Re: Designs for better debug info in GCC

[Ian Lance Taylor <iant@google.com>]

Alexandre Oliva <aoliva@redhat.com> writes:

> > And it will avoid the problem of turning the testsuite into a
> > regression testsuite rather than an accuracy testsuite.
> 
> Sorry, I don't understand what you mean here.

It's not a major point.

When one adds a testsuite to working code, it is natural to write
tests that expect to see what the code generates.  The risk is that
any change to the code causes the test to fail.  This is the essence
of a regression testsuite.  For an example, see the linker testsuite
in the binutils.  Practically any change to the linker, correct or
not, causes some tests to fail.

An accuracy testsuite is one written independently of the code.  It
tests for the specific features that are desired, rather than testing
for what the code currently does.

Of course you can write an accuracy testsuite with working code.  It's
just much easier to write a regression testsuite, and it's easy to
backslide into that.

Ian