summaryrefslogtreecommitdiff
path: root/builtin/update-ref.c
blob: e4c0854e9fc58b6fa6b96e3216d417de3245c02e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
#include "cache.h"
#include "refs.h"
#include "builtin.h"
#include "parse-options.h"
#include "quote.h"
#include "argv-array.h"
 
static const char * const git_update_ref_usage[] = {
	N_("git update-ref [options] -d <refname> [<oldval>]"),
	N_("git update-ref [options]    <refname> <newval> [<oldval>]"),
	N_("git update-ref [options] --stdin [-z]"),
	NULL
};
 
static int updates_alloc;
static int updates_count;
static struct ref_update **updates;
 
static char line_termination = '\n';
static int update_flags;
 
static struct ref_update *update_alloc(void)
{
	struct ref_update *update;
 
	/* Allocate and zero-init a struct ref_update */
	update = xcalloc(1, sizeof(*update));
	ALLOC_GROW(updates, updates_count + 1, updates_alloc);
	updates[updates_count++] = update;
 
	/* Store and reset accumulated options */
	update->flags = update_flags;
	update_flags = 0;
 
	return update;
}
 
static void update_store_new_sha1(const char *command,
				  struct ref_update *update,
				  const char *newvalue)
{
	if (*newvalue && get_sha1(newvalue, update->new_sha1))
		die("%s %s: invalid <newvalue>: %s",
		    command, update->ref_name, newvalue);
}
 
static void update_store_old_sha1(const char *command,
				  struct ref_update *update,
				  const char *oldvalue)
{
	if (*oldvalue && get_sha1(oldvalue, update->old_sha1))
		die("%s %s: invalid <oldvalue>: %s",
		    command, update->ref_name, oldvalue);
 
	/* We have an old value if non-empty, or if empty without -z */
	update->have_old = *oldvalue || line_termination;
}
 
/*
 * Parse one whitespace- or NUL-terminated, possibly C-quoted argument
 * and append the result to arg.  Return a pointer to the terminator.
 * Die if there is an error in how the argument is C-quoted.  This
 * function is only used if not -z.
 */
static const char *parse_arg(const char *next, struct strbuf *arg)
{
	if (*next == '"') {
		const char *orig = next;
 
		if (unquote_c_style(arg, next, &next))
			die("badly quoted argument: %s", orig);
		if (*next && !isspace(*next))
			die("unexpected character after quoted argument: %s", orig);
	} else {
		while (*next && !isspace(*next))
			strbuf_addch(arg, *next++);
	}
 
	return next;
}
 
/*
 * Parse the reference name immediately after "command SP".  If not
 * -z, then handle C-quoting.  Return a pointer to a newly allocated
 * string containing the name of the reference, or NULL if there was
 * an error.  Update *next to point at the character that terminates
 * the argument.  Die if C-quoting is malformed or the reference name
 * is invalid.
 */
static char *parse_refname(struct strbuf *input, const char **next)
{
	struct strbuf ref = STRBUF_INIT;
 
	if (line_termination) {
		/* Without -z, use the next argument */
		*next = parse_arg(*next, &ref);
	} else {
		/* With -z, use everything up to the next NUL */
		strbuf_addstr(&ref, *next);
		*next += ref.len;
	}
 
	if (!ref.len) {
		strbuf_release(&ref);
		return NULL;
	}
 
	if (check_refname_format(ref.buf, REFNAME_ALLOW_ONELEVEL))
		die("invalid ref format: %s", ref.buf);
 
