Add LLVM-style RTTI to DIContext/DWARFContext classes

llvm-svn: 187790
diff --git a/llvm/include/llvm/DebugInfo/DIContext.h b/llvm/include/llvm/DebugInfo/DIContext.h
index bdd8dce..4bb7c77 100644
--- a/llvm/include/llvm/DebugInfo/DIContext.h
+++ b/llvm/include/llvm/DebugInfo/DIContext.h
@@ -21,6 +21,7 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Object/ObjectFile.h"
 #include "llvm/Object/RelocVisitor.h"
+#include "llvm/Support/Casting.h"
 #include "llvm/Support/DataTypes.h"
 
 namespace llvm {
@@ -122,6 +123,12 @@
 
 class DIContext {
 public:
+  enum DIContextKind {
+    CK_DWARF
+  };
+  DIContextKind getKind() const { return Kind; }
+
+  DIContext(DIContextKind K) : Kind(K) {}
   virtual ~DIContext();
 
   /// getDWARFContext - get a context for binary DWARF data.
@@ -135,6 +142,8 @@
       uint64_t Size, DILineInfoSpecifier Specifier = DILineInfoSpecifier()) = 0;
   virtual DIInliningInfo getInliningInfoForAddress(uint64_t Address,
       DILineInfoSpecifier Specifier = DILineInfoSpecifier()) = 0;
+private:
+  const DIContextKind Kind;
 };
 
 }
diff --git a/llvm/lib/DebugInfo/DWARFContext.h b/llvm/lib/DebugInfo/DWARFContext.h
index 058476e..5d8f714 100644
--- a/llvm/lib/DebugInfo/DWARFContext.h
+++ b/llvm/lib/DebugInfo/DWARFContext.h
@@ -48,7 +48,12 @@
   void parseDWOCompileUnits();
 
 public:
-  DWARFContext() {}
+  DWARFContext() : DIContext(CK_DWARF) {}
+
+  static bool classof(const DIContext *DICtx) {
+    return DICtx->getKind() == CK_DWARF;
+  }
+
   virtual void dump(raw_ostream &OS, DIDumpType DumpType = DIDT_All);
 
   /// Get the number of compile units in this context.