[clangd] Retire some flags for uncontroversial, stable features.

And mark a couple to be retired afther the next release branch.

Differential Revision: https://reviews.llvm.org/D94727

Author: sam-mccall

clang-tools-extra/clangd/ClangdServer.cpp

@@ -146,7 +146,6 @@ ClangdServer::ClangdServer(const GlobalCompilationDatabase &CDB,
                                      Opts.CollectMainFileRefs)
                      : nullptr),
       ClangTidyProvider(Opts.ClangTidyProvider),
-      SuggestMissingIncludes(Opts.SuggestMissingIncludes),
       WorkspaceRoot(Opts.WorkspaceRoot),
       // Pass a callback into `WorkScheduler` to extract symbols from a newly
       // parsed file and rebuild the file index synchronously each time an AST
@@ -201,7 +200,6 @@ void ClangdServer::addDocument(PathRef File, llvm::StringRef Contents,
                                llvm::StringRef Version,
                                WantDiagnostics WantDiags, bool ForceRebuild) {
   ParseOptions Opts;
-  Opts.SuggestMissingIncludes = SuggestMissingIncludes;
 
   // Compile command is set asynchronously during update, as it can be slow.
   ParseInputs Inputs;

clang-tools-extra/clangd/ClangdServer.h

@@ -136,8 +136,6 @@ class ClangdServer {
         /*RebuildRatio=*/1,
     };
 
-    bool SuggestMissingIncludes = false;
-
     /// Clangd will execute compiler drivers matching one of these globs to
     /// fetch system include path.
     std::vector<std::string> QueryDriverGlobs;
@@ -376,10 +374,6 @@ class ClangdServer {
   // When set, provides clang-tidy options for a specific file.
   TidyProviderRef ClangTidyProvider;
 
-  // If this is true, suggest include insertion fixes for diagnostic errors that
-  // can be caused by missing includes (e.g. member access in incomplete type).
-  bool SuggestMissingIncludes = false;
-
   // GUARDED_BY(CachedCompletionFuzzyFindRequestMutex)
   llvm::StringMap<llvm::Optional<FuzzyFindRequest>>
       CachedCompletionFuzzyFindRequestByFile;

clang-tools-extra/clangd/Compiler.h

@@ -37,7 +37,7 @@ class IgnoreDiagnostics : public DiagnosticConsumer {
 
 // Options to run clang e.g. when parsing AST.
 struct ParseOptions {
-  bool SuggestMissingIncludes = false;
+  // (empty at present, formerly controlled recovery AST, include-fixer etc)
 };
 
 /// Information required to run clang, e.g. to parse AST or do code completion.

clang-tools-extra/clangd/ParsedAST.cpp

@@ -351,8 +351,7 @@ ParsedAST::build(llvm::StringRef Filename, const ParseInputs &Inputs,
   // (e.g. incomplete type) and attach include insertion fixes to diagnostics.
   llvm::Optional<IncludeFixer> FixIncludes;
   auto BuildDir = VFS->getCurrentWorkingDirectory();
-  if (Inputs.Opts.SuggestMissingIncludes && Inputs.Index &&
-      !BuildDir.getError()) {
+  if (Inputs.Index && !BuildDir.getError()) {
     auto Style = getFormatStyleForFile(Filename, Inputs.Contents, *Inputs.TFS);
     auto Inserter = std::make_shared<IncludeInserter>(
         Filename, Inputs.Contents, Style, BuildDir.get(),

clang-tools-extra/clangd/tool/ClangdMain.cpp

@@ -80,8 +80,21 @@ OptionCategory CompileCommands("clangd compilation flags options");
 OptionCategory Features("clangd feature options");
 OptionCategory Misc("clangd miscellaneous options");
 OptionCategory Protocol("clangd protocol and logging options");
+OptionCategory Retired("clangd flags no longer in use");
 const OptionCategory *ClangdCategories[] = {&Features, &Protocol,
-                                            &CompileCommands, &Misc};
+                                            &CompileCommands, &Misc, &Retired};
+
+template <typename T> class RetiredFlag {
+  opt<T> Option;
+
+public:
+  RetiredFlag(llvm::StringRef Name)
+      : Option(Name, cat(Retired), desc("Obsolete flag, ignored"), Hidden,
+               llvm::cl::callback([Name](const T &) {
+                 llvm::errs()
+                     << "The flag `-" << Name << "` is obsolete and ignored.\n";
+               })) {}
+};
 
 enum CompileArgsFrom { LSPCompileArgs, FilesystemCompileArgs };
 opt<CompileArgsFrom> CompileArgsFrom{
@@ -267,15 +280,7 @@ opt<bool> IncludeIneligibleResults{
     Hidden,
 };
 
