256c27e748
Continuing the work from #137350. Removes the unused methods: `expect_variant`, `expect_field`, `expect_foreign_item`. Every method gains a `hir_` prefix.
1498 lines
64 KiB
Rust
1498 lines
64 KiB
Rust
//! Borrow checker diagnostics.
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use std::collections::BTreeMap;
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use rustc_abi::{FieldIdx, VariantIdx};
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use rustc_data_structures::fx::FxIndexMap;
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use rustc_errors::{Applicability, Diag, EmissionGuarantee, MultiSpan, listify};
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use rustc_hir::def::{CtorKind, Namespace};
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use rustc_hir::{self as hir, CoroutineKind, LangItem};
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use rustc_index::IndexSlice;
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use rustc_infer::infer::{
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BoundRegionConversionTime, NllRegionVariableOrigin, RegionVariableOrigin,
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};
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use rustc_infer::traits::SelectionError;
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use rustc_middle::bug;
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use rustc_middle::mir::{
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AggregateKind, CallSource, ConstOperand, ConstraintCategory, FakeReadCause, Local, LocalInfo,
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LocalKind, Location, Operand, Place, PlaceRef, PlaceTy, ProjectionElem, Rvalue, Statement,
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StatementKind, Terminator, TerminatorKind, find_self_call,
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};
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use rustc_middle::ty::print::Print;
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use rustc_middle::ty::{self, Ty, TyCtxt};
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use rustc_mir_dataflow::move_paths::{InitLocation, LookupResult, MoveOutIndex};
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use rustc_span::def_id::LocalDefId;
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use rustc_span::source_map::Spanned;
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use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span, Symbol, sym};
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use rustc_trait_selection::error_reporting::InferCtxtErrorExt;
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use rustc_trait_selection::error_reporting::traits::call_kind::{CallDesugaringKind, call_kind};
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use rustc_trait_selection::infer::InferCtxtExt;
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use rustc_trait_selection::traits::{
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FulfillmentError, FulfillmentErrorCode, type_known_to_meet_bound_modulo_regions,
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};
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use tracing::debug;
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use super::MirBorrowckCtxt;
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use super::borrow_set::BorrowData;
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use crate::constraints::OutlivesConstraint;
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use crate::fluent_generated as fluent;
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use crate::nll::ConstraintDescription;
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use crate::session_diagnostics::{
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CaptureArgLabel, CaptureReasonLabel, CaptureReasonNote, CaptureReasonSuggest, CaptureVarCause,
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CaptureVarKind, CaptureVarPathUseCause, OnClosureNote,
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};
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mod find_all_local_uses;
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mod find_use;
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mod outlives_suggestion;
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mod region_name;
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mod var_name;
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mod bound_region_errors;
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mod conflict_errors;
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mod explain_borrow;
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mod move_errors;
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mod mutability_errors;
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mod opaque_suggestions;
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mod region_errors;
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pub(crate) use bound_region_errors::{ToUniverseInfo, UniverseInfo};
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pub(crate) use move_errors::{IllegalMoveOriginKind, MoveError};
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pub(crate) use mutability_errors::AccessKind;
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pub(crate) use outlives_suggestion::OutlivesSuggestionBuilder;
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pub(crate) use region_errors::{ErrorConstraintInfo, RegionErrorKind, RegionErrors};
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pub(crate) use region_name::{RegionName, RegionNameSource};
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pub(crate) use rustc_trait_selection::error_reporting::traits::call_kind::CallKind;
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pub(super) struct DescribePlaceOpt {
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including_downcast: bool,
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/// Enable/Disable tuple fields.
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/// For example `x` tuple. if it's `true` `x.0`. Otherwise `x`
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including_tuple_field: bool,
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}
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pub(super) struct IncludingTupleField(pub(super) bool);
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enum BufferedDiag<'infcx> {
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Error(Diag<'infcx>),
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NonError(Diag<'infcx, ()>),
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}
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impl<'infcx> BufferedDiag<'infcx> {
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fn sort_span(&self) -> Span {
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match self {
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BufferedDiag::Error(diag) => diag.sort_span,
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BufferedDiag::NonError(diag) => diag.sort_span,
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}
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}
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}
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#[derive(Default)]
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pub(crate) struct BorrowckDiagnosticsBuffer<'infcx, 'tcx> {
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/// This field keeps track of move errors that are to be reported for given move indices.
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///
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/// There are situations where many errors can be reported for a single move out (see
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/// #53807) and we want only the best of those errors.
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///
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/// The `report_use_of_moved_or_uninitialized` function checks this map and replaces the
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/// diagnostic (if there is one) if the `Place` of the error being reported is a prefix of
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/// the `Place` of the previous most diagnostic. This happens instead of buffering the
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/// error. Once all move errors have been reported, any diagnostics in this map are added
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/// to the buffer to be emitted.
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///
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/// `BTreeMap` is used to preserve the order of insertions when iterating. This is necessary
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/// when errors in the map are being re-added to the error buffer so that errors with the
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/// same primary span come out in a consistent order.
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buffered_move_errors: BTreeMap<Vec<MoveOutIndex>, (PlaceRef<'tcx>, Diag<'infcx>)>,
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buffered_mut_errors: FxIndexMap<Span, (Diag<'infcx>, usize)>,
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/// Buffer of diagnostics to be reported. A mixture of error and non-error diagnostics.
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buffered_diags: Vec<BufferedDiag<'infcx>>,
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}
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impl<'infcx, 'tcx> BorrowckDiagnosticsBuffer<'infcx, 'tcx> {
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pub(crate) fn buffer_non_error(&mut self, diag: Diag<'infcx, ()>) {
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self.buffered_diags.push(BufferedDiag::NonError(diag));
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}
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}
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impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
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pub(crate) fn buffer_error(&mut self, diag: Diag<'infcx>) {
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self.diags_buffer.buffered_diags.push(BufferedDiag::Error(diag));
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}
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pub(crate) fn buffer_non_error(&mut self, diag: Diag<'infcx, ()>) {
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self.diags_buffer.buffer_non_error(diag);
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}
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pub(crate) fn buffer_move_error(
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&mut self,
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move_out_indices: Vec<MoveOutIndex>,
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place_and_err: (PlaceRef<'tcx>, Diag<'infcx>),
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) -> bool {
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if let Some((_, diag)) =
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self.diags_buffer.buffered_move_errors.insert(move_out_indices, place_and_err)
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{
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// Cancel the old diagnostic so we don't ICE
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diag.cancel();
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false
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} else {
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true
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}
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}
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pub(crate) fn get_buffered_mut_error(&mut self, span: Span) -> Option<(Diag<'infcx>, usize)> {
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// FIXME(#120456) - is `swap_remove` correct?
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self.diags_buffer.buffered_mut_errors.swap_remove(&span)
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}
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pub(crate) fn buffer_mut_error(&mut self, span: Span, diag: Diag<'infcx>, count: usize) {
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self.diags_buffer.buffered_mut_errors.insert(span, (diag, count));
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}
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pub(crate) fn emit_errors(&mut self) -> Option<ErrorGuaranteed> {
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let mut res = self.infcx.tainted_by_errors();
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// Buffer any move errors that we collected and de-duplicated.
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for (_, (_, diag)) in std::mem::take(&mut self.diags_buffer.buffered_move_errors) {
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// We have already set tainted for this error, so just buffer it.
