Enable unknown-pragmas warning for clang

cmake/ConfigureCompiler.cmake

@@ -287,7 +287,6 @@ else()
       -Wno-format
       -Wno-sign-compare
       -Wno-undefined-var-template
-      -Wno-unknown-pragmas
       -Wno-unknown-warning-option
       -Wno-unused-parameter
       )

fdbclient/VersionedMap.h

@@ -38,7 +38,9 @@
 // PTree also supports efficient finger searches.
 namespace PTreeImpl {
 
+#ifdef _MSC_VER
 #pragma warning(disable : 4800)
+#endif
 
 template <class T>
 struct PTree : public ReferenceCounted<PTree<T>>, FastAllocated<PTree<T>>, NonCopyable {

flow/actorcompiler.h

@@ -70,4 +70,6 @@ T waitNext(const FutureStream<T>&);
 #define THIS_ADDR uintptr_t(nullptr)
 #endif
 
+#ifdef _MSC_VER
 #pragma warning(disable : 4355) // 'this' : used in base member initializer list
+#endif

flow/flow.h

@@ -24,10 +24,12 @@
 #include "flow/FastRef.h"
 #pragma once
 
+#ifdef _MSC_VER
 #pragma warning(disable : 4244 4267) // SOMEDAY: Carefully check for integer overflow issues (e.g. size_t to int
 // conversions like this suppresses)
 #pragma warning(disable : 4345)
 #pragma warning(error : 4239)
+#endif
 
 #include <vector>
 #include <queue>

flow/genericactors.actor.h

@@ -37,7 +37,10 @@
 #include "flow/Util.h"
 #include "flow/IndexedSet.h"
 #include "flow/actorcompiler.h" // This must be the last #include.
+
+#ifdef _MSC_VER
 #pragma warning(disable : 4355) // 'this' : used in base member initializer list
+#endif
 
 ACTOR template <class T, class X>
 Future<T> traceAfter(Future<T> what, const char* type, const char* key, X value, bool traceErrors = false) {

flow/serialize.h

@@ -268,7 +268,9 @@ inline void load(Archive& ar, std::map<K, V>& value) {
 	ASSERT(ar.protocolVersion().isValid());
 }
 
+#ifdef _MSC_VER
 #pragma intrinsic(memcpy)
+#endif
 
 #if VALGRIND
 static bool valgrindCheck(const void* data, int bytes, const char* context) {