git.oblomov.eu Git - git/blob - 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 "diff.h"
   9 #include "diffcore.h"
  10
  11 static const char *diff_opts = "-pu";
  12 static unsigned char null_sha1[20] = { 0, };
  13
  14 static int reverse_diff;
  15 static int use_size_cache;
  16
  17 static const char *external_diff(void)
  18 {
  19         static const char *external_diff_cmd = NULL;
  20         static int done_preparing = 0;
  21
  22         if (done_preparing)
  23                 return external_diff_cmd;
  24
  25         /*
  26          * Default values above are meant to match the
  27          * Linux kernel development style.  Examples of
  28          * alternative styles you can specify via environment
  29          * variables are:
  30          *
  31          * GIT_DIFF_OPTS="-c";
  32          */
  33         if (gitenv("GIT_EXTERNAL_DIFF"))
  34                 external_diff_cmd = gitenv("GIT_EXTERNAL_DIFF");
  35
  36         /* In case external diff fails... */
  37         diff_opts = gitenv("GIT_DIFF_OPTS") ? : diff_opts;
  38
  39         done_preparing = 1;
  40         return external_diff_cmd;
  41 }
  42
  43 /* Help to copy the thing properly quoted for the shell safety.
  44  * any single quote is replaced with '\'', and the caller is
  45  * expected to enclose the result within a single quote pair.
  46  *
  47  * E.g.
  48  *  original     sq_expand     result
  49  *  name     ==> name      ==> 'name'
  50  *  a b      ==> a b       ==> 'a b'
  51  *  a'b      ==> a'\''b    ==> 'a'\''b'
  52  */
  53 static char *sq_expand(const char *src)
  54 {
  55         static char *buf = NULL;
  56         int cnt, c;
  57         const char *cp;
  58         char *bp;
  59
  60         /* count bytes needed to store the quoted string. */
  61         for (cnt = 1, cp = src; *cp; cnt++, cp++)
  62                 if (*cp == '\'')
  63                         cnt += 3;
  64
  65         buf = xmalloc(cnt);
  66         bp = buf;
  67         while ((c = *src++)) {
  68                 if (c != '\'')
  69                         *bp++ = c;
  70                 else {
  71                         bp = strcpy(bp, "'\\''");
  72                         bp += 4;
  73                 }
  74         }
  75         *bp = 0;
  76         return buf;
  77 }
  78
  79 static struct diff_tempfile {
  80         const char *name; /* filename external diff should read from */
  81         char hex[41];
  82         char mode[10];
  83         char tmp_path[50];
  84 } diff_temp[2];
  85
  86 static void builtin_diff(const char *name_a,
  87                          const char *name_b,
  88                          struct diff_tempfile *temp,
  89                          const char *xfrm_msg)
  90 {
  91         int i, next_at, cmd_size;
  92         const char *diff_cmd = "diff -L'%s%s' -L'%s%s'";
  93         const char *diff_arg  = "'%s' '%s'||:"; /* "||:" is to return 0 */
  94         const char *input_name_sq[2];
  95         const char *path0[2];
  96         const char *path1[2];
  97         const char *name_sq[2];
  98         char *cmd;
  99
 100         name_sq[0] = sq_expand(name_a);
 101         name_sq[1] = sq_expand(name_b);
 102
 103         /* diff_cmd and diff_arg have 6 %s in total which makes
 104          * the sum of these strings 12 bytes larger than required.
 105          * we use 2 spaces around diff-opts, and we need to count
 106          * terminating NUL, so we subtract 9 here.
 107          */
 108         cmd_size = (strlen(diff_cmd) + strlen(diff_opts) +
 109                         strlen(diff_arg) - 9);
 110         for (i = 0; i < 2; i++) {
 111                 input_name_sq[i] = sq_expand(temp[i].name);
 112                 if (!strcmp(temp[i].name, "/dev/null")) {
 113                         path0[i] = "/dev/null";
 114                         path1[i] = "";
 115                 } else {
 116                         path0[i] = i ? "b/" : "a/";
 117                         path1[i] = name_sq[i];
 118                 }
 119                 cmd_size += (strlen(path0[i]) + strlen(path1[i]) +
 120                              strlen(input_name_sq[i]));
 121         }
 122
 123         cmd = xmalloc(cmd_size);
 124
 125         next_at = 0;
 126         next_at += snprintf(cmd+next_at, cmd_size-next_at,
 127                             diff_cmd,
 128                             path0[0], path1[0], path0[1], path1[1]);
 129         next_at += snprintf(cmd+next_at, cmd_size-next_at,
 130                             " %s ", diff_opts);
 131         next_at += snprintf(cmd+next_at, cmd_size-next_at,
 132                             diff_arg, input_name_sq[0], input_name_sq[1]);
 133
 134         printf("diff --git a/%s b/%s\n", name_a, name_b);
 135         if (!path1[0][0]) {
 136                 printf("new file mode %s\n", temp[1].mode);
 137                 if (xfrm_msg && xfrm_msg[0])
 138                         puts(xfrm_msg);
 139         }
 140         else if (!path1[1][0]) {
 141                 printf("deleted file mode %s\n", temp[0].mode);
 142                 if (xfrm_msg && xfrm_msg[0])
 143                         puts(xfrm_msg);
 144         }
 145         else {
 146                 if (strcmp(temp[0].mode, temp[1].mode)) {
 147                         printf("old mode %s\n", temp[0].mode);
 148                         printf("new mode %s\n", temp[1].mode);
 149                 }
 150                 if (xfrm_msg && xfrm_msg[0])
 151                         puts(xfrm_msg);
 152
 153                 if (strncmp(temp[0].mode, temp[1].mode, 3))
 154                         /* we do not run diff between different kind
 155                          * of objects.
