diff.con commit wt-status.*: better advices for git status added (83c750a)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "delta.h"
   9#include "xdiff-interface.h"
  10#include "color.h"
  11#include "attr.h"
  12#include "run-command.h"
  13#include "utf8.h"
  14#include "userdiff.h"
  15#include "sigchain.h"
  16#include "submodule.h"
  17#include "ll-merge.h"
  18
  19#ifdef NO_FAST_WORKING_DIRECTORY
  20#define FAST_WORKING_DIRECTORY 0
  21#else
  22#define FAST_WORKING_DIRECTORY 1
  23#endif
  24
  25static int diff_detect_rename_default;
  26static int diff_rename_limit_default = 400;
  27static int diff_suppress_blank_empty;
  28int diff_use_color_default = -1;
  29static const char *diff_word_regex_cfg;
  30static const char *external_diff_cmd_cfg;
  31int diff_auto_refresh_index = 1;
  32static int diff_mnemonic_prefix;
  33static int diff_no_prefix;
  34static int diff_stat_graph_width;
  35static int diff_dirstat_permille_default = 30;
  36static struct diff_options default_diff_options;
  37
  38static char diff_colors[][COLOR_MAXLEN] = {
  39        GIT_COLOR_RESET,
  40        GIT_COLOR_NORMAL,       /* PLAIN */
  41        GIT_COLOR_BOLD,         /* METAINFO */
  42        GIT_COLOR_CYAN,         /* FRAGINFO */
  43        GIT_COLOR_RED,          /* OLD */
  44        GIT_COLOR_GREEN,        /* NEW */
  45        GIT_COLOR_YELLOW,       /* COMMIT */
  46        GIT_COLOR_BG_RED,       /* WHITESPACE */
  47        GIT_COLOR_NORMAL,       /* FUNCINFO */
  48};
  49
  50static int parse_diff_color_slot(const char *var, int ofs)
  51{
  52        if (!strcasecmp(var+ofs, "plain"))
  53                return DIFF_PLAIN;
  54        if (!strcasecmp(var+ofs, "meta"))
  55                return DIFF_METAINFO;
  56        if (!strcasecmp(var+ofs, "frag"))
  57                return DIFF_FRAGINFO;
  58        if (!strcasecmp(var+ofs, "old"))
  59                return DIFF_FILE_OLD;
  60        if (!strcasecmp(var+ofs, "new"))
  61                return DIFF_FILE_NEW;
  62        if (!strcasecmp(var+ofs, "commit"))
  63                return DIFF_COMMIT;
  64        if (!strcasecmp(var+ofs, "whitespace"))
  65                return DIFF_WHITESPACE;
  66        if (!strcasecmp(var+ofs, "func"))
  67                return DIFF_FUNCINFO;
  68        return -1;
  69}
  70
  71static int parse_dirstat_params(struct diff_options *options, const char *params,
  72                                struct strbuf *errmsg)
  73{
  74        const char *p = params;
  75        int p_len, ret = 0;
  76
  77        while (*p) {
  78                p_len = strchrnul(p, ',') - p;
  79                if (!memcmp(p, "changes", p_len)) {
  80                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  81                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  82                } else if (!memcmp(p, "lines", p_len)) {
  83                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
  84                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  85                } else if (!memcmp(p, "files", p_len)) {
  86                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  87                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
  88                } else if (!memcmp(p, "noncumulative", p_len)) {
  89                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
  90                } else if (!memcmp(p, "cumulative", p_len)) {
  91                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
  92                } else if (isdigit(*p)) {
  93                        char *end;
  94                        int permille = strtoul(p, &end, 10) * 10;
  95                        if (*end == '.' && isdigit(*++end)) {
  96                                /* only use first digit */
  97                                permille += *end - '0';
  98                                /* .. and ignore any further digits */
  99                                while (isdigit(*++end))
 100                                        ; /* nothing */
 101                        }
 102                        if (end - p == p_len)
 103                                options->dirstat_permille = permille;
 104                        else {
 105                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%.*s'\n"),
 106                                            p_len, p);
 107                                ret++;
 108                        }
 109                } else {
 110                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%.*s'\n"),
 111                                    p_len, p);
 112                        ret++;
 113                }
 114
 115                p += p_len;
 116
 117                if (*p)
 118                        p++; /* more parameters, swallow separator */
 119        }
 120        return ret;
 121}
 122
 123static int git_config_rename(const char *var, const char *value)
 124{
 125        if (!value)
 126                return DIFF_DETECT_RENAME;
 127        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 128                return  DIFF_DETECT_COPY;
 129        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 130}
 131
 132/*
 133 * These are to give UI layer defaults.
 134 * The core-level commands such as git-diff-files should
 135 * never be affected by the setting of diff.renames
 136 * the user happens to have in the configuration file.
 137 */
 138int git_diff_ui_config(const char *var, const char *value, void *cb)
 139{
 140        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 141                diff_use_color_default = git_config_colorbool(var, value);
 142                return 0;
 143        }
 144        if (!strcmp(var, "diff.renames")) {
 145                diff_detect_rename_default = git_config_rename(var, value);
 146                return 0;
 147        }
 148        if (!strcmp(var, "diff.autorefreshindex")) {
 149                diff_auto_refresh_index = git_config_bool(var, value);
 150                return 0;
 151        }
 152        if (!strcmp(var, "diff.mnemonicprefix")) {
 153                diff_mnemonic_prefix = git_config_bool(var, value);
 154                return 0;
 155        }
 156        if (!strcmp(var, "diff.noprefix")) {
 157                diff_no_prefix = git_config_bool(var, value);
 158                return 0;
 159        }
 160        if (!strcmp(var, "diff.statgraphwidth")) {
 161                diff_stat_graph_width = git_config_int(var, value);
 162                return 0;
 163        }
 164        if (!strcmp(var, "diff.external"))
 165                return git_config_string(&external_diff_cmd_cfg, var, value);
 166        if (!strcmp(var, "diff.wordregex"))
 167                return git_config_string(&diff_word_regex_cfg, var, value);
 168
 169        if (!strcmp(var, "diff.ignoresubmodules"))
 170                handle_ignore_submodules_arg(&default_diff_options, value);
 171
 172        if (git_color_config(var, value, cb) < 0)
 173                return -1;
 174
 175        return git_diff_basic_config(var, value, cb);
 176}
 177
 178int git_diff_basic_config(const char *var, const char *value, void *cb)
 179{
 180        if (!strcmp(var, "diff.renamelimit")) {
 181                diff_rename_limit_default = git_config_int(var, value);
 182                return 0;
 183        }
 184
 185        if (userdiff_config(var, value) < 0)
 186                return -1;
 187
 188        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 189                int slot = parse_diff_color_slot(var, 11);
 190                if (slot < 0)
 191                        return 0;
 192                if (!value)
 193                        return config_error_nonbool(var);
 194                color_parse(value, var, diff_colors[slot]);
 195                return 0;
 196        }
 197
 198        /* like GNU diff's --suppress-blank-empty option  */
 199        if (!strcmp(var, "diff.suppressblankempty") ||
 200                        /* for backwards compatibility */
 201                        !strcmp(var, "diff.suppress-blank-empty")) {
 202                diff_suppress_blank_empty = git_config_bool(var, value);
 203                return 0;
 204        }
 205
 206        if (!strcmp(var, "diff.dirstat")) {
 207                struct strbuf errmsg = STRBUF_INIT;
 208                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 209                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 210                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 211                                errmsg.buf);
 212                strbuf_release(&errmsg);
 213                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 214                return 0;
 215        }
 216
 217        if (!prefixcmp(var, "submodule."))
 218                return parse_submodule_config_option(var, value);
 219
 220        return git_default_config(var, value, cb);
 221}
 222
 223static char *quote_two(const char *one, const char *two)
 224{
 225        int need_one = quote_c_style(one, NULL, NULL, 1);
 226        int need_two = quote_c_style(two, NULL, NULL, 1);
 227        struct strbuf res = STRBUF_INIT;
 228
 229        if (need_one + need_two) {
 230                strbuf_addch(&res, '"');
 231                quote_c_style(one, &res, NULL, 1);
 232                quote_c_style(two, &res, NULL, 1);
 233                strbuf_addch(&res, '"');
 234        } else {
 235                strbuf_addstr(&res, one);
 236                strbuf_addstr(&res, two);
 237        }
 238        return strbuf_detach(&res, NULL);
 239}
 240
 241static const char *external_diff(void)
 242{
 243        static const char *external_diff_cmd = NULL;
 244        static int done_preparing = 0;
 245
 246        if (done_preparing)
 247                return external_diff_cmd;
 248        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 249        if (!external_diff_cmd)
 250                external_diff_cmd = external_diff_cmd_cfg;
 251        done_preparing = 1;
 252        return external_diff_cmd;
 253}
 254
 255static struct diff_tempfile {
 256        const char *name; /* filename external diff should read from */
 257        char hex[41];
 258        char mode[10];
 259        char tmp_path[PATH_MAX];
 260} diff_temp[2];
 261
 262typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 263
 264struct emit_callback {
 265        int color_diff;
 266        unsigned ws_rule;
 267        int blank_at_eof_in_preimage;
 268        int blank_at_eof_in_postimage;
 269        int lno_in_preimage;
 270        int lno_in_postimage;
 271        sane_truncate_fn truncate;
 272        const char **label_path;
 273        struct diff_words_data *diff_words;
 274        struct diff_options *opt;
 275        int *found_changesp;
 276        struct strbuf *header;
 277};
 278
 279static int count_lines(const char *data, int size)
 280{
 281        int count, ch, completely_empty = 1, nl_just_seen = 0;
 282        count = 0;
 283        while (0 < size--) {
 284                ch = *data++;
 285                if (ch == '\n') {
 286                        count++;
 287                        nl_just_seen = 1;
 288                        completely_empty = 0;
 289                }
 290                else {
 291                        nl_just_seen = 0;
 292                        completely_empty = 0;
 293                }
 294        }
 295        if (completely_empty)
 296                return 0;
 297        if (!nl_just_seen)
 298                count++; /* no trailing newline */
 299        return count;
 300}
 301
 302static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 303{
 304        if (!DIFF_FILE_VALID(one)) {
 305                mf->ptr = (char *)""; /* does not matter */
 306                mf->size = 0;
 307                return 0;
 308        }
 309        else if (diff_populate_filespec(one, 0))
 310                return -1;
 311
 312        mf->ptr = one->data;
 313        mf->size = one->size;
 314        return 0;
 315}
 316
 317/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 318static unsigned long diff_filespec_size(struct diff_filespec *one)
 319{
 320        if (!DIFF_FILE_VALID(one))
 321                return 0;
 322        diff_populate_filespec(one, 1);
 323        return one->size;
 324}
 325
 326static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 327{
 328        char *ptr = mf->ptr;
 329        long size = mf->size;
 330        int cnt = 0;
 331
 332        if (!size)
 333                return cnt;
 334        ptr += size - 1; /* pointing at the very end */
 335        if (*ptr != '\n')
 336                ; /* incomplete line */
 337        else
 338                ptr--; /* skip the last LF */
 339        while (mf->ptr < ptr) {
 340                char *prev_eol;
 341                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 342                        if (*prev_eol == '\n')
 343                                break;
 344                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 345                        break;
 346                cnt++;
 347                ptr = prev_eol - 1;
 348        }
 349        return cnt;
 350}
 351
 352static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 353                               struct emit_callback *ecbdata)
 354{
 355        int l1, l2, at;
 356        unsigned ws_rule = ecbdata->ws_rule;
 357        l1 = count_trailing_blank(mf1, ws_rule);
 358        l2 = count_trailing_blank(mf2, ws_rule);
 359        if (l2 <= l1) {
 360                ecbdata->blank_at_eof_in_preimage = 0;
 361                ecbdata->blank_at_eof_in_postimage = 0;
 362                return;
 363        }
 364        at = count_lines(mf1->ptr, mf1->size);
 365        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 366
 367        at = count_lines(mf2->ptr, mf2->size);
 368        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 369}
 370
 371static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 372                        int first, const char *line, int len)
 373{
 374        int has_trailing_newline, has_trailing_carriage_return;
 375        int nofirst;
 376        FILE *file = o->file;
 377
 378        if (o->output_prefix) {
 379                struct strbuf *msg = NULL;
 380                msg = o->output_prefix(o, o->output_prefix_data);
 381                assert(msg);
 382                fwrite(msg->buf, msg->len, 1, file);
 383        }
 384
 385        if (len == 0) {
 386                has_trailing_newline = (first == '\n');
 387                has_trailing_carriage_return = (!has_trailing_newline &&
 388                                                (first == '\r'));
 389                nofirst = has_trailing_newline || has_trailing_carriage_return;
 390        } else {
 391                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 392                if (has_trailing_newline)
 393                        len--;
 394                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 395                if (has_trailing_carriage_return)
 396                        len--;
 397                nofirst = 0;
 398        }
 399
 400        if (len || !nofirst) {
 401                fputs(set, file);
 402                if (!nofirst)
 403                        fputc(first, file);
 404                fwrite(line, len, 1, file);
 405                fputs(reset, file);
 406        }
 407        if (has_trailing_carriage_return)
 408                fputc('\r', file);
 409        if (has_trailing_newline)
 410                fputc('\n', file);
 411}
 412
 413static void emit_line(struct diff_options *o, const char *set, const char *reset,
 414                      const char *line, int len)
 415{
 416        emit_line_0(o, set, reset, line[0], line+1, len-1);
 417}
 418
 419static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 420{
 421        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 422              ecbdata->blank_at_eof_in_preimage &&
 423              ecbdata->blank_at_eof_in_postimage &&
 424              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 425              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 426                return 0;
 427        return ws_blank_line(line, len, ecbdata->ws_rule);
 428}
 429
 430static void emit_add_line(const char *reset,
 431                          struct emit_callback *ecbdata,
 432                          const char *line, int len)
 433{
 434        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 435        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 436
 437        if (!*ws)
 438                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 439        else if (new_blank_line_at_eof(ecbdata, line, len))
 440                /* Blank line at EOF - paint '+' as well */
 441                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 442        else {
 443                /* Emit just the prefix, then the rest. */
 444                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 445                ws_check_emit(line, len, ecbdata->ws_rule,
 446                              ecbdata->opt->file, set, reset, ws);
 447        }
 448}
 449
 450static void emit_hunk_header(struct emit_callback *ecbdata,
 451                             const char *line, int len)
 452{
 453        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 454        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 455        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 456        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 457        static const char atat[2] = { '@', '@' };
 458        const char *cp, *ep;
 459        struct strbuf msgbuf = STRBUF_INIT;
 460        int org_len = len;
 461        int i = 1;
 462
 463        /*
 464         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 465         * it always is at least 10 bytes long.
 466         */
 467        if (len < 10 ||
 468            memcmp(line, atat, 2) ||
 469            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 470                emit_line(ecbdata->opt, plain, reset, line, len);
 471                return;
 472        }
 473        ep += 2; /* skip over @@ */
 474
 475        /* The hunk header in fraginfo color */
 476        strbuf_add(&msgbuf, frag, strlen(frag));
 477        strbuf_add(&msgbuf, line, ep - line);
 478        strbuf_add(&msgbuf, reset, strlen(reset));
 479
 480        /*
 481         * trailing "\r\n"
 482         */
 483        for ( ; i < 3; i++)
 484                if (line[len - i] == '\r' || line[len - i] == '\n')
 485                        len--;
 486
 487        /* blank before the func header */
 488        for (cp = ep; ep - line < len; ep++)
 489                if (*ep != ' ' && *ep != '\t')
 490                        break;
 491        if (ep != cp) {
 492                strbuf_add(&msgbuf, plain, strlen(plain));
 493                strbuf_add(&msgbuf, cp, ep - cp);
 494                strbuf_add(&msgbuf, reset, strlen(reset));
 495        }
 496
 497        if (ep < line + len) {
 498                strbuf_add(&msgbuf, func, strlen(func));
 499                strbuf_add(&msgbuf, ep, line + len - ep);
 500                strbuf_add(&msgbuf, reset, strlen(reset));
 501        }
 502
 503        strbuf_add(&msgbuf, line + len, org_len - len);
 504        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 505        strbuf_release(&msgbuf);
 506}
 507
 508static struct diff_tempfile *claim_diff_tempfile(void) {
 509        int i;
 510        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 511                if (!diff_temp[i].name)
 512                        return diff_temp + i;
 513        die("BUG: diff is failing to clean up its tempfiles");
 514}
 515
 516static int remove_tempfile_installed;
 517
 518static void remove_tempfile(void)
 519{
 520        int i;
 521        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 522                if (diff_temp[i].name == diff_temp[i].tmp_path)
 523                        unlink_or_warn(diff_temp[i].name);
 524                diff_temp[i].name = NULL;
 525        }
 526}
 527
 528static void remove_tempfile_on_signal(int signo)
 529{
 530        remove_tempfile();
 531        sigchain_pop(signo);
 532        raise(signo);
 533}
 534
 535static void print_line_count(FILE *file, int count)
 536{
 537        switch (count) {
 538        case 0:
 539                fprintf(file, "0,0");
 540                break;
 541        case 1:
 542                fprintf(file, "1");
 543                break;
 544        default:
 545                fprintf(file, "1,%d", count);
 546                break;
 547        }
 548}
 549
 550static void emit_rewrite_lines(struct emit_callback *ecb,
 551                               int prefix, const char *data, int size)
 552{
 553        const char *endp = NULL;
 554        static const char *nneof = " No newline at end of file\n";
 555        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 556        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 557
 558        while (0 < size) {
 559                int len;
 560
 561                endp = memchr(data, '\n', size);
 562                len = endp ? (endp - data + 1) : size;
 563                if (prefix != '+') {
 564                        ecb->lno_in_preimage++;
 565                        emit_line_0(ecb->opt, old, reset, '-',
 566                                    data, len);
 567                } else {
 568                        ecb->lno_in_postimage++;
 569                        emit_add_line(reset, ecb, data, len);
 570                }
 571                size -= len;
 572                data += len;
 573        }
 574        if (!endp) {
 575                const char *plain = diff_get_color(ecb->color_diff,
 576                                                   DIFF_PLAIN);
 577                emit_line_0(ecb->opt, plain, reset, '\\',
 578                            nneof, strlen(nneof));
 579        }
 580}
 581
 582static void emit_rewrite_diff(const char *name_a,
 583                              const char *name_b,
 584                              struct diff_filespec *one,
 585                              struct diff_filespec *two,
 586                              struct userdiff_driver *textconv_one,
 587                              struct userdiff_driver *textconv_two,
 588                              struct diff_options *o)
 589{
 590        int lc_a, lc_b;
 591        const char *name_a_tab, *name_b_tab;
 592        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 593        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 594        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 595        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 596        const char *a_prefix, *b_prefix;
 597        char *data_one, *data_two;
 598        size_t size_one, size_two;
 599        struct emit_callback ecbdata;
 600        char *line_prefix = "";
 601        struct strbuf *msgbuf;
 602
 603        if (o && o->output_prefix) {
 604                msgbuf = o->output_prefix(o, o->output_prefix_data);
 605                line_prefix = msgbuf->buf;
 606        }
 607
 608        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 609                a_prefix = o->b_prefix;
 610                b_prefix = o->a_prefix;
 611        } else {
 612                a_prefix = o->a_prefix;
 613                b_prefix = o->b_prefix;
 614        }
 615
 616        name_a += (*name_a == '/');
 617        name_b += (*name_b == '/');
 618        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 619        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 620
 621        strbuf_reset(&a_name);
 622        strbuf_reset(&b_name);
 623        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 624        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 625
 626        size_one = fill_textconv(textconv_one, one, &data_one);
 627        size_two = fill_textconv(textconv_two, two, &data_two);
 628
 629        memset(&ecbdata, 0, sizeof(ecbdata));
 630        ecbdata.color_diff = want_color(o->use_color);
 631        ecbdata.found_changesp = &o->found_changes;
 632        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 633        ecbdata.opt = o;
 634        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 635                mmfile_t mf1, mf2;
 636                mf1.ptr = (char *)data_one;
 637                mf2.ptr = (char *)data_two;
 638                mf1.size = size_one;
 639                mf2.size = size_two;
 640                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 641        }
 642        ecbdata.lno_in_preimage = 1;
 643        ecbdata.lno_in_postimage = 1;
 644
 645        lc_a = count_lines(data_one, size_one);
 646        lc_b = count_lines(data_two, size_two);
 647        fprintf(o->file,
 648                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 649                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 650                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 651                line_prefix, fraginfo);
 652        if (!o->irreversible_delete)
 653                print_line_count(o->file, lc_a);
 654        else
 655                fprintf(o->file, "?,?");
 656        fprintf(o->file, " +");
 657        print_line_count(o->file, lc_b);
 658        fprintf(o->file, " @@%s\n", reset);
 659        if (lc_a && !o->irreversible_delete)
 660                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 661        if (lc_b)
 662                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 663        if (textconv_one)
 664                free((char *)data_one);
 665        if (textconv_two)
 666                free((char *)data_two);
 667}
 668
 669struct diff_words_buffer {
 670        mmfile_t text;
 671        long alloc;
 672        struct diff_words_orig {
 673                const char *begin, *end;
 674        } *orig;
 675        int orig_nr, orig_alloc;
 676};
 677
 678static void diff_words_append(char *line, unsigned long len,
 679                struct diff_words_buffer *buffer)
 680{
 681        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 682        line++;
 683        len--;
 684        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 685        buffer->text.size += len;
 686        buffer->text.ptr[buffer->text.size] = '\0';
 687}
 688
 689struct diff_words_style_elem {
 690        const char *prefix;
 691        const char *suffix;
 692        const char *color; /* NULL; filled in by the setup code if
 693                            * color is enabled */
 694};
 695
 696struct diff_words_style {
 697        enum diff_words_type type;
 698        struct diff_words_style_elem new, old, ctx;
 699        const char *newline;
 700};
 701
 702static struct diff_words_style diff_words_styles[] = {
 703        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 704        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 705        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 706};
 707
 708struct diff_words_data {
 709        struct diff_words_buffer minus, plus;
 710        const char *current_plus;
 711        int last_minus;
 712        struct diff_options *opt;
 713        regex_t *word_regex;
 714        enum diff_words_type type;
 715        struct diff_words_style *style;
 716};
 717
 718static int fn_out_diff_words_write_helper(FILE *fp,
 719                                          struct diff_words_style_elem *st_el,
 720                                          const char *newline,
 721                                          size_t count, const char *buf,
 722                                          const char *line_prefix)
 723{
 724        int print = 0;
 725
 726        while (count) {
 727                char *p = memchr(buf, '\n', count);
 728                if (print)
 729                        fputs(line_prefix, fp);
 730                if (p != buf) {
 731                        if (st_el->color && fputs(st_el->color, fp) < 0)
 732                                return -1;
 733                        if (fputs(st_el->prefix, fp) < 0 ||
 734                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 735                            fputs(st_el->suffix, fp) < 0)
 736                                return -1;
 737                        if (st_el->color && *st_el->color
 738                            && fputs(GIT_COLOR_RESET, fp) < 0)
 739                                return -1;
 740                }
 741                if (!p)
 742                        return 0;
 743                if (fputs(newline, fp) < 0)
 744                        return -1;
 745                count -= p + 1 - buf;
 746                buf = p + 1;
 747                print = 1;
 748        }
 749        return 0;
 750}
 751
 752/*
 753 * '--color-words' algorithm can be described as:
 754 *
 755 *   1. collect a the minus/plus lines of a diff hunk, divided into
 756 *      minus-lines and plus-lines;
 757 *
 758 *   2. break both minus-lines and plus-lines into words and
 759 *      place them into two mmfile_t with one word for each line;
 760 *
 761 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 762 *
 763 * And for the common parts of the both file, we output the plus side text.
