From 15f8c71ec335920e0b083240407020343f907330 Mon Sep 17 00:00:00 2001
From: chrchr-github <78114321+chrchr-github@users.noreply.github.com>
Date: Sun, 24 Jul 2022 17:52:14 +0200
Subject: [PATCH] Fix #9946 FP: unassignedVariable when operator() is called
 subsequently (#4303)

---
 lib/checkunusedvar.cpp |  5 ++++-
 test/testunusedvar.cpp | 23 +++++++++++++++++++++++
 test/testvalueflow.cpp |  4 ++--
 3 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/lib/checkunusedvar.cpp b/lib/checkunusedvar.cpp
index 630ad66d8..e0f16d3cd 100644
--- a/lib/checkunusedvar.cpp
+++ b/lib/checkunusedvar.cpp
@@ -1078,7 +1078,10 @@ void CheckUnusedVar::checkFunctionVariableUsage_iterateScopes(const Scope* const
 
         // function
         else if (Token::Match(tok, "%name% (")) {
-            variables.read(tok->varId(), tok);
+            if (tok->varId() && !tok->function()) // operator()
+                variables.use(tok->varId(), tok);
+            else
+                variables.read(tok->varId(), tok);
             useFunctionArgs(tok->next()->astOperand2(), variables);
         } else if (Token::Match(tok, "std :: ref ( %var% )")) {
             variables.eraseAll(tok->tokAt(4)->varId());
diff --git a/test/testunusedvar.cpp b/test/testunusedvar.cpp
index eaaedfbd4..a97bc3980 100644
--- a/test/testunusedvar.cpp
+++ b/test/testunusedvar.cpp
@@ -136,6 +136,7 @@ private:
         TEST_CASE(localvar64); // #9997
         TEST_CASE(localvar65); // #9876, #10006
         TEST_CASE(localvar66); // #11143
+        TEST_CASE(localvar67); // #9946
         TEST_CASE(localvarloops); // loops
         TEST_CASE(localvaralias1);
         TEST_CASE(localvaralias2); // ticket #1637
@@ -3612,6 +3613,28 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
+    void localvar67() { // #9946
+        functionVariableUsage("struct B {\n"
+                              "    virtual ~B() {}\n"
+                              "    bool operator() () const { return true; }\n"
+                              "    virtual bool f() const = 0;\n"
+                              "};\n"
+                              "class D : B {\n"
+                              "public:\n"
+                              "    bool f() const override { return false; }\n"
+                              "};\n"
+                              "void f1() {\n"
+                              "    const D d1;\n"
+                              "    d1.f();\n"
+                              "}\n"
+                              "void f2() {\n"
+                              "    const D d2;\n"
+                              "    d2();\n"
+                              "        B() {}\n"
+                              "}\n");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void localvarloops() {
         // loops
         functionVariableUsage("void fun(int c) {\n"
diff --git a/test/testvalueflow.cpp b/test/testvalueflow.cpp
index 4bd7b27c5..f60a12b90 100644
--- a/test/testvalueflow.cpp
+++ b/test/testvalueflow.cpp
@@ -4520,8 +4520,8 @@ private:
         code = "struct base {\n"
                "    virtual int f() { return 0; }\n"
                "};\n"
-               "struct derived {\n"
-               "    virtual int f() { return 1; }\n"
+               "struct derived : base {\n"
+               "    int f() override { return 1; }\n"
                "};\n"
                "void g(derived* d) {\n"
                "    base* b = d;\n"