diff-lib.con commit Merge branch 'master' into next (56c155a)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include <sys/types.h>
   5#include <sys/wait.h>
   6#include <signal.h>
   7#include "cache.h"
   8#include "quote.h"
   9#include "diff.h"
  10#include "diffcore.h"
  11#include "xdiff-interface.h"
  12
  13static int use_size_cache;
  14
  15int diff_rename_limit_default = -1;
  16
  17int git_diff_config(const char *var, const char *value)
  18{
  19        if (!strcmp(var, "diff.renamelimit")) {
  20                diff_rename_limit_default = git_config_int(var, value);
  21                return 0;
  22        }
  23
  24        return git_default_config(var, value);
  25}
  26
  27static char *quote_one(const char *str)
  28{
  29        int needlen;
  30        char *xp;
  31
  32        if (!str)
  33                return NULL;
  34        needlen = quote_c_style(str, NULL, NULL, 0);
  35        if (!needlen)
  36                return strdup(str);
  37        xp = xmalloc(needlen + 1);
  38        quote_c_style(str, xp, NULL, 0);
  39        return xp;
  40}
  41
  42static char *quote_two(const char *one, const char *two)
  43{
  44        int need_one = quote_c_style(one, NULL, NULL, 1);
  45        int need_two = quote_c_style(two, NULL, NULL, 1);
  46        char *xp;
  47
  48        if (need_one + need_two) {
  49                if (!need_one) need_one = strlen(one);
  50                if (!need_two) need_one = strlen(two);
  51
  52                xp = xmalloc(need_one + need_two + 3);
  53                xp[0] = '"';
  54                quote_c_style(one, xp + 1, NULL, 1);
  55                quote_c_style(two, xp + need_one + 1, NULL, 1);
  56                strcpy(xp + need_one + need_two + 1, "\"");
  57                return xp;
  58        }
  59        need_one = strlen(one);
  60        need_two = strlen(two);
  61        xp = xmalloc(need_one + need_two + 1);
  62        strcpy(xp, one);
  63        strcpy(xp + need_one, two);
  64        return xp;
  65}
  66
  67static const char *external_diff(void)
  68{
  69        static const char *external_diff_cmd = NULL;
  70        static int done_preparing = 0;
  71
  72        if (done_preparing)
  73                return external_diff_cmd;
  74        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
  75        done_preparing = 1;
  76        return external_diff_cmd;
  77}
  78
  79#define TEMPFILE_PATH_LEN               50
  80
  81static struct diff_tempfile {
  82        const char *name; /* filename external diff should read from */
  83        char hex[41];
  84        char mode[10];
  85        char tmp_path[TEMPFILE_PATH_LEN];
  86} diff_temp[2];
  87
  88static int count_lines(const char *data, int size)
  89{
  90        int count, ch, completely_empty = 1, nl_just_seen = 0;
  91        count = 0;
  92        while (0 < size--) {
  93                ch = *data++;
  94                if (ch == '\n') {
  95                        count++;
  96                        nl_just_seen = 1;
  97                        completely_empty = 0;
  98                }
  99                else {
 100                        nl_just_seen = 0;
 101                        completely_empty = 0;
 102                }
 103        }
 104        if (completely_empty)
 105                return 0;
 106        if (!nl_just_seen)
 107                count++; /* no trailing newline */
 108        return count;
 109}
 110
 111static void print_line_count(int count)
 112{
 113        switch (count) {
 114        case 0:
 115                printf("0,0");
 116                break;
 117        case 1:
 118                printf("1");
 119                break;
 120        default:
 121                printf("1,%d", count);
 122                break;
 123        }
 124}
 125
 126static void copy_file(int prefix, const char *data, int size)
 127{
 128        int ch, nl_just_seen = 1;
 129        while (0 < size--) {
 130                ch = *data++;
 131                if (nl_just_seen)
 132                        putchar(prefix);
 133                putchar(ch);
 134                if (ch == '\n')
 135                        nl_just_seen = 1;
 136                else
 137                        nl_just_seen = 0;
 138        }
 139        if (!nl_just_seen)
 140                printf("\n\\ No newline at end of file\n");
 141}
 142
 143static void emit_rewrite_diff(const char *name_a,
 144                              const char *name_b,
 145                              struct diff_filespec *one,
 146                              struct diff_filespec *two)
 147{
 148        int lc_a, lc_b;
 149        diff_populate_filespec(one, 0);
 150        diff_populate_filespec(two, 0);
 151        lc_a = count_lines(one->data, one->size);
 152        lc_b = count_lines(two->data, two->size);
 153        printf("--- %s\n+++ %s\n@@ -", name_a, name_b);
 154        print_line_count(lc_a);
 155        printf(" +");
 156        print_line_count(lc_b);
 157        printf(" @@\n");
 158        if (lc_a)
 159                copy_file('-', one->data, one->size);
 160        if (lc_b)
 161                copy_file('+', two->data, two->size);
 162}
 163
 164static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 165{
 166        if (!DIFF_FILE_VALID(one)) {
 167                mf->ptr = ""; /* does not matter */
 168                mf->size = 0;
 169                return 0;
 170        }
 171        else if (diff_populate_filespec(one, 0))
 172                return -1;
 173        mf->ptr = one->data;
 174        mf->size = one->size;
 175        return 0;
 176}
 177
 178struct emit_callback {
 179        const char **label_path;
 180};
 181
 182static int fn_out(void *priv, mmbuffer_t *mb, int nbuf)
 183{
 184        int i;
 185        struct emit_callback *ecbdata = priv;
 186
 187        if (ecbdata->label_path[0]) {
 188                printf("--- %s\n", ecbdata->label_path[0]);
 189                printf("+++ %s\n", ecbdata->label_path[1]);
 190                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 191        }
 192        for (i = 0; i < nbuf; i++)
 193                if (!fwrite(mb[i].ptr, mb[i].size, 1, stdout))
 194                        return -1;
 195        return 0;
 196}
 197
 198static char *pprint_rename(const char *a, const char *b)
 199{
 200        const char *old = a;
 201        const char *new = b;
 202        char *name = NULL;
 203        int pfx_length, sfx_length;
 204        int len_a = strlen(a);
 205        int len_b = strlen(b);
 206
 207        /* Find common prefix */
 208        pfx_length = 0;
 209        while (*old && *new && *old == *new) {
 210                if (*old == '/')
 211                        pfx_length = old - a + 1;
 212                old++;
 213                new++;
 214        }
 215
 216        /* Find common suffix */
 217        old = a + len_a;
 218        new = b + len_b;
 219        sfx_length = 0;
 220        while (a <= old && b <= new && *old == *new) {
 221                if (*old == '/')
 222                        sfx_length = len_a - (old - a);
 223                old--;
 224                new--;
 225        }
 226
 227        /*
 228         * pfx{mid-a => mid-b}sfx
 229         * {pfx-a => pfx-b}sfx
 230         * pfx{sfx-a => sfx-b}
 231         * name-a => name-b
 232         */
 233        if (pfx_length + sfx_length) {
 234                name = xmalloc(len_a + len_b - pfx_length - sfx_length + 7);
 235                sprintf(name, "%.*s{%.*s => %.*s}%s",
 236                        pfx_length, a,
 237                        len_a - pfx_length - sfx_length, a + pfx_length,
 238                        len_b - pfx_length - sfx_length, b + pfx_length,
