Andrew's git - gitweb.git/blob

38c496dd10baeab8545a4c2a5475d89aec512546
   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        char *head_name;
  74        struct object_id orig_head;
  75        struct commit *onto;
  76        const char *onto_name;
  77        const char *revisions;
  78        int root;
  79        struct commit *restrict_revision;
  80        int dont_finish_rebase;
  81};
  82
  83/* Returns the filename prefixed by the state_dir */
  84static const char *state_dir_path(const char *filename, struct rebase_options *opts)
  85{
  86        static struct strbuf path = STRBUF_INIT;
  87        static size_t prefix_len;
  88
  89        if (!prefix_len) {
  90                strbuf_addf(&path, "%s/", opts->state_dir);
  91                prefix_len = path.len;
  92        }
  93
  94        strbuf_setlen(&path, prefix_len);
  95        strbuf_addstr(&path, filename);
  96        return path.buf;
  97}
  98
  99static int finish_rebase(struct rebase_options *opts)
 100{
 101        struct strbuf dir = STRBUF_INIT;
 102        const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 103
 104        delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 105        apply_autostash();
 106        close_all_packs(the_repository->objects);
 107        /*
 108         * We ignore errors in 'gc --auto', since the
 109         * user should see them.
 110         */
 111        run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 112        strbuf_addstr(&dir, opts->state_dir);
 113        remove_dir_recursively(&dir, 0);
 114        strbuf_release(&dir);
 115
 116        return 0;
 117}
 118
 119static struct commit *peel_committish(const char *name)
 120{
 121        struct object *obj;
 122        struct object_id oid;
 123
 124        if (get_oid(name, &oid))
 125                return NULL;
 126        obj = parse_object(the_repository, &oid);
 127        return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 128}
 129
 130static void add_var(struct strbuf *buf, const char *name, const char *value)
 131{
 132        if (!value)
 133                strbuf_addf(buf, "unset %s; ", name);
 134        else {
 135                strbuf_addf(buf, "%s=", name);
 136                sq_quote_buf(buf, value);
 137                strbuf_addstr(buf, "; ");
 138        }
 139}
 140
 141static int run_specific_rebase(struct rebase_options *opts)
 142{
 143        const char *argv[] = { NULL, NULL };
 144        struct strbuf script_snippet = STRBUF_INIT;
 145        int status;
 146        const char *backend, *backend_func;
 147
 148        add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
 149        add_var(&script_snippet, "state_dir", opts->state_dir);
 150
 151        add_var(&script_snippet, "upstream_name", opts->upstream_name);
 152        add_var(&script_snippet, "upstream",
 153                                 oid_to_hex(&opts->upstream->object.oid));
 154        add_var(&script_snippet, "head_name", opts->head_name);
 155        add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
 156        add_var(&script_snippet, "onto", oid_to_hex(&opts->onto->object.oid));
 157        add_var(&script_snippet, "onto_name", opts->onto_name);
 158        add_var(&script_snippet, "revisions", opts->revisions);
 159        add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
 160                oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
 161
 162        switch (opts->type) {
 163        case REBASE_AM:
 164                backend = "git-rebase--am";
 165                backend_func = "git_rebase__am";
 166                break;
 167        case REBASE_INTERACTIVE:
 168                backend = "git-rebase--interactive";
 169                backend_func = "git_rebase__interactive";
 170                break;
 171        case REBASE_MERGE:
 172                backend = "git-rebase--merge";
 173                backend_func = "git_rebase__merge";
 174                break;
 175        case REBASE_PRESERVE_MERGES:
 176                backend = "git-rebase--preserve-merges";
 177                backend_func = "git_rebase__preserve_merges";
 178                break;
 179        default:
 180                BUG("Unhandled rebase type %d", opts->type);
 181                break;
 182        }
 183
 184        strbuf_addf(&script_snippet,
 185                    ". git-sh-setup && . git-rebase--common &&"
 186                    " . %s && %s", backend, backend_func);
 187        argv[0] = script_snippet.buf;
 188
 189        status = run_command_v_opt(argv, RUN_USING_SHELL);
 190        if (opts->dont_finish_rebase)
 191                ; /* do nothing */
 192        else if (status == 0) {
 193                if (!file_exists(state_dir_path("stopped-sha", opts)))
 194                        finish_rebase(opts);
 195        } else if (status == 2) {
 196                struct strbuf dir = STRBUF_INIT;
 197
 198                apply_autostash();
 199                strbuf_addstr(&dir, opts->state_dir);
