diff-tree.c

   1 #include <ctype.h>
   2 #include "cache.h"
   3 #include "diff.h"
   4
   5 static int show_root_diff = 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 diff_output_format = DIFF_FORMAT_HUMAN;
  11 static int detect_rename = 0;
  12 static int reverse_diff = 0;
  13 static int diff_score_opt = 0;
  14 static const char *pickaxe = NULL;
  15 static const char *header = NULL;
  16 static const char *header_prefix = "";
  17
  18 // What paths are we interested in?
  19 static int nr_paths = 0;
  20 static const char **paths = NULL;
  21 static int *pathlens = NULL;
  22
  23 static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base);
  24
  25 static void update_tree_entry(void **bufp, unsigned long *sizep)
  26 {
  27         void *buf = *bufp;
  28         unsigned long size = *sizep;
  29         int len = strlen(buf) + 1 + 20;
  30
  31         if (size < len)
  32                 die("corrupt tree file");
  33         *bufp = buf + len;
  34         *sizep = size - len;
  35 }
  36
  37 static const unsigned char *extract(void *tree, unsigned long size, const char **pathp, unsigned int *modep)
  38 {
  39         int len = strlen(tree)+1;
  40         const unsigned char *sha1 = tree + len;
  41         const char *path = strchr(tree, ' ');
  42
  43         if (!path || size < len + 20 || sscanf(tree, "%o", modep) != 1)
  44                 die("corrupt tree file");
  45         *pathp = path+1;
  46         return sha1;
  47 }
  48
  49 static char *malloc_base(const char *base, const char *path, int pathlen)
  50 {
  51         int baselen = strlen(base);
  52         char *newbase = xmalloc(baselen + pathlen + 2);
  53         memcpy(newbase, base, baselen);
  54         memcpy(newbase + baselen, path, pathlen);
  55         memcpy(newbase + baselen + pathlen, "/", 2);
  56         return newbase;
  57 }
  58
  59 static void show_file(const char *prefix, void *tree, unsigned long size, const char *base);
  60 static void show_tree(const char *prefix, void *tree, unsigned long size, const char *base);
  61
  62 /* A file entry went away or appeared */
  63 static void show_file(const char *prefix, void *tree, unsigned long size, const char *base)
  64 {
  65         unsigned mode;
  66         const char *path;
  67         const unsigned char *sha1 = extract(tree, size, &path, &mode);
  68
  69         if (recursive && S_ISDIR(mode)) {
  70                 char type[20];
  71                 unsigned long size;
  72                 char *newbase = malloc_base(base, path, strlen(path));
  73                 void *tree;
  74
  75                 tree = read_sha1_file(sha1, type, &size);
  76                 if (!tree || strcmp(type, "tree"))
  77                         die("corrupt tree sha %s", sha1_to_hex(sha1));
  78
  79                 show_tree(prefix, tree, size, newbase);
  80
  81                 free(tree);
  82                 free(newbase);
  83                 return;
  84         }
  85
  86         diff_addremove(prefix[0], mode, sha1, base, path);
  87 }
  88
  89 static int compare_tree_entry(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
  90 {
  91         unsigned mode1, mode2;
  92         const char *path1, *path2;
  93         const unsigned char *sha1, *sha2;
  94         int cmp, pathlen1, pathlen2;
  95
  96         sha1 = extract(tree1, size1, &path1, &mode1);
  97         sha2 = extract(tree2, size2, &path2, &mode2);
  98
  99         pathlen1 = strlen(path1);
 100         pathlen2 = strlen(path2);
 101         cmp = base_name_compare(path1, pathlen1, mode1, path2, pathlen2, mode2);
 102         if (cmp < 0) {
 103                 show_file("-", tree1, size1, base);
 104                 return -1;
 105         }
 106         if (cmp > 0) {
 107                 show_file("+", tree2, size2, base);
 108                 return 1;
 109         }
 110         if (!memcmp(sha1, sha2, 20) && mode1 == mode2)
 111                 return 0;
 112
 113         /*
 114          * If the filemode has changed to/from a directory from/to a regular
 115          * file, we need to consider it a remove and an add.
