diff.c

   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/xdiff.h"
  12
  13 static int use_size_cache;
  14
  15 int diff_rename_limit_default = -1;
  16
  17 int 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
  27 static 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
  42 static 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
  67 static 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
  81 static 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
  88 static 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
 111 static 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
 126 static 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
 143 static 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         /* Use temp[i].name as input, name_a and name_b as labels */
 149         int lc_a, lc_b;
 150         lc_a = count_lines(one->data, one->size);
 151         lc_b = count_lines(two->data, two->size);
 152         printf("--- %s\n+++ %s\n@@ -", name_a, name_b);
 153         print_line_count(lc_a);
 154         printf(" +");
 155         print_line_count(lc_b);
 156         printf(" @@\n");
 157         if (lc_a)
 158                 copy_file('-', one->data, one->size);
 159         if (lc_b)
 160                 copy_file('+', two->data, two->size);
 161 }
 162
 163 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 164 {
 165         if (!DIFF_FILE_VALID(one)) {
 166                 mf->ptr = ""; /* does not matter */
 167                 mf->size = 0;
 168                 return 0;
 169         }
 170         else if (diff_populate_filespec(one, 0))
 171                 return -1;
 172         mf->ptr = one->data;
 173         mf->size = one->size;
 174         return 0;
 175 }
 176
 177 struct emit_callback {
 178         const char **label_path;
 179 };
 180
 181 static int fn_out(void *priv, mmbuffer_t *mb, int nbuf)
 182 {
 183         int i;
 184         struct emit_callback *ecbdata = priv;
 185
 186         if (ecbdata->label_path[0]) {
 187                 printf("--- %s\n", ecbdata->label_path[0]);
 188                 printf("+++ %s\n", ecbdata->label_path[1]);
 189                 ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 190         }
 191         for (i = 0; i < nbuf; i++)
 192                 if (!fwrite(mb[i].ptr, mb[i].size, 1, stdout))
 193                         return -1;
 194         return 0;
 195 }
 196
 197 #define FIRST_FEW_BYTES 8000
 198 static int mmfile_is_binary(mmfile_t *mf)
 199 {
 200         long sz = mf->size;
 201         if (FIRST_FEW_BYTES < sz)
 202                 sz = FIRST_FEW_BYTES;
 203         if (memchr(mf->ptr, 0, sz))
 204                 return 1;
 205         return 0;
 206 }
 207
 208 static void builtin_diff(const char *name_a,
 209                          const char *name_b,
 210                          struct diff_filespec *one,
 211                          struct diff_filespec *two,
 212                          const char *xfrm_msg,
 213                          int complete_rewrite)
 214 {
 215         mmfile_t mf1, mf2;
 216         const char *lbl[2];
 217         char *a_one, *b_two;
 218
 219         a_one = quote_two("a/", name_a);
 220         b_two = quote_two("b/", name_b);
 221         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
 222         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
 223         printf("diff --git %s %s\n", a_one, b_two);
 224         if (lbl[0][0] == '/') {
 225                 /* /dev/null */
 226                 printf("new file mode %06o\n", two->mode);
 227                 if (xfrm_msg && xfrm_msg[0])
 228                         puts(xfrm_msg);
 229         }
 230         else if (lbl[1][0] == '/') {
 231                 printf("deleted file mode %06o\n", one->mode);
 232                 if (xfrm_msg && xfrm_msg[0])
 233                         puts(xfrm_msg);
 234         }
 235         else {
 236                 if (one->mode != two->mode) {
 237                         printf("old mode %06o\n", one->mode);
 238                         printf("new mode %06o\n", two->mode);
 239                 }
 240                 if (xfrm_msg && xfrm_msg[0])
 241                         puts(xfrm_msg);
 242                 /*
 243                  * we do not run diff between different kind
 244                  * of objects.
 245                  */
 246                 if ((one->mode ^ two->mode) & S_IFMT)
 247                         goto free_ab_and_return;
 248                 if (complete_rewrite) {
 249                         emit_rewrite_diff(name_a, name_b, one, two);
 250                         goto free_ab_and_return;
 251                 }
 252         }
 253
 254         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
 255                 die("unable to read files to diff");
 256
 257         if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))
 258                 printf("Binary files %s and %s differ\n", lbl[0], lbl[1]);
 259         else {
 260                 /* Crazy xdl interfaces.. */
 261                 const char *diffopts = getenv("GIT_DIFF_OPTS");
 262                 xpparam_t xpp;
 263                 xdemitconf_t xecfg;
 264                 xdemitcb_t ecb;
 265                 struct emit_callback ecbdata;
 266
 267                 ecbdata.label_path = lbl;
 268                 xpp.flags = XDF_NEED_MINIMAL;
 269                 xecfg.ctxlen = 3;
 270                 xecfg.flags = XDL_EMIT_FUNCNAMES;
 271                 if (!diffopts)
 272                         ;
 273                 else if (!strncmp(diffopts, "--unified=", 10))
 274                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
 275                 else if (!strncmp(diffopts, "-u", 2))
 276                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
 277                 ecb.outf = fn_out;
 278                 ecb.priv = &ecbdata;
 279                 xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
 280         }
 281
 282  free_ab_and_return:
 283         free(a_one);
 284         free(b_two);
 285         return;
 286 }
 287
 288 struct diff_filespec *alloc_filespec(const char *path)
 289 {
 290         int namelen = strlen(path);
 291         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
 292
 293         memset(spec, 0, sizeof(*spec));
 294         spec->path = (char *)(spec + 1);
 295         memcpy(spec->path, path, namelen+1);
 296         return spec;
 297 }
 298
 299 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
 300                    unsigned short mode)
 301 {
 302         if (mode) {
 303                 spec->mode = DIFF_FILE_CANON_MODE(mode);
 304                 memcpy(spec->sha1, sha1, 20);
 305                 spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
 306         }
 307 }
 308
 309 /*
 310  * Given a name and sha1 pair, if the dircache tells us the file in
 311  * the work tree has that object contents, return true, so that
 312  * prepare_temp_file() does not have to inflate and extract.
