diff-tree.c

   1 #include <ctype.h>
   2 #include "cache.h"
   3 #include "diff.h"
   4
   5 static int silent = 0;
   6 static int verbose_header = 0;
   7 static int ignore_merges = 1;
   8 static int recursive = 0;
   9 static int read_stdin = 0;
  10 static int line_termination = '\n';
  11 static int generate_patch = 0;
  12 static const char *header = NULL;
  13 static const char *header_prefix = "";
  14
  15 // What paths are we interested in?
  16 static int nr_paths = 0;
  17 static char **paths = NULL;
  18 static int *pathlens = NULL;
  19
  20 static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base);
  21
  22 static void update_tree_entry(void **bufp, unsigned long *sizep)
  23 {
  24         void *buf = *bufp;
  25         unsigned long size = *sizep;
  26         int len = strlen(buf) + 1 + 20;
  27
  28         if (size < len)
  29                 die("corrupt tree file");
  30         *bufp = buf + len;
  31         *sizep = size - len;
  32 }
  33
  34 static const unsigned char *extract(void *tree, unsigned long size, const char **pathp, unsigned int *modep)
  35 {
  36         int len = strlen(tree)+1;
  37         const unsigned char *sha1 = tree + len;
  38         const char *path = strchr(tree, ' ');
  39
  40         if (!path || size < len + 20 || sscanf(tree, "%o", modep) != 1)
  41                 die("corrupt tree file");
  42         *pathp = path+1;
  43         return sha1;
  44 }
  45
  46 static char *malloc_base(const char *base, const char *path, int pathlen)
  47 {
  48         int baselen = strlen(base);
  49         char *newbase = xmalloc(baselen + pathlen + 2);
  50         memcpy(newbase, base, baselen);
  51         memcpy(newbase + baselen, path, pathlen);
  52         memcpy(newbase + baselen + pathlen, "/", 2);
  53         return newbase;
  54 }
  55
  56 static void show_file(const char *prefix, void *tree, unsigned long size, const char *base);
  57 static void show_tree(const char *prefix, void *tree, unsigned long size, const char *base);
  58
  59 /* A file entry went away or appeared */
  60 static void show_file(const char *prefix, void *tree, unsigned long size, const char *base)
  61 {
  62         unsigned mode;
  63         const char *path;
  64         const unsigned char *sha1 = extract(tree, size, &path, &mode);
  65
  66         if (header) {
  67                 printf("%s", header);
  68                 header = NULL;
  69         }
  70
  71         if (silent)
  72                 return;
  73
  74         if (recursive && S_ISDIR(mode)) {
  75                 char type[20];
  76                 unsigned long size;
  77                 char *newbase = malloc_base(base, path, strlen(path));
  78                 void *tree;
  79
  80                 tree = read_sha1_file(sha1, type, &size);
  81                 if (!tree || strcmp(type, "tree"))
  82                         die("corrupt tree sha %s", sha1_to_hex(sha1));
  83
  84                 show_tree(prefix, tree, size, newbase);
  85
  86                 free(tree);
  87                 free(newbase);
  88                 return;
  89         }
  90
  91         if (generate_patch) {
  92                 if (!S_ISDIR(mode))
  93                         diff_addremove(prefix[0], mode, sha1, base, path);
  94         }
  95         else
  96                 printf("%s%06o\t%s\t%s\t%s%s%c", prefix, mode,
  97                        S_ISDIR(mode) ? "tree" : "blob",
  98                        sha1_to_hex(sha1), base, path,
  99                        line_termination);
 100 }
 101
 102 static int compare_tree_entry(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
 103 {
 104         unsigned mode1, mode2;
 105         const char *path1, *path2;
 106         const unsigned char *sha1, *sha2;
 107         int cmp, pathlen1, pathlen2;
 108         char old_sha1_hex[50];
 109
 110         sha1 = extract(tree1, size1, &path1, &mode1);
 111         sha2 = extract(tree2, size2, &path2, &mode2);
 112
 113         pathlen1 = strlen(path1);
 114         pathlen2 = strlen(path2);
 115         cmp = cache_name_compare(path1, pathlen1, path2, pathlen2);
 116         if (cmp < 0) {
 117                 show_file("-", tree1, size1, base);
 118                 return -1;
 119         }
 120         if (cmp > 0) {
 121                 show_file("+", tree2, size2, base);
 122                 return 1;
 123         }
 124         if (!memcmp(sha1, sha2, 20) && mode1 == mode2)
 125                 return 0;
 126
 127         /*
 128          * If the filemode has changed to/from a directory from/to a regular
 129          * file, we need to consider it a remove and an add.
