diff-tree.c

   1 #include <ctype.h>
   2 #include "cache.h"
   3 #include "diff.h"
   4
   5 static int ignore_merges = 1;
   6 static int recursive = 0;
   7 static int read_stdin = 0;
   8 static int line_termination = '\n';
   9 static int generate_patch = 0;
  10
  11 // What paths are we interested in?
  12 static int nr_paths = 0;
  13 static char **paths = NULL;
  14 static int *pathlens = NULL;
  15
  16 static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base);
  17
  18 static void update_tree_entry(void **bufp, unsigned long *sizep)
  19 {
  20         void *buf = *bufp;
  21         unsigned long size = *sizep;
  22         int len = strlen(buf) + 1 + 20;
  23
  24         if (size < len)
  25                 die("corrupt tree file");
  26         *bufp = buf + len;
  27         *sizep = size - len;
  28 }
  29
  30 static const unsigned char *extract(void *tree, unsigned long size, const char **pathp, unsigned int *modep)
  31 {
  32         int len = strlen(tree)+1;
  33         const unsigned char *sha1 = tree + len;
  34         const char *path = strchr(tree, ' ');
  35
  36         if (!path || size < len + 20 || sscanf(tree, "%o", modep) != 1)
  37                 die("corrupt tree file");
  38         *pathp = path+1;
  39         return sha1;
  40 }
  41
  42 static char *malloc_base(const char *base, const char *path, int pathlen)
  43 {
  44         int baselen = strlen(base);
  45         char *newbase = xmalloc(baselen + pathlen + 2);
  46         memcpy(newbase, base, baselen);
  47         memcpy(newbase + baselen, path, pathlen);
  48         memcpy(newbase + baselen + pathlen, "/", 2);
  49         return newbase;
  50 }
  51
  52 static void show_file(const char *prefix, void *tree, unsigned long size, const char *base);
  53
  54 /* A whole sub-tree went away or appeared */
  55 static void show_tree(const char *prefix, void *tree, unsigned long size, const char *base)
  56 {
  57         while (size) {
  58                 show_file(prefix, tree, size, base);
  59                 update_tree_entry(&tree, &size);
  60         }
  61 }
  62
  63 /* A file entry went away or appeared */
  64 static void show_file(const char *prefix, void *tree, unsigned long size, const char *base)
  65 {
  66         unsigned mode;
  67         const char *path;
  68         const unsigned char *sha1 = extract(tree, size, &path, &mode);
  69
  70         if (recursive && S_ISDIR(mode)) {
  71                 char type[20];
  72                 unsigned long size;
  73                 char *newbase = malloc_base(base, path, strlen(path));
  74                 void *tree;
  75
  76                 tree = read_sha1_file(sha1, type, &size);
  77                 if (!tree || strcmp(type, "tree"))
  78                         die("corrupt tree sha %s", sha1_to_hex(sha1));
  79
  80                 show_tree(prefix, tree, size, newbase);
  81
  82                 free(tree);
  83                 free(newbase);
  84                 return;
  85         }
  86
  87         if (generate_patch) {
  88                 if (!S_ISDIR(mode))
  89                         diff_addremove(prefix[0], mode, sha1, base, path);
  90         }
  91         else
  92                 printf("%s%06o\t%s\t%s\t%s%s%c", prefix, mode,
  93                        S_ISDIR(mode) ? "tree" : "blob",
  94                        sha1_to_hex(sha1), base, path,
  95                        line_termination);
  96 }
  97
  98 static int compare_tree_entry(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
  99 {
 100         unsigned mode1, mode2;
 101         const char *path1, *path2;
 102         const unsigned char *sha1, *sha2;
 103         int cmp, pathlen1, pathlen2;
 104         char old_sha1_hex[50];
 105
 106         sha1 = extract(tree1, size1, &path1, &mode1);
 107         sha2 = extract(tree2, size2, &path2, &mode2);
 108
 109         pathlen1 = strlen(path1);
 110         pathlen2 = strlen(path2);
 111         cmp = cache_name_compare(path1, pathlen1, path2, pathlen2);
 112         if (cmp < 0) {
 113                 show_file("-", tree1, size1, base);
 114                 return -1;
 115         }
 116         if (cmp > 0) {
 117                 show_file("+", tree2, size2, base);
 118                 return 1;
 119         }
 120         if (!memcmp(sha1, sha2, 20) && mode1 == mode2)
 121                 return 0;
 122
 123         /*
 124          * If the filemode has changed to/from a directory from/to a regular
 125          * file, we need to consider it a remove and an add.
