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[thirdparty/git.git] / builtin / update-ref.c
1 #include "cache.h"
2 #include "config.h"
3 #include "refs.h"
4 #include "builtin.h"
5 #include "parse-options.h"
6 #include "quote.h"
7 #include "argv-array.h"
8
9 static const char * const git_update_ref_usage[] = {
10 N_("git update-ref [<options>] -d <refname> [<old-val>]"),
11 N_("git update-ref [<options>] <refname> <new-val> [<old-val>]"),
12 N_("git update-ref [<options>] --stdin [-z]"),
13 NULL
14 };
15
16 static char line_termination = '\n';
17 static int update_flags;
18 static unsigned create_reflog_flag;
19 static const char *msg;
20
21 /*
22 * Parse one whitespace- or NUL-terminated, possibly C-quoted argument
23 * and append the result to arg. Return a pointer to the terminator.
24 * Die if there is an error in how the argument is C-quoted. This
25 * function is only used if not -z.
26 */
27 static const char *parse_arg(const char *next, struct strbuf *arg)
28 {
29 if (*next == '"') {
30 const char *orig = next;
31
32 if (unquote_c_style(arg, next, &next))
33 die("badly quoted argument: %s", orig);
34 if (*next && !isspace(*next))
35 die("unexpected character after quoted argument: %s", orig);
36 } else {
37 while (*next && !isspace(*next))
38 strbuf_addch(arg, *next++);
39 }
40
41 return next;
42 }
43
44 /*
45 * Parse the reference name immediately after "command SP". If not
46 * -z, then handle C-quoting. Return a pointer to a newly allocated
47 * string containing the name of the reference, or NULL if there was
48 * an error. Update *next to point at the character that terminates
49 * the argument. Die if C-quoting is malformed or the reference name
50 * is invalid.
51 */
52 static char *parse_refname(struct strbuf *input, const char **next)
53 {
54 struct strbuf ref = STRBUF_INIT;
55
56 if (line_termination) {
57 /* Without -z, use the next argument */
58 *next = parse_arg(*next, &ref);
59 } else {
60 /* With -z, use everything up to the next NUL */
61 strbuf_addstr(&ref, *next);
62 *next += ref.len;
63 }
64
65 if (!ref.len) {
66 strbuf_release(&ref);
67 return NULL;
68 }
69
70 if (check_refname_format(ref.buf, REFNAME_ALLOW_ONELEVEL))
71 die("invalid ref format: %s", ref.buf);
72
73 return strbuf_detach(&ref, NULL);
74 }
75
76 /*
77 * The value being parsed is <oldvalue> (as opposed to <newvalue>; the
78 * difference affects which error messages are generated):
79 */
80 #define PARSE_SHA1_OLD 0x01
81
82 /*
83 * For backwards compatibility, accept an empty string for update's
84 * <newvalue> in binary mode to be equivalent to specifying zeros.
85 */
86 #define PARSE_SHA1_ALLOW_EMPTY 0x02
87
88 /*
89 * Parse an argument separator followed by the next argument, if any.
90 * If there is an argument, convert it to a SHA-1, write it to sha1,
91 * set *next to point at the character terminating the argument, and
92 * return 0. If there is no argument at all (not even the empty
93 * string), return 1 and leave *next unchanged. If the value is
94 * provided but cannot be converted to a SHA-1, die. flags can
95 * include PARSE_SHA1_OLD and/or PARSE_SHA1_ALLOW_EMPTY.
96 */
97 static int parse_next_sha1(struct strbuf *input, const char **next,
98 unsigned char *sha1,
99 const char *command, const char *refname,
100 int flags)
101 {
102 struct strbuf arg = STRBUF_INIT;
103 int ret = 0;
104
105 if (*next == input->buf + input->len)
106 goto eof;
107
108 if (line_termination) {
109 /* Without -z, consume SP and use next argument */
110 if (!**next || **next == line_termination)
111 return 1;
112 if (**next != ' ')
113 die("%s %s: expected SP but got: %s",
114 command, refname, *next);
115 (*next)++;
116 *next = parse_arg(*next, &arg);
117 if (arg.len) {
118 if (get_sha1(arg.buf, sha1))
119 goto invalid;
120 } else {
121 /* Without -z, an empty value means all zeros: */
122 hashclr(sha1);
123 }
124 } else {
125 /* With -z, read the next NUL-terminated line */
126 if (**next)
127 die("%s %s: expected NUL but got: %s",
128 command, refname, *next);
129 (*next)++;
130 if (*next == input->buf + input->len)
131 goto eof;
132 strbuf_addstr(&arg, *next);
133 *next += arg.len;
134
135 if (arg.len) {
136 if (get_sha1(arg.buf, sha1))
137 goto invalid;
138 } else if (flags & PARSE_SHA1_ALLOW_EMPTY) {
139 /* With -z, treat an empty value as all zeros: */
140 warning("%s %s: missing <newvalue>, treating as zero",
141 command, refname);
142 hashclr(sha1);
143 } else {
144 /*
145 * With -z, an empty non-required value means
146 * unspecified:
147 */
148 ret = 1;
149 }
150 }
151
152 strbuf_release(&arg);
153
154 return ret;
155
156 invalid:
157 die(flags & PARSE_SHA1_OLD ?
