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 #include "diff.h"
  22 #include "wt-status.h"
  23
  24 static char const * const builtin_rebase_usage[] = {
  25         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  26                 "[<upstream>] [<branch>]"),
  27         N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  28                 "--root [<branch>]"),
  29         N_("git rebase --continue | --abort | --skip | --edit-todo"),
  30         NULL
  31 };
  32
  33 static GIT_PATH_FUNC(apply_dir, "rebase-apply")
  34 static GIT_PATH_FUNC(merge_dir, "rebase-merge")
  35
  36 enum rebase_type {
  37         REBASE_UNSPECIFIED = -1,
  38         REBASE_AM,
  39         REBASE_MERGE,
  40         REBASE_INTERACTIVE,
  41         REBASE_PRESERVE_MERGES
  42 };
  43
  44 static int use_builtin_rebase(void)
  45 {
  46         struct child_process cp = CHILD_PROCESS_INIT;
  47         struct strbuf out = STRBUF_INIT;
  48         int ret;
  49
  50         argv_array_pushl(&cp.args,
  51                          "config", "--bool", "rebase.usebuiltin", NULL);
  52         cp.git_cmd = 1;
  53         if (capture_command(&cp, &out, 6)) {
  54                 strbuf_release(&out);
  55                 return 0;
  56         }
  57
  58         strbuf_trim(&out);
  59         ret = !strcmp("true", out.buf);
  60         strbuf_release(&out);
  61         return ret;
  62 }
  63
  64 static int apply_autostash(void)
  65 {
  66         warning("TODO");
  67         return 0;
  68 }
  69
  70 struct rebase_options {
  71         enum rebase_type type;
  72         const char *state_dir;
  73         struct commit *upstream;
  74         const char *upstream_name;
  75         const char *upstream_arg;
  76         char *head_name;
  77         struct object_id orig_head;
  78         struct commit *onto;
  79         const char *onto_name;
  80         const char *revisions;
  81         int root;
  82         struct commit *restrict_revision;
  83         int dont_finish_rebase;
  84         enum {
  85                 REBASE_NO_QUIET = 1<<0,
  86                 REBASE_VERBOSE = 1<<1,
  87                 REBASE_DIFFSTAT = 1<<2,
  88         } flags;
  89         struct strbuf git_am_opt;
  90 };
  91
  92 /* Returns the filename prefixed by the state_dir */
  93 static const char *state_dir_path(const char *filename, struct rebase_options *opts)
  94 {
  95         static struct strbuf path = STRBUF_INIT;
  96         static size_t prefix_len;
  97
  98         if (!prefix_len) {
  99                 strbuf_addf(&path, "%s/", opts->state_dir);
 100                 prefix_len = path.len;
 101         }
 102
 103         strbuf_setlen(&path, prefix_len);
 104         strbuf_addstr(&path, filename);
 105         return path.buf;
 106 }
 107
 108 static int finish_rebase(struct rebase_options *opts)
 109 {
 110         struct strbuf dir = STRBUF_INIT;
 111         const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 112
 113         delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 114         apply_autostash();
 115         close_all_packs(the_repository->objects);
 116         /*
 117          * We ignore errors in 'gc --auto', since the
 118          * user should see them.
