Dart's `throw` expression does not correspond exactly to JavaScript's `throw` statement. To implement Dart semantics, and to reduce code size, dart2js uses the functions `wrapException` and `throwExpression` from the dart2js runtime. As a result, these functions appear in the stack trace (one or both).
A consequence of this is that a fixed prefix of an error stack is less useful, as potentially interesting frames are forced out of the prefix by these 'noise' frames.
This change ensures only one of the helpers on the stack trace.
It is also possible to get rid of the helper frame by an annotation.
The annotation `@pragma('dart2js:stack-starts-at-throw')` causes the stack to be captured in the current JavaScript function rather than in a helper. The cost is more code at the call site, about 12 bytes per `throw` expression in minified code. The annotation can be placed on a method, class or library, and applies to all `throw` expression in the scope of the annotated element.
This change uses the annotation to remove noise frames from type errors and some other errors in the runtime.
Change-Id: If15184a5963fb054199177bb4526b32f25e53fe9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/406684
Reviewed-by: Mayank Patke <fishythefish@google.com>
Reviewed-by: Nate Biggs <natebiggs@google.com>
Collects files from `package:async_helper` and `tests/language`
that are generally useful, so that all test-related helpers are
in `package:expect`.
Moves the two libraries from `package:async_helper` into `package:expect`,
and the `tests/language/static_type_helper.dart` file too.
Deprecates `async_minitest.dart`, to follow `minitest.dart`,
expecting the Flutter use of it to have been fixed to not break
on deprecation (I believe Flutter no longer breaks builds on deprecations at all).
Patch 1 is the actual change.
Patch 2+4+8 is changing all existing references to the files.
Patch 6 ignores deprecation in files still using `async_minitest.dart`.
3+5+7+9 are updating this text to make the numbers match.
Then it's just test-expectations and small tweaks from there.
Change-Id: I1b665135b5fef9b9a0c3b340ffe9daf874d0174c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/373120
Reviewed-by: Nate Bosch <nbosch@google.com>
Reviewed-by: Devon Carew <devoncarew@google.com>
Commit-Queue: Lasse Nielsen <lrn@google.com>
- Remove unsound platform .dill files from the packaged SDK.
- Throw and error referencing the sound null safety requirements of
Dart 3 when compiling with `--no-sound-null-safety` and an unsound
platform .dill file is not found.
Change-Id: I703a446e3e92c76a6b48168577fc0161eea83854
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/289280
Commit-Queue: Nate Biggs <natebiggs@google.com>
Reviewed-by: Sigmund Cherem <sigmund@google.com>
This prepares dart2js to default to sound null safety in Dart 3.0.
The compiler no longer infers the default mode based on the input
program, instead uses sound null safety unless
'--no-sound-null-safety' is specified.
On a separate change, we expect to remove the option of disabling
null safety.
Note: this change should also be reflected in the CHANGELOG, but
we've currently not included it to redeuce merge conflicts, as we plan
to land multiple 3.0-alpha changes in a short window of time
Change-Id: Id87498cc5976548ec89d1f36c60674b72406950a
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/270860
Reviewed-by: Nate Biggs <natebiggs@google.com>
Commit-Queue: Siva Annamalai <asiva@google.com>
Reviewed-by: Mayank Patke <fishythefish@google.com>
This reverts commit 69f32d6ad7.
Reason for revert: We seem to have a number of tests failing with timeouts in CBUILD after this change, please see logs at
https://dart-in-g3-qa-prod.corp.google.com/dg3/Home#/cbuild/find/69f32d6ad7e724e3148cb2eb6601e63165e76ad3
Original change's description:
> Refactor `_Future`.
>
> This is a major rewrite of the `_Future` class,
> which is the default implementation of the `Future` interface.
>
> The main goal was to reduce the number of expensive type checks
> in the internal passing around of data.
> Expensive type checks are things like
> * `is _Future<T>` (more expensive than just `is _Future`, the latter
> can be a single class-ID check.
> * Covariant generic parameter checks (using `T` covariantly in a
> parameter forces a run-time type check).
>
> Also removed some plain unnecessary casts and turned some
> implicit casts from `dynamic` into `unsafeCast`s.
>
> This seems to be an success, at least on very primitive benchmarks, according to Golem:
> FutureCatchErrorTest 41.22% (1.9 noise)
> FutureValueTest 46.51% (2.8 noise)
> EmptyFutureTest 59.15% (3.1 noise)
> FutureWhenCompleteTest 51.10% (3.2 noise)
>
> A secondary goal was to clean up a very old and messy class,
> and make it clearer for other `dart:async` how to interact
> with the future.
>
> The change has a memory cost: The `_FutureListener<S,T>` class,
> which represents a `then`, `catchError` or `whenComplete`
> call on a `_Future`, now contains a reference to its source future,
> the one which provides the inputs to the callbacks,
> as well as the result future returned by the call.
> That's one extra memory slot per listener.
>
> In return, the `_FutureListener` now does not need to
> get its source future as an argument, which needs a covariant
> generic type check, and the methods of `_Future` can be written
> in a way which ignores the type parameters of both `_Future`
> and `_FutureListener`, which reduces complex type checks
> significantly.
