about summary refs log tree commit diff
path: root/m4
diff options
context:
space:
mode:
Diffstat (limited to 'm4')
-rw-r--r--m4/check-hardening-options.m4109
-rw-r--r--m4/check-libc.m4169
-rw-r--r--m4/check-os-options.m4142
-rw-r--r--m4/disable-compiler-warnings.m429
4 files changed, 449 insertions, 0 deletions
diff --git a/m4/check-hardening-options.m4 b/m4/check-hardening-options.m4
new file mode 100644
index 0000000..3ffdb1a
--- /dev/null
+++ b/m4/check-hardening-options.m4
@@ -0,0 +1,109 @@
+
+AC_DEFUN([CHECK_CFLAG], [
+	 AC_LANG_ASSERT(C)
+	 AC_MSG_CHECKING([if $saved_CC supports "$1"])
+	 old_cflags="$CFLAGS"
+	 CFLAGS="$1 -Wall -Werror"
+	 AC_TRY_LINK([
+		      #include <stdio.h>
+		      ],
+		     [printf("Hello")],
+		     AC_MSG_RESULT([yes])
+		     CFLAGS=$old_cflags
+		     HARDEN_CFLAGS="$HARDEN_CFLAGS $1",
+		     AC_MSG_RESULT([no])
+		     CFLAGS=$old_cflags
+		     [$2])
+])
+
+AC_DEFUN([CHECK_LDFLAG], [
+	 AC_LANG_ASSERT(C)
+	 AC_MSG_CHECKING([if $saved_LD supports "$1"])
+	 old_ldflags="$LDFLAGS"
+	 LDFLAGS="$1 -Wall -Werror"
+	 AC_TRY_LINK([
+		      #include <stdio.h>
+		      ],
+		     [printf("Hello")],
+		     AC_MSG_RESULT([yes])
+		     LDFLAGS=$old_ldflags
+		     HARDEN_LDFLAGS="$HARDEN_LDFLAGS $1",
+		     AC_MSG_RESULT([no])
+		     LDFLAGS=$old_ldflags
+		     [$2])
+])
+
+AC_DEFUN([DISABLE_AS_EXECUTABLE_STACK], [
+	save_cflags="$CFLAGS"
+	CFLAGS=
+	AC_MSG_CHECKING([whether AS supports .note.GNU-stack])
+	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+	__asm__(".section .note.GNU-stack,\"\",@progbits");]])],
+		[AC_MSG_RESULT([yes])]
+		[AM_CFLAGS=-DHAVE_GNU_STACK],
+		[AC_MSG_RESULT([no])]
+	)
+	CFLAGS="$save_cflags $AM_CFLAGS"
+])
+
+
+AC_DEFUN([CHECK_C_HARDENING_OPTIONS], [
+
+	AC_ARG_ENABLE([hardening],
+		[AS_HELP_STRING([--disable-hardening],
+				[Disable options to frustrate memory corruption exploits])],
+		[], [enable_hardening=yes])
+
+	AC_ARG_ENABLE([windows-ssp],
+		[AS_HELP_STRING([--enable-windows-ssp],
+				[Enable building the stack smashing protection on
+				 Windows. This currently distributing libssp-0.dll.])])
+
+	# We want to check for compiler flag support. Prior to clang v5.1, there was no
+	# way to make clang's "argument unused" warning fatal.  So we invoke the
+	# compiler through a wrapper script that greps for this message.
+	saved_CC="$CC"
+	saved_LD="$LD"
+	flag_wrap="$srcdir/scripts/wrap-compiler-for-flag-check"
+	CC="$flag_wrap $CC"
+	LD="$flag_wrap $LD"
+
+	AS_IF([test "x$enable_hardening" = "xyes"], [
+		# Tell GCC to NOT optimize based on signed arithmetic overflow
+		CHECK_CFLAG([[-fno-strict-overflow]])
+
+		# _FORTIFY_SOURCE replaces builtin functions with safer versions.
