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 138