--- a/make/autoconf/flags.m4	Mon Feb 19 23:09:18 2018 +0100
+++ b/make/autoconf/flags.m4	Mon Feb 19 23:25:11 2018 +0100
@@ -377,25 +377,25 @@
 
   FLAGS_SETUP_COMPILER_FLAGS_FOR_JDK_HELPER
 
-  FLAGS_OS=OPENJDK_TARGET_OS
-  FLAGS_OS_TYPE=OPENJDK_TARGET_OS_TYPE
-  FLAGS_CPU=OPENJDK_TARGET_CPU
-  FLAGS_CPU_ARCH=OPENJDK_TARGET_CPU_ARCH
-  FLAGS_CPU_BITS=OPENJDK_TARGET_CPU_BITS
-  FLAGS_CPU_ENDIAN=OPENJDK_TARGET_CPU_ENDIAN
-  FLAGS_CPU_LEGACY=OPENJDK_TARGET_CPU_LEGACY
-  FLAGS_ADD_LP64=OPENJDK_TARGET_ADD_LP64
+  FLAGS_OS=$OPENJDK_TARGET_OS
+  FLAGS_OS_TYPE=$OPENJDK_TARGET_OS_TYPE
+  FLAGS_CPU=$OPENJDK_TARGET_CPU
+  FLAGS_CPU_ARCH=$OPENJDK_TARGET_CPU_ARCH
+  FLAGS_CPU_BITS=$OPENJDK_TARGET_CPU_BITS
+  FLAGS_CPU_ENDIAN=$OPENJDK_TARGET_CPU_ENDIAN
+  FLAGS_CPU_LEGACY=$OPENJDK_TARGET_CPU_LEGACY
+  FLAGS_ADD_LP64=$OPENJDK_TARGET_ADD_LP64
 
   FLAGS_SETUP_COMPILER_FLAGS_FOR_JDK_CPU_DEP([TARGET])
 
-  FLAGS_OS=OPENJDK_BUILD_OS
-  FLAGS_OS_TYPE=OPENJDK_BUILD_OS_TYPE
-  FLAGS_CPU=OPENJDK_BUILD_CPU
-  FLAGS_CPU_ARCH=OPENJDK_BUILD_CPU_ARCH
-  FLAGS_CPU_BITS=OPENJDK_BUILD_CPU_BITS
-  FLAGS_CPU_ENDIAN=OPENJDK_BUILD_CPU_ENDIAN
-  FLAGS_CPU_LEGACY=OPENJDK_BUILD_CPU_LEGACY
-  FLAGS_ADD_LP64=OPENJDK_BUILD_ADD_LP64=
+  FLAGS_OS=$OPENJDK_BUILD_OS
+  FLAGS_OS_TYPE=$OPENJDK_BUILD_OS_TYPE
+  FLAGS_CPU=$OPENJDK_BUILD_CPU
+  FLAGS_CPU_ARCH=$OPENJDK_BUILD_CPU_ARCH
+  FLAGS_CPU_BITS=$OPENJDK_BUILD_CPU_BITS
+  FLAGS_CPU_ENDIAN=$OPENJDK_BUILD_CPU_ENDIAN
+  FLAGS_CPU_LEGACY=$OPENJDK_BUILD_CPU_LEGACY
+  FLAGS_ADD_LP64=$OPENJDK_BUILD_ADD_LP64
 
   FLAGS_SETUP_COMPILER_FLAGS_FOR_JDK_CPU_DEP([BUILD], [OPENJDK_BUILD_])
 
