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         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
 164 static 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
 178 struct emit_callback {
 179         const char **label_path;
 180 };
 181
 182 static 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
 198 #define FIRST_FEW_BYTES 8000
 199 static int mmfile_is_binary(mmfile_t *mf)
 200 {
 201         long sz = mf->size;
 202         if (FIRST_FEW_BYTES < sz)
 203                 sz = FIRST_FEW_BYTES;
 204         if (memchr(mf->ptr, 0, sz))
 205                 return 1;
 206         return 0;
 207 }
 208
 209 static void builtin_diff(const char *name_a,
 210                          const char *name_b,
 211                          struct diff_filespec *one,
 212                          struct diff_filespec *two,
 213                          const char *xfrm_msg,
 214                          int complete_rewrite)
 215 {
 216         mmfile_t mf1, mf2;
 217         const char *lbl[2];
 218         char *a_one, *b_two;
 219
 220         a_one = quote_two("a/", name_a);
 221         b_two = quote_two("b/", name_b);
 222         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
 223         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
 224         printf("diff --git %s %s\n", a_one, b_two);
 225         if (lbl[0][0] == '/') {
 226                 /* /dev/null */
 227                 printf("new file mode %06o\n", two->mode);
 228                 if (xfrm_msg && xfrm_msg[0])
 229                         puts(xfrm_msg);
 230         }
 231         else if (lbl[1][0] == '/') {
 232                 printf("deleted file mode %06o\n", one->mode);
 233                 if (xfrm_msg && xfrm_msg[0])
 234                         puts(xfrm_msg);
 235         }
 236         else {
 237                 if (one->mode != two->mode) {
 238                         printf("old mode %06o\n", one->mode);
 239                         printf("new mode %06o\n", two->mode);
 240                 }
 241                 if (xfrm_msg && xfrm_msg[0])
 242                         puts(xfrm_msg);
 243                 /*
 244                  * we do not run diff between different kind
 245                  * of objects.
 246                  */
 247                 if ((one->mode ^ two->mode) & S_IFMT)
 248                         goto free_ab_and_return;
 249                 if (complete_rewrite) {
 250                         emit_rewrite_diff(name_a, name_b, one, two);
 251                         goto free_ab_and_return;
 252                 }
 253         }
 254
 255         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
 256                 die("unable to read files to diff");
 257
 258         if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))
 259                 printf("Binary files %s and %s differ\n", lbl[0], lbl[1]);
 260         else {
 261                 /* Crazy xdl interfaces.. */
 262                 const char *diffopts = getenv("GIT_DIFF_OPTS");
 263                 xpparam_t xpp;
 264                 xdemitconf_t xecfg;
 265                 xdemitcb_t ecb;
 266                 struct emit_callback ecbdata;
 267
 268                 ecbdata.label_path = lbl;
 269                 xpp.flags = XDF_NEED_MINIMAL;
 270                 xecfg.ctxlen = 3;
 271                 xecfg.flags = XDL_EMIT_FUNCNAMES;
 272                 if (!diffopts)
 273                         ;
 274                 else if (!strncmp(diffopts, "--unified=", 10))
 275                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
 276                 else if (!strncmp(diffopts, "-u", 2))
 277                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
 278                 ecb.outf = fn_out;
 279                 ecb.priv = &ecbdata;
 280                 xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
 281         }
 282
 283  free_ab_and_return:
 284         free(a_one);
 285         free(b_two);
 286         return;
 287 }
 288
 289 struct diff_filespec *alloc_filespec(const char *path)
 290 {
 291         int namelen = strlen(path);
 292         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
 293
 294         memset(spec, 0, sizeof(*spec));
 295         spec->path = (char *)(spec + 1);
 296         memcpy(spec->path, path, namelen+1);
 297         return spec;
 298 }
 299
 300 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
 301                    unsigned short mode)
 302 {
 303         if (mode) {
 304                 spec->mode = canon_mode(mode);
 305                 memcpy(spec->sha1, sha1, 20);
 306                 spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
 307         }
 308 }
 309
 310 /*
 311  * Given a name and sha1 pair, if the dircache tells us the file in
 312  * the work tree has that object contents, return true, so that
 313  * prepare_temp_file() does not have to inflate and extract.
 314  */
 315 static int work_tree_matches(const char *name, const unsigned char *sha1)
 316 {
 317         struct cache_entry *ce;
 318         struct stat st;
 319         int pos, len;
 320
 321         /* We do not read the cache ourselves here, because the
 322          * benchmark with my previous version that always reads cache
 323          * shows that it makes things worse for diff-tree comparing
 324          * two linux-2.6 kernel trees in an already checked out work
 325          * tree.  This is because most diff-tree comparisons deal with
 326          * only a small number of files, while reading the cache is
 327          * expensive for a large project, and its cost outweighs the
 328          * savings we get by not inflating the object to a temporary
 329          * file.  Practically, this code only helps when we are used
 330          * by diff-cache --cached, which does read the cache before
 331          * calling us.
 332          */
 333         if (!active_cache)
 334                 return 0;
 335
 336         len = strlen(name);
 337         pos = cache_name_pos(name, len);
 338         if (pos < 0)
 339                 return 0;
 340         ce = active_cache[pos];
 341         if ((lstat(name, &st) < 0) ||
 342             !S_ISREG(st.st_mode) || /* careful! */
 343             ce_match_stat(ce, &st, 0) ||
 344             memcmp(sha1, ce->sha1, 20))
 345                 return 0;
 346         /* we return 1 only when we can stat, it is a regular file,
 347          * stat information matches, and sha1 recorded in the cache
 348          * matches.  I.e. we know the file in the work tree really is
 349          * the same as the <name, sha1> pair.
