Fix copied from libvirt, commit by Eric Blake.
glibc 2.15 (on Fedora 17) coupled with explicit disabling of
optimization during development dies a painful death:
/usr/include/features.h:314:4: error: #warning _FORTIFY_SOURCE requires compiling with optimization (-O) [-Werror=cpp]
Work around this by only conditionally defining _FORTIFY_SOURCE,
in the case where glibc can actually use it. The trick is using
AH_VERBATIM instead of AC_DEFINE.
---
acinclude.m4 | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/acinclude.m4 b/acinclude.m4
index 73b5a7b..0c308bc 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -19,7 +19,7 @@ AC_DEFUN([VIRT_VIEWER_COMPILE_WARNINGS],[
warnCFLAGS=
- try_compiler_flags="-Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -fasynchronous-unwind-tables"
+ try_compiler_flags="-fexceptions -fstack-protector --param=ssp-buffer-size=4 -fasynchronous-unwind-tables"
case "$enable_compile_warnings" in
no)
@@ -44,6 +44,13 @@ AC_DEFUN([VIRT_VIEWER_COMPILE_WARNINGS],[
;;
esac
+ AH_VERBATIM([FORTIFY_SOURCE],
+ [/* Enable compile-time and run-time bounds-checking, and some warnings. */
+ #if defined __OPTIMIZE__ && __OPTIMIZE__
+ # define _FORTIFY_SOURCE 2
+ #endif
+ ])
+
compiler_flags=
for option in $try_compiler_flags; do
SAVE_CFLAGS="$CFLAGS"
--
1.7.10.4
