discover/grub2: Add initial execution code

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

3 files changed, 76 insertions, 3 deletions

diff --git a/discover/grub2/grub2.h b/discover/grub2/grub2.h
index 33180d4..07a1e6c 100644
--- a/discover/grub2/grub2.h
+++ b/discover/grub2/grub2.h
@@ -5,7 +5,7 @@
 #include <stdbool.h>
 #include <list/list.h>
 
-struct grub2_parser;
+struct grub2_script;
 
 struct grub2_word {
 	const char		*text;
@@ -31,6 +31,8 @@ struct grub2_statement {
 		STMT_TYPE_IF,
 		STMT_TYPE_BLOCK,
 	} type;
+	int			(*exec)(struct grub2_script *,
+					struct grub2_statement *);
 };
 
 struct grub2_statement_simple {
@@ -96,6 +98,12 @@ void argv_append(struct grub2_argv *argv, struct grub2_word *word);
 void word_append(struct grub2_word *w1, struct grub2_word *w2);
 
 /* script interface */
+void script_execute(struct grub2_script *script);
+
+int statement_simple_execute(struct grub2_script *script,
+		struct grub2_statement *statement);
+int statement_if_execute(struct grub2_script *script,
+		struct grub2_statement *statement);
 
 struct grub2_script *create_script(void *ctx);
 
diff --git a/discover/grub2/parser-api.c b/discover/grub2/parser-api.c
index d3bec3d..9ccf15e 100644
--- a/discover/grub2/parser-api.c
+++ b/discover/grub2/parser-api.c
@@ -17,6 +17,7 @@ struct grub2_statement *create_statement_simple(struct grub2_parser *parser,
 	struct grub2_statement_simple *stmt =
 		talloc(parser, struct grub2_statement_simple);
 	stmt->st.type = STMT_TYPE_SIMPLE;
+	stmt->st.exec = statement_simple_execute;
 	stmt->argv = argv;
 	return &stmt->st;
 }
@@ -27,6 +28,7 @@ struct grub2_statement *create_statement_menuentry(struct grub2_parser *parser,
 	struct grub2_statement_menuentry *stmt =
 		talloc(parser, struct grub2_statement_menuentry);
 	stmt->st.type = STMT_TYPE_MENUENTRY;
+	stmt->st.exec = NULL;
 	stmt->argv = argv;
 	stmt->statements = stmts;
 	return &stmt->st;
@@ -40,6 +42,7 @@ struct grub2_statement *create_statement_if(struct grub2_parser *parser,
 	struct grub2_statement_if *stmt =
 		talloc(parser, struct grub2_statement_if);
 	stmt->st.type = STMT_TYPE_IF;
+	stmt->st.exec = statement_if_execute;
 	stmt->condition = condition;
 	stmt->true_case = true_case;
 	stmt->false_case = false_case;
@@ -52,6 +55,7 @@ struct grub2_statement *create_statement_block(struct grub2_parser *parser,
 	struct grub2_statement_block *stmt =
 		talloc(parser, struct grub2_statement_block);
 	stmt->st.type = STMT_TYPE_BLOCK;
+	stmt->st.exec = NULL;
 	stmt->statements = stmts;
 	return &stmt->st;
 }
diff --git a/discover/grub2/script.c b/discover/grub2/script.c
index 067b0c9..b6d3221 100644
--- a/discover/grub2/script.c
+++ b/discover/grub2/script.c
@@ -7,6 +7,11 @@
 
 #include "grub2.h"
 
+#define to_stmt_simple(stmt) \
+	container_of(stmt, struct grub2_statement_simple, st)
+#define to_stmt_if(stmt) \
+	container_of(stmt, struct grub2_statement_if, st)
+
 struct env_entry {
 	const char		*name;
 	const char		*value;
@@ -39,12 +44,13 @@ static bool expand_word(struct grub2_script *script, struct grub2_word *word)
 	src = word->text;
 
 	n = regexec(&script->var_re, src, 1, &match, 0);
-	if (n == 0)
+	printf("%s %s: %d\n", __func__, word->text, n);
+	if (n != 0)
 		return false;
 
 	val = env_lookup(script, src + match.rm_so,
 				 match.rm_eo - match.rm_so);
-	if (val)
+	if (!val)
 		val = "";
 
 	dest = talloc_strndup(script, src, match.rm_so);
@@ -74,6 +80,61 @@ static void process_expansions(struct grub2_script *script,
 	}
 }
 
+int statements_execute(struct grub2_script *script,
+		struct grub2_statements *stmts)
+{
+	struct grub2_statement *stmt;
+	int rc = 0;
+
+	list_for_each_entry(&stmts->list, stmt, list) {
+		if (stmt->exec)
+			rc = stmt->exec(script, stmt);
+		printf("%s(%p)\n", __func__, stmt);
+	}
+	return rc;
+}
+
+int statement_simple_execute(struct grub2_script *script,
+		struct grub2_statement *statement)
+{
+	struct grub2_statement_simple *st = to_stmt_simple(statement);
+
+	if (!st->argv)
+		return 0;
+
+	process_expansions(script, st->argv);
+
+	return 0;
+}
+
+int statement_if_execute(struct grub2_script *script,
+		struct grub2_statement *statement)
+{
+	struct grub2_statement_if *st = to_stmt_if(statement);
+	struct grub2_statements *case_stmts;
+	int rc;
+
+	rc = st->condition->exec(script, st->condition);
+
+	if (rc == 0)
+		case_stmts = st->true_case;
+	else
+		case_stmts = st->false_case;
+
+	if (case_stmts)
+		statements_execute(script, case_stmts);
+	else
+		rc = 0;
+
+	return rc;
+}
+
+
+void script_execute(struct grub2_script *script)
+{
+	statements_execute(script, script->statements);
+}
+
 static int script_destroy(void *p)
 {
 	struct grub2_script *script = p;