Hi Charlotte,

On 9/19/21 2:07 AM, Charlotte Delenk wrote:
> The _auto_-macro used in cert.c and tls.c uses a GCC extension that
> allows for nested functions. This is not supported by other compilers,
> including clang.
> 
> Compiling ell with these compilers will result error messages such as:
> 
> ../ell-0.44/ell/tls.c:1895:2: error: function definition is not allowed here
>          _auto_(l_certchain_free) struct l_certchain *certchain = NULL;
>          ^
> ../ell-0.44/ell/useful.h:71:2: note: expanded from macro '_auto_'
>          _AUTODESTRUCT(__COUNTER__, func)
>          ^
> ../ell-0.44/ell/useful.h:68:2: note: expanded from macro '_AUTODESTRUCT'
>          __AUTODESTRUCT(var, func)
>          ^
> ../ell-0.44/ell/useful.h:64:2: note: expanded from macro '__AUTODESTRUCT'
>          { func(*(void **) ptr); }                       \
>          ^
> ../ell-0.44/ell/tls.c:1895:2: error: use of undeclared identifier 'cleanup_0'
> ../ell-0.44/ell/useful.h:71:2: note: expanded from macro '_auto_'
>          _AUTODESTRUCT(__COUNTER__, func)
>          ^
> ../ell-0.44/ell/useful.h:68:2: note: expanded from macro '_AUTODESTRUCT'
>          __AUTODESTRUCT(var, func)
>          ^
> ../ell-0.44/ell/useful.h:65:23: note: expanded from macro '__AUTODESTRUCT'
>          __attribute((cleanup(cleanup_ ## var)))
>                               ^
> 
> This patch will removes the _auto_ macro and implement its functionality
> manually in the two locations it is used.

The problem is that we like the _auto_ macro ;)  And getting rid of it in iwd 
isn't as easy.

> 
> It does not appear to be possible to replace this macro with a more
> compatible alternative that does not involve C++.
>

So what about doing something like this (attached).  This approach is a bit less 
flexible than our current version since we have to declare extra destructors, 
but maybe clang doesn't hate it?

> Signed-off-by: Charlotte Delenk <darkkirb(a)darkkirb.de>

Just FYI, we do not use S-o-b tags here.

> ---
>   ell/cert.c   |  6 +++++-
>   ell/tls.c    |  6 +++++-
>   ell/useful.h | 11 -----------
>   3 files changed, 10 insertions(+), 13 deletions(-)
> 

Regards,
-Denis