 116          */
 117         if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
 118                 show_file("-", tree1, size1, base);
 119                 show_file("+", tree2, size2, base);
 120                 return 0;
 121         }
 122
 123         if (recursive && S_ISDIR(mode1)) {
 124                 int retval;
 125                 char *newbase = malloc_base(base, path1, pathlen1);
 126                 retval = diff_tree_sha1(sha1, sha2, newbase);
 127                 free(newbase);
 128                 return retval;
 129         }
 130
 131         diff_change(mode1, mode2, sha1, sha2, base, path1);
 132         return 0;
 133 }
 134
 135 static int interesting(void *tree, unsigned long size, const char *base)
 136 {
 137         const char *path;
 138         unsigned mode;
 139         int i;
 140         int baselen, pathlen;
 141
 142         if (!nr_paths)
 143                 return 1;
 144
 145         (void)extract(tree, size, &path, &mode);
 146
 147         pathlen = strlen(path);
 148         baselen = strlen(base);
 149
 150         for (i=0; i < nr_paths; i++) {
 151                 const char *match = paths[i];
 152                 int matchlen = pathlens[i];
 153
 154                 if (baselen >= matchlen) {
 155                         /* If it doesn't match, move along... */
 156                         if (strncmp(base, match, matchlen))
 157                                 continue;
 158
 159                         /* The base is a subdirectory of a path which was specified. */
 160                         return 1;
 161                 }
 162
 163                 /* Does the base match? */
 164                 if (strncmp(base, match, baselen))
 165                         continue;
 166
 167                 match += baselen;
 168                 matchlen -= baselen;
 169
 170                 if (pathlen > matchlen)
 171                         continue;
 172
 173                 if (matchlen > pathlen) {
 174                         if (match[pathlen] != '/')
 175                                 continue;
 176                         if (!S_ISDIR(mode))
 177                                 continue;
 178                 }
 179
 180                 if (strncmp(path, match, pathlen))
 181                         continue;
 182
 183                 return 1;
 184         }
 185         return 0; /* No matches */
 186 }
 187
 188 /* A whole sub-tree went away or appeared */
 189 static void show_tree(const char *prefix, void *tree, unsigned long size, const char *base)
 190 {
 191         while (size) {
 192                 if (interesting(tree, size, base))
 193                         show_file(prefix, tree, size, base);
 194                 update_tree_entry(&tree, &size);
 195         }
 196 }
 197
 198 static int diff_tree(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
 199 {
 200         while (size1 | size2) {
 201                 if (nr_paths && size1 && !interesting(tree1, size1, base)) {
 202                         update_tree_entry(&tree1, &size1);
 203                         continue;
 204                 }
 205                 if (nr_paths && size2 && !interesting(tree2, size2, base)) {
 206                         update_tree_entry(&tree2, &size2);
 207                         continue;
 208                 }
 209                 if (!size1) {
 210                         show_file("+", tree2, size2, base);
 211                         update_tree_entry(&tree2, &size2);
 212                         continue;
 213                 }
 214                 if (!size2) {
 215                         show_file("-", tree1, size1, base);
 216                         update_tree_entry(&tree1, &size1);
 217                         continue;
 218                 }
 219                 switch (compare_tree_entry(tree1, size1, tree2, size2, base)) {
 220                 case -1:
 221                         update_tree_entry(&tree1, &size1);
 222                         continue;
 223                 case 0:
 224                         update_tree_entry(&tree1, &size1);
 225                         /* Fallthrough */
 226                 case 1:
 227                         update_tree_entry(&tree2, &size2);
 228                         continue;
 229                 }
 230                 die("git-diff-tree: internal error");
 231         }
 232         return 0;
 233 }
 234
 235 static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base)
 236 {
 237         void *tree1, *tree2;
 238         unsigned long size1, size2;
 239         int retval;
 240
 241         tree1 = read_object_with_reference(old, "tree", &size1, NULL);
 242         if (!tree1)
 243                 die("unable to read source tree (%s)", sha1_to_hex(old));
 244         tree2 = read_object_with_reference(new, "tree", &size2, NULL);
 245         if (!tree2)
 246                 die("unable to read destination tree (%s)", sha1_to_hex(new));
 247         retval = diff_tree(tree1, size1, tree2, size2, base);
 248         free(tree1);
 249         free(tree2);
 250         return retval;
 251 }
 252
 253 static void call_diff_setup(void)
 254 {
 255         diff_setup(reverse_diff);
 256 }
 257
 258 static int call_diff_flush(void)
 259 {
