Don't load dependencies' useless transformers.

Don't load dependencies' useless transformers.

If we can tell (using $include/$exclude) that a dependency's
transformer can't run on any public files in that package, don't
bother loading that transformer at all.

R=rnystrom@google.com
BUG=17534
Committed: https://code.google.com/p/dart/source/detail?r=37925

[Bob Nystrom, 2014-07-01 17:15:39]

Do you have use cases that are improved by this optimization?

https://codereview.chromium.org/363543003/diff/1/sdk/lib/_internal/pub/lib/sr...
File sdk/lib/_internal/pub/lib/src/barback/transformer_config.dart (right):

https://codereview.chromium.org/363543003/diff/1/sdk/lib/_internal/pub/lib/sr...
sdk/lib/_internal/pub/lib/src/barback/transformer_config.dart:58: bool get
canTransformLib {
You'll need to consider "bin" too for pub run.

https://codereview.chromium.org/363543003/diff/1/sdk/lib/_internal/pub/lib/sr...
sdk/lib/_internal/pub/lib/src/barback/transformer_config.dart:60: return
includes.any((path) => p.url.dirname(path) == 'lib');
Won't this fail on "notlib/lib/something.txt"? How about:

p.url.isWithin(path, "lib")

Also, what about excludes?

https://codereview.chromium.org/363543003/diff/1/sdk/lib/_internal/pub/test/t...
File
sdk/lib/_internal/pub/test/transformers_needed_by_transformers/dev_transformers_test.dart
(right):

https://codereview.chromium.org/363543003/diff/1/sdk/lib/_internal/pub/test/t...
sdk/lib/_internal/pub/test/transformers_needed_by_transformers/dev_transformers_test.dart:38:
integration("doesreturn the root package's transformer that can't run on lib",
Space after "does".

[nweiz, 2014-07-01 22:18:39]

code review

[nweiz, 2014-07-01 22:19:10]

Apparently DI uses test-only transformers:
http://code.google.com/p/dart/issues/detail?id=17534

https://codereview.chromium.org/363543003/diff/1/sdk/lib/_internal/pub/lib/sr...
File sdk/lib/_internal/pub/lib/src/barback/transformer_config.dart (right):

https://codereview.chromium.org/363543003/diff/1/sdk/lib/_internal/pub/lib/sr...
sdk/lib/_internal/pub/lib/src/barback/transformer_config.dart:58: bool get
canTransformLib {
On 2014/07/01 17:15:39, Bob Nystrom wrote:
> You'll need to consider "bin" too for pub run.

Done.

https://codereview.chromium.org/363543003/diff/1/sdk/lib/_internal/pub/lib/sr...
sdk/lib/_internal/pub/lib/src/barback/transformer_config.dart:60: return
includes.any((path) => p.url.dirname(path) == 'lib');
On 2014/07/01 17:15:39, Bob Nystrom wrote:
> Won't this fail on "notlib/lib/something.txt"? How about:
> 
> p.url.isWithin(path, "lib")

Oh right, somehow I was thinking that dirname only returned the first directory
component. Done.

> Also, what about excludes?

At the moment it's not possible to exclude entire directories, so there's no way
for an exclusion to guarantee that no public files will be processed.

https://codereview.chromium.org/363543003/diff/1/sdk/lib/_internal/pub/test/t...
File
sdk/lib/_internal/pub/test/transformers_needed_by_transformers/dev_transformers_test.dart
(right):

https://codereview.chromium.org/363543003/diff/1/sdk/lib/_internal/pub/test/t...
sdk/lib/_internal/pub/test/transformers_needed_by_transformers/dev_transformers_test.dart:38:
integration("doesreturn the root package's transformer that can't run on lib",
On 2014/07/01 17:15:39, Bob Nystrom wrote:
> Space after "does".

Done.

[Bob Nystrom, 2014-07-01 23:47:08]

LGTM!

[nweiz, 2014-07-02 00:14:28]

Committed patchset #2 manually as r37925 (presubmit successful).