diff options
Diffstat (limited to 'lib/Basic/FileManager.cpp')
| -rw-r--r-- | lib/Basic/FileManager.cpp | 575 |
1 files changed, 0 insertions, 575 deletions
diff --git a/lib/Basic/FileManager.cpp b/lib/Basic/FileManager.cpp deleted file mode 100644 index 88a7a12508375..0000000000000 --- a/lib/Basic/FileManager.cpp +++ /dev/null @@ -1,575 +0,0 @@ -//===--- FileManager.cpp - File System Probing and Caching ----------------===// -// -// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. -// See https://llvm.org/LICENSE.txt for license information. -// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception -// -//===----------------------------------------------------------------------===// -// -// This file implements the FileManager interface. -// -//===----------------------------------------------------------------------===// -// -// TODO: This should index all interesting directories with dirent calls. -// getdirentries ? -// opendir/readdir_r/closedir ? -// -//===----------------------------------------------------------------------===// - -#include "clang/Basic/FileManager.h" -#include "clang/Basic/FileSystemStatCache.h" -#include "llvm/ADT/STLExtras.h" -#include "llvm/ADT/SmallString.h" -#include "llvm/ADT/Statistic.h" -#include "llvm/Config/llvm-config.h" -#include "llvm/Support/FileSystem.h" -#include "llvm/Support/MemoryBuffer.h" -#include "llvm/Support/Path.h" -#include "llvm/Support/raw_ostream.h" -#include <algorithm> -#include <cassert> -#include <climits> -#include <cstdint> -#include <cstdlib> -#include <string> -#include <utility> - -using namespace clang; - -#define DEBUG_TYPE "file-search" - -ALWAYS_ENABLED_STATISTIC(NumDirLookups, "Number of directory lookups."); -ALWAYS_ENABLED_STATISTIC(NumFileLookups, "Number of file lookups."); -ALWAYS_ENABLED_STATISTIC(NumDirCacheMisses, - "Number of directory cache misses."); -ALWAYS_ENABLED_STATISTIC(NumFileCacheMisses, "Number of file cache misses."); - -//===----------------------------------------------------------------------===// -// Common logic. -//===----------------------------------------------------------------------===// - -FileManager::FileManager(const FileSystemOptions &FSO, - IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS) - : FS(std::move(FS)), FileSystemOpts(FSO), SeenDirEntries(64), - SeenFileEntries(64), NextFileUID(0) { - // If the caller doesn't provide a virtual file system, just grab the real - // file system. - if (!this->FS) - this->FS = llvm::vfs::getRealFileSystem(); -} - -FileManager::~FileManager() = default; - -void FileManager::setStatCache(std::unique_ptr<FileSystemStatCache> statCache) { - assert(statCache && "No stat cache provided?"); - StatCache = std::move(statCache); -} - -void FileManager::clearStatCache() { StatCache.reset(); } - -/// Retrieve the directory that the given file name resides in. -/// Filename can point to either a real file or a virtual file. -static llvm::ErrorOr<const DirectoryEntry *> -getDirectoryFromFile(FileManager &FileMgr, StringRef Filename, - bool CacheFailure) { - if (Filename.empty()) - return std::errc::no_such_file_or_directory; - - if (llvm::sys::path::is_separator(Filename[Filename.size() - 1])) - return std::errc::is_a_directory; - - StringRef DirName = llvm::sys::path::parent_path(Filename); - // Use the current directory if file has no path component. - if (DirName.empty()) - DirName = "."; - - return FileMgr.getDirectory(DirName, CacheFailure); -} - -/// Add all ancestors of the given path (pointing to either a file or -/// a directory) as virtual directories. -void FileManager::addAncestorsAsVirtualDirs(StringRef Path) { - StringRef DirName = llvm::sys::path::parent_path(Path); - if (DirName.empty()) - DirName = "."; - - auto &NamedDirEnt = *SeenDirEntries.insert( - {DirName, std::errc::no_such_file_or_directory}).first; - - // When caching a virtual directory, we always cache its ancestors - // at the same time. Therefore, if DirName is already in the cache, - // we don't need to recurse as its ancestors must also already be in - // the cache (or it's a known non-virtual directory). - if (NamedDirEnt.second) - return; - - // Add the virtual directory to the cache. - auto UDE = std::make_unique<DirectoryEntry>(); - UDE->Name = NamedDirEnt.first(); - NamedDirEnt.second = *UDE.get(); - VirtualDirectoryEntries.push_back(std::move(UDE)); - - // Recursively add the other ancestors. - addAncestorsAsVirtualDirs(DirName); -} - -llvm::Expected<DirectoryEntryRef> -FileManager::getDirectoryRef(StringRef DirName, bool CacheFailure) { - // stat doesn't like trailing separators except for root directory. - // At least, on Win32 MSVCRT, stat() cannot strip trailing '/'. - // (though it can strip '\\') - if (DirName.size() > 1 && - DirName != llvm::sys::path::root_path(DirName) && - llvm::sys::path::is_separator(DirName.back())) - DirName = DirName.substr(0, DirName.size()-1); -#ifdef _WIN32 - // Fixing a problem with "clang C:test.c" on Windows. - // Stat("C:") does not recognize "C:" as a valid directory - std::string DirNameStr; - if (DirName.size() > 1 && DirName.back() == ':' && - DirName.equals_lower(llvm::sys::path::root_name(DirName))) { - DirNameStr = DirName.str() + '.'; - DirName = DirNameStr; - } -#endif - - ++NumDirLookups; - - // See if there was already an entry in the map. Note that the map - // contains both virtual and real directories. - auto SeenDirInsertResult = - SeenDirEntries.insert({DirName, std::errc::no_such_file_or_directory}); - if (!SeenDirInsertResult.second) { - if (SeenDirInsertResult.first->second) - return DirectoryEntryRef(&*SeenDirInsertResult.first); - return llvm::errorCodeToError(SeenDirInsertResult.first->second.getError()); - } - - // We've not seen this before. Fill it in. - ++NumDirCacheMisses; - auto &NamedDirEnt = *SeenDirInsertResult.first; - assert(!NamedDirEnt.second && "should be newly-created"); - - // Get the null-terminated directory name as stored as the key of the - // SeenDirEntries map. - StringRef InterndDirName = NamedDirEnt.first(); - - // Check to see if the directory exists. - llvm::vfs::Status Status; - auto statError = getStatValue(InterndDirName, Status, false, - nullptr /*directory lookup*/); - if (statError) { - // There's no real directory at the given path. - if (CacheFailure) - NamedDirEnt.second = statError; - else - SeenDirEntries.erase(DirName); - return llvm::errorCodeToError(statError); - } - - // It exists. See if we have already opened a directory with the - // same inode (this occurs on Unix-like systems when one dir is - // symlinked to another, for example) or the same path (on - // Windows). - DirectoryEntry &UDE = UniqueRealDirs[Status.getUniqueID()]; - - NamedDirEnt.second = UDE; - if (UDE.getName().empty()) { - // We don't have this directory yet, add it. We use the string - // key from the SeenDirEntries map as the string. - UDE.Name = InterndDirName; - } - - return DirectoryEntryRef(&NamedDirEnt); -} - -llvm::ErrorOr<const DirectoryEntry *> -FileManager::getDirectory(StringRef DirName, bool CacheFailure) { - auto Result = getDirectoryRef(DirName, CacheFailure); - if (Result) - return &Result->getDirEntry(); - return llvm::errorToErrorCode(Result.takeError()); -} - -llvm::ErrorOr<const FileEntry *> -FileManager::getFile(StringRef Filename, bool openFile, bool CacheFailure) { - auto Result = getFileRef(Filename, openFile, CacheFailure); - if (Result) - return &Result->getFileEntry(); - return llvm::errorToErrorCode(Result.takeError()); -} - -llvm::Expected<FileEntryRef> -FileManager::getFileRef(StringRef Filename, bool openFile, bool CacheFailure) { - ++NumFileLookups; - - // See if there is already an entry in the map. - auto SeenFileInsertResult = - SeenFileEntries.insert({Filename, std::errc::no_such_file_or_directory}); - if (!SeenFileInsertResult.second) { - if (!SeenFileInsertResult.first->second) - return llvm::errorCodeToError( - SeenFileInsertResult.first->second.getError()); - // Construct and return and FileEntryRef, unless it's a redirect to another - // filename. - SeenFileEntryOrRedirect Value = *SeenFileInsertResult.first->second; - FileEntry *FE; - if (LLVM_LIKELY(FE = Value.dyn_cast<FileEntry *>())) - return FileEntryRef(SeenFileInsertResult.first->first(), *FE); - return getFileRef(*Value.get<const StringRef *>(), openFile, CacheFailure); - } - - // We've not seen this before. Fill it in. - ++NumFileCacheMisses; - auto &NamedFileEnt = *SeenFileInsertResult.first; - assert(!NamedFileEnt.second && "should be newly-created"); - - // Get the null-terminated file name as stored as the key of the - // SeenFileEntries map. - StringRef InterndFileName = NamedFileEnt.first(); - - // Look up the directory for the file. When looking up something like - // sys/foo.h we'll discover all of the search directories that have a 'sys' - // subdirectory. This will let us avoid having to waste time on known-to-fail - // searches when we go to find sys/bar.h, because all the search directories - // without a 'sys' subdir will get a cached failure result. - auto DirInfoOrErr = getDirectoryFromFile(*this, Filename, CacheFailure); - if (!DirInfoOrErr) { // Directory doesn't exist, file can't exist. - if (CacheFailure) - NamedFileEnt.second = DirInfoOrErr.getError(); - else - SeenFileEntries.erase(Filename); - - return llvm::errorCodeToError(DirInfoOrErr.getError()); - } - const DirectoryEntry *DirInfo = *DirInfoOrErr; - - // FIXME: Use the directory info to prune this, before doing the stat syscall. - // FIXME: This will reduce the # syscalls. - - // Check to see if the file exists. - std::unique_ptr<llvm::vfs::File> F; - llvm::vfs::Status Status; - auto statError = getStatValue(InterndFileName, Status, true, - openFile ? &F : nullptr); - if (statError) { - // There's no real file at the given path. - if (CacheFailure) - NamedFileEnt.second = statError; - else - SeenFileEntries.erase(Filename); - - return llvm::errorCodeToError(statError); - } - - assert((openFile || !F) && "undesired open file"); - - // It exists. See if we have already opened a file with the same inode. - // This occurs when one dir is symlinked to another, for example. - FileEntry &UFE = UniqueRealFiles[Status.getUniqueID()]; - - NamedFileEnt.second = &UFE; - - // If the name returned by getStatValue is different than Filename, re-intern - // the name. - if (Status.getName() != Filename) { - auto &NewNamedFileEnt = - *SeenFileEntries.insert({Status.getName(), &UFE}).first; - assert((*NewNamedFileEnt.second).get<FileEntry *>() == &UFE && - "filename from getStatValue() refers to wrong file"); - InterndFileName = NewNamedFileEnt.first().data(); - // In addition to re-interning the name, construct a redirecting seen file - // entry, that will point to the name the filesystem actually wants to use. - StringRef *Redirect = new (CanonicalNameStorage) StringRef(InterndFileName); - NamedFileEnt.second = Redirect; - } - - if (UFE.isValid()) { // Already have an entry with this inode, return it. - - // FIXME: this hack ensures that if we look up a file by a virtual path in - // the VFS that the getDir() will have the virtual path, even if we found - // the file by a 'real' path first. This is required in order to find a - // module's structure when its headers/module map are mapped in the VFS. - // We should remove this as soon as we can properly support a file having - // multiple names. - if (DirInfo != UFE.Dir && Status.IsVFSMapped) - UFE.Dir = DirInfo; - - // Always update the name to use the last name by which a file was accessed. - // FIXME: Neither this nor always using the first name is correct; we want - // to switch towards a design where we return a FileName object that - // encapsulates both the name by which the file was accessed and the - // corresponding FileEntry. - // FIXME: The Name should be removed from FileEntry once all clients - // adopt FileEntryRef. - UFE.Name = InterndFileName; - - return FileEntryRef(InterndFileName, UFE); - } - - // Otherwise, we don't have this file yet, add it. - UFE.Name = InterndFileName; - UFE.Size = Status.getSize(); - UFE.ModTime = llvm::sys::toTimeT(Status.getLastModificationTime()); - UFE.Dir = DirInfo; - UFE.UID = NextFileUID++; - UFE.UniqueID = Status.getUniqueID(); - UFE.IsNamedPipe = Status.getType() == llvm::sys::fs::file_type::fifo_file; - UFE.File = std::move(F); - UFE.IsValid = true; - - if (UFE.File) { - if (auto PathName = UFE.File->getName()) - fillRealPathName(&UFE, *PathName); - } else if (!openFile) { - // We should still fill the path even if we aren't opening the file. - fillRealPathName(&UFE, InterndFileName); - } - return FileEntryRef(InterndFileName, UFE); -} - -const FileEntry * -FileManager::getVirtualFile(StringRef Filename, off_t Size, - time_t ModificationTime) { - ++NumFileLookups; - - // See if there is already an entry in the map for an existing file. - auto &NamedFileEnt = *SeenFileEntries.insert( - {Filename, std::errc::no_such_file_or_directory}).first; - if (NamedFileEnt.second) { - SeenFileEntryOrRedirect Value = *NamedFileEnt.second; - FileEntry *FE; - if (LLVM_LIKELY(FE = Value.dyn_cast<FileEntry *>())) - return FE; - return getVirtualFile(*Value.get<const StringRef *>(), Size, - ModificationTime); - } - - // We've not seen this before, or the file is cached as non-existent. - ++NumFileCacheMisses; - addAncestorsAsVirtualDirs(Filename); - FileEntry *UFE = nullptr; - - // Now that all ancestors of Filename are in the cache, the - // following call is guaranteed to find the DirectoryEntry from the - // cache. - auto DirInfo = getDirectoryFromFile(*this, Filename, /*CacheFailure=*/true); - assert(DirInfo && - "The directory of a virtual file should already be in the cache."); - - // Check to see if the file exists. If so, drop the virtual file - llvm::vfs::Status Status; - const char *InterndFileName = NamedFileEnt.first().data(); - if (!getStatValue(InterndFileName, Status, true, nullptr)) { - UFE = &UniqueRealFiles[Status.getUniqueID()]; - Status = llvm::vfs::Status( - Status.getName(), Status.getUniqueID(), - llvm::sys::toTimePoint(ModificationTime), - Status.getUser(), Status.getGroup(), Size, - Status.getType(), Status.getPermissions()); - - NamedFileEnt.second = UFE; - - // If we had already opened this file, close it now so we don't - // leak the descriptor. We're not going to use the file - // descriptor anyway, since this is a virtual file. - if (UFE->File) - UFE->closeFile(); - - // If we already have an entry with this inode, return it. - if (UFE->isValid()) - return UFE; - - UFE->UniqueID = Status.getUniqueID(); - UFE->IsNamedPipe = Status.getType() == llvm::sys::fs::file_type::fifo_file; - fillRealPathName(UFE, Status.getName()); - } else { - VirtualFileEntries.push_back(std::make_unique<FileEntry>()); - UFE = VirtualFileEntries.back().get(); - NamedFileEnt.second = UFE; - } - - UFE->Name = InterndFileName; - UFE->Size = Size; - UFE->ModTime = ModificationTime; - UFE->Dir = *DirInfo; - UFE->UID = NextFileUID++; - UFE->IsValid = true; - UFE->File.reset(); - return UFE; -} - -llvm::Optional<FileEntryRef> FileManager::getBypassFile(FileEntryRef VF) { - // Stat of the file and return nullptr if it doesn't exist. - llvm::vfs::Status Status; - if (getStatValue(VF.getName(), Status, /*isFile=*/true, /*F=*/nullptr)) - return None; - - // Fill it in from the stat. - BypassFileEntries.push_back(std::make_unique<FileEntry>()); - const FileEntry &VFE = VF.getFileEntry(); - FileEntry &BFE = *BypassFileEntries.back(); - BFE.Name = VFE.getName(); - BFE.Size = Status.getSize(); - BFE.Dir = VFE.Dir; - BFE.ModTime = llvm::sys::toTimeT(Status.getLastModificationTime()); - BFE.UID = NextFileUID++; - BFE.IsValid = true; - return FileEntryRef(VF.getName(), BFE); -} - -bool FileManager::FixupRelativePath(SmallVectorImpl<char> &path) const { - StringRef pathRef(path.data(), path.size()); - - if (FileSystemOpts.WorkingDir.empty() - || llvm::sys::path::is_absolute(pathRef)) - return false; - - SmallString<128> NewPath(FileSystemOpts.WorkingDir); - llvm::sys::path::append(NewPath, pathRef); - path = NewPath; - return true; -} - -bool FileManager::makeAbsolutePath(SmallVectorImpl<char> &Path) const { - bool Changed = FixupRelativePath(Path); - - if (!llvm::sys::path::is_absolute(StringRef(Path.data(), Path.size()))) { - FS->makeAbsolute(Path); - Changed = true; - } - - return Changed; -} - -void FileManager::fillRealPathName(FileEntry *UFE, llvm::StringRef FileName) { - llvm::SmallString<128> AbsPath(FileName); - // This is not the same as `VFS::getRealPath()`, which resolves symlinks - // but can be very expensive on real file systems. - // FIXME: the semantic of RealPathName is unclear, and the name might be - // misleading. We need to clean up the interface here. - makeAbsolutePath(AbsPath); - llvm::sys::path::remove_dots(AbsPath, /*remove_dot_dot=*/true); - UFE->RealPathName = AbsPath.str(); -} - -llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> -FileManager::getBufferForFile(const FileEntry *Entry, bool isVolatile) { - uint64_t FileSize = Entry->getSize(); - // If there's a high enough chance that the file have changed since we - // got its size, force a stat before opening it. - if (isVolatile) - FileSize = -1; - - StringRef Filename = Entry->getName(); - // If the file is already open, use the open file descriptor. - if (Entry->File) { - auto Result = - Entry->File->getBuffer(Filename, FileSize, - /*RequiresNullTerminator=*/true, isVolatile); - Entry->closeFile(); - return Result; - } - - // Otherwise, open the file. - return getBufferForFileImpl(Filename, FileSize, isVolatile); -} - -llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> -FileManager::getBufferForFileImpl(StringRef Filename, int64_t FileSize, - bool isVolatile) { - if (FileSystemOpts.WorkingDir.empty()) - return FS->getBufferForFile(Filename, FileSize, - /*RequiresNullTerminator=*/true, isVolatile); - - SmallString<128> FilePath(Filename); - FixupRelativePath(FilePath); - return FS->getBufferForFile(FilePath, FileSize, - /*RequiresNullTerminator=*/true, isVolatile); -} - -/// getStatValue - Get the 'stat' information for the specified path, -/// using the cache to accelerate it if possible. This returns true -/// if the path points to a virtual file or does not exist, or returns -/// false if it's an existent real file. If FileDescriptor is NULL, -/// do directory look-up instead of file look-up. -std::error_code -FileManager::getStatValue(StringRef Path, llvm::vfs::Status &Status, - bool isFile, std::unique_ptr<llvm::vfs::File> *F) { - // FIXME: FileSystemOpts shouldn't be passed in here, all paths should be - // absolute! - if (FileSystemOpts.WorkingDir.empty()) - return FileSystemStatCache::get(Path, Status, isFile, F, - StatCache.get(), *FS); - - SmallString<128> FilePath(Path); - FixupRelativePath(FilePath); - - return FileSystemStatCache::get(FilePath.c_str(), Status, isFile, F, - StatCache.get(), *FS); -} - -std::error_code -FileManager::getNoncachedStatValue(StringRef Path, - llvm::vfs::Status &Result) { - SmallString<128> FilePath(Path); - FixupRelativePath(FilePath); - - llvm::ErrorOr<llvm::vfs::Status> S = FS->status(FilePath.c_str()); - if (!S) - return S.getError(); - Result = *S; - return std::error_code(); -} - -void FileManager::GetUniqueIDMapping( - SmallVectorImpl<const FileEntry *> &UIDToFiles) const { - UIDToFiles.clear(); - UIDToFiles.resize(NextFileUID); - - // Map file entries - for (llvm::StringMap<llvm::ErrorOr<SeenFileEntryOrRedirect>, - llvm::BumpPtrAllocator>::const_iterator - FE = SeenFileEntries.begin(), - FEEnd = SeenFileEntries.end(); - FE != FEEnd; ++FE) - if (llvm::ErrorOr<SeenFileEntryOrRedirect> Entry = FE->getValue()) { - if (const auto *FE = (*Entry).dyn_cast<FileEntry *>()) - UIDToFiles[FE->getUID()] = FE; - } - - // Map virtual file entries - for (const auto &VFE : VirtualFileEntries) - UIDToFiles[VFE->getUID()] = VFE.get(); -} - -StringRef FileManager::getCanonicalName(const DirectoryEntry *Dir) { - // FIXME: use llvm::sys::fs::canonical() when it gets implemented - llvm::DenseMap<const DirectoryEntry *, llvm::StringRef>::iterator Known - = CanonicalDirNames.find(Dir); - if (Known != CanonicalDirNames.end()) - return Known->second; - - StringRef CanonicalName(Dir->getName()); - - SmallString<4096> CanonicalNameBuf; - if (!FS->getRealPath(Dir->getName(), CanonicalNameBuf)) - CanonicalName = StringRef(CanonicalNameBuf).copy(CanonicalNameStorage); - - CanonicalDirNames.insert({Dir, CanonicalName}); - return CanonicalName; -} - -void FileManager::PrintStats() const { - llvm::errs() << "\n*** File Manager Stats:\n"; - llvm::errs() << UniqueRealFiles.size() << " real files found, " - << UniqueRealDirs.size() << " real dirs found.\n"; - llvm::errs() << VirtualFileEntries.size() << " virtual files found, " - << VirtualDirectoryEntries.size() << " virtual dirs found.\n"; - llvm::errs() << NumDirLookups << " dir lookups, " - << NumDirCacheMisses << " dir cache misses.\n"; - llvm::errs() << NumFileLookups << " file lookups, " - << NumFileCacheMisses << " file cache misses.\n"; - - //llvm::errs() << PagesMapped << BytesOfPagesMapped << FSLookups; -} |