#pragma once
#ifndef LWIP_PORT_STDLIB_H
#define LWIP_PORT_STDLIB_H

/*
 * Minimal freestanding stdlib shim for lwIP.
 *
 * lwIP 2.2.1 includes <stdlib.h> in a couple of files only for atoi(). If MSVC
 * finds the UCRT header, it drags errno.h into the kernel build and then lwIP's
 * own errno values collide with UCRT's. Put this header first in lwIP's include
 * path so those sources stay freestanding.
 */
static __inline int atoi(const char* s) {
    int sign = 1;
    int value = 0;

    if (!s)
        return 0;

    while (*s == ' ' || *s == '\t' || *s == '\n' || *s == '\r' || *s == '\v' || *s == '\f')
        ++s;

    if (*s == '-') {
        sign = -1;
        ++s;
    } else if (*s == '+') {
        ++s;
    }

    while (*s >= '0' && *s <= '9') {
        value = value * 10 + (*s - '0');
        ++s;
    }

    return sign * value;
}

#endif /* LWIP_PORT_STDLIB_H */