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