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