diff --git a/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs b/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs index 29464cf8c4e..b97dd1ae8d5 100644 --- a/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs +++ b/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs @@ -226,7 +226,7 @@ fn in_any_value_of_ty<'tcx>(cx: &ConstCx<'_, 'tcx>, ty: Ty<'tcx>) -> bool { // because that component may be part of an enum variant (e.g., // `Option::::Some`), in which case some values of this type may be // structural-match (`Option::None`). - traits::search_for_structural_match_violation(cx.body.span, cx.tcx, ty, true).is_some() + traits::search_for_structural_match_violation(cx.body.span, cx.tcx, ty, false).is_some() } fn in_adt_inherently<'tcx>( diff --git a/compiler/rustc_middle/src/ty/consts.rs b/compiler/rustc_middle/src/ty/consts.rs index a4e7a12bba3..f8792edc017 100644 --- a/compiler/rustc_middle/src/ty/consts.rs +++ b/compiler/rustc_middle/src/ty/consts.rs @@ -203,7 +203,7 @@ pub fn from_value(tcx: TyCtxt<'tcx>, val: ty::ValTree<'tcx>, ty: Ty<'tcx>) -> Se pub fn to_valtree(self) -> ty::ValTree<'tcx> { match self.kind() { ty::ConstKind::Value(valtree) => valtree, - _ => bug!("expected ConstKind::Value"), + _ => bug!("expected ConstKind::Value, got {:?}", self.kind()), } } diff --git a/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs b/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs index e32e0b11ba4..44faed3fa9f 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs @@ -120,7 +120,7 @@ fn adt_derive_msg(&self, adt_def: AdtDef<'tcx>) -> String { } fn search_for_structural_match_violation(&self, ty: Ty<'tcx>) -> Option { - traits::search_for_structural_match_violation(self.span, self.tcx(), ty, true).map( + traits::search_for_structural_match_violation(self.span, self.tcx(), ty, false).map( |non_sm_ty| { with_no_trimmed_paths!(match non_sm_ty.kind { traits::NonStructuralMatchTyKind::Adt(adt) => self.adt_derive_msg(adt), @@ -139,6 +139,12 @@ fn search_for_structural_match_violation(&self, ty: Ty<'tcx>) -> Option traits::NonStructuralMatchTyKind::Float => { "floating-point numbers cannot be used in patterns".to_string() } + traits::NonStructuralMatchTyKind::FnPtr => { + "function pointers cannot be used in patterns".to_string() + } + traits::NonStructuralMatchTyKind::RawPtr => { + "raw pointers cannot be used in patterns".to_string() + } traits::NonStructuralMatchTyKind::Param => { bug!("use of a constant whose type is a parameter inside a pattern") } diff --git a/compiler/rustc_trait_selection/src/traits/structural_match.rs b/compiler/rustc_trait_selection/src/traits/structural_match.rs index 6c0b83fbd03..25a66bb9d08 100644 --- a/compiler/rustc_trait_selection/src/traits/structural_match.rs +++ b/compiler/rustc_trait_selection/src/traits/structural_match.rs @@ -27,6 +27,8 @@ pub enum NonStructuralMatchTyKind<'tcx> { Generator, Projection, Float, + FnPtr, + RawPtr, } /// This method traverses the structure of `ty`, trying to find an @@ -55,14 +57,15 @@ pub enum NonStructuralMatchTyKind<'tcx> { /// that arose when the requirement was not enforced completely, see /// Rust RFC 1445, rust-lang/rust#61188, and rust-lang/rust#62307. /// -/// The floats_allowed flag is used to deny constants in floating point +/// When the `valtree_semantics` flag is set, then we also deny additional +/// types that are not evaluatable to valtrees, such as floats and fn ptrs. pub fn search_for_structural_match_violation<'tcx>( span: Span, tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, - floats_allowed: bool, + valtree_semantics: bool, ) -> Option> { - ty.visit_with(&mut Search { tcx, span, seen: FxHashSet::default(), floats_allowed }) + ty.visit_with(&mut Search { tcx, span, seen: FxHashSet::default(), valtree_semantics }) .break_value() } @@ -125,7 +128,9 @@ struct Search<'tcx> { /// we will not recur on them again. seen: FxHashSet, - floats_allowed: bool, + // Additionally deny things that have been allowed in patterns, + // but are not evaluatable to a valtree, such as floats and fn ptrs. + valtree_semantics: bool, } impl<'tcx> Search<'tcx> { @@ -170,24 +175,7 @@ fn visit_ty(&mut self, ty: Ty<'tcx>) -> ControlFlow { let kind = NonStructuralMatchTyKind::Generator; return ControlFlow::Break(NonStructuralMatchTy { ty, kind }); } - ty::RawPtr(..) => { - // structural-match ignores substructure of - // `*const _`/`*mut _`, so skip `super_visit_with`. - // - // For example, if you have: - // ``` - // struct NonStructural; - // #[derive(PartialEq, Eq)] - // struct T(*const NonStructural); - // const C: T = T(std::ptr::null()); - // ``` - // - // Even though `NonStructural` does not implement `PartialEq`, - // structural equality on `T` does not recur into the raw - // pointer. Therefore, one can still use `C` in a pattern. - return ControlFlow::CONTINUE; - } - ty::FnDef(..) | ty::FnPtr(..) => { + ty::FnDef(..) => { // Types of formals and return in `fn(_) -> _` are also irrelevant; // so we do not recur into them via `super_visit_with` return ControlFlow::CONTINUE; @@ -206,8 +194,44 @@ fn visit_ty(&mut self, ty: Ty<'tcx>) -> ControlFlow { return ControlFlow::CONTINUE; } + ty::FnPtr(..) => { + if !self.valtree_semantics { + return ControlFlow::CONTINUE; + } else { + return ControlFlow::Break(NonStructuralMatchTy { + ty, + kind: NonStructuralMatchTyKind::FnPtr, + }); + } + } + + ty::RawPtr(..) => { + if !self.valtree_semantics { + // structural-match ignores substructure of + // `*const _`/`*mut _`, so skip `super_visit_with`. + // + // For example, if you have: + // ``` + // struct NonStructural; + // #[derive(PartialEq, Eq)] + // struct T(*const NonStructural); + // const C: T = T(std::ptr::null()); + // ``` + // + // Even though `NonStructural` does not implement `PartialEq`, + // structural equality on `T` does not recur into the raw + // pointer. Therefore, one can still use `C` in a pattern. + return ControlFlow::CONTINUE; + } else { + return ControlFlow::Break(NonStructuralMatchTy { + ty, + kind: NonStructuralMatchTyKind::FnPtr, + }); + } + } + ty::Float(_) => { - if self.floats_allowed { + if !self.valtree_semantics { return ControlFlow::CONTINUE; } else { return ControlFlow::Break(NonStructuralMatchTy { diff --git a/compiler/rustc_typeck/src/check/wfcheck.rs b/compiler/rustc_typeck/src/check/wfcheck.rs index b8e998229ba..324b229fa59 100644 --- a/compiler/rustc_typeck/src/check/wfcheck.rs +++ b/compiler/rustc_typeck/src/check/wfcheck.rs @@ -848,29 +848,13 @@ fn check_param_wf(tcx: TyCtxt<'_>, param: &hir::GenericParam<'_>) { let ty = tcx.type_of(tcx.hir().local_def_id(param.hir_id)); if tcx.features().adt_const_params { - let err = match ty.peel_refs().kind() { - ty::FnPtr(_) => Some("function pointers"), - ty::RawPtr(_) => Some("raw pointers"), - _ => None, - }; - - if let Some(unsupported_type) = err { - tcx.sess.span_err( - hir_ty.span, - &format!