Auto merge of #50690 - oli-obk:mir_stuff, r=eddyb

Ensure that statics are always ByRef

Statics aren't values to be used, they are names for memory locations.

r? @eddyb

cc @Zoxc

fixes #50706

Author: bors

src/librustc/ich/impls_ty.rs

@@ -401,8 +401,9 @@ for ::mir::interpret::ConstValue<'gcx> {
                 a.hash_stable(hcx, hasher);
                 b.hash_stable(hcx, hasher);
             }
-            ByRef(alloc) => {
+            ByRef(alloc, offset) => {
                 alloc.hash_stable(hcx, hasher);
+                offset.hash_stable(hcx, hasher);
             }
         }
     }

src/librustc/mir/interpret/error.rs

@@ -2,6 +2,7 @@ use std::{fmt, env};
 
 use mir;
 use ty::{FnSig, Ty, layout};
+use ty::layout::{Size, Align};
 
 use super::{
     MemoryPointer, Lock, AccessKind
@@ -47,7 +48,7 @@ pub enum EvalErrorKind<'tcx, O> {
     PointerOutOfBounds {
         ptr: MemoryPointer,
         access: bool,
-        allocation_size: u64,
+        allocation_size: Size,
     },
     InvalidNullPointerUsage,
     ReadPointerAsBytes,
@@ -71,8 +72,8 @@ pub enum EvalErrorKind<'tcx, O> {
     TlsOutOfBounds,
     AbiViolation(String),
     AlignmentCheckFailed {
-        required: u64,
-        has: u64,
+        required: Align,
+        has: Align,
     },
     MemoryLockViolation {
         ptr: MemoryPointer,
@@ -108,7 +109,7 @@ pub enum EvalErrorKind<'tcx, O> {
     DeallocatedWrongMemoryKind(String, String),
     ReallocateNonBasePtr,
     DeallocateNonBasePtr,
-    IncorrectAllocationInformation(u64, usize, u64, u64),
+    IncorrectAllocationInformation(Size, Size, Align, Align),
     Layout(layout::LayoutError<'tcx>),
     HeapAllocZeroBytes,
     HeapAllocNonPowerOfTwoAlignment(u64),
@@ -269,7 +270,7 @@ impl<'tcx, O: fmt::Debug> fmt::Debug for EvalErrorKind<'tcx, O> {
             PointerOutOfBounds { ptr, access, allocation_size } => {
                 write!(f, "{} at offset {}, outside bounds of allocation {} which has size {}",
                        if access { "memory access" } else { "pointer computed" },
-                       ptr.offset, ptr.alloc_id, allocation_size)
+                       ptr.offset.bytes(), ptr.alloc_id, allocation_size.bytes())
             },
             MemoryLockViolation { ptr, len, frame, access, ref lock } => {
                 write!(f, "{:?} access by frame {} at {:?}, size {}, is in conflict with lock {:?}",
@@ -305,7 +306,7 @@ impl<'tcx, O: fmt::Debug> fmt::Debug for EvalErrorKind<'tcx, O> {
                 write!(f, "tried to interpret an invalid 32-bit value as a char: {}", c),
             AlignmentCheckFailed { required, has } =>
                write!(f, "tried to access memory with alignment {}, but alignment {} is required",
-                      has, required),
+                      has.abi(), required.abi()),
             TypeNotPrimitive(ty) =>
                 write!(f, "expected primitive type, got {}", ty),
             Layout(ref err) =>
@@ -315,7 +316,7 @@ impl<'tcx, O: fmt::Debug> fmt::Debug for EvalErrorKind<'tcx, O> {
             MachineError(ref inner) =>
                 write!(f, "{}", inner),
             IncorrectAllocationInformation(size, size2, align, align2) =>
-                write!(f, "incorrect alloc info: expected size {} and align {}, got size {} and align {}", size, align, size2, align2),
+                write!(f, "incorrect alloc info: expected size {} and align {}, got size {} and align {}", size.bytes(), align.abi(), size2.bytes(), align2.abi()),
             _ => write!(f, "{}", self.description()),
         }
     }

