Before: `NoSuchMethodError: The method 'FfiTrampoline' was called on
null.`
After: `Invalid argument(s): argument value for ':ffi_param2' is null`.
Makes the ArgumentNullError RTE lookup the name of the argument in the
code source map when reporting a null argument.
Makes the FFI call arguments and FFI callbacks use kArgumentError
instead of the default kNoSuchMethod so that we target this RTE instead.
This changes the Error type from `NoSuchMethodError` to `ArgumentError`.
Because `Error`s should not be caught [1], this is fine.
Since FFI trampolines are created from type arguments, the arguments do
not have names. The arguments are assigned names programmatically. See
the related bug.
Also, this CL cleans up the SourcePosition of the `CheckNullOptimized`,
it was never passed.
[1] https://dart.dev/guides/language/effective-dart/usage#dont-explicitly-catch-error-or-types-that-implement-it
TEST=tests/ffi/function_test.dart
Closes: https://github.com/dart-lang/sdk/issues/47094
Bug: https://github.com/dart-lang/sdk/issues/36780
Change-Id: I15e7de4d026e034bde0eda3ba7fe3785f0da5057
Cq-Include-Trybots: luci.dart.try:vm-precomp-ffi-qemu-linux-release-arm-try,vm-ffi-android-debug-arm-try,vm-kernel-precomp-dwarf-linux-product-x64-try,vm-kernel-precomp-linux-debug-x64-try,app-kernel-linux-debug-x64-try,vm-kernel-reload-rollback-linux-debug-x64-try,vm-kernel-reload-linux-debug-x64-try,vm-ffi-android-debug-arm64-try,vm-kernel-nnbd-mac-debug-x64-try,vm-kernel-precomp-nnbd-linux-debug-x64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/212462
Commit-Queue: Daco Harkes <dacoharkes@google.com>
Reviewed-by: Clement Skau <cskau@google.com>
Reviewed-by: Tess Strickland <sstrickl@google.com>
As a side-effect of making closures without captured variables have an
empty context, we not only avoid a memory leak, but also allow such
closures to be sent across [SendPort]s.
Issue https://github.com/dart-lang/sdk/issues/36983
Issue https://github.com/dart-lang/sdk/issues/45603
TEST=vm/dart{_2,}/isolates/closures_without_captured_variables_test
Change-Id: I5e8845203059ff625f7cff3f072d845b5e48ba36
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/212297
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Slava Egorov <vegorov@google.com>
Change-Id: Ia1c5b6b2365849a6c69b1db2bf1878ca64dfd65b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/211420
Reviewed-by: Paul Berry <paulberry@google.com>
Reviewed-by: Erik Ernst <eernst@google.com>
Commit-Queue: Lasse R.H. Nielsen <lrn@google.com>
This makes the self-detection of whether isolate groups are enabled work
correctly in the test.
TEST=Fixes lib_2/isolate/message3_test test failures on CI
Change-Id: I71965236444af71e6deb4df6a77911144af9af91
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/212294
Auto-Submit: Martin Kustermann <kustermann@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>
Closures can be shared if they have no state they capture (i.e. a null
context). Otherwise we copy them by also transitively copying the
parent context chain.
Issue https://github.com/dart-lang/sdk/issues/36097
TEST=Added tests to vm/dart{,_2}/isolates/fast_object_copy{,2}_test
Change-Id: Ie641b97806edd0c21f0a8d5c514f8e850823e165
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/209110
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Per breaking change #45451 we are removing support for dart-ext:
style native extensions from the Dart VM.
This CL removes the associated VM code, tests and samples. It also ports
a single test which used dart-ext: import to use FFI instead.
TEST=ci
Bug: https://github.com/dart-lang/sdk/issues/45451
Change-Id: Iae984bce32baf29a950b5de1323939006a217b94
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/212050
Commit-Queue: Slava Egorov <vegorov@google.com>
Reviewed-by: Daco Harkes <dacoharkes@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
This allows local variables and other expressions, as long as the
static type is a generic function type, to be explicitly type
instantiated.
* Expressions with a non-generic function type cannot be type
instantiated.
* Expressions with a type of `Function` cannot be type instantiated.
* Expressions with other non-function types cannot be type instantiated.
