}
}
-fn scalar_to_clif_type(tcx: TyCtxt, scalar: &Scalar) -> Type {
- match scalar.value.size(&tcx).bits() {
- 8 => types::I8,
- 16 => types::I16,
- 32 => types::I32,
- 64 => types::I64,
- size => bug!("Unsupported scalar size {}", size),
- }
-}
-
pub fn clif_type_from_ty<'a, 'tcx: 'a>(
tcx: TyCtxt<'a, 'tcx, 'tcx>,
ty: Ty<'tcx>,
}
}
-fn codegen_field<'a, 'tcx: 'a>(
- fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
- base: Value,
- layout: TyLayout<'tcx>,
- field: mir::Field,
-) -> (Value, TyLayout<'tcx>) {
- let field_offset = layout.fields.offset(field.index());
- let field_ty = layout.field(&*fx, field.index());
- if field_offset.bytes() > 0 {
- (
- fx.bcx.ins().iadd_imm(base, field_offset.bytes() as i64),
- field_ty,
- )
- } else {
- (base, field_ty)
- }
-}
-
-/// A read-only value
-#[derive(Debug, Copy, Clone)]
-pub enum CValue<'tcx> {
- ByRef(Value, TyLayout<'tcx>),
- ByVal(Value, TyLayout<'tcx>),
- ByValPair(Value, Value, TyLayout<'tcx>),
-}
-
-impl<'tcx> CValue<'tcx> {
- pub fn by_ref(value: Value, layout: TyLayout<'tcx>) -> CValue<'tcx> {
- CValue::ByRef(value, layout)
- }
-
- pub fn by_val(value: Value, layout: TyLayout<'tcx>) -> CValue<'tcx> {
- CValue::ByVal(value, layout)
- }
-
- pub fn by_val_pair(value: Value, extra: Value, layout: TyLayout<'tcx>) -> CValue<'tcx> {
- CValue::ByValPair(value, extra, layout)
- }
-
- pub fn layout(&self) -> TyLayout<'tcx> {
- match *self {
- CValue::ByRef(_, layout)
- | CValue::ByVal(_, layout)
- | CValue::ByValPair(_, _, layout) => layout,
- }
- }
-
- pub fn force_stack<'a>(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>) -> Value
- where
- 'tcx: 'a,
- {
- match self {
- CValue::ByRef(value, _layout) => value,
- CValue::ByVal(value, layout) => {
- let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
- kind: StackSlotKind::ExplicitSlot,
- size: layout.size.bytes() as u32,
- offset: None,
- });
- let addr = fx.bcx.ins().stack_addr(fx.pointer_type, stack_slot, 0);
- fx.bcx.ins().store(MemFlags::new(), value, addr, 0);
- addr
- }
- CValue::ByValPair(value, extra, layout) => {
- let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
- kind: StackSlotKind::ExplicitSlot,
- size: layout.size.bytes() as u32,
- offset: None,
- });
- let base = fx.bcx.ins().stack_addr(types::I64, stack_slot, 0);
- let a_addr = codegen_field(fx, base, layout, mir::Field::new(0)).0;
- let b_addr = codegen_field(fx, base, layout, mir::Field::new(1)).0;
- fx.bcx.ins().store(MemFlags::new(), value, a_addr, 0);
- fx.bcx.ins().store(MemFlags::new(), extra, b_addr, 0);
- base
- }
- }
- }
-
- /// Load a value with layout.abi of scalar
- pub fn load_scalar<'a>(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>) -> Value
- where
- 'tcx: 'a,
- {
- match self {
- CValue::ByRef(addr, layout) => {
- let scalar = match layout.abi {
- layout::Abi::Scalar(ref scalar) => scalar.clone(),
- _ => unreachable!(),
- };
- let clif_ty = crate::abi::scalar_to_clif_type(fx.tcx, scalar);
- fx.bcx.ins().load(clif_ty, MemFlags::new(), addr, 0)
- }
- CValue::ByVal(value, _layout) => value,
- CValue::ByValPair(_, _, _layout) => bug!("Please use load_scalar_pair for ByValPair"),
- }
- }
-
- /// Load a value pair with layout.abi of scalar pair
- pub fn load_scalar_pair<'a>(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>) -> (Value, Value)
- where
- 'tcx: 'a,
- {
