Validate incremental resolutions results if requested.

Validate incremental resolutions results if requested.

It works by performing incremental resolution, remembering its results and
then pretending that incremental resolution did not happen. Later, after
the full resolution, we compare "full" result with the incremental one.
If there is a problem, it is sent to the instrumentation.

R=brianwilkerson@google.com, danrubel@google.com
BUG=

Committed: https://code.google.com/p/dart/source/detail?r=42710

[danrubel, 2015-01-07 22:32:48]

https://codereview.chromium.org/839913002/diff/1/pkg/analyzer/lib/src/generat...
File pkg/analyzer/lib/src/generated/engine.dart (right):

https://codereview.chromium.org/839913002/diff/1/pkg/analyzer/lib/src/generat...
pkg/analyzer/lib/src/generated/engine.dart:2245:
assertSameResolution(incrementalResolutionValidation_lastUnit, fullUnit);
Should this be asserting valid types?

https://codereview.chromium.org/839913002/diff/1/pkg/analyzer/lib/src/generat...
pkg/analyzer/lib/src/generated/engine.dart:5161: // if validation, remember the
result, but throw it away
Can we switch this around so that it remembers the incremental solution so that
code completion is still fast, but verifies it after all other tasks are
complete?

https://codereview.chromium.org/839913002/diff/1/pkg/analyzer/lib/src/generat...
File pkg/analyzer/lib/src/generated/incremental_resolution_validator.dart
(right):

https://codereview.chromium.org/839913002/diff/1/pkg/analyzer/lib/src/generat...
pkg/analyzer/lib/src/generated/incremental_resolution_validator.dart:16: {bool
validateTypes: false}) {
validateTypes true by default?

[scheglov, 2015-01-07 23:24:11]

https://codereview.chromium.org/839913002/diff/1/pkg/analyzer/lib/src/generat...
File pkg/analyzer/lib/src/generated/engine.dart (right):

https://codereview.chromium.org/839913002/diff/1/pkg/analyzer/lib/src/generat...
pkg/analyzer/lib/src/generated/engine.dart:2245:
assertSameResolution(incrementalResolutionValidation_lastUnit, fullUnit);
On 2015/01/07 22:32:48, danrubel wrote:
> Should this be asserting valid types?

We should, but we cannot.
See my message about Elements equality.

We can work it around for compering elements themselves, but DartTypes also
compare elements, so it still fails if we try.

https://codereview.chromium.org/839913002/diff/1/pkg/analyzer/lib/src/generat...
pkg/analyzer/lib/src/generated/engine.dart:5161: // if validation, remember the
result, but throw it away
On 2015/01/07 22:32:48, danrubel wrote:
> Can we switch this around so that it remembers the incremental solution so
that
> code completion is still fast, but verifies it after all other tasks are
> complete?

Unfortunately I don't see how to make it work.
If we don't ignore incremental results, we don't get "full" results from tasks
:-(

[Brian Wilkerson, 2015-01-08 00:24:36]

LGTM

[scheglov, 2015-01-08 18:57:29]

Committed patchset #1 (id:1) manually as 42710 (presubmit successful).