pTAL Reference Manual (G06.24+, H06.09+, J06.03+)

VOLATILE
specifies that the value of this variable must be maintained in memory, not in a register. Each
reference to a VOLATILE data item causes the data item to be read or written to memory even
when code is optimized. Based on the order of reads and writes in the source code, VOLATILE
also causes that precise order of memory references to be preserved, again, when code is
optimized.
STRING
is the STRING attribute.
INT
is the INT attribute, as INT, INT(32), or FIXED.
., .EXT, .EXT32, .EXT64, .SG, .SGX
are indirection symbols (see Table 14 (page 41)).
identifier
is the identifier of the pointer.
referral
is the identifier of a previously-declared structure, structure template, or structure pointer.
Specify referral only for pointers to structures.
initialization
is an expression representing a memory address. For more information about operations on
addresses, see Chapter 5 (page 69).
Initializing Structure Pointers
The addressing mode and data type of the simple pointer determines the kind of address the pointer
can contain.
For information about data types and addresses, see Table 49 (page 165) and Table 50 (page 166).
Furthermore, the kind of expression you can specify for the address depends on the level at which
you declare the pointer:
• Use a constant expression at the global level. See also Initializing Simple Pointers (page 172).
• At the local or sublocal level, you can use any arithmetic expression.
If the expression is the address of a structure with an index, the structure pointer points to a particular
occurrence of the structure. If the expression is the address of an array, with or without an index,
you impose the structure on top of the array.
174 Pointers