[New PM] Introducing PassInstrumentation framework

[fedor.sergeev]

Summary

Pass Execution Instrumentation interface enables customizable instrumentation
of pass execution, as per "RFC: Pass Execution Instrumentation interface"
posted 06/07/2018 on llvm-dev@

The intent is to provide a common machinery to implement all
the pass-execution-debugging features like print-before/after,
opt-bisect, time-passes etc.

Here we get a basic implementation consisting of:

• PassInstrumentationCallbacks class that handles registration of callbacks and access to them.

• PassInstrumentation class that handles instrumentation-point interfaces that call into PassInstrumentationCallbacks.

• Callbacks accept StringRef which is just a name of the Pass right now. There were some ideas to pass an opaque wrapper for the pointer to pass instance, however it appears that pointer does not actually identify the instance (adaptors and managers might have the same address with the pass they govern). Hence it was decided to go simple for now and then later decide on what the proper mental model of identifying a "pass in a phase of pipeline" is.

• Callbacks accept llvm::Any serving as a wrapper for const IRUnit*, to remove direct dependencies on different IRUnits (e.g. Analyses).

• PassInstrumentationAnalysis analysis is explicitly requested from PassManager through usual AnalysisManager::getResult. All pass managers were updated to run that to get PassInstrumentation object for instrumentation calls.

• Using tuples/index_sequence getAnalysisResult helper to extract generic AnalysisManager's extra args out of a generic PassManager's extra args. This is the only way I was able to explicitly run getResult for PassInstrumentationAnalysis out of a generic code like PassManager::run or RepeatedPass::run.

• PassBuilder takes PassInstrumentationCallbacks object to pass it further into PassInstrumentationAnalysis. Callbacks registration should be performed directly through PassInstrumentationCallbacks.

• new-pm tests updated to account for PassInstrumentationAnalysis being run

• Added PassInstrumentation tests to PassBuilderCallbacks unit tests. Other unit tests updated with registration of the now-required PassInstrumentationAnalysis.

[fedor.sergeev]

Will add more comments! :)

include/llvm/IR/PassInstrumentation.h

44

Nope, this is left over from some previous version.

[fedor.sergeev]

adding comments

[philip.pfaffe]

Back from vacation, and had time for a closer look.

My major concern right now is ownership. In your current state, PassBuilder owns both all the callbacks as well as the state of the instrumentation (i.e., the counter). As it were, PassBuilder is in fact more of a transient factory that you can throw a way after you've set up your pipeline. Or you might even use it to make more than one pipeline. In both cases ownership is a problem.

Instead, I believe it makes for nicer separation if PassBuilder becomes purely the entry point for callback registration, and all bookkeeping happens within the pipeline. IMO, a good place to put this would be the Module-level Analysis itself, which is a singleton wrt. a single compilation. Federation between different IRUnits can happen via proxies, which adds some amount of indirections, but I still think that's manageable.

Lastly, I think this deserves unittests. You can check out PassBuilderCallbacksTests or LoopPassManagerTests for inspiration on how to mock out passes and analyses. This might also be a perfect moment to nudge @chandlerc in the direction of D39678 to simplify this :)

[fedor.sergeev]

In D47858#1217605, @philip.pfaffe wrote:

Back from vacation, and had time for a closer look.

My major concern right now is ownership.

Yes, this is one of the main concerns for me as well.

In your current state, PassBuilder owns both all the callbacks as well as the state of the instrumentation (i.e., the counter). As it were, PassBuilder is in fact more of a transient factory that you can throw a way after you've set up your pipeline. Or you might even use it to make more than one pipeline. In both cases ownership is a problem.

This is exactly when submitting my RFC I was going to use LLVMContext for this ownership.
Some of replies (including yours ;) - http://lists.llvm.org/pipermail/llvm-dev/2018-June/123850.html) were in favor of PassBuilder.
PassBuilder is not ideal for my own downstream project either - we do not keep PassBuilder around.
But then we need to find something else that owns.

Instead, I believe it makes for nicer separation if PassBuilder becomes purely the entry point for callback registration, and all bookkeeping happens within the pipeline. IMO, a good place to put this would be the Module-level Analysis itself, which is a singleton wrt. a single compilation.

Ehm... let me try this. When I quick-checked it last time I did not like amount of changes I need to do for that. But it is doable and I'm definitely more familiar with codebase as of right now.

Federation between different IRUnits can happen via proxies, which adds some amount of indirections, but I still think that's manageable.

I'm not particularly happy with all these PassInstrumentationAnalysis runs, for one because it makes updating all the new-pass-manager tests that use -debug-pass-manger quite a churn. :)

Lastly, I think this deserves unittests. You can check out PassBuilderCallbacksTests or LoopPassManagerTests for inspiration on how to mock out passes and analyses.

Definitely. I just had no experience with llvm unit-tests before that, so I decided to postpone doing them until after we settle on main design points.

[fedor.sergeev]

One additional implication on design that I just realized:

-pass-times functionality effectively requires to differentiate between distinct Pass instances, separately tracking times for different instances of the same "pass type".
That in turn requires passing some unique identifier for the pass instance, not just for the pass type as I was doing before.

And that means there should be extra parameter to all the pass callbacks taking either pointer to pass (void*???) or some encoded version of that (unique string etc).
Perhaps it should be part of PassExecutionCounter (which actually becomes PassExecutionID and include both "execution counter" and "pass instance ID").

[philip.pfaffe]

IMO passing void* as an opaque ID along with the name is fine. Passing the PassConcept by reference would degrade layering, since it lives in IR, not in Passes like the rest of this. could be a viable alternative, the Passes library depends on IR anyways.

Edit: Although it's doable, I again don't like handing out access to the pass in order to prevent clients from running the pass themselves.

[philip.pfaffe]

Reconsidering passing the actual IRUnit to the callbacks, I still think that's not a good idea. Downstream users _will_ eventually use this to hook into the pipeline and mess with the IR somehow. So instead this should be opaque to clients.

What operations do clients ever have to perform on an IRUnit? The number should be tiny I believe.

I'd love to see something like a generic IRUnit wrapper, that implements these operations plus some opaque IRUnit id. Currently that'd just be print. Passing the wrapper to the callback then is safe, and it allows clients to both identify the ir object as well as do what we allow them to do with the object.

[fedor.sergeev]

In D47858#1221946, @philip.pfaffe wrote:

Reconsidering passing the actual IRUnit to the callbacks, I still think that's not a good idea. Downstream users _will_ eventually use this to hook into the pipeline and mess with the IR somehow. So instead this should be opaque to clients.

I dont fully get your concerns.
By analogy - downstream users can use their own Analyses to mess with IR. But we do not have any kind of protection against that.
Does it worry you the same way?

What operations do clients ever have to perform on an IRUnit? The number should be tiny I believe.
I'd love to see something like a generic IRUnit wrapper, that implements these operations plus some opaque IRUnit id. Currently that'd just be print.

Printing is the first user, yes.
Any kind of inspection for debug purposes (like putting IR into database).

Passing the wrapper to the callback then is safe, and it allows clients to both identify the ir object as well as do what we allow them to do with the object.

One of the problems with generic IRUnit wrapper is that it is not easily extensible.
A prime idea of pass instrumentation is to provide an easily extensible pass-pipeline observability tool.
I would not like to harm extensibility of this tool for the sake of protecting users against foot-shooting themselves.

[fedor.sergeev]

In D47858#1221946, @philip.pfaffe wrote:

What operations do clients ever have to perform on an IRUnit? The number should be tiny I believe.

Looking at the original RFC I see:

-print-after
-verify-each

plus ideas like:

-git-commit-after-all
-debugify-each

By a pure accident I left out the IRUnit parameter in the first version of RFC but did correct myself soon as after.
I was under impression that suggested non-opaque nature of IRUnit is kinda clear during the discussion that followed
(though nobody was specifically picking on it pro- or contra-).

[fedor.sergeev]

In D47858#1221932, @philip.pfaffe wrote:

IMO passing void* as an opaque ID along with the name is fine. Passing the PassConcept by reference would degrade layering, since it lives in IR, not in Passes like the rest of this. could be a viable alternative, the Passes library depends on IR anyways.

Yes, idea is to use void* of the PassConcept as an opaque ID.
Actually I plan to hide it under struct PassInstanceID, and its implementation can choose other ways of hiding this (e.g using unique string or whatnot).

[philip.pfaffe]

Okay, that sounds reasonable.

[fedor.sergeev]

In D47858#1222265, @philip.pfaffe wrote:

Okay, that sounds reasonable.

Eh... perhps I was too chatty here...
Can you confirm what among my mumblings appeared reasonable to you, all of it? :)

[philip.pfaffe]

Sorry :)

I meant both your arguments towards passing the real IRUnit and an opaque pass identifier.

[philip.pfaffe]

include/llvm/IR/PassManager.h

778

Are you ever actually calling this, except through the indirection above?

[fedor.sergeev]

include/llvm/IR/PassManager.h

778

Any suggestions on how to simplify it?
This unpacker thing is the only way I figured to get Ns == sizeof(ExtraArgTs) and not sizeof(ArgTs).

[philip.pfaffe]

include/llvm/IR/PassManager.h

778

You can do Ns == sizeof...(ExtraArgTs), but you're not actually using that here?

[fedor.sergeev]

include/llvm/IR/PassManager.h

778

This is exactly a purpose of these two getPassInstrumentation methods that take tuple.
See in PassManager::run() :

PassInstrumentation<IRUnitT> PI =
    AM.getPassInstrumentation(IR, std::tuple<ExtraArgTs...>(ExtraArgs...));

Here ExtraArgTs are PassManager's ExtraArgTs and they do not match AnalysisManager's ExtraArgTs.
I need to take PassManager's ExtraArgs, deduce AnalysisManager's ExtraArgTs (different ones) from AM parameter.
This deduction is what first helper is for.
And then it calls a second helper that takes first N arguments from tuple.

[philip.pfaffe]

include/llvm/IR/PassManager.h

778

Right! Looks like i missed the difference between ArgTs and ExtraArgTs.

[fedor.sergeev]

In this update:

• PassInstanceID introduced to track pass instances
• IRUnits are const references to avoid mishaps in instrumentation callbacks
• some comments added/updated

[fedor.sergeev]

switching to simpler PassInstanceID constructors - overload instead of sfinae

[fedor.sergeev]

deleting a minor stray change that belongs elsewhere

[philip.pfaffe]

Here's what I think the ownership layering should look like:

struct PassInstrumentationProxy : AnalysisInfoMixin<> {                         
  using Result = PassInstrumentation *;                                         
                                                                                
  Restul run(...) { return AM->PI; }                                            
};

struct PassBuilder {                                                            
  PassInstrumentation *PI = nullptr;               
  PassBuilder(PassInstrumentation *PI = nullptr) : PI(PI) {}
                                                                                
  void addCallback(...);                                                        
                                                                                
  void registerFunctionAnalyses(ModuleAnalysisManager &MAM) {                   
    MAM.addPass(PassInstrumentationProxy(PI));
    ...                                                                         
  }                           
};                                                                              
                                                                                
struct PassInstrumentation {                                                    
  // Callbacks                                                                  
  SmallVector<std::function<BeforePassFunc>, 4> BeforePassCallbacks;            
  SmallVector<std::function<AfterPassFunc>, 4> AfterPassCallbacks;              
  SmallVector<std::function<void()>, 2> StartPipelineCallbacks;                 
  SmallVector<std::function<void()>, 2> EndPipelineCallbacks;                   
                                                                                
  // Instrumentation payload                                                    
  unsigned PassExecutionCounter;                                                
};

PassBuilder becomes purely the callback registration entrypoint. When populating any AM, all the callbacks get passed down into it. Passes and passmanagers access the payload through a proxy analysis.

Edit: Incorporated some suggestions by Chandler.

[fedor.sergeev]

Ok, to summarize what I'm going to change:

• drop the pimpl proxy in PassInstrumentation/PassInstrumentationImpl
• make it a single class, no templates
• ownership outside of PassBuilder/PassManager
• pass to PassBuilder, non-owning reference, registration through PassBuilder
• modify RepeatedPass::run to make it easier to use getResult
• getResult returns pointer to PassInstrumentation

[fedor.sergeev]

PassInstrumentation handling simplified - now it is just a single class,
Ownership is not managed by PassBuilder anymore.
A bit of renaming (e.g. PassInstrumentationAnalysis -> PassInstrumentationProxy).

[philip.pfaffe]

I like how simple this is now!

include/llvm/IR/PassInstrumentation.h

200

Is mutable necessary now?

include/llvm/IR/PassManager.h

946

Empty line?

1235

No need to make this a template class! Since PassInstrumentation isn't, anymore, this doesn't need to be either.

include/llvm/Passes/PassBuilder.h

568

I don't think this should assert. This can be called from a plugin context, and the plugin has no chance of knowing whether PassInstrumentation is available. So in that case, just do nothing I guess.

[fedor.sergeev]

include/llvm/IR/PassInstrumentation.h

200

Yes, it is necessary since runBeforePass - the only callback that increments PC - is const.
I'm not sure it buys us anything, so I can get rid of both const there and mutable here.
I dont care actually :)

[fedor.sergeev]

addressing comments

[fedor.sergeev]

typo

[fedor.sergeev]

moving PassInstrumentationProxy definition around (needed for subsequent changes
in AnalysisManager).

[fedor.sergeev]

adding unit tests

[chandlerc]

This is looking really, really good. Some comments below.

include/llvm/IR/PassInstrumentation.h

98–108

There is a lot of complexity here which seems largely designed to try and produce the opaque pointer. Especially as that pointer isn't really "reliable", is this really that important?

What breaks if we simply give the callback the name of the pass? Then we can just have the instrumentation object have templates that take a generic PassT &P and then do P.name() to get the name. This should work both with concrete passes and with all of the PassConcept objects (the real case).

I think the tuple of (name, IR unit) is about the most precise we can make the identity in the API.

This doesn't prevent the instrumentation callback from doing things like keeping counters and such internally to differentiate what is going on....

196

Why expose this? We can trivially implement the empty case anyways?

199

Why include this here? Seems like the counter stuff could be separate and just managed by the callbacks when wired up?

include/llvm/IR/PassManager.h

512

Now that we have multiple uses of Passes[Idx], I would hoist it into a variable.

581

No need for _ here (or anywhere else here). (And _PI is a reserved name.)

784–792

This coupling with the analysis manager seems really awkward. It makes it no longer "just an analysis". I'd really like to get back to that.

I see at least two ways to do this:

1. just bite the bullet and require that if you use an analysis manager, you have to register the instrumentation
2. Write a utility function that implements this but isn't part of the analysis manager.

I lean slightly toward #1, but maybe its way more awkward than I'm imagining? It would have the advantage of simplifying the code because yo uwould "always" have a (potentially trivial) instrumentation object.

[fedor.sergeev]

include/llvm/IR/PassInstrumentation.h

98–108

The problem is that "name" is not going to give callbacks a way to differentiate between *instances* of passes.
And, say, -time-passes functionality needs to collect timings per-instance.

196

The intent is to avoid overhead of instrumentation framework as much as possible for the case when there are no callbacks registered.
Current implementation provides nullptr to the proxy analysis instead of the empty Instrumentation object.
It saves some minor cycles on dereferencing and iteration through empty vectors.

First implementation had no need for empty() since PassBuilder was managing the object and avoided creating it altogether if no registrations requests were given. Current implementation manages PassInstrumentation outside of PassBuilder, so PassBuilder needs empty().

199

Oh, well... had an idea on making counters independent from callbacks decisions on skipping some passes, but then realized it is hardly possible overall. So yes, it can be made separate.
And then I hardly need to introduce this class at all here.

include/llvm/IR/PassManager.h

784–792

"just an analysis" is perhaps not fully true anyway, since it is the only analysis that is being explicitly queried in all the generic parts of the code, even in generic PassManager.
If we decide #1 then we essentially legalize it not being "just an analysis". And I'm fine with it.
It will require adding registration to all the PassManager tests that do not use PassBuilder currently (not a big deal either, just a hassle).

[philip.pfaffe]

include/llvm/IR/PassInstrumentation.h

98–108

How would a callback with a template argument look like, and how would you store it?

Can you do it without another Concept/Model pair capturing the Pass interface? Because I don't think that'd save a lot in terms of complexity.

include/llvm/IR/PassManager.h

784–792

I'd +1 the first way, too. When using a PassManager most of the time you're not free to run around with an empty AnalysisManager anyways, so the burden would be low, IMO.

[chandlerc]

include/llvm/IR/PassInstrumentation.h

98–108

It's not clear that time-passes needs this functionality.

My problem is that I think this overpromises something that we cannot actually deliver: This cannot capture the *iteration* count either, and that is just as much of a factor as the position in the pipeline.

If we want detailed statistics for timing, we should collect the time of *each* run (and the IR unit it ran over) and show them separately. For summary statistics, I think it just being the name is good in that it sets reasonable expectations.

98–108

The method on PassInstrumentation can be the template, and the callback just gets the StringRef for the name.

196

I thikn you should keep simplifying.

The cost of an empty for loop in the instrumentation is going to be tiny. We shouldn't add complexity to "avoid" it, especially when that complexity is a wider interface.

199

It still seems useful to hold the callbacks and handle the dispatch (with a template).

include/llvm/IR/PassManager.h

784–792

Yeah, the more I think, the more this can just be an analysis.

We can have a default constructor that leaves all the callbacks empty. It won't do anything interesting. But the code will be simple and work.

Then users can register more interesting ones as they like.

[fedor.sergeev]

updating a solution as per review comments as well as following
the design discussion we had on IRC.
Main directions:

• PassInstrumentation is split in two parts - callbacks/instrumenting points
• PassInstrumentationAnalysis returns PassInstrumentation
• no more PassCounter tracking in PassInstrumentation
• PassInstanceID is gone, not trying to track pass instance as we have no good mental model on what it actually is. Passing just StringRefs - pass names.
• using getResult<PassInstrumentationAnalysis> instead of getPassInstrumentation whenever possible (still using std::tuple variant in places where it needs to chop off AM args).

Most likely I forgot to mention something :)

[fedor.sergeev]

clang-formatting

[philip.pfaffe]

This is looking great. Apart from two things that aren't needed anymore, the last point of discussion is getPassInstrumentation. PassInstrumentationAnalysis shouldn't be a special citizen. What about making this a free function instead? In fact, why not make this a generic helper e.g. in the detail namespace to query _any_ analysis result from a template pass?

include/llvm/IR/PassInstrumentation.h

71

Is this still required?

147

Is this necessary?

include/llvm/IR/PassManagerInternal.h

85

Is this still required?

[fedor.sergeev]

adding const to PassInstrumentation::runAfterPass

[fedor.sergeev]

include/llvm/IR/PassInstrumentation.h

71

if I got Chandler right he asked me to keep it around for individual callbacks use.
I'm really not sure that it is needed anymore.

