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 progressing towards one remote debug mode based on Debug Tool compatibility mode. In support of this direction, Debug Tool compatibility mode, when available in the user interface, is selected by default for V14.1.2 or later.

IBM z/OS Debugger is a host component that supports various debug interfaces, like the Eclipse and Visual Studio Code IDEs. 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 IDEs:
  • IBM Developer for z/OS Eclipse
  • Wazi for Dev Spaces, through IBM Z® Open Debug
  • Wazi for VS Code, through IBM Z Open Debug
See Table 2 for the debug features supported in different IDEs.
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 Z and Cloud Modernization Stack
IBM Z and Cloud Modernization Stack brings together component capabilities from IBM Z into an integrated platform that is optimized for Red Hat OpenShift Container Platform. With this solution, you can analyze the impact of application changes on z/OS, create and deploy APIs for z/OS applications, work on z/OS applications with cloud native tools, and standardize ID automation for z/OS. Starting from 2.0, Wazi Code is delivered in IBM Z and Cloud Modernization Stack. Wazi Code 1.x is still available in IBM Wazi Developer for Red Hat CodeReady Workspaces.
The debug functions are available in the IDEs provided with Wazi Code:
  • Wazi for Dev Spaces, through IBM Z Open Debug
  • Wazi for VS Code, through IBM Z Open Debug
  • Wazi for Eclipse
See Table 1 and Table 2 for the debug features supported in the product and different IDEs.
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.
Table 1. Debug feature comparison
  IBM Debug for z/OS IBM Developer for z/OS IBM Developer for z/OS Enterprise Edition IBM Z and Cloud Modernization Stack (Wazi Code)
Main features
3270 interface, including z/OS Debugger Utilities √   √  
Eclipse IDE, see Table 2 for feature details.1 √ √ √ √
IBM Z Open Debug provided with the Wazi for Dev Spaces IDE, see Table 2 for feature details.1     √ √
IBM Z Open Debug provided with the Wazi for VS Code IDE, see Table 2 for feature details.1     √ √
Code Coverage features
Compiled Language Code Coverage2 √ √ 3 √  
Headless Code Coverage √ √ √  
Java™ Code Coverage   √ √  
ZUnit Code Coverage4   √ √  
z/OS Debugger Code Coverage (3270 and remote interfaces) 5 √   √  
3270 features    
z/OS Debugger full screen, batch or line mode √   √  
IMS Isolation support √   √  
Compiler support features
Assembler support: Create EQALANGX files √ √ √  
Assembler support: Debugging 6 √ √ √7 √7
LANGX COBOL support 8 √ √ √  
Support for Automatic Binary Optimizer (ABO) √ √ √  
Load Module Analyzer9 √   √  
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
    • Support for 64-bit C/C++ feature of z/OS
    • Support for IBM Open Enterprise SDK for Go 1.16.
  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, but does not include z/OS Debugger Code Coverage.
  4. ZUnit Code Coverage is only supported in Debug Tool compatibility mode.
  5. z/OS Debugger Code Coverage can only be enabled in the 3270 interface.
  6. 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.
  7. This feature is only available with the Eclipse IDE.
  8. 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 Version 3 or Version 4 compiler with the NOTEST compiler option.
  9. Load Module Analyzer is deprecated and will be removed in a future version.
Table 2. Remote IDE debug feature comparison
Feature Eclipse-based debug interface IBM Z Open Debug 1,10
Debug Tool compatibility mode2 √ √
Standard mode3,10 √4  
Integration with Language Editors10
  • COBOL Editor5
  • PL/I Editor5
  • Remote C/C++ Editor4,5
  • System z LPEX Editor4,5
  • Z Open Editor
Visual Debug √5,10  
Debugging ZUnit tests √6,10  
Debug profile management √4,10 √
IMS Isolation UI √7  
Integration with CICS Explorer views √ 4,5  
Integration with property groups √5,10  
Team Debug support √4,5  
Integrated launch10
  • z/OS UNIX Application launch configuration
  • z/OS Batch Application using existing JCL
  • z/OS Batch Application using a property group5
  
Debug Tool Plug-ins √4, 8  
Modules √  
Memory √  
Program navigation
Step over/Next √ √
Step into/Step in √ √
Step return/Step out √ √
Jump to location √10  
Run to location/Run to cursor √10 √
Resume/Continue √ √
Terminate √ √
Animated step √  
Playback √10  
Breakpoints
Line/statement breakpoints √ √
Entry breakpoints √  
Source entry breakpoints √10  
Event breakpoint √10  
Address breakpoint √10  
Watch breakpoint √10  
Variables & Registers
Variables √ √
Registers √ √9
Modifying variable and register values √ √
Setting variable filter √  
Changing variable representation √  
Dereferencing variables √  
Displaying in memory view √  
Monitors
Displaying monitor √ √
Modifying monitor value √  
Changing variable representation √  
Dereferencing variables √  
Debug Console
Evaluating variables and expressions   √
z/OS Debugger commands √10  
Notes:
  1. IBM Z Open Debug is provided with Wazi for Dev Spaces and Wazi for VS Code.
  2. Debug Tool compatibility mode does not support 64-bit Enterprise PL/I for z/OS Version 5.
  3. Standard mode does not support 64-bit COBOL feature of z/OS for COBOL V6.3 and later. Source view for COBOL V6.2 and later is supported only in standard mode.
  4. This feature is not available in Wazi for Eclipse.
  5. This feature is not available in IBM Debug for z/OS.
  6. Debugging ZUnit tests is only supported in Debug Tool compatibility mode.
  7. This feature is only available in IBM Developer for z/OS Enterprise Edition.
  8. IBM Developer for z/OS includes Debug Tool plug-ins, but does not include Load Module Analyzer and z/OS Debugger Code Coverage 3270 interfaces.
  9. Registers are available in the Variables view.
  10. Programs compiled with IBM Open Enterprise SDK for Go are not supported.