rgbds/src/link/symbol.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "main.h"
#include "patch.h"
#include "types.h"

#define HASHSIZE 73

struct ISymbol {
	char *pzName;
	SLONG nValue;
	SLONG nBank;		//      -1=const
	struct ISymbol *pNext;
};

struct ISymbol *tHash[HASHSIZE];

SLONG calchash(char *s)
{
	SLONG r = 0;
	while (*s)
		r += *s++;

	return (r % HASHSIZE);
}

void sym_Init(void)
{
	SLONG i;
	for (i = 0; i < HASHSIZE; i += 1)
		tHash[i] = NULL;
}

SLONG sym_GetValue(char *tzName)
{
	if (strcmp(tzName, "@") == 0) {
		return (nPC);
	} else {
		struct ISymbol **ppSym;

		ppSym = &(tHash[calchash(tzName)]);
		while (*ppSym) {
			if (strcmp(tzName, (*ppSym)->pzName)) {
				ppSym = &((*ppSym)->pNext);
			} else {
				return ((*ppSym)->nValue);
			}
		}

		sprintf(temptext, "Unknown symbol '%s'", tzName);
		fatalerror(temptext);
		return (0);
	}
}

SLONG sym_GetBank(char *tzName)
{
	struct ISymbol **ppSym;

	ppSym = &(tHash[calchash(tzName)]);
	while (*ppSym) {
		if (strcmp(tzName, (*ppSym)->pzName)) {
			ppSym = &((*ppSym)->pNext);
		} else {
			return ((*ppSym)->nBank);
		}
	}

	sprintf(temptext, "Unknown symbol '%s'");
	fatalerror(temptext);
	return (0);
}

void sym_CreateSymbol(char *tzName, SLONG nValue, SBYTE nBank)
{
	if (strcmp(tzName, "@") == 0) {
	} else {
		struct ISymbol **ppSym;

		ppSym = &(tHash[calchash(tzName)]);

		while (*ppSym) {
			if (strcmp(tzName, (*ppSym)->pzName)) {
				ppSym = &((*ppSym)->pNext);
			} else {
				if (nBank == -1)
					return;

				sprintf(temptext,
					"Symbol '%s' defined more than once\n",
					tzName);
				fatalerror(temptext);
			}
		}

		if (*ppSym = (struct ISymbol *)malloc(sizeof(struct ISymbol))) {
			if ((*ppSym)->pzName =
			    (char *)malloc(strlen(tzName) + 1)) {
				strcpy((*ppSym)->pzName, tzName);
				(*ppSym)->nValue = nValue;
				(*ppSym)->nBank = nBank;
				(*ppSym)->pNext = NULL;
			}
		}
	}
}