1 //===-------------- TypeOrdering.h - Total ordering for types -------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 ///
10 /// \file
11 /// \brief Allows QualTypes to be sorted and hence used in maps and sets.
12 ///
13 /// Defines clang::QualTypeOrdering, a total ordering on clang::QualType,
14 /// and hence enables QualType values to be sorted and to be used in
15 /// std::maps, std::sets, llvm::DenseMaps, and llvm::DenseSets.
16 ///
17 //===----------------------------------------------------------------------===//
18 
19 #ifndef LLVM_CLANG_AST_TYPEORDERING_H
20 #define LLVM_CLANG_AST_TYPEORDERING_H
21 
22 #include "clang/AST/CanonicalType.h"
23 #include "clang/AST/Type.h"
24 #include <functional>
25 
26 namespace clang {
27 
28 /// \brief Function object that provides a total ordering on QualType values.
29 struct QualTypeOrdering : std::binary_function<QualType, QualType, bool> {
operatorQualTypeOrdering30   bool operator()(QualType T1, QualType T2) const {
31     return std::less<void*>()(T1.getAsOpaquePtr(), T2.getAsOpaquePtr());
32   }
33 };
34 
35 }
36 
37 namespace llvm {
38   template<class> struct DenseMapInfo;
39 
40   template<> struct DenseMapInfo<clang::QualType> {
41     static inline clang::QualType getEmptyKey() { return clang::QualType(); }
42 
43     static inline clang::QualType getTombstoneKey() {
44       using clang::QualType;
45       return QualType::getFromOpaquePtr(reinterpret_cast<clang::Type *>(-1));
46     }
47 
48     static unsigned getHashValue(clang::QualType Val) {
49       return (unsigned)((uintptr_t)Val.getAsOpaquePtr()) ^
50             ((unsigned)((uintptr_t)Val.getAsOpaquePtr() >> 9));
51     }
52 
53     static bool isEqual(clang::QualType LHS, clang::QualType RHS) {
54       return LHS == RHS;
55     }
56   };
57 
58   template<> struct DenseMapInfo<clang::CanQualType> {
59     static inline clang::CanQualType getEmptyKey() {
60       return clang::CanQualType();
61     }
62 
63     static inline clang::CanQualType getTombstoneKey() {
64       using clang::CanQualType;
65       return CanQualType::getFromOpaquePtr(reinterpret_cast<clang::Type *>(-1));
66     }
67 
68     static unsigned getHashValue(clang::CanQualType Val) {
69       return (unsigned)((uintptr_t)Val.getAsOpaquePtr()) ^
70       ((unsigned)((uintptr_t)Val.getAsOpaquePtr() >> 9));
71     }
72 
73     static bool isEqual(clang::CanQualType LHS, clang::CanQualType RHS) {
74       return LHS == RHS;
75     }
76   };
77 }
78 
79 #endif
80