source: translator/SymTab/Validate.cc @ 134b86a

/*
 * This file is part of the Cforall project
 *
 * $Id: Validate.cc,v 1.22 2005/08/29 20:14:18 rcbilson Exp $
 *
 */

/*
   The "validate" phase of translation is used to take a syntax tree and convert it into a
   standard form that aims to be as regular in structure as possible.  Some assumptions can be
   made regarding the state of the tree after this pass is complete, including:

   - No nested structure or union definitions; any in the input are "hoisted" to the level of
     the containing struct or union.

   - All enumeration constants have type EnumInstType.

   - The type "void" never occurs in lists of function parameter or return types; neither do
     tuple types.  A function taking no arguments has no argument types, and tuples are flattened.

   - No context instances exist; they are all replaced by the set of declarations signified by
     the context, instantiated by the particular set of type arguments.

   - Every declaration is assigned a unique id.

   - No typedef declarations or instances exist; the actual type is substituted for each instance.

   - Each type, struct, and union definition is followed by an appropriate assignment operator.

   - Each use of a struct or union is connected to a complete definition of that struct or union,
     even if that definition occurs later in the input.
*/

#include <list>
#include <iterator>
#include "Validate.h"
#include "SynTree/Visitor.h"
#include "SynTree/Mutator.h"
#include "SynTree/Type.h"
#include "SynTree/Statement.h"
#include "Indexer.h"
#include "SynTree/TypeSubstitution.h"
#include "FixFunction.h"
#include "ImplementationType.h"
#include "utility.h"
#include "UniqueName.h"
#include "AddVisit.h"


#define debugPrint(x) if( doDebug ) { std::cout << x; }

namespace SymTab {

class HoistStruct : public Visitor
{
public:
  static void hoistStruct( std::list< Declaration* > &translationUnit );
  
  std::list< Declaration* > &get_declsToAdd() { return declsToAdd; }
  
  virtual void visit(StructDecl *aggregateDecl);
  virtual void visit(UnionDecl *aggregateDecl);

  virtual void visit(CompoundStmt *compoundStmt);
  virtual void visit(IfStmt *ifStmt);
  virtual void visit(WhileStmt *whileStmt);
  virtual void visit(ForStmt *forStmt);
  virtual void visit(SwitchStmt *switchStmt);
  virtual void visit(ChooseStmt *chooseStmt);
  virtual void visit(CaseStmt *caseStmt);
  virtual void visit(CatchStmt *catchStmt);
  
private:
  HoistStruct();

  template< typename AggDecl > void handleAggregate( AggDecl *aggregateDecl );

  std::list< Declaration* > declsToAdd;
  bool inStruct;
};

class Pass1 : public Visitor
{
  typedef Visitor Parent;
  virtual void visit( EnumDecl *aggregateDecl);
  virtual void visit( FunctionType *func );
};
  
class Pass2 : public Indexer
{
  typedef Indexer Parent;

public:
  Pass2( bool doDebug, const Indexer *indexer );

private:
  virtual void visit( StructInstType *structInst );
  virtual void visit( UnionInstType *unionInst );
  virtual void visit( ContextInstType *contextInst );
  virtual void visit( StructDecl *structDecl );
  virtual void visit( UnionDecl *unionDecl );
  virtual void visit( TypeInstType *typeInst );

  const Indexer *indexer;
  
  typedef std::map< std::string, std::list< StructInstType* > > ForwardStructsType;
  typedef std::map< std::string, std::list< UnionInstType* > > ForwardUnionsType;
  ForwardStructsType forwardStructs;
  ForwardUnionsType forwardUnions;
};

class Pass3 : public Indexer
{
  typedef Indexer Parent;

public:
  Pass3( const Indexer *indexer );

private:
  virtual void visit( ObjectDecl *object );
  virtual void visit( FunctionDecl *func );

  const Indexer *indexer;
};

class AddStructAssignment : public Visitor
{
public:
  static void addStructAssignment( std::list< Declaration* > &translationUnit );

