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
21namespace 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.
29class Argument final : public Value {
30 Function *Parent;
31 unsigned ArgNo;
32
33 friend class Function;
34 void setParent(Function *parent);
35
36public:
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 /// If AllowUndefOrPoison is true, respect the semantics of nonnull attribute
56 /// and return true even if the argument can be undef or poison.
57 bool hasNonNullAttr(bool AllowUndefOrPoison = true) const;
58
59 /// If this argument has the dereferenceable attribute, return the number of
60 /// bytes known to be dereferenceable. Otherwise, zero is returned.
61 uint64_t getDereferenceableBytes() const;
62
63 /// If this argument has the dereferenceable_or_null attribute, return the
64 /// number of bytes known to be dereferenceable. Otherwise, zero is returned.
65 uint64_t getDereferenceableOrNullBytes() const;
66
67 /// Return true if this argument has the byval attribute.
68 bool hasByValAttr() const;
69
70 /// Return true if this argument has the byref attribute.
71 bool hasByRefAttr() const;
72
73 /// Return true if this argument has the swiftself attribute.
74 bool hasSwiftSelfAttr() const;
75
76 /// Return true if this argument has the swifterror attribute.
77 bool hasSwiftErrorAttr() const;
78
79 /// Return true if this argument has the byval, inalloca, or preallocated
80 /// attribute. These attributes represent arguments being passed by value,
81 /// with an associated copy between the caller and callee
82 bool hasPassPointeeByValueCopyAttr() const;
83
84 /// If this argument satisfies has hasPassPointeeByValueAttr, return the
85 /// in-memory ABI size copied to the stack for the call. Otherwise, return 0.
86 uint64_t getPassPointeeByValueCopySize(const DataLayout &DL) const;
87
88 /// Return true if this argument has the byval, sret, inalloca, preallocated,
89 /// or byref attribute. These attributes represent arguments being passed by
90 /// value (which may or may not involve a stack copy)
91 bool hasPointeeInMemoryValueAttr() const;
92
93 /// If hasPointeeInMemoryValueAttr returns true, the in-memory ABI type is
94 /// returned. Otherwise, nullptr.
95 Type *getPointeeInMemoryValueType() const;
96
97 /// If this is a byval or inalloca argument, return its alignment.
98 /// FIXME: Remove this function once transition to Align is over.
99 /// Use getParamAlign() instead.
100 unsigned getParamAlignment() const;
101
102 /// If this is a byval or inalloca argument, return its alignment.
103 MaybeAlign getParamAlign() const;
104
105 MaybeAlign getParamStackAlign() const;
106
107 /// If this is a byval argument, return its type.
108 Type *getParamByValType() const;
109
110 /// If this is an sret argument, return its type.
111 Type *getParamStructRetType() const;
112
113 /// If this is a byref argument, return its type.
114 Type *getParamByRefType() const;
115
116 /// If this is an inalloca argument, return its type.
117 Type *getParamInAllocaType() const;
118
119 /// Return true if this argument has the nest attribute.
120 bool hasNestAttr() const;
121
122 /// Return true if this argument has the noalias attribute.
123 bool hasNoAliasAttr() const;
124
125 /// Return true if this argument has the nocapture attribute.
126 bool hasNoCaptureAttr() const;
127
128 /// Return true if this argument has the nofree attribute.
129 bool hasNoFreeAttr() const;
130
131 /// Return true if this argument has the sret attribute.
132 bool hasStructRetAttr() const;
133
134 /// Return true if this argument has the inreg attribute.
135 bool hasInRegAttr() const;
136
137 /// Return true if this argument has the returned attribute.
138 bool hasReturnedAttr() const;
139
140 /// Return true if this argument has the readonly or readnone attribute.
141 bool onlyReadsMemory() const;
142
143 /// Return true if this argument has the inalloca attribute.
144 bool hasInAllocaAttr() const;
145
146 /// Return true if this argument has the preallocated attribute.
147 bool hasPreallocatedAttr() const;
148
149 /// Return true if this argument has the zext attribute.
150 bool hasZExtAttr() const;
151
152 /// Return true if this argument has the sext attribute.
153 bool hasSExtAttr() const;
154
155 /// Add attributes to an argument.
156 void addAttrs(AttrBuilder &B);
157
158 void addAttr(Attribute::AttrKind Kind);
159
160 void addAttr(Attribute Attr);
161
162 /// Remove attributes from an argument.
163 void removeAttr(Attribute::AttrKind Kind);
164
165 /// Check if an argument has a given attribute.
166 bool hasAttribute(Attribute::AttrKind Kind) const;
167
168 Attribute getAttribute(Attribute::AttrKind Kind) const;
169
170 /// Method for support type inquiry through isa, cast, and dyn_cast.
171 static bool classof(const Value *V) {
172 return V->getValueID() == ArgumentVal;
173 }
174};
175
176} // End llvm namespace
177
178#endif
179