diff options
| -rw-r--r-- | compiler/rustc_lint/src/unused.rs | 316 | ||||
| -rw-r--r-- | src/test/ui/lint/unused/must-use-ops.rs | 20 | ||||
| -rw-r--r-- | src/test/ui/lint/unused/must-use-ops.stderr | 42 | ||||
| -rw-r--r-- | src/test/ui/lint/unused/must_use-array.rs | 7 | ||||
| -rw-r--r-- | src/test/ui/lint/unused/must_use-array.stderr | 20 |
5 files changed, 259 insertions, 146 deletions
diff --git a/compiler/rustc_lint/src/unused.rs b/compiler/rustc_lint/src/unused.rs index cdf279313a6..5c4c46f84d7 100644 --- a/compiler/rustc_lint/src/unused.rs +++ b/compiler/rustc_lint/src/unused.rs @@ -13,6 +13,7 @@ use rustc_middle::ty::{self, DefIdTree, Ty}; use rustc_span::symbol::Symbol; use rustc_span::symbol::{kw, sym}; use rustc_span::{BytePos, Span}; +use std::iter; declare_lint! { /// The `unused_must_use` lint detects unused result of a type flagged as @@ -113,30 +114,19 @@ impl<'tcx> LateLintPass<'tcx> for UnusedResults { } let ty = cx.typeck_results().expr_ty(&expr); - let type_permits_lack_of_use = check_must_use_ty(cx, ty, &expr, expr.span, "", "", 1); - let mut fn_warned = false; - let mut op_warned = false; - let maybe_def_id = match expr.kind { - hir::ExprKind::Call(ref callee, _) => { - match callee.kind { - hir::ExprKind::Path(ref qpath) => { - match cx.qpath_res(qpath, callee.hir_id) { - Res::Def(DefKind::Fn | DefKind::AssocFn, def_id) => Some(def_id), - // `Res::Local` if it was a closure, for which we - // do not currently support must-use linting - _ => None, - } - } - _ => None, - } + let must_use_result = is_ty_must_use(cx, ty, &expr, expr.span); + let type_lint_emitted_or_suppressed = match must_use_result { + Some(path) => { + emit_must_use_untranslated(cx, &path, "", "", 1); + true } - hir::ExprKind::MethodCall(..) => cx.typeck_results().type_dependent_def_id(expr.hir_id), - _ => None, + None => false, }; - if let Some(def_id) = maybe_def_id { - fn_warned = check_must_use_def(cx, def_id, expr.span, "return value of ", ""); - } else if type_permits_lack_of_use { + + let fn_warned = check_fn_must_use(cx, expr); + + if !fn_warned && type_lint_emitted_or_suppressed { // We don't warn about unused unit or uninhabited types. // (See https://github.com/rust-lang/rust/issues/43806 for details.) return; @@ -170,6 +160,8 @@ impl<'tcx> LateLintPass<'tcx> for UnusedResults { _ => None, }; + let mut op_warned = false; + if let Some(must_use_op) = must_use_op { cx.struct_span_lint(UNUSED_MUST_USE, expr.span, fluent::lint_unused_op, |lint| { lint.set_arg("op", must_use_op) @@ -184,22 +176,64 @@ impl<'tcx> LateLintPass<'tcx> for UnusedResults { op_warned = true; } - if !(type_permits_lack_of_use || fn_warned || op_warned) { + if !(type_lint_emitted_or_suppressed || fn_warned || op_warned) { cx.struct_span_lint(UNUSED_RESULTS, s.span, fluent::lint_unused_result, |lint| { lint.set_arg("ty", ty) }); } - // Returns whether an error has been emitted (and thus another does not need to be later). - fn check_must_use_ty<'tcx>( + fn check_fn_must_use(cx: &LateContext<'_>, expr: &hir::Expr<'_>) -> bool { + let maybe_def_id = match expr.kind { + hir::ExprKind::Call(ref callee, _) => { + match callee.kind { + hir::ExprKind::Path(ref qpath) => { + match cx.qpath_res(qpath, callee.hir_id) { + Res::Def(DefKind::Fn | DefKind::AssocFn, def_id) => Some(def_id), + // `Res::Local` if it was a closure, for which we + // do not currently support must-use linting + _ => None, + } + } + _ => None, + } + } + hir::ExprKind::MethodCall(..) => { + cx.typeck_results().type_dependent_def_id(expr.hir_id) + } + _ => None, + }; + if let Some(def_id) = maybe_def_id { + check_must_use_def(cx, def_id, expr.span, "return value of ", "") + } else { + false + } + } + + /// A path through a type to a must_use source. Contains useful info for the lint. + #[derive(Debug)] + enum MustUsePath { + /// Suppress must_use checking. + Suppressed, + /// The root of the normal must_use lint with an optional message. + Def(Span, DefId, Option<Symbol>), + Boxed(Box<Self>), + Opaque(Box<Self>), + TraitObject(Box<Self>), + TupleElement(Vec<(usize, Self)>), + Array(Box<Self>, u64), + /// The root of the unused_closures lint. + Closure(Span), + /// The root of the unused_generators lint. + Generator(Span), + } + + #[instrument(skip(cx, expr), level = "debug", ret)] + fn is_ty_must_use<'tcx>( cx: &LateContext<'tcx>, ty: Ty<'tcx>, expr: &hir::Expr<'_>, span: Span, - descr_pre: &str, - descr_post: &str, - plural_len: usize, - ) -> bool { + ) -> Option<MustUsePath> { if ty.is_unit() || cx.tcx.is_ty_uninhabited_from( cx.tcx.parent_module(expr.hir_id).to_def_id(), @@ -207,87 +241,164 @@ impl<'tcx> LateLintPass<'tcx> for UnusedResults { cx.param_env, ) { - return true; + return Some(MustUsePath::Suppressed); } - let plural_suffix = pluralize!(plural_len); - match *ty.kind() { ty::Adt(..) if ty.is_box() => { let boxed_ty = ty.boxed_ty(); - let descr_pre = &format!("{}boxed ", descr_pre); - check_must_use_ty(cx, boxed_ty, expr, span, descr_pre, descr_post, plural_len) + is_ty_must_use(cx, boxed_ty, expr, span) + .map(|inner| MustUsePath::Boxed(Box::new(inner))) } - ty::Adt(def, _) => check_must_use_def(cx, def.did(), span, descr_pre, descr_post), + ty::Adt(def, _) => is_def_must_use(cx, def.did(), span), ty::Opaque(def, _) => { - let mut has_emitted = false; - for obligation in elaborate_predicates_with_span( + elaborate_predicates_with_span( cx.tcx, cx.tcx.explicit_item_bounds(def).iter().cloned(), - ) { + ) + .filter_map(|obligation| { // We only look at the `DefId`, so it is safe to skip the binder here. if let ty::PredicateKind::Trait(ref poly_trait_predicate) = obligation.predicate.kind().skip_binder() { let def_id = poly_trait_predicate.trait_ref.def_id; - let descr_pre = - &format!("{}implementer{} of ", descr_pre, plural_suffix,); - if check_must_use_def(cx, def_id, span, descr_pre, descr_post) { - has_emitted = true; - break; - } + + is_def_must_use(cx, def_id, span) + } else { + None } - } - has_emitted + }) + .map(|inner| MustUsePath::Opaque(Box::new(inner))) + .next() } - ty::Dynamic(binder, _, _) => { - let mut has_emitted = false; - for predicate in binder.iter() { + ty::Dynamic(binders, _, _) => binders + .iter() + .filter_map(|predicate| { if let ty::ExistentialPredicate::Trait(ref trait_ref) = predicate.skip_binder() { let def_id = trait_ref.def_id; - let descr_post = - &format!(" trait object{}{}", plural_suffix, descr_post,); - if check_must_use_def(cx, def_id, span, descr_pre, descr_post) { - has_emitted = true; - break; - } + is_def_must_use(cx, def_id, span) + } else { + None } - } - has_emitted - } - ty::Tuple(ref tys) => { - let mut has_emitted = false; - let comps = if let hir::ExprKind::Tup(comps) = expr.kind { - debug_assert_eq!(comps.len(), tys.len()); - comps + .map(|inner| MustUsePath::TraitObject(Box::new(inner))) + }) + .next(), + ty::Tuple(tys) => { + let elem_exprs = if let hir::ExprKind::Tup(elem_exprs) = expr.kind { + debug_assert_eq!(elem_exprs.len(), tys.len()); + elem_exprs } else { &[] }; - for (i, ty) in tys.iter().enumerate() { - let descr_post = &format!