Add `@pragma('dart2js:allow-cse')` and `@pragma('dart2js:allow-dce')`.
These annotations allow the compiler to do common subexpression
elimination and dead code elimination on calls to getters and methods.
Change-Id: Ie4091466e4782a4d28a7f9bfbfdb60a5de45a384
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/426360
Reviewed-by: Nate Biggs <natebiggs@google.com>
Commit-Queue: Stephen Adams <sra@google.com>
We haven't worked on this feature in a couple years, but we have
some documentation that may be useful to existing developers.
This was initially written by Joshua a long time ago, but we never added
it to our repo.
Change-Id: Icf0dbc40978ed8529c2918304b712d0f9d84811d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/408342
Commit-Queue: Sigmund Cherem <sigmund@google.com>
Reviewed-by: Nate Biggs <natebiggs@google.com>
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>
Calls to methods annotated with `@pragma('dart2js:resource-identifier')` are tracked, with their primitive constant arguments, through to the `.js` file which contains the call.
- JavaScript annotations are attached to the JavaScript AST node for
the call.
- At the time of `.js` file printing, the JavaScript annotations are
collected and attributed to the file. This allows the construction
of a map from `.js` files to the 'resource identifiers' contained in
the file.
- Alongside the `main.js` file the resource identifiers are emitted in
a file called `main.js.resources.json`. This is controlled by the
`--write-resources` command line option.
- Serialization of JavaScript ASTs now serializes the attached
JavaScript annotations.
- The internal method used to implement deferred library loading is
annotated, to allow analysis of which deferred library parts load
other libraries.
pkg/js_ast was tweaked to make the pkg/js_ast was tweaked to make the
- pkg/js_ast was tweaked to make propagating the JavaScript annotations through the async transforms easier.
TODO:
- Annotate const constructors
- Add golden-style tests
Change-Id: Iea77550e22ee98f81dca61dfd713c09f734583d2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/284492
Reviewed-by: Nate Biggs <natebiggs@google.com>
Commit-Queue: Stephen Adams <sra@google.com>
Add annotations
@pragma('dart2js:load-priority:normal')
@pragma('dart2js:load-priority:high')
The test shows that these annotations are scoped.
This CL is just plumbing the annotation through as an argument to the runtime call to the code that implements `loadLibrary()`. Actual prioritization is not yet implemented.
Change-Id: Iff1404baf34192139dab95e2dbb01c2d4e8dae45
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/270283
Reviewed-by: Sigmund Cherem <sigmund@google.com>
Commit-Queue: Stephen Adams <sra@google.com>
Stephen Adams