1//===--- Token.h - Token interface ------------------------------*- 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 Token interface.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CLANG_LEX_TOKEN_H
15#define LLVM_CLANG_LEX_TOKEN_H
16
17#include "clang/Basic/SourceLocation.h"
18#include "clang/Basic/TokenKinds.h"
19#include "llvm/ADT/StringRef.h"
20#include <cassert>
21
22namespace clang {
23
24class IdentifierInfo;
25
26/// Token - This structure provides full information about a lexed token.
27/// It is not intended to be space efficient, it is intended to return as much
28/// information as possible about each returned token.  This is expected to be
29/// compressed into a smaller form if memory footprint is important.
30///
31/// The parser can create a special "annotation token" representing a stream of
32/// tokens that were parsed and semantically resolved, e.g.: "foo::MyClass<int>"
33/// can be represented by a single typename annotation token that carries
34/// information about the SourceRange of the tokens and the type object.
35class Token {
36  /// The location of the token. This is actually a SourceLocation.
37  unsigned Loc;
38
39  // Conceptually these next two fields could be in a union.  However, this
40  // causes gcc 4.2 to pessimize LexTokenInternal, a very performance critical
41  // routine. Keeping as separate members with casts until a more beautiful fix
42  // presents itself.
43
44  /// UintData - This holds either the length of the token text, when
45  /// a normal token, or the end of the SourceRange when an annotation
46  /// token.
47  unsigned UintData;
48
49  /// PtrData - This is a union of four different pointer types, which depends
50  /// on what type of token this is:
51  ///  Identifiers, keywords, etc:
52  ///    This is an IdentifierInfo*, which contains the uniqued identifier
53  ///    spelling.
54  ///  Literals:  isLiteral() returns true.
55  ///    This is a pointer to the start of the token in a text buffer, which
56  ///    may be dirty (have trigraphs / escaped newlines).
57  ///  Annotations (resolved type names, C++ scopes, etc): isAnnotation().
58  ///    This is a pointer to sema-specific data for the annotation token.
59  ///  Eof:
60  //     This is a pointer to a Decl.
61  ///  Other:
62  ///    This is null.
63  void *PtrData;
64
65  /// Kind - The actual flavor of token this is.
66  tok::TokenKind Kind;
67
68  /// Flags - Bits we track about this token, members of the TokenFlags enum.
69  unsigned short Flags;
70
71public:
72  // Various flags set per token:
73  enum TokenFlags {
74    StartOfLine   = 0x01,  // At start of line or only after whitespace
75                           // (considering the line after macro expansion).
76    LeadingSpace  = 0x02,  // Whitespace exists before this token (considering
77                           // whitespace after macro expansion).
78    DisableExpand = 0x04,  // This identifier may never be macro expanded.
79    NeedsCleaning = 0x08,  // Contained an escaped newline or trigraph.
80    LeadingEmptyMacro = 0x10, // Empty macro exists before this token.
81    HasUDSuffix = 0x20,    // This string or character literal has a ud-suffix.
82    HasUCN = 0x40,         // This identifier contains a UCN.
83    IgnoredComma = 0x80,   // This comma is not a macro argument separator (MS).
84    StringifiedInMacro = 0x100, // This string or character literal is formed by
85                                // macro stringizing or charizing operator.
86    CommaAfterElided = 0x200, // The comma following this token was elided (MS).
87  };
88
89  tok::TokenKind getKind() const { return Kind; }
90  void setKind(tok::TokenKind K) { Kind = K; }
91
92  /// is/isNot - Predicates to check if this token is a specific kind, as in
93  /// "if (Tok.is(tok::l_brace)) {...}".
94  bool is(tok::TokenKind K) const { return Kind == K; }
95  bool isNot(tok::TokenKind K) const { return Kind != K; }
96  bool isOneOf(tok::TokenKind K1, tok::TokenKind K2) const {
97    return is(K1) || is(K2);
98  }
99  template <typename... Ts>
100  bool isOneOf(tok::TokenKind K1, tok::TokenKind K2, Ts... Ks) const {
101    return is(K1) || isOneOf(K2, Ks...);
102  }
103
104  /// \brief Return true if this is a raw identifier (when lexing
105  /// in raw mode) or a non-keyword identifier (when lexing in non-raw mode).
