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a945c346 | 1 | // Copyright (C) 2020-2024 Free Software Foundation, Inc. |
06688fe4 PH |
2 | |
3 | // This file is part of GCC. | |
4 | ||
5 | // GCC is free software; you can redistribute it and/or modify it under | |
6 | // the terms of the GNU General Public License as published by the Free | |
7 | // Software Foundation; either version 3, or (at your option) any later | |
8 | // version. | |
9 | ||
10 | // GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
11 | // WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
12 | // FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
13 | // for more details. | |
14 | ||
15 | // You should have received a copy of the GNU General Public License | |
16 | // along with GCC; see the file COPYING3. If not see | |
17 | // <http://www.gnu.org/licenses/>. | |
18 | ||
19 | #include "rust-casts.h" | |
20 | ||
21 | namespace Rust { | |
22 | namespace Resolver { | |
23 | ||
d991a3f1 | 24 | TypeCastRules::TypeCastRules (location_t locus, TyTy::TyWithLocation from, |
06688fe4 PH |
25 | TyTy::TyWithLocation to) |
26 | : locus (locus), from (from), to (to) | |
27 | {} | |
28 | ||
29 | TypeCoercionRules::CoercionResult | |
d991a3f1 | 30 | TypeCastRules::resolve (location_t locus, TyTy::TyWithLocation from, |
06688fe4 PH |
31 | TyTy::TyWithLocation to) |
32 | { | |
33 | TypeCastRules cast_rules (locus, from, to); | |
34 | return cast_rules.check (); | |
35 | } | |
36 | ||
37 | TypeCoercionRules::CoercionResult | |
38 | TypeCastRules::check () | |
39 | { | |
40 | // https://github.com/rust-lang/rust/blob/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/compiler/rustc_typeck/src/check/cast.rs#L565-L582 | |
41 | auto possible_coercion | |
e6750011 | 42 | = TypeCoercionRules::TryCoerce (from.get_ty (), to.get_ty (), locus, |
8ae7e93d PH |
43 | true /*allow-autoderef*/, |
44 | true /*is_cast_site*/); | |
06688fe4 | 45 | if (!possible_coercion.is_error ()) |
1b34e40e PH |
46 | { |
47 | // given the attempt was ok we need to ensure we perform it so that any | |
48 | // inference variables are unified correctly | |
49 | return TypeCoercionRules::Coerce (from.get_ty (), to.get_ty (), locus, | |
8ae7e93d PH |
50 | true /*allow-autoderef*/, |
51 | true /*is_cast_site*/); | |
1b34e40e | 52 | } |
06688fe4 PH |
53 | |
54 | // try the simple cast rules | |
55 | auto simple_cast = cast_rules (); | |
56 | if (!simple_cast.is_error ()) | |
57 | return simple_cast; | |
58 | ||
59 | // failed to cast | |
60 | emit_cast_error (); | |
61 | return TypeCoercionRules::CoercionResult::get_error (); | |
62 | } | |
63 | ||
64 | TypeCoercionRules::CoercionResult | |
65 | TypeCastRules::cast_rules () | |
66 | { | |
67 | // https://github.com/rust-lang/rust/blob/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/compiler/rustc_typeck/src/check/cast.rs#L596 | |
68 | // https://github.com/rust-lang/rust/blob/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/compiler/rustc_typeck/src/check/cast.rs#L654 | |
69 | ||
