| //! Definition of [`CValue`] and [`CPlace`] |
| |
| use crate::prelude::*; |
| |
| use cranelift_codegen::ir::immediates::Offset32; |
| |
| fn codegen_field<'tcx>( |
| fx: &mut FunctionCx<'_, '_, 'tcx>, |
| base: Pointer, |
| extra: Option<Value>, |
| layout: TyAndLayout<'tcx>, |
| field: mir::Field, |
| ) -> (Pointer, TyAndLayout<'tcx>) { |
| let field_offset = layout.fields.offset(field.index()); |
| let field_layout = layout.field(&*fx, field.index()); |
| |
| let simple = |fx: &mut FunctionCx<'_, '_, '_>| { |
| (base.offset_i64(fx, i64::try_from(field_offset.bytes()).unwrap()), field_layout) |
| }; |
| |
| if let Some(extra) = extra { |
| if !field_layout.is_unsized() { |
| return simple(fx); |
| } |
| match field_layout.ty.kind() { |
| ty::Slice(..) | ty::Str | ty::Foreign(..) => simple(fx), |
| ty::Adt(def, _) if def.repr.packed() => { |
| assert_eq!(layout.align.abi.bytes(), 1); |
| simple(fx) |
| } |
| _ => { |
| // We have to align the offset for DST's |
| let unaligned_offset = field_offset.bytes(); |
| let (_, unsized_align) = |
| crate::unsize::size_and_align_of_dst(fx, field_layout, extra); |
| |
| let one = fx.bcx.ins().iconst(pointer_ty(fx.tcx), 1); |
| let align_sub_1 = fx.bcx.ins().isub(unsized_align, one); |
| let and_lhs = fx.bcx.ins().iadd_imm(align_sub_1, unaligned_offset as i64); |
| let zero = fx.bcx.ins().iconst(pointer_ty(fx.tcx), 0); |
| let and_rhs = fx.bcx.ins().isub(zero, unsized_align); |
| let offset = fx.bcx.ins().band(and_lhs, and_rhs); |
| |
| (base.offset_value(fx, offset), field_layout) |
| } |
| } |
| } else { |
| simple(fx) |
| } |
| } |
| |
| fn scalar_pair_calculate_b_offset( |
| tcx: TyCtxt<'_>, |
| a_scalar: &Scalar, |
| b_scalar: &Scalar, |
| ) -> Offset32 { |
| let b_offset = a_scalar.value.size(&tcx).align_to(b_scalar.value.align(&tcx).abi); |
| Offset32::new(b_offset.bytes().try_into().unwrap()) |
| } |
| |
| /// A read-only value |
| #[derive(Debug, Copy, Clone)] |
| pub(crate) struct CValue<'tcx>(CValueInner, TyAndLayout<'tcx>); |
| |
| #[derive(Debug, Copy, Clone)] |
| enum CValueInner { |
| ByRef(Pointer, Option<Value>), |
| ByVal(Value), |
| ByValPair(Value, Value), |
| } |
| |
| impl<'tcx> CValue<'tcx> { |
| pub(crate) fn by_ref(ptr: Pointer, layout: TyAndLayout<'tcx>) -> CValue<'tcx> { |
| CValue(CValueInner::ByRef(ptr, None), layout) |
| } |
| |
| pub(crate) fn by_ref_unsized( |
| ptr: Pointer, |
| meta: Value, |
| layout: TyAndLayout<'tcx>, |
| ) -> CValue<'tcx> { |
| CValue(CValueInner::ByRef(ptr, Some(meta)), layout) |
| } |
| |
| pub(crate) fn by_val(value: Value, layout: TyAndLayout<'tcx>) -> CValue<'tcx> { |
| CValue(CValueInner::ByVal(value), layout) |
| } |
| |
| pub(crate) fn by_val_pair( |
| value: Value, |
| extra: Value, |
| layout: TyAndLayout<'tcx>, |
| ) -> CValue<'tcx> { |
| CValue(CValueInner::ByValPair(value, extra), layout) |
| } |
| |
| pub(crate) fn layout(&self) -> TyAndLayout<'tcx> { |
| self.1 |
| } |
| |
