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llvm-project/clang/lib/Basic/SourceManager.cpp

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//===--- SourceManager.cpp - Track and cache source files -----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the SourceManager interface.
//
//===----------------------------------------------------------------------===//
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/SourceManagerInternals.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/FileManager.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/Optional.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/Path.h"
#include <algorithm>
#include <string>
#include <cstring>
#include <sys/stat.h>
using namespace clang;
using namespace SrcMgr;
using llvm::MemoryBuffer;
//===----------------------------------------------------------------------===//
// SourceManager Helper Classes
//===----------------------------------------------------------------------===//
ContentCache::~ContentCache() {
if (shouldFreeBuffer())
delete Buffer.getPointer();
}
/// getSizeBytesMapped - Returns the number of bytes actually mapped for
/// this ContentCache. This can be 0 if the MemBuffer was not actually
/// instantiated.
unsigned ContentCache::getSizeBytesMapped() const {
return Buffer.getPointer() ? Buffer.getPointer()->getBufferSize() : 0;
}
/// 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, that
/// file is not lazily brought in from disk to satisfy this query.
unsigned ContentCache::getSize() const {
return Buffer.getPointer() ? (unsigned) Buffer.getPointer()->getBufferSize()
: (unsigned) ContentsEntry->getSize();
}
void ContentCache::replaceBuffer(const llvm::MemoryBuffer *B,
bool DoNotFree) {
assert(B != Buffer.getPointer());
if (shouldFreeBuffer())
delete Buffer.getPointer();
Buffer.setPointer(B);
Buffer.setInt(DoNotFree? DoNotFreeFlag : 0);
}
const llvm::MemoryBuffer *ContentCache::getBuffer(Diagnostic &Diag,
const SourceManager &SM,
SourceLocation Loc,
bool *Invalid) const {
// Lazily create the Buffer for ContentCaches that wrap files. If we already
// computed it, just return what we have.
if (Buffer.getPointer() || ContentsEntry == 0) {
if (Invalid)
*Invalid = isBufferInvalid();
return Buffer.getPointer();
}
std::string ErrorStr;
Buffer.setPointer(SM.getFileManager().getBufferForFile(ContentsEntry, &ErrorStr));
// If we were unable to open the file, then we are in an inconsistent
// situation where the content cache referenced a file which no longer
// exists. Most likely, we were using a stat cache with an invalid entry but
// the file could also have been removed during processing. Since we can't
// really deal with this situation, just create an empty buffer.
//
// FIXME: This is definitely not ideal, but our immediate clients can't
// currently handle returning a null entry here. Ideally we should detect
// that we are in an inconsistent situation and error out as quickly as
// possible.
if (!Buffer.getPointer()) {
const llvm::StringRef FillStr("<<<MISSING SOURCE FILE>>>\n");
Buffer.setPointer(MemoryBuffer::getNewMemBuffer(ContentsEntry->getSize(),
"<invalid>"));
char *Ptr = const_cast<char*>(Buffer.getPointer()->getBufferStart());
for (unsigned i = 0, e = ContentsEntry->getSize(); i != e; ++i)
Ptr[i] = FillStr[i % FillStr.size()];
if (Diag.isDiagnosticInFlight())
Diag.SetDelayedDiagnostic(diag::err_cannot_open_file,
ContentsEntry->getName(), ErrorStr);
else
Diag.Report(Loc, diag::err_cannot_open_file)
<< ContentsEntry->getName() << ErrorStr;
Buffer.setInt(Buffer.getInt() | InvalidFlag);
if (Invalid) *Invalid = true;
return Buffer.getPointer();
}
// Check that the file's size is the same as in the file entry (which may
// have come from a stat cache).
if (getRawBuffer()->getBufferSize() != (size_t)ContentsEntry->getSize()) {
if (Diag.isDiagnosticInFlight())
Diag.SetDelayedDiagnostic(diag::err_file_modified,
ContentsEntry->getName());
else
Diag.Report(Loc, diag::err_file_modified)
<< ContentsEntry->getName();
Buffer.setInt(Buffer.getInt() | InvalidFlag);
if (Invalid) *Invalid = true;
return Buffer.getPointer();
}
// If the buffer is valid, check to see if it has a UTF Byte Order Mark
// (BOM). We only support UTF-8 with and without a BOM right now. See
// http://en.wikipedia.org/wiki/Byte_order_mark for more information.
llvm::StringRef BufStr = Buffer.getPointer()->getBuffer();
const char *InvalidBOM = llvm::StringSwitch<const char *>(BufStr)
.StartsWith("\xFE\xFF", "UTF-16 (BE)")
.StartsWith("\xFF\xFE", "UTF-16 (LE)")
.StartsWith("\x00\x00\xFE\xFF", "UTF-32 (BE)")
.StartsWith("\xFF\xFE\x00\x00", "UTF-32 (LE)")
.StartsWith("\x2B\x2F\x76", "UTF-7")
.StartsWith("\xF7\x64\x4C", "UTF-1")
.StartsWith("\xDD\x73\x66\x73", "UTF-EBCDIC")
.StartsWith("\x0E\xFE\xFF", "SDSU")
.StartsWith("\xFB\xEE\x28", "BOCU-1")
.StartsWith("\x84\x31\x95\x33", "GB-18030")
.Default(0);
if (InvalidBOM) {
Diag.Report(Loc, diag::err_unsupported_bom)
<< InvalidBOM << ContentsEntry->getName();
Buffer.setInt(Buffer.getInt() | InvalidFlag);
}
if (Invalid)
*Invalid = isBufferInvalid();
return Buffer.getPointer();
}
unsigned LineTableInfo::getLineTableFilenameID(const char *Ptr, unsigned Len) {
// Look up the filename in the string table, returning the pre-existing value
// if it exists.
llvm::StringMapEntry<unsigned> &Entry =
FilenameIDs.GetOrCreateValue(Ptr, Ptr+Len, ~0U);
if (Entry.getValue() != ~0U)
return Entry.getValue();
// Otherwise, assign this the next available ID.
Entry.setValue(FilenamesByID.size());
FilenamesByID.push_back(&Entry);
return FilenamesByID.size()-1;
}
/// AddLineNote - Add a line note to the line table that indicates that there
/// is a #line at the specified FID/Offset location which changes the presumed
/// location to LineNo/FilenameID.
void LineTableInfo::AddLineNote(unsigned FID, unsigned Offset,
unsigned LineNo, int FilenameID) {
std::vector<LineEntry> &Entries = LineEntries[FID];
assert((Entries.empty() || Entries.back().FileOffset < Offset) &&
"Adding line entries out of order!");
SrcMgr::CharacteristicKind Kind = SrcMgr::C_User;
unsigned IncludeOffset = 0;
if (!Entries.empty()) {
// If this is a '#line 4' after '#line 42 "foo.h"', make sure to remember
// that we are still in "foo.h".
if (FilenameID == -1)
FilenameID = Entries.back().FilenameID;
// If we are after a line marker that switched us to system header mode, or
// that set #include information, preserve it.
