diff.con commit Merge branch 'th/difftool-diffall' (cae0977)
   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                        fprintf(options->file, "%s%"PRIuMAX"%s",
1619                                del_c, deleted, reset);
1620                        fprintf(options->file, " -> ");
1621                        fprintf(options->file, "%s%"PRIuMAX"%s",
1622                                add_c, added, reset);
1623                        fprintf(options->file, " bytes");
1624                        fprintf(options->file, "\n");
1625                        continue;
1626                }
1627                else if (data->files[i]->is_unmerged) {
1628                        fprintf(options->file, "%s", line_prefix);
1629                        show_name(options->file, prefix, name, len);
1630                        fprintf(options->file, " Unmerged\n");
1631                        continue;
1632                }
1633
1634                /*
1635                 * scale the add/delete
1636                 */
1637                add = added;
1638                del = deleted;
1639                adds += add;
1640                dels += del;
1641
1642                if (graph_width <= max_change) {
1643                        int total = add + del;
1644
1645                        total = scale_linear(add + del, graph_width, max_change);
1646                        if (total < 2 && add && del)
1647                                /* width >= 2 due to the sanity check */
1648                                total = 2;
1649                        if (add < del) {
1650                                add = scale_linear(add, graph_width, max_change);
1651                                del = total - add;
1652                        } else {
1653                                del = scale_linear(del, graph_width, max_change);
1654                                add = total - del;
1655                        }
1656                }
1657                fprintf(options->file, "%s", line_prefix);
1658                show_name(options->file, prefix, name, len);
1659                fprintf(options->file, " %*"PRIuMAX"%s",
1660                        number_width, added + deleted,
1661                        added + deleted ? " " : "");
1662                show_graph(options->file, '+', add, add_c, reset);
1663                show_graph(options->file, '-', del, del_c, reset);
1664                fprintf(options->file, "\n");
1665        }
1666        for (i = count; i < data->nr; i++) {
1667                uintmax_t added = data->files[i]->added;
1668                uintmax_t deleted = data->files[i]->deleted;
1669                if (!data->files[i]->is_renamed &&
1670                         (added + deleted == 0)) {
1671                        total_files--;
1672                        continue;
1673                }
1674                adds += added;
1675                dels += deleted;
1676                if (!extra_shown)
1677                        fprintf(options->file, "%s ...\n", line_prefix);
1678                extra_shown = 1;
1679        }
1680        fprintf(options->file, "%s", line_prefix);
1681        print_stat_summary(options->file, total_files, adds, dels);
1682}
1683
1684static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1685{
1686        int i, adds = 0, dels = 0, total_files = data->nr;
1687
1688        if (data->nr == 0)
1689                return;
1690
1691        for (i = 0; i < data->nr; i++) {
1692                if (!data->files[i]->is_binary &&
1693                    !data->files[i]->is_unmerged) {
1694                        int added = data->files[i]->added;
1695                        int deleted= data->files[i]->deleted;
1696                        if (!data->files[i]->is_renamed &&
1697                            (added + deleted == 0)) {
1698                                total_files--;
1699                        } else {
1700                                adds += added;
1701                                dels += deleted;
1702                        }
1703                }
1704        }
1705        if (options->output_prefix) {
1706                struct strbuf *msg = NULL;
1707                msg = options->output_prefix(options,
1708                                options->output_prefix_data);
1709                fprintf(options->file, "%s", msg->buf);
1710        }
1711        print_stat_summary(options->file, total_files, adds, dels);
1712}
1713
1714static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1715{
1716        int i;
1717
1718        if (data->nr == 0)
1719                return;
1720
1721        for (i = 0; i < data->nr; i++) {
1722                struct diffstat_file *file = data->files[i];
1723
1724                if (options->output_prefix) {
1725                        struct strbuf *msg = NULL;
1726                        msg = options->output_prefix(options,
1727                                        options->output_prefix_data);
1728                        fprintf(options->file, "%s", msg->buf);
1729                }
1730
1731                if (file->is_binary)
1732                        fprintf(options->file, "-\t-\t");
1733                else
1734                        fprintf(options->file,
1735                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1736                                file->added, file->deleted);
1737                if (options->line_termination) {
1738                        fill_print_name(file);
1739                        if (!file->is_renamed)
1740                                write_name_quoted(file->name, options->file,
1741                                                  options->line_termination);
1742                        else {
1743                                fputs(file->print_name, options->file);
1744                                putc(options->line_termination, options->file);
1745                        }
1746                } else {
1747                        if (file->is_renamed) {
1748                                putc('\0', options->file);
1749                                write_name_quoted(file->from_name, options->file, '\0');
1750                        }
1751                        write_name_quoted(file->name, options->file, '\0');
1752                }
1753        }
1754}
1755
1756struct dirstat_file {
1757        const char *name;
1758        unsigned long changed;
1759};
1760
1761struct dirstat_dir {
1762        struct dirstat_file *files;
1763        int alloc, nr, permille, cumulative;
1764};
1765
1766static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1767                unsigned long changed, const char *base, int baselen)
1768{
1769        unsigned long this_dir = 0;
1770        unsigned int sources = 0;
1771        const char *line_prefix = "";
1772        struct strbuf *msg = NULL;
1773
1774        if (opt->output_prefix) {
1775                msg = opt->output_prefix(opt, opt->output_prefix_data);
1776                line_prefix = msg->buf;
1777        }
1778
1779        while (dir->nr) {
1780                struct dirstat_file *f = dir->files;
1781                int namelen = strlen(f->name);
1782                unsigned long this;
1783                char *slash;
1784
1785                if (namelen < baselen)
1786                        break;
1787                if (memcmp(f->name, base, baselen))
1788                        break;
1789                slash = strchr(f->name + baselen, '/');
1790                if (slash) {
1791                        int newbaselen = slash + 1 - f->name;
1792                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1793                        sources++;
1794                } else {
1795                        this = f->changed;
1796                        dir->files++;
1797                        dir->nr--;
1798                        sources += 2;
1799                }
1800                this_dir += this;
1801        }
1802
1803        /*
1804         * We don't report dirstat's for
1805         *  - the top level
1806         *  - or cases where everything came from a single directory
1807         *    under this directory (sources == 1).
1808         */
1809        if (baselen && sources != 1) {
1810                if (this_dir) {
1811                        int permille = this_dir * 1000 / changed;
1812                        if (permille >= dir->permille) {
1813                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1814                                        permille / 10, permille % 10, baselen, base);
1815                                if (!dir->cumulative)
1816                                        return 0;
1817                        }
1818                }
1819        }
1820        return this_dir;
1821}
1822
1823static int dirstat_compare(const void *_a, const void *_b)
1824{
1825        const struct dirstat_file *a = _a;
1826        const struct dirstat_file *b = _b;
1827        return strcmp(a->name, b->name);
1828}
1829
1830static void show_dirstat(struct diff_options *options)
1831{
1832        int i;
1833        unsigned long changed;
1834        struct dirstat_dir dir;
1835        struct diff_queue_struct *q = &diff_queued_diff;
1836
1837        dir.files = NULL;
1838        dir.alloc = 0;
1839        dir.nr = 0;
1840        dir.permille = options->dirstat_permille;
1841        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1842
1843        changed = 0;
1844        for (i = 0; i < q->nr; i++) {
1845                struct diff_filepair *p = q->queue[i];
1846                const char *name;
1847                unsigned long copied, added, damage;
1848                int content_changed;
1849
1850                name = p->two->path ? p->two->path : p->one->path;
1851
1852                if (p->one->sha1_valid && p->two->sha1_valid)
1853                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1854                else
1855                        content_changed = 1;
1856
1857                if (!content_changed) {
1858                        /*
1859                         * The SHA1 has not changed, so pre-/post-content is
1860                         * identical. We can therefore skip looking at the
1861                         * file contents altogether.
1862                         */
1863                        damage = 0;
1864                        goto found_damage;
1865                }
1866
1867                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1868                        /*
1869                         * In --dirstat-by-file mode, we don't really need to
1870                         * look at the actual file contents at all.
1871                         * The fact that the SHA1 changed is enough for us to
1872                         * add this file to the list of results
1873                         * (with each file contributing equal damage).
1874                         */
1875                        damage = 1;
1876                        goto found_damage;
1877                }
1878
1879                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1880                        diff_populate_filespec(p->one, 0);
1881                        diff_populate_filespec(p->two, 0);
1882                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1883                                               &copied, &added);
1884                        diff_free_filespec_data(p->one);
1885                        diff_free_filespec_data(p->two);
1886                } else if (DIFF_FILE_VALID(p->one)) {
1887                        diff_populate_filespec(p->one, 1);
1888                        copied = added = 0;
1889                        diff_free_filespec_data(p->one);
1890                } else if (DIFF_FILE_VALID(p->two)) {
1891                        diff_populate_filespec(p->two, 1);
1892                        copied = 0;
1893                        added = p->two->size;
1894                        diff_free_filespec_data(p->two);
1895                } else
1896                        continue;
1897
1898                /*
1899                 * Original minus copied is the removed material,
1900                 * added is the new material.  They are both damages
1901                 * made to the preimage.
1902                 * If the resulting damage is zero, we know that
1903                 * diffcore_count_changes() considers the two entries to
1904                 * be identical, but since content_changed is true, we
1905                 * know that there must have been _some_ kind of change,
1906                 * so we force all entries to have damage > 0.
1907                 */
1908                damage = (p->one->size - copied) + added;
1909                if (!damage)
1910                        damage = 1;
1911
1912found_damage:
1913                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1914                dir.files[dir.nr].name = name;
1915                dir.files[dir.nr].changed = damage;
1916                changed += damage;
1917                dir.nr++;
1918        }
1919
1920        /* This can happen even with many files, if everything was renames */
1921        if (!changed)
1922                return;
1923
1924        /* Show all directories with more than x% of the changes */
1925        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1926        gather_dirstat(options, &dir, changed, "", 0);
1927}
1928
1929static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1930{
1931        int i;
1932        unsigned long changed;
1933        struct dirstat_dir dir;
1934
1935        if (data->nr == 0)
1936                return;
1937
1938        dir.files = NULL;
1939        dir.alloc = 0;
1940        dir.nr = 0;
1941        dir.permille = options->dirstat_permille;
1942        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1943
1944        changed = 0;
1945        for (i = 0; i < data->nr; i++) {
1946                struct diffstat_file *file = data->files[i];
1947                unsigned long damage = file->added + file->deleted;
1948                if (file->is_binary)
1949                        /*
1950                         * binary files counts bytes, not lines. Must find some
1951                         * way to normalize binary bytes vs. textual lines.
1952                         * The following heuristic assumes that there are 64
1953                         * bytes per "line".
1954                         * This is stupid and ugly, but very cheap...
1955                         */
1956                        damage = (damage + 63) / 64;
1957                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1958                dir.files[dir.nr].name = file->name;
1959                dir.files[dir.nr].changed = damage;
1960                changed += damage;
1961                dir.nr++;
1962        }
1963
1964        /* This can happen even with many files, if everything was renames */
1965        if (!changed)
1966                return;
1967
1968        /* Show all directories with more than x% of the changes */
1969        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1970        gather_dirstat(options, &dir, changed, "", 0);
1971}
1972
1973static void free_diffstat_info(struct diffstat_t *diffstat)
1974{
1975        int i;
1976        for (i = 0; i < diffstat->nr; i++) {
1977                struct diffstat_file *f = diffstat->files[i];
1978                if (f->name != f->print_name)
1979                        free(f->print_name);
1980                free(f->name);
1981                free(f->from_name);
1982                free(f);
1983        }
1984        free(diffstat->files);
1985}
1986
1987struct checkdiff_t {
1988        const char *filename;
1989        int lineno;
1990        int conflict_marker_size;
1991        struct diff_options *o;
1992        unsigned ws_rule;
1993        unsigned status;
1994};
1995
1996static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1997{
1998        char firstchar;
1999        int cnt;
2000
2001        if (len < marker_size + 1)
2002                return 0;
2003        firstchar = line[0];
2004        switch (firstchar) {
2005        case '=': case '>': case '<': case '|':
2006                break;
2007        default:
2008                return 0;
2009        }
2010        for (cnt = 1; cnt < marker_size; cnt++)
2011                if (line[cnt] != firstchar)
2012                        return 0;
2013        /* line[1] thru line[marker_size-1] are same as firstchar */
2014        if (len < marker_size + 1 || !isspace(line[marker_size]))
2015                return 0;
2016        return 1;
2017}
2018
2019static void checkdiff_consume(void *priv, char *line, unsigned long len)
2020{
2021        struct checkdiff_t *data = priv;
2022        int marker_size = data->conflict_marker_size;
2023        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2024        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2025        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2026        char *err;
2027        char *line_prefix = "";
2028        struct strbuf *msgbuf;
2029
2030        assert(data->o);
2031        if (data->o->output_prefix) {
2032                msgbuf = data->o->output_prefix(data->o,
2033                        data->o->output_prefix_data);
2034                line_prefix = msgbuf->buf;
2035        }
2036
2037        if (line[0] == '+') {
2038                unsigned bad;
2039                data->lineno++;
2040                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2041                        data->status |= 1;
2042                        fprintf(data->o->file,
2043                                "%s%s:%d: leftover conflict marker\n",
2044                                line_prefix, data->filename, data->lineno);
2045                }
2046                bad = ws_check(line + 1, len - 1, data->ws_rule);
2047                if (!bad)
2048                        return;
2049                data->status |= bad;
2050                err = whitespace_error_string(bad);
2051                fprintf(data->o->file, "%s%s:%d: %s.\n",
2052                        line_prefix, data->filename, data->lineno, err);
2053                free(err);
2054                emit_line(data->o, set, reset, line, 1);
2055                ws_check_emit(line + 1, len - 1, data->ws_rule,
2056                              data->o->file, set, reset, ws);
2057        } else if (line[0] == ' ') {
2058                data->lineno++;
2059        } else if (line[0] == '@') {
2060                char *plus = strchr(line, '+');
2061                if (plus)
2062                        data->lineno = strtol(plus, NULL, 10) - 1;
2063                else
2064                        die("invalid diff");
2065        }
2066}
2067
2068static unsigned char *deflate_it(char *data,
2069                                 unsigned long size,
2070                                 unsigned long *result_size)
2071{
2072        int bound;
2073        unsigned char *deflated;
2074        git_zstream stream;
2075
2076        memset(&stream, 0, sizeof(stream));
2077        git_deflate_init(&stream, zlib_compression_level);
2078        bound = git_deflate_bound(&stream, size);
2079        deflated = xmalloc(bound);
2080        stream.next_out = deflated;
2081        stream.avail_out = bound;
2082
2083        stream.next_in = (unsigned char *)data;
2084        stream.avail_in = size;
2085        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2086                ; /* nothing */
2087        git_deflate_end(&stream);
2088        *result_size = stream.total_out;
2089        return deflated;
2090}
2091
2092static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2093{
2094        void *cp;
2095        void *delta;
2096        void *deflated;
2097        void *data;
2098        unsigned long orig_size;
2099        unsigned long delta_size;
2100        unsigned long deflate_size;
2101        unsigned long data_size;
2102
2103        /* We could do deflated delta, or we could do just deflated two,
2104         * whichever is smaller.
