clang  10.0.0svn
MacroArgs.h
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1 //===--- MacroArgs.h - Formal argument info for Macros ----------*- 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 defines the MacroArgs interface.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_CLANG_LEX_MACROARGS_H
14 #define LLVM_CLANG_LEX_MACROARGS_H
15 
16 #include "clang/Basic/LLVM.h"
17 #include "clang/Lex/Token.h"
18 #include "llvm/ADT/ArrayRef.h"
19 #include "llvm/Support/TrailingObjects.h"
20 #include <vector>
21 
22 namespace clang {
23  class MacroInfo;
24  class Preprocessor;
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.
29 class MacroArgs final
30  : private llvm::TrailingObjects<MacroArgs, Token> {
31 
32  friend TrailingObjects;
33  /// NumUnexpArgTokens - The number of raw, unexpanded tokens for the
34  /// arguments. All of the actual argument tokens are allocated immediately
35  /// after the MacroArgs object in memory. This is all of the arguments
36  /// concatenated together, with 'EOF' markers at the end of each argument.
37  unsigned NumUnexpArgTokens;
38 
39  /// VarargsElided - True if this is a C99 style varargs macro invocation and
40  /// there was no argument specified for the "..." argument. If the argument
41  /// was specified (even empty) or this isn't a C99 style varargs function, or
42  /// if in strict mode and the C99 varargs macro had only a ... argument, this
43  /// is false.
44  bool VarargsElided;
45 
46  /// PreExpArgTokens - Pre-expanded tokens for arguments that need them. Empty
47  /// if not yet computed. This includes the EOF marker at the end of the
48  /// stream.
49  std::vector<std::vector<Token> > PreExpArgTokens;
50 
51  /// ArgCache - This is a linked list of MacroArgs objects that the
52  /// Preprocessor owns which we use to avoid thrashing malloc/free.
53  MacroArgs *ArgCache;
54 
55  /// MacroArgs - The number of arguments the invoked macro expects.
56  unsigned NumMacroArgs;
57 
58  MacroArgs(unsigned NumToks, bool varargsElided, unsigned MacroArgs)
59  : NumUnexpArgTokens(NumToks), VarargsElided(varargsElided),
60  ArgCache(nullptr), NumMacroArgs(MacroArgs) {}
61  ~MacroArgs() = default;
62 
63 public:
64  /// MacroArgs ctor function - Create a new MacroArgs object with the specified
65  /// macro and argument info.
66  static MacroArgs *create(const MacroInfo *MI,
67  ArrayRef<Token> UnexpArgTokens,
68  bool VarargsElided, Preprocessor &PP);
69 
70  /// destroy - Destroy and deallocate the memory for this object.
71  ///
72  void destroy(Preprocessor &PP);
73 
74  /// ArgNeedsPreexpansion - If we can prove that the argument won't be affected
75  /// by pre-expansion, return false. Otherwise, conservatively return true.
76  bool ArgNeedsPreexpansion(const Token *ArgTok, Preprocessor &PP) const;
77 
78  /// getUnexpArgument - Return a pointer to the first token of the unexpanded
79  /// token list for the specified formal.
80  ///
81  const Token *getUnexpArgument(unsigned Arg) const;
82 
83  /// getArgLength - Given a pointer to an expanded or unexpanded argument,
84  /// return the number of tokens, not counting the EOF, that make up the
85  /// argument.
86  static unsigned getArgLength(const Token *ArgPtr);
87 
88  /// getPreExpArgument - Return the pre-expanded form of the specified
89  /// argument.
90  const std::vector<Token> &
91  getPreExpArgument(unsigned Arg, Preprocessor &PP);
92 
93  /// getNumMacroArguments - Return the number of arguments the invoked macro
94  /// expects.
95  unsigned getNumMacroArguments() const { return NumMacroArgs; }
96 
97  /// isVarargsElidedUse - Return true if this is a C99 style varargs macro
98  /// invocation and there was no argument specified for the "..." argument. If
99  /// the argument was specified (even empty) or this isn't a C99 style varargs
100  /// function, or if in strict mode and the C99 varargs macro had only a ...
101  /// argument, this returns false.
