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,
55 public ilist_node<Function> {
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 PAListPtr 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);
81 /// hasLazyArguments/CheckLazyArguments - The argument list of a function is
82 /// built on demand, so that the list isn't allocated until the first client
83 /// needs it. The hasLazyArguments predicate returns true if the arg list
84 /// hasn't been set up yet.
85 bool hasLazyArguments() const {
86 return SubclassData & 1;
88 void CheckLazyArguments() const {
89 if (hasLazyArguments())
92 void BuildLazyArguments() const;
94 Function(const Function&); // DO NOT IMPLEMENT
95 void operator=(const Function&); // DO NOT IMPLEMENT
97 /// Function ctor - If the (optional) Module argument is specified, the
98 /// function is automatically inserted into the end of the function list for
101 Function(const FunctionType *Ty, LinkageTypes Linkage,
102 const std::string &N = "", Module *M = 0);
105 static Function *Create(const FunctionType *Ty, LinkageTypes Linkage,
106 const std::string &N = "", Module *M = 0) {
107 return new(0) Function(Ty, Linkage, N, M);
112 const Type *getReturnType() const; // Return the type of the ret val
113 const FunctionType *getFunctionType() const; // Return the FunctionType for me
115 /// isVarArg - Return true if this function takes a variable number of
117 bool isVarArg() const;
119 /// isDeclaration - Is the body of this function unknown? (The basic block
120 /// list is empty if so.) This is true for function declarations, but not
121 /// true for function definitions.
123 virtual bool isDeclaration() const { return BasicBlocks.empty(); }
125 /// getIntrinsicID - This method returns the ID number of the specified
126 /// function, or Intrinsic::not_intrinsic if the function is not an
127 /// instrinsic, or if the pointer is null. This value is always defined to be
128 /// zero to allow easy checking for whether a function is intrinsic or not.
129 /// The particular intrinsic functions which correspond to this value are
130 /// defined in llvm/Intrinsics.h.
132 unsigned getIntrinsicID(bool noAssert = false) const;
133 bool isIntrinsic() const { return getIntrinsicID() != 0; }
135 /// getCallingConv()/setCallingConv(uint) - These method get and set the
136 /// calling convention of this function. The enum values for the known
137 /// calling conventions are defined in CallingConv.h.
138 unsigned getCallingConv() const { return SubclassData >> 1; }
139 void setCallingConv(unsigned CC) {
140 SubclassData = (SubclassData & 1) | (CC << 1);
143 /// getParamAttrs - Return the parameter attributes for this Function.
145 const PAListPtr &getParamAttrs() const { return ParamAttrs; }
147 /// setParamAttrs - Set the parameter attributes for this Function.
149 void setParamAttrs(const PAListPtr &attrs) { ParamAttrs = attrs; }
151 /// hasGC/getGC/setGC/clearGC - The name of the garbage collection algorithm
152 /// to use during code generation.
154 const char *getGC() const;
155 void setGC(const char *Str);
158 /// @brief Determine whether the function has the given attribute.
159 bool paramHasAttr(unsigned i, ParameterAttributes attr) const {
160 return ParamAttrs.paramHasAttr(i, attr);
163 /// addParamAttr - adds the attribute to the list of attributes.
164 void addParamAttr(unsigned i, ParameterAttributes attr);
166 /// removeParamAttr - removes the attribute from the list of attributes.
167 void removeParamAttr(unsigned i, ParameterAttributes attr);
169 /// @brief Extract the alignment for a call or parameter (0=unknown).
170 unsigned getParamAlignment(unsigned i) const {
171 return ParamAttrs.getParamAlignment(i);
174 /// @brief Determine if the function does not access memory.
175 bool doesNotAccessMemory() const {
176 return paramHasAttr(0, ParamAttr::ReadNone);
178 void setDoesNotAccessMemory(bool DoesNotAccessMemory = true) {
179 if (DoesNotAccessMemory) addParamAttr(0, ParamAttr::ReadNone);
180 else removeParamAttr(0, ParamAttr::ReadNone);
183 /// @brief Determine if the function does not access or only reads memory.
184 bool onlyReadsMemory() const {
185 return doesNotAccessMemory() || paramHasAttr(0, ParamAttr::ReadOnly);
187 void setOnlyReadsMemory(bool OnlyReadsMemory = true) {
188 if (OnlyReadsMemory) addParamAttr(0, ParamAttr::ReadOnly);
189 else removeParamAttr(0, ParamAttr::ReadOnly | ParamAttr::ReadNone);
192 /// @brief Determine if the function cannot return.
193 bool doesNotReturn() const {
194 return paramHasAttr(0, ParamAttr::NoReturn);
196 void setDoesNotReturn(bool DoesNotReturn = true) {
197 if (DoesNotReturn) addParamAttr(0, ParamAttr::NoReturn);
198 else removeParamAttr(0, ParamAttr::NoReturn);
201 /// @brief Determine if the function cannot unwind.
202 bool doesNotThrow() const {
203 return paramHasAttr(0, ParamAttr::NoUnwind);
205 void setDoesNotThrow(bool DoesNotThrow = true) {
206 if (DoesNotThrow) addParamAttr(0, ParamAttr::NoUnwind);
207 else removeParamAttr(0, ParamAttr::NoUnwind);
210 /// @brief Determine if the function returns a structure through first
211 /// pointer argument.
