[clang-tools-extra] [clang-tidy] Avoid diagnosing std::array initializations for modernize-use-designated-initializers (PR #134774)

[David Rivera via cfe-commits]

https://github.com/RiverDave updated https://github.com/llvm/llvm-project/pull/134774

>From bf1294a2be9da63717087f8940a7bad5b3c522f6 Mon Sep 17 00:00:00 2001
From: David Rivera <davidriverg at gmail.com>
Date: Mon, 7 Apr 2025 23:21:50 -0400
Subject: [PATCH 1/2] [clang-tidy] Avoid diagnosing std::array initializations
 for modernize-use-designated-initializers

---
 .../modernize/UseDesignatedInitializersCheck.cpp           | 7 ++++++-
 clang-tools-extra/docs/ReleaseNotes.rst                    | 4 ++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/clang-tools-extra/clang-tidy/modernize/UseDesignatedInitializersCheck.cpp b/clang-tools-extra/clang-tidy/modernize/UseDesignatedInitializersCheck.cpp
index 3132067f3d5ec..9e2ac149d0868 100644
--- a/clang-tools-extra/clang-tidy/modernize/UseDesignatedInitializersCheck.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/UseDesignatedInitializersCheck.cpp
@@ -119,13 +119,18 @@ UseDesignatedInitializersCheck::UseDesignatedInitializersCheck(
 void UseDesignatedInitializersCheck::registerMatchers(MatchFinder *Finder) {
   const auto HasBaseWithFields =
       hasAnyBase(hasType(cxxRecordDecl(has(fieldDecl()))));
+
+  // see #133715
+  const auto IsSTLArray =
+      hasType(qualType(hasDeclaration(recordDecl(hasName("::std::array")))));
+
   Finder->addMatcher(
       initListExpr(
           hasType(cxxRecordDecl(RestrictToPODTypes ? isPOD() : isAggregate(),
                                 unless(HasBaseWithFields))
                       .bind("type")),
           IgnoreSingleElementAggregates ? hasMoreThanOneElement() : anything(),
-          unless(isFullyDesignated()))
+          unless(anyOf(isFullyDesignated(), IsSTLArray)))
           .bind("init"),
       this);
 }
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 6c1f05009df98..44c348f453543 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -171,6 +171,10 @@ Changes in existing checks
   ``constexpr`` and ``static``` values on member initialization and by detecting
   explicit casting of built-in types within member list initialization.
 
+- Improved :doc:`modernize-use-designated-initializers
+  <clang-tidy/checks/modernize/use-designated-initializers>` check by avoiding
+  diagnosing designated initializers for ``std::array`` initializations.
+
 - Improved :doc:`modernize-use-ranges
   <clang-tidy/checks/modernize/use-ranges>` check by updating suppress 
   warnings logic for ``nullptr`` in ``std::find``.

>From 9727ea1d3990f6612231cbd087532bc5a021c2d9 Mon Sep 17 00:00:00 2001
From: David Rivera <davidriverg at gmail.com>
Date: Sat, 12 Apr 2025 19:55:39 -0400
Subject: [PATCH 2/2] [clang-tidy] avoid diagnosing std::array initializations
 for modernize-use-designated-initializers when IgnoreSingleElementAggregates
 is false

---
 .../modernize/UseDesignatedInitializersCheck.cpp      | 11 +++++------
 clang-tools-extra/docs/ReleaseNotes.rst               |  3 ++-
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/clang-tools-extra/clang-tidy/modernize/UseDesignatedInitializersCheck.cpp b/clang-tools-extra/clang-tidy/modernize/UseDesignatedInitializersCheck.cpp
index 9e2ac149d0868..296887119c310 100644
--- a/clang-tools-extra/clang-tidy/modernize/UseDesignatedInitializersCheck.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/UseDesignatedInitializersCheck.cpp
@@ -120,17 +120,16 @@ void UseDesignatedInitializersCheck::registerMatchers(MatchFinder *Finder) {
   const auto HasBaseWithFields =
       hasAnyBase(hasType(cxxRecordDecl(has(fieldDecl()))));
 
-  // see #133715
-  const auto IsSTLArray =
-      hasType(qualType(hasDeclaration(recordDecl(hasName("::std::array")))));
-
   Finder->addMatcher(
       initListExpr(
           hasType(cxxRecordDecl(RestrictToPODTypes ? isPOD() : isAggregate(),
-                                unless(HasBaseWithFields))
+                                unless(anyOf(HasBaseWithFields,
+                                             IgnoreSingleElementAggregates
+                                                 ? hasName("::std::array")
+                                                 : anything())))
                       .bind("type")),
           IgnoreSingleElementAggregates ? hasMoreThanOneElement() : anything(),
-          unless(anyOf(isFullyDesignated(), IsSTLArray)))
+          unless(isFullyDesignated()))
           .bind("init"),
       this);
 }
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 44c348f453543..f6f1d27c1cff7 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -173,7 +173,8 @@ Changes in existing checks
 
 - Improved :doc:`modernize-use-designated-initializers
   <clang-tidy/checks/modernize/use-designated-initializers>` check by avoiding
-  diagnosing designated initializers for ``std::array`` initializations.
+  diagnosing designated initializers for ``std::array`` initializations when
+  `IgnoreSingleElementAggregates` is false.
 
 - Improved :doc:`modernize-use-ranges
   <clang-tidy/checks/modernize/use-ranges>` check by updating suppress