Rollup merge of rust-lang#138417 - RalfJung:interpret-cleanup, r=oli-obk

minor interpreter cleanups

- remove the `eval_inline_asm` hook that `@saethlin` added; the usage never materialized and he agreed with removing it
- I tried merging `init_alloc_extra` and `adjust_global_allocation` and it didn't work; leave a comment as to why. Also, make the allocation code path a bit more clear by renaming `init_alloc_extra` to `init_local_allocation`.

r? `@oli-obk`

Author: matthiaskrgr

compiler/rustc_const_eval/src/interpret/machine.rs

@@ -8,7 +8,6 @@ use std::hash::Hash;
 
 use rustc_abi::{Align, Size};
 use rustc_apfloat::{Float, FloatConvert};
-use rustc_ast::{InlineAsmOptions, InlineAsmTemplatePiece};
 use rustc_middle::query::TyCtxtAt;
 use rustc_middle::ty::Ty;
 use rustc_middle::ty::layout::TyAndLayout;
@@ -21,7 +20,6 @@ use super::{
     AllocBytes, AllocId, AllocKind, AllocRange, Allocation, CTFE_ALLOC_SALT, ConstAllocation,
     CtfeProvenance, FnArg, Frame, ImmTy, InterpCx, InterpResult, MPlaceTy, MemoryKind,
     Misalignment, OpTy, PlaceTy, Pointer, Provenance, RangeSet, interp_ok, throw_unsup,
-    throw_unsup_format,
 };
 
 /// Data returned by [`Machine::after_stack_pop`], and consumed by
@@ -361,6 +359,19 @@ pub trait Machine<'tcx>: Sized {
         size: i64,
     ) -> Option<(AllocId, Size, Self::ProvenanceExtra)>;
 
+    /// 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<'tcx, Self>,
+        ptr: Pointer,
+        kind: Option<MemoryKind<Self::MemoryKind>>,
+    ) -> InterpResult<'tcx, Pointer<Self::Provenance>>;
+
     /// Called to adjust global allocations to the Provenance and AllocExtra of this machine.
     ///
     /// If `alloc` contains pointers, then they are all pointing to globals.
@@ -375,46 +386,19 @@ pub trait Machine<'tcx>: Sized {
         alloc: &'b Allocation,
     ) -> InterpResult<'tcx, Cow<'b, Allocation<Self::Provenance, Self::AllocExtra, Self::Bytes>>>;
 
-    /// Initialize the extra state of an allocation.
+    /// Initialize the extra state of an allocation local to this machine.
     ///
-    /// This is guaranteed to be called exactly once on all allocations that are accessed by the
-    /// program.
-    fn init_alloc_extra(
+    /// This is guaranteed to be called exactly once on all allocations local to this machine.
+    /// It will not be called automatically for global allocations; `adjust_global_allocation`
+    /// has to do that itself if that is desired.
+    fn init_local_allocation(
         ecx: &InterpCx<'tcx, Self>,
         id: AllocId,
         kind: MemoryKind<Self::MemoryKind>,
         size: Size,
         align: Align,
     ) -> InterpResult<'tcx, Self::AllocExtra>;
 
-    /// 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<'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
-    /// is triggered, `targets[0]` when the assembly falls through, or diverge in case of
-    /// naked_asm! or `InlineAsmOptions::NORETURN` being set.
-    fn eval_inline_asm(
-        _ecx: &mut InterpCx<'tcx, Self>,
-        _template: &'tcx [InlineAsmTemplatePiece],
-        _operands: &[mir::InlineAsmOperand<'tcx>],
-        _options: InlineAsmOptions,
-        _targets: &[mir::BasicBlock],
-    ) -> InterpResult<'tcx> {
-        throw_unsup_format!("inline assembly is not supported")
-    }
-
     /// Hook for performing extra checks on a memory read access.
     ///
     /// This will *not* be called during validation!
@@ -699,7 +683,7 @@ pub macro compile_time_machine(<$tcx: lifetime>) {
         interp_ok(Cow::Borrowed(alloc))
     }
 
