Trait Machine

pub trait Machine<'tcx>: Sized {
    type MemoryKind: Debug + Display + MayLeak + Eq + 'static;
    type Provenance: Provenance + Eq + Hash + 'static;
    type ProvenanceExtra: Copy + 'static;
    type ExtraFnVal: Debug + Copy;
    type FrameExtra;
    type AllocExtra: Debug + Clone + 'tcx;
    type Bytes: AllocBytes + 'static;
    type MemoryMap: AllocMap<AllocId, (MemoryKind<Self::MemoryKind>, Allocation<Self::Provenance, Self::AllocExtra, Self::Bytes>)> + Default + Clone;

    const GLOBAL_KIND: Option<Self::MemoryKind>;
    const PANIC_ON_ALLOC_FAIL: bool;
    const ALL_CONSTS_ARE_PRECHECKED: bool = true;

    // Required methods
    fn enforce_alignment(ecx: &InterpCx<'tcx, Self>) -> bool;
    fn enforce_validity(
        ecx: &InterpCx<'tcx, Self>,
        layout: TyAndLayout<'tcx>,
    ) -> bool;
    fn ignore_optional_overflow_checks(_ecx: &InterpCx<'tcx, Self>) -> bool;
    fn find_mir_or_eval_fn(
        ecx: &mut InterpCx<'tcx, Self>,
        instance: Instance<'tcx>,
        abi: CallAbi,
        args: &[FnArg<'tcx, Self::Provenance>],
        destination: &MPlaceTy<'tcx, Self::Provenance>,
        target: Option<BasicBlock>,
        unwind: UnwindAction,
    ) -> InterpResult<'tcx, Option<(&'tcx Body<'tcx>, Instance<'tcx>)>>;
    fn call_extra_fn(
        ecx: &mut InterpCx<'tcx, Self>,
        fn_val: Self::ExtraFnVal,
        abi: CallAbi,
        args: &[FnArg<'tcx, Self::Provenance>],
        destination: &MPlaceTy<'tcx, Self::Provenance>,
        target: Option<BasicBlock>,
        unwind: UnwindAction,
    ) -> InterpResult<'tcx>;
    fn call_intrinsic(
        ecx: &mut InterpCx<'tcx, Self>,
        instance: Instance<'tcx>,
        args: &[OpTy<'tcx, Self::Provenance>],
        destination: &MPlaceTy<'tcx, Self::Provenance>,
        target: Option<BasicBlock>,
        unwind: UnwindAction,
    ) -> InterpResult<'tcx, Option<Instance<'tcx>>>;
    fn check_fn_target_features(
        _ecx: &InterpCx<'tcx, Self>,
        _instance: Instance<'tcx>,
    ) -> InterpResult<'tcx>;
    fn assert_panic(
        ecx: &mut InterpCx<'tcx, Self>,
        msg: &AssertMessage<'tcx>,
        unwind: UnwindAction,
    ) -> InterpResult<'tcx>;
    fn panic_nounwind(
        _ecx: &mut InterpCx<'tcx, Self>,
        msg: &str,
