Guide to the HP Structure Definition Language

The HP MACRO output routine produces declarations that can generate either local symbol or global symbol definitions. The following is an example of HP SDL source code:

MODULE simple; CONSTANT bits EQUALS 4; ITEM field BYTE PREFIX tst$ COMMON; END_MODULE;

The following is the resulting HP MACRO output:

.MACRO simple,..EQU=<=>,..COL=<:> bits'..equ'4 .SAVE .PSECT tst$b_field PIC,OVR,REL,GBL,- SHR,NOEXE,RD,WRT,LONG tst$b_field'..col' <P>lkb 1 .RESTORE ; tst$b_field'..equ'0 .ENDM

When the macro is invoked without arguments, the resulting local definitions are as follows:

bits = 4 tst$b_field1: blkb 1

To generate these names as global symbols, invoke the macro with the arguments <= => and <::>, as follows:

simple ..EQU=<==> ..COL=<::>

This invocation results in the following definitions:

bits == 4 tst$b_field1:: blkb 1

The HP MACRO output routine always generates a size variable for bitfields, aggregates, arrays, and character strings, using the tag S_ preceding the output identifier.

The /VMS_DEVELOPMENT qualifier on the SDL command produces special forms of macros for entry point declarations.

Note

Each identifier produces a constant assignment equal to the byte offset of the item, as follows:
name = offset-value
Offset-value is the byte offset relative to the origin of the level-1 aggregate. A constant assignment of the following form gives the size in bytes for aggregates, arrays, and character strings:
prefix$_name = byte-size
If /VMS_DEVELOPMENT was specified, the CONSTANT x EQUALS STRING "s" declaration translates to the following:
.SAVE .PSECT module_name_STRCONST PIC,CON,REL,NOEXE,GBL,SHR,RD,NOWRT,LONG $EQU S_x size $DEF x .ASCII /s/ .RESTORE
If /NOVMS_DEVELOPMENT was specified (default), this declaration translates to the following:
.SAVE .PSECT module_name STRCONST PIC,CON,REL,NOEXE,GBL,SHR,RD,NOWRT,LONG S_x ..equ'size x'..col' .ASCII /s/ .RESTORE
where size represents the number of bytes in the string.
Note:
- If the string contains the / character, another delimiter character (pulled from a priority list) is used.
- If the length of the PSECT name exceeds 31 characters after appending _STRCONST, the module_name is truncated appropriately before appending _STRCONST.

HP Pascal Translation Summary

The following table shows the HP SDL to HP Pascal language translation summary.

HP SDL Declaration HP Pascal Output

MODULE name IDENT string (*** MODULE name IDENT string ***)

Note that when /MODULE is used, a HP Pascal MODULE statement of the form MODULE name; is generated.

/* comment (* comment *)

CONSTANT x

EQUALS n; CONST x = n;

EQUALS STRING "s"; CONST x = 's';

ENTRY [ASYNCHRONOUS] FUNCTION

[ASYNCHRONOUS] PROCEDURE

PARAMETER (type,...) (formal param_list)

ANY %REF param-name: [UNSAFE] ARRAY [$l1..$u1:INTEGER] OF $UBYTE

DESCRIPTOR [CLASS_S] for scalars;

[CLASS_S] for CHARACTER LENGTH 1;

[CLASS_A] for nonscalars;

%DESCR for fixed-length VARYING;

RTL_STR_DESC PACKED ARRAY [$l1..$u1:INTEGER] OF CHAR;

IN Default semantics (unless overridden by OUT)

OUT (or IN OUT) VAR, except for CHARACTER LENGTH * and ANY (which generate %REF)

NAMED param-name Parameter name. If none is given, names will be generated of the form $P1,...$Pn.

VALUE %IMMED

REFERENCE %REF for CHARACTER LENGTH * and ANY; VAR for all others if mode OUT or IN OUT; otherwise (IN only) default mechanism

DEFAULT n := %IMMED value

LIST If OPTIONAL is not specified, generates one required parameter followed by a parameter with the [LIST] attribute; if OPTIONAL is specified, only the parameter with [LIST] is generated.

OPTIONAL :=%IMMED 0

TYPENAME type-name n/a

RETURNS return-data-type FUNCTION name : data-type;

NAMED param-name n/a

VARIABLE n/a

ALIAS internal-name Results in [EXTERNAL (entry-name)] and internal-name being used as entry-name

LINKAGE n/a

TYPENAME type-name n/a

STRUCTURE RECORD

UNION RECORD CASE INTEGER OF

0: ...

