Auto merge of #107443 - cjgillot:generator-less-query, r=compiler-errors

[rust.git] / compiler / rustc_mir_transform / src / check_packed_ref.rs

diff --git a/compiler/rustc_mir_transform/src/check_packed_ref.rs b/compiler/rustc_mir_transform/src/check_packed_ref.rs
index 51abcf51189f62b92984d8db0838fa1741f5d6fb..3e7571aa7a2e7f303fa0e02cc6fbd1f51f7906ac 100644 (file)
--- a/compiler/rustc_mir_transform/src/check_packed_ref.rs
+++ b/compiler/rustc_mir_transform/src/check_packed_ref.rs
@@ -1,17 +1,11 @@
-use rustc_hir::def_id::LocalDefId;
 use rustc_middle::mir::visit::{PlaceContext, Visitor};
 use rustc_middle::mir::*;
-use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::{self, TyCtxt};
 use rustc_session::lint::builtin::UNALIGNED_REFERENCES;
 
 use crate::util;
 use crate::MirLint;
 
-pub(crate) fn provide(providers: &mut Providers) {
-    *providers = Providers { unsafe_derive_on_repr_packed, ..*providers };
-}
-
 pub struct CheckPackedRef;
 
 impl<'tcx> MirLint<'tcx> for CheckPackedRef {
@@ -30,32 +24,6 @@ struct PackedRefChecker<'a, 'tcx> {
     source_info: SourceInfo,
 }
 
-fn unsafe_derive_on_repr_packed(tcx: TyCtxt<'_>, def_id: LocalDefId) {
-    let lint_hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
-
-    // FIXME: when we make this a hard error, this should have its
-    // own error code.
-
-    let extra = if tcx.generics_of(def_id).own_requires_monomorphization() {
-        "with type or const parameters"
-    } else {
-        "that does not derive `Copy`"
-    };
-    let message = format!(
-        "`{}` can't be derived on this `#[repr(packed)]` struct {}",
-        tcx.item_name(tcx.trait_id_of_impl(def_id.to_def_id()).expect("derived trait name")),
-        extra
-    );
-
-    tcx.struct_span_lint_hir(
-        UNALIGNED_REFERENCES,
-        lint_hir_id,
-        tcx.def_span(def_id),
-        message,
-        |lint| lint,
-    );
-}
-
 impl<'tcx> Visitor<'tcx> for PackedRefChecker<'_, 'tcx> {
     fn visit_terminator(&mut self, terminator: &Terminator<'tcx>, location: Location) {
         // Make sure we know where in the MIR we are.
@@ -73,14 +41,13 @@ fn visit_place(&mut self, place: &Place<'tcx>, context: PlaceContext, _location:
         if context.is_borrow() {
             if util::is_disaligned(self.tcx, self.body, self.param_env, *place) {
                 let def_id = self.body.source.instance.def_id();
-                if let Some(impl_def_id) = self
-                    .tcx
-                    .impl_of_method(def_id)
-                    .filter(|&def_id| self.tcx.is_builtin_derive(def_id))
+                if let Some(impl_def_id) = self.tcx.impl_of_method(def_id)
+                    && self.tcx.is_builtin_derive(impl_def_id)
                 {
-                    // If a method is defined in the local crate,
-                    // the impl containing that method should also be.
-                    self.tcx.ensure().unsafe_derive_on_repr_packed(impl_def_id.expect_local());
+                    // If we ever reach here it means that the generated derive
+                    // code is somehow doing an unaligned reference, which it
+                    // shouldn't do.
+                    unreachable!();
                 } else {
                     let source_info = self.source_info;
                     let lint_root = self.body.source_scopes[source_info.scope]