1 //===--- Builtins.h - Builtin function header -------------------*- 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 /// Defines enum values for all the target-independent builtin 11 /// functions. 12 /// 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_CLANG_BASIC_BUILTINS_H 16 #define LLVM_CLANG_BASIC_BUILTINS_H 17 18 #include "llvm/ADT/ArrayRef.h" 19 #include <cstring> 20 21 // VC++ defines 'alloca' as an object-like macro, which interferes with our 22 // builtins. 23 #undef alloca 24 25 namespace clang { 26 class TargetInfo; 27 class IdentifierTable; 28 class LangOptions; 29 30 enum LanguageID { 31 GNU_LANG = 0x1, // builtin requires GNU mode. 32 C_LANG = 0x2, // builtin for c only. 33 CXX_LANG = 0x4, // builtin for cplusplus only. 34 OBJC_LANG = 0x8, // builtin for objective-c and objective-c++ 35 MS_LANG = 0x10, // builtin requires MS mode. 36 OCLC20_LANG = 0x20, // builtin for OpenCL C 2.0 only. 37 OCLC1X_LANG = 0x40, // builtin for OpenCL C 1.x only. 38 OMP_LANG = 0x80, // builtin requires OpenMP. 39 ALL_LANGUAGES = C_LANG | CXX_LANG | OBJC_LANG, // builtin for all languages. 40 ALL_GNU_LANGUAGES = ALL_LANGUAGES | GNU_LANG, // builtin requires GNU mode. 41 ALL_MS_LANGUAGES = ALL_LANGUAGES | MS_LANG, // builtin requires MS mode. 42 ALL_OCLC_LANGUAGES = OCLC1X_LANG | OCLC20_LANG // builtin for OCLC languages. 43 }; 44 45 namespace Builtin { 46 enum ID { 47 NotBuiltin = 0, // This is not a builtin function. 48 #define BUILTIN(ID, TYPE, ATTRS) BI##ID, 49 #include "clang/Basic/Builtins.def" 50 FirstTSBuiltin 51 }; 52 53 struct Info { 54 const char *Name, *Type, *Attributes, *HeaderName; 55 LanguageID Langs; 56 const char *Features; 57 }; 58 59 /// Holds information about both target-independent and 60 /// target-specific builtins, allowing easy queries by clients. 61 /// 62 /// Builtins from an optional auxiliary target are stored in 63 /// AuxTSRecords. Their IDs are shifted up by TSRecords.size() and need to 64 /// be translated back with getAuxBuiltinID() before use. 65 class Context { 66 llvm::ArrayRef<Info> TSRecords; 67 llvm::ArrayRef<Info> AuxTSRecords; 68 69 public: 70 Context() {} 71 72 /// Perform target-specific initialization 73 /// \param AuxTarget Target info to incorporate builtins from. May be nullptr. 74 void InitializeTarget(const TargetInfo &Target, const TargetInfo *AuxTarget); 75 76 /// Mark the identifiers for all the builtins with their 77 /// appropriate builtin ID # and mark any non-portable builtin identifiers as 78 /// such. 79 void initializeBuiltins(IdentifierTable &Table, const LangOptions& LangOpts); 80 81 /// Return the identifier name for the specified builtin, 82 /// e.g. "__builtin_abs". 83 const char *getName(unsigned ID) const { 84 return getRecord(ID).Name; 85 } 86 87 /// Get the type descriptor string for the specified builtin. 88 const char *getTypeString(unsigned ID) const { 89 return getRecord(ID).Type; 90 } 91 92 /// Return true if this function is a target-specific builtin. 93 bool isTSBuiltin(unsigned ID) const { 94 return ID >= Builtin::FirstTSBuiltin; 95 } 96 97 /// Return true if this function has no side effects. 98 bool isPure(unsigned ID) const { 99 return strchr(getRecord(ID).Attributes, 'U') != nullptr; 100 } 101 102 /// Return true if this function has no side effects and doesn't 103 /// read memory. 104 bool isConst(unsigned ID) const { 105 return strchr(getRecord(ID).Attributes, 'c') != nullptr; 106 } 107 108 /// Return true if we know this builtin never throws an exception. 109 bool isNoThrow(unsigned ID) const { 110 return strchr(getRecord(ID).Attributes, 'n') != nullptr; 111 } 112 113 /// Return true if we know this builtin never returns. 114 bool isNoReturn(unsigned ID) const { 115 return strchr(getRecord(ID).Attributes, 'r') != nullptr; 116 } 117 118 /// Return true if we know this builtin can return twice. 119 bool isReturnsTwice(unsigned ID) const { 120 return strchr(getRecord(ID).Attributes, 'j') != nullptr; 121 } 122 123 /// Returns true if this builtin does not perform the side-effects 124 /// of its arguments. 125 bool isUnevaluated(unsigned ID) const { 126 return strchr(getRecord(ID).Attributes, 'u') != nullptr; 127 } 128 129 /// Return true if this is a builtin for a libc/libm function, 130 /// with a "__builtin_" prefix (e.g. __builtin_abs). 131 bool isLibFunction(unsigned ID) const { 132 return strchr(getRecord(ID).Attributes, 'F') != nullptr; 133 } 134 135 /// Determines whether this builtin is a predefined libc/libm 136 /// function, such as "malloc", where we know the signature a 137 /// priori. 