-    fn init_alloc_extra(
+    fn init_local_allocation(
         _ecx: &InterpCx<$tcx, Self>,
         _id: AllocId,
         _kind: MemoryKind<Self::MemoryKind>,

compiler/rustc_const_eval/src/interpret/memory.rs

@@ -263,9 +263,9 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             M::GLOBAL_KIND.map(MemoryKind::Machine),
             "dynamically allocating global memory"
         );
-        // We have set things up so we don't need to call `adjust_from_tcx` here,
-        // so we avoid copying the entire allocation contents.
-        let extra = M::init_alloc_extra(self, id, kind, alloc.size(), alloc.align)?;
+        // This cannot be merged with the `adjust_global_allocation` code path
+        // since here we have an allocation that already uses `M::Bytes`.
+        let extra = M::init_local_allocation(self, id, kind, alloc.size(), alloc.align)?;
         let alloc = alloc.with_extra(extra);
         self.memory.alloc_map.insert(id, (kind, alloc));
         M::adjust_alloc_root_pointer(self, Pointer::from(id), Some(kind))

compiler/rustc_const_eval/src/interpret/step.rs

@@ -14,7 +14,7 @@ use tracing::{info, instrument, trace};
 
 use super::{
     FnArg, FnVal, ImmTy, Immediate, InterpCx, InterpResult, Machine, MemPlaceMeta, PlaceTy,
-    Projectable, Scalar, interp_ok, throw_ub,
+    Projectable, Scalar, interp_ok, throw_ub, throw_unsup_format,
 };
 use crate::util;
 
@@ -590,8 +590,8 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                 terminator.kind
             ),
 
-            InlineAsm { template, ref operands, options, ref targets, .. } => {
-                M::eval_inline_asm(self, template, operands, options, targets)?;
+            InlineAsm { .. } => {
+                throw_unsup_format!("inline assembly is not supported");
             }
         }
 

src/tools/miri/src/alloc_addresses/mod.rs

@@ -377,7 +377,6 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
     fn get_global_alloc_bytes(
         &self,
         id: AllocId,
-        kind: MemoryKind,
         bytes: &[u8],
         align: Align,
     ) -> InterpResult<'tcx, MiriAllocBytes> {
@@ -386,7 +385,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
             // In native lib mode, MiriAllocBytes for global allocations are handled via `prepared_alloc_bytes`.
             // This additional call ensures that some `MiriAllocBytes` are always prepared, just in case
             // this function gets called before the first time `addr_from_alloc_id` gets called.
-            this.addr_from_alloc_id(id, kind)?;
+            this.addr_from_alloc_id(id, MiriMemoryKind::Global.into())?;
             // The memory we need here will have already been allocated during an earlier call to
             // `addr_from_alloc_id` for this allocation. So don't create a new `MiriAllocBytes` here, instead
             // fetch the previously prepared bytes from `prepared_alloc_bytes`.

src/tools/miri/src/machine.rs

@@ -814,6 +814,59 @@ impl<'tcx> MiriMachine<'tcx> {
             .and_then(|(_allocated, deallocated)| *deallocated)
             .map(Span::data)
     }
+
+    fn init_allocation(
+        ecx: &MiriInterpCx<'tcx>,
+        id: AllocId,
+        kind: MemoryKind,
+        size: Size,
+        align: Align,
+    ) -> InterpResult<'tcx, AllocExtra<'tcx>> {
+        if ecx.machine.tracked_alloc_ids.contains(&id) {
+            ecx.emit_diagnostic(NonHaltingDiagnostic::CreatedAlloc(id, size, align, kind));
+        }
+
+        let borrow_tracker = ecx
+            .machine
+            .borrow_tracker
+            .as_ref()
+            .map(|bt| bt.borrow_mut().new_allocation(id, size, kind, &ecx.machine));
+
+        let data_race = ecx.machine.data_race.as_ref().map(|data_race| {
+            data_race::AllocState::new_allocation(
+                data_race,
+                &ecx.machine.threads,
+                size,
+                kind,
+                ecx.machine.current_span(),
+            )
+        });
+        let weak_memory = ecx.machine.weak_memory.then(weak_memory::AllocState::new_allocation);
+
+        // If an allocation is leaked, we want to report a backtrace to indicate where it was
+        // allocated. We don't need to record a backtrace for allocations which are allowed to
+        // leak.
+        let backtrace = if kind.may_leak() || !ecx.machine.collect_leak_backtraces {
+            None
+        } else {
+            Some(ecx.generate_stacktrace())
+        };
+
+        if matches!(kind, MemoryKind::Machine(kind) if kind.should_save_allocation_span()) {
+            ecx.machine
+                .allocation_spans
+                .borrow_mut()
+                .insert(id, (ecx.machine.current_span(), None));
+        }
+
+        interp_ok(AllocExtra {
+            borrow_tracker,
+            data_race,
+            weak_memory,
+            backtrace,
+            sync: FxHashMap::default(),
+        })
+    }
 }
 
