[clangd] Expose the xref's incomplete flag to clangdServer API.

[hokein]

Summary

so that clangd C++ API users (via ClangdServer) can access it.

[merge_guards_bot]

Build result: fail - 60148 tests passed, 1 failed and 729 were skipped.

failed: LLVM.Bindings/Go/go.test

Log files: console-log.txt, CMakeCache.txt

[sammccall]

clang-tools-extra/clangd/XRefs.h

128

References -> ReferenceList or ReferencesResult, and Refs -> References?

calling the struct References seems unclear, and takes away the useful unabbreviated variable name

128

these comments don't seem to add much - remove?

129

we call this HasMore in code complete.

(incomplete is one word)

[sammccall]

Oops, LG apart from naming nits

[sammccall]

Let's see how many times I can miss the button

[hokein]

address naming comments.

clang-tools-extra/clangd/ClangdLSPServer.cpp

 // FIXME: This function needs to be properly tested.
 void ClangdLSPServer::onChangeConfiguration(
     const DidChangeConfigurationParams &Params) {
   applyConfiguration(Params.settings);
 }
 
 void ClangdLSPServer::onReference(const ReferenceParams &Params,
                                   Callback<std::vector<Location>> Reply) {
-  Server->findReferences(Params.textDocument.uri.file(), Params.position,
-                         CCOpts.Limit, std::move(Reply));
+  Server->findReferences(
+      Params.textDocument.uri.file(), Params.position, CCOpts.Limit,
+      [Reply = std::move(Reply)](llvm::Expected<References> Refs) mutable {
+        if (!Refs)
+          return Reply(Refs.takeError());
+        return Reply(std::move(Refs->Refs));
+      });
 }
 
 void ClangdLSPServer::onSymbolInfo(const TextDocumentPositionParams &Params,
                                    Callback<std::vector<SymbolDetails>> Reply) {
   Server->symbolInfo(Params.textDocument.uri.file(), Params.position,
                      std::move(Reply));
 }
 

clang-tools-extra/clangd/ClangdServer.h

void workspaceSymbols(StringRef Query, int Limit,
                         Callback<std::vector<SymbolInformation>> CB);
 
   /// Retrieve the symbols within the specified file.
   void documentSymbols(StringRef File,
                        Callback<std::vector<DocumentSymbol>> CB);
 
   /// Retrieve locations for symbol references.
   void findReferences(PathRef File, Position Pos, uint32_t Limit,
-                      Callback<std::vector<Location>> CB);
+                      Callback<References> CB);
 
   /// Run formatting for \p Rng inside \p File with content \p Code.
   llvm::Expected<tooling::Replacements> formatRange(StringRef Code,
                                                     PathRef File, Range Rng);
 
   /// Run formatting for the whole \p File with content \p Code.
   llvm::Expected<tooling::Replacements> formatFile(StringRef Code,
                                                    PathRef File);

clang-tools-extra/clangd/ClangdServer.cpp

auto Action =
         if (!InpAST)
           return CB(InpAST.takeError());
         CB(clangd::getDocumentSymbols(InpAST->AST));
       };
   WorkScheduler.runWithAST("documentSymbols", File, std::move(Action));
 }
 
 void ClangdServer::findReferences(PathRef File, Position Pos, uint32_t Limit,
-                                  Callback<std::vector<Location>> CB) {
+                                  Callback<References> CB) {
   auto Action = [Pos, Limit, CB = std::move(CB),
                  this](llvm::Expected<InputsAndAST> InpAST) mutable {
     if (!InpAST)
       return CB(InpAST.takeError());
     CB(clangd::findReferences(InpAST->AST, Pos, Limit, Index));
   };
 
   WorkScheduler.runWithAST("References", File, std::move(Action));

clang-tools-extra/clangd/XRefs.h

return std::tie(LHS.Type, LHS.Name, LHS.Default) ==
          std::tie(RHS.Type, RHS.Name, RHS.Default);
 }
 
 /// Get the hover information when hovering at \p Pos.
 llvm::Optional<HoverInfo> getHover(ParsedAST &AST, Position Pos,
                                    format::FormatStyle Style,
                                    const SymbolIndex *Index);
 
