Andrew's git - gitweb.git/blob

19fa4d3fc488c9f6953bc49b5a8c486e72956de1
   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        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 */
  89static 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
 104static 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
 124static 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
 135static 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
 146static 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
 220static 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
 314int 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}