Breakpad for Cygwin/MinGW

google-breakpad with support added for PE/COFF executables with DWARF debugging information, as used by Cygwin/MinGW

Compiling

Preparation

Since git-svn ignores svn externals, this repository is missing the gyp and gtest dependencies. Run the fetch-svn-externals script to add them.

./fetch-svn-externals

Run autoreconf to generate ./configure

autoreconf -fvi

Compiling

See README

./configure && make

will produce dump_syms, minidump_dump, minidump_stackwalk, libbreakpad.a and for MinGW libcrash_generation_client.a, libcrash_generation_server.a, crash_generation_app.exe

Using

See http://code.google.com/p/google-breakpad/wiki/GettingStartedWithBreakpad

Producing and installing symbols

dump_syms crash_generation_app.exe >crash_generation_app.sym
FILE=`head -1 crash_generation_app.sym | cut -f5 -d' '`
BUILDID=`head -1 crash_generation_app.sym | cut -f4 -d' '`
SYMBOLPATH=/symbols/${FILE}/${BUILDID}/
mdir -p ${SYMBOLPATH}
mv crash_generation_app.sym ${SYMBOLPATH}

Generating a minidump file

A small test application demonstrating out-of-process dumping called crash_generation_app.exe is built.

• Run it once, selecting "Server->Start" from the menu
• Run it again, selecting "Client->Deref zero"
• Client should crash, and a .dmp is written to C:\Dumps\

Processing the minidump to produce a stack trace

minidump_stackwalk blah.dmp /symbols/

Issues

Lack of build-id

On Windows, the build-id takes the form of a CodeView record. This build-id is captured for all modules in the process by MiniDumpWriteDump(), and is used by the breakpad minidump processing tools to find the matching symbol file.

See http://debuginfo.com/articles/debuginfomatch.html

I have implemented 'ld --build-id' for PE/COFF executables (See https://sourceware.org/ml/binutils/2014-01/msg00296.html), but you must use a sufficently recent version of binutils (2.25 or later) and build with '-Wl,--build-id' (or a gcc configured with '--enable-linker-build-id', which turns that flag on by default) to enable that.

A tool could be written to add a build-id to existing PE/COFF executables, but in practice this turns out to be quite tricky...

Symbols from a PDB or the Microsoft Symbol Server

symsrv_convert and dump_syms for PDB cannot be currently built with MinGW, because they require the MS DIA (Debug Interface Access) SDK (which is only in paid editions of Visual Studio) and the DIA SDK uses ATL.

An alternate PDB parser is available at https://github.com/luser/dump_syms, but that also needs some work before it can be built with MinGW.