From fcbaf990f222cdfbfcd89f639793290bba1fed23 Mon Sep 17 00:00:00 2001
From: Oliver Schneider <git-spam-no-reply9815368754983@oli-obk.de>
Date: Mon, 26 Sep 2016 11:37:23 +0200
Subject: [PATCH] check `Pointer::to_int` for non-integer pointers

---
 src/interpreter/cast.rs | 11 ++++++++++-
 src/memory.rs           |  8 ++++++--
 src/primval.rs          |  4 ++--
 3 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/src/interpreter/cast.rs b/src/interpreter/cast.rs
index 4f31cc210339..a924d59782ad 100644
--- a/src/interpreter/cast.rs
+++ b/src/interpreter/cast.rs
@@ -8,7 +8,7 @@ use primval::PrimVal;
 use memory::Pointer;
 
 use rustc::ty::Ty;
-use syntax::ast;
+use syntax::ast::{self, IntTy, UintTy};
 
 impl<'a, 'tcx> EvalContext<'a, 'tcx> {
     pub(super) fn cast_primval(&self, val: PrimVal, ty: Ty<'tcx>) -> EvalResult<'tcx, PrimVal> {
@@ -38,6 +38,15 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> {
             ty::TyRef(..) |
             ty::TyRawPtr(_) => Ok(Ptr(ptr)),
             ty::TyFnPtr(_) => Ok(FnPtr(ptr)),
+            // FIXME: can truncation happen here?
+            ty::TyInt(IntTy::I8) => Ok(I8(ptr.to_int()? as i8)),
+            ty::TyInt(IntTy::I16) => Ok(I16(ptr.to_int()? as i16)),
+            ty::TyInt(IntTy::I32) => Ok(I32(ptr.to_int()? as i32)),
+            ty::TyInt(IntTy::I64) => Ok(I64(ptr.to_int()? as i64)),
+            ty::TyUint(UintTy::U8) => Ok(U8(ptr.to_int()? as u8)),
+            ty::TyUint(UintTy::U16) => Ok(U16(ptr.to_int()? as u16)),
+            ty::TyUint(UintTy::U32) => Ok(U32(ptr.to_int()? as u32)),
+            ty::TyUint(UintTy::U64) => Ok(U64(ptr.to_int()? as u64)),
             _ => Err(EvalError::Unimplemented(format!("ptr to {:?} cast", ty))),
         }
     }
diff --git a/src/memory.rs b/src/memory.rs
index d1c0c7408433..bdd9cd2fa0f4 100644
--- a/src/memory.rs
+++ b/src/memory.rs
@@ -55,8 +55,12 @@ impl Pointer {
     pub fn points_to_zst(&self) -> bool {
         self.alloc_id == ZST_ALLOC_ID
     }
-    pub fn to_int(&self) -> usize {
-        self.offset
+    pub fn to_int<'tcx>(&self) -> EvalResult<'tcx, usize> {
+        if self.points_to_zst() {
+            Ok(self.offset)
+        } else {
+            Err(EvalError::ReadPointerAsBytes)
+        }
     }
     pub fn from_int(i: usize) -> Self {
         Pointer {
diff --git a/src/primval.rs b/src/primval.rs
index 82e261625249..7d88e2ee7b14 100644
--- a/src/primval.rs
+++ b/src/primval.rs
@@ -46,7 +46,7 @@ impl PrimVal {
             U16(u) => u as u64,
             U32(u) => u as u64,
             U64(u) => u,
-            Ptr(ptr) => ptr.to_int() as u64,
+            Ptr(ptr) => ptr.to_int().expect("non abstract ptr") as u64,
             _ => bug!("{}", error_msg),
         }
     }
@@ -58,7 +58,7 @@ impl PrimVal {
             I16(i) => i as i64,
             I32(i) => i as i64,
             I64(i) => i,
-            Ptr(ptr) => ptr.to_int() as i64,
+            Ptr(ptr) => ptr.to_int().expect("non abstract ptr") as i64,
             _ => bug!("{}", error_msg),
         }
     }