From ea15fb2177b0c33352363c130bc296a0dd1a794a Mon Sep 17 00:00:00 2001 From: Mateusz Gacek <96mateusz.gacek@gmail.com> Date: Wed, 17 Mar 2021 15:52:14 +0100 Subject: [PATCH] wrong_self_convention: `to_` respects `Copy` types More details here: https://rust-lang.github.io/api-guidelines/naming.html#ad-hoc-conversions-follow-as_-to_-into_-conventions-c-conv --- clippy_lints/src/methods/mod.rs | 39 ++++++---- .../src/methods/wrong_self_convention.rs | 74 +++++++++++-------- tests/ui/use_self.fixed | 1 + tests/ui/use_self.rs | 1 + tests/ui/use_self.stderr | 46 ++++++------ tests/ui/wrong_self_convention.rs | 32 ++++++++ tests/ui/wrong_self_convention.stderr | 36 ++++----- tests/ui/wrong_self_conventions_mut.stderr | 4 +- 8 files changed, 143 insertions(+), 90 deletions(-) diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index af8fe7abd962..722effc29b22 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -193,14 +193,18 @@ declare_clippy_lint! { /// **What it does:** Checks for methods with certain name prefixes and which /// doesn't match how self is taken. The actual rules are: /// - /// |Prefix |Postfix |`self` taken | - /// |-------|------------|----------------------| - /// |`as_` | none |`&self` or `&mut self`| - /// |`from_`| none | none | - /// |`into_`| none |`self` | - /// |`is_` | none |`&self` or none | - /// |`to_` | `_mut` |`&mut &self` | - /// |`to_` | not `_mut` |`&self` | + /// |Prefix |Postfix |`self` taken | `self` type | + /// |-------|------------|-----------------------|--------------| + /// |`as_` | none |`&self` or `&mut self` | any | + /// |`from_`| none | none | any | + /// |`into_`| none |`self` | any | + /// |`is_` | none |`&self` or none | any | + /// |`to_` | `_mut` |`&mut self` | any | + /// |`to_` | not `_mut` |`self` | `Copy` | + /// |`to_` | not `_mut` |`&self` | not `Copy` | + /// + /// Please find more info here: + /// https://rust-lang.github.io/api-guidelines/naming.html#ad-hoc-conversions-follow-as_-to_-into_-conventions-c-conv /// /// **Why is this bad?** Consistency breeds readability. If you follow the /// conventions, your users won't be surprised that they, e.g., need to supply a @@ -1837,10 +1841,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { let item = cx.tcx.hir().expect_item(parent); let self_ty = cx.tcx.type_of(item.def_id); - // if this impl block implements a trait, lint in trait definition instead - if let hir::ItemKind::Impl(hir::Impl { of_trait: Some(_), .. }) = item.kind { - return; - } + let implements_trait = matches!(item.kind, hir::ItemKind::Impl(hir::Impl { of_trait: Some(_), .. })); if_chain! { if let hir::ImplItemKind::Fn(ref sig, id) = impl_item.kind; @@ -1855,7 +1856,8 @@ impl<'tcx> LateLintPass<'tcx> for Methods { if let Some(first_arg_ty) = first_arg_ty; then { - if cx.access_levels.is_exported(impl_item.hir_id()) { + // if this impl block implements a trait, lint in trait definition instead + if !implements_trait && cx.access_levels.is_exported(impl_item.hir_id()) { // check missing trait implementations for method_config in &TRAIT_METHODS { if name == method_config.method_name && @@ -1891,11 +1893,17 @@ impl<'tcx> LateLintPass<'tcx> for Methods { item.vis.node.is_pub(), self_ty, first_arg_ty, - first_arg.pat.span + first_arg.pat.span, + false ); } } + // if this impl block implements a trait, lint in trait definition instead + if implements_trait { + return; + } + if let hir::ImplItemKind::Fn(_, _) = impl_item.kind { let ret_ty = return_ty(cx, impl_item.hir_id()); @@ -1947,7 +1955,8 @@ impl<'tcx> LateLintPass<'tcx> for Methods { false, self_ty, first_arg_ty, - first_arg_span + first_arg_span, + true ); } } diff --git a/clippy_lints/src/methods/wrong_self_convention.rs b/clippy_lints/src/methods/wrong_self_convention.rs index b728d7d8d08e..bece8f251daf 100644 --- a/clippy_lints/src/methods/wrong_self_convention.rs +++ b/clippy_lints/src/methods/wrong_self_convention.rs @@ -1,5 +1,6 @@ use crate::methods::SelfKind; use clippy_utils::diagnostics::span_lint_and_help; +use clippy_utils::ty::is_copy; use rustc_lint::LateContext; use rustc_middle::ty::TyS; use rustc_span::source_map::Span; @@ -9,7 +10,7 @@ use super::WRONG_PUB_SELF_CONVENTION; use super::WRONG_SELF_CONVENTION; #[rustfmt::skip] -const CONVENTIONS: [(&[Convention], &[SelfKind]); 8] = [ +const CONVENTIONS: [(&[Convention], &[SelfKind]); 9] = [ (&[Convention::Eq("new")], &[SelfKind::No]), (&[Convention::StartsWith("as_")], &[SelfKind::Ref, SelfKind::RefMut]), (&[Convention::StartsWith("from_")], &[SelfKind::No]), @@ -17,7 +18,11 @@ const CONVENTIONS: [(&[Convention], &[SelfKind]); 8] = [ (&[Convention::StartsWith("is_")], &[SelfKind::Ref, SelfKind::No]), (&[Convention::Eq("to_mut")], &[SelfKind::RefMut]), (&[Convention::StartsWith("to_"), Convention::EndsWith("_mut")], &[SelfKind::RefMut]), - (&[Convention::StartsWith("to_"), Convention::NotEndsWith("_mut")], &[SelfKind::Ref]), + + // Conversion using `to_` can use borrowed (non-Copy types) or owned (Copy types). + // Source: https://rust-lang.github.io/api-guidelines/naming.html#ad-hoc-conversions-follow-as_-to_-into_-conventions-c-conv + (&[Convention::StartsWith("to_"), Convention::NotEndsWith("_mut"), Convention::IsSelfTypeCopy(false), Convention::ImplementsTrait(false)], &[SelfKind::Ref]), + (&[Convention::StartsWith("to_"), Convention::NotEndsWith("_mut"), Convention::IsSelfTypeCopy(true), Convention::ImplementsTrait(false)], &[SelfKind::Value]), ]; enum Convention { @@ -25,16 +30,20 @@ enum Convention { StartsWith(&'static str), EndsWith(&'static str), NotEndsWith(&'static str), + IsSelfTypeCopy(bool), + ImplementsTrait(bool), } impl Convention { #[must_use] - fn check(&self, other: &str) -> bool { + fn check<'tcx>(&self, cx: &LateContext<'tcx>, self_ty: &'tcx TyS<'tcx>, other: &str, is_trait_def: bool) -> bool { match *self { Self::Eq(this) => this == other, Self::StartsWith(this) => other.starts_with(this) && this != other, Self::EndsWith(this) => other.ends_with(this) && this != other, - Self::NotEndsWith(this) => !Self::EndsWith(this).check(other), + Self::NotEndsWith(this) => !Self::EndsWith(this).check(cx, self_ty, other, is_trait_def), + Self::IsSelfTypeCopy(is_true) => is_true == is_copy(cx, self_ty), + Self::ImplementsTrait(is_true) => is_true == is_trait_def, } } } @@ -46,6 +55,10 @@ impl fmt::Display for Convention { Self::StartsWith(this) => this.fmt(f).and_then(|_| '*'.fmt(f)), Self::EndsWith(this) => '*'.fmt(f).and_then(|_| this.fmt(f)), Self::NotEndsWith(this) => '~'.fmt(f).and_then(|_| this.fmt(f)), + Self::IsSelfTypeCopy(is_true) => format!("self type is {} Copy", if is_true { "" } else { "not" }).fmt(f), + Self::ImplementsTrait(is_true) => { + format!("Method {} implement a trait", if is_true { "" } else { "do not" }).fmt(f) + }, } } } @@ -57,45 +70,42 @@ pub(super) fn check<'tcx>( self_ty: &'tcx TyS<'tcx>, first_arg_ty: &'tcx TyS<'tcx>, first_arg_span: Span, + is_trait_item: bool, ) { let lint = if is_pub { WRONG_PUB_SELF_CONVENTION } else { WRONG_SELF_CONVENTION }; - if let Some((conventions, self_kinds)) = &CONVENTIONS - .iter() - .find(|(convs, _)| convs.iter().all(|conv| conv.check(item_name))) - { + if let Some((conventions, self_kinds)) = &CONVENTIONS.iter().find(|(convs, _)| { + convs + .iter() + .all(|conv| conv.check(cx, self_ty, item_name, is_trait_item)) + }) { if !self_kinds.iter().any(|k| k.matches(cx, self_ty, first_arg_ty)) { let suggestion = { if conventions.len() > 1 { - let special_case = { - // Don't mention `NotEndsWith` when there is also `StartsWith` convention present - if conventions.len() == 2 { - match conventions { - [Convention::StartsWith(starts_with), Convention::NotEndsWith(_)] - | [Convention::NotEndsWith(_), Convention::StartsWith(starts_with)] => { - Some(format!("methods called `{}`", Convention::StartsWith(starts_with))) - }, - _ => None, - } - } else { - None - } - }; - - if let Some(suggestion) = special_case { - suggestion - } else { - let s = conventions + // Don't mention `NotEndsWith` when there is also `StartsWith` convention present + let cut_ends_with_conv = conventions.iter().any(|conv| matches!(conv, Convention::StartsWith(_))) + && conventions .iter() - .map(|c| format!("`{}`", &c.to_string())) - .collect::>() - .join(" and "); + .any(|conv| matches!(conv, Convention::NotEndsWith(_))); + + let s = conventions + .iter() + .filter_map(|conv| { + if (cut_ends_with_conv && matches!(conv, Convention::NotEndsWith(_))) + || matches!(conv, Convention::ImplementsTrait(_)) + { + None + } else { + Some(format!("`{}`", &conv.to_string())) + } + }) + .collect::>() + .join(" and "); - format!("methods called like this: ({})", &s) - } + format!("methods with the following characteristics: ({})", &s) } else { format!("methods called `{}`", &conventions[0]) } diff --git a/tests/ui/use_self.fixed b/tests/ui/use_self.fixed index a630936e3b1d..1986b54e66c6 100644 --- a/tests/ui/use_self.fixed +++ b/tests/ui/use_self.fixed @@ -79,6 +79,7 @@ mod issue2894 { } // This should not be linted + #[allow(clippy::wrong_self_convention)] impl IntoBytes for u8 { fn to_bytes(&self) -> Vec { vec![*self] diff --git a/tests/ui/use_self.rs b/tests/ui/use_self.rs index f3e081dd2032..acc18280f1a5 100644 --- a/tests/ui/use_self.rs +++ b/tests/ui/use_self.rs @@ -79,6 +79,7 @@ mod issue2894 { } // This should not be linted + #[allow(clippy::wrong_self_convention)] impl IntoBytes for u8 { fn to_bytes(&self) -> Vec { vec![*self] diff --git a/tests/ui/use_self.stderr b/tests/ui/use_self.stderr index e1410d2e652c..a2c959634878 100644 --- a/tests/ui/use_self.stderr +++ b/tests/ui/use_self.stderr @@ -37,139 +37,139 @@ LL | Foo::new() | ^^^ help: use the applicable keyword: `Self` error: unnecessary structure name repetition - --> $DIR/use_self.rs:93:24 + --> $DIR/use_self.rs:94:24 | LL | fn bad(foos: &[Foo]) -> impl Iterator { | ^^^ help: use the applicable keyword: `Self` error: unnecessary structure name repetition - --> $DIR/use_self.rs:93:55 + --> $DIR/use_self.rs:94:55 | LL | fn bad(foos: &[Foo]) -> impl Iterator { | ^^^ help: use the applicable keyword: `Self` error: unnecessary structure name repetition - --> $DIR/use_self.rs:108:13 + --> $DIR/use_self.rs:109:13 | LL | TS(0) | ^^ help: use the applicable keyword: `Self` error: unnecessary structure name repetition - --> $DIR/use_self.rs:143:29 + --> $DIR/use_self.rs:144:29 | LL | fn bar() -> Bar { | ^^^ help: use the applicable keyword: `Self` error: unnecessary structure name repetition - --> $DIR/use_self.rs:144:21 + --> $DIR/use_self.rs:145:21 | LL | Bar { foo: Foo {} } | ^^^ help: use the applicable keyword: `Self` error: unnecessary structure name repetition - --> $DIR/use_self.rs:155:21 + --> $DIR/use_self.rs:156:21 | LL | fn