The linkage editor processes your compiled program (object module) and readies it for execution. The processed object module becomes a load module. Optionally, the linkage editor can process more than one object module or-load module and transform them into a single load module or into multiple load modules by using the NAME linkage editor statement. Creating a Load Module under MVS
The following sample shows the general job control procedure for creating a load module (link-editing).
Creating a Load Module under TSO
To link-edit your program under TSO, use the LINK command. At your terminal, enter the command, followed by the name or names of the object modules you want to link-edit:
The load module is placed by default in member TEMPNAME of the userid.program-name.LOAD data set, unless a NAME card was included in the object modules by using the NAME compiler option. If you want to specify another data set for the resulting load module, code your request this way:
The following example shows how to link-edit two object modules and place the resulting load module in member TEMPNAME of the userid.LM.LOAD data set.
If your program makes external references, you must request that the linkage editor search the library to resolve them. To do this, include in your link request the name of the library to be searched.
A request coded this way, searches SYS1.COB2LIB and SALESL1B.LIB.SUBRT2 to resolve external references.You can also specify link-edit options in the link statement:
Input to the Linkage Editor
Your input to the linkage editor can be:
Primary input to the linkage editor consists of a sequential data set that contains one or more separately compiled object modules, possibly with linkage editor control statements. Specify the primary input data set with the SYSLIN DD statement.
Secondary input to the linkage editor consists of object modules or load modules that are not part of the primary input data set but are to be included in the load module as the automatic call library. The automatic call library" contains load modules or object modules to be used as secondary input to the linkage editor to resolve external symbols left undefined after all primary input has been processed. The automatic call library may be in the form of:
Secondary input is composed of either all object modules or all load modules, but it cannot contain both types.
Specify the secondary input data sets with a SYSL1B DD statement and, if the data sets are object modules, add the linkage editor LIBRARY and INCLUDE control statements. If you have multiple secondary input data sets, concatenate them, as shown in the following example:
In this case, both the COBOL subroutine library and the partitioned data set (library) named SALESLIB are available as the automatic call library. The linkage editor LIBRARY control statement has the effect of concatenating any specified member names with the automatic call library.
Output from the Linkage Editor
SYSLMOD and SYSPRINT are the data sets used for linkage editor output. The output from the linkage editor varies, depending on the options you select, as shown below:
You will always receive diagnostic and informative messages as the result of link-editing. You can get the other output items by specifying options in the PARM parameter in the EXEC statement in your JCL for link-editing.
The load modules created are written in the data set defined by the SYSLMOD DD statement in your JCL for link-editing. All diagnostic output to be listed is written in the data set defined by the SYSPRINT DD statement.
Link-edit options can be specified in either of two ways:
In your JCL for link-edit processing, use the PARM statement to specify link-edit options:
TSO users specify link-edit options through the LINK command. For example, to use the MAP, LET, and NOCALL options when the object module in: ALEX.PRG001.OBJ is placed in ALEX.PRGOOI.LOAD(LM), use the command:
You can use link-edit-options to display a map listing at your terminal:
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