 200                remove_dir_recursively(&dir, 0);
 201                strbuf_release(&dir);
 202                die("Nothing to do");
 203        }
 204
 205        strbuf_release(&script_snippet);
 206
 207        return status ? -1 : 0;
 208}
 209
 210#define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 211
 212static int reset_head(struct object_id *oid, const char *action,
 213                      const char *switch_to_branch, int detach_head)
 214{
 215        struct object_id head_oid;
 216        struct tree_desc desc;
 217        struct lock_file lock = LOCK_INIT;
 218        struct unpack_trees_options unpack_tree_opts;
 219        struct tree *tree;
 220        const char *reflog_action;
 221        struct strbuf msg = STRBUF_INIT;
 222        size_t prefix_len;
 223        struct object_id *orig = NULL, oid_orig,
 224                *old_orig = NULL, oid_old_orig;
 225        int ret = 0;
 226
 227        if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0)
 228                return -1;
 229
 230        if (!oid) {
 231                if (get_oid("HEAD", &head_oid)) {
 232                        rollback_lock_file(&lock);
 233                        return error(_("could not determine HEAD revision"));
 234                }
 235                oid = &head_oid;
 236        }
 237
 238        memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 239        setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 240        unpack_tree_opts.head_idx = 1;
 241        unpack_tree_opts.src_index = the_repository->index;
 242        unpack_tree_opts.dst_index = the_repository->index;
 243        unpack_tree_opts.fn = oneway_merge;
 244        unpack_tree_opts.update = 1;
 245        unpack_tree_opts.merge = 1;
 246        if (!detach_head)
 247                unpack_tree_opts.reset = 1;
 248
 249        if (read_index_unmerged(the_repository->index) < 0) {
 250                rollback_lock_file(&lock);
 251                return error(_("could not read index"));
 252        }
 253
 254        if (!fill_tree_descriptor(&desc, oid)) {
 255                error(_("failed to find tree of %s"), oid_to_hex(oid));
 256                rollback_lock_file(&lock);
 257                free((void *)desc.buffer);
 258                return -1;
 259        }
 260
 261        if (unpack_trees(1, &desc, &unpack_tree_opts)) {
 262                rollback_lock_file(&lock);
 263                free((void *)desc.buffer);
 264                return -1;
 265        }
 266
 267        tree = parse_tree_indirect(oid);
 268        prime_cache_tree(the_repository->index, tree);
 269
 270        if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0)
 271                ret = error(_("could not write index"));
 272        free((void *)desc.buffer);
 273
 274        if (ret)
 275                return ret;
 276
 277        reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 278        strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 279        prefix_len = msg.len;
 280
 281        if (!get_oid("ORIG_HEAD", &oid_old_orig))
 282                old_orig = &oid_old_orig;
 283        if (!get_oid("HEAD", &oid_orig)) {
 284                orig = &oid_orig;
 285                strbuf_addstr(&msg, "updating ORIG_HEAD");
 286                update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0,
 287                           UPDATE_REFS_MSG_ON_ERR);
 288        } else if (old_orig)
 289                delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 290        strbuf_setlen(&msg, prefix_len);
 291        strbuf_addstr(&msg, "updating HEAD");
 292        if (!switch_to_branch)
 293                ret = update_ref(msg.buf, "HEAD", oid, orig, REF_NO_DEREF,
 294                                 UPDATE_REFS_MSG_ON_ERR);
 295        else {
 296                ret = create_symref("HEAD", switch_to_branch, msg.buf);
 297                if (!ret)
 298                        ret = update_ref(msg.buf, "HEAD", oid, NULL, 0,
 299                                         UPDATE_REFS_MSG_ON_ERR);
 300        }
 301
 302        strbuf_release(&msg);
 303        return ret;
 304}
 305
 306int cmd_rebase(int argc, const char **argv, const char *prefix)
 307{
 308        struct rebase_options options = {
 309                .type = REBASE_UNSPECIFIED,
 310        };
 311        const char *branch_name;
 312        int ret, flags;
 313        struct strbuf msg = STRBUF_INIT;
 314        struct strbuf revisions = STRBUF_INIT;
 315        struct object_id merge_base;
 316        struct option builtin_rebase_options[] = {
 317                OPT_STRING(0, "onto", &options.onto_name,
 318                           N_("revision"),
 319                           N_("rebase onto given branch instead of upstream")),
 320                OPT_END(),
 321        };
 322
 323        /*
 324         * NEEDSWORK: Once the builtin rebase has been tested enough
 325         * and git-legacy-rebase.sh is retired to contrib/, this preamble
 326         * can be removed.
