Running GCC tests on installed compiler

[Steve Ellcey <sje at cup dot hp dot com>]

Can someone one with some deja-knowledge help me figure out how to run
the GCC tests on an installed compiler and without having to do a GCC
build?

I started with 
  runtest -tool gcc --srcdir /proj/opensrc/nightly/src/trunk/gcc/testsuite

and that ran the tests, but it ran them with whatever gcc command it
found in PATH.  I tried setting and exporting CC before running runtest
and putting "CC=...."  on the runtest command line but neither of those
methods seemed to affect what gcc was run by runtest.

So then I tried to create a site.exp file and use that on the command
line, in site.exp I put:

  set CC "/proj/opensrc/be/ia64-hp-hpux11.23/bin/gcc"
  set srcdir "/proj/opensrc/nightly/src/trunk/gcc/testsuite"

I also tried using the site.exp file that I got from building GCC and
various combinations of the two but all these attempts ended with no
tests runs and the following lines in my log file:

  Running target unix
  Using /proj/opensrc/be/ia64-debian-linux-gnu/share/dejagnu/baseboards/unix.exp as board description file for target.
  Using /proj/opensrc/be/ia64-debian-linux-gnu/share/dejagnu/config/unix.exp as generic interface file for target.
  WARNING: Couldn't find tool config file for unix, using default.

When testing my just built GCC I was seeing:

  Running target unix
  Using /proj/opensrc/be/ia64-debian-linux-gnu/share/dejagnu/baseboards/unix.exp as board description file for target.
  Using /proj/opensrc/be/ia64-debian-linux-gnu/share/dejagnu/config/unix.exp as generic interface file for target.
  Using /proj/opensrc/nightly/src/trunk/gcc/testsuite/config/default.exp as tool-and-target-specific interface file.
  Running /proj/opensrc/nightly/src/trunk/gcc/testsuite/gcc.c-torture/compile/compile.exp ...

The built GCC seems to be picking up an extra .exp file (default.exp) but
I am not sure why or how to fix it so that my non-built compiler runs the
same way.  Can someone help me out here?

Steve Ellcey
sje@cup.hp.com