Kind = Entries.back().FileKind;
IncludeOffset = Entries.back().IncludeOffset;
}
Entries.push_back(LineEntry::get(Offset, LineNo, FilenameID, Kind,
IncludeOffset));
}
/// AddLineNote This is the same as the previous version of AddLineNote, but is
/// used for GNU line markers. If EntryExit is 0, then this doesn't change the
/// presumed #include stack. If it is 1, this is a file entry, if it is 2 then
/// this is a file exit. FileKind specifies whether this is a system header or
/// extern C system header.
void LineTableInfo::AddLineNote(unsigned FID, unsigned Offset,
unsigned LineNo, int FilenameID,
unsigned EntryExit,
SrcMgr::CharacteristicKind FileKind) {
assert(FilenameID != -1 && "Unspecified filename should use other accessor");
std::vector<LineEntry> &Entries = LineEntries[FID];
assert((Entries.empty() || Entries.back().FileOffset < Offset) &&
"Adding line entries out of order!");
unsigned IncludeOffset = 0;
if (EntryExit == 0) { // No #include stack change.
IncludeOffset = Entries.empty() ? 0 : Entries.back().IncludeOffset;
} else if (EntryExit == 1) {
IncludeOffset = Offset-1;
} else if (EntryExit == 2) {
assert(!Entries.empty() && Entries.back().IncludeOffset &&
"PPDirectives should have caught case when popping empty include stack");
// Get the include loc of the last entries' include loc as our include loc.
IncludeOffset = 0;
if (const LineEntry *PrevEntry =
FindNearestLineEntry(FID, Entries.back().IncludeOffset))
IncludeOffset = PrevEntry->IncludeOffset;
}
Entries.push_back(LineEntry::get(Offset, LineNo, FilenameID, FileKind,
IncludeOffset));
}
/// FindNearestLineEntry - Find the line entry nearest to FID that is before
/// it. If there is no line entry before Offset in FID, return null.
const LineEntry *LineTableInfo::FindNearestLineEntry(unsigned FID,
unsigned Offset) {
const std::vector<LineEntry> &Entries = LineEntries[FID];
assert(!Entries.empty() && "No #line entries for this FID after all!");
// It is very common for the query to be after the last #line, check this
// first.
if (Entries.back().FileOffset <= Offset)
return &Entries.back();
// Do a binary search to find the maximal element that is still before Offset.
std::vector<LineEntry>::const_iterator I =
std::upper_bound(Entries.begin(), Entries.end(), Offset);
if (I == Entries.begin()) return 0;
return &*--I;
}
/// \brief Add a new line entry that has already been encoded into
/// the internal representation of the line table.
void LineTableInfo::AddEntry(unsigned FID,
const std::vector<LineEntry> &Entries) {
LineEntries[FID] = Entries;
}
/// getLineTableFilenameID - Return the uniqued ID for the specified filename.
///
unsigned SourceManager::getLineTableFilenameID(const char *Ptr, unsigned Len) {
if (LineTable == 0)
LineTable = new LineTableInfo();
return LineTable->getLineTableFilenameID(Ptr, 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 SourceManager::AddLineNote(SourceLocation Loc, unsigned LineNo,
int FilenameID) {
std::pair<FileID, unsigned> LocInfo = getDecomposedInstantiationLoc(Loc);
bool Invalid = false;
const SLocEntry &Entry = getSLocEntry(LocInfo.first, &Invalid);
if (!Entry.isFile() || Invalid)
return;
const SrcMgr::FileInfo &FileInfo = Entry.getFile();
// Remember that this file has #line directives now if it doesn't already.
const_cast<SrcMgr::FileInfo&>(FileInfo).setHasLineDirectives();
if (LineTable == 0)
LineTable = new LineTableInfo();
LineTable->AddLineNote(LocInfo.first.ID, LocInfo.second, LineNo, FilenameID);
}
/// AddLineNote - Add a GNU line marker to the line table.
void SourceManager::AddLineNote(SourceLocation Loc, unsigned LineNo,
int FilenameID, bool IsFileEntry,
bool IsFileExit, bool IsSystemHeader,
bool IsExternCHeader) {
// If there is no filename and no flags, this is treated just like a #line,
// which does not change the flags of the previous line marker.
if (FilenameID == -1) {
assert(!IsFileEntry && !IsFileExit && !IsSystemHeader && !IsExternCHeader &&
"Can't set flags without setting the filename!");
return AddLineNote(Loc, LineNo, FilenameID);
}
std::pair<FileID, unsigned> LocInfo = getDecomposedInstantiationLoc(Loc);
bool Invalid = false;
const SLocEntry &Entry = getSLocEntry(LocInfo.first, &Invalid);
if (!Entry.isFile() || Invalid)
return;
const SrcMgr::FileInfo &FileInfo = Entry.getFile();
// Remember that this file has #line directives now if it doesn't already.
const_cast<SrcMgr::FileInfo&>(FileInfo).setHasLineDirectives();
if (LineTable == 0)
LineTable = new LineTableInfo();
SrcMgr::CharacteristicKind FileKind;
if (IsExternCHeader)
FileKind = SrcMgr::C_ExternCSystem;
else if (IsSystemHeader)
FileKind = SrcMgr::C_System;
else
FileKind = SrcMgr::C_User;
unsigned EntryExit = 0;
if (IsFileEntry)
EntryExit = 1;
else if (IsFileExit)
EntryExit = 2;
LineTable->AddLineNote(LocInfo.first.ID, LocInfo.second, LineNo, FilenameID,
EntryExit, FileKind);
}
LineTableInfo &SourceManager::getLineTable() {
if (LineTable == 0)
LineTable = new LineTableInfo();
return *LineTable;
}
//===----------------------------------------------------------------------===//
// Private 'Create' methods.
//===----------------------------------------------------------------------===//
SourceManager::SourceManager(Diagnostic &Diag, FileManager &FileMgr)
: Diag(Diag), FileMgr(FileMgr), OverridenFilesKeepOriginalName(true),
ExternalSLocEntries(0), LineTable(0), NumLinearScans(0),
NumBinaryProbes(0), FakeBufferForRecovery(0) {
clearIDTables();
Diag.setSourceManager(this);
}
SourceManager::~SourceManager() {
delete LineTable;
// Delete FileEntry objects corresponding to content caches. Since the actual
// content cache objects are bump pointer allocated, we just have to run the
// dtors, but we call the deallocate method for completeness.
for (unsigned i = 0, e = MemBufferInfos.size(); i != e; ++i) {
MemBufferInfos[i]->~ContentCache();
ContentCacheAlloc.Deallocate(MemBufferInfos[i]);
}
for (llvm::DenseMap<const FileEntry*, SrcMgr::ContentCache*>::iterator
I = FileInfos.begin(), E = FileInfos.end(); I != E; ++I) {
I->second->~ContentCache();
ContentCacheAlloc.Deallocate(I->second);
}
delete FakeBufferForRecovery;
}
void SourceManager::clearIDTables() {
MainFileID = FileID();
SLocEntryTable.clear();
LastLineNoFileIDQuery = FileID();
LastLineNoContentCache = 0;
LastFileIDLookup = FileID();
if (LineTable)
LineTable->clear();
// Use up FileID #0 as an invalid instantiation.
