Re: [PATCH 4/6] Handwritten part of conversion of passes to instances of C++ classes

[David Malcolm <dmalcolm at redhat dot com>]

On Fri, 2013-04-19 at 21:23 -0400, David Malcolm wrote:
> 	This is the hand-written part of the patch; it is required for the
> 	preceding auto-generated patch to make sense.

[Answering my own patch]

This patch isn't yet good enough as-is: upon investigating test case
failures I found that the patch wasn't properly handling instances of
passes, leading to the symptom of:
  cc1plus: error: unrecognized command line option '-fdump-tree-fre1'
which was because both of the instances of "fre" were erroneously
getting the dump switch '-fdump-tree-fre' (i.e. missing the trailing
instance number).

This highlighted a deeper issue with converting the passes to C++
classes: register_pass expects a pre-allocated pass, but potentially
needs to create multiple copies of the pass if it's going to be inserted
in multiple places, and gcc/passes.c:make_pass_instance creates these
instances using a memcpy with a fixed size (based on the pass type).  If
we're going to support hanging extra data off of a pass instance, it
means a small reorganization here.

I'm working on a revised patch series which respects the status quo as
per -fdump- option names, and which changes register_pass so that you
pass in a callback for creating passes, rather than creating the pass
yourself.

Dave