Jens Johansen
0c2d7decd7
The analyzer makes a copy of `lineStarts` without the last element,
and copying it in to a `Uint16List` or an `Uint32List` depending on
what's needed (to avoid using more ram than necessary).
Because the (actual) scanner (`AbstractScanner`) does the same trick
with `Uint16List`/`Uint32List` the linestarts output from the scanner,
while a `List<int>`, is actually a `LineStarts` class, and copying that
into a `Uint16List` (or `Uint32List`) goes into
`_TypedIntListMixin._SlowSetRange` which as the name suggests is slower
than it has to be.
This CL puts the copying into the `LineStarts` class where it actually
has a `Uint16List`/`Uint32List` already, and doing the copy from that
instead avoids the slowdown.
Numbers from `perf stat`:
Before:
```
39,552,191,101 instructions:u
39,552,058,132 instructions:u
39,552,065,649 instructions:u
```
After:
```
39,419,426,977 instructions:u
39,419,429,914 instructions:u
39,419,441,613 instructions:u
```
Saving: about 132 million instructions.
Change-Id: Ibf6c7f6cc9324a54d2bd99c37058103af106164c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/508580
Reviewed-by: Johnni Winther <johnniwinther@google.com>
This package provides a library that performs static analysis of Dart code. It is useful for tool integration and embedding.
End-users should use the dart analyze command-line tool to analyze their Dart code.
Integrators that want to add Dart support to their editor should use the Dart Analysis Server. The Analysis Server API Specification is available. If you are adding Dart support to an editor or IDE, please let us know by emailing our list.
Configuring the analyzer
Both dart analyze and Dart Analysis Server can be configured with an
analysis_options.yaml file (using an .analysis_options file is deprecated).
This YAML file can control which files and paths are analyzed,
which lints are applied, and more.
If you are embedding the analyzer library in your project, you are responsible for finding the analysis options file, parsing it, and configuring the analyzer.
The analysis options file should live at the root of your project (for example,
next to your pubspec.yaml). Different embedders of analyzer, such as
dart analyze or Dart Analysis Server, may choose to find the file in various
different ways. Consult their documentation to learn more.
Here is an example file that instructs the analyzer to ignore two files:
analyzer:
exclude:
- test/_data/p4/lib/lib1.dart
- test/_data/p5/p5.dart
- test/_data/bad*.dart
- test/_brokendata/**
Note that you can use globs, as defined by the glob package.
Here is an example file that enables two lint rules:
linter:
rules:
- camel_case_types
- empty_constructor_bodies
Check out all the available Dart lint rules.
You can combine the analyzer section and the linter section into a single
configuration. Here is an example:
analyzer:
exclude:
- test/_data/p4/lib/lib1.dart
linter:
rules:
- camel_case_types
For more information, see the docs for customizing static analysis.
Who uses this library?
Many tools embed this library, such as:
- dart format - a formatter for Dart code
- dart doc - a documentation generator for Dart code
- Dart Analysis Server - a stateful server that supports IDEs and editors
Support
Post issues and feature requests at https://github.com/dart-lang/sdk/issues. These will be triaged according to the analyzer triage priorities.
Questions and discussions are welcome at the Dart Analyzer Discussion Group.
Background
The APIs in this package were originally machine generated by a translator and were based on an earlier Java implementation. Several of the API's still look like their Java predecessors rather than clean Dart APIs.
In addition, there is currently no clean distinction between public and internal APIs. We plan to address this issue but doing so will, unfortunately, require a large number of breaking changes. We will try to minimize the pain this causes for our clients, but some pain is inevitable.
License
See the LICENSE file.