diff options
Diffstat (limited to 'compiler/rustc_codegen_ssa/src/base.rs')
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/base.rs | 112 |
1 files changed, 68 insertions, 44 deletions
diff --git a/compiler/rustc_codegen_ssa/src/base.rs b/compiler/rustc_codegen_ssa/src/base.rs index b98ff4957..84b89cd71 100644 --- a/compiler/rustc_codegen_ssa/src/base.rs +++ b/compiler/rustc_codegen_ssa/src/base.rs @@ -39,7 +39,7 @@ use rustc_session::Session; use rustc_span::symbol::sym; use rustc_span::Symbol; use rustc_span::{DebuggerVisualizerFile, DebuggerVisualizerType}; -use rustc_target::abi::{Align, VariantIdx}; +use rustc_target::abi::{Align, Size, VariantIdx}; use std::collections::BTreeSet; use std::convert::TryFrom; @@ -151,7 +151,12 @@ pub fn unsized_info<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( (&ty::Array(_, len), &ty::Slice(_)) => { cx.const_usize(len.eval_usize(cx.tcx(), ty::ParamEnv::reveal_all())) } - (&ty::Dynamic(ref data_a, ..), &ty::Dynamic(ref data_b, ..)) => { + ( + &ty::Dynamic(ref data_a, _, src_dyn_kind), + &ty::Dynamic(ref data_b, _, target_dyn_kind), + ) => { + assert_eq!(src_dyn_kind, target_dyn_kind); + let old_info = old_info.expect("unsized_info: missing old info for trait upcasting coercion"); if data_a.principal_def_id() == data_b.principal_def_id() { @@ -167,11 +172,7 @@ pub fn unsized_info<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( if let Some(entry_idx) = vptr_entry_idx { let ptr_ty = cx.type_i8p(); let ptr_align = cx.tcx().data_layout.pointer_align.abi; - let vtable_ptr_ty = cx.scalar_pair_element_backend_type( - cx.layout_of(cx.tcx().mk_mut_ptr(target)), - 1, - true, - ); + let vtable_ptr_ty = vtable_ptr_ty(cx, target, target_dyn_kind); let llvtable = bx.pointercast(old_info, bx.type_ptr_to(ptr_ty)); let gep = bx.inbounds_gep( ptr_ty, @@ -187,18 +188,32 @@ pub fn unsized_info<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( old_info } } - (_, &ty::Dynamic(ref data, ..)) => { - let vtable_ptr_ty = cx.scalar_pair_element_backend_type( - cx.layout_of(cx.tcx().mk_mut_ptr(target)), - 1, - true, - ); + (_, &ty::Dynamic(ref data, _, target_dyn_kind)) => { + let vtable_ptr_ty = vtable_ptr_ty(cx, target, target_dyn_kind); cx.const_ptrcast(meth::get_vtable(cx, source, data.principal()), vtable_ptr_ty) } _ => bug!("unsized_info: invalid unsizing {:?} -> {:?}", source, target), } } +// Returns the vtable pointer type of a `dyn` or `dyn*` type +fn vtable_ptr_ty<'tcx, Cx: CodegenMethods<'tcx>>( + cx: &Cx, + target: Ty<'tcx>, + kind: ty::DynKind, +) -> <Cx as BackendTypes>::Type { + cx.scalar_pair_element_backend_type( + cx.layout_of(match kind { + // vtable is the second field of `*mut dyn Trait` + ty::Dyn => cx.tcx().mk_mut_ptr(target), + // vtable is the second field of `dyn* Trait` + ty::DynStar => target, + }), + 1, + true, + ) +} + /// Coerces `src` to `dst_ty`. `src_ty` must be a pointer. pub fn unsize_ptr<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( bx: &mut Bx, @@ -248,6 +263,29 @@ pub fn unsize_ptr<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( } } +/// Coerces `src` to `dst_ty` which is guaranteed to be a `dyn*` type. +pub fn cast_to_dyn_star<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( + bx: &mut Bx, + src: Bx::Value, + src_ty_and_layout: TyAndLayout<'tcx>, + dst_ty: Ty<'tcx>, + old_info: Option<Bx::Value>, +) -> (Bx::Value, Bx::Value) { + debug!("cast_to_dyn_star: {:?} => {:?}", src_ty_and_layout.ty, dst_ty); + assert!( + matches!(dst_ty.kind(), ty::Dynamic(_, _, ty::DynStar)), + "destination type must be a dyn*" + ); + // FIXME(dyn-star): this is probably not the best way to check if this is + // a pointer, and really we should ensure that the value is a suitable + // pointer earlier in the compilation process. + let src = match src_ty_and_layout.pointee_info_at(bx.cx(), Size::ZERO) { + Some(_) => bx.ptrtoint(src, bx.cx().type_isize()), + None => bx.bitcast(src, bx.type_isize()), + }; + (src, unsized_info(bx, src_ty_and_layout.ty, dst_ty, old_info)) +} + /// Coerces `src`, which is a reference to a value of type `src_ty`, /// to a value of type `dst_ty`, and stores the result in `dst`. pub fn coerce_unsized_into<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( @@ -299,40 +337,26 @@ pub fn coerce_unsized_into<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( pub fn cast_shift_expr_rhs<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( bx: &mut Bx, - op: hir::BinOpKind, - lhs: Bx::Value, - rhs: Bx::Value, -) -> Bx::Value { - cast_shift_rhs(bx, op, lhs, rhs) -} - -fn cast_shift_rhs<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( - bx: &mut Bx, - op: hir::BinOpKind, lhs: Bx::Value, rhs: Bx::Value, ) -> Bx::Value { // Shifts may have any size int on the rhs - if op.is_shift() { - let mut rhs_llty = bx.cx().val_ty(rhs); - let mut lhs_llty = bx.cx().val_ty(lhs); - if bx.cx().type_kind(rhs_llty) == TypeKind::Vector { - rhs_llty = bx.cx().element_type(rhs_llty) - } - if bx.cx().type_kind(lhs_llty) == TypeKind::Vector { - lhs_llty = bx.cx().element_type(lhs_llty) - } - let rhs_sz = bx.cx().int_width(rhs_llty); - let lhs_sz = bx.cx().int_width(lhs_llty); - if lhs_sz < rhs_sz { - bx.trunc(rhs, lhs_llty) - } else if lhs_sz > rhs_sz { - // FIXME (#1877: If in the future shifting by negative - // values is no longer undefined then this is wrong. - bx.zext(rhs, lhs_llty) - } else { - rhs - } + let mut rhs_llty = bx.cx().val_ty(rhs); + let mut lhs_llty = bx.cx().val_ty(lhs); + if bx.cx().type_kind(rhs_llty) == TypeKind::Vector { + rhs_llty = bx.cx().element_type(rhs_llty) + } + if bx.cx().type_kind(lhs_llty) == TypeKind::Vector { + lhs_llty = bx.cx().element_type(lhs_llty) + } + let rhs_sz = bx.cx().int_width(rhs_llty); + let lhs_sz = bx.cx().int_width(lhs_llty); + if lhs_sz < rhs_sz { + bx.trunc(rhs, lhs_llty) + } else if lhs_sz > rhs_sz { + // FIXME (#1877: If in the future shifting by negative + // values is no longer undefined then this is wrong. + bx.zext(rhs, lhs_llty) } else { rhs } @@ -475,7 +499,7 @@ pub fn maybe_create_entry_wrapper<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>( (rust_main, start_ty, vec![arg_argc, arg_argv]) }; - let result = bx.call(start_ty, start_fn, &args, None); + let result = bx.call(start_ty, None, start_fn, &args, None); let cast = bx.intcast(result, cx.type_int(), true); bx.ret(cast); |