[clangd] Add support for type hierarchy (super types only for now)

Summary:
Patch by Nathan Ridge(@nridge)!

This is an LSP extension proposed here:
https://github.com/Microsoft/vscode-languageserver-node/pull/426

An example client implementation can be found here:
https://github.com/theia-ide/theia/pull/3802

Reviewers: kadircet, sammccall

Reviewed By: kadircet

Subscribers: jdoerfert, sammccall, cfe-commits, mgorny, dschaefer, simark, ilya-biryukov, ioeric, MaskRay, jkorous, arphaman, kadircet

Tags: #clang

Differential Revision: https://reviews.llvm.org/D56370

llvm-svn: 356445

1 files changed, 15 insertions, 3 deletions

diff --git a/clang-tools-extra/clangd/ClangdServer.cpp b/clang-tools-extra/clangd/ClangdServer.cpp
index 9dc332806de..a265f3722ec 100644
--- a/clang-tools-extra/clangd/ClangdServer.cpp
+++ b/clang-tools-extra/clangd/ClangdServer.cpp
@@ -362,9 +362,8 @@ void ClangdServer::enumerateTweaks(PathRef File, Range Sel,
 
 void ClangdServer::applyTweak(PathRef File, Range Sel, StringRef TweakID,
                               Callback<tooling::Replacements> CB) {
-  auto Action = [Sel](decltype(CB) CB, std::string File,
-                            std::string TweakID,
-                            Expected<InputsAndAST> InpAST) {
+  auto Action = [Sel](decltype(CB) CB, std::string File, std::string TweakID,
+                      Expected<InputsAndAST> InpAST) {
     if (!InpAST)
       return CB(InpAST.takeError());
     auto Selection = tweakSelection(Sel, *InpAST);
@@ -523,6 +522,19 @@ void ClangdServer::findHover(PathRef File, Position Pos,
   WorkScheduler.runWithAST("Hover", File, Bind(Action, std::move(CB)));
 }
 
+void ClangdServer::typeHierarchy(PathRef File, Position Pos, int Resolve,
+                                 TypeHierarchyDirection Direction,
+                                 Callback<Optional<TypeHierarchyItem>> CB) {
+  auto Action = [Pos, Resolve, Direction](decltype(CB) CB,
+                                          Expected<InputsAndAST> InpAST) {
+    if (!InpAST)
+      return CB(InpAST.takeError());
+    CB(clangd::getTypeHierarchy(InpAST->AST, Pos, Resolve, Direction));
+  };
+
+  WorkScheduler.runWithAST("Type Hierarchy", File, Bind(Action, std::move(CB)));
+}
+
 tooling::CompileCommand ClangdServer::getCompileCommand(PathRef File) {
   trace::Span Span("GetCompileCommand");
   llvm::Optional<tooling::CompileCommand> C = CDB.getCompileCommand(File);