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/LLVMContext.h"
#include "llvm/Module.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/Support/Dwarf.h"
#include "llvm/Support/DebugLoc.h"
#include "llvm/Support/Streams.h"

using namespace llvm;
using namespace llvm::dwarf;

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

/// ValidDebugInfo - Return true if V represents valid debug info value.
bool DIDescriptor::ValidDebugInfo(Value *V, CodeGenOpt::Level OptLevel) {
  if (!V)
    return false;

  GlobalVariable *GV = dyn_cast<GlobalVariable>(V->stripPointerCasts());
  if (!GV)
    return false;

  if (!GV->hasInternalLinkage () && !GV->hasLinkOnceLinkage())
    return false;

  DIDescriptor DI(GV);

  // Check current version. Allow Version6 for now.
  unsigned Version = DI.getVersion();
  if (Version != LLVMDebugVersion && Version != LLVMDebugVersion6)
    return false;

  unsigned Tag = DI.getTag();
  switch (Tag) {
  case DW_TAG_variable:
    assert(DIVariable(GV).Verify() && "Invalid DebugInfo value");
    break;
  case DW_TAG_compile_unit:
    assert(DICompileUnit(GV).Verify() && "Invalid DebugInfo value");
    break;
  case DW_TAG_subprogram:
    assert(DISubprogram(GV).Verify() && "Invalid DebugInfo value");
    break;
  case DW_TAG_lexical_block:
    // FIXME: This interfers with the quality of generated code during
    // optimization.
    if (OptLevel != CodeGenOpt::None)
      return false;
    // FALLTHROUGH
  default:
    break;
  }

  return true;
}

DIDescriptor::DIDescriptor(GlobalVariable *GV, unsigned RequiredTag) {
  DbgGV