Support empty cacheDirectory and fix cache load

src/clang_complete.cc

@@ -561,7 +561,6 @@ void CompletionMain(ClangCompleteManager *completion_manager) {
         BuildCompilerInvocation(session->file.args, session->FS);
     if (!CI)
       continue;
-    CI->getDiagnosticOpts().IgnoreWarnings = true;
     clang::CodeCompleteOptions CCOpts;
     CCOpts.IncludeBriefComments = true;
 #if LLVM_VERSION_MAJOR >= 7
@@ -600,8 +599,6 @@ void DiagnosticMain(ClangCompleteManager *manager) {
     // Fetching the completion request blocks until we have a request.
     ClangCompleteManager::DiagnosticRequest request =
         manager->diagnostic_request_.Dequeue();
-    if (!g_config->diagnostics.onChange)
-      continue;
     std::string path = request.document.uri.GetPath();
 
     std::shared_ptr<CompletionSession> session = manager->TryGetSession(
@@ -611,7 +608,8 @@ void DiagnosticMain(ClangCompleteManager *manager) {
         BuildCompilerInvocation(session->file.args, session->FS);
     if (!CI)
       continue;
-    CI->getLangOpts()->SpellChecking = true;
+    CI->getDiagnosticOpts().IgnoreWarnings = false;
+    CI->getLangOpts()->SpellChecking = g_config->diagnostics.spellChecking;
     StoreDiags DC;
     WorkingFiles::Snapshot snapshot =
         manager->working_files_->AsSnapshot({StripFileType(path)});
@@ -668,6 +666,7 @@ void CompletionSession::BuildPreamble(CompilerInvocation &CI) {
   auto Bounds = ComputePreambleBounds(*CI.getLangOpts(), Buf.get(), 0);
   if (OldP && OldP->Preamble.CanReuse(CI, Buf.get(), Bounds, FS.get()))
     return;
+  CI.getDiagnosticOpts().IgnoreWarnings = false;
   CI.getFrontendOpts().SkipFunctionBodies = true;
   CI.getLangOpts()->RetainCommentsFromSystemHeaders = true;
   CI.getLangOpts()->CommentOpts.ParseAllComments = true;

src/clang_tu.cc

@@ -63,6 +63,7 @@ BuildCompilerInvocation(const std::vector<std::string> &args,
   std::unique_ptr<CompilerInvocation> CI =
       createInvocationFromCommandLine(cargs, Diags, VFS);
   if (CI) {
+    CI->getDiagnosticOpts().IgnoreWarnings = true;
     CI->getFrontendOpts().DisableFree = false;
     CI->getLangOpts()->SpellChecking = false;
   }

src/config.h

@@ -9,14 +9,7 @@
 
 /*
 The language client plugin needs to send initialization options in the
-`initialize` request to the ccls language server. The only required option is
-`cacheDirectory`, which is where index files will be stored.
-
-  {
-    "initializationOptions": {
-      "cacheDirectory": "/tmp/ccls"
-    }
-  }
+`initialize` request to the ccls language server.
 
 If necessary, the command line option --init can be used to override
 initialization options specified by the client. For example, in shell syntax:
@@ -35,6 +28,7 @@ struct Config {
   std::string compilationDatabaseDirectory;
   // Cache directory for indexed files, either absolute or relative to the
   // project root.
+  // If empty, cache will be stored in memory.
   std::string cacheDirectory = ".ccls-cache";
   // Cache serialization format.
   //
@@ -42,12 +36,14 @@ struct Config {
   // printed with jq.
   //
   // "binary" uses a compact binary serialization format.
-  // It is not schema-aware and you need to re-index whenever a struct
+  // It is not schema-aware and you need to re-index whenever an internal struct
   // member has changed.
   SerializeFormat cacheFormat = SerializeFormat::Binary;
 
   struct Clang {
     // Arguments that should be excluded, e.g. ["-fopenmp", "-Wall"]
+    //
+    // e.g. If your project is built by GCC and has an option thag clang does not understand.
     std::vector<std::string> excludeArgs;
 
     // Additional arguments to pass to clang.

