diff --git a/lib/DebugInfo/CMakeLists.txt b/lib/DebugInfo/CMakeLists.txt
index 5ab46444531..645d92fef22 100644
--- a/lib/DebugInfo/CMakeLists.txt
+++ b/lib/DebugInfo/CMakeLists.txt
@@ -1,5 +1,4 @@
 
 add_subdirectory(DWARF)
-if (MSVC)
-  add_subdirectory(PDB)
-endif()
\ No newline at end of file
+add_subdirectory(PDB)
+
diff --git a/unittests/DebugInfo/CMakeLists.txt b/unittests/DebugInfo/CMakeLists.txt
index ffc908608ab..dae472bafdd 100644
--- a/unittests/DebugInfo/CMakeLists.txt
+++ b/unittests/DebugInfo/CMakeLists.txt
@@ -1,11 +1,3 @@
-set(LLVM_LINK_COMPONENTS
-  DebugInfoDWARF
-  )
 
-set(DebugInfoSources
-  DWARFFormValueTest.cpp
-  )
-
-add_llvm_unittest(DebugInfoTests
-  ${DebugInfoSources}
-  )
+add_subdirectory(DWARF)
+add_subdirectory(PDB)
diff --git a/unittests/DebugInfo/DWARF/CMakeLists.txt b/unittests/DebugInfo/DWARF/CMakeLists.txt
new file mode 100644
index 00000000000..4bec17cbb52
--- /dev/null
+++ b/unittests/DebugInfo/DWARF/CMakeLists.txt
@@ -0,0 +1,11 @@
+set(LLVM_LINK_COMPONENTS
+  DebugInfoDWARF
+  )
+
+set(DebugInfoSources
+  DWARFFormValueTest.cpp
+  )
+
+add_llvm_unittest(DebugInfoDWARFTests
+  ${DebugInfoSources}
+  )
diff --git a/unittests/DebugInfo/DWARFFormValueTest.cpp b/unittests/DebugInfo/DWARF/DWARFFormValueTest.cpp
similarity index 100%
rename from unittests/DebugInfo/DWARFFormValueTest.cpp
rename to unittests/DebugInfo/DWARF/DWARFFormValueTest.cpp
diff --git a/unittests/DebugInfo/DWARF/Makefile b/unittests/DebugInfo/DWARF/Makefile
new file mode 100644
index 00000000000..b0f40e1ca9d
--- /dev/null
+++ b/unittests/DebugInfo/DWARF/Makefile
@@ -0,0 +1,16 @@
+##===- unittests/DebugInfo/Makefile ------------------------*- Makefile -*-===##
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+##===----------------------------------------------------------------------===##
+
+LEVEL = ../../..
+TESTNAME = DebugInfoDWARF
+LINK_COMPONENTS := DebugInfoDWARF object support
+
+include $(LEVEL)/Makefile.config
+
+include $(LLVM_SRC_ROOT)/unittests/Makefile.unittest
diff --git a/unittests/DebugInfo/Makefile b/unittests/DebugInfo/Makefile
index ad3cb22bbd1..1889ad22db1 100644
--- a/unittests/DebugInfo/Makefile
+++ b/unittests/DebugInfo/Makefile
@@ -6,11 +6,10 @@
 # License. See LICENSE.TXT for details.
 #
 ##===----------------------------------------------------------------------===##
-
 LEVEL = ../..
