Andrew's git - gitweb.git/blob

742ed3149824b8b6e2b6080ad9c9a2a60339cf0d
   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
  21static char const * const builtin_rebase_usage[] = {
  22        N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  23                "[<upstream>] [<branch>]"),
  24        N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
  25                "--root [<branch>]"),
  26        N_("git rebase --continue | --abort | --skip | --edit-todo"),
  27        NULL
  28};
  29
  30static GIT_PATH_FUNC(apply_dir, "rebase-apply")
  31static GIT_PATH_FUNC(merge_dir, "rebase-merge")
  32
  33enum rebase_type {
  34        REBASE_UNSPECIFIED = -1,
  35        REBASE_AM,
  36        REBASE_MERGE,
  37        REBASE_INTERACTIVE,
  38        REBASE_PRESERVE_MERGES
  39};
  40
  41static int use_builtin_rebase(void)
  42{
  43        struct child_process cp = CHILD_PROCESS_INIT;
  44        struct strbuf out = STRBUF_INIT;
  45        int ret;
  46
  47        argv_array_pushl(&cp.args,
  48                         "config", "--bool", "rebase.usebuiltin", NULL);
  49        cp.git_cmd = 1;
  50        if (capture_command(&cp, &out, 6)) {
  51                strbuf_release(&out);
  52                return 0;
  53        }
  54
  55        strbuf_trim(&out);
  56        ret = !strcmp("true", out.buf);
  57        strbuf_release(&out);
  58        return ret;
  59}
  60
  61static int apply_autostash(void)
  62{
  63        warning("TODO");
  64        return 0;
  65}
  66
  67struct rebase_options {
  68        enum rebase_type type;
  69        const char *state_dir;
  70        struct commit *upstream;
  71        const char *upstream_name;
  72        char *head_name;
  73        struct object_id orig_head;
  74        struct commit *onto;
  75        const char *onto_name;
  76        const char *revisions;
  77        int root;
  78        struct commit *restrict_revision;
  79        int dont_finish_rebase;
  80};
  81
  82/* Returns the filename prefixed by the state_dir */
  83static const char *state_dir_path(const char *filename, struct rebase_options *opts)
  84{
  85        static struct strbuf path = STRBUF_INIT;
  86        static size_t prefix_len;
  87
  88        if (!prefix_len) {
  89                strbuf_addf(&path, "%s/", opts->state_dir);
  90                prefix_len = path.len;
  91        }
  92
  93        strbuf_setlen(&path, prefix_len);
  94        strbuf_addstr(&path, filename);
  95        return path.buf;
  96}
  97
  98static int finish_rebase(struct rebase_options *opts)
  99{
 100        struct strbuf dir = STRBUF_INIT;
 101        const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 102
 103        delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
 104        apply_autostash();
 105        close_all_packs(the_repository->objects);
 106        /*
 107         * We ignore errors in 'gc --auto', since the
 108         * user should see them.
 109         */
 110        run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 111        strbuf_addstr(&dir, opts->state_dir);
 112        remove_dir_recursively(&dir, 0);
 113        strbuf_release(&dir);
 114
 115        return 0;
 116}
 117
 118static struct commit *peel_committish(const char *name)
 119{
 120        struct object *obj;
 121        struct object_id oid;
 122
 123        if (get_oid(name, &oid))
 124                return NULL;
 125        obj = parse_object(the_repository, &oid);
 126        return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 127}
 128
 129static void add_var(struct strbuf *buf, const char *name, const char *value)
 130{
 131        if (!value)
 132                strbuf_addf(buf, "unset %s; ", name);
 133        else {
 134                strbuf_addf(buf, "%s=", name);
 135                sq_quote_buf(buf, value);
 136                strbuf_addstr(buf, "; ");
 137        }
 138}
 139
 140static int run_specific_rebase(struct rebase_options *opts)
 141{
 142        const char *argv[] = { NULL, NULL };
 143        struct strbuf script_snippet = STRBUF_INIT;
 144        int status;
 145        const char *backend, *backend_func;
 146
 147        add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
 148        add_var(&script_snippet, "state_dir", opts->state_dir);
 149
 150        add_var(&script_snippet, "upstream_name", opts->upstream_name);
 151        add_var(&script_snippet, "upstream",
 152                                 oid_to_hex(&opts->upstream->object.oid));
 153        add_var(&script_snippet, "head_name", opts->head_name);
 154        add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
 155        add_var(&script_snippet, "onto", oid_to_hex(&opts->onto->object.oid));
 156        add_var(&script_snippet, "onto_name", opts->onto_name);
 157        add_var(&script_snippet, "revisions", opts->revisions);
 158        add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
 159                oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
 160
 161        switch (opts->type) {
 162        case REBASE_AM:
 163                backend = "git-rebase--am";
 164                backend_func = "git_rebase__am";
 165                break;
 166        case REBASE_INTERACTIVE:
 167                backend = "git-rebase--interactive";
 168                backend_func = "git_rebase__interactive";
 169                break;
 170        case REBASE_MERGE:
 171                backend = "git-rebase--merge";
 172                backend_func = "git_rebase__merge";
 173                break;
 174        case REBASE_PRESERVE_MERGES:
 175                backend = "git-rebase--preserve-merges";
 176                backend_func = "git_rebase__preserve_merges";
 177                break;
 178        default:
 179                BUG("Unhandled rebase type %d", opts->type);
 180                break;
 181        }
 182
 183        strbuf_addf(&script_snippet,
 184                    ". git-sh-setup && . git-rebase--common &&"
 185                    " . %s && %s", backend, backend_func);
 186        argv[0] = script_snippet.buf;
 187
 188        status = run_command_v_opt(argv, RUN_USING_SHELL);
 189        if (opts->dont_finish_rebase)
 190                ; /* do nothing */
 191        else if (status == 0) {
 192                if (!file_exists(state_dir_path("stopped-sha", opts)))
 193                        finish_rebase(opts);
 194        } else if (status == 2) {
 195                struct strbuf dir = STRBUF_INIT;
 196
 197                apply_autostash();
 198                strbuf_addstr(&dir, opts->state_dir);
 199                remove_dir_recursively(&dir, 0);
 200                strbuf_release(&dir);
 201                die("Nothing to do");
 202        }
 203
 204        strbuf_release(&script_snippet);
 205
 206        return status ? -1 : 0;
 207}
 208
 209#define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 210
 211static int reset_head(struct object_id *oid, const char *action,
 212                      const char *switch_to_branch, int detach_head)
 213{
 214        struct object_id head_oid;
 215        struct tree_desc desc;
 216        struct lock_file lock = LOCK_INIT;
 217        struct unpack_trees_options unpack_tree_opts;
 218        struct tree *tree;
 219        const char *reflog_action;
 220        struct strbuf msg = STRBUF_INIT;
 221        size_t prefix_len;
 222        struct object_id *orig = NULL, oid_orig,
 223                *old_orig = NULL, oid_old_orig;
 224        int ret = 0;
 225
 226        if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0)
 227                return -1;
 228
 229        if (!oid) {
 230                if (get_oid("HEAD", &head_oid)) {
 231                        rollback_lock_file(&lock);
 232                        return error(_("could not determine HEAD revision"));
 233                }
 234                oid = &head_oid;
 235        }
 236
 237        memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 238        setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 239        unpack_tree_opts.head_idx = 1;
 240        unpack_tree_opts.src_index = the_repository->index;
 241        unpack_tree_opts.dst_index = the_repository->index;
 242        unpack_tree_opts.fn = oneway_merge;
 243        unpack_tree_opts.update = 1;
 244        unpack_tree_opts.merge = 1;
 245        if (!detach_head)
 246                unpack_tree_opts.reset = 1;
 247
 248        if (read_index_unmerged(the_repository->index) < 0) {
 249                rollback_lock_file(&lock);
 250                return error(_("could not read index"));
 251        }
 252
 253        if (!fill_tree_descriptor(&desc, oid)) {
 254                error(_("failed to find tree of %s"), oid_to_hex(oid));
 255                rollback_lock_file(&lock);
 256                free((void *)desc.buffer);
 257                return -1;
 258        }
 259
 260        if (unpack_trees(1, &desc, &unpack_tree_opts)) {
 261                rollback_lock_file(&lock);
 262                free((void *)desc.buffer);
 263                return -1;
 264        }
 265
 266        tree = parse_tree_indirect(oid);
 267        prime_cache_tree(the_repository->index, tree);
 268
 269        if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0)
 270                ret = error(_("could not write index"));
 271        free((void *)desc.buffer);
 272
 273        if (ret)
 274                return ret;
 275
 276        reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 277        strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 278        prefix_len = msg.len;
 279
 280        if (!get_oid("ORIG_HEAD", &oid_old_orig))
 281                old_orig = &oid_old_orig;
 282        if (!get_oid("HEAD", &oid_orig)) {
 283                orig = &oid_orig;
 284                strbuf_addstr(&msg, "updating ORIG_HEAD");
 285                update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0,
 286                           UPDATE_REFS_MSG_ON_ERR);
 287        } else if (old_orig)
 288                delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 289        strbuf_setlen(&msg, prefix_len);
 290        strbuf_addstr(&msg, "updating HEAD");
 291        if (!switch_to_branch)
 292                ret = update_ref(msg.buf, "HEAD", oid, orig, REF_NO_DEREF,
 293                                 UPDATE_REFS_MSG_ON_ERR);
 294        else {
 295                ret = create_symref("HEAD", switch_to_branch, msg.buf);
 296                if (!ret)
 297                        ret = update_ref(msg.buf, "HEAD", oid, NULL, 0,
 298                                         UPDATE_REFS_MSG_ON_ERR);
 299        }
 300
 301        strbuf_release(&msg);
 302        return ret;
 303}
 304
 305int cmd_rebase(int argc, const char **argv, const char *prefix)
 306{
 307        struct rebase_options options = {
 308                .type = REBASE_UNSPECIFIED,
 309        };
 310        const char *branch_name;
 311        int ret, flags;
 312        struct strbuf msg = STRBUF_INIT;
 313        struct strbuf revisions = STRBUF_INIT;
 314        struct option builtin_rebase_options[] = {
 315                OPT_STRING(0, "onto", &options.onto_name,
 316                           N_("revision"),
 317                           N_("rebase onto given branch instead of upstream")),
 318                OPT_END(),
 319        };
 320
 321        /*
 322         * NEEDSWORK: Once the builtin rebase has been tested enough
 323         * and git-legacy-rebase.sh is retired to contrib/, this preamble
 324         * can be removed.
