MachineDebugInfo.cpp

//===-- llvm/CodeGen/MachineDebugInfo.cpp -----------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file was developed by James M. Laskey and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "llvm/CodeGen/MachineDebugInfo.h"

#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/GlobalVariable.h"
#include "llvm/Intrinsics.h"
#include "llvm/Instructions.h"
#include "llvm/Module.h"
#include "llvm/Support/Dwarf.h"

#include <iostream>

using namespace llvm;
using namespace llvm::dwarf;

// Handle the Pass registration stuff necessary to use TargetData's.
namespace {
  RegisterPass<MachineDebugInfo> X("machinedebuginfo", "Debug Information");
}

//===----------------------------------------------------------------------===//

/// getGlobalVariablesUsing - Return all of the GlobalVariables which have the
/// specified value in their initializer somewhere.
static void
getGlobalVariablesUsing(Value *V, std::vector<GlobalVariable*> &Result) {
  // Scan though value users.
  for (Value::use_iterator I = V->use_begin(), E = V->use_end(); I != E; ++I) {
    if (GlobalVariable *GV = dyn_cast<GlobalVariable>(*I)) {
      // If the user is a GlobalVariable then add to result.
      Result.push_back(GV);
    } else if (Constant *C = dyn_cast<Constant>(*I)) {
      // If the user is a constant variable then scan its users
      getGlobalVariablesUsing(C, Result);
    }
  }
}

/// getGlobalVariablesUsing - Return all of the GlobalVariables that use the
/// named GlobalVariable.
static std::vector<GlobalVariable*>
getGlobalVariablesUsing(Module &M, const std::string &RootName) {
  std::vector<GlobalVariable*> Result;  // GlobalVariables matching criteria.
  
  std::vector<const Type*> FieldTypes;
  FieldTypes.push_back(Type::UIntTy);
  FieldTypes.push_back(PointerType::get(Type::SByteTy));

  // Get the GlobalVariable root.
  GlobalVariable *UseRoot = M.getGlobalVariable(RootName,
                                                StructType::get(FieldTypes));

  // If present and linkonce then scan for users.
  if (UseRoot && UseRoot->hasLinkOnceLinkage()) {
    getGlobalVariablesUsing(UseRoot, Result);
  }
  
  return Result;
}
  
/// getStringValue - Turn an LLVM constant pointer that eventually points to a
/// global into a string value.  Return an empty string if we can't do it.
///
static const std::string getStringValue(Value *V, unsigned Offset = 0) {
  if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V)) {
    if (GV->hasInitializer() && isa<ConstantArray>(GV->getInitializer())) {
      ConstantArray *Init = cast<ConstantArray>(GV->getInitializer());
      if (Init->isString()) {
        std::string Result = Init->getAsString();
        if (Offset < Result.size()) {
          // If we are pointing INTO The string, erase the beginning...
          Result.erase(Result.begin(), Result.begin()+Offset);

          // Take off the null terminator, and any string fragments after it.
          std::string::size_type NullPos = Result.find_first_of((char)0);
          if (NullPos != std::string::npos)
            Result.erase(Result.begin()+NullPos, Result.end());
          return Result;
        }
      }
    }
  } else if (Constant *C = dyn_cast<Constant>(V)) {
    if (GlobalValue *GV = dyn_cast<GlobalValue>(C))
      return getStringValue(GV, Offset);
    else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
      if (CE->getOpcode() == Instruction::GetElementPtr) {
        // Turn a gep into the specified offset.
        if (CE->getNumOperands() == 3 &&
            cast<Constant>(CE->getOperand(1))->isNullValue() &&
            isa<ConstantInt>(CE->getOperand(2))) {
          return getStringValue(CE->getOperand(0),
                   Offset+cast<ConstantInt>(CE->getOperand(2))->getRawValue());
        }
      }
    }
  }
  return "";
}

/// isStringValue - Return true if the given value can be coerced to a string.
///
static bool isStringValue(Value *V) {
  if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V)) {
    if (GV->hasInitializer() && isa<ConstantArray>(GV->getInitializer())) {
      ConstantArray *Init = cast<ConstantArray>(GV->getInitializer());
      return Init->isString();
    }
  } else if (Constant *C = dyn_cast<Constant>(V)) {
    if (GlobalValue *GV = dyn_cast<GlobalValue>(C))
      return isStringValue(GV);
    else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
      if (CE->getOpcode() == Instruction::GetElementPtr) {
        if (CE->getNumOperands() == 3 &&
            cast<Constant>(CE->getOperand(1))->isNullValue() &&
            isa<ConstantInt>(CE->getOperand(2))) {
          return isStringValue(CE->getOperand(0));
        }
      }
    }
  }
  return false;
}

