Adding inline comments to code view type record directives for better readability

llvm-svn: 366372

2 files changed, 157 insertions, 125 deletions

diff --git a/llvm/lib/DebugInfo/CodeView/CodeViewRecordIO.cpp b/llvm/lib/DebugInfo/CodeView/CodeViewRecordIO.cpp
index 2b69a1e0768..2f49474115a 100644
--- a/llvm/lib/DebugInfo/CodeView/CodeViewRecordIO.cpp
+++ b/llvm/lib/DebugInfo/CodeView/CodeViewRecordIO.cpp
@@ -97,8 +97,10 @@ Error CodeViewRecordIO::skipPadding() {
   return Reader->skip(BytesToAdvance);
 }
 
-Error CodeViewRecordIO::mapByteVectorTail(ArrayRef<uint8_t> &Bytes) {
+Error CodeViewRecordIO::mapByteVectorTail(ArrayRef<uint8_t> &Bytes,
+                                          const Twine &Comment) {
   if (isStreaming()) {
+    emitComment(Comment);
     Streamer->EmitBinaryData(toStringRef(Bytes));
     incrStreamedLen(Bytes.size());
   } else if (isWriting()) {
@@ -111,9 +113,10 @@ Error CodeViewRecordIO::mapByteVectorTail(ArrayRef<uint8_t> &Bytes) {
   return Error::success();
 }
 
-Error CodeViewRecordIO::mapByteVectorTail(std::vector<uint8_t> &Bytes) {
+Error CodeViewRecordIO::mapByteVectorTail(std::vector<uint8_t> &Bytes,
+                                          const Twine &Comment) {
   ArrayRef<uint8_t> BytesRef(Bytes);
-  if (auto EC = mapByteVectorTail(BytesRef))
+  if (auto EC = mapByteVectorTail(BytesRef, Comment))
     return EC;
   if (!isWriting())
     Bytes.assign(BytesRef.begin(), BytesRef.end());
@@ -121,8 +124,9 @@ Error CodeViewRecordIO::mapByteVectorTail(std::vector<uint8_t> &Bytes) {
   return Error::success();
 }
 
-Error CodeViewRecordIO::mapInteger(TypeIndex &TypeInd) {
+Error CodeViewRecordIO::mapInteger(TypeIndex &TypeInd, const Twine &Comment) {
   if (isStreaming()) {
+    emitComment(Comment);
     Streamer->EmitIntValue(TypeInd.getIndex(), sizeof(TypeInd.getIndex()));
     incrStreamedLen(sizeof(TypeInd.getIndex()));
   } else if (isWriting()) {
@@ -137,12 +141,13 @@ Error CodeViewRecordIO::mapInteger(TypeIndex &TypeInd) {
   return Error::success();
 }
 
-Error CodeViewRecordIO::mapEncodedInteger(int64_t &Value) {
+Error CodeViewRecordIO::mapEncodedInteger(int64_t &Value,
+                                          const Twine &Comment) {
   if (isStreaming()) {
     if (Value >= 0)
-      emitEncodedUnsignedInteger(static_cast<uint64_t>(Value));
+      emitEncodedUnsignedInteger(static_cast<uint64_t>(Value), Comment);
     else
-      emitEncodedSignedInteger(Value);
+      emitEncodedSignedInteger(Value, Comment);
   } else if (isWriting()) {
     if (Value >= 0) {
       if (auto EC = writeEncodedUnsignedInteger(static_cast<uint64_t>(Value)))
@@ -161,9 +166,10 @@ Error CodeViewRecordIO::mapEncodedInteger(int64_t &Value) {
   return Error::success();
 }
 
-Error CodeViewRecordIO::mapEncodedInteger(uint64_t &Value) {
+Error CodeViewRecordIO::mapEncodedInteger(uint64_t &Value,
+                                          const Twine &Comment) {
   if (isStreaming())
-    emitEncodedUnsignedInteger(Value);
+    emitEncodedUnsignedInteger(Value, Comment);
   else if (isWriting()) {
     if (auto EC = writeEncodedUnsignedInteger(Value))
       return EC;
@@ -176,12 +182,12 @@ Error CodeViewRecordIO::mapEncodedInteger(uint64_t &Value) {
   return Error::success();
 }
 
