source: src/Common/PassVisitor.impl.h@ 7ad6b6d

#pragma once
// IWYU pragma: private, include "PassVisitor.h"

#define VISIT_START( node )                                     \
        __attribute__((unused))                                   \
        ChildrenGuard children_guard( get_visit_children_ptr() ); \
        __attribute__((unused))                                   \
        guard_value_impl guard( at_cleanup_impl(pass, 0) );       \
        call_previsit( node );                                    \

#define VISIT_END( node )                       \
        call_postvisit( node );                   \

#define MUTATE_START( node )                                    \
        __attribute__((unused))                                   \
        ChildrenGuard children_guard( get_visit_children_ptr() ); \
        __attribute__((unused))                                   \
        guard_value_impl guard( at_cleanup_impl(pass, 0) );       \
        call_premutate( node );                                   \

#define MUTATE_END( type, node )                \
        return call_postmutate< type * >( node ); \


#define VISIT_BODY( node )          \
        VISIT_START( node );          \
        if( children_guard ) {        \
                Visitor::visit( node ); \
        }                             \
        VISIT_END( node );            \


#define MUTATE_BODY( type, node )    \
        MUTATE_START( node );          \
        if( children_guard ) {         \
                Mutator::mutate( node ); \
        }                              \
        MUTATE_END( type, node );      \



template<typename T>
static inline bool empty( T * ptr ) {
        return !ptr || ptr->empty();
}

typedef std::list< Statement   * > StmtList_t;
typedef std::list< Declaration * > DeclList_t;

template<typename iterator_t>
static inline void splice( iterator_t it, DeclList_t * decls ) {
        std::transform(
                decls->begin(),
                decls->end(),
                it,
                [](Declaration * decl) -> auto {
                        return new DeclStmt( decl );
                }
        );
        decls->clear();
}

template< typename pass_type >
inline void acceptAll( std::list< Declaration* > &decls, PassVisitor< pass_type >& visitor ) {
        DeclList_t* beforeDecls = visitor.get_beforeDecls();
        DeclList_t* afterDecls  = visitor.get_afterDecls();
        SemanticError errors;

        for ( std::list< Declaration* >::iterator i = decls.begin(); ; ++i ) {
                // splice in new declarations after previous decl
                if ( !empty( afterDecls ) ) { decls.splice( i, *afterDecls ); }

                if ( i == decls.end() ) break;

                try {
                        // run visitor on declaration
                        maybeAccept_impl( *i, visitor );
                } catch( SemanticError &e ) {
                        e.set_location( (*i)->location );
                        errors.append( e );
                }

                // splice in new declarations before current decl
                if ( !empty( beforeDecls ) ) { decls.splice( i, *beforeDecls ); }
        }
        if ( ! errors.isEmpty() ) {
                throw errors;
        }
}

template< typename pass_type >
inline void mutateAll( std::list< Declaration* > &decls, PassVisitor< pass_type >& mutator ) {
        DeclList_t* beforeDecls = mutator.get_beforeDecls();
        DeclList_t* afterDecls  = mutator.get_afterDecls();
        SemanticError errors;

        for ( std::list< Declaration* >::iterator i = decls.begin(); ; ++i ) {
                // splice in new declarations after previous decl
                if ( !empty( afterDecls ) ) { decls.splice( i, *afterDecls ); }

                if ( i == decls.end() ) break;
                try {
                        // run mutator on declaration
                        maybeMutate_impl( *i, mutator );
                } catch( SemanticError &e ) {
                        e.set_location( (*i)->location );
                        errors.append( e );
                }

                // splice in new declarations before current decl
                if ( !empty( beforeDecls ) ) { decls.splice( i, *beforeDecls ); }
        }
        if ( ! errors.isEmpty() ) {
                throw errors;
        }
}

template< typename TreeType, typename pass_type >
inline void maybeAccept_impl( TreeType * tree, PassVisitor< pass_type > & visitor ) {
        if ( ! visitor.get_visit_children() ) return;
        if ( tree ) {
                tree->accept( visitor );
        }
}

template< typename Container, typename pass_type >
inline void maybeAccept_impl( Container & container, PassVisitor< pass_type > & visitor ) {
        if ( ! visitor.get_visit_children() ) return;
        SemanticError errors;
        for ( typename Container::iterator i = container.begin(); i != container.end(); ++i ) {
                try {
                        if ( *i ) {
                                (*i)->accept( visitor );
                        }
                } catch( SemanticError &e ) {
                        e.set_location( (*i)->location );
                        errors.append( e );
                }
        }
        if ( ! errors.isEmpty() ) {
                throw errors;
        }
}

template< typename TreeType, typename pass_type >
inline void maybeMutate_impl( TreeType *& tree, PassVisitor< pass_type > & mutator ) {
        if ( ! mutator.get_visit_children() ) return;

        if ( tree ) {
                tree = strict_dynamic_cast< TreeType * >( tree->acceptMutator( mutator ) );
        }
}

template< typename Container, typename pass_type >
inline void maybeMutate_impl( Container & container, PassVisitor< pass_type > & mutator ) {
        if ( ! mutator.get_visit_children() ) return;
        SemanticError errors;
        for ( typename Container::iterator i = container.begin(); i != container.end(); ++i ) {
                try {
                        if ( *i ) {
                                *i = dynamic_cast< typename Container::value_type >( (*i)->acceptMutator( mutator ) );
                                assert( *i );
                        } // if
                } catch( SemanticError &e ) {
                        e.set_location( (*i)->location );
                        errors.append( e );
                } // try
        } // for
        if ( ! errors.isEmpty() ) {
                throw errors;
        } // if
}

template< typename pass_type >
template< typename func_t >
void PassVisitor< pass_type >::handleStatementList( std::list< Statement * > & statements, func_t func ) {
        if ( ! get_visit_children() ) return;
        SemanticError errors;

        // don't want statements from outer CompoundStmts to be added to this CompoundStmt
        ValueGuardPtr< StmtList_t > oldBeforeStmts( get_beforeStmts() );
        ValueGuardPtr< StmtList_t > oldAfterStmts ( get_afterStmts () );
        ValueGuardPtr< DeclList_t > oldBeforeDecls( get_beforeDecls() );
        ValueGuardPtr< DeclList_t > oldAfterDecls ( get_afterDecls () );

        StmtList_t* beforeStmts = get_beforeStmts();
        StmtList_t* afterStmts  = get_afterStmts();
        DeclList_t* beforeDecls = get_beforeDecls();
        DeclList_t* afterDecls  = get_afterDecls();

        for ( std::list< Statement* >::iterator i = statements.begin(); i != statements.end(); ++i ) {

                if ( !empty( afterDecls ) ) { splice( std::inserter( statements, i ), afterDecls ); }
                if ( !empty( afterStmts ) ) { statements.splice( i, *afterStmts ); }

                try {
                        func( *i );
                        assert(( empty( beforeStmts ) && empty( afterStmts ))
                            || ( empty( beforeDecls ) && empty( afterDecls )) );

