Macros and SVCs

Restriction: This topic applies to Windows environments only.

Assembler support incorporates a number of macros and SVCs (supervisor calls). Those that are supported are, in general, not compatible with the equivalent macros and SVCs on the mainframe, so wherever possible, use macros to get the desired SVC function.

Some macro options are not fully supported in that they do compile, but have no effect when executed. There are also some macros which are supported in stub form, that is, macro code exists but it simply returns control to the calling program. These stubs are provided for macros that perform tasks that have no meaning on the PC. An example stub macro is provided in %ProgramFiles(x86)%\Micro Focus\Enterprise Developer\include\stub.mac; you can use this to create your own stub macros.

There are two categories of macro:

Assembler services macros. These provide services for interfacing with the Assembler run-time system, managing memory, calling other programs and for general functions such as saving and restoring registers. There are also services for accessing the catalog and for dynamically allocating and deallocating data sets at execution time.
File handling macros. These provide access to files.

Many Assembler services macros equate to SVCs. You can choose whether to code the macro or its equivalent SVC, but in general it is easier to use the macros. The following table relates the SVCs and service macros:

SVC	Macro	Description
4	GETMAIN L LC LU E EC EU, VC, VU	Get memory (list, element and variable requests).
5	FREEMAIN L LC LU E EC EU, VC, VU	Free memory (list, element and variable requests).
6	LINK	Link to another Assembler program.
8	LOAD	Load another Assembler program or a COBOL program.
9	DELETE	Delete a loaded module.
10	GETMAIN R	Get memory (R type register requests).
11	TIME	Get the time of day and the date.
13	ABEND	Terminate the program and open the Assembler debugger if possible, or display information about the state of the program when the abend occurred.
14	SPIE	Handle a program exception within the executing module.
26	CATALOG and LOCATE	Uncatalog a data set; return a volume list for a data set.
29	SCRATCH	Delete a data set.
35	WTO WTOR	Display a message on the screen. Display a message on the screen and wait for a reply.
39	LINKC2	Link to a COBOL program.
41	IDENTIFY	Associate a name you specify with an already loaded program.
62		Remove the executing program. There is no corresponding macro.
99	DYNALLOC	Allocate or deallocate a resource at execution time.
103	XLATE	Convert between ANSI and EBCDIC.
120	GETMAIN RU, RC, VRC, VRU; FREEMAIN R, RU, RC, VRC and VRU; STORAGE	Get memory (RU and RC type register requests) Free memory (all types of register requests). Get memory or free memory
	CALL	Transfer control to a statically linked module. There is no corresponding SVC.
	CAMLST	Create parameter list for CATALOG, LOCATE or SCRATCH. There is no corresponding SVC.
	DEQ	Relinquish control of one or more serially reusable resources. There is no corresponding SVC.
	ENQ	Request control of one or more serially reusable resources. There is no corresponding SVC.
	EXTRACT	Obtain information from control block. There is no corresponding SVC.
	RETURN	Restore registers and sets the address to return to. There is no corresponding SVC.
	SAVE	Save registers. There is no corresponding SVC.
	SPLEVEL	Test or set the level of MVS macro compatibility. There is no corresponding SVC.
	WAIT	Wait for event completion. There is no corresponding SVC.