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