                } catch ( SemanticError &e ) {
                        e.set_location( (*i)->location );
                        errors.append( e );
                }

                if ( !empty( beforeDecls ) ) { splice( std::inserter( statements, i ), beforeDecls ); }
                if ( !empty( beforeStmts ) ) { statements.splice( i, *beforeStmts ); }
        }

        if ( !empty( afterDecls ) ) { splice( std::back_inserter( statements ), afterDecls); }
        if ( !empty( afterStmts ) ) { statements.splice( statements.end(), *afterStmts ); }
        if ( !errors.isEmpty() ) { throw errors; }
}

template< typename pass_type >
void PassVisitor< pass_type >::visitStatementList( std::list< Statement * > & statements ) {
        handleStatementList( statements, [this]( Statement * stmt) {
                maybeAccept_impl( stmt, *this );
        });
}

template< typename pass_type >
void PassVisitor< pass_type >::mutateStatementList( std::list< Statement * > & statements ) {
        handleStatementList( statements, [this]( Statement *& stmt) {
                maybeMutate_impl( stmt, *this );
        });
}


template< typename pass_type >
template< typename func_t >
Statement * PassVisitor< pass_type >::handleStatement( Statement * stmt, func_t func ) {
        if ( ! get_visit_children() ) return stmt;

        // don't want statements from outer CompoundStmts to be added to this CompoundStmt
        ValueGuardPtr< TypeSubstitution * >  oldEnv        ( get_env_ptr    () );
        ValueGuardPtr< DeclList_t >          oldBeforeDecls( get_beforeDecls() );
        ValueGuardPtr< DeclList_t >          oldAfterDecls ( get_afterDecls () );
        ValueGuardPtr< StmtList_t >          oldBeforeStmts( get_beforeStmts() );
        ValueGuardPtr< StmtList_t >          oldAfterStmts ( get_afterStmts () );

        Statement *newStmt = func( stmt );

        StmtList_t* beforeStmts = get_beforeStmts();
        StmtList_t* afterStmts  = get_afterStmts();
        DeclList_t* beforeDecls = get_beforeDecls();
        DeclList_t* afterDecls  = get_afterDecls();

        if( empty(beforeStmts) && empty(afterStmts) && empty(beforeDecls) && empty(afterDecls) ) { return newStmt; }
        assert(( empty( beforeStmts ) && empty( afterStmts ))
            || ( empty( beforeDecls ) && empty( afterDecls )) );

        CompoundStmt *compound = new CompoundStmt();
        if( !empty(beforeDecls) ) { splice( std::back_inserter( compound->get_kids() ), beforeDecls ); }
        if( !empty(beforeStmts) ) { compound->get_kids().splice( compound->get_kids().end(), *beforeStmts ); }
        compound->get_kids().push_back( newStmt );
        if( !empty(afterDecls) ) { splice( std::back_inserter( compound->get_kids() ), afterDecls ); }
        if( !empty(afterStmts) ) { compound->get_kids().splice( compound->get_kids().end(), *afterStmts ); }
        return compound;
}

template< typename pass_type >
Statement * PassVisitor< pass_type >::visitStatement( Statement * stmt ) {
        return handleStatement( stmt, [this]( Statement * stmt ) {
                maybeAccept_impl( stmt, *this );
                return stmt;
        });
}

template< typename pass_type >
Statement * PassVisitor< pass_type >::mutateStatement( Statement * stmt ) {
        return handleStatement( stmt, [this]( Statement * stmt ) {
                maybeMutate_impl( stmt, *this );
                return stmt;
        });
}

template< typename pass_type >
template< typename func_t >
Expression * PassVisitor< pass_type >::handleExpression( Expression * expr, func_t func ) {
        if ( ! get_visit_children() ) return expr;
        if( !expr ) return nullptr;

        auto env_ptr = get_env_ptr();
        if ( env_ptr && expr->get_env() ) {
                *env_ptr = expr->get_env();
        }

        // should env be moved onto the result of the mutate?
        return func( expr );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::visitExpression( Expression * expr ) {
        return handleExpression(expr, [this]( Expression * expr ) {
                maybeAccept_impl( expr, *this );
                return expr;
        });
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutateExpression( Expression * expr ) {
        return handleExpression(expr, [this]( Expression * expr ) {
                maybeMutate_impl( expr, *this );
                return expr;
        });
}

template< typename TreeType, typename VisitorType >
inline void indexerScopedAccept( TreeType * tree, VisitorType & visitor ) {
        if ( ! visitor.get_visit_children() ) return;
        auto guard = makeFuncGuard(
                [&visitor]() { visitor.indexerScopeEnter(); },
                [&visitor]() { visitor.indexerScopeLeave(); }
        );
        maybeAccept_impl( tree, visitor );
}

template< typename TreeType, typename MutatorType >
inline void indexerScopedMutate( TreeType *& tree, MutatorType & mutator ) {
        if ( ! mutator.get_visit_children() ) return;
        auto guard = makeFuncGuard(
                [&mutator]() { mutator.indexerScopeEnter(); },
                [&mutator]() { mutator.indexerScopeLeave(); }
        );
        maybeMutate_impl( tree, mutator );
}

//------------------------------------------------------------------------------------------------------------------------------------------------------------------------
//========================================================================================================================================================================
//========================================================================================================================================================================
//========================================================================================================================================================================
//========================================================================================================================================================================
//========================================================================================================================================================================
//------------------------------------------------------------------------------------------------------------------------------------------------------------------------

// A NOTE ON THE ORDER OF TRAVERSAL
//
// Types and typedefs have their base types visited before they are added to the type table.  This is ok, since there is
// no such thing as a recursive type or typedef.
//
//             typedef struct { T *x; } T; // never allowed
//
// for structs/unions, it is possible to have recursion, so the decl should be added as if it's incomplete to begin, the
// members are traversed, and then the complete type should be added (assuming the type is completed by this particular
// declaration).
//
//             struct T { struct T *x; }; // allowed
//
// It is important to add the complete type to the symbol table *after* the members/base has been traversed, since that
// traversal may modify the definition of the type and these modifications should be visible when the symbol table is
// queried later in this pass.
//
// TODO: figure out whether recursive contexts are sensible/possible/reasonable.

