Chrome on Android has java and c/c++ code. Each “side” have its own set of tools for debugging. Here's some tips.
Various commands below requires setting up command line flags.
# Content shell build/android/adb_content_shell_command_line --flags --to-pass # Chromium test shell build/android/adb_chrome_shell_command_line --flags --to-pass
You can launch the app by using one of the wrappers. You can pass URLs directly too.
# Content shell build/android/adb_run_content_shell 'data:text/html;utf-8,<html>Hello World!</html>' # Chromium test shell build/android/adb_run_chrome_shell 'data:text/html;utf-8,<html>Hello World!</html>'
Chromium logging from LOG(INFO) etc., is directed to the Android logcat logging facility. You can filter the messages, e.g. view chromium verbose logging, everything else at warning level with:
adb logcat chromium:V cr.SomeComponent:V *:W
Do not use fprintf or printf debugging! This does not redirect to logcat.
While your phone is plugged into USB, use the
screenshot.py tool in
envsetup.sh should have put it in your path.
While your phone is plugged into USB, you can inspect the Android view hierarchy using the following command:
ANDROID_HVPROTO allows you to inspect debuggable apps on non-rooted devices. When building a local version of Chromium, the build tools automatically add
android:debuggable=true to the
AndroidManifest.xml, which will allow you to inspect them on rooted devices.
Want to add some additional information to your Views? You can do that by adding the @ViewDebug.ExportedProperty annotation.
@ViewDebug.ExportedProperty(category="chrome") private int mSuperNiftyDrawingProperty;
In Eclipse, make a debug configuration of type “Remote Java Application”. Choose a “Name” and set “Port” to
Make sure Eclipse Preferences > Run/Debug > Launching > “Build (if required) before launching” is unchecked.
Run Android Device Monitor:
Now select the process you want to debug in Device Monitor (the port column should now mention 8700 or xxxx/8700).
Run your debug configuration, and switch to the Debug perspective.
Build and install the desired target
Click the “Attach debugger to Android process” (see here for more)
--wait-for-java-debuggeras a command line flag.
build/android, there are a few scripts:
# Convenient wrappers build/android/adb_gdb_content_shell build/android/adb_gdb_chrome_shell # Underlying script, try --help for comprehensive list of options build/android/adb_gdb
By default, these wrappers will attach to the browser process.
You can also attach to the renderer process by using
--sandboxed. (You might need to be root on the phone for that. Run
adb root if needed)
Set the target command line flag with
Launch the debugger using one of the
adb_gdb scripts from above.
info threads and look for a line like:
11 Thread 2564 clock_gettime () at bionic/libc/arch-arm/syscalls/clock_gettime.S:11
1 Thread 10870 0x40127050 in nanosleep () from /tmp/user-adb-gdb-libs/system/lib/libc.so
We need to jump out of its sleep routine:
(gdb) thread 11 (gdb) up (gdb) up (gdb) return Make base::debug::BreakDebugger() return now? (y or n) y (gdb) continue
If a crash has generated a tombstone in your device, use:
build/android/tombstones.py --output-directory out/Default
If you have a stack trace (from
adb logcat) that needs to be symbolized, copy it into a text file and symbolize with the following command (run from
third_party/android_platform/development/scripts/stack --output-directory out/Default [tombstone file | dump file]
stack can also take its input from
adb logcat -d | third_party/android_platform/development/scripts/stack --output-directory out/Default
third_party/android_platform/development/scripts/stack --output-directory out/Default ~/crashlogs/tombstone_07-build231.txt
You will need the ProGuard mapping file that was generated when the application that crashed was built. When building locally, these are found in:
out/Default/apks/ChromePublic.apk.mapping out/Default/apks/ChromeModernPublic.apk.mapping etc.
ninja -C out/Default java_deobfuscate
Then run it via:
# For a file: out/Default/bin/java_deobfuscate PROGUARD_MAPPING_FILE.mapping < FILE # For logcat: adb logcat | out/Default/bin/java_deobfuscate PROGUARD_MAPPING_FILE.mapping
In your build environment:
adb root adb shell stop adb shell setprop log.redirect-stdio true adb shell start
In the source itself, use
fprintf(stderr, "message"); whenever you need to output a message.
To run unit tests use the following command:
out/Debug/bin/run_test_name -f <test_filter_if_any> --wait-for-debugger -t 6000
That command will cause the test process to wait until a debugger is attached.
To attach a debugger:
build/android/adb_gdb --output-directory=out/Default --package-name=org.chromium.native_test
After attaching gdb to the process you can use it normally. For example:
(gdb) break main Breakpoint 1 at 0x9750793c: main. (2 locations) (gdb) continue