diff-tree.c

   1 #include <ctype.h>
   2 #include "cache.h"
   3 #include "diff.h"
   4
   5 static int show_root_diff = 0;
   6 static int verbose_header = 0;
   7 static int ignore_merges = 1;
   8 static int recursive = 0;
   9 static int show_tree_entry_in_recursive = 0;
  10 static int read_stdin = 0;
  11 static int diff_output_format = DIFF_FORMAT_HUMAN;
  12 static int detect_rename = 0;
  13 static int diff_setup_opt = 0;
  14 static int diff_score_opt = 0;
  15 static const char *pickaxe = NULL;
  16 static int pickaxe_opts = 0;
  17 static int diff_break_opt = -1;
  18 static const char *header = NULL;
  19 static const char *header_prefix = "";
  20
  21 // What paths are we interested in?
  22 static int nr_paths = 0;
  23 static const char **paths = NULL;
  24 static int *pathlens = NULL;
  25
  26 static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base);
  27
  28 static void update_tree_entry(void **bufp, unsigned long *sizep)
  29 {
  30         void *buf = *bufp;
  31         unsigned long size = *sizep;
  32         int len = strlen(buf) + 1 + 20;
  33
  34         if (size < len)
  35                 die("corrupt tree file");
  36         *bufp = buf + len;
  37         *sizep = size - len;
  38 }
  39
  40 static const unsigned char *extract(void *tree, unsigned long size, const char **pathp, unsigned int *modep)
  41 {
  42         int len = strlen(tree)+1;
  43         const unsigned char *sha1 = tree + len;
  44         const char *path = strchr(tree, ' ');
  45
  46         if (!path || size < len + 20 || sscanf(tree, "%o", modep) != 1)
  47                 die("corrupt tree file");
  48         *pathp = path+1;
  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(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 (!memcmp(sha1, sha2, 20) && mode1 == mode2)
 114                 return 0;
 115
 116         /*
 117          * If the filemode has changed to/from a directory from/to a regular
 118          * file, we need to consider it a remove and an add.
 119          */
 120         if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
 121                 show_file("-", tree1, size1, base);
 122                 show_file("+", tree2, size2, base);
 123                 return 0;
 124         }
 125
 126         if (recursive && S_ISDIR(mode1)) {
 127                 int retval;
 128                 char *newbase = malloc_base(base, path1, pathlen1);
 129                 if (show_tree_entry_in_recursive)
 130                         diff_change(mode1, mode2, sha1, sha2, base, path1);
 131                 retval = diff_tree_sha1(sha1, sha2, newbase);
 132                 free(newbase);
 133                 return retval;
 134         }
 135
 136         diff_change(mode1, mode2, sha1, sha2, base, path1);
 137         return 0;
 138 }
 139
 140 static int interesting(void *tree, unsigned long size, const char *base)
 141 {
 142         const char *path;
 143         unsigned mode;
 144         int i;
 145         int baselen, pathlen;
 146
 147         if (!nr_paths)
 148                 return 1;
 149
 150         (void)extract(tree, size, &path, &mode);
 151
 152         pathlen = strlen(path);
 153         baselen = strlen(base);
 154
 155         for (i=0; i < nr_paths; i++) {
 156                 const char *match = paths[i];
 157                 int matchlen = pathlens[i];
 158
 159                 if (baselen >= matchlen) {
 160                         /* If it doesn't match, move along... */
 161                         if (strncmp(base, match, matchlen))
 162                                 continue;
 163
 164                         /* The base is a subdirectory of a path which was specified. */
 165                         return 1;
 166                 }
 167
 168                 /* Does the base match? */
 169                 if (strncmp(base, match, baselen))
 170                         continue;
 171
 172                 match += baselen;
 173                 matchlen -= baselen;
 174
 175                 if (pathlen > matchlen)
 176                         continue;
 177
 178                 if (matchlen > pathlen) {
 179                         if (match[pathlen] != '/')
 180                                 continue;
 181                         if (!S_ISDIR(mode))
 182                                 continue;
 183                 }
 184
 185                 if (strncmp(path, match, pathlen))
 186                         continue;
 187
 188                 return 1;
 189         }
 190         return 0; /* No matches */
 191 }
 192
 193 /* A whole sub-tree went away or appeared */
 194 static void show_tree(const char *prefix, void *tree, unsigned long size, const char *base)
 195 {
 196         while (size) {
 197                 if (interesting(tree, size, base))
 198                         show_file(prefix, tree, size, base);
 199                 update_tree_entry(&tree, &size);
 200         }
 201 }
 202
 203 static int diff_tree(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
 204 {
 205         while (size1 | size2) {
 206                 if (nr_paths && size1 && !interesting(tree1, size1, base)) {
 207                         update_tree_entry(&tree1, &size1);
 208                         continue;
 209                 }
