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Rollup merge of rust-lang#124283 - surechen:fix_123558, r=estebank
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Note for E0599 if shadowed bindings has the method.

implement rust-lang#123558

Use a visitor to find earlier shadowed bingings which has the method.

r? `@estebank`
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matthiaskrgr authored May 20, 2024
2 parents 59a4f7c + b092b5d commit 98bec6e
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Showing 7 changed files with 249 additions and 6 deletions.
1 change: 1 addition & 0 deletions compiler/rustc_hir_typeck/src/expr.rs
Original file line number Diff line number Diff line change
Expand Up @@ -1346,6 +1346,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
if segment.ident.name != kw::Empty {
if let Some(err) = self.report_method_error(
span,
Some(rcvr),
rcvr_t,
segment.ident,
SelfSource::MethodCall(rcvr),
Expand Down
1 change: 1 addition & 0 deletions compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
Original file line number Diff line number Diff line change
Expand Up @@ -834,6 +834,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
if item_name.name != kw::Empty {
if let Some(e) = self.report_method_error(
span,
None,
ty.normalized,
item_name,
SelfSource::QPath(qself),
Expand Down
213 changes: 207 additions & 6 deletions compiler/rustc_hir_typeck/src/method/suggest.rs
Original file line number Diff line number Diff line change
Expand Up @@ -7,6 +7,7 @@ use crate::errors::{self, CandidateTraitNote, NoAssociatedItem};
use crate::Expectation;
use crate::FnCtxt;
use core::ops::ControlFlow;
use hir::Expr;
use rustc_ast::ast::Mutability;
use rustc_attr::parse_confusables;
use rustc_data_structures::fx::{FxIndexMap, FxIndexSet};
Expand All @@ -19,7 +20,6 @@ use rustc_hir as hir;
use rustc_hir::def::DefKind;
use rustc_hir::def_id::DefId;
use rustc_hir::lang_items::LangItem;
use rustc_hir::PatKind::Binding;
use rustc_hir::PathSegment;
use rustc_hir::{ExprKind, Node, QPath};
use rustc_infer::infer::{self, RegionVariableOrigin};
Expand All @@ -46,7 +46,7 @@ use std::borrow::Cow;

use super::probe::{AutorefOrPtrAdjustment, IsSuggestion, Mode, ProbeScope};
use super::{CandidateSource, MethodError, NoMatchData};
use rustc_hir::intravisit::Visitor;
use rustc_hir::intravisit::{self, Visitor};

impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
fn is_fn_ty(&self, ty: Ty<'tcx>, span: Span) -> bool {
Expand Down Expand Up @@ -188,6 +188,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
pub fn report_method_error(
&self,
span: Span,
rcvr_opt: Option<&'tcx hir::Expr<'tcx>>,
rcvr_ty: Ty<'tcx>,
item_name: Ident,
source: SelfSource<'tcx>,
Expand All @@ -212,6 +213,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
MethodError::NoMatch(mut no_match_data) => {
return self.report_no_match_method_error(
span,
rcvr_opt,
rcvr_ty,
item_name,
source,
Expand Down Expand Up @@ -356,9 +358,197 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
err
}

pub fn suggest_use_shadowed_binding_with_method(
&self,
rcvr_opt: Option<&'tcx hir::Expr<'tcx>>,
method_name: Ident,
ty_str_reported: &str,
err: &mut Diag<'_>,
) {
#[derive(Debug)]
struct LetStmt {
ty_hir_id_opt: Option<hir::HirId>,
binding_id: hir::HirId,
span: Span,
init_hir_id: hir::HirId,
}

// Used for finding suggest binding.
// ```rust
// earlier binding for suggesting:
// let y = vec![1, 2];
// now binding:
// if let Some(y) = x {
// y.push(y);
// }
// ```
struct LetVisitor<'a, 'tcx> {
// Error binding which don't have `method_name`.
binding_name: Symbol,
binding_id: hir::HirId,
// Used for check if the suggest binding has `method_name`.
fcx: &'a FnCtxt<'a, 'tcx>,
call_expr: &'tcx Expr<'tcx>,
method_name: Ident,
// Suggest the binding which is shallowed.
sugg_let: Option<LetStmt>,
}

impl<'a, 'tcx> LetVisitor<'a, 'tcx> {
// Check scope of binding.
fn is_sub_scope(&self, sub_id: hir::ItemLocalId, super_id: hir::ItemLocalId) -> bool {
let scope_tree = self.fcx.tcx.region_scope_tree(self.fcx.body_id);
if let Some(sub_var_scope) = scope_tree.var_scope(sub_id)
&& let Some(super_var_scope) = scope_tree.var_scope(super_id)
&& scope_tree.is_subscope_of(sub_var_scope, super_var_scope)
{
return true;
}
false
}