 764 * diff_words->current_plus is used to trace the current position of the plus file
 765 * which printed. diff_words->last_minus is used to trace the last minus word
 766 * printed.
 767 *
 768 * For '--graph' to work with '--color-words', we need to output the graph prefix
 769 * on each line of color words output. Generally, there are two conditions on
 770 * which we should output the prefix.
 771 *
 772 *   1. diff_words->last_minus == 0 &&
 773 *      diff_words->current_plus == diff_words->plus.text.ptr
 774 *
 775 *      that is: the plus text must start as a new line, and if there is no minus
 776 *      word printed, a graph prefix must be printed.
 777 *
 778 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 779 *      *(diff_words->current_plus - 1) == '\n'
 780 *
 781 *      that is: a graph prefix must be printed following a '\n'
 782 */
 783static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 784{
 785        if ((diff_words->last_minus == 0 &&
 786                diff_words->current_plus == diff_words->plus.text.ptr) ||
 787                (diff_words->current_plus > diff_words->plus.text.ptr &&
 788                *(diff_words->current_plus - 1) == '\n')) {
 789                return 1;
 790        } else {
 791                return 0;
 792        }
 793}
 794
 795static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 796{
 797        struct diff_words_data *diff_words = priv;
 798        struct diff_words_style *style = diff_words->style;
 799        int minus_first, minus_len, plus_first, plus_len;
 800        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 801        struct diff_options *opt = diff_words->opt;
 802        struct strbuf *msgbuf;
 803        char *line_prefix = "";
 804
 805        if (line[0] != '@' || parse_hunk_header(line, len,
 806                        &minus_first, &minus_len, &plus_first, &plus_len))
 807                return;
 808
 809        assert(opt);
 810        if (opt->output_prefix) {
 811                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 812                line_prefix = msgbuf->buf;
 813        }
 814
 815        /* POSIX requires that first be decremented by one if len == 0... */
 816        if (minus_len) {
 817                minus_begin = diff_words->minus.orig[minus_first].begin;
 818                minus_end =
 819                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 820        } else
 821                minus_begin = minus_end =
 822                        diff_words->minus.orig[minus_first].end;
 823
 824        if (plus_len) {
 825                plus_begin = diff_words->plus.orig[plus_first].begin;
 826                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 827        } else
 828                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 829
 830        if (color_words_output_graph_prefix(diff_words)) {
 831                fputs(line_prefix, diff_words->opt->file);
 832        }
 833        if (diff_words->current_plus != plus_begin) {
 834                fn_out_diff_words_write_helper(diff_words->opt->file,
 835                                &style->ctx, style->newline,
 836                                plus_begin - diff_words->current_plus,
 837                                diff_words->current_plus, line_prefix);
 838                if (*(plus_begin - 1) == '\n')
 839                        fputs(line_prefix, diff_words->opt->file);
 840        }
 841        if (minus_begin != minus_end) {
 842                fn_out_diff_words_write_helper(diff_words->opt->file,
 843                                &style->old, style->newline,
 844                                minus_end - minus_begin, minus_begin,
 845                                line_prefix);
 846        }
 847        if (plus_begin != plus_end) {
 848                fn_out_diff_words_write_helper(diff_words->opt->file,
 849                                &style->new, style->newline,
 850                                plus_end - plus_begin, plus_begin,
 851                                line_prefix);
 852        }
 853
 854        diff_words->current_plus = plus_end;
 855        diff_words->last_minus = minus_first;
 856}
 857
 858/* This function starts looking at *begin, and returns 0 iff a word was found. */
 859static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 860                int *begin, int *end)
 861{
 862        if (word_regex && *begin < buffer->size) {
 863                regmatch_t match[1];
 864                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 865                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 866                                        '\n', match[0].rm_eo - match[0].rm_so);
 867                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 868                        *begin += match[0].rm_so;
 869                        return *begin >= *end;
 870                }
 871                return -1;
 872        }
 873
 874        /* find the next word */
 875        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 876                (*begin)++;
 877        if (*begin >= buffer->size)
 878                return -1;
 879
 880        /* find the end of the word */
 881        *end = *begin + 1;
 882        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 883                (*end)++;
 884
 885        return 0;
 886}
 887
 888/*
 889 * This function splits the words in buffer->text, stores the list with
 890 * newline separator into out, and saves the offsets of the original words
 891 * in buffer->orig.
 892 */
 893static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 894                regex_t *word_regex)
 895{
 896        int i, j;
 897        long alloc = 0;
 898
 899        out->size = 0;
 900        out->ptr = NULL;
 901
 902        /* fake an empty "0th" word */
 903        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 904        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 905        buffer->orig_nr = 1;
 906
 907        for (i = 0; i < buffer->text.size; i++) {
 908                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 909                        return;
 910
 911                /* store original boundaries */
 912                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 913                                buffer->orig_alloc);
 914                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 915                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 916                buffer->orig_nr++;
 917
 918                /* store one word */
 919                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 920                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 921                out->ptr[out->size + j - i] = '\n';
 922                out->size += j - i + 1;
 923
 924                i = j - 1;
 925        }
 926}
 927
 928/* this executes the word diff on the accumulated buffers */
 929static void diff_words_show(struct diff_words_data *diff_words)
 930{
 931        xpparam_t xpp;
 932        xdemitconf_t xecfg;
 933        mmfile_t minus, plus;
 934        struct diff_words_style *style = diff_words->style;
 935
 936        struct diff_options *opt = diff_words->opt;
 937        struct strbuf *msgbuf;
 938        char *line_prefix = "";
 939
 940        assert(opt);
 941        if (opt->output_prefix) {
 942                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 943                line_prefix = msgbuf->buf;
 944        }
 945
 946        /* special case: only removal */
 947        if (!diff_words->plus.text.size) {
 948                fputs(line_prefix, diff_words->opt->file);
 949                fn_out_diff_words_write_helper(diff_words->opt->file,
 950                        &style->old, style->newline,
 951                        diff_words->minus.text.size,
 952                        diff_words->minus.text.ptr, line_prefix);
 953                diff_words->minus.text.size = 0;
 954                return;
 955        }
 956
 957        diff_words->current_plus = diff_words->plus.text.ptr;
 958        diff_words->last_minus = 0;
 959
 960        memset(&xpp, 0, sizeof(xpp));
 961        memset(&xecfg, 0, sizeof(xecfg));
 962        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 963        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 964        xpp.flags = 0;
 965        /* as only the hunk header will be parsed, we need a 0-context */
 966        xecfg.ctxlen = 0;
 967        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 968                      &xpp, &xecfg);
 969        free(minus.ptr);
 970        free(plus.ptr);
 971        if (diff_words->current_plus != diff_words->plus.text.ptr +
 972                        diff_words->plus.text.size) {
 973                if (color_words_output_graph_prefix(diff_words))
 974                        fputs(line_prefix, diff_words->opt->file);
 975                fn_out_diff_words_write_helper(diff_words->opt->file,
 976                        &style->ctx, style->newline,
 977                        diff_words->plus.text.ptr + diff_words->plus.text.size
 978                        - diff_words->current_plus, diff_words->current_plus,
 979                        line_prefix);
 980        }
 981        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 982}
 983
 984/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 985static void diff_words_flush(struct emit_callback *ecbdata)
 986{
 987        if (ecbdata->diff_words->minus.text.size ||
 988            ecbdata->diff_words->plus.text.size)
 989                diff_words_show(ecbdata->diff_words);
 990}
 991
 992static void diff_filespec_load_driver(struct diff_filespec *one)
 993{
 994        /* Use already-loaded driver */
 995        if (one->driver)
 996                return;
 997
 998        if (S_ISREG(one->mode))
 999                one->driver = userdiff_find_by_path(one->path);
1000
1001        /* Fallback to default settings */
1002        if (!one->driver)
1003                one->driver = userdiff_find_by_name("default");
1004}
1005
1006static const char *userdiff_word_regex(struct diff_filespec *one)
1007{
1008        diff_filespec_load_driver(one);
1009        return one->driver->word_regex;
1010}
1011
1012static void init_diff_words_data(struct emit_callback *ecbdata,
1013                                 struct diff_options *orig_opts,
1014                                 struct diff_filespec *one,
1015                                 struct diff_filespec *two)
1016{
1017        int i;
1018        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1019        memcpy(o, orig_opts, sizeof(struct diff_options));
1020
1021        ecbdata->diff_words =
1022                xcalloc(1, sizeof(struct diff_words_data));
1023        ecbdata->diff_words->type = o->word_diff;
1024        ecbdata->diff_words->opt = o;
1025        if (!o->word_regex)
1026                o->word_regex = userdiff_word_regex(one);
1027        if (!o->word_regex)
1028                o->word_regex = userdiff_word_regex(two);
1029        if (!o->word_regex)
1030                o->word_regex = diff_word_regex_cfg;
1031        if (o->word_regex) {
1032                ecbdata->diff_words->word_regex = (regex_t *)
1033                        xmalloc(sizeof(regex_t));
1034                if (regcomp(ecbdata->diff_words->word_regex,
1035                            o->word_regex,
1036                            REG_EXTENDED | REG_NEWLINE))
1037                        die ("Invalid regular expression: %s",
1038                             o->word_regex);
1039        }
1040        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1041                if (o->word_diff == diff_words_styles[i].type) {
1042                        ecbdata->diff_words->style =
1043                                &diff_words_styles[i];
1044                        break;
1045                }
1046        }
1047        if (want_color(o->use_color)) {
1048                struct diff_words_style *st = ecbdata->diff_words->style;
1049                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1050                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1051                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
1052        }
1053}
1054
1055static void free_diff_words_data(struct emit_callback *ecbdata)
1056{
1057        if (ecbdata->diff_words) {
1058                diff_words_flush(ecbdata);
1059                free (ecbdata->diff_words->opt);
1060                free (ecbdata->diff_words->minus.text.ptr);
1061                free (ecbdata->diff_words->minus.orig);
1062                free (ecbdata->diff_words->plus.text.ptr);
1063                free (ecbdata->diff_words->plus.orig);
1064                if (ecbdata->diff_words->word_regex) {
1065                        regfree(ecbdata->diff_words->word_regex);
1066                        free(ecbdata->diff_words->word_regex);
1067                }
1068                free(ecbdata->diff_words);
1069                ecbdata->diff_words = NULL;
1070        }
1071}
1072
1073const char *diff_get_color(int diff_use_color, enum color_diff ix)
1074{
1075        if (want_color(diff_use_color))
1076                return diff_colors[ix];
1077        return "";
1078}
1079
1080static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1081{
1082        const char *cp;
1083        unsigned long allot;
1084        size_t l = len;
1085
1086        if (ecb->truncate)
1087                return ecb->truncate(line, len);
1088        cp = line;
1089        allot = l;
1090        while (0 < l) {
1091                (void) utf8_width(&cp, &l);
1092                if (!cp)
1093                        break; /* truncated in the middle? */
1094        }
1095        return allot - l;
1096}
1097
1098static void find_lno(const char *line, struct emit_callback *ecbdata)
1099{
1100        const char *p;
1101        ecbdata->lno_in_preimage = 0;
1102        ecbdata->lno_in_postimage = 0;
1103        p = strchr(line, '-');
1104        if (!p)
1105                return; /* cannot happen */
1106        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1107        p = strchr(p, '+');
1108        if (!p)
1109                return; /* cannot happen */
1110        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1111}
1112
1113static void fn_out_consume(void *priv, char *line, unsigned long len)
1114{
1115        struct emit_callback *ecbdata = priv;
1116        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1117        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1118        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1119        struct diff_options *o = ecbdata->opt;
1120        char *line_prefix = "";
1121        struct strbuf *msgbuf;
1122
1123        if (o && o->output_prefix) {
1124                msgbuf = o->output_prefix(o, o->output_prefix_data);
1125                line_prefix = msgbuf->buf;
1126        }
1127
1128        if (ecbdata->header) {
1129                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1130                strbuf_reset(ecbdata->header);
1131                ecbdata->header = NULL;
1132        }
1133        *(ecbdata->found_changesp) = 1;
1134
1135        if (ecbdata->label_path[0]) {
1136                const char *name_a_tab, *name_b_tab;
1137
1138                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1139                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1140
1141                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1142                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1143                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1144                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1145                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1146        }
1147
1148        if (diff_suppress_blank_empty
1149            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1150                line[0] = '\n';
1151                len = 1;
1152        }
1153
1154        if (line[0] == '@') {
1155                if (ecbdata->diff_words)
1156                        diff_words_flush(ecbdata);
1157                len = sane_truncate_line(ecbdata, line, len);
1158                find_lno(line, ecbdata);
1159                emit_hunk_header(ecbdata, line, len);
1160                if (line[len-1] != '\n')
1161                        putc('\n', ecbdata->opt->file);
1162                return;
1163        }
1164
1165        if (len < 1) {
1166                emit_line(ecbdata->opt, reset, reset, line, len);
1167                if (ecbdata->diff_words
1168                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1169                        fputs("~\n", ecbdata->opt->file);
1170                return;
1171        }
1172
1173        if (ecbdata->diff_words) {
1174                if (line[0] == '-') {
1175                        diff_words_append(line, len,
1176                                          &ecbdata->diff_words->minus);
1177                        return;
1178                } else if (line[0] == '+') {
1179                        diff_words_append(line, len,
1180                                          &ecbdata->diff_words->plus);
1181                        return;
1182                } else if (!prefixcmp(line, "\\ ")) {
1183                        /*
1184                         * Eat the "no newline at eof" marker as if we
1185                         * saw a "+" or "-" line with nothing on it,
1186                         * and return without diff_words_flush() to
1187                         * defer processing. If this is the end of
1188                         * preimage, more "+" lines may come after it.
1189                         */
1190                        return;
1191                }
1192                diff_words_flush(ecbdata);
1193                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1194                        emit_line(ecbdata->opt, plain, reset, line, len);
1195                        fputs("~\n", ecbdata->opt->file);
1196                } else {
1197                        /*
1198                         * Skip the prefix character, if any.  With
1199                         * diff_suppress_blank_empty, there may be
1200                         * none.
