diff-tree.c

   1 #include <ctype.h>
   2 #include "cache.h"
   3 #include "diff.h"
   4 #include "commit.h"
   5
   6 static int show_root_diff = 0;
   7 static int verbose_header = 0;
   8 static int ignore_merges = 1;
   9 static int recursive = 0;
  10 static int show_tree_entry_in_recursive = 0;
  11 static int read_stdin = 0;
  12
  13 static struct diff_options diff_options;
  14
  15 static const char *header = NULL;
  16 static const char *header_prefix = "";
  17 static enum cmit_fmt commit_format = CMIT_FMT_RAW;
  18
  19 // What paths are we interested in?
  20 static int nr_paths = 0;
  21 static const char **paths = NULL;
  22 static int *pathlens = NULL;
  23
  24 static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base);
  25
  26 static void update_tree_entry(void **bufp, unsigned long *sizep)
  27 {
  28         void *buf = *bufp;
  29         unsigned long size = *sizep;
  30         int len = strlen(buf) + 1 + 20;
  31
  32         if (size < len)
  33                 die("corrupt tree file");
  34         *bufp = buf + len;
  35         *sizep = size - len;
  36 }
  37
  38 static const unsigned char *extract(void *tree, unsigned long size, const char **pathp, unsigned int *modep)
  39 {
  40         int len = strlen(tree)+1;
  41         const unsigned char *sha1 = tree + len;
  42         const char *path = strchr(tree, ' ');
  43         unsigned int mode;
  44
  45         if (!path || size < len + 20 || sscanf(tree, "%o", &mode) != 1)
  46                 die("corrupt tree file");
  47         *pathp = path+1;
  48         *modep = DIFF_FILE_CANON_MODE(mode);
  49         return sha1;
  50 }
  51
  52 static char *malloc_base(const char *base, const char *path, int pathlen)
  53 {
  54         int baselen = strlen(base);
  55         char *newbase = xmalloc(baselen + pathlen + 2);
  56         memcpy(newbase, base, baselen);
  57         memcpy(newbase + baselen, path, pathlen);
  58         memcpy(newbase + baselen + pathlen, "/", 2);
  59         return newbase;
  60 }
  61
  62 static void show_file(const char *prefix, void *tree, unsigned long size, const char *base);
  63 static void show_tree(const char *prefix, void *tree, unsigned long size, const char *base);
  64
  65 /* A file entry went away or appeared */
  66 static void show_file(const char *prefix, void *tree, unsigned long size, const char *base)
  67 {
  68         unsigned mode;
  69         const char *path;
  70         const unsigned char *sha1 = extract(tree, size, &path, &mode);
  71
  72         if (recursive && S_ISDIR(mode)) {
  73                 char type[20];
  74                 unsigned long size;
  75                 char *newbase = malloc_base(base, path, strlen(path));
  76                 void *tree;
  77
  78                 tree = read_sha1_file(sha1, type, &size);
  79                 if (!tree || strcmp(type, "tree"))
  80                         die("corrupt tree sha %s", sha1_to_hex(sha1));
  81
  82                 show_tree(prefix, tree, size, newbase);
  83
  84                 free(tree);
  85                 free(newbase);
  86                 return;
  87         }
  88
  89         diff_addremove(&diff_options, prefix[0], mode, sha1, base, path);
  90 }
  91
  92 static int compare_tree_entry(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
  93 {
  94         unsigned mode1, mode2;
  95         const char *path1, *path2;
  96         const unsigned char *sha1, *sha2;
  97         int cmp, pathlen1, pathlen2;
  98
  99         sha1 = extract(tree1, size1, &path1, &mode1);
 100         sha2 = extract(tree2, size2, &path2, &mode2);
 101
 102         pathlen1 = strlen(path1);
 103         pathlen2 = strlen(path2);
 104         cmp = base_name_compare(path1, pathlen1, mode1, path2, pathlen2, mode2);
 105         if (cmp < 0) {
 106                 show_file("-", tree1, size1, base);
 107                 return -1;
 108         }
 109         if (cmp > 0) {
 110                 show_file("+", tree2, size2, base);
 111                 return 1;
 112         }
 113         if (!diff_options.find_copies_harder &&
 114             !memcmp(sha1, sha2, 20) && mode1 == mode2)
 115                 return 0;
 116
 117         /*
 118          * If the filemode has changed to/from a directory from/to a regular
 119          * file, we need to consider it a remove and an add.