- match self {
- CValue::ByRef(addr, layout) => {
- let (a, b) = match &layout.abi {
- layout::Abi::ScalarPair(a, b) => (a.clone(), b.clone()),
- _ => unreachable!(),
- };
- let clif_ty1 = crate::abi::scalar_to_clif_type(fx.tcx, a.clone());
- let clif_ty2 = crate::abi::scalar_to_clif_type(fx.tcx, b);
- let val1 = fx.bcx.ins().load(clif_ty1, MemFlags::new(), addr, 0);
- let val2 = fx.bcx.ins().load(
- clif_ty2,
- MemFlags::new(),
- addr,
- a.value.size(&fx.tcx).bytes() as i32,
- );
- (val1, val2)
- }
- CValue::ByVal(_, _layout) => bug!("Please use load_scalar for ByVal"),
- CValue::ByValPair(val1, val2, _layout) => (val1, val2),
- }
- }
-
- pub fn value_field<'a>(
- self,
- fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
- field: mir::Field,
- ) -> CValue<'tcx>
- where
- 'tcx: 'a,
- {
- let (base, layout) = match self {
- CValue::ByRef(addr, layout) => (addr, layout),
- _ => bug!("place_field for {:?}", self),
- };
-
- let (field_ptr, field_layout) = codegen_field(fx, base, layout, field);
- CValue::ByRef(field_ptr, field_layout)
- }
-
- pub fn unsize_value<'a>(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>, dest: CPlace<'tcx>) {
- crate::unsize::coerce_unsized_into(fx, self, dest);
- }
-
- pub fn const_val<'a>(
- fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
- ty: Ty<'tcx>,
- const_val: i64,
- ) -> CValue<'tcx>
- where
- 'tcx: 'a,
- {
- let clif_ty = fx.clif_type(ty).unwrap();
- let layout = fx.layout_of(ty);
- CValue::ByVal(fx.bcx.ins().iconst(clif_ty, const_val), layout)
- }
-
- pub fn unchecked_cast_to(self, layout: TyLayout<'tcx>) -> Self {
- match self {
- CValue::ByRef(addr, _) => CValue::ByRef(addr, layout),
- CValue::ByVal(val, _) => CValue::ByVal(val, layout),
- CValue::ByValPair(val, extra, _) => CValue::ByValPair(val, extra, layout),
- }
- }
-}
-
-/// A place where you can write a value to or read a value from
-#[derive(Debug, Copy, Clone)]
-pub enum CPlace<'tcx> {
- Var(Local, TyLayout<'tcx>),
- Addr(Value, Option<Value>, TyLayout<'tcx>),
- Stack(StackSlot, TyLayout<'tcx>),
- NoPlace(TyLayout<'tcx>),
-}
-
-impl<'a, 'tcx: 'a> CPlace<'tcx> {
- pub fn layout(&self) -> TyLayout<'tcx> {
- match *self {
- CPlace::Var(_, layout)
- | CPlace::Addr(_, _, layout)
- | CPlace::Stack(_, layout)
- | CPlace::NoPlace(layout) => layout,
- }
- }
-
- pub fn no_place(layout: TyLayout<'tcx>) -> CPlace<'tcx> {
- CPlace::NoPlace(layout)
- }
-
- pub fn new_stack_slot(
- fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
- ty: Ty<'tcx>,
- ) -> CPlace<'tcx> {
- let layout = fx.layout_of(ty);
- assert!(!layout.is_unsized());
- if layout.size.bytes() == 0 {
- return CPlace::NoPlace(layout);
- }
-
- let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
- kind: StackSlotKind::ExplicitSlot,
- size: layout.size.bytes() as u32,
- offset: None,
- });
- CPlace::Stack(stack_slot, layout)
- }
-
- pub fn new_var(
- fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
- local: Local,
- layout: TyLayout<'tcx>,
- ) -> CPlace<'tcx> {
- fx.bcx
- .declare_var(mir_var(local), fx.clif_type(layout.ty).unwrap());
- CPlace::Var(local, layout)
- }
-
- pub fn to_cvalue(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>) -> CValue<'tcx> {
- match self {
- CPlace::Var(var, layout) => CValue::ByVal(fx.bcx.use_var(mir_var(var)), layout),
- CPlace::Addr(addr, extra, layout) => {
