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Commit | Line | Data |
---|---|---|
923072b8 | 1 | use std::assert_matches::assert_matches; |
ba9703b0 | 2 | use std::convert::TryFrom; |
ea8adc8c | 3 | |
dfeec247 XL |
4 | use rustc_apfloat::ieee::{Double, Single}; |
5 | use rustc_apfloat::{Float, FloatConvert}; | |
ba9703b0 XL |
6 | use rustc_middle::mir::interpret::{InterpResult, PointerArithmetic, Scalar}; |
7 | use rustc_middle::mir::CastKind; | |
8 | use rustc_middle::ty::adjustment::PointerCast; | |
c295e0f8 | 9 | use rustc_middle::ty::layout::{IntegerExt, LayoutOf, TyAndLayout}; |
5869c6ff | 10 | use rustc_middle::ty::{self, FloatTy, Ty, TypeAndMut}; |
064997fb | 11 | use rustc_target::abi::Integer; |
923072b8 | 12 | use rustc_type_ir::sty::TyKind::*; |
f9f354fc | 13 | |
3dfed10e | 14 | use super::{ |
29967ef6 | 15 | util::ensure_monomorphic_enough, FnVal, ImmTy, Immediate, InterpCx, Machine, OpTy, PlaceTy, |
3dfed10e | 16 | }; |
b7449926 | 17 | |
ba9703b0 | 18 | impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { |
b7449926 | 19 | pub fn cast( |
8faf50e0 | 20 | &mut self, |
064997fb | 21 | src: &OpTy<'tcx, M::Provenance>, |
f9f354fc XL |
22 | cast_kind: CastKind, |
23 | cast_ty: Ty<'tcx>, | |
064997fb | 24 | dest: &PlaceTy<'tcx, M::Provenance>, |
dc9dc135 | 25 | ) -> InterpResult<'tcx> { |
ba9703b0 | 26 | use rustc_middle::mir::CastKind::*; |
f9f354fc XL |
27 | // FIXME: In which cases should we trigger UB when the source is uninit? |
28 | match cast_kind { | |
48663c56 | 29 | Pointer(PointerCast::Unsize) => { |
f9f354fc XL |
30 | let cast_ty = self.layout_of(cast_ty)?; |
31 | self.unsize_into(src, cast_ty, dest)?; | |
8faf50e0 XL |
32 | } |
33 | ||
923072b8 FG |
34 | PointerExposeAddress => { |
35 | let src = self.read_immediate(src)?; | |
36 | let res = self.pointer_expose_address_cast(&src, cast_ty)?; | |
37 | self.write_immediate(res, dest)?; | |
38 | } | |
39 | ||
40 | PointerFromExposedAddress => { | |
41 | let src = self.read_immediate(src)?; | |
42 | let res = self.pointer_from_exposed_address_cast(&src, cast_ty)?; | |
43 | self.write_immediate(res, dest)?; | |
44 | } | |
45 | ||
f9f354fc | 46 | Misc => { |
a1dfa0c6 | 47 | let src = self.read_immediate(src)?; |
6a06907d | 48 | let res = self.misc_cast(&src, cast_ty)?; |
416331ca | 49 | self.write_immediate(res, dest)?; |
8faf50e0 XL |
50 | } |
51 | ||
f9f354fc XL |
52 | Pointer(PointerCast::MutToConstPointer | PointerCast::ArrayToPointer) => { |
53 | // These are NOPs, but can be wide pointers. | |
54 | let v = self.read_immediate(src)?; | |
55 | self.write_immediate(*v, dest)?; | |
56 | } | |
57 | ||
48663c56 | 58 | Pointer(PointerCast::ReifyFnPointer) => { |
b7449926 | 59 | // The src operand does not matter, just its type |
1b1a35ee | 60 | match *src.layout.ty.kind() { |
b7449926 | 61 | ty::FnDef(def_id, substs) => { |
