[clangd] Show function documentation in signature help

Summary:
Previously, clangd was trying to show documentation for the active
parameter instead, which is wrong per LSP specification.

Moreover, the code path that attempts to get parameter comments never
succeds, because no attempt is made to parse function doc comment and
extract parameter-specific parts out of it. So we also remove the code
that claims to fetch parameter comments: it is not used anymore and is
incorrect.

Reviewers: hokein, ioeric, kadircet

Reviewed By: ioeric

Subscribers: MaskRay, jkorous, arphaman, cfe-commits

Differential Revision: https://reviews.llvm.org/D50726

llvm-svn: 340004

1 files changed, 8 insertions, 26 deletions

diff --git a/clang-tools-extra/clangd/CodeCompletionStrings.cpp b/clang-tools-extra/clangd/CodeCompletionStrings.cpp
index e0277000c67..21db26e0808 100644
--- a/clang-tools-extra/clangd/CodeCompletionStrings.cpp
+++ b/clang-tools-extra/clangd/CodeCompletionStrings.cpp
@@ -51,44 +51,26 @@ std::string getDocComment(const ASTContext &Ctx,
   // get this declaration, so we don't show documentation in that case.
   if (Result.Kind != CodeCompletionResult::RK_Declaration)
     return "";
-  auto *Decl = Result.getDeclaration();
-  if (!Decl || llvm::isa<NamespaceDecl>(Decl)) {
+  return Result.getDeclaration() ? getDeclComment(Ctx, *Result.getDeclaration())
+                                 : "";
+}
+
+std::string getDeclComment(const ASTContext &Ctx, const NamedDecl &Decl) {
+  if (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 "";
   }
-  const RawComment *RC = getCompletionComment(Ctx, Decl);
-  if (!RC)
-    return "";
-
-  // Sanity check that the comment does not come from the PCH. We choose to not
-  // write them into PCH, because they are racy and slow to load.
-  assert(!Ctx.getSourceManager().isLoadedSourceLocation(RC->getBeginLoc()));
-  std::string Doc = RC->getFormattedText(Ctx.getSourceManager(), Ctx.getDiagnostics());
-  if (!looksLikeDocComment(Doc))
-    return "";
-  return Doc;
-}
-
-std::string
-getParameterDocComment(const ASTContext &Ctx,
-                       const CodeCompleteConsumer::OverloadCandidate &Result,
-                       unsigned ArgIndex, bool CommentsFromHeaders) {
-  auto *Func = Result.getFunction();
-  if (!Func)
-    return "";
-  const RawComment *RC = getParameterComment(Ctx, Result, ArgIndex);
+  const RawComment *RC = getCompletionComment(Ctx, &Decl);
   if (!RC)
     return "";
   // Sanity check that the comment does not come from the PCH. We choose to not
   // write them into PCH, because they are racy and slow to load.
   assert(!Ctx.getSourceManager().isLoadedSourceLocation(RC->getBeginLoc()));
   std::string Doc = RC->getFormattedText(Ctx.getSourceManager(), Ctx.getDiagnostics());
-  if (!looksLikeDocComment(Doc))
-    return "";
-  return Doc;
+  return looksLikeDocComment(Doc) ? Doc : "";
 }
 
 void getSignature(const CodeCompletionString &CCS, std::string *Signature,