diff options
Diffstat (limited to 'compiler/rustc_hir_typeck/src/demand.rs')
| -rw-r--r-- | compiler/rustc_hir_typeck/src/demand.rs | 425 |
1 files changed, 400 insertions, 25 deletions
diff --git a/compiler/rustc_hir_typeck/src/demand.rs b/compiler/rustc_hir_typeck/src/demand.rs index 24184bdbf..f4c4d4310 100644 --- a/compiler/rustc_hir_typeck/src/demand.rs +++ b/compiler/rustc_hir_typeck/src/demand.rs @@ -1,5 +1,6 @@ use crate::FnCtxt; use rustc_ast::util::parser::PREC_POSTFIX; +use rustc_errors::MultiSpan; use rustc_errors::{Applicability, Diagnostic, DiagnosticBuilder, ErrorGuaranteed}; use rustc_hir as hir; use rustc_hir::def::CtorKind; @@ -23,7 +24,7 @@ use std::cmp::min; use std::iter; impl<'a, 'tcx> FnCtxt<'a, 'tcx> { - pub fn emit_coerce_suggestions( + pub fn emit_type_mismatch_suggestions( &self, err: &mut Diagnostic, expr: &hir::Expr<'tcx>, @@ -36,11 +37,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { return; } - self.annotate_expected_due_to_let_ty(err, expr, error); + self.annotate_alternative_method_deref(err, expr, error); // Use `||` to give these suggestions a precedence let _ = self.suggest_missing_parentheses(err, expr) + || self.suggest_remove_last_method_call(err, expr, expected) + || self.suggest_associated_const(err, expr, expected) || self.suggest_deref_ref_or_into(err, expr, expected, expr_ty, expected_ty_expr) + || self.suggest_option_to_bool(err, expr, expr_ty, expected) || self.suggest_compatible_variants(err, expr, expected, expr_ty) || self.suggest_non_zero_new_unwrap(err, expr, expected, expr_ty) || self.suggest_calling_boxed_future_when_appropriate(err, expr, expected, expr_ty) @@ -48,13 +52,32 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { || self.suggest_boxing_when_appropriate(err, expr, expected, expr_ty) || self.suggest_block_to_brackets_peeling_refs(err, expr, expr_ty, expected) || self.suggest_copied_or_cloned(err, expr, expr_ty, expected) + || self.suggest_clone_for_ref(err, expr, expr_ty, expected) || self.suggest_into(err, expr, expr_ty, expected) - || self.suggest_option_to_bool(err, expr, expr_ty, expected) || self.suggest_floating_point_literal(err, expr, expected); + } + pub fn emit_coerce_suggestions( + &self, + err: &mut Diagnostic, + expr: &hir::Expr<'tcx>, + expr_ty: Ty<'tcx>, + expected: Ty<'tcx>, + expected_ty_expr: Option<&'tcx hir::Expr<'tcx>>, + error: Option<TypeError<'tcx>>, + ) { + if expr_ty == expected { + return; + } + + self.annotate_expected_due_to_let_ty(err, expr, error); + self.emit_type_mismatch_suggestions(err, expr, expr_ty, expected, expected_ty_expr, error); self.note_type_is_not_clone(err, expected, expr_ty, expr); self.note_need_for_fn_pointer(err, expected, expr_ty); self.note_internal_mutation_in_method(err, expr, expected, expr_ty); + self.check_for_range_as_method_call(err, expr, expr_ty, expected); + self.check_for_binding_assigned_block_without_tail_expression(err, expr, expr_ty, expected); + self.check_wrong_return_type_due_to_generic_arg(err, expr, expr_ty); } /// Requires that the two types unify, and prints an error message if @@ -163,7 +186,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { let expr = expr.peel_drop_temps(); let cause = self.misc(expr.span); let expr_ty = self.resolve_vars_with_obligations(checked_ty); - let mut err = self.err_ctxt().report_mismatched_types(&cause, expected, expr_ty, e.clone()); + let mut err = self.err_ctxt().report_mismatched_types(&cause, expected, expr_ty, e); let is_insufficiently_polymorphic = matches!