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self.buffer_error(diag);
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}
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for (_, (mut diag, count)) in std::mem::take(&mut self.diags_buffer.buffered_mut_errors) {
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if count > 10 {
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#[allow(rustc::diagnostic_outside_of_impl)]
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#[allow(rustc::untranslatable_diagnostic)]
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diag.note(format!("...and {} other attempted mutable borrows", count - 10));
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}
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self.buffer_error(diag);
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}
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if !self.diags_buffer.buffered_diags.is_empty() {
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self.diags_buffer.buffered_diags.sort_by_key(|buffered_diag| buffered_diag.sort_span());
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for buffered_diag in self.diags_buffer.buffered_diags.drain(..) {
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match buffered_diag {
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BufferedDiag::Error(diag) => res = Some(diag.emit()),
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BufferedDiag::NonError(diag) => diag.emit(),
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}
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}
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}
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res
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}
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pub(crate) fn has_buffered_diags(&self) -> bool {
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self.diags_buffer.buffered_diags.is_empty()
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}
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pub(crate) fn has_move_error(
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&self,
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move_out_indices: &[MoveOutIndex],
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) -> Option<&(PlaceRef<'tcx>, Diag<'infcx>)> {
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self.diags_buffer.buffered_move_errors.get(move_out_indices)
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}
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}
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impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
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/// Adds a suggestion when a closure is invoked twice with a moved variable or when a closure
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/// is moved after being invoked.
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///
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/// ```text
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/// note: closure cannot be invoked more than once because it moves the variable `dict` out of
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/// its environment
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/// --> $DIR/issue-42065.rs:16:29
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/// |
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/// LL | for (key, value) in dict {
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/// | ^^^^
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/// ```
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#[allow(rustc::diagnostic_outside_of_impl)] // FIXME
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pub(super) fn add_moved_or_invoked_closure_note(
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&self,
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location: Location,
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place: PlaceRef<'tcx>,
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diag: &mut Diag<'infcx>,
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) -> bool {
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debug!("add_moved_or_invoked_closure_note: location={:?} place={:?}", location, place);
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let mut target = place.local_or_deref_local();
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for stmt in &self.body[location.block].statements[location.statement_index..] {
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debug!("add_moved_or_invoked_closure_note: stmt={:?} target={:?}", stmt, target);
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if let StatementKind::Assign(box (into, Rvalue::Use(from))) = &stmt.kind {
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debug!("add_fnonce_closure_note: into={:?} from={:?}", into, from);
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match from {
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Operand::Copy(place) | Operand::Move(place)
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if target == place.local_or_deref_local() =>
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{
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target = into.local_or_deref_local()
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}
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_ => {}
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}
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}
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}
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// Check if we are attempting to call a closure after it has been invoked.
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let terminator = self.body[location.block].terminator();
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debug!("add_moved_or_invoked_closure_note: terminator={:?}", terminator);
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if let TerminatorKind::Call {
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func: Operand::Constant(box ConstOperand { const_, .. }),
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args,
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..
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} = &terminator.kind
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{
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if let ty::FnDef(id, _) = *const_.ty().kind() {
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debug!("add_moved_or_invoked_closure_note: id={:?}", id);
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if self.infcx.tcx.is_lang_item(self.infcx.tcx.parent(id), LangItem::FnOnce) {
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let closure = match args.first() {
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Some(Spanned {
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node: Operand::Copy(place) | Operand::Move(place), ..
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}) if target == place.local_or_deref_local() => {
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place.local_or_deref_local().unwrap()
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}
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_ => return false,
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};
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debug!("add_moved_or_invoked_closure_note: closure={:?}", closure);
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if let ty::Closure(did, _) = self.body.local_decls[closure].ty.kind() {
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let did = did.expect_local();
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if let Some((span, hir_place)) = self.infcx.tcx.closure_kind_origin(did) {
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diag.subdiagnostic(OnClosureNote::InvokedTwice {
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place_name: &ty::place_to_string_for_capture(
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self.infcx.tcx,
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hir_place,
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),
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span: *span,
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});
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return true;
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}
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}
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}
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}
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}
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// Check if we are just moving a closure after it has been invoked.
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if let Some(target) = target {
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if let ty::Closure(did, _) = self.body.local_decls[target].ty.kind() {
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let did = did.expect_local();
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if let Some((span, hir_place)) = self.infcx.tcx.closure_kind_origin(did) {
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diag.subdiagnostic(OnClosureNote::MovedTwice {
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place_name: &ty::place_to_string_for_capture(self.infcx.tcx, hir_place),
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span: *span,
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});
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return true;
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}
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}
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}
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false
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}
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/// End-user visible description of `place` if one can be found.
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/// If the place is a temporary for instance, `"value"` will be returned.
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pub(super) fn describe_any_place(&self, place_ref: PlaceRef<'tcx>) -> String {
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match self.describe_place(place_ref) {
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Some(mut descr) => {
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// Surround descr with `backticks`.
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descr.reserve(2);
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descr.insert(0, '`');
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descr.push('`');
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descr
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}
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None => "value".to_string(),
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}
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}
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/// End-user visible description of `place` if one can be found.
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/// If the place is a temporary for instance, `None` will be returned.
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pub(super) fn describe_place(&self, place_ref: PlaceRef<'tcx>) -> Option<String> {
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self.describe_place_with_options(
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place_ref,
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DescribePlaceOpt { including_downcast: false, including_tuple_field: true },
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)
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}
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/// End-user visible description of `place` if one can be found. If the place is a temporary
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/// for instance, `None` will be returned.
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/// `IncludingDowncast` parameter makes the function return `None` if `ProjectionElem` is
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/// `Downcast` and `IncludingDowncast` is true
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pub(super) fn describe_place_with_options(
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&self,
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place: PlaceRef<'tcx>,
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opt: DescribePlaceOpt,
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) -> Option<String> {
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let local = place.local;
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let mut autoderef_index = None;
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let mut buf = String::new();
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let mut ok = self.append_local_to_string(local, &mut buf);
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for (index, elem) in place.projection.into_iter().enumerate() {
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match elem {
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ProjectionElem::Deref => {
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if index == 0 {
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if self.body.local_decls[local].is_ref_for_guard() {
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continue;
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}
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if let LocalInfo::StaticRef { def_id, .. } =
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*self.body.local_decls[local].local_info()
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{
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buf.push_str(self.infcx.tcx.item_name(def_id).as_str());
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ok = Ok(());
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continue;
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}
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}
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if let Some(field) = self.is_upvar_field_projection(PlaceRef {
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local,
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projection: place.projection.split_at(index + 1).0,
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}) {
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let var_index = field.index();
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buf = self.upvars[var_index].to_string(self.infcx.tcx);
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ok = Ok(());
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if !self.upvars[var_index].is_by_ref() {
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buf.insert(0, '*');
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}
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} else {
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if autoderef_index.is_none() {
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autoderef_index = match place.projection.iter().rposition(|elem| {
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!matches!(
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elem,
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ProjectionElem::Deref | ProjectionElem::Downcast(..)
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)
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}) {
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Some(index) => Some(index + 1),
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None => Some(0),
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};
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}
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if index >= autoderef_index.unwrap() {
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buf.insert(0, '*');
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}
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}
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}
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ProjectionElem::Downcast(..) if opt.including_downcast => return None,
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ProjectionElem::Downcast(..) => (),
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ProjectionElem::OpaqueCast(..) => (),
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ProjectionElem::Subtype(..) => (),
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ProjectionElem::UnwrapUnsafeBinder(_) => (),
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ProjectionElem::Field(field, _ty) => {
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// FIXME(project-rfc_2229#36): print capture precisely here.
