diff options
Diffstat (limited to 'src/librustc_codegen_llvm')
| -rw-r--r-- | src/librustc_codegen_llvm/debuginfo/metadata.rs | 36 | ||||
| -rw-r--r-- | src/librustc_codegen_llvm/type_of.rs | 34 |
2 files changed, 39 insertions, 31 deletions
diff --git a/src/librustc_codegen_llvm/debuginfo/metadata.rs b/src/librustc_codegen_llvm/debuginfo/metadata.rs index ca056c6034a..6560ed0a8e6 100644 --- a/src/librustc_codegen_llvm/debuginfo/metadata.rs +++ b/src/librustc_codegen_llvm/debuginfo/metadata.rs @@ -22,6 +22,7 @@ use rustc::hir::CodegenFnAttrFlags; use rustc::hir::def::CtorKind; use rustc::hir::def_id::{DefId, CrateNum, LOCAL_CRATE}; use rustc::ich::NodeIdHashingMode; +use rustc::mir::Field; use rustc::mir::interpret::truncate; use rustc_data_structures::fingerprint::Fingerprint; use rustc::ty::Instance; @@ -1306,12 +1307,15 @@ impl EnumMemberDescriptionFactory<'ll, 'tcx> { } layout::Variants::Multiple { discr_kind: layout::DiscriminantKind::Tag, + discr_index, ref variants, .. } => { let discriminant_info = if fallback { - RegularDiscriminant(self.discriminant_type_metadata - .expect("")) + RegularDiscriminant { + discr_field: Field::from(discr_index), + discr_type_metadata: self.discriminant_type_metadata.unwrap() + } } else { // This doesn't matter in this case. NoDiscriminant @@ -1358,6 +1362,7 @@ impl EnumMemberDescriptionFactory<'ll, 'tcx> { }, ref discr, ref variants, + discr_index, } => { if fallback { let variant = self.layout.for_variant(cx, dataful_variant); @@ -1403,8 +1408,8 @@ impl EnumMemberDescriptionFactory<'ll, 'tcx> { } compute_field_path(cx, &mut name, self.layout, - self.layout.fields.offset(0), - self.layout.field(cx, 0).size); + self.layout.fields.offset(discr_index), + self.layout.field(cx, discr_index).size); name.push_str(&adt.variants[*niche_variants.start()].ident.as_str()); // Create the (singleton) list of descriptions of union members. @@ -1486,6 +1491,8 @@ impl VariantMemberDescriptionFactory<'ll, 'tcx> { name: name.to_string(), type_metadata: if use_enum_fallback(cx) { match self.discriminant_type_metadata { + // Discriminant is always the first field of our variant + // when using the enum fallback. Some(metadata) if i == 0 => metadata, _ => type_metadata(cx, ty, self.span) } @@ -1504,7 +1511,7 @@ impl VariantMemberDescriptionFactory<'ll, 'tcx> { #[derive(Copy, Clone)] enum EnumDiscriminantInfo<'ll> { - RegularDiscriminant(&'ll DIType), + RegularDiscriminant{ discr_field: Field, discr_type_metadata: &'ll DIType }, OptimizedDiscriminant, NoDiscriminant } @@ -1547,11 +1554,14 @@ fn describe_enum_variant( let (offsets, args) = if use_enum_fallback(cx) { // If this is not a univariant enum, there is also the discriminant field. let (discr_offset, discr_arg) = match discriminant_info { - RegularDiscriminant(_) => { + RegularDiscriminant { discr_field, .. } => { // We have the layout of an enum variant, we need the layout of the outer enum let enum_layout = cx.layout_of(layout.ty); - (Some(enum_layout.fields.offset(0)), - Some(("RUST$ENUM$DISR".to_owned(), enum_layout.field(cx, 0).ty))) + let offset = enum_layout.fields.offset(discr_field.as_usize()); + let args = ( + "RUST$ENUM$DISR".to_owned(), + enum_layout.field(cx, discr_field.as_usize()).ty); + (Some(offset), Some(args)) } _ => (None, None), }; @@ -1579,8 +1589,8 @@ fn describe_enum_variant( offsets, args, discriminant_type_metadata: match discriminant_info { - RegularDiscriminant(discriminant_type_metadata) => { - Some(discriminant_type_metadata) + RegularDiscriminant { discr_type_metadata, .. } => { + Some(discr_type_metadata) } _ => None }, @@ -1730,6 +1740,7 @@ fn prepare_enum_metadata( layout::Variants::Multiple { discr_kind: layout::DiscriminantKind::Niche { .. }, ref discr, + discr_index, .. } => { // Find the integer type of the correct size. @@ -1753,7 +1764,7 @@ fn prepare_enum_metadata( UNKNOWN_LINE_NUMBER, size.bits(), align.abi.bits() as u32, - layout.fields.offset(0).bits(), + layout.fields.offset(discr_index).bits(), DIFlags::FlagArtificial, discr_metadata)) } @@ -1762,6 +1773,7 @@ fn prepare_enum_metadata( layout::Variants::Multiple { discr_kind: layout::DiscriminantKind::Tag, ref discr, + discr_index, .. } => { let discr_type = discr.value.to_ty(cx.tcx); @@ -1777,7 +1789,7 @@ fn prepare_enum_metadata( UNKNOWN_LINE_NUMBER, size.bits(), align.bits() as u32, - layout.fields.offset(0).bits(), + layout.fields.offset(discr_index).bits(), DIFlags::FlagArtificial, discr_metadata)) } diff --git a/src/librustc_codegen_llvm/type_of.rs b/src/librustc_codegen_llvm/type_of.rs index 020447608ee..d42fa829161 100644 --- a/src/librustc_codegen_llvm/type_of.rs +++ b/src/librustc_codegen_llvm/type_of.rs @@ -452,31 +452,27 @@ impl<'tcx> LayoutLlvmExt<'tcx> for TyLayout<'tcx> { _ => { let mut data_variant = match self.variants { + // Within the discriminant field, only the niche itself is + // always initialized, so we only check for a pointer at its + // offset. + // + // If the niche is a pointer, it's either valid (according + // to its type), or null (which the niche field's scalar + // validity range encodes). This allows using + // `dereferenceable_or_null` for e.g., `Option<&T>`, and + // this will continue to work as long as we don't start + // using more niches than just null (e.g., the first page of + // the address space, or unaligned pointers). layout::Variants::Multiple { discr_kind: layout::DiscriminantKind::Niche { dataful_variant, .. }, + discr_index, .. - } => { - // Only the niche itself is always initialized, - // so only check for a pointer at its offset. - // - // If the niche is a pointer, it's either valid - // (according to its type), or null (which the - // niche field's scalar validity range encodes). - // This allows using `dereferenceable_or_null` - // for e.g., `Option<&T>`, and this will continue - // to work as long as we don't start using more - // niches than just null (e.g., the first page - // of the address space, or unaligned pointers). - if self.fields.offset(0) == offset { - Some(self.for_variant(cx, dataful_variant)) - } else { - None - } - } - _ => Some(*self) + } if self.fields.offset(discr_index) == offset => + Some(self.for_variant(cx, dataful_variant)), + _ => Some(*self), }; if let Some(variant) = data_variant { |