diff --git a/compiler/rustc_hir_analysis/src/check/wfcheck.rs b/compiler/rustc_hir_analysis/src/check/wfcheck.rs index fa36fe7971610..7a77decbabaeb 100644 --- a/compiler/rustc_hir_analysis/src/check/wfcheck.rs +++ b/compiler/rustc_hir_analysis/src/check/wfcheck.rs @@ -268,11 +268,9 @@ fn check_item<'tcx>(tcx: TyCtxt<'tcx>, item: &'tcx hir::Item<'tcx>) -> Result<() check_item_fn(tcx, def_id, ident, item.span, sig.decl) } hir::ItemKind::Static(_, ty, ..) => { - check_item_type(tcx, def_id, ty.span, UnsizedHandling::Forbid) - } - hir::ItemKind::Const(_, ty, ..) => { - check_item_type(tcx, def_id, ty.span, UnsizedHandling::Forbid) + check_static_item(tcx, def_id, ty.span, UnsizedHandling::Forbid) } + hir::ItemKind::Const(_, ty, ..) => check_const_item(tcx, def_id, ty.span, item.span), hir::ItemKind::Struct(_, _, hir_generics) => { let res = check_type_defn(tcx, item, false); check_variances_for_type_defn(tcx, item, hir_generics); @@ -335,7 +333,7 @@ fn check_foreign_item<'tcx>( check_item_fn(tcx, def_id, item.ident, item.span, sig.decl) } hir::ForeignItemKind::Static(ty, ..) => { - check_item_type(tcx, def_id, ty.span, UnsizedHandling::AllowIfForeignTail) + check_static_item(tcx, def_id, ty.span, UnsizedHandling::AllowIfForeignTail) } hir::ForeignItemKind::Type => Ok(()), } @@ -1300,14 +1298,13 @@ enum UnsizedHandling { AllowIfForeignTail, } -fn check_item_type( +#[instrument(level = "debug", skip(tcx, ty_span, unsized_handling))] +fn check_static_item( tcx: TyCtxt<'_>, item_id: LocalDefId, ty_span: Span, unsized_handling: UnsizedHandling, ) -> Result<(), ErrorGuaranteed> { - debug!("check_item_type: {:?}", item_id); - enter_wf_checking_ctxt(tcx, ty_span, item_id, |wfcx| { let ty = tcx.type_of(item_id).instantiate_identity(); let item_ty = wfcx.normalize(ty_span, Some(WellFormedLoc::Ty(item_id)), ty); @@ -1357,6 +1354,34 @@ fn check_item_type( }) } +fn check_const_item( + tcx: TyCtxt<'_>, + def_id: LocalDefId, + ty_span: Span, + item_span: Span, +) -> Result<(), ErrorGuaranteed> { + enter_wf_checking_ctxt(tcx, ty_span, def_id, |wfcx| { + let ty = tcx.type_of(def_id).instantiate_identity(); + let ty = wfcx.normalize(ty_span, Some(WellFormedLoc::Ty(def_id)), ty); + + wfcx.register_wf_obligation(ty_span, Some(WellFormedLoc::Ty(def_id)), ty.into()); + wfcx.register_bound( + traits::ObligationCause::new( + ty_span, + wfcx.body_def_id, + ObligationCauseCode::SizedConstOrStatic, + ), + wfcx.param_env, + ty, + tcx.require_lang_item(LangItem::Sized, None), + ); + + check_where_clauses(wfcx, item_span, def_id); + + Ok(()) + }) +} + #[instrument(level = "debug", skip(tcx, hir_self_ty, hir_trait_ref))] fn check_impl<'tcx>( tcx: TyCtxt<'tcx>, diff --git a/compiler/rustc_hir_analysis/src/lib.rs b/compiler/rustc_hir_analysis/src/lib.rs index 309b8f2c76138..5f339eca8dfa5 100644 --- a/compiler/rustc_hir_analysis/src/lib.rs +++ b/compiler/rustc_hir_analysis/src/lib.rs @@ -215,7 +215,9 @@ pub fn check_crate(tcx: TyCtxt<'_>) { tcx.ensure_ok().eval_static_initializer(item_def_id); check::maybe_check_static_with_link_section(tcx, item_def_id); } - DefKind::Const if tcx.generics_of(item_def_id).is_empty() => { + DefKind::Const if !tcx.generics_of(item_def_id).own_requires_monomorphization() => { + // FIXME(generic_const_items): Passing empty instead of identity args is fishy but + // seems to be fine for now. Revisit this! let instance = ty::Instance::new(item_def_id.into(), ty::GenericArgs::empty()); let cid = GlobalId { instance, promoted: None }; let typing_env = ty::TypingEnv::fully_monomorphized(); diff --git a/compiler/rustc_middle/src/mir/interpret/queries.rs b/compiler/rustc_middle/src/mir/interpret/queries.rs index e5d1dda3aa0f4..5394237897c58 100644 --- a/compiler/rustc_middle/src/mir/interpret/queries.rs +++ b/compiler/rustc_middle/src/mir/interpret/queries.rs @@ -9,7 +9,6 @@ use super::{ ReportedErrorInfo, }; use crate::mir; -use crate::query::TyCtxtEnsureOk; use crate::ty::{self, GenericArgs, TyCtxt, TypeVisitableExt}; impl<'tcx> TyCtxt<'tcx> { @@ -197,24 +196,3 @@ impl<'tcx> TyCtxt<'tcx> { } } } - -impl<'tcx> TyCtxtEnsureOk<'tcx> { - /// Evaluates a constant without providing any generic parameters. This is useful to evaluate consts - /// that can't take any generic arguments like const items