Misc changes to project

* Better LanguageId detection with clangDriver (e.g. .cu -> types::TY_CUDA)
* fallback when there is no .ccls or compile_commands.json

Also Hide clangTooling options from --help

CMakeLists.txt

@@ -188,7 +188,6 @@ target_sources(ccls PRIVATE
   src/include_complete.cc
   src/indexer.cc
   src/method.cc
-  src/language.cc
   src/log.cc
   src/lsp.cc
   src/match.cc

src/indexer.h

@@ -3,7 +3,6 @@
 
 #pragma once
 
-#include "language.h"
 #include "lsp.h"
 #include "lsp_diagnostic.h"
 #include "maybe.h"
@@ -23,6 +22,7 @@
 #include <vector>
 
 using Usr = uint64_t;
+enum class LanguageId;
 
 struct SymbolIdx {
   Usr usr;

src/language.cc

@@ -1,33 +0,0 @@
-// Copyright 2017-2018 ccls Authors
-// SPDX-License-Identifier: Apache-2.0
-
-#include "language.h"
-
-#include "utils.h"
-
-LanguageId SourceFileLanguage(std::string_view path) {
-  if (EndsWith(path, ".c"))
-    return LanguageId::C;
-  else if (EndsWith(path, ".cpp") || EndsWith(path, ".cc"))
-    return LanguageId::Cpp;
-  else if (EndsWith(path, ".mm"))
-    return LanguageId::ObjCpp;
-  else if (EndsWith(path, ".m"))
-    return LanguageId::ObjC;
-  return LanguageId::Unknown;
-}
-
-const char *LanguageIdentifier(LanguageId lang) {
-  switch (lang) {
-  case LanguageId::C:
-    return "c";
-  case LanguageId::Cpp:
-    return "cpp";
-  case LanguageId::ObjC:
-    return "objective-c";
-  case LanguageId::ObjCpp:
-    return "objective-cpp";
-  default:
-    return "";
-  }
-}

src/language.h

@@ -1,17 +0,0 @@
-// Copyright 2017-2018 ccls Authors
-// SPDX-License-Identifier: Apache-2.0
-
-#pragma once
-
-#include "serializer.h"
-
-#include <string_view>
-
-// Used to identify the language at a file level. The ordering is important, as
-// a file previously identified as `C`, will be changed to `Cpp` if it
-// encounters a c++ declaration.
-enum class LanguageId { Unknown = -1, C = 0, Cpp = 1, ObjC = 2, ObjCpp = 3 };
-MAKE_REFLECT_TYPE_PROXY(LanguageId);
-
-LanguageId SourceFileLanguage(std::string_view path);
-const char *LanguageIdentifier(LanguageId lang);

src/lsp.h

@@ -334,3 +334,9 @@ struct Out_LocationList : public lsOutMessage<Out_LocationList> {
   std::vector<lsLocation> result;
 };
 MAKE_REFLECT_STRUCT(Out_LocationList, jsonrpc, id, result);
+
+// Used to identify the language at a file level. The ordering is important, as
+// a file previously identified as `C`, will be changed to `Cpp` if it
+// encounters a c++ declaration.
+enum class LanguageId { Unknown = -1, C = 0, Cpp = 1, ObjC = 2, ObjCpp = 3 };
+MAKE_REFLECT_TYPE_PROXY(LanguageId);

src/main.cc

@@ -30,17 +30,19 @@ using namespace llvm::cl;
 std::string g_init_options;
 
 namespace {
-opt<bool> opt_help("h", desc("Alias for -help"));
-opt<int> opt_verbose("v", desc("verbosity"), init(0));
+OptionCategory C("ccls options");
+
+opt<bool> opt_help("h", desc("Alias for -help"), cat(C));
+opt<int> opt_verbose("v", desc("verbosity"), init(0), cat(C));
 opt<std::string> opt_test_index("test-index", ValueOptional, init("!"),
-                                desc("run index tests"));
+                                desc("run index tests"), cat(C));
 
