2 dnl Copyright (C) 2008-2012 Free Software Foundation, Inc.
3 dnl This file is free software; the Free Software Foundation
4 dnl gives unlimited permission to copy and/or distribute it,
5 dnl with or without modifications, as long as this notice is preserved.
7 dnl From Simon Josefsson
9 # gl_AS_VAR_APPEND(VAR, VALUE)
10 # ----------------------------
11 # Provide the functionality of AS_VAR_APPEND if Autoconf does not have it.
12 m4_ifdef([AS_VAR_APPEND],
13 [m4_copy([AS_VAR_APPEND], [gl_AS_VAR_APPEND])],
14 [m4_define([gl_AS_VAR_APPEND],
15 [AS_VAR_SET([$1], [AS_VAR_GET([$1])$2])])])
18 # gl_WARN_ADD(PARAMETER, [VARIABLE = WARN_CFLAGS])
19 # ------------------------------------------------
20 # Adds parameter to WARN_CFLAGS if the compiler supports it. For example,
21 # gl_WARN_ADD([-Wparentheses]).
23 # If VARIABLE is a variable name, AC_SUBST it.
24 AC_DEFUN([gl_WARN_ADD],
25 dnl FIXME: gl_Warn must be used unquoted until we can assume
26 dnl autoconf 2.64 or newer.
27 [AS_VAR_PUSHDEF([gl_Warn], [gl_cv_warn_[]_AC_LANG_ABBREV[]_$1])dnl
28 AS_VAR_PUSHDEF([gl_Flags], [_AC_LANG_PREFIX[]FLAGS])dnl
29 AC_CACHE_CHECK([whether _AC_LANG compiler handles $1], m4_defn([gl_Warn]), [
30 gl_save_compiler_FLAGS="$gl_Flags"
31 gl_Flags="$gl_Flags $1"
32 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([])],
33 [AS_VAR_SET(gl_Warn, [yes])],
34 [AS_VAR_SET(gl_Warn, [no])])
35 gl_Flags="$gl_save_compiler_FLAGS"
37 AS_VAR_IF(gl_Warn, [yes],
38 [gl_AS_VAR_APPEND(m4_if([$2], [], [[WARN_CFLAGS]], [[$2]]), [" $1"])])
39 AS_VAR_POPDEF([gl_Flags])dnl
40 AS_VAR_POPDEF([gl_Warn])dnl
41 m4_ifval([$2], [AS_LITERAL_IF([$2], [AC_SUBST([$2])], [])])dnl