e1599b0c | 62 | // All reifications must be monomorphic, bail out otherwise. |
3dfed10e | 63 | ensure_monomorphic_enough(*self.tcx, src.layout.ty)?; |
e1599b0c | 64 | |
e74abb32 XL |
65 | let instance = ty::Instance::resolve_for_fn_ptr( |
66 | *self.tcx, | |
67 | self.param_env, | |
68 | def_id, | |
69 | substs, | |
dfeec247 XL |
70 | ) |
71 | .ok_or_else(|| err_inval!(TooGeneric))?; | |
e74abb32 | 72 | |
04454e1e | 73 | let fn_ptr = self.create_fn_alloc_ptr(FnVal::Instance(instance)); |
136023e0 | 74 | self.write_pointer(fn_ptr, dest)?; |
8faf50e0 | 75 | } |
f035d41b | 76 | _ => span_bug!(self.cur_span(), "reify fn pointer on {:?}", src.layout.ty), |
8faf50e0 XL |
77 | } |
78 | } | |
79 | ||
48663c56 | 80 | Pointer(PointerCast::UnsafeFnPointer) => { |
a1dfa0c6 | 81 | let src = self.read_immediate(src)?; |
1b1a35ee | 82 | match cast_ty.kind() { |
b7449926 XL |
83 | ty::FnPtr(_) => { |
84 | // No change to value | |
a1dfa0c6 | 85 | self.write_immediate(*src, dest)?; |
8faf50e0 | 86 | } |
f035d41b | 87 | _ => span_bug!(self.cur_span(), "fn to unsafe fn cast on {:?}", cast_ty), |
8faf50e0 XL |
88 | } |
89 | } | |
90 | ||
48663c56 | 91 | Pointer(PointerCast::ClosureFnPointer(_)) => { |
b7449926 | 92 | // The src operand does not matter, just its type |
1b1a35ee | 93 | match *src.layout.ty.kind() { |
b7449926 | 94 | ty::Closure(def_id, substs) => { |
e1599b0c | 95 | // All reifications must be monomorphic, bail out otherwise. |
3dfed10e | 96 | ensure_monomorphic_enough(*self.tcx, src.layout.ty)?; |
e1599b0c | 97 | |
8faf50e0 XL |
98 | let instance = ty::Instance::resolve_closure( |
99 | *self.tcx, | |
100 | def_id, | |
101 | substs, | |
102 | ty::ClosureKind::FnOnce, | |
064997fb FG |
103 | ) |
104 | .ok_or_else(|| err_inval!(TooGeneric))?; | |
04454e1e | 105 | let fn_ptr = self.create_fn_alloc_ptr(FnVal::Instance(instance)); |
136023e0 | 106 | self.write_pointer(fn_ptr, dest)?; |
8faf50e0 | 107 | } |
f035d41b | 108 | _ => span_bug!(self.cur_span(), "closure fn pointer on {:?}", src.layout.ty), |
8faf50e0 XL |
109 | } |
110 | } | |
111 | } | |
112 | Ok(()) | |
113 | } | |
114 | ||
5e7ed085 | 115 | pub fn misc_cast( |
04454e1e | 116 | &mut self, |
064997fb | 117 | src: &ImmTy<'tcx, M::Provenance>, |
f9f354fc | 118 | cast_ty: Ty<'tcx>, |
064997fb | 119 | ) -> InterpResult<'tcx, Immediate<M::Provenance>> { |
923072b8 | 120 | use rustc_type_ir::sty::TyKind::*; |
f9f354fc | 121 | trace!("Casting {:?}: {:?} to {:?}", *src, src.layout.ty, cast_ty); |
ea8adc8c | 122 | |
1b1a35ee | 123 | match src.layout.ty.kind() { |
dc9dc135 | 124 | // Floating point |
dfeec247 | 125 | Float(FloatTy::F32) => { |
f9f354fc | 126 | return Ok(self.cast_from_float(src.to_scalar()?.to_f32()?, cast_ty).into()); |
dfeec247 XL |
127 | } |
128 | Float(FloatTy::F64) => { | |
f9f354fc | 129 | return Ok(self.cast_from_float(src.to_scalar()?.to_f64()?, cast_ty).into()); |
