]> git.lizzy.rs Git - rust.git/commitdiff
Auto merge of #52712 - oli-obk:const_eval_cleanups, r=RalfJung
authorbors <bors@rust-lang.org>
Fri, 3 Aug 2018 14:28:12 +0000 (14:28 +0000)
committerbors <bors@rust-lang.org>
Fri, 3 Aug 2018 14:28:12 +0000 (14:28 +0000)
Reintroduce `Undef` and properly check constant value sizes

r? @RalfJung

cc @eddyb

basically all kinds of silent failures that never occurred are assertions now

28 files changed:
src/librustc/ich/impls_ty.rs
src/librustc/mir/interpret/mod.rs
src/librustc/mir/interpret/value.rs
src/librustc/mir/mod.rs
src/librustc/ty/sty.rs
src/librustc_codegen_llvm/mir/constant.rs
src/librustc_codegen_llvm/mir/operand.rs
src/librustc_mir/hair/cx/mod.rs
src/librustc_mir/hair/pattern/mod.rs
src/librustc_mir/interpret/cast.rs
src/librustc_mir/interpret/const_eval.rs
src/librustc_mir/interpret/eval_context.rs
src/librustc_mir/interpret/memory.rs
src/librustc_mir/interpret/mod.rs
src/librustc_mir/interpret/operator.rs
src/librustc_mir/interpret/place.rs
src/librustc_mir/interpret/step.rs
src/librustc_mir/interpret/terminator/drop.rs
src/librustc_mir/interpret/terminator/mod.rs
src/librustc_mir/interpret/traits.rs
src/librustc_mir/monomorphize/collector.rs
src/librustc_mir/transform/const_prop.rs
src/test/compile-fail/const-err4.rs
src/test/ui/const-eval/simple_with_undef.rs [new file with mode: 0644]
src/test/ui/const-eval/union-const-eval-field.rs
src/test/ui/const-eval/union-const-eval-field.stderr
src/test/ui/const-eval/union-ice.rs
src/test/ui/const-eval/union-ice.stderr

index cb685f83aba1eb670852fcb33970e6fb4a5a98f8..f13e26fee3ee460aa80a5c1201ea50dd86094af3 100644 (file)
@@ -392,6 +392,11 @@ fn hash_stable<W: StableHasherResult>(&self,
     }
 }
 
+impl_stable_hash_for!(enum mir::interpret::ScalarMaybeUndef {
+    Scalar(v),
+    Undef
+});
+
 impl_stable_hash_for!(enum mir::interpret::Value {
     Scalar(v),
     ScalarPair(a, b),
@@ -466,9 +471,9 @@ fn hash_stable<W: StableHasherResult>(&self,
 
         mem::discriminant(self).hash_stable(hcx, hasher);
         match *self {
-            Bits { bits, defined } => {
+            Bits { bits, size } => {
                 bits.hash_stable(hcx, hasher);
-                defined.hash_stable(hcx, hasher);
+                size.hash_stable(hcx, hasher);
             },
             Ptr(ptr) => ptr.hash_stable(hcx, hasher),
         }
index 4164fe3fd933b80a8c65eb7c300127a94a0d4539..a0980b06230c8a05b4bdf5428e7962b1934ee81a 100644 (file)
@@ -13,7 +13,7 @@ macro_rules! err {
     FrameInfo, ConstEvalResult,
 };
 
-pub use self::value::{Scalar, Value, ConstValue};
+pub use self::value::{Scalar, Value, ConstValue, ScalarMaybeUndef};
 
 use std::fmt;
 use mir;
index ffd138c9c4815542c897c6880c8fffcdea194923..f569f4def143f8dd6af8c2b71b4cbc27ae4a6219 100644 (file)
@@ -15,22 +15,24 @@ pub enum ConstValue<'tcx> {
     /// to allow HIR creation to happen for everything before needing to be able to run constant
     /// evaluation
     Unevaluated(DefId, &'tcx Substs<'tcx>),
-    /// Used only for types with layout::abi::Scalar ABI and ZSTs which use Scalar::undef()
+    /// Used only for types with layout::abi::Scalar ABI and ZSTs
     Scalar(Scalar),
     /// Used only for types with layout::abi::ScalarPair
-    ScalarPair(Scalar, Scalar),
+    ///
+    /// The second field may be undef in case of `Option<usize>::None`
+    ScalarPair(Scalar, ScalarMaybeUndef),
     /// Used only for the remaining cases. An allocation + offset into the allocation
     ByRef(&'tcx Allocation, Size),
 }
 
 impl<'tcx> ConstValue<'tcx> {
     #[inline]
-    pub fn from_byval_value(val: Value) -> Self {
-        match val {
+    pub fn from_byval_value(val: Value) -> EvalResult<'static, Self> {
+        Ok(match val {
             Value::ByRef(..) => bug!(),
-            Value::ScalarPair(a, b) => ConstValue::ScalarPair(a, b),
-            Value::Scalar(val) => ConstValue::Scalar(val),
-        }
+            Value::ScalarPair(a, b) => ConstValue::ScalarPair(a.unwrap_or_err()?, b),
+            Value::Scalar(val) => ConstValue::Scalar(val.unwrap_or_err()?),
+        })
     }
 
     #[inline]
@@ -38,18 +40,13 @@ pub fn to_byval_value(&self) -> Option<Value> {
         match *self {
             ConstValue::Unevaluated(..) |
             ConstValue::ByRef(..) => None,
-            ConstValue::ScalarPair(a, b) => Some(Value::ScalarPair(a, b)),
-            ConstValue::Scalar(val) => Some(Value::Scalar(val)),
+            ConstValue::ScalarPair(a, b) => Some(Value::ScalarPair(a.into(), b)),
+            ConstValue::Scalar(val) => Some(Value::Scalar(val.into())),
         }
     }
 
     #[inline]
-    pub fn from_scalar(val: Scalar) -> Self {
-        ConstValue::Scalar(val)
-    }
-
-    #[inline]
-    pub fn to_scalar(&self) -> Option<Scalar> {
+    pub fn try_to_scalar(&self) -> Option<Scalar> {
         match *self {
             ConstValue::Unevaluated(..) |
             ConstValue::ByRef(..) |
@@ -60,12 +57,12 @@ pub fn to_scalar(&self) -> Option<Scalar> {
 
     #[inline]
     pub fn to_bits(&self, size: Size) -> Option<u128> {
-        self.to_scalar()?.to_bits(size).ok()
+        self.try_to_scalar()?.to_bits(size).ok()
     }
 
     #[inline]
     pub fn to_ptr(&self) -> Option<Pointer> {
-        self.to_scalar()?.to_ptr().ok()
+        self.try_to_scalar()?.to_ptr().ok()
     }
 }
 
@@ -81,8 +78,8 @@ pub fn to_ptr(&self) -> Option<Pointer> {
 #[derive(Clone, Copy, Debug, Eq, PartialEq, Ord, PartialOrd, RustcEncodable, RustcDecodable, Hash)]
 pub enum Value {
     ByRef(Scalar, Align),
-    Scalar(Scalar),
-    ScalarPair(Scalar, Scalar),
+    Scalar(ScalarMaybeUndef),
+    ScalarPair(ScalarMaybeUndef, ScalarMaybeUndef),
 }
 
 impl<'tcx> ty::TypeFoldable<'tcx> for Value {
@@ -98,23 +95,27 @@ impl<'tcx> Scalar {
     pub fn ptr_null<C: HasDataLayout>(cx: C) -> Self {
         Scalar::Bits {
             bits: 0,
-            defined: cx.data_layout().pointer_size.bits() as u8,
+            size: cx.data_layout().pointer_size.bytes() as u8,
         }
     }
 
+    pub fn to_value_with_len<C: HasDataLayout>(self, len: u64, cx: C) -> Value {
+        ScalarMaybeUndef::Scalar(self).to_value_with_len(len, cx)
+    }
+
+    pub fn to_value_with_vtable(self, vtable: Pointer) -> Value {
+        ScalarMaybeUndef::Scalar(self).to_value_with_vtable(vtable)
+    }
+
     pub fn ptr_signed_offset<C: HasDataLayout>(self, i: i64, cx: C) -> EvalResult<'tcx, Self> {
         let layout = cx.data_layout();
         match self {
-            Scalar::Bits { bits, defined } => {
-                let pointer_size = layout.pointer_size.bits() as u8;
-                if defined < pointer_size {
-                    err!(ReadUndefBytes)
-                } else {
-                    Ok(Scalar::Bits {
-                        bits: layout.signed_offset(bits as u64, i)? as u128,
-                        defined: pointer_size,
-                    })
-            }
+            Scalar::Bits { bits, size } => {
+                assert_eq!(size as u64, layout.pointer_size.bytes());
+                Ok(Scalar::Bits {
+                    bits: layout.signed_offset(bits as u64, i)? as u128,
+                    size,
+                })
             }
             Scalar::Ptr(ptr) => ptr.signed_offset(i, layout).map(Scalar::Ptr),
         }
@@ -123,65 +124,43 @@ pub fn ptr_signed_offset<C: HasDataLayout>(self, i: i64, cx: C) -> EvalResult<'t
     pub fn ptr_offset<C: HasDataLayout>(self, i: Size, cx: C) -> EvalResult<'tcx, Self> {
         let layout = cx.data_layout();
         match self {
-            Scalar::Bits { bits, defined } => {
-                let pointer_size = layout.pointer_size.bits() as u8;
-                if defined < pointer_size {
-                    err!(ReadUndefBytes)
-                } else {
-                    Ok(Scalar::Bits {
-                        bits: layout.offset(bits as u64, i.bytes())? as u128,
-                        defined: pointer_size,
-                    })
-            }
+            Scalar::Bits { bits, size } => {
+                assert_eq!(size as u64, layout.pointer_size.bytes());
+                Ok(Scalar::Bits {
+                    bits: layout.offset(bits as u64, i.bytes())? as u128,
+                    size,
+                })
             }
             Scalar::Ptr(ptr) => ptr.offset(i, layout).map(Scalar::Ptr),
         }
     }
 
-    pub fn ptr_wrapping_signed_offset<C: HasDataLayout>(self, i: i64, cx: C) -> EvalResult<'tcx, Self> {
+    pub fn ptr_wrapping_signed_offset<C: HasDataLayout>(self, i: i64, cx: C) -> Self {
         let layout = cx.data_layout();
         match self {
-            Scalar::Bits { bits, defined } => {
-                let pointer_size = layout.pointer_size.bits() as u8;
-                if defined < pointer_size {
-                    err!(ReadUndefBytes)
-                } else {
-                    Ok(Scalar::Bits {
-                        bits: layout.wrapping_signed_offset(bits as u64, i) as u128,
-                        defined: pointer_size,
-                    })
-            }
+            Scalar::Bits { bits, size } => {
+                assert_eq!(size as u64, layout.pointer_size.bytes());
+                Scalar::Bits {
+                    bits: layout.wrapping_signed_offset(bits as u64, i) as u128,
+                    size,
+                }
             }
-            Scalar::Ptr(ptr) => Ok(Scalar::Ptr(ptr.wrapping_signed_offset(i, layout))),
+            Scalar::Ptr(ptr) => Scalar::Ptr(ptr.wrapping_signed_offset(i, layout)),
         }
     }
 
-    pub fn is_null_ptr<C: HasDataLayout>(self, cx: C) -> EvalResult<'tcx, bool> {
+    pub fn is_null_ptr<C: HasDataLayout>(self, cx: C) -> bool {
         match self {
-            Scalar::Bits {
-                bits, defined,
-            } => if defined < cx.data_layout().pointer_size.bits() as u8 {
-                err!(ReadUndefBytes)
-            } else {
-                Ok(bits == 0)
+            Scalar::Bits { bits, size } =>  {
+                assert_eq!(size as u64, cx.data_layout().pointer_size.bytes());
+                bits == 0
             },
-            Scalar::Ptr(_) => Ok(false),
+            Scalar::Ptr(_) => false,
         }
     }
 
-    pub fn to_value_with_len<C: HasDataLayout>(self, len: u64, cx: C) -> Value {
-        Value::ScalarPair(self, Scalar::Bits {
-            bits: len as u128,
-            defined: cx.data_layout().pointer_size.bits() as u8,
-        })
-    }
-
-    pub fn to_value_with_vtable(self, vtable: Pointer) -> Value {
-        Value::ScalarPair(self, Scalar::Ptr(vtable))
-    }
-
     pub fn to_value(self) -> Value {
-        Value::Scalar(self)
+        Value::Scalar(ScalarMaybeUndef::Scalar(self))
     }
 }
 
@@ -199,8 +178,9 @@ fn from(ptr: Pointer) -> Self {
 pub enum Scalar {
     /// The raw bytes of a simple value.
     Bits {
-        /// The first `defined` number of bits are valid
-        defined: u8,
+        /// The first `size` bytes are the value.
+        /// Do not try to read less or more bytes that that
+        size: u8,
         bits: u128,
     },
 
@@ -210,25 +190,63 @@ pub enum Scalar {
     Ptr(Pointer),
 }
 
-impl<'tcx> Scalar {
-    pub fn undef() -> Self {
-        Scalar::Bits { bits: 0, defined: 0 }
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Ord, PartialOrd, RustcEncodable, RustcDecodable, Hash)]
+pub enum ScalarMaybeUndef {
+    Scalar(Scalar),
+    Undef,
+}
+
+impl From<Scalar> for ScalarMaybeUndef {
+    fn from(s: Scalar) -> Self {
+        ScalarMaybeUndef::Scalar(s)
+    }
+}
+
+impl ScalarMaybeUndef {
+    pub fn unwrap_or_err(self) -> EvalResult<'static, Scalar> {
+        match self {
+            ScalarMaybeUndef::Scalar(scalar) => Ok(scalar),
+            ScalarMaybeUndef::Undef => err!(ReadUndefBytes),
+        }
+    }
+
+    pub fn to_value_with_len<C: HasDataLayout>(self, len: u64, cx: C) -> Value {
+        Value::ScalarPair(self, Scalar::Bits {
+            bits: len as u128,
+            size: cx.data_layout().pointer_size.bytes() as u8,
+        }.into())
     }
 
+    pub fn to_value_with_vtable(self, vtable: Pointer) -> Value {
+        Value::ScalarPair(self, Scalar::Ptr(vtable).into())
+    }
+
+    pub fn ptr_offset<C: HasDataLayout>(self, i: Size, cx: C) -> EvalResult<'tcx, Self> {
+        match self {
+            ScalarMaybeUndef::Scalar(scalar) => {
+                scalar.ptr_offset(i, cx).map(ScalarMaybeUndef::Scalar)
+            },
+            ScalarMaybeUndef::Undef => Ok(ScalarMaybeUndef::Undef)
+        }
+    }
+}
+
+impl<'tcx> Scalar {
     pub fn from_bool(b: bool) -> Self {
-        // FIXME: can we make defined `1`?
-        Scalar::Bits { bits: b as u128, defined: 8 }
+        Scalar::Bits { bits: b as u128, size: 1 }
     }
 
     pub fn from_char(c: char) -> Self {
-        Scalar::Bits { bits: c as u128, defined: 32 }
+        Scalar::Bits { bits: c as u128, size: 4 }
     }
 
