tests/cxx-coroutines.nix
C++20 coroutines (lowered before FilPizlonator) and musttail calls. A musttail call pops its frame only when its caller roots the arguments, so symmetric transfer uses stack and musttail.c is only constant-stack at -O2, where its pointer argument is the caller's own argument.
λpkgsFilc
pkgsFilc.stdenv.mkDerivation
for opt in -O0 -O2; do
$CXX -std=c++20 $opt ${./cxx-coroutine-task.cpp} -o task
./task 10000 | tee task.log
grep -q 'leaf6,\[seven\],leaf8' task.log
grep -q 'deep=10001' task.log
$CXX -std=c++20 $opt ${./cxx-coroutine-gc.cpp} -o gc
./gc | grep -q 'ok allocs=2000 frees=2000'
$CXX -std=c++20 $opt ${./cxx-coroutine-uaf.cpp} -o uaf
if ./uaf > uaf.log 2>&1; then
echo "resuming a destroyed coroutine was not caught" >&2
exit 1
fi
grep -q 'pointer to free object' uaf.log
$CC $opt ${./musttail-root.c} -o musttail-root
./musttail-root | grep -q 'p is live, tag 42'
done
$CC -O2 ${./musttail.c} -o musttail
./musttail | grep -q 'qbcdefghijklmnop 1'
touch "$out"