summaryrefslogtreecommitdiffstats
path: root/include/clang/Basic/SourceManager.h
blob: d1239694fc16b39fef5950ba7f43afeb5c6371ff (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
//===--- SourceManager.h - Track and cache source files ---------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//  This file defines the SourceManager interface.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_SOURCEMANAGER_H
#define LLVM_CLANG_SOURCEMANAGER_H

#include "clang/Basic/SourceLocation.h"
#include "llvm/Support/Allocator.h"
#include "llvm/System/DataTypes.h"
#include "llvm/ADT/PointerIntPair.h"
#include "llvm/ADT/PointerUnion.h"
#include "llvm/ADT/DenseMap.h"
#include <vector>
#include <cassert>

namespace llvm {
class MemoryBuffer;
class StringRef;
}

namespace clang {

class Diagnostic;
class SourceManager;
class FileManager;
class FileEntry;
class LineTableInfo;
  
/// SrcMgr - Public enums and private classes that are part of the
/// SourceManager implementation.
///
namespace SrcMgr {
  /// CharacteristicKind - This is used to represent whether a file or directory
  /// holds normal user code, system code, or system code which is implicitly
  /// 'extern "C"' in C++ mode.  Entire directories can be tagged with this
  /// (this is maintained by DirectoryLookup and friends) as can specific
  /// FileIDInfos when a #pragma system_header is seen or various other cases.
  ///
  enum CharacteristicKind {
    C_User, C_System, C_ExternCSystem
  };

  /// ContentCache - Once instance of this struct is kept for every file
  /// loaded or used.  This object owns the MemoryBuffer object.
  class ContentCache {
    /// Buffer - The actual buffer containing the characters from the input
    /// file.  This is owned by the ContentCache object.
    /// The bit indicates whether the buffer is invalid.
    mutable llvm::PointerIntPair<const llvm::MemoryBuffer *, 1, bool> Buffer;

  public:
    /// Reference to the file entry.  This reference does not own
    /// the FileEntry object.  It is possible for this to be NULL if
    /// the ContentCache encapsulates an imaginary text buffer.
    const FileEntry *Entry;

    /// SourceLineCache - A bump pointer allocated array of offsets for each
    /// source line.  This is lazily computed.  This is owned by the
    /// SourceManager BumpPointerAllocator object.
    unsigned *SourceLineCache;

    /// NumLines - The number of lines in this ContentCache.  This is only valid
    /// if SourceLineCache is non-null.
    unsigned NumLines;

    /// getBuffer - Returns the memory buffer for the associated content.
    ///
    /// \param Diag Object through which diagnostics will be emitted it the
    /// buffer cannot be retrieved.
    /// 
    /// \param Invalid If non-NULL, will be set \c true if an error occurred.
    const llvm::MemoryBuffer *getBuffer(Diagnostic &Diag, 
                                        bool *Invalid = 0) const;

    /// getSize - Returns the size of the content encapsulated by this
    ///  ContentCache. This can be the size of the source file or the size of an
    ///  arbitrary scratch buffer.  If the ContentCache encapsulates a source
    ///  file this size is retrieved from the file's FileEntry.
    unsigned getSize() const;

    /// getSizeBytesMapped - Returns the number of bytes actually mapped for
    ///  this ContentCache.  This can be 0 if the MemBuffer was not actually
    ///  instantiated.
    unsigned getSizeBytesMapped() const;

    void setBuffer(const llvm::MemoryBuffer *B) {
      assert(!Buffer.getPointer() && "MemoryBuffer already set.");
      Buffer.setPointer(B);
      Buffer.setInt(false);
    }

    /// \brief Replace the existing buffer (which will be deleted)
    /// with the given buffer.
    void replaceBuffer(const llvm::MemoryBuffer *B);

    ContentCache(const FileEntry *Ent = 0)
      : Buffer(0, false), Entry(Ent), SourceLineCache(0), NumLines(0) {}

    ~ContentCache();

