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      1 //===--- SourceLocation.h - Compact identifier for Source Files -*- 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 SourceLocation class.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #ifndef LLVM_CLANG_SOURCELOCATION_H
     15 #define LLVM_CLANG_SOURCELOCATION_H
     16 
     17 #include "llvm/Support/PointerLikeTypeTraits.h"
     18 #include <utility>
     19 #include <functional>
     20 #include <cassert>
     21 
     22 namespace llvm {
     23   class MemoryBuffer;
     24   class raw_ostream;
     25   class StringRef;
     26   template <typename T> struct DenseMapInfo;
     27   template <typename T> struct isPodLike;
     28 }
     29 
     30 namespace clang {
     31 
     32 class SourceManager;
     33 
     34 /// FileID - This is an opaque identifier used by SourceManager which refers to
     35 /// a source file (MemoryBuffer) along with its #include path and #line data.
     36 ///
     37 class FileID {
     38   /// ID - Opaque identifier, 0 is "invalid". >0 is this module, <-1 is
     39   /// something loaded from another module.
     40   int ID;
     41 public:
     42   FileID() : ID(0) {}
     43 
     44   bool isInvalid() const { return ID == 0; }
     45 
     46   bool operator==(const FileID &RHS) const { return ID == RHS.ID; }
     47   bool operator<(const FileID &RHS) const { return ID < RHS.ID; }
     48   bool operator<=(const FileID &RHS) const { return ID <= RHS.ID; }
     49   bool operator!=(const FileID &RHS) const { return !(*this == RHS); }
     50   bool operator>(const FileID &RHS) const { return RHS < *this; }
     51   bool operator>=(const FileID &RHS) const { return RHS <= *this; }
     52 
     53   static FileID getSentinel() { return get(-1); }
     54   unsigned getHashValue() const { return static_cast<unsigned>(ID); }
     55 
     56 private:
     57   friend class SourceManager;
     58   friend class ASTWriter;
     59   friend class ASTReader;
     60 
     61   static FileID get(int V) {
     62     FileID F;
     63     F.ID = V;
     64     return F;
     65   }
     66   int getOpaqueValue() const { return ID; }
     67 };
     68 
     69 
     70 /// \brief Encodes a location in the source. The SourceManager can decode this
     71 /// to get at the full include stack, line and column information.
     72 ///
     73 /// Technically, a source location is simply an offset into the manager's view
     74 /// of the input source, which is all input buffers (including macro
     75 /// instantiations) concatenated in an effectively arbitrary order. The manager
     76 /// actually maintains two blocks of input buffers. One, starting at offset 0
     77 /// and growing upwards, contains all buffers from this module. The other,
     78 /// starting at the highest possible offset and growing downwards, contains
     79 /// buffers of loaded modules.
     80 ///
     81 /// In addition, one bit of SourceLocation is used for quick access to the
     82 /// information whether the location is in a file or a macro instantiation.
     83 ///
     84 /// It is important that this type remains small. It is currently 32 bits wide.
     85 class SourceLocation {
     86   unsigned ID;
     87   friend class SourceManager;
     88   enum {
     89     MacroIDBit = 1U << 31
     90   };
     91 public:
     92 
     93   SourceLocation() : ID(0) {}
     94 
     95   bool isFileID() const  { return (ID & MacroIDBit) == 0; }
     96   bool isMacroID() const { return (ID & MacroIDBit) != 0; }
     97 
     98   /// \brief Return true if this is a valid SourceLocation object.
     99   ///
    100   /// Invalid SourceLocations are often used when events have no corresponding
    101   /// location in the source (e.g. a diagnostic is required for a command line
    102   /// option).
    103   bool isValid() const { return ID != 0; }
    104   bool isInvalid() const { return ID == 0; }
    105 
    106 private:
    107   /// \brief Return the offset into the manager's global input view.
    108   unsigned getOffset() const {
    109     return ID & ~MacroIDBit;
    110   }
    111 
    112   static SourceLocation getFileLoc(unsigned ID) {
    113     assert((ID & MacroIDBit) == 0 && "Ran out of source locations!");
    114     SourceLocation L;
    115     L.ID = ID;
    116     return L;
    117   }
    118 
    119   static SourceLocation getMacroLoc(unsigned ID) {
    120     assert((ID & MacroIDBit) == 0 && "Ran out of source locations!");
    121     SourceLocation L;
    122     L.ID = MacroIDBit | ID;
    123     return L;
    124   }
    125 public:
    126 
    127   /// getFileLocWithOffset - Return a source location with the specified offset
    128   /// from this file SourceLocation.
