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"
27 #include "llvm/ADT/DenseMap.h"
34 // Traits for intrusive list of basic blocks...
35 template<> struct ilist_traits<BasicBlock>
36 : public SymbolTableListTraits<BasicBlock, Function> {
38 // createSentinel is used to get hold of the node that marks the end of the
39 // list... (same trick used here as in ilist_traits<Instruction>)
40 BasicBlock *createSentinel() const {
41 return static_cast<BasicBlock*>(&Sentinel);
43 static void destroySentinel(BasicBlock*) {}
45 BasicBlock *provideInitialHead() const { return createSentinel(); }
46 BasicBlock *ensureHead(BasicBlock*) const { return createSentinel(); }
47 static void noteHead(BasicBlock*, BasicBlock*) {}
49 static ValueSymbolTable *getSymTab(Function *ItemParent);
51 mutable ilist_half_node<BasicBlock> Sentinel;
54 template<> struct ilist_traits<Argument>
55 : public SymbolTableListTraits<Argument, Function> {
57 Argument *createSentinel() const {
58 return static_cast<Argument*>(&Sentinel);
60 static void destroySentinel(Argument*) {}
62 Argument *provideInitialHead() const { return createSentinel(); }
63 Argument *ensureHead(Argument*) const { return createSentinel(); }
64 static void noteHead(Argument*, Argument*) {}
66 static ValueSymbolTable *getSymTab(Function *ItemParent);
68 mutable ilist_half_node<Argument> Sentinel;
71 class Function : public GlobalValue,
72 public ilist_node<Function> {
74 typedef iplist<Argument> ArgumentListType;
75 typedef iplist<BasicBlock> BasicBlockListType;
77 // BasicBlock iterators...
78 typedef BasicBlockListType::iterator iterator;
79 typedef BasicBlockListType::const_iterator const_iterator;
81 typedef ArgumentListType::iterator arg_iterator;
82 typedef ArgumentListType::const_iterator const_arg_iterator;
85 // Important things that make up a function!
86 BasicBlockListType BasicBlocks; ///< The basic blocks
87 mutable ArgumentListType ArgumentList; ///< The formal arguments
88 ValueSymbolTable *SymTab; ///< Symbol table of args/instructions
89 AttrListPtr AttributeList; ///< Parameter attributes
90 DenseMap<Instruction*, unsigned>
91 CallSiteNumbering; ///< SjLj EH call site numbering
93 // HasLazyArguments is stored in Value::SubclassData.
94 /*bool HasLazyArguments;*/
96 // The Calling Convention is stored in Value::SubclassData.
97 /*CallingConv::ID CallingConvention;*/
99 friend class SymbolTableListTraits<Function, Module>;
101 void setParent(Module *parent);
103 /// hasLazyArguments/CheckLazyArguments - The argument list of a function is
104 /// built on demand, so that the list isn't allocated until the first client
105 /// needs it. The hasLazyArguments predicate returns true if the arg list
106 /// hasn't been set up yet.
107 bool hasLazyArguments() const {
108 return getSubclassDataFromValue() & 1;
110 void CheckLazyArguments() const {
111 if (hasLazyArguments())
112 BuildLazyArguments();
114 void BuildLazyArguments() const;
116 Function(const Function&); // DO NOT IMPLEMENT
117 void operator=(const Function&); // DO NOT IMPLEMENT
119 /// Function ctor - If the (optional) Module argument is specified, the
120 /// function is automatically inserted into the end of the function list for
123 Function(const FunctionType *Ty, LinkageTypes Linkage,
124 const Twine &N = "", Module *M = 0);
127 static Function *Create(const FunctionType *Ty, LinkageTypes Linkage,
128 const Twine &N = "", Module *M = 0) {
129 return new(0) Function(Ty, Linkage, N, M);
134 const Type *getReturnType() const; // Return the type of the ret val
135 const FunctionType *getFunctionType() const; // Return the FunctionType for me
137 /// getContext - Return a pointer to the LLVMContext associated with this
138 /// function, or NULL if this function is not bound to a context yet.
139 LLVMContext &getContext() const;
141 /// isVarArg - Return true if this function takes a variable number of
143 bool isVarArg() const;
145 /// isDeclaration - Is the body of this function unknown? (The basic block
146 /// list is empty if so.) This is true for function declarations, but not
147 /// true for function definitions.
149 virtual bool isDeclaration() const { return BasicBlocks.empty(); }
151 /// getIntrinsicID - This method returns the ID number of the specified
152 /// function, or Intrinsic::not_intrinsic if the function is not an
153 /// instrinsic, or if the pointer is null. This value is always defined to be
154 /// zero to allow easy checking for whether a function is intrinsic or not.
155 /// The particular intrinsic functions which correspond to this value are
156 /// defined in llvm/Intrinsics.h.
158 unsigned getIntrinsicID() const ATTRIBUTE_READONLY;
159 bool isIntrinsic() const { return getIntrinsicID() != 0; }
161 /// getCallingConv()/setCallingConv(CC) - These method get and set the
162 /// calling convention of this function. The enum values for the known
163 /// calling conventions are defined in CallingConv.h.