1201                         */
1202                        if (line[0] != '\n') {
1203                              line++;
1204                              len--;
1205                        }
1206                        emit_line(ecbdata->opt, plain, reset, line, len);
1207                }
1208                return;
1209        }
1210
1211        if (line[0] != '+') {
1212                const char *color =
1213                        diff_get_color(ecbdata->color_diff,
1214                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1215                ecbdata->lno_in_preimage++;
1216                if (line[0] == ' ')
1217                        ecbdata->lno_in_postimage++;
1218                emit_line(ecbdata->opt, color, reset, line, len);
1219        } else {
1220                ecbdata->lno_in_postimage++;
1221                emit_add_line(reset, ecbdata, line + 1, len - 1);
1222        }
1223}
1224
1225static char *pprint_rename(const char *a, const char *b)
1226{
1227        const char *old = a;
1228        const char *new = b;
1229        struct strbuf name = STRBUF_INIT;
1230        int pfx_length, sfx_length;
1231        int len_a = strlen(a);
1232        int len_b = strlen(b);
1233        int a_midlen, b_midlen;
1234        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1235        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1236
1237        if (qlen_a || qlen_b) {
1238                quote_c_style(a, &name, NULL, 0);
1239                strbuf_addstr(&name, " => ");
1240                quote_c_style(b, &name, NULL, 0);
1241                return strbuf_detach(&name, NULL);
1242        }
1243
1244        /* Find common prefix */
1245        pfx_length = 0;
1246        while (*old && *new && *old == *new) {
1247                if (*old == '/')
1248                        pfx_length = old - a + 1;
1249                old++;
1250                new++;
1251        }
1252
1253        /* Find common suffix */
1254        old = a + len_a;
1255        new = b + len_b;
1256        sfx_length = 0;
1257        while (a <= old && b <= new && *old == *new) {
1258                if (*old == '/')
1259                        sfx_length = len_a - (old - a);
1260                old--;
1261                new--;
1262        }
1263
1264        /*
1265         * pfx{mid-a => mid-b}sfx
1266         * {pfx-a => pfx-b}sfx
1267         * pfx{sfx-a => sfx-b}
1268         * name-a => name-b
1269         */
1270        a_midlen = len_a - pfx_length - sfx_length;
1271        b_midlen = len_b - pfx_length - sfx_length;
1272        if (a_midlen < 0)
1273                a_midlen = 0;
1274        if (b_midlen < 0)
1275                b_midlen = 0;
1276
1277        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1278        if (pfx_length + sfx_length) {
1279                strbuf_add(&name, a, pfx_length);
1280                strbuf_addch(&name, '{');
1281        }
1282        strbuf_add(&name, a + pfx_length, a_midlen);
1283        strbuf_addstr(&name, " => ");
1284        strbuf_add(&name, b + pfx_length, b_midlen);
1285        if (pfx_length + sfx_length) {
1286                strbuf_addch(&name, '}');
1287                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1288        }
1289        return strbuf_detach(&name, NULL);
1290}
1291
1292struct diffstat_t {
1293        int nr;
1294        int alloc;
1295        struct diffstat_file {
1296                char *from_name;
1297                char *name;
1298                char *print_name;
1299                unsigned is_unmerged:1;
1300                unsigned is_binary:1;
1301                unsigned is_renamed:1;
1302                uintmax_t added, deleted;
1303        } **files;
1304};
1305
1306static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1307                                          const char *name_a,
1308                                          const char *name_b)
1309{
1310        struct diffstat_file *x;
1311        x = xcalloc(sizeof (*x), 1);
1312        if (diffstat->nr == diffstat->alloc) {
1313                diffstat->alloc = alloc_nr(diffstat->alloc);
1314                diffstat->files = xrealloc(diffstat->files,
1315                                diffstat->alloc * sizeof(x));
1316        }
1317        diffstat->files[diffstat->nr++] = x;
1318        if (name_b) {
1319                x->from_name = xstrdup(name_a);
1320                x->name = xstrdup(name_b);
1321                x->is_renamed = 1;
1322        }
1323        else {
1324                x->from_name = NULL;
1325                x->name = xstrdup(name_a);
1326        }
1327        return x;
1328}
1329
1330static void diffstat_consume(void *priv, char *line, unsigned long len)
1331{
1332        struct diffstat_t *diffstat = priv;
1333        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1334
1335        if (line[0] == '+')
1336                x->added++;
1337        else if (line[0] == '-')
1338                x->deleted++;
1339}
1340
1341const char mime_boundary_leader[] = "------------";
1342
1343static int scale_linear(int it, int width, int max_change)
1344{
1345        if (!it)
1346                return 0;
1347        /*
1348         * make sure that at least one '-' or '+' is printed if
1349         * there is any change to this path. The easiest way is to
1350         * scale linearly as if the alloted width is one column shorter
1351         * than it is, and then add 1 to the result.
1352         */
1353        return 1 + (it * (width - 1) / max_change);
1354}
1355
1356static void show_name(FILE *file,
1357                      const char *prefix, const char *name, int len)
1358{
1359        fprintf(file, " %s%-*s |", prefix, len, name);
1360}
1361
1362static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1363{
1364        if (cnt <= 0)
1365                return;
1366        fprintf(file, "%s", set);
1367        while (cnt--)
1368                putc(ch, file);
1369        fprintf(file, "%s", reset);
1370}
1371
1372static void fill_print_name(struct diffstat_file *file)
1373{
1374        char *pname;
1375
1376        if (file->print_name)
1377                return;
1378
1379        if (!file->is_renamed) {
1380                struct strbuf buf = STRBUF_INIT;
1381                if (quote_c_style(file->name, &buf, NULL, 0)) {
1382                        pname = strbuf_detach(&buf, NULL);
1383                } else {
1384                        pname = file->name;
1385                        strbuf_release(&buf);
1386                }
1387        } else {
1388                pname = pprint_rename(file->from_name, file->name);
1389        }
1390        file->print_name = pname;
1391}
1392
1393int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1394{
1395        struct strbuf sb = STRBUF_INIT;
1396        int ret;
1397
1398        if (!files) {
1399                assert(insertions == 0 && deletions == 0);
1400                return fputs(_(" 0 files changed\n"), fp);
1401        }
1402
1403        strbuf_addf(&sb,
1404                    Q_(" %d file changed", " %d files changed", files),
1405                    files);
1406
1407        /*
1408         * For binary diff, the caller may want to print "x files
1409         * changed" with insertions == 0 && deletions == 0.
1410         *
1411         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1412         * is probably less confusing (i.e skip over "2 files changed
1413         * but nothing about added/removed lines? Is this a bug in Git?").
1414         */
1415        if (insertions || deletions == 0) {
1416                /*
1417                 * TRANSLATORS: "+" in (+) is a line addition marker;
1418                 * do not translate it.
1419                 */
1420                strbuf_addf(&sb,
1421                            Q_(", %d insertion(+)", ", %d insertions(+)",
1422                               insertions),
1423                            insertions);
1424        }
1425
1426        if (deletions || insertions == 0) {
1427                /*
1428                 * TRANSLATORS: "-" in (-) is a line removal marker;
1429                 * do not translate it.
1430                 */
1431                strbuf_addf(&sb,
1432                            Q_(", %d deletion(-)", ", %d deletions(-)",
1433                               deletions),
1434                            deletions);
1435        }
1436        strbuf_addch(&sb, '\n');
1437        ret = fputs(sb.buf, fp);
1438        strbuf_release(&sb);
1439        return ret;
1440}
1441
1442static void show_stats(struct diffstat_t *data, struct diff_options *options)
1443{
1444        int i, len, add, del, adds = 0, dels = 0;
1445        uintmax_t max_change = 0, max_len = 0;
1446        int total_files = data->nr, count;
1447        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1448        const char *reset, *add_c, *del_c;
1449        const char *line_prefix = "";
1450        int extra_shown = 0;
1451        struct strbuf *msg = NULL;
1452
1453        if (data->nr == 0)
1454                return;
1455
1456        if (options->output_prefix) {
1457                msg = options->output_prefix(options, options->output_prefix_data);
1458                line_prefix = msg->buf;
1459        }
1460
1461        count = options->stat_count ? options->stat_count : data->nr;
1462
1463        reset = diff_get_color_opt(options, DIFF_RESET);
1464        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1465        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1466
1467        /*
1468         * Find the longest filename and max number of changes
1469         */
1470        for (i = 0; (i < count) && (i < data->nr); i++) {
1471                struct diffstat_file *file = data->files[i];
1472                uintmax_t change = file->added + file->deleted;
1473                if (!data->files[i]->is_renamed &&
1474                         (change == 0)) {
1475                        count++; /* not shown == room for one more */
1476                        continue;
1477                }
1478                fill_print_name(file);
1479                len = strlen(file->print_name);
1480                if (max_len < len)
1481                        max_len = len;
1482
1483                if (file->is_unmerged) {
1484                        /* "Unmerged" is 8 characters */
1485                        bin_width = bin_width < 8 ? 8 : bin_width;
1486                        continue;
1487                }
1488                if (file->is_binary) {
1489                        /* "Bin XXX -> YYY bytes" */
1490                        int w = 14 + decimal_width(file->added)
1491                                + decimal_width(file->deleted);
1492                        bin_width = bin_width < w ? w : bin_width;
1493                        /* Display change counts aligned with "Bin" */
1494                        number_width = 3;
1495                        continue;
1496                }
1497
1498                if (max_change < change)
1499                        max_change = change;
1500        }
1501        count = i; /* min(count, data->nr) */
1502
1503        /*
1504         * We have width = stat_width or term_columns() columns total.
1505         * We want a maximum of min(max_len, stat_name_width) for the name part.
1506         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1507         * We also need 1 for " " and 4 + decimal_width(max_change)
1508         * for " | NNNN " and one the empty column at the end, altogether
1509         * 6 + decimal_width(max_change).
1510         *
1511         * If there's not enough space, we will use the smaller of
1512         * stat_name_width (if set) and 5/8*width for the filename,
1513         * and the rest for constant elements + graph part, but no more
1514         * than stat_graph_width for the graph part.
1515         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1516         * for the standard terminal size).
1517         *
1518         * In other words: stat_width limits the maximum width, and
1519         * stat_name_width fixes the maximum width of the filename,
1520         * and is also used to divide available columns if there
1521         * aren't enough.
1522         *
1523         * Binary files are displayed with "Bin XXX -> YYY bytes"
1524         * instead of the change count and graph. This part is treated
1525         * similarly to the graph part, except that it is not
1526         * "scaled". If total width is too small to accomodate the
1527         * guaranteed minimum width of the filename part and the
1528         * separators and this message, this message will "overflow"
1529         * making the line longer than the maximum width.
1530         */
1531
1532        if (options->stat_width == -1)
1533                width = term_columns() - options->output_prefix_length;
1534        else
1535                width = options->stat_width ? options->stat_width : 80;
1536        number_width = decimal_width(max_change) > number_width ?
1537                decimal_width(max_change) : number_width;
1538
1539        if (options->stat_graph_width == -1)
1540                options->stat_graph_width = diff_stat_graph_width;
1541
1542        /*
1543         * Guarantee 3/8*16==6 for the graph part
1544         * and 5/8*16==10 for the filename part
1545         */
1546        if (width < 16 + 6 + number_width)
1547                width = 16 + 6 + number_width;
1548
1549        /*
1550         * First assign sizes that are wanted, ignoring available width.
1551         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1552         * starting from "XXX" should fit in graph_width.
1553         */
1554        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1555        if (options->stat_graph_width &&
1556            options->stat_graph_width < graph_width)
1557                graph_width = options->stat_graph_width;
1558
1559        name_width = (options->stat_name_width > 0 &&
1560                      options->stat_name_width < max_len) ?
1561                options->stat_name_width : max_len;
1562
1563        /*
1564         * Adjust adjustable widths not to exceed maximum width
1565         */
1566        if (name_width + number_width + 6 + graph_width > width) {
1567                if (graph_width > width * 3/8 - number_width - 6) {
1568                        graph_width = width * 3/8 - number_width - 6;
1569                        if (graph_width < 6)
1570                                graph_width = 6;
1571                }
1572
1573                if (options->stat_graph_width &&
1574                    graph_width > options->stat_graph_width)
1575                        graph_width = options->stat_graph_width;
1576                if (name_width > width - number_width - 6 - graph_width)
1577                        name_width = width - number_width - 6 - graph_width;
1578                else
1579                        graph_width = width - number_width - 6 - name_width;
1580        }
1581
1582        /*
1583         * From here name_width is the width of the name area,
1584         * and graph_width is the width of the graph area.
1585         * max_change is used to scale graph properly.
1586         */
1587        for (i = 0; i < count; i++) {
1588                const char *prefix = "";
1589                char *name = data->files[i]->print_name;
1590                uintmax_t added = data->files[i]->added;
1591                uintmax_t deleted = data->files[i]->deleted;
1592                int name_len;
1593
1594                if (!data->files[i]->is_renamed &&
1595                         (added + deleted == 0)) {
1596                        total_files--;
1597                        continue;
1598                }
1599                /*
1600                 * "scale" the filename
1601                 */
1602                len = name_width;
1603                name_len = strlen(name);
1604                if (name_width < name_len) {
1605                        char *slash;
1606                        prefix = "...";
1607                        len -= 3;
1608                        name += name_len - len;
1609                        slash = strchr(name, '/');
1610                        if (slash)
1611                                name = slash;
1612                }
1613
1614                if (data->files[i]->is_binary) {
1615                        fprintf(options->file, "%s", line_prefix);
1616                        show_name(options->file, prefix, name, len);
1617                        fprintf(options->file, " %*s", number_width, "Bin");
1618                        if (!added && !deleted) {
1619                                putc('\n', options->file);
1620                                continue;
1621                        }
1622                        fprintf(options->file, " %s%"PRIuMAX"%s",
1623                                del_c, deleted, reset);
1624                        fprintf(options->file, " -> ");
1625                        fprintf(options->file, "%s%"PRIuMAX"%s",
1626                                add_c, added, reset);
1627                        fprintf(options->file, " bytes");
1628                        fprintf(options->file, "\n");
1629                        continue;
1630                }
1631                else if (data->files[i]->is_unmerged) {
1632                        fprintf(options->file, "%s", line_prefix);
1633                        show_name(options->file, prefix, name, len);
1634                        fprintf(options->file, " Unmerged\n");
1635                        continue;
1636                }
1637
1638                /*
1639                 * scale the add/delete
1640                 */
1641                add = added;
1642                del = deleted;
1643                adds += add;
1644                dels += del;
1645
1646                if (graph_width <= max_change) {
1647                        int total = add + del;
1648
1649                        total = scale_linear(add + del, graph_width, max_change);
1650                        if (total < 2 && add && del)
1651                                /* width >= 2 due to the sanity check */
1652                                total = 2;
1653                        if (add < del) {
1654                                add = scale_linear(add, graph_width, max_change);
1655                                del = total - add;
1656                        } else {
1657                                del = scale_linear(del, graph_width, max_change);
1658                                add = total - del;
1659                        }
1660                }
1661                fprintf(options->file, "%s", line_prefix);
1662                show_name(options->file, prefix, name, len);
1663                fprintf(options->file, " %*"PRIuMAX"%s",
1664                        number_width, added + deleted,
1665                        added + deleted ? " " : "");
1666                show_graph(options->file, '+', add, add_c, reset);
1667                show_graph(options->file, '-', del, del_c, reset);
1668                fprintf(options->file, "\n");
1669        }
1670        for (i = count; i < data->nr; i++) {
1671                uintmax_t added = data->files[i]->added;
1672                uintmax_t deleted = data->files[i]->deleted;
1673                if (!data->files[i]->is_renamed &&
1674                         (added + deleted == 0)) {
1675                        total_files--;
1676                        continue;
1677                }
1678                adds += added;
1679                dels += deleted;
1680                if (!extra_shown)
1681                        fprintf(options->file, "%s ...\n", line_prefix);
1682                extra_shown = 1;
1683        }
1684        fprintf(options->file, "%s", line_prefix);
1685        print_stat_summary(options->file, total_files, adds, dels);
1686}
1687
1688static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1689{
1690        int i, adds = 0, dels = 0, total_files = data->nr;
1691
1692        if (data->nr == 0)
1693                return;
1694
1695        for (i = 0; i < data->nr; i++) {
1696                int added = data->files[i]->added;
1697                int deleted= data->files[i]->deleted;
1698
1699                if (data->files[i]->is_unmerged)
1700                        continue;
1701                if (!data->files[i]->is_renamed && (added + deleted == 0)) {
1702                        total_files--;
1703                } else {
1704                        adds += added;
1705                        dels += deleted;
1706                }
1707        }
1708        if (options->output_prefix) {
1709                struct strbuf *msg = NULL;
1710                msg = options->output_prefix(options,
1711                                options->output_prefix_data);
1712                fprintf(options->file, "%s", msg->buf);
1713        }
1714        print_stat_summary(options->file, total_files, adds, dels);
1715}
1716
1717static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1718{
1719        int i;
1720
1721        if (data->nr == 0)
1722                return;
1723
1724        for (i = 0; i < data->nr; i++) {
1725                struct diffstat_file *file = data->files[i];
1726
1727                if (options->output_prefix) {
1728                        struct strbuf *msg = NULL;
1729                        msg = options->output_prefix(options,
1730                                        options->output_prefix_data);
1731                        fprintf(options->file, "%s", msg->buf);
1732                }
1733
1734                if (file->is_binary)
1735                        fprintf(options->file, "-\t-\t");
1736                else
1737                        fprintf(options->file,
1738                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1739                                file->added, file->deleted);
1740                if (options->line_termination) {
1741                        fill_print_name(file);
1742                        if (!file->is_renamed)
1743                                write_name_quoted(file->name, options->file,
1744                                                  options->line_termination);
1745                        else {
1746                                fputs(file->print_name, options->file);
1747                                putc(options->line_termination, options->file);
1748                        }
1749                } else {
1750                        if (file->is_renamed) {
1751                                putc('\0', options->file);
1752                                write_name_quoted(file->from_name, options->file, '\0');
1753                        }
1754                        write_name_quoted(file->name, options->file, '\0');
1755                }
1756        }
1757}
1758
1759struct dirstat_file {
1760        const char *name;
1761        unsigned long changed;
1762};
1763
1764struct dirstat_dir {
1765        struct dirstat_file *files;
1766        int alloc, nr, permille, cumulative;
1767};
1768
1769static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1770                unsigned long changed, const char *base, int baselen)
1771{
1772        unsigned long this_dir = 0;
1773        unsigned int sources = 0;
1774        const char *line_prefix = "";
1775        struct strbuf *msg = NULL;
1776
1777        if (opt->output_prefix) {
1778                msg = opt->output_prefix(opt, opt->output_prefix_data);
1779                line_prefix = msg->buf;
1780        }
1781
1782        while (dir->nr) {
1783                struct dirstat_file *f = dir->files;
1784                int namelen = strlen(f->name);
1785                unsigned long this;
1786                char *slash;
1787
1788                if (namelen < baselen)
1789                        break;
1790                if (memcmp(f->name, base, baselen))
1791                        break;
1792                slash = strchr(f->name + baselen, '/');
1793                if (slash) {
1794                        int newbaselen = slash + 1 - f->name;
1795                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1796                        sources++;
1797                } else {
1798                        this = f->changed;
1799                        dir->files++;
1800                        dir->nr--;
1801                        sources += 2;
1802                }
1803                this_dir += this;
1804        }
1805
1806        /*
1807         * We don't report dirstat's for
1808         *  - the top level
1809         *  - or cases where everything came from a single directory
1810         *    under this directory (sources == 1).
1811         */
1812        if (baselen && sources != 1) {
1813                if (this_dir) {
1814                        int permille = this_dir * 1000 / changed;
1815                        if (permille >= dir->permille) {
1816                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1817                                        permille / 10, permille % 10, baselen, base);
1818                                if (!dir->cumulative)
1819                                        return 0;
1820                        }
1821                }
1822        }
1823        return this_dir;
1824}
1825
1826static int dirstat_compare(const void *_a, const void *_b)
1827{
1828        const struct dirstat_file *a = _a;
1829        const struct dirstat_file *b = _b;
1830        return strcmp(a->name, b->name);
1831}
1832
1833static void show_dirstat(struct diff_options *options)
1834{
1835        int i;
1836        unsigned long changed;
1837        struct dirstat_dir dir;
1838        struct diff_queue_struct *q = &diff_queued_diff;
1839
1840        dir.files = NULL;
1841        dir.alloc = 0;
1842        dir.nr = 0;
1843        dir.permille = options->dirstat_permille;
1844        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1845
1846        changed = 0;
1847        for (i = 0; i < q->nr; i++) {
1848                struct diff_filepair *p = q->queue[i];
1849                const char *name;
1850                unsigned long copied, added, damage;
1851                int content_changed;
1852
1853                name = p->two->path ? p->two->path : p->one->path;
1854
1855                if (p->one->sha1_valid && p->two->sha1_valid)
1856                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1857                else
1858                        content_changed = 1;
1859
1860                if (!content_changed) {
1861                        /*
1862                         * The SHA1 has not changed, so pre-/post-content is
1863                         * identical. We can therefore skip looking at the
1864                         * file contents altogether.
