diff.con commit Make 'git submodule update --force' always check out submodules. (01d4721)
   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;
  28int 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                emit_line_0(ecb->opt, plain, reset, '\\',
 578                            nneof, strlen(nneof));
 579        }
 580}
 581
 582static void emit_rewrite_diff(const char *name_a,
 583                              const char *name_b,
 584                              struct diff_filespec *one,
 585                              struct diff_filespec *two,
 586                              struct userdiff_driver *textconv_one,
 587                              struct userdiff_driver *textconv_two,
 588                              struct diff_options *o)
 589{
 590        int lc_a, lc_b;
 591        const char *name_a_tab, *name_b_tab;
 592        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 593        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 594        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 595        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 596        const char *a_prefix, *b_prefix;
 597        char *data_one, *data_two;
 598        size_t size_one, size_two;
 599        struct emit_callback ecbdata;
 600        char *line_prefix = "";
 601        struct strbuf *msgbuf;
 602
 603        if (o && o->output_prefix) {
 604                msgbuf = o->output_prefix(o, o->output_prefix_data);
 605                line_prefix = msgbuf->buf;
 606        }
 607
 608        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 609                a_prefix = o->b_prefix;
 610                b_prefix = o->a_prefix;
 611        } else {
 612                a_prefix = o->a_prefix;
 613                b_prefix = o->b_prefix;
 614        }
 615
 616        name_a += (*name_a == '/');
 617        name_b += (*name_b == '/');
 618        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 619        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 620
 621        strbuf_reset(&a_name);
 622        strbuf_reset(&b_name);
 623        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 624        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 625
 626        size_one = fill_textconv(textconv_one, one, &data_one);
 627        size_two = fill_textconv(textconv_two, two, &data_two);
 628
 629        memset(&ecbdata, 0, sizeof(ecbdata));
 630        ecbdata.color_diff = want_color(o->use_color);
 631        ecbdata.found_changesp = &o->found_changes;
 632        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 633        ecbdata.opt = o;
 634        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 635                mmfile_t mf1, mf2;
 636                mf1.ptr = (char *)data_one;
 637                mf2.ptr = (char *)data_two;
 638                mf1.size = size_one;
 639                mf2.size = size_two;
 640                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 641        }
 642        ecbdata.lno_in_preimage = 1;
 643        ecbdata.lno_in_postimage = 1;
 644
 645        lc_a = count_lines(data_one, size_one);
 646        lc_b = count_lines(data_two, size_two);
 647        fprintf(o->file,
 648                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 649                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 650                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 651                line_prefix, fraginfo);
 652        if (!o->irreversible_delete)
 653                print_line_count(o->file, lc_a);
 654        else
 655                fprintf(o->file, "?,?");
 656        fprintf(o->file, " +");
 657        print_line_count(o->file, lc_b);
 658        fprintf(o->file, " @@%s\n", reset);
 659        if (lc_a && !o->irreversible_delete)
 660                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 661        if (lc_b)
 662                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 663        if (textconv_one)
 664                free((char *)data_one);
 665        if (textconv_two)
 666                free((char *)data_two);
 667}
 668
 669struct diff_words_buffer {
 670        mmfile_t text;
 671        long alloc;
 672        struct diff_words_orig {
 673                const char *begin, *end;
 674        } *orig;
 675        int orig_nr, orig_alloc;
 676};
 677
 678static void diff_words_append(char *line, unsigned long len,
 679                struct diff_words_buffer *buffer)
 680{
 681        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 682        line++;
 683        len--;
 684        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 685        buffer->text.size += len;
 686        buffer->text.ptr[buffer->text.size] = '\0';
 687}
 688
 689struct diff_words_style_elem {
 690        const char *prefix;
 691        const char *suffix;
 692        const char *color; /* NULL; filled in by the setup code if
 693                            * color is enabled */
 694};
 695
 696struct diff_words_style {
 697        enum diff_words_type type;
 698        struct diff_words_style_elem new, old, ctx;
 699        const char *newline;
 700};
 701
 702static struct diff_words_style diff_words_styles[] = {
 703        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 704        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 705        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 706};
 707
 708struct diff_words_data {
 709        struct diff_words_buffer minus, plus;
 710        const char *current_plus;
 711        int last_minus;
 712        struct diff_options *opt;
 713        regex_t *word_regex;
 714        enum diff_words_type type;
 715        struct diff_words_style *style;
 716};
 717
 718static int fn_out_diff_words_write_helper(FILE *fp,
 719                                          struct diff_words_style_elem *st_el,
 720                                          const char *newline,
 721                                          size_t count, const char *buf,
 722                                          const char *line_prefix)
 723{
 724        int print = 0;
 725
 726        while (count) {
 727                char *p = memchr(buf, '\n', count);
 728                if (print)
 729                        fputs(line_prefix, fp);
 730                if (p != buf) {
 731                        if (st_el->color && fputs(st_el->color, fp) < 0)
 732                                return -1;
 733                        if (fputs(st_el->prefix, fp) < 0 ||
 734                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 735                            fputs(st_el->suffix, fp) < 0)
 736                                return -1;
 737                        if (st_el->color && *st_el->color
 738                            && fputs(GIT_COLOR_RESET, fp) < 0)
 739                                return -1;
 740                }
 741                if (!p)
 742                        return 0;
 743                if (fputs(newline, fp) < 0)
 744                        return -1;
 745                count -= p + 1 - buf;
 746                buf = p + 1;
 747                print = 1;
 748        }
 749        return 0;
 750}
 751
 752/*
 753 * '--color-words' algorithm can be described as:
 754 *
 755 *   1. collect a the minus/plus lines of a diff hunk, divided into
 756 *      minus-lines and plus-lines;
 757 *
 758 *   2. break both minus-lines and plus-lines into words and
 759 *      place them into two mmfile_t with one word for each line;
 760 *
 761 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 762 *
 763 * And for the common parts of the both file, we output the plus side text.
 764 * diff_words->current_plus is used to trace the current position of the plus file
 765 * which printed. diff_words->last_minus is used to trace the last minus word
 766 * printed.
 767 *
 768 * For '--graph' to work with '--color-words', we need to output the graph prefix
 769 * on each line of color words output. Generally, there are two conditions on
 770 * which we should output the prefix.
 771 *
 772 *   1. diff_words->last_minus == 0 &&
 773 *      diff_words->current_plus == diff_words->plus.text.ptr
 774 *
 775 *      that is: the plus text must start as a new line, and if there is no minus
 776 *      word printed, a graph prefix must be printed.
 777 *
 778 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 779 *      *(diff_words->current_plus - 1) == '\n'
 780 *
 781 *      that is: a graph prefix must be printed following a '\n'
 782 */
 783static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 784{
 785        if ((diff_words->last_minus == 0 &&
 786                diff_words->current_plus == diff_words->plus.text.ptr) ||
 787                (diff_words->current_plus > diff_words->plus.text.ptr &&
 788                *(diff_words->current_plus - 1) == '\n')) {
 789                return 1;
 790        } else {
 791                return 0;
 792        }
 793}
 794
 795static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 796{
 797        struct diff_words_data *diff_words = priv;
 798        struct diff_words_style *style = diff_words->style;
 799        int minus_first, minus_len, plus_first, plus_len;
 800        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 801        struct diff_options *opt = diff_words->opt;
 802        struct strbuf *msgbuf;
 803        char *line_prefix = "";
 804
 805        if (line[0] != '@' || parse_hunk_header(line, len,
 806                        &minus_first, &minus_len, &plus_first, &plus_len))
 807                return;
 808
 809        assert(opt);
 810        if (opt->output_prefix) {
 811                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 812                line_prefix = msgbuf->buf;
 813        }
 814
 815        /* POSIX requires that first be decremented by one if len == 0... */
 816        if (minus_len) {
 817                minus_begin = diff_words->minus.orig[minus_first].begin;
 818                minus_end =
 819                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 820        } else
 821                minus_begin = minus_end =
 822                        diff_words->minus.orig[minus_first].end;
 823
 824        if (plus_len) {
 825                plus_begin = diff_words->plus.orig[plus_first].begin;
 826                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 827        } else
 828                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 829
 830        if (color_words_output_graph_prefix(diff_words)) {
 831                fputs(line_prefix, diff_words->opt->file);
 832        }
 833        if (diff_words->current_plus != plus_begin) {
 834                fn_out_diff_words_write_helper(diff_words->opt->file,
 835                                &style->ctx, style->newline,
 836                                plus_begin - diff_words->current_plus,
 837                                diff_words->current_plus, line_prefix);
 838                if (*(plus_begin - 1) == '\n')
 839                        fputs(line_prefix, diff_words->opt->file);
 840        }
 841        if (minus_begin != minus_end) {
 842                fn_out_diff_words_write_helper(diff_words->opt->file,
 843                                &style->old, style->newline,
 844                                minus_end - minus_begin, minus_begin,
 845                                line_prefix);
 846        }
 847        if (plus_begin != plus_end) {
 848                fn_out_diff_words_write_helper(diff_words->opt->file,
 849                                &style->new, style->newline,
 850                                plus_end - plus_begin, plus_begin,
 851                                line_prefix);
 852        }
 853
 854        diff_words->current_plus = plus_end;
 855        diff_words->last_minus = minus_first;
 856}
 857
 858/* This function starts looking at *begin, and returns 0 iff a word was found. */
 859static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 860                int *begin, int *end)
 861{
 862        if (word_regex && *begin < buffer->size) {
 863                regmatch_t match[1];
 864                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 865                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 866                                        '\n', match[0].rm_eo - match[0].rm_so);
 867                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 868                        *begin += match[0].rm_so;
 869                        return *begin >= *end;
 870                }
 871                return -1;
 872        }
 873
 874        /* find the next word */
 875        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 876                (*begin)++;
 877        if (*begin >= buffer->size)
 878                return -1;
 879
 880        /* find the end of the word */
 881        *end = *begin + 1;
 882        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 883                (*end)++;
 884
 885        return 0;
 886}
 887
 888/*
 889 * This function splits the words in buffer->text, stores the list with
 890 * newline separator into out, and saves the offsets of the original words
 891 * in buffer->orig.
 892 */
 893static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 894                regex_t *word_regex)
 895{
 896        int i, j;
 897        long alloc = 0;
 898
 899        out->size = 0;
 900        out->ptr = NULL;
 901
 902        /* fake an empty "0th" word */
 903        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 904        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 905        buffer->orig_nr = 1;
 906
 907        for (i = 0; i < buffer->text.size; i++) {
 908                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 909                        return;
 910
 911                /* store original boundaries */
 912                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 913                                buffer->orig_alloc);
 914                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 915                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 916                buffer->orig_nr++;
 917
 918                /* store one word */
 919                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 920                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 921                out->ptr[out->size + j - i] = '\n';
 922                out->size += j - i + 1;
 923
 924                i = j - 1;
 925        }
 926}
 927
 928/* this executes the word diff on the accumulated buffers */
 929static void diff_words_show(struct diff_words_data *diff_words)
 930{
 931        xpparam_t xpp;
 932        xdemitconf_t xecfg;
 933        mmfile_t minus, plus;
 934        struct diff_words_style *style = diff_words->style;
 935
 936        struct diff_options *opt = diff_words->opt;
 937        struct strbuf *msgbuf;
 938        char *line_prefix = "";
 939
 940        assert(opt);
 941        if (opt->output_prefix) {
 942                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 943                line_prefix = msgbuf->buf;
 944        }
 945
 946        /* special case: only removal */
 947        if (!diff_words->plus.text.size) {
 948                fputs(line_prefix, diff_words->opt->file);
 949                fn_out_diff_words_write_helper(diff_words->opt->file,
 950                        &style->old, style->newline,
 951                        diff_words->minus.text.size,
 952                        diff_words->minus.text.ptr, line_prefix);
 953                diff_words->minus.text.size = 0;
 954                return;
 955        }
 956
 957        diff_words->current_plus = diff_words->plus.text.ptr;
 958        diff_words->last_minus = 0;
 959
 960        memset(&xpp, 0, sizeof(xpp));
 961        memset(&xecfg, 0, sizeof(xecfg));
 962        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 963        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 964        xpp.flags = 0;
 965        /* as only the hunk header will be parsed, we need a 0-context */
 966        xecfg.ctxlen = 0;
 967        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 968                      &xpp, &xecfg);
 969        free(minus.ptr);
 970        free(plus.ptr);
 971        if (diff_words->current_plus != diff_words->plus.text.ptr +
 972                        diff_words->plus.text.size) {
 973                if (color_words_output_graph_prefix(diff_words))
 974                        fputs(line_prefix, diff_words->opt->file);
 975                fn_out_diff_words_write_helper(diff_words->opt->file,
 976                        &style->ctx, style->newline,
 977                        diff_words->plus.text.ptr + diff_words->plus.text.size
 978                        - diff_words->current_plus, diff_words->current_plus,
 979                        line_prefix);
 980        }
 981        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 982}
 983
 984/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 985static void diff_words_flush(struct emit_callback *ecbdata)
 986{
 987        if (ecbdata->diff_words->minus.text.size ||
 988            ecbdata->diff_words->plus.text.size)
 989                diff_words_show(ecbdata->diff_words);
 990}
 991
 992static void diff_filespec_load_driver(struct diff_filespec *one)
 993{
 994        /* Use already-loaded driver */
 995        if (one->driver)
 996                return;
 997
 998        if (S_ISREG(one->mode))
 999                one->driver = userdiff_find_by_path(one->path);
1000
1001        /* Fallback to default settings */
1002        if (!one->driver)
1003                one->driver = userdiff_find_by_name("default");
1004}
1005
1006static const char *userdiff_word_regex(struct diff_filespec *one)
1007{
1008        diff_filespec_load_driver(one);
1009        return one->driver->word_regex;
1010}
1011
1012static void init_diff_words_data(struct emit_callback *ecbdata,
1013                                 struct diff_options *orig_opts,
1014                                 struct diff_filespec *one,
1015                                 struct diff_filespec *two)
1016{
1017        int i;
1018        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1019        memcpy(o, orig_opts, sizeof(struct diff_options));
1020
1021        ecbdata->diff_words =
1022                xcalloc(1, sizeof(struct diff_words_data));
1023        ecbdata->diff_words->type = o->word_diff;
1024        ecbdata->diff_words->opt = o;
1025        if (!o->word_regex)
1026                o->word_regex = userdiff_word_regex(one);
1027        if (!o->word_regex)
1028                o->word_regex = userdiff_word_regex(two);
1029        if (!o->word_regex)
1030                o->word_regex = diff_word_regex_cfg;
1031        if (o->word_regex) {
1032                ecbdata->diff_words->word_regex = (regex_t *)
1033                        xmalloc(sizeof(regex_t));
1034                if (regcomp(ecbdata->diff_words->word_regex,
1035                            o->word_regex,
1036                            REG_EXTENDED | REG_NEWLINE))
1037                        die ("Invalid regular expression: %s",
1038                             o->word_regex);
1039        }
1040        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1041                if (o->word_diff == diff_words_styles[i].type) {
1042                        ecbdata->diff_words->style =
1043                                &diff_words_styles[i];
1044                        break;
1045                }
1046        }
1047        if (want_color(o->use_color)) {
1048                struct diff_words_style *st = ecbdata->diff_words->style;
1049                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1050                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1051                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
1052        }
1053}
1054
1055static void free_diff_words_data(struct emit_callback *ecbdata)
1056{
1057        if (ecbdata->diff_words) {
1058                diff_words_flush(ecbdata);
1059                free (ecbdata->diff_words->opt);
1060                free (ecbdata->diff_words->minus.text.ptr);
1061                free (ecbdata->diff_words->minus.orig);
1062                free (ecbdata->diff_words->plus.text.ptr);
1063                free (ecbdata->diff_words->plus.orig);
1064                if (ecbdata->diff_words->word_regex) {
1065                        regfree(ecbdata->diff_words->word_regex);
1066                        free(ecbdata->diff_words->word_regex);
1067                }
1068                free(ecbdata->diff_words);
1069                ecbdata->diff_words = NULL;
1070        }
1071}
1072
1073const char *diff_get_color(int diff_use_color, enum color_diff ix)
1074{
1075        if (want_color(diff_use_color))
1076                return diff_colors[ix];
1077        return "";
1078}
1079
1080static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1081{
1082        const char *cp;
1083        unsigned long allot;
1084        size_t l = len;
1085
1086        if (ecb->truncate)
1087                return ecb->truncate(line, len);
1088        cp = line;
1089        allot = l;
1090        while (0 < l) {
1091                (void) utf8_width(&cp, &l);
1092                if (!cp)
1093                        break; /* truncated in the middle? */
1094        }
1095        return allot - l;
1096}
1097
1098static void find_lno(const char *line, struct emit_callback *ecbdata)
1099{
1100        const char *p;
1101        ecbdata->lno_in_preimage = 0;
1102        ecbdata->lno_in_postimage = 0;
1103        p = strchr(line, '-');
1104        if (!p)
1105                return; /* cannot happen */
1106        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1107        p = strchr(p, '+');
1108        if (!p)
1109                return; /* cannot happen */
1110        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1111}
1112
1113static void fn_out_consume(void *priv, char *line, unsigned long len)
1114{
1115        struct emit_callback *ecbdata = priv;
1116        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1117        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1118        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1119        struct diff_options *o = ecbdata->opt;
1120        char *line_prefix = "";
1121        struct strbuf *msgbuf;
1122
1123        if (o && o->output_prefix) {
1124                msgbuf = o->output_prefix(o, o->output_prefix_data);
1125                line_prefix = msgbuf->buf;
1126        }
1127
1128        if (ecbdata->header) {
1129                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1130                strbuf_reset(ecbdata->header);
1131                ecbdata->header = NULL;
1132        }
1133        *(ecbdata->found_changesp) = 1;
1134
1135        if (ecbdata->label_path[0]) {
1136                const char *name_a_tab, *name_b_tab;
1137
1138                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1139                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1140
1141                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1142                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1143                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1144                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1145                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1146        }
1147
1148        if (diff_suppress_blank_empty
1149            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1150                line[0] = '\n';
1151                len = 1;
1152        }
1153
1154        if (line[0] == '@') {
1155                if (ecbdata->diff_words)
1156                        diff_words_flush(ecbdata);
1157                len = sane_truncate_line(ecbdata, line, len);
1158                find_lno(line, ecbdata);
1159                emit_hunk_header(ecbdata, line, len);
1160                if (line[len-1] != '\n')
1161                        putc('\n', ecbdata->opt->file);
1162                return;
1163        }
1164
1165        if (len < 1) {
1166                emit_line(ecbdata->opt, reset, reset, line, len);
1167                if (ecbdata->diff_words
1168                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1169                        fputs("~\n", ecbdata->opt->file);
1170                return;
1171        }
1172
1173        if (ecbdata->diff_words) {
1174                if (line[0] == '-') {
1175                        diff_words_append(line, len,
1176                                          &ecbdata->diff_words->minus);
1177                        return;
1178                } else if (line[0] == '+') {
1179                        diff_words_append(line, len,
1180                                          &ecbdata->diff_words->plus);
1181                        return;
1182                } else if (!prefixcmp(line, "\\ ")) {
1183                        /*
1184                         * Eat the "no newline at eof" marker as if we
1185                         * saw a "+" or "-" line with nothing on it,
1186                         * and return without diff_words_flush() to
1187                         * defer processing. If this is the end of
1188                         * preimage, more "+" lines may come after it.