 119          */
 120         run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 121         strbuf_addstr(&dir, opts->state_dir);
 122         remove_dir_recursively(&dir, 0);
 123         strbuf_release(&dir);
 124
 125         return 0;
 126 }
 127
 128 static struct commit *peel_committish(const char *name)
 129 {
 130         struct object *obj;
 131         struct object_id oid;
 132
 133         if (get_oid(name, &oid))
 134                 return NULL;
 135         obj = parse_object(the_repository, &oid);
 136         return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 137 }
 138
 139 static void add_var(struct strbuf *buf, const char *name, const char *value)
 140 {
 141         if (!value)
 142                 strbuf_addf(buf, "unset %s; ", name);
 143         else {
 144                 strbuf_addf(buf, "%s=", name);
 145                 sq_quote_buf(buf, value);
 146                 strbuf_addstr(buf, "; ");
 147         }
 148 }
 149
 150 static int run_specific_rebase(struct rebase_options *opts)
 151 {
 152         const char *argv[] = { NULL, NULL };
 153         struct strbuf script_snippet = STRBUF_INIT;
 154         int status;
 155         const char *backend, *backend_func;
 156
 157         add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
 158         add_var(&script_snippet, "state_dir", opts->state_dir);
 159
 160         add_var(&script_snippet, "upstream_name", opts->upstream_name);
 161         add_var(&script_snippet, "upstream",
 162                                  oid_to_hex(&opts->upstream->object.oid));
 163         add_var(&script_snippet, "head_name", opts->head_name);
 164         add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
 165         add_var(&script_snippet, "onto", oid_to_hex(&opts->onto->object.oid));
 166         add_var(&script_snippet, "onto_name", opts->onto_name);
 167         add_var(&script_snippet, "revisions", opts->revisions);
 168         add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
 169                 oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
 170         add_var(&script_snippet, "GIT_QUIET",
 171                 opts->flags & REBASE_NO_QUIET ? "" : "t");
 172         add_var(&script_snippet, "git_am_opt", opts->git_am_opt.buf);
 173         add_var(&script_snippet, "verbose",
 174                 opts->flags & REBASE_VERBOSE ? "t" : "");
 175         add_var(&script_snippet, "diffstat",
 176                 opts->flags & REBASE_DIFFSTAT ? "t" : "");
 177
 178         switch (opts->type) {
 179         case REBASE_AM:
 180                 backend = "git-rebase--am";
 181                 backend_func = "git_rebase__am";
 182                 break;
 183         case REBASE_INTERACTIVE:
 184                 backend = "git-rebase--interactive";
 185                 backend_func = "git_rebase__interactive";
 186                 break;
 187         case REBASE_MERGE:
 188                 backend = "git-rebase--merge";
 189                 backend_func = "git_rebase__merge";
 190                 break;
 191         case REBASE_PRESERVE_MERGES:
 192                 backend = "git-rebase--preserve-merges";
 193                 backend_func = "git_rebase__preserve_merges";
 194                 break;
 195         default:
 196                 BUG("Unhandled rebase type %d", opts->type);
 197                 break;
 198         }
 199
 200         strbuf_addf(&script_snippet,
 201                     ". git-sh-setup && . git-rebase--common &&"
 202                     " . %s && %s", backend, backend_func);
 203         argv[0] = script_snippet.buf;
 204
 205         status = run_command_v_opt(argv, RUN_USING_SHELL);
 206         if (opts->dont_finish_rebase)
 207                 ; /* do nothing */
 208         else if (status == 0) {
 209                 if (!file_exists(state_dir_path("stopped-sha", opts)))
 210                         finish_rebase(opts);
 211         } else if (status == 2) {
 212                 struct strbuf dir = STRBUF_INIT;
 213
 214                 apply_autostash();
 215                 strbuf_addstr(&dir, opts->state_dir);
 216                 remove_dir_recursively(&dir, 0);
 217                 strbuf_release(&dir);
 218                 die("Nothing to do");
 219         }
 220
 221         strbuf_release(&script_snippet);
 222
 223         return status ? -1 : 0;
 224 }
 225
 226 #define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 227
 228 static int reset_head(struct object_id *oid, const char *action,
 229                       const char *switch_to_branch, int detach_head)
 230 {
 231         struct object_id head_oid;
 232         struct tree_desc desc;
 233         struct lock_file lock = LOCK_INIT;
 234         struct unpack_trees_options unpack_tree_opts;
 235         struct tree *tree;
 236         const char *reflog_action;
 237         struct strbuf msg = STRBUF_INIT;
 238         size_t prefix_len;
 239         struct object_id *orig = NULL, oid_orig,
 240                 *old_orig = NULL, oid_old_orig;
 241         int ret = 0;
 242
 243         if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0)
 244                 return -1;
 245
 246         if (!oid) {
 247                 if (get_oid("HEAD", &head_oid)) {
 248                         rollback_lock_file(&lock);
 249                         return error(_("could not determine HEAD revision"));