-TESTNAME = DebugInfo
-LINK_COMPONENTS := DebugInfoDWARF object support
 
 include $(LEVEL)/Makefile.config
 
+PARALLEL_DIRS := DWARF PDB
+
 include $(LLVM_SRC_ROOT)/unittests/Makefile.unittest
diff --git a/unittests/DebugInfo/PDB/CMakeLists.txt b/unittests/DebugInfo/PDB/CMakeLists.txt
new file mode 100644
index 00000000000..91924a5a875
--- /dev/null
+++ b/unittests/DebugInfo/PDB/CMakeLists.txt
@@ -0,0 +1,11 @@
+set(LLVM_LINK_COMPONENTS
+  DebugInfoPDB
+  )
+
+set(DebugInfoPDBSources
+  PDBApiTest.cpp
+  )
+
+add_llvm_unittest(DebugInfoPDBTests
+  ${DebugInfoPDBSources}
+  )
diff --git a/unittests/DebugInfo/PDB/Makefile b/unittests/DebugInfo/PDB/Makefile
new file mode 100644
index 00000000000..eb118a3fd2b
--- /dev/null
+++ b/unittests/DebugInfo/PDB/Makefile
@@ -0,0 +1,16 @@
+##===- unittests/DebugInfo/PDB/Makefile -------------------*- Makefile -*-===##
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+##===----------------------------------------------------------------------===##
+
+LEVEL = ../../..
+TESTNAME = DebugInfoPDB
+LINK_COMPONENTS := DebugInfoPDB support
+
+include $(LEVEL)/Makefile.config
+
+include $(LLVM_SRC_ROOT)/unittests/Makefile.unittest
diff --git a/unittests/DebugInfo/PDB/PDBApiTest.cpp b/unittests/DebugInfo/PDB/PDBApiTest.cpp
new file mode 100644
index 00000000000..d8dbb7adb0a
--- /dev/null
+++ b/unittests/DebugInfo/PDB/PDBApiTest.cpp
@@ -0,0 +1,359 @@
+//===- llvm/unittest/DebugInfo/PDB/PDBApiTest.cpp -------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include <unordered_map>
+
+#include "llvm/DebugInfo/PDB/IPDBEnumChildren.h"
+#include "llvm/DebugInfo/PDB/IPDBRawSymbol.h"
+#include "llvm/DebugInfo/PDB/PDBSymbol.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolAnnotation.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolBlock.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolCompiland.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolCompilandDetails.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolCompilandEnv.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolCustom.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolData.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolExe.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolFunc.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolFuncDebugEnd.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolFuncDebugStart.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolLabel.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolPublicSymbol.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolThunk.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolTypeArray.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolTypeBaseClass.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolTypeBuiltin.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolTypeCustom.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolTypeDimension.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolTypeEnum.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolTypeFriend.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolTypeFunctionArg.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolTypeFunctionSig.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolTypeManaged.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolTypePointer.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolTypeTypedef.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolTypeUDT.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolTypeVTable.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolTypeVTableShape.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolUnknown.h"
+#include "llvm/DebugInfo/PDB/PDBSymbolUsingNamespace.h"
+#include "llvm/DebugInfo/PDB/PDBTypes.h"
+#include "gtest/gtest.h"
+using namespace llvm;
+
+namespace std {
+  template<>
+  struct hash<PDB_SymType> {
+  public:
+    std::size_t operator()(PDB_SymType Symbol) const {
+      return std::hash<int>()(static_cast<int>(Symbol));
+    }
+  };
+}
+
+namespace {
+
+#define MOCK_SYMBOL_ACCESSOR(Func)                                             \
+  auto Func() const->decltype(((IPDBRawSymbol *)nullptr)->Func()) override {   \
+    typedef decltype(IPDBRawSymbol::Func()) ReturnType;                        \
+    return ReturnType();                                                       \
+  }
+
+class MockRawSymbol : public IPDBRawSymbol {
+public:
+  MockRawSymbol(PDB_SymType SymType) : Type(SymType) {}
+
+  virtual void dump(llvm::raw_ostream &OS) const {}
+
+  virtual std::unique_ptr<IPDBEnumSymbols>
+  findChildren(PDB_SymType Type, StringRef Name,
+               PDB_NameSearchFlags Flags) const {
+    return nullptr;
+  }
+  virtual std::unique_ptr<IPDBEnumSymbols>
+  findChildrenByRVA(PDB_SymType Type, StringRef Name, PDB_NameSearchFlags Flags,
+                    uint32_t RVA) const {
+    return nullptr;
+  }
+  virtual std::unique_ptr<IPDBEnumSymbols>
+  findInlineFramesByRVA(uint32_t RVA) const {
+    return nullptr;
+  }
+
+  virtual void getDataBytes(llvm::SmallVector<uint8_t, 32> &bytes) const {}
+
+  PDB_SymType getSymTag() const override { return Type; }
+
+  MOCK_SYMBOL_ACCESSOR(getAccess)
+  MOCK_SYMBOL_ACCESSOR(getAddressOffset)
+  MOCK_SYMBOL_ACCESSOR(getAddressSection)
+  MOCK_SYMBOL_ACCESSOR(getAge)
+  MOCK_SYMBOL_ACCESSOR(getArrayIndexTypeId)
+  MOCK_SYMBOL_ACCESSOR(getBackEndBuild)
+  MOCK_SYMBOL_ACCESSOR(getBackEndMajor)
+  MOCK_SYMBOL_ACCESSOR(getBackEndMinor)
+  MOCK_SYMBOL_ACCESSOR(getBaseDataOffset)
+  MOCK_SYMBOL_ACCESSOR(getBaseDataSlot)
+  MOCK_SYMBOL_ACCESSOR(getBaseSymbolId)
+  MOCK_SYMBOL_ACCESSOR(getBuiltinType)
+  MOCK_SYMBOL_ACCESSOR(getBitPosition)
+  MOCK_SYMBOL_ACCESSOR(getCallingConvention)
+  MOCK_SYMBOL_ACCESSOR(getClassParentId)
+  MOCK_SYMBOL_ACCESSOR(getCompilerName)
