Function.h revision ad2afc2a421a0e41603d5eee412d4d8c77e9bc1c
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/Attributes.h" 25 26namespace llvm { 27 28class FunctionType; 29class LLVMContext; 30 31// Traits for intrusive list of basic blocks... 32template<> struct ilist_traits<BasicBlock> 33 : public SymbolTableListTraits<BasicBlock, Function> { 34 35 // createSentinel is used to get hold of the node that marks the end of the 36 // list... (same trick used here as in ilist_traits<Instruction>) 37 BasicBlock *createSentinel() const { 38 return static_cast<BasicBlock*>(&Sentinel); 39 } 40 static void destroySentinel(BasicBlock*) {} 41 42 BasicBlock *provideInitialHead() const { return createSentinel(); } 43 BasicBlock *ensureHead(BasicBlock*) const { return createSentinel(); } 44 static void noteHead(BasicBlock*, BasicBlock*) {} 45 46 static ValueSymbolTable *getSymTab(Function *ItemParent); 47private: 48 mutable ilist_node<BasicBlock> Sentinel; 49}; 50 51template<> struct ilist_traits<Argument> 52 : public SymbolTableListTraits<Argument, Function> { 53 54 Argument *createSentinel() const { 55 return static_cast<Argument*>(&Sentinel); 56 } 57 static void destroySentinel(Argument*) {} 58 59 Argument *provideInitialHead() const { return createSentinel(); } 60 Argument *ensureHead(Argument*) const { return createSentinel(); } 61 static void noteHead(Argument*, Argument*) {} 62 63 static ValueSymbolTable *getSymTab(Function *ItemParent); 64private: 65 mutable ilist_node<Argument> Sentinel; 66}; 67 68class Function : public GlobalValue, 69 public ilist_node<Function> { 70public: 71 typedef iplist<Argument> ArgumentListType; 72 typedef iplist<BasicBlock> BasicBlockListType; 73 74 // BasicBlock iterators... 75 typedef BasicBlockListType::iterator iterator; 76 typedef BasicBlockListType::const_iterator const_iterator; 77 78 typedef ArgumentListType::iterator arg_iterator; 79 typedef ArgumentListType::const_iterator const_arg_iterator; 80 81private: 82 // Important things that make up a function! 83 BasicBlockListType BasicBlocks; ///< The basic blocks 84 mutable ArgumentListType ArgumentList; ///< The formal arguments 85 ValueSymbolTable *SymTab; ///< Symbol table of args/instructions 86 AttrListPtr AttributeList; ///< Parameter attributes 87 88 // The Calling Convention is stored in Value::SubclassData. 89 /*unsigned CallingConvention;*/ 90 91 friend class SymbolTableListTraits<Function, Module>; 92 93 void setParent(Module *parent); 94 95 /// hasLazyArguments/CheckLazyArguments - The argument list of a function is 96 /// built on demand, so that the list isn't allocated until the first client 97 /// needs it. The hasLazyArguments predicate returns true if the arg list 98 /// hasn't been set up yet. 99 bool hasLazyArguments() const { 100 return SubclassData & 1; 101 } 102 void CheckLazyArguments() const { 103 if (hasLazyArguments()) 104 BuildLazyArguments(); 105 } 106 void BuildLazyArguments() const; 107 108 Function(const Function&); // DO NOT IMPLEMENT 109 void operator=(const Function&); // DO NOT IMPLEMENT 110 111 /// Function ctor - If the (optional) Module argument is specified, the 112 /// function is automatically inserted into the end of the function list for 113 /// the module. 114 /// 115 Function(const FunctionType *Ty, LinkageTypes Linkage, 116 const Twine &N = "", Module *M = 0); 117 118public: 119 static Function *Create(const FunctionType *Ty, LinkageTypes Linkage, 120 const Twine &N = "", Module *M = 0) { 121 return new(0) Function(Ty, Linkage, N, M); 122 } 123 124 ~Function(); 125 126 const Type *getReturnType() const; // Return the type of the ret val 127 const FunctionType *getFunctionType() const; // Return the FunctionType for me 128 129 /// getContext - Return a pointer to the LLVMContext associated with this 130 /// function, or NULL if this function is not bound to a context yet. 131 LLVMContext &getContext() const; 132 133 /// isVarArg - Return true if this function takes a variable number of 134 /// arguments. 