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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/SourceLocation.h"
18 #include "clang/Basic/TokenKinds.h"
19 #include "llvm/ADT/StringRef.h"
20 #include <cassert>
21 
22 namespace clang {
23 
24 class IdentifierInfo;
25 
26 /// Token - This structure provides full information about a lexed token.
27 /// It is not intended to be space efficient, it is intended to return as much
28 /// information as possible about each returned token.  This is expected to be
29 /// compressed into a smaller form if memory footprint is important.
30 ///
31 /// The parser can create a special "annotation token" representing a stream of
32 /// tokens that were parsed and semantically resolved, e.g.: "foo::MyClass<int>"
33 /// can be represented by a single typename annotation token that carries
34 /// information about the SourceRange of the tokens and the type object.
35 class Token {
36   /// The location of the token. This is actually a SourceLocation.
37   unsigned Loc;
38 
39   // Conceptually these next two fields could be in a union.  However, this
40   // causes gcc 4.2 to pessimize LexTokenInternal, a very performance critical
41   // routine. Keeping as separate members with casts until a more beautiful fix
42   // presents itself.
43 
44   /// UintData - This holds either the length of the token text, when
45   /// a normal token, or the end of the SourceRange when an annotation
46   /// token.
47   unsigned UintData;
48 
49   /// PtrData - This is a union of four different pointer types, which depends
50   /// on what type of token this is:
51   ///  Identifiers, keywords, etc:
52   ///    This is an IdentifierInfo*, which contains the uniqued identifier
53   ///    spelling.
54   ///  Literals:  isLiteral() returns true.
55   ///    This is a pointer to the start of the token in a text buffer, which
56   ///    may be dirty (have trigraphs / escaped newlines).
57   ///  Annotations (resolved type names, C++ scopes, etc): isAnnotation().
58   ///    This is a pointer to sema-specific data for the annotation token.
59   ///  Eof:
60   //     This is a pointer to a Decl.
61   ///  Other:
62   ///    This is null.
63   void *PtrData;
64 
65   /// Kind - The actual flavor of token this is.
66   tok::TokenKind Kind;
67 
68   /// Flags - Bits we track about this token, members of the TokenFlags enum.
69   unsigned short Flags;
70 
71 public:
72   // Various flags set per token:
73   enum TokenFlags {
74     StartOfLine   = 0x01,  // At start of line or only after whitespace
75                            // (considering the line after macro expansion).
76     LeadingSpace  = 0x02,  // Whitespace exists before this token (considering
77                            // whitespace after macro expansion).
78     DisableExpand = 0x04,  // This identifier may never be macro expanded.
79     NeedsCleaning = 0x08,  // Contained an escaped newline or trigraph.
80     LeadingEmptyMacro = 0x10, // Empty macro exists before this token.
81     HasUDSuffix = 0x20,    // This string or character literal has a ud-suffix.
82     HasUCN = 0x40,         // This identifier contains a UCN.
83     IgnoredComma = 0x80,   // This comma is not a macro argument separator (MS).
84     StringifiedInMacro = 0x100, // This string or character literal is formed by
85                                 // macro stringizing or charizing operator.
86     CommaAfterElided = 0x200, // The comma following this token was elided (MS).
87   };
88 
getKind()89   tok::TokenKind getKind() const { return Kind; }
setKind(tok::TokenKind K)90   void setKind(tok::TokenKind K) { Kind = K; }
91 
92   /// is/isNot - Predicates to check if this token is a specific kind, as in
93   /// "if (Tok.is(tok::l_brace)) {...}".
is(tok::TokenKind K)94   bool is(tok::TokenKind K) const { return Kind == K; }
isNot(tok::TokenKind K)95   bool isNot(tok::TokenKind K) const { return Kind != K; }
isOneOf(tok::TokenKind K1,tok::TokenKind K2)96   bool isOneOf(tok::TokenKind K1, tok::TokenKind K2) const {
97     return is(K1) || is(K2);
98   }
99   template <typename... Ts>
isOneOf(tok::TokenKind K1,tok::TokenKind K2,Ts...Ks)100   bool isOneOf(tok::TokenKind K1, tok::TokenKind K2, Ts... Ks) const {
101     return is(K1) || isOneOf(K2, Ks...);
102   }
103 
104   /// \brief Return true if this is a raw identifier (when lexing
105   /// in raw mode) or a non-keyword identifier (when lexing in non-raw mode).
isAnyIdentifier()106   bool isAnyIdentifier() const {
107     return tok::isAnyIdentifier(getKind());
108   }
109 
110   /// \brief Return true if this is a "literal", like a numeric
111   /// constant, string, etc.