147

you mean the default copy? perhaps not. will delete it.

[fedor.sergeev]

include/llvm/IR/PassManagerInternal.h

85

definitely not

[fedor.sergeev]

addressing comments, moving getPassInstrumentation tuple helper into detail::getAnalysisResult
free function.

[philip.pfaffe]

At this point I'm bikeshedding: Should getAnalysisResultgo into the Internal header?

[fedor.sergeev]

In D47858#1235016, @philip.pfaffe wrote:

At this point I'm bikeshedding: Should getAnalysisResultgo into the Internal header?

Hmm.. I have no preference here. I can easily do that.
Chandler?

[chandlerc]

It gets better and better. Another round of comments.

include/llvm/IR/PassInstrumentation.h

16

"IT is light on copy since it is queries" -> "It is cheap to copy since it queries"

17

Not sure this explanation of why the copy is cheap quite parses for me.

20

extraneous -.

71

Sorry for ambiguity. I think you can pull it out for now. I would re-introduce it as part of the bisection in a way that fits with that framework.

107–113

I think this is one of those weird places and times where emplace and such is what you want.

Specifically, I think you should do:

template <typename CallableT> void registerAfterPassCallback(CallableT C) {
  AfterPassCallback.emplace_back(std::move(C));
}

Or something of the sort. You want to support passing a lambda w/ move only captures and not allocating memory for it in the caller, but only inside the vector.

120–131

Since you already befriend this class, why not just inline thes functions into their callers below?

133

I don't think this comment is really necessary.

134–135

I would suggest using llvm::unique_function throughout this code to support callbacks with move-only captures.

I generally suspect we should default to llvm::unique_function over std::function at this point until a need for copy arises.

144–145

Comment on ownership and lifetime?

include/llvm/IR/PassManager.h

484–490

Rather than assume we can do this generically with tuple-hacking of the parameter pack, I'd suggest simply assuming that the extra arguments match, and insisting for cases where they do not match we use explicit specializations of the relevant run method there to manually implement the logic.

We already do some of this. If it truly becomes problematic, I think we could solve it a different way instead, but I'm not sure it is worthwhile without seeing how many (and how much logic) ends up being duplicated w/ the specializations.

The reason I prefer specializations is that it places no firm contract on the relationship between the arguments. I'd prefer to not bake in such a relationship to the API because then we may end up designing things in awkward ways to satisfy this constraint.

568–571

I think we should either move all the instrumentation stuff into this header, or find a way to pull this into the separate header. I think the latter is possible but will require some refactorings. Can you leave a FIXME for now so that we come back to this?

578

I think a name like Callbacks would be easier to read than PIC.

762–764

Is this still needed?

include/llvm/IR/PassManagerInternal.h

51

This and all of the other changes to PassManagerInternal.h are really orthogonal cleanups and LGTM. Please pull them into their own patch and go ahead and land that.

include/llvm/Passes/PassBuilder.h

63–65

Since the code constructing this has access to the callbacks already, why do we need to expose it? I'd rather keep the API narrow (like we do for TM above).

564–568

I'm somewhat curious what the expected usage of this method is? It isn't obvious to me at all...

lib/Passes/PassBuilder.cpp

318–320

No need for any of this -- you can use the PassRegistrsy.def and write PassInstrumentationAnalysis(PIC). That's how we already do things with TM.

unittests/IR/PassBuilderCallbacksTest.cpp

268–272

Instead of this, you can use ::testing::NiceMock<MockPassInstrumentationCallbacks> in places where you want to ignore these. The way you've written it, even if users *want* to check for unexpected calls to these routines, they won't be able to do so.

283–284

Maybe leave a FIXME here?

We should design a good matcher for llvm::Any and then we should be able to compose things. But this is fine for now.

301

Missing vertical space.

423–424

std::bind should generally be avoided at this point. We can just use lambdas to delegate here.

And see my comment on registerPassInstrumentian above: I think instead we should just register the callbacks first, and hand the object into the pass builder.

Notably, I think you can have the mock *contain* a PassInstrumentationCallbacks object that it pre-registers with lambdas that delegate to the mock, and then just pass that into PassBuilder constructor.

463–464

I find it simpler to define a Sequence object and then connect it to each expectation with the .InSequence methods. This makes it fairly easy to avoid a proliferation of scopes to wire these things up.

You'll also want to say how *many* calls here, which will make more sense once you make the change I suggest above w.r.t. the number.

[fedor.sergeev]

Thanks for a deep review.

include/llvm/IR/PassInstrumentation.h

17

It doesnt quite parse for me as well :)
Pehaps I meant "since it is being queried through the analysis framework".
Will try to reword it in a more straightforward way.

134–135

hmm... did not know about llvm::unique_function.

include/llvm/IR/PassManager.h

568–571

I'm afraid I dont quite follow. Pull *what* into the separate header?
PassInstrumentationAnalysis definition altogether? or anything else?

And I dont like the idea of putting instrumentation stuff into this header.
It is already quite packed with different concepts.
Instrumentation looks distinct enough to deserve its own header.

include/llvm/Passes/PassBuilder.h

564–568

It allows to use PassBuilder as sort of a central place for registering all the callbacks, w/o polluting Passbuilder with all the interfaces.
Particularly useful for plugins, I believe.
You can see how it is being used in -print-after-all and -pass-times implementation followups or in the unittests.

Alternative solution would be to introduce PassBuilder::getPassInstrumentationCallbacks() method and use it for registration purposes, but I did not really like that (and yes, getPassInstrumentationCallbacks should have been dropped).

unittests/IR/PassBuilderCallbacksTest.cpp

268–272

To be honest, my gmock voodoo is weak at best.
I was under impression that my InstrumentedSkippedPasses subtests check exactly for the routines not being called. Did I fail to test that?
(I will go read about NiceMock and see what I can do here)

283–284

Do you mean a good matcher for llvm::Any or a good generic unwrapper from llvm::Any into IRUnit?
Since llvm::Any is just "any", I find it hard to imagine a good generic matcher for it...

423–424

register the callbacks first

What about instrumentation that plugins want to install?
RegisterPassBuilderCallbacks does not have access to anything else except PassBuilder.

pre-registers with lambdas that delegate to the mock

Hmm... here again my weak gtest/gmock knowledge fails me.
I dont see how can I pass control to fixture constructor from mock side inside , say, TEST_F(ModuleCallbacksTest, InstrumentedPasses) - isnt it in action only when Test object (and its PassBuilder member) have already been constructed?
Care to drop a quick sketch of this idea?

463–464

Ok, will try the sequence thing.
And about how many calls - I thought EXPECT_CALL by default means Times(1)?

[philip.pfaffe]

include/llvm/Passes/PassBuilder.h

564–568

For plugins I'd really like to retain some means of accessing the Callbacks registry through PassBuilder. To keep it off the PassBuilder API, maybe we should pass it in the plugin APIs RegisterPassBuilderCallbacks instead? Could be done in a followup change.

[fedor.sergeev]

addressing most of the comments except getAnalysisResults.

[fedor.sergeev]

unittests/IR/PassBuilderCallbacksTest.cpp

463–464

Did the sequencing change, still leaving EXPECT_CALL w/o Times(1) for brevity.

[chandlerc]

include/llvm/IR/PassInstrumentation.h

17

"light" i think is still less clear than "clear".

86–92

My suggestion was to go a step further, and have these be template methods that can accept an arbitrary callable (IE, a template).

If they get called with an existing unique_function, then it'll work like what you have here, but if they get called with a lambda (common case), they will construct the unique_function in place in the vector from the lambda.

104–106

I would sink this comment to the constructor, as that is the public API that requires the lifetime. This is just the implementation detail of it.

121

Naming conventions: ShouldRun.

include/llvm/IR/PassManager.h

568–571

I agree that it is best if the instrumentation stuff can be in its own header.

what seems good to extract to a separate header is the PassInstrumentationAnalysis. I'm not suggesting you do that in this patch, just leave a FIXME.

include/llvm/Passes/PassBuilder.h

564–568

I'd prefer to sort out what makes sense for plugins in a separate patch.

I think it is better (until we know what plugins actually need) to simply have users do their registration on the PassInstrumentationCallbacks object they give to the PassBuilder. For example, we don't expose any hooks to manipulate the TargetMachine from the PassBuilder -- instead, clients set it up directly themselves.

unittests/IR/PassBuilderCallbacksTest.cpp

423–424

The callbacks object isn't *copied* into the PassBuilder -- you can leave it as a member of the fixture and directly register things onto it?

As I mention above -- I would suggest we sort out the good plugin API when we're actually building the plugin API. Even if it means we end up changing this code because it becomes easier to write it in a different way, that seems OK. Because then, we will *actually* have plugin stuff to look at, rather than hypothesizing how it might look.

463–464

So, this EXPECT_CALL does the .Times(1), but once that expectation is saturated, there is still another expectation from the constructor that can accept as many calls as you make. So I would expect this to not fail if you call it *too many* times, only if you call it *too few*.

[fedor.sergeev]

addressing most of the comments - cleanup, unittests etc
(except getAnalysisResult, for which see D52169).

[andrew.w.kaylor]

include/llvm/IR/PassInstrumentation.h

51

This is actually fairly important. There are many passes that will cause compilation to fail if they are skipped.

Maybe instead of having the pass managers not run the pass, you could add an argument to the run function that indicates the pass should be skipped if possible? That feels fairly clunky. The alternative is to have some way for the pass managers to detect that the passes cannot be skipped, and I suspect we don't want to do that either.

[philip.pfaffe]

include/llvm/IR/PassInstrumentation.h

51

Passes shouldn't be able to control this I think. That burden should be on the instrumentation.

[fedor.sergeev]

include/llvm/IR/PassInstrumentation.h

51

This is marked as TODO :)
There are ways to allow passes opt-in/out of pass skipping, its just not a focus here.
After current series of patches will be landed I will start approaching OptBisect and then we will beat this dead horse till it is fully dead.

[andrew.w.kaylor]

include/llvm/IR/PassInstrumentation.h

51

But the instrumentation can't make this decision without having explicit knowledge about the pass. The pass itself is really the only thing that knows whether or not it can be skipped.

[andrew.w.kaylor]

include/llvm/IR/PassInstrumentation.h

51

That's fair. It doesn't need to be solved now, but I think that until it is solved the default behavior should be to not skip any passes.

[fedor.sergeev]

include/llvm/IR/PassInstrumentation.h

51

There are still uses to the skip functionality even if it does not result in successful compilation.
Say, we downstream have a patch that gracefully stops compilation when it exceeds some resource limit,
and there we do not actually care about a successful compilation but just in graceful abort that does not leaks resources.

In this patch ability to skip the pass is more or less just a proof of concept.
Instrumentations suggested in dependent patches (-print-after-all and -time-passes) do not use skipping ability either.

I would say - if it raises questions then I'm glad it is written this way :)

[andrew.w.kaylor]

include/llvm/IR/PassInstrumentation.h

51

OK. I can live with it like this for now.

By the way, since I finally got around to commenting, I should say that I really like this design. Thanks for the work!

[chandlerc]

LGTM (provided Philip is still happy here, I know I asked to remove his plugin hooks).

I think this is good to go in. I want to keep pushing on the tuple based analysis results stuff, but I'm happy to do that in the follow-up change. I've left some much more minor comments below. If they make sense, feel free to land this with them addressed and we'll get to the follow-ups. =D

Thanks again *so much* for the huge effort working on this. I know it was really complex, and I'm really happy with the result.

include/llvm/IR/PassInstrumentation.h

128

Slightly stale comment re. PassID.

unittests/IR/PassBuilderCallbacksTest.cpp

336–342

Do you just want to do this in the constructor?

344–355

This is nice!

[philip.pfaffe]

So I'd still prefer a generic free getAnalysisResult, plus specializations for the non-simple cases, e.g. Loop and CGSCC. That way there's less surprises should there ever be a 'weird' AnalysisManager out there using a different argument mapping. Happy to do this in a followup though!

Thank you again for bearing through this lengthy review process!

[fedor.sergeev]

unittests/IR/PassBuilderCallbacksTest.cpp

336–342

No, I dont.
I want to skip registering any callbacks in tests that do not explicitly enable pass instrumentation.

[fedor.sergeev]

Was reverted because of massive buildbot failures - all failing to compile PassBuilderCallbacks unit-test, like this:

/usr/lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/type_traits:933:14: error: base class has incomplete type
    : public is_constructible<_Tp, const _Tp&>
      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/type_traits:939:14: note: in instantiation of template class 'std::__is_copy_constructible_impl<testing::Matcher<llvm::Any>, true>' requested here
    : public __is_copy_constructible_impl<_Tp>
             ^
/home/llvmbb/llvm-build-dir/clang-x86_64-debian-fast/llvm.src/include/llvm/ADT/STLExtras.h:69:49: note: in instantiation of template class 'std::is_copy_constructible<testing::Matcher<llvm::Any> >' requested here
template <typename B1> struct conjunction<B1> : B1 {};

[fedor.sergeev]

adding a hack to PassBuilderCallbacks unittest that allows
to use llvm::Any in mocks.

[fedor.sergeev]

Sanitizer buildbots failed on CGSCC tests due to improper getName handling (StringRef on a temporary std::string cant fly well)

[fedor.sergeev]

changed getName helper in unittests to return std::string instead of StringRef
to avoid addressing temporaries after their lifetime end.Z

include/llvm/Analysis/CGSCCPassManager.h

PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM) {
 
     SmallDenseSet<std::pair<LazyCallGraph::Node *, LazyCallGraph::SCC *>, 4>
         InlinedInternalEdges;
 
     CGSCCUpdateResult UR = {RCWorklist,          CWorklist, InvalidRefSCCSet,
                             InvalidSCCSet,       nullptr,   nullptr,
                             InlinedInternalEdges};
 
+    // Request PassInstrumentation from analysis manager, will use it to run
+    // instrumenting callbacks for the passes later.
+    PassInstrumentation PI = AM.getResult<PassInstrumentationAnalysis>(M);
+
     PreservedAnalyses PA = PreservedAnalyses::all();
     CG.buildRefSCCs();
     for (auto RCI = CG.postorder_ref_scc_begin(),
               RCE = CG.postorder_ref_scc_end();
          RCI != RCE;) {
       assert(RCWorklist.empty() &&
              "Should always start with an empty RefSCC worklist");
       // The postorder_ref_sccs range we are walking is lazily constructed, so
for (auto RCI = CG.postorder_ref_scc_begin(),
             // Check that we didn't miss any update scenario.
             assert(!InvalidSCCSet.count(C) && "Processing an invalid SCC!");
             assert(C->begin() != C->end() && "Cannot have an empty SCC!");
             assert(&C->getOuterRefSCC() == RC &&
                    "Processing an SCC in a different RefSCC!");
 
             UR.UpdatedRC = nullptr;
             UR.UpdatedC = nullptr;
+
+            // Check the PassInstrumentation's BeforePass callbacks before
+            // running the pass, skip its execution completely if asked to
+            // (callback returns false).
+            if (!PI.runBeforePass<LazyCallGraph::SCC>(Pass, *C))
+              continue;
+
             PreservedAnalyses PassPA = Pass.run(*C, CGAM, CG, UR);
 
+            PI.runAfterPass<LazyCallGraph::SCC>(Pass, *C);
+
             // Update the SCC and RefSCC if necessary.
             C = UR.UpdatedC ? UR.UpdatedC : C;
             RC = UR.UpdatedRC ? UR.UpdatedRC : RC;
 
             // If the CGSCC pass wasn't able to provide a valid updated SCC,
             // the current SCC may simply need to be skipped if invalid.
             if (UR.InvalidatedSCCs.count(C)) {
               LLVM_DEBUG(dbgs()
PreservedAnalyses run(LazyCallGraph::SCC &C, CGSCCAnalysisManager &AM,
     PreservedAnalyses PA = PreservedAnalyses::all();
     for (LazyCallGraph::Node *N : Nodes) {
       // Skip nodes from other SCCs. These may have been split out during
       // processing. We'll eventually visit those SCCs and pick up the nodes
       // there.
       if (CG.lookupSCC(*N) != CurrentC)
         continue;
 
-      PreservedAnalyses PassPA = Pass.run(N->getFunction(), FAM);
+      Function &F = N->getFunction();
+
+      PassInstrumentation PI = FAM.getResult<PassInstrumentationAnalysis>(F);
+      if (!PI.runBeforePass<Function>(Pass, F))
+        continue;
+
+      PreservedAnalyses PassPA = Pass.run(F, FAM);
+
+      PI.runAfterPass<Function>(Pass, F);
 
       // We know that the function pass couldn't have invalidated any other
       // function's analyses (that's the contract of a function pass), so
       // directly handle the function analysis manager's invalidation here.
-      FAM.invalidate(N->getFunction(), PassPA);
+      FAM.invalidate(F, PassPA);
 
       // Then intersect the preserved set so that invalidation of module
       // analyses will eventually occur when the module pass completes.
       PA.intersect(std::move(PassPA));
 
       // If the call graph hasn't been preserved, update it based on this
       // function pass. This may also update the current SCC to point to
       // a smaller, more refined SCC.
public:
   explicit DevirtSCCRepeatedPass(PassT Pass, int MaxIterations)
       : Pass(std::move(Pass)), MaxIterations(MaxIterations) {}
 
   /// Runs the wrapped pass up to \c MaxIterations on the SCC, iterating
   /// whenever an indirect call is refined.
   PreservedAnalyses run(LazyCallGraph::SCC &InitialC, CGSCCAnalysisManager &AM,
                         LazyCallGraph &CG, CGSCCUpdateResult &UR) {
     PreservedAnalyses PA = PreservedAnalyses::all();
+    PassInstrumentation PI =
+        AM.getResult<PassInstrumentationAnalysis>(InitialC, CG);
 
     // The SCC may be refined while we are running passes over it, so set up
     // a pointer that we can update.
     LazyCallGraph::SCC *C = &InitialC;
 
     // Collect value handles for all of the indirect call sites.
     SmallVector<WeakTrackingVH, 8> CallHandles;
 
auto ScanSCC = [](LazyCallGraph::SCC &C,
 
       return CallCounts;
     };
 
     // Populate the initial call handles and get the initial call counts.
     auto CallCounts = ScanSCC(*C, CallHandles);
 
     for (int Iteration = 0;; ++Iteration) {
+
+      if (!PI.runBeforePass<LazyCallGraph::SCC>(Pass, *C))
+        continue;
+
       PreservedAnalyses PassPA = Pass.run(*C, AM, CG, UR);
 
+      PI.runAfterPass<LazyCallGraph::SCC>(Pass, *C);
+
       // If the SCC structure has changed, bail immediately and let the outer
       // CGSCC layer handle any iteration to reflect the refined structure.
       if (UR.UpdatedC && UR.UpdatedC != C) {
         PA.intersect(std::move(PassPA));
         break;
       }
 
