2018-10-19 02:51:04 -05:00
|
|
|
use std::mem;
|
2018-05-01 11:13:22 -05:00
|
|
|
|
2018-11-06 10:46:54 -06:00
|
|
|
use rustc::ty::{self, layout};
|
2018-10-19 02:51:04 -05:00
|
|
|
use rustc::hir::def_id::{DefId, CRATE_DEF_INDEX};
|
|
|
|
|
2018-11-01 02:56:41 -05:00
|
|
|
use crate::*;
|
2018-10-19 02:51:04 -05:00
|
|
|
|
2018-12-11 07:16:58 -06:00
|
|
|
impl<'a, 'mir, 'tcx> EvalContextExt<'a, 'mir, 'tcx> for crate::MiriEvalContext<'a, 'mir, 'tcx> {}
|
2019-02-15 19:29:38 -06:00
|
|
|
|
|
|
|
pub trait EvalContextExt<'a, 'mir, 'tcx: 'a + 'mir>: crate::MiriEvalContextExt<'a, 'mir, 'tcx> {
|
|
|
|
/// Gets an instance for a path.
|
2018-10-19 02:51:04 -05:00
|
|
|
fn resolve_path(&self, path: &[&str]) -> EvalResult<'tcx, ty::Instance<'tcx>> {
|
2018-12-11 07:16:58 -06:00
|
|
|
let this = self.eval_context_ref();
|
|
|
|
this.tcx
|
2018-10-19 02:51:04 -05:00
|
|
|
.crates()
|
|
|
|
.iter()
|
2018-12-11 07:16:58 -06:00
|
|
|
.find(|&&krate| this.tcx.original_crate_name(krate) == path[0])
|
2018-10-19 02:51:04 -05:00
|
|
|
.and_then(|krate| {
|
|
|
|
let krate = DefId {
|
|
|
|
krate: *krate,
|
|
|
|
index: CRATE_DEF_INDEX,
|
|
|
|
};
|
2018-12-11 07:16:58 -06:00
|
|
|
let mut items = this.tcx.item_children(krate);
|
2018-10-19 02:51:04 -05:00
|
|
|
let mut path_it = path.iter().skip(1).peekable();
|
|
|
|
|
|
|
|
while let Some(segment) = path_it.next() {
|
|
|
|
for item in mem::replace(&mut items, Default::default()).iter() {
|
|
|
|
if item.ident.name == *segment {
|
|
|
|
if path_it.peek().is_none() {
|
2018-12-11 07:16:58 -06:00
|
|
|
return Some(ty::Instance::mono(this.tcx.tcx, item.def.def_id()));
|
2018-10-19 02:51:04 -05:00
|
|
|
}
|
|
|
|
|
2018-12-11 07:16:58 -06:00
|
|
|
items = this.tcx.item_children(item.def.def_id());
|
2018-10-19 02:51:04 -05:00
|
|
|
break;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
None
|
|
|
|
})
|
|
|
|
.ok_or_else(|| {
|
|
|
|
let path = path.iter().map(|&s| s.to_owned()).collect();
|
2019-04-03 03:48:11 -05:00
|
|
|
InterpError::PathNotFound(path).into()
|
2018-10-19 02:51:04 -05:00
|
|
|
})
|
|
|
|
}
|
2018-11-05 09:05:17 -06:00
|
|
|
|
2019-02-15 19:29:38 -06:00
|
|
|
/// Visits the memory covered by `place`, sensitive to freezing: the 3rd parameter
|
2018-12-11 07:16:58 -06:00
|
|
|
/// will be true if this is frozen, false if this is in an `UnsafeCell`.