/// getGlobalVariable - Return either a direct or cast Global value.
///
static GlobalVariable *getGlobalVariable(Value *V) {
  if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V)) {
    return GV;
  } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
    if (CE->getOpcode() == Instruction::Cast) {
      return dyn_cast<GlobalVariable>(CE->getOperand(0));
    }
  }
  return NULL;
}

/// isGlobalVariable - Return true if the given value can be coerced to a
/// GlobalVariable.
static bool isGlobalVariable(Value *V) {
  if (isa<GlobalVariable>(V) || isa<ConstantPointerNull>(V)) {
    return true;
  } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
    if (CE->getOpcode() == Instruction::Cast) {
      return isa<GlobalVariable>(CE->getOperand(0));
    }
  }
  return false;
}

/// getUIntOperand - Return ith operand if it is an unsigned integer.
///
static ConstantUInt *getUIntOperand(GlobalVariable *GV, unsigned i) {
  // Make sure the GlobalVariable has an initializer.
  if (!GV->hasInitializer()) return NULL;
  
  // Get the initializer constant.
  ConstantStruct *CI = dyn_cast<ConstantStruct>(GV->getInitializer());
  if (!CI) return NULL;
  
  // Check if there is at least i + 1 operands.
  unsigned N = CI->getNumOperands();
  if (i >= N) return NULL;

  // Check constant.
  return dyn_cast<ConstantUInt>(CI->getOperand(i));
}
//===----------------------------------------------------------------------===//

/// ApplyToFields - Target the visitor to each field of the debug information
/// descriptor.
void DIVisitor::ApplyToFields(DebugInfoDesc *DD) {
  DD->ApplyToFields(this);
}

//===----------------------------------------------------------------------===//
/// DICountVisitor - This DIVisitor counts all the fields in the supplied debug
/// the supplied DebugInfoDesc.
class DICountVisitor : public DIVisitor {
private:
  unsigned Count;                       // Running count of fields.
  
public:
  DICountVisitor() : DIVisitor(), Count(0) {}
  
  // Accessors.
  unsigned getCount() const { return Count; }
  
  /// Apply - Count each of the fields.
  ///
  virtual void Apply(int &Field)             { ++Count; }
  virtual void Apply(unsigned &Field)        { ++Count; }
  virtual void Apply(int64_t &Field)         { ++Count; }
  virtual void Apply(uint64_t &Field)        { ++Count; }
  virtual void Apply(bool &Field)            { ++Count; }
  virtual void Apply(std::string &Field)     { ++Count; }
  virtual void Apply(DebugInfoDesc *&Field)  { ++Count; }
  virtual void Apply(GlobalVariable *&Field) { ++Count; }
  virtual void Apply(std::vector<DebugInfoDesc *> &Field) {
    ++Count;
  }
};

//===----------------------------------------------------------------------===//
/// DIDeserializeVisitor - This DIVisitor deserializes all the fields in the
/// supplied DebugInfoDesc.
class DIDeserializeVisitor : public DIVisitor {
private:
  DIDeserializer &DR;                   // Active deserializer.
  unsigned I;                           // Current operand index.
  ConstantStruct *CI;                   // GlobalVariable constant initializer.

public:
  DIDeserializeVisitor(DIDeserializer &D, GlobalVariable *GV)
  : DIVisitor()
  , DR(D)
  , I(0)
  , CI(cast<ConstantStruct>(GV->getInitializer()))
  {}
  
