diff options
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/context.rs | 3 | ||||
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/type_of.rs | 2 |
2 files changed, 3 insertions, 2 deletions
diff --git a/compiler/rustc_codegen_llvm/src/context.rs b/compiler/rustc_codegen_llvm/src/context.rs index 52de4bcd737..b088b6e730b 100644 --- a/compiler/rustc_codegen_llvm/src/context.rs +++ b/compiler/rustc_codegen_llvm/src/context.rs @@ -80,8 +80,7 @@ pub struct CodegenCx<'ll, 'tcx> { pub isize_ty: &'ll Type, /// Cache for the mapping from source index to llvm index for struct fields, - /// necessary because the mapping depends on padding and thus depens on - /// TyAndLayout. + /// only present if synthetic fields are inserted for padding. pub field_projection_cache: RefCell<FxHashMap<TyAndLayout<'tcx>, Vec<u32>>>, pub coverage_cx: Option<coverageinfo::CrateCoverageContext<'ll, 'tcx>>, diff --git a/compiler/rustc_codegen_llvm/src/type_of.rs b/compiler/rustc_codegen_llvm/src/type_of.rs index da292756673..79bf51929e9 100644 --- a/compiler/rustc_codegen_llvm/src/type_of.rs +++ b/compiler/rustc_codegen_llvm/src/type_of.rs @@ -363,6 +363,8 @@ impl<'tcx> LayoutLlvmExt<'tcx> for TyAndLayout<'tcx> { FieldsShape::Array { .. } => index as u64, + // Look up llvm field index in projection cache if present. If no projection cache + // is present no padding is used and the llvm field index matches the memory index. FieldsShape::Arbitrary { .. } => match cx.field_projection_cache.borrow().get(self) { Some(projection) => projection[index] as u64, None => self.fields.memory_index(index) as u64, |