1//===--- SourceManager.cpp - Track and cache source files -----------------===//
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 implements the SourceManager interface.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/Basic/SourceManager.h"
15#include "clang/Basic/SourceManagerInternals.h"
16#include "clang/Basic/Diagnostic.h"
17#include "clang/Basic/FileManager.h"
18#include "llvm/ADT/StringSwitch.h"
19#include "llvm/ADT/Optional.h"
20#include "llvm/ADT/STLExtras.h"
21#include "llvm/Support/Compiler.h"
22#include "llvm/Support/MemoryBuffer.h"
23#include "llvm/Support/raw_ostream.h"
24#include "llvm/Support/Path.h"
25#include "llvm/Support/Capacity.h"
26#include <algorithm>
27#include <string>
28#include <cstring>
29#include <sys/stat.h>
30
31using namespace clang;
32using namespace SrcMgr;
33using llvm::MemoryBuffer;
34
35//===----------------------------------------------------------------------===//
36// SourceManager Helper Classes
37//===----------------------------------------------------------------------===//
38
39ContentCache::~ContentCache() {
40  if (shouldFreeBuffer())
41    delete Buffer.getPointer();
42}
43
44/// getSizeBytesMapped - Returns the number of bytes actually mapped for this
45/// ContentCache. This can be 0 if the MemBuffer was not actually expanded.
46unsigned ContentCache::getSizeBytesMapped() const {
47  return Buffer.getPointer() ? Buffer.getPointer()->getBufferSize() : 0;
48}
49
50/// Returns the kind of memory used to back the memory buffer for
51/// this content cache.  This is used for performance analysis.
52llvm::MemoryBuffer::BufferKind ContentCache::getMemoryBufferKind() const {
53  assert(Buffer.getPointer());
54
55  // Should be unreachable, but keep for sanity.
56  if (!Buffer.getPointer())
57    return llvm::MemoryBuffer::MemoryBuffer_Malloc;
58
59  const llvm::MemoryBuffer *buf = Buffer.getPointer();
60  return buf->getBufferKind();
61}
62
63/// getSize - Returns the size of the content encapsulated by this ContentCache.
64///  This can be the size of the source file or the size of an arbitrary
65///  scratch buffer.  If the ContentCache encapsulates a source file, that
66///  file is not lazily brought in from disk to satisfy this query.
67unsigned ContentCache::getSize() const {
68  return Buffer.getPointer() ? (unsigned) Buffer.getPointer()->getBufferSize()
69                             : (unsigned) ContentsEntry->getSize();
70}
71
72void ContentCache::replaceBuffer(const llvm::MemoryBuffer *B,
73                                 bool DoNotFree) {
74  if (B && B == Buffer.getPointer()) {
75    assert(0 && "Replacing with the same buffer");
76    Buffer.setInt(DoNotFree? DoNotFreeFlag : 0);
77    return;
78  }
79
80  if (shouldFreeBuffer())
81    delete Buffer.getPointer();
82  Buffer.setPointer(B);
83  Buffer.setInt(DoNotFree? DoNotFreeFlag : 0);
84}
85
86const llvm::MemoryBuffer *ContentCache::getBuffer(DiagnosticsEngine &Diag,
87                                                  const SourceManager &SM,
88                                                  SourceLocation Loc,
89                                                  bool *Invalid) const {
90  // Lazily create the Buffer for ContentCaches that wrap files.  If we already
91  // computed it, just return what we have.
92  if (Buffer.getPointer() || ContentsEntry == 0) {
93    if (Invalid)
94      *Invalid = isBufferInvalid();
95
96    return Buffer.getPointer();
97  }
98
99  std::string ErrorStr;
100  bool isVolatile = SM.userFilesAreVolatile() && !IsSystemFile;
101  Buffer.setPointer(SM.getFileManager().getBufferForFile(ContentsEntry,
102                                                         &ErrorStr,
103                                                         isVolatile));
104
105  // If we were unable to open the file, then we are in an inconsistent
106  // situation where the content cache referenced a file which no longer
107  // exists. Most likely, we were using a stat cache with an invalid entry but
108  // the file could also have been removed during processing. Since we can't
109  // really deal with this situation, just create an empty buffer.
110  //
111  // FIXME: This is definitely not ideal, but our immediate clients can't
112  // currently handle returning a null entry here. Ideally we should detect
113  // that we are in an inconsistent situation and error out as quickly as
114  // possible.
115  if (!Buffer.getPointer()) {
116    const StringRef FillStr("<<<MISSING SOURCE FILE>>>\n");
117    Buffer.setPointer(MemoryBuffer::getNewMemBuffer(ContentsEntry->getSize(),
118                                                    "<invalid>"));
119    char *Ptr = const_cast<char*>(Buffer.getPointer()->getBufferStart());
120    for (unsigned i = 0, e = ContentsEntry->getSize(); i != e; ++i)
121      Ptr[i] = FillStr[i % FillStr.size()];
122
123    if (Diag.isDiagnosticInFlight())
124      Diag.SetDelayedDiagnostic(diag::err_cannot_open_file,
125                                ContentsEntry->getName(), ErrorStr);
126    else
127      Diag.Report(Loc, diag::err_cannot_open_file)
128        << ContentsEntry->getName() << ErrorStr;
129
130    Buffer.setInt(Buffer.getInt() | InvalidFlag);
131
132    if (Invalid) *Invalid = true;
133    return Buffer.getPointer();
134  }
135
136  // Check that the file's size is the same as in the file entry (which may
137  // have come from a stat cache).
138  if (getRawBuffer()->getBufferSize() != (size_t)ContentsEntry->getSize()) {
139    if (Diag.isDiagnosticInFlight())
140      Diag.SetDelayedDiagnostic(diag::err_file_modified,
141                                ContentsEntry->getName());
142    else
143      Diag.Report(Loc, diag::err_file_modified)
144        << ContentsEntry->getName();
145
146    Buffer.setInt(Buffer.getInt() | InvalidFlag);
147    if (Invalid) *Invalid = true;
148    return Buffer.getPointer();
149  }
150
151  // If the buffer is valid, check to see if it has a UTF Byte Order Mark
152  // (BOM).  We only support UTF-8 with and without a BOM right now.  See
153  // http://en.wikipedia.org/wiki/Byte_order_mark for more information.
154  StringRef BufStr = Buffer.getPointer()->getBuffer();
155  const char *InvalidBOM = llvm::StringSwitch<const char *>(BufStr)
156    .StartsWith("\xFE\xFF", "UTF-16 (BE)")
157    .StartsWith("\xFF\xFE", "UTF-16 (LE)")
158    .StartsWith("\x00\x00\xFE\xFF", "UTF-32 (BE)")
159    .StartsWith("\xFF\xFE\x00\x00", "UTF-32 (LE)")
160    .StartsWith("\x2B\x2F\x76", "UTF-7")
161    .StartsWith("\xF7\x64\x4C", "UTF-1")
162    .StartsWith("\xDD\x73\x66\x73", "UTF-EBCDIC")
163    .StartsWith("\x0E\xFE\xFF", "SDSU")
164    .StartsWith("\xFB\xEE\x28", "BOCU-1")
165    .StartsWith("\x84\x31\x95\x33", "GB-18030")
166    .Default(0);
167
168  if (InvalidBOM) {
169    Diag.Report(Loc, diag::err_unsupported_bom)
170      << InvalidBOM << ContentsEntry->getName();
171    Buffer.setInt(Buffer.getInt() | InvalidFlag);
172  }
173
174  if (Invalid)
175    *Invalid = isBufferInvalid();
176
177  return Buffer.getPointer();
178}
179
180unsigned LineTableInfo::getLineTableFilenameID(StringRef Name) {
181  // Look up the filename in the string table, returning the pre-existing value
182  // if it exists.
183  llvm::StringMapEntry<unsigned> &Entry =
184    FilenameIDs.GetOrCreateValue(Name, ~0U);
185  if (Entry.getValue() != ~0U)
186    return Entry.getValue();
187
188  // Otherwise, assign this the next available ID.
189  Entry.setValue(FilenamesByID.size());
190  FilenamesByID.push_back(&Entry);
191  return FilenamesByID.size()-1;
192}
193
194/// AddLineNote - Add a line note to the line table that indicates that there
195/// is a \#line at the specified FID/Offset location which changes the presumed
196/// location to LineNo/FilenameID.
197void LineTableInfo::AddLineNote(FileID FID, unsigned Offset,
198                                unsigned LineNo, int FilenameID) {
199  std::vector<LineEntry> &Entries = LineEntries[FID];
200
201  assert((Entries.empty() || Entries.back().FileOffset < Offset) &&
202         "Adding line entries out of order!");
203
204  SrcMgr::CharacteristicKind Kind = SrcMgr::C_User;
205  unsigned IncludeOffset = 0;
206
207  if (!Entries.empty()) {
208    // If this is a '#line 4' after '#line 42 "foo.h"', make sure to remember
209    // that we are still in "foo.h".
210    if (FilenameID == -1)
211      FilenameID = Entries.back().FilenameID;
212
213    // If we are after a line marker that switched us to system header mode, or
214    // that set #include information, preserve it.
215    Kind = Entries.back().FileKind;
216    IncludeOffset = Entries.back().IncludeOffset;
217  }
218
219  Entries.push_back(LineEntry::get(Offset, LineNo, FilenameID, Kind,
220                                   IncludeOffset));
221}
222
223/// AddLineNote This is the same as the previous version of AddLineNote, but is
224/// used for GNU line markers.  If EntryExit is 0, then this doesn't change the
225/// presumed \#include stack.  If it is 1, this is a file entry, if it is 2 then
226/// this is a file exit.  FileKind specifies whether this is a system header or
227/// extern C system header.
228void LineTableInfo::AddLineNote(FileID FID, unsigned Offset,
229                                unsigned LineNo, int FilenameID,
230                                unsigned EntryExit,
231                                SrcMgr::CharacteristicKind FileKind) {
232  assert(FilenameID != -1 && "Unspecified filename should use other accessor");
233
234  std::vector<LineEntry> &Entries = LineEntries[FID];
235
236  assert((Entries.empty() || Entries.back().FileOffset < Offset) &&
237         "Adding line entries out of order!");
238
239  unsigned IncludeOffset = 0;
240  if (EntryExit == 0) {  // No #include stack change.
241    IncludeOffset = Entries.empty() ? 0 : Entries.back().IncludeOffset;
242  } else if (EntryExit == 1) {
243    IncludeOffset = Offset-1;
244  } else if (EntryExit == 2) {
245    assert(!Entries.empty() && Entries.back().IncludeOffset &&
246       "PPDirectives should have caught case when popping empty include stack");
247
248    // Get the include loc of the last entries' include loc as our include loc.