| // FIXME remove |
| pub(crate) fn force_stack(self, fx: &mut FunctionCx<'_, '_, 'tcx>) -> (Pointer, Option<Value>) { |
| let layout = self.1; |
| match self.0 { |
| CValueInner::ByRef(ptr, meta) => (ptr, meta), |
| CValueInner::ByVal(_) | CValueInner::ByValPair(_, _) => { |
| let cplace = CPlace::new_stack_slot(fx, layout); |
| cplace.write_cvalue(fx, self); |
| (cplace.to_ptr(), None) |
| } |
| } |
| } |
| |
| pub(crate) fn try_to_ptr(self) -> Option<(Pointer, Option<Value>)> { |
| match self.0 { |
| CValueInner::ByRef(ptr, meta) => Some((ptr, meta)), |
| CValueInner::ByVal(_) | CValueInner::ByValPair(_, _) => None, |
| } |
| } |
| |
| /// Load a value with layout.abi of scalar |
| pub(crate) fn load_scalar(self, fx: &mut FunctionCx<'_, '_, 'tcx>) -> Value { |
| let layout = self.1; |
| match self.0 { |
| CValueInner::ByRef(ptr, None) => { |
| let clif_ty = match layout.abi { |
| Abi::Scalar(ref scalar) => scalar_to_clif_type(fx.tcx, scalar.clone()), |
| Abi::Vector { ref element, count } => { |
| scalar_to_clif_type(fx.tcx, element.clone()) |
| .by(u16::try_from(count).unwrap()) |
| .unwrap() |
| } |
| _ => unreachable!("{:?}", layout.ty), |
| }; |
| let mut flags = MemFlags::new(); |
| flags.set_notrap(); |
| ptr.load(fx, clif_ty, flags) |
| } |
| CValueInner::ByVal(value) => value, |
| CValueInner::ByRef(_, Some(_)) => bug!("load_scalar for unsized value not allowed"), |
| CValueInner::ByValPair(_, _) => bug!("Please use load_scalar_pair for ByValPair"), |
| } |
| } |
| |
| /// Load a value pair with layout.abi of scalar pair |
| pub(crate) fn load_scalar_pair(self, fx: &mut FunctionCx<'_, '_, 'tcx>) -> (Value, Value) { |
| let layout = self.1; |
| match self.0 { |
| CValueInner::ByRef(ptr, None) => { |
| let (a_scalar, b_scalar) = match &layout.abi { |
| Abi::ScalarPair(a, b) => (a, b), |
| _ => unreachable!("load_scalar_pair({:?})", self), |
| }; |
| let b_offset = scalar_pair_calculate_b_offset(fx.tcx, a_scalar, b_scalar); |
| let clif_ty1 = scalar_to_clif_type(fx.tcx, a_scalar.clone()); |
| let clif_ty2 = scalar_to_clif_type(fx.tcx, b_scalar.clone()); |
| let mut flags = MemFlags::new(); |
| flags.set_notrap(); |
| let val1 = ptr.load(fx, clif_ty1, flags); |
| let val2 = ptr.offset(fx, b_offset).load(fx, clif_ty2, flags); |
| (val1, val2) |
| } |
| CValueInner::ByRef(_, Some(_)) => { |
| bug!("load_scalar_pair for unsized value not allowed") |
| } |
| CValueInner::ByVal(_) => bug!("Please use load_scalar for ByVal"), |
| CValueInner::ByValPair(val1, val2) => (val1, val2), |
| } |
| } |
| |
| pub(crate) fn value_field( |
| self, |
| fx: &mut FunctionCx<'_, '_, 'tcx>, |
| field: mir::Field, |
| ) -> CValue<'tcx> { |
| let layout = self.1; |
| match self.0 { |
| CValueInner::ByVal(val) => match layout.abi { |
| Abi::Vector { element: _, count } => { |
| let count = u8::try_from(count).expect("SIMD type with more than 255 lanes???"); |
| let field = u8::try_from(field.index()).unwrap(); |
