Subzero: Second attempt at fixing MacOS 10.6 build.

src/IceTLS.h

Index: src/IceTLS.h
diff --git a/src/IceTLS.h b/src/IceTLS.h
new file mode 100644
index 0000000000000000000000000000000000000000..b0f1a23117d3b0fabe44087d27eac1fd04cc9edf
--- /dev/null
+++ b/src/IceTLS.h
@@ -0,0 +1,79 @@
+//===- subzero/src/IceTLS.h - thread_local workaround -----------*- C++ -*-===//
+//
+//                        The Subzero Code Generator
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines macros for working around the lack of support for
+// thread_local in MacOS 10.6.  It assumes std::thread is written in
+// terms of pthread.  Define ICE_THREAD_LOCAL_HACK to enable the
+// pthread workarounds.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SUBZERO_SRC_ICETLS_H
+#define SUBZERO_SRC_ICETLS_H
+
+#if defined(_MSC_VER)
+#define ICE_ATTRIBUTE_TLS __declspec(thread)
+#else // !_MSC_VER
+#define ICE_ATTRIBUTE_TLS thread_local
+#endif // !_MSC_VER
+
+// Defines 4 macros for unifying thread_local and pthread:
+//
+// ICE_TLS_DECLARE_FIELD(Type, FieldName): Declare a static
+// thread_local field inside the current class definition.  "Type"
+// needs to be a pointer type, such as int* or class Foo*.
+//
+// ICE_TLS_DEFINE_FIELD(Type, ClassName, FieldName): Define a static
+// thread_local field outside of its class definition, and initialize
+// it to nullptr.
+//
+// ICE_TLS_GET_FIELD(Type, FieldName): Read the value of the static
+// thread_local field.  Must be done within the context of its class.
+//
+// ICE_TLS_SET_FIELD(FieldName, Value): Write a value into the static
+// thread_local field.  Must be done within the context of its class.
+
+#ifdef ICE_THREAD_LOCAL_HACK
+
+// For a static thread_local field F of a class C, instead of
+// declaring and defining C::F, we create two static fields:
+//   static pthread_key_t F__key;
+//   static int F__dummy;
+//
+// The F__dummy field is just used to hold the result of the
+// pthread_key_create() call, which is executed as a static
+// initializer.  The F__key field is used as the argument to
+// pthread_getspecific() and pthread_setspecific().
+
+#include <pthread.h>
+
+#define ICE_TLS_DECLARE_FIELD(Type, FieldName)                                 \
+  static pthread_key_t FieldName##__key;                                       \
+  static int FieldName##__dummy
+#define ICE_TLS_DEFINE_FIELD(Type, ClassName, FieldName)                       \
+  pthread_key_t ClassName::FieldName##__key;                                   \
+  int ClassName::FieldName##__dummy =                                          \
+      pthread_key_create(&ClassName::FieldName##__key, nullptr)
+#define ICE_TLS_GET_FIELD(Type, FieldName)                                     \
+  static_cast<Type>(pthread_getspecific(FieldName##__key))

[JF, 2015/01/25 04:37:01]

Small thing I just thought about to make the diff in other files smaller:
DECLARE_FIELD can do:
  typedef FieldName##__type Type;

And then GET_FIELD doesn't need a Type parameter. DEFINE_FIELD should probably
still have it since the TLS-hack-less version of the code does have the type.

[Jim Stichnoth, 2015/01/25 18:58:40]

Very nice, done.

+#define ICE_TLS_SET_FIELD(FieldName, Value)                                    \
+  pthread_setspecific(FieldName##__key, (Value))
+
+#else // !ICE_THREAD_LOCAL_HACK
+
+#define ICE_TLS_DECLARE_FIELD(Type, FieldName)                                 \
+  static ICE_ATTRIBUTE_TLS Type FieldName
+#define ICE_TLS_DEFINE_FIELD(Type, ClassName, FieldName)                       \
+  ICE_ATTRIBUTE_TLS Type ClassName::FieldName = nullptr
+#define ICE_TLS_GET_FIELD(Type, FieldName) (FieldName)
+#define ICE_TLS_SET_FIELD(FieldName, Value) (FieldName = (Value))
+
+#endif // !ICE_THREAD_LOCAL_HACK
+
+#endif // SUBZERO_SRC_ICETLS_H