libgo: Add --enable-werror configure option.

From-SVN: r195482

libgo/configure

@@ -809,6 +809,7 @@ enable_static
 with_pic
 enable_fast_install
 enable_libtool_lock
+enable_werror
 enable_version_specific_runtime_libs
 with_libffi
 with_system_libunwind
@@ -1449,6 +1450,7 @@ Optional Features:
   --enable-fast-install[=PKGS]
                           optimize for fast installation [default=yes]
   --disable-libtool-lock  avoid locking (might break parallel builds)
+  --enable-werror         turns on -Werror [default=yes]
   --enable-version-specific-runtime-libs
                           Specify that runtime libraries should be installed
                           in a compiler-specific directory
@@ -11102,7 +11104,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11105 "configure"
+#line 11107 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -11208,7 +11210,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11211 "configure"
+#line 11213 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -13386,7 +13388,14 @@ done
 WARN_FLAGS='-Wall -Wextra -Wwrite-strings -Wcast-qual'
 
 
-WERROR="-Werror"
+# Check whether --enable-werror was given.
+if test "${enable_werror+set}" = set; then :
+  enableval=$enable_werror;
+fi
+
+if test "x$enable_werror" != "xno"; then
+  WERROR="-Werror"
+fi
 
 
 glibgo_toolexecdir=no

libgo/configure.ac

@@ -50,8 +50,11 @@ AC_PROG_AWK
 WARN_FLAGS='-Wall -Wextra -Wwrite-strings -Wcast-qual'
 AC_SUBST(WARN_FLAGS)
 
-dnl FIXME: This should be controlled by --enable-maintainer-mode.
-WERROR="-Werror"
+AC_ARG_ENABLE(werror, [AS_HELP_STRING([--enable-werror],
+                                      [turns on -Werror @<:@default=yes@:>@])])
+if test "x$enable_werror" != "xno"; then
+  WERROR="-Werror"
+fi
 AC_SUBST(WERROR)
 
 glibgo_toolexecdir=no