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 generate_patch;
  16 static int line_termination = '\n';
  17 static int inter_name_termination = '\t';
  18
  19 static const char *external_diff(void)
  20 {
  21         static const char *external_diff_cmd = NULL;
  22         static int done_preparing = 0;
  23
  24         if (done_preparing)
  25                 return external_diff_cmd;
  26
  27         /*
  28          * Default values above are meant to match the
  29          * Linux kernel development style.  Examples of
  30          * alternative styles you can specify via environment
  31          * variables are:
  32          *
  33          * GIT_DIFF_OPTS="-c";
  34          */
  35         if (gitenv("GIT_EXTERNAL_DIFF"))
  36                 external_diff_cmd = gitenv("GIT_EXTERNAL_DIFF");
  37
  38         /* In case external diff fails... */
  39         diff_opts = gitenv("GIT_DIFF_OPTS") ? : diff_opts;
  40
  41         done_preparing = 1;
  42         return external_diff_cmd;
  43 }
  44
  45 /* Help to copy the thing properly quoted for the shell safety.
  46  * any single quote is replaced with '\'', and the caller is
  47  * expected to enclose the result within a single quote pair.
  48  *
  49  * E.g.
  50  *  original     sq_expand     result
  51  *  name     ==> name      ==> 'name'
  52  *  a b      ==> a b       ==> 'a b'
  53  *  a'b      ==> a'\''b    ==> 'a'\''b'
  54  */
  55 static char *sq_expand(const char *src)
  56 {
  57         static char *buf = NULL;
  58         int cnt, c;
  59         const char *cp;
  60         char *bp;
  61
  62         /* count bytes needed to store the quoted string. */
  63         for (cnt = 1, cp = src; *cp; cnt++, cp++)
  64                 if (*cp == '\'')
  65                         cnt += 3;
  66
  67         buf = xmalloc(cnt);
  68         bp = buf;
  69         while ((c = *src++)) {
  70                 if (c != '\'')
  71                         *bp++ = c;
  72                 else {
  73                         bp = strcpy(bp, "'\\''");
  74                         bp += 4;
  75                 }
  76         }
  77         *bp = 0;
  78         return buf;
  79 }
  80
  81 static struct diff_tempfile {
  82         const char *name; /* filename external diff should read from */
  83         char hex[41];
  84         char mode[10];
  85         char tmp_path[50];
  86 } diff_temp[2];
  87
  88 static void builtin_diff(const char *name_a,
  89                          const char *name_b,
  90                          struct diff_tempfile *temp,
  91                          const char *xfrm_msg)
  92 {
  93         int i, next_at, cmd_size;
  94         const char *diff_cmd = "diff -L'%s%s' -L'%s%s'";
  95         const char *diff_arg  = "'%s' '%s'||:"; /* "||:" is to return 0 */
  96         const char *input_name_sq[2];
  97         const char *path0[2];
  98         const char *path1[2];
  99         const char *name_sq[2];
 100         char *cmd;
 101
 102         name_sq[0] = sq_expand(name_a);
 103         name_sq[1] = sq_expand(name_b);
 104
 105         /* diff_cmd and diff_arg have 6 %s in total which makes
 106          * the sum of these strings 12 bytes larger than required.
 107          * we use 2 spaces around diff-opts, and we need to count
 108          * terminating NUL, so we subtract 9 here.
 109          */
 110         cmd_size = (strlen(diff_cmd) + strlen(diff_opts) +
 111                         strlen(diff_arg) - 9);
 112         for (i = 0; i < 2; i++) {
 113                 input_name_sq[i] = sq_expand(temp[i].name);
 114                 if (!strcmp(temp[i].name, "/dev/null")) {
 115                         path0[i] = "/dev/null";
 116                         path1[i] = "";
 117                 } else {
 118                         path0[i] = i ? "b/" : "a/";
 119                         path1[i] = name_sq[i];
 120                 }
 121                 cmd_size += (strlen(path0[i]) + strlen(path1[i]) +
 122                              strlen(input_name_sq[i]));
 123         }
 124
 125         cmd = xmalloc(cmd_size);
 126
 127         next_at = 0;
 128         next_at += snprintf(cmd+next_at, cmd_size-next_at,
 129                             diff_cmd,
 130                             path0[0], path1[0], path0[1], path1[1]);
 131         next_at += snprintf(cmd+next_at, cmd_size-next_at,
 132                             " %s ", diff_opts);
 133         next_at += snprintf(cmd+next_at, cmd_size-next_at,
 134                             diff_arg, input_name_sq[0], input_name_sq[1]);
 135
 136         printf("diff --git a/%s b/%s\n", name_a, name_b);
 137         if (!path1[0][0])
 138                 printf("new file mode %s\n", temp[1].mode);
 139         else if (!path1[1][0])
 140                 printf("deleted file mode %s\n", temp[0].mode);
 141         else {
 142                 if (strcmp(temp[0].mode, temp[1].mode)) {
 143                         printf("old mode %s\n", temp[0].mode);
 144                         printf("new mode %s\n", temp[1].mode);
 145                 }
 146                 if (xfrm_msg && xfrm_msg[0])
 147                         fputs(xfrm_msg, stdout);
 148
 149                 if (strncmp(temp[0].mode, temp[1].mode, 3))
 150                         /* we do not run diff between different kind
 151                          * of objects.
