diff.con commit Merge branch 'jc/rerere-train' (7b871c5)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "delta.h"
   9#include "xdiff-interface.h"
  10#include "color.h"
  11#include "attr.h"
  12#include "run-command.h"
  13#include "utf8.h"
  14#include "userdiff.h"
  15#include "sigchain.h"
  16#include "submodule.h"
  17#include "ll-merge.h"
  18
  19#ifdef NO_FAST_WORKING_DIRECTORY
  20#define FAST_WORKING_DIRECTORY 0
  21#else
  22#define FAST_WORKING_DIRECTORY 1
  23#endif
  24
  25static int diff_detect_rename_default;
  26static int diff_rename_limit_default = 400;
  27static int diff_suppress_blank_empty;
  28int diff_use_color_default = -1;
  29static const char *diff_word_regex_cfg;
  30static const char *external_diff_cmd_cfg;
  31int diff_auto_refresh_index = 1;
  32static int diff_mnemonic_prefix;
  33static int diff_no_prefix;
  34static int diff_stat_graph_width;
  35static int diff_dirstat_permille_default = 30;
  36static struct diff_options default_diff_options;
  37
  38static char diff_colors[][COLOR_MAXLEN] = {
  39        GIT_COLOR_RESET,
  40        GIT_COLOR_NORMAL,       /* PLAIN */
  41        GIT_COLOR_BOLD,         /* METAINFO */
  42        GIT_COLOR_CYAN,         /* FRAGINFO */
  43        GIT_COLOR_RED,          /* OLD */
  44        GIT_COLOR_GREEN,        /* NEW */
  45        GIT_COLOR_YELLOW,       /* COMMIT */
  46        GIT_COLOR_BG_RED,       /* WHITESPACE */
  47        GIT_COLOR_NORMAL,       /* FUNCINFO */
  48};
  49
  50static int parse_diff_color_slot(const char *var, int ofs)
  51{
  52        if (!strcasecmp(var+ofs, "plain"))
  53                return DIFF_PLAIN;
  54        if (!strcasecmp(var+ofs, "meta"))
  55                return DIFF_METAINFO;
  56        if (!strcasecmp(var+ofs, "frag"))
  57                return DIFF_FRAGINFO;
  58        if (!strcasecmp(var+ofs, "old"))
  59                return DIFF_FILE_OLD;
  60        if (!strcasecmp(var+ofs, "new"))
  61                return DIFF_FILE_NEW;
  62        if (!strcasecmp(var+ofs, "commit"))
  63                return DIFF_COMMIT;
  64        if (!strcasecmp(var+ofs, "whitespace"))
  65                return DIFF_WHITESPACE;
  66        if (!strcasecmp(var+ofs, "func"))
  67                return DIFF_FUNCINFO;
  68        return -1;
  69}
  70
  71static int parse_dirstat_params(struct diff_options *options, const char *params,
  72                                struct strbuf *errmsg)
  73{
  74        const char *p = params;
  75        int p_len, ret = 0;
  76
  77        while (*p) {
  78                p_len = strchrnul(p, ',') - p;
  79                if (!memcmp(p, "changes", p_len)) {
  80                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  81                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  82                } else if (!memcmp(p, "lines", p_len)) {
  83                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
  84                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  85                } else if (!memcmp(p, "files", p_len)) {
  86                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  87                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
  88                } else if (!memcmp(p, "noncumulative", p_len)) {
  89                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
  90                } else if (!memcmp(p, "cumulative", p_len)) {
  91                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
  92                } else if (isdigit(*p)) {
  93                        char *end;
  94                        int permille = strtoul(p, &end, 10) * 10;
  95                        if (*end == '.' && isdigit(*++end)) {
  96                                /* only use first digit */
  97                                permille += *end - '0';
  98                                /* .. and ignore any further digits */
  99                                while (isdigit(*++end))
 100                                        ; /* nothing */
 101                        }
 102                        if (end - p == p_len)
 103                                options->dirstat_permille = permille;
 104                        else {
 105                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%.*s'\n"),
 106                                            p_len, p);
 107                                ret++;
 108                        }
 109                } else {
 110                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%.*s'\n"),
 111                                    p_len, p);
 112                        ret++;
 113                }
 114
 115                p += p_len;
 116
 117                if (*p)
 118                        p++; /* more parameters, swallow separator */
 119        }
 120        return ret;
 121}
 122
 123static int git_config_rename(const char *var, const char *value)
 124{
 125        if (!value)
 126                return DIFF_DETECT_RENAME;
 127        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 128                return  DIFF_DETECT_COPY;
 129        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 130}
 131
 132/*
 133 * These are to give UI layer defaults.
 134 * The core-level commands such as git-diff-files should
 135 * never be affected by the setting of diff.renames
 136 * the user happens to have in the configuration file.
 137 */
 138int git_diff_ui_config(const char *var, const char *value, void *cb)
 139{
 140        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 141                diff_use_color_default = git_config_colorbool(var, value);
 142                return 0;
 143        }
 144        if (!strcmp(var, "diff.renames")) {
 145                diff_detect_rename_default = git_config_rename(var, value);
 146                return 0;
 147        }
 148        if (!strcmp(var, "diff.autorefreshindex")) {
 149                diff_auto_refresh_index = git_config_bool(var, value);
 150                return 0;
 151        }
 152        if (!strcmp(var, "diff.mnemonicprefix")) {
 153                diff_mnemonic_prefix = git_config_bool(var, value);
 154                return 0;
 155        }
 156        if (!strcmp(var, "diff.noprefix")) {
 157                diff_no_prefix = git_config_bool(var, value);
 158                return 0;
 159        }
 160        if (!strcmp(var, "diff.statgraphwidth")) {
 161                diff_stat_graph_width = git_config_int(var, value);
 162                return 0;
 163        }
 164        if (!strcmp(var, "diff.external"))
 165                return git_config_string(&external_diff_cmd_cfg, var, value);
 166        if (!strcmp(var, "diff.wordregex"))
 167                return git_config_string(&diff_word_regex_cfg, var, value);
 168
 169        if (!strcmp(var, "diff.ignoresubmodules"))
 170                handle_ignore_submodules_arg(&default_diff_options, value);
 171
 172        if (git_color_config(var, value, cb) < 0)
 173                return -1;
 174
 175        return git_diff_basic_config(var, value, cb);
 176}
 177
 178int git_diff_basic_config(const char *var, const char *value, void *cb)
 179{
 180        if (!strcmp(var, "diff.renamelimit")) {
 181                diff_rename_limit_default = git_config_int(var, value);
 182                return 0;
 183        }
 184
 185        if (userdiff_config(var, value) < 0)
 186                return -1;
 187
 188        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 189                int slot = parse_diff_color_slot(var, 11);
 190                if (slot < 0)
 191                        return 0;
 192                if (!value)
 193                        return config_error_nonbool(var);
 194                color_parse(value, var, diff_colors[slot]);
 195                return 0;
 196        }
 197
 198        /* like GNU diff's --suppress-blank-empty option  */
 199        if (!strcmp(var, "diff.suppressblankempty") ||
 200                        /* for backwards compatibility */
 201                        !strcmp(var, "diff.suppress-blank-empty")) {
 202                diff_suppress_blank_empty = git_config_bool(var, value);
 203                return 0;
 204        }
 205
 206        if (!strcmp(var, "diff.dirstat")) {
 207                struct strbuf errmsg = STRBUF_INIT;
 208                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 209                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 210                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 211                                errmsg.buf);
 212                strbuf_release(&errmsg);
 213                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 214                return 0;
 215        }
 216
 217        if (!prefixcmp(var, "submodule."))
 218                return parse_submodule_config_option(var, value);
 219
 220        return git_default_config(var, value, cb);
 221}
 222
 223static char *quote_two(const char *one, const char *two)
 224{
 225        int need_one = quote_c_style(one, NULL, NULL, 1);
 226        int need_two = quote_c_style(two, NULL, NULL, 1);
 227        struct strbuf res = STRBUF_INIT;
 228
 229        if (need_one + need_two) {
 230                strbuf_addch(&res, '"');
 231                quote_c_style(one, &res, NULL, 1);
 232                quote_c_style(two, &res, NULL, 1);
 233                strbuf_addch(&res, '"');
 234        } else {
 235                strbuf_addstr(&res, one);
 236                strbuf_addstr(&res, two);
 237        }
 238        return strbuf_detach(&res, NULL);
 239}
 240
 241static const char *external_diff(void)
 242{
 243        static const char *external_diff_cmd = NULL;
 244        static int done_preparing = 0;
 245
 246        if (done_preparing)
 247                return external_diff_cmd;
 248        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 249        if (!external_diff_cmd)
 250                external_diff_cmd = external_diff_cmd_cfg;
 251        done_preparing = 1;
 252        return external_diff_cmd;
 253}
 254
 255static struct diff_tempfile {
 256        const char *name; /* filename external diff should read from */
 257        char hex[41];
 258        char mode[10];
 259        char tmp_path[PATH_MAX];
 260} diff_temp[2];
 261
 262typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 263
 264struct emit_callback {
 265        int color_diff;
 266        unsigned ws_rule;
 267        int blank_at_eof_in_preimage;
 268        int blank_at_eof_in_postimage;
 269        int lno_in_preimage;
 270        int lno_in_postimage;
 271        sane_truncate_fn truncate;
 272        const char **label_path;
 273        struct diff_words_data *diff_words;
 274        struct diff_options *opt;
 275        int *found_changesp;
 276        struct strbuf *header;
 277};
 278
 279static int count_lines(const char *data, int size)
 280{
 281        int count, ch, completely_empty = 1, nl_just_seen = 0;
 282        count = 0;
 283        while (0 < size--) {
 284                ch = *data++;
 285                if (ch == '\n') {
 286                        count++;
 287                        nl_just_seen = 1;
 288                        completely_empty = 0;
 289                }
 290                else {
 291                        nl_just_seen = 0;
 292                        completely_empty = 0;
 293                }
 294        }
 295        if (completely_empty)
 296                return 0;
 297        if (!nl_just_seen)
 298                count++; /* no trailing newline */
 299        return count;
 300}
 301
 302static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 303{
 304        if (!DIFF_FILE_VALID(one)) {
 305                mf->ptr = (char *)""; /* does not matter */
 306                mf->size = 0;
 307                return 0;
 308        }
 309        else if (diff_populate_filespec(one, 0))
 310                return -1;
 311
 312        mf->ptr = one->data;
 313        mf->size = one->size;
 314        return 0;
 315}
 316
 317/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 318static unsigned long diff_filespec_size(struct diff_filespec *one)
 319{
 320        if (!DIFF_FILE_VALID(one))
 321                return 0;
 322        diff_populate_filespec(one, 1);
 323        return one->size;
 324}
 325
 326static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 327{
 328        char *ptr = mf->ptr;
 329        long size = mf->size;
 330        int cnt = 0;
 331
 332        if (!size)
 333                return cnt;
 334        ptr += size - 1; /* pointing at the very end */
 335        if (*ptr != '\n')
 336                ; /* incomplete line */
 337        else
 338                ptr--; /* skip the last LF */
 339        while (mf->ptr < ptr) {
 340                char *prev_eol;
 341                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 342                        if (*prev_eol == '\n')
 343                                break;
 344                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 345                        break;
 346                cnt++;
 347                ptr = prev_eol - 1;
 348        }
 349        return cnt;
 350}
 351
 352static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 353                               struct emit_callback *ecbdata)
 354{
 355        int l1, l2, at;
 356        unsigned ws_rule = ecbdata->ws_rule;
 357        l1 = count_trailing_blank(mf1, ws_rule);
 358        l2 = count_trailing_blank(mf2, ws_rule);
 359        if (l2 <= l1) {
 360                ecbdata->blank_at_eof_in_preimage = 0;
 361                ecbdata->blank_at_eof_in_postimage = 0;
 362                return;
 363        }
 364        at = count_lines(mf1->ptr, mf1->size);
 365        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 366
 367        at = count_lines(mf2->ptr, mf2->size);
 368        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 369}
 370
 371static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 372                        int first, const char *line, int len)
 373{
 374        int has_trailing_newline, has_trailing_carriage_return;
 375        int nofirst;
 376        FILE *file = o->file;
 377
 378        if (o->output_prefix) {
 379                struct strbuf *msg = NULL;
 380                msg = o->output_prefix(o, o->output_prefix_data);
 381                assert(msg);
 382                fwrite(msg->buf, msg->len, 1, file);
 383        }
 384
 385        if (len == 0) {
 386                has_trailing_newline = (first == '\n');
 387                has_trailing_carriage_return = (!has_trailing_newline &&
 388                                                (first == '\r'));
 389                nofirst = has_trailing_newline || has_trailing_carriage_return;
 390        } else {
 391                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 392                if (has_trailing_newline)
 393                        len--;
 394                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 395                if (has_trailing_carriage_return)
 396                        len--;
 397                nofirst = 0;
 398        }
 399
 400        if (len || !nofirst) {
 401                fputs(set, file);
 402                if (!nofirst)
 403                        fputc(first, file);
 404                fwrite(line, len, 1, file);
 405                fputs(reset, file);
 406        }
 407        if (has_trailing_carriage_return)
 408                fputc('\r', file);
 409        if (has_trailing_newline)
 410                fputc('\n', file);
 411}
 412
 413static void emit_line(struct diff_options *o, const char *set, const char *reset,
 414                      const char *line, int len)
 415{
 416        emit_line_0(o, set, reset, line[0], line+1, len-1);
 417}
 418
 419static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 420{
 421        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 422              ecbdata->blank_at_eof_in_preimage &&
 423              ecbdata->blank_at_eof_in_postimage &&
 424              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 425              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 426                return 0;
 427        return ws_blank_line(line, len, ecbdata->ws_rule);
 428}
 429
 430static void emit_add_line(const char *reset,
 431                          struct emit_callback *ecbdata,
 432                          const char *line, int len)
 433{
 434        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 435        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 436
 437        if (!*ws)
 438                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 439        else if (new_blank_line_at_eof(ecbdata, line, len))
 440                /* Blank line at EOF - paint '+' as well */
 441                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 442        else {
 443                /* Emit just the prefix, then the rest. */
 444                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 445                ws_check_emit(line, len, ecbdata->ws_rule,
 446                              ecbdata->opt->file, set, reset, ws);
 447        }
 448}
 449
 450static void emit_hunk_header(struct emit_callback *ecbdata,
 451                             const char *line, int len)
 452{
 453        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 454        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 455        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 456        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 457        static const char atat[2] = { '@', '@' };
 458        const char *cp, *ep;
 459        struct strbuf msgbuf = STRBUF_INIT;
 460        int org_len = len;
 461        int i = 1;
 462
 463        /*
 464         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 465         * it always is at least 10 bytes long.
 466         */
 467        if (len < 10 ||
 468            memcmp(line, atat, 2) ||
 469            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 470                emit_line(ecbdata->opt, plain, reset, line, len);
 471                return;
 472        }
 473        ep += 2; /* skip over @@ */
 474
 475        /* The hunk header in fraginfo color */
 476        strbuf_add(&msgbuf, frag, strlen(frag));
 477        strbuf_add(&msgbuf, line, ep - line);
 478        strbuf_add(&msgbuf, reset, strlen(reset));
 479
 480        /*
 481         * trailing "\r\n"
 482         */
 483        for ( ; i < 3; i++)
 484                if (line[len - i] == '\r' || line[len - i] == '\n')
 485                        len--;
 486
 487        /* blank before the func header */
 488        for (cp = ep; ep - line < len; ep++)
 489                if (*ep != ' ' && *ep != '\t')
 490                        break;
 491        if (ep != cp) {
 492                strbuf_add(&msgbuf, plain, strlen(plain));
 493                strbuf_add(&msgbuf, cp, ep - cp);
 494                strbuf_add(&msgbuf, reset, strlen(reset));
 495        }
 496
 497        if (ep < line + len) {
 498                strbuf_add(&msgbuf, func, strlen(func));
 499                strbuf_add(&msgbuf, ep, line + len - ep);
 500                strbuf_add(&msgbuf, reset, strlen(reset));
 501        }
 502
 503        strbuf_add(&msgbuf, line + len, org_len - len);
 504        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 505        strbuf_release(&msgbuf);
 506}
 507
 508static struct diff_tempfile *claim_diff_tempfile(void) {
 509        int i;
 510        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 511                if (!diff_temp[i].name)
 512                        return diff_temp + i;
 513        die("BUG: diff is failing to clean up its tempfiles");
 514}
 515
 516static int remove_tempfile_installed;
 517
 518static void remove_tempfile(void)
 519{
 520        int i;
 521        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 522                if (diff_temp[i].name == diff_temp[i].tmp_path)
 523                        unlink_or_warn(diff_temp[i].name);
 524                diff_temp[i].name = NULL;
 525        }
 526}
 527
 528static void remove_tempfile_on_signal(int signo)
 529{
 530        remove_tempfile();
 531        sigchain_pop(signo);
 532        raise(signo);
 533}
 534
 535static void print_line_count(FILE *file, int count)
 536{
 537        switch (count) {
 538        case 0:
 539                fprintf(file, "0,0");
 540                break;
 541        case 1:
 542                fprintf(file, "1");
 543                break;
 544        default:
 545                fprintf(file, "1,%d", count);
 546                break;
 547        }
 548}
 549
 550static void emit_rewrite_lines(struct emit_callback *ecb,
 551                               int prefix, const char *data, int size)
 552{
 553        const char *endp = NULL;
 554        static const char *nneof = " No newline at end of file\n";
 555        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 556        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 557
 558        while (0 < size) {
 559                int len;
 560
 561                endp = memchr(data, '\n', size);
 562                len = endp ? (endp - data + 1) : size;
 563                if (prefix != '+') {
 564                        ecb->lno_in_preimage++;
 565                        emit_line_0(ecb->opt, old, reset, '-',
 566                                    data, len);
 567                } else {
 568                        ecb->lno_in_postimage++;
 569                        emit_add_line(reset, ecb, data, len);
 570                }
 571                size -= len;
 572                data += len;
 573        }
 574        if (!endp) {
 575                const char *plain = diff_get_color(ecb->color_diff,
 576                                                   DIFF_PLAIN);
 577                emit_line_0(ecb->opt, plain, reset, '\\',
 578                            nneof, strlen(nneof));
 579        }
 580}
 581
 582static void emit_rewrite_diff(const char *name_a,
 583                              const char *name_b,
 584                              struct diff_filespec *one,
 585                              struct diff_filespec *two,
 586                              struct userdiff_driver *textconv_one,
 587                              struct userdiff_driver *textconv_two,
 588                              struct diff_options *o)
 589{
 590        int lc_a, lc_b;
 591        const char *name_a_tab, *name_b_tab;
 592        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 593        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 594        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 595        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 596        const char *a_prefix, *b_prefix;
 597        char *data_one, *data_two;
 598        size_t size_one, size_two;
 599        struct emit_callback ecbdata;
 600        char *line_prefix = "";
 601        struct strbuf *msgbuf;
 602
 603        if (o && o->output_prefix) {
 604                msgbuf = o->output_prefix(o, o->output_prefix_data);
 605                line_prefix = msgbuf->buf;
 606        }
 607
 608        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 609                a_prefix = o->b_prefix;
 610                b_prefix = o->a_prefix;
 611        } else {
 612                a_prefix = o->a_prefix;
 613                b_prefix = o->b_prefix;
 614        }
 615
 616        name_a += (*name_a == '/');
 617        name_b += (*name_b == '/');
 618        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 619        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 620
 621        strbuf_reset(&a_name);
 622        strbuf_reset(&b_name);
 623        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 624        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 625
 626        size_one = fill_textconv(textconv_one, one, &data_one);
 627        size_two = fill_textconv(textconv_two, two, &data_two);
 628
 629        memset(&ecbdata, 0, sizeof(ecbdata));
 630        ecbdata.color_diff = want_color(o->use_color);
 631        ecbdata.found_changesp = &o->found_changes;
 632        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 633        ecbdata.opt = o;
 634        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 635                mmfile_t mf1, mf2;
 636                mf1.ptr = (char *)data_one;
 637                mf2.ptr = (char *)data_two;
 638                mf1.size = size_one;
 639                mf2.size = size_two;
 640                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 641        }
 642        ecbdata.lno_in_preimage = 1;
 643        ecbdata.lno_in_postimage = 1;
 644
 645        lc_a = count_lines(data_one, size_one);
 646        lc_b = count_lines(data_two, size_two);
 647        fprintf(o->file,
 648                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 649                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 650                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 651                line_prefix, fraginfo);
 652        if (!o->irreversible_delete)
 653                print_line_count(o->file, lc_a);
 654        else
 655                fprintf(o->file, "?,?");
 656        fprintf(o->file, " +");
 657        print_line_count(o->file, lc_b);
 658        fprintf(o->file, " @@%s\n", reset);
 659        if (lc_a && !o->irreversible_delete)
 660                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 661        if (lc_b)
 662                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 663        if (textconv_one)
 664                free((char *)data_one);
 665        if (textconv_two)
 666                free((char *)data_two);
 667}
 668
 669struct diff_words_buffer {
 670        mmfile_t text;
 671        long alloc;
 672        struct diff_words_orig {
 673                const char *begin, *end;
 674        } *orig;
 675        int orig_nr, orig_alloc;
 676};
 677
 678static void diff_words_append(char *line, unsigned long len,
 679                struct diff_words_buffer *buffer)
 680{
 681        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 682        line++;
 683        len--;
 684        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 685        buffer->text.size += len;
 686        buffer->text.ptr[buffer->text.size] = '\0';
 687}
 688
 689struct diff_words_style_elem {
 690        const char *prefix;
 691        const char *suffix;
 692        const char *color; /* NULL; filled in by the setup code if
 693                            * color is enabled */
 694};
 695
 696struct diff_words_style {
 697        enum diff_words_type type;
 698        struct diff_words_style_elem new, old, ctx;
 699        const char *newline;
 700};
 701
 702static struct diff_words_style diff_words_styles[] = {
 703        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 704        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 705        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 706};
 707
 708struct diff_words_data {
 709        struct diff_words_buffer minus, plus;
 710        const char *current_plus;
 711        int last_minus;
 712        struct diff_options *opt;
 713        regex_t *word_regex;
 714        enum diff_words_type type;
 715        struct diff_words_style *style;
 716};
 717
 718static int fn_out_diff_words_write_helper(FILE *fp,
 719                                          struct diff_words_style_elem *st_el,
 720                                          const char *newline,
 721                                          size_t count, const char *buf,
 722                                          const char *line_prefix)
 723{
 724        int print = 0;
 725
 726        while (count) {
 727                char *p = memchr(buf, '\n', count);
 728                if (print)
 729                        fputs(line_prefix, fp);
 730                if (p != buf) {
 731                        if (st_el->color && fputs(st_el->color, fp) < 0)
 732                                return -1;
 733                        if (fputs(st_el->prefix, fp) < 0 ||
 734                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 735                            fputs(st_el->suffix, fp) < 0)
 736                                return -1;
 737                        if (st_el->color && *st_el->color
 738                            && fputs(GIT_COLOR_RESET, fp) < 0)
 739                                return -1;
 740                }
 741                if (!p)
 742                        return 0;
 743                if (fputs(newline, fp) < 0)
 744                        return -1;
 745                count -= p + 1 - buf;
 746                buf = p + 1;
 747                print = 1;
 748        }
 749        return 0;
 750}
 751
 752/*
 753 * '--color-words' algorithm can be described as:
 754 *
 755 *   1. collect a the minus/plus lines of a diff hunk, divided into
 756 *      minus-lines and plus-lines;
 757 *
 758 *   2. break both minus-lines and plus-lines into words and
 759 *      place them into two mmfile_t with one word for each line;
 760 *
 761 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 762 *
 763 * And for the common parts of the both file, we output the plus side text.
