# stdarg.m4 serial 6

dnl Copyright (C) 2006, 2008-2017 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])

])