    ) -> InterpResult<'tcx>;
    fn unwind_terminate(
        ecx: &mut InterpCx<'tcx, Self>,
        reason: UnwindTerminateReason,
    ) -> InterpResult<'tcx>;
    fn binary_ptr_op(
        ecx: &InterpCx<'tcx, Self>,
        bin_op: BinOp,
        left: &ImmTy<'tcx, Self::Provenance>,
        right: &ImmTy<'tcx, Self::Provenance>,
    ) -> InterpResult<'tcx, ImmTy<'tcx, Self::Provenance>>;
    fn ub_checks(_ecx: &InterpCx<'tcx, Self>) -> InterpResult<'tcx, bool>;
    fn extern_static_pointer(
        ecx: &InterpCx<'tcx, Self>,
        def_id: DefId,
    ) -> InterpResult<'tcx, Pointer<Self::Provenance>>;
    fn ptr_from_addr_cast(
        ecx: &InterpCx<'tcx, Self>,
        addr: u64,
    ) -> InterpResult<'tcx, Pointer<Option<Self::Provenance>>>;
    fn expose_ptr(
        ecx: &mut InterpCx<'tcx, Self>,
        ptr: Pointer<Self::Provenance>,
    ) -> InterpResult<'tcx>;
    fn ptr_get_alloc(
        ecx: &InterpCx<'tcx, Self>,
        ptr: Pointer<Self::Provenance>,
        size: i64,
    ) -> Option<(AllocId, Size, Self::ProvenanceExtra)>;
    fn adjust_global_allocation<'b>(
        ecx: &InterpCx<'tcx, Self>,
        id: AllocId,
        alloc: &'b Allocation,
    ) -> InterpResult<'tcx, Cow<'b, Allocation<Self::Provenance, Self::AllocExtra, Self::Bytes>>>;
    fn init_alloc_extra(
        ecx: &InterpCx<'tcx, Self>,
        id: AllocId,
        kind: MemoryKind<Self::MemoryKind>,
        size: Size,
        align: Align,
    ) -> InterpResult<'tcx, Self::AllocExtra>;
    fn adjust_alloc_root_pointer(
        ecx: &InterpCx<'tcx, Self>,
        ptr: Pointer,
        kind: Option<MemoryKind<Self::MemoryKind>>,
    ) -> InterpResult<'tcx, Pointer<Self::Provenance>>;
    fn init_frame(
        ecx: &mut InterpCx<'tcx, Self>,
        frame: Frame<'tcx, Self::Provenance>,
    ) -> InterpResult<'tcx, Frame<'tcx, Self::Provenance, Self::FrameExtra>>;
    fn stack<'a>(
        ecx: &'a InterpCx<'tcx, Self>,
    ) -> &'a [Frame<'tcx, Self::Provenance, Self::FrameExtra>];
    fn stack_mut<'a>(
        ecx: &'a mut InterpCx<'tcx, Self>,
    ) -> &'a mut Vec<Frame<'tcx, Self::Provenance, Self::FrameExtra>>;
    fn get_global_alloc_salt(
        ecx: &InterpCx<'tcx, Self>,
        instance: Option<Instance<'tcx>>,
    ) -> usize;

