Auto merge of #158593 - JonathanBrouwer:rollup-tGO5Zmu, r=JonathanBrouwer

Rollup of 11 pull requests

Successful merges:

 - #155722 (Introduce aarch64-unknown-linux-pauthtest target)
 - #156230 (tests: check wasm compiler_builtins object architecture)
 - #156295 (Pass the whole `GenericArgs` to `Interner::for_each_relevant_impl()`)
 - #158375 (Support `DefKind::InlineConst` in `ConstKind::Unevaluated`)
 - #158556 (delegation: store child segment flag in `PathSegment`)
 - #158081 (trait-system: Recover deferred closure calls after errors)
 - #158468 (Include default-stability info in rustdoc JSON.)
 - #158543 (Note usage of documentation hard links in `core::io`)
 - #158564 (fix `-Z min-recursion-limit` unstable chapter name)
 - #158568 (llvm-wrapper: use accessors for private fields in LLVM 23+)
 - #158582 (Comment on needed RAM in huge-stacks.rs)

Author: bors

compiler/rustc_ast_lowering/src/delegation.rs

@@ -55,7 +55,9 @@ use rustc_span::def_id::{DefId, LocalDefId};
 use rustc_span::symbol::kw;
 use rustc_span::{ErrorGuaranteed, Ident, Span, Symbol};
 
-use crate::delegation::generics::{GenericsGenerationResult, GenericsGenerationResults};
+use crate::delegation::generics::{
+    GenericsGenerationResult, GenericsGenerationResults, GenericsPosition,
+};
 use crate::diagnostics::{
     CycleInDelegationSignatureResolution, DelegationAttemptedBlockWithDefsDeletion,
     DelegationBlockSpecifiedWhenNoParams, UnresolvedDelegationCallee,
@@ -505,6 +507,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             res: Res::Local(param_id),
             args: None,
             infer_args: false,
+            delegation_child_segment: false,
         }));
 
         let path = self.arena.alloc(hir::Path { span, res: Res::Local(param_id), segments });
@@ -714,6 +717,8 @@ impl<'hir> LoweringContext<'_, 'hir> {
         result.args_segment_id = segment.hir_id;
         result.use_for_sig_inheritance = !result.generics.is_trait_impl();
 
+        segment.delegation_child_segment = result.generics.pos() == GenericsPosition::Child;
+
         segment
     }
 

compiler/rustc_ast_lowering/src/delegation/generics.rs

@@ -12,7 +12,7 @@ use rustc_span::{Ident, Span, sym};
 use crate::LoweringContext;
 use crate::diagnostics::DelegationInfersMismatch;
 
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
 pub(super) enum GenericsPosition {
     Parent,
     Child,
@@ -155,7 +155,7 @@ impl<'hir> DelegationGenericArgsIterator<'hir> {
 impl<'hir> HirOrTyGenerics<'hir> {
     pub(super) fn into_hir_generics(&mut self, ctx: &mut LoweringContext<'_, 'hir>, span: Span) {
         if let HirOrTyGenerics::Ty(ty) = self {
-            let rename_self = matches!(ty.pos, GenericsPosition::Child);
+            let rename_self = ty.pos == GenericsPosition::Child;
             let params = ctx.uplift_delegation_generic_params(span, &ty.data, rename_self);
 
             *self = HirOrTyGenerics::Hir(DelegationGenerics {
@@ -218,6 +218,13 @@ impl<'hir> HirOrTyGenerics<'hir> {
                 .expect("`Self` generic param is not found while expected"),
         }
     }
+
+    pub(crate) fn pos(&self) -> GenericsPosition {
+        match self {
+            HirOrTyGenerics::Ty(ty) => ty.pos,
+            HirOrTyGenerics::Hir(hir) => hir.pos,
+        }
+    }
 }
 
 impl<'hir> GenericsGenerationResult<'hir> {
@@ -590,6 +597,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                     ident: p.name.ident(),
                     infer_args: false,
                     res,
+                    delegation_child_segment: false,
                 }]),
                 res,
                 span: p.span,

compiler/rustc_ast_lowering/src/lib.rs

@@ -1014,6 +1014,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 res,
                 args,
                 infer_args: args.is_none(),
+                delegation_child_segment: false,
             }]),
         })
     }
@@ -2791,7 +2792,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             }
             ExprKind::ConstBlock(anon_const) => {
                 let def_id = self.local_def_id(anon_const.id);
-                assert_eq!(DefKind::AnonConst, self.tcx.def_kind(def_id));
+                assert_eq!(DefKind::InlineConst, self.tcx.def_kind(def_id));
                 self.lower_anon_const_to_const_arg(anon_const, span)
             }
             _ => overly_complex_const(self),

