Andrew's git - gitweb.git/blob - 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
   8static const char * const git_update_ref_usage[] = {
   9        N_("git update-ref [<options>] -d <refname> [<old-val>]"),
  10        N_("git update-ref [<options>]    <refname> <new-val> [<old-val>]"),
  11        N_("git update-ref [<options>] --stdin [-z]"),
  12        NULL
  13};
  14
  15static char line_termination = '\n';
  16static int update_flags;
  17static unsigned create_reflog_flag;
  18static const char *msg;
  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 */
  26static 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 */
  51static 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 */
  96static 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
 179static const char *parse_cmd_update(struct ref_transaction *transaction,
 180                                    struct strbuf *input, const char *next)
 181{
 182        struct strbuf err = STRBUF_INIT;
 183        char *refname;
 184        unsigned char new_sha1[20];
 185        unsigned char old_sha1[20];
 186        int have_old;
 187
 188        refname = parse_refname(input, &next);
 189        if (!refname)
 190                die("update: missing <ref>");
 191
 192        if (parse_next_sha1(input, &next, new_sha1, "update", refname,
 193                            PARSE_SHA1_ALLOW_EMPTY))
 194                die("update %s: missing <newvalue>", refname);
 195
 196        have_old = !parse_next_sha1(input, &next, old_sha1, "update", refname,
 197                                    PARSE_SHA1_OLD);
 198
 199        if (*next != line_termination)
 200                die("update %s: extra input: %s", refname, next);
 201
 202        if (ref_transaction_update(transaction, refname,
 203                                   new_sha1, have_old ? old_sha1 : NULL,
 204                                   update_flags | create_reflog_flag,
 205                                   msg, &err))
 206                die("%s", err.buf);
 207
 208        update_flags = 0;
 209        free(refname);
 210        strbuf_release(&err);
 211
 212        return next;
 213}
 214
 215static const char *parse_cmd_create(struct ref_transaction *transaction,
 216                                    struct strbuf *input, const char *next)
 217{
 218        struct strbuf err = STRBUF_INIT;
 219        char *refname;
 220        unsigned char new_sha1[20];
 221
 222        refname = parse_refname(input, &next);
 223        if (!refname)
 224                die("create: missing <ref>");
 225
 226        if (parse_next_sha1(input, &next, new_sha1, "create", refname, 0))
 227                die("create %s: missing <newvalue>", refname);
 228
 229        if (is_null_sha1(new_sha1))
 230                die("create %s: zero <newvalue>", refname);
 231
 232        if (*next != line_termination)
 233                die("create %s: extra input: %s", refname, next);
 234
 235        if (ref_transaction_create(transaction, refname, new_sha1,
 236                                   update_flags | create_reflog_flag,
 237                                   msg, &err))
 238                die("%s", err.buf);
 239
 240        update_flags = 0;
 241        free(refname);
 242        strbuf_release(&err);
 243
 244        return next;
 245}
 246
 247static const char *parse_cmd_delete(struct ref_transaction *transaction,
 248                                    struct strbuf *input, const char *next)
 249{
 250        struct strbuf err = STRBUF_INIT;
 251        char *refname;
 252        unsigned char old_sha1[20];
 253        int have_old;
 254
 255        refname = parse_refname(input, &next);
 256        if (!refname)
 257                die("delete: missing <ref>");
 258
 259        if (parse_next_sha1(input, &next, old_sha1, "delete", refname,
 260                            PARSE_SHA1_OLD)) {
 261                have_old = 0;
 262        } else {
 263                if (is_null_sha1(old_sha1))
 264                        die("delete %s: zero <oldvalue>", refname);
 265                have_old = 1;
 266        }
 267
 268        if (*next != line_termination)
 269                die("delete %s: extra input: %s", refname, next);
 270
 271        if (ref_transaction_delete(transaction, refname,
 272                                   have_old ? old_sha1 : NULL,
 273                                   update_flags, msg, &err))
 274                die("%s", err.buf);
 275
 276        update_flags = 0;
 277        free(refname);
 278        strbuf_release(&err);
 279
 280        return next;
 281}
 282
 283static const char *parse_cmd_verify(struct ref_transaction *transaction,
 284                                    struct strbuf *input, const char *next)
 285{
 286        struct strbuf err = STRBUF_INIT;
 287        char *refname;
 288        unsigned char old_sha1[20];
 289
 290        refname = parse_refname(input, &next);
 291        if (!refname)
 292                die("verify: missing <ref>");
 293
 294        if (parse_next_sha1(input, &next, old_sha1, "verify", refname,
 295                            PARSE_SHA1_OLD))
 296                hashclr(old_sha1);
 297
 298        if (*next != line_termination)
 299                die("verify %s: extra input: %s", refname, next);
 300
 301        if (ref_transaction_verify(transaction, refname, old_sha1,
 302                                   update_flags, &err))
 303                die("%s", err.buf);
 304
 305        update_flags = 0;
 306        free(refname);
 307        strbuf_release(&err);
 308
 309        return next;
 310}
 311
 312static const char *parse_cmd_option(struct strbuf *input, const char *next)
 313{
 314        if (!strncmp(next, "no-deref", 8) && next[8] == line_termination)
