Convert memset(hash,0,20) to hashclr(hash).
[git/git.git] / diff-lib.c
1 /*
2 * Copyright (C) 2005 Junio C Hamano
3 */
4 #include "cache.h"
5 #include "quote.h"
6 #include "commit.h"
7 #include "diff.h"
8 #include "diffcore.h"
9 #include "revision.h"
10
11 /*
12 * diff-files
13 */
14
15 int run_diff_files(struct rev_info *revs, int silent_on_removed)
16 {
17 int entries, i;
18 int diff_unmerged_stage = revs->max_count;
19
20 if (diff_unmerged_stage < 0)
21 diff_unmerged_stage = 2;
22 entries = read_cache();
23 if (entries < 0) {
24 perror("read_cache");
25 return -1;
26 }
27 for (i = 0; i < entries; i++) {
28 struct stat st;
29 unsigned int oldmode, newmode;
30 struct cache_entry *ce = active_cache[i];
31 int changed;
32
33 if (!ce_path_match(ce, revs->prune_data))
34 continue;
35
36 if (ce_stage(ce)) {
37 struct combine_diff_path *dpath;
38 int num_compare_stages = 0;
39 size_t path_len;
40
41 path_len = ce_namelen(ce);
42
43 dpath = xmalloc (combine_diff_path_size (5, path_len));
44 dpath->path = (char *) &(dpath->parent[5]);
45
46 dpath->next = NULL;
47 dpath->len = path_len;
48 memcpy(dpath->path, ce->name, path_len);
49 dpath->path[path_len] = '\0';
50 dpath->mode = 0;
51 hashclr(dpath->sha1);
52 memset(&(dpath->parent[0]), 0,
53 sizeof(struct combine_diff_parent)*5);
54
55 while (i < entries) {
56 struct cache_entry *nce = active_cache[i];
57 int stage;
58
59 if (strcmp(ce->name, nce->name))
60 break;
61
62 /* Stage #2 (ours) is the first parent,
63 * stage #3 (theirs) is the second.
64 */
65 stage = ce_stage(nce);
66 if (2 <= stage) {
67 int mode = ntohl(nce->ce_mode);
68 num_compare_stages++;
69 hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
70 dpath->parent[stage-2].mode =
71 canon_mode(mode);
72 dpath->parent[stage-2].status =
73 DIFF_STATUS_MODIFIED;
74 }
75
76 /* diff against the proper unmerged stage */
77 if (stage == diff_unmerged_stage)
78 ce = nce;
79 i++;
80 }
81 /*
82 * Compensate for loop update
83 */
84 i--;
85
86 if (revs->combine_merges && num_compare_stages == 2) {
87 show_combined_diff(dpath, 2,
88 revs->dense_combined_merges,
89 revs);
90 free(dpath);
91 continue;
92 }
93 free(dpath);
94 dpath = NULL;
95
96 /*
97 * Show the diff for the 'ce' if we found the one
98 * from the desired stage.
99 */
100 diff_unmerge(&revs->diffopt, ce->name);
101 if (ce_stage(ce) != diff_unmerged_stage)
102 continue;
103 }
104
105 if (lstat(ce->name, &st) < 0) {
106 if (errno != ENOENT && errno != ENOTDIR) {
107 perror(ce->name);
108 continue;
109 }
110 if (silent_on_removed)
111 continue;
112 diff_addremove(&revs->diffopt, '-', ntohl(ce->ce_mode),
113 ce->sha1, ce->name, NULL);
114 continue;
115 }
116 changed = ce_match_stat(ce, &st, 0);
117 if (!changed && !revs->diffopt.find_copies_harder)
118 continue;
119 oldmode = ntohl(ce->ce_mode);
120
121 newmode = canon_mode(st.st_mode);
122 if (!trust_executable_bit &&
123 S_ISREG(newmode) && S_ISREG(oldmode) &&
124 ((newmode ^ oldmode) == 0111))
125 newmode = oldmode;
126 diff_change(&revs->diffopt, oldmode, newmode,
127 ce->sha1, (changed ? null_sha1 : ce->sha1),
128 ce->name, NULL);
129
130 }
131 diffcore_std(&revs->diffopt);
132 diff_flush(&revs->diffopt);
133 return 0;
134 }
135
136 /*
137 * diff-index
138 */
139
140 /* A file entry went away or appeared */
141 static void diff_index_show_file(struct rev_info *revs,
142 const char *prefix,
143 struct cache_entry *ce,
144 unsigned char *sha1, unsigned int mode)
145 {
146 diff_addremove(&revs->diffopt, prefix[0], ntohl(mode),
147 sha1, ce->name, NULL);
148 }
149
150 static int get_stat_data(struct cache_entry *ce,
151 unsigned char **sha1p,
152 unsigned int *modep,
153 int cached, int match_missing)
154 {
155 unsigned char *sha1 = ce->sha1;
156 unsigned int mode = ce->ce_mode;
157
158 if (!cached) {
159 static unsigned char no_sha1[20];
160 int changed;
161 struct stat st;
162 if (lstat(ce->name, &st) < 0) {
163 if (errno == ENOENT && match_missing) {
164 *sha1p = sha1;
165 *modep = mode;
166 return 0;
167 }
168 return -1;
169 }
170 changed = ce_match_stat(ce, &st, 0);
171 if (changed) {
172 mode = create_ce_mode(st.st_mode);
173 if (!trust_executable_bit && S_ISREG(st.st_mode))
174 mode = ce->ce_mode;
175 sha1 = no_sha1;
176 }
177 }
178
179 *sha1p = sha1;
180 *modep = mode;
181 return 0;
182 }
183
184 static void show_new_file(struct rev_info *revs,
185 struct cache_entry *new,
186 int cached, int match_missing)
187 {
188 unsigned char *sha1;
189 unsigned int mode;
190
191 /* New file in the index: it might actually be different in
192 * the working copy.
