Rollup of 6 pull requests

compiler/rustc_codegen_ssa/src/back/symbol_export.rs

@@ -363,6 +363,24 @@ fn exported_symbols_provider_local(
                         },
                     ));
                 }
+                MonoItem::Fn(Instance {
+                    def: InstanceDef::AsyncDropGlueCtorShim(def_id, ty),
+                    args,
+                }) => {
+                    // A little sanity-check
+                    debug_assert_eq!(
+                        args.non_erasable_generics(tcx, def_id).skip(1).next(),
+                        Some(GenericArgKind::Type(ty))
+                    );
+                    symbols.push((
+                        ExportedSymbol::AsyncDropGlueCtorShim(ty),
+                        SymbolExportInfo {
+                            level: SymbolExportLevel::Rust,
+                            kind: SymbolExportKind::Text,
+                            used: false,
+                        },
+                    ));
+                }
                 _ => {
                     // Any other symbols don't qualify for sharing
                 }
@@ -385,6 +403,7 @@ fn upstream_monomorphizations_provider(
     let mut instances: DefIdMap<UnordMap<_, _>> = Default::default();
 
     let drop_in_place_fn_def_id = tcx.lang_items().drop_in_place_fn();
+    let async_drop_in_place_fn_def_id = tcx.lang_items().async_drop_in_place_fn();
 
     for &cnum in cnums.iter() {
         for (exported_symbol, _) in tcx.exported_symbols(cnum).iter() {
@@ -399,6 +418,18 @@ fn upstream_monomorphizations_provider(
                         continue;
                     }
                 }
+                ExportedSymbol::AsyncDropGlueCtorShim(ty) => {
+                    if let Some(async_drop_in_place_fn_def_id) = async_drop_in_place_fn_def_id {
+                        (
+                            async_drop_in_place_fn_def_id,
+                            tcx.mk_args(&[tcx.lifetimes.re_erased.into(), ty.into()]),
+                        )
+                    } else {
+                        // `drop_in_place` in place does not exist, don't try
+                        // to use it.
+                        continue;
+                    }
+                }
                 ExportedSymbol::NonGeneric(..)
                 | ExportedSymbol::ThreadLocalShim(..)
                 | ExportedSymbol::NoDefId(..) => {
@@ -534,6 +565,13 @@ pub fn symbol_name_for_instance_in_crate<'tcx>(
             Instance::resolve_drop_in_place(tcx, ty),
             instantiating_crate,
         ),
+        ExportedSymbol::AsyncDropGlueCtorShim(ty) => {
+            rustc_symbol_mangling::symbol_name_for_instance_in_crate(
+                tcx,
+                Instance::resolve_async_drop_in_place(tcx, ty),
+                instantiating_crate,
+            )
+        }
         ExportedSymbol::NoDefId(symbol_name) => symbol_name.to_string(),
     }
 }
@@ -582,6 +620,9 @@ pub fn linking_symbol_name_for_instance_in_crate<'tcx>(
         // DropGlue always use the Rust calling convention and thus follow the target's default
         // symbol decoration scheme.
         ExportedSymbol::DropGlue(..) => None,
+        // AsyncDropGlueCtorShim always use the Rust calling convention and thus follow the
+        // target's default symbol decoration scheme.
+        ExportedSymbol::AsyncDropGlueCtorShim(..) => None,
         // NoDefId always follow the target's default symbol decoration scheme.
         ExportedSymbol::NoDefId(..) => None,
         // ThreadLocalShim always follow the target's default symbol decoration scheme.

compiler/rustc_const_eval/src/const_eval/eval_queries.rs

@@ -10,20 +10,21 @@ use rustc_middle::traits::Reveal;
 use rustc_middle::ty::layout::LayoutOf;
 use rustc_middle::ty::print::with_no_trimmed_paths;
 use rustc_middle::ty::{self, Ty, TyCtxt};
+use rustc_session::lint;
 use rustc_span::def_id::LocalDefId;
 use rustc_span::Span;
 use rustc_target::abi::{self, Abi};
 
 use super::{CanAccessMutGlobal, CompileTimeEvalContext, CompileTimeInterpreter};
 use crate::const_eval::CheckAlignment;
-use crate::errors;
 use crate::errors::ConstEvalError;
-use crate::interpret::eval_nullary_intrinsic;
+use crate::errors::{self, DanglingPtrInFinal};
 use crate::interpret::{
     create_static_alloc, intern_const_alloc_recursive, CtfeValidationMode, GlobalId, Immediate,
     InternKind, InterpCx, InterpError, InterpResult, MPlaceTy, MemoryKind, OpTy, RefTracking,
     StackPopCleanup,
 };
+use crate::interpret::{eval_nullary_intrinsic, InternResult};
 use crate::CTRL_C_RECEIVED;
 