- assert!(extra.is_none(), "unsized values are not yet supported");
- CValue::ByRef(addr, layout)
- }
- CPlace::Stack(stack_slot, layout) => CValue::ByRef(
- fx.bcx.ins().stack_addr(fx.pointer_type, stack_slot, 0),
- layout,
- ),
- CPlace::NoPlace(layout) => CValue::ByRef(
- fx.bcx
- .ins()
- .iconst(fx.pointer_type, fx.pointer_type.bytes() as i64),
- layout,
- ),
- }
- }
-
- pub fn to_addr(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>) -> Value {
- match self.to_addr_maybe_unsized(fx) {
- (addr, None) => addr,
- (_, Some(_)) => bug!("Expected sized cplace, found {:?}", self),
- }
- }
-
- pub fn to_addr_maybe_unsized(
- self,
- fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
- ) -> (Value, Option<Value>) {
- match self {
- CPlace::Addr(addr, extra, _layout) => (addr, extra),
- CPlace::Stack(stack_slot, _layout) => (
- fx.bcx.ins().stack_addr(fx.pointer_type, stack_slot, 0),
- None,
- ),
- CPlace::NoPlace(_) => (fx.bcx.ins().iconst(fx.pointer_type, 45), None),
- CPlace::Var(_, _) => bug!("Expected CPlace::Addr, found CPlace::Var"),
- }
- }
-
- pub fn write_cvalue(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>, from: CValue<'tcx>) {
- use rustc::hir::Mutability::*;
-
- let from_ty = from.layout().ty;
- let to_ty = self.layout().ty;
-
- fn assert_assignable<'a, 'tcx: 'a>(fx: &FunctionCx<'a, 'tcx, impl Backend>, from_ty: Ty<'tcx>, to_ty: Ty<'tcx>) {
- match (&from_ty.sty, &to_ty.sty) {
- (ty::Ref(_, t, MutImmutable), ty::Ref(_, u, MutImmutable))
- | (ty::Ref(_, t, MutMutable), ty::Ref(_, u, MutImmutable))
- | (ty::Ref(_, t, MutMutable), ty::Ref(_, u, MutMutable)) => {
- assert_assignable(fx, t, u);
- // &mut T -> &T is allowed
- // &'a T -> &'b T is allowed
- }
- (ty::Ref(_, _, MutImmutable), ty::Ref(_, _, MutMutable)) => {
- panic!("Cant assign value of type {} to place of type {}", from_ty, to_ty)
- }
- (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, _)) => {
- let from_traits = fx.tcx.normalize_erasing_late_bound_regions(
- ParamEnv::reveal_all(),
- from_traits,
- );
- let to_traits = fx.tcx.normalize_erasing_late_bound_regions(
- ParamEnv::reveal_all(),
- to_traits,
- );
- assert_eq!(
- from_traits, to_traits,
- "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
- }
- _ => {
- assert_eq!(
- from_ty,
- to_ty,
- "Can't write value with incompatible type {:?} to place with type {:?}\n\n{:#?}",
- from_ty,
- to_ty,
- fx,
- );
- }
- }
- }
-
- assert_assignable(fx, from_ty, to_ty);
-
- let (addr, dst_layout) = match self {
- CPlace::Var(var, _) => {
- let data = from.load_scalar(fx);
- fx.bcx.def_var(mir_var(var), data);
- return;
- }
- CPlace::Addr(addr, None, dst_layout) => (addr, dst_layout),
- CPlace::Stack(stack_slot, dst_layout) => (
- fx.bcx.ins().stack_addr(fx.pointer_type, stack_slot, 0),
- dst_layout,
- ),
- CPlace::NoPlace(layout) => {
- assert_eq!(layout.size.bytes(), 0);
- assert_eq!(from.layout().size.bytes(), 0);
- return;
- }
- CPlace::Addr(_, _, _) => bug!("Can't write value to unsized place {:?}", self),
- };
-
- match from {
- CValue::ByVal(val, _src_layout) => {
- fx.bcx.ins().store(MemFlags::new(), val, addr, 0);
- }
- CValue::ByValPair(val1, val2, _src_layout) => {
- let val1_offset = dst_layout.fields.offset(0).bytes() as i32;
- let val2_offset = dst_layout.fields.offset(1).bytes() as i32;
- fx.bcx.ins().store(MemFlags::new(), val1, addr, val1_offset);
