1//===--- LambdaCapture.h - Types for C++ Lambda Captures --------*- 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/// \file
11/// \brief Defines the LambdaCapture class.
12///
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_CLANG_AST_LAMBDACAPTURE_H
16#define LLVM_CLANG_AST_LAMBDACAPTURE_H
17
18#include "clang/AST/Decl.h"
19#include "clang/Basic/Lambda.h"
20#include "llvm/ADT/PointerIntPair.h"
21
22namespace clang {
23
24/// \brief Describes the capture of a variable or of \c this, or of a
25/// C++1y init-capture.
26class LambdaCapture {
27  enum {
28    /// \brief Flag used by the Capture class to indicate that the given
29    /// capture was implicit.
30    Capture_Implicit = 0x01,
31
32    /// \brief Flag used by the Capture class to indicate that the
33    /// given capture was by-copy.
34    ///
35    /// This includes the case of a non-reference init-capture.
36    Capture_ByCopy = 0x02
37  };
38
39  llvm::PointerIntPair<Decl *, 2> DeclAndBits;
40  SourceLocation Loc;
41  SourceLocation EllipsisLoc;
42
43  friend class ASTStmtReader;
44  friend class ASTStmtWriter;
45
46public:
47  /// \brief Create a new capture of a variable or of \c this.
48  ///
49  /// \param Loc The source location associated with this capture.
50  ///
51  /// \param Kind The kind of capture (this, byref, bycopy), which must
52  /// not be init-capture.
53  ///
54  /// \param Implicit Whether the capture was implicit or explicit.
55  ///
56  /// \param Var The local variable being captured, or null if capturing
57  /// \c this.
58  ///
59  /// \param EllipsisLoc The location of the ellipsis (...) for a
60  /// capture that is a pack expansion, or an invalid source
61  /// location to indicate that this is not a pack expansion.
62  LambdaCapture(SourceLocation Loc, bool Implicit, LambdaCaptureKind Kind,
63                VarDecl *Var = nullptr,
64                SourceLocation EllipsisLoc = SourceLocation());
65
66  /// \brief Determine the kind of capture.
67  LambdaCaptureKind getCaptureKind() const;
68
69  /// \brief Determine whether this capture handles the C++ \c this
70  /// pointer.
71  bool capturesThis() const { return DeclAndBits.getPointer() == nullptr; }
72
73  /// \brief Determine whether this capture handles a variable.
74  bool capturesVariable() const {
75    return dyn_cast_or_null<VarDecl>(DeclAndBits.getPointer());
76  }
77
78  /// \brief Determine whether this is an init-capture.
79  bool isInitCapture() const {
80    return capturesVariable() && getCapturedVar()->isInitCapture();
81  }
82
83  /// \brief Retrieve the declaration of the local variable being
84  /// captured.
85  ///
86  /// This operation is only valid if this capture is a variable capture
87  /// (other than a capture of \c this).
88  VarDecl *getCapturedVar() const {
89    assert(capturesVariable() && "No variable available for 'this' capture");
90    return cast<VarDecl>(DeclAndBits.getPointer());
91  }
92
93  /// \brief Determine whether this was an implicit capture (not
94  /// written between the square brackets introducing the lambda).
95  bool isImplicit() const { return DeclAndBits.getInt() & Capture_Implicit; }
96
97  /// \brief Determine whether this was an explicit capture (written
98  /// between the square brackets introducing the lambda).
99  bool isExplicit() const { return !isImplicit(); }
100
101  /// \brief Retrieve the source location of the capture.
102  ///
103  /// For an explicit capture, this returns the location of the
104  /// explicit capture in the source. For an implicit capture, this
105  /// returns the location at which the variable or \c this was first
106  /// used.
107  SourceLocation getLocation() const { return Loc; }
108
109  /// \brief Determine whether this capture is a pack expansion,
110  /// which captures a function parameter pack.
111  bool isPackExpansion() const { return EllipsisLoc.isValid(); }
112
113  /// \brief Retrieve the location of the ellipsis for a capture
114  /// that is a pack expansion.
115  SourceLocation getEllipsisLoc() const {
116    assert(isPackExpansion() && "No ellipsis location for a non-expansion");
117    return EllipsisLoc;
118  }
119};
120
121} // end namespace clang
122
123#endif // LLVM_CLANG_AST_LAMBDACAPTURE_H
124