From b32b841ddbdf59d858ffd4f75ecf01a06c9dc98c Mon Sep 17 00:00:00 2001 From: Charlotte Ausel Date: Mon, 24 Aug 2026 13:06:03 +0100 Subject: [PATCH 1/7] lint against repeated repr attributes --- compiler/rustc_lint_defs/src/builtin.rs | 15 +++++++++ compiler/rustc_passes/src/check_attr.rs | 43 +++++++++++++++++++++--- compiler/rustc_passes/src/diagnostics.rs | 5 +++ 3 files changed, 59 insertions(+), 4 deletions(-) diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs index d7339d1b60269..af517fbd8f4d0 100644 --- a/compiler/rustc_lint_defs/src/builtin.rs +++ b/compiler/rustc_lint_defs/src/builtin.rs @@ -277,6 +277,21 @@ declare_lint! { }; } +declare_lint! { + /// Todo: explain this. + /// + /// ### Example + /// + /// TODO + /// + /// ### Explanation + /// + /// TODO + pub REPEATED_REPRS, + Warn, + "repeated `#[repr(..)]` attributes were inconsistently rejected before", +} + declare_lint! { /// The `meta_variable_misuse` lint detects possible meta-variable misuse /// in macro definitions. diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs index 7f9e4fc553455..5aeb1b3ec2a02 100644 --- a/compiler/rustc_passes/src/check_attr.rs +++ b/compiler/rustc_passes/src/check_attr.rs @@ -30,7 +30,8 @@ use rustc_hir::{ }; use rustc_lint_defs::builtin::{ CONFLICTING_REPR_HINTS, INVALID_DOC_ATTRIBUTES, MALFORMED_DIAGNOSTIC_ATTRIBUTES, - MALFORMED_DIAGNOSTIC_FORMAT_LITERALS, MISPLACED_DIAGNOSTIC_ATTRIBUTES, UNUSED_ATTRIBUTES, + MALFORMED_DIAGNOSTIC_FORMAT_LITERALS, MISPLACED_DIAGNOSTIC_ATTRIBUTES, REPEATED_REPRS, + UNUSED_ATTRIBUTES, }; use rustc_macros::Diagnostic; use rustc_middle::hir::nested_filter; @@ -1212,21 +1213,46 @@ impl<'tcx> CheckAttrVisitor<'tcx> { let mut is_c = false; let mut is_simd = false; let mut is_transparent = false; + let mut is_align = false; + let mut is_packed = false; + let mut repeated_repr = false; for (repr, _repr_span) in reprs { match repr { ReprAttr::ReprRust => { + if is_explicit_rust { + repeated_repr = true + } is_explicit_rust = true; } ReprAttr::ReprC => { + if is_c { + repeated_repr = true; + } is_c = true; } - ReprAttr::ReprAlign(..) => {} - ReprAttr::ReprPacked(_) => {} + ReprAttr::ReprAlign(..) => { + if is_align { + repeated_repr = true; + } + is_align = true; + } + ReprAttr::ReprPacked(..) => { + if is_packed { + repeated_repr = true; + } + is_packed = true; + } ReprAttr::ReprSimd => { + if is_simd { + repeated_repr = true; + } is_simd = true; } ReprAttr::ReprTransparent => { + if is_transparent { + repeated_repr = true; + } is_transparent = true; } ReprAttr::ReprInt(_) => { @@ -1270,10 +1296,19 @@ impl<'tcx> CheckAttrVisitor<'tcx> { self.tcx.emit_node_span_lint( CONFLICTING_REPR_HINTS, hir_id, - hint_spans.collect::>(), + hint_spans.clone().collect::>(), diagnostics::ReprConflictingLint, ); } + + if repeated_repr { + self.tcx.emit_node_span_lint( + REPEATED_REPRS, + hir_id, + hint_spans.collect::>(), + diagnostics::RepeatedRepr, + ); + } } /// Outputs an error for `#[allow_internal_unstable]` which can only be applied to macros. diff --git a/compiler/rustc_passes/src/diagnostics.rs b/compiler/rustc_passes/src/diagnostics.rs index 9864e9debf9d8..deae750ca2688 100644 --- a/compiler/rustc_passes/src/diagnostics.rs +++ b/compiler/rustc_passes/src/diagnostics.rs @@ -607,6 +607,11 @@ pub(crate) struct TransparentIncompatible { pub target: String, } +#[derive(Diagnostic)] +#[diag("attribute is specified more than once")] +#[note("will become a hard error soon. todo: wording")] +pub(crate) struct RepeatedRepr; + #[derive(Diagnostic)] #[diag("deprecated attribute must be paired with either stable or unstable attribute", code = E0549)] pub(crate) struct DeprecatedAttribute { From 1b2470e2cc3186cc3934877dbd0ae76ae41a416d Mon Sep 17 00:00:00 2001 From: Charlotte Ausel Date: Mon, 24 Aug 2026 13:06:11 +0100 Subject: [PATCH 2/7] bring back warns for repeated reprs, update tests had to update several tests which used repeated aligns and packeds. they now produce both a warning and an error where appropriate (e.g. when using conflicting packeds) which i think is correct. --- compiler/rustc_passes/src/check_attr.rs | 7 +-- tests/ui/attributes/issue-100631.rs | 1 + tests/ui/attributes/issue-100631.stderr | 16 ++++- tests/ui/lint/unused/unused-attr-duplicate.rs | 3 +- .../lint/unused/unused-attr-duplicate.stderr | 62 +++++++++++++------ tests/ui/repr/conflicting-repr-hints.rs | 6 +- tests/ui/repr/conflicting-repr-hints.stderr | 29 ++++++++- tests/ui/structs-enums/align-enum.rs | 2 +- tests/ui/structs-enums/align-enum.stderr | 15 +++++ tests/ui/structs-enums/align-struct.rs | 2 +- tests/ui/structs-enums/align-struct.stderr | 15 +++++ 11 files changed, 125 insertions(+), 33 deletions(-) create mode 100644 tests/ui/structs-enums/align-enum.stderr create mode 100644 tests/ui/structs-enums/align-struct.stderr diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs index 5aeb1b3ec2a02..ea045ac6465f3 100644 --- a/compiler/rustc_passes/src/check_attr.rs +++ b/compiler/rustc_passes/src/check_attr.rs @@ -1221,7 +1221,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> { match repr { ReprAttr::ReprRust => { if is_explicit_rust { - repeated_repr = true + repeated_repr = true; } is_explicit_rust = true; } @@ -1250,9 +1250,8 @@ impl<'tcx> CheckAttrVisitor<'tcx> { is_simd = true; } ReprAttr::ReprTransparent => { - if is_transparent { - repeated_repr = true; - } + // No need to check for repeated transparent because that is already checked + // when checking for any other attribute together with transparent. is_transparent = true; } ReprAttr::ReprInt(_) => { diff --git a/tests/ui/attributes/issue-100631.rs b/tests/ui/attributes/issue-100631.rs index 0fefcf83fd516..0f0eb235aae78 100644 --- a/tests/ui/attributes/issue-100631.rs +++ b/tests/ui/attributes/issue-100631.rs @@ -2,6 +2,7 @@ // can reasonably deal with multiple attributes. // `repr` will use `TyCtxt::get_attrs` since it's `DuplicatesOk`. #[repr(C)] //~ ERROR: unsupported representation for zero-variant enum [E0084] +//~^ WARN attribute is specified more than once #[repr(C)] enum Foo {} diff --git a/tests/ui/attributes/issue-100631.stderr b/tests/ui/attributes/issue-100631.stderr index b2bd0a9632513..8f9cc9defcde0 100644 --- a/tests/ui/attributes/issue-100631.stderr +++ b/tests/ui/attributes/issue-100631.stderr @@ -1,12 +1,24 @@ -error[E0084]: unsupported representation for zero-variant enum +warning: attribute is specified more than once --> $DIR/issue-100631.rs:4:8 | LL | #[repr(C)] | ^ +LL | LL | #[repr(C)] + | ^ + | + = note: will become a hard error soon. todo: wording + = note: `#[warn(repeated_reprs)]` on by default + +error[E0084]: unsupported representation for zero-variant enum + --> $DIR/issue-100631.rs:4:8 + | +LL | #[repr(C)] + | ^ +... LL | enum Foo {} | -------- zero-variant enum -error: aborting due to 1 previous error +error: aborting due to 1 previous error; 1 warning emitted For more information about this error, try `rustc --explain E0084`. diff --git a/tests/ui/lint/unused/unused-attr-duplicate.rs b/tests/ui/lint/unused/unused-attr-duplicate.rs index 54c040f4bcac4..6a1dfd702cf06 100644 --- a/tests/ui/lint/unused/unused-attr-duplicate.rs +++ b/tests/ui/lint/unused/unused-attr-duplicate.rs @@ -64,8 +64,7 @@ fn t1() {} #[must_use = "some message"] //~^ ERROR unused attribute //~| WARN this was previously accepted -// No warnings for #[repr], would require more logic. -#[repr(C)] +#[repr(C)] //~ WARN attribute is specified more than once #[repr(C)] #[non_exhaustive] #[non_exhaustive] //~ ERROR unused attribute diff --git a/tests/ui/lint/unused/unused-attr-duplicate.stderr b/tests/ui/lint/unused/unused-attr-duplicate.stderr index 3e4cb99a09e34..10a674cc03325 100644 --- a/tests/ui/lint/unused/unused-attr-duplicate.stderr +++ b/tests/ui/lint/unused/unused-attr-duplicate.stderr @@ -16,6 +16,17 @@ note: the lint level is defined here LL | #![deny(unused_attributes)] | ^^^^^^^^^^^^^^^^^ +warning: attribute is specified more than once + --> $DIR/unused-attr-duplicate.rs:67:8 + | +LL | #[repr(C)] + | ^ +LL | #[repr(C)] + | ^ + | + = note: will become a hard error soon. todo: wording + = note: `#[warn(repeated_reprs)]` on by default + error: unused attribute --> $DIR/unused-attr-duplicate.rs:14:1 | @@ -193,111 +204,124 @@ LL | #[must_use] = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! error: unused attribute - --> $DIR/unused-attr-duplicate.rs:71:1 + --> $DIR/unused-attr-duplicate.rs:70:1 | LL | #[non_exhaustive] | ^^^^^^^^^^^^^^^^^ help: remove this attribute | note: attribute also specified here - --> $DIR/unused-attr-duplicate.rs:70:1 + --> $DIR/unused-attr-duplicate.rs:69:1 | LL | #[non_exhaustive] | ^^^^^^^^^^^^^^^^^ error: unused attribute - --> $DIR/unused-attr-duplicate.rs:77:1 + --> $DIR/unused-attr-duplicate.rs:76:1 | LL | #[automatically_derived] | ^^^^^^^^^^^^^^^^^^^^^^^^ help: remove this attribute | note: attribute also specified here - --> $DIR/unused-attr-duplicate.rs:76:1 + --> $DIR/unused-attr-duplicate.rs:75:1 | LL | #[automatically_derived] | ^^^^^^^^^^^^^^^^^^^^^^^^ error: unused attribute - --> $DIR/unused-attr-duplicate.rs:81:1 + --> $DIR/unused-attr-duplicate.rs:80:1 | LL | #[inline(never)] | ^^^^^^^^^^^^^^^^ help: remove this attribute | note: attribute also specified here - --> $DIR/unused-attr-duplicate.rs:80:1 + --> $DIR/unused-attr-duplicate.rs:79:1 | LL | #[inline(always)] | ^^^^^^^^^^^^^^^^^ = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! error: unused attribute - --> $DIR/unused-attr-duplicate.rs:84:1 + --> $DIR/unused-attr-duplicate.rs:83:1 | LL | #[cold] | ^^^^^^^ help: remove this attribute | note: attribute also specified here - --> $DIR/unused-attr-duplicate.rs:83:1 + --> $DIR/unused-attr-duplicate.rs:82:1 | LL | #[cold] | ^^^^^^^ error: unused attribute - --> $DIR/unused-attr-duplicate.rs:86:1 + --> $DIR/unused-attr-duplicate.rs:85:1 | LL | #[track_caller] | ^^^^^^^^^^^^^^^ help: remove this attribute | note: attribute also specified here - --> $DIR/unused-attr-duplicate.rs:85:1 + --> $DIR/unused-attr-duplicate.rs:84:1 | LL | #[track_caller] | ^^^^^^^^^^^^^^^ error: unused attribute - --> $DIR/unused-attr-duplicate.rs:100:1 + --> $DIR/unused-attr-duplicate.rs:93:5 + | +LL | #[link_name = "rust_dbg_extern_identity_u32"] + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove this attribute + | +note: attribute also specified here + --> $DIR/unused-attr-duplicate.rs:92:5 + | +LL | #[link_name = "this_does_not_exist"] + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + +error: unused attribute + --> $DIR/unused-attr-duplicate.rs:99:1 | LL | #[export_name = "exported_symbol_name2"] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove this attribute | note: attribute also specified here - --> $DIR/unused-attr-duplicate.rs:99:1 + --> $DIR/unused-attr-duplicate.rs:98:1 | LL | #[export_name = "exported_symbol_name"] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! error: unused attribute - --> $DIR/unused-attr-duplicate.rs:105:1 + --> $DIR/unused-attr-duplicate.rs:104:1 | LL | #[no_mangle] | ^^^^^^^^^^^^ help: remove this attribute | note: attribute also specified here - --> $DIR/unused-attr-duplicate.rs:104:1 + --> $DIR/unused-attr-duplicate.rs:103:1 | LL | #[no_mangle] | ^^^^^^^^^^^^ error: unused attribute - --> $DIR/unused-attr-duplicate.rs:109:1 + --> $DIR/unused-attr-duplicate.rs:108:1 | LL | #[used] | ^^^^^^^ help: remove this attribute | note: attribute also specified here - --> $DIR/unused-attr-duplicate.rs:108:1 + --> $DIR/unused-attr-duplicate.rs:107:1 | LL | #[used] | ^^^^^^^ error: unused attribute - --> $DIR/unused-attr-duplicate.rs:113:1 + --> $DIR/unused-attr-duplicate.rs:112:1 | LL | #[link_section = "__DATA,__mod_init_func"] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove this attribute | note: attribute also specified here - --> $DIR/unused-attr-duplicate.rs:112:1 + --> $DIR/unused-attr-duplicate.rs:111:1 | LL | #[link_section = "__TEXT,__text"] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -316,5 +340,5 @@ LL | #[link_name = "this_does_not_exist"] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! -error: aborting due to 25 previous errors +error: aborting due to 25 previous errors; 1 warning emitted diff --git a/tests/ui/repr/conflicting-repr-hints.rs b/tests/ui/repr/conflicting-repr-hints.rs index ed82b6a742c8d..0ddcabef67972 100644 --- a/tests/ui/repr/conflicting-repr-hints.rs +++ b/tests/ui/repr/conflicting-repr-hints.rs @@ -36,14 +36,14 @@ struct G(i32); //~ ERROR type has conflicting packed and align representation hi #[repr(packed)] struct H(i32); //~ ERROR type has conflicting packed and align representation hints -#[repr(packed, packed(2))] +#[repr(packed, packed(2))] //~ WARN attribute is specified more than once struct I(i32); //~ ERROR type has conflicting packed representation hints -#[repr(packed(2))] +#[repr(packed(2))] //~ WARN attribute is specified more than once #[repr(packed)] struct J(i32); //~ ERROR type has conflicting packed representation hints -#[repr(packed, packed(1))] +#[repr(packed, packed(1))] //~ WARN attribute is specified more than once struct K(i32); #[repr(packed, align(8))] diff --git a/tests/ui/repr/conflicting-repr-hints.stderr b/tests/ui/repr/conflicting-repr-hints.stderr index 4da3d454e037d..77ff01a22caa5 100644 --- a/tests/ui/repr/conflicting-repr-hints.stderr +++ b/tests/ui/repr/conflicting-repr-hints.stderr @@ -17,6 +17,33 @@ LL | #[repr(u32, u64)] = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! = note: for more information, see issue #68585 +warning: attribute is specified more than once + --> $DIR/conflicting-repr-hints.rs:39:8 + | +LL | #[repr(packed, packed(2))] + | ^^^^^^ ^^^^^^^^^ + | + = note: will become a hard error soon. todo: wording + = note: `#[warn(repeated_reprs)]` on by default + +warning: attribute is specified more than once + --> $DIR/conflicting-repr-hints.rs:42:8 + | +LL | #[repr(packed(2))] + | ^^^^^^^^^ +LL | #[repr(packed)] + | ^^^^^^ + | + = note: will become a hard error soon. todo: wording + +warning: attribute is specified more than once + --> $DIR/conflicting-repr-hints.rs:46:8 + | +LL | #[repr(packed, packed(1))] + | ^^^^^^ ^^^^^^^^^ + | + = note: will become a hard error soon. todo: wording + error[E0587]: type has conflicting packed and align representation hints --> $DIR/conflicting-repr-hints.rs:29:1 | @@ -77,7 +104,7 @@ error[E0587]: type has conflicting packed and align representation hints LL | pub union U { | ^^^^^^^^^^^ -error: aborting due to 12 previous errors +error: aborting due to 12 previous errors; 3 warnings emitted Some errors have detailed explanations: E0566, E0587, E0634. For more information about an error, try `rustc --explain E0566`. diff --git a/tests/ui/structs-enums/align-enum.rs b/tests/ui/structs-enums/align-enum.rs index ff80a19211cda..c9652ac84db47 100644 --- a/tests/ui/structs-enums/align-enum.rs +++ b/tests/ui/structs-enums/align-enum.rs @@ -11,7 +11,7 @@ enum Align16 { } // Raise alignment by maximum -#[repr(align(1), align(16))] +#[repr(align(1), align(16))] //~ WARN attribute is specified more than once #[repr(align(32))] #[repr(align(4))] enum Align32 { diff --git a/tests/ui/structs-enums/align-enum.stderr b/tests/ui/structs-enums/align-enum.stderr new file mode 100644 index 0000000000000..25fec15cf2a12 --- /dev/null +++ b/tests/ui/structs-enums/align-enum.stderr @@ -0,0 +1,15 @@ +warning: attribute is specified more than once + --> $DIR/align-enum.rs:14:8 + | +LL | #[repr(align(1), align(16))] + | ^^^^^^^^ ^^^^^^^^^ +LL | #[repr(align(32))] + | ^^^^^^^^^ +LL | #[repr(align(4))] + | ^^^^^^^^ + | + = note: will become a hard error soon. todo: wording + = note: `#[warn(repeated_reprs)]` on by default + +warning: 1 warning emitted + diff --git a/tests/ui/structs-enums/align-struct.rs b/tests/ui/structs-enums/align-struct.rs index 3d8dad6e324e3..1b6d4dfa49755 100644 --- a/tests/ui/structs-enums/align-struct.rs +++ b/tests/ui/structs-enums/align-struct.rs @@ -13,7 +13,7 @@ struct Align16(i32); struct Align1(i32); // Multiple attributes take the max -#[repr(align(4))] +#[repr(align(4))] //~ WARN attribute is specified more than once #[repr(align(16))] #[repr(align(8))] struct AlignMany(i32); diff --git a/tests/ui/structs-enums/align-struct.stderr b/tests/ui/structs-enums/align-struct.stderr new file mode 100644 index 0000000000000..6aaafc8c7753d --- /dev/null +++ b/tests/ui/structs-enums/align-struct.stderr @@ -0,0 +1,15 @@ +warning: attribute is specified more than once + --> $DIR/align-struct.rs:16:8 + | +LL | #[repr(align(4))] + | ^^^^^^^^ +LL | #[repr(align(16))] + | ^^^^^^^^^ +LL | #[repr(align(8))] + | ^^^^^^^^ + | + = note: will become a hard error soon. todo: wording + = note: `#[warn(repeated_reprs)]` on by default + +warning: 1 warning emitted + From 6423eed93f6662dee0d087dd3f237de0aaca69b0 Mon Sep 17 00:00:00 2001 From: Charlotte Ausel Date: Mon, 24 Aug 2026 13:06:25 +0100 Subject: [PATCH 3/7] finish rewording lint messages --- compiler/rustc_lint_defs/src/builtin.rs | 15 +++++++++++---- compiler/rustc_passes/src/diagnostics.rs | 4 ++-- tests/ui/attributes/issue-100631.rs | 2 +- tests/ui/attributes/issue-100631.stderr | 4 ++-- tests/ui/lint/unused/unused-attr-duplicate.rs | 2 +- tests/ui/lint/unused/unused-attr-duplicate.stderr | 4 ++-- tests/ui/repr/conflicting-repr-hints.rs | 4 ++-- tests/ui/repr/conflicting-repr-hints.stderr | 12 ++++++------ tests/ui/structs-enums/align-enum.rs | 2 +- tests/ui/structs-enums/align-enum.stderr | 4 ++-- tests/ui/structs-enums/align-struct.rs | 2 +- tests/ui/structs-enums/align-struct.stderr | 4 ++-- 12 files changed, 33 insertions(+), 26 deletions(-) diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs index af517fbd8f4d0..811536a5f221e 100644 --- a/compiler/rustc_lint_defs/src/builtin.rs +++ b/compiler/rustc_lint_defs/src/builtin.rs @@ -278,18 +278,25 @@ declare_lint! { } declare_lint! { - /// Todo: explain this. + /// The `repeated_reprs` lint detects when the same representation is + /// specified more than once in a `#[repr(..)]` attribute. /// /// ### Example /// - /// TODO + /// ```rust + /// #[repr(C)] + /// #[repr(C)] + /// enum Foo { A } + /// ``` /// /// ### Explanation /// - /// TODO + /// While some representations may be specified more than once, the compiler + /// will reject repeated uses of some others. For consistency, prefer to + /// only specify the representation once. pub REPEATED_REPRS, Warn, - "repeated `#[repr(..)]` attributes were inconsistently rejected before", + "detects repeated representations in `#[repr(..)]