- fx.bcx.ins().store(MemFlags::new(), val2, addr, val2_offset);
- }
- CValue::ByRef(from, src_layout) => {
- 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_memcpy(
- fx.module.target_config(),
- addr,
- from,
- size,
- dst_align,
- src_align,
- );
- }
- }
- }
-
- pub fn place_field(
- self,
- fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
- field: mir::Field,
- ) -> CPlace<'tcx> {
- let layout = self.layout();
- let (base, extra) = self.to_addr_maybe_unsized(fx);
-
- let (field_ptr, field_layout) = codegen_field(fx, base, layout, field);
- let extra = if field_layout.is_unsized() {
- assert!(extra.is_some());
- extra
- } else {
- None
- };
- CPlace::Addr(field_ptr, extra, field_layout)
- }
-
- pub fn place_index(
- self,
- fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
- index: Value,
- ) -> CPlace<'tcx> {
- let (elem_layout, addr) = match self.layout().ty.sty {
- ty::Array(elem_ty, _) => (fx.layout_of(elem_ty), self.to_addr(fx)),
- ty::Slice(elem_ty) => (fx.layout_of(elem_ty), self.to_addr_maybe_unsized(fx).0),
- _ => bug!("place_index({:?})", self.layout().ty),
- };
-
- let offset = fx
- .bcx
- .ins()
- .imul_imm(index, elem_layout.size.bytes() as i64);
-
- CPlace::Addr(fx.bcx.ins().iadd(addr, offset), None, elem_layout)
- }
-
- pub fn place_deref(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>) -> CPlace<'tcx> {
- let inner_layout = fx.layout_of(self.layout().ty.builtin_deref(true).unwrap().ty);
- if !inner_layout.is_unsized() {
- CPlace::Addr(self.to_cvalue(fx).load_scalar(fx), None, inner_layout)
- } else {
- match self.layout().abi {
- Abi::ScalarPair(ref a, ref b) => {
- let addr = self.to_addr(fx);
- let ptr =
- fx.bcx
- .ins()
- .load(scalar_to_clif_type(fx.tcx, a), MemFlags::new(), addr, 0);
- let extra = fx.bcx.ins().load(
- scalar_to_clif_type(fx.tcx, b),
- MemFlags::new(),
- addr,
- a.value.size(&fx.tcx).bytes() as u32 as i32,
- );
- CPlace::Addr(ptr, Some(extra), inner_layout)
- }
- _ => bug!(
- "Fat ptr doesn't have abi ScalarPair, but it has {:?}",
- self.layout().abi
- ),
- }
- }
- }
-
- pub fn write_place_ref(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>, dest: CPlace<'tcx>) {
- if !self.layout().is_unsized() {
- let ptr = CValue::ByVal(self.to_addr(fx), dest.layout());
- dest.write_cvalue(fx, ptr);
- } else {
- let (value, extra) = self.to_addr_maybe_unsized(fx);
-
- match dest.layout().abi {
- Abi::ScalarPair(ref a, _) => {
- let dest_addr = dest.to_addr(fx);
- fx.bcx.ins().store(MemFlags::new(), value, dest_addr, 0);
- fx.bcx.ins().store(
- MemFlags::new(),
- extra.expect("unsized type without metadata"),
- dest_addr,
- a.value.size(&fx.tcx).bytes() as u32 as i32,
- );
- }
- _ => bug!(
- "Non ScalarPair abi {:?} in write_place_ref dest",
- dest.layout().abi
- ),
- }
- }
- }
-
- pub fn unchecked_cast_to(self, layout: TyLayout<'tcx>) -> Self {
- assert!(!self.layout().is_unsized());
- match self {
- CPlace::Var(var, _) => CPlace::Var(var, layout),
- CPlace::Addr(addr, extra, _) => CPlace::Addr(addr, extra, layout),
- CPlace::Stack(stack_slot, _) => CPlace::Stack(stack_slot, layout),
- CPlace::NoPlace(_) => {
- assert!(layout.size.bytes() == 0);
- CPlace::NoPlace(layout)
- }
- }
- }
-
- pub fn downcast_variant(
- self,
- fx: &FunctionCx<'a, 'tcx, impl Backend>,
- variant: VariantIdx,
- ) -> Self {
