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 const char *header = NULL;
  15 static const char *header_prefix = "";
  16
  17 // What paths are we interested in?
  18 static int nr_paths = 0;
  19 static char **paths = NULL;
  20 static int *pathlens = NULL;
  21
  22 static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base);
  23
  24 static void update_tree_entry(void **bufp, unsigned long *sizep)
  25 {
  26         void *buf = *bufp;
  27         unsigned long size = *sizep;
  28         int len = strlen(buf) + 1 + 20;
  29
  30         if (size < len)
  31                 die("corrupt tree file");
  32         *bufp = buf + len;
  33         *sizep = size - len;
  34 }
  35
  36 static const unsigned char *extract(void *tree, unsigned long size, const char **pathp, unsigned int *modep)
  37 {
  38         int len = strlen(tree)+1;
  39         const unsigned char *sha1 = tree + len;
  40         const char *path = strchr(tree, ' ');
  41
  42         if (!path || size < len + 20 || sscanf(tree, "%o", modep) != 1)
  43                 die("corrupt tree file");
  44         *pathp = path+1;
  45         return sha1;
  46 }
  47
  48 static char *malloc_base(const char *base, const char *path, int pathlen)
  49 {
  50         int baselen = strlen(base);
  51         char *newbase = xmalloc(baselen + pathlen + 2);
  52         memcpy(newbase, base, baselen);
  53         memcpy(newbase + baselen, path, pathlen);
  54         memcpy(newbase + baselen + pathlen, "/", 2);
  55         return newbase;
  56 }
  57
  58 static void show_file(const char *prefix, void *tree, unsigned long size, const char *base);
  59 static void show_tree(const char *prefix, void *tree, unsigned long size, const char *base);
  60
  61 /* A file entry went away or appeared */
  62 static void show_file(const char *prefix, void *tree, unsigned long size, const char *base)
  63 {
  64         unsigned mode;
  65         const char *path;
  66         const unsigned char *sha1 = extract(tree, size, &path, &mode);
  67
  68         if (header) {
  69                 printf("%s", header);
  70                 header = NULL;
  71         }
  72
  73         if (silent)
  74                 return;
  75
  76         if (recursive && S_ISDIR(mode)) {
  77                 char type[20];
  78                 unsigned long size;
  79                 char *newbase = malloc_base(base, path, strlen(path));
  80                 void *tree;
  81
  82                 tree = read_sha1_file(sha1, type, &size);
  83                 if (!tree || strcmp(type, "tree"))
  84                         die("corrupt tree sha %s", sha1_to_hex(sha1));
  85
  86                 show_tree(prefix, tree, size, newbase);
  87
  88                 free(tree);
  89                 free(newbase);
  90                 return;
  91         }
  92
  93         if (generate_patch) {
  94                 if (!S_ISDIR(mode))
  95                         diff_addremove(prefix[0], mode, sha1, base, path);
  96         }
  97         else
  98                 printf("%s%06o\t%s\t%s\t%s%s%c", prefix, mode,
  99                        S_ISDIR(mode) ? "tree" : "blob",
 100                        sha1_to_hex(sha1), base, path,
 101                        line_termination);
 102 }
 103
 104 static int compare_tree_entry(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
 105 {
 106         unsigned mode1, mode2;
 107         const char *path1, *path2;
 108         const unsigned char *sha1, *sha2;
 109         int cmp, pathlen1, pathlen2;
 110         char old_sha1_hex[50];
 111
 112         sha1 = extract(tree1, size1, &path1, &mode1);
 113         sha2 = extract(tree2, size2, &path2, &mode2);
 114
 115         pathlen1 = strlen(path1);
 116         pathlen2 = strlen(path2);
 117         cmp = cache_name_compare(path1, pathlen1, path2, pathlen2);
 118         if (cmp < 0) {
 119                 show_file("-", tree1, size1, base);
 120                 return -1;
 121         }
 122         if (cmp > 0) {
 123                 show_file("+", tree2, size2, base);
 124                 return 1;
 125         }
 126         if (!memcmp(sha1, sha2, 20) && mode1 == mode2)
 127                 return 0;
 128
 129         /*
 130          * If the filemode has changed to/from a directory from/to a regular
 131          * file, we need to consider it a remove and an add.