212 bool hasStructRetAttr() const {
213 return paramHasAttr(1, ParamAttr::StructRet);
216 /// copyAttributesFrom - copy all additional attributes (those not needed to
217 /// create a Function) from the Function Src to this one.
218 void copyAttributesFrom(const GlobalValue *Src);
220 /// deleteBody - This method deletes the body of the function, and converts
221 /// the linkage to external.
225 setLinkage(ExternalLinkage);
228 /// removeFromParent - This method unlinks 'this' from the containing module,
229 /// but does not delete it.
231 void removeFromParent();
233 /// eraseFromParent - This method unlinks 'this' from the containing module
236 void eraseFromParent();
239 /// Get the underlying elements of the Function... the basic block list is
240 /// empty for external functions.
242 const ArgumentListType &getArgumentList() const {
243 CheckLazyArguments();
246 ArgumentListType &getArgumentList() {
247 CheckLazyArguments();
251 const BasicBlockListType &getBasicBlockList() const { return BasicBlocks; }
252 BasicBlockListType &getBasicBlockList() { return BasicBlocks; }
254 const BasicBlock &getEntryBlock() const { return front(); }
255 BasicBlock &getEntryBlock() { return front(); }
257 //===--------------------------------------------------------------------===//
258 // Symbol Table Accessing functions...
260 /// getSymbolTable() - Return the symbol table...
262 inline ValueSymbolTable &getValueSymbolTable() { return *SymTab; }
263 inline const ValueSymbolTable &getValueSymbolTable() const { return *SymTab; }
266 //===--------------------------------------------------------------------===//
267 // BasicBlock iterator forwarding functions
269 iterator begin() { return BasicBlocks.begin(); }
270 const_iterator begin() const { return BasicBlocks.begin(); }
271 iterator end () { return BasicBlocks.end(); }
272 const_iterator end () const { return BasicBlocks.end(); }
274 size_t size() const { return BasicBlocks.size(); }
275 bool empty() const { return BasicBlocks.empty(); }
276 const BasicBlock &front() const { return BasicBlocks.front(); }
277 BasicBlock &front() { return BasicBlocks.front(); }
278 const BasicBlock &back() const { return BasicBlocks.back(); }
279 BasicBlock &back() { return BasicBlocks.back(); }
281 //===--------------------------------------------------------------------===//
282 // Argument iterator forwarding functions
284 arg_iterator arg_begin() {
285 CheckLazyArguments();
286 return ArgumentList.begin();
288 const_arg_iterator arg_begin() const {
289 CheckLazyArguments();
290 return ArgumentList.begin();
292 arg_iterator arg_end() {
293 CheckLazyArguments();
294 return ArgumentList.end();
296 const_arg_iterator arg_end() const {
297 CheckLazyArguments();
298 return ArgumentList.end();
301 size_t arg_size() const;
302 bool arg_empty() const;
304 /// viewCFG - This function is meant for use from the debugger. You can just
305 /// say 'call F->viewCFG()' and a ghostview window should pop up from the
306 /// program, displaying the CFG of the current function with the code for each
307 /// basic block inside. This depends on there being a 'dot' and 'gv' program
310 void viewCFG() const;
312 /// viewCFGOnly - This function is meant for use from the debugger. It works
313 /// just like viewCFG, but it does not include the contents of basic blocks
314 /// into the nodes, just the label. If you are only interested in the CFG
315 /// this can make the graph smaller.
317 void viewCFGOnly() const;
319 /// Methods for support type inquiry through isa, cast, and dyn_cast:
320 static inline bool classof(const Function *) { return true; }
321 static inline bool classof(const Value *V) {
322 return V->getValueID() == Value::FunctionVal;
325 /// dropAllReferences() - This method causes all the subinstructions to "let
326 /// go" of all references that they are maintaining. This allows one to
327 /// 'delete' a whole module at a time, even though there may be circular
328 /// references... first all references are dropped, and all use counts go to
329 /// zero. Then everything is deleted for real. Note that no operations are
330 /// valid on an object that has "dropped all references", except operator
333 /// Since no other object in the module can have references into the body of a
334 /// function, dropping all references deletes the entire body of the function,
335 /// including any contained basic blocks.
337 void dropAllReferences();
339 static unsigned getBasicBlockListOffset() {
341 return unsigned(reinterpret_cast<uintptr_t>(&Obj->BasicBlocks));
343 static unsigned getArgumentListOffset() {
345 return unsigned(reinterpret_cast<uintptr_t>(&Obj->ArgumentList));
349 inline ValueSymbolTable *
350 ilist_traits<BasicBlock>::getSymTab(Function *F) {
351 return F ? &F->getValueSymbolTable() : 0;
354 inline ValueSymbolTable *
355 ilist_traits<Argument>::getSymTab(Function *F) {
356 return F ? &F->getValueSymbolTable() : 0;
360 ilist_traits<BasicBlock>::getListOffset() {
361 return Function::getBasicBlockListOffset();
365 ilist_traits<Argument>::getListOffset() {
366 return Function::getArgumentListOffset();
370 } // End llvm namespace