525110ae | 70 | TyTy::BaseType *from_type = from.get_ty ()->destructure (); |
71 | ||
72 | rust_debug ("cast_rules from={%s} to={%s}", from_type->debug_str ().c_str (), | |
06688fe4 | 73 | to.get_ty ()->debug_str ().c_str ()); |
525110ae | 74 | switch (from_type->get_kind ()) |
06688fe4 PH |
75 | { |
76 | case TyTy::TypeKind::INFER: { | |
77 | TyTy::InferType *from_infer | |
525110ae | 78 | = static_cast<TyTy::InferType *> (from_type); |
06688fe4 PH |
79 | switch (from_infer->get_infer_kind ()) |
80 | { | |
81 | case TyTy::InferType::InferTypeKind::GENERAL: | |
82 | return TypeCoercionRules::CoercionResult{{}, | |
83 | to.get_ty ()->clone ()}; | |
84 | ||
85 | case TyTy::InferType::InferTypeKind::INTEGRAL: | |
86 | switch (to.get_ty ()->get_kind ()) | |
87 | { | |
bdb4e293 EM |
88 | case TyTy::TypeKind::CHAR: { |
89 | // only u8 and char | |
90 | bool was_uint | |
91 | = from.get_ty ()->get_kind () == TyTy::TypeKind::UINT; | |
92 | bool was_u8 | |
93 | = was_uint | |
94 | && (static_cast<TyTy::UintType *> (from.get_ty ()) | |
95 | ->get_uint_kind () | |
96 | == TyTy::UintType::UintKind::U8); | |
97 | if (was_u8) | |
98 | return TypeCoercionRules::CoercionResult{ | |
99 | {}, to.get_ty ()->clone ()}; | |
100 | } | |
101 | break; | |
102 | ||
06688fe4 PH |
103 | case TyTy::TypeKind::USIZE: |
104 | case TyTy::TypeKind::ISIZE: | |
105 | case TyTy::TypeKind::UINT: | |
106 | case TyTy::TypeKind::INT: | |
107 | case TyTy::TypeKind::POINTER: | |
108 | return TypeCoercionRules::CoercionResult{ | |
109 | {}, to.get_ty ()->clone ()}; | |
110 | ||
111 | case TyTy::TypeKind::INFER: { | |
112 | TyTy::InferType *to_infer | |
113 | = static_cast<TyTy::InferType *> (to.get_ty ()); | |
114 | ||
115 | switch (to_infer->get_infer_kind ()) | |
116 | { | |
117 | case TyTy::InferType::InferTypeKind::GENERAL: | |
118 | case TyTy::InferType::InferTypeKind::INTEGRAL: | |
119 | return TypeCoercionRules::CoercionResult{ | |
120 | {}, to.get_ty ()->clone ()}; | |
121 | ||
122 | default: | |
123 | return TypeCoercionRules::CoercionResult::get_error (); | |
124 | } | |
125 | } | |
126 | break; | |
127 | ||
128 | default: | |
129 | return TypeCoercionRules::CoercionResult::get_error (); | |
130 | } | |
131 | break; | |
132 | ||
133 | case TyTy::InferType::InferTypeKind::FLOAT: | |
134 | switch (to.get_ty ()->get_kind ()) | |
135 | { | |
136 | case TyTy::TypeKind::USIZE: | |
137 | case TyTy::TypeKind::ISIZE: | |
138 | case TyTy::TypeKind::UINT: | |
139 | case TyTy::TypeKind::INT: | |
140 | return TypeCoercionRules::CoercionResult{ | |
141 | {}, to.get_ty ()->clone ()}; | |
142 | ||
143 | case TyTy::TypeKind::INFER: { | |
144 | TyTy::InferType *to_infer | |
145 | = static_cast<TyTy::InferType *> (to.get_ty ()); | |
146 | ||
147 | switch (to_infer->get_infer_kind ()) | |
148 | { | |
149 | case TyTy::InferType::InferTypeKind::GENERAL: | |
150 | case TyTy::InferType::InferTypeKind::FLOAT: | |
151 | return TypeCoercionRules::CoercionResult{ | |
152 | {}, to.get_ty ()->clone ()}; | |
153 | ||
154 | default: | |
