rust/tests/ui-fulldeps/stable-mir/check_ty_fold.rs
2024-09-25 19:00:19 -07:00

113 lines
3.5 KiB
Rust

//@ run-pass
//! Test that users are able to use stable mir APIs to retrieve monomorphized types, and that
//! we have an error handling for trying to instantiate types with incorrect arguments.
//@ ignore-stage1
//@ ignore-cross-compile
//@ ignore-remote
//@ ignore-windows-gnu mingw has troubles with linking https://github.com/rust-lang/rust/pull/116837
//@ edition: 2021
#![feature(rustc_private)]
#![feature(assert_matches)]
#[macro_use]
extern crate rustc_smir;
extern crate rustc_driver;
extern crate rustc_interface;
extern crate stable_mir;
use rustc_smir::rustc_internal;
use stable_mir::ty::{RigidTy, TyKind, Ty, };
use stable_mir::mir::{Body, MirVisitor, FieldIdx, Place, ProjectionElem, visit::{Location,
PlaceContext}};
use std::io::Write;
use std::ops::ControlFlow;
const CRATE_NAME: &str = "input";
/// This function uses the Stable MIR APIs to get information about the test crate.
fn test_stable_mir() -> ControlFlow<()> {
let main_fn = stable_mir::entry_fn();
let body = main_fn.unwrap().body();
let mut visitor = PlaceVisitor{ body: &body, tested: false};
visitor.visit_body(&body);
assert!(visitor.tested);
ControlFlow::Continue(())
}
struct PlaceVisitor<'a> {
body: &'a Body,
/// Used to ensure that the test was reachable. Otherwise this test would vacuously succeed.
tested: bool,
}
/// Check that `wrapper.inner` place projection can be correctly interpreted.
/// Ensure that instantiation is correct.
fn check_tys(local_ty: Ty, idx: FieldIdx, expected_ty: Ty) {
let TyKind::RigidTy(RigidTy::Adt(def, args)) = local_ty.kind() else { unreachable!() };
assert_eq!(def.ty_with_args(&args), local_ty);
let field_def = &def.variants_iter().next().unwrap().fields()[idx];
let field_ty = field_def.ty_with_args(&args);
assert_eq!(field_ty, expected_ty);
// Check that the generic version is different than the instantiated one.
let field_ty_gen = field_def.ty();
assert_ne!(field_ty_gen, field_ty);
}
impl<'a> MirVisitor for PlaceVisitor<'a> {
fn visit_place(&mut self, place: &Place, _ptx: PlaceContext, _loc: Location) {
let start_ty = self.body.locals()[place.local].ty;
match place.projection.as_slice() {
[ProjectionElem::Field(idx, ty)] => {
check_tys(start_ty, *idx, *ty);
self.tested = true;
}
_ => {}
}
}
}
/// This test will generate and analyze a dummy crate using the stable mir.
/// For that, it will first write the dummy crate into a file.
/// Then it will create a `StableMir` using custom arguments and then
/// it will run the compiler.
fn main() {
let path = "ty_fold_input.rs";
generate_input(&path).unwrap();
let args = vec![
"rustc".to_string(),
"-Cpanic=abort".to_string(),
"--crate-name".to_string(),
CRATE_NAME.to_string(),
path.to_string(),
];
run!(args, test_stable_mir).unwrap();
}
fn generate_input(path: &str) -> std::io::Result<()> {
let mut file = std::fs::File::create(path)?;
write!(
file,
r#"
struct Wrapper<T: Default> {{
pub inner: T
}}
impl<T: Default> Wrapper<T> {{
pub fn new() -> Wrapper<T> {{
Wrapper {{ inner: T::default() }}
}}
}}
fn main() {{
let wrapper = Wrapper::<u8>::new();
let _inner = wrapper.inner;
}}
"#
)?;
Ok(())
}