.pg
.x d__descr
.x Obsolete Macros > d__descr
.lt
------------------------------------------------------------------------
D_DESCR	.BLKx length [address] [allot]
------------------------------------------------------------------------
.el
.b 3
This macro will allocate the appropriate dynamic descriptor structure for the
storage type specified: 
.b
One the following directives must be used in place of .BLK^&x\&.
.b
.lt
	.BLKA	addresses (longwords)
	.BLKB	bytes
	.BLKD	double-precision floating-point (quadwords)
	.BLKF	single-precision floaging-point (longwords)
	.BLKG	G_floating (quadwords)
	.BLKH	H_floating (octawords)
	.BLKL	longwords
	.BLKO	octawords
	.BLKQ	quadwords
	.BLKW	words
.el
.b
If ^&address\& is specified as the asterisk character (i.e. _*), the D__DESCR
macro will also generate the appropriate block storage allocation directive. 
.b
If ^&address\& is not specified, no storage allocation directive is generated;
you must then follow the D__DESCR macro with the appropriate storage allocation
directive. 
.b
If ^&address\& is specified and allot is specified as the asterisk character,
the D__DESCR macro will generate the appropriate block storage allocation
directive and assign it to the label address. 
.b
For example:
.b
.lt
	var
		buffer_descr:	d_descr .blkb 512 buffer *
.el
.b
will generate the following code:
.b
.lt
	buffer_descr:
		.word	512
		.byte	dsc$k_dtype_b
		.byte	dsc$k_class_d
		.address	buffer
	buffer:
		.blkb	512
.el
.b
See also DESCR, STDESCR, and D__STDESCR.