /* full */
3278
3279        /*
3280         * It does not make sense to show the first hit we happened
3281         * to have found.  It does not make sense not to return with
3282         * exit code in such a case either.
3283         */
3284        if (DIFF_OPT_TST(options, QUICK)) {
3285                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3286                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3287        }
3288}
3289
3290static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3291{
3292        char c, *eq;
3293        int len;
3294
3295        if (*arg != '-')
3296                return 0;
3297        c = *++arg;
3298        if (!c)
3299                return 0;
3300        if (c == arg_short) {
3301                c = *++arg;
3302                if (!c)
3303                        return 1;
3304                if (val && isdigit(c)) {
3305                        char *end;
3306                        int n = strtoul(arg, &end, 10);
3307                        if (*end)
3308                                return 0;
3309                        *val = n;
3310                        return 1;
3311                }
3312                return 0;
3313        }
3314        if (c != '-')
3315                return 0;
3316        arg++;
3317        eq = strchr(arg, '=');
3318        if (eq)
3319                len = eq - arg;
3320        else
3321                len = strlen(arg);
3322        if (!len || strncmp(arg, arg_long, len))
3323                return 0;
3324        if (eq) {
3325                int n;
3326                char *end;
3327                if (!isdigit(*++eq))
3328                        return 0;
3329                n = strtoul(eq, &end, 10);
3330                if (*end)
3331                        return 0;
3332                *val = n;
3333        }
3334        return 1;
3335}
3336
3337static int diff_scoreopt_parse(const char *opt);
3338
3339static inline int short_opt(char opt, const char **argv,
3340                            const char **optarg)
3341{
3342        const char *arg = argv[0];
3343        if (arg[0] != '-' || arg[1] != opt)
3344                return 0;
3345        if (arg[2] != '\0') {
3346                *optarg = arg + 2;
3347                return 1;
3348        }
3349        if (!argv[1])
3350                die("Option '%c' requires a value", opt);
3351        *optarg = argv[1];
3352        return 2;
3353}
3354
3355int parse_long_opt(const char *opt, const char **argv,
3356                   const char **optarg)
3357{
3358        const char *arg = argv[0];
3359        if (arg[0] != '-' || arg[1] != '-')
3360                return 0;
3361        arg += strlen("--");
3362        if (prefixcmp(arg, opt))
3363                return 0;
3364        arg += strlen(opt);
3365        if (*arg == '=') { /* sticked form: --option=value */
3366                *optarg = arg + 1;
3367                return 1;
3368        }
3369        if (*arg != '\0')
3370                return 0;
3371        /* separate form: --option value */
3372        if (!argv[1])
3373                die("Option '--%s' requires a value", opt);
3374        *optarg = argv[1];
3375        return 2;
3376}
3377
3378static int stat_opt(struct diff_options *options, const char **av)
3379{
3380        const char *arg = av[0];
3381        char *end;
3382        int width = options->stat_width;
3383        int name_width = options->stat_name_width;
3384        int graph_width = options->stat_graph_width;
3385        int count = options->stat_count;
3386        int argcount = 1;
3387
3388        arg += strlen("--stat");
3389        end = (char *)arg;
3390
3391        switch (*arg) {
3392        case '-':
3393                if (!prefixcmp(arg, "-width")) {
3394                        arg += strlen("-width");
3395                        if (*arg == '=')
3396                                width = strtoul(arg + 1, &end, 10);
3397                        else if (!*arg && !av[1])
3398                                die("Option '--stat-width' requires a value");
3399                        else if (!*arg) {
3400                                width = strtoul(av[1], &end, 10);
3401                                argcount = 2;
3402                        }
3403                } else if (!prefixcmp(arg, "-name-width")) {
3404                        arg += strlen("-name-width");
3405                        if (*arg == '=')
3406                                name_width = strtoul(arg + 1, &end, 10);
3407                        else if (!*arg && !av[1])
3408                                die("Option '--stat-name-width' requires a value");
3409                        else if (!*arg) {
3410                                name_width = strtoul(av[1], &end, 10);
3411                                argcount = 2;
3412                        }
3413                } else if (!prefixcmp(arg, "-graph-width")) {
3414                        arg += strlen("-graph-width");
3415                        if (*arg == '=')
3416                                graph_width = strtoul(arg + 1, &end, 10);
3417                        else if (!*arg && !av[1])
3418                                die("Option '--stat-graph-width' requires a value");
3419                        else if (!*arg) {
3420                                graph_width = strtoul(av[1], &end, 10);
3421                                argcount = 2;
3422                        }
3423                } else if (!prefixcmp(arg, "-count")) {
3424                        arg += strlen("-count");
3425                        if (*arg == '=')
3426                                count = strtoul(arg + 1, &end, 10);
3427                        else if (!*arg && !av[1])
3428                                die("Option '--stat-count' requires a value");
3429                        else if (!*arg) {
3430                                count = strtoul(av[1], &end, 10);
3431                                argcount = 2;
3432                        }
3433                }
3434                break;
3435        case '=':
3436                width = strtoul(arg+1, &end, 10);
3437                if (*end == ',')
3438                        name_width = strtoul(end+1, &end, 10);
3439                if (*end == ',')
3440                        count = strtoul(end+1, &end, 10);
3441        }
3442
3443        /* Important! This checks all the error cases! */
3444        if (*end)
3445                return 0;
3446        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3447        options->stat_name_width = name_width;
3448        options->stat_graph_width = graph_width;
3449        options->stat_width = width;
3450        options->stat_count = count;
3451        return argcount;
3452}
3453
3454static int parse_dirstat_opt(struct diff_options *options, const char *params)
3455{
3456        struct strbuf errmsg = STRBUF_INIT;
3457        if (parse_dirstat_params(options, params, &errmsg))
3458                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3459                    errmsg.buf);
3460        strbuf_release(&errmsg);
3461        /*
3462         * The caller knows a dirstat-related option is given from the command
3463         * line; allow it to say "return this_function();"
3464         */
3465        options->output_format |= DIFF_FORMAT_DIRSTAT;
3466        return 1;
3467}
3468
3469int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3470{
3471        const char *arg = av[0];
3472        const char *optarg;
3473        int argcount;
3474
3475        /* Output format options */
3476        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3477                options->output_format |= DIFF_FORMAT_PATCH;
3478        else if (opt_arg(arg, 'U', "unified", &options->context))
3479                options->output_format |= DIFF_FORMAT_PATCH;
3480        else if (!strcmp(arg, "--raw"))
3481                options->output_format |= DIFF_FORMAT_RAW;
3482        else if (!strcmp(arg, "--patch-with-raw"))
3483                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3484        else if (!strcmp(arg, "--numstat"))
