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