Rollup merge of #107646 - estebank:specific-span, r=compiler-errors

[rust.git] / compiler / rustc_lint / src / types.rs

diff --git a/compiler/rustc_lint/src/types.rs b/compiler/rustc_lint/src/types.rs
index 625258991a387c71cccb8bfdb5aa64d72008e03b..b0a5d3674ad2795d75fdcefe041c68c2db19f7de 100644 (file)
--- a/compiler/rustc_lint/src/types.rs
+++ b/compiler/rustc_lint/src/types.rs
@@ -14,6 +14,7 @@
 use rustc_middle::ty::layout::{IntegerExt, LayoutOf, SizeSkeleton};
 use rustc_middle::ty::subst::SubstsRef;
 use rustc_middle::ty::{self, AdtKind, DefIdTree, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::source_map;
 use rustc_span::symbol::sym;
 use rustc_span::{Span, Symbol};
@@ -827,39 +828,39 @@ fn check_variant_for_ffi(
     ) -> FfiResult<'tcx> {
         use FfiResult::*;
 
-        if def.repr().transparent() {
+        let transparent_safety = def.repr().transparent().then(|| {
             // Can assume that at most one field is not a ZST, so only check
             // that field's type for FFI-safety.
             if let Some(field) = transparent_newtype_field(self.cx.tcx, variant) {
-                self.check_field_type_for_ffi(cache, field, substs)
+                return self.check_field_type_for_ffi(cache, field, substs);
             } else {
                 // All fields are ZSTs; this means that the type should behave
-                // like (), which is FFI-unsafe
+                // like (), which is FFI-unsafe... except if all fields are PhantomData,
+                // which is tested for below
                 FfiUnsafe { ty, reason: fluent::lint_improper_ctypes_struct_zst, help: None }
             }
-        } else {
-            // We can't completely trust repr(C) markings; make sure the fields are
-            // actually safe.
-            let mut all_phantom = !variant.fields.is_empty();
-            for field in &variant.fields {
-                match self.check_field_type_for_ffi(cache, &field, substs) {
-                    FfiSafe => {
-                        all_phantom = false;
-                    }
-                    FfiPhantom(..) if def.is_enum() => {
-                        return FfiUnsafe {
-                            ty,
-                            reason: fluent::lint_improper_ctypes_enum_phantomdata,
-                            help: None,
-                        };
-                    }
-                    FfiPhantom(..) => {}
-                    r => return r,
+        });
+        // We can't completely trust repr(C) markings; make sure the fields are
+        // actually safe.
+        let mut all_phantom = !variant.fields.is_empty();
+        for field in &variant.fields {
+            match self.check_field_type_for_ffi(cache, &field, substs) {
+                FfiSafe => {
+                    all_phantom = false;
                 }
+                FfiPhantom(..) if !def.repr().transparent() && def.is_enum() => {
+                    return FfiUnsafe {
+                        ty,
+                        reason: fluent::lint_improper_ctypes_enum_phantomdata,
+                        help: None,
+                    };
+                }
+                FfiPhantom(..) => {}
+                r => return transparent_safety.unwrap_or(r),
             }
-
-            if all_phantom { FfiPhantom(ty) } else { FfiSafe }
         }
+
+        if all_phantom { FfiPhantom(ty) } else { transparent_safety.unwrap_or(FfiSafe) }
     }
 
     /// Checks if the given type is "ffi-safe" (has a stable, well-defined
@@ -1107,6 +1108,7 @@ fn check_type_for_ffi(&self, cache: &mut FxHashSet<Ty<'tcx>>, ty: Ty<'tcx>) -> F
             | ty::Closure(..)
             | ty::Generator(..)
             | ty::GeneratorWitness(..)
+            | ty::GeneratorWitnessMIR(..)
             | ty::Placeholder(..)
             | ty::FnDef(..) => bug!("unexpected type in foreign function: {:?}", ty),
         }
@@ -1147,7 +1149,7 @@ impl<'tcx> ty::visit::TypeVisitor<'tcx> for ProhibitOpaqueTypes {
 
             fn visit_ty(&mut self, ty: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
                 if !ty.has_opaque_types() {
-                    return ControlFlow::CONTINUE;
+                    return ControlFlow::Continue(());
                 }
 
                 if let ty::Alias(ty::Opaque, ..) = ty.kind() {
@@ -1223,9 +1225,8 @@ fn check_type_for_ffi_and_report_errors(
         }
     }
 
-    fn check_foreign_fn(&mut self, id: hir::HirId, decl: &hir::FnDecl<'_>) {
-        let def_id = self.cx.tcx.hir().local_def_id(id);
-        let sig = self.cx.tcx.fn_sig(def_id);
+    fn check_foreign_fn(&mut self, def_id: LocalDefId, decl: &hir::FnDecl<'_>) {
+        let sig = self.cx.tcx.fn_sig(def_id).subst_identity();
         let sig = self.cx.tcx.erase_late_bound_regions(sig);
 
         for (input_ty, input_hir) in iter::zip(sig.inputs(), decl.inputs) {
@@ -1238,9 +1239,8 @@ fn check_foreign_fn(&mut self, id: hir::HirId, decl: &hir::FnDecl<'_>) {
         }
     }
 
-    fn check_foreign_static(&mut self, id: hir::HirId, span: Span) {
-        let def_id = self.cx.tcx.hir().local_def_id(id);
-        let ty = self.cx.tcx.type_of(def_id);
+    fn check_foreign_static(&mut self, id: hir::OwnerId, span: Span) {
+        let ty = self.cx.tcx.type_of(id);
         self.check_type_for_ffi_and_report_errors(span, ty, true, false);
     }
 
@@ -1260,10 +1260,10 @@ fn check_foreign_item(&mut self, cx: &LateContext<'_>, it: &hir::ForeignItem<'_>
         if !vis.is_internal_abi(abi) {
             match it.kind {
                 hir::ForeignItemKind::Fn(ref decl, _, _) => {
-                    vis.check_foreign_fn(it.hir_id(), decl);
+                    vis.check_foreign_fn(it.owner_id.def_id, decl);
                 }
                 hir::ForeignItemKind::Static(ref ty, _) => {
-                    vis.check_foreign_static(it.hir_id(), ty.span);
+                    vis.check_foreign_static(it.owner_id, ty.span);
                 }
                 hir::ForeignItemKind::Type => (),
             }
@@ -1279,7 +1279,7 @@ fn check_fn(
         decl: &'tcx hir::FnDecl<'_>,
         _: &'tcx hir::Body<'_>,
         _: Span,
-        hir_id: hir::HirId,
+        id: LocalDefId,
     ) {
         use hir::intravisit::FnKind;
 
@@ -1291,7 +1291,7 @@ fn check_fn(
 
         let mut vis = ImproperCTypesVisitor { cx, mode: CItemKind::Definition };
         if !vis.is_internal_abi(abi) {
-            vis.check_foreign_fn(hir_id, decl);
+            vis.check_foreign_fn(id, decl);
         }
     }
 }