diff.con commit l10n: Review zh_CN translation for Git 1.7.10-rc1 (90e6ef5)
   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 free_diff_words_data(struct emit_callback *ecbdata)
 993{
 994        if (ecbdata->diff_words) {
 995                diff_words_flush(ecbdata);
 996                free (ecbdata->diff_words->minus.text.ptr);
 997                free (ecbdata->diff_words->minus.orig);
 998                free (ecbdata->diff_words->plus.text.ptr);
 999                free (ecbdata->diff_words->plus.orig);
1000                if (ecbdata->diff_words->word_regex) {
1001                        regfree(ecbdata->diff_words->word_regex);
1002                        free(ecbdata->diff_words->word_regex);
1003                }
1004                free(ecbdata->diff_words);
1005                ecbdata->diff_words = NULL;
1006        }
1007}
1008
1009const char *diff_get_color(int diff_use_color, enum color_diff ix)
1010{
1011        if (want_color(diff_use_color))
1012                return diff_colors[ix];
1013        return "";
1014}
1015
1016static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1017{
1018        const char *cp;
1019        unsigned long allot;
1020        size_t l = len;
1021
1022        if (ecb->truncate)
1023                return ecb->truncate(line, len);
1024        cp = line;
1025        allot = l;
1026        while (0 < l) {
1027                (void) utf8_width(&cp, &l);
1028                if (!cp)
1029                        break; /* truncated in the middle? */
1030        }
1031        return allot - l;
1032}
1033
1034static void find_lno(const char *line, struct emit_callback *ecbdata)
1035{
1036        const char *p;
1037        ecbdata->lno_in_preimage = 0;
1038        ecbdata->lno_in_postimage = 0;
1039        p = strchr(line, '-');
1040        if (!p)
1041                return; /* cannot happen */
1042        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1043        p = strchr(p, '+');
1044        if (!p)
1045                return; /* cannot happen */
1046        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1047}
1048
1049static void fn_out_consume(void *priv, char *line, unsigned long len)
1050{
1051        struct emit_callback *ecbdata = priv;
1052        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1053        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1054        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1055        struct diff_options *o = ecbdata->opt;
1056        char *line_prefix = "";
1057        struct strbuf *msgbuf;
1058
1059        if (o && o->output_prefix) {
1060                msgbuf = o->output_prefix(o, o->output_prefix_data);
1061                line_prefix = msgbuf->buf;
1062        }
1063
1064        if (ecbdata->header) {
1065                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1066                strbuf_reset(ecbdata->header);
1067                ecbdata->header = NULL;
1068        }
1069        *(ecbdata->found_changesp) = 1;
1070
1071        if (ecbdata->label_path[0]) {
1072                const char *name_a_tab, *name_b_tab;
1073
1074                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1075                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1076
1077                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1078                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1079                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1080                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1081                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1082        }
1083
1084        if (diff_suppress_blank_empty
1085            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1086                line[0] = '\n';
1087                len = 1;
1088        }
1089
1090        if (line[0] == '@') {
1091                if (ecbdata->diff_words)
1092                        diff_words_flush(ecbdata);
1093                len = sane_truncate_line(ecbdata, line, len);
1094                find_lno(line, ecbdata);
1095                emit_hunk_header(ecbdata, line, len);
1096                if (line[len-1] != '\n')
1097                        putc('\n', ecbdata->opt->file);
1098                return;
1099        }
1100
1101        if (len < 1) {
1102                emit_line(ecbdata->opt, reset, reset, line, len);
1103                if (ecbdata->diff_words
1104                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1105                        fputs("~\n", ecbdata->opt->file);
1106                return;
1107        }
1108
1109        if (ecbdata->diff_words) {
1110                if (line[0] == '-') {
1111                        diff_words_append(line, len,
1112                                          &ecbdata->diff_words->minus);
1113                        return;
1114                } else if (line[0] == '+') {
1115                        diff_words_append(line, len,
1116                                          &ecbdata->diff_words->plus);
1117                        return;
1118                } else if (!prefixcmp(line, "\\ ")) {
1119                        /*
1120                         * Eat the "no newline at eof" marker as if we
1121                         * saw a "+" or "-" line with nothing on it,
1122                         * and return without diff_words_flush() to
1123                         * defer processing. If this is the end of
1124                         * preimage, more "+" lines may come after it.
1125                         */
1126                        return;
1127                }
1128                diff_words_flush(ecbdata);
1129                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1130                        emit_line(ecbdata->opt, plain, reset, line, len);
1131                        fputs("~\n", ecbdata->opt->file);
1132                } else {
1133                        /*
1134                         * Skip the prefix character, if any.  With
1135                         * diff_suppress_blank_empty, there may be
1136                         * none.
1137                         */
1138                        if (line[0] != '\n') {
1139                              line++;
1140                              len--;
1141                        }
1142                        emit_line(ecbdata->opt, plain, reset, line, len);
1143                }
1144                return;
1145        }
1146
1147        if (line[0] != '+') {
1148                const char *color =
1149                        diff_get_color(ecbdata->color_diff,
1150                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1151                ecbdata->lno_in_preimage++;
1152                if (line[0] == ' ')
1153                        ecbdata->lno_in_postimage++;
1154                emit_line(ecbdata->opt, color, reset, line, len);
1155        } else {
1156                ecbdata->lno_in_postimage++;
1157                emit_add_line(reset, ecbdata, line + 1, len - 1);
1158        }
1159}
1160
1161static char *pprint_rename(const char *a, const char *b)
1162{
1163        const char *old = a;
1164        const char *new = b;
1165        struct strbuf name = STRBUF_INIT;
1166        int pfx_length, sfx_length;
1167        int len_a = strlen(a);
1168        int len_b = strlen(b);
1169        int a_midlen, b_midlen;
1170        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1171        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1172
1173        if (qlen_a || qlen_b) {
1174                quote_c_style(a, &name, NULL, 0);
1175                strbuf_addstr(&name, " => ");
1176                quote_c_style(b, &name, NULL, 0);
1177                return strbuf_detach(&name, NULL);
1178        }
1179
1180        /* Find common prefix */
1181        pfx_length = 0;
1182        while (*old && *new && *old == *new) {
1183                if (*old == '/')
1184                        pfx_length = old - a + 1;
1185                old++;
1186                new++;
1187        }
1188
1189        /* Find common suffix */
1190        old = a + len_a;
1191        new = b + len_b;
1192        sfx_length = 0;
1193        while (a <= old && b <= new && *old == *new) {
1194                if (*old == '/')
1195                        sfx_length = len_a - (old - a);
1196                old--;
1197                new--;
1198        }
1199
1200        /*
1201         * pfx{mid-a => mid-b}sfx
1202         * {pfx-a => pfx-b}sfx
1203         * pfx{sfx-a => sfx-b}
1204         * name-a => name-b
1205         */
1206        a_midlen = len_a - pfx_length - sfx_length;
1207        b_midlen = len_b - pfx_length - sfx_length;
1208        if (a_midlen < 0)
1209                a_midlen = 0;
1210        if (b_midlen < 0)
1211                b_midlen = 0;
1212
1213        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1214        if (pfx_length + sfx_length) {
1215                strbuf_add(&name, a, pfx_length);
1216                strbuf_addch(&name, '{');
1217        }
1218        strbuf_add(&name, a + pfx_length, a_midlen);
1219        strbuf_addstr(&name, " => ");
1220        strbuf_add(&name, b + pfx_length, b_midlen);
1221        if (pfx_length + sfx_length) {
1222                strbuf_addch(&name, '}');
1223                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1224        }
1225        return strbuf_detach(&name, NULL);
1226}
1227
1228struct diffstat_t {
1229        int nr;
1230        int alloc;
1231        struct diffstat_file {
1232                char *from_name;
1233                char *name;
1234                char *print_name;
1235                unsigned is_unmerged:1;
1236                unsigned is_binary:1;
1237                unsigned is_renamed:1;
1238                uintmax_t added, deleted;
1239        } **files;
1240};
1241
1242static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1243                                          const char *name_a,
1244                                          const char *name_b)
1245{
1246        struct diffstat_file *x;
1247        x = xcalloc(sizeof (*x), 1);
1248        if (diffstat->nr == diffstat->alloc) {
1249                diffstat->alloc = alloc_nr(diffstat->alloc);
1250                diffstat->files = xrealloc(diffstat->files,
1251                                diffstat->alloc * sizeof(x));
1252        }
1253        diffstat->files[diffstat->nr++] = x;
1254        if (name_b) {
1255                x->from_name = xstrdup(name_a);
1256                x->name = xstrdup(name_b);
1257                x->is_renamed = 1;
1258        }
1259        else {
1260                x->from_name = NULL;
1261                x->name = xstrdup(name_a);
1262        }
1263        return x;
1264}
1265
1266static void diffstat_consume(void *priv, char *line, unsigned long len)
1267{
1268        struct diffstat_t *diffstat = priv;
1269        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1270
1271        if (line[0] == '+')
1272                x->added++;
1273        else if (line[0] == '-')
1274                x->deleted++;
1275}
1276
1277const char mime_boundary_leader[] = "------------";
1278
1279static int scale_linear(int it, int width, int max_change)
1280{
1281        if (!it)
1282                return 0;
1283        /*
1284         * make sure that at least one '-' or '+' is printed if
1285         * there is any change to this path. The easiest way is to
1286         * scale linearly as if the alloted width is one column shorter
1287         * than it is, and then add 1 to the result.
1288         */
1289        return 1 + (it * (width - 1) / max_change);
1290}
1291
1292static void show_name(FILE *file,
1293                      const char *prefix, const char *name, int len)
1294{
1295        fprintf(file, " %s%-*s |", prefix, len, name);
1296}
1297
1298static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1299{
1300        if (cnt <= 0)
1301                return;
1302        fprintf(file, "%s", set);
1303        while (cnt--)
1304                putc(ch, file);
1305        fprintf(file, "%s", reset);
1306}
1307
1308static void fill_print_name(struct diffstat_file *file)
1309{
1310        char *pname;
1311
1312        if (file->print_name)
1313                return;
1314
1315        if (!file->is_renamed) {
1316                struct strbuf buf = STRBUF_INIT;
1317                if (quote_c_style(file->name, &buf, NULL, 0)) {
1318                        pname = strbuf_detach(&buf, NULL);
1319                } else {
1320                        pname = file->name;
1321                        strbuf_release(&buf);
1322                }
1323        } else {
1324                pname = pprint_rename(file->from_name, file->name);
1325        }
1326        file->print_name = pname;
1327}
1328
1329int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1330{
1331        struct strbuf sb = STRBUF_INIT;
1332        int ret;
1333
1334        if (!files) {
1335                assert(insertions == 0 && deletions == 0);
1336                return fputs(_(" 0 files changed\n"), fp);
1337        }
1338
1339        strbuf_addf(&sb,
1340                    Q_(" %d file changed", " %d files changed", files),
1341                    files);
1342
1343        /*
1344         * For binary diff, the caller may want to print "x files
1345         * changed" with insertions == 0 && deletions == 0.
1346         *
1347         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1348         * is probably less confusing (i.e skip over "2 files changed
1349         * but nothing about added/removed lines? Is this a bug in Git?").
1350         */
1351        if (insertions || deletions == 0) {
1352                /*
1353                 * TRANSLATORS: "+" in (+) is a line addition marker;
1354                 * do not translate it.
1355                 */
1356                strbuf_addf(&sb,
1357                            Q_(", %d insertion(+)", ", %d insertions(+)",
1358                               insertions),
1359                            insertions);
1360        }
1361
1362        if (deletions || insertions == 0) {
1363                /*
1364                 * TRANSLATORS: "-" in (-) is a line removal marker;
1365                 * do not translate it.
1366                 */
1367                strbuf_addf(&sb,
1368                            Q_(", %d deletion(-)", ", %d deletions(-)",
1369                               deletions),
1370                            deletions);
1371        }
1372        strbuf_addch(&sb, '\n');
1373        ret = fputs(sb.buf, fp);
1374        strbuf_release(&sb);
1375        return ret;
1376}
1377
1378static void show_stats(struct diffstat_t *data, struct diff_options *options)
1379{
1380        int i, len, add, del, adds = 0, dels = 0;
1381        uintmax_t max_change = 0, max_len = 0;
1382        int total_files = data->nr;
1383        int width, name_width, graph_width, number_width = 4, count;
1384        const char *reset, *add_c, *del_c;
1385        const char *line_prefix = "";
1386        int extra_shown = 0;
1387        struct strbuf *msg = NULL;
1388
1389        if (data->nr == 0)
1390                return;
1391
1392        if (options->output_prefix) {
1393                msg = options->output_prefix(options, options->output_prefix_data);
1394                line_prefix = msg->buf;
1395        }
1396
1397        count = options->stat_count ? options->stat_count : data->nr;
1398
1399        reset = diff_get_color_opt(options, DIFF_RESET);
1400        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1401        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1402
1403        /*
1404         * Find the longest filename and max number of changes
1405         */
1406        for (i = 0; (i < count) && (i < data->nr); i++) {
1407                struct diffstat_file *file = data->files[i];
1408                uintmax_t change = file->added + file->deleted;
1409                if (!data->files[i]->is_renamed &&
1410                         (change == 0)) {
1411                        count++; /* not shown == room for one more */
1412                        continue;
1413                }
1414                fill_print_name(file);
1415                len = strlen(file->print_name);
1416                if (max_len < len)
1417                        max_len = len;
1418
1419                if (file->is_binary || file->is_unmerged)
1420                        continue;
1421                if (max_change < change)
1422                        max_change = change;
1423        }
1424        count = i; /* min(count, data->nr) */
1425
1426        /*
1427         * We have width = stat_width or term_columns() columns total.
1428         * We want a maximum of min(max_len, stat_name_width) for the name part.
1429         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1430         * We also need 1 for " " and 4 + decimal_width(max_change)
1431         * for " | NNNN " and one the empty column at the end, altogether
1432         * 6 + decimal_width(max_change).
1433         *
1434         * If there's not enough space, we will use the smaller of
1435         * stat_name_width (if set) and 5/8*width for the filename,
1436         * and the rest for constant elements + graph part, but no more
1437         * than stat_graph_width for the graph part.
1438         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1439         * for the standard terminal size).
1440         *
1441         * In other words: stat_width limits the maximum width, and
1442         * stat_name_width fixes the maximum width of the filename,
1443         * and is also used to divide available columns if there
1444         * aren't enough.
1445         */
1446
1447        if (options->stat_width == -1)
1448                width = term_columns();
1449        else
1450                width = options->stat_width ? options->stat_width : 80;
1451
1452        if (options->stat_graph_width == -1)
1453                options->stat_graph_width = diff_stat_graph_width;
1454
1455        /*
1456         * Guarantee 3/8*16==6 for the graph part
1457         * and 5/8*16==10 for the filename part
1458         */
1459        if (width < 16 + 6 + number_width)
1460                width = 16 + 6 + number_width;
1461
1462        /*
1463         * First assign sizes that are wanted, ignoring available width.
1464         */
1465        graph_width = (options->stat_graph_width &&
1466                       options->stat_graph_width < max_change) ?
1467                options->stat_graph_width : max_change;
1468        name_width = (options->stat_name_width > 0 &&
1469                      options->stat_name_width < max_len) ?