-    pub fn to_bits(self, size: Size) -> EvalResult<'tcx, u128> {
+    pub fn to_bits(self, target_size: Size) -> EvalResult<'tcx, u128> {
         match self {
-            Scalar::Bits { .. } if size.bits() == 0 => bug!("to_bits cannot be used with zsts"),
-            Scalar::Bits { bits, defined } if size.bits() <= defined as u64 => Ok(bits),
-            Scalar::Bits { .. } => err!(ReadUndefBytes),
+            Scalar::Bits { bits, size } => {
+                assert_eq!(target_size.bytes(), size as u64);
+                assert_ne!(size, 0, "to_bits cannot be used with zsts");
+                Ok(bits)
+            }
             Scalar::Ptr(_) => err!(ReadPointerAsBytes),
         }
     }
@@ -256,8 +274,8 @@ pub fn is_ptr(self) -> bool {
 
     pub fn to_bool(self) -> EvalResult<'tcx, bool> {
         match self {
-            Scalar::Bits { bits: 0, defined: 8 } => Ok(false),
-            Scalar::Bits { bits: 1, defined: 8 } => Ok(true),
+            Scalar::Bits { bits: 0, size: 1 } => Ok(false),
+            Scalar::Bits { bits: 1, size: 1 } => Ok(true),
             _ => err!(InvalidBool),
         }
     }
index 4bfb4c96497ff6327d2d8993f45083923e2a7213..dae5709ba114a3721f86bdb41ee2fcb9ae1594e7 100644 (file)
@@ -17,7 +17,7 @@
 use hir::def_id::DefId;
 use hir::{self, HirId, InlineAsm};
 use middle::region;
-use mir::interpret::{EvalErrorKind, Scalar, Value};
+use mir::interpret::{EvalErrorKind, Scalar, Value, ScalarMaybeUndef};
 use mir::visit::MirVisitable;
 use rustc_apfloat::ieee::{Double, Single};
 use rustc_apfloat::Float;
@@ -1465,10 +1465,10 @@ pub fn fmt_successor_labels(&self) -> Vec<Cow<'static, str>> {
                     .map(|&u| {
                         let mut s = String::new();
                         print_miri_value(
-                            Value::Scalar(Scalar::Bits {
+                            Scalar::Bits {
                                 bits: u,
-                                defined: size.bits() as u8,
-                            }),
+                                size: size.bytes() as u8,
+                            }.to_value(),
                             switch_ty,
                             &mut s,
                         ).unwrap();
@@ -2225,45 +2225,58 @@ pub fn fmt_const_val<W: Write>(fmt: &mut W, const_val: &ty::Const) -> fmt::Resul
 
 pub fn print_miri_value<W: Write>(value: Value, ty: Ty, f: &mut W) -> fmt::Result {
     use ty::TypeVariants::*;
-    match (value, &ty.sty) {
-        (Value::Scalar(Scalar::Bits { bits: 0, .. }), &TyBool) => write!(f, "false"),
-        (Value::Scalar(Scalar::Bits { bits: 1, .. }), &TyBool) => write!(f, "true"),
-        (Value::Scalar(Scalar::Bits { bits, .. }), &TyFloat(ast::FloatTy::F32)) => {
-            write!(f, "{}f32", Single::from_bits(bits))
-        }
-        (Value::Scalar(Scalar::Bits { bits, .. }), &TyFloat(ast::FloatTy::F64)) => {
-            write!(f, "{}f64", Double::from_bits(bits))
-        }
-        (Value::Scalar(Scalar::Bits { bits, .. }), &TyUint(ui)) => write!(f, "{:?}{}", bits, ui),
-        (Value::Scalar(Scalar::Bits { bits, .. }), &TyInt(i)) => {
-            let bit_width = ty::tls::with(|tcx| {
-                let ty = tcx.lift_to_global(&ty).unwrap();
-                tcx.layout_of(ty::ParamEnv::empty().and(ty))
-                    .unwrap()
-                    .size
-                    .bits()
-            });
-            let shift = 128 - bit_width;
-            write!(f, "{:?}{}", ((bits as i128) << shift) >> shift, i)
-        }
-        (Value::Scalar(Scalar::Bits { bits, .. }), &TyChar) => {
-            write!(f, "{:?}", ::std::char::from_u32(bits as u32).unwrap())
+    // print some primitives
+    if let Value::Scalar(ScalarMaybeUndef::Scalar(Scalar::Bits { bits, .. })) = value {
+        match ty.sty {
+            TyBool if bits == 0 => return write!(f, "false"),
+            TyBool if bits == 1 => return write!(f, "true"),
+            TyFloat(ast::FloatTy::F32) => return write!(f, "{}f32", Single::from_bits(bits)),
+            TyFloat(ast::FloatTy::F64) => return write!(f, "{}f64", Double::from_bits(bits)),
+            TyUint(ui) => return write!(f, "{:?}{}", bits, ui),
+            TyInt(i) => {
+                let bit_width = ty::tls::with(|tcx| {
+                    let ty = tcx.lift_to_global(&ty).unwrap();
+                    tcx.layout_of(ty::ParamEnv::empty().and(ty))
+                        .unwrap()
+                        .size
+                        .bits()
+                });
+                let shift = 128 - bit_width;
+                return write!(f, "{:?}{}", ((bits as i128) << shift) >> shift, i);
+            }
+            TyChar => return write!(f, "{:?}", ::std::char::from_u32(bits as u32).unwrap()),
+            _ => {},
         }
-        (_, &TyFnDef(did, _)) => write!(f, "{}", item_path_str(did)),
-        (
-            Value::ScalarPair(Scalar::Ptr(ptr), Scalar::Bits { bits: len, .. }),
-            &TyRef(_, &ty::TyS { sty: TyStr, .. }, _),
-        ) => ty::tls::with(|tcx| match tcx.alloc_map.lock().get(ptr.alloc_id) {
-            Some(interpret::AllocType::Memory(alloc)) => {
-                assert_eq!(len as usize as u128, len);
-                let slice = &alloc.bytes[(ptr.offset.bytes() as usize)..][..(len as usize)];
-                let s = ::std::str::from_utf8(slice).expect("non utf8 str from miri");
-                write!(f, "{:?}", s)
+    }
+    // print function definitons
+    if let TyFnDef(did, _) = ty.sty {
+        return write!(f, "{}", item_path_str(did));
+    }
+    // print string literals
+    if let Value::ScalarPair(ptr, len) = value {
+        if let ScalarMaybeUndef::Scalar(Scalar::Ptr(ptr)) = ptr {
+            if let ScalarMaybeUndef::Scalar(Scalar::Bits { bits: len, .. }) = len {
+                if let TyRef(_, &ty::TyS { sty: TyStr, .. }, _) = ty.sty {
+                    return ty::tls::with(|tcx| {
+                        let alloc = tcx.alloc_map.lock().get(ptr.alloc_id);
+                        if let Some(interpret::AllocType::Memory(alloc)) = alloc {
+                            assert_eq!(len as usize as u128, len);
+                            let slice = &alloc
+                                .bytes
+                                    [(ptr.offset.bytes() as usize)..]
+                                    [..(len as usize)];
+                            let s = ::std::str::from_utf8(slice).expect("non utf8 str from miri");
+                            write!(f, "{:?}", s)
+                        } else {
+                             write!(f, "pointer to erroneous constant {:?}, {:?}", ptr, len)
+                        }
+                    });
+                }
             }
-            _ => write!(f, "pointer to erroneous constant {:?}, {:?}", ptr, len),
-        }),
-        _ => write!(f, "{:?}:{}", value, ty),
+        }
     }
+    // just raw dump everything else
+    write!(f, "{:?}:{}", value, ty)
 }
 
 fn item_path_str(def_id: DefId) -> String {
index dd38188824338f7a1a5bb648c701f7dd5865696a..96b4edce86b30f5603b33af3f259b4bd62ce213e 100644 (file)
@@ -1887,22 +1887,13 @@ pub fn from_const_value(
         })
     }
 
-    #[inline]
-    pub fn from_byval_value(
-        tcx: TyCtxt<'_, '_, 'tcx>,
-        val: Value,
-        ty: Ty<'tcx>,
-    ) -> &'tcx Self {
-        Self::from_const_value(tcx, ConstValue::from_byval_value(val), ty)
-    }
-
     #[inline]
     pub fn from_scalar(
         tcx: TyCtxt<'_, '_, 'tcx>,
         val: Scalar,
         ty: Ty<'tcx>,
     ) -> &'tcx Self {
-        Self::from_const_value(tcx, ConstValue::from_scalar(val), ty)
+        Self::from_const_value(tcx, ConstValue::Scalar(val), ty)
     }
 
     #[inline]
@@ -1918,12 +1909,12 @@ pub fn from_bits(
         let shift = 128 - size.bits();
         let truncated = (bits << shift) >> shift;
         assert_eq!(truncated, bits, "from_bits called with untruncated value");
-        Self::from_scalar(tcx, Scalar::Bits { bits, defined: size.bits() as u8 }, ty.value)
+        Self::from_scalar(tcx, Scalar::Bits { bits, size: size.bytes() as u8 }, ty.value)
     }
 
     #[inline]
     pub fn zero_sized(tcx: TyCtxt<'_, '_, 'tcx>, ty: Ty<'tcx>) -> &'tcx Self {
-        Self::from_scalar(tcx, Scalar::undef(), ty)
+        Self::from_scalar(tcx, Scalar::Bits { bits: 0, size: 0 }, ty)
     }
 
     #[inline]
@@ -1960,11 +1951,6 @@ pub fn to_byval_value(&self) -> Option<Value> {
         self.val.to_byval_value()
     }
 
-    #[inline]
-    pub fn to_scalar(&self) -> Option<Scalar> {
-        self.val.to_scalar()
-    }
-
     #[inline]
     pub fn assert_bits(
         &self,
index 341ed9df64b5927c1df9250ffb7b5386f4483cd6..267db4467c21a23e376e7c89c9099404c000628d 100644 (file)
@@ -39,10 +39,12 @@ pub fn scalar_to_llvm(
 ) -> &'ll Value {
     let bitsize = if layout.is_bool() { 1 } else { layout.value.size(cx).bits() };
     match cv {
-        Scalar::Bits { defined, .. } if (defined as u64) < bitsize || defined == 0 => {
-            C_undef(Type::ix(cx, bitsize))
+        Scalar::Bits { size: 0, .. } => {
+            assert_eq!(0, layout.value.size(cx).bytes());
+            C_undef(Type::ix(cx, 0))
         },
-        Scalar::Bits { bits, .. } => {
+        Scalar::Bits { bits, size } => {
+            assert_eq!(size as u64, layout.value.size(cx).bytes());
             let llval = C_uint_big(Type::ix(cx, bitsize), bits);
             if layout.value == layout::Pointer {
                 unsafe { llvm::LLVMConstIntToPtr(llval, llty) }
@@ -192,7 +194,7 @@ pub fn simd_shuffle_indices(
                         mir::Field::new(field as usize),
                         c,
                     )?;
-                    if let Some(prim) = field.to_scalar() {
+                    if let Some(prim) = field.val.try_to_scalar() {
                         let layout = bx.cx.layout_of(field_ty);
                         let scalar = match layout.abi {
                             layout::Abi::Scalar(ref x) => x,
index 1296f5e4b144efd703fce8891ae3c580dbfe7d3e..f8166ee6491472afcb6275a28ca2882193b377f6 100644 (file)
@@ -10,7 +10,7 @@
 
 use rustc::mir::interpret::ConstEvalErr;
 use rustc::mir;
-use rustc::mir::interpret::ConstValue;
+use rustc::mir::interpret::{ConstValue, ScalarMaybeUndef};
 use rustc::ty;
 use rustc::ty::layout::{self, Align, LayoutOf, TyLayout};
 use rustc_data_structures::indexed_vec::Idx;
@@ -110,12 +110,16 @@ pub fn from_const(bx: &Builder<'a, 'll, 'tcx>,
                     a_scalar,
                     layout.scalar_pair_element_llvm_type(bx.cx, 0, true),
                 );
-                let b_llval = scalar_to_llvm(
-                    bx.cx,
-                    b,
-                    b_scalar,
-                    layout.scalar_pair_element_llvm_type(bx.cx, 1, true),
-                );
+                let b_layout = layout.scalar_pair_element_llvm_type(bx.cx, 1, true);
+                let b_llval = match b {
+                    ScalarMaybeUndef::Scalar(b) => scalar_to_llvm(
+                        bx.cx,
+                        b,
+                        b_scalar,
+                        b_layout,
+                    ),
+                    ScalarMaybeUndef::Undef => C_undef(b_layout),
+                };
                 OperandValue::Pair(a_llval, b_llval)
             },
             ConstValue::ByRef(alloc, offset) => {
index 4a7225c3a76d1a93e718dd31c5551003480ab8fd..70148fc91760443bb6d31b18de8988fa5eb6ac21 100644 (file)
@@ -151,14 +151,14 @@ pub fn const_eval_literal(
 
         let trunc = |n| {
             let param_ty = self.param_env.and(self.tcx.lift_to_global(&ty).unwrap());
-            let bit_width = self.tcx.layout_of(param_ty).unwrap().size.bits();
-            trace!("trunc {} with size {} and shift {}", n, bit_width, 128 - bit_width);
-            let shift = 128 - bit_width;
+            let width = self.tcx.layout_of(param_ty).unwrap().size;
+            trace!("trunc {} with size {} and shift {}", n, width.bits(), 128 - width.bits());
+            let shift = 128 - width.bits();
             let result = (n << shift) >> shift;
             trace!("trunc result: {}", result);
             ConstValue::Scalar(Scalar::Bits {
                 bits: result,
-                defined: bit_width as u8,
+                size: width.bytes() as u8,
             })
         };
 
@@ -168,7 +168,7 @@ pub fn const_eval_literal(
                 let s = s.as_str();
                 let id = self.tcx.allocate_bytes(s.as_bytes());
                 let value = Scalar::Ptr(id.into()).to_value_with_len(s.len() as u64, self.tcx);
-                ConstValue::from_byval_value(value)
+                ConstValue::from_byval_value(value).unwrap()
             },
             LitKind::ByteStr(ref data) => {
                 let id = self.tcx.allocate_bytes(data);
@@ -176,7 +176,7 @@ pub fn const_eval_literal(
             },
             LitKind::Byte(n) => ConstValue::Scalar(Scalar::Bits {
                 bits: n as u128,
-                defined: 8,
+                size: 1,
             }),
             LitKind::Int(n, _) if neg => {
                 let n = n as i128;
@@ -194,14 +194,8 @@ pub fn const_eval_literal(
                 };
                 parse_float(n, fty)
             }
-            LitKind::Bool(b) => ConstValue::Scalar(Scalar::Bits {
-                bits: b as u128,
-                defined: 8,
-            }),
-            LitKind::Char(c) => ConstValue::Scalar(Scalar::Bits {
-                bits: c as u128,
-                defined: 32,
-            }),
+            LitKind::Bool(b) => ConstValue::Scalar(Scalar::from_bool(b)),
+            LitKind::Char(c) => ConstValue::Scalar(Scalar::from_char(c)),
         };
         ty::Const::from_const_value(self.tcx, lit, ty)
     }
index 53511c1c127dd3a608813cf38a92c0f4cd58ed92..d614131c526837623dbcae21965fb572b157206b 100644 (file)
@@ -19,7 +19,7 @@
 use interpret::{const_val_field, const_variant_index, self};
 
 use rustc::mir::{fmt_const_val, Field, BorrowKind, Mutability};
-use rustc::mir::interpret::{Scalar, GlobalId, ConstValue, Value};
+use rustc::mir::interpret::{Scalar, GlobalId, ConstValue};
 use rustc::ty::{self, TyCtxt, AdtDef, Ty, Region};
 use rustc::ty::subst::{Substs, Kind};
 use rustc::hir::{self, PatKind, RangeEnd};
@@ -1080,8 +1080,9 @@ pub fn compare_const_vals<'a, 'tcx>(
                 l.partial_cmp(&r)
             },
             ty::TyInt(_) => {
-                let a = interpret::sign_extend(tcx, a, ty.value).expect("layout error for TyInt");
-                let b = interpret::sign_extend(tcx, b, ty.value).expect("layout error for TyInt");
+                let layout = tcx.layout_of(ty).ok()?;
+                let a = interpret::sign_extend(a, layout);
+                let b = interpret::sign_extend(b, layout);
                 Some((a as i128).cmp(&(b as i128)))
             },
             _ => Some(a.cmp(&b)),
@@ -1090,17 +1091,24 @@ pub fn compare_const_vals<'a, 'tcx>(
 
