GCI: Check where-clauses for well-formedness at the def site
diff --git a/compiler/rustc_hir_analysis/src/check/wfcheck.rs b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
index 06c5e51..5070ab1 100644
--- a/compiler/rustc_hir_analysis/src/check/wfcheck.rs
+++ b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
@@ -298,11 +298,9 @@ 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)
+ check_static_item(tcx, def_id, ty.span, UnsizedHandling::Forbid)
}
- hir::ItemKind::Const(_, ty, ..) => {
- check_item_type(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);
@@ -366,7 +364,7 @@ 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(()),
}
@@ -1331,14 +1329,13 @@ 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.deeply_normalize(ty_span, Some(WellFormedLoc::Ty(item_id)), ty);
@@ -1388,6 +1385,34 @@ 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.deeply_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/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 0000000..39cdcc3
--- /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)]
+#![expect(incomplete_features)]
+
+const _: () = ()
+where
+ Vec<str>: 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 0000000..62db089
--- /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<str>: 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`.