 132          */
 133         if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
 134                 show_file("-", tree1, size1, base);
 135                 show_file("+", tree2, size2, base);
 136                 return 0;
 137         }
 138
 139         if (recursive && S_ISDIR(mode1)) {
 140                 int retval;
 141                 char *newbase = malloc_base(base, path1, pathlen1);
 142                 retval = diff_tree_sha1(sha1, sha2, newbase);
 143                 free(newbase);
 144                 return retval;
 145         }
 146
 147         if (header) {
 148                 printf("%s", header);
 149                 header = NULL;
 150         }
 151         if (silent)
 152                 return 0;
 153
 154         if (generate_patch) {
 155                 if (!S_ISDIR(mode1))
 156                         diff_change(mode1, mode2, sha1, sha2, base, path1);
 157         }
 158         else {
 159                 strcpy(old_sha1_hex, sha1_to_hex(sha1));
 160                 printf("*%06o->%06o\t%s\t%s->%s\t%s%s%c", mode1, mode2,
 161                        S_ISDIR(mode1) ? "tree" : "blob",
 162                        old_sha1_hex, sha1_to_hex(sha2), base, path1,
 163                        line_termination);
 164         }
 165         return 0;
 166 }
 167
 168 static int interesting(void *tree, unsigned long size, const char *base)
 169 {
 170         const char *path;
 171         unsigned mode;
 172         int i;
 173         int baselen, pathlen;
 174
 175         if (!nr_paths)
 176                 return 1;
 177
 178         (void)extract(tree, size, &path, &mode);
 179
 180         pathlen = strlen(path);
 181         baselen = strlen(base);
 182
 183         for (i=0; i < nr_paths; i++) {
 184                 const char *match = paths[i];
 185                 int matchlen = pathlens[i];
 186
 187                 if (baselen >= matchlen) {
 188                         /* If it doesn't match, move along... */
 189                         if (strncmp(base, match, matchlen))
 190                                 continue;
 191
 192                         /* The base is a subdirectory of a path which was specified. */
 193                         return 1;
 194                 }
 195
 196                 /* Does the base match? */
 197                 if (strncmp(base, match, baselen))
 198                         continue;
 199
 200                 match += baselen;
 201                 matchlen -= baselen;
 202
 203                 if (pathlen > matchlen)
 204                         continue;
 205
 206                 if (matchlen > pathlen) {
 207                         if (match[pathlen] != '/')
 208                                 continue;
 209                         if (!S_ISDIR(mode))
 210                                 continue;
 211                 }
 212
 213                 if (strncmp(path, match, pathlen))
 214                         continue;
 215
 216                 return 1;
 217         }
 218         return 0; /* No matches */
 219 }
 220
 221 /* A whole sub-tree went away or appeared */
 222 static void show_tree(const char *prefix, void *tree, unsigned long size, const char *base)
 223 {
 224         while (size) {
 225                 if (interesting(tree, size, base))
 226                         show_file(prefix, tree, size, base);
 227                 update_tree_entry(&tree, &size);
 228         }
 229 }
 230
 231 static int diff_tree(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
 232 {
 233         while (size1 | size2) {
 234                 if (nr_paths && size1 && !interesting(tree1, size1, base)) {
 235                         update_tree_entry(&tree1, &size1);
 236                         continue;
 237                 }
 238                 if (nr_paths && size2 && !interesting(tree2, size2, base)) {
 239                         update_tree_entry(&tree2, &size2);
 240                         continue;
 241                 }
 242                 if (!size1) {
 243                         show_file("+", tree2, size2, base);
 244                         update_tree_entry(&tree2, &size2);
 245                         continue;
 246                 }
 247                 if (!size2) {
 248                         show_file("-", tree1, size1, base);
 249                         update_tree_entry(&tree1, &size1);
 250                         continue;
 251                 }
 252                 switch (compare_tree_entry(tree1, size1, tree2, size2, base)) {
 253                 case -1:
 254                         update_tree_entry(&tree1, &size1);
 255                         continue;
 256                 case 0:
 257                         update_tree_entry(&tree1, &size1);
 258                         /* Fallthrough */
 259                 case 1:
 260                         update_tree_entry(&tree2, &size2);
 261                         continue;
 262                 }
 263                 die("git-diff-tree: internal error");
 264         }
 265         return 0;
 266 }
