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         enum {
  83                 REBASE_NO_QUIET = 1<<0,
  84         } flags;
  85         struct strbuf git_am_opt;
  86 };
  87
  88 /* Returns the filename prefixed by the state_dir */
  89 static const char *state_dir_path(const char *filename, struct rebase_options *opts)
  90 {
  91         static struct strbuf path = STRBUF_INIT;
  92         static size_t prefix_len;
  93
  94         if (!prefix_len) {
  95                 strbuf_addf(&path, "%s/", opts->state_dir);
  96                 prefix_len = path.len;
  97         }
  98
  99         strbuf_setlen(&path, prefix_len);
 100         strbuf_addstr(&path, filename);
 101         return path.buf;
 102 }
 103
 104 static int finish_rebase(struct rebase_options *opts)
 105 {
 106         struct strbuf dir = STRBUF_INIT;
 107         const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 108
 109         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 110         apply_autostash();
 111         close_all_packs(the_repository->objects);
 112         /*
 113          * We ignore errors in 'gc --auto', since the
 114          * user should see them.
 115          */
 116         run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 117         strbuf_addstr(&dir, opts->state_dir);
 118         remove_dir_recursively(&dir, 0);
 119         strbuf_release(&dir);
 120
 121         return 0;
 122 }
 123
 124 static struct commit *peel_committish(const char *name)
 125 {
 126         struct object *obj;
 127         struct object_id oid;
 128
 129         if (get_oid(name, &oid))
 130                 return NULL;
 131         obj = parse_object(the_repository, &oid);
 132         return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 133 }
 134
 135 static void add_var(struct strbuf *buf, const char *name, const char *value)
 136 {
 137         if (!value)
 138                 strbuf_addf(buf, "unset %s; ", name);
 139         else {
 140                 strbuf_addf(buf, "%s=", name);
 141                 sq_quote_buf(buf, value);
 142                 strbuf_addstr(buf, "; ");
 143         }
 144 }
 145
 146 static int run_specific_rebase(struct rebase_options *opts)
 147 {
 148         const char *argv[] = { NULL, NULL };
 149         struct strbuf script_snippet = STRBUF_INIT;
 150         int status;
 151         const char *backend, *backend_func;
 152
 153         add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
 154         add_var(&script_snippet, "state_dir", opts->state_dir);
 155
 156         add_var(&script_snippet, "upstream_name", opts->upstream_name);
 157         add_var(&script_snippet, "upstream",
 158                                  oid_to_hex(&opts->upstream->object.oid));
 159         add_var(&script_snippet, "head_name", opts->head_name);
 160         add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
 161         add_var(&script_snippet, "onto", oid_to_hex(&opts->onto->object.oid));
 162         add_var(&script_snippet, "onto_name", opts->onto_name);
 163         add_var(&script_snippet, "revisions", opts->revisions);
 164         add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
 165                 oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
 166         add_var(&script_snippet, "GIT_QUIET",
 167                 opts->flags & REBASE_NO_QUIET ? "" : "t");
 168         add_var(&script_snippet, "git_am_opt", opts->git_am_opt.buf);
 169
 170         switch (opts->type) {
 171         case REBASE_AM:
 172                 backend = "git-rebase--am";
 173                 backend_func = "git_rebase__am";
 174                 break;
 175         case REBASE_INTERACTIVE:
 176                 backend = "git-rebase--interactive";
 177                 backend_func = "git_rebase__interactive";
 178                 break;
 179         case REBASE_MERGE:
 180                 backend = "git-rebase--merge";
 181                 backend_func = "git_rebase__merge";
 182                 break;
 183         case REBASE_PRESERVE_MERGES:
 184                 backend = "git-rebase--preserve-merges";
 185                 backend_func = "git_rebase__preserve_merges";
 186                 break;
 187         default:
 188                 BUG("Unhandled rebase type %d", opts->type);
 189                 break;
 190         }
 191
 192         strbuf_addf(&script_snippet,
 193                     ". git-sh-setup && . git-rebase--common &&"
 194                     " . %s && %s", backend, backend_func);
 195         argv[0] = script_snippet.buf;
 196
 197         status = run_command_v_opt(argv, RUN_USING_SHELL);
 198         if (opts->dont_finish_rebase)
 199                 ; /* do nothing */
 200         else if (status == 0) {
 201                 if (!file_exists(state_dir_path("stopped-sha", opts)))
 202                         finish_rebase(opts);
 203         } else if (status == 2) {
 204                 struct strbuf dir = STRBUF_INIT;
 205
 206                 apply_autostash();
 207                 strbuf_addstr(&dir, opts->state_dir);
 208                 remove_dir_recursively(&dir, 0);
 209                 strbuf_release(&dir);
 210                 die("Nothing to do");
 211         }
 212
 213         strbuf_release(&script_snippet);
 214
 215         return status ? -1 : 0;
 216 }
 217