 313  */
 314 static int work_tree_matches(const char *name, const unsigned char *sha1)
 315 {
 316         struct cache_entry *ce;
 317         struct stat st;
 318         int pos, len;
 319
 320         /* We do not read the cache ourselves here, because the
 321          * benchmark with my previous version that always reads cache
 322          * shows that it makes things worse for diff-tree comparing
 323          * two linux-2.6 kernel trees in an already checked out work
 324          * tree.  This is because most diff-tree comparisons deal with
 325          * only a small number of files, while reading the cache is
 326          * expensive for a large project, and its cost outweighs the
 327          * savings we get by not inflating the object to a temporary
 328          * file.  Practically, this code only helps when we are used
 329          * by diff-cache --cached, which does read the cache before
 330          * calling us.
 331          */
 332         if (!active_cache)
 333                 return 0;
 334
 335         len = strlen(name);
 336         pos = cache_name_pos(name, len);
 337         if (pos < 0)
 338                 return 0;
 339         ce = active_cache[pos];
 340         if ((lstat(name, &st) < 0) ||
 341             !S_ISREG(st.st_mode) || /* careful! */
 342             ce_match_stat(ce, &st, 0) ||
 343             memcmp(sha1, ce->sha1, 20))
 344                 return 0;
 345         /* we return 1 only when we can stat, it is a regular file,
 346          * stat information matches, and sha1 recorded in the cache
 347          * matches.  I.e. we know the file in the work tree really is
 348          * the same as the <name, sha1> pair.
 349          */
 350         return 1;
 351 }
 352
 353 static struct sha1_size_cache {
 354         unsigned char sha1[20];
 355         unsigned long size;
 356 } **sha1_size_cache;
 357 static int sha1_size_cache_nr, sha1_size_cache_alloc;
 358
 359 static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
 360                                                  int find_only,
 361                                                  unsigned long size)
 362 {
 363         int first, last;
 364         struct sha1_size_cache *e;
 365
 366         first = 0;
 367         last = sha1_size_cache_nr;
 368         while (last > first) {
 369                 int cmp, next = (last + first) >> 1;
 370                 e = sha1_size_cache[next];
 371                 cmp = memcmp(e->sha1, sha1, 20);
 372                 if (!cmp)
 373                         return e;
 374                 if (cmp < 0) {
 375                         last = next;
 376                         continue;
 377                 }
 378                 first = next+1;
 379         }
 380         /* not found */
 381         if (find_only)
 382                 return NULL;
 383         /* insert to make it at "first" */
 384         if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
 385                 sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
 386                 sha1_size_cache = xrealloc(sha1_size_cache,
 387                                            sha1_size_cache_alloc *
 388                                            sizeof(*sha1_size_cache));
 389         }
 390         sha1_size_cache_nr++;
 391         if (first < sha1_size_cache_nr)
 392                 memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
 393                         (sha1_size_cache_nr - first - 1) *
 394                         sizeof(*sha1_size_cache));
 395         e = xmalloc(sizeof(struct sha1_size_cache));
 396         sha1_size_cache[first] = e;
 397         memcpy(e->sha1, sha1, 20);
 398         e->size = size;
 399         return e;
 400 }
 401
 402 /*
 403  * While doing rename detection and pickaxe operation, we may need to
 404  * grab the data for the blob (or file) for our own in-core comparison.
 405  * diff_filespec has data and size fields for this purpose.
 406  */
 407 int diff_populate_filespec(struct diff_filespec *s, int size_only)
 408 {
 409         int err = 0;
 410         if (!DIFF_FILE_VALID(s))
 411                 die("internal error: asking to populate invalid file.");
 412         if (S_ISDIR(s->mode))
 413                 return -1;
 414
 415         if (!use_size_cache)
 416                 size_only = 0;
 417
 418         if (s->data)
 419                 return err;
 420         if (!s->sha1_valid ||
 421             work_tree_matches(s->path, s->sha1)) {
 422                 struct stat st;
 423                 int fd;
 424                 if (lstat(s->path, &st) < 0) {
 425                         if (errno == ENOENT) {
 426                         err_empty:
 427                                 err = -1;
 428                         empty:
 429                                 s->data = "";
 430                                 s->size = 0;
 431                                 return err;
 432                         }
 433                 }
 434                 s->size = st.st_size;
 435                 if (!s->size)
 436                         goto empty;
 437                 if (size_only)
 438                         return 0;
 439                 if (S_ISLNK(st.st_mode)) {
 440                         int ret;
 441                         s->data = xmalloc(s->size);
 442                         s->should_free = 1;
 443                         ret = readlink(s->path, s->data, s->size);
 444                         if (ret < 0) {
 445                                 free(s->data);
 446                                 goto err_empty;
 447                         }
 448                         return 0;
 449                 }
 450                 fd = open(s->path, O_RDONLY);
 451                 if (fd < 0)
 452                         goto err_empty;
 453                 s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
 454                 close(fd);
 455                 if (s->data == MAP_FAILED)
 456                         goto err_empty;
 457                 s->should_munmap = 1;
 458         }
 459         else {
 460                 char type[20];
 461                 struct sha1_size_cache *e;
 462
 463                 if (size_only) {
 464                         e = locate_size_cache(s->sha1, 1, 0);
 465                         if (e) {
 466                                 s->size = e->size;
 467                                 return 0;
 468                         }
 469                         if (!sha1_object_info(s->sha1, type, &s->size))
 470                                 locate_size_cache(s->sha1, 0, s->size);
 471                 }
 472                 else {
 473                         s->data = read_sha1_file(s->sha1, type, &s->size);
 474                         s->should_free = 1;
 475                 }
 476         }
 477         return 0;
 478 }
 479
 480 void diff_free_filespec_data(struct diff_filespec *s)
 481 {
 482         if (s->should_free)
 483                 free(s->data);
 484         else if (s->should_munmap)
 485                 munmap(s->data, s->size);
 486         s->should_free = s->should_munmap = 0;
 487         s->data = NULL;
 488         free(s->cnt_data);
 489         s->cnt_data = NULL;
 490 }
 491
 492 static void prep_temp_blob(struct diff_tempfile *temp,
 493                            void *blob,
 494                            unsigned long size,
 495                            const unsigned char *sha1,
 496                            int mode)
 497 {
 498         int fd;
 499
 500         fd = git_mkstemp(temp->tmp_path, TEMPFILE_PATH_LEN, ".diff_XXXXXX");
 501         if (fd < 0)
 502                 die("unable to create temp-file");
 503         if (write(fd, blob, size) != size)
 504                 die("unable to write temp-file");
 505         close(fd);
 506         temp->name = temp->tmp_path;
 507         strcpy(temp->hex, sha1_to_hex(sha1));
 508         temp->hex[40] = 0;
 509         sprintf(temp->mode, "%06o", mode);
 510 }
 511
 512 static void prepare_temp_file(const char *name,
 513                               struct diff_tempfile *temp,
 514                               struct diff_filespec *one)
 515 {
 516         if (!DIFF_FILE_VALID(one)) {
 517         not_a_valid_file:
 518                 /* A '-' entry produces this for file-2, and
 519                  * a '+' entry produces this for file-1.
