Patches for FreeBSD 5.x compilation
sgk at troutmask.apl.washington.edu
Mon Nov 19 22:28:35 CST 2001
On Mon, Nov 19, 2001 at 05:32:16PM -0800, John Alvord wrote:
> On 19 Nov 2001 15:42:18 -0800, Alexandre Julliard
> <julliard at winehq.com> wrote:
> >Steve Kargl <sgk at troutmask.apl.washington.edu> writes:
> >> Can you please explain how this is namespace pollution on the
> >> part of the OS? AFAIK, <sys/user.h> is not specified by any
> >> Standard (ISO C89, C90, or C99). <sys/user.h> can include
> >> any (unprotected) variable name.
> >Yes of course it can, but the fact that this isn't explicitly
> >forbidden by some standard doesn't mean it's good practice or that it
> >doesn't pollute the namespace. sys/user.h is also legally allowed to
> >do "#define if else"; that doesn't make it a good idea.
> >> If an application includes
> >> <sys/user.h>, then the application should be prepared to
> >> deal with conflicts.
> >Great, then you need to fix all applications every time someone feels
> >like exporting a new symbol from user.h. Of course user.h is a pretty
> >obscure header so it's no big deal, but it would be easier to avoid
> >exporting stuff under such common names as "struct thread".
> One way to dodge the name conflicts is to create a separate
> compilation unit, target platform dependent, which does the needed
> work and returns the dynamic information needed. That way it can use
> just the particular platform includes and none of the wine or windows
> includes. The wine code just calls "wine_get_userlen()" and the
> implementing code is target platform dependent.
While it isn't a bad idea to isolate as much machine dependent
code as possible in a few well publicised files, I think you
need to be careful not to get carried away. Wine has done
a fairly good job at this.
What I questioned was the criticism that FreeBSD was guilty
of namespace pollution. Alexandre isn't the only wine
developer who made this statement (check usenet). The header
files in question are implementation dependent and can
contain any variable name or #define or typedef. The fact is
that both wine and FreeBSD have struct thread in implementation
header files. AFAICT, neither is incorrect. But, to have
a wine developer emphatically state that FreeBSD needs to
fix its system header files is somewhat surprising. Why is
it surprising to me? Because this reminds me a company here
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