 // Returns a pointer to where the result lives
@@ -89,11 +90,35 @@ fn eval_body_using_ecx<'mir, 'tcx, R: InterpretationResult<'tcx>>(
     }
 
     // Intern the result
-    intern_const_alloc_recursive(ecx, intern_kind, &ret)?;
+    let intern_result = intern_const_alloc_recursive(ecx, intern_kind, &ret);
 
     // Since evaluation had no errors, validate the resulting constant.
     const_validate_mplace(&ecx, &ret, cid)?;
 
+    // Only report this after validation, as validaiton produces much better diagnostics.
+    // FIXME: ensure validation always reports this and stop making interning care about it.
+
+    match intern_result {
+        Ok(()) => {}
+        Err(InternResult::FoundDanglingPointer) => {
+            return Err(ecx
+                .tcx
+                .dcx()
+                .emit_err(DanglingPtrInFinal { span: ecx.tcx.span, kind: intern_kind })
+                .into());
+        }
+        Err(InternResult::FoundBadMutablePointer) => {
+            // only report mutable pointers if there were no dangling pointers
+            let err_diag = errors::MutablePtrInFinal { span: ecx.tcx.span, kind: intern_kind };
+            ecx.tcx.emit_node_span_lint(
+                lint::builtin::CONST_EVAL_MUTABLE_PTR_IN_FINAL_VALUE,
+                ecx.best_lint_scope(),
+                err_diag.span,
+                err_diag,
+            )
+        }
+    }
+
     Ok(R::make_result(ret, ecx))
 }
 

compiler/rustc_const_eval/src/interpret/intern.rs

@@ -16,19 +16,17 @@
 use hir::def::DefKind;
 use rustc_ast::Mutability;
 use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
-use rustc_errors::ErrorGuaranteed;
 use rustc_hir as hir;
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrs;
 use rustc_middle::mir::interpret::{ConstAllocation, CtfeProvenance, InterpResult};
 use rustc_middle::query::TyCtxtAt;
 use rustc_middle::ty::layout::TyAndLayout;
-use rustc_session::lint;
 use rustc_span::def_id::LocalDefId;
 use rustc_span::sym;
 
 use super::{AllocId, Allocation, InterpCx, MPlaceTy, Machine, MemoryKind, PlaceTy};
 use crate::const_eval;
-use crate::errors::{DanglingPtrInFinal, MutablePtrInFinal, NestedStaticInThreadLocal};
+use crate::errors::NestedStaticInThreadLocal;
 
 pub trait CompileTimeMachine<'mir, 'tcx: 'mir, T> = Machine<
         'mir,
@@ -134,6 +132,12 @@ pub enum InternKind {
     Promoted,
 }
 
+#[derive(Debug)]
+pub enum InternResult {
+    FoundBadMutablePointer,
+    FoundDanglingPointer,
+}
+
 /// Intern `ret` and everything it references.
 ///
 /// This *cannot raise an interpreter error*. Doing so is left to validation, which
@@ -149,7 +153,7 @@ pub fn intern_const_alloc_recursive<
     ecx: &mut InterpCx<'mir, 'tcx, M>,
     intern_kind: InternKind,
     ret: &MPlaceTy<'tcx>,
-) -> Result<(), ErrorGuaranteed> {
+) -> Result<(), InternResult> {
     // We are interning recursively, and for mutability we are distinguishing the "root" allocation
     // that we are starting in, and all other allocations that we are encountering recursively.
     let (base_mutability, inner_mutability, is_static) = match intern_kind {
@@ -201,7 +205,7 @@ pub fn intern_const_alloc_recursive<
     // Whether we encountered a bad mutable pointer.
     // We want to first report "dangling" and then "mutable", so we need to delay reporting these
     // errors.
-    let mut found_bad_mutable_pointer = false;
+    let mut result = Ok(());
 
     // Keep interning as long as there are things to intern.
     // We show errors if there are dangling pointers, or mutable pointers in immutable contexts
@@ -251,7 +255,10 @@ pub fn intern_const_alloc_recursive<
             // on the promotion analysis not screwing up to ensure that it is sound to intern
             // promoteds as immutable.
             trace!("found bad mutable pointer");
-            found_bad_mutable_pointer = true;
+            // Prefer dangling pointer errors over mutable pointer errors
+            if result.is_ok() {
+                result = Err(InternResult::FoundBadMutablePointer);
+            }
         }
         if ecx.tcx.try_get_global_alloc(alloc_id).is_some() {
             // Already interned.
@@ -269,21 +276,15 @@ pub fn intern_const_alloc_recursive<
         // pointers before deciding which allocations can be made immutable; but for now we are
         // okay with losing some potential for immutability here. This can anyway only affect
         // `static mut`.
-        todo.extend(intern_shallow(ecx, alloc_id, inner_mutability).map_err(|()| {
-            ecx.tcx.dcx().emit_err(DanglingPtrInFinal { span: ecx.tcx.span, kind: intern_kind })
-        })?);
-    }
-    if found_bad_mutable_pointer {
-        let err_diag = MutablePtrInFinal { span: ecx.tcx.span, kind: intern_kind };
-        ecx.tcx.emit_node_span_lint(
-            lint::builtin::CONST_EVAL_MUTABLE_PTR_IN_FINAL_VALUE,
-            ecx.best_lint_scope(),
-            err_diag.span,
-            err_diag,
-        )
+        match intern_shallow(ecx, alloc_id, inner_mutability) {
+            Ok(nested) => todo.extend(nested),
+            Err(()) => {
+                ecx.tcx.dcx().delayed_bug("found dangling pointer during const interning");
+                result = Err(InternResult::FoundDanglingPointer);
+            }
+        }
     }
-
-    Ok(())
+    result
 }
 
