git.oblomov.eu Git - git/blob - builtin/rebase.c

   1 /*
   2  * "git rebase" builtin command
   3  *
   4  * Copyright (c) 2018 Pratik Karki
   5  */
   6
   7 #include "builtin.h"
   8 #include "run-command.h"
   9 #include "exec-cmd.h"
  10 #include "argv-array.h"
  11 #include "dir.h"
  12 #include "packfile.h"
  13 #include "refs.h"
  14 #include "quote.h"
  15 #include "config.h"
  16 #include "cache-tree.h"
  17 #include "unpack-trees.h"
  18 #include "lockfile.h"
  19 #include "parse-options.h"
  20 #include "commit.h"
  21
  22 static char const * const builtin_rebase_usage[] = {
  23         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  24                 "[<upstream>] [<branch>]"),
  25         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  26                 "--root [<branch>]"),
  27         N_("git rebase --continue | --abort | --skip | --edit-todo"),
  28         NULL
  29 };
  30
  31 static GIT_PATH_FUNC(apply_dir, "rebase-apply")
  32 static GIT_PATH_FUNC(merge_dir, "rebase-merge")
  33
  34 enum rebase_type {
  35         REBASE_UNSPECIFIED = -1,
  36         REBASE_AM,
  37         REBASE_MERGE,
  38         REBASE_INTERACTIVE,
  39         REBASE_PRESERVE_MERGES
  40 };
  41
  42 static int use_builtin_rebase(void)
  43 {
  44         struct child_process cp = CHILD_PROCESS_INIT;
  45         struct strbuf out = STRBUF_INIT;
  46         int ret;
  47
  48         argv_array_pushl(&cp.args,
  49                          "config", "--bool", "rebase.usebuiltin", NULL);
  50         cp.git_cmd = 1;
  51         if (capture_command(&cp, &out, 6)) {
  52                 strbuf_release(&out);
  53                 return 0;
  54         }
  55
  56         strbuf_trim(&out);
  57         ret = !strcmp("true", out.buf);
  58         strbuf_release(&out);
  59         return ret;
  60 }
  61
  62 static int apply_autostash(void)
  63 {
  64         warning("TODO");
  65         return 0;
  66 }
  67
  68 struct rebase_options {
  69         enum rebase_type type;
  70         const char *state_dir;
  71         struct commit *upstream;
  72         const char *upstream_name;
  73         const char *upstream_arg;
  74         char *head_name;
  75         struct object_id orig_head;
  76         struct commit *onto;
  77         const char *onto_name;
  78         const char *revisions;
  79         int root;
  80         struct commit *restrict_revision;
  81         int dont_finish_rebase;
  82 };
  83
  84 /* Returns the filename prefixed by the state_dir */
  85 static const char *state_dir_path(const char *filename, struct rebase_options *opts)
  86 {
  87         static struct strbuf path = STRBUF_INIT;
  88         static size_t prefix_len;
  89
  90         if (!prefix_len) {
  91                 strbuf_addf(&path, "%s/", opts->state_dir);
  92                 prefix_len = path.len;
  93         }
  94
  95         strbuf_setlen(&path, prefix_len);
  96         strbuf_addstr(&path, filename);
  97         return path.buf;
  98 }
  99
 100 static int finish_rebase(struct rebase_options *opts)
 101 {
 102         struct strbuf dir = STRBUF_INIT;
 103         const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 104
 105         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 106         apply_autostash();
 107         close_all_packs(the_repository->objects);
 108         /*
 109          * We ignore errors in 'gc --auto', since the
 110          * user should see them.