NextOffset = 0;
createInstantiationLoc(SourceLocation(),SourceLocation(),SourceLocation(), 1);
}
/// getOrCreateContentCache - Create or return a cached ContentCache for the
/// specified file.
const ContentCache *
SourceManager::getOrCreateContentCache(const FileEntry *FileEnt) {
assert(FileEnt && "Didn't specify a file entry to use?");
// Do we already have information about this file?
ContentCache *&Entry = FileInfos[FileEnt];
if (Entry) return Entry;
// Nope, create a new Cache entry. Make sure it is at least 8-byte aligned
// so that FileInfo can use the low 3 bits of the pointer for its own
// nefarious purposes.
unsigned EntryAlign = llvm::AlignOf<ContentCache>::Alignment;
EntryAlign = std::max(8U, EntryAlign);
Entry = ContentCacheAlloc.Allocate<ContentCache>(1, EntryAlign);
// If the file contents are overridden with contents from another file,
// pass that file to ContentCache.
llvm::DenseMap<const FileEntry *, const FileEntry *>::iterator
overI = OverriddenFiles.find(FileEnt);
if (overI == OverriddenFiles.end())
new (Entry) ContentCache(FileEnt);
else
new (Entry) ContentCache(OverridenFilesKeepOriginalName ? FileEnt
: overI->second,
overI->second);
return Entry;
}
/// createMemBufferContentCache - Create a new ContentCache for the specified
/// memory buffer. This does no caching.
const ContentCache*
SourceManager::createMemBufferContentCache(const MemoryBuffer *Buffer) {
// Add a new ContentCache to the MemBufferInfos list and return it. Make sure
// it is at least 8-byte aligned so that FileInfo can use the low 3 bits of
// the pointer for its own nefarious purposes.
unsigned EntryAlign = llvm::AlignOf<ContentCache>::Alignment;
EntryAlign = std::max(8U, EntryAlign);
ContentCache *Entry = ContentCacheAlloc.Allocate<ContentCache>(1, EntryAlign);
new (Entry) ContentCache();
MemBufferInfos.push_back(Entry);
Entry->setBuffer(Buffer);
return Entry;
}
void SourceManager::PreallocateSLocEntries(ExternalSLocEntrySource *Source,
unsigned NumSLocEntries,
unsigned NextOffset) {
ExternalSLocEntries = Source;
this->NextOffset = NextOffset;
unsigned CurPrealloc = SLocEntryLoaded.size();
// If we've ever preallocated, we must not count the dummy entry.
if (CurPrealloc) --CurPrealloc;
SLocEntryLoaded.resize(NumSLocEntries + 1);
SLocEntryLoaded[0] = true;
SLocEntryTable.resize(SLocEntryTable.size() + NumSLocEntries - CurPrealloc);
}
void SourceManager::ClearPreallocatedSLocEntries() {
unsigned I = 0;
for (unsigned N = SLocEntryLoaded.size(); I != N; ++I)
if (!SLocEntryLoaded[I])
break;
// We've already loaded all preallocated source location entries.
if (I == SLocEntryLoaded.size())
return;
// Remove everything from location I onward.
SLocEntryTable.resize(I);
SLocEntryLoaded.clear();
ExternalSLocEntries = 0;
}
/// \brief As part of recovering from missing or changed content, produce a
/// fake, non-empty buffer.
const llvm::MemoryBuffer *SourceManager::getFakeBufferForRecovery() const {
if (!FakeBufferForRecovery)
FakeBufferForRecovery
= llvm::MemoryBuffer::getMemBuffer("<<<INVALID BUFFER>>");
return FakeBufferForRecovery;
}
//===----------------------------------------------------------------------===//
// Methods to create new FileID's and instantiations.
//===----------------------------------------------------------------------===//
/// 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 SourceManager::createFileID(const ContentCache *File,
SourceLocation IncludePos,
SrcMgr::CharacteristicKind FileCharacter,
unsigned PreallocatedID,
unsigned Offset) {
if (PreallocatedID) {
// If we're filling in a preallocated ID, just load in the file
// entry and return.
assert(PreallocatedID < SLocEntryLoaded.size() &&
"Preallocate ID out-of-range");
assert(!SLocEntryLoaded[PreallocatedID] &&
"Source location entry already loaded");
assert(Offset && "Preallocate source location cannot have zero offset");
SLocEntryTable[PreallocatedID]
= SLocEntry::get(Offset, FileInfo::get(IncludePos, File, FileCharacter));
SLocEntryLoaded[PreallocatedID] = true;
FileID FID = FileID::get(PreallocatedID);
return FID;
}
SLocEntryTable.push_back(SLocEntry::get(NextOffset,
FileInfo::get(IncludePos, File,
FileCharacter)));
unsigned FileSize = File->getSize();
assert(NextOffset+FileSize+1 > NextOffset && "Ran out of source locations!");
NextOffset += FileSize+1;
// Set LastFileIDLookup to the newly created file. The next getFileID call is
// almost guaranteed to be from that file.
FileID FID = FileID::get(SLocEntryTable.size()-1);
return LastFileIDLookup = FID;
}
/// createInstantiationLoc - Return a new SourceLocation that encodes the fact
/// that a token from SpellingLoc should actually be referenced from
/// InstantiationLoc.
SourceLocation SourceManager::createInstantiationLoc(SourceLocation SpellingLoc,
SourceLocation ILocStart,
SourceLocation ILocEnd,
unsigned TokLength,
unsigned PreallocatedID,
unsigned Offset) {
InstantiationInfo II = InstantiationInfo::get(ILocStart,ILocEnd, SpellingLoc);
if (PreallocatedID) {
// If we're filling in a preallocated ID, just load in the
// instantiation entry and return.