dfeec247 | 130 | } |
064997fb | 131 | // The rest is integer/pointer-"like", including fn ptr casts |
dfeec247 XL |
132 | _ => assert!( |
133 | src.layout.ty.is_bool() | |
134 | || src.layout.ty.is_char() | |
dfeec247 XL |
135 | || src.layout.ty.is_integral() |
136 | || src.layout.ty.is_any_ptr(), | |
137 | "Unexpected cast from type {:?}", | |
138 | src.layout.ty | |
139 | ), | |
416331ca XL |
140 | } |
141 | ||
f9f354fc XL |
142 | // # First handle non-scalar source values. |
143 | ||
416331ca | 144 | // Handle casting any ptr to raw ptr (might be a fat ptr). |
f9f354fc XL |
145 | if src.layout.ty.is_any_ptr() && cast_ty.is_unsafe_ptr() { |
146 | let dest_layout = self.layout_of(cast_ty)?; | |
147 | if dest_layout.size == src.layout.size { | |
148 | // Thin or fat pointer that just hast the ptr kind of target type changed. | |
6a06907d | 149 | return Ok(**src); |
f9f354fc XL |
150 | } else { |
151 | // Casting the metadata away from a fat ptr. | |
04454e1e FG |
152 | assert_eq!(src.layout.size, 2 * self.pointer_size()); |
153 | assert_eq!(dest_layout.size, self.pointer_size()); | |
f9f354fc | 154 | assert!(src.layout.ty.is_unsafe_ptr()); |
6a06907d | 155 | return match **src { |
064997fb | 156 | Immediate::ScalarPair(data, _) => Ok(data.check_init()?.into()), |
f035d41b XL |
157 | Immediate::Scalar(..) => span_bug!( |
158 | self.cur_span(), | |
f9f354fc XL |
159 | "{:?} input to a fat-to-thin cast ({:?} -> {:?})", |
160 | *src, | |
161 | src.layout.ty, | |
162 | cast_ty | |
163 | ), | |
064997fb | 164 | Immediate::Uninit => throw_ub!(InvalidUninitBytes(None)), |
f9f354fc XL |
165 | }; |
166 | } | |
ea8adc8c | 167 | } |
416331ca | 168 | |
5e7ed085 | 169 | // # The remaining source values are scalar and "int-like". |
04454e1e | 170 | let scalar = src.to_scalar()?; |
923072b8 FG |
171 | Ok(self.cast_from_int_like(scalar, src.layout, cast_ty)?.into()) |
172 | } | |
04454e1e | 173 | |
923072b8 FG |
174 | pub fn pointer_expose_address_cast( |
175 | &mut self, | |
064997fb | 176 | src: &ImmTy<'tcx, M::Provenance>, |
923072b8 | 177 | cast_ty: Ty<'tcx>, |
064997fb | 178 | ) -> InterpResult<'tcx, Immediate<M::Provenance>> { |
923072b8 FG |
179 | assert_matches!(src.layout.ty.kind(), ty::RawPtr(_) | ty::FnPtr(_)); |
180 | assert!(cast_ty.is_integral()); | |
f9f354fc | 181 | |
923072b8 | 182 | let scalar = src.to_scalar()?; |
064997fb | 183 | let ptr = scalar.to_pointer(self)?; |
923072b8 FG |
184 | match ptr.into_pointer_or_addr() { |
185 | Ok(ptr) => M::expose_ptr(self, ptr)?, | |
064997fb | 186 | Err(_) => {} // Do nothing, exposing an invalid pointer (`None` provenance) is a NOP. |
923072b8 | 187 | }; |
04454e1e | 188 | Ok(self.cast_from_int_like(scalar, src.layout, cast_ty)?.into()) |
ea8adc8c XL |
189 | } |
190 | ||
923072b8 FG |
191 | pub fn pointer_from_exposed_address_cast( |
192 | &mut self, | |
