Kevin Millikin
65b19ffa3c
Translate assert statements in async functions. The translation of
the condition subexpression can produce a sequence of statements that
have been hoisted out of it. These need to be guarded so they are
executed only when asserts are enabled.
For this purpose, we introduce an AssertBlock. The semantics of the
assert block:
assert { s0; ...; sn; }
is the same as:
if (assertsEnabled) { s0; ...; sn; }
where assertsEnabled is a more primitive nullary expression that is
true iff. assertions are enabled. We chose not to encode this using a
construct like assertsEnabled because (1) we would have to support it
appearing as an arbitrary expression which we don't currently need
and (2) it requires deeper pattern matching to detect and skip the
guarded code when desired.
The translation is more complicated because if there is a message
subexpression in an assert, it is conditionally evaluated only if the
assert's condition is false.
Fixes https://github.com/dart-lang/sdk/issues/28498
Change-Id: I0912a57104ede3160533e49f65b6fb79b76f1500
Reviewed-on: https://dart-review.googlesource.com/46442
Commit-Queue: Kevin Millikin <kmillikin@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 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.