1542064 - Add MOZ_DBG support for RawServoAnimationValue (or AnimationValue)

Status: RESOLVED FIXED

(Core :: DOM: Animation, enhancement, P5)

Description

[Boris Chiou [:boris]]

In C++, it's pretty hard to dump the servo animation value for now. We may use cbindgen to generate RawServoAnimationValue in the future, but it's still worth to add an operator<< for AnimationValue, so it'd be easier to dump the animation value on the gecko side.

Comment 1

[Brian Birtles (:birtles)]

If we do that, we could probably drop DumpAnimationProperties too (which I made some tweaks to here: https://github.com/birtles/gecko-dev/commit/c8d47602c819bb1512ddeb6d8cd515258ae93095)

At some point I also found myself wanting to dump the specified versions too like we get in Keyframe/PropertyValuePair objects: https://github.com/birtles/gecko-dev/commit/6a061e690b4539cf6a8c35199fb12e0b00a33828

Comment 2

[Boris Chiou [:boris]]

I would like to debug animations for OMTA, so maybe it's time to implement this.

Comment 3

[Brian Birtles (:birtles)]

I also recall wanting this recently and at that point I thought it would more convenient if we added support for RawServoAnimationValue rather than requiring the AnimationValue wrapper. (And I think somewhere I commented about a possible place to add support for RawServoAnimationValue but I don't recall where that was.)

Comment 4

[Boris Chiou [:boris]]

(In reply to Brian Birtles (:birtles) from comment #3)

I also recall wanting this recently and at that point I thought it would more convenient if we added support for RawServoAnimationValue rather than requiring the AnimationValue wrapper. (And I think somewhere I commented about a possible place to add support for RawServoAnimationValue but I don't recall where that was.)

I'd like to add two inline overloading functions in StyleAnimationValue.h:

inline std::ostream& operator<<(std::ostream& aOut, const AnimationValue& aValue); // This calls FFI to get the content of RawServoAnimationValue
inline std::ostream& operator<<(std::ostream& aOut, const RefPtr<RawServoAnimationValue>& aValue); // This calls FFI, too.

The first overloading function, for AnimationValue, works as I expected.

However, got a problem for the 2nd function. We have a function template for RefPtr<T> in RefPtr.h already [1]:

template <class T>
std::ostream& operator<<(std::ostream& aOut, const RefPtr<T>& aObj) {
  return mozilla::DebugValue(aOut, aObj.get());
}

It seems if I call

RefPtr<RawServoAnimationValue> value; // set from FFI.
MOZ_DBG(value);

This always outputs something like this: [MozDbg] ... value = 0x7f90cc70a188. Obviously, it uses the default behavior for non-derefed pointer. Ok, so I am struggling against this issue, and no idea how to make the non-template overloading operator work (in a different header file). Cameron, do you have any, hmm, possible way to overload the default behavior? I am a template idiot, so have no idea right now.

[1] https://searchfox.org/mozilla-central/rev/7556a400affa9eb99e522d2d17c40689fa23a729/mfbt/RefPtr.h#527-532

Comment 5

[Boris Chiou [:boris]]

Attachment: Bug 1542064 - Add MOZ_DBG support for AnimationValue.

Comment 6

[Boris Chiou [:boris]]

Still don't know why I cannot overloading the operator<<(..., const RefPtr<StyleAnimationValue>& ...) in StyleAnimationValue.h, so I only support MOZ_DBG for AnimationValue for now.

Comment 7

[Boris Chiou [:boris]]

Attachment: Bug 1542064 - Add MOZ_DBG support for AnimationValue.

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/e84f1dd07f66
Add MOZ_DBG support for AnimationValue. r=heycam

Comment 9

[Andrei Ciure[:aciure]]

https://hg.mozilla.org/mozilla-central/rev/e84f1dd07f66