Improved pack format documentation.
[git] / builtin-diff-stages.c
1 /*
2  * Copyright (c) 2005 Junio C Hamano
3  */
4
5 #include "cache.h"
6 #include "diff.h"
7 #include "builtin.h"
8
9 static struct diff_options diff_options;
10
11 static const char diff_stages_usage[] =
12 "git-diff-stages [<common diff options>] <stage1> <stage2> [<path>...]"
13 COMMON_DIFF_OPTIONS_HELP;
14
15 static void diff_stages(int stage1, int stage2, const char **pathspec)
16 {
17         int i = 0;
18         while (i < active_nr) {
19                 struct cache_entry *ce, *stages[4] = { NULL, };
20                 struct cache_entry *one, *two;
21                 const char *name;
22                 int len, skip;
23
24                 ce = active_cache[i];
25                 skip = !ce_path_match(ce, pathspec);
26                 len = ce_namelen(ce);
27                 name = ce->name;
28                 for (;;) {
29                         int stage = ce_stage(ce);
30                         stages[stage] = ce;
31                         if (active_nr <= ++i)
32                                 break;
33                         ce = active_cache[i];
34                         if (ce_namelen(ce) != len ||
35                             memcmp(name, ce->name, len))
36                                 break;
37                 }
38                 one = stages[stage1];
39                 two = stages[stage2];
40
41                 if (skip || (!one && !two))
42                         continue;
43                 if (!one)
44                         diff_addremove(&diff_options, '+', ntohl(two->ce_mode),
45                                        two->sha1, name, NULL);
46                 else if (!two)
47                         diff_addremove(&diff_options, '-', ntohl(one->ce_mode),
48                                        one->sha1, name, NULL);
49                 else if (memcmp(one->sha1, two->sha1, 20) ||
50                          (one->ce_mode != two->ce_mode) ||
51                          diff_options.find_copies_harder)
52                         diff_change(&diff_options,
53                                     ntohl(one->ce_mode), ntohl(two->ce_mode),
54                                     one->sha1, two->sha1, name, NULL);
55         }
56 }
57
58 int cmd_diff_stages(int ac, const char **av, char **envp)
59 {
60         int stage1, stage2;
61         const char *prefix = setup_git_directory();
62         const char **pathspec = NULL;
63
64         git_config(git_diff_config);
65         read_cache();
66         diff_setup(&diff_options);
67         while (1 < ac && av[1][0] == '-') {
68                 const char *arg = av[1];
69                 if (!strcmp(arg, "-r"))
70                         ; /* as usual */
71                 else {
72                         int diff_opt_cnt;
73                         diff_opt_cnt = diff_opt_parse(&diff_options,
74                                                       av+1, ac-1);
75                         if (diff_opt_cnt < 0)
76                                 usage(diff_stages_usage);
77                         else if (diff_opt_cnt) {
78                                 av += diff_opt_cnt;
79                                 ac -= diff_opt_cnt;
80                                 continue;
81                         }
82                         else
83                                 usage(diff_stages_usage);
84                 }
85                 ac--; av++;
86         }
87
88         if (ac < 3 ||
89             sscanf(av[1], "%d", &stage1) != 1 ||
90             ! (0 <= stage1 && stage1 <= 3) ||
91             sscanf(av[2], "%d", &stage2) != 1 ||
92             ! (0 <= stage2 && stage2 <= 3))
93                 usage(diff_stages_usage);
94
95         av += 3; /* The rest from av[0] are for paths restriction. */
96         pathspec = get_pathspec(prefix, av);
97
98         if (diff_setup_done(&diff_options) < 0)
99                 usage(diff_stages_usage);
100
101         diff_stages(stage1, stage2, pathspec);
102         diffcore_std(&diff_options);
103         diff_flush(&diff_options);
104         return 0;
105 }