1 //===-------------- TypeOrdering.h - Total ordering for types ---*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 ///
9 /// \file
10 /// Allows QualTypes to be sorted and hence used in maps and sets.
11 ///
12 /// Defines clang::QualTypeOrdering, a total ordering on clang::QualType,
13 /// and hence enables QualType values to be sorted and to be used in
14 /// std::maps, std::sets, llvm::DenseMaps, and llvm::DenseSets.
15 ///
16 //===----------------------------------------------------------------------===//
17 
18 #ifndef LLVM_CLANG_AST_TYPEORDERING_H
19 #define LLVM_CLANG_AST_TYPEORDERING_H
20 
21 #include "clang/AST/CanonicalType.h"
22 #include "clang/AST/Type.h"
23 #include <functional>
24 
25 namespace clang {
26 
27 /// Function object that provides a total ordering on QualType values.
28 struct QualTypeOrdering {
operatorQualTypeOrdering29   bool operator()(QualType T1, QualType T2) const {
30     return std::less<void*>()(T1.getAsOpaquePtr(), T2.getAsOpaquePtr());
31   }
32 };
33 
34 }
35 
36 namespace llvm {
37 
38   template<> struct DenseMapInfo<clang::QualType> {
39     static inline clang::QualType getEmptyKey() { return clang::QualType(); }
40 
41     static inline clang::QualType getTombstoneKey() {
42       using clang::QualType;
43       return QualType::getFromOpaquePtr(reinterpret_cast<clang::Type *>(-1));
44     }
45 
46     static unsigned getHashValue(clang::QualType Val) {
47       return (unsigned)((uintptr_t)Val.getAsOpaquePtr()) ^
48             ((unsigned)((uintptr_t)Val.getAsOpaquePtr() >> 9));
49     }
50 
51     static bool isEqual(clang::QualType LHS, clang::QualType RHS) {
52       return LHS == RHS;
53     }
54   };
55 
56   template<> struct DenseMapInfo<clang::CanQualType> {
57     static inline clang::CanQualType getEmptyKey() {
58       return clang::CanQualType();
59     }
60 
61     static inline clang::CanQualType getTombstoneKey() {
62       using clang::CanQualType;
63       return CanQualType::getFromOpaquePtr(reinterpret_cast<clang::Type *>(-1));
64     }
65 
66     static unsigned getHashValue(clang::CanQualType Val) {
67       return (unsigned)((uintptr_t)Val.getAsOpaquePtr()) ^
68       ((unsigned)((uintptr_t)Val.getAsOpaquePtr() >> 9));
69     }
70 
71     static bool isEqual(clang::CanQualType LHS, clang::CanQualType RHS) {
72       return LHS == RHS;
73     }
74   };
75 }
76 
77 #endif
78