Marked this as blocking #1519.

Additional to the above, exception types need to be marked.
The issue is how do we know from the Dart source for the dart:dom or dart:html library which exceptions are raised?

Exaample: Swarm contains this code because IDBDatabaseException is marked as used by the blanket 'mark all native types rule'.
The code could be eliminated if we knew the

// ********** Code for _IDBDatabaseExceptionJs **************
$dynamic("get$name").IDBDatabaseException = function() { return this.name; };

There are ~35 IDL operations that are marked in the IDL as raising this exception, but this information is not currently carried to the Dart code.

We could use the 'dummy code' feature to generate a reference.

class _IDBRequestJs implements IDBRequest {

   IDBAny get result() native 'return this.result' { throw new _IDBDatabaseExceptionJs(); }
}

_IDBDatabaseExceptionJs might not have a constructor.
We would probably need to generate a named generative constructor.

Additional to the above, there is one callback with an imprecise argument type.

module storage {
    interface [
        Conditional=SQL_DATABASE,
        Callback
    ] DatabaseCallback {
        boolean handleEvent(in Database database);
        boolean handleEvent(in DatabaseSync database);
    };
}

-->
typedef bool DatabaseCallback(var database);

This could be made precise by making Database and DatabaseSync extend a common marker interface.
WebSQL is probably in decline so we could simply accept imprecise analysis for this case.

Removed Area-Frog label.
Added Area-Dart2JS, FromAreaFrog labels.
Marked this as blocking #1519.
Unmarked this as blocking #-1519.

Is this a DOM issue?

Removed Area-Dart2JS, FromAreaFrog labels.
Added Area-DOM label.
Changed the title to: "used-type inference for hidden native classes".

This is a dart2js issue - the compiler emits code for native classes that cannot exist in the given program. There is sufficient information in the library to eliminate many of these.

I prototyped an analysis in Frog. The results are listed in a document called

"Investigation: Frog used-type analysis for native classes"

Removed Area-DOM label.
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Added this to the Later milestone.

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Marked this as blocking #1519.
Unmarked this as blocking #1519.

Added this to the M2 milestone.

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Kasper: Why did you move the priority to Low? This is a key piece to reducing the size cost of dart:html.

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Nicolas, Stephen, are you guys looking at this?

cc @rakudrama.

This comment was originally written by ngeoffray@google.com

Yes, Stephen is working on this, and we're looking at the interaction with dart2js's enqueuer.

Set owner to @rakudrama.

First part of this has been implemented in r14977.
It can be used via the command line flag --enable-native-live-type-analysis.
This is a resolution based liveness analysis.

The libraries now need to be correctly annotated before this can be the default.

After that, codegen based analysis should be implemented to improve on the resolution based results.

Libraries have been mostly annotated r15569 r15705

Feature enabled by default r15660

I'm moving this issue to M3 for the codegen based analysis.

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Added Type-Enhancement, Priority-Medium labels.
Changed the title to: "used-type inference for hidden native classes during codegen".

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Changed the title to: "dart2js: used-type inference for hidden native classes during codegen".

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@rakudrama - seems like this is now been done for quite some time? I'm closing the issue assuming so, but please reopen if not.