    129   SourceLocation getFileLocWithOffset(int Offset) const {
    130     assert(((getOffset()+Offset) & MacroIDBit) == 0 &&
    131            "offset overflow or macro loc");
    132     SourceLocation L;
    133     L.ID = ID+Offset;
    134     return L;
    135   }
    136 
    137   /// getRawEncoding - When a SourceLocation itself cannot be used, this returns
    138   /// an (opaque) 32-bit integer encoding for it.  This should only be passed
    139   /// to SourceLocation::getFromRawEncoding, it should not be inspected
    140   /// directly.
    141   unsigned getRawEncoding() const { return ID; }
    142 
    143   /// getFromRawEncoding - Turn a raw encoding of a SourceLocation object into
    144   /// a real SourceLocation.
    145   static SourceLocation getFromRawEncoding(unsigned Encoding) {
    146     SourceLocation X;
    147     X.ID = Encoding;
    148     return X;
    149   }
    150 
    151   /// getPtrEncoding - When a SourceLocation itself cannot be used, this returns
    152   /// an (opaque) pointer encoding for it.  This should only be passed
    153   /// to SourceLocation::getFromPtrEncoding, it should not be inspected
    154   /// directly.
    155   void* getPtrEncoding() const {
    156     // Double cast to avoid a warning "cast to pointer from integer of different
    157     // size".
    158     return (void*)(uintptr_t)getRawEncoding();
    159   }
    160 
    161   /// getFromPtrEncoding - Turn a pointer encoding of a SourceLocation object
    162   /// into a real SourceLocation.
    163   static SourceLocation getFromPtrEncoding(void *Encoding) {
    164     return getFromRawEncoding((unsigned)(uintptr_t)Encoding);
    165   }
    166 
    167   void print(llvm::raw_ostream &OS, const SourceManager &SM) const;
    168   void dump(const SourceManager &SM) const;
    169 };
    170 
    171 inline bool operator==(const SourceLocation &LHS, const SourceLocation &RHS) {
    172   return LHS.getRawEncoding() == RHS.getRawEncoding();
    173 }
    174 
    175 inline bool operator!=(const SourceLocation &LHS, const SourceLocation &RHS) {
    176   return !(LHS == RHS);
    177 }
    178 
    179 inline bool operator<(const SourceLocation &LHS, const SourceLocation &RHS) {
    180   return LHS.getRawEncoding() < RHS.getRawEncoding();
    181 }
    182 
    183 /// SourceRange - a trival tuple used to represent a source range.
    184 class SourceRange {
    185   SourceLocation B;
    186   SourceLocation E;
    187 public:
    188   SourceRange(): B(SourceLocation()), E(SourceLocation()) {}
    189   SourceRange(SourceLocation loc) : B(loc), E(loc) {}
    190   SourceRange(SourceLocation begin, SourceLocation end) : B(begin), E(end) {}
    191 
    192   SourceLocation getBegin() const { return B; }
    193   SourceLocation getEnd() const { return E; }
    194 
    195   void setBegin(SourceLocation b) { B = b; }
    196   void setEnd(SourceLocation e) { E = e; }
    197 
    198   bool isValid() const { return B.isValid() && E.isValid(); }
    199   bool isInvalid() const { return !isValid(); }
    200 
    201   bool operator==(const SourceRange &X) const {
    202     return B == X.B && E == X.E;
    203   }
    204 
    205   bool operator!=(const SourceRange &X) const {
    206     return B != X.B || E != X.E;
    207   }
    208 };
    209 
    210 /// CharSourceRange - This class represents a character granular source range.
    211 /// The underlying SourceRange can either specify the starting/ending character
    212 /// of the range, or it can specify the start or the range and the start of the
    213 /// last token of the range (a "token range").  In the token range case, the
    214 /// size of the last token must be measured to determine the actual end of the
    215 /// range.
