1394556 - Compile JSM/component scripts in strict mode by default

Status: RESOLVED FIXED

(Core :: XPConnect, enhancement)

Description

[Kris Maglione [:kmag]]

Bug 1186409 is currently blocked on non-strict `this` boxing issues in some JSMs. At this point, we shouldn't be relying on non-strict-mode behavior, so it's probably time to just enforce strict mode on all JSM/component scripts.

Comment 1

[Kris Maglione [:kmag]]

Attachment: Bug 1394556: Part 1 - Fix strict mode errors in JSM scripts.

Review commit: https://reviewboard.mozilla.org/r/173402/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/173402/

Comment 2

[Kris Maglione [:kmag]]

Attachment: Bug 1394556: Part 2 - Compile all JSM/module scripts in strict mode.

Review commit: https://reviewboard.mozilla.org/r/173404/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/173404/

Comment 3

[Kris Maglione [:kmag]]

Comment on attachment 8901988 [details]
Bug 1394556: Part 1 - Fix strict mode errors in JSM scripts.

https://reviewboard.mozilla.org/r/173402/#review178782

::: services/common/kinto-offline-client.js:21
(Diff revision 1)
>  
>  /*
>   * This file is generated from kinto.js - do not modify directly.
>   */
>  
> +const global = this;

This also needs to be fixed upstream. I'll file a separate PR for that.

Comment 4

[Kris Maglione [:kmag]]

Comment on attachment 8901988 [details]
Bug 1394556: Part 1 - Fix strict mode errors in JSM scripts.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/173402/diff/1-2/

Comment 5

[Kris Maglione [:kmag]]

Comment on attachment 8901989 [details]
Bug 1394556: Part 2 - Compile all JSM/module scripts in strict mode.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/173404/diff/1-2/

Comment 6

[Dave Townsend [:mossop]]

Comment on attachment 8901988 [details]
Bug 1394556: Part 1 - Fix strict mode errors in JSM scripts.

https://reviewboard.mozilla.org/r/173402/#review179246

::: testing/specialpowers/content/SpecialPowersObserver.jsm:258
(Diff revision 2)
>        }
>        let createdFiles = this._createdFiles;
>        try {
>          let promises = [];
>          aMessage.data.forEach(function(request) {
> -          const filePerms = 0666; // eslint-disable-line no-octal
> +          const filePerms = 0o666; // eslint-disable-line no-octal

I think you can get rid of the eslint disable here now.

Comment 7

[Dave Townsend [:mossop]]

Comment on attachment 8901989 [details]
Bug 1394556: Part 2 - Compile all JSM/module scripts in strict mode.

https://reviewboard.mozilla.org/r/173404/#review179252

Comment 8

[Kris Maglione [:kmag]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/3a804c720f13b46ba5604fd59904538b44546d23
Bug 1394556: Part 1 - Fix strict mode errors in JSM scripts. r=Mossop

https://hg.mozilla.org/integration/mozilla-inbound/rev/0ab0630eec0c15b591b379454fe59344bac62290
Bug 1394556: Part 2 - Compile all JSM/module scripts in strict mode. r=Mossop

Comment 9

[Kris Maglione [:kmag]]

Jörg, there's a good chance this will affect Thunderbird. Look out for errors like "TypeError: this is null", "TypeError: setting a property that has only a getter", and "ReferenceError: assignment to undeclared variable"

Comment 10

[Jorg K (CEST = GMT+2)]

Thanks for the heads-up, I love changes to JS (not) ;-(

Comment 11

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/3a804c720f13
https://hg.mozilla.org/mozilla-central/rev/0ab0630eec0c

Comment 12

[Ted Campbell [:tcampbell]]

(For further reference)
It is also possible to enforce strict-mode on the JSContext. We currently didn't do that. One way non-strict may sneak in is horrible stuff through Function(). The shared JSM global work still work in presence of non-strict code, but we should really avoid it to avoid potential problems.