 120          */
 121         if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
 122                 show_file("-", tree1, size1, base);
 123                 show_file("+", tree2, size2, base);
 124                 return 0;
 125         }
 126
 127         if (recursive && S_ISDIR(mode1)) {
 128                 int retval;
 129                 char *newbase = malloc_base(base, path1, pathlen1);
 130                 if (show_tree_entry_in_recursive)
 131                         diff_change(&diff_options, mode1, mode2,
 132                                     sha1, sha2, base, path1);
 133                 retval = diff_tree_sha1(sha1, sha2, newbase);
 134                 free(newbase);
 135                 return retval;
 136         }
 137
 138         diff_change(&diff_options, mode1, mode2, sha1, sha2, base, path1);
 139         return 0;
 140 }
 141
 142 static int interesting(void *tree, unsigned long size, const char *base)
 143 {
 144         const char *path;
 145         unsigned mode;
 146         int i;
 147         int baselen, pathlen;
 148
 149         if (!nr_paths)
 150                 return 1;
 151
 152         (void)extract(tree, size, &path, &mode);
 153
 154         pathlen = strlen(path);
 155         baselen = strlen(base);
 156
 157         for (i=0; i < nr_paths; i++) {
 158                 const char *match = paths[i];
 159                 int matchlen = pathlens[i];
 160
 161                 if (baselen >= matchlen) {
 162                         /* If it doesn't match, move along... */
 163                         if (strncmp(base, match, matchlen))
 164                                 continue;
 165
 166                         /* The base is a subdirectory of a path which was specified. */
 167                         return 1;
 168                 }
 169
 170                 /* Does the base match? */
 171                 if (strncmp(base, match, baselen))
 172                         continue;
 173
 174                 match += baselen;
 175                 matchlen -= baselen;
 176
 177                 if (pathlen > matchlen)
 178                         continue;
 179
 180                 if (matchlen > pathlen) {
 181                         if (match[pathlen] != '/')
 182                                 continue;
 183                         if (!S_ISDIR(mode))
 184                                 continue;
 185                 }
 186
 187                 if (strncmp(path, match, pathlen))
 188                         continue;
 189
 190                 return 1;
 191         }
 192         return 0; /* No matches */
 193 }
 194
 195 /* A whole sub-tree went away or appeared */
 196 static void show_tree(const char *prefix, void *tree, unsigned long size, const char *base)
 197 {
 198         while (size) {
 199                 if (interesting(tree, size, base))
 200                         show_file(prefix, tree, size, base);
 201                 update_tree_entry(&tree, &size);
 202         }
 203 }
 204
 205 static int diff_tree(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
 206 {
 207         while (size1 | size2) {
 208                 if (nr_paths && size1 && !interesting(tree1, size1, base)) {
 209                         update_tree_entry(&tree1, &size1);
 210                         continue;
 211                 }
 212                 if (nr_paths && size2 && !interesting(tree2, size2, base)) {
 213                         update_tree_entry(&tree2, &size2);
 214                         continue;
 215                 }
 216                 if (!size1) {
 217                         show_file("+", tree2, size2, base);
 218                         update_tree_entry(&tree2, &size2);
 219                         continue;
 220                 }
 221                 if (!size2) {
 222                         show_file("-", tree1, size1, base);
 223                         update_tree_entry(&tree1, &size1);
 224                         continue;
 225                 }
 226                 switch (compare_tree_entry(tree1, size1, tree2, size2, base)) {
 227                 case -1:
 228                         update_tree_entry(&tree1, &size1);
 229                         continue;
 230                 case 0:
 231                         update_tree_entry(&tree1, &size1);
 232                         /* Fallthrough */
 233                 case 1:
 234                         update_tree_entry(&tree2, &size2);
 235                         continue;
 236                 }
 237                 die("git-diff-tree: internal error");
