source: src/ResolvExpr/PtrsCastable.cc @ 680ae0e

//
// 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 Dec 11 21:48:33 2019
// Update Count     : 9
//

#include "AST/Decl.hpp"
#include "AST/Pass.hpp"
#include "AST/Type.hpp"
#include "AST/TypeEnvironment.hpp"
#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_old : public WithShortCircuiting  {
          public:
                PtrsCastable_old( const Type * dest, const TypeEnvironment &env, const SymTab::Indexer &indexer );

                int get_result() const { return result; }

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        void PtrsCastable_old::postvisit( const OneType * ) {
                result = objectCast( dest, env, indexer );
        }

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->name ) ) {
                                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_new : public ast::WithShortCircuiting {
                const ast::Type * dst;
                const ast::TypeEnvironment & env;
                const ast::SymbolTable & symtab;
        public:
                int result;

                PtrsCastable_new(
                        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::BasicType::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->name ) ) {
                        return ptrsAssignable( src, eqvClass->bound, env );
                }
        }

        if ( dynamic_cast< const ast::VoidType * >( dst ) ) {
                return objectCast( src, env, symtab );
        } else {
                ast::Pass< PtrsCastable_new > ptrs{ dst, env, symtab };
                src->accept( ptrs );
                return ptrs.pass.result;
        }
}

} // namespace ResolvExpr

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