Index: clangd/index/IndexAction.cpp
===================================================================
--- clangd/index/IndexAction.cpp
+++ clangd/index/IndexAction.cpp
@@ -135,6 +135,9 @@
   bool BeginInvocation(CompilerInstance &CI) override {
     // We want all comments, not just the doxygen ones.
     CI.getLangOpts().CommentOpts.ParseAllComments = true;
+    // Index the whole file even if there are warnings and -Werror is't set.
+    // Avoids some analyses too.
+    CI.getDiagnosticOpts().IgnoreWarnings = true;
     return WrapperFrontendAction::BeginInvocation(CI);
   }