     if let ty::TyRef(_, rty, _) = ty.value.sty {
         if let ty::TyStr = rty.sty {
-            match (a.to_byval_value(), b.to_byval_value()) {
+            match (a.val, b.val) {
                 (
-                    Some(Value::ScalarPair(
+                    ConstValue::ScalarPair(
                         Scalar::Ptr(ptr_a),
                         len_a,
-                    )),
-                    Some(Value::ScalarPair(
+                    ),
+                    ConstValue::ScalarPair(
                         Scalar::Ptr(ptr_b),
                         len_b,
-                    ))
+                    ),
                 ) if ptr_a.offset.bytes() == 0 && ptr_b.offset.bytes() == 0 => {
+                    let len_a = len_a.unwrap_or_err().ok();
+                    let len_b = len_b.unwrap_or_err().ok();
+                    if len_a.is_none() || len_b.is_none() {
+                        tcx.sess.struct_err("str slice len is undef").delay_as_bug();
+                    }
+                    let len_a = len_a?;
+                    let len_b = len_b?;
                     if let Ok(len_a) = len_a.to_bits(tcx.data_layout.pointer_size) {
                         if let Ok(len_b) = len_b.to_bits(tcx.data_layout.pointer_size) {
                             if len_a == len_b {
@@ -1142,7 +1150,7 @@ fn lit_to_const<'a, 'tcx>(lit: &'tcx ast::LitKind,
             let s = s.as_str();
             let id = tcx.allocate_bytes(s.as_bytes());
             let value = Scalar::Ptr(id.into()).to_value_with_len(s.len() as u64, tcx);
-            ConstValue::from_byval_value(value)
+            ConstValue::from_byval_value(value).unwrap()
         },
         LitKind::ByteStr(ref data) => {
             let id = tcx.allocate_bytes(data);
@@ -1150,7 +1158,7 @@ fn lit_to_const<'a, 'tcx>(lit: &'tcx ast::LitKind,
         },
         LitKind::Byte(n) => ConstValue::Scalar(Scalar::Bits {
             bits: n as u128,
-            defined: 8,
+            size: 1,
         }),
         LitKind::Int(n, _) => {
             enum Int {
@@ -1188,10 +1196,10 @@ enum Int {
                 Int::Signed(IntTy::I128)| Int::Unsigned(UintTy::U128) => n,
                 _ => bug!(),
             };
-            let defined = tcx.layout_of(ty::ParamEnv::empty().and(ty)).unwrap().size.bits() as u8;
+            let size = tcx.layout_of(ty::ParamEnv::empty().and(ty)).unwrap().size.bytes() as u8;
             ConstValue::Scalar(Scalar::Bits {
                 bits: n,
-                defined,
+                size,
             })
         },
         LitKind::Float(n, fty) => {
@@ -1204,14 +1212,8 @@ enum Int {
             };
             parse_float(n, fty, neg).map_err(|_| LitToConstError::UnparseableFloat)?
         }
-        LitKind::Bool(b) => ConstValue::Scalar(Scalar::Bits {
-            bits: b as u128,
-            defined: 8,
-        }),
-        LitKind::Char(c) => ConstValue::Scalar(Scalar::Bits {
-            bits: c as u128,
-            defined: 32,
-        }),
+        LitKind::Bool(b) => ConstValue::Scalar(Scalar::from_bool(b)),
+        LitKind::Char(c) => ConstValue::Scalar(Scalar::from_char(c)),
     };
     Ok(ty::Const::from_const_value(tcx, lit, ty))
 }
@@ -1224,7 +1226,7 @@ pub fn parse_float<'tcx>(
     let num = num.as_str();
     use rustc_apfloat::ieee::{Single, Double};
     use rustc_apfloat::Float;
-    let (bits, defined) = match fty {
+    let (bits, size) = match fty {
         ast::FloatTy::F32 => {
             num.parse::<f32>().map_err(|_| ())?;
             let mut f = num.parse::<Single>().unwrap_or_else(|e| {
@@ -1233,7 +1235,7 @@ pub fn parse_float<'tcx>(
             if neg {
                 f = -f;
             }
-            (f.to_bits(), 32)
+            (f.to_bits(), 4)
         }
         ast::FloatTy::F64 => {
             num.parse::<f64>().map_err(|_| ())?;
@@ -1243,9 +1245,9 @@ pub fn parse_float<'tcx>(
             if neg {
                 f = -f;
             }
-            (f.to_bits(), 64)
+            (f.to_bits(), 8)
         }
     };
 
-    Ok(ConstValue::Scalar(Scalar::Bits { bits, defined }))
+    Ok(ConstValue::Scalar(Scalar::Bits { bits, size }))
 }
index 7bcf4ef6588d53d9335a767b077016d5b798b817..4e705254331a2f08a2d1eec5c724912ae5e58b71 100644 (file)
@@ -1,5 +1,5 @@
 use rustc::ty::{self, Ty};
-use rustc::ty::layout::{self, LayoutOf};
+use rustc::ty::layout::{self, LayoutOf, TyLayout};
 use syntax::ast::{FloatTy, IntTy, UintTy};
 
 use rustc_apfloat::ieee::{Single, Double};
@@ -18,11 +18,11 @@ impl<'a, 'mir, 'tcx, M: Machine<'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M> {
         dest_ty: Ty<'tcx>,
         dest: Place,
     ) -> EvalResult<'tcx> {
+        let src_layout = self.layout_of(src.ty)?;
+        let dst_layout = self.layout_of(dest_ty)?;
         use rustc::mir::CastKind::*;
         match kind {
             Unsize => {
-                let src_layout = self.layout_of(src.ty)?;
-                let dst_layout = self.layout_of(dest_ty)?;
                 self.unsize_into(src.value, src_layout, dest, dst_layout)?;
             }
 
@@ -57,16 +57,11 @@ impl<'a, 'mir, 'tcx, M: Machine<'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M> {
                                 let discr_val = def
                                     .discriminant_for_variant(*self.tcx, index)
                                     .val;
-                                let defined = self
-                                    .layout_of(dest_ty)
-                                    .unwrap()
-                                    .size
-                                    .bits() as u8;
                                 return self.write_scalar(
                                     dest,
                                     Scalar::Bits {
                                         bits: discr_val,
-                                        defined,
+                                        size: dst_layout.size.bytes() as u8,
                                     },
                                     dest_ty);
                             }
@@ -76,9 +71,9 @@ impl<'a, 'mir, 'tcx, M: Machine<'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M> {
                     }
 
                     let src_val = self.value_to_scalar(src)?;
-                    let dest_val = self.cast_scalar(src_val, src.ty, dest_ty)?;
+                    let dest_val = self.cast_scalar(src_val, src_layout, dst_layout)?;
                     let valty = ValTy {
-                        value: Value::Scalar(dest_val),
+                        value: Value::Scalar(dest_val.into()),
                         ty: dest_ty,
                     };
                     self.write_value(valty, dest)?;
@@ -100,7 +95,7 @@ impl<'a, 'mir, 'tcx, M: Machine<'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M> {
                         ).ok_or_else(|| EvalErrorKind::TooGeneric.into());
                         let fn_ptr = self.memory.create_fn_alloc(instance?);
                         let valty = ValTy {
-                            value: Value::Scalar(fn_ptr.into()),
+                            value: Value::Scalar(Scalar::Ptr(fn_ptr.into()).into()),
                             ty: dest_ty,
                         };
                         self.write_value(valty, dest)?;
@@ -136,7 +131,7 @@ impl<'a, 'mir, 'tcx, M: Machine<'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M> {
                         );
                         let fn_ptr = self.memory.create_fn_alloc(instance);
                         let valty = ValTy {
-                            value: Value::Scalar(fn_ptr.into()),
+                            value: Value::Scalar(Scalar::Ptr(fn_ptr.into()).into()),
                             ty: dest_ty,
                         };
                         self.write_value(valty, dest)?;
@@ -151,20 +146,19 @@ impl<'a, 'mir, 'tcx, M: Machine<'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M> {
     pub(super) fn cast_scalar(
         &self,
         val: Scalar,
-        src_ty: Ty<'tcx>,
-        dest_ty: Ty<'tcx>,
+        src_layout: TyLayout<'tcx>,
+        dest_layout: TyLayout<'tcx>,
     ) -> EvalResult<'tcx, Scalar> {
         use rustc::ty::TypeVariants::*;
-        trace!("Casting {:?}: {:?} to {:?}", val, src_ty, dest_ty);
+        trace!("Casting {:?}: {:?} to {:?}", val, src_layout.ty, dest_layout.ty);
 
         match val {
-            Scalar::Bits { defined: 0, .. } => Ok(val),
-            Scalar::Ptr(ptr) => self.cast_from_ptr(ptr, dest_ty),
-            Scalar::Bits { bits, .. } => {
-                // TODO(oli-obk): check defined bits here
-                match src_ty.sty {
-                    TyFloat(fty) => self.cast_from_float(bits, fty, dest_ty),
-                    _ => self.cast_from_int(bits, src_ty, dest_ty),
+            Scalar::Ptr(ptr) => self.cast_from_ptr(ptr, dest_layout.ty),
+            Scalar::Bits { bits, size } => {
+                assert_eq!(size as u64, src_layout.size.bytes());
+                match src_layout.ty.sty {
+                    TyFloat(fty) => self.cast_from_float(bits, fty, dest_layout.ty),
+                    _ => self.cast_from_int(bits, src_layout, dest_layout),
                 }
             }
         }
@@ -173,56 +167,58 @@ pub(super) fn cast_scalar(
     fn cast_from_int(
         &self,
         v: u128,
-        src_ty: Ty<'tcx>,
-        dest_ty: Ty<'tcx>,
+        src_layout: TyLayout<'tcx>,
+        dest_layout: TyLayout<'tcx>,
     ) -> EvalResult<'tcx, Scalar> {
-        let signed = self.layout_of(src_ty)?.abi.is_signed();
+        let signed = src_layout.abi.is_signed();
         let v = if signed {
-            self.sign_extend(v, src_ty)?
+            self.sign_extend(v, src_layout)
         } else {
             v
         };
-        trace!("cast_from_int: {}, {}, {}", v, src_ty, dest_ty);
+        trace!("cast_from_int: {}, {}, {}", v, src_layout.ty, dest_layout.ty);
         use rustc::ty::TypeVariants::*;
-        match dest_ty.sty {
+        match dest_layout.ty.sty {
             TyInt(_) | TyUint(_) => {
-                let v = self.truncate(v, dest_ty)?;
+                let v = self.truncate(v, dest_layout);
                 Ok(Scalar::Bits {
                     bits: v,
-                    defined: self.layout_of(dest_ty).unwrap().size.bits() as u8,
+                    size: dest_layout.size.bytes() as u8,
                 })
             }
 
             TyFloat(FloatTy::F32) if signed => Ok(Scalar::Bits {
                 bits: Single::from_i128(v as i128).value.to_bits(),
-                defined: 32,
+                size: 4,
             }),
             TyFloat(FloatTy::F64) if signed => Ok(Scalar::Bits {
                 bits: Double::from_i128(v as i128).value.to_bits(),
-                defined: 64,
+                size: 8,
             }),
             TyFloat(FloatTy::F32) => Ok(Scalar::Bits {
                 bits: Single::from_u128(v).value.to_bits(),
-                defined: 32,
+                size: 4,
             }),
             TyFloat(FloatTy::F64) => Ok(Scalar::Bits {
                 bits: Double::from_u128(v).value.to_bits(),
-                defined: 64,
+                size: 8,
             }),
 
-            TyChar if v as u8 as u128 == v => Ok(Scalar::Bits { bits: v, defined: 32 }),
-            TyChar => err!(InvalidChar(v)),
+            TyChar => {
+                assert_eq!(v as u8 as u128, v);
+                Ok(Scalar::Bits { bits: v, size: 4 })
+            },
 
             // No alignment check needed for raw pointers.  But we have to truncate to target ptr size.
             TyRawPtr(_) => {
                 Ok(Scalar::Bits {
                     bits: self.memory.truncate_to_ptr(v).0 as u128,
-                    defined: self.memory.pointer_size().bits() as u8,
+                    size: self.memory.pointer_size().bytes() as u8,
                 })
             },
 
             // Casts to bool are not permitted by rustc, no need to handle them here.
-            _ => err!(Unimplemented(format!("int to {:?} cast", dest_ty))),
+            _ => err!(Unimplemented(format!("int to {:?} cast", dest_layout.ty))),
         }
     }
 
@@ -236,11 +232,11 @@ fn cast_from_float(&self, bits: u128, fty: FloatTy, dest_ty: Ty<'tcx>) -> EvalRe
                 match fty {
                     FloatTy::F32 => Ok(Scalar::Bits {
                         bits: Single::from_bits(bits).to_u128(width).value,
-                        defined: width as u8,
+                        size: (width / 8) as u8,
                     }),
                     FloatTy::F64 => Ok(Scalar::Bits {
                         bits: Double::from_bits(bits).to_u128(width).value,
-                        defined: width as u8,
+                        size: (width / 8) as u8,
                     }),
                 }
             },
@@ -250,11 +246,11 @@ fn cast_from_float(&self, bits: u128, fty: FloatTy, dest_ty: Ty<'tcx>) -> EvalRe
                 match fty {
                     FloatTy::F32 => Ok(Scalar::Bits {
                         bits: Single::from_bits(bits).to_i128(width).value as u128,
-                        defined: width as u8,
+                        size: (width / 8) as u8,
                     }),
                     FloatTy::F64 => Ok(Scalar::Bits {
                         bits: Double::from_bits(bits).to_i128(width).value as u128,
-                        defined: width as u8,
+                        size: (width / 8) as u8,
                     }),
                 }
             },
@@ -262,24 +258,24 @@ fn cast_from_float(&self, bits: u128, fty: FloatTy, dest_ty: Ty<'tcx>) -> EvalRe
             TyFloat(FloatTy::F32) if fty == FloatTy::F64 => {
                 Ok(Scalar::Bits {
                     bits: Single::to_bits(Double::from_bits(bits).convert(&mut false).value),
-                    defined: 32,
+                    size: 4,
                 })
             },
             // f32 -> f64
             TyFloat(FloatTy::F64) if fty == FloatTy::F32 => {
                 Ok(Scalar::Bits {
                     bits: Double::to_bits(Single::from_bits(bits).convert(&mut false).value),
-                    defined: 64,
+                    size: 8,
                 })
             },
             // identity cast
             TyFloat(FloatTy:: F64) => Ok(Scalar::Bits {
                 bits,
-                defined: 64,
+                size: 8,
             }),
             TyFloat(FloatTy:: F32) => Ok(Scalar::Bits {
                 bits,
-                defined: 32,
+                size: 4,
             }),
             _ => err!(Unimplemented(format!("float to {:?} cast", dest_ty))),
         }
index 873fef75bb9ebf666d41be4b0729fc6b9da0e067..9d66a0b396b640fe7d3498aa75dc7b9caedb9bc2 100644 (file)
@@ -2,11 +2,12 @@
 use std::error::Error;
 
 use rustc::hir;
-use rustc::mir::interpret::{ConstEvalErr};
+use rustc::mir::interpret::{ConstEvalErr, ScalarMaybeUndef};
 use rustc::mir;
 use rustc::ty::{self, TyCtxt, Ty, Instance};
 use rustc::ty::layout::{self, LayoutOf, Primitive, TyLayout};
 use rustc::ty::subst::Subst;
+use rustc_data_structures::indexed_vec::IndexVec;
 
 use syntax::ast::Mutability;
 use syntax::codemap::Span;
@@ -28,13 +29,16 @@ pub fn mk_borrowck_eval_cx<'a, 'mir, 'tcx>(
     let param_env = tcx.param_env(instance.def_id());
     let mut ecx = EvalContext::new(tcx.at(span), param_env, CompileTimeEvaluator, ());
     // insert a stack frame so any queries have the correct substs
-    ecx.push_stack_frame(
+    ecx.stack.push(super::eval_context::Frame {
+        block: mir::START_BLOCK,
+        locals: IndexVec::new(),
         instance,
         span,
         mir,
-        Place::undef(),
-        StackPopCleanup::None,
-    )?;
+        return_place: Place::undef(),
+        return_to_block: StackPopCleanup::None,
+        stmt: 0,
+    });
     Ok(ecx)
 }
 
