Changeset 96c04e4 for src

Timestamp:

May 28, 2024, 11:38:25 AM (7 months ago)

Author:

Andrew Beach <ajbeach@…>

Branches:

master

Children:

91b9e10

Parents:

66286aa

Message:

Simplified the visit children guard to use a ValueGuardPtr?. For consistency, so all three guards use the same pattern, I also updated the value guard, which is a side ways step in complexity (although less of it is under macros now).

Location:

src/AST

Files:

• Pass.hpp (modified) (1 diff)
• Pass.impl.hpp (modified) (1 diff)
• Pass.proto.hpp (modified) (5 diffs)

src/AST/Pass.hpp

@@ -351 +351 @@
         };
 
-        template< typename core_t>
-        friend auto __pass::at_cleanup( core_t & core, int ) -> decltype( &core.at_cleanup );
+        template< typename core_t >
+        friend auto __pass::make_value_guard( core_t & core, int ) -> decltype( value_guard( core.at_cleanup ) );
 public:
 

src/AST/Pass.impl.hpp

@@ -27 +27 @@
         using namespace ast; \
         /* back-up the last known code location */ \
-        __attribute__((unused)) auto loc_guard = ast::__pass::make_location_guard( core, node, 0 ); \
+        __attribute__((unused)) auto guard0 = __pass::make_location_guard( core, node, 0 ); \
         /* back-up the visit children */ \
-        __attribute__((unused)) ast::__pass::visit_children_guard guard1( ast::__pass::visit_children(core, 0) ); \
+        __attribute__((unused)) auto guard1 = __pass::make_visit_children_guard( core, 0 ); \
         /* setup the scope for passes that want to run code at exit */ \
-        __attribute__((unused)) ast::__pass::guard_value          guard2( ast::__pass::at_cleanup    (core, 0) ); \
+        __attribute__((unused)) auto guard2 = __pass::make_value_guard( core, 0 ); \
         /* begin tracing memory allocation if requested by this pass */ \
         __pass::beginTrace( core, 0 ); \

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
-class guard_value {
+/// Replaces guards we don't want to use.
+struct empty_guard {
+};
+
+/// Implementation of the value guard. Created inside the visit scope.
+class value_guard {
 public:
         /// Push onto the cleanup
-        guard_value( at_cleanup_t * at_cleanup ) {
-                if( at_cleanup ) {
-                        *at_cleanup = [this]( cleanup_func_t && func, void* val ) {
-                                push( std::move( func ), val );
-                        };
-                }
-        }
-
-        ~guard_value() {
+        value_guard( at_cleanup_t & at_cleanup ) {
+                at_cleanup = [this]( cleanup_func_t && func, void* val ) {
+                        push( std::move( func ), val );
+                };
+        }
+
+        ~value_guard() {
                 while( !cleanups.empty() ) {
                         auto& cleanup = cleanups.top();
@@ -74 +75 @@
 
         std::stack< cleanup_t, std::vector<cleanup_t> > cleanups;
-};
-
-// Guard structure implementation for whether or not children should be visited
-class visit_children_guard {
-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() {
-                if ( m_ref ) { *m_ref = m_val; }
-        }
-
-private:
-        bool * m_ref;
-        bool   m_val;
 };
 
@@ -280 +262 @@
 FIELD_PTR( declsToAddAfter , std::list< ast::ptr< ast::Decl > > )
 FIELD_PTR( visit_children, bool )
-FIELD_PTR( at_cleanup, __pass::at_cleanup_t )
 FIELD_PTR( visitor, ast::Pass<core_t> * const )
 FIELD_PTR( translationUnit, const TranslationUnit * )
@@ -314 +295 @@
 }
 
+// These are the guards declared at the beginning of a visit.
+// They are replaced with empty objects when not used.
+
 template< typename core_t, typename node_t >
-static auto make_location_guard( core_t & core, node_t * node, int )
+static inline auto make_location_guard( core_t & core, node_t * node, int )
                 -> decltype( node->location, ValueGuardPtr<const CodeLocation *>( &core.location ) ) {
         ValueGuardPtr<const CodeLocation *> guard( &core.location );
@@ -323 +307 @@
 
 template< typename core_t, typename node_t >
-static auto make_location_guard( core_t &, node_t *, long ) -> int {
-        return 0;
+static inline empty_guard make_location_guard( core_t &, node_t *, long ) {
+        return empty_guard();
+}
+
+template< typename core_t >
+static inline auto make_visit_children_guard( core_t & core, int )
+                -> decltype( ValueGuardPtr<bool>( &core.visit_children ) ) {
+        ValueGuardPtr<bool> guard( &core.visit_children );
+        core.visit_children = true;
+        return guard;
+}
+
+template< typename core_t >
+static inline empty_guard make_visit_children_guard( core_t &, long ) {
+        return empty_guard();
+}
+
+template< typename core_t >
+static inline auto make_value_guard( core_t & core, int )
+                -> decltype( value_guard( core.at_cleanup ) ) {
+        // Requires guaranteed copy elision:
+        return value_guard( core.at_cleanup );
+}
+
+template< typename core_t >
+static inline empty_guard make_value_guard( core_t &, long ) {
+        return empty_guard();
 }