 764 * diff_words->current_plus is used to trace the current position of the plus file
 765 * which printed. diff_words->last_minus is used to trace the last minus word
 766 * printed.
 767 *
 768 * For '--graph' to work with '--color-words', we need to output the graph prefix
 769 * on each line of color words output. Generally, there are two conditions on
 770 * which we should output the prefix.
 771 *
 772 *   1. diff_words->last_minus == 0 &&
 773 *      diff_words->current_plus == diff_words->plus.text.ptr
 774 *
 775 *      that is: the plus text must start as a new line, and if there is no minus
 776 *      word printed, a graph prefix must be printed.
 777 *
 778 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 779 *      *(diff_words->current_plus - 1) == '\n'
 780 *
 781 *      that is: a graph prefix must be printed following a '\n'
 782 */
 783static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 784{
 785        if ((diff_words->last_minus == 0 &&
 786                diff_words->current_plus == diff_words->plus.text.ptr) ||
 787                (diff_words->current_plus > diff_words->plus.text.ptr &&
 788                *(diff_words->current_plus - 1) == '\n')) {
 789                return 1;
 790        } else {
 791                return 0;
 792        }
 793}
 794
 795static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 796{
 797        struct diff_words_data *diff_words = priv;
 798        struct diff_words_style *style = diff_words->style;
 799        int minus_first, minus_len, plus_first, plus_len;
 800        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 801        struct diff_options *opt = diff_words->opt;
 802        struct strbuf *msgbuf;
 803        char *line_prefix = "";
 804
 805        if (line[0] != '@' || parse_hunk_header(line, len,
 806                        &minus_first, &minus_len, &plus_first, &plus_len))
 807                return;
 808
 809        assert(opt);
 810        if (opt->output_prefix) {
 811                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 812                line_prefix = msgbuf->buf;
 813        }
 814
 815        /* POSIX requires that first be decremented by one if len == 0... */
 816        if (minus_len) {
 817                minus_begin = diff_words->minus.orig[minus_first].begin;
 818                minus_end =
 819                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 820        } else
 821                minus_begin = minus_end =
 822                        diff_words->minus.orig[minus_first].end;
 823
 824        if (plus_len) {
 825                plus_begin = diff_words->plus.orig[plus_first].begin;
 826                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 827        } else
 828                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 829
 830        if (color_words_output_graph_prefix(diff_words)) {
 831                fputs(line_prefix, diff_words->opt->file);
 832        }
 833        if (diff_words->current_plus != plus_begin) {
 834                fn_out_diff_words_write_helper(diff_words->opt->file,
 835                                &style->ctx, style->newline,
 836                                plus_begin - diff_words->current_plus,
 837                                diff_words->current_plus, line_prefix);
 838                if (*(plus_begin - 1) == '\n')
 839                        fputs(line_prefix, diff_words->opt->file);
 840        }
 841        if (minus_begin != minus_end) {
 842                fn_out_diff_words_write_helper(diff_words->opt->file,
 843                                &style->old, style->newline,
 844                                minus_end - minus_begin, minus_begin,
 845                                line_prefix);
 846        }
 847        if (plus_begin != plus_end) {
 848                fn_out_diff_words_write_helper(diff_words->opt->file,
 849                                &style->new, style->newline,
 850                                plus_end - plus_begin, plus_begin,
 851                                line_prefix);
 852        }
 853
 854        diff_words->current_plus = plus_end;
 855        diff_words->last_minus = minus_first;
 856}
 857
 858/* This function starts looking at *begin, and returns 0 iff a word was found. */
 859static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 860                int *begin, int *end)
 861{
 862        if (word_regex && *begin < buffer->size) {
 863                regmatch_t match[1];
 864                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 865                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 866                                        '\n', match[0].rm_eo - match[0].rm_so);
 867                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 868                        *begin += match[0].rm_so;
 869                        return *begin >= *end;
 870                }
 871                return -1;
 872        }
 873
 874        /* find the next word */
 875        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 876                (*begin)++;
 877        if (*begin >= buffer->size)
 878                return -1;
 879
 880        /* find the end of the word */
 881        *end = *begin + 1;
 882        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 883                (*end)++;
 884
 885        return 0;
 886}
 887
 888/*
 889 * This function splits the words in buffer->text, stores the list with
 890 * newline separator into out, and saves the offsets of the original words
 891 * in buffer->orig.
 892 */
 893static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 894                regex_t *word_regex)
 895{
 896        int i, j;
 897        long alloc = 0;
 898
 899        out->size = 0;
 900        out->ptr = NULL;
 901
 902        /* fake an empty "0th" word */
 903        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 904        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 905        buffer->orig_nr = 1;
 906
 907        for (i = 0; i < buffer->text.size; i++) {
 908                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 909                        return;
 910
 911                /* store original boundaries */
 912                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 913                                buffer->orig_alloc);
 914                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 915                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 916                buffer->orig_nr++;
 917
 918                /* store one word */
 919                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 920                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 921                out->ptr[out->size + j - i] = '\n';
 922                out->size += j - i + 1;
 923
 924                i = j - 1;
 925        }
 926}
 927
 928/* this executes the word diff on the accumulated buffers */
 929static void diff_words_show(struct diff_words_data *diff_words)
 930{
 931        xpparam_t xpp;
 932        xdemitconf_t xecfg;
 933        mmfile_t minus, plus;
 934        struct diff_words_style *style = diff_words->style;
 935
 936        struct diff_options *opt = diff_words->opt;
 937        struct strbuf *msgbuf;
 938        char *line_prefix = "";
 939
 940        assert(opt);
 941        if (opt->output_prefix) {
 942                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 943                line_prefix = msgbuf->buf;
 944        }
 945
 946        /* special case: only removal */
 947        if (!diff_words->plus.text.size) {
 948                fputs(line_prefix, diff_words->opt->file);
 949                fn_out_diff_words_write_helper(diff_words->opt->file,
 950                        &style->old, style->newline,
 951                        diff_words->minus.text.size,
 952                        diff_words->minus.text.ptr, line_prefix);
 953                diff_words->minus.text.size = 0;
 954                return;
 955        }
 956
 957        diff_words->current_plus = diff_words->plus.text.ptr;
 958        diff_words->last_minus = 0;
 959
 960        memset(&xpp, 0, sizeof(xpp));
 961        memset(&xecfg, 0, sizeof(xecfg));
 962        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 963        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 964        xpp.flags = 0;
 965        /* as only the hunk header will be parsed, we need a 0-context */
 966        xecfg.ctxlen = 0;
 967        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 968                      &xpp, &xecfg);
 969        free(minus.ptr);
 970        free(plus.ptr);
 971        if (diff_words->current_plus != diff_words->plus.text.ptr +
 972                        diff_words->plus.text.size) {
 973                if (color_words_output_graph_prefix(diff_words))
 974                        fputs(line_prefix, diff_words->opt->file);
 975                fn_out_diff_words_write_helper(diff_words->opt->file,
 976                        &style->ctx, style->newline,
 977                        diff_words->plus.text.ptr + diff_words->plus.text.size
 978                        - diff_words->current_plus, diff_words->current_plus,
 979                        line_prefix);
 980        }
 981        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 982}
 983
 984/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 985static void diff_words_flush(struct emit_callback *ecbdata)
 986{
 987        if (ecbdata->diff_words->minus.text.size ||
 988            ecbdata->diff_words->plus.text.size)
 989                diff_words_show(ecbdata->diff_words);
 990}
 991
 992static void diff_filespec_load_driver(struct diff_filespec *one)
 993{
 994        /* Use already-loaded driver */
 995        if (one->driver)
 996                return;
 997
 998        if (S_ISREG(one->mode))
 999                one->driver = userdiff_find_by_path(one->path);
1000
1001        /* Fallback to default settings */
1002        if (!one->driver)
1003                one->driver = userdiff_find_by_name("default");
1004}
1005
1006static const char *userdiff_word_regex(struct diff_filespec *one)
1007{
1008        diff_filespec_load_driver(one);
1009        return one->driver->word_regex;
1010}
1011
1012static void init_diff_words_data(struct emit_callback *ecbdata,
1013                                 struct diff_options *orig_opts,
1014                                 struct diff_filespec *one,
1015                                 struct diff_filespec *two)
1016{
1017        int i;
1018        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1019        memcpy(o, orig_opts, sizeof(struct diff_options));
1020
1021        ecbdata->diff_words =
1022                xcalloc(1, sizeof(struct diff_words_data));
1023        ecbdata->diff_words->type = o->word_diff;
1024        ecbdata->diff_words->opt = o;
1025        if (!o->word_regex)
1026                o->word_regex = userdiff_word_regex(one);
1027        if (!o->word_regex)
1028                o->word_regex = userdiff_word_regex(two);
1029        if (!o->word_regex)
1030                o->word_regex = diff_word_regex_cfg;
1031        if (o->word_regex) {
1032                ecbdata->diff_words->word_regex = (regex_t *)
1033                        xmalloc(sizeof(regex_t));
1034                if (regcomp(ecbdata->diff_words->word_regex,
1035                            o->word_regex,
1036                            REG_EXTENDED | REG_NEWLINE))
1037                        die ("Invalid regular expression: %s",
1038                             o->word_regex);
1039        }
1040        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1041                if (o->word_diff == diff_words_styles[i].type) {
1042                        ecbdata->diff_words->style =
1043                                &diff_words_styles[i];
1044                        break;
1045                }
1046        }
1047        if (want_color(o->use_color)) {
1048                struct diff_words_style *st = ecbdata->diff_words->style;
1049                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1050                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1051                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
1052        }
1053}
1054
1055static void free_diff_words_data(struct emit_callback *ecbdata)
1056{
1057        if (ecbdata->diff_words) {
1058                diff_words_flush(ecbdata);
1059                free (ecbdata->diff_words->opt);
1060                free (ecbdata->diff_words->minus.text.ptr);
1061                free (ecbdata->diff_words->minus.orig);
1062                free (ecbdata->diff_words->plus.text.ptr);
1063                free (ecbdata->diff_words->plus.orig);
1064                if (ecbdata->diff_words->word_regex) {
1065                        regfree(ecbdata->diff_words->word_regex);
1066                        free(ecbdata->diff_words->word_regex);
1067                }
1068                free(ecbdata->diff_words);
1069                ecbdata->diff_words = NULL;
1070        }
1071}
1072
1073const char *diff_get_color(int diff_use_color, enum color_diff ix)
1074{
1075        if (want_color(diff_use_color))
1076                return diff_colors[ix];
1077        return "";
1078}
1079
1080static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1081{
1082        const char *cp;
1083        unsigned long allot;
1084        size_t l = len;
1085
1086        if (ecb->truncate)
1087                return ecb->truncate(line, len);
1088        cp = line;
1089        allot = l;
1090        while (0 < l) {
1091                (void) utf8_width(&cp, &l);
1092                if (!cp)
1093                        break; /* truncated in the middle? */
1094        }
1095        return allot - l;
1096}
1097
1098static void find_lno(const char *line, struct emit_callback *ecbdata)
1099{
1100        const char *p;
1101        ecbdata->lno_in_preimage = 0;
1102        ecbdata->lno_in_postimage = 0;
1103        p = strchr(line, '-');
1104        if (!p)
1105                return; /* cannot happen */
1106        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1107        p = strchr(p, '+');
1108        if (!p)
1109                return; /* cannot happen */
1110        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1111}
1112
1113static void fn_out_consume(void *priv, char *line, unsigned long len)
1114{
1115        struct emit_callback *ecbdata = priv;
1116        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1117        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1118        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1119        struct diff_options *o = ecbdata->opt;
1120        char *line_prefix = "";
1121        struct strbuf *msgbuf;
1122
1123        if (o && o->output_prefix) {
1124                msgbuf = o->output_prefix(o, o->output_prefix_data);
1125                line_prefix = msgbuf->buf;
1126        }
1127
1128        if (ecbdata->header) {
1129                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1130                strbuf_reset(ecbdata->header);
1131                ecbdata->header = NULL;
1132        }
1133        *(ecbdata->found_changesp) = 1;
1134
1135        if (ecbdata->label_path[0]) {
1136                const char *name_a_tab, *name_b_tab;
1137
1138                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1139                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1140
1141                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1142                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1143                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1144                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1145                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1146        }
1147
1148        if (diff_suppress_blank_empty
1149            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1150                line[0] = '\n';
1151                len = 1;
1152        }
1153
1154        if (line[0] == '@') {
1155                if (ecbdata->diff_words)
1156                        diff_words_flush(ecbdata);
1157                len = sane_truncate_line(ecbdata, line, len);
1158                find_lno(line, ecbdata);
1159                emit_hunk_header(ecbdata, line, len);
1160                if (line[len-1] != '\n')
1161                        putc('\n', ecbdata->opt->file);
1162                return;
1163        }
1164
1165        if (len < 1) {
1166                emit_line(ecbdata->opt, reset, reset, line, len);
1167                if (ecbdata->diff_words
1168                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1169                        fputs("~\n", ecbdata->opt->file);
1170                return;
1171        }
1172
1173        if (ecbdata->diff_words) {
1174                if (line[0] == '-') {
1175                        diff_words_append(line, len,
1176                                          &ecbdata->diff_words->minus);
1177                        return;
1178                } else if (line[0] == '+') {
1179                        diff_words_append(line, len,
1180                                          &ecbdata->diff_words->plus);
1181                        return;
1182                } else if (!prefixcmp(line, "\\ ")) {
1183                        /*
1184                         * Eat the "no newline at eof" marker as if we
1185                         * saw a "+" or "-" line with nothing on it,
1186                         * and return without diff_words_flush() to
1187                         * defer processing. If this is the end of
1188                         * preimage, more "+" lines may come after it.
1189                         */
1190                        return;
1191                }
1192                diff_words_flush(ecbdata);
1193                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1194                        emit_line(ecbdata->opt, plain, reset, line, len);
1195                        fputs("~\n", ecbdata->opt->file);
1196                } else {
1197                        /*
1198                         * Skip the prefix character, if any.  With
1199                         * diff_suppress_blank_empty, there may be
1200                         * none.