1470                options->stat_name_width : max_len;
1471
1472        /*
1473         * Adjust adjustable widths not to exceed maximum width
1474         */
1475        if (name_width + number_width + 6 + graph_width > width) {
1476                if (graph_width > width * 3/8 - number_width - 6)
1477                        graph_width = width * 3/8 - number_width - 6;
1478                if (options->stat_graph_width &&
1479                    graph_width > options->stat_graph_width)
1480                        graph_width = options->stat_graph_width;
1481                if (name_width > width - number_width - 6 - graph_width)
1482                        name_width = width - number_width - 6 - graph_width;
1483                else
1484                        graph_width = width - number_width - 6 - name_width;
1485        }
1486
1487        /*
1488         * From here name_width is the width of the name area,
1489         * and graph_width is the width of the graph area.
1490         * max_change is used to scale graph properly.
1491         */
1492        for (i = 0; i < count; i++) {
1493                const char *prefix = "";
1494                char *name = data->files[i]->print_name;
1495                uintmax_t added = data->files[i]->added;
1496                uintmax_t deleted = data->files[i]->deleted;
1497                int name_len;
1498
1499                if (!data->files[i]->is_renamed &&
1500                         (added + deleted == 0)) {
1501                        total_files--;
1502                        continue;
1503                }
1504                /*
1505                 * "scale" the filename
1506                 */
1507                len = name_width;
1508                name_len = strlen(name);
1509                if (name_width < name_len) {
1510                        char *slash;
1511                        prefix = "...";
1512                        len -= 3;
1513                        name += name_len - len;
1514                        slash = strchr(name, '/');
1515                        if (slash)
1516                                name = slash;
1517                }
1518
1519                if (data->files[i]->is_binary) {
1520                        fprintf(options->file, "%s", line_prefix);
1521                        show_name(options->file, prefix, name, len);
1522                        fprintf(options->file, "  Bin ");
1523                        fprintf(options->file, "%s%"PRIuMAX"%s",
1524                                del_c, deleted, reset);
1525                        fprintf(options->file, " -> ");
1526                        fprintf(options->file, "%s%"PRIuMAX"%s",
1527                                add_c, added, reset);
1528                        fprintf(options->file, " bytes");
1529                        fprintf(options->file, "\n");
1530                        continue;
1531                }
1532                else if (data->files[i]->is_unmerged) {
1533                        fprintf(options->file, "%s", line_prefix);
1534                        show_name(options->file, prefix, name, len);
1535                        fprintf(options->file, "  Unmerged\n");
1536                        continue;
1537                }
1538
1539                /*
1540                 * scale the add/delete
1541                 */
1542                add = added;
1543                del = deleted;
1544                adds += add;
1545                dels += del;
1546
1547                if (graph_width <= max_change) {
1548                        int total = add + del;
1549
1550                        total = scale_linear(add + del, graph_width, max_change);
1551                        if (total < 2 && add && del)
1552                                /* width >= 2 due to the sanity check */
1553                                total = 2;
1554                        if (add < del) {
1555                                add = scale_linear(add, graph_width, max_change);
1556                                del = total - add;
1557                        } else {
1558                                del = scale_linear(del, graph_width, max_change);
1559                                add = total - del;
1560                        }
1561                }
1562                fprintf(options->file, "%s", line_prefix);
1563                show_name(options->file, prefix, name, len);
1564                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1565                                added + deleted ? " " : "");
1566                show_graph(options->file, '+', add, add_c, reset);
1567                show_graph(options->file, '-', del, del_c, reset);
1568                fprintf(options->file, "\n");
1569        }
1570        for (i = count; i < data->nr; i++) {
1571                uintmax_t added = data->files[i]->added;
1572                uintmax_t deleted = data->files[i]->deleted;
1573                if (!data->files[i]->is_renamed &&
1574                         (added + deleted == 0)) {
1575                        total_files--;
1576                        continue;
1577                }
1578                adds += added;
1579                dels += deleted;
1580                if (!extra_shown)
1581                        fprintf(options->file, "%s ...\n", line_prefix);
1582                extra_shown = 1;
1583        }
1584        fprintf(options->file, "%s", line_prefix);
1585        print_stat_summary(options->file, total_files, adds, dels);
1586}
1587
1588static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1589{
1590        int i, adds = 0, dels = 0, total_files = data->nr;
1591
1592        if (data->nr == 0)
1593                return;
1594
1595        for (i = 0; i < data->nr; i++) {
1596                if (!data->files[i]->is_binary &&
1597                    !data->files[i]->is_unmerged) {
1598                        int added = data->files[i]->added;
1599                        int deleted= data->files[i]->deleted;
1600                        if (!data->files[i]->is_renamed &&
1601                            (added + deleted == 0)) {
1602                                total_files--;
1603                        } else {
1604                                adds += added;
1605                                dels += deleted;
1606                        }
1607                }
1608        }
1609        if (options->output_prefix) {
1610                struct strbuf *msg = NULL;
1611                msg = options->output_prefix(options,
1612                                options->output_prefix_data);
1613                fprintf(options->file, "%s", msg->buf);
1614        }
1615        print_stat_summary(options->file, total_files, adds, dels);
1616}
1617
1618static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1619{
1620        int i;
1621
1622        if (data->nr == 0)
1623                return;
1624
1625        for (i = 0; i < data->nr; i++) {
1626                struct diffstat_file *file = data->files[i];
1627
1628                if (options->output_prefix) {
1629                        struct strbuf *msg = NULL;
1630                        msg = options->output_prefix(options,
1631                                        options->output_prefix_data);
1632                        fprintf(options->file, "%s", msg->buf);
1633                }
1634
1635                if (file->is_binary)
1636                        fprintf(options->file, "-\t-\t");
1637                else
1638                        fprintf(options->file,
1639                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1640                                file->added, file->deleted);
1641                if (options->line_termination) {
1642                        fill_print_name(file);
1643                        if (!file->is_renamed)
1644                                write_name_quoted(file->name, options->file,
1645                                                  options->line_termination);
1646                        else {
1647                                fputs(file->print_name, options->file);
1648                                putc(options->line_termination, options->file);
1649                        }
1650                } else {
1651                        if (file->is_renamed) {
1652                                putc('\0', options->file);
1653                                write_name_quoted(file->from_name, options->file, '\0');
1654                        }
1655                        write_name_quoted(file->name, options->file, '\0');
1656                }
1657        }
1658}
1659
1660struct dirstat_file {
1661        const char *name;
1662        unsigned long changed;
1663};
1664
1665struct dirstat_dir {
1666        struct dirstat_file *files;
1667        int alloc, nr, permille, cumulative;
1668};
1669
1670static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1671                unsigned long changed, const char *base, int baselen)
1672{
1673        unsigned long this_dir = 0;
1674        unsigned int sources = 0;
1675        const char *line_prefix = "";
1676        struct strbuf *msg = NULL;
1677
1678        if (opt->output_prefix) {
1679                msg = opt->output_prefix(opt, opt->output_prefix_data);
1680                line_prefix = msg->buf;
1681        }
1682
1683        while (dir->nr) {
1684                struct dirstat_file *f = dir->files;
1685                int namelen = strlen(f->name);
1686                unsigned long this;
1687                char *slash;
1688
1689                if (namelen < baselen)
1690                        break;
1691                if (memcmp(f->name, base, baselen))
1692                        break;
1693                slash = strchr(f->name + baselen, '/');
1694                if (slash) {
1695                        int newbaselen = slash + 1 - f->name;
1696                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1697                        sources++;
1698                } else {
1699                        this = f->changed;
1700                        dir->files++;
1701                        dir->nr--;
1702                        sources += 2;
1703                }
1704                this_dir += this;
1705        }
1706
1707        /*
1708         * We don't report dirstat's for
1709         *  - the top level
1710         *  - or cases where everything came from a single directory
1711         *    under this directory (sources == 1).
1712         */
1713        if (baselen && sources != 1) {
1714                if (this_dir) {
1715                        int permille = this_dir * 1000 / changed;
1716                        if (permille >= dir->permille) {
1717                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1718                                        permille / 10, permille % 10, baselen, base);
1719                                if (!dir->cumulative)
1720                                        return 0;
1721                        }
1722                }
1723        }
1724        return this_dir;
1725}
1726
1727static int dirstat_compare(const void *_a, const void *_b)
1728{
1729        const struct dirstat_file *a = _a;
1730        const struct dirstat_file *b = _b;
1731        return strcmp(a->name, b->name);
1732}
1733
1734static void show_dirstat(struct diff_options *options)
1735{
1736        int i;
1737        unsigned long changed;
1738        struct dirstat_dir dir;
1739        struct diff_queue_struct *q = &diff_queued_diff;
1740
1741        dir.files = NULL;
1742        dir.alloc = 0;
1743        dir.nr = 0;
1744        dir.permille = options->dirstat_permille;
1745        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1746
1747        changed = 0;
1748        for (i = 0; i < q->nr; i++) {
1749                struct diff_filepair *p = q->queue[i];
1750                const char *name;
1751                unsigned long copied, added, damage;
1752                int content_changed;
1753
1754                name = p->two->path ? p->two->path : p->one->path;
1755
1756                if (p->one->sha1_valid && p->two->sha1_valid)
1757                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1758                else
1759                        content_changed = 1;
1760
1761                if (!content_changed) {
1762                        /*
1763                         * The SHA1 has not changed, so pre-/post-content is
1764                         * identical. We can therefore skip looking at the
1765                         * file contents altogether.
1766                         */
1767                        damage = 0;
1768                        goto found_damage;
1769                }
1770
1771                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1772                        /*
1773                         * In --dirstat-by-file mode, we don't really need to
1774                         * look at the actual file contents at all.
1775                         * The fact that the SHA1 changed is enough for us to
1776                         * add this file to the list of results
1777                         * (with each file contributing equal damage).
1778                         */
1779                        damage = 1;
1780                        goto found_damage;
1781                }
1782
1783                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1784                        diff_populate_filespec(p->one, 0);
1785                        diff_populate_filespec(p->two, 0);
1786                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1787                                               &copied, &added);
1788                        diff_free_filespec_data(p->one);
1789                        diff_free_filespec_data(p->two);
1790                } else if (DIFF_FILE_VALID(p->one)) {
1791                        diff_populate_filespec(p->one, 1);
1792                        copied = added = 0;
1793                        diff_free_filespec_data(p->one);
1794                } else if (DIFF_FILE_VALID(p->two)) {
1795                        diff_populate_filespec(p->two, 1);
1796                        copied = 0;
1797                        added = p->two->size;
1798                        diff_free_filespec_data(p->two);
1799                } else
1800                        continue;
1801
1802                /*
1803                 * Original minus copied is the removed material,
1804                 * added is the new material.  They are both damages
1805                 * made to the preimage.
1806                 * If the resulting damage is zero, we know that
1807                 * diffcore_count_changes() considers the two entries to
1808                 * be identical, but since content_changed is true, we
1809                 * know that there must have been _some_ kind of change,
1810                 * so we force all entries to have damage > 0.
1811                 */
1812                damage = (p->one->size - copied) + added;
1813                if (!damage)
1814                        damage = 1;
1815
1816found_damage:
1817                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1818                dir.files[dir.nr].name = name;
1819                dir.files[dir.nr].changed = damage;
1820                changed += damage;
1821                dir.nr++;
1822        }
1823
1824        /* This can happen even with many files, if everything was renames */
1825        if (!changed)
1826                return;
1827
1828        /* Show all directories with more than x% of the changes */
1829        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1830        gather_dirstat(options, &dir, changed, "", 0);
1831}
1832
1833static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1834{
1835        int i;
1836        unsigned long changed;
1837        struct dirstat_dir dir;
1838
1839        if (data->nr == 0)
1840                return;
1841
1842        dir.files = NULL;
1843        dir.alloc = 0;
1844        dir.nr = 0;
1845        dir.permille = options->dirstat_permille;
1846        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1847
1848        changed = 0;
1849        for (i = 0; i < data->nr; i++) {
1850                struct diffstat_file *file = data->files[i];
1851                unsigned long damage = file->added + file->deleted;
1852                if (file->is_binary)
1853                        /*
1854                         * binary files counts bytes, not lines. Must find some
1855                         * way to normalize binary bytes vs. textual lines.
1856                         * The following heuristic assumes that there are 64
1857                         * bytes per "line".
1858                         * This is stupid and ugly, but very cheap...
1859                         */
1860                        damage = (damage + 63) / 64;
1861                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1862                dir.files[dir.nr].name = file->name;
1863                dir.files[dir.nr].changed = damage;
1864                changed += damage;
1865                dir.nr++;
1866        }
1867
1868        /* This can happen even with many files, if everything was renames */
1869        if (!changed)
1870                return;
1871
1872        /* Show all directories with more than x% of the changes */
1873        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1874        gather_dirstat(options, &dir, changed, "", 0);
1875}
1876
1877static void free_diffstat_info(struct diffstat_t *diffstat)
1878{
1879        int i;
1880        for (i = 0; i < diffstat->nr; i++) {
1881                struct diffstat_file *f = diffstat->files[i];
1882                if (f->name != f->print_name)
1883                        free(f->print_name);
1884                free(f->name);
1885                free(f->from_name);
1886                free(f);
1887        }
1888        free(diffstat->files);
1889}
1890
1891struct checkdiff_t {
1892        const char *filename;
1893        int lineno;
1894        int conflict_marker_size;
1895        struct diff_options *o;
1896        unsigned ws_rule;
1897        unsigned status;
1898};
1899
1900static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1901{
1902        char firstchar;
1903        int cnt;
1904
1905        if (len < marker_size + 1)
1906                return 0;
1907        firstchar = line[0];
1908        switch (firstchar) {
1909        case '=': case '>': case '<': case '|':
1910                break;
1911        default:
1912                return 0;
1913        }
1914        for (cnt = 1; cnt < marker_size; cnt++)
1915                if (line[cnt] != firstchar)
1916                        return 0;
1917        /* line[1] thru line[marker_size-1] are same as firstchar */
1918        if (len < marker_size + 1 || !isspace(line[marker_size]))
1919                return 0;
1920        return 1;
1921}
1922
1923static void checkdiff_consume(void *priv, char *line, unsigned long len)
1924{
1925        struct checkdiff_t *data = priv;
1926        int marker_size = data->conflict_marker_size;
1927        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
1928        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
1929        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
1930        char *err;
1931        char *line_prefix = "";
1932        struct strbuf *msgbuf;
1933
1934        assert(data->o);
1935        if (data->o->output_prefix) {
1936                msgbuf = data->o->output_prefix(data->o,
1937                        data->o->output_prefix_data);
1938                line_prefix = msgbuf->buf;
1939        }
1940
1941        if (line[0] == '+') {
1942                unsigned bad;
1943                data->lineno++;
1944                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1945                        data->status |= 1;
1946                        fprintf(data->o->file,
1947                                "%s%s:%d: leftover conflict marker\n",
1948                                line_prefix, data->filename, data->lineno);
1949                }
1950                bad = ws_check(line + 1, len - 1, data->ws_rule);
1951                if (!bad)
1952                        return;
1953                data->status |= bad;
1954                err = whitespace_error_string(bad);
1955                fprintf(data->o->file, "%s%s:%d: %s.\n",
1956                        line_prefix, data->filename, data->lineno, err);
1957                free(err);
1958                emit_line(data->o, set, reset, line, 1);
1959                ws_check_emit(line + 1, len - 1, data->ws_rule,
1960                              data->o->file, set, reset, ws);
1961        } else if (line[0] == ' ') {
1962                data->lineno++;
1963        } else if (line[0] == '@') {
1964                char *plus = strchr(line, '+');
1965                if (plus)
1966                        data->lineno = strtol(plus, NULL, 10) - 1;
1967                else
1968                        die("invalid diff");
1969        }
1970}
1971
1972static unsigned char *deflate_it(char *data,
1973                                 unsigned long size,
1974                                 unsigned long *result_size)
1975{
1976        int bound;
1977        unsigned char *deflated;
1978        git_zstream stream;
1979
1980        memset(&stream, 0, sizeof(stream));
1981        git_deflate_init(&stream, zlib_compression_level);
1982        bound = git_deflate_bound(&stream, size);
1983        deflated = xmalloc(bound);
1984        stream.next_out = deflated;
1985        stream.avail_out = bound;
1986
1987        stream.next_in = (unsigned char *)data;
1988        stream.avail_in = size;
1989        while (git_deflate(&stream, Z_FINISH) == Z_OK)
1990                ; /* nothing */
1991        git_deflate_end(&stream);
1992        *result_size = stream.total_out;
1993        return deflated;
1994}
1995
1996static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1997{
1998        void *cp;
1999        void *delta;
2000        void *deflated;
2001        void *data;
2002        unsigned long orig_size;
2003        unsigned long delta_size;
2004        unsigned long deflate_size;
2005        unsigned long data_size;
2006
2007        /* We could do deflated delta, or we could do just deflated two,
2008         * whichever is smaller.