 250                 }
 251                 oid = &head_oid;
 252         }
 253
 254         memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 255         setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 256         unpack_tree_opts.head_idx = 1;
 257         unpack_tree_opts.src_index = the_repository->index;
 258         unpack_tree_opts.dst_index = the_repository->index;
 259         unpack_tree_opts.fn = oneway_merge;
 260         unpack_tree_opts.update = 1;
 261         unpack_tree_opts.merge = 1;
 262         if (!detach_head)
 263                 unpack_tree_opts.reset = 1;
 264
 265         if (read_index_unmerged(the_repository->index) < 0) {
 266                 rollback_lock_file(&lock);
 267                 return error(_("could not read index"));
 268         }
 269
 270         if (!fill_tree_descriptor(&desc, oid)) {
 271                 error(_("failed to find tree of %s"), oid_to_hex(oid));
 272                 rollback_lock_file(&lock);
 273                 free((void *)desc.buffer);
 274                 return -1;
 275         }
 276
 277         if (unpack_trees(1, &desc, &unpack_tree_opts)) {
 278                 rollback_lock_file(&lock);
 279                 free((void *)desc.buffer);
 280                 return -1;
 281         }
 282
 283         tree = parse_tree_indirect(oid);
 284         prime_cache_tree(the_repository->index, tree);
 285
 286         if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0)
 287                 ret = error(_("could not write index"));
 288         free((void *)desc.buffer);
 289
 290         if (ret)
 291                 return ret;
 292
 293         reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 294         strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 295         prefix_len = msg.len;
 296
 297         if (!get_oid("ORIG_HEAD", &oid_old_orig))
 298                 old_orig = &oid_old_orig;
 299         if (!get_oid("HEAD", &oid_orig)) {
 300                 orig = &oid_orig;
 301                 strbuf_addstr(&msg, "updating ORIG_HEAD");
 302                 update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0,
 303                            UPDATE_REFS_MSG_ON_ERR);
 304         } else if (old_orig)
 305                 delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 306         strbuf_setlen(&msg, prefix_len);
 307         strbuf_addstr(&msg, "updating HEAD");
 308         if (!switch_to_branch)
 309                 ret = update_ref(msg.buf, "HEAD", oid, orig, REF_NO_DEREF,
 310                                  UPDATE_REFS_MSG_ON_ERR);
 311         else {
 312                 ret = create_symref("HEAD", switch_to_branch, msg.buf);
 313                 if (!ret)
 314                         ret = update_ref(msg.buf, "HEAD", oid, NULL, 0,
 315                                          UPDATE_REFS_MSG_ON_ERR);
 316         }
 317
 318         strbuf_release(&msg);
 319         return ret;
 320 }
 321
 322 static int rebase_config(const char *var, const char *value, void *data)
 323 {
 324         struct rebase_options *opts = data;
 325
 326         if (!strcmp(var, "rebase.stat")) {
 327                 if (git_config_bool(var, value))
 328                         opts->flags |= REBASE_DIFFSTAT;
 329                 else
 330                         opts->flags &= !REBASE_DIFFSTAT;
 331                 return 0;
 332         }
 333
 334         return git_default_config(var, value, data);
 335 }
 336
 337 int cmd_rebase(int argc, const char **argv, const char *prefix)
 338 {
 339         struct rebase_options options = {
 340                 .type = REBASE_UNSPECIFIED,
 341                 .flags = REBASE_NO_QUIET,
 342                 .git_am_opt = STRBUF_INIT,
 343         };
 344         const char *branch_name;
 345         int ret, flags;
 346         int ok_to_skip_pre_rebase = 0;
 347         struct strbuf msg = STRBUF_INIT;
 348         struct strbuf revisions = STRBUF_INIT;
 349         struct object_id merge_base;
 350         struct option builtin_rebase_options[] = {
 351                 OPT_STRING(0, "onto", &options.onto_name,
 352                            N_("revision"),
 353                            N_("rebase onto given branch instead of upstream")),
 354                 OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
 355                          N_("allow pre-rebase hook to run")),
 356                 OPT_NEGBIT('q', "quiet", &options.flags,
 357                            N_("be quiet. implies --no-stat"),
 358                            REBASE_NO_QUIET| REBASE_VERBOSE | REBASE_DIFFSTAT),
 359                 OPT_BIT('v', "verbose", &options.flags,
 360                         N_("display a diffstat of what changed upstream"),
 361                         REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
 362                 {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
 363                         N_("do not show diffstat of what changed upstream"),
 364                         PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
 365                 OPT_END(),
 366         };
 367
 368         /*
 369          * NEEDSWORK: Once the builtin rebase has been tested enough
 370          * and git-legacy-rebase.sh is retired to contrib/, this preamble
 371          * can be removed.
