SourceLocation.h revision 6fda54c19321673965536b0a8f7236f635cf9730 
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 <cassert>
18#include "llvm/Bitcode/SerializationFwd.h"
19
20namespace llvm {
21  class MemoryBuffer;
22  template <typename T> struct DenseMapInfo;
23}
24
25namespace clang {
26
27class SourceManager;
28class FileEntry;
29
30/// FileID - This is an opaque identifier used by SourceManager which refers to
31/// a source file (MemoryBuffer) along with its #include path and #line data.
32///
33class FileID {
34  /// ID - Opaque identifier, 0 is "invalid".
35  unsigned ID;
36public:
37  FileID() : ID(0) {}
38
39  bool isInvalid() const { return ID == 0; }
40
41  bool operator==(const FileID &RHS) const { return ID == RHS.ID; }
42  bool operator<(const FileID &RHS) const { return ID < RHS.ID; }
43  bool operator<=(const FileID &RHS) const { return ID <= RHS.ID; }
44  bool operator!=(const FileID &RHS) const { return !(*this == RHS); }
45  bool operator>(const FileID &RHS) const { return RHS < *this; }
46  bool operator>=(const FileID &RHS) const { return RHS <= *this; }
47
48  static FileID getSentinel() { return Create(~0U); }
49  unsigned getHashValue() const { return ID; }
50
51private:
52  friend class SourceManager;
53  static FileID Create(unsigned V) {
54    FileID F;
55    F.ID = V;
56    return F;
57  }
58  unsigned getOpaqueValue() const { return ID; }
59};
60
61
62/// SourceLocation - This is a carefully crafted 32-bit identifier that encodes
63/// a full include stack, line and column number information for a position in
64/// an input translation unit.
65class SourceLocation {
66  unsigned ID;
67  friend class SourceManager;
68  enum {
69    // FileID Layout:
70    // bit 31: 0 -> FileID, 1 -> MacroID (invalid for FileID)
71    //     30...17 -> ChunkID of location, index into SourceManager table.
72    ChunkIDBits  = 14,
73    //      0...16 -> Index into the chunk of the specified ChunkID.
74    FilePosBits = 32-1-ChunkIDBits,
75
76    // MacroID Layout:
77    // bit 31: 1 -> MacroID, 0 -> FileID (invalid for MacroID)
78
79    // bit 29,30: unused.
80
81    // bits 28...9 -> MacroID number.
82    MacroIDBits       = 20,
83    // bits 8...0  -> Macro spelling offset
84    MacroSpellingOffsBits = 9,
85
86
87    // Useful constants.
88    ChunkSize = (1 << FilePosBits)
89  };
90public:
91
92  SourceLocation() : ID(0) {}  // 0 is an invalid FileID.
93
94  bool isFileID() const { return (ID >> 31) == 0; }
95  bool isMacroID() const { return (ID >> 31) != 0; }
96
97  /// isValid - Return true if this is a valid SourceLocation object.  Invalid
98  /// SourceLocations are often used when events have no corresponding location
99  /// in the source (e.g. a diagnostic is required for a command line option).
100  ///
101  bool isValid() const { return ID != 0; }
102  bool isInvalid() const { return ID == 0; }
103
104private:
105  /// getChunkID - Return the chunk identifier for this SourceLocation.  This
106  /// ChunkID can be used with the SourceManager object to obtain an entire
107  /// include stack for a file position reference.
108  unsigned getChunkID() const {
109    assert(isFileID() && "can't get the file id of a non-file sloc!");
110    return ID >> FilePosBits;
111  }
112
113  unsigned getMacroID() const {
114    assert(isMacroID() && "Is not a macro id!");
115    return (ID >> MacroSpellingOffsBits) & ((1 << MacroIDBits)-1);
116  }
117
118  static SourceLocation getFileLoc(unsigned ChunkID, unsigned FilePos) {
119    SourceLocation L;
120    // If a FilePos is larger than (1<<FilePosBits), the SourceManager makes
121    // enough consequtive ChunkIDs that we have one for each chunk.