155 | return TypeCoercionRules::CoercionResult::get_error (); | |
156 | } | |
157 | } | |
158 | break; | |
159 | ||
160 | default: | |
161 | return TypeCoercionRules::CoercionResult::get_error (); | |
162 | } | |
163 | break; | |
164 | } | |
165 | } | |
166 | break; | |
167 | ||
168 | case TyTy::TypeKind::BOOL: | |
169 | switch (to.get_ty ()->get_kind ()) | |
170 | { | |
171 | case TyTy::TypeKind::INFER: | |
172 | case TyTy::TypeKind::USIZE: | |
173 | case TyTy::TypeKind::ISIZE: | |
174 | case TyTy::TypeKind::UINT: | |
175 | case TyTy::TypeKind::INT: | |
176 | return TypeCoercionRules::CoercionResult{{}, to.get_ty ()->clone ()}; | |
177 | ||
178 | default: | |
179 | return TypeCoercionRules::CoercionResult::get_error (); | |
180 | } | |
181 | break; | |
182 | ||
183 | case TyTy::TypeKind::CHAR: | |
184 | case TyTy::TypeKind::USIZE: | |
185 | case TyTy::TypeKind::ISIZE: | |
186 | case TyTy::TypeKind::UINT: | |
187 | case TyTy::TypeKind::INT: | |
188 | switch (to.get_ty ()->get_kind ()) | |
189 | { | |
190 | case TyTy::TypeKind::CHAR: { | |
191 | // only u8 and char | |
192 | bool was_uint = from.get_ty ()->get_kind () == TyTy::TypeKind::UINT; | |
193 | bool was_u8 = was_uint | |
194 | && (static_cast<TyTy::UintType *> (from.get_ty ()) | |
195 | ->get_uint_kind () | |
196 | == TyTy::UintType::UintKind::U8); | |
197 | if (was_u8) | |
198 | return TypeCoercionRules::CoercionResult{{}, | |
199 | to.get_ty ()->clone ()}; | |
200 | } | |
201 | break; | |
202 | ||
203 | case TyTy::TypeKind::INFER: | |
204 | case TyTy::TypeKind::USIZE: | |
205 | case TyTy::TypeKind::ISIZE: | |
206 | case TyTy::TypeKind::UINT: | |
207 | case TyTy::TypeKind::INT: | |
208 | return TypeCoercionRules::CoercionResult{{}, to.get_ty ()->clone ()}; | |
209 | ||
210 | default: | |
211 | return TypeCoercionRules::CoercionResult::get_error (); | |
212 | } | |
213 | break; | |
214 | ||
215 | case TyTy::TypeKind::FLOAT: | |
216 | switch (to.get_ty ()->get_kind ()) | |
217 | { | |
218 | case TyTy::TypeKind::FLOAT: | |
219 | return TypeCoercionRules::CoercionResult{{}, to.get_ty ()->clone ()}; | |
220 | ||
221 | case TyTy::TypeKind::INFER: { | |
222 | TyTy::InferType *to_infer | |
223 | = static_cast<TyTy::InferType *> (to.get_ty ()); | |
224 | ||
225 | switch (to_infer->get_infer_kind ()) | |
226 | { | |
227 | case TyTy::InferType::InferTypeKind::GENERAL: | |
228 | case TyTy::InferType::InferTypeKind::FLOAT: | |
229 | return TypeCoercionRules::CoercionResult{ | |
230 | {}, to.get_ty ()->clone ()}; | |
231 | ||
232 | default: | |
233 | return TypeCoercionRules::CoercionResult::get_error (); | |
234 | } | |
235 | } | |
236 | break; | |
237 | ||
238 | default: | |
239 | return TypeCoercionRules::CoercionResult::get_error (); | |
240 | } | |
241 | break; | |
242 | ||
243 | case TyTy::TypeKind::REF: | |
244 | case TyTy::TypeKind::POINTER: | |
245 | switch (to.get_ty ()->get_kind ()) | |
246 | { | |
247 | case TyTy::TypeKind::REF: | |
248 | case TyTy::TypeKind::POINTER: | |
249 | return check_ptr_ptr_cast (); | |
250 | ||
251 | // FIXME can you cast a pointer to a integral type? | |
