Andrew's git - gitweb.git/blob

2d3f1d65fb5e1cf7d1c6e4853ea6c4db324be4e9
   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
  23static char const * const builtin_rebase_usage[] = {
  24        N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  25                "[<upstream>] [<branch>]"),
  26        N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  27                "--root [<branch>]"),
  28        N_("git rebase --continue | --abort | --skip | --edit-todo"),
  29        NULL
  30};
  31
  32static GIT_PATH_FUNC(apply_dir, "rebase-apply")
  33static GIT_PATH_FUNC(merge_dir, "rebase-merge")
  34
  35enum rebase_type {
  36        REBASE_UNSPECIFIED = -1,
  37        REBASE_AM,
  38        REBASE_MERGE,
  39        REBASE_INTERACTIVE,
  40        REBASE_PRESERVE_MERGES
  41};
  42
  43static int use_builtin_rebase(void)
  44{
  45        struct child_process cp = CHILD_PROCESS_INIT;
  46        struct strbuf out = STRBUF_INIT;
  47        int ret;
  48
  49        argv_array_pushl(&cp.args,
  50                         "config", "--bool", "rebase.usebuiltin", NULL);
  51        cp.git_cmd = 1;
  52        if (capture_command(&cp, &out, 6)) {
  53                strbuf_release(&out);
  54                return 0;
  55        }
  56
  57        strbuf_trim(&out);
  58        ret = !strcmp("true", out.buf);
  59        strbuf_release(&out);
  60        return ret;
  61}
  62
  63static int apply_autostash(void)
  64{
  65        warning("TODO");
  66        return 0;
  67}
  68
  69struct rebase_options {
  70        enum rebase_type type;
  71        const char *state_dir;
  72        struct commit *upstream;
  73        const char *upstream_name;
  74        const char *upstream_arg;
  75        char *head_name;
  76        struct object_id orig_head;
  77        struct commit *onto;
  78        const char *onto_name;
  79        const char *revisions;
  80        int root;
  81        struct commit *restrict_revision;
  82        int dont_finish_rebase;
  83        enum {
  84                REBASE_NO_QUIET = 1<<0,
  85                REBASE_VERBOSE = 1<<1,
  86                REBASE_DIFFSTAT = 1<<2,
  87        } flags;
  88        struct strbuf git_am_opt;
  89};
  90
  91/* Returns the filename prefixed by the state_dir */
  92static const char *state_dir_path(const char *filename, struct rebase_options *opts)
  93{
  94        static struct strbuf path = STRBUF_INIT;
  95        static size_t prefix_len;
  96
  97        if (!prefix_len) {
  98                strbuf_addf(&path, "%s/", opts->state_dir);
  99                prefix_len = path.len;
 100        }
 101
 102        strbuf_setlen(&path, prefix_len);
 103        strbuf_addstr(&path, filename);
 104        return path.buf;
 105}
 106
 107static int finish_rebase(struct rebase_options *opts)
 108{
 109        struct strbuf dir = STRBUF_INIT;
 110        const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 111
 112        delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 113        apply_autostash();
 114        close_all_packs(the_repository->objects);
 115        /*
 116         * We ignore errors in 'gc --auto', since the
 117         * user should see them.
 118         */
 119        run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 120        strbuf_addstr(&dir, opts->state_dir);
 121        remove_dir_recursively(&dir, 0);
 122        strbuf_release(&dir);
 123
 124        return 0;
 125}
 126
 127static struct commit *peel_committish(const char *name)
 128{
 129        struct object *obj;
 130        struct object_id oid;
 131
 132        if (get_oid(name, &oid))
 133                return NULL;
 134        obj = parse_object(the_repository, &oid);
 135        return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 136}
 137
 138static void add_var(struct strbuf *buf, const char *name, const char *value)
 139{
 140        if (!value)
 141                strbuf_addf(buf, "unset %s; ", name);
 142        else {
 143                strbuf_addf(buf, "%s=", name);
 144                sq_quote_buf(buf, value);
 145                strbuf_addstr(buf, "; ");
 146        }
 147}
 148
 149static int run_specific_rebase(struct rebase_options *opts)
 150{
 151        const char *argv[] = { NULL, NULL };
 152        struct strbuf script_snippet = STRBUF_INIT;
 153        int status;
 154        const char *backend, *backend_func;
 155
 156        add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
 157        add_var(&script_snippet, "state_dir", opts->state_dir);
 158
 159        add_var(&script_snippet, "upstream_name", opts->upstream_name);
 160        add_var(&script_snippet, "upstream",
 161                                 oid_to_hex(&opts->upstream->object.oid));
 162        add_var(&script_snippet, "head_name", opts->head_name);
 163        add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
 164        add_var(&script_snippet, "onto", oid_to_hex(&opts->onto->object.oid));
 165        add_var(&script_snippet, "onto_name", opts->onto_name);
 166        add_var(&script_snippet, "revisions", opts->revisions);
 167        add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
 168                oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
