Merge part of pack-thin branch
[git] / diff-index.c
1 #include "cache.h"
2 #include "tree.h"
3 #include "diff.h"
4
5 static int cached_only = 0;
6 static int match_nonexisting = 0;
7 static struct diff_options diff_options;
8
9 /* A file entry went away or appeared */
10 static void show_file(const char *prefix,
11                       struct cache_entry *ce,
12                       unsigned char *sha1, unsigned int mode)
13 {
14         diff_addremove(&diff_options, prefix[0], ntohl(mode),
15                        sha1, ce->name, NULL);
16 }
17
18 static int get_stat_data(struct cache_entry *ce,
19                          unsigned char ** sha1p, unsigned int *modep)
20 {
21         unsigned char *sha1 = ce->sha1;
22         unsigned int mode = ce->ce_mode;
23
24         if (!cached_only) {
25                 static unsigned char no_sha1[20];
26                 int changed;
27                 struct stat st;
28                 if (lstat(ce->name, &st) < 0) {
29                         if (errno == ENOENT && match_nonexisting) {
30                                 *sha1p = sha1;
31                                 *modep = mode;
32                                 return 0;
33                         }
34                         return -1;
35                 }
36                 changed = ce_match_stat(ce, &st, 0);
37                 if (changed) {
38                         mode = create_ce_mode(st.st_mode);
39                         if (!trust_executable_bit &&
40                             S_ISREG(mode) && S_ISREG(ce->ce_mode) &&
41                             ((mode ^ ce->ce_mode) == 0111))
42                                 mode = ce->ce_mode;
43                         sha1 = no_sha1;
44                 }
45         }
46
47         *sha1p = sha1;
48         *modep = mode;
49         return 0;
50 }
51
52 static void show_new_file(struct cache_entry *new)
53 {
54         unsigned char *sha1;
55         unsigned int mode;
56
57         /* New file in the index: it might actually be different in
58          * the working copy.
59          */
60         if (get_stat_data(new, &sha1, &mode) < 0)
61                 return;
62
63         show_file("+", new, sha1, mode);
64 }
65
66 static int show_modified(struct cache_entry *old,
67                          struct cache_entry *new,
68                          int report_missing)
69 {
70         unsigned int mode, oldmode;
71         unsigned char *sha1;
72
73         if (get_stat_data(new, &sha1, &mode) < 0) {
74                 if (report_missing)
75                         show_file("-", old, old->sha1, old->ce_mode);
76                 return -1;
77         }
78
79         oldmode = old->ce_mode;
80         if (mode == oldmode && !memcmp(sha1, old->sha1, 20) &&
81             !diff_options.find_copies_harder)
82                 return 0;
83
84         mode = ntohl(mode);
85         oldmode = ntohl(oldmode);
86
87         diff_change(&diff_options, oldmode, mode,
88                     old->sha1, sha1, old->name, NULL);
89         return 0;
90 }
91
92 static int diff_cache(struct cache_entry **ac, int entries, const char **pathspec)
93 {
94         while (entries) {
95                 struct cache_entry *ce = *ac;
96                 int same = (entries > 1) && ce_same_name(ce, ac[1]);
97
98                 if (!ce_path_match(ce, pathspec))
99                         goto skip_entry;
100
101                 switch (ce_stage(ce)) {
102                 case 0:
103                         /* No stage 1 entry? That means it's a new file */
104                         if (!same) {
105                                 show_new_file(ce);
106                                 break;
107                         }
108                         /* Show difference between old and new */
109                         show_modified(ac[1], ce, 1);
110                         break;
111                 case 1:
112                         /* No stage 3 (merge) entry? That means it's been deleted */
113                         if (!same) {
114                                 show_file("-", ce, ce->sha1, ce->ce_mode);
115                                 break;
116                         }
117                         /* We come here with ce pointing at stage 1
118                          * (original tree) and ac[1] pointing at stage
119                          * 3 (unmerged).  show-modified with
120                          * report-missing set to false does not say the
121                          * file is deleted but reports true if work
122                          * tree does not have it, in which case we
123                          * fall through to report the unmerged state.