 350          */
 351         return 1;
 352 }
 353
 354 static struct sha1_size_cache {
 355         unsigned char sha1[20];
 356         unsigned long size;
 357 } **sha1_size_cache;
 358 static int sha1_size_cache_nr, sha1_size_cache_alloc;
 359
 360 static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
 361                                                  int find_only,
 362                                                  unsigned long size)
 363 {
 364         int first, last;
 365         struct sha1_size_cache *e;
 366
 367         first = 0;
 368         last = sha1_size_cache_nr;
 369         while (last > first) {
 370                 int cmp, next = (last + first) >> 1;
 371                 e = sha1_size_cache[next];
 372                 cmp = memcmp(e->sha1, sha1, 20);
 373                 if (!cmp)
 374                         return e;
 375                 if (cmp < 0) {
 376                         last = next;
 377                         continue;
 378                 }
 379                 first = next+1;
 380         }
 381         /* not found */
 382         if (find_only)
 383                 return NULL;
 384         /* insert to make it at "first" */
 385         if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
 386                 sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
 387                 sha1_size_cache = xrealloc(sha1_size_cache,
 388                                            sha1_size_cache_alloc *
 389                                            sizeof(*sha1_size_cache));
 390         }
 391         sha1_size_cache_nr++;
 392         if (first < sha1_size_cache_nr)
 393                 memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
 394                         (sha1_size_cache_nr - first - 1) *
 395                         sizeof(*sha1_size_cache));
 396         e = xmalloc(sizeof(struct sha1_size_cache));
 397         sha1_size_cache[first] = e;
 398         memcpy(e->sha1, sha1, 20);
 399         e->size = size;
 400         return e;
 401 }
 402
 403 /*
 404  * While doing rename detection and pickaxe operation, we may need to
 405  * grab the data for the blob (or file) for our own in-core comparison.
 406  * diff_filespec has data and size fields for this purpose.
 407  */
 408 int diff_populate_filespec(struct diff_filespec *s, int size_only)
 409 {
 410         int err = 0;
 411         if (!DIFF_FILE_VALID(s))
 412                 die("internal error: asking to populate invalid file.");
 413         if (S_ISDIR(s->mode))
 414                 return -1;
 415
 416         if (!use_size_cache)
 417                 size_only = 0;
 418
 419         if (s->data)
 420                 return err;
 421         if (!s->sha1_valid ||
 422             work_tree_matches(s->path, s->sha1)) {
 423                 struct stat st;
 424                 int fd;
 425                 if (lstat(s->path, &st) < 0) {
 426                         if (errno == ENOENT) {
 427                         err_empty:
 428                                 err = -1;
 429                         empty:
 430                                 s->data = "";
 431                                 s->size = 0;
 432                                 return err;
 433                         }
 434                 }
 435                 s->size = st.st_size;
 436                 if (!s->size)
 437                         goto empty;
 438                 if (size_only)
 439                         return 0;
 440                 if (S_ISLNK(st.st_mode)) {
 441                         int ret;
 442                         s->data = xmalloc(s->size);
 443                         s->should_free = 1;
 444                         ret = readlink(s->path, s->data, s->size);
 445                         if (ret < 0) {
 446                                 free(s->data);
 447                                 goto err_empty;
 448                         }
 449                         return 0;
 450                 }
 451                 fd = open(s->path, O_RDONLY);
 452                 if (fd < 0)
 453                         goto err_empty;
 454                 s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
 455                 close(fd);
 456                 if (s->data == MAP_FAILED)
 457                         goto err_empty;
 458                 s->should_munmap = 1;
 459         }
 460         else {
 461                 char type[20];
 462                 struct sha1_size_cache *e;
 463
 464                 if (size_only) {
 465                         e = locate_size_cache(s->sha1, 1, 0);
 466                         if (e) {
 467                                 s->size = e->size;
 468                                 return 0;
 469                         }
 470                         if (!sha1_object_info(s->sha1, type, &s->size))
 471                                 locate_size_cache(s->sha1, 0, s->size);
 472                 }
 473                 else {
 474                         s->data = read_sha1_file(s->sha1, type, &s->size);
 475                         s->should_free = 1;
 476                 }
 477         }
 478         return 0;
 479 }
 480
 481 void diff_free_filespec_data(struct diff_filespec *s)
 482 {
 483         if (s->should_free)
 484                 free(s->data);
 485         else if (s->should_munmap)
 486                 munmap(s->data, s->size);
 487         s->should_free = s->should_munmap = 0;
 488         s->data = NULL;
 489         free(s->cnt_data);
 490         s->cnt_data = NULL;
 491 }
 492
 493 static void prep_temp_blob(struct diff_tempfile *temp,
 494                            void *blob,
 495                            unsigned long size,
 496                            const unsigned char *sha1,
 497                            int mode)
 498 {
 499         int fd;
 500
 501         fd = git_mkstemp(temp->tmp_path, TEMPFILE_PATH_LEN, ".diff_XXXXXX");
 502         if (fd < 0)
 503                 die("unable to create temp-file");
 504         if (write(fd, blob, size) != size)
 505                 die("unable to write temp-file");
 506         close(fd);
 507         temp->name = temp->tmp_path;
 508         strcpy(temp->hex, sha1_to_hex(sha1));
 509         temp->hex[40] = 0;
 510         sprintf(temp->mode, "%06o", mode);
 511 }
 512
 513 static void prepare_temp_file(const char *name,
 514                               struct diff_tempfile *temp,
 515                               struct diff_filespec *one)
 516 {
 517         if (!DIFF_FILE_VALID(one)) {
 518         not_a_valid_file:
 519                 /* A '-' entry produces this for file-2, and
 520                  * a '+' entry produces this for file-1.