` attributes", } declare_lint! { diff --git a/compiler/rustc_passes/src/diagnostics.rs b/compiler/rustc_passes/src/diagnostics.rs index deae750ca2688..2f4900a6b47a7 100644 --- a/compiler/rustc_passes/src/diagnostics.rs +++ b/compiler/rustc_passes/src/diagnostics.rs @@ -608,8 +608,8 @@ pub(crate) struct TransparentIncompatible { } #[derive(Diagnostic)] -#[diag("attribute is specified more than once")] -#[note("will become a hard error soon. todo: wording")] +#[diag("representation attribute is specified more than once")] +#[note("for consistency, only specify the representation once")] pub(crate) struct RepeatedRepr; #[derive(Diagnostic)] diff --git a/tests/ui/attributes/issue-100631.rs b/tests/ui/attributes/issue-100631.rs index 0f0eb235aae78..d496231c73026 100644 --- a/tests/ui/attributes/issue-100631.rs +++ b/tests/ui/attributes/issue-100631.rs @@ -2,7 +2,7 @@ // can reasonably deal with multiple attributes. // `repr` will use `TyCtxt::get_attrs` since it's `DuplicatesOk`. #[repr(C)] //~ ERROR: unsupported representation for zero-variant enum [E0084] -//~^ WARN attribute is specified more than once +//~^ WARN representation attribute is specified more than once #[repr(C)] enum Foo {} diff --git a/tests/ui/attributes/issue-100631.stderr b/tests/ui/attributes/issue-100631.stderr index 8f9cc9defcde0..66e08738eb02c 100644 --- a/tests/ui/attributes/issue-100631.stderr +++ b/tests/ui/attributes/issue-100631.stderr @@ -1,4 +1,4 @@ -warning: attribute is specified more than once +warning: representation attribute is specified more than once --> $DIR/issue-100631.rs:4:8 | LL | #[repr(C)] @@ -7,7 +7,7 @@ LL | LL | #[repr(C)] | ^ | - = note: will become a hard error soon. todo: wording + = note: for consistency, only specify the representation once = note: `#[warn(repeated_reprs)]` on by default error[E0084]: unsupported representation for zero-variant enum diff --git a/tests/ui/lint/unused/unused-attr-duplicate.rs b/tests/ui/lint/unused/unused-attr-duplicate.rs index 6a1dfd702cf06..348c9590e8b27 100644 --- a/tests/ui/lint/unused/unused-attr-duplicate.rs +++ b/tests/ui/lint/unused/unused-attr-duplicate.rs @@ -64,7 +64,7 @@ fn t1() {} #[must_use = "some message"] //~^ ERROR unused attribute //~| WARN this was previously accepted -#[repr(C)] //~ WARN attribute is specified more than once +#[repr(C)] //~ WARN representation attribute is specified more than once #[repr(C)] #[non_exhaustive] #[non_exhaustive] //~ ERROR unused attribute diff --git a/tests/ui/lint/unused/unused-attr-duplicate.stderr b/tests/ui/lint/unused/unused-attr-duplicate.stderr index 10a674cc03325..93f7a4791188f 100644 --- a/tests/ui/lint/unused/unused-attr-duplicate.stderr +++ b/tests/ui/lint/unused/unused-attr-duplicate.stderr @@ -16,7 +16,7 @@ note: the lint level is defined here LL | #![deny(unused_attributes)] | ^^^^^^^^^^^^^^^^^ -warning: attribute is specified more than once +warning: representation attribute is specified more than once --> $DIR/unused-attr-duplicate.rs:67:8 | LL | #[repr(C)] @@ -24,7 +24,7 @@ LL | #[repr(C)] LL | #[repr(C)] | ^ | - = note: will become a hard error soon. todo: wording + = note: for consistency, only specify the representation once = note: `#[warn(repeated_reprs)]` on by default error: unused attribute diff --git a/tests/ui/repr/conflicting-repr-hints.rs b/tests/ui/repr/conflicting-repr-hints.rs index 0ddcabef67972..032f2b2e6c608 100644 --- a/tests/ui/repr/conflicting-repr-hints.rs +++ b/tests/ui/repr/conflicting-repr-hints.rs @@ -36,10 +36,10 @@ struct G(i32); //~ ERROR type has conflicting packed and align representation hi #[repr(packed)] struct H(i32); //~ ERROR type has conflicting packed and align representation hints -#[repr(packed, packed(2))] //~ WARN attribute is specified more than once +#[repr(packed, packed(2))] //~ WARN representation attribute is specified more than once struct I(i32); //~ ERROR type has conflicting packed representation hints -#[repr(packed(2))] //~ WARN attribute is specified more than once +#[repr(packed(2))] //~ WARN representation attribute is specified more than once #[repr(packed)] struct J(i32); //~ ERROR type has conflicting packed representation hints diff --git a/tests/ui/repr/conflicting-repr-hints.stderr b/tests/ui/repr/conflicting-repr-hints.stderr index 77ff01a22caa5..a99546b754785 100644 --- a/tests/ui/repr/conflicting-repr-hints.stderr +++ b/tests/ui/repr/conflicting-repr-hints.stderr @@ -17,16 +17,16 @@ LL | #[repr(u32, u64)] = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! = note: for more information, see issue #68585 -warning: attribute is specified more than once +warning: representation attribute is specified more than once --> $DIR/conflicting-repr-hints.rs:39:8 | LL | #[repr(packed, packed(2))] | ^^^^^^ ^^^^^^^^^ | - = note: will become a hard error soon. todo: wording + = note: for consistency, only specify the representation once = note: `#[warn(repeated_reprs)]` on by default -warning: attribute is specified more than once +warning: representation attribute is specified more than once --> $DIR/conflicting-repr-hints.rs:42:8 | LL | #[repr(packed(2))] @@ -34,15 +34,15 @@ LL | #[repr(packed(2))] LL | #[repr(packed)] | ^^^^^^ | - = note: will become a hard error soon. todo: wording + = note: for consistency, only specify the representation once -warning: attribute is specified more than once +warning: representation attribute is specified more than once --> $DIR/conflicting-repr-hints.rs:46:8 | LL | #[repr(packed, packed(1))] | ^^^^^^ ^^^^^^^^^ | - = note: will become a hard error soon. todo: wording + = note: for consistency, only specify the representation once error[E0587]: type has conflicting packed and align representation hints --> $DIR/conflicting-repr-hints.rs:29:1 diff --git a/tests/ui/structs-enums/align-enum.rs b/tests/ui/structs-enums/align-enum.rs index c9652ac84db47..a635af7352afe 100644 --- a/tests/ui/structs-enums/align-enum.rs +++ b/tests/ui/structs-enums/align-enum.rs @@ -11,7 +11,7 @@ enum Align16 { } // Raise alignment by maximum -#[repr(align(1), align(16))] //~ WARN attribute is specified more than once +#[repr(align(1), align(16))] //~ WARN representation attribute is specified more than once #[repr(align(32))] #[repr(align(4))] enum Align32 { diff --git a/tests/ui/structs-enums/align-enum.stderr b/tests/ui/structs-enums/align-enum.stderr index 25fec15cf2a12..9b8c9842f81df 100644 --- a/tests/ui/structs-enums/align-enum.stderr +++ b/tests/ui/structs-enums/align-enum.stderr @@ -1,4 +1,4 @@ -warning: attribute is specified more than once +warning: representation attribute is specified more than once --> $DIR/align-enum.rs:14:8 | LL | #[repr(align(1), align(16))] @@ -8,7 +8,7 @@ LL | #[repr(align(32))] LL | #[repr(align(4))] | ^^^^^^^^ | - = note: will become a hard error soon. todo: wording + = note: for consistency, only specify the representation once = note: `#[warn(repeated_reprs)]` on by default warning: 1 warning emitted diff --git a/tests/ui/structs-enums/align-struct.rs b/tests/ui/structs-enums/align-struct.rs index 1b6d4dfa49755..2d1ebf6731a62 100644 --- a/tests/ui/structs-enums/align-struct.rs +++ b/tests/ui/structs-enums/align-struct.rs @@ -13,7 +13,7 @@ struct Align16(i32); struct Align1(i32); // Multiple attributes take the max -#[repr(align(4))] //~ WARN attribute is specified more than once +#[repr(align(4))] //~ WARN representation attribute is specified more than once #[repr(align(16))] #[repr(align(8))] struct AlignMany(i32); diff --git a/tests/ui/structs-enums/align-struct.stderr b/tests/ui/structs-enums/align-struct.stderr index 6aaafc8c7753d..f54e9cd14cd8b 100644 --- a/tests/ui/structs-enums/align-struct.stderr +++ b/tests/ui/structs-enums/align-struct.stderr @@ -1,4 +1,4 @@ -warning: attribute is specified more than once +warning: representation attribute is specified more than once --> $DIR/align-struct.rs:16:8 | LL | #[repr(align(4))] @@ -8,7 +8,7 @@ LL | #[repr(align(16))] LL | #[repr(align(8))] | ^^^^^^^^ | - = note: will become a hard error soon. todo: wording + = note: for consistency, only specify the representation once = note: `#[warn(repeated_reprs)]` on by default warning: 1 warning emitted From deb81605189b7df985187428eb2ef9f934e2804d Mon Sep 17 00:00:00 2001 From: Charlotte Ausel Date: Mon, 24 Aug 2026 13:06:29 +0100 Subject: [PATCH 4/7] add another test --- compiler/rustc_lint_defs/src/builtin.rs | 2 + tests/ui/repr/repr-repeated-attrs.rs | 68 ++++++++ tests/ui/repr/repr-repeated-attrs.stderr | 200 +++++++++++++++++++++++ 3 files changed, 270 insertions(+) create mode 100644 tests/ui/repr/repr-repeated-attrs.rs create mode 100644 tests/ui/repr/repr-repeated-attrs.stderr diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs index 811536a5f221e..11cdbea3c426a 100644 --- a/compiler/rustc_lint_defs/src/builtin.rs +++ b/compiler/rustc_lint_defs/src/builtin.rs @@ -289,6 +289,8 @@ declare_lint! { /// enum Foo { A } /// ``` /// + /// {{produces}} + /// /// ### Explanation /// /// While some representations may be specified more than once, the compiler diff --git a/tests/ui/repr/repr-repeated-attrs.rs b/tests/ui/repr/repr-repeated-attrs.rs new file mode 100644 index 0000000000000..a6dd3fb6e8b15 --- /dev/null +++ b/tests/ui/repr/repr-repeated-attrs.rs @@ -0,0 +1,68 @@ +// Tests to ensure we warn on repeated `#[repr(..)]` attributes. + +#[repr(transparent, transparent)] +//~^ ERROR transparent struct cannot have other repr hints +#[repr(transparent)] +struct SeveralTransparentReprs(*mut u8); + +#[repr(transparent)] +//~^ ERROR transparent struct cannot have other repr hints +#[repr(transparent)] +struct MultilineOnly(*mut u8); + +#[repr(Rust, Rust)] +//~^ WARN representation attribute is specified more than once +struct SeveralRustReprs(u8); + +#[repr(C, C)] +//~^ WARN representation attribute is specified more than once +#[repr(C, C, C)] +struct SeveralC(u8); + +#[repr(u8, u8)] +//~^ ERROR conflicting representation hints +//~| WARN this was previously accepted +enum SeveralPrimitiveRerprs { + Variant, +} + +#[repr(C, C, u8)] //~ WARN representation attribute is specified more than once +//~^ ERROR conflicting representation hints +//~| WARN this was previously accepted +#[repr(C, u8, u8)] +enum SeveralCAndPrims { + Variant(u8), +} + +#[repr(Rust, u8, u8)] +//~^ ERROR conflicting representation hints +//~^^ ERROR conflicting representation hints +//~| WARN this was previously accepted +enum RustAndPrimDisallowed { + Variant(u8), +} + +#[repr(u8, u8)] //~ ERROR conflicting representation hints +//~^ WARN this was previously accepted +#[repr(u16)] +enum ConflictingPrimReprs { + Variant, +} + +#[repr(C, u8)] +//~^ ERROR conflicting representation hints +//~| WARN this was previously accepted +enum CWithIntsCausesFCW1 { + A, + B, +} + +#[repr(C, C, u8, u8, u8)] //~ WARN representation attribute is specified more than once +//~^ ERROR conflicting representation hints +//~| WARN this was previously accepted +enum CWithIntsCausesFCW2 { + A, + B, +} + +fn main() {} diff --git a/tests/ui/repr/repr-repeated-attrs.stderr b/tests/ui/repr/repr-repeated-attrs.stderr new file mode 100644 index 0000000000000..72c312a13ea11 --- /dev/null +++ b/tests/ui/repr/repr-repeated-attrs.stderr @@ -0,0 +1,200 @@ +error[E0692]: transparent struct cannot have other repr hints + --> $DIR/repr-repeated-attrs.rs:3:8 + | +LL | #[repr(transparent, transparent)] + | ^^^^^^^^^^^ ^^^^^^^^^^^ +LL | +LL | #[repr(transparent)] + | ^^^^^^^^^^^ + +error[E0692]: transparent struct cannot have other repr hints + --> $DIR/repr-repeated-attrs.rs:8:8 + | +LL | #[repr(transparent)] + | ^^^^^^^^^^^ +LL | +LL | #[repr(transparent)] + | ^^^^^^^^^^^ + +warning: representation attribute is specified more than once + --> $DIR/repr-repeated-attrs.rs:13:8 + | +LL | #[repr(Rust, Rust)] + | ^^^^ ^^^^ + | + = note: for consistency, only specify the representation once + = note: `#[warn(repeated_reprs)]` on by default + +warning: representation attribute is specified more than once + --> $DIR/repr-repeated-attrs.rs:17:8 + | +LL | #[repr(C, C)] + | ^ ^ +LL | +LL | #[repr(C, C, C)] + | ^ ^ ^ + | + = note: for consistency, only specify the representation once + +error[E0566]: conflicting representation hints + --> $DIR/repr-repeated-attrs.rs:22:8 + | +LL | #[repr(u8, u8)] + | ^^ ^^ + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #68585 + = note: `#[deny(conflicting_repr_hints)]` (part of `#[deny(future_incompatible)]`) on by default + +error[E0566]: conflicting representation hints + --> $DIR/repr-repeated-attrs.rs:29:8 + | +LL | #[repr(C, C, u8)] + | ^ ^ ^^ +... +LL | #[repr(C, u8, u8)] + | ^ ^^ ^^ + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #68585 + +warning: representation attribute is specified more than once + --> $DIR/repr-repeated-attrs.rs:29:8 + | +LL | #[repr(C, C, u8)] + | ^ ^ ^^ +... +LL | #[repr(C, u8, u8)] + | ^ ^^ ^^ + | + = note: for consistency, only specify the representation once + +error[E0566]: conflicting representation hints + --> $DIR/repr-repeated-attrs.rs:37:8 + | +LL | #[repr(Rust, u8, u8)] + | ^^^^ ^^ ^^ + +error[E0566]: conflicting representation hints + --> $DIR/repr-repeated-attrs.rs:37:8 + | +LL | #[repr(Rust, u8, u8)] + | ^^^^ ^^ ^^ + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #68585 + +error[E0566]: conflicting representation hints + --> $DIR/repr-repeated-attrs.rs:44:8 + | +LL | #[repr(u8, u8)] + | ^^ ^^ +LL | +LL | #[repr(u16)] + | ^^^ + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #68585 + +error[E0566]: conflicting representation hints + --> $DIR/repr-repeated-attrs.rs:51:8 + | +LL | #[repr(C, u8)] + | ^ ^^ + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #68585 + +error[E0566]: conflicting representation hints + --> $DIR/repr-repeated-attrs.rs:59:8 + | +LL | #[repr(C, C, u8, u8, u8)] + | ^ ^ ^^ ^^ ^^ + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #68585 + +warning: representation attribute is specified more than once + --> $DIR/repr-repeated-attrs.rs:59:8 + | +LL | #[repr(C, C, u8, u8, u8)] + | ^ ^ ^^ ^^ ^^ + | + = note: for consistency, only specify the representation once + +error: aborting due to 9 previous errors; 4 warnings emitted + +Some errors have detailed explanations: E0566, E0692. +For more information about an error, try `rustc --explain E0566`. +Future incompatibility report: Future breakage diagnostic: +error[E0566]: conflicting representation hints + --> $DIR/repr-repeated-attrs.rs:22:8 + | +LL | #[repr(u8, u8)] + | ^^ ^^ + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #68585 + = note: `#[deny(conflicting_repr_hints)]` (part of `#[deny(future_incompatible)]`) on by default + +Future breakage diagnostic: +error[E0566]: conflicting representation hints + --> $DIR/repr-repeated-attrs.rs:29:8 + | +LL | #[repr(C, C, u8)] + | ^ ^ ^^ +... +LL | #[repr(C, u8, u8)] + | ^ ^^ ^^ + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #68585 + = note: `#[deny(conflicting_repr_hints)]` (part of `#[deny(future_incompatible)]`) on by default + +Future breakage diagnostic: +error[E0566]: conflicting representation hints + --> $DIR/repr-repeated-attrs.rs:37:8 + | +LL | #[repr(Rust, u8, u8)] + | ^^^^ ^^ ^^ + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #68585 + = note: `#[deny(conflicting_repr_hints)]` (part of `#[deny(future_incompatible)]`) on by default + +Future breakage diagnostic: +error[E0566]: conflicting representation hints + --> $DIR/repr-repeated-attrs.rs:44:8 + | +LL | #[repr(u8, u8)] + | ^^ ^^ +LL | +LL | #[repr(u16)] + | ^^^ + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #68585 + = note: `#[deny(conflicting_repr_hints)]` (part of `#[deny(future_incompatible)]`) on by default + +Future breakage diagnostic: +error[E0566]: conflicting representation hints + --> $DIR/repr-repeated-attrs.rs:51:8 + | +LL | #[repr(C, u8)] + | ^ ^^ + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #68585 + = note: `#[deny(conflicting_repr_hints)]` (part of `#[deny(future_incompatible)]`) on by default + +Future breakage diagnostic: +error[E0566]: conflicting representation hints + --> $DIR/repr-repeated-attrs.rs:59:8 + | +LL | #[repr(C, C, u8, u8, u8)] + | ^ ^ ^^ ^^ ^^ + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #68585 + = note: `#[deny(conflicting_repr_hints)]` (part of `#[deny(future_incompatible)]`) on by default + From 4f5002db4e071f169e670097913a63f16f305492 Mon Sep 17 00:00:00 2001 From: Charlotte Ausel Date: Mon, 24 Aug 2026 13:06:37 +0100 Subject: [PATCH 5/7] also warn on repeated int reprs --- compiler/rustc_passes/src/check_attr.rs | 13 ++++++- tests/ui/repr/repr-repeated-attrs.rs | 9 +++-- tests/ui/repr/repr-repeated-attrs.stderr | 47 +++++++++++++++++++----- 3 files changed, 54 insertions(+), 15 deletions(-) diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs index ea045ac6465f3..b196ae1e5a82e 100644 --- a/compiler/rustc_passes/src/check_attr.rs +++ b/compiler/rustc_passes/src/check_attr.rs @@ -1216,6 +1216,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> { let mut is_align = false; let mut is_packed = false; let mut repeated_repr = false; + let mut maybe_last_int_type = None; for (repr, _repr_span) in reprs { match repr { @@ -1254,7 +1255,17 @@ impl<'tcx> CheckAttrVisitor<'tcx> { // when checking for any other attribute together with transparent. is_transparent = true; } - ReprAttr::ReprInt(_) => { + ReprAttr::ReprInt(int_type) => { + if let Some(last_int_type) = maybe_last_int_type + && last_int_type == int_type + { + // We'll "miss" detecting repeated int reprs if the user specifies + // #[repr(u8, u64, u8)] for example. But that's okay because we've got + // conflicting reprs anyway so it's not worth the effort to do more precise + // tracking. + repeated_repr = true; + } + maybe_last_int_type = Some(int_type); int_reprs += 1; } }; diff --git a/tests/ui/repr/repr-repeated-attrs.rs b/tests/ui/repr/repr-repeated-attrs.rs index a6dd3fb6e8b15..61e3ba05625d8 100644 --- a/tests/ui/repr/repr-repeated-attrs.rs +++ b/tests/ui/repr/repr-repeated-attrs.rs @@ -19,7 +19,7 @@ struct SeveralRustReprs(u8); #[repr(C, C, C)] struct SeveralC(u8); -#[repr(u8, u8)] +#[repr(u8, u8)] //~ WARN representation attribute is specified more than once //~^ ERROR conflicting representation hints //~| WARN this was previously accepted enum SeveralPrimitiveRerprs { @@ -34,7 +34,7 @@ enum SeveralCAndPrims { Variant(u8), } -#[repr(Rust, u8, u8)] +#[repr(Rust, u8, u8)] //~ WARN representation attribute is specified more than once //~^ ERROR conflicting representation hints //~^^ ERROR conflicting representation hints //~| WARN this was previously accepted @@ -42,8 +42,9 @@ enum RustAndPrimDisallowed { Variant(u8), } -#[repr(u8, u8)] //~ ERROR conflicting representation hints -//~^ WARN this was previously accepted +#[repr(u8, u8)] //~ WARN representation attribute is specified more than once +//~^ ERROR conflicting representation hints +//~| WARN this was previously accepted #[repr(u16)] enum ConflictingPrimReprs { Variant, diff --git a/tests/ui/repr/repr-repeated-attrs.stderr b/tests/ui/repr/repr-repeated-attrs.stderr index 72c312a13ea11..57af8ec804d76 100644 --- a/tests/ui/repr/repr-repeated-attrs.stderr +++ b/tests/ui/repr/repr-repeated-attrs.stderr @@ -46,6 +46,14 @@ LL | #[repr(u8, u8)] = note: for more information, see issue #68585 = note: `#[deny(conflicting_repr_hints)]` (part of `#[deny(future_incompatible)]`) on by default +warning: representation attribute is specified more than once + --> $DIR/repr-repeated-attrs.rs:22:8 + | +LL | #[repr(u8, u8)] + | ^^ ^^ + | + = note: for consistency, only specify the representation once + error[E0566]: conflicting representation hints --> $DIR/repr-repeated-attrs.rs:29:8 | @@ -84,20 +92,39 @@ LL | #[repr(Rust, u8, u8)] = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! = note: for more information, see issue #68585 +warning: representation attribute is specified more than once + --> $DIR/repr-repeated-attrs.rs:37:8 + | +LL | #[repr(Rust, u8, u8)] + | ^^^^ ^^ ^^ + | + = note: for consistency, only specify the representation once + error[E0566]: conflicting representation hints - --> $DIR/repr-repeated-attrs.rs:44:8 + --> $DIR/repr-repeated-attrs.rs:45:8 | LL | #[repr(u8, u8)] | ^^ ^^ -LL | +... LL | #[repr(u16)] | ^^^ | = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! = note: for more information, see issue #68585 +warning: representation attribute is specified more than once + --> $DIR/repr-repeated-attrs.rs:45:8 + | +LL | #[repr(u8, u8)] + | ^^ ^^ +... +LL | #[repr(u16)] + | ^^^ + | + = note: for consistency, only specify the representation once + error[E0566]: conflicting representation hints - --> $DIR/repr-repeated-attrs.rs:51:8 + --> $DIR/repr-repeated-attrs.rs:53:8 | LL | #[repr(C, u8)] | ^ ^^ @@ -106,7 +133,7 @@ LL | #[repr(C, u8)] = note: for more information, see issue #68585 error[E0566]: conflicting representation hints - --> $DIR/repr-repeated-attrs.rs:59:8 + --> $DIR/repr-repeated-attrs.rs:61:8 | LL | #[repr(C, C, u8, u8, u8)] | ^ ^ ^^ ^^ ^^ @@ -115,14 +142,14 @@ LL | #[repr(C, C, u8, u8, u8)] = note: for more information, see issue #68585 warning: representation attribute is specified more than once - --> $DIR/repr-repeated-attrs.rs:59:8 + --> $DIR/repr-repeated-attrs.rs:61:8 | LL | #[repr(C, C, u8, u8, u8)] | ^ ^ ^^ ^^ ^^ | = note: for consistency, only specify the representation once -error: aborting due to 9 previous errors; 4 warnings emitted +error: aborting due to 9 