//--------------------------------------------------------------------------
// ObjectDecl
template< typename pass_type >
void PassVisitor< pass_type >::visit( ObjectDecl * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->type         , *this );
        maybeAccept_impl   ( node->init         , *this );
        maybeAccept_impl   ( node->bitfieldWidth, *this );
        maybeAccept_impl   ( node->attributes   , *this );

        indexerAddId( node );

        VISIT_END( node );
}

template< typename pass_type >
DeclarationWithType * PassVisitor< pass_type >::mutate( ObjectDecl * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->type         , *this );
        maybeMutate_impl   ( node->init         , *this );
        maybeMutate_impl   ( node->bitfieldWidth, *this );
        maybeMutate_impl   ( node->attributes   , *this );

        indexerAddId( node );

        MUTATE_END( DeclarationWithType, node );
}

//--------------------------------------------------------------------------
// FunctionDecl
template< typename pass_type >
void PassVisitor< pass_type >::visit( FunctionDecl * node ) {
        VISIT_START( node );

        indexerAddId( node );

        maybeAccept_impl( node->withExprs, *this );
        {
                // with clause introduces a level of scope (for the with expression members).
                // with clause exprs are added to the indexer before parameters so that parameters
                // shadow with exprs and not the other way around.
                auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                indexerAddWith( node->withExprs );
                {
                        auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                        // implicit add __func__ identifier as specified in the C manual 6.4.2.2
                        static ObjectDecl func(
                                "__func__", noStorageClasses, LinkageSpec::C, nullptr,
                                new ArrayType( Type::Qualifiers(), new BasicType( Type::Qualifiers( Type::Const ), BasicType::Char ), nullptr, true, false ),
                                nullptr
                        );
                        indexerAddId( &func );
                        maybeAccept_impl( node->type, *this );
                        maybeAccept_impl( node->statements, *this );
                        maybeAccept_impl( node->attributes, *this );
                }
        }

        VISIT_END( node );
}

template< typename pass_type >
DeclarationWithType * PassVisitor< pass_type >::mutate( FunctionDecl * node ) {
        MUTATE_START( node );

        indexerAddId( node );

        {
                // with clause introduces a level of scope (for the with expression members).
                // with clause exprs are added to the indexer before parameters so that parameters
                // shadow with exprs and not the other way around.
                auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                indexerAddWith( node->withExprs );
                {
                        auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                        // implicit add __func__ identifier as specified in the C manual 6.4.2.2
                        static ObjectDecl func(
                                "__func__", noStorageClasses, LinkageSpec::C, nullptr,
                                new ArrayType( Type::Qualifiers(), new BasicType( Type::Qualifiers( Type::Const ), BasicType::Char ), nullptr, true, false ),
                                nullptr
                        );
                        indexerAddId( &func );
                        maybeMutate_impl( node->type, *this );
                        maybeMutate_impl( node->statements, *this );
                        maybeMutate_impl( node->attributes, *this );
                }
        }

        MUTATE_END( DeclarationWithType, node );
}

//--------------------------------------------------------------------------
// StructDecl
template< typename pass_type >
void PassVisitor< pass_type >::visit( StructDecl * node ) {
        VISIT_START( node );

        // make up a forward declaration and add it before processing the members
        // needs to be on the heap because addStruct saves the pointer
        indexerAddStructFwd( node );

        {
                auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                maybeAccept_impl( node->parameters, *this );
                maybeAccept_impl( node->members   , *this );
        }

        // this addition replaces the forward declaration
        indexerAddStruct( node );

        VISIT_END( node );
}

template< typename pass_type >
Declaration * PassVisitor< pass_type >::mutate( StructDecl * node ) {
        MUTATE_START( node );

        // make up a forward declaration and add it before processing the members
        // needs to be on the heap because addStruct saves the pointer
        indexerAddStructFwd( node );

        {
                auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                maybeMutate_impl( node->parameters, *this );
                maybeMutate_impl( node->members   , *this );
        }

        // this addition replaces the forward declaration
        indexerAddStruct( node );

        MUTATE_END( Declaration, node );
}

//--------------------------------------------------------------------------
// UnionDecl
template< typename pass_type >
void PassVisitor< pass_type >::visit( UnionDecl * node ) {
        VISIT_START( node );

        // make up a forward declaration and add it before processing the members
        indexerAddUnionFwd( node );

        {
                auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                maybeAccept_impl( node->parameters, *this );
                maybeAccept_impl( node->members   , *this );
        }

        indexerAddUnion( node );

        VISIT_END( node );
}

template< typename pass_type >
Declaration * PassVisitor< pass_type >::mutate( UnionDecl * node ) {
        MUTATE_START( node );

        // make up a forward declaration and add it before processing the members
        indexerAddUnionFwd( node );

        {
                auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                maybeMutate_impl( node->parameters, *this );
                maybeMutate_impl( node->members   , *this );
        }

        indexerAddUnion( node );

        MUTATE_END( Declaration, node );
}

//--------------------------------------------------------------------------
// EnumDecl
template< typename pass_type >
void PassVisitor< pass_type >::visit( EnumDecl * node ) {
        VISIT_START( node );

        indexerAddEnum( node );

        // unlike structs, traits, and unions, enums inject their members into the global scope
        maybeAccept_impl( node->parameters, *this );
        maybeAccept_impl( node->members   , *this );

        VISIT_END( node );
}

template< typename pass_type >
Declaration * PassVisitor< pass_type >::mutate( EnumDecl * node ) {
        MUTATE_START( node );

        indexerAddEnum( node );

        // unlike structs, traits, and unions, enums inject their members into the global scope
        maybeMutate_impl( node->parameters, *this );
        maybeMutate_impl( node->members   , *this );

        MUTATE_END( Declaration, node );
}

//--------------------------------------------------------------------------
// TraitDecl
template< typename pass_type >
void PassVisitor< pass_type >::visit( TraitDecl * node ) {
        VISIT_START( node );

        {
                auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                maybeAccept_impl( node->parameters, *this );
                maybeAccept_impl( node->members   , *this );
        }

        indexerAddTrait( node );

        VISIT_END( node );
}

template< typename pass_type >
Declaration * PassVisitor< pass_type >::mutate( TraitDecl * node ) {
        MUTATE_START( node );

        {
                auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                maybeMutate_impl( node->parameters, *this );
                maybeMutate_impl( node->members   , *this );
        }

        indexerAddTrait( node );

        MUTATE_END( Declaration, node );
}

//--------------------------------------------------------------------------
// TypeDecl
template< typename pass_type >
void PassVisitor< pass_type >::visit( TypeDecl * node ) {
        VISIT_START( node );

        {
                auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                maybeAccept_impl( node->parameters, *this );
                maybeAccept_impl( node->base      , *this );
        }

        // see A NOTE ON THE ORDER OF TRAVERSAL, above
        // note that assertions come after the type is added to the symtab, since they are not part of the type proper
        // and may depend on the type itself
        indexerAddType( node );

        maybeAccept_impl( node->assertions, *this );

        indexerScopedAccept( node->init, *this );

        VISIT_END( node );
}

template< typename pass_type >
Declaration * PassVisitor< pass_type >::mutate( TypeDecl * node ) {
        MUTATE_START( node );

        {
                auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                maybeMutate_impl( node->parameters, *this );
                maybeMutate_impl( node->base      , *this );
        }

        // see A NOTE ON THE ORDER OF TRAVERSAL, above
        // note that assertions come after the type is added to the symtab, since they are not part of the type proper
        // and may depend on the type itself
        indexerAddType( node );

        maybeMutate_impl( node->assertions, *this );

        indexerScopedMutate( node->init, *this );

