rust/compiler/rustc_borrowck/src/borrowck_errors.rs
2022-11-09 21:15:31 +08:00

496 lines
15 KiB
Rust

use rustc_errors::{
struct_span_err, DiagnosticBuilder, DiagnosticId, DiagnosticMessage, ErrorGuaranteed, MultiSpan,
};
use rustc_middle::ty::{self, Ty, TyCtxt};
use rustc_span::Span;
impl<'cx, 'tcx> crate::MirBorrowckCtxt<'cx, 'tcx> {
pub(crate) fn cannot_move_when_borrowed(
&self,
span: Span,
borrow_span: Span,
place: &str,
borrow_place: &str,
value_place: &str,
) -> DiagnosticBuilder<'cx, ErrorGuaranteed> {
self.infcx.tcx.sess.create_err(crate::session_diagnostics::MoveBorrow {
place,
span,
borrow_place,
value_place,
borrow_span,
})
}
pub(crate) fn cannot_use_when_mutably_borrowed(
&self,
span: Span,
desc: &str,
borrow_span: Span,
borrow_desc: &str,
) -> DiagnosticBuilder<'cx, ErrorGuaranteed> {
let mut err = struct_span_err!(
self,
span,
E0503,
"cannot use {} because it was mutably borrowed",
desc,
);
err.span_label(borrow_span, format!("borrow of {} occurs here", borrow_desc));
err.span_label(span, format!("use of borrowed {}", borrow_desc));
err
}
pub(crate) fn cannot_mutably_borrow_multiply(
&self,
new_loan_span: Span,
desc: &str,
opt_via: &str,
old_loan_span: Span,
old_opt_via: &str,
old_load_end_span: Option<Span>,
) -> DiagnosticBuilder<'cx, ErrorGuaranteed> {
let via =
|msg: &str| if msg.is_empty() { "".to_string() } else { format!(" (via {})", msg) };
let mut err = struct_span_err!(
self,
new_loan_span,
E0499,
"cannot borrow {}{} as mutable more than once at a time",
desc,
via(opt_via),
);
if old_loan_span == new_loan_span {
// Both borrows are happening in the same place
// Meaning the borrow is occurring in a loop
err.span_label(
new_loan_span,
format!(
"{}{} was mutably borrowed here in the previous iteration of the loop{}",
desc,
via(opt_via),
opt_via,
),
);
if let Some(old_load_end_span) = old_load_end_span {
err.span_label(old_load_end_span, "mutable borrow ends here");
}
} else {
err.span_label(
old_loan_span,
format!("first mutable borrow occurs here{}", via(old_opt_via)),
);
err.span_label(
new_loan_span,
format!("second mutable borrow occurs here{}", via(opt_via)),
);
if let Some(old_load_end_span) = old_load_end_span {
err.span_label(old_load_end_span, "first borrow ends here");
}
}
err
}
pub(crate) fn cannot_uniquely_borrow_by_two_closures(
&self,
new_loan_span: Span,
desc: &str,
old_loan_span: Span,
old_load_end_span: Option<Span>,
) -> DiagnosticBuilder<'cx, ErrorGuaranteed> {
let mut err = struct_span_err!(
self,
new_loan_span,
E0524,
"two closures require unique access to {} at the same time",
desc,
);
if old_loan_span == new_loan_span {
err.span_label(
old_loan_span,
"closures are constructed here in different iterations of loop",
);
} else {
err.span_label(old_loan_span, "first closure is constructed here");
err.span_label(new_loan_span, "second closure is constructed here");
}
if let Some(old_load_end_span) = old_load_end_span {
err.span_label(old_load_end_span, "borrow from first closure ends here");
}
err
}
pub(crate) fn cannot_uniquely_borrow_by_one_closure(
&self,
new_loan_span: Span,
container_name: &str,
desc_new: &str,
opt_via: &str,
old_loan_span: Span,
noun_old: &str,
old_opt_via: &str,
previous_end_span: Option<Span>,
) -> DiagnosticBuilder<'cx, ErrorGuaranteed> {
let mut err = struct_span_err!(
self,
new_loan_span,
E0500,
"closure requires unique access to {} but {} is already borrowed{}",
desc_new,
noun_old,
old_opt_via,
);
err.span_label(
new_loan_span,
format!("{} construction occurs here{}", container_name, opt_via),
);
err.span_label(old_loan_span, format!("borrow occurs here{}", old_opt_via));
if let Some(previous_end_span) = previous_end_span {
err.span_label(previous_end_span, "borrow ends here");
}
err
}
pub(crate) fn cannot_reborrow_already_uniquely_borrowed(
&self,
new_loan_span: Span,
container_name: &str,
desc_new: &str,
opt_via: &str,
kind_new: &str,
old_loan_span: Span,
old_opt_via: &str,
previous_end_span: Option<Span>,
second_borrow_desc: &str,
) -> DiagnosticBuilder<'cx, ErrorGuaranteed> {
let mut err = struct_span_err!(
self,
new_loan_span,
E0501,
"cannot borrow {}{} as {} because previous closure requires unique access",
desc_new,
opt_via,
kind_new,
);
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),
);
if let Some(previous_end_span) = previous_end_span {
err.span_label(previous_end_span, "borrow from closure ends here");
}
err
}
pub(crate) fn cannot_reborrow_already_borrowed(
&self,
span: Span,
desc_new: &str,
msg_new: &str,
kind_new: &str,
old_span: Span,
noun_old: &str,
kind_old: &str,
msg_old: &str,
old_load_end_span: Option<Span>,
) -> DiagnosticBuilder<'cx, ErrorGuaranteed> {
let via =
|msg: &str| if msg.is_empty() { "".to_string() } else { format!(" (via {})", msg) };
let mut err = struct_span_err!(
self,
span,
E0502,
"cannot borrow {}{} as {} because {} is also borrowed as {}{}",
desc_new,
via(msg_new),
kind_new,
noun_old,
kind_old,
via(msg_old),
);
if msg_new == "" {
// If `msg_new` is empty, then this isn't a borrow of a union field.
