Re: [PATCH v2 2/7] y2038: Introduce __ASSUME_64BIT_TIME define

[Joseph Myers <joseph@codesourcery.com>]

On Wed, 8 May 2019, Stepan Golosunov wrote:

> You need to handle the following 4 cases:

And, to be clear:

These cases are ones to think about when writing a patch in this area.

They are not cases that should be enumerated in comments in the code for 
any particular function, because they are completely standard for how 
these syscalls are handled across all such functions and comments in a 
function should be about things specific to that particular function - we 
don't want repetitive comments that all describe the same generic things.  
Most of this is also generic to *any* case in glibc where we have optional 
support for using a new syscall, with fallback code when the syscall can't 
be assumed to be supported.

If those general rules about optional support for new syscalls are to be 
documented anywhere in glibc, I think maint.texi would be the right place 
for such documentation.

If some function has a good reason for *not* following the generic pattern 
you described, *that* would be a case for having a comment in the function 
explaining why it's not implemented in the normal way.

-- 
Joseph S. Myers
joseph@codesourcery.com