 169        add_var(&script_snippet, "GIT_QUIET",
 170                opts->flags & REBASE_NO_QUIET ? "" : "t");
 171        add_var(&script_snippet, "git_am_opt", opts->git_am_opt.buf);
 172        add_var(&script_snippet, "verbose",
 173                opts->flags & REBASE_VERBOSE ? "t" : "");
 174        add_var(&script_snippet, "diffstat",
 175                opts->flags & REBASE_DIFFSTAT ? "t" : "");
 176
 177        switch (opts->type) {
 178        case REBASE_AM:
 179                backend = "git-rebase--am";
 180                backend_func = "git_rebase__am";
 181                break;
 182        case REBASE_INTERACTIVE:
 183                backend = "git-rebase--interactive";
 184                backend_func = "git_rebase__interactive";
 185                break;
 186        case REBASE_MERGE:
 187                backend = "git-rebase--merge";
 188                backend_func = "git_rebase__merge";
 189                break;
 190        case REBASE_PRESERVE_MERGES:
 191                backend = "git-rebase--preserve-merges";
 192                backend_func = "git_rebase__preserve_merges";
 193                break;
 194        default:
 195                BUG("Unhandled rebase type %d", opts->type);
 196                break;
 197        }
 198
 199        strbuf_addf(&script_snippet,
 200                    ". git-sh-setup && . git-rebase--common &&"
 201                    " . %s && %s", backend, backend_func);
 202        argv[0] = script_snippet.buf;
 203
 204        status = run_command_v_opt(argv, RUN_USING_SHELL);
 205        if (opts->dont_finish_rebase)
 206                ; /* do nothing */
 207        else if (status == 0) {
 208                if (!file_exists(state_dir_path("stopped-sha", opts)))
 209                        finish_rebase(opts);
 210        } else if (status == 2) {
 211                struct strbuf dir = STRBUF_INIT;
 212
 213                apply_autostash();
 214                strbuf_addstr(&dir, opts->state_dir);
 215                remove_dir_recursively(&dir, 0);
 216                strbuf_release(&dir);
 217                die("Nothing to do");
 218        }
 219
 220        strbuf_release(&script_snippet);
 221
 222        return status ? -1 : 0;
 223}
 224
 225#define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 226
 227static int reset_head(struct object_id *oid, const char *action,
 228                      const char *switch_to_branch, int detach_head)
 229{
 230        struct object_id head_oid;
 231        struct tree_desc desc;
 232        struct lock_file lock = LOCK_INIT;
 233        struct unpack_trees_options unpack_tree_opts;
 234        struct tree *tree;
 235        const char *reflog_action;
 236        struct strbuf msg = STRBUF_INIT;
 237        size_t prefix_len;
 238        struct object_id *orig = NULL, oid_orig,
 239                *old_orig = NULL, oid_old_orig;
 240        int ret = 0;
 241
 242        if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0)
 243                return -1;
 244
 245        if (!oid) {
 246                if (get_oid("HEAD", &head_oid)) {
 247                        rollback_lock_file(&lock);
 248                        return error(_("could not determine HEAD revision"));
 249                }
 250                oid = &head_oid;
 251        }
 252
 253        memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 254        setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 255        unpack_tree_opts.head_idx = 1;
 256        unpack_tree_opts.src_index = the_repository->index;
 257        unpack_tree_opts.dst_index = the_repository->index;
 258        unpack_tree_opts.fn = oneway_merge;
 259        unpack_tree_opts.update = 1;
 260        unpack_tree_opts.merge = 1;
 261        if (!detach_head)
 262                unpack_tree_opts.reset = 1;
 263
 264        if (read_index_unmerged(the_repository->index) < 0) {
 265                rollback_lock_file(&lock);
 266                return error(_("could not read index"));
 267        }
 268
 269        if (!fill_tree_descriptor(&desc, oid)) {
 270                error(_("failed to find tree of %s"), oid_to_hex(oid));
 271                rollback_lock_file(&lock);
 272                free((void *)desc.buffer);
 273                return -1;
 274        }
 275
 276        if (unpack_trees(1, &desc, &unpack_tree_opts)) {
 277                rollback_lock_file(&lock);
 278                free((void *)desc.buffer);
 279                return -1;
 280        }
 281
 282        tree = parse_tree_indirect(oid);
 283        prime_cache_tree(the_repository->index, tree);
 284
 285        if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0)
 286                ret = error(_("could not write index"));
 287        free((void *)desc.buffer);
 288
 289        if (ret)
 290                return ret;
 291
 292        reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 293        strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 294        prefix_len = msg.len;
 295
 296        if (!get_oid("ORIG_HEAD", &oid_old_orig))
 297                old_orig = &oid_old_orig;
 298        if (!get_oid("HEAD", &oid_orig)) {
 299                orig = &oid_orig;
 300                strbuf_addstr(&msg, "updating ORIG_HEAD");
