Andrew's git - gitweb.git/blob

   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
  20static GIT_PATH_FUNC(apply_dir, "rebase-apply")
  21static GIT_PATH_FUNC(merge_dir, "rebase-merge")
  22
  23enum rebase_type {
  24        REBASE_UNSPECIFIED = -1,
  25        REBASE_AM,
  26        REBASE_MERGE,
  27        REBASE_INTERACTIVE,
  28        REBASE_PRESERVE_MERGES
  29};
  30
  31static int use_builtin_rebase(void)
  32{
  33        struct child_process cp = CHILD_PROCESS_INIT;
  34        struct strbuf out = STRBUF_INIT;
  35        int ret;
  36
  37        argv_array_pushl(&cp.args,
  38                         "config", "--bool", "rebase.usebuiltin", NULL);
  39        cp.git_cmd = 1;
  40        if (capture_command(&cp, &out, 6)) {
  41                strbuf_release(&out);
  42                return 0;
  43        }
  44
  45        strbuf_trim(&out);
  46        ret = !strcmp("true", out.buf);
  47        strbuf_release(&out);
  48        return ret;
  49}
  50
  51static int apply_autostash(void)
  52{
  53        warning("TODO");
  54        return 0;
  55}
  56
  57struct rebase_options {
  58        enum rebase_type type;
  59        const char *state_dir;
  60        struct commit *upstream;
  61        const char *upstream_name;
  62        char *head_name;
  63        struct object_id orig_head;
  64        struct commit *onto;
  65        const char *onto_name;
  66        const char *revisions;
  67        int root;
  68        struct commit *restrict_revision;
  69        int dont_finish_rebase;
  70};
  71
  72/* Returns the filename prefixed by the state_dir */
  73static const char *state_dir_path(const char *filename, struct rebase_options *opts)
  74{
  75        static struct strbuf path = STRBUF_INIT;
  76        static size_t prefix_len;
  77
  78        if (!prefix_len) {
  79                strbuf_addf(&path, "%s/", opts->state_dir);
  80                prefix_len = path.len;
  81        }
  82
  83        strbuf_setlen(&path, prefix_len);
  84        strbuf_addstr(&path, filename);
  85        return path.buf;
  86}
  87
  88static int finish_rebase(struct rebase_options *opts)
  89{
  90        struct strbuf dir = STRBUF_INIT;
  91        const char *argv_gc_auto[] = { "gc", "--auto", NULL };
  92
  93        delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
  94        apply_autostash();
  95        close_all_packs(the_repository->objects);
  96        /*
  97         * We ignore errors in 'gc --auto', since the
  98         * user should see them.
  99         */
 100        run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 101        strbuf_addstr(&dir, opts->state_dir);
 102        remove_dir_recursively(&dir, 0);
 103        strbuf_release(&dir);
 104
 105        return 0;
 106}
 107
 108static struct commit *peel_committish(const char *name)
 109{
 110        struct object *obj;
 111        struct object_id oid;
 112
 113        if (get_oid(name, &oid))
 114                return NULL;
 115        obj = parse_object(the_repository, &oid);
 116        return (struct commit *)peel_to_type(name, 0, obj, OBJ_COMMIT);
 117}
 118
 119static void add_var(struct strbuf *buf, const char *name, const char *value)
 120{
 121        if (!value)
 122                strbuf_addf(buf, "unset %s; ", name);
 123        else {
 124                strbuf_addf(buf, "%s=", name);
 125                sq_quote_buf(buf, value);
 126                strbuf_addstr(buf, "; ");
 127        }
 128}
 129
 130static int run_specific_rebase(struct rebase_options *opts)
 131{
 132        const char *argv[] = { NULL, NULL };
 133        struct strbuf script_snippet = STRBUF_INIT;
 134        int status;
 135        const char *backend, *backend_func;
 136
 137        add_var(&script_snippet, "GIT_DIR", absolute_path(get_git_dir()));
 138        add_var(&script_snippet, "state_dir", opts->state_dir);
 139
 140        add_var(&script_snippet, "upstream_name", opts->upstream_name);
 141        add_var(&script_snippet, "upstream",
 142                                 oid_to_hex(&opts->upstream->object.oid));
 143        add_var(&script_snippet, "head_name", opts->head_name);
 144        add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
 145        add_var(&script_snippet, "onto", oid_to_hex(&opts->onto->object.oid));
 146        add_var(&script_snippet, "onto_name", opts->onto_name);
 147        add_var(&script_snippet, "revisions", opts->revisions);
 148        add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
 149                oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
 150
 151        switch (opts->type) {
 152        case REBASE_AM:
 153                backend = "git-rebase--am";
 154                backend_func = "git_rebase__am";
 155                break;
 156        case REBASE_INTERACTIVE:
 157                backend = "git-rebase--interactive";
 158                backend_func = "git_rebase__interactive";
 159                break;
 160        case REBASE_MERGE:
 161                backend = "git-rebase--merge";
 162                backend_func = "git_rebase__merge";
 163                break;
 164        case REBASE_PRESERVE_MERGES:
 165                backend = "git-rebase--preserve-merges";
 166                backend_func = "git_rebase__preserve_merges";
 167                break;
 168        default:
 169                BUG("Unhandled rebase type %d", opts->type);
 170                break;
