Andrew's git - gitweb.git/blob

   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
  22static 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
  31static GIT_PATH_FUNC(apply_dir, "rebase-apply")
  32static GIT_PATH_FUNC(merge_dir, "rebase-merge")
  33
  34enum rebase_type {
  35        REBASE_UNSPECIFIED = -1,
  36        REBASE_AM,
  37        REBASE_MERGE,
  38        REBASE_INTERACTIVE,
  39        REBASE_PRESERVE_MERGES
  40};
  41
  42static 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
  62static int apply_autostash(void)
  63{
  64        warning("TODO");
  65        return 0;
  66}
  67
  68struct 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 */
  85static 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
 100static 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
 120static 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
 131static 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
 142static 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
 213static 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
 307int 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}