3485                options->output_format |= DIFF_FORMAT_NUMSTAT;
3486        else if (!strcmp(arg, "--shortstat"))
3487                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3488        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3489                return parse_dirstat_opt(options, "");
3490        else if (!prefixcmp(arg, "-X"))
3491                return parse_dirstat_opt(options, arg + 2);
3492        else if (!prefixcmp(arg, "--dirstat="))
3493                return parse_dirstat_opt(options, arg + 10);
3494        else if (!strcmp(arg, "--cumulative"))
3495                return parse_dirstat_opt(options, "cumulative");
3496        else if (!strcmp(arg, "--dirstat-by-file"))
3497                return parse_dirstat_opt(options, "files");
3498        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3499                parse_dirstat_opt(options, "files");
3500                return parse_dirstat_opt(options, arg + 18);
3501        }
3502        else if (!strcmp(arg, "--check"))
3503                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3504        else if (!strcmp(arg, "--summary"))
3505                options->output_format |= DIFF_FORMAT_SUMMARY;
3506        else if (!strcmp(arg, "--patch-with-stat"))
3507                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3508        else if (!strcmp(arg, "--name-only"))
3509                options->output_format |= DIFF_FORMAT_NAME;
3510        else if (!strcmp(arg, "--name-status"))
3511                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3512        else if (!strcmp(arg, "-s"))
3513                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3514        else if (!prefixcmp(arg, "--stat"))
3515                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3516                return stat_opt(options, av);
3517
3518        /* renames options */
3519        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3520                 !strcmp(arg, "--break-rewrites")) {
3521                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3522                        return error("invalid argument to -B: %s", arg+2);
3523        }
3524        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3525                 !strcmp(arg, "--find-renames")) {
3526                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3527                        return error("invalid argument to -M: %s", arg+2);
3528                options->detect_rename = DIFF_DETECT_RENAME;
3529        }
3530        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3531                options->irreversible_delete = 1;
3532        }
3533        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3534                 !strcmp(arg, "--find-copies")) {
3535                if (options->detect_rename == DIFF_DETECT_COPY)
3536                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3537                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3538                        return error("invalid argument to -C: %s", arg+2);
3539                options->detect_rename = DIFF_DETECT_COPY;
3540        }
3541        else if (!strcmp(arg, "--no-renames"))
3542                options->detect_rename = 0;
3543        else if (!strcmp(arg, "--rename-empty"))
3544                DIFF_OPT_SET(options, RENAME_EMPTY);
3545        else if (!strcmp(arg, "--no-rename-empty"))
3546                DIFF_OPT_CLR(options, RENAME_EMPTY);
3547        else if (!strcmp(arg, "--relative"))
3548                DIFF_OPT_SET(options, RELATIVE_NAME);
3549        else if (!prefixcmp(arg, "--relative=")) {
3550                DIFF_OPT_SET(options, RELATIVE_NAME);
3551                options->prefix = arg + 11;
3552        }
3553
3554        /* xdiff options */
3555        else if (!strcmp(arg, "--minimal"))
3556                DIFF_XDL_SET(options, NEED_MINIMAL);
3557        else if (!strcmp(arg, "--no-minimal"))
3558                DIFF_XDL_CLR(options, NEED_MINIMAL);
3559        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3560                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3561        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3562                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3563        else if (!strcmp(arg, "--ignore-space-at-eol"))
3564                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3565        else if (!strcmp(arg, "--patience"))
3566                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3567        else if (!strcmp(arg, "--histogram"))
3568                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3569
3570        /* flags options */
3571        else if (!strcmp(arg, "--binary")) {
3572                options->output_format |= DIFF_FORMAT_PATCH;
3573                DIFF_OPT_SET(options, BINARY);
3574        }
3575        else if (!strcmp(arg, "--full-index"))
3576                DIFF_OPT_SET(options, FULL_INDEX);
3577        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3578                DIFF_OPT_SET(options, TEXT);
3579        else if (!strcmp(arg, "-R"))
3580                DIFF_OPT_SET(options, REVERSE_DIFF);
3581        else if (!strcmp(arg, "--find-copies-harder"))
3582                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3583        else if (!strcmp(arg, "--follow"))
3584                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3585        else if (!strcmp(arg, "--color"))
3586                options->use_color = 1;
3587        else if (!prefixcmp(arg, "--color=")) {
3588                int value = git_config_colorbool(NULL, arg+8);
3589                if (value < 0)
3590                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3591                options->use_color = value;
3592        }
3593        else if (!strcmp(arg, "--no-color"))
3594                options->use_color = 0;
3595        else if (!strcmp(arg, "--color-words")) {
3596                options->use_color = 1;
3597                options->word_diff = DIFF_WORDS_COLOR;
3598        }
3599        else if (!prefixcmp(arg, "--color-words=")) {
3600                options->use_color = 1;
3601                options->word_diff = DIFF_WORDS_COLOR;
3602                options->word_regex = arg + 14;
3603        }
3604        else if (!strcmp(arg, "--word-diff")) {
3605                if (options->word_diff == DIFF_WORDS_NONE)
3606                        options->word_diff = DIFF_WORDS_PLAIN;
3607        }
3608        else if (!prefixcmp(arg, "--word-diff=")) {
3609                const char *type = arg + 12;
3610                if (!strcmp(type, "plain"))
3611                        options->word_diff = DIFF_WORDS_PLAIN;
3612                else if (!strcmp(type, "color")) {
3613                        options->use_color = 1;
3614                        options->word_diff = DIFF_WORDS_COLOR;
3615                }
3616                else if (!strcmp(type, "porcelain"))
3617                        options->word_diff = DIFF_WORDS_PORCELAIN;
3618                else if (!strcmp(type, "none"))
3619                        options->word_diff = DIFF_WORDS_NONE;
3620                else
3621                        die("bad --word-diff argument: %s", type);
3622        }
3623        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3624                if (options->word_diff == DIFF_WORDS_NONE)
3625                        options->word_diff = DIFF_WORDS_PLAIN;
3626                options->word_regex = optarg;
3627                return argcount;
3628        }
3629        else if (!strcmp(arg, "--exit-code"))
3630                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3631        else if (!strcmp(arg, "--quiet"))
3632                DIFF_OPT_SET(options, QUICK);
3633        else if (!strcmp(arg, "--ext-diff"))
3634                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3635        else if (!strcmp(arg, "--no-ext-diff"))
3636                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3637        else if (!strcmp(arg, "--textconv"))
