* configure.in: enable -fPIE when checking -pie for fixing

OpenBSD build error. Patch by George Koehler. Thank you!
  [Bug #7606] [ruby-core:51082]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38619 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,9 @@
+Wed Dec 26 11:54:11 2012  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
+
+	* configure.in: enable -fPIE when checking -pie for fixing
+	  OpenBSD build error. Patch by George Koehler. Thank you!
+	  [Bug #7606] [ruby-core:51082]
+
 Wed Dec 26 07:31:24 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* string.c (rb_enc_cr_str_copy_for_substr): empty string is always

configure.in

@@ -2708,14 +2708,21 @@ AS_CASE("$enable_shared", [yes], [
   if test "$GCC" = yes -a -z "$EXTSTATIC" -a "x$pie" != xno; then
     RUBY_TRY_CFLAGS(-fPIE, [pie=yes], [pie=no])
     if test "$pie" = yes; then
-      RUBY_APPEND_OPTION(XCFLAGS, -fPIE)
+      # Use -fPIE when testing -pie.  RUBY_TRY_LDFLAGS sets
+      # $save_CFLAGS internally, so set other name here.
+      save_CFLAGS_before_pie="$CFLAGS"
+      CFLAGS="$CFLAGS -fPIE"
+
+      # gcc need -pie but clang need -Wl,-pie.
       for pie in -pie -Wl,-pie; do
 	RUBY_TRY_LDFLAGS([$pie], [], [pie=])
 	if test "x$pie" != x; then
+	  RUBY_APPEND_OPTION(XCFLAGS, -fPIE)
 	  RUBY_APPEND_OPTION(XLDFLAGS, $pie)
 	  break
 	fi
       done
+      CFLAGS="$save_CFLAGS_before_pie"
     fi
   fi
 ])