    /// The copy ctor does not allow copies where source object has either
    ///  a non-NULL Buffer or SourceLineCache.  Ownership of allocated memory
    ///  is not transfered, so this is a logical error.
    ContentCache(const ContentCache &RHS) 
      : Buffer(0, false), SourceLineCache(0) 
    {
      Entry = RHS.Entry;

      assert (RHS.Buffer.getPointer() == 0 && RHS.SourceLineCache == 0
              && "Passed ContentCache object cannot own a buffer.");

      NumLines = RHS.NumLines;
    }

  private:
    // Disable assignments.
    ContentCache &operator=(const ContentCache& RHS);
  };

  /// FileInfo - Information about a FileID, basically just the logical file
  /// that it represents and include stack information.
  ///
  /// Each FileInfo has include stack information, indicating where it came
  /// from.  This information encodes the #include chain that a token was
  /// instantiated from.  The main include file has an invalid IncludeLoc.
  ///
  /// FileInfos contain a "ContentCache *", with the contents of the file.
  ///
  class FileInfo {
    /// IncludeLoc - The location of the #include that brought in this file.
    /// This is an invalid SLOC for the main file (top of the #include chain).
    unsigned IncludeLoc;  // Really a SourceLocation

    /// Data - This contains the ContentCache* and the bits indicating the
    /// characteristic of the file and whether it has #line info, all bitmangled
    /// together.
    uintptr_t Data;
  public:
    /// get - Return a FileInfo object.
    static FileInfo get(SourceLocation IL, const ContentCache *Con,
                        CharacteristicKind FileCharacter) {
      FileInfo X;
      X.IncludeLoc = IL.getRawEncoding();
      X.Data = (uintptr_t)Con;
      assert((X.Data & 7) == 0 &&"ContentCache pointer insufficiently aligned");
      assert((unsigned)FileCharacter < 4 && "invalid file character");
      X.Data |= (unsigned)FileCharacter;
      return X;
    }

    SourceLocation getIncludeLoc() const {
      return SourceLocation::getFromRawEncoding(IncludeLoc);
    }
    const ContentCache* getContentCache() const {
      return reinterpret_cast<const ContentCache*>(Data & ~7UL);
    }

    /// getCharacteristic - Return whether this is a system header or not.
    CharacteristicKind getFileCharacteristic() const {
      return (CharacteristicKind)(Data & 3);
    }

    /// hasLineDirectives - Return true if this FileID has #line directives in
    /// it.
    bool hasLineDirectives() const { return (Data & 4) != 0; }

    /// setHasLineDirectives - Set the flag that indicates that this FileID has
    /// line table entries associated with it.
    void setHasLineDirectives() {
      Data |= 4;
    }
  };

  /// InstantiationInfo - Each InstantiationInfo encodes the Instantiation
  /// location - where the token was ultimately instantiated, and the
  /// SpellingLoc - where the actual character data for the token came from.
  class InstantiationInfo {
     // Really these are all SourceLocations.

    /// SpellingLoc - Where the spelling for the token can be found.
    unsigned SpellingLoc;

    /// InstantiationLocStart/InstantiationLocEnd - In a macro expansion, these
    /// indicate the start and end of the instantiation.  In object-like macros,
    /// these will be the same.  In a function-like macro instantiation, the
    /// start will be the identifier and the end will be the ')'.
    unsigned InstantiationLocStart, InstantiationLocEnd;
  public:
    SourceLocation getSpellingLoc() const {
      return SourceLocation::getFromRawEncoding(SpellingLoc);
    }
    SourceLocation getInstantiationLocStart() const {
      return SourceLocation::getFromRawEncoding(InstantiationLocStart);
    }
    SourceLocation getInstantiationLocEnd() const {
      return SourceLocation::getFromRawEncoding(InstantiationLocEnd);
    }

    std::pair<SourceLocation,SourceLocation> getInstantiationLocRange() const {
      return std::make_pair(getInstantiationLocStart(),
                            getInstantiationLocEnd());
    }

