[clangd] Build dynamic index and use it for code completion.

Reviewers: sammccall

Reviewed By: sammccall

Subscribers: klimek, ilya-biryukov, cfe-commits

Differential Revision: https://reviews.llvm.org/D41289

llvm-svn: 321092

1 files changed, 13 insertions, 0 deletions

diff --git a/clang-tools-extra/clangd/ClangdServer.cpp b/clang-tools-extra/clangd/ClangdServer.cpp
index 129fc074e44..e7c9c7a5148 100644
--- a/clang-tools-extra/clangd/ClangdServer.cpp
+++ b/clang-tools-extra/clangd/ClangdServer.cpp
@@ -134,8 +134,19 @@ ClangdServer::ClangdServer(GlobalCompilationDatabase &CDB,
                            FileSystemProvider &FSProvider,
                            unsigned AsyncThreadsCount,
                            bool StorePreamblesInMemory,
+                           bool BuildDynamicSymbolIndex,
                            llvm::Optional<StringRef> ResourceDir)
     : CDB(CDB), DiagConsumer(DiagConsumer), FSProvider(FSProvider),
+      FileIdx(BuildDynamicSymbolIndex ? new FileIndex() : nullptr),
+      // Pass a callback into `Units` to extract symbols from a newly parsed
+      // file and rebuild the file index synchronously each time an AST is
+      // parsed.
+      // FIXME(ioeric): this can be slow and we may be able to index on less
+      // critical paths.
+      Units(FileIdx
+                ? [this](const Context &Ctx, PathRef Path,
+                         ParsedAST *AST) { FileIdx->update(Ctx, Path, AST); }
+                : ASTParsedCallback()),
       ResourceDir(ResourceDir ? ResourceDir->str() : getStandardResourceDir()),
       PCHs(std::make_shared<PCHContainerOperations>()),
       StorePreamblesInMemory(StorePreamblesInMemory),
@@ -238,6 +249,8 @@ void ClangdServer::codeComplete(
       Resources->getPossiblyStalePreamble();
   // Copy completion options for passing them to async task handler.
   auto CodeCompleteOpts = Opts;
+  if (FileIdx)
+    CodeCompleteOpts.Index = FileIdx.get();
   // A task that will be run asynchronously.
   auto Task =
       // 'mutable' to reassign Preamble variable.