1201                         */
1202                        if (line[0] != '\n') {
1203                              line++;
1204                              len--;
1205                        }
1206                        emit_line(ecbdata->opt, plain, reset, line, len);
1207                }
1208                return;
1209        }
1210
1211        if (line[0] != '+') {
1212                const char *color =
1213                        diff_get_color(ecbdata->color_diff,
1214                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1215                ecbdata->lno_in_preimage++;
1216                if (line[0] == ' ')
1217                        ecbdata->lno_in_postimage++;
1218                emit_line(ecbdata->opt, color, reset, line, len);
1219        } else {
1220                ecbdata->lno_in_postimage++;
1221                emit_add_line(reset, ecbdata, line + 1, len - 1);
1222        }
1223}
1224
1225static char *pprint_rename(const char *a, const char *b)
1226{
1227        const char *old = a;
1228        const char *new = b;
1229        struct strbuf name = STRBUF_INIT;
1230        int pfx_length, sfx_length;
1231        int len_a = strlen(a);
1232        int len_b = strlen(b);
1233        int a_midlen, b_midlen;
1234        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1235        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1236
1237        if (qlen_a || qlen_b) {
1238                quote_c_style(a, &name, NULL, 0);
1239                strbuf_addstr(&name, " => ");
1240                quote_c_style(b, &name, NULL, 0);
1241                return strbuf_detach(&name, NULL);
1242        }
1243
1244        /* Find common prefix */
1245        pfx_length = 0;
1246        while (*old && *new && *old == *new) {
1247                if (*old == '/')
1248                        pfx_length = old - a + 1;
1249                old++;
1250                new++;
1251        }
1252
1253        /* Find common suffix */
1254        old = a + len_a;
1255        new = b + len_b;
1256        sfx_length = 0;
1257        while (a <= old && b <= new && *old == *new) {
1258                if (*old == '/')
1259                        sfx_length = len_a - (old - a);
1260                old--;
1261                new--;
1262        }
1263
1264        /*
1265         * pfx{mid-a => mid-b}sfx
1266         * {pfx-a => pfx-b}sfx
1267         * pfx{sfx-a => sfx-b}
1268         * name-a => name-b
1269         */
1270        a_midlen = len_a - pfx_length - sfx_length;
1271        b_midlen = len_b - pfx_length - sfx_length;
1272        if (a_midlen < 0)
1273                a_midlen = 0;
1274        if (b_midlen < 0)
1275                b_midlen = 0;
1276
1277        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1278        if (pfx_length + sfx_length) {
1279                strbuf_add(&name, a, pfx_length);
1280                strbuf_addch(&name, '{');
1281        }
1282        strbuf_add(&name, a + pfx_length, a_midlen);
1283        strbuf_addstr(&name, " => ");
1284        strbuf_add(&name, b + pfx_length, b_midlen);
1285        if (pfx_length + sfx_length) {
1286                strbuf_addch(&name, '}');
1287                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1288        }
1289        return strbuf_detach(&name, NULL);
1290}
1291
1292struct diffstat_t {
1293        int nr;
1294        int alloc;
1295        struct diffstat_file {
1296                char *from_name;
1297                char *name;
1298                char *print_name;
1299                unsigned is_unmerged:1;
1300                unsigned is_binary:1;
1301                unsigned is_renamed:1;
1302                uintmax_t added, deleted;
1303        } **files;
1304};
1305
1306static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1307                                          const char *name_a,
1308                                          const char *name_b)
1309{
1310        struct diffstat_file *x;
1311        x = xcalloc(sizeof (*x), 1);
1312        if (diffstat->nr == diffstat->alloc) {
1313                diffstat->alloc = alloc_nr(diffstat->alloc);
1314                diffstat->files = xrealloc(diffstat->files,
1315                                diffstat->alloc * sizeof(x));
1316        }
1317        diffstat->files[diffstat->nr++] = x;
1318        if (name_b) {
1319                x->from_name = xstrdup(name_a);
1320                x->name = xstrdup(name_b);
1321                x->is_renamed = 1;
1322        }
1323        else {
1324                x->from_name = NULL;
1325                x->name = xstrdup(name_a);
1326        }
1327        return x;
1328}
1329
1330static void diffstat_consume(void *priv, char *line, unsigned long len)
1331{
1332        struct diffstat_t *diffstat = priv;
1333        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1334
1335        if (line[0] == '+')
1336                x->added++;
1337        else if (line[0] == '-')
1338                x->deleted++;
1339}
1340
1341const char mime_boundary_leader[] = "------------";
1342
1343static int scale_linear(int it, int width, int max_change)
1344{
1345        if (!it)
1346                return 0;
1347        /*
1348         * make sure that at least one '-' or '+' is printed if
1349         * there is any change to this path. The easiest way is to
1350         * scale linearly as if the alloted width is one column shorter
1351         * than it is, and then add 1 to the result.
1352         */
1353        return 1 + (it * (width - 1) / max_change);
1354}
1355
1356static void show_name(FILE *file,
1357                      const char *prefix, const char *name, int len)
1358{
1359        fprintf(file, " %s%-*s |", prefix, len, name);
1360}
1361
1362static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1363{
1364        if (cnt <= 0)
1365                return;
1366        fprintf(file, "%s", set);
1367        while (cnt--)
1368                putc(ch, file);
1369        fprintf(file, "%s", reset);
1370}
1371
1372static void fill_print_name(struct diffstat_file *file)
1373{
1374        char *pname;
1375
1376        if (file->print_name)
1377                return;
1378
1379        if (!file->is_renamed) {
1380                struct strbuf buf = STRBUF_INIT;
1381                if (quote_c_style(file->name, &buf, NULL, 0)) {
1382                        pname = strbuf_detach(&buf, NULL);
1383                } else {
1384                        pname = file->name;
1385                        strbuf_release(&buf);
1386                }
1387        } else {
1388                pname = pprint_rename(file->from_name, file->name);
1389        }
1390        file->print_name = pname;
1391}
1392
1393int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1394{
1395        struct strbuf sb = STRBUF_INIT;
1396        int ret;
1397
1398        if (!files) {
1399                assert(insertions == 0 && deletions == 0);
1400                return fputs(_(" 0 files changed\n"), fp);
1401        }
1402
1403        strbuf_addf(&sb,
1404                    Q_(" %d file changed", " %d files changed", files),
1405                    files);
1406
1407        /*
1408         * For binary diff, the caller may want to print "x files
1409         * changed" with insertions == 0 && deletions == 0.
1410         *
1411         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1412         * is probably less confusing (i.e skip over "2 files changed
1413         * but nothing about added/removed lines? Is this a bug in Git?").
1414         */
1415        if (insertions || deletions == 0) {
1416                /*
1417                 * TRANSLATORS: "+" in (+) is a line addition marker;
1418                 * do not translate it.
1419                 */
1420                strbuf_addf(&sb,
1421                            Q_(", %d insertion(+)", ", %d insertions(+)",
1422                               insertions),
1423                            insertions);
1424        }
1425
1426        if (deletions || insertions == 0) {
1427                /*
1428                 * TRANSLATORS: "-" in (-) is a line removal marker;
1429                 * do not translate it.
1430                 */
1431                strbuf_addf(&sb,
1432                            Q_(", %d deletion(-)", ", %d deletions(-)",
1433                               deletions),
1434                            deletions);
1435        }
1436        strbuf_addch(&sb, '\n');
1437        ret = fputs(sb.buf, fp);
1438        strbuf_release(&sb);
1439        return ret;
1440}
1441
1442static void show_stats(struct diffstat_t *data, struct diff_options *options)
1443{
1444        int i, len, add, del, adds = 0, dels = 0;
1445        uintmax_t max_change = 0, max_len = 0;
1446        int total_files = data->nr;
1447        int width, name_width, graph_width, number_width = 4, count;
1448        const char *reset, *add_c, *del_c;
1449        const char *line_prefix = "";
1450        int extra_shown = 0;
1451        struct strbuf *msg = NULL;
1452
1453        if (data->nr == 0)
1454                return;
1455
1456        if (options->output_prefix) {
1457                msg = options->output_prefix(options, options->output_prefix_data);
1458                line_prefix = msg->buf;
1459        }
1460
1461        count = options->stat_count ? options->stat_count : data->nr;
1462
1463        reset = diff_get_color_opt(options, DIFF_RESET);
1464        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1465        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1466
1467        /*
1468         * Find the longest filename and max number of changes
1469         */
1470        for (i = 0; (i < count) && (i < data->nr); i++) {
1471                struct diffstat_file *file = data->files[i];
1472                uintmax_t change = file->added + file->deleted;
1473                if (!data->files[i]->is_renamed &&
1474                         (change == 0)) {
1475                        count++; /* not shown == room for one more */
1476                        continue;
1477                }
1478                fill_print_name(file);
1479                len = strlen(file->print_name);
1480                if (max_len < len)
1481                        max_len = len;
1482
1483                if (file->is_binary || file->is_unmerged)
1484                        continue;
1485                if (max_change < change)
1486                        max_change = change;
1487        }
1488        count = i; /* min(count, data->nr) */
1489
1490        /*
1491         * We have width = stat_width or term_columns() columns total.
1492         * We want a maximum of min(max_len, stat_name_width) for the name part.
1493         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1494         * We also need 1 for " " and 4 + decimal_width(max_change)
1495         * for " | NNNN " and one the empty column at the end, altogether
1496         * 6 + decimal_width(max_change).
1497         *
1498         * If there's not enough space, we will use the smaller of
1499         * stat_name_width (if set) and 5/8*width for the filename,
1500         * and the rest for constant elements + graph part, but no more
1501         * than stat_graph_width for the graph part.
1502         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1503         * for the standard terminal size).
1504         *
1505         * In other words: stat_width limits the maximum width, and
1506         * stat_name_width fixes the maximum width of the filename,
1507         * and is also used to divide available columns if there
1508         * aren't enough.
1509         */
1510
1511        if (options->stat_width == -1)
1512                width = term_columns() - options->output_prefix_length;
1513        else
1514                width = options->stat_width ? options->stat_width : 80;
1515
1516        if (options->stat_graph_width == -1)
1517                options->stat_graph_width = diff_stat_graph_width;
1518
1519        /*
1520         * Guarantee 3/8*16==6 for the graph part
1521         * and 5/8*16==10 for the filename part
1522         */
1523        if (width < 16 + 6 + number_width)
1524                width = 16 + 6 + number_width;
1525
1526        /*
1527         * First assign sizes that are wanted, ignoring available width.
1528         */
1529        graph_width = (options->stat_graph_width &&
1530                       options->stat_graph_width < max_change) ?
1531                options->stat_graph_width : max_change;
1532        name_width = (options->stat_name_width > 0 &&
1533                      options->stat_name_width < max_len) ?
1534                options->stat_name_width : max_len;
1535
1536        /*
1537         * Adjust adjustable widths not to exceed maximum width
1538         */
1539        if (name_width + number_width + 6 + graph_width > width) {
1540                if (graph_width > width * 3/8 - number_width - 6) {
1541                        graph_width = width * 3/8 - number_width - 6;
1542                        if (graph_width < 6)
1543                                graph_width = 6;
1544                }
1545
1546                if (options->stat_graph_width &&
1547                    graph_width > options->stat_graph_width)
1548                        graph_width = options->stat_graph_width;
1549                if (name_width > width - number_width - 6 - graph_width)
1550                        name_width = width - number_width - 6 - graph_width;
1551                else
1552                        graph_width = width - number_width - 6 - name_width;
1553        }
1554
1555        /*
1556         * From here name_width is the width of the name area,
1557         * and graph_width is the width of the graph area.
1558         * max_change is used to scale graph properly.
1559         */
1560        for (i = 0; i < count; i++) {
1561                const char *prefix = "";
1562                char *name = data->files[i]->print_name;
1563                uintmax_t added = data->files[i]->added;
1564                uintmax_t deleted = data->files[i]->deleted;
1565                int name_len;
1566
1567                if (!data->files[i]->is_renamed &&
1568                         (added + deleted == 0)) {
1569                        total_files--;
1570                        continue;
1571                }
1572                /*
1573                 * "scale" the filename
1574                 */
1575                len = name_width;
1576                name_len = strlen(name);
1577                if (name_width < name_len) {
1578                        char *slash;
1579                        prefix = "...";
1580                        len -= 3;
1581                        name += name_len - len;
1582                        slash = strchr(name, '/');
1583                        if (slash)
1584                                name = slash;
1585                }
1586
1587                if (data->files[i]->is_binary) {
1588                        fprintf(options->file, "%s", line_prefix);
1589                        show_name(options->file, prefix, name, len);
1590                        fprintf(options->file, "  Bin ");
1591                        fprintf(options->file, "%s%"PRIuMAX"%s",
1592                                del_c, deleted, reset);
1593                        fprintf(options->file, " -> ");
1594                        fprintf(options->file, "%s%"PRIuMAX"%s",
1595                                add_c, added, reset);
1596                        fprintf(options->file, " bytes");
1597                        fprintf(options->file, "\n");
1598                        continue;
1599                }
1600                else if (data->files[i]->is_unmerged) {
1601                        fprintf(options->file, "%s", line_prefix);
1602                        show_name(options->file, prefix, name, len);
1603                        fprintf(options->file, "  Unmerged\n");
1604                        continue;
1605                }
1606
1607                /*
1608                 * scale the add/delete
1609                 */
1610                add = added;
1611                del = deleted;
1612                adds += add;
1613                dels += del;
1614
1615                if (graph_width <= max_change) {
1616                        int total = add + del;
1617
1618                        total = scale_linear(add + del, graph_width, max_change);
1619                        if (total < 2 && add && del)
1620                                /* width >= 2 due to the sanity check */
1621                                total = 2;
1622                        if (add < del) {
1623                                add = scale_linear(add, graph_width, max_change);
1624                                del = total - add;
1625                        } else {
1626                                del = scale_linear(del, graph_width, max_change);
1627                                add = total - del;
1628                        }
1629                }
1630                fprintf(options->file, "%s", line_prefix);
1631                show_name(options->file, prefix, name, len);
1632                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1633                                added + deleted ? " " : "");
1634                show_graph(options->file, '+', add, add_c, reset);
1635                show_graph(options->file, '-', del, del_c, reset);
1636                fprintf(options->file, "\n");
1637        }
1638        for (i = count; i < data->nr; i++) {
1639                uintmax_t added = data->files[i]->added;
1640                uintmax_t deleted = data->files[i]->deleted;
1641                if (!data->files[i]->is_renamed &&
1642                         (added + deleted == 0)) {
1643                        total_files--;
1644                        continue;
1645                }
1646                adds += added;
1647                dels += deleted;
1648                if (!extra_shown)
1649                        fprintf(options->file, "%s ...\n", line_prefix);
1650                extra_shown = 1;
1651        }
1652        fprintf(options->file, "%s", line_prefix);
1653        print_stat_summary(options->file, total_files, adds, dels);
1654}
1655
1656static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1657{
1658        int i, adds = 0, dels = 0, total_files = data->nr;
1659
1660        if (data->nr == 0)
1661                return;
1662
1663        for (i = 0; i < data->nr; i++) {
1664                if (!data->files[i]->is_binary &&
1665                    !data->files[i]->is_unmerged) {
1666                        int added = data->files[i]->added;
1667                        int deleted= data->files[i]->deleted;
1668                        if (!data->files[i]->is_renamed &&
1669                            (added + deleted == 0)) {
1670                                total_files--;
1671                        } else {
1672                                adds += added;
1673                                dels += deleted;
1674                        }
1675                }
1676        }
1677        if (options->output_prefix) {
1678                struct strbuf *msg = NULL;
1679                msg = options->output_prefix(options,
1680                                options->output_prefix_data);
1681                fprintf(options->file, "%s", msg->buf);
1682        }
1683        print_stat_summary(options->file, total_files, adds, dels);
1684}
1685
1686static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1687{
1688        int i;
1689
1690        if (data->nr == 0)
1691                return;
1692
1693        for (i = 0; i < data->nr; i++) {
1694                struct diffstat_file *file = data->files[i];
1695
1696                if (options->output_prefix) {
1697                        struct strbuf *msg = NULL;
1698                        msg = options->output_prefix(options,
1699                                        options->output_prefix_data);
1700                        fprintf(options->file, "%s", msg->buf);
1701                }
1702
1703                if (file->is_binary)
1704                        fprintf(options->file, "-\t-\t");
1705                else
1706                        fprintf(options->file,
1707                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1708                                file->added, file->deleted);
1709                if (options->line_termination) {
1710                        fill_print_name(file);
1711                        if (!file->is_renamed)
1712                                write_name_quoted(file->name, options->file,
1713                                                  options->line_termination);
1714                        else {
1715                                fputs(file->print_name, options->file);
1716                                putc(options->line_termination, options->file);
1717                        }
1718                } else {
1719                        if (file->is_renamed) {
1720                                putc('\0', options->file);
1721                                write_name_quoted(file->from_name, options->file, '\0');
1722                        }
1723                        write_name_quoted(file->name, options->file, '\0');
1724                }
1725        }
1726}
1727
1728struct dirstat_file {
1729        const char *name;
1730        unsigned long changed;
1731};
1732
1733struct dirstat_dir {
1734        struct dirstat_file *files;
1735        int alloc, nr, permille, cumulative;
1736};
1737
1738static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1739                unsigned long changed, const char *base, int baselen)
1740{
1741        unsigned long this_dir = 0;
1742        unsigned int sources = 0;
1743        const char *line_prefix = "";
1744        struct strbuf *msg = NULL;
1745
1746        if (opt->output_prefix) {
1747                msg = opt->output_prefix(opt, opt->output_prefix_data);
1748                line_prefix = msg->buf;
1749        }
1750
1751        while (dir->nr) {
1752                struct dirstat_file *f = dir->files;
1753                int namelen = strlen(f->name);
1754                unsigned long this;
1755                char *slash;
1756
1757                if (namelen < baselen)
1758                        break;
1759                if (memcmp(f->name, base, baselen))
1760                        break;
1761                slash = strchr(f->name + baselen, '/');
1762                if (slash) {
1763                        int newbaselen = slash + 1 - f->name;
1764                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1765                        sources++;
1766                } else {
1767                        this = f->changed;
1768                        dir->files++;
1769                        dir->nr--;
1770                        sources += 2;
1771                }
1772                this_dir += this;
1773        }
1774
1775        /*
1776         * We don't report dirstat's for
1777         *  - the top level
1778         *  - or cases where everything came from a single directory
1779         *    under this directory (sources == 1).
1780         */
1781        if (baselen && sources != 1) {
1782                if (this_dir) {
1783                        int permille = this_dir * 1000 / changed;
1784                        if (permille >= dir->permille) {
1785                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1786                                        permille / 10, permille % 10, baselen, base);
1787                                if (!dir->cumulative)
1788                                        return 0;
1789                        }
1790                }
1791        }
1792        return this_dir;
1793}
1794
1795static int dirstat_compare(const void *_a, const void *_b)
1796{
1797        const struct dirstat_file *a = _a;
1798        const struct dirstat_file *b = _b;
1799        return strcmp(a->name, b->name);
1800}
1801
1802static void show_dirstat(struct diff_options *options)
1803{
1804        int i;
1805        unsigned long changed;
1806        struct dirstat_dir dir;
1807        struct diff_queue_struct *q = &diff_queued_diff;
1808
1809        dir.files = NULL;
1810        dir.alloc = 0;
1811        dir.nr = 0;
1812        dir.permille = options->dirstat_permille;
1813        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1814
1815        changed = 0;
1816        for (i = 0; i < q->nr; i++) {
1817                struct diff_filepair *p = q->queue[i];
1818                const char *name;
1819                unsigned long copied, added, damage;
1820                int content_changed;
1821
1822                name = p->two->path ? p->two->path : p->one->path;
1823
1824                if (p->one->sha1_valid && p->two->sha1_valid)
1825                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1826                else
1827                        content_changed = 1;
1828
1829                if (!content_changed) {
1830                        /*
1831                         * The SHA1 has not changed, so pre-/post-content is
1832                         * identical. We can therefore skip looking at the
1833                         * file contents altogether.
1834                         */
1835                        damage = 0;
1836                        goto found_damage;
1837                }
1838
1839                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1840                        /*
1841                         * In --dirstat-by-file mode, we don't really need to
1842                         * look at the actual file contents at all.
