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llvm-project/llvm/lib/Support/VirtualFileSystem.cpp

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//===- 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/None.h"
#include "llvm/ADT/Optional.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/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/Process.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 <mutex>
#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::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) const {
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();
}
#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 FD, StringRef NewName, StringRef NewRealPathName)
: FD(FD), 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;
};
} // 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;
}
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 (llvm::sys::fs::current_path(PWD))
return; // Awful, but nothing to do here.
if (llvm::sys::fs::real_path(PWD, RealPWD))
WD = {PWD, PWD};
else
WD = {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) 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)
return Path;
Path.toVector(Storage);
sys::fs::make_absolute(WD->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;
};
Optional<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)
return WD->Specified.str();
SmallString<128> Dir;
if (std::error_code EC = llvm::sys::fs::current_path(Dir))
return EC;
return Dir.str();
}
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 = {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) const {
SmallString<256> Storage;
return llvm::sys::fs::real_path(adjustPath(Path, Storage), Output);
}
IntrusiveRefCntPtr<FileSystem> vfs::getRealFileSystem() {
static IntrusiveRefCntPtr<FileSystem> FS(new RealFileSystem(true));
return FS;
}
std::unique_ptr<FileSystem> vfs::createPhysicalFileSystem() {
return llvm::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);
}
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) const {
for (auto &FS : FSList)
if (FS->exists(Path))
return FS->getRealPath(Path, Output);
return errc::no_such_file_or_directory;
}
llvm::vfs::detail::DirIterImpl::~DirIterImpl() = default;
namespace {
class OverlayFSDirIterImpl : public llvm::vfs::detail::DirIterImpl {
OverlayFileSystem &Overlays;
std::string Path;
OverlayFileSystem::iterator CurrentFS;
directory_iterator CurrentDirIter;
llvm::StringSet<> SeenNames;
std::error_code incrementFS() {
assert(CurrentFS != Overlays.overlays_end() && "incrementing past end");
++CurrentFS;
for (auto E = Overlays.overlays_end(); CurrentFS != E; ++CurrentFS) {
std::error_code EC;
CurrentDirIter = (*CurrentFS)->dir_begin(Path, EC);
if (EC && EC != errc::no_such_file_or_directory)
return EC;
if (CurrentDirIter != directory_iterator())
break; // found
}
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 = incrementFS();
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:
OverlayFSDirIterImpl(const Twine &Path, OverlayFileSystem &FS,
std::error_code &EC)
: Overlays(FS), Path(Path.str()), CurrentFS(Overlays.overlays_begin()) {
CurrentDirIter = (*CurrentFS)->dir_begin(Path, EC);
EC = incrementImpl(true);
}
std::error_code increment() override { return incrementImpl(false); }
};
} // namespace
directory_iterator OverlayFileSystem::dir_begin(const Twine &Dir,
std::error_code &EC) {
return directory_iterator(
std::make_shared<OverlayFSDirIterImpl>(Dir, *this, EC));
}
void ProxyFileSystem::anchor() {}
namespace llvm {
namespace vfs {
namespace detail {
enum InMemoryNodeKind { IME_File, IME_Directory, IME_HardLink };
/// The in memory file system is a tree of Nodes. Every node can either be a
/// file , hardlink or a directory.
class InMemoryNode {
InMemoryNodeKind Kind;
std::string FileName;
public:
InMemoryNode(llvm::StringRef FileName, InMemoryNodeKind Kind)
: Kind(Kind), FileName(llvm::sys::path::filename(FileName)) {}
virtual ~InMemoryNode() = default;
/// 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)) {}
/// 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 {
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; }
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;
}
};
/// 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 {}; }
};
} // namespace
class InMemoryDirectory : public InMemoryNode {
Status Stat;
llvm::StringMap<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 {
return Status::copyWithNewName(Stat, RequestedName);
}
InMemoryNode *getChild(StringRef Name) {
auto I = Entries.find(Name);
if (I != Entries.end())
return I->second.get();
return nullptr;
}
InMemoryNode *addChild(StringRef Name, std::unique_ptr<InMemoryNode> Child) {
return Entries.insert(make_pair(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 {
Status getNodeStatus(const InMemoryNode *Node, const Twine &RequestedName) {
if (auto Dir = dyn_cast<detail::InMemoryDirectory>(Node))
return Dir->getStatus(RequestedName);
if (auto File = dyn_cast<detail::InMemoryFile>(Node))
return File->getStatus(RequestedName);
if (auto Link = dyn_cast<detail::InMemoryHardLink>(Node))
return Link->getResolvedFile().getStatus(RequestedName);
llvm_unreachable("Unknown node type");
}
} // namespace
} // namespace detail
InMemoryFileSystem::InMemoryFileSystem(bool UseNormalizedPaths)
: Root(new detail::InMemoryDirectory(
Status("", getNextVirtualUniqueID(), 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,
Optional<uint32_t> User,
Optional<uint32_t> Group,
Optional<llvm::sys::fs::file_type> Type,
Optional<llvm::sys::fs::perms> Perms,
const detail::InMemoryFile *HardLinkTarget) {
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.getValueOr(0);
const auto ResolvedGroup = Group.getValueOr(0);
const auto ResolvedType = Type.getValueOr(sys::fs::file_type::regular_file);
const auto ResolvedPerms = Perms.getValueOr(sys::fs::all_all);
assert(!(HardLinkTarget && Buffer) && "HardLink cannot have a buffer");
// 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.
std::unique_ptr<detail::InMemoryNode> Child;
if (HardLinkTarget)
Child.reset(new detail::InMemoryHardLink(P.str(), *HardLinkTarget));
else {
// Create a new file or directory.
