Re: [SCM] GNU Autoconf source repository branch, master, updated. v2.63-260-g76b4449

[Ralf Wildenhues]

[ moving from autoconf-commit ]

Hi Eric,

* Eric Blake wrote on Thu, Jan 22, 2009 at 04:28:58PM CET:
> commit 76b444921d13dd34e647efc662431f7b563c503d
> Author: Eric Blake <address@hidden>
> Date:   Thu Jan 22 08:08:06 2009 -0700
> 
>     Silence a false positive expand-before-require case.

> --- a/lib/m4sugar/m4sugar.m4
> +++ b/lib/m4sugar/m4sugar.m4
> @@ -1723,28 +1723,34 @@ m4_define([m4_undivert],
>  #
>  # The problem can only occur if a single defun'd macro first provides,
>  # then later indirectly requires, the same macro.  Note that directly
> -# expanding then requiring a macro is okay, since the requirement will
> -# be a no-op; the problem is only present if the requirement is nested
> -# inside a context that will be hoisted in front of the outermost
> -# defun'd macro.  In other words, we must be careful not to warn on:
> +# expanding then requiring a macro is okay, because the dependency was
> +# met, the require phase will be a no-op; the out-of-order expansion
> +# problem is only present if the requirement is nested inside a
> +# context that will be hoisted in front of the outermost defun'd
> +# macro.  In other words, we must be careful not to warn on:
>  #
>  # | m4_defun([TEST4], [4])
>  # | m4_defun([TEST5], [TEST4 REQUIRE([TEST5])])
>  #

This looks fishy to me: a test requiring itself?  Is that what was meant
here?  If yes, then I suggest this case appear in the testsuite, too.

> +# So, to detect whether a require was direct or indirect, m4_provide
> +# stores the diversion number at which a macro was provided.  A
> +# require call is direct if it occurs within the same diversion that
> +# the macro was provided.

Thanks,
Ralf

> --- a/tests/m4sugar.at
> +++ b/tests/m4sugar.at
> @@ -583,6 +583,13 @@ c
>  d
>  post2])dnl
>  outer
> +m4_defun([e], [[e]])dnl
> +m4_defun([f], [[f]m4_require([e])])dnl
> +m4_defun([g], [[g]
> +e
> +f])dnl
> +m4_defun([h], [[h]m4_require([g])])dnl
> +h
>  ]],
>  [[pre1
>  a
[...]