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"
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 const ParamAttrsList *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 const Type *getReturnType() const; // Return the type of the ret val
117 const FunctionType *getFunctionType() const; // Return the FunctionType for me
119 /// isVarArg - Return true if this function takes a variable number of
121 bool isVarArg() const;
123 /// isDeclaration - Is the body of this function unknown? (The basic block
124 /// list is empty if so.) This is true for function declarations, but not
125 /// true for function definitions.
127 virtual bool isDeclaration() const { return BasicBlocks.empty(); }
129 /// getIntrinsicID - This method returns the ID number of the specified
130 /// function, or Intrinsic::not_intrinsic if the function is not an
131 /// instrinsic, or if the pointer is null. This value is always defined to be
132 /// zero to allow easy checking for whether a function is intrinsic or not.
133 /// The particular intrinsic functions which correspond to this value are
134 /// defined in llvm/Intrinsics.h.
136 unsigned getIntrinsicID(bool noAssert = false) const;
137 bool isIntrinsic() const { return getIntrinsicID() != 0; }
139 /// getCallingConv()/setCallingConv(uint) - These method get and set the
140 /// calling convention of this function. The enum values for the known
141 /// calling conventions are defined in CallingConv.h.
142 unsigned getCallingConv() const { return SubclassData >> 1; }
143 void setCallingConv(unsigned CC) {
144 SubclassData = (SubclassData & 1) | (CC << 1);
147 /// Obtains a constant pointer to the ParamAttrsList object which holds the
148 /// parameter attributes information, if any.
149 /// @returns 0 if no parameter attributes have been set.
150 /// @brief Get the parameter attributes.
151 const ParamAttrsList *getParamAttrs() const { return ParamAttrs; }
153 /// Sets the parameter attributes for this Function. To construct a
154 /// ParamAttrsList, see ParameterAttributes.h
155 /// @brief Set the parameter attributes.
156 void setParamAttrs(const ParamAttrsList *attrs);
158 /// hasCollector/getCollector/setCollector/clearCollector - The name of the
159 /// garbage collection algorithm to use during code generation.
160 bool hasCollector() const;
161 const char *getCollector() const;
162 void setCollector(const char *Str);
163 void clearCollector();
165 /// @brief Determine whether the function has the given attribute.
166 bool paramHasAttr(uint16_t i, unsigned attr) const;
168 /// @brief Determine if the function cannot return.
169 bool doesNotReturn() const;
171 /// @brief Determine if the function cannot unwind.
172 bool doesNotThrow() const;
174 /// @brief Determine if the function does not access memory.
175 bool doesNotAccessMemory() const;
177 /// @brief Determine if the function does not access or only reads memory.
178 bool onlyReadsMemory() const;
180 /// @brief Determine if the function returns a structure.
181 bool isStructReturn() const;
183 /// deleteBody - This method deletes the body of the function, and converts
184 /// the linkage to external.
188 setLinkage(ExternalLinkage);
191 /// removeFromParent - This method unlinks 'this' from the containing module,
192 /// but does not delete it.
194 void removeFromParent();
196 /// eraseFromParent - This method unlinks 'this' from the containing module
199 void eraseFromParent();
202 /// Get the underlying elements of the Function... the basic block list is
203 /// empty for external functions.
205 const ArgumentListType &getArgumentList() const {
206 CheckLazyArguments();
209 ArgumentListType &getArgumentList() {
210 CheckLazyArguments();
214 const BasicBlockListType &getBasicBlockList() const { return BasicBlocks; }
215 BasicBlockListType &getBasicBlockList() { return BasicBlocks; }
217 const BasicBlock &getEntryBlock() const { return front(); }
218 BasicBlock &getEntryBlock() { return front(); }
220 //===--------------------------------------------------------------------===//
221 // Symbol Table Accessing functions...
223 /// getSymbolTable() - Return the symbol table...