| assert!(field < count); |
| let lane = fx.bcx.ins().extractlane(val, field); |
| let field_layout = layout.field(&*fx, usize::from(field)); |
| CValue::by_val(lane, field_layout) |
| } |
| _ => unreachable!("value_field for ByVal with abi {:?}", layout.abi), |
| }, |
| CValueInner::ByValPair(val1, val2) => match layout.abi { |
| Abi::ScalarPair(_, _) => { |
| let val = match field.as_u32() { |
| 0 => val1, |
| 1 => val2, |
| _ => bug!("field should be 0 or 1"), |
| }; |
| let field_layout = layout.field(&*fx, usize::from(field)); |
| CValue::by_val(val, field_layout) |
| } |
| _ => unreachable!("value_field for ByValPair with abi {:?}", layout.abi), |
| }, |
| CValueInner::ByRef(ptr, None) => { |
| let (field_ptr, field_layout) = codegen_field(fx, ptr, None, layout, field); |
| CValue::by_ref(field_ptr, field_layout) |
| } |
| CValueInner::ByRef(_, Some(_)) => todo!(), |
| } |
| } |
| |
| pub(crate) fn unsize_value(self, fx: &mut FunctionCx<'_, '_, 'tcx>, dest: CPlace<'tcx>) { |
| crate::unsize::coerce_unsized_into(fx, self, dest); |
| } |
| |
| /// If `ty` is signed, `const_val` must already be sign extended. |
| pub(crate) fn const_val( |
| fx: &mut FunctionCx<'_, '_, 'tcx>, |
| layout: TyAndLayout<'tcx>, |
| const_val: ty::ScalarInt, |
| ) -> CValue<'tcx> { |
| assert_eq!(const_val.size(), layout.size, "{:#?}: {:?}", const_val, layout); |
| use cranelift_codegen::ir::immediates::{Ieee32, Ieee64}; |
| |
| let clif_ty = fx.clif_type(layout.ty).unwrap(); |
| |
| if let ty::Bool = layout.ty.kind() { |
| assert!( |
| const_val == ty::ScalarInt::FALSE || const_val == ty::ScalarInt::TRUE, |
| "Invalid bool 0x{:032X}", |
| const_val |
| ); |
| } |
| |
| let val = match layout.ty.kind() { |
| ty::Uint(UintTy::U128) | ty::Int(IntTy::I128) => { |
| let const_val = const_val.to_bits(layout.size).unwrap(); |
| let lsb = fx.bcx.ins().iconst(types::I64, const_val as u64 as i64); |
| let msb = fx.bcx.ins().iconst(types::I64, (const_val >> 64) as u64 as i64); |
| fx.bcx.ins().iconcat(lsb, msb) |
| } |
| ty::Bool | ty::Char | ty::Uint(_) | ty::Int(_) | ty::Ref(..) | ty::RawPtr(..) => { |
| fx.bcx.ins().iconst(clif_ty, const_val.to_bits(layout.size).unwrap() as i64) |
| } |
| ty::Float(FloatTy::F32) => { |
| fx.bcx.ins().f32const(Ieee32::with_bits(u32::try_from(const_val).unwrap())) |
| } |
| ty::Float(FloatTy::F64) => { |
| fx.bcx.ins().f64const(Ieee64::with_bits(u64::try_from(const_val).unwrap())) |
| } |
| _ => panic!( |
| "CValue::const_val for non bool/char/float/integer/pointer type {:?} is not allowed", |
| layout.ty |
| ), |
| }; |
| |
| CValue::by_val(val, layout) |
| } |
| |
| pub(crate) fn cast_pointer_to(self, layout: TyAndLayout<'tcx>) -> Self { |
| assert!(matches!(self.layout().ty.kind(), ty::Ref(..) | ty::RawPtr(..) | ty::FnPtr(..))); |
| assert!(matches!(layout.ty.kind(), ty::Ref(..) | ty::RawPtr(..) | ty::FnPtr(..))); |
| assert_eq!(self.layout().abi, layout.abi); |
| CValue(self.0, layout) |