3638                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3639        else if (!strcmp(arg, "--no-textconv"))
3640                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3641        else if (!strcmp(arg, "--ignore-submodules")) {
3642                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3643                handle_ignore_submodules_arg(options, "all");
3644        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3645                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3646                handle_ignore_submodules_arg(options, arg + 20);
3647        } else if (!strcmp(arg, "--submodule"))
3648                DIFF_OPT_SET(options, SUBMODULE_LOG);
3649        else if (!prefixcmp(arg, "--submodule=")) {
3650                if (!strcmp(arg + 12, "log"))
3651                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3652        }
3653
3654        /* misc options */
3655        else if (!strcmp(arg, "-z"))
3656                options->line_termination = 0;
3657        else if ((argcount = short_opt('l', av, &optarg))) {
3658                options->rename_limit = strtoul(optarg, NULL, 10);
3659                return argcount;
3660        }
3661        else if ((argcount = short_opt('S', av, &optarg))) {
3662                options->pickaxe = optarg;
3663                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3664                return argcount;
3665        } else if ((argcount = short_opt('G', av, &optarg))) {
3666                options->pickaxe = optarg;
3667                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3668                return argcount;
3669        }
3670        else if (!strcmp(arg, "--pickaxe-all"))
3671                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3672        else if (!strcmp(arg, "--pickaxe-regex"))
3673                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3674        else if ((argcount = short_opt('O', av, &optarg))) {
3675                options->orderfile = optarg;
3676                return argcount;
3677        }
3678        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3679                options->filter = optarg;
3680                return argcount;
3681        }
3682        else if (!strcmp(arg, "--abbrev"))
3683                options->abbrev = DEFAULT_ABBREV;
3684        else if (!prefixcmp(arg, "--abbrev=")) {
3685                options->abbrev = strtoul(arg + 9, NULL, 10);
3686                if (options->abbrev < MINIMUM_ABBREV)
3687                        options->abbrev = MINIMUM_ABBREV;
3688                else if (40 < options->abbrev)
3689                        options->abbrev = 40;
3690        }
3691        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3692                options->a_prefix = optarg;
3693                return argcount;
3694        }
3695        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3696                options->b_prefix = optarg;
3697                return argcount;
3698        }
3699        else if (!strcmp(arg, "--no-prefix"))
3700                options->a_prefix = options->b_prefix = "";
3701        else if (opt_arg(arg, '\0', "inter-hunk-context",
3702                         &options->interhunkcontext))
3703                ;
3704        else if (!strcmp(arg, "-W"))
3705                DIFF_OPT_SET(options, FUNCCONTEXT);
3706        else if (!strcmp(arg, "--function-context"))
3707                DIFF_OPT_SET(options, FUNCCONTEXT);
3708        else if (!strcmp(arg, "--no-function-context"))
3709                DIFF_OPT_CLR(options, FUNCCONTEXT);
3710        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3711                options->file = fopen(optarg, "w");
3712                if (!options->file)
3713                        die_errno("Could not open '%s'", optarg);
3714                options->close_file = 1;
3715                return argcount;
3716        } else
3717                return 0;
3718        return 1;
3719}
3720
3721int parse_rename_score(const char **cp_p)
3722{
3723        unsigned long num, scale;
3724        int ch, dot;
3725        const char *cp = *cp_p;
3726
3727        num = 0;
3728        scale = 1;
3729        dot = 0;
3730        for (;;) {
3731                ch = *cp;
3732                if ( !dot && ch == '.' ) {
3733                        scale = 1;
3734                        dot = 1;
3735                } else if ( ch == '%' ) {
3736                        scale = dot ? scale*100 : 100;
3737                        cp++;   /* % is always at the end */
3738                        break;
3739                } else if ( ch >= '0' && ch <= '9' ) {
3740                        if ( scale < 100000 ) {
3741                                scale *= 10;
3742                                num = (num*10) + (ch-'0');
3743                        }
3744                } else {
3745                        break;
3746                }
3747                cp++;
3748        }
3749        *cp_p = cp;
3750
3751        /* user says num divided by scale and we say internally that
3752         * is MAX_SCORE * num / scale.
3753         */
3754        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3755}
3756
3757static int diff_scoreopt_parse(const char *opt)
3758{
3759        int opt1, opt2, cmd;
3760
3761        if (*opt++ != '-')
3762                return -1;
3763        cmd = *opt++;
3764        if (cmd == '-') {
3765                /* convert the long-form arguments into short-form versions */
3766                if (!prefixcmp(opt, "break-rewrites")) {
3767                        opt += strlen("break-rewrites");
3768                        if (*opt == 0 || *opt++ == '=')
3769                                cmd = 'B';
3770                } else if (!prefixcmp(opt, "find-copies")) {
3771                        opt += strlen("find-copies");
3772                        if (*opt == 0 || *opt++ == '=')
3773                                cmd = 'C';
3774                } else if (!prefixcmp(opt, "find-renames")) {
3775                        opt += strlen("find-renames");
3776                        if (*opt == 0 || *opt++ == '=')
3777                                cmd = 'M';
3778                }
3779        }
3780        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3781                return -1; /* that is not a -M, -C nor -B option */
3782
3783        opt1 = parse_rename_score(&opt);
3784        if (cmd != 'B')
3785                opt2 = 0;
3786        else {
3787                if (*opt == 0)
3788                        opt2 = 0;
3789                else if (*opt != '/')
3790                        return -1; /* we expect -B80/99 or -B80 */
3791                else {
3792                        opt++;
3793                        opt2 = parse_rename_score(&opt);
3794                }
3795        }
3796        if (*opt != 0)
3797                return -1;
3798        return opt1 | (opt2 << 16);
3799}
3800
3801struct diff_queue_struct diff_queued_diff;
3802
3803void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3804{
3805        if (queue->alloc <= queue->nr) {
3806                queue->alloc = alloc_nr(queue->alloc);
3807                queue->queue = xrealloc(queue->queue,
3808                                        sizeof(dp) * queue->alloc);
3809        }
3810        queue->queue[queue->nr++] = dp;
3811}
3812
3813struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3814                                 struct diff_filespec *one,
3815                                 struct diff_filespec *two)
3816{
3817        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3818        dp->one = one;
3819        dp->two = two;
3820        if (queue)
3821                diff_q(queue, dp);
3822        return dp;
3823}
3824
3825void diff_free_filepair(struct diff_filepair *p)
3826{
3827        free_filespec(p->one);
3828        free_filespec(p->two);
3829        free(p);
3830}
3831
3832/* This is different from find_unique_abbrev() in that
3833 * it stuffs the result with dots for alignment.
