Reset Source modification stamp to -1 if it does not exist.

Reset Source modification stamp to -1 if it does not exist.

R=brianwilkerson@google.com
BUG=

Committed: https://github.com/dart-lang/sdk/commit/27a8bbd41537458260ee61d609e852d6292a7efa

[Brian Wilkerson, 2015-09-23 13:53:38]

https://codereview.chromium.org/1361003002/diff/1/pkg/analyzer/lib/src/contex...
File pkg/analyzer/lib/src/context/context.dart (right):

https://codereview.chromium.org/1361003002/diff/1/pkg/analyzer/lib/src/contex...
pkg/analyzer/lib/src/context/context.dart:1776: entry.modificationTime = -1;
Does this need to set the modification stamp for all of the entries for the
source (similar to line 1770)? If not, is the logic on line 1770 still needed?

https://codereview.chromium.org/1361003002/diff/1/pkg/analyzer/test/src/conte...
File pkg/analyzer/test/src/context/context_test.dart (right):

https://codereview.chromium.org/1361003002/diff/1/pkg/analyzer/test/src/conte...
pkg/analyzer/test/src/context/context_test.dart:1775: expect(source.readCount,
2);
I don't understand why this change would cause the source to be read more times.
That seems like a problem.

[scheglov, 2015-09-23 15:11:27]

https://codereview.chromium.org/1361003002/diff/1/pkg/analyzer/lib/src/contex...
File pkg/analyzer/lib/src/context/context.dart (right):

https://codereview.chromium.org/1361003002/diff/1/pkg/analyzer/lib/src/contex...
pkg/analyzer/lib/src/context/context.dart:1776: entry.modificationTime = -1;
On 2015/09/23 13:53:38, Brian Wilkerson wrote:
> Does this need to set the modification stamp for all of the entries for the
> source (similar to line 1770)? If not, is the logic on line 1770 still needed?

In theory yes, but practically we invalidate everything at the line 1812.

I'm sorry that it hard to see now because of the work-in-progress-never-finished
limiting of invalidation.

https://codereview.chromium.org/1361003002/diff/1/pkg/analyzer/test/src/conte...
File pkg/analyzer/test/src/context/context_test.dart (right):

https://codereview.chromium.org/1361003002/diff/1/pkg/analyzer/test/src/conte...
pkg/analyzer/test/src/context/context_test.dart:1775: expect(source.readCount,
2);
On 2015/09/23 13:53:38, Brian Wilkerson wrote:
> I don't understand why this change would cause the source to be read more
times.
> That seems like a problem.

The scenario is following.

1. We add test.dart as not existing source in _addSourceWithException2(), so its
modificationStamp is -1.

2. GetContentTask attempts to read it (1-st time), fails, uses an empty string.

3. Then in the test we make test.dart existing again, so newly added
validateCacheConsistency() invocation in _analyzeAll_assertFinished() notices
that test.dart CacheEntry.modificationTime(-1) != source.modificationTime(0). It
marks the source as changed.

4. In _sourceChanged() we attempt to read the source again (2-nd time), get an
exception, and set modificationTime to -1.

  Basically we get this change because of adding
context.validateCacheConsistency() invocation.

[Brian Wilkerson, 2015-09-23 15:15:57]

LGTM

[scheglov, 2015-09-23 15:20:17]

Committed patchset #1 (id:1) manually as
27a8bbd41537458260ee61d609e852d6292a7efa (presubmit successful).