3 fn codegen_field<'tcx>(
4 fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
6 layout: TyLayout<'tcx>,
8 ) -> (Value, TyLayout<'tcx>) {
9 let field_offset = layout.fields.offset(field.index());
10 let field_ty = layout.field(&*fx, field.index());
11 if field_offset.bytes() > 0 {
13 fx.bcx.ins().iadd_imm(base, field_offset.bytes() as i64),
21 fn scalar_pair_calculate_b_offset(tcx: TyCtxt<'_>, a_scalar: &Scalar, b_scalar: &Scalar) -> i32 {
22 let b_offset = a_scalar.value.size(&tcx).align_to(b_scalar.value.align(&tcx).abi);
23 b_offset.bytes().try_into().unwrap()
27 #[derive(Debug, Copy, Clone)]
28 pub struct CValue<'tcx>(CValueInner, TyLayout<'tcx>);
30 #[derive(Debug, Copy, Clone)]
34 ByValPair(Value, Value),
37 impl<'tcx> CValue<'tcx> {
38 pub fn by_ref(value: Value, layout: TyLayout<'tcx>) -> CValue<'tcx> {
39 CValue(CValueInner::ByRef(value), layout)
42 pub fn by_val(value: Value, layout: TyLayout<'tcx>) -> CValue<'tcx> {
43 CValue(CValueInner::ByVal(value), layout)
46 pub fn by_val_pair(value: Value, extra: Value, layout: TyLayout<'tcx>) -> CValue<'tcx> {
47 CValue(CValueInner::ByValPair(value, extra), layout)
50 pub fn layout(&self) -> TyLayout<'tcx> {
54 pub fn force_stack<'a>(self, fx: &mut FunctionCx<'_, 'tcx, impl Backend>) -> Value {
57 CValueInner::ByRef(value) => value,
58 CValueInner::ByVal(_) | CValueInner::ByValPair(_, _) => {
59 let cplace = CPlace::new_stack_slot(fx, layout.ty);
60 cplace.write_cvalue(fx, self);
66 pub fn try_to_addr(self) -> Option<Value> {
68 CValueInner::ByRef(addr) => Some(addr),
69 CValueInner::ByVal(_) | CValueInner::ByValPair(_, _) => None,
73 /// Load a value with layout.abi of scalar
74 pub fn load_scalar<'a>(self, fx: &mut FunctionCx<'_, 'tcx, impl Backend>) -> Value {
77 CValueInner::ByRef(addr) => {
78 let scalar = match layout.abi {
79 layout::Abi::Scalar(ref scalar) => scalar.clone(),
82 let clif_ty = scalar_to_clif_type(fx.tcx, scalar);
83 fx.bcx.ins().load(clif_ty, MemFlags::new(), addr, 0)
85 CValueInner::ByVal(value) => value,
86 CValueInner::ByValPair(_, _) => bug!("Please use load_scalar_pair for ByValPair"),
90 /// Load a value pair with layout.abi of scalar pair
91 pub fn load_scalar_pair<'a>(self, fx: &mut FunctionCx<'_, 'tcx, impl Backend>) -> (Value, Value) {
94 CValueInner::ByRef(addr) => {
95 let (a_scalar, b_scalar) = match &layout.abi {
96 layout::Abi::ScalarPair(a, b) => (a, b),
99 let b_offset = scalar_pair_calculate_b_offset(fx.tcx, a_scalar, b_scalar);
100 let clif_ty1 = scalar_to_clif_type(fx.tcx, a_scalar.clone());
101 let clif_ty2 = scalar_to_clif_type(fx.tcx, b_scalar.clone());
102 let val1 = fx.bcx.ins().load(clif_ty1, MemFlags::new(), addr, 0);
103 let val2 = fx.bcx.ins().load(
111 CValueInner::ByVal(_) => bug!("Please use load_scalar for ByVal"),
112 CValueInner::ByValPair(val1, val2) => (val1, val2),
116 pub fn value_field<'a>(
118 fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
122 let base = match self.0 {
123 CValueInner::ByRef(addr) => addr,
124 _ => bug!("place_field for {:?}", self),
127 let (field_ptr, field_layout) = codegen_field(fx, base, layout, field);
128 CValue::by_ref(field_ptr, field_layout)
131 pub fn unsize_value<'a>(self, fx: &mut FunctionCx<'_, 'tcx, impl Backend>, dest: CPlace<'tcx>) {
132 crate::unsize::coerce_unsized_into(fx, self, dest);
135 /// If `ty` is signed, `const_val` must already be sign extended.