 521                  */
 522                 temp->name = "/dev/null";
 523                 strcpy(temp->hex, ".");
 524                 strcpy(temp->mode, ".");
 525                 return;
 526         }
 527
 528         if (!one->sha1_valid ||
 529             work_tree_matches(name, one->sha1)) {
 530                 struct stat st;
 531                 if (lstat(name, &st) < 0) {
 532                         if (errno == ENOENT)
 533                                 goto not_a_valid_file;
 534                         die("stat(%s): %s", name, strerror(errno));
 535                 }
 536                 if (S_ISLNK(st.st_mode)) {
 537                         int ret;
 538                         char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
 539                         if (sizeof(buf) <= st.st_size)
 540                                 die("symlink too long: %s", name);
 541                         ret = readlink(name, buf, st.st_size);
 542                         if (ret < 0)
 543                                 die("readlink(%s)", name);
 544                         prep_temp_blob(temp, buf, st.st_size,
 545                                        (one->sha1_valid ?
 546                                         one->sha1 : null_sha1),
 547                                        (one->sha1_valid ?
 548                                         one->mode : S_IFLNK));
 549                 }
 550                 else {
 551                         /* we can borrow from the file in the work tree */
 552                         temp->name = name;
 553                         if (!one->sha1_valid)
 554                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
 555                         else
 556                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
 557                         /* Even though we may sometimes borrow the
 558                          * contents from the work tree, we always want
 559                          * one->mode.  mode is trustworthy even when
 560                          * !(one->sha1_valid), as long as
 561                          * DIFF_FILE_VALID(one).
 562                          */
 563                         sprintf(temp->mode, "%06o", one->mode);
 564                 }
 565                 return;
 566         }
 567         else {
 568                 if (diff_populate_filespec(one, 0))
 569                         die("cannot read data blob for %s", one->path);
 570                 prep_temp_blob(temp, one->data, one->size,
 571                                one->sha1, one->mode);
 572         }
 573 }
 574
 575 static void remove_tempfile(void)
 576 {
 577         int i;
 578
 579         for (i = 0; i < 2; i++)
 580                 if (diff_temp[i].name == diff_temp[i].tmp_path) {
 581                         unlink(diff_temp[i].name);
 582                         diff_temp[i].name = NULL;
 583                 }
 584 }
 585
 586 static void remove_tempfile_on_signal(int signo)
 587 {
 588         remove_tempfile();
 589         signal(SIGINT, SIG_DFL);
 590         raise(signo);
 591 }
 592
 593 static int spawn_prog(const char *pgm, const char **arg)
 594 {
 595         pid_t pid;
 596         int status;
 597
 598         fflush(NULL);
 599         pid = fork();
 600         if (pid < 0)
 601                 die("unable to fork");
 602         if (!pid) {
 603                 execvp(pgm, (char *const*) arg);
 604                 exit(255);
 605         }
 606
 607         while (waitpid(pid, &status, 0) < 0) {
 608                 if (errno == EINTR)
 609                         continue;
 610                 return -1;
 611         }
 612
 613         /* Earlier we did not check the exit status because
 614          * diff exits non-zero if files are different, and
 615          * we are not interested in knowing that.  It was a
 616          * mistake which made it harder to quit a diff-*
 617          * session that uses the git-apply-patch-script as
 618          * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
 619          * should also exit non-zero only when it wants to
 620          * abort the entire diff-* session.
 621          */
 622         if (WIFEXITED(status) && !WEXITSTATUS(status))
 623                 return 0;
 624         return -1;
 625 }
 626
 627 /* An external diff command takes:
 628  *
 629  * diff-cmd name infile1 infile1-sha1 infile1-mode \
 630  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
 631  *
 632  */
 633 static void run_external_diff(const char *pgm,
 634                               const char *name,
 635                               const char *other,
 636                               struct diff_filespec *one,
 637                               struct diff_filespec *two,
 638                               const char *xfrm_msg,
 639                               int complete_rewrite)
 640 {
 641         const char *spawn_arg[10];
 642         struct diff_tempfile *temp = diff_temp;
 643         int retval;
 644         static int atexit_asked = 0;
 645         const char *othername;
 646         const char **arg = &spawn_arg[0];
 647
 648         othername = (other? other : name);
 649         if (one && two) {
 650                 prepare_temp_file(name, &temp[0], one);
 651                 prepare_temp_file(othername, &temp[1], two);
 652                 if (! atexit_asked &&
 653                     (temp[0].name == temp[0].tmp_path ||
 654                      temp[1].name == temp[1].tmp_path)) {
 655                         atexit_asked = 1;
 656                         atexit(remove_tempfile);
 657                 }
 658                 signal(SIGINT, remove_tempfile_on_signal);
 659         }
 660
 661         if (one && two) {
 662                 *arg++ = pgm;
 663                 *arg++ = name;
 664                 *arg++ = temp[0].name;
 665                 *arg++ = temp[0].hex;
 666                 *arg++ = temp[0].mode;
 667                 *arg++ = temp[1].name;
 668                 *arg++ = temp[1].hex;
 669                 *arg++ = temp[1].mode;
 670                 if (other) {
 671                         *arg++ = other;
 672                         *arg++ = xfrm_msg;
 673                 }
 674         } else {
 675                 *arg++ = pgm;
 676                 *arg++ = name;
 677         }
 678         *arg = NULL;
 679         retval = spawn_prog(pgm, spawn_arg);
 680         remove_tempfile();
 681         if (retval) {
 682                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
 683                 exit(1);
 684         }
 685 }
 686
 687 static void run_diff_cmd(const char *pgm,
 688                          const char *name,
 689                          const char *other,
 690                          struct diff_filespec *one,
