GCC 15.1.1 new warnings

[rzalamena]

Here is a list of new gcc warnings in FRR:

1. isisd/isis_tlvs.c:6979

      In function ‘restore_auth_md5’,
       inlined from ‘update_auth_hmac_md5’ at isisd/isis_tlvs.c:7006:3,
       inlined from ‘update_auth’ at isisd/isis_tlvs.c:7015:4,
       inlined from ‘isis_pack_tlvs’ at isisd/isis_tlvs.c:7186:2:
   isisd/isis_tlvs.c:6979:9: warning: ‘checksum’ may be used uninitialized [-Wmaybe-uninitialized]
    6979 |         memcpy(STREAM_DATA(s) + LSP_CHECKSUM_OFF, &checksum, sizeof(checksum));
         |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   isisd/isis_tlvs.c: In function ‘isis_pack_tlvs’:
   isisd/isis_tlvs.c:6986:18: note: ‘checksum’ was declared here
    6986 |         uint16_t checksum, rem_lifetime;
         |                  ^~~~~~~~
   In function ‘restore_auth_md5’,
       inlined from ‘update_auth_hmac_md5’ at isisd/isis_tlvs.c:7006:3,
       inlined from ‘update_auth’ at isisd/isis_tlvs.c:7015:4,
       inlined from ‘isis_pack_tlvs’ at isisd/isis_tlvs.c:7186:2:
   isisd/isis_tlvs.c:6977:9: warning: ‘rem_lifetime’ may be used uninitialized [-Wmaybe-uninitialized]
    6977 |         memcpy(STREAM_DATA(s) + LSP_REM_LIFETIME_OFF, &rem_lifetime,
         |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    6978 |                sizeof(rem_lifetime));
         |                ~~~~~~~~~~~~~~~~~~~~~
   isisd/isis_tlvs.c: In function ‘isis_pack_tlvs’:
   isisd/isis_tlvs.c:6986:28: note: ‘rem_lifetime’ was declared here
    6986 |         uint16_t checksum, rem_lifetime;
         |                            ^~~~~~~~~~~~
   