122    if (FilePos >= ChunkSize) {
123      ChunkID += FilePos >> FilePosBits;
124      FilePos &= ChunkSize-1;
125    }
126
127    // FIXME: Find a way to handle out of ChunkID bits!  Maybe MaxFileID is an
128    // escape of some sort?
129    assert(ChunkID < (1 << ChunkIDBits) && "Out of ChunkID's");
130
131    L.ID = (ChunkID << FilePosBits) | FilePos;
132    return L;
133  }
134
135  static bool isValidMacroSpellingOffs(int Val) {
136    if (Val >= 0)
137      return Val < (1 << (MacroSpellingOffsBits-1));
138    return -Val <= (1 << (MacroSpellingOffsBits-1));
139  }
140
141  static SourceLocation getMacroLoc(unsigned MacroID, int SpellingOffs) {
142    assert(MacroID < (1 << MacroIDBits) && "Too many macros!");
143    assert(isValidMacroSpellingOffs(SpellingOffs) &&"spelling offs too large!");
144
145    // Mask off sign bits.
146    SpellingOffs &= (1 << MacroSpellingOffsBits)-1;
147
148    SourceLocation L;
149    L.ID = (1 << 31) |
150           (MacroID << MacroSpellingOffsBits) |
151           SpellingOffs;
152    return L;
153  }
154
155  /// getRawFilePos - Return the byte offset from the start of the file-chunk
156  /// referred to by ChunkID.  This method should not be used to get the offset
157  /// from the start of the file, instead you should use
158  /// SourceManager::getDecomposedFileLoc.  This method will be
159  //  incorrect for large files.
160  unsigned getRawFilePos() const {
161    assert(isFileID() && "can't get the file id of a non-file sloc!");
162    return ID & (ChunkSize-1);
163  }
164
165  int getMacroSpellingOffs() const {
166    assert(isMacroID() && "Is not a macro id!");
167    int Val = ID & ((1 << MacroSpellingOffsBits)-1);
168    // Sign extend it properly.
169    unsigned ShAmt = sizeof(int)*8 - MacroSpellingOffsBits;
170    return (Val << ShAmt) >> ShAmt;
171  }
172public:
173
174  /// getFileLocWithOffset - Return a source location with the specified offset
175  /// from this file SourceLocation.
176  SourceLocation getFileLocWithOffset(int Offset) const {
177    unsigned ChunkID = getChunkID();
178    Offset += getRawFilePos();
179    // Handle negative offsets correctly.
180    while (Offset < 0) {
181      --ChunkID;
182      Offset += ChunkSize;
183    }
184    return getFileLoc(ChunkID, Offset);
185  }
186
187  /// getRawEncoding - When a SourceLocation itself cannot be used, this returns
188  /// an (opaque) 32-bit integer encoding for it.  This should only be passed
189  /// to SourceLocation::getFromRawEncoding, it should not be inspected
190  /// directly.
191  unsigned getRawEncoding() const { return ID; }
192
193
194  /// getFromRawEncoding - Turn a raw encoding of a SourceLocation object into
195  /// a real SourceLocation.
196  static SourceLocation getFromRawEncoding(unsigned Encoding) {
197    SourceLocation X;
198    X.ID = Encoding;
199    return X;
200  }
201
202  /// Emit - Emit this SourceLocation object to Bitcode.
203  void Emit(llvm::Serializer& S) const;
204
205  /// ReadVal - Read a SourceLocation object from Bitcode.
206  static SourceLocation ReadVal(llvm::Deserializer& D);
207};
208
209inline bool operator==(const SourceLocation &LHS, const SourceLocation &RHS) {
210  return LHS.getRawEncoding() == RHS.getRawEncoding();
211}
212
213inline bool operator!=(const SourceLocation &LHS, const SourceLocation &RHS) {
214  return !(LHS == RHS);
215}
216
217inline bool operator<(const SourceLocation &LHS, const SourceLocation &RHS) {
218  return LHS.getRawEncoding() < RHS.getRawEncoding();
219}
220
221/// SourceRange - a trival tuple used to represent a source range.