  std::list< Declaration* > &get_declsToAdd() { return declsToAdd; }
  
  virtual void visit( StructDecl *structDecl );
  virtual void visit( UnionDecl *structDecl );
  virtual void visit( TypeDecl *typeDecl );
  virtual void visit( ContextDecl *ctxDecl );

  virtual void visit( FunctionType *ftype );
  virtual void visit( PointerType *ftype );
  
  virtual void visit(CompoundStmt *compoundStmt);
  virtual void visit(IfStmt *ifStmt);
  virtual void visit(WhileStmt *whileStmt);
  virtual void visit(ForStmt *forStmt);
  virtual void visit(SwitchStmt *switchStmt);
  virtual void visit(ChooseStmt *chooseStmt);
  virtual void visit(CaseStmt *caseStmt);
  virtual void visit(CatchStmt *catchStmt);
  
private:
  template< typename StmtClass > void visitStatement(StmtClass *stmt);
  
  std::list< Declaration* > declsToAdd;
  std::set< std::string > structsDone;
};

class EliminateTypedef : public Mutator
{
public:
  static void eliminateTypedef( std::list< Declaration* > &translationUnit );
  
private:
  virtual Declaration* mutate(TypedefDecl *typeDecl);
  virtual TypeDecl* mutate(TypeDecl *typeDecl);
  virtual DeclarationWithType* mutate(FunctionDecl *funcDecl);
  virtual ObjectDecl* mutate(ObjectDecl *objDecl);
  virtual CompoundStmt* mutate(CompoundStmt *compoundStmt);
  virtual Type* mutate(TypeInstType *aggregateUseType);
  virtual Expression* mutate(CastExpr *castExpr);
  
  std::map< std::string, TypedefDecl* > typedefNames;
};

void 
validate( std::list< Declaration* > &translationUnit, bool doDebug, const Indexer *indexer )
{
  Pass1 pass1;
  Pass2 pass2( doDebug, indexer );
  Pass3 pass3( indexer );
  EliminateTypedef::eliminateTypedef( translationUnit );
  HoistStruct::hoistStruct( translationUnit );
  acceptAll( translationUnit, pass1 );
  acceptAll( translationUnit, pass2 );
  AddStructAssignment::addStructAssignment( translationUnit );
  acceptAll( translationUnit, pass3 );
}

void
validateType( Type *type, const Indexer *indexer )
{
  Pass1 pass1;
  Pass2 pass2( false, indexer );
  Pass3 pass3( indexer );
  type->accept( pass1 );
  type->accept( pass2 );
  type->accept( pass3 );
}

template< typename Visitor >
void
acceptAndAdd( std::list< Declaration* > &translationUnit, Visitor &visitor, bool addBefore )
{
  std::list< Declaration* >::iterator i = translationUnit.begin();
  while( i != translationUnit.end() ) {
    (*i)->accept( visitor );
    std::list< Declaration* >::iterator next = i;
    next++;
    if( !visitor.get_declsToAdd().empty() ) {
      translationUnit.splice( addBefore ? i : next, visitor.get_declsToAdd() );
    }
    i = next;
  }
}

/* static class method */
void 
HoistStruct::hoistStruct( std::list< Declaration* > &translationUnit )
{
  HoistStruct hoister;
  acceptAndAdd( translationUnit, hoister, true );
}

HoistStruct::HoistStruct()
  : inStruct( false )
{
}

void
filter( std::list< Declaration* > &declList, bool (*pred)( Declaration* ), bool doDelete )
{
  std::list< Declaration* >::iterator i = declList.begin();
  while( i != declList.end() ) {
    std::list< Declaration* >::iterator next = i;
    ++next;
    if( pred( *i ) ) {
      if( doDelete ) {
        delete *i;
      }
      declList.erase( i );
    }
    i = next;
  }
}

bool
isStructOrUnion( Declaration *decl )
{
  return dynamic_cast< StructDecl* >( decl ) || dynamic_cast< UnionDecl* >( decl );
}

template< typename AggDecl >
void
HoistStruct::handleAggregate( AggDecl *aggregateDecl )
{
  if( inStruct ) {
    declsToAdd.push_back( aggregateDecl );
    Visitor::visit( aggregateDecl );
  } else {
    inStruct = true;
    Visitor::visit( aggregateDecl );
    inStruct = false;
    filter( aggregateDecl->get_members(), isStructOrUnion, false );
  }
}

