Breakpad

This is a fork of Google Breakpad, a multi-platform crash reporting system, which is used by Mendeley Desktop under Windows, Mac and Linux.

Mendeley's additions to breakpad include:

• A CMake-based build system for the crash capturing client library, debug symbol extraction and stacktrace output (minidump_stackwalk) tools.

• Support in minidump_stackwalk for fetching debug symbols from arbitrary sources by invoking a user-provided command instead of looking in a specific local filesystem directory. We use this to fetch debug symbols on-demand from an archive hosted in S3.

• A python script which fetches debug symbols from a symbol server with a given HTTP URL

• A simple multi-platform end-to-end test that builds a buggy app with the crash capturing library installed, extracts debug symbols from it, runs the test app and symbolizes the resulting crash dump.

• Compatibility with C++11

Building Breakpad

git clone https://github.com/Mendeley/breakpad.git
mkdir breakpad-build
cd breakpad-build
cmake ../breakpad/mendeley
make

Usage

The overall flow for capturing crashes and debugging them as follows:

1. Build the breakpad tools and libraries
2. Link the breakpad library with your application
3. Early in your app's startup code, create an instance of google_breakpad::ExceptionHandler. This is defined separately for each platform in client/<platform>/handler/exception_handler.h
4. When the app crashes, it will write a .dmp file to the directory specified when the ExceptionHandler object was created.
5. When building a release build of your app, run the dump_syms tool on the generated DLLs and binaries to produce .sym files which contain mappings from program locations to source locations.
6. Upload the .sym files to a location which is accessible via a HTTP URL. See this StackOverflow comment for details of the expected structure of the symbol server
7. When your app crashes on a user's system, get the .dmp file and use minidump_stackwalk to produce a stacktrace from the .dmp file.

You can also debug the .dmp files in Visual Studio on Windows.

Getting a stacktrace from a minidump

When you have a .dmp file captured by the breakpad library after an application crashes and have uploaded it to a location accessible via a HTTP URL, you can use the minidump_stackwalk tool to extract a stack trace from the minidump.

./minidump_stackwalk -m <path to .dmp file> -e '../breakpad/mendeley/fetch-symbols.py -s <URL of your symbol server>'