2105         */
2106        delta = NULL;
2107        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2108        if (one->size && two->size) {
2109                delta = diff_delta(one->ptr, one->size,
2110                                   two->ptr, two->size,
2111                                   &delta_size, deflate_size);
2112                if (delta) {
2113                        void *to_free = delta;
2114                        orig_size = delta_size;
2115                        delta = deflate_it(delta, delta_size, &delta_size);
2116                        free(to_free);
2117                }
2118        }
2119
2120        if (delta && delta_size < deflate_size) {
2121                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2122                free(deflated);
2123                data = delta;
2124                data_size = delta_size;
2125        }
2126        else {
2127                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2128                free(delta);
2129                data = deflated;
2130                data_size = deflate_size;
2131        }
2132
2133        /* emit data encoded in base85 */
2134        cp = data;
2135        while (data_size) {
2136                int bytes = (52 < data_size) ? 52 : data_size;
2137                char line[70];
2138                data_size -= bytes;
2139                if (bytes <= 26)
2140                        line[0] = bytes + 'A' - 1;
2141                else
2142                        line[0] = bytes - 26 + 'a' - 1;
2143                encode_85(line + 1, cp, bytes);
2144                cp = (char *) cp + bytes;
2145                fprintf(file, "%s", prefix);
2146                fputs(line, file);
2147                fputc('\n', file);
2148        }
2149        fprintf(file, "%s\n", prefix);
2150        free(data);
2151}
2152
2153static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2154{
2155        fprintf(file, "%sGIT binary patch\n", prefix);
2156        emit_binary_diff_body(file, one, two, prefix);
2157        emit_binary_diff_body(file, two, one, prefix);
2158}
2159
2160int diff_filespec_is_binary(struct diff_filespec *one)
2161{
2162        if (one->is_binary == -1) {
2163                diff_filespec_load_driver(one);
2164                if (one->driver->binary != -1)
2165                        one->is_binary = one->driver->binary;
2166                else {
2167                        if (!one->data && DIFF_FILE_VALID(one))
2168                                diff_populate_filespec(one, 0);
2169                        if (one->data)
2170                                one->is_binary = buffer_is_binary(one->data,
2171                                                one->size);
2172                        if (one->is_binary == -1)
2173                                one->is_binary = 0;
2174                }
2175        }
2176        return one->is_binary;
2177}
2178
2179static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2180{
2181        diff_filespec_load_driver(one);
2182        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2183}
2184
2185void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2186{
2187        if (!options->a_prefix)
2188                options->a_prefix = a;
2189        if (!options->b_prefix)
2190                options->b_prefix = b;
2191}
2192
2193struct userdiff_driver *get_textconv(struct diff_filespec *one)
2194{
2195        if (!DIFF_FILE_VALID(one))
2196                return NULL;
2197
2198        diff_filespec_load_driver(one);
2199        return userdiff_get_textconv(one->driver);
2200}
2201
2202static void builtin_diff(const char *name_a,
2203                         const char *name_b,
2204                         struct diff_filespec *one,
2205                         struct diff_filespec *two,
2206                         const char *xfrm_msg,
2207                         int must_show_header,
2208                         struct diff_options *o,
2209                         int complete_rewrite)
2210{
2211        mmfile_t mf1, mf2;
2212        const char *lbl[2];
2213        char *a_one, *b_two;
2214        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2215        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2216        const char *a_prefix, *b_prefix;
2217        struct userdiff_driver *textconv_one = NULL;
2218        struct userdiff_driver *textconv_two = NULL;
2219        struct strbuf header = STRBUF_INIT;
2220        struct strbuf *msgbuf;
2221        char *line_prefix = "";
2222
2223        if (o->output_prefix) {
2224                msgbuf = o->output_prefix(o, o->output_prefix_data);
2225                line_prefix = msgbuf->buf;
2226        }
2227
2228        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2229                        (!one->mode || S_ISGITLINK(one->mode)) &&
2230                        (!two->mode || S_ISGITLINK(two->mode))) {
2231                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2232                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2233                show_submodule_summary(o->file, one ? one->path : two->path,
2234                                one->sha1, two->sha1, two->dirty_submodule,
2235                                del, add, reset);
2236                return;
2237        }
2238
2239        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2240                textconv_one = get_textconv(one);
2241                textconv_two = get_textconv(two);
2242        }
2243
2244        diff_set_mnemonic_prefix(o, "a/", "b/");
2245        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2246                a_prefix = o->b_prefix;
2247                b_prefix = o->a_prefix;
2248        } else {
2249                a_prefix = o->a_prefix;
2250                b_prefix = o->b_prefix;
2251        }
2252
2253        /* Never use a non-valid filename anywhere if at all possible */
2254        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2255        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2256
2257        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2258        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2259        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2260        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2261        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2262        if (lbl[0][0] == '/') {
2263                /* /dev/null */
2264                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2265                if (xfrm_msg)
2266                        strbuf_addstr(&header, xfrm_msg);
2267                must_show_header = 1;
2268        }
2269        else if (lbl[1][0] == '/') {
2270                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2271                if (xfrm_msg)
2272                        strbuf_addstr(&header, xfrm_msg);
2273                must_show_header = 1;
2274        }
2275        else {
2276                if (one->mode != two->mode) {
2277                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2278                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2279                        must_show_header = 1;
2280                }
2281                if (xfrm_msg)
2282                        strbuf_addstr(&header, xfrm_msg);
2283
2284                /*
2285                 * we do not run diff between different kind
2286                 * of objects.
2287                 */
2288                if ((one->mode ^ two->mode) & S_IFMT)
2289                        goto free_ab_and_return;
2290                if (complete_rewrite &&
2291                    (textconv_one || !diff_filespec_is_binary(one)) &&
2292                    (textconv_two || !diff_filespec_is_binary(two))) {
2293                        fprintf(o->file, "%s", header.buf);
2294                        strbuf_reset(&header);
2295                        emit_rewrite_diff(name_a, name_b, one, two,
2296                                                textconv_one, textconv_two, o);
2297                        o->found_changes = 1;
2298                        goto free_ab_and_return;
2299                }
2300        }
2301
2302        if (o->irreversible_delete && lbl[1][0] == '/') {
2303                fprintf(o->file, "%s", header.buf);
2304                strbuf_reset(&header);
2305                goto free_ab_and_return;
2306        } else if (!DIFF_OPT_TST(o, TEXT) &&
2307            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2308              (!textconv_two && diff_filespec_is_binary(two)) )) {
2309                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2310                        die("unable to read files to diff");
2311                /* Quite common confusing case */
2312                if (mf1.size == mf2.size &&
2313                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2314                        if (must_show_header)
2315                                fprintf(o->file, "%s", header.buf);
2316                        goto free_ab_and_return;
2317                }
2318                fprintf(o->file, "%s", header.buf);
2319                strbuf_reset(&header);
2320                if (DIFF_OPT_TST(o, BINARY))
2321                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2322                else
2323                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2324                                line_prefix, lbl[0], lbl[1]);
2325                o->found_changes = 1;
2326        } else {
2327                /* Crazy xdl interfaces.. */
2328                const char *diffopts = getenv("GIT_DIFF_OPTS");
2329                xpparam_t xpp;
2330                xdemitconf_t xecfg;
2331                struct emit_callback ecbdata;
2332                const struct userdiff_funcname *pe;
2333
2334                if (must_show_header) {
2335                        fprintf(o->file, "%s", header.buf);
2336                        strbuf_reset(&header);
2337                }
2338
2339                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2340                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2341
2342                pe = diff_funcname_pattern(one);
2343                if (!pe)
2344                        pe = diff_funcname_pattern(two);
2345
2346                memset(&xpp, 0, sizeof(xpp));
2347                memset(&xecfg, 0, sizeof(xecfg));
2348                memset(&ecbdata, 0, sizeof(ecbdata));
2349                ecbdata.label_path = lbl;
2350                ecbdata.color_diff = want_color(o->use_color);
2351                ecbdata.found_changesp = &o->found_changes;
2352                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2353                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2354                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2355                ecbdata.opt = o;
2356                ecbdata.header = header.len ? &header : NULL;
2357                xpp.flags = o->xdl_opts;
2358                xecfg.ctxlen = o->context;
2359                xecfg.interhunkctxlen = o->interhunkcontext;
2360                xecfg.flags = XDL_EMIT_FUNCNAMES;
2361                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2362                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2363                if (pe)
2364                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2365                if (!diffopts)
2366                        ;
2367                else if (!prefixcmp(diffopts, "--unified="))
2368                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2369                else if (!prefixcmp(diffopts, "-u"))
2370                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2371                if (o->word_diff)
2372                        init_diff_words_data(&ecbdata, o, one, two);
2373                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2374                              &xpp, &xecfg);
2375                if (o->word_diff)
2376                        free_diff_words_data(&ecbdata);
2377                if (textconv_one)
2378                        free(mf1.ptr);
2379                if (textconv_two)
2380                        free(mf2.ptr);
2381                xdiff_clear_find_func(&xecfg);
2382        }
2383
2384 free_ab_and_return:
2385        strbuf_release(&header);
2386        diff_free_filespec_data(one);
2387        diff_free_filespec_data(two);
2388        free(a_one);
2389        free(b_two);
2390        return;
2391}
2392
2393static void builtin_diffstat(const char *name_a, const char *name_b,
2394                             struct diff_filespec *one,
2395                             struct diff_filespec *two,
2396                             struct diffstat_t *diffstat,
2397                             struct diff_options *o,
2398                             int complete_rewrite)
2399{
2400        mmfile_t mf1, mf2;
2401        struct diffstat_file *data;
2402
2403        data = diffstat_add(diffstat, name_a, name_b);
2404
2405        if (!one || !two) {
2406                data->is_unmerged = 1;
2407                return;
2408        }
2409
2410        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2411                data->is_binary = 1;
2412                data->added = diff_filespec_size(two);
2413                data->deleted = diff_filespec_size(one);
2414        }
2415
2416        else if (complete_rewrite) {
2417                diff_populate_filespec(one, 0);
2418                diff_populate_filespec(two, 0);
2419                data->deleted = count_lines(one->data, one->size);
2420                data->added = count_lines(two->data, two->size);
2421        }
2422
2423        else {
2424                /* Crazy xdl interfaces.. */
2425                xpparam_t xpp;
2426                xdemitconf_t xecfg;
2427
2428                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2429                        die("unable to read files to diff");
2430
2431                memset(&xpp, 0, sizeof(xpp));
2432                memset(&xecfg, 0, sizeof(xecfg));
2433                xpp.flags = o->xdl_opts;
2434                xecfg.ctxlen = o->context;
2435                xecfg.interhunkctxlen = o->interhunkcontext;
2436                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2437                              &xpp, &xecfg);
2438        }
2439
2440        diff_free_filespec_data(one);
2441        diff_free_filespec_data(two);
2442}
2443
2444static void builtin_checkdiff(const char *name_a, const char *name_b,
2445                              const char *attr_path,
2446                              struct diff_filespec *one,
2447                              struct diff_filespec *two,
2448                              struct diff_options *o)
2449{
2450        mmfile_t mf1, mf2;
2451        struct checkdiff_t data;
2452
2453        if (!two)
2454                return;
2455
2456        memset(&data, 0, sizeof(data));
2457        data.filename = name_b ? name_b : name_a;
2458        data.lineno = 0;
2459        data.o = o;
2460        data.ws_rule = whitespace_rule(attr_path);
2461        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2462
2463        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2464                die("unable to read files to diff");
2465
2466        /*
2467         * All the other codepaths check both sides, but not checking
2468         * the "old" side here is deliberate.  We are checking the newly
2469         * introduced changes, and as long as the "new" side is text, we
2470         * can and should check what it introduces.
