builtin-diff.c

   1 /*
   2  * Builtin "git diff"
   3  *
   4  * Copyright (c) 2006 Junio C Hamano
   5  */
   6 #include "cache.h"
   7 #include "commit.h"
   8 #include "blob.h"
   9 #include "tag.h"
  10 #include "diff.h"
  11 #include "diffcore.h"
  12 #include "revision.h"
  13 #include "log-tree.h"
  14 #include "builtin.h"
  15
  16 /* NEEDSWORK: struct object has place for name but we _do_
  17  * know mode when we extracted the blob out of a tree, which
  18  * we currently lose.
  19  */
  20 struct blobinfo {
  21         unsigned char sha1[20];
  22         const char *name;
  23 };
  24
  25 static const char builtin_diff_usage[] =
  26 "diff <options> <rev>{0,2} -- <path>*";
  27
  28 static int builtin_diff_files(struct rev_info *revs,
  29                               int argc, const char **argv)
  30 {
  31         int silent = 0;
  32         while (1 < argc) {
  33                 const char *arg = argv[1];
  34                 if (!strcmp(arg, "--base"))
  35                         revs->max_count = 1;
  36                 else if (!strcmp(arg, "--ours"))
  37                         revs->max_count = 2;
  38                 else if (!strcmp(arg, "--theirs"))
  39                         revs->max_count = 3;
  40                 else if (!strcmp(arg, "-q"))
  41                         silent = 1;
  42                 else if (!strcmp(arg, "--raw"))
  43                         revs->diffopt.output_format = DIFF_FORMAT_RAW;
  44                 else
  45                         usage(builtin_diff_usage);
  46                 argv++; argc--;
  47         }
  48         /*
  49          * Make sure there are NO revision (i.e. pending object) parameter,
  50          * specified rev.max_count is reasonable (0 <= n <= 3), and
  51          * there is no other revision filtering parameter.
  52          */
  53         if (revs->pending_objects ||
  54             revs->min_age != -1 ||
  55             revs->max_age != -1 ||
  56             3 < revs->max_count)
  57                 usage(builtin_diff_usage);
  58         if (revs->max_count < 0 &&
  59             (revs->diffopt.output_format == DIFF_FORMAT_PATCH))
  60                 revs->combine_merges = revs->dense_combined_merges = 1;
  61         /*
  62          * Backward compatibility wart - "diff-files -s" used to
  63          * defeat the common diff option "-s" which asked for
  64          * DIFF_FORMAT_NO_OUTPUT.
  65          */
  66         if (revs->diffopt.output_format == DIFF_FORMAT_NO_OUTPUT)
  67                 revs->diffopt.output_format = DIFF_FORMAT_RAW;
  68         return run_diff_files(revs, silent);
  69 }
  70
  71 static void stuff_change(struct diff_options *opt,
  72                          unsigned old_mode, unsigned new_mode,
  73                          const unsigned char *old_sha1,
  74                          const unsigned char *new_sha1,
  75                          const char *old_name,
  76                          const char *new_name)
  77 {
  78         struct diff_filespec *one, *two;
  79
  80         if (memcmp(null_sha1, old_sha1, 20) &&
  81             memcmp(null_sha1, new_sha1, 20) &&
  82             !memcmp(old_sha1, new_sha1, 20))
  83                 return;
  84
  85         if (opt->reverse_diff) {
  86                 unsigned tmp;
  87                 const unsigned char *tmp_u;
  88                 const char *tmp_c;
  89                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
  90                 tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
  91                 tmp_c = old_name; old_name = new_name; new_name = tmp_c;
  92         }
  93         one = alloc_filespec(old_name);
  94         two = alloc_filespec(new_name);
  95         fill_filespec(one, old_sha1, old_mode);
  96         fill_filespec(two, new_sha1, new_mode);
  97
  98         /* NEEDSWORK: shouldn't this part of diffopt??? */
  99         diff_queue(&diff_queued_diff, one, two);
 100 }
 101
 102 static int builtin_diff_b_f(struct rev_info *revs,
 103                             int argc, const char **argv,
 104                             struct blobinfo *blob,
 105                             const char *path)
 106 {
 107         /* Blob vs file in the working tree*/
 108         struct stat st;
 109
 110         while (1 < argc) {
 111                 const char *arg = argv[1];
 112                 if (!strcmp(arg, "--raw"))
 113                         revs->diffopt.output_format = DIFF_FORMAT_RAW;
 114                 else
 115                         usage(builtin_diff_usage);
 116                 argv++; argc--;
 117         }
 118         if (lstat(path, &st))
 119                 die("'%s': %s", path, strerror(errno));
 120         if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
 121                 die("'%s': not a regular file or symlink", path);
 122         stuff_change(&revs->diffopt,
 123                      canon_mode(st.st_mode), canon_mode(st.st_mode),
 124                      blob[0].sha1, null_sha1,
 125                      blob[0].name, path);
 126         diffcore_std(&revs->diffopt);
 127         diff_flush(&revs->diffopt);
 128         return 0;
 129 }
 130
 131 static int builtin_diff_blobs(struct rev_info *revs,
 132                               int argc, const char **argv,
 133                               struct blobinfo *blob)
 134 {
 135         /* Blobs: the arguments are reversed when setup_revisions()
 136          * picked them up.
