1828144 - Implement the WeakMap/WeakSet changes from the Symbols as WeakMap keys proposal

Status: RESOLVED FIXED

(Core :: JavaScript Engine, enhancement, P3)

Comment 1

[Jonatan Klemets [:jon4t4n]]

Attachment: Bug 1828144 - Part 2: Change ObjectValueWeakMap to ValueValueWeakMap

To be able to use an object or a symbol as the weak map key, we need to change
the underlying type from JSObject* to Value.

Comment 2

[Jonatan Klemets [:jon4t4n]]

Attachment: Bug 1828144 - Part 3: Implement symbols as weakmap keys proposal

Depends on D175672

Comment 3

[Jonatan Klemets [:jon4t4n]]

Attachment: WIP: Bug 1828144 - Part 3: Update test262-update.py to enable symbols as weakmap keys tests

Depends on D176691

Comment 4

[Jonatan Klemets [:jon4t4n]]

Attachment: WIP: Bug 1828144 - Part 4: Run test262-update.py --revision $(head -n 1 test262/GIT-INFO | awk '{print $2}')

Depends on D176692

Comment 5

[Jonatan Klemets [:jon4t4n]]

I don't currently have the time to complete this implementation, and I don't want to be the blocker on a stage 4 proposal. Thus, feel free to take my patches as a starting point!

Part 1 should compile and pass all existing tests. Part 2 is still very WIP.

(Let me know if I should abandon the patches instead of leaving them as planned changes.)

Comment 6

[Yoshi Cheng-Hao Huang [:allstars.chh][:allstarschh][:yoshi] | PTO]

Attachment: Bug 1828144 - Part 1: add pref symbols-as-weakmap-keys.

Comment 7

[Yoshi Cheng-Hao Huang [:allstars.chh][:allstarschh][:yoshi] | PTO]

Attachment: Bug 1828144 - Part 5: test262-update for symbols-as-weakmap-keys.

Comment 8

[Yoshi Cheng-Hao Huang [:allstars.chh][:allstarschh][:yoshi] | PTO]

Originally I reuse the patches from jon4t4n, but I cannot change the state of the patches because I am not the author.
I'll create a new patch stack for these.

Comment 9

[Yoshi Cheng-Hao Huang [:allstars.chh][:allstarschh][:yoshi] | PTO]

Attachment: Bug 1828144 - Part 2: Add ValueValueWeakMap and use it in WeakMapObject and WeakSetObject.

Add a WeakMap whose key is of type JS::Value, so we can store an object or a
symbol as the weak map key.

Comment 10

[Yoshi Cheng-Hao Huang [:allstars.chh][:allstarschh][:yoshi] | PTO]

Attachment: Bug 1828144 - Part 4: Allow using symbols as WeakMap/WeakSet keys.

Comment 11

[Jonatan Klemets [:jon4t4n]]

Thanks for picking this up.
(I abandoned my patches to make the bug look less messy.)

Comment 12

[Yoshi Cheng-Hao Huang [:allstars.chh][:allstarschh][:yoshi] | PTO]

Attachment: Bug 1828144 - Part 3: Implement CanBeHeldWeakly.

Comment 13

[Yoshi Cheng-Hao Huang [:allstars.chh][:allstarschh][:yoshi] | PTO]

As Jonco suggested, the use case for Symbols as WeakRef/FinalizationRegistry targets are Shadow-Realms, and Record-Tuples, which are demoted stage 2, so in this bug I will only implement the WeakMap/WeakSet changes

Comment 14

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/453a7000485e
Part 1: add pref symbols-as-weakmap-keys. r=jonco,sfink
https://hg.mozilla.org/integration/autoland/rev/6bebd6afcc29
Part 2: Add ValueValueWeakMap and use it in WeakMapObject and WeakSetObject. r=jonco,sfink
https://hg.mozilla.org/integration/autoland/rev/197dca60966e
Part 3: Implement CanBeHeldWeakly. r=jonco,sfink
https://hg.mozilla.org/integration/autoland/rev/da0e12436a83
Part 4: Allow using symbols as WeakMap/WeakSet keys. r=jonco,sfink
https://hg.mozilla.org/integration/autoland/rev/c6ceb6c0817b
Part 5: test262-update for symbols-as-weakmap-keys. r=jonco,sfink
https://hg.mozilla.org/integration/autoland/rev/782ceca184bc
apply code formatting via Lando

Comment 15

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/453a7000485e
https://hg.mozilla.org/mozilla-central/rev/6bebd6afcc29
https://hg.mozilla.org/mozilla-central/rev/197dca60966e
https://hg.mozilla.org/mozilla-central/rev/da0e12436a83
https://hg.mozilla.org/mozilla-central/rev/c6ceb6c0817b
https://hg.mozilla.org/mozilla-central/rev/782ceca184bc