1546817 - [jsdbg2] CrossCompartmentKey support for Debugger is over-complicated

Status: RESOLVED FIXED

(Core :: JavaScript Engine, task, P1)

Description

[Jim Blandy :jimb]

Adding new references from Debugger-related objects to debuggee objects is more complicated than it should be for a number of reasons, but one is that CrossCompartmentKey's structure is needlessly complex. Now that CrossCompartmentKey::wrapper is a mozilla::Variant, the different sorts of <Debugger, referent> keys can simply be different branches of that Variant, and there should be no need for the DebuggerAndObject 'kind' field.

Comment 1

[Jim Blandy :jimb]

Attachment: Bug 1546817: Refactor and document Debugger support in js::CrossCompartmentKey. r?sfink

This replaces the various Debugger-related member classes in
js::CrossCompartmentKey with a series of small structs that can be used directly
as alternatives in CrossCompartmentKey::WrappedType. Thus, instead of having a
two-level tag --- the Variant tag, and then for DebuggerAndObject case, a
DebuggerObjectKind value --- the Variant tag can do all the work by itself.

This also tightens up the types a bit: choosing the wrong DebuggerObjectKind
would be a silent error, but using the wrong constructor might get you a type
error (although unfortunately some of the types are not as specific as you might
hope: NativeObject instead of WasmInstanceObject, for example).

A new comment explains the rationale for giving Debugger API objects entries in
the wrapper map.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/b97c44f9234f
Refactor and document Debugger support in js::CrossCompartmentKey. r=sfink

Comment 3

[Narcis Beleuzu [:NarcisB]]

https://hg.mozilla.org/mozilla-central/rev/b97c44f9234f