164 CallingConv::ID getCallingConv() const {
165 return static_cast<CallingConv::ID>(getSubclassDataFromValue() >> 1);
167 void setCallingConv(CallingConv::ID CC) {
168 setValueSubclassData((getSubclassDataFromValue() & 1) |
169 (static_cast<unsigned>(CC) << 1));
172 /// setCallSiteNumber - Set the call site number mapping for an invoke
174 void setCallSiteNumber(Instruction *II, unsigned Num) {
175 CallSiteNumbering[II] = Num;
178 /// getCallSiteNumber - Get the call site number for an invoke instruction
179 unsigned getCallSiteNumber(Instruction *II) {
180 if (CallSiteNumbering.count(II) == 0) return 0;
181 return CallSiteNumbering[II];
184 /// getAttributes - Return the attribute list for this Function.
186 const AttrListPtr &getAttributes() const { return AttributeList; }
188 /// setAttributes - Set the attribute list for this Function.
190 void setAttributes(const AttrListPtr &attrs) { AttributeList = attrs; }
192 /// hasFnAttr - Return true if this function has the given attribute.
193 bool hasFnAttr(Attributes N) const {
194 // Function Attributes are stored at ~0 index
195 return AttributeList.paramHasAttr(~0U, N);
198 /// addFnAttr - Add function attributes to this function.
200 void addFnAttr(Attributes N) {
201 // Function Attributes are stored at ~0 index
202 addAttribute(~0U, N);
205 /// removeFnAttr - Remove function attributes from this function.
207 void removeFnAttr(Attributes N) {
208 // Function Attributes are stored at ~0 index
209 removeAttribute(~0U, N);
212 /// hasGC/getGC/setGC/clearGC - The name of the garbage collection algorithm
213 /// to use during code generation.
215 const char *getGC() const;
216 void setGC(const char *Str);
219 /// @brief Determine whether the function has the given attribute.
220 bool paramHasAttr(unsigned i, Attributes attr) const {
221 return AttributeList.paramHasAttr(i, attr);
224 /// addAttribute - adds the attribute to the list of attributes.
225 void addAttribute(unsigned i, Attributes attr);
227 /// removeAttribute - removes the attribute from the list of attributes.
228 void removeAttribute(unsigned i, Attributes attr);
230 /// @brief Extract the alignment for a call or parameter (0=unknown).
231 unsigned getParamAlignment(unsigned i) const {
232 return AttributeList.getParamAlignment(i);
235 /// @brief Determine if the function does not access memory.
236 bool doesNotAccessMemory() const {
237 return hasFnAttr(Attribute::ReadNone);
239 void setDoesNotAccessMemory(bool DoesNotAccessMemory = true) {
240 if (DoesNotAccessMemory) addFnAttr(Attribute::ReadNone);
241 else removeFnAttr(Attribute::ReadNone);
244 /// @brief Determine if the function does not access or only reads memory.
245 bool onlyReadsMemory() const {
246 return doesNotAccessMemory() || hasFnAttr(Attribute::ReadOnly);
248 void setOnlyReadsMemory(bool OnlyReadsMemory = true) {
249 if (OnlyReadsMemory) addFnAttr(Attribute::ReadOnly);
250 else removeFnAttr(Attribute::ReadOnly | Attribute::ReadNone);
253 /// @brief Determine if the function cannot return.
254 bool doesNotReturn() const {
255 return hasFnAttr(Attribute::NoReturn);
257 void setDoesNotReturn(bool DoesNotReturn = true) {
258 if (DoesNotReturn) addFnAttr(Attribute::NoReturn);
259 else removeFnAttr(Attribute::NoReturn);
262 /// @brief Determine if the function cannot unwind.
263 bool doesNotThrow() const {
264 return hasFnAttr(Attribute::NoUnwind);
266 void setDoesNotThrow(bool DoesNotThrow = true) {
267 if (DoesNotThrow) addFnAttr(Attribute::NoUnwind);
268 else removeFnAttr(Attribute::NoUnwind);
271 /// @brief Determine if the function returns a structure through first
272 /// pointer argument.
273 bool hasStructRetAttr() const {
274 return paramHasAttr(1, Attribute::StructRet);
277 /// @brief Determine if the parameter does not alias other parameters.
278 /// @param n The parameter to check. 1 is the first parameter, 0 is the return
279 bool doesNotAlias(unsigned n) const {
280 return paramHasAttr(n, Attribute::NoAlias);
282 void setDoesNotAlias(unsigned n, bool DoesNotAlias = true) {
283 if (DoesNotAlias) addAttribute(n, Attribute::NoAlias);
284 else removeAttribute(n, Attribute::NoAlias);
287 /// @brief Determine if the parameter can be captured.
288 /// @param n The parameter to check. 1 is the first parameter, 0 is the return
289 bool doesNotCapture(unsigned n) const {
290 return paramHasAttr(n, Attribute::NoCapture);
292 void setDoesNotCapture(unsigned n, bool DoesNotCapture = true) {
293 if (DoesNotCapture) addAttribute(n, Attribute::NoCapture);
294 else removeAttribute(n, Attribute::NoCapture);
297 /// copyAttributesFrom - copy all additional attributes (those not needed to
298 /// create a Function) from the Function Src to this one.
