Further reduce use of Element in codegen.

Further reduce use of Element in codegen.

R=sigmund@google.com

Committed: https://github.com/dart-lang/sdk/commit/fad0fe5d86203bd2dd598d37539eba541a1ffa9c

[Johnni Winther, 2017-01-02 15:30:16]

johnniwinther@google.com changed reviewers:
+ sigmund@google.com

[Johnni Winther, 2017-01-03 10:03:37]

ping

[Siggi Cherem (dart-lang), 2017-01-03 17:39:37]

lgtm

https://codereview.chromium.org/2609063002/diff/1/pkg/compiler/lib/src/univer...
File pkg/compiler/lib/src/universe/world_builder.dart (right):

https://codereview.chromium.org/2609063002/diff/1/pkg/compiler/lib/src/univer...
pkg/compiler/lib/src/universe/world_builder.dart:1109: void
forEachInstanceField(
I like the move of this out of the entities.

Couple questions:
 * Does this API include all fields or just fields that are in use (not
tree-shaken)? I'm guessing it's the former, but either way, it might be good to
add a sentence in the dartdoc to be explicit. If we are only including used
fields, consider renaming this to forEachUsedInstanceField (similar to how all
the forEachInvoked* methods below).

 * should we add this API to some other interface too (like
WorldBuilder/ClosedWorld)? It might be too early to tell, but from a quick
glance it seems we use element.forEachInstanceField in a few other places
(constants, creating inference graph, ssa builder). I'm OK crossing that bridge
when we get there and not on this CL, up to you.

[Johnni Winther, 2017-01-04 10:39:27]

Description was changed from

==========
Further reduce use of Element in codegen.
==========

to

==========
Further reduce use of Element in codegen.

R=sigmund@google.com

Committed:
https://github.com/dart-lang/sdk/commit/fad0fe5d86203bd2dd598d37539eba541a1ffa9c
==========

[Johnni Winther, 2017-01-04 10:39:28]

Committed patchset #1 (id:1) manually as
fad0fe5d86203bd2dd598d37539eba541a1ffa9c (presubmit successful).

[Johnni Winther, 2017-01-04 10:39:49]

https://codereview.chromium.org/2609063002/diff/1/pkg/compiler/lib/src/univer...
File pkg/compiler/lib/src/universe/world_builder.dart (right):

https://codereview.chromium.org/2609063002/diff/1/pkg/compiler/lib/src/univer...
pkg/compiler/lib/src/universe/world_builder.dart:1109: void
forEachInstanceField(
> Couple questions:
>  * Does this API include all fields or just fields that are in use (not
> tree-shaken)? I'm guessing it's the former, but either way, it might be good
to
> add a sentence in the dartdoc to be explicit. If we are only including used
> fields, consider renaming this to forEachUsedInstanceField (similar to how all
> the forEachInvoked* methods below).

Currently all, in time it should be at the world builders discretion. We should
at some point in time (again) be able to tree-shake fields (based on resolution
closed world knowledge) and the caller of this function shouldn't know or care.

>  * should we add this API to some other interface too (like
> WorldBuilder/ClosedWorld)? It might be too early to tell, but from a quick
> glance it seems we use element.forEachInstanceField in a few other places
> (constants, creating inference graph, ssa builder). I'm OK crossing that
bridge
> when we get there and not on this CL, up to you.

I expect it to be in WorldBuilder/ClosedWorld and be used elsewhere, but
currently I'm just growing the interfaces slowly by what is needed by the
refactored use cases.