[PATCH v3 2/4] libio: Remove the usage of __libc_IO_vtables

[Adhemerval Zanella Netto]

On 06/03/23 14:24, Adhemerval Zanella Netto wrote:
> 
> 
> On 06/03/23 13:53, Andreas Schwab wrote:
>> On Mär 06 2023, Adhemerval Zanella Netto wrote:
>>
>>> So could be an issue with my patch then? I did not added any new
>>> dependency or rule with this patchset.
>>
>> The new dependency is gen-as-const-headers.
>>
>> I think it adds a cycle because libio-macros.h depends on
>> $(common-objpfx)bits/stdio_lim.h, whereas other gen-as-const-headers
>> don't depend on it.
> 
> Right, do we really have to autogenerate stdio_lim.h? It seems that no 
> target currently requires to the overrides its values.  It would be way 
> simpler if we can assume the sysdeps/posix/Makefile values instead.

Alright, I could reproduce it and I am not sure how to fix it.  This fix
requires libio-macros.sym to correctly setup _IO_file_jumps and 
_IO_wfile_jumps alias symbol, and the libio/libio-macros.sym requires to 
know the size ofstruct _IO_jump_t (which in turn uses function pointer 
that uses FILE *).

So libio-macros.sym does require stdio_lim.h in the end.  Best solution
I can think of is to just remove stdio_lim.h autogeneration, the only
real system dependent definition is FILENAME_MAX, obtained from kernel
limits.h.  I think it should be feasible to just define is a 1024 for
hurd and 4096 for Linux (these should not change in near future and
change it might incur in some compatibility issues).