diff --git a/src/eval_context.rs b/src/eval_context.rs index 7ea4003b0f7..dedb8a53b71 100644 --- a/src/eval_context.rs +++ b/src/eval_context.rs @@ -172,7 +172,7 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> { // FIXME: cache these allocs let ptr = self.memory.allocate(s.len() as u64, 1)?; self.memory.write_bytes(ptr, s.as_bytes())?; - self.memory.mark_static(ptr.alloc_id, false)?; + self.memory.mark_static_initalized(ptr.alloc_id, false)?; Ok(Value::ByValPair(PrimVal::Ptr(ptr), PrimVal::from_u128(s.len() as u128))) } @@ -194,9 +194,10 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> { Str(ref s) => return self.str_to_value(s), ByteStr(ref bs) => { + // FIXME: cache these allocs let ptr = self.memory.allocate(bs.len() as u64, 1)?; self.memory.write_bytes(ptr, bs)?; - self.memory.mark_static(ptr.alloc_id, false)?; + self.memory.mark_static_initalized(ptr.alloc_id, false)?; PrimVal::Ptr(ptr) } @@ -316,16 +317,16 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> { let global_value = self.globals.get_mut(&id) .expect("global should have been cached (static)"); match global_value.value { - Value::ByRef(ptr) => self.memory.mark_static(ptr.alloc_id, mutable)?, + Value::ByRef(ptr) => self.memory.mark_static_initalized(ptr.alloc_id, mutable)?, Value::ByVal(val) => if let PrimVal::Ptr(ptr) = val { - self.memory.mark_static(ptr.alloc_id, mutable)?; + self.memory.mark_static_initalized(ptr.alloc_id, mutable)?; }, Value::ByValPair(val1, val2) => { if let PrimVal::Ptr(ptr) = val1 { - self.memory.mark_static(ptr.alloc_id, mutable)?; + self.memory.mark_static_initalized(ptr.alloc_id, mutable)?; } if let PrimVal::Ptr(ptr) = val2 { - self.memory.mark_static(ptr.alloc_id, mutable)?; + self.memory.mark_static_initalized(ptr.alloc_id, mutable)?; } }, } @@ -870,10 +871,11 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> { Value::ByRef(ptr) => Lvalue::from_ptr(ptr), _ => { let ptr = self.alloc_ptr_with_substs(global_val.ty, cid.substs)?; + self.memory.mark_static(ptr.alloc_id); self.write_value_to_ptr(global_val.value, ptr, global_val.ty)?; // see comment on `initialized` field if global_val.initialized { - self.memory.mark_static(ptr.alloc_id, global_val.mutable)?; + self.memory.mark_static_initalized(ptr.alloc_id, global_val.mutable)?; } let lval = self.globals.get_mut(&cid).expect("already checked"); *lval = Global { diff --git a/src/memory.rs b/src/memory.rs index 8f0c3a5622c..6dee7ce49a1 100644 --- a/src/memory.rs +++ b/src/memory.rs @@ -38,7 +38,7 @@ pub struct Allocation { /// The alignment of the allocation to detect unaligned reads. pub align: u64, /// Whether the allocation may be modified. - /// Use the `mark_static` method of `Memory` to ensure that an error occurs, if the memory of this + /// Use the `mark_static_initalized` method of `Memory` to ensure that an error occurs, if the memory of this /// allocation is modified or deallocated in the future. pub static_kind: StaticKind, } @@ -152,6 +152,11 @@ impl<'tcx> Function<'tcx> { pub struct Memory<'a, 'tcx> { /// Actual memory allocations (arbitrary bytes, may contain pointers into other allocations) alloc_map: HashMap, + /// Set of statics, constants, promoteds, vtables, ... to prevent `mark_static_initalized` from stepping + /// out of its own allocations. + /// This set only contains statics backed by an allocation. If they are ByVal or ByValPair they + /// are not here, but will be inserted once they become ByRef. + static_alloc: HashSet, /// Number of virtual bytes allocated memory_usage: u64, /// Maximum number of virtual bytes that may be allocated @@ -189,6 +194,7 @@ impl<'a, 'tcx> Memory<'a, 'tcx> { memory_size: max_memory, memory_usage: 0, packed: BTreeSet::new(), + static_alloc: HashSet::new(), } } @@ -624,8 +630,15 @@ impl<'a, 'tcx> Memory<'a, 'tcx> { /// Reading and writing impl<'a, 'tcx> Memory<'a, 'tcx> { - /// mark an allocation as static, either mutable or not - pub fn mark_static(&mut self, alloc_id: AllocId, mutable: bool) -> EvalResult<'tcx> { + /// mark an allocation as being the entry point to a static (see `static_alloc` field) + pub fn mark_static(&mut self, alloc_id: AllocId) { + if !self.static_alloc.insert(alloc_id) { + bug!("tried to mark an allocation ({:?}) as static twice", alloc_id); + } + } + + /// mark an allocation as static and initialized, either mutable or not + pub fn mark_static_initalized(&mut self, alloc_id: AllocId, mutable: bool) -> EvalResult<'tcx> { // do not use `self.get_mut(alloc_id)` here, because we might have already marked a // sub-element or have circular pointers (e.g. `Rc`-cycles) let relocations = match self.alloc_map.get_mut(&alloc_id) { @@ -645,7 +658,10 @@ impl<'a, 'tcx> Memory<'a, 'tcx> { }; // recurse into inner allocations for &alloc in relocations.values() { - self.mark_static(alloc, mutable)?; + // relocations into other statics are not "inner allocations" + if !self.static_alloc.contains(&alloc) { + self.mark_static_initalized(alloc, mutable)?; + } } // put back the relocations self.alloc_map.get_mut(&alloc_id).expect("checked above").relocations = relocations; diff --git a/src/vtable.rs b/src/vtable.rs index 0b43b349443..bfae608ecbc 100644 --- a/src/vtable.rs +++ b/src/vtable.rs @@ -112,7 +112,7 @@ impl<'a, 'tcx> EvalContext<'a, 'tcx> { } } - self.memory.mark_static(vtable.alloc_id, false)?; + self.memory.mark_static_initalized(vtable.alloc_id, false)?; Ok(vtable) }