1189                         */
1190                        return;
1191                }
1192                diff_words_flush(ecbdata);
1193                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1194                        emit_line(ecbdata->opt, plain, reset, line, len);
1195                        fputs("~\n", ecbdata->opt->file);
1196                } else {
1197                        /*
1198                         * Skip the prefix character, if any.  With
1199                         * diff_suppress_blank_empty, there may be
1200                         * none.
1201                         */
1202                        if (line[0] != '\n') {
1203                              line++;
1204                              len--;
1205                        }
1206                        emit_line(ecbdata->opt, plain, reset, line, len);
1207                }
1208                return;
1209        }
1210
1211        if (line[0] != '+') {
1212                const char *color =
1213                        diff_get_color(ecbdata->color_diff,
1214                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1215                ecbdata->lno_in_preimage++;
1216                if (line[0] == ' ')
1217                        ecbdata->lno_in_postimage++;
1218                emit_line(ecbdata->opt, color, reset, line, len);
1219        } else {
1220                ecbdata->lno_in_postimage++;
1221                emit_add_line(reset, ecbdata, line + 1, len - 1);
1222        }
1223}
1224
1225static char *pprint_rename(const char *a, const char *b)
1226{
1227        const char *old = a;
1228        const char *new = b;
1229        struct strbuf name = STRBUF_INIT;
1230        int pfx_length, sfx_length;
1231        int len_a = strlen(a);
1232        int len_b = strlen(b);
1233        int a_midlen, b_midlen;
1234        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1235        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1236
1237        if (qlen_a || qlen_b) {
1238                quote_c_style(a, &name, NULL, 0);
1239                strbuf_addstr(&name, " => ");
1240                quote_c_style(b, &name, NULL, 0);
1241                return strbuf_detach(&name, NULL);
1242        }
1243
1244        /* Find common prefix */
1245        pfx_length = 0;
1246        while (*old && *new && *old == *new) {
1247                if (*old == '/')
1248                        pfx_length = old - a + 1;
1249                old++;
1250                new++;
1251        }
1252
1253        /* Find common suffix */
1254        old = a + len_a;
1255        new = b + len_b;
1256        sfx_length = 0;
1257        while (a <= old && b <= new && *old == *new) {
1258                if (*old == '/')
1259                        sfx_length = len_a - (old - a);
1260                old--;
1261                new--;
1262        }
1263
1264        /*
1265         * pfx{mid-a => mid-b}sfx
1266         * {pfx-a => pfx-b}sfx
1267         * pfx{sfx-a => sfx-b}
1268         * name-a => name-b
1269         */
1270        a_midlen = len_a - pfx_length - sfx_length;
1271        b_midlen = len_b - pfx_length - sfx_length;
1272        if (a_midlen < 0)
1273                a_midlen = 0;
1274        if (b_midlen < 0)
1275                b_midlen = 0;
1276
1277        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1278        if (pfx_length + sfx_length) {
1279                strbuf_add(&name, a, pfx_length);
1280                strbuf_addch(&name, '{');
1281        }
1282        strbuf_add(&name, a + pfx_length, a_midlen);
1283        strbuf_addstr(&name, " => ");
1284        strbuf_add(&name, b + pfx_length, b_midlen);
1285        if (pfx_length + sfx_length) {
1286                strbuf_addch(&name, '}');
1287                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1288        }
1289        return strbuf_detach(&name, NULL);
1290}
1291
1292struct diffstat_t {
1293        int nr;
1294        int alloc;
1295        struct diffstat_file {
1296                char *from_name;
1297                char *name;
1298                char *print_name;
1299                unsigned is_unmerged:1;
1300                unsigned is_binary:1;
1301                unsigned is_renamed:1;
1302                uintmax_t added, deleted;
1303        } **files;
1304};
1305
1306static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1307                                          const char *name_a,
1308                                          const char *name_b)
1309{
1310        struct diffstat_file *x;
1311        x = xcalloc(sizeof (*x), 1);
1312        if (diffstat->nr == diffstat->alloc) {
1313                diffstat->alloc = alloc_nr(diffstat->alloc);
1314                diffstat->files = xrealloc(diffstat->files,
1315                                diffstat->alloc * sizeof(x));
1316        }
1317        diffstat->files[diffstat->nr++] = x;
1318        if (name_b) {
1319                x->from_name = xstrdup(name_a);
1320                x->name = xstrdup(name_b);
1321                x->is_renamed = 1;
1322        }
1323        else {
1324                x->from_name = NULL;
1325                x->name = xstrdup(name_a);
1326        }
1327        return x;
1328}
1329
1330static void diffstat_consume(void *priv, char *line, unsigned long len)
1331{
1332        struct diffstat_t *diffstat = priv;
1333        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1334
1335        if (line[0] == '+')
1336                x->added++;
1337        else if (line[0] == '-')
1338                x->deleted++;
1339}
1340
1341const char mime_boundary_leader[] = "------------";
1342
1343static int scale_linear(int it, int width, int max_change)
1344{
1345        if (!it)
1346                return 0;
1347        /*
1348         * make sure that at least one '-' or '+' is printed if
1349         * there is any change to this path. The easiest way is to
1350         * scale linearly as if the alloted width is one column shorter
1351         * than it is, and then add 1 to the result.
1352         */
1353        return 1 + (it * (width - 1) / max_change);
1354}
1355
1356static void show_name(FILE *file,
1357                      const char *prefix, const char *name, int len)
1358{
1359        fprintf(file, " %s%-*s |", prefix, len, name);
1360}
1361
1362static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1363{
1364        if (cnt <= 0)
1365                return;
1366        fprintf(file, "%s", set);
1367        while (cnt--)
1368                putc(ch, file);
1369        fprintf(file, "%s", reset);
1370}
1371
1372static void fill_print_name(struct diffstat_file *file)
1373{
1374        char *pname;
1375
1376        if (file->print_name)
1377                return;
1378
1379        if (!file->is_renamed) {
1380                struct strbuf buf = STRBUF_INIT;
1381                if (quote_c_style(file->name, &buf, NULL, 0)) {
1382                        pname = strbuf_detach(&buf, NULL);
1383                } else {
1384                        pname = file->name;
1385                        strbuf_release(&buf);
1386                }
1387        } else {
1388                pname = pprint_rename(file->from_name, file->name);
1389        }
1390        file->print_name = pname;
1391}
1392
1393int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1394{
1395        struct strbuf sb = STRBUF_INIT;
1396        int ret;
1397
1398        if (!files) {
1399                assert(insertions == 0 && deletions == 0);
1400                return fputs(_(" 0 files changed\n"), fp);
1401        }
1402
1403        strbuf_addf(&sb,
1404                    Q_(" %d file changed", " %d files changed", files),
1405                    files);
1406
1407        /*
1408         * For binary diff, the caller may want to print "x files
1409         * changed" with insertions == 0 && deletions == 0.
1410         *
1411         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1412         * is probably less confusing (i.e skip over "2 files changed
1413         * but nothing about added/removed lines? Is this a bug in Git?").
1414         */
1415        if (insertions || deletions == 0) {
1416                /*
1417                 * TRANSLATORS: "+" in (+) is a line addition marker;
1418                 * do not translate it.
1419                 */
1420                strbuf_addf(&sb,
1421                            Q_(", %d insertion(+)", ", %d insertions(+)",
1422                               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                            Q_(", %d deletion(-)", ", %d deletions(-)",
1433                               deletions),
1434                            deletions);
1435        }
1436        strbuf_addch(&sb, '\n');
1437        ret = fputs(sb.buf, fp);
1438        strbuf_release(&sb);
1439        return ret;
1440}
1441
1442static void show_stats(struct diffstat_t *data, struct diff_options *options)
1443{
1444        int i, len, add, del, adds = 0, dels = 0;
1445        uintmax_t max_change = 0, max_len = 0;
1446        int total_files = data->nr, count;
1447        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1448        const char *reset, *add_c, *del_c;
1449        const char *line_prefix = "";
1450        int extra_shown = 0;
1451        struct strbuf *msg = NULL;
1452
1453        if (data->nr == 0)
1454                return;
1455
1456        if (options->output_prefix) {
1457                msg = options->output_prefix(options, options->output_prefix_data);
1458                line_prefix = msg->buf;
1459        }
1460
1461        count = options->stat_count ? options->stat_count : data->nr;
1462
1463        reset = diff_get_color_opt(options, DIFF_RESET);
1464        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1465        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1466
1467        /*
1468         * Find the longest filename and max number of changes
1469         */
1470        for (i = 0; (i < count) && (i < data->nr); i++) {
1471                struct diffstat_file *file = data->files[i];
1472                uintmax_t change = file->added + file->deleted;
1473                if (!data->files[i]->is_renamed &&
1474                         (change == 0)) {
1475                        count++; /* not shown == room for one more */
1476                        continue;
1477                }
1478                fill_print_name(file);
1479                len = strlen(file->print_name);
1480                if (max_len < len)
1481                        max_len = len;
1482
1483                if (file->is_unmerged) {
1484                        /* "Unmerged" is 8 characters */
1485                        bin_width = bin_width < 8 ? 8 : bin_width;
1486                        continue;
1487                }
1488                if (file->is_binary) {
1489                        /* "Bin XXX -> YYY bytes" */
1490                        int w = 14 + decimal_width(file->added)
1491                                + decimal_width(file->deleted);
1492                        bin_width = bin_width < w ? w : bin_width;
1493                        /* Display change counts aligned with "Bin" */
1494                        number_width = 3;
1495                        continue;
1496                }
1497
1498                if (max_change < change)
1499                        max_change = change;
1500        }
1501        count = i; /* min(count, data->nr) */
1502
1503        /*
1504         * We have width = stat_width or term_columns() columns total.
1505         * We want a maximum of min(max_len, stat_name_width) for the name part.
1506         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1507         * We also need 1 for " " and 4 + decimal_width(max_change)
1508         * for " | NNNN " and one the empty column at the end, altogether
1509         * 6 + decimal_width(max_change).
1510         *
1511         * If there's not enough space, we will use the smaller of
1512         * stat_name_width (if set) and 5/8*width for the filename,
1513         * and the rest for constant elements + graph part, but no more
1514         * than stat_graph_width for the graph part.
1515         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1516         * for the standard terminal size).
1517         *
1518         * In other words: stat_width limits the maximum width, and
1519         * stat_name_width fixes the maximum width of the filename,
1520         * and is also used to divide available columns if there
1521         * aren't enough.
1522         *
1523         * Binary files are displayed with "Bin XXX -> YYY bytes"
1524         * instead of the change count and graph. This part is treated
1525         * similarly to the graph part, except that it is not
1526         * "scaled". If total width is too small to accomodate the
1527         * guaranteed minimum width of the filename part and the
1528         * separators and this message, this message will "overflow"
1529         * making the line longer than the maximum width.
1530         */
1531
1532        if (options->stat_width == -1)
1533                width = term_columns() - options->output_prefix_length;
1534        else
1535                width = options->stat_width ? options->stat_width : 80;
1536        number_width = decimal_width(max_change) > number_width ?
1537                decimal_width(max_change) : number_width;
1538
1539        if (options->stat_graph_width == -1)
1540                options->stat_graph_width = diff_stat_graph_width;
1541
1542        /*
1543         * Guarantee 3/8*16==6 for the graph part
1544         * and 5/8*16==10 for the filename part
1545         */
1546        if (width < 16 + 6 + number_width)
1547                width = 16 + 6 + number_width;
1548
1549        /*
1550         * First assign sizes that are wanted, ignoring available width.
1551         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1552         * starting from "XXX" should fit in graph_width.
1553         */
1554        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1555        if (options->stat_graph_width &&
1556            options->stat_graph_width < graph_width)
1557                graph_width = options->stat_graph_width;
1558
1559        name_width = (options->stat_name_width > 0 &&
1560                      options->stat_name_width < max_len) ?
1561                options->stat_name_width : max_len;
1562
1563        /*
1564         * Adjust adjustable widths not to exceed maximum width
1565         */
1566        if (name_width + number_width + 6 + graph_width > width) {
1567                if (graph_width > width * 3/8 - number_width - 6) {
1568                        graph_width = width * 3/8 - number_width - 6;
1569                        if (graph_width < 6)
1570                                graph_width = 6;
1571                }
1572
1573                if (options->stat_graph_width &&
1574                    graph_width > options->stat_graph_width)
1575                        graph_width = options->stat_graph_width;
1576                if (name_width > width - number_width - 6 - graph_width)
1577                        name_width = width - number_width - 6 - graph_width;
1578                else
1579                        graph_width = width - number_width - 6 - name_width;
1580        }
1581
1582        /*
1583         * From here name_width is the width of the name area,
1584         * and graph_width is the width of the graph area.
1585         * max_change is used to scale graph properly.