-Error CodeViewRecordIO::mapEncodedInteger(APSInt &Value) {
+Error CodeViewRecordIO::mapEncodedInteger(APSInt &Value, const Twine &Comment) {
   if (isStreaming()) {
     if (Value.isSigned())
-      emitEncodedSignedInteger(Value.getSExtValue());
+      emitEncodedSignedInteger(Value.getSExtValue(), Comment);
     else
-      emitEncodedUnsignedInteger(Value.getZExtValue());
+      emitEncodedUnsignedInteger(Value.getZExtValue(), Comment);
   } else if (isWriting()) {
     if (Value.isSigned())
       return writeEncodedSignedInteger(Value.getSExtValue());
@@ -191,9 +197,10 @@ Error CodeViewRecordIO::mapEncodedInteger(APSInt &Value) {
   return Error::success();
 }
 
-Error CodeViewRecordIO::mapStringZ(StringRef &Value) {
+Error CodeViewRecordIO::mapStringZ(StringRef &Value, const Twine &Comment) {
   if (isStreaming()) {
     auto NullTerminatedString = StringRef(Value.data(), Value.size() + 1);
+    emitComment(Comment);
     Streamer->EmitBytes(NullTerminatedString);
     incrStreamedLen(NullTerminatedString.size());
   } else if (isWriting()) {
@@ -208,12 +215,13 @@ Error CodeViewRecordIO::mapStringZ(StringRef &Value) {
   return Error::success();
 }
 
-Error CodeViewRecordIO::mapGuid(GUID &Guid) {
+Error CodeViewRecordIO::mapGuid(GUID &Guid, const Twine &Comment) {
   constexpr uint32_t GuidSize = 16;
 
   if (isStreaming()) {
     StringRef GuidSR =
         StringRef((reinterpret_cast<const char *>(&Guid)), GuidSize);
+    emitComment(Comment);
     Streamer->EmitBytes(GuidSR);
     incrStreamedLen(GuidSize);
     return Error::success();
@@ -234,9 +242,11 @@ Error CodeViewRecordIO::mapGuid(GUID &Guid) {
   return Error::success();
 }
 
-Error CodeViewRecordIO::mapStringZVectorZ(std::vector<StringRef> &Value) {
+Error CodeViewRecordIO::mapStringZVectorZ(std::vector<StringRef> &Value,
+                                          const Twine &Comment) {
 
   if (!isReading()) {
+    emitComment(Comment);
     for (auto V : Value) {
       if (auto EC = mapStringZ(V))
         return EC;
@@ -257,41 +267,51 @@ Error CodeViewRecordIO::mapStringZVectorZ(std::vector<StringRef> &Value) {
   return Error::success();
 }
 
-void CodeViewRecordIO::emitEncodedSignedInteger(const int64_t &Value) {
+void CodeViewRecordIO::emitEncodedSignedInteger(const int64_t &Value,
+                                                const Twine &Comment) {
   assert(Value < 0 && "Encoded integer is not signed!");
   if (Value >= std::numeric_limits<int8_t>::min()) {
     Streamer->EmitIntValue(LF_CHAR, 2);
+    emitComment(Comment);
     Streamer->EmitIntValue(Value, 1);
     incrStreamedLen(3);
   } else if (Value >= std::numeric_limits<int16_t>::min()) {
     Streamer->EmitIntValue(LF_SHORT, 2);
+    emitComment(Comment);
     Streamer->EmitIntValue(Value, 2);
     incrStreamedLen(4);
   } else if (Value >= std::numeric_limits<int32_t>::min()) {
     Streamer->EmitIntValue(LF_LONG, 2);
+    emitComment(Comment);
     Streamer->EmitIntValue(Value, 4);
     incrStreamedLen(6);
   } else {
     Streamer->EmitIntValue(LF_QUADWORD, 2);
+    emitComment(Comment);
     Streamer->EmitIntValue(Value, 4);
     incrStreamedLen(6);
   }
 }
 