Status Stat(P.str(), getNextVirtualUniqueID(),
llvm::sys::toTimePoint(ModificationTime), ResolvedUser,
ResolvedGroup, Buffer->getBufferSize(), ResolvedType,
ResolvedPerms);
if (ResolvedType == sys::fs::file_type::directory_file) {
Child.reset(new detail::InMemoryDirectory(std::move(Stat)));
} else {
Child.reset(
new detail::InMemoryFile(std::move(Stat), std::move(Buffer)));
}
}
Dir->addChild(Name, std::move(Child));
return true;
}
// Create a new directory. Use the path up to here.
Status Stat(
StringRef(Path.str().begin(), Name.end() - Path.str().begin()),
getNextVirtualUniqueID(), llvm::sys::toTimePoint(ModificationTime),
ResolvedUser, ResolvedGroup, 0, sys::fs::file_type::directory_file,
NewDirectoryPerms);
Dir = cast<detail::InMemoryDirectory>(Dir->addChild(
Name, llvm::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,
Optional<uint32_t> User,
Optional<uint32_t> Group,
Optional<llvm::sys::fs::file_type> Type,
Optional<llvm::sys::fs::perms> Perms) {
return addFile(P, ModificationTime, std::move(Buffer), User, Group, Type,
Perms, /*HardLinkTarget=*/nullptr);
}
bool InMemoryFileSystem::addFileNoOwn(const Twine &P, time_t ModificationTime,
llvm::MemoryBuffer *Buffer,
Optional<uint32_t> User,
Optional<uint32_t> Group,
Optional<llvm::sys::fs::file_type> Type,
Optional<llvm::sys::fs::perms> Perms) {
return addFile(P, ModificationTime,
llvm::MemoryBuffer::getMemBuffer(
Buffer->getBuffer(), Buffer->getBufferIdentifier()),
std::move(User), std::move(Group), std::move(Type),
std::move(Perms));
}
static ErrorOr<const detail::InMemoryNode *>
lookupInMemoryNode(const InMemoryFileSystem &FS, detail::InMemoryDirectory *Dir,
const Twine &P) {
SmallString<128> Path;
P.toVector(Path);
// Fix up relative paths. This just prepends the current working directory.
std::error_code EC = FS.makeAbsolute(Path);
assert(!EC);
(void)EC;
if (FS.useNormalizedPaths())
llvm::sys::path::remove_dots(Path, /*remove_dot_dot=*/true);
if (Path.empty())
return 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;
// Return the file if it's at the end of the path.
if (auto File = dyn_cast<detail::InMemoryFile>(Node)) {
if (I == E)
return 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 &File->getResolvedFile();
return errc::no_such_file_or_directory;
}
// Traverse directories.
Dir = cast<detail::InMemoryDirectory>(Node);
if (I == E)
return Dir;
}
}
bool InMemoryFileSystem::addHardLink(const Twine &FromPath,
const Twine &ToPath) {
auto FromNode = lookupInMemoryNode(*this, Root.get(), FromPath);
auto ToNode = lookupInMemoryNode(*this, Root.get(), ToPath);
// FromPath must not have been added before. ToPath must have been added
// before. Resolved ToPath must be a File.
if (!ToNode || FromNode || !isa<detail::InMemoryFile>(*ToNode))
return false;
return this->addFile(FromPath, 0, nullptr, None, None, None, None,
cast<detail::InMemoryFile>(*ToNode));
}
llvm::ErrorOr<Status> InMemoryFileSystem::status(const Twine &Path) {
auto Node = lookupInMemoryNode(*this, Root.get(), Path);
if (Node)
return detail::getNodeStatus(*Node, Path);
return Node.getError();
}
llvm::ErrorOr<std::unique_ptr<File>>
InMemoryFileSystem::openFileForRead(const Twine &Path) {
auto Node = lookupInMemoryNode(*this, Root.get(), Path);
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);
}
namespace {
/// Adaptor from InMemoryDir::iterator to directory_iterator.
class InMemoryDirIterator : public llvm::vfs::detail::DirIterImpl {
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;
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;
}
CurrentEntry = directory_entry(Path.str(), Type);
} else {
// When we're at the end, make CurrentEntry invalid and DirIterImpl will
// do the rest.
