diff-tree.c

   1 #include <ctype.h>
   2 #include "cache.h"
   3 #include "diff.h"
   4
   5 static int silent = 0;
   6 static int ignore_merges = 1;
   7 static int recursive = 0;
   8 static int read_stdin = 0;
   9 static int line_termination = '\n';
  10 static int generate_patch = 0;
  11 static const char *header = NULL;
  12
  13 // What paths are we interested in?
  14 static int nr_paths = 0;
  15 static char **paths = NULL;
  16 static int *pathlens = NULL;
  17
  18 static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base);
  19
  20 static void update_tree_entry(void **bufp, unsigned long *sizep)
  21 {
  22         void *buf = *bufp;
  23         unsigned long size = *sizep;
  24         int len = strlen(buf) + 1 + 20;
  25
  26         if (size < len)
  27                 die("corrupt tree file");
  28         *bufp = buf + len;
  29         *sizep = size - len;
  30 }
  31
  32 static const unsigned char *extract(void *tree, unsigned long size, const char **pathp, unsigned int *modep)
  33 {
  34         int len = strlen(tree)+1;
  35         const unsigned char *sha1 = tree + len;
  36         const char *path = strchr(tree, ' ');
  37
  38         if (!path || size < len + 20 || sscanf(tree, "%o", modep) != 1)
  39                 die("corrupt tree file");
  40         *pathp = path+1;
  41         return sha1;
  42 }
  43
  44 static char *malloc_base(const char *base, const char *path, int pathlen)
  45 {
  46         int baselen = strlen(base);
  47         char *newbase = xmalloc(baselen + pathlen + 2);
  48         memcpy(newbase, base, baselen);
  49         memcpy(newbase + baselen, path, pathlen);
  50         memcpy(newbase + baselen + pathlen, "/", 2);
  51         return newbase;
  52 }
  53
  54 static void show_file(const char *prefix, void *tree, unsigned long size, const char *base);
  55
  56 /* A whole sub-tree went away or appeared */
  57 static void show_tree(const char *prefix, void *tree, unsigned long size, const char *base)
  58 {
  59         while (size) {
  60                 show_file(prefix, tree, size, base);
  61                 update_tree_entry(&tree, &size);
  62         }
  63 }
  64
  65 /* A file entry went away or appeared */
  66 static void show_file(const char *prefix, void *tree, unsigned long size, const char *base)
  67 {
  68         unsigned mode;
  69         const char *path;
  70         const unsigned char *sha1 = extract(tree, size, &path, &mode);
  71
  72         if (header) {
  73                 printf("%s", header);
  74                 header = NULL;
  75         }
  76
  77         if (silent)
  78                 return;
  79
  80         if (recursive && S_ISDIR(mode)) {
  81                 char type[20];
  82                 unsigned long size;
  83                 char *newbase = malloc_base(base, path, strlen(path));
  84                 void *tree;
  85
  86                 tree = read_sha1_file(sha1, type, &size);
  87                 if (!tree || strcmp(type, "tree"))
  88                         die("corrupt tree sha %s", sha1_to_hex(sha1));
  89
  90                 show_tree(prefix, tree, size, newbase);
  91
  92                 free(tree);
  93                 free(newbase);
  94                 return;
  95         }
  96
  97         if (generate_patch) {
  98                 if (!S_ISDIR(mode))
  99                         diff_addremove(prefix[0], mode, sha1, base, path);
 100         }
 101         else
 102                 printf("%s%06o\t%s\t%s\t%s%s%c", prefix, mode,
 103                        S_ISDIR(mode) ? "tree" : "blob",
 104                        sha1_to_hex(sha1), base, path,
 105                        line_termination);
 106 }
 107
 108 static int compare_tree_entry(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
 109 {
 110         unsigned mode1, mode2;
 111         const char *path1, *path2;
 112         const unsigned char *sha1, *sha2;
 113         int cmp, pathlen1, pathlen2;
 114         char old_sha1_hex[50];
 115
 116         sha1 = extract(tree1, size1, &path1, &mode1);
 117         sha2 = extract(tree2, size2, &path2, &mode2);
 118
 119         pathlen1 = strlen(path1);
 120         pathlen2 = strlen(path2);
 121         cmp = cache_name_compare(path1, pathlen1, path2, pathlen2);
 122         if (cmp < 0) {
 123                 show_file("-", tree1, size1, base);
 124                 return -1;
 125         }
 126         if (cmp > 0) {
 127                 show_file("+", tree2, size2, base);
 128                 return 1;
 129         }
 130         if (!memcmp(sha1, sha2, 20) && mode1 == mode2)
 131                 return 0;
 132
 133         /*
 134          * If the filemode has changed to/from a directory from/to a regular
 135          * file, we need to consider it a remove and an add.
