Auto merge of #134269 - matthiaskrgr:rollup-fkshwux, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - #133900 (Advent of `tests/ui` (misc cleanups and improvements) [1/N])
 - #133937 (Keep track of parse errors in `mod`s and don't emit resolve errors for paths involving them)
 - #133938 (`rustc_mir_dataflow` cleanups, including some renamings)
 - #134058 (interpret: reduce usage of TypingEnv::fully_monomorphized)
 - #134130 (Stop using driver queries in the public API)
 - #134140 (Add AST support for unsafe binders)
 - #134229 (Fix typos in docs on provenance)

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

compiler/rustc_hir/src/hir.rs

@@ -8,7 +8,7 @@ use rustc_ast::{
 };
 pub use rustc_ast::{
     BinOp, BinOpKind, BindingMode, BorrowKind, BoundConstness, BoundPolarity, ByRef, CaptureBy,
-    ImplPolarity, IsAuto, Movability, Mutability, UnOp,
+    ImplPolarity, IsAuto, Movability, Mutability, UnOp, UnsafeBinderCastKind,
 };
 use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_data_structures::sorted_map::SortedMap;
@@ -1740,6 +1740,7 @@ impl Expr<'_> {
             | ExprKind::Struct(..)
             | ExprKind::Tup(_)
             | ExprKind::Type(..)
+            | ExprKind::UnsafeBinderCast(..)
             | ExprKind::Err(_) => ExprPrecedence::Unambiguous,
 
             ExprKind::DropTemps(ref expr, ..) => expr.precedence(),
@@ -1769,6 +1770,9 @@ impl Expr<'_> {
             // https://github.com/rust-lang/rfcs/blob/master/text/0803-type-ascription.md#type-ascription-and-temporaries
             ExprKind::Type(ref e, _) => e.is_place_expr(allow_projections_from),
 
+            // Unsafe binder cast preserves place-ness of the sub-expression.
+            ExprKind::UnsafeBinderCast(_, e, _) => e.is_place_expr(allow_projections_from),
+
             ExprKind::Unary(UnOp::Deref, _) => true,
 
             ExprKind::Field(ref base, _) | ExprKind::Index(ref base, _, _) => {
@@ -1850,7 +1854,8 @@ impl Expr<'_> {
             | ExprKind::Field(base, _)
             | ExprKind::Index(base, _, _)
             | ExprKind::AddrOf(.., base)
-            | ExprKind::Cast(base, _) => {
+            | ExprKind::Cast(base, _)
+            | ExprKind::UnsafeBinderCast(_, base, _) => {
                 // This isn't exactly true for `Index` and all `Unary`, but we are using this
                 // method exclusively for diagnostics and there's a *cultural* pressure against
                 // them being used only for its side-effects.
@@ -2144,6 +2149,10 @@ pub enum ExprKind<'hir> {
     /// A suspension point for coroutines (i.e., `yield <expr>`).
     Yield(&'hir Expr<'hir>, YieldSource),
 
+    /// Operators which can be used to interconvert `unsafe` binder types.
+    /// e.g. `unsafe<'a> &'a i32` <=> `&i32`.
+    UnsafeBinderCast(UnsafeBinderCastKind, &'hir Expr<'hir>, Option<&'hir Ty<'hir>>),
+
     /// A placeholder for an expression that wasn't syntactically well formed in some way.
     Err(rustc_span::ErrorGuaranteed),
 }
@@ -2780,6 +2789,12 @@ pub struct BareFnTy<'hir> {
     pub param_names: &'hir [Ident],
 }
 
+#[derive(Debug, Clone, Copy, HashStable_Generic)]
+pub struct UnsafeBinderTy<'hir> {
+    pub generic_params: &'hir [GenericParam<'hir>],
+    pub inner_ty: &'hir Ty<'hir>,
+}
+
 #[derive(Debug, Clone, Copy, HashStable_Generic)]
 pub struct OpaqueTy<'hir> {
     pub hir_id: HirId,
@@ -2878,6 +2893,8 @@ pub enum TyKind<'hir> {
     Ref(&'hir Lifetime, MutTy<'hir>),
     /// A bare function (e.g., `fn(usize) -> bool`).
     BareFn(&'hir BareFnTy<'hir>),
+    /// An unsafe binder type (e.g. `unsafe<'a> Foo<'a>`).
+    UnsafeBinder(&'hir UnsafeBinderTy<'hir>),
     /// The never type (`!`).
     Never,
     /// A tuple (`(A, B, C, D, ...)`).

compiler/rustc_hir/src/intravisit.rs

@@ -857,6 +857,10 @@ pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr<'v>)
         ExprKind::Yield(ref subexpression, _) => {
             try_visit!(visitor.visit_expr(subexpression));
         }
+        ExprKind::UnsafeBinderCast(_kind, expr, ty) => {
+            try_visit!(visitor.visit_expr(expr));
+            visit_opt!(visitor, visit_ty, ty);
+        }
         ExprKind::Lit(_) | ExprKind::Err(_) => {}
     }
     V::Result::output()
@@ -886,6 +890,10 @@ pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty<'v>) -> V::Resul
             walk_list!(visitor, visit_generic_param, function_declaration.generic_params);
             try_visit!(visitor.visit_fn_decl(function_declaration.decl));
         }
+        TyKind::UnsafeBinder(ref unsafe_binder) => {
+            walk_list!(visitor, visit_generic_param, unsafe_binder.generic_params);
+            try_visit!(visitor.visit_ty(unsafe_binder.inner_ty));
+        }
         TyKind::Path(ref qpath) => {
             try_visit!(visitor.visit_qpath(qpath, typ.hir_id, typ.span));
         }