 691                          struct diff_filespec *two,
 692                          const char *xfrm_msg,
 693                          int complete_rewrite)
 694 {
 695         if (pgm) {
 696                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
 697                                   complete_rewrite);
 698                 return;
 699         }
 700         if (one && two)
 701                 builtin_diff(name, other ? other : name,
 702                              one, two, xfrm_msg, complete_rewrite);
 703         else
 704                 printf("* Unmerged path %s\n", name);
 705 }
 706
 707 static void diff_fill_sha1_info(struct diff_filespec *one)
 708 {
 709         if (DIFF_FILE_VALID(one)) {
 710                 if (!one->sha1_valid) {
 711                         struct stat st;
 712                         if (lstat(one->path, &st) < 0)
 713                                 die("stat %s", one->path);
 714                         if (index_path(one->sha1, one->path, &st, 0))
 715                                 die("cannot hash %s\n", one->path);
 716                 }
 717         }
 718         else
 719                 memset(one->sha1, 0, 20);
 720 }
 721
 722 static void run_diff(struct diff_filepair *p, struct diff_options *o)
 723 {
 724         const char *pgm = external_diff();
 725         char msg[PATH_MAX*2+300], *xfrm_msg;
 726         struct diff_filespec *one;
 727         struct diff_filespec *two;
 728         const char *name;
 729         const char *other;
 730         char *name_munged, *other_munged;
 731         int complete_rewrite = 0;
 732         int len;
 733
 734         if (DIFF_PAIR_UNMERGED(p)) {
 735                 /* unmerged */
 736                 run_diff_cmd(pgm, p->one->path, NULL, NULL, NULL, NULL, 0);
 737                 return;
 738         }
 739
 740         name = p->one->path;
 741         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
 742         name_munged = quote_one(name);
 743         other_munged = quote_one(other);
 744         one = p->one; two = p->two;
 745
 746         diff_fill_sha1_info(one);
 747         diff_fill_sha1_info(two);
 748
 749         len = 0;
 750         switch (p->status) {
 751         case DIFF_STATUS_COPIED:
 752                 len += snprintf(msg + len, sizeof(msg) - len,
 753                                 "similarity index %d%%\n"
 754                                 "copy from %s\n"
 755                                 "copy to %s\n",
 756                                 (int)(0.5 + p->score * 100.0/MAX_SCORE),
 757                                 name_munged, other_munged);
 758                 break;
 759         case DIFF_STATUS_RENAMED:
 760                 len += snprintf(msg + len, sizeof(msg) - len,
 761                                 "similarity index %d%%\n"
 762                                 "rename from %s\n"
 763                                 "rename to %s\n",
 764                                 (int)(0.5 + p->score * 100.0/MAX_SCORE),
 765                                 name_munged, other_munged);
 766                 break;
 767         case DIFF_STATUS_MODIFIED:
 768                 if (p->score) {
 769                         len += snprintf(msg + len, sizeof(msg) - len,
 770                                         "dissimilarity index %d%%\n",
 771                                         (int)(0.5 + p->score *
 772                                               100.0/MAX_SCORE));
 773                         complete_rewrite = 1;
 774                         break;
 775                 }
 776                 /* fallthru */
 777         default:
 778                 /* nothing */
 779                 ;
 780         }
 781
 782         if (memcmp(one->sha1, two->sha1, 20)) {
 783                 char one_sha1[41];
 784                 int abbrev = o->full_index ? 40 : DEFAULT_ABBREV;
 785                 memcpy(one_sha1, sha1_to_hex(one->sha1), 41);
 786
 787                 len += snprintf(msg + len, sizeof(msg) - len,
 788                                 "index %.*s..%.*s",
 789                                 abbrev, one_sha1, abbrev,
 790                                 sha1_to_hex(two->sha1));
 791                 if (one->mode == two->mode)
 792                         len += snprintf(msg + len, sizeof(msg) - len,
 793                                         " %06o", one->mode);
 794                 len += snprintf(msg + len, sizeof(msg) - len, "\n");
 795         }
 796
 797         if (len)
 798                 msg[--len] = 0;
 799         xfrm_msg = len ? msg : NULL;
 800
 801         if (!pgm &&
 802             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
 803             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
 804                 /* a filepair that changes between file and symlink
 805                  * needs to be split into deletion and creation.
 806                  */
 807                 struct diff_filespec *null = alloc_filespec(two->path);
 808                 run_diff_cmd(NULL, name, other, one, null, xfrm_msg, 0);
 809                 free(null);
 810                 null = alloc_filespec(one->path);
 811                 run_diff_cmd(NULL, name, other, null, two, xfrm_msg, 0);
 812                 free(null);
 813         }
 814         else
 815                 run_diff_cmd(pgm, name, other, one, two, xfrm_msg,
 816                              complete_rewrite);
 817
 818         free(name_munged);
 819         free(other_munged);
 820 }
 821
 822 void diff_setup(struct diff_options *options)
 823 {
 824         memset(options, 0, sizeof(*options));
 825         options->output_format = DIFF_FORMAT_RAW;
 826         options->line_termination = '\n';
 827         options->break_opt = -1;
 828         options->rename_limit = -1;
 829
 830         options->change = diff_change;
 831         options->add_remove = diff_addremove;
 832 }
 833
 834 int diff_setup_done(struct diff_options *options)
 835 {
 836         if ((options->find_copies_harder &&
 837              options->detect_rename != DIFF_DETECT_COPY) ||
 838             (0 <= options->rename_limit && !options->detect_rename))
 839                 return -1;
 840         if (options->detect_rename && options->rename_limit < 0)
 841                 options->rename_limit = diff_rename_limit_default;
 842         if (options->setup & DIFF_SETUP_USE_CACHE) {
 843                 if (!active_cache)
 844                         /* read-cache does not die even when it fails
 845                          * so it is safe for us to do this here.  Also
 846                          * it does not smudge active_cache or active_nr
 847                          * when it fails, so we do not have to worry about
 848                          * cleaning it up ourselves either.