 /// Intern `ret`. This function assumes that `ret` references no other allocation.

compiler/rustc_const_eval/src/interpret/machine.rs

@@ -288,28 +288,19 @@ pub trait Machine<'mir, 'tcx: 'mir>: Sized {
     }
 
     /// Return the `AllocId` for the given thread-local static in the current thread.
-    fn thread_local_static_base_pointer(
+    fn thread_local_static_pointer(
         _ecx: &mut InterpCx<'mir, 'tcx, Self>,
         def_id: DefId,
     ) -> InterpResult<'tcx, Pointer<Self::Provenance>> {
         throw_unsup!(ThreadLocalStatic(def_id))
     }
 
-    /// Return the root pointer for the given `extern static`.
-    fn extern_static_base_pointer(
+    /// Return the `AllocId` for the given `extern static`.
+    fn extern_static_pointer(
         ecx: &InterpCx<'mir, 'tcx, Self>,
         def_id: DefId,
     ) -> InterpResult<'tcx, Pointer<Self::Provenance>>;
 
-    /// Return a "base" pointer for the given allocation: the one that is used for direct
-    /// accesses to this static/const/fn allocation, or the one returned from the heap allocator.
-    ///
-    /// Not called on `extern` or thread-local statics (those use the methods above).
-    fn adjust_alloc_base_pointer(
-        ecx: &InterpCx<'mir, 'tcx, Self>,
-        ptr: Pointer,
-    ) -> InterpResult<'tcx, Pointer<Self::Provenance>>;
-
     /// "Int-to-pointer cast"
     fn ptr_from_addr_cast(
         ecx: &InterpCx<'mir, 'tcx, Self>,
@@ -336,6 +327,8 @@ pub trait Machine<'mir, 'tcx: 'mir>: Sized {
 
     /// Called to adjust allocations to the Provenance and AllocExtra of this machine.
     ///
+    /// If `alloc` contains pointers, then they are all pointing to globals.
+    ///
     /// The way we construct allocations is to always first construct it without extra and then add
     /// the extra. This keeps uniform code paths for handling both allocations created by CTFE for
     /// globals, and allocations created by Miri during evaluation.
@@ -354,6 +347,19 @@ pub trait Machine<'mir, 'tcx: 'mir>: Sized {
         kind: Option<MemoryKind<Self::MemoryKind>>,
     ) -> InterpResult<'tcx, Cow<'b, Allocation<Self::Provenance, Self::AllocExtra, Self::Bytes>>>;
 
+    /// Return a "root" pointer for the given allocation: the one that is used for direct
+    /// accesses to this static/const/fn allocation, or the one returned from the heap allocator.
+    ///
+    /// Not called on `extern` or thread-local statics (those use the methods above).
+    ///
+    /// `kind` is the kind of the allocation the pointer points to; it can be `None` when
+    /// it's a global and `GLOBAL_KIND` is `None`.
+    fn adjust_alloc_root_pointer(
+        ecx: &InterpCx<'mir, 'tcx, Self>,
+        ptr: Pointer,
+        kind: Option<MemoryKind<Self::MemoryKind>>,
+    ) -> InterpResult<'tcx, Pointer<Self::Provenance>>;
+
     /// Evaluate the inline assembly.
     ///
     /// This should take care of jumping to the next block (one of `targets`) when asm goto
@@ -592,7 +598,7 @@ pub macro compile_time_machine(<$mir: lifetime, $tcx: lifetime>) {
         Ok(alloc)
     }
 
-    fn extern_static_base_pointer(
+    fn extern_static_pointer(
         ecx: &InterpCx<$mir, $tcx, Self>,
         def_id: DefId,
     ) -> InterpResult<$tcx, Pointer> {
@@ -601,9 +607,10 @@ pub macro compile_time_machine(<$mir: lifetime, $tcx: lifetime>) {
     }
 
