git/builtin/replace.c
Derrick Stolee 97e61e0f9c refs: use ref_namespaces for replace refs base
The git_replace_ref_base global is used to store the value of the
GIT_REPLACE_REF_BASE environment variable or the default of
"refs/replace/". This is initialized within setup_git_env().

The ref_namespaces array is a new centralized location for information
such as the ref namespace used for replace refs. Instead of having this
namespace stored in two places, use the ref_namespaces array instead.

For simplicity, create a local git_replace_ref_base variable wherever
the global was previously used.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-05 14:13:12 -07:00

627 lines
17 KiB
C

/*
* Builtin "git replace"
*
* Copyright (c) 2008 Christian Couder <chriscool@tuxfamily.org>
*
* Based on builtin/tag.c by Kristian Høgsberg <krh@redhat.com>
* and Carlos Rica <jasampler@gmail.com> that was itself based on
* git-tag.sh and mktag.c by Linus Torvalds.
*/
#include "cache.h"
#include "config.h"
#include "builtin.h"
#include "refs.h"
#include "parse-options.h"
#include "run-command.h"
#include "object-store.h"
#include "repository.h"
#include "tag.h"
static const char * const git_replace_usage[] = {
N_("git replace [-f] <object> <replacement>"),
N_("git replace [-f] --edit <object>"),
N_("git replace [-f] --graft <commit> [<parent>...]"),
"git replace [-f] --convert-graft-file",
N_("git replace -d <object>..."),
N_("git replace [--format=<format>] [-l [<pattern>]]"),
NULL
};
enum replace_format {
REPLACE_FORMAT_SHORT,
REPLACE_FORMAT_MEDIUM,
REPLACE_FORMAT_LONG
};
struct show_data {
const char *pattern;
enum replace_format format;
};
static int show_reference(struct repository *r, const char *refname,
const struct object_id *oid,
int flag, void *cb_data)
{
struct show_data *data = cb_data;
if (!wildmatch(data->pattern, refname, 0)) {
if (data->format == REPLACE_FORMAT_SHORT)
printf("%s\n", refname);
else if (data->format == REPLACE_FORMAT_MEDIUM)
printf("%s -> %s\n", refname, oid_to_hex(oid));
else { /* data->format == REPLACE_FORMAT_LONG */
struct object_id object;
enum object_type obj_type, repl_type;
if (get_oid(refname, &object))
return error(_("failed to resolve '%s' as a valid ref"), refname);
obj_type = oid_object_info(r, &object, NULL);
repl_type = oid_object_info(r, oid, NULL);
printf("%s (%s) -> %s (%s)\n", refname, type_name(obj_type),
oid_to_hex(oid), type_name(repl_type));
}
}
return 0;
}
static int list_replace_refs(const char *pattern, const char *format)
{
struct show_data data;
if (!pattern)
pattern = "*";
data.pattern = pattern;
if (format == NULL || *format == '\0' || !strcmp(format, "short"))
data.format = REPLACE_FORMAT_SHORT;
else if (!strcmp(format, "medium"))
data.format = REPLACE_FORMAT_MEDIUM;
else if (!strcmp(format, "long"))
data.format = REPLACE_FORMAT_LONG;
/*
* Please update _git_replace() in git-completion.bash when
* you add new format
*/
else
return error(_("invalid replace format '%s'\n"
"valid formats are 'short', 'medium' and 'long'"),
format);
for_each_replace_ref(the_repository, show_reference, (void *)&data);
return 0;
}
typedef int (*each_replace_name_fn)(const char *name, const char *ref,
const struct object_id *oid);
static int for_each_replace_name(const char **argv, each_replace_name_fn fn)
{
const char **p, *full_hex;
struct strbuf ref = STRBUF_INIT;
size_t base_len;
int had_error = 0;
struct object_id oid;
const char *git_replace_ref_base = ref_namespace[NAMESPACE_REPLACE].ref;
strbuf_addstr(&ref, git_replace_ref_base);
base_len = ref.len;
for (p = argv; *p; p++) {
