Rollup merge of #146552 - cjgillot:resume-noremap, r=jackh726

StateTransform: Do not renumber resume local.

MIR parameters are not explicitly assigned-to when entering the MIR body. If we want to save their values inside the coroutine state, we need to do so explicitly.

This was done by renaming the `_2` local, and introducing an explicit assignment pre-transform. This particular trick confuses me.

This version makes explicit that we are assigning parameters to saved locals.

r? ``@dingxiangfei2009``

2 files changed, 21 insertions, 25 deletions

diff --git a/tests/ui/rustc_public-ir-print/async-closure.rs b/tests/ui/rustc_public-ir-print/async-closure.rs
index 80f96e09cfc..bd8c7e888a3 100644
--- a/tests/ui/rustc_public-ir-print/async-closure.rs
+++ b/tests/ui/rustc_public-ir-print/async-closure.rs
@@ -1,6 +1,6 @@
 //@ compile-flags: -Z unpretty=stable-mir --crate-type lib -C panic=abort -Zmir-opt-level=0
 //@ check-pass
-//@ only-x86_64
+//@ only-64bit
 //@ edition: 2024
 //@ needs-unwind unwind edges are different with panic=abort
 
diff --git a/tests/ui/rustc_public-ir-print/async-closure.stdout b/tests/ui/rustc_public-ir-print/async-closure.stdout
index 73e9b8fc097..5113dc5048b 100644
--- a/tests/ui/rustc_public-ir-print/async-closure.stdout
+++ b/tests/ui/rustc_public-ir-print/async-closure.stdout
@@ -40,30 +40,28 @@ fn foo::{closure#0}::{closure#0}(_1: Pin<&mut {async closure body@$DIR/async-clo
     let  _3: i32;
     let mut _4: &i32;
     let mut _5: ();
-    let mut _6: &mut Context<'_>;
-    let mut _7: u32;
+    let mut _6: u32;
+    let mut _7: &mut {async closure body@$DIR/async-closure.rs:9:22: 11:6};
     let mut _8: &mut {async closure body@$DIR/async-closure.rs:9:22: 11:6};
     let mut _9: &mut {async closure body@$DIR/async-closure.rs:9:22: 11:6};
-    let mut _10: &mut {async closure body@$DIR/async-closure.rs:9:22: 11:6};
-    debug _task_context => _6;
+    debug _task_context => _2;
     debug y => (*((*(_1.0: &mut {async closure body@$DIR/async-closure.rs:9:22: 11:6})).0: &i32));
     debug y => _3;
     bb0: {
-        _8 = CopyForDeref((_1.0: &mut {async closure body@$DIR/async-closure.rs:9:22: 11:6}));
-        _7 = discriminant((*_8));
-        switchInt(move _7) -> [0: bb1, 1: bb2, otherwise: bb3];
+        _7 = CopyForDeref((_1.0: &mut {async closure body@$DIR/async-closure.rs:9:22: 11:6}));
+        _6 = discriminant((*_7));
+        switchInt(move _6) -> [0: bb1, 1: bb2, otherwise: bb3];
     }
     bb1: {
-        _6 = move _2;
         StorageLive(_3);
-        _9 = CopyForDeref((_1.0: &mut {async closure body@$DIR/async-closure.rs:9:22: 11:6}));
-        _4 = CopyForDeref(((*_9).0: &i32));
+        _8 = CopyForDeref((_1.0: &mut {async closure body@$DIR/async-closure.rs:9:22: 11:6}));
+        _4 = CopyForDeref(((*_8).0: &i32));
         _3 = (*_4);
         _5 = ();
         StorageDead(_3);
         _0 = std::task::Poll::Ready(move _5);
-        _10 = CopyForDeref((_1.0: &mut {async closure body@$DIR/async-closure.rs:9:22: 11:6}));
-        discriminant((*_10)) = 1;
+        _9 = CopyForDeref((_1.0: &mut {async closure body@$DIR/async-closure.rs:9:22: 11:6}));
+        discriminant((*_9)) = 1;
         return;
     }
     bb2: {
@@ -78,30 +76,28 @@ fn foo::{closure#0}::{synthetic#0}(_1: Pin<&mut {async closure body@$DIR/async-c
     let  _3: i32;
     let mut _4: &i32;
     let mut _5: ();
-    let mut _6: &mut Context<'_>;
-    let mut _7: u32;
+    let mut _6: u32;
+    let mut _7: &mut {async closure body@$DIR/async-closure.rs:9:22: 11:6};
     let mut _8: &mut {async closure body@$DIR/async-closure.rs:9:22: 11:6};
     let mut _9: &mut {async closure body@$DIR/async-closure.rs:9:22: 11:6};
-    let mut _10: &mut {async closure body@$DIR/async-closure.rs:9:22: 11:6};
-    debug _task_context => _6;
+    debug _task_context => _2;
     debug y => (*((*(_1.0: &mut {async closure body@$DIR/async-closure.rs:9:22: 11:6})).0: &i32));
     debug y => _3;
     bb0: {
-        _8 = CopyForDeref((_1.0: &mut {async closure body@$DIR/async-closure.rs:9:22: 11:6}));
-        _7 = discriminant((*_8));
-        switchInt(move _7) -> [0: bb1, 1: bb2, otherwise: bb3];
+        _7 = CopyForDeref((_1.0: &mut {async closure body@$DIR/async-closure.rs:9:22: 11:6}));
+        _6 = discriminant((*_7));
+        switchInt(move _6) -> [0: bb1, 1: bb2, otherwise: bb3];
     }
     bb1: {
-        _6 = move _2;
         StorageLive(_3);
-        _9 = CopyForDeref((_1.0: &mut {async closure body@$DIR/async-closure.rs:9:22: 11:6}));
-        _4 = CopyForDeref(((*_9).0: &i32));
+        _8 = CopyForDeref((_1.0: &mut {async closure body@$DIR/async-closure.rs:9:22: 11:6}));
+        _4 = CopyForDeref(((*_8).0: &i32));
         _3 = (*_4);
         _5 = ();
         StorageDead(_3);
         _0 = std::task::Poll::Ready(move _5);
-        _10 = CopyForDeref((_1.0: &mut {async closure body@$DIR/async-closure.rs:9:22: 11:6}));
-        discriminant((*_10)) = 1;
+        _9 = CopyForDeref((_1.0: &mut {async closure body@$DIR/async-closure.rs:9:22: 11:6}));
+        discriminant((*_9)) = 1;
         return;
     }
     bb2: {