     #[inline(always)]
-    fn adjust_alloc_base_pointer(
+    fn adjust_alloc_root_pointer(
         _ecx: &InterpCx<$mir, $tcx, Self>,
         ptr: Pointer<CtfeProvenance>,
+        _kind: Option<MemoryKind<Self::MemoryKind>>,
     ) -> InterpResult<$tcx, Pointer<CtfeProvenance>> {
         Ok(ptr)
     }

compiler/rustc_const_eval/src/interpret/memory.rs

@@ -165,7 +165,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
     ///
     /// This function can fail only if `ptr` points to an `extern static`.
     #[inline]
-    pub fn global_base_pointer(
+    pub fn global_root_pointer(
         &self,
         ptr: Pointer<CtfeProvenance>,
     ) -> InterpResult<'tcx, Pointer<M::Provenance>> {
@@ -178,12 +178,18 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 bug!("global memory cannot point to thread-local static")
             }
             Some(GlobalAlloc::Static(def_id)) if self.tcx.is_foreign_item(def_id) => {
-                return M::extern_static_base_pointer(self, def_id);
+                return M::extern_static_pointer(self, def_id);
+            }
+            None => {
+                assert!(
+                    self.memory.extra_fn_ptr_map.contains_key(&alloc_id),
+                    "{alloc_id:?} is neither global nor a function pointer"
+                );
             }
             _ => {}
         }
         // And we need to get the provenance.
-        M::adjust_alloc_base_pointer(self, ptr)
+        M::adjust_alloc_root_pointer(self, ptr, M::GLOBAL_KIND.map(MemoryKind::Machine))
     }
 
     pub fn fn_ptr(&mut self, fn_val: FnVal<'tcx, M::ExtraFnVal>) -> Pointer<M::Provenance> {
@@ -197,9 +203,9 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 id
             }
         };
-        // Functions are global allocations, so make sure we get the right base pointer.
+        // Functions are global allocations, so make sure we get the right root pointer.
         // We know this is not an `extern static` so this cannot fail.
-        self.global_base_pointer(Pointer::from(id)).unwrap()
+        self.global_root_pointer(Pointer::from(id)).unwrap()
     }
 
     pub fn allocate_ptr(
@@ -240,7 +246,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         );
         let alloc = M::adjust_allocation(self, id, Cow::Owned(alloc), Some(kind))?;
         self.memory.alloc_map.insert(id, (kind, alloc.into_owned()));
-        M::adjust_alloc_base_pointer(self, Pointer::from(id))
+        M::adjust_alloc_root_pointer(self, Pointer::from(id), Some(kind))
     }
 
     pub fn reallocate_ptr(

compiler/rustc_const_eval/src/interpret/mod.rs

@@ -23,6 +23,7 @@ pub use rustc_middle::mir::interpret::*; // have all the `interpret` symbols in
 pub use self::eval_context::{format_interp_error, Frame, FrameInfo, InterpCx, StackPopCleanup};
 pub use self::intern::{
     intern_const_alloc_for_constprop, intern_const_alloc_recursive, HasStaticRootDefId, InternKind,
+    InternResult,
 };
 pub use self::machine::{compile_time_machine, AllocMap, Machine, MayLeak, StackPopJump};
 pub use self::memory::{AllocKind, AllocRef, AllocRefMut, FnVal, Memory, MemoryKind};

compiler/rustc_const_eval/src/interpret/operand.rs

@@ -764,15 +764,15 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         // Other cases need layout.
         let adjust_scalar = |scalar| -> InterpResult<'tcx, _> {
             Ok(match scalar {
-                Scalar::Ptr(ptr, size) => Scalar::Ptr(self.global_base_pointer(ptr)?, size),
+                Scalar::Ptr(ptr, size) => Scalar::Ptr(self.global_root_pointer(ptr)?, size),
                 Scalar::Int(int) => Scalar::Int(int),
             })
         };
         let layout = from_known_layout(self.tcx, self.param_env, layout, || self.layout_of(ty))?;
         let imm = match val_val {
             mir::ConstValue::Indirect { alloc_id, offset } => {
                 // This is const data, no mutation allowed.
-                let ptr = self.global_base_pointer(Pointer::new(
+                let ptr = self.global_root_pointer(Pointer::new(
                     CtfeProvenance::from(alloc_id).as_immutable(),
                     offset,
                 ))?;
@@ -784,7 +784,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 // This is const data, no mutation allowed.
                 let alloc_id = self.tcx.reserve_and_set_memory_alloc(data);
                 let ptr = Pointer::new(CtfeProvenance::from(alloc_id).as_immutable(), Size::ZERO);
-                Immediate::new_slice(self.global_base_pointer(ptr)?.into(), meta, self)
+                Immediate::new_slice(self.global_root_pointer(ptr)?.into(), meta, self)
             }
         };
         Ok(OpTy { op: Operand::Immediate(imm), layout })