Function.h revision 71c8c175fb2a477b90efe745aaf48ed9265300a9
1//===-- llvm/Function.h - Class to represent a single function --*- C++ -*-===// 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// This file contains the declaration of the Function class, which represents a 11// single function/procedure in LLVM. 12// 13// A function basically consists of a list of basic blocks, a list of arguments, 14// and a symbol table. 15// 16//===----------------------------------------------------------------------===// 17 18#ifndef LLVM_FUNCTION_H 19#define LLVM_FUNCTION_H 20 21#include "llvm/GlobalValue.h" 22#include "llvm/BasicBlock.h" 23#include "llvm/Argument.h" 24#include "llvm/Support/Annotation.h" 25#include "llvm/ParameterAttributes.h" 26 27namespace llvm { 28 29class FunctionType; 30 31// Traits for intrusive list of instructions... 32template<> struct ilist_traits<BasicBlock> 33 : public SymbolTableListTraits<BasicBlock, Function> { 34 35 // createSentinel is used to create a node that marks the end of the list... 36 static BasicBlock *createSentinel(); 37 static void destroySentinel(BasicBlock *BB) { delete BB; } 38 static iplist<BasicBlock> &getList(Function *F); 39 static ValueSymbolTable *getSymTab(Function *ItemParent); 40 static int getListOffset(); 41}; 42 43template<> struct ilist_traits<Argument> 44 : public SymbolTableListTraits<Argument, Function> { 45 46 // createSentinel is used to create a node that marks the end of the list... 47 static Argument *createSentinel(); 48 static void destroySentinel(Argument *A) { delete A; } 49 static iplist<Argument> &getList(Function *F); 50 static ValueSymbolTable *getSymTab(Function *ItemParent); 51 static int getListOffset(); 52}; 53 54class Function : public GlobalValue, public Annotable, 55 public ilist_node<Function> { 56public: 57 typedef iplist<Argument> ArgumentListType; 58 typedef iplist<BasicBlock> BasicBlockListType; 59 60 // BasicBlock iterators... 61 typedef BasicBlockListType::iterator iterator; 62 typedef BasicBlockListType::const_iterator const_iterator; 63 64 typedef ArgumentListType::iterator arg_iterator; 65 typedef ArgumentListType::const_iterator const_arg_iterator; 66 67private: 68 // Important things that make up a function! 69 BasicBlockListType BasicBlocks; ///< The basic blocks 70 mutable ArgumentListType ArgumentList; ///< The formal arguments 71 ValueSymbolTable *SymTab; ///< Symbol table of args/instructions 72 PAListPtr ParamAttrs; ///< Parameter attributes 73 74 // The Calling Convention is stored in Value::SubclassData. 75 /*unsigned CallingConvention;*/ 76 77 friend class SymbolTableListTraits<Function, Module>; 78 79 void setParent(Module *parent); 80 81 /// hasLazyArguments/CheckLazyArguments - The argument list of a function is 82 /// built on demand, so that the list isn't allocated until the first client 83 /// needs it. The hasLazyArguments predicate returns true if the arg list 84 /// hasn't been set up yet. 85 bool hasLazyArguments() const { 86 return SubclassData & 1; 87 } 88 void CheckLazyArguments() const { 89 if (hasLazyArguments()) 90 BuildLazyArguments(); 91 } 92 void BuildLazyArguments() const; 93 94 Function(const Function&); // DO NOT IMPLEMENT 95 void operator=(const Function&); // DO NOT IMPLEMENT 96 97 /// Function ctor - If the (optional) Module argument is specified, the 98 /// function is automatically inserted into the end of the function list for 99 /// the module. 100 /// 101 Function(const FunctionType *Ty, LinkageTypes Linkage, 102 const std::string &N = "", Module *M = 0); 103 104public: 105 static Function *Create(const FunctionType *Ty, LinkageTypes Linkage, 106 const std::string &N = "", Module *M = 0) { 107 return new(0) Function(Ty, Linkage, N, M); 108 } 109 110 ~Function(); 111 112 const Type *getReturnType() const; // Return the type of the ret val 113 const FunctionType *getFunctionType() const; // Return the FunctionType for me 114 115 /// isVarArg - Return true if this function takes a variable number of 116 /// arguments. 117 bool isVarArg() const; 118 119 /// isDeclaration - Is the body of this function unknown? (The basic block 120 /// list is empty if so.) This is true for function declarations, but not 121 /// true for function definitions. 