+  MOCK_SYMBOL_ACCESSOR(getCount)
+  MOCK_SYMBOL_ACCESSOR(getCountLiveRanges)
+  MOCK_SYMBOL_ACCESSOR(getFrontEndBuild)
+  MOCK_SYMBOL_ACCESSOR(getFrontEndMajor)
+  MOCK_SYMBOL_ACCESSOR(getFrontEndMinor)
+  MOCK_SYMBOL_ACCESSOR(getLanguage)
+  MOCK_SYMBOL_ACCESSOR(getLexicalParentId)
+  MOCK_SYMBOL_ACCESSOR(getLibraryName)
+  MOCK_SYMBOL_ACCESSOR(getLiveRangeStartAddressOffset)
+  MOCK_SYMBOL_ACCESSOR(getLiveRangeStartAddressSection)
+  MOCK_SYMBOL_ACCESSOR(getLiveRangeStartRelativeVirtualAddress)
+  MOCK_SYMBOL_ACCESSOR(getLocalBasePointerRegisterId)
+  MOCK_SYMBOL_ACCESSOR(getLowerBoundId)
+  MOCK_SYMBOL_ACCESSOR(getMemorySpaceKind)
+  MOCK_SYMBOL_ACCESSOR(getName)
+  MOCK_SYMBOL_ACCESSOR(getNumberOfAcceleratorPointerTags)
+  MOCK_SYMBOL_ACCESSOR(getNumberOfColumns)
+  MOCK_SYMBOL_ACCESSOR(getNumberOfModifiers)
+  MOCK_SYMBOL_ACCESSOR(getNumberOfRegisterIndices)
+  MOCK_SYMBOL_ACCESSOR(getNumberOfRows)
+  MOCK_SYMBOL_ACCESSOR(getObjectFileName)
+  MOCK_SYMBOL_ACCESSOR(getOemId)
+  MOCK_SYMBOL_ACCESSOR(getOemSymbolId)
+  MOCK_SYMBOL_ACCESSOR(getOffsetInUdt)
+  MOCK_SYMBOL_ACCESSOR(getPlatform)
+  MOCK_SYMBOL_ACCESSOR(getRank)
+  MOCK_SYMBOL_ACCESSOR(getRegisterId)
+  MOCK_SYMBOL_ACCESSOR(getRegisterType)
+  MOCK_SYMBOL_ACCESSOR(getRelativeVirtualAddress)
+  MOCK_SYMBOL_ACCESSOR(getSamplerSlot)
+  MOCK_SYMBOL_ACCESSOR(getSignature)
+  MOCK_SYMBOL_ACCESSOR(getSizeInUdt)
+  MOCK_SYMBOL_ACCESSOR(getSlot)
+  MOCK_SYMBOL_ACCESSOR(getSourceFileName)
+  MOCK_SYMBOL_ACCESSOR(getStride)
+  MOCK_SYMBOL_ACCESSOR(getSubTypeId)
+  MOCK_SYMBOL_ACCESSOR(getSymbolsFileName)
+  MOCK_SYMBOL_ACCESSOR(getSymIndexId)
+  MOCK_SYMBOL_ACCESSOR(getTargetOffset)
+  MOCK_SYMBOL_ACCESSOR(getTargetRelativeVirtualAddress)
+  MOCK_SYMBOL_ACCESSOR(getTargetVirtualAddress)
+  MOCK_SYMBOL_ACCESSOR(getTargetSection)
+  MOCK_SYMBOL_ACCESSOR(getTextureSlot)
+  MOCK_SYMBOL_ACCESSOR(getTimeStamp)
+  MOCK_SYMBOL_ACCESSOR(getToken)
+  MOCK_SYMBOL_ACCESSOR(getTypeId)
+  MOCK_SYMBOL_ACCESSOR(getUavSlot)
+  MOCK_SYMBOL_ACCESSOR(getUndecoratedName)
+  MOCK_SYMBOL_ACCESSOR(getUnmodifiedTypeId)
+  MOCK_SYMBOL_ACCESSOR(getUpperBoundId)
+  MOCK_SYMBOL_ACCESSOR(getVirtualBaseDispIndex)
+  MOCK_SYMBOL_ACCESSOR(getVirtualBaseOffset)
+  MOCK_SYMBOL_ACCESSOR(getVirtualTableShapeId)
+  MOCK_SYMBOL_ACCESSOR(getDataKind)
+  MOCK_SYMBOL_ACCESSOR(getGuid)
+  MOCK_SYMBOL_ACCESSOR(getOffset)
+  MOCK_SYMBOL_ACCESSOR(getThisAdjust)
+  MOCK_SYMBOL_ACCESSOR(getVirtualBasePointerOffset)
+  MOCK_SYMBOL_ACCESSOR(getLocationType)
+  MOCK_SYMBOL_ACCESSOR(getMachineType)
+  MOCK_SYMBOL_ACCESSOR(getThunkOrdinal)
+  MOCK_SYMBOL_ACCESSOR(getLength)
+  MOCK_SYMBOL_ACCESSOR(getLiveRangeLength)
+  MOCK_SYMBOL_ACCESSOR(getVirtualAddress)
+  MOCK_SYMBOL_ACCESSOR(getUdtKind)
+  MOCK_SYMBOL_ACCESSOR(hasConstructor)
+  MOCK_SYMBOL_ACCESSOR(hasCustomCallingConvention)
+  MOCK_SYMBOL_ACCESSOR(hasFarReturn)
