configure.ac: fix build without stack-protector

Compiler based hardening (including -fstack-protector-strong) are
enabled since version 3.0.3 and
https://github.com/lxc/lxc/commit/2268c27754152aa538db2c9e3753d72d19bcd17a

However, some compilers could missed the needed library (-lssp or
-lssp_nonshared) at linking step so use ax_check_link_flag instead of
ax_check_compile_flag

Fixes:
 - http://autobuild.buildroot.org/results/0b90e7dca2984652842832a41abad93ac49a9b86

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>

diff --git a/configure.ac b/configure.ac
index 631e6070dd5f0708514ec6226c2c7ae9c9c20fe9..11c7fdc88b6b915f23f84e53ffd9df8474794eec 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -688,7 +688,7 @@ AX_CHECK_COMPILE_FLAG([-Wcast-align], [CFLAGS="$CFLAGS -Wcast-align"],,[-Werror]
 AX_CHECK_COMPILE_FLAG([-Wstrict-prototypes], [CFLAGS="$CFLAGS -Wstrict-prototypes"],,[-Werror])
 AX_CHECK_COMPILE_FLAG([-fno-strict-aliasing], [CFLAGS="$CFLAGS -fno-strict-aliasing"],,[-Werror])
 AX_CHECK_COMPILE_FLAG([-fstack-clash-protection], [CFLAGS="$CFLAGS -fstack-clash-protection"],,[-Werror])
-AX_CHECK_COMPILE_FLAG([-fstack-protector-strong], [CFLAGS="$CFLAGS -fstack-protector-strong"],,[-Werror])
+AX_CHECK_LINK_FLAG([-fstack-protector-strong], [CFLAGS="$CFLAGS -fstack-protector-strong"],,[-Werror])
 AX_CHECK_COMPILE_FLAG([-g], [CFLAGS="$CFLAGS -g"],,[-Werror])
 AX_CHECK_COMPILE_FLAG([--mcet -fcf-protection], [CFLAGS="$CFLAGS --mcet -fcf-protection"],,[-Werror])
 AX_CHECK_COMPILE_FLAG([-Werror=implicit-function-declaration], [CFLAGS="$CFLAGS -Werror=implicit-function-declaration"],,[-Werror])