    /// get - Return a InstantiationInfo for an expansion.  IL specifies
    /// the instantiation location (where the macro is expanded), and SL
    /// specifies the spelling location (where the characters from the token
    /// come from).  IL and PL can both refer to normal File SLocs or
    /// instantiation locations.
    static InstantiationInfo get(SourceLocation ILStart, SourceLocation ILEnd,
                                 SourceLocation SL) {
      InstantiationInfo X;
      X.SpellingLoc = SL.getRawEncoding();
      X.InstantiationLocStart = ILStart.getRawEncoding();
      X.InstantiationLocEnd = ILEnd.getRawEncoding();
      return X;
    }
  };

  /// SLocEntry - This is a discriminated union of FileInfo and
  /// InstantiationInfo.  SourceManager keeps an array of these objects, and
  /// they are uniquely identified by the FileID datatype.
  class SLocEntry {
    unsigned Offset;   // low bit is set for instantiation info.
    union {
      FileInfo File;
      InstantiationInfo Instantiation;
    };
  public:
    unsigned getOffset() const { return Offset >> 1; }

    bool isInstantiation() const { return Offset & 1; }
    bool isFile() const { return !isInstantiation(); }

    const FileInfo &getFile() const {
      assert(isFile() && "Not a file SLocEntry!");
      return File;
    }

    const InstantiationInfo &getInstantiation() const {
      assert(isInstantiation() && "Not an instantiation SLocEntry!");
      return Instantiation;
    }

    static SLocEntry get(unsigned Offset, const FileInfo &FI) {
      SLocEntry E;
      E.Offset = Offset << 1;
      E.File = FI;
      return E;
    }

    static SLocEntry get(unsigned Offset, const InstantiationInfo &II) {
      SLocEntry E;
      E.Offset = (Offset << 1) | 1;
      E.Instantiation = II;
      return E;
    }
  };
}  // end SrcMgr namespace.

/// \brief External source of source location entries.
class ExternalSLocEntrySource {
public:
  virtual ~ExternalSLocEntrySource();

  /// \brief Read the source location entry with index ID.
  virtual void ReadSLocEntry(unsigned ID) = 0;
};

/// SourceManager - This file handles loading and caching of source files into
/// memory.  This object owns the MemoryBuffer objects for all of the loaded
/// files and assigns unique FileID's for each unique #include chain.
///
/// The SourceManager can be queried for information about SourceLocation
/// objects, turning them into either spelling or instantiation locations.
/// Spelling locations represent where the bytes corresponding to a token came
/// from and instantiation locations represent where the location is in the
/// user's view.  In the case of a macro expansion, for example, the spelling
/// location indicates where the expanded token came from and the instantiation
/// location specifies where it was expanded.
class SourceManager {
  /// \brief Diagnostic object.
  Diagnostic &Diag;
  
  mutable llvm::BumpPtrAllocator ContentCacheAlloc;

  /// FileInfos - Memoized information about all of the files tracked by this
  /// SourceManager.  This set allows us to merge ContentCache entries based
  /// on their FileEntry*.  All ContentCache objects will thus have unique,
  /// non-null, FileEntry pointers.
  llvm::DenseMap<const FileEntry*, SrcMgr::ContentCache*> FileInfos;

  /// MemBufferInfos - Information about various memory buffers that we have
  /// read in.  All FileEntry* within the stored ContentCache objects are NULL,
  /// as they do not refer to a file.
  std::vector<SrcMgr::ContentCache*> MemBufferInfos;

  /// SLocEntryTable - This is an array of SLocEntry's that we have created.
  /// FileID is an index into this vector.  This array is sorted by the offset.
  std::vector<SrcMgr::SLocEntry> SLocEntryTable;
  /// NextOffset - This is the next available offset that a new SLocEntry can
  /// start at.  It is SLocEntryTable.back().getOffset()+size of back() entry.
  unsigned NextOffset;

  /// \brief If source location entries are being lazily loaded from
  /// an external source, this vector indicates whether the Ith source
  /// location entry has already been loaded from the external storage.
  std::vector<bool> SLocEntryLoaded;

  /// \brief An external source for source location entries.
  ExternalSLocEntrySource *ExternalSLocEntries;

