Simulation Debugging

As the simulation is running on the host machine, all the desktop development tools are available.

CLANG Address Sanitizer (Mac OS, Linux)

The Clang address sanitizer can help to find alignment (bus) errors and other memory faults like segmentation fauls. The command below sets the right compile options.

make clean # only required on first address sanitizer run after a normal build
MEMORY_DEBUG=1 make posix jmavsim

Valgrind

brew install valgrind

or

sudo apt-get install valgrind

Start combinations

SITL can be launched with and without debugger attached and with either jMAVSim or Gazebo as simulation backend. This results in the start options below:

make posix_sitl_default jmavsim
make posix_sitl_default jmavsim___gdb
make posix_sitl_default jmavsim___lldb

make posix_sitl_default gazebo
make posix_sitl_default gazebo___gdb
make posix_sitl_default gazebo___lldb

make posix_sitl_lpe jmavsim
make posix_sitl_lpe jmavsim___gdb
make posix_sitl_lpe jmavsim___lldb

make posix_sitl_lpe gazebo
make posix_sitl_lpe gazebo___gdb
make posix_sitl_lpe gazebo___lldb

This will start the debugger and launch the SITL application. In order to break into the debugger shell and halt the execution, hit CTRL-C:

Process 16529 stopped
* thread #1: tid = 0x114e6d, 0x00007fff90f4430a libsystem_kernel.dylib`__read_nocancel + 10, name = 'px4', queue = 'com.apple.main-thread', stop reason = signal SIGSTOP
    frame #0: 0x00007fff90f4430a libsystem_kernel.dylib`__read_nocancel + 10
libsystem_kernel.dylib`__read_nocancel:
->  0x7fff90f4430a <+10>: jae    0x7fff90f44314            ; <+20>
    0x7fff90f4430c <+12>: movq   %rax, %rdi
    0x7fff90f4430f <+15>: jmp    0x7fff90f3fc53            ; cerror_nocancel
    0x7fff90f44314 <+20>: retq
(lldb)

The lldb or gdb shells behave like normal sessions, please refer to the LLDB / GDB documentation.