064997fb | 193 | src: &ImmTy<'tcx, M::Provenance>, |
923072b8 | 194 | cast_ty: Ty<'tcx>, |
064997fb | 195 | ) -> InterpResult<'tcx, Immediate<M::Provenance>> { |
923072b8 FG |
196 | assert!(src.layout.ty.is_integral()); |
197 | assert_matches!(cast_ty.kind(), ty::RawPtr(_)); | |
198 | ||
199 | // First cast to usize. | |
200 | let scalar = src.to_scalar()?; | |
201 | let addr = self.cast_from_int_like(scalar, src.layout, self.tcx.types.usize)?; | |
202 | let addr = addr.to_machine_usize(self)?; | |
203 | ||
204 | // Then turn address into pointer. | |
205 | let ptr = M::ptr_from_addr_cast(&self, addr)?; | |
206 | Ok(Scalar::from_maybe_pointer(ptr, self).into()) | |
207 | } | |
208 | ||
04454e1e | 209 | pub fn cast_from_int_like( |
ea8adc8c | 210 | &self, |
064997fb | 211 | scalar: Scalar<M::Provenance>, // input value (there is no ScalarTy so we separate data+layout) |
ba9703b0 | 212 | src_layout: TyAndLayout<'tcx>, |
f9f354fc | 213 | cast_ty: Ty<'tcx>, |
064997fb | 214 | ) -> InterpResult<'tcx, Scalar<M::Provenance>> { |
dc9dc135 | 215 | // Let's make sure v is sign-extended *if* it has a signed type. |
f9f354fc | 216 | let signed = src_layout.abi.is_signed(); // Also asserts that abi is `Scalar`. |
04454e1e FG |
217 | |
218 | let v = scalar.to_bits(src_layout.size)?; | |
dfeec247 | 219 | let v = if signed { self.sign_extend(v, src_layout) } else { v }; |
f9f354fc | 220 | trace!("cast_from_scalar: {}, {} -> {}", v, src_layout.ty, cast_ty); |
04454e1e FG |
221 | |
222 | Ok(match *cast_ty.kind() { | |
223 | Int(_) | Uint(_) => { | |
1b1a35ee | 224 | let size = match *cast_ty.kind() { |
5869c6ff XL |
225 | Int(t) => Integer::from_int_ty(self, t).size(), |
226 | Uint(t) => Integer::from_uint_ty(self, t).size(), | |
f9f354fc XL |
227 | _ => bug!(), |
228 | }; | |
29967ef6 | 229 | let v = size.truncate(v); |
f9f354fc | 230 | Scalar::from_uint(v, size) |
0531ce1d | 231 | } |
ea8adc8c | 232 | |
f9f354fc XL |
233 | Float(FloatTy::F32) if signed => Scalar::from_f32(Single::from_i128(v as i128).value), |
234 | Float(FloatTy::F64) if signed => Scalar::from_f64(Double::from_i128(v as i128).value), | |
235 | Float(FloatTy::F32) => Scalar::from_f32(Single::from_u128(v).value), | |
236 | Float(FloatTy::F64) => Scalar::from_f64(Double::from_u128(v).value), | |
ea8adc8c | 237 | |
b7449926 XL |
238 | Char => { |
239 | // `u8` to `char` cast | |
f9f354fc | 240 | Scalar::from_u32(u8::try_from(v).unwrap().into()) |
dfeec247 | 241 | } |
ea8adc8c | 242 | |
0531ce1d | 243 | // Casts to bool are not permitted by rustc, no need to handle them here. |
f035d41b | 244 | _ => span_bug!(self.cur_span(), "invalid int to {:?} cast", cast_ty), |
04454e1e | 245 | }) |
ea8adc8c XL |
246 | } |
247 | ||
064997fb | 248 | fn cast_from_float<F>(&self, f: F, dest_ty: Ty<'tcx>) -> Scalar<M::Provenance> |
dfeec247 | 249 | where |