 137          */
 138         unsigned mode = canon_mode(S_IFREG | 0644);
 139
 140         while (1 < argc) {
 141                 const char *arg = argv[1];
 142                 if (!strcmp(arg, "--raw"))
 143                         revs->diffopt.output_format = DIFF_FORMAT_RAW;
 144                 else
 145                         usage(builtin_diff_usage);
 146                 argv++; argc--;
 147         }
 148         stuff_change(&revs->diffopt,
 149                      mode, mode,
 150                      blob[1].sha1, blob[0].sha1,
 151                      blob[0].name, blob[0].name);
 152         diffcore_std(&revs->diffopt);
 153         diff_flush(&revs->diffopt);
 154         return 0;
 155 }
 156
 157 static int builtin_diff_index(struct rev_info *revs,
 158                               int argc, const char **argv)
 159 {
 160         int cached = 0;
 161         while (1 < argc) {
 162                 const char *arg = argv[1];
 163                 if (!strcmp(arg, "--cached"))
 164                         cached = 1;
 165                 else if (!strcmp(arg, "--raw"))
 166                         revs->diffopt.output_format = DIFF_FORMAT_RAW;
 167                 else
 168                         usage(builtin_diff_usage);
 169                 argv++; argc--;
 170         }
 171         /*
 172          * Make sure there is one revision (i.e. pending object),
 173          * and there is no revision filtering parameters.
 174          */
 175         if (!revs->pending_objects || revs->pending_objects->next ||
 176             revs->max_count != -1 || revs->min_age != -1 ||
 177             revs->max_age != -1)
 178                 usage(builtin_diff_usage);
 179         return run_diff_index(revs, cached);
 180 }
 181
 182 static int builtin_diff_tree(struct rev_info *revs,
 183                              int argc, const char **argv,
 184                              struct object_list *ent)
 185 {
 186         const unsigned char *(sha1[2]);
 187         int swap = 1;
 188         while (1 < argc) {
 189                 const char *arg = argv[1];
 190                 if (!strcmp(arg, "--raw"))
 191                         revs->diffopt.output_format = DIFF_FORMAT_RAW;
 192                 else
 193                         usage(builtin_diff_usage);
 194                 argv++; argc--;
 195         }
 196
 197         /* We saw two trees, ent[0] and ent[1].
 198          * unless ent[0] is unintesting, they are swapped
 199          */
 200         if (ent[0].item->flags & UNINTERESTING)
 201                 swap = 0;
 202         sha1[swap] = ent[0].item->sha1;
 203         sha1[1-swap] = ent[1].item->sha1;
 204         diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
 205         log_tree_diff_flush(revs);
 206         return 0;
 207 }
 208
 209 static int builtin_diff_combined(struct rev_info *revs,
 210                                  int argc, const char **argv,
 211                                  struct object_list *ent,
 212                                  int ents)
 213 {
 214         const unsigned char (*parent)[20];
 215         int i;
 216
 217         while (1 < argc) {
 218                 const char *arg = argv[1];
 219                 if (!strcmp(arg, "--raw"))
 220                         revs->diffopt.output_format = DIFF_FORMAT_RAW;
 221                 else
 222                         usage(builtin_diff_usage);
 223                 argv++; argc--;
 224         }
 225         if (!revs->dense_combined_merges && !revs->combine_merges)
 226                 revs->dense_combined_merges = revs->combine_merges = 1;
 227         parent = xmalloc(ents * sizeof(*parent));
 228         /* Again, the revs are all reverse */
 229         for (i = 0; i < ents; i++)
 230                 memcpy(parent + i, ent[ents - 1 - i].item->sha1, 20);
 231         diff_tree_combined(parent[0], parent + 1, ents - 1,
 232                            revs->dense_combined_merges, revs);
 233         return 0;
 234 }
 235
 236 static void add_head(struct rev_info *revs)
 237 {
 238         unsigned char sha1[20];
 239         struct object *obj;
 240         if (get_sha1("HEAD", sha1))
 241                 return;
 242         obj = parse_object(sha1);
 243         if (!obj)
 244                 return;
 245         add_object(obj, &revs->pending_objects, NULL, "HEAD");
 246 }
 247
 248 int cmd_diff(int argc, const char **argv, char **envp)
 249 {
 250         struct rev_info rev;
 251         struct object_list *list, ent[100];
 252         int ents = 0, blobs = 0, paths = 0;
 253         const char *path = NULL;
 254         struct blobinfo blob[2];
 255
 256         /*
 257          * We could get N tree-ish in the rev.pending_objects list.