106  bool isAnyIdentifier() const {
107    return tok::isAnyIdentifier(getKind());
108  }
109
110  /// \brief Return true if this is a "literal", like a numeric
111  /// constant, string, etc.
112  bool isLiteral() const {
113    return tok::isLiteral(getKind());
114  }
115
116  /// \brief Return true if this is any of tok::annot_* kind tokens.
117  bool isAnnotation() const {
118    return tok::isAnnotation(getKind());
119  }
120
121  /// \brief Return a source location identifier for the specified
122  /// offset in the current file.
123  SourceLocation getLocation() const {
124    return SourceLocation::getFromRawEncoding(Loc);
125  }
126  unsigned getLength() const {
127    assert(!isAnnotation() && "Annotation tokens have no length field");
128    return UintData;
129  }
130
131  void setLocation(SourceLocation L) { Loc = L.getRawEncoding(); }
132  void setLength(unsigned Len) {
133    assert(!isAnnotation() && "Annotation tokens have no length field");
134    UintData = Len;
135  }
136
137  SourceLocation getAnnotationEndLoc() const {
138    assert(isAnnotation() && "Used AnnotEndLocID on non-annotation token");
139    return SourceLocation::getFromRawEncoding(UintData ? UintData : Loc);
140  }
141  void setAnnotationEndLoc(SourceLocation L) {
142    assert(isAnnotation() && "Used AnnotEndLocID on non-annotation token");
143    UintData = L.getRawEncoding();
144  }
145
146  SourceLocation getLastLoc() const {
147    return isAnnotation() ? getAnnotationEndLoc() : getLocation();
148  }
149
150  SourceLocation getEndLoc() const {
151    return isAnnotation() ? getAnnotationEndLoc()
152                          : getLocation().getLocWithOffset(getLength());
153  }
154
155  /// \brief SourceRange of the group of tokens that this annotation token
156  /// represents.
157  SourceRange getAnnotationRange() const {
158    return SourceRange(getLocation(), getAnnotationEndLoc());
159  }
160  void setAnnotationRange(SourceRange R) {
161    setLocation(R.getBegin());
162    setAnnotationEndLoc(R.getEnd());
163  }
164
165  const char *getName() const { return tok::getTokenName(Kind); }
166
167  /// \brief Reset all flags to cleared.
168  void startToken() {
169    Kind = tok::unknown;
170    Flags = 0;
171    PtrData = nullptr;
172    UintData = 0;
173    Loc = SourceLocation().getRawEncoding();
174  }
175
176  IdentifierInfo *getIdentifierInfo() const {
177    assert(isNot(tok::raw_identifier) &&
178           "getIdentifierInfo() on a tok::raw_identifier token!");
179    assert(!isAnnotation() &&
180           "getIdentifierInfo() on an annotation token!");
181    if (isLiteral()) return nullptr;
182    if (is(tok::eof)) return nullptr;
183    return (IdentifierInfo*) PtrData;
184  }
185  void setIdentifierInfo(IdentifierInfo *II) {
186    PtrData = (void*) II;
187  }
188
189  const void *getEofData() const {
190    assert(is(tok::eof));
191    return reinterpret_cast<const void *>(PtrData);
192  }
193  void setEofData(const void *D) {
194    assert(is(tok::eof));
195    assert(!PtrData);
196    PtrData = const_cast<void *>(D);
197  }
198
199  /// getRawIdentifier - For a raw identifier token (i.e., an identifier
200  /// lexed in raw mode), returns a reference to the text substring in the
201  /// buffer if known.
202  StringRef getRawIdentifier() const {
203    assert(is(tok::raw_identifier));
204    return StringRef(reinterpret_cast<const char *>(PtrData), getLength());
205  }
206  void setRawIdentifierData(const char *Ptr) {
207    assert(is(tok::raw_identifier));
208    PtrData = const_cast<char*>(Ptr);
209  }
210
211  /// getLiteralData - For a literal token (numeric constant, string, etc), this
212  /// returns a pointer to the start of it in the text buffer if known, null
213  /// otherwise.
