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