llvm-project/clang-tools-extra/clangd/ClangdServer.cpp

485 lines
17 KiB
C++

//===--- ClangdServer.cpp - Main clangd server code --------------*- C++-*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===-------------------------------------------------------------------===//
#include "ClangdServer.h"
#include "clang/Format/Format.h"
#include "clang/Frontend/CompilerInstance.h"
#include "clang/Frontend/CompilerInvocation.h"
#include "clang/Tooling/CompilationDatabase.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/raw_ostream.h"
#include <future>
using namespace clang;
using namespace clang::clangd;
namespace {
class FulfillPromiseGuard {
public:
FulfillPromiseGuard(std::promise<void> &Promise) : Promise(Promise) {}
~FulfillPromiseGuard() { Promise.set_value(); }
private:
std::promise<void> &Promise;
};
std::vector<tooling::Replacement> formatCode(StringRef Code, StringRef Filename,
ArrayRef<tooling::Range> Ranges) {
// Call clang-format.
// FIXME: Don't ignore style.
format::FormatStyle Style = format::getLLVMStyle();
auto Result = format::reformat(Style, Code, Ranges, Filename);
return std::vector<tooling::Replacement>(Result.begin(), Result.end());
}
std::string getStandardResourceDir() {
static int Dummy; // Just an address in this process.
return CompilerInvocation::GetResourcesPath("clangd", (void *)&Dummy);
}
} // namespace
size_t clangd::positionToOffset(StringRef Code, Position P) {
size_t Offset = 0;
for (int I = 0; I != P.line; ++I) {
// FIXME: \r\n
// FIXME: UTF-8
size_t F = Code.find('\n', Offset);
if (F == StringRef::npos)
return 0; // FIXME: Is this reasonable?
Offset = F + 1;
}
return (Offset == 0 ? 0 : (Offset - 1)) + P.character;
}
/// Turn an offset in Code into a [line, column] pair.
Position clangd::offsetToPosition(StringRef Code, size_t Offset) {
StringRef JustBefore = Code.substr(0, Offset);
// FIXME: \r\n
// FIXME: UTF-8
int Lines = JustBefore.count('\n');
int Cols = JustBefore.size() - JustBefore.rfind('\n') - 1;
return {Lines, Cols};
}
Tagged<IntrusiveRefCntPtr<vfs::FileSystem>>
RealFileSystemProvider::getTaggedFileSystem(PathRef File) {
return make_tagged(vfs::getRealFileSystem(), VFSTag());
}
unsigned clangd::getDefaultAsyncThreadsCount() {
unsigned HardwareConcurrency = std::thread::hardware_concurrency();
// C++ standard says that hardware_concurrency()
// may return 0, fallback to 1 worker thread in
// that case.
if (HardwareConcurrency == 0)
return 1;
return HardwareConcurrency;
}
ClangdScheduler::ClangdScheduler(unsigned AsyncThreadsCount)
: RunSynchronously(AsyncThreadsCount == 0) {
if (RunSynchronously) {
// Don't start the worker thread if we're running synchronously
return;
}
Workers.reserve(AsyncThreadsCount);
for (unsigned I = 0; I < AsyncThreadsCount; ++I) {
Workers.push_back(std::thread([this]() {
while (true) {
UniqueFunction<void()> Request;
// Pick request from the queue
{
std::unique_lock<std::mutex> Lock(Mutex);
// Wait for more requests.
RequestCV.wait(Lock,
[this] { return !RequestQueue.empty() || Done; });
if (Done)
return;
assert(!RequestQueue.empty() && "RequestQueue was empty");
// We process requests starting from the front of the queue. Users of
// ClangdScheduler have a way to prioritise their requests by putting
// them to the either side of the queue (using either addToEnd or
// addToFront).