isLiteral()112   bool isLiteral() const {
113     return tok::isLiteral(getKind());
114   }
115 
116   /// \brief Return true if this is any of tok::annot_* kind tokens.
isAnnotation()117   bool isAnnotation() const {
118     return tok::isAnnotation(getKind());
119   }
120 
121   /// \brief Return a source location identifier for the specified
122   /// offset in the current file.
getLocation()123   SourceLocation getLocation() const {
124     return SourceLocation::getFromRawEncoding(Loc);
125   }
getLength()126   unsigned getLength() const {
127     assert(!isAnnotation() && "Annotation tokens have no length field");
128     return UintData;
129   }
130 
setLocation(SourceLocation L)131   void setLocation(SourceLocation L) { Loc = L.getRawEncoding(); }
setLength(unsigned Len)132   void setLength(unsigned Len) {
133     assert(!isAnnotation() && "Annotation tokens have no length field");
134     UintData = Len;
135   }
136 
getAnnotationEndLoc()137   SourceLocation getAnnotationEndLoc() const {
138     assert(isAnnotation() && "Used AnnotEndLocID on non-annotation token");
139     return SourceLocation::getFromRawEncoding(UintData ? UintData : Loc);
140   }
setAnnotationEndLoc(SourceLocation L)141   void setAnnotationEndLoc(SourceLocation L) {
142     assert(isAnnotation() && "Used AnnotEndLocID on non-annotation token");
143     UintData = L.getRawEncoding();
144   }
145 
getLastLoc()146   SourceLocation getLastLoc() const {
147     return isAnnotation() ? getAnnotationEndLoc() : getLocation();
148   }
149 
getEndLoc()150   SourceLocation getEndLoc() const {
151     return isAnnotation() ? getAnnotationEndLoc()
152                           : getLocation().getLocWithOffset(getLength());
153   }
154 
155   /// \brief SourceRange of the group of tokens that this annotation token
156   /// represents.
getAnnotationRange()157   SourceRange getAnnotationRange() const {
158     return SourceRange(getLocation(), getAnnotationEndLoc());
159   }
setAnnotationRange(SourceRange R)160   void setAnnotationRange(SourceRange R) {
161     setLocation(R.getBegin());
162     setAnnotationEndLoc(R.getEnd());
163   }
164 
getName()165   const char *getName() const { return tok::getTokenName(Kind); }
166 
167   /// \brief Reset all flags to cleared.
startToken()168   void startToken() {
169     Kind = tok::unknown;
170     Flags = 0;
171     PtrData = nullptr;
172     UintData = 0;
173     Loc = SourceLocation().getRawEncoding();
174   }
175 
getIdentifierInfo()176   IdentifierInfo *getIdentifierInfo() const {
177     assert(isNot(tok::raw_identifier) &&
178            "getIdentifierInfo() on a tok::raw_identifier token!");
179     assert(!isAnnotation() &&
180            "getIdentifierInfo() on an annotation token!");
181     if (isLiteral()) return nullptr;
182     if (is(tok::eof)) return nullptr;
183     return (IdentifierInfo*) PtrData;
184   }
setIdentifierInfo(IdentifierInfo * II)185   void setIdentifierInfo(IdentifierInfo *II) {
186     PtrData = (void*) II;
187   }
188 
getEofData()189   const void *getEofData() const {
190     assert(is(tok::eof));
191     return reinterpret_cast<const void *>(PtrData);
192   }
setEofData(const void * D)193   void setEofData(const void *D) {
194     assert(is(tok::eof));
195     assert(!PtrData);
196     PtrData = const_cast<void *>(D);
197   }
198 
199   /// getRawIdentifier - For a raw identifier token (i.e., an identifier
200   /// lexed in raw mode), returns a reference to the text substring in the
201   /// buffer if known.
getRawIdentifier()202   StringRef getRawIdentifier() const {
203     assert(is(tok::raw_identifier));
204     return StringRef(reinterpret_cast<const char *>(PtrData), getLength());
205   }
setRawIdentifierData(const char * Ptr)206   void setRawIdentifierData(const char *Ptr) {
207     assert(is(tok::raw_identifier));
208     PtrData = const_cast<char*>(Ptr);
209   }
210 
211   /// getLiteralData - For a literal token (numeric constant, string, etc), this
212   /// returns a pointer to the start of it in the text buffer if known, null
213   /// otherwise.
