diff options
| -rw-r--r-- | src/librustc_codegen_llvm/abi.rs | 5 | ||||
| -rw-r--r-- | src/librustc_codegen_llvm/mir/block.rs | 8 |
2 files changed, 11 insertions, 2 deletions
diff --git a/src/librustc_codegen_llvm/abi.rs b/src/librustc_codegen_llvm/abi.rs index 1662b57b8b3..e50534a4e1d 100644 --- a/src/librustc_codegen_llvm/abi.rs +++ b/src/librustc_codegen_llvm/abi.rs @@ -315,6 +315,11 @@ impl<'tcx> FnTypeExt<'tcx> for FnType<'tcx, Ty<'tcx>> { _ => bug!("receiver type has unsupported layout: {:?}", layout) } + // In the case of Rc<Self>, we need to explicitly pass a *mut RcBox<Self> + // with a Scalar (not ScalarPair) ABI. This is a hack that is understood + // elsewhere in the compiler as a method on a `dyn Trait`. + // To get the type `*mut RcBox<Self>`, we just keep unwrapping newtypes until we + // get a built-in pointer type let mut fat_pointer_layout = layout; 'descend_newtypes: while !fat_pointer_layout.ty.is_unsafe_ptr() && !fat_pointer_layout.ty.is_region_ptr() diff --git a/src/librustc_codegen_llvm/mir/block.rs b/src/librustc_codegen_llvm/mir/block.rs index 0cb4963f97f..a7f4c48c89b 100644 --- a/src/librustc_codegen_llvm/mir/block.rs +++ b/src/librustc_codegen_llvm/mir/block.rs @@ -647,8 +647,12 @@ impl FunctionCx<'a, 'll, 'tcx> { if let (0, Some(ty::InstanceDef::Virtual(_, idx))) = (i, def) { if let Pair(..) = op.val { - // descend through newtype wrappers until `op` is a builtin pointer to - // `dyn Trait`, e.g. `*const dyn Trait`, `&mut dyn Trait` + // In the case of Rc<Self>, we need to explicitly pass a + // *mut RcBox<Self> with a Scalar (not ScalarPair) ABI. This is a hack + // that is understood elsewhere in the compiler as a method on + // `dyn Trait`. + // To get a `*mut RcBox<Self>`, we just keep unwrapping newtypes until + // we get a value of a built-in pointer type 'descend_newtypes: while !op.layout.ty.is_unsafe_ptr() && !op.layout.ty.is_region_ptr() { |