/*
 * This file is part of the Cforall project
 *
 * $Id: PtrsAssignable.cc,v 1.3 2005/08/29 20:14:16 rcbilson Exp $
 *
 */

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


namespace ResolvExpr {

class PtrsAssignable : public Visitor
{
public:
  PtrsAssignable( Type *dest, const TypeEnvironment &env );
  
  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(ContextInstType *inst);
  virtual void visit(TypeInstType *inst);
  virtual void visit(TupleType *tupleType);

private:
  Type *dest;
  int result;
  const TypeEnvironment &env;
};

int
ptrsAssignable( Type *src, Type *dest, const TypeEnvironment &env )
{
  if( TypeInstType *destAsTypeInst = dynamic_cast< TypeInstType* >( dest ) ) {
    EqvClass eqvClass;
    if( env.lookup( destAsTypeInst->get_name(), eqvClass ) ) {
      return ptrsAssignable( src, eqvClass.type, env );
    }
  }
  if( dynamic_cast< VoidType* >( dest ) ) {
    return 1;
  } else {
    PtrsAssignable ptrs( dest, env );
    src->accept( ptrs );
    return ptrs.get_result();
  }
}

PtrsAssignable::PtrsAssignable( Type *dest, const TypeEnvironment &env )
  : dest( dest ), result( 0 ), env( env )
{
}

void 
PtrsAssignable::visit(VoidType *voidType)
{
  if( dynamic_cast< FunctionType* >( dest ) ) {
    result = 0;
  } else {
    result = -1;
  }
}

void 
PtrsAssignable::visit(BasicType *basicType)
{
}

void 
PtrsAssignable::visit(PointerType *pointerType)
{
}

void 
PtrsAssignable::visit(ArrayType *arrayType)
{
}

void 
PtrsAssignable::visit(FunctionType *functionType)
{
  result = -1;
}

void 
PtrsAssignable::visit(StructInstType *inst)
{
  // I don't think we should be doing anything here, but I'm willing to admit that I might be wrong
}

void 
PtrsAssignable::visit(UnionInstType *inst)
{
  // I don't think we should be doing anything here, but I'm willing to admit that I might be wrong
}

void 
PtrsAssignable::visit(EnumInstType *inst)
{
  if( dynamic_cast< EnumInstType* >( inst ) ) {
    result = 1;
  } else if( BasicType *bt = dynamic_cast< BasicType* >( inst ) ) {
    result = bt->get_kind() == BasicType::SignedInt;
  }
}

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

void 
PtrsAssignable::visit(TypeInstType *inst)
{
  EqvClass eqvClass;
  if( env.lookup( inst->get_name(), eqvClass ) ) {
    result = ptrsAssignable( eqvClass.type, dest, env );
  } else {
    result = 0;
  }
}

void 
PtrsAssignable::visit(TupleType *tupleType)
{
///  // This code doesn't belong here, but it might be useful somewhere else
///   if( TupleType *destAsTuple = dynamic_cast< TupleType* >( dest ) ) {
///     int ret = 0;
///     std::list< Type* >::const_iterator srcIt = tupleType->get_types().begin();
///     std::list< Type* >::const_iterator destIt = destAsTuple->get_types().begin();
///     while( srcIt != tupleType->get_types().end() && destIt != destAsTuple->get_types().end() ) {
///       int assignResult = ptrsAssignable( *srcIt++, *destIt++ );
///       if( assignResult == 0 ) {
///         result = assignResult;
///         return;
///       } else if ( assignResult < 0 ) {
///         ret = -1;
///       } else if ( ret > 0 ) {
///         ret += assignResult;
///       }
///     }
///     if( srcIt == tupleType->get_types().end() && destIt == destAsTuple->get_types().end() ) {
///       result = ret;
///     } else {
///       result = 0;
///     }
///   }
}

} // namespace ResolvExpr