dhcpcd-discuss

Hi Maddes

On 03/10/2017 22:40, M. Buecher wrote:
> I compiled the current git master on Raspbian/Debian 9.1 and got some 
> compiler warnings regarding signed/unsigned conversions.
> Just wanted to inform you, so that these can get handled during the 
> ongoing development.
> Build log from debuild is attached for your reference.

What cc version is this?

> Kind regards
> Maddes
>
>
> a) src/common.c
> common.c: In function ‘recvmsg_realloc’:
> common.c:240:9: warning: negative integer implicitly converted to 
> unsigned type [-Wsign-conversion]
>     len = roundup(len, IOVEC_BUFSIZ);

Might be fixable.

>           ^~~~~~~
>
> b) src/if-linux.c
> if-linux.c: In function ‘get_netlink’:
> if-linux.c:374:13: warning: conversion to ‘__u32 {aka unsigned int}’ 
> from ‘ssize_t {aka int}’ may change the sign of the result 
> [-Wsign-conversion]
>         nlm = NLMSG_NEXT(nlm, len))
>               ^~~~~~~~~~
> if-linux.c:374:13: warning: conversion to ‘ssize_t {aka int}’ from 
> ‘__u32 {aka unsigned int}’ may change the sign of the result 
> [-Wsign-conversion]
> if-linux.c: In function ‘add_attr_l’:
> if-linux.c:864:40: warning: conversion to ‘__u32 {aka unsigned int}’ 
> from ‘int’ may change the sign of the result [-Wsign-conversion]
>    ((struct rtattr *)(((ptrdiff_t)(nmsg))+NLMSG_ALIGN((nmsg)->nlmsg_len)))
>                                          ^
> if-linux.c:878:8: note: in expansion of macro ‘NLMSG_TAIL’
>    rta = NLMSG_TAIL(n);
>          ^~~~~~~~~~
> if-linux.c: In function ‘add_attr_32’:
> if-linux.c:864:40: warning: conversion to ‘__u32 {aka unsigned int}’ 
> from ‘int’ may change the sign of the result [-Wsign-conversion]
>    ((struct rtattr *)(((ptrdiff_t)(nmsg))+NLMSG_ALIGN((nmsg)->nlmsg_len)))
>                                          ^
> if-linux.c:900:8: note: in expansion of macro ‘NLMSG_TAIL’
>    rta = NLMSG_TAIL(n);
>          ^~~~~~~~~~
> if-linux.c: In function ‘nla_put_32’:
> if-linux.c:964:8: warning: negative integer implicitly converted to 
> unsigned type [-Wsign-conversion]
>    len = NLA_ALIGN(NLA_HDRLEN + sizeof(data));
>          ^~~~~~~~~
> if-linux.c:964:8: warning: negative integer implicitly converted to 
> unsigned type [-Wsign-conversion]
> if-linux.c:864:40: warning: conversion to ‘__u32 {aka unsigned int}’ 
> from ‘int’ may change the sign of the result [-Wsign-conversion]
>    ((struct rtattr *)(((ptrdiff_t)(nmsg))+NLMSG_ALIGN((nmsg)->nlmsg_len)))
>                                          ^
> if-linux.c:970:25: note: in expansion of macro ‘NLMSG_TAIL’
>    nla = (struct nlattr *)NLMSG_TAIL(n);
>                           ^~~~~~~~~~
> if-linux.c:973:9: warning: negative integer implicitly converted to 
> unsigned type [-Wsign-conversion]
>    memcpy(NLA_DATA(nla), &data, sizeof(data));
>           ^~~~~~~~
> if-linux.c: In function ‘nla_put_string’:
> if-linux.c:987:8: warning: negative integer implicitly converted to 
> unsigned type [-Wsign-conversion]
>    len = NLA_ALIGN(NLA_HDRLEN + sl);
>          ^~~~~~~~~
> if-linux.c:987:8: warning: negative integer implicitly converted to 
> unsigned type [-Wsign-conversion]
> if-linux.c:864:40: warning: conversion to ‘__u32 {aka unsigned int}’ 
> from ‘int’ may change the sign of the result [-Wsign-conversion]
>    ((struct rtattr *)(((ptrdiff_t)(nmsg))+NLMSG_ALIGN((nmsg)->nlmsg_len)))
>                                          ^
> if-linux.c:993:25: note: in expansion of macro ‘NLMSG_TAIL’
>    nla = (struct nlattr *)NLMSG_TAIL(n);
>                           ^~~~~~~~~~
> if-linux.c:996:9: warning: negative integer implicitly converted to 
> unsigned type [-Wsign-conversion]
>    memcpy(NLA_DATA(nla), data, sl);
>           ^~~~~~~~
> if-linux.c: In function ‘_gnl_getfamily’:
> if-linux.c:1044:18: warning: negative integer implicitly converted to 
> unsigned type [-Wsign-conversion]
>    memcpy(&family, NLA_DATA(tb[CTRL_ATTR_FAMILY_ID]), sizeof(family));
>                    ^~~~~~~~
> if-linux.c: In function ‘_if_getssid_nl80211’:
> if-linux.c:1083:6: warning: negative integer implicitly converted to 
> unsigned type [-Wsign-conversion]
>        NLA_DATA(tb[NL80211_ATTR_BSS]),
>        ^~~~~~~~
> if-linux.c:1084:6: warning: negative integer implicitly converted to 
> unsigned type [-Wsign-conversion]
>        NLA_LEN(tb[NL80211_ATTR_BSS]),
>        ^~~~~~~
> if-linux.c:1091:18: warning: negative integer implicitly converted to 
> unsigned type [-Wsign-conversion]
>    memcpy(&status, NLA_DATA(bss[NL80211_BSS_STATUS]), sizeof(status));
>                    ^~~~~~~~
> if-linux.c:1098:7: warning: negative integer implicitly converted to 
> unsigned type [-Wsign-conversion]
>    ie = NLA_DATA(bss[NL80211_BSS_INFORMATION_ELEMENTS]);
>         ^~~~~~~~
> if-linux.c:1099:16: warning: negative integer implicitly converted to 
> unsigned type [-Wsign-conversion]
>    ie_len = (int)NLA_LEN(bss[NL80211_BSS_INFORMATION_ELEMENTS]);
>                  ^~~~~~~
> if-linux.c: In function ‘add_attr_nest’:
> if-linux.c:864:40: warning: conversion to ‘__u32 {aka unsigned int}’ 
> from ‘int’ may change the sign of the result [-Wsign-conversion]
>    ((struct rtattr *)(((ptrdiff_t)(nmsg))+NLMSG_ALIGN((nmsg)->nlmsg_len)))
>                                          ^
> if-linux.c:1611:9: note: in expansion of macro ‘NLMSG_TAIL’
>    nest = NLMSG_TAIL(n);
>           ^~~~~~~~~~
> if-linux.c: In function ‘add_attr_nest_end’:
> if-linux.c:864:40: warning: conversion to ‘__u32 {aka unsigned int}’ 
> from ‘int’ may change the sign of the result [-Wsign-conversion]
>    ((struct rtattr *)(((ptrdiff_t)(nmsg))+NLMSG_ALIGN((nmsg)->nlmsg_len)))
>                                          ^
> if-linux.c:1620:43: note: in expansion of macro ‘NLMSG_TAIL’
>    nest->rta_len = (unsigned short)((char *)NLMSG_TAIL(n) - (char *)nest);