src/librustc/mir/interpret/mod.rs

@@ -17,7 +17,7 @@ use std::fmt;
 use mir;
 use hir::def_id::DefId;
 use ty::{self, TyCtxt};
-use ty::layout::{self, Align, HasDataLayout};
+use ty::layout::{self, Align, HasDataLayout, Size};
 use middle::region;
 use std::iter;
 use std::io;
@@ -109,42 +109,42 @@ impl<T: layout::HasDataLayout> PointerArithmetic for T {}
 #[derive(Copy, Clone, Debug, Eq, PartialEq, RustcEncodable, RustcDecodable, Hash)]
 pub struct MemoryPointer {
     pub alloc_id: AllocId,
-    pub offset: u64,
+    pub offset: Size,
 }
 
 impl<'tcx> MemoryPointer {
-    pub fn new(alloc_id: AllocId, offset: u64) -> Self {
+    pub fn new(alloc_id: AllocId, offset: Size) -> Self {
         MemoryPointer { alloc_id, offset }
     }
 
     pub(crate) fn wrapping_signed_offset<C: HasDataLayout>(self, i: i64, cx: C) -> Self {
         MemoryPointer::new(
             self.alloc_id,
-            cx.data_layout().wrapping_signed_offset(self.offset, i),
+            Size::from_bytes(cx.data_layout().wrapping_signed_offset(self.offset.bytes(), i)),
         )
     }
 
     pub fn overflowing_signed_offset<C: HasDataLayout>(self, i: i128, cx: C) -> (Self, bool) {
-        let (res, over) = cx.data_layout().overflowing_signed_offset(self.offset, i);
-        (MemoryPointer::new(self.alloc_id, res), over)
+        let (res, over) = cx.data_layout().overflowing_signed_offset(self.offset.bytes(), i);
+        (MemoryPointer::new(self.alloc_id, Size::from_bytes(res)), over)
     }
 
     pub(crate) fn signed_offset<C: HasDataLayout>(self, i: i64, cx: C) -> EvalResult<'tcx, Self> {
         Ok(MemoryPointer::new(
             self.alloc_id,
-            cx.data_layout().signed_offset(self.offset, i)?,
+            Size::from_bytes(cx.data_layout().signed_offset(self.offset.bytes(), i)?),
         ))
     }
 
-    pub fn overflowing_offset<C: HasDataLayout>(self, i: u64, cx: C) -> (Self, bool) {
-        let (res, over) = cx.data_layout().overflowing_offset(self.offset, i);
-        (MemoryPointer::new(self.alloc_id, res), over)
+    pub fn overflowing_offset<C: HasDataLayout>(self, i: Size, cx: C) -> (Self, bool) {
+        let (res, over) = cx.data_layout().overflowing_offset(self.offset.bytes(), i.bytes());
+        (MemoryPointer::new(self.alloc_id, Size::from_bytes(res)), over)
     }
 
-    pub fn offset<C: HasDataLayout>(self, i: u64, cx: C) -> EvalResult<'tcx, Self> {
+    pub fn offset<C: HasDataLayout>(self, i: Size, cx: C) -> EvalResult<'tcx, Self> {
         Ok(MemoryPointer::new(
             self.alloc_id,
-            cx.data_layout().offset(self.offset, i)?,
+            Size::from_bytes(cx.data_layout().offset(self.offset.bytes(), i.bytes())?),
         ))
     }
 }
@@ -244,7 +244,7 @@ pub struct Allocation {
     pub bytes: Vec<u8>,
     /// Maps from byte addresses to allocations.
     /// Only the first byte of a pointer is inserted into the map.
-    pub relocations: BTreeMap<u64, AllocId>,
+    pub relocations: BTreeMap<Size, AllocId>,
     /// Denotes undefined memory. Reading from undefined memory is forbidden in miri
     pub undef_mask: UndefMask,
     /// The alignment of the allocation to detect unaligned reads.
@@ -257,8 +257,8 @@ pub struct Allocation {
 
 impl Allocation {
     pub fn from_bytes(slice: &[u8], align: Align) -> Self {
-        let mut undef_mask = UndefMask::new(0);
-        undef_mask.grow(slice.len() as u64, true);
+        let mut undef_mask = UndefMask::new(Size::from_bytes(0));
+        undef_mask.grow(Size::from_bytes(slice.len() as u64), true);
         Self {
             bytes: slice.to_owned(),
             relocations: BTreeMap::new(),
@@ -272,10 +272,10 @@ impl Allocation {
         Allocation::from_bytes(slice, Align::from_bytes(1, 1).unwrap())
     }
 