err.span_label(span, format!("{} borrow occurs here", kind_new));
err.span_label(old_span, format!("{} borrow occurs here", kind_old));
} else {
// If `msg_new` isn't empty, then this a borrow of a union field.
err.span_label(
span,
format!(
"{} borrow of {} -- which overlaps with {} -- occurs here",
kind_new, msg_new, msg_old,
),
);
err.span_label(old_span, format!("{} borrow occurs here{}", kind_old, via(msg_old)));
}
if let Some(old_load_end_span) = old_load_end_span {
err.span_label(old_load_end_span, format!("{} borrow ends here", kind_old));
}
err
}
pub(crate) fn cannot_assign_to_borrowed(
&self,
span: Span,
borrow_span: Span,
desc: &str,
) -> DiagnosticBuilder<'cx, ErrorGuaranteed> {
let mut err = struct_span_err!(
self,
span,
E0506,
"cannot assign to {} because it is borrowed",
desc,
);
err.span_label(borrow_span, format!("borrow of {} occurs here", desc));
err.span_label(span, format!("assignment to borrowed {} occurs here", desc));
err
}
pub(crate) fn cannot_reassign_immutable(
&self,
span: Span,
desc: &str,
is_arg: bool,
) -> DiagnosticBuilder<'cx, ErrorGuaranteed> {
let msg = if is_arg { "to immutable argument" } else { "twice to immutable variable" };
struct_span_err!(self, span, E0384, "cannot assign {} {}", msg, desc)
}
pub(crate) fn cannot_assign(
&self,
span: Span,
desc: &str,
) -> DiagnosticBuilder<'cx, ErrorGuaranteed> {
struct_span_err!(self, span, E0594, "cannot assign to {}", desc)
}
pub(crate) fn cannot_move_out_of(
&self,
move_from_span: Span,
move_from_desc: &str,
) -> DiagnosticBuilder<'cx, ErrorGuaranteed> {
struct_span_err!(self, move_from_span, E0507, "cannot move out of {}", move_from_desc,)
}
/// Signal an error due to an attempt to move out of the interior
/// of an array or slice. `is_index` is None when error origin
/// didn't capture whether there was an indexing operation or not.
