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/IR/Attributes.h" 18 #include "llvm/IR/Value.h" 19 20 namespace llvm { 21 22 /// This class represents an incoming formal argument to a Function. A formal 23 /// argument, since it is ``formal'', does not contain an actual value but 24 /// instead represents the type, argument number, and attributes of an argument 25 /// for a specific function. When used in the body of said function, the 26 /// argument of course represents the value of the actual argument that the 27 /// function was called with. 28 class Argument final : public Value { 29 Function *Parent; 30 unsigned ArgNo; 31 32 friend class Function; 33 void setParent(Function *parent); 34 35 public: 36 /// Argument constructor. 37 explicit Argument(Type *Ty, const Twine &Name = "", Function *F = nullptr, 38 unsigned ArgNo = 0); 39 40 inline const Function *getParent() const { return Parent; } 41 inline Function *getParent() { return Parent; } 42 43 /// Return the index of this formal argument in its containing function. 44 /// 45 /// For example in "void foo(int a, float b)" a is 0 and b is 1. 46 unsigned getArgNo() const { 47 assert(Parent && "can't get number of unparented arg"); 48 return ArgNo; 49 } 50 51 /// Return true if this argument has the nonnull attribute. Also returns true 52 /// if at least one byte is known to be dereferenceable and the pointer is in 53 /// addrspace(0). 54 /// If AllowUndefOrPoison is true, respect the semantics of nonnull attribute 55 /// and return true even if the argument can be undef or poison. 56 bool hasNonNullAttr(bool AllowUndefOrPoison = true) 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 byref attribute. 70 bool hasByRefAttr() const; 71 72 /// Return true if this argument has the swiftself attribute. 73 bool hasSwiftSelfAttr() const; 74 75 /// Return true if this argument has the swifterror attribute. 76 bool hasSwiftErrorAttr() const; 77 78 /// Return true if this argument has the byval, inalloca, or preallocated 79 /// attribute. These attributes represent arguments being passed by value, 80 /// with an associated copy between the caller and callee 81 bool hasPassPointeeByValueCopyAttr() const; 82 83 /// If this argument satisfies has hasPassPointeeByValueAttr, return the 84 /// in-memory ABI size copied to the stack for the call. Otherwise, return 0. 85 uint64_t getPassPointeeByValueCopySize(const DataLayout &DL) const; 86 87 /// Return true if this argument has the byval, sret, inalloca, preallocated, 88 /// or byref attribute. These attributes represent arguments being passed by 89 /// value (which may or may not involve a stack copy) 90 bool hasPointeeInMemoryValueAttr() const; 91 92 /// If hasPointeeInMemoryValueAttr returns true, the in-memory ABI type is 93 /// returned. Otherwise, nullptr. 94 Type *getPointeeInMemoryValueType() const; 95 96 /// If this is a byval or inalloca argument, return its alignment. 97 /// FIXME: Remove this function once transition to Align is over. 98 /// Use getParamAlign() instead. 99 uint64_t getParamAlignment() const; 100 101 /// If this is a byval or inalloca argument, return its alignment. 102 MaybeAlign getParamAlign() const; 103 104 MaybeAlign getParamStackAlign() const; 105 106 /// If this is a byval argument, return its type. 107 Type *getParamByValType() const; 108 109 /// If this is an sret argument, return its type. 110 Type *getParamStructRetType() const; 111 112 /// If this is a byref argument, return its type. 113 Type *getParamByRefType() const; 114 115 /// If this is an inalloca argument, return its type. 116 Type *getParamInAllocaType() const; 117 118 /// Return true if this argument has the nest attribute. 119 bool hasNestAttr() const; 120 121 /// Return true if this argument has the noalias attribute. 122 bool hasNoAliasAttr() const; 123 124 /// Return true if this argument has the nocapture attribute. 125 bool hasNoCaptureAttr() const; 126 127 /// Return true if this argument has the nofree attribute. 128 bool hasNoFreeAttr() const; 129 130 /// Return true if this argument has the sret attribute. 131 bool hasStructRetAttr() const; 132 133 /// Return true if this argument has the inreg attribute. 134 bool hasInRegAttr() const; 135 136 /// Return true if this argument has the returned attribute. 137 bool hasReturnedAttr() const; 138 139 /// Return true if this argument has the readonly or readnone attribute. 140 bool onlyReadsMemory() const; 141 142 /// Return true if this argument has the inalloca attribute. 143 bool hasInAllocaAttr() const; 144 145 /// Return true if this argument has the preallocated attribute. 146 bool hasPreallocatedAttr() const; 147 148 /// Return true if this argument has the zext attribute. 149 bool hasZExtAttr() const; 150 151 /// Return true if this argument has the sext attribute. 152 bool hasSExtAttr() const; 153 154 /// Add attributes to an argument. 155 void addAttrs(AttrBuilder &B); 156 157 void addAttr(Attribute::AttrKind Kind); 158 159 void addAttr(Attribute Attr); 160 161 /// Remove attributes from an argument. 162 void removeAttr(Attribute::AttrKind Kind); 163 164 void removeAttrs(const AttributeMask &AM); 165 166 /// Check if an argument has a given attribute. 167 bool hasAttribute(Attribute::AttrKind Kind) const; 168 169 Attribute getAttribute(Attribute::AttrKind Kind) const; 170 171 /// Method for support type inquiry through isa, cast, and dyn_cast. 172 static bool classof(const Value *V) { 173 return V->getValueID() == ArgumentVal; 174 } 175 }; 176 177 } // End llvm namespace 178 179 #endif 180