lib/Target/CBackend/CBackend.cpp

//===-- Writer.cpp - Library for writing C files -----------------*- C++ -*--=//
//
// This library implements the functionality defined in llvm/Assembly/CWriter.h
// and CLocalVars.h
//
// TODO : Recursive types.
//===-----------------------------------------------------------------------==//
#include "llvm/Assembly/CWriter.h"
#include "CLocalVars.h"
#include "llvm/SlotCalculator.h"
#include "llvm/Module.h"
#include "llvm/Argument.h"
#include "llvm/Function.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Constants.h"
#include "llvm/GlobalVariable.h"
#include "llvm/BasicBlock.h"
#include "llvm/iMemory.h"
#include "llvm/iTerminators.h"
#include "llvm/iPHINode.h"
#include "llvm/iOther.h"
#include "llvm/SymbolTable.h"
#include "llvm/Support/InstVisitor.h"
#include "Support/StringExtras.h"
#include "Support/STLExtras.h"

#include <algorithm>
#include <strstream>
using std::string;
using std::map;
using std::vector;
using std::ostream;

/* Implementation of the CLocalVars methods */

// Appends a variable to the LocalVars map if it does not already exist
// Also check that the type exists on the map.
void CLocalVars::addLocalVar(const Type *t, const string & var) {
  if (!LocalVars.count(t) || 
      find(LocalVars[t].begin(), LocalVars[t].end(), var) 
      == LocalVars[t].end()) {
      LocalVars[t].push_back(var);
  } 
}

/* Writer.cpp */
static string calcTypeNameVar(const Type *Ty, vector<const Type *> &TypeStack,
			      map<const Type *, string> &TypeNames, 
			      string VariableName, string NameSoFar);

static std::string getConstStrValue(const Constant* CPV);


//
//Getting opcodes in terms of the operator
//
static const char *getOpcodeOperName(const Instruction *I) {
  switch (I->getOpcode()) {
  // Standard binary operators...
  case Instruction::Add: return "+";
  case Instruction::Sub: return "-";
  case Instruction::Mul: return "*";
  case Instruction::Div: return "/";
  case Instruction::Rem: return "%";
    
    // Logical operators...
  case Instruction::And: return "&";
  case Instruction::Or: return "|";
  case Instruction::Xor: return "^";
    
    // SetCond operators...
  case Instruction::SetEQ: return "==";
  case Instruction::SetNE: return "!=";
  case Instruction::SetLE: return "<=";
  case Instruction::SetGE: return ">=";
  case Instruction::SetLT: return "<";
  case Instruction::SetGT: return ">";
    
    //ShiftInstruction...
    
  case Instruction::Shl : return "<<";
  case Instruction::Shr : return ">>";
    
  default:
    cerr << "Invalid operator type!" << I->getOpcode() << "\n";
    abort();
  }
  return 0;
}


// We dont want identifier names with ., space, -  in them. 
// So we replace them with _
static string makeNameProper(string x) {
  string tmp;
  for (string::iterator sI = x.begin(), sEnd = x.end(); sI != sEnd; sI++) {
    if (*sI == '.')
      tmp += '_';
    else if (*sI == ' ')
      tmp += '_';
    else if (*sI == '-')
      tmp += "__";
    else
      tmp += *sI;
  }
  return tmp;
}

static string getConstantName(const Constant *CPV) {
  return CPV->getName();
}


static std::string getConstArrayStrValue(const Constant* CPV) {
  std::string Result;
  
  // As a special case, print the array as a string if it is an array of
  // ubytes or an array of sbytes with positive values.
  // 
  const Type *ETy = cast<ArrayType>(CPV->getType())->getElementType();
  bool isString = (ETy == Type::SByteTy || ETy == Type::UByteTy);

  if (ETy == Type::SByteTy) {
    for (unsigned i = 0; i < CPV->getNumOperands(); ++i)
      if (ETy == Type::SByteTy &&
          cast<ConstantSInt>(CPV->getOperand(i))->getValue() < 0) {
        isString = false;
        break;
      }
  }
  
  if (isString) {
    Result = "\"";
    for (unsigned i = 0; i < CPV->getNumOperands(); ++i) {
      unsigned char C = (ETy == Type::SByteTy) ?
        (unsigned char)cast<ConstantSInt>(CPV->getOperand(i))->getValue() :
        (unsigned char)cast<ConstantUInt>(CPV->getOperand(i))->getValue();
      
      if (isprint(C)) {
        Result += C;
      } else {
        Result += '\\';
	Result += 'x';
        Result += ( C/16  < 10) ? ( C/16 +'0') : ( C/16 -10+'A');
        Result += ((C&15) < 10) ? ((C&15)+'0') : ((C&15)-10+'A');
      }
    }
    Result += "\"";
    
  } else {
    Result = "{";
    if (CPV->getNumOperands()) {
      Result += " " +  getConstStrValue(cast<Constant>(CPV->getOperand(0)));
      for (unsigned i = 1; i < CPV->getNumOperands(); i++)
        Result += ", " + getConstStrValue(cast<Constant>(CPV->getOperand(i)));
    }
    Result += " }";
  }
  
  return Result;
}

static std::string getConstStructStrValue(const Constant* CPV) {
  std::string Result = "{";
  if (CPV->getNumOperands()) {
    Result += " " + getConstStrValue(cast<Constant>(CPV->getOperand(0)));
    for (unsigned i = 1; i < CPV->getNumOperands(); i++)
      Result += ", " + getConstStrValue(cast<Constant>(CPV->getOperand(i)));
  }

  return Result + " }";
}

// our own getStrValue function for constant initializers
static std::string getConstStrValue(const Constant* CPV) {
  // Does not handle null pointers, that needs to be checked explicitly
  string tempstr;
  if (CPV == ConstantBool::False)
    return "0";
  else if (CPV == ConstantBool::True)
    return "1";
  
  else if (isa<ConstantArray>(CPV)) {
    tempstr = getConstArrayStrValue(CPV);
  }
  else  if (isa<ConstantStruct>(CPV)) {
    tempstr = getConstStructStrValue(CPV);
  }
  else if (ConstantUInt *CUI = dyn_cast<ConstantUInt>(CPV)) {
    tempstr = utostr((long long unsigned int) CUI->getValue());
  } 
  else if (ConstantSInt *CSI = dyn_cast<ConstantSInt>(CPV)) {
    tempstr = itostr(CSI->getValue());
  }
  else if (ConstantFP *CFP = dyn_cast<ConstantFP>(CPV)) {
    tempstr = ftostr(CFP->getValue());
  }
  
  if (CPV->getType() == Type::ULongTy)
    tempstr += "ull";
  else if (CPV->getType() == Type::LongTy)
    tempstr += "ll";
  else if (CPV->getType() == Type::UIntTy ||
	   CPV->getType() == Type::UShortTy)
    tempstr += "u";
  
  return tempstr;