compiler/rustc_ast_lowering/src/path.rs

@@ -412,6 +412,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             } else {
                 Some(generic_args.into_generic_args(self))
             },
+            delegation_child_segment: false,
         }
     }
 

compiler/rustc_borrowck/src/universal_regions.rs

@@ -615,7 +615,7 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
 
             BodyOwnerKind::Const { .. } | BodyOwnerKind::Static(..) => {
                 match tcx.def_kind(self.mir_def) {
-                    DefKind::InlineConst => {
+                    DefKind::InlineConst if !tcx.is_type_system_inline_const(self.mir_def) => {
                         // This is required for `AscribeUserType` canonical query, which will call
                         // `type_of(inline_const_def_id)`. That `type_of` would inject erased lifetimes
                         // into borrowck, which is ICE #78174.

compiler/rustc_codegen_gcc/src/common.rs

@@ -2,7 +2,8 @@ use gccjit::{LValue, RValue, ToRValue, Type};
 use rustc_abi::Primitive::Pointer;
 use rustc_abi::{self as abi, HasDataLayout};
 use rustc_codegen_ssa::traits::{
-    BaseTypeCodegenMethods, ConstCodegenMethods, MiscCodegenMethods, StaticCodegenMethods,
+    BaseTypeCodegenMethods, ConstCodegenMethods, MiscCodegenMethods, PacMetadata,
+    StaticCodegenMethods,
 };
 use rustc_middle::mir::Mutability;
 use rustc_middle::mir::interpret::{GlobalAlloc, PointerArithmetic, Scalar};
@@ -241,7 +242,13 @@ impl<'gcc, 'tcx> ConstCodegenMethods for CodegenCx<'gcc, 'tcx> {
         None
     }
 
-    fn scalar_to_backend(&self, cv: Scalar, layout: abi::Scalar, ty: Type<'gcc>) -> RValue<'gcc> {
+    fn scalar_to_backend_with_pac(
+        &self,
+        cv: Scalar,
+        layout: abi::Scalar,
+        ty: Type<'gcc>,
+        _pac: Option<PacMetadata>,
+    ) -> RValue<'gcc> {
         let bitsize = if layout.is_bool() { 1 } else { layout.size(self).bits() };
         match cv {
             Scalar::Int(int) => {
@@ -290,7 +297,7 @@ impl<'gcc, 'tcx> ConstCodegenMethods for CodegenCx<'gcc, 'tcx> {
                         }
                         value
                     }
-                    GlobalAlloc::Function { instance, .. } => self.get_fn_addr(instance),
+                    GlobalAlloc::Function { instance, .. } => self.get_fn_addr(instance, None),
                     GlobalAlloc::VTable(ty, dyn_ty) => {
                         let alloc = self
                             .tcx

compiler/rustc_codegen_gcc/src/context.rs

@@ -5,7 +5,9 @@ use gccjit::{Block, CType, Context, Function, FunctionType, LValue, Location, RV
 use rustc_abi::{Align, HasDataLayout, PointeeInfo, Size, TargetDataLayout, VariantIdx};
 use rustc_codegen_ssa::base::wants_msvc_seh;
 use rustc_codegen_ssa::errors as ssa_errors;
-use rustc_codegen_ssa::traits::{BackendTypes, BaseTypeCodegenMethods, MiscCodegenMethods};
+use rustc_codegen_ssa::traits::{
+    BackendTypes, BaseTypeCodegenMethods, MiscCodegenMethods, PacMetadata,
+};
 use rustc_data_structures::base_n::{ALPHANUMERIC_ONLY, ToBaseN};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_middle::mir::interpret::Allocation;
@@ -398,7 +400,7 @@ impl<'gcc, 'tcx> MiscCodegenMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
         get_fn(self, instance)
     }
 
-    fn get_fn_addr(&self, instance: Instance<'tcx>) -> RValue<'gcc> {
+    fn get_fn_addr(&self, instance: Instance<'tcx>, _pac: Option<PacMetadata>) -> RValue<'gcc> {
         let func_name = self.tcx.symbol_name(instance).name;
 
         let func = if let Some(variable) = self.get_declared_value(func_name) {

compiler/rustc_codegen_llvm/src/attributes.rs

@@ -12,9 +12,12 @@ use rustc_session::config::{
 };
 use rustc_span::sym;
 use rustc_symbol_mangling::mangle_internal_symbol;
-use rustc_target::spec::{Arch, FramePointer, SanitizerSet, StackProbeType, StackProtector};
+use rustc_target::spec::{
+    Arch, FramePointer, LlvmAbi, SanitizerSet, StackProbeType, StackProtector,
+};
 use smallvec::SmallVec;
 