 849                          */
 850                         read_cache();
 851         }
 852         if (options->setup & DIFF_SETUP_USE_SIZE_CACHE)
 853                 use_size_cache = 1;
 854         if (options->abbrev <= 0 || 40 < options->abbrev)
 855                 options->abbrev = 40; /* full */
 856
 857         return 0;
 858 }
 859
 860 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 861 {
 862         const char *arg = av[0];
 863         if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
 864                 options->output_format = DIFF_FORMAT_PATCH;
 865         else if (!strcmp(arg, "--patch-with-raw")) {
 866                 options->output_format = DIFF_FORMAT_PATCH;
 867                 options->with_raw = 1;
 868         }
 869         else if (!strcmp(arg, "-z"))
 870                 options->line_termination = 0;
 871         else if (!strncmp(arg, "-l", 2))
 872                 options->rename_limit = strtoul(arg+2, NULL, 10);
 873         else if (!strcmp(arg, "--full-index"))
 874                 options->full_index = 1;
 875         else if (!strcmp(arg, "--name-only"))
 876                 options->output_format = DIFF_FORMAT_NAME;
 877         else if (!strcmp(arg, "--name-status"))
 878                 options->output_format = DIFF_FORMAT_NAME_STATUS;
 879         else if (!strcmp(arg, "-R"))
 880                 options->reverse_diff = 1;
 881         else if (!strncmp(arg, "-S", 2))
 882                 options->pickaxe = arg + 2;
 883         else if (!strcmp(arg, "-s"))
 884                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
 885         else if (!strncmp(arg, "-O", 2))
 886                 options->orderfile = arg + 2;
 887         else if (!strncmp(arg, "--diff-filter=", 14))
 888                 options->filter = arg + 14;
 889         else if (!strcmp(arg, "--pickaxe-all"))
 890                 options->pickaxe_opts = DIFF_PICKAXE_ALL;
 891         else if (!strcmp(arg, "--pickaxe-regex"))
 892                 options->pickaxe_opts = DIFF_PICKAXE_REGEX;
 893         else if (!strncmp(arg, "-B", 2)) {
 894                 if ((options->break_opt =
 895                      diff_scoreopt_parse(arg)) == -1)
 896                         return -1;
 897         }
 898         else if (!strncmp(arg, "-M", 2)) {
 899                 if ((options->rename_score =
 900                      diff_scoreopt_parse(arg)) == -1)
 901                         return -1;
 902                 options->detect_rename = DIFF_DETECT_RENAME;
 903         }
 904         else if (!strncmp(arg, "-C", 2)) {
 905                 if ((options->rename_score =
 906                      diff_scoreopt_parse(arg)) == -1)
 907                         return -1;
 908                 options->detect_rename = DIFF_DETECT_COPY;
 909         }
 910         else if (!strcmp(arg, "--find-copies-harder"))
 911                 options->find_copies_harder = 1;
 912         else if (!strcmp(arg, "--abbrev"))
 913                 options->abbrev = DEFAULT_ABBREV;
 914         else if (!strncmp(arg, "--abbrev=", 9)) {
 915                 options->abbrev = strtoul(arg + 9, NULL, 10);
 916                 if (options->abbrev < MINIMUM_ABBREV)
 917                         options->abbrev = MINIMUM_ABBREV;
 918                 else if (40 < options->abbrev)
 919                         options->abbrev = 40;
 920         }
 921         else
 922                 return 0;
 923         return 1;
 924 }
 925
 926 static int parse_num(const char **cp_p)
 927 {
 928         unsigned long num, scale;
 929         int ch, dot;
 930         const char *cp = *cp_p;
 931
 932         num = 0;
 933         scale = 1;
 934         dot = 0;
 935         for(;;) {
 936                 ch = *cp;
 937                 if ( !dot && ch == '.' ) {
 938                         scale = 1;
 939                         dot = 1;
 940                 } else if ( ch == '%' ) {
 941                         scale = dot ? scale*100 : 100;
 942                         cp++;   /* % is always at the end */
 943                         break;
 944                 } else if ( ch >= '0' && ch <= '9' ) {
 945                         if ( scale < 100000 ) {
 946                                 scale *= 10;
 947                                 num = (num*10) + (ch-'0');
 948                         }
 949                 } else {
 950                         break;
 951                 }
 952                 cp++;
 953         }
 954         *cp_p = cp;
 955
 956         /* user says num divided by scale and we say internally that
 957          * is MAX_SCORE * num / scale.
