1/*	$NetBSD: gsp_sym.c,v 1.8 2006/08/26 18:15:37 christos Exp $	*/
2/*
3 * GSP assembler - symbol table
4 *
5 * Copyright (c) 1993 Paul Mackerras.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *      This product includes software developed by Paul Mackerras.
19 * 4. The name of the author may not be used to endorse or promote products
20 *    derived from this software without specific prior written permission
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34#include <sys/cdefs.h>
35#ifndef lint
36__RCSID("$NetBSD: gsp_sym.c,v 1.8 2006/08/26 18:15:37 christos Exp $");
37#endif
38
39#include <stdio.h>
40#include <string.h>
41#include <util.h>
42#include "gsp_ass.h"
43
44#define NHASH	64		/* must be power of 2 */
45
46symbol symbol_hash[NHASH];
47
48void define_sym(char *, unsigned, unsigned, int);
49
50symbol
51lookup(char *id, bool makeit)
52{
53	symbol ptr, p, *pp;
54	int h;
55	char *ip;
56
57	h = 0;
58	for( ip = id; *ip != 0; )
59		h = (h << 1) + *ip++;
60	h &= NHASH-1;
61	for( pp = &symbol_hash[h]; (p = *pp) != NULL; pp = &p->next )
62		if( (h = strcmp(id, p->name)) == 0 )
63			return p;
64		else if( h < 0 )
65			break;
66	if( !makeit )
67		return NULL;
68	ptr = emalloc(sizeof(struct symbol) + strlen(id));
69	ptr->ndefn = 0;
70	ptr->flags = 0;
71	ptr->value = 0;
72	ptr->lineno = NOT_YET;
73	strcpy(ptr->name, id);
74	*pp = ptr;
75	ptr->next = p;
76	ptr->nlab = NULL;
77	return ptr;
78}
79
80void
81define_sym(char *id, unsigned val, unsigned lno, int flags)
82{
83	symbol ptr;
84
85	ptr = lookup(id, TRUE);
86	if( (ptr->flags & SET_LABEL) == 0 ){
87		if( ptr->ndefn >= 2 ){
88			perr("Multiply defined label %s", id);
89			if( (flags & SET_LABEL) != 0 )
90				return;
91		} else if( pass2 && ptr->value != val )
92			perr("Phase error on label %s (%#x -> %#x)",
93				id, ptr->value, val);
94	}
95	ptr->flags = flags;
96	ptr->ndefn += 1;
97	ptr->value = val;
98	ptr->lineno = lno;
99}
100
101void
102set_label(char *id)
103{
104	if( id != NULL ){
105		define_sym(id, pc, lineno, DEFINED);
106		if( pass2 )
107			do_list_pc();
108	}
109}
110
111void
112do_asg(char *name, expr value, int flags)
113{
114	int32_t val;
115	unsigned lno;
116
117	if( eval_expr(value, &val, &lno) )
118		flags |= DEFINED;
119	if( lno < lineno )
120		lno = lineno;
121	define_sym(name, val, lno, flags);
122	if( pass2 )
123		do_show_val(val);
124}
125
126void
127set_numeric_label(int lnum)
128{
129	symbol bp, fp;
130	struct numlab *nl;
131	char id[32];
132
133	/* define the backward reference symbol */
134	sprintf(id, "%dB", lnum);
135	bp = lookup(id, TRUE);
136	bp->flags = NUMERIC_LABEL | DEFINED;
137	bp->value = pc;
138	bp->lineno = lineno;
139
140	/* look up the forward reference symbol */
141	id[strlen(id) - 1] = 'F';
142	fp = lookup(id, TRUE);
143
144	if( !pass2 ){
145		/* Record a new numeric label and link it into the
146		   chain.  fp->nlab points to the head of the chain,
147		   bp->nlab points to the tail.  */
148		new(nl);
149		nl->value = pc;
150		nl->lineno = lineno;
151		nl->next = NULL;
152		if( bp->nlab == NULL )
153			fp->nlab = nl;
154		else
155			bp->nlab->next = nl;
156		bp->nlab = nl;
157		fp->flags = NUMERIC_LABEL;
158	} else {
159		/* Advance to the next numeric label entry in the chain
160		   and update the value of the forward reference symbol. */
161		if( pc != fp->value )
162			perr("Phase error on numeric label %d (%#x -> %#x)",
163				lnum, fp->value, pc);
164		nl = fp->nlab;
165		nl = nl->next;
166		if( nl == NULL ){
167			/* no more labels of this number */
168			/* forward references are now undefined */
169			fp->flags &= ~DEFINED;
170			fp->lineno = NOT_YET;
171			fp->value = 0;
172		} else {
173			fp->lineno = nl->lineno;
174			fp->value = nl->value;
175			fp->nlab = nl;
176		}
177		do_list_pc();
178	}
179}
180
181/* At the beginning of pass 2, reset all of the numeric labels.
182   Backward references become undefined, forward references are defined
183   by the first instance of the label. */
184void
185reset_numeric_labels()
186{
187	symbol p;
188	struct numlab *nl;
189	int h;
190
191	for( h = 0; h < NHASH; ++h ) {
192		for( p = symbol_hash[h]; p != NULL; p = p->next ) {
193			if( (p->flags & NUMERIC_LABEL) != 0 ) {
194				if( (p->flags & DEFINED) != 0 ) {
195					/* a backward reference */
196					p->flags &= ~DEFINED;
197				} else {
198					/* a forward reference */
199					p->flags |= DEFINED;
200					nl = p->nlab;
201					p->value = nl->value;
202					p->lineno = nl->lineno;
203				}
204			}
205		}
206	}
207}
208