+use crate::common::pauth_fn_attrs;
 use crate::context::SimpleCx;
 use crate::errors::{PackedStackBackchainNeedsSoftfloat, SanitizerMemtagRequiresMte};
 use crate::llvm::AttributePlace::Function;
@@ -643,6 +646,12 @@ pub(crate) fn llfn_attrs_from_instance<'ll, 'tcx>(
         }
     }
 
+    if sess.target.llvm_abiname == LlvmAbi::Pauthtest {
+        for &ptrauth_attr in pauth_fn_attrs() {
+            to_add.push(llvm::CreateAttrString(cx.llcx, ptrauth_attr));
+        }
+    }
+
     to_add.extend(target_features_attr(cx, tcx, function_features));
 
     attributes::apply_to_llfn(llfn, Function, &to_add);

compiler/rustc_codegen_llvm/src/base.rs

@@ -25,12 +25,13 @@ use rustc_middle::mono::Visibility;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::config::{DebugInfo, Offload};
 use rustc_span::Symbol;
-use rustc_target::spec::SanitizerSet;
+use rustc_target::spec::{LlvmAbi, SanitizerSet};
 
 use super::ModuleLlvm;
 use crate::attributes;
 use crate::builder::Builder;
 use crate::builder::gpu_offload::OffloadGlobals;
+use crate::common::pauth_fn_attrs;
 use crate::context::CodegenCx;
 use crate::llvm::{self, Value};
 
@@ -123,7 +124,18 @@ pub(crate) fn compile_codegen_unit(
             if let Some(entry) =
                 maybe_create_entry_wrapper::<Builder<'_, '_, '_>>(&cx, cx.codegen_unit)
             {
-                let attrs = attributes::sanitize_attrs(&cx, tcx, SanitizerFnAttrs::default());
+                let mut attrs = attributes::sanitize_attrs(&cx, tcx, SanitizerFnAttrs::default());
+                // When pointer authentication is enabled, ensure that the ptrauth-* attributes are
+                // also attached to the entry wrapper.
+                //
+                // FIXME(jchlanda) If it ever becomes necessary to ensure that all compiler
+                // generated functions receive the ptrauth-* attributes, `declare_fn` or
+                // `declare_raw_fn` could be used to provide those.
+                if cx.sess().target.llvm_abiname == LlvmAbi::Pauthtest {
+                    for &ptrauth_attr in pauth_fn_attrs() {
+                        attrs.push(llvm::CreateAttrString(cx.llcx, ptrauth_attr));
+                    }
+                }
                 attributes::apply_to_llfn(entry, llvm::AttributePlace::Function, &attrs);
             }
 
@@ -140,6 +152,30 @@ pub(crate) fn compile_codegen_unit(
                 cx.add_objc_module_flags();
             }
 
+            if cx.sess().target.llvm_abiname == LlvmAbi::Pauthtest {
+                // FIXME(jchlanda): In LLVM/Clang, there are also `aarch64-elf-pauthabi-platform`
+                // and `aarch64-elf-pauthabi-version` module flags. These are emitted into the
+                // PAuth core info section of the resulting ELF, which the linker uses to enforce
+                // binary compatibility.
+                //
+                // We intentionally do not emit these flags now, since only a subset of features
+                // included in clang's pauthtest is currently supported. By default, the absence of
+                // this info is treated as compatible with any binary.
+                //
+                // Please note, that this would cause compatibility issues, specifically runtime
+                // crashes due to authentication failures (while compiling and linking
+                // successfully) when linking against binaries that support larger set of features
+                // (for example, signing of C++ member function pointers, virtual function
+                // pointers, virtual table pointers).
+                //
+                // Link to PAuth core info documentation:
+                // <https://github.com/ARM-software/abi-aa/blob/2025Q4/pauthabielf64/pauthabielf64.rst#core-information>
+                if cx.sess().opts.unstable_opts.ptrauth_elf_got {
+                    cx.add_ptrauth_elf_got_flag();
+                }
+                cx.add_ptrauth_sign_personality_flag();
+            }
+
             // Finalize code coverage by injecting the coverage map. Note, the coverage map will
             // also be added to the `llvm.compiler.used` variable, created next.
             if cx.sess().instrument_coverage() {