 156                          */
 157                         exit(0);
 158         }
 159         fflush(NULL);
 160         execlp("/bin/sh","sh", "-c", cmd, NULL);
 161 }
 162
 163 struct diff_filespec *alloc_filespec(const char *path)
 164 {
 165         int namelen = strlen(path);
 166         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
 167         spec->path = (char *)(spec + 1);
 168         strcpy(spec->path, path);
 169         spec->should_free = spec->should_munmap = 0;
 170         spec->xfrm_flags = 0;
 171         spec->size = 0;
 172         spec->data = NULL;
 173         spec->mode = 0;
 174         memset(spec->sha1, 0, 20);
 175         return spec;
 176 }
 177
 178 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
 179                    unsigned short mode)
 180 {
 181         if (mode) {
 182                 spec->mode = DIFF_FILE_CANON_MODE(mode);
 183                 memcpy(spec->sha1, sha1, 20);
 184                 spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
 185         }
 186 }
 187
 188 /*
 189  * Given a name and sha1 pair, if the dircache tells us the file in
 190  * the work tree has that object contents, return true, so that
 191  * prepare_temp_file() does not have to inflate and extract.
 192  */
 193 static int work_tree_matches(const char *name, const unsigned char *sha1)
 194 {
 195         struct cache_entry *ce;
 196         struct stat st;
 197         int pos, len;
 198
 199         /* We do not read the cache ourselves here, because the
 200          * benchmark with my previous version that always reads cache
 201          * shows that it makes things worse for diff-tree comparing
 202          * two linux-2.6 kernel trees in an already checked out work
 203          * tree.  This is because most diff-tree comparisons deal with
 204          * only a small number of files, while reading the cache is
 205          * expensive for a large project, and its cost outweighs the
 206          * savings we get by not inflating the object to a temporary
 207          * file.  Practically, this code only helps when we are used
 208          * by diff-cache --cached, which does read the cache before
 209          * calling us.
 210          */
 211         if (!active_cache)
 212                 return 0;
 213
 214         len = strlen(name);
 215         pos = cache_name_pos(name, len);
 216         if (pos < 0)
 217                 return 0;
 218         ce = active_cache[pos];
 219         if ((lstat(name, &st) < 0) ||
 220             !S_ISREG(st.st_mode) || /* careful! */
 221             ce_match_stat(ce, &st) ||
 222             memcmp(sha1, ce->sha1, 20))
 223                 return 0;
 224         /* we return 1 only when we can stat, it is a regular file,
 225          * stat information matches, and sha1 recorded in the cache
 226          * matches.  I.e. we know the file in the work tree really is
 227          * the same as the <name, sha1> pair.