       // Check that we didn't miss any update scenario.

include/llvm/IR/PassInstrumentation.h

+//===- llvm/IR/PassInstrumentation.h ----------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+///
+/// This file defines the Pass Instrumentation classes that provide
+/// instrumentation points into the pass execution by PassManager.
+///
+/// There are two main classes:
+///   - PassInstrumentation provides a set of instrumentation points for
+///     pass managers to call on. It is light on copy since it is queries
+///     through the analysis framework as a result of the analysis.
+///
+///   - PassInstrumentationCallbacks registers callbacks and provides access
+///   - to them for PassInstrumentation.
+///
+/// PassInstrumentation object is light on copy since it is being
+/// used as a result of PassInstrumentationAnalysis.
+///
+/// Intended scheme of use for Pass Instrumentation is as follows:
+///    - register instrumentation callbacks in PassInstrumentationCallbacks
+///      instance. PassBuilder provides helper for that.
+///
+///    - register PassInstrumentationAnalysis with all the PassManagers.
+///      PassBuilder handles that automatically when registering analyses.
+///
+///    - Pass Manager requests PassInstrumentationAnalysis from analysis manager
+///      and gets PassInstrumentation as its result.
+///
+///    - Pass Manager invokes PassInstrumentation entry points appropriately,
+///      passing StringRef identification ("name") of the pass currently being
+///      executed and IRUnit it works on. There can be different schemes of
+///      providing names in future, currently it is just a name() of the pass.
+///
+///    - PassInstrumentation wraps address of IRUnit into llvm::Any and passes
+///      control to all the registered callbacks. Note that we specifically wrap
+///      'const IRUnitT*' so as to avoid any accidental changes to IR in
+///      instrumenting callbacks.
+///
+///    - Some instrumentation points (BeforePass) allow to control execution
+///      of a pass. For those callbacks returning false means pass will not be
+///      executed.
+///
+/// TODO: currently there is no way for a pass to opt-out of execution control
+/// (e.g. become unskippable). PassManager is the only entity that determines
+/// how pass instrumentation affects pass execution.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_IR_PASSINSTRUMENTATION_H
+#define LLVM_IR_PASSINSTRUMENTATION_H
+
+#include "llvm/ADT/Any.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/Support/TypeName.h"
+#include <type_traits>
+
+namespace llvm {
+
+class PreservedAnalyses;
+
+/// This class provides a simple way to track execution of passes.
+/// It is intended as a helper for individual instrumentation callbacks
+/// that need to track pass execution.
+class PassExecutionCounter {
+  unsigned count = 0;
+
+public:
+  PassExecutionCounter() = default;
+  PassExecutionCounter(const PassExecutionCounter &PC) = default;
+  PassExecutionCounter(PassExecutionCounter &&PC) = default;
+
+  PassExecutionCounter &operator=(const PassExecutionCounter &PC) {
+    count = PC.count;
+    return *this;
+  }
+
+  operator int() const { return count; }
+
+  /// preincrement, advance the counter
+  void operator++() { count++; }
+};
+
+/// This class manages callbacks registration, as well as provides a way for
+/// PassInstrumentation to pass control to the registered callbacks.
+class PassInstrumentationCallbacks {
+public:
+  // Before/After Pass callbacks accept IRUnits, so they need to take them
+  // as pointers, wrapped with llvm::Any
+  using BeforePassFunc = bool(StringRef, Any);
+  using AfterPassFunc = void(StringRef, Any);
+  using BeforeAnalysisFunc = void(StringRef, Any);
+  using AfterAnalysisFunc = void(StringRef, Any);
+
+public:
+  PassInstrumentationCallbacks() {}
+
+  /// Copying PassInstrumentationCallbacks is not intended.
+  PassInstrumentationCallbacks(const PassInstrumentationCallbacks &) = delete;
+  void operator=(const PassInstrumentationCallbacks &) = delete;
+
+  void registerBeforePassCallback(const std::function<BeforePassFunc> &C) {
+    BeforePassCallbacks.push_back(C);
+  }
+
+  void registerAfterPassCallback(const std::function<AfterPassFunc> &C) {
+    AfterPassCallbacks.push_back(C);
+  }
+
+private:
+  // Instrumentation calls should not be used as a public interface.
+  // Only for consumption by PassInstrumentation.
+  friend class PassInstrumentation;
+
+  /// BeforePass instrumentation point - takes \p PassID identifier for the
+  /// pass instance to be executed and constant reference to IR it operates on.
+  /// Note, that PassID currently is not meant to be unique per-pass-instance.
+  /// \Returns true if pass is allowed to be executed.
+  template <typename IRUnitT>
+  bool runBeforePass(StringRef PassID, const IRUnitT &) const;
+
+  /// AfterPass instrumentation point - takes \p PassID identifier for the pass
+  /// instance that has just been and constant reference to IR it operated on.
+  /// Note, that PassID currently is not meant to be unique per-pass-instance.
+  template <typename IRUnitT>
+  void runAfterPass(StringRef PassID, const IRUnitT &) const;
+
+  // instrumentation callbacks
+  SmallVector<std::function<BeforePassFunc>, 4> BeforePassCallbacks;
+  SmallVector<std::function<AfterPassFunc>, 4> AfterPassCallbacks;
+};
+
+/// This class provides instrumentation entry points for the Pass Manager,
+/// doing calls to callbacks registered in PassInstrumentationCallbacks.
+class PassInstrumentation {
+  const PassInstrumentationCallbacks *Callbacks;
+
+public:
+  PassInstrumentation(const PassInstrumentationCallbacks *CB = nullptr)
+      : Callbacks(CB) {}
+
+  /// BeforePass instrumentation point - takes \p Pass instance to be executed
+  /// and constant reference to IR it operates on. \Returns true if pass is
+  /// allowed to be executed.
+  template <typename IRUnitT, typename PassT>
+  bool runBeforePass(const PassT &Pass, const IRUnitT &IR) const {
+    if (Callbacks)
+      return Callbacks->runBeforePass(Pass.name(), IR);
+    return true;
+  }
+
+  /// AfterPass instrumentation point - takes \p PassID instance that has
+  /// just been executed and constant reference to IR it operates on.
+  template <typename IRUnitT, typename PassT>
+  void runAfterPass(const PassT &Pass, const IRUnitT &IR) const {
+    if (Callbacks)
+      Callbacks->runAfterPass(Pass.name(), IR);
+  }
+
+  /// Handle invalidation from the pass manager when PassInstrumentation
+  /// is used as the result of PassInstrumentationAnalysis.
+  ///
+  /// On attempt to invalidate just return false. There is nothing to become
+  /// invalid here.
+  template <typename IRUnitT, typename... ExtraArgsT>
+  bool invalidate(IRUnitT &, const class llvm::PreservedAnalyses &,
+                  ExtraArgsT...) {
+    return false;
+  }
+};
+
+} // namespace llvm
+
+#endif

include/llvm/IR/PassManager.h

 #define LLVM_IR_PASSMANAGER_H
 
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/TinyPtrVector.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/Module.h"
+#include "llvm/IR/PassInstrumentation.h"
 #include "llvm/IR/PassManagerInternal.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/TypeName.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 #include <cassert>
 #include <cstring>
 #include <iterator>
struct AnalysisInfoMixin : PassInfoMixin<DerivedT> {
   /// configuration, this mixin can provide the static key as well.
   static AnalysisKey *ID() {
     static_assert(std::is_base_of<AnalysisInfoMixin, DerivedT>::value,
                   "Must pass the derived type as the template argument!");
     return &DerivedT::Key;
   }
 };
 
+namespace detail {
+
+/// Actual unpacker of extra arguments in getAnalysisResult,
+/// passes only those tuple arguments that are mentioned in index_sequence.
+template <typename PassT, typename IRUnitT, typename AnalysisManagerT,
+          typename... ArgTs, size_t... Ns>
+typename PassT::Result
+getAnalysisResultUnpackTuple(AnalysisManagerT &AM, IRUnitT &IR,
+                             std::tuple<ArgTs...> Args,
+                             llvm::index_sequence<Ns...>) {
+  (void)Args;
+  return AM.template getResult<PassT>(IR, std::get<Ns>(Args)...);
+}
+
+/// Helper for *partial* unpacking of extra arguments in getAnalysisResult.
+///
+/// Arguments passed in tuple come from PassManager, so they might have extra
+/// arguments after those AnalysisManager's ExtraArgTs ones that we need to
+/// pass to getResult.
+template <typename PassT, typename IRUnitT, typename... AnalysisArgTs,
+          typename... MainArgTs>
+typename PassT::Result
+getAnalysisResult(AnalysisManager<IRUnitT, AnalysisArgTs...> &AM, IRUnitT &IR,
+                  std::tuple<MainArgTs...> Args) {
+  return (getAnalysisResultUnpackTuple<
+          PassT, IRUnitT>)(AM, IR, Args,
+                           llvm::index_sequence_for<AnalysisArgTs...>{});
+}
+
+} // namespace detail
+
+// Forward declare the pass instrumentation analysis explicitly queried in
+// generic PassManager code.
+class PassInstrumentationAnalysis;
+
 /// Manages a sequence of passes over a particular unit of IR.
 ///
 /// A pass manager contains a sequence of passes to run over a particular unit
 /// of IR (e.g. Functions, Modules). It is itself a valid pass over that unit of
 /// IR, and when run over some given IR will run each of its contained passes in
 /// sequence. Pass managers are the primary and most basic building block of a
 /// pass pipeline.
 ///
public:
   }
 
   /// Run all of the passes in this manager over the given unit of IR.
   /// ExtraArgs are passed to each pass.
   PreservedAnalyses run(IRUnitT &IR, AnalysisManagerT &AM,
                         ExtraArgTs... ExtraArgs) {
     PreservedAnalyses PA = PreservedAnalyses::all();
 
+    // Request PassInstrumentation from analysis manager, will use it to run
+    // instrumenting callbacks for the passes later.
+    // Here we use std::tuple wrapper over getResult which helps to extract
+    // AnalysisManager's arguments out of the whole ExtraArgs set.
+    PassInstrumentation PI =
+        detail::getAnalysisResult<PassInstrumentationAnalysis>(
+            AM, IR, std::tuple<ExtraArgTs...>(ExtraArgs...));
+
     if (DebugLogging)
       dbgs() << "Starting " << getTypeName<IRUnitT>() << " pass manager run.\n";
 
     for (unsigned Idx = 0, Size = Passes.size(); Idx != Size; ++Idx) {
+      auto *P = Passes[Idx].get();
       if (DebugLogging)
-        dbgs() << "Running pass: " << Passes[Idx]->name() << " on "
-               << IR.getName() << "\n";
+        dbgs() << "Running pass: " << P->name() << " on " << IR.getName()
+               << "\n";
+
+      // Check the PassInstrumentation's BeforePass callbacks before running the
+      // pass, skip its execution completely if asked to (callback returns
+      // false).
+      if (!PI.runBeforePass<IRUnitT>(*P, IR))
+        continue;
+
+      PreservedAnalyses PassPA = P->run(IR, AM, ExtraArgs...);
 
-      PreservedAnalyses PassPA = Passes[Idx]->run(IR, AM, ExtraArgs...);
+      // Call onto PassInstrumentation's AfterPass callbacks immediately after
+      // running the pass.
+      PI.runAfterPass<IRUnitT>(*P, IR);
 
       // Update the analysis manager as each pass runs and potentially
       // invalidates analyses.
       AM.invalidate(IR, PassPA);
 
       // Finally, intersect the preserved analyses to compute the aggregate
       // preserved set for this pass manager.
       PA.intersect(std::move(PassPA));
 

 /// Convenience typedef for a pass manager over modules.
 using ModulePassManager = PassManager<Module>;
 
 extern template class PassManager<Function>;
 
 /// Convenience typedef for a pass manager over functions.
 using FunctionPassManager = PassManager<Function>;
 
+/// Pseudo-analysis pass that exposes the \c PassInstrumentation to pass
+/// managers. Goes before AnalysisManager definition to provide its
+/// internals (e.g PassInstrumentationAnalysis::ID) for use there if needed.
+class PassInstrumentationAnalysis
+    : public AnalysisInfoMixin<PassInstrumentationAnalysis> {
+  friend AnalysisInfoMixin<PassInstrumentationAnalysis>;
+  static AnalysisKey Key;
+
+  /// Shared PassInstrumentation object. Owned by something else, not this
+  /// analysis.
+  PassInstrumentationCallbacks *PIC;
+
+public:
+  PassInstrumentationAnalysis(PassInstrumentationCallbacks *PIC = nullptr)
+      : PIC(PIC) {}
+
+  using Result = PassInstrumentation;
+
+  template <typename IRUnitT, typename AnalysisManagerT, typename... ExtraArgTs>
+  Result run(IRUnitT &, AnalysisManagerT &, ExtraArgTs &&...) {
+    return PassInstrumentation(PIC);
+  }
+};
+
 /// A container for analyses that lazily runs them and caches their
 /// results.
 ///
 /// This class can manage analyses for any IR unit where the address of the IR
 /// unit sufficies as its identity.
 template <typename IRUnitT, typename... ExtraArgTs> class AnalysisManager {
 public:
   class Invalidator;
public:
   /// deletes them.  This lets you clean up the AnalysisManager when the set of
   /// IR units itself has potentially changed, and thus we can't even look up a
   /// a result and invalidate/clear it directly.
   void clear() {
     AnalysisResults.clear();
     AnalysisResultLists.clear();
   }
 
+  template <typename PassT> bool isRegisteredAnalysis() const {
+    return AnalysisPasses.count(PassT::ID()) != 0;
+  }
+
   /// Get the result of an analysis pass for a given IR unit.
   ///
   /// Runs the analysis if a cached result is not available.
   template <typename PassT>
   typename PassT::Result &getResult(IRUnitT &IR, ExtraArgTs... ExtraArgs) {
     assert(AnalysisPasses.count(PassT::ID()) &&
            "This analysis pass was not registered prior to being queried");
     ResultConceptT &ResultConcept =
         getResultImpl(PassT::ID(), IR, ExtraArgs...);
 
     using ResultModelT =
         detail::AnalysisResultModel<IRUnitT, PassT, typename PassT::Result,
                                     PreservedAnalyses, Invalidator>;
 
     return static_cast<ResultModelT &>(ResultConcept).Result;
   }
 
   /// Get the cached result of an analysis pass for a given IR unit.
   ///
   /// This method never runs the analysis.
   ///
   /// \returns null if there is no cached result.
   template <typename PassT>
   typename PassT::Result *getCachedResult(IRUnitT &IR) const {
     assert(AnalysisPasses.count(PassT::ID()) &&
            "This analysis pass was not registered prior to being queried");
 
     ResultConceptT *ResultConcept = getCachedResultImpl(PassT::ID(), IR);
     if (!ResultConcept)
       return nullptr;
 
     using ResultModelT =
         detail::AnalysisResultModel<IRUnitT, PassT, typename PassT::Result,
                                     PreservedAnalyses, Invalidator>;
 
ResultConceptT &getResultImpl(AnalysisKey *ID, IRUnitT &IR,
 
     // If we don't have a cached result for this function, look up the pass and
     // run it to produce a result, which we then add to the cache.
     if (Inserted) {
       auto &P = this->lookUpPass(ID);
       if (DebugLogging)
         dbgs() << "Running analysis: " << P.name() << " on " << IR.getName()
                << "\n";
       AnalysisResultListT &ResultList = AnalysisResultLists[&IR];
       ResultList.emplace_back(ID, P.run(IR, *this, ExtraArgs...));
 
       // P.run may have inserted elements into AnalysisResults and invalidated
       // RI.
       RI = AnalysisResults.find({ID, &IR});
       assert(RI != AnalysisResults.end() && "we just inserted it!");
 
       RI->second = std::prev(ResultList.end());
private:
 
   static AnalysisKey Key;
 
   const AnalysisManagerT *AM;
 };
 
 template <typename AnalysisManagerT, typename IRUnitT, typename... ExtraArgTs>
 AnalysisKey
     OuterAnalysisManagerProxy<AnalysisManagerT, IRUnitT, ExtraArgTs...>::Key;
 
 extern template class OuterAnalysisManagerProxy<ModuleAnalysisManager,
                                                 Function>;
 /// Provide the \c ModuleAnalysisManager to \c Function proxy.
 using ModuleAnalysisManagerFunctionProxy =
     OuterAnalysisManagerProxy<ModuleAnalysisManager, Function>;
 
 /// Trivial adaptor that maps from a module to its functions.
public:
   explicit ModuleToFunctionPassAdaptor(FunctionPassT Pass)
       : Pass(std::move(Pass)) {}
 
   /// Runs the function pass across every function in the module.
   PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM) {
     FunctionAnalysisManager &FAM =
         AM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
 
+    // Request PassInstrumentation from analysis manager, will use it to run
+    // instrumenting callbacks for the passes later.
+    PassInstrumentation PI = AM.getResult<PassInstrumentationAnalysis>(M);
+
     PreservedAnalyses PA = PreservedAnalyses::all();
     for (Function &F : M) {
       if (F.isDeclaration())
         continue;
 
+      // Check the PassInstrumentation's BeforePass callbacks before running the
+      // pass, skip its execution completely if asked to (callback returns
+      // false).
+      if (!PI.runBeforePass<Function>(Pass, F))
+        continue;
       PreservedAnalyses PassPA = Pass.run(F, FAM);
 
+      PI.runAfterPass(Pass, F);
+
       // We know that the function pass couldn't have invalidated any other
       // function's analyses (that's the contract of a function pass), so
       // directly handle the function analysis manager's invalidation here.
       FAM.invalidate(F, PassPA);
 
       // Then intersect the preserved set so that invalidation of module
       // analyses will eventually occur when the module pass completes.
       PA.intersect(std::move(PassPA));

 /// This can be useful when debugging or testing passes. It also serves as an
 /// example of how to extend the pass manager in ways beyond composition.
 template <typename PassT>
 class RepeatedPass : public PassInfoMixin<RepeatedPass<PassT>> {
 public:
   RepeatedPass(int Count, PassT P) : Count(Count), P(std::move(P)) {}
 
   template <typename IRUnitT, typename AnalysisManagerT, typename... Ts>
-  PreservedAnalyses run(IRUnitT &Arg, AnalysisManagerT &AM, Ts &&... Args) {
+  PreservedAnalyses run(IRUnitT &IR, AnalysisManagerT &AM, Ts &&... Args) {
+
+    // Request PassInstrumentation from analysis manager, will use it to run
+    // instrumenting callbacks for the passes later.
+    // Here we use std::tuple wrapper over getResult which helps to extract
+    // AnalysisManager's arguments out of the whole Args set.
+    PassInstrumentation PI =
+        detail::getAnalysisResult<PassInstrumentationAnalysis>(
+            AM, IR, std::tuple<Ts...>(Args...));
+
     auto PA = PreservedAnalyses::all();
-    for (int i = 0; i < Count; ++i)
-      PA.intersect(P.run(Arg, AM, std::forward<Ts>(Args)...));
+    for (int i = 0; i < Count; ++i) {
+      // Check the PassInstrumentation's BeforePass callbacks before running the
+      // pass, skip its execution completely if asked to (callback returns
+      // false).
+      if (!PI.runBeforePass<IRUnitT>(P, IR))
+        continue;
+      PA.intersect(P.run(IR, AM, std::forward<Ts>(Args)...));
+      PI.runAfterPass(P, IR);
+    }
     return PA;
   }
 
 private:
   int Count;
   PassT P;
 };
 
 template <typename PassT>
 RepeatedPass<PassT> createRepeatedPass(int Count, PassT P) {
   return RepeatedPass<PassT>(Count, std::move(P));
 }
 