- let layout = self.layout().for_variant(fx, variant);
- self.unchecked_cast_to(layout)
- }
-}
-
pub fn clif_intcast<'a, 'tcx: 'a>(
fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
val: Value,
--- /dev/null
+use crate::prelude::*;
+
+fn codegen_field<'a, 'tcx: 'a>(
+ fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
+ base: Value,
+ layout: TyLayout<'tcx>,
+ field: mir::Field,
+) -> (Value, TyLayout<'tcx>) {
+ let field_offset = layout.fields.offset(field.index());
+ let field_ty = layout.field(&*fx, field.index());
+ if field_offset.bytes() > 0 {
+ (
+ fx.bcx.ins().iadd_imm(base, field_offset.bytes() as i64),
+ field_ty,
+ )
+ } else {
+ (base, field_ty)
+ }
+}
+
+/// A read-only value
+#[derive(Debug, Copy, Clone)]
+pub enum CValue<'tcx> {
+ ByRef(Value, TyLayout<'tcx>),
+ ByVal(Value, TyLayout<'tcx>),
+ ByValPair(Value, Value, TyLayout<'tcx>),
+}
+
+impl<'tcx> CValue<'tcx> {
+ pub fn by_ref(value: Value, layout: TyLayout<'tcx>) -> CValue<'tcx> {
+ CValue::ByRef(value, layout)
+ }
+
+ pub fn by_val(value: Value, layout: TyLayout<'tcx>) -> CValue<'tcx> {
+ CValue::ByVal(value, layout)
+ }
+
+ pub fn by_val_pair(value: Value, extra: Value, layout: TyLayout<'tcx>) -> CValue<'tcx> {
+ CValue::ByValPair(value, extra, layout)
+ }
+
+ pub fn layout(&self) -> TyLayout<'tcx> {
+ match *self {
+ CValue::ByRef(_, layout)
+ | CValue::ByVal(_, layout)
+ | CValue::ByValPair(_, _, layout) => layout,
+ }
+ }
+
+ pub fn force_stack<'a>(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>) -> Value
+ where
+ 'tcx: 'a,
+ {
+ match self {
+ CValue::ByRef(value, _layout) => value,
+ CValue::ByVal(value, layout) => {
+ let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
+ kind: StackSlotKind::ExplicitSlot,
+ size: layout.size.bytes() as u32,
+ offset: None,
+ });
+ let addr = fx.bcx.ins().stack_addr(fx.pointer_type, stack_slot, 0);
+ fx.bcx.ins().store(MemFlags::new(), value, addr, 0);
+ addr
+ }
+ CValue::ByValPair(value, extra, layout) => {
+ let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
+ kind: StackSlotKind::ExplicitSlot,
+ size: layout.size.bytes() as u32,
+ offset: None,
+ });
+ let base = fx.bcx.ins().stack_addr(types::I64, stack_slot, 0);
+ let a_addr = codegen_field(fx, base, layout, mir::Field::new(0)).0;
+ let b_addr = codegen_field(fx, base, layout, mir::Field::new(1)).0;
+ fx.bcx.ins().store(MemFlags::new(), value, a_addr, 0);
+ fx.bcx.ins().store(MemFlags::new(), extra, b_addr, 0);
+ base
+ }
+ }
+ }
+
+ /// Load a value with layout.abi of scalar
+ pub fn load_scalar<'a>(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>) -> Value
+ where
+ 'tcx: 'a,
+ {
+ match self {
+ CValue::ByRef(addr, layout) => {
+ let scalar = match layout.abi {
+ layout::Abi::Scalar(ref scalar) => scalar.clone(),
+ _ => unreachable!(),
+ };
+ let clif_ty = scalar_to_clif_type(fx.tcx, scalar);
+ fx.bcx.ins().load(clif_ty, MemFlags::new(), addr, 0)
+ }
+ CValue::ByVal(value, _layout) => value,
+ CValue::ByValPair(_, _, _layout) => bug!("Please use load_scalar_pair for ByValPair"),
+ }
+ }
+
+ /// Load a value pair with layout.abi of scalar pair
+ pub fn load_scalar_pair<'a>(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>) -> (Value, Value)
+ where
+ 'tcx: 'a,
+ {
+ match self {
+ CValue::ByRef(addr, layout) => {
+ let (a, b) = match &layout.abi {
