diff options
Diffstat (limited to 'compiler/rustc_ty_utils/src/layout/invariant.rs')
| -rw-r--r-- | compiler/rustc_ty_utils/src/layout/invariant.rs | 122 |
1 files changed, 70 insertions, 52 deletions
diff --git a/compiler/rustc_ty_utils/src/layout/invariant.rs b/compiler/rustc_ty_utils/src/layout/invariant.rs index f39b87622f4..7e2375154c0 100644 --- a/compiler/rustc_ty_utils/src/layout/invariant.rs +++ b/compiler/rustc_ty_utils/src/layout/invariant.rs @@ -241,63 +241,81 @@ pub(super) fn layout_sanity_check<'tcx>(cx: &LayoutCx<'tcx>, layout: &TyAndLayou check_layout_abi(cx, layout); - if let Variants::Multiple { variants, tag, tag_encoding, .. } = &layout.variants { - if let TagEncoding::Niche { niche_start, untagged_variant, niche_variants } = tag_encoding { - let niche_size = tag.size(cx); - assert!(*niche_start <= niche_size.unsigned_int_max()); - for (idx, variant) in variants.iter_enumerated() { - // Ensure all inhabited variants are accounted for. - if !variant.is_uninhabited() { - assert!(idx == *untagged_variant || niche_variants.contains(&idx)); - } - } + match &layout.variants { + Variants::Single { index: None } => { + assert!(layout.is_uninhabited()); } - for variant in variants.iter() { - // No nested "multiple". - assert_matches!(variant.variants, Variants::Single { .. }); - // Variants should have the same or a smaller size as the full thing, - // and same for alignment. - if variant.size > layout.size { - bug!( - "Type with size {} bytes has variant with size {} bytes: {layout:#?}", - layout.size.bytes(), - variant.size.bytes(), - ) + Variants::Single { index: Some(idx) } => { + if let Some(variants) = layout.ty.variant_range(tcx) { + assert!(variants.contains(idx)); + } else { + // Types without variants use `0` as dummy variant index. + assert!(idx.as_u32() == 0); } - if variant.align.abi > layout.align.abi { - bug!( - "Type with alignment {} bytes has variant with alignment {} bytes: {layout:#?}", - layout.align.abi.bytes(), - variant.align.abi.bytes(), - ) - } - // Skip empty variants. - if variant.size == Size::ZERO || variant.fields.count() == 0 || variant.is_uninhabited() + } + Variants::Multiple { variants, tag, tag_encoding, .. } => { + if let TagEncoding::Niche { niche_start, untagged_variant, niche_variants } = + tag_encoding { - // These are never actually accessed anyway, so we can skip the coherence check - // for them. They also fail that check, since they have - // `Aggregate`/`Uninhabited` ABI even when the main type is - // `Scalar`/`ScalarPair`. (Note that sometimes, variants with fields have size - // 0, and sometimes, variants without fields have non-0 size.) - continue; + let niche_size = tag.size(cx); + assert!(*niche_start <= niche_size.unsigned_int_max()); + for (idx, variant) in variants.iter_enumerated() { + // Ensure all inhabited variants are accounted for. + if !variant.is_uninhabited() { + assert!(idx == *untagged_variant || niche_variants.contains(&idx)); + } + } } - // The top-level ABI and the ABI of the variants should be coherent. - let scalar_coherent = - |s1: Scalar, s2: Scalar| s1.size(cx) == s2.size(cx) && s1.align(cx) == s2.align(cx); - let abi_coherent = match (layout.backend_repr, variant.backend_repr) { - (BackendRepr::Scalar(s1), BackendRepr::Scalar(s2)) => scalar_coherent(s1, s2), - (BackendRepr::ScalarPair(a1, b1), BackendRepr::ScalarPair(a2, b2)) => { - scalar_coherent(a1, a2) && scalar_coherent(b1, b2) + for variant in variants.iter() { + // No nested "multiple". + assert_matches!(variant.variants, Variants::Single { .. }); + // Variants should have the same or a smaller size as the full thing, + // and same for alignment. + if variant.size > layout.size { + bug!( + "Type with size {} bytes has variant with size {} bytes: {layout:#?}", + layout.size.bytes(), + variant.size.bytes(), + ) + } + if variant.align.abi > layout.align.abi { + bug!( + "Type with alignment {} bytes has variant with alignment {} bytes: {layout:#?}", + layout.align.abi.bytes(), + variant.align.abi.bytes(), + ) + } + // Skip empty variants. + if variant.size == Size::ZERO + || variant.fields.count() == 0 + || variant.is_uninhabited() + { + // These are never actually accessed anyway, so we can skip the coherence check + // for them. They also fail that check, since they have + // `Aggregate`/`Uninhabited` ABI even when the main type is + // `Scalar`/`ScalarPair`. (Note that sometimes, variants with fields have size + // 0, and sometimes, variants without fields have non-0 size.) + continue; + } + // The top-level ABI and the ABI of the variants should be coherent. + let scalar_coherent = |s1: Scalar, s2: Scalar| { + s1.size(cx) == s2.size(cx) && s1.align(cx) == s2.align(cx) + }; + let abi_coherent = match (layout.backend_repr, variant.backend_repr) { + (BackendRepr::Scalar(s1), BackendRepr::Scalar(s2)) => scalar_coherent(s1, s2), + (BackendRepr::ScalarPair(a1, b1), BackendRepr::ScalarPair(a2, b2)) => { + scalar_coherent(a1, a2) && scalar_coherent(b1, b2) + } + (BackendRepr::Uninhabited, _) => true, + (BackendRepr::Memory { .. }, _) => true, + _ => false, + }; + if !abi_coherent { + bug!( + "Variant ABI is incompatible with top-level ABI:\nvariant={:#?}\nTop-level: {layout:#?}", + variant + ); } - (BackendRepr::Uninhabited, _) => true, - (BackendRepr::Memory { .. }, _) => true, - _ => false, - }; - if !abi_coherent { - bug!( - "Variant ABI is incompatible with top-level ABI:\nvariant={:#?}\nTop-level: {layout:#?}", - variant - ); } } } |