2009         */
2010        delta = NULL;
2011        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2012        if (one->size && two->size) {
2013                delta = diff_delta(one->ptr, one->size,
2014                                   two->ptr, two->size,
2015                                   &delta_size, deflate_size);
2016                if (delta) {
2017                        void *to_free = delta;
2018                        orig_size = delta_size;
2019                        delta = deflate_it(delta, delta_size, &delta_size);
2020                        free(to_free);
2021                }
2022        }
2023
2024        if (delta && delta_size < deflate_size) {
2025                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2026                free(deflated);
2027                data = delta;
2028                data_size = delta_size;
2029        }
2030        else {
2031                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2032                free(delta);
2033                data = deflated;
2034                data_size = deflate_size;
2035        }
2036
2037        /* emit data encoded in base85 */
2038        cp = data;
2039        while (data_size) {
2040                int bytes = (52 < data_size) ? 52 : data_size;
2041                char line[70];
2042                data_size -= bytes;
2043                if (bytes <= 26)
2044                        line[0] = bytes + 'A' - 1;
2045                else
2046                        line[0] = bytes - 26 + 'a' - 1;
2047                encode_85(line + 1, cp, bytes);
2048                cp = (char *) cp + bytes;
2049                fprintf(file, "%s", prefix);
2050                fputs(line, file);
2051                fputc('\n', file);
2052        }
2053        fprintf(file, "%s\n", prefix);
2054        free(data);
2055}
2056
2057static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2058{
2059        fprintf(file, "%sGIT binary patch\n", prefix);
2060        emit_binary_diff_body(file, one, two, prefix);
2061        emit_binary_diff_body(file, two, one, prefix);
2062}
2063
2064static void diff_filespec_load_driver(struct diff_filespec *one)
2065{
2066        /* Use already-loaded driver */
2067        if (one->driver)
2068                return;
2069
2070        if (S_ISREG(one->mode))
2071                one->driver = userdiff_find_by_path(one->path);
2072
2073        /* Fallback to default settings */
2074        if (!one->driver)
2075                one->driver = userdiff_find_by_name("default");
2076}
2077
2078int diff_filespec_is_binary(struct diff_filespec *one)
2079{
2080        if (one->is_binary == -1) {
2081                diff_filespec_load_driver(one);
2082                if (one->driver->binary != -1)
2083                        one->is_binary = one->driver->binary;
2084                else {
2085                        if (!one->data && DIFF_FILE_VALID(one))
2086                                diff_populate_filespec(one, 0);
2087                        if (one->data)
2088                                one->is_binary = buffer_is_binary(one->data,
2089                                                one->size);
2090                        if (one->is_binary == -1)
2091                                one->is_binary = 0;
2092                }
2093        }
2094        return one->is_binary;
2095}
2096
2097static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2098{
2099        diff_filespec_load_driver(one);
2100        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2101}
2102
2103static const char *userdiff_word_regex(struct diff_filespec *one)
2104{
2105        diff_filespec_load_driver(one);
2106        return one->driver->word_regex;
2107}
2108
2109void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2110{
2111        if (!options->a_prefix)
2112                options->a_prefix = a;
2113        if (!options->b_prefix)
2114                options->b_prefix = b;
2115}
2116
2117struct userdiff_driver *get_textconv(struct diff_filespec *one)
2118{
2119        if (!DIFF_FILE_VALID(one))
2120                return NULL;
2121
2122        diff_filespec_load_driver(one);
2123        return userdiff_get_textconv(one->driver);
2124}
2125
2126static void builtin_diff(const char *name_a,
2127                         const char *name_b,
2128                         struct diff_filespec *one,
2129                         struct diff_filespec *two,
2130                         const char *xfrm_msg,
2131                         int must_show_header,
2132                         struct diff_options *o,
2133                         int complete_rewrite)
2134{
2135        mmfile_t mf1, mf2;
2136        const char *lbl[2];
2137        char *a_one, *b_two;
2138        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2139        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2140        const char *a_prefix, *b_prefix;
2141        struct userdiff_driver *textconv_one = NULL;
2142        struct userdiff_driver *textconv_two = NULL;
2143        struct strbuf header = STRBUF_INIT;
2144        struct strbuf *msgbuf;
2145        char *line_prefix = "";
2146
2147        if (o->output_prefix) {
2148                msgbuf = o->output_prefix(o, o->output_prefix_data);
2149                line_prefix = msgbuf->buf;
2150        }
2151
2152        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2153                        (!one->mode || S_ISGITLINK(one->mode)) &&
2154                        (!two->mode || S_ISGITLINK(two->mode))) {
2155                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2156                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2157                show_submodule_summary(o->file, one ? one->path : two->path,
2158                                one->sha1, two->sha1, two->dirty_submodule,
2159                                del, add, reset);
2160                return;
2161        }
2162
2163        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2164                textconv_one = get_textconv(one);
2165                textconv_two = get_textconv(two);
2166        }
2167
2168        diff_set_mnemonic_prefix(o, "a/", "b/");
2169        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2170                a_prefix = o->b_prefix;
2171                b_prefix = o->a_prefix;
2172        } else {
2173                a_prefix = o->a_prefix;
2174                b_prefix = o->b_prefix;
2175        }
2176
2177        /* Never use a non-valid filename anywhere if at all possible */
2178        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2179        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2180
2181        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2182        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2183        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2184        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2185        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2186        if (lbl[0][0] == '/') {
2187                /* /dev/null */
2188                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2189                if (xfrm_msg)
2190                        strbuf_addstr(&header, xfrm_msg);
2191                must_show_header = 1;
2192        }
2193        else if (lbl[1][0] == '/') {
2194                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2195                if (xfrm_msg)
2196                        strbuf_addstr(&header, xfrm_msg);
2197                must_show_header = 1;
2198        }
2199        else {
2200                if (one->mode != two->mode) {
2201                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2202                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2203                        must_show_header = 1;
2204                }
2205                if (xfrm_msg)
2206                        strbuf_addstr(&header, xfrm_msg);
2207
2208                /*
2209                 * we do not run diff between different kind
2210                 * of objects.
2211                 */
2212                if ((one->mode ^ two->mode) & S_IFMT)
2213                        goto free_ab_and_return;
2214                if (complete_rewrite &&
2215                    (textconv_one || !diff_filespec_is_binary(one)) &&
2216                    (textconv_two || !diff_filespec_is_binary(two))) {
2217                        fprintf(o->file, "%s", header.buf);
2218                        strbuf_reset(&header);
2219                        emit_rewrite_diff(name_a, name_b, one, two,
2220                                                textconv_one, textconv_two, o);
2221                        o->found_changes = 1;
2222                        goto free_ab_and_return;
2223                }
2224        }
2225
2226        if (o->irreversible_delete && lbl[1][0] == '/') {
2227                fprintf(o->file, "%s", header.buf);
2228                strbuf_reset(&header);
2229                goto free_ab_and_return;
2230        } else if (!DIFF_OPT_TST(o, TEXT) &&
2231            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2232              (!textconv_two && diff_filespec_is_binary(two)) )) {
2233                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2234                        die("unable to read files to diff");
2235                /* Quite common confusing case */
2236                if (mf1.size == mf2.size &&
2237                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2238                        if (must_show_header)
2239                                fprintf(o->file, "%s", header.buf);
2240                        goto free_ab_and_return;
2241                }
2242                fprintf(o->file, "%s", header.buf);
2243                strbuf_reset(&header);
2244                if (DIFF_OPT_TST(o, BINARY))
2245                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2246                else
2247                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2248                                line_prefix, lbl[0], lbl[1]);
2249                o->found_changes = 1;
2250        } else {
2251                /* Crazy xdl interfaces.. */
2252                const char *diffopts = getenv("GIT_DIFF_OPTS");
2253                xpparam_t xpp;
2254                xdemitconf_t xecfg;
2255                struct emit_callback ecbdata;
2256                const struct userdiff_funcname *pe;
2257
2258                if (must_show_header) {
2259                        fprintf(o->file, "%s", header.buf);
2260                        strbuf_reset(&header);
2261                }
2262
2263                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2264                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2265
2266                pe = diff_funcname_pattern(one);
2267                if (!pe)
2268                        pe = diff_funcname_pattern(two);
2269
2270                memset(&xpp, 0, sizeof(xpp));
2271                memset(&xecfg, 0, sizeof(xecfg));
2272                memset(&ecbdata, 0, sizeof(ecbdata));
2273                ecbdata.label_path = lbl;
2274                ecbdata.color_diff = want_color(o->use_color);
2275                ecbdata.found_changesp = &o->found_changes;
2276                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2277                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2278                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2279                ecbdata.opt = o;
2280                ecbdata.header = header.len ? &header : NULL;
2281                xpp.flags = o->xdl_opts;
2282                xecfg.ctxlen = o->context;
2283                xecfg.interhunkctxlen = o->interhunkcontext;
2284                xecfg.flags = XDL_EMIT_FUNCNAMES;
2285                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2286                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2287                if (pe)
2288                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2289                if (!diffopts)
2290                        ;
2291                else if (!prefixcmp(diffopts, "--unified="))
2292                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2293                else if (!prefixcmp(diffopts, "-u"))
2294                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2295                if (o->word_diff) {
2296                        int i;
2297
2298                        ecbdata.diff_words =
2299                                xcalloc(1, sizeof(struct diff_words_data));
2300                        ecbdata.diff_words->type = o->word_diff;
2301                        ecbdata.diff_words->opt = o;
2302                        if (!o->word_regex)
2303                                o->word_regex = userdiff_word_regex(one);
2304                        if (!o->word_regex)
2305                                o->word_regex = userdiff_word_regex(two);
2306                        if (!o->word_regex)
2307                                o->word_regex = diff_word_regex_cfg;
2308                        if (o->word_regex) {
2309                                ecbdata.diff_words->word_regex = (regex_t *)
2310                                        xmalloc(sizeof(regex_t));
2311                                if (regcomp(ecbdata.diff_words->word_regex,
2312                                                o->word_regex,
2313                                                REG_EXTENDED | REG_NEWLINE))
2314                                        die ("Invalid regular expression: %s",
2315                                                        o->word_regex);
2316                        }
2317                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2318                                if (o->word_diff == diff_words_styles[i].type) {
2319                                        ecbdata.diff_words->style =
2320                                                &diff_words_styles[i];
2321                                        break;
2322                                }
2323                        }
2324                        if (want_color(o->use_color)) {
2325                                struct diff_words_style *st = ecbdata.diff_words->style;
2326                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2327                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2328                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2329                        }
2330                }
2331                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2332                              &xpp, &xecfg);
2333                if (o->word_diff)
2334                        free_diff_words_data(&ecbdata);
2335                if (textconv_one)
2336                        free(mf1.ptr);
2337                if (textconv_two)
2338                        free(mf2.ptr);
2339                xdiff_clear_find_func(&xecfg);
2340        }
2341
2342 free_ab_and_return:
2343        strbuf_release(&header);
2344        diff_free_filespec_data(one);
2345        diff_free_filespec_data(two);
2346        free(a_one);
2347        free(b_two);
2348        return;
2349}
2350
2351static void builtin_diffstat(const char *name_a, const char *name_b,
2352                             struct diff_filespec *one,
2353                             struct diff_filespec *two,
2354                             struct diffstat_t *diffstat,
2355                             struct diff_options *o,
2356                             int complete_rewrite)
2357{
2358        mmfile_t mf1, mf2;
2359        struct diffstat_file *data;
2360
2361        data = diffstat_add(diffstat, name_a, name_b);
2362
2363        if (!one || !two) {
2364                data->is_unmerged = 1;
2365                return;
2366        }
2367
2368        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2369                data->is_binary = 1;
2370                data->added = diff_filespec_size(two);
2371                data->deleted = diff_filespec_size(one);
2372        }
2373
2374        else if (complete_rewrite) {
2375                diff_populate_filespec(one, 0);
2376                diff_populate_filespec(two, 0);
2377                data->deleted = count_lines(one->data, one->size);
2378                data->added = count_lines(two->data, two->size);
2379        }
2380
2381        else {
2382                /* Crazy xdl interfaces.. */
2383                xpparam_t xpp;
2384                xdemitconf_t xecfg;
2385
2386                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2387                        die("unable to read files to diff");
2388
2389                memset(&xpp, 0, sizeof(xpp));
2390                memset(&xecfg, 0, sizeof(xecfg));
2391                xpp.flags = o->xdl_opts;
2392                xecfg.ctxlen = o->context;
2393                xecfg.interhunkctxlen = o->interhunkcontext;
2394                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2395                              &xpp, &xecfg);
2396        }
2397
2398        diff_free_filespec_data(one);
2399        diff_free_filespec_data(two);
2400}
2401
2402static void builtin_checkdiff(const char *name_a, const char *name_b,
2403                              const char *attr_path,
2404                              struct diff_filespec *one,
2405                              struct diff_filespec *two,
2406                              struct diff_options *o)
2407{
2408        mmfile_t mf1, mf2;
2409        struct checkdiff_t data;
2410
2411        if (!two)
2412                return;
2413
2414        memset(&data, 0, sizeof(data));
2415        data.filename = name_b ? name_b : name_a;
2416        data.lineno = 0;
2417        data.o = o;
2418        data.ws_rule = whitespace_rule(attr_path);
2419        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2420
2421        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2422                die("unable to read files to diff");
2423
2424        /*
2425         * All the other codepaths check both sides, but not checking
2426         * the "old" side here is deliberate.  We are checking the newly
2427         * introduced changes, and as long as the "new" side is text, we
2428         * can and should check what it introduces.
