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 [--format=<format>] [-l [<pattern>]]"),
  20         NULL
  21 };
  22
  23 enum replace_format {
  24       REPLACE_FORMAT_SHORT,
  25       REPLACE_FORMAT_MEDIUM,
  26       REPLACE_FORMAT_LONG
  27 };
  28
  29 struct show_data {
  30         const char *pattern;
  31         enum replace_format format;
  32 };
  33
  34 static int show_reference(const char *refname, const unsigned char *sha1,
  35                           int flag, void *cb_data)
  36 {
  37         struct show_data *data = cb_data;
  38
  39         if (!fnmatch(data->pattern, refname, 0)) {
  40                 if (data->format == REPLACE_FORMAT_SHORT)
  41                         printf("%s\n", refname);
  42                 else if (data->format == REPLACE_FORMAT_MEDIUM)
  43                         printf("%s -> %s\n", refname, sha1_to_hex(sha1));
  44                 else { /* data->format == REPLACE_FORMAT_LONG */
  45                         unsigned char object[20];
  46                         enum object_type obj_type, repl_type;
  47
  48                         if (get_sha1(refname, object))
  49                                 return error("Failed to resolve '%s' as a valid ref.", refname);
  50
  51                         obj_type = sha1_object_info(object, NULL);
  52                         repl_type = sha1_object_info(sha1, NULL);
  53
  54                         printf("%s (%s) -> %s (%s)\n", refname, typename(obj_type),
  55                                sha1_to_hex(sha1), typename(repl_type));
  56                 }
  57         }
  58
  59         return 0;
  60 }
  61
  62 static int list_replace_refs(const char *pattern, const char *format)
  63 {
  64         struct show_data data;
  65
  66         if (pattern == NULL)
  67                 pattern = "*";
  68         data.pattern = pattern;
  69
  70         if (format == NULL || *format == '\0' || !strcmp(format, "short"))
  71                 data.format = REPLACE_FORMAT_SHORT;
  72         else if (!strcmp(format, "medium"))
  73                 data.format = REPLACE_FORMAT_MEDIUM;
  74         else if (!strcmp(format, "long"))
  75                 data.format = REPLACE_FORMAT_LONG;
  76         else
  77                 die("invalid replace format '%s'\n"
  78                     "valid formats are 'short', 'medium' and 'long'\n",
  79                     format);
  80
  81         for_each_replace_ref(show_reference, (void *) &data);
  82
  83         return 0;
  84 }
  85
  86 typedef int (*each_replace_name_fn)(const char *name, const char *ref,
  87                                     const unsigned char *sha1);
  88
  89 static int for_each_replace_name(const char **argv, each_replace_name_fn fn)
  90 {
  91         const char **p, *full_hex;
  92         char ref[PATH_MAX];
  93         int had_error = 0;
  94         unsigned char sha1[20];
  95
  96         for (p = argv; *p; p++) {
  97                 if (get_sha1(*p, sha1)) {
  98                         error("Failed to resolve '%s' as a valid ref.", *p);
  99                         had_error = 1;
 100                         continue;
 101                 }
 102                 full_hex = sha1_to_hex(sha1);
 103                 snprintf(ref, sizeof(ref), "refs/replace/%s", full_hex);
 104                 /* read_ref() may reuse the buffer */
 105                 full_hex = ref + strlen("refs/replace/");
 106                 if (read_ref(ref, sha1)) {
 107                         error("replace ref '%s' not found.", full_hex);
 108                         had_error = 1;
 109                         continue;
 110                 }
 111                 if (fn(full_hex, ref, sha1))
 112                         had_error = 1;
 113         }
 114         return had_error;
 115 }
 116
 117 static int delete_replace_ref(const char *name, const char *ref,
 118                               const unsigned char *sha1)
 119 {
 120         if (delete_ref(ref, sha1, 0))
 121                 return 1;
 122         printf("Deleted replace ref '%s'\n", name);
 123         return 0;
 124 }
 125
 126 static int replace_object(const char *object_ref, const char *replace_ref,
 127                           int force)
 128 {
 129         unsigned char object[20], prev[20], repl[20];