222class SourceRange {
223  SourceLocation B;
224  SourceLocation E;
225public:
226  SourceRange(): B(SourceLocation()), E(SourceLocation()) {}
227  SourceRange(SourceLocation loc) : B(loc), E(loc) {}
228  SourceRange(SourceLocation begin, SourceLocation end) : B(begin), E(end) {}
229
230  SourceLocation getBegin() const { return B; }
231  SourceLocation getEnd() const { return E; }
232
233  void setBegin(SourceLocation b) { B = b; }
234  void setEnd(SourceLocation e) { E = e; }
235
236  bool isValid() const { return B.isValid() && E.isValid(); }
237
238  /// Emit - Emit this SourceRange object to Bitcode.
239  void Emit(llvm::Serializer& S) const;
240
241  /// ReadVal - Read a SourceRange object from Bitcode.
242  static SourceRange ReadVal(llvm::Deserializer& D);
243};
244
245/// FullSourceLoc - A SourceLocation and its associated SourceManager.  Useful
246/// for argument passing to functions that expect both objects.
247class FullSourceLoc : public SourceLocation {
248  SourceManager* SrcMgr;
249public:
250  // Creates a FullSourceLoc where isValid() returns false.
251  explicit FullSourceLoc() : SrcMgr((SourceManager*) 0) {}
252
253  explicit FullSourceLoc(SourceLocation Loc, SourceManager &SM)
254    : SourceLocation(Loc), SrcMgr(&SM) {}
255
256  SourceManager& getManager() {
257    assert (SrcMgr && "SourceManager is NULL.");
258    return *SrcMgr;
259  }
260
261  const SourceManager& getManager() const {
262    assert (SrcMgr && "SourceManager is NULL.");
263    return *SrcMgr;
264  }
265
266  FileID getFileID() const;
267
268  FullSourceLoc getInstantiationLoc() const;
269  FullSourceLoc getSpellingLoc() const;
270  FullSourceLoc getIncludeLoc() const;
271
272  unsigned getLineNumber() const;
273  unsigned getColumnNumber() const;
274
275  unsigned getInstantiationLineNumber() const;
276  unsigned getInstantiationColumnNumber() const;
277
278  unsigned getSpellingLineNumber() const;
279  unsigned getSpellingColumnNumber() const;
280
281  const char *getCharacterData() const;
282
283  const llvm::MemoryBuffer* getBuffer() const;
284
285  const char* getSourceName() const;
286  const FileEntry* getFileEntryForLoc() const;
287
288  bool isInSystemHeader() const;
289
290  /// Prints information about this FullSourceLoc to stderr. Useful for
291  ///  debugging.
292  void dump() const;
293
294  friend inline bool
295  operator==(const FullSourceLoc &LHS, const FullSourceLoc &RHS) {
296    return LHS.getRawEncoding() == RHS.getRawEncoding() &&
297          LHS.SrcMgr == RHS.SrcMgr;
298  }
299
300  friend inline bool
301  operator!=(const FullSourceLoc &LHS, const FullSourceLoc &RHS) {
302    return !(LHS == RHS);
303  }
304
305};
306
307}  // end namespace clang
308
309namespace llvm {
310  /// Define DenseMapInfo so that FileID's can be used as keys in DenseMap and
311  /// DenseSets.
312  template <>
313  struct DenseMapInfo<clang::FileID> {
314    static inline clang::FileID getEmptyKey() {
315      return clang::FileID();
316    }
317    static inline clang::FileID getTombstoneKey() {
318      return clang::FileID::getSentinel();
319    }
320
321    static unsigned getHashValue(clang::FileID S) {
322      return S.getHashValue();
323    }
324
325    static bool isEqual(clang::FileID LHS, clang::FileID RHS) {
326      return LHS == RHS;
327    }
328
329    static bool isPod() { return true; }
330  };
331
332}  // end namespace llvm
333
334#endif
335