1865                         */
1866                        damage = 0;
1867                        goto found_damage;
1868                }
1869
1870                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1871                        /*
1872                         * In --dirstat-by-file mode, we don't really need to
1873                         * look at the actual file contents at all.
1874                         * The fact that the SHA1 changed is enough for us to
1875                         * add this file to the list of results
1876                         * (with each file contributing equal damage).
1877                         */
1878                        damage = 1;
1879                        goto found_damage;
1880                }
1881
1882                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1883                        diff_populate_filespec(p->one, 0);
1884                        diff_populate_filespec(p->two, 0);
1885                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1886                                               &copied, &added);
1887                        diff_free_filespec_data(p->one);
1888                        diff_free_filespec_data(p->two);
1889                } else if (DIFF_FILE_VALID(p->one)) {
1890                        diff_populate_filespec(p->one, 1);
1891                        copied = added = 0;
1892                        diff_free_filespec_data(p->one);
1893                } else if (DIFF_FILE_VALID(p->two)) {
1894                        diff_populate_filespec(p->two, 1);
1895                        copied = 0;
1896                        added = p->two->size;
1897                        diff_free_filespec_data(p->two);
1898                } else
1899                        continue;
1900
1901                /*
1902                 * Original minus copied is the removed material,
1903                 * added is the new material.  They are both damages
1904                 * made to the preimage.
1905                 * If the resulting damage is zero, we know that
1906                 * diffcore_count_changes() considers the two entries to
1907                 * be identical, but since content_changed is true, we
1908                 * know that there must have been _some_ kind of change,
1909                 * so we force all entries to have damage > 0.
1910                 */
1911                damage = (p->one->size - copied) + added;
1912                if (!damage)
1913                        damage = 1;
1914
1915found_damage:
1916                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1917                dir.files[dir.nr].name = name;
1918                dir.files[dir.nr].changed = damage;
1919                changed += damage;
1920                dir.nr++;
1921        }
1922
1923        /* This can happen even with many files, if everything was renames */
1924        if (!changed)
1925                return;
1926
1927        /* Show all directories with more than x% of the changes */
1928        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1929        gather_dirstat(options, &dir, changed, "", 0);
1930}
1931
1932static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1933{
1934        int i;
1935        unsigned long changed;
1936        struct dirstat_dir dir;
1937
1938        if (data->nr == 0)
1939                return;
1940
1941        dir.files = NULL;
1942        dir.alloc = 0;
1943        dir.nr = 0;
1944        dir.permille = options->dirstat_permille;
1945        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1946
1947        changed = 0;
1948        for (i = 0; i < data->nr; i++) {
1949                struct diffstat_file *file = data->files[i];
1950                unsigned long damage = file->added + file->deleted;
1951                if (file->is_binary)
1952                        /*
1953                         * binary files counts bytes, not lines. Must find some
1954                         * way to normalize binary bytes vs. textual lines.
1955                         * The following heuristic assumes that there are 64
1956                         * bytes per "line".
1957                         * This is stupid and ugly, but very cheap...
1958                         */
1959                        damage = (damage + 63) / 64;
1960                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1961                dir.files[dir.nr].name = file->name;
1962                dir.files[dir.nr].changed = damage;
1963                changed += damage;
1964                dir.nr++;
1965        }
1966
1967        /* This can happen even with many files, if everything was renames */
1968        if (!changed)
1969                return;
1970
1971        /* Show all directories with more than x% of the changes */
1972        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1973        gather_dirstat(options, &dir, changed, "", 0);
1974}
1975
1976static void free_diffstat_info(struct diffstat_t *diffstat)
1977{
1978        int i;
1979        for (i = 0; i < diffstat->nr; i++) {
1980                struct diffstat_file *f = diffstat->files[i];
1981                if (f->name != f->print_name)
1982                        free(f->print_name);
1983                free(f->name);
1984                free(f->from_name);
1985                free(f);
1986        }
1987        free(diffstat->files);
1988}
1989
1990struct checkdiff_t {
1991        const char *filename;
1992        int lineno;
1993        int conflict_marker_size;
1994        struct diff_options *o;
1995        unsigned ws_rule;
1996        unsigned status;
1997};
1998
1999static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2000{
2001        char firstchar;
2002        int cnt;
2003
2004        if (len < marker_size + 1)
2005                return 0;
2006        firstchar = line[0];
2007        switch (firstchar) {
2008        case '=': case '>': case '<': case '|':
2009                break;
2010        default:
2011                return 0;
2012        }
2013        for (cnt = 1; cnt < marker_size; cnt++)
2014                if (line[cnt] != firstchar)
2015                        return 0;
2016        /* line[1] thru line[marker_size-1] are same as firstchar */
2017        if (len < marker_size + 1 || !isspace(line[marker_size]))
2018                return 0;
2019        return 1;
2020}
2021
2022static void checkdiff_consume(void *priv, char *line, unsigned long len)
2023{
2024        struct checkdiff_t *data = priv;
2025        int marker_size = data->conflict_marker_size;
2026        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2027        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2028        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2029        char *err;
2030        char *line_prefix = "";
2031        struct strbuf *msgbuf;
2032
2033        assert(data->o);
2034        if (data->o->output_prefix) {
2035                msgbuf = data->o->output_prefix(data->o,
2036                        data->o->output_prefix_data);
2037                line_prefix = msgbuf->buf;
2038        }
2039
2040        if (line[0] == '+') {
2041                unsigned bad;
2042                data->lineno++;
2043                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2044                        data->status |= 1;
2045                        fprintf(data->o->file,
2046                                "%s%s:%d: leftover conflict marker\n",
2047                                line_prefix, data->filename, data->lineno);
2048                }
2049                bad = ws_check(line + 1, len - 1, data->ws_rule);
2050                if (!bad)
2051                        return;
2052                data->status |= bad;
2053                err = whitespace_error_string(bad);
2054                fprintf(data->o->file, "%s%s:%d: %s.\n",
2055                        line_prefix, data->filename, data->lineno, err);
2056                free(err);
2057                emit_line(data->o, set, reset, line, 1);
2058                ws_check_emit(line + 1, len - 1, data->ws_rule,
2059                              data->o->file, set, reset, ws);
2060        } else if (line[0] == ' ') {
2061                data->lineno++;
2062        } else if (line[0] == '@') {
2063                char *plus = strchr(line, '+');
2064                if (plus)
2065                        data->lineno = strtol(plus, NULL, 10) - 1;
2066                else
2067                        die("invalid diff");
2068        }
2069}
2070
2071static unsigned char *deflate_it(char *data,
2072                                 unsigned long size,
2073                                 unsigned long *result_size)
2074{
2075        int bound;
2076        unsigned char *deflated;
2077        git_zstream stream;
2078
2079        memset(&stream, 0, sizeof(stream));
2080        git_deflate_init(&stream, zlib_compression_level);
2081        bound = git_deflate_bound(&stream, size);
2082        deflated = xmalloc(bound);
2083        stream.next_out = deflated;
2084        stream.avail_out = bound;
2085
2086        stream.next_in = (unsigned char *)data;
2087        stream.avail_in = size;
2088        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2089                ; /* nothing */
2090        git_deflate_end(&stream);
2091        *result_size = stream.total_out;
2092        return deflated;
2093}
2094
2095static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2096{
2097        void *cp;
2098        void *delta;
2099        void *deflated;
2100        void *data;
2101        unsigned long orig_size;
2102        unsigned long delta_size;
2103        unsigned long deflate_size;
2104        unsigned long data_size;
2105
2106        /* We could do deflated delta, or we could do just deflated two,
2107         * whichever is smaller.
2108         */
2109        delta = NULL;
2110        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2111        if (one->size && two->size) {
2112                delta = diff_delta(one->ptr, one->size,
2113                                   two->ptr, two->size,
2114                                   &delta_size, deflate_size);
2115                if (delta) {
2116                        void *to_free = delta;
2117                        orig_size = delta_size;
2118                        delta = deflate_it(delta, delta_size, &delta_size);
2119                        free(to_free);
2120                }
2121        }
2122
2123        if (delta && delta_size < deflate_size) {
2124                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2125                free(deflated);
2126                data = delta;
2127                data_size = delta_size;
2128        }
2129        else {
2130                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2131                free(delta);
2132                data = deflated;
2133                data_size = deflate_size;
2134        }
2135
2136        /* emit data encoded in base85 */
2137        cp = data;
2138        while (data_size) {
2139                int bytes = (52 < data_size) ? 52 : data_size;
2140                char line[70];
2141                data_size -= bytes;
2142                if (bytes <= 26)
2143                        line[0] = bytes + 'A' - 1;
2144                else
2145                        line[0] = bytes - 26 + 'a' - 1;
2146                encode_85(line + 1, cp, bytes);
2147                cp = (char *) cp + bytes;
2148                fprintf(file, "%s", prefix);
2149                fputs(line, file);
2150                fputc('\n', file);
2151        }
2152        fprintf(file, "%s\n", prefix);
2153        free(data);
2154}
2155
2156static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2157{
2158        fprintf(file, "%sGIT binary patch\n", prefix);
2159        emit_binary_diff_body(file, one, two, prefix);
2160        emit_binary_diff_body(file, two, one, prefix);
2161}
2162
2163int diff_filespec_is_binary(struct diff_filespec *one)
2164{
2165        if (one->is_binary == -1) {
2166                diff_filespec_load_driver(one);
2167                if (one->driver->binary != -1)
2168                        one->is_binary = one->driver->binary;
2169                else {
2170                        if (!one->data && DIFF_FILE_VALID(one))
2171                                diff_populate_filespec(one, 0);
2172                        if (one->data)
2173                                one->is_binary = buffer_is_binary(one->data,
2174                                                one->size);
2175                        if (one->is_binary == -1)
2176                                one->is_binary = 0;
2177                }
2178        }
2179        return one->is_binary;
2180}
2181
2182static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2183{
2184        diff_filespec_load_driver(one);
2185        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2186}
2187
2188void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2189{
2190        if (!options->a_prefix)
2191                options->a_prefix = a;
2192        if (!options->b_prefix)
2193                options->b_prefix = b;
2194}
2195
2196struct userdiff_driver *get_textconv(struct diff_filespec *one)
2197{
2198        if (!DIFF_FILE_VALID(one))
2199                return NULL;
2200
2201        diff_filespec_load_driver(one);
2202        return userdiff_get_textconv(one->driver);
2203}
2204
2205static void builtin_diff(const char *name_a,
2206                         const char *name_b,
2207                         struct diff_filespec *one,
2208                         struct diff_filespec *two,
2209                         const char *xfrm_msg,
2210                         int must_show_header,
2211                         struct diff_options *o,
2212                         int complete_rewrite)
2213{
2214        mmfile_t mf1, mf2;
2215        const char *lbl[2];
2216        char *a_one, *b_two;
2217        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2218        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2219        const char *a_prefix, *b_prefix;
2220        struct userdiff_driver *textconv_one = NULL;
2221        struct userdiff_driver *textconv_two = NULL;
2222        struct strbuf header = STRBUF_INIT;
2223        struct strbuf *msgbuf;
2224        char *line_prefix = "";
2225
2226        if (o->output_prefix) {
2227                msgbuf = o->output_prefix(o, o->output_prefix_data);
2228                line_prefix = msgbuf->buf;
2229        }
2230
2231        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2232                        (!one->mode || S_ISGITLINK(one->mode)) &&
2233                        (!two->mode || S_ISGITLINK(two->mode))) {
2234                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2235                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2236                show_submodule_summary(o->file, one ? one->path : two->path,
2237                                one->sha1, two->sha1, two->dirty_submodule,
2238                                del, add, reset);
2239                return;
2240        }
2241
2242        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2243                textconv_one = get_textconv(one);
2244                textconv_two = get_textconv(two);
2245        }
2246
2247        diff_set_mnemonic_prefix(o, "a/", "b/");
2248        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2249                a_prefix = o->b_prefix;
2250                b_prefix = o->a_prefix;
2251        } else {
2252                a_prefix = o->a_prefix;
2253                b_prefix = o->b_prefix;
2254        }
2255
2256        /* Never use a non-valid filename anywhere if at all possible */
2257        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2258        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2259
2260        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2261        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2262        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2263        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2264        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2265        if (lbl[0][0] == '/') {
2266                /* /dev/null */
2267                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2268                if (xfrm_msg)
2269                        strbuf_addstr(&header, xfrm_msg);
2270                must_show_header = 1;
2271        }
2272        else if (lbl[1][0] == '/') {
2273                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2274                if (xfrm_msg)
2275                        strbuf_addstr(&header, xfrm_msg);
2276                must_show_header = 1;
2277        }
2278        else {
2279                if (one->mode != two->mode) {
2280                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2281                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2282                        must_show_header = 1;
2283                }
2284                if (xfrm_msg)
2285                        strbuf_addstr(&header, xfrm_msg);
2286
2287                /*
2288                 * we do not run diff between different kind
2289                 * of objects.
2290                 */
2291                if ((one->mode ^ two->mode) & S_IFMT)
2292                        goto free_ab_and_return;
2293                if (complete_rewrite &&
2294                    (textconv_one || !diff_filespec_is_binary(one)) &&
2295                    (textconv_two || !diff_filespec_is_binary(two))) {
2296                        fprintf(o->file, "%s", header.buf);
2297                        strbuf_reset(&header);
2298                        emit_rewrite_diff(name_a, name_b, one, two,
2299                                                textconv_one, textconv_two, o);
2300                        o->found_changes = 1;
2301                        goto free_ab_and_return;
2302                }
2303        }
2304
2305        if (o->irreversible_delete && lbl[1][0] == '/') {
2306                fprintf(o->file, "%s", header.buf);
2307                strbuf_reset(&header);
2308                goto free_ab_and_return;
2309        } else if (!DIFF_OPT_TST(o, TEXT) &&
2310            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2311              (!textconv_two && diff_filespec_is_binary(two)) )) {
2312                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2313                        die("unable to read files to diff");
2314                /* Quite common confusing case */
2315                if (mf1.size == mf2.size &&
2316                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2317                        if (must_show_header)
2318                                fprintf(o->file, "%s", header.buf);
2319                        goto free_ab_and_return;
2320                }
2321                fprintf(o->file, "%s", header.buf);
2322                strbuf_reset(&header);
2323                if (DIFF_OPT_TST(o, BINARY))
2324                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2325                else
2326                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2327                                line_prefix, lbl[0], lbl[1]);
2328                o->found_changes = 1;
2329        } else {
2330                /* Crazy xdl interfaces.. */
2331                const char *diffopts = getenv("GIT_DIFF_OPTS");
2332                xpparam_t xpp;
2333                xdemitconf_t xecfg;
2334                struct emit_callback ecbdata;
2335                const struct userdiff_funcname *pe;
2336
2337                if (must_show_header) {
2338                        fprintf(o->file, "%s", header.buf);
2339                        strbuf_reset(&header);
2340                }
2341
2342                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2343                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2344
2345                pe = diff_funcname_pattern(one);
2346                if (!pe)
2347                        pe = diff_funcname_pattern(two);
2348
2349                memset(&xpp, 0, sizeof(xpp));
2350                memset(&xecfg, 0, sizeof(xecfg));
2351                memset(&ecbdata, 0, sizeof(ecbdata));
2352                ecbdata.label_path = lbl;
2353                ecbdata.color_diff = want_color(o->use_color);
2354                ecbdata.found_changesp = &o->found_changes;
2355                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2356                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2357                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2358                ecbdata.opt = o;
2359                ecbdata.header = header.len ? &header : NULL;
2360                xpp.flags = o->xdl_opts;
2361                xecfg.ctxlen = o->context;
2362                xecfg.interhunkctxlen = o->interhunkcontext;
2363                xecfg.flags = XDL_EMIT_FUNCNAMES;
2364                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2365                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2366                if (pe)
2367                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2368                if (!diffopts)
2369                        ;
2370                else if (!prefixcmp(diffopts, "--unified="))
2371                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2372                else if (!prefixcmp(diffopts, "-u"))
2373                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2374                if (o->word_diff)
2375                        init_diff_words_data(&ecbdata, o, one, two);
2376                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2377                              &xpp, &xecfg);
2378                if (o->word_diff)
2379                        free_diff_words_data(&ecbdata);
2380                if (textconv_one)
2381                        free(mf1.ptr);
2382                if (textconv_two)
2383                        free(mf2.ptr);
2384                xdiff_clear_find_func(&xecfg);
2385        }
2386
2387 free_ab_and_return:
2388        strbuf_release(&header);
2389        diff_free_filespec_data(one);
2390        diff_free_filespec_data(two);
2391        free(a_one);
2392        free(b_two);
2393        return;
2394}
2395
2396static void builtin_diffstat(const char *name_a, const char *name_b,
2397                             struct diff_filespec *one,
2398                             struct diff_filespec *two,
2399                             struct diffstat_t *diffstat,
2400                             struct diff_options *o,
2401                             int complete_rewrite)
2402{
2403        mmfile_t mf1, mf2;
2404        struct diffstat_file *data;
2405        int same_contents;
2406
2407        data = diffstat_add(diffstat, name_a, name_b);
2408
2409        if (!one || !two) {
2410                data->is_unmerged = 1;
2411                return;
2412        }
2413
2414        same_contents = !hashcmp(one->sha1, two->sha1);
2415
2416        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2417                data->is_binary = 1;
2418                if (same_contents) {
2419                        data->added = 0;
2420                        data->deleted = 0;
2421                } else {
2422                        data->added = diff_filespec_size(two);
2423                        data->deleted = diff_filespec_size(one);
2424                }
2425        }
2426
2427        else if (complete_rewrite) {
2428                diff_populate_filespec(one, 0);
2429                diff_populate_filespec(two, 0);
2430                data->deleted = count_lines(one->data, one->size);
2431                data->added = count_lines(two->data, two->size);
2432        }
2433
2434        else if (!same_contents) {
2435                /* Crazy xdl interfaces.. */
2436                xpparam_t xpp;
2437                xdemitconf_t xecfg;
2438
2439                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2440                        die("unable to read files to diff");
2441
2442                memset(&xpp, 0, sizeof(xpp));
2443                memset(&xecfg, 0, sizeof(xecfg));
2444                xpp.flags = o->xdl_opts;
2445                xecfg.ctxlen = o->context;
2446                xecfg.interhunkctxlen = o->interhunkcontext;
2447                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2448                              &xpp, &xecfg);
2449        }
2450
2451        diff_free_filespec_data(one);
2452        diff_free_filespec_data(two);
2453}
2454
2455static void builtin_checkdiff(const char *name_a, const char *name_b,
2456                              const char *attr_path,
2457                              struct diff_filespec *one,
2458                              struct diff_filespec *two,
2459                              struct diff_options *o)
2460{
2461        mmfile_t mf1, mf2;
2462        struct checkdiff_t data;
2463
2464        if (!two)
2465                return;
2466
2467        memset(&data, 0, sizeof(data));
2468        data.filename = name_b ? name_b : name_a;
2469        data.lineno = 0;
2470        data.o = o;
2471        data.ws_rule = whitespace_rule(attr_path);
2472        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2473
2474        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2475                die("unable to read files to diff");
2476
2477        /*
2478         * All the other codepaths check both sides, but not checking
2479         * the "old" side here is deliberate.  We are checking the newly
2480         * introduced changes, and as long as the "new" side is text, we
2481         * can and should check what it introduces.
