diff options
Diffstat (limited to 'compiler/rustc_middle/src')
4 files changed, 54 insertions, 1 deletions
diff --git a/compiler/rustc_middle/src/mir/interpret/allocation.rs b/compiler/rustc_middle/src/mir/interpret/allocation.rs index 509f2667b35..d6f8fed755f 100644 --- a/compiler/rustc_middle/src/mir/interpret/allocation.rs +++ b/compiler/rustc_middle/src/mir/interpret/allocation.rs @@ -643,6 +643,28 @@ impl<Prov: Provenance, Extra, Bytes: AllocBytes> Allocation<Prov, Extra, Bytes> Ok(()) } + /// Initialize all previously uninitialized bytes in the entire allocation, and set + /// provenance of everything to `Wildcard`. Before calling this, make sure all + /// provenance in this allocation is exposed! + pub fn prepare_for_native_write(&mut self) -> AllocResult { + let full_range = AllocRange { start: Size::ZERO, size: Size::from_bytes(self.len()) }; + // Overwrite uninitialized bytes with 0, to ensure we don't leak whatever their value happens to be. + for chunk in self.init_mask.range_as_init_chunks(full_range) { + if !chunk.is_init() { + let uninit_bytes = &mut self.bytes + [chunk.range().start.bytes_usize()..chunk.range().end.bytes_usize()]; + uninit_bytes.fill(0); + } + } + // Mark everything as initialized now. + self.mark_init(full_range, true); + + // Set provenance of all bytes to wildcard. + self.provenance.write_wildcards(self.len()); + + Ok(()) + } + /// Remove all provenance in the given memory range. pub fn clear_provenance(&mut self, cx: &impl HasDataLayout, range: AllocRange) -> AllocResult { self.provenance.clear(range, cx)?; diff --git a/compiler/rustc_middle/src/mir/interpret/allocation/provenance_map.rs b/compiler/rustc_middle/src/mir/interpret/allocation/provenance_map.rs index 5c47fc6a399..3a83b184d83 100644 --- a/compiler/rustc_middle/src/mir/interpret/allocation/provenance_map.rs +++ b/compiler/rustc_middle/src/mir/interpret/allocation/provenance_map.rs @@ -195,6 +195,25 @@ impl<Prov: Provenance> ProvenanceMap<Prov> { Ok(()) } + + /// Overwrites all provenance in the allocation with wildcard provenance. + /// + /// Provided for usage in Miri and panics otherwise. + pub fn write_wildcards(&mut self, alloc_size: usize) { + assert!( + Prov::OFFSET_IS_ADDR, + "writing wildcard provenance is not supported when `OFFSET_IS_ADDR` is false" + ); + let wildcard = Prov::WILDCARD.unwrap(); + + // Remove all pointer provenances, then write wildcards into the whole byte range. + self.ptrs.clear(); + let last = Size::from_bytes(alloc_size); + let bytes = self.bytes.get_or_insert_with(Box::default); + for offset in Size::ZERO..last { + bytes.insert(offset, wildcard); + } + } } /// A partial, owned list of provenance to transfer into another allocation. diff --git a/compiler/rustc_middle/src/mir/interpret/pointer.rs b/compiler/rustc_middle/src/mir/interpret/pointer.rs index 1d5afe22573..25c7c26ddd9 100644 --- a/compiler/rustc_middle/src/mir/interpret/pointer.rs +++ b/compiler/rustc_middle/src/mir/interpret/pointer.rs @@ -66,6 +66,9 @@ pub trait Provenance: Copy + fmt::Debug + 'static { /// pointer, and implement ptr-to-int transmutation by stripping provenance. const OFFSET_IS_ADDR: bool; + /// If wildcard provenance is implemented, contains the unique, general wildcard provenance variant. + const WILDCARD: Option<Self>; + /// Determines how a pointer should be printed. fn fmt(ptr: &Pointer<Self>, f: &mut fmt::Formatter<'_>) -> fmt::Result; @@ -168,6 +171,9 @@ impl Provenance for CtfeProvenance { // so ptr-to-int casts are not possible (since we do not know the global physical offset). const OFFSET_IS_ADDR: bool = false; + // `CtfeProvenance` does not implement wildcard provenance. + const WILDCARD: Option<Self> = None; + fn fmt(ptr: &Pointer<Self>, f: &mut fmt::Formatter<'_>) -> fmt::Result { // Print AllocId. fmt::Debug::fmt(&ptr.provenance.alloc_id(), f)?; // propagates `alternate` flag @@ -197,6 +203,9 @@ impl Provenance for AllocId { // so ptr-to-int casts are not possible (since we do not know the global physical offset). const OFFSET_IS_ADDR: bool = false; + // `AllocId` does not implement wildcard provenance. + const WILDCARD: Option<Self> = None; + fn fmt(ptr: &Pointer<Self>, f: &mut fmt::Formatter<'_>) -> fmt::Result { // Forward `alternate` flag to `alloc_id` printing. if f.alternate() { diff --git a/compiler/rustc_middle/src/ty/layout.rs b/compiler/rustc_middle/src/ty/layout.rs index 01ad76aedc3..07573a79260 100644 --- a/compiler/rustc_middle/src/ty/layout.rs +++ b/compiler/rustc_middle/src/ty/layout.rs @@ -552,7 +552,10 @@ impl<'tcx> HasWasmCAbiOpt for TyCtxt<'tcx> { impl<'tcx> HasX86AbiOpt for TyCtxt<'tcx> { fn x86_abi_opt(&self) -> X86Abi { - X86Abi { regparm: self.sess.opts.unstable_opts.regparm } + X86Abi { + regparm: self.sess.opts.unstable_opts.regparm, + reg_struct_return: self.sess.opts.unstable_opts.reg_struct_return, + } } } |