pb-debug

PowerBuilder Debugging Workflow

Systematic Diagnosis

Step 1: Gather Information

• What is the error message or symptom?
• When does it occur? (startup, specific action, data-dependent?)
• Is it reproducible?

Step 2: Locate the Code

1. Use pb_search_code to find the error message text in source
2. Use pb_get_call_graph to trace function calls
3. Use pb_read_object to read the full source of suspected objects

Step 3: Analyze the Context

1. Check pb_get_inheritance — is the issue in an ancestor?
2. Check pb_get_dependencies — is the issue caused by a caller?
3. Review the DataWindow SQL if the issue involves data (pb_get_datawindow_sql)

Step 4: Common PB Error Patterns

Null object reference:

• Check if object is created/instantiated before use
• Check if destroy was called prematurely
• Check IsValid() before accessing object properties

SQL errors:

• Check SQLCA.SQLCode after database operations (-1 = error)
• Check SQLCA.SQLErrText for the error message
• Verify DataWindow SQL syntax via pb_get_datawindow_sql

Runtime errors:

• Check event firing order (open vs. constructor vs. activate)
• Check for division by zero
• Check array bounds

Step 5: Propose and Apply Fix

1. Explain the root cause clearly
2. Use the pb-modify skill workflow to apply the fix
3. Compile and verify