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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 /// \file
     11 /// \brief Defines the clang::SourceLocation class and associated facilities.
     12 ///
     13 //===----------------------------------------------------------------------===//
     14 
     15 #ifndef LLVM_CLANG_BASIC_SOURCELOCATION_H
     16 #define LLVM_CLANG_BASIC_SOURCELOCATION_H
     17 
     18 #include "clang/Basic/LLVM.h"
     19 #include "llvm/Support/Compiler.h"
     20 #include "llvm/Support/PointerLikeTypeTraits.h"
     21 #include <cassert>
     22 #include <functional>
     23 #include <string>
     24 #include <utility>
     25 
     26 namespace llvm {
     27   class MemoryBuffer;
     28   template <typename T> struct DenseMapInfo;
     29   template <typename T> struct isPodLike;
     30 }
     31 
     32 namespace clang {
     33 
     34 class SourceManager;
     35 
     36 /// \brief An opaque identifier used by SourceManager which refers to a
     37 /// source file (MemoryBuffer) along with its \#include path and \#line data.
     38 ///
     39 class FileID {
     40   /// \brief A mostly-opaque identifier, where 0 is "invalid", >0 is
     41   /// this module, and <-1 is something loaded from another module.
     42   int ID;
     43 public:
     44   FileID() : ID(0) {}
     45 
     46   bool isValid() const { return ID != 0; }
     47   bool isInvalid() const { return ID == 0; }
     48 
     49   bool operator==(const FileID &RHS) const { return ID == RHS.ID; }
     50   bool operator<(const FileID &RHS) const { return ID < RHS.ID; }
     51   bool operator<=(const FileID &RHS) const { return ID <= RHS.ID; }
     52   bool operator!=(const FileID &RHS) const { return !(*this == RHS); }
     53   bool operator>(const FileID &RHS) const { return RHS < *this; }
     54   bool operator>=(const FileID &RHS) const { return RHS <= *this; }
     55 
     56   static FileID getSentinel() { return get(-1); }
     57   unsigned getHashValue() const { return static_cast<unsigned>(ID); }
     58 
     59 private:
     60   friend class SourceManager;
     61   friend class ASTWriter;
     62   friend class ASTReader;
     63 
     64   static FileID get(int V) {
     65     FileID F;
     66     F.ID = V;
     67     return F;
     68   }
     69   int getOpaqueValue() const { return ID; }
     70 };
     71 
     72 
     73 /// \brief Encodes a location in the source. The SourceManager can decode this
     74 /// to get at the full include stack, line and column information.
     75 ///
     76 /// Technically, a source location is simply an offset into the manager's view
     77 /// of the input source, which is all input buffers (including macro
     78 /// expansions) concatenated in an effectively arbitrary order. The manager
     79 /// actually maintains two blocks of input buffers. One, starting at offset
     80 /// 0 and growing upwards, contains all buffers from this module. The other,
     81 /// starting at the highest possible offset and growing downwards, contains
     82 /// buffers of loaded modules.
     83 ///
     84 /// In addition, one bit of SourceLocation is used for quick access to the
     85 /// information whether the location is in a file or a macro expansion.
     86 ///
     87 /// It is important that this type remains small. It is currently 32 bits wide.
     88 class SourceLocation {
     89   unsigned ID;
     90   friend class SourceManager;
     91   friend class ASTReader;
     92   friend class ASTWriter;
     93   enum : unsigned {
     94     MacroIDBit = 1U << 31
     95   };
     96 public:
     97 
     98   SourceLocation() : ID(0) {}
     99 
    100   bool isFileID() const  { return (ID & MacroIDBit) == 0; }
    101   bool isMacroID() const { return (ID & MacroIDBit) != 0; }
    102 
    103   /// \brief Return true if this is a valid SourceLocation object.
    104   ///
    105   /// Invalid SourceLocations are often used when events have no corresponding
    106   /// location in the source (e.g. a diagnostic is required for a command line
    107   /// option).
    108   bool isValid() const { return ID != 0; }
    109   bool isInvalid() const { return ID == 0; }
    110 
    111 private:
    112   /// \brief Return the offset into the manager's global input view.
