Skip to content
Permalink
Browse files

Miri: refactor new allocation tagging

  • Loading branch information...
RalfJung committed Apr 15, 2019
1 parent ee621f4 commit 19485cc10173cb72e24813ce95b65c8f3cf92326
@@ -45,12 +45,10 @@ pub struct Allocation<Tag=(),Extra=()> {
}


pub trait AllocationExtra<Tag, MemoryExtra>: ::std::fmt::Debug + Clone {
/// Hook to initialize the extra data when an allocation gets created.
fn memory_allocated(
_size: Size,
_memory_extra: &MemoryExtra
) -> Self;
pub trait AllocationExtra<Tag>: ::std::fmt::Debug + Clone {
// There is no constructor in here because the constructor's type depends
// on `MemoryKind`, and making things sufficiently generic leads to painful
// inference failure.

/// Hook for performing extra checks on a memory read access.
///
@@ -88,15 +86,8 @@ pub trait AllocationExtra<Tag, MemoryExtra>: ::std::fmt::Debug + Clone {
}
}

impl AllocationExtra<(), ()> for () {
#[inline(always)]
fn memory_allocated(
_size: Size,
_memory_extra: &()
) -> Self {
()
}
}
// For Tag=() and no extra state, we have is a trivial implementation.
impl AllocationExtra<()> for () { }

impl<Tag, Extra> Allocation<Tag, Extra> {
/// Creates a read-only allocation initialized by the given bytes
@@ -159,23 +150,21 @@ impl<'tcx, Tag, Extra> Allocation<Tag, Extra> {
}

/// Byte accessors
impl<'tcx, Tag: Copy, Extra> Allocation<Tag, Extra> {
impl<'tcx, Tag: Copy, Extra: AllocationExtra<Tag>> Allocation<Tag, Extra> {
/// The last argument controls whether we error out when there are undefined
/// or pointer bytes. You should never call this, call `get_bytes` or
/// `get_bytes_with_undef_and_ptr` instead,
///
/// This function also guarantees that the resulting pointer will remain stable
/// even when new allocations are pushed to the `HashMap`. `copy_repeatedly` relies
/// on that.
fn get_bytes_internal<MemoryExtra>(
fn get_bytes_internal(
&self,
cx: &impl HasDataLayout,
ptr: Pointer<Tag>,
size: Size,
check_defined_and_ptr: bool,
) -> EvalResult<'tcx, &[u8]>
// FIXME: Working around https://github.com/rust-lang/rust/issues/56209
where Extra: AllocationExtra<Tag, MemoryExtra>
{
self.check_bounds(cx, ptr, size)?;

@@ -196,43 +185,37 @@ impl<'tcx, Tag: Copy, Extra> Allocation<Tag, Extra> {
}

#[inline]
pub fn get_bytes<MemoryExtra>(
pub fn get_bytes(
&self,
cx: &impl HasDataLayout,
ptr: Pointer<Tag>,
size: Size,
) -> EvalResult<'tcx, &[u8]>
// FIXME: Working around https://github.com/rust-lang/rust/issues/56209
where Extra: AllocationExtra<Tag, MemoryExtra>
{
self.get_bytes_internal(cx, ptr, size, true)
}

/// It is the caller's responsibility to handle undefined and pointer bytes.
/// However, this still checks that there are no relocations on the *edges*.
#[inline]
pub fn get_bytes_with_undef_and_ptr<MemoryExtra>(
pub fn get_bytes_with_undef_and_ptr(
&self,
cx: &impl HasDataLayout,
ptr: Pointer<Tag>,
size: Size,
) -> EvalResult<'tcx, &[u8]>
// FIXME: Working around https://github.com/rust-lang/rust/issues/56209
where Extra: AllocationExtra<Tag, MemoryExtra>
{
self.get_bytes_internal(cx, ptr, size, false)
}