2. lib/yang_wrappers.c:34

   In file included from ./lib/zebra.h:49,
                    from lib/yang_wrappers.c:7:
   lib/yang_wrappers.c: In function 'yang_dnode_get_bool':
   lib/yang_wrappers.c:23:34: warning: 'va_start' macro used with additional arguments other than identifier of the last named argument [-Wvarargs]
      23 |                 va_start(_Y__ap, (xpath_fmt));                                                     \
         |                                  ^~~~~~~~~~~
   lib/yang_wrappers.c:127:18: note: in expansion of macro 'YANG_DNODE_XPATH_GET_VALUE'
     127 |         dvalue = YANG_DNODE_XPATH_GET_VALUE(dnode, xpath_fmt);
         |                  ^~~~~~~~~~~~~~~~~~~~~~~~~~
   lib/yang_wrappers.c: In function 'yang_dnode_get_dec64':
   lib/yang_wrappers.c:23:34: warning: 'va_start' macro used with additional arguments other than identifier of the last named argument [-Wvarargs]
      23 |                 va_start(_Y__ap, (xpath_fmt));                                                     \
         |                                  ^~~~~~~~~~~
   lib/yang_wrappers.c:181:18: note: in expansion of macro 'YANG_DNODE_XPATH_GET_VALUE'
     181 |         dvalue = YANG_DNODE_XPATH_GET_VALUE(dnode, xpath_fmt);
         |                  ^~~~~~~~~~~~~~~~~~~~~~~~~~
   lib/yang_wrappers.c: In function 'yang_dnode_get_enum':
   lib/yang_wrappers.c:23:34: warning: 'va_start' macro used with additional arguments other than identifier of the last named argument [-Wvarargs]
      23 |                 va_start(_Y__ap, (xpath_fmt));                                                     \
         |                                  ^~~~~~~~~~~
   lib/yang_wrappers.c:279:18: note: in expansion of macro 'YANG_DNODE_XPATH_GET_VALUE'
     279 |         dvalue = YANG_DNODE_XPATH_GET_VALUE(dnode, xpath_fmt);
         |                  ^~~~~~~~~~~~~~~~~~~~~~~~~~
   lib/yang_wrappers.c: In function 'yang_dnode_get_int8':
   lib/yang_wrappers.c:23:34: warning: 'va_start' macro used with additional arguments other than identifier of the last named argument [-Wvarargs]
      23 |                 va_start(_Y__ap, (xpath_fmt));                                                     \
         |                                  ^~~~~~~~~~~
   lib/yang_wrappers.c:319:18: note: in expansion of macro 'YANG_DNODE_XPATH_GET_VALUE'
     319 |         dvalue = YANG_DNODE_XPATH_GET_VALUE(dnode, xpath_fmt);
         |                  ^~~~~~~~~~~~~~~~~~~~~~~~~~
   lib/yang_wrappers.c: In function 'yang_dnode_get_int16':
   lib/yang_wrappers.c:23:34: warning: 'va_start' macro used with additional arguments other than identifier of the last named argument [-Wvarargs]
      23 |                 va_start(_Y__ap, (xpath_fmt));                                                     \
         |                                  ^~~~~~~~~~~
   lib/yang_wrappers.c:358:18: note: in expansion of macro 'YANG_DNODE_XPATH_GET_VALUE'
     358 |         dvalue = YANG_DNODE_XPATH_GET_VALUE(dnode, xpath_fmt);
         |                  ^~~~~~~~~~~~~~~~~~~~~~~~~~
   lib/yang_wrappers.c: In function 'yang_dnode_get_int32':
   lib/yang_wrappers.c:23:34: warning: 'va_start' macro used with additional arguments other than identifier of the last named argument [-Wvarargs]
      23 |                 va_start(_Y__ap, (xpath_fmt));                                                     \
         |                                  ^~~~~~~~~~~
   lib/yang_wrappers.c:397:18: note: in expansion of macro 'YANG_DNODE_XPATH_GET_VALUE'
     397 |         dvalue = YANG_DNODE_XPATH_GET_VALUE(dnode, xpath_fmt);
         |                  ^~~~~~~~~~~~~~~~~~~~~~~~~~
   lib/yang_wrappers.c: In function 'yang_dnode_get_int64':
     CC       lib/zlog_5424.lo
   lib/yang_wrappers.c:23:34: warning: 'va_start' macro used with additional arguments other than identifier of the last named argument [-Wvarargs]
      23 |                 va_start(_Y__ap, (xpath_fmt));                                                     \
         |                                  ^~~~~~~~~~~
   lib/yang_wrappers.c:436:18: note: in expansion of macro 'YANG_DNODE_XPATH_GET_VALUE'
     436 |         dvalue = YANG_DNODE_XPATH_GET_VALUE(dnode, xpath_fmt);
         |                  ^~~~~~~~~~~~~~~~~~~~~~~~~~
   lib/yang_wrappers.c: In function 'yang_dnode_get_uint8':
   lib/yang_wrappers.c:23:34: warning: 'va_start' macro used with additional arguments other than identifier of the last named argument [-Wvarargs]
      23 |                 va_start(_Y__ap, (xpath_fmt));                                                     \
         |                                  ^~~~~~~~~~~
   lib/yang_wrappers.c:475:18: note: in expansion of macro 'YANG_DNODE_XPATH_GET_VALUE'
     475 |         dvalue = YANG_DNODE_XPATH_GET_VALUE(dnode, xpath_fmt);
         |                  ^~~~~~~~~~~~~~~~~~~~~~~~~~