assert(PreallocatedID < SLocEntryLoaded.size() &&
"Preallocate ID out-of-range");
assert(!SLocEntryLoaded[PreallocatedID] &&
"Source location entry already loaded");
assert(Offset && "Preallocate source location cannot have zero offset");
SLocEntryTable[PreallocatedID] = SLocEntry::get(Offset, II);
SLocEntryLoaded[PreallocatedID] = true;
return SourceLocation::getMacroLoc(Offset);
}
SLocEntryTable.push_back(SLocEntry::get(NextOffset, II));
assert(NextOffset+TokLength+1 > NextOffset && "Ran out of source locations!");
NextOffset += TokLength+1;
return SourceLocation::getMacroLoc(NextOffset-(TokLength+1));
}
const llvm::MemoryBuffer *
SourceManager::getMemoryBufferForFile(const FileEntry *File,
bool *Invalid) {
const SrcMgr::ContentCache *IR = getOrCreateContentCache(File);
assert(IR && "getOrCreateContentCache() cannot return NULL");
return IR->getBuffer(Diag, *this, SourceLocation(), Invalid);
}
void SourceManager::overrideFileContents(const FileEntry *SourceFile,
const llvm::MemoryBuffer *Buffer,
bool DoNotFree) {
const SrcMgr::ContentCache *IR = getOrCreateContentCache(SourceFile);
assert(IR && "getOrCreateContentCache() cannot return NULL");
const_cast<SrcMgr::ContentCache *>(IR)->replaceBuffer(Buffer, DoNotFree);
}
void SourceManager::overrideFileContents(const FileEntry *SourceFile,
const FileEntry *NewFile) {
assert(SourceFile->getSize() == NewFile->getSize() &&
"Different sizes, use the FileManager to create a virtual file with "
"the correct size");
assert(FileInfos.count(SourceFile) == 0 &&
"This function should be called at the initialization stage, before "
"any parsing occurs.");
OverriddenFiles[SourceFile] = NewFile;
}
llvm::StringRef SourceManager::getBufferData(FileID FID, bool *Invalid) const {
bool MyInvalid = false;
const SLocEntry &SLoc = getSLocEntry(FID.ID, &MyInvalid);
if (!SLoc.isFile() || MyInvalid) {
if (Invalid)
*Invalid = true;
return "<<<<<INVALID SOURCE LOCATION>>>>>";
}
const llvm::MemoryBuffer *Buf
= SLoc.getFile().getContentCache()->getBuffer(Diag, *this, SourceLocation(),
&MyInvalid);
if (Invalid)
*Invalid = MyInvalid;
if (MyInvalid)
return "<<<<<INVALID SOURCE LOCATION>>>>>";
return Buf->getBuffer();
}
//===----------------------------------------------------------------------===//
// SourceLocation manipulation methods.
//===----------------------------------------------------------------------===//
/// getFileIDSlow - 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 SourceManager::getFileIDSlow(unsigned SLocOffset) const {
if (!SLocOffset)
return FileID::get(0);
// After the first and second level caches, I see two common sorts of
// behavior: 1) a lot of searched FileID's are "near" the cached file location
// or are "near" the cached instantiation location. 2) others are just
// completely random and may be a very long way away.
//
// To handle this, we do a linear search for up to 8 steps to catch #1 quickly
// then we fall back to a less cache efficient, but more scalable, binary
// search to find the location.
// See if this is near the file point - worst case we start scanning from the
// most newly created FileID.
std::vector<SrcMgr::SLocEntry>::const_iterator I;
if (SLocEntryTable[LastFileIDLookup.ID].getOffset() < SLocOffset) {
// Neither loc prunes our search.
I = SLocEntryTable.end();
} else {
// Perhaps it is near the file point.
I = SLocEntryTable.begin()+LastFileIDLookup.ID;
}
// Find the FileID that contains this. "I" is an iterator that points to a
// FileID whose offset is known to be larger than SLocOffset.
unsigned NumProbes = 0;
while (1) {
--I;
if (ExternalSLocEntries) {
bool Invalid = false;
getSLocEntry(FileID::get(I - SLocEntryTable.begin()), &Invalid);
if (Invalid)
return FileID::get(0);
}
if (I->getOffset() <= SLocOffset) {
#if 0
printf("lin %d -> %d [%s] %d %d\n", SLocOffset,
I-SLocEntryTable.begin(),
I->isInstantiation() ? "inst" : "file",
LastFileIDLookup.ID, int(SLocEntryTable.end()-I));
#endif
FileID Res = FileID::get(I-SLocEntryTable.begin());
// If this isn't an instantiation, remember it. We have good locality
// across FileID lookups.
if (!I->isInstantiation())
LastFileIDLookup = Res;
NumLinearScans += NumProbes+1;
return Res;
}
if (++NumProbes == 8)
break;
}
// Convert "I" back into an index. We know that it is an entry whose index is
// larger than the offset we are looking for.
unsigned GreaterIndex = I-SLocEntryTable.begin();
// LessIndex - This is the lower bound of the range that we're searching.
// We know that the offset corresponding to the FileID is is less than
// SLocOffset.
unsigned LessIndex = 0;
NumProbes = 0;
while (1) {
bool Invalid = false;
unsigned MiddleIndex = (GreaterIndex-LessIndex)/2+LessIndex;
unsigned MidOffset = getSLocEntry(FileID::get(MiddleIndex), &Invalid)
.getOffset();
if (Invalid)
return FileID::get(0);
++NumProbes;
// If the offset of the midpoint is too large, chop the high side of the
// range to the midpoint.
if (MidOffset > SLocOffset) {
GreaterIndex = MiddleIndex;
continue;
}
// If the middle index contains the value, succeed and return.
if (isOffsetInFileID(FileID::get(MiddleIndex), SLocOffset)) {
#if 0
printf("bin %d -> %d [%s] %d %d\n", SLocOffset,
I-SLocEntryTable.begin(),
I->isInstantiation() ? "inst" : "file",
LastFileIDLookup.ID, int(SLocEntryTable.end()-I));
#endif
FileID Res = FileID::get(MiddleIndex);
// If this isn't an instantiation, remember it. We have good locality
// across FileID lookups.
if (!I->isInstantiation())
LastFileIDLookup = Res;
NumBinaryProbes += NumProbes;
return Res;
}
// Otherwise, move the low-side up to the middle index.
LessIndex = MiddleIndex;
}
}
SourceLocation SourceManager::
getInstantiationLocSlowCase(SourceLocation Loc) const {
do {
// Note: If Loc indicates an offset into a token that came from a macro
// expansion (e.g. the 5th character of the token) we do not want to add
// this offset when going to the instantiation location. The instatiation
// location is the macro invocation, which the offset has nothing to do
// with. This is unlike when we get the spelling loc, because the offset
// directly correspond to the token whose spelling we're inspecting.
Loc = getSLocEntry(getFileID(Loc)).getInstantiation()
.getInstantiationLocStart();
} while (!Loc.isFileID());
return Loc;
}
SourceLocation SourceManager::getSpellingLocSlowCase(SourceLocation Loc) const {
do {
std::pair<FileID, unsigned> LocInfo = getDecomposedLoc(Loc);
Loc = getSLocEntry(LocInfo.first).getInstantiation().getSpellingLoc();
Loc = Loc.getFileLocWithOffset(LocInfo.second);
} while (!Loc.isFileID());
return Loc;
}
std::pair<FileID, unsigned>
SourceManager::getDecomposedInstantiationLocSlowCase(const SrcMgr::SLocEntry *E,
unsigned Offset) const {
// If this is an instantiation record, walk through all the instantiation
// points.
FileID FID;
SourceLocation Loc;
do {
Loc = E->getInstantiation().getInstantiationLocStart();
FID = getFileID(Loc);
E = &getSLocEntry(FID);
Offset += Loc.getOffset()-E->getOffset();
} while (!Loc.isFileID());
return std::make_pair(FID, Offset);
}
std::pair<FileID, unsigned>
SourceManager::getDecomposedSpellingLocSlowCase(const SrcMgr::SLocEntry *E,
unsigned Offset) const {
// If this is an instantiation record, walk through all the instantiation
// points.
