[PATCH] Fix git rpush.
[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 line_termination = '\n';
7
8 /* A file entry went away or appeared */
9 static void show_file(const char *prefix, struct cache_entry *ce, unsigned char *sha1, unsigned int mode)
10 {
11         if (generate_patch)
12                 diff_addremove(prefix[0], ntohl(mode), sha1, ce->name, NULL);
13         else
14                 printf("%s%06o\tblob\t%s\t%s%c", prefix, ntohl(mode),
15                        sha1_to_hex(sha1), ce->name, line_termination);
16 }
17
18 static 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 (stat(ce->name, &st) < 0)
28                         return -1;
29                 changed = cache_match_stat(ce, &st);
30                 if (changed) {
31                         mode = create_ce_mode(st.st_mode);
32                         sha1 = no_sha1;
33                 }
34         }
35
36         *sha1p = sha1;
37         *modep = mode;
38         return 0;
39 }
40
41 static void show_new_file(struct cache_entry *new)
42 {
43         unsigned char *sha1;
44         unsigned int mode;
45
46         /* New file in the index: it might actually be different in the working copy */
47         if (get_stat_data(new, &sha1, &mode) < 0)
48                 return;
49
50         show_file("+", new, sha1, mode);
51 }
52
53 static int show_modified(struct cache_entry *old, struct cache_entry *new)
54 {
55         unsigned int mode, oldmode;
56         unsigned char *sha1;
57         unsigned char old_sha1_hex[60];
58
59         if (get_stat_data(new, &sha1, &mode) < 0) {
60                 show_file("-", old, old->sha1, old->ce_mode);
61                 return -1;
62         }
63
64         oldmode = old->ce_mode;
65         if (mode == oldmode && !memcmp(sha1, old->sha1, 20))
66                 return 0;
67
68         mode = ntohl(mode);
69         oldmode = ntohl(oldmode);
70
71         if (generate_patch)
72                 diff_change(oldmode, mode,
73                             old->sha1, sha1, old->name, NULL);
74         else {
75                 strcpy(old_sha1_hex, sha1_to_hex(old->sha1));
76                 printf("*%06o->%06o\tblob\t%s->%s\t%s%c", oldmode, mode,
77                        old_sha1_hex, sha1_to_hex(sha1),
78                        old->name, line_termination);
79         }
80         return 0;
81 }
82
83 static int diff_cache(struct cache_entry **ac, int entries)
84 {
85         while (entries) {
86                 struct cache_entry *ce = *ac;
87                 int same = (entries > 1) && same_name(ce, ac[1]);
88
89                 switch (ce_stage(ce)) {
90                 case 0:
91                         /* No stage 1 entry? That means it's a new file */
92                         if (!same) {
93                                 show_new_file(ce);
94                                 break;
95                         }
96                         /* Show difference between old and new */
97                         show_modified(ac[1], ce);
98                         break;
99                 case 1:
100                         /* No stage 3 (merge) entry? That means it's been deleted */
101                         if (!same) {
102                                 show_file("-", ce, ce->sha1, ce->ce_mode);
103                                 break;
104                         }
105                         /* Otherwise we fall through to the "unmerged" case */
106                 case 3:
107                         if (generate_patch)
108                                 diff_unmerge(ce->name);
109                         else
110                                 printf("U %s%c", ce->name, line_termination);
111                         break;
112
113                 default:
114                         die("impossible cache entry stage");
115                 }
116
117                 /*
118                  * Ignore all the different stages for this file,
119                  * we've handled the relevant cases now.
120                  */
121                 do {
122                         ac++;
123                         entries--;
124                 } while (entries && same_name(ce, ac[0]));
125         }
126         return 0;
127 }
128
129 /*
130  * This turns all merge entries into "stage 3". That guarantees that
131  * when we read in the new tree (into "stage 1"), we won't lose sight
132  * of the fact that we had unmerged entries.
133  */
134 static void mark_merge_entries(void)
135 {
136         int i;
137         for (i = 0; i < active_nr; i++) {
138                 struct cache_entry *ce = active_cache[i];
139                 if (!ce_stage(ce))
140                         continue;
141                 ce->ce_flags |= htons(CE_STAGEMASK);
142         }
143 }
144
145 static char *diff_cache_usage =
146 "diff-cache [-r] [-z] [-p] [--cached] <tree sha1>";
147
148 int main(int argc, char **argv)
149 {
150         unsigned char tree_sha1[20];
151         void *tree;
152         unsigned long size;
153
154         read_cache();
155         while (argc > 2) {
156                 char *arg = argv[1];
157                 argv++;
158                 argc--;
159                 if (!strcmp(arg, "-r")) {
160                         /* We accept the -r flag just to look like diff-tree */
161                         continue;
162                 }
163                 if (!strcmp(arg, "-p")) {
164                         generate_patch = 1;
165                         continue;
166                 }
167                 if (!strcmp(arg, "-z")) {
168                         line_termination = '\0';
169                         continue;
170                 }
171                 if (!strcmp(arg, "--cached")) {
172                         cached_only = 1;
173                         continue;
174                 }
175                 usage(diff_cache_usage);
176         }
177
178         if (argc != 2 || get_sha1(argv[1], tree_sha1))
179                 usage(diff_cache_usage);
180
181         mark_merge_entries();
182
183         tree = read_object_with_reference(tree_sha1, "tree", &size, 0);
184         if (!tree)
185                 die("bad tree object %s", argv[1]);
186         if (read_tree(tree, size, 1))
187                 die("unable to read tree object %s", argv[1]);
188
189         return diff_cache(active_cache, active_nr);
190 }