Connecting USB joystick crashes "testcontroller" app

[mikekov]

I can cause "testcontroller" app to crash by connecting old USB joystick to my macbook:

* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x1029fd6b56a0)
    frame #0: 0x00000001801378f8 libobjc.A.dylib`objc_retain + 16
libobjc.A.dylib`objc_retain:
->  0x1801378f8 <+16>: ldr    x17, [x17, #0x20]
    0x1801378fc <+20>: tbz    w17, #0x2, 0x1801378b4    ; ___lldb_unnamed_symbol1452
    0x180137900 <+24>: tbz    w16, #0x0, 0x1801378dc    ; ___lldb_unnamed_symbol1452 + 40
    0x180137904 <+28>: lsr    x17, x16, #55
Target 0: (testcontroller) stopped.
(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x1029fd6b56a0)
  * frame #0: 0x00000001801378f8 libobjc.A.dylib`objc_retain + 16
    frame #1: 0x0000000100982dc0 libSDL3.1.0.0.dylib`IOS_MFIJoystickUpdate(joystick=0x0000000107f1ca00) at SDL_mfijoystick.m:1159:13
    frame #2: 0x000000010097e9f0 libSDL3.1.0.0.dylib`IOS_JoystickUpdate(joystick=0x0000000107f1ca00) at SDL_mfijoystick.m:1719:9
    frame #3: 0x0000000100830f3c libSDL3.1.0.0.dylib`SDL_OpenJoystick_REAL(instance_id=3) at SDL_joystick.c:1114:5
    frame #4: 0x00000001007eda9c libSDL3.1.0.0.dylib`SDL_OpenJoystick(a=3) at SDL_dynapi_procs.h:527:1
    frame #5: 0x0000000100005078 testcontroller`AddController(id=3, verbose=1) at testcontroller.c:871:32
    frame #6: 0x000000010000369c testcontroller`loop(arg=0x0000000000000000) at testcontroller.c:1513:13
    frame #7: 0x000000010000329c testcontroller`main(argc=1, argv=0x000000016fdff2e8) at testcontroller.c:2108:9
    frame #8: 0x00000001801850e0 dyld`start + 2360

If there's something I can do to help diagnose it further, please let me know.

SDL3 built from master, as of Feb 7, 2024.

[slouken]

Is controller.physicalInputProfile nil in this case?

[mikekov]

I think controller.physicalInputProfile is not nil: "joy profile: 0x134822df0"

Now I have it crash at this line: for (id key in device->buttons) {.

axis looks valid, but buttons NSArray does not:

...but on another attempt it crashes accessing axes:

In yet another attempt crash iterating axies, even though array seems to be present:

[mikekov]

axes is probably collected, as it points to garbage. Removing __unsafe_unretained form its declaration resolves the issue for me, but I don't know why this qualifier was there or how to properly free axes now.

[slouken]

Good find, thanks! I'll take care of that.

[slouken]

This is fixed, thanks!