LLVM API Documentation

Function.h

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00001 //===-- llvm/Function.h - Class to represent a single function --*- C++ -*-===//
00002 //
00003 //                     The LLVM Compiler Infrastructure
00004 //
00005 // This file was developed by the LLVM research group and is distributed under
00006 // the University of Illinois Open Source License. See LICENSE.TXT for details.
00007 //
00008 //===----------------------------------------------------------------------===//
00009 //
00010 // This file contains the declaration of the Function class, which represents a
00011 // single function/procedure in LLVM.
00012 //
00013 // A function basically consists of a list of basic blocks, a list of arguments,
00014 // and a symbol table.
00015 //
00016 //===----------------------------------------------------------------------===//
00017 
00018 #ifndef LLVM_FUNCTION_H
00019 #define LLVM_FUNCTION_H
00020 
00021 #include "llvm/GlobalValue.h"
00022 #include "llvm/BasicBlock.h"
00023 #include "llvm/Argument.h"
00024 #include "llvm/Support/Annotation.h"
00025 
00026 namespace llvm {
00027 
00028 class FunctionType;
00029 
00030 // Traits for intrusive list of instructions...
00031 template<> struct ilist_traits<BasicBlock>
00032   : public SymbolTableListTraits<BasicBlock, Function, Function> {
00033 
00034   // createSentinel is used to create a node that marks the end of the list...
00035   static BasicBlock *createSentinel();
00036   static void destroySentinel(BasicBlock *BB) { delete BB; }
00037   static iplist<BasicBlock> &getList(Function *F);
00038 };
00039 
00040 template<> struct ilist_traits<Argument>
00041   : public SymbolTableListTraits<Argument, Function, Function> {
00042 
00043   // createSentinel is used to create a node that marks the end of the list...
00044   static Argument *createSentinel();
00045   static void destroySentinel(Argument *A) { delete A; }
00046   static iplist<Argument> &getList(Function *F);
00047 };
00048 
00049 class Function : public GlobalValue, public Annotable {
00050 public:
00051   typedef iplist<Argument> ArgumentListType;
00052   typedef iplist<BasicBlock> BasicBlockListType;
00053 
00054   // BasicBlock iterators...
00055   typedef BasicBlockListType::iterator iterator;
00056   typedef BasicBlockListType::const_iterator const_iterator;
00057 
00058   typedef ArgumentListType::iterator arg_iterator;
00059   typedef ArgumentListType::const_iterator const_arg_iterator;
00060 
00061 private:
00062   // Important things that make up a function!
00063   BasicBlockListType  BasicBlocks;      // The basic blocks
00064   ArgumentListType ArgumentList;        // The formal arguments
00065 
00066   SymbolTable *SymTab;
00067   unsigned CallingConvention;
00068 
00069   friend class SymbolTableListTraits<Function, Module, Module>;
00070 
00071   void setParent(Module *parent);
00072   Function *Prev, *Next;
00073   void setNext(Function *N) { Next = N; }
00074   void setPrev(Function *N) { Prev = N; }
00075 
00076 public:
00077   /// Function ctor - If the (optional) Module argument is specified, the
00078   /// function is automatically inserted into the end of the function list for
00079   /// the module.
00080   ///
00081   Function(const FunctionType *Ty, LinkageTypes Linkage,
00082            const std::string &N = "", Module *M = 0);
00083   ~Function();
00084 
00085   const Type *getReturnType() const;           // Return the type of the ret val
00086   const FunctionType *getFunctionType() const; // Return the FunctionType for me
00087 
00088   /// isVarArg - Return true if this function takes a variable number of
00089   /// arguments.
00090   bool isVarArg() const;
00091 
00092   /// isExternal - Is the body of this function unknown? (The basic block list
00093   /// is empty if so.) This is true for external functions, defined as forward
00094   /// "declare"ations
00095   ///
00096   virtual bool isExternal() const { return BasicBlocks.empty(); }
00097 
00098   /// getIntrinsicID - This method returns the ID number of the specified
00099   /// function, or Intrinsic::not_intrinsic if the function is not an
00100   /// instrinsic, or if the pointer is null.  This value is always defined to be
00101   /// zero to allow easy checking for whether a function is intrinsic or not.
00102   /// The particular intrinsic functions which correspond to this value are
00103   /// defined in llvm/Intrinsics.h.
00104   ///
00105   unsigned getIntrinsicID() const;
00106   bool isIntrinsic() const { return getIntrinsicID() != 0; }
00107 
00108   /// getCallingConv()/setCallingConv(uint) - These method get and set the
00109   /// calling convention of this function.  The enum values for the known
00110   /// calling conventions are defined in CallingConv.h.
00111   unsigned getCallingConv() const { return CallingConvention; }
00112   void setCallingConv(unsigned CC) { CallingConvention = CC; }
00113 
00114   /// renameLocalSymbols - This method goes through the Function's symbol table
00115   /// and renames any symbols that conflict with symbols at global scope.  This
00116   /// is required before printing out to a textual form, to ensure that there is
00117   /// no ambiguity when parsing.
00118   void renameLocalSymbols();
00119 
00120 
00121   /// deleteBody - This method deletes the body of the function, and converts
00122   /// the linkage to external.