 520                  */
 521                 temp->name = "/dev/null";
 522                 strcpy(temp->hex, ".");
 523                 strcpy(temp->mode, ".");
 524                 return;
 525         }
 526
 527         if (!one->sha1_valid ||
 528             work_tree_matches(name, one->sha1)) {
 529                 struct stat st;
 530                 if (lstat(name, &st) < 0) {
 531                         if (errno == ENOENT)
 532                                 goto not_a_valid_file;
 533                         die("stat(%s): %s", name, strerror(errno));
 534                 }
 535                 if (S_ISLNK(st.st_mode)) {
 536                         int ret;
 537                         char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
 538                         if (sizeof(buf) <= st.st_size)
 539                                 die("symlink too long: %s", name);
 540                         ret = readlink(name, buf, st.st_size);
 541                         if (ret < 0)
 542                                 die("readlink(%s)", name);
 543                         prep_temp_blob(temp, buf, st.st_size,
 544                                        (one->sha1_valid ?
 545                                         one->sha1 : null_sha1),
 546                                        (one->sha1_valid ?
 547                                         one->mode : S_IFLNK));
 548                 }
 549                 else {
 550                         /* we can borrow from the file in the work tree */
 551                         temp->name = name;
 552                         if (!one->sha1_valid)
 553                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
 554                         else
 555                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
 556                         /* Even though we may sometimes borrow the
 557                          * contents from the work tree, we always want
 558                          * one->mode.  mode is trustworthy even when
 559                          * !(one->sha1_valid), as long as
 560                          * DIFF_FILE_VALID(one).
 561                          */
 562                         sprintf(temp->mode, "%06o", one->mode);
 563                 }
 564                 return;
 565         }
 566         else {
 567                 if (diff_populate_filespec(one, 0))
 568                         die("cannot read data blob for %s", one->path);
 569                 prep_temp_blob(temp, one->data, one->size,
 570                                one->sha1, one->mode);
 571         }
 572 }
 573
 574 static void remove_tempfile(void)
 575 {
 576         int i;
 577
 578         for (i = 0; i < 2; i++)
 579                 if (diff_temp[i].name == diff_temp[i].tmp_path) {
 580                         unlink(diff_temp[i].name);
 581                         diff_temp[i].name = NULL;
 582                 }
 583 }
 584
 585 static void remove_tempfile_on_signal(int signo)
 586 {
 587         remove_tempfile();
 588         signal(SIGINT, SIG_DFL);
 589         raise(signo);
 590 }
 591
 592 static int spawn_prog(const char *pgm, const char **arg)
 593 {
 594         pid_t pid;
 595         int status;
 596
 597         fflush(NULL);
 598         pid = fork();
 599         if (pid < 0)
 600                 die("unable to fork");
 601         if (!pid) {
 602                 execvp(pgm, (char *const*) arg);
 603                 exit(255);
 604         }
 605
 606         while (waitpid(pid, &status, 0) < 0) {
 607                 if (errno == EINTR)
 608                         continue;
 609                 return -1;
 610         }
 611
 612         /* Earlier we did not check the exit status because
 613          * diff exits non-zero if files are different, and
 614          * we are not interested in knowing that.  It was a
 615          * mistake which made it harder to quit a diff-*
 616          * session that uses the git-apply-patch-script as
 617          * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
 618          * should also exit non-zero only when it wants to
 619          * abort the entire diff-* session.
