diff-tree.c

   1 #include <ctype.h>
   2 #include "cache.h"
   3 #include "diff.h"
   4
   5 static int silent = 0;
   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 read_stdin = 0;
  11 static int line_termination = '\n';
  12 static int generate_patch = 0;
  13 static int detect_rename = 0;
  14 static int reverse_diff = 0;
  15 static int diff_score_opt = 0;
  16 static const char *pickaxe = NULL;
  17 static const char *header = NULL;
  18 static const char *header_prefix = "";
  19
  20 // What paths are we interested in?
  21 static int nr_paths = 0;
  22 static char **paths = NULL;
  23 static int *pathlens = NULL;
  24
  25 static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base);
  26
  27 static void update_tree_entry(void **bufp, unsigned long *sizep)
  28 {
  29         void *buf = *bufp;
  30         unsigned long size = *sizep;
  31         int len = strlen(buf) + 1 + 20;
  32
  33         if (size < len)
  34                 die("corrupt tree file");
  35         *bufp = buf + len;
  36         *sizep = size - len;
  37 }
  38
  39 static const unsigned char *extract(void *tree, unsigned long size, const char **pathp, unsigned int *modep)
  40 {
  41         int len = strlen(tree)+1;
  42         const unsigned char *sha1 = tree + len;
  43         const char *path = strchr(tree, ' ');
  44
  45         if (!path || size < len + 20 || sscanf(tree, "%o", modep) != 1)
  46                 die("corrupt tree file");
  47         *pathp = path+1;
  48         return sha1;
  49 }
  50
  51 static char *malloc_base(const char *base, const char *path, int pathlen)
  52 {
  53         int baselen = strlen(base);
  54         char *newbase = xmalloc(baselen + pathlen + 2);
  55         memcpy(newbase, base, baselen);
  56         memcpy(newbase + baselen, path, pathlen);
  57         memcpy(newbase + baselen + pathlen, "/", 2);
  58         return newbase;
  59 }
  60
  61 static void show_file(const char *prefix, void *tree, unsigned long size, const char *base);
  62 static void show_tree(const char *prefix, void *tree, unsigned long size, const char *base);
  63
  64 /* A file entry went away or appeared */
  65 static void show_file(const char *prefix, void *tree, unsigned long size, const char *base)
  66 {
  67         unsigned mode;
  68         const char *path;
  69         const unsigned char *sha1 = extract(tree, size, &path, &mode);
  70
  71         if (header) {
  72                 printf("%s", header);
  73                 header = NULL;
  74         }
  75
  76         if (silent)
  77                 return;
  78
  79         if (recursive && S_ISDIR(mode)) {
  80                 char type[20];
  81                 unsigned long size;
  82                 char *newbase = malloc_base(base, path, strlen(path));
  83                 void *tree;
  84
  85                 tree = read_sha1_file(sha1, type, &size);
  86                 if (!tree || strcmp(type, "tree"))
  87                         die("corrupt tree sha %s", sha1_to_hex(sha1));
  88
  89                 show_tree(prefix, tree, size, newbase);
  90
  91                 free(tree);
  92                 free(newbase);
  93                 return;
  94         }
  95
  96         diff_addremove(prefix[0], mode, sha1, base, path);
  97 }
  98
  99 static int compare_tree_entry(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
 100 {
 101         unsigned mode1, mode2;
 102         const char *path1, *path2;
 103         const unsigned char *sha1, *sha2;
 104         int cmp, pathlen1, pathlen2;
 105
 106         sha1 = extract(tree1, size1, &path1, &mode1);
 107         sha2 = extract(tree2, size2, &path2, &mode2);
 108
 109         pathlen1 = strlen(path1);
 110         pathlen2 = strlen(path2);
 111         cmp = base_name_compare(path1, pathlen1, mode1, path2, pathlen2, mode2);
 112         if (cmp < 0) {
 113                 show_file("-", tree1, size1, base);
 114                 return -1;
 115         }
 116         if (cmp > 0) {
 117                 show_file("+", tree2, size2, base);
 118                 return 1;
 119         }
 120         if (!memcmp(sha1, sha2, 20) && mode1 == mode2)
 121                 return 0;
 122
 123         /*
 124          * If the filemode has changed to/from a directory from/to a regular
 125          * file, we need to consider it a remove and an add.