   lib/yang_wrappers.c: In function 'yang_dnode_get_uint16':
   lib/yang_wrappers.c:23:34: warning: 'va_start' macro used with additional arguments other than identifier of the last named argument [-Wvarargs]
      23 |                 va_start(_Y__ap, (xpath_fmt));                                                     \
         |                                  ^~~~~~~~~~~
   lib/yang_wrappers.c:514:18: note: in expansion of macro 'YANG_DNODE_XPATH_GET_VALUE'
     514 |         dvalue = YANG_DNODE_XPATH_GET_VALUE(dnode, xpath_fmt);
         |                  ^~~~~~~~~~~~~~~~~~~~~~~~~~
   lib/yang_wrappers.c: In function 'yang_dnode_get_uint32':
   lib/yang_wrappers.c:23:34: warning: 'va_start' macro used with additional arguments other than identifier of the last named argument [-Wvarargs]
      23 |                 va_start(_Y__ap, (xpath_fmt));                                                     \
         |                                  ^~~~~~~~~~~
   lib/yang_wrappers.c:553:18: note: in expansion of macro 'YANG_DNODE_XPATH_GET_VALUE'
     553 |         dvalue = YANG_DNODE_XPATH_GET_VALUE(dnode, xpath_fmt);
         |                  ^~~~~~~~~~~~~~~~~~~~~~~~~~
   lib/yang_wrappers.c: In function 'yang_dnode_get_uint64':
   lib/yang_wrappers.c:23:34: warning: 'va_start' macro used with additional arguments other than identifier of the last named argument [-Wvarargs]
      23 |                 va_start(_Y__ap, (xpath_fmt));                                                     \
         |                                  ^~~~~~~~~~~
   lib/yang_wrappers.c:592:18: note: in expansion of macro 'YANG_DNODE_XPATH_GET_VALUE'
     592 |         dvalue = YANG_DNODE_XPATH_GET_VALUE(dnode, xpath_fmt);
         |                  ^~~~~~~~~~~~~~~~~~~~~~~~~~
   lib/yang_wrappers.c: In function 'yang_dnode_get_string':
   lib/yang_wrappers.c:34:34: warning: 'va_start' macro used with additional arguments other than identifier of the last named argument [-Wvarargs]
      34 |                 va_start(_y__ap, (xpath_fmt));                                                     \
         |                                  ^~~~~~~~~~~
   lib/yang_wrappers.c:624:16: note: in expansion of macro 'YANG_DNODE_XPATH_GET_CANON'
     624 |         return YANG_DNODE_XPATH_GET_CANON(dnode, xpath_fmt);
         |                ^~~~~~~~~~~~~~~~~~~~~~~~~~
   lib/yang_wrappers.c: In function 'yang_dnode_get_string_buf':
   lib/yang_wrappers.c:34:34: warning: 'va_start' macro used with additional arguments other than identifier of the last named argument [-Wvarargs]
      34 |                 va_start(_y__ap, (xpath_fmt));                                                     \
         |                                  ^~~~~~~~~~~
   lib/yang_wrappers.c:631:29: note: in expansion of macro 'YANG_DNODE_XPATH_GET_CANON'
     631 |         const char *canon = YANG_DNODE_XPATH_GET_CANON(dnode, xpath_fmt);
         |                             ^~~~~~~~~~~~~~~~~~~~~~~~~~
   lib/yang_wrappers.c: In function 'yang_dnode_get_binary_buf':
   lib/yang_wrappers.c:34:34: warning: 'va_start' macro used with additional arguments other than identifier of the last named argument [-Wvarargs]
      34 |                 va_start(_y__ap, (xpath_fmt));                                                     \
         |                                  ^~~~~~~~~~~
   lib/yang_wrappers.c:708:17: note: in expansion of macro 'YANG_DNODE_XPATH_GET_CANON'
     708 |         canon = YANG_DNODE_XPATH_GET_CANON(dnode, xpath_fmt);
         |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~
   lib/yang_wrappers.c: In function 'yang_dnode_get_prefix':
   lib/yang_wrappers.c:34:34: warning: 'va_start' macro used with additional arguments other than identifier of the last named argument [-Wvarargs]
      34 |                 va_start(_y__ap, (xpath_fmt));                                                     \
         |                                  ^~~~~~~~~~~
   lib/yang_wrappers.c:790:17: note: in expansion of macro 'YANG_DNODE_XPATH_GET_CANON'
     790 |         canon = YANG_DNODE_XPATH_GET_CANON(dnode, xpath_fmt);
         |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~
   lib/yang_wrappers.c: In function 'yang_dnode_get_ipv4':
   lib/yang_wrappers.c:34:34: warning: 'va_start' macro used with additional arguments other than identifier of the last named argument [-Wvarargs]
      34 |                 va_start(_y__ap, (xpath_fmt));                                                     \
         |                                  ^~~~~~~~~~~
   lib/yang_wrappers.c:829:29: note: in expansion of macro 'YANG_DNODE_XPATH_GET_CANON'
     829 |         const char *canon = YANG_DNODE_XPATH_GET_CANON(dnode, xpath_fmt);
         |                             ^~~~~~~~~~~~~~~~~~~~~~~~~~
   lib/yang_wrappers.c: In function 'yang_dnode_get_ipv4p':
