Rollup of 7 pull requests

compiler/rustc_middle/src/ty/sty.rs

@@ -2143,9 +2143,12 @@ impl<'tcx> TyS<'tcx> {
     }
 
     /// Returns the type of metadata for (potentially fat) pointers to this type.
-    pub fn ptr_metadata_ty(&'tcx self, tcx: TyCtxt<'tcx>) -> Ty<'tcx> {
-        // FIXME: should this normalize?
-        let tail = tcx.struct_tail_without_normalization(self);
+    pub fn ptr_metadata_ty(
+        &'tcx self,
+        tcx: TyCtxt<'tcx>,
+        normalize: impl FnMut(Ty<'tcx>) -> Ty<'tcx>,
+    ) -> Ty<'tcx> {
+        let tail = tcx.struct_tail_with_normalize(self, normalize);
         match tail.kind() {
             // Sized types
             ty::Infer(ty::IntVar(_) | ty::FloatVar(_))

compiler/rustc_middle/src/ty/util.rs

@@ -192,7 +192,7 @@ impl<'tcx> TyCtxt<'tcx> {
     pub fn struct_tail_with_normalize(
         self,
         mut ty: Ty<'tcx>,
-        normalize: impl Fn(Ty<'tcx>) -> Ty<'tcx>,
+        mut normalize: impl FnMut(Ty<'tcx>) -> Ty<'tcx>,
     ) -> Ty<'tcx> {
         let recursion_limit = self.recursion_limit();
         for iteration in 0.. {

compiler/rustc_mir_transform/src/generator.rs

@@ -726,9 +726,13 @@ fn sanitize_witness<'tcx>(
     saved_locals: &GeneratorSavedLocals,
 ) {
     let did = body.source.def_id();
-    let allowed_upvars = tcx.erase_regions(upvars);
+    let param_env = tcx.param_env(did);
+
+    let allowed_upvars = tcx.normalize_erasing_regions(param_env, upvars);
     let allowed = match witness.kind() {
-        &ty::GeneratorWitness(s) => tcx.erase_late_bound_regions(s),
+        &ty::GeneratorWitness(interior_tys) => {
+            tcx.normalize_erasing_late_bound_regions(param_env, interior_tys)
+        }
         _ => {
             tcx.sess.delay_span_bug(
                 body.span,
@@ -738,8 +742,6 @@ fn sanitize_witness<'tcx>(
         }
     };
 
-    let param_env = tcx.param_env(did);
-
     for (local, decl) in body.local_decls.iter_enumerated() {
         // Ignore locals which are internal or not saved between yields.
         if !saved_locals.contains(local) || decl.internal {

compiler/rustc_symbol_mangling/src/v0.rs

@@ -771,9 +771,9 @@ impl<'tcx> Printer<'tcx> for &mut SymbolMangler<'tcx> {
         disambiguated_data: &DisambiguatedDefPathData,
     ) -> Result<Self::Path, Self::Error> {
         let ns = match disambiguated_data.data {
-            // FIXME: It shouldn't be necessary to add anything for extern block segments,
-            // but we add 't' for backward compatibility.
-            DefPathData::ForeignMod => 't',
+            // Extern block segments can be skipped, names from extern blocks
+            // are effectively living in their parent modules.
+            DefPathData::ForeignMod => return print_prefix(self),
 
             // Uppercase categories are more stable than lowercase ones.
             DefPathData::TypeNs(_) => 't',

compiler/rustc_trait_selection/src/traits/project.rs

@@ -1400,8 +1400,17 @@ fn assemble_candidates_from_impls<'cx, 'tcx>(
                 // Any type with multiple potential metadata types is therefore not eligible.
                 let self_ty = selcx.infcx().shallow_resolve(obligation.predicate.self_ty());
 
