diff options
| -rw-r--r-- | clippy_lints/src/needless_pass_by_value.rs | 16 | ||||
| -rw-r--r-- | clippy_utils/src/lib.rs | 28 | ||||
| -rw-r--r-- | tests/ui/crashes/needless_pass_by_value-w-late-bound.stderr | 6 | ||||
| -rw-r--r-- | tests/ui/needless_pass_by_value.rs | 29 | ||||
| -rw-r--r-- | tests/ui/needless_pass_by_value.stderr | 168 |
5 files changed, 210 insertions, 37 deletions
diff --git a/clippy_lints/src/needless_pass_by_value.rs b/clippy_lints/src/needless_pass_by_value.rs index f5652e7b832..7aa1d63c660 100644 --- a/clippy_lints/src/needless_pass_by_value.rs +++ b/clippy_lints/src/needless_pass_by_value.rs @@ -1,10 +1,10 @@ use clippy_utils::diagnostics::span_lint_and_then; -use clippy_utils::is_self; use clippy_utils::ptr::get_spans; use clippy_utils::source::{SpanRangeExt, snippet}; use clippy_utils::ty::{ implements_trait, implements_trait_with_env_from_iter, is_copy, is_type_diagnostic_item, is_type_lang_item, }; +use clippy_utils::{is_self, peel_hir_ty_options}; use rustc_abi::ExternAbi; use rustc_errors::{Applicability, Diag}; use rustc_hir::intravisit::FnKind; @@ -279,18 +279,10 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessPassByValue { } } - let suggestion = if is_type_diagnostic_item(cx, ty, sym::Option) - && let snip = snippet(cx, input.span, "_") - && let Some((first, rest)) = snip.split_once('<') - { - format!("{first}<&{rest}") - } else { - format!("&{}", snippet(cx, input.span, "_")) - }; - diag.span_suggestion( - input.span, + diag.span_suggestion_verbose( + peel_hir_ty_options(cx, input).span.shrink_to_lo(), "consider taking a reference instead", - suggestion, + '&', Applicability::MaybeIncorrect, ); }; diff --git a/clippy_utils/src/lib.rs b/clippy_utils/src/lib.rs index 2d2a19c7b78..61b65382bb2 100644 --- a/clippy_utils/src/lib.rs +++ b/clippy_utils/src/lib.rs @@ -107,10 +107,10 @@ use rustc_hir::hir_id::{HirIdMap, HirIdSet}; use rustc_hir::intravisit::{FnKind, Visitor, walk_expr}; use rustc_hir::{ self as hir, Arm, BindingMode, Block, BlockCheckMode, Body, ByRef, Closure, ConstArgKind, ConstContext, - Destination, Expr, ExprField, ExprKind, FnDecl, FnRetTy, GenericArgs, HirId, Impl, ImplItem, ImplItemKind, - ImplItemRef, Item, ItemKind, LangItem, LetStmt, MatchSource, Mutability, Node, OwnerId, OwnerNode, Param, Pat, - PatExpr, PatExprKind, PatKind, Path, PathSegment, PrimTy, QPath, Stmt, StmtKind, TraitFn, TraitItem, TraitItemKind, - TraitItemRef, TraitRef, TyKind, UnOp, def, + Destination, Expr, ExprField, ExprKind, FnDecl, FnRetTy, GenericArg, GenericArgs, HirId, Impl, ImplItem, + ImplItemKind, ImplItemRef, Item, ItemKind, LangItem, LetStmt, MatchSource, Mutability, Node, OwnerId, OwnerNode, + Param, Pat, PatExpr, PatExprKind, PatKind, Path, PathSegment, PrimTy, QPath, Stmt, StmtKind, TraitFn, TraitItem, + TraitItemKind, TraitItemRef, TraitRef, TyKind, UnOp, def, }; use rustc_lexer::{TokenKind, tokenize}; use rustc_lint::{LateContext, Level, Lint, LintContext}; @@ -435,7 +435,7 @@ pub fn qpath_generic_tys<'tcx>(qpath: &QPath<'tcx>) -> impl Iterator<Item = &'tc .map_or(&[][..], |a| a.args) .iter() .filter_map(|a| match a { - hir::GenericArg::Type(ty) => Some(ty.as_unambig_ty()), + GenericArg::Type(ty) => Some(ty.as_unambig_ty()), _ => None, }) } @@ -3709,3 +3709,21 @@ pub fn is_mutable(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool { true } } + +/// Peel `Option<…>` from `hir_ty` as long as the HIR name is `Option` and it corresponds to the +/// `core::Option<_>` type. +pub fn peel_hir_ty_options<'tcx>(cx: &LateContext<'tcx>, mut hir_ty: &'tcx hir::Ty<'tcx>) -> &'tcx hir::Ty<'tcx> { + let Some(option_def_id) = cx.tcx.get_diagnostic_item(sym::Option) else { + return hir_ty; + }; + while let TyKind::Path(QPath::Resolved(None, path)) = hir_ty.kind + && let Some(segment) = path.segments.last() + && segment.ident.name == sym::Option + && let Res::Def(DefKind::Enum, def_id) = segment.res + && def_id == option_def_id + && let [GenericArg::Type(arg_ty)] = segment.args().args + { + hir_ty = arg_ty.as_unambig_ty(); + } + hir_ty +} diff --git a/tests/ui/crashes/needless_pass_by_value-w-late-bound.stderr b/tests/ui/crashes/needless_pass_by_value-w-late-bound.stderr index 28479570006..b4fb1222539 100644 --- a/tests/ui/crashes/needless_pass_by_value-w-late-bound.stderr +++ b/tests/ui/crashes/needless_pass_by_value-w-late-bound.stderr @@ -2,7 +2,7 @@ error: this argument is passed by value, but not consumed in the function body --> tests/ui/crashes/needless_pass_by_value-w-late-bound.rs:7:12 | LL | fn test(x: Foo<'_>) {} - | ^^^^^^^ help: consider taking a reference instead: `&Foo<'_>` + | ^^^^^^^ | help: or consider marking this type as `Copy` --> tests/ui/crashes/needless_pass_by_value-w-late-bound.rs:5:1 @@ -11,6 +11,10 @@ LL | struct Foo<'a>(&'a [(); 100]); | ^^^^^^^^^^^^^^ = note: `-D clippy::needless-pass-by-value` implied by `-D warnings` = help: to override `-D warnings` add `#[allow(clippy::needless_pass_by_value)]` +help: consider taking a reference instead + | +LL | fn test(x: &Foo<'_>) {} + | + error: aborting due to 1 previous error diff --git a/tests/ui/needless_pass_by_value.rs b/tests/ui/needless_pass_by_value.rs index adea373fd55..aef7fff2870 100644 --- a/tests/ui/needless_pass_by_value.rs +++ b/tests/ui/needless_pass_by_value.rs @@ -196,6 +196,35 @@ fn option_inner_ref(x: Option<String>) { assert!(x.is_some()); } +mod non_standard { + #[derive(Debug)] + pub struct Option<T>(T); +} + +fn non_standard_option(x: non_standard::Option<String>) { + //~^ needless_pass_by_value + dbg!(&x); +} + +fn option_by_name(x: Option<std::option::Option<core::option::Option<non_standard::Option<String>>>>) { + //~^ needless_pass_by_value + dbg!(&x); +} + +type OptStr = Option<String>; + +fn non_option(x: OptStr) { + //~^ needless_pass_by_value + dbg!(&x); +} + +type Opt<T> = Option<T>; + +fn non_option_either(x: Opt<String>) { + //~^ needless_pass_by_value + dbg!(&x); +} + fn main() { // This should not cause an ICE either // https://github.com/rust-lang/rust-clippy/issues/3144 diff --git a/tests/ui/needless_pass_by_value.stderr b/tests/ui/needless_pass_by_value.stderr index 987bfc4affc..e4381d1db53 100644 --- a/tests/ui/needless_pass_by_value.stderr +++ b/tests/ui/needless_pass_by_value.stderr @@ -17,43 +17,78 @@ error: this argument is passed by value, but not consumed in the function body --> tests/ui/needless_pass_by_value.rs:35:22 | LL | fn bar(x: String, y: Wrapper) { - | ^^^^^^^ help: consider taking a reference instead: `&Wrapper` + | ^^^^^^^ + | +help: consider taking a reference instead + | +LL | fn bar(x: String, y: &Wrapper) { + | + error: this argument is passed by value, but not consumed in the function body --> tests/ui/needless_pass_by_value.rs:44:71 | LL | fn test_borrow_trait<T: Borrow<str>, U: AsRef<str>, V>(t: T, u: U, v: V) { - | ^ help: consider taking a reference instead: `&V` + | ^ + | +help: consider taking a reference instead + | +LL | fn test_borrow_trait<T: Borrow<str>, U: AsRef<str>, V>(t: T, u: U, v: &V) { + | + error: this argument is passed by value, but not consumed in the function body --> tests/ui/needless_pass_by_value.rs:58:18 | LL | fn test_match(x: Option<Option<String>>, y: Option<Option<String>>) { - | ^^^^^^^^^^^^^^^^^^^^^^ help: consider taking a reference instead: `Option<&Option<String>>` + | ^^^^^^^^^^^^^^^^^^^^^^ + | +help: consider taking a reference instead + | +LL | fn test_match(x: Option<Option<&String>>, y: Option<Option<String>>) { + | + error: this argument is passed by value, but not consumed in the function body --> tests/ui/needless_pass_by_value.rs:73:24 | LL | fn test_destructure(x: Wrapper, y: Wrapper, z: Wrapper) { - | ^^^^^^^ help: consider taking a reference instead: `&Wrapper` + | ^^^^^^^ + | +help: consider taking a