vendor/llvm/llvm-trunk-r366426

27 files changed, 850 insertions, 544 deletions

diff --git a/lib/DebugInfo/DWARF/DWARFAbbreviationDeclaration.cpp b/lib/DebugInfo/DWARF/DWARFAbbreviationDeclaration.cpp
index f49ab40fad9a..f4dd79937608 100644
--- a/lib/DebugInfo/DWARF/DWARFAbbreviationDeclaration.cpp
+++ b/lib/DebugInfo/DWARF/DWARFAbbreviationDeclaration.cpp
@@ -1,9 +1,8 @@
 //===- DWARFAbbreviationDeclaration.cpp -----------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
@@ -164,11 +163,11 @@ Optional<DWARFFormValue> DWARFAbbreviationDeclaration::getAttributeValue(
   for (const auto &Spec : AttributeSpecs) {
     if (*MatchAttrIndex == AttrIndex) {
       // We have arrived at the attribute to extract, extract if from Offset.
+      if (Spec.isImplicitConst())
+        return DWARFFormValue::createFromSValue(Spec.Form,
+                                                Spec.getImplicitConstValue());
+
       DWARFFormValue FormValue(Spec.Form);
-      if (Spec.isImplicitConst()) {
-        FormValue.setSValue(Spec.getImplicitConstValue());
-        return FormValue;
-      }
       if (FormValue.extractValue(DebugInfoData, &Offset, U.getFormParams(), &U))
         return FormValue;
     }
diff --git a/lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp b/lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp
index 54daf34ff253..0721efb40f6a 100644
--- a/lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp
+++ b/lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp
@@ -1,9 +1,8 @@
 //===- DWARFAcceleratorTable.cpp ------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
@@ -42,7 +41,7 @@ static Atom formatAtom(unsigned Atom) { return {Atom}; }
 
 DWARFAcceleratorTable::~DWARFAcceleratorTable() = default;
 
-llvm::Error AppleAcceleratorTable::extract() {
+Error AppleAcceleratorTable::extract() {
   uint32_t Offset = 0;
 
   // Check that we can at least read the header.
@@ -377,7 +376,7 @@ void DWARFDebugNames::Header::dump(ScopedPrinter &W) const {
   W.startLine() << "Augmentation: '" << AugmentationString << "'\n";
 }
 
-llvm::Error DWARFDebugNames::Header::extract(const DWARFDataExtractor &AS,
+Error DWARFDebugNames::Header::extract(const DWARFDataExtractor &AS,
                                              uint32_t *Offset) {
   // Check that we can read the fixed-size part.
   if (!AS.isValidOffset(*Offset + sizeof(HeaderPOD) - 1))
@@ -519,6 +518,7 @@ Error DWARFDebugNames::NameIndex::extract() {
                                "Duplicate abbreviation code.");
   }
 }
+
 DWARFDebugNames::Entry::Entry(const NameIndex &NameIdx, const Abbrev &Abbr)
     : NameIdx(&NameIdx), Abbr(&Abbr) {
   // This merely creates form values. It is up to the caller
@@ -585,13 +585,14 @@ uint32_t DWARFDebugNames::NameIndex::getCUOffset(uint32_t CU) const {
 
 uint32_t DWARFDebugNames::NameIndex::getLocalTUOffset(uint32_t TU) const {
   assert(TU < Hdr.LocalTypeUnitCount);
-  uint32_t Offset = CUsBase + Hdr.CompUnitCount * 4;
+  uint32_t Offset = CUsBase + 4 * (Hdr.CompUnitCount + TU);
   return Section.AccelSection.getRelocatedValue(4, &Offset);
 }
 
 uint64_t DWARFDebugNames::NameIndex::getForeignTUSignature(uint32_t TU) const {
   assert(TU < Hdr.ForeignTypeUnitCount);
-  uint32_t Offset = CUsBase + (Hdr.CompUnitCount + Hdr.LocalTypeUnitCount) * 4;
+  uint32_t Offset =
+      CUsBase + 4 * (Hdr.CompUnitCount + Hdr.LocalTypeUnitCount) + 8 * TU;
   return Section.AccelSection.getU64(&Offset);
 }
 
@@ -754,11 +755,11 @@ LLVM_DUMP_METHOD void DWARFDebugNames::NameIndex::dump(ScopedPrinter &W) const {
     dumpName(W, NTE, None);
 }
 
-llvm::Error DWARFDebugNames::extract() {
+Error DWARFDebugNames::extract() {
   uint32_t Offset = 0;
   while (AccelSection.isValidOffset(Offset)) {
     NameIndex Next(*this, Offset);
-    if (llvm::Error E = Next.extract())
+    if (Error E = Next.extract())
       return E;
     Offset = Next.getNextUnitOffset();
     NameIndices.push_back(std::move(Next));
diff --git a/lib/DebugInfo/DWARF/DWARFAddressRange.cpp b/lib/DebugInfo/DWARF/DWARFAddressRange.cpp
index 86c8d19c02f4..ef6da08d34aa 100644
--- a/lib/DebugInfo/DWARF/DWARFAddressRange.cpp
+++ b/lib/DebugInfo/DWARF/DWARFAddressRange.cpp
@@ -1,9 +1,8 @@
 //===- DWARFDebugAranges.cpp ------------------------------------*- C++ -*-===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
diff --git a/lib/DebugInfo/DWARF/DWARFCompileUnit.cpp b/lib/DebugInfo/DWARF/DWARFCompileUnit.cpp
index 00a23b3898fa..74cce42466dd 100644
--- a/lib/DebugInfo/DWARF/DWARFCompileUnit.cpp
+++ b/lib/DebugInfo/DWARF/DWARFCompileUnit.cpp
@@ -1,9 +1,8 @@
 //===-- DWARFCompileUnit.cpp ----------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
diff --git a/lib/DebugInfo/DWARF/DWARFContext.cpp b/lib/DebugInfo/DWARF/DWARFContext.cpp
index e6620ee3dd1d..5ede9bf59619 100644
--- a/lib/DebugInfo/DWARF/DWARFContext.cpp
+++ b/lib/DebugInfo/DWARF/DWARFContext.cpp
@@ -1,9 +1,8 @@
 //===- DWARFContext.cpp ---------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
@@ -37,11 +36,12 @@
 #include "llvm/Object/Decompressor.h"
 #include "llvm/Object/MachO.h"
 #include "llvm/Object/ObjectFile.h"
-#include "llvm/Object/RelocVisitor.h"
+#include "llvm/Object/RelocationResolver.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/DataExtractor.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/Format.h"
+#include "llvm/Support/LEB128.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/TargetRegistry.h"
@@ -102,7 +102,8 @@ static ContributionCollection
 collectContributionData(DWARFContext::unit_iterator_range Units) {
   ContributionCollection Contributions;
   for (const auto &U : Units)
-    Contributions.push_back(U->getStringOffsetsTableContribution());
+    if (const auto &C = U->getStringOffsetsTableContribution())
+      Contributions.push_back(C);
   // Sort the contributions so that any invalid ones are placed at
   // the start of the contributions vector. This way they are reported
   // first.
@@ -158,9 +159,9 @@ static void dumpDWARFv5StringOffsetsSection(
 
     // Detect overlapping contributions.
     if (Offset > ContributionHeader) {
-      OS << "error: overlapping contributions to string offsets table in "
-            "section ."
-         << SectionName << ".\n";
+      WithColor::error()
+          << "overlapping contributions to string offsets table in section ."
+          << SectionName << ".\n";
       return;
     }
     // Report a gap in the table.
@@ -269,11 +270,11 @@ static void dumpAddrSection(raw_ostream &OS, DWARFDataExtractor &AddrData,
 }
 
 // Dump the .debug_rnglists or .debug_rnglists.dwo section (DWARF v5).
-static void
-dumpRnglistsSection(raw_ostream &OS, DWARFDataExtractor &rnglistData,
-                    llvm::function_ref<Optional<SectionedAddress>(uint32_t)>
-                        LookupPooledAddress,
-                    DIDumpOptions DumpOpts) {
+static void dumpRnglistsSection(
+    raw_ostream &OS, DWARFDataExtractor &rnglistData,
+    llvm::function_ref<Optional<object::SectionedAddress>(uint32_t)>
+        LookupPooledAddress,
+    DIDumpOptions DumpOpts) {
   uint32_t Offset = 0;
   while (rnglistData.isValidOffset(Offset)) {
     llvm::DWARFDebugRnglistTable Rnglists;
@@ -926,6 +927,9 @@ DWARFContext::DIEsForAddress DWARFContext::getDIEsForAddress(uint64_t Address) {
     DWARFDie DIE = Worklist.back();
     Worklist.pop_back();
 
+    if (!DIE.isValid())
+      continue;
+
     if (DIE.getTag() == DW_TAG_lexical_block &&
         DIE.addressRangeContainsAddress(Address)) {
       Result.BlockDIE = DIE;
@@ -939,6 +943,8 @@ DWARFContext::DIEsForAddress DWARFContext::getDIEsForAddress(uint64_t Address) {
   return Result;
 }
 
+/// TODO: change input parameter from "uint64_t Address"
+///       into "SectionedAddress Address"
 static bool getFunctionNameAndStartLineForAddress(DWARFCompileUnit *CU,
                                                   uint64_t Address,
                                                   FunctionNameKind Kind,
@@ -967,36 +973,155 @@ static bool getFunctionNameAndStartLineForAddress(DWARFCompileUnit *CU,
   return FoundResult;
 }
 
-DILineInfo DWARFContext::getLineInfoForAddress(uint64_t Address,
+static Optional<uint64_t> getTypeSize(DWARFDie Type, uint64_t PointerSize) {
+  if (auto SizeAttr = Type.find(DW_AT_byte_size))
+    if (Optional<uint64_t> Size = SizeAttr->getAsUnsignedConstant())
+      return Size;
+
+  switch (Type.getTag()) {
+  case DW_TAG_pointer_type:
+  case DW_TAG_reference_type:
+  case DW_TAG_rvalue_reference_type:
+    return PointerSize;
+  case DW_TAG_ptr_to_member_type: {
+    if (DWARFDie BaseType = Type.getAttributeValueAsReferencedDie(DW_AT_type))
+      if (BaseType.getTag() == DW_TAG_subroutine_type)
+        return 2 * PointerSize;
+    return PointerSize;
+  }
+  case DW_TAG_const_type:
+  case DW_TAG_volatile_type:
+  case DW_TAG_restrict_type:
+  case DW_TAG_typedef: {
+    if (DWARFDie BaseType = Type.getAttributeValueAsReferencedDie(DW_AT_type))
+      return getTypeSize(BaseType, PointerSize);
+    break;
+  }
+  case DW_TAG_array_type: {
+    DWARFDie BaseType = Type.getAttributeValueAsReferencedDie(DW_AT_type);
+    if (!BaseType)
+      return Optional<uint64_t>();
+    Optional<uint64_t> BaseSize = getTypeSize(BaseType, PointerSize);
+    if (!BaseSize)
+      return Optional<uint64_t>();
+    uint64_t Size = *BaseSize;
+    for (DWARFDie Child : Type) {
+      if (Child.getTag() != DW_TAG_subrange_type)
+        continue;
+
+      if (auto ElemCountAttr = Child.find(DW_AT_count))
+        if (Optional<uint64_t> ElemCount =
+                ElemCountAttr->getAsUnsignedConstant())
+          Size *= *ElemCount;
+      if (auto UpperBoundAttr = Child.find(DW_AT_upper_bound))
+        if (Optional<int64_t> UpperBound =
+                UpperBoundAttr->getAsSignedConstant()) {
+          int64_t LowerBound = 0;
+          if (auto LowerBoundAttr = Child.find(DW_AT_lower_bound))
+            LowerBound = LowerBoundAttr->getAsSignedConstant().getValueOr(0);
+          Size *= *UpperBound - LowerBound + 1;
+        }
+    }
+    return Size;
+  }
+  default:
+    break;
+  }
+  return Optional<uint64_t>();
+}
+
+void DWARFContext::addLocalsForDie(DWARFCompileUnit *CU, DWARFDie Subprogram,
+                                   DWARFDie Die, std::vector<DILocal> &Result) {
+  if (Die.getTag() == DW_TAG_variable ||
+      Die.getTag() == DW_TAG_formal_parameter) {
+    DILocal Local;
+    if (auto NameAttr = Subprogram.find(DW_AT_name))
+      if (Optional<const char *> Name = NameAttr->getAsCString())
+        Local.FunctionName = *Name;
+    if (auto LocationAttr = Die.find(DW_AT_location))
+      if (Optional<ArrayRef<uint8_t>> Location = LocationAttr->getAsBlock())
+        if (!Location->empty() && (*Location)[0] == DW_OP_fbreg)
+          Local.FrameOffset =
+              decodeSLEB128(Location->data() + 1, nullptr, Location->end());
+    if (auto TagOffsetAttr = Die.find(DW_AT_LLVM_tag_offset))
+      Local.TagOffset = TagOffsetAttr->getAsUnsignedConstant();
+
+    if (auto Origin =
+            Die.getAttributeValueAsReferencedDie(DW_AT_abstract_origin))
+      Die = Origin;
+    if (auto NameAttr = Die.find(DW_AT_name))
+      if (Optional<const char *> Name = NameAttr->getAsCString())
+        Local.Name = *Name;
+    if (auto Type = Die.getAttributeValueAsReferencedDie(DW_AT_type))
+      Local.Size = getTypeSize(Type, getCUAddrSize());
+    if (auto DeclFileAttr = Die.find(DW_AT_decl_file)) {
+      if (const auto *LT = CU->getContext().getLineTableForUnit(CU))
+        LT->getFileNameByIndex(
+            DeclFileAttr->getAsUnsignedConstant().getValue(),
+            CU->getCompilationDir(),
+            DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath,
+            Local.DeclFile);
+    }
+    if (auto DeclLineAttr = Die.find(DW_AT_decl_line))
+      Local.DeclLine = DeclLineAttr->getAsUnsignedConstant().getValue();
+
+    Result.push_back(Local);
+    return;
+  }
+
+  if (Die.getTag() == DW_TAG_inlined_subroutine)
+    if (auto Origin =
+            Die.getAttributeValueAsReferencedDie(DW_AT_abstract_origin))
+      Subprogram = Origin;
+
+  for (auto Child : Die)
+    addLocalsForDie(CU, Subprogram, Child, Result);
+}
+
+std::vector<DILocal>
+DWARFContext::getLocalsForAddress(object::SectionedAddress Address) {
+  std::vector<DILocal> Result;
+  DWARFCompileUnit *CU = getCompileUnitForAddress(Address.Address);
+  if (!CU)
+    return Result;
+
+  DWARFDie Subprogram = CU->getSubroutineForAddress(Address.Address);
+  if (Subprogram.isValid())
+    addLocalsForDie(CU, Subprogram, Subprogram, Result);
+  return Result;
+}
+
+DILineInfo DWARFContext::getLineInfoForAddress(object::SectionedAddress Address,
                                                DILineInfoSpecifier Spec) {
   DILineInfo Result;
 