193 */
194 if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0)
195 return;
196
197 diff_index_show_file(revs, "+", new, sha1, mode);
198 }
199
200 static int show_modified(struct rev_info *revs,
201 struct cache_entry *old,
202 struct cache_entry *new,
203 int report_missing,
204 int cached, int match_missing)
205 {
206 unsigned int mode, oldmode;
207 unsigned char *sha1;
208
209 if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0) {
210 if (report_missing)
211 diff_index_show_file(revs, "-", old,
212 old->sha1, old->ce_mode);
213 return -1;
214 }
215
216 oldmode = old->ce_mode;
217 if (mode == oldmode && !hashcmp(sha1, old->sha1) &&
218 !revs->diffopt.find_copies_harder)
219 return 0;
220
221 mode = ntohl(mode);
222 oldmode = ntohl(oldmode);
223
224 diff_change(&revs->diffopt, oldmode, mode,
225 old->sha1, sha1, old->name, NULL);
226 return 0;
227 }
228
229 static int diff_cache(struct rev_info *revs,
230 struct cache_entry **ac, int entries,
231 const char **pathspec,
232 int cached, int match_missing)
233 {
234 while (entries) {
235 struct cache_entry *ce = *ac;
236 int same = (entries > 1) && ce_same_name(ce, ac[1]);
237
238 if (!ce_path_match(ce, pathspec))
239 goto skip_entry;
240
241 switch (ce_stage(ce)) {
242 case 0:
243 /* No stage 1 entry? That means it's a new file */
244 if (!same) {
245 show_new_file(revs, ce, cached, match_missing);
246 break;
247 }
248 /* Show difference between old and new */
249 show_modified(revs,ac[1], ce, 1,
250 cached, match_missing);
251 break;
252 case 1:
253 /* No stage 3 (merge) entry?
254 * That means it's been deleted.
255 */
256 if (!same) {
257 diff_index_show_file(revs, "-", ce,
258 ce->sha1, ce->ce_mode);
259 break;
260 }
261 /* We come here with ce pointing at stage 1
262 * (original tree) and ac[1] pointing at stage
263 * 3 (unmerged). show-modified with
264 * report-missing set to false does not say the
265 * file is deleted but reports true if work
266 * tree does not have it, in which case we
267 * fall through to report the unmerged state.
268 * Otherwise, we show the differences between
269 * the original tree and the work tree.
270 */
271 if (!cached &&
272 !show_modified(revs, ce, ac[1], 0,
273 cached, match_missing))
274 break;
275 /* fallthru */
276 case 3:
277 diff_unmerge(&revs->diffopt, ce->name);
278 break;
279
280 default:
281 die("impossible cache entry stage");
282 }
283
284 skip_entry:
285 /*
286 * Ignore all the different stages for this file,
287 * we've handled the relevant cases now.
288 */
289 do {
290 ac++;
291 entries--;
292 } while (entries && ce_same_name(ce, ac[0]));
293 }
294 return 0;
295 }
296
297 /*
298 * This turns all merge entries into "stage 3". That guarantees that
299 * when we read in the new tree (into "stage 1"), we won't lose sight
300 * of the fact that we had unmerged entries.
301 */
302 static void mark_merge_entries(void)
303 {
304 int i;
305 for (i = 0; i < active_nr; i++) {
306 struct cache_entry *ce = active_cache[i];
307 if (!ce_stage(ce))
308 continue;
309 ce->ce_flags |= htons(CE_STAGEMASK);
310 }
311 }
312
313 int run_diff_index(struct rev_info *revs, int cached)
314 {
315 int ret;
316 struct object *ent;
317 struct tree *tree;
318 const char *tree_name;
319 int match_missing = 0;
320
321 /*
322 * Backward compatibility wart - "diff-index -m" does
323 * not mean "do not ignore merges", but totally different.
324 */
325 if (!revs->ignore_merges)
326 match_missing = 1;
327
328 if (read_cache() < 0) {
329 perror("read_cache");
330 return -1;
331 }
332 mark_merge_entries();
333
334 ent = revs->pending.objects[0].item;
335 tree_name = revs->pending.objects[0].name;
336 tree = parse_tree_indirect(ent->sha1);
337 if (!tree)
338 return error("bad tree object %s", tree_name);
339 if (read_tree(tree, 1, revs->prune_data))
340 return error("unable to read tree object %s", tree_name);
341 ret = diff_cache(revs, active_cache, active_nr, revs->prune_data,
342 cached, match_missing);
343 diffcore_std(&revs->diffopt);
344 diff_flush(&revs->diffopt);
345 return ret;
346 }