}

// WriteCOperand - Write the name of the specified value out to the specified
// ostream.  This can be useful when you just want to print int %0 not the
// whole instruction that generated it.
//
static void WriteCOperandInternal(ostream &Out, const Value *V, 
				  bool PrintName, SlotCalculator *Table, 
				  string &OperandType) {
  int Slot;
  if (PrintName && V->hasName()) {   
    // If V has a name.
    Out << "llvm__" << makeNameProper(V->getName()) << "_" << 
      (V->getType())->getUniqueID();
    return;
  } 
  else if (const Constant *CPV = dyn_cast<const Constant>(V)) {
    if (isa<ConstantPointerNull>(CPV)) {
      Out << "(" << OperandType << ")0";
    }
    else
      Out << getConstStrValue(CPV); 
  }
  else {
    Slot = Table->getValSlot(V);
    if (Slot >= 0)  
      Out << "llvm__tmp_" << Slot << "_" << V->getType()->getUniqueID();
    else if (PrintName)
      Out << "<badref>";
  }
}

// Internal function
// Essentially pass the Type* variable, an empty typestack and this prints 
// out the C type
static string calcTypeName(const Type *Ty, vector<const Type *> &TypeStack,
                           map<const Type *, string> &TypeNames,
			   string *FunctionInfo) {
  
  // Takin' care of the fact that boolean would be int in C
  // and that ushort would be unsigned short etc.
  
  // Base Case
  if (Ty->isPrimitiveType())
    switch (Ty->getPrimitiveID()) {
    case Type::BoolTyID: 
      return "int";
      break;
    case Type::UByteTyID:
      return "unsigned char";
      break;
    case Type::SByteTyID:
      return "signed char";
      break;
    case Type::UShortTyID:
      return "unsigned long long";
      break;
    case Type::ULongTyID:
      return "unsigned long long";
      break;
    case Type::LongTyID:
      return "signed long long";
      break;
    case Type::UIntTyID:
      return "unsigned int";
      break;
    default :
      return Ty->getDescription(); 
    }
  
  // Check to see if the type is named.
  map<const Type *, string>::iterator I = TypeNames.find(Ty);
  if (I != TypeNames.end())
    return I->second;
  
  // Check to see if the Type is already on the stack...
  unsigned Slot = 0, CurSize = TypeStack.size();
  while (Slot < CurSize && TypeStack[Slot] != Ty) ++Slot; // Scan for type
  
  // This is another base case for the recursion.  In this case, we know 
  // that we have looped back to a type that we have previously visited.
  // Generate the appropriate upreference to handle this.
  // 
  if (Slot < CurSize)
    return "\\" + utostr(CurSize-Slot);       // Here's the upreference

  TypeStack.push_back(Ty);    // Recursive case: Add us to the stack..
  
  string Result;
  string MInfo = "";
  switch (Ty->getPrimitiveID()) {
  case Type::FunctionTyID: {
    const FunctionType *MTy = cast<const FunctionType>(Ty);
    Result = calcTypeName(MTy->getReturnType(), TypeStack, TypeNames, &MInfo);
    if (MInfo != "")
      Result += ") " + MInfo;
    Result += "(";
    *FunctionInfo += " (";
    for (FunctionType::ParamTypes::const_iterator
           I = MTy->getParamTypes().begin(),
           E = MTy->getParamTypes().end(); I != E; ++I) {
      if (I != MTy->getParamTypes().begin())
        *FunctionInfo += ", ";
      MInfo = "";
      *FunctionInfo += calcTypeName(*I, TypeStack, TypeNames, &MInfo);
      if (MInfo != "")
	Result += ") " + MInfo;
    }
    if (MTy->isVarArg()) {
      if (!MTy->getParamTypes().empty()) 
	*FunctionInfo += ", ";
      *FunctionInfo += "...";
    }
    *FunctionInfo += ")";
    break;
  }
  case Type::StructTyID: {
    string tempstr = "";
    const StructType *STy = cast<const StructType>(Ty);
    Result = " struct {\n ";
    int indx = 0;
    for (StructType::ElementTypes::const_iterator
           I = STy->getElementTypes().begin(),
           E = STy->getElementTypes().end(); I != E; ++I) {
      Result += calcTypeNameVar(*I, TypeStack, TypeNames, 
				"field" + itostr(indx++), tempstr);
      Result += ";\n ";
    }
    Result += " } ";
    break;
  }
  case Type::PointerTyID:
    Result = calcTypeName(cast<const PointerType>(Ty)->getElementType(), 
                          TypeStack, TypeNames, &MInfo);
    Result += "*";
    break;
  case Type::ArrayTyID: {
    const ArrayType *ATy = cast<const ArrayType>(Ty);
    int NumElements = ATy->getNumElements();
    Result = calcTypeName(ATy->getElementType(), TypeStack, TypeNames, &MInfo);
    Result += "*";
    break;
  }
  default:
    assert(0 && "Unhandled case in getTypeProps!");
    Result = "<error>";
  }

