build: Split hardening/fPIE options out

This allows for fPIE to be used selectively.

configure.ac

@@ -326,6 +326,7 @@ case $host in
 
      AX_CHECK_LINK_FLAG([[-Wl,-headerpad_max_install_names]], [LDFLAGS="$LDFLAGS -Wl,-headerpad_max_install_names"])
      CPPFLAGS="$CPPFLAGS -DMAC_OSX"
+     OBJCXXFLAGS="$CXXFLAGS"
      ;;
    *linux*)
      TARGET_OS=linux
@@ -424,6 +425,11 @@ if test x$use_glibc_compat != xno; then
 
 fi
 
+if test x$TARGET_OS != xwindows; then
+  # All windows code is PIC, forcing it on just adds useless compile warnings
+  AX_CHECK_COMPILE_FLAG([-fPIC],[PIC_FLAGS="-fPIC"])
+fi
+
 if test x$use_hardening != xno; then
   AX_CHECK_COMPILE_FLAG([-Wstack-protector],[HARDENED_CXXFLAGS="$HARDENED_CXXFLAGS -Wstack-protector"])
   AX_CHECK_COMPILE_FLAG([-fstack-protector-all],[HARDENED_CXXFLAGS="$HARDENED_CXXFLAGS -fstack-protector-all"])
@@ -441,8 +447,7 @@ if test x$use_hardening != xno; then
   AX_CHECK_LINK_FLAG([[-Wl,-z,now]], [HARDENED_LDFLAGS="$HARDENED_LDFLAGS -Wl,-z,now"])
 
   if test x$TARGET_OS != xwindows; then
-    # All windows code is PIC, forcing it on just adds useless compile warnings
-    AX_CHECK_COMPILE_FLAG([-fPIE],[HARDENED_CXXFLAGS="$HARDENED_CXXFLAGS -fPIE"])
+    AX_CHECK_COMPILE_FLAG([-fPIE],[PIE_FLAGS="-fPIE"])
     AX_CHECK_LINK_FLAG([[-pie]], [HARDENED_LDFLAGS="$HARDENED_LDFLAGS -pie"])
   fi
 
@@ -451,11 +456,6 @@ if test x$use_hardening != xno; then
        AC_CHECK_LIB([ssp],      [main],, AC_MSG_ERROR(lib missing))
     ;;
   esac
-
-  CXXFLAGS="$CXXFLAGS $HARDENED_CXXFLAGS"
-  CPPFLAGS="$CPPFLAGS $HARDENED_CPPFLAGS"
-  LDFLAGS="$LDFLAGS $HARDENED_LDFLAGS"
-  OBJCXXFLAGS="$CXXFLAGS"
 fi
 
 dnl this flag screws up non-darwin gcc even when the check fails. special-case it.
@@ -915,6 +915,11 @@ AC_SUBST(CLIENT_VERSION_IS_RELEASE, _CLIENT_VERSION_IS_RELEASE)
 AC_SUBST(COPYRIGHT_YEAR, _COPYRIGHT_YEAR)
 
 AC_SUBST(RELDFLAGS)
+AC_SUBST(HARDENED_CXXFLAGS)
+AC_SUBST(HARDENED_CPPFLAGS)
+AC_SUBST(HARDENED_LDFLAGS)
+AC_SUBST(PIC_FLAGS)
+AC_SUBST(PIE_FLAGS)
 AC_SUBST(LIBTOOL_APP_LDFLAGS)
 AC_SUBST(USE_UPNP)
 AC_SUBST(USE_QRCODE)