Sole infinite loop crashes

[raviqqe]

Description

The following code doesn't work as it returns unexpectedly.

main : System -> Number
main sys = main sys

The cause seems to be:

• https://reviews.llvm.org/D94106
• LLVM loop optimization can make safe programs crash rust-lang/rust#28728
• https://stackoverflow.com/questions/59925618/how-do-i-make-an-infinite-empty-loop-that-wont-be-optimized-away

C equivalent

• clang v11 builds the following code successfully.
• But the executable crashes at runtime.
• gcc v5.5.0 compiles it to an infinite loop.

int main() { return main(); }

Solution

• Upgrade to LLVM 12.