1843                         * The fact that the SHA1 changed is enough for us to
1844                         * add this file to the list of results
1845                         * (with each file contributing equal damage).
1846                         */
1847                        damage = 1;
1848                        goto found_damage;
1849                }
1850
1851                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1852                        diff_populate_filespec(p->one, 0);
1853                        diff_populate_filespec(p->two, 0);
1854                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1855                                               &copied, &added);
1856                        diff_free_filespec_data(p->one);
1857                        diff_free_filespec_data(p->two);
1858                } else if (DIFF_FILE_VALID(p->one)) {
1859                        diff_populate_filespec(p->one, 1);
1860                        copied = added = 0;
1861                        diff_free_filespec_data(p->one);
1862                } else if (DIFF_FILE_VALID(p->two)) {
1863                        diff_populate_filespec(p->two, 1);
1864                        copied = 0;
1865                        added = p->two->size;
1866                        diff_free_filespec_data(p->two);
1867                } else
1868                        continue;
1869
1870                /*
1871                 * Original minus copied is the removed material,
1872                 * added is the new material.  They are both damages
1873                 * made to the preimage.
1874                 * If the resulting damage is zero, we know that
1875                 * diffcore_count_changes() considers the two entries to
1876                 * be identical, but since content_changed is true, we
1877                 * know that there must have been _some_ kind of change,
1878                 * so we force all entries to have damage > 0.
1879                 */
1880                damage = (p->one->size - copied) + added;
1881                if (!damage)
1882                        damage = 1;
1883
1884found_damage:
1885                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1886                dir.files[dir.nr].name = name;
1887                dir.files[dir.nr].changed = damage;
1888                changed += damage;
1889                dir.nr++;
1890        }
1891
1892        /* This can happen even with many files, if everything was renames */
1893        if (!changed)
1894                return;
1895
1896        /* Show all directories with more than x% of the changes */
1897        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1898        gather_dirstat(options, &dir, changed, "", 0);
1899}
1900
1901static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1902{
1903        int i;
1904        unsigned long changed;
1905        struct dirstat_dir dir;
1906
1907        if (data->nr == 0)
1908                return;
1909
1910        dir.files = NULL;
1911        dir.alloc = 0;
1912        dir.nr = 0;
1913        dir.permille = options->dirstat_permille;
1914        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1915
1916        changed = 0;
1917        for (i = 0; i < data->nr; i++) {
1918                struct diffstat_file *file = data->files[i];
1919                unsigned long damage = file->added + file->deleted;
1920                if (file->is_binary)
1921                        /*
1922                         * binary files counts bytes, not lines. Must find some
1923                         * way to normalize binary bytes vs. textual lines.
1924                         * The following heuristic assumes that there are 64
1925                         * bytes per "line".
1926                         * This is stupid and ugly, but very cheap...
1927                         */
1928                        damage = (damage + 63) / 64;
1929                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1930                dir.files[dir.nr].name = file->name;
1931                dir.files[dir.nr].changed = damage;
1932                changed += damage;
1933                dir.nr++;
1934        }
1935
1936        /* This can happen even with many files, if everything was renames */
1937        if (!changed)
1938                return;
1939
1940        /* Show all directories with more than x% of the changes */
1941        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1942        gather_dirstat(options, &dir, changed, "", 0);
1943}
1944
1945static void free_diffstat_info(struct diffstat_t *diffstat)
1946{
1947        int i;
1948        for (i = 0; i < diffstat->nr; i++) {
1949                struct diffstat_file *f = diffstat->files[i];
1950                if (f->name != f->print_name)
1951                        free(f->print_name);
1952                free(f->name);
1953                free(f->from_name);
1954                free(f);
1955        }
1956        free(diffstat->files);
1957}
1958
1959struct checkdiff_t {
1960        const char *filename;
1961        int lineno;
1962        int conflict_marker_size;
1963        struct diff_options *o;
1964        unsigned ws_rule;
1965        unsigned status;
1966};
1967
1968static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1969{
1970        char firstchar;
1971        int cnt;
1972
1973        if (len < marker_size + 1)
1974                return 0;
1975        firstchar = line[0];
1976        switch (firstchar) {
1977        case '=': case '>': case '<': case '|':
1978                break;
1979        default:
1980                return 0;
1981        }
1982        for (cnt = 1; cnt < marker_size; cnt++)
1983                if (line[cnt] != firstchar)
1984                        return 0;
1985        /* line[1] thru line[marker_size-1] are same as firstchar */
1986        if (len < marker_size + 1 || !isspace(line[marker_size]))
1987                return 0;
1988        return 1;
1989}
1990
1991static void checkdiff_consume(void *priv, char *line, unsigned long len)
1992{
1993        struct checkdiff_t *data = priv;
1994        int marker_size = data->conflict_marker_size;
1995        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
1996        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
1997        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
1998        char *err;
1999        char *line_prefix = "";
2000        struct strbuf *msgbuf;
2001
2002        assert(data->o);
2003        if (data->o->output_prefix) {
2004                msgbuf = data->o->output_prefix(data->o,
2005                        data->o->output_prefix_data);
2006                line_prefix = msgbuf->buf;
2007        }
2008
2009        if (line[0] == '+') {
2010                unsigned bad;
2011                data->lineno++;
2012                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2013                        data->status |= 1;
2014                        fprintf(data->o->file,
2015                                "%s%s:%d: leftover conflict marker\n",
2016                                line_prefix, data->filename, data->lineno);
2017                }
2018                bad = ws_check(line + 1, len - 1, data->ws_rule);
2019                if (!bad)
2020                        return;
2021                data->status |= bad;
2022                err = whitespace_error_string(bad);
2023                fprintf(data->o->file, "%s%s:%d: %s.\n",
2024                        line_prefix, data->filename, data->lineno, err);
2025                free(err);
2026                emit_line(data->o, set, reset, line, 1);
2027                ws_check_emit(line + 1, len - 1, data->ws_rule,
2028                              data->o->file, set, reset, ws);
2029        } else if (line[0] == ' ') {
2030                data->lineno++;
2031        } else if (line[0] == '@') {
2032                char *plus = strchr(line, '+');
2033                if (plus)
2034                        data->lineno = strtol(plus, NULL, 10) - 1;
2035                else
2036                        die("invalid diff");
2037        }
2038}
2039
2040static unsigned char *deflate_it(char *data,
2041                                 unsigned long size,
2042                                 unsigned long *result_size)
2043{
2044        int bound;
2045        unsigned char *deflated;
2046        git_zstream stream;
2047
2048        memset(&stream, 0, sizeof(stream));
2049        git_deflate_init(&stream, zlib_compression_level);
2050        bound = git_deflate_bound(&stream, size);
2051        deflated = xmalloc(bound);
2052        stream.next_out = deflated;
2053        stream.avail_out = bound;
2054
2055        stream.next_in = (unsigned char *)data;
2056        stream.avail_in = size;
2057        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2058                ; /* nothing */
2059        git_deflate_end(&stream);
2060        *result_size = stream.total_out;
2061        return deflated;
2062}
2063
2064static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2065{
2066        void *cp;
2067        void *delta;
2068        void *deflated;
2069        void *data;
2070        unsigned long orig_size;
2071        unsigned long delta_size;
2072        unsigned long deflate_size;
2073        unsigned long data_size;
2074
2075        /* We could do deflated delta, or we could do just deflated two,
2076         * whichever is smaller.
2077         */
2078        delta = NULL;
2079        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2080        if (one->size && two->size) {
2081                delta = diff_delta(one->ptr, one->size,
2082                                   two->ptr, two->size,
2083                                   &delta_size, deflate_size);
2084                if (delta) {
2085                        void *to_free = delta;
2086                        orig_size = delta_size;
2087                        delta = deflate_it(delta, delta_size, &delta_size);
2088                        free(to_free);
2089                }
2090        }
2091
2092        if (delta && delta_size < deflate_size) {
2093                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2094                free(deflated);
2095                data = delta;
2096                data_size = delta_size;
2097        }
2098        else {
2099                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2100                free(delta);
2101                data = deflated;
2102                data_size = deflate_size;
2103        }
2104
2105        /* emit data encoded in base85 */
2106        cp = data;
2107        while (data_size) {
2108                int bytes = (52 < data_size) ? 52 : data_size;
2109                char line[70];
2110                data_size -= bytes;
2111                if (bytes <= 26)
2112                        line[0] = bytes + 'A' - 1;
2113                else
2114                        line[0] = bytes - 26 + 'a' - 1;
2115                encode_85(line + 1, cp, bytes);
2116                cp = (char *) cp + bytes;
2117                fprintf(file, "%s", prefix);
2118                fputs(line, file);
2119                fputc('\n', file);
2120        }
2121        fprintf(file, "%s\n", prefix);
2122        free(data);
2123}
2124
2125static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2126{
2127        fprintf(file, "%sGIT binary patch\n", prefix);
2128        emit_binary_diff_body(file, one, two, prefix);
2129        emit_binary_diff_body(file, two, one, prefix);
2130}
2131
2132int diff_filespec_is_binary(struct diff_filespec *one)
2133{
2134        if (one->is_binary == -1) {
2135                diff_filespec_load_driver(one);
2136                if (one->driver->binary != -1)
2137                        one->is_binary = one->driver->binary;
2138                else {
2139                        if (!one->data && DIFF_FILE_VALID(one))
2140                                diff_populate_filespec(one, 0);
2141                        if (one->data)
2142                                one->is_binary = buffer_is_binary(one->data,
2143                                                one->size);
2144                        if (one->is_binary == -1)
2145                                one->is_binary = 0;
2146                }
2147        }
2148        return one->is_binary;
2149}
2150
2151static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2152{
2153        diff_filespec_load_driver(one);
2154        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2155}
2156
2157void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2158{
2159        if (!options->a_prefix)
2160                options->a_prefix = a;
2161        if (!options->b_prefix)
2162                options->b_prefix = b;
2163}
2164
2165struct userdiff_driver *get_textconv(struct diff_filespec *one)
2166{
2167        if (!DIFF_FILE_VALID(one))
2168                return NULL;
2169
2170        diff_filespec_load_driver(one);
2171        return userdiff_get_textconv(one->driver);
2172}
2173
2174static void builtin_diff(const char *name_a,
2175                         const char *name_b,
2176                         struct diff_filespec *one,
2177                         struct diff_filespec *two,
2178                         const char *xfrm_msg,
2179                         int must_show_header,
2180                         struct diff_options *o,
2181                         int complete_rewrite)
2182{
2183        mmfile_t mf1, mf2;
2184        const char *lbl[2];
2185        char *a_one, *b_two;
2186        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2187        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2188        const char *a_prefix, *b_prefix;
2189        struct userdiff_driver *textconv_one = NULL;
2190        struct userdiff_driver *textconv_two = NULL;
2191        struct strbuf header = STRBUF_INIT;
2192        struct strbuf *msgbuf;
2193        char *line_prefix = "";
2194
2195        if (o->output_prefix) {
2196                msgbuf = o->output_prefix(o, o->output_prefix_data);
2197                line_prefix = msgbuf->buf;
2198        }
2199
2200        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2201                        (!one->mode || S_ISGITLINK(one->mode)) &&
2202                        (!two->mode || S_ISGITLINK(two->mode))) {
2203                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2204                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2205                show_submodule_summary(o->file, one ? one->path : two->path,
2206                                one->sha1, two->sha1, two->dirty_submodule,
2207                                del, add, reset);
2208                return;
2209        }
2210
2211        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2212                textconv_one = get_textconv(one);
2213                textconv_two = get_textconv(two);
2214        }
2215
2216        diff_set_mnemonic_prefix(o, "a/", "b/");
2217        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2218                a_prefix = o->b_prefix;
2219                b_prefix = o->a_prefix;
2220        } else {
2221                a_prefix = o->a_prefix;
2222                b_prefix = o->b_prefix;
2223        }
2224
2225        /* Never use a non-valid filename anywhere if at all possible */
2226        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2227        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2228
2229        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2230        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2231        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2232        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2233        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2234        if (lbl[0][0] == '/') {
2235                /* /dev/null */
2236                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2237                if (xfrm_msg)
2238                        strbuf_addstr(&header, xfrm_msg);
2239                must_show_header = 1;
2240        }
2241        else if (lbl[1][0] == '/') {
2242                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2243                if (xfrm_msg)
2244                        strbuf_addstr(&header, xfrm_msg);
2245                must_show_header = 1;
2246        }
2247        else {
2248                if (one->mode != two->mode) {
2249                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2250                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2251                        must_show_header = 1;
2252                }
2253                if (xfrm_msg)
2254                        strbuf_addstr(&header, xfrm_msg);
2255
2256                /*
2257                 * we do not run diff between different kind
2258                 * of objects.
2259                 */
2260                if ((one->mode ^ two->mode) & S_IFMT)
2261                        goto free_ab_and_return;
2262                if (complete_rewrite &&
2263                    (textconv_one || !diff_filespec_is_binary(one)) &&
2264                    (textconv_two || !diff_filespec_is_binary(two))) {
2265                        fprintf(o->file, "%s", header.buf);
2266                        strbuf_reset(&header);
2267                        emit_rewrite_diff(name_a, name_b, one, two,
2268                                                textconv_one, textconv_two, o);
2269                        o->found_changes = 1;
2270                        goto free_ab_and_return;
2271                }
2272        }
2273
2274        if (o->irreversible_delete && lbl[1][0] == '/') {
2275                fprintf(o->file, "%s", header.buf);
2276                strbuf_reset(&header);
2277                goto free_ab_and_return;
2278        } else if (!DIFF_OPT_TST(o, TEXT) &&
2279            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2280              (!textconv_two && diff_filespec_is_binary(two)) )) {
2281                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2282                        die("unable to read files to diff");
2283                /* Quite common confusing case */
2284                if (mf1.size == mf2.size &&
2285                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2286                        if (must_show_header)
2287                                fprintf(o->file, "%s", header.buf);
2288                        goto free_ab_and_return;
2289                }
2290                fprintf(o->file, "%s", header.buf);
2291                strbuf_reset(&header);
2292                if (DIFF_OPT_TST(o, BINARY))
2293                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2294                else
2295                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2296                                line_prefix, lbl[0], lbl[1]);
2297                o->found_changes = 1;
2298        } else {
2299                /* Crazy xdl interfaces.. */
2300                const char *diffopts = getenv("GIT_DIFF_OPTS");
2301                xpparam_t xpp;
2302                xdemitconf_t xecfg;
2303                struct emit_callback ecbdata;
2304                const struct userdiff_funcname *pe;
2305
2306                if (must_show_header) {
2307                        fprintf(o->file, "%s", header.buf);
2308                        strbuf_reset(&header);
2309                }
2310
2311                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2312                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2313
2314                pe = diff_funcname_pattern(one);
2315                if (!pe)
2316                        pe = diff_funcname_pattern(two);
2317
2318                memset(&xpp, 0, sizeof(xpp));
2319                memset(&xecfg, 0, sizeof(xecfg));
2320                memset(&ecbdata, 0, sizeof(ecbdata));
2321                ecbdata.label_path = lbl;
2322                ecbdata.color_diff = want_color(o->use_color);
2323                ecbdata.found_changesp = &o->found_changes;
2324                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2325                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2326                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2327                ecbdata.opt = o;
2328                ecbdata.header = header.len ? &header : NULL;
2329                xpp.flags = o->xdl_opts;
2330                xecfg.ctxlen = o->context;
2331                xecfg.interhunkctxlen = o->interhunkcontext;
2332                xecfg.flags = XDL_EMIT_FUNCNAMES;
2333                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2334                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2335                if (pe)
2336                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2337                if (!diffopts)
2338                        ;
2339                else if (!prefixcmp(diffopts, "--unified="))
2340                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2341                else if (!prefixcmp(diffopts, "-u"))
2342                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2343                if (o->word_diff)
2344                        init_diff_words_data(&ecbdata, o, one, two);
2345                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2346                              &xpp, &xecfg);
2347                if (o->word_diff)
2348                        free_diff_words_data(&ecbdata);
2349                if (textconv_one)
2350                        free(mf1.ptr);
2351                if (textconv_two)
2352                        free(mf2.ptr);
2353                xdiff_clear_find_func(&xecfg);
2354        }
2355
2356 free_ab_and_return:
2357        strbuf_release(&header);
2358        diff_free_filespec_data(one);
2359        diff_free_filespec_data(two);
2360        free(a_one);
2361        free(b_two);
2362        return;
2363}
2364
2365static void builtin_diffstat(const char *name_a, const char *name_b,
2366                             struct diff_filespec *one,
2367                             struct diff_filespec *two,
2368                             struct diffstat_t *diffstat,
2369                             struct diff_options *o,
2370                             int complete_rewrite)
2371{
2372        mmfile_t mf1, mf2;
2373        struct diffstat_file *data;
2374
2375        data = diffstat_add(diffstat, name_a, name_b);
2376
2377        if (!one || !two) {
2378                data->is_unmerged = 1;
2379                return;
2380        }
2381
2382        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2383                data->is_binary = 1;
2384                data->added = diff_filespec_size(two);
2385                data->deleted = diff_filespec_size(one);
2386        }
2387
2388        else if (complete_rewrite) {
2389                diff_populate_filespec(one, 0);
2390                diff_populate_filespec(two, 0);
2391                data->deleted = count_lines(one->data, one->size);
2392                data->added = count_lines(two->data, two->size);
2393        }
2394
2395        else {
2396                /* Crazy xdl interfaces.. */
2397                xpparam_t xpp;
2398                xdemitconf_t xecfg;
2399
2400                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2401                        die("unable to read files to diff");
2402
2403                memset(&xpp, 0, sizeof(xpp));
2404                memset(&xecfg, 0, sizeof(xecfg));
2405                xpp.flags = o->xdl_opts;
2406                xecfg.ctxlen = o->context;
2407                xecfg.interhunkctxlen = o->interhunkcontext;
2408                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2409                              &xpp, &xecfg);
2410        }
2411
2412        diff_free_filespec_data(one);
2413        diff_free_filespec_data(two);
2414}
2415
2416static void builtin_checkdiff(const char *name_a, const char *name_b,
2417                              const char *attr_path,
2418                              struct diff_filespec *one,
2419                              struct diff_filespec *two,
2420                              struct diff_options *o)
2421{
2422        mmfile_t mf1, mf2;
2423        struct checkdiff_t data;
2424
2425        if (!two)
2426                return;
2427
2428        memset(&data, 0, sizeof(data));
2429        data.filename = name_b ? name_b : name_a;
2430        data.lineno = 0;
2431        data.o = o;
2432        data.ws_rule = whitespace_rule(attr_path);
2433        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2434
2435        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2436                die("unable to read files to diff");
2437
2438        /*
2439         * All the other codepaths check both sides, but not checking
2440         * the "old" side here is deliberate.  We are checking the newly
2441         * introduced changes, and as long as the "new" side is text, we
2442         * can and should check what it introduces.
