Auto merge of #132277 - workingjubilee:rollup-5e6q6e4, r=workingjubilee

Rollup of 9 pull requests

Successful merges:

 - #130259 (Lower AST node id only once)
 - #131441 (Add a new trait `proc_macro::ToTokens`)
 - #132247 (stable_mir: Directly use types from rustc_abi)
 - #132249 (compiler: Add rustc_abi dependence to the compiler)
 - #132255 (Add `LayoutData::is_uninhabited` and use it)
 - #132258 ([rustdoc] Unify variant struct fields margins with struct fields)
 - #132260 (cg_llvm: Use a type-safe helper to cast `&str` and `&[u8]` to `*const c_char`)
 - #132261 (refactor: cleaner check to return None)
 - #132271 (Updating Fuchsia platform-support documentation)

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

Cargo.lock

@@ -3621,6 +3621,7 @@ version = "0.0.0"
 dependencies = [
  "annotate-snippets 0.11.4",
  "derive_setters",
+ "rustc_abi",
  "rustc_ast",
  "rustc_ast_pretty",
  "rustc_data_structures",
@@ -3718,6 +3719,7 @@ name = "rustc_hir_analysis"
 version = "0.0.0"
 dependencies = [
  "itertools",
+ "rustc_abi",
  "rustc_arena",
  "rustc_ast",
  "rustc_attr",
@@ -3906,6 +3908,7 @@ dependencies = [
 name = "rustc_lint"
 version = "0.0.0"
 dependencies = [
+ "rustc_abi",
  "rustc_ast",
  "rustc_ast_pretty",
  "rustc_attr",
@@ -3980,6 +3983,7 @@ dependencies = [
  "bitflags 2.6.0",
  "libloading",
  "odht",
+ "rustc_abi",
  "rustc_ast",
  "rustc_attr",
  "rustc_data_structures",
@@ -4074,6 +4078,7 @@ version = "0.0.0"
 dependencies = [
  "polonius-engine",
  "regex",
+ "rustc_abi",
  "rustc_ast",
  "rustc_data_structures",
  "rustc_errors",
@@ -4095,6 +4100,7 @@ version = "0.0.0"
 dependencies = [
  "either",
  "itertools",
+ "rustc_abi",
  "rustc_arena",
  "rustc_ast",
  "rustc_attr",
@@ -4187,6 +4193,7 @@ dependencies = [
 name = "rustc_passes"
 version = "0.0.0"
 dependencies = [
+ "rustc_abi",
  "rustc_ast",
  "rustc_ast_pretty",
  "rustc_attr",
@@ -4213,6 +4220,7 @@ name = "rustc_pattern_analysis"
 version = "0.0.0"
 dependencies = [
  "rustc-hash 2.0.0",
+ "rustc_abi",
  "rustc_apfloat",
  "rustc_arena",
  "rustc_data_structures",
@@ -4352,6 +4360,7 @@ dependencies = [
  "bitflags 2.6.0",
  "getopts",
  "libc",
+ "rustc_abi",
  "rustc_ast",
  "rustc_data_structures",
  "rustc_errors",
@@ -4415,6 +4424,7 @@ version = "0.0.0"
 dependencies = [
  "punycode",
  "rustc-demangle",
+ "rustc_abi",
  "rustc_data_structures",
  "rustc_errors",
  "rustc_hir",

compiler/rustc_abi/src/layout.rs

@@ -28,7 +28,7 @@ where
     VariantIdx: Idx,
     F: Deref<Target = &'a LayoutData<FieldIdx, VariantIdx>> + fmt::Debug,
 {
-    let uninhabited = fields.iter().any(|f| f.abi.is_uninhabited());
+    let uninhabited = fields.iter().any(|f| f.is_uninhabited());
     // We cannot ignore alignment; that might lead us to entirely discard a variant and
     // produce an enum that is less aligned than it should be!
     let is_1zst = fields.iter().all(|f| f.is_1zst());
@@ -681,7 +681,7 @@ impl<Cx: HasDataLayout> LayoutCalculator<Cx> {
         let discr_type = repr.discr_type();
         let bits = Integer::from_attr(dl, discr_type).size().bits();
         for (i, mut val) in discriminants {
-            if !repr.c() && variants[i].iter().any(|f| f.abi.is_uninhabited()) {
+            if !repr.c() && variants[i].iter().any(|f| f.is_uninhabited()) {
                 continue;
             }
             if discr_type.is_signed() {

compiler/rustc_abi/src/lib.rs

@@ -1652,6 +1652,11 @@ impl<FieldIdx: Idx, VariantIdx: Idx> LayoutData<FieldIdx, VariantIdx> {
         }
     }
 
+    /// Returns `true` if this is an uninhabited type
+    pub fn is_uninhabited(&self) -> bool {
+        self.abi.is_uninhabited()
+    }
+
     pub fn scalar<C: HasDataLayout>(cx: &C, scalar: Scalar) -> Self {
         let largest_niche = Niche::from_scalar(cx, Size::ZERO, scalar);
         let size = scalar.size(cx);

compiler/rustc_ast_lowering/src/block.rs

@@ -10,17 +10,18 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         b: &Block,
         targeted_by_break: bool,
     ) -> &'hir hir::Block<'hir> {
-        self.arena.alloc(self.lower_block_noalloc(b, targeted_by_break))
+        let hir_id = self.lower_node_id(b.id);
+        self.arena.alloc(self.lower_block_noalloc(hir_id, b, targeted_by_break))
     }
 
     pub(super) fn lower_block_noalloc(
         &mut self,
+        hir_id: hir::HirId,
         b: &Block,
         targeted_by_break: bool,
     ) -> hir::Block<'hir> {
         let (stmts, expr) = self.lower_stmts(&b.stmts);
         let rules = self.lower_block_check_mode(&b.rules);
-        let hir_id = self.lower_node_id(b.id);
         hir::Block { hir_id, stmts, expr, rules, span: self.lower_span(b.span), targeted_by_break }
     }
 

compiler/rustc_ast_lowering/src/delegation.rs

@@ -259,10 +259,11 @@ impl<'hir> LoweringContext<'_, 'hir> {
                         self_param_id: pat_node_id,
                     };
                     self_resolver.visit_block(block);
+                    // Target expr needs to lower `self` path.
+                    this.ident_and_label_to_local_id.insert(pat_node_id, param.pat.hir_id.local_id);
                     this.lower_target_expr(&block)
                 } else {
-                    let pat_hir_id = this.lower_node_id(pat_node_id);
+                    this.generate_arg(param.pat.hir_id, span)
-                    this.generate_arg(pat_hir_id, span)
                 };
                 args.push(arg);
             }

compiler/rustc_ast_lowering/src/expr.rs

@@ -70,8 +70,8 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 _ => (),
             }
 
-            let hir_id = self.lower_node_id(e.id);
+            let expr_hir_id = self.lower_node_id(e.id);
-            self.lower_attrs(hir_id, &e.attrs);
+            self.lower_attrs(expr_hir_id, &e.attrs);
 
             let kind = match &e.kind {
                 ExprKind::Array(exprs) => hir::ExprKind::Array(self.lower_exprs(exprs)),
@@ -175,18 +175,25 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 ExprKind::If(cond, then, else_opt) => {
                     self.lower_expr_if(cond, then, else_opt.as_deref())
                 }
-                ExprKind::While(cond, body, opt_label) => self.with_loop_scope(e.id, |this| {
+                ExprKind::While(cond, body, opt_label) => {
-                    let span = this.mark_span_with_reason(DesugaringKind::WhileLoop, e.span, None);
+                    self.with_loop_scope(expr_hir_id, |this| {
-                    this.lower_expr_while_in_loop_scope(span, cond, body, *opt_label)
+                        let span =
-                }),
+                            this.mark_span_with_reason(DesugaringKind::WhileLoop, e.span, None);
-                ExprKind::Loop(body, opt_label, span) => self.with_loop_scope(e.id, |this| {
+                        let opt_label = this.lower_label(*opt_label, e.id, expr_hir_id);
-                    hir::ExprKind::Loop(
+                        this.lower_expr_while_in_loop_scope(span, cond, body, opt_label)
-                        this.lower_block(body, false),
+                    })
-                        this.lower_label(*opt_label),
+                }
-                        hir::LoopSource::Loop,
+                ExprKind::Loop(body, opt_label, span) => {
-                        this.lower_span(*span),
+                    self.with_loop_scope(expr_hir_id, |this| {
-                    )
+                        let opt_label = this.lower_label(*opt_label, e.id, expr_hir_id);
-                }),
+                        hir::ExprKind::Loop(
+                            this.lower_block(body, false),
+                            opt_label,
+                            hir::LoopSource::Loop,
+                            this.lower_span(*span),
+                        )
+                    })
+                }
                 ExprKind::TryBlock(body) => self.lower_expr_try_block(body),
                 ExprKind::Match(expr, arms, kind) => hir::ExprKind::Match(
                     self.lower_expr(expr),
@@ -212,7 +219,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                         binder,
                         *capture_clause,
                         e.id,
-                        hir_id,
+                        expr_hir_id,
                         *coroutine_kind,
                         fn_decl,
                         body,
@@ -223,7 +230,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                         binder,
                         *capture_clause,
                         e.id,
-                        hir_id,
+                        expr_hir_id,
                         *constness,
                         *movability,
                         fn_decl,
@@ -250,8 +257,16 @@ impl<'hir> LoweringContext<'_, 'hir> {
                     )
                 }
                 ExprKind::Block(blk, opt_label) => {
-                    let opt_label = self.lower_label(*opt_label);
+                    // Different from loops, label of block resolves to block id rather than
-                    hir::ExprKind::Block(self.lower_block(blk, opt_label.is_some()), opt_label)
+                    // expr node id.
+                    let block_hir_id = self.lower_node_id(blk.id);
+                    let opt_label = self.lower_label(*opt_label, blk.id, block_hir_id);
+                    let hir_block = self.arena.alloc(self.lower_block_noalloc(
+                        block_hir_id,
+                        blk,
+                        opt_label.is_some(),
+                    ));
+                    hir::ExprKind::Block(hir_block, opt_label)
                 }
                 ExprKind::Assign(el, er, span) => self.lower_expr_assign(el, er, *span, e.span),
                 ExprKind::AssignOp(op, el, er) => hir::ExprKind::AssignOp(
@@ -354,7 +369,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 ExprKind::MacCall(_) => panic!("{:?} shouldn't exist here", e.span),
             };
 
-            hir::Expr { hir_id, kind, span: self.lower_span(e.span) }
+            hir::Expr { hir_id: expr_hir_id, kind, span: self.lower_span(e.span) }
         })
     }
 
@@ -504,7 +519,6 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let if_expr = self.expr(span, if_kind);
         let block = self.block_expr(self.arena.alloc(if_expr));
         let span = self.lower_span(span.with_hi(cond.span.hi()));
-        let opt_label = self.lower_label(opt_label);
         hir::ExprKind::Loop(block, opt_label, hir::LoopSource::While, span)
     }
 
@@ -512,8 +526,9 @@ impl<'hir> LoweringContext<'_, 'hir> {
     /// `try { <stmts>; }` into `{ <stmts>; ::std::ops::Try::from_output(()) }`
     /// and save the block id to use it as a break target for desugaring of the `?` operator.
     fn lower_expr_try_block(&mut self, body: &Block) -> hir::ExprKind<'hir> {
-        self.with_catch_scope(body.id, |this| {
+        let body_hir_id = self.lower_node_id(body.id);
-            let mut block = this.lower_block_noalloc(body, true);
+        self.with_catch_scope(body_hir_id, |this| {
+            let mut block = this.lower_block_noalloc(body_hir_id, body, true);
 
             // Final expression of the block (if present) or `()` with span at the end of block
             let (try_span, tail_expr) = if let Some(expr) = block.expr.take() {
@@ -869,7 +884,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             let x_expr = self.expr_ident(gen_future_span, x_ident, x_pat_hid);
             let ready_field = self.single_pat_field(gen_future_span, x_pat);
             let ready_pat = self.pat_lang_item_variant(span, hir::LangItem::PollReady, ready_field);
-            let break_x = self.with_loop_scope(loop_node_id, move |this| {
+            let break_x = self.with_loop_scope(loop_hir_id, move |this| {
                 let expr_break =
                     hir::ExprKind::Break(this.lower_loop_destination(None), Some(x_expr));
                 this.arena.alloc(this.expr(gen_future_span, expr_break))
@@ -1101,8 +1116,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                         hir::CoroutineSource::Closure,
                     );
 
-                    let hir_id = this.lower_node_id(coroutine_kind.closure_id());
+                    this.maybe_forward_track_caller(body.span, closure_hir_id, expr.hir_id);
-                    this.maybe_forward_track_caller(body.span, closure_hir_id, hir_id);
 
                     (parameters, expr)
                 });
@@ -1465,8 +1479,16 @@ impl<'hir> LoweringContext<'_, 'hir> {
         )
     }
 
-    fn lower_label(&self, opt_label: Option<Label>) -> Option<Label> {
+    // Record labelled expr's HirId so that we can retrieve it in `lower_jump_destination` without
+    // lowering node id again.
+    fn lower_label(
+        &mut self,
+        opt_label: Option<Label>,
+        dest_id: NodeId,
+        dest_hir_id: hir::HirId,
+    ) -> Option<Label> {
         let label = opt_label?;
+        self.ident_and_label_to_local_id.insert(dest_id, dest_hir_id.local_id);
         Some(Label { ident: self.lower_ident(label.ident) })
     }
 
@@ -1474,17 +1496,20 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let target_id = match destination {
             Some((id, _)) => {
                 if let Some(loop_id) = self.resolver.get_label_res(id) {
-                    Ok(self.lower_node_id(loop_id))
+                    let local_id = self.ident_and_label_to_local_id[&loop_id];
+                    let loop_hir_id = HirId { owner: self.current_hir_id_owner, local_id };
+                    Ok(loop_hir_id)
                 } else {
                     Err(hir::LoopIdError::UnresolvedLabel)
                 }
             }
-            None => self
+            None => {
-                .loop_scope
+                self.loop_scope.map(|id| Ok(id)).unwrap_or(Err(hir::LoopIdError::OutsideLoopScope))
-                .map(|id| Ok(self.lower_node_id(id)))
+            }
-                .unwrap_or(Err(hir::LoopIdError::OutsideLoopScope)),
         };
-        let label = self.lower_label(destination.map(|(_, label)| label));
+        let label = destination
+            .map(|(_, label)| label)
+            .map(|label| Label { ident: self.lower_ident(label.ident) });
         hir::Destination { label, target_id }
     }
 
@@ -1499,14 +1524,14 @@ impl<'hir> LoweringContext<'_, 'hir> {
         }
     }
 
-    fn with_catch_scope<T>(&mut self, catch_id: NodeId, f: impl FnOnce(&mut Self) -> T) -> T {
+    fn with_catch_scope<T>(&mut self, catch_id: hir::HirId, f: impl FnOnce(&mut Self) -> T) -> T {
         let old_scope = self.catch_scope.replace(catch_id);
         let result = f(self);
         self.catch_scope = old_scope;
         result
     }
 
-    fn with_loop_scope<T>(&mut self, loop_id: NodeId, f: impl FnOnce(&mut Self) -> T) -> T {
+    fn with_loop_scope<T>(&mut self, loop_id: hir::HirId, f: impl FnOnce(&mut Self) -> T) -> T {
         // We're no longer in the base loop's condition; we're in another loop.
         let was_in_loop_condition = self.is_in_loop_condition;
         self.is_in_loop_condition = false;
@@ -1658,9 +1683,13 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let head_span = self.mark_span_with_reason(DesugaringKind::ForLoop, head.span, None);
         let pat_span = self.mark_span_with_reason(DesugaringKind::ForLoop, pat.span, None);
 