1586         */
1587        for (i = 0; i < count; i++) {
1588                const char *prefix = "";
1589                char *name = data->files[i]->print_name;
1590                uintmax_t added = data->files[i]->added;
1591                uintmax_t deleted = data->files[i]->deleted;
1592                int name_len;
1593
1594                if (!data->files[i]->is_renamed &&
1595                         (added + deleted == 0)) {
1596                        total_files--;
1597                        continue;
1598                }
1599                /*
1600                 * "scale" the filename
1601                 */
1602                len = name_width;
1603                name_len = strlen(name);
1604                if (name_width < name_len) {
1605                        char *slash;
1606                        prefix = "...";
1607                        len -= 3;
1608                        name += name_len - len;
1609                        slash = strchr(name, '/');
1610                        if (slash)
1611                                name = slash;
1612                }
1613
1614                if (data->files[i]->is_binary) {
1615                        fprintf(options->file, "%s", line_prefix);
1616                        show_name(options->file, prefix, name, len);
1617                        fprintf(options->file, " %*s", number_width, "Bin");
1618                        if (!added && !deleted) {
1619                                putc('\n', options->file);
1620                                continue;
1621                        }
1622                        fprintf(options->file, " %s%"PRIuMAX"%s",
1623                                del_c, deleted, reset);
1624                        fprintf(options->file, " -> ");
1625                        fprintf(options->file, "%s%"PRIuMAX"%s",
1626                                add_c, added, reset);
1627                        fprintf(options->file, " bytes");
1628                        fprintf(options->file, "\n");
1629                        continue;
1630                }
1631                else if (data->files[i]->is_unmerged) {
1632                        fprintf(options->file, "%s", line_prefix);
1633                        show_name(options->file, prefix, name, len);
1634                        fprintf(options->file, " Unmerged\n");
1635                        continue;
1636                }
1637
1638                /*
1639                 * scale the add/delete
1640                 */
1641                add = added;
1642                del = deleted;
1643                adds += add;
1644                dels += del;
1645
1646                if (graph_width <= max_change) {
1647                        int total = add + del;
1648
1649                        total = scale_linear(add + del, graph_width, max_change);
1650                        if (total < 2 && add && del)
1651                                /* width >= 2 due to the sanity check */
1652                                total = 2;
1653                        if (add < del) {
1654                                add = scale_linear(add, graph_width, max_change);
1655                                del = total - add;
1656                        } else {
1657                                del = scale_linear(del, graph_width, max_change);
1658                                add = total - del;
1659                        }
1660                }
1661                fprintf(options->file, "%s", line_prefix);
1662                show_name(options->file, prefix, name, len);
1663                fprintf(options->file, " %*"PRIuMAX"%s",
1664                        number_width, added + deleted,
1665                        added + deleted ? " " : "");
1666                show_graph(options->file, '+', add, add_c, reset);
1667                show_graph(options->file, '-', del, del_c, reset);
1668                fprintf(options->file, "\n");
1669        }
1670        for (i = count; i < data->nr; i++) {
1671                uintmax_t added = data->files[i]->added;
1672                uintmax_t deleted = data->files[i]->deleted;
1673                if (!data->files[i]->is_renamed &&
1674                         (added + deleted == 0)) {
1675                        total_files--;
1676                        continue;
1677                }
1678                adds += added;
1679                dels += deleted;
1680                if (!extra_shown)
1681                        fprintf(options->file, "%s ...\n", line_prefix);
1682                extra_shown = 1;
1683        }
1684        fprintf(options->file, "%s", line_prefix);
1685        print_stat_summary(options->file, total_files, adds, dels);
1686}
1687
1688static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1689{
1690        int i, adds = 0, dels = 0, total_files = data->nr;
1691
1692        if (data->nr == 0)
1693                return;
1694
1695        for (i = 0; i < data->nr; i++) {
1696                int added = data->files[i]->added;
1697                int deleted= data->files[i]->deleted;
1698
1699                if (data->files[i]->is_unmerged)
1700                        continue;
1701                if (!data->files[i]->is_renamed && (added + deleted == 0)) {
1702                        total_files--;
1703                } else if (!data->files[i]->is_binary) { /* don't count bytes */
1704                        adds += added;
1705                        dels += deleted;
1706                }
1707        }
1708        if (options->output_prefix) {
1709                struct strbuf *msg = NULL;
1710                msg = options->output_prefix(options,
1711                                options->output_prefix_data);
1712                fprintf(options->file, "%s", msg->buf);
1713        }
1714        print_stat_summary(options->file, total_files, adds, dels);
1715}
1716
1717static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1718{
1719        int i;
1720
1721        if (data->nr == 0)
1722                return;
1723
1724        for (i = 0; i < data->nr; i++) {
1725                struct diffstat_file *file = data->files[i];
1726
1727                if (options->output_prefix) {
1728                        struct strbuf *msg = NULL;
1729                        msg = options->output_prefix(options,
1730                                        options->output_prefix_data);
1731                        fprintf(options->file, "%s", msg->buf);
1732                }
1733
1734                if (file->is_binary)
1735                        fprintf(options->file, "-\t-\t");
1736                else
1737                        fprintf(options->file,
1738                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1739                                file->added, file->deleted);
1740                if (options->line_termination) {
1741                        fill_print_name(file);
1742                        if (!file->is_renamed)
1743                                write_name_quoted(file->name, options->file,
1744                                                  options->line_termination);
1745                        else {
1746                                fputs(file->print_name, options->file);
1747                                putc(options->line_termination, options->file);
1748                        }
1749                } else {
1750                        if (file->is_renamed) {
1751                                putc('\0', options->file);
1752                                write_name_quoted(file->from_name, options->file, '\0');
1753                        }
1754                        write_name_quoted(file->name, options->file, '\0');
1755                }
1756        }
1757}
1758
1759struct dirstat_file {
1760        const char *name;
1761        unsigned long changed;
1762};
1763
1764struct dirstat_dir {
1765        struct dirstat_file *files;
1766        int alloc, nr, permille, cumulative;
1767};
1768
1769static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1770                unsigned long changed, const char *base, int baselen)
1771{
1772        unsigned long this_dir = 0;
1773        unsigned int sources = 0;
1774        const char *line_prefix = "";
1775        struct strbuf *msg = NULL;
1776
1777        if (opt->output_prefix) {
1778                msg = opt->output_prefix(opt, opt->output_prefix_data);
1779                line_prefix = msg->buf;
1780        }
1781
1782        while (dir->nr) {
1783                struct dirstat_file *f = dir->files;
1784                int namelen = strlen(f->name);
1785                unsigned long this;
1786                char *slash;
1787
1788                if (namelen < baselen)
1789                        break;
1790                if (memcmp(f->name, base, baselen))
1791                        break;
1792                slash = strchr(f->name + baselen, '/');
1793                if (slash) {
1794                        int newbaselen = slash + 1 - f->name;
1795                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1796                        sources++;
1797                } else {
1798                        this = f->changed;
1799                        dir->files++;
1800                        dir->nr--;
1801                        sources += 2;
1802                }
1803                this_dir += this;
1804        }
1805
1806        /*
1807         * We don't report dirstat's for
1808         *  - the top level
1809         *  - or cases where everything came from a single directory
1810         *    under this directory (sources == 1).
1811         */
1812        if (baselen && sources != 1) {
1813                if (this_dir) {
1814                        int permille = this_dir * 1000 / changed;
1815                        if (permille >= dir->permille) {
1816                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1817                                        permille / 10, permille % 10, baselen, base);
1818                                if (!dir->cumulative)
1819                                        return 0;
1820                        }
1821                }
1822        }
1823        return this_dir;
1824}
1825
1826static int dirstat_compare(const void *_a, const void *_b)
1827{
1828        const struct dirstat_file *a = _a;
1829        const struct dirstat_file *b = _b;
1830        return strcmp(a->name, b->name);
1831}
1832
1833static void show_dirstat(struct diff_options *options)
1834{
1835        int i;
1836        unsigned long changed;
1837        struct dirstat_dir dir;
1838        struct diff_queue_struct *q = &diff_queued_diff;
1839
1840        dir.files = NULL;
1841        dir.alloc = 0;
1842        dir.nr = 0;
1843        dir.permille = options->dirstat_permille;
1844        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1845
1846        changed = 0;
1847        for (i = 0; i < q->nr; i++) {
1848                struct diff_filepair *p = q->queue[i];
1849                const char *name;
1850                unsigned long copied, added, damage;
1851                int content_changed;
1852
1853                name = p->two->path ? p->two->path : p->one->path;
1854
1855                if (p->one->sha1_valid && p->two->sha1_valid)
1856                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1857                else
1858                        content_changed = 1;
1859
1860                if (!content_changed) {
1861                        /*
1862                         * The SHA1 has not changed, so pre-/post-content is
1863                         * identical. We can therefore skip looking at the
1864                         * file contents altogether.
1865                         */
1866                        damage = 0;
1867                        goto found_damage;
1868                }
1869
1870                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1871                        /*
1872                         * In --dirstat-by-file mode, we don't really need to
1873                         * look at the actual file contents at all.
1874                         * The fact that the SHA1 changed is enough for us to
1875                         * add this file to the list of results
1876                         * (with each file contributing equal damage).
1877                         */
1878                        damage = 1;
1879                        goto found_damage;
1880                }
1881
1882                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1883                        diff_populate_filespec(p->one, 0);
1884                        diff_populate_filespec(p->two, 0);
1885                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1886                                               &copied, &added);
1887                        diff_free_filespec_data(p->one);
1888                        diff_free_filespec_data(p->two);
1889                } else if (DIFF_FILE_VALID(p->one)) {
1890                        diff_populate_filespec(p->one, 1);
1891                        copied = added = 0;
1892                        diff_free_filespec_data(p->one);
1893                } else if (DIFF_FILE_VALID(p->two)) {
1894                        diff_populate_filespec(p->two, 1);
1895                        copied = 0;
1896                        added = p->two->size;
1897                        diff_free_filespec_data(p->two);
1898                } else
1899                        continue;
1900
1901                /*
1902                 * Original minus copied is the removed material,
1903                 * added is the new material.  They are both damages
1904                 * made to the preimage.
1905                 * If the resulting damage is zero, we know that
1906                 * diffcore_count_changes() considers the two entries to
1907                 * be identical, but since content_changed is true, we
1908                 * know that there must have been _some_ kind of change,
1909                 * so we force all entries to have damage > 0.
1910                 */
1911                damage = (p->one->size - copied) + added;
1912                if (!damage)
1913                        damage = 1;
1914
1915found_damage:
1916                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1917                dir.files[dir.nr].name = name;
1918                dir.files[dir.nr].changed = damage;
1919                changed += damage;
1920                dir.nr++;
1921        }
1922
1923        /* This can happen even with many files, if everything was renames */
1924        if (!changed)
1925                return;
1926
1927        /* Show all directories with more than x% of the changes */
1928        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1929        gather_dirstat(options, &dir, changed, "", 0);
1930}
1931
1932static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1933{
1934        int i;
1935        unsigned long changed;
1936        struct dirstat_dir dir;
1937
1938        if (data->nr == 0)
1939                return;
1940
1941        dir.files = NULL;
1942        dir.alloc = 0;
1943        dir.nr = 0;
1944        dir.permille = options->dirstat_permille;
1945        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1946
1947        changed = 0;
1948        for (i = 0; i < data->nr; i++) {
1949                struct diffstat_file *file = data->files[i];
1950                unsigned long damage = file->added + file->deleted;
1951                if (file->is_binary)
1952                        /*
1953                         * binary files counts bytes, not lines. Must find some
1954                         * way to normalize binary bytes vs. textual lines.
1955                         * The following heuristic assumes that there are 64
1956                         * bytes per "line".
1957                         * This is stupid and ugly, but very cheap...
1958                         */
1959                        damage = (damage + 63) / 64;
1960                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1961                dir.files[dir.nr].name = file->name;
1962                dir.files[dir.nr].changed = damage;
1963                changed += damage;
1964                dir.nr++;
1965        }
1966
1967        /* This can happen even with many files, if everything was renames */
1968        if (!changed)
1969                return;
1970
1971        /* Show all directories with more than x% of the changes */
1972        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1973        gather_dirstat(options, &dir, changed, "", 0);
1974}
1975
1976static void free_diffstat_info(struct diffstat_t *diffstat)
1977{
1978        int i;
1979        for (i = 0; i < diffstat->nr; i++) {
1980                struct diffstat_file *f = diffstat->files[i];
1981                if (f->name != f->print_name)
1982                        free(f->print_name);
1983                free(f->name);
1984                free(f->from_name);
1985                free(f);
1986        }
1987        free(diffstat->files);
1988}
1989
1990struct checkdiff_t {
1991        const char *filename;
1992        int lineno;
1993        int conflict_marker_size;
1994        struct diff_options *o;
1995        unsigned ws_rule;
1996        unsigned status;
1997};
1998
1999static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2000{
2001        char firstchar;
2002        int cnt;
2003
2004        if (len < marker_size + 1)
2005                return 0;
2006        firstchar = line[0];
2007        switch (firstchar) {
2008        case '=': case '>': case '<': case '|':
2009                break;
2010        default:
2011                return 0;
2012        }
2013        for (cnt = 1; cnt < marker_size; cnt++)
2014                if (line[cnt] != firstchar)
2015                        return 0;
2016        /* line[1] thru line[marker_size-1] are same as firstchar */
2017        if (len < marker_size + 1 || !isspace(line[marker_size]))
2018                return 0;
2019        return 1;
2020}
2021
2022static void checkdiff_consume(void *priv, char *line, unsigned long len)
2023{
2024        struct checkdiff_t *data = priv;
2025        int marker_size = data->conflict_marker_size;
2026        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2027        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2028        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2029        char *err;
2030        char *line_prefix = "";
2031        struct strbuf *msgbuf;
2032
2033        assert(data->o);
2034        if (data->o->output_prefix) {
2035                msgbuf = data->o->output_prefix(data->o,
2036                        data->o->output_prefix_data);
2037                line_prefix = msgbuf->buf;
2038        }
2039
2040        if (line[0] == '+') {
2041                unsigned bad;
2042                data->lineno++;
2043                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2044                        data->status |= 1;
2045                        fprintf(data->o->file,
2046                                "%s%s:%d: leftover conflict marker\n",
2047                                line_prefix, data->filename, data->lineno);
2048                }
2049                bad = ws_check(line + 1, len - 1, data->ws_rule);
2050                if (!bad)
2051                        return;
2052                data->status |= bad;
2053                err = whitespace_error_string(bad);
2054                fprintf(data->o->file, "%s%s:%d: %s.\n",
2055                        line_prefix, data->filename, data->lineno, err);
2056                free(err);
2057                emit_line(data->o, set, reset, line, 1);
2058                ws_check_emit(line + 1, len - 1, data->ws_rule,
2059                              data->o->file, set, reset, ws);
2060        } else if (line[0] == ' ') {
2061                data->lineno++;
2062        } else if (line[0] == '@') {
2063                char *plus = strchr(line, '+');
2064                if (plus)
2065                        data->lineno = strtol(plus, NULL, 10) - 1;
2066                else
2067                        die("invalid diff");
2068        }
2069}
2070
2071static unsigned char *deflate_it(char *data,
2072                                 unsigned long size,
2073                                 unsigned long *result_size)
2074{
2075        int bound;
2076        unsigned char *deflated;
2077        git_zstream stream;
2078
2079        memset(&stream, 0, sizeof(stream));
2080        git_deflate_init(&stream, zlib_compression_level);
2081        bound = git_deflate_bound(&stream, size);
2082        deflated = xmalloc(bound);
2083        stream.next_out = deflated;
2084        stream.avail_out = bound;
2085
2086        stream.next_in = (unsigned char *)data;
2087        stream.avail_in = size;
2088        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2089                ; /* nothing */
2090        git_deflate_end(&stream);
2091        *result_size = stream.total_out;
2092        return deflated;
2093}
2094
2095static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2096{
2097        void *cp;
2098        void *delta;
2099        void *deflated;
2100        void *data;
2101        unsigned long orig_size;
2102        unsigned long delta_size;
2103        unsigned long deflate_size;
2104        unsigned long data_size;
2105
2106        /* We could do deflated delta, or we could do just deflated two,
2107         * whichever is smaller.
2108         */
2109        delta = NULL;
2110        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2111        if (one->size && two->size) {
2112                delta = diff_delta(one->ptr, one->size,
2113                                   two->ptr, two->size,
2114                                   &delta_size, deflate_size);
2115                if (delta) {
2116                        void *to_free = delta;
2117                        orig_size = delta_size;
2118                        delta = deflate_it(delta, delta_size, &delta_size);
2119                        free(to_free);
2120                }
2121        }
2122
2123        if (delta && delta_size < deflate_size) {
2124                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2125                free(deflated);
2126                data = delta;
2127                data_size = delta_size;
2128        }
2129        else {
2130                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2131                free(delta);
2132                data = deflated;
2133                data_size = deflate_size;
2134        }
2135
2136        /* emit data encoded in base85 */
2137        cp = data;
2138        while (data_size) {
2139                int bytes = (52 < data_size) ? 52 : data_size;
2140                char line[70];
2141                data_size -= bytes;
2142                if (bytes <= 26)
2143                        line[0] = bytes + 'A' - 1;
2144                else
2145                        line[0] = bytes - 26 + 'a' - 1;
2146                encode_85(line + 1, cp, bytes);
2147                cp = (char *) cp + bytes;
2148                fprintf(file, "%s", prefix);
2149                fputs(line, file);
2150                fputc('\n', file);
2151        }
2152        fprintf(file, "%s\n", prefix);
2153        free(data);
2154}
2155
2156static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2157{
2158        fprintf(file, "%sGIT binary patch\n", prefix);
2159        emit_binary_diff_body(file, one, two, prefix);
2160        emit_binary_diff_body(file, two, one, prefix);
2161}
2162
2163int diff_filespec_is_binary(struct diff_filespec *one)
2164{
2165        if (one->is_binary == -1) {
2166                diff_filespec_load_driver(one);
2167                if (one->driver->binary != -1)
2168                        one->is_binary = one->driver->binary;
2169                else {
2170                        if (!one->data && DIFF_FILE_VALID(one))
2171                                diff_populate_filespec(one, 0);
2172                        if (one->data)
2173                                one->is_binary = buffer_is_binary(one->data,
2174                                                one->size);
2175                        if (one->is_binary == -1)
2176                                one->is_binary = 0;
2177                }
2178        }
2179        return one->is_binary;
2180}
2181
2182static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2183{
2184        diff_filespec_load_driver(one);
2185        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2186}
2187
2188void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2189{
2190        if (!options->a_prefix)
2191                options->a_prefix = a;
2192        if (!options->b_prefix)
2193                options->b_prefix = b;
2194}
2195
2196struct userdiff_driver *get_textconv(struct diff_filespec *one)
2197{
2198        if (!DIFF_FILE_VALID(one))
2199                return NULL;
2200
2201        diff_filespec_load_driver(one);
2202        return userdiff_get_textconv(one->driver);
2203}
2204
2205static void builtin_diff(const char *name_a,
2206                         const char *name_b,
2207                         struct diff_filespec *one,
2208                         struct diff_filespec *two,
2209                         const char *xfrm_msg,
2210                         int must_show_header,
2211                         struct diff_options *o,
2212                         int complete_rewrite)
2213{
2214        mmfile_t mf1, mf2;
2215        const char *lbl[2];
2216        char *a_one, *b_two;
2217        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2218        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2219        const char *a_prefix, *b_prefix;
2220        struct userdiff_driver *textconv_one = NULL;
2221        struct userdiff_driver *textconv_two = NULL;
2222        struct strbuf header = STRBUF_INIT;
2223        struct strbuf *msgbuf;
2224        char *line_prefix = "";
2225
2226        if (o->output_prefix) {
2227                msgbuf = o->output_prefix(o, o->output_prefix_data);
2228                line_prefix = msgbuf->buf;
2229        }
2230
2231        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2232                        (!one->mode || S_ISGITLINK(one->mode)) &&
2233                        (!two->mode || S_ISGITLINK(two->mode))) {
2234                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2235                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2236                show_submodule_summary(o->file, one ? one->path : two->path,
2237                                one->sha1, two->sha1, two->dirty_submodule,
2238                                del, add, reset);
2239                return;
2240        }
2241
2242        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2243                textconv_one = get_textconv(one);
2244                textconv_two = get_textconv(two);
2245        }
2246
2247        diff_set_mnemonic_prefix(o, "a/", "b/");
2248        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2249                a_prefix = o->b_prefix;
2250                b_prefix = o->a_prefix;
2251        } else {
2252                a_prefix = o->a_prefix;
2253                b_prefix = o->b_prefix;
2254        }
2255
2256        /* Never use a non-valid filename anywhere if at all possible */
2257        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2258        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2259
2260        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2261        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2262        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2263        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2264        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2265        if (lbl[0][0] == '/') {
2266                /* /dev/null */
2267                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2268                if (xfrm_msg)
2269                        strbuf_addstr(&header, xfrm_msg);
2270                must_show_header = 1;
2271        }
2272        else if (lbl[1][0] == '/') {
2273                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2274                if (xfrm_msg)
2275                        strbuf_addstr(&header, xfrm_msg);
2276                must_show_header = 1;
2277        }
2278        else {
2279                if (one->mode != two->mode) {
2280                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2281                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2282                        must_show_header = 1;
2283                }
2284                if (xfrm_msg)
2285                        strbuf_addstr(&header, xfrm_msg);
2286
2287                /*
2288                 * we do not run diff between different kind
2289                 * of objects.
