196821294e21dcf85a6d3ae9fdd2b54236e29066
   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 */
  20struct blobinfo {
  21        unsigned char sha1[20];
  22        const char *name;
  23};
  24
  25static const char builtin_diff_usage[] =
  26"diff <options> <rev>{0,2} -- <path>*";
  27
  28static 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         * rev.max_count is reasonable (0 <= n <= 3),
  51         * there is no other revision filtering parameters.
  52         */
  53        if (revs->pending_objects ||
  54            revs->min_age != -1 ||
  55            revs->max_age != -1)
  56                usage(builtin_diff_usage);
  57        /*
  58         * Backward compatibility wart - "diff-files -s" used to
  59         * defeat the common diff option "-s" which asked for
  60         * DIFF_FORMAT_NO_OUTPUT.
  61         */
  62        if (revs->diffopt.output_format == DIFF_FORMAT_NO_OUTPUT)
  63                revs->diffopt.output_format = DIFF_FORMAT_RAW;
  64        return run_diff_files(revs, silent);
  65}
  66
  67static void stuff_change(struct diff_options *opt,
  68                         unsigned old_mode, unsigned new_mode,
  69                         const unsigned char *old_sha1,
  70                         const unsigned char *new_sha1,
  71                         const char *old_name,
  72                         const char *new_name)
  73{
  74        struct diff_filespec *one, *two;
  75
  76        if (memcmp(null_sha1, old_sha1, 20) &&
  77            memcmp(null_sha1, new_sha1, 20) &&
  78            !memcmp(old_sha1, new_sha1, 20))
  79                return;
  80
  81        if (opt->reverse_diff) {
  82                unsigned tmp;
  83                const
  84                        const unsigned char *tmp_u;
  85                const char *tmp_c;
  86                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
  87                tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
  88                tmp_c = old_name; old_name = new_name; new_name = tmp_c;
  89        }
  90        one = alloc_filespec(old_name);
  91        two = alloc_filespec(new_name);
  92        fill_filespec(one, old_sha1, old_mode);
  93        fill_filespec(two, new_sha1, new_mode);
  94
  95        /* NEEDSWORK: shouldn't this part of diffopt??? */
  96        diff_queue(&diff_queued_diff, one, two);
  97}
  98
  99static int builtin_diff_b_f(struct rev_info *revs,
 100                            int argc, const char **argv,
 101                            struct blobinfo *blob,
 102                            const char *path)
 103{
 104        /* Blob vs file in the working tree*/
 105        struct stat st;
 106
 107        while (1 < argc) {
 108                const char *arg = argv[1];
 109                if (!strcmp(arg, "--raw"))
 110                        revs->diffopt.output_format = DIFF_FORMAT_RAW;
 111                else
 112                        usage(builtin_diff_usage);
 113                argv++; argc--;
 114        }
 115        if (lstat(path, &st))
 116                die("'%s': %s", path, strerror(errno));
 117        if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
 118                die("'%s': not a regular file or symlink", path);
 119        stuff_change(&revs->diffopt,
 120                     canon_mode(st.st_mode), canon_mode(st.st_mode),
 121                     blob[0].sha1, null_sha1,
 122                     blob[0].name, path);
 123        diffcore_std(&revs->diffopt);
 124        diff_flush(&revs->diffopt);
 125        return 0;
 126}
 127
 128static int builtin_diff_blobs(struct rev_info *revs,
 129                              int argc, const char **argv,
 130                              struct blobinfo *blob)
 131{
 132        /* Blobs */
 133        unsigned mode = canon_mode(S_IFREG | 0644);
 134
 135        while (1 < argc) {
 136                const char *arg = argv[1];
 137                if (!strcmp(arg, "--raw"))
 138                        revs->diffopt.output_format = DIFF_FORMAT_RAW;
 139                else
 140                        usage(builtin_diff_usage);
 141                argv++; argc--;
 142        }
 143        stuff_change(&revs->diffopt,
 144                     mode, mode,
 145                     blob[0].sha1, blob[1].sha1,
 146                     blob[1].name, blob[1].name);
 147        diffcore_std(&revs->diffopt);
 148        diff_flush(&revs->diffopt);
 149        return 0;
 150}
 151
 152static int builtin_diff_index(struct rev_info *revs,
 153                              int argc, const char **argv)
 154{
 155        int cached = 0;
 156        while (1 < argc) {
 157                const char *arg = argv[1];
 158                if (!strcmp(arg, "--cached"))
 159                        cached = 1;
 160                else if (!strcmp(arg, "--raw"))
 161                        revs->diffopt.output_format = DIFF_FORMAT_RAW;
 162                else
 163                        usage(builtin_diff_usage);
 164                argv++; argc--;
 165        }
 166        /*
 167         * Make sure there is one revision (i.e. pending object),
 168         * and there is no revision filtering parameters.
 169         */
 170        if (!revs->pending_objects || revs->pending_objects->next ||
 171            revs->max_count != -1 || revs->min_age != -1 ||
 172            revs->max_age != -1)
 173                usage(builtin_diff_usage);
 174        return run_diff_index(revs, cached);
 175}
 176
 177static int builtin_diff_tree(struct rev_info *revs,
 178                             int argc, const char **argv,
 179                             struct object_list *ent)
 180{
 181        /* We saw two trees, ent[0] and ent[1].
