Rollup merge of #104357 - RalfJung:is-sized, r=cjgillot

add is_sized method on Abi and Layout, and use it

This avoids the double negation of `!is_unsized()` that we have quite a lot.

Author: matthiaskrgr

Diff for: compiler/rustc_codegen_cranelift/src/constant.rs

@@ -128,7 +128,7 @@ pub(crate) fn codegen_const_value<'tcx>(
     ty: Ty<'tcx>,
 ) -> CValue<'tcx> {
     let layout = fx.layout_of(ty);
-    assert!(!layout.is_unsized(), "sized const value");
+    assert!(layout.is_sized(), "unsized const value");
 
     if layout.is_zst() {
         return CValue::by_ref(crate::Pointer::dangling(layout.align.pref), layout);

Diff for: compiler/rustc_codegen_cranelift/src/value_and_place.rs

@@ -19,7 +19,7 @@ fn codegen_field<'tcx>(
     };
 
     if let Some(extra) = extra {
-        if !field_layout.is_unsized() {
+        if field_layout.is_sized() {
             return simple(fx);
         }
         match field_layout.ty.kind() {
@@ -364,7 +364,7 @@ impl<'tcx> CPlace<'tcx> {
         fx: &mut FunctionCx<'_, '_, 'tcx>,
         layout: TyAndLayout<'tcx>,
     ) -> CPlace<'tcx> {
-        assert!(!layout.is_unsized());
+        assert!(layout.is_sized());
         if layout.size.bytes() == 0 {
             return CPlace {
                 inner: CPlaceInner::Addr(Pointer::dangling(layout.align.pref), None),
@@ -825,7 +825,7 @@ impl<'tcx> CPlace<'tcx> {
         fx: &FunctionCx<'_, '_, 'tcx>,
         variant: VariantIdx,
     ) -> Self {
-        assert!(!self.layout().is_unsized());
+        assert!(self.layout().is_sized());
         let layout = self.layout().for_variant(fx, variant);
         CPlace { inner: self.inner, layout }
     }

Diff for: compiler/rustc_codegen_gcc/src/type_.rs

@@ -277,7 +277,7 @@ pub fn struct_fields<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, layout: TyAndLayout
         offset = target_offset + field.size;
         prev_effective_align = effective_field_align;
     }
-    if !layout.is_unsized() && field_count > 0 {
+    if layout.is_sized() && field_count > 0 {
         if offset > layout.size {
             bug!("layout: {:#?} stride: {:?} offset: {:?}", layout, layout.size, offset);
         }

Diff for: compiler/rustc_codegen_llvm/src/debuginfo/utils.rs

@@ -72,7 +72,7 @@ pub(crate) fn fat_pointer_kind<'ll, 'tcx>(
         layout.is_unsized()
     );
 
-    if !layout.is_unsized() {
+    if layout.is_sized() {
         return None;
     }
 

Diff for: compiler/rustc_codegen_llvm/src/type_of.rs

@@ -140,7 +140,7 @@ fn struct_llfields<'a, 'tcx>(
         prev_effective_align = effective_field_align;
     }
     let padding_used = result.len() > field_count;
-    if !layout.is_unsized() && field_count > 0 {
+    if layout.is_sized() && field_count > 0 {
         if offset > layout.size {
             bug!("layout: {:#?} stride: {:?} offset: {:?}", layout, layout.size, offset);
         }

Diff for: compiler/rustc_codegen_ssa/src/glue.rs

@@ -15,7 +15,7 @@ pub fn size_and_align_of_dst<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
 ) -> (Bx::Value, Bx::Value) {
     let layout = bx.layout_of(t);
     debug!("size_and_align_of_dst(ty={}, info={:?}): layout: {:?}", t, info, layout);
-    if !layout.is_unsized() {
+    if layout.is_sized() {
         let size = bx.const_usize(layout.size.bytes());
         let align = bx.const_usize(layout.align.abi.bytes());
         return (size, align);

Diff for: compiler/rustc_codegen_ssa/src/mir/place.rs

@@ -29,7 +29,7 @@ pub struct PlaceRef<'tcx, V> {
 
 impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> {
     pub fn new_sized(llval: V, layout: TyAndLayout<'tcx>) -> PlaceRef<'tcx, V> {
-        assert!(!layout.is_unsized());
+        assert!(layout.is_sized());
         PlaceRef { llval, llextra: None, layout, align: layout.align.abi }
     }
 
@@ -38,7 +38,7 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> {
         layout: TyAndLayout<'tcx>,
         align: Align,
     ) -> PlaceRef<'tcx, V> {
-        assert!(!layout.is_unsized());
+        assert!(layout.is_sized());
         PlaceRef { llval, llextra: None, layout, align }
     }
 