 228          */
 229         return 1;
 230 }
 231
 232 static struct sha1_size_cache {
 233         unsigned char sha1[20];
 234         unsigned long size;
 235 } **sha1_size_cache;
 236 static int sha1_size_cache_nr, sha1_size_cache_alloc;
 237
 238 static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
 239                                                  unsigned long size)
 240 {
 241         int first, last;
 242         struct sha1_size_cache *e;
 243
 244         first = 0;
 245         last = sha1_size_cache_nr;
 246         while (last > first) {
 247                 int next = (last + first) >> 1;
 248                 e = sha1_size_cache[next];
 249                 int cmp = memcmp(e->sha1, sha1, 20);
 250                 if (!cmp)
 251                         return e;
 252                 if (cmp < 0) {
 253                         last = next;
 254                         continue;
 255                 }
 256                 first = next+1;
 257         }
 258         /* not found */
 259         if (size == UINT_MAX)
 260                 return NULL;
 261         /* insert to make it at "first" */
 262         if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
 263                 sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
 264                 sha1_size_cache = xrealloc(sha1_size_cache,
 265                                            sha1_size_cache_alloc *
 266                                            sizeof(*sha1_size_cache));
 267         }
 268         sha1_size_cache_nr++;
 269         if (first < sha1_size_cache_nr)
 270                 memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
 271                         (sha1_size_cache_nr - first - 1) *
 272                         sizeof(*sha1_size_cache));
 273         e = xmalloc(sizeof(struct sha1_size_cache));
 274         sha1_size_cache[first] = e;
 275         memcpy(e->sha1, sha1, 20);
 276         e->size = size;
 277         return e;
 278 }
 279
 280 /*
 281  * While doing rename detection and pickaxe operation, we may need to
 282  * grab the data for the blob (or file) for our own in-core comparison.
 283  * diff_filespec has data and size fields for this purpose.
 284  */
 285 int diff_populate_filespec(struct diff_filespec *s, int size_only)
 286 {
 287         int err = 0;
 288         if (!DIFF_FILE_VALID(s))
 289                 die("internal error: asking to populate invalid file.");
 290         if (S_ISDIR(s->mode))
 291                 return -1;
 292
 293         if (!use_size_cache)
 294                 size_only = 0;
 295
 296         if (s->data)
 297                 return err;
 298         if (!s->sha1_valid ||
 299             work_tree_matches(s->path, s->sha1)) {
 300                 struct stat st;
 301                 int fd;
 302                 if (lstat(s->path, &st) < 0) {
 303                         if (errno == ENOENT) {
 304                         err_empty:
 305                                 err = -1;
 306                         empty:
 307                                 s->data = "";
 308                                 s->size = 0;
 309                                 return err;
 310                         }
 311                 }
 312                 s->size = st.st_size;
 313                 if (!s->size)
 314                         goto empty;
 315                 if (size_only)
 316                         return 0;
 317                 if (S_ISLNK(st.st_mode)) {
 318                         int ret;
 319                         s->data = xmalloc(s->size);
 320                         s->should_free = 1;
 321                         ret = readlink(s->path, s->data, s->size);
 322                         if (ret < 0) {
 323                                 free(s->data);
 324                                 goto err_empty;
 325                         }
 326                         return 0;
 327                 }
 328                 fd = open(s->path, O_RDONLY);
 329                 if (fd < 0)
 330                         goto err_empty;
 331                 s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
 332                 s->should_munmap = 1;
 333                 close(fd);
 334         }
 335         else {
 336                 char type[20];
 337                 struct sha1_size_cache *e;
 338
 339                 if (size_only) {
 340                         e = locate_size_cache(s->sha1, UINT_MAX);
 341                         if (e) {
 342                                 s->size = e->size;
 343                                 return 0;
 344                         }
 345                         if (!sha1_file_size(s->sha1, &s->size))
 346                                 locate_size_cache(s->sha1, s->size);
 347                 }
 348                 else {
 349                         s->data = read_sha1_file(s->sha1, type, &s->size);
 350                         s->should_free = 1;
 351                 }
 352         }
 353         return 0;
 354 }
 355
 356 void diff_free_filespec_data(struct diff_filespec *s)
 357 {
 358         if (s->should_free)
 359                 free(s->data);
 360         else if (s->should_munmap)
 361                 munmap(s->data, s->size);
 362         s->should_free = s->should_munmap = 0;
 363         s->data = NULL;
 364 }
 365
 366 static void prep_temp_blob(struct diff_tempfile *temp,
 367                            void *blob,
 368                            unsigned long size,
 369                            unsigned char *sha1,
 370                            int mode)
 371 {
 372         int fd;
 373
 374         strcpy(temp->tmp_path, ".diff_XXXXXX");
 375         fd = mkstemp(temp->tmp_path);
 376         if (fd < 0)
 377                 die("unable to create temp-file");
 378         if (write(fd, blob, size) != size)
 379                 die("unable to write temp-file");
 380         close(fd);
 381         temp->name = temp->tmp_path;
 382         strcpy(temp->hex, sha1_to_hex(sha1));
 383         temp->hex[40] = 0;
 384         sprintf(temp->mode, "%06o", mode);
 385 }
 386
 387 static void prepare_temp_file(const char *name,
 388                               struct diff_tempfile *temp,
 389                               struct diff_filespec *one)
 390 {
 391         if (!DIFF_FILE_VALID(one)) {
 392         not_a_valid_file:
 393                 /* A '-' entry produces this for file-2, and
 394                  * a '+' entry produces this for file-1.