 182         * unless ent[0] is unintesting, they are swapped
 183         */
 184        const unsigned char *(sha1[2]);
 185        int swap = 1;
 186        while (1 < argc) {
 187                const char *arg = argv[1];
 188                if (!strcmp(arg, "--raw"))
 189                        revs->diffopt.output_format = DIFF_FORMAT_RAW;
 190                else
 191                        usage(builtin_diff_usage);
 192                argv++; argc--;
 193        }
 194        if (ent[0].item->flags & UNINTERESTING)
 195                swap = 0;
 196        sha1[swap] = ent[0].item->sha1;
 197        sha1[1-swap] = ent[1].item->sha1;
 198        diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
 199        log_tree_diff_flush(revs);
 200        return 0;
 201}
 202
 203static void add_head(struct rev_info *revs)
 204{
 205        unsigned char sha1[20];
 206        struct object *obj;
 207        if (get_sha1("HEAD", sha1))
 208                return;
 209        obj = parse_object(sha1);
 210        if (!obj)
 211                return;
 212        add_object(obj, &revs->pending_objects, NULL, "HEAD");
 213}
 214
 215int cmd_diff(int argc, const char **argv, char **envp)
 216{
 217        struct rev_info rev;
 218        struct object_list *list, ent[2];
 219        int ents = 0, blobs = 0, paths = 0;
 220        const char *path = NULL;
 221        struct blobinfo blob[2];
 222
 223        /*
 224         * We could get N tree-ish in the rev.pending_objects list.
 225         * Also there could be M blobs there, and P pathspecs.
 226         *
 227         * N=0, M=0:
 228         *      cache vs files (diff-files)
 229         * N=0, M=2:
 230         *      compare two random blobs.  P must be zero.
 231         * N=0, M=1, P=1:
 232         *      compare a blob with a working tree file.
 233         *
 234         * N=1, M=0:
 235         *      tree vs cache (diff-index --cached)
 236         *
 237         * N=2, M=0:
 238         *      tree vs tree (diff-tree)
 239         *
 240         * Other cases are errors.
 241         */
 242        
 243        git_config(git_diff_config);
 244        init_revisions(&rev);
 245        rev.diffopt.output_format = DIFF_FORMAT_PATCH;
 246
 247        argc = setup_revisions(argc, argv, &rev, NULL);
 248        /* Do we have --cached and not have a pending object, then
 249         * default to HEAD by hand.  Eek.
 250         */
 251        if (!rev.pending_objects) {
 252                int i;
 253                for (i = 1; i < argc; i++) {
 254                        const char *arg = argv[i];
 255                        if (!strcmp(arg, "--"))
 256                                break;
 257                        else if (!strcmp(arg, "--cached")) {
 258                                add_head(&rev);
 259                                break;
 260                        }
 261                }
 262        }
 263
 264        for (list = rev.pending_objects; list; list = list->next) {
 265                struct object *obj = list->item;
 266                const char *name = list->name;
 267                int flags = (obj->flags & UNINTERESTING);
 268                if (!obj->parsed)
 269                        obj = parse_object(obj->sha1);
 270                obj = deref_tag(obj, NULL, 0);
 271                if (!obj)
 272                        die("invalid object '%s' given.", name);
 273                if (!strcmp(obj->type, commit_type))
 274                        obj = &((struct commit *)obj)->tree->object;
 275                if (!strcmp(obj->type, tree_type)) {
 276                        if (2 <= ents)
 277                                die("more than two trees given: '%s'", name);
 278                        obj->flags |= flags;
 279                        ent[ents].item = obj;
 280                        ent[ents].name = name;
 281                        ents++;
 282                        continue;
 283                }
 284                if (!strcmp(obj->type, blob_type)) {
 285                        if (2 <= blobs)
 286                                die("more than two blobs given: '%s'", name);
 287                        memcpy(blob[blobs].sha1, obj->sha1, 20);
 288                        blob[blobs].name = name;
 289                        blobs++;
 290                        continue;
 291                        
 292                }
 293                die("unhandled object '%s' given.", name);
 294        }
 295        if (rev.prune_data) {
 296                const char **pathspec = rev.prune_data;
 297                while (*pathspec) {
 298                        if (!path)
 299                                path = *pathspec;
 300                        paths++;
 301                        pathspec++;
 302                }
 303        }
 304
 305        /*
 306         * Now, do the arguments look reasonable?
 307         */
 308        if (!ents) {
 309                switch (blobs) {
 310                case 0:
 311                        return builtin_diff_files(&rev, argc, argv);
 312                        break;
 313                case 1:
 314                        if (paths != 1)
 315                                usage(builtin_diff_usage);
 316                        return builtin_diff_b_f(&rev, argc, argv, blob, path);
 317                        break;
 318                case 2:
 319                        return builtin_diff_blobs(&rev, argc, argv, blob);
 320                        break;
 321                default:
 322                        usage(builtin_diff_usage);
 323                }
 324        }
 325        else if (blobs)
 326                usage(builtin_diff_usage);
 327        else if (ents == 1)
 328                return builtin_diff_index(&rev, argc, argv);
 329        else if (ents == 2)
 330                return builtin_diff_tree(&rev, argc, argv, ent);
 331        usage(builtin_diff_usage);
 332}