Knowledgebase Programming: Crashpad

Crashpad is a library for capturing, storing and transmitting postmortem crash reports from a client to an upstream collection server. Crashpad aims to make it possible for clients to capture process state at the time of crash with the best possible fidelity and coverage, with the minimum of fuss.

Crashpad also provides a facility for clients to capture dumps of process state on-demand for diagnostic purposes.

Crashpad additionally provides minimal facilities for clients to adorn their crashes with application-specific metadata in the form of per-process key/value pairs. More sophisticated clients are able to adorn crash reports further through extensibility points that allow the embedder to augment the crash report with application-specific metadata.

More information can be found under Crashpad Overview Design.

Supported Platforms

Currently Crashpad supports Windows and Mac OS only. On Windows, the supported compiler is MS Visual Studio. MinGW is not supported.

swift Infrastructure

Crash Handler

Crashpad is automatically linked and activated with a release build of swift. A standalone executable called swift_crashpad_handler is monitoring each swift executable. swift_crashpad_handler will collect process information including a full stack trace, in case of a abnormal abort. The collected information is automatically written into a minidump file and uploaded to https://swift-project.sp.backtrace.io

swift Breakpad Server

swift Breakpad Server is our fork of "Simple Breakpad Server". This fork is currently hosted at https://github.com/emiro85/simple-breakpad-server. The implementation is based on nodejs. It accepts minidump crashreports and symbols files needed to create a readable stack trace. Symbol files are automatically uploaded from a Jenkins Release build.

Produce Stacktrace Manually

In case a crash dump was uploaded without its corresponding symbol files (e.g. from a non-release Jenkins job), the stack trace can also created locally. This requires the following:

• Symbol files: Either download them from the Jenkins job (be careful since only the latest artifacts are kept. As soon as the job runs again, the artifacts are lost). Extract it.
• Download executable ''minidump_stackwalk''
  • Windows: Link TBD
  • Mac OS: Link TBD
• Download the dump file from Breakpad Server if you don't have it locally already

Run the command in a terminal:

minidump_stackwalk \<path to dump
file\> \<path to symbol files\> \> stacktrace.txt