    // Provided methods
    fn alignment_check(
        _ecx: &InterpCx<'tcx, Self>,
        _alloc_id: AllocId,
        _alloc_align: Align,
        _alloc_kind: AllocKind,
        _offset: Size,
        _align: Align,
    ) -> Option<Misalignment> { ... }
    fn enforce_validity_recursively(
        _ecx: &InterpCx<'tcx, Self>,
        _layout: TyAndLayout<'tcx>,
    ) -> bool { ... }
    fn load_mir(
        ecx: &InterpCx<'tcx, Self>,
        instance: InstanceKind<'tcx>,
    ) -> InterpResult<'tcx, &'tcx Body<'tcx>> { ... }
    fn generate_nan<F1: Float + FloatConvert<F2>, F2: Float>(
        _ecx: &InterpCx<'tcx, Self>,
        _inputs: &[F1],
    ) -> F2 { ... }
    fn before_terminator(_ecx: &mut InterpCx<'tcx, Self>) -> InterpResult<'tcx> { ... }
    fn increment_const_eval_counter(
        _ecx: &mut InterpCx<'tcx, Self>,
    ) -> InterpResult<'tcx> { ... }
    fn before_access_global(
        _tcx: TyCtxtAt<'tcx>,
        _machine: &Self,
        _alloc_id: AllocId,
        _allocation: ConstAllocation<'tcx>,
        _static_def_id: Option<DefId>,
        _is_write: bool,
    ) -> InterpResult<'tcx> { ... }
    fn thread_local_static_pointer(
        _ecx: &mut InterpCx<'tcx, Self>,
        def_id: DefId,
    ) -> InterpResult<'tcx, Pointer<Self::Provenance>> { ... }
    fn eval_inline_asm(
        _ecx: &mut InterpCx<'tcx, Self>,
        _template: &'tcx [InlineAsmTemplatePiece],
        _operands: &[InlineAsmOperand<'tcx>],
        _options: InlineAsmOptions,
        _targets: &[BasicBlock],
    ) -> InterpResult<'tcx> { ... }
    fn before_memory_read(
        _tcx: TyCtxtAt<'tcx>,
        _machine: &Self,
        _alloc_extra: &Self::AllocExtra,
        _prov: (AllocId, Self::ProvenanceExtra),
        _range: AllocRange,
    ) -> InterpResult<'tcx> { ... }
    fn before_alloc_read(
        _ecx: &InterpCx<'tcx, Self>,
        _alloc_id: AllocId,
    ) -> InterpResult<'tcx> { ... }
    fn before_memory_write(
        _tcx: TyCtxtAt<'tcx>,
        _machine: &mut Self,
        _alloc_extra: &mut Self::AllocExtra,
        _prov: (AllocId, Self::ProvenanceExtra),
        _range: AllocRange,
    ) -> InterpResult<'tcx> { ... }
    fn before_memory_deallocation(
        _tcx: TyCtxtAt<'tcx>,
        _machine: &mut Self,
        _alloc_extra: &mut Self::AllocExtra,
        _prov: (AllocId, Self::ProvenanceExtra),
        _size: Size,
        _align: Align,
        _kind: MemoryKind<Self::MemoryKind>,
    ) -> InterpResult<'tcx> { ... }
    fn retag_ptr_value(
        _ecx: &mut InterpCx<'tcx, Self>,
        _kind: RetagKind,
        val: &ImmTy<'tcx, Self::Provenance>,
    ) -> InterpResult<'tcx, ImmTy<'tcx, Self::Provenance>> { ... }
    fn retag_place_contents(
        _ecx: &mut InterpCx<'tcx, Self>,
        _kind: RetagKind,
        _place: &PlaceTy<'tcx, Self::Provenance>,
    ) -> InterpResult<'tcx> { ... }
    fn protect_in_place_function_argument(
        ecx: &mut InterpCx<'tcx, Self>,
        mplace: &MPlaceTy<'tcx, Self::Provenance>,
    ) -> InterpResult<'tcx> { ... }
    fn after_stack_push(_ecx: &mut InterpCx<'tcx, Self>) -> InterpResult<'tcx> { ... }
    fn before_stack_pop(
        _ecx: &InterpCx<'tcx, Self>,
        _frame: &Frame<'tcx, Self::Provenance, Self::FrameExtra>,
    ) -> InterpResult<'tcx> { ... }
    fn after_stack_pop(
        _ecx: &mut InterpCx<'tcx, Self>,
        _frame: Frame<'tcx, Self::Provenance, Self::FrameExtra>,
        unwinding: bool,
    ) -> InterpResult<'tcx, ReturnAction> { ... }
    fn after_local_read(
        _ecx: &InterpCx<'tcx, Self>,
        _local: Local,
    ) -> InterpResult<'tcx> { ... }
    fn after_local_write(
        _ecx: &mut InterpCx<'tcx, Self>,
        _local: Local,
        _storage_live: bool,
    ) -> InterpResult<'tcx> { ... }
    fn after_local_moved_to_memory(
        _ecx: &mut InterpCx<'tcx, Self>,
        _local: Local,
        _mplace: &MPlaceTy<'tcx, Self::Provenance>,
    ) -> InterpResult<'tcx> { ... }
    fn eval_mir_constant<F>(
        ecx: &InterpCx<'tcx, Self>,
        val: Const<'tcx>,
        span: Span,
        layout: Option<TyAndLayout<'tcx>>,
        eval: F,
    ) -> InterpResult<'tcx, OpTy<'tcx, Self::Provenance>>
       where F: Fn(&InterpCx<'tcx, Self>, Const<'tcx>, Span, Option<TyAndLayout<'tcx>>) -> InterpResult<'tcx, OpTy<'tcx, Self::Provenance>> { ... }
    fn cached_union_data_range<'e>(
        _ecx: &'e mut InterpCx<'tcx, Self>,
        _ty: Ty<'tcx>,
        compute_range: impl FnOnce() -> RangeSet,
    ) -> Cow<'e, RangeSet> { ... }
}