/// Just calling this already marks everything as defined and removes relocations,
/// so be sure to actually put data there!
pub fn get_bytes_mut<MemoryExtra>(
pub fn get_bytes_mut(
&mut self,
cx: &impl HasDataLayout,
ptr: Pointer<Tag>,
size: Size,
) -> EvalResult<'tcx, &mut [u8]>
// FIXME: Working around https://github.com/rust-lang/rust/issues/56209
where Extra: AllocationExtra<Tag, MemoryExtra>
{
assert_ne!(size.bytes(), 0, "0-sized accesses should never even get a `Pointer`");
self.check_bounds(cx, ptr, size)?;
@@ -250,16 +233,14 @@ impl<'tcx, Tag: Copy, Extra> Allocation<Tag, Extra> {
}

/// Reading and writing
impl<'tcx, Tag: Copy, Extra> Allocation<Tag, Extra> {
impl<'tcx, Tag: Copy, Extra: AllocationExtra<Tag>> Allocation<Tag, Extra> {
/// Reads bytes until a `0` is encountered. Will error if the end of the allocation is reached
/// before a `0` is found.
pub fn read_c_str<MemoryExtra>(
pub fn read_c_str(
&self,
cx: &impl HasDataLayout,
ptr: Pointer<Tag>,
) -> EvalResult<'tcx, &[u8]>
// FIXME: Working around https://github.com/rust-lang/rust/issues/56209
where Extra: AllocationExtra<Tag, MemoryExtra>
{
assert_eq!(ptr.offset.bytes() as usize as u64, ptr.offset.bytes());
let offset = ptr.offset.bytes() as usize;
@@ -278,15 +259,13 @@ impl<'tcx, Tag: Copy, Extra> Allocation<Tag, Extra> {
/// Validates that `ptr.offset` and `ptr.offset + size` do not point to the middle of a
/// relocation. If `allow_ptr_and_undef` is `false`, also enforces that the memory in the
/// given range contains neither relocations nor undef bytes.
pub fn check_bytes<MemoryExtra>(
pub fn check_bytes(
&self,
cx: &impl HasDataLayout,
ptr: Pointer<Tag>,
size: Size,
allow_ptr_and_undef: bool,
) -> EvalResult<'tcx>
// FIXME: Working around https://github.com/rust-lang/rust/issues/56209
where Extra: AllocationExtra<Tag, MemoryExtra>
{
// Check bounds and relocations on the edges
self.get_bytes_with_undef_and_ptr(cx, ptr, size)?;
@@ -301,30 +280,26 @@ impl<'tcx, Tag: Copy, Extra> Allocation<Tag, Extra> {
/// Writes `src` to the memory starting at `ptr.offset`.
///
/// Will do bounds checks on the allocation.
pub fn write_bytes<MemoryExtra>(
pub fn write_bytes(
&mut self,
cx: &impl HasDataLayout,
ptr: Pointer<Tag>,
src: &[u8],
) -> EvalResult<'tcx>
// FIXME: Working around https://github.com/rust-lang/rust/issues/56209
where Extra: AllocationExtra<Tag, MemoryExtra>
{
let bytes = self.get_bytes_mut(cx, ptr, Size::from_bytes(src.len() as u64))?;
bytes.clone_from_slice(src);
Ok(())
}

/// Sets `count` bytes starting at `ptr.offset` with `val`. Basically `memset`.
pub fn write_repeat<MemoryExtra>(
pub fn write_repeat(
&mut self,
cx: &impl HasDataLayout,
ptr: Pointer<Tag>,
val: u8,
count: Size
) -> EvalResult<'tcx>
// FIXME: Working around https://github.com/rust-lang/rust/issues/56209
where Extra: AllocationExtra<Tag, MemoryExtra>
{
let bytes = self.get_bytes_mut(cx, ptr, count)?;
for b in bytes {
@@ -341,14 +316,12 @@ impl<'tcx, Tag: Copy, Extra> Allocation<Tag, Extra> {
/// being valid for ZSTs
///
/// Note: This function does not do *any* alignment checks, you need to do these before calling
pub fn read_scalar<MemoryExtra>(
pub fn read_scalar(
&self,
cx: &impl HasDataLayout,
ptr: Pointer<Tag>,
size: Size
) -> EvalResult<'tcx, ScalarMaybeUndef<Tag>>
// FIXME: Working around https://github.com/rust-lang/rust/issues/56209
where Extra: AllocationExtra<Tag, MemoryExtra>
{
// get_bytes_unchecked tests relocation edges
let bytes = self.get_bytes_with_undef_and_ptr(cx, ptr, size)?;
@@ -379,13 +352,11 @@ impl<'tcx, Tag: Copy, Extra> Allocation<Tag, Extra> {
}

