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