 impl VisitProvenance for MiriMachine<'_> {
@@ -1200,57 +1253,15 @@ impl<'tcx> Machine<'tcx> for MiriMachine<'tcx> {
         }
     }
 
-    fn init_alloc_extra(
+    fn init_local_allocation(
         ecx: &MiriInterpCx<'tcx>,
         id: AllocId,
         kind: MemoryKind,
         size: Size,
         align: Align,
     ) -> InterpResult<'tcx, Self::AllocExtra> {
-        if ecx.machine.tracked_alloc_ids.contains(&id) {
-            ecx.emit_diagnostic(NonHaltingDiagnostic::CreatedAlloc(id, size, align, kind));
-        }
-
-        let borrow_tracker = ecx
-            .machine
-            .borrow_tracker
-            .as_ref()
-            .map(|bt| bt.borrow_mut().new_allocation(id, size, kind, &ecx.machine));
-
-        let data_race = ecx.machine.data_race.as_ref().map(|data_race| {
-            data_race::AllocState::new_allocation(
-                data_race,
-                &ecx.machine.threads,
-                size,
-                kind,
-                ecx.machine.current_span(),
-            )
-        });
-        let weak_memory = ecx.machine.weak_memory.then(weak_memory::AllocState::new_allocation);
-
-        // If an allocation is leaked, we want to report a backtrace to indicate where it was
-        // allocated. We don't need to record a backtrace for allocations which are allowed to
-        // leak.
-        let backtrace = if kind.may_leak() || !ecx.machine.collect_leak_backtraces {
-            None
-        } else {
-            Some(ecx.generate_stacktrace())
-        };
-
-        if matches!(kind, MemoryKind::Machine(kind) if kind.should_save_allocation_span()) {
-            ecx.machine
-                .allocation_spans
-                .borrow_mut()
-                .insert(id, (ecx.machine.current_span(), None));
-        }
-
-        interp_ok(AllocExtra {
-            borrow_tracker,
-            data_race,
-            weak_memory,
-            backtrace,
-            sync: FxHashMap::default(),
-        })
+        assert!(kind != MiriMemoryKind::Global.into());
+        MiriMachine::init_allocation(ecx, id, kind, size, align)
     }
 
     fn adjust_alloc_root_pointer(
@@ -1340,13 +1351,13 @@ impl<'tcx> Machine<'tcx> for MiriMachine<'tcx> {
         alloc: &'b Allocation,
     ) -> InterpResult<'tcx, Cow<'b, Allocation<Self::Provenance, Self::AllocExtra, Self::Bytes>>>
     {
-        let kind = Self::GLOBAL_KIND.unwrap().into();
         let alloc = alloc.adjust_from_tcx(
             &ecx.tcx,
-            |bytes, align| ecx.get_global_alloc_bytes(id, kind, bytes, align),
+            |bytes, align| ecx.get_global_alloc_bytes(id, bytes, align),
             |ptr| ecx.global_root_pointer(ptr),
         )?;
-        let extra = Self::init_alloc_extra(ecx, id, kind, alloc.size(), alloc.align)?;
+        let kind = MiriMemoryKind::Global.into();
+        let extra = MiriMachine::init_allocation(ecx, id, kind, alloc.size(), alloc.align)?;
         interp_ok(Cow::Owned(alloc.with_extra(extra)))
     }