 130          */
 131         if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
 132                 show_file("-", tree1, size1, base);
 133                 show_file("+", tree2, size2, base);
 134                 return 0;
 135         }
 136
 137         if (recursive && S_ISDIR(mode1)) {
 138                 int retval;
 139                 char *newbase = malloc_base(base, path1, pathlen1);
 140                 retval = diff_tree_sha1(sha1, sha2, newbase);
 141                 free(newbase);
 142                 return retval;
 143         }
 144
 145         if (header) {
 146                 printf("%s", header);
 147                 header = NULL;
 148         }
 149         if (silent)
 150                 return 0;
 151
 152         if (generate_patch) {
 153                 if (!S_ISDIR(mode1))
 154                         diff_change(mode1, mode2, sha1, sha2, base, path1);
 155         }
 156         else {
 157                 strcpy(old_sha1_hex, sha1_to_hex(sha1));
 158                 printf("*%06o->%06o\t%s\t%s->%s\t%s%s%c", mode1, mode2,
 159                        S_ISDIR(mode1) ? "tree" : "blob",
 160                        old_sha1_hex, sha1_to_hex(sha2), base, path1,
 161                        line_termination);
 162         }
 163         return 0;
 164 }
 165
 166 static int interesting(void *tree, unsigned long size, const char *base)
 167 {
 168         const char *path;
 169         unsigned mode;
 170         int i;
 171         int baselen, pathlen;
 172
 173         if (!nr_paths)
 174                 return 1;
 175
 176         (void)extract(tree, size, &path, &mode);
 177
 178         pathlen = strlen(path);
 179         baselen = strlen(base);
 180
 181         for (i=0; i < nr_paths; i++) {
 182                 const char *match = paths[i];
 183                 int matchlen = pathlens[i];
 184
 185                 if (baselen >= matchlen) {
 186                         /* If it doesn't match, move along... */
 187                         if (strncmp(base, match, matchlen))
 188                                 continue;
 189
 190                         /* The base is a subdirectory of a path which was specified. */
 191                         return 1;
 192                 }
 193
 194                 /* Does the base match? */
 195                 if (strncmp(base, match, baselen))
 196                         continue;
 197
 198                 match += baselen;
 199                 matchlen -= baselen;
 200
 201                 if (pathlen > matchlen)
 202                         continue;
 203
 204                 if (matchlen > pathlen) {
 205                         if (match[pathlen] != '/')
 206                                 continue;
 207                         if (!S_ISDIR(mode))
 208                                 continue;
 209                 }
 210
 211                 if (strncmp(path, match, pathlen))
 212                         continue;
 213
 214                 return 1;
 215         }
 216         return 0; /* No matches */
 217 }
 218
 219 /* A whole sub-tree went away or appeared */
 220 static void show_tree(const char *prefix, void *tree, unsigned long size, const char *base)
 221 {
 222         while (size) {
 223                 if (interesting(tree, size, base))
 224                         show_file(prefix, tree, size, base);
 225                 update_tree_entry(&tree, &size);
 226         }
 227 }
 228
 229 static int diff_tree(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
 230 {
 231         while (size1 | size2) {
 232                 if (nr_paths && size1 && !interesting(tree1, size1, base)) {
 233                         update_tree_entry(&tree1, &size1);
 234                         continue;
 235                 }
 236                 if (nr_paths && size2 && !interesting(tree2, size2, base)) {
 237                         update_tree_entry(&tree2, &size2);
 238                         continue;
 239                 }
 240                 if (!size1) {
 241                         show_file("+", tree2, size2, base);
 242                         update_tree_entry(&tree2, &size2);
 243                         continue;
 244                 }
 245                 if (!size2) {
 246                         show_file("-", tree1, size1, base);
 247                         update_tree_entry(&tree1, &size1);
 248                         continue;
 249                 }
 250                 switch (compare_tree_entry(tree1, size1, tree2, size2, base)) {
