MacroInfo.h revision 2c1ab9079cb117dc0470ab423fe0bc5177546339 
1//===--- MacroInfo.h - Information about #defined identifiers ---*- 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 MacroInfo interface.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CLANG_MACROINFO_H
15#define LLVM_CLANG_MACROINFO_H
16
17#include "clang/Lex/Token.h"
18#include "llvm/ADT/SmallVector.h"
19#include "llvm/Support/Allocator.h"
20#include <vector>
21#include <cassert>
22
23namespace clang {
24  class Preprocessor;
25
26/// MacroInfo - Each identifier that is #define'd has an instance of this class
27/// associated with it, used to implement macro expansion.
28class MacroInfo {
29  //===--------------------------------------------------------------------===//
30  // State set when the macro is defined.
31
32  /// Location - This is the place the macro is defined.
33  SourceLocation Location;
34  /// EndLocation - The location of the last token in the macro.
35  SourceLocation EndLocation;
36
37  /// Arguments - The list of arguments for a function-like macro.  This can be
38  /// empty, for, e.g. "#define X()".  In a C99-style variadic macro, this
39  /// includes the __VA_ARGS__ identifier on the list.
40  IdentifierInfo **ArgumentList;
41  unsigned NumArguments;
42
43  /// ReplacementTokens - This is the list of tokens that the macro is defined
44  /// to.
45  llvm::SmallVector<Token, 8> ReplacementTokens;
46
47  /// IsFunctionLike - True if this macro is a function-like macro, false if it
48  /// is an object-like macro.
49  bool IsFunctionLike : 1;
50
51  /// IsC99Varargs - True if this macro is of the form "#define X(...)" or
52  /// "#define X(Y,Z,...)".  The __VA_ARGS__ token should be replaced with the
53  /// contents of "..." in an invocation.
54  bool IsC99Varargs : 1;
55
56  /// IsGNUVarargs -  True if this macro is of the form "#define X(a...)".  The
57  /// "a" identifier in the replacement list will be replaced with all arguments
58  /// of the macro starting with the specified one.
59  bool IsGNUVarargs : 1;
60
61  /// IsBuiltinMacro - True if this is a builtin macro, such as __LINE__, and if
62  /// it has not yet been redefined or undefined.
63  bool IsBuiltinMacro : 1;
64
65  /// IsFromPCH - True if this macro was loaded from a PCH file.
66  bool IsFromPCH : 1;
67
68private:
69  //===--------------------------------------------------------------------===//
70  // State that changes as the macro is used.
71
72  /// IsDisabled - True if we have started an expansion of this macro already.
73  /// This disbles recursive expansion, which would be quite bad for things like
74  /// #define A A.
75  bool IsDisabled : 1;
76
77  /// IsUsed - True if this macro is either defined in the main file and has
78  /// been used, or if it is not defined in the main file.  This is used to
79  /// emit -Wunused-macros diagnostics.
80  bool IsUsed : 1;
81
82  /// AllowRedefinitionsWithoutWarning - True if this macro can be redefined
83  /// without emitting a warning.
84  bool IsAllowRedefinitionsWithoutWarning : 1;
85
86   ~MacroInfo() {
87    assert(ArgumentList == 0 && "Didn't call destroy before dtor!");
88  }
89
90public:
91  MacroInfo(SourceLocation DefLoc);
92  MacroInfo(const MacroInfo &MI, llvm::BumpPtrAllocator &PPAllocator);
93
94  /// FreeArgumentList - Free the argument list of the macro, restoring it to a
95  /// state where it can be reused for other devious purposes.
96  void FreeArgumentList() {
97    ArgumentList = 0;
98    NumArguments = 0;
99  }
100
101  /// Destroy - destroy this MacroInfo object.
102  void Destroy() {
103    FreeArgumentList();
104    this->~MacroInfo();
105  }
106
107  /// getDefinitionLoc - Return the location that the macro was defined at.
108  ///
109  SourceLocation getDefinitionLoc() const { return Location; }
110
111  /// setDefinitionEndLoc - Set the location of the last token in the macro.
112  ///
113  void setDefinitionEndLoc(SourceLocation EndLoc) { EndLocation = EndLoc; }
114  /// getDefinitionEndLoc - Return the location of the last token in the macro.
115  ///
116  SourceLocation getDefinitionEndLoc() const { return EndLocation; }
117
118  /// isIdenticalTo - Return true if the specified macro definition is equal to
119  /// this macro in spelling, arguments, and whitespace.  This is used to emit
120  /// duplicate definition warnings.  This implements the rules in C99 6.10.3.
121  bool isIdenticalTo(const MacroInfo &Other, Preprocessor &PP) const;
122
123  /// setIsBuiltinMacro - Set or clear the isBuiltinMacro flag.
124  ///
125  void setIsBuiltinMacro(bool Val = true) {
126    IsBuiltinMacro = Val;
127  }
128
129  /// setIsUsed - Set the value of the IsUsed flag.