 239                        a + len_a - sfx_length);
 240        }
 241        else {
 242                name = xmalloc(len_a + len_b + 5);
 243                sprintf(name, "%s => %s", a, b);
 244        }
 245        return name;
 246}
 247
 248struct diffstat_t {
 249        struct xdiff_emit_state xm;
 250
 251        int nr;
 252        int alloc;
 253        struct diffstat_file {
 254                char *name;
 255                unsigned is_unmerged:1;
 256                unsigned is_binary:1;
 257                unsigned is_renamed:1;
 258                unsigned int added, deleted;
 259        } **files;
 260};
 261
 262static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
 263                                          const char *name_a,
 264                                          const char *name_b)
 265{
 266        struct diffstat_file *x;
 267        x = xcalloc(sizeof (*x), 1);
 268        if (diffstat->nr == diffstat->alloc) {
 269                diffstat->alloc = alloc_nr(diffstat->alloc);
 270                diffstat->files = xrealloc(diffstat->files,
 271                                diffstat->alloc * sizeof(x));
 272        }
 273        diffstat->files[diffstat->nr++] = x;
 274        if (name_b) {
 275                x->name = pprint_rename(name_a, name_b);
 276                x->is_renamed = 1;
 277        }
 278        else
 279                x->name = strdup(name_a);
 280        return x;
 281}
 282
 283static void diffstat_consume(void *priv, char *line, unsigned long len)
 284{
 285        struct diffstat_t *diffstat = priv;
 286        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
 287
 288        if (line[0] == '+')
 289                x->added++;
 290        else if (line[0] == '-')
 291                x->deleted++;
 292}
 293
 294static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
 295static const char minuses[]= "----------------------------------------------------------------------";
 296
 297static void show_stats(struct diffstat_t* data)
 298{
 299        char *prefix = "";
 300        int i, len, add, del, total, adds = 0, dels = 0;
 301        int max, max_change = 0, max_len = 0;
 302        int total_files = data->nr;
 303
 304        if (data->nr == 0)
 305                return;
 306
 307        for (i = 0; i < data->nr; i++) {
 308                struct diffstat_file *file = data->files[i];
 309
 310                len = strlen(file->name);
 311                if (max_len < len)
 312                        max_len = len;
 313
 314                if (file->is_binary || file->is_unmerged)
 315                        continue;
 316                if (max_change < file->added + file->deleted)
 317                        max_change = file->added + file->deleted;
 318        }
 319
 320        for (i = 0; i < data->nr; i++) {
 321                char *name = data->files[i]->name;
 322                int added = data->files[i]->added;
 323                int deleted = data->files[i]->deleted;
 324
 325                if (0 < (len = quote_c_style(name, NULL, NULL, 0))) {
 326                        char *qname = xmalloc(len + 1);
 327                        quote_c_style(name, qname, NULL, 0);
 328                        free(name);
 329                        data->files[i]->name = name = qname;
 330                }
 331
 332                /*
 333                 * "scale" the filename
 334                 */
 335                len = strlen(name);
 336                max = max_len;
 337                if (max > 50)
 338                        max = 50;
 339                if (len > max) {
 340                        char *slash;
 341                        prefix = "...";
 342                        max -= 3;
 343                        name += len - max;
 344                        slash = strchr(name, '/');
 345                        if (slash)
 346                                name = slash;
 347                }
 348                len = max;
 349
 350                /*
 351                 * scale the add/delete
 352                 */
 353                max = max_change;
 354                if (max + len > 70)
 355                        max = 70 - len;
 356
 357                if (data->files[i]->is_binary) {
 358                        printf(" %s%-*s |  Bin\n", prefix, len, name);
 359                        goto free_diffstat_file;
 360                }
 361                else if (data->files[i]->is_unmerged) {
 362                        printf(" %s%-*s |  Unmerged\n", prefix, len, name);
 363                        goto free_diffstat_file;
 364                }
 365                else if (!data->files[i]->is_renamed &&
 366                         (added + deleted == 0)) {
 367                        total_files--;
 368                        goto free_diffstat_file;
 369                }
 370
 371                add = added;
 372                del = deleted;
 373                total = add + del;
 374                adds += add;
 375                dels += del;
 376
 377                if (max_change > 0) {
 378                        total = (total * max + max_change / 2) / max_change;
 379                        add = (add * max + max_change / 2) / max_change;
 380                        del = total - add;
 381                }
 382                printf(" %s%-*s |%5d %.*s%.*s\n", prefix,
 383                                len, name, added + deleted,
 384                                add, pluses, del, minuses);
 385        free_diffstat_file:
 386                free(data->files[i]->name);
 387                free(data->files[i]);
 388        }
 389        free(data->files);
 390        printf(" %d files changed, %d insertions(+), %d deletions(-)\n",
 391                        total_files, adds, dels);
 392}
 393
 394#define FIRST_FEW_BYTES 8000
 395static int mmfile_is_binary(mmfile_t *mf)
 396{
 397        long sz = mf->size;
 398        if (FIRST_FEW_BYTES < sz)
 399                sz = FIRST_FEW_BYTES;
 400        if (memchr(mf->ptr, 0, sz))
 401                return 1;
 402        return 0;
 403}
 404
 405static void builtin_diff(const char *name_a,
 406                         const char *name_b,
 407                         struct diff_filespec *one,
 408                         struct diff_filespec *two,
 409                         const char *xfrm_msg,
 410                         int complete_rewrite)
 411{
 412        mmfile_t mf1, mf2;
 413        const char *lbl[2];
 414        char *a_one, *b_two;
 415
 416        a_one = quote_two("a/", name_a);
 417        b_two = quote_two("b/", name_b);
 418        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
 419        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
 420        printf("diff --git %s %s\n", a_one, b_two);
 421        if (lbl[0][0] == '/') {
 422                /* /dev/null */
 423                printf("new file mode %06o\n", two->mode);
 424                if (xfrm_msg && xfrm_msg[0])
 425                        puts(xfrm_msg);
 426        }
 427        else if (lbl[1][0] == '/') {
 428                printf("deleted file mode %06o\n", one->mode);
 429                if (xfrm_msg && xfrm_msg[0])
 430                        puts(xfrm_msg);
 431        }
 432        else {
 433                if (one->mode != two->mode) {
 434                        printf("old mode %06o\n", one->mode);
 435                        printf("new mode %06o\n", two->mode);
 436                }
 437                if (xfrm_msg && xfrm_msg[0])
 438                        puts(xfrm_msg);
 439                /*
 440                 * we do not run diff between different kind
 441                 * of objects.