-void CodeViewRecordIO::emitEncodedUnsignedInteger(const uint64_t &Value) {
+void CodeViewRecordIO::emitEncodedUnsignedInteger(const uint64_t &Value,
+                                                  const Twine &Comment) {
   if (Value < LF_NUMERIC) {
+    emitComment(Comment);
     Streamer->EmitIntValue(Value, 2);
     incrStreamedLen(2);
   } else if (Value <= std::numeric_limits<uint16_t>::max()) {
     Streamer->EmitIntValue(LF_USHORT, 2);
+    emitComment(Comment);
     Streamer->EmitIntValue(Value, 2);
     incrStreamedLen(4);
   } else if (Value <= std::numeric_limits<uint32_t>::max()) {
     Streamer->EmitIntValue(LF_ULONG, 2);
+    emitComment(Comment);
     Streamer->EmitIntValue(Value, 4);
     incrStreamedLen(6);
   } else {
     Streamer->EmitIntValue(LF_UQUADWORD, 2);
+    emitComment(Comment);
     Streamer->EmitIntValue(Value, 8);
     incrStreamedLen(6);
   }
diff --git a/llvm/lib/DebugInfo/CodeView/TypeRecordMapping.cpp b/llvm/lib/DebugInfo/CodeView/TypeRecordMapping.cpp
index 104e310d41b..8e8eba4d53e 100644
--- a/llvm/lib/DebugInfo/CodeView/TypeRecordMapping.cpp
+++ b/llvm/lib/DebugInfo/CodeView/TypeRecordMapping.cpp
@@ -21,19 +21,19 @@ struct MapOneMethodRecord {
       : IsFromOverloadList(IsFromOverloadList) {}
 
   Error operator()(CodeViewRecordIO &IO, OneMethodRecord &Method) const {
-    error(IO.mapInteger(Method.Attrs.Attrs));
+    error(IO.mapInteger(Method.Attrs.Attrs, "AccessSpecifier"));
     if (IsFromOverloadList) {
       uint16_t Padding = 0;
-      error(IO.mapInteger(Padding));
+      error(IO.mapInteger(Padding, "Padding"));
     }
-    error(IO.mapInteger(Method.Type));
+    error(IO.mapInteger(Method.Type, "Type"));
     if (Method.isIntroducingVirtual()) {
-      error(IO.mapInteger(Method.VFTableOffset));
+      error(IO.mapInteger(Method.VFTableOffset, "VFTableOffset"));
     } else if (IO.isReading())
       Method.VFTableOffset = -1;
 
     if (!IsFromOverloadList)
-      error(IO.mapStringZ(Method.Name));
+      error(IO.mapStringZ(Method.Name, "Name"));
 
     return Error::success();
   }
@@ -75,9 +75,9 @@ static Error mapNameAndUniqueName(CodeViewRecordIO &IO, StringRef &Name,
     // Reading & Streaming mode come after writing mode is executed for each
     // record. Truncating large names are done during writing, so its not
     // necessary to do it while reading or streaming.
-    error(IO.mapStringZ(Name));
+    error(IO.mapStringZ(Name, "Name"));
     if (HasUniqueName)
-      error(IO.mapStringZ(UniqueName));
+      error(IO.mapStringZ(UniqueName, "LinkageName"));
   }
 
   return Error::success();
@@ -144,32 +144,32 @@ Error TypeRecordMapping::visitMemberEnd(CVMemberRecord &Record) {
 }
 
 Error TypeRecordMapping::visitKnownRecord(CVType &CVR, ModifierRecord &Record) {
-  error(IO.mapInteger(Record.ModifiedType));
-  error(IO.mapEnum(Record.Modifiers));
+  error(IO.mapInteger(Record.ModifiedType, "ModifiedType"));
+  error(IO.mapEnum(Record.Modifiers, "Modifiers"));
   return Error::success();
 }
 
 Error TypeRecordMapping::visitKnownRecord(CVType &CVR,
                                           ProcedureRecord &Record) {
-  error(IO.mapInteger(Record.ReturnType));
-  error(IO.mapEnum(Record.CallConv));
-  error(IO.mapEnum(Record.Options));
-  error(IO.mapInteger(Record.ParameterCount));
-  error(IO.mapInteger(Record.ArgumentList));
+  error(IO.mapInteger(Record.ReturnType, "ReturnType"));
+  error(IO.mapEnum(Record.CallConv, "CallingConvention"));
+  error(IO.mapEnum(Record.Options, "FunctionOptions"));
+  error(IO.mapInteger(Record.ParameterCount, "NumParameters"));
+  error(IO.mapInteger(Record.ArgumentList, "ArgListType"));
 
