bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Apply suggestions from code review

Browse source 
Co-authored-by: Ralf Jung <post@ralfj.de>
This commit is contained in:
Camille Gillot 2023-10-27 20:51:25 +02:00 • committed by GitHub
parent 856161886a
commit 24be43356e
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
2 changed files with 12 additions and 6 deletions
Download patch file Download diff file Expand all files Collapse all files

11
compiler/rustc_middle/src/mir/consts.rs
View file

@ -174,10 +174,13 @@ impl<'tcx> ConstValue<'tcx> {
}
/// Check if a constant may contain provenance information. This is used by MIR opts.
/// Can return `true` even if there is no provenance.
pub fn may_have_provenance(&self, tcx: TyCtxt<'tcx>, size: Size) -> bool {
match *self {
ConstValue::ZeroSized | ConstValue::Scalar(Scalar::Int(_)) => return false,
ConstValue::Scalar(Scalar::Ptr(..)) => return true,
// It's hard to find out the part of the allocation we point to;
// just conservatively check everything.
ConstValue::Slice { data, meta: _ } => !data.inner().provenance().ptrs().is_empty(),
ConstValue::Indirect { alloc_id, offset } => !tcx
.global_alloc(alloc_id)
@ -504,10 +507,10 @@ impl<'tcx> Const<'tcx> {
/// Return true if any evaluation of this constant always returns the same value,
/// taking into account even pointer identity tests.
pub fn is_deterministic(&self) -> bool {
// Some constants may contain pointers. We need to preserve the provenance of these
// pointers, but not all constants guarantee this:
// - valtrees purposefully do not;
// - ConstValue::Slice does not either.
// Some constants may generate fresh allocations for pointers they contain,
// so using the same constant twice can yield two different results:
// - valtrees purposefully generate new allocations
// - ConstValue::Slice also generate new allocations
match self {
Const::Ty(c) => match c.kind() {
ty::ConstKind::Param(..) => true,