+  MOCK_SYMBOL_ACCESSOR(isCode)
+  MOCK_SYMBOL_ACCESSOR(isCompilerGenerated)
+  MOCK_SYMBOL_ACCESSOR(isConstType)
+  MOCK_SYMBOL_ACCESSOR(isEditAndContinueEnabled)
+  MOCK_SYMBOL_ACCESSOR(isFunction)
+  MOCK_SYMBOL_ACCESSOR(getAddressTaken)
+  MOCK_SYMBOL_ACCESSOR(getNoStackOrdering)
+  MOCK_SYMBOL_ACCESSOR(hasAlloca)
+  MOCK_SYMBOL_ACCESSOR(hasAssignmentOperator)
+  MOCK_SYMBOL_ACCESSOR(hasCTypes)
+  MOCK_SYMBOL_ACCESSOR(hasCastOperator)
+  MOCK_SYMBOL_ACCESSOR(hasDebugInfo)
+  MOCK_SYMBOL_ACCESSOR(hasEH)
+  MOCK_SYMBOL_ACCESSOR(hasEHa)
+  MOCK_SYMBOL_ACCESSOR(hasInlAsm)
+  MOCK_SYMBOL_ACCESSOR(hasInlineAttribute)
+  MOCK_SYMBOL_ACCESSOR(hasInterruptReturn)
+  MOCK_SYMBOL_ACCESSOR(hasLongJump)
+  MOCK_SYMBOL_ACCESSOR(hasManagedCode)
+  MOCK_SYMBOL_ACCESSOR(hasNestedTypes)
+  MOCK_SYMBOL_ACCESSOR(hasNoInlineAttribute)
+  MOCK_SYMBOL_ACCESSOR(hasNoReturnAttribute)
+  MOCK_SYMBOL_ACCESSOR(hasOptimizedCodeDebugInfo)
+  MOCK_SYMBOL_ACCESSOR(hasOverloadedOperator)
+  MOCK_SYMBOL_ACCESSOR(hasSEH)
+  MOCK_SYMBOL_ACCESSOR(hasSecurityChecks)
+  MOCK_SYMBOL_ACCESSOR(hasSetJump)
+  MOCK_SYMBOL_ACCESSOR(hasStrictGSCheck)
+  MOCK_SYMBOL_ACCESSOR(isAcceleratorGroupSharedLocal)
+  MOCK_SYMBOL_ACCESSOR(isAcceleratorPointerTagLiveRange)
+  MOCK_SYMBOL_ACCESSOR(isAcceleratorStubFunction)
+  MOCK_SYMBOL_ACCESSOR(isAggregated)
+  MOCK_SYMBOL_ACCESSOR(isIntroVirtualFunction)
+  MOCK_SYMBOL_ACCESSOR(isCVTCIL)
+  MOCK_SYMBOL_ACCESSOR(isConstructorVirtualBase)
+  MOCK_SYMBOL_ACCESSOR(isCxxReturnUdt)
+  MOCK_SYMBOL_ACCESSOR(isDataAligned)
+  MOCK_SYMBOL_ACCESSOR(isHLSLData)
+  MOCK_SYMBOL_ACCESSOR(isHotpatchable)
+  MOCK_SYMBOL_ACCESSOR(isIndirectVirtualBaseClass)
+  MOCK_SYMBOL_ACCESSOR(isInterfaceUdt)
+  MOCK_SYMBOL_ACCESSOR(isIntrinsic)
+  MOCK_SYMBOL_ACCESSOR(isLTCG)
+  MOCK_SYMBOL_ACCESSOR(isLocationControlFlowDependent)
+  MOCK_SYMBOL_ACCESSOR(isMSILNetmodule)
+  MOCK_SYMBOL_ACCESSOR(isMatrixRowMajor)
+  MOCK_SYMBOL_ACCESSOR(isManagedCode)
+  MOCK_SYMBOL_ACCESSOR(isMSILCode)
+  MOCK_SYMBOL_ACCESSOR(isMultipleInheritance)
+  MOCK_SYMBOL_ACCESSOR(isNaked)
+  MOCK_SYMBOL_ACCESSOR(isNested)
+  MOCK_SYMBOL_ACCESSOR(isOptimizedAway)
+  MOCK_SYMBOL_ACCESSOR(isPacked)
+  MOCK_SYMBOL_ACCESSOR(isPointerBasedOnSymbolValue)
+  MOCK_SYMBOL_ACCESSOR(isPointerToDataMember)
+  MOCK_SYMBOL_ACCESSOR(isPointerToMemberFunction)
+  MOCK_SYMBOL_ACCESSOR(isPureVirtual)
+  MOCK_SYMBOL_ACCESSOR(isRValueReference)
+  MOCK_SYMBOL_ACCESSOR(isRefUdt)
+  MOCK_SYMBOL_ACCESSOR(isReference)
+  MOCK_SYMBOL_ACCESSOR(isRestrictedType)
+  MOCK_SYMBOL_ACCESSOR(isReturnValue)
+  MOCK_SYMBOL_ACCESSOR(isSafeBuffers)
+  MOCK_SYMBOL_ACCESSOR(isScoped)
+  MOCK_SYMBOL_ACCESSOR(isSdl)
+  MOCK_SYMBOL_ACCESSOR(isSingleInheritance)
+  MOCK_SYMBOL_ACCESSOR(isSplitted)
+  MOCK_SYMBOL_ACCESSOR(isStatic)
+  MOCK_SYMBOL_ACCESSOR(hasPrivateSymbols)
+  MOCK_SYMBOL_ACCESSOR(isUnalignedType)
+  MOCK_SYMBOL_ACCESSOR(isUnreached)