2443         */
2444        if (diff_filespec_is_binary(two))
2445                goto free_and_return;
2446        else {
2447                /* Crazy xdl interfaces.. */
2448                xpparam_t xpp;
2449                xdemitconf_t xecfg;
2450
2451                memset(&xpp, 0, sizeof(xpp));
2452                memset(&xecfg, 0, sizeof(xecfg));
2453                xecfg.ctxlen = 1; /* at least one context line */
2454                xpp.flags = 0;
2455                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2456                              &xpp, &xecfg);
2457
2458                if (data.ws_rule & WS_BLANK_AT_EOF) {
2459                        struct emit_callback ecbdata;
2460                        int blank_at_eof;
2461
2462                        ecbdata.ws_rule = data.ws_rule;
2463                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2464                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2465
2466                        if (blank_at_eof) {
2467                                static char *err;
2468                                if (!err)
2469                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2470                                fprintf(o->file, "%s:%d: %s.\n",
2471                                        data.filename, blank_at_eof, err);
2472                                data.status = 1; /* report errors */
2473                        }
2474                }
2475        }
2476 free_and_return:
2477        diff_free_filespec_data(one);
2478        diff_free_filespec_data(two);
2479        if (data.status)
2480                DIFF_OPT_SET(o, CHECK_FAILED);
2481}
2482
2483struct diff_filespec *alloc_filespec(const char *path)
2484{
2485        int namelen = strlen(path);
2486        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2487
2488        memset(spec, 0, sizeof(*spec));
2489        spec->path = (char *)(spec + 1);
2490        memcpy(spec->path, path, namelen+1);
2491        spec->count = 1;
2492        spec->is_binary = -1;
2493        return spec;
2494}
2495
2496void free_filespec(struct diff_filespec *spec)
2497{
2498        if (!--spec->count) {
2499                diff_free_filespec_data(spec);
2500                free(spec);
2501        }
2502}
2503
2504void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2505                   unsigned short mode)
2506{
2507        if (mode) {
2508                spec->mode = canon_mode(mode);
2509                hashcpy(spec->sha1, sha1);
2510                spec->sha1_valid = !is_null_sha1(sha1);
2511        }
2512}
2513
2514/*
2515 * Given a name and sha1 pair, if the index tells us the file in
2516 * the work tree has that object contents, return true, so that
2517 * prepare_temp_file() does not have to inflate and extract.
2518 */
2519static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2520{
2521        struct cache_entry *ce;
2522        struct stat st;
2523        int pos, len;
2524
2525        /*
2526         * We do not read the cache ourselves here, because the
2527         * benchmark with my previous version that always reads cache
2528         * shows that it makes things worse for diff-tree comparing
2529         * two linux-2.6 kernel trees in an already checked out work
2530         * tree.  This is because most diff-tree comparisons deal with
2531         * only a small number of files, while reading the cache is
2532         * expensive for a large project, and its cost outweighs the
2533         * savings we get by not inflating the object to a temporary
2534         * file.  Practically, this code only helps when we are used
2535         * by diff-cache --cached, which does read the cache before
2536         * calling us.
2537         */
2538        if (!active_cache)
2539                return 0;
2540
2541        /* We want to avoid the working directory if our caller
2542         * doesn't need the data in a normal file, this system
2543         * is rather slow with its stat/open/mmap/close syscalls,
2544         * and the object is contained in a pack file.  The pack
2545         * is probably already open and will be faster to obtain
2546         * the data through than the working directory.  Loose
2547         * objects however would tend to be slower as they need
2548         * to be individually opened and inflated.
2549         */
2550        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2551                return 0;
2552
2553        len = strlen(name);
2554        pos = cache_name_pos(name, len);
2555        if (pos < 0)
2556                return 0;
2557        ce = active_cache[pos];
2558
2559        /*
2560         * This is not the sha1 we are looking for, or
2561         * unreusable because it is not a regular file.
2562         */
2563        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2564                return 0;
2565
2566        /*
2567         * If ce is marked as "assume unchanged", there is no
2568         * guarantee that work tree matches what we are looking for.
2569         */
2570        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2571                return 0;
2572
2573        /*
2574         * If ce matches the file in the work tree, we can reuse it.
2575         */
2576        if (ce_uptodate(ce) ||
2577            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2578                return 1;
2579
2580        return 0;
2581}
2582
2583static int populate_from_stdin(struct diff_filespec *s)
2584{
2585        struct strbuf buf = STRBUF_INIT;
2586        size_t size = 0;
2587
2588        if (strbuf_read(&buf, 0, 0) < 0)
2589                return error("error while reading from stdin %s",
2590                                     strerror(errno));
2591
2592        s->should_munmap = 0;
2593        s->data = strbuf_detach(&buf, &size);
2594        s->size = size;
2595        s->should_free = 1;
2596        return 0;
2597}
2598
2599static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2600{
2601        int len;
2602        char *data = xmalloc(100), *dirty = "";
2603
2604        /* Are we looking at the work tree? */
2605        if (s->dirty_submodule)
2606                dirty = "-dirty";
2607
2608        len = snprintf(data, 100,
2609                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2610        s->data = data;
2611        s->size = len;
2612        s->should_free = 1;
2613        if (size_only) {
2614                s->data = NULL;
2615                free(data);
2616        }
2617        return 0;
2618}
2619
2620/*
2621 * While doing rename detection and pickaxe operation, we may need to
2622 * grab the data for the blob (or file) for our own in-core comparison.
2623 * diff_filespec has data and size fields for this purpose.
2624 */
2625int diff_populate_filespec(struct diff_filespec *s, int size_only)
2626{
2627        int err = 0;
2628        if (!DIFF_FILE_VALID(s))
2629                die("internal error: asking to populate invalid file.");
2630        if (S_ISDIR(s->mode))
2631                return -1;
2632
2633        if (s->data)
2634                return 0;
2635
2636        if (size_only && 0 < s->size)
2637                return 0;
2638
2639        if (S_ISGITLINK(s->mode))
2640                return diff_populate_gitlink(s, size_only);
2641
2642        if (!s->sha1_valid ||
2643            reuse_worktree_file(s->path, s->sha1, 0)) {
2644                struct strbuf buf = STRBUF_INIT;
2645                struct stat st;
2646                int fd;
2647
2648                if (!strcmp(s->path, "-"))
2649                        return populate_from_stdin(s);
2650
2651                if (lstat(s->path, &st) < 0) {
2652                        if (errno == ENOENT) {
2653                        err_empty:
2654                                err = -1;
2655                        empty:
2656                                s->data = (char *)"";
2657                                s->size = 0;
2658                                return err;
2659                        }
2660                }
2661                s->size = xsize_t(st.st_size);
2662                if (!s->size)
2663                        goto empty;
2664                if (S_ISLNK(st.st_mode)) {
2665                        struct strbuf sb = STRBUF_INIT;
2666
2667                        if (strbuf_readlink(&sb, s->path, s->size))
2668                                goto err_empty;
2669                        s->size = sb.len;
2670                        s->data = strbuf_detach(&sb, NULL);
2671                        s->should_free = 1;
2672                        return 0;
2673                }
2674                if (size_only)
2675                        return 0;
2676                fd = open(s->path, O_RDONLY);
2677                if (fd < 0)
2678                        goto err_empty;
2679                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2680                close(fd);
2681                s->should_munmap = 1;
2682
2683                /*
2684                 * Convert from working tree format to canonical git format
2685                 */
2686                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2687                        size_t size = 0;
2688                        munmap(s->data, s->size);
2689                        s->should_munmap = 0;
2690                        s->data = strbuf_detach(&buf, &size);
2691                        s->size = size;
2692                        s->should_free = 1;
2693                }
2694        }
2695        else {
2696                enum object_type type;
2697                if (size_only) {
2698                        type = sha1_object_info(s->sha1, &s->size);
2699                        if (type < 0)
2700                                die("unable to read %s", sha1_to_hex(s->sha1));
2701                } else {
2702                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2703                        if (!s->data)
2704                                die("unable to read %s", sha1_to_hex(s->sha1));
2705                        s->should_free = 1;
2706                }
2707        }
2708        return 0;
2709}
2710
2711void diff_free_filespec_blob(struct diff_filespec *s)
2712{
2713        if (s->should_free)
2714                free(s->data);
2715        else if (s->should_munmap)
2716                munmap(s->data, s->size);
2717
2718        if (s->should_free || s->should_munmap) {
2719                s->should_free = s->should_munmap = 0;
2720                s->data = NULL;
2721        }
2722}
2723
2724void diff_free_filespec_data(struct diff_filespec *s)
2725{
2726        diff_free_filespec_blob(s);
2727        free(s->cnt_data);
2728        s->cnt_data = NULL;
2729}
2730
2731static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2732                           void *blob,
2733                           unsigned long size,
2734                           const unsigned char *sha1,
2735                           int mode)
2736{
2737        int fd;
2738        struct strbuf buf = STRBUF_INIT;
2739        struct strbuf template = STRBUF_INIT;
2740        char *path_dup = xstrdup(path);
2741        const char *base = basename(path_dup);
2742
2743        /* Generate "XXXXXX_basename.ext" */
2744        strbuf_addstr(&template, "XXXXXX_");
2745        strbuf_addstr(&template, base);
2746
2747        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2748                        strlen(base) + 1);
2749        if (fd < 0)
2750                die_errno("unable to create temp-file");
2751        if (convert_to_working_tree(path,
2752                        (const char *)blob, (size_t)size, &buf)) {
2753                blob = buf.buf;
2754                size = buf.len;
2755        }
2756        if (write_in_full(fd, blob, size) != size)
2757                die_errno("unable to write temp-file");
2758        close(fd);
2759        temp->name = temp->tmp_path;
2760        strcpy(temp->hex, sha1_to_hex(sha1));
2761        temp->hex[40] = 0;
2762        sprintf(temp->mode, "%06o", mode);
2763        strbuf_release(&buf);
2764        strbuf_release(&template);
2765        free(path_dup);
2766}
2767
2768static struct diff_tempfile *prepare_temp_file(const char *name,
2769                struct diff_filespec *one)
2770{
2771        struct diff_tempfile *temp = claim_diff_tempfile();
2772
2773        if (!DIFF_FILE_VALID(one)) {
2774        not_a_valid_file:
2775                /* A '-' entry produces this for file-2, and
2776                 * a '+' entry produces this for file-1.
2777                 */
2778                temp->name = "/dev/null";
2779                strcpy(temp->hex, ".");
2780                strcpy(temp->mode, ".");
2781                return temp;
2782        }
2783
2784        if (!remove_tempfile_installed) {
2785                atexit(remove_tempfile);
2786                sigchain_push_common(remove_tempfile_on_signal);
2787                remove_tempfile_installed = 1;
2788        }
2789
2790        if (!one->sha1_valid ||
2791            reuse_worktree_file(name, one->sha1, 1)) {
2792                struct stat st;
2793                if (lstat(name, &st) < 0) {
2794                        if (errno == ENOENT)
2795                                goto not_a_valid_file;
2796                        die_errno("stat(%s)", name);
2797                }
2798                if (S_ISLNK(st.st_mode)) {
2799                        struct strbuf sb = STRBUF_INIT;
2800                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2801                                die_errno("readlink(%s)", name);
2802                        prep_temp_blob(name, temp, sb.buf, sb.len,
2803                                       (one->sha1_valid ?
2804                                        one->sha1 : null_sha1),
2805                                       (one->sha1_valid ?
2806                                        one->mode : S_IFLNK));
2807                        strbuf_release(&sb);
2808                }
2809                else {
2810                        /* we can borrow from the file in the work tree */
2811                        temp->name = name;
2812                        if (!one->sha1_valid)
2813                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2814                        else
2815                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2816                        /* Even though we may sometimes borrow the
2817                         * contents from the work tree, we always want
2818                         * one->mode.  mode is trustworthy even when
2819                         * !(one->sha1_valid), as long as
2820                         * DIFF_FILE_VALID(one).
2821                         */
2822                        sprintf(temp->mode, "%06o", one->mode);
2823                }
2824                return temp;
2825        }
2826        else {
2827                if (diff_populate_filespec(one, 0))
2828                        die("cannot read data blob for %s", one->path);
2829                prep_temp_blob(name, temp, one->data, one->size,
2830                               one->sha1, one->mode);
2831        }
2832        return temp;
2833}
2834
2835/* An external diff command takes:
2836 *
2837 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2838 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2839 *
2840 */
2841static void run_external_diff(const char *pgm,
2842                              const char *name,
2843                              const char *other,
2844                              struct diff_filespec *one,
2845                              struct diff_filespec *two,
2846                              const char *xfrm_msg,
2847                              int complete_rewrite)
2848{
2849        const char *spawn_arg[10];
2850        int retval;
2851        const char **arg = &spawn_arg[0];
2852
2853        if (one && two) {
2854                struct diff_tempfile *temp_one, *temp_two;
2855                const char *othername = (other ? other : name);
2856                temp_one = prepare_temp_file(name, one);
2857                temp_two = prepare_temp_file(othername, two);
2858                *arg++ = pgm;
2859                *arg++ = name;
2860                *arg++ = temp_one->name;
2861                *arg++ = temp_one->hex;
2862                *arg++ = temp_one->mode;
2863                *arg++ = temp_two->name;
2864                *arg++ = temp_two->hex;
2865                *arg++ = temp_two->mode;
2866                if (other) {
2867                        *arg++ = other;
2868                        *arg++ = xfrm_msg;
2869                }
2870        } else {
2871                *arg++ = pgm;
2872                *arg++ = name;
2873        }
2874        *arg = NULL;
2875        fflush(NULL);
2876        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2877        remove_tempfile();
2878        if (retval) {
2879                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2880                exit(1);
2881        }
2882}
2883
2884static int similarity_index(struct diff_filepair *p)
2885{
2886        return p->score * 100 / MAX_SCORE;
2887}
2888
2889static void fill_metainfo(struct strbuf *msg,
2890                          const char *name,
2891                          const char *other,
2892                          struct diff_filespec *one,
2893                          struct diff_filespec *two,
2894                          struct diff_options *o,
2895                          struct diff_filepair *p,
2896                          int *must_show_header,
2897                          int use_color)
2898{
2899        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2900        const char *reset = diff_get_color(use_color, DIFF_RESET);
2901        struct strbuf *msgbuf;
2902        char *line_prefix = "";
2903
2904        *must_show_header = 1;
2905        if (o->output_prefix) {
2906                msgbuf = o->output_prefix(o, o->output_prefix_data);
2907                line_prefix = msgbuf->buf;
2908        }
2909        strbuf_init(msg, PATH_MAX * 2 + 300);
2910        switch (p->status) {
2911        case DIFF_STATUS_COPIED:
2912                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2913                            line_prefix, set, similarity_index(p));
2914                strbuf_addf(msg, "%s\n%s%scopy from ",
2915                            reset,  line_prefix, set);
2916                quote_c_style(name, msg, NULL, 0);
2917                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2918                quote_c_style(other, msg, NULL, 0);
2919                strbuf_addf(msg, "%s\n", reset);
2920                break;
2921        case DIFF_STATUS_RENAMED:
2922                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2923                            line_prefix, set, similarity_index(p));
2924                strbuf_addf(msg, "%s\n%s%srename from ",
2925                            reset, line_prefix, set);
2926                quote_c_style(name, msg, NULL, 0);
2927                strbuf_addf(msg, "%s\n%s%srename to ",
2928                            reset, line_prefix, set);
2929                quote_c_style(other, msg, NULL, 0);
2930                strbuf_addf(msg, "%s\n", reset);
2931                break;
2932        case DIFF_STATUS_MODIFIED:
2933                if (p->score) {
2934                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2935                                    line_prefix,
2936                                    set, similarity_index(p), reset);
2937                        break;
2938                }
2939                /* fallthru */
2940        default:
2941                *must_show_header = 0;
2942        }
2943        if (one && two && hashcmp(one->sha1, two->sha1)) {
2944                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2945
2946                if (DIFF_OPT_TST(o, BINARY)) {
2947                        mmfile_t mf;
2948                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2949                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2950                                abbrev = 40;
2951                }
2952                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2953                            find_unique_abbrev(one->sha1, abbrev));
2954                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2955                if (one->mode == two->mode)
2956                        strbuf_addf(msg, " %06o", one->mode);
2957                strbuf_addf(msg, "%s\n", reset);
2958        }
2959}
2960
2961static void run_diff_cmd(const char *pgm,
2962                         const char *name,
2963                         const char *other,
2964                         const char *attr_path,
2965                         struct diff_filespec *one,
2966                         struct diff_filespec *two,
2967                         struct strbuf *msg,
2968                         struct diff_options *o,
2969                         struct diff_filepair *p)
2970{
2971        const char *xfrm_msg = NULL;
2972        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2973        int must_show_header = 0;
2974
2975        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2976                pgm = NULL;
2977        else {
2978                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2979                if (drv && drv->external)
2980                        pgm = drv->external;
2981        }
2982
2983        if (msg) {
2984                /*
2985                 * don't use colors when the header is intended for an
2986                 * external diff driver
2987                 */
2988                fill_metainfo(msg, name, other, one, two, o, p,
2989                              &must_show_header,
2990                              want_color(o->use_color) && !pgm);
2991                xfrm_msg = msg->len ? msg->buf : NULL;
2992        }
2993
2994        if (pgm) {
2995                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2996                                  complete_rewrite);
2997                return;
2998        }
2999        if (one && two)
3000                builtin_diff(name, other ? other : name,
3001                             one, two, xfrm_msg, must_show_header,
3002                             o, complete_rewrite);
3003        else
3004                fprintf(o->file, "* Unmerged path %s\n", name);
3005}
3006
3007static void diff_fill_sha1_info(struct diff_filespec *one)
3008{
3009        if (DIFF_FILE_VALID(one)) {
3010                if (!one->sha1_valid) {
3011                        struct stat st;
3012                        if (!strcmp(one->path, "-")) {
3013                                hashcpy(one->sha1, null_sha1);
3014                                return;
3015                        }
3016                        if (lstat(one->path, &st) < 0)
3017                                die_errno("stat '%s'", one->path);
3018                        if (index_path(one->sha1, one->path, &st, 0))
3019                                die("cannot hash %s", one->path);
3020                }
3021        }
3022        else
3023                hashclr(one->sha1);
3024}
3025
3026static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3027{
3028        /* Strip the prefix but do not molest /dev/null and absolute paths */
3029        if (*namep && **namep != '/') {
3030                *namep += prefix_length;
3031                if (**namep == '/')
3032                        ++*namep;
3033        }
3034        if (*otherp && **otherp != '/') {
3035                *otherp += prefix_length;
3036                if (**otherp == '/')
3037                        ++*otherp;
3038        }
3039}
3040
3041static void run_diff(struct diff_filepair *p, struct diff_options *o)
3042{
3043        const char *pgm = external_diff();
3044        struct strbuf msg;
3045        struct diff_filespec *one = p->one;
3046        struct diff_filespec *two = p->two;
3047        const char *name;
3048        const char *other;
3049        const char *attr_path;
3050
3051        name  = p->one->path;
3052        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3053        attr_path = name;
3054        if (o->prefix_length)
3055                strip_prefix(o->prefix_length, &name, &other);
3056
3057        if (DIFF_PAIR_UNMERGED(p)) {
3058                run_diff_cmd(pgm, name, NULL, attr_path,
3059                             NULL, NULL, NULL, o, p);
3060                return;
3061        }
3062
3063        diff_fill_sha1_info(one);
3064        diff_fill_sha1_info(two);
3065
3066        if (!pgm &&
3067            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3068            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3069                /*
3070                 * a filepair that changes between file and symlink
3071                 * needs to be split into deletion and creation.