  TypeStack.pop_back();       // Remove self from stack...
  return Result;
}

// Internal function
// Pass the Type* variable and and the variable name and this prints out the 
// variable declaration.
// This is different from calcTypeName because if you need to declare an array
// the size of the array would appear after the variable name itself
// For eg. int a[10];
static string calcTypeNameVar(const Type *Ty, vector<const Type *> &TypeStack,
			      map<const Type *, string> &TypeNames, 
			      string VariableName, string NameSoFar) {
  if (Ty->isPrimitiveType())
    switch (Ty->getPrimitiveID()) {
    case Type::BoolTyID: 
      return "int " + NameSoFar + VariableName;
      break;
    case Type::UByteTyID: 
      return "unsigned char " + NameSoFar + VariableName;
      break;
    case Type::SByteTyID:
      return "signed char " + NameSoFar + VariableName;
      break;
    case Type::UShortTyID:
      return "unsigned long long " + NameSoFar + VariableName;
      break;
    case Type::ULongTyID:
      return "unsigned long long " + NameSoFar + VariableName;
      break;
    case Type::LongTyID:
      return "signed long long " + NameSoFar + VariableName;
      break;
    case Type::UIntTyID:
      return "unsigned int " + NameSoFar + VariableName;
      break;
    default :
      return Ty->getDescription() + " " + NameSoFar + VariableName; 
    }
  
  // Check to see if the type is named.
  map<const Type *, string>::iterator I = TypeNames.find(Ty);
  if (I != TypeNames.end())
    return I->second + " " + NameSoFar + VariableName;
  
  // Check to see if the Type is already on the stack...
  unsigned Slot = 0, CurSize = TypeStack.size();
  while (Slot < CurSize && TypeStack[Slot] != Ty) ++Slot; // Scan for type

  if (Slot < CurSize)
    return "\\" + utostr(CurSize-Slot) + " " + NameSoFar + VariableName;  
  // Here's the upreference

  TypeStack.push_back(Ty);    // Recursive case: Add us to the stack..
  
  string Result;
  string tempstr = "";

  switch (Ty->getPrimitiveID()) {
  case Type::FunctionTyID: {
    string MInfo = "";
    const FunctionType *MTy = cast<const FunctionType>(Ty);
    Result += calcTypeName(MTy->getReturnType(), TypeStack, TypeNames, &MInfo);
    if (MInfo != "")
      Result += ") " + MInfo;
    Result += " " + NameSoFar + VariableName;
    Result += " (";
    for (FunctionType::ParamTypes::const_iterator
           I = MTy->getParamTypes().begin(),
           E = MTy->getParamTypes().end(); I != E; ++I) {
      if (I != MTy->getParamTypes().begin())
        Result += ", ";
      MInfo = "";
      Result += calcTypeName(*I, TypeStack, TypeNames, &MInfo);
      if (MInfo != "")
	Result += ") " + MInfo;
    }
    if (MTy->isVarArg()) {
      if (!MTy->getParamTypes().empty()) 
	Result += ", ";
      Result += "...";
    }
    Result += ")";
    break;
  }
  case Type::StructTyID: {
    const StructType *STy = cast<const StructType>(Ty);
    Result = " struct {\n ";
    int indx = 0;
    for (StructType::ElementTypes::const_iterator
           I = STy->getElementTypes().begin(),
           E = STy->getElementTypes().end(); I != E; ++I) {
      Result += calcTypeNameVar(*I, TypeStack, TypeNames, 
				"field" + itostr(indx++), "");
      Result += ";\n ";
    }
    Result += " }";
    Result += " " + NameSoFar + VariableName;
    break;
  }  

  case Type::PointerTyID: {
    Result = calcTypeNameVar(cast<const PointerType>(Ty)->getElementType(), 
			     TypeStack, TypeNames, tempstr, 
			     "(*" + NameSoFar + VariableName + ")");
    break;
  }
  
  case Type::ArrayTyID: {
    const ArrayType *ATy = cast<const ArrayType>(Ty);
    int NumElements = ATy->getNumElements();
    Result = calcTypeNameVar(ATy->getElementType(), TypeStack, TypeNames, 
			     tempstr, NameSoFar + VariableName + "[" + 
			     itostr(NumElements) + "]");
    break;
  }
  default:
    assert(0 && "Unhandled case in getTypeProps!");
    Result = "<error>";
  }

  TypeStack.pop_back();       // Remove self from stack...
  return Result;
}

// printTypeVarInt - The internal guts of printing out a type that has a
// potentially named portion and the variable associated with the type.
static ostream &printTypeVarInt(ostream &Out, const Type *Ty,
                             map<const Type *, string> &TypeNames,
			     string VariableName) {
  // Primitive types always print out their description, regardless of whether
  // they have been named or not.
  
  // Booleans have to be specially handled to be printed as ints with values 
  // 0 or 1;
  if (Ty->isPrimitiveType())
    switch (Ty->getPrimitiveID()) {
    case Type::BoolTyID: 
      return Out << "int " << VariableName;
      break;
    case Type::UByteTyID:
      return Out << "unsigned char " << VariableName;
      break;
    case Type::SByteTyID:
      return Out << "signed char " << VariableName;
      break;
    case Type::UShortTyID:
      return Out << "unsigned long long " << VariableName;
      break;
    case Type::ULongTyID:
      return Out << "unsigned long long " << VariableName;
      break;
    case Type::LongTyID:
      return Out << "signed long long " << VariableName;
      break;
    case Type::UIntTyID:
      return Out << "unsigned int " << VariableName;
      break;
    default :
      return Out << Ty->getDescription() << " " << VariableName; 
    }
  
  // Check to see if the type is named.
  map<const Type *, string>::iterator I = TypeNames.find(Ty);
  if (I != TypeNames.end()) return Out << I->second << " " << VariableName;
  
  // Otherwise we have a type that has not been named but is a derived type.
  // Carefully recurse the type hierarchy to print out any contained symbolic
  // names.
  //
  vector<const Type *> TypeStack;
  string TypeNameVar, tempstr = "";
  TypeNameVar = calcTypeNameVar(Ty, TypeStack, TypeNames, VariableName, 
				tempstr);
  return Out << TypeNameVar;
  // TODO: Check what happens to caching
  // TypeNames.insert(std::make_pair(Ty, TypeName));
  //Cache type name for later use
}

// Internal guts of printing a type name
static ostream &printTypeInt(ostream &Out, const Type *Ty,
                             map<const Type *, string> &TypeNames) {
  // Primitive types always print out their description, regardless of whether
  // they have been named or not.
  