        MUTATE_END( Declaration, node );
}

//--------------------------------------------------------------------------
// TypedefDecl
template< typename pass_type >
void PassVisitor< pass_type >::visit( TypedefDecl * node ) {
        VISIT_START( node );

        {
                auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                maybeAccept_impl( node->parameters, *this );
                maybeAccept_impl( node->base      , *this );
        }

        indexerAddType( node );

        maybeAccept_impl( node->assertions, *this );

        VISIT_END( node );
}

template< typename pass_type >
Declaration * PassVisitor< pass_type >::mutate( TypedefDecl * node ) {
        MUTATE_START( node );

        {
                auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                maybeMutate_impl( node->parameters, *this );
                maybeMutate_impl( node->base      , *this );
        }

        indexerAddType( node );

        maybeMutate_impl( node->assertions, *this );

        MUTATE_END( Declaration, node );
}

//--------------------------------------------------------------------------
// AsmDecl
template< typename pass_type >
void PassVisitor< pass_type >::visit( AsmDecl * node ) {
        VISIT_START( node );

        maybeAccept_impl( node->stmt, *this );

        VISIT_END( node );
}

template< typename pass_type >
AsmDecl * PassVisitor< pass_type >::mutate( AsmDecl * node ) {
        MUTATE_START( node );

        maybeMutate_impl( node->stmt, *this );

        MUTATE_END( AsmDecl, node );
}

//--------------------------------------------------------------------------
// CompoundStmt
template< typename pass_type >
void PassVisitor< pass_type >::visit( CompoundStmt * node ) {
        VISIT_START( node );
        {
                auto guard1 = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                auto guard2 = makeFuncGuard( [this]() { call_beginScope();   }, [this]() { call_endScope();     } );
                visitStatementList( node->kids );
        }
        VISIT_END( node );
}

template< typename pass_type >
CompoundStmt * PassVisitor< pass_type >::mutate( CompoundStmt * node ) {
        MUTATE_START( node );
        {
                auto guard1 = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                auto guard2 = makeFuncGuard( [this]() { call_beginScope();   }, [this]() { call_endScope();     } );
                mutateStatementList( node->kids );
        }
        MUTATE_END( CompoundStmt, node );
}

//--------------------------------------------------------------------------
// ExprStmt
template< typename pass_type >
void PassVisitor< pass_type >::visit( ExprStmt * node ) {
        VISIT_START( node );

        visitExpression( node->expr );

        VISIT_END( node );
}

template< typename pass_type >
Statement * PassVisitor< pass_type >::mutate( ExprStmt * node ) {
        MUTATE_START( node );

        node->expr = mutateExpression( node->expr );

        MUTATE_END( Statement, node );
}

//--------------------------------------------------------------------------
// AsmStmt
template< typename pass_type >
void PassVisitor< pass_type >::visit( AsmStmt * node ) {
        VISIT_START( node )

        maybeAccept_impl( node->instruction, *this );
        maybeAccept_impl( node->output, *this );
        maybeAccept_impl( node->input, *this );
        maybeAccept_impl( node->clobber, *this );

        VISIT_END( node );
}

template< typename pass_type >
Statement * PassVisitor< pass_type >::mutate( AsmStmt * node ) {
        MUTATE_START( node );

        maybeMutate_impl( node->instruction, *this );
        maybeMutate_impl( node->output, *this );
        maybeMutate_impl( node->input, *this );
        maybeMutate_impl( node->clobber, *this );

        MUTATE_END( Statement, node );
}

//--------------------------------------------------------------------------
// IfStmt
template< typename pass_type >
void PassVisitor< pass_type >::visit( IfStmt * node ) {
        VISIT_START( node );
        {
                // if statements introduce a level of scope (for the initialization)
                auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                maybeAccept_impl( node->get_initialization(), *this );
                visitExpression ( node->condition );
                node->thenPart = visitStatement( node->thenPart );
                node->elsePart = visitStatement( node->elsePart );
        }
        VISIT_END( node );
}

template< typename pass_type >
Statement * PassVisitor< pass_type >::mutate( IfStmt * node ) {
        MUTATE_START( node );
        {
                // if statements introduce a level of scope (for the initialization)
                auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                maybeMutate_impl( node->get_initialization(), *this );
                node->condition = mutateExpression( node->condition );
                node->thenPart  = mutateStatement ( node->thenPart  );
                node->elsePart  = mutateStatement ( node->elsePart  );
        }
        MUTATE_END( Statement, node );
}

//--------------------------------------------------------------------------
// WhileStmt
template< typename pass_type >
void PassVisitor< pass_type >::visit( WhileStmt * node ) {
        VISIT_START( node );

        visitExpression( node->condition );
        node->body = visitStatement( node->body );

        VISIT_END( node );
}

template< typename pass_type >
Statement * PassVisitor< pass_type >::mutate( WhileStmt * node ) {
        MUTATE_START( node );

        node->condition = mutateExpression( node->condition );
        node->body      = mutateStatement ( node->body      );

        MUTATE_END( Statement, node );
}

//--------------------------------------------------------------------------
// ForStmt
template< typename pass_type >
void PassVisitor< pass_type >::visit( ForStmt * node ) {
        VISIT_START( node );
        {
                // for statements introduce a level of scope (for the initialization)
                auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                maybeAccept_impl( node->initialization, *this );
                visitExpression( node->condition );
                visitExpression( node->increment );
                node->body = visitStatement( node->body );
        }
        VISIT_END( node );
}

template< typename pass_type >
Statement * PassVisitor< pass_type >::mutate( ForStmt * node ) {
        MUTATE_START( node );
        {
                // for statements introduce a level of scope (for the initialization)
                auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                maybeMutate_impl( node->initialization, *this );
                node->condition = mutateExpression( node->condition );
                node->increment = mutateExpression( node->increment );
                node->body      = mutateStatement ( node->body      );
        }
        MUTATE_END( Statement, node );
}

//--------------------------------------------------------------------------
// SwitchStmt
template< typename pass_type >
void PassVisitor< pass_type >::visit( SwitchStmt * node ) {
        VISIT_START( node );

        visitExpression   ( node->condition  );
        visitStatementList( node->statements );

        VISIT_END( node );
}

template< typename pass_type >
Statement * PassVisitor< pass_type >::mutate( SwitchStmt * node ) {
        MUTATE_START( node );

        node->condition = mutateExpression( node->condition );
        mutateStatementList( node->statements );

        MUTATE_END( Statement, node );
}

//--------------------------------------------------------------------------
// CaseStmt
template< typename pass_type >
void PassVisitor< pass_type >::visit( CaseStmt * node ) {
        VISIT_START( node );

        visitExpression   ( node->condition );
        visitStatementList( node->stmts     );

