https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95477
Bug ID: 95477 Summary: [coroutines] coroutine result object not properly freed Product: gcc Version: 10.1.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: natattak at gmail dot com Target Milestone: --- In some cases, the result object of a coroutine is not properly destroyed after the coroutine finishes execution. Consider the following example: #include <coroutine> struct simple { static inline int alive = 0; simple() { ++alive; } simple(simple&&) { ++alive; } ~simple() { --alive; } struct promise_type { simple get_return_object() { return simple{}; } void return_void() {} void unhandled_exception() {} auto initial_suspend() noexcept { return std::suspend_never{}; } auto final_suspend() noexcept { return std::suspend_never{}; } }; }; simple f() { co_return; } int main() { { f(); } return simple::alive; } The return value should be 0, indicating that all created objects were destroyed. However, when executing, I get the result 1. After commenting out the move constructor, the return value is 0 as expected. See also: https://stackoverflow.com/questions/62125871/simple-coroutine-leaking-with-gcc-10 This is compiled using `-std=c++20 -fcoroutines`. My `gcc -v` is: Using built-in specs. COLLECT_GCC=g++ COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/10.1.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=https://bugs.archlinux.org/ --enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++,d --with-isl --with-linker-hash-style=gnu --with-system-zlib --enable-__cxa_atexit --enable-cet=auto --enable-checking=release --enable-clocale=gnu --enable-default-pie --enable-default-ssp --enable-gnu-indirect-function --enable-gnu-unique-object --enable-install-libiberty --enable-linker-build-id --enable-lto --enable-multilib --enable-plugin --enable-shared --enable-threads=posix --disable-libssp --disable-libstdcxx-pch --disable-libunwind-exceptions --disable-werror gdc_include_dir=/usr/include/dlang/gdc Thread model: posix Supported LTO compression algorithms: zlib zstd gcc version 10.1.0 (GCC)