2017-04-14  Bernd Edlinger  <bernd.edlinger@hotmail.de>

	* configure.ac (SYSTEM_HEADER_DIR, BUILD_SYSTEM_HEADER_DIR,
	target_header_dir): Set correctly.
	* configure: Regenerated.
	* Makefile.in (BUILD_SYSTEM_HEADER_DIR): Use directly.

Index: gcc/configure
===================================================================
--- gcc/configure	(revision 246899)
+++ gcc/configure	(working copy)
@@ -719,6 +719,7 @@ BUILD_CFLAGS
 CXX_FOR_BUILD
 CC_FOR_BUILD
 inhibit_libc
+BUILD_SYSTEM_HEADER_DIR
 SYSTEM_HEADER_DIR
 ALL
 CROSS
@@ -12214,14 +12215,15 @@ done
 CROSS=
 ALL=all.internal
 SYSTEM_HEADER_DIR='$(NATIVE_SYSTEM_HEADER_DIR)'
+BUILD_SYSTEM_HEADER_DIR=$SYSTEM_HEADER_DIR
 
 if test "x$with_build_sysroot" != x; then
-  build_system_header_dir=$with_build_sysroot'$${sysroot_headers_suffix}$(NATIVE_SYSTEM_HEADER_DIR)'
-else
+  BUILD_SYSTEM_HEADER_DIR=$with_build_sysroot'$${sysroot_headers_suffix}$(NATIVE_SYSTEM_HEADER_DIR)'
+elif test x$host != x$target; then
   # This value is used, even on a native system, because
   # CROSS_SYSTEM_HEADER_DIR is just
   # $(TARGET_SYSTEM_ROOT)$(NATIVE_SYSTEM_HEADER_DIR).
-  build_system_header_dir='$(CROSS_SYSTEM_HEADER_DIR)'
+  BUILD_SYSTEM_HEADER_DIR='$(CROSS_SYSTEM_HEADER_DIR)'
 fi
 
 if test x$host != x$target
@@ -12228,7 +12230,7 @@ if test x$host != x$target
 then
 	CROSS="-DCROSS_DIRECTORY_STRUCTURE"
 	ALL=all.cross
-	SYSTEM_HEADER_DIR=$build_system_header_dir
+	SYSTEM_HEADER_DIR=$BUILD_SYSTEM_HEADER_DIR
 	case $target in
 		*-*-mingw*)
 			if test "x$with_headers" = x; then
@@ -12239,16 +12241,17 @@ then
 			;;
 	esac
 elif test "x$TARGET_SYSTEM_ROOT" != x; then
-        SYSTEM_HEADER_DIR=$build_system_header_dir
+	SYSTEM_HEADER_DIR='$(CROSS_SYSTEM_HEADER_DIR)'
 fi
 
-if test x$host != x$target || test "x$TARGET_SYSTEM_ROOT" != x; then
+if test x$host != x$target || test "x$TARGET_SYSTEM_ROOT" != x ||
+   test x$build != x$host || test "x$with_build_sysroot" != x; then
   if test "x$with_headers" != x && test "x$with_headers" != xyes; then
     target_header_dir=$with_headers
+  elif test "x$with_build_sysroot" != "x"; then
+    target_header_dir="${with_build_sysroot}${native_system_header_dir}"
   elif test "x$with_sysroot" = x; then
     target_header_dir="${test_exec_prefix}/${target_noncanonical}/sys-include"
-  elif test "x$with_build_sysroot" != "x"; then
-    target_header_dir="${with_build_sysroot}${native_system_header_dir}"
   elif test "x$with_sysroot" = xyes; then
     target_header_dir="${test_exec_prefix}/${target_noncanonical}/sys-root${native_system_header_dir}"
   else
@@ -18433,7 +18436,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 18436 "configure"
+#line 18439 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -18539,7 +18542,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 18542 "configure"
+#line 18545 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
Index: gcc/configure.ac
===================================================================
--- gcc/configure.ac	(revision 246899)
+++ gcc/configure.ac	(working copy)
@@ -1998,14 +1998,15 @@ done
 CROSS=						AC_SUBST(CROSS)
 ALL=all.internal				AC_SUBST(ALL)
 SYSTEM_HEADER_DIR='$(NATIVE_SYSTEM_HEADER_DIR)'	AC_SUBST(SYSTEM_HEADER_DIR)
+BUILD_SYSTEM_HEADER_DIR=$SYSTEM_HEADER_DIR	AC_SUBST(BUILD_SYSTEM_HEADER_DIR)
 
