Auto merge of #3615 - RalfJung:rustup, r=RalfJung

Rustup

Author: bors

Cargo.lock

@@ -4343,6 +4343,7 @@ dependencies = [
  "rustc_hir_pretty",
  "rustc_index",
  "rustc_macros",
+ "rustc_next_trait_solver",
  "rustc_query_system",
  "rustc_serialize",
  "rustc_session",
@@ -4451,7 +4452,13 @@ dependencies = [
 name = "rustc_next_trait_solver"
 version = "0.0.0"
 dependencies = [
+ "derivative",
+ "rustc_ast_ir",
+ "rustc_data_structures",
+ "rustc_macros",
+ "rustc_serialize",
  "rustc_type_ir",
+ "rustc_type_ir_macros",
 ]
 
 [[package]]
@@ -4752,6 +4759,7 @@ name = "rustc_trait_selection"
 version = "0.0.0"
 dependencies = [
  "bitflags 2.5.0",
+ "derivative",
  "itertools 0.12.1",
  "rustc_ast",
  "rustc_ast_ir",
@@ -4767,10 +4775,13 @@ dependencies = [
  "rustc_next_trait_solver",
  "rustc_parse_format",
  "rustc_query_system",
+ "rustc_serialize",
  "rustc_session",
  "rustc_span",
  "rustc_target",
  "rustc_transmute",
+ "rustc_type_ir",
+ "rustc_type_ir_macros",
  "smallvec",
  "tracing",
 ]

compiler/rustc_abi/src/layout.rs

@@ -2,7 +2,6 @@ use std::borrow::{Borrow, Cow};
 use std::cmp;
 use std::fmt::{self, Write};
 use std::iter;
-use std::num::NonZero;
 use std::ops::Bound;
 use std::ops::Deref;
 
@@ -11,8 +10,8 @@ use tracing::debug;
 
 use crate::{
     Abi, AbiAndPrefAlign, Align, FieldsShape, IndexSlice, IndexVec, Integer, LayoutS, Niche,
-    Primitive, ReprOptions, Scalar, Size, StructKind, TagEncoding, TargetDataLayout, Variants,
-    WrappingRange,
+    NonZeroUsize, Primitive, ReprOptions, Scalar, Size, StructKind, TagEncoding, TargetDataLayout,
+    Variants, WrappingRange,
 };
 
 // A variant is absent if it's uninhabited and only has ZST fields.
@@ -328,7 +327,7 @@ pub trait LayoutCalculator {
 
         Some(LayoutS {
             variants: Variants::Single { index: VariantIdx::new(0) },
-            fields: FieldsShape::Union(NonZero::new(only_variant.len())?),
+            fields: FieldsShape::Union(NonZeroUsize::new(only_variant.len())?),
             abi,
             largest_niche: None,
             align,

compiler/rustc_abi/src/lib.rs

@@ -4,7 +4,7 @@
 #![cfg_attr(feature = "nightly", feature(rustdoc_internals))]
 
 use std::fmt;
-use std::num::{NonZero, ParseIntError};
+use std::num::{NonZeroUsize, ParseIntError};
 use std::ops::{Add, AddAssign, Mul, RangeInclusive, Sub};
 use std::str::FromStr;
 
@@ -1175,7 +1175,7 @@ pub enum FieldsShape<FieldIdx: Idx> {
     Primitive,
 
     /// All fields start at no offset. The `usize` is the field count.
-    Union(NonZero<usize>),
+    Union(NonZeroUsize),
 
     /// Array/vector-like placement, with all fields of identical types.
     Array { stride: Size, count: u64 },

compiler/rustc_ast/src/ast.rs

@@ -2105,7 +2105,7 @@ impl Ty {
 
 #[derive(Clone, Encodable, Decodable, Debug)]
 pub struct BareFnTy {
-    pub unsafety: Unsafe,
+    pub safety: Safety,
     pub ext: Extern,
     pub generic_params: ThinVec<GenericParam>,
     pub decl: P<FnDecl>,
@@ -2484,11 +2484,15 @@ pub enum IsAuto {
     No,
 }
 
+/// Safety of items.
 #[derive(Copy, Clone, PartialEq, Eq, Hash, Encodable, Decodable, Debug)]
 #[derive(HashStable_Generic)]
-pub enum Unsafe {
-    Yes(Span),
-    No,
+pub enum Safety {
+    /// `unsafe` an item is explicitly marked as `unsafe`.
+    Unsafe(Span),
+    /// Default means no value was provided, it will take a default value given the context in
+    /// which is used.
+    Default,
 }
 