previous errors; 7 warnings emitted Some errors have detailed explanations: E0566, E0692. For more information about an error, try `rustc --explain E0566`. @@ -164,11 +191,11 @@ LL | #[repr(Rust, u8, u8)] Future breakage diagnostic: error[E0566]: conflicting representation hints - --> $DIR/repr-repeated-attrs.rs:44:8 + --> $DIR/repr-repeated-attrs.rs:45:8 | LL | #[repr(u8, u8)] | ^^ ^^ -LL | +... LL | #[repr(u16)] | ^^^ | @@ -178,7 +205,7 @@ LL | #[repr(u16)] Future breakage diagnostic: error[E0566]: conflicting representation hints - --> $DIR/repr-repeated-attrs.rs:51:8 + --> $DIR/repr-repeated-attrs.rs:53:8 | LL | #[repr(C, u8)] | ^ ^^ @@ -189,7 +216,7 @@ LL | #[repr(C, u8)] Future breakage diagnostic: error[E0566]: conflicting representation hints - --> $DIR/repr-repeated-attrs.rs:59:8 + --> $DIR/repr-repeated-attrs.rs:61:8 | LL | #[repr(C, C, u8, u8, u8)] | ^ ^ ^^ ^^ ^^ From 819099b56c2c69e5ed886b4b4f1c572beefa749d Mon Sep 17 00:00:00 2001 From: Charlotte Ausel Date: Mon, 24 Aug 2026 13:06:47 +0100 Subject: [PATCH 6/7] use sort/chunk_by to find repeated reprs --- compiler/rustc_attr_ir/src/data_structures.rs | 16 +++- compiler/rustc_passes/src/check_attr.rs | 81 +++++++---------- compiler/rustc_passes/src/diagnostics.rs | 2 +- tests/ui/attributes/issue-100631.rs | 2 +- tests/ui/attributes/issue-100631.stderr | 2 +- tests/ui/lint/unused/unused-attr-duplicate.rs | 2 +- .../lint/unused/unused-attr-duplicate.stderr | 19 +--- tests/ui/repr/conflicting-repr-hints.rs | 4 +- tests/ui/repr/conflicting-repr-hints.stderr | 24 +---- tests/ui/repr/repr-repeated-attrs.rs | 18 ++-- tests/ui/repr/repr-repeated-attrs.stderr | 87 +++++++++++-------- tests/ui/structs-enums/align-enum.rs | 2 +- tests/ui/structs-enums/align-enum.stderr | 15 ---- tests/ui/structs-enums/align-struct.rs | 2 +- tests/ui/structs-enums/align-struct.stderr | 15 ---- 15 files changed, 123 insertions(+), 168 deletions(-) delete mode 100644 tests/ui/structs-enums/align-enum.stderr delete mode 100644 tests/ui/structs-enums/align-struct.stderr diff --git a/compiler/rustc_attr_ir/src/data_structures.rs b/compiler/rustc_attr_ir/src/data_structures.rs index 195712559782d..28e90ea4f52b4 100644 --- a/compiler/rustc_attr_ir/src/data_structures.rs +++ b/compiler/rustc_attr_ir/src/data_structures.rs @@ -172,7 +172,19 @@ impl OptimizeAttr { } } -#[derive(PartialEq, Debug, Encodable, Decodable, Copy, Clone, StableHash, PrintAttribute)] +#[derive( + PartialEq, + Eq, + Debug, + PartialOrd, + Ord, + Encodable, + Decodable, + Copy, + Clone, + StableHash, + PrintAttribute +)] pub enum ReprAttr { ReprInt(IntType), ReprRust, @@ -188,7 +200,7 @@ pub enum TransparencyError { MultipleTransparencyAttrs(Span, Span), } -#[derive(Eq, PartialEq, Debug, Copy, Clone)] +#[derive(Eq, PartialEq, Debug, Copy, Clone, PartialOrd, Ord)] #[derive(Encodable, Decodable, StableHash, PrintAttribute)] pub enum IntType { SignedInt(ast::IntTy), diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs index b196ae1e5a82e..e4ee552d5bd0e 100644 --- a/compiler/rustc_passes/src/check_attr.rs +++ b/compiler/rustc_passes/src/check_attr.rs @@ -1213,64 +1213,58 @@ impl<'tcx> CheckAttrVisitor<'tcx> { let mut is_c = false; let mut is_simd = false; let mut is_transparent = false; - let mut is_align = false; - let mut is_packed = false; - let mut repeated_repr = false; - let mut maybe_last_int_type = None; for (repr, _repr_span) in reprs { match repr { ReprAttr::ReprRust => { - if is_explicit_rust { - repeated_repr = true; - } is_explicit_rust = true; } ReprAttr::ReprC => { - if is_c { - repeated_repr = true; - } is_c = true; } - ReprAttr::ReprAlign(..) => { - if is_align { - repeated_repr = true; - } - is_align = true; - } - ReprAttr::ReprPacked(..) => { - if is_packed { - repeated_repr = true; - } - is_packed = true; - } + ReprAttr::ReprAlign(..) => (), + ReprAttr::ReprPacked(..) => (), ReprAttr::ReprSimd => { - if is_simd { - repeated_repr = true; - } is_simd = true; } ReprAttr::ReprTransparent => { - // No need to check for repeated transparent because that is already checked - // when checking for any other attribute together with transparent. is_transparent = true; } - ReprAttr::ReprInt(int_type) => { - if let Some(last_int_type) = maybe_last_int_type - && last_int_type == int_type - { - // We'll "miss" detecting repeated int reprs if the user specifies - // #[repr(u8, u64, u8)] for example. But that's okay because we've got - // conflicting reprs anyway so it's not worth the effort to do more precise - // tracking. - repeated_repr = true; - } - maybe_last_int_type = Some(int_type); + ReprAttr::ReprInt(..) => { int_reprs += 1; } }; } + if !reprs.is_empty() { + let sorted_reprs = { + let mut to_sort = reprs.to_owned(); + to_sort.sort_unstable(); + to_sort + }; + + // To collect all duplicates, get subslices where all of the elements of the subslice + // are equal, then filter out all those whose length is not 1. We could return warnings + // for each of them, but that's annoyingly excessive. So we instead collect all spans in + // one big Vec. + let spans: Vec = sorted_reprs + .chunk_by(|(a, _), (b, _)| a == b) + .map(ToOwned::to_owned) + .filter(|slice| slice.len() != 1) + .flatten() + .map(|(_, span)| span) + .collect(); + + if !spans.is_empty() { + self.tcx.emit_node_span_lint( + REPEATED_REPRS, + hir_id, + spans, + diagnostics::RepeatedRepr, + ); + } + } + // Just point at all repr hints if there are any incompatibilities. // This is not ideal, but tracking precisely which ones are at fault is a huge hassle. let hint_spans = reprs.iter().map(|(_, span)| *span); @@ -1306,17 +1300,8 @@ impl<'tcx> CheckAttrVisitor<'tcx> { self.tcx.emit_node_span_lint( CONFLICTING_REPR_HINTS, hir_id, - hint_spans.clone().collect::>(), - diagnostics::ReprConflictingLint, - ); - } - - if repeated_repr { - self.tcx.emit_node_span_lint( - REPEATED_REPRS, - hir_id, hint_spans.collect::>(), - diagnostics::RepeatedRepr, + diagnostics::ReprConflictingLint, ); } } diff --git a/compiler/rustc_passes/src/diagnostics.rs b/compiler/rustc_passes/src/diagnostics.rs index 2f4900a6b47a7..c343d9c7078e7 100644 --- a/compiler/rustc_passes/src/diagnostics.rs +++ b/compiler/rustc_passes/src/diagnostics.rs @@ -608,7 +608,7 @@ pub(crate) struct TransparentIncompatible { } #[derive(Diagnostic)] -#[diag("representation attribute is specified more than once")] +#[diag("`#[repr(..)]` attribute is specified more than once")] #[note("for consistency, only specify the representation once")] pub(crate) struct RepeatedRepr; diff --git a/tests/ui/attributes/issue-100631.rs b/tests/ui/attributes/issue-100631.rs index d496231c73026..9a30691a39ec3 100644 --- a/tests/ui/attributes/issue-100631.rs +++ b/tests/ui/attributes/issue-100631.rs @@ -2,7 +2,7 @@ // can reasonably deal with multiple attributes. // `repr` will use `TyCtxt::get_attrs` since it's `DuplicatesOk`. #[repr(C)] //~ ERROR: unsupported representation for zero-variant enum [E0084] -//~^ WARN representation attribute is specified more than once +//~^ WARN `#[repr(..)]` attribute is specified more than once [repeated_reprs] #[repr(C)] enum Foo {} diff --git a/tests/ui/attributes/issue-100631.stderr b/tests/ui/attributes/issue-100631.stderr index 66e08738eb02c..0ecc19ae85b3d 100644 --- a/tests/ui/attributes/issue-100631.stderr +++ b/tests/ui/attributes/issue-100631.stderr @@ -1,4 +1,4 @@ -warning: representation attribute is specified more than once +warning: `#[repr(..)]` attribute is specified more than once --> $DIR/issue-100631.rs:4:8 | LL | #[repr(C)] diff --git a/tests/ui/lint/unused/unused-attr-duplicate.rs b/tests/ui/lint/unused/unused-attr-duplicate.rs index 348c9590e8b27..c013041ed4159 100644 --- a/tests/ui/lint/unused/unused-attr-duplicate.rs +++ b/tests/ui/lint/unused/unused-attr-duplicate.rs @@ -64,7 +64,7 @@ fn t1() {} #[must_use = "some message"] //~^ ERROR unused attribute //~| WARN this was previously accepted -#[repr(C)] //~ WARN representation attribute is specified more than once +#[repr(C)] //~ WARN `#[repr(..)]` attribute is specified more than once [repeated_reprs] #[repr(C)] #[non_exhaustive] #[non_exhaustive] //~ ERROR unused attribute diff --git a/tests/ui/lint/unused/unused-attr-duplicate.stderr b/tests/ui/lint/unused/unused-attr-duplicate.stderr index 93f7a4791188f..6e4f7d23604c2 100644 --- a/tests/ui/lint/unused/unused-attr-duplicate.stderr +++ b/tests/ui/lint/unused/unused-attr-duplicate.stderr @@ -16,7 +16,7 @@ note: the lint level is defined here LL | #![deny(unused_attributes)] | ^^^^^^^^^^^^^^^^^ -warning: representation attribute is specified more than once +warning: `#[repr(..)]