2429         */
2430        if (diff_filespec_is_binary(two))
2431                goto free_and_return;
2432        else {
2433                /* Crazy xdl interfaces.. */
2434                xpparam_t xpp;
2435                xdemitconf_t xecfg;
2436
2437                memset(&xpp, 0, sizeof(xpp));
2438                memset(&xecfg, 0, sizeof(xecfg));
2439                xecfg.ctxlen = 1; /* at least one context line */
2440                xpp.flags = 0;
2441                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2442                              &xpp, &xecfg);
2443
2444                if (data.ws_rule & WS_BLANK_AT_EOF) {
2445                        struct emit_callback ecbdata;
2446                        int blank_at_eof;
2447
2448                        ecbdata.ws_rule = data.ws_rule;
2449                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2450                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2451
2452                        if (blank_at_eof) {
2453                                static char *err;
2454                                if (!err)
2455                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2456                                fprintf(o->file, "%s:%d: %s.\n",
2457                                        data.filename, blank_at_eof, err);
2458                                data.status = 1; /* report errors */
2459                        }
2460                }
2461        }
2462 free_and_return:
2463        diff_free_filespec_data(one);
2464        diff_free_filespec_data(two);
2465        if (data.status)
2466                DIFF_OPT_SET(o, CHECK_FAILED);
2467}
2468
2469struct diff_filespec *alloc_filespec(const char *path)
2470{
2471        int namelen = strlen(path);
2472        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2473
2474        memset(spec, 0, sizeof(*spec));
2475        spec->path = (char *)(spec + 1);
2476        memcpy(spec->path, path, namelen+1);
2477        spec->count = 1;
2478        spec->is_binary = -1;
2479        return spec;
2480}
2481
2482void free_filespec(struct diff_filespec *spec)
2483{
2484        if (!--spec->count) {
2485                diff_free_filespec_data(spec);
2486                free(spec);
2487        }
2488}
2489
2490void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2491                   unsigned short mode)
2492{
2493        if (mode) {
2494                spec->mode = canon_mode(mode);
2495                hashcpy(spec->sha1, sha1);
2496                spec->sha1_valid = !is_null_sha1(sha1);
2497        }
2498}
2499
2500/*
2501 * Given a name and sha1 pair, if the index tells us the file in
2502 * the work tree has that object contents, return true, so that
2503 * prepare_temp_file() does not have to inflate and extract.
2504 */
2505static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2506{
2507        struct cache_entry *ce;
2508        struct stat st;
2509        int pos, len;
2510
2511        /*
2512         * We do not read the cache ourselves here, because the
2513         * benchmark with my previous version that always reads cache
2514         * shows that it makes things worse for diff-tree comparing
2515         * two linux-2.6 kernel trees in an already checked out work
2516         * tree.  This is because most diff-tree comparisons deal with
2517         * only a small number of files, while reading the cache is
2518         * expensive for a large project, and its cost outweighs the
2519         * savings we get by not inflating the object to a temporary
2520         * file.  Practically, this code only helps when we are used
2521         * by diff-cache --cached, which does read the cache before
2522         * calling us.
2523         */
2524        if (!active_cache)
2525                return 0;
2526
2527        /* We want to avoid the working directory if our caller
2528         * doesn't need the data in a normal file, this system
2529         * is rather slow with its stat/open/mmap/close syscalls,
2530         * and the object is contained in a pack file.  The pack
2531         * is probably already open and will be faster to obtain
2532         * the data through than the working directory.  Loose
2533         * objects however would tend to be slower as they need
2534         * to be individually opened and inflated.
2535         */
2536        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2537                return 0;
2538
2539        len = strlen(name);
2540        pos = cache_name_pos(name, len);
2541        if (pos < 0)
2542                return 0;
2543        ce = active_cache[pos];
2544
2545        /*
2546         * This is not the sha1 we are looking for, or
2547         * unreusable because it is not a regular file.
2548         */
2549        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2550                return 0;
2551
2552        /*
2553         * If ce is marked as "assume unchanged", there is no
2554         * guarantee that work tree matches what we are looking for.
2555         */
2556        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2557                return 0;
2558
2559        /*
2560         * If ce matches the file in the work tree, we can reuse it.
2561         */
2562        if (ce_uptodate(ce) ||
2563            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2564                return 1;
2565
2566        return 0;
2567}
2568
2569static int populate_from_stdin(struct diff_filespec *s)
2570{
2571        struct strbuf buf = STRBUF_INIT;
2572        size_t size = 0;
2573
2574        if (strbuf_read(&buf, 0, 0) < 0)
2575                return error("error while reading from stdin %s",
2576                                     strerror(errno));
2577
2578        s->should_munmap = 0;
2579        s->data = strbuf_detach(&buf, &size);
2580        s->size = size;
2581        s->should_free = 1;
2582        return 0;
2583}
2584
2585static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2586{
2587        int len;
2588        char *data = xmalloc(100), *dirty = "";
2589
2590        /* Are we looking at the work tree? */
2591        if (s->dirty_submodule)
2592                dirty = "-dirty";
2593
2594        len = snprintf(data, 100,
2595                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2596        s->data = data;
2597        s->size = len;
2598        s->should_free = 1;
2599        if (size_only) {
2600                s->data = NULL;
2601                free(data);
2602        }
2603        return 0;
2604}
2605
2606/*
2607 * While doing rename detection and pickaxe operation, we may need to
2608 * grab the data for the blob (or file) for our own in-core comparison.
2609 * diff_filespec has data and size fields for this purpose.
2610 */
2611int diff_populate_filespec(struct diff_filespec *s, int size_only)
2612{
2613        int err = 0;
2614        if (!DIFF_FILE_VALID(s))
2615                die("internal error: asking to populate invalid file.");
2616        if (S_ISDIR(s->mode))
2617                return -1;
2618
2619        if (s->data)
2620                return 0;
2621
2622        if (size_only && 0 < s->size)
2623                return 0;
2624
2625        if (S_ISGITLINK(s->mode))
2626                return diff_populate_gitlink(s, size_only);
2627
2628        if (!s->sha1_valid ||
2629            reuse_worktree_file(s->path, s->sha1, 0)) {
2630                struct strbuf buf = STRBUF_INIT;
2631                struct stat st;
2632                int fd;
2633
2634                if (!strcmp(s->path, "-"))
2635                        return populate_from_stdin(s);
2636
2637                if (lstat(s->path, &st) < 0) {
2638                        if (errno == ENOENT) {
2639                        err_empty:
2640                                err = -1;
2641                        empty:
2642                                s->data = (char *)"";
2643                                s->size = 0;
2644                                return err;
2645                        }
2646                }
2647                s->size = xsize_t(st.st_size);
2648                if (!s->size)
2649                        goto empty;
2650                if (S_ISLNK(st.st_mode)) {
2651                        struct strbuf sb = STRBUF_INIT;
2652
2653                        if (strbuf_readlink(&sb, s->path, s->size))
2654                                goto err_empty;
2655                        s->size = sb.len;
2656                        s->data = strbuf_detach(&sb, NULL);
2657                        s->should_free = 1;
2658                        return 0;
2659                }
2660                if (size_only)
2661                        return 0;
2662                fd = open(s->path, O_RDONLY);
2663                if (fd < 0)
2664                        goto err_empty;
2665                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2666                close(fd);
2667                s->should_munmap = 1;
2668
2669                /*
2670                 * Convert from working tree format to canonical git format
2671                 */
2672                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2673                        size_t size = 0;
2674                        munmap(s->data, s->size);
2675                        s->should_munmap = 0;
2676                        s->data = strbuf_detach(&buf, &size);
2677                        s->size = size;
2678                        s->should_free = 1;
2679                }
2680        }
2681        else {
2682                enum object_type type;
2683                if (size_only) {
2684                        type = sha1_object_info(s->sha1, &s->size);
2685                        if (type < 0)
2686                                die("unable to read %s", sha1_to_hex(s->sha1));
2687                } else {
2688                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2689                        if (!s->data)
2690                                die("unable to read %s", sha1_to_hex(s->sha1));
2691                        s->should_free = 1;
2692                }
2693        }
2694        return 0;
2695}
2696
2697void diff_free_filespec_blob(struct diff_filespec *s)
2698{
2699        if (s->should_free)
2700                free(s->data);
2701        else if (s->should_munmap)
2702                munmap(s->data, s->size);
2703
2704        if (s->should_free || s->should_munmap) {
2705                s->should_free = s->should_munmap = 0;
2706                s->data = NULL;
2707        }
2708}
2709
2710void diff_free_filespec_data(struct diff_filespec *s)
2711{
2712        diff_free_filespec_blob(s);
2713        free(s->cnt_data);
2714        s->cnt_data = NULL;
2715}
2716
2717static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2718                           void *blob,
2719                           unsigned long size,
2720                           const unsigned char *sha1,
2721                           int mode)
2722{
2723        int fd;
2724        struct strbuf buf = STRBUF_INIT;
2725        struct strbuf template = STRBUF_INIT;
2726        char *path_dup = xstrdup(path);
2727        const char *base = basename(path_dup);
2728
2729        /* Generate "XXXXXX_basename.ext" */
2730        strbuf_addstr(&template, "XXXXXX_");
2731        strbuf_addstr(&template, base);
2732
2733        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2734                        strlen(base) + 1);
2735        if (fd < 0)
2736                die_errno("unable to create temp-file");
2737        if (convert_to_working_tree(path,
2738                        (const char *)blob, (size_t)size, &buf)) {
2739                blob = buf.buf;
2740                size = buf.len;
2741        }
2742        if (write_in_full(fd, blob, size) != size)
2743                die_errno("unable to write temp-file");
2744        close(fd);
2745        temp->name = temp->tmp_path;
2746        strcpy(temp->hex, sha1_to_hex(sha1));
2747        temp->hex[40] = 0;
2748        sprintf(temp->mode, "%06o", mode);
2749        strbuf_release(&buf);
2750        strbuf_release(&template);
2751        free(path_dup);
2752}
2753
2754static struct diff_tempfile *prepare_temp_file(const char *name,
2755                struct diff_filespec *one)
2756{
2757        struct diff_tempfile *temp = claim_diff_tempfile();
2758
2759        if (!DIFF_FILE_VALID(one)) {
2760        not_a_valid_file:
2761                /* A '-' entry produces this for file-2, and
2762                 * a '+' entry produces this for file-1.
2763                 */
2764                temp->name = "/dev/null";
2765                strcpy(temp->hex, ".");
2766                strcpy(temp->mode, ".");
2767                return temp;
2768        }
2769
2770        if (!remove_tempfile_installed) {
2771                atexit(remove_tempfile);
2772                sigchain_push_common(remove_tempfile_on_signal);
2773                remove_tempfile_installed = 1;
2774        }
2775
2776        if (!one->sha1_valid ||
2777            reuse_worktree_file(name, one->sha1, 1)) {
2778                struct stat st;
2779                if (lstat(name, &st) < 0) {
2780                        if (errno == ENOENT)
2781                                goto not_a_valid_file;
2782                        die_errno("stat(%s)", name);
2783                }
2784                if (S_ISLNK(st.st_mode)) {
2785                        struct strbuf sb = STRBUF_INIT;
2786                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2787                                die_errno("readlink(%s)", name);
2788                        prep_temp_blob(name, temp, sb.buf, sb.len,
2789                                       (one->sha1_valid ?
2790                                        one->sha1 : null_sha1),
2791                                       (one->sha1_valid ?
2792                                        one->mode : S_IFLNK));
2793                        strbuf_release(&sb);
2794                }
2795                else {
2796                        /* we can borrow from the file in the work tree */
2797                        temp->name = name;
2798                        if (!one->sha1_valid)
2799                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2800                        else
2801                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2802                        /* Even though we may sometimes borrow the
2803                         * contents from the work tree, we always want
2804                         * one->mode.  mode is trustworthy even when
2805                         * !(one->sha1_valid), as long as
2806                         * DIFF_FILE_VALID(one).
2807                         */
2808                        sprintf(temp->mode, "%06o", one->mode);
2809                }
2810                return temp;
2811        }
2812        else {
2813                if (diff_populate_filespec(one, 0))
2814                        die("cannot read data blob for %s", one->path);
2815                prep_temp_blob(name, temp, one->data, one->size,
2816                               one->sha1, one->mode);
2817        }
2818        return temp;
2819}
2820
2821/* An external diff command takes:
2822 *
2823 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2824 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2825 *
2826 */
2827static void run_external_diff(const char *pgm,
2828                              const char *name,
2829                              const char *other,
2830                              struct diff_filespec *one,
2831                              struct diff_filespec *two,
2832                              const char *xfrm_msg,
2833                              int complete_rewrite)
2834{
2835        const char *spawn_arg[10];
2836        int retval;
2837        const char **arg = &spawn_arg[0];
2838
2839        if (one && two) {
2840                struct diff_tempfile *temp_one, *temp_two;
2841                const char *othername = (other ? other : name);
2842                temp_one = prepare_temp_file(name, one);
2843                temp_two = prepare_temp_file(othername, two);
2844                *arg++ = pgm;
2845                *arg++ = name;
2846                *arg++ = temp_one->name;
2847                *arg++ = temp_one->hex;
2848                *arg++ = temp_one->mode;
2849                *arg++ = temp_two->name;
2850                *arg++ = temp_two->hex;
2851                *arg++ = temp_two->mode;
2852                if (other) {
2853                        *arg++ = other;
2854                        *arg++ = xfrm_msg;
2855                }
2856        } else {
2857                *arg++ = pgm;
2858                *arg++ = name;
2859        }
2860        *arg = NULL;
2861        fflush(NULL);
2862        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2863        remove_tempfile();
2864        if (retval) {
2865                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2866                exit(1);
2867        }
2868}
2869
2870static int similarity_index(struct diff_filepair *p)
2871{
2872        return p->score * 100 / MAX_SCORE;
2873}
2874
2875static void fill_metainfo(struct strbuf *msg,
2876                          const char *name,
2877                          const char *other,
2878                          struct diff_filespec *one,
2879                          struct diff_filespec *two,
2880                          struct diff_options *o,
2881                          struct diff_filepair *p,
2882                          int *must_show_header,
2883                          int use_color)
2884{
2885        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2886        const char *reset = diff_get_color(use_color, DIFF_RESET);
2887        struct strbuf *msgbuf;
2888        char *line_prefix = "";
2889
2890        *must_show_header = 1;
2891        if (o->output_prefix) {
2892                msgbuf = o->output_prefix(o, o->output_prefix_data);
2893                line_prefix = msgbuf->buf;
2894        }
2895        strbuf_init(msg, PATH_MAX * 2 + 300);
2896        switch (p->status) {
2897        case DIFF_STATUS_COPIED:
2898                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2899                            line_prefix, set, similarity_index(p));
2900                strbuf_addf(msg, "%s\n%s%scopy from ",
2901                            reset,  line_prefix, set);
2902                quote_c_style(name, msg, NULL, 0);
2903                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2904                quote_c_style(other, msg, NULL, 0);
2905                strbuf_addf(msg, "%s\n", reset);
2906                break;
2907        case DIFF_STATUS_RENAMED:
2908                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2909                            line_prefix, set, similarity_index(p));
2910                strbuf_addf(msg, "%s\n%s%srename from ",
2911                            reset, line_prefix, set);
2912                quote_c_style(name, msg, NULL, 0);
2913                strbuf_addf(msg, "%s\n%s%srename to ",
2914                            reset, line_prefix, set);
2915                quote_c_style(other, msg, NULL, 0);
2916                strbuf_addf(msg, "%s\n", reset);
2917                break;
2918        case DIFF_STATUS_MODIFIED:
2919                if (p->score) {
2920                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2921                                    line_prefix,
2922                                    set, similarity_index(p), reset);
2923                        break;
2924                }
2925                /* fallthru */
2926        default:
2927                *must_show_header = 0;
2928        }
2929        if (one && two && hashcmp(one->sha1, two->sha1)) {
2930                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2931
2932                if (DIFF_OPT_TST(o, BINARY)) {
2933                        mmfile_t mf;
2934                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2935                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2936                                abbrev = 40;
2937                }
2938                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2939                            find_unique_abbrev(one->sha1, abbrev));
2940                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2941                if (one->mode == two->mode)
2942                        strbuf_addf(msg, " %06o", one->mode);
2943                strbuf_addf(msg, "%s\n", reset);
2944        }
2945}
2946
2947static void run_diff_cmd(const char *pgm,
2948                         const char *name,
2949                         const char *other,
2950                         const char *attr_path,
2951                         struct diff_filespec *one,
2952                         struct diff_filespec *two,
2953                         struct strbuf *msg,
2954                         struct diff_options *o,
2955                         struct diff_filepair *p)
2956{
2957        const char *xfrm_msg = NULL;
2958        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2959        int must_show_header = 0;
2960
2961        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2962                pgm = NULL;
2963        else {
2964                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2965                if (drv && drv->external)
2966                        pgm = drv->external;
2967        }
2968
2969        if (msg) {
2970                /*
2971                 * don't use colors when the header is intended for an
2972                 * external diff driver
2973                 */
2974                fill_metainfo(msg, name, other, one, two, o, p,
2975                              &must_show_header,
2976                              want_color(o->use_color) && !pgm);
2977                xfrm_msg = msg->len ? msg->buf : NULL;
2978        }
2979
2980        if (pgm) {
2981                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2982                                  complete_rewrite);
2983                return;
2984        }
2985        if (one && two)
2986                builtin_diff(name, other ? other : name,
2987                             one, two, xfrm_msg, must_show_header,
2988                             o, complete_rewrite);
2989        else
2990                fprintf(o->file, "* Unmerged path %s\n", name);
2991}
2992
2993static void diff_fill_sha1_info(struct diff_filespec *one)
2994{
2995        if (DIFF_FILE_VALID(one)) {
2996                if (!one->sha1_valid) {
2997                        struct stat st;
2998                        if (!strcmp(one->path, "-")) {
2999                                hashcpy(one->sha1, null_sha1);
3000                                return;
3001                        }
3002                        if (lstat(one->path, &st) < 0)
3003                                die_errno("stat '%s'", one->path);
3004                        if (index_path(one->sha1, one->path, &st, 0))
3005                                die("cannot hash %s", one->path);
3006                }
3007        }
3008        else
3009                hashclr(one->sha1);
3010}
3011
3012static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3013{
3014        /* Strip the prefix but do not molest /dev/null and absolute paths */
3015        if (*namep && **namep != '/') {
3016                *namep += prefix_length;
3017                if (**namep == '/')
3018                        ++*namep;
3019        }
3020        if (*otherp && **otherp != '/') {
3021                *otherp += prefix_length;
3022                if (**otherp == '/')
3023                        ++*otherp;
3024        }
3025}
3026
3027static void run_diff(struct diff_filepair *p, struct diff_options *o)
3028{
3029        const char *pgm = external_diff();
3030        struct strbuf msg;
3031        struct diff_filespec *one = p->one;
3032        struct diff_filespec *two = p->two;
3033        const char *name;
3034        const char *other;
3035        const char *attr_path;
3036
3037        name  = p->one->path;
3038        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3039        attr_path = name;
3040        if (o->prefix_length)
3041                strip_prefix(o->prefix_length, &name, &other);
3042
3043        if (DIFF_PAIR_UNMERGED(p)) {
3044                run_diff_cmd(pgm, name, NULL, attr_path,
3045                             NULL, NULL, NULL, o, p);
3046                return;
3047        }
3048
3049        diff_fill_sha1_info(one);
3050        diff_fill_sha1_info(two);
3051
3052        if (!pgm &&
3053            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3054            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3055                /*
3056                 * a filepair that changes between file and symlink
3057                 * needs to be split into deletion and creation.
