Add checks for unused variables

1 files changed, 3 insertions, 2 deletions

diff --git a/src/ast.h b/src/ast.h
index b852da2a..b6930ab7 100644
--- a/src/ast.h
+++ b/src/ast.h
@@ -488,6 +488,7 @@ void visit_topologically(ast_list_t *ast, Closure_t fn);
 CONSTFUNC bool is_update_assignment(ast_t *ast);
 CONSTFUNC ast_e binop_tag(ast_e tag);
 CONSTFUNC bool is_binary_operation(ast_t *ast);
-void ast_visit(ast_t *ast, void (*visitor)(ast_t *, void *), void *userdata);
-void type_ast_visit(ast_t *ast, void (*visitor)(type_ast_t *, void *), void *userdata);
+typedef enum { VISIT_STOP, VISIT_PROCEED } visit_behavior_t;
+void ast_visit(ast_t *ast, visit_behavior_t (*visitor)(ast_t *, void *), void *userdata);
+void type_ast_visit(ast_t *ast, visit_behavior_t (*visitor)(type_ast_t *, void *), void *userdata);
 OptionalText_t ast_metadata(ast_t *ast, const char *key);