3834 */
3835const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3836{
3837        int abblen;
3838        const char *abbrev;
3839        if (len == 40)
3840                return sha1_to_hex(sha1);
3841
3842        abbrev = find_unique_abbrev(sha1, len);
3843        abblen = strlen(abbrev);
3844        if (abblen < 37) {
3845                static char hex[41];
3846                if (len < abblen && abblen <= len + 2)
3847                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3848                else
3849                        sprintf(hex, "%s...", abbrev);
3850                return hex;
3851        }
3852        return sha1_to_hex(sha1);
3853}
3854
3855static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3856{
3857        int line_termination = opt->line_termination;
3858        int inter_name_termination = line_termination ? '\t' : '\0';
3859        if (opt->output_prefix) {
3860                struct strbuf *msg = NULL;
3861                msg = opt->output_prefix(opt, opt->output_prefix_data);
3862                fprintf(opt->file, "%s", msg->buf);
3863        }
3864
3865        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3866                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3867                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3868                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3869        }
3870        if (p->score) {
3871                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3872                        inter_name_termination);
3873        } else {
3874                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3875        }
3876
3877        if (p->status == DIFF_STATUS_COPIED ||
3878            p->status == DIFF_STATUS_RENAMED) {
3879                const char *name_a, *name_b;
3880                name_a = p->one->path;
3881                name_b = p->two->path;
3882                strip_prefix(opt->prefix_length, &name_a, &name_b);
3883                write_name_quoted(name_a, opt->file, inter_name_termination);
3884                write_name_quoted(name_b, opt->file, line_termination);
3885        } else {
3886                const char *name_a, *name_b;
3887                name_a = p->one->mode ? p->one->path : p->two->path;
3888                name_b = NULL;
3889                strip_prefix(opt->prefix_length, &name_a, &name_b);
3890                write_name_quoted(name_a, opt->file, line_termination);
3891        }
3892}
3893
3894int diff_unmodified_pair(struct diff_filepair *p)
3895{
3896        /* This function is written stricter than necessary to support
3897         * the currently implemented transformers, but the idea is to
3898         * let transformers to produce diff_filepairs any way they want,
3899         * and filter and clean them up here before producing the output.
3900         */
3901        struct diff_filespec *one = p->one, *two = p->two;
3902
3903        if (DIFF_PAIR_UNMERGED(p))
3904                return 0; /* unmerged is interesting */
3905
3906        /* deletion, addition, mode or type change
3907         * and rename are all interesting.
3908         */
3909        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3910            DIFF_PAIR_MODE_CHANGED(p) ||
3911            strcmp(one->path, two->path))
3912                return 0;
3913
3914        /* both are valid and point at the same path.  that is, we are
3915         * dealing with a change.
3916         */
3917        if (one->sha1_valid && two->sha1_valid &&
3918            !hashcmp(one->sha1, two->sha1) &&
3919            !one->dirty_submodule && !two->dirty_submodule)
3920                return 1; /* no change */
3921        if (!one->sha1_valid && !two->sha1_valid)
3922                return 1; /* both look at the same file on the filesystem. */
3923        return 0;
3924}
3925
3926static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3927{
3928        if (diff_unmodified_pair(p))
3929                return;
3930
3931        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3932            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3933                return; /* no tree diffs in patch format */
3934
3935        run_diff(p, o);
3936}
3937
3938static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3939                            struct diffstat_t *diffstat)
3940{
3941        if (diff_unmodified_pair(p))
3942                return;
3943
3944        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3945            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3946                return; /* no useful stat for tree diffs */
3947
3948        run_diffstat(p, o, diffstat);
3949}
3950
3951static void diff_flush_checkdiff(struct diff_filepair *p,
3952                struct diff_options *o)
3953{
3954        if (diff_unmodified_pair(p))
3955                return;
3956
3957        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3958            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3959                return; /* nothing to check in tree diffs */
3960
3961        run_checkdiff(p, o);
3962}
3963
3964int diff_queue_is_empty(void)
3965{
3966        struct diff_queue_struct *q = &diff_queued_diff;
3967        int i;
3968        for (i = 0; i < q->nr; i++)
3969                if (!diff_unmodified_pair(q->queue[i]))
3970                        return 0;
3971        return 1;
3972}
3973
3974#if DIFF_DEBUG
3975void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3976{
3977        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3978                x, one ? one : "",
3979                s->path,
3980                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3981                s->mode,
3982                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3983        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3984                x, one ? one : "",
3985                s->size, s->xfrm_flags);
3986}
3987
3988void diff_debug_filepair(const struct diff_filepair *p, int i)
3989{
3990        diff_debug_filespec(p->one, i, "one");
3991        diff_debug_filespec(p->two, i, "two");
3992        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3993                p->score, p->status ? p->status : '?',
3994                p->one->rename_used, p->broken_pair);
3995}
3996
3997void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3998{
3999        int i;
4000        if (msg)
4001                fprintf(stderr, "%s\n", msg);
4002        fprintf(stderr, "q->nr = %d\n", q->nr);
4003        for (i = 0; i < q->nr; i++) {
4004                struct diff_filepair *p = q->queue[i];
4005                diff_debug_filepair(p, i);
4006        }
4007}
4008#endif
4009
4010static void diff_resolve_rename_copy(void)
4011{
4012        int i;
4013        struct diff_filepair *p;
4014        struct diff_queue_struct *q = &diff_queued_diff;
4015
4016        diff_debug_queue("resolve-rename-copy", q);
4017
4018        for (i = 0; i < q->nr; i++) {
4019                p = q->queue[i];
4020                p->status = 0; /* undecided */
4021                if (DIFF_PAIR_UNMERGED(p))
4022                        p->status = DIFF_STATUS_UNMERGED;
4023                else if (!DIFF_FILE_VALID(p->one))
4024                        p->status = DIFF_STATUS_ADDED;
4025                else if (!DIFF_FILE_VALID(p->two))
4026                        p->status = DIFF_STATUS_DELETED;
4027                else if (DIFF_PAIR_TYPE_CHANGED(p))
4028                        p->status = DIFF_STATUS_TYPE_CHANGED;
4029
4030                /* from this point on, we are dealing with a pair
4031                 * whose both sides are valid and of the same type, i.e.
4032                 * either in-place edit or rename/copy edit.
4033                 */
4034                else if (DIFF_PAIR_RENAME(p)) {
4035                        /*
4036                         * A rename might have re-connected a broken
4037                         * pair up, causing the pathnames to be the
4038                         * same again. If so, that's not a rename at
4039                         * all, just a modification..
4040                         *
4041                         * Otherwise, see if this source was used for
4042                         * multiple renames, in which case we decrement
4043                         * the count, and call it a copy.
