Documentation: finishing touches to the new tutorial.
[git.git] / diff-index.c
blob87e10619830ba71654240d424f15cb6db8ac1d65
1 #include "cache.h"
2 #include "diff.h"
4 static int cached_only = 0;
5 static int match_nonexisting = 0;
6 static struct diff_options diff_options;
8 /* A file entry went away or appeared */
9 static void show_file(const char *prefix,
10 struct cache_entry *ce,
11 unsigned char *sha1, unsigned int mode)
13 diff_addremove(&diff_options, prefix[0], ntohl(mode),
14 sha1, ce->name, NULL);
17 static int get_stat_data(struct cache_entry *ce,
18 unsigned char ** sha1p, unsigned int *modep)
20 unsigned char *sha1 = ce->sha1;
21 unsigned int mode = ce->ce_mode;
23 if (!cached_only) {
24 static unsigned char no_sha1[20];
25 int changed;
26 struct stat st;
27 if (lstat(ce->name, &st) < 0) {
28 if (errno == ENOENT && match_nonexisting) {
29 *sha1p = sha1;
30 *modep = mode;
31 return 0;
33 return -1;
35 changed = ce_match_stat(ce, &st);
36 if (changed) {
37 mode = create_ce_mode(st.st_mode);
38 if (!trust_executable_bit &&
39 S_ISREG(mode) && S_ISREG(ce->ce_mode) &&
40 ((mode ^ ce->ce_mode) == 0111))
41 mode = ce->ce_mode;
42 sha1 = no_sha1;
46 *sha1p = sha1;
47 *modep = mode;
48 return 0;
51 static void show_new_file(struct cache_entry *new)
53 unsigned char *sha1;
54 unsigned int mode;
56 /* New file in the index: it might actually be different in
57 * the working copy.
59 if (get_stat_data(new, &sha1, &mode) < 0)
60 return;
62 show_file("+", new, sha1, mode);
65 static int show_modified(struct cache_entry *old,
66 struct cache_entry *new,
67 int report_missing)
69 unsigned int mode, oldmode;
70 unsigned char *sha1;
72 if (get_stat_data(new, &sha1, &mode) < 0) {
73 if (report_missing)
74 show_file("-", old, old->sha1, old->ce_mode);
75 return -1;
78 oldmode = old->ce_mode;
79 if (mode == oldmode && !memcmp(sha1, old->sha1, 20) &&
80 !diff_options.find_copies_harder)
81 return 0;
83 mode = ntohl(mode);
84 oldmode = ntohl(oldmode);
86 diff_change(&diff_options, oldmode, mode,
87 old->sha1, sha1, old->name, NULL);
88 return 0;
91 static int diff_cache(struct cache_entry **ac, int entries, const char **pathspec)
93 while (entries) {
94 struct cache_entry *ce = *ac;
95 int same = (entries > 1) && ce_same_name(ce, ac[1]);
97 if (!ce_path_match(ce, pathspec))
98 goto skip_entry;
100 switch (ce_stage(ce)) {
101 case 0:
102 /* No stage 1 entry? That means it's a new file */
103 if (!same) {
104 show_new_file(ce);
105 break;
107 /* Show difference between old and new */
108 show_modified(ac[1], ce, 1);
109 break;
110 case 1:
111 /* No stage 3 (merge) entry? That means it's been deleted */
112 if (!same) {
113 show_file("-", ce, ce->sha1, ce->ce_mode);
114 break;
116 /* We come here with ce pointing at stage 1
117 * (original tree) and ac[1] pointing at stage
118 * 3 (unmerged). show-modified with
119 * report-missing set to false does not say the
120 * file is deleted but reports true if work
121 * tree does not have it, in which case we
122 * fall through to report the unmerged state.
123 * Otherwise, we show the differences between
124 * the original tree and the work tree.
126 if (!cached_only && !show_modified(ce, ac[1], 0))
127 break;
128 /* fallthru */
129 case 3:
130 diff_unmerge(&diff_options, ce->name);
131 break;
133 default:
134 die("impossible cache entry stage");
137 skip_entry:
139 * Ignore all the different stages for this file,
140 * we've handled the relevant cases now.
142 do {
143 ac++;
144 entries--;
145 } while (entries && ce_same_name(ce, ac[0]));
147 return 0;
151 * This turns all merge entries into "stage 3". That guarantees that
152 * when we read in the new tree (into "stage 1"), we won't lose sight
153 * of the fact that we had unmerged entries.
155 static void mark_merge_entries(void)
157 int i;
158 for (i = 0; i < active_nr; i++) {
159 struct cache_entry *ce = active_cache[i];
160 if (!ce_stage(ce))
161 continue;
162 ce->ce_flags |= htons(CE_STAGEMASK);
166 static const char diff_cache_usage[] =
167 "git-diff-index [-m] [--cached] "
168 "[<common diff options>] <tree-ish> [<path>...]"
169 COMMON_DIFF_OPTIONS_HELP;
171 int main(int argc, const char **argv)
173 const char *tree_name = NULL;
174 unsigned char sha1[20];
175 const char *prefix = setup_git_directory();
176 const char **pathspec = NULL;
177 void *tree;
178 unsigned long size;
179 int ret;
180 int allow_options = 1;
181 int i;
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;
189 if (!allow_options || *arg != '-') {
190 if (tree_name)
191 break;
192 tree_name = arg;
193 continue;
196 if (!strcmp(arg, "--")) {
197 allow_options = 0;
198 continue;
200 if (!strcmp(arg, "-r")) {
201 /* We accept the -r flag just to look like git-diff-tree */
202 continue;
204 diff_opt_cnt = diff_opt_parse(&diff_options, argv + i,
205 argc - i);
206 if (diff_opt_cnt < 0)
207 usage(diff_cache_usage);
208 else if (diff_opt_cnt) {
209 i += diff_opt_cnt - 1;
210 continue;
213 if (!strcmp(arg, "-m")) {
214 match_nonexisting = 1;
215 continue;
217 if (!strcmp(arg, "--cached")) {
218 cached_only = 1;
219 continue;
221 usage(diff_cache_usage);
224 pathspec = get_pathspec(prefix, argv + i);
226 if (diff_setup_done(&diff_options) < 0)
227 usage(diff_cache_usage);
229 if (!tree_name || get_sha1(tree_name, sha1))
230 usage(diff_cache_usage);
232 read_cache();
234 mark_merge_entries();
236 tree = read_object_with_reference(sha1, "tree", &size, NULL);
237 if (!tree)
238 die("bad tree object %s", tree_name);
239 if (read_tree(tree, size, 1, pathspec))
240 die("unable to read tree object %s", tree_name);
242 ret = diff_cache(active_cache, active_nr, pathspec);
244 diffcore_std(&diff_options);
245 diff_flush(&diff_options);
246 return ret;