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
22namespace llvm {
23
24template<typename ValueSubClass, typename ItemParentClass>
25  class SymbolTableListTraits;
26
27/// \brief LLVM Argument representation
28///
29/// This class represents an incoming formal argument to a Function. A formal
30/// argument, since it is ``formal'', does not contain an actual value but
31/// instead represents the type, argument number, and attributes of an argument
32/// for a specific function. When used in the body of said function, the
33/// argument of course represents the value of the actual argument that the
34/// function was called with.
35class Argument : public Value, public ilist_node<Argument> {
36  virtual void anchor();
37  Function *Parent;
38
39  friend class SymbolTableListTraits<Argument, Function>;
40  void setParent(Function *parent);
41
42public:
43  /// \brief Constructor.
44  ///
45  /// If \p F is specified, the argument is inserted at the end of the argument
46  /// list for \p F.
47  explicit Argument(Type *Ty, const Twine &Name = "", Function *F = nullptr);
48
49  inline const Function *getParent() const { return Parent; }
50  inline       Function *getParent()       { return Parent; }
51
52  /// \brief Return the index of this formal argument in its containing
53  /// function.
54  ///
55  /// For example in "void foo(int a, float b)" a is 0 and b is 1.
56  unsigned getArgNo() const;
57
58  /// \brief Return true if this argument has the nonnull attribute on it in
59  /// its containing function. Also returns true if at least one byte is known
60  /// to be dereferenceable and the pointer is in addrspace(0).
61  bool hasNonNullAttr() const;
62
63  /// \brief If this argument has the dereferenceable attribute on it in its
64  /// containing function, return the number of bytes known to be
65  /// dereferenceable. Otherwise, zero is returned.
66  uint64_t getDereferenceableBytes() const;
67
68  /// \brief Return true if this argument has the byval attribute on it in its
69  /// containing function.
70  bool hasByValAttr() const;
71
72  /// \brief Return true if this argument has the byval attribute or inalloca
73  /// attribute on it in its containing function.  These attributes both
74  /// represent arguments being passed by value.
75  bool hasByValOrInAllocaAttr() const;
76
77  /// \brief If this is a byval or inalloca argument, return its alignment.
78  unsigned getParamAlignment() const;
79
80  /// \brief Return true if this argument has the nest attribute on it in its
81  /// containing function.
82  bool hasNestAttr() const;
83
84  /// \brief Return true if this argument has the noalias attribute on it in its
85  /// containing function.
86  bool hasNoAliasAttr() const;
87
88  /// \brief Return true if this argument has the nocapture attribute on it in
89  /// its containing function.
90  bool hasNoCaptureAttr() const;
91
92  /// \brief Return true if this argument has the sret attribute on it in its
93  /// containing function.
94  bool hasStructRetAttr() const;
95
96  /// \brief Return true if this argument has the returned attribute on it in
97  /// its containing function.
98  bool hasReturnedAttr() const;
99
100  /// \brief Return true if this argument has the readonly or readnone attribute
101  /// on it in its containing function.
102  bool onlyReadsMemory() const;
103
104  /// \brief Return true if this argument has the inalloca attribute on it in
105  /// its containing function.
106  bool hasInAllocaAttr() const;
107
108  /// \brief Return true if this argument has the zext attribute on it in its
109  /// containing function.
110  bool hasZExtAttr() const;
111
112  /// \brief Return true if this argument has the sext attribute on it in its
113  /// containing function.
114  bool hasSExtAttr() const;
115
116  /// \brief Add a Attribute to an argument.
117  void addAttr(AttributeSet AS);
118
119  /// \brief Remove a Attribute from an argument.
120  void removeAttr(AttributeSet AS);
121
122  /// \brief Method for support type inquiry through isa, cast, and
123  /// dyn_cast.
124  static inline bool classof(const Value *V) {
125    return V->getValueID() == ArgumentVal;
126  }
127};
128
129} // End llvm namespace
130
131#endif
132