From: Nicholas Clark <nick@ccl4.org>
Date: Thu, 20 Dec 2007 16:02:25 +0000 (+0000)
Subject: A new try at getting -fstack-protector working, by adding it to the
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=6682be1cb0cf57e58661289c111831ff65f51b05;p=p5sagit%2Fp5-mst-13.2.git

A new try at getting -fstack-protector working, by adding it to the
gcc link flags so that any implementation dependant libraries are also
linked in.

p4raw-id: //depot/perl@32669
---

diff --git a/Configure b/Configure
index cd04dae..7e88403 100755
--- a/Configure
+++ b/Configure
@@ -1328,7 +1328,7 @@ libswanted_uselargefiles=''
 : List of libraries we want.
 : If anyone needs extra -lxxx, put those in a hint file.
 libswanted="sfio socket bind inet nsl nm ndbm gdbm dbm db malloc dl dld ld sun"
-libswanted="$libswanted m crypt sec util c cposix posix ucb bsd BSD"
+libswanted="$libswanted m crypt sec util c cposix posix ucb bsd BSD ssp"
 : We probably want to search /usr/shlib before most other libraries.
 : This is only used by the lib/ExtUtils/MakeMaker.pm routine extliblist.
 glibpth=`echo " $glibpth " | sed -e 's! /usr/shlib ! !'`
@@ -5047,17 +5047,19 @@ esac
 
 : argument order is deliberate, as the flag will start with - which set could
 : think is an option
-checkccflag='check=$1; flag=$2;
+checkccflag='check=$1; flag=$2; callback=$3;
 echo " ";
 echo "Checking if your compiler accepts $flag" 2>&1;
 echo "int main(void) { return 0; }" > gcctest.c;
-if $cc -O2 $flag -o gcctest gcctest.c; then
+if $cc -O2 $flag -o gcctest gcctest.c && ./gcctest; then
     echo "Yes, it does." 2>&1;
     case "$ccflags" in
     *$check*)
 	echo "Leaving current flags $ccflags alone." 2>&1
 	;;
-    *) dflt="$dflt $flag" ;;
+    *) dflt="$dflt $flag";
+	eval $callback
+	;;
     esac
 else
     echo "Nope, it does not, but that is ok." 2>&1;
@@ -5098,6 +5100,18 @@ default|recommended)
 		eval $checkccflag
 		;;
 	esac
+
+	# on x86_64 (at least) we require an extra library (libssp) in the
+	# link command line. This library is not named, so I infer that it is
+	# an implementation detail that may change. Hence the safest approach
+	# is to add the flag to the flags passed to the compiler at link time,
+	# as that way the compiler can do the right implementation dependant
+	# thing. (NWC)
+	case "$gccversion" in
+	?*)	set stack-protector -fstack-protector 'ldflags="$ldflags -fstack-protector"'
+		eval $checkccflag
+		;;
+	esac
 	;;
 esac
 
diff --git a/cflags.SH b/cflags.SH
index 5c355da..9dd6181 100755
--- a/cflags.SH
+++ b/cflags.SH
@@ -134,7 +134,7 @@ case "$gccversion" in
 '') ;;
 [12]*) ;; # gcc versions 1 (gasp!) and 2 are not good for this.
 Intel*) ;; # # Is that you, Intel C++?
-*)  for opt in -ansi -pedantic -std=c89 -W -Wextra -Wdeclaration-after-statement -Wendif-labels -Wc++-compat -fstack-protector
+*)  for opt in -ansi -pedantic -std=c89 -W -Wextra -Wdeclaration-after-statement -Wendif-labels -Wc++-compat
     do
        case " $ccflags " in
        *" $opt "*) ;; # Skip if already there.