-opt<std::string> opt_init("init", desc("extra initialization options"));
-opt<std::string> opt_log_file("log-file", desc("log"), value_desc("filename"));
+opt<std::string> opt_init("init", desc("extra initialization options in JSON"),
+                          cat(C));
+opt<std::string> opt_log_file("log-file", desc("log"), value_desc("filename"),
+                              cat(C));
 opt<std::string> opt_log_file_append("log-file-append", desc("log"),
-                                     value_desc("filename"));
-
-list<std::string> opt_extra(Positional, ZeroOrMore, desc("extra"));
+                                     value_desc("filename"), cat(C));
 
 void CloseLog() { fclose(ccls::log::file); }
 
@@ -50,6 +52,10 @@ int main(int argc, char **argv) {
   TraceMe();
   sys::PrintStackTraceOnErrorSignal(argv[0]);
 
+  for (auto &I : TopLevelSubCommand->OptionsMap)
+    if (I.second->Category != &C)
+      I.second->setHiddenFlag(ReallyHidden);
+
   ParseCommandLineOptions(argc, argv,
                           "C/C++/Objective-C language server\n\n"
                           "See more on https://github.com/MaskRay/ccls/wiki");

src/messages/textDocument_did.cc

@@ -115,7 +115,8 @@ struct Handler_TextDocumentDidOpen
 
     // Submit new index request if it is not a header file or there is no
     // pending index request.
-    if (SourceFileLanguage(path) != LanguageId::Unknown ||
+    std::pair<LanguageId, bool> lang = lookupExtension(path);
+    if ((lang.first != LanguageId::Unknown && !lang.second) ||
         !pipeline::pending_index_requests)
       pipeline::Index(path, args, IndexMode::Normal);
 

src/messages/textDocument_hover.cc

@@ -9,6 +9,18 @@ using namespace ccls;
 namespace {
 MethodType kMethodType = "textDocument/hover";
 
+const char *LanguageIdentifier(LanguageId lang) {
+  switch (lang) {
+  // clang-format off
+  case LanguageId::C: return "c";
+  case LanguageId::Cpp: return "cpp";
+  case LanguageId::ObjC: return "objective-c";
+  case LanguageId::ObjCpp: return "objective-cpp";
+  default: return "";
+  // clang-format on
+  }
+}
+
 // Returns the hover or detailed name for `sym`, if any.
 std::pair<std::optional<lsMarkedString>, std::optional<lsMarkedString>>
 GetHover(DB *db, LanguageId lang, SymbolRef sym, int file_id) {

src/project.cc

@@ -4,7 +4,6 @@
 #include "project.h"
 
 #include "filesystem.hh"
-#include "language.h"
 #include "log.hh"
 #include "match.h"
 #include "pipeline.hh"
@@ -15,6 +14,7 @@
 
 #include <clang/Driver/Compilation.h>
 #include <clang/Driver/Driver.h>
+#include <clang/Driver/Types.h>
 #include <clang/Frontend/CompilerInstance.h>
 #include <clang/Tooling/CompilationDatabase.h>
 #include <llvm/ADT/STLExtras.h>
@@ -35,6 +35,25 @@ using namespace ccls;
 using namespace clang;
 using namespace llvm;
 
+std::pair<LanguageId, bool> lookupExtension(std::string_view filename) {
+  using namespace clang::driver;
+  auto I = types::lookupTypeForExtension(
+      sys::path::extension({filename.data(), filename.size()}).substr(1));
+  bool header = I == types::TY_CHeader || I == types::TY_CXXHeader ||
+                I == types::TY_ObjCXXHeader;
+  bool objc = types::isObjC(I);
+  LanguageId ret;
+  if (types::isCXX(I))
+    ret = objc ? LanguageId::ObjCpp : LanguageId::Cpp;
+  else if (objc)
+    ret = LanguageId::ObjC;
+  else if (I == types::TY_C || I == types::TY_CHeader)
+    ret = LanguageId::C;
+  else
+    ret = LanguageId::Unknown;
+  return {ret, header};
+}
+
 namespace {
 
