builtin/replace.c

   1 /*
   2  * Builtin "git replace"
   3  *
   4  * Copyright (c) 2008 Christian Couder <chriscool@tuxfamily.org>
   5  *
   6  * Based on builtin-tag.c by Kristian Høgsberg <krh@redhat.com>
   7  * and Carlos Rica <jasampler@gmail.com> that was itself based on
   8  * git-tag.sh and mktag.c by Linus Torvalds.
   9  */
  10
  11 #include "cache.h"
  12 #include "builtin.h"
  13 #include "refs.h"
  14 #include "parse-options.h"
  15
  16 static const char * const git_replace_usage[] = {
  17         N_("git replace [-f] <object> <replacement>"),
  18         N_("git replace -d <object>..."),
  19         N_("git replace -l [<pattern>]"),
  20         NULL
  21 };
  22
  23 static int show_reference(const char *refname, const unsigned char *sha1,
  24                           int flag, void *cb_data)
  25 {
  26         const char *pattern = cb_data;
  27
  28         if (!fnmatch(pattern, refname, 0))
  29                 printf("%s\n", refname);
  30
  31         return 0;
  32 }
  33
  34 static int list_replace_refs(const char *pattern)
  35 {
  36         if (pattern == NULL)
  37                 pattern = "*";
  38
  39         for_each_replace_ref(show_reference, (void *) pattern);
  40
  41         return 0;
  42 }
  43
  44 typedef int (*each_replace_name_fn)(const char *name, const char *ref,
  45                                     const unsigned char *sha1);
  46
  47 static int for_each_replace_name(const char **argv, each_replace_name_fn fn)
  48 {
  49         const char **p, *full_hex;
  50         char ref[PATH_MAX];
  51         int had_error = 0;
  52         unsigned char sha1[20];
  53
  54         for (p = argv; *p; p++) {
  55                 if (get_sha1(*p, sha1)) {
  56                         error("Failed to resolve '%s' as a valid ref.", *p);
  57                         had_error = 1;
  58                         continue;
  59                 }
  60                 full_hex = sha1_to_hex(sha1);
  61                 snprintf(ref, sizeof(ref), "refs/replace/%s", full_hex);
  62                 /* read_ref() may reuse the buffer */
  63                 full_hex = ref + strlen("refs/replace/");
  64                 if (read_ref(ref, sha1)) {
  65                         error("replace ref '%s' not found.", full_hex);
  66                         had_error = 1;
  67                         continue;
  68                 }
  69                 if (fn(full_hex, ref, sha1))
  70                         had_error = 1;
  71         }
  72         return had_error;
  73 }
  74
  75 static int delete_replace_ref(const char *name, const char *ref,
  76                               const unsigned char *sha1)
  77 {
  78         if (delete_ref(ref, sha1, 0))
  79                 return 1;
  80         printf("Deleted replace ref '%s'\n", name);
  81         return 0;
  82 }
  83
  84 static int replace_object(const char *object_ref, const char *replace_ref,
  85                           int force)
  86 {
  87         unsigned char object[20], prev[20], repl[20];
  88         char ref[PATH_MAX];
  89         struct ref_lock *lock;
  90
  91         if (get_sha1(object_ref, object))
  92                 die("Failed to resolve '%s' as a valid ref.", object_ref);
  93         if (get_sha1(replace_ref, repl))
  94                 die("Failed to resolve '%s' as a valid ref.", replace_ref);
  95
  96         if (snprintf(ref, sizeof(ref),
  97                      "refs/replace/%s",
  98                      sha1_to_hex(object)) > sizeof(ref) - 1)
  99                 die("replace ref name too long: %.*s...", 50, ref);
 100         if (check_refname_format(ref, 0))
 101                 die("'%s' is not a valid ref name.", ref);
 102
 103         if (read_ref(ref, prev))
 104                 hashclr(prev);
 105         else if (!force)
 106                 die("replace ref '%s' already exists", ref);
 107
 108         lock = lock_any_ref_for_update(ref, prev, 0);
 109         if (!lock)
 110                 die("%s: cannot lock the ref", ref);
 111         if (write_ref_sha1(lock, repl, NULL) < 0)
 112                 die("%s: cannot update the ref", ref);
 113
 114         return 0;
 115 }
 116
 117 int cmd_replace(int argc, const char **argv, const char *prefix)
 118 {
 119         int list = 0, delete = 0, force = 0;
 120         struct option options[] = {
 121                 OPT_BOOLEAN('l', NULL, &list, N_("list replace refs")),
 122                 OPT_BOOLEAN('d', NULL, &delete, N_("delete replace refs")),
 123                 OPT_BOOLEAN('f', NULL, &force, N_("replace the ref if it exists")),
 124                 OPT_END()
 125         };
 126
 127         argc = parse_options(argc, argv, prefix, options, git_replace_usage, 0);
 128
 129         if (list && delete)
 130                 usage_msg_opt("-l and -d cannot be used together",
 131                               git_replace_usage, options);
 132
 133         if (force && (list || delete))
 134                 usage_msg_opt("-f cannot be used with -d or -l",
 135                               git_replace_usage, options);
 136
 137         /* Delete refs */
 138         if (delete) {
 139                 if (argc < 1)
 140                         usage_msg_opt("-d needs at least one argument",
 141                                       git_replace_usage, options);
 142                 return for_each_replace_name(argv, delete_replace_ref);
 143         }
 144
 145         /* Replace object */
 146         if (!list && argc) {
 147                 if (argc != 2)
 148                         usage_msg_opt("bad number of arguments",
 149                                       git_replace_usage, options);
 150                 return replace_object(argv[0], argv[1], force);
 151         }
 152
 153         /* List refs, even if "list" is not set */
 154         if (argc > 1)
 155                 usage_msg_opt("only one pattern can be given with -l",
 156                               git_replace_usage, options);
 157         if (force)
 158                 usage_msg_opt("-f needs some arguments",
 159                               git_replace_usage, options);
 160
 161         return list_replace_refs(argv[0]);
 162 }