git/builtin/revert.c

611 строки
15 KiB
C

#include "cache.h"
#include "builtin.h"
#include "object.h"
#include "commit.h"
#include "tag.h"
#include "wt-status.h"
#include "run-command.h"
#include "exec_cmd.h"
#include "utf8.h"
#include "parse-options.h"
#include "cache-tree.h"
#include "diff.h"
#include "revision.h"
#include "rerere.h"
#include "merge-recursive.h"
#include "refs.h"
/*
* This implements the builtins revert and cherry-pick.
*
* Copyright (c) 2007 Johannes E. Schindelin
*
* Based on git-revert.sh, which is
*
* Copyright (c) 2005 Linus Torvalds
* Copyright (c) 2005 Junio C Hamano
*/
static const char * const revert_usage[] = {
"git revert [options] <commit-ish>",
NULL
};
static const char * const cherry_pick_usage[] = {
"git cherry-pick [options] <commit-ish>",
NULL
};
static int edit, no_replay, no_commit, mainline, signoff, allow_ff;
static enum { REVERT, CHERRY_PICK } action;
static struct commit *commit;
static int commit_argc;
static const char **commit_argv;
static int allow_rerere_auto;
static const char *me;
static const char *strategy;
#define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
static char *get_encoding(const char *message);
static const char * const *revert_or_cherry_pick_usage(void)
{
return action == REVERT ? revert_usage : cherry_pick_usage;
}
static void parse_args(int argc, const char **argv)
{
const char * const * usage_str = revert_or_cherry_pick_usage();
int noop;
struct option options[] = {
OPT_BOOLEAN('n', "no-commit", &no_commit, "don't automatically commit"),
OPT_BOOLEAN('e', "edit", &edit, "edit the commit message"),
OPT_BOOLEAN('r', NULL, &noop, "no-op (backward compatibility)"),
OPT_BOOLEAN('s', "signoff", &signoff, "add Signed-off-by:"),
OPT_INTEGER('m', "mainline", &mainline, "parent number"),
OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
OPT_STRING(0, "strategy", &strategy, "strategy", "merge strategy"),
OPT_END(),
OPT_END(),
OPT_END(),
};
if (action == CHERRY_PICK) {
struct option cp_extra[] = {
OPT_BOOLEAN('x', NULL, &no_replay, "append commit name"),
OPT_BOOLEAN(0, "ff", &allow_ff, "allow fast-forward"),
OPT_END(),
};
if (parse_options_concat(options, ARRAY_SIZE(options), cp_extra))
die("program error");
}
commit_argc = parse_options(argc, argv, NULL, options, usage_str,
PARSE_OPT_KEEP_ARGV0 |
PARSE_OPT_KEEP_UNKNOWN);
if (commit_argc < 2)
usage_with_options(usage_str, options);
commit_argv = argv;
}
struct commit_message {
char *parent_label;
const char *label;
const char *subject;
char *reencoded_message;
const char *message;
};
static int get_message(const char *raw_message, struct commit_message *out)
{
const char *encoding;
const char *abbrev, *subject;
int abbrev_len, subject_len;
char *q;
if (!raw_message)
return -1;
encoding = get_encoding(raw_message);
if (!encoding)
encoding = "UTF-8";
if (!git_commit_encoding)
git_commit_encoding = "UTF-8";
out->reencoded_message = NULL;
out->message = raw_message;
if (strcmp(encoding, git_commit_encoding))
out->reencoded_message = reencode_string(raw_message,
git_commit_encoding, encoding);
if (out->reencoded_message)
out->message = out->reencoded_message;
abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
abbrev_len = strlen(abbrev);
subject_len = find_commit_subject(out->message, &subject);
out->parent_label = xmalloc(strlen("parent of ") + abbrev_len +
strlen("... ") + subject_len + 1);
q = out->parent_label;
q = mempcpy(q, "parent of ", strlen("parent of "));
out->label = q;
q = mempcpy(q, abbrev, abbrev_len);
q = mempcpy(q, "... ", strlen("... "));
out->subject = q;
q = mempcpy(q, subject, subject_len);
*q = '\0';
return 0;
}
static void free_message(struct commit_message *msg)
{
free(msg->parent_label);
free(msg->reencoded_message);
}
static char *get_encoding(const char *message)
{
const char *p = message, *eol;
if (!p)
die ("Could not read commit message of %s",
sha1_to_hex(commit->object.sha1));
while (*p && *p != '\n') {