2482         */
2483        if (diff_filespec_is_binary(two))
2484                goto free_and_return;
2485        else {
2486                /* Crazy xdl interfaces.. */
2487                xpparam_t xpp;
2488                xdemitconf_t xecfg;
2489
2490                memset(&xpp, 0, sizeof(xpp));
2491                memset(&xecfg, 0, sizeof(xecfg));
2492                xecfg.ctxlen = 1; /* at least one context line */
2493                xpp.flags = 0;
2494                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2495                              &xpp, &xecfg);
2496
2497                if (data.ws_rule & WS_BLANK_AT_EOF) {
2498                        struct emit_callback ecbdata;
2499                        int blank_at_eof;
2500
2501                        ecbdata.ws_rule = data.ws_rule;
2502                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2503                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2504
2505                        if (blank_at_eof) {
2506                                static char *err;
2507                                if (!err)
2508                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2509                                fprintf(o->file, "%s:%d: %s.\n",
2510                                        data.filename, blank_at_eof, err);
2511                                data.status = 1; /* report errors */
2512                        }
2513                }
2514        }
2515 free_and_return:
2516        diff_free_filespec_data(one);
2517        diff_free_filespec_data(two);
2518        if (data.status)
2519                DIFF_OPT_SET(o, CHECK_FAILED);
2520}
2521
2522struct diff_filespec *alloc_filespec(const char *path)
2523{
2524        int namelen = strlen(path);
2525        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2526
2527        memset(spec, 0, sizeof(*spec));
2528        spec->path = (char *)(spec + 1);
2529        memcpy(spec->path, path, namelen+1);
2530        spec->count = 1;
2531        spec->is_binary = -1;
2532        return spec;
2533}
2534
2535void free_filespec(struct diff_filespec *spec)
2536{
2537        if (!--spec->count) {
2538                diff_free_filespec_data(spec);
2539                free(spec);
2540        }
2541}
2542
2543void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2544                   unsigned short mode)
2545{
2546        if (mode) {
2547                spec->mode = canon_mode(mode);
2548                hashcpy(spec->sha1, sha1);
2549                spec->sha1_valid = !is_null_sha1(sha1);
2550        }
2551}
2552
2553/*
2554 * Given a name and sha1 pair, if the index tells us the file in
2555 * the work tree has that object contents, return true, so that
2556 * prepare_temp_file() does not have to inflate and extract.
2557 */
2558static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2559{
2560        struct cache_entry *ce;
2561        struct stat st;
2562        int pos, len;
2563
2564        /*
2565         * We do not read the cache ourselves here, because the
2566         * benchmark with my previous version that always reads cache
2567         * shows that it makes things worse for diff-tree comparing
2568         * two linux-2.6 kernel trees in an already checked out work
2569         * tree.  This is because most diff-tree comparisons deal with
2570         * only a small number of files, while reading the cache is
2571         * expensive for a large project, and its cost outweighs the
2572         * savings we get by not inflating the object to a temporary
2573         * file.  Practically, this code only helps when we are used
2574         * by diff-cache --cached, which does read the cache before
2575         * calling us.
2576         */
2577        if (!active_cache)
2578                return 0;
2579
2580        /* We want to avoid the working directory if our caller
2581         * doesn't need the data in a normal file, this system
2582         * is rather slow with its stat/open/mmap/close syscalls,
2583         * and the object is contained in a pack file.  The pack
2584         * is probably already open and will be faster to obtain
2585         * the data through than the working directory.  Loose
2586         * objects however would tend to be slower as they need
2587         * to be individually opened and inflated.
2588         */
2589        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2590                return 0;
2591
2592        len = strlen(name);
2593        pos = cache_name_pos(name, len);
2594        if (pos < 0)
2595                return 0;
2596        ce = active_cache[pos];
2597
2598        /*
2599         * This is not the sha1 we are looking for, or
2600         * unreusable because it is not a regular file.
2601         */
2602        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2603                return 0;
2604
2605        /*
2606         * If ce is marked as "assume unchanged", there is no
2607         * guarantee that work tree matches what we are looking for.
2608         */
2609        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2610                return 0;
2611
2612        /*
2613         * If ce matches the file in the work tree, we can reuse it.
2614         */
2615        if (ce_uptodate(ce) ||
2616            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2617                return 1;
2618
2619        return 0;
2620}
2621
2622static int populate_from_stdin(struct diff_filespec *s)
2623{
2624        struct strbuf buf = STRBUF_INIT;
2625        size_t size = 0;
2626
2627        if (strbuf_read(&buf, 0, 0) < 0)
2628                return error("error while reading from stdin %s",
2629                                     strerror(errno));
2630
2631        s->should_munmap = 0;
2632        s->data = strbuf_detach(&buf, &size);
2633        s->size = size;
2634        s->should_free = 1;
2635        return 0;
2636}
2637
2638static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2639{
2640        int len;
2641        char *data = xmalloc(100), *dirty = "";
2642
2643        /* Are we looking at the work tree? */
2644        if (s->dirty_submodule)
2645                dirty = "-dirty";
2646
2647        len = snprintf(data, 100,
2648                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2649        s->data = data;
2650        s->size = len;
2651        s->should_free = 1;
2652        if (size_only) {
2653                s->data = NULL;
2654                free(data);
2655        }
2656        return 0;
2657}
2658
2659/*
2660 * While doing rename detection and pickaxe operation, we may need to
2661 * grab the data for the blob (or file) for our own in-core comparison.
2662 * diff_filespec has data and size fields for this purpose.
2663 */
2664int diff_populate_filespec(struct diff_filespec *s, int size_only)
2665{
2666        int err = 0;
2667        if (!DIFF_FILE_VALID(s))
2668                die("internal error: asking to populate invalid file.");
2669        if (S_ISDIR(s->mode))
2670                return -1;
2671
2672        if (s->data)
2673                return 0;
2674
2675        if (size_only && 0 < s->size)
2676                return 0;
2677
2678        if (S_ISGITLINK(s->mode))
2679                return diff_populate_gitlink(s, size_only);
2680
2681        if (!s->sha1_valid ||
2682            reuse_worktree_file(s->path, s->sha1, 0)) {
2683                struct strbuf buf = STRBUF_INIT;
2684                struct stat st;
2685                int fd;
2686
2687                if (!strcmp(s->path, "-"))
2688                        return populate_from_stdin(s);
2689
2690                if (lstat(s->path, &st) < 0) {
2691                        if (errno == ENOENT) {
2692                        err_empty:
2693                                err = -1;
2694                        empty:
2695                                s->data = (char *)"";
2696                                s->size = 0;
2697                                return err;
2698                        }
2699                }
2700                s->size = xsize_t(st.st_size);
2701                if (!s->size)
2702                        goto empty;
2703                if (S_ISLNK(st.st_mode)) {
2704                        struct strbuf sb = STRBUF_INIT;
2705
2706                        if (strbuf_readlink(&sb, s->path, s->size))
2707                                goto err_empty;
2708                        s->size = sb.len;
2709                        s->data = strbuf_detach(&sb, NULL);
2710                        s->should_free = 1;
2711                        return 0;
2712                }
2713                if (size_only)
2714                        return 0;
2715                fd = open(s->path, O_RDONLY);
2716                if (fd < 0)
2717                        goto err_empty;
2718                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2719                close(fd);
2720                s->should_munmap = 1;
2721
2722                /*
2723                 * Convert from working tree format to canonical git format
2724                 */
2725                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2726                        size_t size = 0;
2727                        munmap(s->data, s->size);
2728                        s->should_munmap = 0;
2729                        s->data = strbuf_detach(&buf, &size);
2730                        s->size = size;
2731                        s->should_free = 1;
2732                }
2733        }
2734        else {
2735                enum object_type type;
2736                if (size_only) {
2737                        type = sha1_object_info(s->sha1, &s->size);
2738                        if (type < 0)
2739                                die("unable to read %s", sha1_to_hex(s->sha1));
2740                } else {
2741                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2742                        if (!s->data)
2743                                die("unable to read %s", sha1_to_hex(s->sha1));
2744                        s->should_free = 1;
2745                }
2746        }
2747        return 0;
2748}
2749
2750void diff_free_filespec_blob(struct diff_filespec *s)
2751{
2752        if (s->should_free)
2753                free(s->data);
2754        else if (s->should_munmap)
2755                munmap(s->data, s->size);
2756
2757        if (s->should_free || s->should_munmap) {
2758                s->should_free = s->should_munmap = 0;
2759                s->data = NULL;
2760        }
2761}
2762
2763void diff_free_filespec_data(struct diff_filespec *s)
2764{
2765        diff_free_filespec_blob(s);
2766        free(s->cnt_data);
2767        s->cnt_data = NULL;
2768}
2769
2770static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2771                           void *blob,
2772                           unsigned long size,
2773                           const unsigned char *sha1,
2774                           int mode)
2775{
2776        int fd;
2777        struct strbuf buf = STRBUF_INIT;
2778        struct strbuf template = STRBUF_INIT;
2779        char *path_dup = xstrdup(path);
2780        const char *base = basename(path_dup);
2781
2782        /* Generate "XXXXXX_basename.ext" */
2783        strbuf_addstr(&template, "XXXXXX_");
2784        strbuf_addstr(&template, base);
2785
2786        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2787                        strlen(base) + 1);
2788        if (fd < 0)
2789                die_errno("unable to create temp-file");
2790        if (convert_to_working_tree(path,
2791                        (const char *)blob, (size_t)size, &buf)) {
2792                blob = buf.buf;
2793                size = buf.len;
2794        }
2795        if (write_in_full(fd, blob, size) != size)
2796                die_errno("unable to write temp-file");
2797        close(fd);
2798        temp->name = temp->tmp_path;
2799        strcpy(temp->hex, sha1_to_hex(sha1));
2800        temp->hex[40] = 0;
2801        sprintf(temp->mode, "%06o", mode);
2802        strbuf_release(&buf);
2803        strbuf_release(&template);
2804        free(path_dup);
2805}
2806
2807static struct diff_tempfile *prepare_temp_file(const char *name,
2808                struct diff_filespec *one)
2809{
2810        struct diff_tempfile *temp = claim_diff_tempfile();
2811
2812        if (!DIFF_FILE_VALID(one)) {
2813        not_a_valid_file:
2814                /* A '-' entry produces this for file-2, and
2815                 * a '+' entry produces this for file-1.
2816                 */
2817                temp->name = "/dev/null";
2818                strcpy(temp->hex, ".");
2819                strcpy(temp->mode, ".");
2820                return temp;
2821        }
2822
2823        if (!remove_tempfile_installed) {
2824                atexit(remove_tempfile);
2825                sigchain_push_common(remove_tempfile_on_signal);
2826                remove_tempfile_installed = 1;
2827        }
2828
2829        if (!one->sha1_valid ||
2830            reuse_worktree_file(name, one->sha1, 1)) {
2831                struct stat st;
2832                if (lstat(name, &st) < 0) {
2833                        if (errno == ENOENT)
2834                                goto not_a_valid_file;
2835                        die_errno("stat(%s)", name);
2836                }
2837                if (S_ISLNK(st.st_mode)) {
2838                        struct strbuf sb = STRBUF_INIT;
2839                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2840                                die_errno("readlink(%s)", name);
2841                        prep_temp_blob(name, temp, sb.buf, sb.len,
2842                                       (one->sha1_valid ?
2843                                        one->sha1 : null_sha1),
2844                                       (one->sha1_valid ?
2845                                        one->mode : S_IFLNK));
2846                        strbuf_release(&sb);
2847                }
2848                else {
2849                        /* we can borrow from the file in the work tree */
2850                        temp->name = name;
2851                        if (!one->sha1_valid)
2852                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2853                        else
2854                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2855                        /* Even though we may sometimes borrow the
2856                         * contents from the work tree, we always want
2857                         * one->mode.  mode is trustworthy even when
2858                         * !(one->sha1_valid), as long as
2859                         * DIFF_FILE_VALID(one).
2860                         */
2861                        sprintf(temp->mode, "%06o", one->mode);
2862                }
2863                return temp;
2864        }
2865        else {
2866                if (diff_populate_filespec(one, 0))
2867                        die("cannot read data blob for %s", one->path);
2868                prep_temp_blob(name, temp, one->data, one->size,
2869                               one->sha1, one->mode);
2870        }
2871        return temp;
2872}
2873
2874/* An external diff command takes:
2875 *
2876 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2877 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2878 *
2879 */
2880static void run_external_diff(const char *pgm,
2881                              const char *name,
2882                              const char *other,
2883                              struct diff_filespec *one,
2884                              struct diff_filespec *two,
2885                              const char *xfrm_msg,
2886                              int complete_rewrite)
2887{
2888        const char *spawn_arg[10];
2889        int retval;
2890        const char **arg = &spawn_arg[0];
2891
2892        if (one && two) {
2893                struct diff_tempfile *temp_one, *temp_two;
2894                const char *othername = (other ? other : name);
2895                temp_one = prepare_temp_file(name, one);
2896                temp_two = prepare_temp_file(othername, two);
2897                *arg++ = pgm;
2898                *arg++ = name;
2899                *arg++ = temp_one->name;
2900                *arg++ = temp_one->hex;
2901                *arg++ = temp_one->mode;
2902                *arg++ = temp_two->name;
2903                *arg++ = temp_two->hex;
2904                *arg++ = temp_two->mode;
2905                if (other) {
2906                        *arg++ = other;
2907                        *arg++ = xfrm_msg;
2908                }
2909        } else {
2910                *arg++ = pgm;
2911                *arg++ = name;
2912        }
2913        *arg = NULL;
2914        fflush(NULL);
2915        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2916        remove_tempfile();
2917        if (retval) {
2918                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2919                exit(1);
2920        }
2921}
2922
2923static int similarity_index(struct diff_filepair *p)
2924{
2925        return p->score * 100 / MAX_SCORE;
2926}
2927
2928static void fill_metainfo(struct strbuf *msg,
2929                          const char *name,
2930                          const char *other,
2931                          struct diff_filespec *one,
2932                          struct diff_filespec *two,
2933                          struct diff_options *o,
2934                          struct diff_filepair *p,
2935                          int *must_show_header,
2936                          int use_color)
2937{
2938        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2939        const char *reset = diff_get_color(use_color, DIFF_RESET);
2940        struct strbuf *msgbuf;
2941        char *line_prefix = "";
2942
2943        *must_show_header = 1;
2944        if (o->output_prefix) {
2945                msgbuf = o->output_prefix(o, o->output_prefix_data);
2946                line_prefix = msgbuf->buf;
2947        }
2948        strbuf_init(msg, PATH_MAX * 2 + 300);
2949        switch (p->status) {
2950        case DIFF_STATUS_COPIED:
2951                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2952                            line_prefix, set, similarity_index(p));
2953                strbuf_addf(msg, "%s\n%s%scopy from ",
2954                            reset,  line_prefix, set);
2955                quote_c_style(name, msg, NULL, 0);
2956                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2957                quote_c_style(other, msg, NULL, 0);
2958                strbuf_addf(msg, "%s\n", reset);
2959                break;
2960        case DIFF_STATUS_RENAMED:
2961                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2962                            line_prefix, set, similarity_index(p));
2963                strbuf_addf(msg, "%s\n%s%srename from ",
2964                            reset, line_prefix, set);
2965                quote_c_style(name, msg, NULL, 0);
2966                strbuf_addf(msg, "%s\n%s%srename to ",
2967                            reset, line_prefix, set);
2968                quote_c_style(other, msg, NULL, 0);
2969                strbuf_addf(msg, "%s\n", reset);
2970                break;
2971        case DIFF_STATUS_MODIFIED:
2972                if (p->score) {
2973                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2974                                    line_prefix,
2975                                    set, similarity_index(p), reset);
2976                        break;
2977                }
2978                /* fallthru */
2979        default:
2980                *must_show_header = 0;
2981        }
2982        if (one && two && hashcmp(one->sha1, two->sha1)) {
2983                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2984
2985                if (DIFF_OPT_TST(o, BINARY)) {
2986                        mmfile_t mf;
2987                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2988                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2989                                abbrev = 40;
2990                }
2991                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2992                            find_unique_abbrev(one->sha1, abbrev));
2993                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2994                if (one->mode == two->mode)
2995                        strbuf_addf(msg, " %06o", one->mode);
2996                strbuf_addf(msg, "%s\n", reset);
2997        }
2998}
2999
3000static void run_diff_cmd(const char *pgm,
3001                         const char *name,
3002                         const char *other,
3003                         const char *attr_path,
3004                         struct diff_filespec *one,
3005                         struct diff_filespec *two,
3006                         struct strbuf *msg,
3007                         struct diff_options *o,
3008                         struct diff_filepair *p)
3009{
3010        const char *xfrm_msg = NULL;
3011        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3012        int must_show_header = 0;
3013
3014        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3015                pgm = NULL;
3016        else {
3017                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3018                if (drv && drv->external)
3019                        pgm = drv->external;
3020        }
3021
3022        if (msg) {
3023                /*
3024                 * don't use colors when the header is intended for an
3025                 * external diff driver
3026                 */
3027                fill_metainfo(msg, name, other, one, two, o, p,
3028                              &must_show_header,
3029                              want_color(o->use_color) && !pgm);
3030                xfrm_msg = msg->len ? msg->buf : NULL;
3031        }
3032
3033        if (pgm) {
3034                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3035                                  complete_rewrite);
3036                return;
3037        }
3038        if (one && two)
3039                builtin_diff(name, other ? other : name,
3040                             one, two, xfrm_msg, must_show_header,
3041                             o, complete_rewrite);
3042        else
3043                fprintf(o->file, "* Unmerged path %s\n", name);
3044}
3045
3046static void diff_fill_sha1_info(struct diff_filespec *one)
3047{
3048        if (DIFF_FILE_VALID(one)) {
3049                if (!one->sha1_valid) {
3050                        struct stat st;
3051                        if (!strcmp(one->path, "-")) {
3052                                hashcpy(one->sha1, null_sha1);
3053                                return;
3054                        }
3055                        if (lstat(one->path, &st) < 0)
3056                                die_errno("stat '%s'", one->path);
3057                        if (index_path(one->sha1, one->path, &st, 0))
3058                                die("cannot hash %s", one->path);
3059                }
3060        }
3061        else
3062                hashclr(one->sha1);
3063}
3064
3065static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3066{
3067        /* Strip the prefix but do not molest /dev/null and absolute paths */
3068        if (*namep && **namep != '/') {
3069                *namep += prefix_length;
3070                if (**namep == '/')
3071                        ++*namep;
3072        }
3073        if (*otherp && **otherp != '/') {
3074                *otherp += prefix_length;
3075                if (**otherp == '/')
3076                        ++*otherp;
3077        }
3078}
3079
3080static void run_diff(struct diff_filepair *p, struct diff_options *o)
3081{
3082        const char *pgm = external_diff();
3083        struct strbuf msg;
3084        struct diff_filespec *one = p->one;
3085        struct diff_filespec *two = p->two;
3086        const char *name;
3087        const char *other;
3088        const char *attr_path;
3089
3090        name  = p->one->path;
3091        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3092        attr_path = name;
3093        if (o->prefix_length)
3094                strip_prefix(o->prefix_length, &name, &other);
3095
3096        if (DIFF_PAIR_UNMERGED(p)) {
3097                run_diff_cmd(pgm, name, NULL, attr_path,
3098                             NULL, NULL, NULL, o, p);
3099                return;
3100        }
3101
3102        diff_fill_sha1_info(one);
3103        diff_fill_sha1_info(two);
3104
3105        if (!pgm &&
3106            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3107            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3108                /*
3109                 * a filepair that changes between file and symlink
3110                 * needs to be split into deletion and creation.
