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_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
 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        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
 216static 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
 248static 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
 284static 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
 313static 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
 322static 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
 355int 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}