Allow invocation of constructors using Dart_Invoke.

Add a new method Dart_InvokeConstructor to allow invocation of generative
constructors on an object that has already been allocated using Dart_Allocate.

R=regis@google.com

Committed: https://code.google.com/p/dart/source/detail?r=28276

[regis, 2013-10-04 00:03:08]

LGTM

But I am a bit surprised that you have to allocate first. This won't work for
factories. Is the API documented somewhere?

https://chromiumcodereview.appspot.com/25675009/diff/1/runtime/vm/dart_api_im...
File runtime/vm/dart_api_impl.cc (right):

https://chromiumcodereview.appspot.com/25675009/diff/1/runtime/vm/dart_api_im...
runtime/vm/dart_api_impl.cc:3035: const Class& cls = Class::Handle(isolate,
Type::Cast(obj).type_class());
So, target is a type and we use its type class to resolve the function name, but
we ignore its type arguments (which only make sense if we call a constructor or
a factory). Should we return an error if they are not null?

https://chromiumcodereview.appspot.com/25675009/diff/1/runtime/vm/dart_api_im...
runtime/vm/dart_api_impl.cc:3068: // See if we are trying to invoke a
constructor here.
Wouldn't target be a type to call a constructor?
Or is target an already allocated instance of the correct type, but not a
constructed one? If so, this will not work for a factory call.

https://chromiumcodereview.appspot.com/25675009/diff/1/runtime/vm/dart_api_im...
runtime/vm/dart_api_impl.cc:3070: // Constuct name of the constructor to invoke.
construct

[siva, 2013-10-04 18:32:56]

As discussed offline I have added a new method
Dart_InvokeConstructor which calls a generative constructor
on an object that has already been allocated using
Dart_Allocate.

https://chromiumcodereview.appspot.com/25675009/diff/1/runtime/vm/dart_api_im...
File runtime/vm/dart_api_impl.cc (right):

https://chromiumcodereview.appspot.com/25675009/diff/1/runtime/vm/dart_api_im...
runtime/vm/dart_api_impl.cc:3035: const Class& cls = Class::Handle(isolate,
Type::Cast(obj).type_class());
We don't expect to call constructors using this method.

On 2013/10/04 00:03:09, regis wrote:
> So, target is a type and we use its type class to resolve the function name,
but
> we ignore its type arguments (which only make sense if we call a constructor
or
> a factory). Should we return an error if they are not null?

https://chromiumcodereview.appspot.com/25675009/diff/1/runtime/vm/dart_api_im...
runtime/vm/dart_api_impl.cc:3068: // See if we are trying to invoke a
constructor here.
Target is an already allocated instance.

On 2013/10/04 00:03:09, regis wrote:
> Wouldn't target be a type to call a constructor?
> Or is target an already allocated instance of the correct type, but not a
> constructed one? If so, this will not work for a factory call.

https://chromiumcodereview.appspot.com/25675009/diff/1/runtime/vm/dart_api_im...
runtime/vm/dart_api_impl.cc:3070: // Constuct name of the constructor to invoke.
On 2013/10/04 00:03:09, regis wrote:
> construct

Done.

[siva, 2013-10-04 18:33:07]

PTAL.

[regis, 2013-10-04 19:35:16]

LGTM

https://chromiumcodereview.appspot.com/25675009/diff/13001/runtime/include/da...
File runtime/include/dart_api.h (right):

https://chromiumcodereview.appspot.com/25675009/diff/13001/runtime/include/da...
runtime/include/dart_api.h:1835: * The 'target' parameter must be and object.
be an object

[siva, 2013-10-04 19:48:10]

https://chromiumcodereview.appspot.com/25675009/diff/13001/runtime/include/da...
File runtime/include/dart_api.h (right):

https://chromiumcodereview.appspot.com/25675009/diff/13001/runtime/include/da...
runtime/include/dart_api.h:1835: * The 'target' parameter must be and object.
On 2013/10/04 19:35:17, regis wrote:
> be an object

Done.

[siva, 2013-10-04 20:00:51]

Committed patchset #4 manually as r28276 (presubmit successful).