Auto merge of rust-lang#122182 - matthiaskrgr:rollup-gzimi4c, r=matth…

…iaskrgr

Rollup of 8 pull requests

Successful merges:

 - rust-lang#118623 (Improve std::fs::read_to_string example)
 - rust-lang#119365 (Add asm goto support to `asm!`)
 - rust-lang#120608 (Docs for std::ptr::slice_from_raw_parts)
 - rust-lang#121832 (Add new Tier-3 target: `loongarch64-unknown-linux-musl`)
 - rust-lang#121938 (Fix quadratic behavior of repeated vectored writes)
 - rust-lang#122099 (Add  `#[inline]` to `BTreeMap::new` constructor)
 - rust-lang#122103 (Make TAITs and ATPITs capture late-bound lifetimes in scope)
 - rust-lang#122143 (PassWrapper: update for llvm/llvm-project@a3319371970b)

Failed merges:

 - rust-lang#122076 (Tweak the way we protect in-place function arguments in interpreters)

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

compiler/rustc_ast/src/ast.rs

@@ -2302,6 +2302,9 @@ pub enum InlineAsmOperand {
     Sym {
         sym: InlineAsmSym,
     },
+    Label {
+        block: P<Block>,
+    },
 }
 
 impl InlineAsmOperand {
@@ -2311,7 +2314,7 @@ impl InlineAsmOperand {
             | Self::Out { reg, .. }
             | Self::InOut { reg, .. }
             | Self::SplitInOut { reg, .. } => Some(reg),
-            Self::Const { .. } | Self::Sym { .. } => None,
+            Self::Const { .. } | Self::Sym { .. } | Self::Label { .. } => None,
         }
     }
 }

compiler/rustc_ast/src/mut_visit.rs

@@ -1331,6 +1331,7 @@ pub fn noop_visit_inline_asm<T: MutVisitor>(asm: &mut InlineAsm, vis: &mut T) {
             }
             InlineAsmOperand::Const { anon_const } => vis.visit_anon_const(anon_const),
             InlineAsmOperand::Sym { sym } => vis.visit_inline_asm_sym(sym),
+            InlineAsmOperand::Label { block } => vis.visit_block(block),
         }
     }
 }

compiler/rustc_ast/src/visit.rs

@@ -823,6 +823,7 @@ pub fn walk_inline_asm<'a, V: Visitor<'a>>(visitor: &mut V, asm: &'a InlineAsm)
                 try_visit!(visitor.visit_anon_const(anon_const))
             }
             InlineAsmOperand::Sym { sym } => try_visit!(visitor.visit_inline_asm_sym(sym)),
+            InlineAsmOperand::Label { block } => try_visit!(visitor.visit_block(block)),
         }
     }
     V::Result::output()

compiler/rustc_ast_lowering/messages.ftl

@@ -88,6 +88,9 @@ ast_lowering_invalid_abi_suggestion = did you mean
 ast_lowering_invalid_asm_template_modifier_const =
     asm template modifiers are not allowed for `const` arguments
 
+ast_lowering_invalid_asm_template_modifier_label =
+    asm template modifiers are not allowed for `label` arguments
+
 ast_lowering_invalid_asm_template_modifier_reg_class =
     invalid asm template modifier for this register class
 

compiler/rustc_ast_lowering/src/asm.rs

@@ -3,9 +3,9 @@ use crate::{ImplTraitContext, ImplTraitPosition, ParamMode, ResolverAstLoweringE
 use super::errors::{
     AbiSpecifiedMultipleTimes, AttSyntaxOnlyX86, ClobberAbiNotSupported,
     InlineAsmUnsupportedTarget, InvalidAbiClobberAbi, InvalidAsmTemplateModifierConst,
-    InvalidAsmTemplateModifierRegClass, InvalidAsmTemplateModifierRegClassSub,
-    InvalidAsmTemplateModifierSym, InvalidRegister, InvalidRegisterClass, RegisterClassOnlyClobber,
-    RegisterConflict,
+    InvalidAsmTemplateModifierLabel, InvalidAsmTemplateModifierRegClass,
+    InvalidAsmTemplateModifierRegClassSub, InvalidAsmTemplateModifierSym, InvalidRegister,
+    InvalidRegisterClass, RegisterClassOnlyClobber, RegisterConflict,
 };
 use super::LoweringContext;
 
@@ -237,6 +237,18 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                             }
                         }
                     }
+                    InlineAsmOperand::Label { block } => {
+                        if !self.tcx.features().asm_goto {
+                            feature_err(
+                                sess,
+                                sym::asm_goto,
+                                *op_sp,
+                                "label operands for inline assembly are unstable",
+                            )
+                            .emit();
+                        }
+                        hir::InlineAsmOperand::Label { block: self.lower_block(block, false) }
+                    }
                 };
                 (op, self.lower_span(*op_sp))
             })
@@ -296,6 +308,12 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                             op_span: op_sp,
                         });
                     }
+                    hir::InlineAsmOperand::Label { .. } => {
+                        self.dcx().emit_err(InvalidAsmTemplateModifierLabel {
+                            placeholder_span,
+                            op_span: op_sp,
+                        });
+                    }
                 }
             }
         }
@@ -335,7 +353,8 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
 