  // Booleans have to be specially handled to be printed as ints with values 
  // 0 or 1;
 
  if (Ty->isPrimitiveType())
    switch (Ty->getPrimitiveID()) {
    case Type::BoolTyID:
      return Out << "int";
      break;
    case Type::UByteTyID:
      return Out << "unsigned char";
      break;
    case Type::SByteTyID:
      return Out << "signed char";
      break;
    case Type::UShortTyID:
      return Out << "unsigned long long";
      break;
    case Type::ULongTyID:
      return Out << "unsigned long long";
      break;
    case Type::LongTyID:
      return Out << "signed long long";
      break;
    case Type::UIntTyID:
      return Out << "unsigned int";
      break;
    default :
      return Out << Ty->getDescription(); 
    }
  
  // Check to see if the type is named.
  map<const Type *, string>::iterator I = TypeNames.find(Ty);
  if (I != TypeNames.end()) return Out << I->second;
  
  // Otherwise we have a type that has not been named but is a derived type.
  // Carefully recurse the type hierarchy to print out any contained symbolic
  // names.
  //
  vector<const Type *> TypeStack;
  string MInfo = "";
  string TypeName = calcTypeName(Ty, TypeStack, TypeNames, &MInfo);
  // TypeNames.insert(std::make_pair(Ty, TypeName));
  //Cache type name for later use
  if (MInfo != "")
    return Out << TypeName << ")" << MInfo;
  else
    return Out << TypeName;
}

namespace {

  //Internal CWriter class mimics AssemblyWriter.
  class CWriter {
    ostream& Out; 
    SlotCalculator &Table;
    const Module *TheModule;
    map<const Type *, string> TypeNames;
  public:
    inline CWriter(ostream &o, SlotCalculator &Tab, const Module *M)
      : Out(o), Table(Tab), TheModule(M) {
      
    }
    
    inline void write(const Module *M)         { printModule(M);      }

    ostream& printTypeVar(const Type *Ty, string VariableName, ostream &Out);
    ostream& printType(const Type *Ty, ostream &Out);
    void writeOperand(const Value *Operand, bool PrintType,ostream &Out, 
		      bool PrintName = true);

  private :
    void printModule(const Module *M);
    void printSymbolTable(const SymbolTable &ST);
    void printConstant(const Constant *CPV);
    void printGlobal(const GlobalVariable *GV);
    void printFunctionDecl(const Function *M); //for printing just the method 
                                               // declaration
    void printFunctionArgument(const Argument *MA);
    
    void printFunction(const Function *);
    
    void outputFunction(const Function *, CLocalVars &);  
    void outputBasicBlock(const BasicBlock *);
  };
  /* END class CWriter */


  /* CLASS InstLocalVarsVisitor */
  class InstLocalVarsVisitor : public InstVisitor<InstLocalVarsVisitor> {
    SlotCalculator& Table;
  
    void handleTerminator(TerminatorInst *tI,int indx);
    
  public:
    CLocalVars CLV;
    
    InstLocalVarsVisitor(SlotCalculator& table) : Table(table) {
      
    }
    
    void visitInstruction(Instruction *I) {
      string tempostr;
      if (I && I->hasName() && !isa<PHINode>(I)) {
	tempostr = "llvm__" + makeNameProper(I->getName()) + "_" +
	  itostr((int)I->getType()->getUniqueID());
	CLV.addLocalVar(I->getType(), tempostr);
      } else  if (I) {
	int Slot = Table.getValSlot(I);
	//if (Slot < 0) then  it is a instruction with no 
	// value (like return void )
	if ((Slot >= 0) && !isa<PHINode>(I)) {
	  tempostr = "llvm__tmp_";
	  tempostr += itostr(Slot) + "_" + 
	    itostr((int)I->getType()->getUniqueID());
	  CLV.addLocalVar(I->getType(), tempostr);
	}
      }
      
    }

    void visitBranchInst(BranchInst *I) {
      TerminatorInst *tI = cast<TerminatorInst>(I);
      if (I->getNumOperands() > 1) {
	handleTerminator(tI, 0);
	handleTerminator(tI, 1);
      }
      else {
	handleTerminator(tI, 0);
      } 
    }
    
  };
  

  /* CLASS CInstPrintVisitor */

  class CInstPrintVisitor: public InstVisitor<CInstPrintVisitor> {
    CWriter& CW;
    SlotCalculator& Table;
    ostream &Out;
    const Value *Operand;

    void outputLValue(Instruction *);
    void printPhiFromNextBlock(TerminatorInst *tI, int indx);

  public:
    CInstPrintVisitor (CWriter &cw, SlotCalculator& table, ostream& o) 
      : CW(cw), Table(table), Out(o) {
      
    }
    
    void visitCastInst(CastInst *I);
    void visitCallInst(CallInst *I);
    void visitShr(ShiftInst *I);
    void visitShl(ShiftInst *I);
    void visitReturnInst(ReturnInst *I);
    void visitBranchInst(BranchInst *I);
    void visitSwitchInst(SwitchInst *I);
    void visitInvokeInst(InvokeInst *I) ;
    void visitMallocInst(MallocInst *I);
    void visitAllocaInst(AllocaInst *I);
    void visitFreeInst(FreeInst   *I);
    void visitLoadInst(LoadInst   *I);
    void visitStoreInst(StoreInst  *I);
    void visitGetElementPtrInst(GetElementPtrInst *I);
    void visitPHINode(PHINode *I);
    void visitUnaryOperator (UnaryOperator *I);
    void visitBinaryOperator(BinaryOperator *I);

  };
  
}

void InstLocalVarsVisitor::handleTerminator(TerminatorInst *tI,int indx) {
  BasicBlock *bb = tI->getSuccessor(indx);
  BasicBlock::const_iterator insIt = bb->begin();
  while (insIt != bb->end()) {
    if (const PHINode *pI = dyn_cast<const PHINode>(*insIt)) {
      //Its a phinode!
      //Calculate the incoming index for this
      int incindex = pI->getBasicBlockIndex(tI->getParent());
      if (incindex != -1)
	if (pI && pI->hasName()) {
	  string tempostr;
	  tempostr = "llvm__" + makeNameProper(pI->getName()) + "_" + 
	    itostr((int)pI->getType()->getUniqueID());
	  CLV.addLocalVar(pI->getType(), tempostr) ;
	} else {
	  string tempostr;
	  int Slot = Table.getValSlot(pI);
	  if (Slot >= 0) {
	    tempostr = "llvm__tmp_" + itostr(Slot) + "_" 
	      + itostr((int)pI->getType()->getUniqueID());
	    CLV.addLocalVar(pI->getType(), tempostr);
	  }
	}
      
