ejparse.c

RTEMS (Real-Time Executive for Multiprocessor Systems) is a free open source real-time operating sys

		}
	}

	if (numeric) {
		l = gatoi(lhs);
		r = gatoi(rhs);
		switch (rel) {
		case EXPR_PLUS:
			lval = l + r;
			break;
		case EXPR_INC:
			lval = l + 1;
			break;
		case EXPR_MINUS:
			lval = l - r;
			break;
		case EXPR_DEC:
			lval = l - 1;
			break;
		case EXPR_MUL:
			lval = l * r;
			break;
		case EXPR_DIV:
			if (r != 0) {
				lval = l / r;
			} else {
				lval = 0;
			}
			break;
		case EXPR_MOD:
			if (r != 0) {
				lval = l % r;
			} else {
				lval = 0;
			}
			break;
		case EXPR_LSHIFT:
			lval = l << r;
			break;
		case EXPR_RSHIFT:
			lval = l >> r;
			break;
		case EXPR_EQ:
			lval = l == r;
			break;
		case EXPR_NOTEQ:
			lval = l != r;
			break;
		case EXPR_LESS:
			lval = (l < r) ? 1 : 0;
			break;
		case EXPR_LESSEQ:
			lval = (l <= r) ? 1 : 0;
			break;
		case EXPR_GREATER:
			lval = (l > r) ? 1 : 0;
			break;
		case EXPR_GREATEREQ:
			lval = (l >= r) ? 1 : 0;
			break;
		case EXPR_BOOL_COMP:
			lval = (r == 0) ? 1 : 0;
			break;
		default:
			ejError(ep, T("Bad operator %d"), rel);
			return -1;
		}

	} else {
		switch (rel) {
		case EXPR_PLUS:
			clearString(&ep->result);
			appendString(&ep->result, lhs);
			appendString(&ep->result, rhs);
			return 0;
		case EXPR_LESS:
			lval = gstrcmp(lhs, rhs) < 0;
			break;
		case EXPR_LESSEQ:
			lval = gstrcmp(lhs, rhs) <= 0;
			break;
		case EXPR_GREATER:
			lval = gstrcmp(lhs, rhs) > 0;
			break;
		case EXPR_GREATEREQ:
			lval = gstrcmp(lhs, rhs) >= 0;
			break;
		case EXPR_EQ:
			lval = gstrcmp(lhs, rhs) == 0;
			break;
		case EXPR_NOTEQ:
			lval = gstrcmp(lhs, rhs) != 0;
			break;
		case EXPR_INC:
		case EXPR_DEC:
		case EXPR_MINUS:
		case EXPR_DIV:
		case EXPR_MOD:
		case EXPR_LSHIFT:
		case EXPR_RSHIFT:
		default:
			ejError(ep, T("Bad operator"));
			return -1;
		}
	}

	stritoa(lval, buf, sizeof(buf));
	setString(B_L, &ep->result, buf);
	return 0;
}

/******************************************************************************/
/*
 *	Evaluate a function
 */

static int evalFunction(ej_t *ep)
{
	sym_t	*sp;
	int		(*fn)(int eid, void *handle, int argc, char_t **argv);

	if ((sp = symLookup(ep->functions, ep->func->fname)) == NULL) {
		ejError(ep, T("Undefined procedure %s"), ep->func->fname);
		return -1;
	}

	fn = (int (*)(int, void*, int, char_t**)) sp->content.value.integer;
	if (fn == NULL) {
		ejError(ep, T("Undefined procedure %s"), ep->func->fname);
		return -1;
	}

	return (*fn)(ep->eid, (void*) ep->userHandle, ep->func->nArgs,
		ep->func->args);
}

/******************************************************************************/
/*
 *	Output a parse ej_error message
 */

void ejError(ej_t* ep, char_t* fmt, ...)
{
	va_list		args;
	ejinput_t	*ip;
	char_t		*errbuf, *msgbuf;

	a_assert(ep);
	a_assert(fmt);
	ip = ep->input;

	va_start(args, fmt);
	msgbuf = NULL;
	fmtValloc(&msgbuf, E_MAX_ERROR, fmt, args);
	va_end(args);

	if (ep && ip) {
		fmtAlloc(&errbuf, E_MAX_ERROR, T("%s\n At line %d, line => \n\n%s\n"),
			msgbuf, ip->lineNumber, ip->line);
		bfreeSafe(B_L, ep->error);
		ep->error = errbuf;
	}
	bfreeSafe(B_L, msgbuf);
}

