Trait rustc_mir::interpret::Machine[−][src]

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

    const GLOBAL_KIND: Option<Self::MemoryKind>;

    fn enforce_alignment(memory_extra: &Self::MemoryExtra) -> bool;

    fn force_int_for_alignment_check(memory_extra: &Self::MemoryExtra) -> bool;

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

    fn find_mir_or_eval_fn(
        ecx: &mut InterpCx<'mir, 'tcx, Self>, 
        instance: Instance<'tcx>, 
        abi: Abi, 
        args: &[OpTy<'tcx, Self::PointerTag>], 
        ret: Option<(&PlaceTy<'tcx, Self::PointerTag>, BasicBlock)>, 
        unwind: Option<BasicBlock>
    ) -> InterpResult<'tcx, Option<&'mir Body<'tcx>>>;

    fn call_extra_fn(
        ecx: &mut InterpCx<'mir, 'tcx, Self>, 
        fn_val: Self::ExtraFnVal, 
        abi: Abi, 
        args: &[OpTy<'tcx, Self::PointerTag>], 
        ret: Option<(&PlaceTy<'tcx, Self::PointerTag>, BasicBlock)>, 
        unwind: Option<BasicBlock>
    ) -> InterpResult<'tcx>;

    fn call_intrinsic(
        ecx: &mut InterpCx<'mir, 'tcx, Self>, 
        instance: Instance<'tcx>, 
        args: &[OpTy<'tcx, Self::PointerTag>], 
        ret: Option<(&PlaceTy<'tcx, Self::PointerTag>, BasicBlock)>, 
        unwind: Option<BasicBlock>
    ) -> InterpResult<'tcx>;

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

    fn binary_ptr_op(
        ecx: &InterpCx<'mir, 'tcx, Self>, 
        bin_op: BinOp, 
        left: &ImmTy<'tcx, Self::PointerTag>, 
        right: &ImmTy<'tcx, Self::PointerTag>
    ) -> InterpResult<'tcx, (Scalar<Self::PointerTag>, bool, Ty<'tcx>)>;

    fn box_alloc(
        ecx: &mut InterpCx<'mir, 'tcx, Self>, 
        dest: &PlaceTy<'tcx, Self::PointerTag>
    ) -> InterpResult<'tcx>;

    fn tag_global_base_pointer(
        memory_extra: &Self::MemoryExtra, 
        id: AllocId
    ) -> Self::PointerTag;

    fn init_allocation_extra<'b>(
        memory_extra: &Self::MemoryExtra, 
        id: AllocId, 
        alloc: Cow<'b, Allocation>, 
        kind: Option<MemoryKind<Self::MemoryKind>>
    ) -> (Cow<'b, Allocation<Self::PointerTag, Self::AllocExtra>>, Self::PointerTag);

    fn init_frame_extra(
        ecx: &mut InterpCx<'mir, 'tcx, Self>, 
        frame: Frame<'mir, 'tcx, Self::PointerTag>
    ) -> InterpResult<'tcx, Frame<'mir, 'tcx, Self::PointerTag, Self::FrameExtra>>;

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

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

    fn ptr_to_int(
        _mem: &Memory<'mir, 'tcx, Self>, 
        _ptr: Pointer<Self::PointerTag>
    ) -> InterpResult<'tcx, u64>;

    fn load_mir(
        ecx: &InterpCx<'mir, 'tcx, Self>, 
        instance: InstanceDef<'tcx>
    ) -> InterpResult<'tcx, &'tcx Body<'tcx>> { ... }

    fn abort(
        _ecx: &mut InterpCx<'mir, 'tcx, Self>, 
        _msg: String
    ) -> InterpResult<'tcx, !> { ... }

    fn access_local(
        _ecx: &InterpCx<'mir, 'tcx, Self>, 
        frame: &Frame<'mir, 'tcx, Self::PointerTag, Self::FrameExtra>, 
        local: Local
    ) -> InterpResult<'tcx, Operand<Self::PointerTag>> { ... }

    fn access_local_mut<'a>(
        ecx: &'a mut InterpCx<'mir, 'tcx, Self>, 
        frame: usize, 
        local: Local
    ) -> InterpResult<'tcx, Result<&'a mut LocalValue<Self::PointerTag>, MemPlace<Self::PointerTag>>>
    where
        'tcx: 'mir,
    { ... }

