8 files changed, 19 insertions, 33 deletions
diff --git a/compiler/rustc_middle/src/mir/consts.rs b/compiler/rustc_middle/src/mir/consts.rs
index d8a39191920..1231ea88569 100644
--- a/compiler/rustc_middle/src/mir/consts.rs
+++ b/compiler/rustc_middle/src/mir/consts.rs
@@ -5,7 +5,7 @@ use rustc_hir::def_id::DefId;
 use rustc_macros::{HashStable, Lift, TyDecodable, TyEncodable, TypeFoldable, TypeVisitable};
 use rustc_session::RemapFileNameExt;
 use rustc_session::config::RemapPathScopeComponents;
-use rustc_span::{DUMMY_SP, Span};
+use rustc_span::{DUMMY_SP, Span, Symbol};
 use rustc_type_ir::visit::TypeVisitableExt;
 
 use super::interpret::ReportedErrorInfo;
@@ -569,7 +569,7 @@ impl<'tcx> TyCtxt<'tcx> {
         let topmost = span.ctxt().outer_expn().expansion_cause().unwrap_or(span);
         let caller = self.sess.source_map().lookup_char_pos(topmost.lo());
         self.const_caller_location(
-            rustc_span::symbol::Symbol::intern(
+            Symbol::intern(
                 &caller
                     .file
                     .name
diff --git a/compiler/rustc_middle/src/mir/coverage.rs b/compiler/rustc_middle/src/mir/coverage.rs
index 962176290df..29f26180c97 100644
--- a/compiler/rustc_middle/src/mir/coverage.rs
+++ b/compiler/rustc_middle/src/mir/coverage.rs
@@ -154,22 +154,6 @@ impl Debug for CoverageKind {
     }
 }
 
-#[derive(Clone, TyEncodable, TyDecodable, Hash, HashStable, PartialEq, Eq, PartialOrd, Ord)]
-#[derive(TypeFoldable, TypeVisitable)]
-pub struct SourceRegion {
-    pub start_line: u32,
-    pub start_col: u32,
-    pub end_line: u32,
-    pub end_col: u32,
-}
-
-impl Debug for SourceRegion {
-    fn fmt(&self, fmt: &mut Formatter<'_>) -> fmt::Result {
-        let &Self { start_line, start_col, end_line, end_col } = self;
-        write!(fmt, "{start_line}:{start_col} - {end_line}:{end_col}")
-    }
-}
-
 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, HashStable)]
 #[derive(TyEncodable, TyDecodable, TypeFoldable, TypeVisitable)]
 pub enum Op {
@@ -231,7 +215,7 @@ impl MappingKind {
 #[derive(TyEncodable, TyDecodable, Hash, HashStable, TypeFoldable, TypeVisitable)]
 pub struct Mapping {
     pub kind: MappingKind,
-    pub source_region: SourceRegion,
+    pub span: Span,
 }
 
 /// Stores per-function coverage information attached to a `mir::Body`,
diff --git a/compiler/rustc_middle/src/mir/interpret/error.rs b/compiler/rustc_middle/src/mir/interpret/error.rs
index fbada6ec405..37328470aa7 100644
--- a/compiler/rustc_middle/src/mir/interpret/error.rs
+++ b/compiler/rustc_middle/src/mir/interpret/error.rs
@@ -392,7 +392,7 @@ pub enum UndefinedBehaviorInfo<'tcx> {
     /// A discriminant of an uninhabited enum variant is written.
     UninhabitedEnumVariantWritten(VariantIdx),
     /// An uninhabited enum variant is projected.
-    UninhabitedEnumVariantRead(VariantIdx),
+    UninhabitedEnumVariantRead(Option<VariantIdx>),
     /// Trying to set discriminant to the niched variant, but the value does not match.
     InvalidNichedEnumVariantWritten { enum_ty: Ty<'tcx> },
     /// ABI-incompatible argument types.
diff --git a/compiler/rustc_middle/src/mir/mod.rs b/compiler/rustc_middle/src/mir/mod.rs
index 56340ff0095..98ef7d58a50 100644
--- a/compiler/rustc_middle/src/mir/mod.rs
+++ b/compiler/rustc_middle/src/mir/mod.rs
@@ -26,8 +26,7 @@ use rustc_index::{Idx, IndexSlice, IndexVec};
 use rustc_macros::{HashStable, TyDecodable, TyEncodable, TypeFoldable, TypeVisitable};
 use rustc_serialize::{Decodable, Encodable};
 use rustc_span::source_map::Spanned;
-use rustc_span::symbol::Symbol;
-use rustc_span::{DUMMY_SP, Span};
+use rustc_span::{DUMMY_SP, Span, Symbol};
 use tracing::trace;
 
 pub use self::query::*;
@@ -1349,8 +1348,8 @@ pub struct BasicBlockData<'tcx> {
 }
 
 impl<'tcx> BasicBlockData<'tcx> {
-    pub fn new(terminator: Option<Terminator<'tcx>>) -> BasicBlockData<'tcx> {
-        BasicBlockData { statements: vec![], terminator, is_cleanup: false }
+    pub fn new(terminator: Option<Terminator<'tcx>>, is_cleanup: bool) -> BasicBlockData<'tcx> {
+        BasicBlockData { statements: vec![], terminator, is_cleanup }
     }
 
