diff options
Diffstat (limited to 'compiler/rustc_const_eval/src/interpret/validity.rs')
| -rw-r--r-- | compiler/rustc_const_eval/src/interpret/validity.rs | 98 |
1 files changed, 30 insertions, 68 deletions
diff --git a/compiler/rustc_const_eval/src/interpret/validity.rs b/compiler/rustc_const_eval/src/interpret/validity.rs index cd2c1ef3613..273eaf42d87 100644 --- a/compiler/rustc_const_eval/src/interpret/validity.rs +++ b/compiler/rustc_const_eval/src/interpret/validity.rs @@ -31,8 +31,8 @@ use tracing::trace; use super::machine::AllocMap; use super::{ - AllocId, AllocKind, CheckInAllocMsg, GlobalAlloc, ImmTy, Immediate, InterpCx, InterpResult, - MPlaceTy, Machine, MemPlaceMeta, PlaceTy, Pointer, Projectable, Scalar, ValueVisitor, err_ub, + AllocId, CheckInAllocMsg, GlobalAlloc, ImmTy, Immediate, InterpCx, InterpResult, MPlaceTy, + Machine, MemPlaceMeta, PlaceTy, Pointer, Projectable, Scalar, ValueVisitor, err_ub, format_interp_error, }; @@ -448,7 +448,7 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValidityVisitor<'rt, 'tcx, M> { meta: MemPlaceMeta<M::Provenance>, pointee: TyAndLayout<'tcx>, ) -> InterpResult<'tcx> { - let tail = self.ecx.tcx.struct_tail_for_codegen(pointee.ty, self.ecx.param_env); + let tail = self.ecx.tcx.struct_tail_for_codegen(pointee.ty, self.ecx.typing_env); match tail.kind() { ty::Dynamic(data, _, ty::Dyn) => { let vtable = meta.unwrap_meta().to_pointer(self.ecx)?; @@ -557,9 +557,20 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValidityVisitor<'rt, 'tcx, M> { if let Ok((alloc_id, _offset, _prov)) = self.ecx.ptr_try_get_alloc_id(place.ptr(), 0) { - if let Some(GlobalAlloc::Static(did)) = - self.ecx.tcx.try_get_global_alloc(alloc_id) - { + // Everything should be already interned. + let Some(global_alloc) = self.ecx.tcx.try_get_global_alloc(alloc_id) else { + assert!(self.ecx.memory.alloc_map.get(alloc_id).is_none()); + // We can't have *any* references to non-existing allocations in const-eval + // as the rest of rustc isn't happy with them... so we throw an error, even + // though for zero-sized references this isn't really UB. + // A potential future alternative would be to resurrect this as a zero-sized allocation + // (which codegen will then compile to an aligned dummy pointer anyway). + throw_validation_failure!(self.path, DanglingPtrUseAfterFree { ptr_kind }); + }; + let (size, _align) = + global_alloc.size_and_align(*self.ecx.tcx, self.ecx.typing_env); + + if let GlobalAlloc::Static(did) = global_alloc { let DefKind::Static { nested, .. } = self.ecx.tcx.def_kind(did) else { bug!() }; @@ -593,17 +604,6 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValidityVisitor<'rt, 'tcx, M> { } } - // Dangling and Mutability check. - let (size, _align, alloc_kind) = self.ecx.get_alloc_info(alloc_id); - if alloc_kind == AllocKind::Dead { - // This can happen for zero-sized references. We can't have *any* references to - // non-existing allocations in const-eval though, interning rejects them all as - // the rest of rustc isn't happy with them... so we throw an error, even though - // this isn't really UB. - // A potential future alternative would be to resurrect this as a zero-sized allocation - // (which codegen will then compile to an aligned dummy pointer anyway). - throw_validation_failure!(self.path, DanglingPtrUseAfterFree { ptr_kind }); - } // If this allocation has size zero, there is no actual mutability here. if size != Size::ZERO { // Determine whether this pointer expects to be pointing to something mutable. @@ -618,7 +618,8 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValidityVisitor<'rt, 'tcx, M> { } }; // Determine what it actually points to. - let alloc_actual_mutbl = mutability(self.ecx, alloc_id); + let alloc_actual_mutbl = + global_alloc.mutability(*self.ecx.tcx, self.ecx.typing_env); // Mutable pointer to immutable memory is no good. if ptr_expected_mutbl == Mutability::Mut && alloc_actual_mutbl == Mutability::Not @@ -842,9 +843,16 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValidityVisitor<'rt, 'tcx, M> { } fn in_mutable_memory(&self, val: &PlaceTy<'tcx, M::Provenance>) -> bool { + debug_assert!