Segmentation Fault: Stack dump without symbol names

[SaeedKeshavarzi]

Here is how you can regenerate the segmentation fault:

first set this flags:

C++ Standard:
  C++ 2c
More Transformations:
  Use libc++
  Show coroutine transformation
  Show C++ to C transformation 

and the code:

#include <iostream>
#include <coroutine>
#include <thread>
#include <queue>
#include <functional>

std::queue<std::function<bool()>> task_queue;

struct sleep {
    sleep(int n) : delay{n} {}

    constexpr bool await_ready() const noexcept { return false; }

    void await_suspend(std::coroutine_handle<> h) const noexcept {
        auto start = std::chrono::steady_clock::now();
        task_queue.push([start, h, d = delay] {
            if (decltype(start)::clock::now() - start > d) {
                h.resume();
                return true;
            } else {
                return false;
            }
        });
    }

    void await_resume() const noexcept {}

    std::chrono::milliseconds delay;
};


struct Task {
    struct promise_type {
        promise_type() = default;
        Task get_return_object() { return {}; }
        std::suspend_never initial_suspend() { return {}; } 
        std::suspend_always final_suspend() noexcept { return {}; }
        void unhandled_exception() {}
    };
};

Task foo() noexcept {
    std::cout << "1. hello from foo1" << std::endl;
    for (int i = 0; i < 10; ++i) {
        co_await sleep{10};
        std::cout << "2. hello from foo1" << std::endl;
    }
}

//call foo
int main() {
    foo();
}

and the error message is:

insights: /usr/lib/llvm-18/include/clang/AST/Type.h:753: const clang::ExtQualsTypeCommonBase* clang::QualType::getCommonPtr() const: Assertion `!isNull() && "Cannot retrieve a NULL type pointer"' failed.
Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
Segmentation fault (core dumped)

Thanks for your good project cppInsights

[andreasfertig]

Hello @SaeedKeshavarzi,

thanks for reporting this issue!

I have a fix for the crash. However, please note that the two transformations don't play well together. The reason is the design of the CodeGenerator. The CoroutineCodeGenerator and the CFrontCodeGenerator both derive from CodeGenerator, so parts of the CoroutineCodeGenerator do not properly transform to C code.

Andreas