 620          */
 621         if (WIFEXITED(status) && !WEXITSTATUS(status))
 622                 return 0;
 623         return -1;
 624 }
 625
 626 /* An external diff command takes:
 627  *
 628  * diff-cmd name infile1 infile1-sha1 infile1-mode \
 629  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
 630  *
 631  */
 632 static void run_external_diff(const char *pgm,
 633                               const char *name,
 634                               const char *other,
 635                               struct diff_filespec *one,
 636                               struct diff_filespec *two,
 637                               const char *xfrm_msg,
 638                               int complete_rewrite)
 639 {
 640         const char *spawn_arg[10];
 641         struct diff_tempfile *temp = diff_temp;
 642         int retval;
 643         static int atexit_asked = 0;
 644         const char *othername;
 645         const char **arg = &spawn_arg[0];
 646
 647         othername = (other? other : name);
 648         if (one && two) {
 649                 prepare_temp_file(name, &temp[0], one);
 650                 prepare_temp_file(othername, &temp[1], two);
 651                 if (! atexit_asked &&
 652                     (temp[0].name == temp[0].tmp_path ||
 653                      temp[1].name == temp[1].tmp_path)) {
 654                         atexit_asked = 1;
 655                         atexit(remove_tempfile);
 656                 }
 657                 signal(SIGINT, remove_tempfile_on_signal);
 658         }
 659
 660         if (one && two) {
 661                 *arg++ = pgm;
 662                 *arg++ = name;
 663                 *arg++ = temp[0].name;
 664                 *arg++ = temp[0].hex;
 665                 *arg++ = temp[0].mode;
 666                 *arg++ = temp[1].name;
 667                 *arg++ = temp[1].hex;
 668                 *arg++ = temp[1].mode;
 669                 if (other) {
 670                         *arg++ = other;
 671                         *arg++ = xfrm_msg;
 672                 }
 673         } else {
 674                 *arg++ = pgm;
 675                 *arg++ = name;
 676         }
 677         *arg = NULL;
 678         retval = spawn_prog(pgm, spawn_arg);
 679         remove_tempfile();
 680         if (retval) {
 681                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
 682                 exit(1);
 683         }
 684 }
 685
 686 static void run_diff_cmd(const char *pgm,
 687                          const char *name,
 688                          const char *other,
 689                          struct diff_filespec *one,
 690                          struct diff_filespec *two,
 691                          const char *xfrm_msg,
 692                          int complete_rewrite)
 693 {
 694         if (pgm) {
 695                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
 696                                   complete_rewrite);
 697                 return;
 698         }
 699         if (one && two)
 700                 builtin_diff(name, other ? other : name,
 701                              one, two, xfrm_msg, complete_rewrite);
 702         else
 703                 printf("* Unmerged path %s\n", name);
 704 }
 705
 706 static void diff_fill_sha1_info(struct diff_filespec *one)
 707 {
 708         if (DIFF_FILE_VALID(one)) {
 709                 if (!one->sha1_valid) {
 710                         struct stat st;
 711                         if (lstat(one->path, &st) < 0)
 712                                 die("stat %s", one->path);
 713                         if (index_path(one->sha1, one->path, &st, 0))
 714                                 die("cannot hash %s\n", one->path);
 715                 }
 716         }
 717         else
 718                 memset(one->sha1, 0, 20);
 719 }
 720
 721 static void run_diff(struct diff_filepair *p, struct diff_options *o)
 722 {
 723         const char *pgm = external_diff();
 724         char msg[PATH_MAX*2+300], *xfrm_msg;
 725         struct diff_filespec *one;
 726         struct diff_filespec *two;
 727         const char *name;
 728         const char *other;
 729         char *name_munged, *other_munged;
 730         int complete_rewrite = 0;
 731         int len;
 732
 733         if (DIFF_PAIR_UNMERGED(p)) {
 734                 /* unmerged */
 735                 run_diff_cmd(pgm, p->one->path, NULL, NULL, NULL, NULL, 0);
 736                 return;
 737         }
 738
 739         name = p->one->path;
 740         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
 741         name_munged = quote_one(name);
 742         other_munged = quote_one(other);
 743         one = p->one; two = p->two;
 744
 745         diff_fill_sha1_info(one);
 746         diff_fill_sha1_info(two);
 747
 748         len = 0;
 749         switch (p->status) {
 750         case DIFF_STATUS_COPIED:
 751                 len += snprintf(msg + len, sizeof(msg) - len,
 752                                 "similarity index %d%%\n"
 753                                 "copy from %s\n"
 754                                 "copy to %s\n",
 755                                 (int)(0.5 + p->score * 100.0/MAX_SCORE),
 756                                 name_munged, other_munged);
 757                 break;
 758         case DIFF_STATUS_RENAMED:
 759                 len += snprintf(msg + len, sizeof(msg) - len,
 760                                 "similarity index %d%%\n"
 761                                 "rename from %s\n"
 762                                 "rename to %s\n",
 763                                 (int)(0.5 + p->score * 100.0/MAX_SCORE),
 764                                 name_munged, other_munged);
 765                 break;
 766         case DIFF_STATUS_MODIFIED:
 767                 if (p->score) {
 768                         len += snprintf(msg + len, sizeof(msg) - len,
 769                                         "dissimilarity index %d%%\n",
 770                                         (int)(0.5 + p->score *
 771                                               100.0/MAX_SCORE));
 772                         complete_rewrite = 1;
 773                         break;
 774                 }
 775                 /* fallthru */
 776         default:
 777                 /* nothing */
 778                 ;
 779         }
 780
 781         if (memcmp(one->sha1, two->sha1, 20)) {
 782                 char one_sha1[41];
 783                 int abbrev = o->full_index ? 40 : DEFAULT_ABBREV;
 784                 memcpy(one_sha1, sha1_to_hex(one->sha1), 41);
 785
 786                 len += snprintf(msg + len, sizeof(msg) - len,
 787                                 "index %.*s..%.*s",
 788                                 abbrev, one_sha1, abbrev,
 789                                 sha1_to_hex(two->sha1));
 790                 if (one->mode == two->mode)
 791                         len += snprintf(msg + len, sizeof(msg) - len,
 792                                         " %06o", one->mode);
 793                 len += snprintf(msg + len, sizeof(msg) - len, "\n");
 794         }
 795
 796         if (len)
 797                 msg[--len] = 0;
 798         xfrm_msg = len ? msg : NULL;
 799
 800         if (!pgm &&
 801             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
 802             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
 803                 /* a filepair that changes between file and symlink
 804                  * needs to be split into deletion and creation.