 327         */
 328
 329        if (!use_builtin_rebase()) {
 330                const char *path = mkpath("%s/git-legacy-rebase",
 331                                          git_exec_path());
 332
 333                if (sane_execvp(path, (char **)argv) < 0)
 334                        die_errno(_("could not exec %s"), path);
 335                else
 336                        BUG("sane_execvp() returned???");
 337        }
 338
 339        if (argc == 2 && !strcmp(argv[1], "-h"))
 340                usage_with_options(builtin_rebase_usage,
 341                                   builtin_rebase_options);
 342
 343        prefix = setup_git_directory();
 344        trace_repo_setup(prefix);
 345        setup_work_tree();
 346
 347        git_config(git_default_config, NULL);
 348        argc = parse_options(argc, argv, prefix,
 349                             builtin_rebase_options,
 350                             builtin_rebase_usage, 0);
 351
 352        if (argc > 2)
 353                usage_with_options(builtin_rebase_usage,
 354                                   builtin_rebase_options);
 355
 356        switch (options.type) {
 357        case REBASE_MERGE:
 358        case REBASE_INTERACTIVE:
 359        case REBASE_PRESERVE_MERGES:
 360                options.state_dir = merge_dir();
 361                break;
 362        case REBASE_AM:
 363                options.state_dir = apply_dir();
 364                break;
 365        default:
 366                /* the default rebase backend is `--am` */
 367                options.type = REBASE_AM;
 368                options.state_dir = apply_dir();
 369                break;
 370        }
 371
 372        if (!options.root) {
 373                if (argc < 1)
 374                        die("TODO: handle @{upstream}");
 375                else {
 376                        options.upstream_name = argv[0];
 377                        argc--;
 378                        argv++;
 379                        if (!strcmp(options.upstream_name, "-"))
 380                                options.upstream_name = "@{-1}";
 381                }
 382                options.upstream = peel_committish(options.upstream_name);
 383                if (!options.upstream)
 384                        die(_("invalid upstream '%s'"), options.upstream_name);
 385        } else
 386                die("TODO: upstream for --root");
 387
 388        /* Make sure the branch to rebase onto is valid. */
 389        if (!options.onto_name)
 390                options.onto_name = options.upstream_name;
 391        if (strstr(options.onto_name, "...")) {
 392                if (get_oid_mb(options.onto_name, &merge_base) < 0)
 393                        die(_("'%s': need exactly one merge base"),
 394                            options.onto_name);
 395                options.onto = lookup_commit_or_die(&merge_base,
 396                                                    options.onto_name);
 397        } else {
 398                options.onto = peel_committish(options.onto_name);
 399                if (!options.onto)
 400                        die(_("Does not point to a valid commit '%s'"),
 401                                options.onto_name);
 402        }
 403
 404        /*
 405         * If the branch to rebase is given, that is the branch we will rebase
 406         * branch_name -- branch/commit being rebased, or
 407         *                HEAD (already detached)
 408         * orig_head -- commit object name of tip of the branch before rebasing
 409         * head_name -- refs/heads/<that-branch> or "detached HEAD"
 410         */
 411        if (argc > 0)
 412                 die("TODO: handle switch_to");
 413        else {
 414                /* Do not need to switch branches, we are already on it. */
 415                options.head_name =
 416                        xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
 417                                         &flags));
 418                if (!options.head_name)
 419                        die(_("No such ref: %s"), "HEAD");
 420                if (flags & REF_ISSYMREF) {
 421                        if (!skip_prefix(options.head_name,
 422                                         "refs/heads/", &branch_name))
 423                                branch_name = options.head_name;
 424
 425                } else {
 426                        options.head_name = xstrdup("detached HEAD");
 427                        branch_name = "HEAD";
 428                }
 429                if (get_oid("HEAD", &options.orig_head))
 430                        die(_("Could not resolve HEAD to a revision"));
 431        }
 432
 433        strbuf_addf(&msg, "rebase: checkout %s", options.onto_name);
 434        if (reset_head(&options.onto->object.oid, "checkout", NULL, 1))
 435                die(_("Could not detach HEAD"));
 436        strbuf_release(&msg);
 437
 438        strbuf_addf(&revisions, "%s..%s",
 439                    options.root ? oid_to_hex(&options.onto->object.oid) :
 440                    (options.restrict_revision ?
 441                     oid_to_hex(&options.restrict_revision->object.oid) :
 442                     oid_to_hex(&options.upstream->object.oid)),
 443                    oid_to_hex(&options.orig_head));
 444
 445        options.revisions = revisions.buf;
 446
 447        ret = !!run_specific_rebase(&options);
 448
 449        strbuf_release(&revisions);
 450        free(options.head_name);
 451        return ret;
 452}