[PATCH] Diff overhaul, adding half of copy detection.
[git/git.git] / diff-cache.c
... / ...
CommitLineData
1#include "cache.h"
2#include "diff.h"
3
4static int cached_only = 0;
5static int generate_patch = 0;
6static int match_nonexisting = 0;
7static int line_termination = '\n';
8static int detect_rename = 0;
9static int reverse_diff = 0;
10static int diff_score_opt = 0;
11
12/* A file entry went away or appeared */
13static void show_file(const char *prefix, struct cache_entry *ce, unsigned char *sha1, unsigned int mode)
14{
15 diff_addremove(prefix[0], ntohl(mode), sha1, ce->name, NULL);
16}
17
18static int get_stat_data(struct cache_entry *ce, unsigned char **sha1p, unsigned int *modep)
19{
20 unsigned char *sha1 = ce->sha1;
21 unsigned int mode = ce->ce_mode;
22
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;
32 }
33 return -1;
34 }
35 changed = ce_match_stat(ce, &st);
36 if (changed) {
37 mode = create_ce_mode(st.st_mode);
38 sha1 = no_sha1;
39 }
40 }
41
42 *sha1p = sha1;
43 *modep = mode;
44 return 0;
45}
46
47static void show_new_file(struct cache_entry *new)
48{
49 unsigned char *sha1;
50 unsigned int mode;
51
52 /* New file in the index: it might actually be different in the working copy */
53 if (get_stat_data(new, &sha1, &mode) < 0)
54 return;
55
56 show_file("+", new, sha1, mode);
57}
58
59static int show_modified(struct cache_entry *old,
60 struct cache_entry *new,
61 int report_missing)
62{
63 unsigned int mode, oldmode;
64 unsigned char *sha1;
65
66 if (get_stat_data(new, &sha1, &mode) < 0) {
67 if (report_missing)
68 show_file("-", old, old->sha1, old->ce_mode);
69 return -1;
70 }
71
72 oldmode = old->ce_mode;
73 if (mode == oldmode && !memcmp(sha1, old->sha1, 20))
74 return 0;
75
76 mode = ntohl(mode);
77 oldmode = ntohl(oldmode);
78
79 diff_change(oldmode, mode,
80 old->sha1, sha1, old->name, NULL);
81 return 0;
82}
83
84static int diff_cache(struct cache_entry **ac, int entries)
85{
86 while (entries) {
87 struct cache_entry *ce = *ac;
88 int same = (entries > 1) && ce_same_name(ce, ac[1]);
89
90 switch (ce_stage(ce)) {
91 case 0:
92 /* No stage 1 entry? That means it's a new file */
93 if (!same) {
94 show_new_file(ce);
95 break;
96 }
97 /* Show difference between old and new */
98 show_modified(ac[1], ce, 1);
99 break;
100 case 1:
101 /* No stage 3 (merge) entry? That means it's been deleted */
102 if (!same) {
103 show_file("-", ce, ce->sha1, ce->ce_mode);
104 break;
105 }
106 /* We come here with ce pointing at stage 1
107 * (original tree) and ac[1] pointing at stage
108 * 3 (unmerged). show-modified with
109 * report-mising set to false does not say the
110 * file is deleted but reports true if work
111 * tree does not have it, in which case we
112 * fall through to report the unmerged state.
113 * Otherwise, we show the differences between
114 * the original tree and the work tree.
115 */
116 if (!cached_only && !show_modified(ce, ac[1], 0))
117 break;
118 /* fallthru */
119 case 3:
120 diff_unmerge(ce->name);
121 break;
122
123 default:
124 die("impossible cache entry stage");
125 }
126
127 /*
128 * Ignore all the different stages for this file,
129 * we've handled the relevant cases now.
130 */
131 do {
132 ac++;
133 entries--;
134 } while (entries && ce_same_name(ce, ac[0]));
135 }
136 return 0;
137}
138
139/*
140 * This turns all merge entries into "stage 3". That guarantees that
141 * when we read in the new tree (into "stage 1"), we won't lose sight
142 * of the fact that we had unmerged entries.
143 */
144static void mark_merge_entries(void)
145{
146 int i;
147 for (i = 0; i < active_nr; i++) {
148 struct cache_entry *ce = active_cache[i];
149 if (!ce_stage(ce))
150 continue;
151 ce->ce_flags |= htons(CE_STAGEMASK);
152 }
153}
154
155static char *diff_cache_usage =
156"git-diff-cache [-p] [-r] [-z] [-m] [-M] [-C] [-R] [--cached] <tree-ish>";
157
158int main(int argc, char **argv)
159{
160 unsigned char tree_sha1[20];
161 void *tree;
162 unsigned long size;
163 int ret;
164
165 read_cache();
166 while (argc > 2) {
167 char *arg = argv[1];
168 argv++;
169 argc--;
170 if (!strcmp(arg, "-r")) {
171 /* We accept the -r flag just to look like git-diff-tree */
172 continue;
173 }
174 if (!strcmp(arg, "-p")) {
175 generate_patch = 1;
176 continue;
177 }
178 if (!strncmp(arg, "-M", 2)) {
179 generate_patch = detect_rename = 1;
180 diff_score_opt = diff_scoreopt_parse(arg);
181 continue;
182 }
183 if (!strncmp(arg, "-C", 2)) {
184 generate_patch = 1;
185 detect_rename = 2;
186 diff_score_opt = diff_scoreopt_parse(arg);
187 continue;
188 }
189 if (!strcmp(arg, "-z")) {
190 line_termination = '\0';
191 continue;
192 }
193 if (!strcmp(arg, "-R")) {
194 reverse_diff = 1;
195 continue;
196 }
197 if (!strcmp(arg, "-m")) {
198 match_nonexisting = 1;
199 continue;
200 }
201 if (!strcmp(arg, "--cached")) {
202 cached_only = 1;
203 continue;
204 }
205 usage(diff_cache_usage);
206 }
207
208 if (argc != 2 || get_sha1(argv[1], tree_sha1))
209 usage(diff_cache_usage);
210
211 diff_setup(detect_rename, diff_score_opt, reverse_diff,
212 (generate_patch ? -1 : line_termination),
213 NULL, 0);
214
215 mark_merge_entries();
216
217 tree = read_object_with_reference(tree_sha1, "tree", &size, NULL);
218 if (!tree)
219 die("bad tree object %s", argv[1]);
220 if (read_tree(tree, size, 1))
221 die("unable to read tree object %s", argv[1]);
222
223 ret = diff_cache(active_cache, active_nr);
224 diff_flush();
225 return ret;
226}