git.oblomov.eu Git - git/blob - builtin/rebase.c

   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
  20 static GIT_PATH_FUNC(apply_dir, "rebase-apply")
  21 static GIT_PATH_FUNC(merge_dir, "rebase-merge")
  22
  23 enum rebase_type {
  24         REBASE_UNSPECIFIED = -1,
  25         REBASE_AM,
  26         REBASE_MERGE,
  27         REBASE_INTERACTIVE,
  28         REBASE_PRESERVE_MERGES
  29 };
  30
  31 static 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
  51 static int apply_autostash(void)
  52 {
  53         warning("TODO");
  54         return 0;
  55 }
  56
  57 struct 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 */
  73 static 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
  88 static 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
 108 static 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
 119 static 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
 130 static 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
 201 static 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
 295 int 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 }