Re: Add <stdint.h> integer width macros

[Florian Weimer <fweimer at redhat dot com>]

On 03/05/2017 10:50 AM, Ovidiu M wrote:
> Hi Joseph,
>
> The new macro SIZE_WIDTH conflicts with a definition in one of my
> projects, breaking compilation (
> https://gitlab.com/o9000/tint2/issues/625 ) with gcc 7 (which IIUC is
> a pre-release version).

Removing _GNU_SOURCE is a workaround which will address many such issues.

> Could you please tell me if there is anything I can do about it, other
> than renaming that variable?

You can participate in glibc development.  Current consensus here is 
that _GNU_SOURCE should be adjusted in every release to reflect a 
superset of all standards supported by glibc (where those standards do 
not conflict).  This does have its problems, and particularly reckless 
ISO revisions might force the community to adopt.

Another option is to participate in the ISO standardization process and 
explain to these people that new identifiers added to existing header 
files should use some construct (such as a suitable prefix) to reduce 
the risk of collisions.  Or perhaps non-core standards should stop 
patching existing header files altogether and add new ones, which would 
also resolve the backwards compatibility issue.

At some point in the future, it is likely that switching to C++ will 
also reduce such issues because C++ relies less heavily on macros, and 
identifiers can be nested in namespaces.  At present, this is not really 
an option because the GNU C++ implementation (via libstdc++) relies on 
_GNU_SOURCE.

Thanks,
Florian