Merge branch 'pk/rebase-in-c-2-basic'
Rewrite "git rebase" in C.
* pk/rebase-in-c-2-basic:
builtin rebase: support `git rebase <upstream> <switch-to>`
builtin rebase: only store fully-qualified refs in `options.head_name`
builtin rebase: start a new rebase only if none is in progress
builtin rebase: support --force-rebase
builtin rebase: try to fast forward when possible
builtin rebase: require a clean worktree
builtin rebase: support the `verbose` and `diffstat` options
builtin rebase: support --quiet
builtin rebase: handle the pre-rebase hook and --no-verify
builtin rebase: support `git rebase --onto A...B`
builtin rebase: support --onto
diff --git a/builtin/rebase.c b/builtin/rebase.c
index e695d8a..71367c8 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -16,6 +16,21 @@
#include "cache-tree.h"
#include "unpack-trees.h"
#include "lockfile.h"
+#include "parse-options.h"
+#include "commit.h"
+#include "diff.h"
+#include "wt-status.h"
+#include "revision.h"
+#include "commit-reach.h"
+
+static char const * const builtin_rebase_usage[] = {
+ N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
+ "[<upstream>] [<branch>]"),
+ N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "
+ "--root [<branch>]"),
+ N_("git rebase --continue | --abort | --skip | --edit-todo"),
+ NULL
+};
static GIT_PATH_FUNC(apply_dir, "rebase-apply")
static GIT_PATH_FUNC(merge_dir, "rebase-merge")
@@ -59,16 +74,32 @@ struct rebase_options {
const char *state_dir;
struct commit *upstream;
const char *upstream_name;
+ const char *upstream_arg;
char *head_name;
struct object_id orig_head;
struct commit *onto;
const char *onto_name;
const char *revisions;
+ const char *switch_to;
int root;
struct commit *restrict_revision;
int dont_finish_rebase;
+ enum {
+ REBASE_NO_QUIET = 1<<0,
+ REBASE_VERBOSE = 1<<1,
+ REBASE_DIFFSTAT = 1<<2,
+ REBASE_FORCE = 1<<3,
+ REBASE_INTERACTIVE_EXPLICIT = 1<<4,
+ } flags;
+ struct strbuf git_am_opt;
};
+static int is_interactive(struct rebase_options *opts)
+{
+ return opts->type == REBASE_INTERACTIVE ||
+ opts->type == REBASE_PRESERVE_MERGES;
+}
+
/* Returns the filename prefixed by the state_dir */
static const char *state_dir_path(const char *filename, struct rebase_options *opts)
{
@@ -140,13 +171,25 @@ static int run_specific_rebase(struct rebase_options *opts)
add_var(&script_snippet, "upstream_name", opts->upstream_name);
add_var(&script_snippet, "upstream",
oid_to_hex(&opts->upstream->object.oid));
- add_var(&script_snippet, "head_name", opts->head_name);
+ add_var(&script_snippet, "head_name",
+ opts->head_name ? opts->head_name : "detached HEAD");
add_var(&script_snippet, "orig_head", oid_to_hex(&opts->orig_head));
add_var(&script_snippet, "onto", oid_to_hex(&opts->onto->object.oid));
add_var(&script_snippet, "onto_name", opts->onto_name);
add_var(&script_snippet, "revisions", opts->revisions);
add_var(&script_snippet, "restrict_revision", opts->restrict_revision ?
oid_to_hex(&opts->restrict_revision->object.oid) : NULL);
+ add_var(&script_snippet, "GIT_QUIET",
+ opts->flags & REBASE_NO_QUIET ? "" : "t");
+ add_var(&script_snippet, "git_am_opt", opts->git_am_opt.buf);
+ add_var(&script_snippet, "verbose",
+ opts->flags & REBASE_VERBOSE ? "t" : "");
+ add_var(&script_snippet, "diffstat",
+ opts->flags & REBASE_DIFFSTAT ? "t" : "");
+ add_var(&script_snippet, "force_rebase",
+ opts->flags & REBASE_FORCE ? "t" : "");
+ if (opts->switch_to)
+ add_var(&script_snippet, "switch_to", opts->switch_to);
switch (opts->type) {
case REBASE_AM:
@@ -213,6 +256,9 @@ static int reset_head(struct object_id *oid, const char *action,
*old_orig = NULL, oid_old_orig;
int ret = 0;
+ if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
+ BUG("Not a fully qualified branch: '%s'", switch_to_branch);
+
if (hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0)
return -1;
@@ -292,15 +338,98 @@ static int reset_head(struct object_id *oid, const char *action,
return ret;
}
+static int rebase_config(const char *var, const char *value, void *data)
+{
+ struct rebase_options *opts = data;
+
+ if (!strcmp(var, "rebase.stat")) {
+ if (git_config_bool(var, value))
+ opts->flags |= REBASE_DIFFSTAT;
+ else
+ opts->flags &= !REBASE_DIFFSTAT;
+ return 0;
+ }
+
+ return git_default_config(var, value, data);
+}
+
+/*
+ * Determines whether the commits in from..to are linear, i.e. contain
+ * no merge commits. This function *expects* `from` to be an ancestor of
+ * `to`.