3058                 */
3059                struct diff_filespec *null = alloc_filespec(two->path);
3060                run_diff_cmd(NULL, name, other, attr_path,
3061                             one, null, &msg, o, p);
3062                free(null);
3063                strbuf_release(&msg);
3064
3065                null = alloc_filespec(one->path);
3066                run_diff_cmd(NULL, name, other, attr_path,
3067                             null, two, &msg, o, p);
3068                free(null);
3069        }
3070        else
3071                run_diff_cmd(pgm, name, other, attr_path,
3072                             one, two, &msg, o, p);
3073
3074        strbuf_release(&msg);
3075}
3076
3077static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3078                         struct diffstat_t *diffstat)
3079{
3080        const char *name;
3081        const char *other;
3082        int complete_rewrite = 0;
3083
3084        if (DIFF_PAIR_UNMERGED(p)) {
3085                /* unmerged */
3086                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
3087                return;
3088        }
3089
3090        name = p->one->path;
3091        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3092
3093        if (o->prefix_length)
3094                strip_prefix(o->prefix_length, &name, &other);
3095
3096        diff_fill_sha1_info(p->one);
3097        diff_fill_sha1_info(p->two);
3098
3099        if (p->status == DIFF_STATUS_MODIFIED && p->score)
3100                complete_rewrite = 1;
3101        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
3102}
3103
3104static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3105{
3106        const char *name;
3107        const char *other;
3108        const char *attr_path;
3109
3110        if (DIFF_PAIR_UNMERGED(p)) {
3111                /* unmerged */
3112                return;
3113        }
3114
3115        name = p->one->path;
3116        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3117        attr_path = other ? other : name;
3118
3119        if (o->prefix_length)
3120                strip_prefix(o->prefix_length, &name, &other);
3121
3122        diff_fill_sha1_info(p->one);
3123        diff_fill_sha1_info(p->two);
3124
3125        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3126}
3127
3128void diff_setup(struct diff_options *options)
3129{
3130        memcpy(options, &default_diff_options, sizeof(*options));
3131
3132        options->file = stdout;
3133
3134        options->line_termination = '\n';
3135        options->break_opt = -1;
3136        options->rename_limit = -1;
3137        options->dirstat_permille = diff_dirstat_permille_default;
3138        options->context = 3;
3139
3140        options->change = diff_change;
3141        options->add_remove = diff_addremove;
3142        options->use_color = diff_use_color_default;
3143        options->detect_rename = diff_detect_rename_default;
3144
3145        if (diff_no_prefix) {
3146                options->a_prefix = options->b_prefix = "";
3147        } else if (!diff_mnemonic_prefix) {
3148                options->a_prefix = "a/";
3149                options->b_prefix = "b/";
3150        }
3151}
3152
3153int diff_setup_done(struct diff_options *options)
3154{
3155        int count = 0;
3156
3157        if (options->output_format & DIFF_FORMAT_NAME)
3158                count++;
3159        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3160                count++;
3161        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3162                count++;
3163        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3164                count++;
3165        if (count > 1)
3166                die("--name-only, --name-status, --check and -s are mutually exclusive");
3167
3168        /*
3169         * Most of the time we can say "there are changes"
3170         * only by checking if there are changed paths, but
3171         * --ignore-whitespace* options force us to look
3172         * inside contents.
3173         */
3174
3175        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3176            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3177            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3178                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3179        else
3180                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3181
3182        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3183                options->detect_rename = DIFF_DETECT_COPY;
3184
3185        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3186                options->prefix = NULL;
3187        if (options->prefix)
3188                options->prefix_length = strlen(options->prefix);
3189        else
3190                options->prefix_length = 0;
3191
3192        if (options->output_format & (DIFF_FORMAT_NAME |
3193                                      DIFF_FORMAT_NAME_STATUS |
3194                                      DIFF_FORMAT_CHECKDIFF |
3195                                      DIFF_FORMAT_NO_OUTPUT))
3196                options->output_format &= ~(DIFF_FORMAT_RAW |
3197                                            DIFF_FORMAT_NUMSTAT |
3198                                            DIFF_FORMAT_DIFFSTAT |
3199                                            DIFF_FORMAT_SHORTSTAT |
3200                                            DIFF_FORMAT_DIRSTAT |
3201                                            DIFF_FORMAT_SUMMARY |
3202                                            DIFF_FORMAT_PATCH);
3203
3204        /*
3205         * These cases always need recursive; we do not drop caller-supplied
3206         * recursive bits for other formats here.
3207         */
3208        if (options->output_format & (DIFF_FORMAT_PATCH |
3209                                      DIFF_FORMAT_NUMSTAT |
3210                                      DIFF_FORMAT_DIFFSTAT |
3211                                      DIFF_FORMAT_SHORTSTAT |
3212                                      DIFF_FORMAT_DIRSTAT |
3213                                      DIFF_FORMAT_SUMMARY |
3214                                      DIFF_FORMAT_CHECKDIFF))
3215                DIFF_OPT_SET(options, RECURSIVE);
3216        /*
3217         * Also pickaxe would not work very well if you do not say recursive
3218         */
3219        if (options->pickaxe)
3220                DIFF_OPT_SET(options, RECURSIVE);
3221        /*
3222         * When patches are generated, submodules diffed against the work tree
3223         * must be checked for dirtiness too so it can be shown in the output
3224         */
3225        if (options->output_format & DIFF_FORMAT_PATCH)
3226                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3227
3228        if (options->detect_rename && options->rename_limit < 0)
3229                options->rename_limit = diff_rename_limit_default;
3230        if (options->setup & DIFF_SETUP_USE_CACHE) {
3231                if (!active_cache)
3232                        /* read-cache does not die even when it fails
3233                         * so it is safe for us to do this here.  Also
3234                         * it does not smudge active_cache or active_nr
3235                         * when it fails, so we do not have to worry about
3236                         * cleaning it up ourselves either.
3237                         */
3238                        read_cache();
3239        }
3240        if (options->abbrev <= 0 || 40 < options->abbrev)
3241                options->abbrev = 40; /* full */
3242
3243        /*
3244         * It does not make sense to show the first hit we happened
3245         * to have found.  It does not make sense not to return with
3246         * exit code in such a case either.
3247         */
3248        if (DIFF_OPT_TST(options, QUICK)) {
3249                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3250                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3251        }
3252
3253        return 0;
3254}
3255
3256static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3257{
3258        char c, *eq;
3259        int len;
3260
3261        if (*arg != '-')
3262                return 0;
3263        c = *++arg;
3264        if (!c)
3265                return 0;
3266        if (c == arg_short) {
3267                c = *++arg;
3268                if (!c)
3269                        return 1;
3270                if (val && isdigit(c)) {
3271                        char *end;
3272                        int n = strtoul(arg, &end, 10);
3273                        if (*end)
3274                                return 0;
3275                        *val = n;
3276                        return 1;
3277                }
3278                return 0;
3279        }
3280        if (c != '-')
3281                return 0;
3282        arg++;
3283        eq = strchr(arg, '=');
3284        if (eq)
3285                len = eq - arg;
3286        else
3287                len = strlen(arg);
3288        if (!len || strncmp(arg, arg_long, len))
3289                return 0;
3290        if (eq) {
3291                int n;
3292                char *end;
3293                if (!isdigit(*++eq))
3294                        return 0;
3295                n = strtoul(eq, &end, 10);
3296                if (*end)
3297                        return 0;
3298                *val = n;
3299        }
3300        return 1;
3301}
3302
3303static int diff_scoreopt_parse(const char *opt);
3304
3305static inline int short_opt(char opt, const char **argv,
3306                            const char **optarg)
3307{
3308        const char *arg = argv[0];
3309        if (arg[0] != '-' || arg[1] != opt)
3310                return 0;
3311        if (arg[2] != '\0') {
3312                *optarg = arg + 2;
3313                return 1;
3314        }
3315        if (!argv[1])
3316                die("Option '%c' requires a value", opt);
3317        *optarg = argv[1];
3318        return 2;
3319}
3320
3321int parse_long_opt(const char *opt, const char **argv,
3322                   const char **optarg)
3323{
3324        const char *arg = argv[0];
3325        if (arg[0] != '-' || arg[1] != '-')
3326                return 0;
3327        arg += strlen("--");
3328        if (prefixcmp(arg, opt))
3329                return 0;
3330        arg += strlen(opt);
3331        if (*arg == '=') { /* sticked form: --option=value */
3332                *optarg = arg + 1;
3333                return 1;
3334        }
3335        if (*arg != '\0')
3336                return 0;
3337        /* separate form: --option value */
3338        if (!argv[1])
3339                die("Option '--%s' requires a value", opt);
3340        *optarg = argv[1];
3341        return 2;
3342}
3343
3344static int stat_opt(struct diff_options *options, const char **av)
3345{
3346        const char *arg = av[0];
3347        char *end;
3348        int width = options->stat_width;
3349        int name_width = options->stat_name_width;
3350        int graph_width = options->stat_graph_width;
3351        int count = options->stat_count;
3352        int argcount = 1;
3353
3354        arg += strlen("--stat");
3355        end = (char *)arg;
3356
3357        switch (*arg) {
3358        case '-':
3359                if (!prefixcmp(arg, "-width")) {
3360                        arg += strlen("-width");
3361                        if (*arg == '=')
3362                                width = strtoul(arg + 1, &end, 10);
3363                        else if (!*arg && !av[1])
3364                                die("Option '--stat-width' requires a value");
3365                        else if (!*arg) {
3366                                width = strtoul(av[1], &end, 10);
3367                                argcount = 2;
3368                        }
3369                } else if (!prefixcmp(arg, "-name-width")) {
3370                        arg += strlen("-name-width");
3371                        if (*arg == '=')
3372                                name_width = strtoul(arg + 1, &end, 10);
3373                        else if (!*arg && !av[1])
3374                                die("Option '--stat-name-width' requires a value");
3375                        else if (!*arg) {
3376                                name_width = strtoul(av[1], &end, 10);
3377                                argcount = 2;
3378                        }
3379                } else if (!prefixcmp(arg, "-graph-width")) {
3380                        arg += strlen("-graph-width");
3381                        if (*arg == '=')
3382                                graph_width = strtoul(arg + 1, &end, 10);
3383                        else if (!*arg && !av[1])
3384                                die("Option '--stat-graph-width' requires a value");
3385                        else if (!*arg) {
3386                                graph_width = strtoul(av[1], &end, 10);
3387                                argcount = 2;
3388                        }
3389                } else if (!prefixcmp(arg, "-count")) {
3390                        arg += strlen("-count");
3391                        if (*arg == '=')
3392                                count = strtoul(arg + 1, &end, 10);
3393                        else if (!*arg && !av[1])
3394                                die("Option '--stat-count' requires a value");
3395                        else if (!*arg) {
3396                                count = strtoul(av[1], &end, 10);
3397                                argcount = 2;
3398                        }
3399                }
3400                break;
3401        case '=':
3402                width = strtoul(arg+1, &end, 10);
3403                if (*end == ',')
3404                        name_width = strtoul(end+1, &end, 10);
3405                if (*end == ',')
3406                        count = strtoul(end+1, &end, 10);
3407        }
3408
3409        /* Important! This checks all the error cases! */
3410        if (*end)
3411                return 0;
3412        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3413        options->stat_name_width = name_width;
3414        options->stat_graph_width = graph_width;
3415        options->stat_width = width;
3416        options->stat_count = count;
3417        return argcount;
3418}
3419
3420static int parse_dirstat_opt(struct diff_options *options, const char *params)
3421{
3422        struct strbuf errmsg = STRBUF_INIT;
3423        if (parse_dirstat_params(options, params, &errmsg))
3424                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3425                    errmsg.buf);
3426        strbuf_release(&errmsg);
3427        /*
3428         * The caller knows a dirstat-related option is given from the command
3429         * line; allow it to say "return this_function();"
3430         */
3431        options->output_format |= DIFF_FORMAT_DIRSTAT;
3432        return 1;
3433}
3434
3435int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3436{
3437        const char *arg = av[0];
3438        const char *optarg;
3439        int argcount;
3440
3441        /* Output format options */
3442        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3443                options->output_format |= DIFF_FORMAT_PATCH;
3444        else if (opt_arg(arg, 'U', "unified", &options->context))
3445                options->output_format |= DIFF_FORMAT_PATCH;
3446        else if (!strcmp(arg, "--raw"))
3447                options->output_format |= DIFF_FORMAT_RAW;
3448        else if (!strcmp(arg, "--patch-with-raw"))
3449                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3450        else if (!strcmp(arg, "--numstat"))
3451                options->output_format |= DIFF_FORMAT_NUMSTAT;
3452        else if (!strcmp(arg, "--shortstat"))
3453                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3454        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3455                return parse_dirstat_opt(options, "");
3456        else if (!prefixcmp(arg, "-X"))
3457                return parse_dirstat_opt(options, arg + 2);
3458        else if (!prefixcmp(arg, "--dirstat="))
3459                return parse_dirstat_opt(options, arg + 10);
3460        else if (!strcmp(arg, "--cumulative"))
3461                return parse_dirstat_opt(options, "cumulative");
3462        else if (!strcmp(arg, "--dirstat-by-file"))
3463                return parse_dirstat_opt(options, "files");
3464        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3465                parse_dirstat_opt(options, "files");
3466                return parse_dirstat_opt(options, arg + 18);
3467        }
3468        else if (!strcmp(arg, "--check"))
3469                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3470        else if (!strcmp(arg, "--summary"))
3471                options->output_format |= DIFF_FORMAT_SUMMARY;
3472        else if (!strcmp(arg, "--patch-with-stat"))
3473                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3474        else if (!strcmp(arg, "--name-only"))
3475                options->output_format |= DIFF_FORMAT_NAME;
3476        else if (!strcmp(arg, "--name-status"))