(" in tuple element {}", i); - let e = comps.get(i).unwrap_or(expr); - let span = e.span; - if check_must_use_ty(cx, ty, e, span, descr_pre, descr_post, plural_len) { - has_emitted = true; - } + + // Default to `expr`. + let elem_exprs = elem_exprs.iter().chain(iter::repeat(expr)); + + let nested_must_use = tys + .iter() + .zip(elem_exprs) + .enumerate() + .filter_map(|(i, (ty, expr))| { + is_ty_must_use(cx, ty, expr, expr.span).map(|path| (i, path)) + }) + .collect::<Vec<_>>(); + + if !nested_must_use.is_empty() { + Some(MustUsePath::TupleElement(nested_must_use)) + } else { + None } - has_emitted } ty::Array(ty, len) => match len.try_eval_usize(cx.tcx, cx.param_env) { // If the array is empty we don't lint, to avoid false positives - Some(0) | None => false, + Some(0) | None => None, // If the array is definitely non-empty, we can do `#[must_use]` checking. - Some(n) => { - let descr_pre = &format!("{}array{} of ", descr_pre, plural_suffix,); - check_must_use_ty(cx, ty, expr, span, descr_pre, descr_post, n as usize + 1) - } + Some(len) => is_ty_must_use(cx, ty, expr, span) + .map(|inner| MustUsePath::Array(Box::new(inner), len)), }, - ty::Closure(..) => { + ty::Closure(..) => Some(MustUsePath::Closure(span)), + ty::Generator(..) => Some(MustUsePath::Generator(span)), + _ => None, + } + } + + fn is_def_must_use(cx: &LateContext<'_>, def_id: DefId, span: Span) -> Option<MustUsePath> { + if let Some(attr) = cx.tcx.get_attr(def_id, sym::must_use) { + // check for #[must_use = "..."] + let reason = attr.value_str(); + Some(MustUsePath::Def(span, def_id, reason)) + } else { + None + } + } + + // Returns whether further errors should be suppressed because either a lint has been emitted or the type should be ignored. + fn check_must_use_def( + cx: &LateContext<'_>, + def_id: DefId, + span: Span, + descr_pre_path: &str, + descr_post_path: &str, + ) -> bool { + is_def_must_use(cx, def_id, span) + .map(|must_use_path| { + emit_must_use_untranslated( + cx, + &must_use_path, + descr_pre_path, + descr_post_path, + 1, + ) + }) + .is_some() + } + + #[instrument(skip(cx), level = "debug")] + fn emit_must_use_untranslated( + cx: &LateContext<'_>, + path: &MustUsePath, + descr_pre: &str, + descr_post: &str, + plural_len: usize, + ) { + let plural_suffix = pluralize!(plural_len); + + match path { + MustUsePath::Suppressed => {} + MustUsePath::Boxed(path) => { + let descr_pre = &format!("{}boxed ", descr_pre); + emit_must_use_untranslated(cx, path, descr_pre, descr_post, plural_len); + } + MustUsePath::Opaque(path) => { + let descr_pre = &format!("{}implementer{} of ", descr_pre, plural_suffix); + emit_must_use_untranslated(cx, path, descr_pre, descr_post, plural_len); + } + MustUsePath::TraitObject(path) => { + let descr_post = &format!(" trait object{}{}", plural_suffix, descr_post); + emit_must_use_untranslated(cx, path, descr_pre, descr_post, plural_len); + } + MustUsePath::TupleElement(elems) => { + for (index, path) in elems { + let descr_post = &format!(" in tuple element {}", index); + emit_must_use_untranslated(cx, path, descr_pre, descr_post, plural_len); + } + } + MustUsePath::Array(path, len) => { + let descr_pre = &format!("{}array{} of ", descr_pre, plural_suffix); + emit_must_use_untranslated( + cx, + path, + descr_pre, + descr_post, + plural_len.saturating_add(usize::try_from(*len).unwrap_or(usize::MAX)), + ); + } + MustUsePath::Closure(span) => { cx.struct_span_lint( UNUSED_MUST_USE, - span, + *span, fluent::lint_unused_closure, |lint| { // FIXME(davidtwco): this isn't properly translatable because of the @@ -298,12 +409,11 @@ impl<'tcx> LateLintPass<'tcx> for UnusedResults { .note(fluent::note) }, ); - true } - ty::Generator(..) => { + MustUsePath::Generator(span) => { cx.struct_span_lint( UNUSED_MUST_USE, - span, + *span, fluent::lint_unused_generator, |lint| { // FIXME(davidtwco): this