4044                         */
4045                        if (!strcmp(p->one->path, p->two->path))
4046                                p->status = DIFF_STATUS_MODIFIED;
4047                        else if (--p->one->rename_used > 0)
4048                                p->status = DIFF_STATUS_COPIED;
4049                        else
4050                                p->status = DIFF_STATUS_RENAMED;
4051                }
4052                else if (hashcmp(p->one->sha1, p->two->sha1) ||
4053                         p->one->mode != p->two->mode ||
4054                         p->one->dirty_submodule ||
4055                         p->two->dirty_submodule ||
4056                         is_null_sha1(p->one->sha1))
4057                        p->status = DIFF_STATUS_MODIFIED;
4058                else {
4059                        /* This is a "no-change" entry and should not
4060                         * happen anymore, but prepare for broken callers.
4061                         */
4062                        error("feeding unmodified %s to diffcore",
4063                              p->one->path);
4064                        p->status = DIFF_STATUS_UNKNOWN;
4065                }
4066        }
4067        diff_debug_queue("resolve-rename-copy done", q);
4068}
4069
4070static int check_pair_status(struct diff_filepair *p)
4071{
4072        switch (p->status) {
4073        case DIFF_STATUS_UNKNOWN:
4074                return 0;
4075        case 0:
4076                die("internal error in diff-resolve-rename-copy");
4077        default:
4078                return 1;
4079        }
4080}
4081
4082static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4083{
4084        int fmt = opt->output_format;
4085
4086        if (fmt & DIFF_FORMAT_CHECKDIFF)
4087                diff_flush_checkdiff(p, opt);
4088        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4089                diff_flush_raw(p, opt);
4090        else if (fmt & DIFF_FORMAT_NAME) {
4091                const char *name_a, *name_b;
4092                name_a = p->two->path;
4093                name_b = NULL;
4094                strip_prefix(opt->prefix_length, &name_a, &name_b);
4095                write_name_quoted(name_a, opt->file, opt->line_termination);
4096        }
4097}
4098
4099static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4100{
4101        if (fs->mode)
4102                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4103        else
4104                fprintf(file, " %s ", newdelete);
4105        write_name_quoted(fs->path, file, '\n');
4106}
4107
4108
4109static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4110                const char *line_prefix)
4111{
4112        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4113                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4114                        p->two->mode, show_name ? ' ' : '\n');
4115                if (show_name) {
4116                        write_name_quoted(p->two->path, file, '\n');
4117                }
4118        }
4119}
4120
4121static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4122                        const char *line_prefix)
4123{
4124        char *names = pprint_rename(p->one->path, p->two->path);
4125
4126        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4127        free(names);
4128        show_mode_change(file, p, 0, line_prefix);
4129}
4130
4131static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4132{
4133        FILE *file = opt->file;
4134        char *line_prefix = "";
4135
4136        if (opt->output_prefix) {
4137                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
4138                line_prefix = buf->buf;
4139        }
4140
4141        switch(p->status) {
4142        case DIFF_STATUS_DELETED:
4143                fputs(line_prefix, file);
4144                show_file_mode_name(file, "delete", p->one);
4145                break;
4146        case DIFF_STATUS_ADDED:
4147                fputs(line_prefix, file);
4148                show_file_mode_name(file, "create", p->two);
4149                break;
4150        case DIFF_STATUS_COPIED:
4151                fputs(line_prefix, file);
4152                show_rename_copy(file, "copy", p, line_prefix);
4153                break;
4154        case DIFF_STATUS_RENAMED:
4155                fputs(line_prefix, file);
4156                show_rename_copy(file, "rename", p, line_prefix);
4157                break;
4158        default:
4159                if (p->score) {
4160                        fprintf(file, "%s rewrite ", line_prefix);
4161                        write_name_quoted(p->two->path, file, ' ');
4162                        fprintf(file, "(%d%%)\n", similarity_index(p));
4163                }
4164                show_mode_change(file, p, !p->score, line_prefix);
4165                break;
4166        }
4167}
4168
4169struct patch_id_t {
4170        git_SHA_CTX *ctx;
4171        int patchlen;
4172};
4173
4174static int remove_space(char *line, int len)
4175{
4176        int i;
4177        char *dst = line;
4178        unsigned char c;
4179
4180        for (i = 0; i < len; i++)
4181                if (!isspace((c = line[i])))
4182                        *dst++ = c;
4183
4184        return dst - line;
4185}
4186
4187static void patch_id_consume(void *priv, char *line, unsigned long len)
4188{
4189        struct patch_id_t *data = priv;
4190        int new_len;
4191
4192        /* Ignore line numbers when computing the SHA1 of the patch */
4193        if (!prefixcmp(line, "@@ -"))
4194                return;
4195
4196        new_len = remove_space(line, len);
4197
4198        git_SHA1_Update(data->ctx, line, new_len);
4199        data->patchlen += new_len;
4200}
4201
4202/* returns 0 upon success, and writes result into sha1 */
4203static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4204{
4205        struct diff_queue_struct *q = &diff_queued_diff;
4206        int i;
4207        git_SHA_CTX ctx;
4208        struct patch_id_t data;
4209        char buffer[PATH_MAX * 4 + 20];
4210
4211        git_SHA1_Init(&ctx);
4212        memset(&data, 0, sizeof(struct patch_id_t));
4213        data.ctx = &ctx;
4214
4215        for (i = 0; i < q->nr; i++) {
4216                xpparam_t xpp;
4217                xdemitconf_t xecfg;
4218                mmfile_t mf1, mf2;
4219                struct diff_filepair *p = q->queue[i];
4220                int len1, len2;
4221
4222                memset(&xpp, 0, sizeof(xpp));
4223                memset(&xecfg, 0, sizeof(xecfg));
4224                if (p->status == 0)
4225                        return error("internal diff status error");
4226                if (p->status == DIFF_STATUS_UNKNOWN)
4227                        continue;
4228                if (diff_unmodified_pair(p))
4229                        continue;
4230                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4231                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4232                        continue;
4233                if (DIFF_PAIR_UNMERGED(p))
4234                        continue;
4235
4236                diff_fill_sha1_info(p->one);
4237                diff_fill_sha1_info(p->two);
4238                if (fill_mmfile(&mf1, p->one) < 0 ||
4239                                fill_mmfile(&mf2, p->two) < 0)
4240                        return error("unable to read files to diff");
4241
4242                len1 = remove_space(p->one->path, strlen(p->one->path));
