diff --git a/src/librustc_mir/borrow_check.rs b/src/librustc_mir/borrow_check.rs index 063cbc77559..5133e528b09 100644 --- a/src/librustc_mir/borrow_check.rs +++ b/src/librustc_mir/borrow_check.rs @@ -419,7 +419,7 @@ impl<'c, 'b, 'a: 'b+'c, 'gcx, 'tcx: 'a> MirBorrowckCtxt<'c, 'b, 'a, 'gcx, 'tcx> self.each_borrow_involving_path( context, lvalue_span.0, flow_state, |this, _idx, borrow| { if !borrow.compatible_with(BorrowKind::Shared) { - this.report_use_while_mutably_borrowed(context, lvalue_span); + this.report_use_while_mutably_borrowed(context, lvalue_span, borrow); Control::Break } else { Control::Continue @@ -914,11 +914,17 @@ impl<'c, 'b, 'a: 'b+'c, 'gcx, 'tcx: 'a> MirBorrowckCtxt<'c, 'b, 'a, 'gcx, 'tcx> fn report_use_while_mutably_borrowed(&mut self, _context: Context, - (lvalue, span): (&Lvalue, Span)) { + (lvalue, span): (&Lvalue, Span), + borrow : &BorrowData) { + let described_lvalue = self.describe_lvalue(lvalue); + let borrow_span = self.retrieve_borrow_span(borrow); + let mut err = self.tcx.cannot_use_when_mutably_borrowed( - span, &self.describe_lvalue(lvalue), Origin::Mir); - // FIXME 1: add span_label for "borrow of `()` occurs here" - // FIXME 2: add span_label for "use of `{}` occurs here" + span, &described_lvalue, Origin::Mir); + + err.span_label(borrow_span, format!("borrow of `{}` occurs here", described_lvalue)); + err.span_label(span, format!("use of borrowed `{}`", described_lvalue)); + err.emit(); } @@ -998,7 +1004,7 @@ impl<'c, 'b, 'a: 'b+'c, 'gcx, 'tcx: 'a> MirBorrowckCtxt<'c, 'b, 'a, 'gcx, 'tcx> ProjectionElem::Downcast(..) => ("", format!(""), None), // (dont emit downcast info) ProjectionElem::Field(field, _ty) => - ("", format!(".{}", field.index()), None), + ("", format!(".{}", field.index()), None), // FIXME: report name of field ProjectionElem::Index(index) => ("", format!(""), Some(index)), ProjectionElem::ConstantIndex { offset, min_length, from_end: true } => @@ -1024,6 +1030,13 @@ impl<'c, 'b, 'a: 'b+'c, 'gcx, 'tcx: 'a> MirBorrowckCtxt<'c, 'b, 'a, 'gcx, 'tcx> } } } + + // Retrieve span of given borrow from the current MIR representation + fn retrieve_borrow_span(&self, borrow: &BorrowData) -> Span { + self.mir.basic_blocks()[borrow.location.block] + .statements[borrow.location.statement_index] + .source_info.span + } } impl<'c, 'b, 'a: 'b+'c, 'gcx, 'tcx: 'a> MirBorrowckCtxt<'c, 'b, 'a, 'gcx, 'tcx> {