/// Note: This function does not do *any* alignment checks, you need to do these before calling
pub fn read_ptr_sized<MemoryExtra>(
pub fn read_ptr_sized(
&self,
cx: &impl HasDataLayout,
ptr: Pointer<Tag>,
) -> EvalResult<'tcx, ScalarMaybeUndef<Tag>>
// FIXME: Working around https://github.com/rust-lang/rust/issues/56209
where Extra: AllocationExtra<Tag, MemoryExtra>
{
self.read_scalar(cx, ptr, cx.data_layout().pointer_size)
}
@@ -398,15 +369,13 @@ impl<'tcx, Tag: Copy, Extra> Allocation<Tag, Extra> {
/// being valid for ZSTs
///
/// Note: This function does not do *any* alignment checks, you need to do these before calling
pub fn write_scalar<MemoryExtra>(
pub fn write_scalar(
&mut self,
cx: &impl HasDataLayout,
ptr: Pointer<Tag>,
val: ScalarMaybeUndef<Tag>,
type_size: Size,
) -> EvalResult<'tcx>
// FIXME: Working around https://github.com/rust-lang/rust/issues/56209
where Extra: AllocationExtra<Tag, MemoryExtra>
{
let val = match val {
ScalarMaybeUndef::Scalar(scalar) => scalar,
@@ -446,14 +415,12 @@ impl<'tcx, Tag: Copy, Extra> Allocation<Tag, Extra> {
}

/// Note: This function does not do *any* alignment checks, you need to do these before calling
pub fn write_ptr_sized<MemoryExtra>(
pub fn write_ptr_sized(
&mut self,
cx: &impl HasDataLayout,
ptr: Pointer<Tag>,
val: ScalarMaybeUndef<Tag>
) -> EvalResult<'tcx>
// FIXME: Working around https://github.com/rust-lang/rust/issues/56209
where Extra: AllocationExtra<Tag, MemoryExtra>
{
let ptr_size = cx.data_layout().pointer_size;
self.write_scalar(cx, ptr.into(), val, ptr_size)
@@ -94,11 +94,17 @@ impl<'tcx> Pointer<()> {
Pointer { alloc_id, offset, tag: () }
}

#[inline(always)]
pub fn with_tag<Tag>(self, tag: Tag) -> Pointer<Tag>
{
Pointer::new_with_tag(self.alloc_id, self.offset, tag)
}

#[inline(always)]
pub fn with_default_tag<Tag>(self) -> Pointer<Tag>
where Tag: Default
{
Pointer::new_with_tag(self.alloc_id, self.offset, Default::default())
self.with_tag(Tag::default())
}
}

@@ -119,14 +119,19 @@ impl<Tag> fmt::Display for Scalar<Tag> {

impl<'tcx> Scalar<()> {
#[inline]
pub fn with_default_tag<Tag>(self) -> Scalar<Tag>
where Tag: Default
{
pub fn with_tag<Tag>(self, new_tag: Tag) -> Scalar<Tag> {
match self {
Scalar::Ptr(ptr) => Scalar::Ptr(ptr.with_default_tag()),
Scalar::Ptr(ptr) => Scalar::Ptr(ptr.with_tag(new_tag)),
Scalar::Bits { bits, size } => Scalar::Bits { bits, size },
}
}