 } // end namespace llvm
 
 #endif // LLVM_IR_PASSMANAGER_H

include/llvm/IR/PassManagerInternal.h

struct PassConcept {
   ///
   /// Note that actual pass object can omit the analysis manager argument if
   /// desired. Also that the analysis manager may be null if there is no
   /// analysis manager in the pass pipeline.
   virtual PreservedAnalyses run(IRUnitT &IR, AnalysisManagerT &AM,
                                 ExtraArgTs... ExtraArgs) = 0;
 
   /// Polymorphic method to access the name of a pass.
-  virtual StringRef name() = 0;
+  virtual StringRef name() const = 0;
 };
 
 /// A template wrapper used to implement the polymorphic API.
 ///
 /// Can be instantiated for any object which provides a \c run method accepting
 /// an \c IRUnitT& and an \c AnalysisManager<IRUnit>&. It requires the pass to
 /// be a copyable object.
 template <typename IRUnitT, typename PassT, typename PreservedAnalysesT,
PassModel &operator=(PassModel RHS) {
     return *this;
   }
 
   PreservedAnalysesT run(IRUnitT &IR, AnalysisManagerT &AM,
                          ExtraArgTs... ExtraArgs) override {
     return Pass.run(IR, AM, ExtraArgs...);
   }
 
-  StringRef name() override { return PassT::name(); }
+  StringRef name() const override { return PassT::name(); }
 
   PassT Pass;
 };
 
 /// Abstract concept of an analysis result.
 ///
 /// This concept is parameterized over the IR unit that this result pertains
 /// to.
 template <typename IRUnitT, typename PreservedAnalysesT, typename InvalidatorT>
 struct AnalysisResultConcept {
struct AnalysisPassConcept {
   /// \returns A unique_ptr to the analysis result object to be queried by
   /// users.
   virtual std::unique_ptr<
       AnalysisResultConcept<IRUnitT, PreservedAnalysesT, InvalidatorT>>
   run(IRUnitT &IR, AnalysisManager<IRUnitT, ExtraArgTs...> &AM,
       ExtraArgTs... ExtraArgs) = 0;
 
   /// Polymorphic method to access the name of a pass.
-  virtual StringRef name() = 0;
+  virtual StringRef name() const = 0;
 };
 
 /// Wrapper to model the analysis pass concept.
 ///
 /// Can wrap any type which implements a suitable \c run method. The method
 /// must accept an \c IRUnitT& and an \c AnalysisManager<IRUnitT>& as arguments
 /// and produce an object which can be wrapped in a \c AnalysisResultModel.
 template <typename IRUnitT, typename PassT, typename PreservedAnalysesT,
struct AnalysisPassModel : AnalysisPassConcept<IRUnitT, PreservedAnalysesT,
 
   /// The model delegates to the \c PassT::run method.
   ///
   /// The return is wrapped in an \c AnalysisResultModel.
   std::unique_ptr<
       AnalysisResultConcept<IRUnitT, PreservedAnalysesT, InvalidatorT>>
   run(IRUnitT &IR, AnalysisManager<IRUnitT, ExtraArgTs...> &AM,
       ExtraArgTs... ExtraArgs) override {
-    return llvm::make_unique<ResultModelT>(Pass.run(IR, AM, ExtraArgs...));
+    return llvm::make_unique<ResultModelT>(
+        Pass.run(IR, AM, std::forward<ExtraArgTs>(ExtraArgs)...));
   }
 
   /// The model delegates to a static \c PassT::name method.
   ///
   /// The returned string ref must point to constant immutable data!
-  StringRef name() override { return PassT::name(); }
+  StringRef name() const override { return PassT::name(); }
 
   PassT Pass;
 };
 
 } // end namespace detail
 
 } // end namespace llvm
 
 #endif // LLVM_IR_PASSMANAGERINTERNAL_H

include/llvm/Passes/PassBuilder.h

 ///
 /// It's members provide the baseline state available to passes during their
 /// construction. The \c PassRegistry.def file specifies how to construct all
 /// of the built-in passes, and those may reference these members during
 /// construction.
 class PassBuilder {
   TargetMachine *TM;
   Optional<PGOOptions> PGOOpt;
+  PassInstrumentationCallbacks *PIC;
+
+  PassInstrumentationCallbacks *getPassInstrumentationCallbacks() const {
+    return PIC;
+  }
 
 public:
   /// A struct to capture parsed pass pipeline names.
   ///
   /// A pipeline is defined as a series of names, each of which may in itself
   /// recursively contain a nested pipeline. A name is either the name of a pass
   /// (e.g. "instcombine") or the name of a pipeline type (e.g. "cgscc"). If the
   /// name is the name of a pass, the InnerPipeline is empty, since passes
enum OptimizationLevel {
     /// This is useful primarily when there are absolute size limitations and
     /// any effort taken to reduce the size is worth it regardless of the
     /// execution time impact. You should expect this level to produce rather
     /// slow, but very small, code.
     Oz
   };
 
   explicit PassBuilder(TargetMachine *TM = nullptr,
-                       Optional<PGOOptions> PGOOpt = None)
-      : TM(TM), PGOOpt(PGOOpt) {}
+                       Optional<PGOOptions> PGOOpt = None,
+                       PassInstrumentationCallbacks *PIC = nullptr)
+      : TM(TM), PGOOpt(PGOOpt), PIC(PIC) {}
 
   /// Cross register the analysis managers through their proxies.
   ///
   /// This is an interface that can be used to cross register each
   // AnalysisManager with all the others analysis managers.
   void crossRegisterProxies(LoopAnalysisManager &LAM,
                             FunctionAnalysisManager &FAM,
                             CGSCCAnalysisManager &CGAM,
public:
   /// text, this Callback should be used to determine the appropriate stack of
   /// PassManagers and populate the passed ModulePassManager.
   void registerParseTopLevelPipelineCallback(
       const std::function<bool(ModulePassManager &, ArrayRef<PipelineElement>,
                                bool VerifyEachPass, bool DebugLogging)> &C) {
     TopLevelPipelineParsingCallbacks.push_back(C);
   }
 
+  /// Calls registration function \p C on PassInstrumentationCallbacks object
+  /// to register pass instrumentation callbacks there.
+  ///
+  /// \Returns false if there is no pass instrumentation object available.
+  bool registerPassInstrumentation(
+      const std::function<void(PassInstrumentationCallbacks &)> &C) {
+    if (!PIC)
+      return false;
+    C(*PIC);
+    return true;
+  }
+
 private:
   static Optional<std::vector<PipelineElement>>
   parsePipelineText(StringRef Text);
 
   bool parseModulePass(ModulePassManager &MPM, const PipelineElement &E,
                        bool VerifyEachPass, bool DebugLogging);
   bool parseCGSCCPass(CGSCCPassManager &CGPM, const PipelineElement &E,
                       bool VerifyEachPass, bool DebugLogging);

include/llvm/Transforms/Scalar/LoopPassManager.h

public:
   }
 
   /// Runs the loop passes across every loop in the function.
   PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM) {
     // Before we even compute any loop analyses, first run a miniature function
     // pass pipeline to put loops into their canonical form. Note that we can
     // directly build up function analyses after this as the function pass
     // manager handles all the invalidation at that layer.
-    PreservedAnalyses PA = LoopCanonicalizationFPM.run(F, AM);
+    PassInstrumentation PI = AM.getResult<PassInstrumentationAnalysis>(F);
+
+    PreservedAnalyses PA = PreservedAnalyses::all();
+    // Check the PassInstrumentation's BeforePass callbacks before running the
+    // canonicalization pipeline.
+    if (PI.runBeforePass<Function>(LoopCanonicalizationFPM, F)) {
+      PA = LoopCanonicalizationFPM.run(F, AM);
+      PI.runAfterPass<Function>(LoopCanonicalizationFPM, F);
+    }
 
     // Get the loop structure for this function
     LoopInfo &LI = AM.getResult<LoopAnalysis>(F);
 
     // If there are no loops, there is nothing to do here.
     if (LI.empty())
       return PA;
 
#ifndef NDEBUG
       // Save a parent loop pointer for asserts.
       Updater.ParentL = L->getParentLoop();
 
       // Verify the loop structure and LCSSA form before visiting the loop.
       L->verifyLoop();
       assert(L->isRecursivelyLCSSAForm(LAR.DT, LI) &&
              "Loops must remain in LCSSA form!");
 #endif
-
+      // Check the PassInstrumentation's BeforePass callbacks before running the
+      // pass, skip its execution completely if asked to (callback returns
+      // false).
+      if (!PI.runBeforePass<Loop>(Pass, *L))
+        continue;
       PreservedAnalyses PassPA = Pass.run(*L, LAM, LAR, Updater);
+
+      PI.runAfterPass<Loop>(Pass, *L);
+
       // FIXME: We should verify the set of analyses relevant to Loop passes
       // are preserved.
 
       // If the loop hasn't been deleted, we need to handle invalidation here.
       if (!Updater.skipCurrentLoop())
         // We know that the loop pass couldn't have invalidated any other
         // loop's analyses (that's the contract of a loop pass), so directly
         // handle the loop analysis manager's invalidation here.

lib/Analysis/CGSCCPassManager.cpp

 /// Explicitly specialize the pass manager run method to handle call graph
 /// updates.
 template <>
 PreservedAnalyses
 PassManager<LazyCallGraph::SCC, CGSCCAnalysisManager, LazyCallGraph &,
             CGSCCUpdateResult &>::run(LazyCallGraph::SCC &InitialC,
                                       CGSCCAnalysisManager &AM,
                                       LazyCallGraph &G, CGSCCUpdateResult &UR) {
+  // Request PassInstrumentation from analysis manager, will use it to run
+  // instrumenting callbacks for the passes later.
+  PassInstrumentation PI =
+      AM.getResult<PassInstrumentationAnalysis>(InitialC, G);
+
   PreservedAnalyses PA = PreservedAnalyses::all();
 
   if (DebugLogging)
     dbgs() << "Starting CGSCC pass manager run.\n";
 
   // The SCC may be refined while we are running passes over it, so set up
   // a pointer that we can update.
   LazyCallGraph::SCC *C = &InitialC;
 
   for (auto &Pass : Passes) {
     if (DebugLogging)
       dbgs() << "Running pass: " << Pass->name() << " on " << *C << "\n";
 
+    // Check the PassInstrumentation's BeforePass callbacks before running the
+    // pass, skip its execution completely if asked to (callback returns false).
+    if (!PI.runBeforePass(*Pass, *C))
+      continue;
+
     PreservedAnalyses PassPA = Pass->run(*C, AM, G, UR);
 
+    PI.runAfterPass(*Pass, *C);
+
     // Update the SCC if necessary.
     C = UR.UpdatedC ? UR.UpdatedC : C;
 
     // If the CGSCC pass wasn't able to provide a valid updated SCC, the
     // current SCC may simply need to be skipped if invalid.
     if (UR.InvalidatedSCCs.count(C)) {
       LLVM_DEBUG(dbgs() << "Skipping invalidated root or island SCC!\n");
       break;

lib/FuzzMutate/IRMutator.cpp

void IRMutator::mutateModule(Module &M, int Seed, size_t CurSize,
   Strategy->mutate(M, IB);
 }
 
 static void eliminateDeadCode(Function &F) {
   FunctionPassManager FPM;
   FPM.addPass(DCEPass());
   FunctionAnalysisManager FAM;
   FAM.registerPass([&] { return TargetLibraryAnalysis(); });
+  FAM.registerPass([&] { return PassInstrumentationAnalysis(); });
   FPM.run(F, FAM);
 }
 
 void InjectorIRStrategy::mutate(Function &F, RandomIRBuilder &IB) {
   IRMutationStrategy::mutate(F, IB);
   eliminateDeadCode(F);
 }
 

lib/IR/CMakeLists.txt

add_llvm_library(LLVMCore
   MDBuilder.cpp
   Mangler.cpp
   Metadata.cpp
   Module.cpp
   ModuleSummaryIndex.cpp
   Operator.cpp
   OptBisect.cpp
   Pass.cpp
+  PassInstrumentation.cpp
   PassManager.cpp
   PassRegistry.cpp
   PassTimingInfo.cpp
   SafepointIRVerifier.cpp
   ProfileSummary.cpp
   Statepoint.cpp
   Type.cpp
   TypeFinder.cpp

lib/IR/PassInstrumentation.cpp

+//===- PassInstrumentation.cpp - Pass Instrumentation interface -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+///
+/// This file provides the implementation of PassInstrumentation class.
+///
+//===----------------------------------------------------------------------===//
+
+#include "llvm/IR/PassInstrumentation.h"
+#include "llvm/Analysis/LazyCallGraph.h"
+#include "llvm/Analysis/LoopInfo.h"
+#include "llvm/IR/PassManager.h"
+
+namespace llvm {
+
+template <typename IRUnitT>
+bool PassInstrumentationCallbacks::runBeforePass(StringRef PassID,
+                                                 const IRUnitT &IR) const {
+  bool shouldRun = true;
+  for (auto &C : BeforePassCallbacks)
+    shouldRun &= C(PassID, llvm::Any(&IR));
+  return shouldRun;
+}
+
+template <typename IRUnitT>
+void PassInstrumentationCallbacks::runAfterPass(StringRef PassID,
+                                                const IRUnitT &IR) const {
+  for (auto &C : AfterPassCallbacks)
+    C(PassID, llvm::Any(&IR));
+}
+
+template bool
+PassInstrumentationCallbacks::runBeforePass(StringRef PassID,
+                                            const Module &IR) const;
+template bool
+PassInstrumentationCallbacks::runBeforePass(StringRef PassID,
+                                            const Function &IR) const;
+template bool PassInstrumentationCallbacks::runBeforePass(StringRef PassID,
+                                                          const Loop &IR) const;
+template bool
+PassInstrumentationCallbacks::runBeforePass(StringRef PassID,
+                                            const LazyCallGraph::SCC &IR) const;
+template void
+PassInstrumentationCallbacks::runAfterPass(StringRef PassID,
+                                           const Module &IR) const;
+template void
+PassInstrumentationCallbacks::runAfterPass(StringRef PassID,
+                                           const Function &IR) const;
+template void PassInstrumentationCallbacks::runAfterPass(StringRef PassID,
+                                                         const Loop &IR) const;
+template void
+PassInstrumentationCallbacks::runAfterPass(StringRef PassID,
+                                           const LazyCallGraph::SCC &IR) const;
+
+AnalysisKey PassInstrumentationAnalysis::Key;
+
+} // namespace llvm

lib/Passes/PassBuilder.cpp

for (auto &C : PeepholeEPCallbacks)
     C(FPM, Level);
 }
 
 void PassBuilder::registerModuleAnalyses(ModuleAnalysisManager &MAM) {
 #define MODULE_ANALYSIS(NAME, CREATE_PASS)                                     \
   MAM.registerPass([&] { return CREATE_PASS; });
 #include "PassRegistry.def"
 
+  MAM.registerPass([&] {
+    return PassInstrumentationAnalysis(this->getPassInstrumentationCallbacks());
+  });
+
   for (auto &C : ModuleAnalysisRegistrationCallbacks)
     C(MAM);
 }
 
 void PassBuilder::registerCGSCCAnalyses(CGSCCAnalysisManager &CGAM) {
 #define CGSCC_ANALYSIS(NAME, CREATE_PASS)                                      \
   CGAM.registerPass([&] { return CREATE_PASS; });
 #include "PassRegistry.def"
 
+  CGAM.registerPass([&] {
+    return PassInstrumentationAnalysis(this->getPassInstrumentationCallbacks());
+  });
+
   for (auto &C : CGSCCAnalysisRegistrationCallbacks)
     C(CGAM);
 }
 
 void PassBuilder::registerFunctionAnalyses(FunctionAnalysisManager &FAM) {
 #define FUNCTION_ANALYSIS(NAME, CREATE_PASS)                                   \
   FAM.registerPass([&] { return CREATE_PASS; });
 #include "PassRegistry.def"
 
+  FAM.registerPass([&] {
+    return PassInstrumentationAnalysis(this->getPassInstrumentationCallbacks());
+  });
+
   for (auto &C : FunctionAnalysisRegistrationCallbacks)
     C(FAM);
 }
 
 void PassBuilder::registerLoopAnalyses(LoopAnalysisManager &LAM) {
 #define LOOP_ANALYSIS(NAME, CREATE_PASS)                                       \
   LAM.registerPass([&] { return CREATE_PASS; });
 #include "PassRegistry.def"
 
+  LAM.registerPass([&] {
+    return PassInstrumentationAnalysis(this->getPassInstrumentationCallbacks());
+  });
+
   for (auto &C : LoopAnalysisRegistrationCallbacks)
     C(LAM);
 }
 
 FunctionPassManager
 PassBuilder::buildFunctionSimplificationPipeline(OptimizationLevel Level,
                                                  ThinLTOPhase Phase,
                                                  bool DebugLogging) {

lib/Transforms/Scalar/LoopPassManager.cpp

 PassManager<Loop, LoopAnalysisManager, LoopStandardAnalysisResults &,
             LPMUpdater &>::run(Loop &L, LoopAnalysisManager &AM,
                                LoopStandardAnalysisResults &AR, LPMUpdater &U) {
   PreservedAnalyses PA = PreservedAnalyses::all();
 
   if (DebugLogging)
     dbgs() << "Starting Loop pass manager run.\n";
 
+  // Request PassInstrumentation from analysis manager, will use it to run
+  // instrumenting callbacks for the passes later.
+  PassInstrumentation PI = AM.getResult<PassInstrumentationAnalysis>(L, AR);
   for (auto &Pass : Passes) {
     if (DebugLogging)
       dbgs() << "Running pass: " << Pass->name() << " on " << L;
 
+    // Check the PassInstrumentation's BeforePass callbacks before running the
+    // pass, skip its execution completely if asked to (callback returns false).
+    if (!PI.runBeforePass<Loop>(*Pass, L))
+      continue;
+
     PreservedAnalyses PassPA = Pass->run(L, AM, AR, U);
 