Methods of this trait signifies a point where CTFE evaluation would fail and some use case dependent behaviour can instead be applied.

Required Associated Constants

const GLOBAL_KIND: Option<Self::MemoryKind>

The memory kind to use for copied global memory (held in tcx) – or None if such memory should not be mutated and thus any such attempt will cause a ModifiedStatic error to be raised. Statics are copied under two circumstances: When they are mutated, and when adjust_allocation (see below) returns an owned allocation that is added to the memory so that the work is not done twice.

const PANIC_ON_ALLOC_FAIL: bool

Should the machine panic on allocation failures?

Provided Associated Constants

const ALL_CONSTS_ARE_PRECHECKED: bool = true

Determines whether eval_mir_constant can never fail because all required consts have already been checked before.

Required Associated Types

type MemoryKind: Debug + Display + MayLeak + Eq + 'static

Additional memory kinds a machine wishes to distinguish from the builtin ones

type Provenance: Provenance + Eq + Hash + 'static

Pointers are “tagged” with provenance information; typically the AllocId they belong to.

type ProvenanceExtra: Copy + 'static

When getting the AllocId of a pointer, some extra data is also obtained from the provenance that is passed to memory access hooks so they can do things with it.

type ExtraFnVal: Debug + Copy

Machines can define extra (non-instance) things that represent values of function pointers. For example, Miri uses this to return a function pointer from dlsym that can later be called to execute the right thing.

type FrameExtra

Extra data stored in every call frame.

type AllocExtra: Debug + Clone + 'tcx

Extra data stored in every allocation.

type Bytes: AllocBytes + 'static

Type for the bytes of the allocation.

type MemoryMap: AllocMap<AllocId, (MemoryKind<Self::MemoryKind>, Allocation<Self::Provenance, Self::AllocExtra, Self::Bytes>)> + Default + Clone

Memory’s allocation map

Required Methods

fn enforce_alignment(ecx: &InterpCx<'tcx, Self>) -> bool

Whether memory accesses should be alignment-checked.

fn enforce_validity( ecx: &InterpCx<'tcx, Self>, layout: TyAndLayout<'tcx>, ) -> bool

Whether to enforce the validity invariant for a specific layout.

fn ignore_optional_overflow_checks(_ecx: &InterpCx<'tcx, Self>) -> bool

Whether Assert(OverflowNeg) and Assert(Overflow) MIR terminators should actually check for overflow.

fn find_mir_or_eval_fn( ecx: &mut InterpCx<'tcx, Self>, instance: Instance<'tcx>, abi: CallAbi, args: &[FnArg<'tcx, Self::Provenance>], destination: &MPlaceTy<'tcx, Self::Provenance>, target: Option<BasicBlock>, unwind: UnwindAction, ) -> InterpResult<'tcx, Option<(&'tcx Body<'tcx>, Instance<'tcx>)>>

Entry point to all function calls.

Returns either the mir to use for the call, or None if execution should just proceed (which usually means this hook did all the work that the called function should usually have done). In the latter case, it is this hook’s responsibility to advance the instruction pointer! (This is to support functions like __rust_maybe_catch_panic that neither find a MIR nor just jump to ret, but instead push their own stack frame.) Passing destand ret in the same Option proved very annoying when only one of them was used.

fn call_extra_fn( ecx: &mut InterpCx<'tcx, Self>, fn_val: Self::ExtraFnVal, abi: CallAbi, args: &[FnArg<'tcx, Self::Provenance>], destination: &MPlaceTy<'tcx, Self::Provenance>, target: Option<BasicBlock>, unwind: UnwindAction, ) -> InterpResult<'tcx>

Execute fn_val. It is the hook’s responsibility to advance the instruction pointer as appropriate.

fn call_intrinsic( ecx: &mut InterpCx<'tcx, Self>, instance: Instance<'tcx>, args: &[OpTy<'tcx, Self::Provenance>], destination: &MPlaceTy<'tcx, Self::Provenance>, target: Option<BasicBlock>, unwind: UnwindAction, ) -> InterpResult<'tcx, Option<Instance<'tcx>>>

Directly process an intrinsic without pushing a stack frame. It is the hook’s responsibility to advance the instruction pointer as appropriate.

Returns None if the intrinsic was fully handled. Otherwise, returns an Instance of the function that implements the intrinsic.

fn check_fn_target_features( _ecx: &InterpCx<'tcx, Self>, _instance: Instance<'tcx>, ) -> InterpResult<'tcx>

Check whether the given function may be executed on the current machine, in terms of the target features is requires.

fn assert_panic( ecx: &mut InterpCx<'tcx, Self>, msg: &AssertMessage<'tcx>, unwind: UnwindAction, ) -> InterpResult<'tcx>

Called to evaluate Assert MIR terminators that trigger a panic.

fn panic_nounwind( _ecx: &mut InterpCx<'tcx, Self>, msg: &str, ) -> InterpResult<'tcx>

Called to trigger a non-unwinding panic.

fn unwind_terminate( ecx: &mut InterpCx<'tcx, Self>, reason: UnwindTerminateReason, ) -> InterpResult<'tcx>

Called when unwinding reached a state where execution should be terminated.

fn binary_ptr_op( ecx: &InterpCx<'tcx, Self>, bin_op: BinOp, left: &ImmTy<'tcx, Self::Provenance>, right: &ImmTy<'tcx, Self::Provenance>, ) -> InterpResult<'tcx, ImmTy<'tcx, Self::Provenance>>

Called for all binary operations where the LHS has pointer type.

