From eb7b004313efc7f6d08444b9762ad8cd3db145fc Mon Sep 17 00:00:00 2001
From: Leander Schulten <Leander.Schulten@rwth-aachen.de>
Date: Tue, 10 Nov 2026 16:17:11 +0100
Subject: [PATCH] Fix #15197 FP uninitMemberVarNoCtor for class without
 constructor that has a member of a type without default constructor

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 lib/checkclass.cpp        | 13 +++++++++-
 test/testconstructors.cpp | 54 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 66 insertions(+), 1 deletion(-)

diff --git a/lib/checkclass.cpp b/lib/checkclass.cpp
index a6fb1aecac4..1bc1ea1fcd9 100644
--- a/lib/checkclass.cpp
+++ b/lib/checkclass.cpp
@@ -104,6 +104,16 @@ static bool isVclTypeInit(const Type *type)
         return false;
     });
 }
+
+// Returns true if the class has constructors but none of them can be called without arguments
+static bool hasNoDefaultConstructor(const Scope& scope)
+{
+    return scope.numConstructors > 0 && std::none_of(scope.functionList.cbegin(), scope.functionList.cend(), [](const Function& func) {
+        // a variadic constructor can be called without arguments if only the parameter pack or ellipsis is left
+        const size_t requiredArgs = func.isVariadic() ? 1 : 0;
+        return func.isConstructor() && func.minArgCount() == requiredArgs && !func.isDelete();
+    });
+}
 //---------------------------------------------------------------------------
 
 CheckClassImpl::CheckClassImpl(const Tokenizer *tokenizer, const Settings &settings, ErrorLogger &errorLogger)
@@ -447,7 +457,8 @@ void CheckClassImpl::constructors()
                 if (var.hasDefault()) {
                     usage.init = true;
                     hasAnyDefaultInit = true;
-                } else if (!var.isStatic() && (var.isReference() || (var.isConst() && !var.isClass()))) {
+                } else if (!var.isStatic() && (var.isReference() || (var.isConst() && !var.isClass()) ||
+                                               (!var.isPointer() && !var.isPointerArray() && var.typeScope() && hasNoDefaultConstructor(*var.typeScope())))) {
                     // the default constructor is deleted, so all members are initialized by every instance
                     isDefaultConstructible = false;
                 } else if (cpp14OrLater && !hasAnySelfInit && checkInitialization(usage, FunctionType::eConstructor) == Initialization::Initialized) {
diff --git a/test/testconstructors.cpp b/test/testconstructors.cpp
index 47a5512fc79..1cd9270d344 100644
--- a/test/testconstructors.cpp
+++ b/test/testconstructors.cpp
@@ -940,6 +940,60 @@ class TestConstructors : public TestFixture {
         ASSERT_EQUALS("[test.cpp:3:9]: (warning) Member variable 'S::x' has no initializer. [uninitMemberVarNoCtor]\n"
                       "[test.cpp:7:9]: (warning) Member variable 'T::x' has no initializer. [uninitMemberVarNoCtor]\n",
                       errout_str());
+
+        check("struct N {\n" // #15197
+              "    explicit N(int);\n"
+              "};\n"
+              "struct D {\n"
+              "    D() = delete;\n"
+              "};\n"
+              "struct S {\n"
+              "    N n;\n"
+              "    int i;\n"
+              "    bool b = true;\n"
+              "};\n"
+              "struct W {\n"
+              "    W(int, ...);\n"
+              "};\n"
+              "struct T {\n"
+              "    D d;\n"
+              "    int i;\n"
+              "    bool b = true;\n"
+              "};\n"
+              "struct U {\n"
+              "    W w;\n"
+              "    int i;\n"
+              "    bool b = true;\n"
+              "};\n"
+              "struct A {\n"
+              "    N a[2];\n"
+              "    int i;\n"
+              "    bool b = true;\n"
+              "};\n");
+        ASSERT_EQUALS("", errout_str());
+
+        check("struct N {\n"
+              "    explicit N(int = 0);\n"
+              "};\n"
+              "struct V {\n"
+              "    template<class... A> explicit V(A&&... a);\n"
+              "};\n"
+              "struct C {\n"
+              "    C(...);\n"
+              "};\n"
+              "struct M {\n"
+              "    explicit M(int);\n"
+              "};\n"
+              "struct S {\n"
+              "    N n;\n"
+              "    V v;\n"
+              "    C c;\n"
+              "    M* p;\n"
+              "    M* q[2];\n"
+              "    int i;\n"
+              "    bool b = true;\n"
+              "};\n");
+        ASSERT_EQUALS("[test.cpp:19:9]: (warning) Member variable 'S::i' has no initializer. [uninitMemberVarNoCtor]\n", errout_str());
     }
 
     // ticket #4290 "False Positive: style (noConstructor): The class 'foo' does not have a constructor."