misc fixes to support building with -Wundef

Reviewed By: Gownta

Differential Revision: D33476592

fbshipit-source-id: 9e66fdf07ce88c507cfb32406b113e1c05131c8c

folly/Memory.h

@@ -49,7 +49,7 @@ inline void* allocateBytes(size_t n) {
 }
 
 inline void deallocateBytes(void* p, size_t n) {
-#if __cpp_sized_deallocation
+#if defined(__cpp_sized_deallocation)
   return ::operator delete(p, n);
 #else
   (void)n;
@@ -57,11 +57,12 @@ inline void deallocateBytes(void* p, size_t n) {
 #endif
 }
 
-#if _POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600 ||   \
-    (defined(__ANDROID__) && (__ANDROID_API__ > 16)) ||     \
-    (defined(__APPLE__) &&                                  \
-     (__MAC_OS_X_VERSION_MIN_REQUIRED >= __MAC_10_6 ||      \
-      __IPHONE_OS_VERSION_MIN_REQUIRED >= __IPHONE_3_0)) || \
+#if (defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 200112L) || \
+    (defined(_XOPEN_SOURCE) && _XOPEN_SOURCE >= 600) ||         \
+    (defined(__ANDROID__) && (__ANDROID_API__ > 16)) ||         \
+    (defined(__APPLE__) &&                                      \
+     (__MAC_OS_X_VERSION_MIN_REQUIRED >= __MAC_10_6 ||          \
+      __IPHONE_OS_VERSION_MIN_REQUIRED >= __IPHONE_3_0)) ||     \
     defined(__FreeBSD__) || defined(__wasm32__)
 
 inline void* aligned_malloc(size_t size, size_t align) {
@@ -118,7 +119,7 @@ void rawOverAlignedImpl(Alloc const& alloc, size_t n, void*& raw) {
   static_assert(
       sizeof(BaseType) == kBaseAlign && alignof(BaseType) == kBaseAlign, "");
 
-#if __cpp_sized_deallocation
+#if defined(__cpp_sized_deallocation)
   if (kCanBypass && kAlign == kBaseAlign) {
     // until std::allocator uses sized deallocation, it is worth the
     // effort to bypass it when we are able
@@ -357,7 +358,7 @@ std::weak_ptr<T> to_weak_ptr(const std::shared_ptr<T>& ptr) {
   return ptr;
 }
 
-#if __GLIBCXX__
+#if defined(__GLIBCXX__)
 namespace detail {
 void weak_ptr_set_stored_ptr(std::weak_ptr<void>& w, void* ptr);
 
@@ -396,7 +397,7 @@ template struct GenerateWeakPtrInternalsAccessor<
  */
 template <typename T, typename U>
 std::weak_ptr<U> to_weak_ptr_aliasing(const std::shared_ptr<T>& r, U* ptr) {
-#if __GLIBCXX__
+#if defined(__GLIBCXX__)
   std::weak_ptr<void> wv(r);
   detail::weak_ptr_set_stored_ptr(wv, ptr);
   return reinterpret_cast<std::weak_ptr<U>&&>(wv);

folly/Portability.h

@@ -35,7 +35,7 @@ static_assert(__GNUC__ >= 5, "__GNUC__ >= 5");
 
 // Unaligned loads and stores
 namespace folly {
-#if FOLLY_HAVE_UNALIGNED_ACCESS
+#if defined(FOLLY_HAVE_UNALIGNED_ACCESS) && FOLLY_HAVE_UNALIGNED_ACCESS
 constexpr bool kHasUnalignedAccess = true;
 #else
 constexpr bool kHasUnalignedAccess = false;
@@ -230,7 +230,7 @@ constexpr bool kIsSanitize = false;
 
 // If the new c++ ABI is used, __cxx11 inline namespace needs to be added to
 // some types, e.g. std::list.
-#if _GLIBCXX_USE_CXX11_ABI
+#if defined(_GLIBCXX_USE_CXX11_ABI) && _GLIBCXX_USE_CXX11_ABI
 #define FOLLY_GLIBCXX_NAMESPACE_CXX11_BEGIN \
   inline _GLIBCXX_BEGIN_NAMESPACE_CXX11
 #define FOLLY_GLIBCXX_NAMESPACE_CXX11_END _GLIBCXX_END_NAMESPACE_CXX11
@@ -266,10 +266,11 @@ constexpr bool kIsSanitize = false;
 #endif
 