2290                 */
2291                if ((one->mode ^ two->mode) & S_IFMT)
2292                        goto free_ab_and_return;
2293                if (complete_rewrite &&
2294                    (textconv_one || !diff_filespec_is_binary(one)) &&
2295                    (textconv_two || !diff_filespec_is_binary(two))) {
2296                        fprintf(o->file, "%s", header.buf);
2297                        strbuf_reset(&header);
2298                        emit_rewrite_diff(name_a, name_b, one, two,
2299                                                textconv_one, textconv_two, o);
2300                        o->found_changes = 1;
2301                        goto free_ab_and_return;
2302                }
2303        }
2304
2305        if (o->irreversible_delete && lbl[1][0] == '/') {
2306                fprintf(o->file, "%s", header.buf);
2307                strbuf_reset(&header);
2308                goto free_ab_and_return;
2309        } else if (!DIFF_OPT_TST(o, TEXT) &&
2310            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2311              (!textconv_two && diff_filespec_is_binary(two)) )) {
2312                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2313                        die("unable to read files to diff");
2314                /* Quite common confusing case */
2315                if (mf1.size == mf2.size &&
2316                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2317                        if (must_show_header)
2318                                fprintf(o->file, "%s", header.buf);
2319                        goto free_ab_and_return;
2320                }
2321                fprintf(o->file, "%s", header.buf);
2322                strbuf_reset(&header);
2323                if (DIFF_OPT_TST(o, BINARY))
2324                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2325                else
2326                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2327                                line_prefix, lbl[0], lbl[1]);
2328                o->found_changes = 1;
2329        } else {
2330                /* Crazy xdl interfaces.. */
2331                const char *diffopts = getenv("GIT_DIFF_OPTS");
2332                xpparam_t xpp;
2333                xdemitconf_t xecfg;
2334                struct emit_callback ecbdata;
2335                const struct userdiff_funcname *pe;
2336
2337                if (must_show_header) {
2338                        fprintf(o->file, "%s", header.buf);
2339                        strbuf_reset(&header);
2340                }
2341
2342                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2343                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2344
2345                pe = diff_funcname_pattern(one);
2346                if (!pe)
2347                        pe = diff_funcname_pattern(two);
2348
2349                memset(&xpp, 0, sizeof(xpp));
2350                memset(&xecfg, 0, sizeof(xecfg));
2351                memset(&ecbdata, 0, sizeof(ecbdata));
2352                ecbdata.label_path = lbl;
2353                ecbdata.color_diff = want_color(o->use_color);
2354                ecbdata.found_changesp = &o->found_changes;
2355                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2356                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2357                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2358                ecbdata.opt = o;
2359                ecbdata.header = header.len ? &header : NULL;
2360                xpp.flags = o->xdl_opts;
2361                xecfg.ctxlen = o->context;
2362                xecfg.interhunkctxlen = o->interhunkcontext;
2363                xecfg.flags = XDL_EMIT_FUNCNAMES;
2364                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2365                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2366                if (pe)
2367                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2368                if (!diffopts)
2369                        ;
2370                else if (!prefixcmp(diffopts, "--unified="))
2371                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2372                else if (!prefixcmp(diffopts, "-u"))
2373                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2374                if (o->word_diff)
2375                        init_diff_words_data(&ecbdata, o, one, two);
2376                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2377                              &xpp, &xecfg);
2378                if (o->word_diff)
2379                        free_diff_words_data(&ecbdata);
2380                if (textconv_one)
2381                        free(mf1.ptr);
2382                if (textconv_two)
2383                        free(mf2.ptr);
2384                xdiff_clear_find_func(&xecfg);
2385        }
2386
2387 free_ab_and_return:
2388        strbuf_release(&header);
2389        diff_free_filespec_data(one);
2390        diff_free_filespec_data(two);
2391        free(a_one);
2392        free(b_two);
2393        return;
2394}
2395
2396static void builtin_diffstat(const char *name_a, const char *name_b,
2397                             struct diff_filespec *one,
2398                             struct diff_filespec *two,
2399                             struct diffstat_t *diffstat,
2400                             struct diff_options *o,
2401                             int complete_rewrite)
2402{
2403        mmfile_t mf1, mf2;
2404        struct diffstat_file *data;
2405        int same_contents;
2406
2407        data = diffstat_add(diffstat, name_a, name_b);
2408
2409        if (!one || !two) {
2410                data->is_unmerged = 1;
2411                return;
2412        }
2413
2414        same_contents = !hashcmp(one->sha1, two->sha1);
2415
2416        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2417                data->is_binary = 1;
2418                if (same_contents) {
2419                        data->added = 0;
2420                        data->deleted = 0;
2421                } else {
2422                        data->added = diff_filespec_size(two);
2423                        data->deleted = diff_filespec_size(one);
2424                }
2425        }
2426
2427        else if (complete_rewrite) {
2428                diff_populate_filespec(one, 0);
2429                diff_populate_filespec(two, 0);
2430                data->deleted = count_lines(one->data, one->size);
2431                data->added = count_lines(two->data, two->size);
2432        }
2433
2434        else if (!same_contents) {
2435                /* Crazy xdl interfaces.. */
2436                xpparam_t xpp;
2437                xdemitconf_t xecfg;
2438
2439                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2440                        die("unable to read files to diff");
2441
2442                memset(&xpp, 0, sizeof(xpp));
2443                memset(&xecfg, 0, sizeof(xecfg));
2444                xpp.flags = o->xdl_opts;
2445                xecfg.ctxlen = o->context;
2446                xecfg.interhunkctxlen = o->interhunkcontext;
2447                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2448                              &xpp, &xecfg);
2449        }
2450
2451        diff_free_filespec_data(one);
2452        diff_free_filespec_data(two);
2453}
2454
2455static void builtin_checkdiff(const char *name_a, const char *name_b,
2456                              const char *attr_path,
2457                              struct diff_filespec *one,
2458                              struct diff_filespec *two,
2459                              struct diff_options *o)
2460{
2461        mmfile_t mf1, mf2;
2462        struct checkdiff_t data;
2463
2464        if (!two)
2465                return;
2466
2467        memset(&data, 0, sizeof(data));
2468        data.filename = name_b ? name_b : name_a;
2469        data.lineno = 0;
2470        data.o = o;
2471        data.ws_rule = whitespace_rule(attr_path);
2472        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2473
2474        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2475                die("unable to read files to diff");
2476
2477        /*
2478         * All the other codepaths check both sides, but not checking
2479         * the "old" side here is deliberate.  We are checking the newly
2480         * introduced changes, and as long as the "new" side is text, we
2481         * can and should check what it introduces.
2482         */
2483        if (diff_filespec_is_binary(two))
2484                goto free_and_return;
2485        else {
2486                /* Crazy xdl interfaces.. */
2487                xpparam_t xpp;
2488                xdemitconf_t xecfg;
2489
2490                memset(&xpp, 0, sizeof(xpp));
2491                memset(&xecfg, 0, sizeof(xecfg));
2492                xecfg.ctxlen = 1; /* at least one context line */
2493                xpp.flags = 0;
2494                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2495                              &xpp, &xecfg);
2496
2497                if (data.ws_rule & WS_BLANK_AT_EOF) {
2498                        struct emit_callback ecbdata;
2499                        int blank_at_eof;
2500
2501                        ecbdata.ws_rule = data.ws_rule;
2502                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2503                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2504
2505                        if (blank_at_eof) {
2506                                static char *err;
2507                                if (!err)
2508                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2509                                fprintf(o->file, "%s:%d: %s.\n",
2510                                        data.filename, blank_at_eof, err);
2511                                data.status = 1; /* report errors */
2512                        }
2513                }
2514        }
2515 free_and_return:
2516        diff_free_filespec_data(one);
2517        diff_free_filespec_data(two);
2518        if (data.status)
2519                DIFF_OPT_SET(o, CHECK_FAILED);
2520}
2521
2522struct diff_filespec *alloc_filespec(const char *path)
2523{
2524        int namelen = strlen(path);
2525        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2526
2527        memset(spec, 0, sizeof(*spec));
2528        spec->path = (char *)(spec + 1);
2529        memcpy(spec->path, path, namelen+1);
2530        spec->count = 1;
2531        spec->is_binary = -1;
2532        return spec;
2533}
2534
2535void free_filespec(struct diff_filespec *spec)
2536{
2537        if (!--spec->count) {
2538                diff_free_filespec_data(spec);
2539                free(spec);
2540        }
2541}
2542
2543void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2544                   unsigned short mode)
2545{
2546        if (mode) {
2547                spec->mode = canon_mode(mode);
2548                hashcpy(spec->sha1, sha1);
2549                spec->sha1_valid = !is_null_sha1(sha1);
2550        }
2551}
2552
2553/*
2554 * Given a name and sha1 pair, if the index tells us the file in
2555 * the work tree has that object contents, return true, so that
2556 * prepare_temp_file() does not have to inflate and extract.
2557 */
2558static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2559{
2560        struct cache_entry *ce;
2561        struct stat st;
2562        int pos, len;
2563
2564        /*
2565         * We do not read the cache ourselves here, because the
2566         * benchmark with my previous version that always reads cache
2567         * shows that it makes things worse for diff-tree comparing
2568         * two linux-2.6 kernel trees in an already checked out work
2569         * tree.  This is because most diff-tree comparisons deal with
2570         * only a small number of files, while reading the cache is
2571         * expensive for a large project, and its cost outweighs the
2572         * savings we get by not inflating the object to a temporary
2573         * file.  Practically, this code only helps when we are used
2574         * by diff-cache --cached, which does read the cache before
2575         * calling us.
2576         */
2577        if (!active_cache)
2578                return 0;
2579
2580        /* We want to avoid the working directory if our caller
2581         * doesn't need the data in a normal file, this system
2582         * is rather slow with its stat/open/mmap/close syscalls,
2583         * and the object is contained in a pack file.  The pack
2584         * is probably already open and will be faster to obtain
2585         * the data through than the working directory.  Loose
2586         * objects however would tend to be slower as they need
2587         * to be individually opened and inflated.
2588         */
2589        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2590                return 0;
2591
2592        len = strlen(name);
2593        pos = cache_name_pos(name, len);
2594        if (pos < 0)
2595                return 0;
2596        ce = active_cache[pos];
2597
2598        /*
2599         * This is not the sha1 we are looking for, or
2600         * unreusable because it is not a regular file.
2601         */
2602        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2603                return 0;
2604
2605        /*
2606         * If ce is marked as "assume unchanged", there is no
2607         * guarantee that work tree matches what we are looking for.
2608         */
2609        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2610                return 0;
2611
2612        /*
2613         * If ce matches the file in the work tree, we can reuse it.
2614         */
2615        if (ce_uptodate(ce) ||
2616            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2617                return 1;
2618
2619        return 0;
2620}
2621
2622static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2623{
2624        int len;
2625        char *data = xmalloc(100), *dirty = "";
2626
2627        /* Are we looking at the work tree? */
2628        if (s->dirty_submodule)
2629                dirty = "-dirty";
2630
2631        len = snprintf(data, 100,
2632                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2633        s->data = data;
2634        s->size = len;
2635        s->should_free = 1;
2636        if (size_only) {
2637                s->data = NULL;
2638                free(data);
2639        }
2640        return 0;
2641}
2642
2643/*
2644 * While doing rename detection and pickaxe operation, we may need to
2645 * grab the data for the blob (or file) for our own in-core comparison.
2646 * diff_filespec has data and size fields for this purpose.
2647 */
2648int diff_populate_filespec(struct diff_filespec *s, int size_only)
2649{
2650        int err = 0;
2651        if (!DIFF_FILE_VALID(s))
2652                die("internal error: asking to populate invalid file.");
2653        if (S_ISDIR(s->mode))
2654                return -1;
2655
2656        if (s->data)
2657                return 0;
2658
2659        if (size_only && 0 < s->size)
2660                return 0;
2661
2662        if (S_ISGITLINK(s->mode))
2663                return diff_populate_gitlink(s, size_only);
2664
2665        if (!s->sha1_valid ||
2666            reuse_worktree_file(s->path, s->sha1, 0)) {
2667                struct strbuf buf = STRBUF_INIT;
2668                struct stat st;
2669                int fd;
2670
2671                if (lstat(s->path, &st) < 0) {
2672                        if (errno == ENOENT) {
2673                        err_empty:
2674                                err = -1;
2675                        empty:
2676                                s->data = (char *)"";
2677                                s->size = 0;
2678                                return err;
2679                        }
2680                }
2681                s->size = xsize_t(st.st_size);
2682                if (!s->size)
2683                        goto empty;
2684                if (S_ISLNK(st.st_mode)) {
2685                        struct strbuf sb = STRBUF_INIT;
2686
2687                        if (strbuf_readlink(&sb, s->path, s->size))
2688                                goto err_empty;
2689                        s->size = sb.len;
2690                        s->data = strbuf_detach(&sb, NULL);
2691                        s->should_free = 1;
2692                        return 0;
2693                }
2694                if (size_only)
2695                        return 0;
2696                fd = open(s->path, O_RDONLY);
2697                if (fd < 0)
2698                        goto err_empty;
2699                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2700                close(fd);
2701                s->should_munmap = 1;
2702
2703                /*
2704                 * Convert from working tree format to canonical git format
2705                 */
2706                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2707                        size_t size = 0;
2708                        munmap(s->data, s->size);
2709                        s->should_munmap = 0;
2710                        s->data = strbuf_detach(&buf, &size);
2711                        s->size = size;
2712                        s->should_free = 1;
2713                }
2714        }
2715        else {
2716                enum object_type type;
2717                if (size_only) {
2718                        type = sha1_object_info(s->sha1, &s->size);
2719                        if (type < 0)
2720                                die("unable to read %s", sha1_to_hex(s->sha1));
2721                } else {
2722                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2723                        if (!s->data)
2724                                die("unable to read %s", sha1_to_hex(s->sha1));
2725                        s->should_free = 1;
2726                }
2727        }
2728        return 0;
2729}
2730
2731void diff_free_filespec_blob(struct diff_filespec *s)
2732{
2733        if (s->should_free)
2734                free(s->data);
2735        else if (s->should_munmap)
2736                munmap(s->data, s->size);
2737
2738        if (s->should_free || s->should_munmap) {
2739                s->should_free = s->should_munmap = 0;
2740                s->data = NULL;
2741        }
2742}
2743
2744void diff_free_filespec_data(struct diff_filespec *s)
2745{
2746        diff_free_filespec_blob(s);
2747        free(s->cnt_data);
2748        s->cnt_data = NULL;
2749}
2750
2751static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2752                           void *blob,
2753                           unsigned long size,
2754                           const unsigned char *sha1,
2755                           int mode)
2756{
2757        int fd;
2758        struct strbuf buf = STRBUF_INIT;
2759        struct strbuf template = STRBUF_INIT;
2760        char *path_dup = xstrdup(path);
2761        const char *base = basename(path_dup);
2762
2763        /* Generate "XXXXXX_basename.ext" */
2764        strbuf_addstr(&template, "XXXXXX_");
2765        strbuf_addstr(&template, base);
2766
2767        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2768                        strlen(base) + 1);
2769        if (fd < 0)
2770                die_errno("unable to create temp-file");
2771        if (convert_to_working_tree(path,
2772                        (const char *)blob, (size_t)size, &buf)) {
2773                blob = buf.buf;
2774                size = buf.len;
2775        }
2776        if (write_in_full(fd, blob, size) != size)
2777                die_errno("unable to write temp-file");
2778        close(fd);
2779        temp->name = temp->tmp_path;
2780        strcpy(temp->hex, sha1_to_hex(sha1));
2781        temp->hex[40] = 0;
2782        sprintf(temp->mode, "%06o", mode);
2783        strbuf_release(&buf);
2784        strbuf_release(&template);
2785        free(path_dup);
2786}
2787
2788static struct diff_tempfile *prepare_temp_file(const char *name,
2789                struct diff_filespec *one)
2790{
2791        struct diff_tempfile *temp = claim_diff_tempfile();
2792
2793        if (!DIFF_FILE_VALID(one)) {
2794        not_a_valid_file:
2795                /* A '-' entry produces this for file-2, and
2796                 * a '+' entry produces this for file-1.