 218 #define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 219
 220 static int reset_head(struct object_id *oid, const char *action,
 221                       const char *switch_to_branch, int detach_head)
 222 {
 223         struct object_id head_oid;
 224         struct tree_desc desc;
 225         struct lock_file lock = LOCK_INIT;
 226         struct unpack_trees_options unpack_tree_opts;
 227         struct tree *tree;
 228         const char *reflog_action;
 229         struct strbuf msg = STRBUF_INIT;
 230         size_t prefix_len;
 231         struct object_id *orig = NULL, oid_orig,
 232                 *old_orig = NULL, oid_old_orig;
 233         int ret = 0;
 234
 235         if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0)
 236                 return -1;
 237
 238         if (!oid) {
 239                 if (get_oid("HEAD", &head_oid)) {
 240                         rollback_lock_file(&lock);
 241                         return error(_("could not determine HEAD revision"));
 242                 }
 243                 oid = &head_oid;
 244         }
 245
 246         memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 247         setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 248         unpack_tree_opts.head_idx = 1;
 249         unpack_tree_opts.src_index = the_repository->index;
 250         unpack_tree_opts.dst_index = the_repository->index;
 251         unpack_tree_opts.fn = oneway_merge;
 252         unpack_tree_opts.update = 1;
 253         unpack_tree_opts.merge = 1;
 254         if (!detach_head)
 255                 unpack_tree_opts.reset = 1;
 256
 257         if (read_index_unmerged(the_repository->index) < 0) {
 258                 rollback_lock_file(&lock);
 259                 return error(_("could not read index"));
 260         }
 261
 262         if (!fill_tree_descriptor(&desc, oid)) {
 263                 error(_("failed to find tree of %s"), oid_to_hex(oid));
 264                 rollback_lock_file(&lock);
 265                 free((void *)desc.buffer);
 266                 return -1;
 267         }
 268
 269         if (unpack_trees(1, &desc, &unpack_tree_opts)) {
 270                 rollback_lock_file(&lock);
 271                 free((void *)desc.buffer);
 272                 return -1;
 273         }
 274
 275         tree = parse_tree_indirect(oid);
 276         prime_cache_tree(the_repository->index, tree);
 277
 278         if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0)
 279                 ret = error(_("could not write index"));
 280         free((void *)desc.buffer);
 281
 282         if (ret)
 283                 return ret;
 284
 285         reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 286         strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 287         prefix_len = msg.len;
 288
 289         if (!get_oid("ORIG_HEAD", &oid_old_orig))
 290                 old_orig = &oid_old_orig;
 291         if (!get_oid("HEAD", &oid_orig)) {
 292                 orig = &oid_orig;
 293                 strbuf_addstr(&msg, "updating ORIG_HEAD");
 294                 update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0,
 295                            UPDATE_REFS_MSG_ON_ERR);
 296         } else if (old_orig)
 297                 delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 298         strbuf_setlen(&msg, prefix_len);
 299         strbuf_addstr(&msg, "updating HEAD");
 300         if (!switch_to_branch)
 301                 ret = update_ref(msg.buf, "HEAD", oid, orig, REF_NO_DEREF,
 302                                  UPDATE_REFS_MSG_ON_ERR);
 303         else {
 304                 ret = create_symref("HEAD", switch_to_branch, msg.buf);
 305                 if (!ret)
 306                         ret = update_ref(msg.buf, "HEAD", oid, NULL, 0,
 307                                          UPDATE_REFS_MSG_ON_ERR);
 308         }
 309
 310         strbuf_release(&msg);
 311         return ret;
 312 }
 313
 314 int cmd_rebase(int argc, const char **argv, const char *prefix)
 315 {
 316         struct rebase_options options = {
 317                 .type = REBASE_UNSPECIFIED,
 318                 .flags = REBASE_NO_QUIET,
 319                 .git_am_opt = STRBUF_INIT,
 320         };
 321         const char *branch_name;
 322         int ret, flags;
 323         int ok_to_skip_pre_rebase = 0;
 324         struct strbuf msg = STRBUF_INIT;
 325         struct strbuf revisions = STRBUF_INIT;
 326         struct object_id merge_base;
 327         struct option builtin_rebase_options[] = {
 328                 OPT_STRING(0, "onto", &options.onto_name,
 329                            N_("revision"),
 330                            N_("rebase onto given branch instead of upstream")),
 331                 OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
 332                          N_("allow pre-rebase hook to run")),
 333                 OPT_NEGBIT('q', "quiet", &options.flags,
 334                            N_("be quiet. implies --no-stat"),
 335                            REBASE_NO_QUIET),
 336                 OPT_END(),
 337         };
 338
 339         /*
 340          * NEEDSWORK: Once the builtin rebase has been tested enough
 341          * and git-legacy-rebase.sh is retired to contrib/, this preamble
 342          * can be removed.