 442                 */
 443                if ((one->mode ^ two->mode) & S_IFMT)
 444                        goto free_ab_and_return;
 445                if (complete_rewrite) {
 446                        emit_rewrite_diff(name_a, name_b, one, two);
 447                        goto free_ab_and_return;
 448                }
 449        }
 450
 451        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
 452                die("unable to read files to diff");
 453
 454        if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))
 455                printf("Binary files %s and %s differ\n", lbl[0], lbl[1]);
 456        else {
 457                /* Crazy xdl interfaces.. */
 458                const char *diffopts = getenv("GIT_DIFF_OPTS");
 459                xpparam_t xpp;
 460                xdemitconf_t xecfg;
 461                xdemitcb_t ecb;
 462                struct emit_callback ecbdata;
 463
 464                ecbdata.label_path = lbl;
 465                xpp.flags = XDF_NEED_MINIMAL;
 466                xecfg.ctxlen = 3;
 467                xecfg.flags = XDL_EMIT_FUNCNAMES;
 468                if (!diffopts)
 469                        ;
 470                else if (!strncmp(diffopts, "--unified=", 10))
 471                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
 472                else if (!strncmp(diffopts, "-u", 2))
 473                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
 474                ecb.outf = fn_out;
 475                ecb.priv = &ecbdata;
 476                xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
 477        }
 478
 479 free_ab_and_return:
 480        free(a_one);
 481        free(b_two);
 482        return;
 483}
 484
 485static void builtin_diffstat(const char *name_a, const char *name_b,
 486                             struct diff_filespec *one,
 487                             struct diff_filespec *two,
 488                             struct diffstat_t *diffstat)
 489{
 490        mmfile_t mf1, mf2;
 491        struct diffstat_file *data;
 492
 493        data = diffstat_add(diffstat, name_a, name_b);
 494
 495        if (!one || !two) {
 496                data->is_unmerged = 1;
 497                return;
 498        }
 499
 500        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
 501                die("unable to read files to diff");
 502
 503        if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))
 504                data->is_binary = 1;
 505        else {
 506                /* Crazy xdl interfaces.. */
 507                xpparam_t xpp;
 508                xdemitconf_t xecfg;
 509                xdemitcb_t ecb;
 510
 511                xpp.flags = XDF_NEED_MINIMAL;
 512                xecfg.ctxlen = 0;
 513                xecfg.flags = 0;
 514                ecb.outf = xdiff_outf;
 515                ecb.priv = diffstat;
 516                xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
 517        }
 518}
 519
 520struct diff_filespec *alloc_filespec(const char *path)
 521{
 522        int namelen = strlen(path);
 523        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
 524
 525        memset(spec, 0, sizeof(*spec));
 526        spec->path = (char *)(spec + 1);
 527        memcpy(spec->path, path, namelen+1);
 528        return spec;
 529}
 530
 531void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
 532                   unsigned short mode)
 533{
 534        if (mode) {
 535                spec->mode = canon_mode(mode);
 536                memcpy(spec->sha1, sha1, 20);
 537                spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
 538        }
 539}
 540
 541/*
 542 * Given a name and sha1 pair, if the dircache tells us the file in
 543 * the work tree has that object contents, return true, so that
 544 * prepare_temp_file() does not have to inflate and extract.
 545 */
 546static int work_tree_matches(const char *name, const unsigned char *sha1)
 547{
 548        struct cache_entry *ce;
 549        struct stat st;
 550        int pos, len;
 551
 552        /* We do not read the cache ourselves here, because the
 553         * benchmark with my previous version that always reads cache
 554         * shows that it makes things worse for diff-tree comparing
 555         * two linux-2.6 kernel trees in an already checked out work
 556         * tree.  This is because most diff-tree comparisons deal with
 557         * only a small number of files, while reading the cache is
 558         * expensive for a large project, and its cost outweighs the
 559         * savings we get by not inflating the object to a temporary
 560         * file.  Practically, this code only helps when we are used
 561         * by diff-cache --cached, which does read the cache before
 562         * calling us.
 563         */
 564        if (!active_cache)
 565                return 0;
 566
 567        len = strlen(name);
 568        pos = cache_name_pos(name, len);
 569        if (pos < 0)
 570                return 0;
 571        ce = active_cache[pos];
 572        if ((lstat(name, &st) < 0) ||
 573            !S_ISREG(st.st_mode) || /* careful! */
 574            ce_match_stat(ce, &st, 0) ||
 575            memcmp(sha1, ce->sha1, 20))
 576                return 0;
 577        /* we return 1 only when we can stat, it is a regular file,
 578         * stat information matches, and sha1 recorded in the cache
 579         * matches.  I.e. we know the file in the work tree really is
 580         * the same as the <name, sha1> pair.
 581         */
 582        return 1;
 583}
 584
 585static struct sha1_size_cache {
 586        unsigned char sha1[20];
 587        unsigned long size;
 588} **sha1_size_cache;
 589static int sha1_size_cache_nr, sha1_size_cache_alloc;
 590
 591static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
 592                                                 int find_only,
 593                                                 unsigned long size)
 594{
 595        int first, last;
 596        struct sha1_size_cache *e;
 597
 598        first = 0;
 599        last = sha1_size_cache_nr;
 600        while (last > first) {
 601                int cmp, next = (last + first) >> 1;
 602                e = sha1_size_cache[next];
 603                cmp = memcmp(e->sha1, sha1, 20);
 604                if (!cmp)
 605                        return e;
 606                if (cmp < 0) {
 607                        last = next;
 608                        continue;
 609                }
 610                first = next+1;
 611        }
 612        /* not found */
 613        if (find_only)
 614                return NULL;
 615        /* insert to make it at "first" */
 616        if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
 617                sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
 618                sha1_size_cache = xrealloc(sha1_size_cache,
 619                                           sha1_size_cache_alloc *
 620                                           sizeof(*sha1_size_cache));
 621        }
 622        sha1_size_cache_nr++;
 623        if (first < sha1_size_cache_nr)
 624                memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
 625                        (sha1_size_cache_nr - first - 1) *
 626                        sizeof(*sha1_size_cache));
 627        e = xmalloc(sizeof(struct sha1_size_cache));
 628        sha1_size_cache[first] = e;
 629        memcpy(e->sha1, sha1, 20);
 630        e->size = size;
 631        return e;
 632}
 633
 634/*
 635 * While doing rename detection and pickaxe operation, we may need to
 636 * grab the data for the blob (or file) for our own in-core comparison.
 637 * diff_filespec has data and size fields for this purpose.
 638 */
 639int diff_populate_filespec(struct diff_filespec *s, int size_only)
 640{
 641        int err = 0;
 642        if (!DIFF_FILE_VALID(s))
 643                die("internal error: asking to populate invalid file.");
 644        if (S_ISDIR(s->mode))
 645                return -1;
 646
 647        if (!use_size_cache)
 648                size_only = 0;
 649
 650        if (s->data)
 651                return err;
 652        if (!s->sha1_valid ||
 653            work_tree_matches(s->path, s->sha1)) {
 654                struct stat st;
 655                int fd;
 656                if (lstat(s->path, &st) < 0) {
 657                        if (errno == ENOENT) {
 658                        err_empty:
 659                                err = -1;
 660                        empty:
 661                                s->data = "";
 662                                s->size = 0;
 663                                return err;
 664                        }
 665                }
 666                s->size = st.st_size;
 667                if (!s->size)
 668                        goto empty;
 669                if (size_only)
 670                        return 0;
 671                if (S_ISLNK(st.st_mode)) {
 672                        int ret;
 673                        s->data = xmalloc(s->size);
 674                        s->should_free = 1;
 675                        ret = readlink(s->path, s->data, s->size);
 676                        if (ret < 0) {
 677                                free(s->data);
 678                                goto err_empty;
 679                        }
 680                        return 0;
 681                }
 682                fd = open(s->path, O_RDONLY);
 683                if (fd < 0)
 684                        goto err_empty;
 685                s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
 686                close(fd);
 687                if (s->data == MAP_FAILED)
 688                        goto err_empty;
 689                s->should_munmap = 1;
 690        }
 691        else {
 692                char type[20];
 693                struct sha1_size_cache *e;
 694
 695                if (size_only) {
 696                        e = locate_size_cache(s->sha1, 1, 0);
 697                        if (e) {
 698                                s->size = e->size;
 699                                return 0;
 700                        }
 701                        if (!sha1_object_info(s->sha1, type, &s->size))
 702                                locate_size_cache(s->sha1, 0, s->size);
 703                }
 704                else {
 705                        s->data = read_sha1_file(s->sha1, type, &s->size);
 706                        s->should_free = 1;
 707                }
 708        }
 709        return 0;
 710}
 711
 712void diff_free_filespec_data(struct diff_filespec *s)
 713{
 714        if (s->should_free)
 715                free(s->data);
 716        else if (s->should_munmap)
 717                munmap(s->data, s->size);
 718        s->should_free = s->should_munmap = 0;
 719        s->data = NULL;
 720        free(s->cnt_data);
 721        s->cnt_data = NULL;
 722}
 723
 724static void prep_temp_blob(struct diff_tempfile *temp,
 725                           void *blob,
 726                           unsigned long size,
 727                           const unsigned char *sha1,
 728                           int mode)
 729{
 730        int fd;
 731
 732        fd = git_mkstemp(temp->tmp_path, TEMPFILE_PATH_LEN, ".diff_XXXXXX");
 733        if (fd < 0)
 734                die("unable to create temp-file");
 735        if (write(fd, blob, size) != size)
 736                die("unable to write temp-file");
 737        close(fd);
 738        temp->name = temp->tmp_path;
 739        strcpy(temp->hex, sha1_to_hex(sha1));
 740        temp->hex[40] = 0;
 741        sprintf(temp->mode, "%06o", mode);
 742}
 743
 744static void prepare_temp_file(const char *name,
 745                              struct diff_tempfile *temp,
 746                              struct diff_filespec *one)
 747{
 748        if (!DIFF_FILE_VALID(one)) {
 749        not_a_valid_file:
 750                /* A '-' entry produces this for file-2, and
 751                 * a '+' entry produces this for file-1.