 258          * Also there could be M blobs there, and P pathspecs.
 259          *
 260          * N=0, M=0:
 261          *      cache vs files (diff-files)
 262          * N=0, M=2:
 263          *      compare two random blobs.  P must be zero.
 264          * N=0, M=1, P=1:
 265          *      compare a blob with a working tree file.
 266          *
 267          * N=1, M=0:
 268          *      tree vs cache (diff-index --cached)
 269          *
 270          * N=2, M=0:
 271          *      tree vs tree (diff-tree)
 272          *
 273          * Other cases are errors.
 274          */
 275
 276         git_config(git_diff_config);
 277         init_revisions(&rev);
 278         rev.diffopt.output_format = DIFF_FORMAT_PATCH;
 279
 280         argc = setup_revisions(argc, argv, &rev, NULL);
 281         /* Do we have --cached and not have a pending object, then
 282          * default to HEAD by hand.  Eek.
 283          */
 284         if (!rev.pending_objects) {
 285                 int i;
 286                 for (i = 1; i < argc; i++) {
 287                         const char *arg = argv[i];
 288                         if (!strcmp(arg, "--"))
 289                                 break;
 290                         else if (!strcmp(arg, "--cached")) {
 291                                 add_head(&rev);
 292                                 break;
 293                         }
 294                 }
 295         }
 296
 297         for (list = rev.pending_objects; list; list = list->next) {
 298                 struct object *obj = list->item;
 299                 const char *name = list->name;
 300                 int flags = (obj->flags & UNINTERESTING);
 301                 if (!obj->parsed)
 302                         obj = parse_object(obj->sha1);
 303                 obj = deref_tag(obj, NULL, 0);
 304                 if (!obj)
 305                         die("invalid object '%s' given.", name);
 306                 if (!strcmp(obj->type, commit_type))
 307                         obj = &((struct commit *)obj)->tree->object;
 308                 if (!strcmp(obj->type, tree_type)) {
 309                         if (ARRAY_SIZE(ent) <= ents)
 310                                 die("more than %d trees given: '%s'",
 311                                     (int) ARRAY_SIZE(ent), name);
 312                         obj->flags |= flags;
 313                         ent[ents].item = obj;
 314                         ent[ents].name = name;
 315                         ents++;
 316                         continue;
 317                 }
 318                 if (!strcmp(obj->type, blob_type)) {
 319                         if (2 <= blobs)
 320                                 die("more than two blobs given: '%s'", name);
 321                         memcpy(blob[blobs].sha1, obj->sha1, 20);
 322                         blob[blobs].name = name;
 323                         blobs++;
 324                         continue;
 325
 326                 }
 327                 die("unhandled object '%s' given.", name);
 328         }
 329         if (rev.prune_data) {
 330                 const char **pathspec = rev.prune_data;
 331                 while (*pathspec) {
 332                         if (!path)
 333                                 path = *pathspec;
 334                         paths++;
 335                         pathspec++;
 336                 }
 337         }
 338
 339         /*
 340          * Now, do the arguments look reasonable?
 341          */
 342         if (!ents) {
 343                 switch (blobs) {
 344                 case 0:
 345                         return builtin_diff_files(&rev, argc, argv);
 346                         break;
 347                 case 1:
 348                         if (paths != 1)
 349                                 usage(builtin_diff_usage);
 350                         return builtin_diff_b_f(&rev, argc, argv, blob, path);
 351                         break;
 352                 case 2:
 353                         if (paths)
 354                                 usage(builtin_diff_usage);
 355                         return builtin_diff_blobs(&rev, argc, argv, blob);
 356                         break;
 357                 default:
 358                         usage(builtin_diff_usage);
 359                 }
 360         }
 361         else if (blobs)
 362                 usage(builtin_diff_usage);
 363         else if (ents == 1)
 364                 return builtin_diff_index(&rev, argc, argv);
 365         else if (ents == 2)
 366                 return builtin_diff_tree(&rev, argc, argv, ent);
 367         else
 368                 return builtin_diff_combined(&rev, argc, argv, ent, ents);
 369         usage(builtin_diff_usage);
 370 }