   return Error::success();
 }
 
 Error TypeRecordMapping::visitKnownRecord(CVType &CVR,
                                           MemberFunctionRecord &Record) {
-  error(IO.mapInteger(Record.ReturnType));
-  error(IO.mapInteger(Record.ClassType));
-  error(IO.mapInteger(Record.ThisType));
-  error(IO.mapEnum(Record.CallConv));
-  error(IO.mapEnum(Record.Options));
-  error(IO.mapInteger(Record.ParameterCount));
-  error(IO.mapInteger(Record.ArgumentList));
-  error(IO.mapInteger(Record.ThisPointerAdjustment));
+  error(IO.mapInteger(Record.ReturnType, "ReturnType"));
+  error(IO.mapInteger(Record.ClassType, "ClassType"));
+  error(IO.mapInteger(Record.ThisType, "ThisType"));
+  error(IO.mapEnum(Record.CallConv, "CallingConvention"));
+  error(IO.mapEnum(Record.Options, "FunctionOptions"));
+  error(IO.mapInteger(Record.ParameterCount, "NumParameters"));
+  error(IO.mapInteger(Record.ArgumentList, "ArgListType"));
+  error(IO.mapInteger(Record.ThisPointerAdjustment, "ThisAdjustment"));
 
   return Error::success();
 }
@@ -177,7 +177,10 @@ Error TypeRecordMapping::visitKnownRecord(CVType &CVR,
 Error TypeRecordMapping::visitKnownRecord(CVType &CVR, ArgListRecord &Record) {
   error(IO.mapVectorN<uint32_t>(
       Record.ArgIndices,
-      [](CodeViewRecordIO &IO, TypeIndex &N) { return IO.mapInteger(N); }));
+      [](CodeViewRecordIO &IO, TypeIndex &N) {
+        return IO.mapInteger(N, "Argument");
+      },
+      "NumArgs"));
   return Error::success();
 }
 
@@ -185,32 +188,35 @@ Error TypeRecordMapping::visitKnownRecord(CVType &CVR,
                                           StringListRecord &Record) {
   error(IO.mapVectorN<uint32_t>(
       Record.StringIndices,
-      [](CodeViewRecordIO &IO, TypeIndex &N) { return IO.mapInteger(N); }));
+      [](CodeViewRecordIO &IO, TypeIndex &N) {
+        return IO.mapInteger(N, "Strings");
+      },
+      "NumStrings"));
 
   return Error::success();
 }
 
 Error TypeRecordMapping::visitKnownRecord(CVType &CVR, PointerRecord &Record) {
-  error(IO.mapInteger(Record.ReferentType));
-  error(IO.mapInteger(Record.Attrs));
+  error(IO.mapInteger(Record.ReferentType, "PointeeType"));
+  error(IO.mapInteger(Record.Attrs, "Attributes"));
 
   if (Record.isPointerToMember()) {
     if (IO.isReading())
       Record.MemberInfo.emplace();
 
     MemberPointerInfo &M = *Record.MemberInfo;
-    error(IO.mapInteger(M.ContainingType));
-    error(IO.mapEnum(M.Representation));
+    error(IO.mapInteger(M.ContainingType, "ClassType"));
+    error(IO.mapEnum(M.Representation, "Representation"));
   }
 
   return Error::success();
 }
 
 Error TypeRecordMapping::visitKnownRecord(CVType &CVR, ArrayRecord &Record) {
-  error(IO.mapInteger(Record.ElementType));
-  error(IO.mapInteger(Record.IndexType));
-  error(IO.mapEncodedInteger(Record.Size));
-  error(IO.mapStringZ(Record.Name));
+  error(IO.mapInteger(Record.ElementType, "ElementType"));
+  error(IO.mapInteger(Record.IndexType, "IndexType"));
+  error(IO.mapEncodedInteger(Record.Size, "SizeOf"));
+  error(IO.mapStringZ(Record.Name, "Name"));
 
   return Error::success();
 }
@@ -220,12 +226,12 @@ Error TypeRecordMapping::visitKnownRecord(CVType &CVR, ClassRecord &Record) {
          (CVR.kind() == TypeLeafKind::LF_CLASS) ||
          (CVR.kind() == TypeLeafKind::LF_INTERFACE));
 
