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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     HasUDSuffix = 0x20, // This string or character literal has a ud-suffix.
80     IgnoredComma = 0x40 // Flags ignored commas from nested macro expansions.
81   };
82 
getKind()83   tok::TokenKind getKind() const { return (tok::TokenKind)Kind; }
setKind(tok::TokenKind K)84   void setKind(tok::TokenKind K) { Kind = K; }
85 
86   /// is/isNot - Predicates to check if this token is a specific kind, as in
87   /// "if (Tok.is(tok::l_brace)) {...}".
is(tok::TokenKind K)88   bool is(tok::TokenKind K) const { return Kind == (unsigned) K; }
isNot(tok::TokenKind K)89   bool isNot(tok::TokenKind K) const { return Kind != (unsigned) K; }
90 
91   /// \brief Return true if this is a raw identifier (when lexing
92   /// in raw mode) or a non-keyword identifier (when lexing in non-raw mode).
isAnyIdentifier()93   bool isAnyIdentifier() const {
94     return is(tok::identifier) || is(tok::raw_identifier);
95   }
96 
97   /// isLiteral - Return true if this is a "literal", like a numeric
98   /// constant, string, etc.
isLiteral()99   bool isLiteral() const {
100     return is(tok::numeric_constant) || is(tok::char_constant) ||
101            is(tok::wide_char_constant) || is(tok::utf16_char_constant) ||
102            is(tok::utf32_char_constant) || is(tok::string_literal) ||
103            is(tok::wide_string_literal) || is(tok::utf8_string_literal) ||
104            is(tok::utf16_string_literal) || is(tok::utf32_string_literal) ||
105            is(tok::angle_string_literal);
106   }
107 
isAnnotation()108   bool isAnnotation() const {
109 #define ANNOTATION(NAME) \
110     if (is(tok::annot_##NAME)) \
111       return true;
112 #include "clang/Basic/TokenKinds.def"
113     return false;
114   }
115 
116   /// \brief Return a source location identifier for the specified
117   /// offset in the current file.
getLocation()118   SourceLocation getLocation() const { return Loc; }
getLength()119   unsigned getLength() const {
120     assert(!isAnnotation() && "Annotation tokens have no length field");
121     return UintData;
122   }
123 
setLocation(SourceLocation L)124   void setLocation(SourceLocation L) { Loc = L; }
setLength(unsigned Len)125   void setLength(unsigned Len) {
126     assert(!isAnnotation() && "Annotation tokens have no length field");
127     UintData = Len;
128   }
129 
getAnnotationEndLoc()130   SourceLocation getAnnotationEndLoc() const {
131     assert(isAnnotation() && "Used AnnotEndLocID on non-annotation token");
132     return SourceLocation::getFromRawEncoding(UintData);
133   }
setAnnotationEndLoc(SourceLocation L)134   void setAnnotationEndLoc(SourceLocation L) {
135     assert(isAnnotation() && "Used AnnotEndLocID on non-annotation token");
136     UintData = L.getRawEncoding();
137   }
138 
getLastLoc()139   SourceLocation getLastLoc() const {
140     return isAnnotation() ? getAnnotationEndLoc() : getLocation();
141   }
142 
143   /// \brief SourceRange of the group of tokens that this annotation token
144   /// represents.
getAnnotationRange()145   SourceRange getAnnotationRange() const {
146     return SourceRange(getLocation(), getAnnotationEndLoc());
147   }
setAnnotationRange(SourceRange R)148   void setAnnotationRange(SourceRange R) {
149     setLocation(R.getBegin());
150     setAnnotationEndLoc(R.getEnd());
151   }
152 
getName()153   const char *getName() const {
154     return tok::getTokenName( (tok::TokenKind) Kind);
155   }
156 
157   /// \brief Reset all flags to cleared.
startToken()158   void startToken() {
159     Kind = tok::unknown;
160     Flags = 0;
161     PtrData = 0;
162     UintData = 0;
163     Loc = SourceLocation();
164   }
165 
getIdentifierInfo()166   IdentifierInfo *getIdentifierInfo() const {
167     assert(isNot(tok::raw_identifier) &&
168            "getIdentifierInfo() on a tok::raw_identifier token!");
169     assert(!isAnnotation() &&
170            "getIdentifierInfo() on an annotation token!");
171     if (isLiteral()) return 0;
172     return (IdentifierInfo*) PtrData;
173   }
setIdentifierInfo(IdentifierInfo * II)174   void setIdentifierInfo(IdentifierInfo *II) {
175     PtrData = (void*) II;
176   }
177 
178   /// getRawIdentifierData - For a raw identifier token (i.e., an identifier
179   /// lexed in raw mode), returns a pointer to the start of it in the text
180   /// buffer if known, null otherwise.