3072                 */
3073                struct diff_filespec *null = alloc_filespec(two->path);
3074                run_diff_cmd(NULL, name, other, attr_path,
3075                             one, null, &msg, o, p);
3076                free(null);
3077                strbuf_release(&msg);
3078
3079                null = alloc_filespec(one->path);
3080                run_diff_cmd(NULL, name, other, attr_path,
3081                             null, two, &msg, o, p);
3082                free(null);
3083        }
3084        else
3085                run_diff_cmd(pgm, name, other, attr_path,
3086                             one, two, &msg, o, p);
3087
3088        strbuf_release(&msg);
3089}
3090
3091static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3092                         struct diffstat_t *diffstat)
3093{
3094        const char *name;
3095        const char *other;
3096        int complete_rewrite = 0;
3097
3098        if (DIFF_PAIR_UNMERGED(p)) {
3099                /* unmerged */
3100                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
3101                return;
3102        }
3103
3104        name = p->one->path;
3105        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3106
3107        if (o->prefix_length)
3108                strip_prefix(o->prefix_length, &name, &other);
3109
3110        diff_fill_sha1_info(p->one);
3111        diff_fill_sha1_info(p->two);
3112
3113        if (p->status == DIFF_STATUS_MODIFIED && p->score)
3114                complete_rewrite = 1;
3115        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
3116}
3117
3118static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3119{
3120        const char *name;
3121        const char *other;
3122        const char *attr_path;
3123
3124        if (DIFF_PAIR_UNMERGED(p)) {
3125                /* unmerged */
3126                return;
3127        }
3128
3129        name = p->one->path;
3130        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3131        attr_path = other ? other : name;
3132
3133        if (o->prefix_length)
3134                strip_prefix(o->prefix_length, &name, &other);
3135
3136        diff_fill_sha1_info(p->one);
3137        diff_fill_sha1_info(p->two);
3138
3139        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3140}
3141
3142void diff_setup(struct diff_options *options)
3143{
3144        memcpy(options, &default_diff_options, sizeof(*options));
3145
3146        options->file = stdout;
3147
3148        options->line_termination = '\n';
3149        options->break_opt = -1;
3150        options->rename_limit = -1;
3151        options->dirstat_permille = diff_dirstat_permille_default;
3152        options->context = 3;
3153        DIFF_OPT_SET(options, RENAME_EMPTY);
3154
3155        options->change = diff_change;
3156        options->add_remove = diff_addremove;
3157        options->use_color = diff_use_color_default;
3158        options->detect_rename = diff_detect_rename_default;
3159
3160        if (diff_no_prefix) {
3161                options->a_prefix = options->b_prefix = "";
3162        } else if (!diff_mnemonic_prefix) {
3163                options->a_prefix = "a/";
3164                options->b_prefix = "b/";
3165        }
3166}
3167
3168int diff_setup_done(struct diff_options *options)
3169{
3170        int count = 0;
3171
3172        if (options->output_format & DIFF_FORMAT_NAME)
3173                count++;
3174        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3175                count++;
3176        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3177                count++;
3178        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3179                count++;
3180        if (count > 1)
3181                die("--name-only, --name-status, --check and -s are mutually exclusive");
3182
3183        /*
3184         * Most of the time we can say "there are changes"
3185         * only by checking if there are changed paths, but
3186         * --ignore-whitespace* options force us to look
3187         * inside contents.
3188         */
3189
3190        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3191            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3192            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3193                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3194        else
3195                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3196
3197        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3198                options->detect_rename = DIFF_DETECT_COPY;
3199
3200        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3201                options->prefix = NULL;
3202        if (options->prefix)
3203                options->prefix_length = strlen(options->prefix);
3204        else
3205                options->prefix_length = 0;
3206
3207        if (options->output_format & (DIFF_FORMAT_NAME |
3208                                      DIFF_FORMAT_NAME_STATUS |
3209                                      DIFF_FORMAT_CHECKDIFF |
3210                                      DIFF_FORMAT_NO_OUTPUT))
3211                options->output_format &= ~(DIFF_FORMAT_RAW |
3212                                            DIFF_FORMAT_NUMSTAT |
3213                                            DIFF_FORMAT_DIFFSTAT |
3214                                            DIFF_FORMAT_SHORTSTAT |
3215                                            DIFF_FORMAT_DIRSTAT |
3216                                            DIFF_FORMAT_SUMMARY |
3217                                            DIFF_FORMAT_PATCH);
3218
3219        /*
3220         * These cases always need recursive; we do not drop caller-supplied
3221         * recursive bits for other formats here.
3222         */
3223        if (options->output_format & (DIFF_FORMAT_PATCH |
3224                                      DIFF_FORMAT_NUMSTAT |
3225                                      DIFF_FORMAT_DIFFSTAT |
3226                                      DIFF_FORMAT_SHORTSTAT |
3227                                      DIFF_FORMAT_DIRSTAT |
3228                                      DIFF_FORMAT_SUMMARY |
3229                                      DIFF_FORMAT_CHECKDIFF))
3230                DIFF_OPT_SET(options, RECURSIVE);
3231        /*
3232         * Also pickaxe would not work very well if you do not say recursive
3233         */
3234        if (options->pickaxe)
3235                DIFF_OPT_SET(options, RECURSIVE);
3236        /*
3237         * When patches are generated, submodules diffed against the work tree
3238         * must be checked for dirtiness too so it can be shown in the output
3239         */
3240        if (options->output_format & DIFF_FORMAT_PATCH)
3241                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3242
3243        if (options->detect_rename && options->rename_limit < 0)
3244                options->rename_limit = diff_rename_limit_default;
3245        if (options->setup & DIFF_SETUP_USE_CACHE) {
3246                if (!active_cache)
3247                        /* read-cache does not die even when it fails
3248                         * so it is safe for us to do this here.  Also
3249                         * it does not smudge active_cache or active_nr
3250                         * when it fails, so we do not have to worry about
3251                         * cleaning it up ourselves either.
3252                         */
3253                        read_cache();
3254        }
3255        if (options->abbrev <= 0 || 40 < options->abbrev)
3256                options->abbrev = 40; /* full */
3257
3258        /*
3259         * It does not make sense to show the first hit we happened
3260         * to have found.  It does not make sense not to return with
3261         * exit code in such a case either.
3262         */
3263        if (DIFF_OPT_TST(options, QUICK)) {
3264                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3265                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3266        }
3267
3268        return 0;
3269}
3270
3271static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3272{
3273        char c, *eq;
3274        int len;
3275
3276        if (*arg != '-')
3277                return 0;
3278        c = *++arg;
3279        if (!c)
3280                return 0;
3281        if (c == arg_short) {
3282                c = *++arg;
3283                if (!c)
3284                        return 1;
3285                if (val && isdigit(c)) {
3286                        char *end;
3287                        int n = strtoul(arg, &end, 10);
3288                        if (*end)
3289                                return 0;
3290                        *val = n;
3291                        return 1;
3292                }
3293                return 0;
3294        }
3295        if (c != '-')
3296                return 0;
3297        arg++;
3298        eq = strchr(arg, '=');
3299        if (eq)
3300                len = eq - arg;
3301        else
3302                len = strlen(arg);
3303        if (!len || strncmp(arg, arg_long, len))
3304                return 0;
3305        if (eq) {
3306                int n;
3307                char *end;
3308                if (!isdigit(*++eq))
3309                        return 0;
3310                n = strtoul(eq, &end, 10);
3311                if (*end)
3312                        return 0;
3313                *val = n;
3314        }
3315        return 1;
3316}
3317
3318static int diff_scoreopt_parse(const char *opt);
3319
3320static inline int short_opt(char opt, const char **argv,
3321                            const char **optarg)
3322{
3323        const char *arg = argv[0];
3324        if (arg[0] != '-' || arg[1] != opt)
3325                return 0;
3326        if (arg[2] != '\0') {
3327                *optarg = arg + 2;
3328                return 1;
3329        }
3330        if (!argv[1])
3331                die("Option '%c' requires a value", opt);
3332        *optarg = argv[1];
3333        return 2;
3334}
3335
3336int parse_long_opt(const char *opt, const char **argv,
3337                   const char **optarg)
3338{
3339        const char *arg = argv[0];
3340        if (arg[0] != '-' || arg[1] != '-')
3341                return 0;
3342        arg += strlen("--");
3343        if (prefixcmp(arg, opt))
3344                return 0;
3345        arg += strlen(opt);
3346        if (*arg == '=') { /* sticked form: --option=value */
3347                *optarg = arg + 1;
3348                return 1;
3349        }
3350        if (*arg != '\0')
3351                return 0;
3352        /* separate form: --option value */
3353        if (!argv[1])
3354                die("Option '--%s' requires a value", opt);
3355        *optarg = argv[1];
3356        return 2;
3357}
3358
3359static int stat_opt(struct diff_options *options, const char **av)
3360{
3361        const char *arg = av[0];
3362        char *end;
3363        int width = options->stat_width;
3364        int name_width = options->stat_name_width;
3365        int graph_width = options->stat_graph_width;
3366        int count = options->stat_count;
3367        int argcount = 1;
3368
3369        arg += strlen("--stat");
3370        end = (char *)arg;
3371
3372        switch (*arg) {
3373        case '-':
3374                if (!prefixcmp(arg, "-width")) {
3375                        arg += strlen("-width");
3376                        if (*arg == '=')
3377                                width = strtoul(arg + 1, &end, 10);
3378                        else if (!*arg && !av[1])
3379                                die("Option '--stat-width' requires a value");
3380                        else if (!*arg) {
3381                                width = strtoul(av[1], &end, 10);
3382                                argcount = 2;
3383                        }
3384                } else if (!prefixcmp(arg, "-name-width")) {
3385                        arg += strlen("-name-width");
3386                        if (*arg == '=')
3387                                name_width = strtoul(arg + 1, &end, 10);
3388                        else if (!*arg && !av[1])
3389                                die("Option '--stat-name-width' requires a value");
3390                        else if (!*arg) {
3391                                name_width = strtoul(av[1], &end, 10);
3392                                argcount = 2;
3393                        }
3394                } else if (!prefixcmp(arg, "-graph-width")) {
3395                        arg += strlen("-graph-width");
3396                        if (*arg == '=')
3397                                graph_width = strtoul(arg + 1, &end, 10);
3398                        else if (!*arg && !av[1])
3399                                die("Option '--stat-graph-width' requires a value");
3400                        else if (!*arg) {
3401                                graph_width = strtoul(av[1], &end, 10);
3402                                argcount = 2;
3403                        }
3404                } else if (!prefixcmp(arg, "-count")) {
3405                        arg += strlen("-count");
3406                        if (*arg == '=')
3407                                count = strtoul(arg + 1, &end, 10);
3408                        else if (!*arg && !av[1])
3409                                die("Option '--stat-count' requires a value");
3410                        else if (!*arg) {
3411                                count = strtoul(av[1], &end, 10);
3412                                argcount = 2;
3413                        }
3414                }
3415                break;
3416        case '=':
3417                width = strtoul(arg+1, &end, 10);
3418                if (*end == ',')
3419                        name_width = strtoul(end+1, &end, 10);
3420                if (*end == ',')
3421                        count = strtoul(end+1, &end, 10);
3422        }
3423
3424        /* Important! This checks all the error cases! */
3425        if (*end)
3426                return 0;
3427        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3428        options->stat_name_width = name_width;
3429        options->stat_graph_width = graph_width;
3430        options->stat_width = width;
3431        options->stat_count = count;
3432        return argcount;
3433}
3434
3435static int parse_dirstat_opt(struct diff_options *options, const char *params)
3436{
3437        struct strbuf errmsg = STRBUF_INIT;
3438        if (parse_dirstat_params(options, params, &errmsg))
3439                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3440                    errmsg.buf);
3441        strbuf_release(&errmsg);
3442        /*
3443         * The caller knows a dirstat-related option is given from the command
3444         * line; allow it to say "return this_function();"
3445         */
3446        options->output_format |= DIFF_FORMAT_DIRSTAT;
3447        return 1;
3448}
3449
3450int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3451{
3452        const char *arg = av[0];
3453        const char *optarg;
3454        int argcount;
3455
3456        /* Output format options */
3457        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3458                options->output_format |= DIFF_FORMAT_PATCH;
3459        else if (opt_arg(arg, 'U', "unified", &options->context))
3460                options->output_format |= DIFF_FORMAT_PATCH;
3461        else if (!strcmp(arg, "--raw"))
3462                options->output_format |= DIFF_FORMAT_RAW;
3463        else if (!strcmp(arg, "--patch-with-raw"))
3464                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3465        else if (!strcmp(arg, "--numstat"))
3466                options->output_format |= DIFF_FORMAT_NUMSTAT;
3467        else if (!strcmp(arg, "--shortstat"))
3468                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3469        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3470                return parse_dirstat_opt(options, "");
3471        else if (!prefixcmp(arg, "-X"))
3472                return parse_dirstat_opt(options, arg + 2);
3473        else if (!prefixcmp(arg, "--dirstat="))
3474                return parse_dirstat_opt(options, arg + 10);
3475        else if (!strcmp(arg, "--cumulative"))
3476                return parse_dirstat_opt(options, "cumulative");
3477        else if (!strcmp(arg, "--dirstat-by-file"))
3478                return parse_dirstat_opt(options, "files");
3479        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3480                parse_dirstat_opt(options, "files");
3481                return parse_dirstat_opt(options, arg + 18);
3482        }
3483        else if (!strcmp(arg, "--check"))
3484                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3485        else if (!strcmp(arg, "--summary"))
3486                options->output_format |= DIFF_FORMAT_SUMMARY;
3487        else if (!strcmp(arg, "--patch-with-stat"))
3488                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3489        else if (!strcmp(arg, "--name-only"))
3490                options->output_format |= DIFF_FORMAT_NAME;
3491        else if (!strcmp(arg, "--name-status"))
3492                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3493        else if (!strcmp(arg, "-s"))
3494                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3495        else if (!prefixcmp(arg, "--stat"))
3496                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3497                return stat_opt(options, av);
3498
3499        /* renames options */
3500        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3501                 !strcmp(arg, "--break-rewrites")) {
3502                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3503                        return error("invalid argument to -B: %s", arg+2);
3504        }
3505        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3506                 !strcmp(arg, "--find-renames")) {
3507                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3508                        return error("invalid argument to -M: %s", arg+2);
3509                options->detect_rename = DIFF_DETECT_RENAME;
3510        }
3511        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3512                options->irreversible_delete = 1;
3513        }
3514        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3515                 !strcmp(arg, "--find-copies")) {
3516                if (options->detect_rename == DIFF_DETECT_COPY)
3517                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3518                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3519                        return error("invalid argument to -C: %s", arg+2);
3520                options->detect_rename = DIFF_DETECT_COPY;
3521        }
3522        else if (!strcmp(arg, "--no-renames"))
3523                options->detect_rename = 0;
3524        else if (!strcmp(arg, "--rename-empty"))
3525                DIFF_OPT_SET(options, RENAME_EMPTY);
3526        else if (!strcmp(arg, "--no-rename-empty"))
3527                DIFF_OPT_CLR(options, RENAME_EMPTY);
3528        else if (!strcmp(arg, "--relative"))
3529                DIFF_OPT_SET(options, RELATIVE_NAME);
3530        else if (!prefixcmp(arg, "--relative=")) {
3531                DIFF_OPT_SET(options, RELATIVE_NAME);
3532                options->prefix = arg + 11;
3533        }
3534
3535        /* xdiff options */
3536        else if (!strcmp(arg, "--minimal"))
3537                DIFF_XDL_SET(options, NEED_MINIMAL);
3538        else if (!strcmp(arg, "--no-minimal"))
3539                DIFF_XDL_CLR(options, NEED_MINIMAL);
3540        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3541                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3542        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3543                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3544        else if (!strcmp(arg, "--ignore-space-at-eol"))
3545                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3546        else if (!strcmp(arg, "--patience"))
3547                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3548        else if (!strcmp(arg, "--histogram"))
3549                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3550
3551        /* flags options */
3552        else if (!strcmp(arg, "--binary")) {
3553                options->output_format |= DIFF_FORMAT_PATCH;
3554                DIFF_OPT_SET(options, BINARY);
3555        }
3556        else if (!strcmp(arg, "--full-index"))
3557                DIFF_OPT_SET(options, FULL_INDEX);
3558        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3559                DIFF_OPT_SET(options, TEXT);
3560        else if (!strcmp(arg, "-R"))
3561                DIFF_OPT_SET(options, REVERSE_DIFF);
3562        else if (!strcmp(arg, "--find-copies-harder"))
3563                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3564        else if (!strcmp(arg, "--follow"))
3565                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3566        else if (!strcmp(arg, "--color"))
3567                options->use_color = 1;
3568        else if (!prefixcmp(arg, "--color=")) {
3569                int value = git_config_colorbool(NULL, arg+8);
3570                if (value < 0)
3571                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3572                options->use_color = value;
3573        }
3574        else if (!strcmp(arg, "--no-color"))
3575                options->use_color = 0;
3576        else if (!strcmp(arg, "--color-words")) {
3577                options->use_color = 1;
3578                options->word_diff = DIFF_WORDS_COLOR;
3579        }
3580        else if (!prefixcmp(arg, "--color-words=")) {
3581                options->use_color = 1;
3582                options->word_diff = DIFF_WORDS_COLOR;
3583                options->word_regex = arg + 14;
3584        }
3585        else if (!strcmp(arg, "--word-diff")) {
3586                if (options->word_diff == DIFF_WORDS_NONE)
3587                        options->word_diff = DIFF_WORDS_PLAIN;
3588        }
3589        else if (!prefixcmp(arg, "--word-diff=")) {
3590                const char *type = arg + 12;
3591                if (!strcmp(type, "plain"))
3592                        options->word_diff = DIFF_WORDS_PLAIN;
3593                else if (!strcmp(type, "color")) {
3594                        options->use_color = 1;
3595                        options->word_diff = DIFF_WORDS_COLOR;
3596                }
3597                else if (!strcmp(type, "porcelain"))
3598                        options->word_diff = DIFF_WORDS_PORCELAIN;
3599                else if (!strcmp(type, "none"))
3600                        options->word_diff = DIFF_WORDS_NONE;
3601                else
3602                        die("bad --word-diff argument: %s", type);
3603        }
3604        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3605                if (options->word_diff == DIFF_WORDS_NONE)
3606                        options->word_diff = DIFF_WORDS_PLAIN;
3607                options->word_regex = optarg;
3608                return argcount;
3609        }
3610        else if (!strcmp(arg, "--exit-code"))
3611                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3612        else if (!strcmp(arg, "--quiet"))
3613                DIFF_OPT_SET(options, QUICK);
3614        else if (!strcmp(arg, "--ext-diff"))
3615                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3616        else if (!strcmp(arg, "--no-ext-diff"))
3617                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3618        else if (!strcmp(arg, "--textconv"))
3619                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3620        else if (!strcmp(arg, "--no-textconv"))
3621                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3622        else if (!strcmp(arg, "--ignore-submodules")) {
3623                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3624                handle_ignore_submodules_arg(options, "all");
3625        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3626                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3627                handle_ignore_submodules_arg(options, arg + 20);
3628        } else if (!strcmp(arg, "--submodule"))
3629                DIFF_OPT_SET(options, SUBMODULE_LOG);
3630        else if (!prefixcmp(arg, "--submodule=")) {
3631                if (!strcmp(arg + 12, "log"))
3632                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3633        }
3634
3635        /* misc options */
3636        else if (!strcmp(arg, "-z"))
3637                options->line_termination = 0;
3638        else if ((argcount = short_opt('l', av, &optarg))) {
3639                options->rename_limit = strtoul(optarg, NULL, 10);
3640                return argcount;
3641        }
3642        else if ((argcount = short_opt('S', av, &optarg))) {
3643                options->pickaxe = optarg;
3644                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3645                return argcount;
3646        } else if ((argcount = short_opt('G', av, &optarg))) {
3647                options->pickaxe = optarg;
3648                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3649                return argcount;
3650        }
3651        else if (!strcmp(arg, "--pickaxe-all"))
3652                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3653        else if (!strcmp(arg, "--pickaxe-regex"))
3654                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3655        else if ((argcount = short_opt('O', av, &optarg))) {
3656                options->orderfile = optarg;
3657                return argcount;
3658        }
3659        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3660                options->filter = optarg;
3661                return argcount;
3662        }
3663        else if (!strcmp(arg, "--abbrev"))
3664                options->abbrev = DEFAULT_ABBREV;
3665        else if (!prefixcmp(arg, "--abbrev=")) {
3666                options->abbrev = strtoul(arg + 9, NULL, 10);
3667                if (options->abbrev < MINIMUM_ABBREV)
3668                        options->abbrev = MINIMUM_ABBREV;
3669                else if (40 < options->abbrev)
3670                        options->abbrev = 40;
3671        }
3672        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3673                options->a_prefix = optarg;
3674                return argcount;
3675        }
3676        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3677                options->b_prefix = optarg;
3678                return argcount;
3679        }
3680        else if (!strcmp(arg, "--no-prefix"))
3681                options->a_prefix = options->b_prefix = "";
3682        else if (opt_arg(arg, '\0', "inter-hunk-context",
3683                         &options->interhunkcontext))
3684                ;
3685        else if (!strcmp(arg, "-W"))
3686                DIFF_OPT_SET(options, FUNCCONTEXT);
3687        else if (!strcmp(arg, "--function-context"))
3688                DIFF_OPT_SET(options, FUNCCONTEXT);
3689        else if (!strcmp(arg, "--no-function-context"))
3690                DIFF_OPT_CLR(options, FUNCCONTEXT);
3691        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3692                options->file = fopen(optarg, "w");
3693                if (!options->file)
3694                        die_errno("Could not open '%s'", optarg);
3695                options->close_file = 1;
3696                return argcount;
3697        } else
3698                return 0;
3699        return 1;
3700}
3701
3702int parse_rename_score(const char **cp_p)
3703{
3704        unsigned long num, scale;
3705        int ch, dot;
3706        const char *cp = *cp_p;
3707
3708        num = 0;
3709        scale = 1;
3710        dot = 0;
3711        for (;;) {
3712                ch = *cp;
3713                if ( !dot && ch == '.' ) {
3714                        scale = 1;
3715                        dot = 1;
3716                } else if ( ch == '%' ) {
3717                        scale = dot ? scale*100 : 100;
3718                        cp++;   /* % is always at the end */
3719                        break;
3720                } else if ( ch >= '0' && ch <= '9' ) {
3721                        if ( scale < 100000 ) {
3722                                scale *= 10;
3723                                num = (num*10) + (ch-'0');
3724                        }
3725                } else {
3726                        break;
3727                }
3728                cp++;
3729        }
3730        *cp_p = cp;
3731
3732        /* user says num divided by scale and we say internally that
3733         * is MAX_SCORE * num / scale.
