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/Attributes.h"
31 // Traits for intrusive list of basic blocks...
32 template<> struct ilist_traits<BasicBlock>
33 : public SymbolTableListTraits<BasicBlock, Function> {
35 // createSentinel is used to get hold of the node that marks the end of the
36 // list... (same trick used here as in ilist_traits<Instruction>)
37 BasicBlock *createSentinel() const {
38 return static_cast<BasicBlock*>(&Sentinel);
40 static void destroySentinel(BasicBlock*) {}
42 BasicBlock *provideInitialHead() const { return createSentinel(); }
43 BasicBlock *ensureHead(BasicBlock*) const { return createSentinel(); }
45 static iplist<BasicBlock> &getList(Function *F);
46 static ValueSymbolTable *getSymTab(Function *ItemParent);
47 static int getListOffset();
49 mutable ilist_node<BasicBlock> Sentinel;
52 template<> struct ilist_traits<Argument>
53 : public SymbolTableListTraits<Argument, Function> {
55 Argument *createSentinel() const {
56 return static_cast<Argument*>(&Sentinel);
58 static void destroySentinel(Argument*) {}
60 Argument *provideInitialHead() const { return createSentinel(); }
61 Argument *ensureHead(Argument*) const { return createSentinel(); }
63 static iplist<Argument> &getList(Function *F);
64 static ValueSymbolTable *getSymTab(Function *ItemParent);
65 static int getListOffset();
67 mutable ilist_node<Argument> Sentinel;
70 class Function : public GlobalValue, public Annotable,
71 public ilist_node<Function> {
73 typedef iplist<Argument> ArgumentListType;
74 typedef iplist<BasicBlock> BasicBlockListType;
76 // BasicBlock iterators...
77 typedef BasicBlockListType::iterator iterator;
78 typedef BasicBlockListType::const_iterator const_iterator;
80 typedef ArgumentListType::iterator arg_iterator;
81 typedef ArgumentListType::const_iterator const_arg_iterator;
84 // Important things that make up a function!
85 BasicBlockListType BasicBlocks; ///< The basic blocks
86 mutable ArgumentListType ArgumentList; ///< The formal arguments
87 ValueSymbolTable *SymTab; ///< Symbol table of args/instructions
88 AttrListPtr AttributeList; ///< Parameter attributes
90 // The Calling Convention is stored in Value::SubclassData.
91 /*unsigned CallingConvention;*/
93 friend class SymbolTableListTraits<Function, Module>;
95 void setParent(Module *parent);
97 /// hasLazyArguments/CheckLazyArguments - The argument list of a function is
98 /// built on demand, so that the list isn't allocated until the first client
99 /// needs it. The hasLazyArguments predicate returns true if the arg list
100 /// hasn't been set up yet.
101 bool hasLazyArguments() const {
102 return SubclassData & 1;
104 void CheckLazyArguments() const {
105 if (hasLazyArguments())
106 BuildLazyArguments();
108 void BuildLazyArguments() const;
110 Function(const Function&); // DO NOT IMPLEMENT
111 void operator=(const Function&); // DO NOT IMPLEMENT
113 /// Function ctor - If the (optional) Module argument is specified, the
114 /// function is automatically inserted into the end of the function list for
117 Function(const FunctionType *Ty, LinkageTypes Linkage,
118 const std::string &N = "", Module *M = 0);
121 static Function *Create(const FunctionType *Ty, LinkageTypes Linkage,
122 const std::string &N = "", Module *M = 0) {
123 return new(0) Function(Ty, Linkage, N, M);
128 const Type *getReturnType() const; // Return the type of the ret val
129 const FunctionType *getFunctionType() const; // Return the FunctionType for me
131 /// isVarArg - Return true if this function takes a variable number of
133 bool isVarArg() const;
135 /// isDeclaration - Is the body of this function unknown? (The basic block
136 /// list is empty if so.) This is true for function declarations, but not
137 /// true for function definitions.
139 virtual bool isDeclaration() const { return BasicBlocks.empty(); }
141 /// getIntrinsicID - This method returns the ID number of the specified
142 /// function, or Intrinsic::not_intrinsic if the function is not an
143 /// instrinsic, or if the pointer is null. This value is always defined to be
144 /// zero to allow easy checking for whether a function is intrinsic or not.
145 /// The particular intrinsic functions which correspond to this value are
146 /// defined in llvm/Intrinsics.h.
148 unsigned getIntrinsicID() const;
149 bool isIntrinsic() const { return getIntrinsicID() != 0; }
151 /// getCallingConv()/setCallingConv(uint) - These method get and set the
152 /// calling convention of this function. The enum values for the known
153 /// calling conventions are defined in CallingConv.h.