// Check if an earlier shadowed binding make `the receiver` of a MethodCall has the method.
// If it does, record the earlier binding for subsequent notes.
fn check_and_add_sugg_binding(&mut self, binding: LetStmt) -> bool {
if !self.is_sub_scope(self.binding_id.local_id, binding.binding_id.local_id) {
return false;
}

// Get the earlier shadowed binding'ty and use it to check the method.
if let Some(ty_hir_id) = binding.ty_hir_id_opt
&& let Some(tyck_ty) = self.fcx.node_ty_opt(ty_hir_id)
{
if self
.fcx
.lookup_probe_for_diagnostic(
self.method_name,
tyck_ty,
self.call_expr,
ProbeScope::TraitsInScope,
None,
)
.is_ok()
{
self.sugg_let = Some(binding);
return true;
} else {
return false;
}
}

// If the shadowed binding has an an itializer expression,
// use the initializer expression'ty to try to find the method again.
// For example like: `let mut x = Vec::new();`,
// `Vec::new()` is the itializer expression.
if let Some(self_ty) = self.fcx.node_ty_opt(binding.init_hir_id)
&& self
.fcx
.lookup_probe_for_diagnostic(
self.method_name,
self_ty,
self.call_expr,
ProbeScope::TraitsInScope,
None,
)
.is_ok()
{
self.sugg_let = Some(binding);
return true;
}
return false;
}
}

impl<'v> Visitor<'v> for LetVisitor<'_, '_> {
type Result = ControlFlow<()>;
fn visit_stmt(&mut self, ex: &'v hir::Stmt<'v>) -> Self::Result {
if let hir::StmtKind::Let(&hir::LetStmt { pat, ty, init, .. }) = ex.kind
&& let hir::PatKind::Binding(_, binding_id, binding_name, ..) = pat.kind
&& let Some(init) = init
&& binding_name.name == self.binding_name
&& binding_id != self.binding_id
{
if self.check_and_add_sugg_binding(LetStmt {
ty_hir_id_opt: if let Some(ty) = ty { Some(ty.hir_id) } else { None },
binding_id: binding_id,
span: pat.span,
init_hir_id: init.hir_id,
}) {
return ControlFlow::Break(());
}
ControlFlow::Continue(())
} else {
hir::intravisit::walk_stmt(self, ex)
}
}

// Used for find the error binding.
// When the visitor reaches this point, all the shadowed bindings
// have been found, so the visitor ends.
fn visit_pat(&mut self, p: &'v hir::Pat<'v>) -> Self::Result {
match p.kind {
hir::PatKind::Binding(_, binding_id, binding_name, _) => {
if binding_name.name == self.binding_name && binding_id == self.binding_id {
return ControlFlow::Break(());
}
}
_ => {
intravisit::walk_pat(self, p);
}
}
ControlFlow::Continue(())
}
}

if let Some(rcvr) = rcvr_opt
&& let hir::ExprKind::Path(QPath::Resolved(_, path)) = rcvr.kind
&& let hir::def::Res::Local(recv_id) = path.res
&& let Some(segment) = path.segments.first()
{
let map = self.infcx.tcx.hir();
let body_id = self.tcx.hir().body_owned_by(self.body_id);
let body = map.body(body_id);

if let Node::Expr(call_expr) = self.tcx.parent_hir_node(rcvr.hir_id) {
let mut let_visitor = LetVisitor {
fcx: self,
call_expr,
binding_name: segment.ident.name,
binding_id: recv_id,
method_name,
sugg_let: None,
};
let_visitor.visit_body(body);
if let Some(sugg_let) = let_visitor.sugg_let
&& let Some(self_ty) = self.node_ty_opt(sugg_let.init_hir_id)
{
let _sm = self.infcx.tcx.sess.source_map();
let rcvr_name = segment.ident.name;
let mut span = MultiSpan::from_span(sugg_let.span);
span.push_span_label(sugg_let.span,
format!("`{rcvr_name}` of type `{self_ty}` that has method `{method_name}` defined earlier here"));
span.push_span_label(
self.tcx.hir().span(recv_id),
format!(
"earlier `{rcvr_name}` shadowed here with type `{ty_str_reported}`"
),
);
err.span_note(
span,
format!(
"there's an earlier shadowed binding `{rcvr_name}` of type `{self_ty}` \
that has method `{method_name}` available"
),
);
}
}
}
}