isn't properly translatable because of the @@ -314,40 +424,20 @@ impl<'tcx> LateLintPass<'tcx> for UnusedResults { .note(fluent::note) }, ); - true } - _ => false, - } - } - - // Returns whether an error has been emitted (and thus another does not need to be later). - // FIXME: Args desc_{pre,post}_path could be made lazy by taking Fn() -> &str, but this - // would make calling it a big awkward. Could also take String (so args are moved), but - // this would still require a copy into the format string, which would only be executed - // when needed. - fn check_must_use_def( - cx: &LateContext<'_>, - def_id: DefId, - span: Span, - descr_pre_path: &str, - descr_post_path: &str, - ) -> bool { - if let Some(attr) = cx.tcx.get_attr(def_id, sym::must_use) { - cx.struct_span_lint(UNUSED_MUST_USE, span, fluent::lint_unused_def, |lint| { - // FIXME(davidtwco): this isn't properly translatable because of the pre/post - // strings - lint.set_arg("pre", descr_pre_path); - lint.set_arg("post", descr_post_path); - lint.set_arg("def", cx.tcx.def_path_str(def_id)); - // check for #[must_use = "..."] - if let Some(note) = attr.value_str() { - lint.note(note.as_str()); - } - lint - }); - true - } else { - false + MustUsePath::Def(span, def_id, reason) => { + cx.struct_span_lint(UNUSED_MUST_USE, *span, fluent::lint_unused_def, |lint| { + // FIXME(davidtwco): this isn't properly translatable because of the pre/post + // strings + lint.set_arg("pre", descr_pre); + lint.set_arg("post", descr_post); + lint.set_arg("def", cx.tcx.def_path_str(*def_id)); + if let Some(note) = reason { + lint.note(note.as_str()); + } + lint + }); + } } } } diff --git a/src/test/ui/lint/unused/must-use-ops.rs b/src/test/ui/lint/unused/must-use-ops.rs index 3e425727e78..60f877aa8b3 100644 --- a/src/test/ui/lint/unused/must-use-ops.rs +++ b/src/test/ui/lint/unused/must-use-ops.rs @@ -3,12 +3,18 @@ // check-pass #![warn(unused_must_use)] +#![feature(never_type)] + +fn deref_never(x: &!) { + // Don't lint for uninhabited typess + *x; +} fn main() { let val = 1; let val_pointer = &val; -// Comparison Operators + // Comparison Operators val == 1; //~ WARNING unused comparison val < 1; //~ WARNING unused comparison val <= 1; //~ WARNING unused comparison @@ -16,26 +22,30 @@ fn main() { val >= 1; //~ WARNING unused comparison val > 1; //~ WARNING unused comparison -// Arithmetic Operators + // Arithmetic Operators val + 2; //~ WARNING unused arithmetic operation val - 2; //~ WARNING unused arithmetic operation val / 2; //~ WARNING unused arithmetic operation val * 2; //~ WARNING unused arithmetic operation val % 2; //~ WARNING unused arithmetic operation -// Logical Operators + // Logical Operators true && true; //~ WARNING unused logical operation false || true; //~ WARNING unused logical operation -// Bitwise Operators + // Bitwise Operators 5 ^ val; //~ WARNING unused bitwise operation 5 & val; //~ WARNING unused bitwise operation 5 | val; //~ WARNING unused bitwise operation 5 << val; //~ WARNING unused bitwise operation 5 >> val; //~ WARNING unused bitwise operation -// Unary Operators + // Unary Operators !val; //~ WARNING unused unary operation -val; //~ WARNING unused unary operation *val_pointer; //~ WARNING unused unary operation + + if false { + deref_never(&panic!