| } |
| } |
| |
| /// A place where you can write a value to or read a value from |
| #[derive(Debug, Copy, Clone)] |
| pub(crate) struct CPlace<'tcx> { |
| inner: CPlaceInner, |
| layout: TyAndLayout<'tcx>, |
| } |
| |
| #[derive(Debug, Copy, Clone)] |
| pub(crate) enum CPlaceInner { |
| Var(Local, Variable), |
| VarPair(Local, Variable, Variable), |
| VarLane(Local, Variable, u8), |
| Addr(Pointer, Option<Value>), |
| } |
| |
| impl<'tcx> CPlace<'tcx> { |
| pub(crate) fn layout(&self) -> TyAndLayout<'tcx> { |
| self.layout |
| } |
| |
| pub(crate) fn inner(&self) -> &CPlaceInner { |
| &self.inner |
| } |
| |
| pub(crate) fn no_place(layout: TyAndLayout<'tcx>) -> CPlace<'tcx> { |
| CPlace { inner: CPlaceInner::Addr(Pointer::dangling(layout.align.pref), None), layout } |
| } |
| |
| pub(crate) fn new_stack_slot( |
| fx: &mut FunctionCx<'_, '_, 'tcx>, |
| layout: TyAndLayout<'tcx>, |
| ) -> CPlace<'tcx> { |
| assert!(!layout.is_unsized()); |
| if layout.size.bytes() == 0 { |
| return CPlace::no_place(layout); |
| } |
| |
| let stack_slot = fx.bcx.create_stack_slot(StackSlotData { |
| kind: StackSlotKind::ExplicitSlot, |
| // FIXME Don't force the size to a multiple of 16 bytes once Cranelift gets a way to |
| // specify stack slot alignment. |
| size: (u32::try_from(layout.size.bytes()).unwrap() + 15) / 16 * 16, |
| offset: None, |
| }); |
| CPlace { inner: CPlaceInner::Addr(Pointer::stack_slot(stack_slot), None), layout } |
| } |
| |
| pub(crate) fn new_var( |
| fx: &mut FunctionCx<'_, '_, 'tcx>, |
| local: Local, |
| layout: TyAndLayout<'tcx>, |
| ) -> CPlace<'tcx> { |
| let var = Variable::with_u32(fx.next_ssa_var); |
| fx.next_ssa_var += 1; |
| fx.bcx.declare_var(var, fx.clif_type(layout.ty).unwrap()); |
| CPlace { inner: CPlaceInner::Var(local, var), layout } |
| } |
| |
| pub(crate) fn new_var_pair( |
| fx: &mut FunctionCx<'_, '_, 'tcx>, |
| local: Local, |
| layout: TyAndLayout<'tcx>, |
| ) -> CPlace<'tcx> { |
| let var1 = Variable::with_u32(fx.next_ssa_var); |
| fx.next_ssa_var += 1; |
| let var2 = Variable::with_u32(fx.next_ssa_var); |
| fx.next_ssa_var += 1; |
| |
| let (ty1, ty2) = fx.clif_pair_type(layout.ty).unwrap(); |
| fx.bcx.declare_var(var1, ty1); |
| fx.bcx.declare_var(var2, ty2); |
| CPlace { inner: CPlaceInner::VarPair(local, var1, var2), layout } |
| } |
| |
| pub(crate) fn for_ptr(ptr: Pointer, layout: TyAndLayout<'tcx>) -> CPlace<'tcx> { |
| CPlace { inner: CPlaceInner::Addr(ptr, None), layout } |
| } |
| |
| pub(crate) fn for_ptr_with_extra( |
| ptr: Pointer, |
| extra: Value, |
| layout: TyAndLayout<'tcx>, |
| ) -> CPlace<'tcx> { |
| CPlace { inner: CPlaceInner::Addr(ptr, Some(extra)), layout } |
| } |
| |
| pub(crate) fn to_cvalue(self, fx: &mut FunctionCx<'_, '_, 'tcx>) -> CValue<'tcx> { |
| let layout = self.layout(); |
| match self.inner { |
| CPlaceInner::Var(_local, var) => { |
| let val = fx.bcx.use_var(var); |
| //fx.bcx.set_val_label(val, cranelift_codegen::ir::ValueLabel::new(var.index())); |