-/// Returns reference locations of the symbol at a specified \p Pos.
+struct References {
+  std::vector<Location> Refs; // reference locations of the symbol.
+  bool InComplete = false;    // true if the result is incomplete.
+};
+/// Returns references of the symbol at a specified \p Pos.
 /// \p Limit limits the number of results returned (0 means no limit).
-std::vector<Location> findReferences(ParsedAST &AST, Position Pos,
-                                     uint32_t Limit,
-                                     const SymbolIndex *Index = nullptr);
+References findReferences(ParsedAST &AST, Position Pos, uint32_t Limit,
 
 /// Get info about symbols at \p Pos.
 std::vector<SymbolDetails> getSymbolInfo(ParsedAST &AST, Position Pos);
 
 /// Find the record type references at \p Pos.
 const CXXRecordDecl *findRecordTypeAt(ParsedAST &AST, Position Pos);
 
 /// Given a record type declaration, find its base (parent) types.

clang-tools-extra/clangd/XRefs.cpp

if (auto Formatted =
     HI->Definition = *Formatted;
 
   HI->SymRange =
       getTokenRange(AST.getASTContext().getSourceManager(),
                     AST.getASTContext().getLangOpts(), SourceLocationBeg);
   return HI;
 }
 
-std::vector<Location> findReferences(ParsedAST &AST, Position Pos,
-                                     uint32_t Limit, const SymbolIndex *Index) {
+References findReferences(ParsedAST &AST, Position Pos, uint32_t Limit,
+                          const SymbolIndex *Index) {
   if (!Limit)
     Limit = std::numeric_limits<uint32_t>::max();
-  std::vector<Location> Results;
+  References Results;
+  // std::vector<Location> Results;
   const SourceManager &SM = AST.getSourceManager();
   auto MainFilePath =
       getCanonicalPath(SM.getFileEntryForID(SM.getMainFileID()), SM);
   if (!MainFilePath) {
     elog("Failed to get a path for the main file, so no references");
     return Results;
   }
   auto Loc = SM.getMacroArgExpandedLocation(
MainFileRefs.erase(std::unique(MainFileRefs.begin(), MainFileRefs.end(),
                      MainFileRefs.end());
   for (const auto &Ref : MainFileRefs) {
     if (auto Range =
             getTokenRange(AST.getASTContext().getSourceManager(),
                           AST.getASTContext().getLangOpts(), Ref.Loc)) {
       Location Result;
       Result.range = *Range;
       Result.uri = URIForFile::canonicalize(*MainFilePath, *MainFilePath);
-      Results.push_back(std::move(Result));
+      Results.Refs.push_back(std::move(Result));
     }
   }
-
   // Now query the index for references from other files.
-  if (Index && Results.size() < Limit) {
+  if (Index && Results.Refs.size() <= Limit) {
     RefsRequest Req;
     Req.Limit = Limit;
 
     for (const Decl *D : Decls) {
       // Not all symbols can be referenced from outside (e.g. function-locals).
       // TODO: we could skip TU-scoped symbols here (e.g. static functions) if
       // we know this file isn't a header. The details might be tricky.
       if (D->getParentFunctionOrMethod())
         continue;
       if (auto ID = getSymbolID(D))
         Req.IDs.insert(*ID);
     }
     if (Req.IDs.empty())
       return Results;
-    Index->refs(Req, [&](const Ref &R) {
+    Results.InComplete |= Index->refs(Req, [&](const Ref &R) {
+      // no need to continue process if we reach the limit.
+      if (Results.Refs.size() > Limit)
+        return;
       auto LSPLoc = toLSPLocation(R.Location, *MainFilePath);
       // Avoid indexed results for the main file - the AST is authoritative.
-      if (LSPLoc && LSPLoc->uri.file() != *MainFilePath)
-        Results.push_back(std::move(*LSPLoc));
+      if (!LSPLoc || LSPLoc->uri.file() == *MainFilePath)
+        return;
+
+      Results.Refs.push_back(std::move(*LSPLoc));
     });
   }
-  if (Results.size() > Limit)
-    Results.resize(Limit);
+  if (Results.Refs.size() > Limit) {
+    Results.InComplete = true;
+    Results.Refs.resize(Limit);
+  }
   return Results;
 }
 
 std::vector<SymbolDetails> getSymbolInfo(ParsedAST &AST, Position Pos) {
   const SourceManager &SM = AST.getSourceManager();
   auto Loc = SM.getMacroArgExpandedLocation(
       getBeginningOfIdentifier(Pos, SM, AST.getASTContext().getLangOpts()));
 

