[clang-tools-extra] [clangd] Change completion-style default to detailed (PR #195963)

[via cfe-commits]

https://github.com/timon-ul updated https://github.com/llvm/llvm-project/pull/195963

>From d2588e760a7ce0da671add8c224c13a3c61b4fcf Mon Sep 17 00:00:00 2001
From: timon-ul <timon.ulrich at advantest.com>
Date: Wed, 6 May 2026 01:28:28 +0200
Subject: [PATCH 1/2] [clangd] Change completion-style default to detailed

Relevant discussion in https://github.com/clangd/clangd/discussions/2616#discussioncomment-16110659
---
 clang-tools-extra/clangd/ClangdLSPServer.cpp | 2 --
 clang-tools-extra/clangd/CodeComplete.cpp    | 2 +-
 clang-tools-extra/clangd/CodeComplete.h      | 5 +----
 3 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/clang-tools-extra/clangd/ClangdLSPServer.cpp b/clang-tools-extra/clangd/ClangdLSPServer.cpp
index 761b07eceec83..92ae7ccd2b685 100644
--- a/clang-tools-extra/clangd/ClangdLSPServer.cpp
+++ b/clang-tools-extra/clangd/ClangdLSPServer.cpp
@@ -518,8 +518,6 @@ void ClangdLSPServer::onInitialize(const InitializeParams &Params,
 
   Opts.CodeComplete.EnableSnippets = Params.capabilities.CompletionSnippets;
   Opts.CodeComplete.IncludeFixIts = Params.capabilities.CompletionFixes;
-  if (!Opts.CodeComplete.BundleOverloads)
-    Opts.CodeComplete.BundleOverloads = Params.capabilities.HasSignatureHelp;
   Opts.CodeComplete.DocumentationFormat =
       Params.capabilities.CompletionDocumentationFormat;
   Opts.SignatureHelpDocumentationFormat =
diff --git a/clang-tools-extra/clangd/CodeComplete.cpp b/clang-tools-extra/clangd/CodeComplete.cpp
index f43b5e71a1dfa..3a9631ad04b31 100644
--- a/clang-tools-extra/clangd/CodeComplete.cpp
+++ b/clang-tools-extra/clangd/CodeComplete.cpp
@@ -234,7 +234,7 @@ struct CompletionCandidate {
   size_t overloadSet(const CodeCompleteOptions &Opts, llvm::StringRef FileName,
                      IncludeInserter *Inserter,
                      CodeCompletionContext::Kind CCContextKind) const {
-    if (!Opts.BundleOverloads.value_or(false))
+    if (!Opts.BundleOverloads)
       return 0;
 
     // Depending on the index implementation, we can see different header
diff --git a/clang-tools-extra/clangd/CodeComplete.h b/clang-tools-extra/clangd/CodeComplete.h
index cde22a8212e6a..b466965cfff4e 100644
--- a/clang-tools-extra/clangd/CodeComplete.h
+++ b/clang-tools-extra/clangd/CodeComplete.h
@@ -59,10 +59,7 @@ struct CodeCompleteOptions {
   bool ForceLoadPreamble = false;
 
   /// Combine overloads into a single completion item where possible.
-  /// If none, the implementation may choose an appropriate behavior.
-  /// (In practice, ClangdLSPServer enables bundling if the client claims
-  /// to supports signature help).
-  std::optional<bool> BundleOverloads;
+  bool BundleOverloads = false;
 
   /// Limit the number of results returned (0 means no limit).
   /// If more results are available, we set CompletionList.isIncomplete.

>From 1f867af44c2da5e22681151360255e03841907c9 Mon Sep 17 00:00:00 2001
From: timon-ul <timon.ulrich at advantest.com>
Date: Wed, 6 May 2026 08:52:06 +0200
Subject: [PATCH 2/2] added release notes to notify the user of the new
 behaviour

---
 clang-tools-extra/docs/ReleaseNotes.rst | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index c7ec5ae66499b..ec63659708032 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -116,6 +116,14 @@ Code completion
   macros. ``ExactPrefix`` is the default, which retains previous
   behavior of suggesting macros which match the prefix exactly.
 
+- Changed completion-style default to ``detailed``. This means function
+  overloads will no longer be bundled together, but instead each have
+  their own completion item. This gives the user a better overview of the
+  possible overloads and also when accepting the item it will generate
+  placeholder parameters, which was not possible due to ambiguity with
+  ``bundled``. To change back to the old behaviour, pass the argument
+  ``--completion-style=bundled`` to clangd.
+
 Code actions
 ^^^^^^^^^^^^