Linux header issues.

>                                             ^~~~~~~~~~
> At top level:
> if-linux.c:107:22: warning: ‘ipv4_bcast_addr’ defined but not used 
> [-Wunused-const-variable=]
>   static const uint8_t ipv4_bcast_addr[] = {

Can fix this

>                        ^~~~~~~~~~~~~~~
>
> c) src/ipv4.c
> ipv4.c: In function ‘inet_getroutes’:
> ipv4.c:436:6: warning: assuming signed overflow does not occur when 
> simplifying conditional to constant [-Wstrict-overflow]
>     if (inet_routerhostroute(routes, ifp) == -1)
>        ^
>
> d) src/ipv6.c
> ipv6.c: In function ‘inet6_getroutes’:
> ipv6.c:2313:5: warning: assuming signed overflow does not occur when 
> simplifying conditional to constant [-Wstrict-overflow]
>    if (inet6_staticroutes(routes, ctx) == -1)
>       ^

Compiler bug maybe?
I don't see how a signed overvlow can occur here.

> e) src/ipv6nd.c
> ipv6nd.c: In function ‘ipv6nd_open’:
> ipv6nd.c:221:2: warning: negative integer implicitly converted to 
> unsigned type [-Wsign-conversion]
>    ICMP6_FILTER_SETPASS(ND_NEIGHBOR_ADVERT, &filt);
>    ^~~~~~~~~~~~~~~~~~~~
> ipv6nd.c:222:2: warning: negative integer implicitly converted to 
> unsigned type [-Wsign-conversion]
>    ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
>    ^~~~~~~~~~~~~~~~~~~~

Linux header issue.

> f) src/dhcp6.c
> dhcp6.c: In function ‘dhcp6_bind’:
> dhcp6.c:2948:21: warning: comparison between signed and unsigned integer 
> expressions [-Wsign-compare]
>      if (state->renew > diff.tv_sec)
>                       ^
> dhcp6.c:2954:22: warning: comparison between signed and unsigned integer 
> expressions [-Wsign-compare]
>      if (state->rebind > diff.tv_sec)
>                        ^
> dhcp6.c:2960:22: warning: comparison between signed and unsigned integer 
> expressions [-Wsign-compare]
>      if (state->expire > diff.tv_sec)

Can probably fix this.

>                        ^
>
> g) compat/crypt/md5.c/.h
> In file included from ../compat/crypt/md5.c:23:0:
> ../compat/crypt/md5.c: In function ‘MD5Final’:
> ../compat/crypt/md5.h:22:26: warning: conversion to ‘size_t {aka 
> unsigned int}’ from ‘uint64_t {aka long long unsigned int}’ may alter 
> its value [-Wconversion]
>   #define MD5_BLOCK_LENGTH 64
>                            ^
> ../compat/crypt/md5.c:228:11: note: in expansion of macro 
> ‘MD5_BLOCK_LENGTH’
>    padlen = MD5_BLOCK_LENGTH -
>             ^~~~~~~~~~~~~~~~

Can probably fix this.

Really need compiler version used here.

Roy