/******************************************************************************/
/*
 *	Clear a string value
 */

static void clearString(char_t **ptr)
{
	a_assert(ptr);

	if (*ptr) {
		bfree(B_L, *ptr);
	}
	*ptr = NULL;
}

/******************************************************************************/
/*
 *	Set a string value
 */

static void setString(B_ARGS_DEC, char_t **ptr, char_t *s)
{
	a_assert(ptr);

	if (*ptr) {
		bfree(B_ARGS, *ptr);
	}
	*ptr = bstrdup(B_ARGS, s);
}

/******************************************************************************/
/*
 *	Append to the pointer value
 */

static void appendString(char_t **ptr, char_t *s)
{
	int	len, oldlen;

	a_assert(ptr);

	if (*ptr) {
		len = gstrlen(s);
		oldlen = gstrlen(*ptr);
		*ptr = brealloc(B_L, *ptr, (len + oldlen + 1) * sizeof(char_t));
		gstrcpy(&(*ptr)[oldlen], s);
	} else {
		*ptr = bstrdup(B_L, s);
	}
}

/******************************************************************************/
/*
 *	Define a function
 */

int ejSetGlobalFunction(int eid, char_t *name,
	int (*fn)(int eid, void *handle, int argc, char_t **argv))
{
	ej_t	*ep;

	if ((ep = ejPtr(eid)) == NULL) {
		return -1;
	}
	return ejSetGlobalFunctionDirect(ep->functions, name, fn);
}

/******************************************************************************/
/*
 *	Define a function directly into the function symbol table.
 */

int ejSetGlobalFunctionDirect(sym_fd_t functions, char_t *name,
	int (*fn)(int eid, void *handle, int argc, char_t **argv))
{
	if (symEnter(functions, name, valueInteger((long) fn), 0) == NULL) {
		return -1;
	}
	return 0;
}

/******************************************************************************/
/*
 *	Remove ("undefine") a function
 */

int ejRemoveGlobalFunction(int eid, char_t *name)
{
	ej_t	*ep;

	if ((ep = ejPtr(eid)) == NULL) {
		return -1;
	}
	return symDelete(ep->functions, name);
}

/******************************************************************************/
/*
 *	Get a function definition
 */

void *ejGetGlobalFunction(int eid, char_t *name)
{
	ej_t	*ep;
	sym_t	*sp;
	int		(*fn)(int eid, void *handle, int argc, char_t **argv);

	if ((ep = ejPtr(eid)) == NULL) {
		return NULL;
	}

	if ((sp = symLookup(ep->functions, name)) != NULL) {
		fn = (int (*)(int, void*, int, char_t**)) sp->content.value.integer;
		return (void*) fn;
	}
	return NULL;
}

/******************************************************************************/
/*
 *	Utility routine to crack Ejscript arguments. Return the number of args
 *	seen. This routine only supports %s and %d type args.
 *
 *	Typical usage:
 *
 *		if (ejArgs(argc, argv, "%s %d", &name, &age) < 2) {
 *			error("Insufficient args\n");
 *			return -1;
 *		}
 */

int ejArgs(int argc, char_t **argv, char_t *fmt, ...)
{
	va_list	vargs;
	char_t	*cp, **sp;
	int		*ip;
	int		argn;

	va_start(vargs, fmt);

	if (argv == NULL) {
		return 0;
	}

	for (argn = 0, cp = fmt; cp && *cp && argv[argn]; ) {
		if (*cp++ != '%') {
			continue;
		}

		switch (*cp) {
		case 'd':
			ip = va_arg(vargs, int*);
			*ip = gatoi(argv[argn]);
			break;

		case 's':
			sp = va_arg(vargs, char_t**);
			*sp = argv[argn];
			break;

		default:
/*
 *			Unsupported
 */
			a_assert(0);
		}
		argn++;
	}

	va_end(vargs);
	return argn;
}

/******************************************************************************/
/*
 *	Define the user handle
 */

void ejSetUserHandle(int eid, int handle)
{
	ej_t	*ep;

	if ((ep = ejPtr(eid)) == NULL) {
		return;
	}
	ep->userHandle = handle;
}

/******************************************************************************/
/*
 *	Get the user handle
 */

int ejGetUserHandle(int eid)
{
	ej_t	*ep;

	if ((ep = ejPtr(eid)) == NULL) {
		return -1;
	}
	return ep->userHandle;
}

/******************************************************************************/
/*
 *	Get the current line number
 */

int ejGetLineNumber(int eid)
{
	ej_t	*ep;

	if ((ep = ejPtr(eid)) == NULL) {
		return -1;
	}
	return ep->input->lineNumber;
}

