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      1 //===-- llvm/Argument.h - Definition of the Argument class ------*- C++ -*-===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file declares the Argument class.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #ifndef LLVM_IR_ARGUMENT_H
     15 #define LLVM_IR_ARGUMENT_H
     16 
     17 #include "llvm/ADT/Twine.h"
     18 #include "llvm/ADT/ilist_node.h"
     19 #include "llvm/IR/Attributes.h"
     20 #include "llvm/IR/Value.h"
     21 
     22 namespace llvm {
     23 
     24 template<typename ValueSubClass, typename ItemParentClass>
     25   class SymbolTableListTraits;
     26 
     27 /// \brief LLVM Argument representation
     28 ///
     29 /// This class represents an incoming formal argument to a Function. A formal
     30 /// argument, since it is ``formal'', does not contain an actual value but
     31 /// instead represents the type, argument number, and attributes of an argument
     32 /// for a specific function. When used in the body of said function, the
     33 /// argument of course represents the value of the actual argument that the
     34 /// function was called with.
     35 class Argument : public Value, public ilist_node<Argument> {
     36   virtual void anchor();
     37   Function *Parent;
     38 
     39   friend class SymbolTableListTraits<Argument, Function>;
     40   void setParent(Function *parent);
     41 
     42 public:
     43   /// \brief Constructor.
     44   ///
     45   /// If \p F is specified, the argument is inserted at the end of the argument
     46   /// list for \p F.
     47   explicit Argument(Type *Ty, const Twine &Name = "", Function *F = nullptr);
     48 
     49   inline const Function *getParent() const { return Parent; }
     50   inline       Function *getParent()       { return Parent; }
     51 
     52   /// \brief Return the index of this formal argument in its containing
     53   /// function.
     54   ///
     55   /// For example in "void foo(int a, float b)" a is 0 and b is 1.
     56   unsigned getArgNo() const;
     57 
     58   /// \brief Return true if this argument has the nonnull attribute on it in
     59   /// its containing function.
     60   bool hasNonNullAttr() const;
     61 
     62   /// \brief Return true if this argument has the byval attribute on it in its
     63   /// containing function.
     64   bool hasByValAttr() const;
     65 
     66   /// \brief Return true if this argument has the byval attribute or inalloca
     67   /// attribute on it in its containing function.  These attributes both
     68   /// represent arguments being passed by value.
     69   bool hasByValOrInAllocaAttr() const;
     70 
     71   /// \brief If this is a byval or inalloca argument, return its alignment.
     72   unsigned getParamAlignment() const;
     73 
     74   /// \brief Return true if this argument has the nest attribute on it in its
     75   /// containing function.
     76   bool hasNestAttr() const;
     77 
     78   /// \brief Return true if this argument has the noalias attribute on it in its
     79   /// containing function.
     80   bool hasNoAliasAttr() const;
     81 
     82   /// \brief Return true if this argument has the nocapture attribute on it in
     83   /// its containing function.
     84   bool hasNoCaptureAttr() const;
     85 
     86   /// \brief Return true if this argument has the sret attribute on it in its
     87   /// containing function.
     88   bool hasStructRetAttr() const;
     89 
     90   /// \brief Return true if this argument has the returned attribute on it in
     91   /// its containing function.
     92   bool hasReturnedAttr() const;
     93 
     94   /// \brief Return true if this argument has the readonly or readnone attribute
     95   /// on it in its containing function.
     96   bool onlyReadsMemory() const;
     97 
     98   /// \brief Return true if this argument has the inalloca attribute on it in
     99   /// its containing function.
    100   bool hasInAllocaAttr() const;
    101 
    102   /// \brief Add a Attribute to an argument.
    103   void addAttr(AttributeSet AS);
    104 
    105   /// \brief Remove a Attribute from an argument.
    106   void removeAttr(AttributeSet AS);
    107 
    108   /// \brief Method for support type inquiry through isa, cast, and
    109   /// dyn_cast.
    110   static inline bool classof(const Value *V) {
    111     return V->getValueID() == ArgumentVal;
    112   }
    113 };
    114 
    115 } // End llvm namespace
    116 
    117 #endif
    118