blob: 921af30bfcde9fb36c632ed1550417ece0964c6e [file] [log] [blame]
//===- VirtualFileSystem.cpp - Virtual File System Layer ------------------===//
//
// 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 VirtualFileSystem interface.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/VirtualFileSystem.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/IntrusiveRefCntPtr.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/StringSet.h"
#include "llvm/ADT/Twine.h"
#include "llvm/ADT/iterator_range.h"
#include "llvm/Config/llvm-config.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Chrono.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Errc.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/ErrorOr.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/FileSystem/UniqueID.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/SMLoc.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/YAMLParser.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <atomic>
#include <cassert>
#include <cstdint>
#include <iterator>
#include <limits>
#include <map>
#include <memory>
#include <optional>
#include <string>
#include <system_error>
#include <utility>
#include <vector>
using namespace llvm;
using namespace llvm::vfs;
using llvm::sys::fs::file_t;
using llvm::sys::fs::file_status;
using llvm::sys::fs::file_type;
using llvm::sys::fs::kInvalidFile;
using llvm::sys::fs::perms;
using llvm::sys::fs::UniqueID;
Status::Status(const file_status &Status)
: UID(Status.getUniqueID()), MTime(Status.getLastModificationTime()),
User(Status.getUser()), Group(Status.getGroup()), Size(Status.getSize()),
Type(Status.type()), Perms(Status.permissions()) {}
Status::Status(const Twine &Name, UniqueID UID, sys::TimePoint<> MTime,
uint32_t User, uint32_t Group, uint64_t Size, file_type Type,
perms Perms)
: Name(Name.str()), UID(UID), MTime(MTime), User(User), Group(Group),
Size(Size), Type(Type), Perms(Perms) {}
Status Status::copyWithNewSize(const Status &In, uint64_t NewSize) {
return Status(In.getName(), In.getUniqueID(), In.getLastModificationTime(),
In.getUser(), In.getGroup(), NewSize, In.getType(),
In.getPermissions());
}
Status Status::copyWithNewName(const Status &In, const Twine &NewName) {
return Status(NewName, In.getUniqueID(), In.getLastModificationTime(),
In.getUser(), In.getGroup(), In.getSize(), In.getType(),
In.getPermissions());
}
Status Status::copyWithNewName(const file_status &In, const Twine &NewName) {
return Status(NewName, In.getUniqueID(), In.getLastModificationTime(),
In.getUser(), In.getGroup(), In.getSize(), In.type(),
In.permissions());
}
bool Status::equivalent(const Status &Other) const {
assert(isStatusKnown() && Other.isStatusKnown());
return getUniqueID() == Other.getUniqueID();
}
bool Status::isDirectory() const { return Type == file_type::directory_file; }
bool Status::isRegularFile() const { return Type == file_type::regular_file; }
bool Status::isOther() const {
return exists() && !isRegularFile() && !isDirectory() && !isSymlink();
}
bool Status::isSymlink() const { return Type == file_type::symlink_file; }
bool Status::isStatusKnown() const { return Type != file_type::status_error; }
bool Status::exists() const {
return isStatusKnown() && Type != file_type::file_not_found;
}
File::~File() = default;
FileSystem::~FileSystem() = default;
ErrorOr<std::unique_ptr<MemoryBuffer>>
FileSystem::getBufferForFile(const llvm::Twine &Name, int64_t FileSize,
bool RequiresNullTerminator, bool IsVolatile) {
auto F = openFileForRead(Name);
if (!F)
return F.getError();
return (*F)->getBuffer(Name, FileSize, RequiresNullTerminator, IsVolatile);
}
std::error_code FileSystem::makeAbsolute(SmallVectorImpl<char> &Path) const {
if (llvm::sys::path::is_absolute(Path))
return {};
auto WorkingDir = getCurrentWorkingDirectory();
if (!WorkingDir)
return WorkingDir.getError();
llvm::sys::fs::make_absolute(WorkingDir.get(), Path);
return {};
}
std::error_code FileSystem::getRealPath(const Twine &Path,
SmallVectorImpl<char> &Output) {
return errc::operation_not_permitted;
}
std::error_code FileSystem::isLocal(const Twine &Path, bool &Result) {
return errc::operation_not_permitted;
}
bool FileSystem::exists(const Twine &Path) {
auto Status = status(Path);
return Status && Status->exists();
}
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
void FileSystem::dump() const { print(dbgs(), PrintType::RecursiveContents); }
#endif
#ifndef NDEBUG
static bool isTraversalComponent(StringRef Component) {
return Component.equals("..") || Component.equals(".");
}
static bool pathHasTraversal(StringRef Path) {
using namespace llvm::sys;
for (StringRef Comp : llvm::make_range(path::begin(Path), path::end(Path)))
if (isTraversalComponent(Comp))
return true;
return false;
}
#endif
//===-----------------------------------------------------------------------===/
// RealFileSystem implementation
//===-----------------------------------------------------------------------===/
namespace {
/// Wrapper around a raw file descriptor.
class RealFile : public File {
friend class RealFileSystem;
file_t FD;
Status S;
std::string RealName;
RealFile(file_t RawFD, StringRef NewName, StringRef NewRealPathName)
: FD(RawFD), S(NewName, {}, {}, {}, {}, {},
llvm::sys::fs::file_type::status_error, {}),
RealName(NewRealPathName.str()) {
assert(FD != kInvalidFile && "Invalid or inactive file descriptor");
}
public:
~RealFile() override;
ErrorOr<Status> status() override;
ErrorOr<std::string> getName() override;
ErrorOr<std::unique_ptr<MemoryBuffer>> getBuffer(const Twine &Name,
int64_t FileSize,
bool RequiresNullTerminator,
bool IsVolatile) override;
std::error_code close() override;
void setPath(const Twine &Path) override;
};
} // namespace
RealFile::~RealFile() { close(); }
ErrorOr<Status> RealFile::status() {
assert(FD != kInvalidFile && "cannot stat closed file");
if (!S.isStatusKnown()) {
file_status RealStatus;
if (std::error_code EC = sys::fs::status(FD, RealStatus))
return EC;
S = Status::copyWithNewName(RealStatus, S.getName());
}
return S;
}
ErrorOr<std::string> RealFile::getName() {
return RealName.empty() ? S.getName().str() : RealName;
}
ErrorOr<std::unique_ptr<MemoryBuffer>>
RealFile::getBuffer(const Twine &Name, int64_t FileSize,
bool RequiresNullTerminator, bool IsVolatile) {
assert(FD != kInvalidFile && "cannot get buffer for closed file");
return MemoryBuffer::getOpenFile(FD, Name, FileSize, RequiresNullTerminator,
IsVolatile);
}
std::error_code RealFile::close() {
std::error_code EC = sys::fs::closeFile(FD);
FD = kInvalidFile;
return EC;
}
void RealFile::setPath(const Twine &Path) {
RealName = Path.str();
if (auto Status = status())
S = Status.get().copyWithNewName(Status.get(), Path);
}
namespace {
/// A file system according to your operating system.
/// This may be linked to the process's working directory, or maintain its own.
///
/// Currently, its own working directory is emulated by storing the path and
/// sending absolute paths to llvm::sys::fs:: functions.
/// A more principled approach would be to push this down a level, modelling
/// the working dir as an llvm::sys::fs::WorkingDir or similar.
/// This would enable the use of openat()-style functions on some platforms.
class RealFileSystem : public FileSystem {
public:
explicit RealFileSystem(bool LinkCWDToProcess) {
if (!LinkCWDToProcess) {
SmallString<128> PWD, RealPWD;
if (std::error_code EC = llvm::sys::fs::current_path(PWD))
WD = EC;
else if (llvm::sys::fs::real_path(PWD, RealPWD))
WD = WorkingDirectory{PWD, PWD};
else
WD = WorkingDirectory{PWD, RealPWD};
}
}
ErrorOr<Status> status(const Twine &Path) override;
ErrorOr<std::unique_ptr<File>> openFileForRead(const Twine &Path) override;
directory_iterator dir_begin(const Twine &Dir, std::error_code &EC) override;
llvm::ErrorOr<std::string> getCurrentWorkingDirectory() const override;
std::error_code setCurrentWorkingDirectory(const Twine &Path) override;
std::error_code isLocal(const Twine &Path, bool &Result) override;
std::error_code getRealPath(const Twine &Path,
SmallVectorImpl<char> &Output) override;
protected:
void printImpl(raw_ostream &OS, PrintType Type,
unsigned IndentLevel) const override;
private:
// If this FS has its own working dir, use it to make Path absolute.
// The returned twine is safe to use as long as both Storage and Path live.
Twine adjustPath(const Twine &Path, SmallVectorImpl<char> &Storage) const {
if (!WD || !*WD)
return Path;
Path.toVector(Storage);
sys::fs::make_absolute(WD->get().Resolved, Storage);
return Storage;
}
struct WorkingDirectory {
// The current working directory, without symlinks resolved. (echo $PWD).
SmallString<128> Specified;
// The current working directory, with links resolved. (readlink .).
SmallString<128> Resolved;
};
std::optional<llvm::ErrorOr<WorkingDirectory>> WD;
};
} // namespace
ErrorOr<Status> RealFileSystem::status(const Twine &Path) {
SmallString<256> Storage;
sys::fs::file_status RealStatus;
if (std::error_code EC =
sys::fs::status(adjustPath(Path, Storage), RealStatus))
return EC;
return Status::copyWithNewName(RealStatus, Path);
}
ErrorOr<std::unique_ptr<File>>
RealFileSystem::openFileForRead(const Twine &Name) {
SmallString<256> RealName, Storage;
Expected<file_t> FDOrErr = sys::fs::openNativeFileForRead(
adjustPath(Name, Storage), sys::fs::OF_None, &RealName);
if (!FDOrErr)
return errorToErrorCode(FDOrErr.takeError());
return std::unique_ptr<File>(
new RealFile(*FDOrErr, Name.str(), RealName.str()));
}
llvm::ErrorOr<std::string> RealFileSystem::getCurrentWorkingDirectory() const {
if (WD && *WD)
return std::string(WD->get().Specified);
if (WD)
return WD->getError();
SmallString<128> Dir;
if (std::error_code EC = llvm::sys::fs::current_path(Dir))
return EC;
return std::string(Dir);
}
std::error_code RealFileSystem::setCurrentWorkingDirectory(const Twine &Path) {
if (!WD)
return llvm::sys::fs::set_current_path(Path);
SmallString<128> Absolute, Resolved, Storage;
adjustPath(Path, Storage).toVector(Absolute);
bool IsDir;
if (auto Err = llvm::sys::fs::is_directory(Absolute, IsDir))
return Err;
if (!IsDir)
return std::make_error_code(std::errc::not_a_directory);
if (auto Err = llvm::sys::fs::real_path(Absolute, Resolved))
return Err;
WD = WorkingDirectory{Absolute, Resolved};
return std::error_code();
}
std::error_code RealFileSystem::isLocal(const Twine &Path, bool &Result) {
SmallString<256> Storage;
return llvm::sys::fs::is_local(adjustPath(Path, Storage), Result);
}
std::error_code RealFileSystem::getRealPath(const Twine &Path,
SmallVectorImpl<char> &Output) {
SmallString<256> Storage;
return llvm::sys::fs::real_path(adjustPath(Path, Storage), Output);
}
void RealFileSystem::printImpl(raw_ostream &OS, PrintType Type,
unsigned IndentLevel) const {
printIndent(OS, IndentLevel);
OS << "RealFileSystem using ";
if (WD)
OS << "own";
else
OS << "process";
OS << " CWD\n";
}
IntrusiveRefCntPtr<FileSystem> vfs::getRealFileSystem() {
static IntrusiveRefCntPtr<FileSystem> FS(new RealFileSystem(true));
return FS;
}
std::unique_ptr<FileSystem> vfs::createPhysicalFileSystem() {
return std::make_unique<RealFileSystem>(false);
}
namespace {
class RealFSDirIter : public llvm::vfs::detail::DirIterImpl {
llvm::sys::fs::directory_iterator Iter;
public:
RealFSDirIter(const Twine &Path, std::error_code &EC) : Iter(Path, EC) {
if (Iter != llvm::sys::fs::directory_iterator())
CurrentEntry = directory_entry(Iter->path(), Iter->type());
}
std::error_code increment() override {
std::error_code EC;
Iter.increment(EC);
CurrentEntry = (Iter == llvm::sys::fs::directory_iterator())
? directory_entry()
: directory_entry(Iter->path(), Iter->type());
return EC;
}
};
} // namespace
directory_iterator RealFileSystem::dir_begin(const Twine &Dir,
std::error_code &EC) {
SmallString<128> Storage;
return directory_iterator(
std::make_shared<RealFSDirIter>(adjustPath(Dir, Storage), EC));
}
//===-----------------------------------------------------------------------===/
// OverlayFileSystem implementation
//===-----------------------------------------------------------------------===/
OverlayFileSystem::OverlayFileSystem(IntrusiveRefCntPtr<FileSystem> BaseFS) {
FSList.push_back(std::move(BaseFS));
}
void OverlayFileSystem::pushOverlay(IntrusiveRefCntPtr<FileSystem> FS) {
FSList.push_back(FS);
// Synchronize added file systems by duplicating the working directory from
// the first one in the list.