if (get_oid(*p, &oid)) {
error("failed to resolve '%s' as a valid ref", *p);
had_error = 1;
continue;
}
strbuf_setlen(&ref, base_len);
strbuf_addstr(&ref, oid_to_hex(&oid));
full_hex = ref.buf + base_len;
if (read_ref(ref.buf, &oid)) {
error(_("replace ref '%s' not found"), full_hex);
had_error = 1;
continue;
}
if (fn(full_hex, ref.buf, &oid))
had_error = 1;
}
strbuf_release(&ref);
return had_error;
}
static int delete_replace_ref(const char *name, const char *ref,
const struct object_id *oid)
{
if (delete_ref(NULL, ref, oid, 0))
return 1;
printf_ln(_("Deleted replace ref '%s'"), name);
return 0;
}
static int check_ref_valid(struct object_id *object,
struct object_id *prev,
struct strbuf *ref,
int force)
{
const char *git_replace_ref_base = ref_namespace[NAMESPACE_REPLACE].ref;
strbuf_reset(ref);
strbuf_addf(ref, "%s%s", git_replace_ref_base, oid_to_hex(object));
if (check_refname_format(ref->buf, 0))
return error(_("'%s' is not a valid ref name"), ref->buf);
if (read_ref(ref->buf, prev))
oidclr(prev);
else if (!force)
return error(_("replace ref '%s' already exists"), ref->buf);
return 0;
}
static int replace_object_oid(const char *object_ref,
struct object_id *object,
const char *replace_ref,
struct object_id *repl,
int force)
{
struct object_id prev;
enum object_type obj_type, repl_type;
struct strbuf ref = STRBUF_INIT;
struct ref_transaction *transaction;
struct strbuf err = STRBUF_INIT;
int res = 0;
obj_type = oid_object_info(the_repository, object, NULL);
repl_type = oid_object_info(the_repository, repl, NULL);
if (!force && obj_type != repl_type)
return error(_("Objects must be of the same type.\n"
"'%s' points to a replaced object of type '%s'\n"
"while '%s' points to a replacement object of "
"type '%s'."),
object_ref, type_name(obj_type),
replace_ref, type_name(repl_type));
if (check_ref_valid(object, &prev, &ref, force)) {
strbuf_release(&ref);
return -1;
}
transaction = ref_transaction_begin(&err);
if (!transaction ||
ref_transaction_update(transaction, ref.buf, repl, &prev,
0, NULL, &err) ||
ref_transaction_commit(transaction, &err))
res = error("%s", err.buf);
ref_transaction_free(transaction);
strbuf_release(&ref);
return res;
}
static int replace_object(const char *object_ref, const char *replace_ref, int force)
{
struct object_id object, repl;
if (get_oid(object_ref, &object))
return error(_("failed to resolve '%s' as a valid ref"),
object_ref);
if (get_oid(replace_ref, &repl))
return error(_("failed to resolve '%s' as a valid ref"),
replace_ref);
return replace_object_oid(object_ref, &object, replace_ref, &repl, force);
}
/*
* Write the contents of the object named by "sha1" to the file "filename".
* If "raw" is true, then the object's raw contents are printed according to
* "type". Otherwise, we pretty-print the contents for human editing.
*/
static int export_object(const struct object_id *oid, enum object_type type,
int raw, const char *filename)
{
struct child_process cmd = CHILD_PROCESS_INIT;
int fd;
fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
if (fd < 0)
return error_errno(_("unable to open %s for writing"), filename);
strvec_push(&cmd.args, "--no-replace-objects");
strvec_push(&cmd.args, "cat-file");
if (raw)
strvec_push(&cmd.args, type_name(type));
else
strvec_push(&cmd.args, "-p");
strvec_push(&cmd.args, oid_to_hex(oid));
cmd.git_cmd = 1;
cmd.out = fd;
if (run_command(&cmd))
return error(_("cat-file reported failure"));
return 0;
}
/*
* Read a previously-exported (and possibly edited) object back from "filename",
* interpreting it as "type", and writing the result to the object database.