249    IncludeOffset = 0;
250    if (const LineEntry *PrevEntry =
251          FindNearestLineEntry(FID, Entries.back().IncludeOffset))
252      IncludeOffset = PrevEntry->IncludeOffset;
253  }
254
255  Entries.push_back(LineEntry::get(Offset, LineNo, FilenameID, FileKind,
256                                   IncludeOffset));
257}
258
259
260/// FindNearestLineEntry - Find the line entry nearest to FID that is before
261/// it.  If there is no line entry before Offset in FID, return null.
262const LineEntry *LineTableInfo::FindNearestLineEntry(FileID FID,
263                                                     unsigned Offset) {
264  const std::vector<LineEntry> &Entries = LineEntries[FID];
265  assert(!Entries.empty() && "No #line entries for this FID after all!");
266
267  // It is very common for the query to be after the last #line, check this
268  // first.
269  if (Entries.back().FileOffset <= Offset)
270    return &Entries.back();
271
272  // Do a binary search to find the maximal element that is still before Offset.
273  std::vector<LineEntry>::const_iterator I =
274    std::upper_bound(Entries.begin(), Entries.end(), Offset);
275  if (I == Entries.begin()) return 0;
276  return &*--I;
277}
278
279/// \brief Add a new line entry that has already been encoded into
280/// the internal representation of the line table.
281void LineTableInfo::AddEntry(FileID FID,
282                             const std::vector<LineEntry> &Entries) {
283  LineEntries[FID] = Entries;
284}
285
286/// getLineTableFilenameID - Return the uniqued ID for the specified filename.
287///
288unsigned SourceManager::getLineTableFilenameID(StringRef Name) {
289  if (LineTable == 0)
290    LineTable = new LineTableInfo();
291  return LineTable->getLineTableFilenameID(Name);
292}
293
294
295/// AddLineNote - Add a line note to the line table for the FileID and offset
296/// specified by Loc.  If FilenameID is -1, it is considered to be
297/// unspecified.
298void SourceManager::AddLineNote(SourceLocation Loc, unsigned LineNo,
299                                int FilenameID) {
300  std::pair<FileID, unsigned> LocInfo = getDecomposedExpansionLoc(Loc);
301
302  bool Invalid = false;
303  const SLocEntry &Entry = getSLocEntry(LocInfo.first, &Invalid);
304  if (!Entry.isFile() || Invalid)
305    return;
306
307  const SrcMgr::FileInfo &FileInfo = Entry.getFile();
308
309  // Remember that this file has #line directives now if it doesn't already.
310  const_cast<SrcMgr::FileInfo&>(FileInfo).setHasLineDirectives();
311
312  if (LineTable == 0)
313    LineTable = new LineTableInfo();
314  LineTable->AddLineNote(LocInfo.first, LocInfo.second, LineNo, FilenameID);
315}
316
317/// AddLineNote - Add a GNU line marker to the line table.
318void SourceManager::AddLineNote(SourceLocation Loc, unsigned LineNo,
319                                int FilenameID, bool IsFileEntry,
320                                bool IsFileExit, bool IsSystemHeader,
321                                bool IsExternCHeader) {
322  // If there is no filename and no flags, this is treated just like a #line,
323  // which does not change the flags of the previous line marker.
324  if (FilenameID == -1) {
325    assert(!IsFileEntry && !IsFileExit && !IsSystemHeader && !IsExternCHeader &&
326           "Can't set flags without setting the filename!");
327    return AddLineNote(Loc, LineNo, FilenameID);
328  }
329
330  std::pair<FileID, unsigned> LocInfo = getDecomposedExpansionLoc(Loc);
331
332  bool Invalid = false;
333  const SLocEntry &Entry = getSLocEntry(LocInfo.first, &Invalid);
334  if (!Entry.isFile() || Invalid)
335    return;
336
337  const SrcMgr::FileInfo &FileInfo = Entry.getFile();
338
339  // Remember that this file has #line directives now if it doesn't already.
340  const_cast<SrcMgr::FileInfo&>(FileInfo).setHasLineDirectives();
341
342  if (LineTable == 0)
343    LineTable = new LineTableInfo();
344
345  SrcMgr::CharacteristicKind FileKind;
346  if (IsExternCHeader)
347    FileKind = SrcMgr::C_ExternCSystem;
348  else if (IsSystemHeader)
349    FileKind = SrcMgr::C_System;
350  else
351    FileKind = SrcMgr::C_User;
352
353  unsigned EntryExit = 0;
354  if (IsFileEntry)
355    EntryExit = 1;
356  else if (IsFileExit)
357    EntryExit = 2;
358
359  LineTable->AddLineNote(LocInfo.first, LocInfo.second, LineNo, FilenameID,
360                         EntryExit, FileKind);
361}
362
363LineTableInfo &SourceManager::getLineTable() {
364  if (LineTable == 0)
365    LineTable = new LineTableInfo();
366  return *LineTable;
367}
368
369//===----------------------------------------------------------------------===//
370// Private 'Create' methods.
371//===----------------------------------------------------------------------===//
372
373SourceManager::SourceManager(DiagnosticsEngine &Diag, FileManager &FileMgr,
374                             bool UserFilesAreVolatile)
375  : Diag(Diag), FileMgr(FileMgr), OverridenFilesKeepOriginalName(true),
376    UserFilesAreVolatile(UserFilesAreVolatile),
377    ExternalSLocEntries(0), LineTable(0), NumLinearScans(0),
378    NumBinaryProbes(0), FakeBufferForRecovery(0),
379    FakeContentCacheForRecovery(0) {
380  clearIDTables();
381  Diag.setSourceManager(this);
382}
383
384SourceManager::~SourceManager() {
385  delete LineTable;
386
387  // Delete FileEntry objects corresponding to content caches.  Since the actual
388  // content cache objects are bump pointer allocated, we just have to run the
389  // dtors, but we call the deallocate method for completeness.
390  for (unsigned i = 0, e = MemBufferInfos.size(); i != e; ++i) {
391    if (MemBufferInfos[i]) {
392      MemBufferInfos[i]->~ContentCache();
393      ContentCacheAlloc.Deallocate(MemBufferInfos[i]);
394    }
395  }
396  for (llvm::DenseMap<const FileEntry*, SrcMgr::ContentCache*>::iterator
397       I = FileInfos.begin(), E = FileInfos.end(); I != E; ++I) {
398    if (I->second) {
399      I->second->~ContentCache();
400      ContentCacheAlloc.Deallocate(I->second);
401    }
402  }
403
404  delete FakeBufferForRecovery;
405  delete FakeContentCacheForRecovery;
406
407  for (llvm::DenseMap<FileID, MacroArgsMap *>::iterator
408         I = MacroArgsCacheMap.begin(),E = MacroArgsCacheMap.end(); I!=E; ++I) {
409    delete I->second;
410  }
411}
412
413void SourceManager::clearIDTables() {
414  MainFileID = FileID();
415  LocalSLocEntryTable.clear();
416  LoadedSLocEntryTable.clear();
417  SLocEntryLoaded.clear();
418  LastLineNoFileIDQuery = FileID();
419  LastLineNoContentCache = 0;
420  LastFileIDLookup = FileID();
421
422  if (LineTable)
423    LineTable->clear();
424
425  // Use up FileID #0 as an invalid expansion.
426  NextLocalOffset = 0;
427  CurrentLoadedOffset = MaxLoadedOffset;
428  createExpansionLoc(SourceLocation(),SourceLocation(),SourceLocation(), 1);
429}
430
431/// getOrCreateContentCache - Create or return a cached ContentCache for the
432/// specified file.
433const ContentCache *
434SourceManager::getOrCreateContentCache(const FileEntry *FileEnt,
435                                       bool isSystemFile) {
436  assert(FileEnt && "Didn't specify a file entry to use?");
437
438  // Do we already have information about this file?
439  ContentCache *&Entry = FileInfos[FileEnt];
440  if (Entry) return Entry;
441
442  // Nope, create a new Cache entry.  Make sure it is at least 8-byte aligned
443  // so that FileInfo can use the low 3 bits of the pointer for its own
444  // nefarious purposes.
445  unsigned EntryAlign = llvm::AlignOf<ContentCache>::Alignment;
446  EntryAlign = std::max(8U, EntryAlign);
447  Entry = ContentCacheAlloc.Allocate<ContentCache>(1, EntryAlign);
448
449  if (OverriddenFilesInfo) {
450    // If the file contents are overridden with contents from another file,
451    // pass that file to ContentCache.
452    llvm::DenseMap<const FileEntry *, const FileEntry *>::iterator
453        overI = OverriddenFilesInfo->OverriddenFiles.find(FileEnt);
454    if (overI == OverriddenFilesInfo->OverriddenFiles.end())
455      new (Entry) ContentCache(FileEnt);
456    else
457      new (Entry) ContentCache(OverridenFilesKeepOriginalName ? FileEnt
458                                                              : overI->second,
459                               overI->second);
460  } else {
461    new (Entry) ContentCache(FileEnt);
462  }
463
464  Entry->IsSystemFile = isSystemFile;
465
466  return Entry;
467}
468
469
470/// createMemBufferContentCache - Create a new ContentCache for the specified
471///  memory buffer.  This does no caching.
472const ContentCache*
473SourceManager::createMemBufferContentCache(const MemoryBuffer *Buffer) {
474  // Add a new ContentCache to the MemBufferInfos list and return it.  Make sure
475  // it is at least 8-byte aligned so that FileInfo can use the low 3 bits of
476  // the pointer for its own nefarious purposes.
477  unsigned EntryAlign = llvm::AlignOf<ContentCache>::Alignment;
478  EntryAlign = std::max(8U, EntryAlign);
479  ContentCache *Entry = ContentCacheAlloc.Allocate<ContentCache>(1, EntryAlign);
480  new (Entry) ContentCache();
481  MemBufferInfos.push_back(Entry);
482  Entry->setBuffer(Buffer);
483  return Entry;
484}
485
486const SrcMgr::SLocEntry &SourceManager::loadSLocEntry(unsigned Index,
487                                                      bool *Invalid) const {
488  assert(!SLocEntryLoaded[Index]);
489  if (ExternalSLocEntries->ReadSLocEntry(-(static_cast<int>(Index) + 2))) {
490    if (Invalid)
491      *Invalid = true;
492    // If the file of the SLocEntry changed we could still have loaded it.
493    if (!SLocEntryLoaded[Index]) {
494      // Try to recover; create a SLocEntry so the rest of clang can handle it.