+        let loop_hir_id = self.lower_node_id(e.id);
+        let label = self.lower_label(opt_label, e.id, loop_hir_id);
+
         // `None => break`
         let none_arm = {
-            let break_expr = self.with_loop_scope(e.id, |this| this.expr_break_alloc(for_span));
+            let break_expr =
+                self.with_loop_scope(loop_hir_id, |this| this.expr_break_alloc(for_span));
             let pat = self.pat_none(for_span);
             self.arm(pat, break_expr)
         };
@@ -1668,7 +1697,8 @@ impl<'hir> LoweringContext<'_, 'hir> {
         // Some(<pat>) => <body>,
         let some_arm = {
             let some_pat = self.pat_some(pat_span, pat);
-            let body_block = self.with_loop_scope(e.id, |this| this.lower_block(body, false));
+            let body_block =
+                self.with_loop_scope(loop_hir_id, |this| this.lower_block(body, false));
             let body_expr = self.arena.alloc(self.expr_block(body_block));
             self.arm(some_pat, body_expr)
         };
@@ -1722,12 +1752,11 @@ impl<'hir> LoweringContext<'_, 'hir> {
         // `[opt_ident]: loop { ... }`
         let kind = hir::ExprKind::Loop(
             loop_block,
-            self.lower_label(opt_label),
+            label,
             hir::LoopSource::ForLoop,
             self.lower_span(for_span.with_hi(head.span.hi())),
         );
-        let loop_expr =
+        let loop_expr = self.arena.alloc(hir::Expr { hir_id: loop_hir_id, kind, span: for_span });
-            self.arena.alloc(hir::Expr { hir_id: self.lower_node_id(e.id), kind, span: for_span });
 
         // `mut iter => { ... }`
         let iter_arm = self.arm(iter_pat, loop_expr);
@@ -1867,8 +1896,8 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 self.arena.alloc(residual_expr),
                 unstable_span,
             );
-            let ret_expr = if let Some(catch_node) = self.catch_scope {
+            let ret_expr = if let Some(catch_id) = self.catch_scope {
-                let target_id = Ok(self.lower_node_id(catch_node));
+                let target_id = Ok(catch_id);
                 self.arena.alloc(self.expr(
                     try_span,
                     hir::ExprKind::Break(
@@ -1922,8 +1951,8 @@ impl<'hir> LoweringContext<'_, 'hir> {
             yeeted_span,
         );
 
-        if let Some(catch_node) = self.catch_scope {
+        if let Some(catch_id) = self.catch_scope {
-            let target_id = Ok(self.lower_node_id(catch_node));
+            let target_id = Ok(catch_id);
             hir::ExprKind::Break(hir::Destination { label: None, target_id }, Some(from_yeet_expr))
         } else {
             hir::ExprKind::Ret(Some(from_yeet_expr))

compiler/rustc_ast_lowering/src/item.rs

@@ -154,7 +154,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
     fn lower_item(&mut self, i: &Item) -> &'hir hir::Item<'hir> {
         let mut ident = i.ident;
         let vis_span = self.lower_span(i.vis.span);
-        let hir_id = self.lower_node_id(i.id);
+        let hir_id = hir::HirId::make_owner(self.current_hir_id_owner.def_id);
         let attrs = self.lower_attrs(hir_id, &i.attrs);
         let kind = self.lower_item_kind(i.span, i.id, hir_id, &mut ident, attrs, vis_span, &i.kind);
         let item = hir::Item {
@@ -604,7 +604,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
     }
 
     fn lower_foreign_item(&mut self, i: &ForeignItem) -> &'hir hir::ForeignItem<'hir> {
-        let hir_id = self.lower_node_id(i.id);
+        let hir_id = hir::HirId::make_owner(self.current_hir_id_owner.def_id);
         let owner_id = hir_id.expect_owner();
         self.lower_attrs(hir_id, &i.attrs);
         let item = hir::ForeignItem {
@@ -728,7 +728,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
     }
 
     fn lower_trait_item(&mut self, i: &AssocItem) -> &'hir hir::TraitItem<'hir> {
-        let hir_id = self.lower_node_id(i.id);
+        let hir_id = hir::HirId::make_owner(self.current_hir_id_owner.def_id);
         self.lower_attrs(hir_id, &i.attrs);
         let trait_item_def_id = hir_id.expect_owner();
 
@@ -858,7 +858,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         // Since `default impl` is not yet implemented, this is always true in impls.
         let has_value = true;
         let (defaultness, _) = self.lower_defaultness(i.kind.defaultness(), has_value);
-        let hir_id = self.lower_node_id(i.id);
+        let hir_id = hir::HirId::make_owner(self.current_hir_id_owner.def_id);
         self.lower_attrs(hir_id, &i.attrs);
 
         let (generics, kind) = match &i.kind {
@@ -1086,7 +1086,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             );
 
             // FIXME(async_fn_track_caller): Can this be moved above?
-            let hir_id = this.lower_node_id(coroutine_kind.closure_id());
+            let hir_id = expr.hir_id;
             this.maybe_forward_track_caller(body.span, fn_id, hir_id);
 
             (parameters, expr)

compiler/rustc_ast_lowering/src/lib.rs

@@ -40,8 +40,6 @@
 #![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
-use std::collections::hash_map::Entry;
-
 use rustc_ast::node_id::NodeMap;
 use rustc_ast::ptr::P;
 use rustc_ast::{self as ast, *};
@@ -115,8 +113,8 @@ struct LoweringContext<'a, 'hir> {
     /// outside of an `async fn`.
     current_item: Option<Span>,
 
-    catch_scope: Option<NodeId>,
+    catch_scope: Option<HirId>,
-    loop_scope: Option<NodeId>,
+    loop_scope: Option<HirId>,
     is_in_loop_condition: bool,
     is_in_trait_impl: bool,
     is_in_dyn_type: bool,
@@ -140,7 +138,10 @@ struct LoweringContext<'a, 'hir> {
     impl_trait_defs: Vec<hir::GenericParam<'hir>>,
     impl_trait_bounds: Vec<hir::WherePredicate<'hir>>,
 
-    /// NodeIds that are lowered inside the current HIR owner.
+    /// NodeIds of pattern identifiers and labelled nodes that are lowered inside the current HIR owner.
+    ident_and_label_to_local_id: NodeMap<hir::ItemLocalId>,
+    /// NodeIds that are lowered inside the current HIR owner. Only used for duplicate lowering check.
+    #[cfg(debug_assertions)]
     node_id_to_local_id: NodeMap<hir::ItemLocalId>,
 
     allow_try_trait: Lrc<[Symbol]>,
@@ -171,6 +172,8 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             current_hir_id_owner: hir::CRATE_OWNER_ID,
             current_def_id_parent: CRATE_DEF_ID,
             item_local_id_counter: hir::ItemLocalId::ZERO,
+            ident_and_label_to_local_id: Default::default(),
+            #[cfg(debug_assertions)]
             node_id_to_local_id: Default::default(),
             trait_map: Default::default(),
 
@@ -588,7 +591,11 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
 
         let current_attrs = std::mem::take(&mut self.attrs);
         let current_bodies = std::mem::take(&mut self.bodies);
-        let current_node_ids = std::mem::take(&mut self.node_id_to_local_id);
+        let current_ident_and_label_to_local_id =
+            std::mem::take(&mut self.ident_and_label_to_local_id);
+
+        #[cfg(debug_assertions)]
+        let current_node_id_to_local_id = std::mem::take(&mut self.node_id_to_local_id);
         let current_trait_map = std::mem::take(&mut self.trait_map);
         let current_owner =
             std::mem::replace(&mut self.current_hir_id_owner, hir::OwnerId { def_id });
@@ -602,8 +609,11 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         // and the caller to refer to some of the subdefinitions' nodes' `LocalDefId`s.
 
         // Always allocate the first `HirId` for the owner itself.
-        let _old = self.node_id_to_local_id.insert(owner, hir::ItemLocalId::ZERO);
+        #[cfg(debug_assertions)]
-        debug_assert_eq!(_old, None);
+        {
+            let _old = self.node_id_to_local_id.insert(owner, hir::ItemLocalId::ZERO);
+            debug_assert_eq!(_old, None);
+        }
 
         let item = self.with_def_id_parent(def_id, f);
         debug_assert_eq!(def_id, item.def_id().def_id);
@@ -614,7 +624,12 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
 
         self.attrs = current_attrs;
         self.bodies = current_bodies;
-        self.node_id_to_local_id = current_node_ids;
+        self.ident_and_label_to_local_id = current_ident_and_label_to_local_id;
+
+        #[cfg(debug_assertions)]
+        {
+            self.node_id_to_local_id = current_node_id_to_local_id;
+        }
         self.trait_map = current_trait_map;
         self.current_hir_id_owner = current_owner;
         self.item_local_id_counter = current_local_counter;
@@ -680,39 +695,37 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         self.arena.alloc(hir::OwnerInfo { nodes, parenting, attrs, trait_map })
     }
 
-    /// This method allocates a new `HirId` for the given `NodeId` and stores it in
+    /// This method allocates a new `HirId` for the given `NodeId`.
-    /// the `LoweringContext`'s `NodeId => HirId` map.
     /// Take care not to call this method if the resulting `HirId` is then not
     /// actually used in the HIR, as that would trigger an assertion in the
     /// `HirIdValidator` later on, which makes sure that all `NodeId`s got mapped
-    /// properly. Calling the method twice with the same `NodeId` is fine though.
+    /// properly. Calling the method twice with the same `NodeId` is also forbidden.
     #[instrument(level = "debug", skip(self), ret)]
     fn lower_node_id(&mut self, ast_node_id: NodeId) -> HirId {
         assert_ne!(ast_node_id, DUMMY_NODE_ID);
 
-        match self.node_id_to_local_id.entry(ast_node_id) {
+        let owner = self.current_hir_id_owner;
-            Entry::Occupied(o) => HirId { owner: self.current_hir_id_owner, local_id: *o.get() },
+        let local_id = self.item_local_id_counter;
-            Entry::Vacant(v) => {
+        assert_ne!(local_id, hir::ItemLocalId::ZERO);
-                // Generate a new `HirId`.
+        self.item_local_id_counter.increment_by(1);
-                let owner = self.current_hir_id_owner;
+        let hir_id = HirId { owner, local_id };
-                let local_id = self.item_local_id_counter;
-                let hir_id = HirId { owner, local_id };
 
-                v.insert(local_id);
+        if let Some(def_id) = self.opt_local_def_id(ast_node_id) {
-                self.item_local_id_counter.increment_by(1);
+            self.children.push((def_id, hir::MaybeOwner::NonOwner(hir_id)));
-
-                assert_ne!(local_id, hir::ItemLocalId::ZERO);
-                if let Some(def_id) = self.opt_local_def_id(ast_node_id) {
-                    self.children.push((def_id, hir::MaybeOwner::NonOwner(hir_id)));
-                }
-
-                if let Some(traits) = self.resolver.trait_map.remove(&ast_node_id) {
-                    self.trait_map.insert(hir_id.local_id, traits.into_boxed_slice());
-                }
-
-                hir_id
-            }
         }
+
+        if let Some(traits) = self.resolver.trait_map.remove(&ast_node_id) {
+            self.trait_map.insert(hir_id.local_id, traits.into_boxed_slice());
+        }
+
+        // Check whether the same `NodeId` is lowered more than once.
+        #[cfg(debug_assertions)]
+        {
+            let old = self.node_id_to_local_id.insert(ast_node_id, local_id);
+            assert_eq!(old, None);
+        }
+
+        hir_id
     }
 
     /// Generate a new `HirId` without a backing `NodeId`.
@@ -729,7 +742,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
     fn lower_res(&mut self, res: Res<NodeId>) -> Res {
         let res: Result<Res, ()> = res.apply_id(|id| {
             let owner = self.current_hir_id_owner;
-            let local_id = self.node_id_to_local_id.get(&id).copied().ok_or(())?;
+            let local_id = self.ident_and_label_to_local_id.get(&id).copied().ok_or(())?;
             Ok(HirId { owner, local_id })
         });
         trace!(?res);

compiler/rustc_ast_lowering/src/pat.rs

@@ -21,13 +21,20 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
     fn lower_pat_mut(&mut self, mut pattern: &Pat) -> hir::Pat<'hir> {
         ensure_sufficient_stack(|| {
             // loop here to avoid recursion
+            let pat_hir_id = self.lower_node_id(pattern.id);
             let node = loop {
                 match &pattern.kind {
                     PatKind::Wild => break hir::PatKind::Wild,
                     PatKind::Never => break hir::PatKind::Never,
                     PatKind::Ident(binding_mode, ident, sub) => {
                         let lower_sub = |this: &mut Self| sub.as_ref().map(|s| this.lower_pat(s));
-                        break self.lower_pat_ident(pattern, *binding_mode, *ident, lower_sub);
+                        break self.lower_pat_ident(
+                            pattern,
+                            *binding_mode,
+                            *ident,
+                            pat_hir_id,
+                            lower_sub,
+                        );
                     }
                     PatKind::Lit(e) => {
                         break hir::PatKind::Lit(self.lower_expr_within_pat(e, false));
@@ -119,7 +126,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                 }
             };
 
-            self.pat_with_node_id_of(pattern, node)
+            self.pat_with_node_id_of(pattern, node, pat_hir_id)
         })
     }
 
@@ -187,10 +194,12 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         let mut prev_rest_span = None;
 
         // Lowers `$bm $ident @ ..` to `$bm $ident @ _`.
-        let lower_rest_sub = |this: &mut Self, pat, &ann, &ident, sub| {
+        let lower_rest_sub = |this: &mut Self, pat: &Pat, &ann, &ident, sub: &Pat| {
-            let lower_sub = |this: &mut Self| Some(this.pat_wild_with_node_id_of(sub));
+            let sub_hir_id = this.lower_node_id(sub.id);
-            let node = this.lower_pat_ident(pat, ann, ident, lower_sub);
+            let lower_sub = |this: &mut Self| Some(this.pat_wild_with_node_id_of(sub, sub_hir_id));
-            this.pat_with_node_id_of(pat, node)
+            let pat_hir_id = this.lower_node_id(pat.id);
+            let node = this.lower_pat_ident(pat, ann, ident, pat_hir_id, lower_sub);
+            this.pat_with_node_id_of(pat, node, pat_hir_id)
         };
 
         let mut iter = pats.iter();
@@ -200,7 +209,8 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                 // Found a sub-slice pattern `..`. Record, lower it to `_`, and stop here.
                 PatKind::Rest => {
                     prev_rest_span = Some(pat.span);
-                    slice = Some(self.pat_wild_with_node_id_of(pat));
+                    let hir_id = self.lower_node_id(pat.id);
+                    slice = Some(self.pat_wild_with_node_id_of(pat, hir_id));
                     break;
                 }
                 // Found a sub-slice pattern `$binding_mode $ident @ ..`.
@@ -248,19 +258,35 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         p: &Pat,
         annotation: BindingMode,
         ident: Ident,
+        hir_id: hir::HirId,
         lower_sub: impl FnOnce(&mut Self) -> Option<&'hir hir::Pat<'hir>>,
     ) -> hir::PatKind<'hir> {
         match self.resolver.get_partial_res(p.id).map(|d| d.expect_full_res()) {
             // `None` can occur in body-less function signatures
             res @ (None | Some(Res::Local(_))) => {
-                let canonical_id = match res {
+                let binding_id = match res {
-                    Some(Res::Local(id)) => id,
+                    Some(Res::Local(id)) => {
-                    _ => p.id,
+                        // In `Or` patterns like `VariantA(s) | VariantB(s, _)`, multiple identifier patterns
+                        // will be resolved to the same `Res::Local`. Thus they just share a single
+                        // `HirId`.
+                        if id == p.id {
+                            self.ident_and_label_to_local_id.insert(id, hir_id.local_id);
+                            hir_id
+                        } else {
+                            hir::HirId {
+                                owner: self.current_hir_id_owner,
+                                local_id: self.ident_and_label_to_local_id[&id],
+                            }
+                        }
+                    }
+                    _ => {
+                        self.ident_and_label_to_local_id.insert(p.id, hir_id.local_id);
+                        hir_id
+                    }
                 };
-
                 hir::PatKind::Binding(
                     annotation,
-                    self.lower_node_id(canonical_id),
+                    binding_id,
                     self.lower_ident(ident),
                     lower_sub(self),
                 )
@@ -280,18 +306,18 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         }
     }
 
-    fn pat_wild_with_node_id_of(&mut self, p: &Pat) -> &'hir hir::Pat<'hir> {
+    fn pat_wild_with_node_id_of(&mut self, p: &Pat, hir_id: hir::HirId) -> &'hir hir::Pat<'hir> {
-        self.arena.alloc(self.pat_with_node_id_of(p, hir::PatKind::Wild))
+        self.arena.alloc(self.pat_with_node_id_of(p, hir::PatKind::Wild, hir_id))
     }
 
-    /// Construct a `Pat` with the `HirId` of `p.id` lowered.
+    /// Construct a `Pat` with the `HirId` of `p.id` already lowered.
-    fn pat_with_node_id_of(&mut self, p: &Pat, kind: hir::PatKind<'hir>) -> hir::Pat<'hir> {
+    fn pat_with_node_id_of(
-        hir::Pat {
+        &mut self,
-            hir_id: self.lower_node_id(p.id),
+        p: &Pat,
-            kind,
+        kind: hir::PatKind<'hir>,
-            span: self.lower_span(p.span),
+        hir_id: hir::HirId,
-            default_binding_modes: true,
+    ) -> hir::Pat<'hir> {
-        }
+        hir::Pat { hir_id, kind, span: self.lower_span(p.span), default_binding_modes: true }
     }
 