    216 class CharSourceRange {
    217   SourceRange Range;
    218   bool IsTokenRange;
    219 public:
    220   CharSourceRange() : IsTokenRange(false) {}
    221   CharSourceRange(SourceRange R, bool ITR) : Range(R),IsTokenRange(ITR){}
    222 
    223   static CharSourceRange getTokenRange(SourceRange R) {
    224     CharSourceRange Result;
    225     Result.Range = R;
    226     Result.IsTokenRange = true;
    227     return Result;
    228   }
    229 
    230   static CharSourceRange getCharRange(SourceRange R) {
    231     CharSourceRange Result;
    232     Result.Range = R;
    233     Result.IsTokenRange = false;
    234     return Result;
    235   }
    236 
    237   static CharSourceRange getTokenRange(SourceLocation B, SourceLocation E) {
    238     return getTokenRange(SourceRange(B, E));
    239   }
    240   static CharSourceRange getCharRange(SourceLocation B, SourceLocation E) {
    241     return getCharRange(SourceRange(B, E));
    242   }
    243 
    244   /// isTokenRange - Return true if the end of this range specifies the start of
    245   /// the last token.  Return false if the end of this range specifies the last
    246   /// character in the range.
    247   bool isTokenRange() const { return IsTokenRange; }
    248 
    249   SourceLocation getBegin() const { return Range.getBegin(); }
    250   SourceLocation getEnd() const { return Range.getEnd(); }
    251   const SourceRange &getAsRange() const { return Range; }
    252 
    253   void setBegin(SourceLocation b) { Range.setBegin(b); }
    254   void setEnd(SourceLocation e) { Range.setEnd(e); }
    255 
    256   bool isValid() const { return Range.isValid(); }
    257   bool isInvalid() const { return !isValid(); }
    258 };
    259 
    260 /// FullSourceLoc - A SourceLocation and its associated SourceManager.  Useful
    261 /// for argument passing to functions that expect both objects.
    262 class FullSourceLoc : public SourceLocation {
    263   const SourceManager *SrcMgr;
    264 public:
    265   /// Creates a FullSourceLoc where isValid() returns false.
    266   explicit FullSourceLoc() : SrcMgr(0) {}
    267 
    268   explicit FullSourceLoc(SourceLocation Loc, const SourceManager &SM)
    269     : SourceLocation(Loc), SrcMgr(&SM) {}
    270 
    271   const SourceManager &getManager() const {
    272     assert(SrcMgr && "SourceManager is NULL.");
    273     return *SrcMgr;
    274   }
    275 
    276   FileID getFileID() const;
    277 
    278   FullSourceLoc getInstantiationLoc() const;
    279   FullSourceLoc getSpellingLoc() const;
    280 
    281   unsigned getInstantiationLineNumber(bool *Invalid = 0) const;
    282   unsigned getInstantiationColumnNumber(bool *Invalid = 0) const;
    283 
    284   unsigned getSpellingLineNumber(bool *Invalid = 0) const;
    285   unsigned getSpellingColumnNumber(bool *Invalid = 0) const;
    286 
    287   const char *getCharacterData(bool *Invalid = 0) const;
    288 
    289   const llvm::MemoryBuffer* getBuffer(bool *Invalid = 0) const;
    290 
    291   /// getBufferData - Return a StringRef to the source buffer data for the
    292   /// specified FileID.
    293   llvm::StringRef getBufferData(bool *Invalid = 0) const;
    294 
    295   /// getDecomposedLoc - Decompose the specified location into a raw FileID +
    296   /// Offset pair.  The first element is the FileID, the second is the
    297   /// offset from the start of the buffer of the location.
    298   std::pair<FileID, unsigned> getDecomposedLoc() const;
    299 
    300   bool isInSystemHeader() const;
    301 
    302   /// \brief Determines the order of 2 source locations in the translation unit.
    303   ///
    304   /// \returns true if this source location comes before 'Loc', false otherwise.
    305   bool isBeforeInTranslationUnitThan(SourceLocation Loc) const;
    306 
    307   /// \brief Determines the order of 2 source locations in the translation unit.
    308   ///
    309   /// \returns true if this source location comes before 'Loc', false otherwise.
    310   bool isBeforeInTranslationUnitThan(FullSourceLoc Loc) const {
    311     assert(Loc.isValid());
    312     assert(SrcMgr == Loc.SrcMgr && "Loc comes from another SourceManager!");
    313     return isBeforeInTranslationUnitThan((SourceLocation)Loc);
    314   }
    315 
    316   /// \brief Comparison function class, useful for sorting FullSourceLocs.
