From 00fac76efac8b30e32cd8c7fa8ef060bb083f651 Mon Sep 17 00:00:00 2001
From: k0kubun <k0kubun@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Mon, 19 Nov 2018 23:05:11 +0000
Subject: [PATCH] configure.ac: avoid crashing MJIT with -fcf-protection

by avoiding using __builtin_longjmp, like r64983.

[Bug #15307]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65815 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 configure.ac | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/configure.ac b/configure.ac
index 2c9b5de6fc..a0882a0c0f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1001,6 +1001,12 @@ main()
 		AS_CASE(["$target_cpu"], [powerpc64*], [
 			ac_cv_func___builtin_setjmp=no
 		])
+		# With gcc-8's -fcf-protection, MJIT's __builtin_longjmp fails.
+		# TODO: Check if CFLAGS actually includes -fcf-protection instead of using RUBY_TRY_CFLAGS
+		RUBY_TRY_CFLAGS(-fcf-protection, [cf_protection=yes], [cf_protection=no])
+		AS_IF([test "$cf_protection" = yes], [
+			ac_cv_func___builtin_setjmp=no
+		])
 		],
 [	LIBS="-lm $LIBS"])
 : ${ORIG_LIBS=$LIBS}