 126          */
 127         if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
 128                 show_file("-", tree1, size1, base);
 129                 show_file("+", tree2, size2, base);
 130                 return 0;
 131         }
 132
 133         if (recursive && S_ISDIR(mode1)) {
 134                 int retval;
 135                 char *newbase = malloc_base(base, path1, pathlen1);
 136                 retval = diff_tree_sha1(sha1, sha2, newbase);
 137                 free(newbase);
 138                 return retval;
 139         }
 140
 141         if (header) {
 142                 printf("%s", header);
 143                 header = NULL;
 144         }
 145         if (silent)
 146                 return 0;
 147
 148         diff_change(mode1, mode2, sha1, sha2, base, path1);
 149         return 0;
 150 }
 151
 152 static int interesting(void *tree, unsigned long size, const char *base)
 153 {
 154         const char *path;
 155         unsigned mode;
 156         int i;
 157         int baselen, pathlen;
 158
 159         if (!nr_paths)
 160                 return 1;
 161
 162         (void)extract(tree, size, &path, &mode);
 163
 164         pathlen = strlen(path);
 165         baselen = strlen(base);
 166
 167         for (i=0; i < nr_paths; i++) {
 168                 const char *match = paths[i];
 169                 int matchlen = pathlens[i];
 170
 171                 if (baselen >= matchlen) {
 172                         /* If it doesn't match, move along... */
 173                         if (strncmp(base, match, matchlen))
 174                                 continue;
 175
 176                         /* The base is a subdirectory of a path which was specified. */
 177                         return 1;
 178                 }
 179
 180                 /* Does the base match? */
 181                 if (strncmp(base, match, baselen))
 182                         continue;
 183
 184                 match += baselen;
 185                 matchlen -= baselen;
 186
 187                 if (pathlen > matchlen)
 188                         continue;
 189
 190                 if (matchlen > pathlen) {
 191                         if (match[pathlen] != '/')
 192                                 continue;
 193                         if (!S_ISDIR(mode))
 194                                 continue;
 195                 }
 196
 197                 if (strncmp(path, match, pathlen))
 198                         continue;
 199
 200                 return 1;
 201         }
 202         return 0; /* No matches */
 203 }
 204
 205 /* A whole sub-tree went away or appeared */
 206 static void show_tree(const char *prefix, void *tree, unsigned long size, const char *base)
 207 {
 208         while (size) {
 209                 if (interesting(tree, size, base))
 210                         show_file(prefix, tree, size, base);
 211                 update_tree_entry(&tree, &size);
 212         }
 213 }
 214
 215 static int diff_tree(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
 216 {
 217         while (size1 | size2) {
 218                 if (nr_paths && size1 && !interesting(tree1, size1, base)) {
 219                         update_tree_entry(&tree1, &size1);
 220                         continue;
 221                 }
 222                 if (nr_paths && size2 && !interesting(tree2, size2, base)) {
 223                         update_tree_entry(&tree2, &size2);
 224                         continue;
 225                 }
 226                 if (!size1) {
 227                         show_file("+", tree2, size2, base);
 228                         update_tree_entry(&tree2, &size2);
 229                         continue;
 230                 }
 231                 if (!size2) {
 232                         show_file("-", tree1, size1, base);
 233                         update_tree_entry(&tree1, &size1);
 234                         continue;
 235                 }
 236                 switch (compare_tree_entry(tree1, size1, tree2, size2, base)) {
 237                 case -1:
 238                         update_tree_entry(&tree1, &size1);
 239                         continue;
 240                 case 0:
 241                         update_tree_entry(&tree1, &size1);
 242                         /* Fallthrough */
 243                 case 1:
 244                         update_tree_entry(&tree2, &size2);
 245                         continue;
 246                 }
 247                 die("git-diff-tree: internal error");
 248         }
 249         return 0;
 250 }
 251
 252 static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base)
 253 {
 254         void *tree1, *tree2;
 255         unsigned long size1, size2;
 256         int retval;
 257
 258         tree1 = read_object_with_reference(old, "tree", &size1, NULL);
 259         if (!tree1)
 260                 die("unable to read source tree (%s)", sha1_to_hex(old));
 261         tree2 = read_object_with_reference(new, "tree", &size2, NULL);
 262         if (!tree2)
 263                 die("unable to read destination tree (%s)", sha1_to_hex(new));
 264         retval = diff_tree(tree1, size1, tree2, size2, base);
 265         free(tree1);
 266         free(tree2);
 267         return retval;
 268 }
 269
 270 static int diff_tree_sha1_top(const unsigned char *old,
 271                               const unsigned char *new, const char *base)
 272 {
 273         int ret;
 274
 275         diff_setup(detect_rename, diff_score_opt, pickaxe,
 276                    reverse_diff, (generate_patch ? -1 : line_termination),