064997fb | 250 | F: Float + Into<Scalar<M::Provenance>> + FloatConvert<Single> + FloatConvert<Double>, |
dc9dc135 | 251 | { |
923072b8 | 252 | use rustc_type_ir::sty::TyKind::*; |
1b1a35ee | 253 | match *dest_ty.kind() { |
0531ce1d | 254 | // float -> uint |
b7449926 | 255 | Uint(t) => { |
5869c6ff | 256 | let size = Integer::from_uint_ty(self, t).size(); |
ba9703b0 XL |
257 | // `to_u128` is a saturating cast, which is what we need |
258 | // (https://doc.rust-lang.org/nightly/nightly-rustc/rustc_apfloat/trait.Float.html#method.to_i128_r). | |
f9f354fc | 259 | let v = f.to_u128(size.bits_usize()).value; |
b7449926 | 260 | // This should already fit the bit width |
f9f354fc | 261 | Scalar::from_uint(v, size) |
dfeec247 | 262 | } |
0531ce1d | 263 | // float -> int |
b7449926 | 264 | Int(t) => { |
5869c6ff | 265 | let size = Integer::from_int_ty(self, t).size(); |
ba9703b0 XL |
266 | // `to_i128` is a saturating cast, which is what we need |
267 | // (https://doc.rust-lang.org/nightly/nightly-rustc/rustc_apfloat/trait.Float.html#method.to_i128_r). | |
f9f354fc XL |
268 | let v = f.to_i128(size.bits_usize()).value; |
269 | Scalar::from_int(v, size) | |
dfeec247 | 270 | } |
dc9dc135 | 271 | // float -> f32 |
f9f354fc | 272 | Float(FloatTy::F32) => Scalar::from_f32(f.convert(&mut false).value), |
dc9dc135 | 273 | // float -> f64 |
f9f354fc | 274 | Float(FloatTy::F64) => Scalar::from_f64(f.convert(&mut false).value), |
dc9dc135 | 275 | // That's it. |
f035d41b | 276 | _ => span_bug!(self.cur_span(), "invalid float to {:?} cast", dest_ty), |
ea8adc8c XL |
277 | } |
278 | } | |
279 | ||
b7449926 XL |
280 | fn unsize_into_ptr( |
281 | &mut self, | |
064997fb FG |
282 | src: &OpTy<'tcx, M::Provenance>, |
283 | dest: &PlaceTy<'tcx, M::Provenance>, | |
b7449926 | 284 | // The pointee types |
e74abb32 | 285 | source_ty: Ty<'tcx>, |
f9f354fc | 286 | cast_ty: Ty<'tcx>, |
dc9dc135 | 287 | ) -> InterpResult<'tcx> { |
b7449926 | 288 | // A<Struct> -> A<Trait> conversion |
416331ca | 289 | let (src_pointee_ty, dest_pointee_ty) = |
f9f354fc | 290 | self.tcx.struct_lockstep_tails_erasing_lifetimes(source_ty, cast_ty, self.param_env); |
b7449926 | 291 | |
1b1a35ee | 292 | match (&src_pointee_ty.kind(), &dest_pointee_ty.kind()) { |
b7449926 | 293 | (&ty::Array(_, length), &ty::Slice(_)) => { |
60c5eb7d | 294 | let ptr = self.read_immediate(src)?.to_scalar()?; |
b7449926 | 295 | // u64 cast is from usize to u64, which is always good |
f035d41b XL |
296 | let val = |
297 | Immediate::new_slice(ptr, length.eval_usize(*self.tcx, self.param_env), self); | |
a1dfa0c6 | 298 | self.write_immediate(val, dest) |
b7449926 | 299 | } |
94222f64 | 300 | (&ty::Dynamic(ref data_a, ..), &ty::Dynamic(ref data_b, ..)) => { |
064997fb FG |
301 | let (old_data, old_vptr) = self.read_immediate(src)?.to_scalar_pair()?; |
302 | let old_vptr = old_vptr.to_pointer(self)?; | |
303 | let (ty, old_trait) = self.get_ptr_vtable(old_vptr)?; | |