Request = std::move(RequestQueue.front());
RequestQueue.pop_front();
} // unlock Mutex
Request();
}
}));
}
}
ClangdScheduler::~ClangdScheduler() {
if (RunSynchronously)
return; // no worker thread is running in that case
{
std::lock_guard<std::mutex> Lock(Mutex);
// Wake up the worker thread
Done = true;
} // unlock Mutex
RequestCV.notify_all();
for (auto &Worker : Workers)
Worker.join();
}
ClangdServer::ClangdServer(GlobalCompilationDatabase &CDB,
DiagnosticsConsumer &DiagConsumer,
FileSystemProvider &FSProvider,
unsigned AsyncThreadsCount, bool SnippetCompletions,
clangd::Logger &Logger,
llvm::Optional<StringRef> ResourceDir)
: Logger(Logger), CDB(CDB), DiagConsumer(DiagConsumer),
FSProvider(FSProvider),
ResourceDir(ResourceDir ? ResourceDir->str() : getStandardResourceDir()),
PCHs(std::make_shared<PCHContainerOperations>()),
SnippetCompletions(SnippetCompletions), WorkScheduler(AsyncThreadsCount) {
}
void ClangdServer::setRootPath(PathRef RootPath) {
std::string NewRootPath = llvm::sys::path::convert_to_slash(
RootPath, llvm::sys::path::Style::posix);
if (llvm::sys::fs::is_directory(NewRootPath))
this->RootPath = NewRootPath;
}
std::future<void> ClangdServer::addDocument(PathRef File, StringRef Contents) {
DocVersion Version = DraftMgr.updateDraft(File, Contents);
auto TaggedFS = FSProvider.getTaggedFileSystem(File);
std::shared_ptr<CppFile> Resources = Units.getOrCreateFile(
File, ResourceDir, CDB, PCHs, TaggedFS.Value, Logger);
return scheduleReparseAndDiags(File, VersionedDraft{Version, Contents.str()},
std::move(Resources), std::move(TaggedFS));
}
std::future<void> ClangdServer::removeDocument(PathRef File) {
DraftMgr.removeDraft(File);
std::shared_ptr<CppFile> Resources = Units.removeIfPresent(File);
return scheduleCancelRebuild(std::move(Resources));
}
std::future<void> ClangdServer::forceReparse(PathRef File) {
auto FileContents = DraftMgr.getDraft(File);
assert(FileContents.Draft &&
"forceReparse() was called for non-added document");
auto TaggedFS = FSProvider.getTaggedFileSystem(File);
auto Recreated = Units.recreateFileIfCompileCommandChanged(
File, ResourceDir, CDB, PCHs, TaggedFS.Value, Logger);
// Note that std::future from this cleanup action is ignored.
scheduleCancelRebuild(std::move(Recreated.RemovedFile));
// Schedule a reparse.
return scheduleReparseAndDiags(File, std::move(FileContents),
std::move(Recreated.FileInCollection),
std::move(TaggedFS));
}
std::future<Tagged<std::vector<CompletionItem>>>
ClangdServer::codeComplete(PathRef File, Position Pos,
llvm::Optional<StringRef> OverridenContents,
IntrusiveRefCntPtr<vfs::FileSystem> *UsedFS) {
std::string Contents;
if (OverridenContents) {
Contents = *OverridenContents;
} else {
auto FileContents = DraftMgr.getDraft(File);
assert(FileContents.Draft &&
"codeComplete is called for non-added document");
Contents = std::move(*FileContents.Draft);
}
auto TaggedFS = FSProvider.getTaggedFileSystem(File);
if (UsedFS)
*UsedFS = TaggedFS.Value;
std::shared_ptr<CppFile> Resources = Units.getFile(File);
assert(Resources && "Calling completion on non-added file");
using PackagedTask =
std::packaged_task<Tagged<std::vector<CompletionItem>>()>;
// Remember the current Preamble and use it when async task starts executing.
// At the point when async task starts executing, we may have a different
// Preamble in Resources. However, we assume the Preamble that we obtain here
// is reusable in completion more often.
std::shared_ptr<const PreambleData> Preamble =
Resources->getPossiblyStalePreamble();
// A task that will be run asynchronously.
PackagedTask Task([=]() mutable { // 'mutable' to reassign Preamble variable.
if (!Preamble) {
// Maybe we built some preamble before processing this request.
Preamble = Resources->getPossiblyStalePreamble();
}
// FIXME(ibiryukov): even if Preamble is non-null, we may want to check
// both the old and the new version in case only one of them matches.
std::vector<CompletionItem> Result = clangd::codeComplete(
File, Resources->getCompileCommand(),
Preamble ? &Preamble->Preamble : nullptr, Contents, Pos, TaggedFS.Value,
PCHs, SnippetCompletions, Logger);
return make_tagged(std::move(Result), std::move(TaggedFS.Tag));
});
auto Future = Task.get_future();
// FIXME(ibiryukov): to reduce overhead for wrapping the same callable
// multiple times, ClangdScheduler should return future<> itself.
