From 52b29a3314e7dc2b1ca096ee39d78b12611982bc Mon Sep 17 00:00:00 2001
From: ngoto <ngoto@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Wed, 16 May 2018 03:57:50 +0000
Subject: [PATCH] configure.ac: revert r63438

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63442 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 configure.ac | 23 +++++++++++------------
 1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/configure.ac b/configure.ac
index 09cf8687fa..f467a85ee9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -836,7 +836,16 @@ main()
 		    AS_IF([test x"$define_xopen_source" != x], [
 		        break
 		    ])
-		    RUBY_WERROR_FLAG([AC_TRY_COMPILE([
+		    # Both AC_TRY_CPP and AC_TRY_COMPILE should pass
+		    # because some options may not be set to CPPFLAGS.
+		    AC_TRY_CPP([
+			#define _XOPEN_SOURCE ${tmp_xpg}00
+			#include <unistd.h>
+			#ifndef _XPG${tmp_xpg}
+			#error _XPG${tmp_xpg} should be defined by _XOPEN_SOURCE=${tmp_xpg}00
+			#endif
+			], [
+			AC_TRY_COMPILE([
 			#define _XOPEN_SOURCE ${tmp_xpg}00
 			#include <unistd.h>
 			#ifndef _XPG${tmp_xpg}
@@ -844,7 +853,7 @@ main()
 			#endif
 			], [],
 			[define_xopen_source=${tmp_xpg}00], [])
-			])
+			], [])
 		  done
 		  AS_IF([test x"$define_xopen_source" = x], [
 		    define_xopen_source=no
@@ -852,16 +861,6 @@ main()
 		  AC_MSG_RESULT($define_xopen_source)
 		  AS_IF([test x"$define_xopen_source" != xno], [
 		    RUBY_APPEND_OPTIONS(CPPFLAGS, -D_XOPEN_SOURCE=$define_xopen_source)
-		    # On Solaris, with gcc, "-std=gnu99" would be needed
-		    # for using "-D_XOPEN_SOURCE=nnn" when nnn >= 600.
-		    # ("-std=gnu99" have been added to both $warnflags and
-		    #  $strict_warnflags. During the above AC_TRY_COMPILE,
-		    #  $warnflags is effective, but the value will later be
-		    #  replaced with $rb_cv_warnflags.)
-		    AS_CASE(["${warnflags}"],
-		    [*-std=gnu99*], [
-		      RUBY_APPEND_OPTIONS(CPPFLAGS, -std=gnu99)
-		    ])
 		  ])
 		])
 		],