 315                update_flags |= REF_NODEREF;
 316        else
 317                die("option unknown: %s", next);
 318        return next + 8;
 319}
 320
 321static void update_refs_stdin(struct ref_transaction *transaction)
 322{
 323        struct strbuf input = STRBUF_INIT;
 324        const char *next;
 325
 326        if (strbuf_read(&input, 0, 1000) < 0)
 327                die_errno("could not read from stdin");
 328        next = input.buf;
 329        /* Read each line dispatch its command */
 330        while (next < input.buf + input.len) {
 331                if (*next == line_termination)
 332                        die("empty command in input");
 333                else if (isspace(*next))
 334                        die("whitespace before command: %s", next);
 335                else if (starts_with(next, "update "))
 336                        next = parse_cmd_update(transaction, &input, next + 7);
 337                else if (starts_with(next, "create "))
 338                        next = parse_cmd_create(transaction, &input, next + 7);
 339                else if (starts_with(next, "delete "))
 340                        next = parse_cmd_delete(transaction, &input, next + 7);
 341                else if (starts_with(next, "verify "))
 342                        next = parse_cmd_verify(transaction, &input, next + 7);
 343                else if (starts_with(next, "option "))
 344                        next = parse_cmd_option(&input, next + 7);
 345                else
 346                        die("unknown command: %s", next);
 347
 348                next++;
 349        }
 350
 351        strbuf_release(&input);
 352}
 353
 354int cmd_update_ref(int argc, const char **argv, const char *prefix)
 355{
 356        const char *refname, *oldval;
 357        unsigned char sha1[20], oldsha1[20];
 358        int delete = 0, no_deref = 0, read_stdin = 0, end_null = 0;
 359        unsigned int flags = 0;
 360        int create_reflog = 0;
 361        struct option options[] = {
 362                OPT_STRING( 'm', NULL, &msg, N_("reason"), N_("reason of the update")),
 363                OPT_BOOL('d', NULL, &delete, N_("delete the reference")),
 364                OPT_BOOL( 0 , "no-deref", &no_deref,
 365                                        N_("update <refname> not the one it points to")),
 366                OPT_BOOL('z', NULL, &end_null, N_("stdin has NUL-terminated arguments")),
 367                OPT_BOOL( 0 , "stdin", &read_stdin, N_("read updates from stdin")),
 368                OPT_BOOL( 0 , "create-reflog", &create_reflog, N_("create a reflog")),
 369                OPT_END(),
 370        };
 371
 372        git_config(git_default_config, NULL);
 373        argc = parse_options(argc, argv, prefix, options, git_update_ref_usage,
 374                             0);
 375        if (msg && !*msg)
 376                die("Refusing to perform update with empty message.");
 377
 378        create_reflog_flag = create_reflog ? REF_FORCE_CREATE_REFLOG : 0;
 379
 380        if (read_stdin) {
 381                struct strbuf err = STRBUF_INIT;
 382                struct ref_transaction *transaction;
 383
 384                transaction = ref_transaction_begin(&err);
 385                if (!transaction)
 386                        die("%s", err.buf);
 387                if (delete || no_deref || argc > 0)
 388                        usage_with_options(git_update_ref_usage, options);
 389                if (end_null)
 390                        line_termination = '\0';
 391                update_refs_stdin(transaction);
 392                if (ref_transaction_commit(transaction, &err))
 393                        die("%s", err.buf);
 394                ref_transaction_free(transaction);
 395                strbuf_release(&err);
 396                return 0;
 397        }
 398
 399        if (end_null)
 400                usage_with_options(git_update_ref_usage, options);
 401
 402        if (delete) {
 403                if (argc < 1 || argc > 2)
 404                        usage_with_options(git_update_ref_usage, options);
 405                refname = argv[0];
 406                oldval = argv[1];
 407        } else {
 408                const char *value;
 409                if (argc < 2 || argc > 3)
 410                        usage_with_options(git_update_ref_usage, options);
 411                refname = argv[0];
 412                value = argv[1];
 413                oldval = argv[2];
 414                if (get_sha1(value, sha1))
 415                        die("%s: not a valid SHA1", value);
 416        }
 417
 418        if (oldval) {
 419                if (!*oldval)
 420                        /*
 421                         * The empty string implies that the reference
 422                         * must not already exist:
 423                         */
 424                        hashclr(oldsha1);
 425                else if (get_sha1(oldval, oldsha1))
 426                        die("%s: not a valid old SHA1", oldval);
 427        }
 428
 429        if (no_deref)
 430                flags = REF_NODEREF;
 431        if (delete)
 432                /*
 433                 * For purposes of backwards compatibility, we treat
 434                 * NULL_SHA1 as "don't care" here:
 435                 */
 436                return delete_ref(refname,
 437                                  (oldval && !is_null_sha1(oldsha1)) ? oldsha1 : NULL,
 438                                  flags);
 439        else
 440                return update_ref(msg, refname, sha1, oldval ? oldsha1 : NULL,
 441                                  flags | create_reflog_flag,
 442                                  UPDATE_REFS_DIE_ON_ERR);
 443}