1 //===-- llvm/Function.h - Class to represent a single function --*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains the declaration of the Function class, which represents a
11 // single function/procedure in LLVM.
13 // A function basically consists of a list of basic blocks, a list of arguments,
14 // and a symbol table.
16 //===----------------------------------------------------------------------===//
18 #ifndef LLVM_FUNCTION_H
19 #define LLVM_FUNCTION_H
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"
31 // Traits for intrusive list of instructions...
32 template<> struct ilist_traits<BasicBlock>
33 : public SymbolTableListTraits<BasicBlock, Function> {
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();
43 template<> struct ilist_traits<Argument>
44 : public SymbolTableListTraits<Argument, Function> {
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();
54 class Function : public GlobalValue, public Annotable {
56 typedef iplist<Argument> ArgumentListType;
57 typedef iplist<BasicBlock> BasicBlockListType;
59 // BasicBlock iterators...
60 typedef BasicBlockListType::iterator iterator;
61 typedef BasicBlockListType::const_iterator const_iterator;
63 typedef ArgumentListType::iterator arg_iterator;
64 typedef ArgumentListType::const_iterator const_arg_iterator;
67 // Important things that make up a function!
68 BasicBlockListType BasicBlocks; ///< The basic blocks
69 mutable ArgumentListType ArgumentList; ///< The formal arguments
70 ValueSymbolTable *SymTab; ///< Symbol table of args/instructions
71 PAListPtr ParamAttrs; ///< Parameter attributes
73 // The Calling Convention is stored in Value::SubclassData.
74 /*unsigned CallingConvention;*/
76 friend class SymbolTableListTraits<Function, Module>;
78 void setParent(Module *parent);
79 Function *Prev, *Next;
80 void setNext(Function *N) { Next = N; }
81 void setPrev(Function *N) { Prev = N; }
83 // getNext/Prev - Return the next or previous function in the list. These
84 // methods should never be used directly, and are only used to implement the
85 // function list as part of the module.
87 Function *getNext() { return Next; }
88 const Function *getNext() const { return Next; }
89 Function *getPrev() { return Prev; }
90 const Function *getPrev() const { return Prev; }
92 /// hasLazyArguments/CheckLazyArguments - The argument list of a function is
93 /// built on demand, so that the list isn't allocated until the first client
94 /// needs it. The hasLazyArguments predicate returns true if the arg list
95 /// hasn't been set up yet.
96 bool hasLazyArguments() const {
97 return SubclassData & 1;
99 void CheckLazyArguments() const {
100 if (hasLazyArguments())
101 BuildLazyArguments();
103 void BuildLazyArguments() const;
105 Function(const Function&); // DO NOT IMPLEMENT
106 void operator=(const Function&); // DO NOT IMPLEMENT
108 /// Function ctor - If the (optional) Module argument is specified, the
109 /// function is automatically inserted into the end of the function list for
112 Function(const FunctionType *Ty, LinkageTypes Linkage,
113 const std::string &N = "", Module *M = 0);
116 static Function *Create(const FunctionType *Ty, LinkageTypes Linkage,
117 const std::string &N = "", Module *M = 0) {
118 return new(0) Function(Ty, Linkage, N, M);
123 const Type *getReturnType() const; // Return the type of the ret val
124 const FunctionType *getFunctionType() const; // Return the FunctionType for me
126 /// isVarArg - Return true if this function takes a variable number of
128 bool isVarArg() const;
130 /// isDeclaration - Is the body of this function unknown? (The basic block
131 /// list is empty if so.) This is true for function declarations, but not
132 /// true for function definitions.
134 virtual bool isDeclaration() const { return BasicBlocks.empty(); }
136 /// getIntrinsicID - This method returns the ID number of the specified
137 /// function, or Intrinsic::not_intrinsic if the function is not an
138 /// instrinsic, or if the pointer is null. This value is always defined to be
139 /// zero to allow easy checking for whether a function is intrinsic or not.
