/*
* Skip over an identifier.
*/
static const char *
skipsym(const char *cp)
{
while (!endsym(*cp))
++cp;
return (cp);
}
/*
* Function for evaluating the innermost parts of expressions,
* viz. !expr (expr) number defined(symbol) symbol
* We reset the constexpr flag in the last two cases.
*/
static Linetype
eval_unary(const struct ops *ops, int *valp, const char **cpp)
{
const char *cp;
char *ep;
int sym;
bool defparen;
Linetype lt;
cp = skipcomment(*cpp);
if (*cp == '!') {
debug("eval%d !", prec(ops));
cp++;
lt = eval_unary(ops, valp, &cp);
if (lt == LT_ERROR)
return (LT_ERROR);
if (lt != LT_IF) {
*valp = !*valp;
lt = *valp ? LT_TRUE : LT_FALSE;
}
} else if (*cp == '(') {
cp++;
debug("eval%d (", prec(ops));
lt = eval_table(eval_ops, valp, &cp);
if (lt == LT_ERROR)
return (LT_ERROR);
cp = skipcomment(cp);
if (*cp++ != ')')
return (LT_ERROR);
} else if (isdigit((unsigned char)*cp)) {
debug("eval%d number", prec(ops));
*valp = strtol(cp, &ep, 0);
if (ep == cp)
return (LT_ERROR);
lt = *valp ? LT_TRUE : LT_FALSE;
cp = skipsym(cp);
} else if (strncmp(cp, "defined", 7) == 0 && endsym(cp[7])) {
cp = skipcomment(cp+7);
debug("eval%d defined", prec(ops));
if (*cp == '(') {
cp = skipcomment(cp+1);
defparen = true;
} else {
defparen = false;
}
sym = findsym(cp);
if (sym < 0) {
lt = LT_IF;
} else {
*valp = (value[sym] != NULL);
lt = *valp ? LT_TRUE : LT_FALSE;
}
cp = skipsym(cp);
cp = skipcomment(cp);
if (defparen && *cp++ != ')')
return (LT_ERROR);
constexpr = false;
} else if (!endsym(*cp)) {
/*
* Function for evaluating the innermost parts of expressions,
* viz. !expr (expr) defined(symbol) symbol number
* We reset the keepthis flag when we find a non-constant subexpression.
*/
static Linetype
eval_unary(const struct ops *ops, int *valp, const char **cpp)
{
const char *cp;
char *ep;
int sym;
cp = skipcomment(*cpp);
if (*cp == '!') {
debug("eval%d !", ops - eval_ops);
cp++;
if (eval_unary(ops, valp, &cp) == LT_IF) {
*cpp = cp;
return (LT_IF);
}
*valp = !*valp;
} else if (*cp == '(') {
cp++;
debug("eval%d (", ops - eval_ops);
if (eval_table(eval_ops, valp, &cp) == LT_IF)
return (LT_IF);
cp = skipcomment(cp);
if (*cp++ != ')')
return (LT_IF);
} else if (isdigit((unsigned char)*cp)) {
debug("eval%d number", ops - eval_ops);
*valp = strtol(cp, &ep, 0);
cp = skipsym(cp);
} else if (strncmp(cp, "defined", 7) == 0 && endsym(cp[7])) {
cp = skipcomment(cp+7);
debug("eval%d defined", ops - eval_ops);
if (*cp++ != '(')
return (LT_IF);
cp = skipcomment(cp);
sym = findsym(cp);
cp = skipsym(cp);
cp = skipcomment(cp);
if (*cp++ != ')')
return (LT_IF);
if (sym >= 0)
*valp = (value[sym] != NULL);
else {
*cpp = cp;
return (LT_IF);
}
keepthis = false;
} else if (!endsym(*cp)) {
debug("eval%d symbol", ops - eval_ops);
sym = findsym(cp);
if (sym < 0)
return (LT_IF);
if (value[sym] == NULL)
*valp = 0;
else {
*valp = strtol(value[sym], &ep, 0);
if (*ep != '\0' || ep == value[sym])
return (LT_IF);
}
cp = skipsym(cp);
keepthis = false;
} else {
debug("eval%d bad expr", ops - eval_ops);
return (LT_IF);
}
*cpp = cp;
debug("eval%d = %d", ops - eval_ops, *valp);
return (*valp ? LT_TRUE : LT_FALSE);
}