3477                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3478        else if (!strcmp(arg, "-s"))
3479                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3480        else if (!prefixcmp(arg, "--stat"))
3481                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3482                return stat_opt(options, av);
3483
3484        /* renames options */
3485        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3486                 !strcmp(arg, "--break-rewrites")) {
3487                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3488                        return error("invalid argument to -B: %s", arg+2);
3489        }
3490        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3491                 !strcmp(arg, "--find-renames")) {
3492                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3493                        return error("invalid argument to -M: %s", arg+2);
3494                options->detect_rename = DIFF_DETECT_RENAME;
3495        }
3496        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3497                options->irreversible_delete = 1;
3498        }
3499        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3500                 !strcmp(arg, "--find-copies")) {
3501                if (options->detect_rename == DIFF_DETECT_COPY)
3502                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3503                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3504                        return error("invalid argument to -C: %s", arg+2);
3505                options->detect_rename = DIFF_DETECT_COPY;
3506        }
3507        else if (!strcmp(arg, "--no-renames"))
3508                options->detect_rename = 0;
3509        else if (!strcmp(arg, "--relative"))
3510                DIFF_OPT_SET(options, RELATIVE_NAME);
3511        else if (!prefixcmp(arg, "--relative=")) {
3512                DIFF_OPT_SET(options, RELATIVE_NAME);
3513                options->prefix = arg + 11;
3514        }
3515
3516        /* xdiff options */
3517        else if (!strcmp(arg, "--minimal"))
3518                DIFF_XDL_SET(options, NEED_MINIMAL);
3519        else if (!strcmp(arg, "--no-minimal"))
3520                DIFF_XDL_CLR(options, NEED_MINIMAL);
3521        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3522                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3523        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3524                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3525        else if (!strcmp(arg, "--ignore-space-at-eol"))
3526                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3527        else if (!strcmp(arg, "--patience"))
3528                DIFF_XDL_SET(options, PATIENCE_DIFF);
3529        else if (!strcmp(arg, "--histogram"))
3530                DIFF_XDL_SET(options, HISTOGRAM_DIFF);
3531
3532        /* flags options */
3533        else if (!strcmp(arg, "--binary")) {
3534                options->output_format |= DIFF_FORMAT_PATCH;
3535                DIFF_OPT_SET(options, BINARY);
3536        }
3537        else if (!strcmp(arg, "--full-index"))
3538                DIFF_OPT_SET(options, FULL_INDEX);
3539        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3540                DIFF_OPT_SET(options, TEXT);
3541        else if (!strcmp(arg, "-R"))
3542                DIFF_OPT_SET(options, REVERSE_DIFF);
3543        else if (!strcmp(arg, "--find-copies-harder"))
3544                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3545        else if (!strcmp(arg, "--follow"))
3546                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3547        else if (!strcmp(arg, "--color"))
3548                options->use_color = 1;
3549        else if (!prefixcmp(arg, "--color=")) {
3550                int value = git_config_colorbool(NULL, arg+8);
3551                if (value < 0)
3552                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3553                options->use_color = value;
3554        }
3555        else if (!strcmp(arg, "--no-color"))
3556                options->use_color = 0;
3557        else if (!strcmp(arg, "--color-words")) {
3558                options->use_color = 1;
3559                options->word_diff = DIFF_WORDS_COLOR;
3560        }
3561        else if (!prefixcmp(arg, "--color-words=")) {
3562                options->use_color = 1;
3563                options->word_diff = DIFF_WORDS_COLOR;
3564                options->word_regex = arg + 14;
3565        }
3566        else if (!strcmp(arg, "--word-diff")) {
3567                if (options->word_diff == DIFF_WORDS_NONE)
3568                        options->word_diff = DIFF_WORDS_PLAIN;
3569        }
3570        else if (!prefixcmp(arg, "--word-diff=")) {
3571                const char *type = arg + 12;
3572                if (!strcmp(type, "plain"))
3573                        options->word_diff = DIFF_WORDS_PLAIN;
3574                else if (!strcmp(type, "color")) {
3575                        options->use_color = 1;
3576                        options->word_diff = DIFF_WORDS_COLOR;
3577                }
3578                else if (!strcmp(type, "porcelain"))
3579                        options->word_diff = DIFF_WORDS_PORCELAIN;
3580                else if (!strcmp(type, "none"))
3581                        options->word_diff = DIFF_WORDS_NONE;
3582                else
3583                        die("bad --word-diff argument: %s", type);
3584        }
3585        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3586                if (options->word_diff == DIFF_WORDS_NONE)
3587                        options->word_diff = DIFF_WORDS_PLAIN;
3588                options->word_regex = optarg;
3589                return argcount;
3590        }
3591        else if (!strcmp(arg, "--exit-code"))
3592                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3593        else if (!strcmp(arg, "--quiet"))
3594                DIFF_OPT_SET(options, QUICK);
3595        else if (!strcmp(arg, "--ext-diff"))
3596                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3597        else if (!strcmp(arg, "--no-ext-diff"))
3598                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3599        else if (!strcmp(arg, "--textconv"))
3600                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3601        else if (!strcmp(arg, "--no-textconv"))
3602                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3603        else if (!strcmp(arg, "--ignore-submodules")) {
3604                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3605                handle_ignore_submodules_arg(options, "all");
3606        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3607                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3608                handle_ignore_submodules_arg(options, arg + 20);
3609        } else if (!strcmp(arg, "--submodule"))
3610                DIFF_OPT_SET(options, SUBMODULE_LOG);
3611        else if (!prefixcmp(arg, "--submodule=")) {
3612                if (!strcmp(arg + 12, "log"))
3613                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3614        }
3615
3616        /* misc options */
3617        else if (!strcmp(arg, "-z"))
3618                options->line_termination = 0;
3619        else if ((argcount = short_opt('l', av, &optarg))) {
3620                options->rename_limit = strtoul(optarg, NULL, 10);
3621                return argcount;
3622        }
3623        else if ((argcount = short_opt('S', av, &optarg))) {
3624                options->pickaxe = optarg;
3625                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3626                return argcount;
3627        } else if ((argcount = short_opt('G', av, &optarg))) {
3628                options->pickaxe = optarg;
3629                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3630                return argcount;
3631        }
3632        else if (!strcmp(arg, "--pickaxe-all"))
3633                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3634        else if (!strcmp(arg, "--pickaxe-regex"))
3635                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3636        else if ((argcount = short_opt('O', av, &optarg))) {
3637                options->orderfile = optarg;
3638                return argcount;
3639        }
3640        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3641                options->filter = optarg;
3642                return argcount;
3643        }
3644        else if (!strcmp(arg, "--abbrev"))
3645                options->abbrev = DEFAULT_ABBREV;
3646        else if (!prefixcmp(arg, "--abbrev=")) {
3647                options->abbrev = strtoul(arg + 9, NULL, 10);
3648                if (options->abbrev < MINIMUM_ABBREV)
3649                        options->abbrev = MINIMUM_ABBREV;
3650                else if (40 < options->abbrev)
3651                        options->abbrev = 40;
3652        }
3653        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3654                options->a_prefix = optarg;
3655                return argcount;
3656        }
3657        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3658                options->b_prefix = optarg;
3659                return argcount;
3660        }
3661        else if (!strcmp(arg, "--no-prefix"))
3662                options->a_prefix = options->b_prefix = "";
3663        else if (opt_arg(arg, '\0', "inter-hunk-context",
3664                         &options->interhunkcontext))
3665                ;
3666        else if (!strcmp(arg, "-W"))
3667                DIFF_OPT_SET(options, FUNCCONTEXT);
3668        else if (!strcmp(arg, "--function-context"))
3669                DIFF_OPT_SET(options, FUNCCONTEXT);
3670        else if (!strcmp(arg, "--no-function-context"))
3671                DIFF_OPT_CLR(options, FUNCCONTEXT);
3672        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3673                options->file = fopen(optarg, "w");
3674                if (!options->file)
3675                        die_errno("Could not open '%s'", optarg);
3676                options->close_file = 1;
3677                return argcount;
3678        } else
3679                return 0;
3680        return 1;
3681}
3682
3683int parse_rename_score(const char **cp_p)
3684{
3685        unsigned long num, scale;
3686        int ch, dot;
3687        const char *cp = *cp_p;
3688
3689        num = 0;
3690        scale = 1;
3691        dot = 0;
3692        for (;;) {
3693                ch = *cp;
3694                if ( !dot && ch == '.' ) {
3695                        scale = 1;
3696                        dot = 1;
3697                } else if ( ch == '%' ) {
3698                        scale = dot ? scale*100 : 100;
3699                        cp++;   /* % is always at the end */
3700                        break;
3701                } else if ( ch >= '0' && ch <= '9' ) {
3702                        if ( scale < 100000 ) {
3703                                scale *= 10;
3704                                num = (num*10) + (ch-'0');
3705                        }
3706                } else {
3707                        break;
3708                }
3709                cp++;
3710        }
3711        *cp_p = cp;
3712
3713        /* user says num divided by scale and we say internally that
3714         * is MAX_SCORE * num / scale.
3715         */
3716        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3717}
3718
3719static int diff_scoreopt_parse(const char *opt)
3720{
3721        int opt1, opt2, cmd;
3722
3723        if (*opt++ != '-')
3724                return -1;
3725        cmd = *opt++;
3726        if (cmd == '-') {
3727                /* convert the long-form arguments into short-form versions */
3728                if (!prefixcmp(opt, "break-rewrites")) {
3729                        opt += strlen("break-rewrites");
3730                        if (*opt == 0 || *opt++ == '=')
3731                                cmd = 'B';
3732                } else if (!prefixcmp(opt, "find-copies")) {
3733                        opt += strlen("find-copies");
3734                        if (*opt == 0 || *opt++ == '=')
3735                                cmd = 'C';
3736                } else if (!prefixcmp(opt, "find-renames")) {
3737                        opt += strlen("find-renames");
3738                        if (*opt == 0 || *opt++ == '=')
3739                                cmd = 'M';
3740                }
3741        }
3742        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3743                return -1; /* that is not a -M, -C nor -B option */
3744
3745        opt1 = parse_rename_score(&opt);
3746        if (cmd != 'B')
3747                opt2 = 0;
3748        else {
3749                if (*opt == 0)
3750                        opt2 = 0;
3751                else if (*opt != '/')
3752                        return -1; /* we expect -B80/99 or -B80 */
3753                else {
3754                        opt++;
3755                        opt2 = parse_rename_score(&opt);
3756                }
3757        }
3758        if (*opt != 0)
3759                return -1;
3760        return opt1 | (opt2 << 16);
3761}
3762
3763struct diff_queue_struct diff_queued_diff;
3764
3765void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3766{
3767        if (queue->alloc <= queue->nr) {
3768                queue->alloc = alloc_nr(queue->alloc);
3769                queue->queue = xrealloc(queue->queue,
3770                                        sizeof(dp) * queue->alloc);
3771        }
3772        queue->queue[queue->nr++] = dp;
3773}
3774
3775struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3776                                 struct diff_filespec *one,
3777                                 struct diff_filespec *two)
3778{
3779        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3780        dp->one = one;
3781        dp->two = two;
3782        if (queue)
3783                diff_q(queue, dp);
3784        return dp;
3785}
3786
3787void diff_free_filepair(struct diff_filepair *p)
3788{
3789        free_filespec(p->one);
3790        free_filespec(p->two);
3791        free(p);
3792}
3793
3794/* This is different from find_unique_abbrev() in that
3795 * it stuffs the result with dots for alignment.
3796 */
3797const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3798{
3799        int abblen;
3800        const char *abbrev;
3801        if (len == 40)
3802                return sha1_to_hex(sha1);
3803
3804        abbrev = find_unique_abbrev(sha1, len);
3805        abblen = strlen(abbrev);
3806        if (abblen < 37) {
3807                static char hex[41];
3808                if (len < abblen && abblen <= len + 2)
3809                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3810                else
3811                        sprintf(hex, "%s...", abbrev);
3812                return hex;
3813        }
3814        return sha1_to_hex(sha1);
3815}
3816
3817static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3818{
3819        int line_termination = opt->line_termination;
3820        int inter_name_termination = line_termination ? '\t' : '\0';
3821        if (opt->output_prefix) {
3822                struct strbuf *msg = NULL;
3823                msg = opt->output_prefix(opt, opt->output_prefix_data);
3824                fprintf(opt->file, "%s", msg->buf);
3825        }
3826
3827        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3828                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3829                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3830                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3831        }
3832        if (p->score) {
3833                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3834                        inter_name_termination);
3835        } else {
3836                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3837        }
3838
3839        if (p->status == DIFF_STATUS_COPIED ||
3840            p->status == DIFF_STATUS_RENAMED) {
3841                const char *name_a, *name_b;
3842                name_a = p->one->path;
3843                name_b = p->two->path;
3844                strip_prefix(opt->prefix_length, &name_a, &name_b);
3845                write_name_quoted(name_a, opt->file, inter_name_termination);
3846                write_name_quoted(name_b, opt->file, line_termination);
3847        } else {
3848                const char *name_a, *name_b;
3849                name_a = p->one->mode ? p->one->path : p->two->path;
3850                name_b = NULL;
3851                strip_prefix(opt->prefix_length, &name_a, &name_b);
3852                write_name_quoted(name_a, opt->file, line_termination);
3853        }
3854}
3855
3856int diff_unmodified_pair(struct diff_filepair *p)
3857{
3858        /* This function is written stricter than necessary to support
3859         * the currently implemented transformers, but the idea is to
3860         * let transformers to produce diff_filepairs any way they want,
3861         * and filter and clean them up here before producing the output.
