1 //===-- llvm/Function.h - Class to represent a single function --*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source 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/ParameterAttributes.h"
25 #include "llvm/Support/Annotation.h"
32 // Traits for intrusive list of instructions...
33 template<> struct ilist_traits<BasicBlock>
34 : public SymbolTableListTraits<BasicBlock, Function> {
36 // createSentinel is used to create a node that marks the end of the list...
37 static BasicBlock *createSentinel();
38 static void destroySentinel(BasicBlock *BB) { delete BB; }
39 static iplist<BasicBlock> &getList(Function *F);
40 static ValueSymbolTable *getSymTab(Function *ItemParent);
41 static int getListOffset();
44 template<> struct ilist_traits<Argument>
45 : public SymbolTableListTraits<Argument, Function> {
47 // createSentinel is used to create a node that marks the end of the list...
48 static Argument *createSentinel();
49 static void destroySentinel(Argument *A) { delete A; }
50 static iplist<Argument> &getList(Function *F);
51 static ValueSymbolTable *getSymTab(Function *ItemParent);
52 static int getListOffset();
55 class Function : public GlobalValue, public Annotable {
57 static void destroyThis(Function*v);
60 typedef iplist<Argument> ArgumentListType;
61 typedef iplist<BasicBlock> BasicBlockListType;
63 // BasicBlock iterators...
64 typedef BasicBlockListType::iterator iterator;
65 typedef BasicBlockListType::const_iterator const_iterator;
67 typedef ArgumentListType::iterator arg_iterator;
68 typedef ArgumentListType::const_iterator const_arg_iterator;
71 // Important things that make up a function!
72 BasicBlockListType BasicBlocks; ///< The basic blocks
73 mutable ArgumentListType ArgumentList; ///< The formal arguments
74 ValueSymbolTable *SymTab; ///< Symbol table of args/instructions
75 const ParamAttrsList *ParamAttrs; ///< Parameter attributes
77 // The Calling Convention is stored in Value::SubclassData.
78 /*unsigned CallingConvention;*/
80 friend class SymbolTableListTraits<Function, Module>;
82 void setParent(Module *parent);
83 Function *Prev, *Next;
84 void setNext(Function *N) { Next = N; }
85 void setPrev(Function *N) { Prev = N; }
87 // getNext/Prev - Return the next or previous function in the list. These
88 // methods should never be used directly, and are only used to implement the
89 // function list as part of the module.
91 Function *getNext() { return Next; }
92 const Function *getNext() const { return Next; }
93 Function *getPrev() { return Prev; }
94 const Function *getPrev() const { return Prev; }
96 /// hasLazyArguments/CheckLazyArguments - The argument list of a function is
97 /// built on demand, so that the list isn't allocated until the first client
98 /// needs it. The hasLazyArguments predicate returns true if the arg list
99 /// hasn't been set up yet.
100 bool hasLazyArguments() const {
101 return SubclassData & 1;
103 void CheckLazyArguments() const {
104 if (hasLazyArguments())
105 BuildLazyArguments();
107 void BuildLazyArguments() const;
109 /// Function ctor - If the (optional) Module argument is specified, the
110 /// function is automatically inserted into the end of the function list for
113 Function(const FunctionType *Ty, LinkageTypes Linkage,
114 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 /// @brief Determine whether the function has the given attribute.
159 bool paramHasAttr(uint16_t i, ParameterAttributes attr) const {
160 return ParamAttrs && ParamAttrs->paramHasAttr(i, attr);
163 /// @brief Determine if the function does not access memory.
164 bool doesNotAccessMemory() const {
165 return paramHasAttr(0, ParamAttr::ReadNone);
168 /// @brief Determine if the function does not access or only reads memory.
169 bool onlyReadsMemory() const {
170 return doesNotAccessMemory() || paramHasAttr(0, ParamAttr::ReadOnly);
173 /// @brief Determine if the function returns a structure.
174 bool isStructReturn() const {
175 return paramHasAttr(1, ParamAttr::StructRet);
178 /// deleteBody - This method deletes the body of the function, and converts
179 /// the linkage to external.
183 setLinkage(ExternalLinkage);
186 /// removeFromParent - This method unlinks 'this' from the containing module,
187 /// but does not delete it.
189 void removeFromParent();
191 /// eraseFromParent - This method unlinks 'this' from the containing module
194 void eraseFromParent();
197 /// Get the underlying elements of the Function... the basic block list is
198 /// empty for external functions.