+    PI.runAfterPass<Loop>(*Pass, L);
+
     // If the loop was deleted, abort the run and return to the outer walk.
     if (U.skipCurrentLoop()) {
       PA.intersect(std::move(PassPA));
       break;
     }
 
 #ifndef NDEBUG
     // Verify the loop structure and LCSSA form before visiting the loop.

test/Other/loop-pm-invalidation.ll

 ; CHECK-LOOP-INV-NEXT: Running pass: LCSSAPass
 ; CHECK-LOOP-INV-NEXT: Finished {{.*}}Function pass manager run
 ; CHECK-LOOP-INV-NEXT: Running analysis: AAManager
 ; CHECK-LOOP-INV-NEXT: Running analysis: TargetLibraryAnalysis
 ; CHECK-LOOP-INV-NEXT: Running analysis: ScalarEvolutionAnalysis
 ; CHECK-LOOP-INV-NEXT: Running analysis: TargetIRAnalysis
 ; CHECK-LOOP-INV-NEXT: Running analysis: InnerAnalysisManagerProxy<{{.*}}Loop
 ; CHECK-LOOP-INV-NEXT: Starting {{.*}}Loop pass manager run.
+; CHECK-LOOP-INV-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-LOOP-INV-NEXT: Running pass: NoOpLoopPass
 ; CHECK-LOOP-INV-NEXT: Finished {{.*}}Loop pass manager run.
 ; CHECK-LOOP-INV-NEXT: Running pass: InvalidateAnalysisPass<{{.*}}LoopAnalysis
 ; CHECK-LOOP-INV-NEXT: Invalidating all non-preserved analyses
 ; CHECK-LOOP-INV-NEXT: Clearing all analysis results for: <possibly invalidated loop>
 ; CHECK-LOOP-INV-NEXT: Invalidating analysis: LoopAnalysis
 ; CHECK-LOOP-INV-NEXT: Invalidating analysis: ScalarEvolutionAnalysis
 ; CHECK-LOOP-INV-NEXT: Invalidating analysis: InnerAnalysisManagerProxy<{{.*}}Loop
 ; CHECK-LOOP-INV-NEXT: Running pass: FunctionToLoopPassAdaptor<{{.*}}> on one_loop
 ; CHECK-LOOP-INV-NEXT: Starting {{.*}}Function pass manager run
 ; CHECK-LOOP-INV-NEXT: Running pass: LoopSimplifyPass
 ; CHECK-LOOP-INV-NEXT: Running analysis: LoopAnalysis
 ; CHECK-LOOP-INV-NEXT: Running pass: LCSSAPass
 ; CHECK-LOOP-INV-NEXT: Finished {{.*}}Function pass manager run
 ; CHECK-LOOP-INV-NEXT: Running analysis: ScalarEvolutionAnalysis
 ; CHECK-LOOP-INV-NEXT: Running analysis: InnerAnalysisManagerProxy<{{.*}}Loop
 ; CHECK-LOOP-INV-NEXT: Starting {{.*}}Loop pass manager run.
+; CHECK-LOOP-INV-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-LOOP-INV-NEXT: Running pass: NoOpLoopPass
 ; CHECK-LOOP-INV-NEXT: Finished {{.*}}Loop pass manager run.
 ; CHECK-LOOP-INV-NEXT: Finished {{.*}}Function pass manager run.
 ;
 ; CHECK-SCEV-INV-LABEL: Running pass: FunctionToLoopPassAdaptor<{{.*}}> on one_loop
 ; CHECK-SCEV-INV-NEXT: Starting {{.*}}Function pass manager run
 ; CHECK-SCEV-INV-NEXT: Running pass: LoopSimplifyPass
 ; CHECK-SCEV-INV-NEXT: Running analysis: LoopAnalysis
 ; CHECK-SCEV-INV-NEXT: Running analysis: DominatorTreeAnalysis
 ; CHECK-SCEV-INV-NEXT: Running analysis: AssumptionAnalysis
 ; CHECK-SCEV-INV-NEXT: Running pass: LCSSAPass
 ; CHECK-SCEV-INV-NEXT: Finished {{.*}}Function pass manager run
 ; CHECK-SCEV-INV-NEXT: Running analysis: AAManager
 ; CHECK-SCEV-INV-NEXT: Running analysis: TargetLibraryAnalysis
 ; CHECK-SCEV-INV-NEXT: Running analysis: ScalarEvolutionAnalysis
 ; CHECK-SCEV-INV-NEXT: Running analysis: TargetIRAnalysis
 ; CHECK-SCEV-INV-NEXT: Running analysis: InnerAnalysisManagerProxy<{{.*}}Loop
 ; CHECK-SCEV-INV-NEXT: Starting {{.*}}Loop pass manager run.
+; CHECK-SCEV-INV-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-SCEV-INV-NEXT: Running pass: NoOpLoopPass
 ; CHECK-SCEV-INV-NEXT: Finished {{.*}}Loop pass manager run.
 ; CHECK-SCEV-INV-NEXT: Running pass: InvalidateAnalysisPass<{{.*}}ScalarEvolutionAnalysis
 ; CHECK-SCEV-INV-NEXT: Invalidating all non-preserved analyses
 ; CHECK-SCEV-INV-NEXT: Clearing all analysis results for: <possibly invalidated loop>
 ; CHECK-SCEV-INV-NEXT: Invalidating analysis: ScalarEvolutionAnalysis
 ; CHECK-SCEV-INV-NEXT: Invalidating analysis: InnerAnalysisManagerProxy<{{.*}}Loop
 ; CHECK-SCEV-INV-NEXT: Running pass: FunctionToLoopPassAdaptor<{{.*}}> on one_loop
 ; CHECK-SCEV-INV-NEXT: Starting {{.*}}Function pass manager run
 ; CHECK-SCEV-INV-NEXT: Running pass: LoopSimplifyPass
 ; CHECK-SCEV-INV-NEXT: Running pass: LCSSAPass
 ; CHECK-SCEV-INV-NEXT: Finished {{.*}}Function pass manager run
 ; CHECK-SCEV-INV-NEXT: Running analysis: ScalarEvolutionAnalysis
 ; CHECK-SCEV-INV-NEXT: Running analysis: InnerAnalysisManagerProxy<{{.*}}Loop
 ; CHECK-SCEV-INV-NEXT: Starting {{.*}}Loop pass manager run.
+; CHECK-SCEV-INV-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-SCEV-INV-NEXT: Running pass: NoOpLoopPass
 ; CHECK-SCEV-INV-NEXT: Finished {{.*}}Loop pass manager run.
 ; CHECK-SCEV-INV-NEXT: Finished {{.*}}Function pass manager run.
 
 entry:
   br label %l0.header
 
 l0.header:

 ; CHECK-LOOP-INV-NEXT: Running pass: LCSSAPass
 ; CHECK-LOOP-INV-NEXT: Finished {{.*}}Function pass manager run
 ; CHECK-LOOP-INV-NEXT: Running analysis: AAManager
 ; CHECK-LOOP-INV-NEXT: Running analysis: TargetLibraryAnalysis
 ; CHECK-LOOP-INV-NEXT: Running analysis: ScalarEvolutionAnalysis
 ; CHECK-LOOP-INV-NEXT: Running analysis: TargetIRAnalysis
 ; CHECK-LOOP-INV-NEXT: Running analysis: InnerAnalysisManagerProxy<{{.*}}Loop
 ; CHECK-LOOP-INV-NEXT: Starting {{.*}}Loop pass manager run.
+; CHECK-LOOP-INV-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-LOOP-INV-NEXT: Running pass: NoOpLoopPass
 ; CHECK-LOOP-INV-NEXT: Finished {{.*}}Loop pass manager run.
 ; CHECK-LOOP-INV-NEXT: Starting {{.*}}Loop pass manager run.
+; CHECK-LOOP-INV-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-LOOP-INV-NEXT: Running pass: NoOpLoopPass
 ; CHECK-LOOP-INV: Finished {{.*}}Loop pass manager run.
 ; CHECK-LOOP-INV-NEXT: Running pass: InvalidateAnalysisPass<{{.*}}LoopAnalysis
 ; CHECK-LOOP-INV-NEXT: Invalidating all non-preserved analyses
 ; CHECK-LOOP-INV-NEXT: Clearing all analysis results for: <possibly invalidated loop>
 ; CHECK-LOOP-INV-NEXT: Clearing all analysis results for: <possibly invalidated loop>
 ; CHECK-LOOP-INV-NEXT: Invalidating analysis: LoopAnalysis
 ; CHECK-LOOP-INV-NEXT: Invalidating analysis: ScalarEvolutionAnalysis
 ; CHECK-LOOP-INV-NEXT: Invalidating analysis: InnerAnalysisManagerProxy<{{.*}}Loop
 ; CHECK-LOOP-INV-NEXT: Running pass: FunctionToLoopPassAdaptor<{{.*}}> on nested_loops
 ; CHECK-LOOP-INV-NEXT: Starting {{.*}}Function pass manager run
 ; CHECK-LOOP-INV-NEXT: Running pass: LoopSimplifyPass
 ; CHECK-LOOP-INV-NEXT: Running analysis: LoopAnalysis
 ; CHECK-LOOP-INV-NEXT: Running pass: LCSSAPass
 ; CHECK-LOOP-INV-NEXT: Finished {{.*}}Function pass manager run
 ; CHECK-LOOP-INV-NEXT: Running analysis: ScalarEvolutionAnalysis
 ; CHECK-LOOP-INV-NEXT: Running analysis: InnerAnalysisManagerProxy<{{.*}}Loop
 ; CHECK-LOOP-INV-NEXT: Starting {{.*}}Loop pass manager run.
+; CHECK-LOOP-INV-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-LOOP-INV-NEXT: Running pass: NoOpLoopPass
 ; CHECK-LOOP-INV-NEXT: Finished {{.*}}Loop pass manager run.
 ; CHECK-LOOP-INV-NEXT: Starting {{.*}}Loop pass manager run.
+; CHECK-LOOP-INV-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-LOOP-INV-NEXT: Running pass: NoOpLoopPass
 ; CHECK-LOOP-INV: Finished {{.*}}Loop pass manager run.
 ; CHECK-LOOP-INV-NEXT: Finished {{.*}}Function pass manager run.
 ;
 ; CHECK-SCEV-INV-LABEL: Running pass: FunctionToLoopPassAdaptor<{{.*}}> on nested_loops
 ; CHECK-SCEV-INV-NEXT: Starting {{.*}}Function pass manager run
 ; CHECK-SCEV-INV-NEXT: Running pass: LoopSimplifyPass
 ; CHECK-SCEV-INV-NEXT: Running analysis: LoopAnalysis
 ; CHECK-SCEV-INV-NEXT: Running analysis: DominatorTreeAnalysis
 ; CHECK-SCEV-INV-NEXT: Running analysis: AssumptionAnalysis
 ; CHECK-SCEV-INV-NEXT: Running pass: LCSSAPass
 ; CHECK-SCEV-INV-NEXT: Finished {{.*}}Function pass manager run
 ; CHECK-SCEV-INV-NEXT: Running analysis: AAManager
 ; CHECK-SCEV-INV-NEXT: Running analysis: TargetLibraryAnalysis
 ; CHECK-SCEV-INV-NEXT: Running analysis: ScalarEvolutionAnalysis
 ; CHECK-SCEV-INV-NEXT: Running analysis: TargetIRAnalysis
 ; CHECK-SCEV-INV-NEXT: Running analysis: InnerAnalysisManagerProxy<{{.*}}Loop
 ; CHECK-SCEV-INV-NEXT: Starting {{.*}}Loop pass manager run.
+; CHECK-SCEV-INV-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-SCEV-INV-NEXT: Running pass: NoOpLoopPass
 ; CHECK-SCEV-INV-NEXT: Finished {{.*}}Loop pass manager run.
 ; CHECK-SCEV-INV-NEXT: Starting {{.*}}Loop pass manager run.
+; CHECK-SCEV-INV-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-SCEV-INV-NEXT: Running pass: NoOpLoopPass
 ; CHECK-SCEV-INV: Finished {{.*}}Loop pass manager run.
 ; CHECK-SCEV-INV-NEXT: Running pass: InvalidateAnalysisPass<{{.*}}ScalarEvolutionAnalysis
 ; CHECK-SCEV-INV-NEXT: Invalidating all non-preserved analyses
 ; CHECK-SCEV-INV-NEXT: Clearing all analysis results for: <possibly invalidated loop>
 ; CHECK-SCEV-INV-NEXT: Clearing all analysis results for: <possibly invalidated loop>
 ; CHECK-SCEV-INV-NEXT: Invalidating analysis: ScalarEvolutionAnalysis
 ; CHECK-SCEV-INV-NEXT: Invalidating analysis: InnerAnalysisManagerProxy<{{.*}}Loop
 ; CHECK-SCEV-INV-NEXT: Running pass: FunctionToLoopPassAdaptor<{{.*}}> on nested_loops
 ; CHECK-SCEV-INV-NEXT: Starting {{.*}}Function pass manager run
 ; CHECK-SCEV-INV-NEXT: Running pass: LoopSimplifyPass
 ; CHECK-SCEV-INV-NEXT: Running pass: LCSSAPass
 ; CHECK-SCEV-INV-NEXT: Finished {{.*}}Function pass manager run
 ; CHECK-SCEV-INV-NEXT: Running analysis: ScalarEvolutionAnalysis
 ; CHECK-SCEV-INV-NEXT: Running analysis: InnerAnalysisManagerProxy<{{.*}}Loop
 ; CHECK-SCEV-INV-NEXT: Starting {{.*}}Loop pass manager run.
+; CHECK-SCEV-INV-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-SCEV-INV-NEXT: Running pass: NoOpLoopPass
 ; CHECK-SCEV-INV-NEXT: Finished {{.*}}Loop pass manager run.
 ; CHECK-SCEV-INV-NEXT: Starting {{.*}}Loop pass manager run.
+; CHECK-SCEV-INV-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-SCEV-INV-NEXT: Running pass: NoOpLoopPass
 ; CHECK-SCEV-INV: Finished {{.*}}Loop pass manager run.
 ; CHECK-SCEV-INV-NEXT: Finished {{.*}}Function pass manager run.
 
 entry:
   br label %l.0.header
 
 l.0.header:

 ; CHECK-LOOP-INV-NEXT: Running pass: LCSSAPass
 ; CHECK-LOOP-INV-NEXT: Finished {{.*}}Function pass manager run
 ; CHECK-LOOP-INV-NEXT: Running analysis: AAManager
 ; CHECK-LOOP-INV-NEXT: Running analysis: TargetLibraryAnalysis
 ; CHECK-LOOP-INV-NEXT: Running analysis: ScalarEvolutionAnalysis
 ; CHECK-LOOP-INV-NEXT: Running analysis: TargetIRAnalysis
 ; CHECK-LOOP-INV-NEXT: Running analysis: InnerAnalysisManagerProxy<{{.*}}Loop
 ; CHECK-LOOP-INV-NEXT: Starting {{.*}}Loop pass manager run.
+; CHECK-LOOP-INV-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-LOOP-INV-NEXT: Running pass: NoOpLoopPass
 ; CHECK-LOOP-INV-NEXT: Finished {{.*}}Loop pass manager run.
 ; CHECK-LOOP-INV-NEXT: Running pass: InvalidateAnalysisPass<{{.*}}LoopAnalysis
 ; CHECK-LOOP-INV-NEXT: Invalidating all non-preserved analyses
 ; CHECK-LOOP-INV-NEXT: Clearing all analysis results for: <possibly invalidated loop>
 ; CHECK-LOOP-INV-NEXT: Invalidating analysis: LoopAnalysis
 ; CHECK-LOOP-INV-NEXT: Invalidating analysis: ScalarEvolutionAnalysis
 ; CHECK-LOOP-INV-NEXT: Invalidating analysis: InnerAnalysisManagerProxy<{{.*}}Loop
 ; CHECK-LOOP-INV-NEXT: Running pass: FunctionToLoopPassAdaptor<{{.*}}> on dead_loop
 ; CHECK-LOOP-INV-NEXT: Starting {{.*}}Function pass manager run
 ; CHECK-LOOP-INV-NEXT: Running pass: LoopSimplifyPass
 ; CHECK-LOOP-INV-NEXT: Running analysis: LoopAnalysis
 ; CHECK-LOOP-INV-NEXT: Running pass: LCSSAPass
 ; CHECK-LOOP-INV-NEXT: Finished {{.*}}Function pass manager run
 ; CHECK-LOOP-INV-NEXT: Running analysis: ScalarEvolutionAnalysis
 ; CHECK-LOOP-INV-NEXT: Running analysis: InnerAnalysisManagerProxy<{{.*}}Loop
 ; CHECK-LOOP-INV-NEXT: Starting {{.*}}Loop pass manager run.
+; CHECK-LOOP-INV-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-LOOP-INV-NEXT: Running pass: NoOpLoopPass
 ; CHECK-LOOP-INV-NEXT: Finished {{.*}}Loop pass manager run.
 ; CHECK-LOOP-INV-NEXT: Finished {{.*}}Function pass manager run.
 ;
 ; CHECK-SCEV-INV-LABEL: Running pass: FunctionToLoopPassAdaptor<{{.*}}> on dead_loop
 ; CHECK-SCEV-INV-NEXT: Starting {{.*}}Function pass manager run
 ; CHECK-SCEV-INV-NEXT: Running pass: LoopSimplifyPass
 ; CHECK-SCEV-INV-NEXT: Running analysis: LoopAnalysis
 ; CHECK-SCEV-INV-NEXT: Running analysis: DominatorTreeAnalysis
 ; CHECK-SCEV-INV-NEXT: Running analysis: AssumptionAnalysis
 ; CHECK-SCEV-INV-NEXT: Running pass: LCSSAPass
 ; CHECK-SCEV-INV-NEXT: Finished {{.*}}Function pass manager run
 ; CHECK-SCEV-INV-NEXT: Running analysis: AAManager
 ; CHECK-SCEV-INV-NEXT: Running analysis: TargetLibraryAnalysis
 ; CHECK-SCEV-INV-NEXT: Running analysis: ScalarEvolutionAnalysis
 ; CHECK-SCEV-INV-NEXT: Running analysis: TargetIRAnalysis
 ; CHECK-SCEV-INV-NEXT: Running analysis: InnerAnalysisManagerProxy<{{.*}}Loop
 ; CHECK-SCEV-INV-NEXT: Starting {{.*}}Loop pass manager run.
+; CHECK-SCEV-INV-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-SCEV-INV-NEXT: Running pass: NoOpLoopPass
 ; CHECK-SCEV-INV-NEXT: Finished {{.*}}Loop pass manager run.
 ; CHECK-SCEV-INV-NEXT: Running pass: InvalidateAnalysisPass<{{.*}}ScalarEvolutionAnalysis
 ; CHECK-SCEV-INV-NEXT: Invalidating all non-preserved analyses
 ; CHECK-SCEV-INV-NEXT: Clearing all analysis results for: <possibly invalidated loop>
 ; CHECK-SCEV-INV-NEXT: Invalidating analysis: ScalarEvolutionAnalysis
 ; CHECK-SCEV-INV-NEXT: Invalidating analysis: InnerAnalysisManagerProxy<{{.*}}Loop
 ; CHECK-SCEV-INV-NEXT: Running pass: FunctionToLoopPassAdaptor<{{.*}}> on dead_loop
 ; CHECK-SCEV-INV-NEXT: Starting {{.*}}Function pass manager run
 ; CHECK-SCEV-INV-NEXT: Running pass: LoopSimplifyPass
 ; CHECK-SCEV-INV-NEXT: Running pass: LCSSAPass
 ; CHECK-SCEV-INV-NEXT: Finished {{.*}}Function pass manager run
 ; CHECK-SCEV-INV-NEXT: Running analysis: ScalarEvolutionAnalysis
 ; CHECK-SCEV-INV-NEXT: Running analysis: InnerAnalysisManagerProxy<{{.*}}Loop
 ; CHECK-SCEV-INV-NEXT: Starting {{.*}}Loop pass manager run.
+; CHECK-SCEV-INV-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-SCEV-INV-NEXT: Running pass: NoOpLoopPass
 ; CHECK-SCEV-INV-NEXT: Finished {{.*}}Loop pass manager run.
 ; CHECK-SCEV-INV-NEXT: Finished {{.*}}Function pass manager run.
 ;
 ; CHECK-SCEV-INV-AFTER-DELETE-LABEL: Running pass: FunctionToLoopPassAdaptor<{{.*}}> on dead_loop
 ; CHECK-SCEV-INV-AFTER-DELETE-NEXT: Starting {{.*}}Function pass manager run
 ; CHECK-SCEV-INV-AFTER-DELETE-NEXT: Running pass: LoopSimplifyPass
 ; CHECK-SCEV-INV-AFTER-DELETE-NEXT: Running analysis: LoopAnalysis
 ; CHECK-SCEV-INV-AFTER-DELETE-NEXT: Running analysis: DominatorTreeAnalysis
 ; CHECK-SCEV-INV-AFTER-DELETE-NEXT: Running analysis: AssumptionAnalysis
 ; CHECK-SCEV-INV-AFTER-DELETE-NEXT: Running pass: LCSSAPass
 ; CHECK-SCEV-INV-AFTER-DELETE-NEXT: Finished {{.*}}Function pass manager run
 ; CHECK-SCEV-INV-AFTER-DELETE-NEXT: Running analysis: AAManager
 ; CHECK-SCEV-INV-AFTER-DELETE-NEXT: Running analysis: TargetLibraryAnalysis
 ; CHECK-SCEV-INV-AFTER-DELETE-NEXT: Running analysis: ScalarEvolutionAnalysis
 ; CHECK-SCEV-INV-AFTER-DELETE-NEXT: Running analysis: TargetIRAnalysis
 ; CHECK-SCEV-INV-AFTER-DELETE-NEXT: Running analysis: InnerAnalysisManagerProxy<{{.*}}Loop
 ; CHECK-SCEV-INV-AFTER-DELETE-NEXT: Starting {{.*}}Loop pass manager run.
+; CHECK-SCEV-INV-AFTER-DELETE-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-SCEV-INV-AFTER-DELETE-NEXT: Running pass: NoOpLoopPass
 ; CHECK-SCEV-INV-AFTER-DELETE-NEXT: Running pass: LoopDeletionPass
 ; CHECK-SCEV-INV-AFTER-DELETE-NEXT: Clearing all analysis results for:
 ; CHECK-SCEV-INV-AFTER-DELETE-NEXT: Finished {{.*}}Loop pass manager run.
 ; CHECK-SCEV-INV-AFTER-DELETE-NEXT: Invalidating all non-preserved analyses
 ; CHECK-SCEV-INV-AFTER-DELETE-NEXT: Running pass: InvalidateAnalysisPass<{{.*}}ScalarEvolutionAnalysis
 ; CHECK-SCEV-INV-AFTER-DELETE-NEXT: Invalidating all non-preserved analyses
 ; CHECK-SCEV-INV-AFTER-DELETE-NEXT: Invalidating analysis: ScalarEvolutionAnalysis