     /// Emit a friendly error for extra `..` patterns in a tuple/tuple struct/slice pattern.

compiler/rustc_codegen_llvm/src/abi.rs

@@ -415,7 +415,7 @@ impl<'ll, 'tcx> FnAbiLlvmExt<'ll, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
         instance: Option<ty::Instance<'tcx>>,
     ) {
         let mut func_attrs = SmallVec::<[_; 3]>::new();
-        if self.ret.layout.abi.is_uninhabited() {
+        if self.ret.layout.is_uninhabited() {
             func_attrs.push(llvm::AttributeKind::NoReturn.create_attr(cx.llcx));
         }
         if !self.can_unwind {
@@ -532,7 +532,7 @@ impl<'ll, 'tcx> FnAbiLlvmExt<'ll, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
 
     fn apply_attrs_callsite(&self, bx: &mut Builder<'_, 'll, 'tcx>, callsite: &'ll Value) {
         let mut func_attrs = SmallVec::<[_; 2]>::new();
-        if self.ret.layout.abi.is_uninhabited() {
+        if self.ret.layout.is_uninhabited() {
             func_attrs.push(llvm::AttributeKind::NoReturn.create_attr(bx.cx.llcx));
         }
         if !self.can_unwind {

compiler/rustc_codegen_llvm/src/allocator.rs

@@ -7,6 +7,7 @@ use rustc_middle::bug;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::config::{DebugInfo, OomStrategy};
 
+use crate::common::AsCCharPtr;
 use crate::llvm::{self, Context, False, Module, True, Type};
 use crate::{ModuleLlvm, attributes, debuginfo};
 
@@ -76,14 +77,14 @@ pub(crate) unsafe fn codegen(
     unsafe {
         // __rust_alloc_error_handler_should_panic
         let name = OomStrategy::SYMBOL;
-        let ll_g = llvm::LLVMRustGetOrInsertGlobal(llmod, name.as_ptr().cast(), name.len(), i8);
+        let ll_g = llvm::LLVMRustGetOrInsertGlobal(llmod, name.as_c_char_ptr(), name.len(), i8);
         llvm::set_visibility(ll_g, llvm::Visibility::from_generic(tcx.sess.default_visibility()));
         let val = tcx.sess.opts.unstable_opts.oom.should_panic();
         let llval = llvm::LLVMConstInt(i8, val as u64, False);
         llvm::LLVMSetInitializer(ll_g, llval);
 
         let name = NO_ALLOC_SHIM_IS_UNSTABLE;
-        let ll_g = llvm::LLVMRustGetOrInsertGlobal(llmod, name.as_ptr().cast(), name.len(), i8);
+        let ll_g = llvm::LLVMRustGetOrInsertGlobal(llmod, name.as_c_char_ptr(), name.len(), i8);
         llvm::set_visibility(ll_g, llvm::Visibility::from_generic(tcx.sess.default_visibility()));
         let llval = llvm::LLVMConstInt(i8, 0, False);
         llvm::LLVMSetInitializer(ll_g, llval);
@@ -115,7 +116,7 @@ fn create_wrapper_function(
         );
         let llfn = llvm::LLVMRustGetOrInsertFunction(
             llmod,
-            from_name.as_ptr().cast(),
+            from_name.as_c_char_ptr(),
             from_name.len(),
             ty,
         );
@@ -137,7 +138,7 @@ fn create_wrapper_function(
         }
 
         let callee =
-            llvm::LLVMRustGetOrInsertFunction(llmod, to_name.as_ptr().cast(), to_name.len(), ty);
+            llvm::LLVMRustGetOrInsertFunction(llmod, to_name.as_c_char_ptr(), to_name.len(), ty);
         if let Some(no_return) = no_return {
             // -> ! DIFlagNoReturn
             attributes::apply_to_llfn(callee, llvm::AttributePlace::Function, &[no_return]);

compiler/rustc_codegen_llvm/src/asm.rs

@@ -15,7 +15,7 @@ use smallvec::SmallVec;
 use tracing::debug;
 
 use crate::builder::Builder;
-use crate::common::Funclet;
+use crate::common::{AsCCharPtr, Funclet};
 use crate::context::CodegenCx;
 use crate::type_::Type;
 use crate::type_of::LayoutLlvmExt;
@@ -420,7 +420,7 @@ impl<'tcx> AsmCodegenMethods<'tcx> for CodegenCx<'_, 'tcx> {
         unsafe {
             llvm::LLVMAppendModuleInlineAsm(
                 self.llmod,
-                template_str.as_ptr().cast(),
+                template_str.as_c_char_ptr(),
                 template_str.len(),
             );
         }
@@ -458,14 +458,14 @@ pub(crate) fn inline_asm_call<'ll>(
     let fty = bx.cx.type_func(&argtys, output);
     unsafe {
         // Ask LLVM to verify that the constraints are well-formed.
-        let constraints_ok = llvm::LLVMRustInlineAsmVerify(fty, cons.as_ptr().cast(), cons.len());
+        let constraints_ok = llvm::LLVMRustInlineAsmVerify(fty, cons.as_c_char_ptr(), cons.len());
         debug!("constraint verification result: {:?}", constraints_ok);
         if constraints_ok {
             let v = llvm::LLVMRustInlineAsm(
                 fty,
-                asm.as_ptr().cast(),
+                asm.as_c_char_ptr(),
                 asm.len(),
-                cons.as_ptr().cast(),
+                cons.as_c_char_ptr(),
                 cons.len(),
                 volatile,
                 alignstack,

compiler/rustc_codegen_llvm/src/back/lto.rs

@@ -25,6 +25,7 @@ use tracing::{debug, info};
 use crate::back::write::{
     self, CodegenDiagnosticsStage, DiagnosticHandlers, bitcode_section_name, save_temp_bitcode,
 };
+use crate::common::AsCCharPtr;
 use crate::errors::{
     DynamicLinkingWithLTO, LlvmError, LtoBitcodeFromRlib, LtoDisallowed, LtoDylib, LtoProcMacro,
 };
@@ -604,7 +605,7 @@ pub(crate) fn run_pass_manager(
     unsafe {
         if !llvm::LLVMRustHasModuleFlag(
             module.module_llvm.llmod(),
-            "LTOPostLink".as_ptr().cast(),
+            "LTOPostLink".as_c_char_ptr(),
             11,
         ) {
             llvm::LLVMRustAddModuleFlagU32(

compiler/rustc_codegen_llvm/src/back/write.rs

@@ -34,6 +34,7 @@ use crate::back::owned_target_machine::OwnedTargetMachine;
 use crate::back::profiling::{
     LlvmSelfProfiler, selfprofile_after_pass_callback, selfprofile_before_pass_callback,
 };
+use crate::common::AsCCharPtr;
 use crate::errors::{
     CopyBitcode, FromLlvmDiag, FromLlvmOptimizationDiag, LlvmError, UnknownCompression,
     WithLlvmError, WriteBytecode,
@@ -596,9 +597,9 @@ pub(crate) unsafe fn llvm_optimize(
             llvm_selfprofiler,
             selfprofile_before_pass_callback,
             selfprofile_after_pass_callback,
-            extra_passes.as_ptr().cast(),
+            extra_passes.as_c_char_ptr(),
             extra_passes.len(),
-            llvm_plugins.as_ptr().cast(),
+            llvm_plugins.as_c_char_ptr(),
             llvm_plugins.len(),
         )
     };
@@ -1042,7 +1043,7 @@ unsafe fn embed_bitcode(
             llvm::LLVMSetInitializer(llglobal, llconst);
 
             let section = bitcode_section_name(cgcx);
-            llvm::LLVMSetSection(llglobal, section.as_ptr().cast());
+            llvm::LLVMSetSection(llglobal, section.as_c_char_ptr());
             llvm::set_linkage(llglobal, llvm::Linkage::PrivateLinkage);
             llvm::LLVMSetGlobalConstant(llglobal, llvm::True);
 
@@ -1066,9 +1067,9 @@ unsafe fn embed_bitcode(
             // We need custom section flags, so emit module-level inline assembly.
             let section_flags = if cgcx.is_pe_coff { "n" } else { "e" };
             let asm = create_section_with_flags_asm(".llvmbc", section_flags, bitcode);
-            llvm::LLVMAppendModuleInlineAsm(llmod, asm.as_ptr().cast(), asm.len());
+            llvm::LLVMAppendModuleInlineAsm(llmod, asm.as_c_char_ptr(), asm.len());
             let asm = create_section_with_flags_asm(".llvmcmd", section_flags, cmdline.as_bytes());
-            llvm::LLVMAppendModuleInlineAsm(llmod, asm.as_ptr().cast(), asm.len());
+            llvm::LLVMAppendModuleInlineAsm(llmod, asm.as_c_char_ptr(), asm.len());
         }
     }
 }

compiler/rustc_codegen_llvm/src/common.rs

@@ -392,3 +392,21 @@ pub(crate) fn get_dllimport<'tcx>(
     tcx.native_library(id)
         .and_then(|lib| lib.dll_imports.iter().find(|di| di.name.as_str() == name))
 }
+
+/// Extension trait for explicit casts to `*const c_char`.
+pub(crate) trait AsCCharPtr {
+    /// Equivalent to `self.as_ptr().cast()`, but only casts to `*const c_char`.
+    fn as_c_char_ptr(&self) -> *const c_char;
+}
+
+impl AsCCharPtr for str {
+    fn as_c_char_ptr(&self) -> *const c_char {
+        self.as_ptr().cast()
+    }
+}
+
+impl AsCCharPtr for [u8] {
+    fn as_c_char_ptr(&self) -> *const c_char {
+        self.as_ptr().cast()
+    }
+}

compiler/rustc_codegen_llvm/src/consts.rs

@@ -19,7 +19,7 @@ use rustc_target::abi::{
 };
 use tracing::{debug, instrument, trace};
 
-use crate::common::CodegenCx;
+use crate::common::{AsCCharPtr, CodegenCx};
 use crate::errors::{
     InvalidMinimumAlignmentNotPowerOfTwo, InvalidMinimumAlignmentTooLarge, SymbolAlreadyDefined,
 };
@@ -400,7 +400,7 @@ impl<'ll> CodegenCx<'ll, '_> {
 
                 let new_g = llvm::LLVMRustGetOrInsertGlobal(
                     self.llmod,
-                    name.as_ptr().cast(),
+                    name.as_c_char_ptr(),
                     name.len(),
                     val_llty,
                 );
@@ -451,7 +451,7 @@ impl<'ll> CodegenCx<'ll, '_> {
                 if let Some(section) = attrs.link_section {
                     let section = llvm::LLVMMDStringInContext2(
                         self.llcx,
-                        section.as_str().as_ptr().cast(),
+                        section.as_str().as_c_char_ptr(),
                         section.as_str().len(),
                     );
                     assert!(alloc.provenance().ptrs().is_empty());
@@ -462,7 +462,7 @@ impl<'ll> CodegenCx<'ll, '_> {
                     let bytes =
                         alloc.inspect_with_uninit_and_ptr_outside_interpreter(0..alloc.len());
                     let alloc =
-                        llvm::LLVMMDStringInContext2(self.llcx, bytes.as_ptr().cast(), bytes.len());
+                        llvm::LLVMMDStringInContext2(self.llcx, bytes.as_c_char_ptr(), bytes.len());
                     let data = [section, alloc];
                     let meta = llvm::LLVMMDNodeInContext2(self.llcx, data.as_ptr(), data.len());
                     let val = llvm::LLVMMetadataAsValue(self.llcx, meta);

compiler/rustc_codegen_llvm/src/context.rs

@@ -29,6 +29,7 @@ use smallvec::SmallVec;
 
 use crate::back::write::to_llvm_code_model;
 use crate::callee::get_fn;
+use crate::common::AsCCharPtr;
 use crate::debuginfo::metadata::apply_vcall_visibility_metadata;
 use crate::llvm::{Metadata, MetadataType};
 use crate::type_::Type;
@@ -231,7 +232,7 @@ pub(crate) unsafe fn create_module<'ll>(
     // If we're normalizing integers with CFI, ensure LLVM generated functions do the same.
     // See https://github.com/llvm/llvm-project/pull/104826
     if sess.is_sanitizer_cfi_normalize_integers_enabled() {
-        let cfi_normalize_integers = c"cfi-normalize-integers".as_ptr().cast();
+        let cfi_normalize_integers = c"cfi-normalize-integers".as_ptr();
         unsafe {
             llvm::LLVMRustAddModuleFlagU32(
                 llmod,
@@ -268,7 +269,7 @@ pub(crate) unsafe fn create_module<'ll>(
         let pfe =
             PatchableFunctionEntry::from_config(sess.opts.unstable_opts.patchable_function_entry);
         if pfe.prefix() > 0 {
-            let kcfi_offset = c"kcfi-offset".as_ptr().cast();
+            let kcfi_offset = c"kcfi-offset".as_ptr();
             unsafe {
                 llvm::LLVMRustAddModuleFlagU32(
                     llmod,
@@ -429,7 +430,7 @@ pub(crate) unsafe fn create_module<'ll>(
     let name_metadata = unsafe {
         llvm::LLVMMDStringInContext2(
             llcx,
-            rustc_producer.as_ptr().cast(),
+            rustc_producer.as_c_char_ptr(),
             rustc_producer.as_bytes().len(),
         )
     };
@@ -453,7 +454,7 @@ pub(crate) unsafe fn create_module<'ll>(
                 llmod,
                 llvm::LLVMModFlagBehavior::Error,
                 c"target-abi".as_ptr(),
-                llvm_abiname.as_ptr().cast(),
+                llvm_abiname.as_c_char_ptr(),
                 llvm_abiname.len(),
             );
         }
@@ -474,7 +475,7 @@ pub(crate) unsafe fn create_module<'ll>(
             // We already checked this during option parsing
             _ => unreachable!(),
         };
-        unsafe { llvm::LLVMRustAddModuleFlagU32(llmod, behavior, key.as_ptr().cast(), *value) }
+        unsafe { llvm::LLVMRustAddModuleFlagU32(llmod, behavior, key.as_c_char_ptr(), *value) }
     }
 
     llmod

compiler/rustc_codegen_llvm/src/coverageinfo/mod.rs

@@ -14,7 +14,7 @@ use rustc_target::abi::Size;
 use tracing::{debug, instrument};
 
 use crate::builder::Builder;
-use crate::common::CodegenCx;
+use crate::common::{AsCCharPtr, CodegenCx};
 use crate::coverageinfo::map_data::FunctionCoverageCollector;
 use crate::llvm;
 