3734         */
3735        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3736}
3737
3738static int diff_scoreopt_parse(const char *opt)
3739{
3740        int opt1, opt2, cmd;
3741
3742        if (*opt++ != '-')
3743                return -1;
3744        cmd = *opt++;
3745        if (cmd == '-') {
3746                /* convert the long-form arguments into short-form versions */
3747                if (!prefixcmp(opt, "break-rewrites")) {
3748                        opt += strlen("break-rewrites");
3749                        if (*opt == 0 || *opt++ == '=')
3750                                cmd = 'B';
3751                } else if (!prefixcmp(opt, "find-copies")) {
3752                        opt += strlen("find-copies");
3753                        if (*opt == 0 || *opt++ == '=')
3754                                cmd = 'C';
3755                } else if (!prefixcmp(opt, "find-renames")) {
3756                        opt += strlen("find-renames");
3757                        if (*opt == 0 || *opt++ == '=')
3758                                cmd = 'M';
3759                }
3760        }
3761        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3762                return -1; /* that is not a -M, -C nor -B option */
3763
3764        opt1 = parse_rename_score(&opt);
3765        if (cmd != 'B')
3766                opt2 = 0;
3767        else {
3768                if (*opt == 0)
3769                        opt2 = 0;
3770                else if (*opt != '/')
3771                        return -1; /* we expect -B80/99 or -B80 */
3772                else {
3773                        opt++;
3774                        opt2 = parse_rename_score(&opt);
3775                }
3776        }
3777        if (*opt != 0)
3778                return -1;
3779        return opt1 | (opt2 << 16);
3780}
3781
3782struct diff_queue_struct diff_queued_diff;
3783
3784void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3785{
3786        if (queue->alloc <= queue->nr) {
3787                queue->alloc = alloc_nr(queue->alloc);
3788                queue->queue = xrealloc(queue->queue,
3789                                        sizeof(dp) * queue->alloc);
3790        }
3791        queue->queue[queue->nr++] = dp;
3792}
3793
3794struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3795                                 struct diff_filespec *one,
3796                                 struct diff_filespec *two)
3797{
3798        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3799        dp->one = one;
3800        dp->two = two;
3801        if (queue)
3802                diff_q(queue, dp);
3803        return dp;
3804}
3805
3806void diff_free_filepair(struct diff_filepair *p)
3807{
3808        free_filespec(p->one);
3809        free_filespec(p->two);
3810        free(p);
3811}
3812
3813/* This is different from find_unique_abbrev() in that
3814 * it stuffs the result with dots for alignment.
3815 */
3816const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3817{
3818        int abblen;
3819        const char *abbrev;
3820        if (len == 40)
3821                return sha1_to_hex(sha1);
3822
3823        abbrev = find_unique_abbrev(sha1, len);
3824        abblen = strlen(abbrev);
3825        if (abblen < 37) {
3826                static char hex[41];
3827                if (len < abblen && abblen <= len + 2)
3828                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3829                else
3830                        sprintf(hex, "%s...", abbrev);
3831                return hex;
3832        }
3833        return sha1_to_hex(sha1);
3834}
3835
3836static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3837{
3838        int line_termination = opt->line_termination;
3839        int inter_name_termination = line_termination ? '\t' : '\0';
3840        if (opt->output_prefix) {
3841                struct strbuf *msg = NULL;
3842                msg = opt->output_prefix(opt, opt->output_prefix_data);
3843                fprintf(opt->file, "%s", msg->buf);
3844        }
3845
3846        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3847                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3848                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3849                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3850        }
3851        if (p->score) {
3852                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3853                        inter_name_termination);
3854        } else {
3855                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3856        }
3857
3858        if (p->status == DIFF_STATUS_COPIED ||
3859            p->status == DIFF_STATUS_RENAMED) {
3860                const char *name_a, *name_b;
3861                name_a = p->one->path;
3862                name_b = p->two->path;
3863                strip_prefix(opt->prefix_length, &name_a, &name_b);
3864                write_name_quoted(name_a, opt->file, inter_name_termination);
3865                write_name_quoted(name_b, opt->file, line_termination);
3866        } else {
3867                const char *name_a, *name_b;
3868                name_a = p->one->mode ? p->one->path : p->two->path;
3869                name_b = NULL;
3870                strip_prefix(opt->prefix_length, &name_a, &name_b);
3871                write_name_quoted(name_a, opt->file, line_termination);
3872        }
3873}
3874
3875int diff_unmodified_pair(struct diff_filepair *p)
3876{
3877        /* This function is written stricter than necessary to support
3878         * the currently implemented transformers, but the idea is to
3879         * let transformers to produce diff_filepairs any way they want,
3880         * and filter and clean them up here before producing the output.
3881         */
3882        struct diff_filespec *one = p->one, *two = p->two;
3883
3884        if (DIFF_PAIR_UNMERGED(p))
3885                return 0; /* unmerged is interesting */
3886
3887        /* deletion, addition, mode or type change
3888         * and rename are all interesting.
3889         */
3890        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3891            DIFF_PAIR_MODE_CHANGED(p) ||
3892            strcmp(one->path, two->path))
3893                return 0;
3894
3895        /* both are valid and point at the same path.  that is, we are
3896         * dealing with a change.
3897         */
3898        if (one->sha1_valid && two->sha1_valid &&
3899            !hashcmp(one->sha1, two->sha1) &&
3900            !one->dirty_submodule && !two->dirty_submodule)
3901                return 1; /* no change */
3902        if (!one->sha1_valid && !two->sha1_valid)
3903                return 1; /* both look at the same file on the filesystem. */
3904        return 0;
3905}
3906
3907static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3908{
3909        if (diff_unmodified_pair(p))
3910                return;
3911
3912        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3913            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3914                return; /* no tree diffs in patch format */
3915
3916        run_diff(p, o);
3917}
3918
3919static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3920                            struct diffstat_t *diffstat)
3921{
3922        if (diff_unmodified_pair(p))
3923                return;
3924
3925        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3926            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3927                return; /* no useful stat for tree diffs */
3928
3929        run_diffstat(p, o, diffstat);
3930}
3931
3932static void diff_flush_checkdiff(struct diff_filepair *p,
3933                struct diff_options *o)
3934{
3935        if (diff_unmodified_pair(p))
3936                return;
3937
3938        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3939            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3940                return; /* nothing to check in tree diffs */
3941
3942        run_checkdiff(p, o);
3943}
3944
3945int diff_queue_is_empty(void)
3946{
3947        struct diff_queue_struct *q = &diff_queued_diff;
3948        int i;
3949        for (i = 0; i < q->nr; i++)
3950                if (!diff_unmodified_pair(q->queue[i]))
3951                        return 0;
3952        return 1;
3953}
3954
3955#if DIFF_DEBUG
3956void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3957{
3958        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3959                x, one ? one : "",
3960                s->path,
3961                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3962                s->mode,
3963                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3964        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3965                x, one ? one : "",
3966                s->size, s->xfrm_flags);
3967}
3968
3969void diff_debug_filepair(const struct diff_filepair *p, int i)
3970{
3971        diff_debug_filespec(p->one, i, "one");
3972        diff_debug_filespec(p->two, i, "two");
3973        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3974                p->score, p->status ? p->status : '?',
3975                p->one->rename_used, p->broken_pair);
3976}
3977
3978void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3979{
3980        int i;
3981        if (msg)
3982                fprintf(stderr, "%s\n", msg);
3983        fprintf(stderr, "q->nr = %d\n", q->nr);
3984        for (i = 0; i < q->nr; i++) {
3985                struct diff_filepair *p = q->queue[i];
3986                diff_debug_filepair(p, i);
3987        }
3988}
3989#endif
3990
3991static void diff_resolve_rename_copy(void)
3992{
3993        int i;
3994        struct diff_filepair *p;
3995        struct diff_queue_struct *q = &diff_queued_diff;
3996
3997        diff_debug_queue("resolve-rename-copy", q);
3998
3999        for (i = 0; i < q->nr; i++) {
4000                p = q->queue[i];
4001                p->status = 0; /* undecided */
4002                if (DIFF_PAIR_UNMERGED(p))
4003                        p->status = DIFF_STATUS_UNMERGED;
4004                else if (!DIFF_FILE_VALID(p->one))
4005                        p->status = DIFF_STATUS_ADDED;
4006                else if (!DIFF_FILE_VALID(p->two))
4007                        p->status = DIFF_STATUS_DELETED;
4008                else if (DIFF_PAIR_TYPE_CHANGED(p))
4009                        p->status = DIFF_STATUS_TYPE_CHANGED;
4010
4011                /* from this point on, we are dealing with a pair
4012                 * whose both sides are valid and of the same type, i.e.
4013                 * either in-place edit or rename/copy edit.
4014                 */
4015                else if (DIFF_PAIR_RENAME(p)) {
4016                        /*
4017                         * A rename might have re-connected a broken
4018                         * pair up, causing the pathnames to be the
4019                         * same again. If so, that's not a rename at
4020                         * all, just a modification..
4021                         *
4022                         * Otherwise, see if this source was used for
4023                         * multiple renames, in which case we decrement
4024                         * the count, and call it a copy.
4025                         */
4026                        if (!strcmp(p->one->path, p->two->path))
4027                                p->status = DIFF_STATUS_MODIFIED;
4028                        else if (--p->one->rename_used > 0)
4029                                p->status = DIFF_STATUS_COPIED;
4030                        else
4031                                p->status = DIFF_STATUS_RENAMED;
4032                }
4033                else if (hashcmp(p->one->sha1, p->two->sha1) ||
4034                         p->one->mode != p->two->mode ||
4035                         p->one->dirty_submodule ||
4036                         p->two->dirty_submodule ||
4037                         is_null_sha1(p->one->sha1))
4038                        p->status = DIFF_STATUS_MODIFIED;
4039                else {
4040                        /* This is a "no-change" entry and should not
4041                         * happen anymore, but prepare for broken callers.
4042                         */
4043                        error("feeding unmodified %s to diffcore",
4044                              p->one->path);
4045                        p->status = DIFF_STATUS_UNKNOWN;
4046                }
4047        }
4048        diff_debug_queue("resolve-rename-copy done", q);
4049}
4050
4051static int check_pair_status(struct diff_filepair *p)
4052{
4053        switch (p->status) {
4054        case DIFF_STATUS_UNKNOWN:
4055                return 0;
4056        case 0:
4057                die("internal error in diff-resolve-rename-copy");
4058        default:
4059                return 1;
4060        }
4061}
4062
4063static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4064{
4065        int fmt = opt->output_format;
4066
4067        if (fmt & DIFF_FORMAT_CHECKDIFF)
4068                diff_flush_checkdiff(p, opt);
4069        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4070                diff_flush_raw(p, opt);
4071        else if (fmt & DIFF_FORMAT_NAME) {
4072                const char *name_a, *name_b;
4073                name_a = p->two->path;
4074                name_b = NULL;
4075                strip_prefix(opt->prefix_length, &name_a, &name_b);
4076                write_name_quoted(name_a, opt->file, opt->line_termination);
4077        }
4078}
4079
4080static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4081{
4082        if (fs->mode)
4083                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4084        else
4085                fprintf(file, " %s ", newdelete);
4086        write_name_quoted(fs->path, file, '\n');
4087}
4088
4089
4090static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4091                const char *line_prefix)
4092{
4093        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4094                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4095                        p->two->mode, show_name ? ' ' : '\n');
4096                if (show_name) {
4097                        write_name_quoted(p->two->path, file, '\n');
4098                }
4099        }
4100}
4101
4102static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4103                        const char *line_prefix)
4104{
4105        char *names = pprint_rename(p->one->path, p->two->path);
4106
4107        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4108        free(names);
4109        show_mode_change(file, p, 0, line_prefix);
4110}
4111
4112static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4113{
4114        FILE *file = opt->file;
4115        char *line_prefix = "";
4116
4117        if (opt->output_prefix) {
4118                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
4119                line_prefix = buf->buf;
4120        }
4121
4122        switch(p->status) {
4123        case DIFF_STATUS_DELETED:
4124                fputs(line_prefix, file);
4125                show_file_mode_name(file, "delete", p->one);
4126                break;
4127        case DIFF_STATUS_ADDED:
4128                fputs(line_prefix, file);
4129                show_file_mode_name(file, "create", p->two);
4130                break;
4131        case DIFF_STATUS_COPIED:
4132                fputs(line_prefix, file);
4133                show_rename_copy(file, "copy", p, line_prefix);
4134                break;
4135        case DIFF_STATUS_RENAMED:
4136                fputs(line_prefix, file);
4137                show_rename_copy(file, "rename", p, line_prefix);
4138                break;
4139        default:
4140                if (p->score) {
4141                        fprintf(file, "%s rewrite ", line_prefix);
4142                        write_name_quoted(p->two->path, file, ' ');
4143                        fprintf(file, "(%d%%)\n", similarity_index(p));
4144                }
4145                show_mode_change(file, p, !p->score, line_prefix);
4146                break;
4147        }
4148}
4149
4150struct patch_id_t {
4151        git_SHA_CTX *ctx;
4152        int patchlen;
4153};
4154
4155static int remove_space(char *line, int len)
4156{
4157        int i;
4158        char *dst = line;
4159        unsigned char c;
4160
4161        for (i = 0; i < len; i++)
4162                if (!isspace((c = line[i])))
4163                        *dst++ = c;
4164
4165        return dst - line;
4166}
4167
4168static void patch_id_consume(void *priv, char *line, unsigned long len)
4169{
4170        struct patch_id_t *data = priv;
4171        int new_len;
4172
4173        /* Ignore line numbers when computing the SHA1 of the patch */
4174        if (!prefixcmp(line, "@@ -"))
4175                return;
4176
4177        new_len = remove_space(line, len);
4178
4179        git_SHA1_Update(data->ctx, line, new_len);
4180        data->patchlen += new_len;
4181}
4182
4183/* returns 0 upon success, and writes result into sha1 */
4184static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4185{
4186        struct diff_queue_struct *q = &diff_queued_diff;
4187        int i;
4188        git_SHA_CTX ctx;
4189        struct patch_id_t data;
4190        char buffer[PATH_MAX * 4 + 20];
4191
4192        git_SHA1_Init(&ctx);
4193        memset(&data, 0, sizeof(struct patch_id_t));
4194        data.ctx = &ctx;
4195
4196        for (i = 0; i < q->nr; i++) {
4197                xpparam_t xpp;
4198                xdemitconf_t xecfg;
4199                mmfile_t mf1, mf2;
4200                struct diff_filepair *p = q->queue[i];
4201                int len1, len2;
4202
4203                memset(&xpp, 0, sizeof(xpp));
4204                memset(&xecfg, 0, sizeof(xecfg));
4205                if (p->status == 0)
4206                        return error("internal diff status error");
4207                if (p->status == DIFF_STATUS_UNKNOWN)
4208                        continue;
4209                if (diff_unmodified_pair(p))
4210                        continue;
4211                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4212                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4213                        continue;
4214                if (DIFF_PAIR_UNMERGED(p))
4215                        continue;
4216
4217                diff_fill_sha1_info(p->one);
4218                diff_fill_sha1_info(p->two);
4219                if (fill_mmfile(&mf1, p->one) < 0 ||
4220                                fill_mmfile(&mf2, p->two) < 0)
4221                        return error("unable to read files to diff");
4222
4223                len1 = remove_space(p->one->path, strlen(p->one->path));
4224                len2 = remove_space(p->two->path, strlen(p->two->path));
4225                if (p->one->mode == 0)
4226                        len1 = snprintf(buffer, sizeof(buffer),
4227                                        "diff--gita/%.*sb/%.*s"
4228                                        "newfilemode%06o"
4229                                        "---/dev/null"
4230                                        "+++b/%.*s",
4231                                        len1, p->one->path,
4232                                        len2, p->two->path,
4233                                        p->two->mode,
4234                                        len2, p->two->path);
4235                else if (p->two->mode == 0)
4236                        len1 = snprintf(buffer, sizeof(buffer),
4237                                        "diff--gita/%.*sb/%.*s"
4238                                        "deletedfilemode%06o"
4239                                        "---a/%.*s"
4240                                        "+++/dev/null",
4241                                        len1, p->one->path,
4242                                        len2, p->two->path,
4243                                        p->one->mode,
4244                                        len1, p->one->path);
4245                else
4246                        len1 = snprintf(buffer, sizeof(buffer),
4247                                        "diff--gita/%.*sb/%.*s"
4248                                        "---a/%.*s"
4249                                        "+++b/%.*s",
4250                                        len1, p->one->path,
4251                                        len2, p->two->path,
4252                                        len1, p->one->path,
4253                                        len2, p->two->path);
4254                git_SHA1_Update(&ctx, buffer, len1);
4255
4256                if (diff_filespec_is_binary(p->one) ||
4257                    diff_filespec_is_binary(p->two)) {
4258                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4259                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4260                        continue;
4261                }
4262
4263                xpp.flags = 0;
4264                xecfg.ctxlen = 3;
4265                xecfg.flags = 0;
4266                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4267                              &xpp, &xecfg);
4268        }
4269
4270        git_SHA1_Final(sha1, &ctx);
4271        return 0;
4272}
4273
4274int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4275{
4276        struct diff_queue_struct *q = &diff_queued_diff;
4277        int i;
4278        int result = diff_get_patch_id(options, sha1);
4279
4280        for (i = 0; i < q->nr; i++)
4281                diff_free_filepair(q->queue[i]);
4282
4283        free(q->queue);
4284        DIFF_QUEUE_CLEAR(q);
4285
4286        return result;
4287}
4288
4289static int is_summary_empty(const struct diff_queue_struct *q)
4290{
4291        int i;
4292
4293        for (i = 0; i < q->nr; i++) {
4294                const struct diff_filepair *p = q->queue[i];
4295
4296                switch (p->status) {
4297                case DIFF_STATUS_DELETED:
4298                case DIFF_STATUS_ADDED:
4299                case DIFF_STATUS_COPIED:
4300                case DIFF_STATUS_RENAMED:
4301                        return 0;
4302                default:
4303                        if (p->score)
4304                                return 0;
4305                        if (p->one->mode && p->two->mode &&
4306                            p->one->mode != p->two->mode)
4307                                return 0;
4308                        break;
4309                }
4310        }
4311        return 1;
4312}
4313
4314static const char rename_limit_warning[] =
4315"inexact rename detection was skipped due to too many files.";
4316
4317static const char degrade_cc_to_c_warning[] =
4318"only found copies from modified paths due to too many files.";
4319
4320static const char rename_limit_advice[] =
4321"you may want to set your %s variable to at least "
4322"%d and retry the command.";
4323
4324void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4325{
4326        if (degraded_cc)
4327                warning(degrade_cc_to_c_warning);
4328        else if (needed)
4329                warning(rename_limit_warning);
4330        else
4331                return;
4332        if (0 < needed && needed < 32767)
4333                warning(rename_limit_advice, varname, needed);
4334}
4335
4336void diff_flush(struct diff_options *options)
4337{
4338        struct diff_queue_struct *q = &diff_queued_diff;
4339        int i, output_format = options->output_format;
4340        int separator = 0;
4341        int dirstat_by_line = 0;
4342
4343        /*
4344         * Order: raw, stat, summary, patch
4345         * or:    name/name-status/checkdiff (other bits clear)
4346         */
4347        if (!q->nr)
4348                goto free_queue;
4349
4350        if (output_format & (DIFF_FORMAT_RAW |
4351                             DIFF_FORMAT_NAME |
4352                             DIFF_FORMAT_NAME_STATUS |
4353                             DIFF_FORMAT_CHECKDIFF)) {
4354                for (i = 0; i < q->nr; i++) {
4355                        struct diff_filepair *p = q->queue[i];
4356                        if (check_pair_status(p))
4357                                flush_one_pair(p, options);
4358                }
4359                separator++;
4360        }
4361
4362        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4363                dirstat_by_line = 1;
4364
4365        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4366            dirstat_by_line) {
4367                struct diffstat_t diffstat;
4368
4369                memset(&diffstat, 0, sizeof(struct diffstat_t));
4370                for (i = 0; i < q->nr; i++) {
4371                        struct diff_filepair *p = q->queue[i];
4372                        if (check_pair_status(p))
4373                                diff_flush_stat(p, options, &diffstat);
4374                }
4375                if (output_format & DIFF_FORMAT_NUMSTAT)
4376                        show_numstat(&diffstat, options);
4377                if (output_format & DIFF_FORMAT_DIFFSTAT)
4378                        show_stats(&diffstat, options);
4379                if (output_format & DIFF_FORMAT_SHORTSTAT)
4380                        show_shortstats(&diffstat, options);
4381                if (output_format & DIFF_FORMAT_DIRSTAT)
4382                        show_dirstat_by_line(&diffstat, options);
4383                free_diffstat_info(&diffstat);
4384                separator++;
4385        }
4386        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4387                show_dirstat(options);
4388
4389        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4390                for (i = 0; i < q->nr; i++) {
4391                        diff_summary(options, q->queue[i]);
4392                }
4393                separator++;
4394        }
4395
4396        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4397            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4398            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4399                /*
4400                 * run diff_flush_patch for the exit status. setting
4401                 * options->file to /dev/null should be safe, becaue we
4402                 * aren't supposed to produce any output anyway.