299 void copyAttributesFrom(const GlobalValue *Src);
301 /// deleteBody - This method deletes the body of the function, and converts
302 /// the linkage to external.
306 setLinkage(ExternalLinkage);
309 /// removeFromParent - This method unlinks 'this' from the containing module,
310 /// but does not delete it.
312 virtual void removeFromParent();
314 /// eraseFromParent - This method unlinks 'this' from the containing module
317 virtual void eraseFromParent();
320 /// Get the underlying elements of the Function... the basic block list is
321 /// empty for external functions.
323 const ArgumentListType &getArgumentList() const {
324 CheckLazyArguments();
327 ArgumentListType &getArgumentList() {
328 CheckLazyArguments();
331 static iplist<Argument> Function::*getSublistAccess(Argument*) {
332 return &Function::ArgumentList;
335 const BasicBlockListType &getBasicBlockList() const { return BasicBlocks; }
336 BasicBlockListType &getBasicBlockList() { return BasicBlocks; }
337 static iplist<BasicBlock> Function::*getSublistAccess(BasicBlock*) {
338 return &Function::BasicBlocks;
341 const BasicBlock &getEntryBlock() const { return front(); }
342 BasicBlock &getEntryBlock() { return front(); }
344 //===--------------------------------------------------------------------===//
345 // Symbol Table Accessing functions...
347 /// getSymbolTable() - Return the symbol table...
349 inline ValueSymbolTable &getValueSymbolTable() { return *SymTab; }
350 inline const ValueSymbolTable &getValueSymbolTable() const { return *SymTab; }
353 //===--------------------------------------------------------------------===//
354 // BasicBlock iterator forwarding functions
356 iterator begin() { return BasicBlocks.begin(); }
357 const_iterator begin() const { return BasicBlocks.begin(); }
358 iterator end () { return BasicBlocks.end(); }
359 const_iterator end () const { return BasicBlocks.end(); }
361 size_t size() const { return BasicBlocks.size(); }
362 bool empty() const { return BasicBlocks.empty(); }
363 const BasicBlock &front() const { return BasicBlocks.front(); }
364 BasicBlock &front() { return BasicBlocks.front(); }
365 const BasicBlock &back() const { return BasicBlocks.back(); }
366 BasicBlock &back() { return BasicBlocks.back(); }
368 //===--------------------------------------------------------------------===//
369 // Argument iterator forwarding functions
371 arg_iterator arg_begin() {
372 CheckLazyArguments();
373 return ArgumentList.begin();
375 const_arg_iterator arg_begin() const {
376 CheckLazyArguments();
377 return ArgumentList.begin();
379 arg_iterator arg_end() {
380 CheckLazyArguments();
381 return ArgumentList.end();
383 const_arg_iterator arg_end() const {
384 CheckLazyArguments();
385 return ArgumentList.end();
388 size_t arg_size() const;
389 bool arg_empty() const;
391 /// viewCFG - This function is meant for use from the debugger. You can just
392 /// say 'call F->viewCFG()' and a ghostview window should pop up from the
393 /// program, displaying the CFG of the current function with the code for each
394 /// basic block inside. This depends on there being a 'dot' and 'gv' program
397 void viewCFG() const;
399 /// viewCFGOnly - This function is meant for use from the debugger. It works
400 /// just like viewCFG, but it does not include the contents of basic blocks
401 /// into the nodes, just the label. If you are only interested in the CFG
402 /// this can make the graph smaller.
404 void viewCFGOnly() const;
406 /// Methods for support type inquiry through isa, cast, and dyn_cast:
407 static inline bool classof(const Function *) { return true; }
408 static inline bool classof(const Value *V) {
409 return V->getValueID() == Value::FunctionVal;
412 /// dropAllReferences() - This method causes all the subinstructions to "let
413 /// go" of all references that they are maintaining. This allows one to
414 /// 'delete' a whole module at a time, even though there may be circular
415 /// references... first all references are dropped, and all use counts go to
416 /// zero. Then everything is deleted for real. Note that no operations are
417 /// valid on an object that has "dropped all references", except operator
420 /// Since no other object in the module can have references into the body of a
421 /// function, dropping all references deletes the entire body of the function,
422 /// including any contained basic blocks.
424 void dropAllReferences();
426 /// hasAddressTaken - returns true if there are any uses of this function
427 /// other than direct calls or invokes to it.
428 bool hasAddressTaken() const;
430 // Shadow Value::setValueSubclassData with a private forwarding method so that
431 // subclasses cannot accidentally use it.
432 void setValueSubclassData(unsigned short D) {
433 Value::setValueSubclassData(D);
437 inline ValueSymbolTable *
438 ilist_traits<BasicBlock>::getSymTab(Function *F) {
439 return F ? &F->getValueSymbolTable() : 0;
442 inline ValueSymbolTable *
443 ilist_traits<Argument>::getSymTab(Function *F) {
444 return F ? &F->getValueSymbolTable() : 0;
447 } // End llvm namespace