4243                len2 = remove_space(p->two->path, strlen(p->two->path));
4244                if (p->one->mode == 0)
4245                        len1 = snprintf(buffer, sizeof(buffer),
4246                                        "diff--gita/%.*sb/%.*s"
4247                                        "newfilemode%06o"
4248                                        "---/dev/null"
4249                                        "+++b/%.*s",
4250                                        len1, p->one->path,
4251                                        len2, p->two->path,
4252                                        p->two->mode,
4253                                        len2, p->two->path);
4254                else if (p->two->mode == 0)
4255                        len1 = snprintf(buffer, sizeof(buffer),
4256                                        "diff--gita/%.*sb/%.*s"
4257                                        "deletedfilemode%06o"
4258                                        "---a/%.*s"
4259                                        "+++/dev/null",
4260                                        len1, p->one->path,
4261                                        len2, p->two->path,
4262                                        p->one->mode,
4263                                        len1, p->one->path);
4264                else
4265                        len1 = snprintf(buffer, sizeof(buffer),
4266                                        "diff--gita/%.*sb/%.*s"
4267                                        "---a/%.*s"
4268                                        "+++b/%.*s",
4269                                        len1, p->one->path,
4270                                        len2, p->two->path,
4271                                        len1, p->one->path,
4272                                        len2, p->two->path);
4273                git_SHA1_Update(&ctx, buffer, len1);
4274
4275                if (diff_filespec_is_binary(p->one) ||
4276                    diff_filespec_is_binary(p->two)) {
4277                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4278                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4279                        continue;
4280                }
4281
4282                xpp.flags = 0;
4283                xecfg.ctxlen = 3;
4284                xecfg.flags = 0;
4285                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4286                              &xpp, &xecfg);
4287        }
4288
4289        git_SHA1_Final(sha1, &ctx);
4290        return 0;
4291}
4292
4293int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4294{
4295        struct diff_queue_struct *q = &diff_queued_diff;
4296        int i;
4297        int result = diff_get_patch_id(options, sha1);
4298
4299        for (i = 0; i < q->nr; i++)
4300                diff_free_filepair(q->queue[i]);
4301
4302        free(q->queue);
4303        DIFF_QUEUE_CLEAR(q);
4304
4305        return result;
4306}
4307
4308static int is_summary_empty(const struct diff_queue_struct *q)
4309{
4310        int i;
4311
4312        for (i = 0; i < q->nr; i++) {
4313                const struct diff_filepair *p = q->queue[i];
4314
4315                switch (p->status) {
4316                case DIFF_STATUS_DELETED:
4317                case DIFF_STATUS_ADDED:
4318                case DIFF_STATUS_COPIED:
4319                case DIFF_STATUS_RENAMED:
4320                        return 0;
4321                default:
4322                        if (p->score)
4323                                return 0;
4324                        if (p->one->mode && p->two->mode &&
4325                            p->one->mode != p->two->mode)
4326                                return 0;
4327                        break;
4328                }
4329        }
4330        return 1;
4331}
4332
4333static const char rename_limit_warning[] =
4334"inexact rename detection was skipped due to too many files.";
4335
4336static const char degrade_cc_to_c_warning[] =
4337"only found copies from modified paths due to too many files.";
4338
4339static const char rename_limit_advice[] =
4340"you may want to set your %s variable to at least "
4341"%d and retry the command.";
4342
4343void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4344{
4345        if (degraded_cc)
4346                warning(degrade_cc_to_c_warning);
4347        else if (needed)
4348                warning(rename_limit_warning);
4349        else
4350                return;
4351        if (0 < needed && needed < 32767)
4352                warning(rename_limit_advice, varname, needed);
4353}
4354
4355void diff_flush(struct diff_options *options)
4356{
4357        struct diff_queue_struct *q = &diff_queued_diff;
4358        int i, output_format = options->output_format;
4359        int separator = 0;
4360        int dirstat_by_line = 0;
4361
4362        /*
4363         * Order: raw, stat, summary, patch
4364         * or:    name/name-status/checkdiff (other bits clear)
4365         */
4366        if (!q->nr)
4367                goto free_queue;
4368
4369        if (output_format & (DIFF_FORMAT_RAW |
4370                             DIFF_FORMAT_NAME |
4371                             DIFF_FORMAT_NAME_STATUS |
4372                             DIFF_FORMAT_CHECKDIFF)) {
4373                for (i = 0; i < q->nr; i++) {
4374                        struct diff_filepair *p = q->queue[i];
4375                        if (check_pair_status(p))
4376                                flush_one_pair(p, options);
4377                }
4378                separator++;
4379        }
4380
4381        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4382                dirstat_by_line = 1;
4383
4384        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4385            dirstat_by_line) {
4386                struct diffstat_t diffstat;
4387
4388                memset(&diffstat, 0, sizeof(struct diffstat_t));
4389                for (i = 0; i < q->nr; i++) {
4390                        struct diff_filepair *p = q->queue[i];
4391                        if (check_pair_status(p))
4392                                diff_flush_stat(p, options, &diffstat);
4393                }
4394                if (output_format & DIFF_FORMAT_NUMSTAT)
4395                        show_numstat(&diffstat, options);
4396                if (output_format & DIFF_FORMAT_DIFFSTAT)
4397                        show_stats(&diffstat, options);
4398                if (output_format & DIFF_FORMAT_SHORTSTAT)
4399                        show_shortstats(&diffstat, options);
4400                if (output_format & DIFF_FORMAT_DIRSTAT)
4401                        show_dirstat_by_line(&diffstat, options);
4402                free_diffstat_info(&diffstat);
4403                separator++;
4404        }
4405        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4406                show_dirstat(options);
4407
4408        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4409                for (i = 0; i < q->nr; i++) {
4410                        diff_summary(options, q->queue[i]);
4411                }
4412                separator++;
4413        }
4414
4415        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4416            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4417            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4418                /*
4419                 * run diff_flush_patch for the exit status. setting
4420                 * options->file to /dev/null should be safe, becaue we
4421                 * aren't supposed to produce any output anyway.