2797                 */
2798                temp->name = "/dev/null";
2799                strcpy(temp->hex, ".");
2800                strcpy(temp->mode, ".");
2801                return temp;
2802        }
2803
2804        if (!remove_tempfile_installed) {
2805                atexit(remove_tempfile);
2806                sigchain_push_common(remove_tempfile_on_signal);
2807                remove_tempfile_installed = 1;
2808        }
2809
2810        if (!one->sha1_valid ||
2811            reuse_worktree_file(name, one->sha1, 1)) {
2812                struct stat st;
2813                if (lstat(name, &st) < 0) {
2814                        if (errno == ENOENT)
2815                                goto not_a_valid_file;
2816                        die_errno("stat(%s)", name);
2817                }
2818                if (S_ISLNK(st.st_mode)) {
2819                        struct strbuf sb = STRBUF_INIT;
2820                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2821                                die_errno("readlink(%s)", name);
2822                        prep_temp_blob(name, temp, sb.buf, sb.len,
2823                                       (one->sha1_valid ?
2824                                        one->sha1 : null_sha1),
2825                                       (one->sha1_valid ?
2826                                        one->mode : S_IFLNK));
2827                        strbuf_release(&sb);
2828                }
2829                else {
2830                        /* we can borrow from the file in the work tree */
2831                        temp->name = name;
2832                        if (!one->sha1_valid)
2833                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2834                        else
2835                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2836                        /* Even though we may sometimes borrow the
2837                         * contents from the work tree, we always want
2838                         * one->mode.  mode is trustworthy even when
2839                         * !(one->sha1_valid), as long as
2840                         * DIFF_FILE_VALID(one).
2841                         */
2842                        sprintf(temp->mode, "%06o", one->mode);
2843                }
2844                return temp;
2845        }
2846        else {
2847                if (diff_populate_filespec(one, 0))
2848                        die("cannot read data blob for %s", one->path);
2849                prep_temp_blob(name, temp, one->data, one->size,
2850                               one->sha1, one->mode);
2851        }
2852        return temp;
2853}
2854
2855/* An external diff command takes:
2856 *
2857 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2858 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2859 *
2860 */
2861static void run_external_diff(const char *pgm,
2862                              const char *name,
2863                              const char *other,
2864                              struct diff_filespec *one,
2865                              struct diff_filespec *two,
2866                              const char *xfrm_msg,
2867                              int complete_rewrite)
2868{
2869        const char *spawn_arg[10];
2870        int retval;
2871        const char **arg = &spawn_arg[0];
2872
2873        if (one && two) {
2874                struct diff_tempfile *temp_one, *temp_two;
2875                const char *othername = (other ? other : name);
2876                temp_one = prepare_temp_file(name, one);
2877                temp_two = prepare_temp_file(othername, two);
2878                *arg++ = pgm;
2879                *arg++ = name;
2880                *arg++ = temp_one->name;
2881                *arg++ = temp_one->hex;
2882                *arg++ = temp_one->mode;
2883                *arg++ = temp_two->name;
2884                *arg++ = temp_two->hex;
2885                *arg++ = temp_two->mode;
2886                if (other) {
2887                        *arg++ = other;
2888                        *arg++ = xfrm_msg;
2889                }
2890        } else {
2891                *arg++ = pgm;
2892                *arg++ = name;
2893        }
2894        *arg = NULL;
2895        fflush(NULL);
2896        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2897        remove_tempfile();
2898        if (retval) {
2899                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2900                exit(1);
2901        }
2902}
2903
2904static int similarity_index(struct diff_filepair *p)
2905{
2906        return p->score * 100 / MAX_SCORE;
2907}
2908
2909static void fill_metainfo(struct strbuf *msg,
2910                          const char *name,
2911                          const char *other,
2912                          struct diff_filespec *one,
2913                          struct diff_filespec *two,
2914                          struct diff_options *o,
2915                          struct diff_filepair *p,
2916                          int *must_show_header,
2917                          int use_color)
2918{
2919        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2920        const char *reset = diff_get_color(use_color, DIFF_RESET);
2921        struct strbuf *msgbuf;
2922        char *line_prefix = "";
2923
2924        *must_show_header = 1;
2925        if (o->output_prefix) {
2926                msgbuf = o->output_prefix(o, o->output_prefix_data);
2927                line_prefix = msgbuf->buf;
2928        }
2929        strbuf_init(msg, PATH_MAX * 2 + 300);
2930        switch (p->status) {
2931        case DIFF_STATUS_COPIED:
2932                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2933                            line_prefix, set, similarity_index(p));
2934                strbuf_addf(msg, "%s\n%s%scopy from ",
2935                            reset,  line_prefix, set);
2936                quote_c_style(name, msg, NULL, 0);
2937                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2938                quote_c_style(other, msg, NULL, 0);
2939                strbuf_addf(msg, "%s\n", reset);
2940                break;
2941        case DIFF_STATUS_RENAMED:
2942                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2943                            line_prefix, set, similarity_index(p));
2944                strbuf_addf(msg, "%s\n%s%srename from ",
2945                            reset, line_prefix, set);
2946                quote_c_style(name, msg, NULL, 0);
2947                strbuf_addf(msg, "%s\n%s%srename to ",
2948                            reset, line_prefix, set);
2949                quote_c_style(other, msg, NULL, 0);
2950                strbuf_addf(msg, "%s\n", reset);
2951                break;
2952        case DIFF_STATUS_MODIFIED:
2953                if (p->score) {
2954                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2955                                    line_prefix,
2956                                    set, similarity_index(p), reset);
2957                        break;
2958                }
2959                /* fallthru */
2960        default:
2961                *must_show_header = 0;
2962        }
2963        if (one && two && hashcmp(one->sha1, two->sha1)) {
2964                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2965
2966                if (DIFF_OPT_TST(o, BINARY)) {
2967                        mmfile_t mf;
2968                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2969                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2970                                abbrev = 40;
2971                }
2972                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2973                            find_unique_abbrev(one->sha1, abbrev));
2974                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2975                if (one->mode == two->mode)
2976                        strbuf_addf(msg, " %06o", one->mode);
2977                strbuf_addf(msg, "%s\n", reset);
2978        }
2979}
2980
2981static void run_diff_cmd(const char *pgm,
2982                         const char *name,
2983                         const char *other,
2984                         const char *attr_path,
2985                         struct diff_filespec *one,
2986                         struct diff_filespec *two,
2987                         struct strbuf *msg,
2988                         struct diff_options *o,
2989                         struct diff_filepair *p)
2990{
2991        const char *xfrm_msg = NULL;
2992        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2993        int must_show_header = 0;
2994
2995        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2996                pgm = NULL;
2997        else {
2998                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2999                if (drv && drv->external)
3000                        pgm = drv->external;
3001        }
3002
3003        if (msg) {
3004                /*
3005                 * don't use colors when the header is intended for an
3006                 * external diff driver
3007                 */
3008                fill_metainfo(msg, name, other, one, two, o, p,
3009                              &must_show_header,
3010                              want_color(o->use_color) && !pgm);
3011                xfrm_msg = msg->len ? msg->buf : NULL;
3012        }
3013
3014        if (pgm) {
3015                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3016                                  complete_rewrite);
3017                return;
3018        }
3019        if (one && two)
3020                builtin_diff(name, other ? other : name,
3021                             one, two, xfrm_msg, must_show_header,
3022                             o, complete_rewrite);
3023        else
3024                fprintf(o->file, "* Unmerged path %s\n", name);
3025}
3026
3027static void diff_fill_sha1_info(struct diff_filespec *one)
3028{
3029        if (DIFF_FILE_VALID(one)) {
3030                if (!one->sha1_valid) {
3031                        struct stat st;
3032                        if (one->is_stdin) {
3033                                hashcpy(one->sha1, null_sha1);
3034                                return;
3035                        }
3036                        if (lstat(one->path, &st) < 0)
3037                                die_errno("stat '%s'", one->path);
3038                        if (index_path(one->sha1, one->path, &st, 0))
3039                                die("cannot hash %s", one->path);
3040                }
3041        }
3042        else
3043                hashclr(one->sha1);
3044}
3045
3046static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3047{
3048        /* Strip the prefix but do not molest /dev/null and absolute paths */
3049        if (*namep && **namep != '/') {
3050                *namep += prefix_length;
3051                if (**namep == '/')
3052                        ++*namep;
3053        }
3054        if (*otherp && **otherp != '/') {
3055                *otherp += prefix_length;
3056                if (**otherp == '/')
3057                        ++*otherp;
3058        }
3059}
3060
3061static void run_diff(struct diff_filepair *p, struct diff_options *o)
3062{
3063        const char *pgm = external_diff();
3064        struct strbuf msg;
3065        struct diff_filespec *one = p->one;
3066        struct diff_filespec *two = p->two;
3067        const char *name;
3068        const char *other;
3069        const char *attr_path;
3070
3071        name  = p->one->path;
3072        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3073        attr_path = name;
3074        if (o->prefix_length)
3075                strip_prefix(o->prefix_length, &name, &other);
3076
3077        if (DIFF_PAIR_UNMERGED(p)) {
3078                run_diff_cmd(pgm, name, NULL, attr_path,
3079                             NULL, NULL, NULL, o, p);
3080                return;
3081        }
3082
3083        diff_fill_sha1_info(one);
3084        diff_fill_sha1_info(two);
3085
3086        if (!pgm &&
3087            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3088            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3089                /*
3090                 * a filepair that changes between file and symlink
3091                 * needs to be split into deletion and creation.
3092                 */
3093                struct diff_filespec *null = alloc_filespec(two->path);
3094                run_diff_cmd(NULL, name, other, attr_path,
3095                             one, null, &msg, o, p);
3096                free(null);
3097                strbuf_release(&msg);
3098
3099                null = alloc_filespec(one->path);
3100                run_diff_cmd(NULL, name, other, attr_path,
3101                             null, two, &msg, o, p);
3102                free(null);
3103        }
3104        else
3105                run_diff_cmd(pgm, name, other, attr_path,
3106                             one, two, &msg, o, p);
3107
3108        strbuf_release(&msg);
3109}
3110
3111static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3112                         struct diffstat_t *diffstat)
3113{
3114        const char *name;
3115        const char *other;
3116        int complete_rewrite = 0;
3117
3118        if (DIFF_PAIR_UNMERGED(p)) {
3119                /* unmerged */
3120                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
3121                return;
3122        }
3123
3124        name = p->one->path;
3125        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3126
3127        if (o->prefix_length)
3128                strip_prefix(o->prefix_length, &name, &other);
3129
3130        diff_fill_sha1_info(p->one);
3131        diff_fill_sha1_info(p->two);
3132
3133        if (p->status == DIFF_STATUS_MODIFIED && p->score)
3134                complete_rewrite = 1;
3135        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
3136}
3137
3138static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3139{
3140        const char *name;
3141        const char *other;
3142        const char *attr_path;
3143
3144        if (DIFF_PAIR_UNMERGED(p)) {
3145                /* unmerged */
3146                return;
3147        }
3148
3149        name = p->one->path;
3150        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3151        attr_path = other ? other : name;
3152
3153        if (o->prefix_length)
3154                strip_prefix(o->prefix_length, &name, &other);
3155
3156        diff_fill_sha1_info(p->one);
3157        diff_fill_sha1_info(p->two);
3158
3159        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3160}
3161
3162void diff_setup(struct diff_options *options)
3163{
3164        memcpy(options, &default_diff_options, sizeof(*options));
3165
3166        options->file = stdout;
3167
3168        options->line_termination = '\n';
3169        options->break_opt = -1;
3170        options->rename_limit = -1;
3171        options->dirstat_permille = diff_dirstat_permille_default;
3172        options->context = 3;
3173        DIFF_OPT_SET(options, RENAME_EMPTY);
3174
3175        options->change = diff_change;
3176        options->add_remove = diff_addremove;
3177        options->use_color = diff_use_color_default;
3178        options->detect_rename = diff_detect_rename_default;
3179
3180        if (diff_no_prefix) {
3181                options->a_prefix = options->b_prefix = "";
3182        } else if (!diff_mnemonic_prefix) {
3183                options->a_prefix = "a/";
3184                options->b_prefix = "b/";
3185        }
3186}
3187
3188int diff_setup_done(struct diff_options *options)
3189{
3190        int count = 0;
3191
3192        if (options->output_format & DIFF_FORMAT_NAME)
3193                count++;
3194        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3195                count++;
3196        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3197                count++;
3198        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3199                count++;
3200        if (count > 1)
3201                die("--name-only, --name-status, --check and -s are mutually exclusive");
3202
3203        /*
3204         * Most of the time we can say "there are changes"
3205         * only by checking if there are changed paths, but
3206         * --ignore-whitespace* options force us to look
3207         * inside contents.
3208         */
3209
3210        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3211            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3212            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3213                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3214        else
3215                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3216
3217        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3218                options->detect_rename = DIFF_DETECT_COPY;
3219
3220        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3221                options->prefix = NULL;
3222        if (options->prefix)
3223                options->prefix_length = strlen(options->prefix);
3224        else
3225                options->prefix_length = 0;
3226
3227        if (options->output_format & (DIFF_FORMAT_NAME |
3228                                      DIFF_FORMAT_NAME_STATUS |
3229                                      DIFF_FORMAT_CHECKDIFF |
3230                                      DIFF_FORMAT_NO_OUTPUT))
3231                options->output_format &= ~(DIFF_FORMAT_RAW |
3232                                            DIFF_FORMAT_NUMSTAT |
3233                                            DIFF_FORMAT_DIFFSTAT |
3234                                            DIFF_FORMAT_SHORTSTAT |
3235                                            DIFF_FORMAT_DIRSTAT |
3236                                            DIFF_FORMAT_SUMMARY |
3237                                            DIFF_FORMAT_PATCH);
3238
3239        /*
3240         * These cases always need recursive; we do not drop caller-supplied
3241         * recursive bits for other formats here.
3242         */
3243        if (options->output_format & (DIFF_FORMAT_PATCH |
3244                                      DIFF_FORMAT_NUMSTAT |
3245                                      DIFF_FORMAT_DIFFSTAT |
3246                                      DIFF_FORMAT_SHORTSTAT |
3247                                      DIFF_FORMAT_DIRSTAT |
3248                                      DIFF_FORMAT_SUMMARY |
3249                                      DIFF_FORMAT_CHECKDIFF))
3250                DIFF_OPT_SET(options, RECURSIVE);
3251        /*
3252         * Also pickaxe would not work very well if you do not say recursive
3253         */
3254        if (options->pickaxe)
3255                DIFF_OPT_SET(options, RECURSIVE);
3256        /*
3257         * When patches are generated, submodules diffed against the work tree
3258         * must be checked for dirtiness too so it can be shown in the output
3259         */
3260        if (options->output_format & DIFF_FORMAT_PATCH)
3261                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3262
3263        if (options->detect_rename && options->rename_limit < 0)
3264                options->rename_limit = diff_rename_limit_default;
3265        if (options->setup & DIFF_SETUP_USE_CACHE) {
3266                if (!active_cache)
3267                        /* read-cache does not die even when it fails
3268                         * so it is safe for us to do this here.  Also
3269                         * it does not smudge active_cache or active_nr
3270                         * when it fails, so we do not have to worry about
3271                         * cleaning it up ourselves either.