 210                 if (nr_paths && size2 && !interesting(tree2, size2, base)) {
 211                         update_tree_entry(&tree2, &size2);
 212                         continue;
 213                 }
 214                 if (!size1) {
 215                         show_file("+", tree2, size2, base);
 216                         update_tree_entry(&tree2, &size2);
 217                         continue;
 218                 }
 219                 if (!size2) {
 220                         show_file("-", tree1, size1, base);
 221                         update_tree_entry(&tree1, &size1);
 222                         continue;
 223                 }
 224                 switch (compare_tree_entry(tree1, size1, tree2, size2, base)) {
 225                 case -1:
 226                         update_tree_entry(&tree1, &size1);
 227                         continue;
 228                 case 0:
 229                         update_tree_entry(&tree1, &size1);
 230                         /* Fallthrough */
 231                 case 1:
 232                         update_tree_entry(&tree2, &size2);
 233                         continue;
 234                 }
 235                 die("git-diff-tree: internal error");
 236         }
 237         return 0;
 238 }
 239
 240 static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base)
 241 {
 242         void *tree1, *tree2;
 243         unsigned long size1, size2;
 244         int retval;
 245
 246         tree1 = read_object_with_reference(old, "tree", &size1, NULL);
 247         if (!tree1)
 248                 die("unable to read source tree (%s)", sha1_to_hex(old));
 249         tree2 = read_object_with_reference(new, "tree", &size2, NULL);
 250         if (!tree2)
 251                 die("unable to read destination tree (%s)", sha1_to_hex(new));
 252         retval = diff_tree(tree1, size1, tree2, size2, base);
 253         free(tree1);
 254         free(tree2);
 255         return retval;
 256 }
 257
 258 static void call_diff_setup(void)
 259 {
 260         diff_setup(diff_setup_opt);
 261 }
 262
 263 static int call_diff_flush(void)
 264 {
 265         diffcore_std(0,
 266                      detect_rename, diff_score_opt,
 267                      pickaxe, pickaxe_opts,
 268                      diff_break_opt);
 269         if (diff_queue_is_empty()) {
 270                 diff_flush(DIFF_FORMAT_NO_OUTPUT, 0);
 271                 return 0;
 272         }
 273         if (header) {
 274                 const char *fmt = "%s";
 275                 if (diff_output_format == DIFF_FORMAT_MACHINE)
 276                         fmt = "%s%c";
 277
 278                 printf(fmt, header, 0);
 279                 header = NULL;
 280         }
 281         diff_flush(diff_output_format, 1);
 282         return 1;
 283 }
 284
 285 static int diff_tree_sha1_top(const unsigned char *old,
 286                               const unsigned char *new, const char *base)
 287 {
 288         int ret;
 289
 290         call_diff_setup();
 291         ret = diff_tree_sha1(old, new, base);
 292         call_diff_flush();
 293         return ret;
 294 }
 295
 296 static int diff_root_tree(const unsigned char *new, const char *base)
 297 {
 298         int retval;
 299         void *tree;
 300         unsigned long size;
 301
 302         call_diff_setup();
 303         tree = read_object_with_reference(new, "tree", &size, NULL);
 304         if (!tree)
 305                 die("unable to read root tree (%s)", sha1_to_hex(new));
 306         retval = diff_tree("", 0, tree, size, base);
 307         free(tree);
 308         call_diff_flush();
 309         return retval;
 310 }
 311
 312 static int get_one_line(const char *msg, unsigned long len)
 313 {
 314         int ret = 0;
 315
 316         while (len--) {
 317                 ret++;
 318                 if (*msg++ == '\n')
 319                         break;
 320         }
 321         return ret;
 322 }
 323
 324 static int add_author_info(char *buf, const char *line, int len)
 325 {
 326         char *date;
 327         unsigned int namelen;
 328         unsigned long time;
 329         int tz;
 330
 331         line += strlen("author ");
 332         date = strchr(line, '>');
 333         if (!date)
 334                 return 0;
 335         namelen = ++date - line;
 336         time = strtoul(date, &date, 10);
 337         tz = strtol(date, NULL, 10);
 338
 339         return sprintf(buf, "Author: %.*s\nDate:   %s\n",
 340                 namelen, line,
 341                 show_date(time, tz));
 342 }
 343
 344 static char *generate_header(const char *commit, const char *parent, const char *msg, unsigned long len)
 345 {
 346         static char this_header[16384];
 347         int offset;
 348
 349         offset = sprintf(this_header, "%s%s (from %s)\n", header_prefix, commit, parent);
 350         if (verbose_header) {
 351                 int hdr = 1;
 352
 353                 for (;;) {
 354                         const char *line = msg;
 355                         int linelen = get_one_line(msg, len);
 356
 357                         if (!linelen)
 358                                 break;
 359
 360                         /*
 361                          * We want some slop for indentation and a possible
 362                          * final "...". Thus the "+ 20".