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if let Some(field) = self.is_upvar_field_projection(PlaceRef {
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local,
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projection: place.projection.split_at(index + 1).0,
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}) {
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buf = self.upvars[field.index()].to_string(self.infcx.tcx);
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ok = Ok(());
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} else {
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let field_name = self.describe_field(
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PlaceRef { local, projection: place.projection.split_at(index).0 },
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*field,
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IncludingTupleField(opt.including_tuple_field),
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);
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if let Some(field_name_str) = field_name {
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buf.push('.');
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buf.push_str(&field_name_str);
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}
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}
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}
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ProjectionElem::Index(index) => {
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buf.push('[');
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if self.append_local_to_string(*index, &mut buf).is_err() {
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buf.push('_');
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}
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buf.push(']');
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}
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ProjectionElem::ConstantIndex { .. } | ProjectionElem::Subslice { .. } => {
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// Since it isn't possible to borrow an element on a particular index and
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// then use another while the borrow is held, don't output indices details
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// to avoid confusing the end-user
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buf.push_str("[..]");
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}
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}
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}
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ok.ok().map(|_| buf)
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}
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fn describe_name(&self, place: PlaceRef<'tcx>) -> Option<Symbol> {
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for elem in place.projection.into_iter() {
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match elem {
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ProjectionElem::Downcast(Some(name), _) => {
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return Some(*name);
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}
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_ => {}
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}
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}
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None
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}
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|
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/// Appends end-user visible description of the `local` place to `buf`. If `local` doesn't have
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/// a name, or its name was generated by the compiler, then `Err` is returned
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fn append_local_to_string(&self, local: Local, buf: &mut String) -> Result<(), ()> {
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let decl = &self.body.local_decls[local];
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match self.local_names[local] {
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Some(name) if !decl.from_compiler_desugaring() => {
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buf.push_str(name.as_str());
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Ok(())
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}
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_ => Err(()),
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}
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}
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|
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/// End-user visible description of the `field`nth field of `base`
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|
fn describe_field(
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&self,
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place: PlaceRef<'tcx>,
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field: FieldIdx,
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including_tuple_field: IncludingTupleField,
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) -> Option<String> {
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let place_ty = match place {
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PlaceRef { local, projection: [] } => PlaceTy::from_ty(self.body.local_decls[local].ty),
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PlaceRef { local, projection: [proj_base @ .., elem] } => match elem {
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ProjectionElem::Deref
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| ProjectionElem::Index(..)
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| ProjectionElem::ConstantIndex { .. }
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| ProjectionElem::Subslice { .. } => {
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PlaceRef { local, projection: proj_base }.ty(self.body, self.infcx.tcx)
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}
|
|
ProjectionElem::Downcast(..) => place.ty(self.body, self.infcx.tcx),
|
|
ProjectionElem::Subtype(ty)
|
|
| ProjectionElem::OpaqueCast(ty)
|
|
| ProjectionElem::UnwrapUnsafeBinder(ty) => PlaceTy::from_ty(*ty),
|
|
ProjectionElem::Field(_, field_type) => PlaceTy::from_ty(*field_type),
|
|
},
|
|
};
|
|
self.describe_field_from_ty(
|
|
place_ty.ty,
|
|
field,
|
|
place_ty.variant_index,
|
|
including_tuple_field,
|
|
)
|
|
}
|
|
|
|
/// End-user visible description of the `field_index`nth field of `ty`
|
|
fn describe_field_from_ty(
|
|
&self,
|
|
ty: Ty<'_>,
|
|
field: FieldIdx,
|
|
variant_index: Option<VariantIdx>,
|
|
including_tuple_field: IncludingTupleField,
|
|
) -> Option<String> {
|
|
if let Some(boxed_ty) = ty.boxed_ty() {
|
|
// If the type is a box, the field is described from the boxed type
|
|
self.describe_field_from_ty(boxed_ty, field, variant_index, including_tuple_field)
|
|
} else {
|
|
match *ty.kind() {
|
|
ty::Adt(def, _) => {
|
|
let variant = if let Some(idx) = variant_index {
|
|
assert!(def.is_enum());
|
|
def.variant(idx)
|
|
} else {
|
|
def.non_enum_variant()
|
|
};
|
|
if !including_tuple_field.0 && variant.ctor_kind() == Some(CtorKind::Fn) {
|
|
return None;
|
|
}
|
|
Some(variant.fields[field].name.to_string())
|
|
}
|
|
ty::Tuple(_) => Some(field.index().to_string()),
|
|
ty::Ref(_, ty, _) | ty::RawPtr(ty, _) => {
|
|
self.describe_field_from_ty(ty, field, variant_index, including_tuple_field)
|
|
}
|
|
ty::Array(ty, _) | ty::Slice(ty) => {
|
|
self.describe_field_from_ty(ty, field, variant_index, including_tuple_field)
|
|
}
|
|
ty::Closure(def_id, _) | ty::Coroutine(def_id, _) => {
|
|
// We won't be borrowck'ing here if the closure came from another crate,
|
|
// so it's safe to call `expect_local`.
|
|
//
|
|
// We know the field exists so it's safe to call operator[] and `unwrap` here.
|
|
let def_id = def_id.expect_local();
|
|
let var_id =
|
|
self.infcx.tcx.closure_captures(def_id)[field.index()].get_root_variable();
|
|
|
|
Some(self.infcx.tcx.hir_name(var_id).to_string())
|
|
}
|
|
_ => {
|
|
// Might need a revision when the fields in trait RFC is implemented
|
|
// (https://github.com/rust-lang/rfcs/pull/1546)
|
|
bug!("End-user description not implemented for field access on `{:?}`", ty);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
pub(super) fn borrowed_content_source(
|
|
&self,
|
|
deref_base: PlaceRef<'tcx>,
|
|
) -> BorrowedContentSource<'tcx> {
|
|
let tcx = self.infcx.tcx;
|
|
|
|
// Look up the provided place and work out the move path index for it,
|
|
// we'll use this to check whether it was originally from an overloaded
|
|
// operator.
|
|
match self.move_data.rev_lookup.find(deref_base) {
|
|
LookupResult::Exact(mpi) | LookupResult::Parent(Some(mpi)) => {
|
|
debug!("borrowed_content_source: mpi={:?}", mpi);
|
|
|
|
for i in &self.move_data.init_path_map[mpi] {
|
|
let init = &self.move_data.inits[*i];
|
|
debug!("borrowed_content_source: init={:?}", init);
|
|
// We're only interested in statements that initialized a value, not the
|
|
// initializations from arguments.
|
|
let InitLocation::Statement(loc) = init.location else { continue };
|
|
|
|
let bbd = &self.body[loc.block];
|
|
let is_terminator = bbd.statements.len() == loc.statement_index;
|
|
debug!(
|
|
"borrowed_content_source: loc={:?} is_terminator={:?}",
|
|
loc, is_terminator,
|
|
);
|
|
if !is_terminator {
|
|
continue;
|
|
} else if let Some(Terminator {
|
|
kind:
|
|
TerminatorKind::Call {
|
|
func,
|
|
call_source: CallSource::OverloadedOperator,
|
|
..
|
|
},
|
|
..
|
|
}) = &bbd.terminator
|
|
{
|
|
if let Some(source) =
|
|
BorrowedContentSource::from_call(func.ty(self.body, tcx), tcx)
|
|
{
|
|
return source;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
// Base is a `static` so won't be from an overloaded operator
|
|
_ => (),
|
|
};
|
|
|
|
// If we didn't find an overloaded deref or index, then assume it's a
|
|
// built in deref and check the type of the base.
|
|
let base_ty = deref_base.ty(self.body, tcx).ty;
|
|
if base_ty.is_raw_ptr() {
|
|
BorrowedContentSource::DerefRawPointer
|
|
} else if base_ty.is_mutable_ptr() {
|
|
BorrowedContentSource::DerefMutableRef
|
|
} else {
|
|
BorrowedContentSource::DerefSharedRef
|
|
}
|
|
}
|
|
|
|
/// Return the name of the provided `Ty` (that must be a reference) with a synthesized lifetime
|
|
/// name where required.
|
|
pub(super) fn get_name_for_ty(&self, ty: Ty<'tcx>, counter: usize) -> String {
|
|
let mut printer = ty::print::FmtPrinter::new(self.infcx.tcx, Namespace::TypeNS);
|
|
|
|
// We need to add synthesized lifetimes where appropriate. We do
|
|
// this by hooking into the pretty printer and telling it to label the
|
|
// lifetimes without names with the value `'0`.
