[clangd] Do not show namespace comments.

Summary:
Comments from namespaces that clangd produces are too noisy and often
not useful.

Namespaces have too many redecls and we don't have a good way of
determining which of the comments are relevant and which should be
ignored (e.g. because they come from code generators like the protobuf
compiler).

Reviewers: sammccall

Reviewed By: sammccall

Subscribers: ioeric, MaskRay, jkorous, cfe-commits

Differential Revision: https://reviews.llvm.org/D48211

llvm-svn: 335718

1 files changed, 9 insertions, 1 deletions

diff --git a/clang-tools-extra/clangd/CodeCompletionStrings.cpp b/clang-tools-extra/clangd/CodeCompletionStrings.cpp
index 504ab6c95bf..6bad0eacd3b 100644
--- a/clang-tools-extra/clangd/CodeCompletionStrings.cpp
+++ b/clang-tools-extra/clangd/CodeCompletionStrings.cpp
@@ -80,8 +80,16 @@ std::string getDocComment(const ASTContext &Ctx,
   if (Result.Kind != CodeCompletionResult::RK_Declaration)
     return "";
   auto *Decl = Result.getDeclaration();
-  if (!Decl || !canRequestComment(Ctx, *Decl, CommentsFromHeaders))
+  if (!Decl || llvm::isa<NamespaceDecl>(Decl)) {
+    // Namespaces often have too many redecls for any particular redecl comment
+    // to be useful. Moreover, we often confuse file headers or generated
+    // comments with namespace comments. Therefore we choose to just ignore
+    // the comments for namespaces.
     return "";
+  }
+  if (!canRequestComment(Ctx, *Decl, CommentsFromHeaders))
+    return "";
+
   const RawComment *RC = getCompletionComment(Ctx, Decl);
   if (!RC)
     return "";