-    pub fn undef(size: u64, align: Align) -> Self {
-        assert_eq!(size as usize as u64, size);
+    pub fn undef(size: Size, align: Align) -> Self {
+        assert_eq!(size.bytes() as usize as u64, size.bytes());
         Allocation {
-            bytes: vec![0; size as usize],
+            bytes: vec![0; size.bytes() as usize],
             relocations: BTreeMap::new(),
             undef_mask: UndefMask::new(size),
             align,
@@ -331,54 +331,54 @@ const BLOCK_SIZE: u64 = 64;
 #[derive(Clone, Debug, Eq, PartialEq, Hash, RustcEncodable, RustcDecodable)]
 pub struct UndefMask {
     blocks: Vec<Block>,
-    len: u64,
+    len: Size,
 }
 
 impl_stable_hash_for!(struct mir::interpret::UndefMask{blocks, len});
 
 impl UndefMask {
-    pub fn new(size: u64) -> Self {
+    pub fn new(size: Size) -> Self {
         let mut m = UndefMask {
             blocks: vec![],
-            len: 0,
+            len: Size::from_bytes(0),
         };
         m.grow(size, false);
         m
     }
 
     /// Check whether the range `start..end` (end-exclusive) is entirely defined.
-    pub fn is_range_defined(&self, start: u64, end: u64) -> bool {
+    pub fn is_range_defined(&self, start: Size, end: Size) -> bool {
         if end > self.len {
             return false;
         }
-        for i in start..end {
-            if !self.get(i) {
+        for i in start.bytes()..end.bytes() {
+            if !self.get(Size::from_bytes(i)) {
                 return false;
             }
         }
         true
     }
 
-    pub fn set_range(&mut self, start: u64, end: u64, new_state: bool) {
+    pub fn set_range(&mut self, start: Size, end: Size, new_state: bool) {
         let len = self.len;
         if end > len {
             self.grow(end - len, new_state);
         }
         self.set_range_inbounds(start, end, new_state);
     }
 
-    pub fn set_range_inbounds(&mut self, start: u64, end: u64, new_state: bool) {
-        for i in start..end {
-            self.set(i, new_state);
+    pub fn set_range_inbounds(&mut self, start: Size, end: Size, new_state: bool) {
+        for i in start.bytes()..end.bytes() {
+            self.set(Size::from_bytes(i), new_state);
         }
     }
 
-    pub fn get(&self, i: u64) -> bool {
+    pub fn get(&self, i: Size) -> bool {
         let (block, bit) = bit_index(i);
         (self.blocks[block] & 1 << bit) != 0
     }
 
-    pub fn set(&mut self, i: u64, new_state: bool) {
+    pub fn set(&mut self, i: Size, new_state: bool) {
         let (block, bit) = bit_index(i);
         if new_state {
             self.blocks[block] |= 1 << bit;
@@ -387,10 +387,10 @@ impl UndefMask {
         }
     }
 
-    pub fn grow(&mut self, amount: u64, new_state: bool) {
-        let unused_trailing_bits = self.blocks.len() as u64 * BLOCK_SIZE - self.len;
-        if amount > unused_trailing_bits {
-            let additional_blocks = amount / BLOCK_SIZE + 1;
+    pub fn grow(&mut self, amount: Size, new_state: bool) {
+        let unused_trailing_bits = self.blocks.len() as u64 * BLOCK_SIZE - self.len.bytes();
+        if amount.bytes() > unused_trailing_bits {
+            let additional_blocks = amount.bytes() / BLOCK_SIZE + 1;
             assert_eq!(additional_blocks as usize as u64, additional_blocks);
             self.blocks.extend(
                 iter::repeat(0).take(additional_blocks as usize),
@@ -402,7 +402,8 @@ impl UndefMask {
     }
 }
 
-fn bit_index(bits: u64) -> (usize, usize) {
+fn bit_index(bits: Size) -> (usize, usize) {
+    let bits = bits.bytes();
     let a = bits / BLOCK_SIZE;
     let b = bits % BLOCK_SIZE;
     assert_eq!(a as usize as u64, a);

src/librustc/mir/interpret/value.rs

@@ -1,6 +1,6 @@
 #![allow(unknown_lints)]
 
