Paul Berry
d9ca760992
This CL adds the ability to create a list of "forwarding nodes" for a
source class. A forwarding node is a data structure that will later
be resolved to either an explicitly declared member in the class or a
superclass, or to a forwarding stub. The idea is that we will create
the forwarding nodes at the time of outline building, and later,
during type inference, we will resolve each forwarding node as it is
encountered.
The reason we need to defer resolution of the forwarding nodes until
inference is because we may need to use the results of type inference
to determine which member a given forwarding node resolves to. For
example:
num f() => 1;
class A {
final x = 1; // Inferred type: int
}
class B {
final x = f(); // Inferred type: num
}
abstract class C implements A, B {}
We cannot determine at the time of building the outline for C whether
it inherits its x from A or B, because we need the results of type
inference to determine which of the two x's has a more specific type.
Note that some refactoring of ClassHierarchy was necessary in order to
allow the front end to maintain member lists in the same order used
internally by ClassHierarchy. This will let us avoid unnecessary
redundant sorting of methods.
Change-Id: Iee754957e0ad3b16c4b60608e17a4a7b0006dfb4
Reviewed-on: https://dart-review.googlesource.com/7851
Commit-Queue: Paul Berry <paulberry@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@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 as a frontend for codegen and execution backends.
The kernel language has in-memory representations in Dart and C++, 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
- A frontend based on the analyzer
- Serialization of kernel code
Note: The APIs in this package are in an early state; developers should be careful about depending on this package.
Getting Kernel
Checkout the repository and run pub get:
git clone https://github.com/dart-lang/kernel
cd kernel
pub get
Command-Line Tool
Run tool/dartk.dart from the command-line to convert between .dart files
and the serialized binary and textual formats.
dartk expects the .dill extension for files in the binary format.
The textual format has no preferred extension right now.
Example commands:
dartk foo.dart # print text IR for foo.dart
dartk foo.dart -ofoo.dill # write binary IR for foo.dart to foo.dill
dartk foo.dill # print text IR for binary file foo.dill
Pass the --link or -l flag to link all transitive dependencies into one file:
dartk myapp.dart -ppackages -l -omyapp.dill # Bundle everything.
dartk myapp.dill # Print it back out in a (very, very long) textual format.
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.
Testing
If you plan to make changes to kernel, get a checkout of the Dartk SDK and run:
tool/regenerate_dill_files.dart --sdk <path to SDK checkout>
pub run test
Linking
Linking from binary files is not yet implemented. In order to compile a whole program, currently everything must be compiled from source at once.