reference instead + | +LL | fn test_destructure(x: &Wrapper, y: Wrapper, z: Wrapper) { + | + error: this argument is passed by value, but not consumed in the function body --> tests/ui/needless_pass_by_value.rs:73:36 | LL | fn test_destructure(x: Wrapper, y: Wrapper, z: Wrapper) { - | ^^^^^^^ help: consider taking a reference instead: `&Wrapper` + | ^^^^^^^ + | +help: consider taking a reference instead + | +LL | fn test_destructure(x: Wrapper, y: &Wrapper, z: Wrapper) { + | + error: this argument is passed by value, but not consumed in the function body --> tests/ui/needless_pass_by_value.rs:92:49 | LL | fn test_blanket_ref<T: Foo, S: Serialize>(vals: T, serializable: S) {} - | ^ help: consider taking a reference instead: `&T` + | ^ + | +help: consider taking a reference instead + | +LL | fn test_blanket_ref<T: Foo, S: Serialize>(vals: &T, serializable: S) {} + | + error: this argument is passed by value, but not consumed in the function body --> tests/ui/needless_pass_by_value.rs:95:18 | LL | fn issue_2114(s: String, t: String, u: Vec<i32>, v: Vec<i32>) { - | ^^^^^^ help: consider taking a reference instead: `&String` + | ^^^^^^ + | +help: consider taking a reference instead + | +LL | fn issue_2114(s: &String, t: String, u: Vec<i32>, v: Vec<i32>) { + | + error: this argument is passed by value, but not consumed in the function body --> tests/ui/needless_pass_by_value.rs:95:29 @@ -76,7 +111,12 @@ error: this argument is passed by value, but not consumed in the function body --> tests/ui/needless_pass_by_value.rs:95:40 | LL | fn issue_2114(s: String, t: String, u: Vec<i32>, v: Vec<i32>) { - | ^^^^^^^^ help: consider taking a reference instead: `&Vec<i32>` + | ^^^^^^^^ + | +help: consider taking a reference instead + | +LL | fn issue_2114(s: String, t: String, u: &Vec<i32>, v: Vec<i32>) { + | + error: this argument is passed by value, but not consumed in the function body --> tests/ui/needless_pass_by_value.rs:95:53 @@ -105,85 +145,175 @@ error: this argument is passed by value, but not consumed in the function body --> tests/ui/needless_pass_by_value.rs:115:12 | LL | t: String, - | ^^^^^^ help: consider taking a reference instead: `&String` + | ^^^^^^ + | +help: consider taking a reference instead + | +LL | t: &String, + | + error: this argument is passed by value, but not consumed in the function body --> tests/ui/needless_pass_by_value.rs:125:23 | LL | fn baz(&self, uu: U, ss: Self) {} - | ^ help: consider taking a reference instead: `&U` + | ^ + | +help: consider taking a reference instead + | +LL | fn baz(&self, uu: &U, ss: Self) {} + | + error: this argument is passed by value, but not consumed in the function body --> tests/ui/needless_pass_by_value.rs:125:30 | LL | fn baz(&self, uu: U, ss: Self) {} - | ^^^^ help: consider taking a reference instead: `&Self` + | ^^^^ + | +help: consider taking a reference instead + | +LL | fn baz(&self, uu: U, ss: &Self) {} + | + error: this argument is passed by value, but not consumed in the function body --> tests/ui/needless_pass_by_value.rs:149:24 | LL | fn bar_copy(x: u32, y: CopyWrapper) { - | ^^^^^^^^^^^ help: consider taking a reference instead: `&CopyWrapper` + | ^^^^^^^^^^^ | help: or consider marking this type as `Copy` --> tests/ui/needless_pass_by_value.rs:147:1 | LL | struct CopyWrapper(u32); | ^^^^^^^^^^^^^^^^^^ +help: consider taking a reference instead + | +LL | fn bar_copy(x: u32, y: &CopyWrapper) { + | + error: this argument is passed by value, but not consumed in the function body --> tests/ui/needless_pass_by_value.rs:157:29 | LL | fn test_destructure_copy(x: CopyWrapper, y: CopyWrapper, z: CopyWrapper) { - | ^^^^^^^^^^^ help: consider taking a reference instead: `&CopyWrapper` + | ^^^^^^^^^^^ | help: or consider marking this type as `Copy` --> tests/ui/needless_pass_by_value.rs:147:1 | LL | struct CopyWrapper(u32); | ^^^^^^^^^^^^^^^^^^ +help: consider taking