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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/FileManager.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/System/Path.h"
#include <algorithm>
using namespace clang;
using namespace SrcMgr;
using llvm::MemoryBuffer;
//===----------------------------------------------------------------------===//
// SourceManager Helper Classes
//===----------------------------------------------------------------------===//
ContentCache::~ContentCache() {
delete Buffer;
}
/// 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 ? Buffer->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 ? Buffer->getBufferSize() : Entry->getSize();
}
void ContentCache::replaceBuffer(const llvm::MemoryBuffer *B) {
assert(B != Buffer);
delete Buffer;
Buffer = B;
}
const llvm::MemoryBuffer *ContentCache::getBuffer(std::string *ErrorStr) const {
// Lazily create the Buffer for ContentCaches that wrap files.
if (!Buffer && Entry) {
Buffer = MemoryBuffer::getFile(Entry->getName(), ErrorStr,Entry->getSize());
// 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) {
const llvm::StringRef FillStr("<<<MISSING SOURCE FILE>>>\n");
Buffer = MemoryBuffer::getNewMemBuffer(Entry->getSize(), "<invalid>");
char *Ptr = const_cast<char*>(Buffer->getBufferStart());
for (unsigned i = 0, e = Entry->getSize(); i != e; ++i)
Ptr[i] = FillStr[i % FillStr.size()];
}
}
return Buffer;
}
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);
const SrcMgr::FileInfo &FileInfo = getSLocEntry(LocInfo.first).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);
const SrcMgr::FileInfo &FileInfo = getSLocEntry(LocInfo.first).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() {
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);
}
}
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);
new (Entry) ContentCache(FileEnt);
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;
SLocEntryLoaded.resize(NumSLocEntries + 1);
SLocEntryLoaded[0] = true;
SLocEntryTable.resize(SLocEntryTable.size() + NumSLocEntries);
}
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;
}
//===----------------------------------------------------------------------===//
// 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 LastFileIDLookup = 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) {
const SrcMgr::ContentCache *IR = getOrCreateContentCache(File);
if (IR == 0)
return 0;
return IR->getBuffer();
}
bool SourceManager::overrideFileContents(const FileEntry *SourceFile,
const llvm::MemoryBuffer *Buffer) {
const SrcMgr::ContentCache *IR = getOrCreateContentCache(SourceFile);
if (IR == 0)
return true;
const_cast<SrcMgr::ContentCache *>(IR)->replaceBuffer(Buffer);
return false;
}
/// getBufferData - Return a pointer to the start and end of the source buffer
/// data for the specified FileID.
std::pair<const char*, const char*>
SourceManager::getBufferData(FileID FID) const {
const llvm::MemoryBuffer *Buf = getBuffer(FID);
return std::make_pair(Buf->getBufferStart(), Buf->getBufferEnd());
}
//===----------------------------------------------------------------------===//
// 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 {
assert(SLocOffset && "Invalid FileID");
// 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)
getSLocEntry(FileID::get(I - SLocEntryTable.begin()));
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) {
unsigned MiddleIndex = (GreaterIndex-LessIndex)/2+LessIndex;
unsigned MidOffset = getSLocEntry(FileID::get(MiddleIndex)).getOffset();
++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 {
std::pair<FileID, unsigned> LocInfo = getDecomposedLoc(Loc);
Loc = getSLocEntry(LocInfo.first).getInstantiation()
.getInstantiationLocStart();
Loc = Loc.getFileLocWithOffset(LocInfo.second);
} 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) 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.
return getSLocEntry(LocInfo.first).getFile().getContentCache()
->getBuffer()->getBufferStart() + 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) const {
const char *Buf = getBuffer(FID)->getBufferStart();
unsigned LineStart = FilePos;
while (LineStart && Buf[LineStart-1] != '\n' && Buf[LineStart-1] != '\r')
--LineStart;
return FilePos-LineStart+1;
}
unsigned SourceManager::getSpellingColumnNumber(SourceLocation Loc) const {
if (Loc.isInvalid()) return 0;
std::pair<FileID, unsigned> LocInfo = getDecomposedSpellingLoc(Loc);
return getColumnNumber(LocInfo.first, LocInfo.second);
}
unsigned SourceManager::getInstantiationColumnNumber(SourceLocation Loc) const {
if (Loc.isInvalid()) return 0;
std::pair<FileID, unsigned> LocInfo = getDecomposedInstantiationLoc(Loc);
return getColumnNumber(LocInfo.first, LocInfo.second);
}
static DISABLE_INLINE void ComputeLineNumbers(ContentCache* FI,
llvm::BumpPtrAllocator &Alloc);
static void ComputeLineNumbers(ContentCache* FI, llvm::BumpPtrAllocator &Alloc){
// Note that calling 'getBuffer()' may lazily page in the file.