compiler/rustc_codegen_llvm/src/builder.rs

@@ -7,7 +7,7 @@ pub(crate) mod autodiff;
 pub(crate) mod gpu_offload;
 
 use libc::{c_char, c_uint};
-use rustc_abi::{self as abi, Align, Size, WrappingRange};
+use rustc_abi::{self as abi, Align, CanonAbi, Size, WrappingRange};
 use rustc_codegen_ssa::MemFlags;
 use rustc_codegen_ssa::common::{IntPredicate, RealPredicate, SynchronizationScope, TypeKind};
 use rustc_codegen_ssa::mir::operand::{OperandRef, OperandValue};
@@ -26,7 +26,7 @@ use rustc_sanitizers::{cfi, kcfi};
 use rustc_session::config::OptLevel;
 use rustc_span::Span;
 use rustc_target::callconv::{FnAbi, PassMode};
-use rustc_target::spec::{Arch, HasTargetSpec, SanitizerSet, Target};
+use rustc_target::spec::{Arch, HasTargetSpec, LlvmAbi, SanitizerSet, Target};
 use smallvec::SmallVec;
 use tracing::{debug, instrument};
 
@@ -475,6 +475,11 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
             bundles.push(kcfi_bundle);
         }
 
+        let pauth = self.ptrauth_operand_bundle(llfn, fn_abi);
+        if let Some(p) = pauth.as_ref().map(|b| b.as_ref()) {
+            bundles.push(p);
+        }
+
         let invoke = unsafe {
             llvm::LLVMBuildInvokeWithOperandBundles(
                 self.llbuilder,
@@ -1472,6 +1477,11 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
             bundles.push(kcfi_bundle);
         }
 
+        let pauth = self.ptrauth_operand_bundle(llfn, fn_abi);
+        if let Some(p) = pauth.as_ref().map(|b| b.as_ref()) {
+            bundles.push(p);
+        }
+
         let call = unsafe {
             llvm::LLVMBuildCallWithOperandBundles(
                 self.llbuilder,
@@ -1902,6 +1912,11 @@ impl<'a, 'll, 'tcx> Builder<'a, 'll, 'tcx> {
             bundles.push(kcfi_bundle);
         }
 
+        let pauth = self.ptrauth_operand_bundle(llfn, fn_abi);
+        if let Some(p) = pauth.as_ref().map(|b| b.as_ref()) {
+            bundles.push(p);
+        }
+
         let callbr = unsafe {
             llvm::LLVMBuildCallBr(
                 self.llbuilder,
@@ -2021,6 +2036,40 @@ impl<'a, 'll, 'tcx> Builder<'a, 'll, 'tcx> {
         kcfi_bundle
     }
 
+    // Emits pauth operand bundle.
+    fn ptrauth_operand_bundle(
+        &mut self,
+        llfn: &'ll Value,
+        fn_abi: Option<&FnAbi<'tcx, Ty<'tcx>>>,
+    ) -> Option<llvm::OperandBundleBox<'ll>> {
+        if self.sess().target.llvm_abiname != LlvmAbi::Pauthtest {
+            return None;
+        }
+        // Pointer authentication support is currently limited to extern "C" calls; filter out other
+        // ABIs.
+        if fn_abi?.conv != CanonAbi::C {
+            return None;
+        }
+        // Filter out LLVM intrinsics.
+        if llvm::get_value_name(llfn).starts_with(b"llvm.") {
+            return None;
+        }
+
+        // FIXME(jchlanda) Operand bundles should only be attached to indirect function calls.
+        // However, function pointer signing is currently performed in `get_fn_addr`, which causes
+        // the logic to be applied too broadly, including to function values (not just pointers).
+        // As a result, direct calls using signed function values must also receive operand
+        // bundles.
+        // Once this is resolved, we should analyze each call and skip direct calls. See the
+        // discussion in the rust-lang issue: <https://github.com/rust-lang/rust/issues/152532>
+        let key: u32 = 0;
+        let discriminator: u64 = 0;
+        Some(llvm::OperandBundleBox::new(
+            "ptrauth",
+            &[self.const_u32(key), self.const_u64(discriminator)],
+        ))
+    }
+
     /// Emits a call to `llvm.instrprof.increment`. Used by coverage instrumentation.
     #[instrument(level = "debug", skip(self))]
     pub(crate) fn instrprof_increment(