Add a class for supporting platform independent thread-local storage.

Windows people, please double-check/patch this.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74209 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/System/ThreadLocal.h

@@ -0,0 +1,41 @@
+//===- llvm/System/ThreadLocal.h - Thread Local Data ------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares the llvm::sys::ThreadLocal class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SYSTEM_THREAD_LOCAL_H
+#define LLVM_SYSTEM_THREAD_LOCAL_H
+
+#include "llvm/System/Threading.h"
+#include <cassert>
+
+namespace llvm {
+  namespace sys {
+    class ThreadLocalImpl {
+      void* data;
+    public:
+      ThreadLocalImpl();
+      virtual ~ThreadLocalImpl();
+      void setInstance(void* d);
+      void* getInstance();
+    };
+    
+    template<class T>
+    class ThreadLocal : public ThreadLocalImpl {
+    public:
+      ThreadLocal() : ThreadLocalImpl() { }
+      T* get() { return static_cast<T*>(getInstance()); }
+      void set(T* d) { setInstance(d); }
+    };
+  }
+}
+
+#endif