//===-- llvm/Function.h - Class to represent a single function --*- C++ -*-===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file contains the declaration of the Function class, which represents a // single function/procedure in LLVM. // // A function basically consists of a list of basic blocks, a list of arguments, // and a symbol table. // //===----------------------------------------------------------------------===// #ifndef LLVM_FUNCTION_H #define LLVM_FUNCTION_H #include "llvm/GlobalValue.h" #include "llvm/CallingConv.h" #include "llvm/BasicBlock.h" #include "llvm/Argument.h" #include "llvm/Attributes.h" #include "llvm/Support/Compiler.h" namespace llvm { class FunctionType; class LLVMContext; // Traits for intrusive list of basic blocks... template<> struct ilist_traits<BasicBlock> : public SymbolTableListTraits<BasicBlock, Function> { // createSentinel is used to get hold of the node that marks the end of the // list... (same trick used here as in ilist_traits<Instruction>) BasicBlock *createSentinel() const { return static_cast<BasicBlock*>(&Sentinel); } static void destroySentinel(BasicBlock*) {} BasicBlock *provideInitialHead() const { return createSentinel(); } BasicBlock *ensureHead(BasicBlock*) const { return createSentinel(); } static void noteHead(BasicBlock*, BasicBlock*) {} static ValueSymbolTable *getSymTab(Function *ItemParent); private: mutable ilist_half_node<BasicBlock> Sentinel; }; template<> struct ilist_traits<Argument> : public SymbolTableListTraits<Argument, Function> { Argument *createSentinel() const { return static_cast<Argument*>(&Sentinel); } static void destroySentinel(Argument*) {} Argument *provideInitialHead() const { return createSentinel(); } Argument *ensureHead(Argument*) const { return createSentinel(); } static void noteHead(Argument*, Argument*) {} static ValueSymbolTable *getSymTab(Function *ItemParent); private: mutable ilist_half_node<Argument> Sentinel; }; class Function : public GlobalValue, public ilist_node<Function> { public: typedef iplist<Argument> ArgumentListType; typedef iplist<BasicBlock> BasicBlockListType; // BasicBlock iterators... typedef BasicBlockListType::iterator iterator; typedef BasicBlockListType::const_iterator const_iterator; typedef ArgumentListType::iterator arg_iterator; typedef ArgumentListType::const_iterator const_arg_iterator; private: // Important things that make up a function! BasicBlockListType BasicBlocks; ///< The basic blocks mutable ArgumentListType ArgumentList; ///< The formal arguments ValueSymbolTable *SymTab; ///< Symbol table of args/instructions AttrListPtr AttributeList; ///< Parameter attributes // HasLazyArguments is stored in Value::SubclassData. /*bool HasLazyArguments;*/ // The Calling Convention is stored in Value::SubclassData. /*CallingConv::ID CallingConvention;*/ friend class SymbolTableListTraits<Function, Module>; void setParent(Module *parent); /// hasLazyArguments/CheckLazyArguments - The argument list of a function is /// built on demand, so that the list isn't allocated until the first client /// needs it. The hasLazyArguments predicate returns true if the arg list /// hasn't been set up yet. bool hasLazyArguments() const { return getSubclassDataFromValue() & 1; } void CheckLazyArguments() const { if (hasLazyArguments()) BuildLazyArguments(); } void BuildLazyArguments() const; Function(const Function&); // DO NOT IMPLEMENT void operator=(const Function&); // DO NOT IMPLEMENT /// Function ctor - If the (optional) Module argument is specified, the /// function is automatically inserted into the end of the function list for /// the module. /// Function(const FunctionType *Ty, LinkageTypes Linkage, const Twine &N = "", Module *M = 0); public: static Function *Create(const FunctionType *Ty, LinkageTypes Linkage, const Twine &N = "", Module *M = 0) { return new(0) Function(Ty, Linkage, N, M); } ~Function(); const Type *getReturnType() const; // Return the type of the ret val const FunctionType *getFunctionType() const; // Return the FunctionType for me /// getContext - Return a pointer to the LLVMContext associated with this /// function, or NULL if this function is not bound to a context yet. LLVMContext &getContext() const; /// isVarArg - Return true if this function takes a variable number of /// arguments. bool isVarArg() const; /// isDeclaration - Is the body of this function unknown? (The basic block /// list is empty if so.) This is true for function declarations, but not /// true for function definitions. /// virtual bool isDeclaration() const { return BasicBlocks.empty(); } /// getIntrinsicID - This method returns the ID number of the specified /// function, or Intrinsic::not_intrinsic if the function is not an /// instrinsic, or if the pointer is null. This value is always defined to be /// zero to