    113   unsigned getOffset() const {
    114     return ID & ~MacroIDBit;
    115   }
    116 
    117   static SourceLocation getFileLoc(unsigned ID) {
    118     assert((ID & MacroIDBit) == 0 && "Ran out of source locations!");
    119     SourceLocation L;
    120     L.ID = ID;
    121     return L;
    122   }
    123 
    124   static SourceLocation getMacroLoc(unsigned ID) {
    125     assert((ID & MacroIDBit) == 0 && "Ran out of source locations!");
    126     SourceLocation L;
    127     L.ID = MacroIDBit | ID;
    128     return L;
    129   }
    130 public:
    131 
    132   /// \brief Return a source location with the specified offset from this
    133   /// SourceLocation.
    134   SourceLocation getLocWithOffset(int Offset) const {
    135     assert(((getOffset()+Offset) & MacroIDBit) == 0 && "offset overflow");
    136     SourceLocation L;
    137     L.ID = ID+Offset;
    138     return L;
    139   }
    140 
    141   /// \brief When a SourceLocation itself cannot be used, this returns
    142   /// an (opaque) 32-bit integer encoding for it.
    143   ///
    144   /// This should only be passed to SourceLocation::getFromRawEncoding, it
    145   /// should not be inspected directly.
    146   unsigned getRawEncoding() const { return ID; }
    147 
    148   /// \brief Turn a raw encoding of a SourceLocation object into
    149   /// a real SourceLocation.
    150   ///
    151   /// \see getRawEncoding.
    152   static SourceLocation getFromRawEncoding(unsigned Encoding) {
    153     SourceLocation X;
    154     X.ID = Encoding;
    155     return X;
    156   }
    157 
    158   /// \brief When a SourceLocation itself cannot be used, this returns
    159   /// an (opaque) pointer encoding for it.
    160   ///
    161   /// This should only be passed to SourceLocation::getFromPtrEncoding, it
    162   /// should not be inspected directly.
    163   void* getPtrEncoding() const {
    164     // Double cast to avoid a warning "cast to pointer from integer of different
    165     // size".
    166     return (void*)(uintptr_t)getRawEncoding();
    167   }
    168 
    169   /// \brief Turn a pointer encoding of a SourceLocation object back
    170   /// into a real SourceLocation.
    171   static SourceLocation getFromPtrEncoding(const void *Encoding) {
    172     return getFromRawEncoding((unsigned)(uintptr_t)Encoding);
    173   }
    174 
    175   void print(raw_ostream &OS, const SourceManager &SM) const;
    176   std::string printToString(const SourceManager &SM) const;
    177   void dump(const SourceManager &SM) const;
    178 };
    179 
    180 inline bool operator==(const SourceLocation &LHS, const SourceLocation &RHS) {
    181   return LHS.getRawEncoding() == RHS.getRawEncoding();
    182 }
    183 
    184 inline bool operator!=(const SourceLocation &LHS, const SourceLocation &RHS) {
    185   return !(LHS == RHS);
    186 }
    187 
    188 inline bool operator<(const SourceLocation &LHS, const SourceLocation &RHS) {
    189   return LHS.getRawEncoding() < RHS.getRawEncoding();
    190 }
    191 
    192 /// \brief A trivial tuple used to represent a source range.
    193 class SourceRange {
    194   SourceLocation B;
    195   SourceLocation E;
    196 public:
    197   SourceRange(): B(SourceLocation()), E(SourceLocation()) {}
    198   SourceRange(SourceLocation loc) : B(loc), E(loc) {}
    199   SourceRange(SourceLocation begin, SourceLocation end) : B(begin), E(end) {}
    200 
    201   SourceLocation getBegin() const { return B; }
    202   SourceLocation getEnd() const { return E; }
    203 
    204   void setBegin(SourceLocation b) { B = b; }
    205   void setEnd(SourceLocation e) { E = e; }
    206 
    207   bool isValid() const { return B.isValid() && E.isValid(); }
    208   bool isInvalid() const { return !isValid(); }
    209 
    210   bool operator==(const SourceRange &X) const {
    211     return B == X.B && E == X.E;
    212   }
    213 
    214   bool operator!=(const SourceRange &X) const {
    215     return B != X.B || E != X.E;
    216   }
    217 };
    218 
    219 /// \brief Represents a character-granular source range.
    220 ///
    221 /// The underlying SourceRange can either specify the starting/ending character
    222 /// of the range, or it can specify the start of the range and the start of the
    223 /// last token of the range (a "token range").  In the token range case, the
    224 /// size of the last token must be measured to determine the actual end of the
    225 /// range.
