Rollup merge of #119563 - compiler-errors:coroutine-resume, r=oli-obk

Check yield terminator's resume type in borrowck

In borrowck, we didn't check that the lifetimes of the `TerminatorKind::Yield`'s `resume_place` were actually compatible with the coroutine's signature. That means that the lifetimes were totally going unchecked. Whoops!

This PR implements this checking.

Fixes #119564

r? types

compiler/rustc_middle/src/mir/mod.rs

@@ -249,6 +249,9 @@ pub struct CoroutineInfo<'tcx> {
     /// The yield type of the function, if it is a coroutine.
     pub yield_ty: Option<Ty<'tcx>>,
 
+    /// The resume type of the function, if it is a coroutine.
+    pub resume_ty: Option<Ty<'tcx>>,
+
     /// Coroutine drop glue.
     pub coroutine_drop: Option<Body<'tcx>>,
 
@@ -384,6 +387,7 @@ impl<'tcx> Body<'tcx> {
             coroutine: coroutine_kind.map(|coroutine_kind| {
                 Box::new(CoroutineInfo {
                     yield_ty: None,
+                    resume_ty: None,
                     coroutine_drop: None,
                     coroutine_layout: None,
                     coroutine_kind,
@@ -550,6 +554,11 @@ impl<'tcx> Body<'tcx> {
         self.coroutine.as_ref().and_then(|coroutine| coroutine.yield_ty)
     }
 
+    #[inline]
+    pub fn resume_ty(&self) -> Option<Ty<'tcx>> {
+        self.coroutine.as_ref().and_then(|coroutine| coroutine.resume_ty)
+    }
+
     #[inline]
     pub fn coroutine_layout(&self) -> Option<&CoroutineLayout<'tcx>> {
         self.coroutine.as_ref().and_then(|coroutine| coroutine.coroutine_layout.as_ref())

compiler/rustc_middle/src/mir/visit.rs

@@ -996,6 +996,12 @@ macro_rules! super_body {
                     TyContext::YieldTy(SourceInfo::outermost(span))
                 );
             }
+            if let Some(resume_ty) = $(& $mutability)? gen.resume_ty {
+                $self.visit_ty(
+                    resume_ty,
+                    TyContext::ResumeTy(SourceInfo::outermost(span))
+                );
+            }
         }
 
         for (bb, data) in basic_blocks_iter!($body, $($mutability, $invalidate)?) {
@@ -1244,6 +1250,8 @@ pub enum TyContext {
 
     YieldTy(SourceInfo),
 
+    ResumeTy(SourceInfo),
+
     /// A type found at some location.
     Location(Location),
 }