1 //===--- StandardLibrary.h --------------------------------------*- 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 /// Provides an interface for querying information about C and C++ Standard 11 /// Library headers and symbols. 12 /// 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_CLANG_TOOLING_INCLUSIONS_STANDARDLIBRARY_H 16 #define LLVM_CLANG_TOOLING_INCLUSIONS_STANDARDLIBRARY_H 17 18 #include "llvm/ADT/DenseMap.h" 19 #include "llvm/ADT/Hashing.h" 20 #include "llvm/ADT/StringRef.h" 21 #include "llvm/Support/raw_ostream.h" 22 #include <optional> 23 #include <string> 24 25 namespace clang { 26 class Decl; 27 class NamespaceDecl; 28 class DeclContext; 29 namespace tooling { 30 namespace stdlib { 31 32 class Symbol; 33 34 // A standard library header, such as <iostream> 35 // Lightweight class, in fact just an index into a table. 36 // C++ and C Library compatibility headers are considered different: e.g. 37 // "<cstdio>" and "<stdio.h>" (and their symbols) are treated differently. 38 class Header { 39 public: 40 // Name should contain the angle brackets, e.g. "<vector>". 41 static std::optional<Header> named(llvm::StringRef Name); 42 43 friend llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const Header &H) { 44 return OS << H.name(); 45 } 46 llvm::StringRef name() const; 47 48 private: 49 Header(unsigned ID) : ID(ID) {} 50 unsigned ID; 51 friend Symbol; 52 friend llvm::DenseMapInfo<Header>; 53 friend bool operator==(const Header &L, const Header &R) { 54 return L.ID == R.ID; 55 } 56 }; 57 58 // A top-level standard library symbol, such as std::vector 59 // Lightweight class, in fact just an index into a table. 60 // C++ and C Standard Library symbols are considered distinct: e.g. std::printf 61 // and ::printf are not treated as the same symbol. 62 // The symbols do not contain macros right now, we don't have a reliable index 63 // for them. 64 class Symbol { 65 public: 66 /// \p Scope should have the trailing "::", for example: 67 /// named("std::chrono::", "system_clock") 68 static std::optional<Symbol> named(llvm::StringRef Scope, 69 llvm::StringRef Name); 70 71 friend llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const Symbol &S) { 72 return OS << S.scope() << S.name(); 73 } 74 llvm::StringRef scope() const; 75 llvm::StringRef name() const; 76 // The preferred header for this symbol (e.g. the suggested insertion). 77 Header header() const; 78 // Some symbols may be provided by multiple headers. 79 llvm::SmallVector<Header> headers() const; 80 81 private: 82 Symbol(unsigned ID) : ID(ID) {} 83 unsigned ID; 84 friend class Recognizer; 85 friend llvm::DenseMapInfo<Symbol>; 86 friend bool operator==(const Symbol &L, const Symbol &R) { 87 return L.ID == R.ID; 88 } 89 }; 90 91 // A functor to find the stdlib::Symbol associated with a decl. 92 // 93 // For non-top-level decls (std::vector<int>::iterator), returns the top-level 94 // symbol (std::vector). 95 class Recognizer { 96 public: 97 Recognizer(); 98 std::optional<Symbol> operator()(const Decl *D); 99 100 private: 101 using NSSymbolMap = llvm::DenseMap<llvm::StringRef, unsigned>; 102 NSSymbolMap *namespaceSymbols(const NamespaceDecl *D); 103 llvm::DenseMap<const DeclContext *, NSSymbolMap *> NamespaceCache; 104 }; 105 106 } // namespace stdlib 107 } // namespace tooling 108 } // namespace clang 109 110 namespace llvm { 111 112 template <> struct DenseMapInfo<clang::tooling::stdlib::Header> { 113 static inline clang::tooling::stdlib::Header getEmptyKey() { 114 return clang::tooling::stdlib::Header(-1); 115 } 116 static inline clang::tooling::stdlib::Header getTombstoneKey() { 117 return clang::tooling::stdlib::Header(-2); 118 } 119 static unsigned getHashValue(const clang::tooling::stdlib::Header &H) { 120 return hash_value(H.ID); 121 } 122 static bool isEqual(const clang::tooling::stdlib::Header &LHS, 123 const clang::tooling::stdlib::Header &RHS) { 124 return LHS == RHS; 125 } 126 }; 127 128 template <> struct DenseMapInfo<clang::tooling::stdlib::Symbol> { 129 static inline clang::tooling::stdlib::Symbol getEmptyKey() { 130 return clang::tooling::stdlib::Symbol(-1); 131 } 132 static inline clang::tooling::stdlib::Symbol getTombstoneKey() { 133 return clang::tooling::stdlib::Symbol(-2); 134 } 135 static unsigned getHashValue(const clang::tooling::stdlib::Symbol &S) { 136 return hash_value(S.ID); 137 } 138 static bool isEqual(const clang::tooling::stdlib::Symbol &LHS, 139 const clang::tooling::stdlib::Symbol &RHS) { 140 return LHS == RHS; 141 } 142 }; 143 } // namespace llvm 144 145 #endif // LLVM_CLANG_TOOLING_INCLUSIONS_STANDARDLIBRARY_H 146