2471         */
2472        if (diff_filespec_is_binary(two))
2473                goto free_and_return;
2474        else {
2475                /* Crazy xdl interfaces.. */
2476                xpparam_t xpp;
2477                xdemitconf_t xecfg;
2478
2479                memset(&xpp, 0, sizeof(xpp));
2480                memset(&xecfg, 0, sizeof(xecfg));
2481                xecfg.ctxlen = 1; /* at least one context line */
2482                xpp.flags = 0;
2483                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2484                              &xpp, &xecfg);
2485
2486                if (data.ws_rule & WS_BLANK_AT_EOF) {
2487                        struct emit_callback ecbdata;
2488                        int blank_at_eof;
2489
2490                        ecbdata.ws_rule = data.ws_rule;
2491                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2492                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2493
2494                        if (blank_at_eof) {
2495                                static char *err;
2496                                if (!err)
2497                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2498                                fprintf(o->file, "%s:%d: %s.\n",
2499                                        data.filename, blank_at_eof, err);
2500                                data.status = 1; /* report errors */
2501                        }
2502                }
2503        }
2504 free_and_return:
2505        diff_free_filespec_data(one);
2506        diff_free_filespec_data(two);
2507        if (data.status)
2508                DIFF_OPT_SET(o, CHECK_FAILED);
2509}
2510
2511struct diff_filespec *alloc_filespec(const char *path)
2512{
2513        int namelen = strlen(path);
2514        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2515
2516        memset(spec, 0, sizeof(*spec));
2517        spec->path = (char *)(spec + 1);
2518        memcpy(spec->path, path, namelen+1);
2519        spec->count = 1;
2520        spec->is_binary = -1;
2521        return spec;
2522}
2523
2524void free_filespec(struct diff_filespec *spec)
2525{
2526        if (!--spec->count) {
2527                diff_free_filespec_data(spec);
2528                free(spec);
2529        }
2530}
2531
2532void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2533                   unsigned short mode)
2534{
2535        if (mode) {
2536                spec->mode = canon_mode(mode);
2537                hashcpy(spec->sha1, sha1);
2538                spec->sha1_valid = !is_null_sha1(sha1);
2539        }
2540}
2541
2542/*
2543 * Given a name and sha1 pair, if the index tells us the file in
2544 * the work tree has that object contents, return true, so that
2545 * prepare_temp_file() does not have to inflate and extract.
2546 */
2547static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2548{
2549        struct cache_entry *ce;
2550        struct stat st;
2551        int pos, len;
2552
2553        /*
2554         * We do not read the cache ourselves here, because the
2555         * benchmark with my previous version that always reads cache
2556         * shows that it makes things worse for diff-tree comparing
2557         * two linux-2.6 kernel trees in an already checked out work
2558         * tree.  This is because most diff-tree comparisons deal with
2559         * only a small number of files, while reading the cache is
2560         * expensive for a large project, and its cost outweighs the
2561         * savings we get by not inflating the object to a temporary
2562         * file.  Practically, this code only helps when we are used
2563         * by diff-cache --cached, which does read the cache before
2564         * calling us.
2565         */
2566        if (!active_cache)
2567                return 0;
2568
2569        /* We want to avoid the working directory if our caller
2570         * doesn't need the data in a normal file, this system
2571         * is rather slow with its stat/open/mmap/close syscalls,
2572         * and the object is contained in a pack file.  The pack
2573         * is probably already open and will be faster to obtain
2574         * the data through than the working directory.  Loose
2575         * objects however would tend to be slower as they need
2576         * to be individually opened and inflated.
2577         */
2578        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2579                return 0;
2580
2581        len = strlen(name);
2582        pos = cache_name_pos(name, len);
2583        if (pos < 0)
2584                return 0;
2585        ce = active_cache[pos];
2586
2587        /*
2588         * This is not the sha1 we are looking for, or
2589         * unreusable because it is not a regular file.
2590         */
2591        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2592                return 0;
2593
2594        /*
2595         * If ce is marked as "assume unchanged", there is no
2596         * guarantee that work tree matches what we are looking for.
2597         */
2598        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2599                return 0;
2600
2601        /*
2602         * If ce matches the file in the work tree, we can reuse it.
2603         */
2604        if (ce_uptodate(ce) ||
2605            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2606                return 1;
2607
2608        return 0;
2609}
2610
2611static int populate_from_stdin(struct diff_filespec *s)
2612{
2613        struct strbuf buf = STRBUF_INIT;
2614        size_t size = 0;
2615
2616        if (strbuf_read(&buf, 0, 0) < 0)
2617                return error("error while reading from stdin %s",
2618                                     strerror(errno));
2619
2620        s->should_munmap = 0;
2621        s->data = strbuf_detach(&buf, &size);
2622        s->size = size;
2623        s->should_free = 1;
2624        return 0;
2625}
2626
2627static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2628{
2629        int len;
2630        char *data = xmalloc(100), *dirty = "";
2631
2632        /* Are we looking at the work tree? */
2633        if (s->dirty_submodule)
2634                dirty = "-dirty";
2635
2636        len = snprintf(data, 100,
2637                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2638        s->data = data;
2639        s->size = len;
2640        s->should_free = 1;
2641        if (size_only) {
2642                s->data = NULL;
2643                free(data);
2644        }
2645        return 0;
2646}
2647
2648/*
2649 * While doing rename detection and pickaxe operation, we may need to
2650 * grab the data for the blob (or file) for our own in-core comparison.
2651 * diff_filespec has data and size fields for this purpose.
2652 */
2653int diff_populate_filespec(struct diff_filespec *s, int size_only)
2654{
2655        int err = 0;
2656        if (!DIFF_FILE_VALID(s))
2657                die("internal error: asking to populate invalid file.");
2658        if (S_ISDIR(s->mode))
2659                return -1;
2660
2661        if (s->data)
2662                return 0;
2663
2664        if (size_only && 0 < s->size)
2665                return 0;
2666
2667        if (S_ISGITLINK(s->mode))
2668                return diff_populate_gitlink(s, size_only);
2669
2670        if (!s->sha1_valid ||
2671            reuse_worktree_file(s->path, s->sha1, 0)) {
2672                struct strbuf buf = STRBUF_INIT;
2673                struct stat st;
2674                int fd;
2675
2676                if (!strcmp(s->path, "-"))
2677                        return populate_from_stdin(s);
2678
2679                if (lstat(s->path, &st) < 0) {
2680                        if (errno == ENOENT) {
2681                        err_empty:
2682                                err = -1;
2683                        empty:
2684                                s->data = (char *)"";
2685                                s->size = 0;
2686                                return err;
2687                        }
2688                }
2689                s->size = xsize_t(st.st_size);
2690                if (!s->size)
2691                        goto empty;
2692                if (S_ISLNK(st.st_mode)) {
2693                        struct strbuf sb = STRBUF_INIT;
2694
2695                        if (strbuf_readlink(&sb, s->path, s->size))
2696                                goto err_empty;
2697                        s->size = sb.len;
2698                        s->data = strbuf_detach(&sb, NULL);
2699                        s->should_free = 1;
2700                        return 0;
2701                }
2702                if (size_only)
2703                        return 0;
2704                fd = open(s->path, O_RDONLY);
2705                if (fd < 0)
2706                        goto err_empty;
2707                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2708                close(fd);
2709                s->should_munmap = 1;
2710
2711                /*
2712                 * Convert from working tree format to canonical git format
2713                 */
2714                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2715                        size_t size = 0;
2716                        munmap(s->data, s->size);
2717                        s->should_munmap = 0;
2718                        s->data = strbuf_detach(&buf, &size);
2719                        s->size = size;
2720                        s->should_free = 1;
2721                }
2722        }
2723        else {
2724                enum object_type type;
2725                if (size_only) {
2726                        type = sha1_object_info(s->sha1, &s->size);
2727                        if (type < 0)
2728                                die("unable to read %s", sha1_to_hex(s->sha1));
2729                } else {
2730                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2731                        if (!s->data)
2732                                die("unable to read %s", sha1_to_hex(s->sha1));
2733                        s->should_free = 1;
2734                }
2735        }
2736        return 0;
2737}
2738
2739void diff_free_filespec_blob(struct diff_filespec *s)
2740{
2741        if (s->should_free)
2742                free(s->data);
2743        else if (s->should_munmap)
2744                munmap(s->data, s->size);
2745
2746        if (s->should_free || s->should_munmap) {
2747                s->should_free = s->should_munmap = 0;
2748                s->data = NULL;
2749        }
2750}
2751
2752void diff_free_filespec_data(struct diff_filespec *s)
2753{
2754        diff_free_filespec_blob(s);
2755        free(s->cnt_data);
2756        s->cnt_data = NULL;
2757}
2758
2759static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2760                           void *blob,
2761                           unsigned long size,
2762                           const unsigned char *sha1,
2763                           int mode)
2764{
2765        int fd;
2766        struct strbuf buf = STRBUF_INIT;
2767        struct strbuf template = STRBUF_INIT;
2768        char *path_dup = xstrdup(path);
2769        const char *base = basename(path_dup);
2770
2771        /* Generate "XXXXXX_basename.ext" */
2772        strbuf_addstr(&template, "XXXXXX_");
2773        strbuf_addstr(&template, base);
2774
2775        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2776                        strlen(base) + 1);
2777        if (fd < 0)
2778                die_errno("unable to create temp-file");
2779        if (convert_to_working_tree(path,
2780                        (const char *)blob, (size_t)size, &buf)) {
2781                blob = buf.buf;
2782                size = buf.len;
2783        }
2784        if (write_in_full(fd, blob, size) != size)
2785                die_errno("unable to write temp-file");
2786        close(fd);
2787        temp->name = temp->tmp_path;
2788        strcpy(temp->hex, sha1_to_hex(sha1));
2789        temp->hex[40] = 0;
2790        sprintf(temp->mode, "%06o", mode);
2791        strbuf_release(&buf);
2792        strbuf_release(&template);
2793        free(path_dup);
2794}
2795
2796static struct diff_tempfile *prepare_temp_file(const char *name,
2797                struct diff_filespec *one)
2798{
2799        struct diff_tempfile *temp = claim_diff_tempfile();
2800
2801        if (!DIFF_FILE_VALID(one)) {
2802        not_a_valid_file:
2803                /* A '-' entry produces this for file-2, and
2804                 * a '+' entry produces this for file-1.
2805                 */
2806                temp->name = "/dev/null";
2807                strcpy(temp->hex, ".");
2808                strcpy(temp->mode, ".");
2809                return temp;
2810        }
2811
2812        if (!remove_tempfile_installed) {
2813                atexit(remove_tempfile);
2814                sigchain_push_common(remove_tempfile_on_signal);
2815                remove_tempfile_installed = 1;
2816        }
2817
2818        if (!one->sha1_valid ||
2819            reuse_worktree_file(name, one->sha1, 1)) {
2820                struct stat st;
2821                if (lstat(name, &st) < 0) {
2822                        if (errno == ENOENT)
2823                                goto not_a_valid_file;
2824                        die_errno("stat(%s)", name);
2825                }
2826                if (S_ISLNK(st.st_mode)) {
2827                        struct strbuf sb = STRBUF_INIT;
2828                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2829                                die_errno("readlink(%s)", name);
2830                        prep_temp_blob(name, temp, sb.buf, sb.len,
2831                                       (one->sha1_valid ?
2832                                        one->sha1 : null_sha1),
2833                                       (one->sha1_valid ?
2834                                        one->mode : S_IFLNK));
2835                        strbuf_release(&sb);
2836                }
2837                else {
2838                        /* we can borrow from the file in the work tree */
2839                        temp->name = name;
2840                        if (!one->sha1_valid)
2841                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2842                        else
2843                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2844                        /* Even though we may sometimes borrow the
2845                         * contents from the work tree, we always want
2846                         * one->mode.  mode is trustworthy even when
2847                         * !(one->sha1_valid), as long as
2848                         * DIFF_FILE_VALID(one).
