diff options
Diffstat (limited to 'builtin-checkout.c')
| -rw-r--r-- | builtin-checkout.c | 577 |
1 files changed, 577 insertions, 0 deletions
diff --git a/builtin-checkout.c b/builtin-checkout.c new file mode 100644 index 0000000..7deb504 --- /dev/null +++ b/builtin-checkout.c @@ -0,0 +1,577 @@ +#include "cache.h" +#include "builtin.h" +#include "parse-options.h" +#include "refs.h" +#include "commit.h" +#include "tree.h" +#include "tree-walk.h" +#include "unpack-trees.h" +#include "dir.h" +#include "run-command.h" +#include "merge-recursive.h" +#include "branch.h" +#include "diff.h" +#include "revision.h" +#include "remote.h" + +static const char * const checkout_usage[] = { + "git checkout [options] <branch>", + "git checkout [options] [<branch>] -- <file>...", + NULL, +}; + +static int post_checkout_hook(struct commit *old, struct commit *new, + int changed) +{ + struct child_process proc; + const char *name = git_path("hooks/post-checkout"); + const char *argv[5]; + + if (access(name, X_OK) < 0) + return 0; + + memset(&proc, 0, sizeof(proc)); + argv[0] = name; + argv[1] = xstrdup(sha1_to_hex(old->object.sha1)); + argv[2] = xstrdup(sha1_to_hex(new->object.sha1)); + argv[3] = changed ? "1" : "0"; + argv[4] = NULL; + proc.argv = argv; + proc.no_stdin = 1; + proc.stdout_to_stderr = 1; + return run_command(&proc); +} + +static int update_some(const unsigned char *sha1, const char *base, int baselen, + const char *pathname, unsigned mode, int stage) +{ + int len; + struct cache_entry *ce; + + if (S_ISGITLINK(mode)) + return 0; + + if (S_ISDIR(mode)) + return READ_TREE_RECURSIVE; + + len = baselen + strlen(pathname); + ce = xcalloc(1, cache_entry_size(len)); + hashcpy(ce->sha1, sha1); + memcpy(ce->name, base, baselen); + memcpy(ce->name + baselen, pathname, len - baselen); + ce->ce_flags = create_ce_flags(len, 0); + ce->ce_mode = create_ce_mode(mode); + add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE); + return 0; +} + +static int read_tree_some(struct tree *tree, const char **pathspec) +{ + read_tree_recursive(tree, "", 0, 0, pathspec, update_some); + + /* update the index with the given tree's info + * for all args, expanding wildcards, and exit + * with any non-zero return code. + */ + return 0; +} + +static int checkout_paths(struct tree *source_tree, const char **pathspec) +{ + int pos; + struct checkout state; + static char *ps_matched; + unsigned char rev[20]; + int flag; + struct commit *head; + + int newfd; + struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file)); + + newfd = hold_locked_index(lock_file, 1); + read_cache(); + + if (source_tree) + read_tree_some(source_tree, pathspec); + + for (pos = 0; pathspec[pos]; pos++) + ; + ps_matched = xcalloc(1, pos); + + for (pos = 0; pos < active_nr; pos++) { + struct cache_entry *ce = active_cache[pos]; + pathspec_match(pathspec, ps_matched, ce->name, 0); + } + + if (report_path_error(ps_matched, pathspec, 0)) + return 1; + + memset(&state, 0, sizeof(state)); + state.force = 1; + state.refresh_cache = 1; + for (pos = 0; pos < active_nr; pos++) { + struct cache_entry *ce = active_cache[pos]; + if (pathspec_match(pathspec, NULL, ce->name, 0)) { + checkout_entry(ce, &state, NULL); + } + } + + if (write_cache(newfd, active_cache, active_nr) || + commit_locked_index(lock_file)) + die("unable to write new index file"); + + resolve_ref("HEAD", rev, 0, &flag); + head = lookup_commit_reference_gently(rev, 1); + + return post_checkout_hook(head, head, 0); +} + +static void show_local_changes(struct object *head) +{ + struct rev_info rev; + /* I think we want full paths, even if we're in a subdirectory. */ + init_revisions(&rev, NULL); + rev.abbrev = 0; + rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS; + add_pending_object(&rev, head, NULL); + run_diff_index(&rev, 0); +} + +static void describe_detached_head(char *msg, struct commit *commit) +{ + struct strbuf sb; + strbuf_init(&sb, 