+ layout::Abi::ScalarPair(a, b) => (a.clone(), b.clone()),
+ _ => unreachable!(),
+ };
+ let clif_ty1 = scalar_to_clif_type(fx.tcx, a.clone());
+ let clif_ty2 = scalar_to_clif_type(fx.tcx, b);
+ let val1 = fx.bcx.ins().load(clif_ty1, MemFlags::new(), addr, 0);
+ let val2 = fx.bcx.ins().load(
+ clif_ty2,
+ MemFlags::new(),
+ addr,
+ a.value.size(&fx.tcx).bytes() as i32,
+ );
+ (val1, val2)
+ }
+ CValue::ByVal(_, _layout) => bug!("Please use load_scalar for ByVal"),
+ CValue::ByValPair(val1, val2, _layout) => (val1, val2),
+ }
+ }
+
+ pub fn value_field<'a>(
+ self,
+ fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
+ field: mir::Field,
+ ) -> CValue<'tcx>
+ where
+ 'tcx: 'a,
+ {
+ let (base, layout) = match self {
+ CValue::ByRef(addr, layout) => (addr, layout),
+ _ => bug!("place_field for {:?}", self),
+ };
+
+ let (field_ptr, field_layout) = codegen_field(fx, base, layout, field);
+ CValue::ByRef(field_ptr, field_layout)
+ }
+
+ pub fn unsize_value<'a>(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>, dest: CPlace<'tcx>) {
+ crate::unsize::coerce_unsized_into(fx, self, dest);
+ }
+
+ pub fn const_val<'a>(
+ fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
+ ty: Ty<'tcx>,
+ const_val: i64,
+ ) -> CValue<'tcx>
+ where
+ 'tcx: 'a,
+ {
+ let clif_ty = fx.clif_type(ty).unwrap();
+ let layout = fx.layout_of(ty);
+ CValue::ByVal(fx.bcx.ins().iconst(clif_ty, const_val), layout)
+ }
+
+ pub fn unchecked_cast_to(self, layout: TyLayout<'tcx>) -> Self {
+ match self {
+ CValue::ByRef(addr, _) => CValue::ByRef(addr, layout),
+ CValue::ByVal(val, _) => CValue::ByVal(val, layout),
+ CValue::ByValPair(val, extra, _) => CValue::ByValPair(val, extra, layout),
+ }
+ }
+}
+
+/// A place where you can write a value to or read a value from
+#[derive(Debug, Copy, Clone)]
+pub enum CPlace<'tcx> {
+ Var(Local, TyLayout<'tcx>),
+ Addr(Value, Option<Value>, TyLayout<'tcx>),
+ Stack(StackSlot, TyLayout<'tcx>),
+ NoPlace(TyLayout<'tcx>),
+}
+
+impl<'a, 'tcx: 'a> CPlace<'tcx> {
+ pub fn layout(&self) -> TyLayout<'tcx> {
+ match *self {
+ CPlace::Var(_, layout)
+ | CPlace::Addr(_, _, layout)
+ | CPlace::Stack(_, layout)
+ | CPlace::NoPlace(layout) => layout,
+ }
+ }
+
+ pub fn no_place(layout: TyLayout<'tcx>) -> CPlace<'tcx> {
+ CPlace::NoPlace(layout)
+ }
+
+ pub fn new_stack_slot(
+ fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
+ ty: Ty<'tcx>,
+ ) -> CPlace<'tcx> {
+ let layout = fx.layout_of(ty);
+ assert!(!layout.is_unsized());
+ if layout.size.bytes() == 0 {
+ return CPlace::NoPlace(layout);
+ }
+
+ let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
+ kind: StackSlotKind::ExplicitSlot,
+ size: layout.size.bytes() as u32,
+ offset: None,
+ });
+ CPlace::Stack(stack_slot, layout)
+ }
+
+ pub fn new_var(
+ fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
+ local: Local,
+ layout: TyLayout<'tcx>,
+ ) -> CPlace<'tcx> {
+ fx.bcx
+ .declare_var(mir_var(local), fx.clif_type(layout.ty).unwrap());
+ CPlace::Var(local, layout)
+ }
+
+ pub fn to_cvalue(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>) -> CValue<'tcx> {
+ match self {
+ CPlace::Var(var, layout) => CValue::ByVal(fx.bcx.use_var(mir_var(var)), layout),
+ CPlace::Addr(addr, extra, layout) => {
+ assert!(extra.is_none(), "unsized values are not yet supported");
+ CValue::ByRef(addr, layout)
+ }
+ CPlace::Stack(stack_slot, layout) => CValue::ByRef(