 325         */
 326
 327        if (!use_builtin_rebase()) {
 328                const char *path = mkpath("%s/git-legacy-rebase",
 329                                          git_exec_path());
 330
 331                if (sane_execvp(path, (char **)argv) < 0)
 332                        die_errno(_("could not exec %s"), path);
 333                else
 334                        BUG("sane_execvp() returned???");
 335        }
 336
 337        if (argc == 2 && !strcmp(argv[1], "-h"))
 338                usage_with_options(builtin_rebase_usage,
 339                                   builtin_rebase_options);
 340
 341        prefix = setup_git_directory();
 342        trace_repo_setup(prefix);
 343        setup_work_tree();
 344
 345        git_config(git_default_config, NULL);
 346        argc = parse_options(argc, argv, prefix,
 347                             builtin_rebase_options,
 348                             builtin_rebase_usage, 0);
 349
 350        if (argc > 2)
 351                usage_with_options(builtin_rebase_usage,
 352                                   builtin_rebase_options);
 353
 354        switch (options.type) {
 355        case REBASE_MERGE:
 356        case REBASE_INTERACTIVE:
 357        case REBASE_PRESERVE_MERGES:
 358                options.state_dir = merge_dir();
 359                break;
 360        case REBASE_AM:
 361                options.state_dir = apply_dir();
 362                break;
 363        default:
 364                /* the default rebase backend is `--am` */
 365                options.type = REBASE_AM;
 366                options.state_dir = apply_dir();
 367                break;
 368        }
 369
 370        if (!options.root) {
 371                if (argc < 1)
 372                        die("TODO: handle @{upstream}");
 373                else {
 374                        options.upstream_name = argv[0];
 375                        argc--;
 376                        argv++;
 377                        if (!strcmp(options.upstream_name, "-"))
 378                                options.upstream_name = "@{-1}";
 379                }
 380                options.upstream = peel_committish(options.upstream_name);
 381                if (!options.upstream)
 382                        die(_("invalid upstream '%s'"), options.upstream_name);
 383        } else
 384                die("TODO: upstream for --root");
 385
 386        /* Make sure the branch to rebase onto is valid. */
 387        if (!options.onto_name)
 388                options.onto_name = options.upstream_name;
 389        if (strstr(options.onto_name, "...")) {
 390                die("TODO");
 391        } else {
 392                options.onto = peel_committish(options.onto_name);
 393                if (!options.onto)
 394                        die(_("Does not point to a valid commit '%s'"),
 395                                options.onto_name);
 396        }
 397
 398        /*
 399         * If the branch to rebase is given, that is the branch we will rebase
 400         * branch_name -- branch/commit being rebased, or
 401         *                HEAD (already detached)
 402         * orig_head -- commit object name of tip of the branch before rebasing
 403         * head_name -- refs/heads/<that-branch> or "detached HEAD"
 404         */
 405        if (argc > 0)
 406                 die("TODO: handle switch_to");
 407        else {
 408                /* Do not need to switch branches, we are already on it. */
 409                options.head_name =
 410                        xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
 411                                         &flags));
 412                if (!options.head_name)
 413                        die(_("No such ref: %s"), "HEAD");
 414                if (flags & REF_ISSYMREF) {
 415                        if (!skip_prefix(options.head_name,
 416                                         "refs/heads/", &branch_name))
 417                                branch_name = options.head_name;
 418
 419                } else {
 420                        options.head_name = xstrdup("detached HEAD");
 421                        branch_name = "HEAD";
 422                }
 423                if (get_oid("HEAD", &options.orig_head))
 424                        die(_("Could not resolve HEAD to a revision"));
 425        }
 426
 427        strbuf_addf(&msg, "rebase: checkout %s", options.onto_name);
 428        if (reset_head(&options.onto->object.oid, "checkout", NULL, 1))
 429                die(_("Could not detach HEAD"));
 430        strbuf_release(&msg);
 431
 432        strbuf_addf(&revisions, "%s..%s",
 433                    options.root ? oid_to_hex(&options.onto->object.oid) :
 434                    (options.restrict_revision ?
 435                     oid_to_hex(&options.restrict_revision->object.oid) :
 436                     oid_to_hex(&options.upstream->object.oid)),
 437                    oid_to_hex(&options.orig_head));
 438
 439        options.revisions = revisions.buf;
 440
 441        ret = !!run_specific_rebase(&options);
 442
 443        strbuf_release(&revisions);
 444        free(options.head_name);
 445        return ret;
 446}