( - "using {} as const generic parameters is forbidden", - unsupported_type - ), - ); - } - if let Some(non_structural_match_ty) = - traits::search_for_structural_match_violation(param.span, tcx, ty, false) + traits::search_for_structural_match_violation(param.span, tcx, ty, true) { // We use the same error code in both branches, because this is really the same // issue: we just special-case the message for type parameters to make it // clearer. - match ty.peel_refs().kind() { + match non_structural_match_ty.ty.kind() { ty::Param(_) => { // Const parameters may not have type parameters as their types, // because we cannot be sure that the type parameter derives `PartialEq` @@ -902,6 +886,24 @@ fn check_param_wf(tcx: TyCtxt<'_>, param: &hir::GenericParam<'_>) { .note("floats do not derive `Eq` or `Ord`, which are required for const parameters") .emit(); } + ty::FnPtr(_) => { + struct_span_err!( + tcx.sess, + hir_ty.span, + E0741, + "using function pointers as const generic parameters is forbidden", + ) + .emit(); + } + ty::RawPtr(_) => { + struct_span_err!( + tcx.sess, + hir_ty.span, + E0741, + "using raw pointers as const generic parameters is forbidden", + ) + .emit(); + } _ => { let mut diag = struct_span_err!( tcx.sess, diff --git a/src/test/ui/const-generics/fn-const-param-call.full.stderr b/src/test/ui/const-generics/fn-const-param-call.full.stderr index d984449e6ca..b55c2449858 100644 --- a/src/test/ui/const-generics/fn-const-param-call.full.stderr +++ b/src/test/ui/const-generics/fn-const-param-call.full.stderr @@ -1,10 +1,10 @@ -error: using function pointers as const generic parameters is forbidden +error[E0741]: using function pointers as const generic parameters is forbidden --> $DIR/fn-const-param-call.rs:11:25 | LL | struct Wrapper u32>; | ^^^^^^^^^^^ -error: using function pointers as const generic parameters is forbidden +error[E0741]: using function pointers as const generic parameters is forbidden --> $DIR/fn-const-param-call.rs:13:15 | LL | impl u32> Wrapper { @@ -12,3 +12,4 @@ LL | impl u32> Wrapper { error: aborting due to 2 previous errors +For more information about this error, try `rustc --explain E0741`. diff --git a/src/test/ui/const-generics/fn-const-param-infer.full.stderr b/src/test/ui/const-generics/fn-const-param-infer.full.stderr index f0767a10994..2d66a192332 100644 --- a/src/test/ui/const-generics/fn-const-param-infer.full.stderr +++ b/src/test/ui/const-generics/fn-const-param-infer.full.stderr @@ -1,4 +1,4 @@ -error: using function pointers as const generic parameters is forbidden +error[E0741]: using function pointers as const generic parameters is forbidden --> $DIR/fn-const-param-infer.rs:6:25 | LL | struct Checked bool>; @@ -6,3 +6,4 @@ LL | struct Checked bool>; error: aborting due to previous error +For more information about this error, try `rustc --explain E0741`. diff --git a/src/test/ui/const-generics/issues/issue-71381.full.stderr b/src/test/ui/const-generics/issues/issue-71381.full.stderr index 3950317b370..e17cf96aa3e 100644 --- a/src/test/ui/const-generics/issues/issue-71381.full.stderr +++ b/src/test/ui/const-generics/issues/issue-71381.full.stderr @@ -10,13 +10,13 @@ error[E0770]: the type of const parameters must not depend on other generic para LL | const FN: unsafe extern "C" fn(Args), | ^^^^ the type must not depend on the parameter `Args` -error: using function pointers as const generic parameters is forbidden +error[E0741]: using function pointers as const generic parameters is forbidden --> $DIR/issue-71381.rs:14:61 | LL | pub fn call_me(&self) { | ^^^^^^^^^^^^^^^^^^^^^^^^^^ -error: using function pointers as const generic parameters is forbidden +error[E0741]: using function pointers as const generic parameters is forbidden --> $DIR/issue-71381.rs:23:19 | LL | const FN: unsafe extern "C" fn(Args), @@ -24,4 +24,5 @@ LL | const FN: unsafe extern "C" fn(Args), error: aborting due to 4 previous errors -For more