@@ -48,7 +48,7 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> {
         bx: &mut Bx,
         layout: TyAndLayout<'tcx>,
     ) -> Self {
-        assert!(!layout.is_unsized(), "tried to statically allocate unsized place");
+        assert!(layout.is_sized(), "tried to statically allocate unsized place");
         let tmp = bx.alloca(bx.cx().backend_type(layout), layout.align.abi);
         Self::new_sized(tmp, layout)
     }
@@ -145,7 +145,7 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> {
                 );
                 return simple();
             }
-            _ if !field.is_unsized() => return simple(),
+            _ if field.is_sized() => return simple(),
             ty::Slice(..) | ty::Str | ty::Foreign(..) => return simple(),
             ty::Adt(def, _) => {
                 if def.repr().packed() {

Diff for: compiler/rustc_const_eval/src/const_eval/eval_queries.rs

@@ -46,7 +46,7 @@ fn eval_body_using_ecx<'mir, 'tcx>(
         ecx.tcx.def_kind(cid.instance.def_id())
     );
     let layout = ecx.layout_of(body.bound_return_ty().subst(tcx, cid.instance.substs))?;
-    assert!(!layout.is_unsized());
+    assert!(layout.is_sized());
     let ret = ecx.allocate(layout, MemoryKind::Stack)?;
 
     trace!(

Diff for: compiler/rustc_const_eval/src/interpret/eval_context.rs

@@ -572,7 +572,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         metadata: &MemPlaceMeta<M::Provenance>,
         layout: &TyAndLayout<'tcx>,
     ) -> InterpResult<'tcx, Option<(Size, Align)>> {
-        if !layout.is_unsized() {
+        if layout.is_sized() {
             return Ok(Some((layout.size, layout.align.abi)));
         }
         match layout.ty.kind() {

Diff for: compiler/rustc_const_eval/src/interpret/intrinsics.rs

@@ -713,7 +713,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         rhs: &OpTy<'tcx, <M as Machine<'mir, 'tcx>>::Provenance>,
     ) -> InterpResult<'tcx, Scalar<M::Provenance>> {
         let layout = self.layout_of(lhs.layout.ty.builtin_deref(true).unwrap().ty)?;
-        assert!(!layout.is_unsized());
+        assert!(layout.is_sized());
 
         let get_bytes = |this: &InterpCx<'mir, 'tcx, M>,
                          op: &OpTy<'tcx, <M as Machine<'mir, 'tcx>>::Provenance>,

Diff for: compiler/rustc_const_eval/src/interpret/memory.rs

@@ -683,7 +683,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 // Use size and align of the type.
                 let ty = self.tcx.type_of(def_id);
                 let layout = self.tcx.layout_of(ParamEnv::empty().and(ty)).unwrap();
-                assert!(!layout.is_unsized());
+                assert!(layout.is_sized());
                 (layout.size, layout.align.abi, AllocKind::LiveData)
             }
             Some(GlobalAlloc::Memory(alloc)) => {

Diff for: compiler/rustc_const_eval/src/interpret/operand.rs

@@ -280,7 +280,7 @@ impl<'tcx, Prov: Provenance> OpTy<'tcx, Prov> {
         layout: TyAndLayout<'tcx>,
         cx: &impl HasDataLayout,
     ) -> InterpResult<'tcx, Self> {
-        assert!(!layout.is_unsized());
+        assert!(layout.is_sized());
         self.offset_with_meta(offset, MemPlaceMeta::None, layout, cx)
     }
 }

Diff for: compiler/rustc_const_eval/src/interpret/place.rs

@@ -201,7 +201,7 @@ impl<'tcx, Prov: Provenance> MPlaceTy<'tcx, Prov> {
         layout: TyAndLayout<'tcx>,
         cx: &impl HasDataLayout,
     ) -> InterpResult<'tcx, Self> {
-        assert!(!layout.is_unsized());
+        assert!(layout.is_sized());
         self.offset_with_meta(offset, MemPlaceMeta::None, layout, cx)
     }
 
@@ -340,7 +340,7 @@ where
         &self,
         place: &MPlaceTy<'tcx, M::Provenance>,
     ) -> InterpResult<'tcx, Option<AllocRef<'_, 'tcx, M::Provenance, M::AllocExtra>>> {
-        assert!(!place.layout.is_unsized());
+        assert!(place.layout.is_sized());
         assert!(!place.meta.has_meta());
         let size = place.layout.size;
         self.get_ptr_alloc(place.ptr, size, place.align)
@@ -351,7 +351,7 @@ where
         &mut self,
         place: &MPlaceTy<'tcx, M::Provenance>,
     ) -> InterpResult<'tcx, Option<AllocRefMut<'_, 'tcx, M::Provenance, M::AllocExtra>>> {
-        assert!(!place.layout.is_unsized());
+        assert!(place.layout.is_sized());
         assert!(!place.meta.has_meta());
         let size = place.layout.size;
         self.get_ptr_alloc_mut(place.ptr, size, place.align)
@@ -485,7 +485,7 @@ where
         src: Immediate<M::Provenance>,
         dest: &PlaceTy<'tcx, M::Provenance>,
     ) -> InterpResult<'tcx> {
-        assert!(!dest.layout.is_unsized(), "Cannot write unsized data");
+        assert!(dest.layout.is_sized(), "Cannot write unsized data");
         trace!("write_immediate: {:?} <- {:?}: {}", *dest, src, dest.layout.ty);
 