 136          */
 137         if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
 138                 show_file("-", tree1, size1, base);
 139                 show_file("+", tree2, size2, base);
 140                 return 0;
 141         }
 142
 143         if (recursive && S_ISDIR(mode1)) {
 144                 int retval;
 145                 char *newbase = malloc_base(base, path1, pathlen1);
 146                 retval = diff_tree_sha1(sha1, sha2, newbase);
 147                 free(newbase);
 148                 return retval;
 149         }
 150
 151         if (header) {
 152                 printf("%s", header);
 153                 header = NULL;
 154         }
 155         if (silent)
 156                 return 0;
 157
 158         if (generate_patch) {
 159                 if (!S_ISDIR(mode1))
 160                         diff_change(mode1, mode2, sha1, sha2, base, path1);
 161         }
 162         else {
 163                 strcpy(old_sha1_hex, sha1_to_hex(sha1));
 164                 printf("*%06o->%06o\t%s\t%s->%s\t%s%s%c", mode1, mode2,
 165                        S_ISDIR(mode1) ? "tree" : "blob",
 166                        old_sha1_hex, sha1_to_hex(sha2), base, path1,
 167                        line_termination);
 168         }
 169         return 0;
 170 }
 171
 172 static int interesting(void *tree, unsigned long size, const char *base)
 173 {
 174         const char *path;
 175         unsigned mode;
 176         int i;
 177         int baselen, pathlen;
 178
 179         if (!nr_paths)
 180                 return 1;
 181
 182         (void)extract(tree, size, &path, &mode);
 183
 184         pathlen = strlen(path);
 185         baselen = strlen(base);
 186
 187         for (i=0; i < nr_paths; i++) {
 188                 const char *match = paths[i];
 189                 int matchlen = pathlens[i];
 190
 191                 if (baselen >= matchlen) {
 192                         /* If it doesn't match, move along... */
 193                         if (strncmp(base, match, matchlen))
 194                                 continue;
 195
 196                         /* The base is a subdirectory of a path which was specified. */
 197                         return 1;
 198                 }
 199
 200                 /* Does the base match? */
 201                 if (strncmp(base, match, baselen))
 202                         continue;
 203
 204                 match += baselen;
 205                 matchlen -= baselen;
 206
 207                 if (pathlen > matchlen)
 208                         continue;
 209
 210                 if (strncmp(path, match, pathlen))
 211                         continue;
 212
 213                 return 1;
 214         }
 215         return 0; /* No matches */
 216 }
 217
 218 static int diff_tree(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
 219 {
 220         while (size1 | size2) {
 221                 if (nr_paths && size1 && !interesting(tree1, size1, base)) {
 222                         update_tree_entry(&tree1, &size1);
 223                         continue;
 224                 }
 225                 if (nr_paths && size2 && !interesting(tree2, size2, base)) {
 226                         update_tree_entry(&tree2, &size2);
 227                         continue;
 228                 }
 229                 if (!size1) {
 230                         show_file("+", tree2, size2, base);
 231                         update_tree_entry(&tree2, &size2);
 232                         continue;
 233                 }
 234                 if (!size2) {
 235                         show_file("-", tree1, size1, base);
 236                         update_tree_entry(&tree1, &size1);
 237                         continue;
 238                 }
 239                 switch (compare_tree_entry(tree1, size1, tree2, size2, base)) {
 240                 case -1:
 241                         update_tree_entry(&tree1, &size1);
 242                         continue;
 243                 case 0:
 244                         update_tree_entry(&tree1, &size1);
 245                         /* Fallthrough */
 246                 case 1:
 247                         update_tree_entry(&tree2, &size2);
 248                         continue;
 249                 }
 250                 die("diff-tree: internal error");
 251         }
 252         return 0;
 253 }
 254
 255 static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base)
 256 {
 257         void *tree1, *tree2;
 258         unsigned long size1, size2;
 259         int retval;
 260
