diff options
| -rw-r--r-- | src/librustc_borrowck/borrowck/mod.rs | 2 | ||||
| -rw-r--r-- | src/librustc_mir/borrow_check/mod.rs | 39 | ||||
| -rw-r--r-- | src/librustc_mir/util/borrowck_errors.rs | 14 | ||||
| -rw-r--r-- | src/test/compile-fail/borrowck/borrowck-issue-14498.rs | 2 | ||||
| -rw-r--r-- | src/test/compile-fail/borrowck/borrowck-overloaded-index-ref-index.rs | 2 | ||||
| -rw-r--r-- | src/test/ui/nll/issue-47388.stderr | 4 |
6 files changed, 35 insertions, 28 deletions
diff --git a/src/librustc_borrowck/borrowck/mod.rs b/src/librustc_borrowck/borrowck/mod.rs index 6e8ebce8415..93d6247eeae 100644 --- a/src/librustc_borrowck/borrowck/mod.rs +++ b/src/librustc_borrowck/borrowck/mod.rs @@ -839,7 +839,7 @@ impl<'a, 'tcx> BorrowckCtxt<'a, 'tcx> { let mut db = match err.cause { MutabilityViolation => { - let mut db = self.cannot_assign(error_span, &descr, Origin::Ast, false); + let mut db = self.cannot_assign(error_span, &descr, Origin::Ast); if let mc::NoteClosureEnv(upvar_id) = err.cmt.note { let node_id = self.tcx.hir.hir_to_node_id(upvar_id.var_id); let sp = self.tcx.hir.span(node_id); diff --git a/src/librustc_mir/borrow_check/mod.rs b/src/librustc_mir/borrow_check/mod.rs index 0f529c77aea..db7427ddae5 100644 --- a/src/librustc_mir/borrow_check/mod.rs +++ b/src/librustc_mir/borrow_check/mod.rs @@ -1506,20 +1506,35 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> { } fn specialized_description(&self, place:&Place<'tcx>) -> Option<String>{ - if let Some(name) = self.describe_place(place) { - Some(format!("`&`-reference `{}`", name)) + if let Some(_name) = self.describe_place(place) { + Some(format!("data in a `&` reference")) } else { None } } - fn get_main_error_message(&self, place:&Place<'tcx>) -> String{ + fn get_default_err_msg(&self, place:&Place<'tcx>) -> String{ match self.describe_place(place) { Some(name) => format!("immutable item `{}`", name), None => "immutable item".to_owned(), } } + fn get_secondary_err_msg(&self, place:&Place<'tcx>) -> String{ + match self.specialized_description(place) { + Some(_) => format!("data in a `&` reference"), + None => self.get_default_err_msg(place) + } + } + + fn get_primary_err_msg(&self, place:&Place<'tcx>) -> String{ + if let Some(name) = self.describe_place(place) { + format!("`{}` is a `&` reference, so the data it refers to cannot be written", name) + } else { + format!("cannot assign through `&`-reference") + } + } + /// Check the permissions for the given place and read or write kind /// /// Returns true if an error is reported, false otherwise. @@ -1546,7 +1561,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> { self.is_mutable(place, is_local_mutation_allowed) { error_reported = true; - let item_msg = self.get_main_error_message(place); + let item_msg = self.get_default_err_msg(place); let mut err = self.tcx .cannot_borrow_path_as_mutable(span, &item_msg, Origin::Mir); err.span_label(span, "cannot borrow as mutable"); @@ -1576,18 +1591,16 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> { let locations = self.mir.find_assignments(local); if locations.len() > 0 { let item_msg = if error_reported { - match self.specialized_description(base){ - Some(msg) => msg, - None => self.get_main_error_message(place) - } + self.get_secondary_err_msg(base) } else { - self.get_main_error_message(place) + self.get_default_err_msg(place) }; + err_info = Some(( self.mir.source_info(locations[0]).span, "consider changing this to be a \ mutable reference: `&mut`", item_msg, - "cannot assign through `&`-reference")); + self.get_primary_err_msg(base))); } }, _ => {}, @@ -1597,15 +1610,15 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> { } if let Some((err_help_span, err_help_stmt, item_msg, sec_span)) = err_info { - let mut err = self.tcx.cannot_assign(span, &item_msg, Origin::Mir, true); + let mut err = self.tcx.cannot_assign(span, &item_msg, Origin::Mir); err.span_suggestion(err_help_span, err_help_stmt, format!