ack/lang/m2/comp/desig.h
2006-02-04 00:57:05 +00:00

68 lines
2 KiB
C

/*
* (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
* See the copyright notice in the ACK home directory, in the file "Copyright".
*
* Author: Ceriel J.H. Jacobs
*/
/* D E S I G N A T O R D E S C R I P T I O N S */
/* $Id$ */
/* Generating code for designators is not particularly easy, especially if
you don't know wether you want the address or the value.
The next structure is used to generate code for designators.
It contains information on how to find the designator, after generation
of the code that is common to both address and value computations.
*/
struct desig {
short dsg_kind;
#define DSG_INIT 0 /* don't know anything yet */
#define DSG_LOADED 1 /* designator loaded on top of the stack */
#define DSG_PLOADED 2 /* designator accessible through pointer on
stack, possibly with an offset
*/
#define DSG_FIXED 3 /* designator directly accessible */
#define DSG_PFIXED 4 /* designator accessible through directly
accessible pointer
*/
#define DSG_INDEXED 5 /* designator accessible through array
operation. Address of array descriptor on
top of the stack, index beneath that, and
base address beneath that
*/
arith dsg_offset; /* contains an offset for PLOADED,
or for FIXED or PFIXED it contains an
offset from dsg_name, if it exists,
or from the current Local Base
*/
char *dsg_name; /* name of global variable, used for
FIXED and PFIXED
*/
struct def *dsg_def; /* def structure associated with this
designator, or 0
*/
};
typedef struct desig t_desig;
/* The next structure describes the designator in a with-statement.
We have a linked list of them, as with-statements may be nested.
*/
struct withdesig {
struct withdesig *w_next;
int w_flags; /* D_USED|D_DEFINED */
struct scope *w_scope; /* scope in which fields of this record
reside
*/
t_desig w_desig; /* a desig structure for this particular
designator
*/
};
extern struct withdesig *WithDesigs;
#define NO_LABEL ((label) 0)