    317   struct BeforeThanCompare : public std::binary_function<FullSourceLoc,
    318                                                          FullSourceLoc, bool> {
    319     bool operator()(const FullSourceLoc& lhs, const FullSourceLoc& rhs) const {
    320       return lhs.isBeforeInTranslationUnitThan(rhs);
    321     }
    322   };
    323 
    324   /// Prints information about this FullSourceLoc to stderr. Useful for
    325   ///  debugging.
    326   void dump() const { SourceLocation::dump(*SrcMgr); }
    327 
    328   friend inline bool
    329   operator==(const FullSourceLoc &LHS, const FullSourceLoc &RHS) {
    330     return LHS.getRawEncoding() == RHS.getRawEncoding() &&
    331           LHS.SrcMgr == RHS.SrcMgr;
    332   }
    333 
    334   friend inline bool
    335   operator!=(const FullSourceLoc &LHS, const FullSourceLoc &RHS) {
    336     return !(LHS == RHS);
    337   }
    338 
    339 };
    340 
    341 /// PresumedLoc - This class represents an unpacked "presumed" location which
    342 /// can be presented to the user.  A 'presumed' location can be modified by
    343 /// #line and GNU line marker directives and is always the instantiation point
    344 /// of a normal location.
    345 ///
    346 /// You can get a PresumedLoc from a SourceLocation with SourceManager.
    347 class PresumedLoc {
    348   const char *Filename;
    349   unsigned Line, Col;
    350   SourceLocation IncludeLoc;
    351 public:
    352   PresumedLoc() : Filename(0) {}
    353   PresumedLoc(const char *FN, unsigned Ln, unsigned Co, SourceLocation IL)
    354     : Filename(FN), Line(Ln), Col(Co), IncludeLoc(IL) {
    355   }
    356 
    357   /// isInvalid - Return true if this object is invalid or uninitialized. This
    358   /// occurs when created with invalid source locations or when walking off
    359   /// the top of a #include stack.
    360   bool isInvalid() const { return Filename == 0; }
    361   bool isValid() const { return Filename != 0; }
    362 
    363   /// getFilename - Return the presumed filename of this location.  This can be
    364   /// affected by #line etc.
    365   const char *getFilename() const { return Filename; }
    366 
    367   /// getLine - Return the presumed line number of this location.  This can be
    368   /// affected by #line etc.
    369   unsigned getLine() const { return Line; }
    370 
    371   /// getColumn - Return the presumed column number of this location.  This can
    372   /// not be affected by #line, but is packaged here for convenience.
    373   unsigned getColumn() const { return Col; }
    374 
    375   /// getIncludeLoc - Return the presumed include location of this location.
    376   /// This can be affected by GNU linemarker directives.
    377   SourceLocation getIncludeLoc() const { return IncludeLoc; }
    378 };
    379 
    380 
    381 }  // end namespace clang
    382 
    383 namespace llvm {
    384   /// Define DenseMapInfo so that FileID's can be used as keys in DenseMap and
    385   /// DenseSets.
    386   template <>
    387   struct DenseMapInfo<clang::FileID> {
    388     static inline clang::FileID getEmptyKey() {
    389       return clang::FileID();
    390     }
    391     static inline clang::FileID getTombstoneKey() {
    392       return clang::FileID::getSentinel();
    393     }
    394 
    395     static unsigned getHashValue(clang::FileID S) {
    396       return S.getHashValue();
    397     }
    398 
    399     static bool isEqual(clang::FileID LHS, clang::FileID RHS) {
    400       return LHS == RHS;
    401     }
    402   };
    403 
    404   template <>
    405   struct isPodLike<clang::SourceLocation> { static const bool value = true; };
    406   template <>
    407   struct isPodLike<clang::FileID> { static const bool value = true; };
    408 
    409   // Teach SmallPtrSet how to handle SourceLocation.
    410   template<>
    411   class PointerLikeTypeTraits<clang::SourceLocation> {
    412   public:
    413     static inline void *getAsVoidPointer(clang::SourceLocation L) {
    414       return L.getPtrEncoding();
    415     }
    416     static inline clang::SourceLocation getFromVoidPointer(void *P) {
    417       return clang::SourceLocation::getFromRawEncoding((unsigned)(uintptr_t)P);
    418     }
    419     enum { NumLowBitsAvailable = 0 };
    420   };
    421 
    422 }  // end namespace llvm
    423 
    424 #endif
    425