  /// Apply - Set the value of each of the fields.
  ///
  virtual void Apply(int &Field) {
    Constant *C = CI->getOperand(I++);
    Field = cast<ConstantSInt>(C)->getValue();
  }
  virtual void Apply(unsigned &Field) {
    Constant *C = CI->getOperand(I++);
    Field = cast<ConstantUInt>(C)->getValue();
  }
  virtual void Apply(int64_t &Field) {
    Constant *C = CI->getOperand(I++);
    Field = cast<ConstantSInt>(C)->getValue();
  }
  virtual void Apply(uint64_t &Field) {
    Constant *C = CI->getOperand(I++);
    Field = cast<ConstantUInt>(C)->getValue();
  }
  virtual void Apply(bool &Field) {
    Constant *C = CI->getOperand(I++);
    Field = cast<ConstantBool>(C)->getValue();
  }
  virtual void Apply(std::string &Field) {
    Constant *C = CI->getOperand(I++);
    Field = getStringValue(C);
  }
  virtual void Apply(DebugInfoDesc *&Field) {
    Constant *C = CI->getOperand(I++);
    Field = DR.Deserialize(C);
  }
  virtual void Apply(GlobalVariable *&Field) {
    Constant *C = CI->getOperand(I++);
    Field = getGlobalVariable(C);
  }
  virtual void Apply(std::vector<DebugInfoDesc *> &Field) {
    Constant *C = CI->getOperand(I++);
    GlobalVariable *GV = getGlobalVariable(C);
    ConstantArray *CA = cast<ConstantArray>(GV->getInitializer());
    Field.resize(0);
    for (unsigned i = 0, N = CA->getNumOperands(); i < N; ++i) {
      GlobalVariable *GVE = getGlobalVariable(CA->getOperand(i));
      DebugInfoDesc *DE = DR.Deserialize(GVE);
      Field.push_back(DE);
    }
  }
};

//===----------------------------------------------------------------------===//
/// DISerializeVisitor - This DIVisitor serializes all the fields in
/// the supplied DebugInfoDesc.
class DISerializeVisitor : public DIVisitor {
private:
  DISerializer &SR;                     // Active serializer.
  std::vector<Constant*> &Elements;     // Element accumulator.
  
public:
  DISerializeVisitor(DISerializer &S, std::vector<Constant*> &E)
  : DIVisitor()
  , SR(S)
  , Elements(E)
  {}
  
  /// Apply - Set the value of each of the fields.
  ///
  virtual void Apply(int &Field) {
    Elements.push_back(ConstantSInt::get(Type::IntTy, Field));
  }
  virtual void Apply(unsigned &Field) {
    Elements.push_back(ConstantUInt::get(Type::UIntTy, Field));
  }
  virtual void Apply(int64_t &Field) {
    Elements.push_back(ConstantSInt::get(Type::IntTy, Field));
  }
  virtual void Apply(uint64_t &Field) {
    Elements.push_back(ConstantUInt::get(Type::UIntTy, Field));
  }
  virtual void Apply(bool &Field) {
    Elements.push_back(ConstantBool::get(Field));
  }
  virtual void Apply(std::string &Field) {
    Elements.push_back(SR.getString(Field));
  }
  virtual void Apply(DebugInfoDesc *&Field) {
    GlobalVariable *GV = NULL;
    
    // If non-NULL the convert to global.
    if (Field) GV = SR.Serialize(Field);
    
    // FIXME - At some point should use specific type.
    const PointerType *EmptyTy = SR.getEmptyStructPtrType();
    
    if (GV) {
      // Set to pointer to global.
      Elements.push_back(ConstantExpr::getCast(GV, EmptyTy));
    } else {
      // Use NULL.
      Elements.push_back(ConstantPointerNull::get(EmptyTy));
    }
  }
  virtual void Apply(GlobalVariable *&Field) {
    const PointerType *EmptyTy = SR.getEmptyStructPtrType();
    if (Field) {
      Elements.push_back(ConstantExpr::getCast(Field, EmptyTy));
    } else {
      Elements.push_back(ConstantPointerNull::get(EmptyTy));
    }
  }
  virtual void Apply(std::vector<DebugInfoDesc *> &Field) {
    const PointerType *EmptyTy = SR.getEmptyStructPtrType();
    unsigned N = Field.size();
    ArrayType *AT = ArrayType::get(EmptyTy, N);
    std::vector<Constant *> ArrayElements;

    for (unsigned i = 0, N = Field.size(); i < N; ++i) {
      GlobalVariable *GVE = SR.Serialize(Field[i]);
      Constant *CE = ConstantExpr::getCast(GVE, EmptyTy);
      ArrayElements.push_back(cast<Constant>(CE));
    }
    
