c096dc45ee7606c2b2947400f66c350f5801cb06
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"
9static char *def = NULL;
11static int no_revs = 0;
12static int single_rev = 0;
13static int revs_only = 0;
14static int do_rev_argument = 1;
15static int output_revs = 0;
16#define NORMAL 0
18#define REVERSED 1
19static int show_type = NORMAL;
20static int get_extended_sha1(char *name, unsigned char *sha1);
22/*
24 * Some arguments are relevant "revision" arguments,
25 * others are about output format or other details.
26 * This sorts it all out.
27 */
28static int is_rev_argument(const char *arg)
29{
30 static const char *rev_args[] = {
31 "--max-count=",
32 "--max-age=",
33 "--min-age=",
34 "--merge-order",
35 NULL
36 };
37 const char **p = rev_args;
38 for (;;) {
40 const char *str = *p++;
41 int len;
42 if (!str)
43 return 0;
44 len = strlen(str);
45 if (!strncmp(arg, str, len))
46 return 1;
47 }
48}
49static void show_rev(int type, const unsigned char *sha1)
51{
52 if (no_revs)
53 return;
54 output_revs++;
55 printf("%s%s\n", type == show_type ? "" : "^", sha1_to_hex(sha1));
56}
57static void show_rev_arg(char *rev)
59{
60 if (no_revs)
61 return;
62 puts(rev);
63}
64static void show_norev(char *norev)
66{
67 if (revs_only)
68 return;
69 puts(norev);
70}
71static void show_arg(char *arg)
73{
74 if (do_rev_argument && is_rev_argument(arg))
75 show_rev_arg(arg);
76 else
77 show_norev(arg);
78}
79static int get_parent(char *name, unsigned char *result, int idx)
81{
82 unsigned char sha1[20];
83 int ret = get_extended_sha1(name, sha1);
84 struct commit *commit;
85 struct commit_list *p;
86 if (ret)
88 return ret;
89 commit = lookup_commit_reference(sha1);
90 if (!commit)
91 return -1;
92 if (parse_commit(commit))
93 return -1;
94 p = commit->parents;
95 while (p) {
96 if (!--idx) {
97 memcpy(result, p->item->object.sha1, 20);
98 return 0;
99 }
100 p = p->next;
101 }
102 return -1;
103}
104/*
106 * This is like "get_sha1()", except it allows "sha1 expressions",
107 * notably "xyz^" for "parent of xyz"
108 */
109static int get_extended_sha1(char *name, unsigned char *sha1)
110{
111 int parent;
112 int len = strlen(name);
113 parent = 1;
115 if (len > 2 && name[len-1] >= '1' && name[len-1] <= '9') {
116 parent = name[len-1] - '0';
117 len--;
118 }
119 if (len > 1 && name[len-1] == '^') {
120 int ret;
121 name[len-1] = 0;
122 ret = get_parent(name, sha1, parent);
123 name[len-1] = '^';
124 if (!ret)
125 return 0;
126 }
127 return get_sha1(name, sha1);
128}
129static void show_default(void)
131{
132 char *s = def;
133 if (s) {
135 unsigned char sha1[20];
136 def = NULL;
138 if (!get_extended_sha1(s, sha1)) {
139 show_rev(NORMAL, sha1);
140 return;
141 }
142 show_arg(s);
143 }
144}
145static int show_reference(const char *refname, const unsigned char *sha1)
147{
148 show_rev(NORMAL, sha1);
149 return 0;
150}
151int main(int argc, char **argv)
153{
154 int i, as_is = 0;
155 unsigned char sha1[20];
156 for (i = 1; i < argc; i++) {
158 char *arg = argv[i];
159 char *dotdot;
160
161 if (as_is) {
162 show_norev(arg);
163 continue;
164 }
165 if (*arg == '-') {
166 if (!strcmp(arg, "--")) {
167 show_default();
168 if (revs_only)
169 break;
170 as_is = 1;
171 }
172 if (!strcmp(arg, "--default")) {
173 def = argv[i+1];
174 i++;
175 continue;
176 }
177 if (!strcmp(arg, "--revs-only")) {
178 revs_only = 1;
179 continue;
180 }
181 if (!strcmp(arg, "--no-revs")) {
182 no_revs = 1;
183 continue;
184 }
185 if (!strcmp(arg, "--verify")) {
186 revs_only = 1;
187 do_rev_argument = 0;
188 single_rev = 1;
189 continue;
190 }
191 if (!strcmp(arg, "--not")) {
192 show_type ^= REVERSED;
193 continue;
194 }
195 if (!strcmp(arg, "--all")) {
196 for_each_ref(show_reference);
197 continue;
198 }
199 show_arg(arg);
200 continue;
201 }
202 dotdot = strstr(arg, "..");
203 if (dotdot) {
204 unsigned char end[20];
205 char *n = dotdot+2;
206 *dotdot = 0;
207 if (!get_extended_sha1(arg, sha1)) {
208 if (!*n)
209 n = "HEAD";
210 if (!get_extended_sha1(n, end)) {
211 if (no_revs)
212 continue;
213 def = NULL;
214 show_rev(NORMAL, end);
215 show_rev(REVERSED, sha1);
216 continue;
217 }
218 }
219 *dotdot = '.';
220 }
221 if (!get_extended_sha1(arg, sha1)) {
222 if (no_revs)
223 continue;
224 def = NULL;
225 show_rev(NORMAL, sha1);
226 continue;
227 }
228 if (*arg == '^' && !get_extended_sha1(arg+1, sha1)) {
229 if (no_revs)
230 continue;
231 def = NULL;
232 show_rev(REVERSED, sha1);
233 continue;
234 }
235 show_default();
236 show_norev(arg);
237 }
238 show_default();
239 if (single_rev && output_revs != 1) {
240 fprintf(stderr, "Needed a single revision\n");
241 exit(1);
242 }
243 return 0;
244}