source: src/ResolvExpr/PtrsCastable.cc @ 0873d22e

//
// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// PtrsCastable.cc --
//
// Author           : Richard C. Bilson
// Created On       : Sun May 17 11:48:00 2015
// Last Modified By : Peter A. Buhr
// Last Modified On : Wed Mar  2 17:36:18 2016
// Update Count     : 8
//

#include "Common/PassVisitor.h"
#include "ResolvExpr/TypeEnvironment.h"  // for EqvClass, TypeEnvironment
#include "SymTab/Indexer.h"              // for Indexer
#include "SynTree/Declaration.h"         // for TypeDecl, TypeDecl::Kind::Ftype
#include "SynTree/Type.h"                // for TypeInstType, Type, BasicType
#include "SynTree/Visitor.h"             // for Visitor
#include "typeops.h"                     // for ptrsAssignable

namespace ResolvExpr {
        struct PtrsCastable : public WithShortCircuiting  {
          public:
                PtrsCastable( Type *dest, const TypeEnvironment &env, const SymTab::Indexer &indexer );

                int get_result() const { return result; }

                void previsit( Type * ) { visit_children = false; }

                void postvisit( VoidType * voidType );
                void postvisit( BasicType * basicType );
                void postvisit( PointerType * pointerType );
                void postvisit( ArrayType * arrayType );
                void postvisit( FunctionType * functionType );
                void postvisit( StructInstType * inst );
                void postvisit( UnionInstType * inst );
                void postvisit( EnumInstType * inst );
                void postvisit( TraitInstType * inst );
                void postvisit( TypeInstType * inst );
                void postvisit( TupleType * tupleType );
                void postvisit( VarArgsType * varArgsType );
                void postvisit( ZeroType * zeroType );
                void postvisit( OneType * oneType );
          private:
                Type *dest;
                int result;
                const TypeEnvironment &env;
                const SymTab::Indexer &indexer;
        };

        namespace {
                int objectCast( Type *src, const TypeEnvironment &env, const SymTab::Indexer &indexer ) {
                        if ( dynamic_cast< FunctionType* >( src ) ) {
                                return -1;
                        } else if ( TypeInstType *typeInst = dynamic_cast< TypeInstType* >( src ) ) {
                                EqvClass eqvClass;
                                if ( NamedTypeDecl *ntDecl = indexer.lookupType( typeInst->get_name() ) ) {
                                        if ( TypeDecl *tyDecl = dynamic_cast< TypeDecl* >( ntDecl ) ) {
                                                if ( tyDecl->get_kind() == TypeDecl::Ftype ) {
                                                        return -1;
                                                } // if
                                        } //if
                                } else if ( env.lookup( typeInst->get_name(), eqvClass ) ) {
                                        if ( eqvClass.data.kind == TypeDecl::Ftype ) {
                                                return -1;
                                        } // if
                                } // if
                        } //if
                        return 1;
                }
                int functionCast( Type *src, const TypeEnvironment &env, const SymTab::Indexer &indexer ) {
                        return -1 * objectCast( src, env, indexer );  // reverse the sense of objectCast
                }
        }

        int ptrsCastable( Type *src, Type *dest, const TypeEnvironment &env, const SymTab::Indexer &indexer ) {
                if ( TypeInstType *destAsTypeInst = dynamic_cast< TypeInstType* >( dest ) ) {
                        EqvClass eqvClass;
                        if ( env.lookup( destAsTypeInst->get_name(), eqvClass ) ) {
                                // xxx - should this be ptrsCastable?
                                return ptrsAssignable( src, eqvClass.type, env );
                        } // if
                } // if
                if ( dynamic_cast< VoidType* >( dest ) ) {
                        return objectCast( src, env, indexer );
                } else {
                        PassVisitor<PtrsCastable> ptrs( dest, env, indexer );
                        src->accept( ptrs );
                        return ptrs.pass.get_result();
                } // if
        }

        PtrsCastable::PtrsCastable( Type *dest, const TypeEnvironment &env, const SymTab::Indexer &indexer )
                : dest( dest ), result( 0 ), env( env ), indexer( indexer )     {
        }

        void PtrsCastable::postvisit( VoidType * ) {
                result = objectCast( dest, env, indexer );
        }

        void PtrsCastable::postvisit( BasicType * ) {
                result = objectCast( dest, env, indexer );
        }

        void PtrsCastable::postvisit( PointerType * ) {
                result = objectCast( dest, env, indexer );
        }

        void PtrsCastable::postvisit( ArrayType * ) {
                result = objectCast( dest, env, indexer );
        }

        void PtrsCastable::postvisit( FunctionType * ) {
                // result = -1;
                result = functionCast( dest, env, indexer );
        }

        void PtrsCastable::postvisit( StructInstType * ) {
                result = objectCast( dest, env, indexer );
        }

        void PtrsCastable::postvisit( UnionInstType * ) {
                result = objectCast( dest, env, indexer );
        }

        void PtrsCastable::postvisit( EnumInstType * ) {
                if ( dynamic_cast< EnumInstType* >( dest ) ) {
                        result = 1;
                } else if ( BasicType *bt = dynamic_cast< BasicType* >( dest ) ) {
                        if ( bt->get_kind() == BasicType::SignedInt ) {
                                result = 0;
                        } else {
                                result = 1;
                        }
                } else {
                        result = objectCast( dest, env, indexer );
                }
        }

        void PtrsCastable::postvisit( TraitInstType * ) {}

        void PtrsCastable::postvisit(TypeInstType *inst) {
                //result = objectCast( inst, env, indexer ) > 0 && objectCast( dest, env, indexer ) > 0 ? 1 : -1;
                result = objectCast( inst, env, indexer ) == objectCast( dest, env, indexer ) ? 1 : -1;
        }

        void PtrsCastable::postvisit( TupleType * ) {
                result = objectCast( dest, env, indexer );
        }

        void PtrsCastable::postvisit( VarArgsType * ) {
                result = objectCast( dest, env, indexer );
        }

        void PtrsCastable::postvisit( ZeroType * ) {
                result = objectCast( dest, env, indexer );
        }

        void PtrsCastable::postvisit( OneType * ) {
                result = objectCast( dest, env, indexer );
        }
} // namespace ResolvExpr

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// mode: c++ //
// compile-command: "make install" //
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