void 
HoistStruct::visit(StructDecl *aggregateDecl)
{
  handleAggregate( aggregateDecl );
}

void 
HoistStruct::visit(UnionDecl *aggregateDecl)
{
  handleAggregate( aggregateDecl );
}

void
HoistStruct::visit(CompoundStmt *compoundStmt)
{
  addVisit( compoundStmt, *this );
}

void
HoistStruct::visit(IfStmt *ifStmt)
{
  addVisit( ifStmt, *this );
}

void
HoistStruct::visit(WhileStmt *whileStmt)
{
  addVisit( whileStmt, *this );
}

void
HoistStruct::visit(ForStmt *forStmt)
{
  addVisit( forStmt, *this );
}

void
HoistStruct::visit(SwitchStmt *switchStmt)
{
  addVisit( switchStmt, *this );
}

void
HoistStruct::visit(ChooseStmt *switchStmt)
{
  addVisit( switchStmt, *this );
}

void
HoistStruct::visit(CaseStmt *caseStmt)
{
  addVisit( caseStmt, *this );
}

void
HoistStruct::visit(CatchStmt *cathStmt)
{
  addVisit( cathStmt, *this );
}

void 
Pass1::visit( EnumDecl *enumDecl)
{
  // Set the type of each member of the enumeration to be EnumConstant
  
  for( std::list< Declaration* >::iterator i = enumDecl->get_members().begin(); i != enumDecl->get_members().end(); ++i ) {
    ObjectDecl *obj = dynamic_cast< ObjectDecl* >( *i );
    assert( obj );
    obj->set_type( new EnumInstType( Type::Qualifiers( true, false, false, false ), enumDecl->get_name() ) );
  }
  Parent::visit( enumDecl );
}

namespace {
template< typename DWTIterator >
void
fixFunctionList( DWTIterator begin, DWTIterator end, FunctionType *func )
{
  // the only case in which "void" is valid is where it is the only one in the list; then
  // it should be removed entirely
  // other fix ups are handled by the FixFunction class
  if( begin == end ) return;
  FixFunction fixer;
  DWTIterator i = begin;
  *i = (*i)->acceptMutator( fixer );
  if( fixer.get_isVoid() ) {
    DWTIterator j = i;
    ++i;
    func->get_parameters().erase( j );
    if( i != end ) { 
      throw SemanticError( "invalid type void in function type ", func );
    }
  } else {
    ++i;
    for( ; i != end; ++i ) {
      FixFunction fixer;
      *i = (*i)->acceptMutator( fixer );
      if( fixer.get_isVoid() ) {
        throw SemanticError( "invalid type void in function type ", func );
      }
    }
  }
}
}

void 
Pass1::visit( FunctionType *func )
{
  // Fix up parameters and return types
  fixFunctionList( func->get_parameters().begin(), func->get_parameters().end(), func );
  fixFunctionList( func->get_returnVals().begin(), func->get_returnVals().end(), func );
  Visitor::visit( func );
}

Pass2::Pass2( bool doDebug, const Indexer *other_indexer )
  : Indexer( doDebug )
{
  if( other_indexer ) {
    indexer = other_indexer;
  } else {
    indexer = this;
  }
}

void 
Pass2::visit( StructInstType *structInst )
{
  Parent::visit( structInst );
  StructDecl *st = indexer->lookupStruct( structInst->get_name() );
  // it's not a semantic error if the struct is not found, just an implicit forward declaration
  if( st ) {
    assert( !structInst->get_baseStruct() || structInst->get_baseStruct()->get_members().empty() || !st->get_members().empty() );
    structInst->set_baseStruct( st );
  }
  if( !st || st->get_members().empty() ) {
    // use of forward declaration
    forwardStructs[ structInst->get_name() ].push_back( structInst );
  }
}