 958          */
 959         return (num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale);
 960 }
 961
 962 int diff_scoreopt_parse(const char *opt)
 963 {
 964         int opt1, opt2, cmd;
 965
 966         if (*opt++ != '-')
 967                 return -1;
 968         cmd = *opt++;
 969         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
 970                 return -1; /* that is not a -M, -C nor -B option */
 971
 972         opt1 = parse_num(&opt);
 973         if (cmd != 'B')
 974                 opt2 = 0;
 975         else {
 976                 if (*opt == 0)
 977                         opt2 = 0;
 978                 else if (*opt != '/')
 979                         return -1; /* we expect -B80/99 or -B80 */
 980                 else {
 981                         opt++;
 982                         opt2 = parse_num(&opt);
 983                 }
 984         }
 985         if (*opt != 0)
 986                 return -1;
 987         return opt1 | (opt2 << 16);
 988 }
 989
 990 struct diff_queue_struct diff_queued_diff;
 991
 992 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
 993 {
 994         if (queue->alloc <= queue->nr) {
 995                 queue->alloc = alloc_nr(queue->alloc);
 996                 queue->queue = xrealloc(queue->queue,
 997                                         sizeof(dp) * queue->alloc);
 998         }
 999         queue->queue[queue->nr++] = dp;
1000 }
1001
1002 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
1003                                  struct diff_filespec *one,
1004                                  struct diff_filespec *two)
1005 {
1006         struct diff_filepair *dp = xmalloc(sizeof(*dp));
1007         dp->one = one;
1008         dp->two = two;
1009         dp->score = 0;
1010         dp->status = 0;
1011         dp->source_stays = 0;
1012         dp->broken_pair = 0;
1013         if (queue)
1014                 diff_q(queue, dp);
1015         return dp;
1016 }
1017
1018 void diff_free_filepair(struct diff_filepair *p)
1019 {
1020         diff_free_filespec_data(p->one);
1021         diff_free_filespec_data(p->two);
1022         free(p->one);
1023         free(p->two);
1024         free(p);
1025 }
1026
1027 /* This is different from find_unique_abbrev() in that
1028  * it stuffs the result with dots for alignment.
1029  */
1030 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
1031 {
1032         int abblen;
1033         const char *abbrev;
1034         if (len == 40)
1035                 return sha1_to_hex(sha1);
1036
1037         abbrev = find_unique_abbrev(sha1, len);
1038         if (!abbrev)
1039                 return sha1_to_hex(sha1);
1040         abblen = strlen(abbrev);
1041         if (abblen < 37) {
1042                 static char hex[41];
1043                 if (len < abblen && abblen <= len + 2)
1044                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
1045                 else
1046                         sprintf(hex, "%s...", abbrev);
1047                 return hex;
1048         }
1049         return sha1_to_hex(sha1);
1050 }
1051
1052 static void diff_flush_raw(struct diff_filepair *p,
1053                            int line_termination,
1054                            int inter_name_termination,
1055                            struct diff_options *options,
1056                            int output_format)
1057 {
1058         int two_paths;
1059         char status[10];
1060         int abbrev = options->abbrev;
1061         const char *path_one, *path_two;
1062
1063         path_one = p->one->path;
1064         path_two = p->two->path;
1065         if (line_termination) {
1066                 path_one = quote_one(path_one);
1067                 path_two = quote_one(path_two);
1068         }
1069
1070         if (p->score)
1071                 sprintf(status, "%c%03d", p->status,
1072                         (int)(0.5 + p->score * 100.0/MAX_SCORE));
1073         else {
1074                 status[0] = p->status;
1075                 status[1] = 0;
1076         }
1077         switch (p->status) {
1078         case DIFF_STATUS_COPIED:
1079         case DIFF_STATUS_RENAMED:
1080                 two_paths = 1;
1081                 break;
1082         case DIFF_STATUS_ADDED:
1083         case DIFF_STATUS_DELETED:
1084                 two_paths = 0;
1085                 break;
1086         default:
1087                 two_paths = 0;
1088                 break;
1089         }
1090         if (output_format != DIFF_FORMAT_NAME_STATUS) {
1091                 printf(":%06o %06o %s ",
1092                        p->one->mode, p->two->mode,
1093                        diff_unique_abbrev(p->one->sha1, abbrev));
1094                 printf("%s ",
1095                        diff_unique_abbrev(p->two->sha1, abbrev));
1096         }
1097         printf("%s%c%s", status, inter_name_termination, path_one);
1098         if (two_paths)
1099                 printf("%c%s", inter_name_termination, path_two);
1100         putchar(line_termination);
1101         if (path_one != p->one->path)
1102                 free((void*)path_one);
1103         if (path_two != p->two->path)
1104                 free((void*)path_two);
1105 }
1106
1107 static void diff_flush_name(struct diff_filepair *p,
1108                             int inter_name_termination,
1109                             int line_termination)
1110 {
1111         char *path = p->two->path;
1112
1113         if (line_termination)
1114                 path = quote_one(p->two->path);
1115         else
1116                 path = p->two->path;
1117         printf("%s%c", path, line_termination);
1118         if (p->two->path != path)
1119                 free(path);
1120 }
1121
1122 int diff_unmodified_pair(struct diff_filepair *p)
1123 {
1124         /* This function is written stricter than necessary to support
1125          * the currently implemented transformers, but the idea is to
1126          * let transformers to produce diff_filepairs any way they want,
1127          * and filter and clean them up here before producing the output.
1128          */
1129         struct diff_filespec *one, *two;
1130
1131         if (DIFF_PAIR_UNMERGED(p))
1132                 return 0; /* unmerged is interesting */
1133
1134         one = p->one;
1135         two = p->two;
1136
1137         /* deletion, addition, mode or type change
1138          * and rename are all interesting.
1139          */
1140         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
1141             DIFF_PAIR_MODE_CHANGED(p) ||
1142             strcmp(one->path, two->path))
1143                 return 0;
1144
1145         /* both are valid and point at the same path.  that is, we are
1146          * dealing with a change.
