vendor/llvm-project/llvmorg-12-init-17869-g8e464dd76bef

1 files changed, 147 insertions, 141 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
index e958f38e486b..118b5fcc3bf6 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -13,7 +13,6 @@
 #include "DwarfUnit.h"
 #include "AddressPool.h"
 #include "DwarfCompileUnit.h"
-#include "DwarfDebug.h"
 #include "DwarfExpression.h"
 #include "llvm/ADT/APFloat.h"
 #include "llvm/ADT/APInt.h"
@@ -84,15 +83,14 @@ unsigned DIEDwarfExpression::getTemporaryBufferSize() {
 void DIEDwarfExpression::commitTemporaryBuffer() { OutDIE.takeValues(TmpDIE); }
 
 bool DIEDwarfExpression::isFrameRegister(const TargetRegisterInfo &TRI,
-                                         unsigned MachineReg) {
+                                         llvm::Register MachineReg) {
   return MachineReg == TRI.getFrameRegister(*AP.MF);
 }
 
 DwarfUnit::DwarfUnit(dwarf::Tag UnitTag, const DICompileUnit *Node,
                      AsmPrinter *A, DwarfDebug *DW, DwarfFile *DWU)
-    : DIEUnit(A->getDwarfVersion(), A->MAI->getCodePointerSize(), UnitTag),
-      CUNode(Node), Asm(A), DD(DW), DU(DWU), IndexTyDie(nullptr) {
-}
+    : DIEUnit(UnitTag), CUNode(Node), Asm(A), DD(DW), DU(DWU),
+      IndexTyDie(nullptr) {}
 
 DwarfTypeUnit::DwarfTypeUnit(DwarfCompileUnit &CU, AsmPrinter *A,
                              DwarfDebug *DW, DwarfFile *DWU,
@@ -301,27 +299,7 @@ void DwarfUnit::addLabel(DIELoc &Die, dwarf::Form Form, const MCSymbol *Label) {
 
 void DwarfUnit::addSectionOffset(DIE &Die, dwarf::Attribute Attribute,
                                  uint64_t Integer) {
-  if (DD->getDwarfVersion() >= 4)
-    addUInt(Die, Attribute, dwarf::DW_FORM_sec_offset, Integer);
-  else
-    addUInt(Die, Attribute, dwarf::DW_FORM_data4, Integer);
-}
-
-Optional<MD5::MD5Result> DwarfUnit::getMD5AsBytes(const DIFile *File) const {
-  assert(File);
-  if (DD->getDwarfVersion() < 5)
-    return None;
-  Optional<DIFile::ChecksumInfo<StringRef>> Checksum = File->getChecksum();
-  if (!Checksum || Checksum->Kind != DIFile::CSK_MD5)
-    return None;
-
-  // Convert the string checksum to an MD5Result for the streamer.
-  // The verifier validates the checksum so we assume it's okay.
-  // An MD5 checksum is 16 bytes.
-  std::string ChecksumString = fromHex(Checksum->Value);
-  MD5::MD5Result CKMem;
-  std::copy(ChecksumString.begin(), ChecksumString.end(), CKMem.Bytes.data());
-  return CKMem;
+  addUInt(Die, Attribute, DD->getDwarfSectionOffsetForm(), Integer);
 }
 
 unsigned DwarfTypeUnit::getOrCreateSourceID(const DIFile *File) {
@@ -332,10 +310,9 @@ unsigned DwarfTypeUnit::getOrCreateSourceID(const DIFile *File) {
     // This is a split type unit that needs a line table.
     addSectionOffset(getUnitDie(), dwarf::DW_AT_stmt_list, 0);
   }
-  return SplitLineTable->getFile(File->getDirectory(), File->getFilename(),
-                                 getMD5AsBytes(File),
-                                 Asm->OutContext.getDwarfVersion(),
-                                 File->getSource());
+  return SplitLineTable->getFile(
+      File->getDirectory(), File->getFilename(), DD->getMD5AsBytes(File),
+      Asm->OutContext.getDwarfVersion(), File->getSource());
 }
 