    Constant *CA = ConstantArray::get(AT, ArrayElements);
    GlobalVariable *CAGV = new GlobalVariable(AT, true,
                                              GlobalValue::InternalLinkage,
                                              CA, "llvm.dbg.array",
                                              SR.getModule());
    Constant *CAE = ConstantExpr::getCast(CAGV, EmptyTy);
    Elements.push_back(CAE);
  }
};

//===----------------------------------------------------------------------===//
/// DIGetTypesVisitor - This DIVisitor gathers all the field types in
/// the supplied DebugInfoDesc.
class DIGetTypesVisitor : public DIVisitor {
private:
  DISerializer &SR;                     // Active serializer.
  std::vector<const Type*> &Fields;     // Type accumulator.
  
public:
  DIGetTypesVisitor(DISerializer &S, std::vector<const Type*> &F)
  : DIVisitor()
  , SR(S)
  , Fields(F)
  {}
  
  /// Apply - Set the value of each of the fields.
  ///
  virtual void Apply(int &Field) {
    Fields.push_back(Type::IntTy);
  }
  virtual void Apply(unsigned &Field) {
    Fields.push_back(Type::UIntTy);
  }
  virtual void Apply(int64_t &Field) {
    Fields.push_back(Type::IntTy);
  }
  virtual void Apply(uint64_t &Field) {
    Fields.push_back(Type::UIntTy);
  }
  virtual void Apply(bool &Field) {
    Fields.push_back(Type::BoolTy);
  }
  virtual void Apply(std::string &Field) {
    Fields.push_back(SR.getStrPtrType());
  }
  virtual void Apply(DebugInfoDesc *&Field) {
    // FIXME - At some point should use specific type.
    const PointerType *EmptyTy = SR.getEmptyStructPtrType();
    Fields.push_back(EmptyTy);
  }
  virtual void Apply(GlobalVariable *&Field) {
    const PointerType *EmptyTy = SR.getEmptyStructPtrType();
    Fields.push_back(EmptyTy);
  }
  virtual void Apply(std::vector<DebugInfoDesc *> &Field) {
    const PointerType *EmptyTy = SR.getEmptyStructPtrType();
    Fields.push_back(EmptyTy);
  }
};

//===----------------------------------------------------------------------===//
/// DIVerifyVisitor - This DIVisitor verifies all the field types against
/// a constant initializer.
class DIVerifyVisitor : public DIVisitor {
private:
  DIVerifier &VR;                       // Active verifier.
  bool IsValid;                         // Validity status.
  unsigned I;                           // Current operand index.
  ConstantStruct *CI;                   // GlobalVariable constant initializer.
  
public:
  DIVerifyVisitor(DIVerifier &V, GlobalVariable *GV)
  : DIVisitor()
  , VR(V)
  , IsValid(true)
  , I(0)
  , CI(cast<ConstantStruct>(GV->getInitializer()))
  {
  }
  
  // Accessors.
  bool isValid() const { return IsValid; }
  
  /// Apply - Set the value of each of the fields.
  ///
  virtual void Apply(int &Field) {
    Constant *C = CI->getOperand(I++);
    IsValid = IsValid && isa<ConstantInt>(C);
  }
  virtual void Apply(unsigned &Field) {
    Constant *C = CI->getOperand(I++);
    IsValid = IsValid && isa<ConstantInt>(C);
  }
  virtual void Apply(int64_t &Field) {
    Constant *C = CI->getOperand(I++);
    IsValid = IsValid && isa<ConstantInt>(C);
  }
  virtual void Apply(uint64_t &Field) {
    Constant *C = CI->getOperand(I++);
    IsValid = IsValid && isa<ConstantInt>(C);
  }
  virtual void Apply(bool &Field) {
    Constant *C = CI->getOperand(I++);
    IsValid = IsValid && isa<ConstantBool>(C);
  }
  virtual void Apply(std::string &Field) {
    Constant *C = CI->getOperand(I++);
    IsValid = IsValid && isStringValue(C);
  }
  virtual void Apply(DebugInfoDesc *&Field) {
    // FIXME - Prepare the correct descriptor.
    Constant *C = CI->getOperand(I++);
    IsValid = IsValid && isGlobalVariable(C);
  }
  virtual void Apply(GlobalVariable *&Field) {
    Constant *C = CI->getOperand(I++);
    IsValid = IsValid && isGlobalVariable(C);
  }
  virtual void Apply(std::vector<DebugInfoDesc *> &Field) {
    Constant *C = CI->getOperand(I++);
    IsValid = IsValid && isGlobalVariable(C);
    if (!IsValid) return;