WorkScheduler.addToFront([](PackagedTask Task) { Task(); }, std::move(Task));
return Future;
}
Tagged<SignatureHelp>
ClangdServer::signatureHelp(PathRef File, Position Pos,
llvm::Optional<StringRef> OverridenContents,
IntrusiveRefCntPtr<vfs::FileSystem> *UsedFS) {
std::string DraftStorage;
if (!OverridenContents) {
auto FileContents = DraftMgr.getDraft(File);
assert(FileContents.Draft &&
"signatureHelp is called for non-added document");
DraftStorage = std::move(*FileContents.Draft);
OverridenContents = DraftStorage;
}
auto TaggedFS = FSProvider.getTaggedFileSystem(File);
if (UsedFS)
*UsedFS = TaggedFS.Value;
std::shared_ptr<CppFile> Resources = Units.getFile(File);
assert(Resources && "Calling signatureHelp on non-added file");
auto Preamble = Resources->getPossiblyStalePreamble();
auto Result = clangd::signatureHelp(File, Resources->getCompileCommand(),
Preamble ? &Preamble->Preamble : nullptr,
*OverridenContents, Pos, TaggedFS.Value,
PCHs, Logger);
return make_tagged(std::move(Result), TaggedFS.Tag);
}
std::vector<tooling::Replacement> ClangdServer::formatRange(PathRef File,
Range Rng) {
std::string Code = getDocument(File);
size_t Begin = positionToOffset(Code, Rng.start);
size_t Len = positionToOffset(Code, Rng.end) - Begin;
return formatCode(Code, File, {tooling::Range(Begin, Len)});
}
std::vector<tooling::Replacement> ClangdServer::formatFile(PathRef File) {
// Format everything.
std::string Code = getDocument(File);
return formatCode(Code, File, {tooling::Range(0, Code.size())});
}
std::vector<tooling::Replacement> ClangdServer::formatOnType(PathRef File,
Position Pos) {
// Look for the previous opening brace from the character position and
// format starting from there.
std::string Code = getDocument(File);
size_t CursorPos = positionToOffset(Code, Pos);
size_t PreviousLBracePos = StringRef(Code).find_last_of('{', CursorPos);
if (PreviousLBracePos == StringRef::npos)
PreviousLBracePos = CursorPos;
size_t Len = 1 + CursorPos - PreviousLBracePos;
return formatCode(Code, File, {tooling::Range(PreviousLBracePos, Len)});
}
std::string ClangdServer::getDocument(PathRef File) {
auto draft = DraftMgr.getDraft(File);
assert(draft.Draft && "File is not tracked, cannot get contents");
return *draft.Draft;
}
std::string ClangdServer::dumpAST(PathRef File) {
std::shared_ptr<CppFile> Resources = Units.getFile(File);
assert(Resources && "dumpAST is called for non-added document");
std::string Result;
Resources->getAST().get()->runUnderLock([&Result](ParsedAST *AST) {
llvm::raw_string_ostream ResultOS(Result);
if (AST) {
clangd::dumpAST(*AST, ResultOS);
} else {
ResultOS << "<no-ast>";
}
ResultOS.flush();
});
return Result;
}
Tagged<std::vector<Location>> ClangdServer::findDefinitions(PathRef File,
Position Pos) {
auto FileContents = DraftMgr.getDraft(File);
assert(FileContents.Draft &&
"findDefinitions is called for non-added document");
auto TaggedFS = FSProvider.getTaggedFileSystem(File);
std::shared_ptr<CppFile> Resources = Units.getFile(File);
assert(Resources && "Calling findDefinitions on non-added file");
std::vector<Location> Result;
Resources->getAST().get()->runUnderLock([Pos, &Result, this](ParsedAST *AST) {
if (!AST)
return;
Result = clangd::findDefinitions(*AST, Pos, Logger);
});
return make_tagged(std::move(Result), TaggedFS.Tag);
}
llvm::Optional<Path> ClangdServer::switchSourceHeader(PathRef Path) {
StringRef SourceExtensions[] = {".cpp", ".c", ".cc", ".cxx",
".c++", ".m", ".mm"};
StringRef HeaderExtensions[] = {".h", ".hh", ".hpp", ".hxx", ".inc"};
StringRef PathExt = llvm::sys::path::extension(Path);
// Lookup in a list of known extensions.
auto SourceIter =
std::find_if(std::begin(SourceExtensions), std::end(SourceExtensions),
[&PathExt](PathRef SourceExt) {
return SourceExt.equals_lower(PathExt);
});
bool IsSource = SourceIter != std::end(SourceExtensions);
auto HeaderIter =
std::find_if(std::begin(HeaderExtensions), std::end(HeaderExtensions),
[&PathExt](PathRef HeaderExt) {
return HeaderExt.equals_lower(PathExt);
});
bool IsHeader = HeaderIter != std::end(HeaderExtensions);
// We can only switch between extensions known extensions.
if (!IsSource && !IsHeader)
return llvm::None;
// Array to lookup extensions for the switch. An opposite of where original
// extension was found.