src/file_consumer.h

@@ -33,6 +33,7 @@ struct VFS {
     int64_t timestamp;
     int owner;
     int stage;
+    bool loaded = false;
   };
   mutable std::unordered_map<std::string, State> state;
   mutable std::mutex mutex;

src/indexer.cc

@@ -39,7 +39,7 @@ struct IndexParam {
   std::unordered_map<llvm::sys::fs::UniqueID, std::string> SeenUniqueID;
   std::unordered_map<llvm::sys::fs::UniqueID, bool> UID2multi;
   std::unordered_map<std::string, FileContents> file_contents;
-  std::unordered_map<std::string, int64_t> file2write_time;
+  std::unordered_map<std::string, int64_t> file2mtime;
   struct DeclInfo {
     Usr usr;
     std::string short_name;
@@ -59,13 +59,7 @@ struct IndexParam {
     if (inserted) {
       std::string file_name = FileName(File);
       it->second = file_name;
-
-      // Set modification time.
-      std::optional<int64_t> write_time = LastWriteTime(file_name);
-      LOG_IF_S(ERROR, !write_time)
-          << "failed to fetch write time for " << file_name;
-      if (write_time)
-        file2write_time[file_name] = *write_time;
+      file2mtime[file_name] = File.getModificationTime();
     }
   }
 
@@ -1282,13 +1276,13 @@ Index(VFS *vfs, const std::string &opt_wdir, const std::string &file,
       Uniquify(it.second.uses);
 
     // Update file contents and modification time.
-    entry->last_write_time = param.file2write_time[entry->path];
+    entry->mtime = param.file2mtime[entry->path];
 
     // Update dependencies for the file. Do not include the file in its own
     // dependency set.
     for (auto &[_, path] : param.SeenUniqueID)
       if (path != entry->path && path != entry->import_file)
-        entry->dependencies[path] = param.file2write_time[path];
+        entry->dependencies[path] = param.file2mtime[path];
   }
 
   return result;

src/indexer.h

@@ -235,7 +235,8 @@ struct IndexFile {
   llvm::sys::fs::UniqueID UniqueID;
   std::string path;
   std::vector<std::string> args;
-  int64_t last_write_time = 0;
+  // This is unfortunately time_t as used by clang::FileEntry
+  int64_t mtime = 0;
   LanguageId language = LanguageId::C;
 
   // uid2lid_and_path is used to generate lid2path, but not serialized.

src/messages/ccls_freshenIndex.cc

@@ -57,7 +57,8 @@ struct Handler_CclsFreshenIndex : BaseMessageHandler<In_CclsFreshenIndex> {
       q.pop();
       need_index.insert(file->def->path);
 
-      std::optional<int64_t> write_time = LastWriteTime(file->def->path);
+      std::optional<int64_t> write_time =
+          pipeline::LastWriteTime(file->def->path);
       if (!write_time)
         continue;
       {

src/messages/initialize.cc

@@ -426,10 +426,7 @@ struct Handler_Initialize : BaseMessageHandler<In_InitializeRequest> {
       Reflect(json_writer, *g_config);
       LOG_S(INFO) << "initializationOptions: " << output.GetString();
 
-      if (g_config->cacheDirectory.empty()) {
-        LOG_S(ERROR) << "cacheDirectory cannot be empty.";
-        exit(1);
-      } else {
+      if (g_config->cacheDirectory.size()) {
         g_config->cacheDirectory = NormalizePath(g_config->cacheDirectory);
         EnsureEndsInSlash(g_config->cacheDirectory);
       }
@@ -458,12 +455,14 @@ struct Handler_Initialize : BaseMessageHandler<In_InitializeRequest> {
     // Set project root.
     EnsureEndsInSlash(project_path);
     g_config->projectRoot = project_path;
-    // Create two cache directories for files inside and outside of the
-    // project.
-    sys::fs::create_directories(g_config->cacheDirectory +
-                                EscapeFileName(g_config->projectRoot));
-    sys::fs::create_directories(g_config->cacheDirectory + '@' +
-                                EscapeFileName(g_config->projectRoot));
+    if (g_config->cacheDirectory.size()) {
+      // Create two cache directories for files inside and outside of the
+      // project.
+      sys::fs::create_directories(g_config->cacheDirectory +
+        EscapeFileName(g_config->projectRoot));
+      sys::fs::create_directories(g_config->cacheDirectory + '@' +
+                                  EscapeFileName(g_config->projectRoot));
+    }
 
     diag_pub->Init();
     idx::Init();

src/messages/textDocument_didChange.cc

@@ -24,15 +24,17 @@ struct Handler_TextDocumentDidChange
   MethodType GetMethodType() const override { return kMethodType; }
 
