diff options
Diffstat (limited to 'builtin/update-ref.c')
| -rw-r--r-- | builtin/update-ref.c | 422 |
1 files changed, 422 insertions, 0 deletions
diff --git a/builtin/update-ref.c b/builtin/update-ref.c new file mode 100644 index 0000000000..3d79a46b03 --- /dev/null +++ b/builtin/update-ref.c @@ -0,0 +1,422 @@ +#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> [<old-val>]"), + N_("git update-ref [<options>] <refname> <new-val> [<old-val>]"), + N_("git update-ref [<options>] --stdin [-z]"), + NULL +}; + +static char line_termination = '\n'; +static int update_flags; +static const char *msg; + +/* + * 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); +} + +/* + * The value being parsed is <oldvalue> (as opposed to <newvalue>; the + * difference affects which error messages are generated): + */ +#define PARSE_SHA1_OLD 0x01 + +/* + * For backwards compatibility, accept an empty string for update's + * <newvalue> in binary mode to be equivalent to specifying zeros. + */ +#define PARSE_SHA1_ALLOW_EMPTY 0x02 + +/* + * Parse an argument separator followed by the next argument, if any. + * If there is an argument, convert it to a SHA-1, write it to sha1, + * 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 1 and leave *next unchanged. If the value is + * provided but cannot be converted to a SHA-1, die. flags can + * include PARSE_SHA1_OLD and/or PARSE_SHA1_ALLOW_EMPTY. + */ +static int parse_next_sha1(struct strbuf *input, const char **next, + unsigned char *sha1, + const char *command, const char *refname, + int flags) +{ + struct strbuf arg = STRBUF_INIT; + int ret = 0; + + if (*next == input->buf + input->len) + goto eof; + + if (line_termination) { + /* Without -z, consume SP and use next argument */ + if (!**next || **next == line_termination) + return 1; + if (**next != ' ') + die("%s %s: expected SP but got: %s", + command, refname, *next); + (*next)++; + *next = parse_arg(*next, &arg); + if (arg.len) { + if (get_sha1(arg.buf, sha1)) + goto invalid; + } else { + /* Without -z, an empty value means all zeros: */ + hashclr(sha1); + } + } else { + /* With -z, read the next NUL-terminated line */ + if (**next) + die("%s %s: expected NUL but got: %s", + command, refname, *next); + (*next)++; + if (*next == input->buf + input->len) + goto eof; + strbuf_addstr(&arg, *next); + *next += arg.len; + + if (arg.len) { + if (get_sha1(arg.buf, sha1)) + goto invalid; + } else if (flags & PARSE_SHA1_ALLOW_EMPTY) { + /* With -z, treat an empty value as all zeros: */ + warning("%s %s: missing <newvalue>, treating as zero", + command, refname); + hashclr(sha1); + } else { + /* + * With -z, an empty non-required value means + * unspecified: + */ + ret = 1; + } + } + + strbuf_release(&arg); + + return ret; + + invalid: + die(flags & PARSE_SHA1_OLD ? + "%s %s: invalid <oldvalue>: %s" : + "%s %s: invalid <newvalue>: %s", + command, refname, arg.buf); + + eof: + die(flags & PARSE_SHA1_OLD ? + "%s %s: unexpected end of input when reading <oldvalue>" : + "%s %s: unexpected end of input when reading <newvalue>", + command, refname); +} + + +/* + * 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 ref_transaction *transaction, + struct strbuf *input, const char *next) +{ + struct strbuf err = STRBUF_INIT; + char *refname; + unsigned char new_sha1[20]; + unsigned char old_sha1[20]; + int have_old; + + refname = parse_refname(input, &next); + if (!refname) + die("update: missing <ref>"); + + if (parse_next_sha1(input, &next, new_sha1, "update", refname, + PARSE_SHA1_ALLOW_EMPTY)) + die("update %s: missing <newvalue>", refname); + + have_old = !parse_next_sha1(input, &next, old_sha1, "update", refname, + PARSE_SHA1_OLD); + + if (*next != line_termination) + die("update %s: extra input: %s", refname, next); + + if (ref_transaction_update(transaction, refname, + new_sha1, have_old ? old_sha1 : NULL, + update_flags, msg, &err)) + die("%s", err.buf); + + update_flags = 0; + free(refname); + strbuf_release(&err); + + return next; +} + +static const char *parse_cmd_create(struct ref_transaction *transaction, + struct strbuf *input, const char *next) +{ + struct strbuf err = STRBUF_INIT; + char *refname; + unsigned char new_sha1[20]; + + refname = parse_refname(input, &next); + if (!refname) + die("create: missing <ref>"); + + if (parse_next_sha1(input, &next, new_sha1, "create", refname, 0)) + die("create %s: missing <newvalue>", refname); + + if (is_null_sha1(new_sha1)) + die("create %s: zero <newvalue>", refname); + + if (*next != line_termination) + die("create %s: extra input: %s", refname, next); + + if (ref_transaction_create(transaction, refname, new_sha1, + update_flags, msg, &err)) + die("%s", err.buf); + + update_flags = 0; + free(refname); + strbuf_release(&err); + + return next; +} + +static const char *parse_cmd_delete(struct ref_transaction *transaction, + struct strbuf *input, const char *next) +{ + struct strbuf err = STRBUF_INIT; + char *refname; + unsigned char old_sha1[20]; + int have_old; + + refname = parse_refname(input, &next); + if (!refname) + die("delete: missing <ref>"); + + if (parse_next_sha1(input, &next, old_sha1, "delete", refname, + PARSE_SHA1_OLD)) { + have_old = 0; + } else { + if (is_null_sha1(old_sha1)) + die("delete %s: zero <oldvalue>", refname); + have_old = 1; + } + + if (*next != line_termination) + die("delete %s: extra input: %s", refname, next); + + if (ref_transaction_delete(transaction, refname, + have_old ? old_sha1 : NULL, + update_flags, msg, &err)) + die("%s", err.buf); + + update_flags = 0; + free(refname); + strbuf_release(&err); + + return next; +} + +static const char *parse_cmd_verify(struct ref_transaction *transaction, + struct strbuf *input, const char *next) +{ + struct strbuf err = STRBUF_INIT; + char *refname; + unsigned char old_sha1[20]; + + refname = parse_refname(input, &next); + if (!refname) + die("verify: missing <ref>"); + + if (parse_next_sha1(input, &next, old_sha1, "verify", refname, + PARSE_SHA1_OLD)) + hashclr(old_sha1); + + if (*next != line_termination) + die("verify %s: extra input: %s", refname, next); + + if (ref_transaction_verify(transaction, refname, old_sha1, + update_flags, &err)) + die("%s", err.buf); + + update_flags = 0; + free(refname); + strbuf_release(&err); + + 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(struct ref_transaction *transaction) +{ + 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(transaction, &input, next + 7); + else if (starts_with(next, "create ")) + next = parse_cmd_create(transaction, &input, next + 7); + else if (starts_with(next, "delete ")) + next = parse_cmd_delete(transaction, &input, next + 7); + else if (starts_with(next, "verify ")) + next = parse_cmd_verify(transaction, &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; + unsigned char sha1[20], oldsha1[20]; + int delete = 0, no_deref = 0, read_stdin = 0, end_null = 0; + unsigned int 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) { + struct strbuf err = STRBUF_INIT; + struct ref_transaction *transaction; + + transaction = ref_transaction_begin(&err); + if (!transaction) + die("%s", err.buf); + if (delete || no_deref || argc > 0) + usage_with_options(git_update_ref_usage, options); + if (end_null) + line_termination = '\0'; + update_refs_stdin(transaction); + if (ref_transaction_commit(transaction, &err)) + die("%s", err.buf); + ref_transaction_free(transaction); + strbuf_release(&err); + return 0; + } + + 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); +} |