FS->setCurrentWorkingDirectory(getCurrentWorkingDirectory().get());
}
ErrorOr<Status> OverlayFileSystem::status(const Twine &Path) {
// FIXME: handle symlinks that cross file systems
for (iterator I = overlays_begin(), E = overlays_end(); I != E; ++I) {
ErrorOr<Status> Status = (*I)->status(Path);
if (Status || Status.getError() != llvm::errc::no_such_file_or_directory)
return Status;
}
return make_error_code(llvm::errc::no_such_file_or_directory);
}
bool OverlayFileSystem::exists(const Twine &Path) {
// FIXME: handle symlinks that cross file systems
for (iterator I = overlays_begin(), E = overlays_end(); I != E; ++I) {
if ((*I)->exists(Path))
return true;
}
return false;
}
ErrorOr<std::unique_ptr<File>>
OverlayFileSystem::openFileForRead(const llvm::Twine &Path) {
// FIXME: handle symlinks that cross file systems
for (iterator I = overlays_begin(), E = overlays_end(); I != E; ++I) {
auto Result = (*I)->openFileForRead(Path);
if (Result || Result.getError() != llvm::errc::no_such_file_or_directory)
return Result;
}
return make_error_code(llvm::errc::no_such_file_or_directory);
}
llvm::ErrorOr<std::string>
OverlayFileSystem::getCurrentWorkingDirectory() const {
// All file systems are synchronized, just take the first working directory.
return FSList.front()->getCurrentWorkingDirectory();
}
std::error_code
OverlayFileSystem::setCurrentWorkingDirectory(const Twine &Path) {
for (auto &FS : FSList)
if (std::error_code EC = FS->setCurrentWorkingDirectory(Path))
return EC;
return {};
}
std::error_code OverlayFileSystem::isLocal(const Twine &Path, bool &Result) {
for (auto &FS : FSList)
if (FS->exists(Path))
return FS->isLocal(Path, Result);
return errc::no_such_file_or_directory;
}
std::error_code OverlayFileSystem::getRealPath(const Twine &Path,
SmallVectorImpl<char> &Output) {
for (const auto &FS : FSList)
if (FS->exists(Path))
return FS->getRealPath(Path, Output);
return errc::no_such_file_or_directory;
}
void OverlayFileSystem::visitChildFileSystems(VisitCallbackTy Callback) {
for (IntrusiveRefCntPtr<FileSystem> FS : overlays_range()) {
Callback(*FS);
FS->visitChildFileSystems(Callback);
}
}
void OverlayFileSystem::printImpl(raw_ostream &OS, PrintType Type,
unsigned IndentLevel) const {
printIndent(OS, IndentLevel);
OS << "OverlayFileSystem\n";
if (Type == PrintType::Summary)
return;
if (Type == PrintType::Contents)
Type = PrintType::Summary;
for (const auto &FS : overlays_range())
FS->print(OS, Type, IndentLevel + 1);
}
llvm::vfs::detail::DirIterImpl::~DirIterImpl() = default;
namespace {
/// Combines and deduplicates directory entries across multiple file systems.
class CombiningDirIterImpl : public llvm::vfs::detail::DirIterImpl {
using FileSystemPtr = llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>;
/// Iterators to combine, processed in reverse order.
SmallVector<directory_iterator, 8> IterList;
/// The iterator currently being traversed.
directory_iterator CurrentDirIter;
/// The set of names already returned as entries.
llvm::StringSet<> SeenNames;
/// Sets \c CurrentDirIter to the next iterator in the list, or leaves it as
/// is (at its end position) if we've already gone through them all.
std::error_code incrementIter(bool IsFirstTime) {
while (!IterList.empty()) {
CurrentDirIter = IterList.back();
IterList.pop_back();
if (CurrentDirIter != directory_iterator())
break; // found
}
if (IsFirstTime && CurrentDirIter == directory_iterator())
return errc::no_such_file_or_directory;
return {};
}
std::error_code incrementDirIter(bool IsFirstTime) {
assert((IsFirstTime || CurrentDirIter != directory_iterator()) &&
"incrementing past end");
std::error_code EC;
if (!IsFirstTime)
CurrentDirIter.increment(EC);
if (!EC && CurrentDirIter == directory_iterator())
EC = incrementIter(IsFirstTime);
return EC;
}
std::error_code incrementImpl(bool IsFirstTime) {
while (true) {
std::error_code EC = incrementDirIter(IsFirstTime);
if (EC || CurrentDirIter == directory_iterator()) {
CurrentEntry = directory_entry();
return EC;
}
CurrentEntry = *CurrentDirIter;
StringRef Name = llvm::sys::path::filename(CurrentEntry.path());
if (SeenNames.insert(Name).second)
return EC; // name not seen before
}
llvm_unreachable("returned above");
}
public:
CombiningDirIterImpl(ArrayRef<FileSystemPtr> FileSystems, std::string Dir,
std::error_code &EC) {
for (const auto &FS : FileSystems) {
std::error_code FEC;
directory_iterator Iter = FS->dir_begin(Dir, FEC);
if (FEC && FEC != errc::no_such_file_or_directory) {
EC = FEC;
return;
}
if (!FEC)
IterList.push_back(Iter);
}
EC = incrementImpl(true);
}
CombiningDirIterImpl(ArrayRef<directory_iterator> DirIters,
std::error_code &EC)
: IterList(DirIters.begin(), DirIters.end()) {
EC = incrementImpl(true);
}
std::error_code increment() override { return incrementImpl(false); }
};
} // namespace
directory_iterator OverlayFileSystem::dir_begin(const Twine &Dir,
std::error_code &EC) {
directory_iterator Combined = directory_iterator(
std::make_shared<CombiningDirIterImpl>(FSList, Dir.str(), EC));
if (EC)
return {};
return Combined;
}
void ProxyFileSystem::anchor() {}
namespace llvm {
namespace vfs {
namespace detail {
enum InMemoryNodeKind {
IME_File,
IME_Directory,
IME_HardLink,
IME_SymbolicLink,
};
/// The in memory file system is a tree of Nodes. Every node can either be a
/// file, symlink, hardlink or a directory.
class InMemoryNode {
InMemoryNodeKind Kind;
std::string FileName;
public:
InMemoryNode(llvm::StringRef FileName, InMemoryNodeKind Kind)
: Kind(Kind), FileName(std::string(llvm::sys::path::filename(FileName))) {
}
virtual ~InMemoryNode() = default;
/// Return the \p Status for this node. \p RequestedName should be the name
/// through which the caller referred to this node. It will override
/// \p Status::Name in the return value, to mimic the behavior of \p RealFile.
virtual Status getStatus(const Twine &RequestedName) const = 0;
/// Get the filename of this node (the name without the directory part).
StringRef getFileName() const { return FileName; }
InMemoryNodeKind getKind() const { return Kind; }
virtual std::string toString(unsigned Indent) const = 0;
};
class InMemoryFile : public InMemoryNode {
Status Stat;
std::unique_ptr<llvm::MemoryBuffer> Buffer;
public:
InMemoryFile(Status Stat, std::unique_ptr<llvm::MemoryBuffer> Buffer)
: InMemoryNode(Stat.getName(), IME_File), Stat(std::move(Stat)),
Buffer(std::move(Buffer)) {}
Status getStatus(const Twine &RequestedName) const override {
return Status::copyWithNewName(Stat, RequestedName);
}
llvm::MemoryBuffer *getBuffer() const { return Buffer.get(); }
std::string toString(unsigned Indent) const override {
return (std::string(Indent, ' ') + Stat.getName() + "\n").str();
}
static bool classof(const InMemoryNode *N) {
return N->getKind() == IME_File;
}
};
namespace {
class InMemoryHardLink : public InMemoryNode {
const InMemoryFile &ResolvedFile;
public:
InMemoryHardLink(StringRef Path, const InMemoryFile &ResolvedFile)
: InMemoryNode(Path, IME_HardLink), ResolvedFile(ResolvedFile) {}
const InMemoryFile &getResolvedFile() const { return ResolvedFile; }
Status getStatus(const Twine &RequestedName) const override {
return ResolvedFile.getStatus(RequestedName);
}
std::string toString(unsigned Indent) const override {
return std::string(Indent, ' ') + "HardLink to -> " +
ResolvedFile.toString(0);
}
static bool classof(const InMemoryNode *N) {
return N->getKind() == IME_HardLink;
}
};
class InMemorySymbolicLink : public InMemoryNode {
std::string TargetPath;
Status Stat;
public:
InMemorySymbolicLink(StringRef Path, StringRef TargetPath, Status Stat)
: InMemoryNode(Path, IME_SymbolicLink), TargetPath(std::move(TargetPath)),
Stat(Stat) {}
std::string toString(unsigned Indent) const override {
return std::string(Indent, ' ') + "SymbolicLink to -> " + TargetPath;
}
Status getStatus(const Twine &RequestedName) const override {
return Status::copyWithNewName(Stat, RequestedName);
}
StringRef getTargetPath() const { return TargetPath; }
static bool classof(const InMemoryNode *N) {
return N->getKind() == IME_SymbolicLink;
}
};
/// Adapt a InMemoryFile for VFS' File interface. The goal is to make
/// \p InMemoryFileAdaptor mimic as much as possible the behavior of
/// \p RealFile.
class InMemoryFileAdaptor : public File {
const InMemoryFile &Node;
/// The name to use when returning a Status for this file.
std::string RequestedName;
public:
explicit InMemoryFileAdaptor(const InMemoryFile &Node,
std::string RequestedName)
: Node(Node), RequestedName(std::move(RequestedName)) {}
llvm::ErrorOr<Status> status() override {
return Node.getStatus(RequestedName);
}
llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
getBuffer(const Twine &Name, int64_t FileSize, bool RequiresNullTerminator,
bool IsVolatile) override {
llvm::MemoryBuffer *Buf = Node.getBuffer();
return llvm::MemoryBuffer::getMemBuffer(
Buf->getBuffer(), Buf->getBufferIdentifier(), RequiresNullTerminator);
}
std::error_code close() override { return {}; }
void setPath(const Twine &Path) override { RequestedName = Path.str(); }
};
} // namespace
class InMemoryDirectory : public InMemoryNode {
Status Stat;
std::map<std::string, std::unique_ptr<InMemoryNode>> Entries;
public:
InMemoryDirectory(Status Stat)
: InMemoryNode(Stat.getName(), IME_Directory), Stat(std::move(Stat)) {}
/// Return the \p Status for this node. \p RequestedName should be the name
/// through which the caller referred to this node. It will override
/// \p Status::Name in the return value, to mimic the behavior of \p RealFile.
Status getStatus(const Twine &RequestedName) const override {
return Status::copyWithNewName(Stat, RequestedName);
}
UniqueID getUniqueID() const { return Stat.getUniqueID(); }
InMemoryNode *getChild(StringRef Name) const {
auto I = Entries.find(Name.str());
if (I != Entries.end())
return I->second.get();
return nullptr;
}
InMemoryNode *addChild(StringRef Name, std::unique_ptr<InMemoryNode> Child) {
return Entries.emplace(Name, std::move(Child)).first->second.get();
}
using const_iterator = decltype(Entries)::const_iterator;
const_iterator begin() const { return Entries.begin(); }
const_iterator end() const { return Entries.end(); }
std::string toString(unsigned Indent) const override {
std::string Result =
(std::string(Indent, ' ') + Stat.getName() + "\n").str();
for (const auto &Entry : Entries)
Result += Entry.second->toString(Indent + 2);
return Result;
}
static bool classof(const InMemoryNode *N) {
return N->getKind() == IME_Directory;
}
};
} // namespace detail
// The UniqueID of in-memory files is derived from path and content.
// This avoids difficulties in creating exactly equivalent in-memory FSes,
// as often needed in multithreaded programs.
static sys::fs::UniqueID getUniqueID(hash_code Hash) {
return sys::fs::UniqueID(std::numeric_limits<uint64_t>::max(),
uint64_t(size_t(Hash)));
}
static sys::fs::UniqueID getFileID(sys::fs::UniqueID Parent,
llvm::StringRef Name,
llvm::StringRef Contents) {
return getUniqueID(llvm::hash_combine(Parent.getFile(), Name, Contents));
}
static sys::fs::UniqueID getDirectoryID(sys::fs::UniqueID Parent,
llvm::StringRef Name) {
return getUniqueID(llvm::hash_combine(Parent.getFile(), Name));
}
Status detail::NewInMemoryNodeInfo::makeStatus() const {
UniqueID UID =
(Type == sys::fs::file_type::directory_file)
? getDirectoryID(DirUID, Name)
: getFileID(DirUID, Name, Buffer ? Buffer->getBuffer() : "");
return Status(Path, UID, llvm::sys::toTimePoint(ModificationTime), User,
Group, Buffer ? Buffer->getBufferSize() : 0, Type, Perms);
}
InMemoryFileSystem::InMemoryFileSystem(bool UseNormalizedPaths)
: Root(new detail::InMemoryDirectory(
Status("", getDirectoryID(llvm::sys::fs::UniqueID(), ""),
llvm::sys::TimePoint<>(), 0, 0, 0,
llvm::sys::fs::file_type::directory_file,
llvm::sys::fs::perms::all_all))),
UseNormalizedPaths(UseNormalizedPaths) {}
InMemoryFileSystem::~InMemoryFileSystem() = default;
std::string InMemoryFileSystem::toString() const {
return Root->toString(/*Indent=*/0);
}
bool InMemoryFileSystem::addFile(const Twine &P, time_t ModificationTime,
std::unique_ptr<llvm::MemoryBuffer> Buffer,
std::optional<uint32_t> User,
std::optional<uint32_t> Group,
std::optional<llvm::sys::fs::file_type> Type,
std::optional<llvm::sys::fs::perms> Perms,
MakeNodeFn MakeNode) {
SmallString<128> Path;
P.toVector(Path);
// Fix up relative paths. This just prepends the current working directory.
std::error_code EC = makeAbsolute(Path);
assert(!EC);
(void)EC;
if (useNormalizedPaths())
llvm::sys::path::remove_dots(Path, /*remove_dot_dot=*/true);
if (Path.empty())
return false;
detail::InMemoryDirectory *Dir = Root.get();
auto I = llvm::sys::path::begin(Path), E = sys::path::end(Path);
const auto ResolvedUser = User.value_or(0);
const auto ResolvedGroup = Group.value_or(0);
const auto ResolvedType = Type.value_or(sys::fs::file_type::regular_file);
const auto ResolvedPerms = Perms.value_or(sys::fs::all_all);
// Any intermediate directories we create should be accessible by
// the owner, even if Perms says otherwise for the final path.
const auto NewDirectoryPerms = ResolvedPerms | sys::fs::owner_all;
while (true) {
StringRef Name = *I;
detail::InMemoryNode *Node = Dir->getChild(Name);
++I;
if (!Node) {
if (I == E) {
// End of the path.
Dir->addChild(
Name, MakeNode({Dir->getUniqueID(), Path, Name, ModificationTime,
std::move(Buffer), ResolvedUser, ResolvedGroup,
ResolvedType, ResolvedPerms}));
return true;
}
// Create a new directory. Use the path up to here.
Status Stat(
StringRef(Path.str().begin(), Name.end() - Path.str().begin()),
getDirectoryID(Dir->getUniqueID(), Name),
llvm::sys::toTimePoint(ModificationTime), ResolvedUser, ResolvedGroup,
0, sys::fs::file_type::directory_file, NewDirectoryPerms);
Dir = cast<detail::InMemoryDirectory>(Dir->addChild(
Name, std::make_unique<detail::InMemoryDirectory>(std::move(Stat))));
continue;
}
if (auto *NewDir = dyn_cast<detail::InMemoryDirectory>(Node)) {
Dir = NewDir;
} else {
assert((isa<detail::InMemoryFile>(Node) ||
isa<detail::InMemoryHardLink>(Node)) &&
"Must be either file, hardlink or directory!");
// Trying to insert a directory in place of a file.
if (I != E)
return false;
// Return false only if the new file is different from the existing one.
if (auto Link = dyn_cast<detail::InMemoryHardLink>(Node)) {
return Link->getResolvedFile().getBuffer()->getBuffer() ==
Buffer->getBuffer();
}
return cast<detail::InMemoryFile>(Node)->getBuffer()->getBuffer() ==
Buffer->getBuffer();
}
}
}
bool InMemoryFileSystem::addFile(const Twine &P, time_t ModificationTime,
std::unique_ptr<llvm::MemoryBuffer> Buffer,
std::optional<uint32_t> User,
std::optional<uint32_t> Group,
std::optional<llvm::sys::fs::file_type> Type,
std::optional<llvm::sys::fs::perms> Perms) {
return addFile(P, ModificationTime, std::move(Buffer), User, Group, Type,
Perms,
[](detail::NewInMemoryNodeInfo NNI)
-> std::unique_ptr<detail::InMemoryNode> {
Status Stat = NNI.makeStatus();
if (Stat.getType() == sys::fs::file_type::directory_file)
return std::make_unique<detail::InMemoryDirectory>(Stat);
return std::make_unique<detail::InMemoryFile>(
Stat, std::move(NNI.Buffer));
});
}
bool InMemoryFileSystem::addFileNoOwn(
const Twine &P, time_t ModificationTime,
const llvm::MemoryBufferRef &Buffer, std::optional<uint32_t> User,
std::optional<uint32_t> Group, std::optional<llvm::sys::fs::file_type> Type,
std::optional<llvm::sys::fs::perms> Perms) {
return addFile(P, ModificationTime, llvm::MemoryBuffer::getMemBuffer(Buffer),
std::move(User), std::move(Group), std::move(Type),
std::move(Perms),
[](detail::NewInMemoryNodeInfo NNI)
-> std::unique_ptr<detail::InMemoryNode> {
Status Stat = NNI.makeStatus();
if (Stat.getType() == sys::fs::file_type::directory_file)
return std::make_unique<detail::InMemoryDirectory>(Stat);
return std::make_unique<detail::InMemoryFile>(
Stat, std::move(NNI.Buffer));
});
}
detail::NamedNodeOrError
InMemoryFileSystem::lookupNode(const Twine &P, bool FollowFinalSymlink,
size_t SymlinkDepth) const {
SmallString<128> Path;
P.toVector(Path);
// Fix up relative paths. This just prepends the current working directory.
std::error_code EC = makeAbsolute(Path);
assert(!EC);
(void)EC;
if (useNormalizedPaths())
llvm::sys::path::remove_dots(Path, /*remove_dot_dot=*/true);
const detail::InMemoryDirectory *Dir = Root.get();
if (Path.empty())
return detail::NamedNodeOrError(Path, Dir);
auto I = llvm::sys::path::begin(Path), E = llvm::sys::path::end(Path);
while (true) {
detail::InMemoryNode *Node = Dir->getChild(*I);
++I;
if (!Node)
return errc::no_such_file_or_directory;
if (auto Symlink = dyn_cast<detail::InMemorySymbolicLink>(Node)) {
// If we're at the end of the path, and we're not following through
// terminal symlinks, then we're done.
if (I == E && !FollowFinalSymlink)
return detail::NamedNodeOrError(Path, Symlink);
if (SymlinkDepth > InMemoryFileSystem::MaxSymlinkDepth)
return errc::no_such_file_or_directory;
SmallString<128> TargetPath = Symlink->getTargetPath();
if (std::error_code EC = makeAbsolute(TargetPath))
return EC;
// Keep going with the target. We always want to follow symlinks here
// because we're either at the end of a path that we want to follow, or
// not at the end of a path, in which case we need to follow the symlink
// regardless.
auto Target =
lookupNode(TargetPath, /*FollowFinalSymlink=*/true, SymlinkDepth + 1);
if (!Target || I == E)
return Target;
if (!isa<detail::InMemoryDirectory>(*Target))
return errc::no_such_file_or_directory;
// Otherwise, continue on the search in the symlinked directory.
Dir = cast<detail::InMemoryDirectory>(*Target);
continue;
}
// Return the file if it's at the end of the path.
if (auto File = dyn_cast<detail::InMemoryFile>(Node)) {
if (I == E)
return detail::NamedNodeOrError(Path, File);
return errc::no_such_file_or_directory;
}
// If Node is HardLink then return the resolved file.
if (auto File = dyn_cast<detail::InMemoryHardLink>(Node)) {
if (I == E)
return detail::NamedNodeOrError(Path, &File->getResolvedFile());
return errc::no_such_file_or_directory;
}
// Traverse directories.
