//
// 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 "typeops.h"
#include "SynTree/Type.h"
#include "SynTree/Declaration.h"
#include "SynTree/Visitor.h"
#include "SymTab/Indexer.h"


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

		int get_result() const { return result; }

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

	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 ) ) {
				return ptrsAssignable( src, eqvClass.type, env );
			} // if
		} // if
		if ( dynamic_cast< VoidType* >( dest ) ) {
			return objectCast( src, env, indexer );
		} else {
			PtrsCastable ptrs( dest, env, indexer );
			src->accept( ptrs );
			return ptrs.get_result();
		} // if
	}

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

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

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

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

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

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

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

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

	void PtrsCastable::visit(EnumInstType *inst) {
		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::visit(TraitInstType *inst) {
		// I definitely don't think we should be doing anything here
	}

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

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

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

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

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