(e, TypeError::RegionsInsufficientlyPolymorphic(..)); @@ -189,9 +212,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { &self, err: &mut Diagnostic, expr: &hir::Expr<'_>, - error: Option<TypeError<'_>>, + error: Option<TypeError<'tcx>>, ) { - let parent = self.tcx.hir().get_parent_node(expr.hir_id); + let parent = self.tcx.hir().parent_id(expr.hir_id); match (self.tcx.hir().find(parent), error) { (Some(hir::Node::Local(hir::Local { ty: Some(ty), init: Some(init), .. })), _) if init.hir_id == expr.hir_id => @@ -238,10 +261,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { hir::Path { res: hir::def::Res::Local(hir_id), .. }, )) => { if let Some(hir::Node::Pat(pat)) = self.tcx.hir().find(*hir_id) { - let parent = self.tcx.hir().get_parent_node(pat.hir_id); primary_span = pat.span; secondary_span = pat.span; - match self.tcx.hir().find(parent) { + match self.tcx.hir().find_parent(pat.hir_id) { Some(hir::Node::Local(hir::Local { ty: Some(ty), .. })) => { primary_span = ty.span; post_message = " type"; @@ -286,10 +308,177 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { err.downgrade_to_delayed_bug(); } } + ( + Some(hir::Node::Expr(hir::Expr { + kind: hir::ExprKind::Binary(_, lhs, rhs), .. + })), + Some(TypeError::Sorts(ExpectedFound { expected, .. })), + ) if rhs.hir_id == expr.hir_id + && self.typeck_results.borrow().expr_ty_adjusted_opt(lhs) == Some(expected) => + { + err.span_label(lhs.span, &format!("expected because this is `{expected}`")); + } _ => {} } } + fn annotate_alternative_method_deref( + &self, + err: &mut Diagnostic, + expr: &hir::Expr<'_>, + error: Option<TypeError<'tcx>>, + ) { + let parent = self.tcx.hir().parent_id(expr.hir_id); + let Some(TypeError::Sorts(ExpectedFound { expected, .. })) = error else {return;}; + let Some(hir::Node::Expr(hir::Expr { + kind: hir::ExprKind::Assign(lhs, rhs, _), .. + })) = self.tcx.hir().find(parent) else {return; }; + if rhs.hir_id != expr.hir_id || expected.is_closure() { + return; + } + let hir::ExprKind::Unary(hir::UnOp::Deref, deref) = lhs.kind else { return; }; + let hir::ExprKind::MethodCall(path, base, args, _) = deref.kind else { return; }; + let Some(self_ty) = self.typeck_results.borrow().expr_ty_adjusted_opt(base) else { return; }; + + let Ok(pick) = self + .lookup_probe_for_diagnostic( + path.ident, + self_ty, + deref, + probe::ProbeScope::TraitsInScope, + None, + ) else { + return; + }; + let in_scope_methods = self.probe_for_name_many( + probe::Mode::MethodCall, + path.ident, + Some(expected), + probe::IsSuggestion(true), + self_ty, + deref.hir_id, + probe::ProbeScope::TraitsInScope, + ); + let other_methods_in_scope: Vec<_> = + in_scope_methods.iter().filter(|c| c.item.def_id != pick.item.def_id).collect(); + + let all_methods = self.probe_for_name_many( + probe::Mode::MethodCall, + path.ident, + Some(expected), + probe::IsSuggestion(true), + self_ty, + deref.hir_id, + probe::ProbeScope::AllTraits, + ); + let suggestions: Vec<_> = all_methods + .into_iter() + .filter(|c| c.item.def_id != pick.item.def_id) + .map(|c| { + let m = c.item; + let substs = ty::InternalSubsts::for_item(self.tcx, m.def_id, |param, _| { + self.var_for_def(deref.span, param) + }); + vec![ + ( + deref.span.until(base.span), + format!( + "{}({}", + with_no_trimmed_paths!