allow easy checking for whether a function is intrinsic or not. /// The particular intrinsic functions which correspond to this value are /// defined in llvm/Intrinsics.h. /// unsigned getIntrinsicID() const ATTRIBUTE_READONLY; bool isIntrinsic() const { return getIntrinsicID() != 0; } /// getCallingConv()/setCallingConv(CC) - These method get and set the /// calling convention of this function. The enum values for the known /// calling conventions are defined in CallingConv.h. CallingConv::ID getCallingConv() const { return static_cast<CallingConv::ID>(getSubclassDataFromValue() >> 1); } void setCallingConv(CallingConv::ID CC) { setValueSubclassData((getSubclassDataFromValue() & 1) | (static_cast<unsigned>(CC) << 1)); } /// getAttributes - Return the attribute list for this Function. /// const AttrListPtr &getAttributes() const { return AttributeList; } /// setAttributes - Set the attribute list for this Function. /// void setAttributes(const AttrListPtr &attrs) { AttributeList = attrs; } /// hasFnAttr - Return true if this function has the given attribute. bool hasFnAttr(Attributes N) const { // Function Attributes are stored at ~0 index return AttributeList.paramHasAttr(~0U, N); } /// addFnAttr - Add function attributes to this function. /// void addFnAttr(Attributes N) { // Function Attributes are stored at ~0 index addAttribute(~0U, N); } /// removeFnAttr - Remove function attributes from this function. /// void removeFnAttr(Attributes N) { // Function Attributes are stored at ~0 index removeAttribute(~0U, N); } /// hasGC/getGC/setGC/clearGC - The name of the garbage collection algorithm /// to use during code generation. bool hasGC() const; const char *getGC() const; void setGC(const char *Str); void clearGC(); /// @brief Determine whether the function has the given attribute. bool paramHasAttr(unsigned i, Attributes attr) const { return AttributeList.paramHasAttr(i, attr); } /// addAttribute - adds the attribute to the list of attributes. void addAttribute(unsigned i, Attributes attr); /// removeAttribute - removes the attribute from the list of attributes. void removeAttribute(unsigned i, Attributes attr); /// @brief Extract the alignment for a call or parameter (0=unknown). unsigned getParamAlignment(unsigned i) const { return AttributeList.getParamAlignment(i); } /// @brief Determine if the function does not access memory. bool doesNotAccessMemory() const { return hasFnAttr(Attribute::ReadNone); } void setDoesNotAccessMemory(bool DoesNotAccessMemory = true) { if (DoesNotAccessMemory) addFnAttr(Attribute::ReadNone); else removeFnAttr(Attribute::ReadNone); } /// @brief Determine if the function does not access or only reads memory. bool onlyReadsMemory() const { return doesNotAccessMemory() || hasFnAttr(Attribute::ReadOnly); } void setOnlyReadsMemory(bool OnlyReadsMemory = true) { if (OnlyReadsMemory) addFnAttr(Attribute::ReadOnly); else removeFnAttr(Attribute::ReadOnly | Attribute::ReadNone); } /// @brief Determine if the function cannot return. bool doesNotReturn() const { return hasFnAttr(Attribute::NoReturn); } void setDoesNotReturn(bool DoesNotReturn = true) { if (DoesNotReturn) addFnAttr(Attribute::NoReturn); else removeFnAttr(Attribute::NoReturn); } /// @brief Determine if the function cannot unwind. bool doesNotThrow() const { return hasFnAttr(Attribute::NoUnwind); } void setDoesNotThrow(bool DoesNotThrow = true) { if (DoesNotThrow) addFnAttr(Attribute::NoUnwind); else removeFnAttr(Attribute::NoUnwind); } /// @brief Determine if the function returns a structure through first /// pointer argument. bool hasStructRetAttr() const { return paramHasAttr(1, Attribute::StructRet); } /// @brief Determine if the parameter does not alias other parameters. /// @param n The parameter to check. 1 is the first parameter, 0 is the return bool doesNotAlias(unsigned n) const { return paramHasAttr(n, Attribute::NoAlias); } void setDoesNotAlias(unsigned n, bool DoesNotAlias = true) { if (DoesNotAlias) addAttribute(n, Attribute::NoAlias); else removeAttribute(n, Attribute::NoAlias); } /// @brief Determine if the parameter can be captured. /// @param n The parameter to check. 