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         enum object_type obj_type, repl_type;
  89         char ref[PATH_MAX];
  90         struct ref_lock *lock;
  91
  92         if (get_sha1(object_ref, object))
  93                 die("Failed to resolve '%s' as a valid ref.", object_ref);
  94         if (get_sha1(replace_ref, repl))
  95                 die("Failed to resolve '%s' as a valid ref.", replace_ref);
  96
  97         if (snprintf(ref, sizeof(ref),
  98                      "refs/replace/%s",
  99                      sha1_to_hex(object)) > sizeof(ref) - 1)
 100                 die("replace ref name too long: %.*s...", 50, ref);
 101         if (check_refname_format(ref, 0))
 102                 die("'%s' is not a valid ref name.", ref);
 103
 104         obj_type = sha1_object_info(object, NULL);
 105         repl_type = sha1_object_info(repl, NULL);
 106         if (!force && obj_type != repl_type)
 107                 die("Objects must be of the same type.\n"
 108                     "'%s' points to a replaced object of type '%s'\n"
 109                     "while '%s' points to a replacement object of type '%s'.",
 110                     object_ref, typename(obj_type),
 111                     replace_ref, typename(repl_type));
 112
 113         if (read_ref(ref, prev))
 114                 hashclr(prev);
 115         else if (!force)
 116                 die("replace ref '%s' already exists", ref);
 117
 118         lock = lock_any_ref_for_update(ref, prev, 0, NULL);
 119         if (!lock)
 120                 die("%s: cannot lock the ref", ref);
 121         if (write_ref_sha1(lock, repl, NULL) < 0)
 122                 die("%s: cannot update the ref", ref);
 123
 124         return 0;
 125 }
 126
 127 int cmd_replace(int argc, const char **argv, const char *prefix)
 128 {
 129         int list = 0, delete = 0, force = 0;
 130         struct option options[] = {
 131                 OPT_BOOL('l', "list", &list, N_("list replace refs")),
 132                 OPT_BOOL('d', "delete", &delete, N_("delete replace refs")),
 133                 OPT_BOOL('f', "force", &force, N_("replace the ref if it exists")),
 134                 OPT_END()
 135         };
 136
 137         argc = parse_options(argc, argv, prefix, options, git_replace_usage, 0);
 138
 139         if (list && delete)
 140                 usage_msg_opt("-l and -d cannot be used together",
 141                               git_replace_usage, options);
 142
 143         if (force && (list || delete))
 144                 usage_msg_opt("-f cannot be used with -d or -l",
 145                               git_replace_usage, options);
 146
 147         /* Delete refs */
 148         if (delete) {
 149                 if (argc < 1)
 150                         usage_msg_opt("-d needs at least one argument",
 151                                       git_replace_usage, options);
 152                 return for_each_replace_name(argv, delete_replace_ref);
 153         }
 154
 155         /* Replace object */
 156         if (!list && argc) {
 157                 if (argc != 2)
 158                         usage_msg_opt("bad number of arguments",
 159                                       git_replace_usage, options);
 160                 return replace_object(argv[0], argv[1], force);
 161         }
 162
 163         /* List refs, even if "list" is not set */
 164         if (argc > 1)
 165                 usage_msg_opt("only one pattern can be given with -l",
 166                               git_replace_usage, options);
 167         if (force)
 168                 usage_msg_opt("-f needs some arguments",
 169                               git_replace_usage, options);
 170
 171         return list_replace_refs(argv[0]);
 172 }