-# warnings.m4 serial 6
-dnl Copyright (C) 2008-2012 Free Software Foundation, Inc.
+# warnings.m4 serial 11
+dnl Copyright (C) 2008-2013 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.
[AS_VAR_SET([$1], [AS_VAR_GET([$1])$2])])])
-# gl_WARN_ADD(PARAMETER, [VARIABLE = WARN_CFLAGS])
-# ------------------------------------------------
-# Adds parameter to WARN_CFLAGS if the compiler supports it. For example,
-# gl_WARN_ADD([-Wparentheses]).
+# gl_COMPILER_OPTION_IF(OPTION, [IF-SUPPORTED], [IF-NOT-SUPPORTED],
+# [PROGRAM = AC_LANG_PROGRAM()])
+# -----------------------------------------------------------------
+# Check if the compiler supports OPTION when compiling PROGRAM.
#
-# If VARIABLE is a variable name, AC_SUBST it.
-AC_DEFUN([gl_WARN_ADD],
-dnl FIXME: gl_Warn must be used unquoted until we can assume
-dnl autoconf 2.64 or newer.
+# FIXME: gl_Warn must be used unquoted until we can assume Autoconf
+# 2.64 or newer.
+AC_DEFUN([gl_COMPILER_OPTION_IF],
[AS_VAR_PUSHDEF([gl_Warn], [gl_cv_warn_[]_AC_LANG_ABBREV[]_$1])dnl
AS_VAR_PUSHDEF([gl_Flags], [_AC_LANG_PREFIX[]FLAGS])dnl
+AS_LITERAL_IF([$1],
+ [m4_pushdef([gl_Positive], m4_bpatsubst([$1], [^-Wno-], [-W]))],
+ [gl_positive="$1"
+case $gl_positive in
+ -Wno-*) gl_positive=-W`expr "X$gl_positive" : 'X-Wno-\(.*\)'` ;;
+esac
+m4_pushdef([gl_Positive], [$gl_positive])])dnl
AC_CACHE_CHECK([whether _AC_LANG compiler handles $1], m4_defn([gl_Warn]), [
gl_save_compiler_FLAGS="$gl_Flags"
- gl_Flags="$gl_Flags $1"
- AC_COMPILE_IFELSE([AC_LANG_PROGRAM([])],
- [AS_VAR_SET(gl_Warn, [yes])],
- [AS_VAR_SET(gl_Warn, [no])])
+ gl_AS_VAR_APPEND(m4_defn([gl_Flags]),
+ [" $gl_unknown_warnings_are_errors ]m4_defn([gl_Positive])["])
+ AC_LINK_IFELSE([m4_default([$4], [AC_LANG_PROGRAM([])])],
+ [AS_VAR_SET(gl_Warn, [yes])],
+ [AS_VAR_SET(gl_Warn, [no])])
gl_Flags="$gl_save_compiler_FLAGS"
])
-AS_VAR_IF(gl_Warn, [yes],
- [gl_AS_VAR_APPEND(m4_if([$2], [], [[WARN_CFLAGS]], [[$2]]), [" $1"])])
+AS_VAR_IF(gl_Warn, [yes], [$2], [$3])
+m4_popdef([gl_Positive])dnl
AS_VAR_POPDEF([gl_Flags])dnl
AS_VAR_POPDEF([gl_Warn])dnl
-m4_ifval([$2], [AS_LITERAL_IF([$2], [AC_SUBST([$2])], [])])dnl
])
+
+# gl_UNKNOWN_WARNINGS_ARE_ERRORS
+# ------------------------------
+# Clang doesn't complain about unknown warning options unless one also
+# specifies -Wunknown-warning-option -Werror. Detect this.
+AC_DEFUN([gl_UNKNOWN_WARNINGS_ARE_ERRORS],
+[gl_COMPILER_OPTION_IF([-Werror -Wunknown-warning-option],
+ [gl_unknown_warnings_are_errors='-Wunknown-warning-option -Werror'],
+ [gl_unknown_warnings_are_errors=])])
+
+# gl_WARN_ADD(OPTION, [VARIABLE = WARN_CFLAGS],
+# [PROGRAM = AC_LANG_PROGRAM()])
+# ---------------------------------------------
+# Adds parameter to WARN_CFLAGS if the compiler supports it when
+# compiling PROGRAM. For example, gl_WARN_ADD([-Wparentheses]).
+#
+# If VARIABLE is a variable name, AC_SUBST it.
+AC_DEFUN([gl_WARN_ADD],
+[AC_REQUIRE([gl_UNKNOWN_WARNINGS_ARE_ERRORS])
+gl_COMPILER_OPTION_IF([$1],
+ [gl_AS_VAR_APPEND(m4_if([$2], [], [[WARN_CFLAGS]], [[$2]]), [" $1"])],
+ [],
+ [$3])
+m4_ifval([$2],
+ [AS_LITERAL_IF([$2], [AC_SUBST([$2])])],
+ [AC_SUBST([WARN_CFLAGS])])dnl
+])
+
+# Local Variables:
+# mode: autoconf
+# End: