This fixes the following warnings:
test_tcp.c:266:5: error: code will never be executed [-Werror,-Wunreachable-code]
pbuf_free(p);
^~~~~~~~~
- The check API 'fail' aborts the test, thus pbuf_free(p) will never be executed
pbuf.c:783:111: error: format specifies type 'unsigned short' but the argument has type 'u8_t' (aka 'unsigned char') [-Werror,-Wformat]
LWIP_DEBUGF( PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_free: %p has ref %"U16_F", ending here.\n", (void *)p, ref));
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
- LWIP_PBUF_REF_T is u8_t by default and doesn't match U16_F, so cast to u16_t. The cast and formatter will need to be changed
if ref is larger than 16 bits
ethernet.c:105:16: error: format specifies type 'unsigned char' but the argument has type 'unsigned int' [-Werror,-Wformat]
(unsigned)ethhdr->dest.addr[0], (unsigned)ethhdr->dest.addr[1], (unsigned)ethhdr->dest.addr[2],
~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- addr[] is type u8_t, formatter is X8_F which should be 8 bits. 'unsigned' is an int, so cast to unsighed char instead
Eliminate ETHADDR32_COPY macro - it cannot be used in ETH_PAD_SIZE case. I could have kept it by defining it to ETHADDR16_COPY in case of ETH_PAD_SIZE, but I did not consider it worth another #ifdef mess.
Let lwip use functions/macros prefixed by lwip_ internally to avoid naming clashes with external #includes.
Remove over-complicated #define handling in def.h
Make functions easier to override in cc.h. The following is sufficient now (no more LWIP_PLATFORM_BYTESWAP):
#define lwip_htons(x) <your_htons>
#define lwip_htonl(x) <your_htonl>
Change macro signature to be universal: netif, pbuf, src, dst, eth_type - whatever the user needs to decide about VLAN header.
Return value <0 means "no VLAN header", 0 <= return_value <= 0xFFFF -> value is prio_vid of header.
Clean up ethernet_output function to be more readable.
