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"
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 typedef iplist<Argument> ArgumentListType;
58 typedef iplist<BasicBlock> BasicBlockListType;
60 // BasicBlock iterators...
61 typedef BasicBlockListType::iterator iterator;
62 typedef BasicBlockListType::const_iterator const_iterator;
64 typedef ArgumentListType::iterator arg_iterator;
65 typedef ArgumentListType::const_iterator const_arg_iterator;
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 const ParamAttrsList *ParamAttrs; ///< Parameter attributes
74 // The Calling Convention is stored in Value::SubclassData.
75 /*unsigned CallingConvention;*/
77 friend class SymbolTableListTraits<Function, Module>;
79 void setParent(Module *parent);
80 Function *Prev, *Next;
81 void setNext(Function *N) { Next = N; }
82 void setPrev(Function *N) { Prev = N; }
84 // getNext/Prev - Return the next or previous function in the list. These
85 // methods should never be used directly, and are only used to implement the
86 // function list as part of the module.
88 Function *getNext() { return Next; }
89 const Function *getNext() const { return Next; }
90 Function *getPrev() { return Prev; }
91 const Function *getPrev() const { return Prev; }
93 /// hasLazyArguments/CheckLazyArguments - The argument list of a function is
94 /// built on demand, so that the list isn't allocated until the first client
95 /// needs it. The hasLazyArguments predicate returns true if the arg list
96 /// hasn't been set up yet.
97 bool hasLazyArguments() const {
98 return SubclassData & 1;
100 void CheckLazyArguments() const {
101 if (hasLazyArguments())
102 BuildLazyArguments();
104 void BuildLazyArguments() const;
106 Function(const Function&); // DO NOT IMPLEMENT
107 void operator=(const Function&); // DO NOT IMPLEMENT
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);
117 const Type *getReturnType() const; // Return the type of the ret val
118 const FunctionType *getFunctionType() const; // Return the FunctionType for me
120 /// isVarArg - Return true if this function takes a variable number of
122 bool isVarArg() const;
124 /// isDeclaration - Is the body of this function unknown? (The basic block
125 /// list is empty if so.) This is true for function declarations, but not
126 /// true for function definitions.
128 virtual bool isDeclaration() const { return BasicBlocks.empty(); }
130 /// getIntrinsicID - This method returns the ID number of the specified
131 /// function, or Intrinsic::not_intrinsic if the function is not an
132 /// instrinsic, or if the pointer is null. This value is always defined to be
133 /// zero to allow easy checking for whether a function is intrinsic or not.
134 /// The particular intrinsic functions which correspond to this value are
135 /// defined in llvm/Intrinsics.h.
137 unsigned getIntrinsicID(bool noAssert = false) const;
138 bool isIntrinsic() const { return getIntrinsicID() != 0; }
140 /// getCallingConv()/setCallingConv(uint) - These method get and set the
141 /// calling convention of this function. The enum values for the known
142 /// calling conventions are defined in CallingConv.h.
143 unsigned getCallingConv() const { return SubclassData >> 1; }
144 void setCallingConv(unsigned CC) {
145 SubclassData = (SubclassData & 1) | (CC << 1);
148 /// Obtains a constant pointer to the ParamAttrsList object which holds the
149 /// parameter attributes information, if any.
150 /// @returns 0 if no parameter attributes have been set.
151 /// @brief Get the parameter attributes.
152 const ParamAttrsList *getParamAttrs() const { return ParamAttrs; }
154 /// Sets the parameter attributes for this Function. To construct a
155 /// ParamAttrsList, see ParameterAttributes.h
156 /// @brief Set the parameter attributes.
157 void setParamAttrs(const ParamAttrsList *attrs);
159 /// hasCollector/getCollector/setCollector/clearCollector - The name of the
160 /// garbage collection algorithm to use during code generation.
161 bool hasCollector() const;
162 const char *getCollector() const;
163 void setCollector(const char *Str);
164 void clearCollector();
166 /// @brief Determine whether the function has the given attribute.
167 bool paramHasAttr(uint16_t i, ParameterAttributes attr) const;
169 /// @brief Determine if the function cannot return.
170 bool doesNotReturn() const;
172 /// @brief Determine if the function cannot unwind.
173 bool doesNotThrow() const;
175 /// @brief Determine if the function does not access memory.
176 bool doesNotAccessMemory() const;
178 /// @brief Determine if the function does not access or only reads memory.
179 bool onlyReadsMemory() const;
181 /// @brief Determine if the function returns a structure.
182 bool isStructReturn() const;
184 /// deleteBody - This method deletes the body of the function, and converts
185 /// the linkage to external.
189 setLinkage(ExternalLinkage);
192 /// removeFromParent - This method unlinks 'this' from the containing module,
193 /// but does not delete it.