 260         if (detect_rename)
 261                 diffcore_rename(detect_rename, diff_score_opt);
 262         if (pickaxe)
 263                 diffcore_pickaxe(pickaxe);
 264         if (diff_queue_is_empty()) {
 265                 diff_flush(DIFF_FORMAT_NO_OUTPUT, 0);
 266                 return 0;
 267         }
 268         if (nr_paths)
 269                 diffcore_pathspec(paths);
 270         if (header) {
 271                 if (diff_output_format == DIFF_FORMAT_MACHINE) {
 272                         const char *ep, *cp;
 273                         for (cp = header; *cp; cp = ep) {
 274                                 ep = strchr(cp, '\n');
 275                                 if (ep == 0) ep = cp + strlen(cp);
 276                                 printf("%.*s%c", ep-cp, cp, 0);
 277                                 if (*ep) ep++;
 278                         }
 279                 }
 280                 else {
 281                         printf("%s", header);
 282                 }
 283                 header = NULL;
 284         }
 285         diff_flush(diff_output_format, 1);
 286         return 1;
 287 }
 288
 289 static int diff_tree_sha1_top(const unsigned char *old,
 290                               const unsigned char *new, const char *base)
 291 {
 292         int ret;
 293
 294         call_diff_setup();
 295         ret = diff_tree_sha1(old, new, base);
 296         call_diff_flush();
 297         return ret;
 298 }
 299
 300 static int diff_root_tree(const unsigned char *new, const char *base)
 301 {
 302         int retval;
 303         void *tree;
 304         unsigned long size;
 305
 306         call_diff_setup();
 307         tree = read_object_with_reference(new, "tree", &size, NULL);
 308         if (!tree)
 309                 die("unable to read root tree (%s)", sha1_to_hex(new));
 310         retval = diff_tree("", 0, tree, size, base);
 311         free(tree);
 312         call_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[16384];
 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
 364                         /*
 365                          * We want some slop for indentation and a possible
 366                          * final "...". Thus the "+ 20".
 367                          */
 368                         if (offset + linelen + 20 > sizeof(this_header)) {
 369                                 memcpy(this_header + offset, "    ...\n", 8);
 370                                 offset += 8;
 371                                 break;
 372                         }
 373
 374                         msg += linelen;
 375                         len -= linelen;
 376                         if (linelen == 1)
 377                                 hdr = 0;
 378                         if (hdr) {
 379                                 if (!memcmp(line, "author ", 7))
 380                                         offset += add_author_info(this_header + offset, line, linelen);
 381                                 continue;
 382                         }
 383                         memset(this_header + offset, ' ', 4);
 384                         memcpy(this_header + offset + 4, line, linelen);
 385                         offset += linelen + 4;
 386                 }
 387                 /* Make sure there is an EOLN */
 388                 if (this_header[offset-1] != '\n')
 389                         this_header[offset++] = '\n';
 390                 /* Add _another_ EOLN if we are doing diff output */
 391                 this_header[offset++] = '\n';
 392                 this_header[offset] = 0;
 393         }
 394
 395         return this_header;
 396 }
 397
 398 static int diff_tree_commit(const unsigned char *commit, const char *name)
 399 {
 400         unsigned long size, offset;
 401         char *buf = read_object_with_reference(commit, "commit", &size, NULL);
 402
 403         if (!buf)
 404                 return -1;
 405
 406         if (!name) {
 407                 static char commit_name[60];
 408                 strcpy(commit_name, sha1_to_hex(commit));
 409                 name = commit_name;
 410         }
 411
 412         /* Root commit? */
 413         if (show_root_diff && memcmp(buf + 46, "parent ", 7)) {
 414                 header = generate_header(name, "root", buf, size);
 415                 diff_root_tree(commit, "");
 416         }
 417
 418         /* More than one parent? */
 419         if (ignore_merges) {
 420                 if (!memcmp(buf + 46 + 48, "parent ", 7))
 421                         return 0;
 422         }
 423
 424         offset = 46;
 425         while (offset + 48 < size && !memcmp(buf + offset, "parent ", 7)) {
 426                 unsigned char parent[20];
 427                 if (get_sha1_hex(buf + offset + 7, parent))
 428                         return -1;
 429                 header = generate_header(name, sha1_to_hex(parent), buf, size);
 430                 diff_tree_sha1_top(parent, commit, "");
 431                 if (!header && verbose_header) {
 432                         header_prefix = "\ndiff-tree ";
 433                         /*
 434                          * Don't print multiple merge entries if we
 435                          * don't print the diffs.