 void DwarfUnit::addOpAddress(DIELoc &Die, const MCSymbol *Sym) {
@@ -353,7 +330,7 @@ void DwarfUnit::addOpAddress(DIELoc &Die, const MCSymbol *Sym) {
   }
 
   addUInt(Die, dwarf::DW_FORM_data1, dwarf::DW_OP_addr);
-  addLabel(Die, dwarf::DW_FORM_udata, Sym);
+  addLabel(Die, dwarf::DW_FORM_addr, Sym);
 }
 
 void DwarfUnit::addLabelDelta(DIE &Die, dwarf::Attribute Attribute,
@@ -457,77 +434,6 @@ void DwarfUnit::addSourceLine(DIE &Die, const DIObjCProperty *Ty) {
   addSourceLine(Die, Ty->getLine(), Ty->getFile());
 }
 
-/// Return true if type encoding is unsigned.
-static bool isUnsignedDIType(DwarfDebug *DD, const DIType *Ty) {
-  if (auto *CTy = dyn_cast<DICompositeType>(Ty)) {
-    // FIXME: Enums without a fixed underlying type have unknown signedness
-    // here, leading to incorrectly emitted constants.
-    if (CTy->getTag() == dwarf::DW_TAG_enumeration_type)
-      return false;
-
-    // (Pieces of) aggregate types that get hacked apart by SROA may be
-    // represented by a constant. Encode them as unsigned bytes.
-    return true;
-  }
-
-  if (auto *DTy = dyn_cast<DIDerivedType>(Ty)) {
-    dwarf::Tag T = (dwarf::Tag)Ty->getTag();
-    // Encode pointer constants as unsigned bytes. This is used at least for
-    // null pointer constant emission.
-    // FIXME: reference and rvalue_reference /probably/ shouldn't be allowed
-    // here, but accept them for now due to a bug in SROA producing bogus
-    // dbg.values.
-    if (T == dwarf::DW_TAG_pointer_type ||
-        T == dwarf::DW_TAG_ptr_to_member_type ||
-        T == dwarf::DW_TAG_reference_type ||
-        T == dwarf::DW_TAG_rvalue_reference_type)
-      return true;
-    assert(T == dwarf::DW_TAG_typedef || T == dwarf::DW_TAG_const_type ||
-           T == dwarf::DW_TAG_volatile_type ||
-           T == dwarf::DW_TAG_restrict_type || T == dwarf::DW_TAG_atomic_type);
-    assert(DTy->getBaseType() && "Expected valid base type");
-    return isUnsignedDIType(DD, DTy->getBaseType());
-  }
-
-  auto *BTy = cast<DIBasicType>(Ty);
-  unsigned Encoding = BTy->getEncoding();
-  assert((Encoding == dwarf::DW_ATE_unsigned ||
-          Encoding == dwarf::DW_ATE_unsigned_char ||
-          Encoding == dwarf::DW_ATE_signed ||
-          Encoding == dwarf::DW_ATE_signed_char ||
-          Encoding == dwarf::DW_ATE_float || Encoding == dwarf::DW_ATE_UTF ||
-          Encoding == dwarf::DW_ATE_boolean ||
-          (Ty->getTag() == dwarf::DW_TAG_unspecified_type &&
-           Ty->getName() == "decltype(nullptr)")) &&
-         "Unsupported encoding");
-  return Encoding == dwarf::DW_ATE_unsigned ||
-         Encoding == dwarf::DW_ATE_unsigned_char ||
-         Encoding == dwarf::DW_ATE_UTF || Encoding == dwarf::DW_ATE_boolean ||
-         Ty->getTag() == dwarf::DW_TAG_unspecified_type;
-}
-
-void DwarfUnit::addConstantFPValue(DIE &Die, const MachineOperand &MO) {
-  assert(MO.isFPImm() && "Invalid machine operand!");
-  DIEBlock *Block = new (DIEValueAllocator) DIEBlock;
-  APFloat FPImm = MO.getFPImm()->getValueAPF();
-
-  // Get the raw data form of the floating point.
-  const APInt FltVal = FPImm.bitcastToAPInt();
-  const char *FltPtr = (const char *)FltVal.getRawData();
-
-  int NumBytes = FltVal.getBitWidth() / 8; // 8 bits per byte.
-  bool LittleEndian = Asm->getDataLayout().isLittleEndian();
-  int Incr = (LittleEndian ? 1 : -1);
-  int Start = (LittleEndian ? 0 : NumBytes - 1);
-  int Stop = (LittleEndian ? NumBytes : -1);
-
-  // Output the constant to DWARF one byte at a time.
-  for (; Start != Stop; Start += Incr)
-    addUInt(*Block, dwarf::DW_FORM_data1, (unsigned char)0xFF & FltPtr[Start]);
-
-  addBlock(Die, dwarf::DW_AT_const_value, Block);
-}
-
 void DwarfUnit::addConstantFPValue(DIE &Die, const ConstantFP *CFP) {
   // Pass this down to addConstantValue as an unsigned bag of bits.
   addConstantValue(Die, CFP->getValueAPF().bitcastToAPInt(), true);
@@ -538,15 +444,8 @@ void DwarfUnit::addConstantValue(DIE &Die, const ConstantInt *CI,
   addConstantValue(Die, CI->getValue(), Ty);
 }
 