CurrentEntry = directory_entry();
}
}
public:
InMemoryDirIterator() = default;
explicit InMemoryDirIterator(const detail::InMemoryDirectory &Dir,
std::string RequestedDirName)
: I(Dir.begin()), E(Dir.end()),
RequestedDirName(std::move(RequestedDirName)) {
setCurrentEntry();
}
std::error_code increment() override {
++I;
setCurrentEntry();
return {};
}
};
} // namespace
directory_iterator InMemoryFileSystem::dir_begin(const Twine &Dir,
std::error_code &EC) {
auto Node = lookupInMemoryNode(*this, Root.get(), Dir);
if (!Node) {
EC = Node.getError();
return directory_iterator(std::make_shared<InMemoryDirIterator>());
}
if (auto *DirNode = dyn_cast<detail::InMemoryDirectory>(*Node))
return directory_iterator(
std::make_shared<InMemoryDirIterator>(*DirNode, Dir.str()));
EC = make_error_code(llvm::errc::not_a_directory);
return directory_iterator(std::make_shared<InMemoryDirIterator>());
}
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 = Path.str();
return {};
}
std::error_code
InMemoryFileSystem::getRealPath(const Twine &Path,
SmallVectorImpl<char> &Output) const {
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 {};
}
} // namespace vfs
} // namespace llvm
//===-----------------------------------------------------------------------===/
// RedirectingFileSystem implementation
//===-----------------------------------------------------------------------===/
// FIXME: reuse implementation common with OverlayFSDirIterImpl as these
// iterators are conceptually similar.
class llvm::vfs::VFSFromYamlDirIterImpl
: public llvm::vfs::detail::DirIterImpl {
std::string Dir;
RedirectingFileSystem::RedirectingDirectoryEntry::iterator Current, End;
// To handle 'fallthrough' mode we need to iterate at first through
// RedirectingDirectoryEntry and then through ExternalFS. These operations are
// done sequentially, we just need to keep a track of what kind of iteration
// we are currently performing.
/// Flag telling if we should iterate through ExternalFS or stop at the last
/// RedirectingDirectoryEntry::iterator.
bool IterateExternalFS;
/// Flag telling if we have switched to iterating through ExternalFS.
bool IsExternalFSCurrent = false;
FileSystem &ExternalFS;
directory_iterator ExternalDirIter;
llvm::StringSet<> SeenNames;
/// To combine multiple iterations, different methods are responsible for
/// different iteration steps.
/// @{
/// Responsible for dispatching between RedirectingDirectoryEntry iteration
/// and ExternalFS iteration.
std::error_code incrementImpl(bool IsFirstTime);
/// Responsible for RedirectingDirectoryEntry iteration.
std::error_code incrementContent(bool IsFirstTime);
/// Responsible for ExternalFS iteration.
std::error_code incrementExternal();
/// @}
public:
VFSFromYamlDirIterImpl(
const Twine &Path,
RedirectingFileSystem::RedirectingDirectoryEntry::iterator Begin,
RedirectingFileSystem::RedirectingDirectoryEntry::iterator End,
bool IterateExternalFS, FileSystem &ExternalFS, std::error_code &EC);
std::error_code increment() override;
};
llvm::ErrorOr<std::string>
RedirectingFileSystem::getCurrentWorkingDirectory() const {
return ExternalFS->getCurrentWorkingDirectory();
}
std::error_code
RedirectingFileSystem::setCurrentWorkingDirectory(const Twine &Path) {
return ExternalFS->setCurrentWorkingDirectory(Path);
}
std::error_code RedirectingFileSystem::isLocal(const Twine &Path,
bool &Result) {
return ExternalFS->isLocal(Path, Result);
}
directory_iterator RedirectingFileSystem::dir_begin(const Twine &Dir,
std::error_code &EC) {
ErrorOr<RedirectingFileSystem::Entry *> E = lookupPath(Dir);
if (!E) {
EC = E.getError();
if (IsFallthrough && EC == errc::no_such_file_or_directory)
return ExternalFS->dir_begin(Dir, EC);
return {};
}
ErrorOr<Status> S = status(Dir, *E);
if (!S) {
EC = S.getError();
return {};
}
if (!S->isDirectory()) {
EC = std::error_code(static_cast<int>(errc::not_a_directory),
std::system_category());
return {};
}
auto *D = cast<RedirectingFileSystem::RedirectingDirectoryEntry>(*E);
return directory_iterator(std::make_shared<VFSFromYamlDirIterImpl>(
Dir, D->contents_begin(), D->contents_end(),
/*IterateExternalFS=*/IsFallthrough, *ExternalFS, EC));
}
void RedirectingFileSystem::setExternalContentsPrefixDir(StringRef PrefixDir) {
ExternalContentsPrefixDir = PrefixDir.str();
}
StringRef RedirectingFileSystem::getExternalContentsPrefixDir() const {