+		CHECK_CFLAG([[-D_FORTIFY_SOURCE=2]])
+
+		# Enable read only relocations
+		CHECK_LDFLAG([[-Wl,-z,relro]])
+		CHECK_LDFLAG([[-Wl,-z,now]])
+
+		# Windows security flags
+		AS_IF([test "x$HOST_OS" = "xwin"], [
+			CHECK_LDFLAG([[-Wl,--nxcompat]])
+			CHECK_LDFLAG([[-Wl,--dynamicbase]])
+			CHECK_LDFLAG([[-Wl,--high-entropy-va]])
+		])
+
+		# Use stack-protector-strong if available; if not, fallback to
+		# stack-protector-all which is considered to be overkill
+		AS_IF([test "x$enable_windows_ssp" = "xyes" -o "x$HOST_OS" != "xwin"], [
+			CHECK_CFLAG([[-fstack-protector-strong]],
+				CHECK_CFLAG([[-fstack-protector-all]],
+					AC_MSG_WARN([compiler does not appear to support stack protection])
+				)
+			)
+			AS_IF([test "x$HOST_OS" = "xwin"], [
+				AC_SEARCH_LIBS([__stack_chk_guard],[ssp])
+			])
+		])
+	])
+
+	# Restore CC, LD
+	CC="$saved_CC"
+	LD="$saved_LD"
+
+	CFLAGS="$CFLAGS $HARDEN_CFLAGS"
+	LDFLAGS="$LDFLAGS $HARDEN_LDFLAGS"
+])
diff --git a/m4/check-libc.m4 b/m4/check-libc.m4
new file mode 100644
index 0000000..e511f6d
--- /dev/null
+++ b/m4/check-libc.m4
@@ -0,0 +1,169 @@
+AC_DEFUN([CHECK_LIBC_COMPAT], [
+# Check for libc headers
+AC_CHECK_HEADERS([err.h readpassphrase.h])
+# Check for general libc functions
+AC_CHECK_FUNCS([asprintf freezero memmem])
+AC_CHECK_FUNCS([readpassphrase reallocarray recallocarray])
+AC_CHECK_FUNCS([strlcat strlcpy strndup strnlen strsep strtonum])
+AC_CHECK_FUNCS([timegm _mkgmtime timespecsub])
+AC_CHECK_FUNCS([getprogname syslog syslog_r])
+AC_CACHE_CHECK([for getpagesize], ac_cv_func_getpagesize, [
+	AC_LINK_IFELSE([AC_LANG_PROGRAM([[
+// Since Android NDK v16 getpagesize is defined as inline inside unistd.h
+#ifdef __ANDROID__
+#	include <unistd.h>
+#endif
+		]], [[
+	getpagesize();
+]])],
+	[ ac_cv_func_getpagesize="yes" ],
+	[ ac_cv_func_getpagesize="no"
+	])
+])
+AM_CONDITIONAL([HAVE_ASPRINTF], [test "x$ac_cv_func_asprintf" = xyes])
+AM_CONDITIONAL([HAVE_FREEZERO], [test "x$ac_cv_func_freezero" = xyes])
+AM_CONDITIONAL([HAVE_GETPAGESIZE], [test "x$ac_cv_func_getpagesize" = xyes])
+AM_CONDITIONAL([HAVE_MEMMEM], [test "x$ac_cv_func_memmem" = xyes])
+AM_CONDITIONAL([HAVE_READPASSPHRASE], [test "x$ac_cv_func_readpassphrase" = xyes])
+AM_CONDITIONAL([HAVE_REALLOCARRAY], [test "x$ac_cv_func_reallocarray" = xyes])
+AM_CONDITIONAL([HAVE_RECALLOCARRAY], [test "x$ac_cv_func_recallocarray" = xyes])
+AM_CONDITIONAL([HAVE_STRLCAT], [test "x$ac_cv_func_strlcat" = xyes])
+AM_CONDITIONAL([HAVE_STRLCPY], [test "x$ac_cv_func_strlcpy" = xyes])
+AM_CONDITIONAL([HAVE_STRNDUP], [test "x$ac_cv_func_strndup" = xyes])
+AM_CONDITIONAL([HAVE_STRNLEN], [test "x$ac_cv_func_strnlen" = xyes])
