From 568eae48a4e19c0359cdcd2a33b8ec9812e4abbc Mon Sep 17 00:00:00 2001
From: Daniel Jasper <djasper@google.com>
Date: Wed, 13 Jun 2012 18:31:09 +0000
Subject: [PATCH] Allow __attribute__((unused)) for fields and make it silence
 -Wunused-private-field.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@158411 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Sema/SemaDeclAttr.cpp           | 2 +-
 lib/Sema/SemaDeclCXX.cpp            | 1 +
 test/SemaCXX/warn-unused-member.cpp | 2 ++
 3 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp
index 19ac6160c5..cf17af0341 100644
--- a/lib/Sema/SemaDeclAttr.cpp
+++ b/lib/Sema/SemaDeclAttr.cpp
@@ -1610,7 +1610,7 @@ static void handleUnusedAttr(Sema &S, Decl *D, const AttributeList &Attr) {
   }
 
   if (!isa<VarDecl>(D) && !isa<ObjCIvarDecl>(D) && !isFunctionOrMethod(D) &&
-      !isa<TypeDecl>(D) && !isa<LabelDecl>(D)) {
+      !isa<TypeDecl>(D) && !isa<LabelDecl>(D) && !isa<FieldDecl>(D)) {
     S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
       << Attr.getName() << ExpectedVariableFunctionOrLabel;
     return;
diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index 4bd1c3202c..12a63b189b 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -1646,6 +1646,7 @@ Sema::ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS, Declarator &D,
       // effects and are not part of a dependent type declaration.
       if (!FD->isImplicit() && FD->getDeclName() &&
           FD->getAccess() == AS_private &&
+          !FD->hasAttr<UnusedAttr>() &&
           !FD->getParent()->getTypeForDecl()->isDependentType() &&
           !InitializationHasSideEffects(*FD))
         UnusedPrivateFields.insert(FD);
diff --git a/test/SemaCXX/warn-unused-member.cpp b/test/SemaCXX/warn-unused-member.cpp
index 16e1e22ee8..00de8a97ac 100644
--- a/test/SemaCXX/warn-unused-member.cpp
+++ b/test/SemaCXX/warn-unused-member.cpp
@@ -115,6 +115,8 @@ class A {
   Trivial user_constructor_;
   NonTrivialConstructor non_trivial_constructor_;
   NonTrivialDestructor non_trivial_destructor_;
+
+  int attr_  __attribute__((unused));
 };
 
 class EverythingUsed {
-- 
2.40.0