atomicops-internals-windows.h: Don't declare intrincs when using Clang

Clang provides inline definitions in its Intrin.h file. If we declare our
own intrinsic functions in base::subtle::, we will use those instead,
and fail to link because they are not defined anywhere.

BUG=82385

Review URL: https://codereview.chromium.org/150823003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@248240 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 12 insertions, 4 deletions

diff --git a/third_party/tcmalloc/chromium/src/base/atomicops-internals-windows.h b/third_party/tcmalloc/chromium/src/base/atomicops-internals-windows.h
index 6a38bad..e4d6bb9 100644
--- a/third_party/tcmalloc/chromium/src/base/atomicops-internals-windows.h
+++ b/third_party/tcmalloc/chromium/src/base/atomicops-internals-windows.h
@@ -86,21 +86,29 @@ inline LONG FastInterlockedExchangeAdd(volatile LONG* ptr, LONG increment) {
 // have conflicting declarations of some intrinsics, breaking
 // compilation.  So we declare the intrinsics we need ourselves.  See
 //   http://connect.microsoft.com/VisualStudio/feedback/details/262047
+
+// Don't declare the intrinsics if using Clang. Clang provides inline
+// definitions in its Intrin.h.
+#ifndef __clang__
 LONG _InterlockedCompareExchange(volatile LONG* ptr, LONG newval, LONG oldval);
 #pragma intrinsic(_InterlockedCompareExchange)
+
+LONG _InterlockedExchange(volatile LONG* ptr, LONG newval);
+#pragma intrinsic(_InterlockedExchange)
+
+LONG _InterlockedExchangeAdd(volatile LONG* ptr, LONG increment);
+#pragma intrinsic(_InterlockedExchangeAdd)
+#endif
+
 inline LONG FastInterlockedCompareExchange(volatile LONG* ptr,
                                            LONG newval, LONG oldval) {
   return _InterlockedCompareExchange(ptr, newval, oldval);
 }
 
-LONG _InterlockedExchange(volatile LONG* ptr, LONG newval);
-#pragma intrinsic(_InterlockedExchange)
 inline LONG FastInterlockedExchange(volatile LONG* ptr, LONG newval) {
   return _InterlockedExchange(ptr, newval);
 }
 
-LONG _InterlockedExchangeAdd(volatile LONG* ptr, LONG increment);
-#pragma intrinsic(_InterlockedExchangeAdd)
 inline LONG FastInterlockedExchangeAdd(volatile LONG* ptr, LONG increment) {
   return _InterlockedExchangeAdd(ptr, increment);
 }