| CValue::by_val(val, layout) |
| } |
| CPlaceInner::VarPair(_local, var1, var2) => { |
| let val1 = fx.bcx.use_var(var1); |
| //fx.bcx.set_val_label(val1, cranelift_codegen::ir::ValueLabel::new(var1.index())); |
| let val2 = fx.bcx.use_var(var2); |
| //fx.bcx.set_val_label(val2, cranelift_codegen::ir::ValueLabel::new(var2.index())); |
| CValue::by_val_pair(val1, val2, layout) |
| } |
| CPlaceInner::VarLane(_local, var, lane) => { |
| let val = fx.bcx.use_var(var); |
| //fx.bcx.set_val_label(val, cranelift_codegen::ir::ValueLabel::new(var.index())); |
| let val = fx.bcx.ins().extractlane(val, lane); |
| CValue::by_val(val, layout) |
| } |
| CPlaceInner::Addr(ptr, extra) => { |
| if let Some(extra) = extra { |
| CValue::by_ref_unsized(ptr, extra, layout) |
| } else { |
| CValue::by_ref(ptr, layout) |
| } |
| } |
| } |
| } |
| |
| pub(crate) fn to_ptr(self) -> Pointer { |
| match self.to_ptr_maybe_unsized() { |
| (ptr, None) => ptr, |
| (_, Some(_)) => bug!("Expected sized cplace, found {:?}", self), |
| } |
| } |
| |
| pub(crate) fn to_ptr_maybe_unsized(self) -> (Pointer, Option<Value>) { |
| match self.inner { |
| CPlaceInner::Addr(ptr, extra) => (ptr, extra), |
| CPlaceInner::Var(_, _) |
| | CPlaceInner::VarPair(_, _, _) |
| | CPlaceInner::VarLane(_, _, _) => bug!("Expected CPlace::Addr, found {:?}", self), |
| } |
| } |
| |
| pub(crate) fn write_cvalue(self, fx: &mut FunctionCx<'_, '_, 'tcx>, from: CValue<'tcx>) { |
| assert_assignable(fx, from.layout().ty, self.layout().ty); |
| |
| self.write_cvalue_maybe_transmute(fx, from, "write_cvalue"); |
| } |
| |
| pub(crate) fn write_cvalue_transmute( |
| self, |
| fx: &mut FunctionCx<'_, '_, 'tcx>, |
| from: CValue<'tcx>, |
| ) { |
| self.write_cvalue_maybe_transmute(fx, from, "write_cvalue_transmute"); |
| } |
| |
| fn write_cvalue_maybe_transmute( |
| self, |
| fx: &mut FunctionCx<'_, '_, 'tcx>, |
| from: CValue<'tcx>, |
| method: &'static str, |
| ) { |
| fn transmute_value<'tcx>( |
| fx: &mut FunctionCx<'_, '_, 'tcx>, |
| var: Variable, |
| data: Value, |
| dst_ty: Type, |
| ) { |
| let src_ty = fx.bcx.func.dfg.value_type(data); |
| assert_eq!( |
| src_ty.bytes(), |
| dst_ty.bytes(), |
| "write_cvalue_transmute: {:?} -> {:?}", |
| src_ty, |
| dst_ty, |
| ); |
| let data = match (src_ty, dst_ty) { |
| (_, _) if src_ty == dst_ty => data, |
| |
| // This is a `write_cvalue_transmute`. |
| (types::I32, types::F32) |
| | (types::F32, types::I32) |
| | (types::I64, types::F64) |
| | (types::F64, types::I64) => fx.bcx.ins().bitcast(dst_ty, data), |
| _ if src_ty.is_vector() && dst_ty.is_vector() => { |
| fx.bcx.ins().raw_bitcast(dst_ty, data) |
| } |
| _ if src_ty.is_vector() || dst_ty.is_vector() => { |
| // FIXME do something more efficient for transmutes between vectors and integers. |
| let stack_slot = fx.bcx.create_stack_slot(StackSlotData { |
| kind: StackSlotKind::ExplicitSlot, |
