diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/tools/miri/src/intptrcast.rs | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/src/tools/miri/src/intptrcast.rs b/src/tools/miri/src/intptrcast.rs index 9e813d58395..ab6a256f714 100644 --- a/src/tools/miri/src/intptrcast.rs +++ b/src/tools/miri/src/intptrcast.rs @@ -275,9 +275,13 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> { impl GlobalStateInner { pub fn free_alloc_id(&mut self, dead_id: AllocId) { - // We can *not* remove this from `base_addr`, since `addr_from_alloc_id` is called on each - // attempt at a memory access to determine the allocation ID and offset -- and there can - // still be pointers with `dead_id` that one can attempt to use for a memory access. + // We can *not* remove this from `base_addr`, since the interpreter design requires that we + // be able to retrieve an AllocId + offset for any memory access *before* we check if the + // access is valid. Specifically, `ptr_get_alloc` is called on each attempt at a memory + // access to determine the allocation ID and offset -- and there can still be pointers with + // `dead_id` that one can attempt to use for a memory access. `ptr_get_alloc` may return + // `None` only if the pointer truly has no provenance (this ensures consistent error + // messages). // However, we *can* remove it from `int_to_ptr_map`, since any wildcard pointers that exist // can no longer actually be accessing that address. This ensures `alloc_id_from_addr` never // returns a dead allocation. |