 277                    NULL, 0);
 278         ret = diff_tree_sha1(old, new, base);
 279         diff_flush();
 280         return ret;
 281 }
 282
 283 static int diff_root_tree(const unsigned char *new, const char *base)
 284 {
 285         int retval;
 286         void *tree;
 287         unsigned long size;
 288
 289         diff_setup(detect_rename, diff_score_opt, pickaxe,
 290                    reverse_diff, (generate_patch ? -1 : line_termination),
 291                    NULL, 0);
 292         tree = read_object_with_reference(new, "tree", &size, NULL);
 293         if (!tree)
 294                 die("unable to read root tree (%s)", sha1_to_hex(new));
 295         retval = diff_tree("", 0, tree, size, base);
 296         free(tree);
 297         diff_flush();
 298         return retval;
 299 }
 300
 301 static int get_one_line(const char *msg, unsigned long len)
 302 {
 303         int ret = 0;
 304
 305         while (len--) {
 306                 ret++;
 307                 if (*msg++ == '\n')
 308                         break;
 309         }
 310         return ret;
 311 }
 312
 313 static int add_author_info(char *buf, const char *line, int len)
 314 {
 315         char *date;
 316         unsigned int namelen;
 317         unsigned long time;
 318         int tz;
 319
 320         line += strlen("author ");
 321         date = strchr(line, '>');
 322         if (!date)
 323                 return 0;
 324         namelen = ++date - line;
 325         time = strtoul(date, &date, 10);
 326         tz = strtol(date, NULL, 10);
 327
 328         return sprintf(buf, "Author: %.*s\nDate:   %s\n",
 329                 namelen, line,
 330                 show_date(time, tz));
 331 }
 332
 333 static char *generate_header(const char *commit, const char *parent, const char *msg, unsigned long len)
 334 {
 335         static char this_header[16384];
 336         int offset;
 337
 338         offset = sprintf(this_header, "%s%s (from %s)\n", header_prefix, commit, parent);
 339         if (verbose_header) {
 340                 int hdr = 1;
 341
 342                 for (;;) {
 343                         const char *line = msg;
 344                         int linelen = get_one_line(msg, len);
 345
 346                         if (!linelen)
 347                                 break;
 348
 349                         /*
 350                          * We want some slop for indentation and a possible
 351                          * final "...". Thus the "+ 20".
 352                          */
 353                         if (offset + linelen + 20 > sizeof(this_header)) {
 354                                 memcpy(this_header + offset, "    ...\n", 8);
 355                                 offset += 8;
 356                                 break;
 357                         }
 358
 359                         msg += linelen;
 360                         len -= linelen;
 361                         if (linelen == 1)
 362                                 hdr = 0;
 363                         if (hdr) {
 364                                 if (!memcmp(line, "author ", 7))
 365                                         offset += add_author_info(this_header + offset, line, linelen);
 366                                 continue;
 367                         }
 368                         memset(this_header + offset, ' ', 4);
 369                         memcpy(this_header + offset + 4, line, linelen);
 370                         offset += linelen + 4;
 371                 }
 372                 /* Make sure there is an EOLN */
 373                 if (this_header[offset-1] != '\n')
 374                         this_header[offset++] = '\n';
 375                 /* Add _another_ EOLN if we are doing diff output */
 376                 if (!silent)
 377                         this_header[offset++] = '\n';
 378                 this_header[offset] = 0;
 379         }
 380
 381         return this_header;
 382 }
 383
 384 static int diff_tree_commit(const unsigned char *commit, const char *name)
 385 {
 386         unsigned long size, offset;
 387         char *buf = read_object_with_reference(commit, "commit", &size, NULL);
 388
 389         if (!buf)
 390                 return -1;
 391
 392         if (!name) {
 393                 static char commit_name[60];
 394                 strcpy(commit_name, sha1_to_hex(commit));
 395                 name = commit_name;
 396         }
 397
 398         /* Root commit? */
 399         if (show_root_diff && memcmp(buf + 46, "parent ", 7)) {
 400                 header = generate_header(name, "root", buf, size);
 401                 diff_root_tree(commit, "");
 402         }
 403
 404         /* More than one parent? */
 405         if (ignore_merges) {
 406                 if (!memcmp(buf + 46 + 48, "parent ", 7))
 407                         return 0;
 408         }
 409
 410         offset = 46;
 411         while (offset + 48 < size && !memcmp(buf + offset, "parent ", 7)) {
 412                 unsigned char parent[20];
 413                 if (get_sha1_hex(buf + offset + 7, parent))
 414                         return -1;
 415                 header = generate_header(name, sha1_to_hex(parent), buf, size);
 416                 diff_tree_sha1_top(parent, commit, "");
 417                 if (!header && verbose_header) {
 418                         header_prefix = "\ndiff-tree ";
 419                         /*
 420                          * Don't print multiple merge entries if we
 421                          * don't print the diffs.