test/Other/new-pass-manager.ll

 ; RUN:     -passes='cgscc(no-op-cgscc)' %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefix=CHECK-CGSCC-PASS
 ; CHECK-CGSCC-PASS: Starting llvm::Module pass manager run
 ; CHECK-CGSCC-PASS-NEXT: Running pass: ModuleToPostOrderCGSCCPassAdaptor
 ; CHECK-CGSCC-PASS-NEXT: Running analysis: InnerAnalysisManagerProxy<{{.*(CGSCCAnalysisManager|AnalysisManager<.*LazyCallGraph::SCC.*>).*}},{{.*}}Module>
 ; CHECK-CGSCC-PASS-NEXT: Running analysis: InnerAnalysisManagerProxy<{{.*(FunctionAnalysisManager|AnalysisManager<.*Function.*>).*}},{{.*}}Module>
 ; CHECK-CGSCC-PASS-NEXT: Running analysis: LazyCallGraphAnalysis
 ; CHECK-CGSCC-PASS-NEXT: Running analysis: TargetLibraryAnalysis
+; CHECK-CGSCC-PASS-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-CGSCC-PASS-NEXT: Starting CGSCC pass manager run
 ; CHECK-CGSCC-PASS-NEXT: Running pass: NoOpCGSCCPass
 ; CHECK-CGSCC-PASS-NEXT: Finished CGSCC pass manager run
 ; CHECK-CGSCC-PASS-NEXT: Finished llvm::Module pass manager run
 
 ; RUN: opt -disable-output -disable-verify -debug-pass-manager \
 ; RUN:     -passes=no-op-function %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefix=CHECK-FUNCTION-PASS
 ; RUN: opt -disable-output -disable-verify -debug-pass-manager \
 ; RUN:     -passes='function(no-op-function)' %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefix=CHECK-FUNCTION-PASS
 ; CHECK-FUNCTION-PASS: Starting llvm::Module pass manager run
 ; CHECK-FUNCTION-PASS-NEXT: Running pass: ModuleToFunctionPassAdaptor
 ; CHECK-FUNCTION-PASS-NEXT: Running analysis: InnerAnalysisManagerProxy<{{.*}}>
+; CHECK-FUNCTION-PASS-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-FUNCTION-PASS-NEXT: Starting llvm::Function pass manager run
 ; CHECK-FUNCTION-PASS-NEXT: Running pass: NoOpFunctionPass
 ; CHECK-FUNCTION-PASS-NEXT: Finished llvm::Function pass manager run
 ; CHECK-FUNCTION-PASS-NEXT: Finished llvm::Module pass manager run
 
 ; RUN: opt -disable-output -debug-pass-manager -passes=print %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefix=CHECK-MODULE-PRINT
 ; CHECK-MODULE-PRINT: Starting llvm::Module pass manager run

 ; RUN:     -passes='cgscc(repeat<3>(no-op-cgscc))' %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefix=CHECK-REPEAT-CGSCC-PASS
 ; CHECK-REPEAT-CGSCC-PASS: Starting llvm::Module pass manager run
 ; CHECK-REPEAT-CGSCC-PASS-NEXT: Running pass: ModuleToPostOrderCGSCCPassAdaptor
 ; CHECK-REPEAT-CGSCC-PASS-NEXT: Running analysis: InnerAnalysisManagerProxy<{{.*(CGSCCAnalysisManager|AnalysisManager<.*LazyCallGraph::SCC.*>).*}},{{.*}}Module>
 ; CHECK-REPEAT-CGSCC-PASS-NEXT: Running analysis: InnerAnalysisManagerProxy<{{.*(FunctionAnalysisManager|AnalysisManager<.*Function.*>).*}},{{.*}}Module>
 ; CHECK-REPEAT-CGSCC-PASS-NEXT: Running analysis: LazyCallGraphAnalysis
 ; CHECK-REPEAT-CGSCC-PASS-NEXT: Running analysis: TargetLibraryAnalysis
+; CHECK-REPEAT-CGSCC-PASS-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-REPEAT-CGSCC-PASS-NEXT: Starting CGSCC pass manager run
 ; CHECK-REPEAT-CGSCC-PASS-NEXT: Running pass: RepeatedPass
 ; CHECK-REPEAT-CGSCC-PASS-NEXT: Starting CGSCC pass manager run
 ; CHECK-REPEAT-CGSCC-PASS-NEXT: Running pass: NoOpCGSCCPass
 ; CHECK-REPEAT-CGSCC-PASS-NEXT: Finished CGSCC pass manager run
 ; CHECK-REPEAT-CGSCC-PASS-NEXT: Starting CGSCC pass manager run
 ; CHECK-REPEAT-CGSCC-PASS-NEXT: Running pass: NoOpCGSCCPass
 ; CHECK-REPEAT-CGSCC-PASS-NEXT: Finished CGSCC pass manager run
 ; CHECK-REPEAT-CGSCC-PASS-NEXT: Starting CGSCC pass manager run
 ; CHECK-REPEAT-CGSCC-PASS-NEXT: Running pass: NoOpCGSCCPass
 ; CHECK-REPEAT-CGSCC-PASS-NEXT: Finished CGSCC pass manager run
 ; CHECK-REPEAT-CGSCC-PASS-NEXT: Finished CGSCC pass manager run
 ; CHECK-REPEAT-CGSCC-PASS-NEXT: Finished llvm::Module pass manager run
 
 ; RUN: opt -disable-output -disable-verify -debug-pass-manager \
 ; RUN:     -passes='function(repeat<3>(no-op-function))' %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefix=CHECK-REPEAT-FUNCTION-PASS
 ; CHECK-REPEAT-FUNCTION-PASS: Starting llvm::Module pass manager run
 ; CHECK-REPEAT-FUNCTION-PASS-NEXT: Running pass: ModuleToFunctionPassAdaptor
 ; CHECK-REPEAT-FUNCTION-PASS-NEXT: Running analysis: InnerAnalysisManagerProxy<{{.*}}>
+; CHECK-REPEAT-FUNCTION-PASS-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-REPEAT-FUNCTION-PASS-NEXT: Starting llvm::Function pass manager run
 ; CHECK-REPEAT-FUNCTION-PASS-NEXT: Running pass: RepeatedPass
 ; CHECK-REPEAT-FUNCTION-PASS-NEXT: Starting llvm::Function pass manager run
 ; CHECK-REPEAT-FUNCTION-PASS-NEXT: Running pass: NoOpFunctionPass
 ; CHECK-REPEAT-FUNCTION-PASS-NEXT: Finished llvm::Function pass manager run
 ; CHECK-REPEAT-FUNCTION-PASS-NEXT: Starting llvm::Function pass manager run
 ; CHECK-REPEAT-FUNCTION-PASS-NEXT: Running pass: NoOpFunctionPass
 ; CHECK-REPEAT-FUNCTION-PASS-NEXT: Finished llvm::Function pass manager run
 ; CHECK-REPEAT-FUNCTION-PASS-NEXT: Starting llvm::Function pass manager run
 ; CHECK-REPEAT-FUNCTION-PASS-NEXT: Running pass: NoOpFunctionPass
 ; CHECK-REPEAT-FUNCTION-PASS-NEXT: Finished llvm::Function pass manager run
 ; CHECK-REPEAT-FUNCTION-PASS-NEXT: Finished llvm::Function pass manager run
 ; CHECK-REPEAT-FUNCTION-PASS-NEXT: Finished llvm::Module pass manager run
 
 ; RUN: opt -disable-output -disable-verify -debug-pass-manager \
 ; RUN:     -passes='loop(repeat<3>(no-op-loop))' %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefix=CHECK-REPEAT-LOOP-PASS
 ; CHECK-REPEAT-LOOP-PASS: Starting llvm::Module pass manager run
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Running pass: ModuleToFunctionPassAdaptor
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Running analysis: InnerAnalysisManagerProxy<{{.*}}>
+; CHECK-REPEAT-LOOP-PASS-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Starting llvm::Function pass manager run
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Running pass: FunctionToLoopPassAdaptor
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Starting llvm::Function pass manager run
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Running pass: LoopSimplify
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Running analysis: LoopAnalysis
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Running analysis: DominatorTreeAnalysis
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Running analysis: AssumptionAnalysis
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Invalidating all non-preserved analyses
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Running pass: LCSSAPass
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Finished llvm::Function pass manager run
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Running analysis: AAManager
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Running analysis: TargetLibraryAnalysis
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Running analysis: ScalarEvolutionAnalysis
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Running analysis: TargetIRAnalysis
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Running analysis: InnerAnalysisManagerProxy<{{.*}}>
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Starting Loop pass manager run
+; CHECK-REPEAT-LOOP-PASS-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Running pass: RepeatedPass
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Starting Loop pass manager run
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Running pass: NoOpLoopPass
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Finished Loop pass manager run
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Starting Loop pass manager run
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Running pass: NoOpLoopPass
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Finished Loop pass manager run
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Starting Loop pass manager run

test/Other/new-pm-defaults.ll

 ; RUN:     | FileCheck %s --check-prefix=CHECK-O --check-prefix=CHECK-O3 \
 ; RUN:     --check-prefix=CHECK-EP-PIPELINE-START
 ; RUN: opt -disable-verify -debug-pass-manager \
 ; RUN:     -passes-ep-pipeline-start='no-op-module' \
 ; RUN:     -passes='lto-pre-link<O3>' -S  %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefix=CHECK-O --check-prefix=CHECK-O3 \
 ; RUN:     --check-prefix=CHECK-EP-PIPELINE-START
 
-; CHECK-O: Starting llvm::Module pass manager run.
+; CHECK-O: Running analysis: PassInstrumentationAnalysis
+; CHECK-O-NEXT: Starting llvm::Module pass manager run.
 ; CHECK-O-NEXT: Running pass: PassManager<{{.*}}Module{{.*}}>
 ; CHECK-O-NEXT: Starting llvm::Module pass manager run.
 ; CHECK-O-NEXT: Running pass: ForceFunctionAttrsPass
 ; CHECK-EP-PIPELINE-START-NEXT: Running pass: NoOpModulePass
 ; CHECK-O-NEXT: Running pass: PassManager<{{.*}}Module{{.*}}>
 ; CHECK-O-NEXT: Starting llvm::Module pass manager run.
 ; CHECK-O-NEXT: Running pass: InferFunctionAttrsPass
 ; CHECK-O-NEXT: Running analysis: TargetLibraryAnalysis
 ; CHECK-O-NEXT: Running pass: ModuleToFunctionPassAdaptor<{{.*}}PassManager{{.*}}>
 ; CHECK-O-NEXT: Running analysis: InnerAnalysisManagerProxy
+; CHECK-O-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-O-NEXT: Starting llvm::Function pass manager run.
 ; CHECK-O-NEXT: Running pass: SimplifyCFGPass
 ; CHECK-O-NEXT: Running analysis: TargetIRAnalysis
 ; CHECK-O-NEXT: Running analysis: AssumptionAnalysis
 ; CHECK-O-NEXT: Running pass: SROA
 ; CHECK-O-NEXT: Running analysis: DominatorTreeAnalysis
 ; CHECK-O-NEXT: Running pass: EarlyCSEPass
 ; CHECK-O-NEXT: Running analysis: TargetLibraryAnalysis

 ; CHECK-O-NEXT: Running pass: RequireAnalysisPass<{{.*}}GlobalsAA
 ; CHECK-O-NEXT: Running analysis: GlobalsAA
 ; CHECK-O-NEXT: Running analysis: CallGraphAnalysis
 ; CHECK-O-NEXT: Running pass: RequireAnalysisPass<{{.*}}ProfileSummaryAnalysis
 ; CHECK-O-NEXT: Running analysis: ProfileSummaryAnalysis
 ; CHECK-O-NEXT: Running pass: ModuleToPostOrderCGSCCPassAdaptor<{{.*}}LazyCallGraph{{.*}}>
 ; CHECK-O-NEXT: Running analysis: InnerAnalysisManagerProxy
 ; CHECK-O-NEXT: Running analysis: LazyCallGraphAnalysis
+; CHECK-O-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-O-NEXT: Starting CGSCC pass manager run.
 ; CHECK-O-NEXT: Running pass: InlinerPass
 ; CHECK-O-NEXT: Running analysis: OuterAnalysisManagerProxy<{{.*}}LazyCallGraph{{.*}}>
 ; CHECK-O-NEXT: Running analysis: FunctionAnalysisManagerCGSCCProxy
 ; CHECK-O-NEXT: Running pass: PostOrderFunctionAttrsPass
 ; CHECK-O3-NEXT: Running pass: ArgumentPromotionPass
 ; CHECK-O-NEXT: Running pass: CGSCCToFunctionPassAdaptor<{{.*}}PassManager{{.*}}>
 ; CHECK-O-NEXT: Starting llvm::Function pass manager run.

