From 1190c02bb89c8e127b449ec3cf7fcb51f0cfe0fd Mon Sep 17 00:00:00 2001 From: Centri3 <114838443+Centri3@users.noreply.github.com> Date: Sun, 14 May 2023 12:21:23 -0500 Subject: [PATCH 1/2] fix #10773 --- clippy_lints/src/useless_conversion.rs | 13 ++++++++++- tests/ui/useless_conversion.fixed | 6 +++++ tests/ui/useless_conversion.rs | 6 +++++ tests/ui/useless_conversion.stderr | 32 +++++++++++++------------- 4 files changed, 40 insertions(+), 17 deletions(-) diff --git a/clippy_lints/src/useless_conversion.rs b/clippy_lints/src/useless_conversion.rs index ddbe6b2c790..3d5c0514b58 100644 --- a/clippy_lints/src/useless_conversion.rs +++ b/clippy_lints/src/useless_conversion.rs @@ -5,7 +5,8 @@ use clippy_utils::ty::{is_copy, is_type_diagnostic_item, same_type_and_consts}; use clippy_utils::{get_parent_expr, is_trait_method, match_def_path, path_to_local, paths}; use if_chain::if_chain; use rustc_errors::Applicability; -use rustc_hir::{BindingAnnotation, Expr, ExprKind, HirId, MatchSource, Node, PatKind}; +use rustc_hir::def::{DefKind, Res}; +use rustc_hir::{BindingAnnotation, Expr, ExprKind, HirId, MatchSource, Node, PatKind, QPath, TyKind}; use rustc_lint::{LateContext, LateLintPass}; use rustc_middle::ty; use rustc_session::{declare_tool_lint, impl_lint_pass}; @@ -138,6 +139,7 @@ impl<'tcx> LateLintPass<'tcx> for UselessConversion { if_chain! { if let ExprKind::Path(ref qpath) = path.kind; if let Some(def_id) = cx.qpath_res(qpath, path.hir_id).opt_def_id(); + if !is_ty_alias(qpath); then { let a = cx.typeck_results().expr_ty(e); let b = cx.typeck_results().expr_ty(arg); @@ -195,3 +197,12 @@ impl<'tcx> LateLintPass<'tcx> for UselessConversion { } } } + +/// `cx.qpath_res` seems to return `AssocFn` so we do this instead +fn is_ty_alias(qpath: &QPath<'_>) -> bool { + match *qpath { + QPath::Resolved(_, path) => matches!(path.res, Res::Def(DefKind::TyAlias, ..)), + QPath::TypeRelative(ty, _) if let TyKind::Path(qpath) = ty.kind => is_ty_alias(&qpath), + _ => false, + } +} diff --git a/tests/ui/useless_conversion.fixed b/tests/ui/useless_conversion.fixed index 01eb6c5b080..c16caa38fe9 100644 --- a/tests/ui/useless_conversion.fixed +++ b/tests/ui/useless_conversion.fixed @@ -33,6 +33,11 @@ fn test_issue_3913() -> Result<(), std::io::Error> { Ok(()) } +fn dont_lint_on_type_alias() { + type A = i32; + _ = A::from(0i32); +} + fn dont_lint_into_iter_on_immutable_local_implementing_iterator_in_expr() { let text = "foo\r\nbar\n\nbaz\n"; let lines = text.lines(); @@ -106,6 +111,7 @@ fn main() { test_questionmark().unwrap(); test_issue_3913().unwrap(); + dont_lint_on_type_alias(); dont_lint_into_iter_on_immutable_local_implementing_iterator_in_expr(); lint_into_iter_on_mutable_local_implementing_iterator_in_expr(); lint_into_iter_on_expr_implementing_iterator(); diff --git a/tests/ui/useless_conversion.rs b/tests/ui/useless_conversion.rs index 34b43a6299b..c75a2bce4ca 100644 --- a/tests/ui/useless_conversion.rs +++ b/tests/ui/useless_conversion.rs @@ -33,6 +33,11 @@ fn test_issue_3913() -> Result<(), std::io::Error> { Ok(()) } +fn dont_lint_on_type_alias() { + type A = i32; + _ = A::from(0i32); +} + fn dont_lint_into_iter_on_immutable_local_implementing_iterator_in_expr() { let text = "foo\r\nbar\n\nbaz\n"; let lines = text.lines(); @@ -106,6 +111,7 @@ fn main() { test_questionmark().unwrap(); test_issue_3913().unwrap(); + dont_lint_on_type_alias(); dont_lint_into_iter_on_immutable_local_implementing_iterator_in_expr(); lint_into_iter_on_mutable_local_implementing_iterator_in_expr(); lint_into_iter_on_expr_implementing_iterator(); diff --git a/tests/ui/useless_conversion.stderr b/tests/ui/useless_conversion.stderr index