3272                         */
3273                        read_cache();
3274        }
3275        if (options->abbrev <= 0 || 40 < options->abbrev)
3276                options->abbrev = 40; /* full */
3277
3278        /*
3279         * It does not make sense to show the first hit we happened
3280         * to have found.  It does not make sense not to return with
3281         * exit code in such a case either.
3282         */
3283        if (DIFF_OPT_TST(options, QUICK)) {
3284                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3285                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3286        }
3287
3288        return 0;
3289}
3290
3291static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3292{
3293        char c, *eq;
3294        int len;
3295
3296        if (*arg != '-')
3297                return 0;
3298        c = *++arg;
3299        if (!c)
3300                return 0;
3301        if (c == arg_short) {
3302                c = *++arg;
3303                if (!c)
3304                        return 1;
3305                if (val && isdigit(c)) {
3306                        char *end;
3307                        int n = strtoul(arg, &end, 10);
3308                        if (*end)
3309                                return 0;
3310                        *val = n;
3311                        return 1;
3312                }
3313                return 0;
3314        }
3315        if (c != '-')
3316                return 0;
3317        arg++;
3318        eq = strchr(arg, '=');
3319        if (eq)
3320                len = eq - arg;
3321        else
3322                len = strlen(arg);
3323        if (!len || strncmp(arg, arg_long, len))
3324                return 0;
3325        if (eq) {
3326                int n;
3327                char *end;
3328                if (!isdigit(*++eq))
3329                        return 0;
3330                n = strtoul(eq, &end, 10);
3331                if (*end)
3332                        return 0;
3333                *val = n;
3334        }
3335        return 1;
3336}
3337
3338static int diff_scoreopt_parse(const char *opt);
3339
3340static inline int short_opt(char opt, const char **argv,
3341                            const char **optarg)
3342{
3343        const char *arg = argv[0];
3344        if (arg[0] != '-' || arg[1] != opt)
3345                return 0;
3346        if (arg[2] != '\0') {
3347                *optarg = arg + 2;
3348                return 1;
3349        }
3350        if (!argv[1])
3351                die("Option '%c' requires a value", opt);
3352        *optarg = argv[1];
3353        return 2;
3354}
3355
3356int parse_long_opt(const char *opt, const char **argv,
3357                   const char **optarg)
3358{
3359        const char *arg = argv[0];
3360        if (arg[0] != '-' || arg[1] != '-')
3361                return 0;
3362        arg += strlen("--");
3363        if (prefixcmp(arg, opt))
3364                return 0;
3365        arg += strlen(opt);
3366        if (*arg == '=') { /* sticked form: --option=value */
3367                *optarg = arg + 1;
3368                return 1;
3369        }
3370        if (*arg != '\0')
3371                return 0;
3372        /* separate form: --option value */
3373        if (!argv[1])
3374                die("Option '--%s' requires a value", opt);
3375        *optarg = argv[1];
3376        return 2;
3377}
3378
3379static int stat_opt(struct diff_options *options, const char **av)
3380{
3381        const char *arg = av[0];
3382        char *end;
3383        int width = options->stat_width;
3384        int name_width = options->stat_name_width;
3385        int graph_width = options->stat_graph_width;
3386        int count = options->stat_count;
3387        int argcount = 1;
3388
3389        arg += strlen("--stat");
3390        end = (char *)arg;
3391
3392        switch (*arg) {
3393        case '-':
3394                if (!prefixcmp(arg, "-width")) {
3395                        arg += strlen("-width");
3396                        if (*arg == '=')
3397                                width = strtoul(arg + 1, &end, 10);
3398                        else if (!*arg && !av[1])
3399                                die("Option '--stat-width' requires a value");
3400                        else if (!*arg) {
3401                                width = strtoul(av[1], &end, 10);
3402                                argcount = 2;
3403                        }
3404                } else if (!prefixcmp(arg, "-name-width")) {
3405                        arg += strlen("-name-width");
3406                        if (*arg == '=')
3407                                name_width = strtoul(arg + 1, &end, 10);
3408                        else if (!*arg && !av[1])
3409                                die("Option '--stat-name-width' requires a value");
3410                        else if (!*arg) {
3411                                name_width = strtoul(av[1], &end, 10);
3412                                argcount = 2;
3413                        }
3414                } else if (!prefixcmp(arg, "-graph-width")) {
3415                        arg += strlen("-graph-width");
3416                        if (*arg == '=')
3417                                graph_width = strtoul(arg + 1, &end, 10);
3418                        else if (!*arg && !av[1])
3419                                die("Option '--stat-graph-width' requires a value");
3420                        else if (!*arg) {
3421                                graph_width = strtoul(av[1], &end, 10);
3422                                argcount = 2;
3423                        }
3424                } else if (!prefixcmp(arg, "-count")) {
3425                        arg += strlen("-count");
3426                        if (*arg == '=')
3427                                count = strtoul(arg + 1, &end, 10);
3428                        else if (!*arg && !av[1])
3429                                die("Option '--stat-count' requires a value");
3430                        else if (!*arg) {
3431                                count = strtoul(av[1], &end, 10);
3432                                argcount = 2;
3433                        }
3434                }
3435                break;
3436        case '=':
3437                width = strtoul(arg+1, &end, 10);
3438                if (*end == ',')
3439                        name_width = strtoul(end+1, &end, 10);
3440                if (*end == ',')
3441                        count = strtoul(end+1, &end, 10);
3442        }
3443
3444        /* Important! This checks all the error cases! */
3445        if (*end)
3446                return 0;
3447        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3448        options->stat_name_width = name_width;
3449        options->stat_graph_width = graph_width;
3450        options->stat_width = width;
3451        options->stat_count = count;
3452        return argcount;
3453}
3454
3455static int parse_dirstat_opt(struct diff_options *options, const char *params)
3456{
3457        struct strbuf errmsg = STRBUF_INIT;
3458        if (parse_dirstat_params(options, params, &errmsg))
3459                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3460                    errmsg.buf);
3461        strbuf_release(&errmsg);
3462        /*
3463         * The caller knows a dirstat-related option is given from the command
3464         * line; allow it to say "return this_function();"
3465         */
3466        options->output_format |= DIFF_FORMAT_DIRSTAT;
3467        return 1;
3468}
3469
3470int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3471{
3472        const char *arg = av[0];
3473        const char *optarg;
3474        int argcount;
3475
3476        /* Output format options */
3477        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3478                options->output_format |= DIFF_FORMAT_PATCH;
3479        else if (opt_arg(arg, 'U', "unified", &options->context))
3480                options->output_format |= DIFF_FORMAT_PATCH;
3481        else if (!strcmp(arg, "--raw"))
3482                options->output_format |= DIFF_FORMAT_RAW;
3483        else if (!strcmp(arg, "--patch-with-raw"))
3484                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3485        else if (!strcmp(arg, "--numstat"))
3486                options->output_format |= DIFF_FORMAT_NUMSTAT;
3487        else if (!strcmp(arg, "--shortstat"))
3488                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3489        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3490                return parse_dirstat_opt(options, "");
3491        else if (!prefixcmp(arg, "-X"))
3492                return parse_dirstat_opt(options, arg + 2);
3493        else if (!prefixcmp(arg, "--dirstat="))
3494                return parse_dirstat_opt(options, arg + 10);
3495        else if (!strcmp(arg, "--cumulative"))
3496                return parse_dirstat_opt(options, "cumulative");
3497        else if (!strcmp(arg, "--dirstat-by-file"))
3498                return parse_dirstat_opt(options, "files");
3499        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3500                parse_dirstat_opt(options, "files");
3501                return parse_dirstat_opt(options, arg + 18);
3502        }
3503        else if (!strcmp(arg, "--check"))
3504                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3505        else if (!strcmp(arg, "--summary"))
3506                options->output_format |= DIFF_FORMAT_SUMMARY;
3507        else if (!strcmp(arg, "--patch-with-stat"))
3508                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3509        else if (!strcmp(arg, "--name-only"))
3510                options->output_format |= DIFF_FORMAT_NAME;
3511        else if (!strcmp(arg, "--name-status"))
3512                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3513        else if (!strcmp(arg, "-s"))
3514                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3515        else if (!prefixcmp(arg, "--stat"))
3516                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3517                return stat_opt(options, av);
3518
3519        /* renames options */
3520        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3521                 !strcmp(arg, "--break-rewrites")) {
3522                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3523                        return error("invalid argument to -B: %s", arg+2);
3524        }
3525        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3526                 !strcmp(arg, "--find-renames")) {
3527                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3528                        return error("invalid argument to -M: %s", arg+2);
3529                options->detect_rename = DIFF_DETECT_RENAME;
3530        }
3531        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3532                options->irreversible_delete = 1;
3533        }
3534        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3535                 !strcmp(arg, "--find-copies")) {
3536                if (options->detect_rename == DIFF_DETECT_COPY)
3537                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3538                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3539                        return error("invalid argument to -C: %s", arg+2);
3540                options->detect_rename = DIFF_DETECT_COPY;
3541        }
3542        else if (!strcmp(arg, "--no-renames"))
3543                options->detect_rename = 0;
3544        else if (!strcmp(arg, "--rename-empty"))
3545                DIFF_OPT_SET(options, RENAME_EMPTY);
3546        else if (!strcmp(arg, "--no-rename-empty"))
3547                DIFF_OPT_CLR(options, RENAME_EMPTY);
3548        else if (!strcmp(arg, "--relative"))
3549                DIFF_OPT_SET(options, RELATIVE_NAME);
3550        else if (!prefixcmp(arg, "--relative=")) {
3551                DIFF_OPT_SET(options, RELATIVE_NAME);
3552                options->prefix = arg + 11;
3553        }
3554
3555        /* xdiff options */
3556        else if (!strcmp(arg, "--minimal"))
3557                DIFF_XDL_SET(options, NEED_MINIMAL);
3558        else if (!strcmp(arg, "--no-minimal"))
3559                DIFF_XDL_CLR(options, NEED_MINIMAL);
3560        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3561                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3562        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3563                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3564        else if (!strcmp(arg, "--ignore-space-at-eol"))
3565                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3566        else if (!strcmp(arg, "--patience"))
3567                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3568        else if (!strcmp(arg, "--histogram"))
3569                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3570
3571        /* flags options */
3572        else if (!strcmp(arg, "--binary")) {
3573                options->output_format |= DIFF_FORMAT_PATCH;
3574                DIFF_OPT_SET(options, BINARY);
3575        }
3576        else if (!strcmp(arg, "--full-index"))
3577                DIFF_OPT_SET(options, FULL_INDEX);
3578        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3579                DIFF_OPT_SET(options, TEXT);
3580        else if (!strcmp(arg, "-R"))
3581                DIFF_OPT_SET(options, REVERSE_DIFF);
3582        else if (!strcmp(arg, "--find-copies-harder"))
3583                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3584        else if (!strcmp(arg, "--follow"))
3585                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3586        else if (!strcmp(arg, "--color"))
3587                options->use_color = 1;
3588        else if (!prefixcmp(arg, "--color=")) {
3589                int value = git_config_colorbool(NULL, arg+8);
3590                if (value < 0)
3591                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3592                options->use_color = value;
3593        }
3594        else if (!strcmp(arg, "--no-color"))
3595                options->use_color = 0;
3596        else if (!strcmp(arg, "--color-words")) {
3597                options->use_color = 1;
3598                options->word_diff = DIFF_WORDS_COLOR;
3599        }
3600        else if (!prefixcmp(arg, "--color-words=")) {
3601                options->use_color = 1;
3602                options->word_diff = DIFF_WORDS_COLOR;
3603                options->word_regex = arg + 14;
3604        }
3605        else if (!strcmp(arg, "--word-diff")) {
3606                if (options->word_diff == DIFF_WORDS_NONE)
3607                        options->word_diff = DIFF_WORDS_PLAIN;
3608        }
3609        else if (!prefixcmp(arg, "--word-diff=")) {
3610                const char *type = arg + 12;
3611                if (!strcmp(type, "plain"))
3612                        options->word_diff = DIFF_WORDS_PLAIN;
3613                else if (!strcmp(type, "color")) {
3614                        options->use_color = 1;
3615                        options->word_diff = DIFF_WORDS_COLOR;
3616                }
3617                else if (!strcmp(type, "porcelain"))
3618                        options->word_diff = DIFF_WORDS_PORCELAIN;
3619                else if (!strcmp(type, "none"))
3620                        options->word_diff = DIFF_WORDS_NONE;
3621                else
3622                        die("bad --word-diff argument: %s", type);
3623        }
3624        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3625                if (options->word_diff == DIFF_WORDS_NONE)
3626                        options->word_diff = DIFF_WORDS_PLAIN;
3627                options->word_regex = optarg;
3628                return argcount;
3629        }
3630        else if (!strcmp(arg, "--exit-code"))
3631                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3632        else if (!strcmp(arg, "--quiet"))
3633                DIFF_OPT_SET(options, QUICK);
3634        else if (!strcmp(arg, "--ext-diff"))
3635                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3636        else if (!strcmp(arg, "--no-ext-diff"))
3637                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3638        else if (!strcmp(arg, "--textconv"))
3639                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3640        else if (!strcmp(arg, "--no-textconv"))
3641                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3642        else if (!strcmp(arg, "--ignore-submodules")) {
3643                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3644                handle_ignore_submodules_arg(options, "all");
3645        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3646                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3647                handle_ignore_submodules_arg(options, arg + 20);
3648        } else if (!strcmp(arg, "--submodule"))
3649                DIFF_OPT_SET(options, SUBMODULE_LOG);
3650        else if (!prefixcmp(arg, "--submodule=")) {
3651                if (!strcmp(arg + 12, "log"))
3652                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3653        }
3654
3655        /* misc options */
3656        else if (!strcmp(arg, "-z"))
3657                options->line_termination = 0;
3658        else if ((argcount = short_opt('l', av, &optarg))) {
3659                options->rename_limit = strtoul(optarg, NULL, 10);
3660                return argcount;
3661        }
3662        else if ((argcount = short_opt('S', av, &optarg))) {
3663                options->pickaxe = optarg;
3664                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3665                return argcount;
3666        } else if ((argcount = short_opt('G', av, &optarg))) {
3667                options->pickaxe = optarg;
3668                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3669                return argcount;
3670        }
3671        else if (!strcmp(arg, "--pickaxe-all"))
3672                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3673        else if (!strcmp(arg, "--pickaxe-regex"))
3674                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3675        else if ((argcount = short_opt('O', av, &optarg))) {
3676                options->orderfile = optarg;
3677                return argcount;
3678        }
3679        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3680                options->filter = optarg;
3681                return argcount;
3682        }
3683        else if (!strcmp(arg, "--abbrev"))
3684                options->abbrev = DEFAULT_ABBREV;
3685        else if (!prefixcmp(arg, "--abbrev=")) {
3686                options->abbrev = strtoul(arg + 9, NULL, 10);
3687                if (options->abbrev < MINIMUM_ABBREV)
3688                        options->abbrev = MINIMUM_ABBREV;
3689                else if (40 < options->abbrev)
3690                        options->abbrev = 40;
3691        }
3692        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3693                options->a_prefix = optarg;
3694                return argcount;
3695        }
3696        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3697                options->b_prefix = optarg;
3698                return argcount;
3699        }
3700        else if (!strcmp(arg, "--no-prefix"))
3701                options->a_prefix = options->b_prefix = "";
3702        else if (opt_arg(arg, '\0', "inter-hunk-context",
3703                         &options->interhunkcontext))
3704                ;
3705        else if (!strcmp(arg, "-W"))
3706                DIFF_OPT_SET(options, FUNCCONTEXT);
3707        else if (!strcmp(arg, "--function-context"))
3708                DIFF_OPT_SET(options, FUNCCONTEXT);
3709        else if (!strcmp(arg, "--no-function-context"))
3710                DIFF_OPT_CLR(options, FUNCCONTEXT);
3711        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3712                options->file = fopen(optarg, "w");
3713                if (!options->file)
3714                        die_errno("Could not open '%s'", optarg);
3715                options->close_file = 1;
3716                return argcount;
3717        } else
3718                return 0;
3719        return 1;
3720}
3721
3722int parse_rename_score(const char **cp_p)
3723{
3724        unsigned long num, scale;
3725        int ch, dot;
3726        const char *cp = *cp_p;
3727
3728        num = 0;
3729        scale = 1;
3730        dot = 0;
3731        for (;;) {
3732                ch = *cp;
3733                if ( !dot && ch == '.' ) {
3734                        scale = 1;
3735                        dot = 1;
3736                } else if ( ch == '%' ) {
3737                        scale = dot ? scale*100 : 100;
3738                        cp++;   /* % is always at the end */
3739                        break;
3740                } else if ( ch >= '0' && ch <= '9' ) {
3741                        if ( scale < 100000 ) {
3742                                scale *= 10;
3743                                num = (num*10) + (ch-'0');
3744                        }
3745                } else {
3746                        break;
3747                }
3748                cp++;
3749        }
3750        *cp_p = cp;
3751
3752        /* user says num divided by scale and we say internally that
3753         * is MAX_SCORE * num / scale.