  /// LastFileIDLookup - This is a one-entry cache to speed up getFileID.
  /// LastFileIDLookup records the last FileID looked up or created, because it
  /// is very common to look up many tokens from the same file.
  mutable FileID LastFileIDLookup;

  /// LineTable - This holds information for #line directives.  It is referenced
  /// by indices from SLocEntryTable.
  LineTableInfo *LineTable;

  /// LastLineNo - These ivars serve as a cache used in the getLineNumber
  /// method which is used to speedup getLineNumber calls to nearby locations.
  mutable FileID LastLineNoFileIDQuery;
  mutable SrcMgr::ContentCache *LastLineNoContentCache;
  mutable unsigned LastLineNoFilePos;
  mutable unsigned LastLineNoResult;

  /// MainFileID - The file ID for the main source file of the translation unit.
  FileID MainFileID;

  // Statistics for -print-stats.
  mutable unsigned NumLinearScans, NumBinaryProbes;

  // Cache results for the isBeforeInTranslationUnit method.
  mutable FileID LastLFIDForBeforeTUCheck;
  mutable FileID LastRFIDForBeforeTUCheck;
  mutable bool   LastResForBeforeTUCheck;

  // SourceManager doesn't support copy construction.
  explicit SourceManager(const SourceManager&);
  void operator=(const SourceManager&);
public:
  SourceManager(Diagnostic &Diag)
    : Diag(Diag), ExternalSLocEntries(0), LineTable(0), NumLinearScans(0),
      NumBinaryProbes(0) {
    clearIDTables();
  }
  ~SourceManager();

  void clearIDTables();

  //===--------------------------------------------------------------------===//
  // MainFileID creation and querying methods.
  //===--------------------------------------------------------------------===//

  /// getMainFileID - Returns the FileID of the main source file.
  FileID getMainFileID() const { return MainFileID; }

  /// createMainFileID - Create the FileID for the main source file.
  FileID createMainFileID(const FileEntry *SourceFile,
                          SourceLocation IncludePos) {
    assert(MainFileID.isInvalid() && "MainFileID already set!");
    MainFileID = createFileID(SourceFile, IncludePos, SrcMgr::C_User);
    return MainFileID;
  }

  //===--------------------------------------------------------------------===//
  // Methods to create new FileID's and instantiations.
  //===--------------------------------------------------------------------===//

  /// createFileID - Create a new FileID that represents the specified file
  /// being #included from the specified IncludePosition.  This returns 0 on
  /// error and translates NULL into standard input.
  /// PreallocateID should be non-zero to specify which a pre-allocated,
  /// lazily computed source location is being filled in by this operation.
  FileID createFileID(const FileEntry *SourceFile, SourceLocation IncludePos,
                      SrcMgr::CharacteristicKind FileCharacter,
                      unsigned PreallocatedID = 0,
                      unsigned Offset = 0) {
    const SrcMgr::ContentCache *IR = getOrCreateContentCache(SourceFile);
    if (IR == 0) return FileID();    // Error opening file?
    return createFileID(IR, IncludePos, FileCharacter, PreallocatedID, Offset);
  }

  /// createFileIDForMemBuffer - Create a new FileID that represents the
  /// specified memory buffer.  This does no caching of the buffer and takes
  /// ownership of the MemoryBuffer, so only pass a MemoryBuffer to this once.
  FileID createFileIDForMemBuffer(const llvm::MemoryBuffer *Buffer,
                                  unsigned PreallocatedID = 0,
                                  unsigned Offset = 0) {
    return createFileID(createMemBufferContentCache(Buffer), SourceLocation(),
                        SrcMgr::C_User, PreallocatedID, Offset);
  }

  /// createMainFileIDForMembuffer - Create the FileID for a memory buffer
  ///  that will represent the FileID for the main source.  One example
  ///  of when this would be used is when the main source is read from STDIN.
  FileID createMainFileIDForMemBuffer(const llvm::MemoryBuffer *Buffer) {
    assert(MainFileID.isInvalid() && "MainFileID already set!");
    MainFileID = createFileIDForMemBuffer(Buffer);
    return MainFileID;
  }