    GlobalVariable *GV = getGlobalVariable(C);
    IsValid = IsValid && GV && GV->hasInitializer();
    if (!IsValid) return;
    
    ConstantArray *CA = dyn_cast<ConstantArray>(GV->getInitializer());
    IsValid = IsValid && CA;
    if (!IsValid) return;

    for (unsigned i = 0, N = CA->getNumOperands(); IsValid && i < N; ++i) {
      IsValid = IsValid && isGlobalVariable(CA->getOperand(i));
      if (!IsValid) return;
    
      GlobalVariable *GVE = getGlobalVariable(CA->getOperand(i));
      VR.Verify(GVE);
    }
  }
};


//===----------------------------------------------------------------------===//

/// TagFromGlobal - Returns the Tag number from a debug info descriptor
/// GlobalVariable.  
unsigned DebugInfoDesc::TagFromGlobal(GlobalVariable *GV) {
  ConstantUInt *C = getUIntOperand(GV, 0);
  return C ? (unsigned)C->getValue() : (unsigned)DW_TAG_invalid;
}

/// DescFactory - Create an instance of debug info descriptor based on Tag.
/// Return NULL if not a recognized Tag.
DebugInfoDesc *DebugInfoDesc::DescFactory(unsigned Tag) {
  switch (Tag) {
  case DW_TAG_anchor:           return new AnchorDesc();
  case DW_TAG_compile_unit:     return new CompileUnitDesc();
  case DW_TAG_variable:         return new GlobalVariableDesc();
  case DW_TAG_subprogram:       return new SubprogramDesc();
  case DW_TAG_base_type:        return new BasicTypeDesc();
  case DW_TAG_typedef:
  case DW_TAG_pointer_type:         
  case DW_TAG_reference_type:
  case DW_TAG_const_type:
  case DW_TAG_volatile_type:         
  case DW_TAG_restrict_type:    return new DerivedTypeDesc(Tag);
  case DW_TAG_array_type:
  case DW_TAG_structure_type:
  case DW_TAG_union_type:
  case DW_TAG_enumeration_type: return new CompositeTypeDesc(Tag);
  case DW_TAG_subrange_type:    return new SubrangeDesc();
  case DW_TAG_enumerator:       return new EnumeratorDesc();
  default: break;
  }
  return NULL;
}

/// getLinkage - get linkage appropriate for this type of descriptor.
///
GlobalValue::LinkageTypes DebugInfoDesc::getLinkage() const {
  return GlobalValue::InternalLinkage;
}

/// ApplyToFields - Target the vistor to the fields of the descriptor.
///
void DebugInfoDesc::ApplyToFields(DIVisitor *Visitor) {
  Visitor->Apply(Tag);
}

//===----------------------------------------------------------------------===//

AnchorDesc::AnchorDesc()
: DebugInfoDesc(DW_TAG_anchor)
, Name("")
{}
AnchorDesc::AnchorDesc(const std::string &N)
: DebugInfoDesc(DW_TAG_anchor)
, Name(N)
{}

// Implement isa/cast/dyncast.
bool AnchorDesc::classof(const DebugInfoDesc *D) {
  return D->getTag() == DW_TAG_anchor;
}
  
/// getLinkage - get linkage appropriate for this type of descriptor.
///
GlobalValue::LinkageTypes AnchorDesc::getLinkage() const {
  return GlobalValue::LinkOnceLinkage;
}

/// ApplyToFields - Target the visitor to the fields of the TransUnitDesc.
///
void AnchorDesc::ApplyToFields(DIVisitor *Visitor) {
  DebugInfoDesc::ApplyToFields(Visitor);
  
  Visitor->Apply(Name);
}

/// getDescString - Return a string used to compose global names and labels.
///
const char *AnchorDesc::getDescString() const {
  return Name.c_str();
}

/// getTypeString - Return a string used to label this descriptors type.
///
const char *AnchorDesc::getTypeString() const {
  return "llvm.dbg.anchor.type";
}

#ifndef NDEBUG
void AnchorDesc::dump() {
  std::cerr << getDescString() << " "
            << "Tag(" << getTag() << "), "
            << "Name(" << Name << ")\n";
}
#endif