   void Run(In_TextDocumentDidChange *request) override {
-    std::string path = request->params.textDocument.uri.GetPath();
-    working_files->OnChange(request->params);
+    const auto &params = request->params;
+    std::string path = params.textDocument.uri.GetPath();
+    working_files->OnChange(params);
     if (g_config->index.onChange) {
       Project::Entry entry = project->FindCompilationEntryForFile(path);
       pipeline::Index(entry.filename, entry.args, IndexMode::OnChange);
     }
-    clang_complete->NotifyEdit(path);
-    clang_complete->DiagnosticsUpdate(
-        request->params.textDocument.AsTextDocumentIdentifier());
+    clang_complete->NotifyView(path);
+    if (g_config->diagnostics.onChange)
+      clang_complete->DiagnosticsUpdate(
+          params.textDocument.AsTextDocumentIdentifier());
   }
 };
 REGISTER_MESSAGE_HANDLER(Handler_TextDocumentDidChange);

src/messages/textDocument_didOpen.cc

@@ -41,7 +41,7 @@ struct Handler_TextDocumentDidOpen
 
     WorkingFile *working_file = working_files->OnOpen(params.textDocument);
     if (std::optional<std::string> cached_file_contents =
-            pipeline::LoadCachedFileContents(path))
+            pipeline::LoadIndexedContent(path))
       working_file->SetIndexContent(*cached_file_contents);
 
     QueryFile *file = nullptr;

src/pipeline.cc

@@ -83,12 +83,18 @@ ThreadedQueue<Index_Request> *index_request;
 ThreadedQueue<IndexUpdate> *on_indexed;
 ThreadedQueue<Stdout_Request> *for_stdout;
 
+struct InMemoryIndexFile {
+  std::string content;
+  IndexFile index;
+};
+std::unordered_map<std::string, InMemoryIndexFile> g_index;
+
 bool CacheInvalid(VFS *vfs, IndexFile *prev, const std::string &path,
                   const std::vector<std::string> &args,
                   const std::optional<std::string> &from) {
   {
     std::lock_guard<std::mutex> lock(vfs->mutex);
-    if (prev->last_write_time < vfs->state[path].timestamp) {
+    if (prev->mtime < vfs->state[path].timestamp) {
       LOG_S(INFO) << "timestamp changed for " << path
                   << (from ? " (via " + *from + ")" : std::string());
       return true;
@@ -128,6 +134,13 @@ std::string GetCachePath(const std::string &source_file) {
 }
 
 std::unique_ptr<IndexFile> RawCacheLoad(const std::string &path) {
+  if (g_config->cacheDirectory.empty()) {
+    auto it = g_index.find(path);
+    if (it == g_index.end())
+      return nullptr;
+    return std::make_unique<IndexFile>(it->second.index);
+  }
+
   std::string cache_path = GetCachePath(path);
   std::optional<std::string> file_content = ReadContent(cache_path);
   std::optional<std::string> serialized_indexed_content =
@@ -255,7 +268,18 @@ bool Indexer_Parse(DiagnosticsPublisher *diag_pub, WorkingFiles *working_files,
 
   for (std::unique_ptr<IndexFile> &curr : indexes) {
     std::string path = curr->path;
-    if (!(vfs->Stamp(path, curr->last_write_time) || path == path_to_index))
+    bool do_update = path == path_to_index, loaded;
+    {
+      std::lock_guard<std::mutex> lock(vfs->mutex);
+      VFS::State &st = vfs->state[path];
+      if (st.timestamp < curr->mtime) {
+        st.timestamp = curr->mtime;
+        do_update = true;
+      }
+      loaded = st.loaded;
+      st.loaded = true;
+    }
+    if (!do_update)
       continue;
     if (std::string reason; !matcher.IsMatch(path, &reason)) {
       LOG_IF_S(INFO, loud) << "skip emitting and storing index of " << path << " for "
@@ -263,15 +287,22 @@ bool Indexer_Parse(DiagnosticsPublisher *diag_pub, WorkingFiles *working_files,
       continue;
     }
 
-    LOG_IF_S(INFO, loud) << "emit index for " << path;
-    prev = RawCacheLoad(path);
+    prev.reset();
+    if (loaded)
+      prev = RawCacheLoad(path);
 
-    // Write current index to disk if requested.
-    {
+    // Store current index.
+    LOG_IF_S(INFO, loud) << "store index for " << path << " (delta: " << !!prev
+                         << ")";
+    if (g_config->cacheDirectory.empty()) {
+      auto it = g_index.insert_or_assign(
+        path, InMemoryIndexFile{curr->file_contents, *curr});
+      std::string().swap(it.first->second.index.file_contents);
+    } else {
       std::string cache_path = GetCachePath(path);
       WriteToFile(cache_path, curr->file_contents);
       WriteToFile(AppendSerializationFormat(cache_path),
-                  Serialize(g_config->cacheFormat, *curr));
+        Serialize(g_config->cacheFormat, *curr));
     }
 
     vfs->Reset(path);
@@ -283,8 +314,6 @@ bool Indexer_Parse(DiagnosticsPublisher *diag_pub, WorkingFiles *working_files,
 