@@ -236,7 +236,7 @@ fn create_pgo_func_name_var<'ll, 'tcx>(
     unsafe {
         llvm::LLVMRustCoverageCreatePGOFuncNameVar(
             llfn,
-            mangled_fn_name.as_ptr().cast(),
+            mangled_fn_name.as_c_char_ptr(),
             mangled_fn_name.len(),
         )
     }
@@ -248,7 +248,7 @@ pub(crate) fn write_filenames_section_to_buffer<'a>(
 ) {
     let (pointers, lengths) = filenames
         .into_iter()
-        .map(|s: &str| (s.as_ptr().cast(), s.len()))
+        .map(|s: &str| (s.as_c_char_ptr(), s.len()))
         .unzip::<_, _, Vec<_>, Vec<_>>();
 
     unsafe {
@@ -291,7 +291,7 @@ pub(crate) fn write_mapping_to_buffer(
 }
 
 pub(crate) fn hash_bytes(bytes: &[u8]) -> u64 {
-    unsafe { llvm::LLVMRustCoverageHashByteArray(bytes.as_ptr().cast(), bytes.len()) }
+    unsafe { llvm::LLVMRustCoverageHashByteArray(bytes.as_c_char_ptr(), bytes.len()) }
 }
 
 pub(crate) fn mapping_version() -> u32 {

compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs

@@ -32,7 +32,7 @@ use super::type_names::{compute_debuginfo_type_name, compute_debuginfo_vtable_na
 use super::utils::{
     DIB, create_DIArray, debug_context, get_namespace_for_item, is_node_local_to_unit,
 };
-use crate::common::CodegenCx;
+use crate::common::{AsCCharPtr, CodegenCx};
 use crate::debuginfo::metadata::type_map::build_type_with_children;
 use crate::debuginfo::utils::{WidePtrKind, wide_pointer_kind};
 use crate::llvm::debuginfo::{
@@ -190,7 +190,7 @@ fn build_pointer_or_reference_di_node<'ll, 'tcx>(
                     data_layout.pointer_size.bits(),
                     data_layout.pointer_align.abi.bits() as u32,
                     0, // Ignore DWARF address space.
-                    ptr_type_debuginfo_name.as_ptr().cast(),
+                    ptr_type_debuginfo_name.as_c_char_ptr(),
                     ptr_type_debuginfo_name.len(),
                 )
             };
@@ -348,7 +348,7 @@ fn build_subroutine_type_di_node<'ll, 'tcx>(
             size,
             align,
             0, // Ignore DWARF address space.
-            name.as_ptr().cast(),
+            name.as_c_char_ptr(),
             name.len(),
         )
     };
@@ -518,7 +518,7 @@ fn recursion_marker_type_di_node<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>) -> &'ll D
             let name = "<recur_type>";
             llvm::LLVMRustDIBuilderCreateBasicType(
                 DIB(cx),
-                name.as_ptr().cast(),
+                name.as_c_char_ptr(),
                 name.len(),
                 cx.tcx.data_layout.pointer_size.bits(),
                 DW_ATE_unsigned,
@@ -640,14 +640,14 @@ pub(crate) fn file_metadata<'ll>(cx: &CodegenCx<'ll, '_>, source_file: &SourceFi
         unsafe {
             llvm::LLVMRustDIBuilderCreateFile(
                 DIB(cx),
-                file_name.as_ptr().cast(),
+                file_name.as_c_char_ptr(),
                 file_name.len(),
-                directory.as_ptr().cast(),
+                directory.as_c_char_ptr(),
                 directory.len(),
                 hash_kind,
-                hash_value.as_ptr().cast(),
+                hash_value.as_c_char_ptr(),
                 hash_value.len(),
-                source.map_or(ptr::null(), |x| x.as_ptr().cast()),
+                source.map_or(ptr::null(), |x| x.as_c_char_ptr()),
                 source.map_or(0, |x| x.len()),
             )
         }
@@ -662,12 +662,12 @@ fn unknown_file_metadata<'ll>(cx: &CodegenCx<'ll, '_>) -> &'ll DIFile {
 
         llvm::LLVMRustDIBuilderCreateFile(
             DIB(cx),
-            file_name.as_ptr().cast(),
+            file_name.as_c_char_ptr(),
             file_name.len(),
-            directory.as_ptr().cast(),
+            directory.as_c_char_ptr(),
             directory.len(),
             llvm::ChecksumKind::None,
-            hash_value.as_ptr().cast(),
+            hash_value.as_c_char_ptr(),
             hash_value.len(),
             ptr::null(),
             0,
@@ -788,7 +788,7 @@ fn build_basic_type_di_node<'ll, 'tcx>(
     let ty_di_node = unsafe {
         llvm::LLVMRustDIBuilderCreateBasicType(
             DIB(cx),
-            name.as_ptr().cast(),
+            name.as_c_char_ptr(),
             name.len(),
             cx.size_of(t).bits(),
             encoding,
@@ -810,7 +810,7 @@ fn build_basic_type_di_node<'ll, 'tcx>(
         llvm::LLVMRustDIBuilderCreateTypedef(
             DIB(cx),
             ty_di_node,
-            typedef_name.as_ptr().cast(),
+            typedef_name.as_c_char_ptr(),
             typedef_name.len(),
             unknown_file_metadata(cx),
             0,
@@ -861,7 +861,7 @@ fn build_param_type_di_node<'ll, 'tcx>(
         di_node: unsafe {
             llvm::LLVMRustDIBuilderCreateBasicType(
                 DIB(cx),
-                name.as_ptr().cast(),
+                name.as_c_char_ptr(),
                 name.len(),
                 Size::ZERO.bits(),
                 DW_ATE_unsigned,
@@ -948,9 +948,9 @@ pub(crate) fn build_compile_unit_di_node<'ll, 'tcx>(
     unsafe {
         let compile_unit_file = llvm::LLVMRustDIBuilderCreateFile(
             debug_context.builder,
-            name_in_debuginfo.as_ptr().cast(),
+            name_in_debuginfo.as_c_char_ptr(),
             name_in_debuginfo.len(),
-            work_dir.as_ptr().cast(),
+            work_dir.as_c_char_ptr(),
             work_dir.len(),
             llvm::ChecksumKind::None,
             ptr::null(),
@@ -963,7 +963,7 @@ pub(crate) fn build_compile_unit_di_node<'ll, 'tcx>(
             debug_context.builder,
             DW_LANG_RUST,
             compile_unit_file,
-            producer.as_ptr().cast(),
+            producer.as_c_char_ptr(),
             producer.len(),
             tcx.sess.opts.optimize != config::OptLevel::No,
             c"".as_ptr(),
@@ -971,7 +971,7 @@ pub(crate) fn build_compile_unit_di_node<'ll, 'tcx>(
             // NB: this doesn't actually have any perceptible effect, it seems. LLVM will instead
             // put the path supplied to `MCSplitDwarfFile` into the debug info of the final
             // output(s).
-            split_name.as_ptr().cast(),
+            split_name.as_c_char_ptr(),
             split_name.len(),
             kind,
             0,
@@ -1022,7 +1022,7 @@ fn build_field_di_node<'ll, 'tcx>(
         llvm::LLVMRustDIBuilderCreateMemberType(
             DIB(cx),
             owner,
-            name.as_ptr().cast(),
+            name.as_c_char_ptr(),
             name.len(),
             unknown_file_metadata(cx),
             UNKNOWN_LINE_NUMBER,
@@ -1306,7 +1306,7 @@ fn build_generic_type_param_di_nodes<'ll, 'tcx>(
                             llvm::LLVMRustDIBuilderCreateTemplateTypeParameter(
                                 DIB(cx),
                                 None,
-                                name.as_ptr().cast(),
+                                name.as_c_char_ptr(),
                                 name.len(),
                                 actual_type_di_node,
                             )
@@ -1382,9 +1382,9 @@ pub(crate) fn build_global_var_di_node<'ll>(
         llvm::LLVMRustDIBuilderCreateStaticVariable(
             DIB(cx),
             Some(var_scope),
-            var_name.as_ptr().cast(),
+            var_name.as_c_char_ptr(),
             var_name.len(),
-            linkage_name.as_ptr().cast(),
+            linkage_name.as_c_char_ptr(),
             linkage_name.len(),
             file_metadata,
             line_number,
@@ -1602,9 +1602,9 @@ pub(crate) fn create_vtable_di_node<'ll, 'tcx>(
         llvm::LLVMRustDIBuilderCreateStaticVariable(
             DIB(cx),
             NO_SCOPE_METADATA,
-            vtable_name.as_ptr().cast(),
+            vtable_name.as_c_char_ptr(),
             vtable_name.len(),
-            linkage_name.as_ptr().cast(),
+            linkage_name.as_c_char_ptr(),
             linkage_name.len(),
             unknown_file_metadata(cx),
             UNKNOWN_LINE_NUMBER,

compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/cpp_like.rs

@@ -11,7 +11,7 @@ use rustc_middle::ty::{self, AdtDef, CoroutineArgs, CoroutineArgsExt, Ty};
 use rustc_target::abi::{Align, Endian, Size, TagEncoding, VariantIdx, Variants};
 use smallvec::smallvec;
 
-use crate::common::CodegenCx;
+use crate::common::{AsCCharPtr, CodegenCx};
 use crate::debuginfo::metadata::enums::DiscrResult;
 use crate::debuginfo::metadata::type_map::{self, Stub, UniqueTypeId};
 use crate::debuginfo::metadata::{
@@ -359,7 +359,7 @@ fn build_single_variant_union_fields<'ll, 'tcx>(
             llvm::LLVMRustDIBuilderCreateStaticMemberType(
                 DIB(cx),
                 enum_type_di_node,
-                TAG_FIELD_NAME.as_ptr().cast(),
+                TAG_FIELD_NAME.as_c_char_ptr(),
                 TAG_FIELD_NAME.len(),
                 unknown_file_metadata(cx),
                 UNKNOWN_LINE_NUMBER,
@@ -537,7 +537,7 @@ fn build_variant_struct_wrapper_type_di_node<'ll, 'tcx>(
                     llvm::LLVMRustDIBuilderCreateStaticMemberType(
                         DIB(cx),
                         wrapper_struct_type_di_node,
-                        name.as_ptr().cast(),
+                        name.as_c_char_ptr(),
                         name.len(),
                         unknown_file_metadata(cx),
                         UNKNOWN_LINE_NUMBER,
@@ -785,7 +785,7 @@ fn build_union_fields_for_direct_tag_enum_or_coroutine<'ll, 'tcx>(
             llvm::LLVMRustDIBuilderCreateMemberType(
                 DIB(cx),
                 enum_type_di_node,
-                field_name.as_ptr().cast(),
+                field_name.as_c_char_ptr(),
                 field_name.len(),
                 file_di_node,
                 line_number,

compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs

@@ -13,7 +13,7 @@ use rustc_target::abi::{FieldIdx, TagEncoding, VariantIdx, Variants};
 
 use super::type_map::{DINodeCreationResult, UniqueTypeId};
 use super::{SmallVec, size_and_align_of};
-use crate::common::CodegenCx;
+use crate::common::{AsCCharPtr, CodegenCx};
 use crate::debuginfo::metadata::type_map::{self, Stub};
 use crate::debuginfo::metadata::{
     UNKNOWN_LINE_NUMBER, build_field_di_node, build_generic_type_param_di_nodes, type_di_node,
@@ -106,7 +106,7 @@ fn build_enumeration_type_di_node<'ll, 'tcx>(
             let value = [value as u64, (value >> 64) as u64];
             Some(llvm::LLVMRustDIBuilderCreateEnumerator(
                 DIB(cx),
-                name.as_ptr().cast(),
+                name.as_c_char_ptr(),
                 name.len(),
                 value.as_ptr(),
                 size.bits() as libc::c_uint,
@@ -119,7 +119,7 @@ fn build_enumeration_type_di_node<'ll, 'tcx>(
         llvm::LLVMRustDIBuilderCreateEnumerationType(
             DIB(cx),
             containing_scope,
-            type_name.as_ptr().cast(),
+            type_name.as_c_char_ptr(),
             type_name.len(),
             unknown_file_metadata(cx),
             UNKNOWN_LINE_NUMBER,

compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/native.rs

@@ -10,7 +10,7 @@ use rustc_middle::ty::{self};
 use rustc_target::abi::{Size, TagEncoding, VariantIdx, Variants};
 use smallvec::smallvec;
 
-use crate::common::CodegenCx;
+use crate::common::{AsCCharPtr, CodegenCx};
 use crate::debuginfo::metadata::type_map::{self, Stub, StubInfo, UniqueTypeId};
 use crate::debuginfo::metadata::{
     DINodeCreationResult, NO_GENERICS, SmallVec, UNKNOWN_LINE_NUMBER, file_metadata,
@@ -244,7 +244,7 @@ fn build_enum_variant_part_di_node<'ll, 'tcx>(
             llvm::LLVMRustDIBuilderCreateVariantPart(
                 DIB(cx),
                 enum_type_di_node,
-                variant_part_name.as_ptr().cast(),
+                variant_part_name.as_c_char_ptr(),
                 variant_part_name.len(),
                 unknown_file_metadata(cx),
                 UNKNOWN_LINE_NUMBER,
@@ -253,7 +253,7 @@ fn build_enum_variant_part_di_node<'ll, 'tcx>(
                 DIFlags::FlagZero,
                 tag_member_di_node,
                 create_DIArray(DIB(cx), &[]),
-                variant_part_unique_type_id_str.as_ptr().cast(),
+                variant_part_unique_type_id_str.as_c_char_ptr(),
                 variant_part_unique_type_id_str.len(),
             )
         },
@@ -327,7 +327,7 @@ fn build_discr_member_di_node<'ll, 'tcx>(
                 Some(llvm::LLVMRustDIBuilderCreateMemberType(
                     DIB(cx),
                     containing_scope,
-                    tag_name.as_ptr().cast(),
+                    tag_name.as_c_char_ptr(),
                     tag_name.len(),
                     unknown_file_metadata(cx),
                     UNKNOWN_LINE_NUMBER,
@@ -399,7 +399,7 @@ fn build_enum_variant_member_di_node<'ll, 'tcx>(
         llvm::LLVMRustDIBuilderCreateVariantMemberType(
             DIB(cx),
             variant_part_di_node,
-            variant_member_info.variant_name.as_ptr().cast(),
+            variant_member_info.variant_name.as_c_char_ptr(),
             variant_member_info.variant_name.len(),
             file_di_node,
             line_number,

compiler/rustc_codegen_llvm/src/debuginfo/metadata/type_map.rs

@@ -9,7 +9,7 @@ use rustc_middle::ty::{ParamEnv, PolyExistentialTraitRef, Ty, TyCtxt};
 use rustc_target::abi::{Align, Size, VariantIdx};
 
 use super::{SmallVec, UNKNOWN_LINE_NUMBER, unknown_file_metadata};
-use crate::common::CodegenCx;
+use crate::common::{AsCCharPtr, CodegenCx};
 use crate::debuginfo::utils::{DIB, create_DIArray, debug_context};
 use crate::llvm::debuginfo::{DIFlags, DIScope, DIType};
 use crate::llvm::{self};
@@ -191,7 +191,7 @@ pub(super) fn stub<'ll, 'tcx>(
                 llvm::LLVMRustDIBuilderCreateStructType(
                     DIB(cx),
                     containing_scope,
-                    name.as_ptr().cast(),
+                    name.as_c_char_ptr(),
                     name.len(),
                     unknown_file_metadata(cx),
                     UNKNOWN_LINE_NUMBER,
@@ -202,7 +202,7 @@ pub(super) fn stub<'ll, 'tcx>(
                     empty_array,
                     0,
                     vtable_holder,
-                    unique_type_id_str.as_ptr().cast(),
+                    unique_type_id_str.as_c_char_ptr(),
                     unique_type_id_str.len(),
                 )
             }
@@ -211,7 +211,7 @@ pub(super) fn stub<'ll, 'tcx>(
             llvm::LLVMRustDIBuilderCreateUnionType(
                 DIB(cx),
                 containing_scope,
-                name.as_ptr().cast(),
+                name.as_c_char_ptr(),
                 name.len(),
                 unknown_file_metadata(cx),
                 UNKNOWN_LINE_NUMBER,
@@ -220,7 +220,7 @@ pub(super) fn stub<'ll, 'tcx>(
                 flags,
                 Some(empty_array),
                 0,
-                unique_type_id_str.as_ptr().cast(),
+                unique_type_id_str.as_c_char_ptr(),
                 unique_type_id_str.len(),
             )
         },

compiler/rustc_codegen_llvm/src/debuginfo/mod.rs

@@ -31,7 +31,7 @@ use self::namespace::mangled_name_of_instance;
 use self::utils::{DIB, create_DIArray, is_node_local_to_unit};
 use crate::abi::FnAbi;
 use crate::builder::Builder;
-use crate::common::CodegenCx;
+use crate::common::{AsCCharPtr, CodegenCx};
 use crate::llvm;
 use crate::llvm::debuginfo::{
     DIArray, DIBuilder, DIFile, DIFlags, DILexicalBlock, DILocation, DISPFlags, DIScope, DIType,
@@ -364,7 +364,7 @@ impl<'ll, 'tcx> DebugInfoCodegenMethods<'tcx> for CodegenCx<'ll, 'tcx> {
 
         let mut flags = DIFlags::FlagPrototyped;
 
-        if fn_abi.ret.layout.abi.is_uninhabited() {
+        if fn_abi.ret.layout.is_uninhabited() {
             flags |= DIFlags::FlagNoReturn;
         }
 