return ExternalContentsPrefixDir;
}
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
LLVM_DUMP_METHOD void RedirectingFileSystem::dump() const {
for (const auto &Root : Roots)
dumpEntry(Root.get());
}
LLVM_DUMP_METHOD void
RedirectingFileSystem::dumpEntry(RedirectingFileSystem::Entry *E,
int NumSpaces) const {
StringRef Name = E->getName();
for (int i = 0, e = NumSpaces; i < e; ++i)
dbgs() << " ";
dbgs() << "'" << Name.str().c_str() << "'"
<< "\n";
if (E->getKind() == RedirectingFileSystem::EK_Directory) {
auto *DE = dyn_cast<RedirectingFileSystem::RedirectingDirectoryEntry>(E);
assert(DE && "Should be a directory");
for (std::unique_ptr<Entry> &SubEntry :
llvm::make_range(DE->contents_begin(), DE->contents_end()))
dumpEntry(SubEntry.get(), NumSpaces + 2);
}
}
#endif
/// 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_lower("true") || Value.equals_lower("on") ||
Value.equals_lower("yes") || Value == "1") {
Result = true;
return true;
} else if (Value.equals_lower("false") || Value.equals_lower("off") ||
Value.equals_lower("no") || Value == "0") {
Result = false;
return true;
}
error(N, "expected boolean value");
return false;
}
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;
}
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::RedirectingDirectoryEntry>(
ParentEntry);
for (std::unique_ptr<RedirectingFileSystem::Entry> &Content :
llvm::make_range(DE->contents_begin(), DE->contents_end())) {
auto *DirContent =
dyn_cast<RedirectingFileSystem::RedirectingDirectoryEntry>(
Content.get());
if (DirContent && Name.equals(Content->getName()))
return DirContent;
}
}
// ... or create a new one
std::unique_ptr<RedirectingFileSystem::Entry> E =
llvm::make_unique<RedirectingFileSystem::RedirectingDirectoryEntry>(
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 =
dyn_cast<RedirectingFileSystem::RedirectingDirectoryEntry>(ParentEntry);
DE->addContent(std::move(E));
return DE->getLastContent();
}
void uniqueOverlayTree(RedirectingFileSystem *FS,
RedirectingFileSystem::Entry *SrcE,
RedirectingFileSystem::Entry *NewParentE = nullptr) {
StringRef Name = SrcE->getName();
switch (SrcE->getKind()) {
case RedirectingFileSystem::EK_Directory: {
auto *DE =
dyn_cast<RedirectingFileSystem::RedirectingDirectoryEntry>(SrcE);
assert(DE && "Must be a directory");
// 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_File: {
auto *FE = dyn_cast<RedirectingFileSystem::RedirectingFileEntry>(SrcE);
assert(FE && "Must be a file");
assert(NewParentE && "Parent entry must exist");
auto *DE = dyn_cast<RedirectingFileSystem::RedirectingDirectoryEntry>(
NewParentE);
DE->addContent(
llvm::make_unique<RedirectingFileSystem::RedirectingFileEntry>(
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));
bool HasContents = false; // external or otherwise
std::vector<std::unique_ptr<RedirectingFileSystem::Entry>>
EntryArrayContents;
std::string ExternalContentsPath;
std::string Name;
yaml::Node *NameValueNode = nullptr;
auto UseExternalName =
RedirectingFileSystem::RedirectingFileEntry::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();
if (FS->UseCanonicalizedPaths) {
SmallString<256> Path(Value);
// Guarantee that old YAML files containing paths with ".." and "."
// are properly canonicalized before read into the VFS.
Path = sys::path::remove_leading_dotslash(Path);
sys::path::remove_dots(Path, /*remove_dot_dot=*/true);
Name = Path.str();
} else {
Name = Value;
}
} 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 {
error(I.getValue(), "unknown value for 'type'");
return nullptr;
}
} else if (Key == "contents") {
if (HasContents) {
error(I.getKey(),
"entry already has 'contents' or 'external-contents'");
return nullptr;
}
HasContents = true;
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 (HasContents) {
error(I.getKey(),
"entry already has 'contents' or 'external-contents'");
return nullptr;
}
HasContents = true;
if (!parseScalarString(I.getValue(), Value, Buffer))
return nullptr;
SmallString<256> FullPath;
if (FS->IsRelativeOverlay) {
FullPath = FS->getExternalContentsPrefixDir();
assert(!FullPath.empty() &&
"External contents prefix directory must exist");
llvm::sys::path::append(FullPath, Value);
} else {
FullPath = Value;
}
if (FS->UseCanonicalizedPaths) {
// Guarantee that old YAML files containing paths with ".." and "."
// are properly canonicalized before read into the VFS.
