[clangd] Support clang-tidy configuration in clangd.

Summary:
This patch adds some basic supports for clang-tidy configurations in clangd:
      - clangd will respect .clang-tidy configurations for each file
      - we don't aim to support all clang-tidy options in clangd, only a
        small subset of condfigurations (options related to which checks will be
        enabled) are supported.
      - add a `clang-tidy-checks` CLI option that can override options from
        .clang-tidy file

Reviewers: ilya-biryukov, sammccall

Reviewed By: sammccall

Subscribers: javed.absar, ioeric, MaskRay, jkorous, arphaman, kadircet, cfe-commits

Differential Revision: https://reviews.llvm.org/D55256

llvm-svn: 351792

7 files changed, 51 insertions, 18 deletions

diff --git a/clang-tools-extra/clangd/ClangdLSPServer.cpp b/clang-tools-extra/clangd/ClangdLSPServer.cpp
index d3ee6aa5ef6..e90ee916184 100644
--- a/clang-tools-extra/clangd/ClangdLSPServer.cpp
+++ b/clang-tools-extra/clangd/ClangdLSPServer.cpp
@@ -720,11 +720,13 @@ void ClangdLSPServer::onSymbolInfo(const TextDocumentPositionParams &Params,
 }
 
 ClangdLSPServer::ClangdLSPServer(class Transport &Transp,
+                                 const FileSystemProvider &FSProvider,
                                  const clangd::CodeCompleteOptions &CCOpts,
                                  llvm::Optional<Path> CompileCommandsDir,
                                  bool UseDirBasedCDB,
                                  const ClangdServer::Options &Opts)
-    : Transp(Transp), MsgHandler(new MessageHandler(*this)), CCOpts(CCOpts),
+    : Transp(Transp), MsgHandler(new MessageHandler(*this)),
+      FSProvider(FSProvider), CCOpts(CCOpts),
       SupportedSymbolKinds(defaultSymbolKinds()),
       SupportedCompletionItemKinds(defaultCompletionItemKinds()),
       UseDirBasedCDB(UseDirBasedCDB),
diff --git a/clang-tools-extra/clangd/ClangdLSPServer.h b/clang-tools-extra/clangd/ClangdLSPServer.h
index d84c298e4c9..40b9fc40e90 100644
--- a/clang-tools-extra/clangd/ClangdLSPServer.h
+++ b/clang-tools-extra/clangd/ClangdLSPServer.h
@@ -37,7 +37,8 @@ public:
   /// for compile_commands.json in all parent directories of each file.
   /// If UseDirBasedCDB is false, compile commands are not read from disk.
   // FIXME: Clean up signature around CDBs.
-  ClangdLSPServer(Transport &Transp, const clangd::CodeCompleteOptions &CCOpts,
+  ClangdLSPServer(Transport &Transp, const FileSystemProvider &FSProvider,
+                  const clangd::CodeCompleteOptions &CCOpts,
                   llvm::Optional<Path> CompileCommandsDir, bool UseDirBasedCDB,
                   const ClangdServer::Options &Opts);
   ~ClangdLSPServer();
@@ -128,7 +129,7 @@ private:
   void call(StringRef Method, llvm::json::Value Params);
   void notify(StringRef Method, llvm::json::Value Params);
 
-  RealFileSystemProvider FSProvider;
+  const FileSystemProvider &FSProvider;
   /// Options used for code completion
   clangd::CodeCompleteOptions CCOpts;
   /// Options used for diagnostics.
diff --git a/clang-tools-extra/clangd/ClangdServer.cpp b/clang-tools-extra/clangd/ClangdServer.cpp
index d70321da15c..5f494210ac3 100644
--- a/clang-tools-extra/clangd/ClangdServer.cpp
+++ b/clang-tools-extra/clangd/ClangdServer.cpp
@@ -105,6 +105,7 @@ ClangdServer::ClangdServer(const GlobalCompilationDatabase &CDB,
       DynamicIdx(Opts.BuildDynamicSymbolIndex
                      ? new FileIndex(Opts.HeavyweightDynamicSymbolIndex)
                      : nullptr),
+      ClangTidyOptProvider(Opts.ClangTidyOptProvider),
       WorkspaceRoot(Opts.WorkspaceRoot),
       PCHs(std::make_shared<PCHContainerOperations>()),
       // Pass a callback into `WorkScheduler` to extract symbols from a newly
@@ -140,13 +141,16 @@ ClangdServer::ClangdServer(const GlobalCompilationDatabase &CDB,
 