154 unsigned getCallingConv() const { return SubclassData >> 1; }
155 void setCallingConv(unsigned CC) {
156 SubclassData = (SubclassData & 1) | (CC << 1);
159 /// getAttributes - Return the attribute list for this Function.
161 const AttrListPtr &getAttributes() const { return AttributeList; }
163 /// setAttributes - Set the attribute list for this Function.
165 void setAttributes(const AttrListPtr &attrs) { AttributeList = attrs; }
167 /// hasFnAttr - Return true if this function has the given attribute.
168 bool hasFnAttr(Attributes N) const {
169 // Function Attributes are stored at ~0 index
170 return AttributeList.paramHasAttr(~0U, N);
173 /// addFnAttr - Add function attributes to this function.
175 void addFnAttr(Attributes N) {
176 // Function Attributes are stored at ~0 index
177 addAttribute(~0U, N);
180 /// removeFnAttr - Remove function attributes from this function.
182 void removeFnAttr(Attributes N) {
183 // Function Attributes are stored at ~0 index
184 removeAttribute(~0U, N);
187 /// hasGC/getGC/setGC/clearGC - The name of the garbage collection algorithm
188 /// to use during code generation.
190 const char *getGC() const;
191 void setGC(const char *Str);
194 /// @brief Determine whether the function has the given attribute.
195 bool paramHasAttr(unsigned i, Attributes attr) const {
196 return AttributeList.paramHasAttr(i, attr);
199 /// addAttribute - adds the attribute to the list of attributes.
200 void addAttribute(unsigned i, Attributes attr);
202 /// removeAttribute - removes the attribute from the list of attributes.
203 void removeAttribute(unsigned i, Attributes attr);
205 /// @brief Extract the alignment for a call or parameter (0=unknown).
206 unsigned getParamAlignment(unsigned i) const {
207 return AttributeList.getParamAlignment(i);
210 /// @brief Determine if the function does not access memory.
211 bool doesNotAccessMemory() const {
212 return hasFnAttr(Attribute::ReadNone);
214 void setDoesNotAccessMemory(bool DoesNotAccessMemory = true) {
215 if (DoesNotAccessMemory) addFnAttr(Attribute::ReadNone);
216 else removeFnAttr(Attribute::ReadNone);
219 /// @brief Determine if the function does not access or only reads memory.
220 bool onlyReadsMemory() const {
221 return doesNotAccessMemory() || hasFnAttr(Attribute::ReadOnly);
223 void setOnlyReadsMemory(bool OnlyReadsMemory = true) {
224 if (OnlyReadsMemory) addFnAttr(Attribute::ReadOnly);
225 else removeFnAttr(Attribute::ReadOnly | Attribute::ReadNone);
228 /// @brief Determine if the function cannot return.
229 bool doesNotReturn() const {
230 return hasFnAttr(Attribute::NoReturn);
232 void setDoesNotReturn(bool DoesNotReturn = true) {
233 if (DoesNotReturn) addFnAttr(Attribute::NoReturn);
234 else removeFnAttr(Attribute::NoReturn);
237 /// @brief Determine if the function cannot unwind.
238 bool doesNotThrow() const {
239 return hasFnAttr(Attribute::NoUnwind);
241 void setDoesNotThrow(bool DoesNotThrow = true) {
242 if (DoesNotThrow) addFnAttr(Attribute::NoUnwind);
243 else removeFnAttr(Attribute::NoUnwind);
246 /// @brief Determine if the function returns a structure through first
247 /// pointer argument.
248 bool hasStructRetAttr() const {
249 return paramHasAttr(1, Attribute::StructRet);
252 /// @brief Determine if the parameter does not alias other parameters.
253 /// @param n The parameter to check. 1 is the first parameter, 0 is the return
254 bool doesNotAlias(unsigned n) const {
255 return paramHasAttr(n, Attribute::NoAlias);
257 void setDoesNotAlias(unsigned n, bool DoesNotAlias = true) {
258 if (DoesNotAlias) addAttribute(n, Attribute::NoAlias);
259 else removeAttribute(n, Attribute::NoAlias);
262 /// @brief Determine if the parameter can be captured.
263 /// @param n The parameter to check. 1 is the first parameter, 0 is the return
264 bool doesNotCapture(unsigned n) const {
265 return paramHasAttr(n, Attribute::NoCapture);
267 void setDoesNotCapture(unsigned n, bool DoesNotCapture = true) {
268 if (DoesNotCapture) addAttribute(n, Attribute::NoCapture);
269 else removeAttribute(n, Attribute::NoCapture);
272 /// copyAttributesFrom - copy all additional attributes (those not needed to
273 /// create a Function) from the Function Src to this one.
274 void copyAttributesFrom(const GlobalValue *Src);
276 /// deleteBody - This method deletes the body of the function, and converts
277 /// the linkage to external.