@@ -389,9 +389,9 @@ impl<'ll, 'tcx> DebugInfoCodegenMethods<'tcx> for CodegenCx<'ll, 'tcx> {
             llvm::LLVMRustDIBuilderCreateMethod(
                 DIB(self),
                 containing_scope,
-                name.as_ptr().cast(),
+                name.as_c_char_ptr(),
                 name.len(),
-                linkage_name.as_ptr().cast(),
+                linkage_name.as_c_char_ptr(),
                 linkage_name.len(),
                 file_metadata,
                 loc.line,
@@ -406,9 +406,9 @@ impl<'ll, 'tcx> DebugInfoCodegenMethods<'tcx> for CodegenCx<'ll, 'tcx> {
             llvm::LLVMRustDIBuilderCreateFunction(
                 DIB(self),
                 containing_scope,
-                name.as_ptr().cast(),
+                name.as_c_char_ptr(),
                 name.len(),
-                linkage_name.as_ptr().cast(),
+                linkage_name.as_c_char_ptr(),
                 linkage_name.len(),
                 file_metadata,
                 loc.line,
@@ -494,7 +494,7 @@ impl<'ll, 'tcx> DebugInfoCodegenMethods<'tcx> for CodegenCx<'ll, 'tcx> {
                                 Some(llvm::LLVMRustDIBuilderCreateTemplateTypeParameter(
                                     DIB(cx),
                                     None,
-                                    name.as_ptr().cast(),
+                                    name.as_c_char_ptr(),
                                     name.len(),
                                     actual_type_metadata,
                                 ))
@@ -635,7 +635,7 @@ impl<'ll, 'tcx> DebugInfoCodegenMethods<'tcx> for CodegenCx<'ll, 'tcx> {
                 DIB(self),
                 dwarf_tag,
                 scope_metadata,
-                name.as_ptr().cast(),
+                name.as_c_char_ptr(),
                 name.len(),
                 file_metadata,
                 loc.line,

compiler/rustc_codegen_llvm/src/debuginfo/namespace.rs

@@ -5,7 +5,7 @@ use rustc_hir::def_id::DefId;
 use rustc_middle::ty::{self, Instance};
 
 use super::utils::{DIB, debug_context};
-use crate::common::CodegenCx;
+use crate::common::{AsCCharPtr, CodegenCx};
 use crate::llvm;
 use crate::llvm::debuginfo::DIScope;
 
@@ -36,7 +36,7 @@ pub(crate) fn item_namespace<'ll>(cx: &CodegenCx<'ll, '_>, def_id: DefId) -> &'l
         llvm::LLVMRustDIBuilderCreateNameSpace(
             DIB(cx),
             parent_scope,
-            namespace_name_string.as_ptr().cast(),
+            namespace_name_string.as_c_char_ptr(),
             namespace_name_string.len(),
             false, // ExportSymbols (only relevant for C++ anonymous namespaces)
         )

compiler/rustc_codegen_llvm/src/declare.rs

@@ -20,6 +20,7 @@ use smallvec::SmallVec;
 use tracing::debug;
 
 use crate::abi::{FnAbi, FnAbiLlvmExt};
+use crate::common::AsCCharPtr;
 use crate::context::CodegenCx;
 use crate::llvm::AttributePlace::Function;
 use crate::llvm::Visibility;
@@ -41,7 +42,7 @@ fn declare_raw_fn<'ll>(
 ) -> &'ll Value {
     debug!("declare_raw_fn(name={:?}, ty={:?})", name, ty);
     let llfn = unsafe {
-        llvm::LLVMRustGetOrInsertFunction(cx.llmod, name.as_ptr().cast(), name.len(), ty)
+        llvm::LLVMRustGetOrInsertFunction(cx.llmod, name.as_c_char_ptr(), name.len(), ty)
     };
 
     llvm::SetFunctionCallConv(llfn, callconv);
@@ -68,7 +69,7 @@ impl<'ll, 'tcx> CodegenCx<'ll, 'tcx> {
     /// return its Value instead.
     pub(crate) fn declare_global(&self, name: &str, ty: &'ll Type) -> &'ll Value {
         debug!("declare_global(name={:?})", name);
-        unsafe { llvm::LLVMRustGetOrInsertGlobal(self.llmod, name.as_ptr().cast(), name.len(), ty) }
+        unsafe { llvm::LLVMRustGetOrInsertGlobal(self.llmod, name.as_c_char_ptr(), name.len(), ty) }
     }
 
     /// Declare a C ABI function.
@@ -209,7 +210,7 @@ impl<'ll, 'tcx> CodegenCx<'ll, 'tcx> {
     /// Gets declared value by name.
     pub(crate) fn get_declared_value(&self, name: &str) -> Option<&'ll Value> {
         debug!("get_declared_value(name={:?})", name);
-        unsafe { llvm::LLVMRustGetNamedValue(self.llmod, name.as_ptr().cast(), name.len()) }
+        unsafe { llvm::LLVMRustGetNamedValue(self.llmod, name.as_c_char_ptr(), name.len()) }
     }
 
     /// Gets defined or externally defined (AvailableExternally linkage) value by

compiler/rustc_codegen_llvm/src/llvm/mod.rs

@@ -17,13 +17,13 @@ pub use self::IntPredicate::*;
 pub use self::Linkage::*;
 pub use self::MetadataType::*;
 pub use self::RealPredicate::*;
+pub use self::ffi::*;
+use crate::common::AsCCharPtr;
 
 pub mod archive_ro;
 pub mod diagnostic;
 mod ffi;
 
-pub use self::ffi::*;
-
 impl LLVMRustResult {
     pub fn into_result(self) -> Result<(), ()> {
         match self {
@@ -53,9 +53,9 @@ pub fn CreateAttrStringValue<'ll>(llcx: &'ll Context, attr: &str, value: &str) -
     unsafe {
         LLVMCreateStringAttribute(
             llcx,
-            attr.as_ptr().cast(),
+            attr.as_c_char_ptr(),
             attr.len().try_into().unwrap(),
-            value.as_ptr().cast(),
+            value.as_c_char_ptr(),
             value.len().try_into().unwrap(),
         )
     }
@@ -65,7 +65,7 @@ pub fn CreateAttrString<'ll>(llcx: &'ll Context, attr: &str) -> &'ll Attribute {
     unsafe {
         LLVMCreateStringAttribute(
             llcx,
-            attr.as_ptr().cast(),
+            attr.as_c_char_ptr(),
             attr.len().try_into().unwrap(),
             std::ptr::null(),
             0,
@@ -294,7 +294,7 @@ pub fn get_value_name(value: &Value) -> &[u8] {
 /// Safe wrapper for `LLVMSetValueName2` from a byte slice
 pub fn set_value_name(value: &Value, name: &[u8]) {
     unsafe {
-        let data = name.as_ptr().cast();
+        let data = name.as_c_char_ptr();
         LLVMSetValueName2(value, data, name.len());
     }
 }

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -698,12 +698,9 @@ fn backend_feature_name<'a>(sess: &Session, s: &'a str) -> Option<&'a str> {
     let feature = s
         .strip_prefix(&['+', '-'][..])
         .unwrap_or_else(|| sess.dcx().emit_fatal(InvalidTargetFeaturePrefix { feature: s }));
-    if s.is_empty() {
-        return None;
-    }
     // Rustc-specific feature requests like `+crt-static` or `-crt-static`
     // are not passed down to LLVM.
-    if RUSTC_SPECIFIC_FEATURES.contains(&feature) {
+    if s.is_empty() || RUSTC_SPECIFIC_FEATURES.contains(&feature) {
         return None;
     }
     Some(feature)

compiler/rustc_codegen_ssa/src/mir/block.rs

@@ -438,7 +438,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 _ => bug!("C-variadic function must have a `VaList` place"),
             }
         }
-        if self.fn_abi.ret.layout.abi.is_uninhabited() {
+        if self.fn_abi.ret.layout.is_uninhabited() {
             // Functions with uninhabited return values are marked `noreturn`,
             // so we should make sure that we never actually do.
             // We play it safe by using a well-defined `abort`, but we could go for immediate UB
@@ -774,7 +774,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             Some(if do_panic {
                 let msg_str = with_no_visible_paths!({
                     with_no_trimmed_paths!({
-                        if layout.abi.is_uninhabited() {
+                        if layout.is_uninhabited() {
                             // Use this error even for the other intrinsics as it is more precise.
                             format!("attempted to instantiate uninhabited type `{ty}`")
                         } else if requirement == ValidityRequirement::Zero {

compiler/rustc_codegen_ssa/src/mir/place.rs

@@ -55,7 +55,7 @@ impl<V: CodegenObject> PlaceValue<V> {
     /// Creates a `PlaceRef` to this location with the given type.
     pub fn with_type<'tcx>(self, layout: TyAndLayout<'tcx>) -> PlaceRef<'tcx, V> {
         assert!(
-            layout.is_unsized() || layout.abi.is_uninhabited() || self.llextra.is_none(),
+            layout.is_unsized() || layout.is_uninhabited() || self.llextra.is_none(),
             "Had pointer metadata {:?} for sized type {layout:?}",
             self.llextra,
         );
@@ -239,7 +239,7 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> {
         let dl = &bx.tcx().data_layout;
         let cast_to_layout = bx.cx().layout_of(cast_to);
         let cast_to = bx.cx().immediate_backend_type(cast_to_layout);
-        if self.layout.abi.is_uninhabited() {
+        if self.layout.is_uninhabited() {
             return bx.cx().const_poison(cast_to);
         }
         let (tag_scalar, tag_encoding, tag_field) = match self.layout.variants {
@@ -358,7 +358,7 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> {
         bx: &mut Bx,
         variant_index: VariantIdx,
     ) {
-        if self.layout.for_variant(bx.cx(), variant_index).abi.is_uninhabited() {
+        if self.layout.for_variant(bx.cx(), variant_index).is_uninhabited() {
             // We play it safe by using a well-defined `abort`, but we could go for immediate UB
             // if that turns out to be helpful.
             bx.abort();

compiler/rustc_codegen_ssa/src/mir/rvalue.rs

@@ -203,10 +203,10 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
     ) -> Option<OperandValue<Bx::Value>> {
         // Check for transmutes that are always UB.
         if operand.layout.size != cast.size
-            || operand.layout.abi.is_uninhabited()
+            || operand.layout.is_uninhabited()
-            || cast.abi.is_uninhabited()
+            || cast.is_uninhabited()
         {
-            if !operand.layout.abi.is_uninhabited() {
+            if !operand.layout.is_uninhabited() {
                 // Since this is known statically and the input could have existed
                 // without already having hit UB, might as well trap for it.
                 bx.abort();
@@ -555,7 +555,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
 
                         assert!(bx.cx().is_backend_immediate(cast));
                         let to_backend_ty = bx.cx().immediate_backend_type(cast);
-                        if operand.layout.abi.is_uninhabited() {
+                        if operand.layout.is_uninhabited() {
                             let val = OperandValue::Immediate(bx.cx().const_poison(to_backend_ty));
                             return OperandRef { val, layout: cast };
                         }

compiler/rustc_const_eval/src/const_eval/machine.rs

@@ -395,7 +395,7 @@ impl<'tcx> interpret::Machine<'tcx> for CompileTimeMachine<'tcx> {
 
     #[inline(always)]
     fn enforce_validity(ecx: &InterpCx<'tcx, Self>, layout: TyAndLayout<'tcx>) -> bool {
-        ecx.tcx.sess.opts.unstable_opts.extra_const_ub_checks || layout.abi.is_uninhabited()
+        ecx.tcx.sess.opts.unstable_opts.extra_const_ub_checks || layout.is_uninhabited()
     }
 
     fn load_mir(

compiler/rustc_const_eval/src/interpret/discriminant.rs

@@ -27,7 +27,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         // discriminant, so we cannot do anything here.
         // When evaluating we will always error before even getting here, but ConstProp 'executes'
         // dead code, so we cannot ICE here.
-        if dest.layout().for_variant(self, variant_index).abi.is_uninhabited() {
+        if dest.layout().for_variant(self, variant_index).is_uninhabited() {
             throw_ub!(UninhabitedEnumVariantWritten(variant_index))
         }
 
@@ -86,7 +86,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                     // For consistency with `write_discriminant`, and to make sure that
                     // `project_downcast` cannot fail due to strange layouts, we declare immediate UB
                     // for uninhabited variants.
-                    if op.layout().for_variant(self, index).abi.is_uninhabited() {
+                    if op.layout().for_variant(self, index).is_uninhabited() {
                         throw_ub!(UninhabitedEnumVariantRead(index))
                     }
                 }
@@ -203,7 +203,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         // Reading the discriminant of an uninhabited variant is UB. This is the basis for the
         // `uninhabited_enum_branching` MIR pass. It also ensures consistency with
         // `write_discriminant`.
-        if op.layout().for_variant(self, index).abi.is_uninhabited() {
+        if op.layout().for_variant(self, index).is_uninhabited() {
             throw_ub!(UninhabitedEnumVariantRead(index))
         }
         interp_ok(index)

compiler/rustc_const_eval/src/interpret/intrinsics.rs

@@ -364,7 +364,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                     let msg = match requirement {
                         // For *all* intrinsics we first check `is_uninhabited` to give a more specific
                         // error message.
-                        _ if layout.abi.is_uninhabited() => format!(
+                        _ if layout.is_uninhabited() => format!(
                             "aborted execution: attempted to instantiate uninhabited type `{ty}`"
                         ),
                         ValidityRequirement::Inhabited => bug!("handled earlier"),

compiler/rustc_const_eval/src/interpret/operator.rs

@@ -315,7 +315,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                 let ptr = left.to_scalar().to_pointer(self)?;
                 let pointee_ty = left.layout.ty.builtin_deref(true).unwrap();
                 let pointee_layout = self.layout_of(pointee_ty)?;
-                assert!(pointee_layout.abi.is_sized());
+                assert!(pointee_layout.is_sized());
 
                 // The size always fits in `i64` as it can be at most `isize::MAX`.
                 let pointee_size = i64::try_from(pointee_layout.size.bytes()).unwrap();
@@ -518,14 +518,14 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
 
         interp_ok(match null_op {
             SizeOf => {
-                if !layout.abi.is_sized() {
+                if !layout.is_sized() {
                     span_bug!(self.cur_span(), "unsized type for `NullaryOp::SizeOf`");
                 }
                 let val = layout.size.bytes();
                 ImmTy::from_uint(val, usize_layout())
             }
             AlignOf => {
-                if !layout.abi.is_sized() {
+                if !layout.is_sized() {
                     span_bug!(self.cur_span(), "unsized type for `NullaryOp::AlignOf`");
                 }
                 let val = layout.align.abi.bytes();

compiler/rustc_const_eval/src/interpret/validity.rs

@@ -542,7 +542,7 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValidityVisitor<'rt, 'tcx, M> {
             throw_validation_failure!(self.path, NullPtr { ptr_kind })
         }
         // Do not allow references to uninhabited types.
-        if place.layout.abi.is_uninhabited() {
+        if place.layout.is_uninhabited() {
             let ty = place.layout.ty;
             throw_validation_failure!(self.path, PtrToUninhabited { ptr_kind, ty })
         }
@@ -867,7 +867,7 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValidityVisitor<'rt, 'tcx, M> {
     /// Add the entire given place to the "data" range of this visit.
     fn add_data_range_place(&mut self, place: &PlaceTy<'tcx, M::Provenance>) {
         // Only sized places can be added this way.
-        debug_assert!(place.layout.abi.is_sized());
+        debug_assert!(place.layout.is_sized());
         if let Some(data_bytes) = self.data_bytes.as_mut() {
             let offset = Self::data_range_offset(self.ecx, place);
             data_bytes.add_range(offset, place.layout.size);
@@ -945,7 +945,7 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValidityVisitor<'rt, 'tcx, M> {
         layout: TyAndLayout<'tcx>,
     ) -> Cow<'e, RangeSet> {
         assert!(layout.ty.is_union());
-        assert!(layout.abi.is_sized(), "there are no unsized unions");
+        assert!(layout.is_sized(), "there are no unsized unions");
         let layout_cx = LayoutCx::new(*ecx.tcx, ecx.param_env);
         return M::cached_union_data_range(ecx, layout.ty, || {
             let mut out = RangeSet(Vec::new());

compiler/rustc_const_eval/src/util/check_validity_requirement.rs

@@ -29,7 +29,7 @@ pub fn check_validity_requirement<'tcx>(
 
     // There is nothing strict or lax about inhabitedness.
     if kind == ValidityRequirement::Inhabited {
-        return Ok(!layout.abi.is_uninhabited());
+        return Ok(!layout.is_uninhabited());
     }
 
     let layout_cx = LayoutCx::new(tcx, param_env_and_ty.param_env);

compiler/rustc_errors/Cargo.toml

@@ -7,6 +7,7 @@ edition = "2021"
 # tidy-alphabetical-start
 annotate-snippets = "0.11"
 derive_setters = "0.1.6"
+rustc_abi = { path = "../rustc_abi" }
 rustc_ast = { path = "../rustc_ast" }
 rustc_ast_pretty = { path = "../rustc_ast_pretty" }
 rustc_data_structures = { path = "../rustc_data_structures" }

compiler/rustc_errors/src/diagnostic_impls.rs

@@ -5,12 +5,12 @@ use std::num::ParseIntError;
 use std::path::{Path, PathBuf};
 use std::process::ExitStatus;
 
