source: src/SymTab/TypeEquality.cc @ 711eee5

//
// 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.
//
// TypeEquality.cc -- 
//
// Author           : Rob Schluntz
// Created On       : Tue Jul 07 16:28:29 2015
// Last Modified By : Rob Schluntz
// Last Modified On : Mon Jul 20 14:16:11 2015
// Update Count     : 37
//

#include <list>
#include <iterator>
#include "Validate.h"
#include "SynTree/Visitor.h"
#include "SynTree/Type.h"
#include "SynTree/Statement.h"
#include "SynTree/TypeSubstitution.h"
#include "Indexer.h"
#include "TypeEquality.h"

namespace SymTab {
        class TypeEquality : public Visitor {
  public:
                TypeEquality( Type * other, bool vlaErr ) : result( true ), other( other ), 
                        vlaErr( vlaErr ) {}
                bool result;

  private:
                virtual void visit( FunctionType *funcType );
                virtual void visit( VoidType *voidType );
                virtual void visit( BasicType *basicType );
                virtual void visit( PointerType *pointerType );
                virtual void visit( ArrayType *arrayType );
                virtual void visit( StructInstType *structInst );
                virtual void visit( UnionInstType *unionInst );
                virtual void visit( EnumInstType *enumInst );
                virtual void visit( TypeInstType *typeInst );
                virtual void visit( VarArgsType *varArgsType );

                void handleQualifiers( Type * t );

                Type * other;
                bool vlaErr;
        };

        bool typeEquals( Type * t1, Type * t2, bool vlaErr ) {
                TypeEquality teq( t2, vlaErr );
                t1->accept( teq );
                return teq.result;
        }

        void TypeEquality::handleQualifiers( Type * t ) {
                result = result && t->get_qualifiers() == other->get_qualifiers();
        }

        void TypeEquality::visit( VoidType *voidType ) {
                handleQualifiers( voidType );
                if ( ! dynamic_cast< VoidType * >( other ) ) {
                        result = false;
                }
        }

        void TypeEquality::visit( BasicType *basicType ) {
                handleQualifiers( basicType );
                if ( BasicType * bt = dynamic_cast< BasicType * >( other ) ) {
                        result = result && basicType->get_kind() == bt->get_kind(); 
                } else {
                        result = false;
                }
        }

        void TypeEquality::visit( PointerType *pointerType ) {
                handleQualifiers( pointerType );
                if ( PointerType * pt = dynamic_cast< PointerType * >( other ) ) {
                        other = pt->get_base();
                        pointerType->get_base()->accept( *this );
                } else {
                        result = false;
                }
        }

        void TypeEquality::visit( ArrayType *arrayType ) {
                handleQualifiers( arrayType );

                if ( ArrayType * at = dynamic_cast< ArrayType * >( other ) ) {
                        // to be equal, array types must both be VLA or both not VLA
                        // and must both have a dimension expression or not have a dimension
                        result = result && arrayType->get_isVarLen() == at->get_isVarLen()
                                && ((arrayType->get_dimension() != 0 && at->get_dimension() != 0)
                                        || (arrayType->get_dimension() == 0 && at->get_dimension() == 0));

                        if ( vlaErr ) {
                                // useful for comparing typedef types - in this case, we 
                                // want types to appear distinct if either is a VLA type
                                if ( arrayType->get_isVarLen() || at->get_isVarLen() ) {
                                        result = false;
                                }
                        }

                        if ( ! arrayType->get_isVarLen() && ! at->get_isVarLen() &&
                                arrayType->get_dimension() != 0 && at->get_dimension() != 0 ) {
                                ConstantExpr * ce1 = dynamic_cast< ConstantExpr * >( arrayType->get_dimension() );
                                ConstantExpr * ce2 = dynamic_cast< ConstantExpr * >( at->get_dimension() );
                                assert(ce1 && ce2);

                                Constant * c1 = ce1->get_constant();
                                Constant * c2 = ce2->get_constant();

                                result = result && c1->get_value() == c2->get_value();
                        }

                        other = at->get_base();
                        arrayType->get_base()->accept( *this );
                } else {
                        result = false;
                }
        }

        void TypeEquality::visit( FunctionType *funcType ) {
                handleQualifiers( funcType );

                if ( FunctionType * ft = dynamic_cast< FunctionType * >( other ) ) {
                        // function types must have the same number of return types
                        // and parameters to be equivalent
                        result = result && funcType->get_returnVals().size() == ft->get_returnVals().size()
                                && funcType->get_parameters().size() == ft->get_parameters().size()
                                && funcType->get_isVarArgs() == ft->get_isVarArgs();

                        std::list< DeclarationWithType * >::iterator it1, it2;

                        // return types must be equivalent
                        it1 = funcType->get_returnVals().begin();
                        it2 = ft->get_returnVals().begin();
                        for ( ; it1 != funcType->get_returnVals().end(); ++it1, ++it2 ) {
                                if ( ! result ) return;
                                other = (*it2)->get_type();
                                (*it1)->get_type()->accept( *this );
                        }

                        // parameter types must be equivalent
                        it1 = funcType->get_parameters().begin(); 
                        it2 = ft->get_parameters().begin();
                        for ( ; it1 != funcType->get_parameters().end(); ++it1, ++it2 ) {
                                if ( ! result ) return;
                                other = (*it2)->get_type();
                                (*it1)->get_type()->accept( *this );
                        }
                } else {
                        result = false;
                }
        }

        // aggregate types only need to have the same name
        void TypeEquality::visit( StructInstType *structInst )  {
                handleQualifiers( structInst );
                if ( StructInstType * st = dynamic_cast< StructInstType * >( other ) ) {
                        result = result && structInst->get_name() == st->get_name();
                } else {
                        result = false;
                }
        }

        void TypeEquality::visit( UnionInstType *unionInst ) {
                handleQualifiers( unionInst );
                if ( UnionInstType * ut = dynamic_cast< UnionInstType * >( other ) ) {
                        result = result && unionInst->get_name() == ut->get_name();
                } else {
                        result = false;
                }
        }

        void TypeEquality::visit( EnumInstType *enumInst ) {
                handleQualifiers( enumInst );
                if ( EnumInstType * et = dynamic_cast< EnumInstType * >( other ) ) {
                        result = result && enumInst->get_name() == et->get_name();
                } else {
                        result = false;
                }
        }

        void TypeEquality::visit( TypeInstType *typeInst ) {
                handleQualifiers( typeInst );
                if ( TypeInstType * tt = dynamic_cast< TypeInstType * >( other ) ) {
                        result = result && typeInst->get_name() == tt->get_name();
                } else {
                        result = false;
                }
        }

        void TypeEquality::visit( VarArgsType *varArgsType ) {
                handleQualifiers( varArgsType );
                if ( ! dynamic_cast< VarArgsType * >( other ) ) {
                        result = false;
                }
        }
} // namespace SymTab