 130         enum object_type obj_type, repl_type;
 131         char ref[PATH_MAX];
 132         struct ref_lock *lock;
 133
 134         if (get_sha1(object_ref, object))
 135                 die("Failed to resolve '%s' as a valid ref.", object_ref);
 136         if (get_sha1(replace_ref, repl))
 137                 die("Failed to resolve '%s' as a valid ref.", replace_ref);
 138
 139         if (snprintf(ref, sizeof(ref),
 140                      "refs/replace/%s",
 141                      sha1_to_hex(object)) > sizeof(ref) - 1)
 142                 die("replace ref name too long: %.*s...", 50, ref);
 143         if (check_refname_format(ref, 0))
 144                 die("'%s' is not a valid ref name.", ref);
 145
 146         obj_type = sha1_object_info(object, NULL);
 147         repl_type = sha1_object_info(repl, NULL);
 148         if (!force && obj_type != repl_type)
 149                 die("Objects must be of the same type.\n"
 150                     "'%s' points to a replaced object of type '%s'\n"
 151                     "while '%s' points to a replacement object of type '%s'.",
 152                     object_ref, typename(obj_type),
 153                     replace_ref, typename(repl_type));
 154
 155         if (read_ref(ref, prev))
 156                 hashclr(prev);
 157         else if (!force)
 158                 die("replace ref '%s' already exists", ref);
 159
 160         lock = lock_any_ref_for_update(ref, prev, 0, NULL);
 161         if (!lock)
 162                 die("%s: cannot lock the ref", ref);
 163         if (write_ref_sha1(lock, repl, NULL) < 0)
 164                 die("%s: cannot update the ref", ref);
 165
 166         return 0;
 167 }
 168
 169 int cmd_replace(int argc, const char **argv, const char *prefix)
 170 {
 171         int list = 0, delete = 0, force = 0;
 172         const char *format = NULL;
 173         struct option options[] = {
 174                 OPT_BOOL('l', "list", &list, N_("list replace refs")),
 175                 OPT_BOOL('d', "delete", &delete, N_("delete replace refs")),
 176                 OPT_BOOL('f', "force", &force, N_("replace the ref if it exists")),
 177                 OPT_STRING(0, "format", &format, N_("format"), N_("use this format")),
 178                 OPT_END()
 179         };
 180
 181         read_replace_refs = 0;
 182
 183         argc = parse_options(argc, argv, prefix, options, git_replace_usage, 0);
 184
 185         if (list && delete)
 186                 usage_msg_opt("-l and -d cannot be used together",
 187                               git_replace_usage, options);
 188
 189         if (format && delete)
 190                 usage_msg_opt("--format and -d cannot be used together",
 191                               git_replace_usage, options);
 192
 193         if (force && (list || delete))
 194                 usage_msg_opt("-f cannot be used with -d or -l",
 195                               git_replace_usage, options);
 196
 197         /* Delete refs */
 198         if (delete) {
 199                 if (argc < 1)
 200                         usage_msg_opt("-d needs at least one argument",
 201                                       git_replace_usage, options);
 202                 return for_each_replace_name(argv, delete_replace_ref);
 203         }
 204
 205         /* Replace object */
 206         if (!list && argc) {
 207                 if (argc != 2)
 208                         usage_msg_opt("bad number of arguments",
 209                                       git_replace_usage, options);
 210                 if (format)
 211                         usage_msg_opt("--format cannot be used when not listing",
 212                                       git_replace_usage, options);
 213                 return replace_object(argv[0], argv[1], force);
 214         }
 215
 216         /* List refs, even if "list" is not set */
 217         if (argc > 1)
 218                 usage_msg_opt("only one pattern can be given with -l",
 219                               git_replace_usage, options);
 220         if (force)
 221                 usage_msg_opt("-f needs some arguments",
 222                               git_replace_usage, options);
 223
 224         return list_replace_refs(argv[0], format);
 225 }