Re: z/OS and libc

Karl Williamson wrote:
> I'm working on continuing to port perl5 to z/OS.  One test that is 
> failing is beyond my knowledge level.  The Dynaloader module has a 
> function dl_findfile() which looks for libraries in the path.  It is 
> expecting to find libc at least, but is finding nothing.
> 
> This test does not work on several platforms, even some Unix-like ones, 
> and my guess is it doesn't work on z/OS either.  But I am hoping someone 
> can give me more information.
> 
> One of the comments in the perl source says:
>     # On OS/390, libc.a doesn't really hold anything at all,
>     
> And that makes me think that looking for it (and perhaps any Unix-y 
> library) is futile.

Verify that accuracy of that comment. Use nm to dump all the c symbols 
in libc.a. Does libc.a look like libc or not?

Config.pm and Configure have a "libc" var that is set through some logic 
in Configure.

Porting/Glossary says
----------------------------------------------------------
libc (libc.U):
	This variable contains the location of the C library.
----------------------------------------------------------

I would guess one purpose of that config var is automatically look for c 
symbols with nm if you aren't doing test compiles. I'll point out 
t/porting/libperl.t exists.