()); + } } diff --git a/src/test/ui/lint/unused/must-use-ops.stderr b/src/test/ui/lint/unused/must-use-ops.stderr index b248dd0fe15..79a53d39cbf 100644 --- a/src/test/ui/lint/unused/must-use-ops.stderr +++ b/src/test/ui/lint/unused/must-use-ops.stderr @@ -1,5 +1,5 @@ warning: unused comparison that must be used - --> $DIR/must-use-ops.rs:12:5 + --> $DIR/must-use-ops.rs:18:5 | LL | val == 1; | ^^^^^^^^ the comparison produces a value @@ -15,7 +15,7 @@ LL | let _ = val == 1; | +++++++ warning: unused comparison that must be used - --> $DIR/must-use-ops.rs:13:5 + --> $DIR/must-use-ops.rs:19:5 | LL | val < 1; | ^^^^^^^ the comparison produces a value @@ -26,7 +26,7 @@ LL | let _ = val < 1; | +++++++ warning: unused comparison that must be used - --> $DIR/must-use-ops.rs:14:5 + --> $DIR/must-use-ops.rs:20:5 | LL | val <= 1; | ^^^^^^^^ the comparison produces a value @@ -37,7 +37,7 @@ LL | let _ = val <= 1; | +++++++ warning: unused comparison that must be used - --> $DIR/must-use-ops.rs:15:5 + --> $DIR/must-use-ops.rs:21:5 | LL | val != 1; | ^^^^^^^^ the comparison produces a value @@ -48,7 +48,7 @@ LL | let _ = val != 1; | +++++++ warning: unused comparison that must be used - --> $DIR/must-use-ops.rs:16:5 + --> $DIR/must-use-ops.rs:22:5 | LL | val >= 1; | ^^^^^^^^ the comparison produces a value @@ -59,7 +59,7 @@ LL | let _ = val >= 1; | +++++++ warning: unused comparison that must be used - --> $DIR/must-use-ops.rs:17:5 + --> $DIR/must-use-ops.rs:23:5 | LL | val > 1; | ^^^^^^^ the comparison produces a value @@ -70,7 +70,7 @@ LL | let _ = val > 1; | +++++++ warning: unused arithmetic operation that must be used - --> $DIR/must-use-ops.rs:20:5 + --> $DIR/must-use-ops.rs:26:5 | LL | val + 2; | ^^^^^^^ the arithmetic operation produces a value @@ -81,7 +81,7 @@ LL | let _ = val + 2; | +++++++ warning: unused arithmetic operation that must be used - --> $DIR/must-use-ops.rs:21:5 + --> $DIR/must-use-ops.rs:27:5 | LL | val - 2; | ^^^^^^^ the arithmetic operation produces a value @@ -92,7 +92,7 @@ LL | let _ = val - 2; | +++++++ warning: unused arithmetic operation that must be used - --> $DIR/must-use-ops.rs:22:5 + --> $DIR/must-use-ops.rs:28:5 | LL | val / 2; | ^^^^^^^ the arithmetic operation produces a value @@ -103,7 +103,7 @@ LL | let _ = val / 2; | +++++++ warning: unused arithmetic operation that must be used - --> $DIR/must-use-ops.rs:23:5 + --> $DIR/must-use-ops.rs:29:5 | LL | val * 2; | ^^^^^^^ the arithmetic operation produces a value @@ -114,7 +114,7 @@ LL | let _ = val * 2; | +++++++ warning: unused arithmetic operation that must be used - --> $DIR/must-use-ops.rs:24:5 + --> $DIR/must-use-ops.rs:30:5 | LL | val % 2; | ^^^^^^^ the arithmetic operation produces a value @@ -125,7 +125,7 @@ LL | let _ = val % 2; | +++++++ warning: unused logical operation that must be used - --> $DIR/must-use-ops.rs:27:5 + --> $DIR/must-use-ops.rs:33:5 | LL | true && true; | ^^^^^^^^^^^^ the logical operation produces a value @@ -136,7 +136,7 @@ LL | let _ = true && true; | +++++++ warning: unused logical operation that must be used - --> $DIR/must-use-ops.rs:28:5 + --> $DIR/must-use-ops.rs:34:5 | LL | false || true; | ^^^^^^^^^^^^^ the logical operation produces a value @@ -147,7 +147,7 @@ LL | let _ = false || true; | +++++++ warning: unused bitwise operation that must be used - --> $DIR/must-use-ops.rs:31:5 + --> $DIR/must-use-ops.rs:37:5 | LL | 5 ^ val; | ^^^^^^^ the bitwise operation produces a value @@ -158,7 +158,7 @@ LL | let _ = 5 ^ val; | +++++++ warning: unused bitwise operation that must be used - --> $DIR/must-use-ops.rs:32:5 + --> $DIR/must-use-ops.rs:38:5 | LL | 5 & val; | ^^^^^^^ the bitwise operation produces a value @@ -169,7 +169,7 @@ LL | let _ = 5 & val; | +++++++ warning: unused bitwise operation that must be used - --> $DIR/must-use-ops.rs:33:5 + --> $DIR/must-use-ops.rs:39:5 | LL | 5 | val; | ^^^^^^^ the bitwise operation produces a value @@ -180,7 +180,7 @@ LL | let _ = 5 | val; | +++++++ warning: unused bitwise operation that must be used - --> $DIR/must-use-ops.rs:34:5 + --> $DIR/must-use-ops.rs:40:5 | LL | 5 << val; | ^^^^^^^^ the bitwise operation produces a value @@ -191,7 +191,7 @@ LL | let _ = 5 << val; | +++++++ warning: unused bitwise operation that must be used - --> $DIR/must-use-ops.rs:35:5 + --> $DIR/must-use-ops.rs:41:5 | LL | 5 >> val; | ^^^^^^^^ the bitwise operation produces a value @@ -202,7 +202,7 @@ LL | let _ = 5 >> val; | +++++++ warning: unused unary operation that must be used - --> $DIR/must-use-ops.rs:38:5 + --> $DIR/must-use-ops.rs:44:5 | LL | !val; | ^^^^ the unary operation produces a value @@ -213,7 +213,7 @@ LL | let _ = !val; | +++++++ warning: unused unary operation that must be used - --> $DIR/must-use-ops.rs:39:5 + --> $DIR/must-use-ops.rs:45:5 | LL | -val; | ^^^^ the unary operation produces a value @@ -224,7 +224,7 @@ LL | let _ = -val; | +++++++ warning: unused unary operation that must be used - --> $DIR/must-use-ops.rs:40:5 + --> $DIR/must-use-ops.rs:46:5 | LL | *val_pointer; | ^^^^^^^^^^^^ the unary operation produces a value diff --git a/src/test/ui/lint/unused/must_use-array.rs b/src/test/ui/lint/unused/must_use-array.rs index 97825dd2f6c..b7bae4b0acf 100644 --- a/src/test/ui/lint/unused/must_use-array.rs +++ b/src/test/ui/lint/unused/must_use-array.rs @@ -1,6 +1,7 @@ #![deny(unused_must_use)] #[must_use] +#[derive(Clone, Copy)] struct S; struct A; @@ -34,6 +35,10 @@ fn array_of_arrays_of_arrays() -> [[[S; 1]; 2]; 1] { [[[S], [S]]] } +fn usize_max() -> [S; usize::MAX] { + [S; usize::MAX] +} + fn main() { empty(); // ok singleton(); //~ ERROR unused array of `S` that must be used @@ -44,4 +49,6 @@ fn main() { //~^ ERROR unused array of boxed `T` trait objects in tuple element 1 that must be used array_of_arrays_of_arrays(); //~^ ERROR unused array of arrays of arrays of `S` that must be used + usize_max(); + //~^ ERROR unused array of `S` that must be used } diff --git a/src/test/ui/lint/unused/must_use-array.stderr b/src/test/ui/lint/unused/must_use-array.stderr index bba2b1ba078..61ef2088d30 100644 --- a/src/test/ui/lint/unused/must_use-array.stderr +++ b/src/test/ui/lint/unused/must_use-array.stderr @@ -1,5 +1,5 @@ error: unused array of `S` that must be used - --> $DIR/must_use-array.rs:39:5 + --> $DIR/must_use-array.rs:44:5 | LL | singleton(); | ^^^^^^^^^^^ @@ -11,34 +11,40 @@ LL | #![deny(unused_must_use)] | ^^^^^^^^^^^^^^^ error: unused array of `S` that must be used - --> $DIR/must_use-array.rs:40:5 + --> $DIR/must_use-array.rs:45:5 | LL | many(); | ^^^^^^ error: unused array of `S` in tuple element 0 that must be used - --> $DIR/must_use-array.rs:41:6 + --> $DIR/must_use-array.rs:46:6 | LL | ([S], 0, ()); | ^^^ error: unused array of implementers of `T` that must be used - --> $DIR/must_use-array.rs:42:5 + --> $DIR/must_use-array.rs:47:5 | LL | array_of_impl_trait(); | ^^^^^^^^^^^^^^^^^^^^^ error: unused array of boxed `T` trait objects in tuple element 1 that must be used - --> $DIR/must_use-array.rs:43:5 + --> $DIR/must_use-array.rs:48:5 | LL | impl_array(); | ^^^^^^^^^^^^ error: unused array of arrays of arrays of `S` that must be used - --> $DIR/must_use-array.rs:45:5 + --> $DIR/must_use-array.rs:50:5 | LL | array_of_arrays_of_arrays(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ -error: aborting due to 6 previous errors +error: unused array of `S` that must be used + --> $DIR/must_use-array.rs:52:5 + | +LL | usize_max(); + | ^^^^^^^^^^^ + +error: aborting due to 7 previous errors |