|
|
if let ty::Ref(region, ..) = ty.kind() {
|
|
match **region {
|
|
ty::ReBound(_, ty::BoundRegion { kind: br, .. })
|
|
| ty::RePlaceholder(ty::PlaceholderRegion {
|
|
bound: ty::BoundRegion { kind: br, .. },
|
|
..
|
|
}) => printer.region_highlight_mode.highlighting_bound_region(br, counter),
|
|
_ => {}
|
|
}
|
|
}
|
|
|
|
ty.print(&mut printer).unwrap();
|
|
printer.into_buffer()
|
|
}
|
|
|
|
/// Returns the name of the provided `Ty` (that must be a reference)'s region with a
|
|
/// synthesized lifetime name where required.
|
|
pub(super) fn get_region_name_for_ty(&self, ty: Ty<'tcx>, counter: usize) -> String {
|
|
let mut printer = ty::print::FmtPrinter::new(self.infcx.tcx, Namespace::TypeNS);
|
|
|
|
let region = if let ty::Ref(region, ..) = ty.kind() {
|
|
match **region {
|
|
ty::ReBound(_, ty::BoundRegion { kind: br, .. })
|
|
| ty::RePlaceholder(ty::PlaceholderRegion {
|
|
bound: ty::BoundRegion { kind: br, .. },
|
|
..
|
|
}) => printer.region_highlight_mode.highlighting_bound_region(br, counter),
|
|
_ => {}
|
|
}
|
|
region
|
|
} else {
|
|
bug!("ty for annotation of borrow region is not a reference");
|
|
};
|
|
|
|
region.print(&mut printer).unwrap();
|
|
printer.into_buffer()
|
|
}
|
|
|
|
/// Add a note to region errors and borrow explanations when higher-ranked regions in predicates
|
|
/// implicitly introduce an "outlives `'static`" constraint.
|
|
fn add_placeholder_from_predicate_note<G: EmissionGuarantee>(
|
|
&self,
|
|
err: &mut Diag<'_, G>,
|
|
path: &[OutlivesConstraint<'tcx>],
|
|
) {
|
|
let predicate_span = path.iter().find_map(|constraint| {
|
|
let outlived = constraint.sub;
|
|
if let Some(origin) = self.regioncx.var_infos.get(outlived)
|
|
&& let RegionVariableOrigin::Nll(NllRegionVariableOrigin::Placeholder(_)) =
|
|
origin.origin
|
|
&& let ConstraintCategory::Predicate(span) = constraint.category
|
|
{
|
|
Some(span)
|
|
} else {
|
|
None
|
|
}
|
|
});
|
|
|
|
if let Some(span) = predicate_span {
|
|
err.span_note(span, "due to current limitations in the borrow checker, this implies a `'static` lifetime");
|
|
}
|
|
}
|
|
|
|
/// Add a label to region errors and borrow explanations when outlives constraints arise from
|
|
/// proving a type implements `Sized` or `Copy`.
|
|
fn add_sized_or_copy_bound_info<G: EmissionGuarantee>(
|
|
&self,
|
|
err: &mut Diag<'_, G>,
|
|
blamed_category: ConstraintCategory<'tcx>,
|
|
path: &[OutlivesConstraint<'tcx>],
|
|
) {
|
|
for sought_category in [ConstraintCategory::SizedBound, ConstraintCategory::CopyBound] {
|
|
if sought_category != blamed_category
|
|
&& let Some(sought_constraint) = path.iter().find(|c| c.category == sought_category)
|
|
{
|
|
let label = format!(
|
|
"requirement occurs due to {}",
|
|
sought_category.description().trim_end()
|
|
);
|
|
err.span_label(sought_constraint.span, label);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/// The span(s) associated to a use of a place.
|
|
#[derive(Copy, Clone, PartialEq, Eq, Debug)]
|
|
pub(super) enum UseSpans<'tcx> {
|
|
/// The access is caused by capturing a variable for a closure.
|
|
ClosureUse {
|
|
/// This is true if the captured variable was from a coroutine.
|
|
closure_kind: hir::ClosureKind,
|
|
/// The span of the args of the closure, including the `move` keyword if
|
|
/// it's present.
|
|
args_span: Span,
|
|
/// The span of the use resulting in capture kind
|
|
/// Check `ty::CaptureInfo` for more details
|
|
capture_kind_span: Span,
|
|
/// The span of the use resulting in the captured path
|
|
/// Check `ty::CaptureInfo` for more details
|
|
path_span: Span,
|
|
},
|
|
/// The access is caused by using a variable as the receiver of a method
|
|
/// that takes 'self'
|
|
FnSelfUse {
|
|
/// The span of the variable being moved
|
|
var_span: Span,
|
|
/// The span of the method call on the variable
|
|
fn_call_span: Span,
|
|
/// The definition span of the method being called
|
|
fn_span: Span,
|
|
kind: CallKind<'tcx>,
|
|
},
|
|
/// This access is caused by a `match` or `if let` pattern.
|
|
PatUse(Span),
|
|
/// This access has a single span associated to it: common case.
|
|
OtherUse(Span),
|
|
}
|
|
|
|
impl UseSpans<'_> {
|
|
pub(super) fn args_or_use(self) -> Span {
|
|
match self {
|
|
UseSpans::ClosureUse { args_span: span, .. }
|
|
| UseSpans::PatUse(span)
|
|
| UseSpans::OtherUse(span) => span,
|
|
UseSpans::FnSelfUse { var_span, .. } => var_span,
|
|
}
|
|
}
|
|
|
|
/// Returns the span of `self`, in the case of a `ClosureUse` returns the `path_span`
|
|
pub(super) fn var_or_use_path_span(self) -> Span {
|
|
match self {
|
|
UseSpans::ClosureUse { path_span: span, .. }
|
|
| UseSpans::PatUse(span)
|
|
| UseSpans::OtherUse(span) => span,
|
|
UseSpans::FnSelfUse { var_span, .. } => var_span,
|
|
}
|
|
}
|
|
|
|
/// Returns the span of `self`, in the case of a `ClosureUse` returns the `capture_kind_span`
|
|
pub(super) fn var_or_use(self) -> Span {
|
|
match self {
|
|
UseSpans::ClosureUse { capture_kind_span: span, .. }
|
|
| UseSpans::PatUse(span)
|
|
| UseSpans::OtherUse(span) => span,
|
|
UseSpans::FnSelfUse { var_span, .. } => var_span,
|
|
}
|
|
}
|
|
|
|
// FIXME(coroutines): Make this just return the `ClosureKind` directly?
|
|
pub(super) fn coroutine_kind(self) -> Option<CoroutineKind> {
|
|
match self {
|
|
UseSpans::ClosureUse {
|
|
closure_kind: hir::ClosureKind::Coroutine(coroutine_kind),
|
|
..
|
|
} => Some(coroutine_kind),
|
|
_ => None,
|
|
}
|
|
}
|
|
|
|
/// Add a span label to the arguments of the closure, if it exists.
|
|
#[allow(rustc::diagnostic_outside_of_impl)]
|
|
pub(super) fn args_subdiag(self, err: &mut Diag<'_>, f: impl FnOnce(Span) -> CaptureArgLabel) {
|
|
if let UseSpans::ClosureUse { args_span, .. } = self {
|
|
err.subdiagnostic(f(args_span));
|
|
}
|
|
}
|
|
|
|
/// Add a span label to the use of the captured variable, if it exists.