 805                  */
 806                 struct diff_filespec *null = alloc_filespec(two->path);
 807                 run_diff_cmd(NULL, name, other, one, null, xfrm_msg, 0);
 808                 free(null);
 809                 null = alloc_filespec(one->path);
 810                 run_diff_cmd(NULL, name, other, null, two, xfrm_msg, 0);
 811                 free(null);
 812         }
 813         else
 814                 run_diff_cmd(pgm, name, other, one, two, xfrm_msg,
 815                              complete_rewrite);
 816
 817         free(name_munged);
 818         free(other_munged);
 819 }
 820
 821 void diff_setup(struct diff_options *options)
 822 {
 823         memset(options, 0, sizeof(*options));
 824         options->output_format = DIFF_FORMAT_RAW;
 825         options->line_termination = '\n';
 826         options->break_opt = -1;
 827         options->rename_limit = -1;
 828
 829         options->change = diff_change;
 830         options->add_remove = diff_addremove;
 831 }
 832
 833 int diff_setup_done(struct diff_options *options)
 834 {
 835         if ((options->find_copies_harder &&
 836              options->detect_rename != DIFF_DETECT_COPY) ||
 837             (0 <= options->rename_limit && !options->detect_rename))
 838                 return -1;
 839         if (options->detect_rename && options->rename_limit < 0)
 840                 options->rename_limit = diff_rename_limit_default;
 841         if (options->setup & DIFF_SETUP_USE_CACHE) {
 842                 if (!active_cache)
 843                         /* read-cache does not die even when it fails
 844                          * so it is safe for us to do this here.  Also
 845                          * it does not smudge active_cache or active_nr
 846                          * when it fails, so we do not have to worry about
 847                          * cleaning it up ourselves either.
 848                          */
 849                         read_cache();
 850         }
 851         if (options->setup & DIFF_SETUP_USE_SIZE_CACHE)
 852                 use_size_cache = 1;
 853         if (options->abbrev <= 0 || 40 < options->abbrev)
 854                 options->abbrev = 40; /* full */
 855
 856         return 0;
 857 }
 858
 859 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 860 {
 861         const char *arg = av[0];
 862         if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
 863                 options->output_format = DIFF_FORMAT_PATCH;
 864         else if (!strcmp(arg, "-z"))
 865                 options->line_termination = 0;
 866         else if (!strncmp(arg, "-l", 2))
 867                 options->rename_limit = strtoul(arg+2, NULL, 10);
 868         else if (!strcmp(arg, "--full-index"))
 869                 options->full_index = 1;
 870         else if (!strcmp(arg, "--name-only"))
 871                 options->output_format = DIFF_FORMAT_NAME;
 872         else if (!strcmp(arg, "--name-status"))
 873                 options->output_format = DIFF_FORMAT_NAME_STATUS;
 874         else if (!strcmp(arg, "-R"))
 875                 options->reverse_diff = 1;
 876         else if (!strncmp(arg, "-S", 2))
 877                 options->pickaxe = arg + 2;
 878         else if (!strcmp(arg, "-s"))
 879                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
 880         else if (!strncmp(arg, "-O", 2))
 881                 options->orderfile = arg + 2;
 882         else if (!strncmp(arg, "--diff-filter=", 14))
 883                 options->filter = arg + 14;
 884         else if (!strcmp(arg, "--pickaxe-all"))
 885                 options->pickaxe_opts = DIFF_PICKAXE_ALL;
 886         else if (!strncmp(arg, "-B", 2)) {
 887                 if ((options->break_opt =
 888                      diff_scoreopt_parse(arg)) == -1)
 889                         return -1;
 890         }
 891         else if (!strncmp(arg, "-M", 2)) {
 892                 if ((options->rename_score =
 893                      diff_scoreopt_parse(arg)) == -1)
 894                         return -1;
 895                 options->detect_rename = DIFF_DETECT_RENAME;
 896         }
 897         else if (!strncmp(arg, "-C", 2)) {
 898                 if ((options->rename_score =
 899                      diff_scoreopt_parse(arg)) == -1)
 900                         return -1;
 901                 options->detect_rename = DIFF_DETECT_COPY;
 902         }
 903         else if (!strcmp(arg, "--find-copies-harder"))
 904                 options->find_copies_harder = 1;
 905         else if (!strcmp(arg, "--abbrev"))
 906                 options->abbrev = DEFAULT_ABBREV;
 907         else if (!strncmp(arg, "--abbrev=", 9)) {
 908                 options->abbrev = strtoul(arg + 9, NULL, 10);
 909                 if (options->abbrev < MINIMUM_ABBREV)
 910                         options->abbrev = MINIMUM_ABBREV;
 911                 else if (40 < options->abbrev)
 912                         options->abbrev = 40;
 913         }
 914         else
 915                 return 0;
 916         return 1;
 917 }
 918
 919 static int parse_num(const char **cp_p)
 920 {
 921         unsigned long num, scale;
 922         int ch, dot;
 923         const char *cp = *cp_p;
 924
 925         num = 0;
 926         scale = 1;
 927         dot = 0;
 928         for(;;) {
 929                 ch = *cp;
 930                 if ( !dot && ch == '.' ) {
 931                         scale = 1;
 932                         dot = 1;
 933                 } else if ( ch == '%' ) {
 934                         scale = dot ? scale*100 : 100;
 935                         cp++;   /* % is always at the end */
 936                         break;
 937                 } else if ( ch >= '0' && ch <= '9' ) {
 938                         if ( scale < 100000 ) {
 939                                 scale *= 10;
 940                                 num = (num*10) + (ch-'0');
 941                         }
 942                 } else {
 943                         break;
 944                 }
 945                 cp++;
 946         }
 947         *cp_p = cp;
 948
 949         /* user says num divided by scale and we say internally that
 950          * is MAX_SCORE * num / scale.