 ; CHECK-O-NEXT: Starting llvm::Function pass manager run.
 ; CHECK-O-NEXT: Running pass: LoopSimplifyPass
 ; CHECK-O-NEXT: Running analysis: LoopAnalysis
 ; CHECK-O-NEXT: Running pass: LCSSAPass
 ; CHECK-O-NEXT: Finished llvm::Function pass manager run.
 ; CHECK-O-NEXT: Running analysis: ScalarEvolutionAnalysis
 ; CHECK-O-NEXT: Running analysis: InnerAnalysisManagerProxy
 ; CHECK-O-NEXT: Starting Loop pass manager run.
+; CHECK-O-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-O-NEXT: Running pass: LoopInstSimplifyPass
 ; CHECK-O-NEXT: Running pass: LoopSimplifyCFGPass
 ; CHECK-O-NEXT: Running pass: LoopRotatePass
 ; CHECK-O-NEXT: Running pass: LICM
 ; CHECK-O-NEXT: Running analysis: OuterAnalysisManagerProxy
 ; CHECK-O-NEXT: Running pass: SimpleLoopUnswitchPass
 ; CHECK-O-NEXT: Finished Loop pass manager run.
 ; CHECK-O-NEXT: Running pass: SimplifyCFGPass

test/Other/new-pm-lto-defaults.ll

 ; RUN: opt -disable-verify -debug-pass-manager \
 ; RUN:     -passes='lto<Oz>' -S %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefix=CHECK-O --check-prefix=CHECK-O2
 ; RUN: opt -disable-verify -debug-pass-manager \
 ; RUN:     -passes='lto<O3>' -S  %s -passes-ep-peephole='no-op-function' 2>&1 \
 ; RUN:     | FileCheck %s --check-prefix=CHECK-O --check-prefix=CHECK-O2 \
 ; RUN:     --check-prefix=CHECK-O3 --check-prefix=CHECK-EP-Peephole
 
-; CHECK-O: Starting llvm::Module pass manager run.
+; CHECK-O: Running analysis: PassInstrumentationAnalysis
+; CHECK-O-NEXT: Starting llvm::Module pass manager run.
 ; CHECK-O-NEXT: Running pass: PassManager<{{.*}}Module
 ; CHECK-O-NEXT: Starting llvm::Module pass manager run.
 ; CHECK-O-NEXT: Running pass: GlobalDCEPass
 ; CHECK-O-NEXT: Running pass: ForceFunctionAttrsPass
 ; CHECK-O-NEXT: Running pass: InferFunctionAttrsPass
 ; CHECK-O-NEXT: Running analysis: TargetLibraryAnalysis
 ; CHECK-O2-NEXT: Running pass: ModuleToFunctionPassAdaptor<{{.*}}PassManager{{.*}}>
 ; CHECK-O2-NEXT: Running analysis: InnerAnalysisManagerProxy<{{.*}}Module
+; CHECK-O2-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-O2-NEXT: Starting llvm::Function pass manager run.
 ; CHECK-O2-NEXT: Running pass: CallSiteSplittingPass on foo
 ; CHECK-O2-NEXT: Running analysis: TargetLibraryAnalysis on foo
 ; CHECK-O2-NEXT: Running analysis: TargetIRAnalysis on foo
 ; CHECK-O2-NEXT: Finished llvm::Function pass manager run.
 ; CHECK-O2-NEXT: PGOIndirectCallPromotion
 ; CHECK-O2-NEXT: Running analysis: ProfileSummaryAnalysis
 ; CHECK-O2-NEXT: Running analysis: OptimizationRemarkEmitterAnalysis

test/Other/new-pm-thinlto-defaults.ll

 ; RUN:     | FileCheck %s --check-prefixes=CHECK-O,CHECK-Os,CHECK-POSTLINK-O,CHECK-POSTLINK-Os
 ; RUN: opt -disable-verify -debug-pass-manager \
 ; RUN:     -passes='thinlto<Oz>' -S %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefixes=CHECK-O,CHECK-Oz,CHECK-POSTLINK-O,CHECK-POSTLINK-Oz
 ; RUN: opt -disable-verify -debug-pass-manager -new-pm-debug-info-for-profiling \
 ; RUN:     -passes='thinlto<O2>' -S  %s 2>&1 \
 ; RUN:     | FileCheck %s --check-prefixes=CHECK-O,CHECK-O2,CHECK-POSTLINK-O,CHECK-POSTLINK-O2
 ;
-; CHECK-O: Starting llvm::Module pass manager run.
+; CHECK-O: Running analysis: PassInstrumentationAnalysis
+; CHECK-O-NEXT: Starting llvm::Module pass manager run.
 ; CHECK-O-NEXT: Running pass: PassManager<{{.*}}Module{{.*}}>
 ; CHECK-O-NEXT: Starting llvm::Module pass manager run.
 ; CHECK-O-NEXT: Running pass: ForceFunctionAttrsPass
 ; CHECK-EP-PIPELINE-START-NEXT: Running pass: NoOpModulePass
 ; CHECK-DIS-NEXT: Running pass: ModuleToFunctionPassAdaptor<{{.*}}AddDiscriminatorsPass{{.*}}>
 ; CHECK-DIS-NEXT: Running analysis: InnerAnalysisManagerProxy
 ; CHECK-POSTLINK-O-NEXT: Running pass: PGOIndirectCallPromotion
 ; CHECK-POSTLINK-O-NEXT: Running analysis: ProfileSummaryAnalysis
 ; CHECK-POSTLINK-O-NEXT: Running analysis: InnerAnalysisManagerProxy
 ; CHECK-POSTLINK-O-NEXT: Running analysis: OptimizationRemarkEmitterAnalysis
 ; CHECK-O-NEXT: Running pass: PassManager<{{.*}}Module{{.*}}>
 ; CHECK-O-NEXT: Starting llvm::Module pass manager run.
 ; CHECK-O-NEXT: Running pass: InferFunctionAttrsPass
 ; CHECK-O-NEXT: Running analysis: TargetLibraryAnalysis
 ; CHECK-O-NEXT: Running pass: ModuleToFunctionPassAdaptor<{{.*}}PassManager{{.*}}>
 ; CHECK-PRELINK-O-NODIS-NEXT: Running analysis: InnerAnalysisManagerProxy
+; CHECK-O-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-O-NEXT: Starting llvm::Function pass manager run.
 ; CHECK-O-NEXT: Running pass: SimplifyCFGPass
 ; CHECK-O-NEXT: Running analysis: TargetIRAnalysis
 ; CHECK-O-NEXT: Running analysis: AssumptionAnalysis
 ; CHECK-O-NEXT: Running pass: SROA
 ; CHECK-O-NEXT: Running analysis: DominatorTreeAnalysis
 ; CHECK-O-NEXT: Running pass: EarlyCSEPass
 ; CHECK-O-NEXT: Running analysis: TargetLibraryAnalysis

 ; CHECK-O-NEXT: Running pass: RequireAnalysisPass<{{.*}}GlobalsAA
 ; CHECK-O-NEXT: Running analysis: GlobalsAA
 ; CHECK-O-NEXT: Running analysis: CallGraphAnalysis
 ; CHECK-O-NEXT: Running pass: RequireAnalysisPass<{{.*}}ProfileSummaryAnalysis
 ; CHECK-PRELINK-O-NEXT: Running analysis: ProfileSummaryAnalysis
 ; CHECK-O-NEXT: Running pass: ModuleToPostOrderCGSCCPassAdaptor<{{.*}}LazyCallGraph{{.*}}>
 ; CHECK-O-NEXT: Running analysis: InnerAnalysisManagerProxy
 ; CHECK-O-NEXT: Running analysis: LazyCallGraphAnalysis
+; CHECK-O-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-O-NEXT: Starting CGSCC pass manager run.
 ; CHECK-O-NEXT: Running pass: InlinerPass
 ; CHECK-O-NEXT: Running analysis: OuterAnalysisManagerProxy<{{.*}}LazyCallGraph{{.*}}>
 ; CHECK-O-NEXT: Running analysis: FunctionAnalysisManagerCGSCCProxy
 ; CHECK-O-NEXT: Running pass: PostOrderFunctionAttrsPass
 ; CHECK-O3-NEXT: Running pass: ArgumentPromotionPass
 ; CHECK-O-NEXT: Running pass: CGSCCToFunctionPassAdaptor<{{.*}}PassManager{{.*}}>
 ; CHECK-O-NEXT: Starting llvm::Function pass manager run.

 ; CHECK-O-NEXT: Starting llvm::Function pass manager run
 ; CHECK-O-NEXT: Running pass: LoopSimplifyPass
 ; CHECK-O-NEXT: Running analysis: LoopAnalysis
 ; CHECK-O-NEXT: Running pass: LCSSAPass
 ; CHECK-O-NEXT: Finished llvm::Function pass manager run
 ; CHECK-O-NEXT: Running analysis: ScalarEvolutionAnalysis
 ; CHECK-O-NEXT: Running analysis: InnerAnalysisManagerProxy
 ; CHECK-O-NEXT: Starting Loop pass manager run.
+; CHECK-O-NEXT: Running analysis: PassInstrumentationAnalysis
 ; CHECK-O-NEXT: Running pass: LoopInstSimplifyPass
 ; CHECK-O-NEXT: Running pass: LoopSimplifyCFGPass
 ; CHECK-O-NEXT: Running pass: LoopRotatePass
 ; CHECK-O-NEXT: Running pass: LICM
 ; CHECK-O-NEXT: Running analysis: OuterAnalysisManagerProxy
 ; CHECK-O-NEXT: Running pass: SimpleLoopUnswitchPass
 ; CHECK-O-NEXT: Finished Loop pass manager run.
 ; CHECK-O-NEXT: Running pass: SimplifyCFGPass

test/Transforms/Inline/cgscc-incremental-invalidate.ll

 ; CHECK: Invalidating analysis: LoopAnalysis on test1_h
 ; CHECK: Invalidating analysis: BranchProbabilityAnalysis on test1_h
 ; CHECK: Invalidating analysis: BlockFrequencyAnalysis on test1_h
 ; CHECK-NOT: Invalidating analysis:
 ; CHECK: Starting llvm::Function pass manager run.
 ; CHECK-NEXT: Running pass: DominatorTreeVerifierPass on test1_g
 ; CHECK-NEXT: Running analysis: DominatorTreeAnalysis on test1_g
 ; CHECK-NEXT: Finished llvm::Function pass manager run.
-; CHECK-NEXT: Starting llvm::Function pass manager run.
+; CHECK-NOT: Invalidating analysis:
+; CHECK: Starting llvm::Function pass manager run.
 ; CHECK-NEXT: Running pass: DominatorTreeVerifierPass on test1_h
 ; CHECK-NEXT: Running analysis: DominatorTreeAnalysis on test1_h
 ; CHECK-NEXT: Finished llvm::Function pass manager run.
 ; CHECK-NOT: Invalidating analysis:
 ; CHECK: Running pass: DominatorTreeVerifierPass on test1_f
 ; CHECK-NEXT: Running analysis: DominatorTreeAnalysis on test1_f
 
 ; An external function used to control branches.

test/Transforms/LoopRotate/pr35210.ll

 ; CHECK-NEXT: Running pass: LCSSAPass on f
 ; CHECK-NEXT: Finished llvm::Function pass manager run.
 ; CHECK-NEXT: Running analysis: AAManager on f
 ; CHECK-NEXT: Running analysis: TargetLibraryAnalysis on f
 ; CHECK-NEXT: Running analysis: ScalarEvolutionAnalysis on f
 ; CHECK-NEXT: Running analysis: TargetIRAnalysis on f
 ; CHECK-NEXT: Running analysis: InnerAnalysisManagerProxy{{.*}} on f
 ; CHECK-NEXT: Starting Loop pass manager run.
+; CHECK-NEXT: Running analysis: PassInstrumentationAnalysis on bb
 ; CHECK-NEXT: Running pass: LoopRotatePass on Loop at depth 1 containing: %bb<header><exiting>,%bb4<latch>
 ; CHECK-NEXT: Folding loop latch bb4 into bb
 ; CHECK-NEXT: Invalidating all non-preserved analyses for: bb
 ; CHECK-NEXT: Finished Loop pass manager run.
 ; CHECK-NEXT: Invalidating all non-preserved analyses for: f
 ; CHECK-NEXT: Invalidating analysis: PostDominatorTreeAnalysis on f
 ; CHECK-NEXT: Running pass: ADCEPass on f
 ; CHECK-NEXT: Running analysis: PostDominatorTreeAnalysis on f

unittests/Analysis/CGSCCPassManagerTest.cpp

CGSCCPassManagerTest()
             "}\n"
             "define void @x() {\n"
             "entry:\n"
             "  ret void\n"
             "}\n")) {
     MAM.registerPass([&] { return TargetLibraryAnalysis(); });
     MAM.registerPass([&] { return LazyCallGraphAnalysis(); });
     MAM.registerPass([&] { return FunctionAnalysisManagerModuleProxy(FAM); });
+
+    // Register required pass instrumentation analysis.
+    MAM.registerPass([&] { return PassInstrumentationAnalysis(); });
+    CGAM.registerPass([&] { return PassInstrumentationAnalysis(); });
+    FAM.registerPass([&] { return PassInstrumentationAnalysis(); });
+
+    // Cross-register proxies.
     MAM.registerPass([&] { return CGSCCAnalysisManagerModuleProxy(CGAM); });
     CGAM.registerPass([&] { return FunctionAnalysisManagerCGSCCProxy(); });
     CGAM.registerPass([&] { return ModuleAnalysisManagerCGSCCProxy(MAM); });
     FAM.registerPass([&] { return CGSCCAnalysisManagerFunctionProxy(CGAM); });
     FAM.registerPass([&] { return ModuleAnalysisManagerFunctionProxy(MAM); });
   }
 };
 

unittests/IR/PassBuilderCallbacksTest.cpp

 //===- unittests/IR/PassBuilderCallbacksTest.cpp - PB Callback Tests --===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
+#include <functional>
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
+#include <llvm/ADT/Any.h>
 #include <llvm/Analysis/CGSCCPassManager.h>
 #include <llvm/Analysis/LoopAnalysisManager.h>
 #include <llvm/AsmParser/Parser.h>
 #include <llvm/IR/LLVMContext.h>
+#include <llvm/IR/PassInstrumentation.h>
 #include <llvm/IR/PassManager.h>
 #include <llvm/Passes/PassBuilder.h>
+#include <llvm/Support/Regex.h>
 #include <llvm/Support/SourceMgr.h>
 #include <llvm/Transforms/Scalar/LoopPassManager.h>
 
 using namespace llvm;
 
 namespace llvm {
 /// Provide an ostream operator for StringRef.
 ///
 /// For convenience we provide a custom matcher below for IRUnit's and analysis
 /// result's getName functions, which most of the time returns a StringRef. The
 /// matcher makes use of this operator.
 static std::ostream &operator<<(std::ostream &O, StringRef S) {
   return O << S.str();
 }
 }
 
 namespace {
+using testing::AnyNumber;
+using testing::AtLeast;
 using testing::DoDefault;
 using testing::Return;
 using testing::Expectation;
 using testing::Invoke;
 using testing::WithArgs;
 using testing::_;
 
 /// A CRTP base for analysis mock handles
Result run(IRUnitT &IR, AnalysisManagerT &AM, ExtraArgTs... ExtraArgs) {
       return Handle->run(IR, AM, ExtraArgs...);
     }
   };
 
   Analysis getAnalysis() { return Analysis(static_cast<DerivedT &>(*this)); }
   typename Analysis::Result getResult() {
     return typename Analysis::Result(static_cast<DerivedT &>(*this));
   }
+  static StringRef getName() { return llvm::getTypeName<DerivedT>(); }
 
 protected:
   // FIXME: MSVC seems unable to handle a lambda argument to Invoke from within
   // the template, so we use a boring static function.
   static bool invalidateCallback(IRUnitT &IR, const PreservedAnalyses &PA,
                                  typename AnalysisManagerT::Invalidator &Inv) {
     auto PAC = PA.template getChecker<Analysis>();
     return !PAC.preserved() &&
public:
 
   public:
     PreservedAnalyses run(IRUnitT &IR, AnalysisManagerT &AM,
                           ExtraArgTs... ExtraArgs) {
       return Handle->run(IR, AM, ExtraArgs...);
     }
   };
 
+  static StringRef getName() { return llvm::getTypeName<DerivedT>(); }
+
   Pass getPass() { return Pass(static_cast<DerivedT &>(*this)); }
 
 protected:
   /// Derived classes should call this in their constructor to set up default
   /// mock actions. (We can't do this in our constructor because this has to
   /// run after the DerivedT is constructed.)
   void setDefaults() {
     ON_CALL(static_cast<DerivedT &>(*this),
struct MockAnalysisHandle<Module>
   MOCK_METHOD2(run, Analysis::Result(Module &, ModuleAnalysisManager &));
 
   MOCK_METHOD3(invalidate, bool(Module &, const PreservedAnalyses &,
                                 ModuleAnalysisManager::Invalidator &));
 
   MockAnalysisHandle<Module>() { setDefaults(); }
 };
 
+struct MockPassInstrumentationCallbacks {
+  MockPassInstrumentationCallbacks() {
+    ON_CALL(*this, runBeforePass(_, _)).WillByDefault(Return(true));
+    // Generic EXPECT_CALLs are needed to match instrumentation on unimportant
+    // parts of a pipeline that we do not care about (e.g. various passes added
+    // by default by PassBuilder - Verifier pass etc).
+    EXPECT_CALL(*this, runBeforePass(_, _)).Times(AnyNumber());
+    EXPECT_CALL(*this, runAfterPass(_, _)).Times(AnyNumber());
+  }
+  MOCK_METHOD2(runBeforePass, bool(StringRef PassID, llvm::Any));
+  MOCK_METHOD2(runAfterPass, void(StringRef PassID, llvm::Any));
+};
+
 static std::unique_ptr<Module> parseIR(LLVMContext &C, const char *IR) {
   SMDiagnostic Err;
   return parseAssemblyString(IR, Err, C);
 }
 
+/// Helper for HasName matcher that returns getName both for IRUnit and
+/// for IRUnit pointer wrapper into llvm::Any (wrapped by PassInstrumentation).
+template <typename IRUnitT> StringRef getName(const IRUnitT &IR) {
+  return IR.getName();
+}
+
+template <> StringRef getName(const StringRef &name) { return name; }
+
+template <> StringRef getName(const llvm::Any &WrappedIR) {
+  if (any_isa<const Module *>(WrappedIR))
+    return any_cast<const Module *>(WrappedIR)->getName();
+  if (any_isa<const Function *>(WrappedIR))
+    return any_cast<const Function *>(WrappedIR)->getName();
+  if (any_isa<const Loop *>(WrappedIR))
+    return any_cast<const Loop *>(WrappedIR)->getName();
+  if (any_isa<const LazyCallGraph::SCC *>(WrappedIR))
+    return any_cast<const LazyCallGraph::SCC *>(WrappedIR)->getName();
+  return "<UNKNOWN>";
+}
+/// Define a custom matcher for objects which support a 'getName' method.
+///
+/// LLVM often has IR objects or analysis objects which expose a name
+/// and in tests it is convenient to match these by name for readability.
+/// Usually, this name is either a StringRef or a plain std::string. This
+/// matcher supports any type exposing a getName() method of this form whose
+/// return value is compatible with an std::ostream. For StringRef, this uses
+/// the shift operator defined above.
+///
+/// It should be used as:
+///
+///   HasName("my_function")
+///
+/// No namespace or other qualification is required.
+MATCHER_P(HasName, Name, "") {
+  *result_listener << "has name '" << getName(arg) << "'";
+  return Name == getName(arg);
+}
+
+MATCHER_P(HasNameRegex, Name, "") {
+  *result_listener << "has name '" << getName(arg) << "'";
+  llvm::Regex r(Name);
+  return r.match(getName(arg));
+}
+
 template <typename PassManagerT> class PassBuilderCallbacksTest;
 
 /// This test fixture is shared between all the actual tests below and
 /// takes care of setting up appropriate defaults.
 ///
 /// The template specialization serves to extract the IRUnit and AM types from
 /// the given PassManagerT.
 template <typename TestIRUnitT, typename... ExtraPassArgTs,
           typename... ExtraAnalysisArgTs>
 class PassBuilderCallbacksTest<PassManager<
     TestIRUnitT, AnalysisManager<TestIRUnitT, ExtraAnalysisArgTs...>,
     ExtraPassArgTs...>> : public testing::Test {
 protected:
   using IRUnitT = TestIRUnitT;
   using AnalysisManagerT = AnalysisManager<TestIRUnitT, ExtraAnalysisArgTs...>;
   using PassManagerT =
       PassManager<TestIRUnitT, AnalysisManagerT, ExtraPassArgTs...>;
   using AnalysisT = typename MockAnalysisHandle<IRUnitT>::Analysis;
 
