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