138 bool isPredefinedLibFunction(unsigned ID) const { 139 return strchr(getRecord(ID).Attributes, 'f') != nullptr; 140 } 141 142 /// Returns true if this builtin requires appropriate header in other 143 /// compilers. In Clang it will work even without including it, but we can emit 144 /// a warning about missing header. 145 bool isHeaderDependentFunction(unsigned ID) const { 146 return strchr(getRecord(ID).Attributes, 'h') != nullptr; 147 } 148 149 /// Determines whether this builtin is a predefined compiler-rt/libgcc 150 /// function, such as "__clear_cache", where we know the signature a 151 /// priori. 152 bool isPredefinedRuntimeFunction(unsigned ID) const { 153 return strchr(getRecord(ID).Attributes, 'i') != nullptr; 154 } 155 156 /// Determines whether this builtin has custom typechecking. 157 bool hasCustomTypechecking(unsigned ID) const { 158 return strchr(getRecord(ID).Attributes, 't') != nullptr; 159 } 160 161 /// Determines whether this builtin has a result or any arguments which 162 /// are pointer types. 163 bool hasPtrArgsOrResult(unsigned ID) const { 164 return strchr(getRecord(ID).Type, '*') != nullptr; 165 } 166 167 /// Return true if this builtin has a result or any arguments which are 168 /// reference types. 169 bool hasReferenceArgsOrResult(unsigned ID) const { 170 return strchr(getRecord(ID).Type, '&') != nullptr || 171 strchr(getRecord(ID).Type, 'A') != nullptr; 172 } 173 174 /// Completely forget that the given ID was ever considered a builtin, 175 /// e.g., because the user provided a conflicting signature. 176 void forgetBuiltin(unsigned ID, IdentifierTable &Table); 177 178 /// If this is a library function that comes from a specific 179 /// header, retrieve that header name. 180 const char *getHeaderName(unsigned ID) const { 181 return getRecord(ID).HeaderName; 182 } 183 184 /// Determine whether this builtin is like printf in its 185 /// formatting rules and, if so, set the index to the format string 186 /// argument and whether this function as a va_list argument. 187 bool isPrintfLike(unsigned ID, unsigned &FormatIdx, bool &HasVAListArg); 188 189 /// Determine whether this builtin is like scanf in its 190 /// formatting rules and, if so, set the index to the format string 191 /// argument and whether this function as a va_list argument. 192 bool isScanfLike(unsigned ID, unsigned &FormatIdx, bool &HasVAListArg); 193 194 /// Determine whether this builtin has callback behavior (see 195 /// llvm::AbstractCallSites for details). If so, add the index to the 196 /// callback callee argument and the callback payload arguments. 197 bool performsCallback(unsigned ID, 198 llvm::SmallVectorImpl<int> &Encoding) const; 199 200 /// Return true if this function has no side effects and doesn't 201 /// read memory, except for possibly errno. 202 /// 203 /// Such functions can be const when the MathErrno lang option is disabled. 204 bool isConstWithoutErrno(unsigned ID) const { 205 return strchr(getRecord(ID).Attributes, 'e') != nullptr; 206 } 207 208 const char *getRequiredFeatures(unsigned ID) const { 209 return getRecord(ID).Features; 210 } 211 212 unsigned getRequiredVectorWidth(unsigned ID) const; 213 214 /// Return true if builtin ID belongs to AuxTarget. 215 bool isAuxBuiltinID(unsigned ID) const { 216 return ID >= (Builtin::FirstTSBuiltin + TSRecords.size()); 217 } 218 219 /// Return real builtin ID (i.e. ID it would have during compilation 220 /// for AuxTarget). 221 unsigned getAuxBuiltinID(unsigned ID) const { return ID - TSRecords.size(); } 222 223 /// Returns true if this is a libc/libm function without the '__builtin_' 224 /// prefix. 225 static bool isBuiltinFunc(llvm::StringRef Name); 226 227 /// Returns true if this is a builtin that can be redeclared. Returns true 228 /// for non-builtins. 229 bool canBeRedeclared(unsigned ID) const; 230 231 private: 232 const Info &getRecord(unsigned ID) const; 233 234 /// Is this builtin supported according to the given language options? 235 bool builtinIsSupported(const Builtin::Info &BuiltinInfo, 236 const LangOptions &LangOpts); 237 238 /// Helper function for isPrintfLike and isScanfLike. 239 bool isLike(unsigned ID, unsigned &FormatIdx, bool &HasVAListArg, 240 const char *Fmt) const; 241 }; 242 243 } 244 245 /// Kinds of BuiltinTemplateDecl. 246 enum BuiltinTemplateKind : int { 247 /// This names the __make_integer_seq BuiltinTemplateDecl. 248 BTK__make_integer_seq, 249 250 /// This names the __type_pack_element BuiltinTemplateDecl. 251 BTK__type_pack_element 252 }; 253 254 } // end namespace clang 255 #endif 256