FullPath = sys::path::remove_leading_dotslash(FullPath);
sys::path::remove_dots(FullPath, /*remove_dot_dot=*/true);
}
ExternalContentsPath = FullPath.str();
} else if (Key == "use-external-name") {
bool Val;
if (!parseScalarBool(I.getValue(), Val))
return nullptr;
UseExternalName =
Val ? RedirectingFileSystem::RedirectingFileEntry::NK_External
: RedirectingFileSystem::RedirectingFileEntry::NK_Virtual;
} else {
llvm_unreachable("key missing from Keys");
}
}
if (Stream.failed())
return nullptr;
// check for missing keys
if (!HasContents) {
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::RedirectingFileEntry::NK_NotSet) {
error(N, "'use-external-name' is not supported for directories");
return nullptr;
}
if (IsRootEntry && !sys::path::is_absolute(Name)) {
assert(NameValueNode && "Name presence should be checked earlier");
error(NameValueNode,
"entry with relative path at the root level is not discoverable");
return nullptr;
}
// Remove trailing slash(es), being careful not to remove the root path
StringRef Trimmed(Name);
size_t RootPathLen = sys::path::root_path(Trimmed).size();
while (Trimmed.size() > RootPathLen &&
sys::path::is_separator(Trimmed.back()))
Trimmed = Trimmed.slice(0, Trimmed.size() - 1);
// Get the last component
StringRef LastComponent = sys::path::filename(Trimmed);
std::unique_ptr<RedirectingFileSystem::Entry> Result;
switch (Kind) {
case RedirectingFileSystem::EK_File:
Result = llvm::make_unique<RedirectingFileSystem::RedirectingFileEntry>(
LastComponent, std::move(ExternalContentsPath), UseExternalName);
break;
case RedirectingFileSystem::EK_Directory:
Result =
llvm::make_unique<RedirectingFileSystem::RedirectingDirectoryEntry>(
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);
if (Parent.empty())
return Result;
// if 'name' contains multiple components, create implicit directory entries
for (sys::path::reverse_iterator I = sys::path::rbegin(Parent),
E = sys::path::rend(Parent);
I != E; ++I) {
std::vector<std::unique_ptr<RedirectingFileSystem::Entry>> Entries;
Entries.push_back(std::move(Result));
Result =
llvm::make_unique<RedirectingFileSystem::RedirectingDirectoryEntry>(
*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("overlay-relative", false),
KeyStatusPair("fallthrough", 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 (!parseScalarBool(I.getValue(), FS->IsFallthrough))
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;
}
};
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(std::move(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->ExternalContentsPrefixDir => /<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->setExternalContentsPrefixDir(OverlayAbsDir);
}
if (!P.parse(Root, FS.get()))
return nullptr;
return FS.release();
}
ErrorOr<RedirectingFileSystem::Entry *>
RedirectingFileSystem::lookupPath(const Twine &Path_) const {
SmallString<256> Path;
Path_.toVector(Path);
// Handle relative paths
if (std::error_code EC = makeAbsolute(Path))
return EC;
// Canonicalize path by removing ".", "..", "./", etc components. This is
// a VFS request, do bot bother about symlinks in the path components
// but canonicalize in order to perform the correct entry search.
if (UseCanonicalizedPaths) {
Path = sys::path::remove_leading_dotslash(Path);
sys::path::remove_dots(Path, /*remove_dot_dot=*/true);
}
if (Path.empty())
return make_error_code(llvm::errc::invalid_argument);
sys::path::const_iterator Start = sys::path::begin(Path);
sys::path::const_iterator End = sys::path::end(Path);
for (const auto &Root : Roots) {
ErrorOr<RedirectingFileSystem::Entry *> Result =
lookupPath(Start, End, Root.get());
if (Result || Result.getError() != llvm::errc::no_such_file_or_directory)
return Result;
}
return make_error_code(llvm::errc::no_such_file_or_directory);
}
ErrorOr<RedirectingFileSystem::Entry *>
RedirectingFileSystem::lookupPath(sys::path::const_iterator Start,
sys::path::const_iterator End,
RedirectingFileSystem::Entry *From) const {
#ifndef _WIN32
assert(!isTraversalComponent(*Start) &&
!isTraversalComponent(From->getName()) &&
"Paths should not contain traversal components");
#else
// FIXME: this is here to support windows, remove it once canonicalized
// paths become globally default.
if (Start->equals("."))
++Start;
#endif
StringRef FromName = From->getName();
// Forward the search to the next component in case this is an empty one.
if (!FromName.empty()) {
if (CaseSensitive ? !Start->equals(FromName)
: !Start->equals_lower(FromName))
// failure to match
return make_error_code(llvm::errc::no_such_file_or_directory);
++Start;
if (Start == End) {
// Match!