Dir = cast<detail::InMemoryDirectory>(Node);
if (I == E)
return detail::NamedNodeOrError(Path, Dir);
}
}
bool InMemoryFileSystem::addHardLink(const Twine &NewLink,
const Twine &Target) {
auto NewLinkNode = lookupNode(NewLink, /*FollowFinalSymlink=*/false);
// Whether symlinks in the hardlink target are followed is
// implementation-defined in POSIX.
// We're following symlinks here to be consistent with macOS.
auto TargetNode = lookupNode(Target, /*FollowFinalSymlink=*/true);
// FromPath must not have been added before. ToPath must have been added
// before. Resolved ToPath must be a File.
if (!TargetNode || NewLinkNode || !isa<detail::InMemoryFile>(*TargetNode))
return false;
return addFile(NewLink, 0, nullptr, std::nullopt, std::nullopt, std::nullopt,
std::nullopt, [&](detail::NewInMemoryNodeInfo NNI) {
return std::make_unique<detail::InMemoryHardLink>(
NNI.Path.str(),
*cast<detail::InMemoryFile>(*TargetNode));
});
}
bool InMemoryFileSystem::addSymbolicLink(
const Twine &NewLink, const Twine &Target, time_t ModificationTime,
std::optional<uint32_t> User, std::optional<uint32_t> Group,
std::optional<llvm::sys::fs::perms> Perms) {
auto NewLinkNode = lookupNode(NewLink, /*FollowFinalSymlink=*/false);
if (NewLinkNode)
return false;
SmallString<128> NewLinkStr, TargetStr;
NewLink.toVector(NewLinkStr);
Target.toVector(TargetStr);
return addFile(NewLinkStr, ModificationTime, nullptr, User, Group,
sys::fs::file_type::symlink_file, Perms,
[&](detail::NewInMemoryNodeInfo NNI) {
return std::make_unique<detail::InMemorySymbolicLink>(
NewLinkStr, TargetStr, NNI.makeStatus());
});
}
llvm::ErrorOr<Status> InMemoryFileSystem::status(const Twine &Path) {
auto Node = lookupNode(Path, /*FollowFinalSymlink=*/true);
if (Node)
return (*Node)->getStatus(Path);
return Node.getError();
}
llvm::ErrorOr<std::unique_ptr<File>>
InMemoryFileSystem::openFileForRead(const Twine &Path) {
auto Node = lookupNode(Path,/*FollowFinalSymlink=*/true);
if (!Node)
return Node.getError();
// When we have a file provide a heap-allocated wrapper for the memory buffer
// to match the ownership semantics for File.
if (auto *F = dyn_cast<detail::InMemoryFile>(*Node))
return std::unique_ptr<File>(
new detail::InMemoryFileAdaptor(*F, Path.str()));
// FIXME: errc::not_a_file?
return make_error_code(llvm::errc::invalid_argument);
}
/// Adaptor from InMemoryDir::iterator to directory_iterator.
class InMemoryFileSystem::DirIterator : public llvm::vfs::detail::DirIterImpl {
const InMemoryFileSystem *FS;
detail::InMemoryDirectory::const_iterator I;
detail::InMemoryDirectory::const_iterator E;
std::string RequestedDirName;
void setCurrentEntry() {
if (I != E) {
SmallString<256> Path(RequestedDirName);
llvm::sys::path::append(Path, I->second->getFileName());
sys::fs::file_type Type = sys::fs::file_type::type_unknown;
switch (I->second->getKind()) {
case detail::IME_File:
case detail::IME_HardLink:
Type = sys::fs::file_type::regular_file;
break;
case detail::IME_Directory:
Type = sys::fs::file_type::directory_file;
break;
case detail::IME_SymbolicLink:
if (auto SymlinkTarget =
FS->lookupNode(Path, /*FollowFinalSymlink=*/true)) {
Path = SymlinkTarget.getName();
Type = (*SymlinkTarget)->getStatus(Path).getType();
}
break;
}
CurrentEntry = directory_entry(std::string(Path), Type);
} else {
// When we're at the end, make CurrentEntry invalid and DirIterImpl will
// do the rest.
CurrentEntry = directory_entry();
}
}
public:
DirIterator() = default;
DirIterator(const InMemoryFileSystem *FS,
const detail::InMemoryDirectory &Dir,
std::string RequestedDirName)
: FS(FS), I(Dir.begin()), E(Dir.end()),
RequestedDirName(std::move(RequestedDirName)) {
setCurrentEntry();
}
std::error_code increment() override {
++I;
setCurrentEntry();
return {};
}
};
directory_iterator InMemoryFileSystem::dir_begin(const Twine &Dir,
std::error_code &EC) {
auto Node = lookupNode(Dir, /*FollowFinalSymlink=*/true);
if (!Node) {
EC = Node.getError();
return directory_iterator(std::make_shared<DirIterator>());
}
if (auto *DirNode = dyn_cast<detail::InMemoryDirectory>(*Node))
return directory_iterator(
std::make_shared<DirIterator>(this, *DirNode, Dir.str()));
EC = make_error_code(llvm::errc::not_a_directory);
return directory_iterator(std::make_shared<DirIterator>());
}
std::error_code InMemoryFileSystem::setCurrentWorkingDirectory(const Twine &P) {
SmallString<128> Path;
P.toVector(Path);
// Fix up relative paths. This just prepends the current working directory.
std::error_code EC = makeAbsolute(Path);
assert(!EC);
(void)EC;
if (useNormalizedPaths())
llvm::sys::path::remove_dots(Path, /*remove_dot_dot=*/true);
if (!Path.empty())
WorkingDirectory = std::string(Path);
return {};
}
std::error_code InMemoryFileSystem::getRealPath(const Twine &Path,
SmallVectorImpl<char> &Output) {
auto CWD = getCurrentWorkingDirectory();
if (!CWD || CWD->empty())
return errc::operation_not_permitted;
Path.toVector(Output);
if (auto EC = makeAbsolute(Output))
return EC;
llvm::sys::path::remove_dots(Output, /*remove_dot_dot=*/true);
return {};
}
std::error_code InMemoryFileSystem::isLocal(const Twine &Path, bool &Result) {
Result = false;
return {};
}
void InMemoryFileSystem::printImpl(raw_ostream &OS, PrintType PrintContents,
unsigned IndentLevel) const {
printIndent(OS, IndentLevel);
OS << "InMemoryFileSystem\n";
}
} // namespace vfs
} // namespace llvm
//===-----------------------------------------------------------------------===/
// RedirectingFileSystem implementation
//===-----------------------------------------------------------------------===/
namespace {
static llvm::sys::path::Style getExistingStyle(llvm::StringRef Path) {
// Detect the path style in use by checking the first separator.
llvm::sys::path::Style style = llvm::sys::path::Style::native;
const size_t n = Path.find_first_of("/\\");
// Can't distinguish between posix and windows_slash here.
if (n != static_cast<size_t>(-1))
style = (Path[n] == '/') ? llvm::sys::path::Style::posix
: llvm::sys::path::Style::windows_backslash;
return style;
}
/// Removes leading "./" as well as path components like ".." and ".".
static llvm::SmallString<256> canonicalize(llvm::StringRef Path) {
// First detect the path style in use by checking the first separator.
llvm::sys::path::Style style = getExistingStyle(Path);
// Now remove the dots. Explicitly specifying the path style prevents the
// direction of the slashes from changing.
llvm::SmallString<256> result =
llvm::sys::path::remove_leading_dotslash(Path, style);
llvm::sys::path::remove_dots(result, /*remove_dot_dot=*/true, style);
return result;
}
/// Whether the error and entry specify a file/directory that was not found.
static bool isFileNotFound(std::error_code EC,
RedirectingFileSystem::Entry *E = nullptr) {
if (E && !isa<RedirectingFileSystem::DirectoryRemapEntry>(E))
return false;
return EC == llvm::errc::no_such_file_or_directory;
}
} // anonymous namespace
RedirectingFileSystem::RedirectingFileSystem(IntrusiveRefCntPtr<FileSystem> FS)
: ExternalFS(std::move(FS)) {
if (ExternalFS)
if (auto ExternalWorkingDirectory =
ExternalFS->getCurrentWorkingDirectory()) {
WorkingDirectory = *ExternalWorkingDirectory;
}
}
/// Directory iterator implementation for \c RedirectingFileSystem's
/// directory entries.
class llvm::vfs::RedirectingFSDirIterImpl
: public llvm::vfs::detail::DirIterImpl {
std::string Dir;
RedirectingFileSystem::DirectoryEntry::iterator Current, End;
std::error_code incrementImpl(bool IsFirstTime) {
assert((IsFirstTime || Current != End) && "cannot iterate past end");
if (!IsFirstTime)
++Current;
if (Current != End) {
SmallString<128> PathStr(Dir);
llvm::sys::path::append(PathStr, (*Current)->getName());
sys::fs::file_type Type = sys::fs::file_type::type_unknown;
switch ((*Current)->getKind()) {
case RedirectingFileSystem::EK_Directory:
[[fallthrough]];
case RedirectingFileSystem::EK_DirectoryRemap:
Type = sys::fs::file_type::directory_file;
break;
case RedirectingFileSystem::EK_File:
Type = sys::fs::file_type::regular_file;
break;
}
CurrentEntry = directory_entry(std::string(PathStr), Type);
} else {
CurrentEntry = directory_entry();
}
return {};
};
public:
RedirectingFSDirIterImpl(
const Twine &Path, RedirectingFileSystem::DirectoryEntry::iterator Begin,
RedirectingFileSystem::DirectoryEntry::iterator End, std::error_code &EC)
: Dir(Path.str()), Current(Begin), End(End) {
EC = incrementImpl(/*IsFirstTime=*/true);
}
std::error_code increment() override {
return incrementImpl(/*IsFirstTime=*/false);
}
};
namespace {
/// Directory iterator implementation for \c RedirectingFileSystem's
/// directory remap entries that maps the paths reported by the external
/// file system's directory iterator back to the virtual directory's path.
class RedirectingFSDirRemapIterImpl : public llvm::vfs::detail::DirIterImpl {
std::string Dir;
llvm::sys::path::Style DirStyle;
llvm::vfs::directory_iterator ExternalIter;
public:
RedirectingFSDirRemapIterImpl(std::string DirPath,
llvm::vfs::directory_iterator ExtIter)
: Dir(std::move(DirPath)), DirStyle(getExistingStyle(Dir)),
ExternalIter(ExtIter) {
if (ExternalIter != llvm::vfs::directory_iterator())
setCurrentEntry();
}
void setCurrentEntry() {
StringRef ExternalPath = ExternalIter->path();
llvm::sys::path::Style ExternalStyle = getExistingStyle(ExternalPath);
StringRef File = llvm::sys::path::filename(ExternalPath, ExternalStyle);
SmallString<128> NewPath(Dir);
llvm::sys::path::append(NewPath, DirStyle, File);
CurrentEntry = directory_entry(std::string(NewPath), ExternalIter->type());
}
std::error_code increment() override {
std::error_code EC;
ExternalIter.increment(EC);
if (!EC && ExternalIter != llvm::vfs::directory_iterator())
setCurrentEntry();
else
CurrentEntry = directory_entry();
return EC;
}
};
} // namespace
llvm::ErrorOr<std::string>
RedirectingFileSystem::getCurrentWorkingDirectory() const {
return WorkingDirectory;
}
std::error_code
RedirectingFileSystem::setCurrentWorkingDirectory(const Twine &Path) {
// Don't change the working directory if the path doesn't exist.