|
2018-11-07 09:56:25 -06:00
|
|
|
fn visit_freeze_sensitive(
|
2018-11-05 09:05:17 -06:00
|
|
|
&self,
|
|
|
|
place: MPlaceTy<'tcx, Borrow>,
|
|
|
|
size: Size,
|
2018-11-07 09:56:25 -06:00
|
|
|
mut action: impl FnMut(Pointer<Borrow>, Size, bool) -> EvalResult<'tcx>,
|
2018-11-05 09:05:17 -06:00
|
|
|
) -> EvalResult<'tcx> {
|
2018-12-11 07:16:58 -06:00
|
|
|
let this = self.eval_context_ref();
|
2018-11-05 09:05:17 -06:00
|
|
|
trace!("visit_frozen(place={:?}, size={:?})", *place, size);
|
|
|
|
debug_assert_eq!(size,
|
2018-12-11 07:16:58 -06:00
|
|
|
this.size_and_align_of_mplace(place)?
|
2018-11-05 09:05:17 -06:00
|
|
|
.map(|(size, _)| size)
|
|
|
|
.unwrap_or_else(|| place.layout.size)
|
|
|
|
);
|
2019-02-15 19:29:38 -06:00
|
|
|
// Store how far we proceeded into the place so far. Everything to the left of
|
2018-11-05 09:05:17 -06:00
|
|
|
// this offset has already been handled, in the sense that the frozen parts
|
|
|
|
// have had `action` called on them.
|
|
|
|
let mut end_ptr = place.ptr;
|
|
|
|
// Called when we detected an `UnsafeCell` at the given offset and size.
|
|
|
|
// Calls `action` and advances `end_ptr`.
|
2018-11-07 09:56:25 -06:00
|
|
|
let mut unsafe_cell_action = |unsafe_cell_ptr: Scalar<Borrow>, unsafe_cell_size: Size| {
|
|
|
|
if unsafe_cell_size != Size::ZERO {
|
|
|
|
debug_assert_eq!(unsafe_cell_ptr.to_ptr().unwrap().alloc_id,
|
|
|
|
end_ptr.to_ptr().unwrap().alloc_id);
|
|
|
|
debug_assert_eq!(unsafe_cell_ptr.to_ptr().unwrap().tag,
|
|
|
|
end_ptr.to_ptr().unwrap().tag);
|
|
|
|
}
|
2018-11-05 09:05:17 -06:00
|
|
|
// We assume that we are given the fields in increasing offset order,
|
|
|
|
// and nothing else changes.
|
2018-12-11 07:16:58 -06:00
|
|
|
let unsafe_cell_offset = unsafe_cell_ptr.get_ptr_offset(this);
|
|
|
|
let end_offset = end_ptr.get_ptr_offset(this);
|
2018-11-05 09:05:17 -06:00
|
|
|
assert!(unsafe_cell_offset >= end_offset);
|
|
|
|
let frozen_size = unsafe_cell_offset - end_offset;
|
|
|
|
// Everything between the end_ptr and this `UnsafeCell` is frozen.
|
|
|
|
if frozen_size != Size::ZERO {
|
2018-11-07 09:56:25 -06:00
|
|
|
action(end_ptr.to_ptr()?, frozen_size, /*frozen*/true)?;
|
|
|
|
}
|
|
|
|
// This `UnsafeCell` is NOT frozen.
|
|
|
|
if unsafe_cell_size != Size::ZERO {
|
|
|
|
action(unsafe_cell_ptr.to_ptr()?, unsafe_cell_size, /*frozen*/false)?;
|
2018-11-05 09:05:17 -06:00
|
|
|
}
|
|
|
|
// Update end end_ptr.
|
2018-12-11 07:16:58 -06:00
|
|
|
end_ptr = unsafe_cell_ptr.ptr_wrapping_offset(unsafe_cell_size, this);
|
2018-11-05 09:05:17 -06:00
|
|
|
// Done
|
|
|
|
Ok(())
|
|
|
|
};
|
|
|
|
// Run a visitor
|
|
|
|
{
|
|
|
|
let mut visitor = UnsafeCellVisitor {
|
2018-12-11 07:16:58 -06:00
|
|
|
ecx: this,
|
2018-11-05 09:05:17 -06:00
|
|
|
unsafe_cell_action: |place| {
|
|
|
|
trace!("unsafe_cell_action on {:?}", place.ptr);
|
|
|
|
// We need a size to go on.