 152                          */
 153                         exit(0);
 154         }
 155         fflush(NULL);
 156         execlp("/bin/sh","sh", "-c", cmd, NULL);
 157 }
 158
 159 struct diff_filespec *alloc_filespec(const char *path)
 160 {
 161         int namelen = strlen(path);
 162         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
 163         spec->path = (char *)(spec + 1);
 164         strcpy(spec->path, path);
 165         spec->should_free = spec->should_munmap = 0;
 166         spec->xfrm_flags = 0;
 167         spec->size = 0;
 168         spec->data = NULL;
 169         spec->mode = 0;
 170         memset(spec->sha1, 0, 20);
 171         return spec;
 172 }
 173
 174 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
 175                    unsigned short mode)
 176 {
 177         if (mode) { /* just playing defensive */
 178                 spec->mode = mode;
 179                 memcpy(spec->sha1, sha1, 20);
 180                 spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
 181         }
 182 }
 183
 184 /*
 185  * Given a name and sha1 pair, if the dircache tells us the file in
 186  * the work tree has that object contents, return true, so that
 187  * prepare_temp_file() does not have to inflate and extract.
 188  */
 189 static int work_tree_matches(const char *name, const unsigned char *sha1)
 190 {
 191         struct cache_entry *ce;
 192         struct stat st;
 193         int pos, len;
 194
 195         /* We do not read the cache ourselves here, because the
 196          * benchmark with my previous version that always reads cache
 197          * shows that it makes things worse for diff-tree comparing
 198          * two linux-2.6 kernel trees in an already checked out work
 199          * tree.  This is because most diff-tree comparisons deal with
 200          * only a small number of files, while reading the cache is
 201          * expensive for a large project, and its cost outweighs the
 202          * savings we get by not inflating the object to a temporary
 203          * file.  Practically, this code only helps when we are used
 204          * by diff-cache --cached, which does read the cache before
 205          * calling us.
 206          */
 207         if (!active_cache)
 208                 return 0;
 209
 210         len = strlen(name);
 211         pos = cache_name_pos(name, len);
 212         if (pos < 0)
 213                 return 0;
 214         ce = active_cache[pos];
 215         if ((lstat(name, &st) < 0) ||
 216             !S_ISREG(st.st_mode) || /* careful! */
 217             ce_match_stat(ce, &st) ||
 218             memcmp(sha1, ce->sha1, 20))
 219                 return 0;
 220         /* we return 1 only when we can stat, it is a regular file,
 221          * stat information matches, and sha1 recorded in the cache
 222          * matches.  I.e. we know the file in the work tree really is
 223          * the same as the <name, sha1> pair.
 224          */
 225         return 1;
 226 }
 227
 228 /*
 229  * While doing rename detection and pickaxe operation, we may need to
 230  * grab the data for the blob (or file) for our own in-core comparison.
 231  * diff_filespec has data and size fields for this purpose.