#[inline(always)]
pub fn with_default_tag<Tag>(self) -> Scalar<Tag>
where Tag: Default
{
self.with_tag(Tag::default())
}
}

impl<'tcx, Tag> Scalar<Tag> {
@@ -138,14 +143,6 @@ impl<'tcx, Tag> Scalar<Tag> {
}
}

#[inline]
pub fn with_tag(self, new_tag: Tag) -> Self {
match self {
Scalar::Ptr(ptr) => Scalar::Ptr(Pointer { tag: new_tag, ..ptr }),
Scalar::Bits { bits, size } => Scalar::Bits { bits, size },
}
}

#[inline]
pub fn ptr_null(cx: &impl HasDataLayout) -> Self {
Scalar::Bits {
@@ -434,14 +431,19 @@ impl<Tag> fmt::Display for ScalarMaybeUndef<Tag> {

impl<'tcx> ScalarMaybeUndef<()> {
#[inline]
pub fn with_default_tag<Tag>(self) -> ScalarMaybeUndef<Tag>
where Tag: Default
{
pub fn with_tag<Tag>(self, new_tag: Tag) -> ScalarMaybeUndef<Tag> {
match self {
ScalarMaybeUndef::Scalar(s) => ScalarMaybeUndef::Scalar(s.with_default_tag()),
ScalarMaybeUndef::Scalar(s) => ScalarMaybeUndef::Scalar(s.with_tag(new_tag)),
ScalarMaybeUndef::Undef => ScalarMaybeUndef::Undef,
}
}

#[inline(always)]
pub fn with_default_tag<Tag>(self) -> ScalarMaybeUndef<Tag>
where Tag: Default
{
self.with_tag(Tag::default())
}
}

impl<'tcx, Tag> ScalarMaybeUndef<Tag> {
@@ -11,7 +11,7 @@ use rustc::hir::def::Def;
use rustc::mir::interpret::{ConstEvalErr, ErrorHandled};
use rustc::mir;
use rustc::ty::{self, TyCtxt, query::TyCtxtAt};
use rustc::ty::layout::{self, LayoutOf, VariantIdx};
use rustc::ty::layout::{self, LayoutOf, VariantIdx, Size};
use rustc::ty::subst::Subst;
use rustc::traits::Reveal;
use rustc::util::common::ErrorReported;
@@ -21,7 +21,7 @@ use syntax::ast::Mutability;
use syntax::source_map::{Span, DUMMY_SP};

use crate::interpret::{self,
PlaceTy, MPlaceTy, MemPlace, OpTy, ImmTy, Immediate, Scalar, Pointer,
PlaceTy, MPlaceTy, MemPlace, OpTy, ImmTy, Immediate, Scalar,
RawConst, ConstValue,
EvalResult, EvalError, InterpError, GlobalId, InterpretCx, StackPopCleanup,
Allocation, AllocId, MemoryKind,
@@ -406,6 +406,15 @@ impl<'a, 'mir, 'tcx> interpret::Machine<'a, 'mir, 'tcx>
Cow::Borrowed(alloc)
}

#[inline(always)]
fn new_allocation(
_size: Size,
_extra: &Self::MemoryExtra,
_kind: MemoryKind<!>,
) -> (Self::AllocExtra, Self::PointerTag) {
((), ())
}

fn box_alloc(
_ecx: &mut InterpretCx<'a, 'mir, 'tcx, Self>,
_dest: PlaceTy<'tcx>,
@@ -439,15 +448,6 @@ impl<'a, 'mir, 'tcx> interpret::Machine<'a, 'mir, 'tcx>
)
}

#[inline(always)]
fn tag_new_allocation(
_ecx: &mut InterpretCx<'a, 'mir, 'tcx, Self>,
ptr: Pointer,
_kind: MemoryKind<Self::MemoryKinds>,
) -> Pointer {
ptr
}

#[inline(always)]
fn stack_push(
_ecx: &mut InterpretCx<'a, 'mir, 'tcx, Self>,
Oops, something went wrong.

0 comments on commit 19485cc

Please sign in to comment.
You can’t perform that action at this time.