* The sha1 of the written object is returned via sha1.
*/
static int import_object(struct object_id *oid, enum object_type type,
int raw, const char *filename)
{
int fd;
fd = open(filename, O_RDONLY);
if (fd < 0)
return error_errno(_("unable to open %s for reading"), filename);
if (!raw && type == OBJ_TREE) {
struct child_process cmd = CHILD_PROCESS_INIT;
struct strbuf result = STRBUF_INIT;
strvec_push(&cmd.args, "mktree");
cmd.git_cmd = 1;
cmd.in = fd;
cmd.out = -1;
if (start_command(&cmd)) {
close(fd);
return error(_("unable to spawn mktree"));
}
if (strbuf_read(&result, cmd.out, the_hash_algo->hexsz + 1) < 0) {
error_errno(_("unable to read from mktree"));
close(fd);
close(cmd.out);
return -1;
}
close(cmd.out);
if (finish_command(&cmd)) {
strbuf_release(&result);
return error(_("mktree reported failure"));
}
if (get_oid_hex(result.buf, oid) < 0) {
strbuf_release(&result);
return error(_("mktree did not return an object name"));
}
strbuf_release(&result);
} else {
struct stat st;
int flags = HASH_FORMAT_CHECK | HASH_WRITE_OBJECT;
if (fstat(fd, &st) < 0) {
error_errno(_("unable to fstat %s"), filename);
close(fd);
return -1;
}
if (index_fd(the_repository->index, oid, fd, &st, type, NULL, flags) < 0)
return error(_("unable to write object to database"));
/* index_fd close()s fd for us */
}
/*
* No need to close(fd) here; both run-command and index-fd
* will have done it for us.
*/
return 0;
}
static int edit_and_replace(const char *object_ref, int force, int raw)
{
char *tmpfile;
enum object_type type;
struct object_id old_oid, new_oid, prev;
struct strbuf ref = STRBUF_INIT;
if (get_oid(object_ref, &old_oid) < 0)
return error(_("not a valid object name: '%s'"), object_ref);
type = oid_object_info(the_repository, &old_oid, NULL);
if (type < 0)
return error(_("unable to get object type for %s"),
oid_to_hex(&old_oid));
if (check_ref_valid(&old_oid, &prev, &ref, force)) {
strbuf_release(&ref);
return -1;
}
strbuf_release(&ref);
tmpfile = git_pathdup("REPLACE_EDITOBJ");
if (export_object(&old_oid, type, raw, tmpfile)) {
free(tmpfile);
return -1;
}
if (launch_editor(tmpfile, NULL, NULL) < 0) {
free(tmpfile);
return error(_("editing object file failed"));
}
if (import_object(&new_oid, type, raw, tmpfile)) {
free(tmpfile);
return -1;
}
free(tmpfile);
if (oideq(&old_oid, &new_oid))
return error(_("new object is the same as the old one: '%s'"), oid_to_hex(&old_oid));
return replace_object_oid(object_ref, &old_oid, "replacement", &new_oid, force);
}
static int replace_parents(struct strbuf *buf, int argc, const char **argv)
{
struct strbuf new_parents = STRBUF_INIT;
const char *parent_start, *parent_end;
int i;
const unsigned hexsz = the_hash_algo->hexsz;
/* find existing parents */
parent_start = buf->buf;
parent_start += hexsz + 6; /* "tree " + "hex sha1" + "\n" */
parent_end = parent_start;
while (starts_with(parent_end, "parent "))
parent_end += hexsz + 8; /* "parent " + "hex sha1" + "\n" */
/* prepare new parents */
for (i = 0; i < argc; i++) {
struct object_id oid;
struct commit *commit;
if (get_oid(argv[i], &oid) < 0) {
strbuf_release(&new_parents);
return error(_("not a valid object name: '%s'"),
argv[i]);
}
commit = lookup_commit_reference(the_repository, &oid);
if (!commit) {