 395                  */
 396                 temp->name = "/dev/null";
 397                 strcpy(temp->hex, ".");
 398                 strcpy(temp->mode, ".");
 399                 return;
 400         }
 401
 402         if (!one->sha1_valid ||
 403             work_tree_matches(name, one->sha1)) {
 404                 struct stat st;
 405                 if (lstat(name, &st) < 0) {
 406                         if (errno == ENOENT)
 407                                 goto not_a_valid_file;
 408                         die("stat(%s): %s", name, strerror(errno));
 409                 }
 410                 if (S_ISLNK(st.st_mode)) {
 411                         int ret;
 412                         char *buf, buf_[1024];
 413                         buf = ((sizeof(buf_) < st.st_size) ?
 414                                xmalloc(st.st_size) : buf_);
 415                         ret = readlink(name, buf, st.st_size);
 416                         if (ret < 0)
 417                                 die("readlink(%s)", name);
 418                         prep_temp_blob(temp, buf, st.st_size,
 419                                        (one->sha1_valid ?
 420                                         one->sha1 : null_sha1),
 421                                        (one->sha1_valid ?
 422                                         one->mode : S_IFLNK));
 423                 }
 424                 else {
 425                         /* we can borrow from the file in the work tree */
 426                         temp->name = name;
 427                         if (!one->sha1_valid)
 428                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
 429                         else
 430                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
 431                         /* Even though we may sometimes borrow the
 432                          * contents from the work tree, we always want
 433                          * one->mode.  mode is trustworthy even when
 434                          * !(one->sha1_valid), as long as
 435                          * DIFF_FILE_VALID(one).
 436                          */
 437                         sprintf(temp->mode, "%06o", one->mode);
 438                 }
 439                 return;
 440         }
 441         else {
 442                 if (diff_populate_filespec(one, 0))
 443                         die("cannot read data blob for %s", one->path);
 444                 prep_temp_blob(temp, one->data, one->size,
 445                                one->sha1, one->mode);
 446         }
 447 }
 448
 449 static void remove_tempfile(void)
 450 {
 451         int i;
 452
 453         for (i = 0; i < 2; i++)
 454                 if (diff_temp[i].name == diff_temp[i].tmp_path) {
 455                         unlink(diff_temp[i].name);
 456                         diff_temp[i].name = NULL;
 457                 }
 458 }
 459
 460 static void remove_tempfile_on_signal(int signo)
 461 {
 462         remove_tempfile();
 463 }
 464
 465 /* An external diff command takes:
 466  *
 467  * diff-cmd name infile1 infile1-sha1 infile1-mode \
 468  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
 469  *
 470  */
 471 static void run_external_diff(const char *pgm,
 472                               const char *name,
 473                               const char *other,
 474                               struct diff_filespec *one,
 475                               struct diff_filespec *two,
 476                               const char *xfrm_msg)
 477 {
 478         struct diff_tempfile *temp = diff_temp;
 479         pid_t pid;
 480         int status;
 481         static int atexit_asked = 0;
 482
 483         if (one && two) {
 484                 prepare_temp_file(name, &temp[0], one);
 485                 prepare_temp_file(other ? : name, &temp[1], two);
 486                 if (! atexit_asked &&
 487                     (temp[0].name == temp[0].tmp_path ||
 488                      temp[1].name == temp[1].tmp_path)) {
 489                         atexit_asked = 1;
 490                         atexit(remove_tempfile);
 491                 }
 492                 signal(SIGINT, remove_tempfile_on_signal);
 493         }
 494
 495         fflush(NULL);
 496         pid = fork();
 497         if (pid < 0)
 498                 die("unable to fork");
 499         if (!pid) {
 500                 if (pgm) {
 501                         if (one && two) {
 502                                 const char *exec_arg[10];
 503                                 const char **arg = &exec_arg[0];
 504                                 *arg++ = pgm;
 505                                 *arg++ = name;
 506                                 *arg++ = temp[0].name;
 507                                 *arg++ = temp[0].hex;
 508                                 *arg++ = temp[0].mode;
 509                                 *arg++ = temp[1].name;
 510                                 *arg++ = temp[1].hex;
 511                                 *arg++ = temp[1].mode;
 512                                 if (other) {
 513                                         *arg++ = other;
 514                                         *arg++ = xfrm_msg;
 515                                 }
 516                                 *arg = NULL;
 517                                 execvp(pgm, (char *const*) exec_arg);
 518                         }
 519                         else
 520                                 execlp(pgm, pgm, name, NULL);
 521                 }
 522                 /*
 523                  * otherwise we use the built-in one.
