contikimac: remove set-but-unused variable
contikimac: remove set-but-unused variable
core/net/mac: remove unused NETSTACK_RADIO return code

Without investigating, this code is probably wrong as any error returned by
the NETSTACK_RADIO routine will be lost.
core/net/resolv.c: work around declared/set-but-unused variables

The set-by-unused in mdns_write_announce_records for IPv6 ignores the
structure and writes data as bytes with content layout implicit and manual
endianness conversion.

The declared-but-unused is probably just failure to cleanup after a
refactor.
core/net/resolv.c: fix bitfield declaration

Use unsigned single-bit fields to avoid:

  resolv.c:1288:7: error: overflow in implicit constant conversion [-Werror=overflow]
core/net/uip.h: include header required for memcmp

Macros in this file reference this function, but the source files that
invoke them do not necessarily include the corresponding declaration.
rpl-dag: bypass set-but-unused warning for local variable

Value is referenced only in conditional debug code, but the declaration and
assignment are not conditional.
rpl-ext-header: remove unused variable

Unnecessary to remember previous length when entire header is removed.
rpl-icmp6: bypass set-but-unused warnings

These seem to be assigned primarily for documentation purposes (to record
what is in the buffer even though it is not used).  For dao_ack_input it
appears this function is not implemented, and fields are only referenced
when debugging is enabled.
ctk: remove set-but-unused warnings

Only declare and set variable when it is required.
native/contiki-main.c: node_id only required when not UIP_CONF_IPV6

Eliminate unnecessary declaration when it will never be referenced.
uip-icmp6.c: make declaration conditional on use

File-scope temporary address is only used when UIP_CONF_IPV6 is set.

Also remove gratuitous documentation comment on internal variable.
uip-icmp6.c: avoid declaring zero-length array

Inhibit declaration of and references to uip_ds6_netif_t::aaddr_list when
that field has no data.
core/net/resolv.c: include header required for strncasecmp

strncasecmp is a non-standard unix-style function.  glibc puts it in
<strings.h>, but some toolchains don't have that header and add the
declaration to <string.h> instead.  Just declare it normally.
Makefile.native: option to exclude -std=c99 -pedantic when WERROR=1

Native mtarch.c includes <ucontext.h> to get access to task data.  That
header will not define the stack_t type when forced to conform to the C
standard since it intrudes on the language-defined namespace.  Use WERROR=1
WERROR_C99=0 to allow checked builds of native applications that require
mtarch.c.
rime/collect.c: fix set-but-unused variable

Use dependent on debug infrastructure.
rime/collect-neighbor.c: remove set-but-unused
apps/powertrace: fix set-but-unused variable

All fields are extracted but only a few used.  Add void references in lieu
of removing the unused values, to simplify temporary adaptation of the
output.
apps/shell: work around set-but-unused variable

Saved but unchecked return value is probably a bug.
apps/shell: work around set-but-unused variable

Assumes this static variable is present for inspection under a debugger.
Make the declaration volatile to ensure the value is available; still also
need the bogus reference to avoid the warning that it is unused.