 752                 */
 753                temp->name = "/dev/null";
 754                strcpy(temp->hex, ".");
 755                strcpy(temp->mode, ".");
 756                return;
 757        }
 758
 759        if (!one->sha1_valid ||
 760            work_tree_matches(name, one->sha1)) {
 761                struct stat st;
 762                if (lstat(name, &st) < 0) {
 763                        if (errno == ENOENT)
 764                                goto not_a_valid_file;
 765                        die("stat(%s): %s", name, strerror(errno));
 766                }
 767                if (S_ISLNK(st.st_mode)) {
 768                        int ret;
 769                        char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
 770                        if (sizeof(buf) <= st.st_size)
 771                                die("symlink too long: %s", name);
 772                        ret = readlink(name, buf, st.st_size);
 773                        if (ret < 0)
 774                                die("readlink(%s)", name);
 775                        prep_temp_blob(temp, buf, st.st_size,
 776                                       (one->sha1_valid ?
 777                                        one->sha1 : null_sha1),
 778                                       (one->sha1_valid ?
 779                                        one->mode : S_IFLNK));
 780                }
 781                else {
 782                        /* we can borrow from the file in the work tree */
 783                        temp->name = name;
 784                        if (!one->sha1_valid)
 785                                strcpy(temp->hex, sha1_to_hex(null_sha1));
 786                        else
 787                                strcpy(temp->hex, sha1_to_hex(one->sha1));
 788                        /* Even though we may sometimes borrow the
 789                         * contents from the work tree, we always want
 790                         * one->mode.  mode is trustworthy even when
 791                         * !(one->sha1_valid), as long as
 792                         * DIFF_FILE_VALID(one).
 793                         */
 794                        sprintf(temp->mode, "%06o", one->mode);
 795                }
 796                return;
 797        }
 798        else {
 799                if (diff_populate_filespec(one, 0))
 800                        die("cannot read data blob for %s", one->path);
 801                prep_temp_blob(temp, one->data, one->size,
 802                               one->sha1, one->mode);
 803        }
 804}
 805
 806static void remove_tempfile(void)
 807{
 808        int i;
 809
 810        for (i = 0; i < 2; i++)
 811                if (diff_temp[i].name == diff_temp[i].tmp_path) {
 812                        unlink(diff_temp[i].name);
 813                        diff_temp[i].name = NULL;
 814                }
 815}
 816
 817static void remove_tempfile_on_signal(int signo)
 818{
 819        remove_tempfile();
 820        signal(SIGINT, SIG_DFL);
 821        raise(signo);
 822}
 823
 824static int spawn_prog(const char *pgm, const char **arg)
 825{
 826        pid_t pid;
 827        int status;
 828
 829        fflush(NULL);
 830        pid = fork();
 831        if (pid < 0)
 832                die("unable to fork");
 833        if (!pid) {
 834                execvp(pgm, (char *const*) arg);
 835                exit(255);
 836        }
 837
 838        while (waitpid(pid, &status, 0) < 0) {
 839                if (errno == EINTR)
 840                        continue;
 841                return -1;
 842        }
 843
 844        /* Earlier we did not check the exit status because
 845         * diff exits non-zero if files are different, and
 846         * we are not interested in knowing that.  It was a
 847         * mistake which made it harder to quit a diff-*
 848         * session that uses the git-apply-patch-script as
 849         * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
 850         * should also exit non-zero only when it wants to
 851         * abort the entire diff-* session.
 852         */
 853        if (WIFEXITED(status) && !WEXITSTATUS(status))
 854                return 0;
 855        return -1;
 856}
 857
 858/* An external diff command takes:
 859 *
 860 * diff-cmd name infile1 infile1-sha1 infile1-mode \
 861 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
 862 *
 863 */
 864static void run_external_diff(const char *pgm,
 865                              const char *name,
 866                              const char *other,
 867                              struct diff_filespec *one,
 868                              struct diff_filespec *two,
 869                              const char *xfrm_msg,
 870                              int complete_rewrite)
 871{
 872        const char *spawn_arg[10];
 873        struct diff_tempfile *temp = diff_temp;
 874        int retval;
 875        static int atexit_asked = 0;
 876        const char *othername;
 877        const char **arg = &spawn_arg[0];
 878
 879        othername = (other? other : name);
 880        if (one && two) {
 881                prepare_temp_file(name, &temp[0], one);
 882                prepare_temp_file(othername, &temp[1], two);
 883                if (! atexit_asked &&
 884                    (temp[0].name == temp[0].tmp_path ||
 885                     temp[1].name == temp[1].tmp_path)) {
 886                        atexit_asked = 1;
 887                        atexit(remove_tempfile);
 888                }
 889                signal(SIGINT, remove_tempfile_on_signal);
 890        }
 891
 892        if (one && two) {
 893                *arg++ = pgm;
 894                *arg++ = name;
 895                *arg++ = temp[0].name;
 896                *arg++ = temp[0].hex;
 897                *arg++ = temp[0].mode;
 898                *arg++ = temp[1].name;
 899                *arg++ = temp[1].hex;
 900                *arg++ = temp[1].mode;
 901                if (other) {
 902                        *arg++ = other;
 903                        *arg++ = xfrm_msg;
 904                }
 905        } else {
 906                *arg++ = pgm;
 907                *arg++ = name;
 908        }
 909        *arg = NULL;
 910        retval = spawn_prog(pgm, spawn_arg);
 911        remove_tempfile();
 912        if (retval) {
 913                fprintf(stderr, "external diff died, stopping at %s.\n", name);
 914                exit(1);
 915        }
 916}
 917
 918static void run_diff_cmd(const char *pgm,
 919                         const char *name,
 920                         const char *other,
 921                         struct diff_filespec *one,
 922                         struct diff_filespec *two,
 923                         const char *xfrm_msg,
 924                         int complete_rewrite)
 925{
 926        if (pgm) {
 927                run_external_diff(pgm, name, other, one, two, xfrm_msg,
 928                                  complete_rewrite);
 929                return;
 930        }
 931        if (one && two)
 932                builtin_diff(name, other ? other : name,
 933                             one, two, xfrm_msg, complete_rewrite);