3862         */
3863        struct diff_filespec *one = p->one, *two = p->two;
3864
3865        if (DIFF_PAIR_UNMERGED(p))
3866                return 0; /* unmerged is interesting */
3867
3868        /* deletion, addition, mode or type change
3869         * and rename are all interesting.
3870         */
3871        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3872            DIFF_PAIR_MODE_CHANGED(p) ||
3873            strcmp(one->path, two->path))
3874                return 0;
3875
3876        /* both are valid and point at the same path.  that is, we are
3877         * dealing with a change.
3878         */
3879        if (one->sha1_valid && two->sha1_valid &&
3880            !hashcmp(one->sha1, two->sha1) &&
3881            !one->dirty_submodule && !two->dirty_submodule)
3882                return 1; /* no change */
3883        if (!one->sha1_valid && !two->sha1_valid)
3884                return 1; /* both look at the same file on the filesystem. */
3885        return 0;
3886}
3887
3888static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3889{
3890        if (diff_unmodified_pair(p))
3891                return;
3892
3893        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3894            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3895                return; /* no tree diffs in patch format */
3896
3897        run_diff(p, o);
3898}
3899
3900static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3901                            struct diffstat_t *diffstat)
3902{
3903        if (diff_unmodified_pair(p))
3904                return;
3905
3906        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3907            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3908                return; /* no useful stat for tree diffs */
3909
3910        run_diffstat(p, o, diffstat);
3911}
3912
3913static void diff_flush_checkdiff(struct diff_filepair *p,
3914                struct diff_options *o)
3915{
3916        if (diff_unmodified_pair(p))
3917                return;
3918
3919        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3920            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3921                return; /* nothing to check in tree diffs */
3922
3923        run_checkdiff(p, o);
3924}
3925
3926int diff_queue_is_empty(void)
3927{
3928        struct diff_queue_struct *q = &diff_queued_diff;
3929        int i;
3930        for (i = 0; i < q->nr; i++)
3931                if (!diff_unmodified_pair(q->queue[i]))
3932                        return 0;
3933        return 1;
3934}
3935
3936#if DIFF_DEBUG
3937void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3938{
3939        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3940                x, one ? one : "",
3941                s->path,
3942                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3943                s->mode,
3944                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3945        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3946                x, one ? one : "",
3947                s->size, s->xfrm_flags);
3948}
3949
3950void diff_debug_filepair(const struct diff_filepair *p, int i)
3951{
3952        diff_debug_filespec(p->one, i, "one");
3953        diff_debug_filespec(p->two, i, "two");
3954        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3955                p->score, p->status ? p->status : '?',
3956                p->one->rename_used, p->broken_pair);
3957}
3958
3959void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3960{
3961        int i;
3962        if (msg)
3963                fprintf(stderr, "%s\n", msg);
3964        fprintf(stderr, "q->nr = %d\n", q->nr);
3965        for (i = 0; i < q->nr; i++) {
3966                struct diff_filepair *p = q->queue[i];
3967                diff_debug_filepair(p, i);
3968        }
3969}
3970#endif
3971
3972static void diff_resolve_rename_copy(void)
3973{
3974        int i;
3975        struct diff_filepair *p;
3976        struct diff_queue_struct *q = &diff_queued_diff;
3977
3978        diff_debug_queue("resolve-rename-copy", q);
3979
3980        for (i = 0; i < q->nr; i++) {
3981                p = q->queue[i];
3982                p->status = 0; /* undecided */
3983                if (DIFF_PAIR_UNMERGED(p))
3984                        p->status = DIFF_STATUS_UNMERGED;
3985                else if (!DIFF_FILE_VALID(p->one))
3986                        p->status = DIFF_STATUS_ADDED;
3987                else if (!DIFF_FILE_VALID(p->two))
3988                        p->status = DIFF_STATUS_DELETED;
3989                else if (DIFF_PAIR_TYPE_CHANGED(p))
3990                        p->status = DIFF_STATUS_TYPE_CHANGED;
3991
3992                /* from this point on, we are dealing with a pair
3993                 * whose both sides are valid and of the same type, i.e.
3994                 * either in-place edit or rename/copy edit.
3995                 */
3996                else if (DIFF_PAIR_RENAME(p)) {
3997                        /*
3998                         * A rename might have re-connected a broken
3999                         * pair up, causing the pathnames to be the
4000                         * same again. If so, that's not a rename at
4001                         * all, just a modification..
4002                         *
4003                         * Otherwise, see if this source was used for
4004                         * multiple renames, in which case we decrement
4005                         * the count, and call it a copy.
4006                         */
4007                        if (!strcmp(p->one->path, p->two->path))
4008                                p->status = DIFF_STATUS_MODIFIED;
4009                        else if (--p->one->rename_used > 0)
4010                                p->status = DIFF_STATUS_COPIED;
4011                        else
4012                                p->status = DIFF_STATUS_RENAMED;
4013                }
4014                else if (hashcmp(p->one->sha1, p->two->sha1) ||
4015                         p->one->mode != p->two->mode ||
4016                         p->one->dirty_submodule ||
4017                         p->two->dirty_submodule ||
4018                         is_null_sha1(p->one->sha1))
4019                        p->status = DIFF_STATUS_MODIFIED;
4020                else {
4021                        /* This is a "no-change" entry and should not
4022                         * happen anymore, but prepare for broken callers.
4023                         */
4024                        error("feeding unmodified %s to diffcore",
4025                              p->one->path);
4026                        p->status = DIFF_STATUS_UNKNOWN;
4027                }
4028        }
4029        diff_debug_queue("resolve-rename-copy done", q);
4030}
4031
4032static int check_pair_status(struct diff_filepair *p)
4033{
4034        switch (p->status) {
4035        case DIFF_STATUS_UNKNOWN:
4036                return 0;
4037        case 0:
4038                die("internal error in diff-resolve-rename-copy");
4039        default:
4040                return 1;
4041        }
4042}
4043
4044static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4045{
4046        int fmt = opt->output_format;
4047
4048        if (fmt & DIFF_FORMAT_CHECKDIFF)
4049                diff_flush_checkdiff(p, opt);
4050        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4051                diff_flush_raw(p, opt);
4052        else if (fmt & DIFF_FORMAT_NAME) {
4053                const char *name_a, *name_b;
4054                name_a = p->two->path;
4055                name_b = NULL;
4056                strip_prefix(opt->prefix_length, &name_a, &name_b);
4057                write_name_quoted(name_a, opt->file, opt->line_termination);
4058        }
4059}
4060
4061static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4062{
4063        if (fs->mode)
4064                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4065        else
4066                fprintf(file, " %s ", newdelete);
4067        write_name_quoted(fs->path, file, '\n');
4068}
4069
4070
4071static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4072                const char *line_prefix)
4073{
4074        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4075                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4076                        p->two->mode, show_name ? ' ' : '\n');
4077                if (show_name) {
4078                        write_name_quoted(p->two->path, file, '\n');
4079                }
4080        }
4081}
4082
4083static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4084                        const char *line_prefix)
4085{
4086        char *names = pprint_rename(p->one->path, p->two->path);
4087
4088        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4089        free(names);
4090        show_mode_change(file, p, 0, line_prefix);
4091}
4092
4093static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4094{
4095        FILE *file = opt->file;
4096        char *line_prefix = "";
4097
4098        if (opt->output_prefix) {
4099                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
4100                line_prefix = buf->buf;
4101        }
4102
4103        switch(p->status) {
4104        case DIFF_STATUS_DELETED:
4105                fputs(line_prefix, file);
4106                show_file_mode_name(file, "delete", p->one);
4107                break;
4108        case DIFF_STATUS_ADDED:
4109                fputs(line_prefix, file);
4110                show_file_mode_name(file, "create", p->two);
4111                break;
4112        case DIFF_STATUS_COPIED:
4113                fputs(line_prefix, file);
4114                show_rename_copy(file, "copy", p, line_prefix);
4115                break;
4116        case DIFF_STATUS_RENAMED:
4117                fputs(line_prefix, file);
4118                show_rename_copy(file, "rename", p, line_prefix);
4119                break;
4120        default:
4121                if (p->score) {
4122                        fprintf(file, "%s rewrite ", line_prefix);
4123                        write_name_quoted(p->two->path, file, ' ');
4124                        fprintf(file, "(%d%%)\n", similarity_index(p));
4125                }
4126                show_mode_change(file, p, !p->score, line_prefix);
4127                break;
4128        }
4129}
4130
4131struct patch_id_t {
4132        git_SHA_CTX *ctx;
4133        int patchlen;
4134};
4135
4136static int remove_space(char *line, int len)
4137{
4138        int i;
4139        char *dst = line;
4140        unsigned char c;
4141
4142        for (i = 0; i < len; i++)
4143                if (!isspace((c = line[i])))
4144                        *dst++ = c;
4145
4146        return dst - line;
4147}
4148
4149static void patch_id_consume(void *priv, char *line, unsigned long len)
4150{
4151        struct patch_id_t *data = priv;
4152        int new_len;
4153
4154        /* Ignore line numbers when computing the SHA1 of the patch */
4155        if (!prefixcmp(line, "@@ -"))
4156                return;
4157
4158        new_len = remove_space(line, len);
4159
4160        git_SHA1_Update(data->ctx, line, new_len);
4161        data->patchlen += new_len;
4162}
4163
4164/* returns 0 upon success, and writes result into sha1 */
4165static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4166{
4167        struct diff_queue_struct *q = &diff_queued_diff;
4168        int i;
4169        git_SHA_CTX ctx;
4170        struct patch_id_t data;
4171        char buffer[PATH_MAX * 4 + 20];
4172
4173        git_SHA1_Init(&ctx);
4174        memset(&data, 0, sizeof(struct patch_id_t));
4175        data.ctx = &ctx;
4176
4177        for (i = 0; i < q->nr; i++) {
4178                xpparam_t xpp;
4179                xdemitconf_t xecfg;
4180                mmfile_t mf1, mf2;
4181                struct diff_filepair *p = q->queue[i];
4182                int len1, len2;
4183
4184                memset(&xpp, 0, sizeof(xpp));
4185                memset(&xecfg, 0, sizeof(xecfg));
4186                if (p->status == 0)
4187                        return error("internal diff status error");
4188                if (p->status == DIFF_STATUS_UNKNOWN)
4189                        continue;
4190                if (diff_unmodified_pair(p))
4191                        continue;
4192                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4193                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4194                        continue;
4195                if (DIFF_PAIR_UNMERGED(p))
4196                        continue;
4197
4198                diff_fill_sha1_info(p->one);
4199                diff_fill_sha1_info(p->two);
4200                if (fill_mmfile(&mf1, p->one) < 0 ||
4201                                fill_mmfile(&mf2, p->two) < 0)
4202                        return error("unable to read files to diff");
4203
4204                len1 = remove_space(p->one->path, strlen(p->one->path));
4205                len2 = remove_space(p->two->path, strlen(p->two->path));
4206                if (p->one->mode == 0)
4207                        len1 = snprintf(buffer, sizeof(buffer),
4208                                        "diff--gita/%.*sb/%.*s"
4209                                        "newfilemode%06o"
4210                                        "---/dev/null"
4211                                        "+++b/%.*s",
4212                                        len1, p->one->path,
4213                                        len2, p->two->path,
4214                                        p->two->mode,
4215                                        len2, p->two->path);
4216                else if (p->two->mode == 0)
4217                        len1 = snprintf(buffer, sizeof(buffer),
4218                                        "diff--gita/%.*sb/%.*s"
4219                                        "deletedfilemode%06o"
4220                                        "---a/%.*s"
4221                                        "+++/dev/null",
4222                                        len1, p->one->path,
4223                                        len2, p->two->path,
4224                                        p->one->mode,
4225                                        len1, p->one->path);
4226                else
4227                        len1 = snprintf(buffer, sizeof(buffer),
4228                                        "diff--gita/%.*sb/%.*s"
4229                                        "---a/%.*s"
4230                                        "+++b/%.*s",
4231                                        len1, p->one->path,
4232                                        len2, p->two->path,
4233                                        len1, p->one->path,
4234                                        len2, p->two->path);
4235                git_SHA1_Update(&ctx, buffer, len1);
4236
4237                if (diff_filespec_is_binary(p->one) ||
4238                    diff_filespec_is_binary(p->two)) {
4239                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4240                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4241                        continue;
4242                }
4243
4244                xpp.flags = 0;
4245                xecfg.ctxlen = 3;
4246                xecfg.flags = 0;
4247                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4248                              &xpp, &xecfg);
4249        }
4250
4251        git_SHA1_Final(sha1, &ctx);
4252        return 0;
4253}
4254
4255int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4256{
4257        struct diff_queue_struct *q = &diff_queued_diff;
4258        int i;
4259        int result = diff_get_patch_id(options, sha1);
4260
4261        for (i = 0; i < q->nr; i++)
4262                diff_free_filepair(q->queue[i]);
4263
4264        free(q->queue);
4265        DIFF_QUEUE_CLEAR(q);
4266
4267        return result;
4268}
4269
4270static int is_summary_empty(const struct diff_queue_struct *q)
4271{
4272        int i;
4273
4274        for (i = 0; i < q->nr; i++) {
4275                const struct diff_filepair *p = q->queue[i];
4276
4277                switch (p->status) {
4278                case DIFF_STATUS_DELETED:
4279                case DIFF_STATUS_ADDED:
4280                case DIFF_STATUS_COPIED:
4281                case DIFF_STATUS_RENAMED:
4282                        return 0;
4283                default:
4284                        if (p->score)
4285                                return 0;
4286                        if (p->one->mode && p->two->mode &&
4287                            p->one->mode != p->two->mode)
4288                                return 0;
4289                        break;
4290                }
4291        }
4292        return 1;
4293}
4294
4295static const char rename_limit_warning[] =
4296"inexact rename detection was skipped due to too many files.";
4297
4298static const char degrade_cc_to_c_warning[] =
4299"only found copies from modified paths due to too many files.";
4300
4301static const char rename_limit_advice[] =
4302"you may want to set your %s variable to at least "
4303"%d and retry the command.";
4304
4305void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4306{
4307        if (degraded_cc)
4308                warning(degrade_cc_to_c_warning);
4309        else if (needed)
4310                warning(rename_limit_warning);
4311        else
4312                return;
4313        if (0 < needed && needed < 32767)
4314                warning(rename_limit_advice, varname, needed);
4315}
4316
4317void diff_flush(struct diff_options *options)
4318{
4319        struct diff_queue_struct *q = &diff_queued_diff;
4320        int i, output_format = options->output_format;
4321        int separator = 0;
4322        int dirstat_by_line = 0;
4323
4324        /*
4325         * Order: raw, stat, summary, patch
4326         * or:    name/name-status/checkdiff (other bits clear)
4327         */
4328        if (!q->nr)
4329                goto free_queue;
4330
4331        if (output_format & (DIFF_FORMAT_RAW |
4332                             DIFF_FORMAT_NAME |
4333                             DIFF_FORMAT_NAME_STATUS |
4334                             DIFF_FORMAT_CHECKDIFF)) {
4335                for (i = 0; i < q->nr; i++) {
4336                        struct diff_filepair *p = q->queue[i];
4337                        if (check_pair_status(p))
4338                                flush_one_pair(p, options);
4339                }
4340                separator++;
4341        }
4342
4343        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4344                dirstat_by_line = 1;
4345
4346        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4347            dirstat_by_line) {
4348                struct diffstat_t diffstat;
4349
4350                memset(&diffstat, 0, sizeof(struct diffstat_t));
4351                for (i = 0; i < q->nr; i++) {
4352                        struct diff_filepair *p = q->queue[i];
4353                        if (check_pair_status(p))
4354                                diff_flush_stat(p, options, &diffstat);
4355                }
4356                if (output_format & DIFF_FORMAT_NUMSTAT)
4357                        show_numstat(&diffstat, options);
4358                if (output_format & DIFF_FORMAT_DIFFSTAT)
4359                        show_stats(&diffstat, options);
4360                if (output_format & DIFF_FORMAT_SHORTSTAT)
4361                        show_shortstats(&diffstat, options);
4362                if (output_format & DIFF_FORMAT_DIRSTAT)
4363                        show_dirstat_by_line(&diffstat, options);
4364                free_diffstat_info(&diffstat);
4365                separator++;
4366        }
4367        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4368                show_dirstat(options);
4369
4370        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4371                for (i = 0; i < q->nr; i++) {
4372                        diff_summary(options, q->queue[i]);
4373                }
4374                separator++;
4375        }
4376
4377        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4378            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4379            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4380                /*
4381                 * run diff_flush_patch for the exit status. setting
4382                 * options->file to /dev/null should be safe, becaue we
4383                 * aren't supposed to produce any output anyway.