    226 class CharSourceRange {
    227   SourceRange Range;
    228   bool IsTokenRange;
    229 public:
    230   CharSourceRange() : IsTokenRange(false) {}
    231   CharSourceRange(SourceRange R, bool ITR) : Range(R), IsTokenRange(ITR) {}
    232 
    233   static CharSourceRange getTokenRange(SourceRange R) {
    234     return CharSourceRange(R, true);
    235   }
    236 
    237   static CharSourceRange getCharRange(SourceRange R) {
    238     return CharSourceRange(R, false);
    239   }
    240 
    241   static CharSourceRange getTokenRange(SourceLocation B, SourceLocation E) {
    242     return getTokenRange(SourceRange(B, E));
    243   }
    244   static CharSourceRange getCharRange(SourceLocation B, SourceLocation E) {
    245     return getCharRange(SourceRange(B, E));
    246   }
    247 
    248   /// \brief Return true if the end of this range specifies the start of
    249   /// the last token.  Return false if the end of this range specifies the last
    250   /// character in the range.
    251   bool isTokenRange() const { return IsTokenRange; }
    252   bool isCharRange() const { return !IsTokenRange; }
    253 
    254   SourceLocation getBegin() const { return Range.getBegin(); }
    255   SourceLocation getEnd() const { return Range.getEnd(); }
    256   SourceRange getAsRange() const { return Range; }
    257 
    258   void setBegin(SourceLocation b) { Range.setBegin(b); }
    259   void setEnd(SourceLocation e) { Range.setEnd(e); }
    260 
    261   bool isValid() const { return Range.isValid(); }
    262   bool isInvalid() const { return !isValid(); }
    263 };
    264 
    265 /// \brief A SourceLocation and its associated SourceManager.
    266 ///
    267 /// This is useful for argument passing to functions that expect both objects.
    268 class FullSourceLoc : public SourceLocation {
    269   const SourceManager *SrcMgr;
    270 public:
    271   /// \brief Creates a FullSourceLoc where isValid() returns \c false.
    272   explicit FullSourceLoc() : SrcMgr(nullptr) {}
    273 
    274   explicit FullSourceLoc(SourceLocation Loc, const SourceManager &SM)
    275     : SourceLocation(Loc), SrcMgr(&SM) {}
    276 
    277   /// \pre This FullSourceLoc has an associated SourceManager.
    278   const SourceManager &getManager() const {
    279     assert(SrcMgr && "SourceManager is NULL.");
    280     return *SrcMgr;
    281   }
    282 
    283   FileID getFileID() const;
    284 
    285   FullSourceLoc getExpansionLoc() const;
    286   FullSourceLoc getSpellingLoc() const;
    287 
    288   unsigned getExpansionLineNumber(bool *Invalid = nullptr) const;
    289   unsigned getExpansionColumnNumber(bool *Invalid = nullptr) const;
    290 
    291   unsigned getSpellingLineNumber(bool *Invalid = nullptr) const;
    292   unsigned getSpellingColumnNumber(bool *Invalid = nullptr) const;
    293 
    294   const char *getCharacterData(bool *Invalid = nullptr) const;
    295 
    296 
    297   /// \brief Return a StringRef to the source buffer data for the
    298   /// specified FileID.
    299   StringRef getBufferData(bool *Invalid = nullptr) const;
    300 
    301   /// \brief Decompose the specified location into a raw FileID + Offset pair.
    302   ///
    303   /// The first element is the FileID, the second is the offset from the
    304   /// start of the buffer of the location.
    305   std::pair<FileID, unsigned> getDecomposedLoc() const;
    306 
    307   bool isInSystemHeader() 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(SourceLocation Loc) const;
    313 
    314   /// \brief Determines the order of 2 source locations in the translation unit.
    315   ///
    316   /// \returns true if this source location comes before 'Loc', false otherwise.
    317   bool isBeforeInTranslationUnitThan(FullSourceLoc Loc) const {
    318     assert(Loc.isValid());
    319     assert(SrcMgr == Loc.SrcMgr && "Loc comes from another SourceManager!");
    320     return isBeforeInTranslationUnitThan((SourceLocation)Loc);
    321   }
    322 
    323   /// \brief Comparison function class, useful for sorting FullSourceLocs.