` attribute is specified more than once --> $DIR/unused-attr-duplicate.rs:67:8 | LL | #[repr(C)] @@ -264,19 +264,6 @@ note: attribute also specified here LL | #[track_caller] | ^^^^^^^^^^^^^^^ -error: unused attribute - --> $DIR/unused-attr-duplicate.rs:93:5 - | -LL | #[link_name = "rust_dbg_extern_identity_u32"] - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove this attribute - | -note: attribute also specified here - --> $DIR/unused-attr-duplicate.rs:92:5 - | -LL | #[link_name = "this_does_not_exist"] - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! - error: unused attribute --> $DIR/unused-attr-duplicate.rs:99:1 | @@ -328,13 +315,13 @@ LL | #[link_section = "__TEXT,__text"] = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! error: unused attribute - --> $DIR/unused-attr-duplicate.rs:94:5 + --> $DIR/unused-attr-duplicate.rs:93:5 | LL | #[link_name = "rust_dbg_extern_identity_u32"] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove this attribute | note: attribute also specified here - --> $DIR/unused-attr-duplicate.rs:93:5 + --> $DIR/unused-attr-duplicate.rs:92:5 | LL | #[link_name = "this_does_not_exist"] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/tests/ui/repr/conflicting-repr-hints.rs b/tests/ui/repr/conflicting-repr-hints.rs index 032f2b2e6c608..81a94aad78ff6 100644 --- a/tests/ui/repr/conflicting-repr-hints.rs +++ b/tests/ui/repr/conflicting-repr-hints.rs @@ -36,10 +36,10 @@ struct G(i32); //~ ERROR type has conflicting packed and align representation hi #[repr(packed)] struct H(i32); //~ ERROR type has conflicting packed and align representation hints -#[repr(packed, packed(2))] //~ WARN representation attribute is specified more than once +#[repr(packed, packed(2))] struct I(i32); //~ ERROR type has conflicting packed representation hints -#[repr(packed(2))] //~ WARN representation attribute is specified more than once +#[repr(packed(2))] #[repr(packed)] struct J(i32); //~ ERROR type has conflicting packed representation hints diff --git a/tests/ui/repr/conflicting-repr-hints.stderr b/tests/ui/repr/conflicting-repr-hints.stderr index a99546b754785..8f2655fd716f1 100644 --- a/tests/ui/repr/conflicting-repr-hints.stderr +++ b/tests/ui/repr/conflicting-repr-hints.stderr @@ -17,32 +17,14 @@ LL | #[repr(u32, u64)] = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! = note: for more information, see issue #68585 -warning: representation attribute is specified more than once - --> $DIR/conflicting-repr-hints.rs:39:8 - | -LL | #[repr(packed, packed(2))] - | ^^^^^^ ^^^^^^^^^ - | - = note: for consistency, only specify the representation once - = note: `#[warn(repeated_reprs)]` on by default - -warning: representation attribute is specified more than once - --> $DIR/conflicting-repr-hints.rs:42:8 - | -LL | #[repr(packed(2))] - | ^^^^^^^^^ -LL | #[repr(packed)] - | ^^^^^^ - | - = note: for consistency, only specify the representation once - -warning: representation attribute is specified more than once +warning: `#[repr(..)]` attribute is specified more than once --> $DIR/conflicting-repr-hints.rs:46:8 | LL | #[repr(packed, packed(1))] | ^^^^^^ ^^^^^^^^^ | = note: for consistency, only specify the representation once + = note: `#[warn(repeated_reprs)]` on by default error[E0587]: type has conflicting packed and align representation hints --> $DIR/conflicting-repr-hints.rs:29:1 @@ -104,7 +86,7 @@ error[E0587]: type has conflicting packed and align representation hints LL | pub union U { | ^^^^^^^^^^^ -error: aborting due to 12 previous errors; 3 warnings emitted +error: aborting due to 12 previous errors; 1 warning emitted Some errors have detailed explanations: E0566, E0587, E0634. For more information about an error, try `rustc --explain E0566`. diff --git a/tests/ui/repr/repr-repeated-attrs.rs b/tests/ui/repr/repr-repeated-attrs.rs index 61e3ba05625d8..7306b9192f09e 100644 --- a/tests/ui/repr/repr-repeated-attrs.rs +++ b/tests/ui/repr/repr-repeated-attrs.rs @@ -1,32 +1,32 @@ // Tests to ensure we warn on repeated `#[repr(..)]` attributes. -#[repr(transparent, transparent)] +#[repr(transparent, transparent)] //~ WARN `#[repr(..)]` attribute is specified more than once [repeated_reprs] //~^ ERROR transparent struct cannot have other repr hints #[repr(transparent)] struct SeveralTransparentReprs(*mut u8); -#[repr(transparent)] +#[repr(transparent)] //~ WARN `#[repr(..)]` attribute is specified more than once [repeated_reprs] //~^ ERROR transparent struct cannot have other repr hints #[repr(transparent)] struct MultilineOnly(*mut u8); #[repr(Rust, Rust)] -//~^ WARN representation attribute is specified more than once +//~^ WARN `#[repr(..)]` attribute is specified more than once [repeated_reprs] struct SeveralRustReprs(u8); #[repr(C, C)] -//~^ WARN representation attribute is specified more than once +//~^ WARN `#[repr(..)]` attribute is specified more than once [repeated_reprs] #[repr(C, C, C)] struct SeveralC(u8); -#[repr(u8, u8)] //~ WARN representation attribute is specified more than once +#[repr(u8, u8)] //~ WARN `#[repr(..)]` attribute is specified more than once [repeated_reprs] //~^ ERROR conflicting representation hints //~| WARN this was previously accepted enum SeveralPrimitiveRerprs { Variant, } -#[repr(C, C, u8)] //~ WARN representation attribute is specified more than once +#[repr(C, C, u8)] //~ WARN `#[repr(..)]` attribute is specified more than once [repeated_reprs] //~^ ERROR conflicting representation hints //~| WARN this was previously accepted #[repr(C, u8, u8)] @@ -34,7 +34,7 @@ enum SeveralCAndPrims { Variant(u8), } -#[repr(Rust, u8, u8)] //~ WARN representation attribute is specified more than once +#[repr(Rust, u8, u8)] //~ WARN `#[repr(..)]` attribute is specified more than once [repeated_reprs] //~^ ERROR conflicting representation hints //~^^ ERROR conflicting representation hints //~| WARN this was previously accepted @@ -42,7 +42,7 @@ enum RustAndPrimDisallowed { Variant(u8), } -#[repr(u8, u8)] //~ WARN representation attribute is specified more than once +#[repr(u8, u8)] //~ WARN `#[repr(..)]` attribute is specified more than once [repeated_reprs] //~^ ERROR conflicting representation hints //~| WARN this was previously accepted #[repr(u16)] @@ -58,7 +58,7 @@ enum CWithIntsCausesFCW1 { B, } -#[repr(C, C, u8, u8, u8)] //~ WARN representation attribute is specified more than once +#[repr(C, C, u8, u8, u8)] //~ WARN `#[repr(..)]` attribute is specified more than once [repeated_reprs] //~^ ERROR conflicting representation hints //~| WARN this was previously accepted enum CWithIntsCausesFCW2 { diff --git a/tests/ui/repr/repr-repeated-attrs.stderr b/tests/ui/repr/repr-repeated-attrs.stderr index 57af8ec804d76..a0b8b1d7da3cc 100644 --- a/tests/ui/repr/repr-repeated-attrs.stderr +++ b/tests/ui/repr/repr-repeated-attrs.stderr @@ -1,3 +1,15 @@ +warning: `#[repr(..)]` attribute is specified more than once + --> $DIR/repr-repeated-attrs.rs:3:8 + | +LL | #[repr(transparent, transparent)] + | ^^^^^^^^^^^ ^^^^^^^^^^^ +LL | +LL | #[repr(transparent)] + | ^^^^^^^^^^^ + | + = note: for consistency, only specify the representation once + = note: `#[warn(repeated_reprs)]` on by default + error[E0692]: transparent struct cannot have other repr hints --> $DIR/repr-repeated-attrs.rs:3:8 | @@ -7,6 +19,17 @@ LL | LL | #[repr(transparent)] | ^^^^^^^^^^^ +warning: `#[repr(..)]` attribute is specified more than once + --> $DIR/repr-repeated-attrs.rs:8:8 + | +LL | #[repr(transparent)] + | ^^^^^^^^^^^ +LL | +LL | #[repr(transparent)] + | ^^^^^^^^^^^ + | + = note: for consistency, only specify the representation once + error[E0692]: transparent struct cannot have other repr hints --> $DIR/repr-repeated-attrs.rs:8:8 | @@ -16,16 +39,15 @@ LL | LL | #[repr(transparent)] | ^^^^^^^^^^^ -warning: representation attribute is specified more than once +warning: `#[repr(..)]` attribute is specified more than once --> $DIR/repr-repeated-attrs.rs:13:8 | LL | #[repr(Rust, Rust)] | ^^^^ ^^^^ | = note: for consistency, only specify the representation once - = note: `#[warn(repeated_reprs)]` on by default -warning: representation attribute is specified more than once +warning: `#[repr(..)]` attribute is specified more than once --> $DIR/repr-repeated-attrs.rs:17:8 | LL | #[repr(C, C)] @@ -36,25 +58,25 @@ LL | #[repr(C, C, C)] | = note: for consistency, only specify the representation once -error[E0566]: conflicting representation hints +warning: `#[repr(..)]` attribute is specified more than once --> $DIR/repr-repeated-attrs.rs:22:8 | LL | #[repr(u8, u8)] | ^^ ^^ | - = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! - = note: for more information, see issue #68585 - = note: `#[deny(conflicting_repr_hints)]` (part of `#[deny(future_incompatible)]`) on by default + = note: for consistency, only specify the representation once -warning: representation attribute is specified more than once +error[E0566]: conflicting representation hints --> $DIR/repr-repeated-attrs.rs:22:8 | LL | #[repr(u8, u8)] | ^^ ^^ | - = note: for consistency, only specify the representation once + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #68585 + = note: `#[deny(conflicting_repr_hints)]` (part of `#[deny(future_incompatible)]`) on by default -error[E0566]: conflicting representation hints +warning: `#[repr(..)]` attribute is specified more than once --> $DIR/repr-repeated-attrs.rs:29:8 | LL | #[repr(C, C, u8)] @@ -63,10 +85,9 @@ LL | #[repr(C, C, u8)] LL | #[repr(C, u8, u8)] | ^ ^^ ^^ | - = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! - = note: for more information, see issue #68585 + = note: for consistency, only specify the representation once -warning: representation attribute is specified more than once +error[E0566]: conflicting representation hints --> $DIR/repr-repeated-attrs.rs:29:8 | LL | #[repr(C, C, u8)] @@ -75,6 +96,15 @@ LL | #[repr(C, C, u8)] LL | #[repr(C, u8, u8)] | ^ ^^ ^^ | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #68585 + +warning: `#[repr(..)]` attribute is specified more than once + --> $DIR/repr-repeated-attrs.rs:37:14 + | +LL | #[repr(Rust, u8, u8)] + | ^^ ^^ + | = note: for consistency, only specify the representation once error[E0566]: conflicting representation hints @@ -92,11 +122,11 @@ LL | #[repr(Rust, u8, u8)] = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! = note: for more information, see issue #68585 -warning: representation attribute is specified more than once - --> $DIR/repr-repeated-attrs.rs:37:8 +warning: `#[repr(..)]` attribute is specified more than once + --> $DIR/repr-repeated-attrs.rs:45:8 | -LL | #[repr(Rust, u8, u8)] - | ^^^^ ^^ ^^ +LL | #[repr(u8, u8)] + | ^^ ^^ | = note: for consistency, only specify the representation once @@ -112,17 +142,6 @@ LL | #[repr(u16)] = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! = note: for more information, see issue #68585 -warning: representation attribute is specified more than once - --> $DIR/repr-repeated-attrs.rs:45:8 - | -LL | #[repr(u8, u8)] - | ^^ ^^ -... -LL | #[repr(u16)] - | ^^^ - | - = note: for consistency, only specify the representation once - error[E0566]: conflicting representation hints --> $DIR/repr-repeated-attrs.rs:53:8 | @@ -132,24 +151,24 @@ LL | #[repr(C, u8)] = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! = note: for more information, see issue #68585 -error[E0566]: conflicting representation hints +warning: `#[repr(..)]