@@ -72,48 +76,30 @@ pub fn eval_promoted<'a, 'mir, 'tcx>(
 pub fn value_to_const_value<'tcx>(
     ecx: &EvalContext<'_, '_, 'tcx, CompileTimeEvaluator>,
     val: Value,
-    ty: Ty<'tcx>,
-) -> &'tcx ty::Const<'tcx> {
-    let layout = ecx.layout_of(ty).unwrap();
+    layout: TyLayout<'tcx>,
+) -> EvalResult<'tcx, &'tcx ty::Const<'tcx>> {
     match (val, &layout.abi) {
-        (Value::Scalar(Scalar::Bits { defined: 0, ..}), _) if layout.is_zst() => {},
+        (Value::Scalar(ScalarMaybeUndef::Scalar(Scalar::Bits { size: 0, ..})), _) if layout.is_zst() => {},
         (Value::ByRef(..), _) |
         (Value::Scalar(_), &layout::Abi::Scalar(_)) |
         (Value::ScalarPair(..), &layout::Abi::ScalarPair(..)) => {},
         _ => bug!("bad value/layout combo: {:#?}, {:#?}", val, layout),
     }
-    let val = (|| {
-        match val {
-            Value::Scalar(val) => Ok(ConstValue::Scalar(val)),
-            Value::ScalarPair(a, b) => Ok(ConstValue::ScalarPair(a, b)),
-            Value::ByRef(ptr, align) => {
-                let ptr = ptr.to_ptr().unwrap();
-                let alloc = ecx.memory.get(ptr.alloc_id)?;
-                assert!(alloc.align.abi() >= align.abi());
-                assert!(alloc.bytes.len() as u64 - ptr.offset.bytes() >= layout.size.bytes());
-                let mut alloc = alloc.clone();
-                alloc.align = align;
-                let alloc = ecx.tcx.intern_const_alloc(alloc);
-                Ok(ConstValue::ByRef(alloc, ptr.offset))
-            }
-        }
-    })();
-    match val {
-        Ok(val) => ty::Const::from_const_value(ecx.tcx.tcx, val, ty),
-        Err(err) => {
-            let (frames, span) = ecx.generate_stacktrace(None);
-            let err = ConstEvalErr {
-                span,
-                error: err,
-                stacktrace: frames,
-            };
-            err.report_as_error(
-                ecx.tcx,
-                "failed to convert Value to ConstValue, this is a bug",
-            );
-            span_bug!(span, "miri error occured when converting Value to ConstValue")
+    let val = match val {
+        Value::Scalar(val) => ConstValue::Scalar(val.unwrap_or_err()?),
+        Value::ScalarPair(a, b) => ConstValue::ScalarPair(a.unwrap_or_err()?, b),
+        Value::ByRef(ptr, align) => {
+            let ptr = ptr.to_ptr().unwrap();
+            let alloc = ecx.memory.get(ptr.alloc_id)?;
+            assert!(alloc.align.abi() >= align.abi());
+            assert!(alloc.bytes.len() as u64 - ptr.offset.bytes() >= layout.size.bytes());
+            let mut alloc = alloc.clone();
+            alloc.align = align;
+            let alloc = ecx.tcx.intern_const_alloc(alloc);
+            ConstValue::ByRef(alloc, ptr.offset)
         }
-    }
+    };
+    Ok(ty::Const::from_const_value(ecx.tcx.tcx, val, layout.ty))
 }
 
 fn eval_body_and_ecx<'a, 'mir, 'tcx>(
@@ -307,7 +293,7 @@ fn call_intrinsic<'a>(
                 let elem_align = ecx.layout_of(elem_ty)?.align.abi();
                 let align_val = Scalar::Bits {
                     bits: elem_align as u128,
-                    defined: dest_layout.size.bits() as u8,
+                    size: dest_layout.size.bytes() as u8,
                 };
                 ecx.write_scalar(dest, align_val, dest_layout.ty)?;
             }
@@ -317,7 +303,7 @@ fn call_intrinsic<'a>(
                 let size = ecx.layout_of(ty)?.size.bytes() as u128;
                 let size_val = Scalar::Bits {
                     bits: size,
-                    defined: dest_layout.size.bits() as u8,
+                    size: dest_layout.size.bytes() as u8,
                 };
                 ecx.write_scalar(dest, size_val, dest_layout.ty)?;
             }
@@ -327,7 +313,7 @@ fn call_intrinsic<'a>(
                 let type_id = ecx.tcx.type_id_hash(ty) as u128;
                 let id_val = Scalar::Bits {
                     bits: type_id,
-                    defined: dest_layout.size.bits() as u8,
+                    size: dest_layout.size.bytes() as u8,
                 };
                 ecx.write_scalar(dest, id_val, dest_layout.ty)?;
             }
@@ -437,7 +423,7 @@ pub fn const_val_field<'a, 'tcx>(
         let place = ecx.allocate_place_for_value(value, layout, variant)?;
         let (place, layout) = ecx.place_field(place, field, layout)?;
         let (ptr, align) = place.to_ptr_align();
-        let mut new_value = Value::ByRef(ptr, align);
+        let mut new_value = Value::ByRef(ptr.unwrap_or_err()?, align);
         new_value = ecx.try_read_by_ref(new_value, layout.ty)?;
         use rustc_data_structures::indexed_vec::Idx;
         match (value, new_value) {
@@ -451,7 +437,7 @@ pub fn const_val_field<'a, 'tcx>(
             ),
             _ => {},
         }
-        Ok(value_to_const_value(&ecx, new_value, layout.ty))
+        value_to_const_value(&ecx, new_value, layout)
     })();
     result.map_err(|err| {
         let (trace, span) = ecx.generate_stacktrace(None);
@@ -481,7 +467,7 @@ pub fn const_variant_index<'a, 'tcx>(
         },
         Value::ByRef(ptr, align) => (ptr, align),
     };
-    let place = Place::from_scalar_ptr(ptr, align);
+    let place = Place::from_scalar_ptr(ptr.into(), align);
     ecx.read_discriminant_as_variant_index(place, layout)
 }
 
@@ -552,7 +538,7 @@ pub fn const_eval_provider<'a, 'tcx>(
         if tcx.is_static(def_id).is_none() && cid.promoted.is_none() {
             val = ecx.try_read_by_ref(val, layout.ty)?;
         }
-        Ok(value_to_const_value(&ecx, val, layout.ty))
+        value_to_const_value(&ecx, val, layout)
     }).map_err(|err| {
         let (trace, span) = ecx.generate_stacktrace(None);
         let err = ConstEvalErr {
@@ -562,6 +548,9 @@ pub fn const_eval_provider<'a, 'tcx>(
         };
         if tcx.is_static(def_id).is_some() {
             err.report_as_error(ecx.tcx, "could not evaluate static initializer");
+            if tcx.sess.err_count() == 0 {
+                span_bug!(span, "static eval failure didn't emit an error: {:#?}", err);
+            }
         }
         err.into()
     })
@@ -572,11 +561,11 @@ fn numeric_intrinsic<'tcx>(
     bits: u128,
     kind: Primitive,
 ) -> EvalResult<'tcx, Scalar> {
-    let defined = match kind {
-        Primitive::Int(integer, _) => integer.size().bits() as u8,
+    let size = match kind {
+        Primitive::Int(integer, _) => integer.size(),
         _ => bug!("invalid `{}` argument: {:?}", name, bits),
     };
-    let extra = 128 - defined as u128;
+    let extra = 128 - size.bits() as u128;
     let bits_out = match name {
         "ctpop" => bits.count_ones() as u128,
         "ctlz" => bits.leading_zeros() as u128 - extra,
@@ -584,5 +573,5 @@ fn numeric_intrinsic<'tcx>(
         "bswap" => (bits << extra).swap_bytes(),
         _ => bug!("not a numeric intrinsic: {}", name),
     };
-    Ok(Scalar::Bits { bits: bits_out, defined })
+    Ok(Scalar::Bits { bits: bits_out, size: size.bytes() as u8 })
 }
index c6c1a1d1ebb22b8e43c43f278c75204d8ea10fd8..52305be5facef18c2b762c7ffe754320921c53d7 100644 (file)
@@ -15,6 +15,7 @@
 use rustc::mir::interpret::{
     GlobalId, Value, Scalar, FrameInfo, AllocType,
     EvalResult, EvalErrorKind, Pointer, ConstValue,
+    ScalarMaybeUndef,
 };
 
 use syntax::codemap::{self, Span};
@@ -105,9 +106,7 @@ pub struct Frame<'mir, 'tcx: 'mir> {
     /// `[return_ptr, arguments..., variables..., temporaries...]`. The locals are stored as `Option<Value>`s.
     /// `None` represents a local that is currently dead, while a live local
     /// can either directly contain `Scalar` or refer to some part of an `Allocation`.
-    ///
-    /// Before being initialized, arguments are `Value::Scalar(Scalar::undef())` and other locals are `None`.
-    pub locals: IndexVec<mir::Local, Option<Value>>,
+    pub locals: IndexVec<mir::Local, LocalValue>,
 
     ////////////////////////////////////////////////////////////////////////////////
     // Current position within the function
@@ -120,6 +119,21 @@ pub struct Frame<'mir, 'tcx: 'mir> {
     pub stmt: usize,
 }
 
+#[derive(Copy, Clone, PartialEq, Eq, Hash)]
+pub enum LocalValue {
+    Dead,
+    Live(Value),
+}
+
+impl LocalValue {
+    pub fn access(self) -> EvalResult<'static, Value> {
+        match self {
+            LocalValue::Dead => err!(DeadLocal),
+            LocalValue::Live(val) => Ok(val),
+        }
+    }
+}
+
 impl<'mir, 'tcx: 'mir> Eq for Frame<'mir, 'tcx> {}
 
 impl<'mir, 'tcx: 'mir> PartialEq for Frame<'mir, 'tcx> {
@@ -395,8 +409,8 @@ pub fn const_to_value(
                 let id = self.memory.allocate_value(alloc.clone(), MemoryKind::Stack)?;
                 Ok(Value::ByRef(Pointer::new(id, offset).into(), alloc.align))
             },
-            ConstValue::ScalarPair(a, b) => Ok(Value::ScalarPair(a, b)),
-            ConstValue::Scalar(val) => Ok(Value::Scalar(val)),
+            ConstValue::ScalarPair(a, b) => Ok(Value::ScalarPair(a.into(), b.into())),
+            ConstValue::Scalar(val) => Ok(Value::Scalar(val.into())),
         }
     }
 
@@ -452,7 +466,7 @@ pub fn monomorphize(&self, ty: Ty<'tcx>, substs: &'tcx Substs<'tcx>) -> Ty<'tcx>
     /// Note that the value does not matter if the type is sized. For unsized types,
     /// the value has to be a fat pointer, and we only care about the "extra" data in it.
     pub fn size_and_align_of_dst(
-        &mut self,
+        &self,
         ty: Ty<'tcx>,
         value: Value,
     ) -> EvalResult<'tcx, (Size, Align)> {
@@ -480,7 +494,7 @@ pub fn size_and_align_of_dst(
 
                     // Recurse to get the size of the dynamically sized field (must be
                     // the last field).
-                    let field_ty = layout.field(&self, layout.fields.count() - 1)?.ty;
+                    let field_ty = layout.field(self, layout.fields.count() - 1)?.ty;
                     let (unsized_size, unsized_align) =
                         self.size_and_align_of_dst(field_ty, value)?;
 
@@ -518,7 +532,7 @@ pub fn size_and_align_of_dst(
                 }
 
                 ty::TySlice(_) | ty::TyStr => {
-                    let (elem_size, align) = layout.field(&self, 0)?.size_and_align();
+                    let (elem_size, align) = layout.field(self, 0)?.size_and_align();
                     let (_, len) = self.into_slice(value)?;
                     Ok((elem_size * len, align))
                 }
@@ -538,8 +552,26 @@ pub fn push_stack_frame(
     ) -> EvalResult<'tcx> {
         ::log_settings::settings().indentation += 1;
 
-        let locals = if mir.local_decls.len() > 1 {
-            let mut locals = IndexVec::from_elem(Some(Value::Scalar(Scalar::undef())), &mir.local_decls);
+        // first push a stack frame so we have access to the local substs
+        self.stack.push(Frame {
+            mir,
+            block: mir::START_BLOCK,
+            return_to_block,
+            return_place,
+            // empty local array, we fill it in below, after we are inside the stack frame and
+            // all methods actually know about the frame
+            locals: IndexVec::new(),
+            span,
+            instance,
+            stmt: 0,
+        });
+
+        // don't allocate at all for trivial constants
+        if mir.local_decls.len() > 1 {
+            let mut locals = IndexVec::from_elem(LocalValue::Dead, &mir.local_decls);
+            for (local, decl) in locals.iter_mut().zip(mir.local_decls.iter()) {
+                *local = LocalValue::Live(self.init_value(decl.ty)?);
+            }
             match self.tcx.describe_def(instance.def_id()) {
                 // statics and constants don't have `Storage*` statements, no need to look for them
                 Some(Def::Static(..)) | Some(Def::Const(..)) | Some(Def::AssociatedConst(..)) => {},
@@ -550,29 +582,15 @@ pub fn push_stack_frame(
                             use rustc::mir::StatementKind::{StorageDead, StorageLive};
                             match stmt.kind {
                                 StorageLive(local) |
-                                StorageDead(local) => locals[local] = None,
+                                StorageDead(local) => locals[local] = LocalValue::Dead,
                                 _ => {}
                             }
                         }
                     }
                 },
             }
-            locals
-        } else {
-            // don't allocate at all for trivial constants
-            IndexVec::new()
-        };
-
-        self.stack.push(Frame {
-            mir,
-            block: mir::START_BLOCK,
-            return_to_block,
-            return_place,
-            locals,
-            span,
-            instance,
-            stmt: 0,
-        });
+            self.frame_mut().locals = locals;
+        }
 
         self.memory.cur_frame = self.cur_frame();
 
@@ -598,7 +616,7 @@ pub(super) fn pop_stack_frame(&mut self) -> EvalResult<'tcx> {
                 if let Place::Ptr { ptr, .. } = frame.return_place {
                     // FIXME: to_ptr()? might be too extreme here, static zsts might reach this under certain conditions
                     self.memory.mark_static_initialized(
-                        ptr.to_ptr()?.alloc_id,
+                        ptr.unwrap_or_err()?.to_ptr()?.alloc_id,
                         mutable,
                     )?
                 } else {
@@ -616,8 +634,9 @@ pub(super) fn pop_stack_frame(&mut self) -> EvalResult<'tcx> {
         Ok(())
     }
 
-    pub fn deallocate_local(&mut self, local: Option<Value>) -> EvalResult<'tcx> {
-        if let Some(Value::ByRef(ptr, _align)) = local {
+    pub fn deallocate_local(&mut self, local: LocalValue) -> EvalResult<'tcx> {
+        // FIXME: should we tell the user that there was a local which was never written to?
+        if let LocalValue::Live(Value::ByRef(ptr, _align)) = local {
             trace!("deallocating local");
             let ptr = ptr.to_ptr()?;
             self.memory.dump_alloc(ptr.alloc_id);
@@ -637,6 +656,7 @@ pub(super) fn eval_rvalue_into_place(
     ) -> EvalResult<'tcx> {
         let dest = self.eval_place(place)?;
         let dest_ty = self.place_ty(place);
+        let dest_layout = self.layout_of(dest_ty)?;
 
         use rustc::mir::Rvalue::*;
         match *rvalue {
@@ -675,7 +695,7 @@ pub(super) fn eval_rvalue_into_place(
 
             UnaryOp(un_op, ref operand) => {
                 let val = self.eval_operand_to_scalar(operand)?;
-                let val = self.unary_op(un_op, val, dest_ty)?;
+                let val = self.unary_op(un_op, val, dest_layout)?;
                 self.write_scalar(
                     dest,
                     val,
@@ -724,6 +744,7 @@ pub(super) fn eval_rvalue_into_place(
                 let (dest, dest_align) = self.force_allocation(dest)?.to_ptr_align();
 
                 if length > 0 {
+                    let dest = dest.unwrap_or_err()?;
                     //write the first value
                     self.write_value_to_ptr(value, dest, dest_align, elem_ty)?;
 
