filter out empty nodes from statement list

+ Fixes tail call analysis that was accidentally broken by
  64146b46da45ce69ab380add00459f7b60fe9196

+ Kind of wasteful to first allocate empty node and then just throw it
  away, but I don't have any better ideas at the moment

3 files changed, 18 insertions, 1 deletions

diff --git a/include/fwd/ast.h b/include/fwd/ast.h
index 1d784f1..f550647 100644
--- a/include/fwd/ast.h
+++ b/include/fwd/ast.h
@@ -699,6 +699,7 @@ int equiv_node_lists(struct ast *c1, struct ast *c2);
 struct ast *reverse_ast_list(struct ast *root);
 struct type *reverse_type_list(struct type *root);
 
+struct ast *filter_empty(struct ast *root);
 void fix_closures(struct ast *root);
 
 #define foreach_node(iter, nodes) \
diff --git a/src/ast.c b/src/ast.c
index a39cb94..d7d97e0 100644
--- a/src/ast.c
+++ b/src/ast.c
@@ -567,6 +567,19 @@ struct type *reverse_type_list(struct type *root)
 	return new_root;
 }
 
+struct ast *filter_empty(struct ast *root)
+{
+	struct ast *ret = root;
+	while (root) {
+		if (root->n && root->n->k == AST_EMPTY)
+			root->n = root->n->n;
+
+		root = root->n;
+	}
+
+	return ret;
+}
+
 void fix_closures(struct ast *root)
 {
 	while (root) {
diff --git a/src/parser.y b/src/parser.y
index dad3210..6210a95 100644
--- a/src/parser.y
+++ b/src/parser.y
@@ -454,7 +454,10 @@ rev_statements
 	| statement
 
 statements
-	: rev_statements { $$ = reverse_ast_list($1); fix_closures($$); }
+	: rev_statements {
+		$$ = filter_empty(reverse_ast_list($1));
+		fix_closures($$);
+	}
 
 opt_statements
 	: statements