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Diffstat (limited to 'lib/Basic/SourceManager.cpp')
| -rw-r--r-- | lib/Basic/SourceManager.cpp | 943 |
1 files changed, 943 insertions, 0 deletions
diff --git a/lib/Basic/SourceManager.cpp b/lib/Basic/SourceManager.cpp new file mode 100644 index 0000000..7d2d0ae --- /dev/null +++ b/lib/Basic/SourceManager.cpp @@ -0,0 +1,943 @@ +//===--- 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/System/Path.h" +#include "llvm/Support/Streams.h" +#include <algorithm> +#include <iostream> +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 Entry ? Entry->getSize() : Buffer->getBufferSize(); +} + +const llvm::MemoryBuffer *ContentCache::getBuffer() const { + // Lazily create the Buffer for ContentCaches that wrap files. + if (!Buffer && Entry) { + // FIXME: Should we support a way to not have to do this check over + // and over if we cannot open the file? + Buffer = MemoryBuffer::getFile(Entry->getName(), 0, Entry->getSize()); + } + 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) { + SLocEntry NewEntry = SLocEntry::get(NextOffset, + FileInfo::get(IncludePos, File, + FileCharacter)); + 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; + return LastFileIDLookup = FileID::get(PreallocatedID); + } + + 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. + return LastFileIDLookup = FileID::get(SLocEntryTable.size()-1); +} + +/// 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)); +} + +/// 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 void ComputeLineNumbers(ContentCache* FI, + llvm::BumpPtrAllocator &Alloc) DISABLE_INLINE; +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. +//===----------------------------------------------------------------------===// + + +/// PrintStats - Print statistics to stderr. +/// +void SourceManager::PrintStats() const { + llvm::cerr << "\n*** Source Manager Stats:\n"; + llvm::cerr << FileInfos.size() << " files mapped, " << MemBufferInfos.size() + << " mem buffers mapped.\n"; + llvm::cerr << 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::cerr << NumFileBytesMapped << " bytes of files mapped, " + << NumLineNumsComputed << " files with line #'s computed.\n"; + llvm::cerr << "FileID scans: " << NumLinearScans << " linear, " + << NumBinaryProbes << " binary.\n"; +} + +ExternalSLocEntrySource::~ExternalSLocEntrySource() { } |