2849                         */
2850                        sprintf(temp->mode, "%06o", one->mode);
2851                }
2852                return temp;
2853        }
2854        else {
2855                if (diff_populate_filespec(one, 0))
2856                        die("cannot read data blob for %s", one->path);
2857                prep_temp_blob(name, temp, one->data, one->size,
2858                               one->sha1, one->mode);
2859        }
2860        return temp;
2861}
2862
2863/* An external diff command takes:
2864 *
2865 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2866 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2867 *
2868 */
2869static void run_external_diff(const char *pgm,
2870                              const char *name,
2871                              const char *other,
2872                              struct diff_filespec *one,
2873                              struct diff_filespec *two,
2874                              const char *xfrm_msg,
2875                              int complete_rewrite)
2876{
2877        const char *spawn_arg[10];
2878        int retval;
2879        const char **arg = &spawn_arg[0];
2880
2881        if (one && two) {
2882                struct diff_tempfile *temp_one, *temp_two;
2883                const char *othername = (other ? other : name);
2884                temp_one = prepare_temp_file(name, one);
2885                temp_two = prepare_temp_file(othername, two);
2886                *arg++ = pgm;
2887                *arg++ = name;
2888                *arg++ = temp_one->name;
2889                *arg++ = temp_one->hex;
2890                *arg++ = temp_one->mode;
2891                *arg++ = temp_two->name;
2892                *arg++ = temp_two->hex;
2893                *arg++ = temp_two->mode;
2894                if (other) {
2895                        *arg++ = other;
2896                        *arg++ = xfrm_msg;
2897                }
2898        } else {
2899                *arg++ = pgm;
2900                *arg++ = name;
2901        }
2902        *arg = NULL;
2903        fflush(NULL);
2904        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2905        remove_tempfile();
2906        if (retval) {
2907                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2908                exit(1);
2909        }
2910}
2911
2912static int similarity_index(struct diff_filepair *p)
2913{
2914        return p->score * 100 / MAX_SCORE;
2915}
2916
2917static void fill_metainfo(struct strbuf *msg,
2918                          const char *name,
2919                          const char *other,
2920                          struct diff_filespec *one,
2921                          struct diff_filespec *two,
2922                          struct diff_options *o,
2923                          struct diff_filepair *p,
2924                          int *must_show_header,
2925                          int use_color)
2926{
2927        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2928        const char *reset = diff_get_color(use_color, DIFF_RESET);
2929        struct strbuf *msgbuf;
2930        char *line_prefix = "";
2931
2932        *must_show_header = 1;
2933        if (o->output_prefix) {
2934                msgbuf = o->output_prefix(o, o->output_prefix_data);
2935                line_prefix = msgbuf->buf;
2936        }
2937        strbuf_init(msg, PATH_MAX * 2 + 300);
2938        switch (p->status) {
2939        case DIFF_STATUS_COPIED:
2940                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2941                            line_prefix, set, similarity_index(p));
2942                strbuf_addf(msg, "%s\n%s%scopy from ",
2943                            reset,  line_prefix, set);
2944                quote_c_style(name, msg, NULL, 0);
2945                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2946                quote_c_style(other, msg, NULL, 0);
2947                strbuf_addf(msg, "%s\n", reset);
2948                break;
2949        case DIFF_STATUS_RENAMED:
2950                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2951                            line_prefix, set, similarity_index(p));
2952                strbuf_addf(msg, "%s\n%s%srename from ",
2953                            reset, line_prefix, set);
2954                quote_c_style(name, msg, NULL, 0);
2955                strbuf_addf(msg, "%s\n%s%srename to ",
2956                            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_MODIFIED:
2961                if (p->score) {
2962                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2963                                    line_prefix,
2964                                    set, similarity_index(p), reset);
2965                        break;
2966                }
2967                /* fallthru */
2968        default:
2969                *must_show_header = 0;
2970        }
2971        if (one && two && hashcmp(one->sha1, two->sha1)) {
2972                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2973
2974                if (DIFF_OPT_TST(o, BINARY)) {
2975                        mmfile_t mf;
2976                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2977                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2978                                abbrev = 40;
2979                }
2980                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2981                            find_unique_abbrev(one->sha1, abbrev));
2982                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2983                if (one->mode == two->mode)
2984                        strbuf_addf(msg, " %06o", one->mode);
2985                strbuf_addf(msg, "%s\n", reset);
2986        }
2987}
2988
2989static void run_diff_cmd(const char *pgm,
2990                         const char *name,
2991                         const char *other,
2992                         const char *attr_path,
2993                         struct diff_filespec *one,
2994                         struct diff_filespec *two,
2995                         struct strbuf *msg,
2996                         struct diff_options *o,
2997                         struct diff_filepair *p)
2998{
2999        const char *xfrm_msg = NULL;
3000        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3001        int must_show_header = 0;
3002
3003        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3004                pgm = NULL;
3005        else {
3006                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3007                if (drv && drv->external)
3008                        pgm = drv->external;
3009        }
3010
3011        if (msg) {
3012                /*
3013                 * don't use colors when the header is intended for an
3014                 * external diff driver
3015                 */
3016                fill_metainfo(msg, name, other, one, two, o, p,
3017                              &must_show_header,
3018                              want_color(o->use_color) && !pgm);
3019                xfrm_msg = msg->len ? msg->buf : NULL;
3020        }
3021
3022        if (pgm) {
3023                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3024                                  complete_rewrite);
3025                return;
3026        }
3027        if (one && two)
3028                builtin_diff(name, other ? other : name,
3029                             one, two, xfrm_msg, must_show_header,
3030                             o, complete_rewrite);
3031        else
3032                fprintf(o->file, "* Unmerged path %s\n", name);
3033}
3034
3035static void diff_fill_sha1_info(struct diff_filespec *one)
3036{
3037        if (DIFF_FILE_VALID(one)) {
3038                if (!one->sha1_valid) {
3039                        struct stat st;
3040                        if (!strcmp(one->path, "-")) {
3041                                hashcpy(one->sha1, null_sha1);
3042                                return;
3043                        }
3044                        if (lstat(one->path, &st) < 0)
3045                                die_errno("stat '%s'", one->path);
3046                        if (index_path(one->sha1, one->path, &st, 0))
3047                                die("cannot hash %s", one->path);
3048                }
3049        }
3050        else
3051                hashclr(one->sha1);
3052}
3053
3054static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3055{
3056        /* Strip the prefix but do not molest /dev/null and absolute paths */
3057        if (*namep && **namep != '/') {
3058                *namep += prefix_length;
3059                if (**namep == '/')
3060                        ++*namep;
3061        }
3062        if (*otherp && **otherp != '/') {
3063                *otherp += prefix_length;
3064                if (**otherp == '/')
3065                        ++*otherp;
3066        }
3067}
3068
3069static void run_diff(struct diff_filepair *p, struct diff_options *o)
3070{
3071        const char *pgm = external_diff();
3072        struct strbuf msg;
3073        struct diff_filespec *one = p->one;
3074        struct diff_filespec *two = p->two;
3075        const char *name;
3076        const char *other;
3077        const char *attr_path;
3078
3079        name  = p->one->path;
3080        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3081        attr_path = name;
3082        if (o->prefix_length)
3083                strip_prefix(o->prefix_length, &name, &other);
3084
3085        if (DIFF_PAIR_UNMERGED(p)) {
3086                run_diff_cmd(pgm, name, NULL, attr_path,
3087                             NULL, NULL, NULL, o, p);
3088                return;
3089        }
3090
3091        diff_fill_sha1_info(one);
3092        diff_fill_sha1_info(two);
3093
3094        if (!pgm &&
3095            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3096            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3097                /*
3098                 * a filepair that changes between file and symlink
3099                 * needs to be split into deletion and creation.
3100                 */
3101                struct diff_filespec *null = alloc_filespec(two->path);
3102                run_diff_cmd(NULL, name, other, attr_path,
3103                             one, null, &msg, o, p);
3104                free(null);
3105                strbuf_release(&msg);
3106
3107                null = alloc_filespec(one->path);
3108                run_diff_cmd(NULL, name, other, attr_path,
3109                             null, two, &msg, o, p);
3110                free(null);
3111        }
3112        else
3113                run_diff_cmd(pgm, name, other, attr_path,
3114                             one, two, &msg, o, p);
3115
3116        strbuf_release(&msg);
3117}
3118
3119static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3120                         struct diffstat_t *diffstat)
3121{
3122        const char *name;
3123        const char *other;
3124        int complete_rewrite = 0;
3125
3126        if (DIFF_PAIR_UNMERGED(p)) {
3127                /* unmerged */
3128                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
3129                return;
3130        }
3131
3132        name = p->one->path;
3133        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3134
3135        if (o->prefix_length)
3136                strip_prefix(o->prefix_length, &name, &other);
3137
3138        diff_fill_sha1_info(p->one);
3139        diff_fill_sha1_info(p->two);
3140
3141        if (p->status == DIFF_STATUS_MODIFIED && p->score)
3142                complete_rewrite = 1;
3143        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
3144}
3145
3146static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3147{
3148        const char *name;
3149        const char *other;
3150        const char *attr_path;
3151
3152        if (DIFF_PAIR_UNMERGED(p)) {
3153                /* unmerged */
3154                return;
3155        }
3156
3157        name = p->one->path;
3158        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3159        attr_path = other ? other : name;
3160
3161        if (o->prefix_length)
3162                strip_prefix(o->prefix_length, &name, &other);
3163
3164        diff_fill_sha1_info(p->one);
3165        diff_fill_sha1_info(p->two);
3166
3167        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3168}
3169
3170void diff_setup(struct diff_options *options)
3171{
3172        memcpy(options, &default_diff_options, sizeof(*options));
3173
3174        options->file = stdout;
3175
3176        options->line_termination = '\n';
3177        options->break_opt = -1;
3178        options->rename_limit = -1;
3179        options->dirstat_permille = diff_dirstat_permille_default;
3180        options->context = 3;
3181        DIFF_OPT_SET(options, RENAME_EMPTY);
3182
3183        options->change = diff_change;
3184        options->add_remove = diff_addremove;
3185        options->use_color = diff_use_color_default;
3186        options->detect_rename = diff_detect_rename_default;
3187
3188        if (diff_no_prefix) {
3189                options->a_prefix = options->b_prefix = "";
3190        } else if (!diff_mnemonic_prefix) {
3191                options->a_prefix = "a/";
3192                options->b_prefix = "b/";
3193        }
3194}
3195
3196int diff_setup_done(struct diff_options *options)
3197{
3198        int count = 0;
3199
3200        if (options->output_format & DIFF_FORMAT_NAME)
3201                count++;
3202        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3203                count++;
3204        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3205                count++;
3206        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3207                count++;
3208        if (count > 1)
3209                die("--name-only, --name-status, --check and -s are mutually exclusive");
3210
3211        /*
3212         * Most of the time we can say "there are changes"
3213         * only by checking if there are changed paths, but
3214         * --ignore-whitespace* options force us to look
3215         * inside contents.
3216         */
3217
3218        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3219            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3220            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3221                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3222        else
3223                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3224
3225        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3226                options->detect_rename = DIFF_DETECT_COPY;
3227
3228        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3229                options->prefix = NULL;
3230        if (options->prefix)
3231                options->prefix_length = strlen(options->prefix);
3232        else
3233                options->prefix_length = 0;
3234
3235        if (options->output_format & (DIFF_FORMAT_NAME |
3236                                      DIFF_FORMAT_NAME_STATUS |
3237                                      DIFF_FORMAT_CHECKDIFF |
3238                                      DIFF_FORMAT_NO_OUTPUT))
3239                options->output_format &= ~(DIFF_FORMAT_RAW |
3240                                            DIFF_FORMAT_NUMSTAT |
3241                                            DIFF_FORMAT_DIFFSTAT |
3242                                            DIFF_FORMAT_SHORTSTAT |
3243                                            DIFF_FORMAT_DIRSTAT |
3244                                            DIFF_FORMAT_SUMMARY |
3245                                            DIFF_FORMAT_PATCH);
3246
3247        /*
3248         * These cases always need recursive; we do not drop caller-supplied
3249         * recursive bits for other formats here.
3250         */
3251        if (options->output_format & (DIFF_FORMAT_PATCH |
3252                                      DIFF_FORMAT_NUMSTAT |
3253                                      DIFF_FORMAT_DIFFSTAT |
3254                                      DIFF_FORMAT_SHORTSTAT |
3255                                      DIFF_FORMAT_DIRSTAT |
3256                                      DIFF_FORMAT_SUMMARY |
3257                                      DIFF_FORMAT_CHECKDIFF))
3258                DIFF_OPT_SET(options, RECURSIVE);
3259        /*
3260         * Also pickaxe would not work very well if you do not say recursive
3261         */
3262        if (options->pickaxe)
3263                DIFF_OPT_SET(options, RECURSIVE);
3264        /*
3265         * When patches are generated, submodules diffed against the work tree
3266         * must be checked for dirtiness too so it can be shown in the output
3267         */
3268        if (options->output_format & DIFF_FORMAT_PATCH)
3269                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3270
3271        if (options->detect_rename && options->rename_limit < 0)
3272                options->rename_limit = diff_rename_limit_default;
3273        if (options->setup & DIFF_SETUP_USE_CACHE) {
3274                if (!active_cache)
3275                        /* read-cache does not die even when it fails
3276                         * so it is safe for us to do this here.  Also
3277                         * it does not smudge active_cache or active_nr
3278                         * when it fails, so we do not have to worry about
3279                         * cleaning it up ourselves either.
3280                         */
3281                        read_cache();
3282        }
3283        if (options->abbrev <= 0 || 40 < options->abbrev)
3284                options->abbrev = 40; /* full */
3285
3286        /*
3287         * It does not make sense to show the first hit we happened
3288         * to have found.  It does not make sense not to return with
3289         * exit code in such a case either.
