check if we need to link pthread dynamically

On Linux, bionic and musl for instance do not need libpthread. With
bionic, there is not even a stub library for compatibility.

2 files changed, 2 insertions, 3 deletions

diff --git a/m4/check-libc.m4 b/m4/check-libc.m4
index a4df0b7..85d253a 100644
--- a/m4/check-libc.m4
+++ b/m4/check-libc.m4
@@ -130,6 +130,7 @@ AC_CHECK_FUNCS([getauxval])
 AC_SEARCH_LIBS([dl_iterate_phdr],[dl])
 AC_CHECK_FUNCS([dl_iterate_phdr])
 
+AC_SEARCH_LIBS([pthread_once],[pthread])
 AC_SEARCH_LIBS([clock_gettime],[rt posix4])
 AC_CHECK_FUNCS([clock_gettime])
 AM_CONDITIONAL([HAVE_CLOCK_GETTIME], [test "x$ac_cv_func_clock_gettime" = xyes])
diff --git a/m4/check-os-options.m4 b/m4/check-os-options.m4
index 414e63d..9fc0faf 100644
--- a/m4/check-os-options.m4
+++ b/m4/check-os-options.m4
@@ -9,7 +9,7 @@ case $host_os in
                 if test "`echo $CC | cut -d ' ' -f 1`" != "gcc" ; then
                         CFLAGS="-qnoansialias $USER_CFLAGS"
                 fi
-                AC_SUBST([PLATFORM_LDADD], ['-lperfstat -lpthread'])
+                AC_SUBST([PLATFORM_LDADD], ['-lperfstat'])
                 ;;
         *cygwin*)
                 HOST_OS=cygwin
@@ -74,13 +74,11 @@ char buf[1]; getentropy(buf, 1);
                         CFLAGS="-g -O2 +DD64 +Otype_safety=off $USER_CFLAGS"
                 fi
                 CPPFLAGS="$CPPFLAGS -D_XOPEN_SOURCE=600 -D__STRICT_ALIGNMENT"
-                AC_SUBST([PLATFORM_LDADD], ['-lpthread'])
                 ;;
         *linux*)
                 HOST_OS=linux
                 HOST_ABI=elf
                 CPPFLAGS="$CPPFLAGS -D_DEFAULT_SOURCE -D_BSD_SOURCE -D_POSIX_SOURCE -D_GNU_SOURCE"
-                AC_SUBST([PLATFORM_LDADD], ['-lpthread'])
                 ;;
         *netbsd*)
                 HOST_OS=netbsd