getLiteralData()214   const char *getLiteralData() const {
215     assert(isLiteral() && "Cannot get literal data of non-literal");
216     return reinterpret_cast<const char*>(PtrData);
217   }
setLiteralData(const char * Ptr)218   void setLiteralData(const char *Ptr) {
219     assert(isLiteral() && "Cannot set literal data of non-literal");
220     PtrData = const_cast<char*>(Ptr);
221   }
222 
getAnnotationValue()223   void *getAnnotationValue() const {
224     assert(isAnnotation() && "Used AnnotVal on non-annotation token");
225     return PtrData;
226   }
setAnnotationValue(void * val)227   void setAnnotationValue(void *val) {
228     assert(isAnnotation() && "Used AnnotVal on non-annotation token");
229     PtrData = val;
230   }
231 
232   /// \brief Set the specified flag.
setFlag(TokenFlags Flag)233   void setFlag(TokenFlags Flag) {
234     Flags |= Flag;
235   }
236 
237   /// \brief Get the specified flag.
getFlag(TokenFlags Flag)238   bool getFlag(TokenFlags Flag) const {
239     return (Flags & Flag) != 0;
240   }
241 
242   /// \brief Unset the specified flag.
clearFlag(TokenFlags Flag)243   void clearFlag(TokenFlags Flag) {
244     Flags &= ~Flag;
245   }
246 
247   /// \brief Return the internal represtation of the flags.
248   ///
249   /// This is only intended for low-level operations such as writing tokens to
250   /// disk.
getFlags()251   unsigned getFlags() const {
252     return Flags;
253   }
254 
255   /// \brief Set a flag to either true or false.
setFlagValue(TokenFlags Flag,bool Val)256   void setFlagValue(TokenFlags Flag, bool Val) {
257     if (Val)
258       setFlag(Flag);
259     else
260       clearFlag(Flag);
261   }
262 
263   /// isAtStartOfLine - Return true if this token is at the start of a line.
264   ///
isAtStartOfLine()265   bool isAtStartOfLine() const { return getFlag(StartOfLine); }
266 
267   /// \brief Return true if this token has whitespace before it.
268   ///
hasLeadingSpace()269   bool hasLeadingSpace() const { return getFlag(LeadingSpace); }
270 
271   /// \brief Return true if this identifier token should never
272   /// be expanded in the future, due to C99 6.10.3.4p2.
isExpandDisabled()273   bool isExpandDisabled() const { return getFlag(DisableExpand); }
274 
275   /// \brief Return true if we have an ObjC keyword identifier.
276   bool isObjCAtKeyword(tok::ObjCKeywordKind objcKey) const;
277 
278   /// \brief Return the ObjC keyword kind.
279   tok::ObjCKeywordKind getObjCKeywordID() const;
280 
281   /// \brief Return true if this token has trigraphs or escaped newlines in it.
needsCleaning()282   bool needsCleaning() const { return getFlag(NeedsCleaning); }
283 
284   /// \brief Return true if this token has an empty macro before it.
285   ///
hasLeadingEmptyMacro()286   bool hasLeadingEmptyMacro() const { return getFlag(LeadingEmptyMacro); }
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 getFlag(HasUDSuffix); }
291 
292   /// Returns true if this token contains a universal character name.
hasUCN()293   bool hasUCN() const { return getFlag(HasUCN); }
294 
295   /// Returns true if this token is formed by macro by stringizing or charizing
296   /// operator.
stringifiedInMacro()297   bool stringifiedInMacro() const { return getFlag(StringifiedInMacro); }
298 
299   /// Returns true if the comma after this token was elided.
commaAfterElided()300   bool commaAfterElided() const { return getFlag(CommaAfterElided); }
301 };
302 
303 /// \brief Information about the conditional stack (\#if directives)
304 /// currently active.
305 struct PPConditionalInfo {
306   /// \brief Location where the conditional started.
307   SourceLocation IfLoc;
308 
309   /// \brief True if this was contained in a skipping directive, e.g.,
310   /// in a "\#if 0" block.
311   bool WasSkipping;
312 
313   /// \brief True if we have emitted tokens already, and now we're in
314   /// an \#else block or something.  Only useful in Skipping blocks.
315   bool FoundNonSkip;
316 
317   /// \brief True if we've seen a \#else in this block.  If so,
318   /// \#elif/\#else directives are not allowed.
319   bool FoundElse;
320 };
321 
322 } // end namespace clang
323 
324 namespace llvm {
325   template <>
326   struct isPodLike<clang::Token> { static const bool value = true; };
327 } // end namespace llvm
328 
329 #endif // LLVM_CLANG_LEX_TOKEN_H
330