From: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Date: Fri, 11 Jan 2013 15:03:04 +0000 (-0500)
Subject: build-sys: use _FORTIFY_SOURCE only if optimizing
X-Git-Tag: v198~569
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=6a17986542912ed80d9fdc1b6eaa6d48fdd5d02d

build-sys: use _FORTIFY_SOURCE only if optimizing

Rather then force the user to undefine _FORTIFY_SOURCE,
don't define it in the first place if it cannot be used.

I'm assuming that -O* can only be sensibly specified in $CFLAGS.
---

diff --git a/autogen.sh b/autogen.sh
index 33d8fcda2..86fe9b378 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -54,7 +54,7 @@ args="$args \
 fi
 
 if [ "x$1" = "xc" ]; then
-        ./configure CFLAGS='-g -O0 -Wp,-U_FORTIFY_SOURCE' $args
+        ./configure CFLAGS='-g -O0' $args
         make clean
 else
         echo
@@ -62,6 +62,6 @@ else
         echo "Initialized build system. For a common configuration please run:"
         echo "----------------------------------------------------------------"
         echo
-        echo "./configure CFLAGS='-g -O0 -Wp,-U_FORTIFY_SOURCE' $args"
+        echo "./configure CFLAGS='-g -O0' $args"
         echo
 fi
diff --git a/configure.ac b/configure.ac
index 7a3cd8751..3566dac83 100644
--- a/configure.ac
+++ b/configure.ac
@@ -167,8 +167,10 @@ CC_CHECK_FLAGS_APPEND([with_cflags], [CFLAGS], [\
         --param=ssp-buffer-size=4])
 AC_SUBST([OUR_CFLAGS], $with_cflags)
 
-CC_CHECK_FLAGS_APPEND([with_cppflags], [CPPFLAGS], [\
-        -Wp,-D_FORTIFY_SOURCE=2])
+AS_CASE([$CFLAGS], [*-O[[12345\ ]]*], [
+        CC_CHECK_FLAGS_APPEND([with_cppflags], [CPPFLAGS], [\
+               -Wp,-D_FORTIFY_SOURCE=2])], [
+        AC_MSG_RESULT([skipping -D_FORTIFY_SOURCE, optimization not enabled])])
 AC_SUBST([OUR_CPPFLAGS], $with_cppflags)
 
 CC_CHECK_FLAGS_APPEND([with_ldflags], [LDFLAGS], [\