("")); if place != place_err { err.span_label(span, sec_span); } err.emit() } else { - let item_msg_ = self.get_main_error_message(place); - let mut err = self.tcx.cannot_assign(span, &item_msg_, Origin::Mir, false); + let item_msg_ = self.get_default_err_msg(place); + let mut err = self.tcx.cannot_assign(span, &item_msg_, Origin::Mir); err.span_label(span, "cannot mutate"); if place != place_err { if let Some(name) = self.describe_place(place_err) { diff --git a/src/librustc_mir/util/borrowck_errors.rs b/src/librustc_mir/util/borrowck_errors.rs index bcb3b605450..d6b3e674f8f 100644 --- a/src/librustc_mir/util/borrowck_errors.rs +++ b/src/librustc_mir/util/borrowck_errors.rs @@ -284,25 +284,19 @@ pub trait BorrowckErrors<'cx>: Sized + Copy { self.cancel_if_wrong_origin(err, o) } - fn cannot_assign(self, span: Span, desc: &str, o: Origin, is_reference: bool) + fn cannot_assign(self, span: Span, desc: &str, o: Origin) -> DiagnosticBuilder<'cx> { - let msg = if is_reference { - "through" - } else { - "to" - }; - let err = struct_span_err!(self, span, E0594, - "cannot assign {} {}{OGN}", - msg, desc, OGN=o); + "cannot assign to {}{OGN}", + desc, OGN=o); self.cancel_if_wrong_origin(err, o) } fn cannot_assign_static(self, span: Span, desc: &str, o: Origin) -> DiagnosticBuilder<'cx> { - self.cannot_assign(span, &format!("immutable static item `{}`", desc), o, false) + self.cannot_assign(span, &format!("immutable static item `{}`", desc), o) } fn cannot_move_out_of(self, move_from_span: Span, move_from_desc: &str, o: Origin) diff --git a/src/test/compile-fail/borrowck/borrowck-issue-14498.rs b/src/test/compile-fail/borrowck/borrowck-issue-14498.rs index f70e2b4816b..fbdd013024d 100644 --- a/src/test/compile-fail/borrowck/borrowck-issue-14498.rs +++ b/src/test/compile-fail/borrowck/borrowck-issue-14498.rs @@ -27,7 +27,7 @@ fn indirect_write_to_imm_box() { let y: Box<_> = box &mut x; let p = &y; ***p = 2; //[ast]~ ERROR cannot assign to data in a `&` reference - //[mir]~^ ERROR cannot assign through `&`-reference `p` + //[mir]~^ ERROR cannot assign to data in a `&` reference drop(p); } diff --git a/src/test/compile-fail/borrowck/borrowck-overloaded-index-ref-index.rs b/src/test/compile-fail/borrowck/borrowck-overloaded-index-ref-index.rs index 86abd114d6a..3a4c22eb139 100644 --- a/src/test/compile-fail/borrowck/borrowck-overloaded-index-ref-index.rs +++ b/src/test/compile-fail/borrowck/borrowck-overloaded-index-ref-index.rs @@ -70,5 +70,5 @@ fn main() { }; s[2] = 20; //[ast]~^ ERROR cannot assign to immutable indexed content - //[mir]~^^ ERROR cannot assign through immutable item + //[mir]~^^ ERROR cannot assign to immutable item } diff --git a/src/test/ui/nll/issue-47388.stderr b/src/test/ui/nll/issue-47388.stderr index ae6d8d7a598..272cb6510aa 100644 --- a/src/test/ui/nll/issue-47388.stderr +++ b/src/test/ui/nll/issue-47388.stderr @@ -1,10 +1,10 @@ -error[E0594]: cannot assign through `&`-reference `fancy_ref` +error[E0594]: cannot assign to data in a `&` reference --> $DIR/issue-47388.rs:18:5 | LL | let fancy_ref = &(&mut fancy); | ------------- help: consider changing this to be a mutable reference: `&mut` LL | fancy_ref.num = 6; //~ ERROR E0594 - | ^^^^^^^^^^^^^^^^^ cannot assign through `&`-reference + | ^^^^^^^^^^^^^^^^^ `fancy_ref` is a `&` reference, so the data it refers to cannot be written error: aborting due to previous error |