   lib/yang_wrappers.c:34:34: warning: 'va_start' macro used with additional arguments other than identifier of the last named argument [-Wvarargs]
      34 |                 va_start(_y__ap, (xpath_fmt));                                                     \
         |                                  ^~~~~~~~~~~
   lib/yang_wrappers.c:872:29: note: in expansion of macro 'YANG_DNODE_XPATH_GET_CANON'
     872 |         const char *canon = YANG_DNODE_XPATH_GET_CANON(dnode, xpath_fmt);
         |                             ^~~~~~~~~~~~~~~~~~~~~~~~~~
   lib/yang_wrappers.c: In function 'yang_dnode_get_ipv6':
   lib/yang_wrappers.c:34:34: warning: 'va_start' macro used with additional arguments other than identifier of the last named argument [-Wvarargs]
      34 |                 va_start(_y__ap, (xpath_fmt));                                                     \
         |                                  ^~~~~~~~~~~
   lib/yang_wrappers.c:911:29: note: in expansion of macro 'YANG_DNODE_XPATH_GET_CANON'
     911 |         const char *canon = YANG_DNODE_XPATH_GET_CANON(dnode, xpath_fmt);
         |                             ^~~~~~~~~~~~~~~~~~~~~~~~~~
   lib/yang_wrappers.c: In function 'yang_dnode_get_ipv6p':
   lib/yang_wrappers.c:34:34: warning: 'va_start' macro used with additional arguments other than identifier of the last named argument [-Wvarargs]
      34 |                 va_start(_y__ap, (xpath_fmt));                                                     \
         |                                  ^~~~~~~~~~~
   lib/yang_wrappers.c:955:29: note: in expansion of macro 'YANG_DNODE_XPATH_GET_CANON'
     955 |         const char *canon = YANG_DNODE_XPATH_GET_CANON(dnode, xpath_fmt);
         |                             ^~~~~~~~~~~~~~~~~~~~~~~~~~
   lib/yang_wrappers.c: In function 'yang_dnode_get_ip':
   lib/yang_wrappers.c:34:34: warning: 'va_start' macro used with additional arguments other than identifier of the last named argument [-Wvarargs]
      34 |                 va_start(_y__ap, (xpath_fmt));                                                     \
         |                                  ^~~~~~~~~~~
   lib/yang_wrappers.c:994:29: note: in expansion of macro 'YANG_DNODE_XPATH_GET_CANON'
     994 |         const char *canon = YANG_DNODE_XPATH_GET_CANON(dnode, xpath_fmt);
         |                             ^~~~~~~~~~~~~~~~~~~~~~~~~~
   lib/yang_wrappers.c: In function 'yang_dnode_get_mac':
   lib/yang_wrappers.c:34:34: warning: 'va_start' macro used with additional arguments other than identifier of the last named argument [-Wvarargs]
      34 |                 va_start(_y__ap, (xpath_fmt));                                                     \
         |                                  ^~~~~~~~~~~
   lib/yang_wrappers.c:1029:29: note: in expansion of macro 'YANG_DNODE_XPATH_GET_CANON'
    1029 |         const char *canon = YANG_DNODE_XPATH_GET_CANON(dnode, xpath_fmt);
         |                             ^~~~~~~~~~~~~~~~~~~~~~~~~~
   lib/yang_wrappers.c: In function 'yang_dnode_get_date_and_timespec':
   lib/yang_wrappers.c:34:34: warning: 'va_start' macro used with additional arguments other than identifier of the last named argument [-Wvarargs]
      34 |                 va_start(_y__ap, (xpath_fmt));                                                     \
         |                                  ^~~~~~~~~~~
   lib/yang_wrappers.c:1056:29: note: in expansion of macro 'YANG_DNODE_XPATH_GET_CANON'
    1056 |         const char *canon = YANG_DNODE_XPATH_GET_CANON(dnode, xpath_fmt);
         |                             ^~~~~~~~~~~~~~~~~~~~~~~~~~
   lib/yang_wrappers.c: In function 'yang_dnode_get_date_and_time':
   lib/yang_wrappers.c:34:34: warning: 'va_start' macro used with additional arguments other than identifier of the last named argument [-Wvarargs]
      34 |                 va_start(_y__ap, (xpath_fmt));                                                     \
         |                                  ^~~~~~~~~~~
   lib/yang_wrappers.c:1069:29: note: in expansion of macro 'YANG_DNODE_XPATH_GET_CANON'
    1069 |         const char *canon = YANG_DNODE_XPATH_GET_CANON(dnode, xpath_fmt);
         |                             ^~~~~~~~~~~~~~~~~~~~~~~~~~
   lib/yang_wrappers.c: In function 'yang_dnode_get_bandwidth_ieee_float32':
   lib/yang_wrappers.c:34:34: warning: 'va_start' macro used with additional arguments other than identifier of the last named argument [-Wvarargs]
      34 |                 va_start(_y__ap, (xpath_fmt));                                                     \
         |                                  ^~~~~~~~~~~
   lib/yang_wrappers.c:1082:29: note: in expansion of macro 'YANG_DNODE_XPATH_GET_CANON'
    1082 |         const char *canon = YANG_DNODE_XPATH_GET_CANON(dnode, xpath_fmt);
         |
   