  /// createInstantiationLoc - Return a new SourceLocation that encodes the fact
  /// that a token at Loc should actually be referenced from InstantiationLoc.
  /// TokLength is the length of the token being instantiated.
  SourceLocation createInstantiationLoc(SourceLocation Loc,
                                        SourceLocation InstantiationLocStart,
                                        SourceLocation InstantiationLocEnd,
                                        unsigned TokLength,
                                        unsigned PreallocatedID = 0,
                                        unsigned Offset = 0);

  /// \brief Retrieve the memory buffer associated with the given file.
  ///
  /// \param Invalid If non-NULL, will be set \c true if an error
  /// occurs while retrieving the memory buffer.
  const llvm::MemoryBuffer *getMemoryBufferForFile(const FileEntry *File,
                                                   bool *Invalid = 0);

  /// \brief Override the contents of the given source file by providing an
  /// already-allocated buffer.
  ///
  /// \param SourceFile the source file whose contents will be override.
  ///
  /// \param Buffer the memory buffer whose contents will be used as the
  /// data in the given source file.
  ///
  /// \returns true if an error occurred, false otherwise.
  bool overrideFileContents(const FileEntry *SourceFile,
                            const llvm::MemoryBuffer *Buffer);

  //===--------------------------------------------------------------------===//
  // FileID manipulation methods.
  //===--------------------------------------------------------------------===//

  /// getBuffer - Return the buffer for the specified FileID. If there is an
  /// error opening this buffer the first time, this manufactures a temporary
  /// buffer and returns a non-empty error string.
  const llvm::MemoryBuffer *getBuffer(FileID FID, bool *Invalid = 0) const {
    return getSLocEntry(FID).getFile().getContentCache()->getBuffer(Diag,
                                                                    Invalid);
  }

  /// getFileEntryForID - Returns the FileEntry record for the provided FileID.
  const FileEntry *getFileEntryForID(FileID FID) const {
    return getSLocEntry(FID).getFile().getContentCache()->Entry;
  }

  /// getBufferData - Return a StringRef to the source buffer data for the
  /// specified FileID.
  ///
  /// \param FID The file ID whose contents will be returned.
  /// \param Invalid If non-NULL, will be set true if an error occurred.
  llvm::StringRef getBufferData(FileID FID, bool *Invalid = 0) const;


  //===--------------------------------------------------------------------===//
  // SourceLocation manipulation methods.
  //===--------------------------------------------------------------------===//

  /// getFileID - Return the FileID for a SourceLocation.  This is a very
  /// hot method that is used for all SourceManager queries that start with a
  /// SourceLocation object.  It is responsible for finding the entry in
  /// SLocEntryTable which contains the specified location.
  ///
  FileID getFileID(SourceLocation SpellingLoc) const {
    unsigned SLocOffset = SpellingLoc.getOffset();

    // If our one-entry cache covers this offset, just return it.
    if (isOffsetInFileID(LastFileIDLookup, SLocOffset))
      return LastFileIDLookup;

    return getFileIDSlow(SLocOffset);
  }

  /// getLocForStartOfFile - Return the source location corresponding to the
  /// first byte of the specified file.
  SourceLocation getLocForStartOfFile(FileID FID) const {
    assert(FID.ID < SLocEntryTable.size() && "FileID out of range");
    assert(getSLocEntry(FID).isFile() && "FileID is not a file");
    unsigned FileOffset = getSLocEntry(FID).getOffset();
    return SourceLocation::getFileLoc(FileOffset);
  }

  /// getInstantiationLoc - Given a SourceLocation object, return the
  /// instantiation location referenced by the ID.
  SourceLocation getInstantiationLoc(SourceLocation Loc) const {
    // Handle the non-mapped case inline, defer to out of line code to handle
    // instantiations.
    if (Loc.isFileID()) return Loc;
    return getInstantiationLocSlowCase(Loc);
  }

  /// getImmediateInstantiationRange - Loc is required to be an instantiation
  /// location.  Return the start/end of the instantiation information.
  std::pair<SourceLocation,SourceLocation>
  getImmediateInstantiationRange(SourceLocation Loc) const;