 /// Describes what kind of coroutine markers, if any, a function has.
@@ -2692,7 +2696,7 @@ pub struct ModSpans {
 pub struct ForeignMod {
     /// `unsafe` keyword accepted syntactically for macro DSLs, but not
     /// semantically by Rust.
-    pub unsafety: Unsafe,
+    pub safety: Safety,
     pub abi: Option<StrLit>,
     pub items: ThinVec<P<ForeignItem>>,
 }
@@ -3011,8 +3015,8 @@ impl Extern {
 /// included in this struct (e.g., `async unsafe fn` or `const extern "C" fn`).
 #[derive(Clone, Copy, Encodable, Decodable, Debug)]
 pub struct FnHeader {
-    /// The `unsafe` keyword, if any
-    pub unsafety: Unsafe,
+    /// Whether this is `unsafe`, or has a default safety
+    pub safety: Safety,
     /// Whether this is `async`, `gen`, or nothing.
     pub coroutine_kind: Option<CoroutineKind>,
     /// The `const` keyword, if any
@@ -3024,8 +3028,8 @@ pub struct FnHeader {
 impl FnHeader {
     /// Does this function header have any qualifiers or is it empty?
     pub fn has_qualifiers(&self) -> bool {
-        let Self { unsafety, coroutine_kind, constness, ext } = self;
-        matches!(unsafety, Unsafe::Yes(_))
+        let Self { safety, coroutine_kind, constness, ext } = self;
+        matches!(safety, Safety::Unsafe(_))
             || coroutine_kind.is_some()
             || matches!(constness, Const::Yes(_))
             || !matches!(ext, Extern::None)
@@ -3035,7 +3039,7 @@ impl FnHeader {
 impl Default for FnHeader {
     fn default() -> FnHeader {
         FnHeader {
-            unsafety: Unsafe::No,
+            safety: Safety::Default,
             coroutine_kind: None,
             constness: Const::No,
             ext: Extern::None,
@@ -3045,7 +3049,7 @@ impl Default for FnHeader {
 
 #[derive(Clone, Encodable, Decodable, Debug)]
 pub struct Trait {
-    pub unsafety: Unsafe,
+    pub safety: Safety,
     pub is_auto: IsAuto,
     pub generics: Generics,
     pub bounds: GenericBounds,
@@ -3101,7 +3105,7 @@ pub struct TyAlias {
 #[derive(Clone, Encodable, Decodable, Debug)]
 pub struct Impl {
     pub defaultness: Defaultness,
-    pub unsafety: Unsafe,
+    pub safety: Safety,
     pub generics: Generics,
     pub constness: Const,
     pub polarity: ImplPolarity,
@@ -3209,7 +3213,7 @@ pub enum ItemKind {
     /// E.g., `mod foo;` or `mod foo { .. }`.
     /// `unsafe` keyword on modules is accepted syntactically for macro DSLs, but not
     /// semantically by Rust.
-    Mod(Unsafe, ModKind),
+    Mod(Safety, ModKind),
     /// An external module (`extern`).
     ///
     /// E.g., `extern {}` or `extern "C" {}`.

compiler/rustc_ast/src/mut_visit.rs

@@ -499,8 +499,8 @@ pub fn noop_visit_ty<T: MutVisitor>(ty: &mut P<Ty>, vis: &mut T) {
             vis.visit_mt(mt);
         }
         TyKind::BareFn(bft) => {
-            let BareFnTy { unsafety, ext: _, generic_params, decl, decl_span } = bft.deref_mut();
-            visit_unsafety(unsafety, vis);
+            let BareFnTy { safety, ext: _, generic_params, decl, decl_span } = bft.deref_mut();
+            visit_safety(safety, vis);
             generic_params.flat_map_in_place(|param| vis.flat_map_generic_param(param));
             vis.visit_fn_decl(decl);
             vis.visit_span(decl_span);
@@ -543,8 +543,8 @@ pub fn noop_visit_ty<T: MutVisitor>(ty: &mut P<Ty>, vis: &mut T) {
 }
 
 fn noop_visit_foreign_mod<T: MutVisitor>(foreign_mod: &mut ForeignMod, vis: &mut T) {
-    let ForeignMod { unsafety, abi: _, items } = foreign_mod;
-    visit_unsafety(unsafety, vis);
+    let ForeignMod { safety, abi: _, items } = foreign_mod;
+    visit_safety(safety, vis);
     items.flat_map_in_place(|item| vis.flat_map_foreign_item(item));
 }
 
@@ -859,10 +859,10 @@ fn visit_defaultness<T: MutVisitor>(defaultness: &mut Defaultness, vis: &mut T)
 }
 
 // No `noop_` prefix because there isn't a corresponding method in `MutVisitor`.
-fn visit_unsafety<T: MutVisitor>(unsafety: &mut Unsafe, vis: &mut T) {
-    match unsafety {
-        Unsafe::Yes(span) => vis.visit_span(span),
-        Unsafe::No => {}
+fn visit_safety<T: MutVisitor>(safety: &mut Safety, vis: &mut T) {
+    match safety {
+        Safety::Unsafe(span) => vis.visit_span(span),
+        Safety::Default => {}
     }
 }
 