136 pub fn const_val<'a>(
137 fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
141 let clif_ty = fx.clif_type(ty).unwrap();
142 let layout = fx.layout_of(ty);
144 let val = match ty.sty {
145 ty::TyKind::Uint(UintTy::U128) | ty::TyKind::Int(IntTy::I128) => {
146 let lsb = fx.bcx.ins().iconst(types::I64, const_val as u64 as i64);
147 let msb = fx.bcx.ins().iconst(types::I64, (const_val >> 64) as u64 as i64);
148 fx.bcx.ins().iconcat(lsb, msb)
150 ty::TyKind::Bool => {
151 assert!(const_val == 0 || const_val == 1, "Invalid bool 0x{:032X}", const_val);
152 fx.bcx.ins().iconst(types::I8, const_val as i64)
154 ty::TyKind::Uint(_) | ty::TyKind::Ref(..) | ty::TyKind::RawPtr(.. )=> {
155 fx.bcx.ins().iconst(clif_ty, u64::try_from(const_val).expect("uint") as i64)
157 ty::TyKind::Int(_) => {
158 fx.bcx.ins().iconst(clif_ty, const_val as i128 as i64)
160 _ => panic!("CValue::const_val for non bool/integer/pointer type {:?} is not allowed", ty),
163 CValue::by_val(val, layout)
166 pub fn unchecked_cast_to(self, layout: TyLayout<'tcx>) -> Self {
167 CValue(self.0, layout)
171 /// A place where you can write a value to or read a value from
172 #[derive(Debug, Copy, Clone)]
173 pub struct CPlace<'tcx> {
175 layout: TyLayout<'tcx>,
178 #[derive(Debug, Copy, Clone)]
179 pub enum CPlaceInner {
181 Addr(Value, Option<Value>),
186 impl<'tcx> CPlace<'tcx> {
187 pub fn layout(&self) -> TyLayout<'tcx> {
191 pub fn inner(&self) -> &CPlaceInner {
195 pub fn no_place(layout: TyLayout<'tcx>) -> CPlace<'tcx> {
197 inner: CPlaceInner::NoPlace,
202 pub fn new_stack_slot(
203 fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
206 let layout = fx.layout_of(ty);
207 assert!(!layout.is_unsized());
208 if layout.size.bytes() == 0 {
210 inner: CPlaceInner::NoPlace,
215 let stack_slot = fx.bcx.create_stack_slot(StackSlotData {
216 kind: StackSlotKind::ExplicitSlot,
217 size: layout.size.bytes() as u32,
221 inner: CPlaceInner::Stack(stack_slot),
227 fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
229 layout: TyLayout<'tcx>,
232 .declare_var(mir_var(local), fx.clif_type(layout.ty).unwrap());
234 inner: CPlaceInner::Var(local),
239 pub fn for_addr(addr: Value, layout: TyLayout<'tcx>) -> CPlace<'tcx> {
241 inner: CPlaceInner::Addr(addr, None),
246 pub fn for_addr_with_extra(addr: Value, extra: Value, layout: TyLayout<'tcx>) -> CPlace<'tcx> {
248 inner: CPlaceInner::Addr(addr, Some(extra)),
253 pub fn to_cvalue(self, fx: &mut FunctionCx<'_, 'tcx, impl Backend>) -> CValue<'tcx> {
254 let layout = self.layout();
256 CPlaceInner::Var(var) => CValue::by_val(fx.bcx.use_var(mir_var(var)), layout),
257 CPlaceInner::Addr(addr, extra) => {
258 assert!(extra.is_none(), "unsized values are not yet supported");
259 CValue::by_ref(addr, layout)
261 CPlaceInner::Stack(stack_slot) => CValue::by_ref(
262 fx.bcx.ins().stack_addr(fx.pointer_type, stack_slot, 0),
265 CPlaceInner::NoPlace => CValue::by_ref(