+ fx.bcx.ins().stack_addr(fx.pointer_type, stack_slot, 0),
+ layout,
+ ),
+ CPlace::NoPlace(layout) => CValue::ByRef(
+ fx.bcx
+ .ins()
+ .iconst(fx.pointer_type, fx.pointer_type.bytes() as i64),
+ layout,
+ ),
+ }
+ }
+
+ pub fn to_addr(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>) -> Value {
+ match self.to_addr_maybe_unsized(fx) {
+ (addr, None) => addr,
+ (_, Some(_)) => bug!("Expected sized cplace, found {:?}", self),
+ }
+ }
+
+ pub fn to_addr_maybe_unsized(
+ self,
+ fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
+ ) -> (Value, Option<Value>) {
+ match self {
+ CPlace::Addr(addr, extra, _layout) => (addr, extra),
+ CPlace::Stack(stack_slot, _layout) => (
+ fx.bcx.ins().stack_addr(fx.pointer_type, stack_slot, 0),
+ None,
+ ),
+ CPlace::NoPlace(_) => (fx.bcx.ins().iconst(fx.pointer_type, 45), None),
+ CPlace::Var(_, _) => bug!("Expected CPlace::Addr, found CPlace::Var"),
+ }
+ }
+
+ pub fn write_cvalue(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>, from: CValue<'tcx>) {
+ use rustc::hir::Mutability::*;
+
+ let from_ty = from.layout().ty;
+ let to_ty = self.layout().ty;
+
+ fn assert_assignable<'a, 'tcx: 'a>(fx: &FunctionCx<'a, 'tcx, impl Backend>, from_ty: Ty<'tcx>, to_ty: Ty<'tcx>) {
+ match (&from_ty.sty, &to_ty.sty) {
+ (ty::Ref(_, t, MutImmutable), ty::Ref(_, u, MutImmutable))
+ | (ty::Ref(_, t, MutMutable), ty::Ref(_, u, MutImmutable))
+ | (ty::Ref(_, t, MutMutable), ty::Ref(_, u, MutMutable)) => {
+ assert_assignable(fx, t, u);
+ // &mut T -> &T is allowed
+ // &'a T -> &'b T is allowed
+ }
+ (ty::Ref(_, _, MutImmutable), ty::Ref(_, _, MutMutable)) => {
+ panic!("Cant assign value of type {} to place of type {}", from_ty, to_ty)
+ }
+ (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, _)) => {
+ let from_traits = fx.tcx.normalize_erasing_late_bound_regions(
+ ParamEnv::reveal_all(),
+ from_traits,
+ );
+ let to_traits = fx.tcx.normalize_erasing_late_bound_regions(
+ ParamEnv::reveal_all(),
+ to_traits,
+ );
+ assert_eq!(
+ from_traits, to_traits,
+ "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
+ }
+ _ => {
+ assert_eq!(
+ from_ty,
+ to_ty,
+ "Can't write value with incompatible type {:?} to place with type {:?}\n\n{:#?}",
+ from_ty,
+ to_ty,
+ fx,
+ );
+ }
+ }
+ }
+
+ assert_assignable(fx, from_ty, to_ty);
+
+ let (addr, dst_layout) = match self {
+ CPlace::Var(var, _) => {
+ let data = from.load_scalar(fx);
+ fx.bcx.def_var(mir_var(var), data);
+ return;
+ }
+ CPlace::Addr(addr, None, dst_layout) => (addr, dst_layout),
+ CPlace::Stack(stack_slot, dst_layout) => (
+ fx.bcx.ins().stack_addr(fx.pointer_type, stack_slot, 0),
+ dst_layout,
+ ),
+ CPlace::NoPlace(layout) => {
+ assert_eq!(layout.size.bytes(), 0);
+ assert_eq!(from.layout().size.bytes(), 0);
+ return;
+ }
+ CPlace::Addr(_, _, _) => bug!("Can't write value to unsized place {:?}", self),
+ };
+
+ match from {
+ CValue::ByVal(val, _src_layout) => {
+ fx.bcx.ins().store(MemFlags::new(), val, addr, 0);
+ }
+ CValue::ByValPair(val1, val2, _src_layout) => {
+ let val1_offset = dst_layout.fields.offset(0).bytes() as i32;
+ let val2_offset = dst_layout.fields.offset(1).bytes() as i32;
+ fx.bcx.ins().store(MemFlags::new(), val1, addr, val1_offset);
+ fx.bcx.ins().store(MemFlags::new(), val2, addr, val2_offset);
+ }
+ CValue::ByRef(from, src_layout) => {
