llvm dev - Dec 2019 - Adding custom callback function before/after passes

Hello all,

Is there a way to register callback that runs before/after passes?
PassTimingInfo seems to do a similar thing by calling
PassInstrumentationCallbacks::registerBeforePassCallback /
registerAfterPassCallback, but it is hard-wired with
StandardInstrumentations class.
Do we have something similar to RegisterStandardPasses, so custom callbacks
can be added from somewhere outside LLVM?

Thanks,
Juneyoung Lee
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20191204/1a07f148/attachment.html>

If you are using the legacy PassManager and control when the PassManager is
created, you can do this with a little hack like:

struct MyPassManager final : llvm::legacy::PassManager
{
        void add(llvm::Pass* const pass) override
        {
            // Add your own pass which does a before callback
            llvm::legacy::PassManager::add(your_start_pass(pass));

            // Add the originally requested pass
            llvm::legacy::PassManager::add(pass);

            // Add your own pass which does an after callback
            llvm::legacy::PassManager::add(your_end_pass(pass));
        }
} passManager; // add new passes to this pass manager!

I've used this hack in the past (it is also something similar to how opt
lets you bail out on a certain pass).

Cheers,
-Neil.

On Tue, Dec 3, 2019 at 5:02 PM Juneyoung Lee via llvm-dev <
llvm-dev at lists.llvm.org> wrote:
> Hello all,
>
> Is there a way to register callback that runs before/after passes?
> PassTimingInfo seems to do a similar thing by calling
> PassInstrumentationCallbacks::registerBeforePassCallback /
> registerAfterPassCallback, but it is hard-wired with
> StandardInstrumentations class.
> Do we have something similar to RegisterStandardPasses, so custom
> callbacks can be added from somewhere outside LLVM?
>
> Thanks,
> Juneyoung Lee
>
>
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>

-- 
Neil Henning
Senior Software Engineer Compiler
unity.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20191203/8fa90895/attachment.html>

On 12/3/19 8:01 PM, Juneyoung Lee via llvm-dev wrote:
> Hello all,
>
> Is there a way to register callback that runs before/after passes?
> PassTimingInfo seems to do a similar thing by calling 
> PassInstrumentationCallbacks::registerBeforePassCallback / 
> registerAfterPassCallback, but it is hard-wired with 
> StandardInstrumentations class.
PassInstrumentation framework was introduced to the new PassManager 
specifically in mind with ability
to register arbitrary callbacks and execute them as pass manager 
traverses through the pass pipeline.

PassInstrumentationCallbacks are indeed the entity to register your 
callbacks into, before passing it to PassBuilder;
You can check how it is being done in 
`llvm/tools/opt/NewPMDriver.cpp`llvm::runPassPipeline.

StandardInstrumentations are just a few "standard" callbacks that 
provide "standard" functionality, like -print-after-all or
-time-passes.
StandardInstrumentations registers its individual instrumentations the 
same way you would register your own.

Note, that PassInstrumentation is only supported in new pass manager 
(opt -passes=  or clang -fexperimental-new-pass-manager).

regards,
   Fedor.
> Do we have something similar to RegisterStandardPasses, so custom 
> callbacks can be added from somewhere outside LLVM?
>
> Thanks,
> Juneyoung Lee
>
>
>
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20191211/51f9675d/attachment.html>

Hello Fedor.

Thank you for the information.
I made a simple patch that exposes PassInstrumentationCallback so
llvmGetPassPluginInfo can use it: https://reviews.llvm.org/D71086 . Would
this change make sense?

Thanks,
Juneyoung Lee

On Thu, Dec 12, 2019 at 12:44 AM Fedor Sergeev <fedor.sergeev at azul.com>
wrote:
>
>
> On 12/3/19 8:01 PM, Juneyoung Lee via llvm-dev wrote:
>
> Hello all,
>
> Is there a way to register callback that runs before/after passes?
> PassTimingInfo seems to do a similar thing by calling
> PassInstrumentationCallbacks::registerBeforePassCallback /
> registerAfterPassCallback, but it is hard-wired with
> StandardInstrumentations class.
>
> PassInstrumentation framework was introduced to the new PassManager
> specifically in mind with ability
> to register arbitrary callbacks and execute them as pass manager traverses
> through the pass pipeline.
>
> PassInstrumentationCallbacks are indeed the entity to register your
> callbacks into, before passing it to PassBuilder;
> You can check how it is being done in
> `llvm/tools/opt/NewPMDriver.cpp`llvm::runPassPipeline.
>
> StandardInstrumentations are just a few "standard" callbacks that
provide
> "standard" functionality, like -print-after-all or -time-passes.
> StandardInstrumentations registers its individual instrumentations the
> same way you would register your own.
>
> Note, that PassInstrumentation is only supported in new pass manager (opt
> -passes=  or clang -fexperimental-new-pass-manager).
>
> regards,
>   Fedor.
>
>
> Do we have something similar to RegisterStandardPasses, so custom
> callbacks can be added from somewhere outside LLVM?
>
> Thanks,
> Juneyoung Lee
>
>
>
> _______________________________________________
> LLVM Developers mailing listllvm-dev at
lists.llvm.orghttps://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>
>
>
-- 

Juneyoung Lee
Software Foundation Lab, Seoul National University
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20191212/49c29d79/attachment.html>