baz() -> Foo { | ^^^ help: use the applicable keyword: `Self` error: unnecessary structure name repetition - --> $DIR/use_self.rs:156:13 + --> $DIR/use_self.rs:157:13 | LL | Foo {} | ^^^ help: use the applicable keyword: `Self` error: unnecessary structure name repetition - --> $DIR/use_self.rs:173:21 + --> $DIR/use_self.rs:174:21 | LL | let _ = Enum::B(42); | ^^^^ help: use the applicable keyword: `Self` error: unnecessary structure name repetition - --> $DIR/use_self.rs:174:21 + --> $DIR/use_self.rs:175:21 | LL | let _ = Enum::C { field: true }; | ^^^^ help: use the applicable keyword: `Self` error: unnecessary structure name repetition - --> $DIR/use_self.rs:175:21 + --> $DIR/use_self.rs:176:21 | LL | let _ = Enum::A; | ^^^^ help: use the applicable keyword: `Self` error: unnecessary structure name repetition - --> $DIR/use_self.rs:217:13 + --> $DIR/use_self.rs:218:13 | LL | nested::A::fun_1(); | ^^^^^^^^^ help: use the applicable keyword: `Self` error: unnecessary structure name repetition - --> $DIR/use_self.rs:218:13 + --> $DIR/use_self.rs:219:13 | LL | nested::A::A; | ^^^^^^^^^ help: use the applicable keyword: `Self` error: unnecessary structure name repetition - --> $DIR/use_self.rs:220:13 + --> $DIR/use_self.rs:221:13 | LL | nested::A {}; | ^^^^^^^^^ help: use the applicable keyword: `Self` error: unnecessary structure name repetition - --> $DIR/use_self.rs:239:13 + --> $DIR/use_self.rs:240:13 | LL | TestStruct::from_something() | ^^^^^^^^^^ help: use the applicable keyword: `Self` error: unnecessary structure name repetition - --> $DIR/use_self.rs:253:25 + --> $DIR/use_self.rs:254:25 | LL | async fn g() -> S { | ^ help: use the applicable keyword: `Self` error: unnecessary structure name repetition - --> $DIR/use_self.rs:254:13 + --> $DIR/use_self.rs:255:13 | LL | S {} | ^ help: use the applicable keyword: `Self` error: unnecessary structure name repetition - --> $DIR/use_self.rs:258:16 + --> $DIR/use_self.rs:259:16 | LL | &p[S::A..S::B] | ^ help: use the applicable keyword: `Self` error: unnecessary structure name repetition - --> $DIR/use_self.rs:258:22 + --> $DIR/use_self.rs:259:22 | LL | &p[S::A..S::B] | ^ help: use the applicable keyword: `Self` error: unnecessary structure name repetition - --> $DIR/use_self.rs:281:29 + --> $DIR/use_self.rs:282:29 | LL | fn foo(value: T) -> Foo { | ^^^^^^ help: use the applicable keyword: `Self` error: unnecessary structure name repetition - --> $DIR/use_self.rs:282:13 + --> $DIR/use_self.rs:283:13 | LL | Foo { value } | ^^^ help: use the applicable keyword: `Self` error: unnecessary structure name repetition - --> $DIR/use_self.rs:319:21 + --> $DIR/use_self.rs:320:21 | LL | type From = T::From; | ^^^^^^^ help: use the applicable keyword: `Self` error: unnecessary structure name repetition - --> $DIR/use_self.rs:320:19 + --> $DIR/use_self.rs:321:19 | LL | type To = T::To; | ^^^^^ help: use the applicable keyword: `Self` error: unnecessary structure name repetition - --> $DIR/use_self.rs:453:13 + --> $DIR/use_self.rs:454:13 | LL | A::new::(submod::B {}) | ^ help: use the applicable keyword: `Self` diff --git a/tests/ui/wrong_self_convention.rs b/tests/ui/wrong_self_convention.rs index 6cfc0fcb4cae..ba9e19a17220 100644 --- a/tests/ui/wrong_self_convention.rs +++ b/tests/ui/wrong_self_convention.rs @@ -163,3 +163,35 @@ mod issue6307 { fn to_mut(&mut self); } } + +mod issue6727 { + trait ToU64 { + fn to_u64(self) -> u64; + fn to_u64_v2(&self) -> u64; + } + + #[derive(Clone, Copy)] + struct FooCopy; + + impl ToU64 for FooCopy { + fn to_u64(self) -> u64 { + 1 + } + // trigger lint + fn to_u64_v2(&self) -> u64 { + 1 + } + } + + struct FooNoCopy; + + impl ToU64 for FooNoCopy { + // trigger lint + fn to_u64(self) -> u64 { + 2 + } + fn to_u64_v2(&self) -> u64 { + 2 + } + } +} diff --git a/tests/ui/wrong_self_convention.stderr b/tests/ui/wrong_self_convention.stderr index f43fea0d5137..6daa334ed487 100644 --- a/tests/ui/wrong_self_convention.stderr +++ b/tests/ui/wrong_self_convention.stderr @@ -39,7 +39,7 @@ LL | fn is_i32(self) {} | = help: consider choosing a less ambiguous name -error: methods called `to_*` usually take self by reference +error: methods with the following characteristics: (`to_*` and `self type is not Copy`) usually take self by reference --> $DIR/wrong_self_convention.rs:42:15 | LL | fn to_i32(self) {} @@ -79,7 +79,7 @@ LL | pub fn is_i64(self) {} | = help: consider choosing a less ambiguous name -error: methods called `to_*` usually take self by reference +error: methods with the following characteristics: (`to_*` and `self type is not Copy`) usually take self by reference --> $DIR/wrong_self_convention.rs:49:19 | LL | pub fn to_i64(self) {} @@ -119,14 +119,6 @@ LL | fn is_i32(self) {} | = help: consider choosing a less ambiguous name -error: methods called `to_*` usually take self by reference - --> $DIR/wrong_self_convention.rs:102:19 - | -LL | fn to_i32(self) {} - | ^^^^ - | - = help: consider choosing a less ambiguous name - error: methods called `from_*` usually take no self --> $DIR/wrong_self_convention.rs:104:21 | @@ -159,14 +151,6 @@ LL | fn is_i32(self); | = help: consider choosing a less ambiguous name -error: methods called `to_*` usually take self by reference - --> $DIR/wrong_self_convention.rs:126:19 - | -LL | fn to_i32(self); - | ^^^^ - | - = help: consider choosing a less ambiguous name - error: methods called `from_*` usually take no self --> $DIR/wrong_self_convention.rs:128:21 | @@ -191,5 +175,21 @@ LL | fn from_i32(self); | = help: consider choosing a less ambiguous name +error: methods with the following characteristics: (`to_*` and `self type is Copy`) usually take self by value + --> $DIR/wrong_self_convention.rs:181:22 + | +LL | fn to_u64_v2(&self) -> u64 { + | ^^^^^ + | + = help: consider choosing a less ambiguous name + +error: methods with the following characteristics: (`to_*` and `self type is not Copy`) usually take self by reference + --> $DIR/wrong_self_convention.rs:190:19 + | +LL | fn to_u64(self) -> u64 { + | ^^^^ + | + = help: consider choosing a less ambiguous name + error: aborting due to 24 previous errors diff --git a/tests/ui/wrong_self_conventions_mut.stderr b/tests/ui/wrong_self_conventions_mut.stderr index 7662b38e67d0..8095188758c3 100644 --- a/tests/ui/wrong_self_conventions_mut.stderr +++ b/tests/ui/wrong_self_conventions_mut.stderr @@ -1,4 +1,4 @@ -error: methods called `to_*` usually take self by reference +error: methods with the following characteristics: (`to_*` and `self type is not Copy`) usually take self by reference --> $DIR/wrong_self_conventions_mut.rs:15:24 | LL | pub fn to_many(&mut self) -> Option<&mut [T]> { @@ -7,7 +7,7 @@ LL | pub fn to_many(&mut self) -> Option<&mut [T]> { = note: `-D clippy::wrong-self-convention` implied by `-D warnings` = help: consider choosing a less ambiguous name -error: methods called like this: (`to_*` and `*_mut`) usually take self by mutable reference +error: methods with the following characteristics: (`to_*` and `*_mut`) usually take self by mutable reference --> $DIR/wrong_self_conventions_mut.rs:23:28 | LL | pub fn to_many_mut(&self) -> Option<&[T]> {