 343          */
 344
 345         if (!use_builtin_rebase()) {
 346                 const char *path = mkpath("%s/git-legacy-rebase",
 347                                           git_exec_path());
 348
 349                 if (sane_execvp(path, (char **)argv) < 0)
 350                         die_errno(_("could not exec %s"), path);
 351                 else
 352                         BUG("sane_execvp() returned???");
 353         }
 354
 355         if (argc == 2 && !strcmp(argv[1], "-h"))
 356                 usage_with_options(builtin_rebase_usage,
 357                                    builtin_rebase_options);
 358
 359         prefix = setup_git_directory();
 360         trace_repo_setup(prefix);
 361         setup_work_tree();
 362
 363         git_config(git_default_config, NULL);
 364         argc = parse_options(argc, argv, prefix,
 365                              builtin_rebase_options,
 366                              builtin_rebase_usage, 0);
 367
 368         if (argc > 2)
 369                 usage_with_options(builtin_rebase_usage,
 370                                    builtin_rebase_options);
 371
 372         if (!(options.flags & REBASE_NO_QUIET))
 373                 strbuf_addstr(&options.git_am_opt, " -q");
 374
 375         switch (options.type) {
 376         case REBASE_MERGE:
 377         case REBASE_INTERACTIVE:
 378         case REBASE_PRESERVE_MERGES:
 379                 options.state_dir = merge_dir();
 380                 break;
 381         case REBASE_AM:
 382                 options.state_dir = apply_dir();
 383                 break;
 384         default:
 385                 /* the default rebase backend is `--am` */
 386                 options.type = REBASE_AM;
 387                 options.state_dir = apply_dir();
 388                 break;
 389         }
 390
 391         if (!options.root) {
 392                 if (argc < 1)
 393                         die("TODO: handle @{upstream}");
 394                 else {
 395                         options.upstream_name = argv[0];
 396                         argc--;
 397                         argv++;
 398                         if (!strcmp(options.upstream_name, "-"))
 399                                 options.upstream_name = "@{-1}";
 400                 }
 401                 options.upstream = peel_committish(options.upstream_name);
 402                 if (!options.upstream)
 403                         die(_("invalid upstream '%s'"), options.upstream_name);
 404                 options.upstream_arg = options.upstream_name;
 405         } else
 406                 die("TODO: upstream for --root");
 407
 408         /* Make sure the branch to rebase onto is valid. */
 409         if (!options.onto_name)
 410                 options.onto_name = options.upstream_name;
 411         if (strstr(options.onto_name, "...")) {
 412                 if (get_oid_mb(options.onto_name, &merge_base) < 0)
 413                         die(_("'%s': need exactly one merge base"),
 414                             options.onto_name);
 415                 options.onto = lookup_commit_or_die(&merge_base,
 416                                                     options.onto_name);
 417         } else {
 418                 options.onto = peel_committish(options.onto_name);
 419                 if (!options.onto)
 420                         die(_("Does not point to a valid commit '%s'"),
 421                                 options.onto_name);
 422         }
 423
 424         /*
 425          * If the branch to rebase is given, that is the branch we will rebase
 426          * branch_name -- branch/commit being rebased, or
 427          *                HEAD (already detached)
 428          * orig_head -- commit object name of tip of the branch before rebasing
 429          * head_name -- refs/heads/<that-branch> or "detached HEAD"
 430          */
 431         if (argc > 0)
 432                  die("TODO: handle switch_to");
 433         else {
 434                 /* Do not need to switch branches, we are already on it. */
 435                 options.head_name =
 436                         xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
 437                                          &flags));
 438                 if (!options.head_name)
 439                         die(_("No such ref: %s"), "HEAD");
 440                 if (flags & REF_ISSYMREF) {
 441                         if (!skip_prefix(options.head_name,
 442                                          "refs/heads/", &branch_name))
 443                                 branch_name = options.head_name;
 444
 445                 } else {
 446                         options.head_name = xstrdup("detached HEAD");
 447                         branch_name = "HEAD";
 448                 }
 449                 if (get_oid("HEAD", &options.orig_head))
 450                         die(_("Could not resolve HEAD to a revision"));
 451         }
 452
 453         /* If a hook exists, give it a chance to interrupt*/
 454         if (!ok_to_skip_pre_rebase &&
 455             run_hook_le(NULL, "pre-rebase", options.upstream_arg,
 456                         argc ? argv[0] : NULL, NULL))
 457                 die(_("The pre-rebase hook refused to rebase."));
 458
 459         strbuf_addf(&msg, "rebase: checkout %s", options.onto_name);
 460         if (reset_head(&options.onto->object.oid, "checkout", NULL, 1))
 461                 die(_("Could not detach HEAD"));
 462         strbuf_release(&msg);
 463
 464         strbuf_addf(&revisions, "%s..%s",
 465                     options.root ? oid_to_hex(&options.onto->object.oid) :
 466                     (options.restrict_revision ?
 467                      oid_to_hex(&options.restrict_revision->object.oid) :
 468                      oid_to_hex(&options.upstream->object.oid)),
 469                     oid_to_hex(&options.orig_head));
 470
 471         options.revisions = revisions.buf;
 472
 473         ret = !!run_specific_rebase(&options);
 474
 475         strbuf_release(&revisions);
 476         free(options.head_name);
 477         return ret;
 478 }