FileID FID;
SourceLocation Loc;
do {
Loc = E->getInstantiation().getSpellingLoc();
FID = getFileID(Loc);
E = &getSLocEntry(FID);
Offset += Loc.getOffset()-E->getOffset();
} while (!Loc.isFileID());
return std::make_pair(FID, Offset);
}
/// 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 SourceManager::getImmediateSpellingLoc(SourceLocation Loc) const{
if (Loc.isFileID()) return Loc;
std::pair<FileID, unsigned> LocInfo = getDecomposedLoc(Loc);
Loc = getSLocEntry(LocInfo.first).getInstantiation().getSpellingLoc();
return Loc.getFileLocWithOffset(LocInfo.second);
}
/// getImmediateInstantiationRange - Loc is required to be an instantiation
/// location. Return the start/end of the instantiation information.
std::pair<SourceLocation,SourceLocation>
SourceManager::getImmediateInstantiationRange(SourceLocation Loc) const {
assert(Loc.isMacroID() && "Not an instantiation loc!");
const InstantiationInfo &II = getSLocEntry(getFileID(Loc)).getInstantiation();
return II.getInstantiationLocRange();
}
/// getInstantiationRange - Given a SourceLocation object, return the
/// range of tokens covered by the instantiation in the ultimate file.
std::pair<SourceLocation,SourceLocation>
SourceManager::getInstantiationRange(SourceLocation Loc) const {
if (Loc.isFileID()) return std::make_pair(Loc, Loc);
std::pair<SourceLocation,SourceLocation> Res =
getImmediateInstantiationRange(Loc);
// Fully resolve the start and end locations to their ultimate instantiation
// points.
while (!Res.first.isFileID())
Res.first = getImmediateInstantiationRange(Res.first).first;
while (!Res.second.isFileID())
Res.second = getImmediateInstantiationRange(Res.second).second;
return Res;
}
//===----------------------------------------------------------------------===//
// Queries about the code at a SourceLocation.
//===----------------------------------------------------------------------===//
/// getCharacterData - Return a pointer to the start of the specified location
/// in the appropriate MemoryBuffer.
const char *SourceManager::getCharacterData(SourceLocation SL,
bool *Invalid) const {
// Note that this is a hot function in the getSpelling() path, which is
// heavily used by -E mode.
std::pair<FileID, unsigned> LocInfo = getDecomposedSpellingLoc(SL);
// Note that calling 'getBuffer()' may lazily page in a source file.
bool CharDataInvalid = false;
const SLocEntry &Entry = getSLocEntry(LocInfo.first, &CharDataInvalid);
if (CharDataInvalid || !Entry.isFile()) {
if (Invalid)
*Invalid = true;
return "<<<<INVALID BUFFER>>>>";
}
const llvm::MemoryBuffer *Buffer
= Entry.getFile().getContentCache()
->getBuffer(Diag, *this, SourceLocation(), &CharDataInvalid);
if (Invalid)
*Invalid = CharDataInvalid;
return Buffer->getBufferStart() + (CharDataInvalid? 0 : LocInfo.second);
}
/// getColumnNumber - Return the column # for the specified file position.
/// this is significantly cheaper to compute than the line number.
unsigned SourceManager::getColumnNumber(FileID FID, unsigned FilePos,
bool *Invalid) const {
bool MyInvalid = false;
const char *Buf = getBuffer(FID, &MyInvalid)->getBufferStart();
if (Invalid)
*Invalid = MyInvalid;
if (MyInvalid)
return 1;
unsigned LineStart = FilePos;
while (LineStart && Buf[LineStart-1] != '\n' && Buf[LineStart-1] != '\r')
--LineStart;
return FilePos-LineStart+1;
}
// isInvalid - Return the result of calling loc.isInvalid(), and
// if Invalid is not null, set its value to same.
static bool isInvalid(SourceLocation Loc, bool *Invalid) {
bool MyInvalid = Loc.isInvalid();
if (Invalid)
*Invalid = MyInvalid;
return MyInvalid;
}
unsigned SourceManager::getSpellingColumnNumber(SourceLocation Loc,
bool *Invalid) const {
if (isInvalid(Loc, Invalid)) return 0;
std::pair<FileID, unsigned> LocInfo = getDecomposedSpellingLoc(Loc);
return getColumnNumber(LocInfo.first, LocInfo.second, Invalid);
}
unsigned SourceManager::getInstantiationColumnNumber(SourceLocation Loc,
bool *Invalid) const {
if (isInvalid(Loc, Invalid)) return 0;
std::pair<FileID, unsigned> LocInfo = getDecomposedInstantiationLoc(Loc);
return getColumnNumber(LocInfo.first, LocInfo.second, Invalid);
}
unsigned SourceManager::getPresumedColumnNumber(SourceLocation Loc,
bool *Invalid) const {
if (isInvalid(Loc, Invalid)) return 0;
return getPresumedLoc(Loc).getColumn();
}
static LLVM_ATTRIBUTE_NOINLINE void
ComputeLineNumbers(Diagnostic &Diag, ContentCache *FI,
llvm::BumpPtrAllocator &Alloc,
const SourceManager &SM, bool &Invalid);
static void ComputeLineNumbers(Diagnostic &Diag, ContentCache *FI,
llvm::BumpPtrAllocator &Alloc,
const SourceManager &SM, bool &Invalid) {
// Note that calling 'getBuffer()' may lazily page in the file.
const MemoryBuffer *Buffer = FI->getBuffer(Diag, SM, SourceLocation(),
&Invalid);
if (Invalid)
return;
// Find the file offsets of all of the *physical* source lines. This does
// not look at trigraphs, escaped newlines, or anything else tricky.
std::vector<unsigned> LineOffsets;
// Line #1 starts at char 0.
LineOffsets.push_back(0);
const unsigned char *Buf = (const unsigned char *)Buffer->getBufferStart();
const unsigned char *End = (const unsigned char *)Buffer->getBufferEnd();
unsigned Offs = 0;
while (1) {
// Skip over the contents of the line.
// TODO: Vectorize this? This is very performance sensitive for programs
// with lots of diagnostics and in -E mode.
const unsigned char *NextBuf = (const unsigned char *)Buf;
while (*NextBuf != '\n' && *NextBuf != '\r' && *NextBuf != '\0')
++NextBuf;
Offs += NextBuf-Buf;
Buf = NextBuf;
if (Buf[0] == '\n' || Buf[0] == '\r') {
// If this is \n\r or \r\n, skip both characters.
if ((Buf[1] == '\n' || Buf[1] == '\r') && Buf[0] != Buf[1])
++Offs, ++Buf;
++Offs, ++Buf;
LineOffsets.push_back(Offs);
} else {
// Otherwise, this is a null. If end of file, exit.
if (Buf == End) break;
// Otherwise, skip the null.