|
|
/// only adds label to the `path_span`
|
|
#[allow(rustc::diagnostic_outside_of_impl)]
|
|
pub(super) fn var_path_only_subdiag(
|
|
self,
|
|
err: &mut Diag<'_>,
|
|
action: crate::InitializationRequiringAction,
|
|
) {
|
|
use CaptureVarPathUseCause::*;
|
|
|
|
use crate::InitializationRequiringAction::*;
|
|
if let UseSpans::ClosureUse { closure_kind, path_span, .. } = self {
|
|
match closure_kind {
|
|
hir::ClosureKind::Coroutine(_) => {
|
|
err.subdiagnostic(match action {
|
|
Borrow => BorrowInCoroutine { path_span },
|
|
MatchOn | Use => UseInCoroutine { path_span },
|
|
Assignment => AssignInCoroutine { path_span },
|
|
PartialAssignment => AssignPartInCoroutine { path_span },
|
|
});
|
|
}
|
|
hir::ClosureKind::Closure | hir::ClosureKind::CoroutineClosure(_) => {
|
|
err.subdiagnostic(match action {
|
|
Borrow => BorrowInClosure { path_span },
|
|
MatchOn | Use => UseInClosure { path_span },
|
|
Assignment => AssignInClosure { path_span },
|
|
PartialAssignment => AssignPartInClosure { path_span },
|
|
});
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Add a subdiagnostic to the use of the captured variable, if it exists.
|
|
#[allow(rustc::diagnostic_outside_of_impl)]
|
|
pub(super) fn var_subdiag(
|
|
self,
|
|
err: &mut Diag<'_>,
|
|
kind: Option<rustc_middle::mir::BorrowKind>,
|
|
f: impl FnOnce(hir::ClosureKind, Span) -> CaptureVarCause,
|
|
) {
|
|
if let UseSpans::ClosureUse { closure_kind, capture_kind_span, path_span, .. } = self {
|
|
if capture_kind_span != path_span {
|
|
err.subdiagnostic(match kind {
|
|
Some(kd) => match kd {
|
|
rustc_middle::mir::BorrowKind::Shared
|
|
| rustc_middle::mir::BorrowKind::Fake(_) => {
|
|
CaptureVarKind::Immut { kind_span: capture_kind_span }
|
|
}
|
|
|
|
rustc_middle::mir::BorrowKind::Mut { .. } => {
|
|
CaptureVarKind::Mut { kind_span: capture_kind_span }
|
|
}
|
|
},
|
|
None => CaptureVarKind::Move { kind_span: capture_kind_span },
|
|
});
|
|
};
|
|
let diag = f(closure_kind, path_span);
|
|
err.subdiagnostic(diag);
|
|
}
|
|
}
|
|
|
|
/// Returns `false` if this place is not used in a closure.
|
|
pub(super) fn for_closure(&self) -> bool {
|
|
match *self {
|
|
UseSpans::ClosureUse { closure_kind, .. } => {
|
|
matches!(closure_kind, hir::ClosureKind::Closure)
|
|
}
|
|
_ => false,
|
|
}
|
|
}
|
|
|
|
/// Returns `false` if this place is not used in a coroutine.
|
|
pub(super) fn for_coroutine(&self) -> bool {
|
|
match *self {
|
|
// FIXME(coroutines): Do we want this to apply to synthetic coroutines?
|
|
UseSpans::ClosureUse { closure_kind, .. } => {
|
|
matches!(closure_kind, hir::ClosureKind::Coroutine(..))
|
|
}
|
|
_ => false,
|
|
}
|
|
}
|
|
|
|
pub(super) fn or_else<F>(self, if_other: F) -> Self
|
|
where
|
|
F: FnOnce() -> Self,
|
|
{
|
|
match self {
|
|
closure @ UseSpans::ClosureUse { .. } => closure,
|
|
UseSpans::PatUse(_) | UseSpans::OtherUse(_) => if_other(),
|
|
fn_self @ UseSpans::FnSelfUse { .. } => fn_self,
|
|
}
|
|
}
|
|
}
|
|
|
|
pub(super) enum BorrowedContentSource<'tcx> {
|
|
DerefRawPointer,
|
|
DerefMutableRef,
|
|
DerefSharedRef,
|
|
OverloadedDeref(Ty<'tcx>),
|
|
OverloadedIndex(Ty<'tcx>),
|
|
}
|
|
|
|
impl<'tcx> BorrowedContentSource<'tcx> {
|
|
pub(super) fn describe_for_unnamed_place(&self, tcx: TyCtxt<'_>) -> String {
|
|
match *self {
|
|
BorrowedContentSource::DerefRawPointer => "a raw pointer".to_string(),
|
|
BorrowedContentSource::DerefSharedRef => "a shared reference".to_string(),
|
|
BorrowedContentSource::DerefMutableRef => "a mutable reference".to_string(),
|
|
BorrowedContentSource::OverloadedDeref(ty) => ty
|
|
.ty_adt_def()
|
|
.and_then(|adt| match tcx.get_diagnostic_name(adt.did())? {
|
|
name @ (sym::Rc | sym::Arc) => Some(format!("an `{name}`")),
|
|
_ => None,
|
|
})
|
|
.unwrap_or_else(|| format!("dereference of `{ty}`")),
|
|
BorrowedContentSource::OverloadedIndex(ty) => format!("index of `{ty}`"),
|
|
}
|
|
}
|
|
|
|
pub(super) fn describe_for_named_place(&self) -> Option<&'static str> {
|
|
match *self {
|
|
BorrowedContentSource::DerefRawPointer => Some("raw pointer"),
|
|
BorrowedContentSource::DerefSharedRef => Some("shared reference"),
|
|
BorrowedContentSource::DerefMutableRef => Some("mutable reference"),
|
|
// Overloaded deref and index operators should be evaluated into a
|
|
// temporary. So we don't need a description here.
|
|
BorrowedContentSource::OverloadedDeref(_)
|
|
| BorrowedContentSource::OverloadedIndex(_) => None,
|
|
}
|
|
}
|
|
|
|
pub(super) fn describe_for_immutable_place(&self, tcx: TyCtxt<'_>) -> String {
|
|
match *self {
|
|
BorrowedContentSource::DerefRawPointer => "a `*const` pointer".to_string(),
|
|
BorrowedContentSource::DerefSharedRef => "a `&` reference".to_string(),
|
|
BorrowedContentSource::DerefMutableRef => {
|
|
bug!("describe_for_immutable_place: DerefMutableRef isn't immutable")
|
|
}
|
|
BorrowedContentSource::OverloadedDeref(ty) => ty
|
|
.ty_adt_def()
|
|
.and_then(|adt| match tcx.get_diagnostic_name(adt.did())? {
|
|
name @ (sym::Rc | sym::Arc) => Some(format!("an `{name}`")),
|
|
_ => None,
|
|
})
|
|
.unwrap_or_else(|| format!("dereference of `{ty}`")),
|
|
BorrowedContentSource::OverloadedIndex(ty) => format!("an index of `{ty}`"),
|
|
}
|
|
}
|
|
|
|
fn from_call(func: Ty<'tcx>, tcx: TyCtxt<'tcx>) -> Option<Self> {
|
|
match *func.kind() {
|
|
ty::FnDef(def_id, args) => {
|
|
let trait_id = tcx.trait_of_item(def_id)?;
|
|
|
|
if tcx.is_lang_item(trait_id, LangItem::Deref)
|
|
|| tcx.is_lang_item(trait_id, LangItem::DerefMut)
|
|
{
|
|
Some(BorrowedContentSource::OverloadedDeref(args.type_at(0)))
|
|
} else if tcx.is_lang_item(trait_id, LangItem::Index)
|
|
|| tcx.is_lang_item(trait_id, LangItem::IndexMut)
|
|
{
|
|
Some(BorrowedContentSource::OverloadedIndex(args.type_at(0)))
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
_ => None,
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Helper struct for `explain_captures`.
|
|
struct CapturedMessageOpt {
|
|
is_partial_move: bool,
|
|
is_loop_message: bool,
|
|
is_move_msg: bool,
|
|
is_loop_move: bool,
|
|
has_suggest_reborrow: bool,
|
|
maybe_reinitialized_locations_is_empty: bool,
|
|
}
|
|
|
|
impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
|
|
/// Finds the spans associated to a move or copy of move_place at location.
|
|
pub(super) fn move_spans(
|
|
&self,
|
|
moved_place: PlaceRef<'tcx>, // Could also be an upvar.