130  ///
131  void setIsUsed(bool Val) {
132    IsUsed = Val;
133  }
134
135  /// setIsAllowRedefinitionsWithoutWarning - Set the value of the
136  /// IsAllowRedefinitionsWithoutWarning flag.
137  void setIsAllowRedefinitionsWithoutWarning(bool Val) {
138    IsAllowRedefinitionsWithoutWarning = Val;
139  }
140
141  /// setArgumentList - Set the specified list of identifiers as the argument
142  /// list for this macro.
143  void setArgumentList(IdentifierInfo* const *List, unsigned NumArgs,
144                       llvm::BumpPtrAllocator &PPAllocator) {
145    assert(ArgumentList == 0 && NumArguments == 0 &&
146           "Argument list already set!");
147    if (NumArgs == 0) return;
148
149    NumArguments = NumArgs;
150    ArgumentList = PPAllocator.Allocate<IdentifierInfo*>(NumArgs);
151    for (unsigned i = 0; i != NumArgs; ++i)
152      ArgumentList[i] = List[i];
153  }
154
155  /// Arguments - The list of arguments for a function-like macro.  This can be
156  /// empty, for, e.g. "#define X()".
157  typedef IdentifierInfo* const *arg_iterator;
158  bool arg_empty() const { return NumArguments == 0; }
159  arg_iterator arg_begin() const { return ArgumentList; }
160  arg_iterator arg_end() const { return ArgumentList+NumArguments; }
161  unsigned getNumArgs() const { return NumArguments; }
162
163  /// getArgumentNum - Return the argument number of the specified identifier,
164  /// or -1 if the identifier is not a formal argument identifier.
165  int getArgumentNum(IdentifierInfo *Arg) const {
166    for (arg_iterator I = arg_begin(), E = arg_end(); I != E; ++I)
167      if (*I == Arg) return I-arg_begin();
168    return -1;
169  }
170
171  /// Function/Object-likeness.  Keep track of whether this macro has formal
172  /// parameters.
173  void setIsFunctionLike() { IsFunctionLike = true; }
174  bool isFunctionLike() const { return IsFunctionLike; }
175  bool isObjectLike() const { return !IsFunctionLike; }
176
177  /// Varargs querying methods.  This can only be set for function-like macros.
178  void setIsC99Varargs() { IsC99Varargs = true; }
179  void setIsGNUVarargs() { IsGNUVarargs = true; }
180  bool isC99Varargs() const { return IsC99Varargs; }
181  bool isGNUVarargs() const { return IsGNUVarargs; }
182  bool isVariadic() const { return IsC99Varargs | IsGNUVarargs; }
183
184  /// isBuiltinMacro - Return true if this macro is a builtin macro, such as
185  /// __LINE__, which requires processing before expansion.
186  bool isBuiltinMacro() const { return IsBuiltinMacro; }
187
188  /// isFromPCH - Return true if this macro was loaded from a PCH file.
189  bool isFromPCH() const { return IsFromPCH; }
190
191  /// setIsFromPCH - Set whether this macro was loaded from a PCH file.
192  void setIsFromPCH(bool FromPCH = true) { IsFromPCH = FromPCH; }
193
194  /// isUsed - Return false if this macro is defined in the main file and has
195  /// not yet been used.
196  bool isUsed() const { return IsUsed; }
197
198  /// isAllowRedefinitionsWithoutWarning - Return true if this macro can be
199  /// redefined without warning.
200  bool isAllowRedefinitionsWithoutWarning() const {
201    return IsAllowRedefinitionsWithoutWarning;
202  }
203
204  /// getNumTokens - Return the number of tokens that this macro expands to.
205  ///
206  unsigned getNumTokens() const {
207    return ReplacementTokens.size();
208  }
209
210  const Token &getReplacementToken(unsigned Tok) const {
211    assert(Tok < ReplacementTokens.size() && "Invalid token #");
212    return ReplacementTokens[Tok];
213  }
214
215  typedef llvm::SmallVector<Token, 8>::const_iterator tokens_iterator;
216  tokens_iterator tokens_begin() const { return ReplacementTokens.begin(); }
217  tokens_iterator tokens_end() const { return ReplacementTokens.end(); }
218  bool tokens_empty() const { return ReplacementTokens.empty(); }
219
220  /// AddTokenToBody - Add the specified token to the replacement text for the
221  /// macro.
222  void AddTokenToBody(const Token &Tok) {
223    ReplacementTokens.push_back(Tok);
224  }
225
226  /// isEnabled - Return true if this macro is enabled: in other words, that we
227  /// are not currently in an expansion of this macro.
228  bool isEnabled() const { return !IsDisabled; }
229
230  void EnableMacro() {
231    assert(IsDisabled && "Cannot enable an already-enabled macro!");
232    IsDisabled = false;
233  }
234
235  void DisableMacro() {
236    assert(!IsDisabled && "Cannot disable an already-disabled macro!");
237    IsDisabled = true;
238  }
239};
240
241}  // end namespace clang
242
243#endif
244