Using crashpad with content shell

When running web tests, it is possible to use crashpad/breakpad to capture stack traces on crashes while running without a debugger attached and with the sandbox enabled.

Setup

On all platforms, build the target blink_tests.

Mac: Add enable_dsyms = 1 to your gn build arguments before building. This slows down linking several minutes, so don't just always set it by default.

Linux: Add use_debug_fission = true to your gn build arguments before building.

Then, create a directory where the crash dumps will be stored:

• Linux/Mac:

  mkdir /tmp/crashes
  

• Android:

  adb root
  adb shell mkdir /data/data/org.chromium.content_shell_apk/cache
  

• Windows:

  mkdir %TEMP%\crashes
  

Running content shell with crashpad

Crashpad can be enabled by passing --enable-crash-reporter and --crash-dumps-dir to content shell:

• Linux:

  out/Debug/content_shell --enable-crash-reporter \
      --crash-dumps-dir=/tmp/crashes chrome://crash
  

• Mac:

  out/Debug/Content\ Shell.app/Contents/MacOS/Content\ Shell \
      --enable-crash-reporter --crash-dumps-dir=/tmp/crashes chrome://crash
  

• Windows:

  out\Default\content_shell.exe --enable-crash-reporter ^
      --crash-dumps-dir=%TEMP%\crashes chrome://crash
  

• Android:

  out/Default/bin/content_shell_apk install
  out/Default/bin/content_shell_apk launch chrome://crash
  --args="--enable-crash-reporter --crash-dumps-dir=/data/data/org.chromium.content_shell_apk/cache"
  

Retrieving the crash dump

On Linux and Android, we first have to retrieve the crash dump. On Mac and Windows, this step can be skipped.

• Linux:

  components/crash/content/tools/dmp2minidump.py /tmp/crashes/*.dmp /tmp/minidump
  

• Android:

  adb pull $(adb shell ls /data/data/org.chromium.content_shell_apk/cache/pending/*.dmp) /tmp/chromium-renderer-minidump.dmp
  

Symbolizing the crash dump

On all platforms except for Windows, we need to convert the debug symbols to a format that breakpad can understand.

• Linux:

  components/crash/content/tools/generate_breakpad_symbols.py \
      --build-dir=out/Default --binary=out/Default/content_shell \
      --symbols-dir=out/Default/content_shell.breakpad.syms --clear --jobs=16
  

• Mac:

  components/crash/content/tools/generate_breakpad_symbols.py \
      --build-dir=out/Default \
      --binary=out/Default/Content\ Shell.app/Contents/MacOS/Content\ Shell \
      --symbols-dir=out/Default/content_shell.breakpad.syms --clear --jobs=16
  

• Android:

  components/crash/content/tools/generate_breakpad_symbols.py \
      --build-dir=out/Default \
      --binary=out/Default/lib/libcontent_shell_content_view.so \
      --symbols-dir=out/Default/content_shell.breakpad.syms --clear \
      --platform=android
  

Now we can generate a stack trace from the crash dump. Assuming the crash dump is in minidump.dmp:

• Linux/Android/Mac:

  out/Default/minidump_stackwalk minidump.dmp out/Debug/content_shell.breakpad.syms
  

• Windows:

  "c:\Program Files (x86)\Windows Kits\8.0\Debuggers\x64\cdb.exe" ^
      -y out\Default -c ".ecxr;k30;q" -z minidump.dmp