 422                          */
 423                         if (silent)
 424                                 break;
 425                 }
 426                 offset += 48;
 427         }
 428         return 0;
 429 }
 430
 431 static int diff_tree_stdin(char *line)
 432 {
 433         int len = strlen(line);
 434         unsigned char commit[20], parent[20];
 435         static char this_header[1000];
 436
 437         if (!len || line[len-1] != '\n')
 438                 return -1;
 439         line[len-1] = 0;
 440         if (get_sha1_hex(line, commit))
 441                 return -1;
 442         if (isspace(line[40]) && !get_sha1_hex(line+41, parent)) {
 443                 line[40] = 0;
 444                 line[81] = 0;
 445                 sprintf(this_header, "%s (from %s)\n", line, line+41);
 446                 header = this_header;
 447                 return diff_tree_sha1_top(parent, commit, "");
 448         }
 449         line[40] = 0;
 450         return diff_tree_commit(commit, line);
 451 }
 452
 453 static char *diff_tree_usage =
 454 "git-diff-tree [-p] [-r] [-z] [--stdin] [-M] [-C] [-R] [-S<string>] [-m] [-s] [-v] <tree-ish> <tree-ish>";
 455
 456 int main(int argc, char **argv)
 457 {
 458         int nr_sha1;
 459         char line[1000];
 460         unsigned char sha1[2][20];
 461
 462         nr_sha1 = 0;
 463         for (;;) {
 464                 char *arg;
 465
 466                 argv++;
 467                 argc--;
 468                 arg = *argv;
 469                 if (!arg)
 470                         break;
 471
 472                 if (*arg != '-') {
 473                         if (nr_sha1 < 2 && !get_sha1(arg, sha1[nr_sha1])) {
 474                                 nr_sha1++;
 475                                 continue;
 476                         }
 477                         break;
 478                 }
 479
 480                 if (!strcmp(arg, "--")) {
 481                         argv++;
 482                         argc--;
 483                         break;
 484                 }
 485                 if (!strcmp(arg, "-r")) {
 486                         recursive = 1;
 487                         continue;
 488                 }
 489                 if (!strcmp(arg, "-R")) {
 490                         reverse_diff = 1;
 491                         continue;
 492                 }
 493                 if (!strcmp(arg, "-p")) {
 494                         recursive = generate_patch = 1;
 495                         continue;
 496                 }
 497                 if (!strncmp(arg, "-S", 2)) {
 498                         pickaxe = arg + 2;
 499                         continue;
 500                 }
 501                 if (!strncmp(arg, "-M", 2)) {
 502                         detect_rename = recursive = generate_patch = 1;
 503                         diff_score_opt = diff_scoreopt_parse(arg);
 504                         continue;
 505                 }
 506                 if (!strncmp(arg, "-C", 2)) {
 507                         detect_rename = 2;
 508                         recursive = generate_patch = 1;
 509                         diff_score_opt = diff_scoreopt_parse(arg);
 510                         continue;
 511                 }
 512                 if (!strcmp(arg, "-z")) {
 513                         line_termination = '\0';
 514                         continue;
 515                 }
 516                 if (!strcmp(arg, "-m")) {
 517                         ignore_merges = 0;
 518                         continue;
 519                 }
 520                 if (!strcmp(arg, "-s")) {
 521                         silent = 1;
 522                         continue;
 523                 }
 524                 if (!strcmp(arg, "-v")) {
 525                         verbose_header = 1;
 526                         header_prefix = "diff-tree ";
 527                         continue;
 528                 }
 529                 if (!strcmp(arg, "--stdin")) {
 530                         read_stdin = 1;
 531                         continue;
 532                 }
 533                 if (!strcmp(arg, "--root")) {
 534                         show_root_diff = 1;
 535                         continue;
 536                 }
 537                 usage(diff_tree_usage);
 538         }
 539
 540         if (argc > 0) {
 541                 int i;
 542
 543                 paths = argv;
 544                 nr_paths = argc;
 545                 pathlens = xmalloc(nr_paths * sizeof(int));
 546                 for (i=0; i<nr_paths; i++)
 547                         pathlens[i] = strlen(paths[i]);
 548         }
 549
 550         switch (nr_sha1) {
 551         case 0:
 552                 if (!read_stdin)
 553                         usage(diff_tree_usage);
 554                 break;
 555         case 1:
 556                 diff_tree_commit(sha1[0], NULL);
 557                 break;
 558         case 2:
 559                 diff_tree_sha1_top(sha1[0], sha1[1], "");
 560                 break;
 561         }
 562
 563         if (!read_stdin)
 564                 return 0;
 565
 566         while (fgets(line, sizeof(line), stdin))
 567                 diff_tree_stdin(line);
 568
 569         return 0;
 570 }