195 void removeFromParent();
197 /// eraseFromParent - This method unlinks 'this' from the containing module
200 void eraseFromParent();
203 /// Get the underlying elements of the Function... the basic block list is
204 /// empty for external functions.
206 const ArgumentListType &getArgumentList() const {
207 CheckLazyArguments();
210 ArgumentListType &getArgumentList() {
211 CheckLazyArguments();
215 const BasicBlockListType &getBasicBlockList() const { return BasicBlocks; }
216 BasicBlockListType &getBasicBlockList() { return BasicBlocks; }
218 const BasicBlock &getEntryBlock() const { return front(); }
219 BasicBlock &getEntryBlock() { return front(); }
221 //===--------------------------------------------------------------------===//
222 // Symbol Table Accessing functions...
224 /// getSymbolTable() - Return the symbol table...
226 inline ValueSymbolTable &getValueSymbolTable() { return *SymTab; }
227 inline const ValueSymbolTable &getValueSymbolTable() const { return *SymTab; }
230 //===--------------------------------------------------------------------===//
231 // BasicBlock iterator forwarding functions
233 iterator begin() { return BasicBlocks.begin(); }
234 const_iterator begin() const { return BasicBlocks.begin(); }
235 iterator end () { return BasicBlocks.end(); }
236 const_iterator end () const { return BasicBlocks.end(); }
238 size_t size() const { return BasicBlocks.size(); }
239 bool empty() const { return BasicBlocks.empty(); }
240 const BasicBlock &front() const { return BasicBlocks.front(); }
241 BasicBlock &front() { return BasicBlocks.front(); }
242 const BasicBlock &back() const { return BasicBlocks.back(); }
243 BasicBlock &back() { return BasicBlocks.back(); }
245 //===--------------------------------------------------------------------===//
246 // Argument iterator forwarding functions
248 arg_iterator arg_begin() {
249 CheckLazyArguments();
250 return ArgumentList.begin();
252 const_arg_iterator arg_begin() const {
253 CheckLazyArguments();
254 return ArgumentList.begin();
256 arg_iterator arg_end() {
257 CheckLazyArguments();
258 return ArgumentList.end();
260 const_arg_iterator arg_end() const {
261 CheckLazyArguments();
262 return ArgumentList.end();
265 size_t arg_size() const;
266 bool arg_empty() const;
268 virtual void print(std::ostream &OS) const { print(OS, 0); }
269 void print(std::ostream *OS) const { if (OS) print(*OS); }
270 void print(std::ostream &OS, AssemblyAnnotationWriter *AAW) const;
272 /// viewCFG - This function is meant for use from the debugger. You can just
273 /// say 'call F->viewCFG()' and a ghostview window should pop up from the
274 /// program, displaying the CFG of the current function with the code for each
275 /// basic block inside. This depends on there being a 'dot' and 'gv' program
278 void viewCFG() const;
280 /// viewCFGOnly - This function is meant for use from the debugger. It works
281 /// just like viewCFG, but it does not include the contents of basic blocks
282 /// into the nodes, just the label. If you are only interested in the CFG
283 /// this can make the graph smaller.
285 void viewCFGOnly() const;
287 /// Methods for support type inquiry through isa, cast, and dyn_cast:
288 static inline bool classof(const Function *) { return true; }
289 static inline bool classof(const Value *V) {
290 return V->getValueID() == Value::FunctionVal;
293 /// dropAllReferences() - This method causes all the subinstructions to "let
294 /// go" of all references that they are maintaining. This allows one to
295 /// 'delete' a whole module at a time, even though there may be circular
296 /// references... first all references are dropped, and all use counts go to
297 /// zero. Then everything is deleted for real. Note that no operations are
298 /// valid on an object that has "dropped all references", except operator
301 /// Since no other object in the module can have references into the body of a
302 /// function, dropping all references deletes the entire body of the function,
303 /// including any contained basic blocks.
305 void dropAllReferences();
307 static unsigned getBasicBlockListOffset() {
309 return unsigned(reinterpret_cast<uintptr_t>(&Obj->BasicBlocks));
311 static unsigned getArgumentListOffset() {
313 return unsigned(reinterpret_cast<uintptr_t>(&Obj->ArgumentList));
317 inline ValueSymbolTable *
318 ilist_traits<BasicBlock>::getSymTab(Function *F) {
319 return F ? &F->getValueSymbolTable() : 0;
322 inline ValueSymbolTable *
323 ilist_traits<Argument>::getSymTab(Function *F) {
324 return F ? &F->getValueSymbolTable() : 0;
328 ilist_traits<BasicBlock>::getListOffset() {
329 return Function::getBasicBlockListOffset();
333 ilist_traits<Argument>::getListOffset() {
334 return Function::getArgumentListOffset();
338 } // End llvm namespace