0); + parse_commit(commit); + pretty_print_commit(CMIT_FMT_ONELINE, commit, &sb, 0, "", "", 0, 0); + fprintf(stderr, "%s %s... %s\n", msg, + find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf); + strbuf_release(&sb); +} + +static int reset_to_new(struct tree *tree, int quiet) +{ + struct unpack_trees_options opts; + struct tree_desc tree_desc; + + memset(&opts, 0, sizeof(opts)); + opts.head_idx = -1; + opts.update = 1; + opts.reset = 1; + opts.merge = 1; + opts.fn = oneway_merge; + opts.verbose_update = !quiet; + opts.src_index = &the_index; + opts.dst_index = &the_index; + parse_tree(tree); + init_tree_desc(&tree_desc, tree->buffer, tree->size); + if (unpack_trees(1, &tree_desc, &opts)) + return 128; + return 0; +} + +static void reset_clean_to_new(struct tree *tree, int quiet) +{ + struct unpack_trees_options opts; + struct tree_desc tree_desc; + + memset(&opts, 0, sizeof(opts)); + opts.head_idx = -1; + opts.skip_unmerged = 1; + opts.reset = 1; + opts.merge = 1; + opts.fn = oneway_merge; + opts.verbose_update = !quiet; + opts.src_index = &the_index; + opts.dst_index = &the_index; + parse_tree(tree); + init_tree_desc(&tree_desc, tree->buffer, tree->size); + if (unpack_trees(1, &tree_desc, &opts)) + exit(128); +} + +struct checkout_opts { + int quiet; + int merge; + int force; + + char *new_branch; + int new_branch_log; + enum branch_track track; +}; + +struct branch_info { + const char *name; /* The short name used */ + const char *path; /* The full name of a real branch */ + struct commit *commit; /* The named commit */ +}; + +static void setup_branch_path(struct branch_info *branch) +{ + struct strbuf buf; + strbuf_init(&buf, 0); + strbuf_addstr(&buf, "refs/heads/"); + strbuf_addstr(&buf, branch->name); + branch->path = strbuf_detach(&buf, NULL); +} + +static int merge_working_tree(struct checkout_opts *opts, + struct branch_info *old, struct branch_info *new) +{ + int ret; + struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file)); + int newfd = hold_locked_index(lock_file, 1); + read_cache(); + + if (opts->force) { + ret = reset_to_new(new->commit->tree, opts->quiet); + if (ret) + return ret; + } else { + struct tree_desc trees[2]; + struct tree *tree; + struct unpack_trees_options topts; + + memset(&topts, 0, sizeof(topts)); + topts.head_idx = -1; + topts.src_index = &the_index; + topts.dst_index = &the_index; + + refresh_cache(REFRESH_QUIET); + + if (unmerged_cache()) { + error("you need to resolve your current index first"); + return 1; + } + + /* 2-way merge to the new branch */ + topts.update = 1; + topts.merge = 1; + topts.gently = opts->merge; + topts.verbose_update = !opts->quiet; + topts.fn = twoway_merge; + topts.dir = xcalloc(1, sizeof(*topts.dir)); + topts.dir->show_ignored = 1; + topts.dir->exclude_per_dir = ".gitignore"; + tree = parse_tree_indirect(old->commit->object.sha1); + init_tree_desc(&trees[0], tree->buffer, tree->size); + tree = parse_tree_indirect(new->commit->object.sha1); + init_tree_desc(&trees[1], tree->buffer, tree->size); + + if (unpack_trees(2, trees, &topts)) { + /* + * Unpack couldn't do a trivial merge; either + * give up or do a real merge, depending on + * whether the merge flag was used. + */ + struct tree *result; + struct tree *work; + if (!opts->merge) + return 1; + parse_commit(old->commit); + + /* Do more real merge */ + + /* + * We update the index fully, then write the + * tree from the index, then merge the new + * branch with the current tree, with the old + * branch as the base. Then we reset the index + * (but not the working tree) to the new + * branch, leaving the working tree as the + * merged version, but skipping unmerged + * entries in the index. + */ + + add_files_to_cache(0, NULL, NULL); + work = write_tree_from_memory(); + + ret = reset_to_new(new->commit->tree, opts->quiet); + if (ret) + return ret; + merge_trees(new->commit->tree, work, old->commit->tree, + new->name, "local", &result); + reset_clean_to_new(new->commit->tree, opts->quiet); + } + } + + if (write_cache(newfd, active_cache, active_nr) || + commit_locked_index(lock_file)) + die("unable to write new index file"); + + if (!opts->force) + show_local_changes(&new->commit->object); + + return 0; +} + +static void report_tracking(struct branch_info *new, struct checkout_opts *opts) +{ + /* + * We have switched to a new branch; is it building on + * top of another branch, and if so does that other branch + * have changes we do not have yet? + */ + char *base; + unsigned char sha1[20]; + struct commit *ours, *theirs; + char symmetric[84]; + struct rev_info revs; + const char *rev_argv[10]; + int rev_argc; + int num_ours, num_theirs; + const char *remote_msg; + struct branch *branch = branch_get(new->name); + + /* + * Nothing to report unless we are marked to build on top of + * somebody else. + */ + if (!branch || !branch->merge || !branch->merge[0] || !branch->merge[0]->dst) + return; + + /* + * If what we used to build on no longer exists, there is + * nothing to report. + */ + base = branch->merge[0]->dst; + if (!resolve_ref(base, sha1, 1, NULL)) + return; + + theirs = lookup_commit(sha1); + ours = new->commit; + if (!hashcmp(sha1, ours->object.sha1)) + return; /* we are the same */ + + /* Run "rev-list --left-right ours...theirs" internally... */ + rev_argc = 0; + rev_argv[rev_argc++] = NULL; + rev_argv[rev_argc++] = "--left-right"; + rev_argv[rev_argc++] = symmetric; + rev_argv[rev_argc++] = "--"; + rev_argv[rev_argc] = NULL; + + strcpy(symmetric, sha1_to_hex(ours->object.sha1)); + strcpy(symmetric + 40, "..."); + strcpy(symmetric + 43, sha1_to_hex(theirs->object.sha1)); + + init_revisions(&revs, NULL); + setup_revisions(rev_argc, rev_argv, &revs, NULL); + prepare_revision_walk(&revs); + + /* ... and count the commits on each side. */ + num_ours = 0; + num_theirs = 0; + while (1) { + struct commit *c = get_revision(&revs); + if (!c) + break; + if (c->object.flags & SYMMETRIC_LEFT) + num_ours++; + else + num_theirs++; + } + + if (!prefixcmp(base, "refs/remotes/")) { + remote_msg = " remote"; + base += strlen("refs/remotes/"); + } else { + remote_msg = ""; + } + + if (!num_theirs) + printf("Your branch is ahead of the tracked%s branch '%s' " + "by %d commit%s.\n", + remote_msg, base, + num_ours, (num_ours == 1) ? "" : "s"); + else if (!num_ours) + printf("Your branch is behind the tracked%s branch '%s' " + "by %d commit%s,\n" + "and can be fast-forwarded.\n", + remote_msg, base, + num_theirs, (num_theirs == 1) ? "" : "s"); + else + printf("Your branch and the tracked%s branch '%s' " + "have diverged,\nand respectively " + "have %d and %d different commit(s) each.\n", + remote_msg, base, + num_ours, num_theirs); +} + +static void update_refs_for_switch(struct checkout_opts *opts, + struct branch_info *old, + struct branch_info *new) +{ + struct strbuf msg; + const char *old_desc; + if (opts->new_branch) { + create_branch(old->name, opts->new_branch, new->name, 0, + opts->new_branch_log, opts->track); + new->name = opts->new_branch; + setup_branch_path(new); + } + + strbuf_init(&msg, 0); + old_desc = old->name; + if (!old_desc) + old_desc = sha1_to_hex(old->commit->object.sha1); + strbuf_addf(&msg, "checkout: moving from %s to %s", + old_desc, new->name); + + if (new->path) { + create_symref("HEAD", new->path, msg.buf); + if (!opts->quiet) { + if (old->path && !strcmp(new->path, old->path)) + fprintf(stderr, "Already on \"%s\"\n", + new->name); + else + fprintf(stderr, "Switched to%s branch \"%s\"\n", + opts->new_branch ? " a new" : "", + new->name); + } + } else if (strcmp(new->name, "HEAD")) { + update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL, + REF_NODEREF, DIE_ON_ERR); + if (!opts->quiet) { + if (old->path) + fprintf(stderr, "Note: moving to \"%s\" which isn't a local branch\nIf you want to create a new branch from this checkout, you may do so\n(now or later) by using -b with the checkout