  /// getInstantiationRange - Given a SourceLocation object, return the
  /// range of tokens covered by the instantiation in the ultimate file.
  std::pair<SourceLocation,SourceLocation>
  getInstantiationRange(SourceLocation Loc) const;


  /// getSpellingLoc - Given a SourceLocation object, return the spelling
  /// location referenced by the ID.  This is the place where the characters
  /// that make up the lexed token can be found.
  SourceLocation getSpellingLoc(SourceLocation Loc) const {
    // Handle the non-mapped case inline, defer to out of line code to handle
    // instantiations.
    if (Loc.isFileID()) return Loc;
    return getSpellingLocSlowCase(Loc);
  }

  /// getImmediateSpellingLoc - Given a SourceLocation object, return the
  /// spelling location referenced by the ID.  This is the first level down
  /// towards the place where the characters that make up the lexed token can be
  /// found.  This should not generally be used by clients.
  SourceLocation getImmediateSpellingLoc(SourceLocation Loc) const;

  /// getDecomposedLoc - Decompose the specified location into a raw FileID +
  /// Offset pair.  The first element is the FileID, the second is the
  /// offset from the start of the buffer of the location.
  std::pair<FileID, unsigned> getDecomposedLoc(SourceLocation Loc) const {
    FileID FID = getFileID(Loc);
    return std::make_pair(FID, Loc.getOffset()-getSLocEntry(FID).getOffset());
  }

  /// getDecomposedInstantiationLoc - Decompose the specified location into a
  /// raw FileID + Offset pair.  If the location is an instantiation record,
  /// walk through it until we find the final location instantiated.
  std::pair<FileID, unsigned>
  getDecomposedInstantiationLoc(SourceLocation Loc) const {
    FileID FID = getFileID(Loc);
    const SrcMgr::SLocEntry *E = &getSLocEntry(FID);

    unsigned Offset = Loc.getOffset()-E->getOffset();
    if (Loc.isFileID())
      return std::make_pair(FID, Offset);

    return getDecomposedInstantiationLocSlowCase(E, Offset);
  }

  /// getDecomposedSpellingLoc - Decompose the specified location into a raw
  /// FileID + Offset pair.  If the location is an instantiation record, walk
  /// through it until we find its spelling record.
  std::pair<FileID, unsigned>
  getDecomposedSpellingLoc(SourceLocation Loc) const {
    FileID FID = getFileID(Loc);
    const SrcMgr::SLocEntry *E = &getSLocEntry(FID);

    unsigned Offset = Loc.getOffset()-E->getOffset();
    if (Loc.isFileID())
      return std::make_pair(FID, Offset);
    return getDecomposedSpellingLocSlowCase(E, Offset);
  }

  /// getFileOffset - This method returns the offset from the start
  /// of the file that the specified SourceLocation represents. This is not very
  /// meaningful for a macro ID.
  unsigned getFileOffset(SourceLocation SpellingLoc) const {
    return getDecomposedLoc(SpellingLoc).second;
  }


  //===--------------------------------------------------------------------===//
  // Queries about the code at a SourceLocation.
  //===--------------------------------------------------------------------===//

  /// getCharacterData - Return a pointer to the start of the specified location
  /// in the appropriate spelling MemoryBuffer.
  ///
  /// \param Invalid If non-NULL, will be set \c true if an error occurs.
  const char *getCharacterData(SourceLocation SL, bool *Invalid = 0) const;

  /// getColumnNumber - Return the column # for the specified file position.
  /// This is significantly cheaper to compute than the line number.  This
  /// returns zero if the column number isn't known.  This may only be called on
  /// a file sloc, so you must choose a spelling or instantiation location
  /// before calling this method.
  unsigned getColumnNumber(FileID FID, unsigned FilePos, 
                           bool *Invalid = 0) const;
  unsigned getSpellingColumnNumber(SourceLocation Loc,
                                   bool *Invalid = 0) const;
  unsigned getInstantiationColumnNumber(SourceLocation Loc,
                                        bool *Invalid = 0) const;


