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 (strncmp(path, match, pathlen))
 213                         continue;
 214
 215                 return 1;
 216         }
 217         return 0; /* No matches */
 218 }
 219
 220 static int diff_tree(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
 221 {
 222         while (size1 | size2) {
 223                 if (nr_paths && size1 && !interesting(tree1, size1, base)) {
 224                         update_tree_entry(&tree1, &size1);
 225                         continue;
 226                 }
 227                 if (nr_paths && size2 && !interesting(tree2, size2, base)) {
 228                         update_tree_entry(&tree2, &size2);
 229                         continue;
 230                 }
 231                 if (!size1) {
 232                         show_file("+", tree2, size2, base);
 233                         update_tree_entry(&tree2, &size2);
 234                         continue;
 235                 }
 236                 if (!size2) {
 237                         show_file("-", tree1, size1, base);
 238                         update_tree_entry(&tree1, &size1);
 239                         continue;
 240                 }
 241                 switch (compare_tree_entry(tree1, size1, tree2, size2, base)) {
 242                 case -1:
 243                         update_tree_entry(&tree1, &size1);
 244                         continue;
 245                 case 0:
 246                         update_tree_entry(&tree1, &size1);
 247                         /* Fallthrough */
 248                 case 1:
 249                         update_tree_entry(&tree2, &size2);
 250                         continue;
 251                 }
 252                 die("diff-tree: internal error");
 253         }
 254         return 0;
 255 }
 256
 257 static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base)
 258 {
 259         void *tree1, *tree2;
 260         unsigned long size1, size2;
 261         int retval;
 262
 263         tree1 = read_object_with_reference(old, "tree", &size1, 0);
 264         if (!tree1)
 265                 die("unable to read source tree (%s)", sha1_to_hex(old));
 266         tree2 = read_object_with_reference(new, "tree", &size2, 0);
 267         if (!tree2)
 268                 die("unable to read destination tree (%s)", sha1_to_hex(new));
 269         retval = diff_tree(tree1, size1, tree2, size2, base);
 270         free(tree1);
 271         free(tree2);
 272         return retval;
 273 }
 274
 275 static int get_one_line(const char *msg, unsigned long len)
 276 {
 277         int ret = 0;
 278
 279         while (len--) {
 280                 ret++;
 281                 if (*msg++ == '\n')
 282                         break;
 283         }
 284         return ret;
 285 }
 286
 287 static char *generate_header(const char *commit, const char *parent, const char *msg, unsigned long len)
 288 {
 289         static char this_header[1000];
 290         int offset;
 291
 292         offset = sprintf(this_header, "%s%s (from %s)\n", header_prefix, commit, parent);
 293         if (verbose_header) {
 294                 int hdr = 1;
 295
 296                 for (;;) {
 297                         const char *line = msg;
 298                         int linelen = get_one_line(msg, len);
 299
 300                         if (!linelen)
 301                                 break;
 302                         if (offset + linelen + 10 > sizeof(this_header))
 303                                 break;
 304
 305                         msg += linelen;
 306                         len -= linelen;
 307                         if (linelen == 1)
 308                                 hdr = 0;
 309                         if (hdr)
 310                                 continue;
 311                         memset(this_header + offset, ' ', 4);
 312                         memcpy(this_header + offset + 4, line, linelen);
 313                         offset += linelen + 4;
 314                 }
 315                 this_header[offset++] = '\n';
 316                 this_header[offset] = 0;
 317         }
 318
 319         return this_header;
 320 }
 321
 322 static int diff_tree_stdin(char *line)
 323 {
 324         int len = strlen(line);
 325         unsigned char commit[20], parent[20];
 326         unsigned long size, offset;
 327         static char this_header[1000];
 328         char *buf;
 329
 330         if (!len || line[len-1] != '\n')
 331                 return -1;
 332         line[len-1] = 0;
 333         if (get_sha1_hex(line, commit))
 334                 return -1;
 335         if (isspace(line[40]) && !get_sha1_hex(line+41, parent)) {
 336                 line[40] = 0;
 337                 line[81] = 0;
 338                 sprintf(this_header, "%s (from %s)\n", line, line+41);
 339                 header = this_header;
 340                 return diff_tree_sha1(parent, commit, "");
 341         }
 342         buf = read_object_with_reference(commit, "commit", &size, NULL);
 343         if (!buf)
 344                 return -1;
 345
 346         /* More than one parent? */
 347         if (ignore_merges) {
 348                 if (!memcmp(buf + 46 + 48, "parent ", 7))
 349                         return 0;
 350         }
 351
 352         line[40] = 0;
 353         offset = 46;
 354         while (offset + 48 < size && !memcmp(buf + offset, "parent ", 7)) {
 355                 if (get_sha1_hex(buf + offset + 7, parent))
 356                         return -1;
 357                 header = generate_header(line, sha1_to_hex(parent), buf, size);
 358                 diff_tree_sha1(parent, commit, "");
 359                 if (!header && verbose_header)
 360                         header_prefix = "\ndiff-tree ";
 361                 offset += 48;
 362         }
 363         return -1;
 364 }
 365
 366 static char *diff_tree_usage = "diff-tree [-p] [-r] [-z] <tree sha1> <tree sha1>";
 367
 368 int main(int argc, char **argv)
 369 {
 370         char line[1000];
 371         unsigned char old[20], new[20];
 372
 373         for (;;) {
 374                 char *arg;
 375
 376                 argv++;
 377                 argc--;
 378                 arg = *argv;
 379                 if (!arg || *arg != '-')
 380                         break;
 381
 382                 if (!strcmp(arg, "-")) {
 383                         argv++;
 384                         argc--;
 385                         break;
 386                 }
 387                 if (!strcmp(arg, "-r")) {
 388                         recursive = 1;
 389                         continue;
 390                 }
 391                 if (!strcmp(arg, "-p")) {
 392                         recursive = generate_patch = 1;
 393                         continue;
 394                 }
 395                 if (!strcmp(arg, "-z")) {
 396                         line_termination = '\0';
 397                         continue;
 398                 }
 399                 if (!strcmp(arg, "-m")) {
 400                         ignore_merges = 0;
 401                         continue;
 402                 }
 403                 if (!strcmp(arg, "-s")) {
 404                         silent = 1;
 405                         continue;
 406                 }
 407                 if (!strcmp(arg, "-v")) {
 408                         verbose_header = 1;
 409                         header_prefix = "diff-tree ";
 410                         continue;
 411                 }
 412                 if (!strcmp(arg, "--stdin")) {
 413                         read_stdin = 1;
 414                         continue;
 415                 }
 416                 usage(diff_tree_usage);
 417         }
 418
 419         if (!read_stdin) {
 420                 if (argc < 2 || get_sha1(argv[0], old) || get_sha1(argv[1], new))
 421                         usage(diff_tree_usage);
 422                 argv += 2;
 423                 argc -= 2;
 424         }
 425
 426         if (argc > 0) {
 427                 int i;
 428
 429                 paths = argv;
 430                 nr_paths = argc;
 431                 pathlens = xmalloc(nr_paths * sizeof(int));
 432                 for (i=0; i<nr_paths; i++)
 433                         pathlens[i] = strlen(paths[i]);
 434         }
 435
 436         if (!read_stdin)
 437                 return diff_tree_sha1(old, new, "");
 438
 439         while (fgets(line, sizeof(line), stdin))
 440                 diff_tree_stdin(line);
 441
 442         return 0;
 443 }