https://bugs.gentoo.org/581346

From 34104ea9e635fae5551fd1d6495a80f8041c4adc Mon Sep 17 00:00:00 2001
From: "Enrico M. Crisostomo" <enrico.m.crisostomo@gmail.com>
Date: Sun, 20 Mar 2016 14:17:15 +0100
Subject: [PATCH] Update CXXCPP after updating CXX.

Rewrap text.

Rewrap.
---
 m4/ax_cxx_compile_stdcxx.m4    | 14 ++++++++++----
 m4/ax_cxx_compile_stdcxx_11.m4 |  5 +++--
 m4/ax_cxx_compile_stdcxx_14.m4 |  5 +++--
 3 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/m4/ax_cxx_compile_stdcxx.m4 b/m4/ax_cxx_compile_stdcxx.m4
index 8adc765..2c18e49 100644
--- a/m4/ax_cxx_compile_stdcxx.m4
+++ b/m4/ax_cxx_compile_stdcxx.m4
@@ -9,9 +9,9 @@
 # DESCRIPTION
 #
 #   Check for baseline language coverage in the compiler for the specified
-#   version of the C++ standard.  If necessary, add switches to CXX to
-#   enable support.  VERSION may be '11' (for the C++11 standard) or '14'
-#   (for the C++14 standard).
+#   version of the C++ standard.  If necessary, add switches to CXX and
+#   CXXCPP to enable support.  VERSION may be '11' (for the C++11 standard)
+#   or '14' (for the C++14 standard).
 #
 #   The second argument, if specified, indicates whether you insist on an
 #   extended mode (e.g. -std=gnu++11) or a strict conformance mode (e.g.
@@ -39,7 +39,7 @@
 #   and this notice are preserved.  This file is offered as-is, without any
 #   warranty.
 
-#serial 3
+#serial 4
 
 dnl  This macro is based on the code from the AX_CXX_COMPILE_STDCXX_11 macro
 dnl  (serial version number 13).
@@ -82,6 +82,9 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl
          CXX="$ac_save_CXX"])
       if eval test x\$$cachevar = xyes; then
         CXX="$CXX $switch"
+        if test -n "$CXXCPP" ; then
+          CXXCPP="$CXXCPP $switch"
+        fi
         ac_success=yes
         break
       fi
@@ -105,6 +108,9 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl
          CXX="$ac_save_CXX"])
       if eval test x\$$cachevar = xyes; then
         CXX="$CXX $switch"
+        if test -n "$CXXCPP" ; then
+          CXXCPP="$CXXCPP $switch"
+        fi
         ac_success=yes
         break
       fi
diff --git a/m4/ax_cxx_compile_stdcxx_11.m4 b/m4/ax_cxx_compile_stdcxx_11.m4
index b3d4bfd..3dd5cf9 100644
--- a/m4/ax_cxx_compile_stdcxx_11.m4
+++ b/m4/ax_cxx_compile_stdcxx_11.m4
@@ -9,7 +9,8 @@
 # DESCRIPTION
 #
 #   Check for baseline language coverage in the compiler for the C++11
-#   standard; if necessary, add switches to CXX to enable support.
+#   standard; if necessary, add switches to CXX and CXXCPP to enable
+#   support.
 #
 #   This macro is a convenience alias for calling the AX_CXX_COMPILE_STDCXX
 #   macro with the version set to C++11.  The two optional arguments are
@@ -32,7 +33,7 @@
 #   and this notice are preserved. This file is offered as-is, without any
 #   warranty.
 
-#serial 15
+#serial 16
 
 include([ax_cxx_compile_stdcxx.m4])
 
diff --git a/m4/ax_cxx_compile_stdcxx_14.m4 b/m4/ax_cxx_compile_stdcxx_14.m4
index 741accf..6d2123a 100644
--- a/m4/ax_cxx_compile_stdcxx_14.m4
+++ b/m4/ax_cxx_compile_stdcxx_14.m4
@@ -9,7 +9,8 @@
 # DESCRIPTION
 #
 #   Check for baseline language coverage in the compiler for the C++14
-#   standard; if necessary, add switches to CXX to enable support.
+#   standard; if necessary, add switches to CXX and CXXCPP to enable
+#   support.
 #
 #   This macro is a convenience alias for calling the AX_CXX_COMPILE_STDCXX
 #   macro with the version set to C++14.  The two optional arguments are
@@ -27,7 +28,7 @@
 #   and this notice are preserved. This file is offered as-is, without any
 #   warranty.
 
-#serial 2
+#serial 3
 
 include([ax_cxx_compile_stdcxx.m4])
 
-- 
2.8.2