Re: Build issue since version 4.18 using gcc-4.9

[Simon Josefsson]

Thanks for confirming that this solved the problem!

It seems explicit_bzero is patched in gnulib now, so this shouldn't be a
problem going foward, so I'll think about adding a CI/CD build with
-std=c99 to test regressions in this area.  I wonder if -std=c89 works
too...  we have a CI/CD build using 'tcc' instead of 'gcc' so I think it
should work.

However, generally I would recommend against using -std=c99 for building
libtasn1 though, it may pull in unnecessary replacement code from gnulib
to re-implement some -std=gnu99 functionality.  The replacement code may
be more limited than what your system supports.  I didn't verify that
this actually happens, but it is a possibility generally.

/Simon

Vincent Fortier <th0ma7@gmail.com> writes:

> Thnx, the tip paid off, switching to -std=gnu99 solved the issue...
> Help much appreciated!
>
> Cheers!
>
> - vin
>
> Le dim. 27 nov. 2022, à 06 h 13, Simon Josefsson <simon@josefsson.org> a 
> écrit :
>>
>> Vincent Fortier <th0ma7@gmail.com> writes:
>>
>> > While preparing a gnutls update I ended-up updating libtasn1 from
>> > 4.16.  Going to 4.17 works but anything after that fails with:
>>
>> Thanks for the report!  I can reproduce this using:
>>
>> ./configure ac_cv_func_explicit_bzero=no CPPFLAGS="-std=c99"
>>
>> In other words, the problem is due to a combination of a platform
>> without explicit_bzero and forcing GCC into C99 mode where it doesn't
>> support 'asm', so it is not possible to implement 'explicit_bzero'.  Why
>> do you hard code -std=c99?  Try just removing that.  Or use -std=gnu99'
>> to allow GCC to use 'asm'.
>>
>> Analysing further, the 'explicit_bzero' function is only used by
>> 'read_file' in a mode that we never use (for reading sensitive files),
>> so it is never needed by libtasn1.  This is not ideal, but I'm not sure
>> what a maintainable solution is.
>>
>> /Simon
>
>

signature.asc
Description: PGP signature