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

    fn before_access_global(
        _memory_extra: &Self::MemoryExtra, 
        _alloc_id: AllocId, 
        _allocation: &Allocation, 
        _static_def_id: Option<DefId>, 
        _is_write: bool
    ) -> InterpResult<'tcx> { ... }

    fn thread_local_static_alloc_id(
        _ecx: &mut InterpCx<'mir, 'tcx, Self>, 
        def_id: DefId
    ) -> InterpResult<'tcx, AllocId> { ... }

    fn extern_static_alloc_id(
        mem: &Memory<'mir, 'tcx, Self>, 
        def_id: DefId
    ) -> InterpResult<'tcx, AllocId> { ... }

    fn before_deallocation(
        _memory_extra: &mut Self::MemoryExtra, 
        _id: AllocId
    ) -> InterpResult<'tcx> { ... }

    fn after_static_mem_initialized(
        _ecx: &mut InterpCx<'mir, 'tcx, Self>, 
        _ptr: Pointer<Self::PointerTag>, 
        _size: Size
    ) -> InterpResult<'tcx> { ... }

    fn retag(
        _ecx: &mut InterpCx<'mir, 'tcx, Self>, 
        _kind: RetagKind, 
        _place: &PlaceTy<'tcx, Self::PointerTag>
    ) -> InterpResult<'tcx> { ... }

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

    fn after_stack_pop(
        _ecx: &mut InterpCx<'mir, 'tcx, Self>, 
        _frame: Frame<'mir, 'tcx, Self::PointerTag, Self::FrameExtra>, 
        _unwinding: bool
    ) -> InterpResult<'tcx, StackPopJump> { ... }

    fn int_to_ptr(
        _mem: &Memory<'mir, 'tcx, Self>, 
        int: u64
    ) -> InterpResult<'tcx, Pointer<Self::PointerTag>> { ... }
}

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

Associated Types

type MemoryKind: Debug + Display + MayLeak + Eq + 'static[src]

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

type PointerTag: Debug + Copy + Eq + Hash + 'static[src]

Tag tracked alongside every pointer. This is used to implement “Stacked Borrows” https://www.ralfj.de/blog/2018/08/07/stacked-borrows.html. The default() is used for pointers to consts, statics, vtables and functions. The Debug formatting is used for displaying pointers; we cannot use Display as () does not implement that, but it should be “nice” output.

type ExtraFnVal: Debug + Copy[src]

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[src]

Extra data stored in every call frame.

type MemoryExtra[src]

Extra data stored in memory. A reference to this is available when AllocExtra gets initialized, so you can e.g., have an Rc here if there is global state you need access to in the AllocExtra hooks.

type AllocExtra: AllocationExtra<Self::PointerTag> + 'static[src]

Extra data stored in every allocation.

type MemoryMap: AllocMap<AllocId, (MemoryKind<Self::MemoryKind>, Allocation<Self::PointerTag, Self::AllocExtra>)> + Default + Clone[src]

Memory’s allocation map

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Associated Constants

const GLOBAL_KIND: Option<Self::MemoryKind>[src]

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 tag_allocation (see below) returns an owned allocation that is added to the memory so that the work is not done twice.

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Required methods

fn enforce_alignment(memory_extra: &Self::MemoryExtra) -> bool[src]

Whether memory accesses should be alignment-checked.

fn force_int_for_alignment_check(memory_extra: &Self::MemoryExtra) -> bool[src]

Whether, when checking alignment, we should force_int and thus support custom alignment logic based on whatever the integer address happens to be.

fn enforce_validity(ecx: &InterpCx<'mir, 'tcx, Self>) -> bool[src]

