include/llvm/IR/Argument.h

   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 /// This class represents an incoming formal argument to a Function. A formal
  25 /// argument, since it is ``formal'', does not contain an actual value but
  26 /// instead represents the type, argument number, and attributes of an argument
  27 /// for a specific function. When used in the body of said function, the
  28 /// argument of course represents the value of the actual argument that the
  29 /// function was called with.
  30 class Argument final : public Value {
  31   Function *Parent;
  32   unsigned ArgNo;
  33
  34   friend class Function;
  35   void setParent(Function *parent);
  36
  37 public:
  38   /// Argument constructor.
  39   explicit Argument(Type *Ty, const Twine &Name = "", Function *F = nullptr,
  40                     unsigned ArgNo = 0);
  41
  42   inline const Function *getParent() const { return Parent; }
  43   inline       Function *getParent()       { return Parent; }
  44
  45   /// Return the index of this formal argument in its containing function.
  46   ///
  47   /// For example in "void foo(int a, float b)" a is 0 and b is 1.
  48   unsigned getArgNo() const {
  49     assert(Parent && "can't get number of unparented arg");
  50     return ArgNo;
  51   }
  52
  53   /// Return true if this argument has the nonnull attribute. Also returns true
  54   /// if at least one byte is known to be dereferenceable and the pointer is in
  55   /// addrspace(0).
  56   bool hasNonNullAttr() const;
  57
  58   /// If this argument has the dereferenceable attribute, return the number of
  59   /// bytes known to be dereferenceable. Otherwise, zero is returned.
  60   uint64_t getDereferenceableBytes() const;
  61
  62   /// If this argument has the dereferenceable_or_null attribute, return the
  63   /// number of bytes known to be dereferenceable. Otherwise, zero is returned.
  64   uint64_t getDereferenceableOrNullBytes() const;
  65
  66   /// Return true if this argument has the byval attribute.
  67   bool hasByValAttr() const;
  68
  69   /// Return true if this argument has the swiftself attribute.
  70   bool hasSwiftSelfAttr() const;
  71
  72   /// Return true if this argument has the swifterror attribute.
  73   bool hasSwiftErrorAttr() const;
  74
  75   /// Return true if this argument has the byval attribute or inalloca
  76   /// attribute. These attributes represent arguments being passed by value.
  77   bool hasByValOrInAllocaAttr() const;
  78
  79   /// If this is a byval or inalloca argument, return its alignment.
  80   unsigned getParamAlignment() const;
  81
  82   /// Return true if this argument has the nest attribute.
  83   bool hasNestAttr() const;
  84
  85   /// Return true if this argument has the noalias attribute.
  86   bool hasNoAliasAttr() const;
  87
  88   /// Return true if this argument has the nocapture attribute.
  89   bool hasNoCaptureAttr() const;
  90
  91   /// Return true if this argument has the sret attribute.
  92   bool hasStructRetAttr() const;
  93
  94   /// Return true if this argument has the returned attribute.
  95   bool hasReturnedAttr() const;
  96
  97   /// Return true if this argument has the readonly or readnone attribute.
  98   bool onlyReadsMemory() const;
  99
 100   /// Return true if this argument has the inalloca attribute.
 101   bool hasInAllocaAttr() const;
 102
 103   /// Return true if this argument has the zext attribute.
 104   bool hasZExtAttr() const;
 105
 106   /// Return true if this argument has the sext attribute.
 107   bool hasSExtAttr() const;
 108
 109   /// Add attributes to an argument.
 110   void addAttrs(AttrBuilder &B);
 111
 112   void addAttr(Attribute::AttrKind Kind);
 113
 114   void addAttr(Attribute Attr);
 115
 116   /// Remove attributes from an argument.
 117   void removeAttr(Attribute::AttrKind Kind);
 118
 119   /// Check if an argument has a given attribute.
 120   bool hasAttribute(Attribute::AttrKind Kind) const;
 121
 122   /// Method for support type inquiry through isa, cast, and dyn_cast.
 123   static bool classof(const Value *V) {
 124     return V->getValueID() == ArgumentVal;
 125   }
 126 };
 127
 128 } // End llvm namespace
 129
 130 #endif