     // Build delta update.
     IndexUpdate update = IndexUpdate::CreateDelta(prev.get(), curr.get());
-    LOG_IF_S(INFO, loud) << "store index for " << path << " (delta: " << !!prev
-                         << ")";
 
     on_indexed->PushBack(std::move(update),
                          request.mode != IndexMode::NonInteractive);
@@ -498,7 +527,20 @@ void Index(const std::string &path, const std::vector<std::string> &args,
   index_request->PushBack({path, args, mode, id}, mode != IndexMode::NonInteractive);
 }
 
-std::optional<std::string> LoadCachedFileContents(const std::string &path) {
+std::optional<int64_t> LastWriteTime(const std::string &path) {
+  sys::fs::file_status Status;
+  if (sys::fs::status(path, Status))
+    return {};
+  return sys::toTimeT(Status.getLastModificationTime());
+}
+
+std::optional<std::string> LoadIndexedContent(const std::string &path) {
+  if (g_config->cacheDirectory.empty()) {
+    auto it = g_index.find(path);
+    if (it == g_index.end())
+      return {};
+    return it->second.content;
+  }
   return ReadContent(GetCachePath(path));
 }
 

src/pipeline.hh

@@ -49,7 +49,8 @@ void MainLoop();
 void Index(const std::string &path, const std::vector<std::string> &args,
            IndexMode mode, lsRequestId id = {});
 
-std::optional<std::string> LoadCachedFileContents(const std::string& path);
-void WriteStdout(MethodType method, lsBaseOutMessage& response);
-}
-}
+std::optional<int64_t> LastWriteTime(const std::string &path);
+std::optional<std::string> LoadIndexedContent(const std::string& path);
+void WriteStdout(MethodType method, lsBaseOutMessage &response);
+} // namespace pipeline
+} // namespace ccls

src/serializer.cc

@@ -297,7 +297,7 @@ bool ReflectMemberStart(Writer &visitor, IndexFile &value) {
 template <typename TVisitor> void Reflect(TVisitor &visitor, IndexFile &value) {
   REFLECT_MEMBER_START();
   if (!gTestOutputMode) {
-    REFLECT_MEMBER(last_write_time);
+    REFLECT_MEMBER(mtime);
     REFLECT_MEMBER(language);
     REFLECT_MEMBER(lid2path);
     REFLECT_MEMBER(import_file);

src/utils.cc

@@ -3,13 +3,13 @@
 
 #include "utils.h"
 
-#include "filesystem.hh"
-using namespace llvm;
 #include "log.hh"
 #include "platform.h"
 
 #include <siphash.h>
 
+#include "llvm/ADT/StringRef.h"
+
 #include <algorithm>
 #include <assert.h>
 #include <ctype.h>
@@ -17,7 +17,6 @@ using namespace llvm;
 #include <functional>
 #include <string.h>
 #include <unordered_map>
-using namespace std::placeholders;
 
 void TrimInPlace(std::string &s) {
   auto f = [](char c) { return !isspace(c); };
@@ -57,7 +56,8 @@ bool StartsWith(std::string_view s, std::string_view prefix) {
 }
 
 bool EndsWithAny(std::string_view s, const std::vector<std::string> &ss) {
-  return std::any_of(ss.begin(), ss.end(), std::bind(EndsWith, s, _1));
+  return std::any_of(ss.begin(), ss.end(),
+                     std::bind(EndsWith, s, std::placeholders::_1));
 }
 
 bool FindAnyPartial(const std::string &value,
@@ -135,13 +135,6 @@ void WriteToFile(const std::string &filename, const std::string &content) {
   fclose(f);
 }
 
-std::optional<int64_t> LastWriteTime(const std::string &filename) {
-  sys::fs::file_status Status;
-  if (sys::fs::status(filename, Status))
-    return {};
-  return Status.getLastModificationTime().time_since_epoch().count();
-}
-
 // Find discontinous |search| in |content|.
 // Return |found| and the count of skipped chars before found.
 int ReverseSubseqMatch(std::string_view pat, std::string_view text,

src/utils.h

@@ -63,7 +63,6 @@ std::string EscapeFileName(std::string path);
 
 std::optional<std::string> ReadContent(const std::string &filename);
 void WriteToFile(const std::string &filename, const std::string &content);
-std::optional<int64_t> LastWriteTime(const std::string &filename);
 
 int ReverseSubseqMatch(std::string_view pat, std::string_view text,
                        int case_sensitivity);