vjeux / ds2

Debug server for lldb.

ds2

ds2 is a debug server designed to be used with LLDB to perform remote debugging of Linux, Android, FreeBSD and Windows targets. Windows support is still under active development.

Requirements

ds2 needs cmake, a C++11 compiler, flex and bison.

Building ds2

ds2 uses CMake to generate its build system. A variety of CMake toolchain files are provided to help with cross compilation for other targets.

Compiling on Linux and FreeBSD

After cloning the ds2 repository, run the following commands to build for the current host:

cd ds2
mkdir build && cd build
cmake ..
make

Compiling on Windows

ds2 builds on Windows using MSVC. As with linux, use CMake to generate the build system, then use msbuild (or the script provided) to build the binary:

cd ds2
mkdir build && cd build
cmake ..
..\Support\Scripts\build-windows.bat

Cross compiling for Android

For Android native debugging, it is possible to build ds2 with a toolchain from the Android NDK. A script is provided to generate the toolchain, and a CMake toolchain file can then be used to generate the build system.

Support/Scripts/prepare-android-toolchain.sh will download a working version of the NDK, extract it, and install the toolchain to /tmp/android-ndk-arm-toolchain which can then be used for the build.

cd ds2
./Support/Scripts/prepare-android-toolchain.sh arm
mkdir build && cd build
cmake -DCMAKE_TOOLCHAIN_FILE=../Support/CMake/Toolchain-Android-ARM.cmake ..
make

Builds of ds2 targetting Android generate a static binary by default. The final build product can be copied over to the remote device and used with minimal dependencies.

Cross compiling for Linux-ARM

Cross-compiling for Linux-ARM is also possible. On Ubuntu 14.04, install gcc-4.7-arm-linux-gnueabi and g++-4.7-arm-linux-gnueabi and use the provided toolchain file.

cd ds2
mkdir build && cd build
cmake -DCMAKE_TOOLCHAIN_FILE=../Support/CMake/Toolchain-Linux-ARM.cmake ..
make

This will generate a binary that you can copy to your device to start debugging.

Running ds2

ds2 accepts the following options:

usage: ds2 [OPTIONS] [PROGRAM [ARGUMENTS...]]
  -a, --attach ARG          attach to the name or PID specified
  -R, --debug-remote        enable remote packet log output
  -d, --debug               enable debug output
  -k, --keep-alive          keep the server alive after the client disconnects
  -L, --list-processes      list processes debuggable by the current user
  -l, --lldb-compat         force ds2 to run in lldb compat mode
  -o, --log-output ARG      output log message to the file specified
  -N, --named-pipe ARG      determine a port dynamically and write back to FIFO
  -n, --no-colors           disable colored output
  -P, --platform            execute in platform mode
  -p, --port ARG            listen on the port specified
  -e, --set-env             add an element to the environment before launch
  -E, --unset-env           remove an element from the environment before lauch

After building ds2 for your target, run it with the binary to debug, or attach to an already running process. Then, start LLDB as usual and attach to the ds2 instance with the gdb-remote command.

ds2 listens on port 12345 by default; --port can be used to specify the port number to use.

Example

On the remote host

Launch ds2 with something like:

$ ./ds2 --port 4242 ./TestSimpleOutput

ds2 is now ready to accept connections on port 4242 from lldb.

On your local host

$ lldb /path/to/TestSimpleOutput
Current executable set to '/path/to/TestSimpleOutput' (x86_64).
(lldb) gdb-remote sas-ubuntu-vm.local:4242
Process 8336 stopped
* thread #1: tid = 8336, 0x00007ffff7ddb2d0, name = 'TestSimpleOutput', stop reason = signal SIGTRAP
    frame #0: 0x00007ffff7ddb2d0
-> 0x7ffff7ddb2d0:  movq   %rsp, %rdi
   0x7ffff7ddb2d3:  callq  0x7ffff7ddea70
   0x7ffff7ddb2d8:  movq   %rax, %r12
   0x7ffff7ddb2db:  movl   0x221b17(%rip), %eax
(lldb) b main
Breakpoint 1: where = TestSimpleOutput`main + 29 at TestSimpleOutput.cpp:6, address = 0x000000000040096d
[... debug debug ...]
(lldb) c
Process 8336 resuming
Process 8336 exited with status = 0 (0x00000000)
(lldb)

Join the ds2 community

See the CONTRIBUTING.md file for how to help out.

License

ds2 is licensed under the University of Illinois/NCSA Open Source License.

We also provide an additional patent grant which can be found in the PATENTS file in the root directory of this source tree.

regsgen2, a tool used to generate register definitions is also licensed under the University of Illinois/NCSA Open Source License and uses a json library licensed under the Boost Software License. A complete copy of the latter can be found in Tools/libjson/LICENSE_1_0.txt.