1147          */
1148         if (one->sha1_valid && two->sha1_valid &&
1149             !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
1150                 return 1; /* no change */
1151         if (!one->sha1_valid && !two->sha1_valid)
1152                 return 1; /* both look at the same file on the filesystem. */
1153         return 0;
1154 }
1155
1156 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
1157 {
1158         if (diff_unmodified_pair(p))
1159                 return;
1160
1161         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1162             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1163                 return; /* no tree diffs in patch format */
1164
1165         run_diff(p, o);
1166 }
1167
1168 int diff_queue_is_empty(void)
1169 {
1170         struct diff_queue_struct *q = &diff_queued_diff;
1171         int i;
1172         for (i = 0; i < q->nr; i++)
1173                 if (!diff_unmodified_pair(q->queue[i]))
1174                         return 0;
1175         return 1;
1176 }
1177
1178 #if DIFF_DEBUG
1179 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
1180 {
1181         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
1182                 x, one ? one : "",
1183                 s->path,
1184                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
1185                 s->mode,
1186                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
1187         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
1188                 x, one ? one : "",
1189                 s->size, s->xfrm_flags);
1190 }
1191
1192 void diff_debug_filepair(const struct diff_filepair *p, int i)
1193 {
1194         diff_debug_filespec(p->one, i, "one");
1195         diff_debug_filespec(p->two, i, "two");
1196         fprintf(stderr, "score %d, status %c stays %d broken %d\n",
1197                 p->score, p->status ? p->status : '?',
1198                 p->source_stays, p->broken_pair);
1199 }
1200
1201 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
1202 {
1203         int i;
1204         if (msg)
1205                 fprintf(stderr, "%s\n", msg);
1206         fprintf(stderr, "q->nr = %d\n", q->nr);
1207         for (i = 0; i < q->nr; i++) {
1208                 struct diff_filepair *p = q->queue[i];
1209                 diff_debug_filepair(p, i);
1210         }
1211 }
1212 #endif
1213
1214 static void diff_resolve_rename_copy(void)
1215 {
1216         int i, j;
1217         struct diff_filepair *p, *pp;
1218         struct diff_queue_struct *q = &diff_queued_diff;
1219
1220         diff_debug_queue("resolve-rename-copy", q);
1221
1222         for (i = 0; i < q->nr; i++) {
1223                 p = q->queue[i];
1224                 p->status = 0; /* undecided */
1225                 if (DIFF_PAIR_UNMERGED(p))
1226                         p->status = DIFF_STATUS_UNMERGED;
1227                 else if (!DIFF_FILE_VALID(p->one))
1228                         p->status = DIFF_STATUS_ADDED;
1229                 else if (!DIFF_FILE_VALID(p->two))
1230                         p->status = DIFF_STATUS_DELETED;
1231                 else if (DIFF_PAIR_TYPE_CHANGED(p))
1232                         p->status = DIFF_STATUS_TYPE_CHANGED;
1233
1234                 /* from this point on, we are dealing with a pair
1235                  * whose both sides are valid and of the same type, i.e.
1236                  * either in-place edit or rename/copy edit.
1237                  */
1238                 else if (DIFF_PAIR_RENAME(p)) {
1239                         if (p->source_stays) {
1240                                 p->status = DIFF_STATUS_COPIED;
1241                                 continue;
1242                         }
1243                         /* See if there is some other filepair that
1244                          * copies from the same source as us.  If so
1245                          * we are a copy.  Otherwise we are either a
1246                          * copy if the path stays, or a rename if it
1247                          * does not, but we already handled "stays" case.
1248                          */
1249                         for (j = i + 1; j < q->nr; j++) {
1250                                 pp = q->queue[j];
1251                                 if (strcmp(pp->one->path, p->one->path))
1252                                         continue; /* not us */
1253                                 if (!DIFF_PAIR_RENAME(pp))
1254                                         continue; /* not a rename/copy */
1255                                 /* pp is a rename/copy from the same source */
1256                                 p->status = DIFF_STATUS_COPIED;
1257                                 break;
1258                         }
1259                         if (!p->status)
1260                                 p->status = DIFF_STATUS_RENAMED;
1261                 }
1262                 else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
1263                          p->one->mode != p->two->mode)
1264                         p->status = DIFF_STATUS_MODIFIED;
1265                 else {
1266                         /* This is a "no-change" entry and should not
1267                          * happen anymore, but prepare for broken callers.
1268                          */
1269                         error("feeding unmodified %s to diffcore",
1270                               p->one->path);
1271                         p->status = DIFF_STATUS_UNKNOWN;
1272                 }
1273         }
1274         diff_debug_queue("resolve-rename-copy done", q);
1275 }
1276
1277 static void flush_one_pair(struct diff_filepair *p,
1278                            int diff_output_format,
1279                            struct diff_options *options)
1280 {
1281         int inter_name_termination = '\t';
1282         int line_termination = options->line_termination;
1283         if (!line_termination)
1284                 inter_name_termination = 0;
1285
1286         switch (p->status) {
1287         case DIFF_STATUS_UNKNOWN:
1288                 break;
1289         case 0:
1290                 die("internal error in diff-resolve-rename-copy");
1291                 break;
1292         default:
1293                 switch (diff_output_format) {
1294                 case DIFF_FORMAT_PATCH:
1295                         diff_flush_patch(p, options);
1296                         break;
1297                 case DIFF_FORMAT_RAW:
1298                 case DIFF_FORMAT_NAME_STATUS:
1299                         diff_flush_raw(p, line_termination,
1300                                        inter_name_termination,
1301                                        options, diff_output_format);
1302                         break;
1303                 case DIFF_FORMAT_NAME:
1304                         diff_flush_name(p,
1305                                         inter_name_termination,
1306                                         line_termination);
1307                         break;
1308                 case DIFF_FORMAT_NO_OUTPUT:
1309                         break;
1310                 }
1311         }
1312 }
1313
1314 void diff_flush(struct diff_options *options)
1315 {
1316         struct diff_queue_struct *q = &diff_queued_diff;
1317         int i;
1318         int diff_output_format = options->output_format;
1319
1320         if (options->with_raw) {
1321                 for (i = 0; i < q->nr; i++) {
1322                         struct diff_filepair *p = q->queue[i];
1323                         flush_one_pair(p, DIFF_FORMAT_RAW, options);
1324                 }
1325                 putchar(options->line_termination);
1326         }
1327         for (i = 0; i < q->nr; i++) {
1328                 struct diff_filepair *p = q->queue[i];
1329                 flush_one_pair(p, diff_output_format, options);
1330                 diff_free_filepair(p);
1331         }
1332         free(q->queue);
1333         q->queue = NULL;
1334         q->nr = q->alloc = 0;
1335 }
1336
1337 static void diffcore_apply_filter(const char *filter)
1338 {
1339         int i;
1340         struct diff_queue_struct *q = &diff_queued_diff;
1341         struct diff_queue_struct outq;
1342         outq.queue = NULL;
1343         outq.nr = outq.alloc = 0;
1344
1345         if (!filter)
1346                 return;
1347
1348         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
1349                 int found;
1350                 for (i = found = 0; !found && i < q->nr; i++) {
1351                         struct diff_filepair *p = q->queue[i];
1352                         if (((p->status == DIFF_STATUS_MODIFIED) &&
1353                              ((p->score &&
1354                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1355                               (!p->score &&
1356                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1357                             ((p->status != DIFF_STATUS_MODIFIED) &&
1358                              strchr(filter, p->status)))
1359                                 found++;
1360                 }
1361                 if (found)
1362                         return;
1363
1364                 /* otherwise we will clear the whole queue
1365                  * by copying the empty outq at the end of this
1366                  * function, but first clear the current entries
1367                  * in the queue.