140 /// The particular intrinsic functions which correspond to this value are
141 /// defined in llvm/Intrinsics.h.
143 unsigned getIntrinsicID(bool noAssert = false) const;
144 bool isIntrinsic() const { return getIntrinsicID() != 0; }
146 /// getCallingConv()/setCallingConv(uint) - These method get and set the
147 /// calling convention of this function. The enum values for the known
148 /// calling conventions are defined in CallingConv.h.
149 unsigned getCallingConv() const { return SubclassData >> 1; }
150 void setCallingConv(unsigned CC) {
151 SubclassData = (SubclassData & 1) | (CC << 1);
154 /// getParamAttrs - Return the parameter attributes for this Function.
156 const PAListPtr &getParamAttrs() const { return ParamAttrs; }
158 /// setParamAttrs - Set the parameter attributes for this Function.
160 void setParamAttrs(const PAListPtr &attrs) { ParamAttrs = attrs; }
162 /// hasCollector/getCollector/setCollector/clearCollector - The name of the
163 /// garbage collection algorithm to use during code generation.
164 bool hasCollector() const;
165 const char *getCollector() const;
166 void setCollector(const char *Str);
167 void clearCollector();
169 /// @brief Determine whether the function has the given attribute.
170 bool paramHasAttr(unsigned i, ParameterAttributes attr) const {
171 return ParamAttrs.paramHasAttr(i, attr);
174 /// addParamAttr - adds the attribute to the list of attributes.
175 void addParamAttr(unsigned i, ParameterAttributes attr);
177 /// @brief Extract the alignment for a call or parameter (0=unknown).
178 unsigned getParamAlignment(unsigned i) const {
179 return ParamAttrs.getParamAlignment(i);
182 /// @brief Determine if the function cannot return.
183 bool doesNotReturn() const { return paramHasAttr(0, ParamAttr::NoReturn); }
184 void setDoesNotThrow(bool doesNotThrow = true);
186 /// @brief Determine if the function cannot unwind.
187 bool doesNotThrow() const {
188 return paramHasAttr(0, ParamAttr::NoUnwind);
191 /// @brief Determine if the function does not access memory.
192 bool doesNotAccessMemory() const {
193 return paramHasAttr(0, ParamAttr::ReadNone);
196 /// @brief Determine if the function does not access or only reads memory.
197 bool onlyReadsMemory() const {
198 return doesNotAccessMemory() || paramHasAttr(0, ParamAttr::ReadOnly);
201 /// @brief Determine if the function returns a structure through first
202 /// pointer argument.
203 bool hasStructRetAttr() const {
204 return paramHasAttr(1, ParamAttr::StructRet);
207 /// copyAttributesFrom - copy all additional attributes (those not needed to
208 /// create a Function) from the Function Src to this one.
209 void copyAttributesFrom(const GlobalValue *Src);
211 /// deleteBody - This method deletes the body of the function, and converts
212 /// the linkage to external.
216 setLinkage(ExternalLinkage);
219 /// removeFromParent - This method unlinks 'this' from the containing module,
220 /// but does not delete it.
222 void removeFromParent();
224 /// eraseFromParent - This method unlinks 'this' from the containing module
227 void eraseFromParent();
230 /// Get the underlying elements of the Function... the basic block list is
231 /// empty for external functions.
233 const ArgumentListType &getArgumentList() const {
234 CheckLazyArguments();
237 ArgumentListType &getArgumentList() {
238 CheckLazyArguments();
242 const BasicBlockListType &getBasicBlockList() const { return BasicBlocks; }
243 BasicBlockListType &getBasicBlockList() { return BasicBlocks; }
245 const BasicBlock &getEntryBlock() const { return front(); }
246 BasicBlock &getEntryBlock() { return front(); }
248 //===--------------------------------------------------------------------===//
249 // Symbol Table Accessing functions...
251 /// getSymbolTable() - Return the symbol table...
