From: Fabrice Fontaine Date: Fri, 17 Aug 2018 22:10:13 +0000 (+0200) Subject: toolchain: add BR2_TOOLCHAIN_SUPPORTS_ALWAYS_LOCKFREE_ATOMIC_INTS hidden option X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=5f6f910cc9978910ebab5e088cb7c3870371b382;p=buildroot.git toolchain: add BR2_TOOLCHAIN_SUPPORTS_ALWAYS_LOCKFREE_ATOMIC_INTS hidden option Add BR2_TOOLCHAIN_SUPPORTS_ALWAYS_LOCKFREE_ATOMIC_INTS variable and use it in BR2_TOOLCHAIN_HAS_GCC_BUG_64735. This new variable will be used to select boost atomic when lock-free atomic ints are not available Signed-off-by: Fabrice Fontaine Signed-off-by: Thomas Petazzoni --- diff --git a/toolchain/Config.in b/toolchain/Config.in index 3a53a32a6d..ad02af5215 100644 --- a/toolchain/Config.in +++ b/toolchain/Config.in @@ -69,18 +69,35 @@ comment "Toolchain Generic Options" config BR2_TOOLCHAIN_HAS_BINUTILS_BUG_19615 bool -# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64735 -# exception_ptr, nested_exception, and future from libstdc++ are not -# available for architectures not supporting always lock-free atomic -# ints before GCC 7 +# Atomic types can be: +# - never lock-free +# - sometimes lock-free +# - always lock-free +# see https://en.cppreference.com/w/c/atomic/ATOMIC_LOCK_FREE_consts +# +# On most architectures, gcc provides "always lock-free" atomic types, +# but a few architectures are limited to "sometimes lock-free" +# types. This hidden option allows to know if the architecture +# provides "always lock-free" atomic types. +config BR2_TOOLCHAIN_SUPPORTS_ALWAYS_LOCKFREE_ATOMIC_INTS + bool + default y + depends on !BR2_nios2 + depends on !BR2_ARM_CPU_ARMV4 + depends on !BR2_ARM_CPU_ARMV5 + depends on !BR2_sparc_v8 + depends on !BR2_m68k_cf5208 + +# Prior to gcc 7.x, exception_ptr, nested_exception and future from +# libstdc++ would only be provided on architectures that support +# always lock-free atomic ints. See +# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64735. This issue has +# been removed in GCC 7.x, where exception propagation is now +# supported without lock-free atomic int. config BR2_TOOLCHAIN_HAS_GCC_BUG_64735 bool - default y if BR2_nios2 - default y if BR2_ARM_CPU_ARMV4 - default y if BR2_ARM_CPU_ARMV5 - default y if BR2_sparc_v8 - default y if BR2_m68k_cf5208 - depends on !BR2_TOOLCHAIN_GCC_AT_LEAST_7 + default y if !BR2_TOOLCHAIN_SUPPORTS_ALWAYS_LOCKFREE_ATOMIC_INTS && \ + !BR2_TOOLCHAIN_GCC_AT_LEAST_7 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85180. This bug no # longer exists in gcc 8.x.