00123   ///
00124   void deleteBody() {
00125     dropAllReferences();
00126     setLinkage(ExternalLinkage);
00127   }
00128 
00129   /// removeFromParent - This method unlinks 'this' from the containing module,
00130   /// but does not delete it.
00131   ///
00132   void removeFromParent();
00133 
00134   /// eraseFromParent - This method unlinks 'this' from the containing module
00135   /// and deletes it.
00136   ///
00137   void eraseFromParent();
00138 
00139 
00140   // getNext/Prev - Return the next or previous function in the list.  These
00141   // methods should never be used directly, and are only used to implement the
00142   // function list as part of the module.
00143   //
00144         Function *getNext()       { return Next; }
00145   const Function *getNext() const { return Next; }
00146         Function *getPrev()       { return Prev; }
00147   const Function *getPrev() const { return Prev; }
00148 
00149   /// Get the underlying elements of the Function... the basic block list is
00150   /// empty for external functions.
00151   ///
00152   const ArgumentListType &getArgumentList() const { return ArgumentList; }
00153         ArgumentListType &getArgumentList()       { return ArgumentList; }
00154 
00155   const BasicBlockListType &getBasicBlockList() const { return BasicBlocks; }
00156         BasicBlockListType &getBasicBlockList()       { return BasicBlocks; }
00157 
00158   const BasicBlock       &getEntryBlock() const   { return front(); }
00159         BasicBlock       &getEntryBlock()         { return front(); }
00160 
00161   //===--------------------------------------------------------------------===//
00162   // Symbol Table Accessing functions...
00163 
00164   /// getSymbolTable() - Return the symbol table...
00165   ///
00166   inline       SymbolTable &getSymbolTable()       { return *SymTab; }
00167   inline const SymbolTable &getSymbolTable() const { return *SymTab; }
00168 
00169 
00170   //===--------------------------------------------------------------------===//
00171   // BasicBlock iterator forwarding functions
00172   //
00173   iterator                begin()       { return BasicBlocks.begin(); }
00174   const_iterator          begin() const { return BasicBlocks.begin(); }
00175   iterator                end  ()       { return BasicBlocks.end();   }
00176   const_iterator          end  () const { return BasicBlocks.end();   }
00177 
00178   size_t                   size() const { return BasicBlocks.size();  }
00179   bool                    empty() const { return BasicBlocks.empty(); }
00180   const BasicBlock       &front() const { return BasicBlocks.front(); }
00181         BasicBlock       &front()       { return BasicBlocks.front(); }
00182   const BasicBlock        &back() const { return BasicBlocks.back();  }
00183         BasicBlock        &back()       { return BasicBlocks.back();  }
00184 
00185   //===--------------------------------------------------------------------===//
00186   // Argument iterator forwarding functions
00187   //
00188   arg_iterator                arg_begin()       { return ArgumentList.begin(); }
00189   const_arg_iterator          arg_begin() const { return ArgumentList.begin(); }
00190   arg_iterator                arg_end  ()       { return ArgumentList.end();   }
00191   const_arg_iterator          arg_end  () const { return ArgumentList.end();   }
00192 
00193   size_t                      arg_size () const { return ArgumentList.size();  }
00194   bool                        arg_empty() const { return ArgumentList.empty(); }
00195 
00196   virtual void print(std::ostream &OS) const { print(OS, 0); }
00197   void print(std::ostream &OS, AssemblyAnnotationWriter *AAW) const;
00198 
00199   /// viewCFG - This function is meant for use from the debugger.  You can just
00200   /// say 'call F->viewCFG()' and a ghostview window should pop up from the
00201   /// program, displaying the CFG of the current function with the code for each
00202   /// basic block inside.  This depends on there being a 'dot' and 'gv' program
00203   /// in your path.
00204   ///
00205   void viewCFG() const;
00206 
00207   /// viewCFGOnly - This function is meant for use from the debugger.  It works
00208   /// just like viewCFG, but it does not include the contents of basic blocks
00209   /// into the nodes, just the label.  If you are only interested in the CFG
00210   /// this can make the graph smaller.
00211   ///
00212   void viewCFGOnly() const;
00213 
00214   /// Methods for support type inquiry through isa, cast, and dyn_cast:
00215   static inline bool classof(const Function *) { return true; }
00216   static inline bool classof(const Value *V) {
00217     return V->getValueType() == Value::FunctionVal;
00218   }
00219 
00220   /// dropAllReferences() - This method causes all the subinstructions to "let
00221   /// go" of all references that they are maintaining.  This allows one to
00222   /// 'delete' a whole module at a time, even though there may be circular
00223   /// references... first all references are dropped, and all use counts go to
00224   /// zero.  Then everything is deleted for real.  Note that no operations are
00225   /// valid on an object that has "dropped all references", except operator
00226   /// delete.
00227   ///
00228   /// Since no other object in the module can have references into the body of a
00229   /// function, dropping all references deletes the entire body of the function,
00230   /// including any contained basic blocks.
00231   ///
00232   void dropAllReferences();
00233 };
00234 
00235 } // End llvm namespace
00236 
00237 #endif