 126          */
 127         if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
 128                 show_file("-", tree1, size1, base);
 129                 show_file("+", tree2, size2, base);
 130                 return 0;
 131         }
 132
 133         if (recursive && S_ISDIR(mode1)) {
 134                 int retval;
 135                 char *newbase = malloc_base(base, path1, pathlen1);
 136                 retval = diff_tree_sha1(sha1, sha2, newbase);
 137                 free(newbase);
 138                 return retval;
 139         }
 140
 141         if (generate_patch) {
 142                 if (!S_ISDIR(mode1))
 143                         diff_change(mode1, mode2, sha1, sha2, base, path1);
 144         }
 145         else {
 146                 strcpy(old_sha1_hex, sha1_to_hex(sha1));
 147                 printf("*%06o->%06o\t%s\t%s->%s\t%s%s%c", mode1, mode2,
 148                        S_ISDIR(mode1) ? "tree" : "blob",
 149                        old_sha1_hex, sha1_to_hex(sha2), base, path1,
 150                        line_termination);
 151         }
 152         return 0;
 153 }
 154
 155 static int interesting(void *tree, unsigned long size, const char *base)
 156 {
 157         const char *path;
 158         unsigned mode;
 159         int i;
 160         int baselen, pathlen;
 161
 162         if (!nr_paths)
 163                 return 1;
 164
 165         (void)extract(tree, size, &path, &mode);
 166
 167         pathlen = strlen(path);
 168         baselen = strlen(base);
 169
 170         for (i=0; i < nr_paths; i++) {
 171                 const char *match = paths[i];
 172                 int matchlen = pathlens[i];
 173
 174                 if (baselen >= matchlen) {
 175                         /* If it doesn't match, move along... */
 176                         if (strncmp(base, match, matchlen))
 177                                 continue;
 178
 179                         /* The base is a subdirectory of a path which was specified. */
 180                         return 1;
 181                 }
 182
 183                 /* Does the base match? */
 184                 if (strncmp(base, match, baselen))
 185                         continue;
 186
 187                 match += baselen;
 188                 matchlen -= baselen;
 189
 190                 if (pathlen > matchlen)
 191                         continue;
 192
 193                 if (strncmp(path, match, pathlen))
 194                         continue;
 195
 196                 return 1;
 197         }
 198         return 0; /* No matches */
 199 }
 200
 201 static int diff_tree(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
 202 {
 203         while (size1 | size2) {
 204                 if (nr_paths && size1 && !interesting(tree1, size1, base)) {
 205                         update_tree_entry(&tree1, &size1);
 206                         continue;
 207                 }
 208                 if (nr_paths && size2 && !interesting(tree2, size2, base)) {
 209                         update_tree_entry(&tree2, &size2);
 210                         continue;
 211                 }
 212                 if (!size1) {
 213                         show_file("+", tree2, size2, base);
 214                         update_tree_entry(&tree2, &size2);
 215                         continue;
 216                 }
 217                 if (!size2) {
 218                         show_file("-", tree1, size1, base);
 219                         update_tree_entry(&tree1, &size1);
 220                         continue;
 221                 }
 222                 switch (compare_tree_entry(tree1, size1, tree2, size2, base)) {
 223                 case -1:
 224                         update_tree_entry(&tree1, &size1);
 225                         continue;
 226                 case 0:
 227                         update_tree_entry(&tree1, &size1);
 228                         /* Fallthrough */
 229                 case 1:
 230                         update_tree_entry(&tree2, &size2);
 231                         continue;
 232                 }
 233                 die("diff-tree: internal error");
 234         }
 235         return 0;
 236 }
 237
 238 static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base)
 239 {
 240         void *tree1, *tree2;
