SourceLocation.h revision bcc2a67e5180612417727cbdd8afd0f79fdf726d 
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;
68public:
69  enum {
70    // FileID Layout:
71    // bit 31: 0 -> FileID, 1 -> MacroID (invalid for FileID)
72    //     30...17 -> ChunkID of location, index into SourceManager table.
73    ChunkIDBits  = 14,
74    //      0...16 -> Index into the chunk of the specified ChunkID.
75    FilePosBits = 32-1-ChunkIDBits,
76
77    // MacroID Layout:
78    // bit 31: 1 -> MacroID, 0 -> FileID (invalid for MacroID)
79
80    // bit 29,30: unused.
81
82    // bits 28...9 -> MacroID number.
83    MacroIDBits       = 20,
84    // bits 8...0  -> Macro spelling offset
85    MacroSpellingOffsBits = 9,
86
87
88    // Useful constants.
89    ChunkSize = (1 << FilePosBits)
90  };
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  static SourceLocation getFileLoc(unsigned ChunkID, unsigned FilePos) {
106    SourceLocation L;
107    // If a FilePos is larger than (1<<FilePosBits), the SourceManager makes
108    // enough consequtive ChunkIDs that we have one for each chunk.
109    if (FilePos >= ChunkSize) {
110      ChunkID += FilePos >> FilePosBits;
111      FilePos &= ChunkSize-1;
112    }
113
114    // FIXME: Find a way to handle out of ChunkID bits!  Maybe MaxFileID is an
115    // escape of some sort?
116    assert(ChunkID < (1 << ChunkIDBits) && "Out of ChunkID's");
117
118    L.ID = (ChunkID << FilePosBits) | FilePos;
119    return L;
120  }
121public:
122
123  static bool isValidMacroSpellingOffs(int Val) {
124    if (Val >= 0)
125      return Val < (1 << (MacroSpellingOffsBits-1));
126    return -Val <= (1 << (MacroSpellingOffsBits-1));
127  }
128
129  static SourceLocation getMacroLoc(unsigned MacroID, int SpellingOffs) {
130    assert(MacroID < (1 << MacroIDBits) && "Too many macros!");
131    assert(isValidMacroSpellingOffs(SpellingOffs) &&"spelling offs too large!");
132
133    // Mask off sign bits.
134    SpellingOffs &= (1 << MacroSpellingOffsBits)-1;
135
136    SourceLocation L;
137    L.ID = (1 << 31) |
138           (MacroID << MacroSpellingOffsBits) |
139           SpellingOffs;
140    return L;
141  }
142
143
144  /// getChunkID - Return the chunk identifier for this SourceLocation.  This
145  /// ChunkID can be used with the SourceManager object to obtain an entire
146  /// include stack for a file position reference.
147  unsigned getChunkID() const {
148    assert(isFileID() && "can't get the file id of a non-file sloc!");
149    return ID >> FilePosBits;
150  }
151
152  /// getRawFilePos - Return the byte offset from the start of the file-chunk
153  /// referred to by ChunkID.  This method should not be used to get the offset
154  /// from the start of the file, instead you should use
155  /// SourceManager::getDecomposedFileLoc.  This method will be
156  //  incorrect for large files.
157  unsigned getRawFilePos() const {
158    assert(isFileID() && "can't get the file id of a non-file sloc!");
159    return ID & (ChunkSize-1);
160  }
161
162  unsigned getMacroID() const {
163    assert(isMacroID() && "Is not a macro id!");
164    return (ID >> MacroSpellingOffsBits) & ((1 << MacroIDBits)-1);
165  }
166
167  int getMacroSpellingOffs() const {
168    assert(isMacroID() && "Is not a macro id!");
169    int Val = ID & ((1 << MacroSpellingOffsBits)-1);
170    // Sign extend it properly.
171    unsigned ShAmt = sizeof(int)*8 - MacroSpellingOffsBits;
172    return (Val << ShAmt) >> ShAmt;
173  }
174
175  /// getFileLocWithOffset - Return a source location with the specified offset
176  /// from this file SourceLocation.
177  SourceLocation getFileLocWithOffset(int Offset) const {
178    unsigned ChunkID = getChunkID();
179    Offset += getRawFilePos();
180    // Handle negative offsets correctly.
181    while (Offset < 0) {
182      --ChunkID;
183      Offset += ChunkSize;
184    }
185    return getFileLoc(ChunkID, Offset);
186  }
187
188  /// getRawEncoding - When a SourceLocation itself cannot be used, this returns
189  /// an (opaque) 32-bit integer encoding for it.  This should only be passed
190  /// to SourceLocation::getFromRawEncoding, it should not be inspected
191  /// directly.
192  unsigned getRawEncoding() const { return ID; }
193
194
195  bool operator<(const SourceLocation &RHS) const {
196    return ID < RHS.ID;
197  }
198
199  /// getFromRawEncoding - Turn a raw encoding of a SourceLocation object into
200  /// a real SourceLocation.
