diff --git a/src/librustc_borrowck/borrowck/check_loans.rs b/src/librustc_borrowck/borrowck/check_loans.rs
index a802729e3fbdb..e47e95afb1643 100644
--- a/src/librustc_borrowck/borrowck/check_loans.rs
+++ b/src/librustc_borrowck/borrowck/check_loans.rs
@@ -615,7 +615,7 @@ impl<'a, 'tcx> CheckLoanCtxt<'a, 'tcx> {
let new_loan_str = &new_loan.kind.to_user_str();
self.bccx.cannot_reborrow_already_uniquely_borrowed(
new_loan.span, "closure", &nl, &new_loan_msg, new_loan_str,
- old_loan.span, &old_loan_msg, previous_end_span, Origin::Ast)
+ old_loan.span, &old_loan_msg, previous_end_span, "", Origin::Ast)
}
(..) =>
self.bccx.cannot_reborrow_already_borrowed(
diff --git a/src/librustc_mir/borrow_check/error_reporting.rs b/src/librustc_mir/borrow_check/error_reporting.rs
index 4ccd26bee8b88..ba26ed36c20f4 100644
--- a/src/librustc_mir/borrow_check/error_reporting.rs
+++ b/src/librustc_mir/borrow_check/error_reporting.rs
@@ -344,6 +344,13 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
let first_borrow_desc;
+ let explanation = self.explain_why_borrow_contains_point(context, issued_borrow, None);
+ let second_borrow_desc = if explanation.is_explained() {
+ "second "
+ } else {
+ ""
+ };
+
// FIXME: supply non-"" `opt_via` when appropriate
let mut err = match (
gen_borrow_kind,
@@ -454,6 +461,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
issued_span,
"",
None,
+ second_borrow_desc,
Origin::Mir,
)
}
@@ -469,6 +477,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
issued_span,
"",
None,
+ second_borrow_desc,
Origin::Mir,
)
}
@@ -513,7 +522,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
);
}
- self.explain_why_borrow_contains_point(context, issued_borrow, None)
+ explanation
.add_explanation_to_diagnostic(self.infcx.tcx, self.mir, &mut err, first_borrow_desc);
err.buffer(&mut self.errors_buffer);
diff --git a/src/librustc_mir/borrow_check/nll/explain_borrow/mod.rs b/src/librustc_mir/borrow_check/nll/explain_borrow/mod.rs
index bb9a29b055b7f..477b78926084e 100644
--- a/src/librustc_mir/borrow_check/nll/explain_borrow/mod.rs
+++ b/src/librustc_mir/borrow_check/nll/explain_borrow/mod.rs
@@ -52,6 +52,12 @@ pub(in borrow_check) enum LaterUseKind {
}
impl BorrowExplanation {
+ pub(in borrow_check) fn is_explained(&self) -> bool {
+ match self {
+ BorrowExplanation::Unexplained => false,
+ _ => true,
+ }
+ }
pub(in borrow_check) fn add_explanation_to_diagnostic<'cx, 'gcx, 'tcx>(
&self,
tcx: TyCtxt<'cx, 'gcx, 'tcx>,
diff --git a/src/librustc_mir/util/borrowck_errors.rs b/src/librustc_mir/util/borrowck_errors.rs
index ae0483e3c140c..8566f845f23e3 100644
--- a/src/librustc_mir/util/borrowck_errors.rs
+++ b/src/librustc_mir/util/borrowck_errors.rs
@@ -261,6 +261,7 @@ pub trait BorrowckErrors<'cx>: Sized + Copy {
old_loan_span: Span,
old_opt_via: &str,
previous_end_span: Option<Span>,
+ second_borrow_desc: &str,
o: Origin,
) -> DiagnosticBuilder<'cx> {
let mut err = struct_span_err!(
@@ -274,7 +275,10 @@ pub trait BorrowckErrors<'cx>: Sized + Copy {
kind_new,
OGN = o
);
- err.span_label(new_loan_span, format!("borrow occurs here{}", opt_via));
+ err.span_label(
+ new_loan_span,
+ format!("{}borrow occurs here{}", second_borrow_desc, opt_via),
+ );
err.span_label(
old_loan_span,
format!("{} construction occurs here{}", container_name, old_opt_via),
diff --git a/src/test/ui/E0501.ast.nll.stderr b/src/test/ui/E0501.ast.nll.stderr
index 72fda9079d636..8a3fce3a554eb 100644
--- a/src/test/ui/E0501.ast.nll.stderr
+++ b/src/test/ui/E0501.ast.nll.stderr
@@ -7,7 +7,7 @@ LL | inside_closure(a)
| - first borrow occurs due to use of `a` in closure
LL | };
LL | outside_closure_1(a); //[ast]~ ERROR cannot borrow `*a` as mutable because previous closure requires unique access
- | ^ borrow occurs here
+ | ^ second borrow occurs here
...
