diff options
| author | Tor Arne Vestbø <tor.arne.vestbo@qt.io> | 2019-12-08 23:47:10 +0100 |
|---|---|---|
| committer | Tor Arne Vestbø <tor.arne.vestbo@qt.io> | 2019-12-10 00:48:07 +0100 |
| commit | c3bd5ffdc8a3b459f18ba6e35fca93e29f3b0ab0 (patch) | |
| tree | 24d4c1350b6a08d35396377e83301bda3b4addb4 /src/corelib/tools | |
| parent | 191ac31598ccc9d7c8a2c83730755714f903b7ca (diff) | |
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>
Diffstat (limited to 'src/corelib/tools')
| -rw-r--r-- | src/corelib/tools/qalgorithms.h | 4 | ||||
| -rw-r--r-- | src/corelib/tools/qscopeguard.h | 4 |
2 files changed, 4 insertions, 4 deletions
diff --git a/src/corelib/tools/qalgorithms.h b/src/corelib/tools/qalgorithms.h index b01ce0db58..aa79e0d4a9 100644 --- a/src/corelib/tools/qalgorithms.h +++ b/src/corelib/tools/qalgorithms.h @@ -535,7 +535,7 @@ QT_DEPRECATED_X("Use std::binary_search") Q_OUTOFLINE_TEMPLATE RandomAccessItera # define QT_HAS_BUILTIN_CTZS Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_ctzs(quint16 v) noexcept { -# if QT_HAS_BUILTIN(__builtin_ctzs) +# if __has_builtin(__builtin_ctzs) return __builtin_ctzs(v); # else return __builtin_ctz(v); @@ -544,7 +544,7 @@ Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_ctzs(quint16 v) noexcept #define QT_HAS_BUILTIN_CLZS Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_clzs(quint16 v) noexcept { -# if QT_HAS_BUILTIN(__builtin_clzs) +# if __has_builtin(__builtin_clzs) return __builtin_clzs(v); # else return __builtin_clz(v) - 16U; diff --git a/src/corelib/tools/qscopeguard.h b/src/corelib/tools/qscopeguard.h index 45c3f93da4..40d2747b1d 100644 --- a/src/corelib/tools/qscopeguard.h +++ b/src/corelib/tools/qscopeguard.h @@ -51,7 +51,7 @@ template <typename F> QScopeGuard<F> qScopeGuard(F f); template <typename F> class -#if QT_HAS_CPP_ATTRIBUTE(nodiscard) +#if __has_cpp_attribute(nodiscard) // Q_REQUIRED_RESULT can be defined as __warn_unused_result__ or as [[nodiscard]] // but the 1st one has some limitations for example can be placed only on functions. Q_REQUIRED_RESULT @@ -91,7 +91,7 @@ private: template <typename F> -#if QT_HAS_CPP_ATTRIBUTE(nodiscard) +#if __has_cpp_attribute(nodiscard) Q_REQUIRED_RESULT #endif QScopeGuard<F> qScopeGuard(F f) |