pub(crate) fn cannot_move_out_of_interior_noncopy(
&self,
move_from_span: Span,
ty: Ty<'_>,
is_index: Option<bool>,
) -> DiagnosticBuilder<'cx, ErrorGuaranteed> {
let type_name = match (&ty.kind(), is_index) {
(&ty::Array(_, _), Some(true)) | (&ty::Array(_, _), None) => "array",
(&ty::Slice(_), _) => "slice",
_ => span_bug!(move_from_span, "this path should not cause illegal move"),
};
let mut err = struct_span_err!(
self,
move_from_span,
E0508,
"cannot move out of type `{}`, a non-copy {}",
ty,
type_name,
);
err.span_label(move_from_span, "cannot move out of here");
err
}
pub(crate) fn cannot_move_out_of_interior_of_drop(
&self,
move_from_span: Span,
container_ty: Ty<'_>,
) -> DiagnosticBuilder<'cx, ErrorGuaranteed> {
let mut err = struct_span_err!(
self,
move_from_span,
E0509,
"cannot move out of type `{}`, which implements the `Drop` trait",
container_ty,
);
err.span_label(move_from_span, "cannot move out of here");
err
}
pub(crate) fn cannot_act_on_moved_value(
&self,
use_span: Span,
verb: &str,
optional_adverb_for_moved: &str,
moved_path: Option<String>,
) -> DiagnosticBuilder<'tcx, ErrorGuaranteed> {
let moved_path = moved_path.map(|mp| format!(": `{}`", mp)).unwrap_or_default();
struct_span_err!(
self,
use_span,
E0382,
"{} of {}moved value{}",
verb,
optional_adverb_for_moved,
moved_path,
)
}
pub(crate) fn cannot_borrow_path_as_mutable_because(
&self,
span: Span,
path: &str,
reason: &str,
) -> DiagnosticBuilder<'cx, ErrorGuaranteed> {
struct_span_err!(self, span, E0596, "cannot borrow {} as mutable{}", path, reason,)
}
pub(crate) fn cannot_mutate_in_immutable_section(
&self,
mutate_span: Span,
immutable_span: Span,
immutable_place: &str,
immutable_section: &str,
action: &str,
) -> DiagnosticBuilder<'cx, ErrorGuaranteed> {
let mut err = struct_span_err!(
self,
mutate_span,
E0510,
"cannot {} {} in {}",
action,
immutable_place,
immutable_section,
);
err.span_label(mutate_span, format!("cannot {}", action));
err.span_label(immutable_span, format!("value is immutable in {}", immutable_section));
err
}
pub(crate) fn cannot_borrow_across_generator_yield(
&self,
span: Span,
yield_span: Span,
) -> DiagnosticBuilder<'cx, ErrorGuaranteed> {
let mut err = struct_span_err!(
self,
span,
E0626,
"borrow may still be in use when generator yields",
);
err.span_label(yield_span, "possible yield occurs here");
err
}
pub(crate) fn cannot_borrow_across_destructor(
&self,
borrow_span: Span,
) -> DiagnosticBuilder<'cx, ErrorGuaranteed> {
struct_span_err!(
self,
borrow_span,
E0713,
"borrow may still be in use when destructor runs",
)
}
pub(crate) fn path_does_not_live_long_enough(
&self,
span: Span,
path: &str,
) -> DiagnosticBuilder<'cx, ErrorGuaranteed> {
struct_span_err!(self, span, E0597, "{} does not live long enough", path,)
}
pub(crate) fn cannot_return_reference_to_local(
&self,
span: Span,
return_kind: &str,
reference_desc: &str,
path_desc: &str,
) -> DiagnosticBuilder<'cx, ErrorGuaranteed> {
let mut err = struct_span_err!(
self,
span,
E0515,
"cannot {RETURN} {REFERENCE} {LOCAL}",
RETURN = return_kind,
REFERENCE = reference_desc,
LOCAL = path_desc,
);
err.span_label(
span,
format!("{}s a {} data owned by the current function", return_kind, reference_desc),
);
err
}
pub(crate) fn cannot_capture_in_long_lived_closure(
&self,
closure_span: Span,
closure_kind: &str,
borrowed_path: &str,
capture_span: Span,
) -> DiagnosticBuilder<'cx, ErrorGuaranteed> {
let mut err = struct_span_err!(
self,
closure_span,
E0373,
"{} may outlive the current function, but it borrows {}, which is owned by the current \
function",
closure_kind,
borrowed_path,
);
err.span_label(capture_span, format!("{} is borrowed here", borrowed_path))
.span_label(closure_span, format!("may outlive borrowed value {}", borrowed_path));
err
}
pub(crate) fn thread_local_value_does_not_live_long_enough(
&self,
span: Span,
) -> DiagnosticBuilder<'cx, ErrorGuaranteed> {
struct_span_err!(self, span, E0712, "thread-local variable borrowed past end of function",)
}
pub(crate) fn temporary_value_borrowed_for_too_long(
&self,
span: Span,
) -> DiagnosticBuilder<'cx, ErrorGuaranteed> {
struct_span_err!(self, span, E0716, "temporary value dropped while borrowed",)
}
#[rustc_lint_diagnostics]
pub(crate) fn struct_span_err_with_code<S: Into<MultiSpan>>(
&self,
sp: S,
msg: impl Into<DiagnosticMessage>,
code: DiagnosticId,
) -> DiagnosticBuilder<'tcx, ErrorGuaranteed> {
self.infcx.tcx.sess.struct_span_err_with_code(sp, msg, code)
}
}
pub(crate) fn borrowed_data_escapes_closure<'tcx>(
tcx: TyCtxt<'tcx>,
escape_span: Span,
escapes_from: &str,
) -> DiagnosticBuilder<'tcx, ErrorGuaranteed> {
struct_span_err!(
tcx.sess,
escape_span,
E0521,
"borrowed data escapes outside of {}",
escapes_from,
)
}