495      LoadedSLocEntryTable[Index] = SLocEntry::get(0,
496                                 FileInfo::get(SourceLocation(),
497                                               getFakeContentCacheForRecovery(),
498                                               SrcMgr::C_User));
499    }
500  }
501
502  return LoadedSLocEntryTable[Index];
503}
504
505std::pair<int, unsigned>
506SourceManager::AllocateLoadedSLocEntries(unsigned NumSLocEntries,
507                                         unsigned TotalSize) {
508  assert(ExternalSLocEntries && "Don't have an external sloc source");
509  LoadedSLocEntryTable.resize(LoadedSLocEntryTable.size() + NumSLocEntries);
510  SLocEntryLoaded.resize(LoadedSLocEntryTable.size());
511  CurrentLoadedOffset -= TotalSize;
512  assert(CurrentLoadedOffset >= NextLocalOffset && "Out of source locations");
513  int ID = LoadedSLocEntryTable.size();
514  return std::make_pair(-ID - 1, CurrentLoadedOffset);
515}
516
517/// \brief As part of recovering from missing or changed content, produce a
518/// fake, non-empty buffer.
519const llvm::MemoryBuffer *SourceManager::getFakeBufferForRecovery() const {
520  if (!FakeBufferForRecovery)
521    FakeBufferForRecovery
522      = llvm::MemoryBuffer::getMemBuffer("<<<INVALID BUFFER>>");
523
524  return FakeBufferForRecovery;
525}
526
527/// \brief As part of recovering from missing or changed content, produce a
528/// fake content cache.
529const SrcMgr::ContentCache *
530SourceManager::getFakeContentCacheForRecovery() const {
531  if (!FakeContentCacheForRecovery) {
532    FakeContentCacheForRecovery = new ContentCache();
533    FakeContentCacheForRecovery->replaceBuffer(getFakeBufferForRecovery(),
534                                               /*DoNotFree=*/true);
535  }
536  return FakeContentCacheForRecovery;
537}
538
539//===----------------------------------------------------------------------===//
540// Methods to create new FileID's and macro expansions.
541//===----------------------------------------------------------------------===//
542
543/// createFileID - Create a new FileID for the specified ContentCache and
544/// include position.  This works regardless of whether the ContentCache
545/// corresponds to a file or some other input source.
546FileID SourceManager::createFileID(const ContentCache *File,
547                                   SourceLocation IncludePos,
548                                   SrcMgr::CharacteristicKind FileCharacter,
549                                   int LoadedID, unsigned LoadedOffset) {
550  if (LoadedID < 0) {
551    assert(LoadedID != -1 && "Loading sentinel FileID");
552    unsigned Index = unsigned(-LoadedID) - 2;
553    assert(Index < LoadedSLocEntryTable.size() && "FileID out of range");
554    assert(!SLocEntryLoaded[Index] && "FileID already loaded");
555    LoadedSLocEntryTable[Index] = SLocEntry::get(LoadedOffset,
556        FileInfo::get(IncludePos, File, FileCharacter));
557    SLocEntryLoaded[Index] = true;
558    return FileID::get(LoadedID);
559  }
560  LocalSLocEntryTable.push_back(SLocEntry::get(NextLocalOffset,
561                                               FileInfo::get(IncludePos, File,
562                                                             FileCharacter)));
563  unsigned FileSize = File->getSize();
564  assert(NextLocalOffset + FileSize + 1 > NextLocalOffset &&
565         NextLocalOffset + FileSize + 1 <= CurrentLoadedOffset &&
566         "Ran out of source locations!");
567  // We do a +1 here because we want a SourceLocation that means "the end of the
568  // file", e.g. for the "no newline at the end of the file" diagnostic.
569  NextLocalOffset += FileSize + 1;
570
571  // Set LastFileIDLookup to the newly created file.  The next getFileID call is
572  // almost guaranteed to be from that file.
573  FileID FID = FileID::get(LocalSLocEntryTable.size()-1);
574  return LastFileIDLookup = FID;
575}
576
577SourceLocation
578SourceManager::createMacroArgExpansionLoc(SourceLocation SpellingLoc,
579                                          SourceLocation ExpansionLoc,
580                                          unsigned TokLength) {
581  ExpansionInfo Info = ExpansionInfo::createForMacroArg(SpellingLoc,
582                                                        ExpansionLoc);
583  return createExpansionLocImpl(Info, TokLength);
584}
585
586SourceLocation
587SourceManager::createExpansionLoc(SourceLocation SpellingLoc,
588                                  SourceLocation ExpansionLocStart,
589                                  SourceLocation ExpansionLocEnd,
590                                  unsigned TokLength,
591                                  int LoadedID,
592                                  unsigned LoadedOffset) {
593  ExpansionInfo Info = ExpansionInfo::create(SpellingLoc, ExpansionLocStart,
594                                             ExpansionLocEnd);
595  return createExpansionLocImpl(Info, TokLength, LoadedID, LoadedOffset);
596}
597
598SourceLocation
599SourceManager::createExpansionLocImpl(const ExpansionInfo &Info,
600                                      unsigned TokLength,
601                                      int LoadedID,
602                                      unsigned LoadedOffset) {
603  if (LoadedID < 0) {
604    assert(LoadedID != -1 && "Loading sentinel FileID");
605    unsigned Index = unsigned(-LoadedID) - 2;
606    assert(Index < LoadedSLocEntryTable.size() && "FileID out of range");
607    assert(!SLocEntryLoaded[Index] && "FileID already loaded");
608    LoadedSLocEntryTable[Index] = SLocEntry::get(LoadedOffset, Info);
609    SLocEntryLoaded[Index] = true;
610    return SourceLocation::getMacroLoc(LoadedOffset);
611  }
612  LocalSLocEntryTable.push_back(SLocEntry::get(NextLocalOffset, Info));
613  assert(NextLocalOffset + TokLength + 1 > NextLocalOffset &&
614         NextLocalOffset + TokLength + 1 <= CurrentLoadedOffset &&
615         "Ran out of source locations!");
616  // See createFileID for that +1.
617  NextLocalOffset += TokLength + 1;
618  return SourceLocation::getMacroLoc(NextLocalOffset - (TokLength + 1));
619}
620
621const llvm::MemoryBuffer *
622SourceManager::getMemoryBufferForFile(const FileEntry *File,
623                                      bool *Invalid) {
624  const SrcMgr::ContentCache *IR = getOrCreateContentCache(File);
625  assert(IR && "getOrCreateContentCache() cannot return NULL");
626  return IR->getBuffer(Diag, *this, SourceLocation(), Invalid);
627}
628
629void SourceManager::overrideFileContents(const FileEntry *SourceFile,
630                                         const llvm::MemoryBuffer *Buffer,
631                                         bool DoNotFree) {
632  const SrcMgr::ContentCache *IR = getOrCreateContentCache(SourceFile);
633  assert(IR && "getOrCreateContentCache() cannot return NULL");
634
635  const_cast<SrcMgr::ContentCache *>(IR)->replaceBuffer(Buffer, DoNotFree);
636  const_cast<SrcMgr::ContentCache *>(IR)->BufferOverridden = true;
637
638  getOverriddenFilesInfo().OverriddenFilesWithBuffer.insert(SourceFile);
639}
640
641void SourceManager::overrideFileContents(const FileEntry *SourceFile,
642                                         const FileEntry *NewFile) {
643  assert(SourceFile->getSize() == NewFile->getSize() &&
644         "Different sizes, use the FileManager to create a virtual file with "
645         "the correct size");
646  assert(FileInfos.count(SourceFile) == 0 &&
647         "This function should be called at the initialization stage, before "
648         "any parsing occurs.");
649  getOverriddenFilesInfo().OverriddenFiles[SourceFile] = NewFile;
650}
651
652void SourceManager::disableFileContentsOverride(const FileEntry *File) {
653  if (!isFileOverridden(File))
654    return;
655
656  const SrcMgr::ContentCache *IR = getOrCreateContentCache(File);
657  const_cast<SrcMgr::ContentCache *>(IR)->replaceBuffer(0);
658  const_cast<SrcMgr::ContentCache *>(IR)->ContentsEntry = IR->OrigEntry;
659
660  assert(OverriddenFilesInfo);
661  OverriddenFilesInfo->OverriddenFiles.erase(File);
662  OverriddenFilesInfo->OverriddenFilesWithBuffer.erase(File);
663}
664
665StringRef SourceManager::getBufferData(FileID FID, bool *Invalid) const {
666  bool MyInvalid = false;
667  const SLocEntry &SLoc = getSLocEntry(FID, &MyInvalid);
668  if (!SLoc.isFile() || MyInvalid) {
669    if (Invalid)
670      *Invalid = true;
671    return "<<<<<INVALID SOURCE LOCATION>>>>>";
672  }
673
674  const llvm::MemoryBuffer *Buf
675    = SLoc.getFile().getContentCache()->getBuffer(Diag, *this, SourceLocation(),
676                                                  &MyInvalid);
677  if (Invalid)
678    *Invalid = MyInvalid;
679
680  if (MyInvalid)
681    return "<<<<<INVALID SOURCE LOCATION>>>>>";
682
683  return Buf->getBuffer();
684}
685
686//===----------------------------------------------------------------------===//
687// SourceLocation manipulation methods.
688//===----------------------------------------------------------------------===//
689
690/// \brief Return the FileID for a SourceLocation.
691///
692/// This is the cache-miss path of getFileID. Not as hot as that function, but
693/// still very important. It is responsible for finding the entry in the
694/// SLocEntry tables that contains the specified location.
695FileID SourceManager::getFileIDSlow(unsigned SLocOffset) const {
696  if (!SLocOffset)
697    return FileID::get(0);
698
699  // Now it is time to search for the correct file. See where the SLocOffset
700  // sits in the global view and consult local or loaded buffers for it.
701  if (SLocOffset < NextLocalOffset)
702    return getFileIDLocal(SLocOffset);
703  return getFileIDLoaded(SLocOffset);
704}
705
706/// \brief Return the FileID for a SourceLocation with a low offset.
707///
708/// This function knows that the SourceLocation is in a local buffer, not a
709/// loaded one.
710FileID SourceManager::getFileIDLocal(unsigned SLocOffset) const {
711  assert(SLocOffset < NextLocalOffset && "Bad function choice");
712
713  // After the first and second level caches, I see two common sorts of
714  // behavior: 1) a lot of searched FileID's are "near" the cached file
715  // location or are "near" the cached expansion location. 2) others are just
716  // completely random and may be a very long way away.
717  //
718  // To handle this, we do a linear search for up to 8 steps to catch #1 quickly
719  // then we fall back to a less cache efficient, but more scalable, binary
720  // search to find the location.