 524                  */
 525                 if (one && two)
 526                         builtin_diff(name, other ? : name, temp, xfrm_msg);
 527                 else
 528                         printf("* Unmerged path %s\n", name);
 529                 exit(0);
 530         }
 531         if (waitpid(pid, &status, 0) < 0 ||
 532             !WIFEXITED(status) || WEXITSTATUS(status)) {
 533                 /* Earlier we did not check the exit status because
 534                  * diff exits non-zero if files are different, and
 535                  * we are not interested in knowing that.  It was a
 536                  * mistake which made it harder to quit a diff-*
 537                  * session that uses the git-apply-patch-script as
 538                  * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
 539                  * should also exit non-zero only when it wants to
 540                  * abort the entire diff-* session.
 541                  */
 542                 remove_tempfile();
 543                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
 544                 exit(1);
 545         }
 546         remove_tempfile();
 547 }
 548
 549 static void run_diff(const char *name,
 550                      const char *other,
 551                      struct diff_filespec *one,
 552                      struct diff_filespec *two,
 553                      const char *xfrm_msg)
 554 {
 555         const char *pgm = external_diff();
 556         if (!pgm &&
 557             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
 558             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
 559                 /* a filepair that changes between file and symlink
 560                  * needs to be split into deletion and creation.
 561                  */
 562                 struct diff_filespec *null = alloc_filespec(two->path);
 563                 run_external_diff(NULL, name, other, one, null, xfrm_msg);
 564                 free(null);
 565                 null = alloc_filespec(one->path);
 566                 run_external_diff(NULL, name, other, null, two, xfrm_msg);
 567                 free(null);
 568         }
 569         else
 570                 run_external_diff(pgm, name, other, one, two, xfrm_msg);
 571 }
 572
 573 void diff_setup(int flags)
 574 {
 575         if (flags & DIFF_SETUP_REVERSE)
 576                 reverse_diff = 1;
 577         if (flags & DIFF_SETUP_USE_CACHE) {
 578                 if (!active_cache)
 579                         /* read-cache does not die even when it fails
 580                          * so it is safe for us to do this here.  Also
 581                          * it does not smudge active_cache or active_nr
 582                          * when it fails, so we do not have to worry about
 583                          * cleaning it up oufselves either.
 584                          */
 585                         read_cache();
 586         }
 587         if (flags & DIFF_SETUP_USE_SIZE_CACHE)
 588                 use_size_cache = 1;
 589
 590 }
 591
 592 static int parse_num(const char **cp_p)
 593 {
 594         int num, scale, ch, cnt;
 595         const char *cp = *cp_p;
 596
 597         cnt = num = 0;
 598         scale = 1;
 599         while ('0' <= (ch = *cp) && ch <= '9') {
 600                 if (cnt++ < 5) {
 601                         /* We simply ignore more than 5 digits precision. */
 602                         scale *= 10;
 603                         num = num * 10 + ch - '0';
 604                 }
 605                 *cp++;
 606         }
 607         *cp_p = cp;
 608
 609         /* user says num divided by scale and we say internally that
 610          * is MAX_SCORE * num / scale.
 611          */
 612         return (MAX_SCORE * num / scale);
 613 }
 614
 615 int diff_scoreopt_parse(const char *opt)
 616 {
 617         int opt1, cmd;
 618
 619         if (*opt++ != '-')
 620                 return -1;
 621         cmd = *opt++;
 622         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
 623                 return -1; /* that is not a -M, -C nor -B option */
 624
 625         opt1 = parse_num(&opt);
 626         if (*opt != 0)
 627                 return -1;
 628         return opt1;
 629 }
 630
 631 struct diff_queue_struct diff_queued_diff;
 632
 633 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
 634 {
 635         if (queue->alloc <= queue->nr) {
 636                 queue->alloc = alloc_nr(queue->alloc);
 637                 queue->queue = xrealloc(queue->queue,
 638                                         sizeof(dp) * queue->alloc);
 639         }
 640         queue->queue[queue->nr++] = dp;
 641 }
 642
 643 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
 644                                  struct diff_filespec *one,
 645                                  struct diff_filespec *two)
 646 {
 647         struct diff_filepair *dp = xmalloc(sizeof(*dp));
 648         dp->one = one;
 649         dp->two = two;
 650         dp->score = 0;
