Re: Dump before flag

[Xinliang David Li <davidxl@google.com>]

On Wed, Jun 1, 2011 at 2:12 PM, Basile Starynkevitch
<basile@starynkevitch.net> wrote:
> On Wed, 1 Jun 2011 13:26:24 -0700
> Xinliang David Li <davidxl@google.com> wrote:
>
>> Hi, this is a simple patch that support dump_before flag. E.g,
>>
>> -fdump-tree-pre-before
>>
>> This is useful for diffing the the IR before and after a pass.
>
> Perhaps you forgot to actually attach the patch?

Right -- attached in a follow up email.
>
>> Gcc dumping needs more cleanups -- such as allowing IR only dump,
>> allowing IR dumping for a particular function etc. The exposure of
>> 'dumpfile' (instead of a dumping_level () function) makes those change
>> a little messy, but can be done.
>
> I don't understand what you mean by a dumping_level () function. What
> should that hypothetical function do? (I'm wrongly guessing it would
> return an integer, but IIRC dumpfile is a FILE*)

THere are two sources of dump:

1) IR dump performed by pass manager
2) pass specific debugging dump (the verbosity is controlled by -details flag).

2) is the part that is messy and needs cleanup. Every pass just checks
if dump_file is null or not and decide to dump the debugging info --
there is no easy way to turn it on and off. Ideally, individual pass
should call

  int debug_dump_level () -- dumps when it returns > 0.

With that in place, the dump flag -fdump-xxx-yyy-ir_only can be easily
implemented -- it only turns on pass manager dump, but lowers the
debug dump level to 0.

David


>
> Regards
>
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> Basile STARYNKEVITCH         http://starynkevitch.net/Basile/
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