return From;
}
}
auto *DE = dyn_cast<RedirectingFileSystem::RedirectingDirectoryEntry>(From);
if (!DE)
return make_error_code(llvm::errc::not_a_directory);
for (const std::unique_ptr<RedirectingFileSystem::Entry> &DirEntry :
llvm::make_range(DE->contents_begin(), DE->contents_end())) {
ErrorOr<RedirectingFileSystem::Entry *> Result =
lookupPath(Start, End, DirEntry.get());
if (Result || Result.getError() != llvm::errc::no_such_file_or_directory)
return Result;
}
return make_error_code(llvm::errc::no_such_file_or_directory);
}
static Status getRedirectedFileStatus(const Twine &Path, bool UseExternalNames,
Status ExternalStatus) {
Status S = ExternalStatus;
if (!UseExternalNames)
S = Status::copyWithNewName(S, Path);
S.IsVFSMapped = true;
return S;
}
ErrorOr<Status> RedirectingFileSystem::status(const Twine &Path,
RedirectingFileSystem::Entry *E) {
assert(E != nullptr);
if (auto *F = dyn_cast<RedirectingFileSystem::RedirectingFileEntry>(E)) {
ErrorOr<Status> S = ExternalFS->status(F->getExternalContentsPath());
assert(!S || S->getName() == F->getExternalContentsPath());
if (S)
return getRedirectedFileStatus(Path, F->useExternalName(UseExternalNames),
*S);
return S;
} else { // directory
auto *DE = cast<RedirectingFileSystem::RedirectingDirectoryEntry>(E);
return Status::copyWithNewName(DE->getStatus(), Path);
}
}
ErrorOr<Status> RedirectingFileSystem::status(const Twine &Path) {
ErrorOr<RedirectingFileSystem::Entry *> Result = lookupPath(Path);
if (!Result) {
if (IsFallthrough &&
Result.getError() == llvm::errc::no_such_file_or_directory) {
return ExternalFS->status(Path);
}
return Result.getError();
}
return status(Path, *Result);
}
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(); }
};
} // namespace
ErrorOr<std::unique_ptr<File>>
RedirectingFileSystem::openFileForRead(const Twine &Path) {
ErrorOr<RedirectingFileSystem::Entry *> E = lookupPath(Path);
if (!E) {
if (IsFallthrough &&
E.getError() == llvm::errc::no_such_file_or_directory) {
return ExternalFS->openFileForRead(Path);
}
return E.getError();
}
auto *F = dyn_cast<RedirectingFileSystem::RedirectingFileEntry>(*E);
if (!F) // FIXME: errc::not_a_file?
return make_error_code(llvm::errc::invalid_argument);
auto Result = ExternalFS->openFileForRead(F->getExternalContentsPath());
if (!Result)
return Result;
auto ExternalStatus = (*Result)->status();
if (!ExternalStatus)
return ExternalStatus.getError();
// FIXME: Update the status with the name and VFSMapped.
Status S = getRedirectedFileStatus(Path, F->useExternalName(UseExternalNames),
*ExternalStatus);
return std::unique_ptr<File>(
llvm::make_unique<FileWithFixedStatus>(std::move(*Result), S));
}
std::error_code
RedirectingFileSystem::getRealPath(const Twine &Path,
SmallVectorImpl<char> &Output) const {
ErrorOr<RedirectingFileSystem::Entry *> Result = lookupPath(Path);
if (!Result) {
if (IsFallthrough &&
Result.getError() == llvm::errc::no_such_file_or_directory) {
return ExternalFS->getRealPath(Path, Output);
}
return Result.getError();
}
if (auto *F =
dyn_cast<RedirectingFileSystem::RedirectingFileEntry>(*Result)) {
return ExternalFS->getRealPath(F->getExternalContentsPath(), Output);
}
// Even if there is a directory entry, fall back to ExternalFS if allowed,
// because directories don't have a single external contents path.
return IsFallthrough ? ExternalFS->getRealPath(Path, Output)
: llvm::errc::invalid_argument;
}
IntrusiveRefCntPtr<FileSystem>
vfs::getVFSFromYAML(std::unique_ptr<MemoryBuffer> Buffer,
SourceMgr::DiagHandlerTy DiagHandler,
StringRef YAMLFilePath, void *DiagContext,
IntrusiveRefCntPtr<FileSystem> ExternalFS) {
return RedirectingFileSystem::create(std::move(Buffer), DiagHandler,
YAMLFilePath, DiagContext,
std::move(ExternalFS));
}
static void getVFSEntries(RedirectingFileSystem::Entry *SrcE,
SmallVectorImpl<StringRef> &Path,
SmallVectorImpl<YAMLVFSEntry> &Entries) {
auto Kind = SrcE->getKind();
if (Kind == RedirectingFileSystem::EK_Directory) {
auto *DE = dyn_cast<RedirectingFileSystem::RedirectingDirectoryEntry>(SrcE);
assert(DE && "Must be a directory");
for (std::unique_ptr<RedirectingFileSystem::Entry> &SubEntry :
llvm::make_range(DE->contents_begin(), DE->contents_end())) {
Path.push_back(SubEntry->getName());
getVFSEntries(SubEntry.get(), Path, Entries);
Path.pop_back();
}
return;
}
assert(Kind == RedirectingFileSystem::EK_File && "Must be a EK_File");
auto *FE = dyn_cast<RedirectingFileSystem::RedirectingFileEntry>(SrcE);
assert(FE && "Must be a file");
SmallString<128> VPath;
for (auto &Comp : Path)
llvm::sys::path::append(VPath, Comp);
Entries.push_back(YAMLVFSEntry(VPath.c_str(), FE->getExternalContentsPath()));
}
void vfs::collectVFSFromYAML(std::unique_ptr<MemoryBuffer> Buffer,
SourceMgr::DiagHandlerTy DiagHandler,
StringRef YAMLFilePath,
SmallVectorImpl<YAMLVFSEntry> &CollectedEntries,
void *DiagContext,
IntrusiveRefCntPtr<FileSystem> ExternalFS) {
RedirectingFileSystem *VFS = RedirectingFileSystem::create(
std::move(Buffer), DiagHandler, YAMLFilePath, DiagContext,
std::move(ExternalFS));
ErrorOr<RedirectingFileSystem::Entry *> RootE = VFS->lookupPath("/");
if (!RootE)
return;
SmallVector<StringRef, 8> Components;
Components.push_back("/");
getVFSEntries(*RootE, Components, CollectedEntries);
}
UniqueID vfs::getNextVirtualUniqueID() {
static std::atomic<unsigned> UID;
unsigned ID = ++UID;
// The following assumes that uint64_t max will never collide with a real
// dev_t value from the OS.
