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1 | // Copyright 2015 The Rust Project Developers. See the COPYRIGHT |
2 | // file at the top-level directory of this distribution and at | |
3 | // http://rust-lang.org/COPYRIGHT. | |
4 | // | |
5 | // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or | |
6 | // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license | |
7 | // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your | |
8 | // option. This file may not be copied, modified, or distributed | |
9 | // except according to those terms. | |
10 | ||
11 | // Helpers for handling cast expressions, used in both | |
12 | // typeck and trans. | |
13 | ||
14 | use middle::ty::{self, Ty}; | |
15 | ||
b039eaaf | 16 | use syntax::ast; |
62682a34 SL |
17 | |
18 | /// Types that are represented as ints. | |
19 | #[derive(Copy, Clone, Debug, PartialEq, Eq)] | |
20 | pub enum IntTy { | |
21 | U(ast::UintTy), | |
22 | I, | |
23 | CEnum, | |
24 | Bool, | |
25 | Char | |
26 | } | |
27 | ||
28 | // Valid types for the result of a non-coercion cast | |
29 | #[derive(Copy, Clone, Debug, PartialEq, Eq)] | |
30 | pub enum CastTy<'tcx> { | |
31 | /// Various types that are represented as ints and handled mostly | |
32 | /// in the same way, merged for easier matching. | |
33 | Int(IntTy), | |
34 | /// Floating-Point types | |
35 | Float, | |
36 | /// Function Pointers | |
37 | FnPtr, | |
38 | /// Raw pointers | |
c1a9b12d | 39 | Ptr(&'tcx ty::TypeAndMut<'tcx>), |
62682a34 | 40 | /// References |
c1a9b12d | 41 | RPtr(&'tcx ty::TypeAndMut<'tcx>), |
62682a34 SL |
42 | } |
43 | ||
44 | /// Cast Kind. See RFC 401 (or librustc_typeck/check/cast.rs) | |
45 | #[derive(Copy, Clone, Debug, RustcEncodable, RustcDecodable)] | |
46 | pub enum CastKind { | |
47 | CoercionCast, | |
48 | PtrPtrCast, | |
49 | PtrAddrCast, | |
50 | AddrPtrCast, | |
51 | NumericCast, | |
52 | EnumCast, | |
53 | PrimIntCast, | |
54 | U8CharCast, | |
55 | ArrayPtrCast, | |
56 | FnPtrPtrCast, | |
57 | FnPtrAddrCast | |
58 | } | |
59 | ||
60 | impl<'tcx> CastTy<'tcx> { | |
e9174d1e | 61 | pub fn from_ty(t: Ty<'tcx>) -> Option<CastTy<'tcx>> { |
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62 | match t.sty { |
63 | ty::TyBool => Some(CastTy::Int(IntTy::Bool)), | |
64 | ty::TyChar => Some(CastTy::Int(IntTy::Char)), | |
65 | ty::TyInt(_) => Some(CastTy::Int(IntTy::I)), | |
66 | ty::TyUint(u) => Some(CastTy::Int(IntTy::U(u))), | |
67 | ty::TyFloat(_) => Some(CastTy::Float), | |
e9174d1e | 68 | ty::TyEnum(d,_) if d.is_payloadfree() => |
c1a9b12d | 69 | Some(CastTy::Int(IntTy::CEnum)), |
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70 | ty::TyRawPtr(ref mt) => Some(CastTy::Ptr(mt)), |
71 | ty::TyRef(_, ref mt) => Some(CastTy::RPtr(mt)), | |
72 | ty::TyBareFn(..) => Some(CastTy::FnPtr), | |
73 | _ => None, | |
74 | } | |
75 | } | |
76 | } |