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-rw-r--r--builtin/replace.c498
1 files changed, 498 insertions, 0 deletions
diff --git a/builtin/replace.c b/builtin/replace.c
new file mode 100644
index 0000000000..6b3c469a33
--- /dev/null
+++ b/builtin/replace.c
@@ -0,0 +1,498 @@
+/*
+ * 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 "builtin.h"
+#include "refs.h"
+#include "parse-options.h"
+#include "run-command.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>...]"),
+ 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(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, NULL)) {
+ 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_sha1(refname, object.hash))
+ return error("Failed to resolve '%s' as a valid ref.", refname);
+
+ obj_type = sha1_object_info(object.hash, NULL);
+ repl_type = sha1_object_info(oid->hash, NULL);
+
+ printf("%s (%s) -> %s (%s)\n", refname, typename(obj_type),
+ oid_to_hex(oid), typename(repl_type));
+ }
+ }
+
+ return 0;
+}
+
+static int list_replace_refs(const char *pattern, const char *format)
+{
+ struct show_data data;
+
+ if (pattern == NULL)
+ 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;
+ else
+ die("invalid replace format '%s'\n"
+ "valid formats are 'short', 'medium' and 'long'\n",
+ format);
+
+ for_each_replace_ref(show_reference, (void *)&data);
+
+ return 0;
+}
+
+typedef int (*each_replace_name_fn)(const char *name, const char *ref,
+ const unsigned char *sha1);
+
+static int for_each_replace_name(const char **argv, each_replace_name_fn fn)
+{
+ const char **p, *full_hex;
+ char ref[PATH_MAX];
+ int had_error = 0;
+ unsigned char sha1[20];
+
+ for (p = argv; *p; p++) {
+ if (get_sha1(*p, sha1)) {
+ error("Failed to resolve '%s' as a valid ref.", *p);
+ had_error = 1;
+ continue;
+ }
+ full_hex = sha1_to_hex(sha1);
+ snprintf(ref, sizeof(ref), "%s%s", git_replace_ref_base, full_hex);
+ /* read_ref() may reuse the buffer */
+ full_hex = ref + strlen(git_replace_ref_base);
+ if (read_ref(ref, sha1)) {
+ error("replace ref '%s' not found.", full_hex);
+ had_error = 1;
+ continue;
+ }
+ if (fn(full_hex, ref, sha1))
+ had_error = 1;
+ }
+ return had_error;
+}
+
+static int delete_replace_ref(const char *name, const char *ref,
+ const unsigned char *sha1)
+{
+ if (delete_ref(ref, sha1, 0))
+ return 1;
+ printf("Deleted replace ref '%s'\n", name);
+ return 0;
+}
+
+static void check_ref_valid(unsigned char object[20],
+ unsigned char prev[20],
+ char *ref,
+ int ref_size,
+ int force)
+{
+ if (snprintf(ref, ref_size,
+ "%s%s", git_replace_ref_base,
+ sha1_to_hex(object)) > ref_size - 1)
+ die("replace ref name too long: %.*s...", 50, ref);
+ if (check_refname_format(ref, 0))
+ die("'%s' is not a valid ref name.", ref);
+
+ if (read_ref(ref, prev))
+ hashclr(prev);
+ else if (!force)
+ die("replace ref '%s' already exists", ref);
+}
+
+static int replace_object_sha1(const char *object_ref,
+ unsigned char object[20],
+ const char *replace_ref,
+ unsigned char repl[20],
+ int force)
+{
+ unsigned char prev[20];
+ enum object_type obj_type, repl_type;
+ char ref[PATH_MAX];
+ struct ref_transaction *transaction;
+ struct strbuf err = STRBUF_INIT;
+
+ obj_type = sha1_object_info(object, NULL);
+ repl_type = sha1_object_info(repl, NULL);
+ if (!force && obj_type != repl_type)
+ die("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, typename(obj_type),
+ replace_ref, typename(repl_type));
+
+ check_ref_valid(object, prev, ref, sizeof(ref), force);
+
+ transaction = ref_transaction_begin(&err);
+ if (!transaction ||
+ ref_transaction_update(transaction, ref, repl, prev,
+ 0, NULL, &err) ||
+ ref_transaction_commit(transaction, &err))
+ die("%s", err.buf);
+
+ ref_transaction_free(transaction);
+ return 0;
+}
+
+static int replace_object(const char *object_ref, const char *replace_ref, int force)
+{
+ unsigned char object[20], repl[20];
+
+ if (get_sha1(object_ref, object))
+ die("Failed to resolve '%s' as a valid ref.", object_ref);
+ if (get_sha1(replace_ref, repl))
+ die("Failed to resolve '%s' as a valid ref.", replace_ref);
+
+ return replace_object_sha1(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 void export_object(const unsigned char *sha1, 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)
+ die_errno("unable to open %s for writing", filename);
+
+ argv_array_push(&cmd.args, "--no-replace-objects");
+ argv_array_push(&cmd.args, "cat-file");
+ if (raw)
+ argv_array_push(&cmd.args, typename(type));
+ else
+ argv_array_push(&cmd.args, "-p");
+ argv_array_push(&cmd.args, sha1_to_hex(sha1));
+ cmd.git_cmd = 1;
+ cmd.out = fd;
+
+ if (run_command(&cmd))
+ die("cat-file reported failure");
+}
+
+/*
+ * 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 void import_object(unsigned char *sha1, enum object_type type,
+ int raw, const char *filename)
+{
+ int fd;
+
+ fd = open(filename, O_RDONLY);
+ if (fd < 0)
+ die_errno("unable to open %s for reading", filename);
+
+ if (!raw && type == OBJ_TREE) {
+ const char *argv[] = { "mktree", NULL };
+ struct child_process cmd = CHILD_PROCESS_INIT;
+ struct strbuf result = STRBUF_INIT;
+
+ cmd.argv = argv;
+ cmd.git_cmd = 1;
+ cmd.in = fd;
+ cmd.out = -1;
+
+ if (start_command(&cmd))
+ die("unable to spawn mktree");
+
+ if (strbuf_read(&result, cmd.out, 41) < 0)
+ die_errno("unable to read from mktree");
+ close(cmd.out);
+
+ if (finish_command(&cmd))
+ die("mktree reported failure");
+ if (get_sha1_hex(result.buf, sha1) < 0)
+ die("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)
+ die_errno("unable to fstat %s", filename);
+ if (index_fd(sha1, fd, &st, type, NULL, flags) < 0)
+ die("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.