( + self.tcx.def_path_str_with_substs(m.def_id, substs,) + ), + match self.tcx.fn_sig(m.def_id).input(0).skip_binder().kind() { + ty::Ref(_, _, hir::Mutability::Mut) => "&mut ", + ty::Ref(_, _, _) => "&", + _ => "", + }, + ), + ), + match &args[..] { + [] => (base.span.shrink_to_hi().with_hi(deref.span.hi()), ")".to_string()), + [first, ..] => (base.span.between(first.span), ", ".to_string()), + }, + ] + }) + .collect(); + if suggestions.is_empty() { + return; + } + let mut path_span: MultiSpan = path.ident.span.into(); + path_span.push_span_label( + path.ident.span, + with_no_trimmed_paths!(format!( + "refers to `{}`", + self.tcx.def_path_str(pick.item.def_id), + )), + ); + let container_id = pick.item.container_id(self.tcx); + let container = with_no_trimmed_paths!(self.tcx.def_path_str(container_id)); + for def_id in pick.import_ids { + let hir_id = self.tcx.hir().local_def_id_to_hir_id(def_id); + path_span.push_span_label( + self.tcx.hir().span(hir_id), + format!("`{container}` imported here"), + ); + } + let tail = with_no_trimmed_paths!(match &other_methods_in_scope[..] { + [] => return, + [candidate] => format!( + "the method of the same name on {} `{}`", + match candidate.kind { + probe::CandidateKind::InherentImplCandidate(..) => "the inherent impl for", + _ => "trait", + }, + self.tcx.def_path_str(candidate.item.container_id(self.tcx)) + ), + [.., last] if other_methods_in_scope.len() < 5 => { + format!( + "the methods of the same name on {} and `{}`", + other_methods_in_scope[..other_methods_in_scope.len() - 1] + .iter() + .map(|c| format!( + "`{}`", + self.tcx.def_path_str(c.item.container_id(self.tcx)) + )) + .collect::<Vec<String>>() + .join(", "), + self.tcx.def_path_str(last.item.container_id(self.tcx)) + ) + } + _ => format!( + "the methods of the same name on {} other traits", + other_methods_in_scope.len() + ), + }); + err.span_note( + path_span, + &format!( + "the `{}` call is resolved to the method in `{container}`, shadowing {tail}", + path.ident, + ), + ); + if suggestions.len() > other_methods_in_scope.len() { + err.note(&format!( + "additionally, there are {} other available methods that aren't in scope", + suggestions.len() - other_methods_in_scope.len() + )); + } + err.multipart_suggestions( + &format!( + "you might have meant to call {}; you can use the fully-qualified path to call {} \ + explicitly", + if suggestions.len() == 1 { + "the other method" + } else { + "one of the other methods" + }, + if suggestions.len() == 1 { "it" } else { "one of them" }, + ), + suggestions, + Applicability::MaybeIncorrect, + ); + } + /// If the expected type is an enum (Issue #55250) with any variants whose /// sole field is of the found type, suggest such variants. (Issue #42764) fn suggest_compatible_variants( @@ -324,7 +513,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { // Unroll desugaring, to make sure this works for `for` loops etc. loop { - parent = self.tcx.hir().get_parent_node(id); + parent = self.tcx.hir().parent_id(id); if let Some(parent_span) = self.tcx.hir().opt_span(parent) { if parent_span.find_ancestor_inside(expr.span).is_some() { // The parent node is part of the same span, so is the result of the @@ -396,7 +585,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { } let note_about_variant_field_privacy = (field_is_local && !field_is_accessible) - .then(|| format!