 951          */
 952         return (num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale);
 953 }
 954
 955 int diff_scoreopt_parse(const char *opt)
 956 {
 957         int opt1, opt2, cmd;
 958
 959         if (*opt++ != '-')
 960                 return -1;
 961         cmd = *opt++;
 962         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
 963                 return -1; /* that is not a -M, -C nor -B option */
 964
 965         opt1 = parse_num(&opt);
 966         if (cmd != 'B')
 967                 opt2 = 0;
 968         else {
 969                 if (*opt == 0)
 970                         opt2 = 0;
 971                 else if (*opt != '/')
 972                         return -1; /* we expect -B80/99 or -B80 */
 973                 else {
 974                         opt++;
 975                         opt2 = parse_num(&opt);
 976                 }
 977         }
 978         if (*opt != 0)
 979                 return -1;
 980         return opt1 | (opt2 << 16);
 981 }
 982
 983 struct diff_queue_struct diff_queued_diff;
 984
 985 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
 986 {
 987         if (queue->alloc <= queue->nr) {
 988                 queue->alloc = alloc_nr(queue->alloc);
 989                 queue->queue = xrealloc(queue->queue,
 990                                         sizeof(dp) * queue->alloc);
 991         }
 992         queue->queue[queue->nr++] = dp;
 993 }
 994
 995 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
 996                                  struct diff_filespec *one,
 997                                  struct diff_filespec *two)
 998 {
 999         struct diff_filepair *dp = xmalloc(sizeof(*dp));
1000         dp->one = one;
1001         dp->two = two;
1002         dp->score = 0;
1003         dp->status = 0;
1004         dp->source_stays = 0;
1005         dp->broken_pair = 0;
1006         if (queue)
1007                 diff_q(queue, dp);
1008         return dp;
1009 }
1010
1011 void diff_free_filepair(struct diff_filepair *p)
1012 {
1013         diff_free_filespec_data(p->one);
1014         diff_free_filespec_data(p->two);
1015         free(p->one);
1016         free(p->two);
1017         free(p);
1018 }
1019
1020 /* This is different from find_unique_abbrev() in that
1021  * it stuffs the result with dots for alignment.
1022  */
1023 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
1024 {
1025         int abblen;
1026         const char *abbrev;
1027         if (len == 40)
1028                 return sha1_to_hex(sha1);
1029
1030         abbrev = find_unique_abbrev(sha1, len);
1031         if (!abbrev)
1032                 return sha1_to_hex(sha1);
1033         abblen = strlen(abbrev);
1034         if (abblen < 37) {
1035                 static char hex[41];
1036                 if (len < abblen && abblen <= len + 2)
1037                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
1038                 else
1039                         sprintf(hex, "%s...", abbrev);
1040                 return hex;
1041         }
1042         return sha1_to_hex(sha1);
1043 }
1044
1045 static void diff_flush_raw(struct diff_filepair *p,
1046                            int line_termination,
1047                            int inter_name_termination,
1048                            struct diff_options *options)
1049 {
1050         int two_paths;
1051         char status[10];
1052         int abbrev = options->abbrev;
1053         const char *path_one, *path_two;
1054         int output_format = options->output_format;
1055
1056         path_one = p->one->path;
1057         path_two = p->two->path;
1058         if (line_termination) {
1059                 path_one = quote_one(path_one);
1060                 path_two = quote_one(path_two);
1061         }
1062
1063         if (p->score)
1064                 sprintf(status, "%c%03d", p->status,
1065                         (int)(0.5 + p->score * 100.0/MAX_SCORE));
1066         else {
1067                 status[0] = p->status;
1068                 status[1] = 0;
1069         }
1070         switch (p->status) {
1071         case DIFF_STATUS_COPIED:
1072         case DIFF_STATUS_RENAMED:
1073                 two_paths = 1;
1074                 break;
1075         case DIFF_STATUS_ADDED:
1076         case DIFF_STATUS_DELETED:
1077                 two_paths = 0;
1078                 break;
1079         default:
1080                 two_paths = 0;
1081                 break;
1082         }
1083         if (output_format != DIFF_FORMAT_NAME_STATUS) {
1084                 printf(":%06o %06o %s ",
1085                        p->one->mode, p->two->mode,
1086                        diff_unique_abbrev(p->one->sha1, abbrev));
1087                 printf("%s ",
1088                        diff_unique_abbrev(p->two->sha1, abbrev));
1089         }
1090         printf("%s%c%s", status, inter_name_termination, path_one);
1091         if (two_paths)
1092                 printf("%c%s", inter_name_termination, path_two);
1093         putchar(line_termination);
1094         if (path_one != p->one->path)
1095                 free((void*)path_one);
1096         if (path_two != p->two->path)
1097                 free((void*)path_two);
1098 }
1099
1100 static void diff_flush_name(struct diff_filepair *p,
1101                             int inter_name_termination,
1102                             int line_termination)
1103 {
1104         char *path = p->two->path;
1105
1106         if (line_termination)
1107                 path = quote_one(p->two->path);
1108         else
1109                 path = p->two->path;
1110         printf("%s%c", path, line_termination);
1111         if (p->two->path != path)
1112                 free(path);
1113 }
1114
1115 int diff_unmodified_pair(struct diff_filepair *p)
1116 {
1117         /* This function is written stricter than necessary to support
1118          * the currently implemented transformers, but the idea is to
1119          * let transformers to produce diff_filepairs any way they want,
1120          * and filter and clean them up here before producing the output.
1121          */
1122         struct diff_filespec *one, *two;
1123
1124         if (DIFF_PAIR_UNMERGED(p))
1125                 return 0; /* unmerged is interesting */
1126
1127         one = p->one;
1128         two = p->two;
1129
1130         /* deletion, addition, mode or type change
1131          * and rename are all interesting.
