diff options
Diffstat (limited to 'libstdc++-v3/acinclude.m4')
| -rw-r--r-- | libstdc++-v3/acinclude.m4 | 42 |
1 files changed, 39 insertions, 3 deletions
diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4 index e668d2d..a0094c2 100644 --- a/libstdc++-v3/acinclude.m4 +++ b/libstdc++-v3/acinclude.m4 @@ -4023,10 +4023,11 @@ AC_DEFUN([GLIBCXX_ENABLE_LOCK_POLICY], [ dnl Why don't we check 8-byte CAS for sparc64, where _Atomic_word is long?! dnl New targets should only check for CAS for the _Atomic_word type. AC_TRY_COMPILE([ - #if defined __riscv + #if defined __AMDGCN__ || defined __nvptx__ + /* Yes, please. */ + #elif defined __riscv # error "Defaulting to mutex-based locks for ABI compatibility" - #endif - #if ! defined __GCC_HAVE_SYNC_COMPARE_AND_SWAP_2 + #elif ! defined __GCC_HAVE_SYNC_COMPARE_AND_SWAP_2 # error "No 2-byte compare-and-swap" #elif ! defined __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 # error "No 4-byte compare-and-swap" @@ -5745,6 +5746,41 @@ AC_DEFUN([GLIBCXX_ZONEINFO_DIR], [ ]) dnl +dnl Check for a tm_zone member in struct tm. +dnl +dnl This member is defined as const char* in Glibc, newlib, POSIX.1-2024, +dnl and as char* in BSD (including macOS). +dnl +dnl Defines: +dnl _GLIBCXX_USE_STRUCT_TM_TM_ZONE if struct tm has a tm_zone member. +dnl +AC_DEFUN([GLIBCXX_STRUCT_TM_TM_ZONE], [ + + AC_LANG_SAVE + AC_LANG_CPLUSPLUS + ac_save_CXXFLAGS="$CXXFLAGS" + CXXFLAGS="$CXXFLAGS -std=c++20" + + AC_CACHE_CHECK([for tm_zone member of struct tm], glibcxx_cv_tm_zone, [ + AC_COMPILE_IFELSE([AC_LANG_PROGRAM([#include <time.h> + ], + [struct tm t{}; t.tm_zone = (char*)0;] + )], + [glibcxx_cv_tm_zone=yes], + [glibcxx_cv_tm_zone=no] + ) + ]) + + if test $glibcxx_cv_tm_zone = yes; then + AC_DEFINE(_GLIBCXX_USE_STRUCT_TM_TM_ZONE, 1, + [Define if struct tm has a tm_zone member.]) + fi + + CXXFLAGS="$ac_save_CXXFLAGS" + AC_LANG_RESTORE +]) + +dnl dnl Check whether lock tables can be aligned to avoid false sharing. dnl dnl Defines: |