 372          */
 373
 374         if (!use_builtin_rebase()) {
 375                 const char *path = mkpath("%s/git-legacy-rebase",
 376                                           git_exec_path());
 377
 378                 if (sane_execvp(path, (char **)argv) < 0)
 379                         die_errno(_("could not exec %s"), path);
 380                 else
 381                         BUG("sane_execvp() returned???");
 382         }
 383
 384         if (argc == 2 && !strcmp(argv[1], "-h"))
 385                 usage_with_options(builtin_rebase_usage,
 386                                    builtin_rebase_options);
 387
 388         prefix = setup_git_directory();
 389         trace_repo_setup(prefix);
 390         setup_work_tree();
 391
 392         git_config(rebase_config, &options);
 393
 394         argc = parse_options(argc, argv, prefix,
 395                              builtin_rebase_options,
 396                              builtin_rebase_usage, 0);
 397
 398         if (argc > 2)
 399                 usage_with_options(builtin_rebase_usage,
 400                                    builtin_rebase_options);
 401
 402         if (!(options.flags & REBASE_NO_QUIET))
 403                 strbuf_addstr(&options.git_am_opt, " -q");
 404
 405         switch (options.type) {
 406         case REBASE_MERGE:
 407         case REBASE_INTERACTIVE:
 408         case REBASE_PRESERVE_MERGES:
 409                 options.state_dir = merge_dir();
 410                 break;
 411         case REBASE_AM:
 412                 options.state_dir = apply_dir();
 413                 break;
 414         default:
 415                 /* the default rebase backend is `--am` */
 416                 options.type = REBASE_AM;
 417                 options.state_dir = apply_dir();
 418                 break;
 419         }
 420
 421         if (!options.root) {
 422                 if (argc < 1)
 423                         die("TODO: handle @{upstream}");
 424                 else {
 425                         options.upstream_name = argv[0];
 426                         argc--;
 427                         argv++;
 428                         if (!strcmp(options.upstream_name, "-"))
 429                                 options.upstream_name = "@{-1}";
 430                 }
 431                 options.upstream = peel_committish(options.upstream_name);
 432                 if (!options.upstream)
 433                         die(_("invalid upstream '%s'"), options.upstream_name);
 434                 options.upstream_arg = options.upstream_name;
 435         } else
 436                 die("TODO: upstream for --root");
 437
 438         /* Make sure the branch to rebase onto is valid. */
 439         if (!options.onto_name)
 440                 options.onto_name = options.upstream_name;
 441         if (strstr(options.onto_name, "...")) {
 442                 if (get_oid_mb(options.onto_name, &merge_base) < 0)
 443                         die(_("'%s': need exactly one merge base"),
 444                             options.onto_name);
 445                 options.onto = lookup_commit_or_die(&merge_base,
 446                                                     options.onto_name);
 447         } else {
 448                 options.onto = peel_committish(options.onto_name);
 449                 if (!options.onto)
 450                         die(_("Does not point to a valid commit '%s'"),
 451                                 options.onto_name);
 452         }
 453
 454         /*
 455          * If the branch to rebase is given, that is the branch we will rebase
 456          * branch_name -- branch/commit being rebased, or
 457          *                HEAD (already detached)
 458          * orig_head -- commit object name of tip of the branch before rebasing
 459          * head_name -- refs/heads/<that-branch> or "detached HEAD"
 460          */