 if test "x$with_build_sysroot" != x; then
-  build_system_header_dir=$with_build_sysroot'$${sysroot_headers_suffix}$(NATIVE_SYSTEM_HEADER_DIR)'
-else
+  BUILD_SYSTEM_HEADER_DIR=$with_build_sysroot'$${sysroot_headers_suffix}$(NATIVE_SYSTEM_HEADER_DIR)'
+elif test x$host != x$target; then
   # This value is used, even on a native system, because 
   # CROSS_SYSTEM_HEADER_DIR is just 
   # $(TARGET_SYSTEM_ROOT)$(NATIVE_SYSTEM_HEADER_DIR).
-  build_system_header_dir='$(CROSS_SYSTEM_HEADER_DIR)'
+  BUILD_SYSTEM_HEADER_DIR='$(CROSS_SYSTEM_HEADER_DIR)'
 fi
 
 if test x$host != x$target
@@ -2012,7 +2013,7 @@ if test x$host != x$target
 then
 	CROSS="-DCROSS_DIRECTORY_STRUCTURE"
 	ALL=all.cross
-	SYSTEM_HEADER_DIR=$build_system_header_dir
+	SYSTEM_HEADER_DIR=$BUILD_SYSTEM_HEADER_DIR
 	case $target in
 		*-*-mingw*)
 			if test "x$with_headers" = x; then
@@ -2023,16 +2024,17 @@ then
 			;;
 	esac
 elif test "x$TARGET_SYSTEM_ROOT" != x; then
-        SYSTEM_HEADER_DIR=$build_system_header_dir 
+	SYSTEM_HEADER_DIR='$(CROSS_SYSTEM_HEADER_DIR)'
 fi
 
-if test x$host != x$target || test "x$TARGET_SYSTEM_ROOT" != x; then
+if test x$host != x$target || test "x$TARGET_SYSTEM_ROOT" != x ||
+   test x$build != x$host || test "x$with_build_sysroot" != x; then
   if test "x$with_headers" != x && test "x$with_headers" != xyes; then
     target_header_dir=$with_headers
+  elif test "x$with_build_sysroot" != "x"; then
+    target_header_dir="${with_build_sysroot}${native_system_header_dir}"
   elif test "x$with_sysroot" = x; then
     target_header_dir="${test_exec_prefix}/${target_noncanonical}/sys-include"
-  elif test "x$with_build_sysroot" != "x"; then
-    target_header_dir="${with_build_sysroot}${native_system_header_dir}"
   elif test "x$with_sysroot" = xyes; then
     target_header_dir="${test_exec_prefix}/${target_noncanonical}/sys-root${native_system_header_dir}"
   else
Index: gcc/Makefile.in
===================================================================
--- gcc/Makefile.in	(revision 246899)
+++ gcc/Makefile.in	(working copy)
@@ -518,11 +518,7 @@ CROSS_SYSTEM_HEADER_DIR = @CROSS_SYSTEM_HEADER_DIR
 SYSTEM_HEADER_DIR = `echo @SYSTEM_HEADER_DIR@ | sed -e :a -e 's,[^/]*/\.\.\/,,' -e ta`
 
 # Path to the system headers on the build machine
-ifeq ($(build),$(host))
-BUILD_SYSTEM_HEADER_DIR = $(SYSTEM_HEADER_DIR)
-else
-BUILD_SYSTEM_HEADER_DIR = `echo $(CROSS_SYSTEM_HEADER_DIR) | sed -e :a -e 's,[^/]*/\.\.\/,,' -e ta`
-endif
+BUILD_SYSTEM_HEADER_DIR = `echo @BUILD_SYSTEM_HEADER_DIR@ | sed -e :a -e 's,[^/]*/\.\.\/,,' -e ta`
 
 # Control whether to run fixincludes.
 STMP_FIXINC = @STMP_FIXINC@