++Offs, ++Buf;
}
}
// Copy the offsets into the FileInfo structure.
FI->NumLines = LineOffsets.size();
FI->SourceLineCache = Alloc.Allocate<unsigned>(LineOffsets.size());
std::copy(LineOffsets.begin(), LineOffsets.end(), FI->SourceLineCache);
}
/// 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 SourceManager::getLineNumber(FileID FID, unsigned FilePos,
bool *Invalid) const {
ContentCache *Content;
if (LastLineNoFileIDQuery == FID)
Content = LastLineNoContentCache;
else {
bool MyInvalid = false;
const SLocEntry &Entry = getSLocEntry(FID, &MyInvalid);
if (MyInvalid || !Entry.isFile()) {
if (Invalid)
*Invalid = true;
return 1;
}
Content = const_cast<ContentCache*>(Entry.getFile().getContentCache());
}
// If this is the first use of line information for this buffer, compute the
/// SourceLineCache for it on demand.
if (Content->SourceLineCache == 0) {
bool MyInvalid = false;
ComputeLineNumbers(Diag, Content, ContentCacheAlloc, *this, MyInvalid);
if (Invalid)
*Invalid = MyInvalid;
if (MyInvalid)
return 1;
} else if (Invalid)
*Invalid = false;
// Okay, we know we have a line number table. Do a binary search to find the
// line number that this character position lands on.
unsigned *SourceLineCache = Content->SourceLineCache;
unsigned *SourceLineCacheStart = SourceLineCache;
unsigned *SourceLineCacheEnd = SourceLineCache + Content->NumLines;
unsigned QueriedFilePos = FilePos+1;
// FIXME: I would like to be convinced that this code is worth being as
// complicated as it is, binary search isn't that slow.
//
// If it is worth being optimized, then in my opinion it could be more
// performant, simpler, and more obviously correct by just "galloping" outward
// from the queried file position. In fact, this could be incorporated into a
// generic algorithm such as lower_bound_with_hint.
//
// If someone gives me a test case where this matters, and I will do it! - DWD
// If the previous query was to the same file, we know both the file pos from
// that query and the line number returned. This allows us to narrow the
// search space from the entire file to something near the match.
if (LastLineNoFileIDQuery == FID) {
if (QueriedFilePos >= LastLineNoFilePos) {
// FIXME: Potential overflow?
SourceLineCache = SourceLineCache+LastLineNoResult-1;
// The query is likely to be nearby the previous one. Here we check to
// see if it is within 5, 10 or 20 lines. It can be far away in cases
// where big comment blocks and vertical whitespace eat up lines but
// contribute no tokens.
if (SourceLineCache+5 < SourceLineCacheEnd) {
if (SourceLineCache[5] > QueriedFilePos)
SourceLineCacheEnd = SourceLineCache+5;
else if (SourceLineCache+10 < SourceLineCacheEnd) {
if (SourceLineCache[10] > QueriedFilePos)
SourceLineCacheEnd = SourceLineCache+10;
else if (SourceLineCache+20 < SourceLineCacheEnd) {
if (SourceLineCache[20] > QueriedFilePos)
SourceLineCacheEnd = SourceLineCache+20;
}
}
}
} else {
if (LastLineNoResult < Content->NumLines)
SourceLineCacheEnd = SourceLineCache+LastLineNoResult+1;
}
}
// If the spread is large, do a "radix" test as our initial guess, based on
// the assumption that lines average to approximately the same length.
// NOTE: This is currently disabled, as it does not appear to be profitable in
// initial measurements.
if (0 && SourceLineCacheEnd-SourceLineCache > 20) {
unsigned FileLen = Content->SourceLineCache[Content->NumLines-1];
// Take a stab at guessing where it is.
unsigned ApproxPos = Content->NumLines*QueriedFilePos / FileLen;
// Check for -10 and +10 lines.
unsigned LowerBound = std::max(int(ApproxPos-10), 0);
unsigned UpperBound = std::min(ApproxPos+10, FileLen);
// If the computed lower bound is less than the query location, move it in.
if (SourceLineCache < SourceLineCacheStart+LowerBound &&
SourceLineCacheStart[LowerBound] < QueriedFilePos)
SourceLineCache = SourceLineCacheStart+LowerBound;
// If the computed upper bound is greater than the query location, move it.
if (SourceLineCacheEnd > SourceLineCacheStart+UpperBound &&
SourceLineCacheStart[UpperBound] >= QueriedFilePos)
SourceLineCacheEnd = SourceLineCacheStart+UpperBound;
}
unsigned *Pos
= std::lower_bound(SourceLineCache, SourceLineCacheEnd, QueriedFilePos);
unsigned LineNo = Pos-SourceLineCacheStart;
LastLineNoFileIDQuery = FID;
LastLineNoContentCache = Content;
LastLineNoFilePos = QueriedFilePos;
LastLineNoResult = LineNo;
return LineNo;
}
unsigned SourceManager::getSpellingLineNumber(SourceLocation Loc,
bool *Invalid) const {
if (isInvalid(Loc, Invalid)) return 0;
std::pair<FileID, unsigned> LocInfo = getDecomposedSpellingLoc(Loc);
return getLineNumber(LocInfo.first, LocInfo.second);
}
unsigned SourceManager::getInstantiationLineNumber(SourceLocation Loc,
bool *Invalid) const {
if (isInvalid(Loc, Invalid)) return 0;
std::pair<FileID, unsigned> LocInfo = getDecomposedInstantiationLoc(Loc);
return getLineNumber(LocInfo.first, LocInfo.second);
}
unsigned SourceManager::getPresumedLineNumber(SourceLocation Loc,
bool *Invalid) const {
if (isInvalid(Loc, Invalid)) return 0;
return getPresumedLoc(Loc).getLine();
}
/// 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
SourceManager::getFileCharacteristic(SourceLocation Loc) const {
assert(!Loc.isInvalid() && "Can't get file characteristic of invalid loc!");
std::pair<FileID, unsigned> LocInfo = getDecomposedInstantiationLoc(Loc);
bool Invalid = false;
const SLocEntry &SEntry = getSLocEntry(LocInfo.first, &Invalid);
if (Invalid || !SEntry.isFile())
return C_User;
const SrcMgr::FileInfo &FI = SEntry.getFile();
// If there are no #line directives in this file, just return the whole-file
// state.
if (!FI.hasLineDirectives())
return FI.getFileCharacteristic();
assert(LineTable && "Can't have linetable entries without a LineTable!");
// See if there is a #line directive before the location.
const LineEntry *Entry =
LineTable->FindNearestLineEntry(LocInfo.first.ID, LocInfo.second);
// If this is before the first line marker, use the file characteristic.
if (!Entry)
return FI.getFileCharacteristic();
return Entry->FileKind;
}
/// 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 *SourceManager::getBufferName(SourceLocation Loc,
bool *Invalid) const {
if (isInvalid(Loc, Invalid)) return "<invalid loc>";
return getBuffer(getFileID(Loc), Invalid)->getBufferIdentifier();
}
/// 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 SourceManager::getPresumedLoc(SourceLocation Loc) const {
if (Loc.isInvalid()) return PresumedLoc();
// Presumed locations are always for instantiation points.