268 .iconst(fx.pointer_type, fx.pointer_type.bytes() as i64),
274 pub fn to_addr(self, fx: &mut FunctionCx<'_, 'tcx, impl Backend>) -> Value {
275 match self.to_addr_maybe_unsized(fx) {
276 (addr, None) => addr,
277 (_, Some(_)) => bug!("Expected sized cplace, found {:?}", self),
281 pub fn to_addr_maybe_unsized(
283 fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
284 ) -> (Value, Option<Value>) {
286 CPlaceInner::Addr(addr, extra) => (addr, extra),
287 CPlaceInner::Stack(stack_slot) => (
288 fx.bcx.ins().stack_addr(fx.pointer_type, stack_slot, 0),
291 CPlaceInner::NoPlace => (fx.bcx.ins().iconst(fx.pointer_type, 45), None),
292 CPlaceInner::Var(_) => bug!("Expected CPlace::Addr, found CPlace::Var"),
296 pub fn write_cvalue(self, fx: &mut FunctionCx<'_, 'tcx, impl Backend>, from: CValue<'tcx>) {
297 use rustc::hir::Mutability::*;
299 let from_ty = from.layout().ty;
300 let to_ty = self.layout().ty;
302 fn assert_assignable<'tcx>(fx: &FunctionCx<'_, 'tcx, impl Backend>, from_ty: Ty<'tcx>, to_ty: Ty<'tcx>) {
303 match (&from_ty.sty, &to_ty.sty) {
304 (ty::Ref(_, t, MutImmutable), ty::Ref(_, u, MutImmutable))
305 | (ty::Ref(_, t, MutMutable), ty::Ref(_, u, MutImmutable))
306 | (ty::Ref(_, t, MutMutable), ty::Ref(_, u, MutMutable)) => {
307 assert_assignable(fx, t, u);
308 // &mut T -> &T is allowed
309 // &'a T -> &'b T is allowed
311 (ty::Ref(_, _, MutImmutable), ty::Ref(_, _, MutMutable)) => {
312 panic!("Cant assign value of type {} to place of type {}", from_ty, to_ty)
314 (ty::FnPtr(_), ty::FnPtr(_)) => {
315 let from_sig = fx.tcx.normalize_erasing_late_bound_regions(
316 ParamEnv::reveal_all(),
317 &from_ty.fn_sig(fx.tcx),
319 let to_sig = fx.tcx.normalize_erasing_late_bound_regions(
320 ParamEnv::reveal_all(),
321 &to_ty.fn_sig(fx.tcx),
325 "Can't write fn ptr with incompatible sig {:?} to place with sig {:?}\n\n{:#?}",
326 from_sig, to_sig, fx,
328 // fn(&T) -> for<'l> fn(&'l T) is allowed
330 (ty::Dynamic(from_traits, _), ty::Dynamic(to_traits, _)) => {
331 let from_traits = fx.tcx.normalize_erasing_late_bound_regions(
332 ParamEnv::reveal_all(),
335 let to_traits = fx.tcx.normalize_erasing_late_bound_regions(
336 ParamEnv::reveal_all(),
340 from_traits, to_traits,
341 "Can't write trait object of incompatible traits {:?} to place with traits {:?}\n\n{:#?}",
342 from_traits, to_traits, fx,
344 // dyn for<'r> Trait<'r> -> dyn Trait<'_> is allowed
350 "Can't write value with incompatible type {:?} to place with type {:?}\n\n{:#?}",
359 assert_assignable(fx, from_ty, to_ty);
361 let dst_layout = self.layout();
362 let addr = match self.inner {
363 CPlaceInner::Var(var) => {
364 let data = from.load_scalar(fx);
365 fx.bcx.def_var(mir_var(var), data);
368 CPlaceInner::Addr(addr, None) => addr,
369 CPlaceInner::Stack(stack_slot) => {
370 fx.bcx.ins().stack_addr(fx.pointer_type, stack_slot, 0)
372 CPlaceInner::NoPlace => {