 363                          */
 364                         if (offset + linelen + 20 > sizeof(this_header)) {
 365                                 memcpy(this_header + offset, "    ...\n", 8);
 366                                 offset += 8;
 367                                 break;
 368                         }
 369
 370                         msg += linelen;
 371                         len -= linelen;
 372                         if (linelen == 1)
 373                                 hdr = 0;
 374                         if (hdr) {
 375                                 if (!memcmp(line, "author ", 7))
 376                                         offset += add_author_info(this_header + offset, line, linelen);
 377                                 continue;
 378                         }
 379                         memset(this_header + offset, ' ', 4);
 380                         memcpy(this_header + offset + 4, line, linelen);
 381                         offset += linelen + 4;
 382                 }
 383                 /* Make sure there is an EOLN */
 384                 if (this_header[offset-1] != '\n')
 385                         this_header[offset++] = '\n';
 386                 /* Add _another_ EOLN if we are doing diff output */
 387                 this_header[offset++] = '\n';
 388                 this_header[offset] = 0;
 389         }
 390
 391         return this_header;
 392 }
 393
 394 static int diff_tree_commit(const unsigned char *commit, const char *name)
 395 {
 396         unsigned long size, offset;
 397         char *buf = read_object_with_reference(commit, "commit", &size, NULL);
 398
 399         if (!buf)
 400                 return -1;
 401
 402         if (!name) {
 403                 static char commit_name[60];
 404                 strcpy(commit_name, sha1_to_hex(commit));
 405                 name = commit_name;
 406         }
 407
 408         /* Root commit? */
 409         if (show_root_diff && memcmp(buf + 46, "parent ", 7)) {
 410                 header = generate_header(name, "root", buf, size);
 411                 diff_root_tree(commit, "");
 412         }
 413
 414         /* More than one parent? */
 415         if (ignore_merges) {
 416                 if (!memcmp(buf + 46 + 48, "parent ", 7))
 417                         return 0;
 418         }
 419
 420         offset = 46;
 421         while (offset + 48 < size && !memcmp(buf + offset, "parent ", 7)) {
 422                 unsigned char parent[20];
 423                 if (get_sha1_hex(buf + offset + 7, parent))
 424                         return -1;
 425                 header = generate_header(name, sha1_to_hex(parent), buf, size);
 426                 diff_tree_sha1_top(parent, commit, "");
 427                 if (!header && verbose_header) {
 428                         header_prefix = "\ndiff-tree ";
 429                         /*
 430                          * Don't print multiple merge entries if we
 431                          * don't print the diffs.