                         hir::InlineAsmOperand::Const { .. }
                         | hir::InlineAsmOperand::SymFn { .. }
-                        | hir::InlineAsmOperand::SymStatic { .. } => {
+                        | hir::InlineAsmOperand::SymStatic { .. }
+                        | hir::InlineAsmOperand::Label { .. } => {
                             unreachable!("{op:?} is not a register operand");
                         }
                     };

compiler/rustc_ast_lowering/src/errors.rs

@@ -261,6 +261,16 @@ pub struct InvalidAsmTemplateModifierSym {
     pub op_span: Span,
 }
 
+#[derive(Diagnostic, Clone, Copy)]
+#[diag(ast_lowering_invalid_asm_template_modifier_label)]
+pub struct InvalidAsmTemplateModifierLabel {
+    #[primary_span]
+    #[label(ast_lowering_template_modifier)]
+    pub placeholder_span: Span,
+    #[label(ast_lowering_argument)]
+    pub op_span: Span,
+}
+
 #[derive(Diagnostic, Clone, Copy)]
 #[diag(ast_lowering_register_class_only_clobber)]
 pub struct RegisterClassOnlyClobber {

compiler/rustc_ast_lowering/src/item.rs

@@ -275,7 +275,13 @@ impl<'hir> LoweringContext<'_, 'hir> {
                         }
                         Some(ty) => this.lower_ty(
                             ty,
-                            ImplTraitContext::TypeAliasesOpaqueTy { in_assoc_ty: false },
+                            ImplTraitContext::OpaqueTy {
+                                origin: hir::OpaqueTyOrigin::TyAlias {
+                                    parent: this.local_def_id(id),
+                                    in_assoc_ty: false,
+                                },
+                                fn_kind: None,
+                            },
                         ),
                     },
                 );
@@ -936,7 +942,13 @@ impl<'hir> LoweringContext<'_, 'hir> {
                         Some(ty) => {
                             let ty = this.lower_ty(
                                 ty,
-                                ImplTraitContext::TypeAliasesOpaqueTy { in_assoc_ty: true },
+                                ImplTraitContext::OpaqueTy {
+                                    origin: hir::OpaqueTyOrigin::TyAlias {
+                                        parent: this.local_def_id(i.id),
+                                        in_assoc_ty: true,
+                                    },
+                                    fn_kind: None,
+                                },
                             );
                             hir::ImplItemKind::Type(ty)
                         }

compiler/rustc_ast_lowering/src/lib.rs

@@ -265,13 +265,12 @@ enum ImplTraitContext {
     /// Example: `fn foo() -> impl Debug`, where `impl Debug` is conceptually
     /// equivalent to a new opaque type like `type T = impl Debug; fn foo() -> T`.
     ///
-    ReturnPositionOpaqueTy {
-        /// Origin: Either OpaqueTyOrigin::FnReturn or OpaqueTyOrigin::AsyncFn,
+    OpaqueTy {
         origin: hir::OpaqueTyOrigin,
-        fn_kind: FnDeclKind,
+        /// Only used to change the lifetime capture rules, since
+        /// RPITIT captures all in scope, RPIT does not.
+        fn_kind: Option<FnDeclKind>,
     },
-    /// Impl trait in type aliases.
-    TypeAliasesOpaqueTy { in_assoc_ty: bool },
     /// `impl Trait` is unstably accepted in this position.
     FeatureGated(ImplTraitPosition, Symbol),
     /// `impl Trait` is not accepted in this position.
@@ -1075,9 +1074,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                 // Disallow ATB in dyn types
                 if self.is_in_dyn_type {
                     let suggestion = match itctx {
-                        ImplTraitContext::ReturnPositionOpaqueTy { .. }
-                        | ImplTraitContext::TypeAliasesOpaqueTy { .. }
-                        | ImplTraitContext::Universal => {
+                        ImplTraitContext::OpaqueTy { .. } | ImplTraitContext::Universal => {
                             let bound_end_span = constraint
                                 .gen_args
                                 .as_ref()
@@ -1417,24 +1414,14 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             TyKind::ImplTrait(def_node_id, bounds) => {
                 let span = t.span;
                 match itctx {
-                    ImplTraitContext::ReturnPositionOpaqueTy { origin, fn_kind } => self
-                        .lower_opaque_impl_trait(
-                            span,
-                            origin,
-                            *def_node_id,
-                            bounds,
-                            Some(fn_kind),
-                            itctx,
-                        ),
-                    ImplTraitContext::TypeAliasesOpaqueTy { in_assoc_ty } => self
-                        .lower_opaque_impl_trait(
-                            span,
-                            hir::OpaqueTyOrigin::TyAlias { in_assoc_ty },
-                            *def_node_id,
-                            bounds,
-                            None,
-                            itctx,
-                        ),
+                    ImplTraitContext::OpaqueTy { origin, fn_kind } => self.lower_opaque_impl_trait(
+                        span,
+                        origin,
+                        *def_node_id,
+                        bounds,
+                        fn_kind,
+                        itctx,
+                    ),
                     ImplTraitContext::Universal => {
                         let span = t.span;
 