` attribute is specified more than once --> $DIR/repr-repeated-attrs.rs:61:8 | LL | #[repr(C, C, u8, u8, u8)] | ^ ^ ^^ ^^ ^^ | - = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! - = note: for more information, see issue #68585 + = note: for consistency, only specify the representation once -warning: representation attribute is specified more than once +error[E0566]: conflicting representation hints --> $DIR/repr-repeated-attrs.rs:61:8 | LL | #[repr(C, C, u8, u8, u8)] | ^ ^ ^^ ^^ ^^ | - = note: for consistency, only specify the representation once + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #68585 -error: aborting due to 9 previous errors; 7 warnings emitted +error: aborting due to 9 previous errors; 9 warnings emitted Some errors have detailed explanations: E0566, E0692. For more information about an error, try `rustc --explain E0566`. diff --git a/tests/ui/structs-enums/align-enum.rs b/tests/ui/structs-enums/align-enum.rs index a635af7352afe..ff80a19211cda 100644 --- a/tests/ui/structs-enums/align-enum.rs +++ b/tests/ui/structs-enums/align-enum.rs @@ -11,7 +11,7 @@ enum Align16 { } // Raise alignment by maximum -#[repr(align(1), align(16))] //~ WARN representation attribute is specified more than once +#[repr(align(1), align(16))] #[repr(align(32))] #[repr(align(4))] enum Align32 { diff --git a/tests/ui/structs-enums/align-enum.stderr b/tests/ui/structs-enums/align-enum.stderr deleted file mode 100644 index 9b8c9842f81df..0000000000000 --- a/tests/ui/structs-enums/align-enum.stderr +++ /dev/null @@ -1,15 +0,0 @@ -warning: representation attribute is specified more than once - --> $DIR/align-enum.rs:14:8 - | -LL | #[repr(align(1), align(16))] - | ^^^^^^^^ ^^^^^^^^^ -LL | #[repr(align(32))] - | ^^^^^^^^^ -LL | #[repr(align(4))] - | ^^^^^^^^ - | - = note: for consistency, only specify the representation once - = note: `#[warn(repeated_reprs)]` on by default - -warning: 1 warning emitted - diff --git a/tests/ui/structs-enums/align-struct.rs b/tests/ui/structs-enums/align-struct.rs index 2d1ebf6731a62..3d8dad6e324e3 100644 --- a/tests/ui/structs-enums/align-struct.rs +++ b/tests/ui/structs-enums/align-struct.rs @@ -13,7 +13,7 @@ struct Align16(i32); struct Align1(i32); // Multiple attributes take the max -#[repr(align(4))] //~ WARN representation attribute is specified more than once +#[repr(align(4))] #[repr(align(16))] #[repr(align(8))] struct AlignMany(i32); diff --git a/tests/ui/structs-enums/align-struct.stderr b/tests/ui/structs-enums/align-struct.stderr deleted file mode 100644 index f54e9cd14cd8b..0000000000000 --- a/tests/ui/structs-enums/align-struct.stderr +++ /dev/null @@ -1,15 +0,0 @@ -warning: representation attribute is specified more than once - --> $DIR/align-struct.rs:16:8 - | -LL | #[repr(align(4))] - | ^^^^^^^^ -LL | #[repr(align(16))] - | ^^^^^^^^^ -LL | #[repr(align(8))] - | ^^^^^^^^ - | - = note: for consistency, only specify the representation once - = note: `#[warn(repeated_reprs)]` on by default - -warning: 1 warning emitted - From e99f23fec0b37494a9361b02fe509997896c5e37 Mon Sep 17 00:00:00 2001 From: Charlotte Ausel Date: Mon, 24 Aug 2026 13:07:15 +0100 Subject: [PATCH 7/7] add to unused group --- compiler/rustc_lint/src/lib.rs | 3 +- compiler/rustc_lint_defs/src/builtin.rs | 1 + tests/ui/attributes/issue-100631.rs | 1 + tests/ui/attributes/issue-100631.stderr | 6 +-- ...-dont-override-forbid-in-same-scope.stderr | 18 +++++++ tests/ui/lint/outer-forbid.stderr | 18 +++++++ tests/ui/lint/unused/unused-attr-duplicate.rs | 2 +- .../lint/unused/unused-attr-duplicate.stderr | 2 +- tests/ui/repr/conflicting-repr-hints.rs | 1 + tests/ui/repr/conflicting-repr-hints.stderr | 32 ++++++------ tests/ui/repr/repr-repeated-attrs.rs | 1 + tests/ui/repr/repr-repeated-attrs.stderr | 50 +++++++++---------- 12 files changed, 88 insertions(+), 47 deletions(-) diff --git a/compiler/rustc_lint/src/lib.rs b/compiler/rustc_lint/src/lib.rs index 852f1cfda5168..1a392ae1c05da 100644 --- a/compiler/rustc_lint/src/lib.rs +++ b/compiler/rustc_lint/src/lib.rs @@ -367,7 +367,8 @@ fn register_builtins(store: &mut LintStore) { UNUSED_PARENS, UNUSED_BRACES, REDUNDANT_SEMICOLONS, - MAP_UNIT_FN + MAP_UNIT_FN, + REPEATED_REPRS ); add_lint_group!("let_underscore", LET_UNDERSCORE_DROP, LET_UNDERSCORE_LOCK); diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs index 11cdbea3c426a..af5db6117f7b5 100644 --- a/compiler/rustc_lint_defs/src/builtin.rs +++ b/compiler/rustc_lint_defs/src/builtin.rs @@ -95,6 +95,7 @@ pub mod hardwired { REFINING_IMPL_TRAIT_INTERNAL, REFINING_IMPL_TRAIT_REACHABLE, RENAMED_AND_REMOVED_LINTS, + REPEATED_REPRS, REPR_C_ENUMS_LARGER_THAN_INT, RESOLVING_TO_ITEMS_SHADOWING_SUPERTRAIT_ITEMS, RTSAN_NONBLOCKING_ASYNC, diff --git a/tests/ui/attributes/issue-100631.rs b/tests/ui/attributes/issue-100631.rs index 9a30691a39ec3..09b34ebfe7a2c 100644 --- a/tests/ui/attributes/issue-100631.rs +++ b/tests/ui/attributes/issue-100631.rs @@ -1,3 +1,4 @@ +//@ compile-flags: -W repeated-reprs // issue #100631, make sure `TyCtxt::get_attr` only called by case that compiler // can reasonably deal with multiple attributes. // `repr` will use `TyCtxt::get_attrs` since it's `DuplicatesOk`. diff --git a/tests/ui/attributes/issue-100631.stderr b/tests/ui/attributes/issue-100631.stderr index 0ecc19ae85b3d..62d82c9b31335 100644 --- a/tests/ui/attributes/issue-100631.stderr +++ b/tests/ui/attributes/issue-100631.stderr @@ -1,5 +1,5 @@ warning: `#[repr(..)]` attribute is specified more than once - --> $DIR/issue-100631.rs:4:8 + --> $DIR/issue-100631.rs:5:8 | LL | #[repr(C)] | ^ @@ -8,10 +8,10 @@ LL | #[repr(C)] | ^ | = note: for consistency, only specify the representation once - = note: `#[warn(repeated_reprs)]` on by default + = note: requested on the command line with `-W repeated-reprs` error[E0084]: unsupported representation for zero-variant enum - --> $DIR/issue-100631.rs:4:8 + --> $DIR/issue-100631.rs:5:8 | LL | #[repr(C)] | ^ diff --git a/tests/ui/lint/issue-70819-dont-override-forbid-in-same-scope.stderr b/tests/ui/lint/issue-70819-dont-override-forbid-in-same-scope.stderr index f40fb73acbb8b..b0eb5636d0479 100644 --- a/tests/ui/lint/issue-70819-dont-override-forbid-in-same-scope.stderr +++ b/tests/ui/lint/issue-70819-dont-override-forbid-in-same-scope.stderr @@ -449,3 +449,21 @@ note: the lint level is defined here LL | #![forbid(forbidden_lint_groups)] | ^^^^^^^^^^^^^^^^^^^^^ +Future breakage diagnostic: +error: warn(unused) incompatible with previous forbid + --> $DIR/issue-70819-dont-override-forbid-in-same-scope.rs:22:13 + | +LL | #![forbid(unused)] + | ------ `forbid` level set here +LL | #![deny(unused)] +LL | #![warn(unused)] + | ^^^^^^ overruled by previous forbid + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #81670 +note: the lint level is defined here + --> $DIR/issue-70819-dont-override-forbid-in-same-scope.rs:17:11 + | +LL | #![forbid(forbidden_lint_groups)] + | ^^^^^^^^^^^^^^^^^^^^^ + diff --git a/tests/ui/lint/outer-forbid.stderr b/tests/ui/lint/outer-forbid.stderr index abe5959176d4a..b2d7ad6c2aabc 100644 --- a/tests/ui/lint/outer-forbid.stderr +++ b/tests/ui/lint/outer-forbid.stderr @@ -489,3 +489,21 @@ note: the lint level is defined here LL | #![forbid(forbidden_lint_groups)] | ^^^^^^^^^^^^^^^^^^^^^ +Future breakage diagnostic: +error: allow(unused) incompatible with previous forbid + --> $DIR/outer-forbid.rs:25:9 + | +LL | #![forbid(unused, non_snake_case)] + | ------ `forbid` level set here +... +LL | #[allow(unused)] + | ^^^^^^ overruled by previous forbid + | + = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! + = note: for more information, see issue #81670 +note: the lint level is defined here + --> $DIR/outer-forbid.rs:18:11 + | +LL | #![forbid(forbidden_lint_groups)] + | ^^^^^^^^^^^^^^^^^^^^^ + diff --git a/tests/ui/lint/unused/unused-attr-duplicate.rs b/tests/ui/lint/unused/unused-attr-duplicate.rs index c013041ed4159..c62fc6036f60f 100644 --- a/tests/ui/lint/unused/unused-attr-duplicate.rs +++ b/tests/ui/lint/unused/unused-attr-duplicate.rs @@ -1,6 +1,6 @@ // Tests for repeating attribute warnings. //@ aux-build:lint_unused_extern_crate.rs -//@ compile-flags:--test +//@ compile-flags:--test -W repeated-reprs // Not tested due to extra requirements: // - panic_handler: needs extra setup // - target_feature: platform-specific diff --git a/tests/ui/lint/unused/unused-attr-duplicate.stderr b/tests/ui/lint/unused/unused-attr-duplicate.stderr index 6e4f7d23604c2..feb1a79bf9b92 100644 --- a/tests/ui/lint/unused/unused-attr-duplicate.stderr +++ b/tests/ui/lint/unused/unused-attr-duplicate.stderr @@ -25,7 +25,7 @@ LL | #[repr(C)] | ^ | = note: for consistency, only specify the representation once - = note: `#[warn(repeated_reprs)]` on by default + = note: requested on the command line with `-W repeated-reprs` error: unused attribute --> $DIR/unused-attr-duplicate.rs:14:1 diff --git a/tests/ui/repr/conflicting-repr-hints.rs b/tests/ui/repr/conflicting-repr-hints.rs index 81a94aad78ff6..6a265e13ad93d 100644 --- a/tests/ui/repr/conflicting-repr-hints.rs +++ b/tests/ui/repr/conflicting-repr-hints.rs @@ -1,3 +1,4 @@ +//@ compile-flags: -W repeated-reprs #![allow(dead_code)] #[repr(C)] diff --git a/tests/ui/repr/conflicting-repr-hints.stderr b/tests/ui/repr/conflicting-repr-hints.stderr index 8f2655fd716f1..2a81610e85f99 100644 --- a/tests/ui/repr/conflicting-repr-hints.stderr +++ b/tests/ui/repr/conflicting-repr-hints.stderr @@ -1,5 +1,5 @@ error[E0566]: conflicting representation hints - --> $DIR/conflicting-repr-hints.rs:13:8 + --> $DIR/conflicting-repr-hints.rs:14:8 | LL | #[repr(C, u64)] | ^ ^^^ @@ -9,7 +9,7 @@ LL | #[repr(C, u64)] = note: `#[deny(conflicting_repr_hints)]` (part of `#[deny(future_incompatible)]`) on by default error[E0566]: conflicting representation hints - --> $DIR/conflicting-repr-hints.rs:19:8 + --> $DIR/conflicting-repr-hints.rs:20:8 | LL | #[repr(u32, u64)] | ^^^ ^^^ @@ -18,70 +18,70 @@ LL | #[repr(u32, u64)] = note: for more information, see issue #68585 warning: `#[repr(..)]