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         "git replace [-f] <object> <replacement>",
  18         "git replace -d <object>...",
  19         "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;
  50         char ref[PATH_MAX];
  51         int had_error = 0;
  52         unsigned char sha1[20];
  53
  54         for (p = argv; *p; p++) {
  55                 if (snprintf(ref, sizeof(ref), "refs/replace/%s", *p)
  56                                         >= sizeof(ref)) {
  57                         error("replace ref name too long: %.*s...", 50, *p);
  58                         had_error = 1;
  59                         continue;
  60                 }
  61                 if (!resolve_ref(ref, sha1, 1, NULL)) {
  62                         error("replace ref '%s' not found.", *p);
  63                         had_error = 1;
  64                         continue;
  65                 }
  66                 if (fn(*p, ref, sha1))
  67                         had_error = 1;
  68         }
  69         return had_error;
  70 }
  71
  72 static int delete_replace_ref(const char *name, const char *ref,
  73                               const unsigned char *sha1)
  74 {
  75         if (delete_ref(ref, sha1, 0))
  76                 return 1;
  77         printf("Deleted replace ref '%s'\n", name);
  78         return 0;
  79 }
  80
  81 static int replace_object(const char *object_ref, const char *replace_ref,
  82                           int force)
  83 {
  84         unsigned char object[20], prev[20], repl[20];
  85         char ref[PATH_MAX];
  86         struct ref_lock *lock;
  87
  88         if (get_sha1(object_ref, object))
  89                 die("Failed to resolve '%s' as a valid ref.", object_ref);
  90         if (get_sha1(replace_ref, repl))
  91                 die("Failed to resolve '%s' as a valid ref.", replace_ref);
  92
  93         if (snprintf(ref, sizeof(ref),
  94                      "refs/replace/%s",
  95                      sha1_to_hex(object)) > sizeof(ref) - 1)
  96                 die("replace ref name too long: %.*s...", 50, ref);
  97         if (check_ref_format(ref))
  98                 die("'%s' is not a valid ref name.", ref);
  99
 100         if (!resolve_ref(ref, prev, 1, NULL))
 101                 hashclr(prev);
 102         else if (!force)
 103                 die("replace ref '%s' already exists", ref);
 104
 105         lock = lock_any_ref_for_update(ref, prev, 0);
 106         if (!lock)
 107                 die("%s: cannot lock the ref", ref);
 108         if (write_ref_sha1(lock, repl, NULL) < 0)
 109                 die("%s: cannot update the ref", ref);
 110
 111         return 0;
 112 }
 113
 114 int cmd_replace(int argc, const char **argv, const char *prefix)
 115 {
 116         int list = 0, delete = 0, force = 0;
 117         struct option options[] = {
 118                 OPT_BOOLEAN('l', NULL, &list, "list replace refs"),
 119                 OPT_BOOLEAN('d', NULL, &delete, "delete replace refs"),
 120                 OPT_BOOLEAN('f', NULL, &force, "replace the ref if it exists"),
 121                 OPT_END()
 122         };
 123
 124         argc = parse_options(argc, argv, prefix, options, git_replace_usage, 0);
 125
 126         if (list && delete)
 127                 usage_msg_opt("-l and -d cannot be used together",
 128                               git_replace_usage, options);
 129
 130         if (force && (list || delete))
 131                 usage_msg_opt("-f cannot be used with -d or -l",
 132                               git_replace_usage, options);
 133
 134         /* Delete refs */
 135         if (delete) {
 136                 if (argc < 1)
 137                         usage_msg_opt("-d needs at least one argument",
 138                                       git_replace_usage, options);
 139                 return for_each_replace_name(argv, delete_replace_ref);
 140         }
 141
 142         /* Replace object */
 143         if (!list && argc) {
 144                 if (argc != 2)
 145                         usage_msg_opt("bad number of arguments",
 146                                       git_replace_usage, options);
 147                 return replace_object(argv[0], argv[1], force);
 148         }
 149
 150         /* List refs, even if "list" is not set */
 151         if (argc > 1)
 152                 usage_msg_opt("only one pattern can be given with -l",
 153                               git_replace_usage, options);
 154         if (force)
 155                 usage_msg_opt("-f needs some arguments",
 156                               git_replace_usage, options);
 157
 158         return list_replace_refs(argv[0]);
 159 }