 238         }
 239         return 0;
 240 }
 241
 242 static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base)
 243 {
 244         void *tree1, *tree2;
 245         unsigned long size1, size2;
 246         int retval;
 247
 248         tree1 = read_object_with_reference(old, "tree", &size1, NULL);
 249         if (!tree1)
 250                 die("unable to read source tree (%s)", sha1_to_hex(old));
 251         tree2 = read_object_with_reference(new, "tree", &size2, NULL);
 252         if (!tree2)
 253                 die("unable to read destination tree (%s)", sha1_to_hex(new));
 254         retval = diff_tree(tree1, size1, tree2, size2, base);
 255         free(tree1);
 256         free(tree2);
 257         return retval;
 258 }
 259
 260 static void call_diff_setup_done(void)
 261 {
 262         diff_setup_done(&diff_options);
 263 }
 264
 265 static int call_diff_flush(void)
 266 {
 267         diffcore_std(&diff_options);
 268         if (diff_queue_is_empty()) {
 269                 int saved_fmt = diff_options.output_format;
 270                 diff_options.output_format = DIFF_FORMAT_NO_OUTPUT;
 271                 diff_flush(&diff_options);
 272                 diff_options.output_format = saved_fmt;
 273                 return 0;
 274         }
 275         if (header) {
 276                 printf("%s%c", header, diff_options.line_termination);
 277                 header = NULL;
 278         }
 279         diff_flush(&diff_options);
 280         return 1;
 281 }
 282
 283 static int diff_tree_sha1_top(const unsigned char *old,
 284                               const unsigned char *new, const char *base)
 285 {
 286         int ret;
 287
 288         call_diff_setup_done();
 289         ret = diff_tree_sha1(old, new, base);
 290         call_diff_flush();
 291         return ret;
 292 }
 293
 294 static int diff_root_tree(const unsigned char *new, const char *base)
 295 {
 296         int retval;
 297         void *tree;
 298         unsigned long size;
 299
 300         call_diff_setup_done();
 301         tree = read_object_with_reference(new, "tree", &size, NULL);
 302         if (!tree)
 303                 die("unable to read root tree (%s)", sha1_to_hex(new));
 304         retval = diff_tree("", 0, tree, size, base);
 305         free(tree);
 306         call_diff_flush();
 307         return retval;
 308 }
 309
 310 static const char *generate_header(const char *commit, const char *parent, const char *msg, unsigned long len)
 311 {
 312         static char this_header[16384];
 313         int offset;
 314
 315         if (!verbose_header)
 316                 return commit;
 317
 318         offset = sprintf(this_header, "%s%s (from %s)\n", header_prefix, commit, parent);
 319         offset += pretty_print_commit(commit_format, msg, len, this_header + offset, sizeof(this_header) - offset);
 320         return this_header;
 321 }
 322
 323 static int diff_tree_commit(const unsigned char *commit, const char *name)
 324 {
 325         unsigned long size, offset;
 326         char *buf = read_object_with_reference(commit, "commit", &size, NULL);
 327
 328         if (!buf)
 329                 return -1;
 330
 331         if (!name) {
 332                 static char commit_name[60];
 333                 strcpy(commit_name, sha1_to_hex(commit));
 334                 name = commit_name;
 335         }
 336
 337         /* Root commit? */
 338         if (show_root_diff && memcmp(buf + 46, "parent ", 7)) {
 339                 header = generate_header(name, "root", buf, size);
 340                 diff_root_tree(commit, "");
 341         }
 342
 343         /* More than one parent? */
 344         if (ignore_merges) {
 345                 if (!memcmp(buf + 46 + 48, "parent ", 7))
 346                         return 0;
 347         }
 348
 349         offset = 46;
 350         while (offset + 48 < size && !memcmp(buf + offset, "parent ", 7)) {
 351                 unsigned char parent[20];
 352                 if (get_sha1_hex(buf + offset + 7, parent))
 353                         return -1;
 354                 header = generate_header(name, sha1_to_hex(parent), buf, size);
 355                 diff_tree_sha1_top(parent, commit, "");
 356                 if (!header && verbose_header) {
 357                         header_prefix = "\ndiff-tree ";
 358                         /*
 359                          * Don't print multiple merge entries if we
 360                          * don't print the diffs.