@@ -1553,9 +1540,14 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
 
         let captured_lifetimes_to_duplicate = match origin {
             hir::OpaqueTyOrigin::TyAlias { .. } => {
-                // in a TAIT like `type Foo<'a> = impl Foo<'a>`, we don't duplicate any
-                // lifetimes, since we don't have the issue that any are late-bound.
-                Vec::new()
+                // type alias impl trait and associated type position impl trait were
+                // decided to capture all in-scope lifetimes, which we collect for
+                // all opaques during resolution.
+                self.resolver
+                    .take_extra_lifetime_params(opaque_ty_node_id)
+                    .into_iter()
+                    .map(|(ident, id, _)| Lifetime { id, ident })
+                    .collect()
             }
             hir::OpaqueTyOrigin::FnReturn(..) => {
                 if matches!(
@@ -1823,9 +1815,9 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                         FnDeclKind::Fn
                         | FnDeclKind::Inherent
                         | FnDeclKind::Trait
-                        | FnDeclKind::Impl => ImplTraitContext::ReturnPositionOpaqueTy {
+                        | FnDeclKind::Impl => ImplTraitContext::OpaqueTy {
                             origin: hir::OpaqueTyOrigin::FnReturn(self.local_def_id(fn_node_id)),
-                            fn_kind: kind,
+                            fn_kind: Some(kind),
                         },
                         FnDeclKind::ExternFn => {
                             ImplTraitContext::Disallowed(ImplTraitPosition::ExternFnReturn)
@@ -1919,9 +1911,9 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                     output,
                     coro,
                     opaque_ty_span,
-                    ImplTraitContext::ReturnPositionOpaqueTy {
+                    ImplTraitContext::OpaqueTy {
                         origin: hir::OpaqueTyOrigin::FnReturn(fn_def_id),
-                        fn_kind,
+                        fn_kind: Some(fn_kind),
                     },
                 );
                 arena_vec![this; bound]

compiler/rustc_ast_lowering/src/path.rs

@@ -423,7 +423,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             // fn f(_: impl Fn() -> impl Debug) -> impl Fn() -> impl Debug
             // //      disallowed --^^^^^^^^^^        allowed --^^^^^^^^^^
             // ```
-            FnRetTy::Ty(ty) if matches!(itctx, ImplTraitContext::ReturnPositionOpaqueTy { .. }) => {
+            FnRetTy::Ty(ty) if matches!(itctx, ImplTraitContext::OpaqueTy { .. }) => {
                 if self.tcx.features().impl_trait_in_fn_trait_return {
                     self.lower_ty(ty, itctx)
                 } else {

compiler/rustc_ast_pretty/src/pprust/state.rs

@@ -1452,6 +1452,10 @@ impl<'a> State<'a> {
                             s.print_path(&sym.path, true, 0);
                         }
                     }
+                    InlineAsmOperand::Label { block } => {
+                        s.head("label");
+                        s.print_block(block);
+                    }
                 }
             }
             AsmArg::ClobberAbi(abi) => {

compiler/rustc_borrowck/src/lib.rs

@@ -723,7 +723,7 @@ impl<'cx, 'tcx, R> rustc_mir_dataflow::ResultsVisitor<'cx, 'tcx, R> for MirBorro
                 operands,
                 options: _,
                 line_spans: _,
-                destination: _,
+                targets: _,
                 unwind: _,
             } => {
                 for op in operands {
@@ -749,7 +749,8 @@ impl<'cx, 'tcx, R> rustc_mir_dataflow::ResultsVisitor<'cx, 'tcx, R> for MirBorro
                         }
                         InlineAsmOperand::Const { value: _ }
                         | InlineAsmOperand::SymFn { value: _ }
-                        | InlineAsmOperand::SymStatic { def_id: _ } => {}
+                        | InlineAsmOperand::SymStatic { def_id: _ }
+                        | InlineAsmOperand::Label { target_index: _ } => {}
                     }
                 }
             }