135 bool isVarArg() const; 136 137 /// isDeclaration - Is the body of this function unknown? (The basic block 138 /// list is empty if so.) This is true for function declarations, but not 139 /// true for function definitions. 140 /// 141 virtual bool isDeclaration() const { return BasicBlocks.empty(); } 142 143 /// getIntrinsicID - This method returns the ID number of the specified 144 /// function, or Intrinsic::not_intrinsic if the function is not an 145 /// instrinsic, or if the pointer is null. This value is always defined to be 146 /// zero to allow easy checking for whether a function is intrinsic or not. 147 /// The particular intrinsic functions which correspond to this value are 148 /// defined in llvm/Intrinsics.h. 149 /// 150 unsigned getIntrinsicID() const; 151 bool isIntrinsic() const { return getIntrinsicID() != 0; } 152 153 /// getCallingConv()/setCallingConv(uint) - These method get and set the 154 /// calling convention of this function. The enum values for the known 155 /// calling conventions are defined in CallingConv.h. 156 unsigned getCallingConv() const { return SubclassData >> 1; } 157 void setCallingConv(unsigned CC) { 158 SubclassData = (SubclassData & 1) | (CC << 1); 159 } 160 161 /// getAttributes - Return the attribute list for this Function. 162 /// 163 const AttrListPtr &getAttributes() const { return AttributeList; } 164 165 /// setAttributes - Set the attribute list for this Function. 166 /// 167 void setAttributes(const AttrListPtr &attrs) { AttributeList = attrs; } 168 169 /// hasFnAttr - Return true if this function has the given attribute. 170 bool hasFnAttr(Attributes N) const { 171 // Function Attributes are stored at ~0 index 172 return AttributeList.paramHasAttr(~0U, N); 173 } 174 175 /// addFnAttr - Add function attributes to this function. 176 /// 177 void addFnAttr(Attributes N) { 178 // Function Attributes are stored at ~0 index 179 addAttribute(~0U, N); 180 } 181 182 /// removeFnAttr - Remove function attributes from this function. 183 /// 184 void removeFnAttr(Attributes N) { 185 // Function Attributes are stored at ~0 index 186 removeAttribute(~0U, N); 187 } 188 189 /// hasGC/getGC/setGC/clearGC - The name of the garbage collection algorithm 190 /// to use during code generation. 191 bool hasGC() const; 192 const char *getGC() const; 193 void setGC(const char *Str); 194 void clearGC(); 195 196 /// @brief Determine whether the function has the given attribute. 197 bool paramHasAttr(unsigned i, Attributes attr) const { 198 return AttributeList.paramHasAttr(i, attr); 199 } 200 201 /// addAttribute - adds the attribute to the list of attributes. 202 void addAttribute(unsigned i, Attributes attr); 203 204 /// removeAttribute - removes the attribute from the list of attributes. 205 void removeAttribute(unsigned i, Attributes attr); 206 207 /// @brief Extract the alignment for a call or parameter (0=unknown). 208 unsigned getParamAlignment(unsigned i) const { 209 return AttributeList.getParamAlignment(i); 210 } 211 212 /// @brief Determine if the function does not access memory. 213 bool doesNotAccessMemory() const { 214 return hasFnAttr(Attribute::ReadNone); 215 } 216 void setDoesNotAccessMemory(bool DoesNotAccessMemory = true) { 217 if (DoesNotAccessMemory) addFnAttr(Attribute::ReadNone); 218 else removeFnAttr(Attribute::ReadNone); 219 } 220 221 /// @brief Determine if the function does not access or only reads memory. 