Returns a (value, overflowed) pair if the operation succeeded

fn ub_checks(_ecx: &InterpCx<'tcx, Self>) -> InterpResult<'tcx, bool>

Determines the result of a NullaryOp::UbChecks invocation.

fn extern_static_pointer( ecx: &InterpCx<'tcx, Self>, def_id: DefId, ) -> InterpResult<'tcx, Pointer<Self::Provenance>>

Return the AllocId for the given extern static.

fn ptr_from_addr_cast( ecx: &InterpCx<'tcx, Self>, addr: u64, ) -> InterpResult<'tcx, Pointer<Option<Self::Provenance>>>

“Int-to-pointer cast”

fn expose_ptr( ecx: &mut InterpCx<'tcx, Self>, ptr: Pointer<Self::Provenance>, ) -> InterpResult<'tcx>

Marks a pointer as exposed, allowing it’s provenance to be recovered. “Pointer-to-int cast”

fn ptr_get_alloc( ecx: &InterpCx<'tcx, Self>, ptr: Pointer<Self::Provenance>, size: i64, ) -> Option<(AllocId, Size, Self::ProvenanceExtra)>

Convert a pointer with provenance into an allocation-offset pair and extra provenance info. size says how many bytes of memory are expected at that pointer. The sign of size can be used to disambiguate situations where a wildcard pointer sits right in between two allocations.

If ptr.provenance.get_alloc_id() is Some(p), the returned AllocId must be p. The resulting AllocId will just be used for that one step and the forgotten again (i.e., we’ll never turn the data returned here back into a Pointer that might be stored in machine state).

When this fails, that means the pointer does not point to a live allocation.

fn adjust_global_allocation<'b>( ecx: &InterpCx<'tcx, Self>, id: AllocId, alloc: &'b Allocation, ) -> InterpResult<'tcx, Cow<'b, Allocation<Self::Provenance, Self::AllocExtra, Self::Bytes>>>

Called to adjust global allocations to the Provenance and AllocExtra of this machine.

If alloc contains pointers, then they are all pointing to globals.

This should avoid copying if no work has to be done! If this returns an owned allocation (because a copy had to be done to adjust things), machine memory will cache the result. (This relies on AllocMap::get_or being able to add the owned allocation to the map even when the map is shared.)

fn init_alloc_extra( ecx: &InterpCx<'tcx, Self>, id: AllocId, kind: MemoryKind<Self::MemoryKind>, size: Size, align: Align, ) -> InterpResult<'tcx, Self::AllocExtra>

Initialize the extra state of an allocation.

This is guaranteed to be called exactly once on all allocations that are accessed by the program.

fn adjust_alloc_root_pointer( ecx: &InterpCx<'tcx, Self>, ptr: Pointer, kind: Option<MemoryKind<Self::MemoryKind>>, ) -> InterpResult<'tcx, Pointer<Self::Provenance>>

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 init_frame( ecx: &mut InterpCx<'tcx, Self>, frame: Frame<'tcx, Self::Provenance>, ) -> InterpResult<'tcx, Frame<'tcx, Self::Provenance, Self::FrameExtra>>

Called immediately before a new stack frame gets pushed.

fn stack<'a>( ecx: &'a InterpCx<'tcx, Self>, ) -> &'a [Frame<'tcx, Self::Provenance, Self::FrameExtra>]

Borrow the current thread’s stack.

fn stack_mut<'a>( ecx: &'a mut InterpCx<'tcx, Self>, ) -> &'a mut Vec<Frame<'tcx, Self::Provenance, Self::FrameExtra>>

Mutably borrow the current thread’s stack.

fn get_global_alloc_salt( ecx: &InterpCx<'tcx, Self>, instance: Option<Instance<'tcx>>, ) -> usize

Returns the salt to be used for a deduplicated global alloation. If the allocation is for a function, the instance is provided as well (this lets Miri ensure unique addresses for some functions).

