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