222 bool onlyReadsMemory() const { 223 return doesNotAccessMemory() || hasFnAttr(Attribute::ReadOnly); 224 } 225 void setOnlyReadsMemory(bool OnlyReadsMemory = true) { 226 if (OnlyReadsMemory) addFnAttr(Attribute::ReadOnly); 227 else removeFnAttr(Attribute::ReadOnly | Attribute::ReadNone); 228 } 229 230 /// @brief Determine if the function cannot return. 231 bool doesNotReturn() const { 232 return hasFnAttr(Attribute::NoReturn); 233 } 234 void setDoesNotReturn(bool DoesNotReturn = true) { 235 if (DoesNotReturn) addFnAttr(Attribute::NoReturn); 236 else removeFnAttr(Attribute::NoReturn); 237 } 238 239 /// @brief Determine if the function cannot unwind. 240 bool doesNotThrow() const { 241 return hasFnAttr(Attribute::NoUnwind); 242 } 243 void setDoesNotThrow(bool DoesNotThrow = true) { 244 if (DoesNotThrow) addFnAttr(Attribute::NoUnwind); 245 else removeFnAttr(Attribute::NoUnwind); 246 } 247 248 /// @brief Determine if the function returns a structure through first 249 /// pointer argument. 250 bool hasStructRetAttr() const { 251 return paramHasAttr(1, Attribute::StructRet); 252 } 253 254 /// @brief Determine if the parameter does not alias other parameters. 255 /// @param n The parameter to check. 1 is the first parameter, 0 is the return 256 bool doesNotAlias(unsigned n) const { 257 return paramHasAttr(n, Attribute::NoAlias); 258 } 259 void setDoesNotAlias(unsigned n, bool DoesNotAlias = true) { 260 if (DoesNotAlias) addAttribute(n, Attribute::NoAlias); 261 else removeAttribute(n, Attribute::NoAlias); 262 } 263 264 /// @brief Determine if the parameter can be captured. 265 /// @param n The parameter to check. 1 is the first parameter, 0 is the return 266 bool doesNotCapture(unsigned n) const { 267 return paramHasAttr(n, Attribute::NoCapture); 268 } 269 void setDoesNotCapture(unsigned n, bool DoesNotCapture = true) { 270 if (DoesNotCapture) addAttribute(n, Attribute::NoCapture); 271 else removeAttribute(n, Attribute::NoCapture); 272 } 273 274 /// copyAttributesFrom - copy all additional attributes (those not needed to 275 /// create a Function) from the Function Src to this one. 276 void copyAttributesFrom(const GlobalValue *Src); 277 278 /// deleteBody - This method deletes the body of the function, and converts 279 /// the linkage to external. 280 /// 281 void deleteBody() { 282 dropAllReferences(); 283 setLinkage(ExternalLinkage); 284 } 285 286 /// removeFromParent - This method unlinks 'this' from the containing module, 287 /// but does not delete it. 288 /// 289 virtual void removeFromParent(); 290 291 /// eraseFromParent - This method unlinks 'this' from the containing module 292 /// and deletes it. 293 /// 294 virtual void eraseFromParent(); 295 296 297 /// Get the underlying elements of the Function... the basic block list is 298 /// empty for external functions. 299 /// 300 const ArgumentListType &getArgumentList() const { 301 CheckLazyArguments(); 302 return ArgumentList; 303 } 304 ArgumentListType &getArgumentList() { 305 CheckLazyArguments(); 306 return ArgumentList; 307 } 308 static iplist<Argument> Function::*getSublistAccess(Argument*) { 309 return &Function::ArgumentList; 310 } 311 312 const BasicBlockListType &getBasicBlockList() const { return BasicBlocks; } 313 BasicBlockListType &getBasicBlockList() { return BasicBlocks; } 314 static iplist<BasicBlock> Function::*getSublistAccess(BasicBlock*) { 315 return &Function::BasicBlocks; 316 } 317 318 const BasicBlock &getEntryBlock() const { return front(); } 319 BasicBlock &getEntryBlock() { return front(); } 320 321 //===--------------------------------------------------------------------===// 322 // Symbol Table Accessing functions... 323 324 /// getSymbolTable() - Return the symbol table... 