4422                 */
4423                if (options->close_file)
4424                        fclose(options->file);
4425                options->file = fopen("/dev/null", "w");
4426                if (!options->file)
4427                        die_errno("Could not open /dev/null");
4428                options->close_file = 1;
4429                for (i = 0; i < q->nr; i++) {
4430                        struct diff_filepair *p = q->queue[i];
4431                        if (check_pair_status(p))
4432                                diff_flush_patch(p, options);
4433                        if (options->found_changes)
4434                                break;
4435                }
4436        }
4437
4438        if (output_format & DIFF_FORMAT_PATCH) {
4439                if (separator) {
4440                        if (options->output_prefix) {
4441                                struct strbuf *msg = NULL;
4442                                msg = options->output_prefix(options,
4443                                        options->output_prefix_data);
4444                                fwrite(msg->buf, msg->len, 1, stdout);
4445                        }
4446                        putc(options->line_termination, options->file);
4447                        if (options->stat_sep) {
4448                                /* attach patch instead of inline */
4449                                fputs(options->stat_sep, options->file);
4450                        }
4451                }
4452
4453                for (i = 0; i < q->nr; i++) {
4454                        struct diff_filepair *p = q->queue[i];
4455                        if (check_pair_status(p))
4456                                diff_flush_patch(p, options);
4457                }
4458        }
4459
4460        if (output_format & DIFF_FORMAT_CALLBACK)
4461                options->format_callback(q, options, options->format_callback_data);
4462
4463        for (i = 0; i < q->nr; i++)
4464                diff_free_filepair(q->queue[i]);
4465free_queue:
4466        free(q->queue);
4467        DIFF_QUEUE_CLEAR(q);
4468        if (options->close_file)
4469                fclose(options->file);
4470
4471        /*
4472         * Report the content-level differences with HAS_CHANGES;
4473         * diff_addremove/diff_change does not set the bit when
4474         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4475         */
4476        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4477                if (options->found_changes)
4478                        DIFF_OPT_SET(options, HAS_CHANGES);
4479                else
4480                        DIFF_OPT_CLR(options, HAS_CHANGES);
4481        }
4482}
4483
4484static void diffcore_apply_filter(const char *filter)
4485{
4486        int i;
4487        struct diff_queue_struct *q = &diff_queued_diff;
4488        struct diff_queue_struct outq;
4489        DIFF_QUEUE_CLEAR(&outq);
4490
4491        if (!filter)
4492                return;
4493
4494        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4495                int found;
4496                for (i = found = 0; !found && i < q->nr; i++) {
4497                        struct diff_filepair *p = q->queue[i];
4498                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4499                             ((p->score &&
4500                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4501                              (!p->score &&
4502                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4503                            ((p->status != DIFF_STATUS_MODIFIED) &&
4504                             strchr(filter, p->status)))
4505                                found++;
4506                }
4507                if (found)
4508                        return;
4509
4510                /* otherwise we will clear the whole queue
4511                 * by copying the empty outq at the end of this
4512                 * function, but first clear the current entries
4513                 * in the queue.
4514                 */
4515                for (i = 0; i < q->nr; i++)
4516                        diff_free_filepair(q->queue[i]);
4517        }
4518        else {
4519                /* Only the matching ones */
4520                for (i = 0; i < q->nr; i++) {
4521                        struct diff_filepair *p = q->queue[i];
4522
4523                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4524                             ((p->score &&
4525                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4526                              (!p->score &&
4527                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4528                            ((p->status != DIFF_STATUS_MODIFIED) &&
4529                             strchr(filter, p->status)))
4530                                diff_q(&outq, p);
4531                        else
4532                                diff_free_filepair(p);
4533                }
4534        }
4535        free(q->queue);
4536        *q = outq;
4537}
4538
4539/* Check whether two filespecs with the same mode and size are identical */
4540static int diff_filespec_is_identical(struct diff_filespec *one,
4541                                      struct diff_filespec *two)
4542{
4543        if (S_ISGITLINK(one->mode))
4544                return 0;
4545        if (diff_populate_filespec(one, 0))
4546                return 0;
4547        if (diff_populate_filespec(two, 0))
4548                return 0;
4549        return !memcmp(one->data, two->data, one->size);
4550}
4551
4552static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4553{
4554        int i;
4555        struct diff_queue_struct *q = &diff_queued_diff;
4556        struct diff_queue_struct outq;
4557        DIFF_QUEUE_CLEAR(&outq);
4558
4559        for (i = 0; i < q->nr; i++) {
4560                struct diff_filepair *p = q->queue[i];
4561
4562                /*
4563                 * 1. Entries that come from stat info dirtiness
4564                 *    always have both sides (iow, not create/delete),
4565                 *    one side of the object name is unknown, with
4566                 *    the same mode and size.  Keep the ones that
4567                 *    do not match these criteria.  They have real
4568                 *    differences.
4569                 *
4570                 * 2. At this point, the file is known to be modified,
4571                 *    with the same mode and size, and the object
4572                 *    name of one side is unknown.  Need to inspect
4573                 *    the identical contents.
4574                 */
4575                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4576                    !DIFF_FILE_VALID(p->two) ||
4577                    (p->one->sha1_valid && p->two->sha1_valid) ||
4578                    (p->one->mode != p->two->mode) ||
4579                    diff_populate_filespec(p->one, 1) ||
4580                    diff_populate_filespec(p->two, 1) ||
4581                    (p->one->size != p->two->size) ||
4582                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4583                        diff_q(&outq, p);
4584                else {
4585                        /*
4586                         * The caller can subtract 1 from skip_stat_unmatch
4587                         * to determine how many paths were dirty only
4588                         * due to stat info mismatch.
4589                         */
4590                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4591                                diffopt->skip_stat_unmatch++;
4592                        diff_free_filepair(p);
4593                }
4594        }
4595        free(q->queue);
4596        *q = outq;
4597}
4598
4599static int diffnamecmp(const void *a_, const void *b_)
4600{
4601        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4602        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4603        const char *name_a, *name_b;
4604
4605        name_a = a->one ? a->one->path : a->two->path;
4606        name_b = b->one ? b->one->path : b->two->path;
4607        return strcmp(name_a, name_b);
4608}
4609
4610void diffcore_fix_diff_index(struct diff_options *options)
4611{
4612        struct diff_queue_struct *q = &diff_queued_diff;
4613        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4614}
4615
4616void diffcore_std(struct diff_options *options)
4617{
4618        if (options->skip_stat_unmatch)
4619                diffcore_skip_stat_unmatch(options);
4620        if (!options->found_follow) {
4621                /* See try_to_follow_renames() in tree-diff.c */
4622                if (options->break_opt != -1)
4623                        diffcore_break(options->break_opt);
4624                if (options->detect_rename)
4625                        diffcore_rename(options);
4626                if (options->break_opt != -1)
4627                        diffcore_merge_broken();
4628        }
4629        if (options->pickaxe)
4630                diffcore_pickaxe(options);
4631        if (options->orderfile)
4632                diffcore_order(options->orderfile);
4633        if (!options->found_follow)
4634                /* See try_to_follow_renames() in tree-diff.c */
4635                diff_resolve_rename_copy();
4636        diffcore_apply_filter(options->filter);
4637
4638        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4639                DIFF_OPT_SET(options, HAS_CHANGES);
4640        else
4641                DIFF_OPT_CLR(options, HAS_CHANGES);
4642
4643        options->found_follow = 0;
4644}
4645
4646int diff_result_code(struct diff_options *opt, int status)
4647{
4648        int result = 0;
4649
4650        diff_warn_rename_limit("diff.renamelimit",
4651                               opt->needed_rename_limit,
4652                               opt->degraded_cc_to_c);
4653        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4654            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4655                return status;
4656        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4657            DIFF_OPT_TST(opt, HAS_CHANGES))
4658                result |= 01;
4659        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4660            DIFF_OPT_TST(opt, CHECK_FAILED))
4661                result |= 02;
4662        return result;
4663}
4664
4665int diff_can_quit_early(struct diff_options *opt)
4666{
4667        return (DIFF_OPT_TST(opt, QUICK) &&
4668                !opt->filter &&
4669                DIFF_OPT_TST(opt, HAS_CHANGES));
4670}
4671
4672/*
4673 * Shall changes to this submodule be ignored?