Provided Methods

fn alignment_check( _ecx: &InterpCx<'tcx, Self>, _alloc_id: AllocId, _alloc_align: Align, _alloc_kind: AllocKind, _offset: Size, _align: Align, ) -> Option<Misalignment>

Gives the machine a chance to detect more misalignment than the built-in checks would catch.

fn enforce_validity_recursively( _ecx: &InterpCx<'tcx, Self>, _layout: TyAndLayout<'tcx>, ) -> bool

Whether to enforce the validity invariant recursively.

fn load_mir( ecx: &InterpCx<'tcx, Self>, instance: InstanceKind<'tcx>, ) -> InterpResult<'tcx, &'tcx Body<'tcx>>

Entry point for obtaining the MIR of anything that should get evaluated. So not just functions and shims, but also const/static initializers, anonymous constants, …

fn generate_nan<F1: Float + FloatConvert<F2>, F2: Float>( _ecx: &InterpCx<'tcx, Self>, _inputs: &[F1], ) -> F2

Generate the NaN returned by a float operation, given the list of inputs. (This is all inputs, not just NaN inputs!)

fn before_terminator(_ecx: &mut InterpCx<'tcx, Self>) -> InterpResult<'tcx>

Called before a basic block terminator is executed.

fn increment_const_eval_counter( _ecx: &mut InterpCx<'tcx, Self>, ) -> InterpResult<'tcx>

Called when the interpreter encounters a StatementKind::ConstEvalCounter instruction. You can use this to detect long or endlessly running programs.

fn before_access_global( _tcx: TyCtxtAt<'tcx>, _machine: &Self, _alloc_id: AllocId, _allocation: ConstAllocation<'tcx>, _static_def_id: Option<DefId>, _is_write: bool, ) -> InterpResult<'tcx>

Called before a global allocation is accessed. def_id is Some if this is the “lazy” allocation of a static.

fn thread_local_static_pointer( _ecx: &mut InterpCx<'tcx, Self>, def_id: DefId, ) -> InterpResult<'tcx, Pointer<Self::Provenance>>

Return the AllocId for the given thread-local static in the current thread.

fn eval_inline_asm( _ecx: &mut InterpCx<'tcx, Self>, _template: &'tcx [InlineAsmTemplatePiece], _operands: &[InlineAsmOperand<'tcx>], _options: InlineAsmOptions, _targets: &[BasicBlock], ) -> InterpResult<'tcx>

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 before_memory_read( _tcx: TyCtxtAt<'tcx>, _machine: &Self, _alloc_extra: &Self::AllocExtra, _prov: (AllocId, Self::ProvenanceExtra), _range: AllocRange, ) -> InterpResult<'tcx>

Hook for performing extra checks on a memory read access.

This will not be called during validation!

Takes read-only access to the allocation so we can keep all the memory read operations take &self. Use a RefCell in AllocExtra if you need to mutate.

This is not invoked for ZST accesses, as no read actually happens.

fn before_alloc_read( _ecx: &InterpCx<'tcx, Self>, _alloc_id: AllocId, ) -> InterpResult<'tcx>

Hook for performing extra checks on any memory read access, that involves an allocation, even ZST reads.

This will not be called during validation!

Used to prevent statics from self-initializing by reading from their own memory as it is being initialized.

fn before_memory_write( _tcx: TyCtxtAt<'tcx>, _machine: &mut Self, _alloc_extra: &mut Self::AllocExtra, _prov: (AllocId, Self::ProvenanceExtra), _range: AllocRange, ) -> InterpResult<'tcx>

Hook for performing extra checks on a memory write access. This is not invoked for ZST accesses, as no write actually happens.

fn before_memory_deallocation( _tcx: TyCtxtAt<'tcx>, _machine: &mut Self, _alloc_extra: &mut Self::AllocExtra, _prov: (AllocId, Self::ProvenanceExtra), _size: Size, _align: Align, _kind: MemoryKind<Self::MemoryKind>, ) -> InterpResult<'tcx>

Hook for performing extra operations on a memory deallocation.

fn retag_ptr_value( _ecx: &mut InterpCx<'tcx, Self>, _kind: RetagKind, val: &ImmTy<'tcx, Self::Provenance>, ) -> InterpResult<'tcx, ImmTy<'tcx, Self::Provenance>>

Executes a retagging operation for a single pointer. Returns the possibly adjusted pointer.

fn retag_place_contents( _ecx: &mut InterpCx<'tcx, Self>, _kind: RetagKind, _place: &PlaceTy<'tcx, Self::Provenance>, ) -> InterpResult<'tcx>

Executes a retagging operation on a compound value. Replaces all pointers stored in the given place.

fn protect_in_place_function_argument( ecx: &mut InterpCx<'tcx, Self>, mplace: &MPlaceTy<'tcx, Self::Provenance>, ) -> InterpResult<'tcx>

Called on places used for in-place function argument and return value handling.