281 setLinkage(ExternalLinkage);
284 /// removeFromParent - This method unlinks 'this' from the containing module,
285 /// but does not delete it.
287 virtual void removeFromParent();
289 /// eraseFromParent - This method unlinks 'this' from the containing module
292 virtual void eraseFromParent();
295 /// Get the underlying elements of the Function... the basic block list is
296 /// empty for external functions.
298 const ArgumentListType &getArgumentList() const {
299 CheckLazyArguments();
302 ArgumentListType &getArgumentList() {
303 CheckLazyArguments();
307 const BasicBlockListType &getBasicBlockList() const { return BasicBlocks; }
308 BasicBlockListType &getBasicBlockList() { return BasicBlocks; }
310 const BasicBlock &getEntryBlock() const { return front(); }
311 BasicBlock &getEntryBlock() { return front(); }
313 //===--------------------------------------------------------------------===//
314 // Symbol Table Accessing functions...
316 /// getSymbolTable() - Return the symbol table...
318 inline ValueSymbolTable &getValueSymbolTable() { return *SymTab; }
319 inline const ValueSymbolTable &getValueSymbolTable() const { return *SymTab; }
322 //===--------------------------------------------------------------------===//
323 // BasicBlock iterator forwarding functions
325 iterator begin() { return BasicBlocks.begin(); }
326 const_iterator begin() const { return BasicBlocks.begin(); }
327 iterator end () { return BasicBlocks.end(); }
328 const_iterator end () const { return BasicBlocks.end(); }
330 size_t size() const { return BasicBlocks.size(); }
331 bool empty() const { return BasicBlocks.empty(); }
332 const BasicBlock &front() const { return BasicBlocks.front(); }
333 BasicBlock &front() { return BasicBlocks.front(); }
334 const BasicBlock &back() const { return BasicBlocks.back(); }
335 BasicBlock &back() { return BasicBlocks.back(); }
337 //===--------------------------------------------------------------------===//
338 // Argument iterator forwarding functions
340 arg_iterator arg_begin() {
341 CheckLazyArguments();
342 return ArgumentList.begin();
344 const_arg_iterator arg_begin() const {
345 CheckLazyArguments();
346 return ArgumentList.begin();
348 arg_iterator arg_end() {
349 CheckLazyArguments();
350 return ArgumentList.end();
352 const_arg_iterator arg_end() const {
353 CheckLazyArguments();
354 return ArgumentList.end();
357 size_t arg_size() const;
358 bool arg_empty() const;
360 /// viewCFG - This function is meant for use from the debugger. You can just
361 /// say 'call F->viewCFG()' and a ghostview window should pop up from the
362 /// program, displaying the CFG of the current function with the code for each
363 /// basic block inside. This depends on there being a 'dot' and 'gv' program
366 void viewCFG() const;
368 /// viewCFGOnly - This function is meant for use from the debugger. It works
369 /// just like viewCFG, but it does not include the contents of basic blocks
370 /// into the nodes, just the label. If you are only interested in the CFG
371 /// this can make the graph smaller.
373 void viewCFGOnly() const;
375 /// Methods for support type inquiry through isa, cast, and dyn_cast:
376 static inline bool classof(const Function *) { return true; }
377 static inline bool classof(const Value *V) {
378 return V->getValueID() == Value::FunctionVal;
381 /// dropAllReferences() - This method causes all the subinstructions to "let
382 /// go" of all references that they are maintaining. This allows one to
383 /// 'delete' a whole module at a time, even though there may be circular
384 /// references... first all references are dropped, and all use counts go to
385 /// zero. Then everything is deleted for real. Note that no operations are
386 /// valid on an object that has "dropped all references", except operator
389 /// Since no other object in the module can have references into the body of a
390 /// function, dropping all references deletes the entire body of the function,
391 /// including any contained basic blocks.
393 void dropAllReferences();
395 static unsigned getBasicBlockListOffset() {
397 return unsigned(reinterpret_cast<uintptr_t>(&Obj->BasicBlocks));
399 static unsigned getArgumentListOffset() {
401 return unsigned(reinterpret_cast<uintptr_t>(&Obj->ArgumentList));
405 inline ValueSymbolTable *
406 ilist_traits<BasicBlock>::getSymTab(Function *F) {
407 return F ? &F->getValueSymbolTable() : 0;
410 inline ValueSymbolTable *
411 ilist_traits<Argument>::getSymTab(Function *F) {
412 return F ? &F->getValueSymbolTable() : 0;
416 ilist_traits<BasicBlock>::getListOffset() {
417 return Function::getBasicBlockListOffset();
421 ilist_traits<Argument>::getListOffset() {
422 return Function::getArgumentListOffset();
426 } // End llvm namespace