721
722  // See if this is near the file point - worst case we start scanning from the
723  // most newly created FileID.
724  std::vector<SrcMgr::SLocEntry>::const_iterator I;
725
726  if (LastFileIDLookup.ID < 0 ||
727      LocalSLocEntryTable[LastFileIDLookup.ID].getOffset() < SLocOffset) {
728    // Neither loc prunes our search.
729    I = LocalSLocEntryTable.end();
730  } else {
731    // Perhaps it is near the file point.
732    I = LocalSLocEntryTable.begin()+LastFileIDLookup.ID;
733  }
734
735  // Find the FileID that contains this.  "I" is an iterator that points to a
736  // FileID whose offset is known to be larger than SLocOffset.
737  unsigned NumProbes = 0;
738  while (1) {
739    --I;
740    if (I->getOffset() <= SLocOffset) {
741      FileID Res = FileID::get(int(I - LocalSLocEntryTable.begin()));
742
743      // If this isn't an expansion, remember it.  We have good locality across
744      // FileID lookups.
745      if (!I->isExpansion())
746        LastFileIDLookup = Res;
747      NumLinearScans += NumProbes+1;
748      return Res;
749    }
750    if (++NumProbes == 8)
751      break;
752  }
753
754  // Convert "I" back into an index.  We know that it is an entry whose index is
755  // larger than the offset we are looking for.
756  unsigned GreaterIndex = I - LocalSLocEntryTable.begin();
757  // LessIndex - This is the lower bound of the range that we're searching.
758  // We know that the offset corresponding to the FileID is is less than
759  // SLocOffset.
760  unsigned LessIndex = 0;
761  NumProbes = 0;
762  while (1) {
763    bool Invalid = false;
764    unsigned MiddleIndex = (GreaterIndex-LessIndex)/2+LessIndex;
765    unsigned MidOffset = getLocalSLocEntry(MiddleIndex, &Invalid).getOffset();
766    if (Invalid)
767      return FileID::get(0);
768
769    ++NumProbes;
770
771    // If the offset of the midpoint is too large, chop the high side of the
772    // range to the midpoint.
773    if (MidOffset > SLocOffset) {
774      GreaterIndex = MiddleIndex;
775      continue;
776    }
777
778    // If the middle index contains the value, succeed and return.
779    // FIXME: This could be made faster by using a function that's aware of
780    // being in the local area.
781    if (isOffsetInFileID(FileID::get(MiddleIndex), SLocOffset)) {
782      FileID Res = FileID::get(MiddleIndex);
783
784      // If this isn't a macro expansion, remember it.  We have good locality
785      // across FileID lookups.
786      if (!LocalSLocEntryTable[MiddleIndex].isExpansion())
787        LastFileIDLookup = Res;
788      NumBinaryProbes += NumProbes;
789      return Res;
790    }
791
792    // Otherwise, move the low-side up to the middle index.
793    LessIndex = MiddleIndex;
794  }
795}
796
797/// \brief Return the FileID for a SourceLocation with a high offset.
798///
799/// This function knows that the SourceLocation is in a loaded buffer, not a
800/// local one.
801FileID SourceManager::getFileIDLoaded(unsigned SLocOffset) const {
802  // Sanity checking, otherwise a bug may lead to hanging in release build.
803  if (SLocOffset < CurrentLoadedOffset) {
804    assert(0 && "Invalid SLocOffset or bad function choice");
805    return FileID();
806  }
807
808  // Essentially the same as the local case, but the loaded array is sorted
809  // in the other direction.
810
811  // First do a linear scan from the last lookup position, if possible.
812  unsigned I;
813  int LastID = LastFileIDLookup.ID;
814  if (LastID >= 0 || getLoadedSLocEntryByID(LastID).getOffset() < SLocOffset)
815    I = 0;
816  else
817    I = (-LastID - 2) + 1;
818
819  unsigned NumProbes;
820  for (NumProbes = 0; NumProbes < 8; ++NumProbes, ++I) {
821    // Make sure the entry is loaded!
822    const SrcMgr::SLocEntry &E = getLoadedSLocEntry(I);
823    if (E.getOffset() <= SLocOffset) {
824      FileID Res = FileID::get(-int(I) - 2);
825
826      if (!E.isExpansion())
827        LastFileIDLookup = Res;
828      NumLinearScans += NumProbes + 1;
829      return Res;
830    }
831  }
832
833  // Linear scan failed. Do the binary search. Note the reverse sorting of the
834  // table: GreaterIndex is the one where the offset is greater, which is
835  // actually a lower index!
836  unsigned GreaterIndex = I;
837  unsigned LessIndex = LoadedSLocEntryTable.size();
838  NumProbes = 0;
839  while (1) {
840    ++NumProbes;
841    unsigned MiddleIndex = (LessIndex - GreaterIndex) / 2 + GreaterIndex;
842    const SrcMgr::SLocEntry &E = getLoadedSLocEntry(MiddleIndex);
843
844    ++NumProbes;
845
846    if (E.getOffset() > SLocOffset) {
847      GreaterIndex = MiddleIndex;
848      continue;
849    }
850
851    if (isOffsetInFileID(FileID::get(-int(MiddleIndex) - 2), SLocOffset)) {
852      FileID Res = FileID::get(-int(MiddleIndex) - 2);
853      if (!E.isExpansion())
854        LastFileIDLookup = Res;
855      NumBinaryProbes += NumProbes;
856      return Res;
857    }
858
859    LessIndex = MiddleIndex;
860  }
861}
862
863SourceLocation SourceManager::
864getExpansionLocSlowCase(SourceLocation Loc) const {
865  do {
866    // Note: If Loc indicates an offset into a token that came from a macro
867    // expansion (e.g. the 5th character of the token) we do not want to add
868    // this offset when going to the expansion location.  The expansion
869    // location is the macro invocation, which the offset has nothing to do
870    // with.  This is unlike when we get the spelling loc, because the offset
871    // directly correspond to the token whose spelling we're inspecting.
872    Loc = getSLocEntry(getFileID(Loc)).getExpansion().getExpansionLocStart();
873  } while (!Loc.isFileID());
874
875  return Loc;
876}
877
878SourceLocation SourceManager::getSpellingLocSlowCase(SourceLocation Loc) const {
879  do {
880    std::pair<FileID, unsigned> LocInfo = getDecomposedLoc(Loc);
881    Loc = getSLocEntry(LocInfo.first).getExpansion().getSpellingLoc();
882    Loc = Loc.getLocWithOffset(LocInfo.second);
883  } while (!Loc.isFileID());
884  return Loc;
885}
886
887SourceLocation SourceManager::getFileLocSlowCase(SourceLocation Loc) const {
888  do {
889    if (isMacroArgExpansion(Loc))
890      Loc = getImmediateSpellingLoc(Loc);
891    else
892      Loc = getImmediateExpansionRange(Loc).first;
893  } while (!Loc.isFileID());
894  return Loc;
895}
896
897
898std::pair<FileID, unsigned>
899SourceManager::getDecomposedExpansionLocSlowCase(
900                                             const SrcMgr::SLocEntry *E) const {
901  // If this is an expansion record, walk through all the expansion points.
902  FileID FID;
903  SourceLocation Loc;
904  unsigned Offset;
905  do {
906    Loc = E->getExpansion().getExpansionLocStart();
907
908    FID = getFileID(Loc);
909    E = &getSLocEntry(FID);
910    Offset = Loc.getOffset()-E->getOffset();
911  } while (!Loc.isFileID());
912
913  return std::make_pair(FID, Offset);
914}
915
916std::pair<FileID, unsigned>
917SourceManager::getDecomposedSpellingLocSlowCase(const SrcMgr::SLocEntry *E,
918                                                unsigned Offset) const {
919  // If this is an expansion record, walk through all the expansion points.
920  FileID FID;
921  SourceLocation Loc;
922  do {
923    Loc = E->getExpansion().getSpellingLoc();
924    Loc = Loc.getLocWithOffset(Offset);
925
926    FID = getFileID(Loc);
927    E = &getSLocEntry(FID);
928    Offset = Loc.getOffset()-E->getOffset();
929  } while (!Loc.isFileID());
930
931  return std::make_pair(FID, Offset);
932}
933
934/// getImmediateSpellingLoc - Given a SourceLocation object, return the
935/// spelling location referenced by the ID.  This is the first level down
936/// towards the place where the characters that make up the lexed token can be
937/// found.  This should not generally be used by clients.
938SourceLocation SourceManager::getImmediateSpellingLoc(SourceLocation Loc) const{
939  if (Loc.isFileID()) return Loc;
940  std::pair<FileID, unsigned> LocInfo = getDecomposedLoc(Loc);
941  Loc = getSLocEntry(LocInfo.first).getExpansion().getSpellingLoc();
942  return Loc.getLocWithOffset(LocInfo.second);
943}
944
945
946/// getImmediateExpansionRange - Loc is required to be an expansion location.
947/// Return the start/end of the expansion information.
948std::pair<SourceLocation,SourceLocation>
949SourceManager::getImmediateExpansionRange(SourceLocation Loc) const {
950  assert(Loc.isMacroID() && "Not a macro expansion loc!");
951  const ExpansionInfo &Expansion = getSLocEntry(getFileID(Loc)).getExpansion();
952  return Expansion.getExpansionLocRange();
953}
954
955/// getExpansionRange - Given a SourceLocation object, return the range of
956/// tokens covered by the expansion in the ultimate file.
957std::pair<SourceLocation,SourceLocation>
958SourceManager::getExpansionRange(SourceLocation Loc) const {
959  if (Loc.isFileID()) return std::make_pair(Loc, Loc);
960
961  std::pair<SourceLocation,SourceLocation> Res =
962    getImmediateExpansionRange(Loc);
963
964  // Fully resolve the start and end locations to their ultimate expansion
965  // points.
966  while (!Res.first.isFileID())
967    Res.first = getImmediateExpansionRange(Res.first).first;
968  while (!Res.second.isFileID())
969    Res.second = getImmediateExpansionRange(Res.second).second;
970  return Res;
971}
972
973bool SourceManager::isMacroArgExpansion(SourceLocation Loc) const {
974  if (!Loc.isMacroID()) return false;
975
976  FileID FID = getFileID(Loc);
977  const SrcMgr::SLocEntry *E = &getSLocEntry(FID);
978  const SrcMgr::ExpansionInfo &Expansion = E->getExpansion();
979  return Expansion.isMacroArgExpansion();
980}
981
982
983//===----------------------------------------------------------------------===//
984// Queries about the code at a SourceLocation.
985//===----------------------------------------------------------------------===//
986
987/// getCharacterData - Return a pointer to the start of the specified location
988/// in the appropriate MemoryBuffer.