(self.ctfe_mode.is_some()); if let Some(mplace) = val.as_mplace_or_local().left() { if let Some(alloc_id) = mplace.ptr().provenance.and_then(|p| p.get_alloc_id()) { - mutability(self.ecx, alloc_id).is_mut() + let tcx = *self.ecx.tcx; + // Everything must be already interned. + let mutbl = tcx.global_alloc(alloc_id).mutability(tcx, self.ecx.typing_env); + if let Some((_, alloc)) = self.ecx.memory.alloc_map.get(alloc_id) { + assert_eq!(alloc.mutability, mutbl); + } + mutbl.is_mut() } else { // No memory at all. false @@ -947,7 +955,7 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValidityVisitor<'rt, 'tcx, M> { ) -> Cow<'e, RangeSet> { assert!(layout.ty.is_union()); assert!(layout.is_sized(), "there are no unsized unions"); - let layout_cx = LayoutCx::new(*ecx.tcx, ecx.param_env); + let layout_cx = LayoutCx::new(*ecx.tcx, ecx.typing_env); return M::cached_union_data_range(ecx, layout.ty, || { let mut out = RangeSet(Vec::new()); union_data_range_uncached(&layout_cx, layout, Size::ZERO, &mut out); @@ -1016,53 +1024,6 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValidityVisitor<'rt, 'tcx, M> { } } -/// Returns whether the allocation is mutable, and whether it's actually a static. -/// For "root" statics we look at the type to account for interior -/// mutability; for nested statics we have no type and directly use the annotated mutability. -fn mutability<'tcx>(ecx: &InterpCx<'tcx, impl Machine<'tcx>>, alloc_id: AllocId) -> Mutability { - // Let's see what kind of memory this points to. - // We're not using `try_global_alloc` since dangling pointers have already been handled. - match ecx.tcx.global_alloc(alloc_id) { - GlobalAlloc::Static(did) => { - let DefKind::Static { safety: _, mutability, nested } = ecx.tcx.def_kind(did) else { - bug!() - }; - if nested { - assert!( - ecx.memory.alloc_map.get(alloc_id).is_none(), - "allocations of nested statics are already interned: {alloc_id:?}, {did:?}" - ); - // Nested statics in a `static` are never interior mutable, - // so just use the declared mutability. - mutability - } else { - let mutability = match mutability { - Mutability::Not - if !ecx - .tcx - .type_of(did) - .no_bound_vars() - .expect("statics should not have generic parameters") - .is_freeze(*ecx.tcx, ty::ParamEnv::reveal_all()) => - { - Mutability::Mut - } - _ => mutability, - }; - if let Some((_, alloc)) = ecx.memory.alloc_map.get(alloc_id) { - assert_eq!(alloc.mutability, mutability); - } - mutability - } - } - GlobalAlloc::Memory(alloc) => alloc.inner().mutability, - GlobalAlloc::Function { .. } | GlobalAlloc::VTable(..) => { - // These are immutable, we better don't allow mutable pointers here. - Mutability::Not - } - } -} - impl<'rt, 'tcx, M: Machine<'tcx>> ValueVisitor<'tcx, M> for ValidityVisitor<'rt, 'tcx, M> { type V = PlaceTy<'tcx, M::Provenance>; @@ -1124,7 +1085,8 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValueVisitor<'tcx, M> for ValidityVisitor<'rt, ) -> InterpResult<'tcx> { // Special check for CTFE validation, preventing `UnsafeCell` inside unions in immutable memory. if self.ctfe_mode.is_some_and(|c| !c.allow_immutable_unsafe_cell()) { - if !val.layout.is_zst() && !val.layout.ty.is_freeze(*self.ecx.tcx, self.ecx.param_env) { + if !val.layout.is_zst() && !val.layout.ty.is_freeze(*self.ecx.tcx, self.ecx.typing_env) + { if !self.in_mutable_memory(val) { throw_validation_failure!(self.path, UnsafeCellInImmutable); } |