-void DwarfUnit::addConstantValue(DIE &Die, const MachineOperand &MO,
-                                 const DIType *Ty) {
-  assert(MO.isImm() && "Invalid machine operand!");
-
-  addConstantValue(Die, isUnsignedDIType(DD, Ty), MO.getImm());
-}
-
 void DwarfUnit::addConstantValue(DIE &Die, uint64_t Val, const DIType *Ty) {
-  addConstantValue(Die, isUnsignedDIType(DD, Ty), Val);
+  addConstantValue(Die, DD->isUnsignedDIType(Ty), Val);
 }
 
 void DwarfUnit::addConstantValue(DIE &Die, bool Unsigned, uint64_t Val) {
@@ -557,7 +456,7 @@ void DwarfUnit::addConstantValue(DIE &Die, bool Unsigned, uint64_t Val) {
 }
 
 void DwarfUnit::addConstantValue(DIE &Die, const APInt &Val, const DIType *Ty) {
-  addConstantValue(Die, Val, isUnsignedDIType(DD, Ty));
+  addConstantValue(Die, Val, DD->isUnsignedDIType(Ty));
 }
 
 void DwarfUnit::addConstantValue(DIE &Die, const APInt &Val, bool Unsigned) {
@@ -654,6 +553,8 @@ DIE *DwarfUnit::createTypeDIE(const DIScope *Context, DIE &ContextDIE,
 
   if (auto *BT = dyn_cast<DIBasicType>(Ty))
     constructTypeDIE(TyDIE, BT);
+  else if (auto *ST = dyn_cast<DIStringType>(Ty))
+    constructTypeDIE(TyDIE, ST);
   else if (auto *STy = dyn_cast<DISubroutineType>(Ty))
     constructTypeDIE(TyDIE, STy);
   else if (auto *CTy = dyn_cast<DICompositeType>(Ty)) {
@@ -772,8 +673,9 @@ void DwarfUnit::constructTypeDIE(DIE &Buffer, const DIBasicType *BTy) {
   if (BTy->getTag() == dwarf::DW_TAG_unspecified_type)
     return;
 
-  addUInt(Buffer, dwarf::DW_AT_encoding, dwarf::DW_FORM_data1,
-          BTy->getEncoding());
+  if (BTy->getTag() != dwarf::DW_TAG_string_type)
+    addUInt(Buffer, dwarf::DW_AT_encoding, dwarf::DW_FORM_data1,
+            BTy->getEncoding());
 
   uint64_t Size = BTy->getSizeInBits() >> 3;
   addUInt(Buffer, dwarf::DW_AT_byte_size, None, Size);
@@ -784,6 +686,37 @@ void DwarfUnit::constructTypeDIE(DIE &Buffer, const DIBasicType *BTy) {
     addUInt(Buffer, dwarf::DW_AT_endianity, None, dwarf::DW_END_little);
 }
 