304 | if old_trait != data_a.principal() { | |
305 | throw_ub_format!("upcast on a pointer whose vtable does not match its type"); | |
94222f64 | 306 | } |
064997fb FG |
307 | let new_vptr = self.get_vtable_ptr(ty, data_b.principal())?; |
308 | self.write_immediate(Immediate::new_dyn_trait(old_data, new_vptr, self), dest) | |
b7449926 XL |
309 | } |
310 | (_, &ty::Dynamic(ref data, _)) => { | |
311 | // Initial cast from sized to dyn trait | |
064997fb | 312 | let vtable = self.get_vtable_ptr(src_pointee_ty, data.principal())?; |
60c5eb7d | 313 | let ptr = self.read_immediate(src)?.to_scalar()?; |
136023e0 | 314 | let val = Immediate::new_dyn_trait(ptr, vtable, &*self.tcx); |
a1dfa0c6 | 315 | self.write_immediate(val, dest) |
b7449926 XL |
316 | } |
317 | ||
f035d41b XL |
318 | _ => { |
319 | span_bug!(self.cur_span(), "invalid unsizing {:?} -> {:?}", src.layout.ty, cast_ty) | |
320 | } | |
b7449926 XL |
321 | } |
322 | } | |
323 | ||
324 | fn unsize_into( | |
325 | &mut self, | |
064997fb | 326 | src: &OpTy<'tcx, M::Provenance>, |
f9f354fc | 327 | cast_ty: TyAndLayout<'tcx>, |
064997fb | 328 | dest: &PlaceTy<'tcx, M::Provenance>, |
dc9dc135 | 329 | ) -> InterpResult<'tcx> { |
f9f354fc | 330 | trace!("Unsizing {:?} of type {} into {:?}", *src, src.layout.ty, cast_ty.ty); |
1b1a35ee | 331 | match (&src.layout.ty.kind(), &cast_ty.ty.kind()) { |
f9f354fc XL |
332 | (&ty::Ref(_, s, _), &ty::Ref(_, c, _) | &ty::RawPtr(TypeAndMut { ty: c, .. })) |
333 | | (&ty::RawPtr(TypeAndMut { ty: s, .. }), &ty::RawPtr(TypeAndMut { ty: c, .. })) => { | |
5099ac24 | 334 | self.unsize_into_ptr(src, dest, *s, *c) |
b7449926 XL |
335 | } |
336 | (&ty::Adt(def_a, _), &ty::Adt(def_b, _)) => { | |
337 | assert_eq!(def_a, def_b); | |
b7449926 XL |
338 | |
339 | // unsizing of generic struct with pointer fields | |
340 | // Example: `Arc<T>` -> `Arc<Trait>` | |
341 | // here we need to increase the size of every &T thin ptr field to a fat ptr | |
342 | for i in 0..src.layout.fields.count() { | |
94222f64 | 343 | let cast_ty_field = cast_ty.field(self, i); |
f9f354fc | 344 | if cast_ty_field.is_zst() { |
b7449926 XL |
345 | continue; |
346 | } | |
ba9703b0 | 347 | let src_field = self.operand_field(src, i)?; |
f9f354fc XL |
348 | let dst_field = self.place_field(dest, i)?; |
349 | if src_field.layout.ty == cast_ty_field.ty { | |
064997fb | 350 | self.copy_op(&src_field, &dst_field, /*allow_transmute*/ false)?; |
b7449926 | 351 | } else { |
6a06907d | 352 | self.unsize_into(&src_field, cast_ty_field, &dst_field)?; |
b7449926 XL |
353 | } |
354 | } | |
355 | Ok(()) | |
356 | } | |
f035d41b XL |
357 | _ => span_bug!( |
358 | self.cur_span(), | |
359 | "unsize_into: invalid conversion: {:?} -> {:?}", | |
360 | src.layout, | |
361 | dest.layout | |
362 | ), | |
b7449926 XL |
363 | } |
364 | } | |
ea8adc8c | 365 | } |