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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_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 <cstdlib>
22 
23 namespace clang {
24 
25 class IdentifierInfo;
26 
27 /// Token - This structure provides full information about a lexed token.
28 /// It is not intended to be space efficient, it is intended to return as much
29 /// information as possible about each returned token.  This is expected to be
30 /// compressed into a smaller form if memory footprint is important.
31 ///
32 /// The parser can create a special "annotation token" representing a stream of
33 /// tokens that were parsed and semantically resolved, e.g.: "foo::MyClass<int>"
34 /// can be represented by a single typename annotation token that carries
35 /// information about the SourceRange of the tokens and the type object.
36 class Token {
37   /// The location of the token.
38   SourceLocation Loc;
39 
40   // Conceptually these next two fields could be in a union.  However, this
41   // causes gcc 4.2 to pessimize LexTokenInternal, a very performance critical
42   // routine. Keeping as separate members with casts until a more beautiful fix
43   // presents itself.
44 
45   /// UintData - This holds either the length of the token text, when
46   /// a normal token, or the end of the SourceRange when an annotation
47   /// token.
48   unsigned UintData;
49 
50   /// PtrData - This is a union of four different pointer types, which depends
51   /// on what type of token this is:
52   ///  Identifiers, keywords, etc:
53   ///    This is an IdentifierInfo*, which contains the uniqued identifier
54   ///    spelling.
55   ///  Literals:  isLiteral() returns true.
56   ///    This is a pointer to the start of the token in a text buffer, which
57   ///    may be dirty (have trigraphs / escaped newlines).
58   ///  Annotations (resolved type names, C++ scopes, etc): isAnnotation().
59   ///    This is a pointer to sema-specific data for the annotation token.
60   ///  Other:
61   ///    This is null.
62   void *PtrData;
63 
64   /// Kind - The actual flavor of token this is.
65   ///
66   unsigned short Kind;
67 
68   /// Flags - Bits we track about this token, members of the TokenFlags enum.
69   unsigned char Flags;
70 public:
71 
72   // Various flags set per token:
73   enum TokenFlags {
74     StartOfLine   = 0x01,  // At start of line or only after whitespace.
75     LeadingSpace  = 0x02,  // Whitespace exists before this token.
76     DisableExpand = 0x04,  // This identifier may never be macro expanded.
77     NeedsCleaning = 0x08,  // Contained an escaped newline or trigraph.
78     LeadingEmptyMacro = 0x10, // Empty macro exists before this token.
79     HasUDSuffix = 0x20,    // This string or character literal has a ud-suffix.
80     HasUCN = 0x40,         // This identifier contains a UCN.
81     IgnoredComma = 0x80    // This comma is not a macro argument separator (MS).
82   };
83 
getKind()84   tok::TokenKind getKind() const { return (tok::TokenKind)Kind; }
setKind(tok::TokenKind K)85   void setKind(tok::TokenKind K) { Kind = K; }
86 
87   /// is/isNot - Predicates to check if this token is a specific kind, as in
88   /// "if (Tok.is(tok::l_brace)) {...}".
is(tok::TokenKind K)89   bool is(tok::TokenKind K) const { return Kind == (unsigned) K; }
isNot(tok::TokenKind K)90   bool isNot(tok::TokenKind K) const { return Kind != (unsigned) K; }
91 
92   /// \brief Return true if this is a raw identifier (when lexing
93   /// in raw mode) or a non-keyword identifier (when lexing in non-raw mode).
isAnyIdentifier()94   bool isAnyIdentifier() const {
95     return tok::isAnyIdentifier(getKind());
96   }
97 
98   /// \brief Return true if this is a "literal", like a numeric
99   /// constant, string, etc.
isLiteral()100   bool isLiteral() const {
101     return tok::isLiteral(getKind());
102   }
103 
104   /// \brief Return true if this is any of tok::annot_* kind tokens.
isAnnotation()105   bool isAnnotation() const {
106     return tok::isAnnotation(getKind());
107   }
108 
109   /// \brief Return a source location identifier for the specified
110   /// offset in the current file.