-  error(IO.mapInteger(Record.MemberCount));
-  error(IO.mapEnum(Record.Options));
-  error(IO.mapInteger(Record.FieldList));
-  error(IO.mapInteger(Record.DerivationList));
-  error(IO.mapInteger(Record.VTableShape));
-  error(IO.mapEncodedInteger(Record.Size));
+  error(IO.mapInteger(Record.MemberCount, "MemberCount"));
+  error(IO.mapEnum(Record.Options, "Properties"));
+  error(IO.mapInteger(Record.FieldList, "FieldList"));
+  error(IO.mapInteger(Record.DerivationList, "DerivedFrom"));
+  error(IO.mapInteger(Record.VTableShape, "VShape"));
+  error(IO.mapEncodedInteger(Record.Size, "SizeOf"));
   error(mapNameAndUniqueName(IO, Record.Name, Record.UniqueName,
                              Record.hasUniqueName()));
 
@@ -233,10 +239,10 @@ Error TypeRecordMapping::visitKnownRecord(CVType &CVR, ClassRecord &Record) {
 }
 
 Error TypeRecordMapping::visitKnownRecord(CVType &CVR, UnionRecord &Record) {
-  error(IO.mapInteger(Record.MemberCount));
-  error(IO.mapEnum(Record.Options));
-  error(IO.mapInteger(Record.FieldList));
-  error(IO.mapEncodedInteger(Record.Size));
+  error(IO.mapInteger(Record.MemberCount, "MemberCount"));
+  error(IO.mapEnum(Record.Options, "Properties"));
+  error(IO.mapInteger(Record.FieldList, "FieldList"));
+  error(IO.mapEncodedInteger(Record.Size, "SizeOf"));
   error(mapNameAndUniqueName(IO, Record.Name, Record.UniqueName,
                              Record.hasUniqueName()));
 
@@ -244,10 +250,10 @@ Error TypeRecordMapping::visitKnownRecord(CVType &CVR, UnionRecord &Record) {
 }
 
 Error TypeRecordMapping::visitKnownRecord(CVType &CVR, EnumRecord &Record) {
-  error(IO.mapInteger(Record.MemberCount));
-  error(IO.mapEnum(Record.Options));
-  error(IO.mapInteger(Record.UnderlyingType));
-  error(IO.mapInteger(Record.FieldList));
+  error(IO.mapInteger(Record.MemberCount, "NumEnumerators"));
+  error(IO.mapEnum(Record.Options, "Properties"));
+  error(IO.mapInteger(Record.UnderlyingType, "UnderlyingType"));
+  error(IO.mapInteger(Record.FieldList, "FieldListType"));
   error(mapNameAndUniqueName(IO, Record.Name, Record.UniqueName,
                              Record.hasUniqueName()));
 
@@ -255,9 +261,9 @@ Error TypeRecordMapping::visitKnownRecord(CVType &CVR, EnumRecord &Record) {
 }
 
 Error TypeRecordMapping::visitKnownRecord(CVType &CVR, BitFieldRecord &Record) {
-  error(IO.mapInteger(Record.Type));
-  error(IO.mapInteger(Record.BitSize));
-  error(IO.mapInteger(Record.BitOffset));
+  error(IO.mapInteger(Record.Type, "Type"));
+  error(IO.mapInteger(Record.BitSize, "BitSize"));
+  error(IO.mapInteger(Record.BitOffset, "BitOffset"));
 
   return Error::success();
 }
@@ -268,7 +274,7 @@ Error TypeRecordMapping::visitKnownRecord(CVType &CVR,
   if (!IO.isReading()) {
     ArrayRef<VFTableSlotKind> Slots = Record.getSlots();
     Size = Slots.size();
-    error(IO.mapInteger(Size));
+    error(IO.mapInteger(Size, "VFEntryCount"));
 
     for (size_t SlotIndex = 0; SlotIndex < Slots.size(); SlotIndex += 2) {
       uint8_t Byte = static_cast<uint8_t>(Slots[SlotIndex]) << 4;
@@ -292,61 +298,64 @@ Error TypeRecordMapping::visitKnownRecord(CVType &CVR,
 }
 
