Recurse over the method chain and maintain a stack to peek at previou… · rust-lang/rust@56a109d (original) (raw)
`@@ -481,7 +481,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
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`);
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` probe.is_ok()
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`});
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``
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`self.note_internal_mutation_in_method(
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`&mut err,
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` rcvr_expr,
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`@@ -1240,7 +1239,40 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
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`}
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`}
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`}
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-
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// If an appropriate error source is not found, check method chain for possible candiates
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if unsatisfied_predicates.is_empty() && let Mode::MethodCall = mode && let SelfSource::MethodCall(mut source_expr) = source {
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let mut stack_methods = vec![];
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while let hir::ExprKind::MethodCall(_path_segment, rcvr_expr, _args, method_span) =
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source_expr.kind
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{
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// Pop the matching receiver, to align on it's notional span
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if let Some(prev_match) = stack_methods.pop() {
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err.span_label(method_span, format!("{item_kind} {item_name} is available on {prev_match}"));
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}
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let rcvr_ty = self.resolve_vars_if_possible(
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self.typeck_results
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.borrow()
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.expr_ty_adjusted_opt(rcvr_expr)
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.unwrap_or(Ty::new_misc_error(self.tcx)),);
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for _matched_method in self.probe_for_name_many(
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Mode::MethodCall,
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item_name,
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None,
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IsSuggestion(true),
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rcvr_ty,
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source_expr.hir_id,
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ProbeScope::TraitsInScope,) {
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// found a match, push to stack
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stack_methods.push(rcvr_ty);
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}
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source_expr = rcvr_expr;
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}
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// If there is a match at the start of the chain, add a label for it too!
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if let Some(prev_match) = stack_methods.pop() {
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err.span_label(source_expr.span, format!("{item_kind} {item_name} is available on {prev_match}"));
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}
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}
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`self.note_derefed_ty_has_method(&mut err, source, rcvr_ty, item_name, expected);
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`return Some(err);
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`}
`