 232  */
 233 int diff_populate_filespec(struct diff_filespec *s)
 234 {
 235         int err = 0;
 236         if (!DIFF_FILE_VALID(s))
 237                 die("internal error: asking to populate invalid file.");
 238         if (S_ISDIR(s->mode))
 239                 return -1;
 240
 241         if (s->data)
 242                 return err;
 243         if (!s->sha1_valid ||
 244             work_tree_matches(s->path, s->sha1)) {
 245                 struct stat st;
 246                 int fd;
 247                 if (lstat(s->path, &st) < 0) {
 248                         if (errno == ENOENT) {
 249                         err_empty:
 250                                 err = -1;
 251                         empty:
 252                                 s->data = "";
 253                                 s->size = 0;
 254                                 return err;
 255                         }
 256                 }
 257                 s->size = st.st_size;
 258                 if (!s->size)
 259                         goto empty;
 260                 if (S_ISLNK(st.st_mode)) {
 261                         int ret;
 262                         s->data = xmalloc(s->size);
 263                         s->should_free = 1;
 264                         ret = readlink(s->path, s->data, s->size);
 265                         if (ret < 0) {
 266                                 free(s->data);
 267                                 goto err_empty;
 268                         }
 269                         return 0;
 270                 }
 271                 fd = open(s->path, O_RDONLY);
 272                 if (fd < 0)
 273                         goto err_empty;
 274                 s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
 275                 s->should_munmap = 1;
 276                 close(fd);
 277         }
 278         else {
 279                 char type[20];
 280                 s->data = read_sha1_file(s->sha1, type, &s->size);
 281                 s->should_free = 1;
 282         }
 283         return 0;
 284 }
 285
 286 void diff_free_filepair(struct diff_filepair *p)
 287 {
 288         free(p->xfrm_msg);
 289         free(p);
 290 }
 291
 292 void diff_free_filespec_data(struct diff_filespec *s)
 293 {
 294         if (s->should_free)
 295                 free(s->data);
 296         else if (s->should_munmap)
 297                 munmap(s->data, s->size);
 298         s->should_free = s->should_munmap = 0;
 299         s->data = NULL;
 300 }
 301
 302 static void prep_temp_blob(struct diff_tempfile *temp,
 303                            void *blob,
 304                            unsigned long size,
 305                            unsigned char *sha1,
 306                            int mode)
 307 {
 308         int fd;
 309
 310         strcpy(temp->tmp_path, ".diff_XXXXXX");
 311         fd = mkstemp(temp->tmp_path);
 312         if (fd < 0)
 313                 die("unable to create temp-file");
 314         if (write(fd, blob, size) != size)
 315                 die("unable to write temp-file");
 316         close(fd);
 317         temp->name = temp->tmp_path;
 318         strcpy(temp->hex, sha1_to_hex(sha1));
 319         temp->hex[40] = 0;
 320         sprintf(temp->mode, "%06o", mode);
 321 }
 322
 323 static void prepare_temp_file(const char *name,
 324                               struct diff_tempfile *temp,
 325                               struct diff_filespec *one)
 326 {
 327         if (!DIFF_FILE_VALID(one)) {
 328         not_a_valid_file:
 329                 /* A '-' entry produces this for file-2, and
 330                  * a '+' entry produces this for file-1.
 331                  */
 332                 temp->name = "/dev/null";
 333                 strcpy(temp->hex, ".");
 334                 strcpy(temp->mode, ".");
 335                 return;
 336         }
 337
 338         if (!one->sha1_valid ||
 339             work_tree_matches(name, one->sha1)) {
 340                 struct stat st;
 341                 if (lstat(name, &st) < 0) {
 342                         if (errno == ENOENT)
 343                                 goto not_a_valid_file;
 344                         die("stat(%s): %s", name, strerror(errno));
 345                 }
 346                 if (S_ISLNK(st.st_mode)) {
 347                         int ret;
 348                         char *buf, buf_[1024];
 349                         buf = ((sizeof(buf_) < st.st_size) ?
 350                                xmalloc(st.st_size) : buf_);
 351                         ret = readlink(name, buf, st.st_size);
 352                         if (ret < 0)
 353                                 die("readlink(%s)", name);
 354                         prep_temp_blob(temp, buf, st.st_size,
 355                                        (one->sha1_valid ?
 356                                         one->sha1 : null_sha1),
 357                                        (one->sha1_valid ?