3754         */
3755        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3756}
3757
3758static int diff_scoreopt_parse(const char *opt)
3759{
3760        int opt1, opt2, cmd;
3761
3762        if (*opt++ != '-')
3763                return -1;
3764        cmd = *opt++;
3765        if (cmd == '-') {
3766                /* convert the long-form arguments into short-form versions */
3767                if (!prefixcmp(opt, "break-rewrites")) {
3768                        opt += strlen("break-rewrites");
3769                        if (*opt == 0 || *opt++ == '=')
3770                                cmd = 'B';
3771                } else if (!prefixcmp(opt, "find-copies")) {
3772                        opt += strlen("find-copies");
3773                        if (*opt == 0 || *opt++ == '=')
3774                                cmd = 'C';
3775                } else if (!prefixcmp(opt, "find-renames")) {
3776                        opt += strlen("find-renames");
3777                        if (*opt == 0 || *opt++ == '=')
3778                                cmd = 'M';
3779                }
3780        }
3781        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3782                return -1; /* that is not a -M, -C nor -B option */
3783
3784        opt1 = parse_rename_score(&opt);
3785        if (cmd != 'B')
3786                opt2 = 0;
3787        else {
3788                if (*opt == 0)
3789                        opt2 = 0;
3790                else if (*opt != '/')
3791                        return -1; /* we expect -B80/99 or -B80 */
3792                else {
3793                        opt++;
3794                        opt2 = parse_rename_score(&opt);
3795                }
3796        }
3797        if (*opt != 0)
3798                return -1;
3799        return opt1 | (opt2 << 16);
3800}
3801
3802struct diff_queue_struct diff_queued_diff;
3803
3804void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3805{
3806        if (queue->alloc <= queue->nr) {
3807                queue->alloc = alloc_nr(queue->alloc);
3808                queue->queue = xrealloc(queue->queue,
3809                                        sizeof(dp) * queue->alloc);
3810        }
3811        queue->queue[queue->nr++] = dp;
3812}
3813
3814struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3815                                 struct diff_filespec *one,
3816                                 struct diff_filespec *two)
3817{
3818        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3819        dp->one = one;
3820        dp->two = two;
3821        if (queue)
3822                diff_q(queue, dp);
3823        return dp;
3824}
3825
3826void diff_free_filepair(struct diff_filepair *p)
3827{
3828        free_filespec(p->one);
3829        free_filespec(p->two);
3830        free(p);
3831}
3832
3833/* This is different from find_unique_abbrev() in that
3834 * it stuffs the result with dots for alignment.
3835 */
3836const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3837{
3838        int abblen;
3839        const char *abbrev;
3840        if (len == 40)
3841                return sha1_to_hex(sha1);
3842
3843        abbrev = find_unique_abbrev(sha1, len);
3844        abblen = strlen(abbrev);
3845        if (abblen < 37) {
3846                static char hex[41];
3847                if (len < abblen && abblen <= len + 2)
3848                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3849                else
3850                        sprintf(hex, "%s...", abbrev);
3851                return hex;
3852        }
3853        return sha1_to_hex(sha1);
3854}
3855
3856static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3857{
3858        int line_termination = opt->line_termination;
3859        int inter_name_termination = line_termination ? '\t' : '\0';
3860        if (opt->output_prefix) {
3861                struct strbuf *msg = NULL;
3862                msg = opt->output_prefix(opt, opt->output_prefix_data);
3863                fprintf(opt->file, "%s", msg->buf);
3864        }
3865
3866        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3867                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3868                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3869                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3870        }
3871        if (p->score) {
3872                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3873                        inter_name_termination);
3874        } else {
3875                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3876        }
3877
3878        if (p->status == DIFF_STATUS_COPIED ||
3879            p->status == DIFF_STATUS_RENAMED) {
3880                const char *name_a, *name_b;
3881                name_a = p->one->path;
3882                name_b = p->two->path;
3883                strip_prefix(opt->prefix_length, &name_a, &name_b);
3884                write_name_quoted(name_a, opt->file, inter_name_termination);
3885                write_name_quoted(name_b, opt->file, line_termination);
3886        } else {
3887                const char *name_a, *name_b;
3888                name_a = p->one->mode ? p->one->path : p->two->path;
3889                name_b = NULL;
3890                strip_prefix(opt->prefix_length, &name_a, &name_b);
3891                write_name_quoted(name_a, opt->file, line_termination);
3892        }
3893}
3894
3895int diff_unmodified_pair(struct diff_filepair *p)
3896{
3897        /* This function is written stricter than necessary to support
3898         * the currently implemented transformers, but the idea is to
3899         * let transformers to produce diff_filepairs any way they want,
3900         * and filter and clean them up here before producing the output.
3901         */
3902        struct diff_filespec *one = p->one, *two = p->two;
3903
3904        if (DIFF_PAIR_UNMERGED(p))
3905                return 0; /* unmerged is interesting */
3906
3907        /* deletion, addition, mode or type change
3908         * and rename are all interesting.
3909         */
3910        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3911            DIFF_PAIR_MODE_CHANGED(p) ||
3912            strcmp(one->path, two->path))
3913                return 0;
3914
3915        /* both are valid and point at the same path.  that is, we are
3916         * dealing with a change.
3917         */
3918        if (one->sha1_valid && two->sha1_valid &&
3919            !hashcmp(one->sha1, two->sha1) &&
3920            !one->dirty_submodule && !two->dirty_submodule)
3921                return 1; /* no change */
3922        if (!one->sha1_valid && !two->sha1_valid)
3923                return 1; /* both look at the same file on the filesystem. */
3924        return 0;
3925}
3926
3927static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3928{
3929        if (diff_unmodified_pair(p))
3930                return;
3931
3932        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3933            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3934                return; /* no tree diffs in patch format */
3935
3936        run_diff(p, o);
3937}
3938
3939static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3940                            struct diffstat_t *diffstat)
3941{
3942        if (diff_unmodified_pair(p))
3943                return;
3944
3945        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3946            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3947                return; /* no useful stat for tree diffs */
3948
3949        run_diffstat(p, o, diffstat);
3950}
3951
3952static void diff_flush_checkdiff(struct diff_filepair *p,
3953                struct diff_options *o)
3954{
3955        if (diff_unmodified_pair(p))
3956                return;
3957
3958        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3959            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3960                return; /* nothing to check in tree diffs */
3961
3962        run_checkdiff(p, o);
3963}
3964
3965int diff_queue_is_empty(void)
3966{
3967        struct diff_queue_struct *q = &diff_queued_diff;
3968        int i;
3969        for (i = 0; i < q->nr; i++)
3970                if (!diff_unmodified_pair(q->queue[i]))
3971                        return 0;
3972        return 1;
3973}
3974
3975#if DIFF_DEBUG
3976void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3977{
3978        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3979                x, one ? one : "",
3980                s->path,
3981                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3982                s->mode,
3983                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3984        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3985                x, one ? one : "",
3986                s->size, s->xfrm_flags);
3987}
3988
3989void diff_debug_filepair(const struct diff_filepair *p, int i)
3990{
3991        diff_debug_filespec(p->one, i, "one");
3992        diff_debug_filespec(p->two, i, "two");
3993        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3994                p->score, p->status ? p->status : '?',
3995                p->one->rename_used, p->broken_pair);
3996}
3997
3998void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3999{
4000        int i;
4001        if (msg)
4002                fprintf(stderr, "%s\n", msg);
4003        fprintf(stderr, "q->nr = %d\n", q->nr);
4004        for (i = 0; i < q->nr; i++) {
4005                struct diff_filepair *p = q->queue[i];
4006                diff_debug_filepair(p, i);
4007        }
4008}
4009#endif
4010
4011static void diff_resolve_rename_copy(void)
4012{
4013        int i;
4014        struct diff_filepair *p;
4015        struct diff_queue_struct *q = &diff_queued_diff;
4016
4017        diff_debug_queue("resolve-rename-copy", q);
4018
4019        for (i = 0; i < q->nr; i++) {
4020                p = q->queue[i];
4021                p->status = 0; /* undecided */
4022                if (DIFF_PAIR_UNMERGED(p))
4023                        p->status = DIFF_STATUS_UNMERGED;
4024                else if (!DIFF_FILE_VALID(p->one))
4025                        p->status = DIFF_STATUS_ADDED;
4026                else if (!DIFF_FILE_VALID(p->two))
4027                        p->status = DIFF_STATUS_DELETED;
4028                else if (DIFF_PAIR_TYPE_CHANGED(p))
4029                        p->status = DIFF_STATUS_TYPE_CHANGED;
4030
4031                /* from this point on, we are dealing with a pair
4032                 * whose both sides are valid and of the same type, i.e.
4033                 * either in-place edit or rename/copy edit.
4034                 */
4035                else if (DIFF_PAIR_RENAME(p)) {
4036                        /*
4037                         * A rename might have re-connected a broken
4038                         * pair up, causing the pathnames to be the
4039                         * same again. If so, that's not a rename at
4040                         * all, just a modification..
4041                         *
4042                         * Otherwise, see if this source was used for
4043                         * multiple renames, in which case we decrement
4044                         * the count, and call it a copy.
4045                         */
4046                        if (!strcmp(p->one->path, p->two->path))
4047                                p->status = DIFF_STATUS_MODIFIED;
4048                        else if (--p->one->rename_used > 0)
4049                                p->status = DIFF_STATUS_COPIED;
4050                        else
4051                                p->status = DIFF_STATUS_RENAMED;
4052                }
4053                else if (hashcmp(p->one->sha1, p->two->sha1) ||
4054                         p->one->mode != p->two->mode ||
4055                         p->one->dirty_submodule ||
4056                         p->two->dirty_submodule ||
4057                         is_null_sha1(p->one->sha1))
4058                        p->status = DIFF_STATUS_MODIFIED;
4059                else {
4060                        /* This is a "no-change" entry and should not
4061                         * happen anymore, but prepare for broken callers.
4062                         */
4063                        error("feeding unmodified %s to diffcore",
4064                              p->one->path);
4065                        p->status = DIFF_STATUS_UNKNOWN;
4066                }
4067        }
4068        diff_debug_queue("resolve-rename-copy done", q);
4069}
4070
4071static int check_pair_status(struct diff_filepair *p)
4072{
4073        switch (p->status) {
4074        case DIFF_STATUS_UNKNOWN:
4075                return 0;
4076        case 0:
4077                die("internal error in diff-resolve-rename-copy");
4078        default:
4079                return 1;
4080        }
4081}
4082
4083static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4084{
4085        int fmt = opt->output_format;
4086
4087        if (fmt & DIFF_FORMAT_CHECKDIFF)
4088                diff_flush_checkdiff(p, opt);
4089        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4090                diff_flush_raw(p, opt);
4091        else if (fmt & DIFF_FORMAT_NAME) {
4092                const char *name_a, *name_b;
4093                name_a = p->two->path;
4094                name_b = NULL;
4095                strip_prefix(opt->prefix_length, &name_a, &name_b);
4096                write_name_quoted(name_a, opt->file, opt->line_termination);
4097        }
4098}
4099
4100static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4101{
4102        if (fs->mode)
4103                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4104        else
4105                fprintf(file, " %s ", newdelete);
4106        write_name_quoted(fs->path, file, '\n');
4107}
4108
4109
4110static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4111                const char *line_prefix)
4112{
4113        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4114                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4115                        p->two->mode, show_name ? ' ' : '\n');
4116                if (show_name) {
4117                        write_name_quoted(p->two->path, file, '\n');
4118                }
4119        }
4120}
4121
4122static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4123                        const char *line_prefix)
4124{
4125        char *names = pprint_rename(p->one->path, p->two->path);
4126
4127        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4128        free(names);
4129        show_mode_change(file, p, 0, line_prefix);
4130}
4131
4132static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4133{
4134        FILE *file = opt->file;
4135        char *line_prefix = "";
4136
4137        if (opt->output_prefix) {
4138                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
4139                line_prefix = buf->buf;
4140        }
4141
4142        switch(p->status) {
4143        case DIFF_STATUS_DELETED:
4144                fputs(line_prefix, file);
4145                show_file_mode_name(file, "delete", p->one);
4146                break;
4147        case DIFF_STATUS_ADDED:
4148                fputs(line_prefix, file);
4149                show_file_mode_name(file, "create", p->two);
4150                break;
4151        case DIFF_STATUS_COPIED:
4152                fputs(line_prefix, file);
4153                show_rename_copy(file, "copy", p, line_prefix);
4154                break;
4155        case DIFF_STATUS_RENAMED:
4156                fputs(line_prefix, file);
4157                show_rename_copy(file, "rename", p, line_prefix);
4158                break;
4159        default:
4160                if (p->score) {
4161                        fprintf(file, "%s rewrite ", line_prefix);
4162                        write_name_quoted(p->two->path, file, ' ');
4163                        fprintf(file, "(%d%%)\n", similarity_index(p));
4164                }
4165                show_mode_change(file, p, !p->score, line_prefix);
4166                break;
4167        }
4168}
4169
4170struct patch_id_t {
4171        git_SHA_CTX *ctx;
4172        int patchlen;
4173};
4174
4175static int remove_space(char *line, int len)
4176{
4177        int i;
4178        char *dst = line;
4179        unsigned char c;
4180
4181        for (i = 0; i < len; i++)
4182                if (!isspace((c = line[i])))
4183                        *dst++ = c;
4184
4185        return dst - line;
4186}
4187
4188static void patch_id_consume(void *priv, char *line, unsigned long len)
4189{
4190        struct patch_id_t *data = priv;
4191        int new_len;
4192
4193        /* Ignore line numbers when computing the SHA1 of the patch */
4194        if (!prefixcmp(line, "@@ -"))
4195                return;
4196
4197        new_len = remove_space(line, len);
4198
4199        git_SHA1_Update(data->ctx, line, new_len);
4200        data->patchlen += new_len;
4201}
4202
4203/* returns 0 upon success, and writes result into sha1 */
4204static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4205{
4206        struct diff_queue_struct *q = &diff_queued_diff;
4207        int i;
4208        git_SHA_CTX ctx;
4209        struct patch_id_t data;
4210        char buffer[PATH_MAX * 4 + 20];
4211
4212        git_SHA1_Init(&ctx);
4213        memset(&data, 0, sizeof(struct patch_id_t));
4214        data.ctx = &ctx;
4215
4216        for (i = 0; i < q->nr; i++) {
4217                xpparam_t xpp;
4218                xdemitconf_t xecfg;
4219                mmfile_t mf1, mf2;
4220                struct diff_filepair *p = q->queue[i];
4221                int len1, len2;
4222
4223                memset(&xpp, 0, sizeof(xpp));
4224                memset(&xecfg, 0, sizeof(xecfg));
4225                if (p->status == 0)
4226                        return error("internal diff status error");
4227                if (p->status == DIFF_STATUS_UNKNOWN)
4228                        continue;
4229                if (diff_unmodified_pair(p))
4230                        continue;
4231                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4232                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4233                        continue;
4234                if (DIFF_PAIR_UNMERGED(p))
4235                        continue;
4236
4237                diff_fill_sha1_info(p->one);
4238                diff_fill_sha1_info(p->two);
4239                if (fill_mmfile(&mf1, p->one) < 0 ||
4240                                fill_mmfile(&mf2, p->two) < 0)
4241                        return error("unable to read files to diff");
4242
4243                len1 = remove_space(p->one->path, strlen(p->one->path));
4244                len2 = remove_space(p->two->path, strlen(p->two->path));
4245                if (p->one->mode == 0)
4246                        len1 = snprintf(buffer, sizeof(buffer),
4247                                        "diff--gita/%.*sb/%.*s"
4248                                        "newfilemode%06o"
4249                                        "---/dev/null"
4250                                        "+++b/%.*s",
4251                                        len1, p->one->path,
4252                                        len2, p->two->path,
4253                                        p->two->mode,
4254                                        len2, p->two->path);
4255                else if (p->two->mode == 0)
4256                        len1 = snprintf(buffer, sizeof(buffer),
4257                                        "diff--gita/%.*sb/%.*s"
4258                                        "deletedfilemode%06o"
4259                                        "---a/%.*s"
4260                                        "+++/dev/null",
4261                                        len1, p->one->path,
4262                                        len2, p->two->path,
4263                                        p->one->mode,
4264                                        len1, p->one->path);
4265                else
4266                        len1 = snprintf(buffer, sizeof(buffer),
4267                                        "diff--gita/%.*sb/%.*s"
4268                                        "---a/%.*s"
4269                                        "+++b/%.*s",
4270                                        len1, p->one->path,
4271                                        len2, p->two->path,
4272                                        len1, p->one->path,
4273                                        len2, p->two->path);
4274                git_SHA1_Update(&ctx, buffer, len1);
4275
4276                if (diff_filespec_is_binary(p->one) ||
4277                    diff_filespec_is_binary(p->two)) {
4278                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4279                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4280                        continue;
4281                }
4282
4283                xpp.flags = 0;
4284                xecfg.ctxlen = 3;
4285                xecfg.flags = 0;
4286                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4287                              &xpp, &xecfg);
4288        }
4289
4290        git_SHA1_Final(sha1, &ctx);
4291        return 0;
4292}
4293
4294int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4295{
4296        struct diff_queue_struct *q = &diff_queued_diff;
4297        int i;
4298        int result = diff_get_patch_id(options, sha1);
4299
4300        for (i = 0; i < q->nr; i++)
4301                diff_free_filepair(q->queue[i]);
4302
4303        free(q->queue);
4304        DIFF_QUEUE_CLEAR(q);
4305
4306        return result;
4307}
4308
4309static int is_summary_empty(const struct diff_queue_struct *q)
4310{
4311        int i;
4312
4313        for (i = 0; i < q->nr; i++) {
4314                const struct diff_filepair *p = q->queue[i];
4315
4316                switch (p->status) {
4317                case DIFF_STATUS_DELETED:
4318                case DIFF_STATUS_ADDED:
4319                case DIFF_STATUS_COPIED:
4320                case DIFF_STATUS_RENAMED:
4321                        return 0;
4322                default:
4323                        if (p->score)
4324                                return 0;
4325                        if (p->one->mode && p->two->mode &&
4326                            p->one->mode != p->two->mode)
4327                                return 0;
4328                        break;
4329                }
4330        }
4331        return 1;
4332}
4333
4334static const char rename_limit_warning[] =
4335"inexact rename detection was skipped due to too many files.";
4336
4337static const char degrade_cc_to_c_warning[] =
4338"only found copies from modified paths due to too many files.";
4339
4340static const char rename_limit_advice[] =
4341"you may want to set your %s variable to at least "
4342"%d and retry the command.";
4343
4344void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4345{
4346        if (degraded_cc)
4347                warning(degrade_cc_to_c_warning);
4348        else if (needed)
4349                warning(rename_limit_warning);
4350        else
4351                return;
4352        if (0 < needed && needed < 32767)
4353                warning(rename_limit_advice, varname, needed);
4354}
4355
4356void diff_flush(struct diff_options *options)
4357{
4358        struct diff_queue_struct *q = &diff_queued_diff;
4359        int i, output_format = options->output_format;
4360        int separator = 0;
4361        int dirstat_by_line = 0;
4362
4363        /*
4364         * Order: raw, stat, summary, patch
4365         * or:    name/name-status/checkdiff (other bits clear)
4366         */
4367        if (!q->nr)
4368                goto free_queue;
4369
4370        if (output_format & (DIFF_FORMAT_RAW |
4371                             DIFF_FORMAT_NAME |
4372                             DIFF_FORMAT_NAME_STATUS |
4373                             DIFF_FORMAT_CHECKDIFF)) {
4374                for (i = 0; i < q->nr; i++) {
4375                        struct diff_filepair *p = q->queue[i];
4376                        if (check_pair_status(p))
4377                                flush_one_pair(p, options);
4378                }
4379                separator++;
4380        }
4381
4382        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4383                dirstat_by_line = 1;
4384
4385        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4386            dirstat_by_line) {
4387                struct diffstat_t diffstat;
4388
4389                memset(&diffstat, 0, sizeof(struct diffstat_t));
4390                for (i = 0; i < q->nr; i++) {
4391                        struct diff_filepair *p = q->queue[i];
4392                        if (check_pair_status(p))
4393                                diff_flush_stat(p, options, &diffstat);
4394                }
4395                if (output_format & DIFF_FORMAT_NUMSTAT)
4396                        show_numstat(&diffstat, options);
4397                if (output_format & DIFF_FORMAT_DIFFSTAT)
4398                        show_stats(&diffstat, options);
4399                if (output_format & DIFF_FORMAT_SHORTSTAT)
4400                        show_shortstats(&diffstat, options);
4401                if (output_format & DIFF_FORMAT_DIRSTAT)
4402                        show_dirstat_by_line(&diffstat, options);
4403                free_diffstat_info(&diffstat);
4404                separator++;
4405        }
4406        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4407                show_dirstat(options);
4408
4409        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4410                for (i = 0; i < q->nr; i++) {
4411                        diff_summary(options, q->queue[i]);
4412                }
4413                separator++;
4414        }
4415
4416        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4417            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4418            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4419                /*
4420                 * run diff_flush_patch for the exit status. setting
4421                 * options->file to /dev/null should be safe, becaue we
4422                 * aren't supposed to produce any output anyway.