/******************************************************************************/
/*
 *	Set the result
 */

void ejSetResult(int eid, char_t *s)
{
	ej_t	*ep;

	if ((ep = ejPtr(eid)) == NULL) {
		return;
	}
	setString(B_L, &ep->result, s);
}

/******************************************************************************/
/*
 *	Get the result
 */

char_t *ejGetResult(int eid)
{
	ej_t	*ep;

	if ((ep = ejPtr(eid)) == NULL) {
		return NULL;
	}
	return ep->result;
}

/******************************************************************************/
/*
 *	Set a variable. Note: a variable with a value of NULL means declared but
 *	undefined. The value is defined in the top-most variable frame.
 */

void ejSetVar(int eid, char_t *var, char_t *value)
{
	ej_t	*ep;
	value_t	v;

	a_assert(var && *var);

	if ((ep = ejPtr(eid)) == NULL) {
		return;
	}

	if (value == NULL) {
		v = valueString(value, 0);
	} else {
		v = valueString(value, VALUE_ALLOCATE);
	}
	symEnter(ep->variables[ep->variableMax - 1] - EJ_OFFSET, var, v, 0);
}

/******************************************************************************/
/*
 *	Set a local variable. Note: a variable with a value of NULL means
 *	declared but undefined. The value is defined in the top-most variable frame.
 */

void ejSetLocalVar(int eid, char_t *var, char_t *value)
{
	ej_t	*ep;
	value_t	v;

	a_assert(var && *var);

	if ((ep = ejPtr(eid)) == NULL) {
		return;
	}

	if (value == NULL) {
		v = valueString(value, 0);
	} else {
		v = valueString(value, VALUE_ALLOCATE);
	}
	symEnter(ep->variables[ep->variableMax - 1] - EJ_OFFSET, var, v, 0);
}

/******************************************************************************/
/*
 *	Set a global variable. Note: a variable with a value of NULL means
 *	declared but undefined. The value is defined in the global variable frame.
 */

void ejSetGlobalVar(int eid, char_t *var, char_t *value)
{
	ej_t	*ep;
	value_t v;

	a_assert(var && *var);

	if ((ep = ejPtr(eid)) == NULL) {
		return;
	}

	if (value == NULL) {
		v = valueString(value, 0);
	} else {
		v = valueString(value, VALUE_ALLOCATE);
	}
	symEnter(ep->variables[0] - EJ_OFFSET, var, v, 0);
}

/******************************************************************************/
/*
 *	Get a variable
 */

int ejGetVar(int eid, char_t *var, char_t **value)
{
	ej_t	*ep;
	sym_t	*sp;
	int		i;

	a_assert(var && *var);
	a_assert(value);

	if ((ep = ejPtr(eid)) == NULL) {
		return -1;
	}

	i = ep->variableMax - 1;
	if ((sp = symLookup(ep->variables[i] - EJ_OFFSET, var)) == NULL) {
		i = 0;
		if ((sp = symLookup(ep->variables[0] - EJ_OFFSET, var)) == NULL) {
			return -1;
		}
	}
	a_assert(sp->content.type == string);
	*value = sp->content.value.string;
	return i;
}

/******************************************************************************/
/*
 *	Get the variable symbol table
 */

sym_fd_t ejGetVariableTable(int eid)
{
	ej_t	*ep;

	if ((ep = ejPtr(eid)) == NULL) {
		return -1;
	}
	return *ep->variables;
}

/******************************************************************************/
/*
 *	Get the functions symbol table
 */

sym_fd_t ejGetFunctionTable(int eid)
{
	ej_t	*ep;

	if ((ep = ejPtr(eid)) == NULL) {
		return -1;
	}
	return ep->functions;
}

/******************************************************************************/
/*
 *	Free an argument list
 */

static void freeFunc(ejfunc_t *func)
{
	int	i;

	for (i = func->nArgs - 1; i >= 0; i--) {
		bfree(B_L, func->args[i]);
		func->nArgs = hFree((void***) &func->args, i);
	}

	if (func->fname) {
		bfree(B_L, func->fname);
		func->fname = NULL;
	}
}

/******************************************************************************/
/*
 *	Get Ejscript pointer
 */

static ej_t *ejPtr(int eid)
{
	a_assert(0 <= eid && eid < ejMax);

	if (eid < 0 || eid >= ejMax || ejHandles[eid] == NULL) {
		ejError(NULL, T("Bad handle %d"), eid);
		return NULL;
	}
	return ejHandles[eid];
}

/******************************************************************************/
/*
 *	This function removes any new lines.  Used for else	cases, etc.
 */
static void ejRemoveNewlines(ej_t *ep, int state)
{
	int tid;

	do {
		tid = ejLexGetToken(ep, state);
	} while (tid == TOK_NEWLINE);

	ejLexPutbackToken(ep, tid, ep->token);
}

/******************************************************************************/