Overview of IBM z/OS Debugger

IBM® z/OS® Debugger is the next iteration of IBM debug technology on IBM Z and consolidates the IBM Integrated Debugger and IBM Debug Tool engines into one unified technology.

IBM z/OS Debugger is a host component that supports various debug interfaces, such as Eclipse and Visual Studio Code IDEs. IBM z/OS Debugger and the supported debug interfaces are provided with the following products:
IBM Developer for z/OS Enterprise Edition
This product is included in IBM Application Delivery Foundation for z/OS. IBM Developer for z/OS Enterprise Edition provides all the debug features.
IBM Developer for z/OS Enterprise Edition currently provides debug functions in the following integrated development environments (IDEs):
  • IBM Developer for z/OS on VS Code, through IBM Z® Open Debug
  • IBM Developer for z/OS on Eclipse
IBM Developer for z/OS Select
This product is a software bundle that contain a subset of IBM Developer for z/OS Enterprise Edition capabilities. It includes debug functions in the following integrated development environments (IDEs) except for the features noted in Table 1.
  • IBM Developer for z/OS on VS Code, through IBM Z Open Debug
  • IBM Developer for z/OS on Eclipse
IBM Developer for z/OS
IBM Developer for z/OS is a subset of IBM Developer for z/OS Enterprise Edition. IBM Developer for z/OS, previously known as IBM Developer for z Systems or IBM Rational® Developer for z Systems®, is an Eclipse-based integrated development environment for creating and maintaining z/OS applications efficiently.
IBM Developer for z/OS includes all enhancements in IBM Developer for z/OS Enterprise Edition except for the debug features noted in Table 1.
IBM Debug for z/OS
IBM Debug for z/OS is a subset of IBM Developer for z/OS Enterprise Edition. IBM Debug for z/OS focuses on debugging solutions for z/OS application developers. See Table 1 for the debug features supported.
IBM Debug for z/OS does not provide advanced developer features that are available in IBM Developer for z/OS Enterprise Edition.
For information about how to install the IBM Debug for z/OS Eclipse IDE, see Installing the IBM Debug for z/OS Eclipse IDE.
IBM Test Accelerator for Z
IBM Test Accelerator for Z is a comprehensive test automation and generation framework purpose-built for z/OS developers and testers.
IBM Test Accelerator for Z primarily includes the Dynamic Test Engine feature from z/OS Debugger, integration for debugging and collecting code coverage of tests in the IDE and a command line interface for tests created with IBM Test Accelerator for Z.
IBM Bob Premium Package for Z
IBM Bob Premium Package for Z is an extension that can be installed within IBM Bob. This premium package accelerates mainframe application development and modernization with AI and automation.
IBM Bob Premium Package for Z includes IBM Z Open Debug and Code Coverage features that can be used in the Visual Studio Code IDE.
Table 1 maps out the features that differ in products. Not all the available features are listed. To find the features available in different remote IDEs, see Table 2 and Table 3.
Table 1. Debug feature comparison
  IBM Debug for z/OS IBM Developer for z/OS IBM Developer for z/OS Select IBM Developer for z/OS Enterprise Edition IBM Test Accelerator for Z IBM Bob Premium Package for Z
Main features  
3270 interface, including z/OS Debugger Utilities √     √    
Eclipse IDE, see Table 2 for feature details.1 √ √ √ √ √6  
Visual Studio Code IDE (IBM Z Open Debug), see Table 2 for feature details.1     √ √ √6 √
Code Coverage features  
Eclipse IDE, see Table 3 for feature details.1,2 √ √ 3 √ √ √6  
Headless Code Coverage √ √ √ √ √6  
Visual Studio Code IDE (IBM Compiled Code Coverage), see Table 3 for feature details.1, 2     √ √ √6 √
3270 features  
z/OS Debugger full screen, batch or line mode √     √    
IMS Isolation support √     √ √6  
Test Command Line Interface         √6  
Compiler support features  
Assembler support: Create EQALANGX files √ √ √ √    
Assembler support: Debugging 4 √ √ √ √    
LangX COBOL support 5 √ √ √ √    
Support for Automatic Binary Optimizer (ABO) √ √ √ √    
Notes:
  1. The following features are supported only in remote debug mode:
    • Support for 64-bit COBOL feature of z/OS for COBOL v6.3 and later
    • Support for 64-bit Enterprise PL/I for z/OS Version 5 and later
    • Support for 64-bit C/C++ feature of z/OS
    • Support for Open Enterprise SDK for Go 1.21, 1.22, 1.23, 1.24 and 1.25.
    • Support for Open XL C/C++ v1.1 for z/OS
  2. Code coverage does not support Go programs.
  3. IBM Developer for z/OS includes z/OS Debugger remote debug and compiled code coverage Eclipse interface.
  4. Debugging assembler requires that you have EQALANGX files that have been created via ADFz Common Components or a product that ships the ADFz Common Components.
  5. LangX COBOL refers to any of the following programs:
    • A program compiled with the IBM OS/VS COBOL compiler.
    • A program compiled with the IBM VS COBOL II compiler with the NOTEST compiler option.
    • A program compiled with the IBM Enterprise COBOL for z/OS 3, 4, or 6 compiler with the NOTEST compiler option.
  6. When only a registration for IBM Test Accelerator for Z exists, you can only debug or run code coverage against unit tests, regardless of IDE or 3270.
Table 2. Remote IDE debug feature comparison
Feature Eclipse-based debug interface IBM Z Open Debug 1,6
Integration with Language Editors2
  • COBOL Editor2
  • PL/I Editor2
  • Remote C/C++ Editor2
  • System z LPEX Editor2
  • Z Open Editor
Visual Debug √2,6  
Debug profile management √6 √
IMS Isolation UI √3  
Integration with CICS Explorer views √ 2  
Integration with property groups √2,6  
Integrated launch6
  • z/OS UNIX Application launch configuration
  • z/OS Batch Application using existing JCL
  • z/OS Batch Application using a property group
  • IBM Test Accelerator for Z Unit Test Early Development Testing launch configurations
  