.

.

n: ...

BYTE [SIGNED ] $BYTE--- [BYTE ] -128..127

INTEGER _BYTE [SIGNED ] $BYTE--- [BYTE ] -128..127

WORD [SIGNED ] $WORD--- [WORD ] -32768..32767

INTEGER _WORD [SIGNED ] $WORD--- [WORD ] -32768..32767

LONGWORD [SIGNED ] INTEGER

INTEGER _LONG [SIGNED ] INTEGER

INTEGER [SIGNED ] INTEGER

INTEGER _HW [SIGNED ] $QUAD--- [QUAD,UNSAFE ]RECORD L0: UNSIGNED; L1: INTEGER; END for /ALPHA

INTEGER for /VAX

HARDWARE _INTEGER [SIGNED ] $QUAD for /ALPHA

$QUAD for /ALPHA, INTEGER for /VAX

QUADWORD [SIGNED ] $QUAD

INTEGER _QUADWORD [SIGNED ] $QUAD

OCTAWORD [SIGNED ] $OCTA--- [OCTA,UNSAFE ]RECORD L0,L1,L2: UNSIGNED; L3: INTEGER; END

BYTE UNSIGNED $UBYTE--- [BYTE ] 0..255

INTEGER _BYTE UNSIGNED $UBYTE--- [BYTE ] 0..255

WORD UNSIGNED $UWORD--- [WORD ] 0..65535

INTEGER _WORD UNSIGNED $UWORD--- [WORD ] 0..65535

LONGWORD UNSIGNED UNSIGNED

INTEGER _LONG UNSIGNED UNSIGNED

INTEGER UNSIGNED UNSIGNED

INTEGER _HW UNSIGNED $UQUAD--- [QUAD,UNSAFE ]RECORD L0,L1: UNSIGNED; END for /ALPHA

INTEGER for /VAX

HARDWARE _INTEGER UNSIGNED $UQUAD for /ALPHA

INTEGER for /VAX

QUADWORD UNSIGNED $UQUAD

INTEGER _QUADWORD UNSIGNED $UQUAD

OCTAWORD UNSIGNED $UOCTA--- [OCTA,UNSAFE ]RECORD L0,L1,L2,L3: UNSIGNED; END

F_FLOATING SINGLE

D _FLOATING DOUBLE (D _FLOAT $ $TYPE if the logical name SDLPASCAL $FLAG is defined)

G _FLOATING DOUBLE (G _FLOAT $ $TYPE if the logical name SDLPASCAL $FLAG is defined)

H_FLOATING QUADRUPLE

F_FLOATING COMPLEX $UQAD

D_FLOATING COMPLEX $UOCTA

G_FLOATING COMPLEX $UOCTA

H_FLOATING COMPLEX $UOCTAQUAD --[OCTA(2),UNSAFE]RECORD L0,L1,L3,L4,L5,L6,L7:UNSIGNED; END;

DECIMAL PRECISION (p,q) PACKED ARRAY [1..p+2-mod(p,2)] OF $PACKED_DEC

$PACKED_DEC---[BIT(4),UNSAFE] 0..15

BITFIELD LENGTH n $BIT1---[BIT(1), UNSAFE] BOOLEAN

$BIT n---[BIT( n),UNSAFE] 0..2**n-1

MASK CONST prefixM_name = mask-value;

SIGNED n/a

CHARACTER CHAR

LENGTH n PACKED ARRAY [1..n] OF CHAR

LENGTH * PACKED ARRAY [$l..$u] OF CHAR

or VARYING [$m] OF CHAR (if VARYING is also specified)

VARYING VARYING [n] OF CHAR

or VARYING [$m] OF CHAR (if LENGTH * is also specified)

ADDRESS (object-type) ^object-type

If object type is not supplied, generates $DEFPTR, which is defined as ^ $DEFTYP; $DEFTYP is defined as [UNSAFE ] INTEGER

POINTER (object-type) ^object-type

If object type is not supplied, generates UNSIGNED

POINTER _LONG (object-type) ^object-type

If object type is not supplied, generates UNSIGNED

POINTER _HW (object-type) $QUAD for /ALPHA

INTEGER for /VAX

HARDWARE _ADDRESS (object-type) $QUAD for /ALPHA

INTEGER for /VAX

POINTER _QUAD (object-type) $QUAD

BOOLEAN BOOLEAN

user-type-name user-type-name

Default storage class TYPE

COMMON storage class [COMMON]