void 
Pass2::visit( UnionInstType *unionInst )
{
  Parent::visit( unionInst );
  UnionDecl *un = indexer->lookupUnion( unionInst->get_name() );
  // it's not a semantic error if the union is not found, just an implicit forward declaration
  if( un ) {
    unionInst->set_baseUnion( un );
  }
  if( !un || un->get_members().empty() ) {
    // use of forward declaration
    forwardUnions[ unionInst->get_name() ].push_back( unionInst );
  }
}

void 
Pass2::visit( ContextInstType *contextInst )
{
  Parent::visit( contextInst );
  ContextDecl *ctx = indexer->lookupContext( contextInst->get_name() );
  if( !ctx ) {
    throw SemanticError( "use of undeclared context " + contextInst->get_name() );
  }
  for( std::list< TypeDecl* >::const_iterator i = ctx->get_parameters().begin(); i != ctx->get_parameters().end(); ++i ) {
    for( std::list< DeclarationWithType* >::const_iterator assert = (*i)->get_assertions().begin(); assert != (*i)->get_assertions().end(); ++assert ) {
      if( ContextInstType *otherCtx = dynamic_cast< ContextInstType* >(*assert) ) {
        cloneAll( otherCtx->get_members(), contextInst->get_members() );
      } else {
        contextInst->get_members().push_back( (*assert)->clone() );
      }
    }
  }
  applySubstitution( ctx->get_parameters().begin(), ctx->get_parameters().end(), contextInst->get_parameters().begin(), ctx->get_members().begin(), ctx->get_members().end(), back_inserter( contextInst->get_members() ) );
}

void 
Pass2::visit( StructDecl *structDecl )
{
  if( !structDecl->get_members().empty() ) {
    ForwardStructsType::iterator fwds = forwardStructs.find( structDecl->get_name() );
    if( fwds != forwardStructs.end() ) {
      for( std::list< StructInstType* >::iterator inst = fwds->second.begin(); inst != fwds->second.end(); ++inst ) {
        (*inst)->set_baseStruct( structDecl );
      }
      forwardStructs.erase( fwds );
    }
  }
  Indexer::visit( structDecl );
}

void 
Pass2::visit( UnionDecl *unionDecl )
{
  if( !unionDecl->get_members().empty() ) {
    ForwardUnionsType::iterator fwds = forwardUnions.find( unionDecl->get_name() );
    if( fwds != forwardUnions.end() ) {
      for( std::list< UnionInstType* >::iterator inst = fwds->second.begin(); inst != fwds->second.end(); ++inst ) {
        (*inst)->set_baseUnion( unionDecl );
      }
      forwardUnions.erase( fwds );
    }
  }
  Indexer::visit( unionDecl );
}

void 
Pass2::visit( TypeInstType *typeInst )
{
  if( NamedTypeDecl *namedTypeDecl = lookupType( typeInst->get_name() ) ) {
    if( TypeDecl *typeDecl = dynamic_cast< TypeDecl* >( namedTypeDecl ) ) {
      typeInst->set_isFtype( typeDecl->get_kind() == TypeDecl::Ftype );
    }
  }
}

Pass3::Pass3( const Indexer *other_indexer )
  : Indexer( false )
{
  if( other_indexer ) {
    indexer = other_indexer;
  } else {
    indexer = this;
  }
}

void 
forallFixer( Type *func )
{
  // Fix up assertions
  for( std::list< TypeDecl* >::iterator type = func->get_forall().begin(); type != func->get_forall().end(); ++type ) {
    std::list< DeclarationWithType* > toBeDone, nextRound;
    toBeDone.splice( toBeDone.end(), (*type)->get_assertions() );
    while( !toBeDone.empty() ) {
      for( std::list< DeclarationWithType* >::iterator assertion = toBeDone.begin(); assertion != toBeDone.end(); ++assertion ) {
        if( ContextInstType *ctx = dynamic_cast< ContextInstType* >( (*assertion)->get_type() ) ) {
          for( std::list< Declaration* >::const_iterator i = ctx->get_members().begin(); i != ctx->get_members().end(); ++i ) {
            DeclarationWithType *dwt = dynamic_cast< DeclarationWithType* >( *i );
            assert( dwt );
            nextRound.push_back( dwt->clone() );
          }
          delete ctx;
        } else {
          FixFunction fixer;
          *assertion = (*assertion)->acceptMutator( fixer );
          if( fixer.get_isVoid() ) {
            throw SemanticError( "invalid type void in assertion of function ", func );
          }
          (*type)->get_assertions().push_back( *assertion );
        }
      }
      toBeDone.clear();
      toBeDone.splice( toBeDone.end(), nextRound );
    }
  }
}