for (eol = p + 1; *eol && *eol != '\n'; eol++)
; /* do nothing */
if (!prefixcmp(p, "encoding ")) {
char *result = xmalloc(eol - 8 - p);
strlcpy(result, p + 9, eol - 8 - p);
return result;
}
p = eol;
if (*p == '\n')
p++;
}
return NULL;
}
static void add_message_to_msg(struct strbuf *msgbuf, const char *message)
{
const char *p = message;
while (*p && (*p != '\n' || p[1] != '\n'))
p++;
if (!*p)
strbuf_addstr(msgbuf, sha1_to_hex(commit->object.sha1));
p += 2;
strbuf_addstr(msgbuf, p);
}
static void set_author_ident_env(const char *message)
{
const char *p = message;
if (!p)
die ("Could not read commit message of %s",
sha1_to_hex(commit->object.sha1));
while (*p && *p != '\n') {
const char *eol;
for (eol = p; *eol && *eol != '\n'; eol++)
; /* do nothing */
if (!prefixcmp(p, "author ")) {
char *line, *pend, *email, *timestamp;
p += 7;
line = xmemdupz(p, eol - p);
email = strchr(line, '<');
if (!email)
die ("Could not extract author email from %s",
sha1_to_hex(commit->object.sha1));
if (email == line)
pend = line;
else
for (pend = email; pend != line + 1 &&
isspace(pend[-1]); pend--);
; /* do nothing */
*pend = '\0';
email++;
timestamp = strchr(email, '>');
if (!timestamp)
die ("Could not extract author time from %s",
sha1_to_hex(commit->object.sha1));
*timestamp = '\0';
for (timestamp++; *timestamp && isspace(*timestamp);
timestamp++)
; /* do nothing */
setenv("GIT_AUTHOR_NAME", line, 1);
setenv("GIT_AUTHOR_EMAIL", email, 1);
setenv("GIT_AUTHOR_DATE", timestamp, 1);
free(line);
return;
}
p = eol;
if (*p == '\n')
p++;
}
die ("No author information found in %s",
sha1_to_hex(commit->object.sha1));
}
static void advise(const char *advice, ...)
{
va_list params;
va_start(params, advice);
vreportf("hint: ", advice, params);
va_end(params);
}
static void print_advice(void)
{
char *msg = getenv("GIT_CHERRY_PICK_HELP");
if (msg) {
fprintf(stderr, "%s\n", msg);
return;
}
advise("after resolving the conflicts, mark the corrected paths");
advise("with 'git add <paths>' or 'git rm <paths>'");
if (action == CHERRY_PICK)
advise("and commit the result with 'git commit -c %s'",
find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
}
static void write_message(struct strbuf *msgbuf, const char *filename)
{
static struct lock_file msg_file;
int msg_fd = hold_lock_file_for_update(&msg_file, filename,
LOCK_DIE_ON_ERROR);
if (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0)
die_errno("Could not write to %s.", filename);
strbuf_release(msgbuf);
if (commit_lock_file(&msg_file) < 0)
die("Error wrapping up %s", filename);
}
static struct tree *empty_tree(void)
{
struct tree *tree = xcalloc(1, sizeof(struct tree));
tree->object.parsed = 1;
tree->object.type = OBJ_TREE;
pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
return tree;
}
static NORETURN void die_dirty_index(const char *me)
{
if (read_cache_unmerged()) {
die_resolve_conflict(me);
} else {
if (advice_commit_before_merge)
die("Your local changes would be overwritten by %s.\n"
"Please, commit your changes or stash them to proceed.", me);
else
die("Your local changes would be overwritten by %s.\n", me);
}
}
static int fast_forward_to(const unsigned char *to, const unsigned char *from)
{
struct ref_lock *ref_lock;
read_cache();
if (checkout_fast_forward(from, to))
exit(1); /* the callee should have complained already */
ref_lock = lock_any_ref_for_update("HEAD", from, 0);
return write_ref_sha1(ref_lock, to, "cherry-pick");
}
static int do_recursive_merge(struct commit *base, struct commit *next,
const char *base_label, const char *next_label,
unsigned char *head, struct strbuf *msgbuf)
{
struct merge_options o;
struct tree *result, *next_tree, *base_tree, *head_tree;
int clean, index_fd;
static struct lock_file index_lock;
index_fd = hold_locked_index(&index_lock, 1);
read_cache();
/*
* NEEDSWORK: cherry-picking between branches with
* different end-of-line normalization is a pain;
* plumb in an option to set o.renormalize?
