user0/rust
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Auto merge of #11953 - Jarcho:issue_11952, r=Alexendoo

Browse source 
Fix binder handling in `unnecessary_to_owned`

fixes #11952

The use of `rebind` instead of `EarlyBinder::bind` isn't technically needed, but it is the semantically correct operation.

changelog: None
This commit is contained in:
bors 2023-12-13 18:57:50 +00:00
commit 29bdc8b2bc
4 changed files with 150 additions and 103 deletions
Download patch file Download diff file Expand all files Collapse all files

31
clippy_lints/src/methods/unnecessary_to_owned.rs
View file

@ -15,8 +15,7 @@ use rustc_lint::LateContext;
use rustc_middle::mir::Mutability;
use rustc_middle::ty::adjustment::{Adjust, Adjustment, OverloadedDeref};
use rustc_middle::ty::{
self, ClauseKind, EarlyBinder, GenericArg, GenericArgKind, GenericArgsRef, ParamTy, ProjectionPredicate,
TraitPredicate, Ty,
self, ClauseKind, GenericArg, GenericArgKind, GenericArgsRef, ParamTy, ProjectionPredicate, TraitPredicate, Ty,
};
use rustc_span::{sym, Symbol};
use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt as _;
@ -359,6 +358,7 @@ fn get_input_traits_and_projections<'tcx>(
(trait_predicates, projection_predicates)
}
#[expect(clippy::too_many_lines)]
fn can_change_type<'a>(cx: &LateContext<'a>, mut expr: &'a Expr<'a>, mut ty: Ty<'a>) -> bool {
for (_, node) in cx.tcx.hir().parent_iter(expr.hir_id) {
match node {
@ -387,22 +387,21 @@ fn can_change_type<'a>(cx: &LateContext<'a>, mut expr: &'a Expr<'a>, mut ty: Ty<
if let Some((callee_def_id, call_generic_args, recv, call_args)) =
get_callee_generic_args_and_args(cx, parent_expr)
{
// FIXME: the `instantiate_identity()` below seems incorrect, since we eventually
// call `tcx.try_instantiate_and_normalize_erasing_regions` further down
// (i.e., we are explicitly not in the identity context).
let fn_sig = cx.tcx.fn_sig(callee_def_id).instantiate_identity().skip_binder();
let bound_fn_sig = cx.tcx.fn_sig(callee_def_id);
let fn_sig = bound_fn_sig.skip_binder();
if let Some(arg_index) = recv.into_iter().chain(call_args).position(|arg| arg.hir_id == expr.hir_id)
&& let Some(param_ty) = fn_sig.inputs().get(arg_index)
&& let ty::Param(ParamTy { index: param_index , ..}) = param_ty.kind()
&& let param_ty = fn_sig.input(arg_index).skip_binder()
&& let ty::Param(ParamTy { index: param_index , ..}) = *param_ty.kind()
// https://github.com/rust-lang/rust-clippy/issues/9504 and https://github.com/rust-lang/rust-clippy/issues/10021
&& (*param_index as usize) < call_generic_args.len()
&& (param_index as usize) < call_generic_args.len()
{
if fn_sig
.skip_binder()
.inputs()
.iter()
.enumerate()
.filter(|(i, _)| *i != arg_index)
.any(|(_, ty)| ty.contains(*param_ty))
.any(|(_, ty)| ty.contains(param_ty))
{
return false;
}
@ -414,7 +413,7 @@ fn can_change_type<'a>(cx: &LateContext<'a>, mut expr: &'a Expr<'a>, mut ty: Ty<
.iter()
.filter(|predicate| {
if let ClauseKind::Trait(trait_predicate) = predicate.kind().skip_binder()
&& trait_predicate.trait_ref.self_ty() == *param_ty
&& trait_predicate.trait_ref.self_ty() == param_ty
{
true
} else {
@ -425,7 +424,7 @@ fn can_change_type<'a>(cx: &LateContext<'a>, mut expr: &'a Expr<'a>, mut ty: Ty<
let new_subst = cx
.tcx
.mk_args_from_iter(call_generic_args.iter().enumerate().map(|(i, t)| {
if i == (*param_index as usize) {
if i == param_index as usize {
GenericArg::from(ty)
} else {
t
@ -433,7 +432,7 @@ fn can_change_type<'a>(cx: &LateContext<'a>, mut expr: &'a Expr<'a>, mut ty: Ty<
}));
if trait_predicates.any(|predicate| {
let predicate = EarlyBinder::bind(predicate).instantiate(cx.tcx, new_subst);
let predicate = bound_fn_sig.rebind(predicate).instantiate(cx.tcx, new_subst);
let obligation = Obligation::new(cx.tcx, ObligationCause::dummy(), cx.param_env, predicate);
!cx.tcx
.infer_ctxt()
@ -443,12 +442,12 @@ fn can_change_type<'a>(cx: &LateContext<'a>, mut expr: &'a Expr<'a>, mut ty: Ty<
return false;
}
let output_ty = fn_sig.output();
if output_ty.contains(*param_ty) {
let output_ty = cx.tcx.instantiate_bound_regions_with_erased(fn_sig.output());
if output_ty.contains(param_ty) {
if let Ok(new_ty) = cx.tcx.try_instantiate_and_normalize_erasing_regions(
new_subst,
cx.param_env,
EarlyBinder::bind(output_ty),
bound_fn_sig.rebind(output_ty),
) {
expr = parent_expr;
ty = new_ty;