` attribute is specified more than once - --> $DIR/conflicting-repr-hints.rs:46:8 + --> $DIR/conflicting-repr-hints.rs:47:8 | LL | #[repr(packed, packed(1))] | ^^^^^^ ^^^^^^^^^ | = note: for consistency, only specify the representation once - = note: `#[warn(repeated_reprs)]` on by default + = note: requested on the command line with `-W repeated-reprs` error[E0587]: type has conflicting packed and align representation hints - --> $DIR/conflicting-repr-hints.rs:29:1 + --> $DIR/conflicting-repr-hints.rs:30:1 | LL | struct F(i32); | ^^^^^^^^ error[E0587]: type has conflicting packed and align representation hints - --> $DIR/conflicting-repr-hints.rs:33:1 + --> $DIR/conflicting-repr-hints.rs:34:1 | LL | struct G(i32); | ^^^^^^^^ error[E0587]: type has conflicting packed and align representation hints - --> $DIR/conflicting-repr-hints.rs:37:1 + --> $DIR/conflicting-repr-hints.rs:38:1 | LL | struct H(i32); | ^^^^^^^^ error[E0634]: type has conflicting packed representation hints - --> $DIR/conflicting-repr-hints.rs:40:1 + --> $DIR/conflicting-repr-hints.rs:41:1 | LL | struct I(i32); | ^^^^^^^^ error[E0634]: type has conflicting packed representation hints - --> $DIR/conflicting-repr-hints.rs:44:1 + --> $DIR/conflicting-repr-hints.rs:45:1 | LL | struct J(i32); | ^^^^^^^^ error[E0587]: type has conflicting packed and align representation hints - --> $DIR/conflicting-repr-hints.rs:50:1 + --> $DIR/conflicting-repr-hints.rs:51:1 | LL | union X { | ^^^^^^^ error[E0587]: type has conflicting packed and align representation hints - --> $DIR/conflicting-repr-hints.rs:57:1 + --> $DIR/conflicting-repr-hints.rs:58:1 | LL | union Y { | ^^^^^^^ error[E0587]: type has conflicting packed and align representation hints - --> $DIR/conflicting-repr-hints.rs:64:1 + --> $DIR/conflicting-repr-hints.rs:65:1 | LL | union Z { | ^^^^^^^ error[E0587]: type has conflicting packed and align representation hints - --> $DIR/conflicting-repr-hints.rs:70:1 + --> $DIR/conflicting-repr-hints.rs:71:1 | LL | pub struct S(u16); | ^^^^^^^^^^^^ error[E0587]: type has conflicting packed and align representation hints - --> $DIR/conflicting-repr-hints.rs:73:1 + --> $DIR/conflicting-repr-hints.rs:74:1 | LL | pub union U { | ^^^^^^^^^^^ @@ -92,7 +92,7 @@ Some errors have detailed explanations: E0566, E0587, E0634. For more information about an error, try `rustc --explain E0566`. Future incompatibility report: Future breakage diagnostic: error[E0566]: conflicting representation hints - --> $DIR/conflicting-repr-hints.rs:13:8 + --> $DIR/conflicting-repr-hints.rs:14:8 | LL | #[repr(C, u64)] | ^ ^^^ @@ -103,7 +103,7 @@ LL | #[repr(C, u64)] Future breakage diagnostic: error[E0566]: conflicting representation hints - --> $DIR/conflicting-repr-hints.rs:19:8 + --> $DIR/conflicting-repr-hints.rs:20:8 | LL | #[repr(u32, u64)] | ^^^ ^^^ diff --git a/tests/ui/repr/repr-repeated-attrs.rs b/tests/ui/repr/repr-repeated-attrs.rs index 7306b9192f09e..122eb9b7485ef 100644 --- a/tests/ui/repr/repr-repeated-attrs.rs +++ b/tests/ui/repr/repr-repeated-attrs.rs @@ -1,4 +1,5 @@ // Tests to ensure we warn on repeated `#[repr(..)]` attributes. +//@ compile-flags: -W repeated-reprs #[repr(transparent, transparent)] //~ WARN `#[repr(..)]` attribute is specified more than once [repeated_reprs] //~^ ERROR transparent struct cannot have other repr hints diff --git a/tests/ui/repr/repr-repeated-attrs.stderr b/tests/ui/repr/repr-repeated-attrs.stderr index a0b8b1d7da3cc..a1e54f6218889 100644 --- a/tests/ui/repr/repr-repeated-attrs.stderr +++ b/tests/ui/repr/repr-repeated-attrs.stderr @@ -1,5 +1,5 @@ warning: `#[repr(..)]` attribute is specified more than once - --> $DIR/repr-repeated-attrs.rs:3:8 + --> $DIR/repr-repeated-attrs.rs:4:8 | LL | #[repr(transparent, transparent)] | ^^^^^^^^^^^ ^^^^^^^^^^^ @@ -8,10 +8,10 @@ LL | #[repr(transparent)] | ^^^^^^^^^^^ | = note: for consistency, only specify the representation once - = note: `#[warn(repeated_reprs)]` on by default + = note: requested on the command line with `-W repeated-reprs` error[E0692]: transparent struct cannot have other repr hints - --> $DIR/repr-repeated-attrs.rs:3:8 + --> $DIR/repr-repeated-attrs.rs:4:8 | LL | #[repr(transparent, transparent)] | ^^^^^^^^^^^ ^^^^^^^^^^^ @@ -20,7 +20,7 @@ LL | #[repr(transparent)] | ^^^^^^^^^^^ warning: `#[repr(..)]` attribute is specified more than once - --> $DIR/repr-repeated-attrs.rs:8:8 + --> $DIR/repr-repeated-attrs.rs:9:8 | LL | #[repr(transparent)] | ^^^^^^^^^^^ @@ -31,7 +31,7 @@ LL | #[repr(transparent)] = note: for consistency, only specify the representation once error[E0692]: transparent struct cannot have other repr hints - --> $DIR/repr-repeated-attrs.rs:8:8 + --> $DIR/repr-repeated-attrs.rs:9:8 | LL | #[repr(transparent)] | ^^^^^^^^^^^ @@ -40,7 +40,7 @@ LL | #[repr(transparent)] | ^^^^^^^^^^^ warning: `#[repr(..)]` attribute is specified more than once - --> $DIR/repr-repeated-attrs.rs:13:8 + --> $DIR/repr-repeated-attrs.rs:14:8 | LL | #[repr(Rust, Rust)] | ^^^^ ^^^^ @@ -48,7 +48,7 @@ LL | #[repr(Rust, Rust)] = note: for consistency, only specify the representation once warning: `#[repr(..)]` attribute is specified more than once - --> $DIR/repr-repeated-attrs.rs:17:8 + --> $DIR/repr-repeated-attrs.rs:18:8 | LL | #[repr(C, C)] | ^ ^ @@ -59,7 +59,7 @@ LL | #[repr(C, C, C)] = note: for consistency, only specify the representation once warning: `#[repr(..)]` attribute is specified more than once - --> $DIR/repr-repeated-attrs.rs:22:8 + --> $DIR/repr-repeated-attrs.rs:23:8 | LL | #[repr(u8, u8)] | ^^ ^^ @@ -67,7 +67,7 @@ LL | #[repr(u8, u8)] = note: for consistency, only specify the representation once error[E0566]: conflicting representation hints - --> $DIR/repr-repeated-attrs.rs:22:8 + --> $DIR/repr-repeated-attrs.rs:23:8 | LL | #[repr(u8, u8)] | ^^ ^^ @@ -77,7 +77,7 @@ LL | #[repr(u8, u8)] = note: `#[deny(conflicting_repr_hints)]` (part of `#[deny(future_incompatible)]`) on by default warning: `#[repr(..)]` attribute is specified more than once - --> $DIR/repr-repeated-attrs.rs:29:8 + --> $DIR/repr-repeated-attrs.rs:30:8 | LL | #[repr(C, C, u8)] | ^ ^ ^^ @@ -88,7 +88,7 @@ LL | #[repr(C, u8, u8)] = note: for consistency, only specify the representation once error[E0566]: conflicting representation hints - --> $DIR/repr-repeated-attrs.rs:29:8 + --> $DIR/repr-repeated-attrs.rs:30:8 | LL | #[repr(C, C, u8)] | ^ ^ ^^ @@ -100,7 +100,7 @@ LL | #[repr(C, u8, u8)] = note: for more information, see issue #68585 warning: `#[repr(..)]` attribute is specified more than once - --> $DIR/repr-repeated-attrs.rs:37:14 + --> $DIR/repr-repeated-attrs.rs:38:14 | LL | #[repr(Rust, u8, u8)] | ^^ ^^ @@ -108,13 +108,13 @@ LL | #[repr(Rust, u8, u8)] = note: for consistency, only specify the representation once error[E0566]: conflicting representation hints - --> $DIR/repr-repeated-attrs.rs:37:8 + --> $DIR/repr-repeated-attrs.rs:38:8 | LL | #[repr(Rust, u8, u8)] | ^^^^ ^^ ^^ error[E0566]: conflicting representation hints - --> $DIR/repr-repeated-attrs.rs:37:8 + --> $DIR/repr-repeated-attrs.rs:38:8 | LL | #[repr(Rust, u8, u8)] | ^^^^ ^^ ^^ @@ -123,7 +123,7 @@ LL | #[repr(Rust, u8, u8)] = note: for more information, see issue #68585 warning: `#[repr(..)]` attribute is specified more than once - --> $DIR/repr-repeated-attrs.rs:45:8 + --> $DIR/repr-repeated-attrs.rs:46:8 | LL | #[repr(u8, u8)] | ^^ ^^ @@ -131,7 +131,7 @@ LL | #[repr(u8, u8)] = note: for consistency, only specify the representation once error[E0566]: conflicting representation hints - --> $DIR/repr-repeated-attrs.rs:45:8 + --> $DIR/repr-repeated-attrs.rs:46:8 | LL | #[repr(u8, u8)] | ^^ ^^ @@ -143,7 +143,7 @@ LL | #[repr(u16)] = note: for more information, see issue #68585 error[E0566]: conflicting representation hints - --> $DIR/repr-repeated-attrs.rs:53:8 + --> $DIR/repr-repeated-attrs.rs:54:8 | LL | #[repr(C, u8)] | ^ ^^ @@ -152,7 +152,7 @@ LL | #[repr(C, u8)] = note: for more information, see issue #68585 warning: `#[repr(..)]` attribute is specified more than once - --> $DIR/repr-repeated-attrs.rs:61:8 + --> $DIR/repr-repeated-attrs.rs:62:8 | LL | #[repr(C, C, u8, u8, u8)] | ^ ^ ^^ ^^ ^^ @@ -160,7 +160,7 @@ LL | #[repr(C, C, u8, u8, u8)] = note: for consistency, only specify the representation once error[E0566]: conflicting representation hints - --> $DIR/repr-repeated-attrs.rs:61:8 + --> $DIR/repr-repeated-attrs.rs:62:8 | LL | #[repr(C, C, u8, u8, u8)] | ^ ^ ^^ ^^ ^^ @@ -174,7 +174,7 @@ Some errors have detailed explanations: E0566, E0692. For more information about an error, try `rustc --explain E0566`. Future incompatibility report: Future breakage diagnostic: error[E0566]: conflicting representation hints - --> $DIR/repr-repeated-attrs.rs:22:8 + --> $DIR/repr-repeated-attrs.rs:23:8 | LL | #[repr(u8, u8)] | ^^ ^^ @@ -185,7 +185,7 @@ LL | #[repr(u8, u8)] Future breakage diagnostic: error[E0566]: conflicting representation hints - --> $DIR/repr-repeated-attrs.rs:29:8 + --> $DIR/repr-repeated-attrs.rs:30:8 | LL | #[repr(C, C, u8)] | ^ ^ ^^ @@ -199,7 +199,7 @@ LL | #[repr(C, u8, u8)] Future breakage diagnostic: error[E0566]: conflicting representation hints - --> $DIR/repr-repeated-attrs.rs:37:8 + --> $DIR/repr-repeated-attrs.rs:38:8 | LL | #[repr(Rust, u8, u8)] | ^^^^ ^^ ^^ @@ -210,7 +210,7 @@ LL | #[repr(Rust, u8, u8)] Future breakage diagnostic: error[E0566]: conflicting representation hints - --> $DIR/repr-repeated-attrs.rs:45:8 + --> $DIR/repr-repeated-attrs.rs:46:8 | LL | #[repr(u8, u8)] | ^^ ^^ @@ -224,7 +224,7 @@ LL | #[repr(u16)] Future breakage diagnostic: error[E0566]: conflicting representation hints - --> $DIR/repr-repeated-attrs.rs:53:8 + --> $DIR/repr-repeated-attrs.rs:54:8 | LL | #[repr(C, u8)] | ^ ^^ @@ -235,7 +235,7 @@ LL | #[repr(C, u8)] Future breakage diagnostic: error[E0566]: conflicting representation hints - --> $DIR/repr-repeated-attrs.rs:61:8 + --> $DIR/repr-repeated-attrs.rs:62:8 | LL | #[repr(C, C, u8, u8, u8)] | ^ ^ ^^ ^^ ^^