|
|
location: Location,
|
|
) -> UseSpans<'tcx> {
|
|
use self::UseSpans::*;
|
|
|
|
let Some(stmt) = self.body[location.block].statements.get(location.statement_index) else {
|
|
return OtherUse(self.body.source_info(location).span);
|
|
};
|
|
|
|
debug!("move_spans: moved_place={:?} location={:?} stmt={:?}", moved_place, location, stmt);
|
|
if let StatementKind::Assign(box (_, Rvalue::Aggregate(kind, places))) = &stmt.kind
|
|
&& let AggregateKind::Closure(def_id, _) | AggregateKind::Coroutine(def_id, _) = **kind
|
|
{
|
|
debug!("move_spans: def_id={:?} places={:?}", def_id, places);
|
|
let def_id = def_id.expect_local();
|
|
if let Some((args_span, closure_kind, capture_kind_span, path_span)) =
|
|
self.closure_span(def_id, moved_place, places)
|
|
{
|
|
return ClosureUse { closure_kind, args_span, capture_kind_span, path_span };
|
|
}
|
|
}
|
|
|
|
// StatementKind::FakeRead only contains a def_id if they are introduced as a result
|
|
// of pattern matching within a closure.
|
|
if let StatementKind::FakeRead(box (cause, place)) = stmt.kind {
|
|
match cause {
|
|
FakeReadCause::ForMatchedPlace(Some(closure_def_id))
|
|
| FakeReadCause::ForLet(Some(closure_def_id)) => {
|
|
debug!("move_spans: def_id={:?} place={:?}", closure_def_id, place);
|
|
let places = &[Operand::Move(place)];
|
|
if let Some((args_span, closure_kind, capture_kind_span, path_span)) =
|
|
self.closure_span(closure_def_id, moved_place, IndexSlice::from_raw(places))
|
|
{
|
|
return ClosureUse {
|
|
closure_kind,
|
|
args_span,
|
|
capture_kind_span,
|
|
path_span,
|
|
};
|
|
}
|
|
}
|
|
_ => {}
|
|
}
|
|
}
|
|
|
|
let normal_ret =
|
|
if moved_place.projection.iter().any(|p| matches!(p, ProjectionElem::Downcast(..))) {
|
|
PatUse(stmt.source_info.span)
|
|
} else {
|
|
OtherUse(stmt.source_info.span)
|
|
};
|
|
|
|
// We are trying to find MIR of the form:
|
|
// ```
|
|
// _temp = _moved_val;
|
|
// ...
|
|
// FnSelfCall(_temp, ...)
|
|
// ```
|
|
//
|
|
// where `_moved_val` is the place we generated the move error for,
|
|
// `_temp` is some other local, and `FnSelfCall` is a function
|
|
// that has a `self` parameter.
|
|
|
|
let target_temp = match stmt.kind {
|
|
StatementKind::Assign(box (temp, _)) if temp.as_local().is_some() => {
|
|
temp.as_local().unwrap()
|
|
}
|
|
_ => return normal_ret,
|
|
};
|
|
|
|
debug!("move_spans: target_temp = {:?}", target_temp);
|
|
|
|
if let Some(Terminator {
|
|
kind: TerminatorKind::Call { fn_span, call_source, .. }, ..
|
|
}) = &self.body[location.block].terminator
|
|
{
|
|
let Some((method_did, method_args)) =
|
|
find_self_call(self.infcx.tcx, self.body, target_temp, location.block)
|
|
else {
|
|
return normal_ret;
|
|
};
|
|
|
|
let kind = call_kind(
|
|
self.infcx.tcx,
|
|
self.infcx.typing_env(self.infcx.param_env),
|
|
method_did,
|
|
method_args,
|
|
*fn_span,
|
|
call_source.from_hir_call(),
|
|
Some(self.infcx.tcx.fn_arg_names(method_did)[0]),
|
|
);
|
|
|
|
return FnSelfUse {
|
|
var_span: stmt.source_info.span,
|
|
fn_call_span: *fn_span,
|
|
fn_span: self.infcx.tcx.def_span(method_did),
|
|
kind,
|
|
};
|
|
}
|
|
|
|
normal_ret
|
|
}
|
|
|
|
/// Finds the span of arguments of a closure (within `maybe_closure_span`)
|
|
/// and its usage of the local assigned at `location`.
|
|
/// This is done by searching in statements succeeding `location`
|
|
/// and originating from `maybe_closure_span`.
|
|
pub(super) fn borrow_spans(&self, use_span: Span, location: Location) -> UseSpans<'tcx> {
|
|
use self::UseSpans::*;
|
|
debug!("borrow_spans: use_span={:?} location={:?}", use_span, location);
|
|
|
|
let target = match self.body[location.block].statements.get(location.statement_index) {
|
|
Some(Statement { kind: StatementKind::Assign(box (place, _)), .. }) => {
|
|
if let Some(local) = place.as_local() {
|
|
local
|
|
} else {
|
|
return OtherUse(use_span);
|
|
}
|
|
}
|
|
_ => return OtherUse(use_span),
|
|
};
|
|
|
|
if self.body.local_kind(target) != LocalKind::Temp {
|
|
// operands are always temporaries.
|
|
return OtherUse(use_span);
|
|
}
|
|
|
|
// drop and replace might have moved the assignment to the next block
|
|
let maybe_additional_statement =
|
|
if let TerminatorKind::Drop { target: drop_target, .. } =
|
|
self.body[location.block].terminator().kind
|
|
{
|
|
self.body[drop_target].statements.first()
|
|
} else {
|
|
None
|
|
};
|
|
|
|
let statements =
|
|
self.body[location.block].statements[location.statement_index + 1..].iter();
|
|
|
|
for stmt in statements.chain(maybe_additional_statement) {
|
|
if let StatementKind::Assign(box (_, Rvalue::Aggregate(kind, places))) = &stmt.kind {
|
|
let (&def_id, is_coroutine) = match kind {
|
|
box AggregateKind::Closure(def_id, _) => (def_id, false),
|
|
box AggregateKind::Coroutine(def_id, _) => (def_id, true),
|
|
_ => continue,
|
|
};
|
|
let def_id = def_id.expect_local();
|
|
|
|
debug!(
|
|
"borrow_spans: def_id={:?} is_coroutine={:?} places={:?}",
|
|
def_id, is_coroutine, places
|
|
);
|
|
if let Some((args_span, closure_kind, capture_kind_span, path_span)) =
|
|
self.closure_span(def_id, Place::from(target).as_ref(), places)
|
|
{
|
|
return ClosureUse { closure_kind, args_span, capture_kind_span, path_span };
|
|
} else {
|
|
return OtherUse(use_span);
|
|
}
|
|
}
|
|
|
|
if use_span != stmt.source_info.span {
|
|
break;
|
|
}
|
|
}
|
|
|
|
OtherUse(use_span)
|
|
}
|
|
|
|
/// Finds the spans of a captured place within a closure or coroutine.
