[clangd] Add an option in the code to not display number of fixes

[ilya-biryukov]

Summary

Only to the APIs, which are used by our embedders.
We do not plan to add a user-facing option for this.

clang-tools-extra/trunk/clangd/Diagnostics.h

struct ClangdDiagnosticOptions {
   /// diagnostics that are sent to the client.
   bool EmbedFixesInDiagnostics = false;
 
   /// If true, Clangd uses an LSP extension to send the diagnostic's
   /// category to the client. The category typically describes the compilation
   /// stage during which the issue was produced, e.g. "Semantic Issue" or "Parse
   /// Issue".
   bool SendDiagnosticCategory = false;
+
+  /// If true, Clangd will add a number of available fixes to the diagnostic's
+  /// message.
+  bool DisplayFixesCount = true;
 };
 
 /// Contains basic information about a diagnostic.
 struct DiagBase {
   std::string Message;
   // Intended to be used only in error messages.
   // May be relative, absolute or even artifically constructed.
   std::string File;

clang-tools-extra/trunk/clangd/Diagnostics.cpp

 /// Example output:
 ///
 ///     no matching function for call to 'foo'
 ///
 ///     main.cpp:3:5: note: candidate function not viable: requires 2 arguments
 ///
 ///     dir1/dir2/dir3/../../dir4/header.h:12:23
 ///     note: candidate function not viable: requires 3 arguments
-std::string mainMessage(const Diag &D) {
+std::string mainMessage(const Diag &D, bool DisplayFixesCount) {
   std::string Result;
   llvm::raw_string_ostream OS(Result);
   OS << D.Message;
-  if (!D.Fixes.empty())
+  if (DisplayFixesCount && !D.Fixes.empty())
     OS << " (" << (D.Fixes.size() > 1 ? "fixes" : "fix") << " available)";
   for (auto &Note : D.Notes) {
     OS << "\n\n";
     printDiag(OS, Note);
   }
   OS.flush();
   return capitalize(std::move(Result));
 }
auto FillBasicFields = [](const DiagBase &D) -> clangd::Diagnostic {
     clangd::Diagnostic Res;
     Res.range = D.Range;
     Res.severity = getSeverity(D.Severity);
     return Res;
   };
 
   {
     clangd::Diagnostic Main = FillBasicFields(D);
-    Main.message = mainMessage(D);
+    Main.message = mainMessage(D, Opts.DisplayFixesCount);
     if (Opts.EmbedFixesInDiagnostics) {
       Main.codeActions.emplace();
       for (const auto &Fix : D.Fixes)
         Main.codeActions->push_back(toCodeAction(Fix, File));
     }
     if (Opts.SendDiagnosticCategory && !D.Category.empty())
       Main.category = D.Category;