Jens Johansen
d26558b7be
This CL allows for streaming big parts of the binary,
i.e. without using the AST nodes.
It is thus a stepping-stone in getting rid of the AST nodes in the VM.
Generally, all Expressions except "FunctionExpression",
and all Statements except "FunctionDeclaration" can be streamed.
There are currently not streamed because they create new functions,
which has a pointer to an AstNode (which we don't have when streaming).
Once we no longer need AstNodes at all these can be streamed as well.
This is, I think, mostly a matter of streaming the ScopeBuilder as well,
something that is not currently done.
The way the streaming is build, one has to stream an entire subtree.
That means, that if an expression (or statement), A, that is generally
streamable contains an expression or a statement, B, that is not streamable,
A cannot be streamed.
The way this is build is by marking AstNodes as streamable or not
("cannot_stream_" field). That way we know up front whether we can stream
a subtree or not.
The streaming is done via "kernel_binary_flowgraph".
In this file there are many obvious comments, e.g.
```
TokenPosition position = ReadPosition(); // read position.
```
This has been done in an attempt to add a comment to everything that
reads from the binary to make it stand out more.
All changes from kernel_to_il up to and including May 2nd 2017
should be included.
R=kmillikin@google.com
Review-Url: https://codereview.chromium.org/2854393002 .
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.