201  static SourceLocation getFromRawEncoding(unsigned Encoding) {
202    SourceLocation X;
203    X.ID = Encoding;
204    return X;
205  }
206
207  /// Emit - Emit this SourceLocation object to Bitcode.
208  void Emit(llvm::Serializer& S) const;
209
210  /// ReadVal - Read a SourceLocation object from Bitcode.
211  static SourceLocation ReadVal(llvm::Deserializer& D);
212};
213
214inline bool operator==(const SourceLocation &LHS, const SourceLocation &RHS) {
215  return LHS.getRawEncoding() == RHS.getRawEncoding();
216}
217
218inline bool operator!=(const SourceLocation &LHS, const SourceLocation &RHS) {
219  return !(LHS == RHS);
220}
221
222/// SourceRange - a trival tuple used to represent a source range.
223class SourceRange {
224  SourceLocation B;
225  SourceLocation E;
226public:
227  SourceRange(): B(SourceLocation()), E(SourceLocation()) {}
228  SourceRange(SourceLocation loc) : B(loc), E(loc) {}
229  SourceRange(SourceLocation begin, SourceLocation end) : B(begin), E(end) {}
230
231  SourceLocation getBegin() const { return B; }
232  SourceLocation getEnd() const { return E; }
233
234  void setBegin(SourceLocation b) { B = b; }
235  void setEnd(SourceLocation e) { E = e; }
236
237  bool isValid() const { return B.isValid() && E.isValid(); }
238
239  /// Emit - Emit this SourceRange object to Bitcode.
240  void Emit(llvm::Serializer& S) const;
241
242  /// ReadVal - Read a SourceRange object from Bitcode.
243  static SourceRange ReadVal(llvm::Deserializer& D);
244};
245
246/// FullSourceLoc - A SourceLocation and its associated SourceManager.  Useful
247/// for argument passing to functions that expect both objects.
248class FullSourceLoc : public SourceLocation {
249  SourceManager* SrcMgr;
250public:
251  // Creates a FullSourceLoc where isValid() returns false.
252  explicit FullSourceLoc() : SrcMgr((SourceManager*) 0) {}
253
254  explicit FullSourceLoc(SourceLocation Loc, SourceManager &SM)
255    : SourceLocation(Loc), SrcMgr(&SM) {}
256
257  SourceManager& getManager() {
258    assert (SrcMgr && "SourceManager is NULL.");
259    return *SrcMgr;
260  }
261
262  const SourceManager& getManager() const {
263    assert (SrcMgr && "SourceManager is NULL.");
264    return *SrcMgr;
265  }
266
267  FileID getFileID() const;
268
269  FullSourceLoc getInstantiationLoc() const;
270  FullSourceLoc getSpellingLoc() const;
271  FullSourceLoc getIncludeLoc() const;
272
273  unsigned getLineNumber() const;
274  unsigned getColumnNumber() const;
275
276  unsigned getInstantiationLineNumber() const;
277  unsigned getInstantiationColumnNumber() const;
278
279  unsigned getSpellingLineNumber() const;
280  unsigned getSpellingColumnNumber() const;
281
282  const char *getCharacterData() const;
283
284  const llvm::MemoryBuffer* getBuffer() const;
285
286  const char* getSourceName() const;
287  const FileEntry* getFileEntryForLoc() const;
288
289  bool isInSystemHeader() const;
290
291  /// Prints information about this FullSourceLoc to stderr. Useful for
292  ///  debugging.
293  void dump() const;
294
295  friend inline bool
296  operator==(const FullSourceLoc &LHS, const FullSourceLoc &RHS) {
297    return LHS.getRawEncoding() == RHS.getRawEncoding() &&
298          LHS.SrcMgr == RHS.SrcMgr;
299  }
300
301  friend inline bool
302  operator!=(const FullSourceLoc &LHS, const FullSourceLoc &RHS) {
303    return !(LHS == RHS);
304  }
305
306};
307
308}  // end namespace clang
309
310namespace llvm {
311  /// Define DenseMapInfo so that FileID's can be used as keys in DenseMap and
312  /// DenseSets.
313  template <>
314  struct DenseMapInfo<clang::FileID> {
315    static inline clang::FileID getEmptyKey() {
316      return clang::FileID();
317    }
318    static inline clang::FileID getTombstoneKey() {
319      return clang::FileID::getSentinel();
320    }
321
322    static unsigned getHashValue(clang::FileID S) {
323      return S.getHashValue();
324    }
325
326    static bool isEqual(clang::FileID LHS, clang::FileID RHS) {
327      return LHS == RHS;
328    }
329
330    static bool isPod() { return true; }
331  };
332
333}  // end namespace llvm
334
335#endif
336