1132          */
1133         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
1134             DIFF_PAIR_MODE_CHANGED(p) ||
1135             strcmp(one->path, two->path))
1136                 return 0;
1137
1138         /* both are valid and point at the same path.  that is, we are
1139          * dealing with a change.
1140          */
1141         if (one->sha1_valid && two->sha1_valid &&
1142             !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
1143                 return 1; /* no change */
1144         if (!one->sha1_valid && !two->sha1_valid)
1145                 return 1; /* both look at the same file on the filesystem. */
1146         return 0;
1147 }
1148
1149 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
1150 {
1151         if (diff_unmodified_pair(p))
1152                 return;
1153
1154         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1155             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1156                 return; /* no tree diffs in patch format */
1157
1158         run_diff(p, o);
1159 }
1160
1161 int diff_queue_is_empty(void)
1162 {
1163         struct diff_queue_struct *q = &diff_queued_diff;
1164         int i;
1165         for (i = 0; i < q->nr; i++)
1166                 if (!diff_unmodified_pair(q->queue[i]))
1167                         return 0;
1168         return 1;
1169 }
1170
1171 #if DIFF_DEBUG
1172 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
1173 {
1174         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
1175                 x, one ? one : "",
1176                 s->path,
1177                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
1178                 s->mode,
1179                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
1180         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
1181                 x, one ? one : "",
1182                 s->size, s->xfrm_flags);
1183 }
1184
1185 void diff_debug_filepair(const struct diff_filepair *p, int i)
1186 {
1187         diff_debug_filespec(p->one, i, "one");
1188         diff_debug_filespec(p->two, i, "two");
1189         fprintf(stderr, "score %d, status %c stays %d broken %d\n",
1190                 p->score, p->status ? p->status : '?',
1191                 p->source_stays, p->broken_pair);
1192 }
1193
1194 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
1195 {
1196         int i;
1197         if (msg)
1198                 fprintf(stderr, "%s\n", msg);
1199         fprintf(stderr, "q->nr = %d\n", q->nr);
1200         for (i = 0; i < q->nr; i++) {
1201                 struct diff_filepair *p = q->queue[i];
1202                 diff_debug_filepair(p, i);
1203         }
1204 }
1205 #endif
1206
1207 static void diff_resolve_rename_copy(void)
1208 {
1209         int i, j;
1210         struct diff_filepair *p, *pp;
1211         struct diff_queue_struct *q = &diff_queued_diff;
1212
1213         diff_debug_queue("resolve-rename-copy", q);
1214
1215         for (i = 0; i < q->nr; i++) {
1216                 p = q->queue[i];
1217                 p->status = 0; /* undecided */
1218                 if (DIFF_PAIR_UNMERGED(p))
1219                         p->status = DIFF_STATUS_UNMERGED;
1220                 else if (!DIFF_FILE_VALID(p->one))
1221                         p->status = DIFF_STATUS_ADDED;
1222                 else if (!DIFF_FILE_VALID(p->two))
1223                         p->status = DIFF_STATUS_DELETED;
1224                 else if (DIFF_PAIR_TYPE_CHANGED(p))
1225                         p->status = DIFF_STATUS_TYPE_CHANGED;
1226
1227                 /* from this point on, we are dealing with a pair
1228                  * whose both sides are valid and of the same type, i.e.
1229                  * either in-place edit or rename/copy edit.
1230                  */
1231                 else if (DIFF_PAIR_RENAME(p)) {
1232                         if (p->source_stays) {
1233                                 p->status = DIFF_STATUS_COPIED;
1234                                 continue;
1235                         }
1236                         /* See if there is some other filepair that
1237                          * copies from the same source as us.  If so
1238                          * we are a copy.  Otherwise we are either a
1239                          * copy if the path stays, or a rename if it
1240                          * does not, but we already handled "stays" case.
1241                          */
1242                         for (j = i + 1; j < q->nr; j++) {
1243                                 pp = q->queue[j];
1244                                 if (strcmp(pp->one->path, p->one->path))
1245                                         continue; /* not us */
1246                                 if (!DIFF_PAIR_RENAME(pp))
1247                                         continue; /* not a rename/copy */
1248                                 /* pp is a rename/copy from the same source */
1249                                 p->status = DIFF_STATUS_COPIED;
1250                                 break;
1251                         }
1252                         if (!p->status)
1253                                 p->status = DIFF_STATUS_RENAMED;
1254                 }
1255                 else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
1256                          p->one->mode != p->two->mode)
1257                         p->status = DIFF_STATUS_MODIFIED;
1258                 else {
1259                         /* This is a "no-change" entry and should not
1260                          * happen anymore, but prepare for broken callers.