void 
Pass3::visit( ObjectDecl *object )
{
  forallFixer( object->get_type() );
  if( PointerType *pointer = dynamic_cast< PointerType* >( object->get_type() ) ) {
    forallFixer( pointer->get_base() );
  }
  Parent::visit( object );
  object->fixUniqueId();
}

void 
Pass3::visit( FunctionDecl *func )
{
  forallFixer( func->get_type() );
  Parent::visit( func );
  func->fixUniqueId();
}

static const std::list< std::string > noLabels;

/* static class method */
void
AddStructAssignment::addStructAssignment( std::list< Declaration* > &translationUnit )
{
  AddStructAssignment visitor;
  acceptAndAdd( translationUnit, visitor, false );
}

template< typename OutputIterator >
void
makeScalarAssignment( ObjectDecl *srcParam, ObjectDecl *dstParam, DeclarationWithType *member, OutputIterator out )
{
  ObjectDecl *obj = dynamic_cast<ObjectDecl *>( member ); // PAB: unnamed bit fields are not copied
  if ( obj != NULL && obj->get_name() == "" && obj->get_bitfieldWidth() != NULL ) return;

  UntypedExpr *assignExpr = new UntypedExpr( new NameExpr( "?=?" ) );
  
  UntypedExpr *derefExpr = new UntypedExpr( new NameExpr( "*?" ) );
  derefExpr->get_args().push_back( new VariableExpr( dstParam ) );
  
  // do something special for unnamed members
  Expression *dstselect = new AddressExpr( new MemberExpr( member, derefExpr ) );
  assignExpr->get_args().push_back( dstselect );
  
  Expression *srcselect = new MemberExpr( member, new VariableExpr( srcParam ) );
  assignExpr->get_args().push_back( srcselect );
  
  *out++ = new ExprStmt( noLabels, assignExpr );
}

template< typename OutputIterator >
void
makeArrayAssignment( ObjectDecl *srcParam, ObjectDecl *dstParam, DeclarationWithType *member, ArrayType *array, OutputIterator out )
{
  static UniqueName indexName( "_index" );
  
  // for a flexible array member nothing is done -- user must define own assignment
  if( !array->get_dimension() ) return;
  
  ObjectDecl *index = new ObjectDecl( indexName.newName(), Declaration::NoStorageClass, LinkageSpec::C, 0, new BasicType( Type::Qualifiers(), BasicType::SignedInt ), 0 );
  *out++ = new DeclStmt( noLabels, index );
  
  UntypedExpr *init = new UntypedExpr( new NameExpr( "?=?" ) );
  init->get_args().push_back( new AddressExpr( new VariableExpr( index ) ) );
  init->get_args().push_back( new NameExpr( "0" ) );
  Statement *initStmt = new ExprStmt( noLabels, init );
  
  UntypedExpr *cond = new UntypedExpr( new NameExpr( "?<?" ) );
  cond->get_args().push_back( new VariableExpr( index ) );
  cond->get_args().push_back( array->get_dimension()->clone() );
  
  UntypedExpr *inc = new UntypedExpr( new NameExpr( "++?" ) );
  inc->get_args().push_back( new AddressExpr( new VariableExpr( index ) ) );
  
  UntypedExpr *assignExpr = new UntypedExpr( new NameExpr( "?=?" ) );
  
  UntypedExpr *derefExpr = new UntypedExpr( new NameExpr( "*?" ) );
  derefExpr->get_args().push_back( new VariableExpr( dstParam ) );
  
  Expression *dstselect = new MemberExpr( member, derefExpr );
  UntypedExpr *dstIndex = new UntypedExpr( new NameExpr( "?+?" ) );
  dstIndex->get_args().push_back( dstselect );
  dstIndex->get_args().push_back( new VariableExpr( index ) );
  assignExpr->get_args().push_back( dstIndex );
  
