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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/TemplateKinds.h"
18 #include "clang/Basic/TokenKinds.h"
19 #include "clang/Basic/SourceLocation.h"
20 #include "clang/Basic/OperatorKinds.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   };
80 
getKind()81   tok::TokenKind getKind() const { return (tok::TokenKind)Kind; }
setKind(tok::TokenKind K)82   void setKind(tok::TokenKind K) { Kind = K; }
83 
84   /// is/isNot - Predicates to check if this token is a specific kind, as in
85   /// "if (Tok.is(tok::l_brace)) {...}".
is(tok::TokenKind K)86   bool is(tok::TokenKind K) const { return Kind == (unsigned) K; }
isNot(tok::TokenKind K)87   bool isNot(tok::TokenKind K) const { return Kind != (unsigned) K; }
88 
89   /// isAnyIdentifier - Return true if this is a raw identifier (when lexing
90   /// in raw mode) or a non-keyword identifier (when lexing in non-raw mode).
isAnyIdentifier()91   bool isAnyIdentifier() const {
92     return is(tok::identifier) || is(tok::raw_identifier);
93   }
94 
95   /// isLiteral - Return true if this is a "literal", like a numeric
96   /// constant, string, etc.
isLiteral()97   bool isLiteral() const {
98     return is(tok::numeric_constant) || is(tok::char_constant) ||
99            is(tok::string_literal) || is(tok::wide_string_literal) ||
100            is(tok::angle_string_literal);
101   }
102 
isAnnotation()103   bool isAnnotation() const {
104 #define ANNOTATION(NAME) \
105     if (is(tok::annot_##NAME)) \
106       return true;
107 #include "clang/Basic/TokenKinds.def"
108     return false;
109   }
110 
111   /// getLocation - Return a source location identifier for the specified
112   /// offset in the current file.
getLocation()113   SourceLocation getLocation() const { return Loc; }
getLength()114   unsigned getLength() const {
115     assert(!isAnnotation() && "Annotation tokens have no length field");
116     return UintData;
117   }
118 
setLocation(SourceLocation L)119   void setLocation(SourceLocation L) { Loc = L; }
setLength(unsigned Len)120   void setLength(unsigned Len) {
121     assert(!isAnnotation() && "Annotation tokens have no length field");
122     UintData = Len;
123   }
124 
getAnnotationEndLoc()125   SourceLocation getAnnotationEndLoc() const {
126     assert(isAnnotation() && "Used AnnotEndLocID on non-annotation token");
127     return SourceLocation::getFromRawEncoding(UintData);
128   }
setAnnotationEndLoc(SourceLocation L)129   void setAnnotationEndLoc(SourceLocation L) {
130     assert(isAnnotation() && "Used AnnotEndLocID on non-annotation token");
131     UintData = L.getRawEncoding();
132   }
133 
getLastLoc()134   SourceLocation getLastLoc() const {
135     return isAnnotation() ? getAnnotationEndLoc() : getLocation();
136   }
137 
138   /// getAnnotationRange - SourceRange of the group of tokens that this
139   /// annotation token represents.
getAnnotationRange()140   SourceRange getAnnotationRange() const {
141     return SourceRange(getLocation(), getAnnotationEndLoc());
142   }
setAnnotationRange(SourceRange R)143   void setAnnotationRange(SourceRange R) {
144     setLocation(R.getBegin());
145     setAnnotationEndLoc(R.getEnd());
146   }
147 
getName()148   const char *getName() const {
149     return tok::getTokenName( (tok::TokenKind) Kind);
150   }
151 
152   /// startToken - Reset all flags to cleared.
153   ///
startToken()154   void startToken() {
155     Kind = tok::unknown;
156     Flags = 0;
157     PtrData = 0;
158     UintData = 0;
159     Loc = SourceLocation();
160   }
161 
getIdentifierInfo()162   IdentifierInfo *getIdentifierInfo() const {
163     assert(isNot(tok::raw_identifier) &&
164            "getIdentifierInfo() on a tok::raw_identifier token!");
165     assert(!isAnnotation() &&
166            "getIdentifierInfo() on an annotation token!");
167     if (isLiteral()) return 0;
168     return (IdentifierInfo*) PtrData;
169   }
setIdentifierInfo(IdentifierInfo * II)170   void setIdentifierInfo(IdentifierInfo *II) {
171     PtrData = (void*) II;
172   }
173 
174   /// getRawIdentifierData - For a raw identifier token (i.e., an identifier
175   /// lexed in raw mode), returns a pointer to the start of it in the text
176   /// buffer if known, null otherwise.