 171        }
 172
 173        strbuf_addf(&script_snippet,
 174                    ". git-sh-setup && . git-rebase--common &&"
 175                    " . %s && %s", backend, backend_func);
 176        argv[0] = script_snippet.buf;
 177
 178        status = run_command_v_opt(argv, RUN_USING_SHELL);
 179        if (opts->dont_finish_rebase)
 180                ; /* do nothing */
 181        else if (status == 0) {
 182                if (!file_exists(state_dir_path("stopped-sha", opts)))
 183                        finish_rebase(opts);
 184        } else if (status == 2) {
 185                struct strbuf dir = STRBUF_INIT;
 186
 187                apply_autostash();
 188                strbuf_addstr(&dir, opts->state_dir);
 189                remove_dir_recursively(&dir, 0);
 190                strbuf_release(&dir);
 191                die("Nothing to do");
 192        }
 193
 194        strbuf_release(&script_snippet);
 195
 196        return status ? -1 : 0;
 197}
 198
 199#define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
 200
 201static int reset_head(struct object_id *oid, const char *action,
 202                      const char *switch_to_branch, int detach_head)
 203{
 204        struct object_id head_oid;
 205        struct tree_desc desc;
 206        struct lock_file lock = LOCK_INIT;
 207        struct unpack_trees_options unpack_tree_opts;
 208        struct tree *tree;
 209        const char *reflog_action;
 210        struct strbuf msg = STRBUF_INIT;
 211        size_t prefix_len;
 212        struct object_id *orig = NULL, oid_orig,
 213                *old_orig = NULL, oid_old_orig;
 214        int ret = 0;
 215
 216        if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0)
 217                return -1;
 218
 219        if (!oid) {
 220                if (get_oid("HEAD", &head_oid)) {
 221                        rollback_lock_file(&lock);
 222                        return error(_("could not determine HEAD revision"));
 223                }
 224                oid = &head_oid;
 225        }
 226
 227        memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 228        setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 229        unpack_tree_opts.head_idx = 1;
 230        unpack_tree_opts.src_index = the_repository->index;
 231        unpack_tree_opts.dst_index = the_repository->index;
 232        unpack_tree_opts.fn = oneway_merge;
 233        unpack_tree_opts.update = 1;
 234        unpack_tree_opts.merge = 1;
 235        if (!detach_head)
 236                unpack_tree_opts.reset = 1;
 237
 238        if (read_index_unmerged(the_repository->index) < 0) {
 239                rollback_lock_file(&lock);
 240                return error(_("could not read index"));
 241        }
 242
 243        if (!fill_tree_descriptor(&desc, oid)) {
 244                error(_("failed to find tree of %s"), oid_to_hex(oid));
 245                rollback_lock_file(&lock);
 246                free((void *)desc.buffer);
 247                return -1;
 248        }
 249
 250        if (unpack_trees(1, &desc, &unpack_tree_opts)) {
 251                rollback_lock_file(&lock);
 252                free((void *)desc.buffer);
 253                return -1;
 254        }
 255
 256        tree = parse_tree_indirect(oid);
 257        prime_cache_tree(the_repository->index, tree);
 258
 259        if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0)
 260                ret = error(_("could not write index"));
 261        free((void *)desc.buffer);
 262
 263        if (ret)
 264                return ret;
 265
 266        reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
 267        strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
 268        prefix_len = msg.len;
 269
 270        if (!get_oid("ORIG_HEAD", &oid_old_orig))
 271                old_orig = &oid_old_orig;
 272        if (!get_oid("HEAD", &oid_orig)) {
 273                orig = &oid_orig;
 274                strbuf_addstr(&msg, "updating ORIG_HEAD");
 275                update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0,
 276                           UPDATE_REFS_MSG_ON_ERR);
 277        } else if (old_orig)
 278                delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
 279        strbuf_setlen(&msg, prefix_len);
 280        strbuf_addstr(&msg, "updating HEAD");
 281        if (!switch_to_branch)
 282                ret = update_ref(msg.buf, "HEAD", oid, orig, REF_NO_DEREF,
 283                                 UPDATE_REFS_MSG_ON_ERR);
 284        else {
 285                ret = create_symref("HEAD", switch_to_branch, msg.buf);
 286                if (!ret)
 287                        ret = update_ref(msg.buf, "HEAD", oid, NULL, 0,
 288                                         UPDATE_REFS_MSG_ON_ERR);
 289        }
 290
 291        strbuf_release(&msg);
 292        return ret;
 293}
 294
 295int cmd_rebase(int argc, const char **argv, const char *prefix)
 296{
 297        struct rebase_options options = {
 298                .type = REBASE_UNSPECIFIED,
 299        };
 300        const char *branch_name;
 301        int ret, flags;
 302        struct strbuf msg = STRBUF_INIT;
 303        struct strbuf revisions = STRBUF_INIT;
 304
 305        /*
 306         * NEEDSWORK: Once the builtin rebase has been tested enough
 307         * and git-legacy-rebase.sh is retired to contrib/, this preamble
 308         * can be removed.