+AM_CONDITIONAL([HAVE_STRSEP], [test "x$ac_cv_func_strsep" = xyes])
+AM_CONDITIONAL([HAVE_STRTONUM], [test "x$ac_cv_func_strtonum" = xyes])
+AM_CONDITIONAL([HAVE_TIMEGM], [test "x$ac_cv_func_timegm" = xyes])
+AM_CONDITIONAL([HAVE_GETPROGNAME], [test "x$ac_cv_func_getprogname" = xyes])
+AM_CONDITIONAL([HAVE_SYSLOG], [test "x$ac_cv_func_syslog" = xyes])
+AM_CONDITIONAL([HAVE_SYSLOG_R], [test "x$ac_cv_func_syslog_r" = xyes])
+])
+
+AC_DEFUN([CHECK_SYSCALL_COMPAT], [
+AC_CHECK_FUNCS([accept4 pipe2 pledge poll socketpair])
+AM_CONDITIONAL([HAVE_ACCEPT4], [test "x$ac_cv_func_accept4" = xyes])
+AM_CONDITIONAL([HAVE_PIPE2], [test "x$ac_cv_func_pipe2" = xyes])
+AM_CONDITIONAL([HAVE_PLEDGE], [test "x$ac_cv_func_pledge" = xyes])
+AM_CONDITIONAL([HAVE_POLL], [test "x$ac_cv_func_poll" = xyes])
+AM_CONDITIONAL([HAVE_SOCKETPAIR], [test "x$ac_cv_func_socketpair" = xyes])
+])
+
+AC_DEFUN([CHECK_B64_NTOP], [
+AC_SEARCH_LIBS([b64_ntop],[resolv])
+AC_SEARCH_LIBS([__b64_ntop],[resolv])
+AC_CACHE_CHECK([for b64_ntop], ac_cv_have_b64_ntop_arg, [
+	AC_LINK_IFELSE([AC_LANG_PROGRAM([[
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <resolv.h>
+		]], [[ b64_ntop(NULL, 0, NULL, 0); ]])],
+	[ ac_cv_have_b64_ntop_arg="yes" ],
+	[ ac_cv_have_b64_ntop_arg="no"
+	])
+])
+AM_CONDITIONAL([HAVE_B64_NTOP], [test "x$ac_cv_func_b64_ntop_arg" = xyes])
+])
+
+AC_DEFUN([CHECK_CRYPTO_COMPAT], [
+# Check crypto-related libc functions and syscalls
+AC_CHECK_FUNCS([arc4random arc4random_buf arc4random_uniform])
+AC_CHECK_FUNCS([explicit_bzero getauxval])
+
+AC_CACHE_CHECK([for getentropy], ac_cv_func_getentropy, [
+	AC_LINK_IFELSE([AC_LANG_PROGRAM([[
+#include <sys/types.h>
+#include <unistd.h>
+
+/*
+ * Explanation:
+ *
+ *   - iOS <= 10.1 fails because of missing sys/random.h
+ *
+ *   - in macOS 10.12 getentropy is not tagged as introduced in
+ *     10.12 so we cannot use it for target < 10.12
+ */
+#ifdef __APPLE__
+#  include <AvailabilityMacros.h>
+#  include <TargetConditionals.h>
+
+# if (TARGET_OS_IPHONE || TARGET_OS_SIMULATOR)
+#  include <sys/random.h> /* Not available as of iOS <= 10.1 */
+# else
+
+#  include <sys/random.h> /* Pre 10.12 systems should die here */
+
+/* Based on: https://gitweb.torproject.org/tor.git/commit/?id=16fcbd21 */
+#  ifndef MAC_OS_X_VERSION_10_12
+#    define MAC_OS_X_VERSION_10_12 101200 /* Robustness */
+#  endif
+#  if defined(MAC_OS_X_VERSION_MIN_REQUIRED)
+#    if MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_12
+#      error "Targeting on Mac OSX 10.11 or earlier"
+#    endif
+#  endif
+
+# endif
+#endif /* __APPLE__ */
+		]], [[
+	char buffer;
+	(void)getentropy(&buffer, sizeof (buffer));
+]])],
+	[ ac_cv_func_getentropy="yes" ],
+	[ ac_cv_func_getentropy="no"
