[PATCH] Prepare diffcore interface for diff-tree header supression.
[git/git.git] / diff-cache.c
1 #include "cache.h"
2 #include "diff.h"
3
4 static int cached_only = 0;
5 static int generate_patch = 0;
6 static int match_nonexisting = 0;
7 static int line_termination = '\n';
8 static int detect_rename = 0;
9 static int reverse_diff = 0;
10 static int diff_score_opt = 0;
11 static const char *pickaxe = NULL;
12
13 /* A file entry went away or appeared */
14 static void show_file(const char *prefix, struct cache_entry *ce, unsigned char *sha1, unsigned int mode)
15 {
16 diff_addremove(prefix[0], ntohl(mode), sha1, ce->name, NULL);
17 }
18
19 static int get_stat_data(struct cache_entry *ce, 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);
37 if (changed) {
38 mode = create_ce_mode(st.st_mode);
39 sha1 = no_sha1;
40 }
41 }
42
43 *sha1p = sha1;
44 *modep = mode;
45 return 0;
46 }
47
48 static void show_new_file(struct cache_entry *new)
49 {
50 unsigned char *sha1;
51 unsigned int mode;
52
53 /* New file in the index: it might actually be different in the working copy */
54 if (get_stat_data(new, &sha1, &mode) < 0)
55 return;
56
57 show_file("+", new, sha1, mode);
58 }
59
60 static int show_modified(struct cache_entry *old,
61 struct cache_entry *new,
62 int report_missing)
63 {
64 unsigned int mode, oldmode;
65 unsigned char *sha1;
66
67 if (get_stat_data(new, &sha1, &mode) < 0) {
68 if (report_missing)
69 show_file("-", old, old->sha1, old->ce_mode);
70 return -1;
71 }
72
73 oldmode = old->ce_mode;
74 if (mode == oldmode && !memcmp(sha1, old->sha1, 20) &&
75 detect_rename < 2)
76 return 0;
77
78 mode = ntohl(mode);
79 oldmode = ntohl(oldmode);
80
81 diff_change(oldmode, mode,
82 old->sha1, sha1, old->name, NULL);
83 return 0;
84 }
85
86 static int diff_cache(struct cache_entry **ac, int entries)
87 {
88 while (entries) {
89 struct cache_entry *ce = *ac;
90 int same = (entries > 1) && ce_same_name(ce, ac[1]);
91
92 switch (ce_stage(ce)) {
93 case 0:
94 /* No stage 1 entry? That means it's a new file */
95 if (!same) {
96 show_new_file(ce);
97 break;
98 }
99 /* Show difference between old and new */
100 show_modified(ac[1], ce, 1);
101 break;
102 case 1:
103 /* No stage 3 (merge) entry? That means it's been deleted */
104 if (!same) {
105 show_file("-", ce, ce->sha1, ce->ce_mode);
106 break;
107 }
108 /* We come here with ce pointing at stage 1
109 * (original tree) and ac[1] pointing at stage
110 * 3 (unmerged). show-modified with
111 * report-mising set to false does not say the
112 * file is deleted but reports true if work
113 * tree does not have it, in which case we
114 * fall through to report the unmerged state.
115 * Otherwise, we show the differences between
116 * the original tree and the work tree.
117 */
118 if (!cached_only && !show_modified(ce, ac[1], 0))
119 break;
120 /* fallthru */
121 case 3:
122 diff_unmerge(ce->name);
123 break;
124
125 default:
126 die("impossible cache entry stage");
127 }
128
129 /*
130 * Ignore all the different stages for this file,
131 * we've handled the relevant cases now.
132 */
133 do {
134 ac++;
135 entries--;
136 } while (entries && ce_same_name(ce, ac[0]));
137 }
138 return 0;
139 }
140
141 /*
142 * This turns all merge entries into "stage 3". That guarantees that
143 * when we read in the new tree (into "stage 1"), we won't lose sight
144 * of the fact that we had unmerged entries.
145 */
146 static void mark_merge_entries(void)
147 {
148 int i;
149 for (i = 0; i < active_nr; i++) {
150 struct cache_entry *ce = active_cache[i];
151 if (!ce_stage(ce))
152 continue;
153 ce->ce_flags |= htons(CE_STAGEMASK);
154 }
155 }
156
157 static char *diff_cache_usage =
158 "git-diff-cache [-p] [-r] [-z] [-m] [-M] [-C] [-R] [-S<string>] [--cached] <tree-ish>";
159
160 int main(int argc, char **argv)
161 {
162 unsigned char tree_sha1[20];
163 void *tree;
164 unsigned long size;
165 int ret;
166
167 read_cache();
168 while (argc > 2) {
169 char *arg = argv[1];
170 argv++;
171 argc--;
172 if (!strcmp(arg, "-r")) {
173 /* We accept the -r flag just to look like git-diff-tree */
174 continue;
175 }
176 if (!strcmp(arg, "-p")) {
177 generate_patch = 1;
178 continue;
179 }
180 if (!strncmp(arg, "-M", 2)) {
181 generate_patch = detect_rename = 1;
182 diff_score_opt = diff_scoreopt_parse(arg);
183 continue;
184 }
185 if (!strncmp(arg, "-C", 2)) {
186 generate_patch = 1;
187 detect_rename = 2;
188 diff_score_opt = diff_scoreopt_parse(arg);
189 continue;
190 }
191 if (!strcmp(arg, "-z")) {
192 line_termination = '\0';
193 continue;
194 }
195 if (!strcmp(arg, "-R")) {
196 reverse_diff = 1;
197 continue;
198 }
199 if (!strcmp(arg, "-S")) {
200 pickaxe = arg + 2;
201 continue;
202 }
203 if (!strcmp(arg, "-m")) {
204 match_nonexisting = 1;
205 continue;
206 }
207 if (!strcmp(arg, "--cached")) {
208 cached_only = 1;
209 continue;
210 }
211 usage(diff_cache_usage);
212 }
213
214 if (argc != 2 || get_sha1(argv[1], tree_sha1))
215 usage(diff_cache_usage);
216
217 diff_setup(reverse_diff, (generate_patch ? -1 : line_termination));
218
219 mark_merge_entries();
220
221 tree = read_object_with_reference(tree_sha1, "tree", &size, NULL);
222 if (!tree)
223 die("bad tree object %s", argv[1]);
224 if (read_tree(tree, size, 1))
225 die("unable to read tree object %s", argv[1]);
226
227 ret = diff_cache(active_cache, active_nr);
228 if (detect_rename)
229 diff_detect_rename(detect_rename, diff_score_opt);
230 if (pickaxe)
231 diff_pickaxe(pickaxe);
232 diff_flush(NULL, 0);
233 return ret;
234 }