be067c6843a..4dca3aac533 100644 --- a/tests/ui/useless_conversion.stderr +++ b/tests/ui/useless_conversion.stderr @@ -23,97 +23,97 @@ LL | let _: i32 = 0i32.into(); | ^^^^^^^^^^^ help: consider removing `.into()`: `0i32` error: useless conversion to the same type: `std::str::Lines<'_>` - --> $DIR/useless_conversion.rs:45:22 + --> $DIR/useless_conversion.rs:50:22 | LL | if Some("ok") == lines.into_iter().next() {} | ^^^^^^^^^^^^^^^^^ help: consider removing `.into_iter()`: `lines` error: useless conversion to the same type: `std::str::Lines<'_>` - --> $DIR/useless_conversion.rs:50:21 + --> $DIR/useless_conversion.rs:55:21 | LL | let mut lines = text.lines().into_iter(); | ^^^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `.into_iter()`: `text.lines()` error: useless conversion to the same type: `std::str::Lines<'_>` - --> $DIR/useless_conversion.rs:56:22 + --> $DIR/useless_conversion.rs:61:22 | LL | if Some("ok") == text.lines().into_iter().next() {} | ^^^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `.into_iter()`: `text.lines()` error: useless conversion to the same type: `std::ops::Range` - --> $DIR/useless_conversion.rs:62:13 + --> $DIR/useless_conversion.rs:67:13 | LL | let _ = NUMBERS.into_iter().next(); | ^^^^^^^^^^^^^^^^^^^ help: consider removing `.into_iter()`: `NUMBERS` error: useless conversion to the same type: `std::ops::Range` - --> $DIR/useless_conversion.rs:67:17 + --> $DIR/useless_conversion.rs:72:17 | LL | let mut n = NUMBERS.into_iter(); | ^^^^^^^^^^^^^^^^^^^ help: consider removing `.into_iter()`: `NUMBERS` error: useless conversion to the same type: `std::string::String` - --> $DIR/useless_conversion.rs:128:21 + --> $DIR/useless_conversion.rs:134:21 | LL | let _: String = "foo".to_string().into(); | ^^^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `.into()`: `"foo".to_string()` error: useless conversion to the same type: `std::string::String` - --> $DIR/useless_conversion.rs:129:21 + --> $DIR/useless_conversion.rs:135:21 | LL | let _: String = From::from("foo".to_string()); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `From::from()`: `"foo".to_string()` error: useless conversion to the same type: `std::string::String` - --> $DIR/useless_conversion.rs:130:13 + --> $DIR/useless_conversion.rs:136:13 | LL | let _ = String::from("foo".to_string()); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `String::from()`: `"foo".to_string()` error: useless conversion to the same type: `std::string::String` - --> $DIR/useless_conversion.rs:131:13 + --> $DIR/useless_conversion.rs:137:13 | LL | let _ = String::from(format!("A: {:04}", 123)); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `String::from()`: `format!("A: {:04}", 123)` error: useless conversion to the same type: `std::str::Lines<'_>` - --> $DIR/useless_conversion.rs:132:13 + --> $DIR/useless_conversion.rs:138:13 | LL | let _ = "".lines().into_iter(); | ^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `.into_iter()`: `"".lines()` error: useless conversion to the same type: `std::vec::IntoIter` - --> $DIR/useless_conversion.rs:133:13 + --> $DIR/useless_conversion.rs:139:13 | LL | let _ = vec![1, 2, 3].into_iter().into_iter(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `.into_iter()`: `vec![1, 2, 3].into_iter()` error: useless conversion to the same type: `std::string::String` - --> $DIR/useless_conversion.rs:134:21 + --> $DIR/useless_conversion.rs:140:21 | LL | let _: String = format!("Hello {}", "world").into(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `.into()`: `format!