Fix GHC ticket 2615 (linker scripts in .so files)

[Howard B. Golden]

Hi Simon M.,

On Wednesday December 2, 2009, I wrote:

> I'm not sure how to write a test case that can be added to the
> validation tests. By _hand_ I have been testing by running:
> 
> $ ghc-stage2 --interactive -lpcre
> 
> On my system (Gentoo), /usr/lib64/libpcre.so is a linker script.
> However, I don't think this will always be true on other systems. I'd
> appreciate some suggestions about how to write the test.

I thought of this approach: In the test I will create a linker script 
and point it to some convenient library (e.g., libc.so). Then I'll load 
it.

For example, if libc is /lib64/libc.so.6, I will create a linker script 
in <test_directory>/testc.so which contains GROUP ( /lib64/libc.so.6 ). 
Then I'll execute:

  ./ghc-stage2 --interactive <test_directory>/testc.so

Note: <test_directory> must be an absolute path; relative paths don't 
work here.

This should succeed with the following messages:

GHCi, version 6.12.0.20091126: http://www.haskell.org/ghc/  :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
Loading package ffi-1.0 ... linking ... done.
Loading object (dynamic) <test_directory>/testc.so ... done
final link ... done
Prelude>

Please let me know if this is an acceptable test case or give your 
feedback. Thanks.

Howard