This results in doubling-up of errors in a few situations. I think these
are generally rare occurrences, and tricky to prevent double reporting,
so I've left them for now.
Bug: https://github.com/dart-lang/sdk/issues/46020,
Change-Id: Iad212fd95773f39f3202480b3fa71f6a28c7698f
https://github.com/dart-lang/language/issues/1812
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/211941
Commit-Queue: Samuel Rawlins <srawlins@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
It's a badly designed class, but this change makes it slightly better.
(We should consider moving it to package:collection and removing it from
the platform libraries. Eventually.)
The changes decouples the public `DoubleLinkedQueueEntry` class from
the actual queue implementation classes, avoiding the latter having
to share a generic `_Link<DoubleLinkedQueueEntry>` interface
which would force them to do otherwise unnecessary casts.
The public class should have been abstract, but isn't.
It's mainly used as the API of the entries exposed by DoubleLinkedQueue,
but it can also be used by itself to build double-linked lists that are
not part of a Queue, and the class can be extended.
If anyone does either, it should keep working, so it needs to be a concrete,
self-contained class with a generative constructor.
That class is moved to dart:_internal to avoid its private
implementation fields from interfering with the queue implementation classes,
which have similar fields, but can now have them at different types.
That's a hack, but it works.
The internal implementation of the DoubleLinkedQueue and its entries
are updated to better follow current programming idioms, and avoids
having fields on classes which don't need them.
Also fixes#27920
(`clear`ing a list now detaches each entry from the list so later `.contains`
won't give the wrong answer).
And moves queue tests from tests/corelib to tests/lib/collection,
since Queue isn't exposed by `dart:core`.
BUG= https://github.com/dart-lang/sdk/issues/27920
Change-Id: Ia3bb340a75886de160cc0e449947e8e7ee587061
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/211265
Commit-Queue: Lasse R.H. Nielsen <lrn@google.com>
Reviewed-by: Nate Bosch <nbosch@google.com>
E.g. if reporting a missing ";" after a SyntheticStringToken (e.g. a
inserted identifier) before this CL it would go to the next token and
say we expected the ";" after that, when really we expected it *before*
that token.
Change-Id: I2c358e017edb2f661e307eba03dddaee889086d9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/205799
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Commit-Queue: Jens Johansen <jensj@google.com>
The 'File' object created in the async file open method is leaked
if the operation is not completed when the isolate shuts down
with an unhandled exception.
This change adds a finalizable state for the 'File' object so that
the message deletion that happens when ports are closed could run
the callback to clean up the 'File' object.
TEST=new tests added
Change-Id: I64c18a7905261b0fc7bf9f220086791478232d0d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/211340
Reviewed-by: Alexander Aprelev <aam@google.com>
Commit-Queue: Siva Annamalai <asiva@google.com>
Previously, initializers of implicitly typed variables did not
contribute to the SSA tracking performed by flow analysis (see
https://github.com/dart-lang/language/issues/1785). This change fixes
the bug, however the fix is conditioned on the "constructor tearoffs"
language feature to avoid compatibility issues (we don't want someone
to publish a package taking advantage of the fix, without realizing
that it makes their package unusable on older SDKs).
TEST=standard trybots
Bug: https://github.com/dart-lang/language/issues/1785
Change-Id: I1143440c7a9795b059e8f4b84e3f4125cd80732c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/211306
Commit-Queue: Paul Berry <paulberry@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>
`int` variables can attain NaN values because web int arithmetic
implemented by JavaScript numbers (doubles) is not closed under many
operations. It is possible get NaN using only addition:
int a = 1, b = -1;
while (a + a != a) { a += a; b += b; }
int nan = a + b;
On the VM, a, b and nan are all zero.
On the web, a, b and nan are Infinity, -Infinity and NaN, respectively.
Since NaN can leak into int arithmetic, is it helpful if bounds checks
catch NaN indexes. NaN compares false in any comparison, so a test
of the form
if (index < 0 || index >= a.length) throw ioore(a, index);
fails to detect a NaN value of `index`.
This is fixed by negating the comparisons, and applying De Morgan's law:
if (!(index >= 0 && index < a.length)) throw ioore(a, index);
These changes have been applied to JSArray.[], JSArray.[]= and String.[]
For dart2js the change is a little more involved. Primitive indexing is
lowered to code with a HBoundsCheck check instruction. The code generated
for the instruction now uses, e.g. `!(i>=0)` instead of `i<0`.