 358                                         one->mode : S_IFLNK));
 359                 }
 360                 else {
 361                         /* we can borrow from the file in the work tree */
 362                         temp->name = name;
 363                         if (!one->sha1_valid)
 364                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
 365                         else
 366                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
 367                         sprintf(temp->mode, "%06o",
 368                                 S_IFREG |ce_permissions(st.st_mode));
 369                 }
 370                 return;
 371         }
 372         else {
 373                 if (diff_populate_filespec(one))
 374                         die("cannot read data blob for %s", one->path);
 375                 prep_temp_blob(temp, one->data, one->size,
 376                                one->sha1, one->mode);
 377         }
 378 }
 379
 380 static void remove_tempfile(void)
 381 {
 382         int i;
 383
 384         for (i = 0; i < 2; i++)
 385                 if (diff_temp[i].name == diff_temp[i].tmp_path) {
 386                         unlink(diff_temp[i].name);
 387                         diff_temp[i].name = NULL;
 388                 }
 389 }
 390
 391 static void remove_tempfile_on_signal(int signo)
 392 {
 393         remove_tempfile();
 394 }
 395
 396 /* An external diff command takes:
 397  *
 398  * diff-cmd name infile1 infile1-sha1 infile1-mode \
 399  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
 400  *
 401  */
 402 static void run_external_diff(const char *name,
 403                               const char *other,
 404                               struct diff_filespec *one,
 405                               struct diff_filespec *two,
 406                               const char *xfrm_msg)
 407 {
 408         struct diff_tempfile *temp = diff_temp;
 409         pid_t pid;
 410         int status;
 411         static int atexit_asked = 0;
 412
 413         if (one && two) {
 414                 prepare_temp_file(name, &temp[0], one);
 415                 prepare_temp_file(other ? : name, &temp[1], two);
 416                 if (! atexit_asked &&
 417                     (temp[0].name == temp[0].tmp_path ||
 418                      temp[1].name == temp[1].tmp_path)) {
 419                         atexit_asked = 1;
 420                         atexit(remove_tempfile);
 421                 }
 422                 signal(SIGINT, remove_tempfile_on_signal);
 423         }
 424
 425         fflush(NULL);
 426         pid = fork();
 427         if (pid < 0)
 428                 die("unable to fork");
 429         if (!pid) {
 430                 const char *pgm = external_diff();
 431                 if (pgm) {
 432                         if (one && two) {
 433                                 const char *exec_arg[10];
 434                                 const char **arg = &exec_arg[0];
 435                                 *arg++ = pgm;
 436                                 *arg++ = name;
 437                                 *arg++ = temp[0].name;
 438                                 *arg++ = temp[0].hex;
 439                                 *arg++ = temp[0].mode;
 440                                 *arg++ = temp[1].name;
 441                                 *arg++ = temp[1].hex;
 442                                 *arg++ = temp[1].mode;
 443                                 if (other) {
 444                                         *arg++ = other;
 445                                         *arg++ = xfrm_msg;
 446                                 }
 447                                 *arg = NULL;
 448                                 execvp(pgm, (char *const*) exec_arg);
 449                         }
 450                         else
 451                                 execlp(pgm, pgm, name, NULL);
 452                 }
 453                 /*
 454                  * otherwise we use the built-in one.
 455                  */
 456                 if (one && two)
 457                         builtin_diff(name, other ? : name, temp, xfrm_msg);
 458                 else
 459                         printf("* Unmerged path %s\n", name);
 460                 exit(0);
 461         }
 462         if (waitpid(pid, &status, 0) < 0 ||
 463             !WIFEXITED(status) || WEXITSTATUS(status)) {
 464                 /* Earlier we did not check the exit status because
 465                  * diff exits non-zero if files are different, and
 466                  * we are not interested in knowing that.  It was a
 467                  * mistake which made it harder to quit a diff-*
 468                  * session that uses the git-apply-patch-script as
 469                  * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
 470                  * should also exit non-zero only when it wants to
 471                  * abort the entire diff-* session.