 432                          */
 433                 }
 434                 offset += 48;
 435         }
 436         return 0;
 437 }
 438
 439 static int diff_tree_stdin(char *line)
 440 {
 441         int len = strlen(line);
 442         unsigned char commit[20], parent[20];
 443         static char this_header[1000];
 444
 445         if (!len || line[len-1] != '\n')
 446                 return -1;
 447         line[len-1] = 0;
 448         if (get_sha1_hex(line, commit))
 449                 return -1;
 450         if (isspace(line[40]) && !get_sha1_hex(line+41, parent)) {
 451                 line[40] = 0;
 452                 line[81] = 0;
 453                 sprintf(this_header, "%s (from %s)\n", line, line+41);
 454                 header = this_header;
 455                 return diff_tree_sha1_top(parent, commit, "");
 456         }
 457         line[40] = 0;
 458         return diff_tree_commit(commit, line);
 459 }
 460
 461 static char *diff_tree_usage =
 462 "git-diff-tree [-p] [-r] [-z] [--stdin] [-M] [-C] [-R] [-S<string>] [-m] [-s] [-v] [-t] <tree-ish> <tree-ish>";
 463
 464 int main(int argc, const char **argv)
 465 {
 466         int nr_sha1;
 467         char line[1000];
 468         unsigned char sha1[2][20];
 469
 470         nr_sha1 = 0;
 471         for (;;) {
 472                 const char *arg;
 473
 474                 argv++;
 475                 argc--;
 476                 arg = *argv;
 477                 if (!arg)
 478                         break;
 479
 480                 if (*arg != '-') {
 481                         if (nr_sha1 < 2 && !get_sha1(arg, sha1[nr_sha1])) {
 482                                 nr_sha1++;
 483                                 continue;
 484                         }
 485                         break;
 486                 }
 487
 488                 if (!strcmp(arg, "--")) {
 489                         argv++;
 490                         argc--;
 491                         break;
 492                 }
 493                 if (!strcmp(arg, "-r")) {
 494                         recursive = 1;
 495                         continue;
 496                 }
 497                 if (!strcmp(arg, "-t")) {
 498                         recursive = show_tree_entry_in_recursive = 1;
 499                         continue;
 500                 }
 501                 if (!strcmp(arg, "-R")) {
 502                         diff_setup_opt |= DIFF_SETUP_REVERSE;
 503                         continue;
 504                 }
 505                 if (!strcmp(arg, "-p")) {
 506                         diff_output_format = DIFF_FORMAT_PATCH;
 507                         recursive = 1;
 508                         continue;
 509                 }
 510                 if (!strncmp(arg, "-S", 2)) {
 511                         pickaxe = arg + 2;
 512                         continue;
 513                 }
 514                 if (!strcmp(arg, "--pickaxe-all")) {
 515                         pickaxe_opts = DIFF_PICKAXE_ALL;
 516                         continue;
 517                 }
 518                 if (!strncmp(arg, "-M", 2)) {
 519                         detect_rename = DIFF_DETECT_RENAME;
 520                         diff_score_opt = diff_scoreopt_parse(arg);
 521                         continue;
 522                 }
 523                 if (!strncmp(arg, "-C", 2)) {
 524                         detect_rename = DIFF_DETECT_COPY;
 525                         diff_score_opt = diff_scoreopt_parse(arg);
 526                         continue;
 527                 }
 528                 if (!strncmp(arg, "-B", 2)) {
 529                         diff_break_opt = diff_scoreopt_parse(arg);
 530                         continue;
 531                 }
 532                 if (!strcmp(arg, "-z")) {
 533                         diff_output_format = DIFF_FORMAT_MACHINE;
 534                         continue;
 535                 }
 536                 if (!strcmp(arg, "-m")) {
 537                         ignore_merges = 0;
 538                         continue;
 539                 }
 540                 if (!strcmp(arg, "-s")) {
 541                         diff_output_format = DIFF_FORMAT_NO_OUTPUT;
 542                         continue;
 543                 }
 544                 if (!strcmp(arg, "-v")) {
 545                         verbose_header = 1;
 546                         header_prefix = "diff-tree ";
 547                         continue;
 548                 }
 549                 if (!strcmp(arg, "--stdin")) {
 550                         read_stdin = 1;
 551                         continue;
 552                 }
 553                 if (!strcmp(arg, "--root")) {
 554                         show_root_diff = 1;
 555                         continue;
 556                 }
 557                 usage(diff_tree_usage);
 558         }
 559
 560         if (argc > 0) {
 561                 int i;
 562
 563                 paths = argv;
 564                 nr_paths = argc;
 565                 pathlens = xmalloc(nr_paths * sizeof(int));
 566                 for (i=0; i<nr_paths; i++)
 567                         pathlens[i] = strlen(paths[i]);
 568         }
 569
 570         switch (nr_sha1) {
 571         case 0:
 572                 if (!read_stdin)
 573                         usage(diff_tree_usage);
 574                 break;
 575         case 1:
 576                 diff_tree_commit(sha1[0], NULL);
 577                 break;
 578         case 2:
 579                 diff_tree_sha1_top(sha1[0], sha1[1], "");
 580                 break;
 581         }
 582
 583         if (!read_stdin)
 584                 return 0;
 585
 586         if (detect_rename)
 587                 diff_setup_opt |= (DIFF_SETUP_USE_SIZE_CACHE |
 588                                    DIFF_SETUP_USE_CACHE);
 589         while (fgets(line, sizeof(line), stdin))
 590                 diff_tree_stdin(line);
 591
 592         return 0;
 593 }