 301                update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0,
 302                           UPDATE_REFS_MSG_ON_ERR);
 303        } else if (old_orig)
 304                delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 305        strbuf_setlen(&msg, prefix_len);
 306        strbuf_addstr(&msg, "updating HEAD");
 307        if (!switch_to_branch)
 308                ret = update_ref(msg.buf, "HEAD", oid, orig, REF_NO_DEREF,
 309                                 UPDATE_REFS_MSG_ON_ERR);
 310        else {
 311                ret = create_symref("HEAD", switch_to_branch, msg.buf);
 312                if (!ret)
 313                        ret = update_ref(msg.buf, "HEAD", oid, NULL, 0,
 314                                         UPDATE_REFS_MSG_ON_ERR);
 315        }
 316
 317        strbuf_release(&msg);
 318        return ret;
 319}
 320
 321static int rebase_config(const char *var, const char *value, void *data)
 322{
 323        struct rebase_options *opts = data;
 324
 325        if (!strcmp(var, "rebase.stat")) {
 326                if (git_config_bool(var, value))
 327                        opts->flags |= REBASE_DIFFSTAT;
 328                else
 329                        opts->flags &= !REBASE_DIFFSTAT;
 330                return 0;
 331        }
 332
 333        return git_default_config(var, value, data);
 334}
 335
 336int cmd_rebase(int argc, const char **argv, const char *prefix)
 337{
 338        struct rebase_options options = {
 339                .type = REBASE_UNSPECIFIED,
 340                .flags = REBASE_NO_QUIET,
 341                .git_am_opt = STRBUF_INIT,
 342        };
 343        const char *branch_name;
 344        int ret, flags;
 345        int ok_to_skip_pre_rebase = 0;
 346        struct strbuf msg = STRBUF_INIT;
 347        struct strbuf revisions = STRBUF_INIT;
 348        struct object_id merge_base;
 349        struct option builtin_rebase_options[] = {
 350                OPT_STRING(0, "onto", &options.onto_name,
 351                           N_("revision"),
 352                           N_("rebase onto given branch instead of upstream")),
 353                OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
 354                         N_("allow pre-rebase hook to run")),
 355                OPT_NEGBIT('q', "quiet", &options.flags,
 356                           N_("be quiet. implies --no-stat"),
 357                           REBASE_NO_QUIET| REBASE_VERBOSE | REBASE_DIFFSTAT),
 358                OPT_BIT('v', "verbose", &options.flags,
 359                        N_("display a diffstat of what changed upstream"),
 360                        REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
 361                {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
 362                        N_("do not show diffstat of what changed upstream"),
 363                        PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
 364                OPT_END(),
 365        };
 366
 367        /*
 368         * NEEDSWORK: Once the builtin rebase has been tested enough
 369         * and git-legacy-rebase.sh is retired to contrib/, this preamble
 370         * can be removed.
 371         */
 372
 373        if (!use_builtin_rebase()) {
 374                const char *path = mkpath("%s/git-legacy-rebase",
 375                                          git_exec_path());
 376
 377                if (sane_execvp(path, (char **)argv) < 0)
 378                        die_errno(_("could not exec %s"), path);
 379                else
 380                        BUG("sane_execvp() returned???");
 381        }
 382
 383        if (argc == 2 && !strcmp(argv[1], "-h"))
 384                usage_with_options(builtin_rebase_usage,
 385                                   builtin_rebase_options);
 386
 387        prefix = setup_git_directory();
 388        trace_repo_setup(prefix);
 389        setup_work_tree();
 390
 391        git_config(rebase_config, &options);
 392
 393        argc = parse_options(argc, argv, prefix,
 394                             builtin_rebase_options,
 395                             builtin_rebase_usage, 0);
 396
 397        if (argc > 2)
 398                usage_with_options(builtin_rebase_usage,
 399                                   builtin_rebase_options);
 400
 401        if (!(options.flags & REBASE_NO_QUIET))
 402                strbuf_addstr(&options.git_am_opt, " -q");
 403
 404        switch (options.type) {
 405        case REBASE_MERGE:
 406        case REBASE_INTERACTIVE:
 407        case REBASE_PRESERVE_MERGES:
 408                options.state_dir = merge_dir();
 409                break;
 410        case REBASE_AM:
 411                options.state_dir = apply_dir();
 412                break;
 413        default:
 414                /* the default rebase backend is `--am` */
 415                options.type = REBASE_AM;
 416                options.state_dir = apply_dir();
 417                break;
 418        }
 419
 420        if (!options.root) {
 421                if (argc < 1)
 422                        die("TODO: handle @{upstream}");
 423                else {
 424                        options.upstream_name = argv[0];
 425                        argc--;