225 inline ValueSymbolTable &getValueSymbolTable() { return *SymTab; }
226 inline const ValueSymbolTable &getValueSymbolTable() const { return *SymTab; }
229 //===--------------------------------------------------------------------===//
230 // BasicBlock iterator forwarding functions
232 iterator begin() { return BasicBlocks.begin(); }
233 const_iterator begin() const { return BasicBlocks.begin(); }
234 iterator end () { return BasicBlocks.end(); }
235 const_iterator end () const { return BasicBlocks.end(); }
237 size_t size() const { return BasicBlocks.size(); }
238 bool empty() const { return BasicBlocks.empty(); }
239 const BasicBlock &front() const { return BasicBlocks.front(); }
240 BasicBlock &front() { return BasicBlocks.front(); }
241 const BasicBlock &back() const { return BasicBlocks.back(); }
242 BasicBlock &back() { return BasicBlocks.back(); }
244 //===--------------------------------------------------------------------===//
245 // Argument iterator forwarding functions
247 arg_iterator arg_begin() {
248 CheckLazyArguments();
249 return ArgumentList.begin();
251 const_arg_iterator arg_begin() const {
252 CheckLazyArguments();
253 return ArgumentList.begin();
255 arg_iterator arg_end() {
256 CheckLazyArguments();
257 return ArgumentList.end();
259 const_arg_iterator arg_end() const {
260 CheckLazyArguments();
261 return ArgumentList.end();
264 size_t arg_size() const;
265 bool arg_empty() const;
267 virtual void print(std::ostream &OS) const { print(OS, 0); }
268 void print(std::ostream *OS) const { if (OS) print(*OS); }
269 void print(std::ostream &OS, AssemblyAnnotationWriter *AAW) const;
271 /// viewCFG - This function is meant for use from the debugger. You can just
272 /// say 'call F->viewCFG()' and a ghostview window should pop up from the
273 /// program, displaying the CFG of the current function with the code for each
274 /// basic block inside. This depends on there being a 'dot' and 'gv' program
277 void viewCFG() const;
279 /// viewCFGOnly - This function is meant for use from the debugger. It works
280 /// just like viewCFG, but it does not include the contents of basic blocks
281 /// into the nodes, just the label. If you are only interested in the CFG
282 /// this can make the graph smaller.
284 void viewCFGOnly() const;
286 /// Methods for support type inquiry through isa, cast, and dyn_cast:
287 static inline bool classof(const Function *) { return true; }
288 static inline bool classof(const Value *V) {
289 return V->getValueID() == Value::FunctionVal;
292 /// dropAllReferences() - This method causes all the subinstructions to "let
293 /// go" of all references that they are maintaining. This allows one to
294 /// 'delete' a whole module at a time, even though there may be circular
295 /// references... first all references are dropped, and all use counts go to
296 /// zero. Then everything is deleted for real. Note that no operations are
297 /// valid on an object that has "dropped all references", except operator
300 /// Since no other object in the module can have references into the body of a
301 /// function, dropping all references deletes the entire body of the function,
302 /// including any contained basic blocks.
304 void dropAllReferences();
306 static unsigned getBasicBlockListOffset() {
308 return unsigned(reinterpret_cast<uintptr_t>(&Obj->BasicBlocks));
310 static unsigned getArgumentListOffset() {
312 return unsigned(reinterpret_cast<uintptr_t>(&Obj->ArgumentList));
316 inline ValueSymbolTable *
317 ilist_traits<BasicBlock>::getSymTab(Function *F) {
318 return F ? &F->getValueSymbolTable() : 0;
321 inline ValueSymbolTable *
322 ilist_traits<Argument>::getSymTab(Function *F) {
323 return F ? &F->getValueSymbolTable() : 0;
327 ilist_traits<BasicBlock>::getListOffset() {
328 return Function::getBasicBlockListOffset();
332 ilist_traits<Argument>::getListOffset() {
333 return Function::getArgumentListOffset();
337 } // End llvm namespace