Fix summary handling of unresolved imports, exports, and parts.

Fix summary handling of unresolved imports, exports, and parts.

Previously this was working for a few use cases by dumb luck, but it
wasn't well tested and became broken by
b29c6bf33000ca129987edffe9e5df0fde793f3b.  This CL fixes it for real
and adds tests to verify the fix.

Note that there is a change to how we represent an unresolved
import/export: instead of storing a URI_EXISTS modifier in the element
model, we simply mark the imported library element as synthetic.
(This library element existed anyway; we just weren't marking it as
synthetic).  This makes it easy to tie in with summaries, since it is
easy for the resynthesizer to detect that the library doesn't exist at
the time the library handle is resolved.

R=brianwilkerson@google.com

Committed: https://github.com/dart-lang/sdk/commit/052a6c867de08e493127e5aaa4d02941ac31d2f8

[Paul Berry, 2016-08-11 23:15:15]

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

[Brian Wilkerson, 2016-08-11 23:49:36]

lgtm

https://codereview.chromium.org/2235373003/diff/1/pkg/analyzer/test/src/summa...
File pkg/analyzer/test/src/summary/resynthesize_test.dart (right):

https://codereview.chromium.org/2235373003/diff/1/pkg/analyzer/test/src/summa...
pkg/analyzer/test/src/summary/resynthesize_test.dart:53: * Tests may set this to
`true` to indicate that a missing file at the time of
Seems odd to talk about setting a getter to `true`. :-)

I haven't thought about it very hard, but it also seems strange to make this
abstract when most of the overrides are "return false". Seems like it would be
easier to subclass this class if it just returned `false`, or was a field
initialized to `false`, but you probably had a reason for not doing that.

[Paul Berry, 2016-08-12 20:56:51]

https://codereview.chromium.org/2235373003/diff/1/pkg/analyzer/test/src/summa...
File pkg/analyzer/test/src/summary/resynthesize_test.dart (right):

https://codereview.chromium.org/2235373003/diff/1/pkg/analyzer/test/src/summa...
pkg/analyzer/test/src/summary/resynthesize_test.dart:53: * Tests may set this to
`true` to indicate that a missing file at the time of
On 2016/08/11 23:49:35, Brian Wilkerson wrote:
> Seems odd to talk about setting a getter to `true`. :-)
> 
> I haven't thought about it very hard, but it also seems strange to make this
> abstract when most of the overrides are "return false". Seems like it would be
> easier to subclass this class if it just returned `false`, or was a field
> initialized to `false`, but you probably had a reason for not doing that.

Resolved in an offline discussion.  There was a slight complication due to a
strong mode error (a getter can't override a field, even if the getter is
abstract).  I've worked around that problem and made a request to see if we can
loosen the strong mode restriction.

[Paul Berry, 2016-08-12 20:59:54]

Description was changed from

==========
Fix summary handling of unresolved imports, exports, and parts.

Previously this was working for a few use cases by dumb luck, but it
wasn't well tested and became broken by
b29c6bf33000ca129987edffe9e5df0fde793f3b.  This CL fixes it for real
and adds tests to verify the fix.

Note that there is a change to how we represent an unresolved
import/export: instead of storing a URI_EXISTS modifier in the element
model, we simply mark the imported library element as synthetic.
(This library element existed anyway; we just weren't marking it as
synthetic).  This makes it easy to tie in with summaries, since it is
easy for the resynthesizer to detect that the library doesn't exist at
the time the library handle is resolved.
==========

to

==========
Fix summary handling of unresolved imports, exports, and parts.

Previously this was working for a few use cases by dumb luck, but it
wasn't well tested and became broken by
b29c6bf33000ca129987edffe9e5df0fde793f3b.  This CL fixes it for real
and adds tests to verify the fix.

Note that there is a change to how we represent an unresolved
import/export: instead of storing a URI_EXISTS modifier in the element
model, we simply mark the imported library element as synthetic.
(This library element existed anyway; we just weren't marking it as
synthetic).  This makes it easy to tie in with summaries, since it is
easy for the resynthesizer to detect that the library doesn't exist at
the time the library handle is resolved.

R=brianwilkerson@google.com

Committed:
https://github.com/dart-lang/sdk/commit/052a6c867de08e493127e5aaa4d02941ac31d2f8
==========

[Paul Berry, 2016-08-12 20:59:55]

Committed patchset #2 (id:20001) manually as
052a6c867de08e493127e5aaa4d02941ac31d2f8 (presubmit successful).