   LLVMContext Context;
   std::unique_ptr<Module> M;
 
+  PassInstrumentationCallbacks PIC;
   PassBuilder PB;
   ModulePassManager PM;
   LoopAnalysisManager LAM;
   FunctionAnalysisManager FAM;
   CGSCCAnalysisManager CGAM;
   ModuleAnalysisManager AM;
 
   MockPassHandle<IRUnitT> PassHandle;
   MockAnalysisHandle<IRUnitT> AnalysisHandle;
+  MockPassInstrumentationCallbacks PICallbacks;
 
   static PreservedAnalyses getAnalysisResult(IRUnitT &U, AnalysisManagerT &AM,
                                              ExtraAnalysisArgTs &&... Args) {
     (void)AM.template getResult<AnalysisT>(
         U, std::forward<ExtraAnalysisArgTs>(Args)...);
     return PreservedAnalyses::all();
   }
 
   PassBuilderCallbacksTest()
       : M(parseIR(Context,
                   "declare void @bar()\n"
                   "define void @foo(i32 %n) {\n"
                   "entry:\n"
                   "  br label %loop\n"
                   "loop:\n"
                   "  %iv = phi i32 [ 0, %entry ], [ %iv.next, %loop ]\n"
                   "  %iv.next = add i32 %iv, 1\n"
                   "  tail call void @bar()\n"
                   "  %cmp = icmp eq i32 %iv, %n\n"
                   "  br i1 %cmp, label %exit, label %loop\n"
                   "exit:\n"
                   "  ret void\n"
                   "}\n")),
-        PM(true), LAM(true), FAM(true), CGAM(true), AM(true) {
+        PIC(), PB(nullptr, None, &PIC), PM(true), LAM(true), FAM(true),
+        CGAM(true), AM(true) {
 
     /// Register a callback for analysis registration.
     ///
     /// The callback is a function taking a reference to an AnalyisManager
     /// object. When called, the callee gets to register its own analyses with
     /// this PassBuilder instance.
     PB.registerAnalysisRegistrationCallback([this](AnalysisManagerT &AM) {
       // Register our mock analysis
PB.registerPipelineParsingCallback(
           /// Parse the name of our pass mock handle
           if (Name == "test-transform") {
             PM.addPass(PassHandle.getPass());
             return true;
           }
           return false;
         });
 
+    /// Register pass instrumentation
+    PB.registerPassInstrumentation([this](PassInstrumentationCallbacks &PIC) {
+      using namespace std::placeholders;
+      PIC.registerBeforePassCallback(
+          std::bind(&MockPassInstrumentationCallbacks::runBeforePass,
+                    &PICallbacks, _1, _2));
+      PIC.registerAfterPassCallback(
+          std::bind(&MockPassInstrumentationCallbacks::runAfterPass,
+                    &PICallbacks, _1, _2));
+    });
     /// Register builtin analyses and cross-register the analysis proxies
     PB.registerModuleAnalyses(AM);
     PB.registerCGSCCAnalyses(CGAM);
     PB.registerFunctionAnalyses(FAM);
     PB.registerLoopAnalyses(LAM);
     PB.crossRegisterProxies(LAM, FAM, CGAM, AM);
   }
 };
 
-/// Define a custom matcher for objects which support a 'getName' method.
-///
-/// LLVM often has IR objects or analysis objects which expose a name
-/// and in tests it is convenient to match these by name for readability.
-/// Usually, this name is either a StringRef or a plain std::string. This
-/// matcher supports any type exposing a getName() method of this form whose
-/// return value is compatible with an std::ostream. For StringRef, this uses
-/// the shift operator defined above.
-///
-/// It should be used as:
-///
-///   HasName("my_function")
-///
-/// No namespace or other qualification is required.
-MATCHER_P(HasName, Name, "") {
-  *result_listener << "has name '" << arg.getName() << "'";
-  return Name == arg.getName();
-}
-
 using ModuleCallbacksTest = PassBuilderCallbacksTest<ModulePassManager>;
 using CGSCCCallbacksTest = PassBuilderCallbacksTest<CGSCCPassManager>;
 using FunctionCallbacksTest = PassBuilderCallbacksTest<FunctionPassManager>;
 using LoopCallbacksTest = PassBuilderCallbacksTest<LoopPassManager>;
 
 /// Test parsing of the name of our mock pass for all IRUnits.
 ///
 /// The pass should by default run our mock analysis and then preserve it.
 TEST_F(ModuleCallbacksTest, Passes) {
   EXPECT_CALL(AnalysisHandle, run(HasName("<string>"), _));
   EXPECT_CALL(PassHandle, run(HasName("<string>"), _))
       .WillOnce(Invoke(getAnalysisResult));
 
   StringRef PipelineText = "test-transform";
   ASSERT_TRUE(PB.parsePassPipeline(PM, PipelineText, true))
       << "Pipeline was: " << PipelineText;
+
+  PM.run(*M, AM);
+}
+
+TEST_F(ModuleCallbacksTest, InstrumentedPasses) {
+  EXPECT_CALL(AnalysisHandle, run(HasName("<string>"), _));
+  EXPECT_CALL(PassHandle, run(HasName("<string>"), _))
+      .WillOnce(Invoke(getAnalysisResult));
+
+  {
+    testing::InSequence InstrumentationExpectationsSequenced;
+    EXPECT_CALL(PICallbacks, runBeforePass(HasNameRegex("MockPassHandle"),
+                                           HasName("<string>")));
+    EXPECT_CALL(PICallbacks, runAfterPass(HasNameRegex("MockPassHandle"),
+                                          HasName("<string>")));
+  }
+
+  StringRef PipelineText = "test-transform";
+  ASSERT_TRUE(PB.parsePassPipeline(PM, PipelineText, true))
+      << "Pipeline was: " << PipelineText;
+
+  PM.run(*M, AM);
+}
+
+TEST_F(ModuleCallbacksTest, InstrumentedSkippedPasses) {
+  // Skip the pass by returning false.
+  EXPECT_CALL(PICallbacks, runBeforePass(HasNameRegex("MockPassHandle"),
+                                         HasName("<string>")))
+      .WillOnce(Return(false));
+
+  EXPECT_CALL(AnalysisHandle, run(HasName("<string>"), _)).Times(0);
+  EXPECT_CALL(PassHandle, run(HasName("<string>"), _)).Times(0);
+
+  // As the pass is skipped there is no afterPass as well.
+  EXPECT_CALL(PICallbacks, runAfterPass(HasNameRegex("MockPassHandle"), _))
+      .Times(0);
+
+  StringRef PipelineText = "test-transform";
+  ASSERT_TRUE(PB.parsePassPipeline(PM, PipelineText, true))
+      << "Pipeline was: " << PipelineText;
+
   PM.run(*M, AM);
 }
 
 TEST_F(FunctionCallbacksTest, Passes) {
   EXPECT_CALL(AnalysisHandle, run(HasName("foo"), _));
   EXPECT_CALL(PassHandle, run(HasName("foo"), _))
       .WillOnce(Invoke(getAnalysisResult));
 
   StringRef PipelineText = "test-transform";
   ASSERT_TRUE(PB.parsePassPipeline(PM, PipelineText, true))
       << "Pipeline was: " << PipelineText;
   PM.run(*M, AM);
 }
 
+TEST_F(FunctionCallbacksTest, InstrumentedPasses) {
+  EXPECT_CALL(AnalysisHandle, run(HasName("foo"), _));
+  EXPECT_CALL(PassHandle, run(HasName("foo"), _))
+      .WillOnce(Invoke(getAnalysisResult));
+
+  {
+    testing::InSequence InstrumentationExpectationsSequenced;
+    EXPECT_CALL(PICallbacks,
+                runBeforePass(HasNameRegex("MockPassHandle"), HasName("foo")));
+    EXPECT_CALL(PICallbacks,
+                runAfterPass(HasNameRegex("MockPassHandle"), HasName("foo")));
+  }
+
+  StringRef PipelineText = "test-transform";
+  ASSERT_TRUE(PB.parsePassPipeline(PM, PipelineText, true))
+      << "Pipeline was: " << PipelineText;
+  PM.run(*M, AM);
+}
+
+TEST_F(FunctionCallbacksTest, InstrumentedSkippedPasses) {
+  // Skip the pass by returning false.
+  EXPECT_CALL(PICallbacks,
+              runBeforePass(HasNameRegex("MockPassHandle"), HasName("foo")))
+      .WillOnce(Return(false));
+
+  EXPECT_CALL(AnalysisHandle, run(HasName("foo"), _)).Times(0);
+  EXPECT_CALL(PassHandle, run(HasName("foo"), _)).Times(0);
+
+  // As the pass is skipped there is no afterPass as well.
+  EXPECT_CALL(PICallbacks, runAfterPass(HasNameRegex("MockPassHandle"), _))
+      .Times(0);
+
+  StringRef PipelineText = "test-transform";
+  ASSERT_TRUE(PB.parsePassPipeline(PM, PipelineText, true))
+      << "Pipeline was: " << PipelineText;
+  PM.run(*M, AM);
+}
+
 TEST_F(LoopCallbacksTest, Passes) {
   EXPECT_CALL(AnalysisHandle, run(HasName("loop"), _, _));
   EXPECT_CALL(PassHandle, run(HasName("loop"), _, _, _))
       .WillOnce(WithArgs<0, 1, 2>(Invoke(getAnalysisResult)));
 
   StringRef PipelineText = "test-transform";
   ASSERT_TRUE(PB.parsePassPipeline(PM, PipelineText, true))
       << "Pipeline was: " << PipelineText;
   PM.run(*M, AM);
 }
 
+TEST_F(LoopCallbacksTest, InstrumentedPasses) {
+  EXPECT_CALL(AnalysisHandle, run(HasName("loop"), _, _));
+  EXPECT_CALL(PassHandle, run(HasName("loop"), _, _, _))
+      .WillOnce(WithArgs<0, 1, 2>(Invoke(getAnalysisResult)));
+  {
+    testing::InSequence InstrumentationExpectationsSequenced;
+    EXPECT_CALL(PICallbacks,
+                runBeforePass(HasNameRegex("MockPassHandle"), HasName("loop")));
+    EXPECT_CALL(PICallbacks,
+                runAfterPass(HasNameRegex("MockPassHandle"), HasName("loop")));
+  }
+
+  StringRef PipelineText = "test-transform";
+  ASSERT_TRUE(PB.parsePassPipeline(PM, PipelineText, true))
+      << "Pipeline was: " << PipelineText;
+  PM.run(*M, AM);
+}
+
+TEST_F(LoopCallbacksTest, InstrumentedSkippedPasses) {
+  // Skip the pass by returning false.
+  EXPECT_CALL(PICallbacks,
+              runBeforePass(HasNameRegex("MockPassHandle"), HasName("loop")))
+      .WillOnce(Return(false));
+
+  EXPECT_CALL(AnalysisHandle, run(HasName("loop"), _, _)).Times(0);
+  EXPECT_CALL(PassHandle, run(HasName("loop"), _, _, _)).Times(0);
+
+  // As the pass is skipped there is no afterPass as well.
+  EXPECT_CALL(PICallbacks, runAfterPass(HasNameRegex("MockPassHandle"), _))
+      .Times(0);
+
+  StringRef PipelineText = "test-transform";
+  ASSERT_TRUE(PB.parsePassPipeline(PM, PipelineText, true))
+      << "Pipeline was: " << PipelineText;
+  PM.run(*M, AM);
+}
+
 TEST_F(CGSCCCallbacksTest, Passes) {
   EXPECT_CALL(AnalysisHandle, run(HasName("(foo)"), _, _));
   EXPECT_CALL(PassHandle, run(HasName("(foo)"), _, _, _))
       .WillOnce(WithArgs<0, 1, 2>(Invoke(getAnalysisResult)));
 
   StringRef PipelineText = "test-transform";
   ASSERT_TRUE(PB.parsePassPipeline(PM, PipelineText, true))
       << "Pipeline was: " << PipelineText;
   PM.run(*M, AM);
 }
 
+TEST_F(CGSCCCallbacksTest, InstrumentedPasses) {
+  EXPECT_CALL(AnalysisHandle, run(HasName("(foo)"), _, _));
+  EXPECT_CALL(PassHandle, run(HasName("(foo)"), _, _, _))
+      .WillOnce(WithArgs<0, 1, 2>(Invoke(getAnalysisResult)));
+
+  {
+    testing::InSequence InstrumentationExpectationsSequenced;
+    EXPECT_CALL(PICallbacks, runBeforePass(HasNameRegex("MockPassHandle"),
+                                           HasName("(foo)")));
+    EXPECT_CALL(PICallbacks,
+                runAfterPass(HasNameRegex("MockPassHandle"), HasName("(foo)")));
+  }
+
+  StringRef PipelineText = "test-transform";
+  ASSERT_TRUE(PB.parsePassPipeline(PM, PipelineText, true))
+      << "Pipeline was: " << PipelineText;
+  PM.run(*M, AM);
+}
+
+TEST_F(CGSCCCallbacksTest, InstrumentedSkippedPasses) {
+  // Skip the pass by returning false.
+  EXPECT_CALL(PICallbacks,
+              runBeforePass(HasNameRegex("MockPassHandle"), HasName("(foo)")))
+      .WillOnce(Return(false));
+
+  // neither Analysis nor Pass are called.
+  EXPECT_CALL(AnalysisHandle, run(HasName("(foo)"), _, _)).Times(0);
+  EXPECT_CALL(PassHandle, run(HasName("(foo)"), _, _, _)).Times(0);
+
+  // As the pass is skipped there is no afterPass as well.
+  EXPECT_CALL(PICallbacks, runAfterPass(HasNameRegex("MockPassHandle"), _))
+      .Times(0);
+
+  StringRef PipelineText = "test-transform";
+  ASSERT_TRUE(PB.parsePassPipeline(PM, PipelineText, true))
+      << "Pipeline was: " << PipelineText;
+  PM.run(*M, AM);
+}
+
 /// Test parsing of the names of analysis utilities for our mock analysis
 /// for all IRUnits.
 ///
 /// We first require<>, then invalidate<> it, expecting the analysis to be run
 /// once and subsequently invalidated.
 TEST_F(ModuleCallbacksTest, AnalysisUtilities) {
   EXPECT_CALL(AnalysisHandle, run(HasName("<string>"), _));
   EXPECT_CALL(AnalysisHandle, invalidate(HasName("<string>"), _, _));

unittests/IR/PassManagerTest.cpp

TEST_F(PassManagerTest, Basic) {
   FAM.registerPass([&] { return TestFunctionAnalysis(FunctionAnalysisRuns); });
 
   ModuleAnalysisManager MAM(/*DebugLogging*/ true);
   int ModuleAnalysisRuns = 0;
   MAM.registerPass([&] { return TestModuleAnalysis(ModuleAnalysisRuns); });
   MAM.registerPass([&] { return FunctionAnalysisManagerModuleProxy(FAM); });
   FAM.registerPass([&] { return ModuleAnalysisManagerFunctionProxy(MAM); });
 
+  MAM.registerPass([&] { return PassInstrumentationAnalysis(); });
+  FAM.registerPass([&] { return PassInstrumentationAnalysis(); });
+
   ModulePassManager MPM;
 
   // Count the runs over a Function.
   int FunctionPassRunCount1 = 0;
   int AnalyzedInstrCount1 = 0;
   int AnalyzedFunctionCount1 = 0;
   {
     // Pointless scoped copy to test move assignment.
PreservedAnalyses run(Function &F, CustomizedAnalysisManager &AM, int I,
     Callback(AM.getResult<CustomizedAnalysis>(F, I), O);
     return PreservedAnalyses::none();
   }
 };
 
 TEST_F(PassManagerTest, CustomizedPassManagerArgs) {
   CustomizedAnalysisManager AM;
   AM.registerPass([&] { return CustomizedAnalysis(); });
+  PassInstrumentationCallbacks PIC;
+  AM.registerPass([&] { return PassInstrumentationAnalysis(&PIC); });
 
   CustomizedPassManager PM;
 
   // Add an instance of the customized pass that just accumulates the input
   // after it is round-tripped through the analysis.
   int Result = 0;
   PM.addPass(
       CustomizedPass([](CustomizedAnalysis::Result &R, int &O) { O += R.I; }));
FAM.registerPass([&] {
     return TestDoublyIndirectFunctionAnalysis(DoublyIndirectAnalysisRuns);
   });
 
   ModuleAnalysisManager MAM(/*DebugLogging*/ true);
   MAM.registerPass([&] { return TestModuleAnalysis(ModuleAnalysisRuns); });
   MAM.registerPass([&] { return FunctionAnalysisManagerModuleProxy(FAM); });
   FAM.registerPass([&] { return ModuleAnalysisManagerFunctionProxy(MAM); });
 
+  PassInstrumentationCallbacks PIC;
+  MAM.registerPass([&] { return PassInstrumentationAnalysis(&PIC); });
+  FAM.registerPass([&] { return PassInstrumentationAnalysis(&PIC); });
+
   int InstrCount = 0, FunctionCount = 0;
   ModulePassManager MPM(/*DebugLogging*/ true);
   FunctionPassManager FPM(/*DebugLogging*/ true);
   // First just use the analysis to get the instruction count, and preserve
   // everything.
   FPM.addPass(LambdaPass([&](Function &F, FunctionAnalysisManager &AM) {
     auto &DoublyIndirectResult =
         AM.getResult<TestDoublyIndirectFunctionAnalysis>(F);

unittests/Transforms/Scalar/LoopPassManagerTest.cpp

LoopPassManagerTest()
     // We also allow loop passes to assume a set of other analyses and so need
     // those.
     FAM.registerPass([&] { return AAManager(); });
     FAM.registerPass([&] { return AssumptionAnalysis(); });
     FAM.registerPass([&] { return ScalarEvolutionAnalysis(); });
     FAM.registerPass([&] { return TargetLibraryAnalysis(); });
     FAM.registerPass([&] { return TargetIRAnalysis(); });
 
+    // Register required pass instrumentation analysis.
+    LAM.registerPass([&] { return PassInstrumentationAnalysis(); });
+    FAM.registerPass([&] { return PassInstrumentationAnalysis(); });
+    MAM.registerPass([&] { return PassInstrumentationAnalysis(); });
+
     // Cross-register proxies.
     LAM.registerPass([&] { return FunctionAnalysisManagerLoopProxy(FAM); });
     FAM.registerPass([&] { return LoopAnalysisManagerFunctionProxy(LAM); });
     FAM.registerPass([&] { return ModuleAnalysisManagerFunctionProxy(MAM); });
     MAM.registerPass([&] { return FunctionAnalysisManagerModuleProxy(FAM); });
   }
 };