-  DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
+  DWARFCompileUnit *CU = getCompileUnitForAddress(Address.Address);
   if (!CU)
     return Result;
-  getFunctionNameAndStartLineForAddress(CU, Address, Spec.FNKind,
-                                        Result.FunctionName,
-                                        Result.StartLine);
+
+  getFunctionNameAndStartLineForAddress(CU, Address.Address, Spec.FNKind,
+                                        Result.FunctionName, Result.StartLine);
   if (Spec.FLIKind != FileLineInfoKind::None) {
-    if (const DWARFLineTable *LineTable = getLineTableForUnit(CU))
-      LineTable->getFileLineInfoForAddress(Address, CU->getCompilationDir(),
-                                           Spec.FLIKind, Result);
+    if (const DWARFLineTable *LineTable = getLineTableForUnit(CU)) {
+      LineTable->getFileLineInfoForAddress(
+          {Address.Address, Address.SectionIndex}, CU->getCompilationDir(),
+          Spec.FLIKind, Result);
+    }
   }
   return Result;
 }
 
-DILineInfoTable
-DWARFContext::getLineInfoForAddressRange(uint64_t Address, uint64_t Size,
-                                         DILineInfoSpecifier Spec) {
+DILineInfoTable DWARFContext::getLineInfoForAddressRange(
+    object::SectionedAddress Address, uint64_t Size, DILineInfoSpecifier Spec) {
   DILineInfoTable  Lines;
-  DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
+  DWARFCompileUnit *CU = getCompileUnitForAddress(Address.Address);
   if (!CU)
     return Lines;
 
   std::string FunctionName = "<invalid>";
   uint32_t StartLine = 0;
-  getFunctionNameAndStartLineForAddress(CU, Address, Spec.FNKind, FunctionName,
-                                        StartLine);
+  getFunctionNameAndStartLineForAddress(CU, Address.Address, Spec.FNKind,
+                                        FunctionName, StartLine);
 
   // If the Specifier says we don't need FileLineInfo, just
   // return the top-most function at the starting address.
@@ -1004,7 +1129,7 @@ DWARFContext::getLineInfoForAddressRange(uint64_t Address, uint64_t Size,
     DILineInfo Result;
     Result.FunctionName = FunctionName;
     Result.StartLine = StartLine;
-    Lines.push_back(std::make_pair(Address, Result));
+    Lines.push_back(std::make_pair(Address.Address, Result));
     return Lines;
   }
 
@@ -1012,8 +1137,10 @@ DWARFContext::getLineInfoForAddressRange(uint64_t Address, uint64_t Size,
 
   // Get the index of row we're looking for in the line table.
   std::vector<uint32_t> RowVector;
-  if (!LineTable->lookupAddressRange(Address, Size, RowVector))
+  if (!LineTable->lookupAddressRange({Address.Address, Address.SectionIndex},
+                                     Size, RowVector)) {
     return Lines;
+  }
 
   for (uint32_t RowIndex : RowVector) {
     // Take file number and line/column from the row.
@@ -1025,33 +1152,33 @@ DWARFContext::getLineInfoForAddressRange(uint64_t Address, uint64_t Size,
     Result.Line = Row.Line;
     Result.Column = Row.Column;
     Result.StartLine = StartLine;
-    Lines.push_back(std::make_pair(Row.Address, Result));
+    Lines.push_back(std::make_pair(Row.Address.Address, Result));
   }
 
   return Lines;
 }
 
 DIInliningInfo
-DWARFContext::getInliningInfoForAddress(uint64_t Address,
+DWARFContext::getInliningInfoForAddress(object::SectionedAddress Address,
                                         DILineInfoSpecifier Spec) {
   DIInliningInfo InliningInfo;
 
-  DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
+  DWARFCompileUnit *CU = getCompileUnitForAddress(Address.Address);
   if (!CU)
     return InliningInfo;
 
   const DWARFLineTable *LineTable = nullptr;
   SmallVector<DWARFDie, 4> InlinedChain;
-  CU->getInlinedChainForAddress(Address, InlinedChain);
+  CU->getInlinedChainForAddress(Address.Address, InlinedChain);
   if (InlinedChain.size() == 0) {
     // If there is no DIE for address (e.g. it is in unavailable .dwo file),
     // try to at least get file/line info from symbol table.
     if (Spec.FLIKind != FileLineInfoKind::None) {
       DILineInfo Frame;
       LineTable = getLineTableForUnit(CU);
-      if (LineTable &&
-          LineTable->getFileLineInfoForAddress(Address, CU->getCompilationDir(),
-                                               Spec.FLIKind, Frame))
+      if (LineTable && LineTable->getFileLineInfoForAddress(
+                           {Address.Address, Address.SectionIndex},
+                           CU->getCompilationDir(), Spec.FLIKind, Frame))
         InliningInfo.addFrame(Frame);
     }
     return InliningInfo;
@@ -1073,8 +1200,9 @@ DWARFContext::getInliningInfoForAddress(uint64_t Address,
         LineTable = getLineTableForUnit(CU);
         // For the topmost routine, get file/line info from line table.
         if (LineTable)
-          LineTable->getFileLineInfoForAddress(Address, CU->getCompilationDir(),
-                                               Spec.FLIKind, Frame);
+          LineTable->getFileLineInfoForAddress(
+              {Address.Address, Address.SectionIndex}, CU->getCompilationDir(),
+              Spec.FLIKind, Frame);
       } else {
         // Otherwise, use call file, call line and call column from
         // previous DIE in inlined chain.
@@ -1402,8 +1530,14 @@ public:
       // Try to obtain an already relocated version of this section.
       // Else use the unrelocated section from the object file. We'll have to
       // apply relocations ourselves later.
-      if (!L || !L->getLoadedSectionContents(*RelocatedSection, Data))
-        Section.getContents(Data);
+      if (!L || !L->getLoadedSectionContents(*RelocatedSection, Data)) {
+        Expected<StringRef> E = Section.getContents();
+        if (E)
+          Data = *E;
+        else
+          // maybeDecompress below will error.
+          consumeError(E.takeError());
+      }
 
       if (auto Err = maybeDecompress(Section, Name, Data)) {
         ErrorPolicy EP = HandleError(createError(
@@ -1495,6 +1629,9 @@ public:
 
       // Symbol to [address, section index] cache mapping.
       std::map<SymbolRef, SymInfo> AddrCache;
+      bool (*Supports)(uint64_t);
+      RelocationResolver Resolver;
+      std::tie(Supports, Resolver) = getRelocationResolver(Obj);
       for (const RelocationRef &Reloc : Section.relocations()) {
         // FIXME: it's not clear how to correctly handle scattered
         // relocations.
@@ -1509,9 +1646,31 @@ public:
           continue;
         }
 
-        object::RelocVisitor V(Obj);
-        uint64_t Val = V.visit(Reloc.getType(), Reloc, SymInfoOrErr->Address);
-        if (V.error()) {
+        // Check if Resolver can handle this relocation type early so as not to
+        // handle invalid cases in DWARFDataExtractor.
+        //
+        // TODO Don't store Resolver in every RelocAddrEntry.
+        if (Supports && Supports(Reloc.getType())) {
+          auto I = Map->try_emplace(
+              Reloc.getOffset(),
+              RelocAddrEntry{SymInfoOrErr->SectionIndex, Reloc,
+                             SymInfoOrErr->Address,
+                             Optional<object::RelocationRef>(), 0, Resolver});
+          // If we didn't successfully insert that's because we already had a
+          // relocation for that offset. Store it as a second relocation in the
+          // same RelocAddrEntry instead.
+          if (!I.second) {
+            RelocAddrEntry &entry = I.first->getSecond();
+            if (entry.Reloc2) {
+              ErrorPolicy EP = HandleError(createError(
+                  "At most two relocations per offset are supported"));
+              if (EP == ErrorPolicy::Halt)
+                return;
+            }
+            entry.Reloc2 = Reloc;
+            entry.SymbolValue2 = SymInfoOrErr->Address;
+          }
+        } else {
           SmallString<32> Type;
           Reloc.getTypeName(Type);
           ErrorPolicy EP = HandleError(
@@ -1519,10 +1678,7 @@ public:
                           errorCodeToError(object_error::parse_failed)));
           if (EP == ErrorPolicy::Halt)
             return;
-          continue;
         }
-        RelocAddrEntry Rel = {SymInfoOrErr->SectionIndex, Val};
-        Map->insert({Reloc.getOffset(), Rel});
       }
     }
 
diff --git a/lib/DebugInfo/DWARF/DWARFDataExtractor.cpp b/lib/DebugInfo/DWARF/DWARFDataExtractor.cpp
index 03e317461396..b9adf8cb1d99 100644
--- a/lib/DebugInfo/DWARF/DWARFDataExtractor.cpp
+++ b/lib/DebugInfo/DWARF/DWARFDataExtractor.cpp
@@ -1,9 +1,8 @@
 //===- DWARFDataExtractor.cpp ---------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
@@ -16,15 +15,19 @@ using namespace llvm;
 uint64_t DWARFDataExtractor::getRelocatedValue(uint32_t Size, uint32_t *Off,
                                                uint64_t *SecNdx) const {
   if (SecNdx)
-    *SecNdx = -1ULL;
+    *SecNdx = object::SectionedAddress::UndefSection;
   if (!Section)
     return getUnsigned(Off, Size);
-  Optional<RelocAddrEntry> Rel = Obj->find(*Section, *Off);
-  if (!Rel)
-    return getUnsigned(Off, Size);
+  Optional<RelocAddrEntry> E = Obj->find(*Section, *Off);
+  uint64_t A = getUnsigned(Off, Size);
+  if (!E)
+    return A;
   if (SecNdx)
-    *SecNdx = Rel->SectionIndex;
-  return getUnsigned(Off, Size) + Rel->Value;
+    *SecNdx = E->SectionIndex;
+  uint64_t R = E->Resolver(E->Reloc, E->SymbolValue, A);
+  if (E->Reloc2)
+    R = E->Resolver(*E->Reloc2, E->SymbolValue2, R);
+  return R;
 }
 
 Optional<uint64_t>
diff --git a/lib/DebugInfo/DWARF/DWARFDebugAbbrev.cpp b/lib/DebugInfo/DWARF/DWARFDebugAbbrev.cpp
index 4830c36a8ee7..31b324e5eb27 100644
--- a/lib/DebugInfo/DWARF/DWARFDebugAbbrev.cpp
+++ b/lib/DebugInfo/DWARF/DWARFDebugAbbrev.cpp
@@ -1,9 +1,8 @@
 //===- DWARFDebugAbbrev.cpp -----------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
@@ -84,12 +83,12 @@ void DWARFDebugAbbrev::parse() const {
   if (!Data)
     return;
   uint32_t Offset = 0;
-  DWARFAbbreviationDeclarationSet AbbrDecls;
   auto I = AbbrDeclSets.begin();
   while (Data->isValidOffset(Offset)) {
     while (I != AbbrDeclSets.end() && I->first < Offset)
       ++I;
     uint32_t CUAbbrOffset = Offset;
+    DWARFAbbreviationDeclarationSet AbbrDecls;
     if (!AbbrDecls.extract(*Data, &Offset))
       break;
     AbbrDeclSets.insert(I, std::make_pair(CUAbbrOffset, std::move(AbbrDecls)));
diff --git a/lib/DebugInfo/DWARF/DWARFDebugAddr.cpp b/lib/DebugInfo/DWARF/DWARFDebugAddr.cpp
index 22759bfac26c..58626539bba4 100644
--- a/lib/DebugInfo/DWARF/DWARFDebugAddr.cpp
+++ b/lib/DebugInfo/DWARF/DWARFDebugAddr.cpp
@@ -1,9 +1,8 @@
 //===- DWARFDebugAddr.cpp -------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
@@ -148,28 +147,13 @@ void DWARFDebugAddrTable::dump(raw_ostream &OS, DIDumpOptions DumpOpts) const {
                HeaderData.Length, HeaderData.Version, HeaderData.AddrSize,
                HeaderData.SegSize);
 
-  static const char *Fmt32 = "0x%8.8" PRIx64;
-  static const char *Fmt64 = "0x%16.16" PRIx64;
-  std::string AddrFmt = "\n";
-  std::string AddrFmtVerbose = " => ";
-  if (HeaderData.AddrSize == 4) {
-    AddrFmt.append(Fmt32);
-    AddrFmtVerbose.append(Fmt32);
-  }
-  else {
-    AddrFmt.append(Fmt64);
-    AddrFmtVerbose.append(Fmt64);
-  }
-
   if (Addrs.size() > 0) {
-    OS << "Addrs: [";
-    for (uint64_t Addr : Addrs) {
-      OS << format(AddrFmt.c_str(), Addr);
-      if (DumpOpts.Verbose)
-        OS << format(AddrFmtVerbose.c_str(),
-                     Addr + HeaderOffset + sizeof(HeaderData));
-    }
-    OS << "\n]\n";
+    const char *AddrFmt = (HeaderData.AddrSize == 4) ? "0x%8.8" PRIx64 "\n"
+                                                     : "0x%16.16" PRIx64 "\n";
+    OS << "Addrs: [\n";
+    for (uint64_t Addr : Addrs)
+      OS << format(AddrFmt, Addr);
+    OS << "]\n";
   }
 }
 
diff --git a/lib/DebugInfo/DWARF/DWARFDebugArangeSet.cpp b/lib/DebugInfo/DWARF/DWARFDebugArangeSet.cpp
index b9ef6905912a..6551b61accb8 100644
--- a/lib/DebugInfo/DWARF/DWARFDebugArangeSet.cpp
+++ b/lib/DebugInfo/DWARF/DWARFDebugArangeSet.cpp
@@ -1,9 +1,8 @@
 //===- DWARFDebugArangeSet.cpp --------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
diff --git a/lib/DebugInfo/DWARF/DWARFDebugAranges.cpp b/lib/DebugInfo/DWARF/DWARFDebugAranges.cpp
index e8c5dec821b4..6460c9feeab8 100644
--- a/lib/DebugInfo/DWARF/DWARFDebugAranges.cpp
+++ b/lib/DebugInfo/DWARF/DWARFDebugAranges.cpp
@@ -1,9 +1,8 @@
 //===- DWARFDebugAranges.cpp ----------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
@@ -115,20 +114,9 @@ void DWARFDebugAranges::construct() {
 }
 
 uint32_t DWARFDebugAranges::findAddress(uint64_t Address) const {
-  if (!Aranges.empty()) {
-    Range range(Address);
-    RangeCollIterator begin = Aranges.begin();
-    RangeCollIterator end = Aranges.end();
-    RangeCollIterator pos =
-        std::lower_bound(begin, end, range);
-
-    if (pos != end && pos->containsAddress(Address)) {
-      return pos->CUOffset;
-    } else if (pos != begin) {
-      --pos;
-      if (pos->containsAddress(Address))
-        return pos->CUOffset;
-    }
-  }
+  RangeCollIterator It =
+      partition_point(Aranges, [=](Range R) { return R.HighPC() <= Address; });
+  if (It != Aranges.end() && It->LowPC <= Address)
+    return It->CUOffset;
   return -1U;
 }
diff --git a/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp b/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp
index ba55ffc28174..b3f23366f2a2 100644
--- a/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp
+++ b/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp
@@ -1,9 +1,8 @@
 //===- DWARFDebugFrame.h - Parsing of .debug_frame ------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
@@ -267,7 +266,7 @@ void CFIProgram::printOperand(raw_ostream &OS, const MCRegisterInfo *MRI,
   case OT_Expression:
     assert(Instr.Expression && "missing DWARFExpression object");
     OS << " ";
-    Instr.Expression->print(OS, MRI, IsEH);
+    Instr.Expression->print(OS, MRI, nullptr, IsEH);
     break;
   }
 }
@@ -301,7 +300,7 @@ void CIE::dump(raw_ostream &OS, const MCRegisterInfo *MRI, bool IsEH) const {
   OS << format("  Data alignment factor: %d\n", (int32_t)DataAlignmentFactor);
   OS << format("  Return address column: %d\n", (int32_t)ReturnAddressRegister);
   if (Personality)
-    OS << format("  Personality Address: %08x\n", *Personality);
+    OS << format("  Personality Address: %016" PRIx64 "\n", *Personality);
   if (!AugmentationData.empty()) {
     OS << "  Augmentation data:    ";
     for (uint8_t Byte : AugmentationData)
@@ -320,7 +319,7 @@ void FDE::dump(raw_ostream &OS, const MCRegisterInfo *MRI, bool IsEH) const {
                (uint32_t)InitialLocation,
                (uint32_t)InitialLocation + (uint32_t)AddressRange);
   if (LSDAAddress)
-    OS << format("  LSDA Address: %08x\n", *LSDAAddress);
+    OS << format("  LSDA Address: %016" PRIx64 "\n", *LSDAAddress);
   CFIs.dump(OS, MRI, IsEH);
   OS << "\n";
 }
@@ -533,10 +532,9 @@ void DWARFDebugFrame::parse(DWARFDataExtractor Data) {
 }
 