+void DwarfUnit::constructTypeDIE(DIE &Buffer, const DIStringType *STy) {
+  // Get core information.
+  StringRef Name = STy->getName();
+  // Add name if not anonymous or intermediate type.
+  if (!Name.empty())
+    addString(Buffer, dwarf::DW_AT_name, Name);
+
+  if (DIVariable *Var = STy->getStringLength()) {
+    if (auto *VarDIE = getDIE(Var))
+      addDIEEntry(Buffer, dwarf::DW_AT_string_length, *VarDIE);
+  } else if (DIExpression *Expr = STy->getStringLengthExp()) {
+    DIELoc *Loc = new (DIEValueAllocator) DIELoc;
+    DIEDwarfExpression DwarfExpr(*Asm, getCU(), *Loc);
+    // This is to describe the memory location of the
+    // length of a Fortran deferred length string, so
+    // lock it down as such.
+    DwarfExpr.setMemoryLocationKind();
+    DwarfExpr.addExpression(Expr);
+    addBlock(Buffer, dwarf::DW_AT_string_length, DwarfExpr.finalize());
+  } else {
+    uint64_t Size = STy->getSizeInBits() >> 3;
+    addUInt(Buffer, dwarf::DW_AT_byte_size, None, Size);
+  }
+
+  if (STy->getEncoding()) {
+    // For eventual Unicode support.
+    addUInt(Buffer, dwarf::DW_AT_encoding, dwarf::DW_FORM_data1,
+            STy->getEncoding());
+  }
+}
+
 void DwarfUnit::constructTypeDIE(DIE &Buffer, const DIDerivedType *DTy) {
   // Get core information.
   StringRef Name = DTy->getName();
@@ -910,6 +843,11 @@ void DwarfUnit::constructTypeDIE(DIE &Buffer, const DICompositeType *CTy) {
       }
     }
 
+    // Add template parameters to a class, structure or union types.
+    if (Tag == dwarf::DW_TAG_class_type ||
+        Tag == dwarf::DW_TAG_structure_type || Tag == dwarf::DW_TAG_union_type)
+      addTemplateParams(Buffer, CTy->getTemplateParams());
+
     // Add elements to structure type.
     DINodeArray Elements = CTy->getElements();
     for (const auto *Element : Elements) {
@@ -929,7 +867,7 @@ void DwarfUnit::constructTypeDIE(DIE &Buffer, const DICompositeType *CTy) {
           DIE &Variant = createAndAddDIE(dwarf::DW_TAG_variant, Buffer);
           if (const ConstantInt *CI =
               dyn_cast_or_null<ConstantInt>(DDTy->getDiscriminantValue())) {
-            if (isUnsignedDIType(DD, Discriminator->getBaseType()))
+            if (DD->isUnsignedDIType(Discriminator->getBaseType()))
               addUInt(Variant, dwarf::DW_AT_discr_value, None, CI->getZExtValue());
             else
               addSInt(Variant, dwarf::DW_AT_discr_value, None, CI->getSExtValue());
@@ -979,12 +917,6 @@ void DwarfUnit::constructTypeDIE(DIE &Buffer, const DICompositeType *CTy) {
     if (CTy->isObjcClassComplete())
       addFlag(Buffer, dwarf::DW_AT_APPLE_objc_complete_type);
 
-    // Add template parameters to a class, structure or union types.
-    // FIXME: The support isn't in the metadata for this yet.
-    if (Tag == dwarf::DW_TAG_class_type ||
-        Tag == dwarf::DW_TAG_structure_type || Tag == dwarf::DW_TAG_union_type)
-      addTemplateParams(Buffer, CTy->getTemplateParams());
-
     // Add the type's non-standard calling convention.
     uint8_t CC = 0;
     if (CTy->isTypePassByValue())
@@ -1008,8 +940,10 @@ void DwarfUnit::constructTypeDIE(DIE &Buffer, const DICompositeType *CTy) {
       Tag == dwarf::DW_TAG_class_type || Tag == dwarf::DW_TAG_structure_type ||
       Tag == dwarf::DW_TAG_union_type) {
     // Add size if non-zero (derived types might be zero-sized.)
+    // Ignore the size if it's a non-enum forward decl.
     // TODO: Do we care about size for enum forward declarations?
-    if (Size)
+    if (Size &&
+        (!CTy->isForwardDecl() || Tag == dwarf::DW_TAG_enumeration_type))
       addUInt(Buffer, dwarf::DW_AT_byte_size, None, Size);
     else if (!CTy->isForwardDecl())
       // Add zero size if it is not a forward declaration.
@@ -1133,6 +1067,8 @@ DIE *DwarfUnit::getOrCreateModule(const DIModule *M) {
             getOrCreateSourceID(M->getFile()));
   if (M->getLineNo())
     addUInt(MDie, dwarf::DW_AT_decl_line, None, M->getLineNo());
+  if (M->getIsDecl())
+    addFlag(MDie, dwarf::DW_AT_declaration);
 