252 | ||
253 | default: | |
254 | return TypeCoercionRules::CoercionResult::get_error (); | |
255 | } | |
256 | break; | |
257 | ||
258 | default: | |
259 | return TypeCoercionRules::CoercionResult::get_error (); | |
260 | } | |
261 | ||
262 | return TypeCoercionRules::CoercionResult::get_error (); | |
263 | } | |
264 | ||
265 | TypeCoercionRules::CoercionResult | |
266 | TypeCastRules::check_ptr_ptr_cast () | |
267 | { | |
268 | rust_debug ("check_ptr_ptr_cast from={%s} to={%s}", | |
269 | from.get_ty ()->debug_str ().c_str (), | |
270 | to.get_ty ()->debug_str ().c_str ()); | |
271 | ||
272 | bool from_is_ref = from.get_ty ()->get_kind () == TyTy::TypeKind::REF; | |
273 | bool to_is_ref = to.get_ty ()->get_kind () == TyTy::TypeKind::REF; | |
274 | bool from_is_ptr = from.get_ty ()->get_kind () == TyTy::TypeKind::POINTER; | |
275 | bool to_is_ptr = to.get_ty ()->get_kind () == TyTy::TypeKind::POINTER; | |
276 | ||
277 | if (from_is_ptr && to_is_ptr) | |
278 | { | |
279 | // mutability is ignored here as all pointer usage requires unsafe | |
280 | return TypeCoercionRules::CoercionResult{{}, to.get_ty ()->clone ()}; | |
281 | } | |
282 | else if (from_is_ref && to_is_ref) | |
283 | { | |
284 | // mutability must be coercedable | |
285 | TyTy::ReferenceType &f | |
286 | = static_cast<TyTy::ReferenceType &> (*from.get_ty ()); | |
287 | TyTy::ReferenceType &t | |
288 | = static_cast<TyTy::ReferenceType &> (*to.get_ty ()); | |
289 | ||
290 | if (TypeCoercionRules::coerceable_mutability (f.mutability (), | |
291 | t.mutability ())) | |
292 | { | |
293 | return TypeCoercionRules::CoercionResult{{}, to.get_ty ()->clone ()}; | |
294 | } | |
295 | } | |
296 | ||
297 | return TypeCoercionRules::CoercionResult::get_error (); | |
298 | } | |
299 | ||
300 | void | |
301 | TypeCastRules::emit_cast_error () const | |
302 | { | |
ffadba42 | 303 | rich_location r (line_table, locus); |
06688fe4 PH |
304 | r.add_range (from.get_locus ()); |
305 | r.add_range (to.get_locus ()); | |
2952785b MM |
306 | ErrorCode error_code; |
307 | std::string error_msg; | |
308 | switch (to.get_ty ()->get_kind ()) | |
309 | { | |
310 | case TyTy::TypeKind::BOOL: | |
311 | error_msg = "cannot cast %qs as %qs"; | |
312 | error_code = ErrorCode::E0054; | |
313 | break; | |
314 | case TyTy::TypeKind::CHAR: | |
315 | error_msg | |
316 | += "cannot cast %qs as %qs, only %<u8%> can be cast as %<char%>"; | |
317 | error_code = ErrorCode::E0604; | |
318 | break; | |
319 | case TyTy::TypeKind::SLICE: | |
320 | error_msg = "cast to unsized type: %qs as %qs"; | |
321 | error_code = ErrorCode::E0620; | |
322 | break; | |
323 | ||
324 | default: | |
325 | error_msg = "casting %qs as %qs is invalid"; | |
326 | error_code = ErrorCode::E0606; | |
327 | break; | |
328 | } | |
329 | rust_error_at (r, error_code, error_msg.c_str (), | |
06688fe4 PH |
330 | from.get_ty ()->get_name ().c_str (), |
331 | to.get_ty ()->get_name ().c_str ()); | |
332 | } | |
333 | ||
334 | } // namespace Resolver | |
1b34e40e | 335 | } // namespace Rust |