4423                 */
4424                if (options->close_file)
4425                        fclose(options->file);
4426                options->file = fopen("/dev/null", "w");
4427                if (!options->file)
4428                        die_errno("Could not open /dev/null");
4429                options->close_file = 1;
4430                for (i = 0; i < q->nr; i++) {
4431                        struct diff_filepair *p = q->queue[i];
4432                        if (check_pair_status(p))
4433                                diff_flush_patch(p, options);
4434                        if (options->found_changes)
4435                                break;
4436                }
4437        }
4438
4439        if (output_format & DIFF_FORMAT_PATCH) {
4440                if (separator) {
4441                        if (options->output_prefix) {
4442                                struct strbuf *msg = NULL;
4443                                msg = options->output_prefix(options,
4444                                        options->output_prefix_data);
4445                                fwrite(msg->buf, msg->len, 1, stdout);
4446                        }
4447                        putc(options->line_termination, options->file);
4448                        if (options->stat_sep) {
4449                                /* attach patch instead of inline */
4450                                fputs(options->stat_sep, options->file);
4451                        }
4452                }
4453
4454                for (i = 0; i < q->nr; i++) {
4455                        struct diff_filepair *p = q->queue[i];
4456                        if (check_pair_status(p))
4457                                diff_flush_patch(p, options);
4458                }
4459        }
4460
4461        if (output_format & DIFF_FORMAT_CALLBACK)
4462                options->format_callback(q, options, options->format_callback_data);
4463
4464        for (i = 0; i < q->nr; i++)
4465                diff_free_filepair(q->queue[i]);
4466free_queue:
4467        free(q->queue);
4468        DIFF_QUEUE_CLEAR(q);
4469        if (options->close_file)
4470                fclose(options->file);
4471
4472        /*
4473         * Report the content-level differences with HAS_CHANGES;
4474         * diff_addremove/diff_change does not set the bit when
4475         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4476         */
4477        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4478                if (options->found_changes)
4479                        DIFF_OPT_SET(options, HAS_CHANGES);
4480                else
4481                        DIFF_OPT_CLR(options, HAS_CHANGES);
4482        }
4483}
4484
4485static void diffcore_apply_filter(const char *filter)
4486{
4487        int i;
4488        struct diff_queue_struct *q = &diff_queued_diff;
4489        struct diff_queue_struct outq;
4490        DIFF_QUEUE_CLEAR(&outq);
4491
4492        if (!filter)
4493                return;
4494
4495        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4496                int found;
4497                for (i = found = 0; !found && i < q->nr; i++) {
4498                        struct diff_filepair *p = q->queue[i];
4499                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4500                             ((p->score &&
4501                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4502                              (!p->score &&
4503                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4504                            ((p->status != DIFF_STATUS_MODIFIED) &&
4505                             strchr(filter, p->status)))
4506                                found++;
4507                }
4508                if (found)
4509                        return;
4510
4511                /* otherwise we will clear the whole queue
4512                 * by copying the empty outq at the end of this
4513                 * function, but first clear the current entries
4514                 * in the queue.
4515                 */
4516                for (i = 0; i < q->nr; i++)
4517                        diff_free_filepair(q->queue[i]);
4518        }
4519        else {
4520                /* Only the matching ones */
4521                for (i = 0; i < q->nr; i++) {
4522                        struct diff_filepair *p = q->queue[i];
4523
4524                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4525                             ((p->score &&
4526                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4527                              (!p->score &&
4528                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4529                            ((p->status != DIFF_STATUS_MODIFIED) &&
4530                             strchr(filter, p->status)))
4531                                diff_q(&outq, p);
4532                        else
4533                                diff_free_filepair(p);
4534                }
4535        }
4536        free(q->queue);
4537        *q = outq;
4538}
4539
4540/* Check whether two filespecs with the same mode and size are identical */
4541static int diff_filespec_is_identical(struct diff_filespec *one,
4542                                      struct diff_filespec *two)
4543{
4544        if (S_ISGITLINK(one->mode))
4545                return 0;
4546        if (diff_populate_filespec(one, 0))
4547                return 0;
4548        if (diff_populate_filespec(two, 0))
4549                return 0;
4550        return !memcmp(one->data, two->data, one->size);
4551}
4552
4553static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4554{
4555        int i;
4556        struct diff_queue_struct *q = &diff_queued_diff;
4557        struct diff_queue_struct outq;
4558        DIFF_QUEUE_CLEAR(&outq);
4559
4560        for (i = 0; i < q->nr; i++) {
4561                struct diff_filepair *p = q->queue[i];
4562
4563                /*
4564                 * 1. Entries that come from stat info dirtiness
4565                 *    always have both sides (iow, not create/delete),
4566                 *    one side of the object name is unknown, with
4567                 *    the same mode and size.  Keep the ones that
4568                 *    do not match these criteria.  They have real
4569                 *    differences.
4570                 *
4571                 * 2. At this point, the file is known to be modified,
4572                 *    with the same mode and size, and the object
4573                 *    name of one side is unknown.  Need to inspect
4574                 *    the identical contents.
4575                 */
4576                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4577                    !DIFF_FILE_VALID(p->two) ||
4578                    (p->one->sha1_valid && p->two->sha1_valid) ||
4579                    (p->one->mode != p->two->mode) ||
4580                    diff_populate_filespec(p->one, 1) ||
4581                    diff_populate_filespec(p->two, 1) ||
4582                    (p->one->size != p->two->size) ||
4583                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4584                        diff_q(&outq, p);
4585                else {
4586                        /*
4587                         * The caller can subtract 1 from skip_stat_unmatch
4588                         * to determine how many paths were dirty only
4589                         * due to stat info mismatch.
4590                         */
4591                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4592                                diffopt->skip_stat_unmatch++;
4593                        diff_free_filepair(p);
4594                }
4595        }
4596        free(q->queue);
4597        *q = outq;
4598}
4599
4600static int diffnamecmp(const void *a_, const void *b_)
4601{
4602        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4603        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4604        const char *name_a, *name_b;
4605
4606        name_a = a->one ? a->one->path : a->two->path;
4607        name_b = b->one ? b->one->path : b->two->path;
4608        return strcmp(name_a, name_b);
4609}
4610
4611void diffcore_fix_diff_index(struct diff_options *options)
4612{
4613        struct diff_queue_struct *q = &diff_queued_diff;
4614        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4615}
4616
4617void diffcore_std(struct diff_options *options)
4618{
4619        if (options->skip_stat_unmatch)
4620                diffcore_skip_stat_unmatch(options);
4621        if (!options->found_follow) {
4622                /* See try_to_follow_renames() in tree-diff.c */
4623                if (options->break_opt != -1)
4624                        diffcore_break(options->break_opt);
4625                if (options->detect_rename)
4626                        diffcore_rename(options);
4627                if (options->break_opt != -1)
4628                        diffcore_merge_broken();
4629        }
4630        if (options->pickaxe)
4631                diffcore_pickaxe(options);
4632        if (options->orderfile)
4633                diffcore_order(options->orderfile);
4634        if (!options->found_follow)
4635                /* See try_to_follow_renames() in tree-diff.c */
4636                diff_resolve_rename_copy();
4637        diffcore_apply_filter(options->filter);
4638
4639        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4640                DIFF_OPT_SET(options, HAS_CHANGES);
4641        else
4642                DIFF_OPT_CLR(options, HAS_CHANGES);
4643
4644        options->found_follow = 0;
4645}
4646
4647int diff_result_code(struct diff_options *opt, int status)
4648{
4649        int result = 0;
4650
4651        diff_warn_rename_limit("diff.renamelimit",
4652                               opt->needed_rename_limit,
4653                               opt->degraded_cc_to_c);
4654        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4655            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4656                return status;
4657        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4658            DIFF_OPT_TST(opt, HAS_CHANGES))
4659                result |= 01;
4660        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4661            DIFF_OPT_TST(opt, CHECK_FAILED))
4662                result |= 02;
4663        return result;
4664}
4665
4666int diff_can_quit_early(struct diff_options *opt)
4667{
4668        return (DIFF_OPT_TST(opt, QUICK) &&
4669                !opt->filter &&
4670                DIFF_OPT_TST(opt, HAS_CHANGES));
4671}
4672
4673/*
4674 * Shall changes to this submodule be ignored?
4675 *
4676 * Submodule changes can be configured to be ignored separately for each path,
4677 * but that configuration can be overridden from the command line.
4678 */
4679static int is_submodule_ignored(const char *path, struct diff_options *options)
4680{
4681        int ignored = 0;
4682        unsigned orig_flags = options->flags;
4683        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4684                set_diffopt_flags_from_submodule_config(options, path);
4685        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4686                ignored = 1;
4687        options->flags = orig_flags;
4688        return ignored;
4689}
4690
4691void diff_addremove(struct diff_options *options,
4692                    int addremove, unsigned mode,
4693                    const unsigned char *sha1,
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, mode);
4726        if (addremove != '-') {
4727                fill_filespec(two, sha1, 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                 const char *concatpath,
4741                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4742{
4743        struct diff_filespec *one, *two;
4744
4745        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4746            is_submodule_ignored(concatpath, options))
4747                return;
4748
4749        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4750                unsigned tmp;
4751                const unsigned char *tmp_c;
4752                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4753                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4754                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4755                        new_dirty_submodule = tmp;
4756        }
4757
4758        if (options->prefix &&
4759            strncmp(concatpath, options->prefix, options->prefix_length))
4760                return;
4761
4762        one = alloc_filespec(concatpath);
4763        two = alloc_filespec(concatpath);
4764        fill_filespec(one, old_sha1, old_mode);
4765        fill_filespec(two, new_sha1, new_mode);
4766        one->dirty_submodule = old_dirty_submodule;
4767        two->dirty_submodule = new_dirty_submodule;
4768
4769        diff_queue(&diff_queued_diff, one, two);
4770        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4771                DIFF_OPT_SET(options, HAS_CHANGES);
4772}
4773
4774struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4775{
4776        struct diff_filepair *pair;
4777        struct diff_filespec *one, *two;
4778
4779        if (options->prefix &&
4780            strncmp(path, options->prefix, options->prefix_length))
4781                return NULL;
4782
4783        one = alloc_filespec(path);
4784        two = alloc_filespec(path);
4785        pair = diff_queue(&diff_queued_diff, one, two);
4786        pair->is_unmerged = 1;
4787        return pair;
4788}
4789
4790static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4791                size_t *outsize)
4792{
4793        struct diff_tempfile *temp;
4794        const char *argv[3];
4795        const char **arg = argv;
4796        struct child_process child;
4797        struct strbuf buf = STRBUF_INIT;
4798        int err = 0;
4799
4800        temp = prepare_temp_file(spec->path, spec);
4801        *arg++ = pgm;
4802        *arg++ = temp->name;
4803        *arg = NULL;
4804
4805        memset(&child, 0, sizeof(child));
4806        child.use_shell = 1;
4807        child.argv = argv;
4808        child.out = -1;
4809        if (start_command(&child)) {
4810                remove_tempfile();
4811                return NULL;
4812        }
4813
4814        if (strbuf_read(&buf, child.out, 0) < 0)
4815                err = error("error reading from textconv command '%s'", pgm);
4816        close(child.out);
4817
4818        if (finish_command(&child) || err) {
4819                strbuf_release(&buf);
4820                remove_tempfile();
4821                return NULL;
4822        }
4823        remove_tempfile();
4824
4825        return strbuf_detach(&buf, outsize);
4826}
4827
4828size_t fill_textconv(struct userdiff_driver *driver,
4829                     struct diff_filespec *df,
4830                     char **outbuf)
4831{
4832        size_t size;
4833
4834        if (!driver || !driver->textconv) {
4835                if (!DIFF_FILE_VALID(df)) {
4836                        *outbuf = "";
4837                        return 0;
4838                }
4839                if (diff_populate_filespec(df, 0))
4840                        die("unable to read files to diff");
4841                *outbuf = df->data;
4842                return df->size;
4843        }
4844
4845        if (driver->textconv_cache && df->sha1_valid) {
4846                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4847                                          &size);
4848                if (*outbuf)
4849                        return size;
4850        }
4851
4852        *outbuf = run_textconv(driver->textconv, df, &size);
4853        if (!*outbuf)
4854                die("unable to read files to diff");
4855
4856        if (driver->textconv_cache && df->sha1_valid) {
4857                /* ignore errors, as we might be in a readonly repository */
4858                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4859                                size);
4860                /*
4861                 * we could save up changes and flush them all at the end,
4862                 * but we would need an extra call after all diffing is done.
4863                 * Since generating a cache entry is the slow path anyway,
4864                 * this extra overhead probably isn't a big deal.
4865                 */
4866                notes_cache_write(driver->textconv_cache);
4867        }
4868
4869        return size;
4870}