Re: Can we drop upstream Linux x32 support?

Rich Felker
2018-12-14T16:55:47Z

On Fri, Dec 14, 2018 at 05:38:33PM +0100, Florian Weimer wrote:
> * Rich Felker:
>
> > This is all useless (and wrong since tv_nsec is required to have type
> > long as part of C and POSIX, regardless of ILP32-vs-LP64; that's a bug
> > in glibc's x32).
>
> We should be able to fix standards if they prove unworkable in practice.
> In my opinion, if standards require complex solutions where an obvious
> and simple solution exists, then standards are wrong.

The requirement doesn't mandate complex solutions. There's nothing
complex about tv_nsec being long. long is the smallest type that C
guarantees to be large enough to store the range of values, which is
forever fixed and can't grow (because the definition of "nano" prefix
is fixed :). The type has been long ever since the structure was
introduced, and its being long means that there's lots of (correct!)
code using %ld (e.g. ".%.9ld" to format results as a decimal without
using floating point approximations) to print it. There might also be
code taking pointers to it to pass to functions, etc.

The only reason a "complex" need arises is that Linux did something
horribly wrong here, ignoring the specified type, when introducing an
obscure subarch that almost nobody uses. This kind of mistake is
becoming a theme in Linux (see also: msghdr). Application authors
should not have to pay the price for fixing this by retrofitting yet
another silly type like "snseconds_t" or something into programs to
accommodate the mistakes of x32.

Rich