fix #30138, synethic nodes causing crash generating source maps

fix #30138, synethic nodes causing crash generating source maps

R=vsm@google.com

Committed: https://github.com/dart-lang/sdk/commit/52880e9c4c028fbd992dceac7de4499a2fb8e3be

[Jennifer Messerly, 2017-07-14 07:51:34]

jmesserly@google.com changed reviewers:
+ vsm@google.com

[Jennifer Messerly, 2017-07-14 07:51:35]

Now that I'm looking at this, I've got some source map optimization ideas for a
follow up CL. But this fixes the bug. :)

https://codereview.chromium.org/2977943002/diff/1/pkg/dev_compiler/lib/src/co...
File pkg/dev_compiler/lib/src/compiler/code_generator.dart (right):

https://codereview.chromium.org/2977943002/diff/1/pkg/dev_compiler/lib/src/co...
pkg/dev_compiler/lib/src/compiler/code_generator.dart:586:
_currentElements.add(unit.element);
refactor: this will help us know what source we're in. With this change, we
could move source location computation into this file in a future CL if we want

https://codereview.chromium.org/2977943002/diff/1/pkg/dev_compiler/lib/src/co...
pkg/dev_compiler/lib/src/compiler/code_generator.dart:2364:
.toAssignExpression(js.call('this.#', [access]))
this will help MetaLet generate cleaner code in some cases.

possibly we should integrate that feature directly into js_ast builder.dart,
though, because the old code is arguably cleaner. Anyways thoughts for future
stuff, I'll add a note to our MetaLet issue

https://codereview.chromium.org/2977943002/diff/1/pkg/dev_compiler/lib/src/co...
pkg/dev_compiler/lib/src/compiler/code_generator.dart:2474: null, // don't
annotate as this breaks stepping for one-line functions.
refactor: rather than do an `is` check inside the printer, we can just do it
here

https://codereview.chromium.org/2977943002/diff/1/pkg/dev_compiler/lib/src/co...
File pkg/dev_compiler/lib/src/compiler/source_map_printer.dart (right):

https://codereview.chromium.org/2977943002/diff/1/pkg/dev_compiler/lib/src/co...
pkg/dev_compiler/lib/src/compiler/source_map_printer.dart:22: Uri _sourceUri;
there's more refactoring in this file. please see patch set 2

https://codereview.chromium.org/2977943002/diff/20001/pkg/dev_compiler/lib/sr...
File pkg/dev_compiler/lib/src/compiler/source_map_printer.dart (left):

https://codereview.chromium.org/2977943002/diff/20001/pkg/dev_compiler/lib/sr...
pkg/dev_compiler/lib/src/compiler/source_map_printer.dart:66: if (node is
MethodDeclaration) return;
this was fixed in CodeGenerator

https://codereview.chromium.org/2977943002/diff/20001/pkg/dev_compiler/lib/sr...
File pkg/dev_compiler/lib/src/compiler/source_map_printer.dart (right):

https://codereview.chromium.org/2977943002/diff/20001/pkg/dev_compiler/lib/sr...
pkg/dev_compiler/lib/src/compiler/source_map_printer.dart:55: if (unit == null)
return;
this is the actual 1-line fix :)

https://codereview.chromium.org/2977943002/diff/20001/pkg/dev_compiler/lib/sr...
pkg/dev_compiler/lib/src/compiler/source_map_printer.dart:64: if
(_sourceUri.scheme == 'package') {
refactored this to figure out what was going on. We were converting back and
forth between strings and URIs needlessly. dart: and file: keep their URIs. Only
package: does not. This should match old behavior.

[vsm, 2017-07-14 14:22:38]

lgtm

[Jennifer Messerly, 2017-07-14 19:46:28]

Description was changed from

==========
fix #30138, synethic nodes causing crash generating source maps
==========

to

==========
fix #30138, synethic nodes causing crash generating source maps

R=vsm@google.com

Committed:
https://github.com/dart-lang/sdk/commit/52880e9c4c028fbd992dceac7de4499a2fb8e3be
==========

[Jennifer Messerly, 2017-07-14 19:46:30]

Committed patchset #2 (id:20001) manually as
52880e9c4c028fbd992dceac7de4499a2fb8e3be (presubmit successful).