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/CallingConv.h"
23 #include "llvm/BasicBlock.h"
24 #include "llvm/Argument.h"
25 #include "llvm/Attributes.h"
26 #include "llvm/Support/Compiler.h"
33 // Traits for intrusive list of basic blocks...
34 template<> struct ilist_traits<BasicBlock>
35 : public SymbolTableListTraits<BasicBlock, Function> {
37 // createSentinel is used to get hold of the node that marks the end of the
38 // list... (same trick used here as in ilist_traits<Instruction>)
39 BasicBlock *createSentinel() const {
40 return static_cast<BasicBlock*>(&Sentinel);
42 static void destroySentinel(BasicBlock*) {}
44 BasicBlock *provideInitialHead() const { return createSentinel(); }
45 BasicBlock *ensureHead(BasicBlock*) const { return createSentinel(); }
46 static void noteHead(BasicBlock*, BasicBlock*) {}
48 static ValueSymbolTable *getSymTab(Function *ItemParent);
50 mutable ilist_half_node<BasicBlock> Sentinel;
53 template<> struct ilist_traits<Argument>
54 : public SymbolTableListTraits<Argument, Function> {
56 Argument *createSentinel() const {
57 return static_cast<Argument*>(&Sentinel);
59 static void destroySentinel(Argument*) {}
61 Argument *provideInitialHead() const { return createSentinel(); }
62 Argument *ensureHead(Argument*) const { return createSentinel(); }
63 static void noteHead(Argument*, Argument*) {}
65 static ValueSymbolTable *getSymTab(Function *ItemParent);
67 mutable ilist_half_node<Argument> Sentinel;
70 class Function : public GlobalValue,
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 /*CallingConv::ID 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 Twine &N = "", Module *M = 0);
121 static Function *Create(const FunctionType *Ty, LinkageTypes Linkage,
122 const Twine &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 /// getContext - Return a pointer to the LLVMContext associated with this
132 /// function, or NULL if this function is not bound to a context yet.
133 LLVMContext &getContext() const;
135 /// isVarArg - Return true if this function takes a variable number of
137 bool isVarArg() const;
139 /// isDeclaration - Is the body of this function unknown? (The basic block
140 /// list is empty if so.) This is true for function declarations, but not
141 /// true for function definitions.
143 virtual bool isDeclaration() const { return BasicBlocks.empty(); }
145 /// getIntrinsicID - This method returns the ID number of the specified
146 /// function, or Intrinsic::not_intrinsic if the function is not an
147 /// instrinsic, or if the pointer is null. This value is always defined to be
148 /// zero to allow easy checking for whether a function is intrinsic or not.
149 /// The particular intrinsic functions which correspond to this value are
150 /// defined in llvm/Intrinsics.h.
152 unsigned getIntrinsicID() const ATTRIBUTE_READONLY;
153 bool isIntrinsic() const { return getIntrinsicID() != 0; }
155 /// getCallingConv()/setCallingConv(CC) - These method get and set the
156 /// calling convention of this function. The enum values for the known
157 /// calling conventions are defined in CallingConv.h.
158 CallingConv::ID getCallingConv() const {
159 return static_cast<CallingConv::ID>(SubclassData >> 1);
161 void setCallingConv(CallingConv::ID CC) {
162 SubclassData = (SubclassData & 1) | (static_cast<unsigned>(CC) << 1);
165 /// getAttributes - Return the attribute list for this Function.
167 const AttrListPtr &getAttributes() const { return AttributeList; }
169 /// setAttributes - Set the attribute list for this Function.
171 void setAttributes(const AttrListPtr &attrs) { AttributeList = attrs; }
173 /// hasFnAttr - Return true if this function has the given attribute.
174 bool hasFnAttr(Attributes N) const {
175 // Function Attributes are stored at ~0 index
176 return AttributeList.paramHasAttr(~0U, N);
179 /// addFnAttr - Add function attributes to this function.
181 void addFnAttr(Attributes N) {
182 // Function Attributes are stored at ~0 index
183 addAttribute(~0U, N);
186 /// removeFnAttr - Remove function attributes from this function.
