Fix #14160 FP unreadVariable for smart pointer (danmar#8452)

Co-authored-by: chrchr-github <noreply@github.com>

Author: chrchr-github

lib/checkunusedvar.cpp

@@ -1359,13 +1359,19 @@ void CheckUnusedVar::checkFunctionVariableUsage()
             if (tok->previous() && tok->previous()->variable() && tok->previous()->variable()->nameToken()->scope()->type == ScopeType::eUnion)
                 continue;
 
-            if (expr->valueType() &&
-                expr->valueType()->type == ValueType::RECORD &&
-                !expr->valueType()->pointer &&
-                expr->valueType()->typeScope &&
-                expr->valueType()->typeScope->definedType &&
-                !symbolDatabase->isRecordTypeWithoutSideEffects(expr->valueType()->typeScope->definedType))
-                continue;
+            if (const ValueType *vt = expr->valueType()) {
+                if (vt->type == ValueType::RECORD &&
+                    !vt->pointer &&
+                    vt->typeScope &&
+                    vt->typeScope->definedType &&
+                    !symbolDatabase->isRecordTypeWithoutSideEffects(vt->typeScope->definedType))
+                    continue;
+
+                if (vt->type == ValueType::SMART_POINTER &&
+                    vt->smartPointerType &&
+                    !symbolDatabase->isRecordTypeWithoutSideEffects(vt->smartPointerType))
+                    continue;
+            }
 
             FwdAnalysis fwdAnalysis(*mSettings);
             const Token* scopeEnd = ValueFlow::getEndOfExprScope(expr, scope, /*smallest*/ false);

test/testunusedvar.cpp

@@ -6767,6 +6767,13 @@ class TestUnusedVar : public TestFixture {
                               "    p = nullptr;\n"
                               "}\n");
         ASSERT_EQUALS("", errout_str());
+
+        functionVariableUsage("struct S { S(); };\n" // #14160
+                              "void f() {\n"
+                              "    auto p = std::make_unique<S>();\n"
+                              "    auto q = std::make_unique<U>();\n"
+                              "}\n");
+        ASSERT_EQUALS("", errout_str());
     }
 
     // ticket #3104 - false positive when variable is read with "if (NOT var)"