Merge branch 'ss/builtin-cleanup'

"git help $cmd" unnecessarily enumerated potential command names
from the filesystem, even when $cmd is known to be a built-in.

Ideas for further optimization, primarily by killing the use of
is_in_cmdlist(), were suggested in the discussion, but they can
come as follow-ups on top of this series.

* ss/builtin-cleanup:
  builtin/help.c: speed up is_git_command() by checking for builtin commands first
  builtin/help.c: call load_command_list() only when it is needed
  git.c: consistently use the term "builtin" instead of "internal command"

Documentation/technical/api-builtin.txt

@@ -14,8 +14,8 @@ Git:
 
 . Add the external declaration for the function to `builtin.h`.
 
-. Add the command to `commands[]` table in `handle_internal_command()`,
-  defined in `git.c`.  The entry should look like:
+. Add the command to the `commands[]` table defined in `git.c`.
+  The entry should look like:
 
 	{ "foo", cmd_foo, <options> },
 +

builtin.h

@@ -27,6 +27,8 @@ extern int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
 
 extern int textconv_object(const char *path, unsigned mode, const unsigned char *sha1, int sha1_valid, char **buf, unsigned long *buf_size);
 
+extern int is_builtin(const char *s);
+
 extern int cmd_add(int argc, const char **argv, const char *prefix);
 extern int cmd_annotate(int argc, const char **argv, const char *prefix);
 extern int cmd_apply(int argc, const char **argv, const char *prefix);

builtin/help.c

@@ -288,6 +288,10 @@ static struct cmdnames main_cmds, other_cmds;
 
 static int is_git_command(const char *s)
 {
+	if (is_builtin(s))
+		return 1;
+
+	load_command_list("git-", &main_cmds, &other_cmds);
 	return is_in_cmdlist(&main_cmds, s) ||
 		is_in_cmdlist(&other_cmds, s);
 }
@@ -449,7 +453,6 @@ int cmd_help(int argc, const char **argv, const char *prefix)
 	int nongit;
 	const char *alias;
 	enum help_format parsed_help_format;
-	load_command_list("git-", &main_cmds, &other_cmds);
 
 	argc = parse_options(argc, argv, prefix, builtin_help_options,
 			builtin_help_usage, 0);
@@ -458,6 +461,7 @@ int cmd_help(int argc, const char **argv, const char *prefix)
 	if (show_all) {
 		git_config(git_help_config, NULL);
 		printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
+		load_command_list("git-", &main_cmds, &other_cmds);
 		list_commands(colopts, &main_cmds, &other_cmds);
 	}
 

git.c

@@ -332,10 +332,7 @@ static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 	return 0;
 }
 
-static void handle_internal_command(int argc, const char **argv)
-{
-	const char *cmd = argv[0];
-	static struct cmd_struct commands[] = {
+static struct cmd_struct commands[] = {
 	{ "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 	{ "annotate", cmd_annotate, RUN_SETUP },
 	{ "apply", cmd_apply, RUN_SETUP_GENTLY },
@@ -449,7 +446,22 @@ static void handle_internal_command(int argc, const char **argv)
 	{ "version", cmd_version },
 	{ "whatchanged", cmd_whatchanged, RUN_SETUP },
 	{ "write-tree", cmd_write_tree, RUN_SETUP },
-	};
+};
+
+int is_builtin(const char *s)
+{
+	int i;
+	for (i = 0; i < ARRAY_SIZE(commands); i++) {
+		struct cmd_struct *p = commands+i;
+		if (!strcmp(s, p->cmd))
+			return 1;
+	}
+	return 0;
+}
+
+static void handle_builtin(int argc, const char **argv)
+{
+	const char *cmd = argv[0];
 	int i;
 	static const char ext[] = STRIP_EXTENSION;
 
@@ -517,8 +529,8 @@ static int run_argv(int *argcp, const char ***argv)
 	int done_alias = 0;
 
 	while (1) {
-		/* See if it's an internal command */
-		handle_internal_command(*argcp, *argv);
+		/* See if it's a builtin */
+		handle_builtin(*argcp, *argv);
 
 		/* .. then try the external ones */
 		execv_dashed_external(*argv);
@@ -563,14 +575,14 @@ int main(int argc, char **av)
 	 *  - cannot execute it externally (since it would just do
 	 *    the same thing over again)
 	 *
-	 * So we just directly call the internal command handler, and
-	 * die if that one cannot handle it.
+	 * So we just directly call the builtin handler, and die if
+	 * that one cannot handle it.
 	 */
 	if (starts_with(cmd, "git-")) {
 		cmd += 4;
 		argv[0] = cmd;
-		handle_internal_command(argc, argv);
-		die("cannot handle %s internally", cmd);
+		handle_builtin(argc, argv);
+		die("cannot handle %s as a builtin", cmd);
 	}
 
 	/* Look for flags.. */