@@ -739,12 +760,12 @@ pub(super) fn eval_rvalue_into_place(
                 let src = self.eval_place(place)?;
                 let ty = self.place_ty(place);
                 let (_, len) = src.elem_ty_and_len(ty, self.tcx.tcx);
-                let defined = self.memory.pointer_size().bits() as u8;
+                let size = self.memory.pointer_size().bytes() as u8;
                 self.write_scalar(
                     dest,
                     Scalar::Bits {
                         bits: len as u128,
-                        defined,
+                        size,
                     },
                     dest_ty,
                 )?;
@@ -757,7 +778,7 @@ pub(super) fn eval_rvalue_into_place(
                 let (ptr, _align, extra) = self.force_allocation(src)?.to_ptr_align_extra();
 
                 let val = match extra {
-                    PlaceExtra::None => ptr.to_value(),
+                    PlaceExtra::None => Value::Scalar(ptr),
                     PlaceExtra::Length(len) => ptr.to_value_with_len(len, self.tcx.tcx),
                     PlaceExtra::Vtable(vtable) => ptr.to_value_with_vtable(vtable),
                     PlaceExtra::DowncastVariant(..) => {
@@ -781,12 +802,12 @@ pub(super) fn eval_rvalue_into_place(
                 let layout = self.layout_of(ty)?;
                 assert!(!layout.is_unsized(),
                         "SizeOf nullary MIR operator called for unsized type");
-                let defined = self.memory.pointer_size().bits() as u8;
+                let size = self.memory.pointer_size().bytes() as u8;
                 self.write_scalar(
                     dest,
                     Scalar::Bits {
                         bits: layout.size.bytes() as u128,
-                        defined,
+                        size,
                     },
                     dest_ty,
                 )?;
@@ -803,10 +824,10 @@ pub(super) fn eval_rvalue_into_place(
                 let layout = self.layout_of(ty)?;
                 let place = self.eval_place(place)?;
                 let discr_val = self.read_discriminant_value(place, layout)?;
-                let defined = self.layout_of(dest_ty).unwrap().size.bits() as u8;
+                let size = self.layout_of(dest_ty).unwrap().size.bytes() as u8;
                 self.write_scalar(dest, Scalar::Bits {
                     bits: discr_val,
-                    defined,
+                    size,
                 }, dest_ty)?;
             }
         }
@@ -957,10 +978,8 @@ pub fn read_discriminant_value(
                         assert!(variants_start == variants_end);
                         dataful_variant as u128
                     },
-                    Scalar::Bits { bits: raw_discr, defined } => {
-                        if defined < discr.size.bits() as u8 {
-                            return err!(ReadUndefBytes);
-                        }
+                    Scalar::Bits { bits: raw_discr, size } => {
+                        assert_eq!(size as u64, discr.size.bytes());
                         let discr = raw_discr.wrapping_sub(niche_start)
                             .wrapping_add(variants_start);
                         if variants_start <= discr && discr <= variants_end {
@@ -1002,14 +1021,14 @@ pub fn write_discriminant_value(
                 // raw discriminants for enums are isize or bigger during
                 // their computation, but the in-memory tag is the smallest possible
                 // representation
-                let size = tag.value.size(self.tcx.tcx).bits();
-                let shift = 128 - size;
+                let size = tag.value.size(self.tcx.tcx);
+                let shift = 128 - size.bits();
                 let discr_val = (discr_val << shift) >> shift;
 
                 let (discr_dest, tag) = self.place_field(dest, mir::Field::new(0), layout)?;
                 self.write_scalar(discr_dest, Scalar::Bits {
                     bits: discr_val,
-                    defined: size as u8,
+                    size: size.bytes() as u8,
                 }, tag.ty)?;
             }
             layout::Variants::NicheFilling {
@@ -1025,7 +1044,7 @@ pub fn write_discriminant_value(
                         .wrapping_add(niche_start);
                     self.write_scalar(niche_dest, Scalar::Bits {
                         bits: niche_value,
-                        defined: niche.size.bits() as u8,
+                        size: niche.size.bytes() as u8,
                     }, niche.ty)?;
                 }
             }
@@ -1063,7 +1082,7 @@ pub fn allocate_place_for_value(
             },
         };
         Ok(Place::Ptr {
-            ptr,
+            ptr: ptr.into(),
             align,
             extra: variant.map_or(PlaceExtra::None, PlaceExtra::DowncastVariant),
         })
@@ -1072,22 +1091,22 @@ pub fn allocate_place_for_value(
     pub fn force_allocation(&mut self, place: Place) -> EvalResult<'tcx, Place> {
         let new_place = match place {
             Place::Local { frame, local } => {
-                match self.stack[frame].locals[local] {
-                    None => return err!(DeadLocal),
-                    Some(Value::ByRef(ptr, align)) => {
+                match self.stack[frame].locals[local].access()? {
+                    Value::ByRef(ptr, align) => {
                         Place::Ptr {
-                            ptr,
+                            ptr: ptr.into(),
                             align,
                             extra: PlaceExtra::None,
                         }
                     }
-                    Some(val) => {
+                    val => {
                         let ty = self.stack[frame].mir.local_decls[local].ty;
                         let ty = self.monomorphize(ty, self.stack[frame].instance.substs);
                         let layout = self.layout_of(ty)?;
                         let ptr = self.alloc_ptr(layout)?;
                         self.stack[frame].locals[local] =
-                            Some(Value::ByRef(ptr.into(), layout.align)); // it stays live
+                            LocalValue::Live(Value::ByRef(ptr.into(), layout.align)); // it stays live
+
                         let place = Place::from_ptr(ptr, layout.align);
                         self.write_value(ValTy { value: val, ty }, place)?;
                         place
@@ -1120,7 +1139,7 @@ pub fn value_to_scalar(
         match self.follow_by_ref_value(value, ty)? {
             Value::ByRef { .. } => bug!("follow_by_ref_value can't result in `ByRef`"),
 
-            Value::Scalar(scalar) => Ok(scalar),
+            Value::Scalar(scalar) => scalar.unwrap_or_err(),
 
             Value::ScalarPair(..) => bug!("value_to_scalar can't work with fat pointers"),
         }
@@ -1137,11 +1156,11 @@ pub fn write_ptr(&mut self, dest: Place, val: Scalar, dest_ty: Ty<'tcx>) -> Eval
     pub fn write_scalar(
         &mut self,
         dest: Place,
-        val: Scalar,
+        val: impl Into<ScalarMaybeUndef>,
         dest_ty: Ty<'tcx>,
     ) -> EvalResult<'tcx> {
         let valty = ValTy {
-            value: Value::Scalar(val),
+            value: Value::Scalar(val.into()),
             ty: dest_ty,
         };
         self.write_value(valty, dest)
@@ -1160,15 +1179,15 @@ pub fn write_value(
         match dest {
             Place::Ptr { ptr, align, extra } => {
                 assert_eq!(extra, PlaceExtra::None);
-                self.write_value_to_ptr(src_val, ptr, align, dest_ty)
+                self.write_value_to_ptr(src_val, ptr.unwrap_or_err()?, align, dest_ty)
             }
 
             Place::Local { frame, local } => {
-                let dest = self.stack[frame].get_local(local)?;
+                let old_val = self.stack[frame].locals[local].access()?;
                 self.write_value_possibly_by_val(
                     src_val,
                     |this, val| this.stack[frame].set_local(local, val),
-                    dest,
+                    old_val,
                     dest_ty,
                 )
             }
@@ -1183,6 +1202,7 @@ fn write_value_possibly_by_val<F: FnOnce(&mut Self, Value) -> EvalResult<'tcx>>(
         old_dest_val: Value,
         dest_ty: Ty<'tcx>,
     ) -> EvalResult<'tcx> {
+        // FIXME: this should be a layout check, not underlying value
         if let Value::ByRef(dest_ptr, align) = old_dest_val {
             // If the value is already `ByRef` (that is, backed by an `Allocation`),
             // then we must write the new value into this allocation, because there may be
@@ -1239,12 +1259,9 @@ pub fn write_value_to_ptr(
                         layout::Primitive::Int(_, signed) => signed,
                         _ => false,
                     },
-                    _ => match scalar {
-                        Scalar::Bits { defined: 0, .. } => false,
-                        _ => bug!("write_value_to_ptr: invalid ByVal layout: {:#?}", layout),
-                    }
+                    _ => false,
                 };
-                self.memory.write_scalar(dest, dest_align, scalar, layout.size, signed)
+                self.memory.write_scalar(dest, dest_align, scalar, layout.size, layout.align, signed)
             }
             Value::ScalarPair(a_val, b_val) => {
                 trace!("write_value_to_ptr valpair: {:#?}", layout);
@@ -1253,12 +1270,13 @@ pub fn write_value_to_ptr(
                     _ => bug!("write_value_to_ptr: invalid ScalarPair layout: {:#?}", layout)
                 };
                 let (a_size, b_size) = (a.size(&self), b.size(&self));
+                let (a_align, b_align) = (a.align(&self), b.align(&self));
                 let a_ptr = dest;
-                let b_offset = a_size.abi_align(b.align(&self));
+                let b_offset = a_size.abi_align(b_align);
                 let b_ptr = dest.ptr_offset(b_offset, &self)?.into();
                 // TODO: What about signedess?
-                self.memory.write_scalar(a_ptr, dest_align, a_val, a_size, false)?;
-                self.memory.write_scalar(b_ptr, dest_align, b_val, b_size, false)
+                self.memory.write_scalar(a_ptr, dest_align, a_val, a_size, a_align, false)?;
+                self.memory.write_scalar(b_ptr, dest_align, b_val, b_size, b_align, false)
             }
         }
     }
@@ -1271,38 +1289,9 @@ pub fn read_value(&self, ptr: Scalar, align: Align, ty: Ty<'tcx>) -> EvalResult<
         }
     }
 
-    pub(crate) fn read_ptr(
-        &self,
-        ptr: Pointer,
-        ptr_align: Align,
-        pointee_ty: Ty<'tcx>,
-    ) -> EvalResult<'tcx, Value> {
-        let ptr_size = self.memory.pointer_size();
-        let p: Scalar = self.memory.read_ptr_sized(ptr, ptr_align)?.into();
-        if self.type_is_sized(pointee_ty) {
-            Ok(p.to_value())
-        } else {
-            trace!("reading fat pointer extra of type {}", pointee_ty);
-            let extra = ptr.offset(ptr_size, self)?;
-            match self.tcx.struct_tail(pointee_ty).sty {
-                ty::TyDynamic(..) => Ok(p.to_value_with_vtable(
-                    self.memory.read_ptr_sized(extra, ptr_align)?.to_ptr()?,
-                )),
-                ty::TySlice(..) | ty::TyStr => {
-                    let len = self
-                        .memory
-                        .read_ptr_sized(extra, ptr_align)?
-                        .to_bits(ptr_size)?;
-                    Ok(p.to_value_with_len(len as u64, self.tcx.tcx))
-                },
-                _ => bug!("unsized scalar ptr read from {:?}", pointee_ty),
-            }
-        }
-    }
-
     fn validate_scalar(
         &self,
-        value: Scalar,
+        value: ScalarMaybeUndef,
         size: Size,
         scalar: &layout::Scalar,
         path: &str,
@@ -1311,8 +1300,16 @@ fn validate_scalar(
         trace!("validate scalar: {:#?}, {:#?}, {:#?}, {}", value, size, scalar, ty);
         let (lo, hi) = scalar.valid_range.clone().into_inner();
 
-        let (bits, defined) = match value {
-            Scalar::Bits { bits, defined } => (bits, defined),
+        let value = match value {
+            ScalarMaybeUndef::Scalar(scalar) => scalar,
+            ScalarMaybeUndef::Undef => return validation_failure!("undefined bytes", path),
+        };
+
+        let bits = match value {
+            Scalar::Bits { bits, size: value_size } => {
+                assert_eq!(value_size as u64, size.bytes());
+                bits
+            },
             Scalar::Ptr(_) => {
                 let ptr_size = self.memory.pointer_size();
                 let ptr_max = u128::max_value() >> (128 - ptr_size.bits());
@@ -1346,7 +1343,7 @@ fn validate_scalar(
         // has no special checks for chars
         match ty.sty {
             ty::TyChar => {
-                assert_eq!(size.bytes(), 4);
+                debug_assert_eq!(size.bytes(), 4);
                 if ::std::char::from_u32(bits as u32).is_none() {
                     return err!(InvalidChar(bits));
                 }
@@ -1355,32 +1352,26 @@ fn validate_scalar(
         }
 
         use std::ops::RangeInclusive;
-        let in_range = |bound: RangeInclusive<u128>| {
-            defined as u64 >= size.bits() && bound.contains(&bits)
-        };
+        let in_range = |bound: RangeInclusive<u128>| bound.contains(&bits);
         if lo > hi {
             if in_range(0..=hi) || in_range(lo..=u128::max_value()) {
                 Ok(())
-            } else if defined as u64 >= size.bits() {
+            } else {
                 validation_failure!(
                     bits,
                     path,
                     format!("something in the range {:?} or {:?}", ..=hi, lo..)
                 )
-            } else {
-                validation_failure!("undefined bytes", path)
             }
         } else {
             if in_range(scalar.valid_range.clone()) {
                 Ok(())
-            } else if defined as u64 >= size.bits() {
+            } else {
                 validation_failure!(
                     bits,
                     path,
                     format!("something in the range {:?}", scalar.valid_range)
                 )
-            } else {
-                validation_failure!("undefined bytes", path)
             }
         }
     }
@@ -1410,10 +1401,10 @@ pub fn validate_ptr_target(
                     mir::Field::new(0),
                     layout,
                 )?;
-                let tag_value = self.value_to_scalar(ValTy {
-                    value: tag_value,
-                    ty: tag_layout.ty,
-                })?;
+                let tag_value = match self.follow_by_ref_value(tag_value, tag_layout.ty)? {
+                    Value::Scalar(val) => val,
+                    _ => bug!("tag must be scalar"),
+                };
                 let path = format!("{}.TAG", path);
                 self.validate_scalar(tag_value, size, tag, &path, tag_layout.ty)?;
                 let variant_index = self.read_discriminant_as_variant_index(
@@ -1440,7 +1431,7 @@ pub fn validate_ptr_target(
                         self.validate_scalar(value, size, scalar, &path, layout.ty)?;
                         if scalar.value == Primitive::Pointer {
                             // ignore integer pointers, we can't reason about the final hardware
-                            if let Scalar::Ptr(ptr) = value {
+                            if let Scalar::Ptr(ptr) = value.unwrap_or_err()? {
                                 let alloc_kind = self.tcx.alloc_map.lock().get(ptr.alloc_id);
                                 if let Some(AllocType::Static(did)) = alloc_kind {
                                     // statics from other crates are already checked
@@ -1534,7 +1525,7 @@ pub fn try_read_value(&self, ptr: Scalar, ptr_align: Align, ty: Ty<'tcx>) -> Eva
         self.memory.check_align(ptr, ptr_align)?;
 
         if layout.size.bytes() == 0 {
-            return Ok(Some(Value::Scalar(Scalar::undef())));
+            return Ok(Some(Value::Scalar(ScalarMaybeUndef::Scalar(Scalar::Bits { bits: 0, size: 0 }))));
         }
 
         let ptr = ptr.to_ptr()?;
@@ -1670,7 +1661,7 @@ fn unsize_into_ptr(
                     }
                     let (src_f_value, src_field) = match src {
                         Value::ByRef(ptr, align) => {
-                            let src_place = Place::from_scalar_ptr(ptr, align);
+                            let src_place = Place::from_scalar_ptr(ptr.into(), align);
                             let (src_f_place, src_field) =
                                 self.place_field(src_place, mir::Field::new(i), src_layout)?;
                             (self.read_place(src_f_place)?, src_field)
@@ -1717,7 +1708,7 @@ pub fn dump_local(&self, place: Place) {
                 }
                 write!(msg, ":").unwrap();
 
-                match self.stack[frame].get_local(local) {
+                match self.stack[frame].locals[local].access() {
                     Err(err) => {
                         if let EvalErrorKind::DeadLocal = err.kind {
                             write!(msg, " is dead").unwrap();
@@ -1736,16 +1727,16 @@ pub fn dump_local(&self, place: Place) {
                     }
                     Ok(Value::Scalar(val)) => {
                         write!(msg, " {:?}", val).unwrap();
-                        if let Scalar::Ptr(ptr) = val {
+                        if let ScalarMaybeUndef::Scalar(Scalar::Ptr(ptr)) = val {
                             allocs.push(ptr.alloc_id);
                         }
                     }
                     Ok(Value::ScalarPair(val1, val2)) => {
                         write!(msg, " ({:?}, {:?})", val1, val2).unwrap();
-                        if let Scalar::Ptr(ptr) = val1 {
+                        if let ScalarMaybeUndef::Scalar(Scalar::Ptr(ptr)) = val1 {
                             allocs.push(ptr.alloc_id);
                         }
-                        if let Scalar::Ptr(ptr) = val2 {
+                        if let ScalarMaybeUndef::Scalar(Scalar::Ptr(ptr)) = val2 {
                             allocs.push(ptr.alloc_id);
                         }
                     }
@@ -1756,7 +1747,7 @@ pub fn dump_local(&self, place: Place) {
             }
             Place::Ptr { ptr, align, .. } => {
                 match ptr {
-                    Scalar::Ptr(ptr) => {
+                    ScalarMaybeUndef::Scalar(Scalar::Ptr(ptr)) => {
                         trace!("by align({}) ref:", align.abi());
                         self.memory.dump_alloc(ptr.alloc_id);
                     }
@@ -1766,21 +1757,6 @@ pub fn dump_local(&self, place: Place) {
         }
     }
 