This leads to a small code size regression.
There is no regression at -O4 since bounds checks are omitted at -O4.
At -O3 (where the regression is largest) the regression is
0.01% for cm
0.06% for flutter gallery -- array-heavy diff and layout
0.21% for Meteor -- array-heavy code
0.30% for Box2DOctane -- array-heavy code
I believe the regression can be largely alleviated by determining if
NaN is impossible at the index check, and if so, reverting to the smaller
code pattern. The analysis could be global, incorporating NaN into the
global abstract value domain, or a much simpler a local dataflow
analysis. Many indexes are loop driven and cannot reach infinity because
they are incremented by a small bump and eventually (even without a loop
guard) the index would stop growing when the increment falls below the
rounding error in O(2^53) iterations.
Change-Id: I23ab1eb779f1d0c9c6655e13d69f65d453db9284
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/210321
Commit-Queue: Stephen Adams <sra@google.com>
Reviewed-by: Mayank Patke <fishythefish@google.com>
Change-Id: I3ea0be4032c3f9999239f2ae58514d21df9045d6
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/211281
Reviewed-by: Paul Berry <paulberry@google.com>
Commit-Queue: Erik Ernst <eernst@google.com>
Change-Id: I750345600d3b47de44c060511be35aea8744eca3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/211140
Commit-Queue: Erik Ernst <eernst@google.com>
Reviewed-by: Paul Berry <paulberry@google.com>
https://github.com/dart-lang/language/issues/1785 has a wide enough
impact that its fix will have to be bundled in with a language version
(i.e. future versions of Dart will have to reproduce the old buggy
behavior for code that's not opted in to the latest language version).
Therefore, we'll have to maintain tests of the behavior both before
and after the fix. This CL is the first step in that process, adding
tests that validate the current (buggy) behavior.
Bug: https://github.com/dart-lang/language/issues/1785
Change-Id: I78f17999ac1cbc096a312ef977db24654e06a263
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/210400
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Commit-Queue: Paul Berry <paulberry@google.com>
This reverts commit b67f45f955.
Reason for revert: This seems to cause a crash on ARMv7 aot compiled code.
Original change's description:
> [VM/Runtime] Fix 'File' object leak in async file open operation
>
> The 'File' object created in the async file open method is leaked
> if the operation is not completed when the isolate shuts down
> with an unhandled exception.
> This change adds a finalizable state for the 'File' object so that
> the message deletion that happens when ports are closed could run
> the callback to clean up the 'File' object.
>
> TEST=new tests added
>
> Change-Id: I4a3cb28370d27306c795c1914aeb5c18a1d85e2b
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/210761
> Reviewed-by: Alexander Aprelev <aam@google.com>
> Commit-Queue: Siva Annamalai <asiva@google.com>
TBR=aam@google.com,rmacnak@google.com,asiva@google.com
Change-Id: Ie91aadd318ef19a0bb4d7f769c9e876e76d719d8
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/211021
Reviewed-by: William Hesse <whesse@google.com>
Commit-Queue: William Hesse <whesse@google.com>
* This message should only be reported by the parser; the
error raised in the analyzer was strictly duplicate.
* This message theoretically used to mention "async*" or
"sync*" depending on the modifier that the function in
question listed. However, listing one modifier or the
other is a red herring, and may confuse the user; any
function declared with one or the other is a "generator",
and the error applies equally to a "generator" using one
or the other modifier.
Bug: https://github.com/dart-lang/sdk/issues/43665
Change-Id: I6ef1f5c055473170e7563222f6f0a6c56a4ad5f5
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/210801
Commit-Queue: Samuel Rawlins <srawlins@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
The 'File' object created in the async file open method is leaked
if the operation is not completed when the isolate shuts down
with an unhandled exception.
This change adds a finalizable state for the 'File' object so that
the message deletion that happens when ports are closed could run
the callback to clean up the 'File' object.
TEST=new tests added
Change-Id: I4a3cb28370d27306c795c1914aeb5c18a1d85e2b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/210761
Reviewed-by: Alexander Aprelev <aam@google.com>
Commit-Queue: Siva Annamalai <asiva@google.com>
On one hand this is less precise, OTOH this tells which feature and
the language version it requires.
