mirror of
https://github.com/dart-lang/sdk
synced 2024-09-21 08:42:07 +00:00
ba264a6474
Change-Id: I0897938add16b8c20b213ccb83b096a2b848d0ff Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/246321 Reviewed-by: Tess Strickland <sstrickl@google.com> Commit-Queue: Devon Carew <devoncarew@google.com>
67 lines
2.6 KiB
Markdown
67 lines
2.6 KiB
Markdown
[](https://pub.dev/packages/native_stack_traces)
|
|
[](https://pub.dev/packages/native_stack_traces/publisher)
|
|
|
|
This package provides libraries and a utility for decoding non-symbolic
|
|
stack traces generated by an AOT-compiled Dart application.
|
|
|
|
## Converting stack traces
|
|
|
|
In some modes of AOT compilation, information on mapping execution points to
|
|
source locations is no longer stored in the Dart image. Instead, this
|
|
information is translated to separately stored debugging information.
|
|
This debugging information can then be stripped from the application
|
|
before shipping.
|
|
|
|
However, there is a drawback. Stack traces generated by such an application no
|
|
longer includes file, function, and line number information (i.e., symbolic
|
|
stack traces). Instead, stack trace frames simply include program counter
|
|
information. Thus, to find the source information for these frames, we must use
|
|
the debugging information. This means either keeping the original unstripped
|
|
application, or saving the debugging information into a separate file.
|
|
|
|
Given this debugging information, the libraries in this package can turn
|
|
non-symbolic stack traces back into symbolic stack traces. In addition, this
|
|
package includes a command line tool `decode` whose output is the same as its
|
|
input except that non-symbolic stack traces are translated.
|
|
|
|
### Using `decode`
|
|
|
|
Take the following Dart code, which we put in `throws.dart`. The inlining
|
|
pragmas are here just to ensure that `bar` is inlined into `foo` and that `foo`
|
|
is _not_ inlined into `bar`, to illustrate how inlined code is handled in the
|
|
translated output.
|
|
|
|
```dart
|
|
@pragma('vm:prefer-inline')
|
|
bar() => throw Null;
|
|
|
|
@pragma('vm:never-inline')
|
|
foo() => bar();
|
|
|
|
main() => foo();
|
|
```
|
|
|
|
Now we run the following commands:
|
|
|
|
```bash
|
|
# Make sure that we have the native_stack_traces package.
|
|
$ dart pub global activate native_stack_traces
|
|
|
|
# We compile the example program, removing the source location information
|
|
# from the snapshot and saving the debugging information into throws.debug.
|
|
$ dart compile exe -S throws.debug throws.dart
|
|
|
|
# Run the program, saving the error output to throws.err.
|
|
$ ./throws.exe 2>throws.err
|
|
|
|
# Using the saved debugging information, we can translate the stack trace
|
|
# contained in throws.err to its symbolic form.
|
|
$ dart pub global run native_stack_traces:decode translate -d throws.debug -i throws.err
|
|
```
|
|
|
|
## Features and bugs
|
|
|
|
Please file feature requests and bugs at the [issue tracker][tracker].
|
|
|
|
[tracker]: https://github.com/dart-lang/sdk/issues
|