 void ClangdServer::addDocument(PathRef File, llvm::StringRef Contents,
                                WantDiagnostics WantDiags) {
+  tidy::ClangTidyOptions Options = tidy::ClangTidyOptions::getDefaults();
+  if (ClangTidyOptProvider)
+    Options = ClangTidyOptProvider->getOptions(File);
   // FIXME: some build systems like Bazel will take time to preparing
   // environment to build the file, it would be nice if we could emit a
   // "PreparingBuild" status to inform users, it is non-trivial given the
   // current implementation.
-  WorkScheduler.update(File,
-                       ParseInputs{getCompileCommand(File),
-                                   FSProvider.getFileSystem(), Contents.str()},
+  WorkScheduler.update(File, ParseInputs{getCompileCommand(File),
+                                         FSProvider.getFileSystem(),
+                                         Contents.str(), Options},
                        WantDiags);
 }
 
diff --git a/clang-tools-extra/clangd/ClangdServer.h b/clang-tools-extra/clangd/ClangdServer.h
index 20874c4bc0b..dc9581b504d 100644
--- a/clang-tools-extra/clangd/ClangdServer.h
+++ b/clang-tools-extra/clangd/ClangdServer.h
@@ -9,6 +9,7 @@
 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_CLANGDSERVER_H
 #define LLVM_CLANG_TOOLS_EXTRA_CLANGD_CLANGDSERVER_H
 
+#include "../clang-tidy/ClangTidyOptions.h"
 #include "Cancellation.h"
 #include "ClangdUnit.h"
 #include "CodeComplete.h"
@@ -92,6 +93,13 @@ public:
     /// If set, use this index to augment code completion results.
     SymbolIndex *StaticIndex = nullptr;
 
+    /// If set, enable clang-tidy in clangd, used to get clang-tidy
+    /// configurations for a particular file.
+    /// Clangd supports only a small subset of ClangTidyOptions, these options
+    /// (Checks, CheckOptions) are about which clang-tidy checks will be
+    /// enabled.
+    tidy::ClangTidyOptionsProvider *ClangTidyOptProvider = nullptr;
+
     /// Clangd's workspace root. Relevant for "workspace" operations not bound
     /// to a particular file.
     /// FIXME: If not set, should use the current working directory.
@@ -257,6 +265,9 @@ private:
   // Storage for merged views of the various indexes.
   std::vector<std::unique_ptr<SymbolIndex>> MergedIdx;
 
+  // The provider used to provide a clang-tidy option for a specific file.
+  tidy::ClangTidyOptionsProvider *ClangTidyOptProvider = nullptr;
+
   // GUARDED_BY(CachedCompletionFuzzyFindRequestMutex)
   llvm::StringMap<llvm::Optional<FuzzyFindRequest>>
       CachedCompletionFuzzyFindRequestByFile;
diff --git a/clang-tools-extra/clangd/ClangdUnit.cpp b/clang-tools-extra/clangd/ClangdUnit.cpp
index f7b8b731e12..268f7d1bbb4 100644
--- a/clang-tools-extra/clangd/ClangdUnit.cpp
+++ b/clang-tools-extra/clangd/ClangdUnit.cpp
@@ -132,6 +132,9 @@ public:
                      CompilerInstance &Clang) {
     auto &PP = Clang.getPreprocessor();
     auto *ExistingCallbacks = PP.getPPCallbacks();
+    // No need to replay events if nobody is listening.
+    if (!ExistingCallbacks)
+      return;
     PP.addPPCallbacks(std::unique_ptr<PPCallbacks>(
         new ReplayPreamble(Includes, ExistingCallbacks,
                            Clang.getSourceManager(), PP, Clang.getLangOpts())));
@@ -227,7 +230,8 @@ ParsedAST::build(std::unique_ptr<CompilerInvocation> CI,
                  std::shared_ptr<const PreambleData> Preamble,
                  std::unique_ptr<llvm::MemoryBuffer> Buffer,
                  std::shared_ptr<PCHContainerOperations> PCHs,
-                 llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS) {
+                 llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS,
+                 const tidy::ClangTidyOptions &ClangTidyOpts) {
   assert(CI);
   // Command-line parsing sets DisableFree to true by default, but we don't want
   // to leak memory in clangd.
@@ -264,15 +268,8 @@ ParsedAST::build(std::unique_ptr<CompilerInvocation> CI,
     tidy::ClangTidyCheckFactories CTFactories;
     for (const auto &E : tidy::ClangTidyModuleRegistry::entries())
       E.instantiate()->addCheckFactories(CTFactories);
-    auto CTOpts = tidy::ClangTidyOptions::getDefaults();
-    // FIXME: this needs to be configurable, and we need to support .clang-tidy
-    // files and other options providers.
-    // These checks exercise the matcher- and preprocessor-based hooks.
-    CTOpts.Checks = "bugprone-sizeof-expression,"
-                    "bugprone-macro-repeated-side-effects,"
-                    "modernize-deprecated-headers";
     CTContext.emplace(llvm::make_unique<tidy::DefaultOptionsProvider>(
-        tidy::ClangTidyGlobalOptions(), CTOpts));
+        tidy::ClangTidyGlobalOptions(), ClangTidyOpts));
     CTContext->setDiagnosticsEngine(&Clang->getDiagnostics());
     CTContext->setASTContext(&Clang->getASTContext());
     CTContext->setCurrentFile(MainInput.getFile());
@@ -538,7 +535,7 @@ buildAST(PathRef FileName, std::unique_ptr<CompilerInvocation> Invocation,
   return ParsedAST::build(llvm::make_unique<CompilerInvocation>(*Invocation),
                           Preamble,
                           llvm::MemoryBuffer::getMemBufferCopy(Inputs.Contents),
-                          PCHs, std::move(VFS));
+                          PCHs, std::move(VFS), Inputs.ClangTidyOpts);
 }
 