@@ -1092,8 +1092,8 @@ impl NoopVisitItemKind for ItemKind {
                 vis.visit_generics(generics);
                 visit_opt(body, |body| vis.visit_block(body));
             }
-            ItemKind::Mod(unsafety, mod_kind) => {
-                visit_unsafety(unsafety, vis);
+            ItemKind::Mod(safety, mod_kind) => {
+                visit_safety(safety, vis);
                 match mod_kind {
                     ModKind::Loaded(items, _inline, ModSpans { inner_span, inject_use_span }) => {
                         vis.visit_span(inner_span);
@@ -1130,7 +1130,7 @@ impl NoopVisitItemKind for ItemKind {
             }
             ItemKind::Impl(box Impl {
                 defaultness,
-                unsafety,
+                safety,
                 generics,
                 constness,
                 polarity,
@@ -1139,16 +1139,16 @@ impl NoopVisitItemKind for ItemKind {
                 items,
             }) => {
                 visit_defaultness(defaultness, vis);
-                visit_unsafety(unsafety, vis);
+                visit_safety(safety, vis);
                 vis.visit_generics(generics);
                 visit_constness(constness, vis);
                 visit_polarity(polarity, vis);
                 visit_opt(of_trait, |trait_ref| vis.visit_trait_ref(trait_ref));
                 vis.visit_ty(self_ty);
                 items.flat_map_in_place(|item| vis.flat_map_impl_item(item));
             }
-            ItemKind::Trait(box Trait { unsafety, is_auto: _, generics, bounds, items }) => {
-                visit_unsafety(unsafety, vis);
+            ItemKind::Trait(box Trait { safety, is_auto: _, generics, bounds, items }) => {
+                visit_safety(safety, vis);
                 vis.visit_generics(generics);
                 visit_bounds(bounds, vis);
                 items.flat_map_in_place(|item| vis.flat_map_trait_item(item));
@@ -1254,10 +1254,10 @@ fn visit_const_item<T: MutVisitor>(
 }
 
 fn noop_visit_fn_header<T: MutVisitor>(header: &mut FnHeader, vis: &mut T) {
-    let FnHeader { unsafety, coroutine_kind, constness, ext: _ } = header;
+    let FnHeader { safety, coroutine_kind, constness, ext: _ } = header;
     visit_constness(constness, vis);
     coroutine_kind.as_mut().map(|coroutine_kind| vis.visit_coroutine_kind(coroutine_kind));
-    visit_unsafety(unsafety, vis);
+    visit_safety(safety, vis);
 }
 
 pub fn noop_visit_crate<T: MutVisitor>(krate: &mut Crate, vis: &mut T) {

compiler/rustc_ast/src/token.rs

@@ -881,6 +881,8 @@ pub enum NonterminalKind {
     },
     PatWithOr,
     Expr,
+    /// Matches an expression using the rules from edition 2021 and earlier.
+    Expr2021,
     Ty,
     Ident,
     Lifetime,
@@ -910,6 +912,7 @@ impl NonterminalKind {
             },
             sym::pat_param => NonterminalKind::PatParam { inferred: false },
             sym::expr => NonterminalKind::Expr,
+            sym::expr_2021 if edition().at_least_rust_2021() => NonterminalKind::Expr2021,
             sym::ty => NonterminalKind::Ty,
             sym::ident => NonterminalKind::Ident,
             sym::lifetime => NonterminalKind::Lifetime,
@@ -929,6 +932,7 @@ impl NonterminalKind {
             NonterminalKind::PatParam { inferred: false } => sym::pat_param,
             NonterminalKind::PatParam { inferred: true } | NonterminalKind::PatWithOr => sym::pat,
             NonterminalKind::Expr => sym::expr,
+            NonterminalKind::Expr2021 => sym::expr_2021,
             NonterminalKind::Ty => sym::ty,
             NonterminalKind::Ident => sym::ident,
             NonterminalKind::Lifetime => sym::lifetime,

compiler/rustc_ast/src/visit.rs

@@ -366,7 +366,7 @@ impl WalkItemKind for ItemKind {
             }
             ItemKind::Impl(box Impl {
                 defaultness: _,
-                unsafety: _,
+                safety: _,
                 generics,
                 constness: _,
                 polarity: _,
@@ -384,7 +384,7 @@ impl WalkItemKind for ItemKind {
                 try_visit!(visitor.visit_generics(generics));
                 try_visit!(visitor.visit_variant_data(struct_definition));
             }
-            ItemKind::Trait(box Trait { unsafety: _, is_auto: _, generics, bounds, items }) => {
+            ItemKind::Trait(box Trait { safety: _, is_auto: _, generics, bounds, items }) => {
                 try_visit!(visitor.visit_generics(generics));
                 walk_list!(visitor, visit_param_bound, bounds, BoundKind::SuperTraits);
                 walk_list!(visitor, visit_assoc_item, items, AssocCtxt::Trait);

compiler/rustc_ast_lowering/src/delegation.rs

@@ -188,7 +188,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 Asyncness::No => hir::IsAsync::NotAsync,
             };
             hir::FnHeader {
-                unsafety: sig.unsafety,
+                safety: sig.safety,
                 constness: self.tcx.constness(sig_id),
                 asyncness,
                 abi: sig.abi,
@@ -341,7 +341,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
 
     fn generate_header_error(&self) -> hir::FnHeader {
         hir::FnHeader {
-            unsafety: hir::Unsafety::Normal,
+            safety: hir::Safety::Safe,
             constness: hir::Constness::NotConst,
             asyncness: hir::IsAsync::NotAsync,
             abi: abi::Abi::Rust,