LL | drop(bar);
| --- first borrow later used here
@@ -21,7 +21,7 @@ LL | inside_closure(a)
| - first borrow occurs due to use of `a` in closure
...
LL | outside_closure_2(a); //[ast]~ ERROR cannot borrow `*a` as immutable because previous closure requires unique access
- | ^ borrow occurs here
+ | ^ second borrow occurs here
...
LL | drop(bar);
| --- first borrow later used here
diff --git a/src/test/ui/E0501.mir.stderr b/src/test/ui/E0501.mir.stderr
index 72fda9079d636..8a3fce3a554eb 100644
--- a/src/test/ui/E0501.mir.stderr
+++ b/src/test/ui/E0501.mir.stderr
@@ -7,7 +7,7 @@ LL | inside_closure(a)
| - first borrow occurs due to use of `a` in closure
LL | };
LL | outside_closure_1(a); //[ast]~ ERROR cannot borrow `*a` as mutable because previous closure requires unique access
- | ^ borrow occurs here
+ | ^ second borrow occurs here
...
LL | drop(bar);
| --- first borrow later used here
@@ -21,7 +21,7 @@ LL | inside_closure(a)
| - first borrow occurs due to use of `a` in closure
...
LL | outside_closure_2(a); //[ast]~ ERROR cannot borrow `*a` as immutable because previous closure requires unique access
- | ^ borrow occurs here
+ | ^ second borrow occurs here
...
LL | drop(bar);
| --- first borrow later used here
diff --git a/src/test/ui/borrowck/borrowck-insert-during-each.nll.stderr b/src/test/ui/borrowck/borrowck-insert-during-each.nll.stderr
index 123d475f1c09f..84fc69465cb4a 100644
--- a/src/test/ui/borrowck/borrowck-insert-during-each.nll.stderr
+++ b/src/test/ui/borrowck/borrowck-insert-during-each.nll.stderr
@@ -10,7 +10,7 @@ LL | | |a| { //~ ERROR closure requires unique access to `f`
LL | | f.n.insert(*a);
| | - first borrow occurs due to use of `f` in closure
LL | | })
- | |__________^ borrow occurs here
+ | |__________^ second borrow occurs here
error[E0500]: closure requires unique access to `f` but it is already borrowed
--> $DIR/borrowck-insert-during-each.rs:27:9
diff --git a/src/test/ui/generator/yield-while-ref-reborrowed.nll.stderr b/src/test/ui/generator/yield-while-ref-reborrowed.nll.stderr
index 8dabb3c2505b6..60163d78e78f9 100644
--- a/src/test/ui/generator/yield-while-ref-reborrowed.nll.stderr
+++ b/src/test/ui/generator/yield-while-ref-reborrowed.nll.stderr
@@ -7,7 +7,7 @@ LL | let a = &mut *x;
| - first borrow occurs due to use of `x` in generator
...
LL | println!("{}", x); //~ ERROR
- | ^ borrow occurs here
+ | ^ second borrow occurs here
LL | b.resume();
| - first borrow later used here
diff --git a/src/test/ui/nll/closure-borrow-spans.stderr b/src/test/ui/nll/closure-borrow-spans.stderr
index 3e423dadd192c..98a261657b1e7 100644
--- a/src/test/ui/nll/closure-borrow-spans.stderr
+++ b/src/test/ui/nll/closure-borrow-spans.stderr
@@ -126,7 +126,7 @@ LL | let f = || *x = 0;
| |
| closure construction occurs here
LL | let y = &x; //~ ERROR
- | ^^ borrow occurs here
+ | ^^ second borrow occurs here
LL | f.use_ref();
| - first borrow later used here
@@ -138,7 +138,7 @@ LL | let f = || *x = 0;
| |
| closure construction occurs here
LL | let y = &mut x; //~ ERROR
- | ^^^^^^ borrow occurs here
+ | ^^^^^^ second borrow occurs here
LL | f.use_ref();
| - first borrow later used here