forked from OSchip/llvm-project
84 lines
3.0 KiB
C++
84 lines
3.0 KiB
C++
//===--- FSProvider.cpp - VFS provider for ClangdServer -------------------===//
|
|
//
|
|
// 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
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "FSProvider.h"
|
|
#include "llvm/ADT/STLExtras.h"
|
|
#include "llvm/ADT/SmallString.h"
|
|
#include "llvm/ADT/StringRef.h"
|
|
#include "llvm/Support/Path.h"
|
|
#include "llvm/Support/VirtualFileSystem.h"
|
|
#include <memory>
|
|
|
|
namespace clang {
|
|
namespace clangd {
|
|
|
|
namespace {
|
|
/// Always opens files in the underlying filesystem as "volatile", meaning they
|
|
/// won't be memory-mapped. Memory-mapping isn't desirable for clangd:
|
|
/// - edits to the underlying files change contents MemoryBuffers owned by
|
|
// SourceManager, breaking its invariants and leading to crashes
|
|
/// - it locks files on windows, preventing edits
|
|
class VolatileFileSystem : public llvm::vfs::ProxyFileSystem {
|
|
public:
|
|
explicit VolatileFileSystem(llvm::IntrusiveRefCntPtr<FileSystem> FS)
|
|
: ProxyFileSystem(std::move(FS)) {}
|
|
|
|
llvm::ErrorOr<std::unique_ptr<llvm::vfs::File>>
|
|
openFileForRead(const llvm::Twine &InPath) override {
|
|
llvm::SmallString<128> Path;
|
|
InPath.toVector(Path);
|
|
|
|
auto File = getUnderlyingFS().openFileForRead(Path);
|
|
if (!File)
|
|
return File;
|
|
// Try to guess preamble files, they can be memory-mapped even on Windows as
|
|
// clangd has exclusive access to those and nothing else should touch them.
|
|
llvm::StringRef FileName = llvm::sys::path::filename(Path);
|
|
if (FileName.startswith("preamble-") && FileName.endswith(".pch"))
|
|
return File;
|
|
return std::unique_ptr<VolatileFile>(new VolatileFile(std::move(*File)));
|
|
}
|
|
|
|
private:
|
|
class VolatileFile : public llvm::vfs::File {
|
|
public:
|
|
VolatileFile(std::unique_ptr<llvm::vfs::File> Wrapped)
|
|
: Wrapped(std::move(Wrapped)) {
|
|
assert(this->Wrapped);
|
|
}
|
|
|
|
virtual llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
|
|
getBuffer(const llvm::Twine &Name, int64_t FileSize,
|
|
bool RequiresNullTerminator, bool /*IsVolatile*/) override {
|
|
return Wrapped->getBuffer(Name, FileSize, RequiresNullTerminator,
|
|
/*IsVolatile=*/true);
|
|
}
|
|
|
|
llvm::ErrorOr<llvm::vfs::Status> status() override {
|
|
return Wrapped->status();
|
|
}
|
|
llvm::ErrorOr<std::string> getName() override { return Wrapped->getName(); }
|
|
std::error_code close() override { return Wrapped->close(); }
|
|
|
|
private:
|
|
std::unique_ptr<File> Wrapped;
|
|
};
|
|
};
|
|
} // namespace
|
|
|
|
llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>
|
|
clang::clangd::RealFileSystemProvider::getFileSystem() const {
|
|
// Avoid using memory-mapped files.
|
|
// FIXME: Try to use a similar approach in Sema instead of relying on
|
|
// propagation of the 'isVolatile' flag through all layers.
|
|
return new VolatileFileSystem(
|
|
llvm::vfs::createPhysicalFileSystem().release());
|
|
}
|
|
} // namespace clangd
|
|
} // namespace clang
|