| // FIXME Don't force the size to a multiple of 16 bytes once Cranelift gets a way to |
| // specify stack slot alignment. |
| size: (src_ty.bytes() + 15) / 16 * 16, |
| offset: None, |
| }); |
| let ptr = Pointer::stack_slot(stack_slot); |
| ptr.store(fx, data, MemFlags::trusted()); |
| ptr.load(fx, dst_ty, MemFlags::trusted()) |
| } |
| _ => unreachable!("write_cvalue_transmute: {:?} -> {:?}", src_ty, dst_ty), |
| }; |
| //fx.bcx.set_val_label(data, cranelift_codegen::ir::ValueLabel::new(var.index())); |
| fx.bcx.def_var(var, data); |
| } |
| |
| assert_eq!(self.layout().size, from.layout().size); |
| |
| if fx.clif_comments.enabled() { |
| use cranelift_codegen::cursor::{Cursor, CursorPosition}; |
| let cur_block = match fx.bcx.cursor().position() { |
| CursorPosition::After(block) => block, |
| _ => unreachable!(), |
| }; |
| fx.add_comment( |
| fx.bcx.func.layout.last_inst(cur_block).unwrap(), |
| format!( |
| "{}: {:?}: {:?} <- {:?}: {:?}", |
| method, |
| self.inner(), |
| self.layout().ty, |
| from.0, |
| from.layout().ty |
| ), |
| ); |
| } |
| |
| let dst_layout = self.layout(); |
| let to_ptr = match self.inner { |
| CPlaceInner::Var(_local, var) => { |
| let data = CValue(from.0, dst_layout).load_scalar(fx); |
| let dst_ty = fx.clif_type(self.layout().ty).unwrap(); |
| transmute_value(fx, var, data, dst_ty); |
| return; |
| } |
| CPlaceInner::VarPair(_local, var1, var2) => { |
| let (data1, data2) = CValue(from.0, dst_layout).load_scalar_pair(fx); |
| let (dst_ty1, dst_ty2) = fx.clif_pair_type(self.layout().ty).unwrap(); |
| transmute_value(fx, var1, data1, dst_ty1); |
| transmute_value(fx, var2, data2, dst_ty2); |
| return; |
| } |
| CPlaceInner::VarLane(_local, var, lane) => { |
| let data = from.load_scalar(fx); |
| |
| // First get the old vector |
| let vector = fx.bcx.use_var(var); |
| //fx.bcx.set_val_label(vector, cranelift_codegen::ir::ValueLabel::new(var.index())); |
| |
| // Next insert the written lane into the vector |
| let vector = fx.bcx.ins().insertlane(vector, data, lane); |
| |
| // Finally write the new vector |
| //fx.bcx.set_val_label(vector, cranelift_codegen::ir::ValueLabel::new(var.index())); |
| fx.bcx.def_var(var, vector); |
| |
| return; |
| } |
| CPlaceInner::Addr(ptr, None) => { |
| if dst_layout.size == Size::ZERO || dst_layout.abi == Abi::Uninhabited { |
| return; |
| } |
| ptr |
| } |
| CPlaceInner::Addr(_, Some(_)) => bug!("Can't write value to unsized place {:?}", self), |
| }; |
| |
| let mut flags = MemFlags::new(); |
| flags.set_notrap(); |
| match from.layout().abi { |
| // FIXME make Abi::Vector work too |
| Abi::Scalar(_) => { |
| let val = from.load_scalar(fx); |
| to_ptr.store(fx, val, flags); |
| return; |
| } |
| Abi::ScalarPair(ref a_scalar, ref b_scalar) => { |
| let (value, extra) = from.load_scalar_pair(fx); |
| let b_offset = scalar_pair_calculate_b_offset(fx.tcx, a_scalar, b_scalar); |
| to_ptr.store(fx, value, flags); |
| to_ptr.offset(fx, b_offset).store(fx, extra, flags); |