200 const ArgumentListType &getArgumentList() const {
201 CheckLazyArguments();
204 ArgumentListType &getArgumentList() {
205 CheckLazyArguments();
209 const BasicBlockListType &getBasicBlockList() const { return BasicBlocks; }
210 BasicBlockListType &getBasicBlockList() { return BasicBlocks; }
212 const BasicBlock &getEntryBlock() const { return front(); }
213 BasicBlock &getEntryBlock() { return front(); }
215 //===--------------------------------------------------------------------===//
216 // Symbol Table Accessing functions...
218 /// getSymbolTable() - Return the symbol table...
220 inline ValueSymbolTable &getValueSymbolTable() { return *SymTab; }
221 inline const ValueSymbolTable &getValueSymbolTable() const { return *SymTab; }
224 //===--------------------------------------------------------------------===//
225 // BasicBlock iterator forwarding functions
227 iterator begin() { return BasicBlocks.begin(); }
228 const_iterator begin() const { return BasicBlocks.begin(); }
229 iterator end () { return BasicBlocks.end(); }
230 const_iterator end () const { return BasicBlocks.end(); }
232 size_t size() const { return BasicBlocks.size(); }
233 bool empty() const { return BasicBlocks.empty(); }
234 const BasicBlock &front() const { return BasicBlocks.front(); }
235 BasicBlock &front() { return BasicBlocks.front(); }
236 const BasicBlock &back() const { return BasicBlocks.back(); }
237 BasicBlock &back() { return BasicBlocks.back(); }
239 //===--------------------------------------------------------------------===//
240 // Argument iterator forwarding functions
242 arg_iterator arg_begin() {
243 CheckLazyArguments();
244 return ArgumentList.begin();
246 const_arg_iterator arg_begin() const {
247 CheckLazyArguments();
248 return ArgumentList.begin();
250 arg_iterator arg_end() {
251 CheckLazyArguments();
252 return ArgumentList.end();
254 const_arg_iterator arg_end() const {
255 CheckLazyArguments();
256 return ArgumentList.end();
259 size_t arg_size() const;
260 bool arg_empty() const;
262 virtual void print(std::ostream &OS) const { print(OS, 0); }
263 void print(std::ostream *OS) const { if (OS) print(*OS); }
264 void print(std::ostream &OS, AssemblyAnnotationWriter *AAW) const;
266 /// viewCFG - This function is meant for use from the debugger. You can just
267 /// say 'call F->viewCFG()' and a ghostview window should pop up from the
268 /// program, displaying the CFG of the current function with the code for each
269 /// basic block inside. This depends on there being a 'dot' and 'gv' program
272 void viewCFG() const;
274 /// viewCFGOnly - This function is meant for use from the debugger. It works
275 /// just like viewCFG, but it does not include the contents of basic blocks
276 /// into the nodes, just the label. If you are only interested in the CFG
277 /// this can make the graph smaller.
279 void viewCFGOnly() const;
281 /// Methods for support type inquiry through isa, cast, and dyn_cast:
282 static inline bool classof(const Function *) { return true; }
283 static inline bool classof(const Value *V) {
284 return V->getValueID() == Value::FunctionVal;
287 /// dropAllReferences() - This method causes all the subinstructions to "let
288 /// go" of all references that they are maintaining. This allows one to
289 /// 'delete' a whole module at a time, even though there may be circular
290 /// references... first all references are dropped, and all use counts go to
291 /// zero. Then everything is deleted for real. Note that no operations are
292 /// valid on an object that has "dropped all references", except operator
295 /// Since no other object in the module can have references into the body of a
296 /// function, dropping all references deletes the entire body of the function,
297 /// including any contained basic blocks.
299 void dropAllReferences();
301 static unsigned getBasicBlockListOffset() {
303 return unsigned(reinterpret_cast<uintptr_t>(&Obj->BasicBlocks));
305 static unsigned getArgumentListOffset() {
307 return unsigned(reinterpret_cast<uintptr_t>(&Obj->ArgumentList));
311 inline ValueSymbolTable *
312 ilist_traits<BasicBlock>::getSymTab(Function *F) {
313 return F ? &F->getValueSymbolTable() : 0;
316 inline ValueSymbolTable *
317 ilist_traits<Argument>::getSymTab(Function *F) {
318 return F ? &F->getValueSymbolTable() : 0;
322 ilist_traits<BasicBlock>::getListOffset() {
323 return Function::getBasicBlockListOffset();
327 ilist_traits<Argument>::getListOffset() {
328 return Function::getArgumentListOffset();
332 } // End llvm namespace