gitnexus-pdg-query

To query control and data dependence, you execute a pdg_query against your codebase to analyze CDG edges for control flow and REACHING_DEF edges for data flow. This identifies what controls a statement and where variables flow.

A data flow query might return empty if PDG layers are not enabled in your GitNexus codebase, or the target variable lacks REACHING_DEF edges. You can use this Skill to trace the variable within the function and understand why the pdg_query result is empty.

Control flow analysis finds guard clauses by querying CDG edges to identify early-return guards in your code. This reveals which conditions control the execution path leading to those early exits.

Yes, you need a GitNexus codebase with PDG layers enabled to analyze data flow and control dependence. This environment provides the necessary CDG and REACHING_DEF edge surface for the pdg_query tool to function.

You can trace a variable within a function by running a pdg_query for REACHING_DEF edges to map its data flow. This allows you to see exactly where the variable is defined and how it reaches subsequent operations.

In code analysis, CDG edges represent control dependence showing what conditions govern a statement, while REACHING_DEF edges represent data dependence showing variable definitions reaching subsequent uses, together providing full program dependence surface coverage.