("Hello {}", "world")` error: useless conversion to the same type: `i32` - --> $DIR/useless_conversion.rs:139:13 + --> $DIR/useless_conversion.rs:145:13 | LL | let _ = i32::from(a + b) * 3; | ^^^^^^^^^^^^^^^^ help: consider removing `i32::from()`: `(a + b)` error: useless conversion to the same type: `Foo<'a'>` - --> $DIR/useless_conversion.rs:145:23 + --> $DIR/useless_conversion.rs:151:23 | LL | let _: Foo<'a'> = s2.into(); | ^^^^^^^^^ help: consider removing `.into()`: `s2` error: useless conversion to the same type: `Foo<'a'>` - --> $DIR/useless_conversion.rs:147:13 + --> $DIR/useless_conversion.rs:153:13 | LL | let _ = Foo::<'a'>::from(s3); | ^^^^^^^^^^^^^^^^^^^^ help: consider removing `Foo::<'a'>::from()`: `s3` error: useless conversion to the same type: `std::vec::IntoIter>` - --> $DIR/useless_conversion.rs:149:13 + --> $DIR/useless_conversion.rs:155:13 | LL | let _ = vec![s4, s4, s4].into_iter().into_iter(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `.into_iter()`: `vec![s4, s4, s4].into_iter()` From a36d9a7820be9040de8e56ec1852e2920377b935 Mon Sep 17 00:00:00 2001 From: Centri3 <114838443+Centri3@users.noreply.github.com> Date: Sun, 14 May 2023 12:39:08 -0500 Subject: [PATCH 2/2] move `is_ty_alias` to `clippy_utils` --- clippy_lints/src/useless_conversion.rs | 13 ++----------- clippy_utils/src/lib.rs | 10 ++++++++++ 2 files changed, 12 insertions(+), 11 deletions(-) diff --git a/clippy_lints/src/useless_conversion.rs b/clippy_lints/src/useless_conversion.rs index 3d5c0514b58..28c3fc859e3 100644 --- a/clippy_lints/src/useless_conversion.rs +++ b/clippy_lints/src/useless_conversion.rs @@ -1,12 +1,12 @@ use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_sugg}; +use clippy_utils::is_ty_alias; use clippy_utils::source::{snippet, snippet_with_context}; use clippy_utils::sugg::Sugg; use clippy_utils::ty::{is_copy, is_type_diagnostic_item, same_type_and_consts}; use clippy_utils::{get_parent_expr, is_trait_method, match_def_path, path_to_local, paths}; use if_chain::if_chain; use rustc_errors::Applicability; -use rustc_hir::def::{DefKind, Res}; -use rustc_hir::{BindingAnnotation, Expr, ExprKind, HirId, MatchSource, Node, PatKind, QPath, TyKind}; +use rustc_hir::{BindingAnnotation, Expr, ExprKind, HirId, MatchSource, Node, PatKind}; use rustc_lint::{LateContext, LateLintPass}; use rustc_middle::ty; use rustc_session::{declare_tool_lint, impl_lint_pass}; @@ -197,12 +197,3 @@ impl<'tcx> LateLintPass<'tcx> for UselessConversion { } } } - -/// `cx.qpath_res` seems to return `AssocFn` so we do this instead -fn is_ty_alias(qpath: &QPath<'_>) -> bool { - match *qpath { - QPath::Resolved(_, path) => matches!(path.res, Res::Def(DefKind::TyAlias, ..)), - QPath::TypeRelative(ty, _) if let TyKind::Path(qpath) = ty.kind => is_ty_alias(&qpath), - _ => false, - } -} diff --git a/clippy_utils/src/lib.rs b/clippy_utils/src/lib.rs index 964104fc31d..2e27c260f74 100644 --- a/clippy_utils/src/lib.rs +++ b/clippy_utils/src/lib.rs @@ -1,5 +1,6 @@ #![feature(array_chunks)] #![feature(box_patterns)] +#![feature(if_let_guard)] #![feature(let_chains)] #![feature(lint_reasons)] #![feature(never_type)] @@ -282,6 +283,15 @@ pub fn is_wild(pat: &Pat<'_>) -> bool { matches!(pat.kind, PatKind::Wild) } +/// Checks if the given `QPath` belongs to a type alias. +pub fn is_ty_alias(qpath: &QPath<'_>) -> bool { + match *qpath { + QPath::Resolved(_, path) => matches!(path.res, Res::Def(DefKind::TyAlias, ..)), + QPath::TypeRelative(ty, _) if let TyKind::Path(qpath) = ty.kind => { is_ty_alias(&qpath) }, + _ => false, + } +} + /// Checks if the method call given in `expr` belongs to the given trait. /// This is a deprecated function, consider using [`is_trait_method`]. pub fn match_trait_method(cx: &LateContext<'_>, expr: &Expr<'_>, path: &[&str]) -> bool {