Jens Johansen
dfef2338eb
The VM creates context objects even though it's only applicable in a non-taken branch. This CL moves such a branch into its own function and thus avoids the context object creation when loading a dill file eagerly. This CL further more reduces the number of context creations by not lazy loading basically non-existing function node bodies (e.g. the body of a FunctionNode in the outline). The change has the following effect when loading platform/outline 100 times after 2 seconds warmup (statistics on 5 runs): Outline, lazy loading disabled: -12.8133% +/- 2.26214% Outline, lazy loading enabled: -40.9197% +/- 1.50042% Platform, lazy loading disabled: No difference proven at 95.0% confidence Platform, lazy loading enabled: -44.3347% +/- 0.613235% Bug: Change-Id: I9634e0a81f43efeb4e2524edb765d36072074f1e Reviewed-on: https://dart-review.googlesource.com/18220 Reviewed-by: Peter von der Ahé <ahe@google.com> Commit-Queue: Jens Johansen <jensj@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.