Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

MIR: Fix value moved diagnose messages #46231

Merged
merged 1 commit into from
Nov 28, 2017
Merged

MIR: Fix value moved diagnose messages #46231

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
55 changes: 45 additions & 10 deletions src/librustc_mir/borrow_check.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -444,6 +444,34 @@ enum WriteKind {
Move,
}

#[derive(Copy, Clone)]
enum InitializationRequiringAction {
Update,
Borrow,
Use,
Assignment,
}

impl InitializationRequiringAction {
fn as_noun(self) -> &'static str {
match self {
InitializationRequiringAction::Update => "update",
InitializationRequiringAction::Borrow => "borrow",
InitializationRequiringAction::Use => "use",
InitializationRequiringAction::Assignment => "assign"
}
}

fn as_verb_in_past_tense(self) -> &'static str {
match self {
InitializationRequiringAction::Update => "updated",
InitializationRequiringAction::Borrow => "borrowed",
InitializationRequiringAction::Use => "used",
InitializationRequiringAction::Assignment => "assigned"
}
}
}

impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
/// Checks an access to the given lvalue to see if it is allowed. Examines the set of borrows
/// that are in scope, as well as which paths have been initialized, to ensure that (a) the
Expand Down Expand Up @@ -534,7 +562,8 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
// Write of P[i] or *P, or WriteAndRead of any P, requires P init'd.
match mode {
MutateMode::WriteAndRead => {
self.check_if_path_is_moved(context, "update", lvalue_span, flow_state);
self.check_if_path_is_moved(context, InitializationRequiringAction::Update,
lvalue_span, flow_state);
}
MutateMode::JustWrite => {
self.check_if_assigned_path_is_moved(context, lvalue_span, flow_state);
Expand All @@ -560,7 +589,8 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
BorrowKind::Mut => (Deep, Write(WriteKind::MutableBorrow(bk))),
};
self.access_lvalue(context, (lvalue, span), access_kind, flow_state);
self.check_if_path_is_moved(context, "borrow", (lvalue, span), flow_state);
self.check_if_path_is_moved(context, InitializationRequiringAction::Borrow,
(lvalue, span), flow_state);
}

Rvalue::Use(ref operand) |
Expand All @@ -579,7 +609,8 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
};
self.access_lvalue(
context, (lvalue, span), (Shallow(Some(af)), Read(ReadKind::Copy)), flow_state);
self.check_if_path_is_moved(context, "use", (lvalue, span), flow_state);
self.check_if_path_is_moved(context, InitializationRequiringAction::Use,
(lvalue, span), flow_state);
}

Rvalue::BinaryOp(_bin_op, ref operand1, ref operand2) |
Expand Down Expand Up @@ -680,7 +711,8 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
// skip this check in that case).
}
ConsumeKind::Consume => {
self.check_if_path_is_moved(context, "use", lvalue_span, flow_state);
self.check_if_path_is_moved(context, InitializationRequiringAction::Use,
lvalue_span, flow_state);
}
}
}
Expand Down Expand Up @@ -741,7 +773,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {

fn check_if_path_is_moved(&mut self,
context: Context,
desired_action: &str,
desired_action: InitializationRequiringAction,
lvalue_span: (&Lvalue<'tcx>, Span),
flow_state: &InProgress<'cx, 'gcx, 'tcx>) {
// FIXME: analogous code in check_loans first maps `lvalue` to
Expand Down Expand Up @@ -912,7 +944,8 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
// `base` to its base_path.

self.check_if_path_is_moved(
context, "assignment", (base, span), flow_state);
context, InitializationRequiringAction::Assignment,
(base, span), flow_state);

// (base initialized; no need to
// recur further)
Expand Down Expand Up @@ -1316,7 +1349,7 @@ mod prefixes {
impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
fn report_use_of_moved_or_uninitialized(&mut self,
_context: Context,
desired_action: &str,
desired_action: InitializationRequiringAction,
(lvalue, span): (&Lvalue<'tcx>, Span),
mpi: MovePathIndex,
curr_move_out: &IdxSetBuf<MoveOutIndex>) {
Expand All @@ -1326,7 +1359,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {

if mois.is_empty() {
self.tcx.cannot_act_on_uninitialized_variable(span,
desired_action,
desired_action.as_noun(),
&self.describe_lvalue(lvalue),
Origin::Mir)
.span_label(span, format!("use of possibly uninitialized `{}`",
Expand All @@ -1336,11 +1369,13 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
let msg = ""; //FIXME: add "partially " or "collaterally "

let mut err = self.tcx.cannot_act_on_moved_value(span,
desired_action,
desired_action.as_noun(),
msg,
&self.describe_lvalue(lvalue),
Origin::Mir);
err.span_label(span, format!("value {} here after move", desired_action));

err.span_label(span, format!("value {} here after move",
desired_action.as_verb_in_past_tense()));
for moi in mois {
let move_msg = ""; //FIXME: add " (into closure)"
let move_span = self.mir.source_info(self.move_data.moves[*moi].source).span;
Expand Down
2 changes: 1 addition & 1 deletion src/test/ui/borrowck/borrowck-reinit.stderr
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -14,7 +14,7 @@ error[E0382]: use of moved value: `x` (Mir)
17 | drop(x);
| - value moved here
18 | let _ = (1,x); //~ ERROR use of moved value: `x` (Ast)
| ^ value use here after move
| ^ value used here after move

error: aborting due to 2 previous errors