Bug: std::println() and std::format() cause cosmoc++ to fail

[jcbhmr]

Contact Details

[email protected]

What happened?

Trying to use std::println() seems to cause cosmoc++ to hang and crash.

#include <print>

int main() {
  std::println("Hello {}!", "Ada Lovelace");
  return 0;
}

cosmoc++ -std=c++23 main.cpp

cosmoc++: x86_64 succeeded but aarch64 failed to build object
aarch64-linux-cosmo-g++: fatal error: SIGTERM signal terminated program cc1plus
compilation terminated.

The same program works fine with Zig v0.13.0 (Clang v18.1.6) zig c++

zig c++ -std=c++23 main.cpp
./a.out

Hello Ada Lovelace!

I'm using GitHub Codespaces default image. Ubuntu 20.04 x86_64

This same thing also happens with std::format().

#include <format>
#include <iostream>

int main() {
  std::cout << std::format("Hello {}!", "Alan Turing") << "\n";
  return 0;
}

x86_64-linux-cosmo-g++: fatal error: SIGTERM signal terminated program cc1plus
compilation terminated.

I ran it multiple times and it's weird: if I run cosmoc++ -std=c++23 main.cpp on either of the std::println() or std::format() programs there's like a 50/50 chance the x86_64 one will fail, or else it will succeed but the aarch64 one fails. I don't know what it is.

Version

cosmocc (GCC) 14.1.0

What operating system are you seeing the problem on?

Linux

Relevant log output

# std::println()
cosmoc++: x86_64 succeeded but aarch64 failed to build object
aarch64-linux-cosmo-g++: fatal error: SIGTERM signal terminated program cc1plus
compilation terminated.
# OR
x86_64-linux-cosmo-g++: fatal error: SIGTERM signal terminated program cc1plus
compilation terminated.



# std::format()
x86_64-linux-cosmo-g++: fatal error: SIGTERM signal terminated program cc1plus
compilation terminated.
# OR
cosmoc++: x86_64 succeeded but aarch64 failed to build object
aarch64-linux-cosmo-g++: fatal error: SIGTERM signal terminated program cc1plus
compilation terminated.