getRawIdentifierData()181   const char *getRawIdentifierData() const {
182     assert(is(tok::raw_identifier));
183     return reinterpret_cast<const char*>(PtrData);
184   }
setRawIdentifierData(const char * Ptr)185   void setRawIdentifierData(const char *Ptr) {
186     assert(is(tok::raw_identifier));
187     PtrData = const_cast<char*>(Ptr);
188   }
189 
190   /// getLiteralData - For a literal token (numeric constant, string, etc), this
191   /// returns a pointer to the start of it in the text buffer if known, null
192   /// otherwise.
getLiteralData()193   const char *getLiteralData() const {
194     assert(isLiteral() && "Cannot get literal data of non-literal");
195     return reinterpret_cast<const char*>(PtrData);
196   }
setLiteralData(const char * Ptr)197   void setLiteralData(const char *Ptr) {
198     assert(isLiteral() && "Cannot set literal data of non-literal");
199     PtrData = const_cast<char*>(Ptr);
200   }
201 
getAnnotationValue()202   void *getAnnotationValue() const {
203     assert(isAnnotation() && "Used AnnotVal on non-annotation token");
204     return PtrData;
205   }
setAnnotationValue(void * val)206   void setAnnotationValue(void *val) {
207     assert(isAnnotation() && "Used AnnotVal on non-annotation token");
208     PtrData = val;
209   }
210 
211   /// \brief Set the specified flag.
setFlag(TokenFlags Flag)212   void setFlag(TokenFlags Flag) {
213     Flags |= Flag;
214   }
215 
216   /// \brief Unset the specified flag.
clearFlag(TokenFlags Flag)217   void clearFlag(TokenFlags Flag) {
218     Flags &= ~Flag;
219   }
220 
221   /// \brief Return the internal represtation of the flags.
222   ///
223   /// This is only intended for low-level operations such as writing tokens to
224   /// disk.
getFlags()225   unsigned getFlags() const {
226     return Flags;
227   }
228 
229   /// \brief Set a flag to either true or false.
setFlagValue(TokenFlags Flag,bool Val)230   void setFlagValue(TokenFlags Flag, bool Val) {
231     if (Val)
232       setFlag(Flag);
233     else
234       clearFlag(Flag);
235   }
236 
237   /// isAtStartOfLine - Return true if this token is at the start of a line.
238   ///
isAtStartOfLine()239   bool isAtStartOfLine() const { return (Flags & StartOfLine) ? true : false; }
240 
241   /// \brief Return true if this token has whitespace before it.
242   ///
hasLeadingSpace()243   bool hasLeadingSpace() const { return (Flags & LeadingSpace) ? true : false; }
244 
245   /// \brief Return true if this identifier token should never
246   /// be expanded in the future, due to C99 6.10.3.4p2.
isExpandDisabled()247   bool isExpandDisabled() const {
248     return (Flags & DisableExpand) ? true : false;
249   }
250 
251   /// \brief Return true if we have an ObjC keyword identifier.
252   bool isObjCAtKeyword(tok::ObjCKeywordKind objcKey) const;
253 
254   /// \brief Return the ObjC keyword kind.
255   tok::ObjCKeywordKind getObjCKeywordID() const;
256 
257   /// \brief Return true if this token has trigraphs or escaped newlines in it.
needsCleaning()258   bool needsCleaning() const { return (Flags & NeedsCleaning) ? true : false; }
259 
260   /// \brief Return true if this token has an empty macro before it.
261   ///
hasLeadingEmptyMacro()262   bool hasLeadingEmptyMacro() const {
263     return (Flags & LeadingEmptyMacro) ? true : false;
264   }
265 
266   /// \brief Return true if this token is a string or character literal which
267   /// has a ud-suffix.
hasUDSuffix()268   bool hasUDSuffix() const { return (Flags & HasUDSuffix) ? true : false; }
269 };
270 
271 /// \brief Information about the conditional stack (\#if directives)
272 /// currently active.
273 struct PPConditionalInfo {
274   /// \brief Location where the conditional started.
275   SourceLocation IfLoc;
276 
277   /// \brief True if this was contained in a skipping directive, e.g.,
278   /// in a "\#if 0" block.
279   bool WasSkipping;
280 
281   /// \brief True if we have emitted tokens already, and now we're in
282   /// an \#else block or something.  Only useful in Skipping blocks.
283   bool FoundNonSkip;
284 
285   /// \brief True if we've seen a \#else in this block.  If so,
286   /// \#elif/\#else directives are not allowed.
287   bool FoundElse;
288 };
289 
290 }  // end namespace clang
291 
292 namespace llvm {
293   template <>
294   struct isPodLike<clang::Token> { static const bool value = true; };
295 }  // end namespace llvm
296 
297 #endif
298