+	])
+])
+
+AC_CHECK_FUNCS([timingsafe_bcmp timingsafe_memcmp])
+AM_CONDITIONAL([HAVE_ARC4RANDOM], [test "x$ac_cv_func_arc4random" = xyes])
+AM_CONDITIONAL([HAVE_ARC4RANDOM_BUF], [test "x$ac_cv_func_arc4random_buf" = xyes])
+AM_CONDITIONAL([HAVE_ARC4RANDOM_UNIFORM], [test "x$ac_cv_func_arc4random_uniform" = xyes])
+AM_CONDITIONAL([HAVE_EXPLICIT_BZERO], [test "x$ac_cv_func_explicit_bzero" = xyes])
+AM_CONDITIONAL([HAVE_GETENTROPY], [test "x$ac_cv_func_getentropy" = xyes])
+AM_CONDITIONAL([HAVE_TIMINGSAFE_BCMP], [test "x$ac_cv_func_timingsafe_bcmp" = xyes])
+AM_CONDITIONAL([HAVE_TIMINGSAFE_MEMCMP], [test "x$ac_cv_func_timingsafe_memcmp" = xyes])
+
+# Override arc4random_buf implementations with known issues
+AM_CONDITIONAL([HAVE_ARC4RANDOM_BUF],
+	[test "x$USE_BUILTIN_ARC4RANDOM" != xyes \
+	   -a "x$ac_cv_func_arc4random_buf" = xyes])
+
+# Check for getentropy fallback dependencies
+AC_CHECK_FUNCS([getauxval])
+AC_SEARCH_LIBS([dl_iterate_phdr],[dl])
+AC_CHECK_FUNCS([dl_iterate_phdr])
+
+AC_SEARCH_LIBS([pthread_once],[pthread])
+AC_SEARCH_LIBS([pthread_mutex_lock],[pthread])
+AC_SEARCH_LIBS([clock_gettime],[rt posix4])
+AC_CHECK_FUNCS([clock_gettime])
+AM_CONDITIONAL([HAVE_CLOCK_GETTIME], [test "x$ac_cv_func_clock_gettime" = xyes])
+])
+
+AC_DEFUN([CHECK_VA_COPY], [
+AC_CACHE_CHECK([whether va_copy exists], ac_cv_have_va_copy, [
+	AC_LINK_IFELSE([AC_LANG_PROGRAM([[
+#include <stdarg.h>
+va_list x,y;
+		]], [[ va_copy(x,y); ]])],
+	[ ac_cv_have_va_copy="yes" ],
+	[ ac_cv_have_va_copy="no"
+	])
+])
+if test "x$ac_cv_have_va_copy" = "xyes" ; then
+	AC_DEFINE([HAVE_VA_COPY], [1], [Define if va_copy exists])
+fi
+
+AC_CACHE_CHECK([whether __va_copy exists], ac_cv_have___va_copy, [
+	AC_LINK_IFELSE([AC_LANG_PROGRAM([[
+#include <stdarg.h>
+va_list x,y;
+		]], [[ __va_copy(x,y); ]])],
+	[ ac_cv_have___va_copy="yes" ], [ ac_cv_have___va_copy="no"
+	])
+])
+if test "x$ac_cv_have___va_copy" = "xyes" ; then
+	AC_DEFINE([HAVE___VA_COPY], [1], [Define if __va_copy exists])
+fi
+])
diff --git a/m4/check-os-options.m4 b/m4/check-os-options.m4
new file mode 100644
index 0000000..8241aee
--- /dev/null
+++ b/m4/check-os-options.m4
@@ -0,0 +1,142 @@
+AC_DEFUN([CHECK_OS_OPTIONS], [
+
+CFLAGS="$CFLAGS -Wall -std=gnu99 -fno-strict-aliasing"
+BUILD_NC=yes
+
+case $host_os in
+	*aix*)
+		HOST_OS=aix
+		if test "`echo $CC | cut -d ' ' -f 1`" != "gcc" ; then
+			CFLAGS="-qnoansialias $USER_CFLAGS"
+		fi
+		AC_SUBST([PLATFORM_LDADD], ['-lperfstat'])
+		;;
+	*cygwin*)
+		HOST_OS=cygwin
+		CPPFLAGS="$CPPFLAGS -D_GNU_SOURCE"
+		;;
+	*darwin*)
+		HOST_OS=darwin
+		HOST_ABI=macosx
+		#
+		# Don't use arc4random on systems before 10.12 because of