 FrameEntry *DWARFDebugFrame::getEntryAtOffset(uint64_t Offset) const {
-  auto It =
-      std::lower_bound(Entries.begin(), Entries.end(), Offset,
-                       [](const std::unique_ptr<FrameEntry> &E,
-                          uint64_t Offset) { return E->getOffset() < Offset; });
+  auto It = partition_point(Entries, [=](const std::unique_ptr<FrameEntry> &E) {
+    return E->getOffset() < Offset;
+  });
   if (It != Entries.end() && (*It)->getOffset() == Offset)
     return It->get();
   return nullptr;
diff --git a/lib/DebugInfo/DWARF/DWARFDebugInfoEntry.cpp b/lib/DebugInfo/DWARF/DWARFDebugInfoEntry.cpp
index 976bc4651ae6..d8a755e90df4 100644
--- a/lib/DebugInfo/DWARF/DWARFDebugInfoEntry.cpp
+++ b/lib/DebugInfo/DWARF/DWARFDebugInfoEntry.cpp
@@ -1,9 +1,8 @@
 //===- DWARFDebugInfoEntry.cpp --------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
diff --git a/lib/DebugInfo/DWARF/DWARFDebugLine.cpp b/lib/DebugInfo/DWARF/DWARFDebugLine.cpp
index 1d621ff244f3..a1cb1e8582ed 100644
--- a/lib/DebugInfo/DWARF/DWARFDebugLine.cpp
+++ b/lib/DebugInfo/DWARF/DWARFDebugLine.cpp
@@ -1,9 +1,8 @@
 //===- DWARFDebugLine.cpp -------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
@@ -67,6 +66,26 @@ void DWARFDebugLine::ContentTypeTracker::trackContentType(
 
 DWARFDebugLine::Prologue::Prologue() { clear(); }
 
+bool DWARFDebugLine::Prologue::hasFileAtIndex(uint64_t FileIndex) const {
+  uint16_t DwarfVersion = getVersion();
+  assert(DwarfVersion != 0 &&
+         "line table prologue has no dwarf version information");
+  if (DwarfVersion >= 5)
+    return FileIndex < FileNames.size();
+  return FileIndex != 0 && FileIndex <= FileNames.size();
+}
+
+const llvm::DWARFDebugLine::FileNameEntry &
+DWARFDebugLine::Prologue::getFileNameEntry(uint64_t Index) const {
+  uint16_t DwarfVersion = getVersion();
+  assert(DwarfVersion != 0 &&
+         "line table prologue has no dwarf version information");
+  // In DWARF v5 the file names are 0-indexed.
+  if (DwarfVersion >= 5)
+    return FileNames[Index];
+  return FileNames[Index - 1];
+}
+
 void DWARFDebugLine::Prologue::clear() {
   TotalLength = PrologueLength = 0;
   SegSelectorSize = 0;
@@ -145,8 +164,8 @@ parseV2DirFileTables(const DWARFDataExtractor &DebugLineData,
     StringRef S = DebugLineData.getCStrRef(OffsetPtr);
     if (S.empty())
       break;
-    DWARFFormValue Dir(dwarf::DW_FORM_string);
-    Dir.setPValue(S.data());
+    DWARFFormValue Dir =
+        DWARFFormValue::createFromPValue(dwarf::DW_FORM_string, S.data());
     IncludeDirectories.push_back(Dir);
   }
 
@@ -155,8 +174,8 @@ parseV2DirFileTables(const DWARFDataExtractor &DebugLineData,
     if (Name.empty())
       break;
     DWARFDebugLine::FileNameEntry FileEntry;
-    FileEntry.Name.setForm(dwarf::DW_FORM_string);
-    FileEntry.Name.setPValue(Name.data());
+    FileEntry.Name =
+        DWARFFormValue::createFromPValue(dwarf::DW_FORM_string, Name.data());
     FileEntry.DirIdx = DebugLineData.getULEB128(OffsetPtr);
     FileEntry.ModTime = DebugLineData.getULEB128(OffsetPtr);
     FileEntry.Length = DebugLineData.getULEB128(OffsetPtr);
@@ -281,11 +300,11 @@ Error DWARFDebugLine::Prologue::parse(const DWARFDataExtractor &DebugLineData,
   const uint64_t PrologueOffset = *OffsetPtr;
 
   clear();
-  TotalLength = DebugLineData.getU32(OffsetPtr);
+  TotalLength = DebugLineData.getRelocatedValue(4, OffsetPtr);
   if (TotalLength == UINT32_MAX) {
     FormParams.Format = dwarf::DWARF64;
     TotalLength = DebugLineData.getU64(OffsetPtr);
-  } else if (TotalLength >= 0xffffff00) {
+  } else if (TotalLength >= 0xfffffff0) {
     return createStringError(errc::invalid_argument,
         "parsing line table prologue at offset 0x%8.8" PRIx64
         " unsupported reserved unit length found of value 0x%8.8" PRIx64,
@@ -306,7 +325,8 @@ Error DWARFDebugLine::Prologue::parse(const DWARFDataExtractor &DebugLineData,
     SegSelectorSize = DebugLineData.getU8(OffsetPtr);
   }
 
-  PrologueLength = DebugLineData.getUnsigned(OffsetPtr, sizeofPrologueLength());
+  PrologueLength =
+      DebugLineData.getRelocatedValue(sizeofPrologueLength(), OffsetPtr);
   const uint64_t EndPrologueOffset = PrologueLength + *OffsetPtr;
   MinInstLength = DebugLineData.getU8(OffsetPtr);
   if (getVersion() >= 4)
@@ -348,13 +368,15 @@ Error DWARFDebugLine::Prologue::parse(const DWARFDataExtractor &DebugLineData,
 DWARFDebugLine::Row::Row(bool DefaultIsStmt) { reset(DefaultIsStmt); }
 
 void DWARFDebugLine::Row::postAppend() {
+  Discriminator = 0;
   BasicBlock = false;
   PrologueEnd = false;
   EpilogueBegin = false;
 }
 
 void DWARFDebugLine::Row::reset(bool DefaultIsStmt) {
-  Address = 0;
+  Address.Address = 0;
+  Address.SectionIndex = object::SectionedAddress::UndefSection;
   Line = 1;
   Column = 0;
   File = 1;
@@ -374,7 +396,7 @@ void DWARFDebugLine::Row::dumpTableHeader(raw_ostream &OS) {
 }
 
 void DWARFDebugLine::Row::dump(raw_ostream &OS) const {
-  OS << format("0x%16.16" PRIx64 " %6u %6u", Address, Line, Column)
+  OS << format("0x%16.16" PRIx64 " %6u %6u", Address.Address, Line, Column)
      << format(" %6u %3u %13u ", File, Isa, Discriminator)
      << (IsStmt ? " is_stmt" : "") << (BasicBlock ? " basic_block" : "")
      << (PrologueEnd ? " prologue_end" : "")
@@ -387,6 +409,7 @@ DWARFDebugLine::Sequence::Sequence() { reset(); }
 void DWARFDebugLine::Sequence::reset() {
   LowPC = 0;
   HighPC = 0;
+  SectionIndex = object::SectionedAddress::UndefSection;
   FirstRowIndex = 0;
   LastRowIndex = 0;
   Empty = true;
@@ -423,19 +446,20 @@ void DWARFDebugLine::ParsingState::resetRowAndSequence() {
   Sequence.reset();
 }
 
-void DWARFDebugLine::ParsingState::appendRowToMatrix(uint32_t Offset) {
+void DWARFDebugLine::ParsingState::appendRowToMatrix() {
+  unsigned RowNumber = LineTable->Rows.size();
   if (Sequence.Empty) {
     // Record the beginning of instruction sequence.
     Sequence.Empty = false;
-    Sequence.LowPC = Row.Address;
+    Sequence.LowPC = Row.Address.Address;
     Sequence.FirstRowIndex = RowNumber;
   }
-  ++RowNumber;
   LineTable->appendRow(Row);
   if (Row.EndSequence) {
     // Record the end of instruction sequence.
-    Sequence.HighPC = Row.Address;
-    Sequence.LastRowIndex = RowNumber;
+    Sequence.HighPC = Row.Address.Address;
+    Sequence.LastRowIndex = RowNumber + 1;
+    Sequence.SectionIndex = Row.Address.SectionIndex;
     if (Sequence.isValid())
       LineTable->appendSequence(Sequence);
     Sequence.reset();
@@ -538,7 +562,7 @@ Error DWARFDebugLine::LineTable::parse(
         // address is that of the byte after the last target machine instruction
         // of the sequence.
         State.Row.EndSequence = true;
-        State.appendRowToMatrix(*OffsetPtr);
+        State.appendRowToMatrix();
         if (OS) {
           *OS << "\n";
           OS->indent(12);
@@ -566,9 +590,10 @@ Error DWARFDebugLine::LineTable::parse(
                              ExtOffset, DebugLineData.getAddressSize(),
                              Len - 1);
         }
-        State.Row.Address = DebugLineData.getRelocatedAddress(OffsetPtr);
+        State.Row.Address.Address = DebugLineData.getRelocatedAddress(
+            OffsetPtr, &State.Row.Address.SectionIndex);
         if (OS)
-          *OS << format(" (0x%16.16" PRIx64 ")", State.Row.Address);
+          *OS << format(" (0x%16.16" PRIx64 ")", State.Row.Address.Address);
         break;
 
       case DW_LNE_define_file:
@@ -595,8 +620,8 @@ Error DWARFDebugLine::LineTable::parse(
         {
           FileNameEntry FileEntry;
           const char *Name = DebugLineData.getCStr(OffsetPtr);
-          FileEntry.Name.setForm(dwarf::DW_FORM_string);
-          FileEntry.Name.setPValue(Name);
+          FileEntry.Name =
+              DWARFFormValue::createFromPValue(dwarf::DW_FORM_string, Name);
           FileEntry.DirIdx = DebugLineData.getULEB128(OffsetPtr);
           FileEntry.ModTime = DebugLineData.getULEB128(OffsetPtr);
           FileEntry.Length = DebugLineData.getULEB128(OffsetPtr);
@@ -637,15 +662,14 @@ Error DWARFDebugLine::LineTable::parse(
       // Standard Opcodes
       case DW_LNS_copy:
         // Takes no arguments. Append a row to the matrix using the
-        // current values of the state-machine registers. Then set
-        // the basic_block register to false.
-        State.appendRowToMatrix(*OffsetPtr);
+        // current values of the state-machine registers.
         if (OS) {
           *OS << "\n";
           OS->indent(12);
           State.Row.dump(*OS);
           *OS << "\n";
         }
+        State.appendRowToMatrix();
         break;
 
       case DW_LNS_advance_pc:
@@ -655,7 +679,7 @@ Error DWARFDebugLine::LineTable::parse(
         {
           uint64_t AddrOffset =
               DebugLineData.getULEB128(OffsetPtr) * Prologue.MinInstLength;
-          State.Row.Address += AddrOffset;
+          State.Row.Address.Address += AddrOffset;
           if (OS)
             *OS << " (" << AddrOffset << ")";
         }
@@ -713,7 +737,7 @@ Error DWARFDebugLine::LineTable::parse(
           uint8_t AdjustOpcode = 255 - Prologue.OpcodeBase;
           uint64_t AddrOffset =
               (AdjustOpcode / Prologue.LineRange) * Prologue.MinInstLength;
-          State.Row.Address += AddrOffset;
+          State.Row.Address.Address += AddrOffset;
           if (OS)
             *OS
                 << format(" (0x%16.16" PRIx64 ")", AddrOffset);
@@ -731,11 +755,11 @@ Error DWARFDebugLine::LineTable::parse(
         // requires the use of DW_LNS_advance_pc. Such assemblers, however,
         // can use DW_LNS_fixed_advance_pc instead, sacrificing compression.
         {
-          uint16_t PCOffset = DebugLineData.getU16(OffsetPtr);
-          State.Row.Address += PCOffset;
+          uint16_t PCOffset = DebugLineData.getRelocatedValue(2, OffsetPtr);
+          State.Row.Address.Address += PCOffset;
           if (OS)
             *OS
-                << format(" (0x%16.16" PRIx64 ")", PCOffset);
+                << format(" (0x%4.4" PRIx16 ")", PCOffset);
         }
         break;
 
@@ -815,18 +839,16 @@ Error DWARFDebugLine::LineTable::parse(
       int32_t LineOffset =
           Prologue.LineBase + (AdjustOpcode % Prologue.LineRange);
       State.Row.Line += LineOffset;
-      State.Row.Address += AddrOffset;
+      State.Row.Address.Address += AddrOffset;
 
       if (OS) {
-        *OS << "address += " << ((uint32_t)AdjustOpcode)
-            << ",  line += " << LineOffset << "\n";
+        *OS << "address += " << AddrOffset << ",  line += " << LineOffset
+            << "\n";
         OS->indent(12);
         State.Row.dump(*OS);
       }
 
-      State.appendRowToMatrix(*OffsetPtr);
-      // Reset discriminator to 0.
-      State.Row.Discriminator = 0;
+      State.appendRowToMatrix();
     }
     if(OS)
       *OS << "\n";
@@ -839,7 +861,7 @@ Error DWARFDebugLine::LineTable::parse(
 
   // Sort all sequences so that address lookup will work faster.
   if (!Sequences.empty()) {
-    llvm::sort(Sequences, Sequence::orderByLowPC);
+    llvm::sort(Sequences, Sequence::orderByHighPC);
     // Note: actually, instruction address ranges of sequences should not
     // overlap (in shared objects and executables). If they do, the address
     // lookup would still work, though, but result would be ambiguous.
@@ -851,74 +873,88 @@ Error DWARFDebugLine::LineTable::parse(
   return Error::success();
 }
 
