[libvirt] [PATCHv2] build: prefer -fstack-protector-strong to -all

Try -fstack-protector-strong first on Linux. If that fails, fall back to -fstack-protector-all. --- m4/virt-compile-warnings.m4 | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) diff --git a/m4/virt-compile-warnings.m4 b/m4/virt-compile-warnings.m4 index 196afa7..532a777 100644 --- a/m4/virt-compile-warnings.m4 +++ b/m4/virt-compile-warnings.m4 @@ -164,13 +164,14 @@ AC_DEFUN([LIBVIRT_COMPILE_WARNINGS],[ dnl "error: -fstack-protector not supported for this target [-Werror]" ;; *-*-linux*) - dnl Fedora only uses -fstack-protector, but doesn't seem to - dnl be great overhead in adding -fstack-protector-all instead + dnl Prefer -fstack-protector-strong if it's available. + dnl There doesn't seem to be great overhead in adding + dnl -fstack-protector-all instead of -fstack-protector. dnl - dnl We also don't need ssp-buffer-size with -all, + dnl We also don't need ssp-buffer-size with -all or -strong, dnl since functions are protected regardless of buffer size. dnl wantwarn="$wantwarn --param=ssp-buffer-size=4" - wantwarn="$wantwarn -fstack-protector-all" + wantwarn="$wantwarn -fstack-protector-strong" ;; *-*-freebsd*) dnl FreeBSD ships old gcc 4.2.1 which doesn't handle @@ -201,6 +202,19 @@ AC_DEFUN([LIBVIRT_COMPILE_WARNINGS],[ gl_WARN_ADD([$w]) done + case $host in + *-*-linux*) + dnl Fall back to -fstack-protector-all if -strong is not available + case $WARN_CFLAGS in + *-fstack-protector-strong*) + ;; + *) + gl_WARN_ADD(["-fstack-protector-all"]) + ;; + esac + ;; + esac + # Silence certain warnings in gnulib, and use improved glibc headers AC_DEFINE([lint], [1], [Define to 1 if the compiler is checking for lint.]) -- 1.8.5.5