+		# weak seed on failure to open /dev/random, based on latest
+		# public source:
+		# http://www.opensource.apple.com/source/Libc/Libc-997.90.3/gen/FreeBSD/arc4random.c
+		#
+		# We use the presence of getentropy() to detect 10.12. The
+		# following check take into account that:
+ 		#
+		#   - iOS <= 10.1 fails because of missing getentropy and
+		#     hence they miss sys/random.h
+		#
+		#   - in macOS 10.12 getentropy is not tagged as introduced in
+		#     10.12 so we cannot use it for target < 10.12
+		#
+		AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+#include <AvailabilityMacros.h>
+#include <unistd.h>
+#include <sys/random.h>  /* Systems without getentropy() should die here */
+
+/* Based on: https://gitweb.torproject.org/tor.git/commit/?id=16fcbd21 */
+#ifndef MAC_OS_X_VERSION_10_12
+#  define MAC_OS_X_VERSION_10_12 101200
+#endif
+#if defined(MAC_OS_X_VERSION_MIN_REQUIRED)
+#  if MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_12
+#    error "Running on Mac OSX 10.11 or earlier"
+#  endif
+#endif
+                       ]], [[
+char buf[1]; getentropy(buf, 1);
+					   ]])],
+                       [ USE_BUILTIN_ARC4RANDOM=no ],
+                       [ USE_BUILTIN_ARC4RANDOM=yes ]
+		)
+		AC_MSG_CHECKING([whether to use builtin arc4random])
+		AC_MSG_RESULT([$USE_BUILTIN_ARC4RANDOM])
+		# Not available on iOS
+		AC_CHECK_HEADER([arpa/telnet.h], [], [BUILD_NC=no])
+		;;
+	*freebsd*)
+		HOST_OS=freebsd
+		HOST_ABI=elf
+		# fork detection missing, weak seed on failure
+		# https://svnweb.freebsd.org/base/head/lib/libc/gen/arc4random.c?revision=268642&view=markup
+		USE_BUILTIN_ARC4RANDOM=yes
+		AC_SUBST([PROG_LDADD], ['-lthr'])
+		;;
+	*hpux*)
+		HOST_OS=hpux;
+		if test "`echo $CC | cut -d ' ' -f 1`" = "gcc" ; then
+			CFLAGS="$CFLAGS -mlp64"
+		else
+			CFLAGS="-g -O2 +DD64 +Otype_safety=off $USER_CFLAGS"
+		fi
+		CPPFLAGS="$CPPFLAGS -D_XOPEN_SOURCE=600 -D__STRICT_ALIGNMENT"
+		;;
+	*linux*)
+		HOST_OS=linux
+		HOST_ABI=elf
+		CPPFLAGS="$CPPFLAGS -D_DEFAULT_SOURCE -D_BSD_SOURCE -D_POSIX_SOURCE -D_GNU_SOURCE"
+		;;
+	*midipix*)
+		HOST_OS=midipix
+		CPPFLAGS="$CPPFLAGS -D_DEFAULT_SOURCE -D_BSD_SOURCE -D_POSIX_SOURCE -D_GNU_SOURCE"
+		;;
+	*netbsd*)
+		HOST_OS=netbsd
+		HOST_ABI=elf
+		AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+#include <sys/param.h>
+#if __NetBSD_Version__ < 700000001
+        undefined
+#endif
+                       ]], [[]])],
+                       [ USE_BUILTIN_ARC4RANDOM=no ],
+                       [ USE_BUILTIN_ARC4RANDOM=yes ]
+		)
+		CPPFLAGS="$CPPFLAGS -D_OPENBSD_SOURCE"
+		;;
+	*openbsd* | *bitrig*)
+		HOST_OS=openbsd
+		HOST_ABI=elf
+		AC_DEFINE([HAVE_ATTRIBUTE__BOUNDED__], [1], [OpenBSD gcc has bounded])