const MemoryBuffer *Buffer = FI->getBuffer();
// 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) const {
ContentCache *Content;
if (LastLineNoFileIDQuery == FID)
Content = LastLineNoContentCache;
else
Content = const_cast<ContentCache*>(getSLocEntry(FID)
.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)
ComputeLineNumbers(Content, ContentCacheAlloc);
// 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::getInstantiationLineNumber(SourceLocation Loc) const {
if (Loc.isInvalid()) return 0;
std::pair<FileID, unsigned> LocInfo = getDecomposedInstantiationLoc(Loc);
return getLineNumber(LocInfo.first, LocInfo.second);
}
unsigned SourceManager::getSpellingLineNumber(SourceLocation Loc) const {
if (Loc.isInvalid()) return 0;
std::pair<FileID, unsigned> LocInfo = getDecomposedSpellingLoc(Loc);
return getLineNumber(LocInfo.first, LocInfo.second);
}
/// 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);
const SrcMgr::FileInfo &FI = getSLocEntry(LocInfo.first).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) const {
if (Loc.isInvalid()) return "<invalid loc>";
return getBuffer(getFileID(Loc))->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);
const SrcMgr::FileInfo &FI = getSLocEntry(LocInfo.first).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 =
C->Entry ? C->Entry->getName() : C->getBuffer()->getBufferIdentifier();
unsigned LineNo = getLineNumber(LocInfo.first, LocInfo.second);
unsigned ColNo = getColumnNumber(LocInfo.first, LocInfo.second);
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 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) const {
assert(SourceFile && "Null source file!");
assert(Line && Col && "Line and column should start from 1!");
fileinfo_iterator FI = FileInfos.find(SourceFile);
if (FI == FileInfos.end())
return SourceLocation();
ContentCache *Content = FI->second;
// If this is the first use of line information for this buffer, compute the
/// SourceLineCache for it on demand.
if (Content->SourceLineCache == 0)
ComputeLineNumbers(Content, ContentCacheAlloc);
if (Line > Content->NumLines)
return SourceLocation();
unsigned FilePos = Content->SourceLineCache[Line - 1];
const char *Buf = Content->getBuffer()->getBufferStart() + FilePos;
unsigned BufLength = Content->getBuffer()->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 SourceLocation();
// 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.
if (!MainFileID.isInvalid()) {
const SLocEntry &MainSLoc = getSLocEntry(MainFileID);
if (MainSLoc.isFile() && MainSLoc.getFile().getContentCache() == Content)
FirstFID = MainFileID;
}
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) {
const SLocEntry &SLoc = getSLocEntry(I);
if (SLoc.isFile() && SLoc.getFile().getContentCache() == Content) {
FirstFID = FileID::get(I);
break;
}
}
}
if (FirstFID.isInvalid())
return SourceLocation();
return getLocForStartOfFile(FirstFID).getFileLocWithOffset(FilePos + Col - 1);
}
/// \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;
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 (LastLFIDForBeforeTUCheck == LOffs.first &&
LastRFIDForBeforeTUCheck == ROffs.first)
return LastResForBeforeTUCheck;
LastLFIDForBeforeTUCheck = LOffs.first;
LastRFIDForBeforeTUCheck = ROffs.first;
// "Traverse" the include/instantiation stacks of both locations and try to
// find a common "ancestor".
//
// First we traverse the stack of the right location and check each level
// against the level of the left location, while collecting all levels in a
// "stack map".
std::map<FileID, unsigned> ROffsMap;
ROffsMap[ROffs.first] = ROffs.second;
while (1) {
SourceLocation UpperLoc;
const SrcMgr::SLocEntry &Entry = getSLocEntry(ROffs.first);
if (Entry.isInstantiation())
UpperLoc = Entry.getInstantiation().getInstantiationLocStart();
else
UpperLoc = Entry.getFile().getIncludeLoc();
if (UpperLoc.isInvalid())
break; // We reached the top.
ROffs = getDecomposedLoc(UpperLoc);
if (LOffs.first == ROffs.first)
return LastResForBeforeTUCheck = LOffs.second < ROffs.second;
ROffsMap[ROffs.first] = ROffs.second;
}
// We didn't find a common ancestor. Now traverse the stack of the left
// location, checking against the stack map of the right location.
while (1) {
SourceLocation UpperLoc;
const SrcMgr::SLocEntry &Entry = getSLocEntry(LOffs.first);
if (Entry.isInstantiation())
UpperLoc = Entry.getInstantiation().getInstantiationLocStart();
else
UpperLoc = Entry.getFile().getIncludeLoc();
if (UpperLoc.isInvalid())
break; // We reached the top.
LOffs = getDecomposedLoc(UpperLoc);
std::map<FileID, unsigned>::iterator I = ROffsMap.find(LOffs.first);
if (I != ROffsMap.end())
return LastResForBeforeTUCheck = LOffs.second < I->second;
}
// There is no common ancestor, most probably because one location is in the
// predefines buffer.
//
// FIXME: We should rearrange the external interface so this simply never
// happens; it can't conceptually happen. Also see PR5662.
// If exactly one location is a memory buffer, assume it preceeds the other.
bool LIsMB = !getSLocEntry(LOffs.first).getFile().getContentCache()->Entry;
bool RIsMB = !getSLocEntry(ROffs.first).getFile().getContentCache()->Entry;
if (LIsMB != RIsMB)
return LastResForBeforeTUCheck = LIsMB;
// Otherwise, just assume FileIDs were created in order.
return LastResForBeforeTUCheck = (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() { }