    }
    else break;
    insIt++;
  }
}

/* Implementation of CInstPrintVisitor */

void CInstPrintVisitor::outputLValue(Instruction *I) {
  if (I && I->hasName() && !isa<PHINode>(I)) {
    Out << "llvm__" << makeNameProper(I->getName()) << "_" 
	 << I->getType()->getUniqueID() << " = ";
  } else {
    int Slot = Table.getValSlot(I);
    //if (Slot < 0) then  it is a instruction with no value (like return void )
    if ((Slot >= 0) && !isa<PHINode>(I))
      Out << "llvm__tmp_" << Slot << "_" << I->getType()->getUniqueID() 
	  << " = ";
  }
}

void CInstPrintVisitor::printPhiFromNextBlock(TerminatorInst *tI, int indx) {
  BasicBlock *bb = tI->getSuccessor(indx);
  BasicBlock::const_iterator insIt = bb->begin();
  while (insIt != bb->end()) {
    if (const PHINode *pI = dyn_cast<const PHINode>(*insIt)) {
      //Its a phinode!
      //Calculate the incoming index for this
      int incindex = pI->getBasicBlockIndex(tI->getParent());
      if (incindex != -1)
	{
	  //now we have to do the printing
	  if (pI && pI->hasName()) {
	    Out << "llvm__" << makeNameProper(pI->getName()) << "_" 
		<< pI->getType()->getUniqueID() << " = ";
	  } else {
	    int Slot = Table.getValSlot(pI);
	    if (Slot >= 0) 
	      Out << "llvm__tmp_" << Slot << "_" 
		  << pI->getType()->getUniqueID() << " = ";
	  }
	  CW.writeOperand(pI->getIncomingValue(incindex),false, Out);
	  Out << ";\n";
	}
    }
    else break;
    insIt++;
  }
}

// Implement all "other" instructions, except for PHINode
void CInstPrintVisitor::visitCastInst(CastInst *I) {
  outputLValue(I);
  Operand = I->getNumOperands() ? I->getOperand(0) : 0;
  Out << "(";
  CW.printType(I->getType(), Out);
  Out << ")";
  CW.writeOperand(Operand, false, Out);
  Out << ";\n";
}

void CInstPrintVisitor::visitCallInst(CallInst *I) {
  outputLValue(I);
  Operand = I->getNumOperands() ? I->getOperand(0) : 0;
  const PointerType *PTy = dyn_cast<PointerType>(Operand->getType());
  const FunctionType  *MTy = PTy 
    ? dyn_cast<FunctionType>(PTy->getElementType()):0;
  const Type      *RetTy = MTy ? MTy->getReturnType() : 0;
  
  // If possible, print out the short form of the call instruction, but we can
  // only do this if the first argument is a pointer to a nonvararg method,
  // and if the value returned is not a pointer to a method.
  //
  if (RetTy && !MTy->isVarArg() &&
      (!isa<PointerType>(RetTy)||
       !isa<FunctionType>(cast<PointerType>(RetTy)))){
    Out << " ";
    Out << makeNameProper(Operand->getName());
  } else {
    Out << makeNameProper(Operand->getName());      
  }
  Out << "(";
  if (I->getNumOperands() > 1) 
    CW.writeOperand(I->getOperand(1), false, Out);
  for (unsigned op = 2, Eop = I->getNumOperands(); op < Eop; ++op) {
    Out << ",";
    CW.writeOperand(I->getOperand(op), false, Out);
  }
  
  Out << " );\n";
} 
 
void CInstPrintVisitor::visitShr(ShiftInst *I) {
  outputLValue(I);
  Operand = I->getNumOperands() ? I->getOperand(0) : 0;
  Out << "(";
  CW.writeOperand(Operand, false, Out);
  Out << " >> ";
  Out << "(";
  CW.writeOperand(I->getOperand(1), false, Out);
  Out << "));\n";
}

void CInstPrintVisitor::visitShl(ShiftInst *I) {
  outputLValue(I);
  Operand = I->getNumOperands() ? I->getOperand(0) : 0;
  Out << "(";
  CW.writeOperand(Operand, false, Out);
  Out << " << ";
  Out << "(";
  CW.writeOperand(I->getOperand(1), false, Out);
  Out << "));\n";
}

// Specific Instruction type classes... note that all of the casts are
// neccesary because we use the instruction classes as opaque types...
//
void CInstPrintVisitor::visitReturnInst(ReturnInst *I) {
  Operand = I->getNumOperands() ? I->getOperand(0) : 0;
  Out << "return ";
  if (Operand) 
    CW.writeOperand(Operand,false, Out);
  Out << ";\n";
}

void CInstPrintVisitor::visitBranchInst(BranchInst *I) {
  Operand = I->getNumOperands() ? I->getOperand(0) : 0;
  TerminatorInst *tI = cast<TerminatorInst>(I);
  if (I->getNumOperands() > 1) {
    Out << "if (";
    CW.writeOperand(I->getOperand(2),false, Out);
    Out << ")  {\n";
    printPhiFromNextBlock(tI,0);
    Out << "  goto ";
    CW.writeOperand(Operand,false, Out);
    Out << ";\n";
    Out << "}" << "else {\n";
    printPhiFromNextBlock(tI,1);
    Out << "  goto ";
    CW.writeOperand(I->getOperand(1),false, Out);
    Out << ";\n";
    Out << "}\n";
  } else {
    printPhiFromNextBlock(tI,0);
    Out << "  goto ";
    CW.writeOperand(Operand, false, Out);
    Out << ";\n";
  }
  Out << "\n";
}