std::pair<FileID, unsigned> LocInfo = getDecomposedInstantiationLoc(Loc);
bool Invalid = false;
const SLocEntry &Entry = getSLocEntry(LocInfo.first, &Invalid);
if (Invalid || !Entry.isFile())
return PresumedLoc();
const SrcMgr::FileInfo &FI = Entry.getFile();
const SrcMgr::ContentCache *C = FI.getContentCache();
// To get the source name, first consult the FileEntry (if one exists)
// before the MemBuffer as this will avoid unnecessarily paging in the
// MemBuffer.
const char *Filename;
if (C->OrigEntry)
Filename = C->OrigEntry->getName();
else
Filename = C->getBuffer(Diag, *this)->getBufferIdentifier();
unsigned LineNo = getLineNumber(LocInfo.first, LocInfo.second, &Invalid);
if (Invalid)
return PresumedLoc();
unsigned ColNo = getColumnNumber(LocInfo.first, LocInfo.second, &Invalid);
if (Invalid)
return PresumedLoc();
SourceLocation IncludeLoc = FI.getIncludeLoc();
// If we have #line directives in this file, update and overwrite the physical
// location info if appropriate.
if (FI.hasLineDirectives()) {
assert(LineTable && "Can't have linetable entries without a LineTable!");
// See if there is a #line directive before this. If so, get it.
if (const LineEntry *Entry =
LineTable->FindNearestLineEntry(LocInfo.first.ID, LocInfo.second)) {
// If the LineEntry indicates a filename, use it.
if (Entry->FilenameID != -1)
Filename = LineTable->getFilename(Entry->FilenameID);
// Use the line number specified by the LineEntry. This line number may
// be multiple lines down from the line entry. Add the difference in
// physical line numbers from the query point and the line marker to the
// total.
unsigned MarkerLineNo = getLineNumber(LocInfo.first, Entry->FileOffset);
LineNo = Entry->LineNo + (LineNo-MarkerLineNo-1);
// Note that column numbers are not molested by line markers.
// Handle virtual #include manipulation.
if (Entry->IncludeOffset) {
IncludeLoc = getLocForStartOfFile(LocInfo.first);
IncludeLoc = IncludeLoc.getFileLocWithOffset(Entry->IncludeOffset);
}
}
}
return PresumedLoc(Filename, LineNo, ColNo, IncludeLoc);
}
//===----------------------------------------------------------------------===//
// Other miscellaneous methods.
//===----------------------------------------------------------------------===//
/// \brief Retrieve the inode for the given file entry, if possible.
///
/// This routine involves a system call, and therefore should only be used
/// in non-performance-critical code.
static llvm::Optional<ino_t> getActualFileInode(const FileEntry *File) {
if (!File)
return llvm::Optional<ino_t>();
struct stat StatBuf;
if (::stat(File->getName(), &StatBuf))
return llvm::Optional<ino_t>();
return StatBuf.st_ino;
}
/// \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 SourceManager::getLocation(const FileEntry *SourceFile,
unsigned Line, unsigned Col) {
assert(SourceFile && "Null source file!");
assert(Line && Col && "Line and column should start from 1!");
// Find the first file ID that corresponds to the given file.
FileID FirstFID;
// First, check the main file ID, since it is common to look for a
// location in the main file.
llvm::Optional<ino_t> SourceFileInode;
llvm::Optional<llvm::StringRef> SourceFileName;
if (!MainFileID.isInvalid()) {
bool Invalid = false;
const SLocEntry &MainSLoc = getSLocEntry(MainFileID, &Invalid);
if (Invalid)
return SourceLocation();
if (MainSLoc.isFile()) {
const ContentCache *MainContentCache
= MainSLoc.getFile().getContentCache();
if (!MainContentCache) {
// Can't do anything
} else if (MainContentCache->OrigEntry == SourceFile) {
FirstFID = MainFileID;
} else {
// Fall back: check whether we have the same base name and inode
// as the main file.
const FileEntry *MainFile = MainContentCache->OrigEntry;
SourceFileName = llvm::sys::path::filename(SourceFile->getName());
if (*SourceFileName == llvm::sys::path::filename(MainFile->getName())) {
SourceFileInode = getActualFileInode(SourceFile);
if (SourceFileInode) {
if (llvm::Optional<ino_t> MainFileInode
= getActualFileInode(MainFile)) {
if (*SourceFileInode == *MainFileInode) {
FirstFID = MainFileID;
SourceFile = MainFile;
}
}
}
}
}
}
}
if (FirstFID.isInvalid()) {
// The location we're looking for isn't in the main file; look
// through all of the source locations.
for (unsigned I = 0, N = sloc_entry_size(); I != N; ++I) {
bool Invalid = false;
const SLocEntry &SLoc = getSLocEntry(I, &Invalid);
if (Invalid)
return SourceLocation();
if (SLoc.isFile() &&
SLoc.getFile().getContentCache() &&
SLoc.getFile().getContentCache()->OrigEntry == SourceFile) {
FirstFID = FileID::get(I);
break;
}
}
}
// If we haven't found what we want yet, try again, but this time stat()
// each of the files in case the files have changed since we originally
// parsed the file.
if (FirstFID.isInvalid() &&
(SourceFileName ||
(SourceFileName = llvm::sys::path::filename(SourceFile->getName()))) &&
(SourceFileInode ||
(SourceFileInode = getActualFileInode(SourceFile)))) {
bool Invalid = false;
for (unsigned I = 0, N = sloc_entry_size(); I != N; ++I) {
const SLocEntry &SLoc = getSLocEntry(I, &Invalid);
if (Invalid)
return SourceLocation();
if (SLoc.isFile()) {
const ContentCache *FileContentCache
= SLoc.getFile().getContentCache();
const FileEntry *Entry =FileContentCache? FileContentCache->OrigEntry : 0;
if (Entry &&
*SourceFileName == llvm::sys::path::filename(Entry->getName())) {
if (llvm::Optional<ino_t> EntryInode = getActualFileInode(Entry)) {
if (*SourceFileInode == *EntryInode) {
FirstFID = FileID::get(I);
SourceFile = Entry;
break;
}
}
}
}
}
}
if (FirstFID.isInvalid())
return SourceLocation();
if (Line == 1 && Col == 1)
return getLocForStartOfFile(FirstFID);
ContentCache *Content
= const_cast<ContentCache *>(getOrCreateContentCache(SourceFile));
if (!Content)
return SourceLocation();
// If this is the first use of line information for this buffer, compute the
/// SourceLineCache for it on demand.