 241         unsigned long size1, size2;
 242         int retval;
 243
 244         tree1 = read_object_with_reference(old, "tree", &size1, 0);
 245         if (!tree1)
 246                 die("unable to read source tree (%s)", sha1_to_hex(old));
 247         tree2 = read_object_with_reference(new, "tree", &size2, 0);
 248         if (!tree2)
 249                 die("unable to read destination tree (%s)", sha1_to_hex(new));
 250         retval = diff_tree(tree1, size1, tree2, size2, base);
 251         free(tree1);
 252         free(tree2);
 253         return retval;
 254 }
 255
 256 static int diff_tree_stdin(char *line)
 257 {
 258         int len = strlen(line);
 259         unsigned char commit[20], parent[20];
 260         unsigned long size, offset;
 261         char *buf;
 262
 263         if (!len || line[len-1] != '\n')
 264                 return -1;
 265         line[len-1] = 0;
 266         if (get_sha1_hex(line, commit))
 267                 return -1;
 268         if (isspace(line[40]) && !get_sha1_hex(line+41, parent)) {
 269                 line[40] = ' ';
 270                 line[81] = 0;
 271                 printf("%s:\n", line);
 272                 return diff_tree_sha1(parent, commit, "");
 273         }
 274         buf = read_object_with_reference(commit, "commit", &size, NULL);
 275         if (!buf)
 276                 return -1;
 277
 278         /* More than one parent? */
 279         if (ignore_merges) {
 280                 if (!memcmp(buf + 46 + 48, "parent ", 7))
 281                         return 0;
 282         }
 283
 284         line[40] = 0;
 285         offset = 46;
 286         while (offset + 48 < size && !memcmp(buf + offset, "parent ", 7)) {
 287                 if (get_sha1_hex(buf + offset + 7, parent))
 288                         return -1;
 289                 printf("%s %s:\n", line, sha1_to_hex(parent));
 290                 diff_tree_sha1(parent, commit, "");
 291                 offset += 48;
 292         }
 293         return -1;
 294 }
 295
 296 static char *diff_tree_usage = "diff-tree [-p] [-r] [-z] <tree sha1> <tree sha1>";
 297
 298 int main(int argc, char **argv)
 299 {
 300         char line[1000];
 301         unsigned char old[20], new[20];
 302
 303         for (;;) {
 304                 char *arg;
 305
 306                 argv++;
 307                 argc--;
 308                 arg = *argv;
 309                 if (!arg || *arg != '-')
 310                         break;
 311
 312                 if (!strcmp(arg, "-")) {
 313                         argv++;
 314                         argc--;
 315                         break;
 316                 }
 317                 if (!strcmp(arg, "-r")) {
 318                         recursive = 1;
 319                         continue;
 320                 }
 321                 if (!strcmp(arg, "-p")) {
 322                         recursive = generate_patch = 1;
 323                         continue;
 324                 }
 325                 if (!strcmp(arg, "-z")) {
 326                         line_termination = '\0';
 327                         continue;
 328                 }
 329                 if (!strcmp(arg, "-m")) {
 330                         ignore_merges = 0;
 331                         continue;
 332                 }
 333                 if (!strcmp(arg, "--stdin")) {
 334                         read_stdin = 1;
 335                         continue;
 336                 }
 337                 usage(diff_tree_usage);
 338         }
 339
 340         if (!read_stdin) {
 341                 if (argc < 2 || get_sha1(argv[0], old) || get_sha1(argv[1], new))
 342                         usage(diff_tree_usage);
 343                 argv += 2;
 344                 argc -= 2;
 345         }
 346
 347         if (argc > 0) {
 348                 int i;
 349
 350                 paths = argv;
 351                 nr_paths = argc;
 352                 pathlens = xmalloc(nr_paths * sizeof(int));
 353                 for (i=0; i<nr_paths; i++)
 354                         pathlens[i] = strlen(paths[i]);
 355         }
 356
 357         if (!read_stdin)
 358                 return diff_tree_sha1(old, new, "");
 359
 360         while (fgets(line, sizeof(line), stdin))
 361                 diff_tree_stdin(line);
 362
 363         return 0;
 364 }