989const char *SourceManager::getCharacterData(SourceLocation SL,
990                                            bool *Invalid) const {
991  // Note that this is a hot function in the getSpelling() path, which is
992  // heavily used by -E mode.
993  std::pair<FileID, unsigned> LocInfo = getDecomposedSpellingLoc(SL);
994
995  // Note that calling 'getBuffer()' may lazily page in a source file.
996  bool CharDataInvalid = false;
997  const SLocEntry &Entry = getSLocEntry(LocInfo.first, &CharDataInvalid);
998  if (CharDataInvalid || !Entry.isFile()) {
999    if (Invalid)
1000      *Invalid = true;
1001
1002    return "<<<<INVALID BUFFER>>>>";
1003  }
1004  const llvm::MemoryBuffer *Buffer
1005    = Entry.getFile().getContentCache()
1006                  ->getBuffer(Diag, *this, SourceLocation(), &CharDataInvalid);
1007  if (Invalid)
1008    *Invalid = CharDataInvalid;
1009  return Buffer->getBufferStart() + (CharDataInvalid? 0 : LocInfo.second);
1010}
1011
1012
1013/// getColumnNumber - Return the column # for the specified file position.
1014/// this is significantly cheaper to compute than the line number.
1015unsigned SourceManager::getColumnNumber(FileID FID, unsigned FilePos,
1016                                        bool *Invalid) const {
1017  bool MyInvalid = false;
1018  const llvm::MemoryBuffer *MemBuf = getBuffer(FID, &MyInvalid);
1019  if (Invalid)
1020    *Invalid = MyInvalid;
1021
1022  if (MyInvalid)
1023    return 1;
1024
1025  // It is okay to request a position just past the end of the buffer.
1026  if (FilePos > MemBuf->getBufferSize()) {
1027    if (Invalid)
1028      *Invalid = true;
1029    return 1;
1030  }
1031
1032  const char *Buf = MemBuf->getBufferStart();
1033  unsigned LineStart = FilePos;
1034  while (LineStart && Buf[LineStart-1] != '\n' && Buf[LineStart-1] != '\r')
1035    --LineStart;
1036  return FilePos-LineStart+1;
1037}
1038
1039// isInvalid - Return the result of calling loc.isInvalid(), and
1040// if Invalid is not null, set its value to same.
1041static bool isInvalid(SourceLocation Loc, bool *Invalid) {
1042  bool MyInvalid = Loc.isInvalid();
1043  if (Invalid)
1044    *Invalid = MyInvalid;
1045  return MyInvalid;
1046}
1047
1048unsigned SourceManager::getSpellingColumnNumber(SourceLocation Loc,
1049                                                bool *Invalid) const {
1050  if (isInvalid(Loc, Invalid)) return 0;
1051  std::pair<FileID, unsigned> LocInfo = getDecomposedSpellingLoc(Loc);
1052  return getColumnNumber(LocInfo.first, LocInfo.second, Invalid);
1053}
1054
1055unsigned SourceManager::getExpansionColumnNumber(SourceLocation Loc,
1056                                                 bool *Invalid) const {
1057  if (isInvalid(Loc, Invalid)) return 0;
1058  std::pair<FileID, unsigned> LocInfo = getDecomposedExpansionLoc(Loc);
1059  return getColumnNumber(LocInfo.first, LocInfo.second, Invalid);
1060}
1061
1062unsigned SourceManager::getPresumedColumnNumber(SourceLocation Loc,
1063                                                bool *Invalid) const {
1064  if (isInvalid(Loc, Invalid)) return 0;
1065  return getPresumedLoc(Loc).getColumn();
1066}
1067
1068#ifdef __SSE2__
1069#include <emmintrin.h>
1070#endif
1071
1072static LLVM_ATTRIBUTE_NOINLINE void
1073ComputeLineNumbers(DiagnosticsEngine &Diag, ContentCache *FI,
1074                   llvm::BumpPtrAllocator &Alloc,
1075                   const SourceManager &SM, bool &Invalid);
1076static void ComputeLineNumbers(DiagnosticsEngine &Diag, ContentCache *FI,
1077                               llvm::BumpPtrAllocator &Alloc,
1078                               const SourceManager &SM, bool &Invalid) {
1079  // Note that calling 'getBuffer()' may lazily page in the file.
1080  const MemoryBuffer *Buffer = FI->getBuffer(Diag, SM, SourceLocation(),
1081                                             &Invalid);
1082  if (Invalid)
1083    return;
1084
1085  // Find the file offsets of all of the *physical* source lines.  This does
1086  // not look at trigraphs, escaped newlines, or anything else tricky.
1087  SmallVector<unsigned, 256> LineOffsets;
1088
1089  // Line #1 starts at char 0.
1090  LineOffsets.push_back(0);
1091
1092  const unsigned char *Buf = (const unsigned char *)Buffer->getBufferStart();
1093  const unsigned char *End = (const unsigned char *)Buffer->getBufferEnd();
1094  unsigned Offs = 0;
1095  while (1) {
1096    // Skip over the contents of the line.
1097    const unsigned char *NextBuf = (const unsigned char *)Buf;
1098
1099#ifdef __SSE2__
1100    // Try to skip to the next newline using SSE instructions. This is very
1101    // performance sensitive for programs with lots of diagnostics and in -E
1102    // mode.
1103    __m128i CRs = _mm_set1_epi8('\r');
1104    __m128i LFs = _mm_set1_epi8('\n');
1105
1106    // First fix up the alignment to 16 bytes.
1107    while (((uintptr_t)NextBuf & 0xF) != 0) {
1108      if (*NextBuf == '\n' || *NextBuf == '\r' || *NextBuf == '\0')
1109        goto FoundSpecialChar;
1110      ++NextBuf;
1111    }
1112
1113    // Scan 16 byte chunks for '\r' and '\n'. Ignore '\0'.
1114    while (NextBuf+16 <= End) {
1115      const __m128i Chunk = *(const __m128i*)NextBuf;
1116      __m128i Cmp = _mm_or_si128(_mm_cmpeq_epi8(Chunk, CRs),
1117                                 _mm_cmpeq_epi8(Chunk, LFs));
1118      unsigned Mask = _mm_movemask_epi8(Cmp);
1119
1120      // If we found a newline, adjust the pointer and jump to the handling code.
1121      if (Mask != 0) {
1122        NextBuf += llvm::CountTrailingZeros_32(Mask);
1123        goto FoundSpecialChar;
1124      }
1125      NextBuf += 16;
1126    }
1127#endif
1128
1129    while (*NextBuf != '\n' && *NextBuf != '\r' && *NextBuf != '\0')
1130      ++NextBuf;
1131
1132#ifdef __SSE2__
1133FoundSpecialChar:
1134#endif
1135    Offs += NextBuf-Buf;
1136    Buf = NextBuf;
1137
1138    if (Buf[0] == '\n' || Buf[0] == '\r') {
1139      // If this is \n\r or \r\n, skip both characters.
1140      if ((Buf[1] == '\n' || Buf[1] == '\r') && Buf[0] != Buf[1])
1141        ++Offs, ++Buf;
1142      ++Offs, ++Buf;
1143      LineOffsets.push_back(Offs);
1144    } else {
1145      // Otherwise, this is a null.  If end of file, exit.
1146      if (Buf == End) break;
1147      // Otherwise, skip the null.
1148      ++Offs, ++Buf;
1149    }
1150  }
1151
1152  // Copy the offsets into the FileInfo structure.
1153  FI->NumLines = LineOffsets.size();
1154  FI->SourceLineCache = Alloc.Allocate<unsigned>(LineOffsets.size());
1155  std::copy(LineOffsets.begin(), LineOffsets.end(), FI->SourceLineCache);
1156}
1157
1158/// getLineNumber - Given a SourceLocation, return the spelling line number
1159/// for the position indicated.  This requires building and caching a table of
1160/// line offsets for the MemoryBuffer, so this is not cheap: use only when
1161/// about to emit a diagnostic.
1162unsigned SourceManager::getLineNumber(FileID FID, unsigned FilePos,
1163                                      bool *Invalid) const {
1164  if (FID.isInvalid()) {
1165    if (Invalid)
1166      *Invalid = true;
1167    return 1;
1168  }
1169
1170  ContentCache *Content;
1171  if (LastLineNoFileIDQuery == FID)
1172    Content = LastLineNoContentCache;
1173  else {
1174    bool MyInvalid = false;
1175    const SLocEntry &Entry = getSLocEntry(FID, &MyInvalid);
1176    if (MyInvalid || !Entry.isFile()) {
1177      if (Invalid)
1178        *Invalid = true;
1179      return 1;
1180    }
1181
1182    Content = const_cast<ContentCache*>(Entry.getFile().getContentCache());
1183  }
1184
1185  // If this is the first use of line information for this buffer, compute the
1186  /// SourceLineCache for it on demand.
1187  if (Content->SourceLineCache == 0) {
1188    bool MyInvalid = false;
1189    ComputeLineNumbers(Diag, Content, ContentCacheAlloc, *this, MyInvalid);
1190    if (Invalid)
1191      *Invalid = MyInvalid;
1192    if (MyInvalid)
1193      return 1;
1194  } else if (Invalid)
1195    *Invalid = false;
1196
1197  // Okay, we know we have a line number table.  Do a binary search to find the
1198  // line number that this character position lands on.
1199  unsigned *SourceLineCache = Content->SourceLineCache;
1200  unsigned *SourceLineCacheStart = SourceLineCache;
1201  unsigned *SourceLineCacheEnd = SourceLineCache + Content->NumLines;
1202
1203  unsigned QueriedFilePos = FilePos+1;
1204
1205  // FIXME: I would like to be convinced that this code is worth being as
1206  // complicated as it is, binary search isn't that slow.
1207  //
1208  // If it is worth being optimized, then in my opinion it could be more
1209  // performant, simpler, and more obviously correct by just "galloping" outward
1210  // from the queried file position. In fact, this could be incorporated into a
1211  // generic algorithm such as lower_bound_with_hint.
1212  //
1213  // If someone gives me a test case where this matters, and I will do it! - DWD
1214
1215  // If the previous query was to the same file, we know both the file pos from
1216  // that query and the line number returned.  This allows us to narrow the
1217  // search space from the entire file to something near the match.
1218  if (LastLineNoFileIDQuery == FID) {
1219    if (QueriedFilePos >= LastLineNoFilePos) {
1220      // FIXME: Potential overflow?
1221      SourceLineCache = SourceLineCache+LastLineNoResult-1;
1222
1223      // The query is likely to be nearby the previous one.  Here we check to
1224      // see if it is within 5, 10 or 20 lines.  It can be far away in cases
1225      // where big comment blocks and vertical whitespace eat up lines but
1226      // contribute no tokens.
