Rollup merge of #81158 - 1000teslas:issue-80313-fix, r=Aaron1011

Point to span of upvar making closure FnMut

For #80313.

src/test/ui/borrowck/borrow-raw-address-of-mutability.stderr

@@ -20,7 +20,9 @@ error[E0596]: cannot borrow `f` as mutable, as it is not declared as mutable
    |
 LL |     let f = || {
    |         - help: consider changing this to be mutable: `mut f`
-...
+LL |         let y = &raw mut x;
+   |                          - calling `f` requires mutable binding due to mutable borrow of `x`
+LL |     };
 LL |     f();
    |     ^ cannot borrow as mutable
 

src/test/ui/closures/issue-80313-mutable-borrow-in-closure.rs

@@ -0,0 +1,7 @@
+fn main() {
+    let mut my_var = false;
+    let callback = || {
+        &mut my_var;
+    };
+    callback(); //~ ERROR E0596
+}

src/test/ui/closures/issue-80313-mutable-borrow-in-closure.stderr

@@ -0,0 +1,14 @@
+error[E0596]: cannot borrow `callback` as mutable, as it is not declared as mutable
+  --> $DIR/issue-80313-mutable-borrow-in-closure.rs:6:5
+   |
+LL |     let callback = || {
+   |         -------- help: consider changing this to be mutable: `mut callback`
+LL |         &mut my_var;
+   |              ------ calling `callback` requires mutable binding due to mutable borrow of `my_var`
+LL |     };
+LL |     callback();
+   |     ^^^^^^^^ cannot borrow as mutable
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0596`.

src/test/ui/closures/issue-80313-mutable-borrow-in-move-closure.rs

@@ -0,0 +1,7 @@
+fn main() {
+    let mut my_var = false;
+    let callback = move || {
+        &mut my_var;
+    };
+    callback(); //~ ERROR E0596
+}

src/test/ui/closures/issue-80313-mutable-borrow-in-move-closure.stderr

@@ -0,0 +1,14 @@
+error[E0596]: cannot borrow `callback` as mutable, as it is not declared as mutable
+  --> $DIR/issue-80313-mutable-borrow-in-move-closure.rs:6:5
+   |
+LL |     let callback = move || {
+   |         -------- help: consider changing this to be mutable: `mut callback`
+LL |         &mut my_var;
+   |              ------ calling `callback` requires mutable binding due to possible mutation of `my_var`
+LL |     };
+LL |     callback();
+   |     ^^^^^^^^ cannot borrow as mutable
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0596`.

src/test/ui/closures/issue-80313-mutation-in-closure.rs

@@ -0,0 +1,7 @@
+fn main() {
+    let mut my_var = false;
+    let callback = || {
+        my_var = true;
+    };
+    callback(); //~ ERROR E0596
+}

src/test/ui/closures/issue-80313-mutation-in-closure.stderr

@@ -0,0 +1,14 @@
+error[E0596]: cannot borrow `callback` as mutable, as it is not declared as mutable
+  --> $DIR/issue-80313-mutation-in-closure.rs:6:5
+   |
+LL |     let callback = || {
+   |         -------- help: consider changing this to be mutable: `mut callback`
+LL |         my_var = true;
+   |         ------ calling `callback` requires mutable binding due to mutable borrow of `my_var`
+LL |     };
+LL |     callback();
+   |     ^^^^^^^^ cannot borrow as mutable
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0596`.

src/test/ui/closures/issue-80313-mutation-in-move-closure.rs

@@ -0,0 +1,7 @@
+fn main() {
+    let mut my_var = false;
+    let callback = move || {
+        my_var = true;
+    };
+    callback(); //~ ERROR E0596
+}

src/test/ui/closures/issue-80313-mutation-in-move-closure.stderr

@@ -0,0 +1,14 @@
+error[E0596]: cannot borrow `callback` as mutable, as it is not declared as mutable
+  --> $DIR/issue-80313-mutation-in-move-closure.rs:6:5
+   |
+LL |     let callback = move || {
+   |         -------- help: consider changing this to be mutable: `mut callback`
+LL |         my_var = true;
+   |         ------ calling `callback` requires mutable binding due to possible mutation of `my_var`
+LL |     };
+LL |     callback();
+   |     ^^^^^^^^ cannot borrow as mutable
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0596`.

src/test/ui/unboxed-closures/unboxed-closures-infer-fnmut-calling-fnmut-no-mut.stderr

@@ -3,6 +3,8 @@ error[E0596]: cannot borrow `tick1` as mutable, as it is not declared as mutable
    |
 LL |     let tick1 = || {
    |         ----- help: consider changing this to be mutable: `mut tick1`
+LL |         counter += 1;
+   |         ------- calling `tick1` requires mutable binding due to mutable borrow of `counter`
 ...
 LL |         tick1();
    |         ^^^^^ cannot borrow as mutable
@@ -12,6 +14,8 @@ error[E0596]: cannot borrow `tick2` as mutable, as it is not declared as mutable
    |
 LL |     let tick2 = || {
    |         ----- help: consider changing this to be mutable: `mut tick2`
+LL |         tick1();
+   |         ----- calling `tick2` requires mutable binding due to mutable borrow of `tick1`
 ...
 LL |     tick2();
    |     ^^^^^ cannot borrow as mutable

src/test/ui/unboxed-closures/unboxed-closures-infer-fnmut-missing-mut.stderr

@@ -2,7 +2,9 @@ error[E0596]: cannot borrow `tick` as mutable, as it is not declared as mutable
   --> $DIR/unboxed-closures-infer-fnmut-missing-mut.rs:7:5
    |
 LL |     let tick = || counter += 1;
-   |         ---- help: consider changing this to be mutable: `mut tick`
+   |         ----      ------- calling `tick` requires mutable binding due to mutable borrow of `counter`
+   |         |
+   |         help: consider changing this to be mutable: `mut tick`
 LL |     tick();
    |     ^^^^ cannot borrow as mutable
 

src/test/ui/unboxed-closures/unboxed-closures-infer-fnmut-move-missing-mut.stderr

@@ -2,7 +2,9 @@ error[E0596]: cannot borrow `tick` as mutable, as it is not declared as mutable
   --> $DIR/unboxed-closures-infer-fnmut-move-missing-mut.rs:7:5
    |
 LL |     let tick = move || counter += 1;
-   |         ---- help: consider changing this to be mutable: `mut tick`
+   |         ----           ------- calling `tick` requires mutable binding due to possible mutation of `counter`
+   |         |
+   |         help: consider changing this to be mutable: `mut tick`
 LL |     tick();
    |     ^^^^ cannot borrow as mutable