-uint32_t
-DWARFDebugLine::LineTable::findRowInSeq(const DWARFDebugLine::Sequence &Seq,
-                                        uint64_t Address) const {
+uint32_t DWARFDebugLine::LineTable::findRowInSeq(
+    const DWARFDebugLine::Sequence &Seq,
+    object::SectionedAddress Address) const {
   if (!Seq.containsPC(Address))
     return UnknownRowIndex;
-  // Search for instruction address in the rows describing the sequence.
-  // Rows are stored in a vector, so we may use arithmetical operations with
-  // iterators.
+  assert(Seq.SectionIndex == Address.SectionIndex);
+  // In some cases, e.g. first instruction in a function, the compiler generates
+  // two entries, both with the same address. We want the last one.
+  //
+  // In general we want a non-empty range: the last row whose address is less
+  // than or equal to Address. This can be computed as upper_bound - 1.
   DWARFDebugLine::Row Row;
   Row.Address = Address;
   RowIter FirstRow = Rows.begin() + Seq.FirstRowIndex;
   RowIter LastRow = Rows.begin() + Seq.LastRowIndex;
-  LineTable::RowIter RowPos = std::lower_bound(
-      FirstRow, LastRow, Row, DWARFDebugLine::Row::orderByAddress);
-  if (RowPos == LastRow) {
-    return Seq.LastRowIndex - 1;
-  }
-  uint32_t Index = Seq.FirstRowIndex + (RowPos - FirstRow);
-  if (RowPos->Address > Address) {
-    if (RowPos == FirstRow)
-      return UnknownRowIndex;
-    else
-      Index--;
-  }
-  return Index;
+  assert(FirstRow->Address.Address <= Row.Address.Address &&
+         Row.Address.Address < LastRow[-1].Address.Address);
+  RowIter RowPos = std::upper_bound(FirstRow + 1, LastRow - 1, Row,
+                                    DWARFDebugLine::Row::orderByAddress) -
+                   1;
+  assert(Seq.SectionIndex == RowPos->Address.SectionIndex);
+  return RowPos - Rows.begin();
 }
 
-uint32_t DWARFDebugLine::LineTable::lookupAddress(uint64_t Address) const {
-  if (Sequences.empty())
-    return UnknownRowIndex;
+uint32_t DWARFDebugLine::LineTable::lookupAddress(
+    object::SectionedAddress Address) const {
+
+  // Search for relocatable addresses
+  uint32_t Result = lookupAddressImpl(Address);
+
+  if (Result != UnknownRowIndex ||
+      Address.SectionIndex == object::SectionedAddress::UndefSection)
+    return Result;
+
+  // Search for absolute addresses
+  Address.SectionIndex = object::SectionedAddress::UndefSection;
+  return lookupAddressImpl(Address);
+}
+
+uint32_t DWARFDebugLine::LineTable::lookupAddressImpl(
+    object::SectionedAddress Address) const {
   // First, find an instruction sequence containing the given address.
   DWARFDebugLine::Sequence Sequence;
-  Sequence.LowPC = Address;
-  SequenceIter FirstSeq = Sequences.begin();
-  SequenceIter LastSeq = Sequences.end();
-  SequenceIter SeqPos = std::lower_bound(
-      FirstSeq, LastSeq, Sequence, DWARFDebugLine::Sequence::orderByLowPC);
-  DWARFDebugLine::Sequence FoundSeq;
-  if (SeqPos == LastSeq) {
-    FoundSeq = Sequences.back();
-  } else if (SeqPos->LowPC == Address) {
-    FoundSeq = *SeqPos;
-  } else {
-    if (SeqPos == FirstSeq)
-      return UnknownRowIndex;
-    FoundSeq = *(SeqPos - 1);
-  }
-  return findRowInSeq(FoundSeq, Address);
+  Sequence.SectionIndex = Address.SectionIndex;
+  Sequence.HighPC = Address.Address;
+  SequenceIter It = llvm::upper_bound(Sequences, Sequence,
+                                      DWARFDebugLine::Sequence::orderByHighPC);
+  if (It == Sequences.end() || It->SectionIndex != Address.SectionIndex)
+    return UnknownRowIndex;
+  return findRowInSeq(*It, Address);
 }
 
 bool DWARFDebugLine::LineTable::lookupAddressRange(
-    uint64_t Address, uint64_t Size, std::vector<uint32_t> &Result) const {
+    object::SectionedAddress Address, uint64_t Size,
+    std::vector<uint32_t> &Result) const {
+
+  // Search for relocatable addresses
+  if (lookupAddressRangeImpl(Address, Size, Result))
+    return true;
+
+  if (Address.SectionIndex == object::SectionedAddress::UndefSection)
+    return false;
+
+  // Search for absolute addresses
+  Address.SectionIndex = object::SectionedAddress::UndefSection;
+  return lookupAddressRangeImpl(Address, Size, Result);
+}
+
+bool DWARFDebugLine::LineTable::lookupAddressRangeImpl(
+    object::SectionedAddress Address, uint64_t Size,
+    std::vector<uint32_t> &Result) const {
   if (Sequences.empty())
     return false;
-  uint64_t EndAddr = Address + Size;
+  uint64_t EndAddr = Address.Address + Size;
   // First, find an instruction sequence containing the given address.
   DWARFDebugLine::Sequence Sequence;
-  Sequence.LowPC = Address;
-  SequenceIter FirstSeq = Sequences.begin();
+  Sequence.SectionIndex = Address.SectionIndex;
+  Sequence.HighPC = Address.Address;
   SequenceIter LastSeq = Sequences.end();
-  SequenceIter SeqPos = std::lower_bound(
-      FirstSeq, LastSeq, Sequence, DWARFDebugLine::Sequence::orderByLowPC);
-  if (SeqPos == LastSeq || SeqPos->LowPC != Address) {
-    if (SeqPos == FirstSeq)
-      return false;
-    SeqPos--;
-  }
-  if (!SeqPos->containsPC(Address))
+  SequenceIter SeqPos = llvm::upper_bound(
+      Sequences, Sequence, DWARFDebugLine::Sequence::orderByHighPC);
+  if (SeqPos == LastSeq || !SeqPos->containsPC(Address))
     return false;
 
   SequenceIter StartPos = SeqPos;
@@ -935,7 +971,8 @@ bool DWARFDebugLine::LineTable::lookupAddressRange(
       FirstRowIndex = findRowInSeq(CurSeq, Address);
 
     // Figure out the last row in the range.
-    uint32_t LastRowIndex = findRowInSeq(CurSeq, EndAddr - 1);
+    uint32_t LastRowIndex =
+        findRowInSeq(CurSeq, {EndAddr - 1, Address.SectionIndex});
     if (LastRowIndex == UnknownRowIndex)
       LastRowIndex = CurSeq.LastRowIndex - 1;
 
@@ -952,15 +989,11 @@ bool DWARFDebugLine::LineTable::lookupAddressRange(
   return true;
 }
 
-bool DWARFDebugLine::LineTable::hasFileAtIndex(uint64_t FileIndex) const {
-  return FileIndex != 0 && FileIndex <= Prologue.FileNames.size();
-}
-
 Optional<StringRef> DWARFDebugLine::LineTable::getSourceByIndex(uint64_t FileIndex,
                                                                 FileLineInfoKind Kind) const {
-  if (Kind == FileLineInfoKind::None || !hasFileAtIndex(FileIndex))
+  if (Kind == FileLineInfoKind::None || !Prologue.hasFileAtIndex(FileIndex))
     return None;
-  const FileNameEntry &Entry = Prologue.FileNames[FileIndex - 1];
+  const FileNameEntry &Entry = Prologue.getFileNameEntry(FileIndex);
   if (Optional<const char *> source = Entry.Source.getAsCString())
     return StringRef(*source);
   return None;
@@ -974,13 +1007,13 @@ static bool isPathAbsoluteOnWindowsOrPosix(const Twine &Path) {
          sys::path::is_absolute(Path, sys::path::Style::windows);
 }
 
-bool DWARFDebugLine::LineTable::getFileNameByIndex(uint64_t FileIndex,
-                                                   const char *CompDir,
-                                                   FileLineInfoKind Kind,
-                                                   std::string &Result) const {
+bool DWARFDebugLine::Prologue::getFileNameByIndex(uint64_t FileIndex,
+                                                  StringRef CompDir,
+                                                  FileLineInfoKind Kind,
+                                                  std::string &Result) const {
   if (Kind == FileLineInfoKind::None || !hasFileAtIndex(FileIndex))
     return false;
-  const FileNameEntry &Entry = Prologue.FileNames[FileIndex - 1];
+  const FileNameEntry &Entry = getFileNameEntry(FileIndex);
   StringRef FileName = Entry.Name.getAsCString().getValue();
   if (Kind != FileLineInfoKind::AbsoluteFilePath ||
       isPathAbsoluteOnWindowsOrPosix(FileName)) {
@@ -989,21 +1022,22 @@ bool DWARFDebugLine::LineTable::getFileNameByIndex(uint64_t FileIndex,
   }
 
   SmallString<16> FilePath;
-  uint64_t IncludeDirIndex = Entry.DirIdx;
   StringRef IncludeDir;
   // Be defensive about the contents of Entry.
-  if (IncludeDirIndex > 0 &&
-      IncludeDirIndex <= Prologue.IncludeDirectories.size())
-    IncludeDir = Prologue.IncludeDirectories[IncludeDirIndex - 1]
-                     .getAsCString()
-                     .getValue();
-
-  // We may still need to append compilation directory of compile unit.
-  // We know that FileName is not absolute, the only way to have an
-  // absolute path at this point would be if IncludeDir is absolute.
-  if (CompDir && Kind == FileLineInfoKind::AbsoluteFilePath &&
-      !isPathAbsoluteOnWindowsOrPosix(IncludeDir))
-    sys::path::append(FilePath, CompDir);
+  if (getVersion() >= 5) {
+    if (Entry.DirIdx < IncludeDirectories.size())
+      IncludeDir = IncludeDirectories[Entry.DirIdx].getAsCString().getValue();
+  } else {
+    if (0 < Entry.DirIdx && Entry.DirIdx <= IncludeDirectories.size())
+      IncludeDir =
+          IncludeDirectories[Entry.DirIdx - 1].getAsCString().getValue();
+
+    // We may still need to append compilation directory of compile unit.
+    // We know that FileName is not absolute, the only way to have an
+    // absolute path at this point would be if IncludeDir is absolute.
+    if (!CompDir.empty() && !isPathAbsoluteOnWindowsOrPosix(IncludeDir))
+      sys::path::append(FilePath, CompDir);
+  }
 
   // sys::path::append skips empty strings.
   sys::path::append(FilePath, IncludeDir, FileName);
@@ -1012,8 +1046,8 @@ bool DWARFDebugLine::LineTable::getFileNameByIndex(uint64_t FileIndex,
 }
 
 bool DWARFDebugLine::LineTable::getFileLineInfoForAddress(
-    uint64_t Address, const char *CompDir, FileLineInfoKind Kind,
-    DILineInfo &Result) const {
+    object::SectionedAddress Address, const char *CompDir,
+    FileLineInfoKind Kind, DILineInfo &Result) const {
   // Get the index of row we're looking for in the line table.
   uint32_t RowIndex = lookupAddress(Address);
   if (RowIndex == -1U)
@@ -1058,7 +1092,7 @@ DWARFDebugLine::SectionParser::SectionParser(DWARFDataExtractor &Data,
 }
 
 bool DWARFDebugLine::Prologue::totalLengthIsValid() const {
-  return TotalLength == 0xffffffff || TotalLength < 0xffffff00;
+  return TotalLength == 0xffffffff || TotalLength < 0xfffffff0;
 }
 
 DWARFDebugLine::LineTable DWARFDebugLine::SectionParser::parseNext(
diff --git a/lib/DebugInfo/DWARF/DWARFDebugLoc.cpp b/lib/DebugInfo/DWARF/DWARFDebugLoc.cpp
index f8b5ff6ec8fb..6d8f4bee77c4 100644
--- a/lib/DebugInfo/DWARF/DWARFDebugLoc.cpp
+++ b/lib/DebugInfo/DWARF/DWARFDebugLoc.cpp
@@ -1,9 +1,8 @@
 //===- DWARFDebugLoc.cpp --------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
@@ -31,15 +30,16 @@ using namespace llvm;
 // non-LLVM tools.
 static void dumpExpression(raw_ostream &OS, ArrayRef<char> Data,
                            bool IsLittleEndian, unsigned AddressSize,
-                           const MCRegisterInfo *MRI) {
+                           const MCRegisterInfo *MRI, DWARFUnit *U) {
   DWARFDataExtractor Extractor(StringRef(Data.data(), Data.size()),
                                IsLittleEndian, AddressSize);
-  DWARFExpression(Extractor, dwarf::DWARF_VERSION, AddressSize).print(OS, MRI);
+  DWARFExpression(Extractor, dwarf::DWARF_VERSION, AddressSize).print(OS, MRI, U);
 }
 
 void DWARFDebugLoc::LocationList::dump(raw_ostream &OS, bool IsLittleEndian,
                                        unsigned AddressSize,
                                        const MCRegisterInfo *MRI,
+                                       DWARFUnit *U,
                                        uint64_t BaseAddress,
                                        unsigned Indent) const {
   for (const Entry &E : Entries) {
@@ -51,15 +51,14 @@ void DWARFDebugLoc::LocationList::dump(raw_ostream &OS, bool IsLittleEndian,
                  BaseAddress + E.End);
     OS << ": ";
 
-    dumpExpression(OS, E.Loc, IsLittleEndian, AddressSize, MRI);
+    dumpExpression(OS, E.Loc, IsLittleEndian, AddressSize, MRI, U);
   }
 }
 
 DWARFDebugLoc::LocationList const *
 DWARFDebugLoc::getLocationListAtOffset(uint64_t Offset) const {
-  auto It = std::lower_bound(
-      Locations.begin(), Locations.end(), Offset,
-      [](const LocationList &L, uint64_t Offset) { return L.Offset < Offset; });
+  auto It = partition_point(
+      Locations, [=](const LocationList &L) { return L.Offset < Offset; });
   if (It != Locations.end() && It->Offset == Offset)
     return &(*It);
   return nullptr;
@@ -69,7 +68,7 @@ void DWARFDebugLoc::dump(raw_ostream &OS, const MCRegisterInfo *MRI,
                          Optional<uint64_t> Offset) const {
   auto DumpLocationList = [&](const LocationList &L) {
     OS << format("0x%8.8x: ", L.Offset);
-    L.dump(OS, IsLittleEndian, AddressSize, MRI, 0, 12);
+    L.dump(OS, IsLittleEndian, AddressSize, MRI, nullptr, 0, 12);
     OS << "\n\n";
   };
 
@@ -184,7 +183,8 @@ DWARFDebugLoclists::parseOneLocationList(DataExtractor Data, unsigned *Offset,
     }
 
     if (Kind != dwarf::DW_LLE_base_address) {
-      unsigned Bytes = Data.getU16(Offset);
+      unsigned Bytes =
+          Version >= 5 ? Data.getULEB128(Offset) : Data.getU16(Offset);
       // A single location description describing the location of the object...
       StringRef str = Data.getData().substr(*Offset, Bytes);
       *Offset += Bytes;
@@ -212,9 +212,8 @@ void DWARFDebugLoclists::parse(DataExtractor data, unsigned Version) {
 
 DWARFDebugLoclists::LocationList const *
 DWARFDebugLoclists::getLocationListAtOffset(uint64_t Offset) const {
-  auto It = std::lower_bound(
-      Locations.begin(), Locations.end(), Offset,
-      [](const LocationList &L, uint64_t Offset) { return L.Offset < Offset; });
+  auto It = partition_point(
+      Locations, [=](const LocationList &L) { return L.Offset < Offset; });
   if (It != Locations.end() && It->Offset == Offset)
     return &(*It);
   return nullptr;
@@ -224,6 +223,7 @@ void DWARFDebugLoclists::LocationList::dump(raw_ostream &OS, uint64_t BaseAddr,
                                             bool IsLittleEndian,
                                             unsigned AddressSize,
                                             const MCRegisterInfo *MRI,
+                                            DWARFUnit *U,
                                             unsigned Indent) const {
   for (const Entry &E : Entries) {
     switch (E.Kind) {
@@ -253,7 +253,7 @@ void DWARFDebugLoclists::LocationList::dump(raw_ostream &OS, uint64_t BaseAddr,
       llvm_unreachable("unreachable locations list kind");
     }
 
