From c26752b56f1370f1fdbf1cd1dc15bc7cde754a65 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?=
 <daniel.marjamaki@cppchecksolutions.com>
Date: Mon, 27 Oct 2025 15:22:24 +0100
Subject: [PATCH 1/2] Fixed #14129 (false positive: unusedPrivateFunction with
 __attribute__((unused)))

---
 lib/checkclass.cpp          | 2 +-
 test/testunusedprivfunc.cpp | 8 ++++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/lib/checkclass.cpp b/lib/checkclass.cpp
index e0721531299..cf706d35069 100644
--- a/lib/checkclass.cpp
+++ b/lib/checkclass.cpp
@@ -1342,7 +1342,7 @@ void CheckClass::privateFunctions()
 
         while (!privateFuncs.empty()) {
             const auto& pf = privateFuncs.front();
-            if (pf->token->isAttributeMaybeUnused()) {
+            if (pf->token->isAttributeMaybeUnused() || pf->token->isAttributeUnused()) {
                 privateFuncs.pop_front();
                 continue;
             }
diff --git a/test/testunusedprivfunc.cpp b/test/testunusedprivfunc.cpp
index 537385d60aa..6b5462aa867 100644
--- a/test/testunusedprivfunc.cpp
+++ b/test/testunusedprivfunc.cpp
@@ -84,6 +84,7 @@ class TestUnusedPrivateFunction : public TestFixture {
 
         TEST_CASE(templateSimplification); //ticket #6183
         TEST_CASE(maybeUnused);
+        TEST_CASE(attributeUnused); // #14129
         TEST_CASE(trailingReturn);
     }
 
@@ -890,6 +891,13 @@ class TestUnusedPrivateFunction : public TestFixture {
         ASSERT_EQUALS("", errout_str());
     }
 
+    void attributeUnused() {
+        check("class C {\n"
+              "    __attribute__((unused)) int f() { return 42; }\n"
+              "};");
+        ASSERT_EQUALS("", errout_str());
+    }
+
     void trailingReturn() {
         check("struct B { virtual void f(); };\n"
               "struct D : B {\n"

From 2b1df39dcdefca0af6c2104b9a83096cbe525b9c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?=
 <daniel.marjamaki@cppchecksolutions.com>
Date: Mon, 27 Oct 2025 18:36:01 +0100
Subject: [PATCH 2/2] out of line definition

---
 lib/checkclass.cpp          | 2 +-
 test/testunusedprivfunc.cpp | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/checkclass.cpp b/lib/checkclass.cpp
index cf706d35069..53cff41d92c 100644
--- a/lib/checkclass.cpp
+++ b/lib/checkclass.cpp
@@ -1346,7 +1346,7 @@ void CheckClass::privateFunctions()
                 privateFuncs.pop_front();
                 continue;
             }
-            if (pf->tokenDef && pf->tokenDef->isAttributeMaybeUnused()) {
+            if (pf->tokenDef && (pf->tokenDef->isAttributeMaybeUnused() || pf->tokenDef->isAttributeUnused())) {
                 privateFuncs.pop_front();
                 continue;
             }
diff --git a/test/testunusedprivfunc.cpp b/test/testunusedprivfunc.cpp
index 6b5462aa867..5a364347163 100644
--- a/test/testunusedprivfunc.cpp
+++ b/test/testunusedprivfunc.cpp
@@ -896,6 +896,12 @@ class TestUnusedPrivateFunction : public TestFixture {
               "    __attribute__((unused)) int f() { return 42; }\n"
               "};");
         ASSERT_EQUALS("", errout_str());
+
+        check("class C {\n"
+              "    __attribute__((unused)) int f();\n"
+              "};\n"
+              "int C::f() { return 42; }\n");
+        ASSERT_EQUALS("", errout_str());
     }
 
     void trailingReturn() {