ArrayRef<StringRef> NewExts;
if (IsSource)
NewExts = HeaderExtensions;
else
NewExts = SourceExtensions;
// Storage for the new path.
SmallString<128> NewPath = StringRef(Path);
// Instance of vfs::FileSystem, used for file existence checks.
auto FS = FSProvider.getTaggedFileSystem(Path).Value;
// Loop through switched extension candidates.
for (StringRef NewExt : NewExts) {
llvm::sys::path::replace_extension(NewPath, NewExt);
if (FS->exists(NewPath))
return NewPath.str().str(); // First str() to convert from SmallString to
// StringRef, second to convert from StringRef
// to std::string
// Also check NewExt in upper-case, just in case.
llvm::sys::path::replace_extension(NewPath, NewExt.upper());
if (FS->exists(NewPath))
return NewPath.str().str();
}
return llvm::None;
}
std::future<void> ClangdServer::scheduleReparseAndDiags(
PathRef File, VersionedDraft Contents, std::shared_ptr<CppFile> Resources,
Tagged<IntrusiveRefCntPtr<vfs::FileSystem>> TaggedFS) {
assert(Contents.Draft && "Draft must have contents");
std::future<llvm::Optional<std::vector<DiagWithFixIts>>> DeferredRebuild =
Resources->deferRebuild(*Contents.Draft, TaggedFS.Value);
std::promise<void> DonePromise;
std::future<void> DoneFuture = DonePromise.get_future();
DocVersion Version = Contents.Version;
Path FileStr = File;
VFSTag Tag = TaggedFS.Tag;
auto ReparseAndPublishDiags =
[this, FileStr, Version,
Tag](std::future<llvm::Optional<std::vector<DiagWithFixIts>>>
DeferredRebuild,
std::promise<void> DonePromise) -> void {
FulfillPromiseGuard Guard(DonePromise);
auto CurrentVersion = DraftMgr.getVersion(FileStr);
if (CurrentVersion != Version)
return; // This request is outdated
auto Diags = DeferredRebuild.get();
if (!Diags)
return; // A new reparse was requested before this one completed.
// We need to serialize access to resulting diagnostics to avoid calling
// `onDiagnosticsReady` in the wrong order.
std::lock_guard<std::mutex> DiagsLock(DiagnosticsMutex);
DocVersion &LastReportedDiagsVersion = ReportedDiagnosticVersions[FileStr];
// FIXME(ibiryukov): get rid of '<' comparison here. In the current
// implementation diagnostics will not be reported after version counters'
// overflow. This should not happen in practice, since DocVersion is a
// 64-bit unsigned integer.
if (Version < LastReportedDiagsVersion)
return;
LastReportedDiagsVersion = Version;
DiagConsumer.onDiagnosticsReady(FileStr,
make_tagged(std::move(*Diags), Tag));
};
WorkScheduler.addToFront(std::move(ReparseAndPublishDiags),
std::move(DeferredRebuild), std::move(DonePromise));
return DoneFuture;
}
std::future<void>
ClangdServer::scheduleCancelRebuild(std::shared_ptr<CppFile> Resources) {
std::promise<void> DonePromise;
std::future<void> DoneFuture = DonePromise.get_future();
if (!Resources) {
// No need to schedule any cleanup.
DonePromise.set_value();
return DoneFuture;
}
std::future<void> DeferredCancel = Resources->deferCancelRebuild();
auto CancelReparses = [Resources](std::promise<void> DonePromise,
std::future<void> DeferredCancel) {
FulfillPromiseGuard Guard(DonePromise);
DeferredCancel.get();
};
WorkScheduler.addToFront(std::move(CancelReparses), std::move(DonePromise),
std::move(DeferredCancel));
return DoneFuture;
}
void ClangdServer::onFileEvent(const DidChangeWatchedFilesParams &Params) {
// FIXME: Do nothing for now. This will be used for indexing and potentially
// invalidating other caches.
}