   return &MDie;
 }
@@ -1354,7 +1290,7 @@ void DwarfUnit::constructSubrangeDIE(DIE &Buffer, const DISubrange *SR,
   if (auto *CI = SR->getCount().dyn_cast<ConstantInt*>())
     Count = CI->getSExtValue();
 
-  auto addBoundTypeEntry = [&](dwarf::Attribute Attr,
+  auto AddBoundTypeEntry = [&](dwarf::Attribute Attr,
                                DISubrange::BoundType Bound) -> void {
     if (auto *BV = Bound.dyn_cast<DIVariable *>()) {
       if (auto *VarDIE = getDIE(BV))
@@ -1372,7 +1308,7 @@ void DwarfUnit::constructSubrangeDIE(DIE &Buffer, const DISubrange *SR,
     }
   };
 
-  addBoundTypeEntry(dwarf::DW_AT_lower_bound, SR->getLowerBound());
+  AddBoundTypeEntry(dwarf::DW_AT_lower_bound, SR->getLowerBound());
 
   if (auto *CV = SR->getCount().dyn_cast<DIVariable*>()) {
     if (auto *CountVarDIE = getDIE(CV))
@@ -1380,9 +1316,45 @@ void DwarfUnit::constructSubrangeDIE(DIE &Buffer, const DISubrange *SR,
   } else if (Count != -1)
     addUInt(DW_Subrange, dwarf::DW_AT_count, None, Count);
 
-  addBoundTypeEntry(dwarf::DW_AT_upper_bound, SR->getUpperBound());
+  AddBoundTypeEntry(dwarf::DW_AT_upper_bound, SR->getUpperBound());
+
+  AddBoundTypeEntry(dwarf::DW_AT_byte_stride, SR->getStride());
+}
+
+void DwarfUnit::constructGenericSubrangeDIE(DIE &Buffer,
+                                            const DIGenericSubrange *GSR,
+                                            DIE *IndexTy) {
+  DIE &DwGenericSubrange =
+      createAndAddDIE(dwarf::DW_TAG_generic_subrange, Buffer);
+  addDIEEntry(DwGenericSubrange, dwarf::DW_AT_type, *IndexTy);
+
+  int64_t DefaultLowerBound = getDefaultLowerBound();
+
+  auto AddBoundTypeEntry = [&](dwarf::Attribute Attr,
+                               DIGenericSubrange::BoundType Bound) -> void {
+    if (auto *BV = Bound.dyn_cast<DIVariable *>()) {
+      if (auto *VarDIE = getDIE(BV))
+        addDIEEntry(DwGenericSubrange, Attr, *VarDIE);
+    } else if (auto *BE = Bound.dyn_cast<DIExpression *>()) {
+      if (BE->isSignedConstant()) {
+        if (Attr != dwarf::DW_AT_lower_bound || DefaultLowerBound == -1 ||
+            static_cast<int64_t>(BE->getElement(1)) != DefaultLowerBound)
+          addSInt(DwGenericSubrange, Attr, dwarf::DW_FORM_sdata,
+                  BE->getElement(1));
+      } else {
+        DIELoc *Loc = new (DIEValueAllocator) DIELoc;
+        DIEDwarfExpression DwarfExpr(*Asm, getCU(), *Loc);
+        DwarfExpr.setMemoryLocationKind();
+        DwarfExpr.addExpression(BE);
+        addBlock(DwGenericSubrange, Attr, DwarfExpr.finalize());
+      }
+    }
+  };
 
