[codeview] Add support for label type records

MASM can produce these type records.

llvm-svn: 299388

include/llvm/DebugInfo/CodeView/CodeView.h

@@ -275,6 +275,12 @@ enum class MethodOptions : uint16_t {
 };
 CV_DEFINE_ENUM_CLASS_FLAGS_OPERATORS(MethodOptions)
 
+/// Equivalent to CV_LABEL_TYPE_e.
+enum class LabelType : uint16_t {
+  Near = 0x0,
+  Far  = 0x4,
+};
+
 /// Equivalent to CV_modifier_t.
 /// TODO: Add flag for _Atomic modifier
 enum class ModifierOptions : uint16_t {

include/llvm/DebugInfo/CodeView/TypeRecord.h

@@ -199,6 +199,16 @@ public:
   int32_t ThisPointerAdjustment;
 };
 
+// LF_LABEL
+class LabelRecord : public TypeRecord {
+public:
+  explicit LabelRecord(TypeRecordKind Kind) : TypeRecord(Kind) {}
+
+  LabelRecord(LabelType Mode) : TypeRecord(TypeRecordKind::Label), Mode(Mode) {}
+
+  LabelType Mode;
+};
+
 // LF_MFUNC_ID
 class MemberFuncIdRecord : public TypeRecord {
 public:

include/llvm/DebugInfo/CodeView/TypeRecords.def

@@ -41,6 +41,7 @@ TYPE_RECORD(LF_POINTER, 0x1002, Pointer)
 TYPE_RECORD(LF_MODIFIER, 0x1001, Modifier)
 TYPE_RECORD(LF_PROCEDURE, 0x1008, Procedure)
 TYPE_RECORD(LF_MFUNCTION, 0x1009, MemberFunction)
+TYPE_RECORD(LF_LABEL, 0x000e, Label)
 TYPE_RECORD(LF_ARGLIST, 0x1201, ArgList)
 
 TYPE_RECORD(LF_FIELDLIST, 0x1203, FieldList)
@@ -101,7 +102,6 @@ CV_TYPE(LF_MFUNCTION_16t, 0x0009)
 CV_TYPE(LF_COBOL0_16t, 0x000b)
 CV_TYPE(LF_COBOL1, 0x000c)
 CV_TYPE(LF_BARRAY_16t, 0x000d)
-CV_TYPE(LF_LABEL, 0x000e)
 CV_TYPE(LF_NULLLEAF, 0x000f) // LF_NULL
 CV_TYPE(LF_NOTTRAN, 0x0010)
 CV_TYPE(LF_DIMARRAY_16t, 0x0011)

lib/DebugInfo/CodeView/TypeDatabaseVisitor.cpp

@@ -299,6 +299,10 @@ Error TypeDatabaseVisitor::visitKnownRecord(CVType &CVR, BuildInfoRecord &BI) {
   return Error::success();
 }
 
+Error TypeDatabaseVisitor::visitKnownRecord(CVType &CVR, LabelRecord &R) {
+  return Error::success();
+}
+
 Error TypeDatabaseVisitor::visitKnownMember(CVMemberRecord &CVR,
                                             VFPtrRecord &VFP) {
   return Error::success();

lib/DebugInfo/CodeView/TypeDumpVisitor.cpp

@@ -146,6 +146,10 @@ static const EnumEntry<uint8_t> FunctionOptionEnum[] = {
     ENUM_ENTRY(FunctionOptions, ConstructorWithVirtualBases),
 };
 
+static const EnumEntry<uint16_t> LabelTypeEnum[] = {
+    ENUM_ENTRY(LabelType, Near), ENUM_ENTRY(LabelType, Far),
+};
+
 #undef ENUM_ENTRY
 
 static StringRef getLeafTypeName(TypeLeafKind LT) {
@@ -547,3 +551,8 @@ Error TypeDumpVisitor::visitKnownMember(CVMemberRecord &CVR,
   printTypeIndex("ContinuationIndex", Cont.getContinuationIndex());
   return Error::success();
 }
+
+Error TypeDumpVisitor::visitKnownRecord(CVType &CVR, LabelRecord &LR) {
+  W->printEnum("Mode", uint16_t(LR.Mode), makeArrayRef(LabelTypeEnum));
+  return Error::success();
+}

lib/DebugInfo/CodeView/TypeRecordMapping.cpp

@@ -380,6 +380,11 @@ Error TypeRecordMapping::visitKnownRecord(CVType &CVR,
   return Error::success();
 }
 
+Error TypeRecordMapping::visitKnownRecord(CVType &CVR, LabelRecord &Record) {
+  error(IO.mapEnum(Record.Mode));
+  return Error::success();
+}
+
 Error TypeRecordMapping::visitKnownMember(CVMemberRecord &CVR,
                                           BaseClassRecord &Record) {
   error(IO.mapInteger(Record.Attrs.Attrs));

lib/DebugInfo/CodeView/TypeStreamMerger.cpp

@@ -301,6 +301,10 @@ Error TypeStreamMerger::visitKnownRecord(CVType &, TypeServer2Record &R) {
   return writeRecord(R, true);
 }
 
+Error TypeStreamMerger::visitKnownRecord(CVType &, LabelRecord &R) {
+  return writeRecord(R, true);
+}
+
 Error TypeStreamMerger::visitKnownRecord(CVType &, VFTableRecord &R) {
   bool Success = true;
   Success &= remapIndex(R.CompleteClass);

test/tools/llvm-readobj/codeview-label.test

@@ -0,0 +1,16 @@
+; RUN: llvm-readobj -codeview %S/Inputs/codeview-label.obj | FileCheck %s
+
+; CHECK-LABEL:  Label (0x1000) {
+; CHECK-NEXT:     TypeLeafKind: LF_LABEL (0xE)
+; CHECK-NEXT:     Mode: Near (0x0)
+; CHECK-NEXT:   }
+
+; To reproduce codeview-label.obj:
+; $ cat codeview-label.asm
+;         .model flat, C
+;         .code
+;         public  foo
+; foo:
+;         ret
+; end
+; $ ml -c -Zi codeview-label.asm

tools/llvm-pdbdump/YamlTypeDumper.cpp

@@ -194,6 +194,13 @@ template <> struct ScalarEnumerationTraits<WindowsRTClassKind> {
   }
 };
 
+template <> struct ScalarEnumerationTraits<LabelType> {
+  static void enumeration(IO &IO, LabelType &Value) {
+    IO.enumCase(Value, "Near", LabelType::Near);
+    IO.enumCase(Value, "Far", LabelType::Far);
+  }
+};
+
 template <> struct ScalarBitSetTraits<PointerOptions> {
   static void bitset(IO &IO, PointerOptions &Options) {
     IO.bitSetCase(Options, "None", PointerOptions::None);
@@ -431,6 +438,10 @@ void MappingTraits<BuildInfoRecord>::mapping(IO &IO, BuildInfoRecord &Args) {
   IO.mapRequired("ArgIndices", Args.ArgIndices);
 }
 
+void MappingTraits<LabelRecord>::mapping(IO &IO, LabelRecord &R) {
+  IO.mapRequired("Mode", R.Mode);
+}
+
 void MappingTraits<NestedTypeRecord>::mapping(IO &IO,
                                               NestedTypeRecord &Nested) {
   IO.mapRequired("Type", Nested.Type);