  /// getLineNumber - Given a SourceLocation, return the spelling line number
  /// for the position indicated.  This requires building and caching a table of
  /// line offsets for the MemoryBuffer, so this is not cheap: use only when
  /// about to emit a diagnostic.
  unsigned getLineNumber(FileID FID, unsigned FilePos, bool *Invalid = 0) const;

  unsigned getInstantiationLineNumber(SourceLocation Loc, 
                                      bool *Invalid = 0) const;
  unsigned getSpellingLineNumber(SourceLocation Loc, bool *Invalid = 0) const;

  /// Return the filename or buffer identifier of the buffer the location is in.
  /// Note that this name does not respect #line directives.  Use getPresumedLoc
  /// for normal clients.
  const char *getBufferName(SourceLocation Loc, bool *Invalid = 0) const;

  /// getFileCharacteristic - return the file characteristic of the specified
  /// source location, indicating whether this is a normal file, a system
  /// header, or an "implicit extern C" system header.
  ///
  /// This state can be modified with flags on GNU linemarker directives like:
  ///   # 4 "foo.h" 3
  /// which changes all source locations in the current file after that to be
  /// considered to be from a system header.
  SrcMgr::CharacteristicKind getFileCharacteristic(SourceLocation Loc) const;

  /// getPresumedLoc - This method returns the "presumed" location of a
  /// SourceLocation specifies.  A "presumed location" can be modified by #line
  /// or GNU line marker directives.  This provides a view on the data that a
  /// user should see in diagnostics, for example.
  ///
  /// Note that a presumed location is always given as the instantiation point
  /// of an instantiation location, not at the spelling location.
  PresumedLoc getPresumedLoc(SourceLocation Loc) const;

  /// isFromSameFile - Returns true if both SourceLocations correspond to
  ///  the same file.
  bool isFromSameFile(SourceLocation Loc1, SourceLocation Loc2) const {
    return getFileID(Loc1) == getFileID(Loc2);
  }

  /// isFromMainFile - Returns true if the file of provided SourceLocation is
  ///   the main file.
  bool isFromMainFile(SourceLocation Loc) const {
    return getFileID(Loc) == getMainFileID();
  }

  /// isInSystemHeader - Returns if a SourceLocation is in a system header.
  bool isInSystemHeader(SourceLocation Loc) const {
    return getFileCharacteristic(Loc) != SrcMgr::C_User;
  }

  /// isInExternCSystemHeader - Returns if a SourceLocation is in an "extern C"
  /// system header.
  bool isInExternCSystemHeader(SourceLocation Loc) const {
    return getFileCharacteristic(Loc) == SrcMgr::C_ExternCSystem;
  }

  //===--------------------------------------------------------------------===//
  // Line Table Manipulation Routines
  //===--------------------------------------------------------------------===//

  /// getLineTableFilenameID - Return the uniqued ID for the specified filename.
  ///
  unsigned getLineTableFilenameID(const char *Ptr, unsigned Len);

  /// AddLineNote - Add a line note to the line table for the FileID and offset
  /// specified by Loc.  If FilenameID is -1, it is considered to be
  /// unspecified.
  void AddLineNote(SourceLocation Loc, unsigned LineNo, int FilenameID);
  void AddLineNote(SourceLocation Loc, unsigned LineNo, int FilenameID,
                   bool IsFileEntry, bool IsFileExit,
                   bool IsSystemHeader, bool IsExternCHeader);

  /// \brief Determine if the source manager has a line table.
  bool hasLineTable() const { return LineTable != 0; }

  /// \brief Retrieve the stored line table.
  LineTableInfo &getLineTable();

  //===--------------------------------------------------------------------===//
  // Other miscellaneous methods.
  //===--------------------------------------------------------------------===//

  /// \brief Get the source location for the given file:line:col triplet.
  ///
  /// If the source file is included multiple times, the source location will
  /// be based upon the first inclusion.
  SourceLocation getLocation(const FileEntry *SourceFile,
                             unsigned Line, unsigned Col) const;