return UniqueID(std::numeric_limits<uint64_t>::max(), ID);
}
void YAMLVFSWriter::addFileMapping(StringRef VirtualPath, StringRef RealPath) {
assert(sys::path::is_absolute(VirtualPath) && "virtual path not absolute");
assert(sys::path::is_absolute(RealPath) && "real path not absolute");
assert(!pathHasTraversal(VirtualPath) && "path traversal is not supported");
Mappings.emplace_back(VirtualPath, RealPath);
}
namespace {
class JSONWriter {
llvm::raw_ostream &OS;
SmallVector<StringRef, 16> DirStack;
unsigned getDirIndent() { return 4 * DirStack.size(); }
unsigned getFileIndent() { return 4 * (DirStack.size() + 1); }
bool containedIn(StringRef Parent, StringRef Path);
StringRef containedPart(StringRef Parent, StringRef Path);
void startDirectory(StringRef Path);
void endDirectory();
void writeEntry(StringRef VPath, StringRef RPath);
public:
JSONWriter(llvm::raw_ostream &OS) : OS(OS) {}
void write(ArrayRef<YAMLVFSEntry> Entries, Optional<bool> UseExternalNames,
Optional<bool> IsCaseSensitive, Optional<bool> IsOverlayRelative,
StringRef OverlayDir);
};
} // namespace
bool JSONWriter::containedIn(StringRef Parent, StringRef Path) {
using namespace llvm::sys;
// Compare each path component.
auto IParent = path::begin(Parent), EParent = path::end(Parent);
for (auto IChild = path::begin(Path), EChild = path::end(Path);
IParent != EParent && IChild != EChild; ++IParent, ++IChild) {
if (*IParent != *IChild)
return false;
}
// Have we exhausted the parent path?
return IParent == EParent;
}
StringRef JSONWriter::containedPart(StringRef Parent, StringRef Path) {
assert(!Parent.empty());
assert(containedIn(Parent, Path));
return Path.slice(Parent.size() + 1, StringRef::npos);
}
void JSONWriter::startDirectory(StringRef Path) {
StringRef Name =
DirStack.empty() ? Path : containedPart(DirStack.back(), Path);
DirStack.push_back(Path);
unsigned Indent = getDirIndent();
OS.indent(Indent) << "{\n";
OS.indent(Indent + 2) << "'type': 'directory',\n";
OS.indent(Indent + 2) << "'name': \"" << llvm::yaml::escape(Name) << "\",\n";
OS.indent(Indent + 2) << "'contents': [\n";
}
void JSONWriter::endDirectory() {
unsigned Indent = getDirIndent();
OS.indent(Indent + 2) << "]\n";
OS.indent(Indent) << "}";
DirStack.pop_back();
}
void JSONWriter::writeEntry(StringRef VPath, StringRef RPath) {
unsigned Indent = getFileIndent();
OS.indent(Indent) << "{\n";
OS.indent(Indent + 2) << "'type': 'file',\n";
OS.indent(Indent + 2) << "'name': \"" << llvm::yaml::escape(VPath) << "\",\n";
OS.indent(Indent + 2) << "'external-contents': \""
<< llvm::yaml::escape(RPath) << "\"\n";
OS.indent(Indent) << "}";
}
void JSONWriter::write(ArrayRef<YAMLVFSEntry> Entries,
Optional<bool> UseExternalNames,
Optional<bool> IsCaseSensitive,
Optional<bool> IsOverlayRelative,
StringRef OverlayDir) {
using namespace llvm::sys;
OS << "{\n"
" 'version': 0,\n";
if (IsCaseSensitive.hasValue())
OS << " 'case-sensitive': '"
<< (IsCaseSensitive.getValue() ? "true" : "false") << "',\n";
if (UseExternalNames.hasValue())
OS << " 'use-external-names': '"
<< (UseExternalNames.getValue() ? "true" : "false") << "',\n";
bool UseOverlayRelative = false;
if (IsOverlayRelative.hasValue()) {
UseOverlayRelative = IsOverlayRelative.getValue();
OS << " 'overlay-relative': '" << (UseOverlayRelative ? "true" : "false")
<< "',\n";
}
OS << " 'roots': [\n";
if (!Entries.empty()) {
const YAMLVFSEntry &Entry = Entries.front();
startDirectory(path::parent_path(Entry.VPath));
StringRef RPath = Entry.RPath;
if (UseOverlayRelative) {
unsigned OverlayDirLen = OverlayDir.size();
assert(RPath.substr(0, OverlayDirLen) == OverlayDir &&
"Overlay dir must be contained in RPath");
RPath = RPath.slice(OverlayDirLen, RPath.size());
}
writeEntry(path::filename(Entry.VPath), RPath);
for (const auto &Entry : Entries.slice(1)) {
StringRef Dir = path::parent_path(Entry.VPath);
if (Dir == DirStack.back())
OS << ",\n";
else {
while (!DirStack.empty() && !containedIn(DirStack.back(), Dir)) {