+ 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_memcpy(
+ fx.module.target_config(),
+ addr,
+ from,
+ size,
+ dst_align,
+ src_align,
+ );
+ }
+ }
+ }
+
+ pub fn place_field(
+ self,
+ fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
+ field: mir::Field,
+ ) -> CPlace<'tcx> {
+ let layout = self.layout();
+ let (base, extra) = self.to_addr_maybe_unsized(fx);
+
+ let (field_ptr, field_layout) = codegen_field(fx, base, layout, field);
+ let extra = if field_layout.is_unsized() {
+ assert!(extra.is_some());
+ extra
+ } else {
+ None
+ };
+ CPlace::Addr(field_ptr, extra, field_layout)
+ }
+
+ pub fn place_index(
+ self,
+ fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
+ index: Value,
+ ) -> CPlace<'tcx> {
+ let (elem_layout, addr) = match self.layout().ty.sty {
+ ty::Array(elem_ty, _) => (fx.layout_of(elem_ty), self.to_addr(fx)),
+ ty::Slice(elem_ty) => (fx.layout_of(elem_ty), self.to_addr_maybe_unsized(fx).0),
+ _ => bug!("place_index({:?})", self.layout().ty),
+ };
+
+ let offset = fx
+ .bcx
+ .ins()
+ .imul_imm(index, elem_layout.size.bytes() as i64);
+
+ CPlace::Addr(fx.bcx.ins().iadd(addr, offset), None, elem_layout)
+ }
+
+ pub fn place_deref(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>) -> CPlace<'tcx> {
+ let inner_layout = fx.layout_of(self.layout().ty.builtin_deref(true).unwrap().ty);
+ if !inner_layout.is_unsized() {
+ CPlace::Addr(self.to_cvalue(fx).load_scalar(fx), None, inner_layout)
+ } else {
+ match self.layout().abi {
+ Abi::ScalarPair(ref a, ref b) => {
+ let addr = self.to_addr(fx);
+ let ptr =
+ fx.bcx
+ .ins()
+ .load(scalar_to_clif_type(fx.tcx, a.clone()), MemFlags::new(), addr, 0);
+ let extra = fx.bcx.ins().load(
+ scalar_to_clif_type(fx.tcx, b.clone()),
+ MemFlags::new(),
+ addr,
+ a.value.size(&fx.tcx).bytes() as u32 as i32,
+ );
+ CPlace::Addr(ptr, Some(extra), inner_layout)
+ }
+ _ => bug!(
+ "Fat ptr doesn't have abi ScalarPair, but it has {:?}",
+ self.layout().abi
+ ),
+ }
+ }
+ }
+
+ pub fn write_place_ref(self, fx: &mut FunctionCx<'a, 'tcx, impl Backend>, dest: CPlace<'tcx>) {
+ if !self.layout().is_unsized() {
+ let ptr = CValue::ByVal(self.to_addr(fx), dest.layout());
+ dest.write_cvalue(fx, ptr);
+ } else {
+ let (value, extra) = self.to_addr_maybe_unsized(fx);
+
+ match dest.layout().abi {
+ Abi::ScalarPair(ref a, _) => {
+ let dest_addr = dest.to_addr(fx);
+ fx.bcx.ins().store(MemFlags::new(), value, dest_addr, 0);
+ fx.bcx.ins().store(
+ MemFlags::new(),
+ extra.expect("unsized type without metadata"),
+ dest_addr,
+ a.value.size(&fx.tcx).bytes() as u32 as i32,
+ );
+ }
+ _ => bug!(
+ "Non ScalarPair abi {:?} in write_place_ref dest",
+ dest.layout().abi
+ ),
+ }
+ }
+ }
+
+ pub fn unchecked_cast_to(self, layout: TyLayout<'tcx>) -> Self {
+ assert!(!self.layout().is_unsized());
+ match self {
+ CPlace::Var(var, _) => CPlace::Var(var, layout),
+ CPlace::Addr(addr, extra, _) => CPlace::Addr(addr, extra, layout),
+ CPlace::Stack(stack_slot, _) => CPlace::Stack(stack_slot, layout),
+ CPlace::NoPlace(_) => {
+ assert!(layout.size.bytes() == 0);
+ CPlace::NoPlace(layout)
+ }
+ }
+ }
+
+ pub fn downcast_variant(
+ self,
+ fx: &FunctionCx<'a, 'tcx, impl Backend>,
+ variant: VariantIdx,
+ ) -> Self {
+ let layout = self.layout().for_variant(fx, variant);
+ self.unchecked_cast_to(layout)
+ }
+}
projects / rust.git / commitdiff