Whether to enforce the validity invariant

fn find_mir_or_eval_fn(
    ecx: &mut InterpCx<'mir, 'tcx, Self>,
    instance: Instance<'tcx>,
    abi: Abi,
    args: &[OpTy<'tcx, Self::PointerTag>],
    ret: Option<(&PlaceTy<'tcx, Self::PointerTag>, BasicBlock)>,
    unwind: Option<BasicBlock>
) -> InterpResult<'tcx, Option<&'mir Body<'tcx>>>[src]

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<'mir, 'tcx, Self>,
    fn_val: Self::ExtraFnVal,
    abi: Abi,
    args: &[OpTy<'tcx, Self::PointerTag>],
    ret: Option<(&PlaceTy<'tcx, Self::PointerTag>, BasicBlock)>,
    unwind: Option<BasicBlock>
) -> InterpResult<'tcx>[src]

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

fn call_intrinsic(
    ecx: &mut InterpCx<'mir, 'tcx, Self>,
    instance: Instance<'tcx>,
    args: &[OpTy<'tcx, Self::PointerTag>],
    ret: Option<(&PlaceTy<'tcx, Self::PointerTag>, BasicBlock)>,
    unwind: Option<BasicBlock>
) -> InterpResult<'tcx>[src]

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

fn assert_panic(
    ecx: &mut InterpCx<'mir, 'tcx, Self>,
    msg: &AssertMessage<'tcx>,
    unwind: Option<BasicBlock>
) -> InterpResult<'tcx>[src]

Called to evaluate Assert MIR terminators that trigger a panic.

fn binary_ptr_op(
    ecx: &InterpCx<'mir, 'tcx, Self>,
    bin_op: BinOp,
    left: &ImmTy<'tcx, Self::PointerTag>,
    right: &ImmTy<'tcx, Self::PointerTag>
) -> InterpResult<'tcx, (Scalar<Self::PointerTag>, bool, Ty<'tcx>)>[src]

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

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

fn box_alloc(
    ecx: &mut InterpCx<'mir, 'tcx, Self>,
    dest: &PlaceTy<'tcx, Self::PointerTag>
) -> InterpResult<'tcx>[src]

Heap allocations via the box keyword.

fn tag_global_base_pointer(
    memory_extra: &Self::MemoryExtra,
    id: AllocId
) -> Self::PointerTag[src]

Return the “base” tag for the given global allocation: the one that is used for direct accesses to this static/const/fn allocation. If id is not a global allocation, this will return an unusable tag (i.e., accesses will be UB)!

Called on the id returned by thread_local_static_alloc_id and extern_static_alloc_id, if needed.

fn init_allocation_extra<'b>(
    memory_extra: &Self::MemoryExtra,
    id: AllocId,
    alloc: Cow<'b, Allocation>,
    kind: Option<MemoryKind<Self::MemoryKind>>
) -> (Cow<'b, Allocation<Self::PointerTag, Self::AllocExtra>>, Self::PointerTag)[src]

Called to initialize the “extra” state of an allocation and make the pointers it contains (in relocations) tagged. 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.

kind is the kind of the allocation being tagged; it can be None when it’s a global and GLOBAL_KIND is None.

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 add tags or metadata), 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.)

Also return the “base” tag to use for this allocation: the one that is used for direct accesses to this allocation. If kind == STATIC_KIND, this tag must be consistent with tag_global_base_pointer.

fn init_frame_extra(
    ecx: &mut InterpCx<'mir, 'tcx, Self>,
    frame: Frame<'mir, 'tcx, Self::PointerTag>
) -> InterpResult<'tcx, Frame<'mir, 'tcx, Self::PointerTag, Self::FrameExtra>>[src]

Called immediately before a new stack frame gets pushed.