//===----------------------------------------------------------------------===//

AnchoredDesc::AnchoredDesc(unsigned T)
: DebugInfoDesc(T)
, Anchor(NULL)
{}

/// ApplyToFields - Target the visitor to the fields of the AnchoredDesc.
///
void AnchoredDesc::ApplyToFields(DIVisitor *Visitor) {
  DebugInfoDesc::ApplyToFields(Visitor);

  Visitor->Apply((DebugInfoDesc *&)Anchor);
}

//===----------------------------------------------------------------------===//

CompileUnitDesc::CompileUnitDesc()
: AnchoredDesc(DW_TAG_compile_unit)
, DebugVersion(LLVMDebugVersion)
, Language(0)
, FileName("")
, Directory("")
, Producer("")
{}

// Implement isa/cast/dyncast.
bool CompileUnitDesc::classof(const DebugInfoDesc *D) {
  return D->getTag() == DW_TAG_compile_unit;
}

/// DebugVersionFromGlobal - Returns the version number from a compile unit
/// GlobalVariable.
unsigned CompileUnitDesc::DebugVersionFromGlobal(GlobalVariable *GV) {
  ConstantUInt *C = getUIntOperand(GV, 2);
  return C ? (unsigned)C->getValue() : (unsigned)DW_TAG_invalid;
}
  
/// ApplyToFields - Target the visitor to the fields of the CompileUnitDesc.
///
void CompileUnitDesc::ApplyToFields(DIVisitor *Visitor) {
  AnchoredDesc::ApplyToFields(Visitor);

  Visitor->Apply(DebugVersion);
  Visitor->Apply(Language);
  Visitor->Apply(FileName);
  Visitor->Apply(Directory);
  Visitor->Apply(Producer);
}

/// getDescString - Return a string used to compose global names and labels.
///
const char *CompileUnitDesc::getDescString() const {
  return "llvm.dbg.compile_unit";
}

/// getTypeString - Return a string used to label this descriptors type.
///
const char *CompileUnitDesc::getTypeString() const {
  return "llvm.dbg.compile_unit.type";
}

/// getAnchorString - Return a string used to label this descriptor's anchor.
///
const char *CompileUnitDesc::getAnchorString() const {
  return "llvm.dbg.compile_units";
}

#ifndef NDEBUG
void CompileUnitDesc::dump() {
  std::cerr << getDescString() << " "
            << "Tag(" << getTag() << "), "
            << "Anchor(" << getAnchor() << "), "
            << "DebugVersion(" << DebugVersion << "), "
            << "Language(" << Language << "), "
            << "FileName(\"" << FileName << "\"), "
            << "Directory(\"" << Directory << "\"), "
            << "Producer(\"" << Producer << "\")\n";
}
#endif

//===----------------------------------------------------------------------===//

TypeDesc::TypeDesc(unsigned T)
: DebugInfoDesc(T)
, Context(NULL)
, Name("")
, File(NULL)
, Size(0)
{}

/// ApplyToFields - Target the visitor to the fields of the TypeDesc.
///
void TypeDesc::ApplyToFields(DIVisitor *Visitor) {
  DebugInfoDesc::ApplyToFields(Visitor);
  
  Visitor->Apply(Context);
  Visitor->Apply(Name);
  Visitor->Apply((DebugInfoDesc *&)File);
  Visitor->Apply(Line);
  Visitor->Apply(Size);
}

/// getDescString - Return a string used to compose global names and labels.
///
const char *TypeDesc::getDescString() const {
  return "llvm.dbg.type";
}

/// getTypeString - Return a string used to label this descriptor's type.
///
const char *TypeDesc::getTypeString() const {
  return "llvm.dbg.type.type";
}

#ifndef NDEBUG
void TypeDesc::dump() {
  std::cerr << getDescString() << " "
            << "Tag(" << getTag() << "), "
            << "Context(" << Context << "), "
            << "Name(\"" << Name << "\"), "
            << "File(" << File << "), "
            << "Line(" << Line << "), "
            << "Size(" << Size << ")\n";
}
#endif