 461         if (argc > 0)
 462                  die("TODO: handle switch_to");
 463         else {
 464                 /* Do not need to switch branches, we are already on it. */
 465                 options.head_name =
 466                         xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
 467                                          &flags));
 468                 if (!options.head_name)
 469                         die(_("No such ref: %s"), "HEAD");
 470                 if (flags & REF_ISSYMREF) {
 471                         if (!skip_prefix(options.head_name,
 472                                          "refs/heads/", &branch_name))
 473                                 branch_name = options.head_name;
 474
 475                 } else {
 476                         options.head_name = xstrdup("detached HEAD");
 477                         branch_name = "HEAD";
 478                 }
 479                 if (get_oid("HEAD", &options.orig_head))
 480                         die(_("Could not resolve HEAD to a revision"));
 481         }
 482
 483         if (read_index(the_repository->index) < 0)
 484                 die(_("could not read index"));
 485
 486         if (require_clean_work_tree("rebase",
 487                                     _("Please commit or stash them."), 1, 1)) {
 488                 ret = 1;
 489                 goto cleanup;
 490         }
 491
 492         /* If a hook exists, give it a chance to interrupt*/
 493         if (!ok_to_skip_pre_rebase &&
 494             run_hook_le(NULL, "pre-rebase", options.upstream_arg,
 495                         argc ? argv[0] : NULL, NULL))
 496                 die(_("The pre-rebase hook refused to rebase."));
 497
 498         if (options.flags & REBASE_DIFFSTAT) {
 499                 struct diff_options opts;
 500
 501                 if (options.flags & REBASE_VERBOSE)
 502                         printf(_("Changes from %s to %s:\n"),
 503                                 oid_to_hex(&merge_base),
 504                                 oid_to_hex(&options.onto->object.oid));
 505
 506                 /* We want color (if set), but no pager */
 507                 diff_setup(&opts);
 508                 opts.stat_width = -1; /* use full terminal width */
 509                 opts.stat_graph_width = -1; /* respect statGraphWidth config */
 510                 opts.output_format |=
 511                         DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
 512                 opts.detect_rename = DIFF_DETECT_RENAME;
 513                 diff_setup_done(&opts);
 514                 diff_tree_oid(&merge_base, &options.onto->object.oid,
 515                               "", &opts);
 516                 diffcore_std(&opts);
 517                 diff_flush(&opts);
 518         }
 519
 520         /* Detach HEAD and reset the tree */
 521         if (options.flags & REBASE_NO_QUIET)
 522                 printf(_("First, rewinding head to replay your work on top of "
 523                          "it...\n"));
 524
 525         strbuf_addf(&msg, "rebase: checkout %s", options.onto_name);
 526         if (reset_head(&options.onto->object.oid, "checkout", NULL, 1))
 527                 die(_("Could not detach HEAD"));
 528         strbuf_release(&msg);
 529
 530         strbuf_addf(&revisions, "%s..%s",
 531                     options.root ? oid_to_hex(&options.onto->object.oid) :
 532                     (options.restrict_revision ?
 533                      oid_to_hex(&options.restrict_revision->object.oid) :
 534                      oid_to_hex(&options.upstream->object.oid)),
 535                     oid_to_hex(&options.orig_head));
 536
 537         options.revisions = revisions.buf;
 538
 539         ret = !!run_specific_rebase(&options);
 540
 541 cleanup:
 542         strbuf_release(&revisions);
 543         free(options.head_name);
 544         return ret;
 545 }