 651         dp->source_stays = 0;
 652         dp->broken_pair = 0;
 653         diff_q(queue, dp);
 654         return dp;
 655 }
 656
 657 void diff_free_filepair(struct diff_filepair *p)
 658 {
 659         diff_free_filespec_data(p->one);
 660         diff_free_filespec_data(p->two);
 661         free(p);
 662 }
 663
 664 static void diff_flush_raw(struct diff_filepair *p,
 665                            int line_termination,
 666                            int inter_name_termination)
 667 {
 668         int two_paths;
 669         char status[10];
 670
 671         if (line_termination) {
 672                 const char *err = "path %s cannot be expressed without -z";
 673                 if (strchr(p->one->path, line_termination) ||
 674                     strchr(p->one->path, inter_name_termination))
 675                         die(err, p->one->path);
 676                 if (strchr(p->two->path, line_termination) ||
 677                     strchr(p->two->path, inter_name_termination))
 678                         die(err, p->two->path);
 679         }
 680
 681         switch (p->status) {
 682         case 'C': case 'R':
 683                 two_paths = 1;
 684                 sprintf(status, "%c%03d", p->status,
 685                         (int)(0.5 + p->score * 100.0/MAX_SCORE));
 686                 break;
 687         case 'N': case 'D':
 688                 two_paths = 0;
 689                 if (p->score)
 690                         sprintf(status, "%c%03d", p->status,
 691                                 (int)(0.5 + p->score * 100.0/MAX_SCORE));
 692                 else {
 693                         status[0] = p->status;
 694                         status[1] = 0;
 695                 }
 696                 break;
 697         default:
 698                 two_paths = 0;
 699                 status[0] = p->status;
 700                 status[1] = 0;
 701                 break;
 702         }
 703         printf(":%06o %06o %s ",
 704                p->one->mode, p->two->mode, sha1_to_hex(p->one->sha1));
 705         printf("%s %s%c%s",
 706                sha1_to_hex(p->two->sha1),
 707                status,
 708                inter_name_termination,
 709                p->one->path);
 710         if (two_paths)
 711                 printf("%c%s", inter_name_termination, p->two->path);
 712         putchar(line_termination);
 713 }
 714
 715 int diff_unmodified_pair(struct diff_filepair *p)
 716 {
 717         /* This function is written stricter than necessary to support
 718          * the currently implemented transformers, but the idea is to
 719          * let transformers to produce diff_filepairs any way they want,
 720          * and filter and clean them up here before producing the output.
 721          */
 722         struct diff_filespec *one, *two;
 723
 724         if (DIFF_PAIR_UNMERGED(p))
 725                 return 0; /* unmerged is interesting */
 726
 727         one = p->one;
 728         two = p->two;
 729
 730         /* deletion, addition, mode or type change
 731          * and rename are all interesting.
 732          */
 733         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
 734             DIFF_PAIR_MODE_CHANGED(p) ||
 735             strcmp(one->path, two->path))
 736                 return 0;
 737
 738         /* both are valid and point at the same path.  that is, we are
 739          * dealing with a change.
 740          */
 741         if (one->sha1_valid && two->sha1_valid &&
 742             !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
 743                 return 1; /* no change */
 744         if (!one->sha1_valid && !two->sha1_valid)
 745                 return 1; /* both look at the same file on the filesystem. */
 746         return 0;
 747 }
 748
 749 static void diff_flush_patch(struct diff_filepair *p)
 750 {
 751         const char *name, *other;
 752         char msg_[PATH_MAX*2+200], *msg;
 753
 754         if (diff_unmodified_pair(p))
 755                 return;
 756
 757         name = p->one->path;
 758         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
 759         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
 760             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
 761                 return; /* no tree diffs in patch format */
 762
 763         switch (p->status) {
 764         case 'C':
 765                 sprintf(msg_,
 766                         "similarity index %d%%\n"
 767                         "copy from %s\n"
 768                         "copy to %s",
 769                         (int)(0.5 + p->score * 100.0/MAX_SCORE),
 770                         p->one->path, p->two->path);
 771                 msg = msg_;
 772                 break;
 773         case 'R':
 774                 sprintf(msg_,
 775                         "similarity index %d%%\n"
 776                         "rename old %s\n"
 777                         "rename new %s",
 778                         (int)(0.5 + p->score * 100.0/MAX_SCORE),