-  addBoundTypeEntry(dwarf::DW_AT_byte_stride, SR->getStride());
+  AddBoundTypeEntry(dwarf::DW_AT_lower_bound, GSR->getLowerBound());
+  AddBoundTypeEntry(dwarf::DW_AT_count, GSR->getCount());
+  AddBoundTypeEntry(dwarf::DW_AT_upper_bound, GSR->getUpperBound());
+  AddBoundTypeEntry(dwarf::DW_AT_byte_stride, GSR->getStride());
 }
 
 DIE *DwarfUnit::getIndexTyDie() {
@@ -1417,8 +1389,10 @@ static bool hasVectorBeenPadded(const DICompositeType *CTy) {
          Elements[0]->getTag() == dwarf::DW_TAG_subrange_type &&
          "Invalid vector element array, expected one element of type subrange");
   const auto Subrange = cast<DISubrange>(Elements[0]);
-  const auto CI = Subrange->getCount().get<ConstantInt *>();
-  const int32_t NumVecElements = CI->getSExtValue();
+  const auto NumVecElements =
+      Subrange->getCount()
+          ? Subrange->getCount().get<ConstantInt *>()->getSExtValue()
+          : 0;
 
   // Ensure we found the element count and that the actual size is wide
   // enough to contain the requested size.
@@ -1445,6 +1419,39 @@ void DwarfUnit::constructArrayTypeDIE(DIE &Buffer, const DICompositeType *CTy) {
     addBlock(Buffer, dwarf::DW_AT_data_location, DwarfExpr.finalize());
   }
 
+  if (DIVariable *Var = CTy->getAssociated()) {
+    if (auto *VarDIE = getDIE(Var))
+      addDIEEntry(Buffer, dwarf::DW_AT_associated, *VarDIE);
+  } else if (DIExpression *Expr = CTy->getAssociatedExp()) {
+    DIELoc *Loc = new (DIEValueAllocator) DIELoc;
+    DIEDwarfExpression DwarfExpr(*Asm, getCU(), *Loc);
+    DwarfExpr.setMemoryLocationKind();
+    DwarfExpr.addExpression(Expr);
+    addBlock(Buffer, dwarf::DW_AT_associated, DwarfExpr.finalize());
+  }
+
+  if (DIVariable *Var = CTy->getAllocated()) {
+    if (auto *VarDIE = getDIE(Var))
+      addDIEEntry(Buffer, dwarf::DW_AT_allocated, *VarDIE);
+  } else if (DIExpression *Expr = CTy->getAllocatedExp()) {
+    DIELoc *Loc = new (DIEValueAllocator) DIELoc;
+    DIEDwarfExpression DwarfExpr(*Asm, getCU(), *Loc);
+    DwarfExpr.setMemoryLocationKind();
+    DwarfExpr.addExpression(Expr);
+    addBlock(Buffer, dwarf::DW_AT_allocated, DwarfExpr.finalize());
+  }
+
+  if (auto *RankConst = CTy->getRankConst()) {
+    addSInt(Buffer, dwarf::DW_AT_rank, dwarf::DW_FORM_sdata,
+            RankConst->getSExtValue());
+  } else if (auto *RankExpr = CTy->getRankExp()) {
+    DIELoc *Loc = new (DIEValueAllocator) DIELoc;
+    DIEDwarfExpression DwarfExpr(*Asm, getCU(), *Loc);
+    DwarfExpr.setMemoryLocationKind();
+    DwarfExpr.addExpression(RankExpr);
+    addBlock(Buffer, dwarf::DW_AT_rank, DwarfExpr.finalize());
+  }
+
   // Emit the element type.
   addType(Buffer, CTy->getBaseType());
 
