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Example2.LZH
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sym.c
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C/C++ Source or Header
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1990-08-30
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3KB
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160 lines
/* Copyright (c) 1988 by Sozobon, Limited. Author: Tony Andrews
*
* Permission is granted to anyone to use this software for any purpose
* on any computer system, and to redistribute it freely, with the
* following restrictions:
* 1) No charge may be made other than reasonable charges for reproduction.
* 2) Modified versions must be clearly marked as such.
* 3) The authors are not responsible for any harmful consequences
* of using this software, even if they result from defects in it.
*/
#include "top.h"
/*
* Symbol table:
*
* For each symbol, contains a pointer to the block starting at the
* given symbol, and a pointer to the next symbol in the symbol table.
*/
struct sym {
char *name;
BLOCK *bp;
struct sym *next;
};
struct sym *sfirst = NULL;
struct sym *slast = NULL;
/*
* newblock(name) - allocate a new block structure and initialize it
*/
BLOCK *
newblock(name)
register char *name;
{
register BLOCK *bp;
if ((bp = (BLOCK *) alloc(sizeof(BLOCK))) == NULL)
return NULL;
/*
* Initialize the allocated block structure.
*/
if ((bp->name = strsave(name)) == NULL) {
free(bp);
return NULL;
}
bp->flags = 0;
bp->ref = 0;
bp->bcode = 0;
bp->first = NULL;
bp->last = NULL;
bp->bcond = NULL;
bp->bfall = NULL;
bp->chain = NULL;
bp->next = NULL;
bp->rref = bp->rset = 0;
return bp;
}
/*
* mksym(name) - make a new symbol table entry
*
* mksym creates new symbol table entries, and allocates space for the
* 'block' structure that will be used for the symbol. This can happen
* when a reference to a block is detected, but before the block has
* been encountered. Since we allocate the block structure here, other
* blocks can reference it before we actually read it in.
*/
BLOCK *
mksym(name)
register char *name;
{
register struct sym *new;
if ((new = (struct sym *) alloc(sizeof(struct sym))) == NULL)
return NULL;
if ((new->bp = newblock(name)) == NULL) {
free(new);
return NULL;
}
new->name = new->bp->name;
new->next = NULL;
if (sfirst == NULL)
sfirst = slast = new;
else {
slast->next = new;
slast = new;
}
return new->bp;
}
/*
* getsym(name) - return a pointer to the block for symbol 'name'
*
* Scans the symbol table for the given symbol and returns a pointer
* to its block, when found, or NULL if not present.
*/
BLOCK *
getsym(name)
register char *name;
{
register struct sym *sp;
for (sp = sfirst; sp != NULL ;sp = sp->next) {
if (strcmp(sp->name, name) == 0)
return sp->bp;
}
return NULL;
}
/*
* freesym() - free all symbol table space
*/
void
freesym()
{
register struct sym *sp, *nexts;
register INST *ip, *nexti;
for (sp = sfirst; sp != NULL ;sp = nexts) {
nexts = sp->next;
for (ip = sp->bp->first; ip != NULL ; ip = nexti) {
nexti = ip->next;
if (ip->src.astr != NULL)
free(ip->src.astr);
if (ip->dst.astr != NULL)
free(ip->dst.astr);
free(ip);
}
free(sp->name);
free(sp->bp);
free(sp);
}
sfirst = slast = NULL;
}
#ifdef NORTHC
static char tname[32];
static int tnum = 0;
#endif
char *
mktmp()
{
#ifndef NORTHC
static char tname[32];
static int tnum = 0;
#endif
sprintf(tname, "T%d", tnum++);
return tname;
}