 111          */
 112         run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 113         strbuf_addstr(&dir, opts->state_dir);
 114         remove_dir_recursively(&dir, 0);
 115         strbuf_release(&dir);
 116
 117         return 0;
 118 }
 119
 120 static struct commit *peel_committish(const char *name)
 121 {
 122         struct object *obj;
 123         struct object_id oid;
 124
 125         if (get_oid(name, &oid))
 126                 return NULL;
 127         obj = parse_object(the_repository, &oid);
 128         return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 129 }
 130
 131 static void add_var(struct strbuf *buf, const char *name, const char *value)
 132 {
 133         if (!value)
 134                 strbuf_addf(buf, "unset %s; ", name);
 135         else {
 136                 strbuf_addf(buf, "%s=", name);
 137                 sq_quote_buf(buf, value);
 138                 strbuf_addstr(buf, "; ");
 139         }
 140 }
 141
 142 static int run_specific_rebase(struct rebase_options *opts)
 143 {
 144         const char *argv[] = { NULL, NULL };
 145         struct strbuf script_snippet = STRBUF_INIT;
 146         int status;
 147         const char *backend, *backend_func;
 148
 149         add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
 150         add_var(&script_snippet, "state_dir", opts->state_dir);
 151
 152         add_var(&script_snippet, "upstream_name", opts->upstream_name);
 153         add_var(&script_snippet, "upstream",
 154                                  oid_to_hex(&opts->upstream->object.oid));
 155         add_var(&script_snippet, "head_name", opts->head_name);
 156         add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
 157         add_var(&script_snippet, "onto", oid_to_hex(&opts->onto->object.oid));
 158         add_var(&script_snippet, "onto_name", opts->onto_name);
 159         add_var(&script_snippet, "revisions", opts->revisions);
 160         add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
 161                 oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
 162
 163         switch (opts->type) {
 164         case REBASE_AM:
 165                 backend = "git-rebase--am";
 166                 backend_func = "git_rebase__am";
 167                 break;
 168         case REBASE_INTERACTIVE:
 169                 backend = "git-rebase--interactive";
 170                 backend_func = "git_rebase__interactive";
 171                 break;
 172         case REBASE_MERGE:
 173                 backend = "git-rebase--merge";
 174                 backend_func = "git_rebase__merge";
 175                 break;
 176         case REBASE_PRESERVE_MERGES:
 177                 backend = "git-rebase--preserve-merges";
 178                 backend_func = "git_rebase__preserve_merges";
 179                 break;
 180         default:
 181                 BUG("Unhandled rebase type %d", opts->type);
 182                 break;
 183         }
 184
 185         strbuf_addf(&script_snippet,
 186                     ". git-sh-setup && . git-rebase--common &&"
 187                     " . %s && %s", backend, backend_func);
 188         argv[0] = script_snippet.buf;
 189
 190         status = run_command_v_opt(argv, RUN_USING_SHELL);
 191         if (opts->dont_finish_rebase)
 192                 ; /* do nothing */
 193         else if (status == 0) {
 194                 if (!file_exists(state_dir_path("stopped-sha", opts)))
 195                         finish_rebase(opts);
 196         } else if (status == 2) {
 197                 struct strbuf dir = STRBUF_INIT;
 198
 199                 apply_autostash();
 200                 strbuf_addstr(&dir, opts->state_dir);
 201                 remove_dir_recursively(&dir, 0);
 202                 strbuf_release(&dir);
 203                 die("Nothing to do");
 204         }
 205
 206         strbuf_release(&script_snippet);
 207
 208         return status ? -1 : 0;
 209 }
 210
 211 #define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 212
 213 static int reset_head(struct object_id *oid, const char *action,
 214                       const char *switch_to_branch, int detach_head)
 215 {
 216         struct object_id head_oid;
 217         struct tree_desc desc;
 218         struct lock_file lock = LOCK_INIT;
 219         struct unpack_trees_options unpack_tree_opts;
 220         struct tree *tree;
 221         const char *reflog_action;
 222         struct strbuf msg = STRBUF_INIT;
 223         size_t prefix_len;
