Re: regression in autoconf-2.62 vs. 2.61

[Stepan Kasal]

Hello Eric,

On Tue, Jun 17, 2008 at 09:20:52PM -0600, Eric Blake wrote:
> | ``
> | Generally speaking, all #define and #undef directives in the header
> | template may be modified by config.status, under some circumstances.
> | Consequently, if you need to define or undefine a symbol under some
> | circumstances (#ifdef THIS #define THAT, etc.), you should place
> | those directives outside the config headers.  If you absolutely need
> | to hook that to the config header itself, please put these directives
> | to a separate file, and #include it from the config header template.
> | (If you are using autoheader, you would probably use AH_TOP or
> | AH_BOTTOM to inject the #include directive.)
> |
> | For certain symbols it is important to avoid #undef ... [explanation
> | about _POSIX_WHATEVER].
> | To achive this, current Autoconf comments out _all_ remaining #undef
> | directives remaining in the config header at the end of the
> | instatiation, but this may change in future releases.
> | ''
> |
> | WDYT?
>
> Looks like a reasonable start, but be careful for typos (such as symbold).
> ~ I'll gladly review a texinfo-markup version, if I don't get around to
> writing one first.

I tried to write something, and I ended up with a different version.
I have also removed a trivial example; IMHO, it does not belong to
this node and I guess the information is available elsewhere in the
manual.

Please find the proposal attached to this mail.  Eric, could you
please merge the two and check for errors?  (Then toss it back to me
or commit.)

Comments from others are very welcome, too, of course.

Have a nice day,
        Stepan

autoconf-undef-doc.patch
Description: Text document