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

Borrow the current thread’s stack.

fn stack_mut<'a>(
    ecx: &'a mut InterpCx<'mir, 'tcx, Self>
) -> &'a mut Vec<Frame<'mir, 'tcx, Self::PointerTag, Self::FrameExtra>>[src]

Mutably borrow the current thread’s stack.

fn ptr_to_int(
    _mem: &Memory<'mir, 'tcx, Self>,
    _ptr: Pointer<Self::PointerTag>
) -> InterpResult<'tcx, u64>[src]

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Provided methods

fn load_mir(
    ecx: &InterpCx<'mir, 'tcx, Self>,
    instance: InstanceDef<'tcx>
) -> InterpResult<'tcx, &'tcx Body<'tcx>>[src]

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 abort(
    _ecx: &mut InterpCx<'mir, 'tcx, Self>,
    _msg: String
) -> InterpResult<'tcx, !>[src]

Called to evaluate Abort MIR terminator.

fn access_local(
    _ecx: &InterpCx<'mir, 'tcx, Self>,
    frame: &Frame<'mir, 'tcx, Self::PointerTag, Self::FrameExtra>,
    local: Local
) -> InterpResult<'tcx, Operand<Self::PointerTag>>[src]

Called to read the specified local from the frame. Since reading a ZST is not actually accessing memory or locals, this is never invoked for ZST reads.

fn access_local_mut<'a>(
    ecx: &'a mut InterpCx<'mir, 'tcx, Self>,
    frame: usize,
    local: Local
) -> InterpResult<'tcx, Result<&'a mut LocalValue<Self::PointerTag>, MemPlace<Self::PointerTag>>> where
    'tcx: 'mir, [src]

Called to write the specified local from the frame. Since writing a ZST is not actually accessing memory or locals, this is never invoked for ZST reads.

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

Called before a basic block terminator is executed. You can use this to detect endlessly running programs.

fn before_access_global(
    _memory_extra: &Self::MemoryExtra,
    _alloc_id: AllocId,
    _allocation: &Allocation,
    _static_def_id: Option<DefId>,
    _is_write: bool
) -> InterpResult<'tcx>[src]

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

fn thread_local_static_alloc_id(
    _ecx: &mut InterpCx<'mir, 'tcx, Self>,
    def_id: DefId
) -> InterpResult<'tcx, AllocId>[src]

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

fn extern_static_alloc_id(
    mem: &Memory<'mir, 'tcx, Self>,
    def_id: DefId
) -> InterpResult<'tcx, AllocId>[src]

Return the AllocId backing the given extern static.

fn before_deallocation(
    _memory_extra: &mut Self::MemoryExtra,
    _id: AllocId
) -> InterpResult<'tcx>[src]

Called to notify the machine before a deallocation occurs.

fn after_static_mem_initialized(
    _ecx: &mut InterpCx<'mir, 'tcx, Self>,
    _ptr: Pointer<Self::PointerTag>,
    _size: Size
) -> InterpResult<'tcx>[src]

Called after initializing static memory using the interpreter.

fn retag(
    _ecx: &mut InterpCx<'mir, 'tcx, Self>,
    _kind: RetagKind,
    _place: &PlaceTy<'tcx, Self::PointerTag>
) -> InterpResult<'tcx>[src]

Executes a retagging operation

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

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

fn after_stack_pop(
    _ecx: &mut InterpCx<'mir, 'tcx, Self>,
    _frame: Frame<'mir, 'tcx, Self::PointerTag, Self::FrameExtra>,
    _unwinding: bool
) -> InterpResult<'tcx, StackPopJump>[src]

Called immediately after a stack frame got popped, but before jumping back to the caller.

fn int_to_ptr(
    _mem: &Memory<'mir, 'tcx, Self>,
    int: u64
) -> InterpResult<'tcx, Pointer<Self::PointerTag>>[src]

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Implementors

impl<'mir, 'tcx> Machine<'mir, 'tcx> for CompileTimeInterpreter<'mir, 'tcx>[src]

type PointerTag = ()

type ExtraFnVal = !

type MemoryMap = FxHashMap<AllocId, (MemoryKind<Self::MemoryKind>, Allocation)>

type AllocExtra = ()

type FrameExtra = ()

type MemoryKind = MemoryKind

type MemoryExtra = MemoryExtra

impl<'mir, 'tcx> Machine<'mir, 'tcx> for ConstPropMachine<'mir, 'tcx>[src]

type PointerTag = ()

type ExtraFnVal = !

type MemoryMap = FxHashMap<AllocId, (MemoryKind<Self::MemoryKind>, Allocation)>

type AllocExtra = ()

type FrameExtra = ()

type MemoryKind = !

type MemoryExtra = ()

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