 361                          */
 362                 }
 363                 offset += 48;
 364         }
 365         free(buf);
 366         return 0;
 367 }
 368
 369 static int diff_tree_stdin(char *line)
 370 {
 371         int len = strlen(line);
 372         unsigned char commit[20], parent[20];
 373         static char this_header[1000];
 374
 375         if (!len || line[len-1] != '\n')
 376                 return -1;
 377         line[len-1] = 0;
 378         if (get_sha1_hex(line, commit))
 379                 return -1;
 380         if (isspace(line[40]) && !get_sha1_hex(line+41, parent)) {
 381                 line[40] = 0;
 382                 line[81] = 0;
 383                 sprintf(this_header, "%s (from %s)\n", line, line+41);
 384                 header = this_header;
 385                 return diff_tree_sha1_top(parent, commit, "");
 386         }
 387         line[40] = 0;
 388         return diff_tree_commit(commit, line);
 389 }
 390
 391 static int count_paths(const char **paths)
 392 {
 393         int i = 0;
 394         while (*paths++)
 395                 i++;
 396         return i;
 397 }
 398
 399 static const char diff_tree_usage[] =
 400 "git-diff-tree [--stdin] [-m] [-s] [-v] [--pretty] [-t] "
 401 "[<common diff options>] <tree-ish> <tree-ish>"
 402 COMMON_DIFF_OPTIONS_HELP;
 403
 404 int main(int argc, const char **argv)
 405 {
 406         int nr_sha1;
 407         char line[1000];
 408         unsigned char sha1[2][20];
 409         const char *prefix = setup_git_directory();
 410
 411         nr_sha1 = 0;
 412         diff_setup(&diff_options);
 413
 414         for (;;) {
 415                 int diff_opt_cnt;
 416                 const char *arg;
 417
 418                 argv++;
 419                 argc--;
 420                 arg = *argv;
 421                 if (!arg)
 422                         break;
 423
 424                 if (*arg != '-') {
 425                         if (nr_sha1 < 2 && !get_sha1(arg, sha1[nr_sha1])) {
 426                                 nr_sha1++;
 427                                 continue;
 428                         }
 429                         break;
 430                 }
 431
 432                 diff_opt_cnt = diff_opt_parse(&diff_options, argv, argc);
 433                 if (diff_opt_cnt < 0)
 434                         usage(diff_tree_usage);
 435                 else if (diff_opt_cnt) {
 436                         argv += diff_opt_cnt - 1;
 437                         argc -= diff_opt_cnt - 1;
 438                         continue;
 439                 }
 440
 441
 442                 if (!strcmp(arg, "--")) {
 443                         argv++;
 444                         argc--;
 445                         break;
 446                 }
 447                 if (!strcmp(arg, "-r")) {
 448                         recursive = 1;
 449                         continue;
 450                 }
 451                 if (!strcmp(arg, "-t")) {
 452                         recursive = show_tree_entry_in_recursive = 1;
 453                         continue;
 454                 }
 455                 if (!strcmp(arg, "-m")) {
 456                         ignore_merges = 0;
 457                         continue;
 458                 }
 459                 if (!strcmp(arg, "-v")) {
 460                         verbose_header = 1;
 461                         header_prefix = "diff-tree ";
 462                         continue;
 463                 }
 464                 if (!strncmp(arg, "--pretty", 8)) {
 465                         verbose_header = 1;
 466                         header_prefix = "diff-tree ";
 467                         commit_format = get_commit_format(arg+8);
 468                         continue;
 469                 }
 470                 if (!strcmp(arg, "--stdin")) {
 471                         read_stdin = 1;
 472                         continue;
 473                 }
 474                 if (!strcmp(arg, "--root")) {
 475                         show_root_diff = 1;
 476                         continue;
 477                 }
 478                 usage(diff_tree_usage);
 479         }
 480         if (diff_options.output_format == DIFF_FORMAT_PATCH)
 481                 recursive = 1;
 482
 483         paths = get_pathspec(prefix, argv);
 484         if (paths) {
 485                 int i;
 486
 487                 nr_paths = count_paths(paths);
 488                 pathlens = xmalloc(nr_paths * sizeof(int));
 489                 for (i=0; i<nr_paths; i++)
 490                         pathlens[i] = strlen(paths[i]);
 491         }
 492
 493         switch (nr_sha1) {
 494         case 0:
 495                 if (!read_stdin)
 496                         usage(diff_tree_usage);
 497                 break;
 498         case 1:
 499                 diff_tree_commit(sha1[0], NULL);
 500                 break;
 501         case 2:
 502                 diff_tree_sha1_top(sha1[0], sha1[1], "");
 503                 break;
 504         }
 505
 506         if (!read_stdin)
 507                 return 0;
 508
 509         if (diff_options.detect_rename)
 510                 diff_options.setup |= (DIFF_SETUP_USE_SIZE_CACHE |
 511                                        DIFF_SETUP_USE_CACHE);
 512         while (fgets(line, sizeof(line), stdin))
 513                 diff_tree_stdin(line);
 514
 515         return 0;
 516 }