Start preparing for 1.8.4.2
[alt-git.git] / tree-diff.c
blobba01563a0241041cb401cfb03495e6067847248e
1 /*
2 * Helper functions for tree diff generation
3 */
4 #include "cache.h"
5 #include "diff.h"
6 #include "diffcore.h"
7 #include "tree.h"
9 static void show_entry(struct diff_options *opt, const char *prefix,
10 struct tree_desc *desc, struct strbuf *base);
12 static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2,
13 struct strbuf *base, struct diff_options *opt)
15 unsigned mode1, mode2;
16 const char *path1, *path2;
17 const unsigned char *sha1, *sha2;
18 int cmp, pathlen1, pathlen2;
19 int old_baselen = base->len;
21 sha1 = tree_entry_extract(t1, &path1, &mode1);
22 sha2 = tree_entry_extract(t2, &path2, &mode2);
24 pathlen1 = tree_entry_len(&t1->entry);
25 pathlen2 = tree_entry_len(&t2->entry);
26 cmp = base_name_compare(path1, pathlen1, mode1, path2, pathlen2, mode2);
27 if (cmp < 0) {
28 show_entry(opt, "-", t1, base);
29 return -1;
31 if (cmp > 0) {
32 show_entry(opt, "+", t2, base);
33 return 1;
35 if (!DIFF_OPT_TST(opt, FIND_COPIES_HARDER) && !hashcmp(sha1, sha2) && mode1 == mode2)
36 return 0;
39 * If the filemode has changed to/from a directory from/to a regular
40 * file, we need to consider it a remove and an add.
42 if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
43 show_entry(opt, "-", t1, base);
44 show_entry(opt, "+", t2, base);
45 return 0;
48 strbuf_add(base, path1, pathlen1);
49 if (DIFF_OPT_TST(opt, RECURSIVE) && S_ISDIR(mode1)) {
50 if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE)) {
51 opt->change(opt, mode1, mode2,
52 sha1, sha2, 1, 1, base->buf, 0, 0);
54 strbuf_addch(base, '/');
55 diff_tree_sha1(sha1, sha2, base->buf, opt);
56 } else {
57 opt->change(opt, mode1, mode2, sha1, sha2, 1, 1, base->buf, 0, 0);
59 strbuf_setlen(base, old_baselen);
60 return 0;
63 /* A whole sub-tree went away or appeared */
64 static void show_tree(struct diff_options *opt, const char *prefix,
65 struct tree_desc *desc, struct strbuf *base)
67 enum interesting match = entry_not_interesting;
68 for (; desc->size; update_tree_entry(desc)) {
69 if (match != all_entries_interesting) {
70 match = tree_entry_interesting(&desc->entry, base, 0,
71 &opt->pathspec);
72 if (match == all_entries_not_interesting)
73 break;
74 if (match == entry_not_interesting)
75 continue;
77 show_entry(opt, prefix, desc, base);
81 /* A file entry went away or appeared */
82 static void show_entry(struct diff_options *opt, const char *prefix,
83 struct tree_desc *desc, struct strbuf *base)
85 unsigned mode;
86 const char *path;
87 const unsigned char *sha1 = tree_entry_extract(desc, &path, &mode);
88 int pathlen = tree_entry_len(&desc->entry);
89 int old_baselen = base->len;
91 strbuf_add(base, path, pathlen);
92 if (DIFF_OPT_TST(opt, RECURSIVE) && S_ISDIR(mode)) {
93 enum object_type type;
94 struct tree_desc inner;
95 void *tree;
96 unsigned long size;
98 tree = read_sha1_file(sha1, &type, &size);
99 if (!tree || type != OBJ_TREE)
100 die("corrupt tree sha %s", sha1_to_hex(sha1));
102 if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE))
103 opt->add_remove(opt, *prefix, mode, sha1, 1, base->buf, 0);
105 strbuf_addch(base, '/');
107 init_tree_desc(&inner, tree, size);
108 show_tree(opt, prefix, &inner, base);
109 free(tree);
110 } else
111 opt->add_remove(opt, prefix[0], mode, sha1, 1, base->buf, 0);
113 strbuf_setlen(base, old_baselen);
116 static void skip_uninteresting(struct tree_desc *t, struct strbuf *base,
117 struct diff_options *opt,
118 enum interesting *match)
120 while (t->size) {
121 *match = tree_entry_interesting(&t->entry, base, 0, &opt->pathspec);
122 if (*match) {
123 if (*match == all_entries_not_interesting)
124 t->size = 0;
125 break;
127 update_tree_entry(t);
131 int diff_tree(struct tree_desc *t1, struct tree_desc *t2,
132 const char *base_str, struct diff_options *opt)
134 struct strbuf base;
135 int baselen = strlen(base_str);
136 enum interesting t1_match = entry_not_interesting;
137 enum interesting t2_match = entry_not_interesting;
139 /* Enable recursion indefinitely */
140 opt->pathspec.recursive = DIFF_OPT_TST(opt, RECURSIVE);
141 opt->pathspec.max_depth = -1;
143 strbuf_init(&base, PATH_MAX);
144 strbuf_add(&base, base_str, baselen);
146 for (;;) {
147 if (diff_can_quit_early(opt))
148 break;
149 if (opt->pathspec.nr) {
150 skip_uninteresting(t1, &base, opt, &t1_match);
151 skip_uninteresting(t2, &base, opt, &t2_match);
153 if (!t1->size) {
154 if (!t2->size)
155 break;
156 show_entry(opt, "+", t2, &base);
157 update_tree_entry(t2);
158 continue;
160 if (!t2->size) {
161 show_entry(opt, "-", t1, &base);
162 update_tree_entry(t1);
163 continue;
165 switch (compare_tree_entry(t1, t2, &base, opt)) {
166 case -1:
167 update_tree_entry(t1);
168 continue;
169 case 0:
170 update_tree_entry(t1);
171 /* Fallthrough */
172 case 1:
173 update_tree_entry(t2);
174 continue;
176 die("git diff-tree: internal error");
179 strbuf_release(&base);
180 return 0;
184 * Does it look like the resulting diff might be due to a rename?