 426                        argv++;
 427                        if (!strcmp(options.upstream_name, "-"))
 428                                options.upstream_name = "@{-1}";
 429                }
 430                options.upstream = peel_committish(options.upstream_name);
 431                if (!options.upstream)
 432                        die(_("invalid upstream '%s'"), options.upstream_name);
 433                options.upstream_arg = options.upstream_name;
 434        } else
 435                die("TODO: upstream for --root");
 436
 437        /* Make sure the branch to rebase onto is valid. */
 438        if (!options.onto_name)
 439                options.onto_name = options.upstream_name;
 440        if (strstr(options.onto_name, "...")) {
 441                if (get_oid_mb(options.onto_name, &merge_base) < 0)
 442                        die(_("'%s': need exactly one merge base"),
 443                            options.onto_name);
 444                options.onto = lookup_commit_or_die(&merge_base,
 445                                                    options.onto_name);
 446        } else {
 447                options.onto = peel_committish(options.onto_name);
 448                if (!options.onto)
 449                        die(_("Does not point to a valid commit '%s'"),
 450                                options.onto_name);
 451        }
 452
 453        /*
 454         * If the branch to rebase is given, that is the branch we will rebase
 455         * branch_name -- branch/commit being rebased, or
 456         *                HEAD (already detached)
 457         * orig_head -- commit object name of tip of the branch before rebasing
 458         * head_name -- refs/heads/<that-branch> or "detached HEAD"
 459         */
 460        if (argc > 0)
 461                 die("TODO: handle switch_to");
 462        else {
 463                /* Do not need to switch branches, we are already on it. */
 464                options.head_name =
 465                        xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
 466                                         &flags));
 467                if (!options.head_name)
 468                        die(_("No such ref: %s"), "HEAD");
 469                if (flags & REF_ISSYMREF) {
 470                        if (!skip_prefix(options.head_name,
 471                                         "refs/heads/", &branch_name))
 472                                branch_name = options.head_name;
 473
 474                } else {
 475                        options.head_name = xstrdup("detached HEAD");
 476                        branch_name = "HEAD";
 477                }
 478                if (get_oid("HEAD", &options.orig_head))
 479                        die(_("Could not resolve HEAD to a revision"));
 480        }
 481
 482        /* If a hook exists, give it a chance to interrupt*/
 483        if (!ok_to_skip_pre_rebase &&
 484            run_hook_le(NULL, "pre-rebase", options.upstream_arg,
 485                        argc ? argv[0] : NULL, NULL))
 486                die(_("The pre-rebase hook refused to rebase."));
 487
 488        if (options.flags & REBASE_DIFFSTAT) {
 489                struct diff_options opts;
 490
 491                if (options.flags & REBASE_VERBOSE)
 492                        printf(_("Changes from %s to %s:\n"),
 493                                oid_to_hex(&merge_base),
 494                                oid_to_hex(&options.onto->object.oid));
 495
 496                /* We want color (if set), but no pager */
 497                diff_setup(&opts);
 498                opts.stat_width = -1; /* use full terminal width */
 499                opts.stat_graph_width = -1; /* respect statGraphWidth config */
 500                opts.output_format |=
 501                        DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
 502                opts.detect_rename = DIFF_DETECT_RENAME;
 503                diff_setup_done(&opts);
 504                diff_tree_oid(&merge_base, &options.onto->object.oid,
 505                              "", &opts);
 506                diffcore_std(&opts);
 507                diff_flush(&opts);
 508        }
 509
 510        /* Detach HEAD and reset the tree */
 511        if (options.flags & REBASE_NO_QUIET)
 512                printf(_("First, rewinding head to replay your work on top of "
 513                         "it...\n"));
 514
 515        strbuf_addf(&msg, "rebase: checkout %s", options.onto_name);
 516        if (reset_head(&options.onto->object.oid, "checkout", NULL, 1))
 517                die(_("Could not detach HEAD"));
 518        strbuf_release(&msg);
 519
 520        strbuf_addf(&revisions, "%s..%s",
 521                    options.root ? oid_to_hex(&options.onto->object.oid) :
 522                    (options.restrict_revision ?
 523                     oid_to_hex(&options.restrict_revision->object.oid) :
 524                     oid_to_hex(&options.upstream->object.oid)),
 525                    oid_to_hex(&options.orig_head));
 526
 527        options.revisions = revisions.buf;
 528
 529        ret = !!run_specific_rebase(&options);
 530
 531        strbuf_release(&revisions);
 532        free(options.head_name);
 533        return ret;
 534}