  Expression *srcselect = new MemberExpr( member, new VariableExpr( srcParam ) );
  UntypedExpr *srcIndex = new UntypedExpr( new NameExpr( "?[?]" ) );
  srcIndex->get_args().push_back( srcselect );
  srcIndex->get_args().push_back( new VariableExpr( index ) );
  assignExpr->get_args().push_back( srcIndex );
  
  *out++ = new ForStmt( noLabels, initStmt, cond, inc, new ExprStmt( noLabels, assignExpr ) );
}

Declaration*
makeStructAssignment( StructDecl *aggregateDecl, StructInstType *refType )
{
  FunctionType *assignType = new FunctionType( Type::Qualifiers(), false );
  
  ObjectDecl *returnVal = new ObjectDecl( "", Declaration::NoStorageClass, LinkageSpec::Cforall, 0, refType->clone(), 0 );
  assignType->get_returnVals().push_back( returnVal );
  
  ObjectDecl *dstParam = new ObjectDecl( "_dst", Declaration::NoStorageClass, LinkageSpec::Cforall, 0, new PointerType( Type::Qualifiers(), refType->clone() ), 0 );
  assignType->get_parameters().push_back( dstParam );
  
  ObjectDecl *srcParam = new ObjectDecl( "_src", Declaration::NoStorageClass, LinkageSpec::Cforall, 0, refType, 0 );
  assignType->get_parameters().push_back( srcParam );
  
  FunctionDecl *assignDecl = new FunctionDecl( "?=?", Declaration::Static, LinkageSpec::AutoGen, assignType, new CompoundStmt( noLabels ), true );
  assignDecl->fixUniqueId();
  
  for( std::list< Declaration* >::const_iterator member = aggregateDecl->get_members().begin(); member != aggregateDecl->get_members().end(); ++member ) {
    if( DeclarationWithType *dwt = dynamic_cast< DeclarationWithType* >( *member ) ) {
      if( ArrayType *array = dynamic_cast< ArrayType* >( dwt->get_type() ) ) {
        makeArrayAssignment( srcParam, dstParam, dwt, array, back_inserter( assignDecl->get_statements()->get_kids() ) );
      } else {
        makeScalarAssignment( srcParam, dstParam, dwt, back_inserter( assignDecl->get_statements()->get_kids() ) );
      }
    }
  }
  assignDecl->get_statements()->get_kids().push_back( new ReturnStmt( noLabels, new VariableExpr( srcParam ) ) );
  
  return assignDecl;
}

Declaration*
makeUnionAssignment( UnionDecl *aggregateDecl, UnionInstType *refType )
{
  FunctionType *assignType = new FunctionType( Type::Qualifiers(), false );
  
  ObjectDecl *returnVal = new ObjectDecl( "", Declaration::NoStorageClass, LinkageSpec::Cforall, 0, refType->clone(), 0 );
  assignType->get_returnVals().push_back( returnVal );
  
  ObjectDecl *dstParam = new ObjectDecl( "_dst", Declaration::NoStorageClass, LinkageSpec::Cforall, 0, new PointerType( Type::Qualifiers(), refType->clone() ), 0 );
  assignType->get_parameters().push_back( dstParam );
  
  ObjectDecl *srcParam = new ObjectDecl( "_src", Declaration::NoStorageClass, LinkageSpec::Cforall, 0, refType, 0 );
  assignType->get_parameters().push_back( srcParam );
  
  FunctionDecl *assignDecl = new FunctionDecl( "?=?", Declaration::Static, LinkageSpec::AutoGen, assignType, new CompoundStmt( noLabels ), true );
  assignDecl->fixUniqueId();
  