 // Define FOLLY_HAS_EXCEPTIONS
-#if __cpp_exceptions >= 199711 || FOLLY_HAS_FEATURE(cxx_exceptions)
+#if (defined(__cpp_exceptions) && __cpp_exceptions >= 199711) || \
+    FOLLY_HAS_FEATURE(cxx_exceptions)
 #define FOLLY_HAS_EXCEPTIONS 1
 #elif __GNUC__
-#if __EXCEPTIONS
+#if defined(__EXCEPTIONS) && __EXCEPTIONS
 #define FOLLY_HAS_EXCEPTIONS 1
 #else // __EXCEPTIONS
 #define FOLLY_HAS_EXCEPTIONS 0
@@ -459,19 +460,19 @@ constexpr bool kIsAppleMacOS = FOLLY_APPLE_MACOS == 1;
 constexpr bool kIsAppleTVOS = FOLLY_APPLE_TVOS == 1;
 constexpr bool kIsAppleWatchOS = FOLLY_APPLE_WATCHOS == 1;
 
-#if __GLIBCXX__
+#if defined(__GLIBCXX__)
 constexpr auto kIsGlibcxx = true;
 #else
 constexpr auto kIsGlibcxx = false;
 #endif
 
-#if __GLIBCXX__ && _GLIBCXX_RELEASE // major version, 7+
+#if defined(__GLIBCXX__) && _GLIBCXX_RELEASE // major version, 7+
 constexpr auto kGlibcxxVer = _GLIBCXX_RELEASE;
 #else
 constexpr auto kGlibcxxVer = 0;
 #endif
 
-#if __GLIBCXX__ && defined(_GLIBCXX_ASSERTIONS)
+#if defined(__GLIBCXX__) && defined(_GLIBCXX_ASSERTIONS)
 constexpr auto kGlibcxxAssertions = true;
 #else
 constexpr auto kGlibcxxAssertions = false;
@@ -483,7 +484,7 @@ constexpr auto kIsLibcpp = true;
 constexpr auto kIsLibcpp = false;
 #endif
 
-#if __GLIBCXX__
+#if defined(__GLIBCXX__)
 constexpr auto kIsLibstdcpp = true;
 #else
 constexpr auto kIsLibstdcpp = false;

folly/container/detail/F14IntrinsicsAvailability.h

@@ -38,7 +38,7 @@
 #define FOLLY_F14_VECTOR_INTRINSICS_AVAILABLE 0
 #endif
 
-#if FOLLY_SSE_PREREQ(4, 2) || __ARM_FEATURE_CRC32
+#if FOLLY_SSE_PREREQ(4, 2) || defined(__ARM_FEATURE_CRC32)
 #define FOLLY_F14_CRC_INTRINSIC_AVAILABLE 1
 #else
 #define FOLLY_F14_CRC_INTRINSIC_AVAILABLE 0

folly/portability/Asm.h

@@ -36,7 +36,8 @@ inline void asm_volatile_memory() {
 inline void asm_volatile_pause() {
 #if defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_X64))
   ::_mm_pause();
-#elif defined(__i386__) || FOLLY_X64 || (__mips_isa_rev > 1)
+#elif defined(__i386__) || FOLLY_X64 || \
+    (defined(__mips_isa_rev) && __mips_isa_rev > 1)
   asm volatile("pause");
 #elif FOLLY_AARCH64 || (defined(__arm__) && !(__ARM_ARCH < 7))
   asm volatile("yield");

folly/portability/Malloc.h

@@ -21,7 +21,8 @@
 #include <folly/CPortability.h>
 #include <folly/portability/Config.h>
 
-#if (defined(USE_JEMALLOC) || FOLLY_USE_JEMALLOC) && !defined(FOLLY_SANITIZE)
+#if (defined(USE_JEMALLOC) || defined(FOLLY_USE_JEMALLOC)) && \
+    !defined(FOLLY_SANITIZE)
 #if defined(FOLLY_ASSUME_NO_JEMALLOC)
 #error \
     "Both USE_JEMALLOC/FOLLY_USE_JEMALLOC and FOLLY_ASSUME_NO_JEMALLOC defined"