Cognitive complexity metric does not understand newer C++ syntax

[Patschkowski]

Describe the bug
Code complexity metric is counting r-value references as logical operators and "=default" as switch labels.

Expected behavior
Code complexity metric does not count r-value references as logical operators and "=default" as switch labels.

Screenshots

Desktop (please complete the following information):

• OS: Windows
• SonarQube version: 10.4.1 (build 88267)
• cxx plugin version: 2.2 (build 626)
• sonar-scanner version: 5.0.1.3006

[guwirth]

Hello @Patschkowski, thanks for the feedback …

[guwirth]

Hi @Patschkowski,

most likely the problem is somewhere here: https://github.com/SonarOpenCommunity/sonar-cxx/blob/master/cxx-squid/src/main/java/org/sonar/cxx/visitors/CxxCognitiveComplexityVisitor.java

Can you confirm, that it’s a problem with cognitive complexity?

Regards,

[Patschkowski]

Hi @guwirth , I'd say it is Cyclomatic Complexity

[guwirth]

Hello @Patschkowski,

there are metrics (Measues) and rule violations (Issues) in SonarQube. The first screenshot you sent seems to show the cognitive complexity metric. The second one is a complexity rule violation. These are two different things created in a different way. Also the visitor verifying the AST is for cognitive and cyclomatic complexity a different one. The reason why I’m asking is to narrow down the problem.

Regards,

[Patschkowski]

Hi @guwirth

appreciate your explanation. I think it is the Cyclomatic Complexity though:

[guwirth]

Hi @Patschkowski,

thx for clarification! Can you copy me the source code of this one template host of the screenshot above into this ticket please. Makes testing easier…

Regards,

[Patschkowski]

#include <memory>

template<typename T>
class host :
  public std::enable_shared_from_this<host<T>> {
public:
  template<typename... U>
  explicit host(U&&... args);

  host() = delete;

  host(const host&) = delete;

  host(host&&)      = default;

  host& operator=(const host&) = delete;

  host& operator=(host&&)      = default;
};

[guwirth]

Think problem is that CxxCognitiveComplexityVisitor.java is using functionDefinition as root node. Maybe functionBody with child compoundStatement would be better?

[guwirth]

@Patschkowski fixed with #2675, you can test it with https://github.com/SonarOpenCommunity/sonar-cxx/releases/tag/latest-snapshot