4674 *
4675 * Submodule changes can be configured to be ignored separately for each path,
4676 * but that configuration can be overridden from the command line.
4677 */
4678static int is_submodule_ignored(const char *path, struct diff_options *options)
4679{
4680        int ignored = 0;
4681        unsigned orig_flags = options->flags;
4682        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4683                set_diffopt_flags_from_submodule_config(options, path);
4684        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4685                ignored = 1;
4686        options->flags = orig_flags;
4687        return ignored;
4688}
4689
4690void diff_addremove(struct diff_options *options,
4691                    int addremove, unsigned mode,
4692                    const unsigned char *sha1,
4693                    int sha1_valid,
4694                    const char *concatpath, unsigned dirty_submodule)
4695{
4696        struct diff_filespec *one, *two;
4697
4698        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4699                return;
4700
4701        /* This may look odd, but it is a preparation for
4702         * feeding "there are unchanged files which should
4703         * not produce diffs, but when you are doing copy
4704         * detection you would need them, so here they are"
4705         * entries to the diff-core.  They will be prefixed
4706         * with something like '=' or '*' (I haven't decided
4707         * which but should not make any difference).
4708         * Feeding the same new and old to diff_change()
4709         * also has the same effect.
4710         * Before the final output happens, they are pruned after
4711         * merged into rename/copy pairs as appropriate.
4712         */
4713        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4714                addremove = (addremove == '+' ? '-' :
4715                             addremove == '-' ? '+' : addremove);
4716
4717        if (options->prefix &&
4718            strncmp(concatpath, options->prefix, options->prefix_length))
4719                return;
4720
4721        one = alloc_filespec(concatpath);
4722        two = alloc_filespec(concatpath);
4723
4724        if (addremove != '+')
4725                fill_filespec(one, sha1, sha1_valid, mode);
4726        if (addremove != '-') {
4727                fill_filespec(two, sha1, sha1_valid, mode);
4728                two->dirty_submodule = dirty_submodule;
4729        }
4730
4731        diff_queue(&diff_queued_diff, one, two);
4732        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4733                DIFF_OPT_SET(options, HAS_CHANGES);
4734}
4735
4736void diff_change(struct diff_options *options,
4737                 unsigned old_mode, unsigned new_mode,
4738                 const unsigned char *old_sha1,
4739                 const unsigned char *new_sha1,
4740                 int old_sha1_valid, int new_sha1_valid,
4741                 const char *concatpath,
4742                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4743{
4744        struct diff_filespec *one, *two;
4745
4746        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4747            is_submodule_ignored(concatpath, options))
4748                return;
4749
4750        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4751                unsigned tmp;
4752                const unsigned char *tmp_c;
4753                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4754                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4755                tmp = old_sha1_valid; old_sha1_valid = new_sha1_valid;
4756                        new_sha1_valid = tmp;
4757                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4758                        new_dirty_submodule = tmp;
4759        }
4760
4761        if (options->prefix &&
4762            strncmp(concatpath, options->prefix, options->prefix_length))
4763                return;
4764
4765        one = alloc_filespec(concatpath);
4766        two = alloc_filespec(concatpath);
4767        fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
4768        fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
4769        one->dirty_submodule = old_dirty_submodule;
4770        two->dirty_submodule = new_dirty_submodule;
4771
4772        diff_queue(&diff_queued_diff, one, two);
4773        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4774                DIFF_OPT_SET(options, HAS_CHANGES);
4775}
4776
4777struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4778{
4779        struct diff_filepair *pair;
4780        struct diff_filespec *one, *two;
4781
4782        if (options->prefix &&
4783            strncmp(path, options->prefix, options->prefix_length))
4784                return NULL;
4785
4786        one = alloc_filespec(path);
4787        two = alloc_filespec(path);
4788        pair = diff_queue(&diff_queued_diff, one, two);
4789        pair->is_unmerged = 1;
4790        return pair;
4791}
4792
4793static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4794                size_t *outsize)
4795{
4796        struct diff_tempfile *temp;
4797        const char *argv[3];
4798        const char **arg = argv;
4799        struct child_process child;
4800        struct strbuf buf = STRBUF_INIT;
4801        int err = 0;
4802
4803        temp = prepare_temp_file(spec->path, spec);
4804        *arg++ = pgm;
4805        *arg++ = temp->name;
4806        *arg = NULL;
4807
4808        memset(&child, 0, sizeof(child));
4809        child.use_shell = 1;
4810        child.argv = argv;
4811        child.out = -1;
4812        if (start_command(&child)) {
4813                remove_tempfile();
4814                return NULL;
4815        }
4816
4817        if (strbuf_read(&buf, child.out, 0) < 0)
4818                err = error("error reading from textconv command '%s'", pgm);
4819        close(child.out);
4820
4821        if (finish_command(&child) || err) {
4822                strbuf_release(&buf);
4823                remove_tempfile();
4824                return NULL;
4825        }
4826        remove_tempfile();
4827
4828        return strbuf_detach(&buf, outsize);
4829}
4830
4831size_t fill_textconv(struct userdiff_driver *driver,
4832                     struct diff_filespec *df,
4833                     char **outbuf)
4834{
4835        size_t size;
4836
4837        if (!driver || !driver->textconv) {
4838                if (!DIFF_FILE_VALID(df)) {
4839                        *outbuf = "";
4840                        return 0;
4841                }
4842                if (diff_populate_filespec(df, 0))
4843                        die("unable to read files to diff");
4844                *outbuf = df->data;
4845                return df->size;
4846        }
4847
4848        if (driver->textconv_cache && df->sha1_valid) {
4849                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4850                                          &size);
4851                if (*outbuf)
4852                        return size;
4853        }
4854
4855        *outbuf = run_textconv(driver->textconv, df, &size);
4856        if (!*outbuf)
4857                die("unable to read files to diff");
4858
4859        if (driver->textconv_cache && df->sha1_valid) {
4860                /* ignore errors, as we might be in a readonly repository */
4861                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4862                                size);
4863                /*
4864                 * we could save up changes and flush them all at the end,
4865                 * but we would need an extra call after all diffing is done.
4866                 * Since generating a cache entry is the slow path anyway,
4867                 * this extra overhead probably isn't a big deal.
4868                 */
4869                notes_cache_write(driver->textconv_cache);
4870        }
4871
4872        return size;
4873}