getRawIdentifierData()177   const char *getRawIdentifierData() const {
178     assert(is(tok::raw_identifier));
179     return reinterpret_cast<const char*>(PtrData);
180   }
setRawIdentifierData(const char * Ptr)181   void setRawIdentifierData(const char *Ptr) {
182     assert(is(tok::raw_identifier));
183     PtrData = const_cast<char*>(Ptr);
184   }
185 
186   /// getLiteralData - For a literal token (numeric constant, string, etc), this
187   /// returns a pointer to the start of it in the text buffer if known, null
188   /// otherwise.
getLiteralData()189   const char *getLiteralData() const {
190     assert(isLiteral() && "Cannot get literal data of non-literal");
191     return reinterpret_cast<const char*>(PtrData);
192   }
setLiteralData(const char * Ptr)193   void setLiteralData(const char *Ptr) {
194     assert(isLiteral() && "Cannot set literal data of non-literal");
195     PtrData = const_cast<char*>(Ptr);
196   }
197 
getAnnotationValue()198   void *getAnnotationValue() const {
199     assert(isAnnotation() && "Used AnnotVal on non-annotation token");
200     return PtrData;
201   }
setAnnotationValue(void * val)202   void setAnnotationValue(void *val) {
203     assert(isAnnotation() && "Used AnnotVal on non-annotation token");
204     PtrData = val;
205   }
206 
207   /// setFlag - Set the specified flag.
setFlag(TokenFlags Flag)208   void setFlag(TokenFlags Flag) {
209     Flags |= Flag;
210   }
211 
212   /// clearFlag - Unset the specified flag.
clearFlag(TokenFlags Flag)213   void clearFlag(TokenFlags Flag) {
214     Flags &= ~Flag;
215   }
216 
217   /// getFlags - Return the internal represtation of the flags.
218   ///  Only intended for low-level operations such as writing tokens to
219   //   disk.
getFlags()220   unsigned getFlags() const {
221     return Flags;
222   }
223 
224   /// setFlagValue - Set a flag to either true or false.
setFlagValue(TokenFlags Flag,bool Val)225   void setFlagValue(TokenFlags Flag, bool Val) {
226     if (Val)
227       setFlag(Flag);
228     else
229       clearFlag(Flag);
230   }
231 
232   /// isAtStartOfLine - Return true if this token is at the start of a line.
233   ///
isAtStartOfLine()234   bool isAtStartOfLine() const { return (Flags & StartOfLine) ? true : false; }
235 
236   /// hasLeadingSpace - Return true if this token has whitespace before it.
237   ///
hasLeadingSpace()238   bool hasLeadingSpace() const { return (Flags & LeadingSpace) ? true : false; }
239 
240   /// isExpandDisabled - Return true if this identifier token should never
241   /// be expanded in the future, due to C99 6.10.3.4p2.
isExpandDisabled()242   bool isExpandDisabled() const {
243     return (Flags & DisableExpand) ? true : false;
244   }
245 
246   /// isObjCAtKeyword - Return true if we have an ObjC keyword identifier.
247   bool isObjCAtKeyword(tok::ObjCKeywordKind objcKey) const;
248 
249   /// getObjCKeywordID - Return the ObjC keyword kind.
250   tok::ObjCKeywordKind getObjCKeywordID() const;
251 
252   /// needsCleaning - Return true if this token has trigraphs or escaped
253   /// newlines in it.
254   ///
needsCleaning()255   bool needsCleaning() const { return (Flags & NeedsCleaning) ? true : false; }
256 
257   /// \brief Return true if this token has an empty macro before it.
258   ///
hasLeadingEmptyMacro()259   bool hasLeadingEmptyMacro() const {
260     return (Flags & LeadingEmptyMacro) ? true : false;
261   }
262 
263 };
264 
265 /// PPConditionalInfo - Information about the conditional stack (#if directives)
266 /// currently active.
267 struct PPConditionalInfo {
268   /// IfLoc - Location where the conditional started.
269   ///
270   SourceLocation IfLoc;
271 
272   /// WasSkipping - True if this was contained in a skipping directive, e.g.
273   /// in a "#if 0" block.
274   bool WasSkipping;
275 
276   /// FoundNonSkip - True if we have emitted tokens already, and now we're in
277   /// an #else block or something.  Only useful in Skipping blocks.
278   bool FoundNonSkip;
279 
280   /// FoundElse - True if we've seen a #else in this block.  If so,
281   /// #elif/#else directives are not allowed.
282   bool FoundElse;
283 };
284 
285 }  // end namespace clang
286 
287 namespace llvm {
288   template <>
289   struct isPodLike<clang::Token> { static const bool value = true; };
290 }  // end namespace llvm
291 
292 #endif
293