void CInstPrintVisitor::visitSwitchInst(SwitchInst *I) {
  Out << "\n";
}

void CInstPrintVisitor::visitInvokeInst(InvokeInst *I) {
  Out << "\n";
}

void CInstPrintVisitor::visitMallocInst(MallocInst *I) {
  outputLValue(I);
  Operand = I->getNumOperands() ? I->getOperand(0) : 0;
  string tempstr = "";
  Out << "(";
  CW.printType(cast<const PointerType>(I->getType())->getElementType(), Out);
  Out << "*) malloc(sizeof(";
  CW.printTypeVar(cast<const PointerType>(I->getType())->getElementType(), 
	       tempstr, Out);
  Out << ")";
  if (I->getNumOperands()) {
    Out << " * " ;
    CW.writeOperand(Operand, false, Out);
  }
  Out << ");";
}

void CInstPrintVisitor::visitAllocaInst(AllocaInst *I) {
  outputLValue(I);
  Operand = I->getNumOperands() ? I->getOperand(0) : 0;
  string tempstr = "";
  Out << "(";
  CW.printTypeVar(I->getType(), tempstr, Out);
  Out << ") alloca(sizeof(";
  CW.printTypeVar(cast<const PointerType>(I->getType())->getElementType(), 
	       tempstr, Out);
  Out << ")";
  if (I->getNumOperands()) {
    Out << " * " ;
    CW.writeOperand(Operand, false, Out);
  }
  Out << ");\n";
}

void CInstPrintVisitor::visitFreeInst(FreeInst   *I) {
  Operand = I->getNumOperands() ? I->getOperand(0) : 0;
  Out << "free(";
  CW.writeOperand(Operand, false, Out);
  Out << ");\n";
}

void CInstPrintVisitor::visitLoadInst(LoadInst   *I) {
  outputLValue(I);
  Operand = I->getNumOperands() ? I->getOperand(0) : 0;
  if (I->getNumOperands() <= 1) {
    Out << "*";
    CW.writeOperand(Operand,false, Out);     
  }
  else {
    //Check if it is an array type or struct type ptr!
    int arrtype = 1;
    const PointerType *PTy = dyn_cast<PointerType>(I->getType());
    if (cast<const PointerType>(Operand->getType())->getElementType()->getPrimitiveID() == Type::StructTyID)
      arrtype = 0;
    if (arrtype && isa<GlobalValue>(Operand))
      Out << "(&";
    CW.writeOperand(Operand,false, Out);
    for (unsigned i = 1, E = I->getNumOperands(); i != E; ++i) {
      if (i == 1) {
	if (arrtype || !isa<GlobalValue>(Operand)) {
	  Out << "[";
	  CW.writeOperand(I->getOperand(i), false, Out);
	  Out << "]";
	}
	if (isa<GlobalValue>(Operand) && arrtype)
	  Out << ")";
      }
      else {
	if (arrtype == 1) Out << "[";
	else 
	  Out << ".field";
	CW.writeOperand(I->getOperand(i), false, Out);
	if (arrtype == 1) Out << "]";
      }
    }
  }
  Out << ";\n";
}

void CInstPrintVisitor::visitStoreInst(StoreInst  *I) {
  Operand = I->getNumOperands() ? I->getOperand(0) : 0;
  if (I->getNumOperands() <= 2) {
    Out << "*";
    CW.writeOperand(I->getOperand(1), false, Out);
  }
  else {
    //Check if it is an array type or struct type ptr!
    int arrtype = 1;
    if (cast<const PointerType>(I->getOperand(1)->getType())->getElementType()->getPrimitiveID() == Type::StructTyID) 
      arrtype = 0;
    if (isa<GlobalValue>(I->getOperand(1)) && arrtype)
      Out << "(&";
    CW.writeOperand(I->getOperand(1), false, Out);
    for (unsigned i = 2, E = I->getNumOperands(); i != E; ++i) {
      if (i == 2) {
	if (arrtype || !isa<GlobalValue>(I->getOperand(1))) {
	  Out << "[";
	  CW.writeOperand(I->getOperand(i), false, Out);
	  Out << "]";
	}
	if (isa<GlobalValue>(I->getOperand(1)) && arrtype)
	  Out << ")";
      }
      else {
	if (arrtype == 1) Out << "[";
	else 
	  Out << ".field";
	CW.writeOperand(I->getOperand(i), false, Out);
	if (arrtype == 1) Out << "]";
      }
    }
  }
  Out << " = ";
  CW.writeOperand(Operand,false, Out);
  Out << ";\n";
}

void CInstPrintVisitor::visitGetElementPtrInst(GetElementPtrInst *I) {
  outputLValue(I);
  Operand = I->getNumOperands() ? I->getOperand(0) : 0;
  Out << " &(";
  if (I->getNumOperands() <= 1)
    CW.writeOperand(Operand,false, Out);
  else {
    //Check if it is an array type or struct type ptr!
    int arrtype = 1;
    if ((cast<const PointerType>(Operand->getType()))->getElementType()->getPrimitiveID() == Type::StructTyID) 
      arrtype = 0;
    if ((isa<GlobalValue>(Operand)) && arrtype)
      Out << "(&";    
    CW.writeOperand(Operand,false, Out);
    for (unsigned i = 1, E = I->getNumOperands(); i != E; ++i) {
      if (i == 1) {
	if (arrtype || !isa<GlobalValue>(Operand)){
	  Out << "[";
	  CW.writeOperand(I->getOperand(i), false, Out);
	  Out << "]";
	}
	if (isa<GlobalValue>(Operand) && arrtype)
	  Out << ")";
      }
      else {
	if (arrtype == 1) Out << "[";
	else 
	  Out << ".field";
	CW.writeOperand(I->getOperand(i), false, Out);
	if (arrtype == 1) Out << "]";
      }
    }
  }
  Out << ");\n";
}

void CInstPrintVisitor::visitPHINode(PHINode *I) {
  
}

void CInstPrintVisitor::visitUnaryOperator (UnaryOperator *I) {
  if (I->getOpcode() == Instruction::Not) { 
    outputLValue(I);
    Operand = I->getNumOperands() ? I->getOperand(0) : 0;
    Out << "!(";
    CW.writeOperand(Operand,false, Out);
    Out << ");\n";
  }
  else {
    Out << "<bad unary inst>\n";
  }
}

