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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 
     81   tok::TokenKind getKind() const { return (tok::TokenKind)Kind; }
     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)) {...}".
     86   bool is(tok::TokenKind K) const { return Kind == (unsigned) 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).
     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.
     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 
    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.
    113   SourceLocation getLocation() const { return Loc; }
    114   unsigned getLength() const {
    115     assert(!isAnnotation() && "Annotation tokens have no length field");
    116     return UintData;
    117   }
    118 
    119   void setLocation(SourceLocation L) { Loc = L; }
    120   void setLength(unsigned Len) {
    121     assert(!isAnnotation() && "Annotation tokens have no length field");
    122     UintData = Len;
    123   }
    124 
    125   SourceLocation getAnnotationEndLoc() const {
    126     assert(isAnnotation() && "Used AnnotEndLocID on non-annotation token");
    127     return SourceLocation::getFromRawEncoding(UintData);
    128   }
    129   void setAnnotationEndLoc(SourceLocation L) {
    130     assert(isAnnotation() && "Used AnnotEndLocID on non-annotation token");
    131     UintData = L.getRawEncoding();
    132   }
    133 
    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.
    140   SourceRange getAnnotationRange() const {
    141     return SourceRange(getLocation(), getAnnotationEndLoc());
    142   }
    143   void setAnnotationRange(SourceRange R) {
    144     setLocation(R.getBegin());
    145     setAnnotationEndLoc(R.getEnd());
    146   }
    147 
    148   const char *getName() const {
    149     return tok::getTokenName( (tok::TokenKind) Kind);
    150   }
    151 
    152   /// startToken - Reset all flags to cleared.
    153   ///
    154   void startToken() {
    155     Kind = tok::unknown;
    156     Flags = 0;
    157     PtrData = 0;
    158     UintData = 0;
    159     Loc = SourceLocation();
    160   }
    161 
    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   }
    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.
    177   const char *getRawIdentifierData() const {
    178     assert(is(tok::raw_identifier));
    179     return reinterpret_cast<const char*>(PtrData);
    180   }
    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.
    189   const char *getLiteralData() const {
    190     assert(isLiteral() && "Cannot get literal data of non-literal");
    191     return reinterpret_cast<const char*>(PtrData);
    192   }
    193   void setLiteralData(const char *Ptr) {
    194     assert(isLiteral() && "Cannot set literal data of non-literal");
    195     PtrData = const_cast<char*>(Ptr);
    196   }
    197 
    198   void *getAnnotationValue() const {
    199     assert(isAnnotation() && "Used AnnotVal on non-annotation token");
    200     return PtrData;
    201   }
    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.
    208   void setFlag(TokenFlags Flag) {
    209     Flags |= Flag;
    210   }
    211 
    212   /// clearFlag - Unset the specified 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.
    220   unsigned getFlags() const {
    221     return Flags;
    222   }
    223 
    224   /// setFlagValue - Set a flag to either true or false.
    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   ///
    234   bool isAtStartOfLine() const { return (Flags & StartOfLine) ? true : false; }
    235 
    236   /// hasLeadingSpace - Return true if this token has whitespace before it.
    237   ///
    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.
    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   ///
    255   bool needsCleaning() const { return (Flags & NeedsCleaning) ? true : false; }
    256 
    257   /// \brief Return true if this token has an empty macro before it.
    258   ///
    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