 Error TypeRecordMapping::visitKnownRecord(CVType &CVR, VFTableRecord &Record) {
-  error(IO.mapInteger(Record.CompleteClass));
-  error(IO.mapInteger(Record.OverriddenVFTable));
-  error(IO.mapInteger(Record.VFPtrOffset));
+  error(IO.mapInteger(Record.CompleteClass, "CompleteClass"));
+  error(IO.mapInteger(Record.OverriddenVFTable, "OverriddenVFTable"));
+  error(IO.mapInteger(Record.VFPtrOffset, "VFPtrOffset"));
   uint32_t NamesLen = 0;
   if (!IO.isReading()) {
     for (auto Name : Record.MethodNames)
       NamesLen += Name.size() + 1;
   }
-  error(IO.mapInteger(NamesLen));
+  error(IO.mapInteger(NamesLen, ""));
   error(IO.mapVectorTail(
       Record.MethodNames,
-      [](CodeViewRecordIO &IO, StringRef &S) { return IO.mapStringZ(S); }));
+      [](CodeViewRecordIO &IO, StringRef &S) {
+        return IO.mapStringZ(S, "MethodName");
+      },
+      "VFTableName"));
 
   return Error::success();
 }
 
 Error TypeRecordMapping::visitKnownRecord(CVType &CVR, StringIdRecord &Record) {
-  error(IO.mapInteger(Record.Id));
-  error(IO.mapStringZ(Record.String));
+  error(IO.mapInteger(Record.Id, "Id"));
+  error(IO.mapStringZ(Record.String, "StringData"));
 
   return Error::success();
 }
 
 Error TypeRecordMapping::visitKnownRecord(CVType &CVR,
                                           UdtSourceLineRecord &Record) {
-  error(IO.mapInteger(Record.UDT));
-  error(IO.mapInteger(Record.SourceFile));
-  error(IO.mapInteger(Record.LineNumber));
+  error(IO.mapInteger(Record.UDT, "UDT"));
+  error(IO.mapInteger(Record.SourceFile, "SourceFile"));
+  error(IO.mapInteger(Record.LineNumber, "LineNumber"));
 
   return Error::success();
 }
 
 Error TypeRecordMapping::visitKnownRecord(CVType &CVR,
                                           UdtModSourceLineRecord &Record) {
-  error(IO.mapInteger(Record.UDT));
-  error(IO.mapInteger(Record.SourceFile));
-  error(IO.mapInteger(Record.LineNumber));
-  error(IO.mapInteger(Record.Module));
+  error(IO.mapInteger(Record.UDT, "UDT"));
+  error(IO.mapInteger(Record.SourceFile, "SourceFile"));
+  error(IO.mapInteger(Record.LineNumber, "LineNumber"));
+  error(IO.mapInteger(Record.Module, "Module"));
 
   return Error::success();
 }
 
 Error TypeRecordMapping::visitKnownRecord(CVType &CVR, FuncIdRecord &Record) {
-  error(IO.mapInteger(Record.ParentScope));
-  error(IO.mapInteger(Record.FunctionType));
-  error(IO.mapStringZ(Record.Name));
+  error(IO.mapInteger(Record.ParentScope, "ParentScope"));
+  error(IO.mapInteger(Record.FunctionType, "FunctionType"));
+  error(IO.mapStringZ(Record.Name, "Name"));
 
   return Error::success();
 }
 
 Error TypeRecordMapping::visitKnownRecord(CVType &CVR,
                                           MemberFuncIdRecord &Record) {
-  error(IO.mapInteger(Record.ClassType));
-  error(IO.mapInteger(Record.FunctionType));
-  error(IO.mapStringZ(Record.Name));
+  error(IO.mapInteger(Record.ClassType, "ClassType"));
+  error(IO.mapInteger(Record.FunctionType, "FunctionType"));
+  error(IO.mapStringZ(Record.Name, "Name"));
 
   return Error::success();
 }
@@ -355,7 +364,10 @@ Error TypeRecordMapping::visitKnownRecord(CVType &CVR,
                                           BuildInfoRecord &Record) {
   error(IO.mapVectorN<uint16_t>(
       Record.ArgIndices,
-      [](CodeViewRecordIO &IO, TypeIndex &N) { return IO.mapInteger(N); }));
+      [](CodeViewRecordIO &IO, TypeIndex &N) {
+        return IO.mapInteger(N, "Argument");
+      },
+      "NumArgs"));
 