1 is the first parameter, 0 is the return bool doesNotCapture(unsigned n) const { return paramHasAttr(n, Attribute::NoCapture); } void setDoesNotCapture(unsigned n, bool DoesNotCapture = true) { if (DoesNotCapture) addAttribute(n, Attribute::NoCapture); else removeAttribute(n, Attribute::NoCapture); } /// copyAttributesFrom - copy all additional attributes (those not needed to /// create a Function) from the Function Src to this one. void copyAttributesFrom(const GlobalValue *Src); /// deleteBody - This method deletes the body of the function, and converts /// the linkage to external. /// void deleteBody() { dropAllReferences(); setLinkage(ExternalLinkage); } /// removeFromParent - This method unlinks 'this' from the containing module, /// but does not delete it. /// virtual void removeFromParent(); /// eraseFromParent - This method unlinks 'this' from the containing module /// and deletes it. /// virtual void eraseFromParent(); /// Get the underlying elements of the Function... the basic block list is /// empty for external functions. /// const ArgumentListType &getArgumentList() const { CheckLazyArguments(); return ArgumentList; } ArgumentListType &getArgumentList() { CheckLazyArguments(); return ArgumentList; } static iplist<Argument> Function::*getSublistAccess(Argument*) { return &Function::ArgumentList; } const BasicBlockListType &getBasicBlockList() const { return BasicBlocks; } BasicBlockListType &getBasicBlockList() { return BasicBlocks; } static iplist<BasicBlock> Function::*getSublistAccess(BasicBlock*) { return &Function::BasicBlocks; } const BasicBlock &getEntryBlock() const { return front(); } BasicBlock &getEntryBlock() { return front(); } //===--------------------------------------------------------------------===// // Symbol Table Accessing functions... /// getSymbolTable() - Return the symbol table... /// inline ValueSymbolTable &getValueSymbolTable() { return *SymTab; } inline const ValueSymbolTable &getValueSymbolTable() const { return *SymTab; } //===--------------------------------------------------------------------===// // BasicBlock iterator forwarding functions // iterator begin() { return BasicBlocks.begin(); } const_iterator begin() const { return BasicBlocks.begin(); } iterator end () { return BasicBlocks.end(); } const_iterator end () const { return BasicBlocks.end(); } size_t size() const { return BasicBlocks.size(); } bool empty() const { return BasicBlocks.empty(); } const BasicBlock &front() const { return BasicBlocks.front(); } BasicBlock &front() { return BasicBlocks.front(); } const BasicBlock &back() const { return BasicBlocks.back(); } BasicBlock &back() { return BasicBlocks.back(); } //===--------------------------------------------------------------------===// // Argument iterator forwarding functions // arg_iterator arg_begin() { CheckLazyArguments(); return ArgumentList.begin(); } const_arg_iterator arg_begin() const { CheckLazyArguments(); return ArgumentList.begin(); } arg_iterator arg_end() { CheckLazyArguments(); return ArgumentList.end(); } const_arg_iterator arg_end() const { CheckLazyArguments(); return ArgumentList.end(); } size_t arg_size() const; bool arg_empty() const; /// viewCFG - This function is meant for use from the debugger. You can just /// say 'call F->viewCFG()' and a ghostview window should pop up from the /// program, displaying the CFG of the current function with the code for each /// basic block inside. This depends on there being a 'dot' and 'gv' program /// in your path. /// void viewCFG() const; /// viewCFGOnly - This function is meant for use from the debugger. It works /// just like viewCFG, but it does not include the contents of basic blocks /// into the nodes, just the label. If you are only interested in the CFG /// this can make the graph smaller. /// void viewCFGOnly() const; /// Methods for support type inquiry through isa, cast, and dyn_cast: static inline bool classof(const Function *) { return true; } static inline bool classof(const Value *V) { return V->getValueID() == Value::FunctionVal; } /// dropAllReferences() - This method causes all the subinstructions to "let /// go" of all references that they are maintaining. This allows one to /// 'delete' a whole module at a time, even though there may be circular /// references... first all references are dropped, and all use counts go to /// zero. Then everything is deleted for real. Note that no operations are /// valid on an object that has "dropped all references", except operator /// delete. /// /// Since no other object in the module can have references into the body of a /// function, dropping all references deletes the entire body of the function, /// including any contained basic blocks. /// void dropAllReferences(); /// hasAddressTaken - returns true if there are any uses of this function /// other than direct calls or invokes to it. Optionally passes back the /// offending user for diagnostic purposes. /// bool hasAddressTaken(const User** = 0) const; private: // Shadow Value::setValueSubclassData with a private forwarding method so that // subclasses cannot accidentally use it. void setValueSubclassData(unsigned short D) { Value::setValueSubclassData(D); } }; inline ValueSymbolTable * ilist_traits<BasicBlock>::getSymTab(Function *F) { return F ? &F->getValueSymbolTable() : 0; } inline ValueSymbolTable * ilist_traits<Argument>::getSymTab(Function *F) { return F ? &F->getValueSymbolTable() : 0; } } // End llvm namespace #endif