1/*
2 * rev-parse.c
3 *
4 * Copyright (C) Linus Torvalds, 2005
5 */
6#include "cache.h"
7#include "commit.h"
8static char *def = NULL;
10static int no_revs = 0;
11static int single_rev = 0;
12static int revs_only = 0;
13static int do_rev_argument = 1;
14static int output_revs = 0;
15static int get_extended_sha1(char *name, unsigned char *sha1);
17/*
19 * Some arguments are relevant "revision" arguments,
20 * others are about output format or other details.
21 * This sorts it all out.
22 */
23static int is_rev_argument(const char *arg)
24{
25 static const char *rev_args[] = {
26 "--max-count=",
27 "--max-age=",
28 "--min-age=",
29 "--merge-order",
30 NULL
31 };
32 const char **p = rev_args;
33 for (;;) {
35 const char *str = *p++;
36 int len;
37 if (!str)
38 return 0;
39 len = strlen(str);
40 if (!strncmp(arg, str, len))
41 return 1;
42 }
43}
44static void show_rev(unsigned char *sha1)
46{
47 if (no_revs)
48 return;
49 output_revs++;
50 puts(sha1_to_hex(sha1));
51}
52static void show_antirev(unsigned char *sha1)
54{
55 if (no_revs)
56 return;
57 output_revs++;
58 printf("^%s\n", sha1_to_hex(sha1));
59}
60static void show_rev_arg(char *rev)
62{
63 if (no_revs)
64 return;
65 puts(rev);
66}
67static void show_norev(char *norev)
69{
70 if (revs_only)
71 return;
72 puts(norev);
73}
74static void show_arg(char *arg)
76{
77 if (do_rev_argument && is_rev_argument(arg))
78 show_rev_arg(arg);
79 else
80 show_norev(arg);
81}
82static int get_parent(char *name, unsigned char *result, int idx)
84{
85 unsigned char sha1[20];
86 int ret = get_extended_sha1(name, sha1);
87 struct commit *commit;
88 struct commit_list *p;
89 if (ret)
91 return ret;
92 commit = lookup_commit_reference(sha1);
93 if (!commit)
94 return -1;
95 if (parse_commit(commit))
96 return -1;
97 p = commit->parents;
98 while (p) {
99 if (!--idx) {
100 memcpy(result, p->item->object.sha1, 20);
101 return 0;
102 }
103 p = p->next;
104 }
105 return -1;
106}
107/*
109 * This is like "get_sha1()", except it allows "sha1 expressions",
110 * notably "xyz^" for "parent of xyz"
111 */
112static int get_extended_sha1(char *name, unsigned char *sha1)
113{
114 int parent;
115 int len = strlen(name);
116 parent = 1;
118 if (len > 2 && name[len-1] >= '1' && name[len-1] <= '9') {
119 parent = name[len-1] - '0';
120 len--;
121 }
122 if (len > 1 && name[len-1] == '^') {
123 int ret;
124 name[len-1] = 0;
125 ret = get_parent(name, sha1, parent);
126 name[len-1] = '^';
127 if (!ret)
128 return 0;
129 }
130 return get_sha1(name, sha1);
131}
132static void show_default(void)
134{
135 char *s = def;
136 if (s) {
138 unsigned char sha1[20];
139 def = NULL;
141 if (!get_extended_sha1(s, sha1)) {
142 show_rev(sha1);
143 return;
144 }
145 show_arg(s);
146 }
147}
148int main(int argc, char **argv)
150{
151 int i, as_is = 0;
152 unsigned char sha1[20];
153 for (i = 1; i < argc; i++) {
155 char *arg = argv[i];
156 char *dotdot;
157
158 if (as_is) {
159 show_norev(arg);
160 continue;
161 }
162 if (*arg == '-') {
163 if (!strcmp(arg, "--")) {
164 show_default();
165 if (revs_only)
166 break;
167 as_is = 1;
168 }
169 if (!strcmp(arg, "--default")) {
170 def = argv[i+1];
171 i++;
172 continue;
173 }
174 if (!strcmp(arg, "--revs-only")) {
175 revs_only = 1;
176 continue;
177 }
178 if (!strcmp(arg, "--no-revs")) {
179 no_revs = 1;
180 continue;
181 }
182 if (!strcmp(arg, "--verify")) {
183 revs_only = 1;
184 do_rev_argument = 0;
185 single_rev = 1;
186 continue;
187 }
188 show_arg(arg);
189 continue;
190 }
191 dotdot = strstr(arg, "..");
192 if (dotdot) {
193 unsigned char end[20];
194 char *n = dotdot+2;
195 *dotdot = 0;
196 if (!get_extended_sha1(arg, sha1)) {
197 if (!*n)
198 n = "HEAD";
199 if (!get_extended_sha1(n, end)) {
200 if (no_revs)
201 continue;
202 def = NULL;
203 show_rev(end);
204 show_antirev(sha1);
205 continue;
206 }
207 }
208 *dotdot = '.';
209 }
210 if (!get_extended_sha1(arg, sha1)) {
211 if (no_revs)
212 continue;
213 def = NULL;
214 show_rev(sha1);
215 continue;
216 }
217 if (*arg == '^' && !get_extended_sha1(arg+1, sha1)) {
218 if (no_revs)
219 continue;
220 def = NULL;
221 show_antirev(sha1);
222 continue;
223 }
224 show_default();
225 show_norev(arg);
226 }
227 show_default();
228 if (single_rev && output_revs != 1) {
229 fprintf(stderr, "Needed a single revision\n");
230 exit(1);
231 }
232 return 0;
233}