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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 "clang/Basic/LLVM.h"
     18 #include "llvm/Support/PointerLikeTypeTraits.h"
     19 #include "llvm/Support/Compiler.h"
     20 #include <utility>
     21 #include <functional>
     22 #include <cassert>
     23 
     24 namespace llvm {
     25   class MemoryBuffer;
     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 /// expansions) concatenated in an effectively arbitrary order. The manager
     76 /// actually maintains two blocks of input buffers. One, starting at offset
     77 /// 0 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 expansion.
     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   friend class ASTReader;
     89   friend class ASTWriter;
     90   enum {
     91     MacroIDBit = 1U << 31
     92   };
     93 public:
     94 
     95   SourceLocation() : ID(0) {}
     96 
     97   bool isFileID() const  { return (ID & MacroIDBit) == 0; }
     98   bool isMacroID() const { return (ID & MacroIDBit) != 0; }
     99 
    100   /// \brief Return true if this is a valid SourceLocation object.
    101   ///
    102   /// Invalid SourceLocations are often used when events have no corresponding
    103   /// location in the source (e.g. a diagnostic is required for a command line
    104   /// option).
    105   bool isValid() const { return ID != 0; }
    106   bool isInvalid() const { return ID == 0; }
    107 
    108 private:
    109   /// \brief Return the offset into the manager's global input view.
    110   unsigned getOffset() const {
    111     return ID & ~MacroIDBit;
    112   }
    113 
    114   static SourceLocation getFileLoc(unsigned ID) {
    115     assert((ID & MacroIDBit) == 0 && "Ran out of source locations!");
    116     SourceLocation L;
    117     L.ID = ID;
    118     return L;
    119   }
    120 
    121   static SourceLocation getMacroLoc(unsigned ID) {
    122     assert((ID & MacroIDBit) == 0 && "Ran out of source locations!");
    123     SourceLocation L;
    124     L.ID = MacroIDBit | ID;
    125     return L;
    126   }
    127 public:
    128 
    129   /// \brief Return a source location with the specified offset from this
    130   /// SourceLocation.
    131   SourceLocation getLocWithOffset(int Offset) const {
    132     assert(((getOffset()+Offset) & MacroIDBit) == 0 && "offset overflow");
    133     SourceLocation L;
    134     L.ID = ID+Offset;
    135     return L;
    136   }
    137 
    138   /// getRawEncoding - When a SourceLocation itself cannot be used, this returns
    139   /// an (opaque) 32-bit integer encoding for it.  This should only be passed
    140   /// to SourceLocation::getFromRawEncoding, it should not be inspected
    141   /// directly.
    142   unsigned getRawEncoding() const { return ID; }
    143 
    144   /// getFromRawEncoding - Turn a raw encoding of a SourceLocation object into
    145   /// a real SourceLocation.
    146   static SourceLocation getFromRawEncoding(unsigned Encoding) {
    147     SourceLocation X;
    148     X.ID = Encoding;
    149     return X;
    150   }
    151 
    152   /// getPtrEncoding - When a SourceLocation itself cannot be used, this returns
    153   /// an (opaque) pointer encoding for it.  This should only be passed
    154   /// to SourceLocation::getFromPtrEncoding, it should not be inspected
    155   /// directly.
    156   void* getPtrEncoding() const {
    157     // Double cast to avoid a warning "cast to pointer from integer of different
    158     // size".
    159     return (void*)(uintptr_t)getRawEncoding();
    160   }
    161 
    162   /// getFromPtrEncoding - Turn a pointer encoding of a SourceLocation object
    163   /// into a real SourceLocation.
    164   static SourceLocation getFromPtrEncoding(void *Encoding) {
    165     return getFromRawEncoding((unsigned)(uintptr_t)Encoding);
    166   }
    167 
    168   void print(raw_ostream &OS, const SourceManager &SM) const;
    169   void dump(const SourceManager &SM) const;
    170 };
    171 
    172 inline bool operator==(const SourceLocation &LHS, const SourceLocation &RHS) {
    173   return LHS.getRawEncoding() == RHS.getRawEncoding();
    174 }
    175 
    176 inline bool operator!=(const SourceLocation &LHS, const SourceLocation &RHS) {
    177   return !(LHS == RHS);
    178 }
    179 
    180 inline bool operator<(const SourceLocation &LHS, const SourceLocation &RHS) {
    181   return LHS.getRawEncoding() < RHS.getRawEncoding();
    182 }
    183 
    184 /// SourceRange - a trival tuple used to represent a source range.