   return Error::success();
 }
@@ -364,7 +376,7 @@ Error TypeRecordMapping::visitKnownRecord(CVType &CVR,
                                           MethodOverloadListRecord &Record) {
   // TODO: Split the list into multiple records if it's longer than 64KB, using
   // a subrecord of TypeRecordKind::Index to chain the records together.
-  error(IO.mapVectorTail(Record.Methods, MapOneMethodRecord(true)));
+  error(IO.mapVectorTail(Record.Methods, MapOneMethodRecord(true), "Method"));
 
   return Error::success();
 }
@@ -378,22 +390,22 @@ Error TypeRecordMapping::visitKnownRecord(CVType &CVR,
 
 Error TypeRecordMapping::visitKnownRecord(CVType &CVR,
                                           TypeServer2Record &Record) {
-  error(IO.mapGuid(Record.Guid));
-  error(IO.mapInteger(Record.Age));
-  error(IO.mapStringZ(Record.Name));
+  error(IO.mapGuid(Record.Guid, "Guid"));
+  error(IO.mapInteger(Record.Age, "Age"));
+  error(IO.mapStringZ(Record.Name, "Name"));
   return Error::success();
 }
 
 Error TypeRecordMapping::visitKnownRecord(CVType &CVR, LabelRecord &Record) {
-  error(IO.mapEnum(Record.Mode));
+  error(IO.mapEnum(Record.Mode, "Mode"));
   return Error::success();
 }
 
 Error TypeRecordMapping::visitKnownMember(CVMemberRecord &CVR,
                                           BaseClassRecord &Record) {
-  error(IO.mapInteger(Record.Attrs.Attrs));
-  error(IO.mapInteger(Record.Type));
-  error(IO.mapEncodedInteger(Record.Offset));
+  error(IO.mapInteger(Record.Attrs.Attrs, "AccessSpecifier"));
+  error(IO.mapInteger(Record.Type, "BaseType"));
+  error(IO.mapEncodedInteger(Record.Offset, "BaseOffset"));
 
   return Error::success();
 }
@@ -403,27 +415,27 @@ Error TypeRecordMapping::visitKnownMember(CVMemberRecord &CVR,
   error(IO.mapInteger(Record.Attrs.Attrs));
 
   // FIXME: Handle full APInt such as __int128.
-  error(IO.mapEncodedInteger(Record.Value));
-  error(IO.mapStringZ(Record.Name));
+  error(IO.mapEncodedInteger(Record.Value, "EnumValue"));
+  error(IO.mapStringZ(Record.Name, "Name"));
 
   return Error::success();
 }
 
 Error TypeRecordMapping::visitKnownMember(CVMemberRecord &CVR,
                                           DataMemberRecord &Record) {
-  error(IO.mapInteger(Record.Attrs.Attrs));
-  error(IO.mapInteger(Record.Type));
-  error(IO.mapEncodedInteger(Record.FieldOffset));
-  error(IO.mapStringZ(Record.Name));
+  error(IO.mapInteger(Record.Attrs.Attrs, "AccessSpecifier"));
+  error(IO.mapInteger(Record.Type, "Type"));
+  error(IO.mapEncodedInteger(Record.FieldOffset, "FieldOffset"));
+  error(IO.mapStringZ(Record.Name, "Name"));
 
   return Error::success();
 }
 
 Error TypeRecordMapping::visitKnownMember(CVMemberRecord &CVR,
                                           OverloadedMethodRecord &Record) {
-  error(IO.mapInteger(Record.NumOverloads));
-  error(IO.mapInteger(Record.MethodList));
-  error(IO.mapStringZ(Record.Name));
+  error(IO.mapInteger(Record.NumOverloads, "MethodCount"));
+  error(IO.mapInteger(Record.MethodList, "MethodListIndex"));
+  error(IO.mapStringZ(Record.Name, "Name"));
 
   return Error::success();
 }
@@ -438,9 +450,9 @@ Error TypeRecordMapping::visitKnownMember(CVMemberRecord &CVR,
 Error TypeRecordMapping::visitKnownMember(CVMemberRecord &CVR,
                                           NestedTypeRecord &Record) {
   uint16_t Padding = 0;
-  error(IO.mapInteger(Padding));
-  error(IO.mapInteger(Record.Type));
-  error(IO.mapStringZ(Record.Name));
+  error(IO.mapInteger(Padding, "Padding"));
+  error(IO.mapInteger(Record.Type, "Type"));
+  error(IO.mapStringZ(Record.Name, "Name"));
 
   return Error::success();
 }
@@ -448,9 +460,9 @@ Error TypeRecordMapping::visitKnownMember(CVMemberRecord &CVR,
 Error TypeRecordMapping::visitKnownMember(CVMemberRecord &CVR,
                                           StaticDataMemberRecord &Record) {
 