        VISIT_END( node );
}

template< typename pass_type >
Statement * PassVisitor< pass_type >::mutate( CaseStmt * node ) {
        MUTATE_START( node );

        node->condition = mutateExpression( node->condition );
        mutateStatementList( node->stmts );

        MUTATE_END( Statement, node );
}

//--------------------------------------------------------------------------
// BranchStmt
template< typename pass_type >
void PassVisitor< pass_type >::visit( BranchStmt * node ) {
        VISIT_START( node );
        VISIT_END( node );
}

template< typename pass_type >
Statement * PassVisitor< pass_type >::mutate( BranchStmt * node ) {
        MUTATE_START( node );
        MUTATE_END( Statement, node );
}

//--------------------------------------------------------------------------
// ReturnStmt
template< typename pass_type >
void PassVisitor< pass_type >::visit( ReturnStmt * node ) {
        VISIT_START( node );

        visitExpression( node->expr );

        VISIT_END( node );
}

template< typename pass_type >
Statement * PassVisitor< pass_type >::mutate( ReturnStmt * node ) {
        MUTATE_START( node );

        node->expr = mutateExpression( node->expr );

        MUTATE_END( Statement, node );
}

//--------------------------------------------------------------------------
// ThrowStmt

template< typename pass_type >
void PassVisitor< pass_type >::visit( ThrowStmt * node ) {
        VISIT_START( node );

        maybeAccept_impl( node->expr, *this );
        maybeAccept_impl( node->target, *this );

        VISIT_END( node );
}

template< typename pass_type >
Statement * PassVisitor< pass_type >::mutate( ThrowStmt * node ) {
        MUTATE_START( node );

        maybeMutate_impl( node->expr, *this );
        maybeMutate_impl( node->target, *this );

        MUTATE_END( Statement, node );
}

//--------------------------------------------------------------------------
// TryStmt
template< typename pass_type >
void PassVisitor< pass_type >::visit( TryStmt * node ) {
        VISIT_START( node );

        maybeAccept_impl( node->block       , *this );
        maybeAccept_impl( node->handlers    , *this );
        maybeAccept_impl( node->finallyBlock, *this );

        VISIT_END( node );
}

template< typename pass_type >
Statement * PassVisitor< pass_type >::mutate( TryStmt * node ) {
        MUTATE_START( node );

        maybeMutate_impl( node->block       , *this );
        maybeMutate_impl( node->handlers    , *this );
        maybeMutate_impl( node->finallyBlock, *this );

        MUTATE_END( Statement, node );
}

//--------------------------------------------------------------------------
// CatchStmt
template< typename pass_type >
void PassVisitor< pass_type >::visit( CatchStmt * node ) {
        VISIT_START( node );
        {
                // catch statements introduce a level of scope (for the caught exception)
                auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                maybeAccept_impl( node->decl, *this );
                node->cond = visitExpression( node->cond );
                node->body = visitStatement ( node->body );
        }
        VISIT_END( node );
}

template< typename pass_type >
Statement * PassVisitor< pass_type >::mutate( CatchStmt * node ) {
        MUTATE_START( node );
        {
                // catch statements introduce a level of scope (for the caught exception)
                auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                maybeMutate_impl( node->decl, *this );
                node->cond = mutateExpression( node->cond );
                node->body = mutateStatement ( node->body );
        }
        MUTATE_END( Statement, node );
}

//--------------------------------------------------------------------------
// FinallyStmt
template< typename pass_type >
void PassVisitor< pass_type >::visit( FinallyStmt * node ) {
        VISIT_START( node );

        maybeAccept_impl( node->block, *this );

        VISIT_END( node );
}

template< typename pass_type >
Statement * PassVisitor< pass_type >::mutate( FinallyStmt * node ) {
        MUTATE_START( node );

        maybeMutate_impl( node->block, *this );

        MUTATE_END( Statement, node );
}

//--------------------------------------------------------------------------
// WaitForStmt
template< typename pass_type >
void PassVisitor< pass_type >::visit( WaitForStmt * node ) {
        VISIT_BODY( node );
}

template< typename pass_type >
Statement * PassVisitor< pass_type >::mutate( WaitForStmt * node ) {
        MUTATE_BODY( Statement, node );
}



//--------------------------------------------------------------------------
// NullStmt
template< typename pass_type >
void PassVisitor< pass_type >::visit( WithStmt * node ) {
        VISIT_START( node );
        maybeAccept_impl( node->exprs, *this );
        {
                // catch statements introduce a level of scope (for the caught exception)
                auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                indexerAddWith( node->exprs );
                maybeAccept_impl( node->stmt, *this );
        }
        VISIT_END( node );
}

template< typename pass_type >
Statement * PassVisitor< pass_type >::mutate( WithStmt * node ) {
        MUTATE_START( node );
        maybeMutate_impl( node->exprs, *this );
        {
                // catch statements introduce a level of scope (for the caught exception)
                auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                indexerAddWith( node->exprs );
                maybeMutate_impl( node->stmt, *this );
        }
        MUTATE_END( Statement, node );
}

//--------------------------------------------------------------------------
// NullStmt
template< typename pass_type >
void PassVisitor< pass_type >::visit( NullStmt * node ) {
        VISIT_BODY( node );
}

template< typename pass_type >
NullStmt * PassVisitor< pass_type >::mutate( NullStmt * node ) {
        MUTATE_BODY( NullStmt, node );
}

//--------------------------------------------------------------------------
// DeclStmt
template< typename pass_type >
void PassVisitor< pass_type >::visit( DeclStmt * node ) {
        VISIT_BODY( node );
}

template< typename pass_type >
Statement * PassVisitor< pass_type >::mutate( DeclStmt * node ) {
        MUTATE_BODY( Statement, node );
}

//--------------------------------------------------------------------------
// ImplicitCtorDtorStmt
template< typename pass_type >
void PassVisitor< pass_type >::visit( ImplicitCtorDtorStmt * node ) {
        VISIT_BODY( node );
}

template< typename pass_type >
Statement * PassVisitor< pass_type >::mutate( ImplicitCtorDtorStmt * node ) {
        MUTATE_BODY( Statement, node );
}

//--------------------------------------------------------------------------
// ApplicationExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( ApplicationExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result  , *this );
        maybeAccept_impl        ( node->function, *this );
        maybeAccept_impl        ( node->args    , *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( ApplicationExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env     , *this );
        indexerScopedMutate( node->result  , *this );
        maybeMutate_impl   ( node->function, *this );
        maybeMutate_impl   ( node->args    , *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// UntypedExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( UntypedExpr * node ) {
        VISIT_START( node );

        // maybeAccept_impl( node->get_env(), *this );
        indexerScopedAccept( node->result, *this );

        for ( auto expr : node->args ) {
                visitExpression( expr );
        }

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( UntypedExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env   , *this );
        indexerScopedMutate( node->result, *this );

        for ( auto& expr : node->args ) {
                expr = mutateExpression( expr );
        }

