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native_stack_traces

0.4.5

Utilities for working with non-symbolic stack traces.

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native_stack_traces

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.

@pragma('vm:prefer-inline')
bar() => throw Null;

@pragma('vm:never-inline')
foo() => bar();

main() => foo();

Now we run the following commands:

# 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.

Changelog

0.4.5

  • Handle stack traces larger than 100 entries.

0.4.5-dev

  • Require Dart >= 2.14

0.4.4

  • Added handling of dynamic tables for testing.

0.4.3

  • Exported some more of the ELF utilities for use in Dart tests.

0.4.2

  • When decoding a stack trace, frames corresponding to the functions with DW_AT_artificial DWARF attribute are now omitted from the symbolized stack traces. This is needed because Dart VM no longer omits invisible functions from binary stack traces in certain cases.

0.4.1

  • Exported some ELF utilities in lib/elf.dart for use in Dart tests.

0.4.0

  • Stable null safe version of package.

0.4.0-nullsafety

  • Unstable null safe version of package.

0.3.8

  • Support columns when present in line number programs.

0.3.7

  • Added buildId accessor for retrieving GNU build IDs from DWARF files that include them.

0.3.6

  • Adjusts RegExp for stack trace header line to be more flexible in what it permits to allow additional information to be added in the Dart VM.

0.3.5

  • Use virtual addresses in non-symbolic stack frames as a fallback if we cannot retrieve an appropriate offset from the instructions section otherwise.

0.3.4

  • Decoded Dart calls are now never considered internal, only VM stub calls. This is due to a concurrent change in the Dart VM that no longer prints non-symbolic frames for functions considered invisible, which matches the symbolic frame printer and removes the need for the decoder to guess which frames should be hidden.

    This package still works on earlier versions of Dart, so the dependencies have not changed. However, it may print more frame information than expected when decoding stack frames from a Dart VM that does not include this change to non-symbolic stack printing.

0.3.3

  • No externally visible changes.

0.3.2

  • The find command can now look up addresses given as offsets from static symbols, not just hexadecimal virtual or absolute addresses.
  • Integer inputs (addresses or offsets) without an '0x' prefix or hexadecimal digits will now be parsed as decimal unless the -x/--force_hexadecimal flag is used.

0.3.1

  • Uses dynamic symbol information embedded in stack frame lines when available.

0.3.0

  • Adds handling of virtual addresses within stub code payloads.

0.2.2

  • Finds instruction sections by the dynamic symbols the Dart VM creates instead of assuming there are two text sections.

0.2.1

  • Added static method Dwarf.fromBuffer.

0.2.0

  • API and documentation cleanups

0.1.0

  • Initial release

Installing

export PUB_HOSTED_URL=https://pub.mirror.p-hatan.ir
flutter pub add 'native_stack_traces:0.4.5'
pubspec.yaml
name: native_stack_traces
description: Utilities for working with non-symbolic stack traces.
version: 0.4.5

homepage: https://github.com/dart-lang/sdk/tree/master/pkg/native_stack_traces

environment:
  sdk: '>=2.14.0 <3.0.0'

executables:
  decode:

dependencies:
  args: ^2.0.0
  path: ^1.8.0

dev_dependencies:
  lints: ^1.0.0

Version history

VersionPublishedArchiveSHA-256
0.1.0Cached · Upstream SHA-256 matchedDownload19ce271b…5e7d4b
0.2.0Cached · Upstream SHA-256 matchedDownload2a936cd6…6976b8
0.2.2Cached · Upstream SHA-256 matchedDownload72f7d26d…f026b1
0.3.0Cached · Upstream SHA-256 matchedDownloade86d82e3…4d64b3
0.3.1Cached · Upstream SHA-256 matchedDownloadcb8587d9…eab909
0.3.2Cached · Upstream SHA-256 matchedDownloaddc69b781…935024
0.3.3Cached · Upstream SHA-256 matchedDownload68475ec4…2d6fb1
0.3.6Cached · Upstream SHA-256 matchedDownloade53de201…302093
0.3.7Cached · Upstream SHA-256 matchedDownload094372b4…78438a
0.4.0Cached · Upstream SHA-256 matchedDownloadaa90ca18…034e5f
0.4.3Cached · Upstream SHA-256 matchedDownload6773cb61…448a0b
0.4.5Cached · Upstream SHA-256 matchedDownload8a5c9214…7c78bd
0.4.6Cached · Upstream SHA-256 matchedDownload4af5cf89…c6a066
0.5.0Cached · Upstream SHA-256 matchedDownloade1917b08…9dceab
0.5.2Cached · Upstream SHA-256 matchedDownload42393c08…fcc421
0.5.4Cached · Upstream SHA-256 matchedDownload56eb633e…0af899
0.5.5Cached · Upstream SHA-256 matchedDownload5f1938ea…bcd104
0.5.6Cached · Upstream SHA-256 matchedDownloadc797830b…74013f
0.5.7Cached · Upstream SHA-256 matchedDownload64d2f4bc…34bfd3
0.6.0Cached · Upstream SHA-256 matchedDownload8ba566c1…ee470f
0.6.1Cached · Upstream SHA-256 matchedDownloadd34cf916…3d6a11
0.7.0Cached · Upstream SHA-256 matchedDownload2117de75…1b19d0

Dependencies

args "^2.0.0"

path "^1.8.0"