    185 class SourceRange {
    186   SourceLocation B;
    187   SourceLocation E;
    188 public:
    189   SourceRange(): B(SourceLocation()), E(SourceLocation()) {}
    190   SourceRange(SourceLocation loc) : B(loc), E(loc) {}
    191   SourceRange(SourceLocation begin, SourceLocation end) : B(begin), E(end) {}
    192 
    193   SourceLocation getBegin() const { return B; }
    194   SourceLocation getEnd() const { return E; }
    195 
    196   void setBegin(SourceLocation b) { B = b; }
    197   void setEnd(SourceLocation e) { E = e; }
    198 
    199   bool isValid() const { return B.isValid() && E.isValid(); }
    200   bool isInvalid() const { return !isValid(); }
    201 
    202   bool operator==(const SourceRange &X) const {
    203     return B == X.B && E == X.E;
    204   }
    205 
    206   bool operator!=(const SourceRange &X) const {
    207     return B != X.B || E != X.E;
    208   }
    209 };
    210 
    211 /// CharSourceRange - This class represents a character granular source range.
    212 /// The underlying SourceRange can either specify the starting/ending character
    213 /// of the range, or it can specify the start or the range and the start of the
    214 /// last token of the range (a "token range").  In the token range case, the
    215 /// size of the last token must be measured to determine the actual end of the
    216 /// range.
    217 class CharSourceRange {
    218   SourceRange Range;
    219   bool IsTokenRange;
    220 public:
    221   CharSourceRange() : IsTokenRange(false) {}
    222   CharSourceRange(SourceRange R, bool ITR) : Range(R),IsTokenRange(ITR){}
    223 
    224   static CharSourceRange getTokenRange(SourceRange R) {
    225     CharSourceRange Result;
    226     Result.Range = R;
    227     Result.IsTokenRange = true;
    228     return Result;
    229   }
    230 
    231   static CharSourceRange getCharRange(SourceRange R) {
    232     CharSourceRange Result;
    233     Result.Range = R;
    234     Result.IsTokenRange = false;
    235     return Result;
    236   }
    237 
    238   static CharSourceRange getTokenRange(SourceLocation B, SourceLocation E) {
    239     return getTokenRange(SourceRange(B, E));
    240   }
    241   static CharSourceRange getCharRange(SourceLocation B, SourceLocation E) {
    242     return getCharRange(SourceRange(B, E));
    243   }
    244 
    245   /// isTokenRange - Return true if the end of this range specifies the start of
    246   /// the last token.  Return false if the end of this range specifies the last
    247   /// character in the range.
    248   bool isTokenRange() const { return IsTokenRange; }
    249   bool isCharRange() const { return !IsTokenRange; }
    250 
    251   SourceLocation getBegin() const { return Range.getBegin(); }
    252   SourceLocation getEnd() const { return Range.getEnd(); }
    253   const SourceRange &getAsRange() const { return Range; }
    254 
    255   void setBegin(SourceLocation b) { Range.setBegin(b); }
    256   void setEnd(SourceLocation e) { Range.setEnd(e); }
    257 
    258   bool isValid() const { return Range.isValid(); }
    259   bool isInvalid() const { return !isValid(); }
    260 };
    261 
    262 /// FullSourceLoc - A SourceLocation and its associated SourceManager.  Useful
    263 /// for argument passing to functions that expect both objects.
    264 class FullSourceLoc : public SourceLocation {
    265   const SourceManager *SrcMgr;
    266 public:
    267   /// Creates a FullSourceLoc where isValid() returns false.
    268   explicit FullSourceLoc() : SrcMgr(0) {}
    269 
    270   explicit FullSourceLoc(SourceLocation Loc, const SourceManager &SM)
    271     : SourceLocation(Loc), SrcMgr(&SM) {}
    272 
    273   const SourceManager &getManager() const {
    274     assert(SrcMgr && "SourceManager is NULL.");
    275     return *SrcMgr;
    276   }
    277 
    278   FileID getFileID() const;
    279 
    280   FullSourceLoc getExpansionLoc() const;
    281   FullSourceLoc getSpellingLoc() const;
    282 
    283   unsigned getExpansionLineNumber(bool *Invalid = 0) const;
    284   unsigned getExpansionColumnNumber(bool *Invalid = 0) const;
    285 
    286   unsigned getSpellingLineNumber(bool *Invalid = 0) const;
    287   unsigned getSpellingColumnNumber(bool *Invalid = 0) const;
    288 
    289   const char *getCharacterData(bool *Invalid = 0) const;
    290 
    291   const llvm::MemoryBuffer* getBuffer(bool *Invalid = 0) const;
    292 
    293   /// getBufferData - Return a StringRef to the source buffer data for the
    294   /// specified FileID.
    295   StringRef getBufferData(bool *Invalid = 0) const;
    296 
    297   /// getDecomposedLoc - Decompose the specified location into a raw FileID +
    298   /// Offset pair.  The first element is the FileID, the second is the
    299   /// offset from the start of the buffer of the location.
    300   std::pair<FileID, unsigned> getDecomposedLoc() const;
    301 
    302   bool isInSystemHeader() const;
    303 
    304   /// \brief Determines the order of 2 source locations in the translation unit.
    305   ///
    306   /// \returns true if this source location comes before 'Loc', false otherwise.
    307   bool isBeforeInTranslationUnitThan(SourceLocation Loc) const;
    308 
    309   /// \brief Determines the order of 2 source locations in the translation unit.