+ */
+static int is_linear_history(struct commit *from, struct commit *to)
+{
+ while (to && to != from) {
+ parse_commit(to);
+ if (!to->parents)
+ return 1;
+ if (to->parents->next)
+ return 0;
+ to = to->parents->item;
+ }
+ return 1;
+}
+
+static int can_fast_forward(struct commit *onto, struct object_id *head_oid,
+ struct object_id *merge_base)
+{
+ struct commit *head = lookup_commit(the_repository, head_oid);
+ struct commit_list *merge_bases;
+ int res;
+
+ if (!head)
+ return 0;
+
+ merge_bases = get_merge_bases(onto, head);
+ if (merge_bases && !merge_bases->next) {
+ oidcpy(merge_base, &merge_bases->item->object.oid);
+ res = !oidcmp(merge_base, &onto->object.oid);
+ } else {
+ oidcpy(merge_base, &null_oid);
+ res = 0;
+ }
+ free_commit_list(merge_bases);
+ return res && is_linear_history(onto, head);
+}
+
int cmd_rebase(int argc, const char **argv, const char *prefix)
{
struct rebase_options options = {
.type = REBASE_UNSPECIFIED,
+ .flags = REBASE_NO_QUIET,
+ .git_am_opt = STRBUF_INIT,
};
const char *branch_name;
- int ret, flags;
+ int ret, flags, in_progress = 0;
+ int ok_to_skip_pre_rebase = 0;
struct strbuf msg = STRBUF_INIT;
struct strbuf revisions = STRBUF_INIT;
+ struct strbuf buf = STRBUF_INIT;
+ struct object_id merge_base;
+ struct option builtin_rebase_options[] = {
+ OPT_STRING(0, "onto", &options.onto_name,
+ N_("revision"),
+ N_("rebase onto given branch instead of upstream")),
+ OPT_BOOL(0, "no-verify", &ok_to_skip_pre_rebase,
+ N_("allow pre-rebase hook to run")),
+ OPT_NEGBIT('q', "quiet", &options.flags,
+ N_("be quiet. implies --no-stat"),
+ REBASE_NO_QUIET| REBASE_VERBOSE | REBASE_DIFFSTAT),
+ OPT_BIT('v', "verbose", &options.flags,
+ N_("display a diffstat of what changed upstream"),
+ REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
+ {OPTION_NEGBIT, 'n', "no-stat", &options.flags, NULL,
+ N_("do not show diffstat of what changed upstream"),
+ PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
+ OPT_BIT('f', "force-rebase", &options.flags,
+ N_("cherry-pick all commits, even if unchanged"),
+ REBASE_FORCE),
+ OPT_BIT(0, "no-ff", &options.flags,
+ N_("cherry-pick all commits, even if unchanged"),
+ REBASE_FORCE),
+ OPT_END(),
+ };
/*
* NEEDSWORK: Once the builtin rebase has been tested enough
@@ -318,13 +447,70 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
BUG("sane_execvp() returned???");
}
- if (argc != 2)
- die(_("Usage: %s <base>"), argv[0]);
+ if (argc == 2 && !strcmp(argv[1], "-h"))
+ usage_with_options(builtin_rebase_usage,
+ builtin_rebase_options);
+
prefix = setup_git_directory();
trace_repo_setup(prefix);
setup_work_tree();
- git_config(git_default_config, NULL);
+ git_config(rebase_config, &options);
+
+ if (is_directory(apply_dir())) {
+ options.type = REBASE_AM;
+ options.state_dir = apply_dir();
+ } else if (is_directory(merge_dir())) {
+ strbuf_reset(&buf);
+ strbuf_addf(&buf, "%s/rewritten", merge_dir());
+ if (is_directory(buf.buf)) {
+ options.type = REBASE_PRESERVE_MERGES;
+ options.flags |= REBASE_INTERACTIVE_EXPLICIT;
+ } else {
+ strbuf_reset(&buf);
+ strbuf_addf(&buf, "%s/interactive", merge_dir());
+ if(file_exists(buf.buf)) {
+ options.type = REBASE_INTERACTIVE;
+ options.flags |= REBASE_INTERACTIVE_EXPLICIT;
+ } else
+ options.type = REBASE_MERGE;
+ }
+ options.state_dir = merge_dir();
+ }
+
+ if (options.type != REBASE_UNSPECIFIED)
+ in_progress = 1;
+
+ argc = parse_options(argc, argv, prefix,
+ builtin_rebase_options,
+ builtin_rebase_usage, 0);
+
+ if (argc > 2)
+ usage_with_options(builtin_rebase_usage,
+ builtin_rebase_options);
+
+ /* Make sure no rebase is in progress */
+ if (in_progress) {