|
2018-12-11 07:16:58 -06:00
|
|
|
let unsafe_cell_size = this.size_and_align_of_mplace(place)?
|
2018-11-23 02:46:51 -06:00
|
|
|
.map(|(size, _)| size)
|
2018-11-05 09:05:17 -06:00
|
|
|
// for extern types, just cover what we can
|
2018-11-23 02:46:51 -06:00
|
|
|
.unwrap_or_else(|| place.layout.size);
|
2018-11-06 10:46:54 -06:00
|
|
|
// Now handle this `UnsafeCell`, unless it is empty.
|
|
|
|
if unsafe_cell_size != Size::ZERO {
|
2018-11-07 09:56:25 -06:00
|
|
|
unsafe_cell_action(place.ptr, unsafe_cell_size)
|
2018-11-06 10:46:54 -06:00
|
|
|
} else {
|
|
|
|
Ok(())
|
|
|
|
}
|
2018-11-05 09:05:17 -06:00
|
|
|
},
|
|
|
|
};
|
|
|
|
visitor.visit_value(place)?;
|
|
|
|
}
|
|
|
|
// The part between the end_ptr and the end of the place is also frozen.
|
|
|
|
// So pretend there is a 0-sized `UnsafeCell` at the end.
|
2018-12-11 07:16:58 -06:00
|
|
|
unsafe_cell_action(place.ptr.ptr_wrapping_offset(size, this), Size::ZERO)?;
|
2018-11-05 09:05:17 -06:00
|
|
|
// Done!
|
|
|
|
return Ok(());
|
|
|
|
|
|
|
|
/// Visiting the memory covered by a `MemPlace`, being aware of
|
|
|
|
/// whether we are inside an `UnsafeCell` or not.
|
|
|
|
struct UnsafeCellVisitor<'ecx, 'a, 'mir, 'tcx, F>
|
|
|
|
where F: FnMut(MPlaceTy<'tcx, Borrow>) -> EvalResult<'tcx>
|
|
|
|
{
|
|
|
|
ecx: &'ecx MiriEvalContext<'a, 'mir, 'tcx>,
|
|
|
|
unsafe_cell_action: F,
|
|
|
|
}
|
|
|
|
|
2018-11-13 05:48:20 -06:00
|
|
|
impl<'ecx, 'a, 'mir, 'tcx, F>
|
|
|
|
ValueVisitor<'a, 'mir, 'tcx, Evaluator<'tcx>>
|
|
|
|
for
|
|
|
|
UnsafeCellVisitor<'ecx, 'a, 'mir, 'tcx, F>
|
2018-11-05 09:05:17 -06:00
|
|
|
where
|
|
|
|
F: FnMut(MPlaceTy<'tcx, Borrow>) -> EvalResult<'tcx>
|
|
|
|
{
|
|
|
|
type V = MPlaceTy<'tcx, Borrow>;
|
|
|
|
|
|
|
|
#[inline(always)]
|
|
|
|
fn ecx(&self) -> &MiriEvalContext<'a, 'mir, 'tcx> {
|
|
|
|
&self.ecx
|
|
|
|
}
|
|
|
|
|
2019-02-15 19:29:38 -06:00
|
|
|
// Hook to detect `UnsafeCell`.
|
2018-11-05 09:05:17 -06:00
|
|
|
fn visit_value(&mut self, v: MPlaceTy<'tcx, Borrow>) -> EvalResult<'tcx>
|
|
|
|
{
|
|
|
|
trace!("UnsafeCellVisitor: {:?} {:?}", *v, v.layout.ty);
|
|
|
|
let is_unsafe_cell = match v.layout.ty.sty {
|
|
|
|
ty::Adt(adt, _) => Some(adt.did) == self.ecx.tcx.lang_items().unsafe_cell_type(),
|
|
|
|
_ => false,
|
|
|
|
};
|
|
|
|
if is_unsafe_cell {
|
|
|
|
// We do not have to recurse further, this is an `UnsafeCell`.
