include/llvm/IR/Argument.h

   1 //===-- llvm/Argument.h - Definition of the Argument class ------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file declares the Argument class.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #ifndef LLVM_IR_ARGUMENT_H
  14 #define LLVM_IR_ARGUMENT_H
  15
  16 #include "llvm/ADT/Twine.h"
  17 #include "llvm/ADT/ilist_node.h"
  18 #include "llvm/IR/Attributes.h"
  19 #include "llvm/IR/Value.h"
  20
  21 namespace llvm {
  22
  23 /// This class represents an incoming formal argument to a Function. A formal
  24 /// argument, since it is ``formal'', does not contain an actual value but
  25 /// instead represents the type, argument number, and attributes of an argument
  26 /// for a specific function. When used in the body of said function, the
  27 /// argument of course represents the value of the actual argument that the
  28 /// function was called with.
  29 class Argument final : public Value {
  30   Function *Parent;
  31   unsigned ArgNo;
  32
  33   friend class Function;
  34   void setParent(Function *parent);
  35
  36 public:
  37   /// Argument constructor.
  38   explicit Argument(Type *Ty, const Twine &Name = "", Function *F = nullptr,
  39                     unsigned ArgNo = 0);
  40
  41   inline const Function *getParent() const { return Parent; }
  42   inline       Function *getParent()       { return Parent; }
  43
  44   /// Return the index of this formal argument in its containing function.
  45   ///
  46   /// For example in "void foo(int a, float b)" a is 0 and b is 1.
  47   unsigned getArgNo() const {
  48     assert(Parent && "can't get number of unparented arg");
  49     return ArgNo;
  50   }
  51
  52   /// Return true if this argument has the nonnull attribute. Also returns true
  53   /// if at least one byte is known to be dereferenceable and the pointer is in
  54   /// addrspace(0).
  55   bool hasNonNullAttr() const;
  56
  57   /// If this argument has the dereferenceable attribute, return the number of
  58   /// bytes known to be dereferenceable. Otherwise, zero is returned.
  59   uint64_t getDereferenceableBytes() const;
  60
  61   /// If this argument has the dereferenceable_or_null attribute, return the
  62   /// number of bytes known to be dereferenceable. Otherwise, zero is returned.
  63   uint64_t getDereferenceableOrNullBytes() const;
  64
  65   /// Return true if this argument has the byval attribute.
  66   bool hasByValAttr() const;
  67
  68   /// Return true if this argument has the swiftself attribute.
  69   bool hasSwiftSelfAttr() const;
  70
  71   /// Return true if this argument has the swifterror attribute.
  72   bool hasSwiftErrorAttr() const;
  73
  74   /// Return true if this argument has the byval attribute or inalloca
  75   /// attribute. These attributes represent arguments being passed by value.
  76   bool hasByValOrInAllocaAttr() const;
  77
  78   /// If this is a byval or inalloca argument, return its alignment.
  79   unsigned getParamAlignment() const;
  80
  81   /// If this is a byval argument, return its type.
  82   Type *getParamByValType() const;
  83
  84   /// Return true if this argument has the nest attribute.
  85   bool hasNestAttr() const;
  86
  87   /// Return true if this argument has the noalias attribute.
  88   bool hasNoAliasAttr() const;
  89
  90   /// Return true if this argument has the nocapture attribute.
  91   bool hasNoCaptureAttr() const;
  92
  93   /// Return true if this argument has the sret attribute.
  94   bool hasStructRetAttr() const;
  95
  96   /// Return true if this argument has the inreg attribute.
  97   bool hasInRegAttr() const;
  98
  99   /// Return true if this argument has the returned attribute.
 100   bool hasReturnedAttr() const;
 101
 102   /// Return true if this argument has the readonly or readnone attribute.
 103   bool onlyReadsMemory() const;
 104
 105   /// Return true if this argument has the inalloca attribute.
 106   bool hasInAllocaAttr() const;
 107
 108   /// Return true if this argument has the zext attribute.
 109   bool hasZExtAttr() const;
 110
 111   /// Return true if this argument has the sext attribute.
 112   bool hasSExtAttr() const;
 113
 114   /// Add attributes to an argument.
 115   void addAttrs(AttrBuilder &B);
 116
 117   void addAttr(Attribute::AttrKind Kind);
 118
 119   void addAttr(Attribute Attr);
 120
 121   /// Remove attributes from an argument.
 122   void removeAttr(Attribute::AttrKind Kind);
 123
 124   /// Check if an argument has a given attribute.
 125   bool hasAttribute(Attribute::AttrKind Kind) const;
 126
 127   Attribute getAttribute(Attribute::AttrKind Kind) const;
 128
 129   /// Method for support type inquiry through isa, cast, and dyn_cast.
 130   static bool classof(const Value *V) {
 131     return V->getValueID() == ArgumentVal;
 132   }
 133 };
 134
 135 } // End llvm namespace
 136
 137 #endif