|
|
/// The first span is the location of the use resulting in the capture kind of the capture
|
|
/// The second span is the location the use resulting in the captured path of the capture
|
|
fn closure_span(
|
|
&self,
|
|
def_id: LocalDefId,
|
|
target_place: PlaceRef<'tcx>,
|
|
places: &IndexSlice<FieldIdx, Operand<'tcx>>,
|
|
) -> Option<(Span, hir::ClosureKind, Span, Span)> {
|
|
debug!(
|
|
"closure_span: def_id={:?} target_place={:?} places={:?}",
|
|
def_id, target_place, places
|
|
);
|
|
let hir_id = self.infcx.tcx.local_def_id_to_hir_id(def_id);
|
|
let expr = &self.infcx.tcx.hir_expect_expr(hir_id).kind;
|
|
debug!("closure_span: hir_id={:?} expr={:?}", hir_id, expr);
|
|
if let &hir::ExprKind::Closure(&hir::Closure { kind, fn_decl_span, .. }) = expr {
|
|
for (captured_place, place) in
|
|
self.infcx.tcx.closure_captures(def_id).iter().zip(places)
|
|
{
|
|
match place {
|
|
Operand::Copy(place) | Operand::Move(place)
|
|
if target_place == place.as_ref() =>
|
|
{
|
|
debug!("closure_span: found captured local {:?}", place);
|
|
return Some((
|
|
fn_decl_span,
|
|
kind,
|
|
captured_place.get_capture_kind_span(self.infcx.tcx),
|
|
captured_place.get_path_span(self.infcx.tcx),
|
|
));
|
|
}
|
|
_ => {}
|
|
}
|
|
}
|
|
}
|
|
None
|
|
}
|
|
|
|
/// Helper to retrieve span(s) of given borrow from the current MIR
|
|
/// representation
|
|
pub(super) fn retrieve_borrow_spans(&self, borrow: &BorrowData<'_>) -> UseSpans<'tcx> {
|
|
let span = self.body.source_info(borrow.reserve_location).span;
|
|
self.borrow_spans(span, borrow.reserve_location)
|
|
}
|
|
|
|
#[allow(rustc::diagnostic_outside_of_impl)]
|
|
#[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
|
|
fn explain_captures(
|
|
&mut self,
|
|
err: &mut Diag<'infcx>,
|
|
span: Span,
|
|
move_span: Span,
|
|
move_spans: UseSpans<'tcx>,
|
|
moved_place: Place<'tcx>,
|
|
msg_opt: CapturedMessageOpt,
|
|
) {
|
|
let CapturedMessageOpt {
|
|
is_partial_move: is_partial,
|
|
is_loop_message,
|
|
is_move_msg,
|
|
is_loop_move,
|
|
has_suggest_reborrow,
|
|
maybe_reinitialized_locations_is_empty,
|
|
} = msg_opt;
|
|
if let UseSpans::FnSelfUse { var_span, fn_call_span, fn_span, kind } = move_spans {
|
|
let place_name = self
|
|
.describe_place(moved_place.as_ref())
|
|
.map(|n| format!("`{n}`"))
|
|
.unwrap_or_else(|| "value".to_owned());
|
|
match kind {
|
|
CallKind::FnCall { fn_trait_id, self_ty }
|
|
if self.infcx.tcx.is_lang_item(fn_trait_id, LangItem::FnOnce) =>
|
|
{
|
|
err.subdiagnostic(CaptureReasonLabel::Call {
|
|
fn_call_span,
|
|
place_name: &place_name,
|
|
is_partial,
|
|
is_loop_message,
|
|
});
|
|
// Check if the move occurs on a value because of a call on a closure that comes
|
|
// from a type parameter `F: FnOnce()`. If so, we provide a targeted `note`:
|
|
// ```
|
|
// error[E0382]: use of moved value: `blk`
|
|
// --> $DIR/once-cant-call-twice-on-heap.rs:8:5
|
|
// |
|
|
// LL | fn foo<F:FnOnce()>(blk: F) {
|
|
// | --- move occurs because `blk` has type `F`, which does not implement the `Copy` trait
|
|
// LL | blk();
|
|
// | ----- `blk` moved due to this call
|
|
// LL | blk();
|
|
// | ^^^ value used here after move
|
|
// |
|
|
// note: `FnOnce` closures can only be called once
|
|
// --> $DIR/once-cant-call-twice-on-heap.rs:6:10
|
|
// |
|
|
// LL | fn foo<F:FnOnce()>(blk: F) {
|
|
// | ^^^^^^^^ `F` is made to be an `FnOnce` closure here
|
|
// LL | blk();
|
|
// | ----- this value implements `FnOnce`, which causes it to be moved when called
|
|
// ```
|
|
if let ty::Param(param_ty) = *self_ty.kind()
|
|
&& let generics = self.infcx.tcx.generics_of(self.mir_def_id())
|
|
&& let param = generics.type_param(param_ty, self.infcx.tcx)
|
|
&& let Some(hir_generics) = self
|
|
.infcx
|
|
.tcx
|
|
.typeck_root_def_id(self.mir_def_id().to_def_id())
|
|
.as_local()
|
|
.and_then(|def_id| self.infcx.tcx.hir_get_generics(def_id))
|
|
&& let spans = hir_generics
|
|
.predicates
|
|
.iter()
|
|
.filter_map(|pred| match pred.kind {
|
|
hir::WherePredicateKind::BoundPredicate(pred) => Some(pred),
|
|
_ => None,
|
|
})
|
|
.filter(|pred| {
|
|
if let Some((id, _)) = pred.bounded_ty.as_generic_param() {
|
|
id == param.def_id
|
|
} else {
|
|
false
|
|
}
|
|
})
|
|
.flat_map(|pred| pred.bounds)
|
|
.filter_map(|bound| {
|
|
if let Some(trait_ref) = bound.trait_ref()
|
|
&& let Some(trait_def_id) = trait_ref.trait_def_id()
|
|
&& trait_def_id == fn_trait_id
|
|
{
|
|
Some(bound.span())
|
|
} else {
|
|
None
|
|
}
|
|
})
|
|
.collect::<Vec<Span>>()
|
|
&& !spans.is_empty()
|
|
{
|
|
let mut span: MultiSpan = spans.clone().into();
|
|
for sp in spans {
|
|
span.push_span_label(sp, fluent::borrowck_moved_a_fn_once_in_call_def);
|
|
}
|
|
span.push_span_label(
|
|
fn_call_span,
|
|
fluent::borrowck_moved_a_fn_once_in_call,
|
|
);
|
|
err.span_note(span, fluent::borrowck_moved_a_fn_once_in_call_call);
|
|
} else {
|
|
err.subdiagnostic(CaptureReasonNote::FnOnceMoveInCall { var_span });
|
|
}
|
|
}
|
|
CallKind::Operator { self_arg, trait_id, .. } => {
|
|
let self_arg = self_arg.unwrap();
|
|
err.subdiagnostic(CaptureReasonLabel::OperatorUse {
|
|
fn_call_span,
|
|
place_name: &place_name,
|
|
is_partial,
|
|
is_loop_message,
|
|
});
|
|
if self.fn_self_span_reported.insert(fn_span) {
|
|
let lang = self.infcx.tcx.lang_items();
|
|
err.subdiagnostic(
|
|
if [lang.not_trait(), lang.deref_trait(), lang.neg_trait()]
|
|
.contains(&Some(trait_id))
|
|
{
|
|
CaptureReasonNote::UnOpMoveByOperator { span: self_arg.span }
|
|
} else {
|
|
CaptureReasonNote::LhsMoveByOperator { span: self_arg.span }
|
|
},
|
|
);
|
|
}
|
|
}
|
|
CallKind::Normal { self_arg, desugaring, method_did, method_args } => {
|
|
let self_arg = self_arg.unwrap();
|
|
let mut has_sugg = false;
|
|
let tcx = self.infcx.tcx;
|
|
// Avoid pointing to the same function in multiple different
|
|
// error messages.