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// NameExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( NameExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result, *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( NameExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env   , *this );
        indexerScopedMutate( node->result, *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// CastExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( CastExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result, *this );
        maybeAccept_impl        ( node->arg   , *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( CastExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env   , *this );
        indexerScopedMutate( node->result, *this );
        maybeMutate_impl   ( node->arg   , *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// VirtualCastExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( VirtualCastExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result, *this );
        maybeAccept_impl( node->arg, *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( VirtualCastExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env   , *this );
        indexerScopedMutate( node->result, *this );
        maybeMutate_impl   ( node->arg   , *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// AddressExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( AddressExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result, *this );
        maybeAccept_impl   ( node->arg   , *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( AddressExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env   , *this );
        indexerScopedMutate( node->result, *this );
        maybeMutate_impl   ( node->arg   , *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// LabelAddressExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( LabelAddressExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result, *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( LabelAddressExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env   , *this );
        indexerScopedMutate( node->result, *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// UntypedMemberExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( UntypedMemberExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result   , *this );
        maybeAccept_impl   ( node->aggregate, *this );
        maybeAccept_impl   ( node->member   , *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( UntypedMemberExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env      , *this );
        indexerScopedMutate( node->result   , *this );
        maybeMutate_impl   ( node->aggregate, *this );
        maybeMutate_impl   ( node->member   , *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// MemberExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( MemberExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result   , *this );
        maybeAccept_impl   ( node->aggregate, *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( MemberExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env      , *this );
        indexerScopedMutate( node->result   , *this );
        maybeMutate_impl   ( node->aggregate, *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// VariableExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( VariableExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result, *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( VariableExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env   , *this );
        indexerScopedMutate( node->result, *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// ConstantExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( ConstantExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result   , *this );
        maybeAccept_impl   ( &node->constant, *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( ConstantExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env   , *this );
        indexerScopedMutate( node->result, *this );
        Constant * ptr = &node->constant;
        maybeMutate_impl( ptr, *this );
        node->constant = *ptr;

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// SizeofExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( SizeofExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result, *this );
        if ( node->get_isType() ) {
                maybeAccept_impl( node->type, *this );
        } else {
                maybeAccept_impl( node->expr, *this );
        }

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( SizeofExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env   , *this );
        indexerScopedMutate( node->result, *this );
        if ( node->get_isType() ) {
                maybeMutate_impl( node->type, *this );
        } else {
                maybeMutate_impl( node->expr, *this );
        }

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// AlignofExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( AlignofExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result, *this );
        if ( node->get_isType() ) {
                maybeAccept_impl( node->type, *this );
        } else {
                maybeAccept_impl( node->expr, *this );
        }

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( AlignofExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env   , *this );
        indexerScopedMutate( node->result, *this );
        if ( node->get_isType() ) {
                maybeMutate_impl( node->type, *this );
        } else {
                maybeMutate_impl( node->expr, *this );
        }

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// UntypedOffsetofExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( UntypedOffsetofExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result, *this );
        maybeAccept_impl   ( node->type  , *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( UntypedOffsetofExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env   , *this );
        indexerScopedMutate( node->result, *this );
        maybeMutate_impl   ( node->type  , *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// OffsetofExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( OffsetofExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result, *this );
        maybeAccept_impl   ( node->type  , *this );
        maybeAccept_impl   ( node->member, *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( OffsetofExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env   , *this );
        indexerScopedMutate( node->result, *this );
        maybeMutate_impl   ( node->type  , *this );
        maybeMutate_impl   ( node->member, *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// OffsetPackExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( OffsetPackExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result, *this );
        maybeAccept_impl   ( node->type  , *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( OffsetPackExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env   , *this );
        indexerScopedMutate( node->result, *this );
        maybeMutate_impl   ( node->type  , *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// AttrExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( AttrExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result, *this );
        if ( node->get_isType() ) {
                maybeAccept_impl( node->type, *this );
        } else {
                maybeAccept_impl( node->expr, *this );
        }

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( AttrExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env   , *this );
        indexerScopedMutate( node->result, *this );
        if ( node->get_isType() ) {
                maybeMutate_impl( node->type, *this );
        } else {
                maybeMutate_impl( node->expr, *this );
        }

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// LogicalExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( LogicalExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result, *this );
        maybeAccept_impl   ( node->arg1  , *this );
        maybeAccept_impl   ( node->arg2  , *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( LogicalExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env   , *this );
        indexerScopedMutate( node->result, *this );
        maybeMutate_impl   ( node->arg1  , *this );
        maybeMutate_impl   ( node->arg2  , *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// ConditionalExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( ConditionalExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result, *this );
        maybeAccept_impl        ( node->arg1  , *this );
        maybeAccept_impl        ( node->arg2  , *this );
        maybeAccept_impl        ( node->arg3  , *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( ConditionalExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env   , *this );
        indexerScopedMutate( node->result, *this );
        maybeMutate_impl   ( node->arg1  , *this );
        maybeMutate_impl   ( node->arg2  , *this );
        maybeMutate_impl   ( node->arg3  , *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// CommaExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( CommaExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result, *this );
        maybeAccept_impl   ( node->arg1  , *this );
        maybeAccept_impl   ( node->arg2  , *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( CommaExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env   , *this );
        indexerScopedMutate( node->result, *this );
        maybeMutate_impl   ( node->arg1  , *this );
        maybeMutate_impl   ( node->arg2  , *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// TypeExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( TypeExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result, *this );
        maybeAccept_impl   ( node->type, *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( TypeExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env   , *this );
        indexerScopedMutate( node->result, *this );
        maybeMutate_impl   ( node->type  , *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// AsmExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( AsmExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result    , *this );
        maybeAccept_impl   ( node->inout     , *this );
        maybeAccept_impl   ( node->constraint, *this );
        maybeAccept_impl   ( node->operand   , *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( AsmExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env       , *this );
        indexerScopedMutate( node->result    , *this );
        maybeMutate_impl   ( node->inout     , *this );
        maybeMutate_impl   ( node->constraint, *this );
        maybeMutate_impl   ( node->operand   , *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// ImplicitCopyCtorExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( ImplicitCopyCtorExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result     , *this );
        maybeAccept_impl   ( node->callExpr   , *this );
        maybeAccept_impl   ( node->tempDecls  , *this );
        maybeAccept_impl   ( node->returnDecls, *this );
        maybeAccept_impl   ( node->dtors      , *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( ImplicitCopyCtorExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env        , *this );
        indexerScopedMutate( node->result     , *this );
        maybeMutate_impl   ( node->callExpr   , *this );
        maybeMutate_impl   ( node->tempDecls  , *this );
        maybeMutate_impl   ( node->returnDecls, *this );
        maybeMutate_impl   ( node->dtors      , *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// ConstructorExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( ConstructorExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result  , *this );
        maybeAccept_impl   ( node->callExpr, *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( ConstructorExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env     , *this );
        indexerScopedMutate( node->result  , *this );
        maybeMutate_impl   ( node->callExpr, *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// CompoundLiteralExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( CompoundLiteralExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result     , *this );
        maybeAccept_impl   ( node->initializer, *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( CompoundLiteralExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env        , *this );
        indexerScopedMutate( node->result     , *this );
        maybeMutate_impl     ( node->initializer, *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// RangeExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( RangeExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result, *this );
        maybeAccept_impl   ( node->low   , *this );
        maybeAccept_impl   ( node->high  , *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( RangeExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env   , *this );
        indexerScopedMutate( node->result, *this );
        maybeMutate_impl   ( node->low   , *this );
        maybeMutate_impl   ( node->high  , *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// UntypedTupleExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( UntypedTupleExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result, *this );
        maybeAccept_impl   ( node->exprs , *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( UntypedTupleExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env   , *this );
        indexerScopedMutate( node->result, *this );
        maybeMutate_impl   ( node->exprs , *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// TupleExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( TupleExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result, *this );
        maybeAccept_impl   ( node->exprs , *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( TupleExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env   , *this );
        indexerScopedMutate( node->result, *this );
        maybeMutate_impl   ( node->exprs , *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// TupleIndexExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( TupleIndexExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result, *this );
        maybeAccept_impl   ( node->tuple , *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( TupleIndexExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env   , *this );
        indexerScopedMutate( node->result, *this );
        maybeMutate_impl   ( node->tuple , *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// TupleAssignExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( TupleAssignExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result  , *this );
        maybeAccept_impl   ( node->stmtExpr, *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( TupleAssignExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env     , *this );
        indexerScopedMutate( node->result  , *this );
        maybeMutate_impl   ( node->stmtExpr, *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// StmtExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( StmtExpr * node ) {
        VISIT_START( node );