 309         */
 310
 311        if (!use_builtin_rebase()) {
 312                const char *path = mkpath("%s/git-legacy-rebase",
 313                                          git_exec_path());
 314
 315                if (sane_execvp(path, (char **)argv) < 0)
 316                        die_errno(_("could not exec %s"), path);
 317                else
 318                        BUG("sane_execvp() returned???");
 319        }
 320
 321        if (argc != 2)
 322                die(_("Usage: %s <base>"), argv[0]);
 323        prefix = setup_git_directory();
 324        trace_repo_setup(prefix);
 325        setup_work_tree();
 326
 327        git_config(git_default_config, NULL);
 328
 329        switch (options.type) {
 330        case REBASE_MERGE:
 331        case REBASE_INTERACTIVE:
 332        case REBASE_PRESERVE_MERGES:
 333                options.state_dir = merge_dir();
 334                break;
 335        case REBASE_AM:
 336                options.state_dir = apply_dir();
 337                break;
 338        default:
 339                /* the default rebase backend is `--am` */
 340                options.type = REBASE_AM;
 341                options.state_dir = apply_dir();
 342                break;
 343        }
 344
 345        if (!options.root) {
 346                if (argc < 2)
 347                        die("TODO: handle @{upstream}");
 348                else {
 349                        options.upstream_name = argv[1];
 350                        argc--;
 351                        argv++;
 352                        if (!strcmp(options.upstream_name, "-"))
 353                                options.upstream_name = "@{-1}";
 354                }
 355                options.upstream = peel_committish(options.upstream_name);
 356                if (!options.upstream)
 357                        die(_("invalid upstream '%s'"), options.upstream_name);
 358        } else
 359                die("TODO: upstream for --root");
 360
 361        /* Make sure the branch to rebase onto is valid. */
 362        if (!options.onto_name)
 363                options.onto_name = options.upstream_name;
 364        if (strstr(options.onto_name, "...")) {
 365                die("TODO");
 366        } else {
 367                options.onto = peel_committish(options.onto_name);
 368                if (!options.onto)
 369                        die(_("Does not point to a valid commit '%s'"),
 370                                options.onto_name);
 371        }
 372
 373        /*
 374         * If the branch to rebase is given, that is the branch we will rebase
 375         * branch_name -- branch/commit being rebased, or
 376         *                HEAD (already detached)
 377         * orig_head -- commit object name of tip of the branch before rebasing
 378         * head_name -- refs/heads/<that-branch> or "detached HEAD"
 379         */
 380        if (argc > 1)
 381                 die("TODO: handle switch_to");
 382        else {
 383                /* Do not need to switch branches, we are already on it. */
 384                options.head_name =
 385                        xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
 386                                         &flags));
 387                if (!options.head_name)
 388                        die(_("No such ref: %s"), "HEAD");
 389                if (flags & REF_ISSYMREF) {
 390                        if (!skip_prefix(options.head_name,
 391                                         "refs/heads/", &branch_name))
 392                                branch_name = options.head_name;
 393
 394                } else {
 395                        options.head_name = xstrdup("detached HEAD");
 396                        branch_name = "HEAD";
 397                }
 398                if (get_oid("HEAD", &options.orig_head))
 399                        die(_("Could not resolve HEAD to a revision"));
 400        }
 401
 402        strbuf_addf(&msg, "rebase: checkout %s", options.onto_name);
 403        if (reset_head(&options.onto->object.oid, "checkout", NULL, 1))
 404                die(_("Could not detach HEAD"));
 405        strbuf_release(&msg);
 406
 407        strbuf_addf(&revisions, "%s..%s",
 408                    options.root ? oid_to_hex(&options.onto->object.oid) :
 409                    (options.restrict_revision ?
 410                     oid_to_hex(&options.restrict_revision->object.oid) :
 411                     oid_to_hex(&options.upstream->object.oid)),
 412                    oid_to_hex(&options.orig_head));
 413
 414        options.revisions = revisions.buf;
 415
 416        ret = !!run_specific_rebase(&options);
 417
 418        strbuf_release(&revisions);
 419        free(options.head_name);
 420        return ret;
 421}