Merge branch 'cb/byte-order'
[git/git.git] / builtin / update-ref.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "builtin.h"
4 #include "parse-options.h"
5 #include "quote.h"
6 #include "argv-array.h"
7
8 static const char * const git_update_ref_usage[] = {
9 N_("git update-ref [options] -d <refname> [<oldval>]"),
10 N_("git update-ref [options] <refname> <newval> [<oldval>]"),
11 N_("git update-ref [options] --stdin [-z]"),
12 NULL
13 };
14
15 static struct ref_transaction *transaction;
16
17 static char line_termination = '\n';
18 static int update_flags;
19
20 /*
21 * Parse one whitespace- or NUL-terminated, possibly C-quoted argument
22 * and append the result to arg. Return a pointer to the terminator.
23 * Die if there is an error in how the argument is C-quoted. This
24 * function is only used if not -z.
25 */
26 static const char *parse_arg(const char *next, struct strbuf *arg)
27 {
28 if (*next == '"') {
29 const char *orig = next;
30
31 if (unquote_c_style(arg, next, &next))
32 die("badly quoted argument: %s", orig);
33 if (*next && !isspace(*next))
34 die("unexpected character after quoted argument: %s", orig);
35 } else {
36 while (*next && !isspace(*next))
37 strbuf_addch(arg, *next++);
38 }
39
40 return next;
41 }
42
43 /*
44 * Parse the reference name immediately after "command SP". If not
45 * -z, then handle C-quoting. Return a pointer to a newly allocated
46 * string containing the name of the reference, or NULL if there was
47 * an error. Update *next to point at the character that terminates
48 * the argument. Die if C-quoting is malformed or the reference name
49 * is invalid.
50 */
51 static char *parse_refname(struct strbuf *input, const char **next)
52 {
53 struct strbuf ref = STRBUF_INIT;
54
55 if (line_termination) {
56 /* Without -z, use the next argument */
57 *next = parse_arg(*next, &ref);
58 } else {
59 /* With -z, use everything up to the next NUL */
60 strbuf_addstr(&ref, *next);
61 *next += ref.len;
62 }
63
64 if (!ref.len) {
65 strbuf_release(&ref);
66 return NULL;
67 }
68
69 if (check_refname_format(ref.buf, REFNAME_ALLOW_ONELEVEL))
70 die("invalid ref format: %s", ref.buf);
71
72 return strbuf_detach(&ref, NULL);
73 }
74
75 /*
76 * The value being parsed is <oldvalue> (as opposed to <newvalue>; the
77 * difference affects which error messages are generated):
78 */
79 #define PARSE_SHA1_OLD 0x01
80
81 /*
82 * For backwards compatibility, accept an empty string for update's
83 * <newvalue> in binary mode to be equivalent to specifying zeros.
84 */
85 #define PARSE_SHA1_ALLOW_EMPTY 0x02
86
87 /*
88 * Parse an argument separator followed by the next argument, if any.
89 * If there is an argument, convert it to a SHA-1, write it to sha1,
90 * set *next to point at the character terminating the argument, and
91 * return 0. If there is no argument at all (not even the empty
92 * string), return 1 and leave *next unchanged. If the value is
93 * provided but cannot be converted to a SHA-1, die. flags can
94 * include PARSE_SHA1_OLD and/or PARSE_SHA1_ALLOW_EMPTY.
95 */
96 static int parse_next_sha1(struct strbuf *input, const char **next,
97 unsigned char *sha1,
98 const char *command, const char *refname,
99 int flags)
100 {
101 struct strbuf arg = STRBUF_INIT;
102 int ret = 0;
103
104 if (*next == input->buf + input->len)
105 goto eof;
106
107 if (line_termination) {
108 /* Without -z, consume SP and use next argument */
109 if (!**next || **next == line_termination)
110 return 1;
111 if (**next != ' ')
112 die("%s %s: expected SP but got: %s",
113 command, refname, *next);
114 (*next)++;
115 *next = parse_arg(*next, &arg);
116 if (arg.len) {
117 if (get_sha1(arg.buf, sha1))
118 goto invalid;
119 } else {
120 /* Without -z, an empty value means all zeros: */
121 hashclr(sha1);
122 }
123 } else {
124 /* With -z, read the next NUL-terminated line */
125 if (**next)
126 die("%s %s: expected NUL but got: %s",
127 command, refname, *next);
128 (*next)++;
129 if (*next == input->buf + input->len)
130 goto eof;
131 strbuf_addstr(&arg, *next);
132 *next += arg.len;
133
134 if (arg.len) {
135 if (get_sha1(arg.buf, sha1))
136 goto invalid;
137 } else if (flags & PARSE_SHA1_ALLOW_EMPTY) {
138 /* With -z, treat an empty value as all zeros: */
139 warning("%s %s: missing <newvalue>, treating as zero",
140 command, refname);
141 hashclr(sha1);
142 } else {
143 /*
144 * With -z, an empty non-required value means
145 * unspecified:
146 */
147 ret = 1;
148 }
149 }
150
151 strbuf_release(&arg);
152
153 return ret;
154
155 invalid:
156 die(flags & PARSE_SHA1_OLD ?