+  MOCK_SYMBOL_ACCESSOR(isValueUdt)
+  MOCK_SYMBOL_ACCESSOR(isVirtual)
+  MOCK_SYMBOL_ACCESSOR(isVirtualBaseClass)
+  MOCK_SYMBOL_ACCESSOR(isVirtualInheritance)
+  MOCK_SYMBOL_ACCESSOR(isVolatileType)
+
+private:
+  PDB_SymType Type;
+};
+
+class PDBApiTest : public testing::Test {
+public:
+  std::unordered_map<PDB_SymType, std::unique_ptr<PDBSymbol>> SymbolMap;
+
+  void SetUp() override {
+    InsertItemWithTag(PDB_SymType::None);
+    InsertItemWithTag(PDB_SymType::Exe);
+    InsertItemWithTag(PDB_SymType::Compiland);
+    InsertItemWithTag(PDB_SymType::CompilandDetails);
+    InsertItemWithTag(PDB_SymType::CompilandEnv);
+    InsertItemWithTag(PDB_SymType::Function);
+    InsertItemWithTag(PDB_SymType::Block);
+    InsertItemWithTag(PDB_SymType::Data);
+    InsertItemWithTag(PDB_SymType::Annotation);
+    InsertItemWithTag(PDB_SymType::Label);
+    InsertItemWithTag(PDB_SymType::PublicSymbol);
+    InsertItemWithTag(PDB_SymType::UDT);
+    InsertItemWithTag(PDB_SymType::Enum);
+    InsertItemWithTag(PDB_SymType::FunctionSig);
+    InsertItemWithTag(PDB_SymType::PointerType);
+    InsertItemWithTag(PDB_SymType::ArrayType);
+    InsertItemWithTag(PDB_SymType::BuiltinType);
+    InsertItemWithTag(PDB_SymType::Typedef);
+    InsertItemWithTag(PDB_SymType::BaseClass);
+    InsertItemWithTag(PDB_SymType::Friend);
+    InsertItemWithTag(PDB_SymType::FunctionArg);
+    InsertItemWithTag(PDB_SymType::FuncDebugStart);
+    InsertItemWithTag(PDB_SymType::FuncDebugEnd);
+    InsertItemWithTag(PDB_SymType::UsingNamespace);
+    InsertItemWithTag(PDB_SymType::VTableShape);
+    InsertItemWithTag(PDB_SymType::VTable);
+    InsertItemWithTag(PDB_SymType::Custom);
+    InsertItemWithTag(PDB_SymType::Thunk);
+    InsertItemWithTag(PDB_SymType::CustomType);
+    InsertItemWithTag(PDB_SymType::ManagedType);
+    InsertItemWithTag(PDB_SymType::Dimension);
+    InsertItemWithTag(PDB_SymType::Max);
+  }
+
+private:
+  void InsertItemWithTag(PDB_SymType Tag) {
+    auto RawSymbol = std::unique_ptr<IPDBRawSymbol>(new MockRawSymbol(Tag));
+    auto Symbol = PDBSymbol::create(std::move(RawSymbol));
+    SymbolMap.insert(std::make_pair(Tag, std::move(Symbol)));
+  }
+
+public:
+  template <class ExpectedType> void VerifyDyncast(PDB_SymType Tag) {
+    for (auto item = SymbolMap.begin(); item != SymbolMap.end(); ++item) {
+      EXPECT_EQ(item->first == Tag, llvm::isa<ExpectedType>(*item->second));
+    }
+  }
+
+  void VerifyUnknownDyncasts() {
+    for (auto item = SymbolMap.begin(); item != SymbolMap.end(); ++item) {
+      bool should_match = false;
+      if (item->first == PDB_SymType::None || item->first >= PDB_SymType::Max)
+        should_match = true;
+
+      EXPECT_EQ(should_match, llvm::isa<PDBSymbolUnknown>(*item->second));
+    }
+  }
+};
+
+TEST_F(PDBApiTest, Dyncast) {
+
+  // Most of the types have a one-to-one mapping between Tag and concrete type.
