nordic-dev.net/rust
nordic-dev.net/rust
2
0
Fork 0
mirror of https://github.com/rust-lang/rust.git synced 2024-11-27 01:04:03 +00:00
Code Issues Packages Projects Releases Wiki Activity

Auto merge of #95707 - RalfJung:initialized, r=oli-obk

Browse Source 
interp/validity: enforce Scalar::Initialized

This is a follow-up to https://github.com/rust-lang/rust/pull/94527, to also account for the new kind of `Scalar` layout inside the validity checker.

r? `@oli-obk`
This commit is contained in:
bors 2022-04-06 14:07:27 +00:00
commit b6ab1fae73
1 changed files with 22 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
compiler/rustc_const_eval/src/interpret/validity.rs
View File

@ -629,11 +629,24 @@ impl<'rt, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValidityVisitor<'rt, 'mir, '
op: &OpTy<'tcx, M::PointerTag>,
scalar_layout: ScalarAbi,
) -> InterpResult<'tcx> {
if scalar_layout.valid_range(self.ecx).is_full_for(op.layout.size) {
// We check `is_full_range` in a slightly complicated way because *if* we are checking
// number validity, then we want to ensure that `Scalar::Initialized` is indeed initialized,
// i.e. that we go over the `check_init` below.
let is_full_range = match scalar_layout {
ScalarAbi::Initialized { valid_range, .. } => {
if M::enforce_number_validity(self.ecx) {
false // not "full" since uninit is not accepted
} else {
valid_range.is_full_for(op.layout.size)
}
}
ScalarAbi::Union { .. } => true,
};
if is_full_range {
// Nothing to check
return Ok(());
}
// At least one value is excluded.
// We have something to check.
let valid_range = scalar_layout.valid_range(self.ecx);
let WrappingRange { start, end } = valid_range;
let max_value = op.layout.size.unsigned_int_max();
@ -647,9 +660,11 @@ impl<'rt, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValidityVisitor<'rt, 'mir, '
expected { "something {}", wrapping_range_format(valid_range, max_value) },
);
let bits = match value.try_to_int() {
Ok(int) => int.assert_bits(op.layout.size),
Err(_) => {
// So this is a pointer then, and casting to an int failed.
// Can only happen during CTFE.
// We support 2 kinds of ranges here: full range, and excluding zero.
if start == 1 && end == max_value {
// Only null is the niche. So make sure the ptr is NOT null.
if self.ecx.scalar_may_be_null(value) {
@ -660,7 +675,11 @@ impl<'rt, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValidityVisitor<'rt, 'mir, '
wrapping_range_format(valid_range, max_value)
}
)
} else {
return Ok(());
}
} else if scalar_layout.valid_range(self.ecx).is_full_for(op.layout.size) {
// Easy. (This is reachable if `enforce_number_validity` is set.)
return Ok(());
} else {
// Conservatively, we reject, because the pointer *could* have a bad
@ -674,9 +693,8 @@ impl<'rt, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValidityVisitor<'rt, 'mir, '
)
}
}
Ok(int) => int.assert_bits(op.layout.size),
};
// Now compare. This is slightly subtle because this is a special "wrap-around" range.
// Now compare.
if valid_range.contains(bits) {
Ok(())
} else {