-    /// Convenience function to ensure correct usage of locals
-    pub fn modify_local<F>(&mut self, frame: usize, local: mir::Local, f: F) -> EvalResult<'tcx>
-    where
-        F: FnOnce(&mut Self, Value) -> EvalResult<'tcx, Value>,
-    {
-        let val = self.stack[frame].get_local(local)?;
-        let new_val = f(self, val)?;
-        self.stack[frame].set_local(local, new_val)?;
-        // FIXME(solson): Run this when setting to Undef? (See previous version of this code.)
-        // if let Value::ByRef(ptr) = self.stack[frame].get_local(local) {
-        //     self.memory.deallocate(ptr)?;
-        // }
-        Ok(())
-    }
-
     pub fn generate_stacktrace(&self, explicit_span: Option<Span>) -> (Vec<FrameInfo>, Span) {
         let mut last_span = None;
         let mut frames = Vec::new();
@@ -1819,12 +1795,12 @@ pub fn generate_stacktrace(&self, explicit_span: Option<Span>) -> (Vec<FrameInfo
         (frames, self.tcx.span)
     }
 
-    pub fn sign_extend(&self, value: u128, ty: Ty<'tcx>) -> EvalResult<'tcx, u128> {
-        super::sign_extend(self.tcx.tcx, value, ty)
+    pub fn sign_extend(&self, value: u128, ty: TyLayout<'_>) -> u128 {
+        super::sign_extend(value, ty)
     }
 
-    pub fn truncate(&self, value: u128, ty: Ty<'tcx>) -> EvalResult<'tcx, u128> {
-        super::truncate(self.tcx.tcx, value, ty)
+    pub fn truncate(&self, value: u128, ty: TyLayout<'_>) -> u128 {
+        super::truncate(value, ty)
     }
 
     fn write_field_name(&self, s: &mut String, ty: Ty<'tcx>, i: usize, variant: usize) -> ::std::fmt::Result {
@@ -1893,34 +1869,45 @@ fn write_field_name(&self, s: &mut String, ty: Ty<'tcx>, i: usize, variant: usiz
             }
         }
     }
-}
 
-impl<'mir, 'tcx> Frame<'mir, 'tcx> {
-    pub fn get_local(&self, local: mir::Local) -> EvalResult<'tcx, Value> {
-        self.locals[local].ok_or_else(|| EvalErrorKind::DeadLocal.into())
+    pub fn storage_live(&mut self, local: mir::Local) -> EvalResult<'tcx, LocalValue> {
+        trace!("{:?} is now live", local);
+
+        let ty = self.frame().mir.local_decls[local].ty;
+        let init = self.init_value(ty)?;
+        // StorageLive *always* kills the value that's currently stored
+        Ok(mem::replace(&mut self.frame_mut().locals[local], LocalValue::Live(init)))
     }
 
+    fn init_value(&mut self, ty: Ty<'tcx>) -> EvalResult<'tcx, Value> {
+        let ty = self.monomorphize(ty, self.substs());
+        let layout = self.layout_of(ty)?;
+        Ok(match layout.abi {
+            layout::Abi::Scalar(..) => Value::Scalar(ScalarMaybeUndef::Undef),
+            layout::Abi::ScalarPair(..) => Value::ScalarPair(
+                ScalarMaybeUndef::Undef,
+                ScalarMaybeUndef::Undef,
+            ),
+            _ => Value::ByRef(self.alloc_ptr(layout)?.into(), layout.align),
+        })
+    }
+}
+
+impl<'mir, 'tcx> Frame<'mir, 'tcx> {
     fn set_local(&mut self, local: mir::Local, value: Value) -> EvalResult<'tcx> {
         match self.locals[local] {
-            None => err!(DeadLocal),
-            Some(ref mut local) => {
+            LocalValue::Dead => err!(DeadLocal),
+            LocalValue::Live(ref mut local) => {
                 *local = value;
                 Ok(())
             }
         }
     }
 
-    pub fn storage_live(&mut self, local: mir::Local) -> Option<Value> {
-        trace!("{:?} is now live", local);
-
-        // StorageLive *always* kills the value that's currently stored
-        mem::replace(&mut self.locals[local], Some(Value::Scalar(Scalar::undef())))
-    }
-
     /// Returns the old value of the local
-    pub fn storage_dead(&mut self, local: mir::Local) -> Option<Value> {
+    pub fn storage_dead(&mut self, local: mir::Local) -> LocalValue {
         trace!("{:?} is now dead", local);
 
-        self.locals[local].take()
+        mem::replace(&mut self.locals[local], LocalValue::Dead)
     }
 }
index 6e5cfe3bb3ee79f0c4b48bfd33fef1768d1b19a9..b62add8a559b41b3d9dc152f5327416e1190ae7e 100644 (file)
@@ -7,7 +7,7 @@
 use rustc::ty::ParamEnv;
 use rustc::ty::query::TyCtxtAt;
 use rustc::ty::layout::{self, Align, TargetDataLayout, Size};
-use rustc::mir::interpret::{Pointer, AllocId, Allocation, AccessKind, Value,
+use rustc::mir::interpret::{Pointer, AllocId, Allocation, AccessKind, Value, ScalarMaybeUndef,
                             EvalResult, Scalar, EvalErrorKind, GlobalId, AllocType};
 pub use rustc::mir::interpret::{write_target_uint, write_target_int, read_target_uint};
 use rustc_data_structures::fx::{FxHashSet, FxHashMap, FxHasher};
@@ -272,10 +272,8 @@ pub fn check_align(&self, ptr: Scalar, required_align: Align) -> EvalResult<'tcx
                 let alloc = self.get(ptr.alloc_id)?;
                 (ptr.offset.bytes(), alloc.align)
             }
-            Scalar::Bits { bits, defined } => {
-                if (defined as u64) < self.pointer_size().bits() {
-                    return err!(ReadUndefBytes);
-                }
+            Scalar::Bits { bits, size } => {
+                assert_eq!(size as u64, self.pointer_size().bytes());
                 // FIXME: what on earth does this line do? docs or fix needed!
                 let v = ((bits as u128) % (1 << self.pointer_size().bytes())) as u64;
                 if v == 0 {
@@ -756,7 +754,7 @@ pub fn write_repeat(&mut self, ptr: Scalar, val: u8, count: Size) -> EvalResult<
         Ok(())
     }
 
-    pub fn read_scalar(&self, ptr: Pointer, ptr_align: Align, size: Size) -> EvalResult<'tcx, Scalar> {
+    pub fn read_scalar(&self, ptr: Pointer, ptr_align: Align, size: Size) -> EvalResult<'tcx, ScalarMaybeUndef> {
         self.check_relocation_edges(ptr, size)?; // Make sure we don't read part of a pointer as a pointer
         let endianness = self.endianness();
         let bytes = self.get_bytes_unchecked(ptr, size, ptr_align.min(self.int_align(size)))?;
@@ -764,7 +762,7 @@ pub fn read_scalar(&self, ptr: Pointer, ptr_align: Align, size: Size) -> EvalRes
         // We must not return Ok() for unaligned pointers!
         if self.check_defined(ptr, size).is_err() {
             // this inflates undefined bytes to the entire scalar, even if only a few bytes are undefined
-            return Ok(Scalar::undef().into());
+            return Ok(ScalarMaybeUndef::Undef);
         }
         // Now we do the actual reading
         let bits = read_target_uint(endianness, bytes).unwrap();
@@ -776,44 +774,60 @@ pub fn read_scalar(&self, ptr: Pointer, ptr_align: Align, size: Size) -> EvalRes
         } else {
             let alloc = self.get(ptr.alloc_id)?;
             match alloc.relocations.get(&ptr.offset) {
-                Some(&alloc_id) => return Ok(Pointer::new(alloc_id, Size::from_bytes(bits as u64)).into()),
+                Some(&alloc_id) => return Ok(ScalarMaybeUndef::Scalar(Pointer::new(alloc_id, Size::from_bytes(bits as u64)).into())),
                 None => {},
             }
         }
         // We don't. Just return the bits.
-        Ok(Scalar::Bits {
+        Ok(ScalarMaybeUndef::Scalar(Scalar::Bits {
             bits,
-            defined: size.bits() as u8,
-        })
+            size: size.bytes() as u8,
+        }))
     }
 
-    pub fn read_ptr_sized(&self, ptr: Pointer, ptr_align: Align) -> EvalResult<'tcx, Scalar> {
+    pub fn read_ptr_sized(&self, ptr: Pointer, ptr_align: Align) -> EvalResult<'tcx, ScalarMaybeUndef> {
         self.read_scalar(ptr, ptr_align, self.pointer_size())
     }
 
-    pub fn write_scalar(&mut self, ptr: Scalar, ptr_align: Align, val: Scalar, size: Size, signed: bool) -> EvalResult<'tcx> {
+    pub fn write_scalar(
+        &mut self,
+        ptr: Scalar,
+        ptr_align: Align,
+        val: ScalarMaybeUndef,
+        type_size: Size,
+        type_align: Align,
+        signed: bool,
+    ) -> EvalResult<'tcx> {
         let endianness = self.endianness();
+        self.check_align(ptr, ptr_align)?;
+
+        let val = match val {
+            ScalarMaybeUndef::Scalar(scalar) => scalar,
+            ScalarMaybeUndef::Undef => return self.mark_definedness(ptr, type_size, false),
+        };
 
         let bytes = match val {
             Scalar::Ptr(val) => {
-                assert_eq!(size, self.pointer_size());
+                assert_eq!(type_size, self.pointer_size());
                 val.offset.bytes() as u128
             }
 
-            Scalar::Bits { bits, defined } if defined as u64 >= size.bits() && size.bits() != 0 => bits,
-
-            Scalar::Bits { .. } => {
-                self.check_align(ptr.into(), ptr_align)?;
-                self.mark_definedness(ptr, size, false)?;
+            Scalar::Bits { size: 0, .. } => {
+                // nothing to do for ZSTs
+                assert_eq!(type_size.bytes(), 0);
                 return Ok(());
             }
+
+            Scalar::Bits { bits, size } => {
+                assert_eq!(size as u64, type_size.bytes());
+                bits
+            },
         };
 
         let ptr = ptr.to_ptr()?;
 
         {
-            let align = self.int_align(size);
-            let dst = self.get_bytes_mut(ptr, size, ptr_align.min(align))?;
+            let dst = self.get_bytes_mut(ptr, type_size, ptr_align.min(type_align))?;
             if signed {
                 write_target_int(endianness, dst, bytes as i128).unwrap();
             } else {
@@ -835,9 +849,9 @@ pub fn write_scalar(&mut self, ptr: Scalar, ptr_align: Align, val: Scalar, size:
         Ok(())
     }
 
-    pub fn write_ptr_sized_unsigned(&mut self, ptr: Pointer, ptr_align: Align, val: Scalar) -> EvalResult<'tcx> {
+    pub fn write_ptr_sized_unsigned(&mut self, ptr: Pointer, ptr_align: Align, val: ScalarMaybeUndef) -> EvalResult<'tcx> {
         let ptr_size = self.pointer_size();
-        self.write_scalar(ptr.into(), ptr_align, val, ptr_size, false)
+        self.write_scalar(ptr.into(), ptr_align, val, ptr_size, ptr_align, false)
     }
 
     fn int_align(&self, size: Size) -> Align {
@@ -984,7 +998,7 @@ pub trait HasMemory<'a, 'mir, 'tcx: 'a + 'mir, M: Machine<'mir, 'tcx>> {
     fn into_ptr(
         &self,
         value: Value,
-    ) -> EvalResult<'tcx, Scalar> {
+    ) -> EvalResult<'tcx, ScalarMaybeUndef> {
         Ok(match value {
             Value::ByRef(ptr, align) => {
                 self.memory().read_ptr_sized(ptr.to_ptr()?, align)?
@@ -997,7 +1011,7 @@ fn into_ptr(
     fn into_ptr_vtable_pair(
         &self,
         value: Value,
-    ) -> EvalResult<'tcx, (Scalar, Pointer)> {
+    ) -> EvalResult<'tcx, (ScalarMaybeUndef, Pointer)> {
         match value {
             Value::ByRef(ref_ptr, align) => {
                 let mem = self.memory();
@@ -1005,11 +1019,11 @@ fn into_ptr_vtable_pair(
                 let vtable = mem.read_ptr_sized(
                     ref_ptr.ptr_offset(mem.pointer_size(), &mem.tcx.data_layout)?.to_ptr()?,
                     align
-                )?.to_ptr()?;
+                )?.unwrap_or_err()?.to_ptr()?;
                 Ok((ptr, vtable))
             }
 
-            Value::ScalarPair(ptr, vtable) => Ok((ptr.into(), vtable.to_ptr()?)),
+            Value::ScalarPair(ptr, vtable) => Ok((ptr, vtable.unwrap_or_err()?.to_ptr()?)),
             _ => bug!("expected ptr and vtable, got {:?}", value),
         }
     }
@@ -1017,7 +1031,7 @@ fn into_ptr_vtable_pair(
     fn into_slice(
         &self,
         value: Value,
-    ) -> EvalResult<'tcx, (Scalar, u64)> {
+    ) -> EvalResult<'tcx, (ScalarMaybeUndef, u64)> {
         match value {
             Value::ByRef(ref_ptr, align) => {
                 let mem = self.memory();
@@ -1025,12 +1039,12 @@ fn into_slice(
                 let len = mem.read_ptr_sized(
                     ref_ptr.ptr_offset(mem.pointer_size(), &mem.tcx.data_layout)?.to_ptr()?,
                     align
-                )?.to_bits(mem.pointer_size())? as u64;
+                )?.unwrap_or_err()?.to_bits(mem.pointer_size())? as u64;
                 Ok((ptr, len))
             }
             Value::ScalarPair(ptr, val) => {
-                let len = val.to_bits(self.memory().pointer_size())?;
-                Ok((ptr.into(), len as u64))
+                let len = val.unwrap_or_err()?.to_bits(self.memory().pointer_size())?;
+                Ok((ptr, len as u64))
             }
             Value::Scalar(_) => bug!("expected ptr and length, got {:?}", value),
         }
index 0c921f66198eb88d7538e9c0fdc1d56cb5700bd6..bc77f6e29d271dd61d7b21585f9c7b3ce75466da 100644 (file)
 mod terminator;
 mod traits;
 
-pub use self::eval_context::{EvalContext, Frame, StackPopCleanup,
-                             TyAndPacked, ValTy};
+pub use self::eval_context::{
+    EvalContext, Frame, StackPopCleanup,
+    TyAndPacked, ValTy,
+};
 
 pub use self::place::{Place, PlaceExtra};
 
 
 pub use self::memory::{write_target_uint, write_target_int, read_target_uint};
 
-use rustc::mir::interpret::{EvalResult, EvalErrorKind};
-use rustc::ty::{Ty, TyCtxt, ParamEnv};
+use rustc::ty::layout::TyLayout;
 
-pub fn sign_extend<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, value: u128, ty: Ty<'tcx>) -> EvalResult<'tcx, u128> {
-    let param_env = ParamEnv::empty();
-    let layout = tcx.layout_of(param_env.and(ty)).map_err(|layout| EvalErrorKind::Layout(layout))?;
+pub fn sign_extend(value: u128, layout: TyLayout<'_>) -> u128 {
     let size = layout.size.bits();
     assert!(layout.abi.is_signed());
     // sign extend
     let shift = 128 - size;
     // shift the unsigned value to the left
     // and back to the right as signed (essentially fills with FF on the left)
-    Ok((((value << shift) as i128) >> shift) as u128)
+    (((value << shift) as i128) >> shift) as u128
 }
 
-pub fn truncate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, value: u128, ty: Ty<'tcx>) -> EvalResult<'tcx, u128> {
-    let param_env = ParamEnv::empty();
-    let layout = tcx.layout_of(param_env.and(ty)).map_err(|layout| EvalErrorKind::Layout(layout))?;
+pub fn truncate(value: u128, layout: TyLayout<'_>) -> u128 {
     let size = layout.size.bits();
     let shift = 128 - size;
     // truncate (shift left to drop out leftover values, shift right to fill with zeroes)
-    Ok((value << shift) >> shift)
+    (value << shift) >> shift
 }
index 8320add715769580611c146e197b535233f98e21..732c85bd0147a18ab56342c2bef097a5c10d8999 100644 (file)
@@ -1,7 +1,7 @@
 use rustc::mir;
 use rustc::ty::{self, Ty, layout};
 use syntax::ast::FloatTy;
-use rustc::ty::layout::LayoutOf;
+use rustc::ty::layout::{LayoutOf, TyLayout};
 use rustc_apfloat::ieee::{Double, Single};
 use rustc_apfloat::Float;
 
