rust/tests/coverage-map/status-quo/generator.rs
Zalathar 3141177995 Copy most of tests/run-coverage into tests/coverage-map/status-quo
The output of these tests is too complicated to comfortably verify by hand, but
we can still use them to observe changes to the underlying mappings produced by
codegen/LLVM.

If these tests fail due to non-coverage changes (e.g. in HIR-to-MIR lowering or
MIR optimizations), it should usually be OK to just `--bless` them, as long as
the `run-coverage` test suite still works.
2023-09-05 11:55:34 +10:00

31 lines
1.0 KiB
Rust

#![feature(generators, generator_trait)]
use std::ops::{Generator, GeneratorState};
use std::pin::Pin;
// The following implementation of a function called from a `yield` statement
// (apparently requiring the Result and the `String` type or constructor)
// creates conditions where the `generator::StateTransform` MIR transform will
// drop all `Counter` `Coverage` statements from a MIR. `simplify.rs` has logic
// to handle this condition, and still report dead block coverage.
fn get_u32(val: bool) -> Result<u32, String> {
if val { Ok(1) } else { Err(String::from("some error")) }
}
fn main() {
let is_true = std::env::args().len() == 1;
let mut generator = || {
yield get_u32(is_true);
return "foo";
};
match Pin::new(&mut generator).resume(()) {
GeneratorState::Yielded(Ok(1)) => {}
_ => panic!("unexpected return from resume"),
}
match Pin::new(&mut generator).resume(()) {
GeneratorState::Complete("foo") => {}
_ => panic!("unexpected return from resume"),
}
}