git / moonbite-core / build-aux/m4/l_atomic.m4 · raw

dnl Copyright (c) 2015 Tim Kosse <tim.kosse@filezilla-project.org>dnl Copying and distribution of this file, with or without modification, arednl permitted in any medium without royalty provided the copyright noticednl and this notice are preserved. This file is offered as-is, without anydnl warranty.# Some versions of gcc/libstdc++ require linking with -latomic if# using the C++ atomic library.## Sourced from http://bugs.debian.org/797228m4_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 out how to use std::atomic])        ])    ])  AC_LANG_POP])