 436                          */
 437                 }
 438                 offset += 48;
 439         }
 440         return 0;
 441 }
 442
 443 static int diff_tree_stdin(char *line)
 444 {
 445         int len = strlen(line);
 446         unsigned char commit[20], parent[20];
 447         static char this_header[1000];
 448
 449         if (!len || line[len-1] != '\n')
 450                 return -1;
 451         line[len-1] = 0;
 452         if (get_sha1_hex(line, commit))
 453                 return -1;
 454         if (isspace(line[40]) && !get_sha1_hex(line+41, parent)) {
 455                 line[40] = 0;
 456                 line[81] = 0;
 457                 sprintf(this_header, "%s (from %s)\n", line, line+41);
 458                 header = this_header;
 459                 return diff_tree_sha1_top(parent, commit, "");
 460         }
 461         line[40] = 0;
 462         return diff_tree_commit(commit, line);
 463 }
 464
 465 static char *diff_tree_usage =
 466 "git-diff-tree [-p] [-r] [-z] [--stdin] [-M] [-C] [-R] [-S<string>] [-m] [-s] [-v] <tree-ish> <tree-ish>";
 467
 468 int main(int argc, const char **argv)
 469 {
 470         int nr_sha1;
 471         char line[1000];
 472         unsigned char sha1[2][20];
 473
 474         nr_sha1 = 0;
 475         for (;;) {
 476                 const char *arg;
 477
 478                 argv++;
 479                 argc--;
 480                 arg = *argv;
 481                 if (!arg)
 482                         break;
 483
 484                 if (*arg != '-') {
 485                         if (nr_sha1 < 2 && !get_sha1(arg, sha1[nr_sha1])) {
 486                                 nr_sha1++;
 487                                 continue;
 488                         }
 489                         break;
 490                 }
 491
 492                 if (!strcmp(arg, "--")) {
 493                         argv++;
 494                         argc--;
 495                         break;
 496                 }
 497                 if (!strcmp(arg, "-r")) {
 498                         recursive = 1;
 499                         continue;
 500                 }
 501                 if (!strcmp(arg, "-R")) {
 502                         reverse_diff = 1;
 503                         continue;
 504                 }
 505                 if (!strcmp(arg, "-p")) {
 506                         diff_output_format = DIFF_FORMAT_PATCH;
 507                         recursive = 1;
 508                         continue;
 509                 }
 510                 if (!strncmp(arg, "-S", 2)) {
 511                         pickaxe = arg + 2;
 512                         continue;
 513                 }
 514                 if (!strncmp(arg, "-M", 2)) {
 515                         detect_rename = DIFF_DETECT_RENAME;
 516                         diff_score_opt = diff_scoreopt_parse(arg);
 517                         continue;
 518                 }
 519                 if (!strncmp(arg, "-C", 2)) {
 520                         detect_rename = DIFF_DETECT_COPY;
 521                         diff_score_opt = diff_scoreopt_parse(arg);
 522                         continue;
 523                 }
 524                 if (!strcmp(arg, "-z")) {
 525                         diff_output_format = DIFF_FORMAT_MACHINE;
 526                         continue;
 527                 }
 528                 if (!strcmp(arg, "-m")) {
 529                         ignore_merges = 0;
 530                         continue;
 531                 }
 532                 if (!strcmp(arg, "-s")) {
 533                         diff_output_format = DIFF_FORMAT_NO_OUTPUT;
 534                         continue;
 535                 }
 536                 if (!strcmp(arg, "-v")) {
 537                         verbose_header = 1;
 538                         header_prefix = "diff-tree ";
 539                         continue;
 540                 }
 541                 if (!strcmp(arg, "--stdin")) {
 542                         read_stdin = 1;
 543                         continue;
 544                 }
 545                 if (!strcmp(arg, "--root")) {
 546                         show_root_diff = 1;
 547                         continue;
 548                 }
 549                 usage(diff_tree_usage);
 550         }
 551
 552         if (argc > 0) {
 553                 int i;
 554
 555                 paths = argv;
 556                 nr_paths = argc;
 557                 pathlens = xmalloc(nr_paths * sizeof(int));
 558                 for (i=0; i<nr_paths; i++)
 559                         pathlens[i] = strlen(paths[i]);
 560         }
 561
 562         switch (nr_sha1) {
 563         case 0:
 564                 if (!read_stdin)
 565                         usage(diff_tree_usage);
 566                 break;
 567         case 1:
 568                 diff_tree_commit(sha1[0], NULL);
 569                 break;
 570         case 2:
 571                 diff_tree_sha1_top(sha1[0], sha1[1], "");
 572                 break;
 573         }
 574
 575         if (!read_stdin)
 576                 return 0;
 577
 578         while (fgets(line, sizeof(line), stdin))
 579                 diff_tree_stdin(line);
 580
 581         return 0;
 582 }