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 "llvm/ADT/StringMap.h" 20 #include "llvm/ADT/StringRef.h" 21 #include <cstring> 22 23 // VC++ defines 'alloca' as an object-like macro, which interferes with our 24 // builtins. 25 #undef alloca 26 27 namespace clang { 28 class TargetInfo; 29 class IdentifierTable; 30 class LangOptions; 31 32 enum LanguageID { 33 GNU_LANG = 0x1, // builtin requires GNU mode. 34 C_LANG = 0x2, // builtin for c only. 35 CXX_LANG = 0x4, // builtin for cplusplus only. 36 OBJC_LANG = 0x8, // builtin for objective-c and objective-c++ 37 MS_LANG = 0x10, // builtin requires MS mode. 38 OMP_LANG = 0x20, // builtin requires OpenMP. 39 CUDA_LANG = 0x40, // builtin requires CUDA. 40 COR_LANG = 0x80, // builtin requires use of 'fcoroutine-ts' option. 41 OCL_GAS = 0x100, // builtin requires OpenCL generic address space. 42 OCL_PIPE = 0x200, // builtin requires OpenCL pipe. 43 OCL_DSE = 0x400, // builtin requires OpenCL device side enqueue. 44 ALL_OCL_LANGUAGES = 0x800, // builtin for OCL languages. 45 HLSL_LANG = 0x1000, // builtin requires HLSL. 46 ALL_LANGUAGES = C_LANG | CXX_LANG | OBJC_LANG, // builtin for all languages. 47 ALL_GNU_LANGUAGES = ALL_LANGUAGES | GNU_LANG, // builtin requires GNU mode. 48 ALL_MS_LANGUAGES = ALL_LANGUAGES | MS_LANG // builtin requires MS mode. 49 }; 50 51 namespace Builtin { 52 enum ID { 53 NotBuiltin = 0, // This is not a builtin function. 54 #define BUILTIN(ID, TYPE, ATTRS) BI##ID, 55 #include "clang/Basic/Builtins.def" 56 FirstTSBuiltin 57 }; 58 59 struct Info { 60 const char *Name, *Type, *Attributes, *HeaderName; 61 LanguageID Langs; 62 const char *Features; 63 }; 64 65 /// Holds information about both target-independent and 66 /// target-specific builtins, allowing easy queries by clients. 67 /// 68 /// Builtins from an optional auxiliary target are stored in 69 /// AuxTSRecords. Their IDs are shifted up by TSRecords.size() and need to 70 /// be translated back with getAuxBuiltinID() before use. 71 class Context { 72 llvm::ArrayRef<Info> TSRecords; 73 llvm::ArrayRef<Info> AuxTSRecords; 74 75 public: 76 Context() = default; 77 78 /// Perform target-specific initialization 79 /// \param AuxTarget Target info to incorporate builtins from. May be nullptr. 80 void InitializeTarget(const TargetInfo &Target, const TargetInfo *AuxTarget); 81 82 /// Mark the identifiers for all the builtins with their 83 /// appropriate builtin ID # and mark any non-portable builtin identifiers as 84 /// such. 85 void initializeBuiltins(IdentifierTable &Table, const LangOptions& LangOpts); 86 87 /// Return the identifier name for the specified builtin, 88 /// e.g. "__builtin_abs". 89 const char *getName(unsigned ID) const { 90 return getRecord(ID).Name; 91 } 92 93 /// Get the type descriptor string for the specified builtin. 94 const char *getTypeString(unsigned ID) const { 95 return getRecord(ID).Type; 96 } 97 98 /// Return true if this function is a target-specific builtin. 99 bool isTSBuiltin(unsigned ID) const { 100 return ID >= Builtin::FirstTSBuiltin; 101 } 102 103 /// Return true if this function has no side effects. 104 bool isPure(unsigned ID) const { 105 return strchr(getRecord(ID).Attributes, 'U') != nullptr; 106 } 107 108 /// Return true if this function has no side effects and doesn't 109 /// read memory. 110 bool isConst(unsigned ID) const { 111 return strchr(getRecord(ID).Attributes, 'c') != nullptr; 112 } 113 114 /// Return true if we know this builtin never throws an exception. 115 bool isNoThrow(unsigned ID) const { 116 return strchr(getRecord(ID).Attributes, 'n') != nullptr; 117 } 118 119 /// Return true if we know this builtin never returns. 120 bool isNoReturn(unsigned ID) const { 121 return strchr(getRecord(ID).Attributes, 'r') != nullptr; 122 } 123 124 /// Return true if we know this builtin can return twice. 125 bool isReturnsTwice(unsigned ID) const { 126 return strchr(getRecord(ID).Attributes, 'j') != nullptr; 127 } 128 129 /// Returns true if this builtin does not perform the side-effects 130 /// of its arguments. 131 bool isUnevaluated(unsigned ID) const { 132 return strchr(getRecord(ID).Attributes, 'u') != nullptr; 133 } 134 135 /// Return true if this is a builtin for a libc/libm function, 136 /// with a "__builtin_" prefix (e.g. __builtin_abs). 137 bool isLibFunction(unsigned ID) const { 138 return strchr(getRecord(ID).Attributes, 'F') != nullptr; 139 } 140 141 /// Determines whether this builtin is a predefined libc/libm 142 /// function, such as "malloc", where we know the signature a 143 /// priori. 144 /// In C, such functions behave as if they are predeclared, 145 /// possibly with a warning on first use. In Objective-C and C++, 146 /// they do not, but they are recognized as builtins once we see 147 /// a declaration. 148 bool isPredefinedLibFunction(unsigned ID) const { 149 return strchr(getRecord(ID).Attributes, 'f') != nullptr; 150 } 151 152 /// Returns true if this builtin requires appropriate header in other 153 /// compilers. In Clang it will work even without including it, but we can emit 154 /// a warning about missing header. 