124                          * Otherwise, we show the differences between
125                          * the original tree and the work tree.
126                          */
127                         if (!cached_only && !show_modified(ce, ac[1], 0))
128                                 break;
129                         /* fallthru */
130                 case 3:
131                         diff_unmerge(&diff_options, ce->name);
132                         break;
133
134                 default:
135                         die("impossible cache entry stage");
136                 }
137
138 skip_entry:
139                 /*
140                  * Ignore all the different stages for this file,
141                  * we've handled the relevant cases now.
142                  */
143                 do {
144                         ac++;
145                         entries--;
146                 } while (entries && ce_same_name(ce, ac[0]));
147         }
148         return 0;
149 }
150
151 /*
152  * This turns all merge entries into "stage 3". That guarantees that
153  * when we read in the new tree (into "stage 1"), we won't lose sight
154  * of the fact that we had unmerged entries.
155  */
156 static void mark_merge_entries(void)
157 {
158         int i;
159         for (i = 0; i < active_nr; i++) {
160                 struct cache_entry *ce = active_cache[i];
161                 if (!ce_stage(ce))
162                         continue;
163                 ce->ce_flags |= htons(CE_STAGEMASK);
164         }
165 }
166
167 static const char diff_cache_usage[] =
168 "git-diff-index [-m] [--cached] "
169 "[<common diff options>] <tree-ish> [<path>...]"
170 COMMON_DIFF_OPTIONS_HELP;
171
172 int main(int argc, const char **argv)
173 {
174         const char *tree_name = NULL;
175         unsigned char sha1[20];
176         const char *prefix = setup_git_directory();
177         const char **pathspec = NULL;
178         struct tree *tree;
179         int ret;
180         int allow_options = 1;
181         int i;
182
183         git_config(git_diff_config);
184         diff_setup(&diff_options);
185         for (i = 1; i < argc; i++) {
186                 const char *arg = argv[i];
187                 int diff_opt_cnt;
188
189                 if (!allow_options || *arg != '-') {
190                         if (tree_name)
191                                 break;
192                         tree_name = arg;
193                         continue;
194                 }
195                         
196                 if (!strcmp(arg, "--")) {
197                         allow_options = 0;
198                         continue;
199                 }
200                 if (!strcmp(arg, "-r")) {
201                         /* We accept the -r flag just to look like git-diff-tree */
202                         continue;
203                 }
204                 if (!strcmp(arg, "--cc"))
205                         /*
206                          * I _think_ "diff-index --cached HEAD" with an
207                          * unmerged index could show something else
208                          * later, but pretend --cc is the same as -p for
209                          * now.  "git diff" uses --cc by default.
210                          */
211                         argv[i] = arg = "-p";
212                 diff_opt_cnt = diff_opt_parse(&diff_options, argv + i,
213                                               argc - i);
214                 if (diff_opt_cnt < 0)
215                         usage(diff_cache_usage);
216                 else if (diff_opt_cnt) {
217                         i += diff_opt_cnt - 1;
218                         continue;
219                 }
220
221                 if (!strcmp(arg, "-m")) {
222                         match_nonexisting = 1;
223                         continue;
224                 }
225                 if (!strcmp(arg, "--cached")) {
226                         cached_only = 1;
227                         continue;
228                 }
229                 usage(diff_cache_usage);
230         }
231
232         pathspec = get_pathspec(prefix, argv + i);
233
234         if (diff_setup_done(&diff_options) < 0)
235                 usage(diff_cache_usage);
236
237         if (!tree_name || get_sha1(tree_name, sha1))
238                 usage(diff_cache_usage);
239
240         read_cache();
241
242         mark_merge_entries();
243
244         tree = parse_tree_indirect(sha1);
245         if (!tree)
246                 die("bad tree object %s", tree_name);
247         if (read_tree(tree, 1, pathspec))
248                 die("unable to read tree object %s", tree_name);
249
250         ret = diff_cache(active_cache, active_nr, pathspec);
251
252         diffcore_std(&diff_options);
253         diff_flush(&diff_options);
254         return ret;
255 }