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_MACROARGS_H
15#define LLVM_CLANG_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() {}
60public:
61  /// MacroArgs ctor function - Create a new MacroArgs object with the specified
62  /// macro and argument info.
63  static MacroArgs *create(const MacroInfo *MI,
64                           ArrayRef<Token> UnexpArgTokens,
65                           bool VarargsElided, Preprocessor &PP);
66
67  /// destroy - Destroy and deallocate the memory for this object.
68  ///
69  void destroy(Preprocessor &PP);
70
71  /// ArgNeedsPreexpansion - If we can prove that the argument won't be affected
72  /// by pre-expansion, return false.  Otherwise, conservatively return true.
73  bool ArgNeedsPreexpansion(const Token *ArgTok, Preprocessor &PP) const;
74
75  /// getUnexpArgument - Return a pointer to the first token of the unexpanded
76  /// token list for the specified formal.
77  ///
78  const Token *getUnexpArgument(unsigned Arg) const;
79
80  /// getArgLength - Given a pointer to an expanded or unexpanded argument,
81  /// return the number of tokens, not counting the EOF, that make up the
82  /// argument.
83  static unsigned getArgLength(const Token *ArgPtr);
84
85  /// getPreExpArgument - Return the pre-expanded form of the specified
86  /// argument.
87  const std::vector<Token> &
88    getPreExpArgument(unsigned Arg, const MacroInfo *MI, Preprocessor &PP);
89
90  /// getStringifiedArgument - Compute, cache, and return the specified argument
91  /// that has been 'stringified' as required by the # operator.
92  const Token &getStringifiedArgument(unsigned ArgNo, Preprocessor &PP,
93                                      SourceLocation ExpansionLocStart,
94                                      SourceLocation ExpansionLocEnd);
95
96  /// getNumArguments - Return the number of arguments passed into this macro
97  /// invocation.
98  unsigned getNumArguments() const { return NumUnexpArgTokens; }
99
100
101  /// isVarargsElidedUse - Return true if this is a C99 style varargs macro
102  /// invocation and there was no argument specified for the "..." argument.  If
103  /// the argument was specified (even empty) or this isn't a C99 style varargs
104  /// function, or if in strict mode and the C99 varargs macro had only a ...
105  /// argument, this returns false.
106  bool isVarargsElidedUse() const { return VarargsElided; }
107
108  /// StringifyArgument - Implement C99 6.10.3.2p2, converting a sequence of
109  /// tokens into the literal string token that should be produced by the C #
110  /// preprocessor operator.  If Charify is true, then it should be turned into
111  /// a character literal for the Microsoft charize (#@) extension.
112  ///
113  static Token StringifyArgument(const Token *ArgToks,
114                                 Preprocessor &PP, bool Charify,
115                                 SourceLocation ExpansionLocStart,
116                                 SourceLocation ExpansionLocEnd);
117
118
119  /// deallocate - This should only be called by the Preprocessor when managing
120  /// its freelist.
121  MacroArgs *deallocate();
122};
123
124}  // end namespace clang
125
126#endif
127