 779                         p->one->path, p->two->path);
 780                 msg = msg_;
 781                 break;
 782         case 'D': case 'N':
 783                 if (DIFF_PAIR_BROKEN(p)) {
 784                         sprintf(msg_,
 785                                 "dissimilarity index %d%%",
 786                                 (int)(0.5 + p->score * 100.0/MAX_SCORE));
 787                         msg = msg_;
 788                 }
 789                 else
 790                         msg = NULL;
 791                 break;
 792         default:
 793                 msg = NULL;
 794         }
 795
 796         if (DIFF_PAIR_UNMERGED(p))
 797                 run_diff(name, NULL, NULL, NULL, NULL);
 798         else
 799                 run_diff(name, other, p->one, p->two, msg);
 800 }
 801
 802 int diff_queue_is_empty(void)
 803 {
 804         struct diff_queue_struct *q = &diff_queued_diff;
 805         int i;
 806         for (i = 0; i < q->nr; i++)
 807                 if (!diff_unmodified_pair(q->queue[i]))
 808                         return 0;
 809         return 1;
 810 }
 811
 812 #if DIFF_DEBUG
 813 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
 814 {
 815         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
 816                 x, one ? : "",
 817                 s->path,
 818                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
 819                 s->mode,
 820                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
 821         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
 822                 x, one ? : "",
 823                 s->size, s->xfrm_flags);
 824 }
 825
 826 void diff_debug_filepair(const struct diff_filepair *p, int i)
 827 {
 828         diff_debug_filespec(p->one, i, "one");
 829         diff_debug_filespec(p->two, i, "two");
 830         fprintf(stderr, "score %d, status %c stays %d broken %d\n",
 831                 p->score, p->status ? : '?',
 832                 p->source_stays, p->broken_pair);
 833 }
 834
 835 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
 836 {
 837         int i;
 838         if (msg)
 839                 fprintf(stderr, "%s\n", msg);
 840         fprintf(stderr, "q->nr = %d\n", q->nr);
 841         for (i = 0; i < q->nr; i++) {
 842                 struct diff_filepair *p = q->queue[i];
 843                 diff_debug_filepair(p, i);
 844         }
 845 }
 846 #endif
 847
 848 static void diff_resolve_rename_copy(void)
 849 {
 850         int i, j;
 851         struct diff_filepair *p, *pp;
 852         struct diff_queue_struct *q = &diff_queued_diff;
 853
 854         diff_debug_queue("resolve-rename-copy", q);
 855
 856         for (i = 0; i < q->nr; i++) {
 857                 p = q->queue[i];
 858                 p->status = 0; /* undecided */
 859                 if (DIFF_PAIR_UNMERGED(p))
 860                         p->status = 'U';
 861                 else if (!DIFF_FILE_VALID(p->one))
 862                         p->status = 'N';
 863                 else if (!DIFF_FILE_VALID(p->two))
 864                         p->status = 'D';
 865                 else if (DIFF_PAIR_TYPE_CHANGED(p))
 866                         p->status = 'T';
 867
 868                 /* from this point on, we are dealing with a pair
 869                  * whose both sides are valid and of the same type, i.e.
 870                  * either in-place edit or rename/copy edit.
 871                  */
 872                 else if (DIFF_PAIR_RENAME(p)) {
 873                         if (p->source_stays) {
 874                                 p->status = 'C';
 875                                 continue;
 876                         }
 877                         /* See if there is some other filepair that
 878                          * copies from the same source as us.  If so
 879                          * we are a copy.  Otherwise we are a rename.
 880                          */
 881                         for (j = i + 1; j < q->nr; j++) {
 882                                 pp = q->queue[j];
 883                                 if (strcmp(pp->one->path, p->one->path))
 884                                         continue; /* not us */
 885                                 if (!DIFF_PAIR_RENAME(pp))
 886                                         continue; /* not a rename/copy */
 887                                 /* pp is a rename/copy from the same source */
 888                                 p->status = 'C';
 889                                 break;
 890                         }
 891                         if (!p->status)
 892                                 p->status = 'R';
 893                 }
 894                 else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
 895                          p->one->mode != p->two->mode)
 896                         p->status = 'M';
 897                 else {
 898                         /* This is a "no-change" entry and should not
 899                          * happen anymore, but prepare for broken callers.
