X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=src%2Foperator.rs;h=cf92aed9ccb2c5edcf98e451e042f56b142198e3;hb=20e31dbdad67080eb83aa3b5330dfe2f116f9900;hp=2a90d3e12f4c0f41c51c0f4a837051aed579333e;hpb=4ddc37df7a27d442e72db07f02108a71f6ab3f6e;p=rust.git

diff --git a/src/operator.rs b/src/operator.rs
index 2a90d3e12f4..cf92aed9ccb 100644
--- a/src/operator.rs
+++ b/src/operator.rs
@@ -1,7 +1,6 @@
-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::*;
 
@@ -9,44 +8,36 @@ pub trait EvalContextExt<'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>)>;
 
-    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)
@@ -68,27 +59,21 @@ fn binary_ptr_op(
             }
 
             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?
@@ -96,38 +81,4 @@ fn ptr_eq(
         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)
-    }
 }