188 void removeFnAttr(Attributes N) {
189 // Function Attributes are stored at ~0 index
190 removeAttribute(~0U, N);
193 /// hasGC/getGC/setGC/clearGC - The name of the garbage collection algorithm
194 /// to use during code generation.
196 const char *getGC() const;
197 void setGC(const char *Str);
200 /// @brief Determine whether the function has the given attribute.
201 bool paramHasAttr(unsigned i, Attributes attr) const {
202 return AttributeList.paramHasAttr(i, attr);
205 /// addAttribute - adds the attribute to the list of attributes.
206 void addAttribute(unsigned i, Attributes attr);
208 /// removeAttribute - removes the attribute from the list of attributes.
209 void removeAttribute(unsigned i, Attributes attr);
211 /// @brief Extract the alignment for a call or parameter (0=unknown).
212 unsigned getParamAlignment(unsigned i) const {
213 return AttributeList.getParamAlignment(i);
216 /// @brief Determine if the function does not access memory.
217 bool doesNotAccessMemory() const {
218 return hasFnAttr(Attribute::ReadNone);
220 void setDoesNotAccessMemory(bool DoesNotAccessMemory = true) {
221 if (DoesNotAccessMemory) addFnAttr(Attribute::ReadNone);
222 else removeFnAttr(Attribute::ReadNone);
225 /// @brief Determine if the function does not access or only reads memory.
226 bool onlyReadsMemory() const {
227 return doesNotAccessMemory() || hasFnAttr(Attribute::ReadOnly);
229 void setOnlyReadsMemory(bool OnlyReadsMemory = true) {
230 if (OnlyReadsMemory) addFnAttr(Attribute::ReadOnly);
231 else removeFnAttr(Attribute::ReadOnly | Attribute::ReadNone);
234 /// @brief Determine if the function cannot return.
235 bool doesNotReturn() const {
236 return hasFnAttr(Attribute::NoReturn);
238 void setDoesNotReturn(bool DoesNotReturn = true) {
239 if (DoesNotReturn) addFnAttr(Attribute::NoReturn);
240 else removeFnAttr(Attribute::NoReturn);
243 /// @brief Determine if the function cannot unwind.
244 bool doesNotThrow() const {
245 return hasFnAttr(Attribute::NoUnwind);
247 void setDoesNotThrow(bool DoesNotThrow = true) {
248 if (DoesNotThrow) addFnAttr(Attribute::NoUnwind);
249 else removeFnAttr(Attribute::NoUnwind);
252 /// @brief Determine if the function returns a structure through first
253 /// pointer argument.
254 bool hasStructRetAttr() const {
255 return paramHasAttr(1, Attribute::StructRet);
258 /// @brief Determine if the parameter does not alias other parameters.
259 /// @param n The parameter to check. 1 is the first parameter, 0 is the return
260 bool doesNotAlias(unsigned n) const {
261 return paramHasAttr(n, Attribute::NoAlias);
263 void setDoesNotAlias(unsigned n, bool DoesNotAlias = true) {
264 if (DoesNotAlias) addAttribute(n, Attribute::NoAlias);
265 else removeAttribute(n, Attribute::NoAlias);
268 /// @brief Determine if the parameter can be captured.
269 /// @param n The parameter to check. 1 is the first parameter, 0 is the return
270 bool doesNotCapture(unsigned n) const {
271 return paramHasAttr(n, Attribute::NoCapture);
273 void setDoesNotCapture(unsigned n, bool DoesNotCapture = true) {
274 if (DoesNotCapture) addAttribute(n, Attribute::NoCapture);
275 else removeAttribute(n, Attribute::NoCapture);
278 /// copyAttributesFrom - copy all additional attributes (those not needed to
279 /// create a Function) from the Function Src to this one.
280 void copyAttributesFrom(const GlobalValue *Src);
282 /// deleteBody - This method deletes the body of the function, and converts
283 /// the linkage to external.
287 setLinkage(ExternalLinkage);
290 /// removeFromParent - This method unlinks 'this' from the containing module,
291 /// but does not delete it.
293 virtual void removeFromParent();
295 /// eraseFromParent - This method unlinks 'this' from the containing module
298 virtual void eraseFromParent();
301 /// Get the underlying elements of the Function... the basic block list is
302 /// empty for external functions.
