[parisc-linux] Breaking PARISC ABI - Testing procedures?

[Carlos O'Donell <carlos@baldric.uwo.ca>]

debian-gcc,

I sense another PARISC ABI breakage coming in the very near
future. The ABI breakage is caused by the following three
items:

1- setjmp/longjmp implementation is flawed (Testing)
2- mcontext_t is incorrect in glibc (BTS #157374)
3- sizeof(long double) is incorrect in gcc and glibc (?)

My main question is:

How does one run a preliminary test to ferret out
possibly problems that were not forseen?

My current procedure is to build a new glibc, create
a chroot, install glibc there and begin building things.

Does anyone have a general procedure for this? Or is
this what experimental or unstable is about? :/  

---

I'm working on providing various test cases for "1-" and 
I already have a patch in my local glibc tree (the initial
patch made the mistake of not allocating enough room for
jmpbuf - kudos to Randolph for noticing that during RFC).

I have a patch for "2-" and it works, but we have a kernel
bug when copying registers into the sigcontext that gets
passed back to a 32-bit userspace from a 64-bit kernel.
Luckily the old definition of mcontect_t matches the new
sigcontext typedef for accesses to general registers and
floating point registers, so we maintain backwards compat
in that scenario. I would like to note that it has never
worked when running a 64-bit kernel under parisc :}

The last issue will get fixed when I get around to poking
changes at gcc.

c.