Each one of these uses grabs the principal off of an object for pushing, but also enters the compartment of that object. So we shouldn't need this anymore.
Can I get a 'hell yeah'?
It would be nice to check these principals against the principals acquired
using the old mechanism. Unfortunately, they often differ. Because CAPS uses
JS stack frames, any time we enter a compartment and do an operation (even
throwing an Access-Denied exception) without running any JS code, we'll end
up with a different principal.
Our security story is pretty darn tied to compartments at this point, so let's
just pull the trigger.
In the new setup, all per-interface DOM binding files are exported into
mozilla/dom. General files not specific to an interface are also exported into
mozilla/dom.
In terms of namespaces, most things now live in mozilla::dom. Each interface
Foo that has generated code has a mozilla::dom::FooBinding namespace for said
generated code (and possibly a mozilla::bindings::FooBinding_workers if there's
separate codegen for workers).
IDL enums are a bit weird: since the name of the enum and the names of its
entries all end up in the same namespace, we still generate a C++ namespace
with the name of the IDL enum type with "Values" appended to it, with a
::valuelist inside for the actual C++ enum. We then typedef
EnumFooValues::valuelist to EnumFoo. That makes it a bit more difficult to
refer to the values, but means that values from different enums don't collide
with each other.
The enums with the proto and constructor IDs in them now live under the
mozilla::dom::prototypes and mozilla::dom::constructors namespaces respectively.
Again, this lets us deal sanely with the whole "enum value names are flattened
into the namespace the enum is in" deal.
The main benefit of this setup (and the reason "Binding" got appended to the
per-interface namespaces) is that this way "using mozilla::dom" should Just
Work for consumers and still allow C++ code to sanely use the IDL interface
names for concrete classes, which is fairly desirable.
--HG--
rename : dom/bindings/Utils.cpp => dom/bindings/BindingUtils.cpp
rename : dom/bindings/Utils.h => dom/bindings/BindingUtils.h
Currently to serialize principals stored in JSScript we have a rather complex
schema. First there is the transcode callback that the embedding must provide
to transcode principals using XDR API. Second we use rather complex glue code
to implement that callback in terms of writing/reading nsIObjectOutputStream/
nsIObjectInputStream. This glue code is duplicated in 3 places. All this can
be avoided if we simply delegate transcoding of principals to the caller. In
addition, at least in the case of the cached startup scripts we do not even
need to transcode the principals as the the cached scripts always have the
system principal so we can skip all the transcode complexity there.
The patch implemnts this idea. In particular, the code in JS engine
responsible for transcoding of principals is replaced by the single API
function JS_XDRSetPrincipals that the embedding can use to set principals for
decoded scripts and functions. Then the startup cache uses this to set the
principals for the decoded script to the system principals. The other two
places in nsJSContext::Serialize and XBL_SerializeFunction that need to
serialize principals together with a function or script now uses common
utilities in nsXPConnect so the serialization complexity resides in the single
place.
In just 2 cases where JSPrincipals::codebase is used it can be reconstructed from the values stored in the associated nsJSPrincipal. In addition the patch makes nsJSprincipals to inherit both from nsIPrincipal and JSPrincipals allowing to use static_cast to convert between nsIPrincipal and JSPrincipals pointers and to drop many cases of manual JSPrincipal reference counting.