+ */
+}
+
+static int edit_and_replace(const char *object_ref, int force, int raw)
+{
+ char *tmpfile = git_pathdup("REPLACE_EDITOBJ");
+ enum object_type type;
+ unsigned char old[20], new[20], prev[20];
+ char ref[PATH_MAX];
+
+ if (get_sha1(object_ref, old) < 0)
+ die("Not a valid object name: '%s'", object_ref);
+
+ type = sha1_object_info(old, NULL);
+ if (type < 0)
+ die("unable to get object type for %s", sha1_to_hex(old));
+
+ check_ref_valid(old, prev, ref, sizeof(ref), force);
+
+ export_object(old, type, raw, tmpfile);
+ if (launch_editor(tmpfile, NULL, NULL) < 0)
+ die("editing object file failed");
+ import_object(new, type, raw, tmpfile);
+
+ free(tmpfile);
+
+ if (!hashcmp(old, new))
+ return error("new object is the same as the old one: '%s'", sha1_to_hex(old));
+
+ return replace_object_sha1(object_ref, old, "replacement", new, force);
+}
+
+static void replace_parents(struct strbuf *buf, int argc, const char **argv)
+{
+ struct strbuf new_parents = STRBUF_INIT;
+ const char *parent_start, *parent_end;
+ int i;
+
+ /* find existing parents */
+ parent_start = buf->buf;
+ parent_start += 46; /* "tree " + "hex sha1" + "\n" */
+ parent_end = parent_start;
+
+ while (starts_with(parent_end, "parent "))
+ parent_end += 48; /* "parent " + "hex sha1" + "\n" */
+
+ /* prepare new parents */
+ for (i = 0; i < argc; i++) {
+ unsigned char sha1[20];
+ if (get_sha1(argv[i], sha1) < 0)
+ die(_("Not a valid object name: '%s'"), argv[i]);
+ lookup_commit_or_die(sha1, argv[i]);
+ strbuf_addf(&new_parents, "parent %s\n", sha1_to_hex(sha1));
+ }
+
+ /* 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);
+}
+
+struct check_mergetag_data {
+ int argc;
+ const char **argv;
+};
+
+static void 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];
+ unsigned char tag_sha1[20];
+ struct tag *tag;
+ int i;
+
+ hash_sha1_file(extra->value, extra->len, typename(OBJ_TAG), tag_sha1);
+ tag = lookup_tag(tag_sha1);
+ if (!tag)
+ die(_("bad mergetag in commit '%s'"), ref);
+ if (parse_tag_buffer(tag, extra->value, extra->len))
+ die(_("malformed mergetag in commit '%s'"), ref);
+
+ /* iterate over new parents */
+ for (i = 1; i < mergetag_data->argc; i++) {
+ unsigned char sha1[20];
+ if (get_sha1(mergetag_data->argv[i], sha1) < 0)
+ die(_("Not a valid object name: '%s'"), mergetag_data->argv[i]);
+ if (!hashcmp(tag->tagged->sha1, sha1))
+ return; /* found */
+ }
+
+ die(_("original commit '%s' contains mergetag '%s' that is discarded; "
+ "use --edit instead of --graft"), ref, sha1_to_hex(tag_sha1));
+}
+
+static void check_mergetags(struct commit *commit, int argc, const char **argv)
+{
+ struct check_mergetag_data mergetag_data;
+
+ mergetag_data.argc = argc;
+ mergetag_data.argv = argv;
+ for_each_mergetag(check_one_mergetag, commit, &mergetag_data);
+}
+
+static int create_graft(int argc, const char **argv, int force)
+{
+ unsigned char old[20], new[20];
+ const char *old_ref = argv[0];
+ struct commit *commit;
+ struct strbuf buf = STRBUF_INIT;
+ const char *buffer;
+ unsigned long size;
+
+ if (get_sha1(old_ref, old) < 0)
+ die(_("Not a valid object name: '%s'"), old_ref);
+ commit = lookup_commit_or_die(old, old_ref);
+
+ buffer = get_commit_buffer(commit, &size);
+ strbuf_add(&buf, buffer, size);
+ unuse_commit_buffer(commit, buffer);
+
+ replace_parents(&buf, argc - 1, &argv[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!"));
+ }
+
+ check_mergetags(commit, argc, argv);
+
+ if (write_sha1_file(buf.buf, buf.len, commit_type, new))
+ die(_("could not write replacement commit for: '%s'"), old_ref);
+
+ strbuf_release(&buf);
+
+ if (!hashcmp(old, new))
+ return error("new commit is the same as the old one: '%s'", sha1_to_hex(old));
+
+ return replace_object_sha1(old_ref, old, "replacement", new, force);
+}
+
+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_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_BOOL('f', "force", &force, N_("replace the ref if it exists")),
+ 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()
+ };
+
+ check_replace_refs = 0;
+
+ 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)
+ 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);
+
+ 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:
+ die("BUG: invalid cmdmode %d", (int)cmdmode);
+ }
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-22 05:46:43 +0000