3. lib/northbound_oper.c:422

   In file included from ./lib/zebra.h:127,
                    from lib/northbound_oper.c:11:
   In function 'nb_op_xpath_to_trunk',
       inlined from 'nb_op_ys_init_node_infos' at lib/northbound_oper.c:569:8:
   lib/darr.h:110:55: warning: array subscript -1 is outside array bounds of 'char[]' [-Warray-bounds=]
     110 | #define darr_cap(A) (((A) == NULL) ? 0 : _darr_meta(A)->cap)
         |                                                       ^
   ./lib/assert/assert.h:58:39: note: in definition of macro 'assert'
      58 |                 if (__builtin_expect((expr_) ? 0 : 1, 0))                      \
         |                                       ^~~~~
   lib/darr.h:169:43: note: in expansion of macro 'darr_cap'
     169 |                         assert((long long)darr_cap(A) >= (long long)(L));      \
         |                                           ^~~~~~~~
   lib/darr.h:679:17: note: in expansion of macro 'darr_setlen'
     679 |                 darr_setlen((D), (size_t)_d__size);                                                \
         |                 ^~~~~~~~~~~
   lib/darr.h:682:30: note: in expansion of macro 'darr_in_strdup_cap'
     682 | #define darr_in_strdup(D, S) darr_in_strdup_cap(D, S, 1)
         |                              ^~~~~~~~~~~~~~~~~~
   lib/northbound_oper.c:422:9: note: in expansion of macro 'darr_in_strdup'
     422 |         darr_in_strdup(xpath, xpath_in);
         |         ^~~~~~~~~~~~~~
   