157 "%s %s: invalid <oldvalue>: %s" :
158 "%s %s: invalid <newvalue>: %s",
159 command, refname, arg.buf);
160
161 eof:
162 die(flags & PARSE_SHA1_OLD ?
163 "%s %s: unexpected end of input when reading <oldvalue>" :
164 "%s %s: unexpected end of input when reading <newvalue>",
165 command, refname);
166 }
167
168
169 /*
170 * The following five parse_cmd_*() functions parse the corresponding
171 * command. In each case, next points at the character following the
172 * command name and the following space. They each return a pointer
173 * to the character terminating the command, and die with an
174 * explanatory message if there are any parsing problems. All of
175 * these functions handle either text or binary format input,
176 * depending on how line_termination is set.
177 */
178
179 static const char *parse_cmd_update(struct strbuf *input, const char *next)
180 {
181 char *refname;
182 unsigned char new_sha1[20];
183 unsigned char old_sha1[20];
184 int have_old;
185
186 refname = parse_refname(input, &next);
187 if (!refname)
188 die("update: missing <ref>");
189
190 if (parse_next_sha1(input, &next, new_sha1, "update", refname,
191 PARSE_SHA1_ALLOW_EMPTY))
192 die("update %s: missing <newvalue>", refname);
193
194 have_old = !parse_next_sha1(input, &next, old_sha1, "update", refname,
195 PARSE_SHA1_OLD);
196
197 if (*next != line_termination)
198 die("update %s: extra input: %s", refname, next);
199
200 ref_transaction_update(transaction, refname, new_sha1, old_sha1,
201 update_flags, have_old);
202
203 update_flags = 0;
204 free(refname);
205
206 return next;
207 }
208
209 static const char *parse_cmd_create(struct strbuf *input, const char *next)
210 {
211 char *refname;
212 unsigned char new_sha1[20];
213
214 refname = parse_refname(input, &next);
215 if (!refname)
216 die("create: missing <ref>");
217
218 if (parse_next_sha1(input, &next, new_sha1, "create", refname, 0))
219 die("create %s: missing <newvalue>", refname);
220
221 if (is_null_sha1(new_sha1))
222 die("create %s: zero <newvalue>", refname);
223
224 if (*next != line_termination)
225 die("create %s: extra input: %s", refname, next);
226
227 ref_transaction_create(transaction, refname, new_sha1, update_flags);
228
229 update_flags = 0;
230 free(refname);
231
232 return next;
233 }
234
235 static const char *parse_cmd_delete(struct strbuf *input, const char *next)
236 {
237 char *refname;
238 unsigned char old_sha1[20];
239 int have_old;
240
241 refname = parse_refname(input, &next);
242 if (!refname)
243 die("delete: missing <ref>");
244
245 if (parse_next_sha1(input, &next, old_sha1, "delete", refname,
246 PARSE_SHA1_OLD)) {
247 have_old = 0;
248 } else {
249 if (is_null_sha1(old_sha1))
250 die("delete %s: zero <oldvalue>", refname);
251 have_old = 1;
252 }
253
254 if (*next != line_termination)
255 die("delete %s: extra input: %s", refname, next);
256
257 ref_transaction_delete(transaction, refname, old_sha1,
258 update_flags, have_old);
259
260 update_flags = 0;
261 free(refname);
262
263 return next;
264 }
265
266 static const char *parse_cmd_verify(struct strbuf *input, const char *next)
267 {
268 char *refname;
269 unsigned char new_sha1[20];
270 unsigned char old_sha1[20];
271 int have_old;
272
273 refname = parse_refname(input, &next);
274 if (!refname)
275 die("verify: missing <ref>");
276
277 if (parse_next_sha1(input, &next, old_sha1, "verify", refname,
278 PARSE_SHA1_OLD)) {
279 hashclr(new_sha1);
280 have_old = 0;
281 } else {
282 hashcpy(new_sha1, old_sha1);
283 have_old = 1;
284 }
285
286 if (*next != line_termination)
287 die("verify %s: extra input: %s", refname, next);