 934        else
 935                printf("* Unmerged path %s\n", name);
 936}
 937
 938static void diff_fill_sha1_info(struct diff_filespec *one)
 939{
 940        if (DIFF_FILE_VALID(one)) {
 941                if (!one->sha1_valid) {
 942                        struct stat st;
 943                        if (lstat(one->path, &st) < 0)
 944                                die("stat %s", one->path);
 945                        if (index_path(one->sha1, one->path, &st, 0))
 946                                die("cannot hash %s\n", one->path);
 947                }
 948        }
 949        else
 950                memset(one->sha1, 0, 20);
 951}
 952
 953static void run_diff(struct diff_filepair *p, struct diff_options *o)
 954{
 955        const char *pgm = external_diff();
 956        char msg[PATH_MAX*2+300], *xfrm_msg;
 957        struct diff_filespec *one;
 958        struct diff_filespec *two;
 959        const char *name;
 960        const char *other;
 961        char *name_munged, *other_munged;
 962        int complete_rewrite = 0;
 963        int len;
 964
 965        if (DIFF_PAIR_UNMERGED(p)) {
 966                /* unmerged */
 967                run_diff_cmd(pgm, p->one->path, NULL, NULL, NULL, NULL, 0);
 968                return;
 969        }
 970
 971        name = p->one->path;
 972        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
 973        name_munged = quote_one(name);
 974        other_munged = quote_one(other);
 975        one = p->one; two = p->two;
 976
 977        diff_fill_sha1_info(one);
 978        diff_fill_sha1_info(two);
 979
 980        len = 0;
 981        switch (p->status) {
 982        case DIFF_STATUS_COPIED:
 983                len += snprintf(msg + len, sizeof(msg) - len,
 984                                "similarity index %d%%\n"
 985                                "copy from %s\n"
 986                                "copy to %s\n",
 987                                (int)(0.5 + p->score * 100.0/MAX_SCORE),
 988                                name_munged, other_munged);
 989                break;
 990        case DIFF_STATUS_RENAMED:
 991                len += snprintf(msg + len, sizeof(msg) - len,
 992                                "similarity index %d%%\n"
 993                                "rename from %s\n"
 994                                "rename to %s\n",
 995                                (int)(0.5 + p->score * 100.0/MAX_SCORE),
 996                                name_munged, other_munged);
 997                break;
 998        case DIFF_STATUS_MODIFIED:
 999                if (p->score) {
1000                        len += snprintf(msg + len, sizeof(msg) - len,
1001                                        "dissimilarity index %d%%\n",
1002                                        (int)(0.5 + p->score *
1003                                              100.0/MAX_SCORE));
1004                        complete_rewrite = 1;
1005                        break;
1006                }
1007                /* fallthru */
1008        default:
1009                /* nothing */
1010                ;
1011        }
1012
1013        if (memcmp(one->sha1, two->sha1, 20)) {
1014                char one_sha1[41];
1015                int abbrev = o->full_index ? 40 : DEFAULT_ABBREV;
1016                memcpy(one_sha1, sha1_to_hex(one->sha1), 41);
1017
1018                len += snprintf(msg + len, sizeof(msg) - len,
1019                                "index %.*s..%.*s",
1020                                abbrev, one_sha1, abbrev,
1021                                sha1_to_hex(two->sha1));
1022                if (one->mode == two->mode)
1023                        len += snprintf(msg + len, sizeof(msg) - len,
1024                                        " %06o", one->mode);
1025                len += snprintf(msg + len, sizeof(msg) - len, "\n");
1026        }
1027
1028        if (len)
1029                msg[--len] = 0;
1030        xfrm_msg = len ? msg : NULL;
1031
1032        if (!pgm &&
1033            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
1034            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
1035                /* a filepair that changes between file and symlink
1036                 * needs to be split into deletion and creation.
1037                 */
1038                struct diff_filespec *null = alloc_filespec(two->path);
1039                run_diff_cmd(NULL, name, other, one, null, xfrm_msg, 0);
1040                free(null);
1041                null = alloc_filespec(one->path);
1042                run_diff_cmd(NULL, name, other, null, two, xfrm_msg, 0);
1043                free(null);
1044        }
1045        else
1046                run_diff_cmd(pgm, name, other, one, two, xfrm_msg,
1047                             complete_rewrite);
1048
1049        free(name_munged);
1050        free(other_munged);
1051}
1052
1053static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
1054                         struct diffstat_t *diffstat)
1055{
1056        const char *name;
1057        const char *other;
1058
1059        if (DIFF_PAIR_UNMERGED(p)) {
1060                /* unmerged */
1061                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat);
1062                return;
1063        }
1064
1065        name = p->one->path;
1066        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1067
1068        diff_fill_sha1_info(p->one);
1069        diff_fill_sha1_info(p->two);
1070
1071        builtin_diffstat(name, other, p->one, p->two, diffstat);
1072}
1073
1074void diff_setup(struct diff_options *options)
1075{
1076        memset(options, 0, sizeof(*options));
1077        options->output_format = DIFF_FORMAT_RAW;
1078        options->line_termination = '\n';
1079        options->break_opt = -1;
1080        options->rename_limit = -1;
1081
1082        options->change = diff_change;
1083        options->add_remove = diff_addremove;
1084}
1085
1086int diff_setup_done(struct diff_options *options)
1087{
1088        if ((options->find_copies_harder &&
1089             options->detect_rename != DIFF_DETECT_COPY) ||
1090            (0 <= options->rename_limit && !options->detect_rename))
1091                return -1;
1092
1093        /*
1094         * These cases always need recursive; we do not drop caller-supplied
1095         * recursive bits for other formats here.
1096         */
1097        if ((options->output_format == DIFF_FORMAT_PATCH) ||
1098            (options->output_format == DIFF_FORMAT_DIFFSTAT))
1099                options->recursive = 1;
1100
1101        if (options->detect_rename && options->rename_limit < 0)
1102                options->rename_limit = diff_rename_limit_default;
1103        if (options->setup & DIFF_SETUP_USE_CACHE) {
1104                if (!active_cache)
1105                        /* read-cache does not die even when it fails
1106                         * so it is safe for us to do this here.  Also
1107                         * it does not smudge active_cache or active_nr
1108                         * when it fails, so we do not have to worry about
1109                         * cleaning it up ourselves either.
