fix #607, add support for package config file

fix #607, add support for package config file

[Jennifer Messerly, 2016-07-27 22:56:15]

jmesserly@google.com changed reviewers:
+ nweiz@google.com, pquitslund@google.com

[Jennifer Messerly, 2016-07-27 22:56:16]

Hi Natalie & Phil,

This CL adds support for .packages to DDC.

Does this look vaguely correct? I-have-no-idea-what-I'm-doing :)

It does pass DDC's presubmit and a simple test case seems to work correctly.

https://codereview.chromium.org/2188033002/diff/40001/lib/src/analyzer/contex...
File lib/src/analyzer/context.dart (right):

https://codereview.chromium.org/2188033002/diff/40001/lib/src/analyzer/contex...
lib/src/analyzer/context.dart:203: packages =
findPackagesFromFile(Directory.current.uri);
is using .packages the right default behavior now?

[nweiz, 2016-07-27 23:15:11]

https://codereview.chromium.org/2188033002/diff/40001/lib/src/analyzer/contex...
File lib/src/analyzer/context.dart (right):

https://codereview.chromium.org/2188033002/diff/40001/lib/src/analyzer/contex...
lib/src/analyzer/context.dart:97: 'cannot be used with --package-root.')
It would be good to explicitly throw an error if both of these are provided.

https://codereview.chromium.org/2188033002/diff/40001/lib/src/analyzer/contex...
lib/src/analyzer/context.dart:203: packages =
findPackagesFromFile(Directory.current.uri);
On 2016/07/27 22:56:16, John Messerly wrote:
> is using .packages the right default behavior now?

I believe the default is:

* If a packages/ directory exists next to the entrypoint, use that.
* Otherwise, traverse upwards through the filesystem, starting at the
entrypoint's directory, to find a ".packages" file and use that.

Since DDC doesn't really have an "entrypoint" as such, I'm not sure how to make
this work.

[Jennifer Messerly, 2016-07-28 05:18:15]

In light of https://github.com/dart-lang/dev_compiler/issues/611, I may just
rework this so we can use analyzer_cli code, probably by moving it down into
pkg:analyzer.

It's totally, completely bonkers that DDC is duplicating all of this Analyzer
config logic. Only reason I didn't reuse analyzer_cli stuff is it's not
available as public API =(

[pquitslund, 2016-07-28 16:23:28]

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

[pquitslund, 2016-07-28 16:23:59]

On 2016/07/28 05:18:15, John Messerly wrote:
> In light of https://github.com/dart-lang/dev_compiler/issues/611, I may just
> rework this so we can use analyzer_cli code, probably by moving it down into
> pkg:analyzer.
> 
> It's totally, completely bonkers that DDC is duplicating all of this Analyzer
> config logic. Only reason I didn't reuse analyzer_cli stuff is it's not
> available as public API =(

We've talked about this * a lot*.  There's an extraordinary amount of
duplication between the various clients of the analyzer package (cli, ddc,
dartdoc, flutter analyze, linter, ...).  The good news is we're making some
progress towards improving that.  I added Brian to the reviewer list so he can
chime in but we should definitely schedule some time to discuss.

[Jennifer Messerly, 2016-07-28 16:36:33]

On 2016/07/28 16:23:59, pquitslund wrote:
> On 2016/07/28 05:18:15, John Messerly wrote:
> > In light of https://github.com/dart-lang/dev_compiler/issues/611, I may just
> > rework this so we can use analyzer_cli code, probably by moving it down into
> > pkg:analyzer.
> > 
> > It's totally, completely bonkers that DDC is duplicating all of this
Analyzer
> > config logic. Only reason I didn't reuse analyzer_cli stuff is it's not
> > available as public API =(
> 
> We've talked about this * a lot*.  There's an extraordinary amount of
> duplication between the various clients of the analyzer package (cli, ddc,
> dartdoc, flutter analyze, linter, ...).  The good news is we're making some
> progress towards improving that.  I added Brian to the reviewer list so he can
> chime in but we should definitely schedule some time to discuss.

ooooooh! that would be wonderful. let me know if I can help :D

[Brian Wilkerson, 2016-07-29 17:07:40]

I'm slowly, but surely, making progress on getting a single unified API for
building a context based on a set of analysis roots (the things users open in
IDE's / editors for analysis by server). Happy to talk about how to make this
happen faster for DDC's use.

https://codereview.chromium.org/2188033002/diff/40001/lib/src/analyzer/contex...
File lib/src/analyzer/context.dart (right):

https://codereview.chromium.org/2188033002/diff/40001/lib/src/analyzer/contex...
lib/src/analyzer/context.dart:203: packages =
findPackagesFromFile(Directory.current.uri);
Almost. A '.packages' file in the initial directory trumps a 'packages'
directory, but a 'packages' directory in the initial directory is used before
any '.packages' files in parent directories.