185 * - single entry
186 * - not a valid previous file
188 static inline int diff_might_be_rename(void)
190 return diff_queued_diff.nr == 1 &&
191 !DIFF_FILE_VALID(diff_queued_diff.queue[0]->one);
194 static void try_to_follow_renames(struct tree_desc *t1, struct tree_desc *t2, const char *base, struct diff_options *opt)
196 struct diff_options diff_opts;
197 struct diff_queue_struct *q = &diff_queued_diff;
198 struct diff_filepair *choice;
199 const char *paths[1];
200 int i;
202 /* Remove the file creation entry from the diff queue, and remember it */
203 choice = q->queue[0];
204 q->nr = 0;
206 diff_setup(&diff_opts);
207 DIFF_OPT_SET(&diff_opts, RECURSIVE);
208 DIFF_OPT_SET(&diff_opts, FIND_COPIES_HARDER);
209 diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
210 diff_opts.single_follow = opt->pathspec.raw[0];
211 diff_opts.break_opt = opt->break_opt;
212 diff_opts.rename_score = opt->rename_score;
213 paths[0] = NULL;
214 diff_tree_setup_paths(paths, &diff_opts);
215 diff_setup_done(&diff_opts);
216 diff_tree(t1, t2, base, &diff_opts);
217 diffcore_std(&diff_opts);
218 diff_tree_release_paths(&diff_opts);
220 /* Go through the new set of filepairing, and see if we find a more interesting one */
221 opt->found_follow = 0;
222 for (i = 0; i < q->nr; i++) {
223 struct diff_filepair *p = q->queue[i];
226 * Found a source? Not only do we use that for the new
227 * diff_queued_diff, we will also use that as the path in
228 * the future!
230 if ((p->status == 'R' || p->status == 'C') &&
231 !strcmp(p->two->path, opt->pathspec.raw[0])) {
232 /* Switch the file-pairs around */
233 q->queue[i] = choice;
234 choice = p;
236 /* Update the path we use from now on.. */
237 diff_tree_release_paths(opt);
238 opt->pathspec.raw[0] = xstrdup(p->one->path);
239 diff_tree_setup_paths(opt->pathspec.raw, opt);
242 * The caller expects us to return a set of vanilla
243 * filepairs to let a later call to diffcore_std()
244 * it makes to sort the renames out (among other
245 * things), but we already have found renames
246 * ourselves; signal diffcore_std() not to muck with
247 * rename information.
249 opt->found_follow = 1;
250 break;
255 * Then, discard all the non-relevant file pairs...
257 for (i = 0; i < q->nr; i++) {
258 struct diff_filepair *p = q->queue[i];
259 diff_free_filepair(p);
263 * .. and re-instate the one we want (which might be either the
264 * original one, or the rename/copy we found)
266 q->queue[0] = choice;
267 q->nr = 1;
270 int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base, struct diff_options *opt)
272 void *tree1, *tree2;
273 struct tree_desc t1, t2;
274 unsigned long size1, size2;
275 int retval;
277 tree1 = read_object_with_reference(old, tree_type, &size1, NULL);
278 if (!tree1)
279 die("unable to read source tree (%s)", sha1_to_hex(old));
280 tree2 = read_object_with_reference(new, tree_type, &size2, NULL);
281 if (!tree2)
282 die("unable to read destination tree (%s)", sha1_to_hex(new));
283 init_tree_desc(&t1, tree1, size1);
284 init_tree_desc(&t2, tree2, size2);
285 retval = diff_tree(&t1, &t2, base, opt);
286 if (!*base && DIFF_OPT_TST(opt, FOLLOW_RENAMES) && diff_might_be_rename()) {
287 init_tree_desc(&t1, tree1, size1);
288 init_tree_desc(&t2, tree2, size2);
289 try_to_follow_renames(&t1, &t2, base, opt);
291 free(tree1);
292 free(tree2);
293 return retval;
296 int diff_root_tree_sha1(const unsigned char *new, const char *base, struct diff_options *opt)
298 int retval;
299 void *tree;
300 unsigned long size;
301 struct tree_desc empty, real;
303 tree = read_object_with_reference(new, tree_type, &size, NULL);
304 if (!tree)
305 die("unable to read root tree (%s)", sha1_to_hex(new));
306 init_tree_desc(&real, tree, size);
308 init_tree_desc(&empty, "", 0);
309 retval = diff_tree(&empty, &real, base, opt);
310 free(tree);
311 return retval;
314 void diff_tree_release_paths(struct diff_options *opt)
316 free_pathspec(&opt->pathspec);
319 void diff_tree_setup_paths(const char **p, struct diff_options *opt)
321 init_pathspec(&opt->pathspec, p);