Support function pointers in CheckUnusedVar::checkFunctionVariableUsage_iterateScopes() (#7194)

Author: PKEuS

lib/checkunusedvar.cpp

@@ -704,6 +704,8 @@ void CheckUnusedVar::checkFunctionVariableUsage_iterateScopes(const Scope* const
             if (type == Variables::none || isPartOfClassStructUnion(i->typeStartToken()))
                 continue;
             const Token* defValTok = i->nameToken()->next();
+            if (Token::Match(i->nameToken()->previous(), "* %var% ) (")) // function pointer. Jump behind parameter list.
+                defValTok = defValTok->linkAt(1)->next();
             for (; defValTok; defValTok = defValTok->next()) {
                 if (defValTok->str() == "[")
                     defValTok = defValTok->link();

test/testunusedvar.cpp

@@ -157,6 +157,7 @@ class TestUnusedVar : public TestFixture {
         TEST_CASE(localvarRangeBasedFor); // #7075
         TEST_CASE(localvarAssignInWhile);
         TEST_CASE(localvarTemplate); // #4955 - variable is used as template parameter
+        TEST_CASE(localvarFuncPtr); // #7194
 
         TEST_CASE(localvarCppInitialization);
         TEST_CASE(localvarCpp11Initialization);
@@ -3885,6 +3886,30 @@ class TestUnusedVar : public TestFixture {
         ASSERT_EQUALS("", errout.str());
     }
 
+    void localvarFuncPtr() {
+        functionVariableUsage("int main() {\n"
+                              "    void(*funcPtr)(void)(x);\n"
+                              "}");
+        TODO_ASSERT_EQUALS("[test.cpp:2]: (style) Variable 'funcPtr' is assigned a value never used.\n", "", errout.str());
+
+        functionVariableUsage("int main() {\n"
+                              "    void(*funcPtr)(void);\n"
+                              "}");
+        ASSERT_EQUALS("[test.cpp:2]: (style) Unused variable: funcPtr\n", errout.str());
+
+        functionVariableUsage("int main() {\n"
+                              "    void(*funcPtr)(void)(x);\n"
+                              "    funcPtr();\n"
+                              "}");
+        ASSERT_EQUALS("", errout.str());
+
+        functionVariableUsage("int main() {\n"
+                              "    void(*funcPtr)(void) = x;\n"
+                              "    funcPtr();\n"
+                              "}");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void chainedAssignment() {
         // #5466
         functionVariableUsage("void NotUsed(double* pdD, int n) {\n"