Content Assist for JCL   √
Modules √  
Memory √  
Program navigation
Step over/Next √ √
Step into/Step in √ √
Step return/Step out √ √
Jump to location √6  
Run to location/Run to cursor √6 √
Resume/Continue √ √
Terminate √ √
Animated step √  
Playback √6  
Breakpoints
Statement breakpoints √ √
Entry breakpoints √  
Source entry breakpoints √6  
Event breakpoint √6  
Address breakpoint √6  
Watch breakpoint √6  
Variables & Registers
Variables √ √
Registers √ √4
Modifying variable and register values √ √
Setting variable filter √5  
Changing variable representation √  
Displaying in memory view √  
Monitors
Displaying monitor √ √
Modifying monitor value √  
Changing variable representation √  
Debug Console
Evaluating variables and expressions   √
z/OS Debugger commands √6  
Notes:
  1. IBM Z Open Debug is provided with IBM Developer for z/OS on VS Code.
  2. This feature is not available in IBM Debug for z/OS.
  3. This feature is only available in IBM Developer for z/OS Enterprise Edition.
  4. Registers are available in the Variables view.
  5. The automonitor filters do not support programs complied with Open Enterprise SDK for Go or Open XL C/C++ for z/OS.
  6. Programs compiled with IBM Open Enterprise SDK for Go are not supported.
Table 3. Remote IDE code coverage feature comparison
Feature Eclipse-based code coverage interface IBM Compiled Code Coverage 1,2
Reports √ √
Integration with Language Editors2
  • COBOL Editor2
  • PL/I Editor2
  • Remote C/C++ Editor2
  • System z LPEX Editor2
 Web view only
Integration with property groups √ 3
Integrated launch (2)
  • z/OS UNIX Application launch configuration
  • z/OS Batch Application using existing JCL
  • z/OS Batch Application using a property group
  • Test Accelerator for Z Early Development Testing for Eclipse Unit Test launch configurations
  • Test Accelerator for Z Early Development Testing for VS Code Unit Test execution
Content Assist for JCL √
Locations
  • Workspace
  • RSE
  • Local
  • CCS
  • CCS
Results
  • Open
  • Filter
  • Compare
  • Rename
  • Delete
  • Export (CCZip, SonarQube, PDF, Cobertura)
  • Import
  • Properties
  • Open
  • Delete
  • Rename
  • Export (PDF)
  • Properties
Threshold configuration √  
Concurrent Debug and Code Coverage √  
Notes:
  1. IBM Z Open Debug is provided with IBM Developer for z/OS on VS Code
  2. Programs compiled with IBM Open Enterprise SDK for Go are not supported.
  3. This feature is not available in IBM Debug for z/OS.