Don't wrap feature detection macros with QT_HAS_FOO() variants

Using wrappers for these macros is problematic when for example passing the
-frewrite-includes flag to preprocess sources before shipping off to distcc
or Icecream. It will also start producing warnings when compilers implement
http://eel.is/c++draft/cpp.cond#7.sentence-2. See for example
https://reviews.llvm.org/D49091

Both https://clang.llvm.org/docs/LanguageExtensions.html and the SD-6 document at
https://isocpp.org/std/standing-documents/sd-6-sg10-feature-test-recommendations
recommend defining '__has_foo(x) 0' as a fallback for compilers without the
macros, so that's what we go for.

Change-Id: I0298cd3b4a6ff6618821e34642a5ddd6728be767
Reviewed-by: Alex Richardson <arichardson.kde@gmail.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/corelib/global/qendian.h b/src/corelib/global/qendian.h
index 5cd9d3160b..257efbbdbe 100644
--- a/src/corelib/global/qendian.h
+++ b/src/corelib/global/qendian.h
@@ -66,7 +66,7 @@ template <typename T> Q_ALWAYS_INLINE void qToUnaligned(const T src, void *dest)
     // Using sizeof(T) inside memcpy function produces internal compiler error with
     // MSVC2008/ARM in tst_endian -> use extra indirection to resolve size of T.
     const size_t size = sizeof(T);
-#if QT_HAS_BUILTIN(__builtin_memcpy)
+#if __has_builtin(__builtin_memcpy)
     __builtin_memcpy
 #else
     memcpy
@@ -78,7 +78,7 @@ template <typename T> Q_ALWAYS_INLINE T qFromUnaligned(const void *src)
 {
     T dest;
     const size_t size = sizeof(T);
-#if QT_HAS_BUILTIN(__builtin_memcpy)
+#if __has_builtin(__builtin_memcpy)
     __builtin_memcpy
 #else
     memcpy