read-cache.c: use xcalloc() not calloc()
[git/git.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 }