|
|
if span != DUMMY_SP && self.fn_self_span_reported.insert(self_arg.span) {
|
|
self.explain_iterator_advancement_in_for_loop_if_applicable(
|
|
err,
|
|
span,
|
|
&move_spans,
|
|
);
|
|
|
|
let func = tcx.def_path_str(method_did);
|
|
err.subdiagnostic(CaptureReasonNote::FuncTakeSelf {
|
|
func,
|
|
place_name: place_name.clone(),
|
|
span: self_arg.span,
|
|
});
|
|
}
|
|
let parent_did = tcx.parent(method_did);
|
|
let parent_self_ty =
|
|
matches!(tcx.def_kind(parent_did), rustc_hir::def::DefKind::Impl { .. })
|
|
.then_some(parent_did)
|
|
.and_then(|did| match tcx.type_of(did).instantiate_identity().kind() {
|
|
ty::Adt(def, ..) => Some(def.did()),
|
|
_ => None,
|
|
});
|
|
let is_option_or_result = parent_self_ty.is_some_and(|def_id| {
|
|
matches!(tcx.get_diagnostic_name(def_id), Some(sym::Option | sym::Result))
|
|
});
|
|
if is_option_or_result && maybe_reinitialized_locations_is_empty {
|
|
err.subdiagnostic(CaptureReasonLabel::BorrowContent { var_span });
|
|
}
|
|
if let Some((CallDesugaringKind::ForLoopIntoIter, _)) = desugaring {
|
|
let ty = moved_place.ty(self.body, tcx).ty;
|
|
let suggest = match tcx.get_diagnostic_item(sym::IntoIterator) {
|
|
Some(def_id) => type_known_to_meet_bound_modulo_regions(
|
|
self.infcx,
|
|
self.infcx.param_env,
|
|
Ty::new_imm_ref(tcx, tcx.lifetimes.re_erased, ty),
|
|
def_id,
|
|
),
|
|
_ => false,
|
|
};
|
|
if suggest {
|
|
err.subdiagnostic(CaptureReasonSuggest::IterateSlice {
|
|
ty,
|
|
span: move_span.shrink_to_lo(),
|
|
});
|
|
}
|
|
|
|
err.subdiagnostic(CaptureReasonLabel::ImplicitCall {
|
|
fn_call_span,
|
|
place_name: &place_name,
|
|
is_partial,
|
|
is_loop_message,
|
|
});
|
|
// If the moved place was a `&mut` ref, then we can
|
|
// suggest to reborrow it where it was moved, so it
|
|
// will still be valid by the time we get to the usage.
|
|
if let ty::Ref(_, _, hir::Mutability::Mut) =
|
|
moved_place.ty(self.body, self.infcx.tcx).ty.kind()
|
|
{
|
|
// Suggest `reborrow` in other place for following situations:
|
|
// 1. If we are in a loop this will be suggested later.
|
|
// 2. If the moved value is a mut reference, it is used in a
|
|
// generic function and the corresponding arg's type is generic param.
|
|
if !is_loop_move && !has_suggest_reborrow {
|
|
self.suggest_reborrow(
|
|
err,
|
|
move_span.shrink_to_lo(),
|
|
moved_place.as_ref(),
|
|
);
|
|
}
|
|
}
|
|
} else {
|
|
if let Some((CallDesugaringKind::Await, _)) = desugaring {
|
|
err.subdiagnostic(CaptureReasonLabel::Await {
|
|
fn_call_span,
|
|
place_name: &place_name,
|
|
is_partial,
|
|
is_loop_message,
|
|
});
|
|
} else {
|
|
err.subdiagnostic(CaptureReasonLabel::MethodCall {
|
|
fn_call_span,
|
|
place_name: &place_name,
|
|
is_partial,
|
|
is_loop_message,
|
|
});
|
|
}
|
|
// Erase and shadow everything that could be passed to the new infcx.
|
|
let ty = moved_place.ty(self.body, tcx).ty;
|
|
|
|
if let ty::Adt(def, args) = ty.peel_refs().kind()
|
|
&& tcx.is_lang_item(def.did(), LangItem::Pin)
|
|
&& let ty::Ref(_, _, hir::Mutability::Mut) = args.type_at(0).kind()
|
|
&& let self_ty = self.infcx.instantiate_binder_with_fresh_vars(
|
|
fn_call_span,
|
|
BoundRegionConversionTime::FnCall,
|
|
tcx.fn_sig(method_did).instantiate(tcx, method_args).input(0),
|
|
)
|
|
&& self.infcx.can_eq(self.infcx.param_env, ty, self_ty)
|
|
{
|
|
err.subdiagnostic(CaptureReasonSuggest::FreshReborrow {
|
|
span: move_span.shrink_to_hi(),
|
|
});
|
|
has_sugg = true;
|
|
}
|
|
if let Some(clone_trait) = tcx.lang_items().clone_trait() {
|
|
let sugg = if moved_place
|
|
.iter_projections()
|
|
.any(|(_, elem)| matches!(elem, ProjectionElem::Deref))
|
|
{
|
|
let (start, end) = if let Some(expr) = self.find_expr(move_span)
|
|
&& let Some(_) = self.clone_on_reference(expr)
|
|
&& let hir::ExprKind::MethodCall(_, rcvr, _, _) = expr.kind
|
|
{
|
|
(move_span.shrink_to_lo(), move_span.with_lo(rcvr.span.hi()))
|
|
} else {
|
|
(move_span.shrink_to_lo(), move_span.shrink_to_hi())
|
|
};
|
|
vec![
|
|
// We use the fully-qualified path because `.clone()` can
|
|
// sometimes choose `<&T as Clone>` instead of `<T as Clone>`
|
|
// when going through auto-deref, so this ensures that doesn't
|
|
// happen, causing suggestions for `.clone().clone()`.
|
|
(start, format!("<{ty} as Clone>::clone(&")),
|
|
(end, ")".to_string()),
|
|
]
|
|
} else {
|
|
vec![(move_span.shrink_to_hi(), ".clone()".to_string())]
|
|
};
|
|
if let Some(errors) = self.infcx.type_implements_trait_shallow(
|
|
clone_trait,
|
|
ty,
|
|
self.infcx.param_env,
|
|
) && !has_sugg
|
|
{
|
|
let msg = match &errors[..] {
|
|
[] => "you can `clone` the value and consume it, but this \
|
|
might not be your desired behavior"
|
|
.to_string(),
|
|
[error] => {
|
|
format!(
|
|
"you could `clone` the value and consume it, if the \
|
|
`{}` trait bound could be satisfied",
|
|
error.obligation.predicate,
|
|
)
|
|
}
|
|
_ => {
|
|
format!(
|
|
"you could `clone` the value and consume it, if the \
|
|
following trait bounds could be satisfied: {}",
|
|
listify(&errors, |e: &FulfillmentError<'tcx>| format!(
|
|
"`{}`",
|
|
e.obligation.predicate
|
|
))
|
|
.unwrap(),
|
|
)
|
|
}
|
|
};
|
|
err.multipart_suggestion_verbose(
|
|
msg,
|
|
sugg,
|
|
Applicability::MaybeIncorrect,
|
|
);
|
|
for error in errors {
|
|
if let FulfillmentErrorCode::Select(
|
|
SelectionError::Unimplemented,
|
|
) = error.code
|
|
&& let ty::PredicateKind::Clause(ty::ClauseKind::Trait(
|
|
pred,
|
|
)) = error.obligation.predicate.kind().skip_binder()
|
|
{
|
|
self.infcx.err_ctxt().suggest_derive(
|
|
&error.obligation,
|
|
err,
|
|
error.obligation.predicate.kind().rebind(pred),
|
|
);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
// Other desugarings takes &self, which cannot cause a move
|
|
_ => {}
|
|
}
|
|
} else {
|
|
if move_span != span || is_loop_message {
|
|
err.subdiagnostic(CaptureReasonLabel::MovedHere {
|
|
move_span,
|
|
is_partial,
|
|
is_move_msg,
|
|
is_loop_message,
|
|
});
|
|
}
|
|
// If the move error occurs due to a loop, don't show
|
|
// another message for the same span
|
|
if !is_loop_message {
|
|
move_spans.var_subdiag(err, None, |kind, var_span| match kind {
|
|
hir::ClosureKind::Coroutine(_) => {
|
|
CaptureVarCause::PartialMoveUseInCoroutine { var_span, is_partial }
|
|
}
|
|
hir::ClosureKind::Closure | hir::ClosureKind::CoroutineClosure(_) => {
|
|
CaptureVarCause::PartialMoveUseInClosure { var_span, is_partial }
|
|
}
|
|
})
|
|
}
|
|
}
|
|
}
|
|
}
|