Subject: Re: bug#20567: guile 2.0.11 - test failures on mips64 big-endian with n32 ABI

From: Andy Wingo <[email-masked]>
Date: Fri, 24 Jun 2016 07:17:50 +0200

Mark does this ring a bell to you?  I know you have a mip64 n32 machine
that you use sometimes.

Andy

On Wed 13 May 2015 20:31, "Schaefer, Frank" <[email-masked]> writes:

> I've encountered two test failures with guile 2.0.11 on mips64
> big-endian, whenever I build with -mabi=n32 (these test failures do
> not occur with -mabi=64).  At least one of them I have resolved with
> the attached patch.
>
> First testcase failure: test-ffi (fixed by my patch).  The guile code
> apparently assumes that sizeof(ffi_arg)<=sizeof(void **).  This is a
> faulty assumption; it holds on *most* platforms, but with the mips64
> n32 ABI, sizeof(void **)==4, and sizeof(ffi_arg)==8.  So every foreign
> function that returns a pointer is liable to corrupt data, and anyone
> retrieving the return value as a simple void * is only going to get
> sign-extension garbage on big-endian (usually NULL).
>
> Second testcase failure: check-guile fails due to 'ERROR:
> foreign.test: procedure->pointer: qsort - arguments:
> ((null-pointer-error "pointer->bytevector" "null pointer dereference"
> () ()))'.  I strongly suspect it's related to the ffi_arg issue
> mentioned above, but I'm still peeling away macro ugliness to track it
> down.  If anyone wants to pitch in with additional guidance or
> patchwork, I'd be happy to listen and test.
>
> (The patch applies against 2.0.11 release or against current HEAD,
> where it also fixes the new testcases for test-foreign-object-scm and
> test-foreign-object-c.  HEAD also fails the test-out-of-memory case,
> though, which precludes further unit tests.)