1110                         */
1111                        read_cache();
1112        }
1113        if (options->setup & DIFF_SETUP_USE_SIZE_CACHE)
1114                use_size_cache = 1;
1115        if (options->abbrev <= 0 || 40 < options->abbrev)
1116                options->abbrev = 40; /* full */
1117
1118        return 0;
1119}
1120
1121int diff_opt_parse(struct diff_options *options, const char **av, int ac)
1122{
1123        const char *arg = av[0];
1124        if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
1125                options->output_format = DIFF_FORMAT_PATCH;
1126        else if (!strcmp(arg, "--patch-with-raw")) {
1127                options->output_format = DIFF_FORMAT_PATCH;
1128                options->with_raw = 1;
1129        }
1130        else if (!strcmp(arg, "--stat"))
1131                options->output_format = DIFF_FORMAT_DIFFSTAT;
1132        else if (!strcmp(arg, "--patch-with-stat")) {
1133                options->output_format = DIFF_FORMAT_PATCH;
1134                options->with_stat = 1;
1135        }
1136        else if (!strcmp(arg, "-z"))
1137                options->line_termination = 0;
1138        else if (!strncmp(arg, "-l", 2))
1139                options->rename_limit = strtoul(arg+2, NULL, 10);
1140        else if (!strcmp(arg, "--full-index"))
1141                options->full_index = 1;
1142        else if (!strcmp(arg, "--name-only"))
1143                options->output_format = DIFF_FORMAT_NAME;
1144        else if (!strcmp(arg, "--name-status"))
1145                options->output_format = DIFF_FORMAT_NAME_STATUS;
1146        else if (!strcmp(arg, "-R"))
1147                options->reverse_diff = 1;
1148        else if (!strncmp(arg, "-S", 2))
1149                options->pickaxe = arg + 2;
1150        else if (!strcmp(arg, "-s"))
1151                options->output_format = DIFF_FORMAT_NO_OUTPUT;
1152        else if (!strncmp(arg, "-O", 2))
1153                options->orderfile = arg + 2;
1154        else if (!strncmp(arg, "--diff-filter=", 14))
1155                options->filter = arg + 14;
1156        else if (!strcmp(arg, "--pickaxe-all"))
1157                options->pickaxe_opts = DIFF_PICKAXE_ALL;
1158        else if (!strcmp(arg, "--pickaxe-regex"))
1159                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
1160        else if (!strncmp(arg, "-B", 2)) {
1161                if ((options->break_opt =
1162                     diff_scoreopt_parse(arg)) == -1)
1163                        return -1;
1164        }
1165        else if (!strncmp(arg, "-M", 2)) {
1166                if ((options->rename_score =
1167                     diff_scoreopt_parse(arg)) == -1)
1168                        return -1;
1169                options->detect_rename = DIFF_DETECT_RENAME;
1170        }
1171        else if (!strncmp(arg, "-C", 2)) {
1172                if ((options->rename_score =
1173                     diff_scoreopt_parse(arg)) == -1)
1174                        return -1;
1175                options->detect_rename = DIFF_DETECT_COPY;
1176        }
1177        else if (!strcmp(arg, "--find-copies-harder"))
1178                options->find_copies_harder = 1;
1179        else if (!strcmp(arg, "--abbrev"))
1180                options->abbrev = DEFAULT_ABBREV;
1181        else if (!strncmp(arg, "--abbrev=", 9)) {
1182                options->abbrev = strtoul(arg + 9, NULL, 10);
1183                if (options->abbrev < MINIMUM_ABBREV)
1184                        options->abbrev = MINIMUM_ABBREV;
1185                else if (40 < options->abbrev)
1186                        options->abbrev = 40;
1187        }
1188        else
1189                return 0;
1190        return 1;
1191}
1192
1193static int parse_num(const char **cp_p)
1194{
1195        unsigned long num, scale;
1196        int ch, dot;
1197        const char *cp = *cp_p;
1198
1199        num = 0;
1200        scale = 1;
1201        dot = 0;
1202        for(;;) {
1203                ch = *cp;
1204                if ( !dot && ch == '.' ) {
1205                        scale = 1;
1206                        dot = 1;
1207                } else if ( ch == '%' ) {
1208                        scale = dot ? scale*100 : 100;
1209                        cp++;   /* % is always at the end */
1210                        break;
1211                } else if ( ch >= '0' && ch <= '9' ) {
1212                        if ( scale < 100000 ) {
1213                                scale *= 10;
1214                                num = (num*10) + (ch-'0');
1215                        }
1216                } else {
1217                        break;
1218                }
1219                cp++;
1220        }
1221        *cp_p = cp;
1222
1223        /* user says num divided by scale and we say internally that
1224         * is MAX_SCORE * num / scale.
1225         */
1226        return (num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale);
1227}
1228
1229int diff_scoreopt_parse(const char *opt)
1230{
1231        int opt1, opt2, cmd;
1232
1233        if (*opt++ != '-')
1234                return -1;
1235        cmd = *opt++;
1236        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
1237                return -1; /* that is not a -M, -C nor -B option */
1238
1239        opt1 = parse_num(&opt);
1240        if (cmd != 'B')
1241                opt2 = 0;
1242        else {
1243                if (*opt == 0)
1244                        opt2 = 0;
1245                else if (*opt != '/')
1246                        return -1; /* we expect -B80/99 or -B80 */
1247                else {
1248                        opt++;
1249                        opt2 = parse_num(&opt);
1250                }
1251        }
1252        if (*opt != 0)
1253                return -1;
1254        return opt1 | (opt2 << 16);
1255}
1256
1257struct diff_queue_struct diff_queued_diff;
1258
1259void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
1260{
1261        if (queue->alloc <= queue->nr) {
1262                queue->alloc = alloc_nr(queue->alloc);
1263                queue->queue = xrealloc(queue->queue,
1264                                        sizeof(dp) * queue->alloc);
1265        }
1266        queue->queue[queue->nr++] = dp;
1267}
1268
1269struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
1270                                 struct diff_filespec *one,
1271                                 struct diff_filespec *two)
1272{
1273        struct diff_filepair *dp = xmalloc(sizeof(*dp));
1274        dp->one = one;
1275        dp->two = two;
1276        dp->score = 0;
1277        dp->status = 0;
1278        dp->source_stays = 0;
1279        dp->broken_pair = 0;
1280        if (queue)
1281                diff_q(queue, dp);
1282        return dp;
1283}
1284
1285void diff_free_filepair(struct diff_filepair *p)
1286{
1287        diff_free_filespec_data(p->one);
1288        diff_free_filespec_data(p->two);
1289        free(p->one);
1290        free(p->two);
1291        free(p);
1292}
1293
1294/* This is different from find_unique_abbrev() in that
1295 * it stuffs the result with dots for alignment.
1296 */
1297const char *diff_unique_abbrev(const unsigned char *sha1, int len)
1298{
1299        int abblen;
1300        const char *abbrev;
1301        if (len == 40)
1302                return sha1_to_hex(sha1);
1303
1304        abbrev = find_unique_abbrev(sha1, len);
1305        if (!abbrev)
1306                return sha1_to_hex(sha1);
1307        abblen = strlen(abbrev);
1308        if (abblen < 37) {
1309                static char hex[41];
1310                if (len < abblen && abblen <= len + 2)
1311                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
1312                else
1313                        sprintf(hex, "%s...", abbrev);
1314                return hex;
1315        }
1316        return sha1_to_hex(sha1);
1317}
1318
1319static void diff_flush_raw(struct diff_filepair *p,
1320                           int line_termination,
1321                           int inter_name_termination,
1322                           struct diff_options *options,
1323                           int output_format)
1324{
1325        int two_paths;
1326        char status[10];
1327        int abbrev = options->abbrev;
1328        const char *path_one, *path_two;
1329
1330        path_one = p->one->path;
1331        path_two = p->two->path;
1332        if (line_termination) {
1333                path_one = quote_one(path_one);
1334                path_two = quote_one(path_two);
1335        }
1336
1337        if (p->score)
1338                sprintf(status, "%c%03d", p->status,
1339                        (int)(0.5 + p->score * 100.0/MAX_SCORE));
1340        else {
1341                status[0] = p->status;
1342                status[1] = 0;
1343        }
1344        switch (p->status) {
1345        case DIFF_STATUS_COPIED:
1346        case DIFF_STATUS_RENAMED:
1347                two_paths = 1;
1348                break;
1349        case DIFF_STATUS_ADDED:
1350        case DIFF_STATUS_DELETED:
1351                two_paths = 0;
1352                break;
1353        default:
1354                two_paths = 0;
1355                break;
1356        }
1357        if (output_format != DIFF_FORMAT_NAME_STATUS) {
1358                printf(":%06o %06o %s ",
1359                       p->one->mode, p->two->mode,
1360                       diff_unique_abbrev(p->one->sha1, abbrev));
1361                printf("%s ",
1362                       diff_unique_abbrev(p->two->sha1, abbrev));
1363        }
1364        printf("%s%c%s", status, inter_name_termination, path_one);
1365        if (two_paths)
1366                printf("%c%s", inter_name_termination, path_two);
1367        putchar(line_termination);
1368        if (path_one != p->one->path)
1369                free((void*)path_one);
1370        if (path_two != p->two->path)
1371                free((void*)path_two);
1372}
1373
1374static void diff_flush_name(struct diff_filepair *p,
1375                            int inter_name_termination,
1376                            int line_termination)
1377{
1378        char *path = p->two->path;
1379
1380        if (line_termination)
1381                path = quote_one(p->two->path);
1382        else
1383                path = p->two->path;
1384        printf("%s%c", path, line_termination);
1385        if (p->two->path != path)
1386                free(path);
1387}
1388
1389int diff_unmodified_pair(struct diff_filepair *p)
1390{
1391        /* This function is written stricter than necessary to support
1392         * the currently implemented transformers, but the idea is to
1393         * let transformers to produce diff_filepairs any way they want,
1394         * and filter and clean them up here before producing the output.