//===----------------------------------------------------------------------===//

BasicTypeDesc::BasicTypeDesc()
: TypeDesc(DW_TAG_base_type)
, Encoding(0)
{}

// Implement isa/cast/dyncast.
bool BasicTypeDesc::classof(const DebugInfoDesc *D) {
  return D->getTag() == DW_TAG_base_type;
}

/// ApplyToFields - Target the visitor to the fields of the BasicTypeDesc.
///
void BasicTypeDesc::ApplyToFields(DIVisitor *Visitor) {
  TypeDesc::ApplyToFields(Visitor);
  
  Visitor->Apply(Encoding);
}

/// getDescString - Return a string used to compose global names and labels.
///
const char *BasicTypeDesc::getDescString() const {
  return "llvm.dbg.basictype";
}

/// getTypeString - Return a string used to label this descriptor's type.
///
const char *BasicTypeDesc::getTypeString() const {
  return "llvm.dbg.basictype.type";
}

#ifndef NDEBUG
void BasicTypeDesc::dump() {
  std::cerr << getDescString() << " "
            << "Tag(" << getTag() << "), "
            << "Context(" << getContext() << "), "
            << "Name(\"" << getName() << "\"), "
            << "Size(" << getSize() << "), "
            << "Encoding(" << Encoding << ")\n";
}
#endif

//===----------------------------------------------------------------------===//

DerivedTypeDesc::DerivedTypeDesc(unsigned T)
: TypeDesc(T)
, FromType(NULL)
{}

// Implement isa/cast/dyncast.
bool DerivedTypeDesc::classof(const DebugInfoDesc *D) {
  unsigned T =  D->getTag();
  switch (T) {
  case DW_TAG_typedef:
  case DW_TAG_pointer_type:
  case DW_TAG_reference_type:
  case DW_TAG_const_type:
  case DW_TAG_volatile_type:
  case DW_TAG_restrict_type:
    return true;
  default: break;
  }
  return false;
}

/// ApplyToFields - Target the visitor to the fields of the DerivedTypeDesc.
///
void DerivedTypeDesc::ApplyToFields(DIVisitor *Visitor) {
  TypeDesc::ApplyToFields(Visitor);
  
  Visitor->Apply((DebugInfoDesc *&)FromType);
}

/// getDescString - Return a string used to compose global names and labels.
///
const char *DerivedTypeDesc::getDescString() const {
  return "llvm.dbg.derivedtype";
}

/// getTypeString - Return a string used to label this descriptor's type.
///
const char *DerivedTypeDesc::getTypeString() const {
  return "llvm.dbg.derivedtype.type";
}

#ifndef NDEBUG
void DerivedTypeDesc::dump() {
  std::cerr << getDescString() << " "
            << "Tag(" << getTag() << "), "
            << "Context(" << getContext() << "), "
            << "Name(\"" << getName() << "\"), "
            << "Size(" << getSize() << "), "
            << "File(" << getFile() << "), "
            << "Line(" << getLine() << "), "
            << "FromType(" << FromType << ")\n";
}
#endif

//===----------------------------------------------------------------------===//

CompositeTypeDesc::CompositeTypeDesc(unsigned T)
: DerivedTypeDesc(T)
, Elements()
{}
  
// Implement isa/cast/dyncast.
bool CompositeTypeDesc::classof(const DebugInfoDesc *D) {
  unsigned T =  D->getTag();
  switch (T) {
  case DW_TAG_array_type:
  case DW_TAG_structure_type:
  case DW_TAG_union_type:
  case DW_TAG_enumeration_type:
    return true;
  default: break;
  }
  return false;
}

/// ApplyToFields - Target the visitor to the fields of the CompositeTypeDesc.
///
void CompositeTypeDesc::ApplyToFields(DIVisitor *Visitor) {
  DerivedTypeDesc::ApplyToFields(Visitor);
  
  Visitor->Apply(Elements);
}

/// getDescString - Return a string used to compose global names and labels.
///
const char *CompositeTypeDesc::getDescString() const {
  return "llvm.dbg.compositetype";
}

/// getTypeString - Return a string used to label this descriptor's type.
///
const char *CompositeTypeDesc::getTypeString() const {
  return "llvm.dbg.compositetype.type";
}