3290         */
3291        if (DIFF_OPT_TST(options, QUICK)) {
3292                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3293                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3294        }
3295
3296        return 0;
3297}
3298
3299static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3300{
3301        char c, *eq;
3302        int len;
3303
3304        if (*arg != '-')
3305                return 0;
3306        c = *++arg;
3307        if (!c)
3308                return 0;
3309        if (c == arg_short) {
3310                c = *++arg;
3311                if (!c)
3312                        return 1;
3313                if (val && isdigit(c)) {
3314                        char *end;
3315                        int n = strtoul(arg, &end, 10);
3316                        if (*end)
3317                                return 0;
3318                        *val = n;
3319                        return 1;
3320                }
3321                return 0;
3322        }
3323        if (c != '-')
3324                return 0;
3325        arg++;
3326        eq = strchr(arg, '=');
3327        if (eq)
3328                len = eq - arg;
3329        else
3330                len = strlen(arg);
3331        if (!len || strncmp(arg, arg_long, len))
3332                return 0;
3333        if (eq) {
3334                int n;
3335                char *end;
3336                if (!isdigit(*++eq))
3337                        return 0;
3338                n = strtoul(eq, &end, 10);
3339                if (*end)
3340                        return 0;
3341                *val = n;
3342        }
3343        return 1;
3344}
3345
3346static int diff_scoreopt_parse(const char *opt);
3347
3348static inline int short_opt(char opt, const char **argv,
3349                            const char **optarg)
3350{
3351        const char *arg = argv[0];
3352        if (arg[0] != '-' || arg[1] != opt)
3353                return 0;
3354        if (arg[2] != '\0') {
3355                *optarg = arg + 2;
3356                return 1;
3357        }
3358        if (!argv[1])
3359                die("Option '%c' requires a value", opt);
3360        *optarg = argv[1];
3361        return 2;
3362}
3363
3364int parse_long_opt(const char *opt, const char **argv,
3365                   const char **optarg)
3366{
3367        const char *arg = argv[0];
3368        if (arg[0] != '-' || arg[1] != '-')
3369                return 0;
3370        arg += strlen("--");
3371        if (prefixcmp(arg, opt))
3372                return 0;
3373        arg += strlen(opt);
3374        if (*arg == '=') { /* sticked form: --option=value */
3375                *optarg = arg + 1;
3376                return 1;
3377        }
3378        if (*arg != '\0')
3379                return 0;
3380        /* separate form: --option value */
3381        if (!argv[1])
3382                die("Option '--%s' requires a value", opt);
3383        *optarg = argv[1];
3384        return 2;
3385}
3386
3387static int stat_opt(struct diff_options *options, const char **av)
3388{
3389        const char *arg = av[0];
3390        char *end;
3391        int width = options->stat_width;
3392        int name_width = options->stat_name_width;
3393        int graph_width = options->stat_graph_width;
3394        int count = options->stat_count;
3395        int argcount = 1;
3396
3397        arg += strlen("--stat");
3398        end = (char *)arg;
3399
3400        switch (*arg) {
3401        case '-':
3402                if (!prefixcmp(arg, "-width")) {
3403                        arg += strlen("-width");
3404                        if (*arg == '=')
3405                                width = strtoul(arg + 1, &end, 10);
3406                        else if (!*arg && !av[1])
3407                                die("Option '--stat-width' requires a value");
3408                        else if (!*arg) {
3409                                width = strtoul(av[1], &end, 10);
3410                                argcount = 2;
3411                        }
3412                } else if (!prefixcmp(arg, "-name-width")) {
3413                        arg += strlen("-name-width");
3414                        if (*arg == '=')
3415                                name_width = strtoul(arg + 1, &end, 10);
3416                        else if (!*arg && !av[1])
3417                                die("Option '--stat-name-width' requires a value");
3418                        else if (!*arg) {
3419                                name_width = strtoul(av[1], &end, 10);
3420                                argcount = 2;
3421                        }
3422                } else if (!prefixcmp(arg, "-graph-width")) {
3423                        arg += strlen("-graph-width");
3424                        if (*arg == '=')
3425                                graph_width = strtoul(arg + 1, &end, 10);
3426                        else if (!*arg && !av[1])
3427                                die("Option '--stat-graph-width' requires a value");
3428                        else if (!*arg) {
3429                                graph_width = strtoul(av[1], &end, 10);
3430                                argcount = 2;
3431                        }
3432                } else if (!prefixcmp(arg, "-count")) {
3433                        arg += strlen("-count");
3434                        if (*arg == '=')
3435                                count = strtoul(arg + 1, &end, 10);
3436                        else if (!*arg && !av[1])
3437                                die("Option '--stat-count' requires a value");
3438                        else if (!*arg) {
3439                                count = strtoul(av[1], &end, 10);
3440                                argcount = 2;
3441                        }
3442                }
3443                break;
3444        case '=':
3445                width = strtoul(arg+1, &end, 10);
3446                if (*end == ',')
3447                        name_width = strtoul(end+1, &end, 10);
3448                if (*end == ',')
3449                        count = strtoul(end+1, &end, 10);
3450        }
3451
3452        /* Important! This checks all the error cases! */
3453        if (*end)
3454                return 0;
3455        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3456        options->stat_name_width = name_width;
3457        options->stat_graph_width = graph_width;
3458        options->stat_width = width;
3459        options->stat_count = count;
3460        return argcount;
3461}
3462
3463static int parse_dirstat_opt(struct diff_options *options, const char *params)
3464{
3465        struct strbuf errmsg = STRBUF_INIT;
3466        if (parse_dirstat_params(options, params, &errmsg))
3467                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3468                    errmsg.buf);
3469        strbuf_release(&errmsg);
3470        /*
3471         * The caller knows a dirstat-related option is given from the command
3472         * line; allow it to say "return this_function();"
3473         */
3474        options->output_format |= DIFF_FORMAT_DIRSTAT;
3475        return 1;
3476}
3477
3478int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3479{
3480        const char *arg = av[0];
3481        const char *optarg;
3482        int argcount;
3483
3484        /* Output format options */
3485        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3486                options->output_format |= DIFF_FORMAT_PATCH;
3487        else if (opt_arg(arg, 'U', "unified", &options->context))
3488                options->output_format |= DIFF_FORMAT_PATCH;
3489        else if (!strcmp(arg, "--raw"))
3490                options->output_format |= DIFF_FORMAT_RAW;
3491        else if (!strcmp(arg, "--patch-with-raw"))
3492                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3493        else if (!strcmp(arg, "--numstat"))
3494                options->output_format |= DIFF_FORMAT_NUMSTAT;
3495        else if (!strcmp(arg, "--shortstat"))
3496                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3497        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3498                return parse_dirstat_opt(options, "");
3499        else if (!prefixcmp(arg, "-X"))
3500                return parse_dirstat_opt(options, arg + 2);
3501        else if (!prefixcmp(arg, "--dirstat="))
3502                return parse_dirstat_opt(options, arg + 10);
3503        else if (!strcmp(arg, "--cumulative"))
3504                return parse_dirstat_opt(options, "cumulative");
3505        else if (!strcmp(arg, "--dirstat-by-file"))
3506                return parse_dirstat_opt(options, "files");
3507        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3508                parse_dirstat_opt(options, "files");
3509                return parse_dirstat_opt(options, arg + 18);
3510        }
3511        else if (!strcmp(arg, "--check"))
3512                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3513        else if (!strcmp(arg, "--summary"))
3514                options->output_format |= DIFF_FORMAT_SUMMARY;
3515        else if (!strcmp(arg, "--patch-with-stat"))
3516                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3517        else if (!strcmp(arg, "--name-only"))
3518                options->output_format |= DIFF_FORMAT_NAME;
3519        else if (!strcmp(arg, "--name-status"))
3520                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3521        else if (!strcmp(arg, "-s"))
3522                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3523        else if (!prefixcmp(arg, "--stat"))
3524                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3525                return stat_opt(options, av);
3526
3527        /* renames options */
3528        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3529                 !strcmp(arg, "--break-rewrites")) {
3530                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3531                        return error("invalid argument to -B: %s", arg+2);
3532        }
3533        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3534                 !strcmp(arg, "--find-renames")) {
3535                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3536                        return error("invalid argument to -M: %s", arg+2);
3537                options->detect_rename = DIFF_DETECT_RENAME;
3538        }
3539        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3540                options->irreversible_delete = 1;
3541        }
3542        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3543                 !strcmp(arg, "--find-copies")) {
3544                if (options->detect_rename == DIFF_DETECT_COPY)
3545                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3546                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3547                        return error("invalid argument to -C: %s", arg+2);
3548                options->detect_rename = DIFF_DETECT_COPY;
3549        }
3550        else if (!strcmp(arg, "--no-renames"))
3551                options->detect_rename = 0;
3552        else if (!strcmp(arg, "--rename-empty"))
3553                DIFF_OPT_SET(options, RENAME_EMPTY);
3554        else if (!strcmp(arg, "--no-rename-empty"))
3555                DIFF_OPT_CLR(options, RENAME_EMPTY);
3556        else if (!strcmp(arg, "--relative"))
3557                DIFF_OPT_SET(options, RELATIVE_NAME);
3558        else if (!prefixcmp(arg, "--relative=")) {
3559                DIFF_OPT_SET(options, RELATIVE_NAME);
3560                options->prefix = arg + 11;
3561        }
3562
3563        /* xdiff options */
3564        else if (!strcmp(arg, "--minimal"))
3565                DIFF_XDL_SET(options, NEED_MINIMAL);
3566        else if (!strcmp(arg, "--no-minimal"))
3567                DIFF_XDL_CLR(options, NEED_MINIMAL);
3568        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3569                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3570        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3571                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3572        else if (!strcmp(arg, "--ignore-space-at-eol"))
3573                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3574        else if (!strcmp(arg, "--patience"))
3575                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3576        else if (!strcmp(arg, "--histogram"))
3577                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3578
3579        /* flags options */
3580        else if (!strcmp(arg, "--binary")) {
3581                options->output_format |= DIFF_FORMAT_PATCH;
3582                DIFF_OPT_SET(options, BINARY);
3583        }
3584        else if (!strcmp(arg, "--full-index"))
3585                DIFF_OPT_SET(options, FULL_INDEX);
3586        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3587                DIFF_OPT_SET(options, TEXT);
3588        else if (!strcmp(arg, "-R"))
3589                DIFF_OPT_SET(options, REVERSE_DIFF);
3590        else if (!strcmp(arg, "--find-copies-harder"))
3591                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3592        else if (!strcmp(arg, "--follow"))
3593                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3594        else if (!strcmp(arg, "--color"))
3595                options->use_color = 1;
3596        else if (!prefixcmp(arg, "--color=")) {
3597                int value = git_config_colorbool(NULL, arg+8);
3598                if (value < 0)
3599                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3600                options->use_color = value;
3601        }
3602        else if (!strcmp(arg, "--no-color"))
3603                options->use_color = 0;
3604        else if (!strcmp(arg, "--color-words")) {
3605                options->use_color = 1;
3606                options->word_diff = DIFF_WORDS_COLOR;
3607        }
3608        else if (!prefixcmp(arg, "--color-words=")) {
3609                options->use_color = 1;
3610                options->word_diff = DIFF_WORDS_COLOR;
3611                options->word_regex = arg + 14;
3612        }
3613        else if (!strcmp(arg, "--word-diff")) {
3614                if (options->word_diff == DIFF_WORDS_NONE)
3615                        options->word_diff = DIFF_WORDS_PLAIN;
3616        }
3617        else if (!prefixcmp(arg, "--word-diff=")) {
3618                const char *type = arg + 12;
3619                if (!strcmp(type, "plain"))
3620                        options->word_diff = DIFF_WORDS_PLAIN;
3621                else if (!strcmp(type, "color")) {
3622                        options->use_color = 1;
3623                        options->word_diff = DIFF_WORDS_COLOR;
3624                }
3625                else if (!strcmp(type, "porcelain"))
3626                        options->word_diff = DIFF_WORDS_PORCELAIN;
3627                else if (!strcmp(type, "none"))
3628                        options->word_diff = DIFF_WORDS_NONE;
3629                else
3630                        die("bad --word-diff argument: %s", type);
3631        }
3632        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3633                if (options->word_diff == DIFF_WORDS_NONE)
3634                        options->word_diff = DIFF_WORDS_PLAIN;
3635                options->word_regex = optarg;
3636                return argcount;
3637        }
3638        else if (!strcmp(arg, "--exit-code"))
3639                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3640        else if (!strcmp(arg, "--quiet"))
3641                DIFF_OPT_SET(options, QUICK);
3642        else if (!strcmp(arg, "--ext-diff"))
3643                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3644        else if (!strcmp(arg, "--no-ext-diff"))
3645                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3646        else if (!strcmp(arg, "--textconv"))
3647                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3648        else if (!strcmp(arg, "--no-textconv"))
3649                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3650        else if (!strcmp(arg, "--ignore-submodules")) {
3651                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3652                handle_ignore_submodules_arg(options, "all");
3653        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3654                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3655                handle_ignore_submodules_arg(options, arg + 20);
3656        } else if (!strcmp(arg, "--submodule"))
3657                DIFF_OPT_SET(options, SUBMODULE_LOG);
3658        else if (!prefixcmp(arg, "--submodule=")) {
3659                if (!strcmp(arg + 12, "log"))
3660                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3661        }
3662
3663        /* misc options */
3664        else if (!strcmp(arg, "-z"))
3665                options->line_termination = 0;
3666        else if ((argcount = short_opt('l', av, &optarg))) {
3667                options->rename_limit = strtoul(optarg, NULL, 10);
3668                return argcount;
3669        }
3670        else if ((argcount = short_opt('S', av, &optarg))) {
3671                options->pickaxe = optarg;
3672                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3673                return argcount;
3674        } else if ((argcount = short_opt('G', av, &optarg))) {
3675                options->pickaxe = optarg;
3676                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3677                return argcount;
3678        }
3679        else if (!strcmp(arg, "--pickaxe-all"))
3680                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3681        else if (!strcmp(arg, "--pickaxe-regex"))
3682                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3683        else if ((argcount = short_opt('O', av, &optarg))) {
3684                options->orderfile = optarg;
3685                return argcount;
3686        }
3687        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3688                options->filter = optarg;
3689                return argcount;
3690        }
3691        else if (!strcmp(arg, "--abbrev"))
3692                options->abbrev = DEFAULT_ABBREV;
3693        else if (!prefixcmp(arg, "--abbrev=")) {
3694                options->abbrev = strtoul(arg + 9, NULL, 10);
3695                if (options->abbrev < MINIMUM_ABBREV)
3696                        options->abbrev = MINIMUM_ABBREV;
3697                else if (40 < options->abbrev)
3698                        options->abbrev = 40;
3699        }
3700        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3701                options->a_prefix = optarg;
3702                return argcount;
3703        }
3704        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3705                options->b_prefix = optarg;
3706                return argcount;
3707        }
3708        else if (!strcmp(arg, "--no-prefix"))
3709                options->a_prefix = options->b_prefix = "";
3710        else if (opt_arg(arg, '\0', "inter-hunk-context",
3711                         &options->interhunkcontext))
3712                ;
3713        else if (!strcmp(arg, "-W"))
3714                DIFF_OPT_SET(options, FUNCCONTEXT);
3715        else if (!strcmp(arg, "--function-context"))
3716                DIFF_OPT_SET(options, FUNCCONTEXT);
3717        else if (!strcmp(arg, "--no-function-context"))
3718                DIFF_OPT_CLR(options, FUNCCONTEXT);
3719        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3720                options->file = fopen(optarg, "w");
3721                if (!options->file)
3722                        die_errno("Could not open '%s'", optarg);
3723                options->close_file = 1;
3724                return argcount;
3725        } else
3726                return 0;
3727        return 1;
3728}
3729
3730int parse_rename_score(const char **cp_p)
3731{
3732        unsigned long num, scale;
3733        int ch, dot;
3734        const char *cp = *cp_p;
3735
3736        num = 0;
3737        scale = 1;
3738        dot = 0;
3739        for (;;) {
3740                ch = *cp;
3741                if ( !dot && ch == '.' ) {
3742                        scale = 1;
3743                        dot = 1;
3744                } else if ( ch == '%' ) {
3745                        scale = dot ? scale*100 : 100;
3746                        cp++;   /* % is always at the end */
3747                        break;
3748                } else if ( ch >= '0' && ch <= '9' ) {
3749                        if ( scale < 100000 ) {
3750                                scale *= 10;
3751                                num = (num*10) + (ch-'0');
3752                        }
3753                } else {
3754                        break;
3755                }
3756                cp++;
3757        }
3758        *cp_p = cp;
3759
3760        /* user says num divided by scale and we say internally that
3761         * is MAX_SCORE * num / scale.
