1335571 - Use template craziness to allow covering more cases with compartment asserts

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Steve Fink [:sfink] [:s:]]

If we extend the compartment asserts a little more, we can handle things like a properties vector, which is of type MutableHandle<IdVector> aka MutableHandle<GCVector<jsid>>.

Comment 1

[Steve Fink [:sfink] [:s:]]

Attachment: Use template craziness to allow covering more cases with compartment asserts

The template is a little wonky, since I should probably also be testing whether operator++ exists, but I figure handling begin() and end() is enough of a signal that you intend to support C++ style iteration. Checking whether begin() and end() return the same type is kind of irrelevant; the point is really that they exist.

Comment 3

[Jeff Walden [:Waldo]]

Comment on attachment 8832251 [details] [diff] [review]
Use template craziness to allow covering more cases with compartment asserts

Review of attachment 8832251 [details] [diff] [review]:
-----------------------------------------------------------------

What you "should" use is concepts, but...well...not quite yet.  :-\  Can't wait til a proposal's far enough along that we can start adding macro-ized concepts usage, then for at least one compiler to support it so you can use that one compiler to get that substantial benefit.

::: js/src/jscntxtinlines.h
@@ +108,5 @@
> +        mozilla::IsSame<
> +            decltype(((Container*)nullptr)->begin()),
> +            decltype(((Container*)nullptr)->end())
> +        >::value,
> +        void

void is the default, so you can omit the extra parameter.

@@ +110,5 @@
> +            decltype(((Container*)nullptr)->end())
> +        >::value,
> +        void
> +    >::Type
> +    check(Container& container) {

I think you can make |Container| const.

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/ad428bc273fe
Use template craziness to allow covering more cases with compartment asserts, r=Waldo

Comment 5

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/ad428bc273fe