From 0ebd56ebbbf3e392c4fc81865ce89fc6f765a885 Mon Sep 17 00:00:00 2001 From: Oli Scherer Date: Thu, 4 Dec 2025 11:49:56 +0000 Subject: [PATCH 1/3] Remove accidental const stability marker on a struct --- library/core/src/array/drain.rs | 1 - 1 file changed, 1 deletion(-) diff --git a/library/core/src/array/drain.rs b/library/core/src/array/drain.rs index 1c6137191324..17792dca583d 100644 --- a/library/core/src/array/drain.rs +++ b/library/core/src/array/drain.rs @@ -31,7 +31,6 @@ impl<'l, 'f, T, U, const N: usize, F: FnMut(T) -> U> Drain<'l, 'f, T, N, F> { } /// See [`Drain::new`]; this is our fake iterator. -#[rustc_const_unstable(feature = "array_try_map", issue = "79711")] #[unstable(feature = "array_try_map", issue = "79711")] pub(super) struct Drain<'l, 'f, T, const N: usize, F> { // FIXME(const-hack): This is essentially a slice::IterMut<'static>, replace when possible. From 628c37afadaea6702f95fef3b086e99980afb7ce Mon Sep 17 00:00:00 2001 From: Oli Scherer Date: Thu, 4 Dec 2025 08:55:33 +0000 Subject: [PATCH 2/3] Restrict the set of things that const stability can be applied --- .../src/attributes/stability.rs | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/compiler/rustc_attr_parsing/src/attributes/stability.rs b/compiler/rustc_attr_parsing/src/attributes/stability.rs index 1f01cadcb43e..fb204e77abc8 100644 --- a/compiler/rustc_attr_parsing/src/attributes/stability.rs +++ b/compiler/rustc_attr_parsing/src/attributes/stability.rs @@ -244,7 +244,21 @@ impl AttributeParser for ConstStabilityParser { this.promotable = true; }), ]; - const ALLOWED_TARGETS: AllowedTargets = ALLOWED_TARGETS; + const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowList(&[ + Allow(Target::Fn), + Allow(Target::Method(MethodKind::Inherent)), + Allow(Target::Method(MethodKind::TraitImpl)), + Allow(Target::Method(MethodKind::Trait { body: true })), + Allow(Target::Impl { of_trait: false }), + Allow(Target::Impl { of_trait: true }), + Allow(Target::Use), // FIXME I don't think this does anything? + Allow(Target::Const), + Allow(Target::AssocConst), + Allow(Target::Trait), + Allow(Target::Static), + Allow(Target::Crate), + Allow(Target::MacroDef), // FIXME(oli-obk): remove this and eliminate the manual check for it + ]); fn finalize(mut self, cx: &FinalizeContext<'_, '_, S>) -> Option { if self.promotable { From 475b9d9819a092e1820a07c688fdc7cd7b26c6aa Mon Sep 17 00:00:00 2001 From: Oli Scherer Date: Tue, 10 Feb 2026 09:37:30 +0000 Subject: [PATCH 3/3] Prevent const stability attrs from being applied to macros via the normal attribute logic instead of special cased checks --- .../src/attributes/stability.rs | 1 - compiler/rustc_expand/src/base.rs | 9 --------- compiler/rustc_expand/src/errors.rs | 10 ---------- .../ui/attributes/const-stability-on-macro.rs | 6 +++--- .../const-stability-on-macro.stderr | 20 +++++++++---------- 5 files changed, 12 insertions(+), 34 deletions(-) diff --git a/compiler/rustc_attr_parsing/src/attributes/stability.rs b/compiler/rustc_attr_parsing/src/attributes/stability.rs index fb204e77abc8..a2be2d42b3e1 100644 --- a/compiler/rustc_attr_parsing/src/attributes/stability.rs +++ b/compiler/rustc_attr_parsing/src/attributes/stability.rs @@ -257,7 +257,6 @@ impl AttributeParser for ConstStabilityParser { Allow(Target::Trait), Allow(Target::Static), Allow(Target::Crate), - Allow(Target::MacroDef), // FIXME(oli-obk): remove this and eliminate the manual check for it ]); fn finalize(mut self, cx: &FinalizeContext<'_, '_, S>) -> Option { diff --git a/compiler/rustc_expand/src/base.rs b/compiler/rustc_expand/src/base.rs index 6b3c7fe97932..91f98d475f00 100644 --- a/compiler/rustc_expand/src/base.rs +++ b/compiler/rustc_expand/src/base.rs @@ -962,15 +962,6 @@ impl SyntaxExtension { let stability = find_attr!