|
|
|
|
(self.unsafe_cell_action)(v)
|
|
|
|
} else if self.ecx.type_is_freeze(v.layout.ty) {
|
|
|
|
// This is `Freeze`, there cannot be an `UnsafeCell`
|
|
|
|
Ok(())
|
|
|
|
} else {
|
|
|
|
// Proceed further
|
|
|
|
self.walk_value(v)
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2019-02-15 19:29:38 -06:00
|
|
|
// Make sure we visit aggregrates in increasing offset order.
|
2018-11-06 10:46:54 -06:00
|
|
|
fn visit_aggregate(
|
|
|
|
&mut self,
|
|
|
|
place: MPlaceTy<'tcx, Borrow>,
|
|
|
|
fields: impl Iterator<Item=EvalResult<'tcx, MPlaceTy<'tcx, Borrow>>>,
|
|
|
|
) -> EvalResult<'tcx> {
|
|
|
|
match place.layout.fields {
|
|
|
|
layout::FieldPlacement::Array { .. } => {
|
|
|
|
// For the array layout, we know the iterator will yield sorted elements so
|
|
|
|
// we can avoid the allocation.
|
|
|
|
self.walk_aggregate(place, fields)
|
|
|
|
}
|
|
|
|
layout::FieldPlacement::Arbitrary { .. } => {
|
|
|
|
// Gather the subplaces and sort them before visiting.
|
|
|
|
let mut places = fields.collect::<EvalResult<'tcx, Vec<MPlaceTy<'tcx, Borrow>>>>()?;
|
2019-02-27 04:38:43 -06:00
|
|
|
places.sort_by_key(|place| place.ptr.get_ptr_offset(self.ecx()));
|
2018-11-06 10:46:54 -06:00
|
|
|
self.walk_aggregate(place, places.into_iter().map(Ok))
|
|
|
|
}
|
|
|
|
layout::FieldPlacement::Union { .. } => {
|
|
|
|
// Uh, what?
|
2019-02-15 19:29:38 -06:00
|
|
|
bug!("a union is not an aggregate we should ever visit")
|
2018-11-06 10:46:54 -06:00
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2019-02-15 19:29:38 -06:00
|
|
|
// We have to do *something* for unions.
|
2018-11-05 09:05:17 -06:00
|
|
|
fn visit_union(&mut self, v: MPlaceTy<'tcx, Borrow>) -> EvalResult<'tcx>
|
|
|
|
{
|
|
|
|
// With unions, we fall back to whatever the type says, to hopefully be consistent
|
|
|
|
// with LLVM IR.
|
2019-02-15 19:29:38 -06:00
|
|
|
// FIXME: are we consistent, and is this really the behavior we want?
|
2018-11-05 09:05:17 -06:00
|
|
|
let frozen = self.ecx.type_is_freeze(v.layout.ty);
|
|
|
|
if frozen {
|
|
|
|
Ok(())
|
|
|
|
} else {
|
|
|
|
(self.unsafe_cell_action)(v)
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2019-02-15 19:29:38 -06:00
|
|
|
// We should never get to a primitive, but always short-circuit somewhere above.
|
2018-11-13 05:48:20 -06:00
|
|
|
fn visit_primitive(&mut self, _v: MPlaceTy<'tcx, Borrow>) -> EvalResult<'tcx>
|
2018-11-05 09:05:17 -06:00
|
|
|
{
|
2019-02-15 19:29:38 -06:00
|
|
|
bug!("we should always short-circuit before coming to a primitive")
|
2018-11-05 09:05:17 -06:00
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
2018-10-19 02:51:04 -05:00
|
|
|
}
|