1227      if (SourceLineCache+5 < SourceLineCacheEnd) {
1228        if (SourceLineCache[5] > QueriedFilePos)
1229          SourceLineCacheEnd = SourceLineCache+5;
1230        else if (SourceLineCache+10 < SourceLineCacheEnd) {
1231          if (SourceLineCache[10] > QueriedFilePos)
1232            SourceLineCacheEnd = SourceLineCache+10;
1233          else if (SourceLineCache+20 < SourceLineCacheEnd) {
1234            if (SourceLineCache[20] > QueriedFilePos)
1235              SourceLineCacheEnd = SourceLineCache+20;
1236          }
1237        }
1238      }
1239    } else {
1240      if (LastLineNoResult < Content->NumLines)
1241        SourceLineCacheEnd = SourceLineCache+LastLineNoResult+1;
1242    }
1243  }
1244
1245  // If the spread is large, do a "radix" test as our initial guess, based on
1246  // the assumption that lines average to approximately the same length.
1247  // NOTE: This is currently disabled, as it does not appear to be profitable in
1248  // initial measurements.
1249  if (0 && SourceLineCacheEnd-SourceLineCache > 20) {
1250    unsigned FileLen = Content->SourceLineCache[Content->NumLines-1];
1251
1252    // Take a stab at guessing where it is.
1253    unsigned ApproxPos = Content->NumLines*QueriedFilePos / FileLen;
1254
1255    // Check for -10 and +10 lines.
1256    unsigned LowerBound = std::max(int(ApproxPos-10), 0);
1257    unsigned UpperBound = std::min(ApproxPos+10, FileLen);
1258
1259    // If the computed lower bound is less than the query location, move it in.
1260    if (SourceLineCache < SourceLineCacheStart+LowerBound &&
1261        SourceLineCacheStart[LowerBound] < QueriedFilePos)
1262      SourceLineCache = SourceLineCacheStart+LowerBound;
1263
1264    // If the computed upper bound is greater than the query location, move it.
1265    if (SourceLineCacheEnd > SourceLineCacheStart+UpperBound &&
1266        SourceLineCacheStart[UpperBound] >= QueriedFilePos)
1267      SourceLineCacheEnd = SourceLineCacheStart+UpperBound;
1268  }
1269
1270  unsigned *Pos
1271    = std::lower_bound(SourceLineCache, SourceLineCacheEnd, QueriedFilePos);
1272  unsigned LineNo = Pos-SourceLineCacheStart;
1273
1274  LastLineNoFileIDQuery = FID;
1275  LastLineNoContentCache = Content;
1276  LastLineNoFilePos = QueriedFilePos;
1277  LastLineNoResult = LineNo;
1278  return LineNo;
1279}
1280
1281unsigned SourceManager::getSpellingLineNumber(SourceLocation Loc,
1282                                              bool *Invalid) const {
1283  if (isInvalid(Loc, Invalid)) return 0;
1284  std::pair<FileID, unsigned> LocInfo = getDecomposedSpellingLoc(Loc);
1285  return getLineNumber(LocInfo.first, LocInfo.second);
1286}
1287unsigned SourceManager::getExpansionLineNumber(SourceLocation Loc,
1288                                               bool *Invalid) const {
1289  if (isInvalid(Loc, Invalid)) return 0;
1290  std::pair<FileID, unsigned> LocInfo = getDecomposedExpansionLoc(Loc);
1291  return getLineNumber(LocInfo.first, LocInfo.second);
1292}
1293unsigned SourceManager::getPresumedLineNumber(SourceLocation Loc,
1294                                              bool *Invalid) const {
1295  if (isInvalid(Loc, Invalid)) return 0;
1296  return getPresumedLoc(Loc).getLine();
1297}
1298
1299/// getFileCharacteristic - return the file characteristic of the specified
1300/// source location, indicating whether this is a normal file, a system
1301/// header, or an "implicit extern C" system header.
1302///
1303/// This state can be modified with flags on GNU linemarker directives like:
1304///   # 4 "foo.h" 3
1305/// which changes all source locations in the current file after that to be
1306/// considered to be from a system header.
1307SrcMgr::CharacteristicKind
1308SourceManager::getFileCharacteristic(SourceLocation Loc) const {
1309  assert(!Loc.isInvalid() && "Can't get file characteristic of invalid loc!");
1310  std::pair<FileID, unsigned> LocInfo = getDecomposedExpansionLoc(Loc);
1311  bool Invalid = false;
1312  const SLocEntry &SEntry = getSLocEntry(LocInfo.first, &Invalid);
1313  if (Invalid || !SEntry.isFile())
1314    return C_User;
1315
1316  const SrcMgr::FileInfo &FI = SEntry.getFile();
1317
1318  // If there are no #line directives in this file, just return the whole-file
1319  // state.
1320  if (!FI.hasLineDirectives())
1321    return FI.getFileCharacteristic();
1322
1323  assert(LineTable && "Can't have linetable entries without a LineTable!");
1324  // See if there is a #line directive before the location.
1325  const LineEntry *Entry =
1326    LineTable->FindNearestLineEntry(LocInfo.first, LocInfo.second);
1327
1328  // If this is before the first line marker, use the file characteristic.
1329  if (!Entry)
1330    return FI.getFileCharacteristic();
1331
1332  return Entry->FileKind;
1333}
1334
1335/// Return the filename or buffer identifier of the buffer the location is in.
1336/// Note that this name does not respect \#line directives.  Use getPresumedLoc
1337/// for normal clients.
1338const char *SourceManager::getBufferName(SourceLocation Loc,
1339                                         bool *Invalid) const {
1340  if (isInvalid(Loc, Invalid)) return "<invalid loc>";
1341
1342  return getBuffer(getFileID(Loc), Invalid)->getBufferIdentifier();
1343}
1344
1345
1346/// getPresumedLoc - This method returns the "presumed" location of a
1347/// SourceLocation specifies.  A "presumed location" can be modified by \#line
1348/// or GNU line marker directives.  This provides a view on the data that a
1349/// user should see in diagnostics, for example.
1350///
1351/// Note that a presumed location is always given as the expansion point of an
1352/// expansion location, not at the spelling location.
1353PresumedLoc SourceManager::getPresumedLoc(SourceLocation Loc) const {
1354  if (Loc.isInvalid()) return PresumedLoc();
1355
1356  // Presumed locations are always for expansion points.
1357  std::pair<FileID, unsigned> LocInfo = getDecomposedExpansionLoc(Loc);
1358
1359  bool Invalid = false;
1360  const SLocEntry &Entry = getSLocEntry(LocInfo.first, &Invalid);
1361  if (Invalid || !Entry.isFile())
1362    return PresumedLoc();
1363
1364  const SrcMgr::FileInfo &FI = Entry.getFile();
1365  const SrcMgr::ContentCache *C = FI.getContentCache();
1366
1367  // To get the source name, first consult the FileEntry (if one exists)
1368  // before the MemBuffer as this will avoid unnecessarily paging in the
1369  // MemBuffer.
1370  const char *Filename;
1371  if (C->OrigEntry)
1372    Filename = C->OrigEntry->getName();
1373  else
1374    Filename = C->getBuffer(Diag, *this)->getBufferIdentifier();
1375
1376  unsigned LineNo = getLineNumber(LocInfo.first, LocInfo.second, &Invalid);
1377  if (Invalid)
1378    return PresumedLoc();
1379  unsigned ColNo  = getColumnNumber(LocInfo.first, LocInfo.second, &Invalid);
1380  if (Invalid)
1381    return PresumedLoc();
1382
1383  SourceLocation IncludeLoc = FI.getIncludeLoc();
1384
1385  // If we have #line directives in this file, update and overwrite the physical
1386  // location info if appropriate.
1387  if (FI.hasLineDirectives()) {
1388    assert(LineTable && "Can't have linetable entries without a LineTable!");
1389    // See if there is a #line directive before this.  If so, get it.
1390    if (const LineEntry *Entry =
1391          LineTable->FindNearestLineEntry(LocInfo.first, LocInfo.second)) {
1392      // If the LineEntry indicates a filename, use it.
1393      if (Entry->FilenameID != -1)
1394        Filename = LineTable->getFilename(Entry->FilenameID);
1395
1396      // Use the line number specified by the LineEntry.  This line number may
1397      // be multiple lines down from the line entry.  Add the difference in
1398      // physical line numbers from the query point and the line marker to the
1399      // total.
1400      unsigned MarkerLineNo = getLineNumber(LocInfo.first, Entry->FileOffset);
1401      LineNo = Entry->LineNo + (LineNo-MarkerLineNo-1);
1402
1403      // Note that column numbers are not molested by line markers.
1404
1405      // Handle virtual #include manipulation.
1406      if (Entry->IncludeOffset) {
1407        IncludeLoc = getLocForStartOfFile(LocInfo.first);
1408        IncludeLoc = IncludeLoc.getLocWithOffset(Entry->IncludeOffset);
1409      }
1410    }
1411  }
1412
1413  return PresumedLoc(Filename, LineNo, ColNo, IncludeLoc);
1414}
1415
1416/// \brief The size of the SLocEnty that \arg FID represents.
1417unsigned SourceManager::getFileIDSize(FileID FID) const {
1418  bool Invalid = false;
1419  const SrcMgr::SLocEntry &Entry = getSLocEntry(FID, &Invalid);
1420  if (Invalid)
1421    return 0;
1422
1423  int ID = FID.ID;
1424  unsigned NextOffset;
1425  if ((ID > 0 && unsigned(ID+1) == local_sloc_entry_size()))
1426    NextOffset = getNextLocalOffset();
1427  else if (ID+1 == -1)
1428    NextOffset = MaxLoadedOffset;
1429  else
1430    NextOffset = getSLocEntry(FileID::get(ID+1)).getOffset();
1431
1432  return NextOffset - Entry.getOffset() - 1;
1433}
1434
1435//===----------------------------------------------------------------------===//
1436// Other miscellaneous methods.
1437//===----------------------------------------------------------------------===//
1438
1439/// \brief Retrieve the inode for the given file entry, if possible.
1440///
1441/// This routine involves a system call, and therefore should only be used
1442/// in non-performance-critical code.
1443static llvm::Optional<ino_t> getActualFileInode(const FileEntry *File) {
1444  if (!File)
1445    return llvm::Optional<ino_t>();
1446
1447  struct stat StatBuf;
1448  if (::stat(File->getName(), &StatBuf))
1449    return llvm::Optional<ino_t>();
1450
1451  return StatBuf.st_ino;
1452}
1453
1454/// \brief Get the source location for the given file:line:col triplet.