158 "%s %s: invalid <oldvalue>: %s" :
159 "%s %s: invalid <newvalue>: %s",
160 command, refname, arg.buf);
161
162 eof:
163 die(flags & PARSE_SHA1_OLD ?
164 "%s %s: unexpected end of input when reading <oldvalue>" :
165 "%s %s: unexpected end of input when reading <newvalue>",
166 command, refname);
167 }
168
169
170 /*
171 * The following five parse_cmd_*() functions parse the corresponding
172 * command. In each case, next points at the character following the
173 * command name and the following space. They each return a pointer
174 * to the character terminating the command, and die with an
175 * explanatory message if there are any parsing problems. All of
176 * these functions handle either text or binary format input,
177 * depending on how line_termination is set.
178 */
179
180 static const char *parse_cmd_update(struct ref_transaction *transaction,
181 struct strbuf *input, const char *next)
182 {
183 struct strbuf err = STRBUF_INIT;
184 char *refname;
185 unsigned char new_sha1[20];
186 unsigned char old_sha1[20];
187 int have_old;
188
189 refname = parse_refname(input, &next);
190 if (!refname)
191 die("update: missing <ref>");
192
193 if (parse_next_sha1(input, &next, new_sha1, "update", refname,
194 PARSE_SHA1_ALLOW_EMPTY))
195 die("update %s: missing <newvalue>", refname);
196
197 have_old = !parse_next_sha1(input, &next, old_sha1, "update", refname,
198 PARSE_SHA1_OLD);
199
200 if (*next != line_termination)
201 die("update %s: extra input: %s", refname, next);
202
203 if (ref_transaction_update(transaction, refname,
204 new_sha1, have_old ? old_sha1 : NULL,
205 update_flags | create_reflog_flag,
206 msg, &err))
207 die("%s", err.buf);
208
209 update_flags = 0;
210 free(refname);
211 strbuf_release(&err);
212
213 return next;
214 }
215
216 static const char *parse_cmd_create(struct ref_transaction *transaction,
217 struct strbuf *input, const char *next)
218 {
219 struct strbuf err = STRBUF_INIT;
220 char *refname;
221 unsigned char new_sha1[20];
222
223 refname = parse_refname(input, &next);
224 if (!refname)
225 die("create: missing <ref>");
226
227 if (parse_next_sha1(input, &next, new_sha1, "create", refname, 0))
228 die("create %s: missing <newvalue>", refname);
229
230 if (is_null_sha1(new_sha1))
231 die("create %s: zero <newvalue>", refname);
232
233 if (*next != line_termination)
234 die("create %s: extra input: %s", refname, next);
235
236 if (ref_transaction_create(transaction, refname, new_sha1,
237 update_flags | create_reflog_flag,
238 msg, &err))
239 die("%s", err.buf);
240
241 update_flags = 0;
242 free(refname);
243 strbuf_release(&err);
244
245 return next;
246 }
247
248 static const char *parse_cmd_delete(struct ref_transaction *transaction,
249 struct strbuf *input, const char *next)
250 {
251 struct strbuf err = STRBUF_INIT;
252 char *refname;
253 unsigned char old_sha1[20];
254 int have_old;
255
256 refname = parse_refname(input, &next);
257 if (!refname)
258 die("delete: missing <ref>");
259
260 if (parse_next_sha1(input, &next, old_sha1, "delete", refname,
261 PARSE_SHA1_OLD)) {
262 have_old = 0;
263 } else {
264 if (is_null_sha1(old_sha1))
265 die("delete %s: zero <oldvalue>", refname);
266 have_old = 1;
267 }
268
269 if (*next != line_termination)
270 die("delete %s: extra input: %s", refname, next);
271
272 if (ref_transaction_delete(transaction, refname,
273 have_old ? old_sha1 : NULL,
274 update_flags, msg, &err))
275 die("%s", err.buf);
276
277 update_flags = 0;
278 free(refname);
279 strbuf_release(&err);
280
281 return next;
282 }
283
284 static const char *parse_cmd_verify(struct ref_transaction *transaction,
285 struct strbuf *input, const char *next)
286 {
287 struct strbuf err = STRBUF_INIT;
288 char *refname;
289 unsigned char old_sha1[20];
290
291 refname = parse_refname(input, &next);
292 if (!refname)
293 die("verify: missing <ref>");
294
295 if (parse_next_sha1(input, &next, old_sha1, "verify", refname,
296 PARSE_SHA1_OLD))
297 hashclr(old_sha1);
298
299 if (*next != line_termination)
300 die("verify %s: extra input: %s", refname, next);
301
302 if (ref_transaction_verify(transaction, refname, old_sha1,
303 update_flags, &err))
304 die("%s", err.buf);
305
306 update_flags = 0;
