Andrew's git - gitweb.git/blob - 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
   9static 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
  16static char line_termination = '\n';
  17static int update_flags;
  18static unsigned create_reflog_flag;
  19static 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 */
  27static 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 */
  52static 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 */
  97static int parse_next_oid(struct strbuf *input, const char **next,
  98                          struct object_id *oid,
  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_oid(arg.buf, oid))
 119                                goto invalid;
 120                } else {
 121                        /* Without -z, an empty value means all zeros: */
 122                        oidclr(oid);
 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_oid(arg.buf, oid))
 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                        oidclr(oid);
 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
 180static 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        struct object_id new_oid, old_oid;
 186        int have_old;
 187
 188        refname = parse_refname(input, &next);
 189        if (!refname)
 190                die("update: missing <ref>");
 191
 192        if (parse_next_oid(input, &next, &new_oid, "update", refname,
 193                           PARSE_SHA1_ALLOW_EMPTY))
 194                die("update %s: missing <newvalue>", refname);
 195
 196        have_old = !parse_next_oid(input, &next, &old_oid, "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_oid, have_old ? &old_oid : 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        struct object_id new_oid;
 221
 222        refname = parse_refname(input, &next);
 223        if (!refname)
 224                die("create: missing <ref>");
 225
 226        if (parse_next_oid(input, &next, &new_oid, "create", refname, 0))
 227                die("create %s: missing <newvalue>", refname);
 228
 229        if (is_null_oid(&new_oid))
 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_oid,
 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        struct object_id old_oid;
 253        int have_old;
 254
 255        refname = parse_refname(input, &next);
 256        if (!refname)
 257                die("delete: missing <ref>");
 258
 259        if (parse_next_oid(input, &next, &old_oid, "delete", refname,
 260                           PARSE_SHA1_OLD)) {
 261                have_old = 0;
 262        } else {
 263                if (is_null_oid(&old_oid))
 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_oid : 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        struct object_id old_oid;
 289
 290        refname = parse_refname(input, &next);
 291        if (!refname)
 292                die("verify: missing <ref>");
 293
 294        if (parse_next_oid(input, &next, &old_oid, "verify", refname,
 295                           PARSE_SHA1_OLD))
 296                oidclr(&old_oid);
 297
 298        if (*next != line_termination)
 299                die("verify %s: extra input: %s", refname, next);
 300
 301        if (ref_transaction_verify(transaction, refname, &old_oid,
 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_NO_DEREF;
 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        struct object_id oid, oldoid;
 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_oid(value, &oid))
 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                        oidclr(&oldoid);
 425                else if (get_oid(oldval, &oldoid))
 426                        die("%s: not a valid old SHA1", oldval);
 427        }
 428
 429        if (no_deref)
 430                flags = REF_NO_DEREF;
 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(msg, refname,
 437                                  (oldval && !is_null_oid(&oldoid)) ? &oldoid : NULL,
 438                                  flags);
 439        else
 440                return update_ref(msg, refname, &oid, oldval ? &oldoid : NULL,
 441                                  flags | create_reflog_flag,
 442                                  UPDATE_REFS_DIE_ON_ERR);
 443}