source: src/ResolvExpr/PtrsCastable.cpp @ 748877f

//
// 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.cpp --
//
// Author           : Richard C. Bilson
// Created On       : Sun May 17 11:48:00 2015
// Last Modified By : Peter A. Buhr
// Last Modified On : Wed Dec 11 21:48:33 2019
// Update Count     : 9
//

#include "PtrsCastable.hpp"

#include "AST/Decl.hpp"
#include "AST/Pass.hpp"
#include "AST/Type.hpp"
#include "AST/TypeEnvironment.hpp"
#include "ResolvExpr/PtrsAssignable.hpp" // for ptrsAssignable

namespace ResolvExpr {

namespace {
        // can this type be cast to an object (1 for yes, -1 for no)
        int objectCast(
                const ast::Type * src, const ast::TypeEnvironment & env, const ast::SymbolTable & symtab
        ) {
                if ( dynamic_cast< const ast::FunctionType * >( src ) ) {
                        return -1;
                } else if ( auto inst = dynamic_cast< const ast::TypeInstType * >( src ) ) {
                        if ( const ast::NamedTypeDecl * named = symtab.lookupType( inst->name ) ) {
                                if ( auto tyDecl = dynamic_cast< const ast::TypeDecl * >( named ) ) {
                                        if ( tyDecl->kind == ast::TypeDecl::Ftype ) {
                                                return -1;
                                        }
                                }
                        } else if ( const ast::EqvClass * eqvClass = env.lookup( *inst ) ) {
                                if ( eqvClass->data.kind == ast::TypeDecl::Ftype ) {
                                        return -1;
                                }
                        }
                }

                return 1;
        }

        // can this type be cast to a function (inverse of objectCast)
        int functionCast(
                const ast::Type * src, const ast::TypeEnvironment & env, const ast::SymbolTable & symtab
        ) {
                return -1 * objectCast( src, env, symtab );
        }

        class PtrsCastable : public ast::WithShortCircuiting {
                const ast::Type * dst;
                const ast::TypeEnvironment & env;
                const ast::SymbolTable & symtab;
        public:
                int result;

                PtrsCastable(
                        const ast::Type * d, const ast::TypeEnvironment & e, const ast::SymbolTable & syms )
                : dst( d ), env( e ), symtab( syms ), result( 0 ) {}

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

                void postvisit( const ast::VoidType * ) {
                        result = objectCast( dst, env, symtab );
                }

                void postvisit( const ast::BasicType * ) {
                        result = objectCast( dst, env, symtab );
                }

                void postvisit( const ast::PointerType * ) {
                        result = objectCast( dst, env, symtab );
                }

                void postvisit( const ast::ArrayType * ) {
                        result = objectCast( dst, env, symtab );
                }

                void postvisit( const ast::FunctionType * ) {
                        result = functionCast( dst, env, symtab );
                }

                void postvisit( const ast::StructInstType * ) {
                        result = objectCast( dst, env, symtab );
                }

                void postvisit( const ast::UnionInstType * ) {
                        result = objectCast( dst, env, symtab );
                }

                void postvisit( const ast::EnumInstType * ) {
                        if ( dynamic_cast< const ast::EnumInstType * >( dst ) ) {
                                result = 1;
                        } else if ( auto bt = dynamic_cast< const ast::BasicType * >( dst ) ) {
                                if ( bt->kind == ast::BasicKind::SignedInt ) {
                                        result = 0;
                                } else {
                                        result = 1;
                                }
                        } else {
                                result = objectCast( dst, env, symtab );
                        }
                }

                void postvisit( const ast::TraitInstType * ) {}

                void postvisit( const ast::TypeInstType * inst ) {
                        // check trait and destination type are both object or both function
                        result = objectCast( inst, env, symtab ) == objectCast( dst, env, symtab ) ? 1 : -1;
                }

                void postvisit( const ast::TupleType * ) {
                        result = objectCast( dst, env, symtab );
                }

                void postvisit( const ast::VarArgsType * ) {
                        result = objectCast( dst, env, symtab );
                }

                void postvisit( const ast::ZeroType * ) {
                        result = objectCast( dst, env, symtab );
                }

                void postvisit( const ast::OneType * ) {
                        result = objectCast( dst, env, symtab );
                }

        };
} // anonymous namespace

int ptrsCastable(
        const ast::Type * src, const ast::Type * dst, const ast::SymbolTable & symtab,
        const ast::TypeEnvironment & env
) {
        if ( auto inst = dynamic_cast< const ast::TypeInstType * >( dst ) ) {
                if ( const ast::EqvClass * eqvClass = env.lookup( *inst ) ) {
                        return ptrsAssignable( src, eqvClass->bound, env );
                }
        }

        if ( dynamic_cast< const ast::VoidType * >( dst ) ) {
                return objectCast( src, env, symtab );
        } else {
                return ast::Pass<PtrsCastable>::read( src, dst, env, symtab );
        }
}

} // namespace ResolvExpr

// Local Variables: //
// tab-width: 4 //
// mode: c++ //
// compile-command: "make install" //
// End: //