Fix Configure's csym test for gcc's link time optimisation

This introduces a volatile into the test program so gcc cannot optimise
out the symbol itself as being unused.

1 files changed, 8 insertions, 8 deletions

diff --git a/Configure b/Configure
index 74450a95e6..d4c95a7005 100755
--- a/Configure
+++ b/Configure
@@ -28,7 +28,7 @@
 # See Porting/pumpkin.pod for more information on metaconfig.
 #
 
-# Generated on Sun Jul 31 12:11:29 CEST 2011 [metaconfig 3.5 PL0]
+# Generated on Mon Aug 22 15:14:53 CEST 2011 [metaconfig 3.5 PL0]
 # (with additional metaconfig patches by perlbug@perl.org)
 
 cat >c1$$ <<EOF
@@ -1310,6 +1310,9 @@ fi
 
 groupstype=''
 i_whoami=''
+: Trailing extension.  Override this in a hint file, if needed.
+: Extra object files, if any, needed on this platform.
+archobjs=''
 archname=''
 : Possible local include directories to search.
 : Set locincpth to "" in a hint file to defeat local include searches.
@@ -1323,11 +1326,6 @@ inclwanted=''
 EBUGGING=''
 DEBUGGING=''
 
-: set usethreads on the Configure command line to enable threads.
-usereentrant='undef'
-: Trailing extension.  Override this in a hint file, if needed.
-: Extra object files, if any, needed on this platform.
-archobjs=''
 libnames=''
 : change the next line if compiling for Xenix/286 on Xenix/386
 xlibpth='/usr/lib/386 /lib/386'
@@ -1351,6 +1349,8 @@ plibpth=''
 libswanted=''
 : some systems want to use only the non-versioned libso:s
 ignore_versioned_solibs=''
+: set usethreads on the Configure command line to enable threads.
+usereentrant='undef'
 : full support for void wanted by default
 defvoidused=15
 
@@ -7774,13 +7774,13 @@ yes)
 		if $contains $tlook $tf >/dev/null 2>&1; then
 			tval=true;
 		elif $test "$mistrustnm" = compile -o "$mistrustnm" = run; then
-			echo "$extern_C void *$1$tdc; void *(*(p()))$tdc { return &$1; } int main() { if(p()) return(0); else return(1); }"> try.c;
+			echo "volatile int dummy = 0; $extern_C void *$1$tdc; void *(*(p()))$tdc { return dummy + &$1; } int main() { if(p()) return(0); else return(1); }"> try.c;
 			$cc -o try $optimize $ccflags $ldflags try.c >/dev/null 2>&1 $libs && tval=true;
 			$test "$mistrustnm" = run -a -x try && { $run ./try$_exe >/dev/null 2>&1 || tval=false; };
 			$rm_try;
 		fi;
 	else
-		echo "$extern_C void *$1$tdc; void *(*(p()))$tdc { return &$1; } int main() { if(p()) return(0); else return(1); }"> try.c;
+		echo "volatile int dummy = 0; $extern_C void *$1$tdc; void *(*(p()))$tdc { return dummy + &$1; } int main() { if(p()) return(0); else return(1); }"> try.c;
 		$cc -o try $optimize $ccflags $ldflags try.c $libs >/dev/null 2>&1 && tval=true;
 		$rm_try;
 	fi;