* (or better: arbitrary -X options)
*/
init_merge_options(&o);
o.ancestor = base ? base_label : "(empty tree)";
o.branch1 = "HEAD";
o.branch2 = next ? next_label : "(empty tree)";
head_tree = parse_tree_indirect(head);
next_tree = next ? next->tree : empty_tree();
base_tree = base ? base->tree : empty_tree();
clean = merge_trees(&o,
head_tree,
next_tree, base_tree, &result);
if (active_cache_changed &&
(write_cache(index_fd, active_cache, active_nr) ||
commit_locked_index(&index_lock)))
die("%s: Unable to write new index file", me);
rollback_lock_file(&index_lock);
if (!clean) {
int i;
strbuf_addstr(msgbuf, "\nConflicts:\n\n");
for (i = 0; i < active_nr;) {
struct cache_entry *ce = active_cache[i++];
if (ce_stage(ce)) {
strbuf_addch(msgbuf, '\t');
strbuf_addstr(msgbuf, ce->name);
strbuf_addch(msgbuf, '\n');
while (i < active_nr && !strcmp(ce->name,
active_cache[i]->name))
i++;
}
}
}
return !clean;
}
/*
* If we are cherry-pick, and if the merge did not result in
* hand-editing, we will hit this commit and inherit the original
* author date and name.
* If we are revert, or if our cherry-pick results in a hand merge,
* we had better say that the current user is responsible for that.
*/
static int run_git_commit(const char *defmsg)
{
/* 6 is max possible length of our args array including NULL */
const char *args[6];
int i = 0;
args[i++] = "commit";
args[i++] = "-n";
if (signoff)
args[i++] = "-s";
if (!edit) {
args[i++] = "-F";
args[i++] = defmsg;
}
args[i] = NULL;
return run_command_v_opt(args, RUN_GIT_CMD);
}
static int do_pick_commit(void)
{
unsigned char head[20];
struct commit *base, *next, *parent;
const char *base_label, *next_label;
struct commit_message msg = { NULL, NULL, NULL, NULL, NULL };
char *defmsg = NULL;
struct strbuf msgbuf = STRBUF_INIT;
int res;
if (no_commit) {
/*
* We do not intend to commit immediately. We just want to
* merge the differences in, so let's compute the tree
* that represents the "current" state for merge-recursive
* to work on.
*/
if (write_cache_as_tree(head, 0, NULL))
die ("Your index file is unmerged.");
} else {
if (get_sha1("HEAD", head))
die ("You do not have a valid HEAD");
if (index_differs_from("HEAD", 0))
die_dirty_index(me);
}
discard_cache();
if (!commit->parents) {
if (action == REVERT)
die ("Cannot revert a root commit");
parent = NULL;
}
else if (commit->parents->next) {
/* Reverting or cherry-picking a merge commit */
int cnt;
struct commit_list *p;
if (!mainline)
die("Commit %s is a merge but no -m option was given.",
sha1_to_hex(commit->object.sha1));
for (cnt = 1, p = commit->parents;
cnt != mainline && p;
cnt++)
p = p->next;
if (cnt != mainline || !p)
die("Commit %s does not have parent %d",
sha1_to_hex(commit->object.sha1), mainline);
parent = p->item;
} else if (0 < mainline)
die("Mainline was specified but commit %s is not a merge.",
sha1_to_hex(commit->object.sha1));
else
parent = commit->parents->item;
if (allow_ff && parent && !hashcmp(parent->object.sha1, head))
return fast_forward_to(commit->object.sha1, head);
if (parent && parse_commit(parent) < 0)
die("%s: cannot parse parent commit %s",
me, sha1_to_hex(parent->object.sha1));
if (get_message(commit->buffer, &msg) != 0)
die("Cannot get commit message for %s",
sha1_to_hex(commit->object.sha1));
/*
* "commit" is an existing commit. We would want to apply
* the difference it introduces since its first parent "prev"
* on top of the current HEAD if we are cherry-pick. Or the
* reverse of it if we are revert.
