Tess Strickland
2c0484c720
* Add an `targetOS` argument to `pkg/vm`'s `compileToKernel`,
that contains the target operating system's name.
* Add a new `--target-os` command line argument for all binaries
that use `compileToKernel` for clients to provide the target
operating system, if known.
* Add a new`"vm:platform:const"` annotation to certain field and
getters in the Platform class.
This annotation is used to annotate static getters and fields with
initializers where the getter body or field initializer must evaluate
to a constant value if the target operating system is known. This
annotation may be used outside the Platform class and in user code.
For example, this annotation can be used on a static `String` field
that is initialized with one value if `Platform.isWindows` is true
and to a different value if `Platform.isWindows` is false.
Note: If the const functions experimental flag is disabled, then
any annotated static methods can only contain a single expression
whose value is returned. If it is enabled, then the static method
is evaluated as if it is a const function with the special
handling of annotated static fields and getters above.
* Create a VM constant evaluator that evaluates uses of static getters
and fields marked with the above annotations when a target operating
system is provided.
* Use the new VM constant evaluator in the unreachable code elimination
transformer.
TEST=pkg/vm/test/transformations/platform_use_transformer
pkg/vm/test/transformations/unreachable_code_elimination
Change-Id: Ie381de70486a767fd7b1d515fd9e6bb58c6bf090
Bug: https://github.com/dart-lang/sdk/issues/31969
Cq-Include-Trybots: luci.dart.try:pkg-linux-release-try
CoreLibraryReviewExempt: Just adding vm-specific annotations.
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/274386
Commit-Queue: Tess Strickland <sstrickl@google.com>
Reviewed-by: Chloe Stefantsova <cstefantsova@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Dart Kernel
Dart Kernel is a small high-level language derived from Dart. It is designed for use as an intermediate format for whole-program analysis and transformations, and to be consumed by codegen and execution backends.
The kernel language has an in-memory representation in Dart and can be serialized as binary or text.
Both the kernel language and its implementations are unstable and are under development.
This package contains the Dart part of the implementation and contains:
- A transformable IR for the kernel language
- Serialization of kernel code
Note: The APIs in this package are in an early state; developers should be careful about depending on this package. In particular, there is no semver contract for release versions of this package. Please depend directly on individual versions.
See ast.dart for the in-memory IR, or binary.md for a description of the binary format. For now, the textual format is very ad-hoc and cannot be parsed back in.