1//===--- MacroArgs.h - Formal argument info for Macros ----------*- 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 defines the MacroArgs interface.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CLANG_LEX_MACROARGS_H
15#define LLVM_CLANG_LEX_MACROARGS_H
16
17#include "clang/Basic/LLVM.h"
18#include "llvm/ADT/ArrayRef.h"
19#include <vector>
20
21namespace clang {
22  class MacroInfo;
23  class Preprocessor;
24  class Token;
25  class SourceLocation;
26
27/// MacroArgs - An instance of this class captures information about
28/// the formal arguments specified to a function-like macro invocation.
29class MacroArgs {
30  /// NumUnexpArgTokens - The number of raw, unexpanded tokens for the
31  /// arguments.  All of the actual argument tokens are allocated immediately
32  /// after the MacroArgs object in memory.  This is all of the arguments
33  /// concatenated together, with 'EOF' markers at the end of each argument.
34  unsigned NumUnexpArgTokens;
35
36  /// VarargsElided - True if this is a C99 style varargs macro invocation and
37  /// there was no argument specified for the "..." argument.  If the argument
38  /// was specified (even empty) or this isn't a C99 style varargs function, or
39  /// if in strict mode and the C99 varargs macro had only a ... argument, this
40  /// is false.
41  bool VarargsElided;
42
43  /// PreExpArgTokens - Pre-expanded tokens for arguments that need them.  Empty
44  /// if not yet computed.  This includes the EOF marker at the end of the
45  /// stream.
46  std::vector<std::vector<Token> > PreExpArgTokens;
47
48  /// StringifiedArgs - This contains arguments in 'stringified' form.  If the
49  /// stringified form of an argument has not yet been computed, this is empty.
50  std::vector<Token> StringifiedArgs;
51
52  /// ArgCache - This is a linked list of MacroArgs objects that the
53  /// Preprocessor owns which we use to avoid thrashing malloc/free.
54  MacroArgs *ArgCache;
55
56  MacroArgs(unsigned NumToks, bool varargsElided)
57    : NumUnexpArgTokens(NumToks), VarargsElided(varargsElided),
58      ArgCache(nullptr) {}
59  ~MacroArgs() = default;
60
61public:
62  /// MacroArgs ctor function - Create a new MacroArgs object with the specified
63  /// macro and argument info.
64  static MacroArgs *create(const MacroInfo *MI,
65                           ArrayRef<Token> UnexpArgTokens,
66                           bool VarargsElided, Preprocessor &PP);
67
68  /// destroy - Destroy and deallocate the memory for this object.
69  ///
70  void destroy(Preprocessor &PP);
71
72  /// ArgNeedsPreexpansion - If we can prove that the argument won't be affected
73  /// by pre-expansion, return false.  Otherwise, conservatively return true.
74  bool ArgNeedsPreexpansion(const Token *ArgTok, Preprocessor &PP) const;
75
76  /// getUnexpArgument - Return a pointer to the first token of the unexpanded
77  /// token list for the specified formal.
78  ///
79  const Token *getUnexpArgument(unsigned Arg) const;
80
81  /// getArgLength - Given a pointer to an expanded or unexpanded argument,
82  /// return the number of tokens, not counting the EOF, that make up the
83  /// argument.
84  static unsigned getArgLength(const Token *ArgPtr);
85
86  /// getPreExpArgument - Return the pre-expanded form of the specified
87  /// argument.
88  const std::vector<Token> &
89    getPreExpArgument(unsigned Arg, const MacroInfo *MI, Preprocessor &PP);
90
91  /// getStringifiedArgument - Compute, cache, and return the specified argument
92  /// that has been 'stringified' as required by the # operator.
93  const Token &getStringifiedArgument(unsigned ArgNo, Preprocessor &PP,
94                                      SourceLocation ExpansionLocStart,
95                                      SourceLocation ExpansionLocEnd);
96
97  /// getNumArguments - Return the number of arguments passed into this macro
98  /// invocation.
99  unsigned getNumArguments() const { return NumUnexpArgTokens; }
100
101
102  /// isVarargsElidedUse - Return true if this is a C99 style varargs macro
103  /// invocation and there was no argument specified for the "..." argument.  If
104  /// the argument was specified (even empty) or this isn't a C99 style varargs
105  /// function, or if in strict mode and the C99 varargs macro had only a ...
106  /// argument, this returns false.
107  bool isVarargsElidedUse() const { return VarargsElided; }
108
109  /// StringifyArgument - Implement C99 6.10.3.2p2, converting a sequence of
110  /// tokens into the literal string token that should be produced by the C #
111  /// preprocessor operator.  If Charify is true, then it should be turned into
112  /// a character literal for the Microsoft charize (#@) extension.
113  ///
114  static Token StringifyArgument(const Token *ArgToks,
115                                 Preprocessor &PP, bool Charify,
116                                 SourceLocation ExpansionLocStart,
117                                 SourceLocation ExpansionLocEnd);
118
119
120  /// deallocate - This should only be called by the Preprocessor when managing
121  /// its freelist.
122  MacroArgs *deallocate();
123};
124
125}  // end namespace clang
126
127#endif
128