or enum discriminants. If a - /// generic parameter is used within the constant `ErrorHandled::TooGeneric` will be returned. - #[instrument(skip(self), level = "debug")] - pub fn const_eval_poly(self, def_id: DefId) { - // In some situations def_id will have generic parameters within scope, but they aren't allowed - // to be used. So we can't use `Instance::mono`, instead we feed unresolved generic parameters - // into `const_eval` which will return `ErrorHandled::TooGeneric` if any of them are - // encountered. - let args = GenericArgs::identity_for_item(self.tcx, def_id); - let instance = ty::Instance::new(def_id, self.tcx.erase_regions(args)); - let cid = GlobalId { instance, promoted: None }; - let typing_env = ty::TypingEnv::post_analysis(self.tcx, def_id); - // Const-eval shouldn't depend on lifetimes at all, so we can erase them, which should - // improve caching of queries. - let inputs = self.tcx.erase_regions(typing_env.as_query_input(cid)); - self.eval_to_const_value_raw(inputs) - } -} diff --git a/compiler/rustc_monomorphize/src/collector.rs b/compiler/rustc_monomorphize/src/collector.rs index 76dad6b35714a..8f495bfb8fe8a 100644 --- a/compiler/rustc_monomorphize/src/collector.rs +++ b/compiler/rustc_monomorphize/src/collector.rs @@ -1465,7 +1465,7 @@ impl<'v> RootCollector<'_, 'v> { // But even just declaring them must collect the items they refer to // unless their generics require monomorphization. - if !self.tcx.generics_of(id.owner_id).requires_monomorphization(self.tcx) + if !self.tcx.generics_of(id.owner_id).own_requires_monomorphization() && let Ok(val) = self.tcx.const_eval_poly(id.owner_id.to_def_id()) { collect_const_value(self.tcx, val, self.output); diff --git a/tests/ui/generic-const-items/def-site-eval.fail.stderr b/tests/ui/generic-const-items/def-site-eval.fail.stderr index fa07f38552243..4e7d9d8154a0e 100644 --- a/tests/ui/generic-const-items/def-site-eval.fail.stderr +++ b/tests/ui/generic-const-items/def-site-eval.fail.stderr @@ -1,5 +1,5 @@ -error[E0080]: evaluation of `_::<'_>` failed - --> $DIR/def-site-eval.rs:14:20 +error[E0080]: evaluation of constant value failed + --> $DIR/def-site-eval.rs:13:20 | LL | const _<'_a>: () = panic!(); | ^^^^^^^^ evaluation panicked: explicit panic diff --git a/tests/ui/generic-const-items/def-site-eval.rs b/tests/ui/generic-const-items/def-site-eval.rs index 3ed7f96aed02c..d2b2348c98d82 100644 --- a/tests/ui/generic-const-items/def-site-eval.rs +++ b/tests/ui/generic-const-items/def-site-eval.rs @@ -4,13 +4,12 @@ #![allow(incomplete_features)] //@ revisions: fail pass -//@[fail] build-fail (we require monomorphization) -//@[pass] build-pass (we require monomorphization) +//@[pass] check-pass const _<_T>: () = panic!(); const _: () = panic!(); #[cfg(fail)] -const _<'_a>: () = panic!(); //[fail]~ ERROR evaluation of `_::<'_>` failed +const _<'_a>: () = panic!(); //[fail]~ ERROR evaluation of constant value failed fn main() {} diff --git a/tests/ui/generic-const-items/def-site-predicates-wf.rs b/tests/ui/generic-const-items/def-site-predicates-wf.rs new file mode 100644 index 0000000000000..ca1b0cc0027d0 --- /dev/null +++ b/tests/ui/generic-const-items/def-site-predicates-wf.rs @@ -0,0 +1,9 @@ +//! Ensure that we check the predicates for well-formedness at the definition site. +#![feature(generic_const_items)] +#![allow(incomplete_features)] + +const _: () = () +where + Vec: Sized; //~ ERROR the size for values of type `str` cannot be known at compilation time + +fn main() {} diff --git a/tests/ui/generic-const-items/def-site-predicates-wf.stderr b/tests/ui/generic-const-items/def-site-predicates-wf.stderr new file mode 100644 index 0000000000000..62db089fd5573 --- /dev/null +++ b/tests/ui/generic-const-items/def-site-predicates-wf.stderr @@ -0,0 +1,13 @@ +error[E0277]: the size for values of type `str` cannot be known at compilation time + --> $DIR/def-site-predicates-wf.rs:7:15 + | +LL | Vec: Sized; + | ^^^^^ doesn't have a size known at compile-time + | + = help: the trait `Sized` is not implemented for `str` +note: required by an implicit `Sized` bound in `Vec` + --> $SRC_DIR/alloc/src/vec/mod.rs:LL:COL + +error: aborting due to 1 previous error + +For more information about this error, try `rustc --explain E0277`.