    310   ///
    311   /// \returns true if this source location comes before 'Loc', false otherwise.
    312   bool isBeforeInTranslationUnitThan(FullSourceLoc Loc) const {
    313     assert(Loc.isValid());
    314     assert(SrcMgr == Loc.SrcMgr && "Loc comes from another SourceManager!");
    315     return isBeforeInTranslationUnitThan((SourceLocation)Loc);
    316   }
    317 
    318   /// \brief Comparison function class, useful for sorting FullSourceLocs.
    319   struct BeforeThanCompare : public std::binary_function<FullSourceLoc,
    320                                                          FullSourceLoc, bool> {
    321     bool operator()(const FullSourceLoc& lhs, const FullSourceLoc& rhs) const {
    322       return lhs.isBeforeInTranslationUnitThan(rhs);
    323     }
    324   };
    325 
    326   /// Prints information about this FullSourceLoc to stderr. Useful for
    327   ///  debugging.
    328   LLVM_ATTRIBUTE_USED void dump() const;
    329 
    330   friend inline bool
    331   operator==(const FullSourceLoc &LHS, const FullSourceLoc &RHS) {
    332     return LHS.getRawEncoding() == RHS.getRawEncoding() &&
    333           LHS.SrcMgr == RHS.SrcMgr;
    334   }
    335 
    336   friend inline bool
    337   operator!=(const FullSourceLoc &LHS, const FullSourceLoc &RHS) {
    338     return !(LHS == RHS);
    339   }
    340 
    341 };
    342 
    343 /// PresumedLoc - This class represents an unpacked "presumed" location which
    344 /// can be presented to the user.  A 'presumed' location can be modified by
    345 /// #line and GNU line marker directives and is always the expansion point of
    346 /// a normal location.
    347 ///
    348 /// You can get a PresumedLoc from a SourceLocation with SourceManager.
    349 class PresumedLoc {
    350   const char *Filename;
    351   unsigned Line, Col;
    352   SourceLocation IncludeLoc;
    353 public:
    354   PresumedLoc() : Filename(0) {}
    355   PresumedLoc(const char *FN, unsigned Ln, unsigned Co, SourceLocation IL)
    356     : Filename(FN), Line(Ln), Col(Co), IncludeLoc(IL) {
    357   }
    358 
    359   /// isInvalid - Return true if this object is invalid or uninitialized. This
    360   /// occurs when created with invalid source locations or when walking off
    361   /// the top of a #include stack.
    362   bool isInvalid() const { return Filename == 0; }
    363   bool isValid() const { return Filename != 0; }
    364 
    365   /// getFilename - Return the presumed filename of this location.  This can be
    366   /// affected by #line etc.
    367   const char *getFilename() const { return Filename; }
    368 
    369   /// getLine - Return the presumed line number of this location.  This can be
    370   /// affected by #line etc.
    371   unsigned getLine() const { return Line; }
    372 
    373   /// getColumn - Return the presumed column number of this location.  This can
    374   /// not be affected by #line, but is packaged here for convenience.
    375   unsigned getColumn() const { return Col; }
    376 
    377   /// getIncludeLoc - Return the presumed include location of this location.
    378   /// This can be affected by GNU linemarker directives.
    379   SourceLocation getIncludeLoc() const { return IncludeLoc; }
    380 };
    381 
    382 
    383 }  // end namespace clang
    384 
    385 namespace llvm {
    386   /// Define DenseMapInfo so that FileID's can be used as keys in DenseMap and
    387   /// DenseSets.
    388   template <>
    389   struct DenseMapInfo<clang::FileID> {
    390     static inline clang::FileID getEmptyKey() {
    391       return clang::FileID();
    392     }
    393     static inline clang::FileID getTombstoneKey() {
    394       return clang::FileID::getSentinel();
    395     }
    396 
    397     static unsigned getHashValue(clang::FileID S) {
    398       return S.getHashValue();
    399     }
    400 
    401     static bool isEqual(clang::FileID LHS, clang::FileID RHS) {
    402       return LHS == RHS;
    403     }
    404   };
    405 
    406   template <>
    407   struct isPodLike<clang::SourceLocation> { static const bool value = true; };
    408   template <>
    409   struct isPodLike<clang::FileID> { static const bool value = true; };
    410 
    411   // Teach SmallPtrSet how to handle SourceLocation.
    412   template<>
    413   class PointerLikeTypeTraits<clang::SourceLocation> {
    414   public:
    415     static inline void *getAsVoidPointer(clang::SourceLocation L) {
    416       return L.getPtrEncoding();
    417     }
    418     static inline clang::SourceLocation getFromVoidPointer(void *P) {
    419       return clang::SourceLocation::getFromRawEncoding((unsigned)(uintptr_t)P);
    420     }
    421     enum { NumLowBitsAvailable = 0 };
    422   };
    423 
    424 }  // end namespace llvm
    425 
    426 #endif
    427