@@ -430,26 +430,26 @@
 AC_DEFUN([FLAGS_SETUP_COMPILER_FLAGS_FOR_JDK_HELPER],
 [
   #### OS DEFINES, these should be independent on toolchain
-  if test "x$FLAGS_OS" = xlinux; then
+  if test "x$OPENJDK_TARGET_OS" = xlinux; then
     CFLAGS_OS_DEF_JVM="-DLINUX"
     CFLAGS_OS_DEF_JDK="-D_GNU_SOURCE -D_REENTRANT -D_LARGEFILE64_SOURCE"
-  elif test "x$FLAGS_OS" = xsolaris; then
+  elif test "x$OPENJDK_TARGET_OS" = xsolaris; then
     CFLAGS_OS_DEF_JVM="-DSOLARIS"
     CFLAGS_OS_DEF_JDK="-D__solaris__"
-  elif test "x$FLAGS_OS" = xmacosx; then
+  elif test "x$OPENJDK_TARGET_OS" = xmacosx; then
     CFLAGS_OS_DEF_JVM="-D_ALLBSD_SOURCE -D_DARWIN_C_SOURCE -D_XOPEN_SOURCE"
     CFLAGS_OS_DEF_JDK="-D_ALLBSD_SOURCE -D_DARWIN_UNLIMITED_SELECT"
-  elif test "x$FLAGS_OS" = xaix; then
+  elif test "x$OPENJDK_TARGET_OS" = xaix; then
     CFLAGS_OS_DEF_JVM="-DAIX"
-  elif test "x$FLAGS_OS" = xbsd; then
+  elif test "x$OPENJDK_TARGET_OS" = xbsd; then
     CFLAGS_OS_DEF_JDK="-D_ALLBSD_SOURCE"
-  elif test "x$FLAGS_OS" = xwindows; then
+  elif test "x$OPENJDK_TARGET_OS" = xwindows; then
     CFLAGS_OS_DEF_JVM="-D_WINDOWS -DWIN32 -D_JNI_IMPLEMENTATION_"
   fi
 
   # Setup target OS define. Use OS target name but in upper case.
-  FLAGS_OS_UPPERCASE=`$ECHO $FLAGS_OS | $TR 'abcdefghijklmnopqrstuvwxyz' 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'`
-  CFLAGS_OS_DEF_JDK="$CFLAGS_OS_DEF_JDK -D$FLAGS_OS_UPPERCASE"
+  OPENJDK_TARGET_OS_UPPERCASE=`$ECHO $OPENJDK_TARGET_OS | $TR 'abcdefghijklmnopqrstuvwxyz' 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'`
+  CFLAGS_OS_DEF_JDK="$CFLAGS_OS_DEF_JDK -D$OPENJDK_TARGET_OS_UPPERCASE"
 
   #### GLOBAL DEFINES
   # Set some common defines. These works for all compilers, but assume
@@ -463,7 +463,7 @@
       -I\$(SUPPORT_OUTPUTDIR)/modules_include/java.base \
       -I\$(SUPPORT_OUTPUTDIR)/modules_include/java.base/\$(OPENJDK_TARGET_OS_INCLUDE_SUBDIR) \
       -I${TOPDIR}/src/java.base/share/native/libjava \
-      -I${TOPDIR}/src/java.base/$FLAGS_OS_TYPE/native/libjava \
+      -I${TOPDIR}/src/java.base/$OPENJDK_TARGET_OS_TYPE/native/libjava \
       -I${TOPDIR}/src/hotspot/share/include \
       -I${TOPDIR}/src/hotspot/os/${HOTSPOT_TARGET_OS_TYPE}/include"
 
@@ -473,7 +473,7 @@
   # Setup debug/release defines
   if test "x$DEBUG_LEVEL" = xrelease; then
     DEBUG_CFLAGS_JDK="-DNDEBUG"
-    if test "x$FLAGS_OS" = xsolaris; then
+    if test "x$OPENJDK_TARGET_OS" = xsolaris; then
       DEBUG_CFLAGS_JDK="$DEBUG_CFLAGS_JDK -DTRIMMED"
     fi
   else
@@ -525,7 +525,7 @@
     TOOLCHAIN_CFLAGS_JDK="-pipe"
     TOOLCHAIN_CFLAGS_JDK_CONLY="-fno-strict-aliasing" # technically NOT for CXX (but since this gives *worse* performance, use no-strict-aliasing everywhere!)
 
-    CXXSTD_CXXFLAG="-std=gnu++98" # only for CXX and JVM
+    CXXSTD_CXXFLAG="-std=gnu++98"
     FLAGS_CXX_COMPILER_CHECK_ARGUMENTS(ARGUMENT: [$CXXSTD_CXXFLAG -Werror],
     						 IF_FALSE: [CXXSTD_CXXFLAG=""])
     TOOLCHAIN_CFLAGS_JDK_CXXONLY="$CXXSTD_CXXFLAG"
@@ -539,7 +539,7 @@
     # (see http://llvm.org/bugs/show_bug.cgi?id=7554)
     TOOLCHAIN_CFLAGS_JVM="$TOOLCHAIN_CFLAGS_JVM -flimit-debug-info"
 