getLocation()111   SourceLocation getLocation() const { return Loc; }
getLength()112   unsigned getLength() const {
113     assert(!isAnnotation() && "Annotation tokens have no length field");
114     return UintData;
115   }
116 
setLocation(SourceLocation L)117   void setLocation(SourceLocation L) { Loc = L; }
setLength(unsigned Len)118   void setLength(unsigned Len) {
119     assert(!isAnnotation() && "Annotation tokens have no length field");
120     UintData = Len;
121   }
122 
getAnnotationEndLoc()123   SourceLocation getAnnotationEndLoc() const {
124     assert(isAnnotation() && "Used AnnotEndLocID on non-annotation token");
125     return SourceLocation::getFromRawEncoding(UintData);
126   }
setAnnotationEndLoc(SourceLocation L)127   void setAnnotationEndLoc(SourceLocation L) {
128     assert(isAnnotation() && "Used AnnotEndLocID on non-annotation token");
129     UintData = L.getRawEncoding();
130   }
131 
getLastLoc()132   SourceLocation getLastLoc() const {
133     return isAnnotation() ? getAnnotationEndLoc() : getLocation();
134   }
135 
136   /// \brief SourceRange of the group of tokens that this annotation token
137   /// represents.
getAnnotationRange()138   SourceRange getAnnotationRange() const {
139     return SourceRange(getLocation(), getAnnotationEndLoc());
140   }
setAnnotationRange(SourceRange R)141   void setAnnotationRange(SourceRange R) {
142     setLocation(R.getBegin());
143     setAnnotationEndLoc(R.getEnd());
144   }
145 
getName()146   const char *getName() const {
147     return tok::getTokenName( (tok::TokenKind) Kind);
148   }
149 
150   /// \brief Reset all flags to cleared.
startToken()151   void startToken() {
152     Kind = tok::unknown;
153     Flags = 0;
154     PtrData = 0;
155     UintData = 0;
156     Loc = SourceLocation();
157   }
158 
getIdentifierInfo()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 0;
165     return (IdentifierInfo*) PtrData;
166   }
setIdentifierInfo(IdentifierInfo * II)167   void setIdentifierInfo(IdentifierInfo *II) {
168     PtrData = (void*) II;
169   }
170 
171   /// getRawIdentifierData - For a raw identifier token (i.e., an identifier
172   /// lexed in raw mode), returns a pointer to the start of it in the text
173   /// buffer if known, null otherwise.
getRawIdentifierData()174   const char *getRawIdentifierData() const {
175     assert(is(tok::raw_identifier));
176     return reinterpret_cast<const char*>(PtrData);
177   }
setRawIdentifierData(const char * Ptr)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.
getLiteralData()186   const char *getLiteralData() const {
187     assert(isLiteral() && "Cannot get literal data of non-literal");
188     return reinterpret_cast<const char*>(PtrData);
189   }
setLiteralData(const char * Ptr)190   void setLiteralData(const char *Ptr) {
191     assert(isLiteral() && "Cannot set literal data of non-literal");
192     PtrData = const_cast<char*>(Ptr);
193   }
194 
getAnnotationValue()195   void *getAnnotationValue() const {
196     assert(isAnnotation() && "Used AnnotVal on non-annotation token");
197     return PtrData;
198   }
setAnnotationValue(void * val)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.
setFlag(TokenFlags Flag)205   void setFlag(TokenFlags Flag) {
206     Flags |= Flag;
207   }
208 
209   /// \brief Unset the specified flag.
clearFlag(TokenFlags 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.
getFlags()218   unsigned getFlags() const {
219     return Flags;
220   }
221 
222   /// \brief Set a flag to either true or false.
setFlagValue(TokenFlags Flag,bool Val)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   ///
isAtStartOfLine()232   bool isAtStartOfLine() const { return (Flags & StartOfLine) ? true : false; }
233 
234   /// \brief Return true if this token has whitespace before it.
235   ///
hasLeadingSpace()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.
isExpandDisabled()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.
needsCleaning()251   bool needsCleaning() const { return (Flags & NeedsCleaning) ? true : false; }
252 
253   /// \brief Return true if this token has an empty macro before it.
254   ///
hasLeadingEmptyMacro()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.
hasUDSuffix()261   bool hasUDSuffix() const { return (Flags & HasUDSuffix) ? true : false; }
262 
263   /// Returns true if this token contains a universal character name.
hasUCN()264   bool hasUCN() const { return (Flags & HasUCN) ? true : false; }
265 };
266 
267 /// \brief Information about the conditional stack (\#if directives)
268 /// currently active.
269 struct 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 
288 namespace llvm {
289   template <>
290   struct isPodLike<clang::Token> { static const bool value = true; };
291 }  // end namespace llvm
292 
293 #endif
294