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