#ifndef NDEBUG
void CompositeTypeDesc::dump() {
  std::cerr << getDescString() << " "
            << "Tag(" << getTag() << "), "
            << "Context(" << getContext() << "), "
            << "Name(\"" << getName() << "\"), "
            << "Size(" << getSize() << "), "
            << "File(" << getFile() << "), "
            << "Line(" << getLine() << "), "
            << "FromType(" << getFromType() << "), "
            << "Elements.size(" << Elements.size() << ")\n";
}
#endif

//===----------------------------------------------------------------------===//

SubrangeDesc::SubrangeDesc()
: DebugInfoDesc(DW_TAG_subrange_type)
, Lo(0)
, Hi(0)
{}

// Implement isa/cast/dyncast.
bool SubrangeDesc::classof(const DebugInfoDesc *D) {
  return D->getTag() == DW_TAG_subrange_type;
}

/// ApplyToFields - Target the visitor to the fields of the SubrangeDesc.
///
void SubrangeDesc::ApplyToFields(DIVisitor *Visitor) {
  DebugInfoDesc::ApplyToFields(Visitor);

  Visitor->Apply(Lo);
  Visitor->Apply(Hi);
}

/// getDescString - Return a string used to compose global names and labels.
///
const char *SubrangeDesc::getDescString() const {
  return "llvm.dbg.subrange";
}
  
/// getTypeString - Return a string used to label this descriptor's type.
///
const char *SubrangeDesc::getTypeString() const {
  return "llvm.dbg.subrange.type";
}

#ifndef NDEBUG
void SubrangeDesc::dump() {
  std::cerr << getDescString() << " "
            << "Tag(" << getTag() << "), "
            << "Lo(" << Lo << "), "
            << "Hi(" << Hi << ")\n";
}
#endif

//===----------------------------------------------------------------------===//

EnumeratorDesc::EnumeratorDesc()
: DebugInfoDesc(DW_TAG_enumerator)
, Name("")
, Value(0)
{}

// Implement isa/cast/dyncast.
bool EnumeratorDesc::classof(const DebugInfoDesc *D) {
  return D->getTag() == DW_TAG_enumerator;
}

/// ApplyToFields - Target the visitor to the fields of the EnumeratorDesc.
///
void EnumeratorDesc::ApplyToFields(DIVisitor *Visitor) {
  DebugInfoDesc::ApplyToFields(Visitor);

  Visitor->Apply(Name);
  Visitor->Apply(Value);
}

/// getDescString - Return a string used to compose global names and labels.
///
const char *EnumeratorDesc::getDescString() const {
  return "llvm.dbg.enumerator";
}
  
/// getTypeString - Return a string used to label this descriptor's type.
///
const char *EnumeratorDesc::getTypeString() const {
  return "llvm.dbg.enumerator.type";
}

#ifndef NDEBUG
void EnumeratorDesc::dump() {
  std::cerr << getDescString() << " "
            << "Tag(" << getTag() << "), "
            << "Name(" << Name << "), "
            << "Value(" << Value << ")\n";
}
#endif

//===----------------------------------------------------------------------===//

GlobalDesc::GlobalDesc(unsigned T)
: AnchoredDesc(T)
, Context(0)
, Name("")
, TyDesc(NULL)
, IsStatic(false)
, IsDefinition(false)
{}

/// ApplyToFields - Target the visitor to the fields of the global.
///
void GlobalDesc::ApplyToFields(DIVisitor *Visitor) {
  AnchoredDesc::ApplyToFields(Visitor);

  Visitor->Apply(Context);
  Visitor->Apply(Name);
  Visitor->Apply((DebugInfoDesc *&)TyDesc);
  Visitor->Apply(IsStatic);
  Visitor->Apply(IsDefinition);
}

//===----------------------------------------------------------------------===//

GlobalVariableDesc::GlobalVariableDesc()
: GlobalDesc(DW_TAG_variable)
, Global(NULL)
{}

// Implement isa/cast/dyncast.
bool GlobalVariableDesc::classof(const DebugInfoDesc *D) {
  return D->getTag() == DW_TAG_variable; 
}

/// ApplyToFields - Target the visitor to the fields of the GlobalVariableDesc.
///
void GlobalVariableDesc::ApplyToFields(DIVisitor *Visitor) {
  GlobalDesc::ApplyToFields(Visitor);

  Visitor->Apply(Global);
  Visitor->Apply(Line);
}

/// getDescString - Return a string used to compose global names and labels.
///
const char *GlobalVariableDesc::getDescString() const {