 900                          */
 901                         error("feeding unmodified %s to diffcore",
 902                               p->one->path);
 903                         p->status = 'X';
 904                 }
 905         }
 906         diff_debug_queue("resolve-rename-copy done", q);
 907 }
 908
 909 void diff_flush(int diff_output_style, int resolve_rename_copy)
 910 {
 911         struct diff_queue_struct *q = &diff_queued_diff;
 912         int i;
 913         int line_termination = '\n';
 914         int inter_name_termination = '\t';
 915
 916         if (diff_output_style == DIFF_FORMAT_MACHINE)
 917                 line_termination = inter_name_termination = 0;
 918         if (resolve_rename_copy)
 919                 diff_resolve_rename_copy();
 920
 921         for (i = 0; i < q->nr; i++) {
 922                 struct diff_filepair *p = q->queue[i];
 923                 if ((diff_output_style == DIFF_FORMAT_NO_OUTPUT) ||
 924                     (p->status == 'X'))
 925                         continue;
 926                 if (p->status == 0)
 927                         die("internal error in diff-resolve-rename-copy");
 928                 switch (diff_output_style) {
 929                 case DIFF_FORMAT_PATCH:
 930                         diff_flush_patch(p);
 931                         break;
 932                 case DIFF_FORMAT_HUMAN:
 933                 case DIFF_FORMAT_MACHINE:
 934                         diff_flush_raw(p, line_termination,
 935                                        inter_name_termination);
 936                         break;
 937                 }
 938         }
 939         for (i = 0; i < q->nr; i++)
 940                 diff_free_filepair(q->queue[i]);
 941         free(q->queue);
 942         q->queue = NULL;
 943         q->nr = q->alloc = 0;
 944 }
 945
 946 void diffcore_std(const char **paths,
 947                   int detect_rename, int rename_score,
 948                   const char *pickaxe, int pickaxe_opts,
 949                   int break_opt,
 950                   const char *orderfile)
 951 {
 952         if (paths && paths[0])
 953                 diffcore_pathspec(paths);
 954         if (0 <= break_opt)
 955                 diffcore_break(break_opt);
 956         if (detect_rename)
 957                 diffcore_rename(detect_rename, rename_score);
 958         if (pickaxe)
 959                 diffcore_pickaxe(pickaxe, pickaxe_opts);
 960         if (orderfile)
 961                 diffcore_order(orderfile);
 962 }
 963
 964 void diff_addremove(int addremove, unsigned mode,
 965                     const unsigned char *sha1,
 966                     const char *base, const char *path)
 967 {
 968         char concatpath[PATH_MAX];
 969         struct diff_filespec *one, *two;
 970
 971         /* This may look odd, but it is a preparation for
 972          * feeding "there are unchanged files which should
 973          * not produce diffs, but when you are doing copy
 974          * detection you would need them, so here they are"
 975          * entries to the diff-core.  They will be prefixed
 976          * with something like '=' or '*' (I haven't decided
 977          * which but should not make any difference).
 978          * Feeding the same new and old to diff_change()
 979          * also has the same effect.
 980          * Before the final output happens, they are pruned after
 981          * merged into rename/copy pairs as appropriate.
 982          */
 983         if (reverse_diff)
 984                 addremove = (addremove == '+' ? '-' :
 985                              addremove == '-' ? '+' : addremove);
 986
 987         if (!path) path = "";
 988         sprintf(concatpath, "%s%s", base, path);
 989         one = alloc_filespec(concatpath);
 990         two = alloc_filespec(concatpath);
 991
 992         if (addremove != '+')
 993                 fill_filespec(one, sha1, mode);
 994         if (addremove != '-')
 995                 fill_filespec(two, sha1, mode);
 996
 997         diff_queue(&diff_queued_diff, one, two);
 998 }
 999
1000 void diff_helper_input(unsigned old_mode,
1001                        unsigned new_mode,
1002                        const unsigned char *old_sha1,
1003                        const unsigned char *new_sha1,
1004                        const char *old_path,
1005                        int status,
1006                        int score,
1007                        const char *new_path)
1008 {
1009         struct diff_filespec *one, *two;
1010         struct diff_filepair *dp;
1011
1012         one = alloc_filespec(old_path);
1013         two = alloc_filespec(new_path);
1014         if (old_mode)
1015                 fill_filespec(one, old_sha1, old_mode);
1016         if (new_mode)
1017                 fill_filespec(two, new_sha1, new_mode);
1018         dp = diff_queue(&diff_queued_diff, one, two);
1019         dp->score = score * MAX_SCORE / 100;
1020         dp->status = status;
1021 }
1022
1023 void diff_change(unsigned old_mode, unsigned new_mode,
1024                  const unsigned char *old_sha1,
1025                  const unsigned char *new_sha1,
1026                  const char *base, const char *path)
1027 {
1028         char concatpath[PATH_MAX];
1029         struct diff_filespec *one, *two;
1030
1031         if (reverse_diff) {
1032                 unsigned tmp;
1033                 const unsigned char *tmp_c;
1034                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
1035                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
1036         }
1037         if (!path) path = "";
1038         sprintf(concatpath, "%s%s", base, path);
1039         one = alloc_filespec(concatpath);
1040         two = alloc_filespec(concatpath);
1041         fill_filespec(one, old_sha1, old_mode);
1042         fill_filespec(two, new_sha1, new_mode);
1043
1044         diff_queue(&diff_queued_diff, one, two);
1045 }
1046
1047 void diff_unmerge(const char *path)
1048 {
1049         struct diff_filespec *one, *two;
1050         one = alloc_filespec(path);
1051         two = alloc_filespec(path);
1052         diff_queue(&diff_queued_diff, one, two);
1053 }