102  bool isVarargsElidedUse() const { return VarargsElided; }
103 
104  /// Returns true if the macro was defined with a variadic (ellipsis) parameter
105  /// AND was invoked with at least one token supplied as a variadic argument
106  /// (after pre-expansion).
107  ///
108  /// \code
109  /// #define F(a) a
110  /// #define V(a, ...) __VA_OPT__(a)
111  /// F() <-- returns false on this invocation.
112  /// V(,a) <-- returns true on this invocation.
113  /// V(,) <-- returns false on this invocation.
114  /// V(,F()) <-- returns false on this invocation.
115  /// \endcode
116  ///
117  bool invokedWithVariadicArgument(const MacroInfo *const MI, Preprocessor &PP);
118 
119  /// StringifyArgument - Implement C99 6.10.3.2p2, converting a sequence of
120  /// tokens into the literal string token that should be produced by the C #
121  /// preprocessor operator. If Charify is true, then it should be turned into
122  /// a character literal for the Microsoft charize (#@) extension.
123  ///
124  static Token StringifyArgument(const Token *ArgToks,
125  Preprocessor &PP, bool Charify,
126  SourceLocation ExpansionLocStart,
127  SourceLocation ExpansionLocEnd);
128 
129 
130  /// deallocate - This should only be called by the Preprocessor when managing
131  /// its freelist.
132  MacroArgs *deallocate();
133 };
134 
135 } // end namespace clang
136 
137 #endif
bool ArgNeedsPreexpansion(const Token *ArgTok, Preprocessor &PP) const
ArgNeedsPreexpansion - If we can prove that the argument won&#39;t be affected by pre-expansion, return false.
Definition: MacroArgs.cpp:146
bool isVarargsElidedUse() const
isVarargsElidedUse - Return true if this is a C99 style varargs macro invocation and there was no arg...
Definition: MacroArgs.h:102
Token - This structure provides full information about a lexed token.
Definition: Token.h:34
Forward-declares and imports various common LLVM datatypes that clang wants to use unqualified...
void destroy(Preprocessor &PP)
destroy - Destroy and deallocate the memory for this object.
Definition: MacroArgs.cpp:78
static Token StringifyArgument(const Token *ArgToks, Preprocessor &PP, bool Charify, SourceLocation ExpansionLocStart, SourceLocation ExpansionLocEnd)
StringifyArgument - Implement C99 6.10.3.2p2, converting a sequence of tokens into the literal string...
Definition: MacroArgs.cpp:208
bool invokedWithVariadicArgument(const MacroInfo *const MI, Preprocessor &PP)
Returns true if the macro was defined with a variadic (ellipsis) parameter AND was invoked with at le...
Definition: MacroArgs.cpp:136
MacroArgs - An instance of this class captures information about the formal arguments specified to a ...
Definition: MacroArgs.h:29
MacroArgs * deallocate()
deallocate - This should only be called by the Preprocessor when managing its freelist.
Definition: MacroArgs.cpp:91
Encodes a location in the source.
Dataflow Directional Tag Classes.
const std::vector< Token > & getPreExpArgument(unsigned Arg, Preprocessor &PP)
getPreExpArgument - Return the pre-expanded form of the specified argument.
Definition: MacroArgs.cpp:161
static unsigned getArgLength(const Token *ArgPtr)
getArgLength - Given a pointer to an expanded or unexpanded argument, return the number of tokens...
Definition: MacroArgs.cpp:108
unsigned getNumMacroArguments() const
getNumMacroArguments - Return the number of arguments the invoked macro expects.
Definition: MacroArgs.h:95
Encapsulates the data about a macro definition (e.g.
Definition: MacroInfo.h:39
friend TrailingObjects
Definition: OpenMPClause.h:98
static MacroArgs * create(const MacroInfo *MI, ArrayRef< Token > UnexpArgTokens, bool VarargsElided, Preprocessor &PP)
MacroArgs ctor function - Create a new MacroArgs object with the specified macro and argument info...
Definition: MacroArgs.cpp:24
const Token * getUnexpArgument(unsigned Arg) const
getUnexpArgument - Return a pointer to the first token of the unexpanded token list for the specified...
Definition: MacroArgs.cpp:118
Engages in a tight little dance with the lexer to efficiently preprocess tokens.
Definition: Preprocessor.h:125