+use rustc_abi::TargetDataLayoutErrors;
 use rustc_ast_pretty::pprust;
 use rustc_macros::Subdiagnostic;
 use rustc_span::Span;
 use rustc_span::edition::Edition;
 use rustc_span::symbol::{Ident, MacroRulesNormalizedIdent, Symbol};
-use rustc_target::abi::TargetDataLayoutErrors;
 use rustc_target::spec::{PanicStrategy, SplitDebuginfo, StackProtector, TargetTriple};
 use rustc_type_ir::{ClosureKind, FloatTy};
 use {rustc_ast as ast, rustc_hir as hir};

compiler/rustc_hir_analysis/Cargo.toml

@@ -10,6 +10,7 @@ doctest = false
 [dependencies]
 # tidy-alphabetical-start
 itertools = "0.12"
+rustc_abi = { path = "../rustc_abi" }
 rustc_arena = { path = "../rustc_arena" }
 rustc_ast = { path = "../rustc_ast" }
 rustc_attr = { path = "../rustc_attr" }

compiler/rustc_hir_analysis/src/check/check.rs

@@ -1,6 +1,7 @@
 use std::cell::LazyCell;
 use std::ops::ControlFlow;
 
+use rustc_abi::FieldIdx;
 use rustc_data_structures::unord::{UnordMap, UnordSet};
 use rustc_errors::MultiSpan;
 use rustc_errors::codes::*;
@@ -23,7 +24,6 @@ use rustc_middle::ty::{
     TypeVisitableExt,
 };
 use rustc_session::lint::builtin::UNINHABITED_STATIC;
-use rustc_target::abi::FieldIdx;
 use rustc_trait_selection::error_reporting::InferCtxtErrorExt;
 use rustc_trait_selection::error_reporting::traits::on_unimplemented::OnUnimplementedDirective;
 use rustc_trait_selection::traits;
@@ -172,7 +172,7 @@ fn check_static_inhabited(tcx: TyCtxt<'_>, def_id: LocalDefId) {
             return;
         }
     };
-    if layout.abi.is_uninhabited() {
+    if layout.is_uninhabited() {
         tcx.node_span_lint(
             UNINHABITED_STATIC,
             tcx.local_def_id_to_hir_id(def_id),

compiler/rustc_hir_analysis/src/check/intrinsicck.rs

@@ -1,5 +1,6 @@
 use std::assert_matches::debug_assert_matches;
 
+use rustc_abi::FieldIdx;
 use rustc_ast::InlineAsmTemplatePiece;
 use rustc_data_structures::fx::FxIndexSet;
 use rustc_hir::{self as hir, LangItem};
@@ -8,7 +9,6 @@ use rustc_middle::ty::{self, FloatTy, IntTy, Ty, TyCtxt, TypeVisitableExt, UintT
 use rustc_session::lint;
 use rustc_span::Symbol;
 use rustc_span::def_id::LocalDefId;
-use rustc_target::abi::FieldIdx;
 use rustc_target::asm::{
     InlineAsmReg, InlineAsmRegClass, InlineAsmRegOrRegClass, InlineAsmType, ModifierInfo,
 };

compiler/rustc_hir_analysis/src/check/mod.rs

@@ -74,6 +74,7 @@ pub mod wfcheck;
 use std::num::NonZero;
 
 pub use check::{check_abi, check_abi_fn_ptr};
+use rustc_abi::VariantIdx;
 use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
 use rustc_errors::{Diag, ErrorGuaranteed, pluralize, struct_span_code_err};
 use rustc_hir::def_id::{DefId, LocalDefId};
@@ -90,7 +91,6 @@ use rustc_session::parse::feature_err;
 use rustc_span::def_id::CRATE_DEF_ID;
 use rustc_span::symbol::{Ident, kw, sym};
 use rustc_span::{BytePos, DUMMY_SP, Span, Symbol};
-use rustc_target::abi::VariantIdx;
 use rustc_target::spec::abi::Abi;
 use rustc_trait_selection::error_reporting::InferCtxtErrorExt;
 use rustc_trait_selection::error_reporting::infer::ObligationCauseExt as _;

compiler/rustc_lint/Cargo.toml

@@ -5,6 +5,7 @@ edition = "2021"
 
 [dependencies]
 # tidy-alphabetical-start
+rustc_abi = { path = "../rustc_abi" }
 rustc_ast = { path = "../rustc_ast" }
 rustc_ast_pretty = { path = "../rustc_ast_pretty" }
 rustc_attr = { path = "../rustc_attr" }

compiler/rustc_lint/src/context.rs

@@ -11,7 +11,6 @@ use rustc_data_structures::sync;
 use rustc_data_structures::unord::UnordMap;
 use rustc_errors::{Diag, LintDiagnostic, MultiSpan};
 use rustc_feature::Features;
-use rustc_hir as hir;
 use rustc_hir::def::Res;
 use rustc_hir::def_id::{CrateNum, DefId};
 use rustc_hir::definitions::{DefPathData, DisambiguatedDefPathData};
@@ -27,8 +26,8 @@ use rustc_session::{LintStoreMarker, Session};
 use rustc_span::Span;
 use rustc_span::edit_distance::find_best_match_for_names;
 use rustc_span::symbol::{Ident, Symbol, sym};
-use rustc_target::abi;
 use tracing::debug;
+use {rustc_abi as abi, rustc_hir as hir};
 
 use self::TargetLint::*;
 use crate::levels::LintLevelsBuilder;

compiler/rustc_lint/src/foreign_modules.rs

@@ -1,3 +1,4 @@
+use rustc_abi::FIRST_VARIANT;
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_data_structures::unord::{UnordMap, UnordSet};
 use rustc_hir as hir;
@@ -6,7 +7,6 @@ use rustc_middle::query::Providers;
 use rustc_middle::ty::{self, AdtDef, Instance, Ty, TyCtxt};
 use rustc_session::declare_lint;
 use rustc_span::{Span, Symbol, sym};
-use rustc_target::abi::FIRST_VARIANT;
 use tracing::{debug, instrument};
 
 use crate::lints::{BuiltinClashingExtern, BuiltinClashingExternSub};

compiler/rustc_lint/src/types/literal.rs

@@ -1,8 +1,8 @@
 use hir::{ExprKind, Node, is_range_literal};
+use rustc_abi::{Integer, Size};
 use rustc_middle::ty::Ty;
 use rustc_middle::ty::layout::IntegerExt;
 use rustc_middle::{bug, ty};
-use rustc_target::abi::{Integer, Size};
 use {rustc_ast as ast, rustc_attr as attr, rustc_hir as hir};
 
 use crate::LateContext;

compiler/rustc_metadata/Cargo.toml

@@ -8,6 +8,7 @@ edition = "2021"
 bitflags = "2.4.1"
 libloading = "0.8.0"
 odht = { version = "0.3.1", features = ["nightly"] }
+rustc_abi = { path = "../rustc_abi" }
 rustc_ast = { path = "../rustc_ast" }
 rustc_attr = { path = "../rustc_attr" }
 rustc_data_structures = { path = "../rustc_data_structures" }

compiler/rustc_metadata/src/rmeta/mod.rs

@@ -6,6 +6,7 @@ use decoder::{DecodeContext, Metadata};
 use def_path_hash_map::DefPathHashMapRef;
 use encoder::EncodeContext;
 pub use encoder::{EncodedMetadata, encode_metadata, rendered_const};
+use rustc_abi::{FieldIdx, VariantIdx};
 use rustc_ast::expand::StrippedCfgItem;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::svh::Svh;
@@ -37,7 +38,6 @@ use rustc_span::edition::Edition;
 use rustc_span::hygiene::{ExpnIndex, MacroKind, SyntaxContextData};
 use rustc_span::symbol::{Ident, Symbol};
 use rustc_span::{self, ExpnData, ExpnHash, ExpnId, Span};
-use rustc_target::abi::{FieldIdx, VariantIdx};
 use rustc_target::spec::{PanicStrategy, TargetTriple};
 use table::TableBuilder;
 use {rustc_ast as ast, rustc_attr as attr, rustc_hir as hir};

compiler/rustc_middle/src/ty/layout.rs

@@ -346,7 +346,7 @@ impl<'tcx> SizeSkeleton<'tcx> {
         // First try computing a static layout.
         let err = match tcx.layout_of(param_env.and(ty)) {
             Ok(layout) => {
-                if layout.abi.is_sized() {
+                if layout.is_sized() {
                     return Ok(SizeSkeleton::Known(layout.size, Some(layout.align.abi)));
                 } else {
                     // Just to be safe, don't claim a known layout for unsized types.

compiler/rustc_mir_dataflow/Cargo.toml

@@ -7,6 +7,7 @@ edition = "2021"
 # tidy-alphabetical-start
 polonius-engine = "0.13.0"
 regex = "1"
+rustc_abi = { path = "../rustc_abi" }
 rustc_ast = { path = "../rustc_ast" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }

compiler/rustc_mir_dataflow/src/drop_flag_effects.rs

@@ -1,5 +1,5 @@
+use rustc_abi::VariantIdx;
 use rustc_middle::mir::{self, Body, Location, Terminator, TerminatorKind};
-use rustc_target::abi::VariantIdx;
 use tracing::debug;
 
 use super::move_paths::{InitKind, LookupResult, MoveData, MovePathIndex};

compiler/rustc_mir_dataflow/src/elaborate_drops.rs

@@ -1,5 +1,6 @@
 use std::{fmt, iter};
 
+use rustc_abi::{FIRST_VARIANT, FieldIdx, VariantIdx};
 use rustc_hir::lang_items::LangItem;
 use rustc_index::Idx;
 use rustc_middle::mir::patch::MirPatch;
@@ -10,7 +11,6 @@ use rustc_middle::ty::util::IntTypeExt;
 use rustc_middle::ty::{self, GenericArgsRef, Ty, TyCtxt};
 use rustc_span::DUMMY_SP;
 use rustc_span::source_map::Spanned;
-use rustc_target::abi::{FIRST_VARIANT, FieldIdx, VariantIdx};
 use tracing::{debug, instrument};
 
 /// The value of an inserted drop flag.

compiler/rustc_mir_dataflow/src/value_analysis.rs

@@ -36,6 +36,7 @@ use std::assert_matches::assert_matches;
 use std::fmt::{Debug, Formatter};
 use std::ops::Range;
 
+use rustc_abi::{FieldIdx, VariantIdx};
 use rustc_data_structures::captures::Captures;
 use rustc_data_structures::fx::{FxHashMap, FxIndexSet, StdEntry};
 use rustc_data_structures::stack::ensure_sufficient_stack;
@@ -46,7 +47,6 @@ use rustc_middle::mir::tcx::PlaceTy;
 use rustc_middle::mir::visit::{MutatingUseContext, PlaceContext, Visitor};
 use rustc_middle::mir::*;
 use rustc_middle::ty::{self, Ty, TyCtxt};
-use rustc_target::abi::{FieldIdx, VariantIdx};
 use tracing::debug;
 
 use crate::fmt::DebugWithContext;

compiler/rustc_mir_transform/Cargo.toml

@@ -7,6 +7,7 @@ edition = "2021"
 # tidy-alphabetical-start
 either = "1"
 itertools = "0.12"
+rustc_abi = { path = "../rustc_abi" }
 rustc_arena = { path = "../rustc_arena" }
 rustc_ast = { path = "../rustc_ast" }
 rustc_attr = { path = "../rustc_attr" }

compiler/rustc_mir_transform/src/unreachable_enum_branching.rs

@@ -1,5 +1,6 @@
 //! A pass that eliminates branches on uninhabited or unreachable enum variants.
 
+use rustc_abi::Variants;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_middle::bug;
 use rustc_middle::mir::patch::MirPatch;
@@ -9,7 +10,6 @@ use rustc_middle::mir::{
 };
 use rustc_middle::ty::layout::TyAndLayout;
 use rustc_middle::ty::{Ty, TyCtxt};
-use rustc_target::abi::{Abi, Variants};
 use tracing::trace;
 
 pub(super) struct UnreachableEnumBranching;
@@ -65,7 +65,7 @@ fn variant_discriminants<'tcx>(
         Variants::Multiple { variants, .. } => variants
             .iter_enumerated()
             .filter_map(|(idx, layout)| {
-                (layout.abi != Abi::Uninhabited)
+                (!layout.is_uninhabited())
                     .then(|| ty.discriminant_for_variant(tcx, idx).unwrap().val)
             })
             .collect(),

compiler/rustc_passes/Cargo.toml

@@ -5,6 +5,7 @@ edition = "2021"
 
 [dependencies]
 # tidy-alphabetical-start
+rustc_abi = { path = "../rustc_abi" }
 rustc_ast = { path = "../rustc_ast" }
 rustc_ast_pretty = { path = "../rustc_ast_pretty" }
 rustc_attr = { path = "../rustc_attr" }

compiler/rustc_passes/src/dead.rs

@@ -7,6 +7,7 @@ use std::mem;
 
 use hir::ItemKind;
 use hir::def_id::{LocalDefIdMap, LocalDefIdSet};
+use rustc_abi::FieldIdx;
 use rustc_data_structures::unord::UnordSet;
 use rustc_errors::MultiSpan;
 use rustc_hir as hir;
@@ -22,7 +23,6 @@ use rustc_middle::{bug, span_bug};
 use rustc_session::lint;
 use rustc_session::lint::builtin::DEAD_CODE;
 use rustc_span::symbol::{Symbol, sym};
-use rustc_target::abi::FieldIdx;
 
 use crate::errors::{
     ChangeFields, IgnoredDerivedImpls, MultipleDeadCodes, ParentInfo, UselessAssignment,

compiler/rustc_passes/src/layout_test.rs

@@ -1,3 +1,4 @@
+use rustc_abi::{HasDataLayout, TargetDataLayout};
 use rustc_ast::Attribute;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::LocalDefId;
@@ -7,7 +8,6 @@ use rustc_middle::ty::{self, ParamEnv, Ty, TyCtxt};
 use rustc_span::Span;
 use rustc_span::source_map::Spanned;
 use rustc_span::symbol::sym;
-use rustc_target::abi::{HasDataLayout, TargetDataLayout};
 use rustc_trait_selection::error_reporting::InferCtxtErrorExt;
 use rustc_trait_selection::infer::TyCtxtInferExt;
 use rustc_trait_selection::traits;

compiler/rustc_pattern_analysis/Cargo.toml

@@ -6,6 +6,8 @@ edition = "2021"
 [dependencies]
 # tidy-alphabetical-start
 rustc-hash = "2.0.0"
+
+rustc_abi = { path = "../rustc_abi", optional = true }
 rustc_apfloat = "0.2.0"
 rustc_arena = { path = "../rustc_arena", optional = true }
 rustc_data_structures = { path = "../rustc_data_structures", optional = true }
@@ -29,6 +31,7 @@ tracing-tree = "0.3.0"
 [features]
 default = ["rustc"]
 rustc = [
+    "dep:rustc_abi",
     "dep:rustc_arena",
     "dep:rustc_data_structures",
     "dep:rustc_errors",

compiler/rustc_pattern_analysis/src/rustc.rs

@@ -1,6 +1,7 @@
 use std::fmt;
 use std::iter::once;
 
+use rustc_abi::{FIRST_VARIANT, FieldIdx, Integer, VariantIdx};
 use rustc_arena::DroplessArena;
 use rustc_hir::HirId;
 use rustc_hir::def_id::DefId;
@@ -15,7 +16,6 @@ use rustc_middle::ty::{
 use rustc_middle::{bug, span_bug};
 use rustc_session::lint;
 use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span};
-use rustc_target::abi::{FIRST_VARIANT, FieldIdx, Integer, VariantIdx};
 
 use crate::constructor::Constructor::*;
 use crate::constructor::{

compiler/rustc_pattern_analysis/src/rustc/print.rs

@@ -11,10 +11,10 @@
 
 use std::fmt;
 
+use rustc_abi::{FieldIdx, VariantIdx};
 use rustc_middle::bug;
 use rustc_middle::ty::{self, AdtDef, Ty, TyCtxt};
 use rustc_span::sym;
-use rustc_target::abi::{FieldIdx, VariantIdx};
 
 #[derive(Clone, Debug)]
 pub(crate) struct FieldPat {

compiler/rustc_session/Cargo.toml

@@ -7,6 +7,7 @@ edition = "2021"
 # tidy-alphabetical-start
 bitflags = "2.4.1"
 getopts = "0.2"
+rustc_abi = { path = "../rustc_abi" }
 rustc_ast = { path = "../rustc_ast" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }

compiler/rustc_session/src/code_stats.rs

@@ -1,10 +1,10 @@
 use std::cmp;
 