288
289 ref_transaction_update(transaction, refname, new_sha1, old_sha1,
290 update_flags, have_old);
291
292 update_flags = 0;
293 free(refname);
294
295 return next;
296 }
297
298 static const char *parse_cmd_option(struct strbuf *input, const char *next)
299 {
300 if (!strncmp(next, "no-deref", 8) && next[8] == line_termination)
301 update_flags |= REF_NODEREF;
302 else
303 die("option unknown: %s", next);
304 return next + 8;
305 }
306
307 static void update_refs_stdin(void)
308 {
309 struct strbuf input = STRBUF_INIT;
310 const char *next;
311
312 if (strbuf_read(&input, 0, 1000) < 0)
313 die_errno("could not read from stdin");
314 next = input.buf;
315 /* Read each line dispatch its command */
316 while (next < input.buf + input.len) {
317 if (*next == line_termination)
318 die("empty command in input");
319 else if (isspace(*next))
320 die("whitespace before command: %s", next);
321 else if (starts_with(next, "update "))
322 next = parse_cmd_update(&input, next + 7);
323 else if (starts_with(next, "create "))
324 next = parse_cmd_create(&input, next + 7);
325 else if (starts_with(next, "delete "))
326 next = parse_cmd_delete(&input, next + 7);
327 else if (starts_with(next, "verify "))
328 next = parse_cmd_verify(&input, next + 7);
329 else if (starts_with(next, "option "))
330 next = parse_cmd_option(&input, next + 7);
331 else
332 die("unknown command: %s", next);
333
334 next++;
335 }
336
337 strbuf_release(&input);
338 }
339
340 int cmd_update_ref(int argc, const char **argv, const char *prefix)
341 {
342 const char *refname, *oldval, *msg = NULL;
343 unsigned char sha1[20], oldsha1[20];
344 int delete = 0, no_deref = 0, read_stdin = 0, end_null = 0, flags = 0;
345 struct option options[] = {
346 OPT_STRING( 'm', NULL, &msg, N_("reason"), N_("reason of the update")),
347 OPT_BOOL('d', NULL, &delete, N_("delete the reference")),
348 OPT_BOOL( 0 , "no-deref", &no_deref,
349 N_("update <refname> not the one it points to")),
350 OPT_BOOL('z', NULL, &end_null, N_("stdin has NUL-terminated arguments")),
351 OPT_BOOL( 0 , "stdin", &read_stdin, N_("read updates from stdin")),
352 OPT_END(),
353 };
354
355 git_config(git_default_config, NULL);
356 argc = parse_options(argc, argv, prefix, options, git_update_ref_usage,
357 0);
358 if (msg && !*msg)
359 die("Refusing to perform update with empty message.");
360
361 if (read_stdin) {
362 int ret;
363 transaction = ref_transaction_begin();
364
365 if (delete || no_deref || argc > 0)
366 usage_with_options(git_update_ref_usage, options);
367 if (end_null)
368 line_termination = '\0';
369 update_refs_stdin();
370 ret = ref_transaction_commit(transaction, msg,
371 UPDATE_REFS_DIE_ON_ERR);
372 return ret;
373 }
374
375 if (end_null)
376 usage_with_options(git_update_ref_usage, options);
377
378 if (delete) {
379 if (argc < 1 || argc > 2)
380 usage_with_options(git_update_ref_usage, options);
381 refname = argv[0];
382 oldval = argv[1];
383 } else {
384 const char *value;
385 if (argc < 2 || argc > 3)
386 usage_with_options(git_update_ref_usage, options);
387 refname = argv[0];
388 value = argv[1];
389 oldval = argv[2];
390 if (get_sha1(value, sha1))
391 die("%s: not a valid SHA1", value);
392 }
393
394 hashclr(oldsha1); /* all-zero hash in case oldval is the empty string */
395 if (oldval && *oldval && get_sha1(oldval, oldsha1))
396 die("%s: not a valid old SHA1", oldval);
397
398 if (no_deref)
399 flags = REF_NODEREF;
400 if (delete)
401 return delete_ref(refname, oldval ? oldsha1 : NULL, flags);
402 else
403 return update_ref(msg, refname, sha1, oldval ? oldsha1 : NULL,
404 flags, UPDATE_REFS_DIE_ON_ERR);
405 }