  UntypedExpr *copy = new UntypedExpr( new NameExpr( "__builtin_memcpy" ) );
  copy->get_args().push_back( new VariableExpr( dstParam ) );
  copy->get_args().push_back( new AddressExpr( new VariableExpr( srcParam ) ) );
  copy->get_args().push_back( new SizeofExpr( refType->clone() ) );

  assignDecl->get_statements()->get_kids().push_back( new ExprStmt( noLabels, copy ) );
  assignDecl->get_statements()->get_kids().push_back( new ReturnStmt( noLabels, new VariableExpr( srcParam ) ) );
  
  return assignDecl;
}

void
AddStructAssignment::visit( StructDecl *structDecl )
{
  if( !structDecl->get_members().empty() && structsDone.find( structDecl->get_name() ) == structsDone.end() ) {
    StructInstType *structInst = new StructInstType( Type::Qualifiers(), structDecl->get_name() );
    structInst->set_baseStruct( structDecl );
    declsToAdd.push_back( makeStructAssignment( structDecl, structInst ) );
    structsDone.insert( structDecl->get_name() );
  }
}

void
AddStructAssignment::visit( UnionDecl *unionDecl )
{
  if( !unionDecl->get_members().empty() ) {
    UnionInstType *unionInst = new UnionInstType( Type::Qualifiers(), unionDecl->get_name() );
    unionInst->set_baseUnion( unionDecl );
    declsToAdd.push_back( makeUnionAssignment( unionDecl, unionInst ) );
  }
}

void
AddStructAssignment::visit( TypeDecl *typeDecl )
{
  CompoundStmt *stmts = 0;
  TypeInstType *typeInst = new TypeInstType( Type::Qualifiers(), typeDecl->get_name(), false );
  typeInst->set_baseType( typeDecl );
  ObjectDecl *src = new ObjectDecl( "_src", Declaration::NoStorageClass, LinkageSpec::Cforall, 0, typeInst->clone(), 0 );
  ObjectDecl *dst = new ObjectDecl( "_dst", Declaration::NoStorageClass, LinkageSpec::Cforall, 0, new PointerType( Type::Qualifiers(), typeInst->clone() ), 0 );
  if( typeDecl->get_base() ) {
    stmts = new CompoundStmt( std::list< Label >() );
    UntypedExpr *assign = new UntypedExpr( new NameExpr( "?=?" ) );
    assign->get_args().push_back( new CastExpr( new VariableExpr( dst ), new PointerType( Type::Qualifiers(), typeDecl->get_base()->clone() ) ) );
    assign->get_args().push_back( new CastExpr( new VariableExpr( src ), typeDecl->get_base()->clone() ) );
    stmts->get_kids().push_back( new ReturnStmt( std::list< Label >(), assign ) );
  }
  FunctionType *type = new FunctionType( Type::Qualifiers(), false );
  type->get_returnVals().push_back( new ObjectDecl( "", Declaration::NoStorageClass, LinkageSpec::Cforall, 0, typeInst, 0 ) );
  type->get_parameters().push_back( dst );
  type->get_parameters().push_back( src );
  FunctionDecl *func = new FunctionDecl( "?=?", Declaration::NoStorageClass, LinkageSpec::AutoGen, type, stmts, false );
  declsToAdd.push_back( func );
}

void
addDecls( std::list< Declaration* > &declsToAdd, std::list< Statement* > &statements, std::list< Statement* >::iterator i )
{
  if( !declsToAdd.empty() ) {
    for( std::list< Declaration* >::iterator decl = declsToAdd.begin(); decl != declsToAdd.end(); ++decl ) {
      statements.insert( i, new DeclStmt( noLabels, *decl ) );
    }
    declsToAdd.clear();
  }
}

void
AddStructAssignment::visit(FunctionType *)
{
  // ensure that we don't add assignment ops for types defined
  // as part of the function
}

void
AddStructAssignment::visit(PointerType *)
{
  // ensure that we don't add assignment ops for types defined
  // as part of the pointer
}

void
AddStructAssignment::visit(ContextDecl *)
{
  // ensure that we don't add assignment ops for types defined
  // as part of the context
}

template< typename StmtClass >
inline void
AddStructAssignment::visitStatement(StmtClass *stmt)
{
  std::set< std::string > oldStructs = structsDone;
  addVisit( stmt, *this );
  structsDone = oldStructs;
}

void
AddStructAssignment::visit(CompoundStmt *compoundStmt)
{
  visitStatement( compoundStmt );
}