 251                 case -1:
 252                         update_tree_entry(&tree1, &size1);
 253                         continue;
 254                 case 0:
 255                         update_tree_entry(&tree1, &size1);
 256                         /* Fallthrough */
 257                 case 1:
 258                         update_tree_entry(&tree2, &size2);
 259                         continue;
 260                 }
 261                 die("diff-tree: internal error");
 262         }
 263         return 0;
 264 }
 265
 266 static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base)
 267 {
 268         void *tree1, *tree2;
 269         unsigned long size1, size2;
 270         int retval;
 271
 272         tree1 = read_object_with_reference(old, "tree", &size1, 0);
 273         if (!tree1)
 274                 die("unable to read source tree (%s)", sha1_to_hex(old));
 275         tree2 = read_object_with_reference(new, "tree", &size2, 0);
 276         if (!tree2)
 277                 die("unable to read destination tree (%s)", sha1_to_hex(new));
 278         retval = diff_tree(tree1, size1, tree2, size2, base);
 279         free(tree1);
 280         free(tree2);
 281         return retval;
 282 }
 283
 284 static int get_one_line(const char *msg, unsigned long len)
 285 {
 286         int ret = 0;
 287
 288         while (len--) {
 289                 ret++;
 290                 if (*msg++ == '\n')
 291                         break;
 292         }
 293         return ret;
 294 }
 295
 296 static int add_author_info(char *buf, const char *line, int len)
 297 {
 298         char *date;
 299         unsigned int namelen;
 300         unsigned long time;
 301         int tz;
 302
 303         line += strlen("author ");
 304         date = strchr(line, '>');
 305         if (!date)
 306                 return 0;
 307         namelen = ++date - line;
 308         time = strtoul(date, &date, 10);
 309         tz = strtol(date, NULL, 10);
 310
 311         return sprintf(buf, "Author: %.*s\nDate:   %s\n",
 312                 namelen, line,
 313                 show_date(time, tz));
 314 }
 315
 316 static char *generate_header(const char *commit, const char *parent, const char *msg, unsigned long len)
 317 {
 318         static char this_header[1000];
 319         int offset;
 320
 321         offset = sprintf(this_header, "%s%s (from %s)\n", header_prefix, commit, parent);
 322         if (verbose_header) {
 323                 int hdr = 1;
 324
 325                 for (;;) {
 326                         const char *line = msg;
 327                         int linelen = get_one_line(msg, len);
 328
 329                         if (!linelen)
 330                                 break;
 331                         if (offset + linelen + 10 > sizeof(this_header))
 332                                 break;
 333
 334                         msg += linelen;
 335                         len -= linelen;
 336                         if (linelen == 1)
 337                                 hdr = 0;
 338                         if (hdr) {
 339                                 if (!memcmp(line, "author ", 7))
 340                                         offset += add_author_info(this_header + offset, line, linelen);
 341                                 continue;
 342                         }
 343                         memset(this_header + offset, ' ', 4);
 344                         memcpy(this_header + offset + 4, line, linelen);
 345                         offset += linelen + 4;
 346                 }
 347                 this_header[offset++] = '\n';
 348                 this_header[offset] = 0;
 349         }
 350
 351         return this_header;
 352 }
 353
 354 static int diff_tree_commit(const unsigned char *commit, const char *name)
 355 {
 356         unsigned long size, offset;
 357         char *buf = read_object_with_reference(commit, "commit", &size, NULL);
 358
 359         if (!buf)
 360                 return -1;
 361
 362         /* More than one parent? */
 363         if (ignore_merges) {
 364                 if (!memcmp(buf + 46 + 48, "parent ", 7))
 365                         return 0;
 366         }
 367
 368         if (!name) {
 369                 static char commit_name[60];
 370                 strcpy(commit_name, sha1_to_hex(commit));
 371                 name = commit_name;
 372         }
 373
 374         offset = 46;
 375         while (offset + 48 < size && !memcmp(buf + offset, "parent ", 7)) {