1455///
1456/// If the source file is included multiple times, the source location will
1457/// be based upon an arbitrary inclusion.
1458SourceLocation SourceManager::translateFileLineCol(const FileEntry *SourceFile,
1459                                                  unsigned Line,
1460                                                  unsigned Col) const {
1461  assert(SourceFile && "Null source file!");
1462  assert(Line && Col && "Line and column should start from 1!");
1463
1464  FileID FirstFID = translateFile(SourceFile);
1465  return translateLineCol(FirstFID, Line, Col);
1466}
1467
1468/// \brief Get the FileID for the given file.
1469///
1470/// If the source file is included multiple times, the FileID will be the
1471/// first inclusion.
1472FileID SourceManager::translateFile(const FileEntry *SourceFile) const {
1473  assert(SourceFile && "Null source file!");
1474
1475  // Find the first file ID that corresponds to the given file.
1476  FileID FirstFID;
1477
1478  // First, check the main file ID, since it is common to look for a
1479  // location in the main file.
1480  llvm::Optional<ino_t> SourceFileInode;
1481  llvm::Optional<StringRef> SourceFileName;
1482  if (!MainFileID.isInvalid()) {
1483    bool Invalid = false;
1484    const SLocEntry &MainSLoc = getSLocEntry(MainFileID, &Invalid);
1485    if (Invalid)
1486      return FileID();
1487
1488    if (MainSLoc.isFile()) {
1489      const ContentCache *MainContentCache
1490        = MainSLoc.getFile().getContentCache();
1491      if (!MainContentCache) {
1492        // Can't do anything
1493      } else if (MainContentCache->OrigEntry == SourceFile) {
1494        FirstFID = MainFileID;
1495      } else {
1496        // Fall back: check whether we have the same base name and inode
1497        // as the main file.
1498        const FileEntry *MainFile = MainContentCache->OrigEntry;
1499        SourceFileName = llvm::sys::path::filename(SourceFile->getName());
1500        if (*SourceFileName == llvm::sys::path::filename(MainFile->getName())) {
1501          SourceFileInode = getActualFileInode(SourceFile);
1502          if (SourceFileInode) {
1503            if (llvm::Optional<ino_t> MainFileInode
1504                                               = getActualFileInode(MainFile)) {
1505              if (*SourceFileInode == *MainFileInode) {
1506                FirstFID = MainFileID;
1507                SourceFile = MainFile;
1508              }
1509            }
1510          }
1511        }
1512      }
1513    }
1514  }
1515
1516  if (FirstFID.isInvalid()) {
1517    // The location we're looking for isn't in the main file; look
1518    // through all of the local source locations.
1519    for (unsigned I = 0, N = local_sloc_entry_size(); I != N; ++I) {
1520      bool Invalid = false;
1521      const SLocEntry &SLoc = getLocalSLocEntry(I, &Invalid);
1522      if (Invalid)
1523        return FileID();
1524
1525      if (SLoc.isFile() &&
1526          SLoc.getFile().getContentCache() &&
1527          SLoc.getFile().getContentCache()->OrigEntry == SourceFile) {
1528        FirstFID = FileID::get(I);
1529        break;
1530      }
1531    }
1532    // If that still didn't help, try the modules.
1533    if (FirstFID.isInvalid()) {
1534      for (unsigned I = 0, N = loaded_sloc_entry_size(); I != N; ++I) {
1535        const SLocEntry &SLoc = getLoadedSLocEntry(I);
1536        if (SLoc.isFile() &&
1537            SLoc.getFile().getContentCache() &&
1538            SLoc.getFile().getContentCache()->OrigEntry == SourceFile) {
1539          FirstFID = FileID::get(-int(I) - 2);
1540          break;
1541        }
1542      }
1543    }
1544  }
1545
1546  // If we haven't found what we want yet, try again, but this time stat()
1547  // each of the files in case the files have changed since we originally
1548  // parsed the file.
1549  if (FirstFID.isInvalid() &&
1550      (SourceFileName ||
1551       (SourceFileName = llvm::sys::path::filename(SourceFile->getName()))) &&
1552      (SourceFileInode ||
1553       (SourceFileInode = getActualFileInode(SourceFile)))) {
1554    bool Invalid = false;
1555    for (unsigned I = 0, N = local_sloc_entry_size(); I != N; ++I) {
1556      FileID IFileID;
1557      IFileID.ID = I;
1558      const SLocEntry &SLoc = getSLocEntry(IFileID, &Invalid);
1559      if (Invalid)
1560        return FileID();
1561
1562      if (SLoc.isFile()) {
1563        const ContentCache *FileContentCache
1564          = SLoc.getFile().getContentCache();
1565      const FileEntry *Entry =FileContentCache? FileContentCache->OrigEntry : 0;
1566        if (Entry &&
1567            *SourceFileName == llvm::sys::path::filename(Entry->getName())) {
1568          if (llvm::Optional<ino_t> EntryInode = getActualFileInode(Entry)) {
1569            if (*SourceFileInode == *EntryInode) {
1570              FirstFID = FileID::get(I);
1571              SourceFile = Entry;
1572              break;
1573            }
1574          }
1575        }
1576      }
1577    }
1578  }
1579
1580  return FirstFID;
1581}
1582
1583/// \brief Get the source location in \arg FID for the given line:col.
1584/// Returns null location if \arg FID is not a file SLocEntry.
1585SourceLocation SourceManager::translateLineCol(FileID FID,
1586                                               unsigned Line,
1587                                               unsigned Col) const {
1588  if (FID.isInvalid())
1589    return SourceLocation();
1590
1591  bool Invalid = false;
1592  const SLocEntry &Entry = getSLocEntry(FID, &Invalid);
1593  if (Invalid)
1594    return SourceLocation();
1595
1596  if (!Entry.isFile())
1597    return SourceLocation();
1598
1599  SourceLocation FileLoc = SourceLocation::getFileLoc(Entry.getOffset());
1600
1601  if (Line == 1 && Col == 1)
1602    return FileLoc;
1603
1604  ContentCache *Content
1605    = const_cast<ContentCache *>(Entry.getFile().getContentCache());
1606  if (!Content)
1607    return SourceLocation();
1608
1609  // If this is the first use of line information for this buffer, compute the
1610  // SourceLineCache for it on demand.
1611  if (Content->SourceLineCache == 0) {
1612    bool MyInvalid = false;
1613    ComputeLineNumbers(Diag, Content, ContentCacheAlloc, *this, MyInvalid);
1614    if (MyInvalid)
1615      return SourceLocation();
1616  }
1617
1618  if (Line > Content->NumLines) {
1619    unsigned Size = Content->getBuffer(Diag, *this)->getBufferSize();
1620    if (Size > 0)
1621      --Size;
1622    return FileLoc.getLocWithOffset(Size);
1623  }
1624
1625  const llvm::MemoryBuffer *Buffer = Content->getBuffer(Diag, *this);
1626  unsigned FilePos = Content->SourceLineCache[Line - 1];
1627  const char *Buf = Buffer->getBufferStart() + FilePos;
1628  unsigned BufLength = Buffer->getBufferSize() - FilePos;
1629  if (BufLength == 0)
1630    return FileLoc.getLocWithOffset(FilePos);
1631
1632  unsigned i = 0;
1633
1634  // Check that the given column is valid.
1635  while (i < BufLength-1 && i < Col-1 && Buf[i] != '\n' && Buf[i] != '\r')
1636    ++i;
1637  if (i < Col-1)
1638    return FileLoc.getLocWithOffset(FilePos + i);
1639
1640  return FileLoc.getLocWithOffset(FilePos + Col - 1);
1641}
1642
1643/// \brief Compute a map of macro argument chunks to their expanded source
1644/// location. Chunks that are not part of a macro argument will map to an
1645/// invalid source location. e.g. if a file contains one macro argument at
1646/// offset 100 with length 10, this is how the map will be formed:
1647///     0   -> SourceLocation()
1648///     100 -> Expanded macro arg location
1649///     110 -> SourceLocation()
1650void SourceManager::computeMacroArgsCache(MacroArgsMap *&CachePtr,
1651                                          FileID FID) const {
1652  assert(!FID.isInvalid());
1653  assert(!CachePtr);
1654
1655  CachePtr = new MacroArgsMap();
1656  MacroArgsMap &MacroArgsCache = *CachePtr;
1657  // Initially no macro argument chunk is present.
1658  MacroArgsCache.insert(std::make_pair(0, SourceLocation()));
1659
1660  int ID = FID.ID;
1661  while (1) {
1662    ++ID;
1663    // Stop if there are no more FileIDs to check.
1664    if (ID > 0) {
1665      if (unsigned(ID) >= local_sloc_entry_size())
1666        return;
1667    } else if (ID == -1) {
1668      return;
1669    }
1670
1671    const SrcMgr::SLocEntry &Entry = getSLocEntryByID(ID);
1672    if (Entry.isFile()) {
1673      SourceLocation IncludeLoc = Entry.getFile().getIncludeLoc();
1674      if (IncludeLoc.isInvalid())
1675        continue;
1676      if (!isInFileID(IncludeLoc, FID))
1677        return; // No more files/macros that may be "contained" in this file.
1678
1679      // Skip the files/macros of the #include'd file, we only care about macros
1680      // that lexed macro arguments from our file.
1681      if (Entry.getFile().NumCreatedFIDs)
1682        ID += Entry.getFile().NumCreatedFIDs - 1/*because of next ++ID*/;
1683      continue;
1684    }
1685
1686    const ExpansionInfo &ExpInfo = Entry.getExpansion();
1687
1688    if (ExpInfo.getExpansionLocStart().isFileID()) {
1689      if (!isInFileID(ExpInfo.getExpansionLocStart(), FID))
1690        return; // No more files/macros that may be "contained" in this file.