strbuf_release(&new_parents);
return error(_("could not parse %s as a commit"), argv[i]);
}
strbuf_addf(&new_parents, "parent %s\n", oid_to_hex(&commit->object.oid));
}
/* replace existing parents with new ones */
strbuf_splice(buf, parent_start - buf->buf, parent_end - parent_start,
new_parents.buf, new_parents.len);
strbuf_release(&new_parents);
return 0;
}
struct check_mergetag_data {
int argc;
const char **argv;
};
static int check_one_mergetag(struct commit *commit,
struct commit_extra_header *extra,
void *data)
{
struct check_mergetag_data *mergetag_data = (struct check_mergetag_data *)data;
const char *ref = mergetag_data->argv[0];
struct object_id tag_oid;
struct tag *tag;
int i;
hash_object_file(the_hash_algo, extra->value, extra->len,
OBJ_TAG, &tag_oid);
tag = lookup_tag(the_repository, &tag_oid);
if (!tag)
return error(_("bad mergetag in commit '%s'"), ref);
if (parse_tag_buffer(the_repository, tag, extra->value, extra->len))
return error(_("malformed mergetag in commit '%s'"), ref);
/* iterate over new parents */
for (i = 1; i < mergetag_data->argc; i++) {
struct object_id oid;
if (get_oid(mergetag_data->argv[i], &oid) < 0)
return error(_("not a valid object name: '%s'"),
mergetag_data->argv[i]);
if (oideq(get_tagged_oid(tag), &oid))
return 0; /* found */
}
return error(_("original commit '%s' contains mergetag '%s' that is "
"discarded; use --edit instead of --graft"), ref,
oid_to_hex(&tag_oid));
}
static int check_mergetags(struct commit *commit, int argc, const char **argv)
{
struct check_mergetag_data mergetag_data;
mergetag_data.argc = argc;
mergetag_data.argv = argv;
return for_each_mergetag(check_one_mergetag, commit, &mergetag_data);
}
static int create_graft(int argc, const char **argv, int force, int gentle)
{
struct object_id old_oid, new_oid;
const char *old_ref = argv[0];
struct commit *commit;
struct strbuf buf = STRBUF_INIT;
const char *buffer;
unsigned long size;
if (get_oid(old_ref, &old_oid) < 0)
return error(_("not a valid object name: '%s'"), old_ref);
commit = lookup_commit_reference(the_repository, &old_oid);
if (!commit)
return error(_("could not parse %s"), old_ref);
buffer = get_commit_buffer(commit, &size);
strbuf_add(&buf, buffer, size);
unuse_commit_buffer(commit, buffer);
if (replace_parents(&buf, argc - 1, &argv[1]) < 0) {
strbuf_release(&buf);
return -1;
}
if (remove_signature(&buf)) {
warning(_("the original commit '%s' has a gpg signature"), old_ref);
warning(_("the signature will be removed in the replacement commit!"));
}
if (check_mergetags(commit, argc, argv)) {
strbuf_release(&buf);
return -1;
}
if (write_object_file(buf.buf, buf.len, OBJ_COMMIT, &new_oid)) {
strbuf_release(&buf);
return error(_("could not write replacement commit for: '%s'"),
old_ref);
}
strbuf_release(&buf);
if (oideq(&commit->object.oid, &new_oid)) {
if (gentle) {
warning(_("graft for '%s' unnecessary"),
oid_to_hex(&commit->object.oid));
return 0;
}
return error(_("new commit is the same as the old one: '%s'"),
oid_to_hex(&commit->object.oid));
}
return replace_object_oid(old_ref, &commit->object.oid,
"replacement", &new_oid, force);
}
static int convert_graft_file(int force)
{
const char *graft_file = get_graft_file(the_repository);