 261         tree1 = read_object_with_reference(old, "tree", &size1, 0);
 262         if (!tree1)
 263                 die("unable to read source tree (%s)", sha1_to_hex(old));
 264         tree2 = read_object_with_reference(new, "tree", &size2, 0);
 265         if (!tree2)
 266                 die("unable to read destination tree (%s)", sha1_to_hex(new));
 267         retval = diff_tree(tree1, size1, tree2, size2, base);
 268         free(tree1);
 269         free(tree2);
 270         return retval;
 271 }
 272
 273 static int diff_tree_stdin(char *line)
 274 {
 275         int len = strlen(line);
 276         unsigned char commit[20], parent[20];
 277         unsigned long size, offset;
 278         static char this_header[100];
 279         char *buf;
 280
 281         if (!len || line[len-1] != '\n')
 282                 return -1;
 283         line[len-1] = 0;
 284         if (get_sha1_hex(line, commit))
 285                 return -1;
 286         if (isspace(line[40]) && !get_sha1_hex(line+41, parent)) {
 287                 line[40] = 0;
 288                 line[81] = 0;
 289                 sprintf(this_header, "%s (from %s)\n", line, line+41);
 290                 header = this_header;
 291                 return diff_tree_sha1(parent, commit, "");
 292         }
 293         buf = read_object_with_reference(commit, "commit", &size, NULL);
 294         if (!buf)
 295                 return -1;
 296
 297         /* More than one parent? */
 298         if (ignore_merges) {
 299                 if (!memcmp(buf + 46 + 48, "parent ", 7))
 300                         return 0;
 301         }
 302
 303         line[40] = 0;
 304         offset = 46;
 305         while (offset + 48 < size && !memcmp(buf + offset, "parent ", 7)) {
 306                 if (get_sha1_hex(buf + offset + 7, parent))
 307                         return -1;
 308                 sprintf(this_header, "%s (from %s)\n", line, sha1_to_hex(parent));
 309                 header = this_header;
 310                 diff_tree_sha1(parent, commit, "");
 311                 offset += 48;
 312         }
 313         return -1;
 314 }
 315
 316 static char *diff_tree_usage = "diff-tree [-p] [-r] [-z] <tree sha1> <tree sha1>";
 317
 318 int main(int argc, char **argv)
 319 {
 320         char line[1000];
 321         unsigned char old[20], new[20];
 322
 323         for (;;) {
 324                 char *arg;
 325
 326                 argv++;
 327                 argc--;
 328                 arg = *argv;
 329                 if (!arg || *arg != '-')
 330                         break;
 331
 332                 if (!strcmp(arg, "-")) {
 333                         argv++;
 334                         argc--;
 335                         break;
 336                 }
 337                 if (!strcmp(arg, "-r")) {
 338                         recursive = 1;
 339                         continue;
 340                 }
 341                 if (!strcmp(arg, "-p")) {
 342                         recursive = generate_patch = 1;
 343                         continue;
 344                 }
 345                 if (!strcmp(arg, "-z")) {
 346                         line_termination = '\0';
 347                         continue;
 348                 }
 349                 if (!strcmp(arg, "-m")) {
 350                         ignore_merges = 0;
 351                         continue;
 352                 }
 353                 if (!strcmp(arg, "-s")) {
 354                         silent = 1;
 355                         continue;
 356                 }
 357                 if (!strcmp(arg, "--stdin")) {
 358                         read_stdin = 1;
 359                         continue;
 360                 }
 361                 usage(diff_tree_usage);
 362         }
 363
 364         if (!read_stdin) {
 365                 if (argc < 2 || get_sha1(argv[0], old) || get_sha1(argv[1], new))
 366                         usage(diff_tree_usage);
 367                 argv += 2;
 368                 argc -= 2;
 369         }
 370
 371         if (argc > 0) {
 372                 int i;
 373
 374                 paths = argv;
 375                 nr_paths = argc;
 376                 pathlens = xmalloc(nr_paths * sizeof(int));
 377                 for (i=0; i<nr_paths; i++)
 378                         pathlens[i] = strlen(paths[i]);
 379         }
 380
 381         if (!read_stdin)
 382                 return diff_tree_sha1(old, new, "");
 383
 384         while (fgets(line, sizeof(line), stdin))
 385                 diff_tree_stdin(line);
 386
 387         return 0;
 388 }