if (Content->SourceLineCache == 0) {
bool MyInvalid = false;
ComputeLineNumbers(Diag, Content, ContentCacheAlloc, *this, MyInvalid);
if (MyInvalid)
return SourceLocation();
}
if (Line > Content->NumLines) {
unsigned Size = Content->getBuffer(Diag, *this)->getBufferSize();
if (Size > 0)
--Size;
return getLocForStartOfFile(FirstFID).getFileLocWithOffset(Size);
}
unsigned FilePos = Content->SourceLineCache[Line - 1];
const char *Buf = Content->getBuffer(Diag, *this)->getBufferStart() + FilePos;
unsigned BufLength = Content->getBuffer(Diag, *this)->getBufferEnd() - Buf;
unsigned i = 0;
// Check that the given column is valid.
while (i < BufLength-1 && i < Col-1 && Buf[i] != '\n' && Buf[i] != '\r')
++i;
if (i < Col-1)
return getLocForStartOfFile(FirstFID).getFileLocWithOffset(FilePos + i);
return getLocForStartOfFile(FirstFID).getFileLocWithOffset(FilePos + Col - 1);
}
/// Given a decomposed source location, move it up the include/instantiation
/// stack to the parent source location. If this is possible, return the
/// decomposed version of the parent in Loc and return false. If Loc is the
/// top-level entry, return true and don't modify it.
static bool MoveUpIncludeHierarchy(std::pair<FileID, unsigned> &Loc,
const SourceManager &SM) {
SourceLocation UpperLoc;
const SrcMgr::SLocEntry &Entry = SM.getSLocEntry(Loc.first);
if (Entry.isInstantiation())
UpperLoc = Entry.getInstantiation().getInstantiationLocStart();
else
UpperLoc = Entry.getFile().getIncludeLoc();
if (UpperLoc.isInvalid())
return true; // We reached the top.
Loc = SM.getDecomposedLoc(UpperLoc);
return false;
}
/// \brief Determines the order of 2 source locations in the translation unit.
///
/// \returns true if LHS source location comes before RHS, false otherwise.
bool SourceManager::isBeforeInTranslationUnit(SourceLocation LHS,
SourceLocation RHS) const {
assert(LHS.isValid() && RHS.isValid() && "Passed invalid source location!");
if (LHS == RHS)
return false;
// If both locations are macro instantiations, the order of their offsets
// reflect the order that the tokens, pointed to by these locations, were
// instantiated (during parsing each token that is instantiated by a macro,
// expands the SLocEntries).
if (LHS.isMacroID() && RHS.isMacroID())
return LHS.getOffset() < RHS.getOffset();
std::pair<FileID, unsigned> LOffs = getDecomposedLoc(LHS);
std::pair<FileID, unsigned> ROffs = getDecomposedLoc(RHS);
// If the source locations are in the same file, just compare offsets.
if (LOffs.first == ROffs.first)
return LOffs.second < ROffs.second;
// If we are comparing a source location with multiple locations in the same
// file, we get a big win by caching the result.
if (IsBeforeInTUCache.isCacheValid(LOffs.first, ROffs.first))
return IsBeforeInTUCache.getCachedResult(LOffs.second, ROffs.second);
// Okay, we missed in the cache, start updating the cache for this query.
IsBeforeInTUCache.setQueryFIDs(LOffs.first, ROffs.first);
// "Traverse" the include/instantiation stacks of both locations and try to
// find a common "ancestor". FileIDs build a tree-like structure that
// reflects the #include hierarchy, and this algorithm needs to find the
// nearest common ancestor between the two locations. For example, if you
// have a.c that includes b.h and c.h, and are comparing a location in b.h to
// a location in c.h, we need to find that their nearest common ancestor is
// a.c, and compare the locations of the two #includes to find their relative
// ordering.
//
// SourceManager assigns FileIDs in order of parsing. This means that an
// includee always has a larger FileID than an includer. While you might
// think that we could just compare the FileID's here, that doesn't work to
// compare a point at the end of a.c with a point within c.h. Though c.h has
// a larger FileID, we have to compare the include point of c.h to the
// location in a.c.
//
// Despite not being able to directly compare FileID's, we can tell that a
// larger FileID is necessarily more deeply nested than a lower one and use
// this information to walk up the tree to the nearest common ancestor.
do {
// If LOffs is larger than ROffs, then LOffs must be more deeply nested than
// ROffs, walk up the #include chain.
if (LOffs.first.ID > ROffs.first.ID) {
if (MoveUpIncludeHierarchy(LOffs, *this))
break; // We reached the top.
} else {
// Otherwise, ROffs is larger than LOffs, so ROffs must be more deeply
// nested than LOffs, walk up the #include chain.
if (MoveUpIncludeHierarchy(ROffs, *this))
break; // We reached the top.
}
} while (LOffs.first != ROffs.first);
// If we exited because we found a nearest common ancestor, compare the
// locations within the common file and cache them.
if (LOffs.first == ROffs.first) {
IsBeforeInTUCache.setCommonLoc(LOffs.first, LOffs.second, ROffs.second);
return IsBeforeInTUCache.getCachedResult(LOffs.second, ROffs.second);
}
// There is no common ancestor, most probably because one location is in the
// predefines buffer or an AST file.
// FIXME: We should rearrange the external interface so this simply never
// happens; it can't conceptually happen. Also see PR5662.
IsBeforeInTUCache.setQueryFIDs(FileID(), FileID()); // Don't try caching.
// Zip both entries up to the top level record.
while (!MoveUpIncludeHierarchy(LOffs, *this)) /*empty*/;
while (!MoveUpIncludeHierarchy(ROffs, *this)) /*empty*/;
// If exactly one location is a memory buffer, assume it precedes the other.
// Strip off macro instantation locations, going up to the top-level File
// SLocEntry.
bool LIsMB = getFileEntryForID(LOffs.first) == 0;
bool RIsMB = getFileEntryForID(ROffs.first) == 0;
if (LIsMB != RIsMB)
return LIsMB;
// Otherwise, just assume FileIDs were created in order.
return LOffs.first < ROffs.first;
}
/// PrintStats - Print statistics to stderr.
///
void SourceManager::PrintStats() const {
llvm::errs() << "\n*** Source Manager Stats:\n";
llvm::errs() << FileInfos.size() << " files mapped, " << MemBufferInfos.size()
<< " mem buffers mapped.\n";
llvm::errs() << SLocEntryTable.size() << " SLocEntry's allocated, "
<< NextOffset << "B of Sloc address space used.\n";
unsigned NumLineNumsComputed = 0;
unsigned NumFileBytesMapped = 0;
for (fileinfo_iterator I = fileinfo_begin(), E = fileinfo_end(); I != E; ++I){
NumLineNumsComputed += I->second->SourceLineCache != 0;
NumFileBytesMapped += I->second->getSizeBytesMapped();
}
llvm::errs() << NumFileBytesMapped << " bytes of files mapped, "
<< NumLineNumsComputed << " files with line #'s computed.\n";
llvm::errs() << "FileID scans: " << NumLinearScans << " linear, "
<< NumBinaryProbes << " binary.\n";
}
ExternalSLocEntrySource::~ExternalSLocEntrySource() { }
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