if (!exists(Path))
return errc::no_such_file_or_directory;
SmallString<128> AbsolutePath;
Path.toVector(AbsolutePath);
if (std::error_code EC = makeAbsolute(AbsolutePath))
return EC;
WorkingDirectory = std::string(AbsolutePath);
return {};
}
std::error_code RedirectingFileSystem::isLocal(const Twine &Path_,
bool &Result) {
SmallString<256> Path;
Path_.toVector(Path);
if (makeAbsolute(Path))
return {};
return ExternalFS->isLocal(Path, Result);
}
std::error_code RedirectingFileSystem::makeAbsolute(SmallVectorImpl<char> &Path) const {
// is_absolute(..., Style::windows_*) accepts paths with both slash types.
if (llvm::sys::path::is_absolute(Path, llvm::sys::path::Style::posix) ||
llvm::sys::path::is_absolute(Path,
llvm::sys::path::Style::windows_backslash))
// This covers windows absolute path with forward slash as well, as the
// forward slashes are treated as path seperation in llvm::path
// regardless of what path::Style is used.
return {};
auto WorkingDir = getCurrentWorkingDirectory();
if (!WorkingDir)
return WorkingDir.getError();
return makeAbsolute(WorkingDir.get(), Path);
}
std::error_code
RedirectingFileSystem::makeAbsolute(StringRef WorkingDir,
SmallVectorImpl<char> &Path) const {
// We can't use sys::fs::make_absolute because that assumes the path style
// is native and there is no way to override that. Since we know WorkingDir
// is absolute, we can use it to determine which style we actually have and
// append Path ourselves.
if (!WorkingDir.empty() &&
!sys::path::is_absolute(WorkingDir, sys::path::Style::posix) &&
!sys::path::is_absolute(WorkingDir,
sys::path::Style::windows_backslash)) {
return std::error_code();
}
sys::path::Style style = sys::path::Style::windows_backslash;
if (sys::path::is_absolute(WorkingDir, sys::path::Style::posix)) {
style = sys::path::Style::posix;
} else {
// Distinguish between windows_backslash and windows_slash; getExistingStyle
// returns posix for a path with windows_slash.
if (getExistingStyle(WorkingDir) != sys::path::Style::windows_backslash)
style = sys::path::Style::windows_slash;
}
std::string Result = std::string(WorkingDir);
StringRef Dir(Result);
if (!Dir.ends_with(sys::path::get_separator(style))) {
Result += sys::path::get_separator(style);
}
// backslashes '\' are legit path charactors under POSIX. Windows APIs
// like CreateFile accepts forward slashes '/' as path
// separator (even when mixed with backslashes). Therefore,
// `Path` should be directly appended to `WorkingDir` without converting
// path separator.
Result.append(Path.data(), Path.size());
Path.assign(Result.begin(), Result.end());
return {};
}
directory_iterator RedirectingFileSystem::dir_begin(const Twine &Dir,
std::error_code &EC) {
SmallString<256> Path;
Dir.toVector(Path);
EC = makeAbsolute(Path);
if (EC)
return {};
ErrorOr<RedirectingFileSystem::LookupResult> Result = lookupPath(Path);
if (!Result) {
if (Redirection != RedirectKind::RedirectOnly &&
isFileNotFound(Result.getError()))
return ExternalFS->dir_begin(Path, EC);
EC = Result.getError();
return {};
}
// Use status to make sure the path exists and refers to a directory.
ErrorOr<Status> S = status(Path, Dir, *Result);
if (!S) {
if (Redirection != RedirectKind::RedirectOnly &&
isFileNotFound(S.getError(), Result->E))
return ExternalFS->dir_begin(Dir, EC);
EC = S.getError();
return {};
}
if (!S->isDirectory()) {
EC = errc::not_a_directory;
return {};
}
// Create the appropriate directory iterator based on whether we found a
// DirectoryRemapEntry or DirectoryEntry.
directory_iterator RedirectIter;
std::error_code RedirectEC;
if (auto ExtRedirect = Result->getExternalRedirect()) {
auto RE = cast<RedirectingFileSystem::RemapEntry>(Result->E);
RedirectIter = ExternalFS->dir_begin(*ExtRedirect, RedirectEC);
if (!RE->useExternalName(UseExternalNames)) {
// Update the paths in the results to use the virtual directory's path.
RedirectIter =
directory_iterator(std::make_shared<RedirectingFSDirRemapIterImpl>(
std::string(Path), RedirectIter));
}
} else {
auto DE = cast<DirectoryEntry>(Result->E);
RedirectIter =
directory_iterator(std::make_shared<RedirectingFSDirIterImpl>(
Path, DE->contents_begin(), DE->contents_end(), RedirectEC));
}
if (RedirectEC) {
if (RedirectEC != errc::no_such_file_or_directory) {
EC = RedirectEC;
return {};
}
RedirectIter = {};
}
if (Redirection == RedirectKind::RedirectOnly) {
EC = RedirectEC;
return RedirectIter;
}
std::error_code ExternalEC;
directory_iterator ExternalIter = ExternalFS->dir_begin(Path, ExternalEC);
if (ExternalEC) {
if (ExternalEC != errc::no_such_file_or_directory) {
EC = ExternalEC;
return {};
}
ExternalIter = {};
}
SmallVector<directory_iterator, 2> Iters;
switch (Redirection) {
case RedirectKind::Fallthrough:
Iters.push_back(ExternalIter);
Iters.push_back(RedirectIter);
break;
case RedirectKind::Fallback:
Iters.push_back(RedirectIter);
Iters.push_back(ExternalIter);
break;
default:
llvm_unreachable("unhandled RedirectKind");
}
directory_iterator Combined{
std::make_shared<CombiningDirIterImpl>(Iters, EC)};
if (EC)
return {};
return Combined;
}
void RedirectingFileSystem::setOverlayFileDir(StringRef Dir) {
OverlayFileDir = Dir.str();
}
StringRef RedirectingFileSystem::getOverlayFileDir() const {
return OverlayFileDir;
}
void RedirectingFileSystem::setFallthrough(bool Fallthrough) {
if (Fallthrough) {
Redirection = RedirectingFileSystem::RedirectKind::Fallthrough;
} else {
Redirection = RedirectingFileSystem::RedirectKind::RedirectOnly;
}
}
void RedirectingFileSystem::setRedirection(
RedirectingFileSystem::RedirectKind Kind) {
Redirection = Kind;
}
std::vector<StringRef> RedirectingFileSystem::getRoots() const {
std::vector<StringRef> R;
R.reserve(Roots.size());
for (const auto &Root : Roots)
R.push_back(Root->getName());
return R;
}
void RedirectingFileSystem::printImpl(raw_ostream &OS, PrintType Type,
unsigned IndentLevel) const {
printIndent(OS, IndentLevel);
OS << "RedirectingFileSystem (UseExternalNames: "
<< (UseExternalNames ? "true" : "false") << ")\n";
if (Type == PrintType::Summary)
return;
for (const auto &Root : Roots)
printEntry(OS, Root.get(), IndentLevel);
printIndent(OS, IndentLevel);
OS << "ExternalFS:\n";
ExternalFS->print(OS, Type == PrintType::Contents ? PrintType::Summary : Type,
IndentLevel + 1);
}
void RedirectingFileSystem::printEntry(raw_ostream &OS,
RedirectingFileSystem::Entry *E,
unsigned IndentLevel) const {
printIndent(OS, IndentLevel);
OS << "'" << E->getName() << "'";
switch (E->getKind()) {
case EK_Directory: {
auto *DE = cast<RedirectingFileSystem::DirectoryEntry>(E);
OS << "\n";
for (std::unique_ptr<Entry> &SubEntry :
llvm::make_range(DE->contents_begin(), DE->contents_end()))
printEntry(OS, SubEntry.get(), IndentLevel + 1);
break;
}
case EK_DirectoryRemap:
case EK_File: {
auto *RE = cast<RedirectingFileSystem::RemapEntry>(E);
OS << " -> '" << RE->getExternalContentsPath() << "'";
switch (RE->getUseName()) {
case NK_NotSet:
break;
case NK_External:
OS << " (UseExternalName: true)";
break;
case NK_Virtual:
OS << " (UseExternalName: false)";
break;
}
OS << "\n";
break;
}
}
}
void RedirectingFileSystem::visitChildFileSystems(VisitCallbackTy Callback) {
if (ExternalFS) {
Callback(*ExternalFS);
ExternalFS->visitChildFileSystems(Callback);
}
}
/// A helper class to hold the common YAML parsing state.