-    dumpExpression(OS, E.Loc, IsLittleEndian, AddressSize, MRI);
+    dumpExpression(OS, E.Loc, IsLittleEndian, AddressSize, MRI, U);
   }
 }
 
@@ -262,7 +262,7 @@ void DWARFDebugLoclists::dump(raw_ostream &OS, uint64_t BaseAddr,
                               Optional<uint64_t> Offset) const {
   auto DumpLocationList = [&](const LocationList &L) {
     OS << format("0x%8.8x: ", L.Offset);
-    L.dump(OS, BaseAddr, IsLittleEndian, AddressSize, MRI, /*Indent=*/12);
+    L.dump(OS, BaseAddr, IsLittleEndian, AddressSize, MRI, nullptr, /*Indent=*/12);
     OS << "\n\n";
   };
 
diff --git a/lib/DebugInfo/DWARF/DWARFDebugMacro.cpp b/lib/DebugInfo/DWARF/DWARFDebugMacro.cpp
index 6d789c3027a5..3317a778cc70 100644
--- a/lib/DebugInfo/DWARF/DWARFDebugMacro.cpp
+++ b/lib/DebugInfo/DWARF/DWARFDebugMacro.cpp
@@ -1,9 +1,8 @@
 //===- DWARFDebugMacro.cpp ------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
diff --git a/lib/DebugInfo/DWARF/DWARFDebugPubTable.cpp b/lib/DebugInfo/DWARF/DWARFDebugPubTable.cpp
index abd1ad59a9c1..963ec64f5e91 100644
--- a/lib/DebugInfo/DWARF/DWARFDebugPubTable.cpp
+++ b/lib/DebugInfo/DWARF/DWARFDebugPubTable.cpp
@@ -1,9 +1,8 @@
 //===- DWARFDebugPubTable.cpp ---------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
diff --git a/lib/DebugInfo/DWARF/DWARFDebugRangeList.cpp b/lib/DebugInfo/DWARF/DWARFDebugRangeList.cpp
index dfb913000a46..d8df81a0aa0b 100644
--- a/lib/DebugInfo/DWARF/DWARFDebugRangeList.cpp
+++ b/lib/DebugInfo/DWARF/DWARFDebugRangeList.cpp
@@ -1,9 +1,8 @@
 //===- DWARFDebugRangesList.cpp -------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
@@ -69,7 +68,7 @@ void DWARFDebugRangeList::dump(raw_ostream &OS) const {
 }
 
 DWARFAddressRangesVector DWARFDebugRangeList::getAbsoluteRanges(
-    llvm::Optional<SectionedAddress> BaseAddr) const {
+    llvm::Optional<object::SectionedAddress> BaseAddr) const {
   DWARFAddressRangesVector Res;
   for (const RangeListEntry &RLE : Entries) {
     if (RLE.isBaseAddressSelectionEntry(AddressSize)) {
diff --git a/lib/DebugInfo/DWARF/DWARFDebugRnglists.cpp b/lib/DebugInfo/DWARF/DWARFDebugRnglists.cpp
index 60c6eb30857f..5ac3326f6681 100644
--- a/lib/DebugInfo/DWARF/DWARFDebugRnglists.cpp
+++ b/lib/DebugInfo/DWARF/DWARFDebugRnglists.cpp
@@ -1,9 +1,8 @@
 //===- DWARFDebugRnglists.cpp ---------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
@@ -113,9 +112,8 @@ Error RangeListEntry::extract(DWARFDataExtractor Data, uint32_t End,
   return Error::success();
 }
 
-DWARFAddressRangesVector
-DWARFDebugRnglist::getAbsoluteRanges(llvm::Optional<SectionedAddress> BaseAddr,
-                                     DWARFUnit &U) const {
+DWARFAddressRangesVector DWARFDebugRnglist::getAbsoluteRanges(
+    llvm::Optional<object::SectionedAddress> BaseAddr, DWARFUnit &U) const {
   DWARFAddressRangesVector Res;
   for (const RangeListEntry &RLE : Entries) {
     if (RLE.EntryKind == dwarf::DW_RLE_end_of_list)
@@ -175,7 +173,7 @@ DWARFDebugRnglist::getAbsoluteRanges(llvm::Optional<SectionedAddress> BaseAddr,
 void RangeListEntry::dump(
     raw_ostream &OS, uint8_t AddrSize, uint8_t MaxEncodingStringLength,
     uint64_t &CurrentBase, DIDumpOptions DumpOpts,
-    llvm::function_ref<Optional<SectionedAddress>(uint32_t)>
+    llvm::function_ref<Optional<object::SectionedAddress>(uint32_t)>
         LookupPooledAddress) const {
   auto PrintRawEntry = [](raw_ostream &OS, const RangeListEntry &Entry,
                           uint8_t AddrSize, DIDumpOptions DumpOpts) {
@@ -203,7 +201,6 @@ void RangeListEntry::dump(
   case dwarf::DW_RLE_end_of_list:
     OS << (DumpOpts.Verbose ? "" : "<End of list>");
     break;
-    //  case dwarf::DW_RLE_base_addressx:
   case dwarf::DW_RLE_base_addressx: {
     if (auto SA = LookupPooledAddress(Value0))
       CurrentBase = SA->Address;
@@ -240,7 +237,7 @@ void RangeListEntry::dump(
       Start = SA->Address;
     DWARFAddressRange(Start, Start + Value1).dump(OS, AddrSize, DumpOpts);
     break;
-  } break;
+  }
   default:
     llvm_unreachable("Unsupported range list encoding");
   }
diff --git a/lib/DebugInfo/DWARF/DWARFDie.cpp b/lib/DebugInfo/DWARF/DWARFDie.cpp
index 81ef0c8c7aec..d638dc4239f4 100644
--- a/lib/DebugInfo/DWARF/DWARFDie.cpp
+++ b/lib/DebugInfo/DWARF/DWARFDie.cpp
@@ -1,9 +1,8 @@
 //===- DWARFDie.cpp -------------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
@@ -87,7 +86,7 @@ static void dumpLocation(raw_ostream &OS, DWARFFormValue &FormValue,
     DataExtractor Data(StringRef((const char *)Expr.data(), Expr.size()),
                        Ctx.isLittleEndian(), 0);
     DWARFExpression(Data, U->getVersion(), U->getAddressByteSize())
-        .print(OS, MRI);
+        .print(OS, MRI, U);
     return;
   }
 
@@ -101,10 +100,10 @@ static void dumpLocation(raw_ostream &OS, DWARFFormValue &FormValue,
       auto LL = DebugLoc.parseOneLocationList(Data, &Offset);
       if (LL) {
         uint64_t BaseAddr = 0;
-        if (Optional<SectionedAddress> BA = U->getBaseAddress())
+        if (Optional<object::SectionedAddress> BA = U->getBaseAddress())
           BaseAddr = BA->Address;
-        LL->dump(OS, Ctx.isLittleEndian(), Obj.getAddressSize(), MRI, BaseAddr,
-                 Indent);
+        LL->dump(OS, Ctx.isLittleEndian(), Obj.getAddressSize(), MRI, U,
+                 BaseAddr, Indent);
       } else
         OS << "error extracting location list.";
       return;
@@ -126,12 +125,12 @@ static void dumpLocation(raw_ostream &OS, DWARFFormValue &FormValue,
           Data, &Offset, UseLocLists ? U->getVersion() : 4);
 
       uint64_t BaseAddr = 0;
-      if (Optional<SectionedAddress> BA = U->getBaseAddress())
+      if (Optional<object::SectionedAddress> BA = U->getBaseAddress())
         BaseAddr = BA->Address;
 
       if (LL)
         LL->dump(OS, BaseAddr, Ctx.isLittleEndian(), Obj.getAddressSize(), MRI,
-                 Indent);
+                 U, Indent);
       else
         OS << "error extracting location list.";
     }
@@ -279,11 +278,7 @@ static void dumpAttribute(raw_ostream &OS, const DWARFDie &Die,
     OS << formatv(" [{0}]", Form);
 
   DWARFUnit *U = Die.getDwarfUnit();
-  DWARFFormValue formValue(Form);
-
-  if (!formValue.extractValue(U->getDebugInfoExtractor(), OffsetPtr,
-                              U->getFormParams(), U))
-    return;
+  DWARFFormValue FormValue = DWARFFormValue::createFromUnit(Form, U, OffsetPtr);
 
   OS << "\t(";
 
@@ -294,35 +289,33 @@ static void dumpAttribute(raw_ostream &OS, const DWARFDie &Die,
     Color = HighlightColor::String;
     if (const auto *LT = U->getContext().getLineTableForUnit(U))
       if (LT->getFileNameByIndex(
-              formValue.getAsUnsignedConstant().getValue(),
+              FormValue.getAsUnsignedConstant().getValue(),
               U->getCompilationDir(),
               DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath, File)) {
         File = '"' + File + '"';
         Name = File;
       }
-  } else if (Optional<uint64_t> Val = formValue.getAsUnsignedConstant())
+  } else if (Optional<uint64_t> Val = FormValue.getAsUnsignedConstant())
     Name = AttributeValueString(Attr, *Val);
 
   if (!Name.empty())
     WithColor(OS, Color) << Name;
   else if (Attr == DW_AT_decl_line || Attr == DW_AT_call_line)
-    OS << *formValue.getAsUnsignedConstant();
+    OS << *FormValue.getAsUnsignedConstant();
   else if (Attr == DW_AT_high_pc && !DumpOpts.ShowForm && !DumpOpts.Verbose &&
-           formValue.getAsUnsignedConstant()) {
+           FormValue.getAsUnsignedConstant()) {
     if (DumpOpts.ShowAddresses) {
       // Print the actual address rather than the offset.
       uint64_t LowPC, HighPC, Index;
       if (Die.getLowAndHighPC(LowPC, HighPC, Index))
         OS << format("0x%016" PRIx64, HighPC);
       else
-        formValue.dump(OS, DumpOpts);
+        FormValue.dump(OS, DumpOpts);
     }
-  } else if (Attr == DW_AT_location || Attr == DW_AT_frame_base ||
-             Attr == DW_AT_data_member_location ||
-             Attr == DW_AT_GNU_call_site_value)
-    dumpLocation(OS, formValue, U, sizeof(BaseIndent) + Indent + 4, DumpOpts);
+  } else if (DWARFAttribute::mayHaveLocationDescription(Attr))
+    dumpLocation(OS, FormValue, U, sizeof(BaseIndent) + Indent + 4, DumpOpts);
   else
-    formValue.dump(OS, DumpOpts);
+    FormValue.dump(OS, DumpOpts);
 
   std::string Space = DumpOpts.ShowAddresses ? " " : "";
 
@@ -331,25 +324,25 @@ static void dumpAttribute(raw_ostream &OS, const DWARFDie &Die,
   // interesting. These attributes are handled below.
   if (Attr == DW_AT_specification || Attr == DW_AT_abstract_origin) {
     if (const char *Name =
-            Die.getAttributeValueAsReferencedDie(formValue).getName(
+            Die.getAttributeValueAsReferencedDie(FormValue).getName(
                 DINameKind::LinkageName))
       OS << Space << "\"" << Name << '\"';
   } else if (Attr == DW_AT_type) {
     OS << Space << "\"";
-    dumpTypeName(OS, Die.getAttributeValueAsReferencedDie(formValue));
+    dumpTypeName(OS, Die.getAttributeValueAsReferencedDie(FormValue));
     OS << '"';
   } else if (Attr == DW_AT_APPLE_property_attribute) {
-    if (Optional<uint64_t> OptVal = formValue.getAsUnsignedConstant())
+    if (Optional<uint64_t> OptVal = FormValue.getAsUnsignedConstant())
       dumpApplePropertyAttribute(OS, *OptVal);
   } else if (Attr == DW_AT_ranges) {
     const DWARFObject &Obj = Die.getDwarfUnit()->getContext().getDWARFObj();
     // For DW_FORM_rnglistx we need to dump the offset separately, since
     // we have only dumped the index so far.
-    if (formValue.getForm() == DW_FORM_rnglistx)
+    if (FormValue.getForm() == DW_FORM_rnglistx)
       if (auto RangeListOffset =
-              U->getRnglistOffset(*formValue.getAsSectionOffset())) {
-        DWARFFormValue FV(dwarf::DW_FORM_sec_offset);
-        FV.setUValue(*RangeListOffset);
+              U->getRnglistOffset(*FormValue.getAsSectionOffset())) {
+        DWARFFormValue FV = DWARFFormValue::createFromUValue(
+            dwarf::DW_FORM_sec_offset, *RangeListOffset);
         FV.dump(OS, DumpOpts);
       }
     if (auto RangesOrError = Die.getAddressRanges())
@@ -403,6 +396,7 @@ DWARFDie::findRecursively(ArrayRef<dwarf::Attribute> Attrs) const {
   // DWARF. This corresponds to following the DW_AT_abstract_origin and
   // DW_AT_specification just once.
   SmallSet<DWARFDie, 3> Seen;
+  Seen.insert(*this);
 
   while (!Worklist.empty()) {
     DWARFDie Die = Worklist.back();
@@ -411,19 +405,16 @@ DWARFDie::findRecursively(ArrayRef<dwarf::Attribute> Attrs) const {
     if (!Die.isValid())
       continue;
 
-    if (Seen.count(Die))
-      continue;
-
-    Seen.insert(Die);
-
     if (auto Value = Die.find(Attrs))
       return Value;
 
     if (auto D = Die.getAttributeValueAsReferencedDie(DW_AT_abstract_origin))
-      Worklist.push_back(D);
+      if (Seen.insert(D).second)
+        Worklist.push_back(D);
 
     if (auto D = Die.getAttributeValueAsReferencedDie(DW_AT_specification))
-      Worklist.push_back(D);
+      if (Seen.insert(D).second)
+        Worklist.push_back(D);
   }
 
   return None;
@@ -438,9 +429,11 @@ DWARFDie::getAttributeValueAsReferencedDie(dwarf::Attribute Attr) const {
 
 DWARFDie
 DWARFDie::getAttributeValueAsReferencedDie(const DWARFFormValue &V) const {
-  if (auto SpecRef = toReference(V)) {
-    if (auto SpecUnit = U->getUnitVector().getUnitForOffset(*SpecRef))
-      return SpecUnit->getDIEForOffset(*SpecRef);
+  if (auto SpecRef = V.getAsRelativeReference()) {
+    if (SpecRef->Unit)
+      return SpecRef->Unit->getDIEForOffset(SpecRef->Unit->getOffset() + SpecRef->Offset);
+    if (auto SpecUnit = U->getUnitVector().getUnitForOffset(SpecRef->Offset))
+      return SpecUnit->getDIEForOffset(SpecRef->Offset);
   }
   return DWARFDie();
 }
@@ -560,10 +553,12 @@ void DWARFDie::getCallerFrame(uint32_t &CallFile, uint32_t &CallLine,
 