GLOBAL storage class [EXTERNAL]

with /GLOBALDEF [GLOBAL]

BASED pointer-name TYPE pointer-name = structure-name

TYPEDEF n/a

name DIMENSION [lbound:]hbound ARRAY [lbound..hbound] OF data type; if lbound is not supplied, it defaults to 1

ORIGIN member-name n/a

HP SDL Declaration	HP Pascal Output
MODULE name IDENT string	(* MODULE name IDENT string *)
	Note that when /MODULE is used, a HP Pascal MODULE statement of the form MODULE name; is generated.
/* comment	(* comment *)
CONSTANT x
EQUALS n;	CONST x = n;
EQUALS STRING "s";	CONST x = 's';
ENTRY	[ASYNCHRONOUS] FUNCTION
	[ASYNCHRONOUS] PROCEDURE
PARAMETER (type,...)	(formal param_list)
ANY	%REF param-name: [UNSAFE] ARRAY [$l1..$u1:INTEGER] OF $UBYTE
DESCRIPTOR	[CLASS_S] for scalars;
	[CLASS_S] for CHARACTER LENGTH 1;
	[CLASS_A] for nonscalars;
	%DESCR for fixed-length VARYING;
RTL_STR_DESC	PACKED ARRAY [$l1..$u1:INTEGER] OF CHAR;
IN	Default semantics (unless overridden by OUT)
OUT (or IN OUT)	VAR, except for CHARACTER LENGTH * and ANY (which generate %REF)
NAMED param-name	Parameter name. If none is given, names will be generated of the form $P1,...$Pn.
VALUE	%IMMED
REFERENCE	%REF for CHARACTER LENGTH * and ANY; VAR for all others if mode OUT or IN OUT; otherwise (IN only) default mechanism
DEFAULT n	:= %IMMED value
LIST	If OPTIONAL is not specified, generates one required parameter followed by a parameter with the [LIST] attribute; if OPTIONAL is specified, only the parameter with [LIST] is generated.
OPTIONAL	:=%IMMED 0
TYPENAME type-name	n/a
RETURNS return-data-type	FUNCTION name : data-type;
NAMED param-name	n/a
VARIABLE	n/a
ALIAS internal-name	Results in [EXTERNAL (entry-name)] and internal-name being used as entry-name
LINKAGE	n/a
TYPENAME type-name	n/a
STRUCTURE	RECORD
UNION	RECORD CASE INTEGER OF
	0: ...
	.
	.
	n: ...
BYTE [SIGNED ]	$BYTE--- [BYTE ] -128..127
INTEGER _BYTE [SIGNED ]	$BYTE--- [BYTE ] -128..127
WORD [SIGNED ]	$WORD--- [WORD ] -32768..32767
INTEGER _WORD [SIGNED ]	$WORD--- [WORD ] -32768..32767
LONGWORD [SIGNED ]	INTEGER
INTEGER _LONG [SIGNED ]	INTEGER
INTEGER [SIGNED ]	INTEGER
INTEGER _HW [SIGNED ]	$QUAD--- [QUAD,UNSAFE ]RECORD L0: UNSIGNED; L1: INTEGER; END for /ALPHA
	INTEGER for /VAX
HARDWARE _INTEGER [SIGNED ]	$QUAD for /ALPHA
	$QUAD for /ALPHA, INTEGER for /VAX
QUADWORD [SIGNED ]	$QUAD
INTEGER _QUADWORD [SIGNED ]	$QUAD
OCTAWORD [SIGNED ]	$OCTA--- [OCTA,UNSAFE ]RECORD L0,L1,L2: UNSIGNED; L3: INTEGER; END
BYTE UNSIGNED	$UBYTE--- [BYTE ] 0..255
INTEGER _BYTE UNSIGNED	$UBYTE--- [BYTE ] 0..255
WORD UNSIGNED	$UWORD--- [WORD ] 0..65535
INTEGER _WORD UNSIGNED	$UWORD--- [WORD ] 0..65535
LONGWORD UNSIGNED	UNSIGNED
INTEGER _LONG UNSIGNED	UNSIGNED
INTEGER UNSIGNED	UNSIGNED
INTEGER _HW UNSIGNED	$UQUAD--- [QUAD,UNSAFE ]RECORD L0,L1: UNSIGNED; END for /ALPHA
	INTEGER for /VAX
HARDWARE _INTEGER UNSIGNED	$UQUAD for /ALPHA
	INTEGER for /VAX
QUADWORD UNSIGNED	$UQUAD
INTEGER _QUADWORD UNSIGNED	$UQUAD
OCTAWORD UNSIGNED	$UOCTA--- [OCTA,UNSAFE ]RECORD L0,L1,L2,L3: UNSIGNED; END
F_FLOATING	SINGLE
D _FLOATING	DOUBLE (D _FLOAT $ $TYPE if the logical name SDLPASCAL $FLAG is defined)
G _FLOATING	DOUBLE (G _FLOAT $ $TYPE if the logical name SDLPASCAL $FLAG is defined)
H_FLOATING	QUADRUPLE
F_FLOATING COMPLEX	$UQAD
D_FLOATING COMPLEX	$UOCTA
G_FLOATING COMPLEX	$UOCTA
H_FLOATING COMPLEX	$UOCTAQUAD --[OCTA(2),UNSAFE]RECORD L0,L1,L3,L4,L5,L6,L7:UNSIGNED; END;
DECIMAL PRECISION (p,q)	PACKED ARRAY [1..p+2-mod(p,2)] OF $PACKED_DEC
	$PACKED_DEC---[BIT(4),UNSAFE] 0..15
BITFIELD LENGTH n	$BIT1---[BIT(1), UNSAFE] BOOLEAN
	$BIT n---[BIT( n),UNSAFE] 0..2**n-1
MASK	CONST prefixM_name = mask-value;
SIGNED	n/a
CHARACTER	CHAR
LENGTH n	PACKED ARRAY [1..n] OF CHAR
LENGTH *	PACKED ARRAY [$l..$u] OF CHAR
	or VARYING [$m] OF CHAR (if VARYING is also specified)
VARYING	VARYING [n] OF CHAR
	or VARYING [$m] OF CHAR (if LENGTH * is also specified)
ADDRESS (object-type)	^object-type
	If object type is not supplied, generates $DEFPTR, which is defined as ^ $DEFTYP; $DEFTYP is defined as [UNSAFE ] INTEGER
POINTER (object-type)	^object-type
	If object type is not supplied, generates UNSIGNED
POINTER _LONG (object-type)	^object-type
	If object type is not supplied, generates UNSIGNED
POINTER _HW (object-type)	$QUAD for /ALPHA
	INTEGER for /VAX
HARDWARE _ADDRESS (object-type)	$QUAD for /ALPHA
	INTEGER for /VAX
POINTER _QUAD (object-type)	$QUAD
BOOLEAN	BOOLEAN
user-type-name	user-type-name
Default storage class	TYPE
COMMON storage class	[COMMON]
GLOBAL storage class	[EXTERNAL]
with /GLOBALDEF	[GLOBAL]
BASED pointer-name	TYPE pointer-name = structure-name
TYPEDEF	n/a
name DIMENSION [lbound:]hbound	ARRAY [lbound..hbound] OF data type; if lbound is not supplied, it defaults to 1
ORIGIN member-name	n/a