325 /// 326 inline ValueSymbolTable &getValueSymbolTable() { return *SymTab; } 327 inline const ValueSymbolTable &getValueSymbolTable() const { return *SymTab; } 328 329 330 //===--------------------------------------------------------------------===// 331 // BasicBlock iterator forwarding functions 332 // 333 iterator begin() { return BasicBlocks.begin(); } 334 const_iterator begin() const { return BasicBlocks.begin(); } 335 iterator end () { return BasicBlocks.end(); } 336 const_iterator end () const { return BasicBlocks.end(); } 337 338 size_t size() const { return BasicBlocks.size(); } 339 bool empty() const { return BasicBlocks.empty(); } 340 const BasicBlock &front() const { return BasicBlocks.front(); } 341 BasicBlock &front() { return BasicBlocks.front(); } 342 const BasicBlock &back() const { return BasicBlocks.back(); } 343 BasicBlock &back() { return BasicBlocks.back(); } 344 345 //===--------------------------------------------------------------------===// 346 // Argument iterator forwarding functions 347 // 348 arg_iterator arg_begin() { 349 CheckLazyArguments(); 350 return ArgumentList.begin(); 351 } 352 const_arg_iterator arg_begin() const { 353 CheckLazyArguments(); 354 return ArgumentList.begin(); 355 } 356 arg_iterator arg_end() { 357 CheckLazyArguments(); 358 return ArgumentList.end(); 359 } 360 const_arg_iterator arg_end() const { 361 CheckLazyArguments(); 362 return ArgumentList.end(); 363 } 364 365 size_t arg_size() const; 366 bool arg_empty() const; 367 368 /// viewCFG - This function is meant for use from the debugger. You can just 369 /// say 'call F->viewCFG()' and a ghostview window should pop up from the 370 /// program, displaying the CFG of the current function with the code for each 371 /// basic block inside. This depends on there being a 'dot' and 'gv' program 372 /// in your path. 373 /// 374 void viewCFG() const; 375 376 /// viewCFGOnly - This function is meant for use from the debugger. It works 377 /// just like viewCFG, but it does not include the contents of basic blocks 378 /// into the nodes, just the label. If you are only interested in the CFG 379 /// this can make the graph smaller. 380 /// 381 void viewCFGOnly() const; 382 383 /// Methods for support type inquiry through isa, cast, and dyn_cast: 384 static inline bool classof(const Function *) { return true; } 385 static inline bool classof(const Value *V) { 386 return V->getValueID() == Value::FunctionVal; 387 } 388 389 /// dropAllReferences() - This method causes all the subinstructions to "let 390 /// go" of all references that they are maintaining. This allows one to 391 /// 'delete' a whole module at a time, even though there may be circular 392 /// references... first all references are dropped, and all use counts go to 393 /// zero. Then everything is deleted for real. Note that no operations are 394 /// valid on an object that has "dropped all references", except operator 395 /// delete. 396 /// 397 /// Since no other object in the module can have references into the body of a 398 /// function, dropping all references deletes the entire body of the function, 399 /// including any contained basic blocks. 400 /// 401 void dropAllReferences(); 402 403 /// hasAddressTaken - returns true if there are any uses of this function 404 /// other than direct calls or invokes to it. 405 bool hasAddressTaken() const; 406}; 407 408inline ValueSymbolTable * 409ilist_traits<BasicBlock>::getSymTab(Function *F) { 410 return F ? &F->getValueSymbolTable() : 0; 411} 412 413inline ValueSymbolTable * 414ilist_traits<Argument>::getSymTab(Function *F) { 415 return F ? &F->getValueSymbolTable() : 0; 416} 417 418} // End llvm namespace 419 420#endif 421