class llvm::vfs::RedirectingFileSystemParser {
yaml::Stream &Stream;
void error(yaml::Node *N, const Twine &Msg) { Stream.printError(N, Msg); }
// false on error
bool parseScalarString(yaml::Node *N, StringRef &Result,
SmallVectorImpl<char> &Storage) {
const auto *S = dyn_cast<yaml::ScalarNode>(N);
if (!S) {
error(N, "expected string");
return false;
}
Result = S->getValue(Storage);
return true;
}
// false on error
bool parseScalarBool(yaml::Node *N, bool &Result) {
SmallString<5> Storage;
StringRef Value;
if (!parseScalarString(N, Value, Storage))
return false;
if (Value.equals_insensitive("true") || Value.equals_insensitive("on") ||
Value.equals_insensitive("yes") || Value == "1") {
Result = true;
return true;
} else if (Value.equals_insensitive("false") ||
Value.equals_insensitive("off") ||
Value.equals_insensitive("no") || Value == "0") {
Result = false;
return true;
}
error(N, "expected boolean value");
return false;
}
std::optional<RedirectingFileSystem::RedirectKind>
parseRedirectKind(yaml::Node *N) {
SmallString<12> Storage;
StringRef Value;
if (!parseScalarString(N, Value, Storage))
return std::nullopt;
if (Value.equals_insensitive("fallthrough")) {
return RedirectingFileSystem::RedirectKind::Fallthrough;
} else if (Value.equals_insensitive("fallback")) {
return RedirectingFileSystem::RedirectKind::Fallback;
} else if (Value.equals_insensitive("redirect-only")) {
return RedirectingFileSystem::RedirectKind::RedirectOnly;
}
return std::nullopt;
}
std::optional<RedirectingFileSystem::RootRelativeKind>
parseRootRelativeKind(yaml::Node *N) {
SmallString<12> Storage;
StringRef Value;
if (!parseScalarString(N, Value, Storage))
return std::nullopt;
if (Value.equals_insensitive("cwd")) {
return RedirectingFileSystem::RootRelativeKind::CWD;
} else if (Value.equals_insensitive("overlay-dir")) {
return RedirectingFileSystem::RootRelativeKind::OverlayDir;
}
return std::nullopt;
}
struct KeyStatus {
bool Required;
bool Seen = false;
KeyStatus(bool Required = false) : Required(Required) {}
};
using KeyStatusPair = std::pair<StringRef, KeyStatus>;
// false on error
bool checkDuplicateOrUnknownKey(yaml::Node *KeyNode, StringRef Key,
DenseMap<StringRef, KeyStatus> &Keys) {
if (!Keys.count(Key)) {
error(KeyNode, "unknown key");
return false;
}
KeyStatus &S = Keys[Key];
if (S.Seen) {
error(KeyNode, Twine("duplicate key '") + Key + "'");
return false;
}
S.Seen = true;
return true;
}
// false on error
bool checkMissingKeys(yaml::Node *Obj, DenseMap<StringRef, KeyStatus> &Keys) {
for (const auto &I : Keys) {
if (I.second.Required && !I.second.Seen) {
error(Obj, Twine("missing key '") + I.first + "'");
return false;
}
}
return true;
}
public:
static RedirectingFileSystem::Entry *
lookupOrCreateEntry(RedirectingFileSystem *FS, StringRef Name,
RedirectingFileSystem::Entry *ParentEntry = nullptr) {
if (!ParentEntry) { // Look for a existent root
for (const auto &Root : FS->Roots) {
if (Name.equals(Root->getName())) {
ParentEntry = Root.get();
return ParentEntry;
}
}
} else { // Advance to the next component
auto *DE = dyn_cast<RedirectingFileSystem::DirectoryEntry>(ParentEntry);
for (std::unique_ptr<RedirectingFileSystem::Entry> &Content :
llvm::make_range(DE->contents_begin(), DE->contents_end())) {
auto *DirContent =
dyn_cast<RedirectingFileSystem::DirectoryEntry>(Content.get());
if (DirContent && Name.equals(Content->getName()))
return DirContent;
}
}
// ... or create a new one
std::unique_ptr<RedirectingFileSystem::Entry> E =
std::make_unique<RedirectingFileSystem::DirectoryEntry>(
Name, Status("", getNextVirtualUniqueID(),
std::chrono::system_clock::now(), 0, 0, 0,
file_type::directory_file, sys::fs::all_all));
if (!ParentEntry) { // Add a new root to the overlay
FS->Roots.push_back(std::move(E));
ParentEntry = FS->Roots.back().get();
return ParentEntry;
}
auto *DE = cast<RedirectingFileSystem::DirectoryEntry>(ParentEntry);
DE->addContent(std::move(E));
return DE->getLastContent();
}
private:
void uniqueOverlayTree(RedirectingFileSystem *FS,
RedirectingFileSystem::Entry *SrcE,
RedirectingFileSystem::Entry *NewParentE = nullptr) {
StringRef Name = SrcE->getName();
switch (SrcE->getKind()) {
case RedirectingFileSystem::EK_Directory: {
auto *DE = cast<RedirectingFileSystem::DirectoryEntry>(SrcE);
// Empty directories could be present in the YAML as a way to
// describe a file for a current directory after some of its subdir
// is parsed. This only leads to redundant walks, ignore it.
if (!Name.empty())
NewParentE = lookupOrCreateEntry(FS, Name, NewParentE);
for (std::unique_ptr<RedirectingFileSystem::Entry> &SubEntry :
llvm::make_range(DE->contents_begin(), DE->contents_end()))
uniqueOverlayTree(FS, SubEntry.get(), NewParentE);
break;
}
case RedirectingFileSystem::EK_DirectoryRemap: {
assert(NewParentE && "Parent entry must exist");
auto *DR = cast<RedirectingFileSystem::DirectoryRemapEntry>(SrcE);
auto *DE = cast<RedirectingFileSystem::DirectoryEntry>(NewParentE);
DE->addContent(
std::make_unique<RedirectingFileSystem::DirectoryRemapEntry>(
Name, DR->getExternalContentsPath(), DR->getUseName()));
break;
}
case RedirectingFileSystem::EK_File: {
assert(NewParentE && "Parent entry must exist");
auto *FE = cast<RedirectingFileSystem::FileEntry>(SrcE);
auto *DE = cast<RedirectingFileSystem::DirectoryEntry>(NewParentE);
DE->addContent(std::make_unique<RedirectingFileSystem::FileEntry>(
Name, FE->getExternalContentsPath(), FE->getUseName()));
break;
}
}
}
std::unique_ptr<RedirectingFileSystem::Entry>
parseEntry(yaml::Node *N, RedirectingFileSystem *FS, bool IsRootEntry) {
auto *M = dyn_cast<yaml::MappingNode>(N);
if (!M) {
error(N, "expected mapping node for file or directory entry");
return nullptr;
}
KeyStatusPair Fields[] = {
KeyStatusPair("name", true),
KeyStatusPair("type", true),
KeyStatusPair("contents", false),
KeyStatusPair("external-contents", false),
KeyStatusPair("use-external-name", false),
};
DenseMap<StringRef, KeyStatus> Keys(std::begin(Fields), std::end(Fields));
enum { CF_NotSet, CF_List, CF_External } ContentsField = CF_NotSet;
std::vector<std::unique_ptr<RedirectingFileSystem::Entry>>
EntryArrayContents;
SmallString<256> ExternalContentsPath;
SmallString<256> Name;
yaml::Node *NameValueNode = nullptr;
auto UseExternalName = RedirectingFileSystem::NK_NotSet;
RedirectingFileSystem::EntryKind Kind;
for (auto &I : *M) {
StringRef Key;
// Reuse the buffer for key and value, since we don't look at key after
// parsing value.
SmallString<256> Buffer;
if (!parseScalarString(I.getKey(), Key, Buffer))
return nullptr;
if (!checkDuplicateOrUnknownKey(I.getKey(), Key, Keys))
return nullptr;
StringRef Value;
if (Key == "name") {
if (!parseScalarString(I.getValue(), Value, Buffer))
return nullptr;
NameValueNode = I.getValue();
// Guarantee that old YAML files containing paths with ".." and "."
// are properly canonicalized before read into the VFS.
Name = canonicalize(Value).str();
} else if (Key == "type") {
if (!parseScalarString(I.getValue(), Value, Buffer))
return nullptr;
if (Value == "file")
Kind = RedirectingFileSystem::EK_File;
else if (Value == "directory")
Kind = RedirectingFileSystem::EK_Directory;
else if (Value == "directory-remap")
Kind = RedirectingFileSystem::EK_DirectoryRemap;
else {
error(I.getValue(), "unknown value for 'type'");
return nullptr;
}
} else if (Key == "contents") {
if (ContentsField != CF_NotSet) {
error(I.getKey(),
"entry already has 'contents' or 'external-contents'");
return nullptr;
}
ContentsField = CF_List;
auto *Contents = dyn_cast<yaml::SequenceNode>(I.getValue());
if (!Contents) {
// FIXME: this is only for directories, what about files?
error(I.getValue(), "expected array");
return nullptr;
}
for (auto &I : *Contents) {
if (std::unique_ptr<RedirectingFileSystem::Entry> E =
parseEntry(&I, FS, /*IsRootEntry*/ false))
EntryArrayContents.push_back(std::move(E));
else
return nullptr;
}
} else if (Key == "external-contents") {
if (ContentsField != CF_NotSet) {
error(I.getKey(),
"entry already has 'contents' or 'external-contents'");
return nullptr;
}
ContentsField = CF_External;
if (!parseScalarString(I.getValue(), Value, Buffer))
return nullptr;
SmallString<256> FullPath;
if (FS->IsRelativeOverlay) {
FullPath = FS->getOverlayFileDir();
assert(!FullPath.empty() &&
"External contents prefix directory must exist");
llvm::sys::path::append(FullPath, Value);
} else {
FullPath = Value;
}
// Guarantee that old YAML files containing paths with ".." and "."
// are properly canonicalized before read into the VFS.
FullPath = canonicalize(FullPath);
ExternalContentsPath = FullPath.str();
} else if (Key == "use-external-name") {
bool Val;
if (!parseScalarBool(I.getValue(), Val))
return nullptr;
UseExternalName = Val ? RedirectingFileSystem::NK_External
: RedirectingFileSystem::NK_Virtual;
} else {
llvm_unreachable("key missing from Keys");
}
}
if (Stream.failed())
return nullptr;
// check for missing keys
if (ContentsField == CF_NotSet) {
error(N, "missing key 'contents' or 'external-contents'");
return nullptr;
}
if (!checkMissingKeys(N, Keys))
return nullptr;
// check invalid configuration
if (Kind == RedirectingFileSystem::EK_Directory &&
UseExternalName != RedirectingFileSystem::NK_NotSet) {
error(N, "'use-external-name' is not supported for 'directory' entries");
return nullptr;
}
if (Kind == RedirectingFileSystem::EK_DirectoryRemap &&
ContentsField == CF_List) {
error(N, "'contents' is not supported for 'directory-remap' entries");
return nullptr;
}
sys::path::Style path_style = sys::path::Style::native;
if (IsRootEntry) {
// VFS root entries may be in either Posix or Windows style. Figure out
// which style we have, and use it consistently.
if (sys::path::is_absolute(Name, sys::path::Style::posix)) {
path_style = sys::path::Style::posix;
} else if (sys::path::is_absolute(Name,
sys::path::Style::windows_backslash)) {
path_style = sys::path::Style::windows_backslash;
} else {
// Relative VFS root entries are made absolute to either the overlay
// directory, or the current working directory, then we can determine
// the path style from that.
std::error_code EC;
if (FS->RootRelative ==
RedirectingFileSystem::RootRelativeKind::OverlayDir) {
StringRef FullPath = FS->getOverlayFileDir();
assert(!FullPath.empty() && "Overlay file directory must exist");
EC = FS->makeAbsolute(FullPath, Name);
Name = canonicalize(Name);
} else {
EC = sys::fs::make_absolute(Name);
}
if (EC) {
assert(NameValueNode && "Name presence should be checked earlier");
error(
NameValueNode,
"entry with relative path at the root level is not discoverable");
return nullptr;
}
path_style = sys::path::is_absolute(Name, sys::path::Style::posix)
? sys::path::Style::posix
: sys::path::Style::windows_backslash;
}
// is::path::is_absolute(Name, sys::path::Style::windows_backslash) will
// return true even if `Name` is using forward slashes. Distinguish
// between windows_backslash and windows_slash.
