How does z/OS Debugger locate EQALANGX files

An EQALANGX file, which contains debug information for an assembler or LangX COBOL program, might be read more than once but it is always read from the same data set. After z/OS® Debugger locates a valid EQALANGX file, you cannot direct z/OS Debugger to a different EQALANGX file. After you enter the LOADDEBUGDATA (LDD) command (which is run immediately or run when the specified CU becomes known to z/OS Debugger), z/OS Debugger looks for the EQALANGX file in the following order:

  1. SET SOURCE command
  2. a previously loaded EQALANGX file that contains a CSECT that matches the name and length of the program
  3. default data set name. If a data set with the default data set name cannot be located, and if the EQAUEDAT user exit is implemented and a EQADEBUG DD statement is not specified, the data set name might be modified by the EQAUEDAT user exit.
  4. SET DEFAULT LISTINGS command. If the EQAUEDAT user exit is implemented and a EQADEBUG DD statement is not specified, the data set name might be modified by the EQAUEDAT user exit.
  5. the EQADEBUG DD statement
Note: If z/OS Debugger detects a Language Environment-enabled EQAUEDAT when Language Environment is not active, the exit will not be started.

The SET SOURCE command can be entered during any of the following situations:

  • Any time after the CU name appears as a disassembly CU.
  • If the CU is known when the LDD command is entered but then z/OS Debugger does not find the EQALANGX file.
  • If the CU is not known to z/OS Debugger when the LDD command is entered and then z/OS Debugger runs the LDD after the CU becomes known to z/OS Debugger.

The SET DEFAULT LISTINGS command can be entered any time before you enter the LDD command or, if the EQALANGX file is not found by the LDD command, after you enter the LDD command.