3762         */
3763        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3764}
3765
3766static int diff_scoreopt_parse(const char *opt)
3767{
3768        int opt1, opt2, cmd;
3769
3770        if (*opt++ != '-')
3771                return -1;
3772        cmd = *opt++;
3773        if (cmd == '-') {
3774                /* convert the long-form arguments into short-form versions */
3775                if (!prefixcmp(opt, "break-rewrites")) {
3776                        opt += strlen("break-rewrites");
3777                        if (*opt == 0 || *opt++ == '=')
3778                                cmd = 'B';
3779                } else if (!prefixcmp(opt, "find-copies")) {
3780                        opt += strlen("find-copies");
3781                        if (*opt == 0 || *opt++ == '=')
3782                                cmd = 'C';
3783                } else if (!prefixcmp(opt, "find-renames")) {
3784                        opt += strlen("find-renames");
3785                        if (*opt == 0 || *opt++ == '=')
3786                                cmd = 'M';
3787                }
3788        }
3789        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3790                return -1; /* that is not a -M, -C nor -B option */
3791
3792        opt1 = parse_rename_score(&opt);
3793        if (cmd != 'B')
3794                opt2 = 0;
3795        else {
3796                if (*opt == 0)
3797                        opt2 = 0;
3798                else if (*opt != '/')
3799                        return -1; /* we expect -B80/99 or -B80 */
3800                else {
3801                        opt++;
3802                        opt2 = parse_rename_score(&opt);
3803                }
3804        }
3805        if (*opt != 0)
3806                return -1;
3807        return opt1 | (opt2 << 16);
3808}
3809
3810struct diff_queue_struct diff_queued_diff;
3811
3812void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3813{
3814        if (queue->alloc <= queue->nr) {
3815                queue->alloc = alloc_nr(queue->alloc);
3816                queue->queue = xrealloc(queue->queue,
3817                                        sizeof(dp) * queue->alloc);
3818        }
3819        queue->queue[queue->nr++] = dp;
3820}
3821
3822struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3823                                 struct diff_filespec *one,
3824                                 struct diff_filespec *two)
3825{
3826        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3827        dp->one = one;
3828        dp->two = two;
3829        if (queue)
3830                diff_q(queue, dp);
3831        return dp;
3832}
3833
3834void diff_free_filepair(struct diff_filepair *p)
3835{
3836        free_filespec(p->one);
3837        free_filespec(p->two);
3838        free(p);
3839}
3840
3841/* This is different from find_unique_abbrev() in that
3842 * it stuffs the result with dots for alignment.
3843 */
3844const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3845{
3846        int abblen;
3847        const char *abbrev;
3848        if (len == 40)
3849                return sha1_to_hex(sha1);
3850
3851        abbrev = find_unique_abbrev(sha1, len);
3852        abblen = strlen(abbrev);
3853        if (abblen < 37) {
3854                static char hex[41];
3855                if (len < abblen && abblen <= len + 2)
3856                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3857                else
3858                        sprintf(hex, "%s...", abbrev);
3859                return hex;
3860        }
3861        return sha1_to_hex(sha1);
3862}
3863
3864static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3865{
3866        int line_termination = opt->line_termination;
3867        int inter_name_termination = line_termination ? '\t' : '\0';
3868        if (opt->output_prefix) {
3869                struct strbuf *msg = NULL;
3870                msg = opt->output_prefix(opt, opt->output_prefix_data);
3871                fprintf(opt->file, "%s", msg->buf);
3872        }
3873
3874        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3875                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3876                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3877                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3878        }
3879        if (p->score) {
3880                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3881                        inter_name_termination);
3882        } else {
3883                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3884        }
3885
3886        if (p->status == DIFF_STATUS_COPIED ||
3887            p->status == DIFF_STATUS_RENAMED) {
3888                const char *name_a, *name_b;
3889                name_a = p->one->path;
3890                name_b = p->two->path;
3891                strip_prefix(opt->prefix_length, &name_a, &name_b);
3892                write_name_quoted(name_a, opt->file, inter_name_termination);
3893                write_name_quoted(name_b, opt->file, line_termination);
3894        } else {
3895                const char *name_a, *name_b;
3896                name_a = p->one->mode ? p->one->path : p->two->path;
3897                name_b = NULL;
3898                strip_prefix(opt->prefix_length, &name_a, &name_b);
3899                write_name_quoted(name_a, opt->file, line_termination);
3900        }
3901}
3902
3903int diff_unmodified_pair(struct diff_filepair *p)
3904{
3905        /* This function is written stricter than necessary to support
3906         * the currently implemented transformers, but the idea is to
3907         * let transformers to produce diff_filepairs any way they want,
3908         * and filter and clean them up here before producing the output.
3909         */
3910        struct diff_filespec *one = p->one, *two = p->two;
3911
3912        if (DIFF_PAIR_UNMERGED(p))
3913                return 0; /* unmerged is interesting */
3914
3915        /* deletion, addition, mode or type change
3916         * and rename are all interesting.
3917         */
3918        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3919            DIFF_PAIR_MODE_CHANGED(p) ||
3920            strcmp(one->path, two->path))
3921                return 0;
3922
3923        /* both are valid and point at the same path.  that is, we are
3924         * dealing with a change.
3925         */
3926        if (one->sha1_valid && two->sha1_valid &&
3927            !hashcmp(one->sha1, two->sha1) &&
3928            !one->dirty_submodule && !two->dirty_submodule)
3929                return 1; /* no change */
3930        if (!one->sha1_valid && !two->sha1_valid)
3931                return 1; /* both look at the same file on the filesystem. */
3932        return 0;
3933}
3934
3935static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3936{
3937        if (diff_unmodified_pair(p))
3938                return;
3939
3940        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3941            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3942                return; /* no tree diffs in patch format */
3943
3944        run_diff(p, o);
3945}
3946
3947static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3948                            struct diffstat_t *diffstat)
3949{
3950        if (diff_unmodified_pair(p))
3951                return;
3952
3953        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3954            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3955                return; /* no useful stat for tree diffs */
3956
3957        run_diffstat(p, o, diffstat);
3958}
3959
3960static void diff_flush_checkdiff(struct diff_filepair *p,
3961                struct diff_options *o)
3962{
3963        if (diff_unmodified_pair(p))
3964                return;
3965
3966        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3967            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3968                return; /* nothing to check in tree diffs */
3969
3970        run_checkdiff(p, o);
3971}
3972
3973int diff_queue_is_empty(void)
3974{
3975        struct diff_queue_struct *q = &diff_queued_diff;
3976        int i;
3977        for (i = 0; i < q->nr; i++)
3978                if (!diff_unmodified_pair(q->queue[i]))
3979                        return 0;
3980        return 1;
3981}
3982
3983#if DIFF_DEBUG
3984void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3985{
3986        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3987                x, one ? one : "",
3988                s->path,
3989                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3990                s->mode,
3991                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3992        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3993                x, one ? one : "",
3994                s->size, s->xfrm_flags);
3995}
3996
3997void diff_debug_filepair(const struct diff_filepair *p, int i)
3998{
3999        diff_debug_filespec(p->one, i, "one");
4000        diff_debug_filespec(p->two, i, "two");
4001        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4002                p->score, p->status ? p->status : '?',
4003                p->one->rename_used, p->broken_pair);
4004}
4005
4006void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4007{
4008        int i;
4009        if (msg)
4010                fprintf(stderr, "%s\n", msg);
4011        fprintf(stderr, "q->nr = %d\n", q->nr);
4012        for (i = 0; i < q->nr; i++) {
4013                struct diff_filepair *p = q->queue[i];
4014                diff_debug_filepair(p, i);
4015        }
4016}
4017#endif
4018
4019static void diff_resolve_rename_copy(void)
4020{
4021        int i;
4022        struct diff_filepair *p;
4023        struct diff_queue_struct *q = &diff_queued_diff;
4024
4025        diff_debug_queue("resolve-rename-copy", q);
4026
4027        for (i = 0; i < q->nr; i++) {
4028                p = q->queue[i];
4029                p->status = 0; /* undecided */
4030                if (DIFF_PAIR_UNMERGED(p))
4031                        p->status = DIFF_STATUS_UNMERGED;
4032                else if (!DIFF_FILE_VALID(p->one))
4033                        p->status = DIFF_STATUS_ADDED;
4034                else if (!DIFF_FILE_VALID(p->two))
4035                        p->status = DIFF_STATUS_DELETED;
4036                else if (DIFF_PAIR_TYPE_CHANGED(p))
4037                        p->status = DIFF_STATUS_TYPE_CHANGED;
4038
4039                /* from this point on, we are dealing with a pair
4040                 * whose both sides are valid and of the same type, i.e.
4041                 * either in-place edit or rename/copy edit.
4042                 */
4043                else if (DIFF_PAIR_RENAME(p)) {
4044                        /*
4045                         * A rename might have re-connected a broken
4046                         * pair up, causing the pathnames to be the
4047                         * same again. If so, that's not a rename at
4048                         * all, just a modification..
4049                         *
4050                         * Otherwise, see if this source was used for
4051                         * multiple renames, in which case we decrement
4052                         * the count, and call it a copy.