a reference instead + | +LL | fn test_destructure_copy(x: &CopyWrapper, y: CopyWrapper, z: CopyWrapper) { + | + error: this argument is passed by value, but not consumed in the function body --> tests/ui/needless_pass_by_value.rs:157:45 | LL | fn test_destructure_copy(x: CopyWrapper, y: CopyWrapper, z: CopyWrapper) { - | ^^^^^^^^^^^ help: consider taking a reference instead: `&CopyWrapper` + | ^^^^^^^^^^^ | help: or consider marking this type as `Copy` --> tests/ui/needless_pass_by_value.rs:147:1 | LL | struct CopyWrapper(u32); | ^^^^^^^^^^^^^^^^^^ +help: consider taking a reference instead + | +LL | fn test_destructure_copy(x: CopyWrapper, y: &CopyWrapper, z: CopyWrapper) { + | + error: this argument is passed by value, but not consumed in the function body --> tests/ui/needless_pass_by_value.rs:157:61 | LL | fn test_destructure_copy(x: CopyWrapper, y: CopyWrapper, z: CopyWrapper) { - | ^^^^^^^^^^^ help: consider taking a reference instead: `&CopyWrapper` + | ^^^^^^^^^^^ | help: or consider marking this type as `Copy` --> tests/ui/needless_pass_by_value.rs:147:1 | LL | struct CopyWrapper(u32); | ^^^^^^^^^^^^^^^^^^ +help: consider taking a reference instead + | +LL | fn test_destructure_copy(x: CopyWrapper, y: CopyWrapper, z: &CopyWrapper) { + | + error: this argument is passed by value, but not consumed in the function body --> tests/ui/needless_pass_by_value.rs:173:40 | LL | fn some_fun<'b, S: Bar<'b, ()>>(items: S) {} - | ^ help: consider taking a reference instead: `&S` + | ^ + | +help: consider taking a reference instead + | +LL | fn some_fun<'b, S: Bar<'b, ()>>(items: &S) {} + | + error: this argument is passed by value, but not consumed in the function body --> tests/ui/needless_pass_by_value.rs:179:20 | LL | fn more_fun(items: impl Club<'static, i32>) {} - | ^^^^^^^^^^^^^^^^^^^^^^^ help: consider taking a reference instead: `&impl Club<'static, i32>` + | ^^^^^^^^^^^^^^^^^^^^^^^ + | +help: consider taking a reference instead + | +LL | fn more_fun(items: &impl Club<'static, i32>) {} + | + error: this argument is passed by value, but not consumed in the function body --> tests/ui/needless_pass_by_value.rs:194:24 | LL | fn option_inner_ref(x: Option<String>) { - | ^^^^^^^^^^^^^^ help: consider taking a reference instead: `Option<&String>` + | ^^^^^^^^^^^^^^ + | +help: consider taking a reference instead + | +LL | fn option_inner_ref(x: Option<&String>) { + | + + +error: this argument is passed by value, but not consumed in the function body + --> tests/ui/needless_pass_by_value.rs:204:27 + | +LL | fn non_standard_option(x: non_standard::Option<String>) { + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: consider taking a reference instead + | +LL | fn non_standard_option(x: &non_standard::Option<String>) { + | + + +error: this argument is passed by value, but not consumed in the function body + --> tests/ui/needless_pass_by_value.rs:209:22 + | +LL | fn option_by_name(x: Option<std::option::Option<core::option::Option<non_standard::Option<String>>>>) { + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: consider taking a reference instead + | +LL | fn option_by_name(x: Option<std::option::Option<core::option::Option<&non_standard::Option<String>>>>) { + | + + +error: this argument is passed by value, but not consumed in the function body + --> tests/ui/needless_pass_by_value.rs:216:18 + | +LL | fn non_option(x: OptStr) { + | ^^^^^^ + | +help: consider taking a reference instead + | +LL | fn non_option(x: &OptStr) { + | + + +error: this argument is passed by value, but not consumed in the function body + --> tests/ui/needless_pass_by_value.rs:223:25 + | +LL | fn non_option_either(x: Opt<String>) { + | ^^^^^^^^^^^ + | +help: consider taking a reference instead + | +LL | fn non_option_either(x: &Opt<String>) { + | + -error: aborting due to 23 previous errors +error: aborting due to 27 previous errors |