373 if dst_layout.abi != Abi::Uninhabited {
374 assert_eq!(dst_layout.size.bytes(), 0, "{:?}", dst_layout);
378 CPlaceInner::Addr(_, Some(_)) => bug!("Can't write value to unsized place {:?}", self),
382 CValueInner::ByVal(val) => {
383 fx.bcx.ins().store(MemFlags::new(), val, addr, 0);
385 CValueInner::ByValPair(value, extra) => {
386 match dst_layout.abi {
387 Abi::ScalarPair(ref a_scalar, ref b_scalar) => {
388 let b_offset = scalar_pair_calculate_b_offset(fx.tcx, a_scalar, b_scalar);
389 fx.bcx.ins().store(MemFlags::new(), value, addr, 0);
398 "Non ScalarPair abi {:?} for ByValPair CValue",
403 CValueInner::ByRef(from_addr) => {
404 let src_layout = from.1;
405 let size = dst_layout.size.bytes();
406 let src_align = src_layout.align.abi.bytes() as u8;
407 let dst_align = dst_layout.align.abi.bytes() as u8;
408 fx.bcx.emit_small_memcpy(
409 fx.module.target_config(),
422 fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
425 let layout = self.layout();
426 let (base, extra) = self.to_addr_maybe_unsized(fx);
428 let (field_ptr, field_layout) = codegen_field(fx, base, layout, field);
429 if field_layout.is_unsized() {
430 CPlace::for_addr_with_extra(field_ptr, extra.unwrap(), field_layout)
432 CPlace::for_addr(field_ptr, field_layout)
438 fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
441 let (elem_layout, addr) = match self.layout().ty.sty {
442 ty::Array(elem_ty, _) => (fx.layout_of(elem_ty), self.to_addr(fx)),
443 ty::Slice(elem_ty) => (fx.layout_of(elem_ty), self.to_addr_maybe_unsized(fx).0),
444 _ => bug!("place_index({:?})", self.layout().ty),
450 .imul_imm(index, elem_layout.size.bytes() as i64);
452 CPlace::for_addr(fx.bcx.ins().iadd(addr, offset), elem_layout)
455 pub fn place_deref(self, fx: &mut FunctionCx<'_, 'tcx, impl Backend>) -> CPlace<'tcx> {
456 let inner_layout = fx.layout_of(self.layout().ty.builtin_deref(true).unwrap().ty);
457 if !inner_layout.is_unsized() {
458 CPlace::for_addr(self.to_cvalue(fx).load_scalar(fx), inner_layout)
460 let (addr, extra) = self.to_cvalue(fx).load_scalar_pair(fx);
461 CPlace::for_addr_with_extra(addr, extra, inner_layout)
465 pub fn write_place_ref(self, fx: &mut FunctionCx<'_, 'tcx, impl Backend>, dest: CPlace<'tcx>) {
466 if !self.layout().is_unsized() {
467 let ptr = CValue::by_val(self.to_addr(fx), dest.layout());
468 dest.write_cvalue(fx, ptr);
470 let (value, extra) = self.to_addr_maybe_unsized(fx);
471 let ptr = CValue::by_val_pair(value, extra.expect("unsized type without metadata"), dest.layout());
472 dest.write_cvalue(fx, ptr);
476 pub fn unchecked_cast_to(self, layout: TyLayout<'tcx>) -> Self {
477 assert!(!self.layout().is_unsized());
479 CPlaceInner::NoPlace => {
480 assert!(layout.size.bytes() == 0);
490 pub fn downcast_variant(
492 fx: &FunctionCx<'_, 'tcx, impl Backend>,
495 let layout = self.layout().for_variant(fx, variant);
496 self.unchecked_cast_to(layout)