FILE *fp = fopen_or_warn(graft_file, "r");
struct strbuf buf = STRBUF_INIT, err = STRBUF_INIT;
struct strvec args = STRVEC_INIT;
if (!fp)
return -1;
no_graft_file_deprecated_advice = 1;
while (strbuf_getline(&buf, fp) != EOF) {
if (*buf.buf == '#')
continue;
strvec_split(&args, buf.buf);
if (args.nr && create_graft(args.nr, args.v, force, 1))
strbuf_addf(&err, "\n\t%s", buf.buf);
strvec_clear(&args);
}
fclose(fp);
strbuf_release(&buf);
if (!err.len)
return unlink_or_warn(graft_file);
warning(_("could not convert the following graft(s):\n%s"), err.buf);
strbuf_release(&err);
return -1;
}
int cmd_replace(int argc, const char **argv, const char *prefix)
{
int force = 0;
int raw = 0;
const char *format = NULL;
enum {
MODE_UNSPECIFIED = 0,
MODE_LIST,
MODE_DELETE,
MODE_EDIT,
MODE_GRAFT,
MODE_CONVERT_GRAFT_FILE,
MODE_REPLACE
} cmdmode = MODE_UNSPECIFIED;
struct option options[] = {
OPT_CMDMODE('l', "list", &cmdmode, N_("list replace refs"), MODE_LIST),
OPT_CMDMODE('d', "delete", &cmdmode, N_("delete replace refs"), MODE_DELETE),
OPT_CMDMODE('e', "edit", &cmdmode, N_("edit existing object"), MODE_EDIT),
OPT_CMDMODE('g', "graft", &cmdmode, N_("change a commit's parents"), MODE_GRAFT),
OPT_CMDMODE(0, "convert-graft-file", &cmdmode, N_("convert existing graft file"), MODE_CONVERT_GRAFT_FILE),
OPT_BOOL_F('f', "force", &force, N_("replace the ref if it exists"),
PARSE_OPT_NOCOMPLETE),
OPT_BOOL(0, "raw", &raw, N_("do not pretty-print contents for --edit")),
OPT_STRING(0, "format", &format, N_("format"), N_("use this format")),
OPT_END()
};
read_replace_refs = 0;
git_config(git_default_config, NULL);
argc = parse_options(argc, argv, prefix, options, git_replace_usage, 0);
if (!cmdmode)
cmdmode = argc ? MODE_REPLACE : MODE_LIST;
if (format && cmdmode != MODE_LIST)
usage_msg_opt(_("--format cannot be used when not listing"),
git_replace_usage, options);
if (force &&
cmdmode != MODE_REPLACE &&
cmdmode != MODE_EDIT &&
cmdmode != MODE_GRAFT &&
cmdmode != MODE_CONVERT_GRAFT_FILE)
usage_msg_opt(_("-f only makes sense when writing a replacement"),
git_replace_usage, options);
if (raw && cmdmode != MODE_EDIT)
usage_msg_opt(_("--raw only makes sense with --edit"),
git_replace_usage, options);
switch (cmdmode) {
case MODE_DELETE:
if (argc < 1)
usage_msg_opt(_("-d needs at least one argument"),
git_replace_usage, options);
return for_each_replace_name(argv, delete_replace_ref);
case MODE_REPLACE:
if (argc != 2)
usage_msg_opt(_("bad number of arguments"),
git_replace_usage, options);
return replace_object(argv[0], argv[1], force);
case MODE_EDIT:
if (argc != 1)
usage_msg_opt(_("-e needs exactly one argument"),
git_replace_usage, options);
return edit_and_replace(argv[0], force, raw);
case MODE_GRAFT:
if (argc < 1)
usage_msg_opt(_("-g needs at least one argument"),
git_replace_usage, options);
return create_graft(argc, argv, force, 0);
case MODE_CONVERT_GRAFT_FILE:
if (argc != 0)
usage_msg_opt(_("--convert-graft-file takes no argument"),
git_replace_usage, options);
return !!convert_graft_file(force);
case MODE_LIST:
if (argc > 1)
usage_msg_opt(_("only one pattern can be given with -l"),
git_replace_usage, options);
return list_replace_refs(argv[0], format);
default:
BUG("invalid cmdmode %d", (int)cmdmode);
}
}