pub fn report_no_match_method_error(
&self,
mut span: Span,
rcvr_opt: Option<&'tcx hir::Expr<'tcx>>,
rcvr_ty: Ty<'tcx>,
item_name: Ident,
source: SelfSource<'tcx>,
Expand Down Expand Up @@ -451,7 +641,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
let mut err = if is_write && let SelfSource::MethodCall(rcvr_expr) = source {
self.suggest_missing_writer(rcvr_ty, rcvr_expr)
} else {
tcx.dcx().create_err(NoAssociatedItem {
let mut err = tcx.dcx().create_err(NoAssociatedItem {
span,
item_kind,
item_name,
Expand All @@ -461,9 +651,20 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
} else {
rcvr_ty.prefix_string(self.tcx)
},
ty_str: ty_str_reported,
ty_str: ty_str_reported.clone(),
trait_missing_method,
})
});

if is_method {
self.suggest_use_shadowed_binding_with_method(
rcvr_opt,
item_name,
&ty_str_reported,
&mut err,
);
}

err
};
if tcx.sess.source_map().is_multiline(sugg_span) {
err.span_label(sugg_span.with_hi(span.lo()), "");
Expand Down Expand Up @@ -2240,7 +2441,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
type Result = ControlFlow<Option<&'v hir::Expr<'v>>>;
fn visit_stmt(&mut self, ex: &'v hir::Stmt<'v>) -> Self::Result {
if let hir::StmtKind::Let(&hir::LetStmt { pat, init, .. }) = ex.kind
&& let Binding(_, _, ident, ..) = pat.kind
&& let hir::PatKind::Binding(_, _, ident, ..) = pat.kind
&& ident.name == self.ident_name
{
ControlFlow::Break(init)
Expand Down
8 changes: 8 additions & 0 deletions tests/ui/attributes/rustc_confusables_std_cases.stderr
Original file line number Diff line number Diff line change
Expand Up @@ -26,6 +26,14 @@ error[E0599]: no method named `push` found for struct `VecDeque` in the current
LL | x.push(1);
| ^^^^ method not found in `VecDeque<_>`
|
note: there's an earlier shadowed binding `x` of type `Vec<_>` that has method `push` available
--> $DIR/rustc_confusables_std_cases.rs:8:9
|
LL | let mut x = Vec::new();
| ^^^^^ `x` of type `Vec<_>` that has method `push` defined earlier here
...
LL | let mut x = VecDeque::new();
| ----- earlier `x` shadowed here with type `VecDeque`
help: you might have meant to use `push_back`
|
LL | x.push_back(1);
Expand Down
8 changes: 8 additions & 0 deletions tests/ui/derives/deriving-with-repr-packed-2.stderr
Original file line number Diff line number Diff line change
Expand Up @@ -10,6 +10,14 @@ LL | struct NonCopy;
LL | _ = x.clone();
| ^^^^^ method cannot be called on `Foo<NonCopy>` due to unsatisfied trait bounds
|
note: there's an earlier shadowed binding `x` of type `Foo<u32>` that has method `clone` available
--> $DIR/deriving-with-repr-packed-2.rs:13:9
|
LL | let x: Foo<u32> = Foo(1, 2, 3);
| ^ `x` of type `Foo<u32>` that has method `clone` defined earlier here
...
LL | let x: Foo<NonCopy> = Foo(NonCopy, NonCopy, NonCopy);
| - earlier `x` shadowed here with type `Foo<NonCopy>`
note: the following trait bounds were not satisfied:
`NonCopy: Clone`
`NonCopy: Copy`
Expand Down
Original file line number Diff line number Diff line change
@@ -0,0 +1,7 @@
fn main() {
let x = Some(3);
let y = vec![1, 2];
if let Some(y) = x {
y.push(y); //~ ERROR E0599
}
}
Original file line number Diff line number Diff line change
@@ -0,0 +1,17 @@
error[E0599]: no method named `push` found for type `{integer}` in the current scope
--> $DIR/account-for-shadowed-bindings-issue-123558.rs:5:11
|
LL | y.push(y);
| ^^^^ method not found in `{integer}`
|
note: there's an earlier shadowed binding `y` of type `Vec<{integer}>` that has method `push` available
--> $DIR/account-for-shadowed-bindings-issue-123558.rs:3:9
|
LL | let y = vec![1, 2];
| ^ `y` of type `Vec<{integer}>` that has method `push` defined earlier here
LL | if let Some(y) = x {
| - earlier `y` shadowed here with type `{integer}`

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0599`.

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