307 free(refname);
308 strbuf_release(&err);
309
310 return next;
311 }
312
313 static const char *parse_cmd_option(struct strbuf *input, const char *next)
314 {
315 if (!strncmp(next, "no-deref", 8) && next[8] == line_termination)
316 update_flags |= REF_NODEREF;
317 else
318 die("option unknown: %s", next);
319 return next + 8;
320 }
321
322 static void update_refs_stdin(struct ref_transaction *transaction)
323 {
324 struct strbuf input = STRBUF_INIT;
325 const char *next;
326
327 if (strbuf_read(&input, 0, 1000) < 0)
328 die_errno("could not read from stdin");
329 next = input.buf;
330 /* Read each line dispatch its command */
331 while (next < input.buf + input.len) {
332 if (*next == line_termination)
333 die("empty command in input");
334 else if (isspace(*next))
335 die("whitespace before command: %s", next);
336 else if (starts_with(next, "update "))
337 next = parse_cmd_update(transaction, &input, next + 7);
338 else if (starts_with(next, "create "))
339 next = parse_cmd_create(transaction, &input, next + 7);
340 else if (starts_with(next, "delete "))
341 next = parse_cmd_delete(transaction, &input, next + 7);
342 else if (starts_with(next, "verify "))
343 next = parse_cmd_verify(transaction, &input, next + 7);
344 else if (starts_with(next, "option "))
345 next = parse_cmd_option(&input, next + 7);
346 else
347 die("unknown command: %s", next);
348
349 next++;
350 }
351
352 strbuf_release(&input);
353 }
354
355 int cmd_update_ref(int argc, const char **argv, const char *prefix)
356 {
357 const char *refname, *oldval;
358 unsigned char sha1[20], oldsha1[20];
359 int delete = 0, no_deref = 0, read_stdin = 0, end_null = 0;
360 unsigned int flags = 0;
361 int create_reflog = 0;
362 struct option options[] = {
363 OPT_STRING( 'm', NULL, &msg, N_("reason"), N_("reason of the update")),
364 OPT_BOOL('d', NULL, &delete, N_("delete the reference")),
365 OPT_BOOL( 0 , "no-deref", &no_deref,
366 N_("update <refname> not the one it points to")),
367 OPT_BOOL('z', NULL, &end_null, N_("stdin has NUL-terminated arguments")),
368 OPT_BOOL( 0 , "stdin", &read_stdin, N_("read updates from stdin")),
369 OPT_BOOL( 0 , "create-reflog", &create_reflog, N_("create a reflog")),
370 OPT_END(),
371 };
372
373 git_config(git_default_config, NULL);
374 argc = parse_options(argc, argv, prefix, options, git_update_ref_usage,
375 0);
376 if (msg && !*msg)
377 die("Refusing to perform update with empty message.");
378
379 create_reflog_flag = create_reflog ? REF_FORCE_CREATE_REFLOG : 0;
380
381 if (read_stdin) {
382 struct strbuf err = STRBUF_INIT;
383 struct ref_transaction *transaction;
384
385 transaction = ref_transaction_begin(&err);
386 if (!transaction)
387 die("%s", err.buf);
388 if (delete || no_deref || argc > 0)
389 usage_with_options(git_update_ref_usage, options);
390 if (end_null)
391 line_termination = '\0';
392 update_refs_stdin(transaction);
393 if (ref_transaction_commit(transaction, &err))
394 die("%s", err.buf);
395 ref_transaction_free(transaction);
396 strbuf_release(&err);
397 return 0;
398 }
399
400 if (end_null)
401 usage_with_options(git_update_ref_usage, options);
402
403 if (delete) {
404 if (argc < 1 || argc > 2)
405 usage_with_options(git_update_ref_usage, options);
406 refname = argv[0];
407 oldval = argv[1];
408 } else {
409 const char *value;
410 if (argc < 2 || argc > 3)
411 usage_with_options(git_update_ref_usage, options);
412 refname = argv[0];
413 value = argv[1];
414 oldval = argv[2];
415 if (get_sha1(value, sha1))
416 die("%s: not a valid SHA1", value);
417 }
418
419 if (oldval) {
420 if (!*oldval)
421 /*
422 * The empty string implies that the reference
423 * must not already exist:
424 */
425 hashclr(oldsha1);
426 else if (get_sha1(oldval, oldsha1))
427 die("%s: not a valid old SHA1", oldval);
428 }
429
430 if (no_deref)
431 flags = REF_NODEREF;
432 if (delete)
433 /*
434 * For purposes of backwards compatibility, we treat
435 * NULL_SHA1 as "don't care" here:
436 */
437 return delete_ref(msg, refname,
438 (oldval && !is_null_sha1(oldsha1)) ? oldsha1 : NULL,
439 flags);
440 else
441 return update_ref(msg, refname, sha1, oldval ? oldsha1 : NULL,
442 flags | create_reflog_flag,
443 UPDATE_REFS_DIE_ON_ERR);
444 }