>
> In general, typed code is in `_FutureListener`, which knows both
> the source and target types of the listener callbacks, and which
> contains the futures already at that type, so no extra type checking
> is needed.
> The `_Future` class is mostly untyped, except for its "public"
> API, called by other classes, which checks inputs,
> and code interacting with non-native futures.
> Invariants ensure that only correctly typed values
> are stored in the untyped shared `_resultOrListeners` field
> on `_Future`, as determined by its `_state` integer.
> (This was already partially true, and has simply been made
> more consistent.)
>
> Further, we now throw an error in a situation that was previously
> unhandled: When a `_Future` is completed with *itself*.
> That would ensure that the future would never complete
> (it waits for itself to complete before it can complete),
> and may potentially have caused weird loops in the representation.
> In practice, it probably never happens. Now it makes the error
> fail with an error.
> Currently a private `_FutureCyclicDependencyError` which presents
> as an `UnsupportedError`.
> That avoids code like
> ```dart
> import "dart:async";
> void main() {
> var c = Completer();
> c.complete(c.future); // bad.
> print("well!");
> var d = Completer();
> d.complete(c.future);
> print("shucks!");
> }
> ```
> from hanging the runtime by busily searching for the end of a cycle.
>
> See https://github.com/dart-lang/sdk/issues/48225
> Fixes#48225
>
> TEST= refactoring covered by existing tests, few new tests.
>
> Change-Id: Id9fc5af5fe011deb0af3e1e8a4ea3a91799f9da4
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/244241
> Reviewed-by: Martin Kustermann <kustermann@google.com>
> Commit-Queue: Lasse Nielsen <lrn@google.com>
TBR=lrn@google.com,kustermann@google.com,sra@google.com,sigmund@google.com,nshahan@google.com
Change-Id: I455be5a04b4c346df26d4ded0fa7388baccb0f8c
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/247762
Reviewed-by: Siva Annamalai <asiva@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>
Commit-Queue: Alexander Aprelev <aam@google.com>
This is a major rewrite of the `_Future` class,
which is the default implementation of the `Future` interface.
The main goal was to reduce the number of expensive type checks
in the internal passing around of data.
Expensive type checks are things like
* `is _Future<T>` (more expensive than just `is _Future`, the latter
can be a single class-ID check.
* Covariant generic parameter checks (using `T` covariantly in a
parameter forces a run-time type check).
Also removed some plain unnecessary casts and turned some
implicit casts from `dynamic` into `unsafeCast`s.
This seems to be an success, at least on very primitive benchmarks, according to Golem:
FutureCatchErrorTest 41.22% (1.9 noise)
FutureValueTest 46.51% (2.8 noise)
EmptyFutureTest 59.15% (3.1 noise)
FutureWhenCompleteTest 51.10% (3.2 noise)
A secondary goal was to clean up a very old and messy class,
and make it clearer for other `dart:async` how to interact
with the future.
The change has a memory cost: The `_FutureListener<S,T>` class,
which represents a `then`, `catchError` or `whenComplete`
call on a `_Future`, now contains a reference to its source future,
the one which provides the inputs to the callbacks,
as well as the result future returned by the call.
That's one extra memory slot per listener.
In return, the `_FutureListener` now does not need to
get its source future as an argument, which needs a covariant
generic type check, and the methods of `_Future` can be written
in a way which ignores the type parameters of both `_Future`
and `_FutureListener`, which reduces complex type checks
significantly.
In general, typed code is in `_FutureListener`, which knows both
the source and target types of the listener callbacks, and which
contains the futures already at that type, so no extra type checking
is needed.
The `_Future` class is mostly untyped, except for its "public"
API, called by other classes, which checks inputs,
and code interacting with non-native futures.
Invariants ensure that only correctly typed values
are stored in the untyped shared `_resultOrListeners` field
on `_Future`, as determined by its `_state` integer.
(This was already partially true, and has simply been made
more consistent.)
Further, we now throw an error in a situation that was previously
unhandled: When a `_Future` is completed with *itself*.
That would ensure that the future would never complete
(it waits for itself to complete before it can complete),
and may potentially have caused weird loops in the representation.
In practice, it probably never happens. Now it makes the error
fail with an error.
Currently a private `_FutureCyclicDependencyError` which presents
as an `UnsupportedError`.
That avoids code like
```dart
import "dart:async";
void main() {
var c = Completer();
c.complete(c.future); // bad.
print("well!");
var d = Completer();
d.complete(c.future);
print("shucks!");
}
```
from hanging the runtime by busily searching for the end of a cycle.
See https://github.com/dart-lang/sdk/issues/48225Fixes#48225
TEST= refactoring covered by existing tests, few new tests.
Change-Id: Id9fc5af5fe011deb0af3e1e8a4ea3a91799f9da4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/244241
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Lasse Nielsen <lrn@google.com>
Remove messages referring to expired `non-nullable` experiment.
Remove occurrences of --enable-experiment with expired experiments.
TEST=Flags were expired. If existing tests still run, it's a success.
Change-Id: Id66d78eb0a3191ec5e31375faf0effd9ea7b768f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/219789
Auto-Submit: Lasse R.H. Nielsen <lrn@google.com>
Commit-Queue: Lasse R.H. Nielsen <lrn@google.com>
Reviewed-by: Alexander Thomas <athom@google.com>
Mayank Patke