@@ -11,7 +11,7 @@
 
 impl<'a, 'mir, 'tcx, M: Machine<'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M> {
     fn binop_with_overflow(
-        &mut self,
+        &self,
         op: mir::BinOp,
         left: ValTy<'tcx>,
         right: ValTy<'tcx>,
@@ -32,7 +32,7 @@ pub fn intrinsic_with_overflow(
         dest_ty: Ty<'tcx>,
     ) -> EvalResult<'tcx> {
         let (val, overflowed) = self.binop_with_overflow(op, left, right)?;
-        let val = Value::ScalarPair(val, Scalar::from_bool(overflowed));
+        let val = Value::ScalarPair(val.into(), Scalar::from_bool(overflowed).into());
         let valty = ValTy {
             value: val,
             ty: dest_ty,
@@ -97,13 +97,13 @@ pub fn binary_op(
             let signed = left_layout.abi.is_signed();
             let mut oflo = (r as u32 as u128) != r;
             let mut r = r as u32;
-            let size = left_layout.size.bits() as u32;
-            oflo |= r >= size;
+            let size = left_layout.size;
+            oflo |= r >= size.bits() as u32;
             if oflo {
-                r %= size;
+                r %= size.bits() as u32;
             }
             let result = if signed {
-                let l = self.sign_extend(l, left_ty)? as i128;
+                let l = self.sign_extend(l, left_layout) as i128;
                 let result = match bin_op {
                     Shl => l << r,
                     Shr => l >> r,
@@ -117,10 +117,10 @@ pub fn binary_op(
                     _ => bug!("it has already been checked that this is a shift op"),
                 }
             };
-            let truncated = self.truncate(result, left_ty)?;
+            let truncated = self.truncate(result, left_layout);
             return Ok((Scalar::Bits {
                 bits: truncated,
-                defined: size as u8,
+                size: size.bytes() as u8,
             }, oflo));
         }
 
@@ -145,8 +145,8 @@ pub fn binary_op(
                 _ => None,
             };
             if let Some(op) = op {
-                let l = self.sign_extend(l, left_ty)? as i128;
-                let r = self.sign_extend(r, right_ty)? as i128;
+                let l = self.sign_extend(l, left_layout) as i128;
+                let r = self.sign_extend(r, right_layout) as i128;
                 return Ok((Scalar::from_bool(op(&l, &r)), false));
             }
             let op: Option<fn(i128, i128) -> (i128, bool)> = match bin_op {
@@ -160,14 +160,14 @@ pub fn binary_op(
                 _ => None,
             };
             if let Some(op) = op {
-                let l128 = self.sign_extend(l, left_ty)? as i128;
-                let r = self.sign_extend(r, right_ty)? as i128;
-                let size = left_layout.size.bits();
+                let l128 = self.sign_extend(l, left_layout) as i128;
+                let r = self.sign_extend(r, right_layout) as i128;
+                let size = left_layout.size;
                 match bin_op {
                     Rem | Div => {
                         // int_min / -1
-                        if r == -1 && l == (1 << (size - 1)) {
-                            return Ok((Scalar::Bits { bits: l, defined: size as u8 }, true));
+                        if r == -1 && l == (1 << (size.bits() - 1)) {
+                            return Ok((Scalar::Bits { bits: l, size: size.bytes() as u8 }, true));
                         }
                     },
                     _ => {},
@@ -175,27 +175,27 @@ pub fn binary_op(
                 trace!("{}, {}, {}", l, l128, r);
                 let (result, mut oflo) = op(l128, r);
                 trace!("{}, {}", result, oflo);
-                if !oflo && size != 128 {
-                    let max = 1 << (size - 1);
+                if !oflo && size.bits() != 128 {
+                    let max = 1 << (size.bits() - 1);
                     oflo = result >= max || result < -max;
                 }
                 let result = result as u128;
-                let truncated = self.truncate(result, left_ty)?;
+                let truncated = self.truncate(result, left_layout);
                 return Ok((Scalar::Bits {
                     bits: truncated,
-                    defined: size as u8,
+                    size: size.bytes() as u8,
                 }, oflo));
             }
         }
 
         if let ty::TyFloat(fty) = left_ty.sty {
             macro_rules! float_math {
-                ($ty:path, $bitsize:expr) => {{
+                ($ty:path, $size:expr) => {{
                     let l = <$ty>::from_bits(l);
                     let r = <$ty>::from_bits(r);
                     let bitify = |res: ::rustc_apfloat::StatusAnd<$ty>| Scalar::Bits {
                         bits: res.value.to_bits(),
-                        defined: $bitsize,
+                        size: $size,
                     };
                     let val = match bin_op {
                         Eq => Scalar::from_bool(l == r),
@@ -215,12 +215,12 @@ macro_rules! float_math {
                 }};
             }
             match fty {
-                FloatTy::F32 => float_math!(Single, 32),
-                FloatTy::F64 => float_math!(Double, 64),
+                FloatTy::F32 => float_math!(Single, 4),
+                FloatTy::F64 => float_math!(Double, 8),
             }
         }
 
-        let bit_width = self.layout_of(left_ty).unwrap().size.bits() as u8;
+        let size = self.layout_of(left_ty).unwrap().size.bytes() as u8;
 
         // only ints left
         let val = match bin_op {
@@ -232,9 +232,9 @@ macro_rules! float_math {
             Gt => Scalar::from_bool(l > r),
             Ge => Scalar::from_bool(l >= r),
 
-            BitOr => Scalar::Bits { bits: l | r, defined: bit_width },
-            BitAnd => Scalar::Bits { bits: l & r, defined: bit_width },
-            BitXor => Scalar::Bits { bits: l ^ r, defined: bit_width },
+            BitOr => Scalar::Bits { bits: l | r, size },
+            BitAnd => Scalar::Bits { bits: l & r, size },
+            BitXor => Scalar::Bits { bits: l ^ r, size },
 
             Add | Sub | Mul | Rem | Div => {
                 let op: fn(u128, u128) -> (u128, bool) = match bin_op {
@@ -248,10 +248,10 @@ macro_rules! float_math {
                     _ => bug!(),
                 };
                 let (result, oflo) = op(l, r);
-                let truncated = self.truncate(result, left_ty)?;
+                let truncated = self.truncate(result, left_layout);
                 return Ok((Scalar::Bits {
                     bits: truncated,
-                    defined: bit_width,
+                    size,
                 }, oflo || truncated != result));
             }
 
@@ -275,17 +275,16 @@ pub fn unary_op(
         &self,
         un_op: mir::UnOp,
         val: Scalar,
-        ty: Ty<'tcx>,
+        layout: TyLayout<'tcx>,
     ) -> EvalResult<'tcx, Scalar> {
         use rustc::mir::UnOp::*;
         use rustc_apfloat::ieee::{Single, Double};
         use rustc_apfloat::Float;
 
-        let size = self.layout_of(ty)?.size;
+        let size = layout.size;
         let bytes = val.to_bits(size)?;
-        let size = size.bits();
 
-        let result_bytes = match (un_op, &ty.sty) {
+        let result_bytes = match (un_op, &layout.ty.sty) {
 
             (Not, ty::TyBool) => !val.to_bool()? as u128,
 
@@ -294,13 +293,13 @@ pub fn unary_op(
             (Neg, ty::TyFloat(FloatTy::F32)) => Single::to_bits(-Single::from_bits(bytes)),
             (Neg, ty::TyFloat(FloatTy::F64)) => Double::to_bits(-Double::from_bits(bytes)),
 
-            (Neg, _) if bytes == (1 << (size - 1)) => return err!(OverflowNeg),
+            (Neg, _) if bytes == (1 << (size.bits() - 1)) => return err!(OverflowNeg),
             (Neg, _) => (-(bytes as i128)) as u128,
         };
 
         Ok(Scalar::Bits {
-            bits: self.truncate(result_bytes, ty)?,
-            defined: size as u8,
+            bits: self.truncate(result_bytes, layout),
+            size: size.bytes() as u8,
         })
     }
 }
index 59bf2ae6c0fe7721ea6c264715d87d94d4ad68f3..91c2519230695a08c8b621c53b387029312a417e 100644 (file)
@@ -3,7 +3,7 @@
 use rustc::ty::layout::{self, Align, LayoutOf, TyLayout};
 use rustc_data_structures::indexed_vec::Idx;
 
-use rustc::mir::interpret::{GlobalId, Value, Scalar, EvalResult, Pointer};
+use rustc::mir::interpret::{GlobalId, Value, Scalar, EvalResult, Pointer, ScalarMaybeUndef};
 use super::{EvalContext, Machine, ValTy};
 use interpret::memory::HasMemory;
 
@@ -14,7 +14,7 @@ pub enum Place {
         /// A place may have an invalid (integral or undef) pointer,
         /// since it might be turned back into a reference
         /// before ever being dereferenced.
-        ptr: Scalar,
+        ptr: ScalarMaybeUndef,
         align: Align,
         extra: PlaceExtra,
     },
@@ -35,10 +35,10 @@ pub enum PlaceExtra {
 impl<'tcx> Place {
     /// Produces a Place that will error if attempted to be read from
     pub fn undef() -> Self {
-        Self::from_scalar_ptr(Scalar::undef().into(), Align::from_bytes(1, 1).unwrap())
+        Self::from_scalar_ptr(ScalarMaybeUndef::Undef, Align::from_bytes(1, 1).unwrap())
     }
 
-    pub fn from_scalar_ptr(ptr: Scalar, align: Align) -> Self {
+    pub fn from_scalar_ptr(ptr: ScalarMaybeUndef, align: Align) -> Self {
         Place::Ptr {
             ptr,
             align,
@@ -47,10 +47,10 @@ pub fn from_scalar_ptr(ptr: Scalar, align: Align) -> Self {
     }
 
     pub fn from_ptr(ptr: Pointer, align: Align) -> Self {
-        Self::from_scalar_ptr(ptr.into(), align)
+        Self::from_scalar_ptr(ScalarMaybeUndef::Scalar(ptr.into()), align)
     }
 
-    pub fn to_ptr_align_extra(self) -> (Scalar, Align, PlaceExtra) {
+    pub fn to_ptr_align_extra(self) -> (ScalarMaybeUndef, Align, PlaceExtra) {
         match self {
             Place::Ptr { ptr, align, extra } => (ptr, align, extra),
             _ => bug!("to_ptr_and_extra: expected Place::Ptr, got {:?}", self),
@@ -58,7 +58,7 @@ pub fn to_ptr_align_extra(self) -> (Scalar, Align, PlaceExtra) {
         }
     }
 
-    pub fn to_ptr_align(self) -> (Scalar, Align) {
+    pub fn to_ptr_align(self) -> (ScalarMaybeUndef, Align) {
         let (ptr, align, _extra) = self.to_ptr_align_extra();
         (ptr, align)
     }
@@ -66,7 +66,7 @@ pub fn to_ptr_align(self) -> (Scalar, Align) {
     pub fn to_ptr(self) -> EvalResult<'tcx, Pointer> {
         // At this point, we forget about the alignment information -- the place has been turned into a reference,
         // and no matter where it came from, it now must be aligned.
-        self.to_ptr_align().0.to_ptr()
+        self.to_ptr_align().0.unwrap_or_err()?.to_ptr()
     }
 
     pub(super) fn elem_ty_and_len(
@@ -106,7 +106,7 @@ pub fn try_read_place(
             // Might allow this in the future, right now there's no way to do this from Rust code anyway
             Local(mir::RETURN_PLACE) => err!(ReadFromReturnPointer),
             // Directly reading a local will always succeed
-            Local(local) => self.frame().get_local(local).map(Some),
+            Local(local) => self.frame().locals[local].access().map(Some),
             // No fast path for statics. Reading from statics is rare and would require another
             // Machine function to handle differently in miri.
             Promoted(_) |
@@ -129,7 +129,7 @@ pub fn read_field(
         let field = base_layout.field(self, field_index)?;
         if field.size.bytes() == 0 {
             return Ok((
-                Value::Scalar(Scalar::undef()),
+                Value::Scalar(ScalarMaybeUndef::Scalar(Scalar::Bits { bits: 0, size: 0 })),
                 field,
             ));
         }
@@ -197,9 +197,9 @@ pub fn read_place(&self, place: Place) -> EvalResult<'tcx, Value> {
         match place {
             Place::Ptr { ptr, align, extra } => {
                 assert_eq!(extra, PlaceExtra::None);
-                Ok(Value::ByRef(ptr, align))
+                Ok(Value::ByRef(ptr.unwrap_or_err()?, align))
             }
-            Place::Local { frame, local } => self.stack[frame].get_local(local),
+            Place::Local { frame, local } => self.stack[frame].locals[local].access(),
         }
     }
 
@@ -220,7 +220,7 @@ pub fn eval_place(&mut self, mir_place: &mir::Place<'tcx>) -> EvalResult<'tcx, P
                 })?;
                 if let Value::ByRef(ptr, align) = val {
                     Place::Ptr {
-                        ptr,
+                        ptr: ptr.into(),
                         align,
                         extra: PlaceExtra::None,
                     }
@@ -238,7 +238,7 @@ pub fn eval_place(&mut self, mir_place: &mir::Place<'tcx>) -> EvalResult<'tcx, P
                 };
                 let alloc = Machine::init_static(self, cid)?;
                 Place::Ptr {
-                    ptr: Scalar::Ptr(alloc.into()),
+                    ptr: ScalarMaybeUndef::Scalar(Scalar::Ptr(alloc.into())),
                     align: layout.align,
                     extra: PlaceExtra::None,
                 }
@@ -276,14 +276,13 @@ pub fn place_field(
         let (base_ptr, base_align, base_extra) = match base {
             Place::Ptr { ptr, align, extra } => (ptr, align, extra),
             Place::Local { frame, local } => {
-                match (&self.stack[frame].get_local(local)?, &base_layout.abi) {
+                match (self.stack[frame].locals[local].access()?, &base_layout.abi) {
                     // in case the field covers the entire type, just return the value
-                    (&Value::Scalar(_), &layout::Abi::Scalar(_)) |
-                    (&Value::ScalarPair(..), &layout::Abi::ScalarPair(..))
-                        if offset.bytes() == 0 && field.size == base_layout.size =>
-                    {
-                        return Ok((base, field));
-                    }
+                    (Value::Scalar(_), &layout::Abi::Scalar(_)) |
+                    (Value::ScalarPair(..), &layout::Abi::ScalarPair(..))
+                    if offset.bytes() == 0 && field.size == base_layout.size => {
+                        return Ok((base, field))
+                    },
                     _ => self.force_allocation(base)?.to_ptr_align_extra(),
                 }
             }
@@ -413,7 +412,7 @@ pub fn eval_place_projection(
             }
 
             Index(local) => {
-                let value = self.frame().get_local(local)?;
+                let value = self.frame().locals[local].access()?;
                 let ty = self.tcx.types.usize;
                 let n = self
                     .value_to_scalar(ValTy { value, ty })?
index db90714d0e6231d7b747fa142f8c6e21d112ac00..57b56db14bb4b719e00a19560a35120108d78211 100644 (file)
@@ -90,7 +90,7 @@ fn statement(&mut self, stmt: &mir::Statement<'tcx>) -> EvalResult<'tcx> {
 
             // Mark locals as alive
             StorageLive(local) => {
-                let old_val = self.frame_mut().storage_live(local);
+                let old_val = self.storage_live(local)?;
                 self.deallocate_local(old_val)?;
             }
 
index d750c1f47a662f5deb968d4289755e4d96f1f2d3..fe8071897c34874bd2b4ecc7178f6f3bd08af670 100644 (file)
@@ -2,7 +2,7 @@
 use rustc::ty::{self, Ty};
 use syntax::codemap::Span;
 
-use rustc::mir::interpret::{EvalResult, Scalar, Value};
+use rustc::mir::interpret::{EvalResult, Value};
 use interpret::{Machine, ValTy, EvalContext, Place, PlaceExtra};
 
 impl<'a, 'mir, 'tcx, M: Machine<'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M> {
@@ -33,7 +33,7 @@ pub(crate) fn drop_place(
                 ptr,
                 align: _,
                 extra: PlaceExtra::None,
-            } => ptr.to_value(),
+            } => Value::Scalar(ptr),
             _ => bug!("force_allocation broken"),
         };
         self.drop(val, instance, ty, span, target)
@@ -51,17 +51,10 @@ fn drop(
 
         let instance = match ty.sty {
             ty::TyDynamic(..) => {
-                let vtable = match arg {
-                    Value::ScalarPair(_, Scalar::Ptr(vtable)) => vtable,
-                    _ => bug!("expected fat ptr, got {:?}", arg),
-                };
-                match self.read_drop_type_from_vtable(vtable)? {
-                    Some(func) => func,
-                    // no drop fn -> bail out
-                    None => {
-                        self.goto_block(target);
-                        return Ok(())
-                    },
+                if let Value::ScalarPair(_, vtable) = arg {
+                    self.read_drop_type_from_vtable(vtable.unwrap_or_err()?.to_ptr()?)?
+                } else {
+                    bug!("expected fat ptr, got {:?}", arg);
                 }
             }
             _ => instance,
index 56dd3f603b692f63e615b109b117e540c88b2fe8..682e384da3936eb6caae8af7039e019d40805556 100644 (file)
@@ -4,7 +4,7 @@
 use syntax::codemap::Span;
 use rustc_target::spec::abi::Abi;
 
