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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   };
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 tok::isAnyIdentifier(getKind());
95   }
96 
97   /// \brief Return true if this is a "literal", like a numeric
98   /// constant, string, etc.
isLiteral()99   bool isLiteral() const {
100     return tok::isLiteral(getKind());
101   }
102 
103   /// \brief Return true if this is any of tok::annot_* kind tokens.
isAnnotation()104   bool isAnnotation() const {
105     return tok::isAnnotation(getKind());
106   }
107 
108   /// \brief Return a source location identifier for the specified
109   /// offset in the current file.
getLocation()110   SourceLocation getLocation() const { return Loc; }
getLength()111   unsigned getLength() const {
112     assert(!isAnnotation() && "Annotation tokens have no length field");
113     return UintData;
114   }
115 
setLocation(SourceLocation L)116   void setLocation(SourceLocation L) { Loc = L; }
setLength(unsigned Len)117   void setLength(unsigned Len) {
118     assert(!isAnnotation() && "Annotation tokens have no length field");
119     UintData = Len;
120   }
121 
getAnnotationEndLoc()122   SourceLocation getAnnotationEndLoc() const {
123     assert(isAnnotation() && "Used AnnotEndLocID on non-annotation token");
124     return SourceLocation::getFromRawEncoding(UintData);
125   }
setAnnotationEndLoc(SourceLocation L)126   void setAnnotationEndLoc(SourceLocation L) {
127     assert(isAnnotation() && "Used AnnotEndLocID on non-annotation token");
128     UintData = L.getRawEncoding();
129   }
130 
getLastLoc()131   SourceLocation getLastLoc() const {
132     return isAnnotation() ? getAnnotationEndLoc() : getLocation();
133   }
134 
135   /// \brief SourceRange of the group of tokens that this annotation token
136   /// represents.
getAnnotationRange()137   SourceRange getAnnotationRange() const {
138     return SourceRange(getLocation(), getAnnotationEndLoc());
139   }
setAnnotationRange(SourceRange R)140   void setAnnotationRange(SourceRange R) {
141     setLocation(R.getBegin());
142     setAnnotationEndLoc(R.getEnd());
143   }
144 
getName()145   const char *getName() const {
146     return tok::getTokenName( (tok::TokenKind) Kind);
147   }
148 
149   /// \brief Reset all flags to cleared.
startToken()150   void startToken() {
151     Kind = tok::unknown;
152     Flags = 0;
153     PtrData = 0;
154     UintData = 0;
155     Loc = SourceLocation();
156   }
157 
getIdentifierInfo()158   IdentifierInfo *getIdentifierInfo() const {
159     assert(isNot(tok::raw_identifier) &&
160            "getIdentifierInfo() on a tok::raw_identifier token!");
161     assert(!isAnnotation() &&
162            "getIdentifierInfo() on an annotation token!");
163     if (isLiteral()) return 0;
164     return (IdentifierInfo*) PtrData;
165   }
setIdentifierInfo(IdentifierInfo * II)166   void setIdentifierInfo(IdentifierInfo *II) {
167     PtrData = (void*) II;
168   }
169 
170   /// getRawIdentifierData - For a raw identifier token (i.e., an identifier
171   /// lexed in raw mode), returns a pointer to the start of it in the text
172   /// buffer if known, null otherwise.
getRawIdentifierData()173   const char *getRawIdentifierData() const {
174     assert(is(tok::raw_identifier));
175     return reinterpret_cast<const char*>(PtrData);
176   }
setRawIdentifierData(const char * Ptr)177   void setRawIdentifierData(const char *Ptr) {
178     assert(is(tok::raw_identifier));
179     PtrData = const_cast<char*>(Ptr);
180   }
181 
182   /// getLiteralData - For a literal token (numeric constant, string, etc), this
183   /// returns a pointer to the start of it in the text buffer if known, null
184   /// otherwise.
getLiteralData()185   const char *getLiteralData() const {
186     assert(isLiteral() && "Cannot get literal data of non-literal");
187     return reinterpret_cast<const char*>(PtrData);
188   }
setLiteralData(const char * Ptr)189   void setLiteralData(const char *Ptr) {
190     assert(isLiteral() && "Cannot set literal data of non-literal");
191     PtrData = const_cast<char*>(Ptr);
192   }
193 
getAnnotationValue()194   void *getAnnotationValue() const {
195     assert(isAnnotation() && "Used AnnotVal on non-annotation token");
196     return PtrData;
197   }
setAnnotationValue(void * val)198   void setAnnotationValue(void *val) {
199     assert(isAnnotation() && "Used AnnotVal on non-annotation token");
200     PtrData = val;
201   }
202 
203   /// \brief Set the specified flag.
setFlag(TokenFlags Flag)204   void setFlag(TokenFlags Flag) {
205     Flags |= Flag;
206   }
207 
208   /// \brief Unset the specified flag.
clearFlag(TokenFlags Flag)209   void clearFlag(TokenFlags Flag) {
210     Flags &= ~Flag;
211   }
212 
213   /// \brief Return the internal represtation of the flags.
214   ///
215   /// This is only intended for low-level operations such as writing tokens to
216   /// disk.
getFlags()217   unsigned getFlags() const {
218     return Flags;
219   }
220 
221   /// \brief Set a flag to either true or false.
setFlagValue(TokenFlags Flag,bool Val)222   void setFlagValue(TokenFlags Flag, bool Val) {
223     if (Val)
224       setFlag(Flag);
225     else
226       clearFlag(Flag);
227   }
228 
229   /// isAtStartOfLine - Return true if this token is at the start of a line.
230   ///
isAtStartOfLine()231   bool isAtStartOfLine() const { return (Flags & StartOfLine) ? true : false; }
232 
233   /// \brief Return true if this token has whitespace before it.
234   ///
hasLeadingSpace()235   bool hasLeadingSpace() const { return (Flags & LeadingSpace) ? true : false; }
236 
237   /// \brief Return true if this identifier token should never
238   /// be expanded in the future, due to C99 6.10.3.4p2.
isExpandDisabled()239   bool isExpandDisabled() const {
240     return (Flags & DisableExpand) ? true : false;
241   }
242 
243   /// \brief Return true if we have an ObjC keyword identifier.
244   bool isObjCAtKeyword(tok::ObjCKeywordKind objcKey) const;
245 
246   /// \brief Return the ObjC keyword kind.
247   tok::ObjCKeywordKind getObjCKeywordID() const;
248 
249   /// \brief Return true if this token has trigraphs or escaped newlines in it.
needsCleaning()250   bool needsCleaning() const { return (Flags & NeedsCleaning) ? true : false; }
251 
252   /// \brief Return true if this token has an empty macro before it.
253   ///
hasLeadingEmptyMacro()254   bool hasLeadingEmptyMacro() const {
255     return (Flags & LeadingEmptyMacro) ? true : false;
256   }
257 
258   /// \brief Return true if this token is a string or character literal which
259   /// has a ud-suffix.
hasUDSuffix()260   bool hasUDSuffix() const { return (Flags & HasUDSuffix) ? true : false; }
261 
262   /// Returns true if this token contains a universal character name.
hasUCN()263   bool hasUCN() const { return (Flags & HasUCN) ? true : false; }
264 };
265 
266 /// \brief Information about the conditional stack (\#if directives)
267 /// currently active.
268 struct PPConditionalInfo {
269   /// \brief Location where the conditional started.
270   SourceLocation IfLoc;
271 
272   /// \brief True if this was contained in a skipping directive, e.g.,
273   /// in a "\#if 0" block.
274   bool WasSkipping;
275 
276   /// \brief 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   /// \brief 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