         // See if we can avoid an allocation. This is the counterpart to `read_immediate_raw`,
@@ -746,7 +746,7 @@ where
         layout: TyAndLayout<'tcx>,
         kind: MemoryKind<M::MemoryKind>,
     ) -> InterpResult<'tcx, MPlaceTy<'tcx, M::Provenance>> {
-        assert!(!layout.is_unsized());
+        assert!(layout.is_sized());
         let ptr = self.allocate_ptr(layout.size, layout.align.abi, kind)?;
         Ok(MPlaceTy::from_aligned_ptr(ptr.into(), layout))
     }

Diff for: compiler/rustc_const_eval/src/interpret/step.rs

@@ -209,7 +209,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
 
             Repeat(ref operand, _) => {
                 let src = self.eval_operand(operand, None)?;
-                assert!(!src.layout.is_unsized());
+                assert!(src.layout.is_sized());
                 let dest = self.force_allocation(&dest)?;
                 let length = dest.len(self)?;
 

Diff for: compiler/rustc_const_eval/src/interpret/traits.rs

@@ -53,7 +53,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
     ) -> InterpResult<'tcx, (Size, Align)> {
         let (ty, _trait_ref) = self.get_ptr_vtable(vtable)?;
         let layout = self.layout_of(ty)?;
-        assert!(!layout.is_unsized(), "there are no vtables for unsized types");
+        assert!(layout.is_sized(), "there are no vtables for unsized types");
         Ok((layout.size, layout.align.abi))
     }
 }

Diff for: compiler/rustc_middle/src/ty/vtable.rs

@@ -66,7 +66,7 @@ pub(super) fn vtable_allocation_provider<'tcx>(
     let layout = tcx
         .layout_of(ty::ParamEnv::reveal_all().and(ty))
         .expect("failed to build vtable representation");
-    assert!(!layout.is_unsized(), "can't create a vtable for an unsized type");
+    assert!(layout.is_sized(), "can't create a vtable for an unsized type");
     let size = layout.size.bytes();
     let align = layout.align.abi.bytes();
 

Diff for: compiler/rustc_mir_transform/src/const_prop.rs

@@ -385,7 +385,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
             // I don't know how return types can seem to be unsized but this happens in the
             // `type/type-unsatisfiable.rs` test.
             .filter(|ret_layout| {
-                !ret_layout.is_unsized() && ret_layout.size < Size::from_bytes(MAX_ALLOC_LIMIT)
+                ret_layout.is_sized() && ret_layout.size < Size::from_bytes(MAX_ALLOC_LIMIT)
             })
             .unwrap_or_else(|| ecx.layout_of(tcx.types.unit).unwrap());
 

Diff for: compiler/rustc_mir_transform/src/const_prop_lint.rs

@@ -199,7 +199,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
             // I don't know how return types can seem to be unsized but this happens in the
             // `type/type-unsatisfiable.rs` test.
             .filter(|ret_layout| {
-                !ret_layout.is_unsized() && ret_layout.size < Size::from_bytes(MAX_ALLOC_LIMIT)
+                ret_layout.is_sized() && ret_layout.size < Size::from_bytes(MAX_ALLOC_LIMIT)
             })
             .unwrap_or_else(|| ecx.layout_of(tcx.types.unit).unwrap());
 

Diff for: compiler/rustc_target/src/abi/mod.rs

@@ -1083,6 +1083,11 @@ impl Abi {
         }
     }
 
+    #[inline]
+    pub fn is_sized(&self) -> bool {
+        !self.is_unsized()
+    }
+
     /// Returns `true` if this is a single signed integer scalar
     #[inline]
     pub fn is_signed(&self) -> bool {
@@ -1490,6 +1495,11 @@ impl<'a, Ty> TyAndLayout<'a, Ty> {
         self.abi.is_unsized()
     }
 
+    #[inline]
+    pub fn is_sized(&self) -> bool {
+        self.abi.is_sized()
+    }
+
     /// Returns `true` if the type is a ZST and not unsized.
     pub fn is_zst(&self) -> bool {
         match self.abi {

Diff for: compiler/rustc_ty_utils/src/layout.rs

@@ -668,7 +668,7 @@ fn layout_of_uncached<'tcx>(
                 let mut abi = Abi::Aggregate { sized: true };
                 let index = VariantIdx::new(0);
                 for field in &variants[index] {
-                    assert!(!field.is_unsized());
+                    assert!(field.is_sized());
                     align = align.max(field.align);
 
                     // If all non-ZST fields have the same ABI, forward this ABI

Diff for: src/tools/miri/src/stacked_borrows/mod.rs

@@ -1053,7 +1053,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 // pointers we need to retag, so we can stop recursion early.
                 // This optimization is crucial for ZSTs, because they can contain way more fields
                 // than we can ever visit.
-                if !place.layout.is_unsized() && place.layout.size < self.ecx.pointer_size() {
+                if place.layout.is_sized() && place.layout.size < self.ecx.pointer_size() {
                     return Ok(());
                 }