I can't figure out what "enterlevel" function is doing here. I am aware that the below has implicit stack. I am also aware that "nCcalls" is the number of of nested calls.
https://www.lua.org/source/5.2/lparser.c.htmlstatic
BinOpr subexpr (
LexState *ls,
expdesc *v, int limit) {
BinOpr op;
UnOpr uop;
enterlevel(ls);
uop = getunopr(ls->t.token);
if (uop != OPR_NOUNOPR) {
int line = ls->linenumber;
luaX_next(ls);
subexpr(ls, v, UNARY_PRIORITY);
luaK_prefix(ls->fs, uop, v, line);
}
else simpleexp(ls, v);
/* expand while operators have priorities higher than `limit' */
op = getbinopr(ls->t.token);
while (op != OPR_NOBINOPR && priority[op].left > limit) {
expdesc v2;
BinOpr nextop;
int line = ls->linenumber;
luaX_next(ls);
luaK_infix(ls->fs, op, v);
/* read sub-_expression_ with higher priority */
nextop = subexpr(ls, &v2, priority[op].right);
luaK_posfix(ls->fs, op, v, &v2, line);
op = nextop;
}
leavelevel(ls);
return op; /* return first untreated operator */
}
Regards, Emeka