-                // FIXME: should this normalize?
-                let tail = selcx.tcx().struct_tail_without_normalization(self_ty);
+                let tail = selcx.tcx().struct_tail_with_normalize(self_ty, |ty| {
+                    normalize_with_depth(
+                        selcx,
+                        obligation.param_env,
+                        obligation.cause.clone(),
+                        obligation.recursion_depth + 1,
+                        ty,
+                    )
+                    .value
+                });
+
                 match tail.kind() {
                     ty::Bool
                     | ty::Char
@@ -1435,7 +1444,12 @@ fn assemble_candidates_from_impls<'cx, 'tcx>(
                     | ty::Bound(..)
                     | ty::Placeholder(..)
                     | ty::Infer(..)
-                    | ty::Error(_) => false,
+                    | ty::Error(_) => {
+                        if tail.has_infer_types() {
+                            candidate_set.mark_ambiguous();
+                        }
+                        false
+                    },
                 }
             }
             super::ImplSource::Param(..) => {
@@ -1640,18 +1654,30 @@ fn confirm_pointee_candidate<'cx, 'tcx>(
     _: ImplSourcePointeeData,
 ) -> Progress<'tcx> {
     let tcx = selcx.tcx();
-
     let self_ty = selcx.infcx().shallow_resolve(obligation.predicate.self_ty());
-    let substs = tcx.mk_substs([self_ty.into()].iter());
 
+    let mut obligations = vec![];
+    let metadata_ty = self_ty.ptr_metadata_ty(tcx, |ty| {
+        normalize_with_depth_to(
+            selcx,
+            obligation.param_env,
+            obligation.cause.clone(),
+            obligation.recursion_depth + 1,
+            ty,
+            &mut obligations,
+        )
+    });
+
+    let substs = tcx.mk_substs([self_ty.into()].iter());
     let metadata_def_id = tcx.require_lang_item(LangItem::Metadata, None);
 
     let predicate = ty::ProjectionPredicate {
         projection_ty: ty::ProjectionTy { substs, item_def_id: metadata_def_id },
-        ty: self_ty.ptr_metadata_ty(tcx),
+        ty: metadata_ty,
     };
 
     confirm_param_env_candidate(selcx, obligation, ty::Binder::dummy(predicate), false)
+        .with_addl_obligations(obligations)
 }
 
 fn confirm_fn_pointer_candidate<'cx, 'tcx>(

library/alloc/src/alloc.rs

@@ -348,7 +348,6 @@ extern "Rust" {
     // This is the magic symbol to call the global alloc error handler.  rustc generates
     // it to call `__rg_oom` if there is a `#[alloc_error_handler]`, or to call the
     // default implementations below (`__rdl_oom`) otherwise.
-    #[rustc_allocator_nounwind]
     fn __rust_alloc_error_handler(size: usize, align: usize) -> !;
 }
 
@@ -367,7 +366,6 @@ extern "Rust" {
 #[stable(feature = "global_alloc", since = "1.28.0")]
 #[rustc_const_unstable(feature = "const_alloc_error", issue = "92523")]
 #[cfg(all(not(no_global_oom_handling), not(test)))]
-#[rustc_allocator_nounwind]
 #[cold]
 pub const fn handle_alloc_error(layout: Layout) -> ! {
     const fn ct_error(_: Layout) -> ! {
@@ -398,13 +396,13 @@ pub mod __alloc_error_handler {
 
     // if there is no `#[alloc_error_handler]`
     #[rustc_std_internal_symbol]
-    pub unsafe extern "C" fn __rdl_oom(size: usize, _align: usize) -> ! {
+    pub unsafe extern "C-unwind" fn __rdl_oom(size: usize, _align: usize) -> ! {
         panic!("memory allocation of {} bytes failed", size)
     }
 
     // if there is an `#[alloc_error_handler]`
     #[rustc_std_internal_symbol]
-    pub unsafe extern "C" fn __rg_oom(size: usize, align: usize) -> ! {
+    pub unsafe extern "C-unwind" fn __rg_oom(size: usize, align: usize) -> ! {
         let layout = unsafe { Layout::from_size_align_unchecked(size, align) };
         extern "Rust" {
             #[lang = "oom"]

library/alloc/src/lib.rs

@@ -168,6 +168,7 @@
 #![cfg_attr(test, feature(test))]
 #![feature(unboxed_closures)]
 #![feature(unsized_fn_params)]
+#![feature(c_unwind)]
 //
 // Rustdoc features:
 #![feature(doc_cfg)]