Metric-CognitiveComplexity

Cognitive Complexity

Required inputs: IR, RFG

Computes the cognitive complexity of routines based on its statement sequence.

The value of Metric.CognitiveComplexity is computed roughly by summing up

• the number of if- and preprocessor if-statements,
• the number of else if- and preprocessor elif-statements,
• the number of else- and preprocessor else-statements,
• the number of loop statements (e.g. for and while),
• the number of conditional (?) operators,
• the number of switch statements,
• the number of catch clauses
• the number of goto-statements
• the number of binary logical operator changes in operator sequences, and
• if the routine is in a static call cycle: the number of routines contained within the cycle.

Additionally a nesting modifier is added, which gets incremented for statements inside

• if-statements or preprocessor if-statements,
• else if- and preprocessor elif-statements,
• else- and preprocessor else-statements,
• loop statements (e.g. for and while),
• conditional (?) operators,
• switch statements,
• catch clauses, and
• lambda expressions.

The nesting modifier gets added to

• if-statements or preprocessor if-statements,
• loop statements (e.g. for and while),
• conditional (?) operators,
• switch statements, and
• catch clauses.

Note: Include guards are ignored by this metric.

Possible Messages

This rule has no predefined messages.

Options

• This rule shares the following common options: exclude_messages_in_system_headers, excludes, includes, justification_checker, post_processing, provider, severity

• This rule shares the following common metric options: excluded_node_types, hierarchy_edge_name, hierarchy_view_name, propagate, report_all_values, report_propagated_values

• The following places define options that affect this rule: Analysis-GlobalOptions

display_name

display_name : str | None = 'Cognitive Complexity'

Description of the metric shown in the dashboard. If None, rfg_metric_name is used.

 

include_disabled_code_sections

include_disabled_code_sections : bool = False

Include code sections that are disabled via preprocessor #if. Does not add routines that where disabled completely. Note: Possibly slow and not 100% accurate due to parsing limitations.

 

include_recursive_call_cycles

include_recursive_call_cycles : bool = True

Whether recursive call cycles should be included in the complexity calculation. If true, 1 plus the number of routines in the cycle will be added to the complexity of a routine if it is part of a recursive call cycle.

 

max_value

max_value : int | None = 20

Maximum allowed value. None if unlimited.

 

min_value

min_value : int | None = 0

Minimum allowed value. None if unlimited.

 

rfg_metric_name

rfg_metric_name : str = 'Metric.CognitiveComplexity'

Name of the node attribute storing the metric value in the RFG.