    324   struct BeforeThanCompare : public std::binary_function<FullSourceLoc,
    325                                                          FullSourceLoc, bool> {
    326     bool operator()(const FullSourceLoc& lhs, const FullSourceLoc& rhs) const {
    327       return lhs.isBeforeInTranslationUnitThan(rhs);
    328     }
    329   };
    330 
    331   /// \brief Prints information about this FullSourceLoc to stderr.
    332   ///
    333   /// This is useful for debugging.
    334   void dump() const;
    335 
    336   friend inline bool
    337   operator==(const FullSourceLoc &LHS, const FullSourceLoc &RHS) {
    338     return LHS.getRawEncoding() == RHS.getRawEncoding() &&
    339           LHS.SrcMgr == RHS.SrcMgr;
    340   }
    341 
    342   friend inline bool
    343   operator!=(const FullSourceLoc &LHS, const FullSourceLoc &RHS) {
    344     return !(LHS == RHS);
    345   }
    346 
    347 };
    348 
    349 /// \brief Represents an unpacked "presumed" location which can be presented
    350 /// to the user.
    351 ///
    352 /// A 'presumed' location can be modified by \#line and GNU line marker
    353 /// directives and is always the expansion point of a normal location.
    354 ///
    355 /// You can get a PresumedLoc from a SourceLocation with SourceManager.
    356 class PresumedLoc {
    357   const char *Filename;
    358   unsigned Line, Col;
    359   SourceLocation IncludeLoc;
    360 public:
    361   PresumedLoc() : Filename(nullptr) {}
    362   PresumedLoc(const char *FN, unsigned Ln, unsigned Co, SourceLocation IL)
    363     : Filename(FN), Line(Ln), Col(Co), IncludeLoc(IL) {
    364   }
    365 
    366   /// \brief Return true if this object is invalid or uninitialized.
    367   ///
    368   /// This occurs when created with invalid source locations or when walking
    369   /// off the top of a \#include stack.
    370   bool isInvalid() const { return Filename == nullptr; }
    371   bool isValid() const { return Filename != nullptr; }
    372 
    373   /// \brief Return the presumed filename of this location.
    374   ///
    375   /// This can be affected by \#line etc.
    376   const char *getFilename() const { return Filename; }
    377 
    378   /// \brief Return the presumed line number of this location.
    379   ///
    380   /// This can be affected by \#line etc.
    381   unsigned getLine() const { return Line; }
    382 
    383   /// \brief Return the presumed column number of this location.
    384   ///
    385   /// This cannot be affected by \#line, but is packaged here for convenience.
    386   unsigned getColumn() const { return Col; }
    387 
    388   /// \brief Return the presumed include location of this location.
    389   ///
    390   /// This can be affected by GNU linemarker directives.
    391   SourceLocation getIncludeLoc() const { return IncludeLoc; }
    392 };
    393 
    394 
    395 }  // end namespace clang
    396 
    397 namespace llvm {
    398   /// Define DenseMapInfo so that FileID's can be used as keys in DenseMap and
    399   /// DenseSets.
    400   template <>
    401   struct DenseMapInfo<clang::FileID> {
    402     static inline clang::FileID getEmptyKey() {
    403       return clang::FileID();
    404     }
    405     static inline clang::FileID getTombstoneKey() {
    406       return clang::FileID::getSentinel();
    407     }
    408 
    409     static unsigned getHashValue(clang::FileID S) {
    410       return S.getHashValue();
    411     }
    412 
    413     static bool isEqual(clang::FileID LHS, clang::FileID RHS) {
    414       return LHS == RHS;
    415     }
    416   };
    417 
    418   template <>
    419   struct isPodLike<clang::SourceLocation> { static const bool value = true; };
    420   template <>
    421   struct isPodLike<clang::FileID> { static const bool value = true; };
    422 
    423   // Teach SmallPtrSet how to handle SourceLocation.
    424   template<>
    425   class PointerLikeTypeTraits<clang::SourceLocation> {
    426   public:
    427     static inline void *getAsVoidPointer(clang::SourceLocation L) {
    428       return L.getPtrEncoding();
    429     }
    430     static inline clang::SourceLocation getFromVoidPointer(void *P) {
    431       return clang::SourceLocation::getFromRawEncoding((unsigned)(uintptr_t)P);
    432     }
    433     enum { NumLowBitsAvailable = 0 };
    434   };
    435 
    436 }  // end namespace llvm
    437 
    438 #endif
    439