1252498 - Baldr: add Wasm object behind pref, default off

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Luke Wagner [:luke]]

This patch adds javascript.options.wasm, defaulting to false on all platforms.  When enabled, this pref adds a 'Wasm' global property (similar to Math, JSON and SIMD).  The Wasm object currently has one static method named instantiateModule which is just a renaming of the previous wasmEval TestingFunction.  We already know we're going to replace Wasm.instantiateModule with an async method + sync constructor, but its inclusion now allows interop with the v8 experimental impl and running the same demos on both (once the binary formats converge).

Comment 1

[Luke Wagner [:luke]]

Attachment: wasm-obj-with-pref

Confirmed is not present by default in browser build.

Comment 2

[Jason Orendorff [:jorendorff]]

Comment on attachment 8725296 [details] [diff] [review]
wasm-obj-with-pref

Review of attachment 8725296 [details] [diff] [review]:
-----------------------------------------------------------------

r=me.

::: js/src/asmjs/Wasm.cpp
@@ +1381,5 @@
> +{
> +    MOZ_ASSERT(cx->runtime()->options().wasm());
> +
> +    CallArgs args = CallArgsFromVp(argc, vp);
> +    RootedObject callee(cx, &args.callee());

This variable is unused.

::: js/src/asmjs/Wasm.h
@@ +35,5 @@
>  HasCompilerSupport(ExclusiveContext* cx);
>  
> +// Return whether WebAssembly can be used at all on this platform.
> +bool
> +IsSupported(JSContext* cx);

I don't see a definition or use of this in this patch. (And the comment leaves me wondering what the difference is between this and HasCompilerSupport(), but I guess that is probably moot.)

Comment 3

[Luke Wagner [:luke]]

(In reply to Jason Orendorff [:jorendorff] from comment #2)
> I don't see a definition or use of this in this patch.

Oops, that's leftover from an intermediate state of the patch; it can be deleted.

Comment 4

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/6c8b2fbba88b

Comment 5

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/6c8b2fbba88b