        // don't want statements from outer CompoundStmts to be added to this StmtExpr
        ValueGuardPtr< TypeSubstitution * >      oldEnv        ( get_env_ptr() );
        ValueGuardPtr< std::list< Statement* > > oldBeforeStmts( get_beforeStmts() );
        ValueGuardPtr< std::list< Statement* > > oldAfterStmts ( get_afterStmts () );

        indexerScopedAccept( node->result     , *this );
        maybeAccept_impl   ( node->statements , *this );
        maybeAccept_impl   ( node->returnDecls, *this );
        maybeAccept_impl   ( node->dtors      , *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( StmtExpr * node ) {
        MUTATE_START( node );

        // don't want statements from outer CompoundStmts to be added to this StmtExpr
        ValueGuardPtr< TypeSubstitution * >      oldEnv        ( get_env_ptr() );
        ValueGuardPtr< std::list< Statement* > > oldBeforeStmts( get_beforeStmts() );
        ValueGuardPtr< std::list< Statement* > > oldAfterStmts ( get_afterStmts () );

        indexerScopedMutate( node->result     , *this );
        maybeMutate_impl   ( node->statements , *this );
        maybeMutate_impl   ( node->returnDecls, *this );
        maybeMutate_impl   ( node->dtors      , *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// UniqueExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( UniqueExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result, *this );
        maybeAccept_impl   ( node->expr  , *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( UniqueExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env   , *this );
        indexerScopedMutate( node->result, *this );
        maybeMutate_impl   ( node->expr  , *this );

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// UntypedInitExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( UntypedInitExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result, *this );
        maybeAccept_impl   ( node->expr  , *this );
        // not currently visiting initAlts, but this doesn't matter since this node is only used in the resolver.

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( UntypedInitExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env   , *this );
        indexerScopedMutate( node->result, *this );
        maybeMutate_impl   ( node->expr  , *this );
        // not currently visiting initAlts, but this doesn't matter since this node is only used in the resolver.

        MUTATE_END( Expression, node );
}

//--------------------------------------------------------------------------
// InitExpr
template< typename pass_type >
void PassVisitor< pass_type >::visit( InitExpr * node ) {
        VISIT_START( node );

        indexerScopedAccept( node->result, *this );
        maybeAccept_impl   ( node->expr  , *this );
        maybeAccept_impl   ( node->designation, *this );

        VISIT_END( node );
}

template< typename pass_type >
Expression * PassVisitor< pass_type >::mutate( InitExpr * node ) {
        MUTATE_START( node );

        indexerScopedMutate( node->env   , *this );
        indexerScopedMutate( node->result, *this );
        maybeMutate_impl   ( node->expr  , *this );
        maybeMutate_impl   ( node->designation, *this );

        MUTATE_END( Expression, node );
}

template< typename pass_type >
void PassVisitor< pass_type >::visit( VoidType * node ) {
        VISIT_BODY( node );
}

template< typename pass_type >
void PassVisitor< pass_type >::visit( BasicType * node ) {
        VISIT_BODY( node );
}

template< typename pass_type >
void PassVisitor< pass_type >::visit( PointerType * node ) {
        VISIT_BODY( node );
}

template< typename pass_type >
void PassVisitor< pass_type >::visit( ArrayType * node ) {
        VISIT_BODY( node );
}

template< typename pass_type >
void PassVisitor< pass_type >::visit( ReferenceType * node ) {
        VISIT_BODY( node );
}

template< typename pass_type >
void PassVisitor< pass_type >::visit( FunctionType * node ) {
        VISIT_BODY( node );
}

//--------------------------------------------------------------------------
// StructInstType
template< typename pass_type >
void PassVisitor< pass_type >::visit( StructInstType * node ) {
        VISIT_START( node );

        indexerAddStruct( node->name );

        {
                auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                maybeAccept_impl( node->forall    , *this );
                maybeAccept_impl( node->parameters, *this );
        }

        VISIT_END( node );
}

template< typename pass_type >
Type * PassVisitor< pass_type >::mutate( StructInstType * node ) {
        MUTATE_START( node );

        indexerAddStruct( node->name );

        {
                auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                maybeMutate_impl( node->forall    , *this );
                maybeMutate_impl( node->parameters, *this );
        }

        MUTATE_END( Type, node );
}

//--------------------------------------------------------------------------
// UnionInstType
template< typename pass_type >
void PassVisitor< pass_type >::visit( UnionInstType * node ) {
        VISIT_START( node );

        indexerAddStruct( node->name );

        {
                auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                maybeAccept_impl( node->forall    , *this );
                maybeAccept_impl( node->parameters, *this );
        }

        VISIT_END( node );
}

template< typename pass_type >
Type * PassVisitor< pass_type >::mutate( UnionInstType * node ) {
        MUTATE_START( node );

        indexerAddStruct( node->name );

