Fixed #7026 (Cppcheck does not recognizes the use of a variabile inside lambda function)

lib/checkleakautovar.cpp

@@ -140,7 +140,7 @@ void CheckLeakAutoVar::check()
     const std::size_t functions = symbolDatabase->functionScopes.size();
     for (std::size_t i = 0; i < functions; ++i) {
         const Scope * scope = symbolDatabase->functionScopes[i];
-        if (scope->hasInlineFunction())
+        if (scope->hasInlineOrLambdaFunction())
             continue;
 
         // Empty variable info

lib/checkmemoryleak.cpp

@@ -2177,7 +2177,7 @@ void CheckMemoryLeakInFunction::check()
     const std::size_t functions = symbolDatabase->functionScopes.size();
     for (std::size_t i = 0; i < functions; ++i) {
         const Scope * scope = symbolDatabase->functionScopes[i];
-        if (!scope->hasInlineFunction())
+        if (!scope->hasInlineOrLambdaFunction())
             checkScope(scope->classStart->next(), "", 0, scope->functionOf != nullptr, 1);
     }
 
@@ -2197,7 +2197,7 @@ void CheckMemoryLeakInFunction::check()
         if (var->isPointer() && var->type() && !var->typeScope())
             continue;
 
-        if (var->scope()->hasInlineFunction())
+        if (var->scope()->hasInlineOrLambdaFunction())
             continue;
 
         unsigned int sz = _tokenizer->sizeOfType(var->typeStartToken());

lib/checkunusedvar.cpp

@@ -1136,6 +1136,11 @@ void CheckUnusedVar::checkFunctionVariableUsage()
     for (std::size_t i = 0; i < functions; ++i) {
         const Scope * scope = symbolDatabase->functionScopes[i];
 
+        // Bailout when there are lambdas or inline functions
+        // TODO: Handle lambdas and inline functions properly
+        if (scope->hasInlineOrLambdaFunction())
+            continue;
+
         // varId, usage {read, write, modified}
         Variables variables;
 

lib/symboldatabase.cpp

@@ -3493,13 +3493,16 @@ const Type* SymbolDatabase::findVariableType(const Scope *start, const Token *ty
     return nullptr;
 }
 
-bool Scope::hasInlineFunction() const
+bool Scope::hasInlineOrLambdaFunction() const
 {
     for (std::list<Scope*>::const_iterator it = nestedList.begin(); it != nestedList.end(); ++it) {
         const Scope *s = *it;
         // Inline function
         if (s->type == Scope::eUnconditional && Token::Match(s->classStart->previous(), ") {"))
             return true;
+        // Lambda function
+        if (s->type == Scope::eLambda)
+            return true;
     }
     return false;
 }

lib/symboldatabase.h

@@ -899,7 +899,7 @@ public:
     }
 
     // Is there lambda/inline function(s) in this scope?
-    bool hasInlineFunction() const;
+    bool hasInlineOrLambdaFunction() const;
 
     /**
      * @brief find a function

test/testunusedvar.cpp

@@ -168,6 +168,8 @@ private:
         TEST_CASE(crash1);
         TEST_CASE(crash2);
         TEST_CASE(usingNamespace);     // #4585
+
+        TEST_CASE(lambdaFunction); // #5078
     }
 
     void checkStructMemberUsage(const char code[]) {
@@ -3192,38 +3194,6 @@ private:
                               "}");
         ASSERT_EQUALS("", errout.str());
 
-        functionVariableUsage("void foo() {\n"
-                              "    int i = -1;\n"
-                              "    int a[] = {1,2,3};\n"
-                              "    FOREACH_X (int x, a) {\n"
-                              "        i = x;\n"
-                              "    }\n"
-                              "}");
-        ASSERT_EQUALS("[test.cpp:5]: (style) Variable 'i' is assigned a value that is never used.\n", errout.str());
-
-        functionVariableUsage("void foo() {\n"
-                              "    int i = -1;\n"
-                              "    int a[] = {1,2,3};\n"
-                              "    X (int x, a) {\n"
-                              "        if (i==x) return x;\n"
-                              "        i = x;\n"
-                              "    }\n"
-                              "}");
-        ASSERT_EQUALS("[test.cpp:6]: (style) Variable 'i' is assigned a value that is never used.\n", errout.str());
-
-        // #4956 - assignment in for_each
-        functionVariableUsage("void f(std::vector<int> ints) {\n"
-                              "  int x = 0;\n"
-                              "  std::for_each(ints.begin(), ints.end(), [&x](int i){ dostuff(x); x = i; });\n"
-                              "}");
-        ASSERT_EQUALS("", errout.str());
-
-        functionVariableUsage("void f(std::vector<int> ints) {\n"
-                              "  int x = 0;\n"
-                              "  std::for_each(ints.begin(), ints.end(), [&x](int i){ x += i; });\n"
-                              "}");
-        ASSERT_EQUALS("[test.cpp:3]: (style) Variable 'x' is assigned a value that is never used.\n", errout.str());
-
         // #5154 - MSVC 'for each'
         functionVariableUsage("void f() {\n"
                               "  std::map<int,int> ints;\n"
@@ -3969,6 +3939,38 @@ private:
                               "}"); // #4585
         ASSERT_EQUALS("", errout.str());
     }
+
+    void lambdaFunction() {
+        // #7026
+        functionVariableUsage("void f() {\n"
+                              "  bool first = true;\n"
+                              "\n"
+                              "  auto do_something = [&first]() {\n"
+                              "    if (first) {\n"
+                              "      first = false;\n"
+                              "    } else {\n"
+                              "      dostuff();\n"
+                              "    }\n"
+                              "  };\n"
+                              "  do_something();\n"
+                              "  do_something();\n"
+                              "}");
+        ASSERT_EQUALS("", errout.str());
+
+
+        // #4956 - assignment in for_each
+        functionVariableUsage("void f(std::vector<int> ints) {\n"
+                              "  int x = 0;\n"
+                              "  std::for_each(ints.begin(), ints.end(), [&x](int i){ dostuff(x); x = i; });\n"
+                              "}");
+        ASSERT_EQUALS("", errout.str());
+
+        functionVariableUsage("void f(std::vector<int> ints) {\n"
+                              "  int x = 0;\n"
+                              "  std::for_each(ints.begin(), ints.end(), [&x](int i){ x += i; });\n"
+                              "}");
+        TODO_ASSERT_EQUALS("[test.cpp:3]: (style) Variable 'x' is assigned a value that is never used.\n", "", errout.str());
+    }
 };
 
 REGISTER_TEST(TestUnusedVar)