1261                          */
1262                         error("feeding unmodified %s to diffcore",
1263                               p->one->path);
1264                         p->status = DIFF_STATUS_UNKNOWN;
1265                 }
1266         }
1267         diff_debug_queue("resolve-rename-copy done", q);
1268 }
1269
1270 void diff_flush(struct diff_options *options)
1271 {
1272         struct diff_queue_struct *q = &diff_queued_diff;
1273         int i;
1274         int inter_name_termination = '\t';
1275         int diff_output_format = options->output_format;
1276         int line_termination = options->line_termination;
1277
1278         if (!line_termination)
1279                 inter_name_termination = 0;
1280
1281         for (i = 0; i < q->nr; i++) {
1282                 struct diff_filepair *p = q->queue[i];
1283                 if ((diff_output_format == DIFF_FORMAT_NO_OUTPUT) ||
1284                     (p->status == DIFF_STATUS_UNKNOWN))
1285                         continue;
1286                 if (p->status == 0)
1287                         die("internal error in diff-resolve-rename-copy");
1288                 switch (diff_output_format) {
1289                 case DIFF_FORMAT_PATCH:
1290                         diff_flush_patch(p, options);
1291                         break;
1292                 case DIFF_FORMAT_RAW:
1293                 case DIFF_FORMAT_NAME_STATUS:
1294                         diff_flush_raw(p, line_termination,
1295                                        inter_name_termination,
1296                                        options);
1297                         break;
1298                 case DIFF_FORMAT_NAME:
1299                         diff_flush_name(p,
1300                                         inter_name_termination,
1301                                         line_termination);
1302                         break;
1303                 }
1304                 diff_free_filepair(q->queue[i]);
1305         }
1306         free(q->queue);
1307         q->queue = NULL;
1308         q->nr = q->alloc = 0;
1309 }
1310
1311 static void diffcore_apply_filter(const char *filter)
1312 {
1313         int i;
1314         struct diff_queue_struct *q = &diff_queued_diff;
1315         struct diff_queue_struct outq;
1316         outq.queue = NULL;
1317         outq.nr = outq.alloc = 0;
1318
1319         if (!filter)
1320                 return;
1321
1322         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
1323                 int found;
1324                 for (i = found = 0; !found && i < q->nr; i++) {
1325                         struct diff_filepair *p = q->queue[i];
1326                         if (((p->status == DIFF_STATUS_MODIFIED) &&
1327                              ((p->score &&
1328                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1329                               (!p->score &&
1330                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1331                             ((p->status != DIFF_STATUS_MODIFIED) &&
1332                              strchr(filter, p->status)))
1333                                 found++;
1334                 }
1335                 if (found)
1336                         return;
1337
1338                 /* otherwise we will clear the whole queue
1339                  * by copying the empty outq at the end of this
1340                  * function, but first clear the current entries
1341                  * in the queue.
1342                  */
1343                 for (i = 0; i < q->nr; i++)
1344                         diff_free_filepair(q->queue[i]);
1345         }
1346         else {
1347                 /* Only the matching ones */
1348                 for (i = 0; i < q->nr; i++) {
1349                         struct diff_filepair *p = q->queue[i];
1350
1351                         if (((p->status == DIFF_STATUS_MODIFIED) &&
1352                              ((p->score &&
1353                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1354                               (!p->score &&
1355                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1356                             ((p->status != DIFF_STATUS_MODIFIED) &&
1357                              strchr(filter, p->status)))
1358                                 diff_q(&outq, p);
1359                         else
1360                                 diff_free_filepair(p);
1361                 }
1362         }
1363         free(q->queue);
1364         *q = outq;
1365 }
1366
1367 void diffcore_std(struct diff_options *options)
1368 {
1369         if (options->paths && options->paths[0])
1370                 diffcore_pathspec(options->paths);
1371         if (options->break_opt != -1)
1372                 diffcore_break(options->break_opt);
1373         if (options->detect_rename)
1374                 diffcore_rename(options);
1375         if (options->break_opt != -1)
1376                 diffcore_merge_broken();
1377         if (options->pickaxe)
1378                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
1379         if (options->orderfile)
1380                 diffcore_order(options->orderfile);
1381         diff_resolve_rename_copy();
1382         diffcore_apply_filter(options->filter);
1383 }
1384
1385
1386 void diffcore_std_no_resolve(struct diff_options *options)
1387 {
1388         if (options->pickaxe)
1389                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
1390         if (options->orderfile)
1391                 diffcore_order(options->orderfile);
1392         diffcore_apply_filter(options->filter);
1393 }
1394
1395 void diff_addremove(struct diff_options *options,
1396                     int addremove, unsigned mode,
1397                     const unsigned char *sha1,
1398                     const char *base, const char *path)
1399 {
1400         char concatpath[PATH_MAX];
1401         struct diff_filespec *one, *two;
1402
1403         /* This may look odd, but it is a preparation for
1404          * feeding "there are unchanged files which should
1405          * not produce diffs, but when you are doing copy
1406          * detection you would need them, so here they are"
1407          * entries to the diff-core.  They will be prefixed
1408          * with something like '=' or '*' (I haven't decided
1409          * which but should not make any difference).
1410          * Feeding the same new and old to diff_change()
1411          * also has the same effect.
1412          * Before the final output happens, they are pruned after
1413          * merged into rename/copy pairs as appropriate.
1414          */
1415         if (options->reverse_diff)
1416                 addremove = (addremove == '+' ? '-' :
1417                              addremove == '-' ? '+' : addremove);
1418
1419         if (!path) path = "";
1420         sprintf(concatpath, "%s%s", base, path);
1421         one = alloc_filespec(concatpath);
1422         two = alloc_filespec(concatpath);
1423
1424         if (addremove != '+')
1425                 fill_filespec(one, sha1, mode);
1426         if (addremove != '-')
1427                 fill_filespec(two, sha1, mode);
1428
1429         diff_queue(&diff_queued_diff, one, two);
1430 }
1431
1432 void diff_change(struct diff_options *options,
1433                  unsigned old_mode, unsigned new_mode,
1434                  const unsigned char *old_sha1,
1435                  const unsigned char *new_sha1,
1436                  const char *base, const char *path)
1437 {
1438         char concatpath[PATH_MAX];
1439         struct diff_filespec *one, *two;
1440
1441         if (options->reverse_diff) {
1442                 unsigned tmp;
1443                 const unsigned char *tmp_c;
1444                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
1445                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
1446         }
1447         if (!path) path = "";
1448         sprintf(concatpath, "%s%s", base, path);
1449         one = alloc_filespec(concatpath);
1450         two = alloc_filespec(concatpath);
1451         fill_filespec(one, old_sha1, old_mode);
1452         fill_filespec(two, new_sha1, new_mode);
1453
1454         diff_queue(&diff_queued_diff, one, two);
1455 }
1456
1457 void diff_unmerge(struct diff_options *options,
1458                   const char *path)
1459 {
1460         struct diff_filespec *one, *two;
1461         one = alloc_filespec(path);
1462         two = alloc_filespec(path);
1463         diff_queue(&diff_queued_diff, one, two);
1464 }