 472                  */
 473                 remove_tempfile();
 474                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
 475                 exit(1);
 476         }
 477         remove_tempfile();
 478 }
 479
 480 void diff_setup(int reverse_diff_)
 481 {
 482         reverse_diff = reverse_diff_;
 483 }
 484
 485 struct diff_queue_struct diff_queued_diff;
 486
 487 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
 488 {
 489         if (queue->alloc <= queue->nr) {
 490                 queue->alloc = alloc_nr(queue->alloc);
 491                 queue->queue = xrealloc(queue->queue,
 492                                         sizeof(dp) * queue->alloc);
 493         }
 494         queue->queue[queue->nr++] = dp;
 495 }
 496
 497 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
 498                                  struct diff_filespec *one,
 499                                  struct diff_filespec *two)
 500 {
 501         struct diff_filepair *dp = xmalloc(sizeof(*dp));
 502         dp->one = one;
 503         dp->two = two;
 504         dp->xfrm_msg = NULL;
 505         dp->orig_order = queue->nr;
 506         dp->xfrm_work = 0;
 507         diff_q(queue, dp);
 508         return dp;
 509 }
 510
 511 static void diff_flush_raw(struct diff_filepair *p)
 512 {
 513         if (DIFF_PAIR_UNMERGED(p)) {
 514                 printf("U %s%c", p->one->path, line_termination);
 515                 return;
 516         }
 517         printf(":%06o %06o %s ",
 518                p->one->mode, p->two->mode, sha1_to_hex(p->one->sha1));
 519         printf("%s%c%s%c%s%c",
 520                sha1_to_hex(p->two->sha1), inter_name_termination,
 521                p->one->path, inter_name_termination,
 522                p->two->path, line_termination);
 523 }
 524
 525 static void diff_flush_patch(struct diff_filepair *p)
 526 {
 527         const char *name, *other;
 528
 529         name = p->one->path;
 530         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
 531         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
 532             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
 533                 return; /* no tree diffs in patch format */
 534
 535         if (DIFF_PAIR_UNMERGED(p))
 536                 run_external_diff(name, NULL, NULL, NULL, NULL);
 537         else
 538                 run_external_diff(name, other, p->one, p->two, p->xfrm_msg);
 539 }
 540
 541 static int uninteresting(struct diff_filepair *p)
 542 {
 543         /* This function is written stricter than necessary to support
 544          * the currently implemented transformers, but the idea is to
 545          * let transformers to produce diff_filepairs any way they want,
 546          * and filter and clean them up here before producing the output.
 547          */
 548         struct diff_filespec *one, *two;
 549
 550         if (DIFF_PAIR_UNMERGED(p))
 551                 return 0; /* unmerged is interesting */
 552
 553         one = p->one;
 554         two = p->two;
 555
 556         /* deletion, addition, mode change and renames are all interesting. */
 557         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
 558             (one->mode != two->mode) ||
 559             strcmp(one->path, two->path))
 560                 return 0;
 561
 562         /* both are valid and point at the same path.  that is, we are
 563          * dealing with a change.
 564          */
 565         if (one->sha1_valid && two->sha1_valid &&
 566             !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
 567                 return 1; /* no change */
 568         if (!one->sha1_valid && !two->sha1_valid)
 569                 return 1; /* both look at the same file on the filesystem. */
 570         return 0;
 571 }
 572
 573 void diffcore_prune(void)
 574 {
 575         /*
 576          * Although rename/copy detection wants to have "no-change"
 577          * entries fed into them, the downstream do not need to see
 578          * them.  This function removes such entries.
 579          *
 580          * The applications that use rename/copy should:
 581          *
 582          * (1) feed change and "no-change" entries via diff_queue().
 583          * (2) call diffcore_rename, and any other future diffcore_xxx
 584          *     that would benefit by still having "no-change" entries.
 585          * (3) call diffcore_prune
 586          * (4) call other diffcore_xxx that do not need to see
 587          *     "no-change" entries.
