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