From 147003c73edb5a949ca403ecf8883c1b8bfaa6c1 Mon Sep 17 00:00:00 2001 From: Anthony Towns Date: Tue, 23 Aug 2016 16:55:15 +1000 Subject: [PATCH] Add configure check for -latomic Github-Pull: #8563 Rebased-From: 878faacd7b3daac437cc689b13422f6432fb5cd0 --- build-aux/m4/l_atomic.m4 | 40 ++++++++++++++++++++++++++++++++++++++++ configure.ac | 3 +++ 2 files changed, 43 insertions(+) create mode 100644 build-aux/m4/l_atomic.m4 diff --git a/build-aux/m4/l_atomic.m4 b/build-aux/m4/l_atomic.m4 new file mode 100644 index 000000000..906724b64 --- /dev/null +++ b/build-aux/m4/l_atomic.m4 @@ -0,0 +1,40 @@ +# Some versions of gcc/libstdc++ require linking with -latomic if +# using the C++ atomic library. +# +# Sourced from http://bugs.debian.org/797228 + +m4_define([_CHECK_ATOMIC_testbody], [[ + #include + #include + + int main() { + std::atomic a{}; + + int64_t v = 5; + int64_t r = a.fetch_add(v); + return static_cast(r); + } +]]) + +AC_DEFUN([CHECK_ATOMIC], [ + + AC_LANG_PUSH(C++) + + AC_MSG_CHECKING([whether std::atomic can be used without link library]) + + AC_LINK_IFELSE([AC_LANG_SOURCE([_CHECK_ATOMIC_testbody])],[ + AC_MSG_RESULT([yes]) + ],[ + AC_MSG_RESULT([no]) + LIBS="$LIBS -latomic" + AC_MSG_CHECKING([whether std::atomic needs -latomic]) + AC_LINK_IFELSE([AC_LANG_SOURCE([_CHECK_ATOMIC_testbody])],[ + AC_MSG_RESULT([yes]) + ],[ + AC_MSG_RESULT([no]) + AC_MSG_FAILURE([cannot figure our how to use std::atomic]) + ]) + ]) + + AC_LANG_POP +]) diff --git a/configure.ac b/configure.ac index 7b66b61eb..55578c886 100644 --- a/configure.ac +++ b/configure.ac @@ -57,6 +57,9 @@ case $host in esac dnl Require C++11 compiler (no GNU extensions) AX_CXX_COMPILE_STDCXX([11], [noext], [mandatory]) +dnl Check if -latomic is required for +CHECK_ATOMIC + dnl Libtool init checks. LT_INIT([pic-only])