4053                         */
4054                        if (!strcmp(p->one->path, p->two->path))
4055                                p->status = DIFF_STATUS_MODIFIED;
4056                        else if (--p->one->rename_used > 0)
4057                                p->status = DIFF_STATUS_COPIED;
4058                        else
4059                                p->status = DIFF_STATUS_RENAMED;
4060                }
4061                else if (hashcmp(p->one->sha1, p->two->sha1) ||
4062                         p->one->mode != p->two->mode ||
4063                         p->one->dirty_submodule ||
4064                         p->two->dirty_submodule ||
4065                         is_null_sha1(p->one->sha1))
4066                        p->status = DIFF_STATUS_MODIFIED;
4067                else {
4068                        /* This is a "no-change" entry and should not
4069                         * happen anymore, but prepare for broken callers.
4070                         */
4071                        error("feeding unmodified %s to diffcore",
4072                              p->one->path);
4073                        p->status = DIFF_STATUS_UNKNOWN;
4074                }
4075        }
4076        diff_debug_queue("resolve-rename-copy done", q);
4077}
4078
4079static int check_pair_status(struct diff_filepair *p)
4080{
4081        switch (p->status) {
4082        case DIFF_STATUS_UNKNOWN:
4083                return 0;
4084        case 0:
4085                die("internal error in diff-resolve-rename-copy");
4086        default:
4087                return 1;
4088        }
4089}
4090
4091static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4092{
4093        int fmt = opt->output_format;
4094
4095        if (fmt & DIFF_FORMAT_CHECKDIFF)
4096                diff_flush_checkdiff(p, opt);
4097        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4098                diff_flush_raw(p, opt);
4099        else if (fmt & DIFF_FORMAT_NAME) {
4100                const char *name_a, *name_b;
4101                name_a = p->two->path;
4102                name_b = NULL;
4103                strip_prefix(opt->prefix_length, &name_a, &name_b);
4104                write_name_quoted(name_a, opt->file, opt->line_termination);
4105        }
4106}
4107
4108static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4109{
4110        if (fs->mode)
4111                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4112        else
4113                fprintf(file, " %s ", newdelete);
4114        write_name_quoted(fs->path, file, '\n');
4115}
4116
4117
4118static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4119                const char *line_prefix)
4120{
4121        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4122                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4123                        p->two->mode, show_name ? ' ' : '\n');
4124                if (show_name) {
4125                        write_name_quoted(p->two->path, file, '\n');
4126                }
4127        }
4128}
4129
4130static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4131                        const char *line_prefix)
4132{
4133        char *names = pprint_rename(p->one->path, p->two->path);
4134
4135        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4136        free(names);
4137        show_mode_change(file, p, 0, line_prefix);
4138}
4139
4140static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4141{
4142        FILE *file = opt->file;
4143        char *line_prefix = "";
4144
4145        if (opt->output_prefix) {
4146                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
4147                line_prefix = buf->buf;
4148        }
4149
4150        switch(p->status) {
4151        case DIFF_STATUS_DELETED:
4152                fputs(line_prefix, file);
4153                show_file_mode_name(file, "delete", p->one);
4154                break;
4155        case DIFF_STATUS_ADDED:
4156                fputs(line_prefix, file);
4157                show_file_mode_name(file, "create", p->two);
4158                break;
4159        case DIFF_STATUS_COPIED:
4160                fputs(line_prefix, file);
4161                show_rename_copy(file, "copy", p, line_prefix);
4162                break;
4163        case DIFF_STATUS_RENAMED:
4164                fputs(line_prefix, file);
4165                show_rename_copy(file, "rename", p, line_prefix);
4166                break;
4167        default:
4168                if (p->score) {
4169                        fprintf(file, "%s rewrite ", line_prefix);
4170                        write_name_quoted(p->two->path, file, ' ');
4171                        fprintf(file, "(%d%%)\n", similarity_index(p));
4172                }
4173                show_mode_change(file, p, !p->score, line_prefix);
4174                break;
4175        }
4176}
4177
4178struct patch_id_t {
4179        git_SHA_CTX *ctx;
4180        int patchlen;
4181};
4182
4183static int remove_space(char *line, int len)
4184{
4185        int i;
4186        char *dst = line;
4187        unsigned char c;
4188
4189        for (i = 0; i < len; i++)
4190                if (!isspace((c = line[i])))
4191                        *dst++ = c;
4192
4193        return dst - line;
4194}
4195
4196static void patch_id_consume(void *priv, char *line, unsigned long len)
4197{
4198        struct patch_id_t *data = priv;
4199        int new_len;
4200
4201        /* Ignore line numbers when computing the SHA1 of the patch */
4202        if (!prefixcmp(line, "@@ -"))
4203                return;
4204
4205        new_len = remove_space(line, len);
4206
4207        git_SHA1_Update(data->ctx, line, new_len);
4208        data->patchlen += new_len;
4209}
4210
4211/* returns 0 upon success, and writes result into sha1 */
4212static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4213{
4214        struct diff_queue_struct *q = &diff_queued_diff;
4215        int i;
4216        git_SHA_CTX ctx;
4217        struct patch_id_t data;
4218        char buffer[PATH_MAX * 4 + 20];
4219
4220        git_SHA1_Init(&ctx);
4221        memset(&data, 0, sizeof(struct patch_id_t));
4222        data.ctx = &ctx;
4223
4224        for (i = 0; i < q->nr; i++) {
4225                xpparam_t xpp;
4226                xdemitconf_t xecfg;
4227                mmfile_t mf1, mf2;
4228                struct diff_filepair *p = q->queue[i];
4229                int len1, len2;
4230
4231                memset(&xpp, 0, sizeof(xpp));
4232                memset(&xecfg, 0, sizeof(xecfg));
4233                if (p->status == 0)
4234                        return error("internal diff status error");
4235                if (p->status == DIFF_STATUS_UNKNOWN)
4236                        continue;
4237                if (diff_unmodified_pair(p))
4238                        continue;
4239                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4240                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4241                        continue;
4242                if (DIFF_PAIR_UNMERGED(p))
4243                        continue;
4244
4245                diff_fill_sha1_info(p->one);
4246                diff_fill_sha1_info(p->two);
4247                if (fill_mmfile(&mf1, p->one) < 0 ||
4248                                fill_mmfile(&mf2, p->two) < 0)
4249                        return error("unable to read files to diff");
4250
4251                len1 = remove_space(p->one->path, strlen(p->one->path));
4252                len2 = remove_space(p->two->path, strlen(p->two->path));
4253                if (p->one->mode == 0)
4254                        len1 = snprintf(buffer, sizeof(buffer),
4255                                        "diff--gita/%.*sb/%.*s"
4256                                        "newfilemode%06o"
4257                                        "---/dev/null"
4258                                        "+++b/%.*s",
4259                                        len1, p->one->path,
4260                                        len2, p->two->path,
4261                                        p->two->mode,
4262                                        len2, p->two->path);
4263                else if (p->two->mode == 0)
4264                        len1 = snprintf(buffer, sizeof(buffer),
4265                                        "diff--gita/%.*sb/%.*s"
4266                                        "deletedfilemode%06o"
4267                                        "---a/%.*s"
4268                                        "+++/dev/null",
4269                                        len1, p->one->path,
4270                                        len2, p->two->path,
4271                                        p->one->mode,
4272                                        len1, p->one->path);
4273                else
4274                        len1 = snprintf(buffer, sizeof(buffer),
4275                                        "diff--gita/%.*sb/%.*s"
4276                                        "---a/%.*s"
4277                                        "+++b/%.*s",
4278                                        len1, p->one->path,
4279                                        len2, p->two->path,
4280                                        len1, p->one->path,
4281                                        len2, p->two->path);
4282                git_SHA1_Update(&ctx, buffer, len1);
4283
4284                if (diff_filespec_is_binary(p->one) ||
4285                    diff_filespec_is_binary(p->two)) {
4286                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4287                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4288                        continue;
4289                }
4290
4291                xpp.flags = 0;
4292                xecfg.ctxlen = 3;
4293                xecfg.flags = 0;
4294                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4295                              &xpp, &xecfg);
4296        }
4297
4298        git_SHA1_Final(sha1, &ctx);
4299        return 0;
4300}
4301
4302int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4303{
4304        struct diff_queue_struct *q = &diff_queued_diff;
4305        int i;
4306        int result = diff_get_patch_id(options, sha1);
4307
4308        for (i = 0; i < q->nr; i++)
4309                diff_free_filepair(q->queue[i]);
4310
4311        free(q->queue);
4312        DIFF_QUEUE_CLEAR(q);
4313
4314        return result;
4315}
4316
4317static int is_summary_empty(const struct diff_queue_struct *q)
4318{
4319        int i;
4320
4321        for (i = 0; i < q->nr; i++) {
4322                const struct diff_filepair *p = q->queue[i];
4323
4324                switch (p->status) {
4325                case DIFF_STATUS_DELETED:
4326                case DIFF_STATUS_ADDED:
4327                case DIFF_STATUS_COPIED:
4328                case DIFF_STATUS_RENAMED:
4329                        return 0;
4330                default:
4331                        if (p->score)
4332                                return 0;
4333                        if (p->one->mode && p->two->mode &&
4334                            p->one->mode != p->two->mode)
4335                                return 0;
4336                        break;
4337                }
4338        }
4339        return 1;
4340}
4341
4342static const char rename_limit_warning[] =
4343"inexact rename detection was skipped due to too many files.";
4344
4345static const char degrade_cc_to_c_warning[] =
4346"only found copies from modified paths due to too many files.";
4347
4348static const char rename_limit_advice[] =
4349"you may want to set your %s variable to at least "
4350"%d and retry the command.";
4351
4352void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4353{
4354        if (degraded_cc)
4355                warning(degrade_cc_to_c_warning);
4356        else if (needed)
4357                warning(rename_limit_warning);
4358        else
4359                return;
4360        if (0 < needed && needed < 32767)
4361                warning(rename_limit_advice, varname, needed);
4362}
4363
4364void diff_flush(struct diff_options *options)
4365{
4366        struct diff_queue_struct *q = &diff_queued_diff;
4367        int i, output_format = options->output_format;
4368        int separator = 0;
4369        int dirstat_by_line = 0;
4370
4371        /*
4372         * Order: raw, stat, summary, patch
4373         * or:    name/name-status/checkdiff (other bits clear)
4374         */
4375        if (!q->nr)
4376                goto free_queue;
4377
4378        if (output_format & (DIFF_FORMAT_RAW |
4379                             DIFF_FORMAT_NAME |
4380                             DIFF_FORMAT_NAME_STATUS |
4381                             DIFF_FORMAT_CHECKDIFF)) {
4382                for (i = 0; i < q->nr; i++) {
4383                        struct diff_filepair *p = q->queue[i];
4384                        if (check_pair_status(p))
4385                                flush_one_pair(p, options);
4386                }
4387                separator++;
4388        }
4389
4390        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4391                dirstat_by_line = 1;
4392
4393        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4394            dirstat_by_line) {
4395                struct diffstat_t diffstat;
4396
4397                memset(&diffstat, 0, sizeof(struct diffstat_t));
4398                for (i = 0; i < q->nr; i++) {
4399                        struct diff_filepair *p = q->queue[i];
4400                        if (check_pair_status(p))
4401                                diff_flush_stat(p, options, &diffstat);
4402                }
4403                if (output_format & DIFF_FORMAT_NUMSTAT)
4404                        show_numstat(&diffstat, options);
4405                if (output_format & DIFF_FORMAT_DIFFSTAT)
4406                        show_stats(&diffstat, options);
4407                if (output_format & DIFF_FORMAT_SHORTSTAT)
4408                        show_shortstats(&diffstat, options);
4409                if (output_format & DIFF_FORMAT_DIRSTAT)
4410                        show_dirstat_by_line(&diffstat, options);
4411                free_diffstat_info(&diffstat);
4412                separator++;
4413        }
4414        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4415                show_dirstat(options);
4416
4417        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4418                for (i = 0; i < q->nr; i++) {
4419                        diff_summary(options, q->queue[i]);
4420                }
4421                separator++;
4422        }
4423
4424        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4425            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4426            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4427                /*
4428                 * run diff_flush_patch for the exit status. setting
4429                 * options->file to /dev/null should be safe, becaue we
4430                 * aren't supposed to produce any output anyway.