(attrs, AttributeKind::Stability { stability, .. } => *stability); - // FIXME(jdonszelmann): make it impossible to miss the or_else in the typesystem - if let Some(sp) = - find_attr!(attrs, AttributeKind::RustcConstStability { span, .. } => *span) - { - sess.dcx().emit_err(errors::MacroConstStability { - span: sp, - head_span: sess.source_map().guess_head_span(span), - }); - } if let Some(sp) = find_attr!(attrs, AttributeKind::RustcBodyStability{ span, .. } => *span) { sess.dcx().emit_err(errors::MacroBodyStability { diff --git a/compiler/rustc_expand/src/errors.rs b/compiler/rustc_expand/src/errors.rs index e64bfc136d16..b6fcc13321ee 100644 --- a/compiler/rustc_expand/src/errors.rs +++ b/compiler/rustc_expand/src/errors.rs @@ -80,16 +80,6 @@ pub(crate) struct ResolveRelativePath { pub path: String, } -#[derive(Diagnostic)] -#[diag("macros cannot have const stability attributes")] -pub(crate) struct MacroConstStability { - #[primary_span] - #[label("invalid const stability attribute")] - pub span: Span, - #[label("const stability attribute affects this macro")] - pub head_span: Span, -} - #[derive(Diagnostic)] #[diag("macros cannot have body stability attributes")] pub(crate) struct MacroBodyStability { diff --git a/tests/ui/attributes/const-stability-on-macro.rs b/tests/ui/attributes/const-stability-on-macro.rs index af268ccd5366..4336370430d4 100644 --- a/tests/ui/attributes/const-stability-on-macro.rs +++ b/tests/ui/attributes/const-stability-on-macro.rs @@ -2,13 +2,13 @@ #![stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "foo", since = "3.3.3")] -//~^ ERROR macros cannot have const stability attributes +//~^ ERROR attribute cannot be used on macro defs macro_rules! foo { () => {}; } -#[rustc_const_unstable(feature = "bar", issue="none")] -//~^ ERROR macros cannot have const stability attributes +#[rustc_const_unstable(feature = "bar", issue = "none")] +//~^ ERROR attribute cannot be used on macro defs macro_rules! bar { () => {}; } diff --git a/tests/ui/attributes/const-stability-on-macro.stderr b/tests/ui/attributes/const-stability-on-macro.stderr index 28f31e3d4f61..a8b56edfa59d 100644 --- a/tests/ui/attributes/const-stability-on-macro.stderr +++ b/tests/ui/attributes/const-stability-on-macro.stderr @@ -1,20 +1,18 @@ -error: macros cannot have const stability attributes +error: `#[rustc_const_stable]` attribute cannot be used on macro defs --> $DIR/const-stability-on-macro.rs:4:1 | LL | #[rustc_const_stable(feature = "foo", since = "3.3.3")] - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ invalid const stability attribute -LL | -LL | macro_rules! foo { - | ---------------- const stability attribute affects this macro + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = help: `#[rustc_const_stable]` can be applied to associated consts, constants, crates, functions, impl blocks, statics, traits, and use statements -error: macros cannot have const stability attributes +error: `#[rustc_const_unstable]` attribute cannot be used on macro defs --> $DIR/const-stability-on-macro.rs:10:1 | -LL | #[rustc_const_unstable(feature = "bar", issue="none")] - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ invalid const stability attribute -LL | -LL | macro_rules! bar { - | ---------------- const stability attribute affects this macro +LL | #[rustc_const_unstable(feature = "bar", issue = "none")] + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = help: `#[rustc_const_unstable]` can be applied to associated consts, constants, crates, functions, impl blocks, statics, traits, and use statements error: aborting due to 2 previous errors