	return strbuf_detach(&ref, NULL);
}
 
/*
 * Parse a SP/NUL separator followed by the next SP- or NUL-terminated
 * argument, if any.  If there is an argument, write it to arg, set
 * *next to point at the character terminating the argument, and
 * return 0.  If there is no argument at all (not even the empty
 * string), return a non-zero result and leave *next unchanged.
 */
static int parse_next_arg(struct strbuf *input, const char **next,
			  struct strbuf *arg)
{
	strbuf_reset(arg);
	if (line_termination) {
		/* Without -z, consume SP and use next argument */
		if (!**next || **next == line_termination)
			return -1;
		if (**next != ' ')
			die("expected SP but got: %s", *next);
		(*next)++;
		*next = parse_arg(*next, arg);
	} else {
		/* With -z, read the next NUL-terminated line */
		if (**next)
			die("expected NUL but got: %s", *next);
		(*next)++;
		if (*next == input->buf + input->len)
			return -1;
		strbuf_addstr(arg, *next);
		*next += arg->len;
	}
	return 0;
}
 
 
/*
 * The following five parse_cmd_*() functions parse the corresponding
 * command.  In each case, next points at the character following the
 * command name and the following space.  They each return a pointer
 * to the character terminating the command, and die with an
 * explanatory message if there are any parsing problems.  All of
 * these functions handle either text or binary format input,
 * depending on how line_termination is set.
 */
 
static const char *parse_cmd_update(struct strbuf *input, const char *next)
{
	struct strbuf newvalue = STRBUF_INIT;
	struct strbuf oldvalue = STRBUF_INIT;
	struct ref_update *update;
 
	update = update_alloc();
 
	update->ref_name = parse_refname(input, &next);
	if (!update->ref_name)
		die("update line missing <ref>");
 
	if (!parse_next_arg(input, &next, &newvalue))
		update_store_new_sha1("update", update, newvalue.buf);
	else
		die("update %s missing <newvalue>", update->ref_name);
 
	if (!parse_next_arg(input, &next, &oldvalue)) {
		update_store_old_sha1("update", update, oldvalue.buf);
		if (*next != line_termination)
			die("update %s has extra input: %s", update->ref_name, next);
	} else if (!line_termination)
		die("update %s missing [<oldvalue>] NUL", update->ref_name);
 
	return next;
}
 
static const char *parse_cmd_create(struct strbuf *input, const char *next)
{
	struct strbuf newvalue = STRBUF_INIT;
	struct ref_update *update;
 
	update = update_alloc();
 
	update->ref_name = parse_refname(input, &next);
	if (!update->ref_name)
		die("create line missing <ref>");
 
	if (!parse_next_arg(input, &next, &newvalue))
		update_store_new_sha1("create", update, newvalue.buf);
	else
		die("create %s missing <newvalue>", update->ref_name);
 
	if (is_null_sha1(update->new_sha1))
		die("create %s given zero <newvalue>", update->ref_name);
 
	if (*next != line_termination)
		die("create %s has extra input: %s", update->ref_name, next);
 
	return next;
}
 
static const char *parse_cmd_delete(struct strbuf *input, const char *next)
{
	struct strbuf oldvalue = STRBUF_INIT;
	struct ref_update *update;
 
	update = update_alloc();
 
	update->ref_name = parse_refname(input, &next);
	if (!update->ref_name)
		die("delete line missing <ref>");
 
	if (!parse_next_arg(input, &next, &oldvalue)) {
		update_store_old_sha1("delete", update, oldvalue.buf);
		if (update->have_old && is_null_sha1(update->old_sha1))
			die("delete %s given zero <oldvalue>", update->ref_name);
	} else if (!line_termination)
		die("delete %s missing [<oldvalue>] NUL", update->ref_name);
 
	if (*next != line_termination)
		die("delete %s has extra input: %s", update->ref_name, next);
 
	return next;
}
 
static const char *parse_cmd_verify(struct strbuf *input, const char *next)
{
	struct strbuf value = STRBUF_INIT;
	struct ref_update *update;
 
	update = update_alloc();
 
	update->ref_name = parse_refname(input, &next);
	if (!update->ref_name)
		die("verify line missing <ref>");
 
	if (!parse_next_arg(input, &next, &value)) {
		update_store_old_sha1("verify", update, value.buf);
		hashcpy(update->new_sha1, update->old_sha1);
	} else if (!line_termination)
		die("verify %s missing [<oldvalue>] NUL", update->ref_name);
 