-    if test "x$FLAGS_OS" = xlinux; then
+    if test "x$OPENJDK_TARGET_OS" = xlinux; then
       TOOLCHAIN_CFLAGS_JDK="-pipe"
       TOOLCHAIN_CFLAGS_JDK_CONLY="-fno-strict-aliasing" # technically NOT for CXX
     fi
@@ -580,7 +580,7 @@
     fi
   elif test "x$TOOLCHAIN_TYPE" = xclang; then
     WARNING_CFLAGS_JVM="$WARNING_CFLAGS_JVM -Wno-deprecated"
-    if test "x$FLAGS_OS" = xlinux; then
+    if test "x$OPENJDK_TARGET_OS" = xlinux; then
       WARNING_CFLAGS_JVM="$WARNING_CFLAGS_JVM -Wno-sometimes-uninitialized"
       WARNING_CFLAGS_JDK="-Wall -Wextra -Wno-unused -Wno-unused-parameter -Wformat=2"
     fi
@@ -596,7 +596,7 @@
   # Set some additional per-OS defines.
 
   # Additional macosx handling
-  if test "x$FLAGS_OS" = xmacosx; then
+  if test "x$OPENJDK_TARGET_OS" = xmacosx; then
     # Let the flags variables get resolved in make for easier override on make
     # command line. AvailabilityMacros.h versions have no dots, ex: 1070.
     OS_CFLAGS="-DMAC_OS_X_VERSION_MIN_REQUIRED=\$(subst .,,\$(MACOSX_VERSION_MIN)) \
@@ -609,9 +609,9 @@
   fi
 
   # Where does this really belong??
-  if test "x$FLAGS_OS" = xlinux; then
+  if test "x$OPENJDK_TARGET_OS" = xlinux; then
     OS_CFLAGS_JVM="$OS_CFLAGS_JVM $PICFLAG"
-  elif test "x$FLAGS_OS" = xmacosx; then
+  elif test "x$OPENJDK_TARGET_OS" = xmacosx; then
     OS_CFLAGS_JVM="$OS_CFLAGS_JVM -mno-omit-leaf-frame-pointer -mstack-alignment=16"
   fi
   # Optional POSIX functionality needed by the VM
@@ -733,7 +733,7 @@
 
   if test "x$TOOLCHAIN_TYPE" = xgcc; then
     TOOLCHAIN_CHECK_COMPILER_VERSION(VERSION: 6, PREFIX: $2, IF_AT_LEAST: FLAGS_SETUP_GCC6_COMPILER_FLAGS($1))
-    $1_TOOLCHAIN_CFLAGS="$1_GCC6_CFLAGS"
+    $1_TOOLCHAIN_CFLAGS="${$1_GCC6_CFLAGS}"
 
     TOOLCHAIN_CHECK_COMPILER_VERSION(VERSION: [4.8], PREFIX: $2,
         IF_AT_LEAST: [
@@ -756,8 +756,8 @@
   CFLAGS_JDK_COMMON_CXXONLY="$ALWAYS_DEFINES_JDK_CXXONLY $TOOLCHAIN_CFLAGS_JDK_CXXONLY \
       $WARNING_CFLAGS_JDK_CXXONLY $EXTRA_CXXFLAGS"
 
-  $1_CFLAGS_JVM="$1_DEFINES_CPU_JVM $1_CFLAGS_CPU $1_CFLAGS_CPU_JVM $1_TOOLCHAIN_CFLAGS $1_WARNING_CFLAGS_JVM"
-  $1_CFLAGS_JDK="$1_DEFINES_CPU_JDK $1_CFLAGS_CPU $1_CFLAGS_CPU_JDK $1_TOOLCHAIN_CFLAGS"
+  $1_CFLAGS_JVM="${$1_DEFINES_CPU_JVM} ${$1_CFLAGS_CPU} ${$1_CFLAGS_CPU_JVM} ${$1_TOOLCHAIN_CFLAGS} ${$1_WARNING_CFLAGS_JVM}"
+  $1_CFLAGS_JDK="${$1_DEFINES_CPU_JDK} ${$1_CFLAGS_CPU} ${$1_CFLAGS_CPU_JDK} ${$1_TOOLCHAIN_CFLAGS}"
 
   $2JVM_CFLAGS="$CFLAGS_JVM_COMMON ${$1_CFLAGS_JVM}"