     /// Accessor for terminator.
diff --git a/compiler/rustc_middle/src/mir/mono.rs b/compiler/rustc_middle/src/mir/mono.rs
index 266dc7ad2b3..27168b2a9f2 100644
--- a/compiler/rustc_middle/src/mir/mono.rs
+++ b/compiler/rustc_middle/src/mir/mono.rs
@@ -1,7 +1,7 @@
 use std::fmt;
 use std::hash::Hash;
 
-use rustc_attr::InlineAttr;
+use rustc_attr_parsing::InlineAttr;
 use rustc_data_structures::base_n::{BaseNString, CASE_INSENSITIVE, ToBaseN};
 use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_data_structures::fx::FxIndexMap;
@@ -13,8 +13,7 @@ use rustc_index::Idx;
 use rustc_macros::{HashStable, TyDecodable, TyEncodable};
 use rustc_query_system::ich::StableHashingContext;
 use rustc_session::config::OptLevel;
-use rustc_span::Span;
-use rustc_span::symbol::Symbol;
+use rustc_span::{Span, Symbol};
 use rustc_target::spec::SymbolVisibility;
 use tracing::debug;
 
diff --git a/compiler/rustc_middle/src/mir/pretty.rs b/compiler/rustc_middle/src/mir/pretty.rs
index 2bfcd0a6227..2d1a0e36f90 100644
--- a/compiler/rustc_middle/src/mir/pretty.rs
+++ b/compiler/rustc_middle/src/mir/pretty.rs
@@ -23,6 +23,7 @@ pub(crate) const ALIGN: usize = 40;
 
 /// An indication of where we are in the control flow graph. Used for printing
 /// extra information in `dump_mir`
+#[derive(Clone)]
 pub enum PassWhere {
     /// We have not started dumping the control flow graph, but we are about to.
     BeforeCFG,
@@ -603,8 +604,8 @@ fn write_function_coverage_info(
     for (id, expression) in expressions.iter_enumerated() {
         writeln!(w, "{INDENT}coverage {id:?} => {expression:?};")?;
     }
-    for coverage::Mapping { kind, source_region } in mappings {
-        writeln!(w, "{INDENT}coverage {kind:?} => {source_region:?};")?;
+    for coverage::Mapping { kind, span } in mappings {
+        writeln!(w, "{INDENT}coverage {kind:?} => {span:?};")?;
     }
     writeln!(w)?;
 
diff --git a/compiler/rustc_middle/src/mir/query.rs b/compiler/rustc_middle/src/mir/query.rs
index f690359e012..429be9bc725 100644
--- a/compiler/rustc_middle/src/mir/query.rs
+++ b/compiler/rustc_middle/src/mir/query.rs
@@ -11,8 +11,7 @@ use rustc_hir::def_id::LocalDefId;
 use rustc_index::bit_set::BitMatrix;
 use rustc_index::{Idx, IndexVec};
 use rustc_macros::{HashStable, TyDecodable, TyEncodable, TypeFoldable, TypeVisitable};
-use rustc_span::Span;
-use rustc_span::symbol::Symbol;
+use rustc_span::{Span, Symbol};
 use smallvec::SmallVec;
 
 use super::{ConstValue, SourceInfo};
diff --git a/compiler/rustc_middle/src/mir/syntax.rs b/compiler/rustc_middle/src/mir/syntax.rs
index fea940ea47c..0c17a2e0fe5 100644
--- a/compiler/rustc_middle/src/mir/syntax.rs
+++ b/compiler/rustc_middle/src/mir/syntax.rs
@@ -10,10 +10,9 @@ use rustc_hir::CoroutineKind;
 use rustc_hir::def_id::DefId;
 use rustc_index::IndexVec;
 use rustc_macros::{HashStable, TyDecodable, TyEncodable, TypeFoldable, TypeVisitable};
-use rustc_span::Span;
 use rustc_span::def_id::LocalDefId;
 use rustc_span::source_map::Spanned;
-use rustc_span::symbol::Symbol;
+use rustc_span::{Span, Symbol};
 use rustc_target::asm::InlineAsmRegOrRegClass;
 use smallvec::SmallVec;
 
@@ -822,6 +821,11 @@ pub enum TerminatorKind<'tcx> {
     /// continues at the `resume` basic block, with the second argument written to the `resume_arg`
     /// place. If the coroutine is dropped before then, the `drop` basic block is invoked.
     ///
+    /// Note that coroutines can be (unstably) cloned under certain conditions, which means that
+    /// this terminator can **return multiple times**! MIR optimizations that reorder code into
+    /// different basic blocks needs to be aware of that.
+    /// See <https://github.com/rust-lang/rust/issues/95360>.
+    ///
     /// Not permitted in bodies that are not coroutine bodies, or after coroutine lowering.
     ///
     /// **Needs clarification**: What about the evaluation order of the `resume_arg` and `value`?