1368                  */
1369                 for (i = 0; i < q->nr; i++)
1370                         diff_free_filepair(q->queue[i]);
1371         }
1372         else {
1373                 /* Only the matching ones */
1374                 for (i = 0; i < q->nr; i++) {
1375                         struct diff_filepair *p = q->queue[i];
1376
1377                         if (((p->status == DIFF_STATUS_MODIFIED) &&
1378                              ((p->score &&
1379                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1380                               (!p->score &&
1381                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1382                             ((p->status != DIFF_STATUS_MODIFIED) &&
1383                              strchr(filter, p->status)))
1384                                 diff_q(&outq, p);
1385                         else
1386                                 diff_free_filepair(p);
1387                 }
1388         }
1389         free(q->queue);
1390         *q = outq;
1391 }
1392
1393 void diffcore_std(struct diff_options *options)
1394 {
1395         if (options->break_opt != -1)
1396                 diffcore_break(options->break_opt);
1397         if (options->detect_rename)
1398                 diffcore_rename(options);
1399         if (options->break_opt != -1)
1400                 diffcore_merge_broken();
1401         if (options->pickaxe)
1402                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
1403         if (options->orderfile)
1404                 diffcore_order(options->orderfile);
1405         diff_resolve_rename_copy();
1406         diffcore_apply_filter(options->filter);
1407 }
1408
1409
1410 void diffcore_std_no_resolve(struct diff_options *options)
1411 {
1412         if (options->pickaxe)
1413                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
1414         if (options->orderfile)
1415                 diffcore_order(options->orderfile);
1416         diffcore_apply_filter(options->filter);
1417 }
1418
1419 void diff_addremove(struct diff_options *options,
1420                     int addremove, unsigned mode,
1421                     const unsigned char *sha1,
1422                     const char *base, const char *path)
1423 {
1424         char concatpath[PATH_MAX];
1425         struct diff_filespec *one, *two;
1426
1427         /* This may look odd, but it is a preparation for
1428          * feeding "there are unchanged files which should
1429          * not produce diffs, but when you are doing copy
1430          * detection you would need them, so here they are"
1431          * entries to the diff-core.  They will be prefixed
1432          * with something like '=' or '*' (I haven't decided
1433          * which but should not make any difference).
1434          * Feeding the same new and old to diff_change()
1435          * also has the same effect.
1436          * Before the final output happens, they are pruned after
1437          * merged into rename/copy pairs as appropriate.
1438          */
1439         if (options->reverse_diff)
1440                 addremove = (addremove == '+' ? '-' :
1441                              addremove == '-' ? '+' : addremove);
1442
1443         if (!path) path = "";
1444         sprintf(concatpath, "%s%s", base, path);
1445         one = alloc_filespec(concatpath);
1446         two = alloc_filespec(concatpath);
1447
1448         if (addremove != '+')
1449                 fill_filespec(one, sha1, mode);
1450         if (addremove != '-')
1451                 fill_filespec(two, sha1, mode);
1452
1453         diff_queue(&diff_queued_diff, one, two);
1454 }
1455
1456 void diff_change(struct diff_options *options,
1457                  unsigned old_mode, unsigned new_mode,
1458                  const unsigned char *old_sha1,
1459                  const unsigned char *new_sha1,
1460                  const char *base, const char *path)
1461 {
1462         char concatpath[PATH_MAX];
1463         struct diff_filespec *one, *two;
1464
1465         if (options->reverse_diff) {
1466                 unsigned tmp;
1467                 const unsigned char *tmp_c;
1468                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
1469                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
1470         }
1471         if (!path) path = "";
1472         sprintf(concatpath, "%s%s", base, path);
1473         one = alloc_filespec(concatpath);
1474         two = alloc_filespec(concatpath);
1475         fill_filespec(one, old_sha1, old_mode);
1476         fill_filespec(two, new_sha1, new_mode);
1477
1478         diff_queue(&diff_queued_diff, one, two);
1479 }
1480
1481 void diff_unmerge(struct diff_options *options,
1482                   const char *path)
1483 {
1484         struct diff_filespec *one, *two;
1485         one = alloc_filespec(path);
1486         two = alloc_filespec(path);
1487         diff_queue(&diff_queued_diff, one, two);
1488 }