 SourceLocation getBeginningOfIdentifier(ParsedAST &Unit, const Position &Pos,
diff --git a/clang-tools-extra/clangd/ClangdUnit.h b/clang-tools-extra/clangd/ClangdUnit.h
index abcefdb6bf6..3a4841d7080 100644
--- a/clang-tools-extra/clangd/ClangdUnit.h
+++ b/clang-tools-extra/clangd/ClangdUnit.h
@@ -9,6 +9,7 @@
 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_CLANGDUNIT_H
 #define LLVM_CLANG_TOOLS_EXTRA_CLANGD_CLANGDUNIT_H
 
+#include "../clang-tidy/ClangTidyOptions.h"
 #include "Diagnostics.h"
 #include "FS.h"
 #include "Function.h"
@@ -64,6 +65,7 @@ struct ParseInputs {
   tooling::CompileCommand CompileCommand;
   IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS;
   std::string Contents;
+  tidy::ClangTidyOptions ClangTidyOpts;
 };
 
 /// Stores and provides access to parsed AST.
@@ -76,7 +78,8 @@ public:
         std::shared_ptr<const PreambleData> Preamble,
         std::unique_ptr<llvm::MemoryBuffer> Buffer,
         std::shared_ptr<PCHContainerOperations> PCHs,
-        IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS);
+        IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS,
+        const tidy::ClangTidyOptions &ClangTidyOpts);
 
   ParsedAST(ParsedAST &&Other);
   ParsedAST &operator=(ParsedAST &&Other);
diff --git a/clang-tools-extra/clangd/tool/ClangdMain.cpp b/clang-tools-extra/clangd/tool/ClangdMain.cpp
index 80f3f45e672..c969a5b7cfb 100644
--- a/clang-tools-extra/clangd/tool/ClangdMain.cpp
+++ b/clang-tools-extra/clangd/tool/ClangdMain.cpp
@@ -201,6 +201,12 @@ static llvm::cl::opt<bool> EnableFunctionArgSnippets(
                    "placeholders for method parameters."),
     llvm::cl::init(CodeCompleteOptions().EnableFunctionArgSnippets));
 
+static llvm::cl::opt<std::string> ClangTidyChecks(
+    "clang-tidy-checks",
+    llvm::cl::desc("List of clang-tidy checks to run (this will overrides "
+                   ".clang-tidy files)"),
+    llvm::cl::init(""), llvm::cl::Hidden);
+
 namespace {
 
 /// \brief Supports a test URI scheme with relaxed constraints for lit tests.
@@ -408,6 +414,7 @@ int main(int argc, char *argv[]) {
   CCOpts.EnableFunctionArgSnippets = EnableFunctionArgSnippets;
   CCOpts.AllScopes = AllScopesCompletion;
 
+  RealFileSystemProvider FSProvider;
   // Initialize and run ClangdLSPServer.
   // Change stdin to binary to not lose \r\n on windows.
   llvm::sys::ChangeStdinToBinary();
@@ -427,8 +434,16 @@ int main(int argc, char *argv[]) {
         PrettyPrint, InputStyle);
   }
 
+  // Create an empty clang-tidy option.
+  auto OverrideClangTidyOptions = tidy::ClangTidyOptions::getDefaults();
+  OverrideClangTidyOptions.Checks = ClangTidyChecks;
+  tidy::FileOptionsProvider ClangTidyOptProvider(
+      tidy::ClangTidyGlobalOptions(),
+      /* Default */ tidy::ClangTidyOptions::getDefaults(),
+      /* Override */ OverrideClangTidyOptions, FSProvider.getFileSystem());
+  Opts.ClangTidyOptProvider = &ClangTidyOptProvider;
   ClangdLSPServer LSPServer(
-      *TransportLayer, CCOpts, CompileCommandsDirPath,
+      *TransportLayer, FSProvider, CCOpts, CompileCommandsDirPath,
       /*UseDirBasedCDB=*/CompileArgsFrom == FilesystemCompileArgs, Opts);
   llvm::set_thread_name("clangd.main");
   return LSPServer.run() ? 0