From 428205712f3ebd4efb7b0ea71d9fa45e0b28fece Mon Sep 17 00:00:00 2001 From: "H. Vetinari" Date: Wed, 8 Feb 2023 16:44:15 +1100 Subject: [PATCH 4/4] Revert "[libc++] Remove workaround for C11 features on compilers that don't support using_if_exists" This reverts commit 21f73d5826fb5024a27eaacafadfa316f58949c5. --- libcxx/include/__config | 66 +++++++++++++++++++++++++++++++++++++++++ libcxx/include/cstdlib | 4 +-- libcxx/include/ctime | 18 +++++++++-- 3 files changed, 84 insertions(+), 4 deletions(-) diff --git a/libcxx/include/__config b/libcxx/include/__config index 9759d3b9e8e0..9a27abe3367b 100644 --- a/libcxx/include/__config +++ b/libcxx/include/__config @@ -556,6 +556,72 @@ # define _LIBCPP_NO_CFI # endif +// If the compiler supports using_if_exists, pretend we have those functions and they'll +// be picked up if the C library provides them. +// +// TODO: Once we drop support for Clang 12, we can assume the compiler supports using_if_exists +// for platforms that don't have a conforming C11 library, so we can drop this whole thing. +# if __has_attribute(using_if_exists) +# define _LIBCPP_HAS_TIMESPEC_GET +# define _LIBCPP_HAS_QUICK_EXIT +# define _LIBCPP_HAS_ALIGNED_ALLOC +# else +# if (defined(__ISO_C_VISIBLE) && (__ISO_C_VISIBLE >= 2011)) || __cplusplus >= 201103L +# if defined(__FreeBSD__) +# define _LIBCPP_HAS_ALIGNED_ALLOC +# define _LIBCPP_HAS_QUICK_EXIT +# if __FreeBSD_version >= 1300064 || \ + (__FreeBSD_version >= 1201504 && __FreeBSD_version < 1300000) +# define _LIBCPP_HAS_TIMESPEC_GET +# endif +# elif defined(__BIONIC__) +# if __ANDROID_API__ >= 21 +# define _LIBCPP_HAS_QUICK_EXIT +# endif +# if __ANDROID_API__ >= 28 +# define _LIBCPP_HAS_ALIGNED_ALLOC +# endif +# if __ANDROID_API__ >= 29 +# define _LIBCPP_HAS_TIMESPEC_GET +# endif +# elif defined(__Fuchsia__) || defined(__wasi__) || defined(__NetBSD__) +# define _LIBCPP_HAS_ALIGNED_ALLOC +# define _LIBCPP_HAS_QUICK_EXIT +# define _LIBCPP_HAS_TIMESPEC_GET +# elif defined(__OpenBSD__) +# define _LIBCPP_HAS_ALIGNED_ALLOC +# define _LIBCPP_HAS_TIMESPEC_GET +# elif defined(__linux__) +# if !defined(_LIBCPP_HAS_MUSL_LIBC) +# if _LIBCPP_GLIBC_PREREQ(2, 15) || defined(__BIONIC__) +# define _LIBCPP_HAS_QUICK_EXIT +# endif +# if _LIBCPP_GLIBC_PREREQ(2, 17) +# define _LIBCPP_HAS_ALIGNED_ALLOC +# define _LIBCPP_HAS_TIMESPEC_GET +# endif +# else // defined(_LIBCPP_HAS_MUSL_LIBC) +# define _LIBCPP_HAS_ALIGNED_ALLOC +# define _LIBCPP_HAS_QUICK_EXIT +# define _LIBCPP_HAS_TIMESPEC_GET +# endif +# elif defined(_LIBCPP_MSVCRT) + // Using Microsoft's C Runtime library, not MinGW +# define _LIBCPP_HAS_TIMESPEC_GET +# elif defined(__APPLE__) + // timespec_get and aligned_alloc were introduced in macOS 10.15 and + // aligned releases +# if ((defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ >= 101500) || \ + (defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ >= 130000) || \ + (defined(__ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__ >= 130000) || \ + (defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ >= 60000)) +# define _LIBCPP_HAS_ALIGNED_ALLOC +# define _LIBCPP_HAS_TIMESPEC_GET +# endif +# endif // __APPLE__ +# endif +# endif // __has_attribute(using_if_exists) + # ifndef _LIBCPP_CXX03_LANG # define _LIBCPP_ALIGNOF(_Tp) alignof(_Tp) diff --git a/libcxx/include/cstdlib b/libcxx/include/cstdlib index ab2c159c7259..44a6f6a5dc36 100644 --- a/libcxx/include/cstdlib +++ b/libcxx/include/cstdlib @@ -140,11 +140,11 @@ using ::mbtowc _LIBCPP_USING_IF_EXISTS; using ::wctomb _LIBCPP_USING_IF_EXISTS; using ::mbstowcs _LIBCPP_USING_IF_EXISTS; using ::wcstombs _LIBCPP_USING_IF_EXISTS; -#if !defined(_LIBCPP_CXX03_LANG) +#if !defined(_LIBCPP_CXX03_LANG) && defined(_LIBCPP_HAS_QUICK_EXIT) using ::at_quick_exit _LIBCPP_USING_IF_EXISTS; using ::quick_exit _LIBCPP_USING_IF_EXISTS; #endif -#if _LIBCPP_STD_VER >= 17 +#if _LIBCPP_STD_VER >= 17 && defined(_LIBCPP_HAS_ALIGNED_ALLOC) using ::aligned_alloc _LIBCPP_USING_IF_EXISTS; #endif diff --git a/libcxx/include/ctime b/libcxx/include/ctime index b61e19d6446d..6b48da7a7e4b 100644 --- a/libcxx/include/ctime +++ b/libcxx/include/ctime @@ -60,13 +60,27 @@ int timespec_get( struct timespec *ts, int base); // C++17 # pragma GCC system_header #endif +// FIXME: +// Apple SDKs don't define ::timespec_get unconditionally in C++ mode. This +// should be fixed in future SDKs, but for the time being we need to avoid +// trying to use that declaration when the SDK doesn't provide it. Note that +// we're detecting this here instead of in <__config> because we can't include +// system headers from <__config>, since it leads to circular module dependencies. +// This is also meant to be a very temporary workaround until the SDKs are fixed. +#if defined(__APPLE__) && !__has_attribute(using_if_exists) +# include +# if defined(_LIBCPP_HAS_TIMESPEC_GET) && (__DARWIN_C_LEVEL < __DARWIN_C_FULL) +# define _LIBCPP_HAS_TIMESPEC_GET_NOT_ACTUALLY_PROVIDED +# endif +#endif + _LIBCPP_BEGIN_NAMESPACE_STD using ::clock_t _LIBCPP_USING_IF_EXISTS; using ::size_t _LIBCPP_USING_IF_EXISTS; using ::time_t _LIBCPP_USING_IF_EXISTS; using ::tm _LIBCPP_USING_IF_EXISTS; -#if _LIBCPP_STD_VER >= 17 +#if _LIBCPP_STD_VER >= 17 && defined(_LIBCPP_HAS_TIMESPEC_GET) using ::timespec _LIBCPP_USING_IF_EXISTS; #endif using ::clock _LIBCPP_USING_IF_EXISTS; @@ -78,7 +92,7 @@ using ::ctime _LIBCPP_USING_IF_EXISTS; using ::gmtime _LIBCPP_USING_IF_EXISTS; using ::localtime _LIBCPP_USING_IF_EXISTS; using ::strftime _LIBCPP_USING_IF_EXISTS; -#if _LIBCPP_STD_VER >= 17 +#if _LIBCPP_STD_VER >= 17 && defined(_LIBCPP_HAS_TIMESPEC_GET) && !defined(_LIBCPP_HAS_TIMESPEC_GET_NOT_ACTUALLY_PROVIDED) using ::timespec_get _LIBCPP_USING_IF_EXISTS; #endif