| return; |
| } |
| _ => {} |
| } |
| |
| match from.0 { |
| CValueInner::ByVal(val) => { |
| to_ptr.store(fx, val, flags); |
| } |
| CValueInner::ByValPair(_, _) => { |
| bug!("Non ScalarPair abi {:?} for ByValPair CValue", dst_layout.abi); |
| } |
| CValueInner::ByRef(from_ptr, None) => { |
| let from_addr = from_ptr.get_addr(fx); |
| let to_addr = to_ptr.get_addr(fx); |
| let src_layout = from.1; |
| let size = dst_layout.size.bytes(); |
| let src_align = src_layout.align.abi.bytes() as u8; |
| let dst_align = dst_layout.align.abi.bytes() as u8; |
| fx.bcx.emit_small_memory_copy( |
| fx.cx.module.target_config(), |
| to_addr, |
| from_addr, |
| size, |
| dst_align, |
| src_align, |
| true, |
| ); |
| } |
| CValueInner::ByRef(_, Some(_)) => todo!(), |
| } |
| } |
| |
| pub(crate) fn place_field( |
| self, |
| fx: &mut FunctionCx<'_, '_, 'tcx>, |
| field: mir::Field, |
| ) -> CPlace<'tcx> { |
| let layout = self.layout(); |
| |
| match self.inner { |
| CPlaceInner::Var(local, var) => { |
| if let Abi::Vector { .. } = layout.abi { |
| return CPlace { |
| inner: CPlaceInner::VarLane(local, var, field.as_u32().try_into().unwrap()), |
| layout: layout.field(fx, field.as_u32().try_into().unwrap()), |
| }; |
| } |
| } |
| CPlaceInner::VarPair(local, var1, var2) => { |
| let layout = layout.field(&*fx, field.index()); |
| |
| match field.as_u32() { |
| 0 => return CPlace { inner: CPlaceInner::Var(local, var1), layout }, |
| 1 => return CPlace { inner: CPlaceInner::Var(local, var2), layout }, |
| _ => unreachable!("field should be 0 or 1"), |
| } |
| } |
| _ => {} |
| } |
| |
| let (base, extra) = self.to_ptr_maybe_unsized(); |
| |
| let (field_ptr, field_layout) = codegen_field(fx, base, extra, layout, field); |
| if field_layout.is_unsized() { |
| CPlace::for_ptr_with_extra(field_ptr, extra.unwrap(), field_layout) |
| } else { |
| CPlace::for_ptr(field_ptr, field_layout) |
| } |
| } |
| |
| pub(crate) fn place_index( |
| self, |
| fx: &mut FunctionCx<'_, '_, 'tcx>, |
| index: Value, |
| ) -> CPlace<'tcx> { |
| let (elem_layout, ptr) = match self.layout().ty.kind() { |
| ty::Array(elem_ty, _) => (fx.layout_of(elem_ty), self.to_ptr()), |
| ty::Slice(elem_ty) => (fx.layout_of(elem_ty), self.to_ptr_maybe_unsized().0), |
| _ => bug!("place_index({:?})", self.layout().ty), |
| }; |
| |
| let offset = fx.bcx.ins().imul_imm(index, elem_layout.size.bytes() as i64); |
| |
| CPlace::for_ptr(ptr.offset_value(fx, offset), elem_layout) |
| } |
| |
| pub(crate) fn place_deref(self, fx: &mut FunctionCx<'_, '_, 'tcx>) -> CPlace<'tcx> { |
| let inner_layout = fx.layout_of(self.layout().ty.builtin_deref(true).unwrap().ty); |
| if has_ptr_meta(fx.tcx, inner_layout.ty) { |
| let (addr, extra) = self.to_cvalue(fx).load_scalar_pair(fx); |
| CPlace::for_ptr_with_extra(Pointer::new(addr), extra, inner_layout) |
| } else { |
| CPlace::for_ptr(Pointer::new(self.to_cvalue(fx).load_scalar(fx)), inner_layout) |
