diff options
Diffstat (limited to 'build-aux')
| -rw-r--r-- | build-aux/m4/l_atomic.m4 | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/build-aux/m4/l_atomic.m4 b/build-aux/m4/l_atomic.m4 new file mode 100644 index 0000000000..906724b640 --- /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 <atomic> + #include <cstdint> + + int main() { + std::atomic<int64_t> a{}; + + int64_t v = 5; + int64_t r = a.fetch_add(v); + return static_cast<int>(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 +]) |