1395         */
1396        struct diff_filespec *one, *two;
1397
1398        if (DIFF_PAIR_UNMERGED(p))
1399                return 0; /* unmerged is interesting */
1400
1401        one = p->one;
1402        two = p->two;
1403
1404        /* deletion, addition, mode or type change
1405         * and rename are all interesting.
1406         */
1407        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
1408            DIFF_PAIR_MODE_CHANGED(p) ||
1409            strcmp(one->path, two->path))
1410                return 0;
1411
1412        /* both are valid and point at the same path.  that is, we are
1413         * dealing with a change.
1414         */
1415        if (one->sha1_valid && two->sha1_valid &&
1416            !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
1417                return 1; /* no change */
1418        if (!one->sha1_valid && !two->sha1_valid)
1419                return 1; /* both look at the same file on the filesystem. */
1420        return 0;
1421}
1422
1423static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
1424{
1425        if (diff_unmodified_pair(p))
1426                return;
1427
1428        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1429            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1430                return; /* no tree diffs in patch format */
1431
1432        run_diff(p, o);
1433}
1434
1435static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
1436                            struct diffstat_t *diffstat)
1437{
1438        if (diff_unmodified_pair(p))
1439                return;
1440
1441        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1442            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1443                return; /* no tree diffs in patch format */
1444
1445        run_diffstat(p, o, diffstat);
1446}
1447
1448int diff_queue_is_empty(void)
1449{
1450        struct diff_queue_struct *q = &diff_queued_diff;
1451        int i;
1452        for (i = 0; i < q->nr; i++)
1453                if (!diff_unmodified_pair(q->queue[i]))
1454                        return 0;
1455        return 1;
1456}
1457
1458#if DIFF_DEBUG
1459void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
1460{
1461        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
1462                x, one ? one : "",
1463                s->path,
1464                DIFF_FILE_VALID(s) ? "valid" : "invalid",
1465                s->mode,
1466                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
1467        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
1468                x, one ? one : "",
1469                s->size, s->xfrm_flags);
1470}
1471
1472void diff_debug_filepair(const struct diff_filepair *p, int i)
1473{
1474        diff_debug_filespec(p->one, i, "one");
1475        diff_debug_filespec(p->two, i, "two");
1476        fprintf(stderr, "score %d, status %c stays %d broken %d\n",
1477                p->score, p->status ? p->status : '?',
1478                p->source_stays, p->broken_pair);
1479}
1480
1481void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
1482{
1483        int i;
1484        if (msg)
1485                fprintf(stderr, "%s\n", msg);
1486        fprintf(stderr, "q->nr = %d\n", q->nr);
1487        for (i = 0; i < q->nr; i++) {
1488                struct diff_filepair *p = q->queue[i];
1489                diff_debug_filepair(p, i);
1490        }
1491}
1492#endif
1493
1494static void diff_resolve_rename_copy(void)
1495{
1496        int i, j;
1497        struct diff_filepair *p, *pp;
1498        struct diff_queue_struct *q = &diff_queued_diff;
1499
1500        diff_debug_queue("resolve-rename-copy", q);
1501
1502        for (i = 0; i < q->nr; i++) {
1503                p = q->queue[i];
1504                p->status = 0; /* undecided */
1505                if (DIFF_PAIR_UNMERGED(p))
1506                        p->status = DIFF_STATUS_UNMERGED;
1507                else if (!DIFF_FILE_VALID(p->one))
1508                        p->status = DIFF_STATUS_ADDED;
1509                else if (!DIFF_FILE_VALID(p->two))
1510                        p->status = DIFF_STATUS_DELETED;
1511                else if (DIFF_PAIR_TYPE_CHANGED(p))
1512                        p->status = DIFF_STATUS_TYPE_CHANGED;
1513
1514                /* from this point on, we are dealing with a pair
1515                 * whose both sides are valid and of the same type, i.e.
1516                 * either in-place edit or rename/copy edit.
1517                 */
1518                else if (DIFF_PAIR_RENAME(p)) {
1519                        if (p->source_stays) {
1520                                p->status = DIFF_STATUS_COPIED;
1521                                continue;
1522                        }
1523                        /* See if there is some other filepair that
1524                         * copies from the same source as us.  If so
1525                         * we are a copy.  Otherwise we are either a
1526                         * copy if the path stays, or a rename if it
1527                         * does not, but we already handled "stays" case.
1528                         */
1529                        for (j = i + 1; j < q->nr; j++) {
1530                                pp = q->queue[j];
1531                                if (strcmp(pp->one->path, p->one->path))
1532                                        continue; /* not us */
1533                                if (!DIFF_PAIR_RENAME(pp))
1534                                        continue; /* not a rename/copy */
1535                                /* pp is a rename/copy from the same source */
1536                                p->status = DIFF_STATUS_COPIED;
1537                                break;
1538                        }
1539                        if (!p->status)
1540                                p->status = DIFF_STATUS_RENAMED;
1541                }
1542                else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
1543                         p->one->mode != p->two->mode)
1544                        p->status = DIFF_STATUS_MODIFIED;
1545                else {
1546                        /* This is a "no-change" entry and should not
1547                         * happen anymore, but prepare for broken callers.
