Changes in / [69dd8e6:ac16a55]

Location:

src/AST

Files:

• Pass.hpp (modified) (2 diffs)
• Pass.proto.hpp (modified) (4 diffs)

src/AST/Pass.hpp

@@ -233 +233 @@
 private:
 
-        bool __visit_children() { bool * ptr = __pass::visit_children(core, 0); return ptr ? *ptr : true; }
+        bool __visit_children() { __pass::bool_ref * ptr = __pass::visit_children(core, 0); return ptr ? *ptr : true; }
 
 private:
@@ -342 +342 @@
 /// set visit_children false of all child nodes should be ignored
 struct WithShortCircuiting {
-        bool visit_children;
+        __pass::bool_ref visit_children;
 };
 

src/AST/Pass.proto.hpp

@@ -40 +40 @@
 typedef std::function<void( cleanup_func_t, void * )> at_cleanup_t;
 
-/// Implementation of the guard value
-/// Created inside the visit scope
+// boolean reference that may be null
+// either refers to a boolean value or is null and returns true
+class bool_ref {
+public:
+        bool_ref() = default;
+        ~bool_ref() = default;
+
+        operator bool() { return m_ref ? *m_ref : true; }
+        bool operator=( bool val ) { assert(m_ref); return *m_ref = val; }
+
+private:
+
+        friend class visit_children_guard;
+
+        bool * set( bool * val ) {
+                bool * prev = m_ref;
+                m_ref = val;
+                return prev;
+        }
+
+        bool * m_ref = nullptr;
+};
+
+// Implementation of the guard value
+// Created inside the visit scope
 class guard_value {
 public:
@@ -80 +103 @@
 public:
 
-        visit_children_guard( bool * ref ) :
-                m_ref( ref ), m_val( true )
-        {
-                if ( m_ref ) { m_val = *m_ref; *m_ref = true; }
-        }
+        visit_children_guard( bool_ref * ref )
+                : m_val ( true )
+                , m_prev( ref ? ref->set( &m_val ) : nullptr )
+                , m_ref ( ref )
+        {}
 
         ~visit_children_guard() {
-                if ( m_ref ) { *m_ref = m_val; }
-        }
+                if( m_ref ) {
+                        m_ref->set( m_prev );
+                }
+        }
+
+        operator bool() { return m_val; }
 
 private:
-        bool * m_ref;
-        bool   m_val;
+        bool       m_val;
+        bool     * m_prev;
+        bool_ref * m_ref;
+};
+
+/// "Short hand" to check if this is a valid previsit function
+/// Mostly used to make the static_assert look (and print) prettier
+template<typename core_t, typename node_t>
+struct is_valid_previsit {
+        using ret_t = decltype( std::declval<core_t*>()->previsit( std::declval<const node_t *>() ) );
+
+        static constexpr bool value = std::is_void< ret_t >::value ||
+                std::is_base_of<const node_t, typename std::remove_pointer<ret_t>::type >::value;
 };
 
@@ -189 +227 @@
                 // but also contain the new values.
         }
-};
-
-/// "Short hand" to check if this is a valid previsit function
-/// Mostly used to make the static_assert look (and print) prettier
-template<typename core_t, typename node_t>
-struct is_valid_previsit {
-        using ret_t = decltype( std::declval<core_t*>()->previsit( std::declval<const node_t *>() ) );
-
-        static constexpr bool value = std::is_void< ret_t >::value ||
-                std::is_base_of<const node_t, typename std::remove_pointer<ret_t>::type >::value;
 };
 
@@ -279 +307 @@
 FIELD_PTR( declsToAddBefore, std::list< ast::ptr< ast::Decl > > )
 FIELD_PTR( declsToAddAfter , std::list< ast::ptr< ast::Decl > > )
-FIELD_PTR( visit_children, bool )
+FIELD_PTR( visit_children, __pass::bool_ref )
 FIELD_PTR( at_cleanup, __pass::at_cleanup_t )
 FIELD_PTR( visitor, ast::Pass<core_t> * const )