-use std::convert::TryFrom;
+use log::trace;
-use rustc::ty::{Ty, layout::{Size, LayoutOf}};
-use rustc::mir;
+use rustc_middle::{mir, ty::Ty};
use crate::*;
fn binary_ptr_op(
&self,
bin_op: mir::BinOp,
- left: ImmTy<'tcx, Tag>,
- right: ImmTy<'tcx, Tag>,
+ left: &ImmTy<'tcx, Tag>,
+ right: &ImmTy<'tcx, Tag>,
) -> InterpResult<'tcx, (Scalar<Tag>, bool, Ty<'tcx>)>;
- fn ptr_eq(
- &self,
- left: Scalar<Tag>,
- right: Scalar<Tag>,
- ) -> InterpResult<'tcx, bool>;
-
- fn pointer_offset_inbounds(
- &self,
- ptr: Scalar<Tag>,
- pointee_ty: Ty<'tcx>,
- offset: i64,
- ) -> InterpResult<'tcx, Scalar<Tag>>;
+ fn ptr_eq(&self, left: Scalar<Tag>, right: Scalar<Tag>) -> InterpResult<'tcx, bool>;
}
impl<'mir, 'tcx> EvalContextExt<'tcx> for super::MiriEvalContext<'mir, 'tcx> {
fn binary_ptr_op(
&self,
bin_op: mir::BinOp,
- left: ImmTy<'tcx, Tag>,
- right: ImmTy<'tcx, Tag>,
+ left: &ImmTy<'tcx, Tag>,
+ right: &ImmTy<'tcx, Tag>,
) -> InterpResult<'tcx, (Scalar<Tag>, bool, Ty<'tcx>)> {
- use rustc::mir::BinOp::*;
+ use rustc_middle::mir::BinOp::*;
trace!("ptr_op: {:?} {:?} {:?}", *left, bin_op, *right);
Ok(match bin_op {
Eq | Ne => {
// This supports fat pointers.
- let eq = match (*left, *right) {
- (Immediate::Scalar(left), Immediate::Scalar(right)) =>
- self.ptr_eq(left.not_undef()?, right.not_undef()?)?,
- (Immediate::ScalarPair(left1, left2), Immediate::ScalarPair(right1, right2)) =>
- self.ptr_eq(left1.not_undef()?, right1.not_undef()?)? &&
- self.ptr_eq(left2.not_undef()?, right2.not_undef()?)?,
+ #[rustfmt::skip]
+ let eq = match (**left, **right) {
+ (Immediate::Scalar(left), Immediate::Scalar(right)) => {
+ self.ptr_eq(left.check_init()?, right.check_init()?)?
+ }
+ (Immediate::ScalarPair(left1, left2), Immediate::ScalarPair(right1, right2)) => {
+ self.ptr_eq(left1.check_init()?, right1.check_init()?)?
+ && self.ptr_eq(left2.check_init()?, right2.check_init()?)?
+ }
_ => bug!("Type system should not allow comparing Scalar with ScalarPair"),
};
(Scalar::from_bool(if bin_op == Eq { eq } else { !eq }), false, self.tcx.types.bool)
}
Offset => {
- let pointee_ty = left.layout.ty
- .builtin_deref(true)
- .expect("Offset called on non-ptr type")
- .ty;
- let ptr = self.pointer_offset_inbounds(
+ let pointee_ty =
+ left.layout.ty.builtin_deref(true).expect("Offset called on non-ptr type").ty;
+ let ptr = self.ptr_offset_inbounds(
left.to_scalar()?,
pointee_ty,
- right.to_scalar()?.to_isize(self)?,
+ right.to_scalar()?.to_machine_isize(self)?,
)?;
(ptr, false, left.layout.ty)
}
- _ => bug!("Invalid operator on pointers: {:?}", bin_op)
+ _ => bug!("Invalid operator on pointers: {:?}", bin_op),
})
}
- fn ptr_eq(
- &self,
- left: Scalar<Tag>,
- right: Scalar<Tag>,
- ) -> InterpResult<'tcx, bool> {
+ fn ptr_eq(&self, left: Scalar<Tag>, right: Scalar<Tag>) -> InterpResult<'tcx, bool> {
let size = self.pointer_size();
// Just compare the integers.
// TODO: Do we really want to *always* do that, even when comparing two live in-bounds pointers?
let right = self.force_bits(right, size)?;
Ok(left == right)
}
-
- /// Raises an error if the offset moves the pointer outside of its allocation.
- /// For integers, we consider each of them their own tiny allocation of size 0,
- /// so offset-by-0 is okay for them -- except for NULL, which we rule out entirely.
- fn pointer_offset_inbounds(
- &self,
- ptr: Scalar<Tag>,
- pointee_ty: Ty<'tcx>,
- offset: i64,
- ) -> InterpResult<'tcx, Scalar<Tag>> {
- let pointee_size = i64::try_from(self.layout_of(pointee_ty)?.size.bytes()).unwrap();
- let offset = offset
- .checked_mul(pointee_size)
- .ok_or_else(|| err_panic!(Overflow(mir::BinOp::Mul)))?;
- // We do this first, to rule out overflows.
- let offset_ptr = ptr.ptr_signed_offset(offset, self)?;
- // What we need to check is that starting at `min(ptr, offset_ptr)`,
- // we could do an access of size `abs(offset)`. Alignment does not matter.
- let (min_ptr, abs_offset) = if offset >= 0 {
- (ptr, u64::try_from(offset).unwrap())
- } else {
- // Negative offset.
- // If the negation overflows, the result will be negative so the try_from will fail.
- (offset_ptr, u64::try_from(-offset).unwrap())
- };
- self.memory.check_ptr_access_align(
- min_ptr,
- Size::from_bytes(abs_offset),
- None,
- CheckInAllocMsg::InboundsTest,
- )?;
- // That's it!
- Ok(offset_ptr)
- }
}