discover/grub2: Function infrastructure improvements

For user-defined functions, we'll need a data pointer to the function's
execution callback. Add this as a void *, and change references from
'command' to 'function'.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

3 files changed, 52 insertions, 38 deletions

diff --git a/discover/grub2/builtins.c b/discover/grub2/builtins.c
index 379e870..55597c1 100644
--- a/discover/grub2/builtins.c
+++ b/discover/grub2/builtins.c
@@ -8,7 +8,9 @@
 #include "grub2.h"
 
 
-static int builtin_set(struct grub2_script *script, int argc, char *argv[])
+static int builtin_set(struct grub2_script *script,
+		void *data __attribute__((unused)),
+		int argc, char *argv[])
 {
 	char *name, *value, *p;
 	int i;
@@ -31,10 +33,13 @@ static int builtin_set(struct grub2_script *script, int argc, char *argv[])
 	return 0;
 }
 
-static struct grub2_command commands[] = {
+static struct {
+	const char *name;
+	grub2_function fn;
+} builtins[] = {
 	{
 		.name = "set",
-		.exec = builtin_set
+		.fn = builtin_set
 	},
 };
 
@@ -42,6 +47,7 @@ void register_builtins(struct grub2_script *script)
 {
 	unsigned int i;
 
-	for (i = 0; i < ARRAY_SIZE(commands); i++)
-		script_register_command(script, &commands[i]);
+	for (i = 0; i < ARRAY_SIZE(builtins); i++)
+		script_register_function(script, builtins[i].name,
+				builtins[i].fn, NULL);
 }
diff --git a/discover/grub2/grub2.h b/discover/grub2/grub2.h
index 1ac9f88..2de77a2 100644
--- a/discover/grub2/grub2.h
+++ b/discover/grub2/grub2.h
@@ -71,17 +71,10 @@ struct grub2_statement_block {
 	struct grub2_statements	*statements;
 };
 
-struct grub2_command {
-	const char		*name;
-	int			(*exec)(struct grub2_script *script,
-					int argc, char *argv[]);
-	struct list_item	list;
-};
 
 struct grub2_script {
 	struct grub2_statements		*statements;
 	struct list			environment;
-	struct list			commands;
 	struct list			symtab;
 	struct discover_context		*ctx;
 	struct discover_boot_option	*opt;
@@ -96,6 +89,10 @@ struct grub2_root {
 	char *uuid;
 };
 
+/* type for builtin functions */
+typedef int (*grub2_function)(struct grub2_script *script, void *data,
+				int argc, char *argv[]);
+
 struct grub2_statements *create_statements(struct grub2_parser *parser);
 
 struct grub2_statement *create_statement_simple(struct grub2_parser *parser,
@@ -145,11 +142,8 @@ const char *script_env_get(struct grub2_script *script, const char *name);
 void script_env_set(struct grub2_script *script,
 		const char *name, const char *value);
 
-void script_register_command(struct grub2_script *script,
-		struct grub2_command *command);
-
-struct grub2_command *script_lookup_command(struct grub2_script *script,
-		const char *name);
+void script_register_function(struct grub2_script *script,
+		const char *name, grub2_function fn, void *data);
 
 void register_builtins(struct grub2_script *script);
 
diff --git a/discover/grub2/script.c b/discover/grub2/script.c
index 8b008c4..ec37fbb 100644
--- a/discover/grub2/script.c
+++ b/discover/grub2/script.c
@@ -20,6 +20,26 @@ struct env_entry {
 	struct list_item	list;
 };
 
+struct grub2_symtab_entry {
+	const char		*name;
+	grub2_function		fn;
+	void			*data;
+	struct list_item	list;
+};
+
+static struct grub2_symtab_entry *script_lookup_function(
+		struct grub2_script *script, const char *name)
+{
+	struct grub2_symtab_entry *entry;
+
+	list_for_each_entry(&script->symtab, entry, list) {
+		if (!strcmp(entry->name, name))
+			return entry;
+	}
+
+	return NULL;
+}
+
 const char *script_env_get(struct grub2_script *script, const char *name)
 {
 	struct env_entry *entry;
@@ -208,7 +228,7 @@ int statement_simple_execute(struct grub2_script *script,
 		struct grub2_statement *statement)
 {
 	struct grub2_statement_simple *st = to_stmt_simple(statement);
-	struct grub2_command *cmd;
+	struct grub2_symtab_entry *entry;
 	int rc;
 
 	if (!st->argv)
@@ -219,13 +239,13 @@ int statement_simple_execute(struct grub2_script *script,
 	if (!st->argv->argc)
 		return 0;
 
-	cmd = script_lookup_command(script, st->argv->argv[0]);
-	if (!cmd) {
-		fprintf(stderr, "undefined command '%s'\n", st->argv->argv[0]);
+	entry = script_lookup_function(script, st->argv->argv[0]);
+	if (!entry) {
+		fprintf(stderr, "undefined function '%s'\n", st->argv->argv[0]);
 		return 0;
 	}
 
-	rc = cmd->exec(script, st->argv->argc, st->argv->argv);
+	rc = entry->fn(script, entry->data, st->argv->argc, st->argv->argv);
 
 	return rc;
 }
@@ -290,23 +310,17 @@ static void init_env(struct grub2_script *script)
 	list_add(&script->environment, &env->list);
 }
 
-struct grub2_command *script_lookup_command(struct grub2_script *script,
-		const char *name)
+void script_register_function(struct grub2_script *script,
+		const char *name, grub2_function fn,
+		void *data)
 {
-	struct grub2_command *command;
-
-	list_for_each_entry(&script->commands, command, list) {
-		if (!strcmp(command->name, name))
-			return command;
-	}
+	struct grub2_symtab_entry *entry;
 
-	return NULL;
-}
-
-void script_register_command(struct grub2_script *script,
-		struct grub2_command *command)
-{
-	list_add(&script->commands, &command->list);
+	entry = talloc(script, struct grub2_symtab_entry);
+	entry->fn = fn;
+	entry->name = name;
+	entry->data = data;
+	list_add(&script->symtab, &entry->list);
 }
 
 
@@ -326,7 +340,7 @@ struct grub2_script *create_script(struct grub2_parser *parser,
 	script->ctx = ctx;
 	script->opt = NULL;
 
-	list_init(&script->commands);
+	list_init(&script->symtab);
 	register_builtins(script);
 
 	return script;