1548                         */
1549                        error("feeding unmodified %s to diffcore",
1550                              p->one->path);
1551                        p->status = DIFF_STATUS_UNKNOWN;
1552                }
1553        }
1554        diff_debug_queue("resolve-rename-copy done", q);
1555}
1556
1557static void flush_one_pair(struct diff_filepair *p,
1558                           int diff_output_format,
1559                           struct diff_options *options,
1560                           struct diffstat_t *diffstat)
1561{
1562        int inter_name_termination = '\t';
1563        int line_termination = options->line_termination;
1564        if (!line_termination)
1565                inter_name_termination = 0;
1566
1567        switch (p->status) {
1568        case DIFF_STATUS_UNKNOWN:
1569                break;
1570        case 0:
1571                die("internal error in diff-resolve-rename-copy");
1572                break;
1573        default:
1574                switch (diff_output_format) {
1575                case DIFF_FORMAT_DIFFSTAT:
1576                        diff_flush_stat(p, options, diffstat);
1577                        break;
1578                case DIFF_FORMAT_PATCH:
1579                        diff_flush_patch(p, options);
1580                        break;
1581                case DIFF_FORMAT_RAW:
1582                case DIFF_FORMAT_NAME_STATUS:
1583                        diff_flush_raw(p, line_termination,
1584                                       inter_name_termination,
1585                                       options, diff_output_format);
1586                        break;
1587                case DIFF_FORMAT_NAME:
1588                        diff_flush_name(p,
1589                                        inter_name_termination,
1590                                        line_termination);
1591                        break;
1592                case DIFF_FORMAT_NO_OUTPUT:
1593                        break;
1594                }
1595        }
1596}
1597
1598void diff_flush(struct diff_options *options)
1599{
1600        struct diff_queue_struct *q = &diff_queued_diff;
1601        int i;
1602        int diff_output_format = options->output_format;
1603        struct diffstat_t *diffstat = NULL;
1604
1605        if (diff_output_format == DIFF_FORMAT_DIFFSTAT || options->with_stat) {
1606                diffstat = xcalloc(sizeof (struct diffstat_t), 1);
1607                diffstat->xm.consume = diffstat_consume;
1608        }
1609
1610        if (options->with_raw) {
1611                for (i = 0; i < q->nr; i++) {
1612                        struct diff_filepair *p = q->queue[i];
1613                        flush_one_pair(p, DIFF_FORMAT_RAW, options, NULL);
1614                }
1615                putchar(options->line_termination);
1616        }
1617        if (options->with_stat) {
1618                for (i = 0; i < q->nr; i++) {
1619                        struct diff_filepair *p = q->queue[i];
1620                        flush_one_pair(p, DIFF_FORMAT_DIFFSTAT, options,
1621                                       diffstat);
1622                }
1623                show_stats(diffstat);
1624                free(diffstat);
1625                diffstat = NULL;
1626                putchar(options->line_termination);
1627        }
1628        for (i = 0; i < q->nr; i++) {
1629                struct diff_filepair *p = q->queue[i];
1630                flush_one_pair(p, diff_output_format, options, diffstat);
1631                diff_free_filepair(p);
1632        }
1633
1634        if (diffstat) {
1635                show_stats(diffstat);
1636                free(diffstat);
1637        }
1638
1639        free(q->queue);
1640        q->queue = NULL;
1641        q->nr = q->alloc = 0;
1642}
1643
1644static void diffcore_apply_filter(const char *filter)
1645{
1646        int i;
1647        struct diff_queue_struct *q = &diff_queued_diff;
1648        struct diff_queue_struct outq;
1649        outq.queue = NULL;
1650        outq.nr = outq.alloc = 0;
1651
1652        if (!filter)
1653                return;
1654
1655        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
1656                int found;
1657                for (i = found = 0; !found && i < q->nr; i++) {
1658                        struct diff_filepair *p = q->queue[i];
1659                        if (((p->status == DIFF_STATUS_MODIFIED) &&
1660                             ((p->score &&
1661                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1662                              (!p->score &&
1663                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1664                            ((p->status != DIFF_STATUS_MODIFIED) &&
1665                             strchr(filter, p->status)))
1666                                found++;
1667                }
1668                if (found)
1669                        return;
1670
1671                /* otherwise we will clear the whole queue
1672                 * by copying the empty outq at the end of this
1673                 * function, but first clear the current entries
1674                 * in the queue.
1675                 */
1676                for (i = 0; i < q->nr; i++)
1677                        diff_free_filepair(q->queue[i]);
1678        }
1679        else {
1680                /* Only the matching ones */
1681                for (i = 0; i < q->nr; i++) {
1682                        struct diff_filepair *p = q->queue[i];
1683
1684                        if (((p->status == DIFF_STATUS_MODIFIED) &&
1685                             ((p->score &&
1686                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1687                              (!p->score &&
1688                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1689                            ((p->status != DIFF_STATUS_MODIFIED) &&
1690                             strchr(filter, p->status)))
1691                                diff_q(&outq, p);
1692                        else
1693                                diff_free_filepair(p);
1694                }
1695        }
1696        free(q->queue);
1697        *q = outq;
1698}
1699
1700void diffcore_std(struct diff_options *options)
1701{
1702        if (options->break_opt != -1)
1703                diffcore_break(options->break_opt);
1704        if (options->detect_rename)
1705                diffcore_rename(options);
1706        if (options->break_opt != -1)
1707                diffcore_merge_broken();
1708        if (options->pickaxe)
1709                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
1710        if (options->orderfile)
1711                diffcore_order(options->orderfile);
1712        diff_resolve_rename_copy();
1713        diffcore_apply_filter(options->filter);
1714}
1715
1716
1717void diffcore_std_no_resolve(struct diff_options *options)
1718{
1719        if (options->pickaxe)
1720                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
1721        if (options->orderfile)
1722                diffcore_order(options->orderfile);
1723        diffcore_apply_filter(options->filter);
1724}
1725
1726void diff_addremove(struct diff_options *options,
1727                    int addremove, unsigned mode,
1728                    const unsigned char *sha1,
1729                    const char *base, const char *path)
1730{
1731        char concatpath[PATH_MAX];
1732        struct diff_filespec *one, *two;
1733
1734        /* This may look odd, but it is a preparation for
1735         * feeding "there are unchanged files which should
1736         * not produce diffs, but when you are doing copy
1737         * detection you would need them, so here they are"
1738         * entries to the diff-core.  They will be prefixed
1739         * with something like '=' or '*' (I haven't decided
1740         * which but should not make any difference).
1741         * Feeding the same new and old to diff_change() 
1742         * also has the same effect.
1743         * Before the final output happens, they are pruned after
1744         * merged into rename/copy pairs as appropriate.
1745         */
1746        if (options->reverse_diff)
1747                addremove = (addremove == '+' ? '-' :
1748                             addremove == '-' ? '+' : addremove);
1749
1750        if (!path) path = "";
1751        sprintf(concatpath, "%s%s", base, path);
1752        one = alloc_filespec(concatpath);
1753        two = alloc_filespec(concatpath);
1754
1755        if (addremove != '+')
1756                fill_filespec(one, sha1, mode);
1757        if (addremove != '-')
1758                fill_filespec(two, sha1, mode);
1759
1760        diff_queue(&diff_queued_diff, one, two);
1761}
1762
1763void diff_change(struct diff_options *options,
1764                 unsigned old_mode, unsigned new_mode,
1765                 const unsigned char *old_sha1,
1766                 const unsigned char *new_sha1,
1767                 const char *base, const char *path) 
1768{
1769        char concatpath[PATH_MAX];
1770        struct diff_filespec *one, *two;
1771
1772        if (options->reverse_diff) {
1773                unsigned tmp;
1774                const unsigned char *tmp_c;
1775                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
1776                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
1777        }
1778        if (!path) path = "";
1779        sprintf(concatpath, "%s%s", base, path);
1780        one = alloc_filespec(concatpath);
1781        two = alloc_filespec(concatpath);
1782        fill_filespec(one, old_sha1, old_mode);
1783        fill_filespec(two, new_sha1, new_mode);
1784
1785        diff_queue(&diff_queued_diff, one, two);
1786}
1787
1788void diff_unmerge(struct diff_options *options,
1789                  const char *path)
1790{
1791        struct diff_filespec *one, *two;
1792        one = alloc_filespec(path);
1793        two = alloc_filespec(path);
1794        diff_queue(&diff_queued_diff, one, two);
1795}