command again. Example:\n git checkout -b <new_branch_name>\n", new->name); + describe_detached_head("HEAD is now at", new->commit); + } + } + remove_branch_state(); + strbuf_release(&msg); + if (!opts->quiet && (new->path || !strcmp(new->name, "HEAD"))) + report_tracking(new, opts); +} + +static int switch_branches(struct checkout_opts *opts, struct branch_info *new) +{ + int ret = 0; + struct branch_info old; + unsigned char rev[20]; + int flag; + memset(&old, 0, sizeof(old)); + old.path = resolve_ref("HEAD", rev, 0, &flag); + old.commit = lookup_commit_reference_gently(rev, 1); + if (!(flag & REF_ISSYMREF)) + old.path = NULL; + + if (old.path && !prefixcmp(old.path, "refs/heads/")) + old.name = old.path + strlen("refs/heads/"); + + if (!new->name) { + new->name = "HEAD"; + new->commit = old.commit; + if (!new->commit) + die("You are on a branch yet to be born"); + parse_commit(new->commit); + } + + /* + * If the new thing isn't a branch and isn't HEAD and we're + * not starting a new branch, and we want messages, and we + * weren't on a branch, and we're moving to a new commit, + * describe the old commit. + */ + if (!new->path && strcmp(new->name, "HEAD") && !opts->new_branch && + !opts->quiet && !old.path && new->commit != old.commit) + describe_detached_head("Previous HEAD position was", old.commit); + + if (!old.commit) { + if (!opts->quiet) { + fprintf(stderr, "warning: You appear to be on a branch yet to be born.\n"); + fprintf(stderr, "warning: Forcing checkout of %s.\n", new->name); + } + opts->force = 1; + } + + ret = merge_working_tree(opts, &old, new); + if (ret) + return ret; + + update_refs_for_switch(opts, &old, new); + + return post_checkout_hook(old.commit, new->commit, 1); +} + +int cmd_checkout(int argc, const char **argv, const char *prefix) +{ + struct checkout_opts opts; + unsigned char rev[20]; + const char *arg; + struct branch_info new; + struct tree *source_tree = NULL; + struct option options[] = { + OPT__QUIET(&opts.quiet), + OPT_STRING('b', NULL, &opts.new_branch, "new branch", "branch"), + OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "log for new branch"), + OPT_SET_INT( 0 , "track", &opts.track, "track", + BRANCH_TRACK_EXPLICIT), + OPT_BOOLEAN('f', NULL, &opts.force, "force"), + OPT_BOOLEAN('m', NULL, &opts.merge, "merge"), + OPT_END(), + }; + + memset(&opts, 0, sizeof(opts)); + memset(&new, 0, sizeof(new)); + + git_config(git_default_config); + + opts.track = git_branch_track; + + argc = parse_options(argc, argv, options, checkout_usage, 0); + if (argc) { + arg = argv[0]; + if (get_sha1(arg, rev)) + ; + else if ((new.commit = lookup_commit_reference_gently(rev, 1))) { + new.name = arg; + setup_branch_path(&new); + if (resolve_ref(new.path, rev, 1, NULL)) + new.commit = lookup_commit_reference(rev); + else + new.path = NULL; + parse_commit(new.commit); + source_tree = new.commit->tree; + argv++; + argc--; + } else if ((source_tree = parse_tree_indirect(rev))) { + argv++; + argc--; + } + } + + if (argc && !strcmp(argv[0], "--")) { + argv++; + argc--; + } + + if (!opts.new_branch && (opts.track != git_branch_track)) + die("git checkout: --track and --no-track require -b"); + + if (opts.force && opts.merge) + die("git checkout: -f and -m are incompatible"); + + if (argc) { + const char **pathspec = get_pathspec(prefix, argv); + + if (!pathspec) + die("invalid path specification"); + + /* Checkout paths */ + if (opts.new_branch || opts.force || opts.merge) { + if (argc == 1) { + die("git checkout: updating paths is incompatible with switching branches/forcing\nDid you intend to checkout '%s' which can not be resolved as commit?", argv[0]); + } else { + die("git checkout: updating paths is incompatible with switching branches/forcing"); + } + } + + return checkout_paths(source_tree, pathspec); + } + + if (new.name && !new.commit) { + die("Cannot switch branch to a non-commit."); + } + + return switch_branches(&opts, &new); +} |