Add DemangleSymbol function

Author: Vipul-Cariappa

include/clang/Interpreter/CppInterOp.h

@@ -185,6 +185,9 @@ namespace Cpp {
   ///\returns the version string information of the library.
   CPPINTEROP_API std::string GetVersion();
 
+  ///\returns the demangled representation of the given mangled_name
+  CPPINTEROP_API std::string DemangleSymbol(const std::string& mangled_name);
+
   /// Enables or disables the debugging printouts on stderr.
   /// Debugging output can be enabled also by the environment variable
   /// CPPINTEROP_EXTRA_INTERPRETER_ARGS. For example,

lib/Interpreter/CppInterOp.cpp

@@ -31,6 +31,7 @@
 
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/Demangle/Demangle.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_os_ostream.h"
@@ -155,6 +156,25 @@ namespace Cpp {
     return fullVersion + "[" + clang::getClangFullVersion() + "])\n";
   }
 
+  std::string DemangleSymbol(const std::string& mangled_name) {
+#if CLANG_VERSION_MAJOR > 16
+#if defined(MSVC)
+    std::string demangle = microsoftDemangle(mangled_name, nullptr, nullptr);
+#else
+    std::string demangle = itaniumDemangle(mangled_name);
+#endif
+#else
+#ifdef MSVC
+    std::string demangle = microsoftDemangle(mangled_name.c_str(), nullptr,
+                                             nullptr, nullptr, nullptr);
+#else
+    std::string demangle =
+        itaniumDemangle(mangled_name.c_str(), nullptr, nullptr, nullptr);
+#endif
+#endif
+    return demangle;
+  }
+
   void EnableDebugOutput(bool value/* =true*/) {
     llvm::DebugFlag = value;
   }

unittests/CppInterOp/ScopeReflectionTest.cpp

@@ -17,6 +17,38 @@ using namespace TestUtils;
 using namespace llvm;
 using namespace clang;
 
+TEST(ScopeReflectionTest, DemangleSymbol) {
+  if (llvm::sys::RunningOnValgrind())
+    GTEST_SKIP() << "XFAIL due to Valgrind report";
+
+  std::string code = R"(
+    #include <string>
+    #include <typeinfo>
+
+    class C { public: virtual ~C() {} };
+    namespace scope {
+        class C { public: virtual ~C() {} };
+    }
+
+    const char* c = typeid(C).name();
+    const char* scope_c = typeid(scope::C).name();
+  )";
+
+  EXPECT_EQ(Cpp::Declare(code.c_str()), 0);
+
+  Cpp::TCppScope_t C = Cpp::GetNamed("C");
+  Cpp::TCppScope_t scope_C = Cpp::GetNamed("C", Cpp::GetNamed("scope"));
+  Cpp::TCppScope_t c = Cpp::GetNamed("c");
+  Cpp::TCppScope_t scope_c = Cpp::GetNamed("scope_c");
+
+  char* mangled_C = *(char**)Cpp::GetVariableOffset(c);
+  char* mangled_scope_C = *(char**)Cpp::GetVariableOffset(scope_c);
+
+  EXPECT_EQ(Cpp::DemangleSymbol(mangled_C), Cpp::GetQualifiedCompleteName(C));
+  EXPECT_EQ(Cpp::DemangleSymbol(mangled_scope_C),
+            Cpp::GetQualifiedCompleteName(scope_C));
+}
+
 TEST(ScopeReflectionTest, IsAggregate) {
   std::vector<Decl *> Decls;
   std::string code = R"(