-  error(IO.mapInteger(Record.Attrs.Attrs));
-  error(IO.mapInteger(Record.Type));
-  error(IO.mapStringZ(Record.Name));
+  error(IO.mapInteger(Record.Attrs.Attrs, "AccessSpecifier"));
+  error(IO.mapInteger(Record.Type, "Type"));
+  error(IO.mapStringZ(Record.Name, "Name"));
 
   return Error::success();
 }
@@ -458,11 +470,11 @@ Error TypeRecordMapping::visitKnownMember(CVMemberRecord &CVR,
 Error TypeRecordMapping::visitKnownMember(CVMemberRecord &CVR,
                                           VirtualBaseClassRecord &Record) {
 
-  error(IO.mapInteger(Record.Attrs.Attrs));
-  error(IO.mapInteger(Record.BaseType));
-  error(IO.mapInteger(Record.VBPtrType));
-  error(IO.mapEncodedInteger(Record.VBPtrOffset));
-  error(IO.mapEncodedInteger(Record.VTableIndex));
+  error(IO.mapInteger(Record.Attrs.Attrs, "AccessSpecifier"));
+  error(IO.mapInteger(Record.BaseType, "BaseType"));
+  error(IO.mapInteger(Record.VBPtrType, "VBPtrType"));
+  error(IO.mapEncodedInteger(Record.VBPtrOffset, "VBPtrOffset"));
+  error(IO.mapEncodedInteger(Record.VTableIndex, "VBTableIndex"));
 
   return Error::success();
 }
@@ -470,8 +482,8 @@ Error TypeRecordMapping::visitKnownMember(CVMemberRecord &CVR,
 Error TypeRecordMapping::visitKnownMember(CVMemberRecord &CVR,
                                           VFPtrRecord &Record) {
   uint16_t Padding = 0;
-  error(IO.mapInteger(Padding));
-  error(IO.mapInteger(Record.Type));
+  error(IO.mapInteger(Padding, "Padding"));
+  error(IO.mapInteger(Record.Type, "Type"));
 
   return Error::success();
 }
@@ -479,23 +491,23 @@ Error TypeRecordMapping::visitKnownMember(CVMemberRecord &CVR,
 Error TypeRecordMapping::visitKnownMember(CVMemberRecord &CVR,
                                           ListContinuationRecord &Record) {
   uint16_t Padding = 0;
-  error(IO.mapInteger(Padding));
-  error(IO.mapInteger(Record.ContinuationIndex));
+  error(IO.mapInteger(Padding, "Padding"));
+  error(IO.mapInteger(Record.ContinuationIndex, "ContinuationIndex"));
 
   return Error::success();
 }
 
 Error TypeRecordMapping::visitKnownRecord(CVType &CVR,
                                           PrecompRecord &Precomp) {
-  error(IO.mapInteger(Precomp.StartTypeIndex));
-  error(IO.mapInteger(Precomp.TypesCount));
-  error(IO.mapInteger(Precomp.Signature));
-  error(IO.mapStringZ(Precomp.PrecompFilePath));
+  error(IO.mapInteger(Precomp.StartTypeIndex, "StartIndex"));
+  error(IO.mapInteger(Precomp.TypesCount, "Count"));
+  error(IO.mapInteger(Precomp.Signature, "Signature"));
+  error(IO.mapStringZ(Precomp.PrecompFilePath, "PrecompFile"));
   return Error::success();
 }
 
 Error TypeRecordMapping::visitKnownRecord(CVType &CVR,
                                           EndPrecompRecord &EndPrecomp) {
-  error(IO.mapInteger(EndPrecomp.Signature));
+  error(IO.mapInteger(EndPrecomp.Signature, "Signature"));
   return Error::success();
 }