These places need to be protected to make sure the program cannot tell whether the argument/return value was actually copied or passed in-place..

fn after_stack_push(_ecx: &mut InterpCx<'tcx, Self>) -> InterpResult<'tcx>

Called immediately after a stack frame got pushed and its locals got initialized.

fn before_stack_pop( _ecx: &InterpCx<'tcx, Self>, _frame: &Frame<'tcx, Self::Provenance, Self::FrameExtra>, ) -> InterpResult<'tcx>

Called just before the return value is copied to the caller-provided return place.

fn after_stack_pop( _ecx: &mut InterpCx<'tcx, Self>, _frame: Frame<'tcx, Self::Provenance, Self::FrameExtra>, unwinding: bool, ) -> InterpResult<'tcx, ReturnAction>

Called immediately after a stack frame got popped, but before jumping back to the caller. The locals have already been destroyed!

fn after_local_read( _ecx: &InterpCx<'tcx, Self>, _local: Local, ) -> InterpResult<'tcx>

Called immediately after an “immediate” local variable is read (i.e., this is called for reads that do not end up accessing addressable memory).

fn after_local_write( _ecx: &mut InterpCx<'tcx, Self>, _local: Local, _storage_live: bool, ) -> InterpResult<'tcx>

Called immediately after an “immediate” local variable is assigned a new value (i.e., this is called for writes that do not end up in memory). storage_live indicates whether this is the initial write upon StorageLive.

fn after_local_moved_to_memory( _ecx: &mut InterpCx<'tcx, Self>, _local: Local, _mplace: &MPlaceTy<'tcx, Self::Provenance>, ) -> InterpResult<'tcx>

Called immediately after actual memory was allocated for a local but before the local’s stack frame is updated to point to that memory.

fn eval_mir_constant<F>( ecx: &InterpCx<'tcx, Self>, val: Const<'tcx>, span: Span, layout: Option<TyAndLayout<'tcx>>, eval: F, ) -> InterpResult<'tcx, OpTy<'tcx, Self::Provenance>>

where F: Fn(&InterpCx<'tcx, Self>, Const<'tcx>, Span, Option<TyAndLayout<'tcx>>) -> InterpResult<'tcx, OpTy<'tcx, Self::Provenance>>,

Evaluate the given constant. The eval function will do all the required evaluation, but this hook has the chance to do some pre/postprocessing.

fn cached_union_data_range<'e>( _ecx: &'e mut InterpCx<'tcx, Self>, _ty: Ty<'tcx>, compute_range: impl FnOnce() -> RangeSet, ) -> Cow<'e, RangeSet>

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl<'tcx> Machine<'tcx> for DummyMachine

const GLOBAL_KIND: Option<Self::MemoryKind> = None

const PANIC_ON_ALLOC_FAIL: bool = true

const ALL_CONSTS_ARE_PRECHECKED: bool = false

type Provenance = CtfeProvenance

type ProvenanceExtra = bool

type ExtraFnVal = !

type MemoryMap = IndexMap<AllocId, (MemoryKind<!>, Allocation), BuildHasherDefault<FxHasher>>

type AllocExtra = ()

type FrameExtra = ()

type Bytes = Box<[u8]>

type MemoryKind = !

impl<'tcx> Machine<'tcx> for CompileTimeMachine<'tcx>

const GLOBAL_KIND: Option<Self::MemoryKind> = None

const PANIC_ON_ALLOC_FAIL: bool = false

type Provenance = CtfeProvenance

type ProvenanceExtra = bool

type ExtraFnVal = !

type MemoryMap = IndexMap<AllocId, (MemoryKind<MemoryKind>, Allocation), BuildHasherDefault<FxHasher>>

type AllocExtra = ()

type FrameExtra = ()

type Bytes = Box<[u8]>

type MemoryKind = MemoryKind