155 bool isHeaderDependentFunction(unsigned ID) const { 156 return strchr(getRecord(ID).Attributes, 'h') != nullptr; 157 } 158 159 /// Determines whether this builtin is a predefined compiler-rt/libgcc 160 /// function, such as "__clear_cache", where we know the signature a 161 /// priori. 162 bool isPredefinedRuntimeFunction(unsigned ID) const { 163 return strchr(getRecord(ID).Attributes, 'i') != nullptr; 164 } 165 166 /// Determines whether this builtin is a C++ standard library function 167 /// that lives in (possibly-versioned) namespace std, possibly a template 168 /// specialization, where the signature is determined by the standard library 169 /// declaration. 170 bool isInStdNamespace(unsigned ID) const { 171 return strchr(getRecord(ID).Attributes, 'z') != nullptr; 172 } 173 174 /// Determines whether this builtin can have its address taken with no 175 /// special action required. 176 bool isDirectlyAddressable(unsigned ID) const { 177 // Most standard library functions can have their addresses taken. C++ 178 // standard library functions formally cannot in C++20 onwards, and when 179 // we allow it, we need to ensure we instantiate a definition. 180 return isPredefinedLibFunction(ID) && !isInStdNamespace(ID); 181 } 182 183 /// Determines whether this builtin has custom typechecking. 184 bool hasCustomTypechecking(unsigned ID) const { 185 return strchr(getRecord(ID).Attributes, 't') != nullptr; 186 } 187 188 /// Determines whether a declaration of this builtin should be recognized 189 /// even if the type doesn't match the specified signature. 190 bool allowTypeMismatch(unsigned ID) const { 191 return strchr(getRecord(ID).Attributes, 'T') != nullptr || 192 hasCustomTypechecking(ID); 193 } 194 195 /// Determines whether this builtin has a result or any arguments which 196 /// are pointer types. 197 bool hasPtrArgsOrResult(unsigned ID) const { 198 return strchr(getRecord(ID).Type, '*') != nullptr; 199 } 200 201 /// Return true if this builtin has a result or any arguments which are 202 /// reference types. 203 bool hasReferenceArgsOrResult(unsigned ID) const { 204 return strchr(getRecord(ID).Type, '&') != nullptr || 205 strchr(getRecord(ID).Type, 'A') != nullptr; 206 } 207 208 /// If this is a library function that comes from a specific 209 /// header, retrieve that header name. 210 const char *getHeaderName(unsigned ID) const { 211 return getRecord(ID).HeaderName; 212 } 213 214 /// Determine whether this builtin is like printf in its 215 /// formatting rules and, if so, set the index to the format string 216 /// argument and whether this function as a va_list argument. 217 bool isPrintfLike(unsigned ID, unsigned &FormatIdx, bool &HasVAListArg); 218 219 /// Determine whether this builtin is like scanf in its 220 /// formatting rules and, if so, set the index to the format string 221 /// argument and whether this function as a va_list argument. 222 bool isScanfLike(unsigned ID, unsigned &FormatIdx, bool &HasVAListArg); 223 224 /// Determine whether this builtin has callback behavior (see 225 /// llvm::AbstractCallSites for details). If so, add the index to the 226 /// callback callee argument and the callback payload arguments. 227 bool performsCallback(unsigned ID, 228 llvm::SmallVectorImpl<int> &Encoding) const; 229 230 /// Return true if this function has no side effects and doesn't 231 /// read memory, except for possibly errno. 232 /// 233 /// Such functions can be const when the MathErrno lang option is disabled. 234 bool isConstWithoutErrno(unsigned ID) const { 235 return strchr(getRecord(ID).Attributes, 'e') != nullptr; 236 } 237 238 const char *getRequiredFeatures(unsigned ID) const { 239 return getRecord(ID).Features; 240 } 241 242 unsigned getRequiredVectorWidth(unsigned ID) const; 243 244 /// Return true if builtin ID belongs to AuxTarget. 245 bool isAuxBuiltinID(unsigned ID) const { 246 return ID >= (Builtin::FirstTSBuiltin + TSRecords.size()); 247 } 248 249 /// Return real builtin ID (i.e. ID it would have during compilation 250 /// for AuxTarget). 251 unsigned getAuxBuiltinID(unsigned ID) const { return ID - TSRecords.size(); } 252 253 /// Returns true if this is a libc/libm function without the '__builtin_' 254 /// prefix. 255 static bool isBuiltinFunc(llvm::StringRef Name); 256 257 /// Returns true if this is a builtin that can be redeclared. Returns true 258 /// for non-builtins. 259 bool canBeRedeclared(unsigned ID) const; 260 261 private: 262 const Info &getRecord(unsigned ID) const; 263 264 /// Helper function for isPrintfLike and isScanfLike. 265 bool isLike(unsigned ID, unsigned &FormatIdx, bool &HasVAListArg, 266 const char *Fmt) const; 267 }; 268 269 /// Returns true if the required target features of a builtin function are 270 /// enabled. 271 /// \p TargetFeatureMap maps a target feature to true if it is enabled and 272 /// false if it is disabled. 273 bool evaluateRequiredTargetFeatures( 274 llvm::StringRef RequiredFatures, 275 const llvm::StringMap<bool> &TargetFetureMap); 276 277 } // namespace Builtin 278 279 /// Kinds of BuiltinTemplateDecl. 280 enum BuiltinTemplateKind : int { 281 /// This names the __make_integer_seq BuiltinTemplateDecl. 282 BTK__make_integer_seq, 283 284 /// This names the __type_pack_element BuiltinTemplateDecl. 285 BTK__type_pack_element 286 }; 287 288 } // end namespace clang 289 #endif 290