        {
                auto guard = makeFuncGuard( [this]() { indexerScopeEnter(); }, [this]() { indexerScopeLeave(); } );
                maybeMutate_impl( node->forall    , *this );
                maybeMutate_impl( node->parameters, *this );
        }

        MUTATE_END( Type, node );
}

//--------------------------------------------------------------------------
// EnumInstType
template< typename pass_type >
void PassVisitor< pass_type >::visit( EnumInstType * node ) {
        VISIT_BODY( node );
}

template< typename pass_type >
Type * PassVisitor< pass_type >::mutate( EnumInstType * node ) {
        MUTATE_BODY( Type, node );
}

//--------------------------------------------------------------------------
// TraitInstType
template< typename pass_type >
void PassVisitor< pass_type >::visit( TraitInstType * node ) {
        VISIT_START( node );

        maybeAccept_impl( node->forall    , *this );
        maybeAccept_impl( node->parameters, *this );

        VISIT_END( node );
}

template< typename pass_type >
Type * PassVisitor< pass_type >::mutate( TraitInstType * node ) {
        MUTATE_START( node );

        maybeMutate_impl( node->forall    , *this );
        maybeMutate_impl( node->parameters, *this );

        MUTATE_END( Type, node );
}

//--------------------------------------------------------------------------
// TypeInstType
template< typename pass_type >
void PassVisitor< pass_type >::visit( TypeInstType * node ) {
        VISIT_BODY( node );
}

template< typename pass_type >
void PassVisitor< pass_type >::visit( TupleType * node ) {
        VISIT_BODY( node );
}

template< typename pass_type >
void PassVisitor< pass_type >::visit( TypeofType * node ) {
        VISIT_BODY( node );
}

template< typename pass_type >
void PassVisitor< pass_type >::visit( AttrType * node ) {
        VISIT_BODY( node );
}

template< typename pass_type >
void PassVisitor< pass_type >::visit( VarArgsType * node ) {
        VISIT_BODY( node );
}

template< typename pass_type >
void PassVisitor< pass_type >::visit( ZeroType * node ) {
        VISIT_BODY( node );
}

template< typename pass_type >
void PassVisitor< pass_type >::visit( OneType * node ) {
        VISIT_BODY( node );
}

template< typename pass_type >
void PassVisitor< pass_type >::visit( Designation * node ) {
        VISIT_START( node );

        maybeAccept_impl( node->get_designators(), *this );

        VISIT_END( node );
}

template< typename pass_type >
Designation * PassVisitor< pass_type >::mutate( Designation * node ) {
        MUTATE_START( node );

        maybeMutate_impl( node->get_designators(), *this );

        MUTATE_END( Designation, node );
}

//--------------------------------------------------------------------------
// SingleInit
template< typename pass_type >
void PassVisitor< pass_type >::visit( SingleInit * node ) {
        VISIT_START( node );

        visitExpression( node->get_value() );

        VISIT_END( node );
}

template< typename pass_type >
Initializer * PassVisitor< pass_type >::mutate( SingleInit * node ) {
        MUTATE_START( node );

        node->set_value( mutateExpression( node->get_value() ) );

        MUTATE_END( Initializer, node );
}

template< typename pass_type >
void PassVisitor< pass_type >::visit( ListInit * node ) {
        VISIT_BODY( node );
}

template< typename pass_type >
void PassVisitor< pass_type >::visit( ConstructorInit * node ) {
        VISIT_BODY( node );
}

template< typename pass_type >
void PassVisitor< pass_type >::visit( Subrange * node ) {
        VISIT_BODY( node );
}

template< typename pass_type >
void PassVisitor< pass_type >::visit( Constant * node ) {
        VISIT_BODY( node );
}

template< typename pass_type >
void PassVisitor< pass_type >::visit( Attribute * node ) {
        VISIT_BODY( node );
}

//---------------------------------------------------------------------------------------------------------------
template< typename pass_type >
Type * PassVisitor< pass_type >::mutate( VoidType * node ) {
        MUTATE_BODY( Type, node );
}

template< typename pass_type >
Type * PassVisitor< pass_type >::mutate( BasicType * node ) {
        MUTATE_BODY( Type, node );
}

template< typename pass_type >
Type * PassVisitor< pass_type >::mutate( PointerType * node ) {
        MUTATE_BODY( Type, node );
}

template< typename pass_type >
Type * PassVisitor< pass_type >::mutate( ArrayType * node ) {
        MUTATE_BODY( Type, node );
}

template< typename pass_type >
Type * PassVisitor< pass_type >::mutate( ReferenceType * node ) {
        MUTATE_BODY( Type, node );
}

template< typename pass_type >
Type * PassVisitor< pass_type >::mutate( FunctionType * node ) {
        MUTATE_BODY( Type, node );
}

template< typename pass_type >
Type * PassVisitor< pass_type >::mutate( TypeInstType * node ) {
        MUTATE_BODY( Type, node );
}

template< typename pass_type >
Type * PassVisitor< pass_type >::mutate( TupleType * node ) {
        MUTATE_BODY( Type, node );
}

template< typename pass_type >
Type * PassVisitor< pass_type >::mutate( TypeofType * node ) {
        MUTATE_BODY( Type, node );
}

template< typename pass_type >
Type * PassVisitor< pass_type >::mutate( AttrType * node ) {
        MUTATE_BODY( Type, node );
}

template< typename pass_type >
Type * PassVisitor< pass_type >::mutate( VarArgsType * node ) {
        MUTATE_BODY( Type, node );
}

template< typename pass_type >
Type * PassVisitor< pass_type >::mutate( ZeroType * node ) {
        MUTATE_BODY( Type, node );
}

template< typename pass_type >
Type * PassVisitor< pass_type >::mutate( OneType * node ) {
        MUTATE_BODY( Type, node );
}

template< typename pass_type >
Initializer * PassVisitor< pass_type >::mutate( ListInit * node ) {
        MUTATE_BODY( Initializer, node );
}

template< typename pass_type >
Initializer * PassVisitor< pass_type >::mutate( ConstructorInit * node ) {
        MUTATE_BODY( Initializer, node );
}

template< typename pass_type >
Subrange * PassVisitor< pass_type >::mutate( Subrange * node  )  {
        MUTATE_BODY( Subrange, node );
}

template< typename pass_type >
Constant * PassVisitor< pass_type >::mutate( Constant * node  )  {
        MUTATE_BODY( Constant, node );
}

template< typename pass_type >
Attribute * PassVisitor< pass_type >::mutate( Attribute * node  )  {
        MUTATE_BODY( Attribute, node );
}

template< typename pass_type >
TypeSubstitution * PassVisitor< pass_type >::mutate( TypeSubstitution * node ) {
        MUTATE_START( node );

        for ( auto & p : node->typeEnv ) {
                indexerScopedMutate( p.second, *this );
        }
        for ( auto & p : node->varEnv ) {
                indexerScopedMutate( p.second, *this );
        }

        MUTATE_END( TypeSubstitution, node );
}