void CInstPrintVisitor::visitBinaryOperator(BinaryOperator *I) {
  //binary instructions, shift instructions, setCond instructions.
  outputLValue(I);
  Operand = I->getNumOperands() ? I->getOperand(0) : 0;
  if (I->getType()->getPrimitiveID() == Type::PointerTyID) {
    Out << "(";
    CW.printType(I->getType(), Out);
    Out << ")";
  }
  Out << "(";
  if (Operand->getType()->getPrimitiveID() == Type::PointerTyID)
    Out << "(long long)";
  CW.writeOperand(Operand,false, Out);
  Out << getOpcodeOperName(I);
  // Need the extra parenthisis if the second operand is < 0
  Out << '(';
  if (I->getOperand(1)->getType()->getPrimitiveID() == Type::PointerTyID)
    Out << "(long long)";
  CW.writeOperand(I->getOperand(1),false, Out);
  Out << ')';
  Out << ");\n";
}

/* END : CInstPrintVisitor implementation */

void CWriter::printModule(const Module *M) {
  // printing stdlib inclusion
  // Out << "#include <stdlib.h>\n";

  // Loop over the symbol table, emitting all named constants...
  if (M->hasSymbolTable())
    printSymbolTable(*M->getSymbolTable());

  for_each(M->gbegin(), M->gend(), 
	   bind_obj(this, &CWriter::printGlobal));

  // First output all the declarations of the methods as C requires Functions 
  // be declared before they are used.
  for_each(M->begin(), M->end(), bind_obj(this,&CWriter::printFunctionDecl));
  
  // declaration of alloca
  Out << "void *alloca(unsigned long size);\n";
  
  // Output all of the methods...
  for_each(M->begin(), M->end(), bind_obj(this,&CWriter::printFunction));
}

// prints the global constants
void CWriter::printGlobal(const GlobalVariable *GV) {
  string tempostr;
  if (GV->hasName()) 
    tempostr = "llvm__" + makeNameProper(GV->getName()) + "_" + 
      itostr((int)GV->getType()->getUniqueID());
  if (GV->hasInternalLinkage()) Out << "static ";

  printTypeVar(GV->getType()->getElementType(), tempostr, Out);

  if (GV->hasInitializer()) {
    Out << " = " ;
    writeOperand(GV->getInitializer(), false, Out, false);
  }

  Out << ";\n";
}

// printSymbolTable - Run through symbol table looking for named constants
// if a named constant is found, emit it's declaration...
// Assuming that symbol table has only types and constants.
void CWriter::printSymbolTable(const SymbolTable &ST) {
  // GraphT G;
  for (SymbolTable::const_iterator TI = ST.begin(); TI != ST.end(); ++TI) {
    SymbolTable::type_const_iterator I = ST.type_begin(TI->first);
    SymbolTable::type_const_iterator End = ST.type_end(TI->first);
    
    // TODO
    // Need to run through all the used types in the program
    // FindUsedTypes &FUT = new FindUsedTypes();
    // const std::set<const Type *> &UsedTypes = FUT.getTypes();
    // Filter out the structures printing forward definitions for each of them
    // and creating the dependency graph.
    // Print forward definitions to all of them
    // print the typedefs topologically sorted

    // But for now we have
    for (; I != End; ++I) {
      const Value *V = I->second;
      if (const Constant *CPV = dyn_cast<const Constant>(V)) {
	printConstant(CPV);
      } else if (const Type *Ty = dyn_cast<const Type>(V)) {
	string tempostr;
	string tempstr = "";
	Out << "typedef ";
	vector<const Type *> TypeStack;
	tempostr = "llvm__" + I->first;
	string TypeNameVar = calcTypeNameVar(Ty, TypeStack, TypeNames, 
					     tempostr, tempstr);
	Out << TypeNameVar << ";\n";
	if (!isa<PointerType>(Ty) ||
	    !cast<PointerType>(Ty)->getElementType()->isPrimitiveType())
	  TypeNames.insert(std::make_pair(Ty, "llvm__"+I->first));
      }
    }
  }
}


// printConstant - Print out a constant pool entry...
//
void CWriter::printConstant(const Constant *CPV) {
  // TODO
  // Dinakar : Don't know what to do with unnamed constants
  // should do something about it later.

  string tempostr;
  if (CPV->hasName()) {
    // Print out name...
    tempostr = "llvm__" + makeNameProper(CPV->getName()) + "_" + 
      itostr((int)CPV->getType()->getUniqueID());
  } else {
    int Slot = Table.getValSlot(CPV); // slot number 
    if (Slot >= 0)  
      tempostr = "llvm__tmp_" + itostr(Slot) + "_" + 
	itostr((int)CPV->getType()->getUniqueID());
    else 
      tempostr = "<badref>";
  }
  
  // Print out the constant type...
  printTypeVar(CPV->getType(), tempostr, Out);
  
  Out << " = ";
  // Write the value out now...
  writeOperand(CPV, false, Out, false);
  
  Out << "\n";
}



// printFunctionDecl - Print method declaration
//
void CWriter::printFunctionDecl(const Function *M) {
  
  if (M->hasInternalLinkage()) Out <<"static ";
  
  // Loop over the arguments, printing them...
  const FunctionType *MT = cast<const FunctionType>(M->getFunctionType());
  
  if (!M->isExternal()) {
    // Print out the return type and name...
    printType(M->getReturnType(), Out);
    Out << " " << makeNameProper(M->getName()) << "(";
    
    for_each(M->getArgumentList().begin(), M->getArgumentList().end(),
	     bind_obj(this, &CWriter::printFunctionArgument));
  } else {
      // Print out the return type and name...
    printType(M->getReturnType(), Out) ;
    Out << " " << makeNameProper(M->getName()) << "(";
    
    // Loop over the arguments, printing them...
    const FunctionType *MT = cast<const FunctionType>(M->getFunctionType());
    for (FunctionType::ParamTypes::const_iterator I = 
	   MT->getParamTypes().begin(),
	   E = MT->getParamTypes().end(); I != E; ++I) {
      if (I != MT->getParamTypes().begin()) Out << ", ";
      printType(*I, Out);
    }
  }

  // Finish printing arguments...
  if (MT->isVarArg()) {
    if (MT->getParamTypes().size()) Out << ", ";
    Out << "...";  // Output varargs portion of signature!
  }
  Out << ");\n";
}

void CWriter::printFunction(const Function *M) {
  if (!M->isExternal()) {
    // Process each of the basic blocks, gather information and call the  
    // output methods on the CLocalVars and Function* objects.
    