214  const char *getLiteralData() const {
215    assert(isLiteral() && "Cannot get literal data of non-literal");
216    return reinterpret_cast<const char*>(PtrData);
217  }
218  void setLiteralData(const char *Ptr) {
219    assert(isLiteral() && "Cannot set literal data of non-literal");
220    PtrData = const_cast<char*>(Ptr);
221  }
222
223  void *getAnnotationValue() const {
224    assert(isAnnotation() && "Used AnnotVal on non-annotation token");
225    return PtrData;
226  }
227  void setAnnotationValue(void *val) {
228    assert(isAnnotation() && "Used AnnotVal on non-annotation token");
229    PtrData = val;
230  }
231
232  /// \brief Set the specified flag.
233  void setFlag(TokenFlags Flag) {
234    Flags |= Flag;
235  }
236
237  /// \brief Get the specified flag.
238  bool getFlag(TokenFlags Flag) const {
239    return (Flags & Flag) != 0;
240  }
241
242  /// \brief Unset the specified flag.
243  void clearFlag(TokenFlags Flag) {
244    Flags &= ~Flag;
245  }
246
247  /// \brief Return the internal represtation of the flags.
248  ///
249  /// This is only intended for low-level operations such as writing tokens to
250  /// disk.
251  unsigned getFlags() const {
252    return Flags;
253  }
254
255  /// \brief Set a flag to either true or false.
256  void setFlagValue(TokenFlags Flag, bool Val) {
257    if (Val)
258      setFlag(Flag);
259    else
260      clearFlag(Flag);
261  }
262
263  /// isAtStartOfLine - Return true if this token is at the start of a line.
264  ///
265  bool isAtStartOfLine() const { return getFlag(StartOfLine); }
266
267  /// \brief Return true if this token has whitespace before it.
268  ///
269  bool hasLeadingSpace() const { return getFlag(LeadingSpace); }
270
271  /// \brief Return true if this identifier token should never
272  /// be expanded in the future, due to C99 6.10.3.4p2.
273  bool isExpandDisabled() const { return getFlag(DisableExpand); }
274
275  /// \brief Return true if we have an ObjC keyword identifier.
276  bool isObjCAtKeyword(tok::ObjCKeywordKind objcKey) const;
277
278  /// \brief Return the ObjC keyword kind.
279  tok::ObjCKeywordKind getObjCKeywordID() const;
280
281  /// \brief Return true if this token has trigraphs or escaped newlines in it.
282  bool needsCleaning() const { return getFlag(NeedsCleaning); }
283
284  /// \brief Return true if this token has an empty macro before it.
285  ///
286  bool hasLeadingEmptyMacro() const { return getFlag(LeadingEmptyMacro); }
287
288  /// \brief Return true if this token is a string or character literal which
289  /// has a ud-suffix.
290  bool hasUDSuffix() const { return getFlag(HasUDSuffix); }
291
292  /// Returns true if this token contains a universal character name.
293  bool hasUCN() const { return getFlag(HasUCN); }
294
295  /// Returns true if this token is formed by macro by stringizing or charizing
296  /// operator.
297  bool stringifiedInMacro() const { return getFlag(StringifiedInMacro); }
298
299  /// Returns true if the comma after this token was elided.
300  bool commaAfterElided() const { return getFlag(CommaAfterElided); }
301};
302
303/// \brief Information about the conditional stack (\#if directives)
304/// currently active.
305struct PPConditionalInfo {
306  /// \brief Location where the conditional started.
307  SourceLocation IfLoc;
308
309  /// \brief True if this was contained in a skipping directive, e.g.,
310  /// in a "\#if 0" block.
311  bool WasSkipping;
312
313  /// \brief True if we have emitted tokens already, and now we're in
314  /// an \#else block or something.  Only useful in Skipping blocks.
315  bool FoundNonSkip;
316
317  /// \brief True if we've seen a \#else in this block.  If so,
318  /// \#elif/\#else directives are not allowed.
319  bool FoundElse;
320};
321
322} // end namespace clang
323
324namespace llvm {
325  template <>
326  struct isPodLike<clang::Token> { static const bool value = true; };
327} // end namespace llvm
328
329#endif // LLVM_CLANG_LEX_TOKEN_H
330