Re: [patch][plugins] Provide unique names to all compiler passes

[Joern Rennecke <amylaar at spamcop dot net>]

Zbigniew Chamski:
> plugins refer to passes by their name, hence all compiler passes need
> a unique name:
>
>     * passes with NULL name should get a new unique name;
>     * passes which had duplicate names should be disambiguated by
> changing at least one name to achieve uniqueness.

I have updated the patch to the current trunk.
It needed an extra change in passes.c:make_pass_instance to avoid
changing static_pass_number for the non-dumped passes, lest one would end
up with a static_pass_number of -2.

Diego Novillo:
> Additionally, the pass manager should assert that every
> registered pass has a name.  This can be done in next_pass_1.
>
> OK with that change.

I have added that.

Paolo Bonzini:
> The pass name should also be prefixed by * to avoid creating dump  
> files uselessly.

And that too.

This exposed a problem with the patch: the renaming of passes changes
the dump file names and options.  The -fdump-postreload option was
suddenly missing.

To rectify this, I have backed out the name changes where there was no
actual pass name conflict, and where an actual name clash had to be
resolved, I have used a prefix followed with ASCII STX, which a bit of
new code in register_one_dump_file skips, so that the old dump file and
option names continue to be used.

There might be a case to disambiguate some dump options, but I don't want
to bundle such user interface changes and the test suite changes that would
then be required with the plugin prerequisites.

Regression tested in trunk revision 153936 on i686-pc-linux-gnu .

Attachment: unique-pass-names.patch-20091105-2
Description: Text document