Auto merge of #92719 - matthiaskrgr:rollup-tc7oqys, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - #92248 (Normalize struct tail type when checking Pointee trait)
 - #92357 (Fix invalid removal of newlines from doc comments)
 - #92602 (Make source links look cleaner)
 - #92636 (Normalize generator-local types with unevaluated constants)
 - #92693 (Release notes: add `Result::unwrap_{,err_}unchecked`)
 - #92702 (Clean up lang_items::extract)
 - #92717 (update miri)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

RELEASES.md

@@ -41,6 +41,8 @@ Stabilized APIs
 - [`Path::is_symlink`]
 - [`{integer}::saturating_div`]
 - [`Option::unwrap_unchecked`]
+- [`Result::unwrap_unchecked`]
+- [`Result::unwrap_err_unchecked`]
 - [`NonZero{unsigned}::is_power_of_two`]
 
 These APIs are now usable in const contexts:
@@ -136,6 +138,8 @@ and related tools.
 [`Path::is_symlink`]: https://doc.rust-lang.org/stable/std/path/struct.Path.html#method.is_symlink
 [`{integer}::saturating_div`]: https://doc.rust-lang.org/stable/std/primitive.i8.html#method.saturating_div
 [`Option::unwrap_unchecked`]: https://doc.rust-lang.org/stable/std/option/enum.Option.html#method.unwrap_unchecked
+[`Result::unwrap_unchecked`]: https://doc.rust-lang.org/stable/std/result/enum.Result.html#method.unwrap_unchecked
+[`Result::unwrap_err_unchecked`]: https://doc.rust-lang.org/stable/std/result/enum.Result.html#method.unwrap_err_unchecked
 [`NonZero{unsigned}::is_power_of_two`]: https://doc.rust-lang.org/stable/std/num/struct.NonZeroU8.html#method.is_power_of_two
 [`unix::process::ExitStatusExt::core_dumped`]: https://doc.rust-lang.org/stable/std/os/unix/process/trait.ExitStatusExt.html#tymethod.core_dumped
 [`unix::process::ExitStatusExt::stopped_signal`]: https://doc.rust-lang.org/stable/std/os/unix/process/trait.ExitStatusExt.html#tymethod.stopped_signal

compiler/rustc_ast/src/util/comments.rs

@@ -34,18 +34,11 @@ pub fn beautify_doc_string(data: Symbol) -> Symbol {
             i += 1;
         }
 
-        while i < j && lines[i].trim().is_empty() {
-            i += 1;
-        }
         // like the first, a last line of all stars should be omitted
         if j > i && !lines[j - 1].is_empty() && lines[j - 1].chars().all(|c| c == '*') {
             j -= 1;
         }
 
-        while j > i && lines[j - 1].trim().is_empty() {
-            j -= 1;
-        }
-
         if i != 0 || j != lines.len() { Some((i, j)) } else { None }
     }
 

compiler/rustc_hir/src/lang_items.rs

@@ -151,20 +151,12 @@ impl<CTX> HashStable<CTX> for LangItem {
 /// Extracts the first `lang = "$name"` out of a list of attributes.
 /// The attributes `#[panic_handler]` and `#[alloc_error_handler]`
 /// are also extracted out when found.
-///
-/// About the `check_name` argument: passing in a `Session` would be simpler,
-/// because then we could call `Session::check_name` directly. But we want to
-/// avoid the need for `rustc_hir` to depend on `rustc_session`, so we
-/// use a closure instead.
-pub fn extract<'a, F>(check_name: F, attrs: &'a [ast::Attribute]) -> Option<(Symbol, Span)>
-where
-    F: Fn(&'a ast::Attribute, Symbol) -> bool,
-{
+pub fn extract(attrs: &[ast::Attribute]) -> Option<(Symbol, Span)> {
     attrs.iter().find_map(|attr| {
         Some(match attr {
-            _ if check_name(attr, sym::lang) => (attr.value_str()?, attr.span),
-            _ if check_name(attr, sym::panic_handler) => (sym::panic_impl, attr.span),
-            _ if check_name(attr, sym::alloc_error_handler) => (sym::oom, attr.span),
+            _ if attr.has_name(sym::lang) => (attr.value_str()?, attr.span),
+            _ if attr.has_name(sym::panic_handler) => (sym::panic_impl, attr.span),
+            _ if attr.has_name(sym::alloc_error_handler) => (sym::oom, attr.span),
             _ => return None,
         })
     })

compiler/rustc_hir/src/weak_lang_items.rs

@@ -18,13 +18,9 @@ pub static WEAK_ITEMS_REFS: SyncLazy<StableMap<Symbol, LangItem>> = SyncLazy::ne
     map
 });
 
-/// The `check_name` argument avoids the need for `rustc_hir` to depend on
-/// `rustc_session`.
-pub fn link_name<'a, F>(check_name: F, attrs: &'a [ast::Attribute]) -> Option<Symbol>
-where
-    F: Fn(&'a ast::Attribute, Symbol) -> bool
+pub fn link_name(attrs: &[ast::Attribute]) -> Option<Symbol>
 {
-    lang_items::extract(check_name, attrs).and_then(|(name, _)| {
+    lang_items::extract(attrs).and_then(|(name, _)| {
         $(if name == sym::$name {
             Some(sym::$sym)
         } else)* {

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_passes/src/lang_items.rs

@@ -10,7 +10,6 @@
 use crate::check_attr::target_from_impl_item;
 use crate::weak_lang_items;
 
-use rustc_ast::Attribute;
 use rustc_errors::{pluralize, struct_span_err};
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
@@ -57,8 +56,7 @@ impl<'tcx> LanguageItemCollector<'tcx> {
 
     fn check_for_lang(&mut self, actual_target: Target, hir_id: HirId) {
         let attrs = self.tcx.hir().attrs(hir_id);
-        let check_name = |attr: &Attribute, sym| attr.has_name(sym);
-        if let Some((value, span)) = extract(check_name, &attrs) {
+        if let Some((value, span)) = extract(&attrs) {
             match ITEM_REFS.get(&value).cloned() {
                 // Known lang item with attribute on correct target.
                 Some((item_index, expected_target)) if actual_target == expected_target => {

compiler/rustc_passes/src/weak_lang_items.rs

@@ -1,6 +1,5 @@
 //! Validity checking for weak lang items
 
-use rustc_ast::Attribute;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::struct_span_err;
 use rustc_hir as hir;
@@ -103,9 +102,8 @@ impl<'a, 'tcx, 'v> Visitor<'v> for Context<'a, 'tcx> {
     }
 
     fn visit_foreign_item(&mut self, i: &hir::ForeignItem<'_>) {
-        let check_name = |attr: &Attribute, sym| attr.has_name(sym);
         let attrs = self.tcx.hir().attrs(i.hir_id());
-        if let Some((lang_item, _)) = lang_items::extract(check_name, attrs) {
+        if let Some((lang_item, _)) = lang_items::extract(attrs) {
             self.register(lang_item, i.span);
         }
         intravisit::walk_foreign_item(self, i)

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>(