[PATCH] Make "git resolve" less scary
[git.git] / rev-parse.c
1 /*
2  * rev-parse.c
3  *
4  * Copyright (C) Linus Torvalds, 2005
5  */
6 #include "cache.h"
7 #include "commit.h"
8 #include "refs.h"
9
10 #define DO_REVS         1
11 #define DO_NOREV        2
12 #define DO_FLAGS        4
13 #define DO_NONFLAGS     8
14 static int filter = ~0;
15
16 static char *def = NULL;
17
18 #define NORMAL 0
19 #define REVERSED 1
20 static int show_type = NORMAL;
21 static int symbolic = 0;
22 static int output_sq = 0;
23
24 static int revs_count = 0;
25
26 /*
27  * Some arguments are relevant "revision" arguments,
28  * others are about output format or other details.
29  * This sorts it all out.
30  */
31 static int is_rev_argument(const char *arg)
32 {
33         static const char *rev_args[] = {
34                 "--bisect",
35                 "--header",
36                 "--max-age=",
37                 "--max-count=",
38                 "--merge-order",
39                 "--min-age=",
40                 "--no-merges",
41                 "--objects",
42                 "--parents",
43                 "--pretty",
44                 "--show-breaks",
45                 "--topo-order",
46                 "--unpacked",
47                 NULL
48         };
49         const char **p = rev_args;
50
51         for (;;) {
52                 const char *str = *p++;
53                 int len;
54                 if (!str)
55                         return 0;
56                 len = strlen(str);
57                 if (!strcmp(arg, str) ||
58                     (str[len-1] == '=' && !strncmp(arg, str, len)))
59                         return 1;
60         }
61 }
62
63 /* Output argument as a string, either SQ or normal */
64 static void show(const char *arg)
65 {
66         if (output_sq) {
67                 int sq = '\'', ch;
68
69                 putchar(sq);
70                 while ((ch = *arg++)) {
71                         if (ch == sq)
72                                 fputs("'\\'", stdout);
73                         putchar(ch);
74                 }
75                 putchar(sq);
76                 putchar(' ');
77         }
78         else
79                 puts(arg);
80 }
81
82 /* Output a revision, only if filter allows it */
83 static void show_rev(int type, const unsigned char *sha1, const char *name)
84 {
85         if (!(filter & DO_REVS))
86                 return;
87         def = NULL;
88         revs_count++;
89
90         if (type != show_type)
91                 putchar('^');
92         if (symbolic && name)
93                 show(name);
94         else
95                 show(sha1_to_hex(sha1));
96 }
97
98 /* Output a flag, only if filter allows it. */
99 static void show_flag(char *arg)
100 {
101         if (!(filter & DO_FLAGS))
102                 return;
103         if (filter & (is_rev_argument(arg) ? DO_REVS : DO_NOREV))
104                 show(arg);
105 }
106
107 static void show_default(void)
108 {
109         char *s = def;
110
111         if (s) {
112                 unsigned char sha1[20];
113
114                 def = NULL;
115                 if (!get_sha1(s, sha1)) {
116                         show_rev(NORMAL, sha1, s);
117                         return;
118                 }
119         }
120 }
121
122 static int show_reference(const char *refname, const unsigned char *sha1)
123 {
124         show_rev(NORMAL, sha1, refname);
125         return 0;
126 }
127
128 int main(int argc, char **argv)
129 {
130         int i, as_is = 0, verify = 0;
131         unsigned char sha1[20];
132         const char *prefix = setup_git_directory();
133         
134         for (i = 1; i < argc; i++) {
135                 char *arg = argv[i];
136                 char *dotdot;
137         
138                 if (as_is) {
139                         show(arg);
140                         continue;
141                 }
142                 if (*arg == '-') {
143                         if (!strcmp(arg, "--")) {
144                                 as_is = 1;
145                                 continue;
146                         }
147                         if (!strcmp(arg, "--default")) {
148                                 def = argv[i+1];
149                                 i++;
150                                 continue;
151                         }
152                         if (!strcmp(arg, "--revs-only")) {
153                                 filter &= ~DO_NOREV;
154                                 continue;
155                         }
156                         if (!strcmp(arg, "--no-revs")) {
157                                 filter &= ~DO_REVS;
158                                 continue;
159                         }
160                         if (!strcmp(arg, "--flags")) {
161                                 filter &= ~DO_NONFLAGS;
162                                 continue;
163                         }
164                         if (!strcmp(arg, "--no-flags")) {
165                                 filter &= ~DO_FLAGS;
166                                 continue;
167                         }
168                         if (!strcmp(arg, "--verify")) {
169                                 filter &= ~(DO_FLAGS|DO_NOREV);
170                                 verify = 1;
171                                 continue;
172                         }
173                         if (!strcmp(arg, "--sq")) {
174                                 output_sq = 1;
175                                 continue;
176                         }
177                         if (!strcmp(arg, "--not")) {
178                                 show_type ^= REVERSED;
179                                 continue;
180                         }
181                         if (!strcmp(arg, "--symbolic")) {
182                                 symbolic = 1;
183                                 continue;
184                         }
185                         if (!strcmp(arg, "--all")) {
186                                 for_each_ref(show_reference);
187                                 continue;
188                         }
189                         if (!strcmp(arg, "--show-prefix")) {
190                                 if (prefix)
191                                         puts(prefix);
192                                 continue;
193                         }
194                         if (verify)
195                                 die("Needed a single revision");
196                         show_flag(arg);
197                         continue;
198                 }
199
200                 /* Not a flag argument */
201                 dotdot = strstr(arg, "..");
202                 if (dotdot) {
203                         unsigned char end[20];
204                         char *n = dotdot+2;
205                         *dotdot = 0;
206                         if (!get_sha1(arg, sha1)) {
207                                 if (!*n)
208                                         n = "HEAD";
209                                 if (!get_sha1(n, end)) {
210                                         show_rev(NORMAL, end, n);
211                                         show_rev(REVERSED, sha1, arg);
212                                         continue;
213                                 }
214                         }
215                         *dotdot = '.';
216                 }
217                 if (!get_sha1(arg, sha1)) {
218                         show_rev(NORMAL, sha1, arg);
219                         continue;
220                 }
221                 if (*arg == '^' && !get_sha1(arg+1, sha1)) {
222                         show_rev(REVERSED, sha1, arg+1);
223                         continue;
224                 }
225                 if (verify)
226                         die("Needed a single revision");
227                 if ((filter & (DO_NONFLAGS|DO_NOREV)) ==
228                     (DO_NONFLAGS|DO_NOREV))
229                         show(arg);
230         }
231         show_default();
232         if (verify && revs_count != 1)
233                 die("Needed a single revision");
234         return 0;
235 }