information about this error, try `rustc --explain E0770`. +Some errors have detailed explanations: E0741, E0770. +For more information about an error, try `rustc --explain E0741`. diff --git a/src/test/ui/const-generics/issues/issue-71382.full.stderr b/src/test/ui/const-generics/issues/issue-71382.full.stderr index 715037bd5f1..ab2a4e64a83 100644 --- a/src/test/ui/const-generics/issues/issue-71382.full.stderr +++ b/src/test/ui/const-generics/issues/issue-71382.full.stderr @@ -1,4 +1,4 @@ -error: using function pointers as const generic parameters is forbidden +error[E0741]: using function pointers as const generic parameters is forbidden --> $DIR/issue-71382.rs:16:23 | LL | fn test(&self) { @@ -6,3 +6,4 @@ LL | fn test(&self) { error: aborting due to previous error +For more information about this error, try `rustc --explain E0741`. diff --git a/src/test/ui/const-generics/issues/issue-71611.full.stderr b/src/test/ui/const-generics/issues/issue-71611.full.stderr index 01a85b745ce..656aa29e19b 100644 --- a/src/test/ui/const-generics/issues/issue-71611.full.stderr +++ b/src/test/ui/const-generics/issues/issue-71611.full.stderr @@ -4,7 +4,7 @@ error[E0770]: the type of const parameters must not depend on other generic para LL | fn func(outer: A) { | ^ the type must not depend on the parameter `A` -error: using function pointers as const generic parameters is forbidden +error[E0741]: using function pointers as const generic parameters is forbidden --> $DIR/issue-71611.rs:5:21 | LL | fn func(outer: A) { @@ -12,4 +12,5 @@ LL | fn func(outer: A) { error: aborting due to 2 previous errors -For more information about this error, try `rustc --explain E0770`. +Some errors have detailed explanations: E0741, E0770. +For more information about an error, try `rustc --explain E0741`. diff --git a/src/test/ui/const-generics/issues/issue-72352.full.stderr b/src/test/ui/const-generics/issues/issue-72352.full.stderr index eedd73c4dcc..92580b33685 100644 --- a/src/test/ui/const-generics/issues/issue-72352.full.stderr +++ b/src/test/ui/const-generics/issues/issue-72352.full.stderr @@ -1,4 +1,4 @@ -error: using function pointers as const generic parameters is forbidden +error[E0741]: using function pointers as const generic parameters is forbidden --> $DIR/issue-72352.rs:7:42 | LL | unsafe fn unsafely_do_the_thing usize>(ptr: *const i8) -> usize { @@ -6,3 +6,4 @@ LL | unsafe fn unsafely_do_the_thing usize>(ptr: *const i8 error: aborting due to previous error +For more information about this error, try `rustc --explain E0741`. diff --git a/src/test/ui/const-generics/issues/issue-99641.rs b/src/test/ui/const-generics/issues/issue-99641.rs new file mode 100644 index 00000000000..fae6d3fc41f --- /dev/null +++ b/src/test/ui/const-generics/issues/issue-99641.rs @@ -0,0 +1,18 @@ +#![feature(adt_const_params)] +#![allow(incomplete_features)] + +fn main() { + pub struct Color; + //~^ ERROR using function pointers + + impl Color { + //~^ ERROR using function pointers + pub fn new() -> Self { + Color:: + } + } + + pub const D65: (fn(),) = (|| {},); + + Color::::new(); +} diff --git a/src/test/ui/const-generics/issues/issue-99641.stderr b/src/test/ui/const-generics/issues/issue-99641.stderr new file mode 100644 index 00000000000..349ebba08d5 --- /dev/null +++ b/src/test/ui/const-generics/issues/issue-99641.stderr @@ -0,0 +1,15 @@ +error[E0741]: using function pointers as const generic parameters is forbidden + --> $DIR/issue-99641.rs:5:35 + | +LL | pub struct Color; + | ^^^^^^^ + +error[E0741]: using function pointers as const generic parameters is forbidden + --> $DIR/issue-99641.rs:8:23 + | +LL | impl Color { + | ^^^^^^^ + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0741`. diff --git a/src/test/ui/const-generics/raw-ptr-const-param-deref.full.stderr b/src/test/ui/const-generics/raw-ptr-const-param-deref.full.stderr index 04bc46cb4ab..657eee2be24 100644 --- a/src/test/ui/const-generics/raw-ptr-const-param-deref.full.stderr +++ b/src/test/ui/const-generics/raw-ptr-const-param-deref.full.stderr @@ -1,10 +1,10 @@ -error: using raw pointers as const generic parameters is forbidden +error[E0741]: using raw pointers as const generic parameters is forbidden --> $DIR/raw-ptr-const-param-deref.rs:9:23 | LL | struct Const; | ^^^^^^^^^^ -error: using raw pointers as const generic parameters is forbidden +error[E0741]: using raw pointers as const generic parameters is forbidden --> $DIR/raw-ptr-const-param-deref.rs:11:15 | LL | impl Const

{ @@ -12,3 +12,4 @@ LL | impl Const

{ error: aborting due to 2 previous errors +For more information about this error, try `rustc --explain E0741`. diff --git a/src/test/ui/const-generics/raw-ptr-const-param.full.stderr b/src/test/ui/const-generics/raw-ptr-const-param.full.stderr index 310422aafcd..69f1aae5681 100644 --- a/src/test/ui/const-generics/raw-ptr-const-param.full.stderr +++ b/src/test/ui/const-generics/raw-ptr-const-param.full.stderr @@ -1,4 +1,4 @@ -error: using raw pointers as const generic parameters is forbidden +error[E0741]: using raw pointers as const generic parameters is forbidden --> $DIR/raw-ptr-const-param.rs:6:23 | LL | struct Const; @@ -6,3 +6,4 @@ LL | struct Const; error: aborting due to previous error +For more information about this error, try `rustc --explain E0741`. diff --git a/src/test/ui/consts/refs_check_const_eq-issue-88384.rs b/src/test/ui/consts/refs_check_const_eq-issue-88384.rs index 204d18ea25d..1496b28bd3e 100644 --- a/src/test/ui/consts/refs_check_const_eq-issue-88384.rs +++ b/src/test/ui/consts/refs_check_const_eq-issue-88384.rs @@ -1,5 +1,3 @@ -// check-pass - #![feature(fn_traits)] #![feature(adt_const_params)] //~^ WARNING the feature `adt_const_params` is incomplete @@ -10,8 +8,10 @@ struct CompileTimeSettings{ } struct Foo; +//~^ ERROR using function pointers as const generic parameters is forbidden impl Foo { + //~^ ERROR using function pointers as const generic parameters is forbidden fn call_hooks(){ } } diff --git a/src/test/ui/consts/refs_check_const_eq-issue-88384.stderr b/src/test/ui/consts/refs_check_const_eq-issue-88384.stderr index f2bad2f5527..4f2f5e244b6 100644 --- a/src/test/ui/consts/refs_check_const_eq-issue-88384.stderr +++ b/src/test/ui/consts/refs_check_const_eq-issue-88384.stderr @@ -1,5 +1,5 @@ warning: the feature `adt_const_params` is incomplete and may not be safe to use and/or cause compiler crashes - --> $DIR/refs_check_const_eq-issue-88384.rs:4:12 + --> $DIR/refs_check_const_eq-issue-88384.rs:2:12 | LL | #![feature(adt_const_params)] | ^^^^^^^^^^^^^^^^ @@ -7,5 +7,18 @@ LL | #![feature(adt_const_params)] = note: `#[warn(incomplete_features)]` on by default = note: see issue #95174 for more information -warning: 1 warning emitted +error[E0741]: using function pointers as const generic parameters is forbidden + --> $DIR/refs_check_const_eq-issue-88384.rs:10:21 + | +LL | struct Foo; + | ^^^^^^^^^^^^^^^^^^^ +error[E0741]: using function pointers as const generic parameters is forbidden + --> $DIR/refs_check_const_eq-issue-88384.rs:13:15 + | +LL | impl Foo { + | ^^^^^^^^^^^^^^^^^^^ + +error: aborting due to 2 previous errors; 1 warning emitted + +For more information about this error, try `rustc --explain E0741`.