304 const ArgumentListType &getArgumentList() const {
305 CheckLazyArguments();
308 ArgumentListType &getArgumentList() {
309 CheckLazyArguments();
312 static iplist<Argument> Function::*getSublistAccess(Argument*) {
313 return &Function::ArgumentList;
316 const BasicBlockListType &getBasicBlockList() const { return BasicBlocks; }
317 BasicBlockListType &getBasicBlockList() { return BasicBlocks; }
318 static iplist<BasicBlock> Function::*getSublistAccess(BasicBlock*) {
319 return &Function::BasicBlocks;
322 const BasicBlock &getEntryBlock() const { return front(); }
323 BasicBlock &getEntryBlock() { return front(); }
325 //===--------------------------------------------------------------------===//
326 // Symbol Table Accessing functions...
328 /// getSymbolTable() - Return the symbol table...
330 inline ValueSymbolTable &getValueSymbolTable() { return *SymTab; }
331 inline const ValueSymbolTable &getValueSymbolTable() const { return *SymTab; }
334 //===--------------------------------------------------------------------===//
335 // BasicBlock iterator forwarding functions
337 iterator begin() { return BasicBlocks.begin(); }
338 const_iterator begin() const { return BasicBlocks.begin(); }
339 iterator end () { return BasicBlocks.end(); }
340 const_iterator end () const { return BasicBlocks.end(); }
342 size_t size() const { return BasicBlocks.size(); }
343 bool empty() const { return BasicBlocks.empty(); }
344 const BasicBlock &front() const { return BasicBlocks.front(); }
345 BasicBlock &front() { return BasicBlocks.front(); }
346 const BasicBlock &back() const { return BasicBlocks.back(); }
347 BasicBlock &back() { return BasicBlocks.back(); }
349 //===--------------------------------------------------------------------===//
350 // Argument iterator forwarding functions
352 arg_iterator arg_begin() {
353 CheckLazyArguments();
354 return ArgumentList.begin();
356 const_arg_iterator arg_begin() const {
357 CheckLazyArguments();
358 return ArgumentList.begin();
360 arg_iterator arg_end() {
361 CheckLazyArguments();
362 return ArgumentList.end();
364 const_arg_iterator arg_end() const {
365 CheckLazyArguments();
366 return ArgumentList.end();
369 size_t arg_size() const;
370 bool arg_empty() const;
372 /// viewCFG - This function is meant for use from the debugger. You can just
373 /// say 'call F->viewCFG()' and a ghostview window should pop up from the
374 /// program, displaying the CFG of the current function with the code for each
375 /// basic block inside. This depends on there being a 'dot' and 'gv' program
378 void viewCFG() const;
380 /// viewCFGOnly - This function is meant for use from the debugger. It works
381 /// just like viewCFG, but it does not include the contents of basic blocks
382 /// into the nodes, just the label. If you are only interested in the CFG
383 /// this can make the graph smaller.
385 void viewCFGOnly() const;
387 /// Methods for support type inquiry through isa, cast, and dyn_cast:
388 static inline bool classof(const Function *) { return true; }
389 static inline bool classof(const Value *V) {
390 return V->getValueID() == Value::FunctionVal;
393 /// dropAllReferences() - This method causes all the subinstructions to "let
394 /// go" of all references that they are maintaining. This allows one to
395 /// 'delete' a whole module at a time, even though there may be circular
396 /// references... first all references are dropped, and all use counts go to
397 /// zero. Then everything is deleted for real. Note that no operations are
398 /// valid on an object that has "dropped all references", except operator
401 /// Since no other object in the module can have references into the body of a
402 /// function, dropping all references deletes the entire body of the function,
403 /// including any contained basic blocks.
405 void dropAllReferences();
407 /// hasAddressTaken - returns true if there are any uses of this function
408 /// other than direct calls or invokes to it.
409 bool hasAddressTaken() const;
412 inline ValueSymbolTable *
413 ilist_traits<BasicBlock>::getSymTab(Function *F) {
414 return F ? &F->getValueSymbolTable() : 0;
417 inline ValueSymbolTable *
418 ilist_traits<Argument>::getSymTab(Function *F) {
419 return F ? &F->getValueSymbolTable() : 0;
422 } // End llvm namespace