 /// Helper to dump a DIE with all of its parents, but no siblings.
 static unsigned dumpParentChain(DWARFDie Die, raw_ostream &OS, unsigned Indent,
-                                DIDumpOptions DumpOpts) {
+                                DIDumpOptions DumpOpts, unsigned Depth = 0) {
   if (!Die)
     return Indent;
-  Indent = dumpParentChain(Die.getParent(), OS, Indent, DumpOpts);
+  if (DumpOpts.ParentRecurseDepth > 0 && Depth >= DumpOpts.ParentRecurseDepth)
+    return Indent;
+  Indent = dumpParentChain(Die.getParent(), OS, Indent, DumpOpts, Depth + 1);
   Die.dump(OS, Indent, DumpOpts);
   return Indent + 2;
 }
@@ -611,8 +606,8 @@ void DWARFDie::dump(raw_ostream &OS, unsigned Indent,
         }
 
         DWARFDie child = getFirstChild();
-        if (DumpOpts.ShowChildren && DumpOpts.RecurseDepth > 0 && child) {
-          DumpOpts.RecurseDepth--;
+        if (DumpOpts.ShowChildren && DumpOpts.ChildRecurseDepth > 0 && child) {
+          DumpOpts.ChildRecurseDepth--;
           DIDumpOptions ChildDumpOpts = DumpOpts;
           ChildDumpOpts.ShowParents = false;
           while (child) {
@@ -668,7 +663,7 @@ iterator_range<DWARFDie::attribute_iterator> DWARFDie::attributes() const {
 }
 
 DWARFDie::attribute_iterator::attribute_iterator(DWARFDie D, bool End)
-    : Die(D), AttrValue(0), Index(0) {
+    : Die(D), Index(0) {
   auto AbbrDecl = Die.getAbbreviationDeclarationPtr();
   assert(AbbrDecl && "Must have abbreviation declaration");
   if (End) {
@@ -690,18 +685,15 @@ void DWARFDie::attribute_iterator::updateForIndex(
     AttrValue.Attr = AbbrDecl.getAttrByIndex(Index);
     // Add the previous byte size of any previous attribute value.
     AttrValue.Offset += AttrValue.ByteSize;
-    AttrValue.Value.setForm(AbbrDecl.getFormByIndex(Index));
     uint32_t ParseOffset = AttrValue.Offset;
     auto U = Die.getDwarfUnit();
     assert(U && "Die must have valid DWARF unit");
-    bool b = AttrValue.Value.extractValue(U->getDebugInfoExtractor(),
-                                          &ParseOffset, U->getFormParams(), U);
-    (void)b;
-    assert(b && "extractValue cannot fail on fully parsed DWARF");
+    AttrValue.Value = DWARFFormValue::createFromUnit(
+        AbbrDecl.getFormByIndex(Index), U, &ParseOffset);
     AttrValue.ByteSize = ParseOffset - AttrValue.Offset;
   } else {
     assert(Index == NumAttrs && "Indexes should be [0, NumAttrs) only");
-    AttrValue.clear();
+    AttrValue = {};
   }
 }
 
@@ -710,3 +702,39 @@ DWARFDie::attribute_iterator &DWARFDie::attribute_iterator::operator++() {
     updateForIndex(*AbbrDecl, Index + 1);
   return *this;
 }
+
+bool DWARFAttribute::mayHaveLocationDescription(dwarf::Attribute Attr) {
+  switch (Attr) {
+  // From the DWARF v5 specification.
+  case DW_AT_location:
+  case DW_AT_byte_size:
+  case DW_AT_bit_size:
+  case DW_AT_string_length:
+  case DW_AT_lower_bound:
+  case DW_AT_return_addr:
+  case DW_AT_bit_stride:
+  case DW_AT_upper_bound:
+  case DW_AT_count:
+  case DW_AT_data_member_location:
+  case DW_AT_frame_base:
+  case DW_AT_segment:
+  case DW_AT_static_link:
+  case DW_AT_use_location:
+  case DW_AT_vtable_elem_location:
+  case DW_AT_allocated:
+  case DW_AT_associated:
+  case DW_AT_byte_stride:
+  case DW_AT_rank:
+  case DW_AT_call_value:
+  case DW_AT_call_origin:
+  case DW_AT_call_target:
+  case DW_AT_call_target_clobbered:
+  case DW_AT_call_data_location:
+  case DW_AT_call_data_value:
+  // Extensions.
+  case DW_AT_GNU_call_site_value:
+    return true;
+  default:
+    return false;
+  }
+}
diff --git a/lib/DebugInfo/DWARF/DWARFExpression.cpp b/lib/DebugInfo/DWARF/DWARFExpression.cpp
index 2df4456053fb..470d4b5364b4 100644
--- a/lib/DebugInfo/DWARF/DWARFExpression.cpp
+++ b/lib/DebugInfo/DWARF/DWARFExpression.cpp
@@ -1,13 +1,13 @@
 //===-- DWARFExpression.cpp -----------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/DebugInfo/DWARF/DWARFExpression.h"
+#include "llvm/DebugInfo/DWARF/DWARFUnit.h"
 #include "llvm/BinaryFormat/Dwarf.h"
 #include "llvm/MC/MCRegisterInfo.h"
 #include "llvm/Support/Format.h"
@@ -97,6 +97,11 @@ static DescVector getDescriptions() {
   Descriptions[DW_OP_addrx] = Desc(Op::Dwarf4, Op::SizeLEB);
   Descriptions[DW_OP_GNU_addr_index] = Desc(Op::Dwarf4, Op::SizeLEB);
   Descriptions[DW_OP_GNU_const_index] = Desc(Op::Dwarf4, Op::SizeLEB);
+  Descriptions[DW_OP_GNU_entry_value] = Desc(Op::Dwarf4, Op::SizeLEB);
+
+  Descriptions[DW_OP_convert] = Desc(Op::Dwarf5, Op::BaseTypeRef);
+  Descriptions[DW_OP_entry_value] = Desc(Op::Dwarf5, Op::SizeLEB);
+
   return Descriptions;
 }
 
@@ -152,17 +157,21 @@ bool DWARFExpression::Operation::extract(DataExtractor Data, uint16_t Version,
     case Operation::SizeAddr:
       if (AddressSize == 8) {
         Operands[Operand] = Data.getU64(&Offset);
-      } else {
-        assert(AddressSize == 4);
+      } else if (AddressSize == 4) {
         Operands[Operand] = Data.getU32(&Offset);
+      } else {
+        assert(AddressSize == 2);
+        Operands[Operand] = Data.getU16(&Offset);
       }
       break;
     case Operation::SizeRefAddr:
       if (getRefAddrSize(AddressSize, Version) == 8) {
         Operands[Operand] = Data.getU64(&Offset);
-      } else {
-        assert(getRefAddrSize(AddressSize, Version) == 4);
+      } else if (getRefAddrSize(AddressSize, Version) == 4) {
         Operands[Operand] = Data.getU32(&Offset);
+      } else {
+        assert(getRefAddrSize(AddressSize, Version) == 2);
+        Operands[Operand] = Data.getU16(&Offset);
       }
       break;
     case Operation::SizeLEB:
@@ -171,6 +180,9 @@ bool DWARFExpression::Operation::extract(DataExtractor Data, uint16_t Version,
       else
         Operands[Operand] = Data.getULEB128(&Offset);
       break;
+    case Operation::BaseTypeRef:
+      Operands[Operand] = Data.getULEB128(&Offset);
+      break;
     case Operation::SizeBlock:
       // We need a size, so this cannot be the first operand
       if (Operand == 0)
@@ -182,6 +194,8 @@ bool DWARFExpression::Operation::extract(DataExtractor Data, uint16_t Version,
     default:
       llvm_unreachable("Unknown DWARFExpression Op size");
     }
+
+    OperandEndOffsets[Operand] = Offset;
   }
 
   EndOffset = Offset;
@@ -222,6 +236,7 @@ static bool prettyPrintRegisterOp(raw_ostream &OS, uint8_t Opcode,
 bool DWARFExpression::Operation::print(raw_ostream &OS,
                                        const DWARFExpression *Expr,
                                        const MCRegisterInfo *RegInfo,
+                                       DWARFUnit *U,
                                        bool isEH) {
   if (Error) {
     OS << "<decoding error>";
@@ -245,14 +260,25 @@ bool DWARFExpression::Operation::print(raw_ostream &OS,
     if (Size == Operation::SizeNA)
       break;
 
-    if (Size == Operation::SizeBlock) {
+    if (Size == Operation::BaseTypeRef && U) {
+      auto Die = U->getDIEForOffset(U->getOffset() + Operands[Operand]);
+      if (Die && Die.getTag() == dwarf::DW_TAG_base_type) {
+        OS << format(" (0x%08x)", U->getOffset() + Operands[Operand]);
+        if (auto Name = Die.find(dwarf::DW_AT_name))
+          OS << " \"" << Name->getAsCString() << "\"";
+      } else {
+        OS << format(" <invalid base_type ref: 0x%" PRIx64 ">",
+                     Operands[Operand]);
+      }
+    } else if (Size == Operation::SizeBlock) {
       uint32_t Offset = Operands[Operand];
       for (unsigned i = 0; i < Operands[Operand - 1]; ++i)
         OS << format(" 0x%02x", Expr->Data.getU8(&Offset));
     } else {
       if (Signed)
         OS << format(" %+" PRId64, (int64_t)Operands[Operand]);
-      else
+      else if (Opcode != DW_OP_entry_value &&
+               Opcode != DW_OP_GNU_entry_value)
         OS << format(" 0x%" PRIx64, Operands[Operand]);
     }
   }
@@ -260,17 +286,60 @@ bool DWARFExpression::Operation::print(raw_ostream &OS,
 }
 
 void DWARFExpression::print(raw_ostream &OS, const MCRegisterInfo *RegInfo,
-                            bool IsEH) const {
+                            DWARFUnit *U, bool IsEH) const {
+  uint32_t EntryValExprSize = 0;
   for (auto &Op : *this) {
-    if (!Op.print(OS, this, RegInfo, IsEH)) {
+    if (!Op.print(OS, this, RegInfo, U, IsEH)) {
       uint32_t FailOffset = Op.getEndOffset();
       while (FailOffset < Data.getData().size())
         OS << format(" %02x", Data.getU8(&FailOffset));
       return;
     }
+
+    if (Op.getCode() == DW_OP_entry_value ||
+        Op.getCode() == DW_OP_GNU_entry_value) {
+      OS << "(";
+      EntryValExprSize = Op.getRawOperand(0);
+      continue;
+    }
+
+    if (EntryValExprSize) {
+      EntryValExprSize--;
+      if (EntryValExprSize == 0)
+        OS << ")";
+    }
+
     if (Op.getEndOffset() < Data.getData().size())
       OS << ", ";
   }
 }
 
+bool DWARFExpression::Operation::verify(DWARFUnit *U) {
+
+  for (unsigned Operand = 0; Operand < 2; ++Operand) {
+    unsigned Size = Desc.Op[Operand];
+
+    if (Size == Operation::SizeNA)
+      break;
+
+    if (Size == Operation::BaseTypeRef) {
+      auto Die = U->getDIEForOffset(U->getOffset() + Operands[Operand]);
+      if (!Die || Die.getTag() != dwarf::DW_TAG_base_type) {
+        Error = true;
+        return false;
+      }
+    }
+  }
+
+  return true;
+}
+
+bool DWARFExpression::verify(DWARFUnit *U) {
+  for (auto &Op : *this)
+    if (!Op.verify(U))
+      return false;
+
+  return true;
+}
+
 } // namespace llvm
diff --git a/lib/DebugInfo/DWARF/DWARFFormValue.cpp b/lib/DebugInfo/DWARF/DWARFFormValue.cpp
index 7719fea63120..290d35511cdb 100644
--- a/lib/DebugInfo/DWARF/DWARFFormValue.cpp
+++ b/lib/DebugInfo/DWARF/DWARFFormValue.cpp
@@ -1,9 +1,8 @@
 //===- DWARFFormValue.cpp -------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
@@ -78,6 +77,34 @@ static const DWARFFormValue::FormClass DWARF5FormClasses[] = {
 
 };
 
+DWARFFormValue DWARFFormValue::createFromSValue(dwarf::Form F, int64_t V) {
+  return DWARFFormValue(F, ValueType(V));
+}
+
+DWARFFormValue DWARFFormValue::createFromUValue(dwarf::Form F, uint64_t V) {
+  return DWARFFormValue(F, ValueType(V));
+}
+
+DWARFFormValue DWARFFormValue::createFromPValue(dwarf::Form F, const char *V) {
+  return DWARFFormValue(F, ValueType(V));
+}
+
+DWARFFormValue DWARFFormValue::createFromBlockValue(dwarf::Form F,
+                                                    ArrayRef<uint8_t> D) {
+  ValueType V;
+  V.uval = D.size();
+  V.data = D.data();
+  return DWARFFormValue(F, V);
+}
+
+DWARFFormValue DWARFFormValue::createFromUnit(dwarf::Form F, const DWARFUnit *U,
+                                              uint32_t *OffsetPtr) {
+  DWARFFormValue FormValue(F);
+  FormValue.extractValue(U->getDebugInfoExtractor(), OffsetPtr,
+                         U->getFormParams(), U);
+  return FormValue;
+}
+
 bool DWARFFormValue::skipValue(dwarf::Form Form, DataExtractor DebugInfoData,
                                uint32_t *OffsetPtr,
                                const dwarf::FormParams Params) {
@@ -193,13 +220,17 @@ bool DWARFFormValue::isFormClass(DWARFFormValue::FormClass FC) const {
   default:
     break;
   }
-  // In DWARF3 DW_FORM_data4 and DW_FORM_data8 served also as a section offset.
-  // Don't check for DWARF version here, as some producers may still do this
-  // by mistake. Also accept DW_FORM_[line_]strp since these are
-  // .debug_[line_]str section offsets.
-  return (Form == DW_FORM_data4 || Form == DW_FORM_data8 ||
-          Form == DW_FORM_strp || Form == DW_FORM_line_strp) &&
-         FC == FC_SectionOffset;
+
+  if (FC == FC_SectionOffset) {
+    if (Form == DW_FORM_strp || Form == DW_FORM_line_strp)
+      return true;
+    // In DWARF3 DW_FORM_data4 and DW_FORM_data8 served also as a section
+    // offset. If we don't have a DWARFUnit, default to the old behavior.
+    if (Form == DW_FORM_data4 || Form == DW_FORM_data8)
+      return !U || U->getVersion() <= 3;
+  }
+
+  return false;
 }
 
 bool DWARFFormValue::extractValue(const DWARFDataExtractor &Data,
@@ -268,7 +299,7 @@ bool DWARFFormValue::extractValue(const DWARFDataExtractor &Data,
     case DW_FORM_data8:
     case DW_FORM_ref8:
     case DW_FORM_ref_sup8:
-      Value.uval = Data.getU64(OffsetPtr);
+      Value.uval = Data.getRelocatedValue(8, OffsetPtr);
       break;
     case DW_FORM_data16:
       // Treat this like a 16-byte block.
@@ -323,7 +354,7 @@ bool DWARFFormValue::extractValue(const DWARFDataExtractor &Data,
     StringRef Str = Data.getData().substr(*OffsetPtr, Value.uval);
     Value.data = nullptr;
     if (!Str.empty()) {
-      Value.data = reinterpret_cast<const uint8_t *>(Str.data());
+      Value.data = Str.bytes_begin();
       *OffsetPtr += Value.uval;
     }
   }
@@ -333,7 +364,7 @@ bool DWARFFormValue::extractValue(const DWARFDataExtractor &Data,
 
 void DWARFFormValue::dumpSectionedAddress(raw_ostream &OS,
                                           DIDumpOptions DumpOpts,
-                                          SectionedAddress SA) const {
+                                          object::SectionedAddress SA) const {
   OS << format("0x%016" PRIx64, SA.Address);
   dumpAddressSection(U->getContext().getDWARFObj(), OS, DumpOpts,
                      SA.SectionIndex);
@@ -370,12 +401,14 @@ void DWARFFormValue::dump(raw_ostream &OS, DIDumpOptions DumpOpts) const {
   case DW_FORM_addrx3:
   case DW_FORM_addrx4:
   case DW_FORM_GNU_addr_index: {
-    Optional<SectionedAddress> A = U->getAddrOffsetSectionItem(UValue);
+    if (U == nullptr) {
+      OS << "<invalid dwarf unit>";
+      break;
+    }
+    Optional<object::SectionedAddress> A = U->getAddrOffsetSectionItem(UValue);
     if (!A || DumpOpts.Verbose)
       AddrOS << format("indexed (%8.8x) address = ", (uint32_t)UValue);
-    if (U == nullptr)
-      OS << "<invalid dwarf unit>";
-    else if (A)
+    if (A)
       dumpSectionedAddress(AddrOS, DumpOpts, *A);
     else
       OS << "<no .debug_addr section>";
@@ -591,14 +624,15 @@ Optional<uint64_t> DWARFFormValue::getAsAddress() const {
     return SA->Address;
   return None;
 }
-Optional<SectionedAddress> DWARFFormValue::getAsSectionedAddress() const {
+Optional<object::SectionedAddress>
+DWARFFormValue::getAsSectionedAddress() const {
   if (!isFormClass(FC_Address))
     return None;
   if (Form == DW_FORM_GNU_addr_index || Form == DW_FORM_addrx) {
     uint32_t Index = Value.uval;
     if (!U)
       return None;
-    Optional<SectionedAddress> SA = U->getAddrOffsetSectionItem(Index);
+    Optional<object::SectionedAddress> SA = U->getAddrOffsetSectionItem(Index);
     if (!SA)
       return None;
     return SA;
@@ -607,6 +641,12 @@ Optional<SectionedAddress> DWARFFormValue::getAsSectionedAddress() const {
 }
 
