mikros/rust
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

promoteds in statics may refer to statics

Browse Source
This commit is contained in:
Ralf Jung 2020-12-20 19:34:29 +01:00
parent 06ca7b700c
commit 97cae9c555
2 changed files with 18 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
compiler/rustc_mir/src/const_eval/eval_queries.rs
View File

@ -387,8 +387,12 @@ pub fn eval_to_allocation_raw_provider<'tcx>(
let mut inner = false;
while let Some((mplace, path)) = ref_tracking.todo.pop() {
let mode = match tcx.static_mutability(cid.instance.def_id()) {
Some(_) if cid.promoted.is_none() => CtfeValidationMode::Regular, // a `static`
_ => CtfeValidationMode::Const { inner },
Some(_) if cid.promoted.is_some() => {
// Promoteds in statics are allowed to point to statics.
CtfeValidationMode::Const { inner, allow_static_ptrs: true }
}
Some(_) => CtfeValidationMode::Regular, // a `static`
None => CtfeValidationMode::Const { inner, allow_static_ptrs: false },
};
ecx.const_validate_operand(mplace.into(), path, &mut ref_tracking, mode)?;
inner = true;

20
compiler/rustc_mir/src/interpret/validity.rs
View File

@ -117,11 +117,12 @@ pub enum PathElem {
pub enum CtfeValidationMode {
/// Regular validation, nothing special happening.
Regular,
/// Validation of a `const`. `inner` says if this is an inner, indirect allocation (as opposed
/// to the top-level const allocation).
/// Being an inner allocation makes a difference because the top-level allocation of a `const`
/// is copied for each use, but the inner allocations are implicitly shared.
Const { inner: bool },
/// Validation of a `const`.
/// `inner` says if this is an inner, indirect allocation (as opposed to the top-level const
/// allocation). Being an inner allocation makes a difference because the top-level allocation
/// of a `const` is copied for each use, but the inner allocations are implicitly shared.
/// `allow_static_ptrs` says if pointers to statics are permitted (which is the case for promoteds in statics).
Const { inner: bool, allow_static_ptrs: bool },
}
/// State for tracking recursive validation of references
@ -437,7 +438,10 @@ fn check_safe_pointer(
if let Some(GlobalAlloc::Static(did)) = alloc_kind {
assert!(!self.ecx.tcx.is_thread_local_static(did));
assert!(self.ecx.tcx.is_static(did));
if matches!(self.ctfe_mode, Some(CtfeValidationMode::Const { .. })) {
if matches!(
self.ctfe_mode,
Some(CtfeValidationMode::Const { allow_static_ptrs: false, .. })
) {
// See const_eval::machine::MemoryExtra::can_access_statics for why
// this check is so important.
// This check is reachable when the const just referenced the static,
@ -742,9 +746,9 @@ fn visit_value(&mut self, op: OpTy<'tcx, M::PointerTag>) -> InterpResult<'tcx> {
// Sanity check: `builtin_deref` does not know any pointers that are not primitive.
assert!(op.layout.ty.builtin_deref(true).is_none());
// Special check preventing `UnsafeCell` in constants
// Special check preventing `UnsafeCell` in the inner part of constants
if let Some(def) = op.layout.ty.ty_adt_def() {
if matches!(self.ctfe_mode, Some(CtfeValidationMode::Const { inner: true }))
if matches!(self.ctfe_mode, Some(CtfeValidationMode::Const { inner: true, .. }))
&& Some(def.did) == self.ecx.tcx.lang_items().unsafe_cell_type()
{
throw_validation_failure!(self.path, { "`UnsafeCell` in a `const`" });