(" (its field is private, but it's local to this crate and its privacy can be changed)")); + .then(|| " (its field is private, but it's local to this crate and its privacy can be changed)".to_string()); let sole_field_ty = sole_field.ty(self.tcx, substs); if self.can_coerce(expr_ty, sole_field_ty) { @@ -604,12 +793,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { return None; }; - let local_parent = self.tcx.hir().get_parent_node(local_id); + let local_parent = self.tcx.hir().parent_id(local_id); let Some(Node::Param(hir::Param { hir_id: param_hir_id, .. })) = self.tcx.hir().find(local_parent) else { return None; }; - let param_parent = self.tcx.hir().get_parent_node(*param_hir_id); + let param_parent = self.tcx.hir().parent_id(*param_hir_id); let Some(Node::Expr(hir::Expr { hir_id: expr_hir_id, kind: hir::ExprKind::Closure(hir::Closure { fn_decl: closure_fn_decl, .. }), @@ -618,7 +807,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { return None; }; - let expr_parent = self.tcx.hir().get_parent_node(*expr_hir_id); + let expr_parent = self.tcx.hir().parent_id(*expr_hir_id); let hir = self.tcx.hir().find(expr_parent); let closure_params_len = closure_fn_decl.inputs.len(); let ( @@ -671,7 +860,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { _ => None, }?; - match hir.find(hir.get_parent_node(expr.hir_id))? { + match hir.find_parent(expr.hir_id)? { Node::ExprField(field) => { if field.ident.name == local.name && field.is_shorthand { return Some(local.name); @@ -697,7 +886,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { /// Returns whether the given expression is an `else if`. pub(crate) fn is_else_if_block(&self, expr: &hir::Expr<'_>) -> bool { if let hir::ExprKind::If(..) = expr.kind { - let parent_id = self.tcx.hir().get_parent_node(expr.hir_id); + let parent_id = self.tcx.hir().parent_id(expr.hir_id); if let Some(Node::Expr(hir::Expr { kind: hir::ExprKind::If(_, _, Some(else_expr)), .. @@ -854,7 +1043,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { if let Some(hir::Node::Expr(hir::Expr { kind: hir::ExprKind::Assign(..), .. - })) = self.tcx.hir().find(self.tcx.hir().get_parent_node(expr.hir_id)) + })) = self.tcx.hir().find_parent(expr.hir_id) { if mutability.is_mut() { // Suppressing this diagnostic, we'll properly print it in `check_expr_assign` @@ -976,7 +1165,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { } } // If we've reached our target type with just removing `&`, then just print now. - if steps == 0 { + if steps == 0 && !remove.trim().is_empty() { return Some(( prefix_span, format!("consider removing the `{}`", remove.trim()), @@ -1035,6 +1224,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { } else { (prefix_span, format!("{}{}", prefix, "*".repeat(steps))) }; + if suggestion.trim().is_empty() { + return None; + } return Some(( span, @@ -1081,9 +1273,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { let mut sugg = vec![]; - if let Some(hir::Node::ExprField(field)) = - self.tcx.hir().find(self.tcx.hir().get_parent_node(expr.hir_id)) - { + if let Some(hir::Node::ExprField(field)) = self.tcx.hir().find_parent(expr.hir_id) { // `expr` is a literal field for a struct, only suggest if appropriate if field.is_shorthand { // This is a field literal @@ -1265,7 +1455,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { }; match (&expected_ty.kind(), &checked_ty.kind()) { - (&ty::Int(ref exp), &ty::Int(ref found)) => { + (ty::Int(exp), ty::Int(found)) => { let (f2e_is_fallible, e2f_is_fallible) = match (exp.bit_width(), found.bit_width()) { (Some(exp), Some(found)) if exp < found => (true, false), @@ -1278,7 +1468,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { suggest_to_change_suffix_or_into(err, f2e_is_fallible, e2f_is_fallible); true } - (&ty::Uint(ref exp), &ty::Uint(ref found)) => { + (ty::Uint(exp), ty::Uint(found)) => { let (f2e_is_fallible, e2f_is_fallible) = match (exp.bit_width(), found.bit_width()) { (Some(exp), Some(found)) if exp < found => (true, false), @@ -1311,7 +1501,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { suggest_to_change_suffix_or_into(err, f2e_is_fallible, e2f_is_fallible); true } - (&ty::Float(ref exp), &ty::Float(ref found)) => { + (ty::Float(exp), ty::Float(found)) => { if found.bit_width() < exp.bit_width() { suggest_to_change_suffix_or_into(err, false, true); } else if literal_is_ty_suffixed(expr) { @@ -1347,7 +1537,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { } true } - (&ty::Float(ref exp), &ty::Uint(ref found)) => { + (ty::Float(exp), ty::Uint(found)) => { // if `found` is `None` (meaning found is `usize`), don't suggest `.into()` if exp.bit_width() > found.bit_width().unwrap_or(256) { err.multipart_suggestion_verbose( @@ -1376,7 +1566,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { } true } - (&ty::Float(ref exp), &ty::Int(ref found)) => { + (ty::Float(exp), ty::Int(found)) => { // if `found` is `None` (meaning found is `isize`), don't suggest `.into()` if exp.bit_width() > found.bit_width().unwrap_or(256) { err.multipart_suggestion_verbose( @@ -1422,4 +1612,189 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { _ => false, } } + + /// Identify when the user has written `foo..bar()` instead of `foo.bar()`. + pub fn check_for_range_as_method_call( + &self, + err: &mut Diagnostic, + expr: &hir::Expr<'tcx>, + checked_ty: Ty<'tcx>, + expected_ty: Ty<'tcx>, + ) { + if !hir::is_range_literal(expr) { + return; + } + let hir::ExprKind::Struct( + hir::QPath::LangItem(LangItem::Range, ..), + [start, end], + _, + ) = expr.kind else { return; }; + let parent = self.tcx.hir().parent_id(expr.hir_id); + if let Some(hir::Node::ExprField(_)) = self.tcx.hir().find(parent) { + // Ignore `Foo { field: a..Default::default() }` + return; + } + let mut expr = end.expr; + let mut expectation = Some(expected_ty); + while let hir::ExprKind::MethodCall(_, rcvr, ..) = expr.kind { + // Getting to the root receiver and asserting it is a fn call let's us ignore cases in + // `tests/ui/methods/issues/issue-90315.stderr`. + expr = rcvr; + // If we have more than one layer of calls, then the expected ty + // cannot guide the method probe. + expectation = None; + } + let hir::ExprKind::Call(method_name, _) = expr.kind else { return; }; + let ty::Adt(adt, _) = checked_ty.kind() else { return; }; + if self.tcx.lang_items().range_struct() != Some(adt.did()) { + return; + } + if let ty::Adt(adt, _) = expected_ty.kind() + && self.tcx.lang_items().range_struct() == Some(adt.did()) + { + return; + } + // Check if start has method named end. + let hir::ExprKind::Path(hir::QPath::Resolved(None, p)) = method_name.kind else { return; }; + let [hir::PathSegment { ident, .. }] = p.segments else { return; }; + let self_ty = self.typeck_results.borrow().expr_ty(start.expr); + let Ok(_pick) = self.lookup_probe_for_diagnostic( + *ident, + self_ty, + expr, + probe::ProbeScope::AllTraits, + expectation, + ) else { return; }; + let mut sugg = "."; + let mut span = start.expr.span.between(end.expr.span); + if span.lo() + BytePos(2) == span.hi() { + // There's no space between the start, the range op and the end, suggest removal which + // will be more noticeable than the replacement of `..` with `.