 Optional<uint64_t> DWARFFormValue::getAsReference() const {
+  if (auto R = getAsRelativeReference())
+    return R->Unit ? R->Unit->getOffset() + R->Offset : R->Offset;
+  return None;
+}
+  
+Optional<DWARFFormValue::UnitOffset> DWARFFormValue::getAsRelativeReference() const {
   if (!isFormClass(FC_Reference))
     return None;
   switch (Form) {
@@ -617,11 +657,11 @@ Optional<uint64_t> DWARFFormValue::getAsReference() const {
   case DW_FORM_ref_udata:
     if (!U)
       return None;
-    return Value.uval + U->getOffset();
+    return UnitOffset{const_cast<DWARFUnit*>(U), Value.uval};
   case DW_FORM_ref_addr:
   case DW_FORM_ref_sig8:
   case DW_FORM_GNU_ref_alt:
-    return Value.uval;
+    return UnitOffset{nullptr, Value.uval};
   default:
     return None;
   }
diff --git a/lib/DebugInfo/DWARF/DWARFGdbIndex.cpp b/lib/DebugInfo/DWARF/DWARFGdbIndex.cpp
index 1abd931e3b8b..f5f975578082 100644
--- a/lib/DebugInfo/DWARF/DWARFGdbIndex.cpp
+++ b/lib/DebugInfo/DWARF/DWARFGdbIndex.cpp
@@ -1,9 +1,8 @@
 //===- DWARFGdbIndex.cpp --------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
@@ -121,7 +120,7 @@ bool DWARFGdbIndex::parseImpl(DataExtractor Data) {
     return false;
 
   CuListOffset = Data.getU32(&Offset);
-  uint32_t CuTypesOffset = Data.getU32(&Offset);
+  TuListOffset = Data.getU32(&Offset);
   AddressAreaOffset = Data.getU32(&Offset);
   SymbolTableOffset = Data.getU32(&Offset);
   ConstantPoolOffset = Data.getU32(&Offset);
@@ -129,7 +128,7 @@ bool DWARFGdbIndex::parseImpl(DataExtractor Data) {
   if (Offset != CuListOffset)
     return false;
 
-  uint32_t CuListSize = (CuTypesOffset - CuListOffset) / 16;
+  uint32_t CuListSize = (TuListOffset - CuListOffset) / 16;
   CuList.reserve(CuListSize);
   for (uint32_t i = 0; i < CuListSize; ++i) {
     uint64_t CuOffset = Data.getU64(&Offset);
@@ -139,7 +138,7 @@ bool DWARFGdbIndex::parseImpl(DataExtractor Data) {
 
   // CU Types are no longer needed as DWARF skeleton type units never made it
   // into the standard.
-  uint32_t TuListSize = (AddressAreaOffset - CuTypesOffset) / 24;
+  uint32_t TuListSize = (AddressAreaOffset - TuListOffset) / 24;
   TuList.resize(TuListSize);
   for (uint32_t I = 0; I < TuListSize; ++I) {
     uint64_t CuOffset = Data.getU64(&Offset);
diff --git a/lib/DebugInfo/DWARF/DWARFListTable.cpp b/lib/DebugInfo/DWARF/DWARFListTable.cpp
index 462c036d73ad..e38e706227da 100644
--- a/lib/DebugInfo/DWARF/DWARFListTable.cpp
+++ b/lib/DebugInfo/DWARF/DWARFListTable.cpp
@@ -1,9 +1,8 @@
 //===- DWARFListTable.cpp ---------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
@@ -26,7 +25,7 @@ Error DWARFListTableHeader::extract(DWARFDataExtractor Data,
                        "%s table length at offset 0x%" PRIx32,
                        SectionName.data(), *OffsetPtr);
   // TODO: Add support for DWARF64.
-  HeaderData.Length = Data.getU32(OffsetPtr);
+  HeaderData.Length = Data.getRelocatedValue(4, OffsetPtr);
   if (HeaderData.Length == 0xffffffffu)
     return createStringError(errc::not_supported,
                        "DWARF64 is not supported in %s at offset 0x%" PRIx32,
@@ -74,7 +73,7 @@ Error DWARFListTableHeader::extract(DWARFDataExtractor Data,
         SectionName.data(), HeaderOffset, HeaderData.OffsetEntryCount);
   Data.setAddressSize(HeaderData.AddrSize);
   for (uint32_t I = 0; I < HeaderData.OffsetEntryCount; ++I)
-    Offsets.push_back(Data.getU32(OffsetPtr));
+    Offsets.push_back(Data.getRelocatedValue(4, OffsetPtr));
   return Error::success();
 }
 
diff --git a/lib/DebugInfo/DWARF/DWARFTypeUnit.cpp b/lib/DebugInfo/DWARF/DWARFTypeUnit.cpp
index 00be75e1a94d..844920ba5b11 100644
--- a/lib/DebugInfo/DWARF/DWARFTypeUnit.cpp
+++ b/lib/DebugInfo/DWARF/DWARFTypeUnit.cpp
@@ -1,9 +1,8 @@
 //===- DWARFTypeUnit.cpp --------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
diff --git a/lib/DebugInfo/DWARF/DWARFUnit.cpp b/lib/DebugInfo/DWARF/DWARFUnit.cpp
index 80234665bdeb..b74acf60c747 100644
--- a/lib/DebugInfo/DWARF/DWARFUnit.cpp
+++ b/lib/DebugInfo/DWARF/DWARFUnit.cpp
@@ -1,9 +1,8 @@
 //===- DWARFUnit.cpp ------------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
@@ -198,7 +197,7 @@ DWARFDataExtractor DWARFUnit::getDebugInfoExtractor() const {
                             getAddressByteSize());
 }
 
-Optional<SectionedAddress>
+Optional<object::SectionedAddress>
 DWARFUnit::getAddrOffsetSectionItem(uint32_t Index) const {
   if (IsDWO) {
     auto R = Context.info_section_units();
@@ -242,17 +241,21 @@ bool DWARFUnitHeader::extract(DWARFContext &Context,
   IndexEntry = Entry;
   if (!IndexEntry && Index)
     IndexEntry = Index->getFromOffset(*offset_ptr);
-  Length = debug_info.getU32(offset_ptr);
-  // FIXME: Support DWARF64.
-  unsigned SizeOfLength = 4;
+  Length = debug_info.getRelocatedValue(4, offset_ptr);
   FormParams.Format = DWARF32;
+  unsigned SizeOfLength = 4;
+  if (Length == 0xffffffff) {
+    Length = debug_info.getU64(offset_ptr);
+    FormParams.Format = DWARF64;
+    SizeOfLength = 8;
+  }
   FormParams.Version = debug_info.getU16(offset_ptr);
   if (FormParams.Version >= 5) {
     UnitType = debug_info.getU8(offset_ptr);
     FormParams.AddrSize = debug_info.getU8(offset_ptr);
-    AbbrOffset = debug_info.getU32(offset_ptr);
+    AbbrOffset = debug_info.getRelocatedValue(FormParams.getDwarfOffsetByteSize(), offset_ptr);
   } else {
-    AbbrOffset = debug_info.getRelocatedValue(4, offset_ptr);
+    AbbrOffset = debug_info.getRelocatedValue(FormParams.getDwarfOffsetByteSize(), offset_ptr);
     FormParams.AddrSize = debug_info.getU8(offset_ptr);
     // Fake a unit type based on the section type.  This isn't perfect,
     // but distinguishing compile and type units is generally enough.
@@ -432,12 +435,17 @@ size_t DWARFUnit::extractDIEsIfNeeded(bool CUDieOnly) {
     // which may differ from the unit's format.
     DWARFDataExtractor DA(Context.getDWARFObj(), StringOffsetSection,
                           isLittleEndian, 0);
-    if (IsDWO)
-      StringOffsetsTableContribution =
-          determineStringOffsetsTableContributionDWO(DA);
-    else if (getVersion() >= 5)
-      StringOffsetsTableContribution =
-          determineStringOffsetsTableContribution(DA);
+    if (IsDWO || getVersion() >= 5) {
+      auto StringOffsetOrError =
+          IsDWO ? determineStringOffsetsTableContributionDWO(DA)
+                : determineStringOffsetsTableContribution(DA);
+      if (!StringOffsetOrError) {
+        WithColor::error() << "invalid contribution to string offsets table in section .debug_str_offsets[.dwo]: "
+                           << toString(StringOffsetOrError.takeError()) << '\n';
+      } else {
+        StringOffsetsTableContribution = *StringOffsetOrError;
+      }
+    }
 
     // DWARF v5 uses the .debug_rnglists and .debug_rnglists.dwo sections to
     // describe address ranges.
@@ -634,7 +642,7 @@ DWARFUnit::getInlinedChainForAddress(uint64_t Address,
   // First, find the subroutine that contains the given address (the leaf
   // of inlined chain).
   DWARFDie SubroutineDIE =
-      (DWO ? DWO.get() : this)->getSubroutineForAddress(Address);
+      (DWO ? *DWO : *this).getSubroutineForAddress(Address);
 
   if (!SubroutineDIE)
     return;
@@ -745,7 +753,7 @@ const DWARFAbbreviationDeclarationSet *DWARFUnit::getAbbreviations() const {
   return Abbrevs;
 }
 
-llvm::Optional<SectionedAddress> DWARFUnit::getBaseAddress() {
+llvm::Optional<object::SectionedAddress> DWARFUnit::getBaseAddress() {
   if (BaseAddr)
     return BaseAddr;
 
@@ -755,7 +763,7 @@ llvm::Optional<SectionedAddress> DWARFUnit::getBaseAddress() {
   return BaseAddr;
 }
 
-Optional<StrOffsetsContributionDescriptor>
+Expected<StrOffsetsContributionDescriptor>
 StrOffsetsContributionDescriptor::validateContributionSize(
     DWARFDataExtractor &DA) {
   uint8_t EntrySize = getDwarfOffsetByteSize();
@@ -766,58 +774,94 @@ StrOffsetsContributionDescriptor::validateContributionSize(
   if (ValidationSize >= Size)
     if (DA.isValidOffsetForDataOfSize((uint32_t)Base, ValidationSize))
       return *this;
-  return None;
+  return createStringError(errc::invalid_argument, "length exceeds section size");
 }
 
 // Look for a DWARF64-formatted contribution to the string offsets table
 // starting at a given offset and record it in a descriptor.
-static Optional<StrOffsetsContributionDescriptor>
+static Expected<StrOffsetsContributionDescriptor>
 parseDWARF64StringOffsetsTableHeader(DWARFDataExtractor &DA, uint32_t Offset) {
   if (!DA.isValidOffsetForDataOfSize(Offset, 16))
-    return None;
+    return createStringError(errc::invalid_argument, "section offset exceeds section size");
 
   if (DA.getU32(&Offset) != 0xffffffff)
-    return None;
+    return createStringError(errc::invalid_argument, "32 bit contribution referenced from a 64 bit unit");
 
   uint64_t Size = DA.getU64(&Offset);
   uint8_t Version = DA.getU16(&Offset);
   (void)DA.getU16(&Offset); // padding
   // The encoded length includes the 2-byte version field and the 2-byte
   // padding, so we need to subtract them out when we populate the descriptor.
-  return {{Offset, Size - 4, Version, DWARF64}};
+  return StrOffsetsContributionDescriptor(Offset, Size - 4, Version, DWARF64);
 }
 
 // Look for a DWARF32-formatted contribution to the string offsets table
 // starting at a given offset and record it in a descriptor.
-static Optional<StrOffsetsContributionDescriptor>
+static Expected<StrOffsetsContributionDescriptor>
 parseDWARF32StringOffsetsTableHeader(DWARFDataExtractor &DA, uint32_t Offset) {
   if (!DA.isValidOffsetForDataOfSize(Offset, 8))
-    return None;
+    return createStringError(errc::invalid_argument, "section offset exceeds section size");
+
   uint32_t ContributionSize = DA.getU32(&Offset);
   if (ContributionSize >= 0xfffffff0)
-    return None;
+    return createStringError(errc::invalid_argument, "invalid length");
+
   uint8_t Version = DA.getU16(&Offset);
   (void)DA.getU16(&Offset); // padding
   // The encoded length includes the 2-byte version field and the 2-byte
   // padding, so we need to subtract them out when we populate the descriptor.
-  return {{Offset, ContributionSize - 4, Version, DWARF32}};
+  return StrOffsetsContributionDescriptor(Offset, ContributionSize - 4, Version,
+                                          DWARF32);
+}
+
+static Expected<StrOffsetsContributionDescriptor>
+parseDWARFStringOffsetsTableHeader(DWARFDataExtractor &DA,
+                                   llvm::dwarf::DwarfFormat Format,
+                                   uint64_t Offset) {
+  StrOffsetsContributionDescriptor Desc;
+  switch (Format) {
+  case dwarf::DwarfFormat::DWARF64: {
+    if (Offset < 16)
+      return createStringError(errc::invalid_argument, "insufficient space for 64 bit header prefix");
+    auto DescOrError = parseDWARF64StringOffsetsTableHeader(DA, (uint32_t)Offset - 16);
+    if (!DescOrError)
+      return DescOrError.takeError();
+    Desc = *DescOrError;
+    break;
+  }
+  case dwarf::DwarfFormat::DWARF32: {
+    if (Offset < 8)
+      return createStringError(errc::invalid_argument, "insufficient space for 32 bit header prefix");
+    auto DescOrError = parseDWARF32StringOffsetsTableHeader(DA, (uint32_t)Offset - 8);
+    if (!DescOrError)
+      return DescOrError.takeError();
+    Desc = *DescOrError;
+    break;
+  }
+  }
+  return Desc.validateContributionSize(DA);
 }
 