    // gather local variable information for each basic block
    InstLocalVarsVisitor ILV(Table);
    ILV.visit((Function *)M);
 
    // Spout out code. 
    outputFunction(M, ILV.CLV);
    
  }
}

// printFunctionArgument - This member is called for every argument that 
// is passed into the method.  Simply print it out
//
void CWriter::printFunctionArgument(const Argument *Arg) {
  // Insert commas as we go... the first arg doesn't get a comma
  string tempostr;
  if (Arg != Arg->getParent()->getArgumentList().front()) Out << ", ";
  
  // Output name, if available...
  if (Arg->hasName()) {
    tempostr = "llvm__" + makeNameProper(Arg->getName()) + "_" + 
      itostr((int)Arg->getType()->getUniqueID());
  } else if (Table.getValSlot(Arg) < 0) {
    tempostr = "<badref>";
  }
  else {
    tempostr = "llvm__tmp_" + itostr(Table.getValSlot(Arg)) + "_" +
      itostr((int)Arg->getType()->getUniqueID());
  }
  // Output type...
  // printType(Arg->getType(), Out);
  // Out << " " << tempostr;
  printTypeVar (Arg->getType(), tempostr, Out);
}

void CWriter::outputFunction(const Function *M, CLocalVars& CLV) {
  // Currently we have a no-loop-structure implementation
  // Seems like its not really necessary.

  // Print out the return type and name...
  printType(M->getReturnType(), Out) ;
  Out << " " << makeNameProper(M->getName()) << "(";
  // Loop over the arguments, printing them...
  const FunctionType *MT = cast<const FunctionType>(M->getFunctionType());
  
  if (!M->isExternal()) {
    for_each(M->getArgumentList().begin(), M->getArgumentList().end(),
	     bind_obj(this, &CWriter::printFunctionArgument));
  } else {
    // Loop over the arguments, printing them...
    const FunctionType *MT = cast<const FunctionType>(M->getFunctionType());
    for (FunctionType::ParamTypes::const_iterator I = 
	   MT->getParamTypes().begin(),
	   E = MT->getParamTypes().end(); I != E; ++I) {
      if (I != MT->getParamTypes().begin()) Out << ", ";
      printType(*I, Out);
    }
  }
  
  // Finish printing arguments...
  if (MT->isVarArg()) {
    if (MT->getParamTypes().size()) Out << ", ";
    Out << "...";  // Output varargs portion of signature!
  }
  Out << ")\n";
  
  if (!M->isExternal()) {
    Out << "{\n";
    // Loop over the symbol table, emitting all named constants...
    if (M->hasSymbolTable())
      printSymbolTable(*M->getSymbolTable()); 
    
    // print the local variables
    // we assume that every local variable is alloca'ed in the C code.
    std::map<const Type*, VarListType> locals;
    locals = CLV.LocalVars;
    
    map<const Type*, VarListType>::iterator iter;
    for (iter = locals.begin(); iter != locals.end(); iter++) {
      VarListType::iterator listiter;
      for (listiter = iter->second.begin(); listiter != iter->second.end(); 
	   listiter++) {
	// printType(iter->first, Out);
	// Out << " " << *listiter << ";\n";
	printTypeVar(iter->first, *listiter, Out);
	Out << ";\n";
      }
    }
    
    // print the basic blocks
    Function::const_iterator iterBB;
    for (iterBB = M->begin(); iterBB != M->end(); ++iterBB)
      outputBasicBlock(*iterBB); 
    
    Out << "}\n";
  }
}

void CWriter::outputBasicBlock(const BasicBlock* BB) {

  if (BB->hasName()) {              // Print out the label if it exists...
    Out << "llvm__" << makeNameProper(BB->getName()) << "_" 
	<< BB->getType()->getUniqueID() << ":\n";
  } else {
    int Slot = Table.getValSlot(BB);
    Out << "llvm__tmp_";
    if (Slot >= 0) 
      Out << Slot << "_" << BB->getType()->getUniqueID() << ":\n";         
    // Extra newline seperates out label's
    else 
      Out << "<badref>\n"; 
  }

  // Output all of the instructions in the basic block...
  // print the basic blocks
  CInstPrintVisitor CIPV(*this, Table, Out);
  CIPV.visit((BasicBlock *) BB);
}

// printTypeVar - Go to extreme measures to attempt to print out a short, 
// symbolic version of a type name.
//
ostream& CWriter::printTypeVar(const Type *Ty, string VariableName, 
		      ostream &Out) {
  return printTypeVarInt(Out, Ty, TypeNames, VariableName);
}

// printType - Go to extreme measures to attempt to print out a short, symbolic
// version of a type name.
ostream& CWriter::printType(const Type *Ty, ostream &Out) {
  return printTypeInt(Out, Ty, TypeNames);
}


void CWriter::writeOperand(const Value *Operand, bool PrintType, 
				  ostream &Out, bool PrintName = true) {
  if (PrintType){ 
    string tempstr = "";
    Out << " "; 
    printType(Operand->getType(), Out); 
  }
  vector<const Type *> TypeStack;
  string MInfo = "";
  string OperandType = calcTypeName(Operand->getType(), TypeStack, TypeNames, 
				    &MInfo);
  if (MInfo != "")
    OperandType += ")" + MInfo;
  WriteCOperandInternal(Out, Operand, PrintName, &Table, OperandType);
}


//===----------------------------------------------------------------------===//
//                       External Interface declaration
//===----------------------------------------------------------------------===//


void WriteToC(const Module *C, ostream &Out) {
  assert(C && "You can't write a null module!!");
  SlotCalculator SlotTable(C, true);
  CWriter W(Out, SlotTable, C);
  W.write(C);
  Out.flush();
}