253 inline ValueSymbolTable &getValueSymbolTable() { return *SymTab; }
254 inline const ValueSymbolTable &getValueSymbolTable() const { return *SymTab; }
257 //===--------------------------------------------------------------------===//
258 // BasicBlock iterator forwarding functions
260 iterator begin() { return BasicBlocks.begin(); }
261 const_iterator begin() const { return BasicBlocks.begin(); }
262 iterator end () { return BasicBlocks.end(); }
263 const_iterator end () const { return BasicBlocks.end(); }
265 size_t size() const { return BasicBlocks.size(); }
266 bool empty() const { return BasicBlocks.empty(); }
267 const BasicBlock &front() const { return BasicBlocks.front(); }
268 BasicBlock &front() { return BasicBlocks.front(); }
269 const BasicBlock &back() const { return BasicBlocks.back(); }
270 BasicBlock &back() { return BasicBlocks.back(); }
272 //===--------------------------------------------------------------------===//
273 // Argument iterator forwarding functions
275 arg_iterator arg_begin() {
276 CheckLazyArguments();
277 return ArgumentList.begin();
279 const_arg_iterator arg_begin() const {
280 CheckLazyArguments();
281 return ArgumentList.begin();
283 arg_iterator arg_end() {
284 CheckLazyArguments();
285 return ArgumentList.end();
287 const_arg_iterator arg_end() const {
288 CheckLazyArguments();
289 return ArgumentList.end();
292 size_t arg_size() const;
293 bool arg_empty() const;
295 virtual void print(std::ostream &OS) const { print(OS, 0); }
296 void print(std::ostream *OS) const { if (OS) print(*OS); }
297 void print(std::ostream &OS, AssemblyAnnotationWriter *AAW) const;
299 /// viewCFG - This function is meant for use from the debugger. You can just
300 /// say 'call F->viewCFG()' and a ghostview window should pop up from the
301 /// program, displaying the CFG of the current function with the code for each
302 /// basic block inside. This depends on there being a 'dot' and 'gv' program
305 void viewCFG() const;
307 /// viewCFGOnly - This function is meant for use from the debugger. It works
308 /// just like viewCFG, but it does not include the contents of basic blocks
309 /// into the nodes, just the label. If you are only interested in the CFG
310 /// this can make the graph smaller.
312 void viewCFGOnly() const;
314 /// Methods for support type inquiry through isa, cast, and dyn_cast:
315 static inline bool classof(const Function *) { return true; }
316 static inline bool classof(const Value *V) {
317 return V->getValueID() == Value::FunctionVal;
320 /// dropAllReferences() - This method causes all the subinstructions to "let
321 /// go" of all references that they are maintaining. This allows one to
322 /// 'delete' a whole module at a time, even though there may be circular
323 /// references... first all references are dropped, and all use counts go to
324 /// zero. Then everything is deleted for real. Note that no operations are
325 /// valid on an object that has "dropped all references", except operator
328 /// Since no other object in the module can have references into the body of a
329 /// function, dropping all references deletes the entire body of the function,
330 /// including any contained basic blocks.
332 void dropAllReferences();
334 static unsigned getBasicBlockListOffset() {
336 return unsigned(reinterpret_cast<uintptr_t>(&Obj->BasicBlocks));
338 static unsigned getArgumentListOffset() {
340 return unsigned(reinterpret_cast<uintptr_t>(&Obj->ArgumentList));
344 inline ValueSymbolTable *
345 ilist_traits<BasicBlock>::getSymTab(Function *F) {
346 return F ? &F->getValueSymbolTable() : 0;
349 inline ValueSymbolTable *
350 ilist_traits<Argument>::getSymTab(Function *F) {
351 return F ? &F->getValueSymbolTable() : 0;
355 ilist_traits<BasicBlock>::getListOffset() {
356 return Function::getBasicBlockListOffset();
360 ilist_traits<Argument>::getListOffset() {
361 return Function::getArgumentListOffset();
365 } // End llvm namespace