Re: tcc 0.9.28rc testing: bug in autoconf 2.71 with AC_CHECK_DEFINE

Thanks Nick and Peter for your analysis.

Yes, the "AC_" prefix fooled me, that AC_CHECK_DEFINE belongs to autoconf.


> On 2023-09-23, Nick Bowler <[email protected]> wrote:
> > On 2023-09-23, Detlef Riekenberg <[email protected]> wrote:
> >> AC_CHECK_DEFINE(__unix, CFLAGS="-DFOUND__unix $CFLAGS")
> >> AC_CHECK_DEFINE(__unix__, CFLAGS="-DFOUND__unix__ $CFLAGS")
> >> AC_CHECK_DEFINE(__linux__, CFLAGS="-DFOUND__linux__ $CFLAGS")
> [...]
> > So it sounds like there must be some third party code involved which
> > is defining this macro (and this code is defining macros in the AC_*
> > namespace to make it look like it came from Autoconf when in fact it
> > did not).

I can confirm, that i have the "autoconf-archive" package insalled.
The installed "/usr/share/aclocal/ax_check_define.m4"
contains AC_CHECK_DEFINE and AX_CHECK_DEFINE

> Just to add, you don't need any third party macros to check for typical
> C predefined macros including __unix, etc.  I would write such checks
> something like this (untested):
>
>   AC_COMPUTE_INT([unix_val], [__unix], [@&t@], [unix_val=0])
>   AS_IF([test $unix_val -ne 0],
>     [put code here to run when __unix is defined and is non-zero])

Learned something new. Thanks
The magic "[@&t@]" is really strange.

> Hope that helps,

Sure.
Thanks


--
Regards ... Detlef