+ const char *last_slash = strrchr(options.state_dir, '/');
+ const char *state_dir_base =
+ last_slash ? last_slash + 1 : options.state_dir;
+ const char *cmd_live_rebase =
+ "git rebase (--continue | --abort | --skip)";
+ strbuf_reset(&buf);
+ strbuf_addf(&buf, "rm -fr \"%s\"", options.state_dir);
+ die(_("It seems that there is already a %s directory, and\n"
+ "I wonder if you are in the middle of another rebase. "
+ "If that is the\n"
+ "case, please try\n\t%s\n"
+ "If that is not the case, please\n\t%s\n"
+ "and run me again. I am stopping in case you still "
+ "have something\n"
+ "valuable there.\n"),
+ state_dir_base, cmd_live_rebase, buf.buf);
+ }
+
+ if (!(options.flags & REBASE_NO_QUIET))
+ strbuf_addstr(&options.git_am_opt, " -q");
switch (options.type) {
case REBASE_MERGE:
@@ -343,10 +529,10 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
}
if (!options.root) {
- if (argc < 2)
+ if (argc < 1)
die("TODO: handle @{upstream}");
else {
- options.upstream_name = argv[1];
+ options.upstream_name = argv[0];
argc--;
argv++;
if (!strcmp(options.upstream_name, "-"))
@@ -355,6 +541,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
options.upstream = peel_committish(options.upstream_name);
if (!options.upstream)
die(_("invalid upstream '%s'"), options.upstream_name);
+ options.upstream_arg = options.upstream_name;
} else
die("TODO: upstream for --root");
@@ -362,7 +549,11 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
if (!options.onto_name)
options.onto_name = options.upstream_name;
if (strstr(options.onto_name, "...")) {
- die("TODO");
+ if (get_oid_mb(options.onto_name, &merge_base) < 0)
+ die(_("'%s': need exactly one merge base"),
+ options.onto_name);
+ options.onto = lookup_commit_or_die(&merge_base,
+ options.onto_name);
} else {
options.onto = peel_committish(options.onto_name);
if (!options.onto)
@@ -375,11 +566,25 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
* branch_name -- branch/commit being rebased, or
* HEAD (already detached)
* orig_head -- commit object name of tip of the branch before rebasing
- * head_name -- refs/heads/<that-branch> or "detached HEAD"
+ * head_name -- refs/heads/<that-branch> or NULL (detached HEAD)
*/
- if (argc > 1)
- die("TODO: handle switch_to");
- else {
+ if (argc == 1) {
+ /* Is it "rebase other branchname" or "rebase other commit"? */
+ branch_name = argv[0];
+ options.switch_to = argv[0];
+
+ /* Is it a local branch? */
+ strbuf_reset(&buf);
+ strbuf_addf(&buf, "refs/heads/%s", branch_name);
+ if (!read_ref(buf.buf, &options.orig_head))
+ options.head_name = xstrdup(buf.buf);
+ /* If not is it a valid ref (branch or commit)? */
+ else if (!get_oid(branch_name, &options.orig_head))
+ options.head_name = NULL;
+ else
+ die(_("fatal: no such branch/commit '%s'"),
+ branch_name);
+ } else if (argc == 0) {
/* Do not need to switch branches, we are already on it. */
options.head_name =
xstrdup_or_null(resolve_ref_unsafe("HEAD", 0, NULL,
@@ -392,13 +597,115 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
branch_name = options.head_name;
} else {
- options.head_name = xstrdup("detached HEAD");
+ free(options.head_name);
+ options.head_name = NULL;
branch_name = "HEAD";
}
if (get_oid("HEAD", &options.orig_head))
die(_("Could not resolve HEAD to a revision"));
+ } else
+ BUG("unexpected number of arguments left to parse");
+
+ if (read_index(the_repository->index) < 0)
+ die(_("could not read index"));
+
+ if (require_clean_work_tree("rebase",
+ _("Please commit or stash them."), 1, 1)) {
+ ret = 1;
+ goto cleanup;
}
+ /*
+ * Now we are rebasing commits upstream..orig_head (or with --root,
+ * everything leading up to orig_head) on top of onto.
+ */
+
+ /*
+ * Check if we are already based on onto with linear history,
+ * but this should be done only when upstream and onto are the same
+ * and if this is not an interactive rebase.
+ */
+ if (can_fast_forward(options.onto, &options.orig_head, &merge_base) &&
+ !is_interactive(&options) && !options.restrict_revision &&
+ !oidcmp(&options.upstream->object.oid, &options.onto->object.oid)) {
+ int flag;
+
+ if (!(options.flags & REBASE_FORCE)) {
+ /* Lazily switch to the target branch if needed... */
+ if (options.switch_to) {
+ struct object_id oid;
+
+ if (get_oid(options.switch_to, &oid) < 0) {
+ ret = !!error(_("could not parse '%s'"),
+ options.switch_to);
+ goto cleanup;
+ }
+
+ strbuf_reset(&buf);
+ strbuf_addf(&buf, "rebase: checkout %s",
+ options.switch_to);
+ if (reset_head(&oid, "checkout",
+ options.head_name, 0) < 0) {
+ ret = !!error(_("could not switch to "
+ "%s"),
+ options.switch_to);
+ goto cleanup;
+ }
+ }
+
+ if (!(options.flags & REBASE_NO_QUIET))
+ ; /* be quiet */
+ else if (!strcmp(branch_name, "HEAD") &&
+ resolve_ref_unsafe("HEAD", 0, NULL, &flag))
+ puts(_("HEAD is up to date."));
+ else
+ printf(_("Current branch %s is up to date.\n"),
+ branch_name);
+ ret = !!finish_rebase(&options);
+ goto cleanup;
+ } else if (!(options.flags & REBASE_NO_QUIET))
+ ; /* be quiet */
+ else if (!strcmp(branch_name, "HEAD") &&
+ resolve_ref_unsafe("HEAD", 0, NULL, &flag))
+ puts(_("HEAD is up to date, rebase forced."));
+ else
+ printf(_("Current branch %s is up to date, rebase "
+ "forced.\n"), branch_name);
+ }
+
+ /* If a hook exists, give it a chance to interrupt*/
+ if (!ok_to_skip_pre_rebase &&
+ run_hook_le(NULL, "pre-rebase", options.upstream_arg,
+ argc ? argv[0] : NULL, NULL))
+ die(_("The pre-rebase hook refused to rebase."));
+
+ if (options.flags & REBASE_DIFFSTAT) {
+ struct diff_options opts;
+
+ if (options.flags & REBASE_VERBOSE)
+ printf(_("Changes from %s to %s:\n"),
+ oid_to_hex(&merge_base),
+ oid_to_hex(&options.onto->object.oid));
+
+ /* We want color (if set), but no pager */
+ diff_setup(&opts);
+ opts.stat_width = -1; /* use full terminal width */
+ opts.stat_graph_width = -1; /* respect statGraphWidth config */
+ opts.output_format |=
+ DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
+ opts.detect_rename = DIFF_DETECT_RENAME;
+ diff_setup_done(&opts);
+ diff_tree_oid(&merge_base, &options.onto->object.oid,
+ "", &opts);
+ diffcore_std(&opts);
+ diff_flush(&opts);
+ }
+
+ /* Detach HEAD and reset the tree */
+ if (options.flags & REBASE_NO_QUIET)
+ printf(_("First, rewinding head to replay your work on top of "
+ "it...\n"));
+
strbuf_addf(&msg, "rebase: checkout %s", options.onto_name);
if (reset_head(&options.onto->object.oid, "checkout", NULL, 1))
die(_("Could not detach HEAD"));
@@ -415,6 +722,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
ret = !!run_specific_rebase(&options);
+cleanup:
strbuf_release(&revisions);
free(options.head_name);
return ret;