 376                 unsigned char parent[20];
 377                 if (get_sha1_hex(buf + offset + 7, parent))
 378                         return -1;
 379                 header = generate_header(name, sha1_to_hex(parent), buf, size);
 380                 diff_tree_sha1(parent, commit, "");
 381                 if (!header && verbose_header)
 382                         header_prefix = "\ndiff-tree ";
 383                 offset += 48;
 384         }
 385         return 0;
 386 }
 387
 388 static int diff_tree_stdin(char *line)
 389 {
 390         int len = strlen(line);
 391         unsigned char commit[20], parent[20];
 392         static char this_header[1000];
 393
 394         if (!len || line[len-1] != '\n')
 395                 return -1;
 396         line[len-1] = 0;
 397         if (get_sha1_hex(line, commit))
 398                 return -1;
 399         if (isspace(line[40]) && !get_sha1_hex(line+41, parent)) {
 400                 line[40] = 0;
 401                 line[81] = 0;
 402                 sprintf(this_header, "%s (from %s)\n", line, line+41);
 403                 header = this_header;
 404                 return diff_tree_sha1(parent, commit, "");
 405         }
 406         line[40] = 0;
 407         return diff_tree_commit(commit, line);
 408 }
 409
 410 static char *diff_tree_usage =
 411 "diff-tree [-p] [-r] [-z] [--stdin] [-m] [-s] [-v] <tree sha1> <tree sha1>";
 412
 413 int main(int argc, char **argv)
 414 {
 415         int nr_sha1;
 416         char line[1000];
 417         unsigned char sha1[2][20];
 418
 419         nr_sha1 = 0;
 420         for (;;) {
 421                 char *arg;
 422
 423                 argv++;
 424                 argc--;
 425                 arg = *argv;
 426                 if (!arg)
 427                         break;
 428
 429                 if (*arg != '-') {
 430                         if (nr_sha1 < 2 && !get_sha1(arg, sha1[nr_sha1])) {
 431                                 nr_sha1++;
 432                                 continue;
 433                         }
 434                         break;
 435                 }
 436
 437                 if (!strcmp(arg, "--")) {
 438                         argv++;
 439                         argc--;
 440                         break;
 441                 }
 442                 if (!strcmp(arg, "-r")) {
 443                         recursive = 1;
 444                         continue;
 445                 }
 446                 if (!strcmp(arg, "-p")) {
 447                         recursive = generate_patch = 1;
 448                         continue;
 449                 }
 450                 if (!strcmp(arg, "-z")) {
 451                         line_termination = '\0';
 452                         continue;
 453                 }
 454                 if (!strcmp(arg, "-m")) {
 455                         ignore_merges = 0;
 456                         continue;
 457                 }
 458                 if (!strcmp(arg, "-s")) {
 459                         silent = 1;
 460                         continue;
 461                 }
 462                 if (!strcmp(arg, "-v")) {
 463                         verbose_header = 1;
 464                         header_prefix = "diff-tree ";
 465                         continue;
 466                 }
 467                 if (!strcmp(arg, "--stdin")) {
 468                         read_stdin = 1;
 469                         continue;
 470                 }
 471                 usage(diff_tree_usage);
 472         }
 473
 474         if (argc > 0) {
 475                 int i;
 476
 477                 paths = argv;
 478                 nr_paths = argc;
 479                 pathlens = xmalloc(nr_paths * sizeof(int));
 480                 for (i=0; i<nr_paths; i++)
 481                         pathlens[i] = strlen(paths[i]);
 482         }
 483
 484         switch (nr_sha1) {
 485         case 0:
 486                 if (!read_stdin)
 487                         usage(diff_tree_usage);
 488                 break;
 489         case 1:
 490                 diff_tree_commit(sha1[0], NULL);
 491                 break;
 492         case 2:
 493                 diff_tree_sha1(sha1[0], sha1[1], "");
 494                 break;
 495         }
 496
 497         if (!read_stdin)
 498                 return 0;
 499
 500         while (fgets(line, sizeof(line), stdin))
 501                 diff_tree_stdin(line);
 502
 503         return 0;
 504 }