122 /// 123 virtual bool isDeclaration() const { return BasicBlocks.empty(); } 124 125 /// getIntrinsicID - This method returns the ID number of the specified 126 /// function, or Intrinsic::not_intrinsic if the function is not an 127 /// instrinsic, or if the pointer is null. This value is always defined to be 128 /// zero to allow easy checking for whether a function is intrinsic or not. 129 /// The particular intrinsic functions which correspond to this value are 130 /// defined in llvm/Intrinsics.h. 131 /// 132 unsigned getIntrinsicID(bool noAssert = false) const; 133 bool isIntrinsic() const { return getIntrinsicID() != 0; } 134 135 /// getCallingConv()/setCallingConv(uint) - These method get and set the 136 /// calling convention of this function. The enum values for the known 137 /// calling conventions are defined in CallingConv.h. 138 unsigned getCallingConv() const { return SubclassData >> 1; } 139 void setCallingConv(unsigned CC) { 140 SubclassData = (SubclassData & 1) | (CC << 1); 141 } 142 143 /// getParamAttrs - Return the parameter attributes for this Function. 144 /// 145 const PAListPtr &getParamAttrs() const { return ParamAttrs; } 146 147 /// setParamAttrs - Set the parameter attributes for this Function. 148 /// 149 void setParamAttrs(const PAListPtr &attrs) { ParamAttrs = attrs; } 150 151 /// hasGC/getGC/setGC/clearGC - The name of the garbage collection algorithm 152 /// to use during code generation. 153 bool hasGC() const; 154 const char *getGC() const; 155 void setGC(const char *Str); 156 void clearGC(); 157 158 /// @brief Determine whether the function has the given attribute. 159 bool paramHasAttr(unsigned i, ParameterAttributes attr) const { 160 return ParamAttrs.paramHasAttr(i, attr); 161 } 162 163 /// addParamAttr - adds the attribute to the list of attributes. 164 void addParamAttr(unsigned i, ParameterAttributes attr); 165 166 /// removeParamAttr - removes the attribute from the list of attributes. 167 void removeParamAttr(unsigned i, ParameterAttributes attr); 168 169 /// @brief Extract the alignment for a call or parameter (0=unknown). 170 unsigned getParamAlignment(unsigned i) const { 171 return ParamAttrs.getParamAlignment(i); 172 } 173 174 /// @brief Determine if the function does not access memory. 175 bool doesNotAccessMemory() const { 176 return paramHasAttr(0, ParamAttr::ReadNone); 177 } 178 void setDoesNotAccessMemory(bool DoesNotAccessMemory = true) { 179 if (DoesNotAccessMemory) addParamAttr(0, ParamAttr::ReadNone); 180 else removeParamAttr(0, ParamAttr::ReadNone); 181 } 182 183 /// @brief Determine if the function does not access or only reads memory. 184 bool onlyReadsMemory() const { 185 return doesNotAccessMemory() || paramHasAttr(0, ParamAttr::ReadOnly); 186 } 187 void setOnlyReadsMemory(bool OnlyReadsMemory = true) { 188 if (OnlyReadsMemory) addParamAttr(0, ParamAttr::ReadOnly); 189 else removeParamAttr(0, ParamAttr::ReadOnly | ParamAttr::ReadNone); 190 } 191 192 /// @brief Determine if the function cannot return. 193 bool doesNotReturn() const { 194 return paramHasAttr(0, ParamAttr::NoReturn); 195 } 196 void setDoesNotReturn(bool DoesNotReturn = true) { 197 if (DoesNotReturn) addParamAttr(0, ParamAttr::NoReturn); 198 else removeParamAttr(0, ParamAttr::NoReturn); 199 } 200 201 /// @brief Determine if the function cannot unwind. 202 bool doesNotThrow() const { 203 return paramHasAttr(0, ParamAttr::NoUnwind); 204 } 205 void setDoesNotThrow(bool DoesNotThrow = true) { 206 if (DoesNotThrow) addParamAttr(0, ParamAttr::NoUnwind); 207 else removeParamAttr(0, ParamAttr::NoUnwind); 208 } 209 210 /// @brief Determine if the function returns a structure through first 211 /// pointer argument. 212 bool hasStructRetAttr() const { 213 return paramHasAttr(1, ParamAttr::StructRet); 214 } 215 216 /// copyAttributesFrom - copy all additional attributes (those not needed to 217 /// create a Function) from the Function Src to this one. 218 void copyAttributesFrom(const GlobalValue *Src); 219 220 /// deleteBody - This method deletes the body of the function, and converts 221 /// the linkage to external. 222 /// 223 void deleteBody() { 224 dropAllReferences(); 225 setLinkage(ExternalLinkage); 226 } 227 228 /// removeFromParent - This method unlinks 'this' from the containing module, 229 /// but does not delete it. 230 /// 231 virtual void removeFromParent(); 232 233 /// eraseFromParent - This method unlinks 'this' from the containing module 234 /// and deletes it. 235 /// 236 virtual void eraseFromParent(); 237 238 239 /// Get the underlying elements of the Function... the basic block list is 240 /// empty for external functions. 