Change-Id: I1d24a2d7cf2c7b7ca305d5bfc9f094fce0734bc4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/210644
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Reviewed-by: Samuel Rawlins <srawlins@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>
Previously, when encountering identifiers in metadata on a class's
type parameter, the analyzer would resolve them using the type
parameter scope, but then fall back on using implicit `this`. The CFE
would resolve them using the class body scope. In both cases, the end
result was that the annotation could refer to static class members.
This change brings the behavior of both the analyzer and the CFE in
line with the spec, by preventing the use of implicit `this` in these
annotations, and resolving them in the type parameter scope.
This is not expected to break any code in practice, because
annotations on type parameters are rare, as are annotations referring
to static class members, and the overlap between these two should be
negligibly small.
Fixes https://github.com/dart-lang/language/issues/1790.
Bug: https://github.com/dart-lang/language/issues/1790
Change-Id: Ibe5a421e04a53d29074a8b1509e1390658ed72e5
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/210040
Commit-Queue: Paul Berry <paulberry@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
This is a reland of 824bec596f
Original change's description:
> [vm] Hide internal implementation List types and expose them as List
>
> When taking a type of an instance with x.runtimeType we can map
> internal classes _List, _ImmutableList and _GrowableList to a
> user-visible List class. This is similar to what we do for
> implementation classes of int, String and Type.
> After that, result of x.runtimeType for built-in lists would be
> compatible with List<T> type literals.
>
> Also, both intrinsic and native implementations of _haveSameRuntimeType
> are updated to agree with new semantic of runtimeType.
>
> TEST=co19/LanguageFeatures/Constructor-tear-offs/type_literal_A01_t01
> TEST=runtime/tests/vm/dart/have_same_runtime_type_test
>
> Fixes https://github.com/dart-lang/sdk/issues/46893
> Issue https://github.com/dart-lang/sdk/issues/46231
>
> Change-Id: Ie24a9f527f66a06118427b7a09e49c03dff93d8e
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/210066
> Commit-Queue: Alexander Markov <alexmarkov@google.com>
> Reviewed-by: Tess Strickland <sstrickl@google.com>
TEST=co19/LanguageFeatures/Constructor-tear-offs/type_literal_A01_t01
TEST=runtime/tests/vm/dart/have_same_runtime_type_test
TEST=lib/mirrors/regress_b196606044_test
Fixes https://github.com/dart-lang/sdk/issues/46893
Issue https://github.com/dart-lang/sdk/issues/46231
Change-Id: I79b587540338808bd73a6554f00a5eed042f4c26
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/210201
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Tess Strickland <sstrickl@google.com>
[co19_2] LibTests/typed_data tests skipped for dart2js
Change-Id: I2e8a93f7991b36367b84678bbfebda36babaf96f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/209915
Reviewed-by: Erik Ernst <eernst@google.com>
Reviewed-by: Alexander Thomas <athom@google.com>
Add missing checks for FFI types disallowed in isolate messages.
Align error messages with the other serializer and test expectations.
TEST=ci
Change-Id: I3813dd8f26e5122524bdf41f9ce6e0785fdd260b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/209840
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
language/covariant/type_parameter_test.dart performed a tearoff which
should incur a run-time error (because the dynamic type of the
tearoff is not a subtype of the static type, so it would be a
soundness violation to pass that value on to the next step of
evaluation).
Change-Id: Ia4ec813606e711cab0bdcc68d24bbac3c9a2d8c2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/209910
Reviewed-by: Dmitry Stefantsov <dmitryas@google.com>
Commit-Queue: Erik Ernst <eernst@google.com>
This CL changes the test
language/generic_methods/explicit_instantiated_tearoff_test.dart
such that it no longer expects a generic instantiation of a local
function tearoff to be notEqual to another function object which is
the same local function, same enclosing invocation, same type
arguments.
The rationale is that we should not preclude an optimization whereby
these function objects are canonicalized (at run time, or if they
can be lifted to the top level even possibly at compile time).
