1472130 - Enable same-compartment-realms in the JS shell with --fuzzing-safe

Status: RESOLVED FIXED

(Core :: JavaScript Engine, enhancement)

Description

[Jan de Mooij [:jandem]]

newGlobal's sameCompartmentAs option is a no-op if --fuzzing-safe is used, this was done to avoid breaking the world:

https://searchfox.org/mozilla-central/rev/d2966246905102b36ef5221b0e3cbccf7ea15a86/js/src/shell/js.cpp#5270

There's still a lot more work to do, but I think once bug 1466133 is fixed things should be in a fuzzable state (famous last words).

Comment 1

[Jan de Mooij [:jandem]]

Attachment: Part 1 - Fix a bogus assert in GetInitialShapeProtoKey with same-compartment realms

This fixes one obvious issue with cross-realm protos.

This + bug 1463163 are the only failures I get when I change the test262 harness in the JS shell to use same-compartment realms for $262.createRealm(). Bug 1463163 is a correctness issue though and doesn't block fuzzing.

Comment 2

[Jan de Mooij [:jandem]]

The Array test actually fails with --ion-eager --no-threads but that's a pre-existing and unrelated issue, filed bug 1472132. I'll change the test to use a different constructor that's unaffected.

Comment 3

[Jan de Mooij [:jandem]]

Attachment: Part 2 - Allow creating same-compartment realms in the shell with --fuzzing-safe

Worst case this breaks the world and we can just back out this one-liner.

Comment 4

[Luke Wagner [:luke]]

Comment on attachment 8988696 [details] [diff] [review]
Part 2 - Allow creating same-compartment realms in the shell with --fuzzing-safe

Review of attachment 8988696 [details] [diff] [review]:
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\o/

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/da03ca62424b
part 1 - Fix a bogus assert in GetInitialShapeProtoKey with same-compartment realms. r=luke
https://hg.mozilla.org/integration/mozilla-inbound/rev/d473e8b25db6
part 2 - Allow creating same-compartment realms in the shell with --fuzzing-safe. r=luke

Comment 6

[Arthur Iakab [arthur_iakab]]

https://hg.mozilla.org/mozilla-central/rev/da03ca62424b
https://hg.mozilla.org/mozilla-central/rev/d473e8b25db6