4431                 */
4432                if (options->close_file)
4433                        fclose(options->file);
4434                options->file = fopen("/dev/null", "w");
4435                if (!options->file)
4436                        die_errno("Could not open /dev/null");
4437                options->close_file = 1;
4438                for (i = 0; i < q->nr; i++) {
4439                        struct diff_filepair *p = q->queue[i];
4440                        if (check_pair_status(p))
4441                                diff_flush_patch(p, options);
4442                        if (options->found_changes)
4443                                break;
4444                }
4445        }
4446
4447        if (output_format & DIFF_FORMAT_PATCH) {
4448                if (separator) {
4449                        if (options->output_prefix) {
4450                                struct strbuf *msg = NULL;
4451                                msg = options->output_prefix(options,
4452                                        options->output_prefix_data);
4453                                fwrite(msg->buf, msg->len, 1, stdout);
4454                        }
4455                        putc(options->line_termination, options->file);
4456                        if (options->stat_sep) {
4457                                /* attach patch instead of inline */
4458                                fputs(options->stat_sep, options->file);
4459                        }
4460                }
4461
4462                for (i = 0; i < q->nr; i++) {
4463                        struct diff_filepair *p = q->queue[i];
4464                        if (check_pair_status(p))
4465                                diff_flush_patch(p, options);
4466                }
4467        }
4468
4469        if (output_format & DIFF_FORMAT_CALLBACK)
4470                options->format_callback(q, options, options->format_callback_data);
4471
4472        for (i = 0; i < q->nr; i++)
4473                diff_free_filepair(q->queue[i]);
4474free_queue:
4475        free(q->queue);
4476        DIFF_QUEUE_CLEAR(q);
4477        if (options->close_file)
4478                fclose(options->file);
4479
4480        /*
4481         * Report the content-level differences with HAS_CHANGES;
4482         * diff_addremove/diff_change does not set the bit when
4483         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4484         */
4485        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4486                if (options->found_changes)
4487                        DIFF_OPT_SET(options, HAS_CHANGES);
4488                else
4489                        DIFF_OPT_CLR(options, HAS_CHANGES);
4490        }
4491}
4492
4493static void diffcore_apply_filter(const char *filter)
4494{
4495        int i;
4496        struct diff_queue_struct *q = &diff_queued_diff;
4497        struct diff_queue_struct outq;
4498        DIFF_QUEUE_CLEAR(&outq);
4499
4500        if (!filter)
4501                return;
4502
4503        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4504                int found;
4505                for (i = found = 0; !found && i < q->nr; i++) {
4506                        struct diff_filepair *p = q->queue[i];
4507                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4508                             ((p->score &&
4509                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4510                              (!p->score &&
4511                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4512                            ((p->status != DIFF_STATUS_MODIFIED) &&
4513                             strchr(filter, p->status)))
4514                                found++;
4515                }
4516                if (found)
4517                        return;
4518
4519                /* otherwise we will clear the whole queue
4520                 * by copying the empty outq at the end of this
4521                 * function, but first clear the current entries
4522                 * in the queue.
4523                 */
4524                for (i = 0; i < q->nr; i++)
4525                        diff_free_filepair(q->queue[i]);
4526        }
4527        else {
4528                /* Only the matching ones */
4529                for (i = 0; i < q->nr; i++) {
4530                        struct diff_filepair *p = q->queue[i];
4531
4532                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4533                             ((p->score &&
4534                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4535                              (!p->score &&
4536                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4537                            ((p->status != DIFF_STATUS_MODIFIED) &&
4538                             strchr(filter, p->status)))
4539                                diff_q(&outq, p);
4540                        else
4541                                diff_free_filepair(p);
4542                }
4543        }
4544        free(q->queue);
4545        *q = outq;
4546}
4547
4548/* Check whether two filespecs with the same mode and size are identical */
4549static int diff_filespec_is_identical(struct diff_filespec *one,
4550                                      struct diff_filespec *two)
4551{
4552        if (S_ISGITLINK(one->mode))
4553                return 0;
4554        if (diff_populate_filespec(one, 0))
4555                return 0;
4556        if (diff_populate_filespec(two, 0))
4557                return 0;
4558        return !memcmp(one->data, two->data, one->size);
4559}
4560
4561static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4562{
4563        int i;
4564        struct diff_queue_struct *q = &diff_queued_diff;
4565        struct diff_queue_struct outq;
4566        DIFF_QUEUE_CLEAR(&outq);
4567
4568        for (i = 0; i < q->nr; i++) {
4569                struct diff_filepair *p = q->queue[i];
4570
4571                /*
4572                 * 1. Entries that come from stat info dirtiness
4573                 *    always have both sides (iow, not create/delete),
4574                 *    one side of the object name is unknown, with
4575                 *    the same mode and size.  Keep the ones that
4576                 *    do not match these criteria.  They have real
4577                 *    differences.
4578                 *
4579                 * 2. At this point, the file is known to be modified,
4580                 *    with the same mode and size, and the object
4581                 *    name of one side is unknown.  Need to inspect
4582                 *    the identical contents.
4583                 */
4584                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4585                    !DIFF_FILE_VALID(p->two) ||
4586                    (p->one->sha1_valid && p->two->sha1_valid) ||
4587                    (p->one->mode != p->two->mode) ||
4588                    diff_populate_filespec(p->one, 1) ||
4589                    diff_populate_filespec(p->two, 1) ||
4590                    (p->one->size != p->two->size) ||
4591                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4592                        diff_q(&outq, p);
4593                else {
4594                        /*
4595                         * The caller can subtract 1 from skip_stat_unmatch
4596                         * to determine how many paths were dirty only
4597                         * due to stat info mismatch.
4598                         */
4599                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4600                                diffopt->skip_stat_unmatch++;
4601                        diff_free_filepair(p);
4602                }
4603        }
4604        free(q->queue);
4605        *q = outq;
4606}
4607
4608static int diffnamecmp(const void *a_, const void *b_)
4609{
4610        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4611        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4612        const char *name_a, *name_b;
4613
4614        name_a = a->one ? a->one->path : a->two->path;
4615        name_b = b->one ? b->one->path : b->two->path;
4616        return strcmp(name_a, name_b);
4617}
4618
4619void diffcore_fix_diff_index(struct diff_options *options)
4620{
4621        struct diff_queue_struct *q = &diff_queued_diff;
4622        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4623}
4624
4625void diffcore_std(struct diff_options *options)
4626{
4627        if (options->skip_stat_unmatch)
4628                diffcore_skip_stat_unmatch(options);
4629        if (!options->found_follow) {
4630                /* See try_to_follow_renames() in tree-diff.c */
4631                if (options->break_opt != -1)
4632                        diffcore_break(options->break_opt);
4633                if (options->detect_rename)
4634                        diffcore_rename(options);
4635                if (options->break_opt != -1)
4636                        diffcore_merge_broken();
4637        }
4638        if (options->pickaxe)
4639                diffcore_pickaxe(options);
4640        if (options->orderfile)
4641                diffcore_order(options->orderfile);
4642        if (!options->found_follow)
4643                /* See try_to_follow_renames() in tree-diff.c */
4644                diff_resolve_rename_copy();
4645        diffcore_apply_filter(options->filter);
4646
4647        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4648                DIFF_OPT_SET(options, HAS_CHANGES);
4649        else
4650                DIFF_OPT_CLR(options, HAS_CHANGES);
4651
4652        options->found_follow = 0;
4653}
4654
4655int diff_result_code(struct diff_options *opt, int status)
4656{
4657        int result = 0;
4658
4659        diff_warn_rename_limit("diff.renamelimit",
4660                               opt->needed_rename_limit,
4661                               opt->degraded_cc_to_c);
4662        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4663            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4664                return status;
4665        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4666            DIFF_OPT_TST(opt, HAS_CHANGES))
4667                result |= 01;
4668        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4669            DIFF_OPT_TST(opt, CHECK_FAILED))
4670                result |= 02;
4671        return result;
4672}
4673
4674int diff_can_quit_early(struct diff_options *opt)
4675{
4676        return (DIFF_OPT_TST(opt, QUICK) &&
4677                !opt->filter &&
4678                DIFF_OPT_TST(opt, HAS_CHANGES));
4679}
4680
4681/*
4682 * Shall changes to this submodule be ignored?
4683 *
4684 * Submodule changes can be configured to be ignored separately for each path,
4685 * but that configuration can be overridden from the command line.
4686 */
4687static int is_submodule_ignored(const char *path, struct diff_options *options)
4688{
4689        int ignored = 0;
4690        unsigned orig_flags = options->flags;
4691        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4692                set_diffopt_flags_from_submodule_config(options, path);
4693        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4694                ignored = 1;
4695        options->flags = orig_flags;
4696        return ignored;
4697}
4698
4699void diff_addremove(struct diff_options *options,
4700                    int addremove, unsigned mode,
4701                    const unsigned char *sha1,
4702                    const char *concatpath, unsigned dirty_submodule)
4703{
4704        struct diff_filespec *one, *two;
4705
4706        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4707                return;
4708
4709        /* This may look odd, but it is a preparation for
4710         * feeding "there are unchanged files which should
4711         * not produce diffs, but when you are doing copy
4712         * detection you would need them, so here they are"
4713         * entries to the diff-core.  They will be prefixed
4714         * with something like '=' or '*' (I haven't decided
4715         * which but should not make any difference).
4716         * Feeding the same new and old to diff_change()
4717         * also has the same effect.
4718         * Before the final output happens, they are pruned after
4719         * merged into rename/copy pairs as appropriate.
4720         */
4721        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4722                addremove = (addremove == '+' ? '-' :
4723                             addremove == '-' ? '+' : addremove);
4724
4725        if (options->prefix &&
4726            strncmp(concatpath, options->prefix, options->prefix_length))
4727                return;
4728
4729        one = alloc_filespec(concatpath);
4730        two = alloc_filespec(concatpath);
4731
4732        if (addremove != '+')
4733                fill_filespec(one, sha1, mode);
4734        if (addremove != '-') {
4735                fill_filespec(two, sha1, mode);
4736                two->dirty_submodule = dirty_submodule;
4737        }
4738
4739        diff_queue(&diff_queued_diff, one, two);
4740        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4741                DIFF_OPT_SET(options, HAS_CHANGES);
4742}
4743
4744void diff_change(struct diff_options *options,
4745                 unsigned old_mode, unsigned new_mode,
4746                 const unsigned char *old_sha1,
4747                 const unsigned char *new_sha1,
4748                 const char *concatpath,
4749                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4750{
4751        struct diff_filespec *one, *two;
4752
4753        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4754            is_submodule_ignored(concatpath, options))
4755                return;
4756
4757        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4758                unsigned tmp;
4759                const unsigned char *tmp_c;
4760                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4761                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4762                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4763                        new_dirty_submodule = tmp;
4764        }
4765
4766        if (options->prefix &&
4767            strncmp(concatpath, options->prefix, options->prefix_length))
4768                return;
4769
4770        one = alloc_filespec(concatpath);
4771        two = alloc_filespec(concatpath);
4772        fill_filespec(one, old_sha1, old_mode);
4773        fill_filespec(two, new_sha1, new_mode);
4774        one->dirty_submodule = old_dirty_submodule;
4775        two->dirty_submodule = new_dirty_submodule;
4776
4777        diff_queue(&diff_queued_diff, one, two);
4778        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4779                DIFF_OPT_SET(options, HAS_CHANGES);
4780}
4781
4782struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4783{
4784        struct diff_filepair *pair;
4785        struct diff_filespec *one, *two;
4786
4787        if (options->prefix &&
4788            strncmp(path, options->prefix, options->prefix_length))
4789                return NULL;
4790
4791        one = alloc_filespec(path);
4792        two = alloc_filespec(path);
4793        pair = diff_queue(&diff_queued_diff, one, two);
4794        pair->is_unmerged = 1;
4795        return pair;
4796}
4797
4798static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4799                size_t *outsize)
4800{
4801        struct diff_tempfile *temp;
4802        const char *argv[3];
4803        const char **arg = argv;
4804        struct child_process child;
4805        struct strbuf buf = STRBUF_INIT;
4806        int err = 0;
4807
4808        temp = prepare_temp_file(spec->path, spec);
4809        *arg++ = pgm;
4810        *arg++ = temp->name;
4811        *arg = NULL;
4812
4813        memset(&child, 0, sizeof(child));
4814        child.use_shell = 1;
4815        child.argv = argv;
4816        child.out = -1;
4817        if (start_command(&child)) {
4818                remove_tempfile();
4819                return NULL;
4820        }
4821
4822        if (strbuf_read(&buf, child.out, 0) < 0)
4823                err = error("error reading from textconv command '%s'", pgm);
4824        close(child.out);
4825
4826        if (finish_command(&child) || err) {
4827                strbuf_release(&buf);
4828                remove_tempfile();
4829                return NULL;
4830        }
4831        remove_tempfile();
4832
4833        return strbuf_detach(&buf, outsize);
4834}
4835
4836size_t fill_textconv(struct userdiff_driver *driver,
4837                     struct diff_filespec *df,
4838                     char **outbuf)
4839{
4840        size_t size;
4841
4842        if (!driver || !driver->textconv) {
4843                if (!DIFF_FILE_VALID(df)) {
4844                        *outbuf = "";
4845                        return 0;
4846                }
4847                if (diff_populate_filespec(df, 0))
4848                        die("unable to read files to diff");
4849                *outbuf = df->data;
4850                return df->size;
4851        }
4852
4853        if (driver->textconv_cache && df->sha1_valid) {
4854                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4855                                          &size);
4856                if (*outbuf)
4857                        return size;
4858        }
4859
4860        *outbuf = run_textconv(driver->textconv, df, &size);
4861        if (!*outbuf)
4862                die("unable to read files to diff");
4863
4864        if (driver->textconv_cache && df->sha1_valid) {
4865                /* ignore errors, as we might be in a readonly repository */
4866                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4867                                size);
4868                /*
4869                 * we could save up changes and flush them all at the end,
4870                 * but we would need an extra call after all diffing is done.
4871                 * Since generating a cache entry is the slow path anyway,
4872                 * this extra overhead probably isn't a big deal.
4873                 */
4874                notes_cache_write(driver->textconv_cache);
4875        }
4876
4877        return size;
4878}