  /// \brief Determines the order of 2 source locations in the translation unit.
  ///
  /// \returns true if LHS source location comes before RHS, false otherwise.
  bool isBeforeInTranslationUnit(SourceLocation LHS, SourceLocation RHS) const;

  // Iterators over FileInfos.
  typedef llvm::DenseMap<const FileEntry*, SrcMgr::ContentCache*>
      ::const_iterator fileinfo_iterator;
  fileinfo_iterator fileinfo_begin() const { return FileInfos.begin(); }
  fileinfo_iterator fileinfo_end() const { return FileInfos.end(); }
  bool hasFileInfo(const FileEntry *File) const {
    return FileInfos.find(File) != FileInfos.end();
  }

  /// PrintStats - Print statistics to stderr.
  ///
  void PrintStats() const;

  unsigned sloc_entry_size() const { return SLocEntryTable.size(); }

  // FIXME: Exposing this is a little gross; what we want is a good way
  //  to iterate the entries that were not defined in a PCH file (or
  //  any other external source).
  unsigned sloc_loaded_entry_size() const { return SLocEntryLoaded.size(); }

  const SrcMgr::SLocEntry &getSLocEntry(unsigned ID) const {
    assert(ID < SLocEntryTable.size() && "Invalid id");
    if (ExternalSLocEntries &&
        ID < SLocEntryLoaded.size() &&
        !SLocEntryLoaded[ID])
      ExternalSLocEntries->ReadSLocEntry(ID);
    return SLocEntryTable[ID];
  }

  const SrcMgr::SLocEntry &getSLocEntry(FileID FID) const {
    return getSLocEntry(FID.ID);
  }

  unsigned getNextOffset() const { return NextOffset; }

  /// \brief Preallocate some number of source location entries, which
  /// will be loaded as needed from the given external source.
  void PreallocateSLocEntries(ExternalSLocEntrySource *Source,
                              unsigned NumSLocEntries,
                              unsigned NextOffset);

  /// \brief Clear out any preallocated source location entries that
  /// haven't already been loaded.
  void ClearPreallocatedSLocEntries();

private:
  /// isOffsetInFileID - Return true if the specified FileID contains the
  /// specified SourceLocation offset.  This is a very hot method.
  inline bool isOffsetInFileID(FileID FID, unsigned SLocOffset) const {
    const SrcMgr::SLocEntry &Entry = getSLocEntry(FID);
    // If the entry is after the offset, it can't contain it.
    if (SLocOffset < Entry.getOffset()) return false;

    // If this is the last entry than it does.  Otherwise, the entry after it
    // has to not include it.
    if (FID.ID+1 == SLocEntryTable.size()) return true;

    return SLocOffset < getSLocEntry(FileID::get(FID.ID+1)).getOffset();
  }

  /// createFileID - Create a new fileID for the specified ContentCache and
  ///  include position.  This works regardless of whether the ContentCache
  ///  corresponds to a file or some other input source.
  FileID createFileID(const SrcMgr::ContentCache* File,
                      SourceLocation IncludePos,
                      SrcMgr::CharacteristicKind DirCharacter,
                      unsigned PreallocatedID = 0,
                      unsigned Offset = 0);

  const SrcMgr::ContentCache *
    getOrCreateContentCache(const FileEntry *SourceFile);

  /// createMemBufferContentCache - Create a new ContentCache for the specified
  ///  memory buffer.
  const SrcMgr::ContentCache*
  createMemBufferContentCache(const llvm::MemoryBuffer *Buf);

  FileID getFileIDSlow(unsigned SLocOffset) const;

  SourceLocation getInstantiationLocSlowCase(SourceLocation Loc) const;
  SourceLocation getSpellingLocSlowCase(SourceLocation Loc) const;

  std::pair<FileID, unsigned>
  getDecomposedInstantiationLocSlowCase(const SrcMgr::SLocEntry *E,
                                        unsigned Offset) const;
  std::pair<FileID, unsigned>
  getDecomposedSpellingLocSlowCase(const SrcMgr::SLocEntry *E,
                                   unsigned Offset) const;
};


}  // end namespace clang

#endif
OpenPOWER on IntegriCloud