Re: printf and NL_ARGMAX

[Jeff Johnston <jjohnstn at redhat dot com>]

Eric Blake wrote:
> Currently, if configured with --enable-newlib-io-pos-args, printf
> hard-codes the decision of how many %n$ positional parameters to support
> with MAX_POS_ARGS set to 32.  But since I hope to fix scanf to also
> support positional parameters, this should probably be fixed to follow
> POSIX and refer to NL_ARGMAX in limits.h.  Furthermore, POSIX only
> requires support for 9 positional parameters, so it should be possible for
> newlib clients to alter how much storage printf requires by setting
> NL_ARGMAX in their limits.h override.
>
> OK to apply?
>
>   
Ok.

-- Jeff J.
> 2007-04-21  Eric Blake  <ebb9@byu.net>
>
> 	* libc/include/limits.h (NL_ARGMAX): Define a default value.
> 	* libc/stdio/vfprintf.c (MAX_POS_ARGS): Define in terms of
> 	NL_ARGMAX, if present.
>
>   
> ------------------------------------------------------------------------
>
> Index: libc/include/limits.h
> ===================================================================
> RCS file: /cvs/src/src/newlib/libc/include/limits.h,v
> retrieving revision 1.1
> diff -u -p -r1.1 limits.h
> --- libc/include/limits.h	11 Sep 2002 18:36:39 -0000	1.1
> +++ libc/include/limits.h	21 Apr 2007 12:46:51 -0000
> @@ -9,6 +9,11 @@
>  #  define MB_LEN_MAX    1
>  # endif
>  
> +/* Maximum number of positional arguments, if _WANT_IO_POS_ARGS.  */
> +# ifndef NL_ARGMAX
> +#  define NL_ARGMAX 32
> +# endif
> +
>  /* if do not have #include_next support, then we
>     have to define the limits here. */
>  # if !defined __GNUC__ || __GNUC__ < 2
> @@ -124,4 +129,3 @@
>  /* `_GCC_LIMITS_H_' is what GCC's file defines.  */
>  # include_next <limits.h>
>  #endif /* __GNUC__ && !_GCC_LIMITS_H_ */
> -
> Index: libc/stdio/vfprintf.c
> ===================================================================
> RCS file: /cvs/src/src/newlib/libc/stdio/vfprintf.c,v
> retrieving revision 1.49
> diff -u -p -r1.49 vfprintf.c
> --- libc/stdio/vfprintf.c	13 Apr 2007 01:57:33 -0000	1.49
> +++ libc/stdio/vfprintf.c	21 Apr 2007 12:46:51 -0000
> @@ -320,7 +320,11 @@ typedef int  *   int_ptr_t;
>  typedef short *  short_ptr_t;
>  
>  #ifndef _NO_POS_ARGS
> -#define MAX_POS_ARGS 32
> +# ifdef NL_ARGMAX
> +#  define MAX_POS_ARGS NL_ARGMAX
> +# else
> +#  define MAX_POS_ARGS 32
> +# endif
>  
>  union arg_val
>  {
>