`. + span = span.with_lo(span.lo() + BytePos(1)); + sugg = ""; + } + err.span_suggestion_verbose( + span, + "you likely meant to write a method call instead of a range", + sugg, + Applicability::MachineApplicable, + ); + } + + /// Identify when the type error is because `()` is found in a binding that was assigned a + /// block without a tail expression. + fn check_for_binding_assigned_block_without_tail_expression( + &self, + err: &mut Diagnostic, + expr: &hir::Expr<'_>, + checked_ty: Ty<'tcx>, + expected_ty: Ty<'tcx>, + ) { + if !checked_ty.is_unit() { + return; + } + let hir::ExprKind::Path(hir::QPath::Resolved(None, path)) = expr.kind else { return; }; + let hir::def::Res::Local(hir_id) = path.res else { return; }; + let Some(hir::Node::Pat(pat)) = self.tcx.hir().find(hir_id) else { + return; + }; + let Some(hir::Node::Local(hir::Local { + ty: None, + init: Some(init), + .. + })) = self.tcx.hir().find_parent(pat.hir_id) else { return; }; + let hir::ExprKind::Block(block, None) = init.kind else { return; }; + if block.expr.is_some() { + return; + } + let [.., stmt] = block.stmts else { + err.span_label(block.span, "this empty block is missing a tail expression"); + return; + }; + let hir::StmtKind::Semi(tail_expr) = stmt.kind else { return; }; + let Some(ty) = self.node_ty_opt(tail_expr.hir_id) else { return; }; + if self.can_eq(self.param_env, expected_ty, ty).is_ok() { + err.span_suggestion_short( + stmt.span.with_lo(tail_expr.span.hi()), + "remove this semicolon", + "", + Applicability::MachineApplicable, + ); + } else { + err.span_label(block.span, "this block is missing a tail expression"); + } + } + + fn check_wrong_return_type_due_to_generic_arg( + &self, + err: &mut Diagnostic, + expr: &hir::Expr<'_>, + checked_ty: Ty<'tcx>, + ) { + let Some(hir::Node::Expr(parent_expr)) = self.tcx.hir().find_parent(expr.hir_id) else { return; }; + enum CallableKind { + Function, + Method, + Constructor, + } + let mut maybe_emit_help = |def_id: hir::def_id::DefId, + callable: rustc_span::symbol::Ident, + args: &[hir::Expr<'_>], + kind: CallableKind| { + let arg_idx = args.iter().position(|a| a.hir_id == expr.hir_id).unwrap(); + let fn_ty = self.tcx.bound_type_of(def_id).0; + if !fn_ty.is_fn() { + return; + } + let fn_sig = fn_ty.fn_sig(self.tcx).skip_binder(); + let Some(&arg) = fn_sig.inputs().get(arg_idx + if matches!(kind, CallableKind::Method) { 1 } else { 0 }) else { return; }; + if matches!(arg.kind(), ty::Param(_)) + && fn_sig.output().contains(arg) + && self.node_ty(args[arg_idx].hir_id) == checked_ty + { + let mut multi_span: MultiSpan = parent_expr.span.into(); + multi_span.push_span_label( + args[arg_idx].span, + format!( + "this argument influences the {} of `{}`", + if matches!(kind, CallableKind::Constructor) { + "type" + } else { + "return type" + }, + callable + ), + ); + err.span_help( + multi_span, + format!( + "the {} `{}` due to the type of the argument passed", + match kind { + CallableKind::Function => "return type of this call is", + CallableKind::Method => "return type of this call is", + CallableKind::Constructor => "type constructed contains", + }, + checked_ty + ), + ); + } + }; + match parent_expr.kind { + hir::ExprKind::Call(fun, args) => { + let hir::ExprKind::Path(hir::QPath::Resolved(_, path)) = fun.kind else { return; }; + let hir::def::Res::Def(kind, def_id) = path.res else { return; }; + let callable_kind = if matches!(kind, hir::def::DefKind::Ctor(_, _)) { + CallableKind::Constructor + } else { + CallableKind::Function + }; + maybe_emit_help(def_id, path.segments[0].ident, args, callable_kind); + } + hir::ExprKind::MethodCall(method, _receiver, args, _span) => { + let Some(def_id) = self.typeck_results.borrow().type_dependent_def_id(parent_expr.hir_id) else { return; }; + maybe_emit_help(def_id, method.ident, args, CallableKind::Method) + } + _ => return, + } + } } |