Andrew's git - gitweb.git/blob

afef0b00462239cc95e8de475407ad6ec2266fe7
   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
  24static 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
  33static GIT_PATH_FUNC(apply_dir, "rebase-apply")
  34static GIT_PATH_FUNC(merge_dir, "rebase-merge")
  35
  36enum rebase_type {
  37        REBASE_UNSPECIFIED = -1,
  38        REBASE_AM,
  39        REBASE_MERGE,
  40        REBASE_INTERACTIVE,
  41        REBASE_PRESERVE_MERGES
  42};
  43
  44static 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
  64static int apply_autostash(void)
  65{
  66        warning("TODO");
  67        return 0;
  68}
  69
  70struct 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 */
  93static 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
 108static 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
 128static 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
 139static 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
 150static 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
 228static 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
 322static 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
 337int 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
 541cleanup:
 542        strbuf_release(&revisions);
 543        free(options.head_name);
 544        return ret;
 545}