OS << "\n";
endDirectory();
}
OS << ",\n";
startDirectory(Dir);
}
StringRef RPath = Entry.RPath;
if (UseOverlayRelative) {
unsigned OverlayDirLen = OverlayDir.size();
assert(RPath.substr(0, OverlayDirLen) == OverlayDir &&
"Overlay dir must be contained in RPath");
RPath = RPath.slice(OverlayDirLen, RPath.size());
}
writeEntry(path::filename(Entry.VPath), RPath);
}
while (!DirStack.empty()) {
OS << "\n";
endDirectory();
}
OS << "\n";
}
OS << " ]\n"
<< "}\n";
}
void YAMLVFSWriter::write(llvm::raw_ostream &OS) {
llvm::sort(Mappings, [](const YAMLVFSEntry &LHS, const YAMLVFSEntry &RHS) {
return LHS.VPath < RHS.VPath;
});
JSONWriter(OS).write(Mappings, UseExternalNames, IsCaseSensitive,
IsOverlayRelative, OverlayDir);
}
VFSFromYamlDirIterImpl::VFSFromYamlDirIterImpl(
const Twine &_Path,
RedirectingFileSystem::RedirectingDirectoryEntry::iterator Begin,
RedirectingFileSystem::RedirectingDirectoryEntry::iterator End,
bool IterateExternalFS, FileSystem &ExternalFS, std::error_code &EC)
: Dir(_Path.str()), Current(Begin), End(End),
IterateExternalFS(IterateExternalFS), ExternalFS(ExternalFS) {
EC = incrementImpl(/*IsFirstTime=*/true);
}
std::error_code VFSFromYamlDirIterImpl::increment() {
return incrementImpl(/*IsFirstTime=*/false);
}
std::error_code VFSFromYamlDirIterImpl::incrementExternal() {
assert(!(IsExternalFSCurrent && ExternalDirIter == directory_iterator()) &&
"incrementing past end");
std::error_code EC;
if (IsExternalFSCurrent) {
ExternalDirIter.increment(EC);
} else if (IterateExternalFS) {
ExternalDirIter = ExternalFS.dir_begin(Dir, EC);
IsExternalFSCurrent = true;
if (EC && EC != errc::no_such_file_or_directory)
return EC;
EC = {};
}
if (EC || ExternalDirIter == directory_iterator()) {
CurrentEntry = directory_entry();
} else {
CurrentEntry = *ExternalDirIter;
}
return EC;
}
std::error_code VFSFromYamlDirIterImpl::incrementContent(bool IsFirstTime) {
assert((IsFirstTime || Current != End) && "cannot iterate past end");
if (!IsFirstTime)
++Current;
while (Current != End) {
SmallString<128> PathStr(Dir);
llvm::sys::path::append(PathStr, (*Current)->getName());
sys::fs::file_type Type;
switch ((*Current)->getKind()) {
case RedirectingFileSystem::EK_Directory:
Type = sys::fs::file_type::directory_file;
break;
case RedirectingFileSystem::EK_File:
Type = sys::fs::file_type::regular_file;
break;
}
CurrentEntry = directory_entry(PathStr.str(), Type);
return {};
}
return incrementExternal();
}
std::error_code VFSFromYamlDirIterImpl::incrementImpl(bool IsFirstTime) {
while (true) {
std::error_code EC = IsExternalFSCurrent ? incrementExternal()
: incrementContent(IsFirstTime);
if (EC || CurrentEntry.path().empty())
return EC;
StringRef Name = llvm::sys::path::filename(CurrentEntry.path());
if (SeenNames.insert(Name).second)
return EC; // name not seen before
}
llvm_unreachable("returned above");
}
vfs::recursive_directory_iterator::recursive_directory_iterator(
FileSystem &FS_, const Twine &Path, std::error_code &EC)
: FS(&FS_) {
directory_iterator I = FS->dir_begin(Path, EC);
if (I != directory_iterator()) {
State = std::make_shared<detail::RecDirIterState>();
State->Stack.push(I);
}
}
vfs::recursive_directory_iterator &
recursive_directory_iterator::increment(std::error_code &EC) {
assert(FS && State && !State->Stack.empty() && "incrementing past end");
assert(!State->Stack.top()->path().empty() && "non-canonical end iterator");
vfs::directory_iterator End;
if (State->HasNoPushRequest)
State->HasNoPushRequest = false;
else {
if (State->Stack.top()->type() == sys::fs::file_type::directory_file) {
vfs::directory_iterator I = FS->dir_begin(State->Stack.top()->path(), EC);
if (I != End) {
State->Stack.push(I);
return *this;
}
}
}
while (!State->Stack.empty() && State->Stack.top().increment(EC) == End)
State->Stack.pop();
if (State->Stack.empty())
State.reset(); // end iterator
return *this;
}
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