3111                 */
3112                struct diff_filespec *null = alloc_filespec(two->path);
3113                run_diff_cmd(NULL, name, other, attr_path,
3114                             one, null, &msg, o, p);
3115                free(null);
3116                strbuf_release(&msg);
3117
3118                null = alloc_filespec(one->path);
3119                run_diff_cmd(NULL, name, other, attr_path,
3120                             null, two, &msg, o, p);
3121                free(null);
3122        }
3123        else
3124                run_diff_cmd(pgm, name, other, attr_path,
3125                             one, two, &msg, o, p);
3126
3127        strbuf_release(&msg);
3128}
3129
3130static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3131                         struct diffstat_t *diffstat)
3132{
3133        const char *name;
3134        const char *other;
3135        int complete_rewrite = 0;
3136
3137        if (DIFF_PAIR_UNMERGED(p)) {
3138                /* unmerged */
3139                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
3140                return;
3141        }
3142
3143        name = p->one->path;
3144        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3145
3146        if (o->prefix_length)
3147                strip_prefix(o->prefix_length, &name, &other);
3148
3149        diff_fill_sha1_info(p->one);
3150        diff_fill_sha1_info(p->two);
3151
3152        if (p->status == DIFF_STATUS_MODIFIED && p->score)
3153                complete_rewrite = 1;
3154        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
3155}
3156
3157static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3158{
3159        const char *name;
3160        const char *other;
3161        const char *attr_path;
3162
3163        if (DIFF_PAIR_UNMERGED(p)) {
3164                /* unmerged */
3165                return;
3166        }
3167
3168        name = p->one->path;
3169        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3170        attr_path = other ? other : name;
3171
3172        if (o->prefix_length)
3173                strip_prefix(o->prefix_length, &name, &other);
3174
3175        diff_fill_sha1_info(p->one);
3176        diff_fill_sha1_info(p->two);
3177
3178        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3179}
3180
3181void diff_setup(struct diff_options *options)
3182{
3183        memcpy(options, &default_diff_options, sizeof(*options));
3184
3185        options->file = stdout;
3186
3187        options->line_termination = '\n';
3188        options->break_opt = -1;
3189        options->rename_limit = -1;
3190        options->dirstat_permille = diff_dirstat_permille_default;
3191        options->context = 3;
3192        DIFF_OPT_SET(options, RENAME_EMPTY);
3193
3194        options->change = diff_change;
3195        options->add_remove = diff_addremove;
3196        options->use_color = diff_use_color_default;
3197        options->detect_rename = diff_detect_rename_default;
3198
3199        if (diff_no_prefix) {
3200                options->a_prefix = options->b_prefix = "";
3201        } else if (!diff_mnemonic_prefix) {
3202                options->a_prefix = "a/";
3203                options->b_prefix = "b/";
3204        }
3205}
3206
3207int diff_setup_done(struct diff_options *options)
3208{
3209        int count = 0;
3210
3211        if (options->output_format & DIFF_FORMAT_NAME)
3212                count++;
3213        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3214                count++;
3215        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3216                count++;
3217        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3218                count++;
3219        if (count > 1)
3220                die("--name-only, --name-status, --check and -s are mutually exclusive");
3221
3222        /*
3223         * Most of the time we can say "there are changes"
3224         * only by checking if there are changed paths, but
3225         * --ignore-whitespace* options force us to look
3226         * inside contents.
3227         */
3228
3229        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3230            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3231            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3232                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3233        else
3234                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3235
3236        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3237                options->detect_rename = DIFF_DETECT_COPY;
3238
3239        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3240                options->prefix = NULL;
3241        if (options->prefix)
3242                options->prefix_length = strlen(options->prefix);
3243        else
3244                options->prefix_length = 0;
3245
3246        if (options->output_format & (DIFF_FORMAT_NAME |
3247                                      DIFF_FORMAT_NAME_STATUS |
3248                                      DIFF_FORMAT_CHECKDIFF |
3249                                      DIFF_FORMAT_NO_OUTPUT))
3250                options->output_format &= ~(DIFF_FORMAT_RAW |
3251                                            DIFF_FORMAT_NUMSTAT |
3252                                            DIFF_FORMAT_DIFFSTAT |
3253                                            DIFF_FORMAT_SHORTSTAT |
3254                                            DIFF_FORMAT_DIRSTAT |
3255                                            DIFF_FORMAT_SUMMARY |
3256                                            DIFF_FORMAT_PATCH);
3257
3258        /*
3259         * These cases always need recursive; we do not drop caller-supplied
3260         * recursive bits for other formats here.
3261         */
3262        if (options->output_format & (DIFF_FORMAT_PATCH |
3263                                      DIFF_FORMAT_NUMSTAT |
3264                                      DIFF_FORMAT_DIFFSTAT |
3265                                      DIFF_FORMAT_SHORTSTAT |
3266                                      DIFF_FORMAT_DIRSTAT |
3267                                      DIFF_FORMAT_SUMMARY |
3268                                      DIFF_FORMAT_CHECKDIFF))
3269                DIFF_OPT_SET(options, RECURSIVE);
3270        /*
3271         * Also pickaxe would not work very well if you do not say recursive
3272         */
3273        if (options->pickaxe)
3274                DIFF_OPT_SET(options, RECURSIVE);
3275        /*
3276         * When patches are generated, submodules diffed against the work tree
3277         * must be checked for dirtiness too so it can be shown in the output
3278         */
3279        if (options->output_format & DIFF_FORMAT_PATCH)
3280                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3281
3282        if (options->detect_rename && options->rename_limit < 0)
3283                options->rename_limit = diff_rename_limit_default;
3284        if (options->setup & DIFF_SETUP_USE_CACHE) {
3285                if (!active_cache)
3286                        /* read-cache does not die even when it fails
3287                         * so it is safe for us to do this here.  Also
3288                         * it does not smudge active_cache or active_nr
3289                         * when it fails, so we do not have to worry about
3290                         * cleaning it up ourselves either.
3291                         */
3292                        read_cache();
3293        }
3294        if (options->abbrev <= 0 || 40 < options->abbrev)
3295                options->abbrev = 40; /* full */
3296
3297        /*
3298         * It does not make sense to show the first hit we happened
3299         * to have found.  It does not make sense not to return with
3300         * exit code in such a case either.
3301         */
3302        if (DIFF_OPT_TST(options, QUICK)) {
3303                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3304                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3305        }
3306
3307        return 0;
3308}
3309
3310static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3311{
3312        char c, *eq;
3313        int len;
3314
3315        if (*arg != '-')
3316                return 0;
3317        c = *++arg;
3318        if (!c)
3319                return 0;
3320        if (c == arg_short) {
3321                c = *++arg;
3322                if (!c)
3323                        return 1;
3324                if (val && isdigit(c)) {
3325                        char *end;
3326                        int n = strtoul(arg, &end, 10);
3327                        if (*end)
3328                                return 0;
3329                        *val = n;
3330                        return 1;
3331                }
3332                return 0;
3333        }
3334        if (c != '-')
3335                return 0;
3336        arg++;
3337        eq = strchr(arg, '=');
3338        if (eq)
3339                len = eq - arg;
3340        else
3341                len = strlen(arg);
3342        if (!len || strncmp(arg, arg_long, len))
3343                return 0;
3344        if (eq) {
3345                int n;
3346                char *end;
3347                if (!isdigit(*++eq))
3348                        return 0;
3349                n = strtoul(eq, &end, 10);
3350                if (*end)
3351                        return 0;
3352                *val = n;
3353        }
3354        return 1;
3355}
3356
3357static int diff_scoreopt_parse(const char *opt);
3358
3359static inline int short_opt(char opt, const char **argv,
3360                            const char **optarg)
3361{
3362        const char *arg = argv[0];
3363        if (arg[0] != '-' || arg[1] != opt)
3364                return 0;
3365        if (arg[2] != '\0') {
3366                *optarg = arg + 2;
3367                return 1;
3368        }
3369        if (!argv[1])
3370                die("Option '%c' requires a value", opt);
3371        *optarg = argv[1];
3372        return 2;
3373}
3374
3375int parse_long_opt(const char *opt, const char **argv,
3376                   const char **optarg)
3377{
3378        const char *arg = argv[0];
3379        if (arg[0] != '-' || arg[1] != '-')
3380                return 0;
3381        arg += strlen("--");
3382        if (prefixcmp(arg, opt))
3383                return 0;
3384        arg += strlen(opt);
3385        if (*arg == '=') { /* sticked form: --option=value */
3386                *optarg = arg + 1;
3387                return 1;
3388        }
3389        if (*arg != '\0')
3390                return 0;
3391        /* separate form: --option value */
3392        if (!argv[1])
3393                die("Option '--%s' requires a value", opt);
3394        *optarg = argv[1];
3395        return 2;
3396}
3397
3398static int stat_opt(struct diff_options *options, const char **av)
3399{
3400        const char *arg = av[0];
3401        char *end;
3402        int width = options->stat_width;
3403        int name_width = options->stat_name_width;
3404        int graph_width = options->stat_graph_width;
3405        int count = options->stat_count;
3406        int argcount = 1;
3407
3408        arg += strlen("--stat");
3409        end = (char *)arg;
3410
3411        switch (*arg) {
3412        case '-':
3413                if (!prefixcmp(arg, "-width")) {
3414                        arg += strlen("-width");
3415                        if (*arg == '=')
3416                                width = strtoul(arg + 1, &end, 10);
3417                        else if (!*arg && !av[1])
3418                                die("Option '--stat-width' requires a value");
3419                        else if (!*arg) {
3420                                width = strtoul(av[1], &end, 10);
3421                                argcount = 2;
3422                        }
3423                } else if (!prefixcmp(arg, "-name-width")) {
3424                        arg += strlen("-name-width");
3425                        if (*arg == '=')
3426                                name_width = strtoul(arg + 1, &end, 10);
3427                        else if (!*arg && !av[1])
3428                                die("Option '--stat-name-width' requires a value");
3429                        else if (!*arg) {
3430                                name_width = strtoul(av[1], &end, 10);
3431                                argcount = 2;
3432                        }
3433                } else if (!prefixcmp(arg, "-graph-width")) {
3434                        arg += strlen("-graph-width");
3435                        if (*arg == '=')
3436                                graph_width = strtoul(arg + 1, &end, 10);
3437                        else if (!*arg && !av[1])
3438                                die("Option '--stat-graph-width' requires a value");
3439                        else if (!*arg) {
3440                                graph_width = strtoul(av[1], &end, 10);
3441                                argcount = 2;
3442                        }
3443                } else if (!prefixcmp(arg, "-count")) {
3444                        arg += strlen("-count");
3445                        if (*arg == '=')
3446                                count = strtoul(arg + 1, &end, 10);
3447                        else if (!*arg && !av[1])
3448                                die("Option '--stat-count' requires a value");
3449                        else if (!*arg) {
3450                                count = strtoul(av[1], &end, 10);
3451                                argcount = 2;
3452                        }
3453                }
3454                break;
3455        case '=':
3456                width = strtoul(arg+1, &end, 10);
3457                if (*end == ',')
3458                        name_width = strtoul(end+1, &end, 10);
3459                if (*end == ',')
3460                        count = strtoul(end+1, &end, 10);
3461        }
3462
3463        /* Important! This checks all the error cases! */
3464        if (*end)
3465                return 0;
3466        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3467        options->stat_name_width = name_width;
3468        options->stat_graph_width = graph_width;
3469        options->stat_width = width;
3470        options->stat_count = count;
3471        return argcount;
3472}
3473
3474static int parse_dirstat_opt(struct diff_options *options, const char *params)
3475{
3476        struct strbuf errmsg = STRBUF_INIT;
3477        if (parse_dirstat_params(options, params, &errmsg))
3478                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3479                    errmsg.buf);
3480        strbuf_release(&errmsg);
3481        /*
3482         * The caller knows a dirstat-related option is given from the command
3483         * line; allow it to say "return this_function();"
3484         */
3485        options->output_format |= DIFF_FORMAT_DIRSTAT;
3486        return 1;
3487}
3488
3489int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3490{
3491        const char *arg = av[0];
3492        const char *optarg;
3493        int argcount;
3494
3495        /* Output format options */
3496        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3497                options->output_format |= DIFF_FORMAT_PATCH;
3498        else if (opt_arg(arg, 'U', "unified", &options->context))
3499                options->output_format |= DIFF_FORMAT_PATCH;
3500        else if (!strcmp(arg, "--raw"))
3501                options->output_format |= DIFF_FORMAT_RAW;
3502        else if (!strcmp(arg, "--patch-with-raw"))
3503                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3504        else if (!strcmp(arg, "--numstat"))
3505                options->output_format |= DIFF_FORMAT_NUMSTAT;
3506        else if (!strcmp(arg, "--shortstat"))
3507                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3508        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3509                return parse_dirstat_opt(options, "");
3510        else if (!prefixcmp(arg, "-X"))
3511                return parse_dirstat_opt(options, arg + 2);
3512        else if (!prefixcmp(arg, "--dirstat="))
3513                return parse_dirstat_opt(options, arg + 10);
3514        else if (!strcmp(arg, "--cumulative"))
3515                return parse_dirstat_opt(options, "cumulative");
3516        else if (!strcmp(arg, "--dirstat-by-file"))
3517                return parse_dirstat_opt(options, "files");
3518        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3519                parse_dirstat_opt(options, "files");
3520                return parse_dirstat_opt(options, arg + 18);
3521        }
3522        else if (!strcmp(arg, "--check"))
3523                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3524        else if (!strcmp(arg, "--summary"))
3525                options->output_format |= DIFF_FORMAT_SUMMARY;
3526        else if (!strcmp(arg, "--patch-with-stat"))
3527                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3528        else if (!strcmp(arg, "--name-only"))
3529                options->output_format |= DIFF_FORMAT_NAME;
3530        else if (!strcmp(arg, "--name-status"))
3531                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3532        else if (!strcmp(arg, "-s"))
3533                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3534        else if (!prefixcmp(arg, "--stat"))
3535                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3536                return stat_opt(options, av);
3537
3538        /* renames options */
3539        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3540                 !strcmp(arg, "--break-rewrites")) {
3541                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3542                        return error("invalid argument to -B: %s", arg+2);
3543        }
3544        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3545                 !strcmp(arg, "--find-renames")) {
3546                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3547                        return error("invalid argument to -M: %s", arg+2);
3548                options->detect_rename = DIFF_DETECT_RENAME;
3549        }
3550        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3551                options->irreversible_delete = 1;
3552        }
3553        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3554                 !strcmp(arg, "--find-copies")) {
3555                if (options->detect_rename == DIFF_DETECT_COPY)
3556                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3557                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3558                        return error("invalid argument to -C: %s", arg+2);
3559                options->detect_rename = DIFF_DETECT_COPY;
3560        }
3561        else if (!strcmp(arg, "--no-renames"))
3562                options->detect_rename = 0;
3563        else if (!strcmp(arg, "--rename-empty"))
3564                DIFF_OPT_SET(options, RENAME_EMPTY);
3565        else if (!strcmp(arg, "--no-rename-empty"))
3566                DIFF_OPT_CLR(options, RENAME_EMPTY);
3567        else if (!strcmp(arg, "--relative"))
3568                DIFF_OPT_SET(options, RELATIVE_NAME);
3569        else if (!prefixcmp(arg, "--relative=")) {
3570                DIFF_OPT_SET(options, RELATIVE_NAME);
3571                options->prefix = arg + 11;
3572        }
3573
3574        /* xdiff options */
3575        else if (!strcmp(arg, "--minimal"))
3576                DIFF_XDL_SET(options, NEED_MINIMAL);
3577        else if (!strcmp(arg, "--no-minimal"))
3578                DIFF_XDL_CLR(options, NEED_MINIMAL);
3579        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3580                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3581        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3582                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3583        else if (!strcmp(arg, "--ignore-space-at-eol"))
3584                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3585        else if (!strcmp(arg, "--patience"))
3586                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3587        else if (!strcmp(arg, "--histogram"))
3588                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3589
3590        /* flags options */
3591        else if (!strcmp(arg, "--binary")) {
3592                options->output_format |= DIFF_FORMAT_PATCH;
3593                DIFF_OPT_SET(options, BINARY);
3594        }
3595        else if (!strcmp(arg, "--full-index"))
3596                DIFF_OPT_SET(options, FULL_INDEX);
3597        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3598                DIFF_OPT_SET(options, TEXT);
3599        else if (!strcmp(arg, "-R"))
3600                DIFF_OPT_SET(options, REVERSE_DIFF);
3601        else if (!strcmp(arg, "--find-copies-harder"))
3602                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3603        else if (!strcmp(arg, "--follow"))
3604                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3605        else if (!strcmp(arg, "--color"))
3606                options->use_color = 1;
3607        else if (!prefixcmp(arg, "--color=")) {
3608                int value = git_config_colorbool(NULL, arg+8);
3609                if (value < 0)
3610                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3611                options->use_color = value;
3612        }
3613        else if (!strcmp(arg, "--no-color"))
3614                options->use_color = 0;
3615        else if (!strcmp(arg, "--color-words")) {
3616                options->use_color = 1;
3617                options->word_diff = DIFF_WORDS_COLOR;
3618        }
3619        else if (!prefixcmp(arg, "--color-words=")) {
3620                options->use_color = 1;
3621                options->word_diff = DIFF_WORDS_COLOR;
3622                options->word_regex = arg + 14;
3623        }
3624        else if (!strcmp(arg, "--word-diff")) {
3625                if (options->word_diff == DIFF_WORDS_NONE)
3626                        options->word_diff = DIFF_WORDS_PLAIN;
3627        }
3628        else if (!prefixcmp(arg, "--word-diff=")) {
3629                const char *type = arg + 12;
3630                if (!strcmp(type, "plain"))
3631                        options->word_diff = DIFF_WORDS_PLAIN;
3632                else if (!strcmp(type, "color")) {
3633                        options->use_color = 1;
3634                        options->word_diff = DIFF_WORDS_COLOR;
3635                }
3636                else if (!strcmp(type, "porcelain"))
3637                        options->word_diff = DIFF_WORDS_PORCELAIN;
3638                else if (!strcmp(type, "none"))
3639                        options->word_diff = DIFF_WORDS_NONE;
3640                else
3641                        die("bad --word-diff argument: %s", type);
3642        }
3643        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3644                if (options->word_diff == DIFF_WORDS_NONE)
3645                        options->word_diff = DIFF_WORDS_PLAIN;
3646                options->word_regex = optarg;
3647                return argcount;
3648        }
3649        else if (!strcmp(arg, "--exit-code"))
3650                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3651        else if (!strcmp(arg, "--quiet"))
3652                DIFF_OPT_SET(options, QUICK);
3653        else if (!strcmp(arg, "--ext-diff"))
3654                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3655        else if (!strcmp(arg, "--no-ext-diff"))
3656                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3657        else if (!strcmp(arg, "--textconv"))
3658                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3659        else if (!strcmp(arg, "--no-textconv"))
3660                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3661        else if (!strcmp(arg, "--ignore-submodules")) {
3662                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3663                handle_ignore_submodules_arg(options, "all");
3664        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3665                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3666                handle_ignore_submodules_arg(options, arg + 20);
3667        } else if (!strcmp(arg, "--submodule"))
3668                DIFF_OPT_SET(options, SUBMODULE_LOG);
3669        else if (!prefixcmp(arg, "--submodule=")) {
3670                if (!strcmp(arg + 12, "log"))
3671                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3672        }
3673
3674        /* misc options */
3675        else if (!strcmp(arg, "-z"))
3676                options->line_termination = 0;
3677        else if ((argcount = short_opt('l', av, &optarg))) {
3678                options->rename_limit = strtoul(optarg, NULL, 10);
3679                return argcount;
3680        }
3681        else if ((argcount = short_opt('S', av, &optarg))) {
3682                options->pickaxe = optarg;
3683                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3684                return argcount;
3685        } else if ((argcount = short_opt('G', av, &optarg))) {
3686                options->pickaxe = optarg;
3687                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3688                return argcount;
3689        }
3690        else if (!strcmp(arg, "--pickaxe-all"))
3691                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3692        else if (!strcmp(arg, "--pickaxe-regex"))
3693                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3694        else if ((argcount = short_opt('O', av, &optarg))) {
3695                options->orderfile = optarg;
3696                return argcount;
3697        }
3698        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3699                options->filter = optarg;
3700                return argcount;
3701        }
3702        else if (!strcmp(arg, "--abbrev"))
3703                options->abbrev = DEFAULT_ABBREV;
3704        else if (!prefixcmp(arg, "--abbrev=")) {
3705                options->abbrev = strtoul(arg + 9, NULL, 10);
3706                if (options->abbrev < MINIMUM_ABBREV)
3707                        options->abbrev = MINIMUM_ABBREV;
3708                else if (40 < options->abbrev)
3709                        options->abbrev = 40;
3710        }
3711        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3712                options->a_prefix = optarg;
3713                return argcount;
3714        }
3715        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3716                options->b_prefix = optarg;
3717                return argcount;
3718        }
3719        else if (!strcmp(arg, "--no-prefix"))
3720                options->a_prefix = options->b_prefix = "";
3721        else if (opt_arg(arg, '\0', "inter-hunk-context",
3722                         &options->interhunkcontext))
3723                ;
3724        else if (!strcmp(arg, "-W"))
3725                DIFF_OPT_SET(options, FUNCCONTEXT);
3726        else if (!strcmp(arg, "--function-context"))
3727                DIFF_OPT_SET(options, FUNCCONTEXT);
3728        else if (!strcmp(arg, "--no-function-context"))
3729                DIFF_OPT_CLR(options, FUNCCONTEXT);
3730        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3731                options->file = fopen(optarg, "w");
3732                if (!options->file)
3733                        die_errno("Could not open '%s'", optarg);
3734                options->close_file = 1;
3735                return argcount;
3736        } else
3737                return 0;
3738        return 1;
3739}
3740
3741int parse_rename_score(const char **cp_p)
3742{
3743        unsigned long num, scale;
3744        int ch, dot;
3745        const char *cp = *cp_p;
3746
3747        num = 0;
3748        scale = 1;
3749        dot = 0;
3750        for (;;) {
3751                ch = *cp;
3752                if ( !dot && ch == '.' ) {
3753                        scale = 1;
3754                        dot = 1;
3755                } else if ( ch == '%' ) {
3756                        scale = dot ? scale*100 : 100;
3757                        cp++;   /* % is always at the end */
3758                        break;
3759                } else if ( ch >= '0' && ch <= '9' ) {
3760                        if ( scale < 100000 ) {
3761                                scale *= 10;
3762                                num = (num*10) + (ch-'0');
3763                        }
3764                } else {
3765                        break;
3766                }
3767                cp++;
3768        }
3769        *cp_p = cp;
3770
3771        /* user says num divided by scale and we say internally that
3772         * is MAX_SCORE * num / scale.