+use rustc_abi::{Align, Size};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::sync::Lock;
 use rustc_span::Symbol;
 use rustc_span::def_id::DefId;
-use rustc_target::abi::{Align, Size};
 
 #[derive(Clone, PartialEq, Eq, Hash, Debug)]
 pub struct VariantInfo {

compiler/rustc_session/src/config/cfg.rs

@@ -23,12 +23,12 @@
 use std::hash::Hash;
 use std::iter;
 
+use rustc_abi::Align;
 use rustc_ast::ast;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexSet};
 use rustc_lint_defs::BuiltinLintDiag;
 use rustc_lint_defs::builtin::EXPLICIT_BUILTIN_CFGS_IN_FLAGS;
 use rustc_span::symbol::{Symbol, sym};
-use rustc_target::abi::Align;
 use rustc_target::spec::{PanicStrategy, RelocModel, SanitizerSet, TARGETS, Target, TargetTriple};
 
 use crate::Session;

compiler/rustc_smir/src/rustc_internal/mod.rs

@@ -170,7 +170,7 @@ impl<'tcx> Tables<'tcx> {
         stable_mir::mir::mono::StaticDef(self.create_def_id(did))
     }
 
-    pub(crate) fn layout_id(&mut self, layout: rustc_target::abi::Layout<'tcx>) -> Layout {
+    pub(crate) fn layout_id(&mut self, layout: rustc_abi::Layout<'tcx>) -> Layout {
         self.layouts.create_or_fetch(layout)
     }
 }

compiler/rustc_smir/src/rustc_smir/alloc.rs

@@ -1,3 +1,4 @@
+use rustc_abi::{Align, Size};
 use rustc_middle::mir::ConstValue;
 use rustc_middle::mir::interpret::{AllocRange, Pointer, alloc_range};
 use stable_mir::Error;
@@ -7,7 +8,7 @@ use stable_mir::ty::{Allocation, ProvenanceMap};
 use crate::rustc_smir::{Stable, Tables};
 
 /// Creates new empty `Allocation` from given `Align`.
-fn new_empty_allocation(align: rustc_target::abi::Align) -> Allocation {
+fn new_empty_allocation(align: Align) -> Allocation {
     Allocation {
         bytes: Vec::new(),
         provenance: ProvenanceMap { ptrs: Vec::new() },
@@ -45,7 +46,7 @@ pub(crate) fn try_new_allocation<'tcx>(
                 .align;
             let mut allocation = rustc_middle::mir::interpret::Allocation::uninit(size, align.abi);
             allocation
-                .write_scalar(&tables.tcx, alloc_range(rustc_target::abi::Size::ZERO, size), scalar)
+                .write_scalar(&tables.tcx, alloc_range(Size::ZERO, size), scalar)
                 .map_err(|e| e.stable(tables))?;
             allocation.stable(tables)
         }
@@ -59,7 +60,7 @@ pub(crate) fn try_new_allocation<'tcx>(
         }
         ConstValue::Slice { data, meta } => {
             let alloc_id = tables.tcx.reserve_and_set_memory_alloc(data);
-            let ptr = Pointer::new(alloc_id.into(), rustc_target::abi::Size::ZERO);
+            let ptr = Pointer::new(alloc_id.into(), Size::ZERO);
             let scalar_ptr = rustc_middle::mir::interpret::Scalar::from_pointer(ptr, &tables.tcx);
             let scalar_meta =
                 rustc_middle::mir::interpret::Scalar::from_target_usize(meta, &tables.tcx);
@@ -72,7 +73,7 @@ pub(crate) fn try_new_allocation<'tcx>(
             allocation
                 .write_scalar(
                     &tables.tcx,
-                    alloc_range(rustc_target::abi::Size::ZERO, tables.tcx.data_layout.pointer_size),
+                    alloc_range(Size::ZERO, tables.tcx.data_layout.pointer_size),
                     scalar_ptr,
                 )
                 .map_err(|e| e.stable(tables))?;
@@ -112,10 +113,7 @@ pub(super) fn allocation_filter<'tcx>(
         .map(Some)
         .collect();
     for (i, b) in bytes.iter_mut().enumerate() {
-        if !alloc
+        if !alloc.init_mask().get(Size::from_bytes(i + alloc_range.start.bytes_usize())) {
-            .init_mask()
-            .get(rustc_target::abi::Size::from_bytes(i + alloc_range.start.bytes_usize()))
-        {
             *b = None;
         }
     }

compiler/rustc_smir/src/rustc_smir/convert/abi.rs

@@ -1,9 +1,9 @@
-//! Conversion of internal Rust compiler `rustc_target::abi` and `rustc_abi` items to stable ones.
+//! Conversion of internal Rust compiler `rustc_target` and `rustc_abi` items to stable ones.
 
 #![allow(rustc::usage_of_qualified_ty)]
 
 use rustc_middle::ty;
-use rustc_target::abi::call::Conv;
+use rustc_target::callconv::{self, Conv};
 use stable_mir::abi::{
     AddressSpace, ArgAbi, CallConvention, FieldsShape, FloatLength, FnAbi, IntegerLength, Layout,
     LayoutShape, PassMode, Primitive, Scalar, TagEncoding, TyAndLayout, ValueAbi, VariantsShape,
@@ -15,7 +15,7 @@ use stable_mir::ty::{Align, IndexedVal, VariantIdx};
 
 use crate::rustc_smir::{Stable, Tables};
 
-impl<'tcx> Stable<'tcx> for rustc_target::abi::VariantIdx {
+impl<'tcx> Stable<'tcx> for rustc_abi::VariantIdx {
     type T = VariantIdx;
     fn stable(&self, _: &mut Tables<'_>) -> Self::T {
         VariantIdx::to_val(self.as_usize())
@@ -33,7 +33,7 @@ impl<'tcx> Stable<'tcx> for rustc_abi::Endian {
     }
 }
 
-impl<'tcx> Stable<'tcx> for rustc_target::abi::TyAndLayout<'tcx, ty::Ty<'tcx>> {
+impl<'tcx> Stable<'tcx> for rustc_abi::TyAndLayout<'tcx, ty::Ty<'tcx>> {
     type T = TyAndLayout;
 
     fn stable(&self, tables: &mut Tables<'_>) -> Self::T {
@@ -41,7 +41,7 @@ impl<'tcx> Stable<'tcx> for rustc_target::abi::TyAndLayout<'tcx, ty::Ty<'tcx>> {
     }
 }
 
-impl<'tcx> Stable<'tcx> for rustc_target::abi::Layout<'tcx> {
+impl<'tcx> Stable<'tcx> for rustc_abi::Layout<'tcx> {
     type T = Layout;
 
     fn stable(&self, tables: &mut Tables<'_>) -> Self::T {
@@ -49,9 +49,7 @@ impl<'tcx> Stable<'tcx> for rustc_target::abi::Layout<'tcx> {
     }
 }
 
-impl<'tcx> Stable<'tcx>
+impl<'tcx> Stable<'tcx> for rustc_abi::LayoutData<rustc_abi::FieldIdx, rustc_abi::VariantIdx> {
-    for rustc_abi::LayoutData<rustc_target::abi::FieldIdx, rustc_target::abi::VariantIdx>
-{
     type T = LayoutShape;
 
     fn stable(&self, tables: &mut Tables<'_>) -> Self::T {
@@ -65,7 +63,7 @@ impl<'tcx> Stable<'tcx>
     }
 }
 
-impl<'tcx> Stable<'tcx> for rustc_target::abi::call::FnAbi<'tcx, ty::Ty<'tcx>> {
+impl<'tcx> Stable<'tcx> for callconv::FnAbi<'tcx, ty::Ty<'tcx>> {
     type T = FnAbi;
 
     fn stable(&self, tables: &mut Tables<'_>) -> Self::T {
@@ -81,7 +79,7 @@ impl<'tcx> Stable<'tcx> for rustc_target::abi::call::FnAbi<'tcx, ty::Ty<'tcx>> {
     }
 }
 
-impl<'tcx> Stable<'tcx> for rustc_target::abi::call::ArgAbi<'tcx, ty::Ty<'tcx>> {
+impl<'tcx> Stable<'tcx> for callconv::ArgAbi<'tcx, ty::Ty<'tcx>> {
     type T = ArgAbi;
 
     fn stable(&self, tables: &mut Tables<'_>) -> Self::T {
@@ -93,7 +91,7 @@ impl<'tcx> Stable<'tcx> for rustc_target::abi::call::ArgAbi<'tcx, ty::Ty<'tcx>>
     }
 }
 
-impl<'tcx> Stable<'tcx> for rustc_target::abi::call::Conv {
+impl<'tcx> Stable<'tcx> for callconv::Conv {
     type T = CallConvention;
 
     fn stable(&self, _tables: &mut Tables<'_>) -> Self::T {
@@ -122,31 +120,29 @@ impl<'tcx> Stable<'tcx> for rustc_target::abi::call::Conv {
     }
 }
 
-impl<'tcx> Stable<'tcx> for rustc_target::abi::call::PassMode {
+impl<'tcx> Stable<'tcx> for callconv::PassMode {
     type T = PassMode;
 
     fn stable(&self, _tables: &mut Tables<'_>) -> Self::T {
         match self {
-            rustc_target::abi::call::PassMode::Ignore => PassMode::Ignore,
+            callconv::PassMode::Ignore => PassMode::Ignore,
-            rustc_target::abi::call::PassMode::Direct(attr) => PassMode::Direct(opaque(attr)),
+            callconv::PassMode::Direct(attr) => PassMode::Direct(opaque(attr)),
-            rustc_target::abi::call::PassMode::Pair(first, second) => {
+            callconv::PassMode::Pair(first, second) => {
                 PassMode::Pair(opaque(first), opaque(second))
             }
-            rustc_target::abi::call::PassMode::Cast { pad_i32, cast } => {
+            callconv::PassMode::Cast { pad_i32, cast } => {
                 PassMode::Cast { pad_i32: *pad_i32, cast: opaque(cast) }
             }
-            rustc_target::abi::call::PassMode::Indirect { attrs, meta_attrs, on_stack } => {
+            callconv::PassMode::Indirect { attrs, meta_attrs, on_stack } => PassMode::Indirect {
-                PassMode::Indirect {
+                attrs: opaque(attrs),
-                    attrs: opaque(attrs),
+                meta_attrs: opaque(meta_attrs),
-                    meta_attrs: opaque(meta_attrs),
+                on_stack: *on_stack,
-                    on_stack: *on_stack,
+            },
-                }
-            }
         }
     }
 }
 
-impl<'tcx> Stable<'tcx> for rustc_abi::FieldsShape<rustc_target::abi::FieldIdx> {
+impl<'tcx> Stable<'tcx> for rustc_abi::FieldsShape<rustc_abi::FieldIdx> {
     type T = FieldsShape;
 
     fn stable(&self, tables: &mut Tables<'_>) -> Self::T {
@@ -163,9 +159,7 @@ impl<'tcx> Stable<'tcx> for rustc_abi::FieldsShape<rustc_target::abi::FieldIdx>
     }
 }
 
-impl<'tcx> Stable<'tcx>
+impl<'tcx> Stable<'tcx> for rustc_abi::Variants<rustc_abi::FieldIdx, rustc_abi::VariantIdx> {
-    for rustc_abi::Variants<rustc_target::abi::FieldIdx, rustc_target::abi::VariantIdx>
-{
     type T = VariantsShape;
 
     fn stable(&self, tables: &mut Tables<'_>) -> Self::T {
@@ -185,7 +179,7 @@ impl<'tcx> Stable<'tcx>
     }
 }
 
-impl<'tcx> Stable<'tcx> for rustc_abi::TagEncoding<rustc_target::abi::VariantIdx> {
+impl<'tcx> Stable<'tcx> for rustc_abi::TagEncoding<rustc_abi::VariantIdx> {
     type T = TagEncoding;
 
     fn stable(&self, tables: &mut Tables<'_>) -> Self::T {

compiler/rustc_smir/src/rustc_smir/convert/mir.rs

@@ -691,11 +691,7 @@ impl<'tcx> Stable<'tcx> for mir::interpret::Allocation {
     type T = stable_mir::ty::Allocation;
 
     fn stable(&self, tables: &mut Tables<'_>) -> Self::T {
-        alloc::allocation_filter(
+        alloc::allocation_filter(self, alloc_range(rustc_abi::Size::ZERO, self.size()), tables)
-            self,
-            alloc_range(rustc_target::abi::Size::ZERO, self.size()),
-            tables,
-        )
     }
 }
 

compiler/rustc_smir/src/rustc_smir/mod.rs

@@ -36,7 +36,7 @@ pub struct Tables<'tcx> {
     pub(crate) instances: IndexMap<ty::Instance<'tcx>, InstanceDef>,
     pub(crate) ty_consts: IndexMap<ty::Const<'tcx>, TyConstId>,
     pub(crate) mir_consts: IndexMap<mir::Const<'tcx>, MirConstId>,
-    pub(crate) layouts: IndexMap<rustc_target::abi::Layout<'tcx>, Layout>,
+    pub(crate) layouts: IndexMap<rustc_abi::Layout<'tcx>, Layout>,
 }
 
 impl<'tcx> Tables<'tcx> {

compiler/rustc_symbol_mangling/Cargo.toml

@@ -7,6 +7,8 @@ edition = "2021"
 # tidy-alphabetical-start
 punycode = "0.4.0"
 rustc-demangle = "0.1.21"
+
+rustc_abi = { path = "../rustc_abi" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }
 rustc_hir = { path = "../rustc_hir" }

compiler/rustc_symbol_mangling/src/v0.rs

@@ -2,6 +2,7 @@ use std::fmt::Write;
 use std::iter;
 use std::ops::Range;
 
+use rustc_abi::Integer;
 use rustc_data_structures::base_n::ToBaseN;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::intern::Interned;
@@ -17,7 +18,6 @@ use rustc_middle::ty::{
     TyCtxt, TypeVisitable, TypeVisitableExt, UintTy,
 };
 use rustc_span::symbol::kw;
-use rustc_target::abi::Integer;
 use rustc_target::spec::abi::Abi;
 
 pub(super) fn mangle<'tcx>(

compiler/rustc_transmute/src/layout/tree.rs

@@ -339,9 +339,7 @@ pub(crate) mod rustc {
             // 2. enums that delegate their layout to a variant
             // 3. enums with multiple variants
             match layout.variants() {
-                Variants::Single { .. }
+                Variants::Single { .. } if layout.is_uninhabited() && layout.size == Size::ZERO => {
-                    if layout.abi.is_uninhabited() && layout.size == Size::ZERO =>
-                {
                     // The layout representation of uninhabited, ZST enums is
                     // defined to be like that of the `!` type, as opposed of a
                     // typical enum. Consequently, they cannot be descended into

compiler/rustc_ty_utils/src/layout/invariant.rs

@@ -10,7 +10,7 @@ pub(super) fn partially_check_layout<'tcx>(cx: &LayoutCx<'tcx>, layout: &TyAndLa
 
     // Type-level uninhabitedness should always imply ABI uninhabitedness.
     if layout.ty.is_privately_uninhabited(tcx, cx.param_env) {
-        assert!(layout.abi.is_uninhabited());
+        assert!(layout.is_uninhabited());
     }
 
     if layout.size.bytes() % layout.align.abi.bytes() != 0 {
@@ -262,9 +262,7 @@ pub(super) fn partially_check_layout<'tcx>(cx: &LayoutCx<'tcx>, layout: &TyAndLa
                 )
             }
             // Skip empty variants.
-            if variant.size == Size::ZERO
+            if variant.size == Size::ZERO || variant.fields.count() == 0 || variant.is_uninhabited()
-                || variant.fields.count() == 0
-                || variant.abi.is_uninhabited()
             {
                 // These are never actually accessed anyway, so we can skip the coherence check
                 // for them. They also fail that check, since they have

library/proc_macro/src/lib.rs

@@ -32,6 +32,7 @@
 #![feature(restricted_std)]
 #![feature(rustc_attrs)]
 #![feature(min_specialization)]
+#![feature(extend_one)]
 #![recursion_limit = "256"]
 #![allow(internal_features)]
 #![deny(ffi_unwind_calls)]
@@ -43,6 +44,7 @@ pub mod bridge;
 
 mod diagnostic;
 mod escape;
+mod to_tokens;
 
 use std::ffi::CStr;
 use std::ops::{Range, RangeBounds};
@@ -52,6 +54,8 @@ use std::{error, fmt};
 