-Optional<StrOffsetsContributionDescriptor>
+Expected<Optional<StrOffsetsContributionDescriptor>>
 DWARFUnit::determineStringOffsetsTableContribution(DWARFDataExtractor &DA) {
-  auto Offset = toSectionOffset(getUnitDIE().find(DW_AT_str_offsets_base), 0);
-  Optional<StrOffsetsContributionDescriptor> Descriptor;
-  // Attempt to find a DWARF64 contribution 16 bytes before the base.
-  if (Offset >= 16)
-    Descriptor =
-        parseDWARF64StringOffsetsTableHeader(DA, (uint32_t)Offset - 16);
-  // Try to find a DWARF32 contribution 8 bytes before the base.
-  if (!Descriptor && Offset >= 8)
-    Descriptor = parseDWARF32StringOffsetsTableHeader(DA, (uint32_t)Offset - 8);
-  return Descriptor ? Descriptor->validateContributionSize(DA) : Descriptor;
-}
-
-Optional<StrOffsetsContributionDescriptor>
+  uint64_t Offset;
+  if (IsDWO) {
+    Offset = 0;
+    if (DA.getData().data() == nullptr)
+      return None;
+  } else {
+    auto OptOffset = toSectionOffset(getUnitDIE().find(DW_AT_str_offsets_base));
+    if (!OptOffset)
+      return None;
+    Offset = *OptOffset;
+  }
+  auto DescOrError = parseDWARFStringOffsetsTableHeader(DA, Header.getFormat(), Offset);
+  if (!DescOrError)
+    return DescOrError.takeError();
+  return *DescOrError;
+}
+
+Expected<Optional<StrOffsetsContributionDescriptor>>
 DWARFUnit::determineStringOffsetsTableContributionDWO(DWARFDataExtractor & DA) {
   uint64_t Offset = 0;
   auto IndexEntry = Header.getIndexEntry();
@@ -826,19 +870,24 @@ DWARFUnit::determineStringOffsetsTableContributionDWO(DWARFDataExtractor & DA) {
   if (C)
     Offset = C->Offset;
   if (getVersion() >= 5) {
+    if (DA.getData().data() == nullptr)
+      return None;
+    Offset += Header.getFormat() == dwarf::DwarfFormat::DWARF32 ? 8 : 16;
     // Look for a valid contribution at the given offset.
-    auto Descriptor =
-        parseDWARF64StringOffsetsTableHeader(DA, (uint32_t)Offset);
-    if (!Descriptor)
-      Descriptor = parseDWARF32StringOffsetsTableHeader(DA, (uint32_t)Offset);
-    return Descriptor ? Descriptor->validateContributionSize(DA) : Descriptor;
+    auto DescOrError = parseDWARFStringOffsetsTableHeader(DA, Header.getFormat(), Offset);
+    if (!DescOrError)
+      return DescOrError.takeError();
+    return *DescOrError;
   }
   // Prior to DWARF v5, we derive the contribution size from the
   // index table (in a package file). In a .dwo file it is simply
   // the length of the string offsets section.
   if (!IndexEntry)
-    return {{0, StringOffsetSection.Data.size(), 4, DWARF32}};
+    return {
+        Optional<StrOffsetsContributionDescriptor>(
+            {0, StringOffsetSection.Data.size(), 4, DWARF32})};
   if (C)
-    return {{C->Offset, C->Length, 4, DWARF32}};
+    return {Optional<StrOffsetsContributionDescriptor>(
+        {C->Offset, C->Length, 4, DWARF32})};
   return None;
 }
diff --git a/lib/DebugInfo/DWARF/DWARFUnitIndex.cpp b/lib/DebugInfo/DWARF/DWARFUnitIndex.cpp
index 84b6c4b81817..047c63461ccf 100644
--- a/lib/DebugInfo/DWARF/DWARFUnitIndex.cpp
+++ b/lib/DebugInfo/DWARF/DWARFUnitIndex.cpp
@@ -1,9 +1,8 @@
 //===- DWARFUnitIndex.cpp -------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
@@ -173,10 +172,9 @@ DWARFUnitIndex::getFromOffset(uint32_t Offset) const {
              E2->Contributions[InfoColumn].Offset;
     });
   }
-  auto I =
-      llvm::upper_bound(OffsetLookup, Offset, [&](uint32_t Offset, Entry *E2) {
-        return Offset < E2->Contributions[InfoColumn].Offset;
-      });
+  auto I = partition_point(OffsetLookup, [&](Entry *E2) {
+    return E2->Contributions[InfoColumn].Offset <= Offset;
+  });
   if (I == OffsetLookup.begin())
     return nullptr;
   --I;
diff --git a/lib/DebugInfo/DWARF/DWARFVerifier.cpp b/lib/DebugInfo/DWARF/DWARFVerifier.cpp
index f8370178b627..c2b3189514a8 100644
--- a/lib/DebugInfo/DWARF/DWARFVerifier.cpp
+++ b/lib/DebugInfo/DWARF/DWARFVerifier.cpp
@@ -1,9 +1,8 @@
 //===- DWARFVerifier.cpp --------------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 #include "llvm/DebugInfo/DWARF/DWARFVerifier.h"
@@ -61,55 +60,47 @@ DWARFVerifier::DieRangeInfo::insert(const DieRangeInfo &RI) {
 }
 
 bool DWARFVerifier::DieRangeInfo::contains(const DieRangeInfo &RHS) const {
-  // Both list of ranges are sorted so we can make this fast.
-
-  if (Ranges.empty() || RHS.Ranges.empty())
-    return false;
-
-  // Since the ranges are sorted we can advance where we start searching with
-  // this object's ranges as we traverse RHS.Ranges.
-  auto End = Ranges.end();
-  auto Iter = findRange(RHS.Ranges.front());
+  auto I1 = Ranges.begin(), E1 = Ranges.end();
+  auto I2 = RHS.Ranges.begin(), E2 = RHS.Ranges.end();
+  if (I2 == E2)
+    return true;
 
-  // Now linearly walk the ranges in this object and see if they contain each
-  // ranges from RHS.Ranges.
-  for (const auto &R : RHS.Ranges) {
-    while (Iter != End) {
-      if (Iter->contains(R))
-        break;
-      ++Iter;
+  DWARFAddressRange R = *I2;
+  while (I1 != E1) {
+    bool Covered = I1->LowPC <= R.LowPC;
+    if (R.LowPC == R.HighPC || (Covered && R.HighPC <= I1->HighPC)) {
+      if (++I2 == E2)
+        return true;
+      R = *I2;
+      continue;
     }
-    if (Iter == End)
+    if (!Covered)
       return false;
+    if (R.LowPC < I1->HighPC)
+      R.LowPC = I1->HighPC;
+    ++I1;
   }
-  return true;
+  return false;
 }
 
 bool DWARFVerifier::DieRangeInfo::intersects(const DieRangeInfo &RHS) const {
-  if (Ranges.empty() || RHS.Ranges.empty())
-    return false;
-
-  auto End = Ranges.end();
-  auto Iter = findRange(RHS.Ranges.front());
-  for (const auto &R : RHS.Ranges) {
-    if (Iter == End)
-      return false;
-    if (R.HighPC <= Iter->LowPC)
-      continue;
-    while (Iter != End) {
-      if (Iter->intersects(R))
-        return true;
-      ++Iter;
-    }
+  auto I1 = Ranges.begin(), E1 = Ranges.end();
+  auto I2 = RHS.Ranges.begin(), E2 = RHS.Ranges.end();
+  while (I1 != E1 && I2 != E2) {
+    if (I1->intersects(*I2))
+      return true;
+    if (I1->LowPC < I2->LowPC)
+      ++I1;
+    else
+      ++I2;
   }
-
   return false;
 }
 
 bool DWARFVerifier::verifyUnitHeader(const DWARFDataExtractor DebugInfoData,
                                      uint32_t *Offset, unsigned UnitIndex,
                                      uint8_t &UnitType, bool &isUnitDWARF64) {
-  uint32_t AbbrOffset, Length;
+  uint64_t AbbrOffset, Length;
   uint8_t AddrSize = 0;
   uint16_t Version;
   bool Success = true;
@@ -123,22 +114,19 @@ bool DWARFVerifier::verifyUnitHeader(const DWARFDataExtractor DebugInfoData,
   uint32_t OffsetStart = *Offset;
   Length = DebugInfoData.getU32(Offset);
   if (Length == UINT32_MAX) {
+    Length = DebugInfoData.getU64(Offset);
     isUnitDWARF64 = true;
-    OS << format(
-        "Unit[%d] is in 64-bit DWARF format; cannot verify from this point.\n",
-        UnitIndex);
-    return false;
   }
   Version = DebugInfoData.getU16(Offset);
 
   if (Version >= 5) {
     UnitType = DebugInfoData.getU8(Offset);
     AddrSize = DebugInfoData.getU8(Offset);
-    AbbrOffset = DebugInfoData.getU32(Offset);
+    AbbrOffset = isUnitDWARF64 ? DebugInfoData.getU64(Offset) : DebugInfoData.getU32(Offset);
     ValidType = dwarf::isUnitType(UnitType);
   } else {
     UnitType = 0;
-    AbbrOffset = DebugInfoData.getU32(Offset);
+    AbbrOffset = isUnitDWARF64 ? DebugInfoData.getU64(Offset) : DebugInfoData.getU32(Offset);
     AddrSize = DebugInfoData.getU8(Offset);
   }
 
@@ -166,7 +154,7 @@ bool DWARFVerifier::verifyUnitHeader(const DWARFDataExtractor DebugInfoData,
     if (!ValidAddrSize)
       note() << "The address size is unsupported.\n";
   }
-  *Offset = OffsetStart + Length + 4;
+  *Offset = OffsetStart + Length + (isUnitDWARF64 ? 12 : 4);
   return Success;
 }
 
@@ -179,21 +167,11 @@ unsigned DWARFVerifier::verifyUnitContents(DWARFUnit &Unit) {
     if (Die.getTag() == DW_TAG_null)
       continue;
 
-    bool HasTypeAttr = false;
     for (auto AttrValue : Die.attributes()) {
       NumUnitErrors += verifyDebugInfoAttribute(Die, AttrValue);
       NumUnitErrors += verifyDebugInfoForm(Die, AttrValue);
-      HasTypeAttr |= (AttrValue.Attr == DW_AT_type);
     }
 
-    if (!HasTypeAttr && (Die.getTag() == DW_TAG_formal_parameter ||
-                         Die.getTag() == DW_TAG_variable ||
-                         Die.getTag() == DW_TAG_array_type)) {
-      error() << "DIE with tag " << TagString(Die.getTag())
-              << " is missing type attribute:\n";
-      dump(Die) << '\n';
-      NumUnitErrors++;
-    }
     NumUnitErrors += verifyDebugInfoCallSite(Die);
   }
 
@@ -281,19 +259,12 @@ bool DWARFVerifier::handleDebugAbbrev() {
   OS << "Verifying .debug_abbrev...\n";
 
   const DWARFObject &DObj = DCtx.getDWARFObj();
-  bool noDebugAbbrev = DObj.getAbbrevSection().empty();
-  bool noDebugAbbrevDWO = DObj.getAbbrevDWOSection().empty();
-
-  if (noDebugAbbrev && noDebugAbbrevDWO) {
-    return true;
-  }
-
   unsigned NumErrors = 0;
-  if (!noDebugAbbrev)
+  if (!DObj.getAbbrevSection().empty())
     NumErrors += verifyAbbrevSection(DCtx.getDebugAbbrev());
-
-  if (!noDebugAbbrevDWO)
+  if (!DObj.getAbbrevDWOSection().empty())
     NumErrors += verifyAbbrevSection(DCtx.getDebugAbbrevDWO());
+
   return NumErrors == 0;
 }
 
@@ -503,7 +474,7 @@ unsigned DWARFVerifier::verifyDebugInfoAttribute(const DWARFDie &Die,
       bool Error = llvm::any_of(Expression, [](DWARFExpression::Operation &Op) {
         return Op.isError();
       });
-      if (Error)
+      if (Error || !Expression.verify(U))
         ReportError("DIE contains invalid DWARF expression:");
     };
     if (Optional<ArrayRef<uint8_t>> Expr = AttrValue.Value.getAsBlock()) {
@@ -629,7 +600,7 @@ unsigned DWARFVerifier::verifyDebugInfoForm(const DWARFDie &Die,
       dump(Die) << '\n';
       break;
     }
-    // Check that the index is within the bounds of the section. 
+    // Check that the index is within the bounds of the section.
     unsigned ItemSize = DieCU->getDwarfStringOffsetsByteSize();
     // Use a 64-bit type to calculate the offset to guard against overflow.
     uint64_t Offset =
@@ -664,9 +635,9 @@ unsigned DWARFVerifier::verifyDebugInfoReferences() {
   // getting the DIE by offset and emitting an error
   OS << "Verifying .debug_info references...\n";
   unsigned NumErrors = 0;
-  for (auto Pair : ReferenceToDIEOffsets) {
-    auto Die = DCtx.getDIEForOffset(Pair.first);
-    if (Die)
+  for (const std::pair<uint64_t, std::set<uint32_t>> &Pair :
+       ReferenceToDIEOffsets) {
+    if (DCtx.getDIEForOffset(Pair.first))
       continue;
     ++NumErrors;
     error() << "invalid DIE reference " << format("0x%08" PRIx64, Pair.first)
@@ -731,7 +702,6 @@ void DWARFVerifier::verifyDebugLineRows() {
       continue;
 
     // Verify prologue.
-    uint32_t MaxFileIndex = LineTable->Prologue.FileNames.size();
     uint32_t MaxDirIndex = LineTable->Prologue.IncludeDirectories.size();
     uint32_t FileIndex = 1;
     StringMap<uint16_t> FullPathMap;
@@ -773,7 +743,7 @@ void DWARFVerifier::verifyDebugLineRows() {
     uint32_t RowIndex = 0;
     for (const auto &Row : LineTable->Rows) {
       // Verify row address.
-      if (Row.Address < PrevAddress) {
+      if (Row.Address.Address < PrevAddress) {
         ++NumDebugLineErrors;
         error() << ".debug_line["
                 << format("0x%08" PRIx64,
@@ -789,13 +759,16 @@ void DWARFVerifier::verifyDebugLineRows() {
       }
 
       // Verify file index.
-      if (Row.File > MaxFileIndex) {
+      if (!LineTable->hasFileAtIndex(Row.File)) {
         ++NumDebugLineErrors;
+        bool isDWARF5 = LineTable->Prologue.getVersion() >= 5;
         error() << ".debug_line["
                 << format("0x%08" PRIx64,
                           *toSectionOffset(Die.find(DW_AT_stmt_list)))
                 << "][" << RowIndex << "] has invalid file index " << Row.File
-                << " (valid values are [1," << MaxFileIndex << "]):\n";
+                << " (valid values are [" << (isDWARF5 ? "0," : "1,")
+                << LineTable->Prologue.FileNames.size()
+                << (isDWARF5 ? ")" : "]") << "):\n";
         DWARFDebugLine::Row::dumpTableHeader(OS);
         Row.dump(OS);
         OS << '\n';
@@ -803,7 +776,7 @@ void DWARFVerifier::verifyDebugLineRows() {
       if (Row.EndSequence)
         PrevAddress = 0;
       else
-        PrevAddress = Row.Address;
+        PrevAddress = Row.Address.Address;
       ++RowIndex;
     }
   }