Re: [PATCHv3] m4sugar: factor away _AS_ECHO_PREPARE.

[Nick Bowler]

On 2013-01-29 19:26 +0100, Stefano Lattarini wrote:
> On 01/29/2013 07:17 AM, Gary V. Vaughan wrote:
[...]
> >  # Find who we are.  Look in the path if we contain no directory separator.
> > @@ -1023,63 +1025,15 @@ fi
> >  # Output WORD followed by a newline.  WORD must be a single shell word
> >  # (typically a quoted string).  The bytes of WORD are output as-is, even
> >  # if it starts with "-" or contains "\".
> > -m4_defun_init([AS_ECHO],
> > -[AS_REQUIRE([_$0_PREPARE])],
> > -[$as_echo $1])
> > +m4_defun([AS_ECHO],
> > +[printf '%s\n' $1])
> >  
> This won't work as expected with some invocation like:
> 
>   AS_ECHO([1 2 3])
> 
> as the generated code will print:
> 
>   1
>   2
>   3
> 
> rather than the (IMHO) expected:
> 
>   1 2 3
> 
> This is *not* a regression, since this issue was already in the
> existing code; but it would be nice to have it fixed in a follow-up
> patch.

FYI, the Autoconf manual[1] explicitly says that such usage is not
allowed:

  Macro: AS_ECHO (word)
  ...
  word must be a single shell word (typically a quoted string).

[1] 
https://gnu.org/software/autoconf/manual/autoconf.html#index-AS_005fECHO-1564

Cheers,
-- 
Nick Bowler, Elliptic Technologies (http://www.elliptictech.com/)