Change-Id: I5845a19ce9ccf931c4d3abe4ab619f3ed2a2fbc4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/209860
Reviewed-by: Lasse R.H. Nielsen <lrn@google.com>
Commit-Queue: Erik Ernst <eernst@google.com>
This should handle all cases of constructor reference w/ explicit type
args; there aren't too many cases:
* named and unnamed constructors
* referencing class and referencing type alias
* prefixed class names and not-prefixed
* null-aware access (weird)
* bound on type parameter of class, and on type parameter of alias
error cases:
* cascade
* wrong number of type arguments
Bug: https://github.com/dart-lang/sdk/issues/46020
Change-Id: If257eb561a9ad854709b6e9a7d81faa9d084d6ee
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/209622
Commit-Queue: Samuel Rawlins <srawlins@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
The instantiation at runtime implies non-constant type expressions
but canonicalization is unspecified so backends should be allowed
to optimize by canonicalizing types.
Change-Id: I2f1cab6ac68a1ce156b15af0b99e02d03b7b3dca
Issue: https://github.com/dart-lang/sdk/issues/46837
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/209663
Commit-Queue: Nicholas Shahan <nshahan@google.com>
Reviewed-by: Erik Ernst <eernst@google.com>
The transitive copy algorithm was missing support for [WeakProperty]s,
thereby ensuring that we only copy the values if the keys are reachable.
Furthermore we might need to re-hash [Expando]s - since the copied
objects start with no identity hash codes.
The CL also makes us avoid calling to Dart for each [Expando]
separately and instead use a list - just as we do in the re-hashing of
maps/sets.
We also move the C++ code to invoke rehashing logic into
DartLibraryCalls::*.
Issue https://github.com/dart-lang/sdk/issues/36097
TEST=vm/dart{,_2}/isolates/fast_object_copy{,2}_test
Change-Id: I836745feef8a6d7573faa94e29a19c1eca0c39f2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/209106
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Previously the synthetic field that holds the FfiNative
function pointer was injected into the current library.
This change makes sure we instead add the field to the
relevant parent - Class or Library.
TEST=Added regression test for name collision.
Bug: https://github.com/dart-lang/sdk/issues/43889
Change-Id: Ifbf2d70de00e4748c179fe7d626c495675c2b338
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/208502
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Clement Skau <cskau@google.com>
We might get different flags on lhs and rhs of a subtype check as
lhs might come from a tear-off which has generic-covariant-impl type
parameters and rhs is a standalone function type.
TEST=language/regress/regress46816_test
Fixes https://github.com/dart-lang/sdk/issues/46816
Change-Id: Ic0f1b4a9fdf0f4c9ae65c8c372d12c1e51ad8050
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/209265
Reviewed-by: Tess Strickland <sstrickl@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
This CL restores the equality related tests in
tests/language/closure/identity_equality_tearoff_test.dart that we had
in https://dart-review.googlesource.com/c/sdk/+/202243, but removed
in order to finalize language team discussions about equality of
function objects, based on language issue #1712.
Note that these additional test cases do not include any cases involving
tearoffs of extension methods, they will be dealt with separately.
Change-Id: I84daaf91229bd0d0f4c64446bb71cb87f32eedfc
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/205081
Commit-Queue: Erik Ernst <eernst@google.com>
Reviewed-by: Lasse R.H. Nielsen <lrn@google.com>
Said test expects a raw type literal (e.g., `Direct`) to evaluate to an
instantiation where the type argument is `Object?` (`Direct<Object?>`),
but the type argument is actually chosen by instantiation to bound,
so the resulting type argument is `dynamic` (`Direct<dynamic>`). This
CL adjusts the test to expect `dynamic`.
Bug: https://github.com/dart-lang/sdk/issues/46811
Change-Id: I06af0bf87ccb5e980e88416085921948dd5234d1
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/209081
Reviewed-by: Lasse R.H. Nielsen <lrn@google.com>
Commit-Queue: Erik Ernst <eernst@google.com>
These annotations have all been replaced with @pragma('dart2js:xxx')
versions:
@ForceInline, @NoInline, @NoThrows, @NoSideEffects, @AssumeDynamic.
Change-Id: Ia4730670c6864ccbe0fa4120108c3c16ab887c23
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/208863
Reviewed-by: Sigmund Cherem <sigmund@google.com>
Commit-Queue: Stephen Adams <sra@google.com>