-use ty::layout::{Align, HasDataLayout};
+use ty::layout::{Align, HasDataLayout, Size};
 use ty;
 
 use super::{EvalResult, MemoryPointer, PointerArithmetic, Allocation};
@@ -9,12 +9,12 @@ use super::{EvalResult, MemoryPointer, PointerArithmetic, Allocation};
 /// matches Value's optimizations for easy conversions between these two types
 #[derive(Clone, Copy, Debug, Eq, PartialEq, RustcEncodable, RustcDecodable, Hash)]
 pub enum ConstValue<'tcx> {
-    // Used only for types with layout::abi::Scalar ABI and ZSTs which use PrimVal::Undef
+    /// Used only for types with layout::abi::Scalar ABI and ZSTs which use PrimVal::Undef
     ByVal(PrimVal),
-    // Used only for types with layout::abi::ScalarPair
+    /// Used only for types with layout::abi::ScalarPair
     ByValPair(PrimVal, PrimVal),
-    // Used only for the remaining cases
-    ByRef(&'tcx Allocation),
+    /// Used only for the remaining cases. An allocation + offset into the allocation
+    ByRef(&'tcx Allocation, Size),
 }
 
 impl<'tcx> ConstValue<'tcx> {
@@ -129,13 +129,13 @@ impl<'tcx> Pointer {
         }
     }
 
-    pub fn offset<C: HasDataLayout>(self, i: u64, cx: C) -> EvalResult<'tcx, Self> {
+    pub fn offset<C: HasDataLayout>(self, i: Size, cx: C) -> EvalResult<'tcx, Self> {
         let layout = cx.data_layout();
         match self.primval {
             PrimVal::Bytes(b) => {
                 assert_eq!(b as u64 as u128, b);
                 Ok(Pointer::from(
-                    PrimVal::Bytes(layout.offset(b as u64, i)? as u128),
+                    PrimVal::Bytes(layout.offset(b as u64, i.bytes())? as u128),
                 ))
             }
             PrimVal::Ptr(ptr) => ptr.offset(i, layout).map(Pointer::from),
@@ -336,25 +336,25 @@ impl PrimValKind {
         }
     }
 
-    pub fn from_uint_size(size: u64) -> Self {
-        match size {
+    pub fn from_uint_size(size: Size) -> Self {
+        match size.bytes() {
             1 => PrimValKind::U8,
             2 => PrimValKind::U16,
             4 => PrimValKind::U32,
             8 => PrimValKind::U64,
             16 => PrimValKind::U128,
-            _ => bug!("can't make uint with size {}", size),
+            _ => bug!("can't make uint with size {}", size.bytes()),
         }
     }
 
-    pub fn from_int_size(size: u64) -> Self {
-        match size {
+    pub fn from_int_size(size: Size) -> Self {
+        match size.bytes() {
             1 => PrimValKind::I8,
             2 => PrimValKind::I16,
             4 => PrimValKind::I32,
             8 => PrimValKind::I64,
             16 => PrimValKind::I128,
-            _ => bug!("can't make int with size {}", size),
+            _ => bug!("can't make int with size {}", size.bytes()),
         }
     }
 

src/librustc/mir/mod.rs

@@ -1913,7 +1913,7 @@ pub fn print_miri_value<W: Write>(value: Value, ty: Ty, f: &mut W) -> fmt::Resul
                     .get_alloc(ptr.alloc_id);
                 if let Some(alloc) = alloc {
                     assert_eq!(len as usize as u128, len);
-                    let slice = &alloc.bytes[(ptr.offset as usize)..][..(len as usize)];
+                    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)

src/librustc/ty/sty.rs

@@ -19,7 +19,7 @@ use ty::subst::{Substs, Subst, Kind, UnpackedKind};
 use ty::{self, AdtDef, TypeFlags, Ty, TyCtxt, TypeFoldable};
 use ty::{Slice, TyS};
 use util::captures::Captures;
-use mir::interpret::{Allocation, PrimVal, MemoryPointer, Value, ConstValue};
+use mir::interpret::{PrimVal, MemoryPointer, Value, ConstValue};
 
 use std::iter;
 use std::cmp::Ordering;
@@ -1767,15 +1767,6 @@ impl<'tcx> Const<'tcx> {
         Self::from_const_val(tcx, ConstVal::Value(val), ty)
     }
 
-    #[inline]
-    pub fn from_alloc(
-        tcx: TyCtxt<'_, '_, 'tcx>,
-        alloc: &'tcx Allocation,
-        ty: Ty<'tcx>,
-    ) -> &'tcx Self {
-        Self::from_const_value(tcx, ConstValue::ByRef(alloc), ty)
-    }
-
     #[inline]
     pub fn from_byval_value(
         tcx: TyCtxt<'_, '_, 'tcx>,