 224         struct object_id *orig = NULL, oid_orig,
 225                 *old_orig = NULL, oid_old_orig;
 226         int ret = 0;
 227
 228         if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0)
 229                 return -1;
 230
 231         if (!oid) {
 232                 if (get_oid("HEAD", &head_oid)) {
 233                         rollback_lock_file(&lock);
 234                         return error(_("could not determine HEAD revision"));
 235                 }
 236                 oid = &head_oid;
 237         }
 238
 239         memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 240         setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 241         unpack_tree_opts.head_idx = 1;
 242         unpack_tree_opts.src_index = the_repository->index;
 243         unpack_tree_opts.dst_index = the_repository->index;
 244         unpack_tree_opts.fn = oneway_merge;
 245         unpack_tree_opts.update = 1;
 246         unpack_tree_opts.merge = 1;
 247         if (!detach_head)
 248                 unpack_tree_opts.reset = 1;
 249
 250         if (read_index_unmerged(the_repository->index) < 0) {
 251                 rollback_lock_file(&lock);
 252                 return error(_("could not read index"));
 253         }
 254
 255         if (!fill_tree_descriptor(&desc, oid)) {
 256                 error(_("failed to find tree of %s"), oid_to_hex(oid));
 257                 rollback_lock_file(&lock);
 258                 free((void *)desc.buffer);
 259                 return -1;
 260         }
 261
 262         if (unpack_trees(1, &desc, &unpack_tree_opts)) {
 263                 rollback_lock_file(&lock);
 264                 free((void *)desc.buffer);
 265                 return -1;
 266         }
 267
 268         tree = parse_tree_indirect(oid);
 269         prime_cache_tree(the_repository->index, tree);
 270
 271         if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0)
 272                 ret = error(_("could not write index"));
 273         free((void *)desc.buffer);
 274
 275         if (ret)
 276                 return ret;
 277
 278         reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 279         strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 280         prefix_len = msg.len;
 281
 282         if (!get_oid("ORIG_HEAD", &oid_old_orig))
 283                 old_orig = &oid_old_orig;
 284         if (!get_oid("HEAD", &oid_orig)) {
 285                 orig = &oid_orig;
 286                 strbuf_addstr(&msg, "updating ORIG_HEAD");
 287                 update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0,
 288                            UPDATE_REFS_MSG_ON_ERR);
 289         } else if (old_orig)
 290                 delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 291         strbuf_setlen(&msg, prefix_len);
 292         strbuf_addstr(&msg, "updating HEAD");
 293         if (!switch_to_branch)
 294                 ret = update_ref(msg.buf, "HEAD", oid, orig, REF_NO_DEREF,
 295                                  UPDATE_REFS_MSG_ON_ERR);
 296         else {
 297                 ret = create_symref("HEAD", switch_to_branch, msg.buf);
 298                 if (!ret)
 299                         ret = update_ref(msg.buf, "HEAD", oid, NULL, 0,
 300                                          UPDATE_REFS_MSG_ON_ERR);
 301         }
 302
 303         strbuf_release(&msg);
 304         return ret;
 305 }
 306
 307 int cmd_rebase(int argc, const char **argv, const char *prefix)
 308 {
 309         struct rebase_options options = {
 310                 .type = REBASE_UNSPECIFIED,
 311         };
 312         const char *branch_name;
 313         int ret, flags;
 314         int ok_to_skip_pre_rebase = 0;
 315         struct strbuf msg = STRBUF_INIT;
 316         struct strbuf revisions = STRBUF_INIT;
 317         struct object_id merge_base;
 318         struct option builtin_rebase_options[] = {
 319                 OPT_STRING(0, "onto", &options.onto_name,
 320                            N_("revision"),
 321                            N_("rebase onto given branch instead of upstream")),
 322                 OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
 323                          N_("allow pre-rebase hook to run")),
 324                 OPT_END(),
 325         };
 326
 327         /*
 328          * NEEDSWORK: Once the builtin rebase has been tested enough
 329          * and git-legacy-rebase.sh is retired to contrib/, this preamble
 330          * can be removed.