if (path_style == sys::path::Style::windows_backslash &&
getExistingStyle(Name) != sys::path::Style::windows_backslash)
path_style = sys::path::Style::windows_slash;
}
// Remove trailing slash(es), being careful not to remove the root path
StringRef Trimmed = Name;
size_t RootPathLen = sys::path::root_path(Trimmed, path_style).size();
while (Trimmed.size() > RootPathLen &&
sys::path::is_separator(Trimmed.back(), path_style))
Trimmed = Trimmed.slice(0, Trimmed.size() - 1);
// Get the last component
StringRef LastComponent = sys::path::filename(Trimmed, path_style);
std::unique_ptr<RedirectingFileSystem::Entry> Result;
switch (Kind) {
case RedirectingFileSystem::EK_File:
Result = std::make_unique<RedirectingFileSystem::FileEntry>(
LastComponent, std::move(ExternalContentsPath), UseExternalName);
break;
case RedirectingFileSystem::EK_DirectoryRemap:
Result = std::make_unique<RedirectingFileSystem::DirectoryRemapEntry>(
LastComponent, std::move(ExternalContentsPath), UseExternalName);
break;
case RedirectingFileSystem::EK_Directory:
Result = std::make_unique<RedirectingFileSystem::DirectoryEntry>(
LastComponent, std::move(EntryArrayContents),
Status("", getNextVirtualUniqueID(), std::chrono::system_clock::now(),
0, 0, 0, file_type::directory_file, sys::fs::all_all));
break;
}
StringRef Parent = sys::path::parent_path(Trimmed, path_style);
if (Parent.empty())
return Result;
// if 'name' contains multiple components, create implicit directory entries
for (sys::path::reverse_iterator I = sys::path::rbegin(Parent, path_style),
E = sys::path::rend(Parent);
I != E; ++I) {
std::vector<std::unique_ptr<RedirectingFileSystem::Entry>> Entries;
Entries.push_back(std::move(Result));
Result = std::make_unique<RedirectingFileSystem::DirectoryEntry>(
*I, std::move(Entries),
Status("", getNextVirtualUniqueID(), std::chrono::system_clock::now(),
0, 0, 0, file_type::directory_file, sys::fs::all_all));
}
return Result;
}
public:
RedirectingFileSystemParser(yaml::Stream &S) : Stream(S) {}
// false on error
bool parse(yaml::Node *Root, RedirectingFileSystem *FS) {
auto *Top = dyn_cast<yaml::MappingNode>(Root);
if (!Top) {
error(Root, "expected mapping node");
return false;
}
KeyStatusPair Fields[] = {
KeyStatusPair("version", true),
KeyStatusPair("case-sensitive", false),
KeyStatusPair("use-external-names", false),
KeyStatusPair("root-relative", false),
KeyStatusPair("overlay-relative", false),
KeyStatusPair("fallthrough", false),
KeyStatusPair("redirecting-with", false),
KeyStatusPair("roots", true),
};
DenseMap<StringRef, KeyStatus> Keys(std::begin(Fields), std::end(Fields));
std::vector<std::unique_ptr<RedirectingFileSystem::Entry>> RootEntries;
// Parse configuration and 'roots'
for (auto &I : *Top) {
SmallString<10> KeyBuffer;
StringRef Key;
if (!parseScalarString(I.getKey(), Key, KeyBuffer))
return false;
if (!checkDuplicateOrUnknownKey(I.getKey(), Key, Keys))
return false;
if (Key == "roots") {
auto *Roots = dyn_cast<yaml::SequenceNode>(I.getValue());
if (!Roots) {
error(I.getValue(), "expected array");
return false;
}
for (auto &I : *Roots) {
if (std::unique_ptr<RedirectingFileSystem::Entry> E =
parseEntry(&I, FS, /*IsRootEntry*/ true))
RootEntries.push_back(std::move(E));
else
return false;
}
} else if (Key == "version") {
StringRef VersionString;
SmallString<4> Storage;
if (!parseScalarString(I.getValue(), VersionString, Storage))
return false;
int Version;
if (VersionString.getAsInteger<int>(10, Version)) {
error(I.getValue(), "expected integer");
return false;
}
if (Version < 0) {
error(I.getValue(), "invalid version number");
return false;
}
if (Version != 0) {
error(I.getValue(), "version mismatch, expected 0");
return false;
}
} else if (Key == "case-sensitive") {
if (!parseScalarBool(I.getValue(), FS->CaseSensitive))
return false;
} else if (Key == "overlay-relative") {
if (!parseScalarBool(I.getValue(), FS->IsRelativeOverlay))
return false;
} else if (Key == "use-external-names") {
if (!parseScalarBool(I.getValue(), FS->UseExternalNames))
return false;
} else if (Key == "fallthrough") {
if (Keys["redirecting-with"].Seen) {
error(I.getValue(),
"'fallthrough' and 'redirecting-with' are mutually exclusive");
return false;
}
bool ShouldFallthrough = false;
if (!parseScalarBool(I.getValue(), ShouldFallthrough))
return false;
if (ShouldFallthrough) {
FS->Redirection = RedirectingFileSystem::RedirectKind::Fallthrough;
} else {
FS->Redirection = RedirectingFileSystem::RedirectKind::RedirectOnly;
}
} else if (Key == "redirecting-with") {
if (Keys["fallthrough"].Seen) {
error(I.getValue(),
"'fallthrough' and 'redirecting-with' are mutually exclusive");
return false;
}
if (auto Kind = parseRedirectKind(I.getValue())) {
FS->Redirection = *Kind;
} else {
error(I.getValue(), "expected valid redirect kind");
return false;
}
} else if (Key == "root-relative") {
if (auto Kind = parseRootRelativeKind(I.getValue())) {
FS->RootRelative = *Kind;
} else {
error(I.getValue(), "expected valid root-relative kind");
return false;
}
} else {
llvm_unreachable("key missing from Keys");
}
}
if (Stream.failed())
return false;
if (!checkMissingKeys(Top, Keys))
return false;
// Now that we sucessefully parsed the YAML file, canonicalize the internal
// representation to a proper directory tree so that we can search faster
// inside the VFS.
for (auto &E : RootEntries)
uniqueOverlayTree(FS, E.get());
return true;
}
};
std::unique_ptr<RedirectingFileSystem>
RedirectingFileSystem::create(std::unique_ptr<MemoryBuffer> Buffer,
SourceMgr::DiagHandlerTy DiagHandler,
StringRef YAMLFilePath, void *DiagContext,
IntrusiveRefCntPtr<FileSystem> ExternalFS) {
SourceMgr SM;
yaml::Stream Stream(Buffer->getMemBufferRef(), SM);
SM.setDiagHandler(DiagHandler, DiagContext);
yaml::document_iterator DI = Stream.begin();
yaml::Node *Root = DI->getRoot();
if (DI == Stream.end() || !Root) {
SM.PrintMessage(SMLoc(), SourceMgr::DK_Error, "expected root node");
return nullptr;
}
RedirectingFileSystemParser P(Stream);
std::unique_ptr<RedirectingFileSystem> FS(
new RedirectingFileSystem(ExternalFS));
if (!YAMLFilePath.empty()) {
// Use the YAML path from -ivfsoverlay to compute the dir to be prefixed
// to each 'external-contents' path.
//
// Example:
// -ivfsoverlay dummy.cache/vfs/vfs.yaml
// yields:
// FS->OverlayFileDir => /<absolute_path_to>/dummy.cache/vfs
//
SmallString<256> OverlayAbsDir = sys::path::parent_path(YAMLFilePath);
std::error_code EC = llvm::sys::fs::make_absolute(OverlayAbsDir);
assert(!EC && "Overlay dir final path must be absolute");
(void)EC;
FS->setOverlayFileDir(OverlayAbsDir);
}
if (!P.parse(Root, FS.get()))
return nullptr;
return FS;
}
std::unique_ptr<RedirectingFileSystem> RedirectingFileSystem::create(
ArrayRef<std::pair<std::string, std::string>> RemappedFiles,
bool UseExternalNames, FileSystem &ExternalFS) {
std::unique_ptr<RedirectingFileSystem> FS(
new RedirectingFileSystem(&ExternalFS));
FS->UseExternalNames = UseExternalNames;
StringMap<RedirectingFileSystem::Entry *> Entries;
for (auto &Mapping : llvm::reverse(RemappedFiles)) {
SmallString<128> From = StringRef(Mapping.first);
SmallString<128> To = StringRef(Mapping.second);
{
auto EC = ExternalFS.makeAbsolute(From);
(void)EC;
assert(!EC && "Could not make absolute path");
}
// Check if we've already mapped this file. The first one we see (in the
// reverse iteration) wins.
RedirectingFileSystem::Entry *&ToEntry = Entries[From];
if (ToEntry)
continue;
// Add parent directories.
RedirectingFileSystem::Entry *Parent = nullptr;
StringRef FromDirectory = llvm::sys::path::parent_path(From);
for (auto I = llvm::sys::path::begin(FromDirectory),
E = llvm::sys::path::end(FromDirectory);
I != E; ++I) {
Parent = RedirectingFileSystemParser::lookupOrCreateEntry(FS.get(), *I,
Parent);
}
assert(Parent && "File without a directory?");
{
auto EC = ExternalFS.makeAbsolute(To);
(void)EC;
assert(!EC && "Could not make absolute path");
}
// Add the file.
auto NewFile = std::make_unique<RedirectingFileSystem::FileEntry>(
llvm::sys::path::filename(From), To,
UseExternalNames ? RedirectingFileSystem::NK_External
: RedirectingFileSystem::NK_Virtual);
ToEntry = NewFile.get();
cast<RedirectingFileSystem::DirectoryEntry>(Parent)->addContent(
std::move(NewFile));
}
return FS;
}
RedirectingFileSystem::LookupResult::LookupResult(
Entry *E, sys::path::const_iterator Start, sys::path::const_iterator End)
: E(E) {
assert(E != nullptr);
// If the matched entry is a DirectoryRemapEntry, set ExternalRedirect to the
// path of the directory it maps to in the external file system plus any
// remaining path components in the provided iterator.
if (auto *DRE = dyn_cast<RedirectingFileSystem::DirectoryRemapEntry>(E)) {
SmallString<256> Redirect(DRE->getExternalContentsPath());
sys::path::append(Redirect, Start, End,
getExistingStyle(DRE->getExternalContentsPath()));
ExternalRedirect = std::string(Redirect);
}
}
void RedirectingFileSystem::LookupResult::getPath(
llvm::SmallVectorImpl<char> &Result) const {
Result.clear();
for (Entry *Parent : Parents)
llvm::sys::path::append(Result, Parent->getName());
llvm::sys::path::append(Result, E->getName());
}
std::error_code RedirectingFileSystem::makeCanonicalForLookup(
SmallVectorImpl<char> &Path) const {
if (std::error_code EC = makeAbsolute(Path))
return EC;
llvm::SmallString<256> CanonicalPath =
canonicalize(StringRef(Path.data(), Path.size()));
if (CanonicalPath.empty())
return make_error_code(llvm::errc::invalid_argument);
Path.assign(CanonicalPath.begin(), CanonicalPath.end());
return {};
}
ErrorOr<RedirectingFileSystem::LookupResult>
RedirectingFileSystem::lookupPath(StringRef Path) const {
llvm::SmallString<128> CanonicalPath(Path);
if (std::error_code EC = makeCanonicalForLookup(CanonicalPath))
return EC;
// RedirectOnly means the VFS is always used.
