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emacs/m4/stdarg.m4

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# stdarg.m4 serial 6
dnl Copyright (C) 2006, 2008-2011 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.
dnl From Bruno Haible.
dnl Provide a working va_copy in combination with <stdarg.h>.
AC_DEFUN([gl_STDARG_H],
[
STDARG_H=''
NEXT_STDARG_H='<stdarg.h>'
AC_MSG_CHECKING([for va_copy])
AC_CACHE_VAL([gl_cv_func_va_copy], [
AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM(
[[#include <stdarg.h>]],
[[
#ifndef va_copy
void (*func) (va_list, va_list) = va_copy;
#endif
]])],
[gl_cv_func_va_copy=yes],
[gl_cv_func_va_copy=no])])
AC_MSG_RESULT([$gl_cv_func_va_copy])
if test $gl_cv_func_va_copy = no; then
dnl Provide a substitute.
dnl Usually a simple definition in <config.h> is enough. Not so on AIX 5
dnl with some versions of the /usr/vac/bin/cc compiler. It has an <stdarg.h>
dnl which does '#undef va_copy', leading to a missing va_copy symbol. For
dnl this platform, we use an <stdarg.h> substitute. But we cannot use this
dnl approach on other platforms, because <stdarg.h> often defines only
dnl preprocessor macros and gl_ABSOLUTE_HEADER, gl_CHECK_NEXT_HEADERS do
dnl not work in this situation.
AC_EGREP_CPP([vaccine],
[#if defined _AIX && !defined __GNUC__
AIX vaccine
#endif
], [gl_aixcc=yes], [gl_aixcc=no])
if test $gl_aixcc = yes; then
dnl Provide a substitute <stdarg.h> file.
STDARG_H=stdarg.h
gl_NEXT_HEADERS([stdarg.h])
dnl Fallback for the case when <stdarg.h> contains only macro definitions.
if test "$gl_cv_next_stdarg_h" = '""'; then
gl_cv_next_stdarg_h='"///usr/include/stdarg.h"'
NEXT_STDARG_H="$gl_cv_next_stdarg_h"
fi
else
dnl Provide a substitute in <config.h>, either __va_copy or as a simple
dnl assignment.
gl_CACHE_VAL_SILENT([gl_cv_func___va_copy], [
AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM(
[[#include <stdarg.h>]],
[[
#ifndef __va_copy
error, bail out
#endif
]])],
[gl_cv_func___va_copy=yes],
[gl_cv_func___va_copy=no])])
if test $gl_cv_func___va_copy = yes; then
AC_DEFINE([va_copy], [__va_copy],
[Define as a macro for copying va_list variables.])
else
AH_VERBATIM([gl_VA_COPY], [/* A replacement for va_copy, if needed. */
#define gl_va_copy(a,b) ((a) = (b))])
AC_DEFINE([va_copy], [gl_va_copy],
[Define as a macro for copying va_list variables.])
fi
fi
fi
AC_SUBST([STDARG_H])
AM_CONDITIONAL([GL_GENERATE_STDARG_H], [test -n "$STDARG_H"])
AC_SUBST([NEXT_STDARG_H])
])