*/
defmsg = git_pathdup("MERGE_MSG");
if (action == REVERT) {
base = commit;
base_label = msg.label;
next = parent;
next_label = msg.parent_label;
strbuf_addstr(&msgbuf, "Revert \"");
strbuf_addstr(&msgbuf, msg.subject);
strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
if (commit->parents->next) {
strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
strbuf_addstr(&msgbuf, sha1_to_hex(parent->object.sha1));
}
strbuf_addstr(&msgbuf, ".\n");
} else {
base = parent;
base_label = msg.parent_label;
next = commit;
next_label = msg.label;
set_author_ident_env(msg.message);
add_message_to_msg(&msgbuf, msg.message);
if (no_replay) {
strbuf_addstr(&msgbuf, "(cherry picked from commit ");
strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
strbuf_addstr(&msgbuf, ")\n");
}
}
if (!strategy || !strcmp(strategy, "recursive") || action == REVERT) {
res = do_recursive_merge(base, next, base_label, next_label,
head, &msgbuf);
write_message(&msgbuf, defmsg);
} else {
struct commit_list *common = NULL;
struct commit_list *remotes = NULL;
write_message(&msgbuf, defmsg);
commit_list_insert(base, &common);
commit_list_insert(next, &remotes);
res = try_merge_command(strategy, common,
sha1_to_hex(head), remotes);
free_commit_list(common);
free_commit_list(remotes);
}
if (res) {
error("could not %s %s... %s",
action == REVERT ? "revert" : "apply",
find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV),
msg.subject);
print_advice();
rerere(allow_rerere_auto);
} else {
if (!no_commit)
res = run_git_commit(defmsg);
}
free_message(&msg);
free(defmsg);
return res;
}
static void prepare_revs(struct rev_info *revs)
{
int argc;
init_revisions(revs, NULL);
revs->no_walk = 1;
if (action != REVERT)
revs->reverse = 1;
argc = setup_revisions(commit_argc, commit_argv, revs, NULL);
if (argc > 1)
usage(*revert_or_cherry_pick_usage());
if (prepare_revision_walk(revs))
die("revision walk setup failed");
if (!revs->commits)
die("empty commit set passed");
}
static void read_and_refresh_cache(const char *me)
{
static struct lock_file index_lock;
int index_fd = hold_locked_index(&index_lock, 0);
if (read_index_preload(&the_index, NULL) < 0)
die("git %s: failed to read the index", me);
refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
if (the_index.cache_changed) {
if (write_index(&the_index, index_fd) ||
commit_locked_index(&index_lock))
die("git %s: failed to refresh the index", me);
}
rollback_lock_file(&index_lock);
}
static int revert_or_cherry_pick(int argc, const char **argv)
{
struct rev_info revs;
git_config(git_default_config, NULL);
me = action == REVERT ? "revert" : "cherry-pick";
setenv(GIT_REFLOG_ACTION, me, 0);
parse_args(argc, argv);
if (allow_ff) {
if (signoff)
die("cherry-pick --ff cannot be used with --signoff");
if (no_commit)
die("cherry-pick --ff cannot be used with --no-commit");
if (no_replay)
die("cherry-pick --ff cannot be used with -x");
if (edit)
die("cherry-pick --ff cannot be used with --edit");
}
read_and_refresh_cache(me);
prepare_revs(&revs);
while ((commit = get_revision(&revs))) {
int res = do_pick_commit();
if (res)
return res;
}
return 0;
}
int cmd_revert(int argc, const char **argv, const char *prefix)
{
if (isatty(0))
edit = 1;
action = REVERT;
return revert_or_cherry_pick(argc, argv);
}
int cmd_cherry_pick(int argc, const char **argv, const char *prefix)
{
action = CHERRY_PICK;
return revert_or_cherry_pick(argc, argv);
}