3773         */
3774        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3775}
3776
3777static int diff_scoreopt_parse(const char *opt)
3778{
3779        int opt1, opt2, cmd;
3780
3781        if (*opt++ != '-')
3782                return -1;
3783        cmd = *opt++;
3784        if (cmd == '-') {
3785                /* convert the long-form arguments into short-form versions */
3786                if (!prefixcmp(opt, "break-rewrites")) {
3787                        opt += strlen("break-rewrites");
3788                        if (*opt == 0 || *opt++ == '=')
3789                                cmd = 'B';
3790                } else if (!prefixcmp(opt, "find-copies")) {
3791                        opt += strlen("find-copies");
3792                        if (*opt == 0 || *opt++ == '=')
3793                                cmd = 'C';
3794                } else if (!prefixcmp(opt, "find-renames")) {
3795                        opt += strlen("find-renames");
3796                        if (*opt == 0 || *opt++ == '=')
3797                                cmd = 'M';
3798                }
3799        }
3800        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3801                return -1; /* that is not a -M, -C nor -B option */
3802
3803        opt1 = parse_rename_score(&opt);
3804        if (cmd != 'B')
3805                opt2 = 0;
3806        else {
3807                if (*opt == 0)
3808                        opt2 = 0;
3809                else if (*opt != '/')
3810                        return -1; /* we expect -B80/99 or -B80 */
3811                else {
3812                        opt++;
3813                        opt2 = parse_rename_score(&opt);
3814                }
3815        }
3816        if (*opt != 0)
3817                return -1;
3818        return opt1 | (opt2 << 16);
3819}
3820
3821struct diff_queue_struct diff_queued_diff;
3822
3823void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3824{
3825        if (queue->alloc <= queue->nr) {
3826                queue->alloc = alloc_nr(queue->alloc);
3827                queue->queue = xrealloc(queue->queue,
3828                                        sizeof(dp) * queue->alloc);
3829        }
3830        queue->queue[queue->nr++] = dp;
3831}
3832
3833struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3834                                 struct diff_filespec *one,
3835                                 struct diff_filespec *two)
3836{
3837        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3838        dp->one = one;
3839        dp->two = two;
3840        if (queue)
3841                diff_q(queue, dp);
3842        return dp;
3843}
3844
3845void diff_free_filepair(struct diff_filepair *p)
3846{
3847        free_filespec(p->one);
3848        free_filespec(p->two);
3849        free(p);
3850}
3851
3852/* This is different from find_unique_abbrev() in that
3853 * it stuffs the result with dots for alignment.
3854 */
3855const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3856{
3857        int abblen;
3858        const char *abbrev;
3859        if (len == 40)
3860                return sha1_to_hex(sha1);
3861
3862        abbrev = find_unique_abbrev(sha1, len);
3863        abblen = strlen(abbrev);
3864        if (abblen < 37) {
3865                static char hex[41];
3866                if (len < abblen && abblen <= len + 2)
3867                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3868                else
3869                        sprintf(hex, "%s...", abbrev);
3870                return hex;
3871        }
3872        return sha1_to_hex(sha1);
3873}
3874
3875static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3876{
3877        int line_termination = opt->line_termination;
3878        int inter_name_termination = line_termination ? '\t' : '\0';
3879        if (opt->output_prefix) {
3880                struct strbuf *msg = NULL;
3881                msg = opt->output_prefix(opt, opt->output_prefix_data);
3882                fprintf(opt->file, "%s", msg->buf);
3883        }
3884
3885        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3886                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3887                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3888                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3889        }
3890        if (p->score) {
3891                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3892                        inter_name_termination);
3893        } else {
3894                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3895        }
3896
3897        if (p->status == DIFF_STATUS_COPIED ||
3898            p->status == DIFF_STATUS_RENAMED) {
3899                const char *name_a, *name_b;
3900                name_a = p->one->path;
3901                name_b = p->two->path;
3902                strip_prefix(opt->prefix_length, &name_a, &name_b);
3903                write_name_quoted(name_a, opt->file, inter_name_termination);
3904                write_name_quoted(name_b, opt->file, line_termination);
3905        } else {
3906                const char *name_a, *name_b;
3907                name_a = p->one->mode ? p->one->path : p->two->path;
3908                name_b = NULL;
3909                strip_prefix(opt->prefix_length, &name_a, &name_b);
3910                write_name_quoted(name_a, opt->file, line_termination);
3911        }
3912}
3913
3914int diff_unmodified_pair(struct diff_filepair *p)
3915{
3916        /* This function is written stricter than necessary to support
3917         * the currently implemented transformers, but the idea is to
3918         * let transformers to produce diff_filepairs any way they want,
3919         * and filter and clean them up here before producing the output.
3920         */
3921        struct diff_filespec *one = p->one, *two = p->two;
3922
3923        if (DIFF_PAIR_UNMERGED(p))
3924                return 0; /* unmerged is interesting */
3925
3926        /* deletion, addition, mode or type change
3927         * and rename are all interesting.
3928         */
3929        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3930            DIFF_PAIR_MODE_CHANGED(p) ||
3931            strcmp(one->path, two->path))
3932                return 0;
3933
3934        /* both are valid and point at the same path.  that is, we are
3935         * dealing with a change.
3936         */
3937        if (one->sha1_valid && two->sha1_valid &&
3938            !hashcmp(one->sha1, two->sha1) &&
3939            !one->dirty_submodule && !two->dirty_submodule)
3940                return 1; /* no change */
3941        if (!one->sha1_valid && !two->sha1_valid)
3942                return 1; /* both look at the same file on the filesystem. */
3943        return 0;
3944}
3945
3946static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3947{
3948        if (diff_unmodified_pair(p))
3949                return;
3950
3951        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3952            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3953                return; /* no tree diffs in patch format */
3954
3955        run_diff(p, o);
3956}
3957
3958static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3959                            struct diffstat_t *diffstat)
3960{
3961        if (diff_unmodified_pair(p))
3962                return;
3963
3964        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3965            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3966                return; /* no useful stat for tree diffs */
3967
3968        run_diffstat(p, o, diffstat);
3969}
3970
3971static void diff_flush_checkdiff(struct diff_filepair *p,
3972                struct diff_options *o)
3973{
3974        if (diff_unmodified_pair(p))
3975                return;
3976
3977        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3978            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3979                return; /* nothing to check in tree diffs */
3980
3981        run_checkdiff(p, o);
3982}
3983
3984int diff_queue_is_empty(void)
3985{
3986        struct diff_queue_struct *q = &diff_queued_diff;
3987        int i;
3988        for (i = 0; i < q->nr; i++)
3989                if (!diff_unmodified_pair(q->queue[i]))
3990                        return 0;
3991        return 1;
3992}
3993
3994#if DIFF_DEBUG
3995void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3996{
3997        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3998                x, one ? one : "",
3999                s->path,
4000                DIFF_FILE_VALID(s) ? "valid" : "invalid",
4001                s->mode,
4002                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
4003        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
4004                x, one ? one : "",
4005                s->size, s->xfrm_flags);
4006}
4007
4008void diff_debug_filepair(const struct diff_filepair *p, int i)
4009{
4010        diff_debug_filespec(p->one, i, "one");
4011        diff_debug_filespec(p->two, i, "two");
4012        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4013                p->score, p->status ? p->status : '?',
4014                p->one->rename_used, p->broken_pair);
4015}
4016
4017void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4018{
4019        int i;
4020        if (msg)
4021                fprintf(stderr, "%s\n", msg);
4022        fprintf(stderr, "q->nr = %d\n", q->nr);
4023        for (i = 0; i < q->nr; i++) {
4024                struct diff_filepair *p = q->queue[i];
4025                diff_debug_filepair(p, i);
4026        }
4027}
4028#endif
4029
4030static void diff_resolve_rename_copy(void)
4031{
4032        int i;
4033        struct diff_filepair *p;
4034        struct diff_queue_struct *q = &diff_queued_diff;
4035
4036        diff_debug_queue("resolve-rename-copy", q);
4037
4038        for (i = 0; i < q->nr; i++) {
4039                p = q->queue[i];
4040                p->status = 0; /* undecided */
4041                if (DIFF_PAIR_UNMERGED(p))
4042                        p->status = DIFF_STATUS_UNMERGED;
4043                else if (!DIFF_FILE_VALID(p->one))
4044                        p->status = DIFF_STATUS_ADDED;
4045                else if (!DIFF_FILE_VALID(p->two))
4046                        p->status = DIFF_STATUS_DELETED;
4047                else if (DIFF_PAIR_TYPE_CHANGED(p))
4048                        p->status = DIFF_STATUS_TYPE_CHANGED;
4049
4050                /* from this point on, we are dealing with a pair
4051                 * whose both sides are valid and of the same type, i.e.
4052                 * either in-place edit or rename/copy edit.
4053                 */
4054                else if (DIFF_PAIR_RENAME(p)) {
4055                        /*
4056                         * A rename might have re-connected a broken
4057                         * pair up, causing the pathnames to be the
4058                         * same again. If so, that's not a rename at
4059                         * all, just a modification..
4060                         *
4061                         * Otherwise, see if this source was used for
4062                         * multiple renames, in which case we decrement
4063                         * the count, and call it a copy.
4064                         */
4065                        if (!strcmp(p->one->path, p->two->path))
4066                                p->status = DIFF_STATUS_MODIFIED;
4067                        else if (--p->one->rename_used > 0)
4068                                p->status = DIFF_STATUS_COPIED;
4069                        else
4070                                p->status = DIFF_STATUS_RENAMED;
4071                }
4072                else if (hashcmp(p->one->sha1, p->two->sha1) ||
4073                         p->one->mode != p->two->mode ||
4074                         p->one->dirty_submodule ||
4075                         p->two->dirty_submodule ||
4076                         is_null_sha1(p->one->sha1))
4077                        p->status = DIFF_STATUS_MODIFIED;
4078                else {
4079                        /* This is a "no-change" entry and should not
4080                         * happen anymore, but prepare for broken callers.
4081                         */
4082                        error("feeding unmodified %s to diffcore",
4083                              p->one->path);
4084                        p->status = DIFF_STATUS_UNKNOWN;
4085                }
4086        }
4087        diff_debug_queue("resolve-rename-copy done", q);
4088}
4089
4090static int check_pair_status(struct diff_filepair *p)
4091{
4092        switch (p->status) {
4093        case DIFF_STATUS_UNKNOWN:
4094                return 0;
4095        case 0:
4096                die("internal error in diff-resolve-rename-copy");
4097        default:
4098                return 1;
4099        }
4100}
4101
4102static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4103{
4104        int fmt = opt->output_format;
4105
4106        if (fmt & DIFF_FORMAT_CHECKDIFF)
4107                diff_flush_checkdiff(p, opt);
4108        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4109                diff_flush_raw(p, opt);
4110        else if (fmt & DIFF_FORMAT_NAME) {
4111                const char *name_a, *name_b;
4112                name_a = p->two->path;
4113                name_b = NULL;
4114                strip_prefix(opt->prefix_length, &name_a, &name_b);
4115                write_name_quoted(name_a, opt->file, opt->line_termination);
4116        }
4117}
4118
4119static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4120{
4121        if (fs->mode)
4122                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4123        else
4124                fprintf(file, " %s ", newdelete);
4125        write_name_quoted(fs->path, file, '\n');
4126}
4127
4128
4129static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4130                const char *line_prefix)
4131{
4132        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4133                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4134                        p->two->mode, show_name ? ' ' : '\n');
4135                if (show_name) {
4136                        write_name_quoted(p->two->path, file, '\n');
4137                }
4138        }
4139}
4140
4141static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4142                        const char *line_prefix)
4143{
4144        char *names = pprint_rename(p->one->path, p->two->path);
4145
4146        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4147        free(names);
4148        show_mode_change(file, p, 0, line_prefix);
4149}
4150
4151static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4152{
4153        FILE *file = opt->file;
4154        char *line_prefix = "";
4155
4156        if (opt->output_prefix) {
4157                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
4158                line_prefix = buf->buf;
4159        }
4160
4161        switch(p->status) {
4162        case DIFF_STATUS_DELETED:
4163                fputs(line_prefix, file);
4164                show_file_mode_name(file, "delete", p->one);
4165                break;
4166        case DIFF_STATUS_ADDED:
4167                fputs(line_prefix, file);
4168                show_file_mode_name(file, "create", p->two);
4169                break;
4170        case DIFF_STATUS_COPIED:
4171                fputs(line_prefix, file);
4172                show_rename_copy(file, "copy", p, line_prefix);
4173                break;
4174        case DIFF_STATUS_RENAMED:
4175                fputs(line_prefix, file);
4176                show_rename_copy(file, "rename", p, line_prefix);
4177                break;
4178        default:
4179                if (p->score) {
4180                        fprintf(file, "%s rewrite ", line_prefix);
4181                        write_name_quoted(p->two->path, file, ' ');
4182                        fprintf(file, "(%d%%)\n", similarity_index(p));
4183                }
4184                show_mode_change(file, p, !p->score, line_prefix);
4185                break;
4186        }
4187}
4188
4189struct patch_id_t {
4190        git_SHA_CTX *ctx;
4191        int patchlen;
4192};
4193
4194static int remove_space(char *line, int len)
4195{
4196        int i;
4197        char *dst = line;
4198        unsigned char c;
4199
4200        for (i = 0; i < len; i++)
4201                if (!isspace((c = line[i])))
4202                        *dst++ = c;
4203
4204        return dst - line;
4205}
4206
4207static void patch_id_consume(void *priv, char *line, unsigned long len)
4208{
4209        struct patch_id_t *data = priv;
4210        int new_len;
4211
4212        /* Ignore line numbers when computing the SHA1 of the patch */
4213        if (!prefixcmp(line, "@@ -"))
4214                return;
4215
4216        new_len = remove_space(line, len);
4217
4218        git_SHA1_Update(data->ctx, line, new_len);
4219        data->patchlen += new_len;
4220}
4221
4222/* returns 0 upon success, and writes result into sha1 */
4223static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4224{
4225        struct diff_queue_struct *q = &diff_queued_diff;
4226        int i;
4227        git_SHA_CTX ctx;
4228        struct patch_id_t data;
4229        char buffer[PATH_MAX * 4 + 20];
4230
4231        git_SHA1_Init(&ctx);
4232        memset(&data, 0, sizeof(struct patch_id_t));
4233        data.ctx = &ctx;
4234
4235        for (i = 0; i < q->nr; i++) {
4236                xpparam_t xpp;
4237                xdemitconf_t xecfg;
4238                mmfile_t mf1, mf2;
4239                struct diff_filepair *p = q->queue[i];
4240                int len1, len2;
4241
4242                memset(&xpp, 0, sizeof(xpp));
4243                memset(&xecfg, 0, sizeof(xecfg));
4244                if (p->status == 0)
4245                        return error("internal diff status error");
4246                if (p->status == DIFF_STATUS_UNKNOWN)
4247                        continue;
4248                if (diff_unmodified_pair(p))
4249                        continue;
4250                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4251                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4252                        continue;
4253                if (DIFF_PAIR_UNMERGED(p))
4254                        continue;
4255
4256                diff_fill_sha1_info(p->one);
4257                diff_fill_sha1_info(p->two);
4258                if (fill_mmfile(&mf1, p->one) < 0 ||
4259                                fill_mmfile(&mf2, p->two) < 0)
4260                        return error("unable to read files to diff");
4261
4262                len1 = remove_space(p->one->path, strlen(p->one->path));
4263                len2 = remove_space(p->two->path, strlen(p->two->path));
4264                if (p->one->mode == 0)
4265                        len1 = snprintf(buffer, sizeof(buffer),
4266                                        "diff--gita/%.*sb/%.*s"
4267                                        "newfilemode%06o"
4268                                        "---/dev/null"
4269                                        "+++b/%.*s",
4270                                        len1, p->one->path,
4271                                        len2, p->two->path,
4272                                        p->two->mode,
4273                                        len2, p->two->path);
4274                else if (p->two->mode == 0)
4275                        len1 = snprintf(buffer, sizeof(buffer),
4276                                        "diff--gita/%.*sb/%.*s"
4277                                        "deletedfilemode%06o"
4278                                        "---a/%.*s"
4279                                        "+++/dev/null",
4280                                        len1, p->one->path,
4281                                        len2, p->two->path,
4282                                        p->one->mode,
4283                                        len1, p->one->path);
4284                else
4285                        len1 = snprintf(buffer, sizeof(buffer),
4286                                        "diff--gita/%.*sb/%.*s"
4287                                        "---a/%.*s"
4288                                        "+++b/%.*s",
4289                                        len1, p->one->path,
4290                                        len2, p->two->path,
4291                                        len1, p->one->path,
4292                                        len2, p->two->path);
4293                git_SHA1_Update(&ctx, buffer, len1);
4294
4295                if (diff_filespec_is_binary(p->one) ||
4296                    diff_filespec_is_binary(p->two)) {
4297                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4298                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4299                        continue;
4300                }
4301
4302                xpp.flags = 0;
4303                xecfg.ctxlen = 3;
4304                xecfg.flags = 0;
4305                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4306                              &xpp, &xecfg);
4307        }
4308
4309        git_SHA1_Final(sha1, &ctx);
4310        return 0;
4311}
4312
4313int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4314{
4315        struct diff_queue_struct *q = &diff_queued_diff;
4316        int i;
4317        int result = diff_get_patch_id(options, sha1);
4318
4319        for (i = 0; i < q->nr; i++)
4320                diff_free_filepair(q->queue[i]);
4321
4322        free(q->queue);
4323        DIFF_QUEUE_CLEAR(q);
4324
4325        return result;
4326}
4327
4328static int is_summary_empty(const struct diff_queue_struct *q)
4329{
4330        int i;
4331
4332        for (i = 0; i < q->nr; i++) {
4333                const struct diff_filepair *p = q->queue[i];
4334
4335                switch (p->status) {
4336                case DIFF_STATUS_DELETED:
4337                case DIFF_STATUS_ADDED:
4338                case DIFF_STATUS_COPIED:
4339                case DIFF_STATUS_RENAMED:
4340                        return 0;
4341                default:
4342                        if (p->score)
4343                                return 0;
4344                        if (p->one->mode && p->two->mode &&
4345                            p->one->mode != p->two->mode)
4346                                return 0;
4347                        break;
4348                }
4349        }
4350        return 1;
4351}
4352
4353static const char rename_limit_warning[] =
4354"inexact rename detection was skipped due to too many files.";
4355
4356static const char degrade_cc_to_c_warning[] =
4357"only found copies from modified paths due to too many files.";
4358
4359static const char rename_limit_advice[] =
4360"you may want to set your %s variable to at least "
4361"%d and retry the command.";
4362
4363void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4364{
4365        if (degraded_cc)
4366                warning(degrade_cc_to_c_warning);
4367        else if (needed)
4368                warning(rename_limit_warning);
4369        else
4370                return;
4371        if (0 < needed && needed < 32767)
4372                warning(rename_limit_advice, varname, needed);
4373}
4374
4375void diff_flush(struct diff_options *options)
4376{
4377        struct diff_queue_struct *q = &diff_queued_diff;
4378        int i, output_format = options->output_format;
4379        int separator = 0;
4380        int dirstat_by_line = 0;
4381
4382        /*
4383         * Order: raw, stat, summary, patch
4384         * or:    name/name-status/checkdiff (other bits clear)
4385         */
4386        if (!q->nr)
4387                goto free_queue;
4388
4389        if (output_format & (DIFF_FORMAT_RAW |
4390                             DIFF_FORMAT_NAME |
4391                             DIFF_FORMAT_NAME_STATUS |
4392                             DIFF_FORMAT_CHECKDIFF)) {
4393                for (i = 0; i < q->nr; i++) {
4394                        struct diff_filepair *p = q->queue[i];
4395                        if (check_pair_status(p))
4396                                flush_one_pair(p, options);
4397                }
4398                separator++;
4399        }
4400
4401        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4402                dirstat_by_line = 1;
4403
4404        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4405            dirstat_by_line) {
4406                struct diffstat_t diffstat;
4407
4408                memset(&diffstat, 0, sizeof(struct diffstat_t));
4409                for (i = 0; i < q->nr; i++) {
4410                        struct diff_filepair *p = q->queue[i];
4411                        if (check_pair_status(p))
4412                                diff_flush_stat(p, options, &diffstat);
4413                }
4414                if (output_format & DIFF_FORMAT_NUMSTAT)
4415                        show_numstat(&diffstat, options);
4416                if (output_format & DIFF_FORMAT_DIFFSTAT)
4417                        show_stats(&diffstat, options);
4418                if (output_format & DIFF_FORMAT_SHORTSTAT)
4419                        show_shortstats(&diffstat, options);
4420                if (output_format & DIFF_FORMAT_DIRSTAT)
4421                        show_dirstat_by_line(&diffstat, options);
4422                free_diffstat_info(&diffstat);
4423                separator++;
4424        }
4425        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4426                show_dirstat(options);
4427
4428        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4429                for (i = 0; i < q->nr; i++) {
4430                        diff_summary(options, q->queue[i]);
4431                }
4432                separator++;
4433        }
4434
4435        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4436            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4437            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4438                /*
4439                 * run diff_flush_patch for the exit status. setting
4440                 * options->file to /dev/null should be safe, becaue we
4441                 * aren't supposed to produce any output anyway.