compiler/rustc_borrowck/src/polonius/loan_invalidations.rs

@@ -161,7 +161,7 @@ impl<'cx, 'tcx> Visitor<'tcx> for LoanInvalidationsGenerator<'cx, 'tcx> {
                 operands,
                 options: _,
                 line_spans: _,
-                destination: _,
+                targets: _,
                 unwind: _,
             } => {
                 for op in operands {
@@ -182,7 +182,8 @@ impl<'cx, 'tcx> Visitor<'tcx> for LoanInvalidationsGenerator<'cx, 'tcx> {
                         }
                         InlineAsmOperand::Const { value: _ }
                         | InlineAsmOperand::SymFn { value: _ }
-                        | InlineAsmOperand::SymStatic { def_id: _ } => {}
+                        | InlineAsmOperand::SymStatic { def_id: _ }
+                        | InlineAsmOperand::Label { target_index: _ } => {}
                     }
                 }
             }

compiler/rustc_borrowck/src/region_infer/opaque_types.rs

@@ -367,14 +367,17 @@ fn check_opaque_type_parameter_valid(
     span: Span,
 ) -> Result<(), ErrorGuaranteed> {
     let opaque_ty_hir = tcx.hir().expect_item(opaque_type_key.def_id);
-    let is_ty_alias = match opaque_ty_hir.expect_opaque_ty().origin {
-        OpaqueTyOrigin::TyAlias { .. } => true,
-        OpaqueTyOrigin::AsyncFn(..) | OpaqueTyOrigin::FnReturn(..) => false,
+    let (parent, is_ty_alias) = match opaque_ty_hir.expect_opaque_ty().origin {
+        OpaqueTyOrigin::TyAlias { parent, .. } => (parent, true),
+        OpaqueTyOrigin::AsyncFn(parent) | OpaqueTyOrigin::FnReturn(parent) => (parent, false),
     };
 
-    let opaque_generics = tcx.generics_of(opaque_type_key.def_id);
+    let parent_generics = tcx.generics_of(parent);
     let mut seen_params: FxIndexMap<_, Vec<_>> = FxIndexMap::default();
-    for (i, arg) in opaque_type_key.args.iter().enumerate() {
+
+    // Only check the parent generics, which will ignore any of the
+    // duplicated lifetime args that come from reifying late-bounds.
+    for (i, arg) in opaque_type_key.args.iter().take(parent_generics.count()).enumerate() {
         if let Err(guar) = arg.error_reported() {
             return Err(guar);
         }
@@ -395,7 +398,7 @@ fn check_opaque_type_parameter_valid(
             seen_params.entry(arg).or_default().push(i);
         } else {
             // Prevent `fn foo() -> Foo<u32>` from being defining.
-            let opaque_param = opaque_generics.param_at(i, tcx);
+            let opaque_param = parent_generics.param_at(i, tcx);
             let kind = opaque_param.kind.descr();
 
             return Err(tcx.dcx().emit_err(NonGenericOpaqueTypeParam {
@@ -409,10 +412,10 @@ fn check_opaque_type_parameter_valid(
 
     for (_, indices) in seen_params {
         if indices.len() > 1 {
-            let descr = opaque_generics.param_at(indices[0], tcx).kind.descr();
+            let descr = parent_generics.param_at(indices[0], tcx).kind.descr();
             let spans: Vec<_> = indices
                 .into_iter()
-                .map(|i| tcx.def_span(opaque_generics.param_at(i, tcx).def_id))
+                .map(|i| tcx.def_span(parent_generics.param_at(i, tcx).def_id))
                 .collect();
             #[allow(rustc::diagnostic_outside_of_impl)]
             #[allow(rustc::untranslatable_diagnostic)]

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -1770,8 +1770,8 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 self.assert_iscleanup(body, block_data, real_target, is_cleanup);
                 self.assert_iscleanup_unwind(body, block_data, unwind, is_cleanup);
             }
-            TerminatorKind::InlineAsm { destination, unwind, .. } => {
-                if let Some(target) = destination {
+            TerminatorKind::InlineAsm { ref targets, unwind, .. } => {
+                for &target in targets {
                     self.assert_iscleanup(body, block_data, target, is_cleanup);
                 }
                 self.assert_iscleanup_unwind(body, block_data, unwind, is_cleanup);

compiler/rustc_builtin_macros/messages.ftl

@@ -19,6 +19,8 @@ builtin_macros_asm_expected_other = expected operand, {$is_global_asm ->
 
 builtin_macros_asm_explicit_register_name = explicit register arguments cannot have names
 
+builtin_macros_asm_mayunwind = asm labels are not allowed with the `may_unwind` option
+
 builtin_macros_asm_modifier_invalid = asm template modifier must be a single character
 
 builtin_macros_asm_mutually_exclusive = the `{$opt1}` and `{$opt2}` options are mutually exclusive