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

const char *Tests[] = {
       )cpp",
   };
   for (const char *Test : Tests) {
     Annotations T(Test);
     auto AST = TestTU::withCode(T.code()).build();
     std::vector<Matcher<Location>> ExpectedLocations;
     for (const auto &R : T.ranges())
       ExpectedLocations.push_back(RangeIs(R));
-    EXPECT_THAT(findReferences(AST, T.point(), 0),
+    EXPECT_THAT(findReferences(AST, T.point(), 0).Refs,
                 ElementsAreArray(ExpectedLocations))
         << Test;
   }
 }
 
 TEST(FindReferences, ExplicitSymbols) {
   const char *Tests[] = {
       R"cpp(
TEST(FindReferences, ExplicitSymbols) {
   };
   for (const char *Test : Tests) {
     Annotations T(Test);
     auto AST = TestTU::withCode(T.code()).build();
     std::vector<Matcher<Location>> ExpectedLocations;
     for (const auto &R : T.ranges())
       ExpectedLocations.push_back(RangeIs(R));
     ASSERT_THAT(ExpectedLocations, Not(IsEmpty()));
-    EXPECT_THAT(findReferences(AST, T.point(), 0),
+    EXPECT_THAT(findReferences(AST, T.point(), 0).Refs,
                 ElementsAreArray(ExpectedLocations))
         << Test;
   }
 }
 
 TEST(FindReferences, NeedsIndex) {
   const char *Header = "int foo();";
   Annotations Main("int main() { [[f^oo]](); }");
   TestTU TU;
   TU.Code = Main.code();
   TU.HeaderCode = Header;
   auto AST = TU.build();
 
   // References in main file are returned without index.
-  EXPECT_THAT(findReferences(AST, Main.point(), 0, /*Index=*/nullptr),
+  EXPECT_THAT(findReferences(AST, Main.point(), 0, /*Index=*/nullptr).Refs,
               ElementsAre(RangeIs(Main.range())));
   Annotations IndexedMain(R"cpp(
     int main() { [[f^oo]](); }
   )cpp");
 
   // References from indexed files are included.
   TestTU IndexedTU;
   IndexedTU.Code = IndexedMain.code();
   IndexedTU.Filename = "Indexed.cpp";
   IndexedTU.HeaderCode = Header;
-  EXPECT_THAT(findReferences(AST, Main.point(), 0, IndexedTU.index().get()),
-              ElementsAre(RangeIs(Main.range()), RangeIs(IndexedMain.range())));
-
-  EXPECT_EQ(1u, findReferences(AST, Main.point(), /*Limit*/ 1,
-                               IndexedTU.index().get())
-                    .size());
+  EXPECT_THAT(
+      findReferences(AST, Main.point(), 0, IndexedTU.index().get()).Refs,
+  auto LimitRefs =
+      findReferences(AST, Main.point(), /*Limit*/ 1, IndexedTU.index().get());
+  EXPECT_EQ(1u, LimitRefs.Refs.size());
+  EXPECT_TRUE(LimitRefs.InComplete);
 
   // If the main file is in the index, we don't return duplicates.
   // (even if the references are in a different location)
   TU.Code = ("\n\n" + Main.code()).str();
-  EXPECT_THAT(findReferences(AST, Main.point(), 0, TU.index().get()),
+  EXPECT_THAT(findReferences(AST, Main.point(), 0, TU.index().get()).Refs,
               ElementsAre(RangeIs(Main.range())));
 }
 
 TEST(FindReferences, NoQueryForLocalSymbols) {
   struct RecordingIndex : public MemIndex {
     mutable Optional<llvm::DenseSet<SymbolID>> RefIDs;
     bool refs(const RefsRequest &Req,
               llvm::function_ref<void(const Ref &)>) const override {