4403                 */
4404                if (options->close_file)
4405                        fclose(options->file);
4406                options->file = fopen("/dev/null", "w");
4407                if (!options->file)
4408                        die_errno("Could not open /dev/null");
4409                options->close_file = 1;
4410                for (i = 0; i < q->nr; i++) {
4411                        struct diff_filepair *p = q->queue[i];
4412                        if (check_pair_status(p))
4413                                diff_flush_patch(p, options);
4414                        if (options->found_changes)
4415                                break;
4416                }
4417        }
4418
4419        if (output_format & DIFF_FORMAT_PATCH) {
4420                if (separator) {
4421                        if (options->output_prefix) {
4422                                struct strbuf *msg = NULL;
4423                                msg = options->output_prefix(options,
4424                                        options->output_prefix_data);
4425                                fwrite(msg->buf, msg->len, 1, stdout);
4426                        }
4427                        putc(options->line_termination, options->file);
4428                        if (options->stat_sep) {
4429                                /* attach patch instead of inline */
4430                                fputs(options->stat_sep, options->file);
4431                        }
4432                }
4433
4434                for (i = 0; i < q->nr; i++) {
4435                        struct diff_filepair *p = q->queue[i];
4436                        if (check_pair_status(p))
4437                                diff_flush_patch(p, options);
4438                }
4439        }
4440
4441        if (output_format & DIFF_FORMAT_CALLBACK)
4442                options->format_callback(q, options, options->format_callback_data);
4443
4444        for (i = 0; i < q->nr; i++)
4445                diff_free_filepair(q->queue[i]);
4446free_queue:
4447        free(q->queue);
4448        DIFF_QUEUE_CLEAR(q);
4449        if (options->close_file)
4450                fclose(options->file);
4451
4452        /*
4453         * Report the content-level differences with HAS_CHANGES;
4454         * diff_addremove/diff_change does not set the bit when
4455         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4456         */
4457        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4458                if (options->found_changes)
4459                        DIFF_OPT_SET(options, HAS_CHANGES);
4460                else
4461                        DIFF_OPT_CLR(options, HAS_CHANGES);
4462        }
4463}
4464
4465static void diffcore_apply_filter(const char *filter)
4466{
4467        int i;
4468        struct diff_queue_struct *q = &diff_queued_diff;
4469        struct diff_queue_struct outq;
4470        DIFF_QUEUE_CLEAR(&outq);
4471
4472        if (!filter)
4473                return;
4474
4475        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4476                int found;
4477                for (i = found = 0; !found && i < q->nr; i++) {
4478                        struct diff_filepair *p = q->queue[i];
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                                found++;
4487                }
4488                if (found)
4489                        return;
4490
4491                /* otherwise we will clear the whole queue
4492                 * by copying the empty outq at the end of this
4493                 * function, but first clear the current entries
4494                 * in the queue.
4495                 */
4496                for (i = 0; i < q->nr; i++)
4497                        diff_free_filepair(q->queue[i]);
4498        }
4499        else {
4500                /* Only the matching ones */
4501                for (i = 0; i < q->nr; i++) {
4502                        struct diff_filepair *p = q->queue[i];
4503
4504                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4505                             ((p->score &&
4506                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4507                              (!p->score &&
4508                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4509                            ((p->status != DIFF_STATUS_MODIFIED) &&
4510                             strchr(filter, p->status)))
4511                                diff_q(&outq, p);
4512                        else
4513                                diff_free_filepair(p);
4514                }
4515        }
4516        free(q->queue);
4517        *q = outq;
4518}
4519
4520/* Check whether two filespecs with the same mode and size are identical */
4521static int diff_filespec_is_identical(struct diff_filespec *one,
4522                                      struct diff_filespec *two)
4523{
4524        if (S_ISGITLINK(one->mode))
4525                return 0;
4526        if (diff_populate_filespec(one, 0))
4527                return 0;
4528        if (diff_populate_filespec(two, 0))
4529                return 0;
4530        return !memcmp(one->data, two->data, one->size);
4531}
4532
4533static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4534{
4535        int i;
4536        struct diff_queue_struct *q = &diff_queued_diff;
4537        struct diff_queue_struct outq;
4538        DIFF_QUEUE_CLEAR(&outq);
4539
4540        for (i = 0; i < q->nr; i++) {
4541                struct diff_filepair *p = q->queue[i];
4542
4543                /*
4544                 * 1. Entries that come from stat info dirtiness
4545                 *    always have both sides (iow, not create/delete),
4546                 *    one side of the object name is unknown, with
4547                 *    the same mode and size.  Keep the ones that
4548                 *    do not match these criteria.  They have real
4549                 *    differences.
4550                 *
4551                 * 2. At this point, the file is known to be modified,
4552                 *    with the same mode and size, and the object
4553                 *    name of one side is unknown.  Need to inspect
4554                 *    the identical contents.
4555                 */
4556                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4557                    !DIFF_FILE_VALID(p->two) ||
4558                    (p->one->sha1_valid && p->two->sha1_valid) ||
4559                    (p->one->mode != p->two->mode) ||
4560                    diff_populate_filespec(p->one, 1) ||
4561                    diff_populate_filespec(p->two, 1) ||
4562                    (p->one->size != p->two->size) ||
4563                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4564                        diff_q(&outq, p);
4565                else {
4566                        /*
4567                         * The caller can subtract 1 from skip_stat_unmatch
4568                         * to determine how many paths were dirty only
4569                         * due to stat info mismatch.
4570                         */
4571                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4572                                diffopt->skip_stat_unmatch++;
4573                        diff_free_filepair(p);
4574                }
4575        }
4576        free(q->queue);
4577        *q = outq;
4578}
4579
4580static int diffnamecmp(const void *a_, const void *b_)
4581{
4582        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4583        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4584        const char *name_a, *name_b;
4585
4586        name_a = a->one ? a->one->path : a->two->path;
4587        name_b = b->one ? b->one->path : b->two->path;
4588        return strcmp(name_a, name_b);
4589}
4590
4591void diffcore_fix_diff_index(struct diff_options *options)
4592{
4593        struct diff_queue_struct *q = &diff_queued_diff;
4594        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4595}
4596
4597void diffcore_std(struct diff_options *options)
4598{
4599        if (options->skip_stat_unmatch)
4600                diffcore_skip_stat_unmatch(options);
4601        if (!options->found_follow) {
4602                /* See try_to_follow_renames() in tree-diff.c */
4603                if (options->break_opt != -1)
4604                        diffcore_break(options->break_opt);
4605                if (options->detect_rename)
4606                        diffcore_rename(options);
4607                if (options->break_opt != -1)
4608                        diffcore_merge_broken();
4609        }
4610        if (options->pickaxe)
4611                diffcore_pickaxe(options);
4612        if (options->orderfile)
4613                diffcore_order(options->orderfile);
4614        if (!options->found_follow)
4615                /* See try_to_follow_renames() in tree-diff.c */
4616                diff_resolve_rename_copy();
4617        diffcore_apply_filter(options->filter);
4618
4619        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4620                DIFF_OPT_SET(options, HAS_CHANGES);
4621        else
4622                DIFF_OPT_CLR(options, HAS_CHANGES);
4623
4624        options->found_follow = 0;
4625}
4626
4627int diff_result_code(struct diff_options *opt, int status)
4628{
4629        int result = 0;
4630
4631        diff_warn_rename_limit("diff.renamelimit",
4632                               opt->needed_rename_limit,
4633                               opt->degraded_cc_to_c);
4634        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4635            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4636                return status;
4637        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4638            DIFF_OPT_TST(opt, HAS_CHANGES))
4639                result |= 01;
4640        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4641            DIFF_OPT_TST(opt, CHECK_FAILED))
4642                result |= 02;
4643        return result;
4644}
4645
4646int diff_can_quit_early(struct diff_options *opt)
4647{
4648        return (DIFF_OPT_TST(opt, QUICK) &&
4649                !opt->filter &&
4650                DIFF_OPT_TST(opt, HAS_CHANGES));
4651}
4652
4653/*
4654 * Shall changes to this submodule be ignored?
4655 *
4656 * Submodule changes can be configured to be ignored separately for each path,
4657 * but that configuration can be overridden from the command line.
4658 */
4659static int is_submodule_ignored(const char *path, struct diff_options *options)
4660{
4661        int ignored = 0;
4662        unsigned orig_flags = options->flags;
4663        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4664                set_diffopt_flags_from_submodule_config(options, path);
4665        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4666                ignored = 1;
4667        options->flags = orig_flags;
4668        return ignored;
4669}
4670
4671void diff_addremove(struct diff_options *options,
4672                    int addremove, unsigned mode,
4673                    const unsigned char *sha1,
4674                    const char *concatpath, unsigned dirty_submodule)
4675{
4676        struct diff_filespec *one, *two;
4677
4678        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4679                return;
4680
4681        /* This may look odd, but it is a preparation for
4682         * feeding "there are unchanged files which should
4683         * not produce diffs, but when you are doing copy
4684         * detection you would need them, so here they are"
4685         * entries to the diff-core.  They will be prefixed
4686         * with something like '=' or '*' (I haven't decided
4687         * which but should not make any difference).
4688         * Feeding the same new and old to diff_change()
4689         * also has the same effect.
4690         * Before the final output happens, they are pruned after
4691         * merged into rename/copy pairs as appropriate.
4692         */
4693        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4694                addremove = (addremove == '+' ? '-' :
4695                             addremove == '-' ? '+' : addremove);
4696
4697        if (options->prefix &&
4698            strncmp(concatpath, options->prefix, options->prefix_length))
4699                return;
4700
4701        one = alloc_filespec(concatpath);
4702        two = alloc_filespec(concatpath);
4703
4704        if (addremove != '+')
4705                fill_filespec(one, sha1, mode);
4706        if (addremove != '-') {
4707                fill_filespec(two, sha1, mode);
4708                two->dirty_submodule = dirty_submodule;
4709        }
4710
4711        diff_queue(&diff_queued_diff, one, two);
4712        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4713                DIFF_OPT_SET(options, HAS_CHANGES);
4714}
4715
4716void diff_change(struct diff_options *options,
4717                 unsigned old_mode, unsigned new_mode,
4718                 const unsigned char *old_sha1,
4719                 const unsigned char *new_sha1,
4720                 const char *concatpath,
4721                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4722{
4723        struct diff_filespec *one, *two;
4724
4725        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4726            is_submodule_ignored(concatpath, options))
4727                return;
4728
4729        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4730                unsigned tmp;
4731                const unsigned char *tmp_c;
4732                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4733                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4734                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4735                        new_dirty_submodule = tmp;
4736        }
4737
4738        if (options->prefix &&
4739            strncmp(concatpath, options->prefix, options->prefix_length))
4740                return;
4741
4742        one = alloc_filespec(concatpath);
4743        two = alloc_filespec(concatpath);
4744        fill_filespec(one, old_sha1, old_mode);
4745        fill_filespec(two, new_sha1, new_mode);
4746        one->dirty_submodule = old_dirty_submodule;
4747        two->dirty_submodule = new_dirty_submodule;
4748
4749        diff_queue(&diff_queued_diff, one, two);
4750        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4751                DIFF_OPT_SET(options, HAS_CHANGES);
4752}
4753
4754struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4755{
4756        struct diff_filepair *pair;
4757        struct diff_filespec *one, *two;
4758
4759        if (options->prefix &&
4760            strncmp(path, options->prefix, options->prefix_length))
4761                return NULL;
4762
4763        one = alloc_filespec(path);
4764        two = alloc_filespec(path);
4765        pair = diff_queue(&diff_queued_diff, one, two);
4766        pair->is_unmerged = 1;
4767        return pair;
4768}
4769
4770static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4771                size_t *outsize)
4772{
4773        struct diff_tempfile *temp;
4774        const char *argv[3];
4775        const char **arg = argv;
4776        struct child_process child;
4777        struct strbuf buf = STRBUF_INIT;
4778        int err = 0;
4779
4780        temp = prepare_temp_file(spec->path, spec);
4781        *arg++ = pgm;
4782        *arg++ = temp->name;
4783        *arg = NULL;
4784
4785        memset(&child, 0, sizeof(child));
4786        child.use_shell = 1;
4787        child.argv = argv;
4788        child.out = -1;
4789        if (start_command(&child)) {
4790                remove_tempfile();
4791                return NULL;
4792        }
4793
4794        if (strbuf_read(&buf, child.out, 0) < 0)
4795                err = error("error reading from textconv command '%s'", pgm);
4796        close(child.out);
4797
4798        if (finish_command(&child) || err) {
4799                strbuf_release(&buf);
4800                remove_tempfile();
4801                return NULL;
4802        }
4803        remove_tempfile();
4804
4805        return strbuf_detach(&buf, outsize);
4806}
4807
4808size_t fill_textconv(struct userdiff_driver *driver,
4809                     struct diff_filespec *df,
4810                     char **outbuf)
4811{
4812        size_t size;
4813
4814        if (!driver || !driver->textconv) {
4815                if (!DIFF_FILE_VALID(df)) {
4816                        *outbuf = "";
4817                        return 0;
4818                }
4819                if (diff_populate_filespec(df, 0))
4820                        die("unable to read files to diff");
4821                *outbuf = df->data;
4822                return df->size;
4823        }
4824
4825        if (driver->textconv_cache && df->sha1_valid) {
4826                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4827                                          &size);
4828                if (*outbuf)
4829                        return size;
4830        }
4831
4832        *outbuf = run_textconv(driver->textconv, df, &size);
4833        if (!*outbuf)
4834                die("unable to read files to diff");
4835
4836        if (driver->textconv_cache && df->sha1_valid) {
4837                /* ignore errors, as we might be in a readonly repository */
4838                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4839                                size);
4840                /*
4841                 * we could save up changes and flush them all at the end,
4842                 * but we would need an extra call after all diffing is done.
4843                 * Since generating a cache entry is the slow path anyway,
4844                 * this extra overhead probably isn't a big deal.
4845                 */
4846                notes_cache_write(driver->textconv_cache);
4847        }
4848
4849        return size;
4850}