@@ -1457,15 +1464,19 @@ void DwarfUnit::constructArrayTypeDIE(DIE &Buffer, const DICompositeType *CTy) {
   DINodeArray Elements = CTy->getElements();
   for (unsigned i = 0, N = Elements.size(); i < N; ++i) {
     // FIXME: Should this really be such a loose cast?
-    if (auto *Element = dyn_cast_or_null<DINode>(Elements[i]))
+    if (auto *Element = dyn_cast_or_null<DINode>(Elements[i])) {
       if (Element->getTag() == dwarf::DW_TAG_subrange_type)
         constructSubrangeDIE(Buffer, cast<DISubrange>(Element), IdxTy);
+      else if (Element->getTag() == dwarf::DW_TAG_generic_subrange)
+        constructGenericSubrangeDIE(Buffer, cast<DIGenericSubrange>(Element),
+                                    IdxTy);
+    }
   }
 }
 
 void DwarfUnit::constructEnumTypeDIE(DIE &Buffer, const DICompositeType *CTy) {
   const DIType *DTy = CTy->getBaseType();
-  bool IsUnsigned = DTy && isUnsignedDIType(DD, DTy);
+  bool IsUnsigned = DTy && DD->isUnsignedDIType(DTy);
   if (DTy) {
     if (DD->getDwarfVersion() >= 3)
       addType(Buffer, DTy);
@@ -1664,15 +1675,15 @@ DIE *DwarfUnit::getOrCreateStaticMemberDIE(const DIDerivedType *DT) {
 
 void DwarfUnit::emitCommonHeader(bool UseOffsets, dwarf::UnitType UT) {
   // Emit size of content not including length itself
-  Asm->OutStreamer->AddComment("Length of Unit");
   if (!DD->useSectionsAsReferences()) {
     StringRef Prefix = isDwoUnit() ? "debug_info_dwo_" : "debug_info_";
     MCSymbol *BeginLabel = Asm->createTempSymbol(Prefix + "start");
     EndLabel = Asm->createTempSymbol(Prefix + "end");
-    Asm->emitLabelDifference(EndLabel, BeginLabel, 4);
+    Asm->emitDwarfUnitLength(EndLabel, BeginLabel, "Length of Unit");
     Asm->OutStreamer->emitLabel(BeginLabel);
   } else
-    Asm->emitInt32(getHeaderSize() + getUnitDie().getSize());
+    Asm->emitDwarfUnitLength(getHeaderSize() + getUnitDie().getSize(),
+                             "Length of Unit");
 
   Asm->OutStreamer->AddComment("DWARF version number");
   unsigned Version = DD->getDwarfVersion();
@@ -1692,7 +1703,7 @@ void DwarfUnit::emitCommonHeader(bool UseOffsets, dwarf::UnitType UT) {
   Asm->OutStreamer->AddComment("Offset Into Abbrev. Section");
   const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
   if (UseOffsets)
-    Asm->emitInt32(0);
+    Asm->emitDwarfLengthOrOffset(0);
   else
     Asm->emitDwarfSymbolReference(
         TLOF.getDwarfAbbrevSection()->getBeginSymbol(), false);
@@ -1711,16 +1722,14 @@ void DwarfTypeUnit::emitHeader(bool UseOffsets) {
   Asm->OutStreamer->emitIntValue(TypeSignature, sizeof(TypeSignature));
   Asm->OutStreamer->AddComment("Type DIE Offset");
   // In a skeleton type unit there is no type DIE so emit a zero offset.
-  Asm->OutStreamer->emitIntValue(Ty ? Ty->getOffset() : 0,
-                                 sizeof(Ty->getOffset()));
+  Asm->emitDwarfLengthOrOffset(Ty ? Ty->getOffset() : 0);
 }
 
 DIE::value_iterator
 DwarfUnit::addSectionDelta(DIE &Die, dwarf::Attribute Attribute,
                            const MCSymbol *Hi, const MCSymbol *Lo) {
   return Die.addValue(DIEValueAllocator, Attribute,
-                      DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
-                                                 : dwarf::DW_FORM_data4,
+                      DD->getDwarfSectionOffsetForm(),
                       new (DIEValueAllocator) DIEDelta(Hi, Lo));
 }
 
@@ -1728,10 +1737,7 @@ DIE::value_iterator
 DwarfUnit::addSectionLabel(DIE &Die, dwarf::Attribute Attribute,
                            const MCSymbol *Label, const MCSymbol *Sec) {
   if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
-    return addLabel(Die, Attribute,
-                    DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
-                                               : dwarf::DW_FORM_data4,
-                    Label);
+    return addLabel(Die, Attribute, DD->getDwarfSectionOffsetForm(), Label);
   return addSectionDelta(Die, Attribute, Label, Sec);
 }