4384                 */
4385                if (options->close_file)
4386                        fclose(options->file);
4387                options->file = fopen("/dev/null", "w");
4388                if (!options->file)
4389                        die_errno("Could not open /dev/null");
4390                options->close_file = 1;
4391                for (i = 0; i < q->nr; i++) {
4392                        struct diff_filepair *p = q->queue[i];
4393                        if (check_pair_status(p))
4394                                diff_flush_patch(p, options);
4395                        if (options->found_changes)
4396                                break;
4397                }
4398        }
4399
4400        if (output_format & DIFF_FORMAT_PATCH) {
4401                if (separator) {
4402                        putc(options->line_termination, options->file);
4403                        if (options->stat_sep) {
4404                                /* attach patch instead of inline */
4405                                fputs(options->stat_sep, options->file);
4406                        }
4407                }
4408
4409                for (i = 0; i < q->nr; i++) {
4410                        struct diff_filepair *p = q->queue[i];
4411                        if (check_pair_status(p))
4412                                diff_flush_patch(p, options);
4413                }
4414        }
4415
4416        if (output_format & DIFF_FORMAT_CALLBACK)
4417                options->format_callback(q, options, options->format_callback_data);
4418
4419        for (i = 0; i < q->nr; i++)
4420                diff_free_filepair(q->queue[i]);
4421free_queue:
4422        free(q->queue);
4423        DIFF_QUEUE_CLEAR(q);
4424        if (options->close_file)
4425                fclose(options->file);
4426
4427        /*
4428         * Report the content-level differences with HAS_CHANGES;
4429         * diff_addremove/diff_change does not set the bit when
4430         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4431         */
4432        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4433                if (options->found_changes)
4434                        DIFF_OPT_SET(options, HAS_CHANGES);
4435                else
4436                        DIFF_OPT_CLR(options, HAS_CHANGES);
4437        }
4438}
4439
4440static void diffcore_apply_filter(const char *filter)
4441{
4442        int i;
4443        struct diff_queue_struct *q = &diff_queued_diff;
4444        struct diff_queue_struct outq;
4445        DIFF_QUEUE_CLEAR(&outq);
4446
4447        if (!filter)
4448                return;
4449
4450        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4451                int found;
4452                for (i = found = 0; !found && i < q->nr; i++) {
4453                        struct diff_filepair *p = q->queue[i];
4454                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4455                             ((p->score &&
4456                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4457                              (!p->score &&
4458                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4459                            ((p->status != DIFF_STATUS_MODIFIED) &&
4460                             strchr(filter, p->status)))
4461                                found++;
4462                }
4463                if (found)
4464                        return;
4465
4466                /* otherwise we will clear the whole queue
4467                 * by copying the empty outq at the end of this
4468                 * function, but first clear the current entries
4469                 * in the queue.
4470                 */
4471                for (i = 0; i < q->nr; i++)
4472                        diff_free_filepair(q->queue[i]);
4473        }
4474        else {
4475                /* Only the matching ones */
4476                for (i = 0; i < q->nr; i++) {
4477                        struct diff_filepair *p = q->queue[i];
4478
4479                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4480                             ((p->score &&
4481                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4482                              (!p->score &&
4483                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4484                            ((p->status != DIFF_STATUS_MODIFIED) &&
4485                             strchr(filter, p->status)))
4486                                diff_q(&outq, p);
4487                        else
4488                                diff_free_filepair(p);
4489                }
4490        }
4491        free(q->queue);
4492        *q = outq;
4493}
4494
4495/* Check whether two filespecs with the same mode and size are identical */
4496static int diff_filespec_is_identical(struct diff_filespec *one,
4497                                      struct diff_filespec *two)
4498{
4499        if (S_ISGITLINK(one->mode))
4500                return 0;
4501        if (diff_populate_filespec(one, 0))
4502                return 0;
4503        if (diff_populate_filespec(two, 0))
4504                return 0;
4505        return !memcmp(one->data, two->data, one->size);
4506}
4507
4508static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4509{
4510        int i;
4511        struct diff_queue_struct *q = &diff_queued_diff;
4512        struct diff_queue_struct outq;
4513        DIFF_QUEUE_CLEAR(&outq);
4514
4515        for (i = 0; i < q->nr; i++) {
4516                struct diff_filepair *p = q->queue[i];
4517
4518                /*
4519                 * 1. Entries that come from stat info dirtiness
4520                 *    always have both sides (iow, not create/delete),
4521                 *    one side of the object name is unknown, with
4522                 *    the same mode and size.  Keep the ones that
4523                 *    do not match these criteria.  They have real
4524                 *    differences.
4525                 *
4526                 * 2. At this point, the file is known to be modified,
4527                 *    with the same mode and size, and the object
4528                 *    name of one side is unknown.  Need to inspect
4529                 *    the identical contents.
4530                 */
4531                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4532                    !DIFF_FILE_VALID(p->two) ||
4533                    (p->one->sha1_valid && p->two->sha1_valid) ||
4534                    (p->one->mode != p->two->mode) ||
4535                    diff_populate_filespec(p->one, 1) ||
4536                    diff_populate_filespec(p->two, 1) ||
4537                    (p->one->size != p->two->size) ||
4538                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4539                        diff_q(&outq, p);
4540                else {
4541                        /*
4542                         * The caller can subtract 1 from skip_stat_unmatch
4543                         * to determine how many paths were dirty only
4544                         * due to stat info mismatch.
4545                         */
4546                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4547                                diffopt->skip_stat_unmatch++;
4548                        diff_free_filepair(p);
4549                }
4550        }
4551        free(q->queue);
4552        *q = outq;
4553}
4554
4555static int diffnamecmp(const void *a_, const void *b_)
4556{
4557        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4558        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4559        const char *name_a, *name_b;
4560
4561        name_a = a->one ? a->one->path : a->two->path;
4562        name_b = b->one ? b->one->path : b->two->path;
4563        return strcmp(name_a, name_b);
4564}
4565
4566void diffcore_fix_diff_index(struct diff_options *options)
4567{
4568        struct diff_queue_struct *q = &diff_queued_diff;
4569        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4570}
4571
4572void diffcore_std(struct diff_options *options)
4573{
4574        if (options->skip_stat_unmatch)
4575                diffcore_skip_stat_unmatch(options);
4576        if (!options->found_follow) {
4577                /* See try_to_follow_renames() in tree-diff.c */
4578                if (options->break_opt != -1)
4579                        diffcore_break(options->break_opt);
4580                if (options->detect_rename)
4581                        diffcore_rename(options);
4582                if (options->break_opt != -1)
4583                        diffcore_merge_broken();
4584        }
4585        if (options->pickaxe)
4586                diffcore_pickaxe(options);
4587        if (options->orderfile)
4588                diffcore_order(options->orderfile);
4589        if (!options->found_follow)
4590                /* See try_to_follow_renames() in tree-diff.c */
4591                diff_resolve_rename_copy();
4592        diffcore_apply_filter(options->filter);
4593
4594        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4595                DIFF_OPT_SET(options, HAS_CHANGES);
4596        else
4597                DIFF_OPT_CLR(options, HAS_CHANGES);
4598
4599        options->found_follow = 0;
4600}
4601
4602int diff_result_code(struct diff_options *opt, int status)
4603{
4604        int result = 0;
4605
4606        diff_warn_rename_limit("diff.renamelimit",
4607                               opt->needed_rename_limit,
4608                               opt->degraded_cc_to_c);
4609        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4610            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4611                return status;
4612        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4613            DIFF_OPT_TST(opt, HAS_CHANGES))
4614                result |= 01;
4615        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4616            DIFF_OPT_TST(opt, CHECK_FAILED))
4617                result |= 02;
4618        return result;
4619}
4620
4621int diff_can_quit_early(struct diff_options *opt)
4622{
4623        return (DIFF_OPT_TST(opt, QUICK) &&
4624                !opt->filter &&
4625                DIFF_OPT_TST(opt, HAS_CHANGES));
4626}
4627
4628/*
4629 * Shall changes to this submodule be ignored?
4630 *
4631 * Submodule changes can be configured to be ignored separately for each path,
4632 * but that configuration can be overridden from the command line.
4633 */
4634static int is_submodule_ignored(const char *path, struct diff_options *options)
4635{
4636        int ignored = 0;
4637        unsigned orig_flags = options->flags;
4638        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4639                set_diffopt_flags_from_submodule_config(options, path);
4640        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4641                ignored = 1;
4642        options->flags = orig_flags;
4643        return ignored;
4644}
4645
4646void diff_addremove(struct diff_options *options,
4647                    int addremove, unsigned mode,
4648                    const unsigned char *sha1,
4649                    const char *concatpath, unsigned dirty_submodule)
4650{
4651        struct diff_filespec *one, *two;
4652
4653        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4654                return;
4655
4656        /* This may look odd, but it is a preparation for
4657         * feeding "there are unchanged files which should
4658         * not produce diffs, but when you are doing copy
4659         * detection you would need them, so here they are"
4660         * entries to the diff-core.  They will be prefixed
4661         * with something like '=' or '*' (I haven't decided
4662         * which but should not make any difference).
4663         * Feeding the same new and old to diff_change()
4664         * also has the same effect.
4665         * Before the final output happens, they are pruned after
4666         * merged into rename/copy pairs as appropriate.
4667         */
4668        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4669                addremove = (addremove == '+' ? '-' :
4670                             addremove == '-' ? '+' : addremove);
4671
4672        if (options->prefix &&
4673            strncmp(concatpath, options->prefix, options->prefix_length))
4674                return;
4675
4676        one = alloc_filespec(concatpath);
4677        two = alloc_filespec(concatpath);
4678
4679        if (addremove != '+')
4680                fill_filespec(one, sha1, mode);
4681        if (addremove != '-') {
4682                fill_filespec(two, sha1, mode);
4683                two->dirty_submodule = dirty_submodule;
4684        }
4685
4686        diff_queue(&diff_queued_diff, one, two);
4687        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4688                DIFF_OPT_SET(options, HAS_CHANGES);
4689}
4690
4691void diff_change(struct diff_options *options,
4692                 unsigned old_mode, unsigned new_mode,
4693                 const unsigned char *old_sha1,
4694                 const unsigned char *new_sha1,
4695                 const char *concatpath,
4696                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4697{
4698        struct diff_filespec *one, *two;
4699
4700        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4701            is_submodule_ignored(concatpath, options))
4702                return;
4703
4704        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4705                unsigned tmp;
4706                const unsigned char *tmp_c;
4707                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4708                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4709                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4710                        new_dirty_submodule = tmp;
4711        }
4712
4713        if (options->prefix &&
4714            strncmp(concatpath, options->prefix, options->prefix_length))
4715                return;
4716
4717        one = alloc_filespec(concatpath);
4718        two = alloc_filespec(concatpath);
4719        fill_filespec(one, old_sha1, old_mode);
4720        fill_filespec(two, new_sha1, new_mode);
4721        one->dirty_submodule = old_dirty_submodule;
4722        two->dirty_submodule = new_dirty_submodule;
4723
4724        diff_queue(&diff_queued_diff, one, two);
4725        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4726                DIFF_OPT_SET(options, HAS_CHANGES);
4727}
4728
4729struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4730{
4731        struct diff_filepair *pair;
4732        struct diff_filespec *one, *two;
4733
4734        if (options->prefix &&
4735            strncmp(path, options->prefix, options->prefix_length))
4736                return NULL;
4737
4738        one = alloc_filespec(path);
4739        two = alloc_filespec(path);
4740        pair = diff_queue(&diff_queued_diff, one, two);
4741        pair->is_unmerged = 1;
4742        return pair;
4743}
4744
4745static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4746                size_t *outsize)
4747{
4748        struct diff_tempfile *temp;
4749        const char *argv[3];
4750        const char **arg = argv;
4751        struct child_process child;
4752        struct strbuf buf = STRBUF_INIT;
4753        int err = 0;
4754
4755        temp = prepare_temp_file(spec->path, spec);
4756        *arg++ = pgm;
4757        *arg++ = temp->name;
4758        *arg = NULL;
4759
4760        memset(&child, 0, sizeof(child));
4761        child.use_shell = 1;
4762        child.argv = argv;
4763        child.out = -1;
4764        if (start_command(&child)) {
4765                remove_tempfile();
4766                return NULL;
4767        }
4768
4769        if (strbuf_read(&buf, child.out, 0) < 0)
4770                err = error("error reading from textconv command '%s'", pgm);
4771        close(child.out);
4772
4773        if (finish_command(&child) || err) {
4774                strbuf_release(&buf);
4775                remove_tempfile();
4776                return NULL;
4777        }
4778        remove_tempfile();
4779
4780        return strbuf_detach(&buf, outsize);
4781}
4782
4783size_t fill_textconv(struct userdiff_driver *driver,
4784                     struct diff_filespec *df,
4785                     char **outbuf)
4786{
4787        size_t size;
4788
4789        if (!driver || !driver->textconv) {
4790                if (!DIFF_FILE_VALID(df)) {
4791                        *outbuf = "";
4792                        return 0;
4793                }
4794                if (diff_populate_filespec(df, 0))
4795                        die("unable to read files to diff");
4796                *outbuf = df->data;
4797                return df->size;
4798        }
4799
4800        if (driver->textconv_cache && df->sha1_valid) {
4801                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4802                                          &size);
4803                if (*outbuf)
4804                        return size;
4805        }
4806
4807        *outbuf = run_textconv(driver->textconv, df, &size);
4808        if (!*outbuf)
4809                die("unable to read files to diff");
4810
4811        if (driver->textconv_cache && df->sha1_valid) {
4812                /* ignore errors, as we might be in a readonly repository */
4813                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4814                                size);
4815                /*
4816                 * we could save up changes and flush them all at the end,
4817                 * but we would need an extra call after all diffing is done.
4818                 * Since generating a cache entry is the slow path anyway,
4819                 * this extra overhead probably isn't a big deal.
4820                 */
4821                notes_cache_write(driver->textconv_cache);
4822        }
4823
4824        return size;
4825}