4442                 */
4443                if (options->close_file)
4444                        fclose(options->file);
4445                options->file = fopen("/dev/null", "w");
4446                if (!options->file)
4447                        die_errno("Could not open /dev/null");
4448                options->close_file = 1;
4449                for (i = 0; i < q->nr; i++) {
4450                        struct diff_filepair *p = q->queue[i];
4451                        if (check_pair_status(p))
4452                                diff_flush_patch(p, options);
4453                        if (options->found_changes)
4454                                break;
4455                }
4456        }
4457
4458        if (output_format & DIFF_FORMAT_PATCH) {
4459                if (separator) {
4460                        if (options->output_prefix) {
4461                                struct strbuf *msg = NULL;
4462                                msg = options->output_prefix(options,
4463                                        options->output_prefix_data);
4464                                fwrite(msg->buf, msg->len, 1, stdout);
4465                        }
4466                        putc(options->line_termination, options->file);
4467                        if (options->stat_sep) {
4468                                /* attach patch instead of inline */
4469                                fputs(options->stat_sep, options->file);
4470                        }
4471                }
4472
4473                for (i = 0; i < q->nr; i++) {
4474                        struct diff_filepair *p = q->queue[i];
4475                        if (check_pair_status(p))
4476                                diff_flush_patch(p, options);
4477                }
4478        }
4479
4480        if (output_format & DIFF_FORMAT_CALLBACK)
4481                options->format_callback(q, options, options->format_callback_data);
4482
4483        for (i = 0; i < q->nr; i++)
4484                diff_free_filepair(q->queue[i]);
4485free_queue:
4486        free(q->queue);
4487        DIFF_QUEUE_CLEAR(q);
4488        if (options->close_file)
4489                fclose(options->file);
4490
4491        /*
4492         * Report the content-level differences with HAS_CHANGES;
4493         * diff_addremove/diff_change does not set the bit when
4494         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4495         */
4496        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4497                if (options->found_changes)
4498                        DIFF_OPT_SET(options, HAS_CHANGES);
4499                else
4500                        DIFF_OPT_CLR(options, HAS_CHANGES);
4501        }
4502}
4503
4504static void diffcore_apply_filter(const char *filter)
4505{
4506        int i;
4507        struct diff_queue_struct *q = &diff_queued_diff;
4508        struct diff_queue_struct outq;
4509        DIFF_QUEUE_CLEAR(&outq);
4510
4511        if (!filter)
4512                return;
4513
4514        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4515                int found;
4516                for (i = found = 0; !found && i < q->nr; i++) {
4517                        struct diff_filepair *p = q->queue[i];
4518                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4519                             ((p->score &&
4520                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4521                              (!p->score &&
4522                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4523                            ((p->status != DIFF_STATUS_MODIFIED) &&
4524                             strchr(filter, p->status)))
4525                                found++;
4526                }
4527                if (found)
4528                        return;
4529
4530                /* otherwise we will clear the whole queue
4531                 * by copying the empty outq at the end of this
4532                 * function, but first clear the current entries
4533                 * in the queue.
4534                 */
4535                for (i = 0; i < q->nr; i++)
4536                        diff_free_filepair(q->queue[i]);
4537        }
4538        else {
4539                /* Only the matching ones */
4540                for (i = 0; i < q->nr; i++) {
4541                        struct diff_filepair *p = q->queue[i];
4542
4543                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4544                             ((p->score &&
4545                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4546                              (!p->score &&
4547                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4548                            ((p->status != DIFF_STATUS_MODIFIED) &&
4549                             strchr(filter, p->status)))
4550                                diff_q(&outq, p);
4551                        else
4552                                diff_free_filepair(p);
4553                }
4554        }
4555        free(q->queue);
4556        *q = outq;
4557}
4558
4559/* Check whether two filespecs with the same mode and size are identical */
4560static int diff_filespec_is_identical(struct diff_filespec *one,
4561                                      struct diff_filespec *two)
4562{
4563        if (S_ISGITLINK(one->mode))
4564                return 0;
4565        if (diff_populate_filespec(one, 0))
4566                return 0;
4567        if (diff_populate_filespec(two, 0))
4568                return 0;
4569        return !memcmp(one->data, two->data, one->size);
4570}
4571
4572static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4573{
4574        int i;
4575        struct diff_queue_struct *q = &diff_queued_diff;
4576        struct diff_queue_struct outq;
4577        DIFF_QUEUE_CLEAR(&outq);
4578
4579        for (i = 0; i < q->nr; i++) {
4580                struct diff_filepair *p = q->queue[i];
4581
4582                /*
4583                 * 1. Entries that come from stat info dirtiness
4584                 *    always have both sides (iow, not create/delete),
4585                 *    one side of the object name is unknown, with
4586                 *    the same mode and size.  Keep the ones that
4587                 *    do not match these criteria.  They have real
4588                 *    differences.
4589                 *
4590                 * 2. At this point, the file is known to be modified,
4591                 *    with the same mode and size, and the object
4592                 *    name of one side is unknown.  Need to inspect
4593                 *    the identical contents.
4594                 */
4595                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4596                    !DIFF_FILE_VALID(p->two) ||
4597                    (p->one->sha1_valid && p->two->sha1_valid) ||
4598                    (p->one->mode != p->two->mode) ||
4599                    diff_populate_filespec(p->one, 1) ||
4600                    diff_populate_filespec(p->two, 1) ||
4601                    (p->one->size != p->two->size) ||
4602                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4603                        diff_q(&outq, p);
4604                else {
4605                        /*
4606                         * The caller can subtract 1 from skip_stat_unmatch
4607                         * to determine how many paths were dirty only
4608                         * due to stat info mismatch.
4609                         */
4610                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4611                                diffopt->skip_stat_unmatch++;
4612                        diff_free_filepair(p);
4613                }
4614        }
4615        free(q->queue);
4616        *q = outq;
4617}
4618
4619static int diffnamecmp(const void *a_, const void *b_)
4620{
4621        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4622        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4623        const char *name_a, *name_b;
4624
4625        name_a = a->one ? a->one->path : a->two->path;
4626        name_b = b->one ? b->one->path : b->two->path;
4627        return strcmp(name_a, name_b);
4628}
4629
4630void diffcore_fix_diff_index(struct diff_options *options)
4631{
4632        struct diff_queue_struct *q = &diff_queued_diff;
4633        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4634}
4635
4636void diffcore_std(struct diff_options *options)
4637{
4638        if (options->skip_stat_unmatch)
4639                diffcore_skip_stat_unmatch(options);
4640        if (!options->found_follow) {
4641                /* See try_to_follow_renames() in tree-diff.c */
4642                if (options->break_opt != -1)
4643                        diffcore_break(options->break_opt);
4644                if (options->detect_rename)
4645                        diffcore_rename(options);
4646                if (options->break_opt != -1)
4647                        diffcore_merge_broken();
4648        }
4649        if (options->pickaxe)
4650                diffcore_pickaxe(options);
4651        if (options->orderfile)
4652                diffcore_order(options->orderfile);
4653        if (!options->found_follow)
4654                /* See try_to_follow_renames() in tree-diff.c */
4655                diff_resolve_rename_copy();
4656        diffcore_apply_filter(options->filter);
4657
4658        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4659                DIFF_OPT_SET(options, HAS_CHANGES);
4660        else
4661                DIFF_OPT_CLR(options, HAS_CHANGES);
4662
4663        options->found_follow = 0;
4664}
4665
4666int diff_result_code(struct diff_options *opt, int status)
4667{
4668        int result = 0;
4669
4670        diff_warn_rename_limit("diff.renamelimit",
4671                               opt->needed_rename_limit,
4672                               opt->degraded_cc_to_c);
4673        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4674            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4675                return status;
4676        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4677            DIFF_OPT_TST(opt, HAS_CHANGES))
4678                result |= 01;
4679        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4680            DIFF_OPT_TST(opt, CHECK_FAILED))
4681                result |= 02;
4682        return result;
4683}
4684
4685int diff_can_quit_early(struct diff_options *opt)
4686{
4687        return (DIFF_OPT_TST(opt, QUICK) &&
4688                !opt->filter &&
4689                DIFF_OPT_TST(opt, HAS_CHANGES));
4690}
4691
4692/*
4693 * Shall changes to this submodule be ignored?
4694 *
4695 * Submodule changes can be configured to be ignored separately for each path,
4696 * but that configuration can be overridden from the command line.
4697 */
4698static int is_submodule_ignored(const char *path, struct diff_options *options)
4699{
4700        int ignored = 0;
4701        unsigned orig_flags = options->flags;
4702        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4703                set_diffopt_flags_from_submodule_config(options, path);
4704        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4705                ignored = 1;
4706        options->flags = orig_flags;
4707        return ignored;
4708}
4709
4710void diff_addremove(struct diff_options *options,
4711                    int addremove, unsigned mode,
4712                    const unsigned char *sha1,
4713                    const char *concatpath, unsigned dirty_submodule)
4714{
4715        struct diff_filespec *one, *two;
4716
4717        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4718                return;
4719
4720        /* This may look odd, but it is a preparation for
4721         * feeding "there are unchanged files which should
4722         * not produce diffs, but when you are doing copy
4723         * detection you would need them, so here they are"
4724         * entries to the diff-core.  They will be prefixed
4725         * with something like '=' or '*' (I haven't decided
4726         * which but should not make any difference).
4727         * Feeding the same new and old to diff_change()
4728         * also has the same effect.
4729         * Before the final output happens, they are pruned after
4730         * merged into rename/copy pairs as appropriate.
4731         */
4732        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4733                addremove = (addremove == '+' ? '-' :
4734                             addremove == '-' ? '+' : addremove);
4735
4736        if (options->prefix &&
4737            strncmp(concatpath, options->prefix, options->prefix_length))
4738                return;
4739
4740        one = alloc_filespec(concatpath);
4741        two = alloc_filespec(concatpath);
4742
4743        if (addremove != '+')
4744                fill_filespec(one, sha1, mode);
4745        if (addremove != '-') {
4746                fill_filespec(two, sha1, mode);
4747                two->dirty_submodule = dirty_submodule;
4748        }
4749
4750        diff_queue(&diff_queued_diff, one, two);
4751        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4752                DIFF_OPT_SET(options, HAS_CHANGES);
4753}
4754
4755void diff_change(struct diff_options *options,
4756                 unsigned old_mode, unsigned new_mode,
4757                 const unsigned char *old_sha1,
4758                 const unsigned char *new_sha1,
4759                 const char *concatpath,
4760                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4761{
4762        struct diff_filespec *one, *two;
4763
4764        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4765            is_submodule_ignored(concatpath, options))
4766                return;
4767
4768        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4769                unsigned tmp;
4770                const unsigned char *tmp_c;
4771                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4772                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4773                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4774                        new_dirty_submodule = tmp;
4775        }
4776
4777        if (options->prefix &&
4778            strncmp(concatpath, options->prefix, options->prefix_length))
4779                return;
4780
4781        one = alloc_filespec(concatpath);
4782        two = alloc_filespec(concatpath);
4783        fill_filespec(one, old_sha1, old_mode);
4784        fill_filespec(two, new_sha1, new_mode);
4785        one->dirty_submodule = old_dirty_submodule;
4786        two->dirty_submodule = new_dirty_submodule;
4787
4788        diff_queue(&diff_queued_diff, one, two);
4789        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4790                DIFF_OPT_SET(options, HAS_CHANGES);
4791}
4792
4793struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4794{
4795        struct diff_filepair *pair;
4796        struct diff_filespec *one, *two;
4797
4798        if (options->prefix &&
4799            strncmp(path, options->prefix, options->prefix_length))
4800                return NULL;
4801
4802        one = alloc_filespec(path);
4803        two = alloc_filespec(path);
4804        pair = diff_queue(&diff_queued_diff, one, two);
4805        pair->is_unmerged = 1;
4806        return pair;
4807}
4808
4809static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4810                size_t *outsize)
4811{
4812        struct diff_tempfile *temp;
4813        const char *argv[3];
4814        const char **arg = argv;
4815        struct child_process child;
4816        struct strbuf buf = STRBUF_INIT;
4817        int err = 0;
4818
4819        temp = prepare_temp_file(spec->path, spec);
4820        *arg++ = pgm;
4821        *arg++ = temp->name;
4822        *arg = NULL;
4823
4824        memset(&child, 0, sizeof(child));
4825        child.use_shell = 1;
4826        child.argv = argv;
4827        child.out = -1;
4828        if (start_command(&child)) {
4829                remove_tempfile();
4830                return NULL;
4831        }
4832
4833        if (strbuf_read(&buf, child.out, 0) < 0)
4834                err = error("error reading from textconv command '%s'", pgm);
4835        close(child.out);
4836
4837        if (finish_command(&child) || err) {
4838                strbuf_release(&buf);
4839                remove_tempfile();
4840                return NULL;
4841        }
4842        remove_tempfile();
4843
4844        return strbuf_detach(&buf, outsize);
4845}
4846
4847size_t fill_textconv(struct userdiff_driver *driver,
4848                     struct diff_filespec *df,
4849                     char **outbuf)
4850{
4851        size_t size;
4852
4853        if (!driver || !driver->textconv) {
4854                if (!DIFF_FILE_VALID(df)) {
4855                        *outbuf = "";
4856                        return 0;
4857                }
4858                if (diff_populate_filespec(df, 0))
4859                        die("unable to read files to diff");
4860                *outbuf = df->data;
4861                return df->size;
4862        }
4863
4864        if (driver->textconv_cache && df->sha1_valid) {
4865                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4866                                          &size);
4867                if (*outbuf)
4868                        return size;
4869        }
4870
4871        *outbuf = run_textconv(driver->textconv, df, &size);
4872        if (!*outbuf)
4873                die("unable to read files to diff");
4874
4875        if (driver->textconv_cache && df->sha1_valid) {
4876                /* ignore errors, as we might be in a readonly repository */
4877                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4878                                size);
4879                /*
4880                 * we could save up changes and flush them all at the end,
4881                 * but we would need an extra call after all diffing is done.
4882                 * Since generating a cache entry is the slow path anyway,
4883                 * this extra overhead probably isn't a big deal.
4884                 */
4885                notes_cache_write(driver->textconv_cache);
4886        }
4887
4888        return size;
4889}