Account for method call and indexing when looking for inner-most path in expression

Author: estebank

compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs

@@ -77,7 +77,9 @@ impl<'tcx> BorrowExplanation<'tcx> {
                 if let Some(mut expr) = expr_finder.result {
                     while let hir::ExprKind::AddrOf(_, _, inner)
                         | hir::ExprKind::Unary(hir::UnOp::Deref, inner)
-                        | hir::ExprKind::Field(inner, _) = &expr.kind
+                        | hir::ExprKind::Field(inner, _)
+                        | hir::ExprKind::MethodCall(_, inner, _, _)
+                        | hir::ExprKind::Index(inner, _) = &expr.kind
                     {
                         expr = inner;
                     }

tests/ui/box/leak-alloc.stderr

@@ -1,6 +1,8 @@
 error[E0505]: cannot move out of `alloc` because it is borrowed
   --> $DIR/leak-alloc.rs:26:10
    |
+LL |     let alloc = Alloc {};
+   |         ----- binding `alloc` declared here
 LL |     let boxed = Box::new_in(10, alloc.by_ref());
    |                                 -------------- borrow of `alloc` occurs here
 LL |     let theref = Box::leak(boxed);

tests/ui/dropck/drop-with-active-borrows-1.stderr

@@ -1,6 +1,8 @@
 error[E0505]: cannot move out of `a` because it is borrowed
   --> $DIR/drop-with-active-borrows-1.rs:4:10
    |
+LL |     let a = "".to_string();
+   |         - binding `a` declared here
 LL |     let b: Vec<&str> = a.lines().collect();
    |                        --------- borrow of `a` occurs here
 LL |     drop(a);

tests/ui/generator/dropck.stderr

@@ -1,6 +1,9 @@
 error[E0597]: `*cell` does not live long enough
   --> $DIR/dropck.rs:10:40
    |
+LL |     let (mut gen, cell);
+   |                   ---- binding `cell` declared here
+LL |     cell = Box::new(RefCell::new(0));
 LL |     let ref_ = Box::leak(Box::new(Some(cell.borrow_mut())));
    |                                        ^^^^^^^^^^^^^^^^^ borrowed value does not live long enough
 ...

tests/ui/issues/issue-52126-assign-op-invariance.stderr

@@ -1,6 +1,8 @@
 error[E0597]: `line` does not live long enough
   --> $DIR/issue-52126-assign-op-invariance.rs:34:28
    |
+LL |     for line in vec!["123456789".to_string(), "12345678".to_string()] {
+   |         ---- binding `line` declared here
 LL |         let v: Vec<&str> = line.split_whitespace().collect();
    |                            ^^^^^^^^^^^^^^^^^^^^^^^ borrowed value does not live long enough
 ...

tests/ui/macros/format-args-temporaries-in-write.stderr

@@ -1,6 +1,8 @@
 error[E0597]: `mutex` does not live long enough
   --> $DIR/format-args-temporaries-in-write.rs:41:27
    |
+LL |         let mutex = Mutex;
+   |             ----- binding `mutex` declared here
 LL |         write!(Out, "{}", mutex.lock()) /* no semicolon */
    |                           ^^^^^^^^^^^^
    |                           |
@@ -16,6 +18,8 @@ LL |     };
 error[E0597]: `mutex` does not live long enough
   --> $DIR/format-args-temporaries-in-write.rs:47:29
    |
+LL |         let mutex = Mutex;
+   |             ----- binding `mutex` declared here
 LL |         writeln!(Out, "{}", mutex.lock()) /* no semicolon */
    |                             ^^^^^^^^^^^^
    |                             |

tests/ui/match/issue-74050-end-span.stderr

@@ -4,6 +4,7 @@ error[E0597]: `arg` does not live long enough
 LL |     let _arg = match args.next() {
    |         ---- borrow later stored here
 LL |         Some(arg) => {
+   |              --- binding `arg` declared here
 LL |             match arg.to_str() {
    |                   ^^^^^^^^^^^^ borrowed value does not live long enough
 ...

tests/ui/moves/move-fn-self-receiver.stderr

@@ -75,6 +75,8 @@ LL |     fn use_pin_box_self(self: Pin<Box<Self>>) {}
 error[E0505]: cannot move out of `mut_foo` because it is borrowed
   --> $DIR/move-fn-self-receiver.rs:50:5
    |
+LL |     let mut mut_foo = Foo;
+   |         ----------- binding `mut_foo` declared here
 LL |     let ret = mut_foo.use_mut_self();
    |               ---------------------- borrow of `mut_foo` occurs here
 LL |     mut_foo;

tests/ui/nll/issue-54556-niconii.stderr

@@ -1,6 +1,9 @@
 error[E0597]: `counter` does not live long enough
   --> $DIR/issue-54556-niconii.rs:22:20
    |
+LL |     let counter = Mutex;
+   |         ------- binding `counter` declared here
+LL |
 LL |     if let Ok(_) = counter.lock() { }
    |                    ^^^^^^^^^^^^^^
    |                    |

tests/ui/span/borrowck-let-suggestion-suffixes.rs

@@ -8,6 +8,7 @@ fn f() {
 
     {
         let young = ['y'];       // statement 3
+        //~^ NOTE binding `young` declared here
 
         v2.push(&young[0]);      // statement 4
         //~^ ERROR `young[_]` does not live long enough