 588          */
 589         struct diff_queue_struct *q = &diff_queued_diff;
 590         struct diff_queue_struct outq;
 591         int i;
 592
 593         outq.queue = NULL;
 594         outq.nr = outq.alloc = 0;
 595
 596         for (i = 0; i < q->nr; i++) {
 597                 struct diff_filepair *p = q->queue[i];
 598                 if (!uninteresting(p))
 599                         diff_q(&outq, p);
 600                 else
 601                         diff_free_filepair(p);
 602         }
 603         free(q->queue);
 604         *q = outq;
 605         return;
 606 }
 607
 608 static void diff_flush_one(struct diff_filepair *p)
 609 {
 610         if (uninteresting(p))
 611                 return;
 612         if (generate_patch)
 613                 diff_flush_patch(p);
 614         else
 615                 diff_flush_raw(p);
 616 }
 617
 618 int diff_queue_is_empty(void)
 619 {
 620         struct diff_queue_struct *q = &diff_queued_diff;
 621         int i;
 622
 623         for (i = 0; i < q->nr; i++) {
 624                 struct diff_filepair *p = q->queue[i];
 625                 if (!uninteresting(p))
 626                         return 0;
 627         }
 628         return 1;
 629 }
 630
 631 void diff_flush(int diff_output_style)
 632 {
 633         struct diff_queue_struct *q = &diff_queued_diff;
 634         int i;
 635
 636         generate_patch = 0;
 637         switch (diff_output_style) {
 638         case DIFF_FORMAT_HUMAN:
 639                 line_termination = '\n';
 640                 inter_name_termination = '\t';
 641                 break;
 642         case DIFF_FORMAT_MACHINE:
 643                 line_termination = inter_name_termination = 0;
 644                 break;
 645         case DIFF_FORMAT_PATCH:
 646                 generate_patch = 1;
 647                 break;
 648         }
 649         for (i = 0; i < q->nr; i++)
 650                 diff_flush_one(q->queue[i]);
 651         for (i = 0; i < q->nr; i++) {
 652                 struct diff_filepair *p = q->queue[i];
 653                 diff_free_filespec_data(p->one);
 654                 diff_free_filespec_data(p->two);
 655                 free(p->xfrm_msg);
 656                 free(p);
 657         }
 658         free(q->queue);
 659         q->queue = NULL;
 660         q->nr = q->alloc = 0;
 661 }
 662
 663 void diff_addremove(int addremove, unsigned mode,
 664                     const unsigned char *sha1,
 665                     const char *base, const char *path)
 666 {
 667         char concatpath[PATH_MAX];
 668         struct diff_filespec *one, *two;
 669
 670         /* This may look odd, but it is a preparation for
 671          * feeding "there are unchanged files which should
 672          * not produce diffs, but when you are doing copy
 673          * detection you would need them, so here they are"
 674          * entries to the diff-core.  They will be prefixed
 675          * with something like '=' or '*' (I haven't decided
 676          * which but should not make any difference).
 677          * Feeding the same new and old to diff_change() should
 678          * also have the same effect.  diff_flush() should
 679          * filter uninteresting ones out at the final output
 680          * stage.
 681          */
 682         if (reverse_diff)
 683                 addremove = (addremove == '+' ? '-' :
 684                              addremove == '-' ? '+' : addremove);
 685
 686         if (!path) path = "";
 687         sprintf(concatpath, "%s%s", base, path);
 688         one = alloc_filespec(concatpath);
 689         two = alloc_filespec(concatpath);
 690
 691         if (addremove != '+')
 692                 fill_filespec(one, sha1, mode);
 693         if (addremove != '-')
 694                 fill_filespec(two, sha1, mode);
 695
 696         diff_queue(&diff_queued_diff, one, two);
 697 }
 698
 699 void diff_guif(unsigned old_mode,
 700                unsigned new_mode,
 701                const unsigned char *old_sha1,
 702                const unsigned char *new_sha1,
 703                const char *old_path,
 704                const char *new_path)
 705 {
 706         struct diff_filespec *one, *two;
 707
 708         if (reverse_diff) {
 709                 unsigned tmp;
 710                 const unsigned char *tmp_c;
 711                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
 712                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
 713         }
 714         one = alloc_filespec(old_path);
 715         two = alloc_filespec(new_path);
 716         if (old_mode)
 717                 fill_filespec(one, old_sha1, old_mode);
 718         if (new_mode)
 719                 fill_filespec(two, new_sha1, new_mode);
 720         diff_queue(&diff_queued_diff, one, two);
 721 }
 722
 723 void diff_change(unsigned old_mode, unsigned new_mode,
 724                  const unsigned char *old_sha1,
 725                  const unsigned char *new_sha1,
 726                  const char *base, const char *path)
 727 {
 728         char concatpath[PATH_MAX];
 729         struct diff_filespec *one, *two;
 730
 731         if (reverse_diff) {
 732                 unsigned tmp;
 733                 const unsigned char *tmp_c;
 734                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
 735                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
 736         }
 737         if (!path) path = "";
 738         sprintf(concatpath, "%s%s", base, path);
 739         one = alloc_filespec(concatpath);
 740         two = alloc_filespec(concatpath);
 741         fill_filespec(one, old_sha1, old_mode);
 742         fill_filespec(two, new_sha1, new_mode);
 743
 744         diff_queue(&diff_queued_diff, one, two);
 745 }
 746
 747 void diff_unmerge(const char *path)
 748 {
 749         struct diff_filespec *one, *two;
 750         one = alloc_filespec(path);
 751         two = alloc_filespec(path);
 752         diff_queue(&diff_queued_diff, one, two);
 753 }