InstanceCounter/Oilpan GC tracing: Add clang support

Source/wtf/InstanceCounter.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 19 matching lines @@
 #include "wtf/StdLibExtras.h"
 #include "wtf/ThreadingPrimitives.h"
 #include "wtf/text/StringBuilder.h"
 #include "wtf/text/StringHash.h"
 #include "wtf/text/WTFString.h"
 
 namespace WTF {
 
 #if ENABLE(INSTANCE_COUNTER) || ENABLE(GC_TRACING)
 
-#if COMPILER(GCC)
+#if COMPILER(CLANG)
+const size_t extractNameFunctionPrefixLength = sizeof("const char *WTF::extractNameFunction() [T = ") - 1;
+const size_t extractNameFunctionPostfixLength = 1;
+#elif COMPILER(GCC)
 const size_t extractNameFunctionPrefixLength = sizeof("const char* WTF::extractNameFunction() [with T = ") - 1;
 const size_t extractNameFunctionPostfixLength = 1;
 #else
 #warning "Extracting typename in a compiler other than GCC isn't supported atm"
 #endif
 
 // This function is used to stringify a typename T without using RTTI.
 // The result of extractNameFunction<T>() is given as |funcName|. |extractTypeNameFromFunctionName| then extracts a typename string from |funcName|.
 String extractTypeNameFromFunctionName(const char* funcName)
 {
-#if COMPILER(GCC)
+#if COMPILER(CLANG) || COMPILER(GCC)
     size_t funcNameLength = strlen(funcName);
     ASSERT(funcNameLength > extractNameFunctionPrefixLength + 1);
 
     const char* funcNameWithoutPrefix = funcName + extractNameFunctionPrefixLength;
     return String(funcNameWithoutPrefix, funcNameLength - extractNameFunctionPrefixLength - extractNameFunctionPostfixLength /* last ] */);
 #else
     return String();
 #endif
 }
 
@@ skipping 77 matching lines @@
 #else
 
 String dumpRefCountedInstanceCounts()
 {
     return String("{}");
 }
 
 #endif // ENABLE(INSTANCE_COUNTER) || ENABLE(GC_TRACING)
 
 } // namespace WTF