In constant evaluation, handle final vars initialized at declaration site.

In constant evaluation, handle final vars initialized at declaration site.

Previously final variables initialized at the declaration site
would simply be ignored, causing some checked-mode compile time
errors to be missed, and causing the analyzer to produce
incorrect values for any such constants.

BUG=dartbug.com/23292
R=brianwilkerson@google.com

Committed: https://code.google.com/p/dart/source/detail?r=45494

[Paul Berry, 2015-04-21 21:44:53]

paulberry@google.com changed reviewers:
+ brianwilkerson@google.com

[Brian Wilkerson, 2015-04-22 02:44:00]

LGTM

https://codereview.chromium.org/1099953004/diff/1/pkg/analyzer/lib/src/genera...
File pkg/analyzer/lib/src/generated/resolver.dart (right):

https://codereview.chromium.org/1099953004/diff/1/pkg/analyzer/lib/src/genera...
pkg/analyzer/lib/src/generated/resolver.dart:11312: // evaluate the const
constructor).
Do we really need the AST structure? The initializer for a final field has to be
a constant expression. We should just need the value, not the ability to
evaluate it each time we find an invocation of the constructor.

[Paul Berry, 2015-04-24 18:06:34]

https://codereview.chromium.org/1099953004/diff/1/pkg/analyzer/lib/src/genera...
File pkg/analyzer/lib/src/generated/resolver.dart (right):

https://codereview.chromium.org/1099953004/diff/1/pkg/analyzer/lib/src/genera...
pkg/analyzer/lib/src/generated/resolver.dart:11312: // evaluate the const
constructor).
On 2015/04/22 02:44:00, Brian Wilkerson wrote:
> Do we really need the AST structure? The initializer for a final field has to
be
> a constant expression. We should just need the value, not the ability to
> evaluate it each time we find an invocation of the constructor.

(Capturing the result of an in-person discussion)

Yes, we need it for integration with the new task model.  Otherwise at the time
that we evaluate the constant there is no guarantee that the AST will still be
around (or, if it is still around, that we'll be able to get to it).  And we
can't just carry around a pointer to the original AST, since the targets that
will be used for constant evaluation in the new task model will be long-lived,
and we don't want to prevent the garbage collector from collecting the AST once
analysis of a file is done.

[Paul Berry, 2015-05-04 16:22:10]

Committed patchset #1 (id:1) manually as 45494 (presubmit successful).