1691    }
1692
1693    if (!ExpInfo.isMacroArgExpansion())
1694      continue;
1695
1696    SourceLocation SpellLoc = ExpInfo.getSpellingLoc();
1697    while (!SpellLoc.isFileID()) {
1698      std::pair<FileID, unsigned> LocInfo = getDecomposedLoc(SpellLoc);
1699      const ExpansionInfo &Info = getSLocEntry(LocInfo.first).getExpansion();
1700      if (!Info.isMacroArgExpansion())
1701        break;
1702      SpellLoc = Info.getSpellingLoc().getLocWithOffset(LocInfo.second);
1703    }
1704    if (!SpellLoc.isFileID())
1705      continue;
1706
1707    unsigned BeginOffs;
1708    if (!isInFileID(SpellLoc, FID, &BeginOffs))
1709      continue;
1710
1711    unsigned EndOffs = BeginOffs + getFileIDSize(FileID::get(ID));
1712
1713    // Add a new chunk for this macro argument. A previous macro argument chunk
1714    // may have been lexed again, so e.g. if the map is
1715    //     0   -> SourceLocation()
1716    //     100 -> Expanded loc #1
1717    //     110 -> SourceLocation()
1718    // and we found a new macro FileID that lexed from offet 105 with length 3,
1719    // the new map will be:
1720    //     0   -> SourceLocation()
1721    //     100 -> Expanded loc #1
1722    //     105 -> Expanded loc #2
1723    //     108 -> Expanded loc #1
1724    //     110 -> SourceLocation()
1725    //
1726    // Since re-lexed macro chunks will always be the same size or less of
1727    // previous chunks, we only need to find where the ending of the new macro
1728    // chunk is mapped to and update the map with new begin/end mappings.
1729
1730    MacroArgsMap::iterator I = MacroArgsCache.upper_bound(EndOffs);
1731    --I;
1732    SourceLocation EndOffsMappedLoc = I->second;
1733    MacroArgsCache[BeginOffs] = SourceLocation::getMacroLoc(Entry.getOffset());
1734    MacroArgsCache[EndOffs] = EndOffsMappedLoc;
1735  }
1736}
1737
1738/// \brief If \arg Loc points inside a function macro argument, the returned
1739/// location will be the macro location in which the argument was expanded.
1740/// If a macro argument is used multiple times, the expanded location will
1741/// be at the first expansion of the argument.
1742/// e.g.
1743///   MY_MACRO(foo);
1744///             ^
1745/// Passing a file location pointing at 'foo', will yield a macro location
1746/// where 'foo' was expanded into.
1747SourceLocation
1748SourceManager::getMacroArgExpandedLocation(SourceLocation Loc) const {
1749  if (Loc.isInvalid() || !Loc.isFileID())
1750    return Loc;
1751
1752  FileID FID;
1753  unsigned Offset;
1754  llvm::tie(FID, Offset) = getDecomposedLoc(Loc);
1755  if (FID.isInvalid())
1756    return Loc;
1757
1758  MacroArgsMap *&MacroArgsCache = MacroArgsCacheMap[FID];
1759  if (!MacroArgsCache)
1760    computeMacroArgsCache(MacroArgsCache, FID);
1761
1762  assert(!MacroArgsCache->empty());
1763  MacroArgsMap::iterator I = MacroArgsCache->upper_bound(Offset);
1764  --I;
1765
1766  unsigned MacroArgBeginOffs = I->first;
1767  SourceLocation MacroArgExpandedLoc = I->second;
1768  if (MacroArgExpandedLoc.isValid())
1769    return MacroArgExpandedLoc.getLocWithOffset(Offset - MacroArgBeginOffs);
1770
1771  return Loc;
1772}
1773
1774/// Given a decomposed source location, move it up the include/expansion stack
1775/// to the parent source location.  If this is possible, return the decomposed
1776/// version of the parent in Loc and return false.  If Loc is the top-level
1777/// entry, return true and don't modify it.
1778static bool MoveUpIncludeHierarchy(std::pair<FileID, unsigned> &Loc,
1779                                   const SourceManager &SM) {
1780  SourceLocation UpperLoc;
1781  const SrcMgr::SLocEntry &Entry = SM.getSLocEntry(Loc.first);
1782  if (Entry.isExpansion())
1783    UpperLoc = Entry.getExpansion().getExpansionLocStart();
1784  else
1785    UpperLoc = Entry.getFile().getIncludeLoc();
1786
1787  if (UpperLoc.isInvalid())
1788    return true; // We reached the top.
1789
1790  Loc = SM.getDecomposedLoc(UpperLoc);
1791  return false;
1792}
1793
1794
1795/// \brief Determines the order of 2 source locations in the translation unit.
1796///
1797/// \returns true if LHS source location comes before RHS, false otherwise.
1798bool SourceManager::isBeforeInTranslationUnit(SourceLocation LHS,
1799                                              SourceLocation RHS) const {
1800  assert(LHS.isValid() && RHS.isValid() && "Passed invalid source location!");
1801  if (LHS == RHS)
1802    return false;
1803
1804  std::pair<FileID, unsigned> LOffs = getDecomposedLoc(LHS);
1805  std::pair<FileID, unsigned> ROffs = getDecomposedLoc(RHS);
1806
1807  // If the source locations are in the same file, just compare offsets.
1808  if (LOffs.first == ROffs.first)
1809    return LOffs.second < ROffs.second;
1810
1811  // If we are comparing a source location with multiple locations in the same
1812  // file, we get a big win by caching the result.
1813  if (IsBeforeInTUCache.isCacheValid(LOffs.first, ROffs.first))
1814    return IsBeforeInTUCache.getCachedResult(LOffs.second, ROffs.second);
1815
1816  // Okay, we missed in the cache, start updating the cache for this query.
1817  IsBeforeInTUCache.setQueryFIDs(LOffs.first, ROffs.first,
1818                          /*isLFIDBeforeRFID=*/LOffs.first.ID < ROffs.first.ID);
1819
1820  // We need to find the common ancestor. The only way of doing this is to
1821  // build the complete include chain for one and then walking up the chain
1822  // of the other looking for a match.
1823  // We use a map from FileID to Offset to store the chain. Easier than writing
1824  // a custom set hash info that only depends on the first part of a pair.
1825  typedef llvm::DenseMap<FileID, unsigned> LocSet;
1826  LocSet LChain;
1827  do {
1828    LChain.insert(LOffs);
1829    // We catch the case where LOffs is in a file included by ROffs and
1830    // quit early. The other way round unfortunately remains suboptimal.
1831  } while (LOffs.first != ROffs.first && !MoveUpIncludeHierarchy(LOffs, *this));
1832  LocSet::iterator I;
1833  while((I = LChain.find(ROffs.first)) == LChain.end()) {
1834    if (MoveUpIncludeHierarchy(ROffs, *this))
1835      break; // Met at topmost file.
1836  }
1837  if (I != LChain.end())
1838    LOffs = *I;
1839
1840  // If we exited because we found a nearest common ancestor, compare the
1841  // locations within the common file and cache them.
1842  if (LOffs.first == ROffs.first) {
1843    IsBeforeInTUCache.setCommonLoc(LOffs.first, LOffs.second, ROffs.second);
1844    return IsBeforeInTUCache.getCachedResult(LOffs.second, ROffs.second);
1845  }
1846
1847  // This can happen if a location is in a built-ins buffer.
1848  // But see PR5662.
1849  // Clear the lookup cache, it depends on a common location.
1850  IsBeforeInTUCache.clear();
1851  bool LIsBuiltins = strcmp("<built-in>",
1852                            getBuffer(LOffs.first)->getBufferIdentifier()) == 0;
1853  bool RIsBuiltins = strcmp("<built-in>",
1854                            getBuffer(ROffs.first)->getBufferIdentifier()) == 0;
1855  // built-in is before non-built-in
1856  if (LIsBuiltins != RIsBuiltins)
1857    return LIsBuiltins;
1858  assert(LIsBuiltins && RIsBuiltins &&
1859         "Non-built-in locations must be rooted in the main file");
1860  // Both are in built-in buffers, but from different files. We just claim that
1861  // lower IDs come first.
1862  return LOffs.first < ROffs.first;
1863}
1864
1865void SourceManager::PrintStats() const {
1866  llvm::errs() << "\n*** Source Manager Stats:\n";
1867  llvm::errs() << FileInfos.size() << " files mapped, " << MemBufferInfos.size()
1868               << " mem buffers mapped.\n";
1869  llvm::errs() << LocalSLocEntryTable.size() << " local SLocEntry's allocated ("
1870               << llvm::capacity_in_bytes(LocalSLocEntryTable)
1871               << " bytes of capacity), "
1872               << NextLocalOffset << "B of Sloc address space used.\n";
1873  llvm::errs() << LoadedSLocEntryTable.size()
1874               << " loaded SLocEntries allocated, "
1875               << MaxLoadedOffset - CurrentLoadedOffset
1876               << "B of Sloc address space used.\n";
1877
1878  unsigned NumLineNumsComputed = 0;
1879  unsigned NumFileBytesMapped = 0;
1880  for (fileinfo_iterator I = fileinfo_begin(), E = fileinfo_end(); I != E; ++I){
1881    NumLineNumsComputed += I->second->SourceLineCache != 0;
1882    NumFileBytesMapped  += I->second->getSizeBytesMapped();
1883  }
1884  unsigned NumMacroArgsComputed = MacroArgsCacheMap.size();
1885
1886  llvm::errs() << NumFileBytesMapped << " bytes of files mapped, "
1887               << NumLineNumsComputed << " files with line #'s computed, "
1888               << NumMacroArgsComputed << " files with macro args computed.\n";
1889  llvm::errs() << "FileID scans: " << NumLinearScans << " linear, "
1890               << NumBinaryProbes << " binary.\n";
1891}
1892
1893ExternalSLocEntrySource::~ExternalSLocEntrySource() { }
1894
1895/// Return the amount of memory used by memory buffers, breaking down
1896/// by heap-backed versus mmap'ed memory.
1897SourceManager::MemoryBufferSizes SourceManager::getMemoryBufferSizes() const {
1898  size_t malloc_bytes = 0;
1899  size_t mmap_bytes = 0;
1900
1901  for (unsigned i = 0, e = MemBufferInfos.size(); i != e; ++i)
1902    if (size_t sized_mapped = MemBufferInfos[i]->getSizeBytesMapped())
1903      switch (MemBufferInfos[i]->getMemoryBufferKind()) {
1904        case llvm::MemoryBuffer::MemoryBuffer_MMap:
1905          mmap_bytes += sized_mapped;
1906          break;
1907        case llvm::MemoryBuffer::MemoryBuffer_Malloc:
1908          malloc_bytes += sized_mapped;
1909          break;
1910      }
1911
1912  return MemoryBufferSizes(malloc_bytes, mmap_bytes);
1913}
1914
1915size_t SourceManager::getDataStructureSizes() const {
1916  size_t size = llvm::capacity_in_bytes(MemBufferInfos)
1917    + llvm::capacity_in_bytes(LocalSLocEntryTable)
1918    + llvm::capacity_in_bytes(LoadedSLocEntryTable)
1919    + llvm::capacity_in_bytes(SLocEntryLoaded)
1920    + llvm::capacity_in_bytes(FileInfos);
1921
1922  if (OverriddenFilesInfo)
1923    size += llvm::capacity_in_bytes(OverriddenFilesInfo->OverriddenFiles);
1924
1925  return size;
1926}
1927