z/OS Debugger: overview

z/OS® Debugger helps you test programs and examine, monitor, and control the execution of programs that are written in assembler, C, C++, COBOL, PL/I, or Go on a z/OS system. Your applications can include other languages; z/OS Debugger provides a disassembly view where you can debug, at the machine code level, those portions of your application. However, in the disassembly view, your debugging capabilities are limited. Table 1 and Table 2 map out the combinations of compilers and subsystems that z/OS Debugger supports.

You can use z/OS Debugger to debug your programs in batch mode, interactively in full-screen mode, or in remote debug mode.

Table 1 maps out the z/OS Debugger interfaces and compilers or assemblers each interface supports.
Table 1. z/OS Debugger interface type by compiler or assembler
Compiler or assembler Batch mode Full-screen mode Remote debug mode 1
Open Enterprise SDK for Go 1.16     X
Enterprise COBOL for z/OS V3 and V4 compiled with the NOTEST compiler option 2 X X X
Enterprise COBOL for z/OS compiled with the TEST compiler option X X X
Enterprise COBOL for z/OS and OS/390® compiled with the NOTEST compiler option 2 X X  
Enterprise COBOL for z/OS and OS/390 compiled with the TEST compiler option X X X
COBOL for OS/390 & VM X X X
COBOL for MVS™ & VM X X X
AD/Cycle COBOL/370 Version 1 Release 1 X X  
VS COBOL II Version 1 Release 3 and Version 1 Release 4 (with limitations; for programs compiled with the NOTEST compiler option and linked with the Language Environment® library.) 2 X X  
VS COBOL II Version 1 Release 3 and Version 1 Release 4 (with limitations; for programs compiled with the NOTEST compiler option and linked with a non-Language Environment library.) 2 X X  
VS COBOL II Version 1 Release 3 and Version 1 Release 4 (with limitations; for programs compiled with the TEST compiler option and linked with the Language Environment library.) X X X
OS/VS COBOL, Version 1 Release 2.4 (with limitations) 2 X X  
Enterprise PL/I for z/OS compiled with the TEST compiler option X X X
Enterprise PL/I for z/OS and OS/390 compiled with the TEST compiler option X X X
PL/I for MVS & VM X X  
OS PL/I Version 2 Release 1, Version 2 Release 2, and Version 2 Release 3 (with limitations) X X  
C/C++ feature of z/OS X X X
C/C++ feature of OS/390 Version 2 Release 10 and later X X X
C/C++ feature of OS/390 Version 1 Release 3 and earlier X X  
C/C++ for MVS/ESA Version 3 Release 2 X X  
AD/Cycle C/370 Version 1 Release 2 X X  
IBM® High Level Assembler (HLASM), Version 1 Release 4, Version 1 Release 5, and Version 1 Release 6 X X X
Notes:
  1. This column of the table is only applicable for Debug Tool compatibility mode. For standard mode, see Preparing to remote debug in standard mode.
  2. See Preparing a LangX COBOL program for information about how to prepare a program of this type.
Table 2 maps out the z/OS Debugger interfaces and subsystems each interface supports.
Table 2. z/OS Debugger interface type by subsystem
Subsystem Batch mode Full-screen mode Full-screen mode using the Terminal Interface Manager Remote debug mode
TSO X X X X
JES batch X   X X
UNIX System Services     X X
CICS®   X1   X
Db2® X X X X
Db2 stored procedures     X X
IMS TM     X X
IMS batch X   X X
IMS BTS   X X X
Airline Control System (ALCS)       X2
1 You can use 3 different ways to debug CICS programs in full-screen mode:
single terminal mode, screen control mode, and separate terminal mode.
2 Only for C and C++ programs.

Refer to the following topics for more information related to the material discussed in this topic.

  • Related references
  • IBM z/OS Debugger Reference and Messages