C++ debugger crashes on M2 Mac when using SDL and std::map

[Rojetto]

Type: Bug

While working on a project using SDL, I ran into a weird issue where after setting a breakpoint, the VS Code debugger (using lldb) would stop at the breakpoint and show the stack trace, but couldn't load variables or step. The program then also froze, even after stopping the debugger and had to be force quit. I reduced it to the following minimal example:

main.cpp

#include <SDL.h>
#include <map>

int main() {
    if (SDL_Init(SDL_INIT_VIDEO) != 0)
    {
        return -1;
    }

    std::map<int, int> badMap;

    return 0;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.15)
project(LLDB Repro)

# Set the C++ standard to be used for compilation
set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

# Define the source files to be compiled
file(GLOB_RECURSE SOURCE_FILES 
    main.cpp
)

# Create an executable from the source files
add_executable(${PROJECT_NAME} ${SOURCE_FILES})

# Find the SDL2 package
find_package(SDL2 REQUIRED)

# Add the SDL2 include directories and link the SDL2 libraries
target_include_directories(${PROJECT_NAME} PRIVATE ${SDL2_INCLUDE_DIRS})
target_link_libraries(${PROJECT_NAME} ${SDL2_LIBRARIES})

launch.json

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "(lldb) Launch",
            "type": "cppdbg",
            "request": "launch",
            "program": "${command:cmake.launchTargetPath}",
            "args": [],
            "stopAtEntry": false,
            "cwd": "${workspaceFolder}",
            "environment": [],
            "externalConsole": false,
            "MIMode": "lldb"
        }
    ],
}

c_cpp_properties.json

{
    "configurations": [
        {
            "name": "Mac",
            "includePath": [
                "${workspaceFolder}/**"
            ],
            "defines": [],
            "macFrameworkPath": [
                "/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks"
            ],
            "compilerPath": "/usr/bin/clang",
            "cStandard": "c17",
            "cppStandard": "c++20",
            "intelliSenseMode": "macos-clang-arm64",
            "configurationProvider": "ms-vscode.cmake-tools"
        }
    ],
    "version": 4
}

If I set a breakpoint in the main function, VS Code will break there, but then something crashes internally. If you remove either the map or SDL_Init, the problem disappears. I also tried debugging manually from the command line with LLDB, but there the issue doesn't appear.

robert@RMBA LLDB Repro % lldb --version
lldb-1403.0.17.64
Apple Swift version 5.8 (swiftlang-5.8.0.124.2 clang-1403.0.22.11.100)
robert@RMBA LLDB Repro % brew list --versions sdl2
sdl2 2.26.5

Extension version: 1.15.4
VS Code version: Code 1.78.2 (Universal) (b3e4e68a0bc097f0ae7907b217c1119af9e03435, 2023-05-10T14:44:45.204Z)
OS version: Darwin arm64 22.4.0
Modes:
Sandboxed: Yes

System Info

Item	Value
CPUs	Apple M2 (8 x 24)
GPU Status	2d_canvas: enabled canvas_oop_rasterization: disabled_off direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled metal: disabled_off multiple_raster_threads: enabled_on opengl: enabled_on rasterization: enabled raw_draw: disabled_off_ok video_decode: enabled video_encode: enabled vulkan: disabled_off webgl: enabled webgl2: enabled webgpu: enabled
Load (avg)	2, 2, 2
Memory (System)	8.00GB (0.08GB free)
Process Argv	--crash-reporter-id 87b0c4e4-4f3b-445b-9f36-34444426ed13
Screen Reader	no
VM	0%

A/B Experiments

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vscod805:30301674
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bridge0708:30335490
bridge0723:30353136
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vsclangdc:30486549
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showlangstatbar:30737416
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pythonms35:30701012
pythonfmttext:30731395
fixhidewlkth:30730051
pythongtdpathcf:30739705

[H-G-Hristov]

There are multiple reports on that. You can find them and link them here.

Just install CodeLLDB.

#10816
#7240
#5805
#9831
lldb-tools/lldb-mi#101

[Rojetto]

Thanks, CodeLLDB seems to work much better even in normal operation.