+		AC_DEFINE([HAVE_ATTRIBUTE__DEAD], [1], [OpenBSD gcc has __dead])
+		;;
+	*mingw*)
+		HOST_OS=win
+		HOST_ABI=mingw64
+		BUILD_NC=no
+		CPPFLAGS="$CPPFLAGS -D_GNU_SOURCE -D_POSIX -D_POSIX_SOURCE -D__USE_MINGW_ANSI_STDIO"
+		CPPFLAGS="$CPPFLAGS -D_REENTRANT -D_POSIX_THREAD_SAFE_FUNCTIONS"
+		CPPFLAGS="$CPPFLAGS -DWIN32_LEAN_AND_MEAN -D_WIN32_WINNT=0x0600"
+		CPPFLAGS="$CPPFLAGS"
+		AC_SUBST([PLATFORM_LDADD], ['-lws2_32'])
+		;;
+	*solaris*)
+		HOST_OS=solaris
+		HOST_ABI=elf
+		CPPFLAGS="$CPPFLAGS -D__EXTENSIONS__ -D_XOPEN_SOURCE=600 -DBSD_COMP"
+		AC_SUBST([PLATFORM_LDADD], ['-ldl -lnsl -lsocket'])
+		;;
+	*) ;;
+esac
+
+AC_ARG_ENABLE([nc],
+	AS_HELP_STRING([--enable-nc], [Enable installing TLS-enabled nc(1)]))
+AM_CONDITIONAL([ENABLE_NC], [test "x$enable_nc" = xyes])
+AM_CONDITIONAL([BUILD_NC],  [test x$BUILD_NC = xyes -o "x$enable_nc" = xyes])
+
+AM_CONDITIONAL([HOST_AIX],     [test x$HOST_OS = xaix])
+AM_CONDITIONAL([HOST_CYGWIN],  [test x$HOST_OS = xcygwin])
+AM_CONDITIONAL([HOST_DARWIN],  [test x$HOST_OS = xdarwin])
+AM_CONDITIONAL([HOST_FREEBSD], [test x$HOST_OS = xfreebsd])
+AM_CONDITIONAL([HOST_HPUX],    [test x$HOST_OS = xhpux])
+AM_CONDITIONAL([HOST_LINUX],   [test x$HOST_OS = xlinux])
+AM_CONDITIONAL([HOST_MIDIPIX], [test x$HOST_OS = xmidipix])
+AM_CONDITIONAL([HOST_NETBSD],  [test x$HOST_OS = xnetbsd])
+AM_CONDITIONAL([HOST_OPENBSD], [test x$HOST_OS = xopenbsd])
+AM_CONDITIONAL([HOST_SOLARIS], [test x$HOST_OS = xsolaris])
+AM_CONDITIONAL([HOST_WIN],     [test x$HOST_OS = xwin])
+])
diff --git a/m4/disable-compiler-warnings.m4 b/m4/disable-compiler-warnings.m4
new file mode 100644
index 0000000..2792722
--- /dev/null
+++ b/m4/disable-compiler-warnings.m4
@@ -0,0 +1,29 @@
+AC_DEFUN([DISABLE_COMPILER_WARNINGS], [
+# Clang throws a lot of warnings when it does not understand a flag. Disable
+# this warning for now so other warnings are visible.
+AC_MSG_CHECKING([if compiling with clang])
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([], [[
+#ifndef __clang__
+	not clang
+#endif
+	]])],
+	[CLANG=yes],
+	[CLANG=no]
+)
+AC_MSG_RESULT([$CLANG])
+AS_IF([test "x$CLANG" = "xyes"], [CLANG_FLAGS=-Qunused-arguments])
+CFLAGS="$CFLAGS $CLANG_FLAGS"
+LDFLAGS="$LDFLAGS $CLANG_FLAGS"
+
+# Removing the dependency on -Wno-pointer-sign should be a goal. These are
+# largely unsigned char */char* mismatches in asn1 functions.
+save_cflags="$CFLAGS"
+CFLAGS=-Wno-pointer-sign
+AC_MSG_CHECKING([whether CC supports -Wno-pointer-sign])
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([])],
+	[AC_MSG_RESULT([yes])]
+	[AM_CFLAGS=-Wno-pointer-sign],
+	[AC_MSG_RESULT([no])]
+)
+CFLAGS="$save_cflags $AM_CFLAGS"
+])