1709956 - Evaluating an expression with a private method access while paused in a class method throws

Status: VERIFIED FIXED

(Core :: JavaScript Engine, defect, P3)

Description

[Matthew Gaudet (he/him) [:mgaudet]]

+++ This bug was initially created as a clone of Bug #1709542 +++

Steps to reproduce

1. Go to https://firefox-devtools-private-fields.glitch.me/
2. Open the console
3. In the page, click on the Create instance and pause button, this should pause
4. In the console, evaluate this.#getSalt()

Expected results

A result is displayed in the console

Actual results

The evaluation throws with:

Uncaught Error: private method calls aren't available in this context

Comment 1

[Matthew Gaudet (he/him) [:mgaudet]]

Attachment: Bug 1709956 - Support invoking private methods in Debugger.frame.eval r?arai

Comment 2

[Matthew Gaudet (he/him) [:mgaudet]]

The attached patch is incomplete, and will need more work before we can finish this up.

Comment 3

[Matthew Gaudet (he/him) [:mgaudet]]

The attached patch works for Private Methods, in at least one context. However, it's still enormously incomplete, and I don't think I plan on tackling this in the short-term

Comment 4

[Matthew Gaudet (he/him) [:mgaudet]]

Attachment: Bug 1709956 - Close over all private methods, not just instance methods r?arai

This ensures that we have access to static methods in Debugger.frame.evalInFrame;
If we don't close over, then the debugger seems to return undefined when trying
to load the private binding off of the class, which then causes CheckPrivateField
to assert.

Comment 5

[Matthew Gaudet (he/him) [:mgaudet]]

Attachment: Bug 1709956 - Add privateBrandSlot helper r?arai

Depends on D116178

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/0f2f7d2c7612
Close over all private methods, not just instance methods r=arai
https://hg.mozilla.org/integration/autoland/rev/2074ae57ca34
Add privateBrandSlot helper r=arai
https://hg.mozilla.org/integration/autoland/rev/ea02687ba7fe
Support invoking private methods in Debugger.frame.eval r=arai

Comment 8

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/0f2f7d2c7612
https://hg.mozilla.org/mozilla-central/rev/2074ae57ca34
https://hg.mozilla.org/mozilla-central/rev/ea02687ba7fe

Comment 9

[Giorgia Nichita, Release Desktop QA]

I have reproduced the issue using an affected Nightly build 90.0a1 (20210506092558) on Windows 10x64.
Verified fixed with Firefox 91.0b8 (20210727185725) on Windows 10x64, macOS 10.15 and Ubuntu 20.04.