SET MDBG command

Associates a .mdbg file to one load module or DLL.

Read syntax diagramSkip visual syntax diagramSETMDBG ( lm_spec) fileid;
lm_spec
The name of a valid load module or DLL.
fileid
Identifies the .mdbg file that contains the debug information for the load module or DLL.

In z/OS®, fileid is a DD name, a fully qualified partitioned data set and member name, a sequential file, or an HFS or zFS path and file name.

In CICS®, fileid is a fully-qualified data set name or an HFS or zFS path and file name.

If fileid is less than nine characters in length and does not contain a period, z/OS Debugger assumes it is a DD name. z/OS Debugger checks to see if it is allocated. If it is not allocated, then z/OS Debugger assumes fileid is a data set name.

Usage notes

  • Before you can use this command, you or your site must specify YES for the EQAOPTS MDBG command, as described in EQAOPTS commands. In environments that support environment variables, you can use the EQA_USE_MDBG environment variable to override this option for a specific debugging session.
  • You can use this command if you created a .mdbg file that contains debug information, including captured source.
  • You can create .mdbg files that contain debug information, including captured source, only if you compile your program with z/OS XL C/C++, Version 1.10, or later.
  • z/OS Debugger does not search for the .mdbg file specified in fileid until the application loads that load module or DLL. The following list provides some examples of when z/OS Debugger searches for the .mdbg file:
    • If you enter the SET MDBG command and you specify the currently running load module or DLL in lm_spec, z/OS Debugger immediately searches for the .mdbg file specified in fileid. If z/OS Debugger cannot find the file, it displays an error message.
    • You specify the SET MDBG command in your commands file. When your application calls a function in that load module or DLL, then z/OS Debugger searches for the .mdbg file. If z/OS Debugger cannot find the file, it displays an error message.
    • You enter the SET MDBG command, then you set an AT LOAD breakpoint for that load module or DLL. When z/OS Debugger encounters that breakpoint, then it searches for the .mdbg file. If z/OS Debugger cannot find the file, it displays an error message.

Examples

  • Specify that FANAYA.MYLOAD.MDBG is the location of the .mdbg file for load module MYLOAD. z/OS Debugger searches for this file when it needs to retrieve debug information for load module MYLOAD. 
    SET MDBG (MYLOAD) FANAYA.MYLOAD.MDBG;
  • Indicate that the .mdbg file for DLL /u/userid/code/mydll is located in HFS or zFS under the path and file name /u/userid/code/mydll.mdbg: 
    SET MDBG ("/u/userid/code/mydll") /u/userid/code/mydll.mdbg;

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