Handle symlinks graciously
[git] / diff-stages.c
1 /*
2  * Copyright (c) 2005 Junio C Hamano
3  */
4
5 #include "cache.h"
6 #include "diff.h"
7
8 static struct diff_options diff_options;
9
10 static const char diff_stages_usage[] =
11 "git-diff-stages [<common diff options>] <stage1> <stage2> [<path>...]"
12 COMMON_DIFF_OPTIONS_HELP;
13
14 static void diff_stages(int stage1, int stage2)
15 {
16         int i = 0;
17         while (i < active_nr) {
18                 struct cache_entry *ce, *stages[4] = { NULL, };
19                 struct cache_entry *one, *two;
20                 const char *name;
21                 int len;
22                 ce = active_cache[i];
23                 len = ce_namelen(ce);
24                 name = ce->name;
25                 for (;;) {
26                         int stage = ce_stage(ce);
27                         stages[stage] = ce;
28                         if (active_nr <= ++i)
29                                 break;
30                         ce = active_cache[i];
31                         if (ce_namelen(ce) != len ||
32                             memcmp(name, ce->name, len))
33                                 break;
34                 }
35                 one = stages[stage1];
36                 two = stages[stage2];
37                 if (!one && !two)
38                         continue;
39                 if (!one)
40                         diff_addremove(&diff_options, '+', ntohl(two->ce_mode),
41                                        two->sha1, name, NULL);
42                 else if (!two)
43                         diff_addremove(&diff_options, '-', ntohl(one->ce_mode),
44                                        one->sha1, name, NULL);
45                 else if (memcmp(one->sha1, two->sha1, 20) ||
46                          (one->ce_mode != two->ce_mode) ||
47                          diff_options.find_copies_harder)
48                         diff_change(&diff_options,
49                                     ntohl(one->ce_mode), ntohl(two->ce_mode),
50                                     one->sha1, two->sha1, name, NULL);
51         }
52 }
53
54 int main(int ac, const char **av)
55 {
56         int stage1, stage2;
57
58         setup_git_directory();
59
60         git_config(git_diff_config);
61         read_cache();
62         diff_setup(&diff_options);
63         while (1 < ac && av[1][0] == '-') {
64                 const char *arg = av[1];
65                 if (!strcmp(arg, "-r"))
66                         ; /* as usual */
67                 else {
68                         int diff_opt_cnt;
69                         diff_opt_cnt = diff_opt_parse(&diff_options,
70                                                       av+1, ac-1);
71                         if (diff_opt_cnt < 0)
72                                 usage(diff_stages_usage);
73                         else if (diff_opt_cnt) {
74                                 av += diff_opt_cnt;
75                                 ac -= diff_opt_cnt;
76                                 continue;
77                         }
78                         else
79                                 usage(diff_stages_usage);
80                 }
81                 ac--; av++;
82         }
83
84         if (ac < 3 ||
85             sscanf(av[1], "%d", &stage1) != 1 ||
86             ! (0 <= stage1 && stage1 <= 3) ||
87             sscanf(av[2], "%d", &stage2) != 1 ||
88             ! (0 <= stage2 && stage2 <= 3))
89                 usage(diff_stages_usage);
90
91         av += 3; /* The rest from av[0] are for paths restriction. */
92         diff_options.paths = av;
93
94         if (diff_setup_done(&diff_options) < 0)
95                 usage(diff_stages_usage);
96
97         diff_stages(stage1, stage2);
98         diffcore_std(&diff_options);
99         diff_flush(&diff_options);
100         return 0;
101 }