void
AddStructAssignment::visit(IfStmt *ifStmt)
{
  visitStatement( ifStmt );
}

void
AddStructAssignment::visit(WhileStmt *whileStmt)
{
  visitStatement( whileStmt );
}

void
AddStructAssignment::visit(ForStmt *forStmt)
{
  visitStatement( forStmt );
}

void
AddStructAssignment::visit(SwitchStmt *switchStmt)
{
  visitStatement( switchStmt );
}

void
AddStructAssignment::visit(ChooseStmt *switchStmt)
{
  visitStatement( switchStmt );
}

void
AddStructAssignment::visit(CaseStmt *caseStmt)
{
  visitStatement( caseStmt );
}

void
AddStructAssignment::visit(CatchStmt *cathStmt)
{
  visitStatement( cathStmt );
}

bool
isTypedef( Declaration *decl )
{
  return dynamic_cast< TypedefDecl* >( decl );
}


/* static class method */
void 
EliminateTypedef::eliminateTypedef( std::list< Declaration* > &translationUnit )
{
  EliminateTypedef eliminator;
  mutateAll( translationUnit, eliminator );
  filter( translationUnit, isTypedef, true );
}

Type*
EliminateTypedef::mutate( TypeInstType *typeInst )
{
  std::map< std::string, TypedefDecl* >::const_iterator def = typedefNames.find( typeInst->get_name() );
  if( def != typedefNames.end() ) {
    Type *ret = def->second->get_base()->clone();
    ret->get_qualifiers() += typeInst->get_qualifiers();
    delete typeInst;
    return ret;
  }
  return typeInst;
}

Declaration*
EliminateTypedef::mutate( TypedefDecl *tyDecl )
{
  Declaration *ret = Mutator::mutate( tyDecl );
  typedefNames[ tyDecl->get_name() ] = tyDecl;
  if( AggregateDecl *aggDecl = dynamic_cast< AggregateDecl* >( tyDecl->get_base() ) ) {
    tyDecl->set_base( 0 );
    delete tyDecl;
    return aggDecl;
  } else {
    return ret;
  }
}

TypeDecl*
EliminateTypedef::mutate(TypeDecl *typeDecl)
{
  std::map< std::string, TypedefDecl* >::iterator i = typedefNames.find( typeDecl->get_name() );
  if( i != typedefNames.end() ) {
    typedefNames.erase( i ) ;
  }
  return typeDecl;
}

DeclarationWithType*
EliminateTypedef::mutate(FunctionDecl *funcDecl)
{
  std::map< std::string, TypedefDecl* > oldNames = typedefNames;
  DeclarationWithType *ret = Mutator::mutate( funcDecl );
  typedefNames = oldNames;
  return ret;
}

ObjectDecl*
EliminateTypedef::mutate(ObjectDecl *objDecl)
{
  std::map< std::string, TypedefDecl* > oldNames = typedefNames;
  ObjectDecl *ret = Mutator::mutate( objDecl );
  typedefNames = oldNames;
  return ret;
}

Expression*
EliminateTypedef::mutate(CastExpr *castExpr)
{
  std::map< std::string, TypedefDecl* > oldNames = typedefNames;
  Expression *ret = Mutator::mutate( castExpr );
  typedefNames = oldNames;
  return ret;
}

CompoundStmt * 
EliminateTypedef::mutate( CompoundStmt *compoundStmt )
{
  std::map< std::string, TypedefDecl* > oldNames = typedefNames;
  CompoundStmt *ret = Mutator::mutate( compoundStmt );
  std::list< Statement* >::iterator i = compoundStmt->get_kids().begin();
  while( i != compoundStmt->get_kids().end() ) {
    std::list< Statement* >::iterator next = i;
    ++next;
    if( DeclStmt *declStmt = dynamic_cast< DeclStmt* >( *i ) ) {
      if( dynamic_cast< TypedefDecl* >( declStmt->get_decl() ) ) {
        delete *i;
        compoundStmt->get_kids().erase( i );
      }
    }
    i = next;
  }
  typedefNames = oldNames;
  return ret;
}

} // namespace SymTab