path: root/lib/Analysis/DebugInfo.cpp

//===--- DebugInfo.cpp - Debug Information Helper Classes -----------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the helper classes used to build and interpret debug
// information in LLVM IR form.
//
//===----------------------------------------------------------------------===//

#include "llvm/Analysis/DebugInfo.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Intrinsics.h"
#include "llvm/IntrinsicInst.h"
#include "llvm/Instructions.h"
#include "llvm/Module.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/Support/Streams.h"
using namespace llvm;

//===----------------------------------------------------------------------===//
// DIDescriptor
//===----------------------------------------------------------------------===//

DIDescriptor::DIDescriptor(GlobalVariable *gv, unsigned RequiredTag) {
  GV = gv;
  
  // If this is non-null, check to see if the Tag matches.  If not, set to null.
  if (GV && getTag() != RequiredTag)
    GV = 0;
}


std::string DIDescriptor::getStringField(unsigned Elt) const {
  if (GV == 0) return "";
  Constant *C = GV->getInitializer();
  if (C == 0 || Elt >= C->getNumOperands())
    return "";
  
  std::string Result;
  // Fills in the string if it succeeds
  if (!GetConstantStringInfo(C->getOperand(Elt), Result))
    Result.clear();
  return Result;
}

uint64_t DIDescriptor::getUInt64Field(unsigned Elt) const {
  if (GV == 0) return 0;
  Constant *C = GV->getInitializer();
  if (C == 0 || Elt >= C->getNumOperands())
    return 0;
  if (ConstantInt *CI = dyn_cast<ConstantInt>(C->getOperand(Elt)))
    return CI->getZExtValue();
  return 0;
}


DIDescriptor DIDescriptor::getDescriptorField(unsigned Elt) const {
  if (GV == 0) return DIDescriptor();
  Constant *C = GV->getInitializer();
  if (C == 0 || Elt >= C->getNumOperands())
    return DIDescriptor();
  C = C->getOperand(Elt);
  return DIDescriptor(dyn_cast<GlobalVariable>(C->stripPointerCasts()));
}

GlobalVariable *DIDescriptor::getGlobalVariableField(unsigned Elt) const {
  if (GV == 0) return 0;
  Constant *C = GV->getInitializer();
  if (C == 0 || Elt >= C->getNumOperands())
    return 0;
  C = C->getOperand(Elt);
  
  return dyn_cast<GlobalVariable>(C->stripPointerCasts());
}



//===----------------------------------------------------------------------===//
// Simple Descriptor Constructors and other Methods
//===----------------------------------------------------------------------===//

DIAnchor::DIAnchor(GlobalVariable *GV)
  : DIDescriptor(GV, dwarf::DW_TAG_anchor) {}
DIEnumerator::DIEnumerator(GlobalVariable *GV)
  : DIDescriptor(GV, dwarf::DW_TAG_enumerator) {}
DISubrange::DISubrange(GlobalVariable *GV)
  : DIDescriptor(GV, dwarf::DW_TAG_subrange_type) {}
DICompileUnit::DICompileUnit(GlobalVariable *GV)
  : DIDescriptor(GV, dwarf::DW_TAG_compile_unit) {}
DIBasicType::DIBasicType(GlobalVariable *GV)
  : DIType(GV, dwarf::DW_TAG_base_type) {}
DISubprogram::DISubprogram(GlobalVariable *GV)
  : DIGlobal(GV, dwarf::DW_TAG_subprogram) {}
DIGlobalVariable::DIGlobalVariable(GlobalVariable *GV)
  : DIGlobal(GV, dwarf::DW_TAG_variable) {}
DIBlock::DIBlock(GlobalVariable *GV)
  : DIDescriptor(GV, dwarf::DW_TAG_lexical_block) {}
// needed by DIVariable::getType()
DIType::DIType(GlobalVariable *gv) : DIDescriptor(gv) {
  if (!gv) return;
  unsigned tag = getTag();
  if (tag != dwarf::DW_TAG_base_type && !DIDerivedType::isDerivedType(tag) &&
      !DICompositeType::isCompositeType(tag))
    GV = 0;
}

/// isDerivedType - Return true if the specified tag is legal for
/// DIDerivedType.
bool DIType::isDerivedType(unsigned Tag) {
  switch (Tag) {
  case dwarf::DW_TAG_typedef:
  case dwarf::DW_TAG_pointer_type:
  case dwarf::DW_TAG_reference_type:
  case dwarf::DW_TAG_const_type:
  case dwarf::<