	if (*next != line_termination)
		die("verify %s has extra input: %s", update->ref_name, next);
 
	return next;
}
 
static const char *parse_cmd_option(struct strbuf *input, const char *next)
{
	if (!strncmp(next, "no-deref", 8) && next[8] == line_termination)
		update_flags |= REF_NODEREF;
	else
		die("option unknown: %s", next);
	return next + 8;
}
 
static void update_refs_stdin(void)
{
	struct strbuf input = STRBUF_INIT;
	const char *next;
 
	if (strbuf_read(&input, 0, 1000) < 0)
		die_errno("could not read from stdin");
	next = input.buf;
	/* Read each line dispatch its command */
	while (next < input.buf + input.len) {
		if (*next == line_termination)
			die("empty command in input");
		else if (isspace(*next))
			die("whitespace before command: %s", next);
		else if (starts_with(next, "update "))
			next = parse_cmd_update(&input, next + 7);
		else if (starts_with(next, "create "))
			next = parse_cmd_create(&input, next + 7);
		else if (starts_with(next, "delete "))
			next = parse_cmd_delete(&input, next + 7);
		else if (starts_with(next, "verify "))
			next = parse_cmd_verify(&input, next + 7);
		else if (starts_with(next, "option "))
			next = parse_cmd_option(&input, next + 7);
		else
			die("unknown command: %s", next);
 
		next++;
	}
 
	strbuf_release(&input);
}
 
int cmd_update_ref(int argc, const char **argv, const char *prefix)
{
	const char *refname, *oldval, *msg = NULL;
	unsigned char sha1[20], oldsha1[20];
	int delete = 0, no_deref = 0, read_stdin = 0, end_null = 0, flags = 0;
	struct option options[] = {
		OPT_STRING( 'm', NULL, &msg, N_("reason"), N_("reason of the update")),
		OPT_BOOL('d', NULL, &delete, N_("delete the reference")),
		OPT_BOOL( 0 , "no-deref", &no_deref,
					N_("update <refname> not the one it points to")),
		OPT_BOOL('z', NULL, &end_null, N_("stdin has NUL-terminated arguments")),
		OPT_BOOL( 0 , "stdin", &read_stdin, N_("read updates from stdin")),
		OPT_END(),
	};
 
	git_config(git_default_config, NULL);
	argc = parse_options(argc, argv, prefix, options, git_update_ref_usage,
			     0);
	if (msg && !*msg)
		die("Refusing to perform update with empty message.");
 
	if (read_stdin) {
		if (delete || no_deref || argc > 0)
			usage_with_options(git_update_ref_usage, options);
		if (end_null)
			line_termination = '\0';
		update_refs_stdin();
		return update_refs(msg, updates, updates_count,
				   UPDATE_REFS_DIE_ON_ERR);
	}
 
	if (end_null)
		usage_with_options(git_update_ref_usage, options);
 
	if (delete) {
		if (argc < 1 || argc > 2)
			usage_with_options(git_update_ref_usage, options);
		refname = argv[0];
		oldval = argv[1];
	} else {
		const char *value;
		if (argc < 2 || argc > 3)
			usage_with_options(git_update_ref_usage, options);
		refname = argv[0];
		value = argv[1];
		oldval = argv[2];
		if (get_sha1(value, sha1))
			die("%s: not a valid SHA1", value);
	}
 
	hashclr(oldsha1); /* all-zero hash in case oldval is the empty string */
	if (oldval && *oldval && get_sha1(oldval, oldsha1))
		die("%s: not a valid old SHA1", oldval);
 
	if (no_deref)
		flags = REF_NODEREF;
	if (delete)
		return delete_ref(refname, oldval ? oldsha1 : NULL, flags);
	else
		return update_ref(msg, refname, sha1, oldval ? oldsha1 : NULL,
				  flags, UPDATE_REFS_DIE_ON_ERR);
}