 #[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
 pub use diagnostic::{Diagnostic, Level, MultiSpan};
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+pub use to_tokens::ToTokens;
 
 use crate::escape::{EscapeOptions, escape_bytes};
 

library/proc_macro/src/to_tokens.rs

@@ -0,0 +1,310 @@
+use std::borrow::Cow;
+use std::ffi::{CStr, CString};
+use std::rc::Rc;
+
+use crate::{ConcatTreesHelper, Group, Ident, Literal, Punct, Span, TokenStream, TokenTree};
+
+/// Types that can be interpolated inside a [`quote!`] invocation.
+///
+/// [`quote!`]: crate::quote!
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+pub trait ToTokens {
+    /// Write `self` to the given `TokenStream`.
+    ///
+    /// # Example
+    ///
+    /// Example implementation for a struct representing Rust paths like
+    /// `std::cmp::PartialEq`:
+    ///
+    /// ```
+    /// #![feature(proc_macro_totokens)]
+    ///
+    /// use std::iter;
+    /// use proc_macro::{Spacing, Punct, TokenStream, TokenTree, ToTokens};
+    ///
+    /// pub struct Path {
+    ///     pub global: bool,
+    ///     pub segments: Vec<PathSegment>,
+    /// }
+    ///
+    /// impl ToTokens for Path {
+    ///     fn to_tokens(&self, tokens: &mut TokenStream) {
+    ///         for (i, segment) in self.segments.iter().enumerate() {
+    ///             if i > 0 || self.global {
+    ///                 // Double colon `::`
+    ///                 tokens.extend(iter::once(TokenTree::from(Punct::new(':', Spacing::Joint))));
+    ///                 tokens.extend(iter::once(TokenTree::from(Punct::new(':', Spacing::Alone))));
+    ///             }
+    ///             segment.to_tokens(tokens);
+    ///         }
+    ///     }
+    /// }
+    /// #
+    /// # pub struct PathSegment;
+    /// #
+    /// # impl ToTokens for PathSegment {
+    /// #     fn to_tokens(&self, tokens: &mut TokenStream) {
+    /// #         unimplemented!()
+    /// #     }
+    /// # }
+    /// ```
+    fn to_tokens(&self, tokens: &mut TokenStream);
+
+    /// Convert `self` directly into a `TokenStream` object.
+    ///
+    /// This method is implicitly implemented using `to_tokens`, and acts as a
+    /// convenience method for consumers of the `ToTokens` trait.
+    fn to_token_stream(&self) -> TokenStream {
+        let mut tokens = TokenStream::new();
+        self.to_tokens(&mut tokens);
+        tokens
+    }
+
+    /// Convert `self` directly into a `TokenStream` object.
+    ///
+    /// This method is implicitly implemented using `to_tokens`, and acts as a
+    /// convenience method for consumers of the `ToTokens` trait.
+    fn into_token_stream(self) -> TokenStream
+    where
+        Self: Sized,
+    {
+        self.to_token_stream()
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for TokenTree {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        tokens.extend_one(self.clone());
+    }
+
+    fn into_token_stream(self) -> TokenStream {
+        let mut builder = ConcatTreesHelper::new(1);
+        builder.push(self);
+        builder.build()
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for TokenStream {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        tokens.extend(self.clone());
+    }
+
+    fn into_token_stream(self) -> TokenStream {
+        self
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for Literal {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        tokens.extend_one(TokenTree::from(self.clone()));
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for Ident {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        tokens.extend_one(TokenTree::from(self.clone()));
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for Punct {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        tokens.extend_one(TokenTree::from(self.clone()));
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for Group {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        tokens.extend_one(TokenTree::from(self.clone()));
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl<T: ToTokens + ?Sized> ToTokens for &T {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        (**self).to_tokens(tokens)
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl<T: ToTokens + ?Sized> ToTokens for &mut T {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        (**self).to_tokens(tokens)
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl<T: ToTokens + ?Sized> ToTokens for Box<T> {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        (**self).to_tokens(tokens)
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl<T: ToTokens + ?Sized> ToTokens for Rc<T> {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        (**self).to_tokens(tokens)
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl<T: ToTokens + ToOwned + ?Sized> ToTokens for Cow<'_, T> {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        (**self).to_tokens(tokens)
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl<T: ToTokens> ToTokens for Option<T> {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        if let Some(t) = self {
+            t.to_tokens(tokens);
+        }
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for u8 {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        Literal::u8_suffixed(*self).to_tokens(tokens)
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for u16 {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        Literal::u16_suffixed(*self).to_tokens(tokens)
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for u32 {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        Literal::u32_suffixed(*self).to_tokens(tokens)
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for u64 {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        Literal::u64_suffixed(*self).to_tokens(tokens)
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for u128 {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        Literal::u128_suffixed(*self).to_tokens(tokens)
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for i8 {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        Literal::i8_suffixed(*self).to_tokens(tokens)
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for i16 {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        Literal::i16_suffixed(*self).to_tokens(tokens)
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for i32 {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        Literal::i32_suffixed(*self).to_tokens(tokens)
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for i64 {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        Literal::i64_suffixed(*self).to_tokens(tokens)
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for i128 {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        Literal::i128_suffixed(*self).to_tokens(tokens)
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for f32 {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        Literal::f32_suffixed(*self).to_tokens(tokens)
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for f64 {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        Literal::f64_suffixed(*self).to_tokens(tokens)
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for usize {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        Literal::usize_suffixed(*self).to_tokens(tokens)
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for isize {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        Literal::isize_suffixed(*self).to_tokens(tokens)
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for bool {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        let word = if *self { "true" } else { "false" };
+        Ident::new(word, Span::call_site()).to_tokens(tokens)
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for char {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        Literal::character(*self).to_tokens(tokens)
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for str {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        Literal::string(self).to_tokens(tokens)
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for String {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        Literal::string(self).to_tokens(tokens)
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for CStr {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        Literal::c_string(self).to_tokens(tokens)
+    }
+}
+
+#[unstable(feature = "proc_macro_totokens", issue = "130977")]
+impl ToTokens for CString {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        Literal::c_string(self).to_tokens(tokens)
+    }
+}

src/doc/rustc/src/platform-support/fuchsia.md

@@ -525,14 +525,6 @@ ${SDK_PATH}/tools/${ARCH}/ffx repository publish \
     pkg/repo
 ```
 
-Then we can add the repository to `ffx`'s package server as `hello-fuchsia` using:
-
-```sh
-${SDK_PATH}/tools/${ARCH}/ffx repository add-from-pm \
-    --repository hello-fuchsia \
-    pkg/repo
-```
-
 ## Running a Fuchsia component on an emulator
 
 At this point, we are ready to run our Fuchsia
@@ -590,7 +582,8 @@ Now, start a package repository server to serve our
 package to the emulator:
 
 ```sh
-${SDK_PATH}/tools/${ARCH}/ffx repository server start
+${SDK_PATH}/tools/${ARCH}/ffx repository server start \
+    --background --repository hello-fuchsia --repo-path pkg-repo
 ```
 
 Once the repository server is up and running, register it with the target Fuchsia system running in the emulator:

src/librustdoc/html/render/type_layout.rs

@@ -60,8 +60,8 @@ pub(crate) fn document_type_layout<'a, 'cx: 'a>(
                         span_bug!(tcx.def_span(ty_def_id), "not an adt")
                     };
                     let name = adt.variant(variant_idx).name;
-                    let is_unsized = variant_layout.abi.is_unsized();
+                    let is_unsized = variant_layout.is_unsized();
-                    let is_uninhabited = variant_layout.abi.is_uninhabited();
+                    let is_uninhabited = variant_layout.is_uninhabited();
                     let size = variant_layout.size.bytes() - tag_size;
                     let type_layout_size = TypeLayoutSize { is_unsized, is_uninhabited, size };
                     (name, type_layout_size)
@@ -72,8 +72,8 @@ pub(crate) fn document_type_layout<'a, 'cx: 'a>(
         };
 
         let type_layout_size = tcx.layout_of(param_env.and(ty)).map(|layout| {
-            let is_unsized = layout.abi.is_unsized();
+            let is_unsized = layout.is_unsized();
-            let is_uninhabited = layout.abi.is_uninhabited();
+            let is_uninhabited = layout.is_uninhabited();
             let size = layout.size.bytes();
             TypeLayoutSize { is_unsized, is_uninhabited, size }
         });

src/librustdoc/html/static/css/rustdoc.css

@@ -230,7 +230,7 @@ h4.code-header {
 	padding: 0;
 	white-space: pre-wrap;
 }
-.structfield {
+.structfield, .sub-variant-field {
 	margin: 0.6em 0;
 }
 

tests/rustdoc-gui/fields.goml

@@ -1,6 +1,7 @@
 // This test checks that fields are displayed as expected (one by line) and they are surrounded
 // by margins.
 
+store-value: (margin, "9.6px")
 define-function: (
     "check-fields",
     [path, selector_1, selector_2],
@@ -12,8 +13,8 @@ define-function: (
 
         // Check the margins.
         assert-css: (".structfield.section-header", {
-            "margin-top": "9.6px",
+            "margin-top": |margin|,
-            "margin-bottom": "9.6px",
+            "margin-bottom": |margin|,
             "margin-left": "0px",
             "margin-right": "0px",
         }, ALL)
@@ -41,9 +42,9 @@ store-position: ("#variant\.B\.field\.b", {"y": b_y})
 assert: |a_y| < |b_y|
 
 // Check the margins.
-assert-css: (".sub-variant-field .section-header", {
+assert-css: (".sub-variant-field", {
-    "margin-top": "0px",
+    "margin-top": |margin|,
-    "margin-bottom": "0px",
+    "margin-bottom": |margin|,
-    "margin-left": "0px",
+    "margin-left": "24px",
     "margin-right": "0px",
 }, ALL)

tests/ui/thir-print/thir-tree-match.stdout

@@ -41,7 +41,7 @@ body:
                             Block {
                                 targeted_by_break: false
                                 span: $DIR/thir-tree-match.rs:15:32: 21:2 (#0)
-                                region_scope: Node(25)
+                                region_scope: Node(3)
                                 safety_mode: Safe
                                 stmts: []
                                 expr:
@@ -51,8 +51,8 @@ body:
                                         span: $DIR/thir-tree-match.rs:16:5: 20:6 (#0)
                                         kind: 
                                             Scope {
-                                                region_scope: Node(3)
+                                                region_scope: Node(4)
-                                                lint_level: Explicit(HirId(DefId(0:16 ~ thir_tree_match[fcf8]::has_match).3))
+                                                lint_level: Explicit(HirId(DefId(0:16 ~ thir_tree_match[fcf8]::has_match).4))
                                                 value:
                                                     Expr {
                                                         ty: bool
@@ -67,8 +67,8 @@ body:
                                                                         span: $DIR/thir-tree-match.rs:16:11: 16:14 (#0)
                                                                         kind: 
                                                                             Scope {
-                                                                                region_scope: Node(4)
+                                                                                region_scope: Node(5)
-                                                                                lint_level: Explicit(HirId(DefId(0:16 ~ thir_tree_match[fcf8]::has_match).4))
+                                                                                lint_level: Explicit(HirId(DefId(0:16 ~ thir_tree_match[fcf8]::has_match).5))
                                                                                 value:
                                                                                     Expr {
                                                                                         ty: Foo
@@ -123,16 +123,16 @@ body:
                                                                         body: 
                                                                             Expr {
                                                                                 ty: bool
-                                                                                temp_lifetime: Some(Node(12))
+                                                                                temp_lifetime: Some(Node(13))
                                                                                 span: $DIR/thir-tree-match.rs:17:36: 17:40 (#0)
                                                                                 kind: 
                                                                                     Scope {
-                                                                                        region_scope: Node(13)
+                                                                                        region_scope: Node(14)
-                                                                                        lint_level: Explicit(HirId(DefId(0:16 ~ thir_tree_match[fcf8]::has_match).13))
+                                                                                        lint_level: Explicit(HirId(DefId(0:16 ~ thir_tree_match[fcf8]::has_match).14))
                                                                                         value:
                                                                                             Expr {
                                                                                                 ty: bool
-                                                                                                temp_lifetime: Some(Node(12))
+                                                                                                temp_lifetime: Some(Node(13))
                                                                                                 span: $DIR/thir-tree-match.rs:17:36: 17:40 (#0)
                                                                                                 kind: 
                                                                                                     Literal( lit: Spanned { node: Bool(true), span: $DIR/thir-tree-match.rs:17:36: 17:40 (#0) }, neg: false)
@@ -140,8 +140,8 @@ body:
                                                                                             }
                                                                                     }
                                                                             }
-                                                                        lint_level: Explicit(HirId(DefId(0:16 ~ thir_tree_match[fcf8]::has_match).12))
+                                                                        lint_level: Explicit(HirId(DefId(0:16 ~ thir_tree_match[fcf8]::has_match).13))
-                                                                        scope: Node(12)
+                                                                        scope: Node(13)
                                                                         span: $DIR/thir-tree-match.rs:17:9: 17:40 (#0)
                                                                     }
                                                                     Arm {
@@ -175,16 +175,16 @@ body:
                                                                         body: 
                                                                             Expr {
                                                                                 ty: bool
-                                                                                temp_lifetime: Some(Node(18))
+                                                                                temp_lifetime: Some(Node(19))
                                                                                 span: $DIR/thir-tree-match.rs:18:27: 18:32 (#0)
                                                                                 kind: 
                                                                                     Scope {
-                                                                                        region_scope: Node(19)
+                                                                                        region_scope: Node(20)
-                                                                                        lint_level: Explicit(HirId(DefId(0:16 ~ thir_tree_match[fcf8]::has_match).19))
+                                                                                        lint_level: Explicit(HirId(DefId(0:16 ~ thir_tree_match[fcf8]::has_match).20))
                                                                                         value:
                                                                                             Expr {
                                                                                                 ty: bool
-                                                                                                temp_lifetime: Some(Node(18))
+                                                                                                temp_lifetime: Some(Node(19))
                                                                                                 span: $DIR/thir-tree-match.rs:18:27: 18:32 (#0)
                                                                                                 kind: 
                                                                                                     Literal( lit: Spanned { node: Bool(false), span: $DIR/thir-tree-match.rs:18:27: 18:32 (#0) }, neg: false)
@@ -192,8 +192,8 @@ body:
                                                                                             }
                                                                                     }
                                                                             }
-                                                                        lint_level: Explicit(HirId(DefId(0:16 ~ thir_tree_match[fcf8]::has_match).18))
+                                                                        lint_level: Explicit(HirId(DefId(0:16 ~ thir_tree_match[fcf8]::has_match).19))
-                                                                        scope: Node(18)
+                                                                        scope: Node(19)
                                                                         span: $DIR/thir-tree-match.rs:18:9: 18:32 (#0)
                                                                     }
                                                                     Arm {
@@ -219,16 +219,16 @@ body:
                                                                         body: 
                                                                             Expr {
                                                                                 ty: bool
-                                                                                temp_lifetime: Some(Node(23))
+                                                                                temp_lifetime: Some(Node(24))
                                                                                 span: $DIR/thir-tree-match.rs:19:24: 19:28 (#0)
                                                                                 kind: 
                                                                                     Scope {
-                                                                                        region_scope: Node(24)
+                                                                                        region_scope: Node(25)
-                                                                                        lint_level: Explicit(HirId(DefId(0:16 ~ thir_tree_match[fcf8]::has_match).24))
+                                                                                        lint_level: Explicit(HirId(DefId(0:16 ~ thir_tree_match[fcf8]::has_match).25))
                                                                                         value:
                                                                                             Expr {
                                                                                                 ty: bool
-                                                                                                temp_lifetime: Some(Node(23))
+                                                                                                temp_lifetime: Some(Node(24))
                                                                                                 span: $DIR/thir-tree-match.rs:19:24: 19:28 (#0)
                                                                                                 kind: 
                                                                                                     Literal( lit: Spanned { node: Bool(true), span: $DIR/thir-tree-match.rs:19:24: 19:28 (#0) }, neg: false)
@@ -236,8 +236,8 @@ body:
                                                                                             }
                                                                                     }
                                                                             }
-                                                                        lint_level: Explicit(HirId(DefId(0:16 ~ thir_tree_match[fcf8]::has_match).23))
+                                                                        lint_level: Explicit(HirId(DefId(0:16 ~ thir_tree_match[fcf8]::has_match).24))
-                                                                        scope: Node(23)
+                                                                        scope: Node(24)
                                                                         span: $DIR/thir-tree-match.rs:19:9: 19:28 (#0)
                                                                     }
                                                                 ]