| } |
| } |
| |
| pub(crate) fn place_ref( |
| self, |
| fx: &mut FunctionCx<'_, '_, 'tcx>, |
| layout: TyAndLayout<'tcx>, |
| ) -> CValue<'tcx> { |
| if has_ptr_meta(fx.tcx, self.layout().ty) { |
| let (ptr, extra) = self.to_ptr_maybe_unsized(); |
| CValue::by_val_pair( |
| ptr.get_addr(fx), |
| extra.expect("unsized type without metadata"), |
| layout, |
| ) |
| } else { |
| CValue::by_val(self.to_ptr().get_addr(fx), layout) |
| } |
| } |
| |
| pub(crate) fn downcast_variant( |
| self, |
| fx: &FunctionCx<'_, '_, 'tcx>, |
| variant: VariantIdx, |
| ) -> Self { |
| assert!(!self.layout().is_unsized()); |
| let layout = self.layout().for_variant(fx, variant); |
| CPlace { inner: self.inner, layout } |
| } |
| } |
| |
| #[track_caller] |
| pub(crate) fn assert_assignable<'tcx>( |
| fx: &FunctionCx<'_, '_, 'tcx>, |
| from_ty: Ty<'tcx>, |
| to_ty: Ty<'tcx>, |
| ) { |
| match (from_ty.kind(), to_ty.kind()) { |
| (ty::Ref(_, a, _), ty::Ref(_, b, _)) |
| | ( |
| ty::RawPtr(TypeAndMut { ty: a, mutbl: _ }), |
| ty::RawPtr(TypeAndMut { ty: b, mutbl: _ }), |
| ) => { |
| assert_assignable(fx, a, b); |
| } |
| (ty::Ref(_, a, _), ty::RawPtr(TypeAndMut { ty: b, mutbl: _ })) |
| | (ty::RawPtr(TypeAndMut { ty: a, mutbl: _ }), ty::Ref(_, b, _)) => { |
| assert_assignable(fx, a, b); |
| } |
| (ty::FnPtr(_), ty::FnPtr(_)) => { |
| let from_sig = fx.tcx.normalize_erasing_late_bound_regions( |
| ParamEnv::reveal_all(), |
| from_ty.fn_sig(fx.tcx), |
| ); |
| let to_sig = fx |
| .tcx |
| .normalize_erasing_late_bound_regions(ParamEnv::reveal_all(), to_ty.fn_sig(fx.tcx)); |
| assert_eq!( |
| from_sig, to_sig, |
| "Can't write fn ptr with incompatible sig {:?} to place with sig {:?}\n\n{:#?}", |
| from_sig, to_sig, fx, |
| ); |
| // fn(&T) -> for<'l> fn(&'l T) is allowed |
| } |
| (&ty::Dynamic(from_traits, _), &ty::Dynamic(to_traits, _)) => { |
| for (from, to) in from_traits.iter().zip(to_traits) { |
| let from = |
| fx.tcx.normalize_erasing_late_bound_regions(ParamEnv::reveal_all(), from); |
| let to = fx.tcx.normalize_erasing_late_bound_regions(ParamEnv::reveal_all(), to); |
| assert_eq!( |
| from, to, |
| "Can't write trait object of incompatible traits {:?} to place with traits {:?}\n\n{:#?}", |
| from_traits, to_traits, fx, |
| ); |
| } |
| // dyn for<'r> Trait<'r> -> dyn Trait<'_> is allowed |
| } |
| (&ty::Adt(adt_def_a, substs_a), &ty::Adt(adt_def_b, substs_b)) |
| if adt_def_a.did == adt_def_b.did => |
| { |
| let mut types_a = substs_a.types(); |
| let mut types_b = substs_b.types(); |
| loop { |
| match (types_a.next(), types_b.next()) { |
| (Some(a), Some(b)) => assert_assignable(fx, a, b), |
| (None, None) => return, |
| (Some(_), None) | (None, Some(_)) => panic!("{:#?}/{:#?}", from_ty, to_ty), |
| } |
| } |
| } |
| _ => { |
| assert_eq!( |
| from_ty, to_ty, |
| "Can't write value with incompatible type {:?} to place with type {:?}\n\n{:#?}", |
| from_ty, to_ty, fx, |
| ); |
| } |
| } |
| } |