-use rustc::mir::interpret::{EvalResult, Scalar};
+use rustc::mir::interpret::{EvalResult, Scalar, Value};
 use super::{EvalContext, Place, Machine, ValTy};
 
 use rustc_data_structures::indexed_vec::Idx;
@@ -47,7 +47,7 @@ pub(super) fn eval_terminator(
 
                 for (index, &const_int) in values.iter().enumerate() {
                     // Compare using binary_op
-                    let const_int = Scalar::Bits { bits: const_int, defined: 128 };
+                    let const_int = Scalar::Bits { bits: const_int, size: discr_layout.size.bytes() as u8 };
                     let res = self.binary_op(mir::BinOp::Eq,
                         discr_prim, discr_val.ty,
                         const_int, discr_val.ty
@@ -392,12 +392,12 @@ fn eval_fn_call(
                 let fn_ptr = self.memory.read_ptr_sized(
                     vtable.offset(ptr_size * (idx as u64 + 3), &self)?,
                     ptr_align
-                )?.to_ptr()?;
+                )?.unwrap_or_err()?.to_ptr()?;
                 let instance = self.memory.get_fn(fn_ptr)?;
                 let mut args = args.to_vec();
                 let ty = self.layout_of(args[0].ty)?.field(&self, 0)?.ty;
                 args[0].ty = ty;
-                args[0].value = ptr.to_value();
+                args[0].value = Value::Scalar(ptr);
                 // recurse with concrete function
                 self.eval_fn_call(instance, destination, &args, span, sig)
             }
index b6c7feda19fa813377fff50213a3b046deb3b96c..84583680988b7c093c368eeb93cfd8d3c2aad59e 100644 (file)
@@ -1,6 +1,6 @@
 use rustc::ty::{self, Ty};
 use rustc::ty::layout::{Size, Align, LayoutOf};
-use rustc::mir::interpret::{Scalar, Value, Pointer, EvalResult};
+use rustc::mir::interpret::{Scalar, Pointer, EvalResult};
 
 use syntax::ast::Mutability;
 
@@ -36,25 +36,25 @@ pub fn get_vtable(
 
         let drop = ::monomorphize::resolve_drop_in_place(*self.tcx, ty);
         let drop = self.memory.create_fn_alloc(drop);
-        self.memory.write_ptr_sized_unsigned(vtable, ptr_align, drop.into())?;
+        self.memory.write_ptr_sized_unsigned(vtable, ptr_align, Scalar::Ptr(drop).into())?;
 
         let size_ptr = vtable.offset(ptr_size, &self)?;
         self.memory.write_ptr_sized_unsigned(size_ptr, ptr_align, Scalar::Bits {
             bits: size as u128,
-            defined: ptr_size.bits() as u8,
-        })?;
+            size: ptr_size.bytes() as u8,
+        }.into())?;
         let align_ptr = vtable.offset(ptr_size * 2, &self)?;
         self.memory.write_ptr_sized_unsigned(align_ptr, ptr_align, Scalar::Bits {
             bits: align as u128,
-            defined: ptr_size.bits() as u8,
-        })?;
+            size: ptr_size.bytes() as u8,
+        }.into())?;
 
         for (i, method) in methods.iter().enumerate() {
             if let Some((def_id, substs)) = *method {
                 let instance = self.resolve(def_id, substs)?;
                 let fn_ptr = self.memory.create_fn_alloc(instance);
                 let method_ptr = vtable.offset(ptr_size * (3 + i as u64), &self)?;
-                self.memory.write_ptr_sized_unsigned(method_ptr, ptr_align, fn_ptr.into())?;
+                self.memory.write_ptr_sized_unsigned(method_ptr, ptr_align, Scalar::Ptr(fn_ptr).into())?;
             }
         }
 
@@ -69,16 +69,11 @@ pub fn get_vtable(
     pub fn read_drop_type_from_vtable(
         &self,
         vtable: Pointer,
-    ) -> EvalResult<'tcx, Option<ty::Instance<'tcx>>> {
+    ) -> EvalResult<'tcx, ty::Instance<'tcx>> {
         // we don't care about the pointee type, we just want a pointer
         let pointer_align = self.tcx.data_layout.pointer_align;
-        let pointer_size = self.tcx.data_layout.pointer_size.bits() as u8;
-        match self.read_ptr(vtable, pointer_align, self.tcx.mk_nil_ptr())? {
-            // some values don't need to call a drop impl, so the value is null
-            Value::Scalar(Scalar::Bits { bits: 0, defined} ) if defined == pointer_size => Ok(None),
-            Value::Scalar(Scalar::Ptr(drop_fn)) => self.memory.get_fn(drop_fn).map(Some),
-            _ => err!(ReadBytesAsPointer),
-        }
+        let drop_fn = self.memory.read_ptr_sized(vtable, pointer_align)?.unwrap_or_err()?.to_ptr()?;
+        self.memory.get_fn(drop_fn)
     }
 
     pub fn read_size_and_align_from_vtable(
@@ -87,11 +82,11 @@ pub fn read_size_and_align_from_vtable(
     ) -> EvalResult<'tcx, (Size, Align)> {
         let pointer_size = self.memory.pointer_size();
         let pointer_align = self.tcx.data_layout.pointer_align;
-        let size = self.memory.read_ptr_sized(vtable.offset(pointer_size, self)?, pointer_align)?.to_bits(pointer_size)? as u64;
+        let size = self.memory.read_ptr_sized(vtable.offset(pointer_size, self)?, pointer_align)?.unwrap_or_err()?.to_bits(pointer_size)? as u64;
         let align = self.memory.read_ptr_sized(
             vtable.offset(pointer_size * 2, self)?,
             pointer_align
-        )?.to_bits(pointer_size)? as u64;
+        )?.unwrap_or_err()?.to_bits(pointer_size)? as u64;
         Ok((Size::from_bytes(size), Align::from_bytes(align, align).unwrap()))
     }
 }
index 6283ee9cfe648ed9f60ac54bad1df188722ba6c8..97f1f2a76ca2b71ef2b346aafa812604ecdd5ed5 100644 (file)
 
 use rustc::hir::map as hir_map;
 use rustc::hir::def_id::DefId;
-use rustc::mir::interpret::{AllocId, ConstValue};
+use rustc::mir::interpret::{AllocId, ConstValue, ScalarMaybeUndef};
 use rustc::middle::lang_items::{ExchangeMallocFnLangItem, StartFnLangItem};
 use rustc::ty::subst::Substs;
 use rustc::ty::{self, TypeFoldable, Ty, TyCtxt, GenericParamDefKind};
@@ -1264,11 +1264,11 @@ fn collect_const<'a, 'tcx>(
     };
     match val {
         ConstValue::Unevaluated(..) => bug!("const eval yielded unevaluated const"),
-        ConstValue::ScalarPair(Scalar::Ptr(a), Scalar::Ptr(b)) => {
+        ConstValue::ScalarPair(Scalar::Ptr(a), ScalarMaybeUndef::Scalar(Scalar::Ptr(b))) => {
             collect_miri(tcx, a.alloc_id, output);
             collect_miri(tcx, b.alloc_id, output);
         }
-        ConstValue::ScalarPair(_, Scalar::Ptr(ptr)) |
+        ConstValue::ScalarPair(_, ScalarMaybeUndef::Scalar(Scalar::Ptr(ptr))) |
         ConstValue::ScalarPair(Scalar::Ptr(ptr), _) |
         ConstValue::Scalar(Scalar::Ptr(ptr)) =>
             collect_miri(tcx, ptr.alloc_id, output),
index 9902fe98cc011ecd2cb709478ed001ddceb70a0e..05e51c5430d7fe5aafd0f4b9741974e09722dc70 100644 (file)
@@ -17,7 +17,7 @@
 use rustc::mir::{NullOp, StatementKind, Statement, BasicBlock, LocalKind};
 use rustc::mir::{TerminatorKind, ClearCrossCrate, SourceInfo, BinOp, ProjectionElem};
 use rustc::mir::visit::{Visitor, PlaceContext};
-use rustc::mir::interpret::{ConstEvalErr, EvalErrorKind};
+use rustc::mir::interpret::{ConstEvalErr, EvalErrorKind, ScalarMaybeUndef};
 use rustc::ty::{TyCtxt, self, Instance};
 use rustc::mir::interpret::{Value, Scalar, GlobalId, EvalResult};
 use interpret::EvalContext;
@@ -368,8 +368,8 @@ fn const_prop(
                 type_size_of(self.tcx, self.param_env, ty).and_then(|n| Some((
                     Value::Scalar(Scalar::Bits {
                         bits: n as u128,
-                        defined: self.tcx.data_layout.pointer_size.bits() as u8,
-                    }),
+                        size: self.tcx.data_layout.pointer_size.bytes() as u8,
+                    }.into()),
                     self.tcx.layout_of(self.param_env.and(self.tcx.types.usize)).ok()?,
                     span,
                 )))
@@ -390,8 +390,8 @@ fn const_prop(
                 let prim = self.use_ecx(source_info, |this| {
                     this.ecx.value_to_scalar(ValTy { value: val.0, ty: val.1.ty })
                 })?;
-                let val = self.use_ecx(source_info, |this| this.ecx.unary_op(op, prim, val.1.ty))?;
-                Some((Value::Scalar(val), place_layout, span))
+                let val = self.use_ecx(source_info, |this| this.ecx.unary_op(op, prim, val.1))?;
+                Some((Value::Scalar(val.into()), place_layout, span))
             }
             Rvalue::CheckedBinaryOp(op, ref left, ref right) |
             Rvalue::BinaryOp(op, ref left, ref right) => {
@@ -449,8 +449,8 @@ fn const_prop(
                 })?;
                 let val = if let Rvalue::CheckedBinaryOp(..) = *rvalue {
                     Value::ScalarPair(
-                        val,
-                        Scalar::from_bool(overflow),
+                        val.into(),
+                        Scalar::from_bool(overflow).into(),
                     )
                 } else {
                     if overflow {
@@ -458,7 +458,7 @@ fn const_prop(
                         let _: Option<()> = self.use_ecx(source_info, |_| Err(err));
                         return None;
                     }
-                    Value::Scalar(val)
+                    Value::Scalar(val.into())
                 };
                 Some((val, place_layout, span))
             },
@@ -576,7 +576,7 @@ fn visit_terminator_kind(
         if let TerminatorKind::Assert { expected, msg, cond, .. } = kind {
             if let Some(value) = self.eval_operand(cond, source_info) {
                 trace!("assertion on {:?} should be {:?}", value, expected);
-                if Value::Scalar(Scalar::from_bool(*expected)) != value.0 {
+                if Value::Scalar(Scalar::from_bool(*expected).into()) != value.0 {
                     // poison all places this operand references so that further code
                     // doesn't use the invalid value
                     match cond {
@@ -613,14 +613,18 @@ fn visit_terminator_kind(
                                 .eval_operand(len, source_info)
                                 .expect("len must be const");
                             let len = match len.0 {
-                                Value::Scalar(Scalar::Bits { bits, ..}) => bits,
+                                Value::Scalar(ScalarMaybeUndef::Scalar(Scalar::Bits {
+                                    bits, ..
+                                })) => bits,
                                 _ => bug!("const len not primitive: {:?}", len),
                             };
                             let index = self
                                 .eval_operand(index, source_info)
                                 .expect("index must be const");
                             let index = match index.0 {
-                                Value::Scalar(Scalar::Bits { bits, .. }) => bits,
+                                Value::Scalar(ScalarMaybeUndef::Scalar(Scalar::Bits {
+                                    bits, ..
+                                })) => bits,
                                 _ => bug!("const index not primitive: {:?}", index),
                             };
                             format!(
index 09ebf1681c5e04540f1e2114ee38b26af06f68a4..10376d5780908d6ed1f16050b09d2823450f10f8 100644 (file)
@@ -16,7 +16,7 @@ union Foo {
 
 enum Bar {
     Boo = [unsafe { Foo { b: () }.a }; 4][3],
-    //~^ ERROR constant evaluation of enum discriminant resulted in non-integer
+    //~^ ERROR could not evaluate enum discriminant
 }
 
 fn main() {
diff --git a/src/test/ui/const-eval/simple_with_undef.rs b/src/test/ui/const-eval/simple_with_undef.rs
new file mode 100644 (file)
index 0000000..d18059f
--- /dev/null
@@ -0,0 +1,16 @@
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// compile-pass
+
+const PARSE_BOOL: Option<&'static str> = None;
+static FOO: (Option<&str>, u32) = (PARSE_BOOL, 42);
+
+fn main() {}
index 41981e1256791551bba81f345f8e89ba7e48c285..5723f4a4159aa5170a8020efe2404afd09398fd8 100644 (file)
@@ -34,7 +34,7 @@ const fn read_field2() -> Field2 {
 }
 
 const fn read_field3() -> Field3 {
-    const FIELD3: Field3 = unsafe { UNION.field3 }; //~ ERROR exhibits undefined behavior
+    const FIELD3: Field3 = unsafe { UNION.field3 }; //~ ERROR cannot be used
     FIELD3
 }
 
index 94896d6c22577b4b7109f997caf440414926c8e5..811450c8cba4757afc3b52765633e357a00aec7c 100644 (file)
@@ -1,11 +1,10 @@
-error[E0080]: this constant likely exhibits undefined behavior
+error: this constant cannot be used
   --> $DIR/union-const-eval-field.rs:37:5
    |
-LL |     const FIELD3: Field3 = unsafe { UNION.field3 }; //~ ERROR exhibits undefined behavior
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered undefined bytes
+LL |     const FIELD3: Field3 = unsafe { UNION.field3 }; //~ ERROR cannot be used
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ attempted to read undefined bytes
    |
-   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
+   = note: #[deny(const_err)] on by default
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0080`.
index 426710389eb2951e386426857e1eca1000bbca89..0cdb78c97803c7f80cf3ef89614173154971812f 100644 (file)
@@ -20,9 +20,9 @@ union DummyUnion {
 
 const UNION: DummyUnion = DummyUnion { field1: 1065353216 };
 
-const FIELD3: Field3 = unsafe { UNION.field3 }; //~ ERROR this constant likely exhibits undefined
+const FIELD3: Field3 = unsafe { UNION.field3 }; //~ ERROR this constant cannot be used
 
-const FIELD_PATH: Struct = Struct { //~ ERROR this constant likely exhibits undefined behavior
+const FIELD_PATH: Struct = Struct { //~ ERROR this constant cannot be used
     a: 42,
     b: unsafe { UNION.field3 },
 };
index 58e9033a071a1209a01b1caf041e14697cd55ab3..e8a7b2f500561e31cbee5926bd8b7d8893e1d003 100644 (file)
@@ -1,21 +1,19 @@
-error[E0080]: this constant likely exhibits undefined behavior
+error: this constant cannot be used
   --> $DIR/union-ice.rs:23:1
    |
-LL | const FIELD3: Field3 = unsafe { UNION.field3 }; //~ ERROR this constant likely exhibits undefined
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered undefined bytes
+LL | const FIELD3: Field3 = unsafe { UNION.field3 }; //~ ERROR this constant cannot be used
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ attempted to read undefined bytes
    |
-   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
+   = note: #[deny(const_err)] on by default
 
-error[E0080]: this constant likely exhibits undefined behavior
+error: this constant cannot be used
   --> $DIR/union-ice.rs:25:1
    |
-LL | / const FIELD_PATH: Struct = Struct { //~ ERROR this constant likely exhibits undefined behavior
+LL | / const FIELD_PATH: Struct = Struct { //~ ERROR this constant cannot be used
 LL | |     a: 42,
 LL | |     b: unsafe { UNION.field3 },
 LL | | };
-   | |__^ type validation failed: encountered undefined bytes at .b
-   |
-   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rust compiler repository if you believe it should not be considered undefined behavior
+   | |__^ attempted to read undefined bytes
 
 error[E0080]: this constant likely exhibits undefined behavior
   --> $DIR/union-ice.rs:35:1