 267
 268 static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base)
 269 {
 270         void *tree1, *tree2;
 271         unsigned long size1, size2;
 272         int retval;
 273
 274         tree1 = read_object_with_reference(old, "tree", &size1, 0);
 275         if (!tree1)
 276                 die("unable to read source tree (%s)", sha1_to_hex(old));
 277         tree2 = read_object_with_reference(new, "tree", &size2, 0);
 278         if (!tree2)
 279                 die("unable to read destination tree (%s)", sha1_to_hex(new));
 280         retval = diff_tree(tree1, size1, tree2, size2, base);
 281         free(tree1);
 282         free(tree2);
 283         return retval;
 284 }
 285
 286 static int diff_tree_sha1_top(const unsigned char *old,
 287                               const unsigned char *new, const char *base)
 288 {
 289         int ret;
 290         if (generate_patch)
 291                 diff_setup(detect_rename, 0, 0, 0, 0);
 292         ret = diff_tree_sha1(old, new, base);
 293         if (generate_patch)
 294                 diff_flush();
 295         return ret;
 296 }
 297
 298 static int diff_root_tree(const unsigned char *new, const char *base)
 299 {
 300         int retval;
 301         void *tree;
 302         unsigned long size;
 303
 304         if (generate_patch)
 305                 diff_setup(detect_rename, 0, 0, 0, 0);
 306         tree = read_object_with_reference(new, "tree", &size, 0);
 307         if (!tree)
 308                 die("unable to read root tree (%s)", sha1_to_hex(new));
 309         retval = diff_tree("", 0, tree, size, base);
 310         free(tree);
 311         if (generate_patch)
 312                 diff_flush();
 313         return retval;
 314 }
 315
 316 static int get_one_line(const char *msg, unsigned long len)
 317 {
 318         int ret = 0;
 319
 320         while (len--) {
 321                 ret++;
 322                 if (*msg++ == '\n')
 323                         break;
 324         }
 325         return ret;
 326 }
 327
 328 static int add_author_info(char *buf, const char *line, int len)
 329 {
 330         char *date;
 331         unsigned int namelen;
 332         unsigned long time;
 333         int tz;
 334
 335         line += strlen("author ");
 336         date = strchr(line, '>');
 337         if (!date)
 338                 return 0;
 339         namelen = ++date - line;
 340         time = strtoul(date, &date, 10);
 341         tz = strtol(date, NULL, 10);
 342
 343         return sprintf(buf, "Author: %.*s\nDate:   %s\n",
 344                 namelen, line,
 345                 show_date(time, tz));
 346 }
 347
 348 static char *generate_header(const char *commit, const char *parent, const char *msg, unsigned long len)
 349 {
 350         static char this_header[1000];
 351         int offset;
 352
 353         offset = sprintf(this_header, "%s%s (from %s)\n", header_prefix, commit, parent);
 354         if (verbose_header) {
 355                 int hdr = 1;
 356
 357                 for (;;) {
 358                         const char *line = msg;
 359                         int linelen = get_one_line(msg, len);
 360
 361                         if (!linelen)
 362                                 break;
 363                         if (offset + linelen + 10 > sizeof(this_header))
 364                                 break;
 365
 366                         msg += linelen;
 367                         len -= linelen;
 368                         if (linelen == 1)
 369                                 hdr = 0;
 370                         if (hdr) {
 371                                 if (!memcmp(line, "author ", 7))
 372                                         offset += add_author_info(this_header + offset, line, linelen);
 373                                 continue;
 374                         }
 375                         memset(this_header + offset, ' ', 4);
 376                         memcpy(this_header + offset + 4, line, linelen);
 377                         offset += linelen + 4;
 378                 }
 379                 this_header[offset++] = '\n';
 380                 this_header[offset] = 0;
 381         }
 382
 383         return this_header;
 384 }
 385
 386 static int diff_tree_commit(const unsigned char *commit, const char *name)
 387 {
 388         unsigned long size, offset;
 389         char *buf = read_object_with_reference(commit, "commit", &size, NULL);
 390
 391         if (!buf)
 392                 return -1;
 393
 394         if (!name) {
 395                 static char commit_name[60];
 396                 strcpy(commit_name, sha1_to_hex(commit));
 397                 name = commit_name;
 398         }
 399
 400         /* Root commit? */
 401         if (show_root_diff && memcmp(buf + 46, "parent ", 7)) {
 402                 header = generate_header(name, "root", buf, size);
 403                 diff_root_tree(commit, "");
 404         }
 405
 406         /* More than one parent? */
 407         if (ignore_merges) {
