[clangd] Record metrics for code action and rename usage

[kadircet]

Summary

Depends on D78429.

[kadircet]

Merged into D78429

clang-tools-extra/clangd/ClangdServer.cpp

 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/ScopeExit.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/Errc.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
+#include "llvm/Support/ScopedPrinter.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 #include <future>
 #include <memory>
 #include <mutex>
 #include <type_traits>
 
 namespace clang {
if (Opts.WantFormat) {
       llvm::Error Err = llvm::Error::success();
       for (auto &E : *Edits)
         Err =
             llvm::joinErrors(reformatEdit(E.getValue(), Style), std::move(Err));
 
       if (Err)
         return CB(std::move(Err));
     }
+    trace::Metric M("/clangd/rename");
+    M.T = trace::Metric::Sample;
+    M.Value = Edits->size();
+    trace::record(M);
     return CB(std::move(*Edits));
   };
   WorkScheduler.runWithAST("Rename", File, std::move(Action));
 }
 
 // May generate several candidate selections, due to SelectionTree ambiguity.
 // vector of pointers because GCC doesn't like non-copyable Selection.
 static llvm::Expected<std::vector<std::unique_ptr<Tweak::Selection>>>
auto Action = [File = File.str(), Sel, CB = std::move(CB),
     if (!Selections)
       return CB(Selections.takeError());
     std::vector<TweakRef> Res;
     // Don't allow a tweak to fire more than once across ambiguous selections.
     llvm::DenseSet<llvm::StringRef> PreparedTweaks;
     auto Filter = [&](const Tweak &T) {
       return TweakFilter(T) && !PreparedTweaks.count(T.id());
     };
+    trace::Metric M("/clangd/shown_codeaction");
+    M.T = trace::Metric::Increment;
+    M.Value = 1;
     for (const auto &Sel : *Selections) {
       for (auto &T : prepareTweaks(*Sel, Filter)) {
         Res.push_back({T->id(), T->title(), T->intent()});
         PreparedTweaks.insert(T->id());
+        M.Labels = {T->id()};
+        trace::record(M);
       }
     }
 
     CB(std::move(Res));
   };
 
   WorkScheduler.runWithAST("EnumerateTweaks", File, std::move(Action),
                            TUScheduler::InvalidateOnUpdate);
 }
 
 void ClangdServer::applyTweak(PathRef File, Range Sel, StringRef TweakID,
                               Callback<Tweak::Effect> CB) {
   auto Action =
       [File = File.str(), Sel, TweakID = TweakID.str(), CB = std::move(CB),
        FS = FSProvider.getFileSystem()](Expected<InputsAndAST> InpAST) mutable {
         if (!InpAST)
           return CB(InpAST.takeError());
         auto Selections = tweakSelection(Sel, *InpAST);
         if (!Selections)
           return CB(Selections.takeError());
+        trace::Metric M("/clangd/executed_tweaks");
+        M.T = trace::Metric::Increment;
+        M.Value = 1;
+        M.Labels = {TweakID, /*Error=*/""};
+        auto _ = llvm::make_scope_exit([&M] { trace::record(M); });
         llvm::Optional<llvm::Expected<Tweak::Effect>> Effect;
         // Try each selection, take the first one that prepare()s.
         // If they all fail, Effect will hold get the last error.
         for (const auto &Selection : *Selections) {
           auto T = prepareTweak(TweakID, *Selection);
           if (T) {
             Effect = (*T)->apply(*Selection);
             break;
           }
           Effect = T.takeError();
         }
         assert(Effect.hasValue() && "Expected at least one selection");
         if (*Effect) {
           // Tweaks don't apply clang-format, do that centrally here.
           for (auto &It : (*Effect)->ApplyEdits) {
             Edit &E = It.second;
             format::FormatStyle Style =
                 getFormatStyleForFile(File, E.InitialCode, FS.get());
             if (llvm::Error Err = reformatEdit(E, Style))
               elog("Failed to format {0}: {1}", It.first(), std::move(Err));
           }
-        }
           return CB(std::move(*Effect));
+        }
+        auto Err = Effect->takeError();
+        M.Labels.back() = llvm::to_string(Err);
+        return CB(std::move(Err));
       };
   WorkScheduler.runWithAST("ApplyTweak", File, std::move(Action));
 }
 
 void ClangdServer::dumpAST(PathRef File,
                            llvm::unique_function<void(std::string)> Callback) {
   auto Action = [Callback = std::move(Callback)](
                     llvm::Expected<InputsAndAST> InpAST) mutable {