[clangd] Retire clang-tidy-checks flag.

[njames93]

Summary

In clangd-12 the ability to override what clang tidy checks should run was moved into config.
For the 13 release its a wise progression to remove the command line option for this.

[njames93]

Ping? It would be nice to get this fix in the release branch.

[sammccall]

I think we should have the config mechanism available for one release cycle before removing the old one.

So I think it's fine to retire the flag but we shouldn't pick this into the 12 release branch.

[njames93]

In D96508#2559936, @sammccall wrote:

I think we should have the config mechanism available for one release cycle before removing the old one.

So I think it's fine to retire the flag but we shouldn't pick this into the 12 release branch.

I definitely agree this retiring should be for the next release cycle, I didn't think we should try and cherry pick this. I just happened to ping the wrong patch

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

 
 opt<bool> EnableClangTidy{
     "clang-tidy",
     cat(Features),
     desc("Enable clang-tidy diagnostics"),
     init(true),
 };
 
-opt<std::string> ClangTidyChecks{
-    "clang-tidy-checks",
-    cat(Features),
-    desc("List of clang-tidy checks to run (this will override "
-         ".clang-tidy files). Only meaningful when -clang-tidy flag is on"),
-    init(""),
-};
-
 opt<CodeCompleteOptions::CodeCompletionParse> CodeCompletionParse{
     "completion-parse",
     cat(Features),
     desc("Whether the clang-parser is used for code-completion"),
     values(clEnumValN(CodeCompleteOptions::AlwaysParse, "always",
                       "Block until the parser can be used"),
            clEnumValN(CodeCompleteOptions::ParseIfReady, "auto",
                       "Use text-based completion if the parser "

 };
 
 RetiredFlag<bool> EnableIndex("index");
 RetiredFlag<bool> SuggestMissingIncludes("suggest-missing-includes");
 RetiredFlag<bool> RecoveryAST("recovery-ast");
 RetiredFlag<bool> RecoveryASTType("recovery-ast-type");
 RetiredFlag<bool> AsyncPreamble("async-preamble");
 RetiredFlag<bool> CollectMainFileRefs("collect-main-file-refs");
+RetiredFlag<std::string> ClangTidyChecks("clang-tidy-checks");
 
 opt<int> LimitResults{
     "limit-results",
     cat(Features),
     desc("Limit the number of results returned by clangd. "
          "0 means no limit (default=100)"),
     init(100),
 };
#endif
   TidyProvider ClangTidyOptProvider;
   if (EnableClangTidy) {
     std::vector<TidyProvider> Providers;
     Providers.reserve(4 + EnableConfig);
     Providers.push_back(provideEnvironment());
     Providers.push_back(provideClangTidyFiles(TFS));
     if (EnableConfig)
       Providers.push_back(provideClangdConfig());
-    if (!ClangTidyChecks.empty())
-      Providers.push_back(addTidyChecks(ClangTidyChecks));
-    else
-      Providers.push_back(provideDefaultChecks());
     Providers.push_back(disableUnusableChecks());
     ClangTidyOptProvider = combine(std::move(Providers));
     Opts.ClangTidyProvider = ClangTidyOptProvider;
   }
   Opts.QueryDriverGlobs = std::move(QueryDriverGlobs);
   Opts.TweakFilter = [&](const Tweak &T) {
     if (T.hidden() && !HiddenFeatures)
       return false;