241 /// 242 const ArgumentListType &getArgumentList() const { 243 CheckLazyArguments(); 244 return ArgumentList; 245 } 246 ArgumentListType &getArgumentList() { 247 CheckLazyArguments(); 248 return ArgumentList; 249 } 250 251 const BasicBlockListType &getBasicBlockList() const { return BasicBlocks; } 252 BasicBlockListType &getBasicBlockList() { return BasicBlocks; } 253 254 const BasicBlock &getEntryBlock() const { return front(); } 255 BasicBlock &getEntryBlock() { return front(); } 256 257 //===--------------------------------------------------------------------===// 258 // Symbol Table Accessing functions... 259 260 /// getSymbolTable() - Return the symbol table... 261 /// 262 inline ValueSymbolTable &getValueSymbolTable() { return *SymTab; } 263 inline const ValueSymbolTable &getValueSymbolTable() const { return *SymTab; } 264 265 266 //===--------------------------------------------------------------------===// 267 // BasicBlock iterator forwarding functions 268 // 269 iterator begin() { return BasicBlocks.begin(); } 270 const_iterator begin() const { return BasicBlocks.begin(); } 271 iterator end () { return BasicBlocks.end(); } 272 const_iterator end () const { return BasicBlocks.end(); } 273 274 size_t size() const { return BasicBlocks.size(); } 275 bool empty() const { return BasicBlocks.empty(); } 276 const BasicBlock &front() const { return BasicBlocks.front(); } 277 BasicBlock &front() { return BasicBlocks.front(); } 278 const BasicBlock &back() const { return BasicBlocks.back(); } 279 BasicBlock &back() { return BasicBlocks.back(); } 280 281 //===--------------------------------------------------------------------===// 282 // Argument iterator forwarding functions 283 // 284 arg_iterator arg_begin() { 285 CheckLazyArguments(); 286 return ArgumentList.begin(); 287 } 288 const_arg_iterator arg_begin() const { 289 CheckLazyArguments(); 290 return ArgumentList.begin(); 291 } 292 arg_iterator arg_end() { 293 CheckLazyArguments(); 294 return ArgumentList.end(); 295 } 296 const_arg_iterator arg_end() const { 297 CheckLazyArguments(); 298 return ArgumentList.end(); 299 } 300 301 size_t arg_size() const; 302 bool arg_empty() const; 303 304 /// viewCFG - This function is meant for use from the debugger. You can just 305 /// say 'call F->viewCFG()' and a ghostview window should pop up from the 306 /// program, displaying the CFG of the current function with the code for each 307 /// basic block inside. This depends on there being a 'dot' and 'gv' program 308 /// in your path. 309 /// 310 void viewCFG() const; 311 312 /// viewCFGOnly - This function is meant for use from the debugger. It works 313 /// just like viewCFG, but it does not include the contents of basic blocks 314 /// into the nodes, just the label. If you are only interested in the CFG 315 /// this can make the graph smaller. 316 /// 317 void viewCFGOnly() const; 318 319 /// Methods for support type inquiry through isa, cast, and dyn_cast: 320 static inline bool classof(const Function *) { return true; } 321 static inline bool classof(const Value *V) { 322 return V->getValueID() == Value::FunctionVal; 323 } 324 325 /// dropAllReferences() - This method causes all the subinstructions to "let 326 /// go" of all references that they are maintaining. This allows one to 327 /// 'delete' a whole module at a time, even though there may be circular 328 /// references... first all references are dropped, and all use counts go to 329 /// zero. Then everything is deleted for real. Note that no operations are 330 /// valid on an object that has "dropped all references", except operator 331 /// delete. 332 /// 333 /// Since no other object in the module can have references into the body of a 334 /// function, dropping all references deletes the entire body of the function, 335 /// including any contained basic blocks. 336 /// 337 void dropAllReferences(); 338 339 static unsigned getBasicBlockListOffset() { 340 Function *Obj = 0; 341 return unsigned(reinterpret_cast<uintptr_t>(&Obj->BasicBlocks)); 342 } 343 static unsigned getArgumentListOffset() { 344 Function *Obj = 0; 345 return unsigned(reinterpret_cast<uintptr_t>(&Obj->ArgumentList)); 346 } 347}; 348 349inline ValueSymbolTable * 350ilist_traits<BasicBlock>::getSymTab(Function *F) { 351 return F ? &F->getValueSymbolTable() : 0; 352} 353 354inline ValueSymbolTable * 355ilist_traits<Argument>::getSymTab(Function *F) { 356 return F ? &F->getValueSymbolTable() : 0; 357} 358 359inline int 360ilist_traits<BasicBlock>::getListOffset() { 361 return Function::getBasicBlockListOffset(); 362} 363 364inline int 365ilist_traits<Argument>::getListOffset() { 366 return Function::getArgumentListOffset(); 367} 368 369 370} // End llvm namespace 371 372#endif 373