-opt<bool> EnableIndex{
-    "index",
-    cat(Features),
-    desc("Enable index-based features. By default, clangd maintains an index "
-         "built from symbols in opened files. Global index support needs to "
-         "enabled separatedly"),
-    init(true),
-    Hidden,
-};
+RetiredFlag<bool> EnableIndex("index");
 
 opt<int> LimitResults{
     "limit-results",
@@ -285,13 +290,7 @@ opt<int> LimitResults{
     init(100),
 };
 
-opt<bool> SuggestMissingIncludes{
-    "suggest-missing-includes",
-    cat(Features),
-    desc("Attempts to fix diagnostic errors caused by missing "
-         "includes using index"),
-    init(true),
-};
+RetiredFlag<bool> SuggestMissingIncludes("suggest-missing-includes");
 
 list<std::string> TweakList{
     "tweaks",
@@ -308,21 +307,8 @@ opt<bool> CrossFileRename{
     init(true),
 };
 
-opt<bool> RecoveryAST{
-    "recovery-ast",
-    cat(Features),
-    desc("Preserve expressions in AST for broken code."),
-    init(false),
-    Hidden,
-};
-
-opt<bool> RecoveryASTType{
-    "recovery-ast-type",
-    cat(Features),
-    desc("Preserve the type for recovery AST."),
-    init(false),
-    Hidden,
-};
+RetiredFlag<bool> RecoveryAST("recovery-ast");
+RetiredFlag<bool> RecoveryASTType("recovery-ast-type");
 
 opt<bool> FoldingRanges{
     "folding-ranges",
@@ -464,6 +450,7 @@ opt<bool> PrettyPrint{
     init(false),
 };
 
+// FIXME: retire this flag in llvm 13 release cycle.
 opt<bool> AsyncPreamble{
     "async-preamble",
     cat(Misc),
@@ -487,11 +474,13 @@ opt<bool> EnableConfig{
     init(true),
 };
 
+// FIXME: retire this flag in llvm 13 release cycle.
 opt<bool> CollectMainFileRefs{
     "collect-main-file-refs",
     cat(Misc),
     desc("Store references to main-file-only symbols in the index"),
     init(ClangdServer::Options().CollectMainFileRefs),
+    Hidden,
 };
 
 #if defined(__GLIBC__) && CLANGD_MALLOC_TRIM
@@ -770,12 +759,12 @@ clangd accepts flags on the commandline, and in the CLANGD_FLAGS environment var
   }
   if (!ResourceDir.empty())
     Opts.ResourceDir = ResourceDir;
-  Opts.BuildDynamicSymbolIndex = EnableIndex;
+  Opts.BuildDynamicSymbolIndex = true;
   Opts.CollectMainFileRefs = CollectMainFileRefs;
   std::vector<std::unique_ptr<SymbolIndex>> IdxStack;
   std::unique_ptr<SymbolIndex> StaticIdx;
   std::future<void> AsyncIndexLoad; // Block exit while loading the index.
-  if (EnableIndex && !IndexFile.empty()) {
+  if (!IndexFile.empty()) {
     // Load the index asynchronously. Meanwhile SwapIndex returns no results.
     SwapIndex *Placeholder;
     StaticIdx.reset(Placeholder = new SwapIndex(std::make_unique<MemIndex>()));
@@ -872,7 +861,6 @@ clangd accepts flags on the commandline, and in the CLANGD_FLAGS environment var
     Opts.ClangTidyProvider = ClangTidyOptProvider;
   }
   Opts.AsyncPreambleBuilds = AsyncPreamble;
-  Opts.SuggestMissingIncludes = SuggestMissingIncludes;
   Opts.QueryDriverGlobs = std::move(QueryDriverGlobs);
   Opts.TweakFilter = [&](const Tweak &T) {
     if (T.hidden() && !HiddenFeatures)

clang-tools-extra/clangd/unittests/TestTU.cpp

@@ -62,8 +62,6 @@ ParseInputs TestTU::inputs(MockFS &FS) const {
   if (ClangTidyProvider)
     Inputs.ClangTidyProvider = ClangTidyProvider;
   Inputs.Index = ExternalIndex;
-  if (Inputs.Index)
-    Inputs.Opts.SuggestMissingIncludes = true;
   return Inputs;
 }