[lwip-devel] lowpan6_ble.c build failure if LWIP_RFC7668_NUM_CONTEXTS==0

[Axel Lin]

cc -g -DLWIP_DEBUG -Wall -pedantic -Wparentheses -Wsequence-point
-Wswitch-default -Wextra -Wundef -Wshadow -Wpointer-arith -Wcast-qual
-Wc++-compat -Wwrite-strings -Wold-style-definition -Wcast-align
-Wmissing-prototypes -Wredundant-decls -Wnested-externs
-Wunreachable-code -Wuninitialized -Wmissing-prototypes
-Wredundant-decls -Waggregate-return -Wlogical-not-parentheses
-Wlogical-op -Wc90-c99-compat -Wtrampolines -I. -I../../..
-I../../../../lwip/src/include -I../../../ports/unix/port/include
-I../../../../mbedtls/include -Wno-redundant-decls
-DLWIP_HAVE_MBEDTLS=1 -c ../../../../lwip/src/netif/lowpan6_ble.c
../../../../lwip/src/netif/lowpan6_ble.c: In function ‘rfc7668_context_lookup’:
../../../../lwip/src/netif/lowpan6_ble.c:144:42: warning: unused
parameter ‘ip6addr’ [-Wunused-parameter]
 rfc7668_context_lookup(const ip6_addr_t *ip6addr)
                                          ^~~~~~~
../../../../lwip/src/netif/lowpan6_ble.c: In function ‘rfc7668_set_context’:
../../../../lwip/src/netif/lowpan6_ble.c:464:26: warning: unused
parameter ‘idx’ [-Wunused-parameter]
 rfc7668_set_context(u8_t idx, const ip6_addr_t * context)
                          ^~~
../../../../lwip/src/netif/lowpan6_ble.c:464:50: warning: unused
parameter ‘context’ [-Wunused-parameter]
 rfc7668_set_context(u8_t idx, const ip6_addr_t * context)
                                                  ^~~~~~~
../../../../lwip/src/netif/lowpan6_ble.c: In function ‘rfc7668_decompress’:
../../../../lwip/src/netif/lowpan6_ble.c:666:13: warning: comparison
is always true due to limited range of data type [-Wtype-limits]
       if (j >= LWIP_RFC7668_NUM_CONTEXTS) {
             ^~
../../../../lwip/src/netif/lowpan6_ble.c:673:29: error:
‘rfc7668_context’ undeclared (first use in this function); did you
mean ‘rfc7668_set_context’?
       ip6hdr->src.addr[0] = rfc7668_context[j].addr[0];
                             ^~~~~~~~~~~~~~~
                             rfc7668_set_context
../../../../lwip/src/netif/lowpan6_ble.c:673:29: note: each undeclared
identifier is reported only once for each function it appears in
../../../../lwip/src/netif/lowpan6_ble.c:753:13: warning: comparison
is always true due to limited range of data type [-Wtype-limits]
       if (j >= LWIP_RFC7668_NUM_CONTEXTS) {
             ^~
At top level:
../../../../lwip/src/netif/lowpan6_ble.c:144:1: warning:
‘rfc7668_context_lookup’ defined but not used [-Wunused-function]
 rfc7668_context_lookup(const ip6_addr_t *ip6addr)
 ^~~~~~~~~~~~~~~~~~~~~~
/home/axel/git/lwip/lwip-contrib/ports/unix/../Common.allports.mk:91:
recipe for target 'lowpan6_ble.o' failed
make: *** [lowpan6_ble.o] Error 1