Notes

When the /MODULE (default) qualifier is used, HP SDL generates the HP Pascal MODULE statement followed by a block of data type definitions. Both of these items are omitted when /NOMODULE is specified. This behavior facilitates combining multiple HP SDL-generated HP Pascal output files into a single module.
Where type names are required (for example, in parameter lists, function return types, and pointer data types), they will be generated in a TYPE block at the beginning of the module. Names have the form module-name$$TYPn, where module-name is truncated to 20 characters if necessary, and n is an integer beginning at 1 and incremented by 1 for each type generated in a module.
Bitfields cannot be more than 32 bits in length, so type names giving the appropriate subranges will be generated for each possible bitfield size. Bitfields of length 1 are a special case.
The mask-value generated by HP SDL for the MASK option of the BITFIELD data type is an integer.
HP SDL generates only single-level records for HP Pascal. Thus, you can avoid writing many long intermediate field names in the HP Pascal source program. If the outer level is a structure, a PACKED RECORD is typically declared. If the outer level is a union, a PACKED RECORD CASE INTEGER is declared.
In the case of multiple levels of structures or unions in HP SDL, the entire aggregate is transformed into a PACKED RECORD CASE INTEGER. The intermediate field-names are themselves declared as BYTE_DATA fields. This translation scheme may result in several fields in the record having the same name.

Contents

Index