 408                 if (!memcmp(buf + 46 + 48, "parent ", 7))
 409                         return 0;
 410         }
 411
 412         offset = 46;
 413         while (offset + 48 < size && !memcmp(buf + offset, "parent ", 7)) {
 414                 unsigned char parent[20];
 415                 if (get_sha1_hex(buf + offset + 7, parent))
 416                         return -1;
 417                 header = generate_header(name, sha1_to_hex(parent), buf, size);
 418                 diff_tree_sha1_top(parent, commit, "");
 419                 if (!header && verbose_header)
 420                         header_prefix = "\ndiff-tree ";
 421                 offset += 48;
 422         }
 423         return 0;
 424 }
 425
 426 static int diff_tree_stdin(char *line)
 427 {
 428         int len = strlen(line);
 429         unsigned char commit[20], parent[20];
 430         static char this_header[1000];
 431
 432         if (!len || line[len-1] != '\n')
 433                 return -1;
 434         line[len-1] = 0;
 435         if (get_sha1_hex(line, commit))
 436                 return -1;
 437         if (isspace(line[40]) && !get_sha1_hex(line+41, parent)) {
 438                 line[40] = 0;
 439                 line[81] = 0;
 440                 sprintf(this_header, "%s (from %s)\n", line, line+41);
 441                 header = this_header;
 442                 return diff_tree_sha1_top(parent, commit, "");
 443         }
 444         line[40] = 0;
 445         return diff_tree_commit(commit, line);
 446 }
 447
 448 static char *diff_tree_usage =
 449 "git-diff-tree [-p] [-r] [-z] [--stdin] [-M] [-m] [-s] [-v] <tree-ish> <tree-ish>";
 450
 451 int main(int argc, char **argv)
 452 {
 453         int nr_sha1;
 454         char line[1000];
 455         unsigned char sha1[2][20];
 456
 457         nr_sha1 = 0;
 458         for (;;) {
 459                 char *arg;
 460
 461                 argv++;
 462                 argc--;
 463                 arg = *argv;
 464                 if (!arg)
 465                         break;
 466
 467                 if (*arg != '-') {
 468                         if (nr_sha1 < 2 && !get_sha1(arg, sha1[nr_sha1])) {
 469                                 nr_sha1++;
 470                                 continue;
 471                         }
 472                         break;
 473                 }
 474
 475                 if (!strcmp(arg, "--")) {
 476                         argv++;
 477                         argc--;
 478                         break;
 479                 }
 480                 if (!strcmp(arg, "-r")) {
 481                         recursive = 1;
 482                         continue;
 483                 }
 484                 if (!strcmp(arg, "-p")) {
 485                         recursive = generate_patch = 1;
 486                         continue;
 487                 }
 488                 if (!strcmp(arg, "-M")) {
 489                         detect_rename = recursive = generate_patch = 1;
 490                         continue;
 491                 }
 492                 if (!strcmp(arg, "-z")) {
 493                         line_termination = '\0';
 494                         continue;
 495                 }
 496                 if (!strcmp(arg, "-m")) {
 497                         ignore_merges = 0;
 498                         continue;
 499                 }
 500                 if (!strcmp(arg, "-s")) {
 501                         silent = 1;
 502                         continue;
 503                 }
 504                 if (!strcmp(arg, "-v")) {
 505                         verbose_header = 1;
 506                         header_prefix = "diff-tree ";
 507                         continue;
 508                 }
 509                 if (!strcmp(arg, "--stdin")) {
 510                         read_stdin = 1;
 511                         continue;
 512                 }
 513                 if (!strcmp(arg, "--root")) {
 514                         show_root_diff = 1;
 515                         continue;
 516                 }
 517                 usage(diff_tree_usage);
 518         }
 519
 520         if (argc > 0) {
 521                 int i;
 522
 523                 paths = argv;
 524                 nr_paths = argc;
 525                 pathlens = xmalloc(nr_paths * sizeof(int));
 526                 for (i=0; i<nr_paths; i++)
 527                         pathlens[i] = strlen(paths[i]);
 528         }
 529
 530         switch (nr_sha1) {
 531         case 0:
 532                 if (!read_stdin)
 533                         usage(diff_tree_usage);
 534                 break;
 535         case 1:
 536                 diff_tree_commit(sha1[0], NULL);
 537                 break;
 538         case 2:
 539                 diff_tree_sha1_top(sha1[0], sha1[1], "");
 540                 break;
 541         }
 542
 543         if (!read_stdin)
 544                 return 0;
 545
 546         while (fgets(line, sizeof(line), stdin))
 547                 diff_tree_stdin(line);
 548
 549         return 0;
 550 }