diff options
author | Jason Newcomb <jsnewcomb@pm.me> | 2021-03-22 21:38:14 -0400 |
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committer | Jason Newcomb <jsnewcomb@pm.me> | 2021-03-24 16:22:28 -0400 |
commit | 99b8a671981eb9bf2c624027940bf9ae4cd23087 (patch) | |
tree | cf493f46a8d0fe7498077ac5863240a05f33bf73 | |
parent | 917b538c6857892a925a4e5d7c7cd448ad3488ab (diff) | |
download | rust-99b8a671981eb9bf2c624027940bf9ae4cd23087.tar.gz |
Fix false positive with `new_ret_no_self` when returning `Self` with different generic arguments
-rw-r--r-- | clippy_lints/src/methods/mod.rs | 14 | ||||
-rw-r--r-- | clippy_utils/src/ty.rs | 11 | ||||
-rw-r--r-- | tests/ui/new_ret_no_self.rs | 10 |
3 files changed, 31 insertions, 4 deletions
diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index d77f9c03cae..b6be77b03e5 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -61,7 +61,7 @@ mod zst_offset; use bind_instead_of_map::BindInsteadOfMap; use clippy_utils::diagnostics::{span_lint, span_lint_and_help}; -use clippy_utils::ty::{contains_ty, implements_trait, is_copy, is_type_diagnostic_item}; +use clippy_utils::ty::{contains_adt, contains_ty, implements_trait, is_copy, is_type_diagnostic_item}; use clippy_utils::{contains_return, get_trait_def_id, in_macro, iter_input_pats, method_calls, paths, return_ty}; use if_chain::if_chain; use rustc_hir as hir; @@ -1916,7 +1916,11 @@ impl<'tcx> LateLintPass<'tcx> for Methods { let ret_ty = return_ty(cx, impl_item.hir_id()); // walk the return type and check for Self (this does not check associated types) - if contains_ty(ret_ty, self_ty) { + if let Some(self_adt) = self_ty.ty_adt_def() { + if contains_adt(ret_ty, self_adt) { + return; + } + } else if contains_ty(ret_ty, self_ty) { return; } @@ -1926,7 +1930,11 @@ impl<'tcx> LateLintPass<'tcx> for Methods { for &(predicate, _span) in cx.tcx.explicit_item_bounds(def_id) { if let ty::PredicateKind::Projection(projection_predicate) = predicate.kind().skip_binder() { // walk the associated type and check for Self - if contains_ty(projection_predicate.ty, self_ty) { + if let Some(self_adt) = self_ty.ty_adt_def() { + if contains_adt(projection_predicate.ty, self_adt) { + return; + } + } else if contains_ty(projection_predicate.ty, self_ty) { return; } } diff --git a/clippy_utils/src/ty.rs b/clippy_utils/src/ty.rs index f4a1ae67da3..b9724efb04f 100644 --- a/clippy_utils/src/ty.rs +++ b/clippy_utils/src/ty.rs @@ -11,7 +11,7 @@ use rustc_hir::{TyKind, Unsafety}; use rustc_infer::infer::TyCtxtInferExt; use rustc_lint::LateContext; use rustc_middle::ty::subst::{GenericArg, GenericArgKind}; -use rustc_middle::ty::{self, IntTy, Ty, TypeFoldable, UintTy}; +use rustc_middle::ty::{self, AdtDef, IntTy, Ty, TypeFoldable, UintTy}; use rustc_span::sym; use rustc_span::symbol::Symbol; use rustc_span::DUMMY_SP; @@ -43,6 +43,15 @@ pub fn contains_ty(ty: Ty<'_>, other_ty: Ty<'_>) -> bool { }) } +/// Walks into `ty` and returns `true` if any inner type is any instance of the given abstract data +/// type.` +pub fn contains_adt(ty: Ty<'_>, adt: &AdtDef) -> bool { + ty.walk().any(|inner| match inner.unpack() { + GenericArgKind::Type(inner_ty) => inner_ty.ty_adt_def() == Some(adt), + GenericArgKind::Lifetime(_) | GenericArgKind::Const(_) => false, + }) +} + /// Returns true if ty has `iter` or `iter_mut` methods pub fn has_iter_method(cx: &LateContext<'_>, probably_ref_ty: Ty<'_>) -> Option<Symbol> { // FIXME: instead of this hard-coded list, we should check if `<adt>::iter` diff --git a/tests/ui/new_ret_no_self.rs b/tests/ui/new_ret_no_self.rs index e82873629a5..2f315ffe298 100644 --- a/tests/ui/new_ret_no_self.rs +++ b/tests/ui/new_ret_no_self.rs @@ -340,3 +340,13 @@ mod issue5435 { } } } + +// issue #1724 +struct RetOtherSelf<T>(T); +struct RetOtherSelfWrapper<T>(T); + +impl RetOtherSelf<T> { + fn new(t: T) -> RetOtherSelf<RetOtherSelfWrapper<T>> { + RetOtherSelf(RetOtherSelfWrapper(t)) + } +} |