oncealong / flutter_lldb

flutter engine remote debug with lldb

flutter_lldb

flutter engine remote debug with lldb

See Flutter Engine C++ 源码调试初探

how to use

1、 clone this repository

git clone https://github.com/lizhangqu/flutter_lldb.git

2、 build your local engine

• Flutter Engine 编译指北
• Compiling-the-engine

3、 build your debuggable apk with the built local engine

/path/to/flutter build apk \
--debug \
--target-platform=android-arm \
--local-engine-src-path=/Users/lizhangqu/software/flutter_dev/engine/src \
--local-engine=android_debug_unopt

4、 install the built apk

adb install /path/to/sample.apk

5、 launch the built apk

You can use monkey command to run apk directly.

adb shell monkey -p com.example.package_name -v 1

6、run lldb-server in remote device with flutter_lldb

You must set environment named ANDROID_HOME or provide the android sdk home with --android-sdk

[] in the command is optional and the value is default. android-sdk default use the environment named ANDROID_HOME

The package name parameter is required.

Now run flutter_lldb

./flutter_lldb \
[--android-sdk /path/to/androidSdk] \
[--abi armeabi] \
[--local-engine-src-path=/path/to/engine/src] \
[--local-engine=android_debug_unopt] \
[--build-dir=/path/to/your/engine/build] \
[--symbol-dir=/path/to/your/engine/symbol] \
com.example.package_name

There is a sample command

./flutter_lldb \
--local-engine-src-path=/Users/lizhangqu/software/flutter_dev/engine/src \
--local-engine=android_debug_unopt \
com.vdian.flutter.wdb_buyer.example

Now you can see the output. There is a visual studio code config. Copy it to launch.json.

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "remote_lldb",
            "type": "lldb",
            "request": "attach",
            "pid": "17331",
            "initCommands": [
                "platform select remote-android",
                "platform connect unix-abstract-connect:///data/data/com.vdian.flutter.wdb_buyer.example/debug.socket"
            ],
            "postRunCommands": [
                "add-dsym /Users/lizhangqu/software/flutter_dev/engine/src/out/android_debug_unopt/libflutter.so",
                "settings set target.source-map /Users/lizhangqu/software/flutter_dev/engine/src /Users/lizhangqu/software/flutter_dev/engine/src"
            ],
        }
    ]
}
    

or

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "remote_lldb",
            "type": "lldb",
            "request": "attach",
            "pid": "get pid by execute `adb shell pidof com.vdian.flutter.wdb_buyer.example` yourself",
            "initCommands": [
                "platform select remote-android",
                "platform connect unix-abstract-connect:///data/data/com.vdian.flutter.wdb_buyer.example/debug.socket"
            ],
            "preRunCommands": [
                "settings append target.exec-search-paths /Users/lizhangqu/software/flutter_dev/engine/src/out/android_debug_unopt"
            ],
            "postRunCommands": [
                "settings set target.source-map /Users/lizhangqu/software/flutter_dev/engine/src /Users/lizhangqu/software/flutter_dev/engine/src"
            ],
        }
    ]
}

The first config only can be used for that the libfluttser.so has already been loaded into memory.

7、use visual studio code to remote debug

Install Extensions in Visual Studio Code

• C/C++
• CodeLLDB

Copy the file /path/to/engine/src/out/compile_commands.json to /path/to/engine/src/flutter/compile_commands.json

Use Visual Studio Code to open project /path/to/engine/src/flutter

Config the .vscode/launch.json by flutter_lldb generated

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "remote_lldb",
            "type": "lldb",
            "request": "attach",
            "pid": "17331",
            "initCommands": [
                "platform select remote-android",
                "platform connect unix-abstract-connect:///data/data/com.vdian.flutter.wdb_buyer.example/debug.socket"
            ],
            "postRunCommands": [
                "add-dsym /Users/lizhangqu/software/flutter_dev/engine/src/out/android_debug_unopt/libflutter.so",
                "settings set target.source-map /Users/lizhangqu/software/flutter_dev/engine/src /Users/lizhangqu/software/flutter_dev/engine/src"
            ],
        }
    ]
} 

or

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "remote_lldb",
            "type": "lldb",
            "request": "attach",
            "pid": "get pid by execute `adb shell pidof com.vdian.flutter.wdb_buyer.example` yourself",
            "initCommands": [
                "platform select remote-android",
                "platform connect unix-abstract-connect:///data/data/com.vdian.flutter.wdb_buyer.example/debug.socket"
            ],
            "preRunCommands": [
                "settings append target.exec-search-paths /Users/lizhangqu/software/flutter_dev/engine/src/out/android_debug_unopt"
            ],
            "postRunCommands": [
                "settings set target.source-map /Users/lizhangqu/software/flutter_dev/engine/src /Users/lizhangqu/software/flutter_dev/engine/src"
            ],
        }
    ]
}

The first config only can be used for that the libfluttser.so has already been loaded into memory.

Now run it and set a breakpoint.