+  VerifyDyncast<PDBSymbolExe>(PDB_SymType::Exe);
+  VerifyDyncast<PDBSymbolCompiland>(PDB_SymType::Compiland);
+  VerifyDyncast<PDBSymbolCompilandDetails>(PDB_SymType::CompilandDetails);
+  VerifyDyncast<PDBSymbolCompilandEnv>(PDB_SymType::CompilandEnv);
+  VerifyDyncast<PDBSymbolFunc>(PDB_SymType::Function);
+  VerifyDyncast<PDBSymbolBlock>(PDB_SymType::Block);
+  VerifyDyncast<PDBSymbolData>(PDB_SymType::Data);
+  VerifyDyncast<PDBSymbolAnnotation>(PDB_SymType::Annotation);
+  VerifyDyncast<PDBSymbolLabel>(PDB_SymType::Label);
+  VerifyDyncast<PDBSymbolPublicSymbol>(PDB_SymType::PublicSymbol);
+  VerifyDyncast<PDBSymbolTypeUDT>(PDB_SymType::UDT);
+  VerifyDyncast<PDBSymbolTypeEnum>(PDB_SymType::Enum);
+  VerifyDyncast<PDBSymbolTypeFunctionSig>(PDB_SymType::FunctionSig);
+  VerifyDyncast<PDBSymbolTypePointer>(PDB_SymType::PointerType);
+  VerifyDyncast<PDBSymbolTypeArray>(PDB_SymType::ArrayType);
+  VerifyDyncast<PDBSymbolTypeBuiltin>(PDB_SymType::BuiltinType);
+  VerifyDyncast<PDBSymbolTypeTypedef>(PDB_SymType::Typedef);
+  VerifyDyncast<PDBSymbolTypeBaseClass>(PDB_SymType::BaseClass);
+  VerifyDyncast<PDBSymbolTypeFriend>(PDB_SymType::Friend);
+  VerifyDyncast<PDBSymbolTypeFunctionArg>(PDB_SymType::FunctionArg);
+  VerifyDyncast<PDBSymbolFuncDebugStart>(PDB_SymType::FuncDebugStart);
+  VerifyDyncast<PDBSymbolFuncDebugEnd>(PDB_SymType::FuncDebugEnd);
+  VerifyDyncast<PDBSymbolUsingNamespace>(PDB_SymType::UsingNamespace);
+  VerifyDyncast<PDBSymbolTypeVTableShape>(PDB_SymType::VTableShape);
+  VerifyDyncast<PDBSymbolTypeVTable>(PDB_SymType::VTable);
+  VerifyDyncast<PDBSymbolCustom>(PDB_SymType::Custom);
+  VerifyDyncast<PDBSymbolThunk>(PDB_SymType::Thunk);
+  VerifyDyncast<PDBSymbolTypeCustom>(PDB_SymType::CustomType);
+  VerifyDyncast<PDBSymbolTypeManaged>(PDB_SymType::ManagedType);
+  VerifyDyncast<PDBSymbolTypeDimension>(PDB_SymType::Dimension);
+
+  VerifyUnknownDyncasts();
+}
+
+} // end anonymous namespace