xref: /original-bsd/usr.bin/pascal/pdx/tree.h (revision 42f60e33)
1 /*-
2  * Copyright (c) 1980, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  *
7  *	@(#)tree.h	8.1 (Berkeley) 06/06/93
8  */
9 
10 /*
11  * This file contains the declarations of the variables and routines
12  * within the "tree" subdirectory that are accessible from outside.
13  */
14 
15 #include "tree/opinfo.h"
16 
17 /*
18  * Evaluation stack manipulation macros.  These are publically
19  * available because "eval" leaves it's result on the stack.
20  *
21  * These macros allow one to operate on stacks of arbitrary types
22  * (including a stack of different typed objects).
23  *
24  * Sadly, underflow and overflow are not checked for.
25  */
26 
27 typedef char STACK;
28 
29 #define WMASK			(sizeof(int) - 1)
30 
31 #ifdef tahoe
32 #define push(type, value)	((*(type *)sp) = value, sp += (sizeof(type) + WMASK) & ~WMASK, value)
33 #define	pop(type)		(sp -= (sizeof(type) + WMASK) & ~WMASK, (*((type *) sp)))
34 #else
35 #define push(type, value)	((type *) (sp += sizeof(type)))[-1] = (value)
36 #define pop(type)		(*((type *) (sp -= sizeof(type))))
37 #endif
38 #define alignstack()		sp = (char *) (( ((int) sp) + WMASK)&~WMASK)
39 #define downalignstack()	sp = (char *) (( ((int) sp))&~WMASK)
40 
41 STACK stack[];
42 STACK *sp;
43 
44 NODE *build();		/* create a node in the parse tree */
45 int prtree();		/* print a tree in source form */
46 int eval();		/* evaluate a tree, leaving value on stack */
47 long popsmall();	/* pop a small item from the stack given its type */
48 int tfree();		/* release storage for a tree */
49 BOOLEAN tr_equal();	/* test if two trees are structurally equivalent */
50 BOOLEAN cond();		/* evaluate a node for a conditional */
51 ADDRESS lval();		/* return the object address of a node */
52 BOOLEAN isredirected();	/* TRUE if output is being redirected */
53