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expand comment in memory.rs with extra soundness concerns

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Ralf Jung 2020-04-29 14:56:40 +02:00
parent a03355dea0
commit 07772fcf6f
1 changed files with 3 additions and 1 deletions
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4
src/librustc_mir/interpret/memory.rs
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@ -453,7 +453,9 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Memory<'mir, 'tcx, M> {
// thing here: one maps to `GlobalAlloc::Static`, this is the "lazy" ID,
// and the other one is maps to `GlobalAlloc::Memory`, this is returned by
// `const_eval_raw` and it is the "resolved" ID.
// The resolved ID is never used by the interpreted progrma, it is hidden.
// The resolved ID is never used by the interpreted program, it is hidden.
// This is relied upon for soundness of const-patterns; a pointer to the resolved
// ID would "sidestep" the checks that make sure consts do not point to statics!
// The `GlobalAlloc::Memory` branch here is still reachable though; when a static
// contains a reference to memory that was created during its evaluation (i.e., not
// to another static), those inner references only exist in "resolved" form.