 331          */
 332
 333         if (!use_builtin_rebase()) {
 334                 const char *path = mkpath("%s/git-legacy-rebase",
 335                                           git_exec_path());
 336
 337                 if (sane_execvp(path, (char **)argv) < 0)
 338                         die_errno(_("could not exec %s"), path);
 339                 else
 340                         BUG("sane_execvp() returned???");
 341         }
 342
 343         if (argc == 2 && !strcmp(argv[1], "-h"))
 344                 usage_with_options(builtin_rebase_usage,
 345                                    builtin_rebase_options);
 346
 347         prefix = setup_git_directory();
 348         trace_repo_setup(prefix);
 349         setup_work_tree();
 350
 351         git_config(git_default_config, NULL);
 352         argc = parse_options(argc, argv, prefix,
 353                              builtin_rebase_options,
 354                              builtin_rebase_usage, 0);
 355
 356         if (argc > 2)
 357                 usage_with_options(builtin_rebase_usage,
 358                                    builtin_rebase_options);
 359
 360         switch (options.type) {
 361         case REBASE_MERGE:
 362         case REBASE_INTERACTIVE:
 363         case REBASE_PRESERVE_MERGES:
 364                 options.state_dir = merge_dir();
 365                 break;
 366         case REBASE_AM:
 367                 options.state_dir = apply_dir();
 368                 break;
 369         default:
 370                 /* the default rebase backend is `--am` */
 371                 options.type = REBASE_AM;
 372                 options.state_dir = apply_dir();
 373                 break;
 374         }
 375
 376         if (!options.root) {
 377                 if (argc < 1)
 378                         die("TODO: handle @{upstream}");
 379                 else {
 380                         options.upstream_name = argv[0];
 381                         argc--;
 382                         argv++;
 383                         if (!strcmp(options.upstream_name, "-"))
 384                                 options.upstream_name = "@{-1}";
 385                 }
 386                 options.upstream = peel_committish(options.upstream_name);
 387                 if (!options.upstream)
 388                         die(_("invalid upstream '%s'"), options.upstream_name);
 389                 options.upstream_arg = options.upstream_name;
 390         } else
 391                 die("TODO: upstream for --root");
 392
 393         /* Make sure the branch to rebase onto is valid. */
 394         if (!options.onto_name)
 395                 options.onto_name = options.upstream_name;
 396         if (strstr(options.onto_name, "...")) {
 397                 if (get_oid_mb(options.onto_name, &merge_base) < 0)
 398                         die(_("'%s': need exactly one merge base"),
 399                             options.onto_name);
 400                 options.onto = lookup_commit_or_die(&merge_base,
 401                                                     options.onto_name);
 402         } else {
 403                 options.onto = peel_committish(options.onto_name);
 404                 if (!options.onto)
 405                         die(_("Does not point to a valid commit '%s'"),
 406                                 options.onto_name);
 407         }
 408
 409         /*
 410          * If the branch to rebase is given, that is the branch we will rebase
 411          * branch_name -- branch/commit being rebased, or
 412          *                HEAD (already detached)
 413          * orig_head -- commit object name of tip of the branch before rebasing
 414          * head_name -- refs/heads/<that-branch> or "detached HEAD"
 415          */
 416         if (argc > 0)
 417                  die("TODO: handle switch_to");
 418         else {
 419                 /* Do not need to switch branches, we are already on it. */
 420                 options.head_name =
 421                         xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
 422                                          &flags));
 423                 if (!options.head_name)
 424                         die(_("No such ref: %s"), "HEAD");
 425                 if (flags & REF_ISSYMREF) {
 426                         if (!skip_prefix(options.head_name,
 427                                          "refs/heads/", &branch_name))
 428                                 branch_name = options.head_name;
 429
 430                 } else {
 431                         options.head_name = xstrdup("detached HEAD");
 432                         branch_name = "HEAD";
 433                 }
 434                 if (get_oid("HEAD", &options.orig_head))
 435                         die(_("Could not resolve HEAD to a revision"));
 436         }
 437
 438         /* If a hook exists, give it a chance to interrupt*/
 439         if (!ok_to_skip_pre_rebase &&
 440             run_hook_le(NULL, "pre-rebase", options.upstream_arg,
 441                         argc ? argv[0] : NULL, NULL))
 442                 die(_("The pre-rebase hook refused to rebase."));
 443
 444         strbuf_addf(&msg, "rebase: checkout %s", options.onto_name);
 445         if (reset_head(&options.onto->object.oid, "checkout", NULL, 1))
 446                 die(_("Could not detach HEAD"));
 447         strbuf_release(&msg);
 448
 449         strbuf_addf(&revisions, "%s..%s",
 450                     options.root ? oid_to_hex(&options.onto->object.oid) :
 451                     (options.restrict_revision ?
 452                      oid_to_hex(&options.restrict_revision->object.oid) :
 453                      oid_to_hex(&options.upstream->object.oid)),
 454                     oid_to_hex(&options.orig_head));
 455
 456         options.revisions = revisions.buf;
 457
 458         ret = !!run_specific_rebase(&options);
 459
 460         strbuf_release(&revisions);
 461         free(options.head_name);
 462         return ret;
 463 }