Be smarter about when disabling tree-shaking.

Be smarter about when to disable tree-shaking.

BUG=http://dartbug.com/11218
R=johnniwinther@google.com, ngeoffray@google.com

Committed: https://code.google.com/p/dart/source/detail?r=24027

[ahe, 2013-06-12 18:14:06]

An example like this:

import 'dart:mirrors';

class Foo {
  noSuchMethod(invocation) {
    print('Invoked ${MirrorSystem.getName(invocation.memberName)}');
    return reflect('foobar').delegate(invocation);
  }
}

void main() {
  print(new Foo().substring(3));
}

Compiles to 817K because I disabled tree-shaking whenever dart:mirrors is
imported.  Now it is a bit smarter and compiles to 60K.

I should be able to make the output even smaller by removing the use of
MirrorSystem.getName, but that'll wait for another CL.

[ngeoffray, 2013-06-12 19:38:42]

LGTM!

https://codereview.chromium.org/16817002/diff/2001/dart/sdk/lib/_internal/com...
File dart/sdk/lib/_internal/compiler/implementation/compiler.dart (right):

https://codereview.chromium.org/16817002/diff/2001/dart/sdk/lib/_internal/com...
dart/sdk/lib/_internal/compiler/implementation/compiler.dart:531: bool get
compileAll => false;
Why do you want to keep this?

https://codereview.chromium.org/16817002/diff/2001/dart/sdk/lib/_internal/lib...
File dart/sdk/lib/_internal/lib/js_mirrors.dart (right):

https://codereview.chromium.org/16817002/diff/2001/dart/sdk/lib/_internal/lib...
dart/sdk/lib/_internal/lib/js_mirrors.dart:26: /// No-op method that is called
to infrom the compiler that unmangled
infrom -> inform

[Johnni Winther, 2013-06-13 07:08:28]

lgtm

https://codereview.chromium.org/16817002/diff/2001/dart/sdk/lib/_internal/com...
File dart/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart
(right):

https://codereview.chromium.org/16817002/diff/2001/dart/sdk/lib/_internal/com...
dart/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart:1137: }
Something missing in this block?

https://codereview.chromium.org/16817002/diff/2001/dart/tests/compiler/dart2j...
File dart/tests/compiler/dart2js/mirror_tree_shaking_test.dart (right):

https://codereview.chromium.org/16817002/diff/2001/dart/tests/compiler/dart2j...
dart/tests/compiler/dart2js/mirror_tree_shaking_test.dart:5: // Test that no
parts are emitted when deferred loading isn't used.
Update comment.

[ahe, 2013-06-14 12:00:22]

Thank you, Nicolas and Johnni!

https://codereview.chromium.org/16817002/diff/2001/dart/sdk/lib/_internal/com...
File dart/sdk/lib/_internal/compiler/implementation/compiler.dart (right):

https://codereview.chromium.org/16817002/diff/2001/dart/sdk/lib/_internal/com...
dart/sdk/lib/_internal/compiler/implementation/compiler.dart:531: bool get
compileAll => false;
On 2013/06/12 19:38:42, ngeoffray wrote:
> Why do you want to keep this?

I think it is useful for testing.  We should add a test that compiles all the
libraries.

https://codereview.chromium.org/16817002/diff/2001/dart/sdk/lib/_internal/com...
File dart/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart
(right):

https://codereview.chromium.org/16817002/diff/2001/dart/sdk/lib/_internal/com...
dart/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart:1137: }
On 2013/06/13 07:08:29, Johnni Winther wrote:
> Something missing in this block?

Yes.  I'll fill in more stuff in future CLs.

https://codereview.chromium.org/16817002/diff/2001/dart/sdk/lib/_internal/lib...
File dart/sdk/lib/_internal/lib/js_mirrors.dart (right):

https://codereview.chromium.org/16817002/diff/2001/dart/sdk/lib/_internal/lib...
dart/sdk/lib/_internal/lib/js_mirrors.dart:26: /// No-op method that is called
to infrom the compiler that unmangled
On 2013/06/12 19:38:42, ngeoffray wrote:
> infrom -> inform

Done.

https://codereview.chromium.org/16817002/diff/2001/dart/tests/compiler/dart2j...
File dart/tests/compiler/dart2js/mirror_tree_shaking_test.dart (right):

https://codereview.chromium.org/16817002/diff/2001/dart/tests/compiler/dart2j...
dart/tests/compiler/dart2js/mirror_tree_shaking_test.dart:5: // Test that no
parts are emitted when deferred loading isn't used.
On 2013/06/13 07:08:29, Johnni Winther wrote:
> Update comment.

Done.

[ahe, 2013-06-14 12:43:42]

Committed patchset #2 manually as r24027 (presubmit successful).