 enum class ProjectMode { CompileCommandsJson, DotCcls, ExternalCommand };
@@ -64,7 +83,7 @@ struct ProjectProcessor {
     // Expand %c %cpp %clang
     std::vector<const char *> args;
     args.reserve(entry.args.size() + g_config->clang.extraArgs.size() + 1);
-    const LanguageId lang = SourceFileLanguage(entry.filename);
+    const LanguageId lang = lookupExtension(entry.filename).first;
     for (const char *arg : entry.args) {
       if (strncmp(arg, "%c ", 3) == 0) {
         if (lang == LanguageId::C)
@@ -86,7 +105,7 @@ struct ProjectProcessor {
     size_t hash = std::hash<std::string>{}(entry.directory);
     for (auto &arg : args) {
       if (arg[0] != '-' && EndsWith(arg, base_name)) {
-        const LanguageId lang = SourceFileLanguage(arg);
+        LanguageId lang = lookupExtension(arg).first;
         if (lang != LanguageId::Unknown) {
           hash_combine(hash, size_t(lang));
           continue;
@@ -170,12 +189,6 @@ ReadCompilerArgumentsFromFile(const std::string &path) {
 std::vector<Project::Entry> LoadFromDirectoryListing(ProjectConfig *config) {
   std::vector<Project::Entry> result;
   config->mode = ProjectMode::DotCcls;
-  SmallString<256> Path;
-  sys::path::append(Path, config->root, ".ccls");
-  LOG_IF_S(WARNING, !sys::fs::exists(Path) && g_config->clang.extraArgs.empty())
-      << "ccls has no clang arguments. Use either "
-         "compile_commands.json or .ccls, See ccls README for "
-         "more information.";
 
   std::unordered_map<std::string, std::vector<const char *>> folder_args;
   std::vector<std::string> files;
@@ -184,7 +197,8 @@ std::vector<Project::Entry> LoadFromDirectoryListing(ProjectConfig *config) {
   GetFilesInFolder(root, true /*recursive*/,
                    true /*add_folder_to_path*/,
                    [&folder_args, &files](const std::string &path) {
-                     if (SourceFileLanguage(path) != LanguageId::Unknown) {
+                     std::pair<LanguageId, bool> lang = lookupExtension(path);
+                     if (lang.first != LanguageId::Unknown && !lang.second) {
                        files.push_back(path);
                      } else if (sys::path::filename(path) == ".ccls") {
                        std::vector<const char *> args = ReadCompilerArgumentsFromFile(path);
@@ -235,14 +249,13 @@ std::vector<Project::Entry>
 LoadEntriesFromDirectory(ProjectConfig *project,
                          const std::string &opt_compdb_dir) {
   // If there is a .ccls file always load using directory listing.
-  SmallString<256> Path;
-  sys::path::append(Path, project->root, ".ccls");
-  if (sys::fs::exists(Path))
+  SmallString<256> Path, CclsPath;
+  sys::path::append(CclsPath, project->root, ".ccls");
+  if (sys::fs::exists(CclsPath))
     return LoadFromDirectoryListing(project);
 
   // If |compilationDatabaseCommand| is specified, execute it to get the compdb.
   std::string comp_db_dir;
-  Path.clear();
   if (g_config->compilationDatabaseCommand.empty()) {
     project->mode = ProjectMode::CompileCommandsJson;
     // Try to load compile_commands.json, but fallback to a project listing.
@@ -284,8 +297,8 @@ LoadEntriesFromDirectory(ProjectConfig *project,
 #endif
   }
   if (!CDB) {
-    LOG_S(WARNING) << "failed to load " << Path.c_str() << " " << err_msg;
-    return {};
+    LOG_S(WARNING) << "no .ccls or compile_commands.json . Consider adding one";
+    return LoadFromDirectoryListing(project);
   }
 
   LOG_S(INFO) << "loaded " << Path.c_str();

src/project.h

@@ -4,6 +4,7 @@
 #pragma once
 
 #include "config.h"
+#include "lsp.h"
 #include "method.h"
 
 #include <functional>
@@ -14,6 +15,8 @@
 
 struct WorkingFiles;
 
+std::pair<LanguageId, bool> lookupExtension(std::string_view filename);
+
 struct Project {
   struct Entry {
     std::string root;