gtpg2m0bGeneral Macros

Declarative Macros

The declarative type macros can be divided into three general groups: Data macros, Equate macros, and SIP macros.

Data macros are used to declare the symbolic names used by the source code of programs to refer to fields in some data record. DSECTs are generated by data macros. Any source code that includes the DSECT and uses names declared by the DSECT will have the proper offset values assigned to object code on completion of the assembly process.

Equate macros are used to handle the declaration and assignment of values to system names during the assembly process (offset values for data level fields in the entry control block (ECB), which are names such as D0 and D1, in many control program macros). An equate macro is used to name a collection of assembly EQU instructions. In this way, operational programs can have access to large blocks of system values using a single program statement. The format of an equate macro instruction is simply the name of the equate macro (for example, SYSEQ). Examples of types of data used in equates are the record types in the fixed file, offset values for the data levels in the ECB that are referred to symbolically as D0-DF, maximum lines of output in a given type of display. By using equates, the absolute values can be changed in the macro without having to modify the operational programs (the programs need only be reassembled).

SIP macros are used by the System Initialization Program for processing parameters unique to an installation. They are not used in any other programs.