if (UsageTrackingActive && Redirection == RedirectKind::RedirectOnly)
HasBeenUsed = true;
sys::path::const_iterator Start = sys::path::begin(CanonicalPath);
sys::path::const_iterator End = sys::path::end(CanonicalPath);
llvm::SmallVector<Entry *, 32> Entries;
for (const auto &Root : Roots) {
ErrorOr<RedirectingFileSystem::LookupResult> Result =
lookupPathImpl(Start, End, Root.get(), Entries);
if (UsageTrackingActive && Result && isa<RemapEntry>(Result->E))
HasBeenUsed = true;
if (Result || Result.getError() != llvm::errc::no_such_file_or_directory) {
Result->Parents = std::move(Entries);
return Result;
}
}
return make_error_code(llvm::errc::no_such_file_or_directory);
}
ErrorOr<RedirectingFileSystem::LookupResult>
RedirectingFileSystem::lookupPathImpl(
sys::path::const_iterator Start, sys::path::const_iterator End,
RedirectingFileSystem::Entry *From,
llvm::SmallVectorImpl<Entry *> &Entries) const {
assert(!isTraversalComponent(*Start) &&
!isTraversalComponent(From->getName()) &&
"Paths should not contain traversal components");
StringRef FromName = From->getName();
// Forward the search to the next component in case this is an empty one.
if (!FromName.empty()) {
if (!pathComponentMatches(*Start, FromName))
return make_error_code(llvm::errc::no_such_file_or_directory);
++Start;
if (Start == End) {
// Match!
return LookupResult(From, Start, End);
}
}
if (isa<RedirectingFileSystem::FileEntry>(From))
return make_error_code(llvm::errc::not_a_directory);
if (isa<RedirectingFileSystem::DirectoryRemapEntry>(From))
return LookupResult(From, Start, End);
auto *DE = cast<RedirectingFileSystem::DirectoryEntry>(From);
for (const std::unique_ptr<RedirectingFileSystem::Entry> &DirEntry :
llvm::make_range(DE->contents_begin(), DE->contents_end())) {
Entries.push_back(From);
ErrorOr<RedirectingFileSystem::LookupResult> Result =
lookupPathImpl(Start, End, DirEntry.get(), Entries);
if (Result || Result.getError() != llvm::errc::no_such_file_or_directory)
return Result;
Entries.pop_back();
}
return make_error_code(llvm::errc::no_such_file_or_directory);
}
static Status getRedirectedFileStatus(const Twine &OriginalPath,
bool UseExternalNames,
Status ExternalStatus) {
// The path has been mapped by some nested VFS and exposes an external path,
// don't override it with the original path.
if (ExternalStatus.ExposesExternalVFSPath)
return ExternalStatus;
Status S = ExternalStatus;
if (!UseExternalNames)
S = Status::copyWithNewName(S, OriginalPath);
else
S.ExposesExternalVFSPath = true;
return S;
}
ErrorOr<Status> RedirectingFileSystem::status(
const Twine &LookupPath, const Twine &OriginalPath,
const RedirectingFileSystem::LookupResult &Result) {
if (std::optional<StringRef> ExtRedirect = Result.getExternalRedirect()) {
SmallString<256> RemappedPath((*ExtRedirect).str());
if (std::error_code EC = makeAbsolute(RemappedPath))
return EC;
ErrorOr<Status> S = ExternalFS->status(RemappedPath);
if (!S)
return S;
S = Status::copyWithNewName(*S, *ExtRedirect);
auto *RE = cast<RedirectingFileSystem::RemapEntry>(Result.E);
return getRedirectedFileStatus(OriginalPath,
RE->useExternalName(UseExternalNames), *S);
}
auto *DE = cast<RedirectingFileSystem::DirectoryEntry>(Result.E);
return Status::copyWithNewName(DE->getStatus(), LookupPath);
}
ErrorOr<Status>
RedirectingFileSystem::getExternalStatus(const Twine &LookupPath,
const Twine &OriginalPath) const {
auto Result = ExternalFS->status(LookupPath);
// The path has been mapped by some nested VFS, don't override it with the
// original path.
if (!Result || Result->ExposesExternalVFSPath)
return Result;
return Status::copyWithNewName(Result.get(), OriginalPath);
}
ErrorOr<Status> RedirectingFileSystem::status(const Twine &OriginalPath) {
SmallString<256> Path;
OriginalPath.toVector(Path);
if (std::error_code EC = makeAbsolute(Path))
return EC;
if (Redirection == RedirectKind::Fallback) {
// Attempt to find the original file first, only falling back to the
// mapped file if that fails.
ErrorOr<Status> S = getExternalStatus(Path, OriginalPath);
if (S)
return S;
}
ErrorOr<RedirectingFileSystem::LookupResult> Result = lookupPath(Path);
if (!Result) {
// Was not able to map file, fallthrough to using the original path if
// that was the specified redirection type.
if (Redirection == RedirectKind::Fallthrough &&
isFileNotFound(Result.getError()))
return getExternalStatus(Path, OriginalPath);
return Result.getError();
}
ErrorOr<Status> S = status(Path, OriginalPath, *Result);
if (!S && Redirection == RedirectKind::Fallthrough &&
isFileNotFound(S.getError(), Result->E)) {
// Mapped the file but it wasn't found in the underlying filesystem,
// fallthrough to using the original path if that was the specified
// redirection type.
return getExternalStatus(Path, OriginalPath);
}
return S;
}
bool RedirectingFileSystem::exists(const Twine &OriginalPath) {
SmallString<256> Path;
OriginalPath.toVector(Path);
if (makeAbsolute(Path))
return false;
if (Redirection == RedirectKind::Fallback) {
// Attempt to find the original file first, only falling back to the
// mapped file if that fails.
if (ExternalFS->exists(Path))
return true;
}
ErrorOr<RedirectingFileSystem::LookupResult> Result = lookupPath(Path);
if (!Result) {
// Was not able to map file, fallthrough to using the original path if
// that was the specified redirection type.
if (Redirection == RedirectKind::Fallthrough &&
isFileNotFound(Result.getError()))
return ExternalFS->exists(Path);
return false;
}
std::optional<StringRef> ExtRedirect = Result->getExternalRedirect();
if (!ExtRedirect) {
assert(isa<RedirectingFileSystem::DirectoryEntry>(Result->E));
return true;
}
SmallString<256> RemappedPath((*ExtRedirect).str());
if (makeAbsolute(RemappedPath))
return false;
if (ExternalFS->exists(RemappedPath))
return true;
if (Redirection == RedirectKind::Fallthrough) {
// Mapped the file but it wasn't found in the underlying filesystem,
// fallthrough to using the original path if that was the specified
// redirection type.
return ExternalFS->exists(Path);
}
return false;
}
namespace {
/// Provide a file wrapper with an overriden status.
class FileWithFixedStatus : public File {
std::unique_ptr<File> InnerFile;
Status S;
public:
FileWithFixedStatus(std::unique_ptr<File> InnerFile, Status S)
: InnerFile(std::move(InnerFile)), S(std::move(S)) {}
ErrorOr<Status> status() override { return S; }
ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
getBuffer(const Twine &Name, int64_t FileSize, bool RequiresNullTerminator,
bool IsVolatile) override {
return InnerFile->getBuffer(Name, FileSize, RequiresNullTerminator,
IsVolatile);
}
std::error_code close() override { return InnerFile->close(); }
void setPath(const Twine &Path) override { S = S.copyWithNewName(S, Path); }
};
} // namespace
ErrorOr<std::unique_ptr<File>>
File::getWithPath(ErrorOr<std::unique_ptr<File>> Result, const Twine &P) {
// See \c getRedirectedFileStatus - don't update path if it's exposing an
// external path.
if (!Result || (*Result)->status()->ExposesExternalVFSPath)
return Result;
ErrorOr<std::unique_ptr<File>> F = std::move(*Result);
auto Name = F->get()->getName();
if (Name && Name.get() != P.str())
F->get()->setPath(P);
return F;
}
ErrorOr<std::unique_ptr<File>>
RedirectingFileSystem::openFileForRead(const Twine &OriginalPath) {
SmallString<256> Path;
OriginalPath.toVector(Path);
if (std::error_code EC = makeAbsolute(Path))
return EC;
if (Redirection == RedirectKind::Fallback) {
// Attempt to find the original file first, only falling back to the
// mapped file if that fails.
auto F = File::getWithPath(ExternalFS->openFileForRead(Path), OriginalPath);
if (F)
return F;
}
ErrorOr<RedirectingFileSystem::LookupResult> Result = lookupPath(Path);
if (!Result) {
// Was not able to map file, fallthrough to using the original path if
// that was the specified redirection type.
if (Redirection == RedirectKind::Fallthrough &&
isFileNotFound(Result.getError()))
return File::getWithPath(ExternalFS->openFileForRead(Path), OriginalPath);
return Result.getError();
}
if (!Result->getExternalRedirect()) // FIXME: errc::not_a_file?
return make_error_code(llvm::errc::invalid_argument);
StringRef ExtRedirect = *Result->getExternalRedirect();
SmallString<256> RemappedPath(ExtRedirect.str());
if (std::error_code EC = makeAbsolute(RemappedPath))
return EC;
auto *RE = cast<RedirectingFileSystem::RemapEntry>(Result->E);
auto ExternalFile =
File::getWithPath(ExternalFS->openFileForRead(RemappedPath), ExtRedirect);
if (!ExternalFile) {
if (Redirection == RedirectKind::Fallthrough &&
isFileNotFound(ExternalFile.getError(), Result->E)) {
// Mapped the file but it wasn't found in the underlying filesystem,
// fallthrough to using the original path if that was the specified
// redirection type.
return File::getWithPath(ExternalFS->openFileForRead(Path), OriginalPath);
}
return ExternalFile;
}
auto ExternalStatus = (*ExternalFile)->status();
if (!ExternalStatus)
return ExternalStatus.getError();
// Otherwise, the file was successfully remapped. Mark it as such. Also
// replace the underlying path if the external name is being used.
Status S = getRedirectedFileStatus(
OriginalPath, RE->useExternalName(UseExternalNames), *ExternalStatus);
return std::unique_ptr<File>(
std::make_unique<FileWithFixedStatus>(std::move(*ExternalFile), S));
}
std::error_code
RedirectingFileSystem::getRealPath(const Twine &OriginalPath,
SmallVectorImpl<char> &Output) {
SmallString<256> Path;
OriginalPath.toVector(Path);
if (std::error_code EC = makeAbsolute(Path))
return EC;
if (Redirection == RedirectKind::Fallback) {
// Attempt to find the original file first, only falling back to the
// mapped file if that fails.
std::error_code EC = ExternalFS->getRealPath(Path, Output);
if (!EC)
return EC;
}
ErrorOr<RedirectingFileSystem::LookupResult> Result = lookupPath(Path);
if (!Result) {
// Was not able to map file, fallthrough to using the original path if
// that was the specified redirection type.
if (Redirection == RedirectKind::Fallthrough &&
isFileNotFound(Result.getError()))
return ExternalFS->getRealPath(Path, Output);
return Result.getError();
}
// If we found FileEntry or DirectoryRemapEntry, look up the mapped
// path in the external file system.
if (auto ExtRedirect = Result->getExternalRedirect()) {
auto P = ExternalFS->getRealPath(*ExtRedirect, Output);
if (P && Redirection == RedirectKind::Fallthrough &&
isFileNotFound(P, Result->E)) {
// Mapped the file but it wasn't found in the underlying filesystem,
// fallthrough to using the original path if that was the specified
// redirection type.
return ExternalFS->getRealPath(Path, Output);
}
return P;
}
// We found a DirectoryEntry, which does not have a single external contents
// path. Use the canonical virtual path.
if (Redirection == RedirectKind::Fallthrough) {
Result->getPath(Output);