Trace modifications to the executable code in a CSECT

You can list the information in a load module or program object's CSECT identification records (IDRs). An IDR provides the following information:

The version and modification level of the language translator and the date that each CSECT was translated. (Translation data is available only for CSECTs that were produced by a translator that supports IDR generation.)
The version and modification level of the linkage editor or binder that built the load module or program object and gives the date the load module or program object was created.
Modifications to the load module or program object, by date, that might have been done using SPZAP.

An IDR might also contain optional user-supplied data.

To trace modifications, invoke AMBLIST with the LISTIDR control statement. For sample output, see LISTIDR output.

In Figure 1, AMBLIST is used to list the CSECT identification records in several load modules or program objects.

Figure 1. Example: Listing IDR information for several load modules

   //IDRLIST     JOB     MSGLEVEL=(1,1)
   //LISTSTEP    EXEC    PGM=AMBLIST,REGION=64K
   //SYSPRINT    DD      SYSOUT=A
   //SYSLIB      DD      DSN=SYS1.LINKLIB,DISP=SHR
   //LOADLIB     DD      DSN=LOADMODS,DISP=SHR
   //SYSIN       DD      *
       LISTIDR   TITLE=('IDR LISTINGS OF ALL MODS IN LINKLIB',20)
       LISTIDR   OUTPUT=IDENT,DDN=LOADLIB,MEMBER=TESTMOD
                 TITLE=('LISTING OF MODIFICATIONS TO TESTMOD',20)
       LISTIDR   OUTPUT=ALL,DDN=LOADLIB,MEMBER=(MOD1,MOD2,MOD3),
                 TITLE=('IDR LISTINGS OF MOD1 MOD2 MOD3',20)
       LISTIDR   DDN=LOADLIB,MODLIB
   /*

SYSLIB DD Statement: Defines an input data set, SYS1.LINKLIB, that contains load modules or program objects to be processed.
LOADLIB DD Statement: Defines a second input data set.
SYSIN DD Statement: Defines the data set (in the input stream) containing the AMBLIST control statements.
LISTIDR Control Statement #1: Instructs AMBLIST to list all CSECT identification records for all modules in SYS1.LINKLIB (this is the default data set since no DDN parameter was included). It also specifies a title for each page of output, to be indented 20 characters from the left margin.
LISTIDR control statement #2: Instructs AMBLIST to list CSECT identification records that contain SPZAP or user-supplied data for the load module or program object named TESTMOD. TESTMOD is a member of the data set defined by the LOADLIB DD statement. This control statement also specifies a title for each page of output, to be indented 20 characters from the left margin.
LISTIDR control statement #3: Instructs AMBLIST to list all CSECT identification records for of the load modules or program objects MOD1, MOD2, and MOD3. These are members in the data set defined by the LOADLIB DD statement. This control statement also specifies a title for each page of output, to be indented 20 characters from the left margin.
LISTIDR control statement #4: Instructs AMBLIST to list CSECT identification records that contain SPZAP or user-supplied data for the LOADLIB data set. The module summary print out is suppressed.