4. bgpd/bgp_ecommunity.c:580:

     580 |         static const char str_color[5] = "color";
         |
   

5. ospfd/ospf_zebra.c:1283

   In file included from ./lib/yang_wrappers.h:11,
                    from ./lib/yang.h:17,
                    from ./lib/northbound.h:14,
                    from ./lib/vty.h:26,
                    from ./lib/command.h:11,
                    from ospfd/ospf_zebra.c:10:
   In function ‘is_default_prefix4’,
       inlined from ‘is_default_prefix’ at ./lib/prefix.h:534:10,
       inlined from ‘ospf_zebra_read_route’ at ospfd/ospf_zebra.c:1316:7:
   ./lib/prefix.h:516:46: warning: ‘*(const struct prefix_ipv4 *)((char *)&pgen + offsetof(struct prefix, family)).prefixlen’ may be used uninitialized [-Wmaybe-uninitialized]
     516 |         return p && p->family == AF_INET && p->prefixlen == 0
         |                                             ~^~~~~~~~~~~
   ospfd/ospf_zebra.c: In function ‘ospf_zebra_read_route’:
   ospfd/ospf_zebra.c:1283:23: note: ‘pgen’ declared here
    1283 |         struct prefix pgen;
         |                       ^~~~
   In function ‘is_default_prefix6’,
       inlined from ‘is_default_prefix’ at ./lib/prefix.h:536:10,
       inlined from ‘ospf_zebra_read_route’ at ospfd/ospf_zebra.c:1316:7:
   ./lib/prefix.h:522:47: warning: ‘*(const struct prefix_ipv6 *)((char *)&pgen + offsetof(struct prefix, family)).prefixlen’ may be used uninitialized [-Wmaybe-uninitialized]
     522 |         return p && p->family == AF_INET6 && p->prefixlen == 0
         |                                              ~^~~~~~~~~~~
   ospfd/ospf_zebra.c: In function ‘ospf_zebra_read_route’:
   ospfd/ospf_zebra.c:1283:23: note: ‘pgen’ declared here
    1283 |         struct prefix pgen;
         |                       ^~~~
   

6. lib/printf/vfprintf.c:184

   lib/printf/vfprintf.c: In function 'vbprintfrr':
   lib/printf/vfprintf.c:184:45: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (17 chars into 16 available) [-Wunterminated-string-initialization]
     184 |         static const char xdigs_lower[16] = "0123456789abcdef";
         |                                             ^~~~~~~~~~~~~~~~~~
   lib/printf/vfprintf.c:185:45: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (17 chars into 16 available) [-Wunterminated-string-initialization]
     185 |         static const char xdigs_upper[16] = "0123456789ABCDEF";
         |
   

[rzalamena]

Not all issues are resolved (see unmarked entries).

[mjstapp]

hmm - I get a clean build in an ubuntu 25 vm, which has gcc 15 (something). can you say more about what you see?

Not all issues are resolved (see unmarked entries).

[rzalamena]

@mjstapp are you using the configure option --enable-dev-build? You could also manually enable the warning by passing it to configure as well (example: ./configure 'CFLAGS=-Wmaybe-uninitialized')

[mjstapp]

yes, I used dev-build, and I even added Wmaybe-uninitialized.
if you're talking about the isis_tlvs.c warning, are you sure you have the latest update? I did initialize those locals, so ...

this is the gcc that I got with ubuntu25, fwiw:

$ gcc --version
gcc (Ubuntu 15-20250404-0ubuntu1) 15.0.1 20250404 (experimental) [master r15-9193-g08e803aa9be]
Copyright (C) 2025 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

@mjstapp are you using the configure option --enable-dev-build? You could also manually enable the warning by passing it to configure as well (example: ./configure 'CFLAGS=-Wmaybe-uninitialized')

[rzalamena]

Fedora's GCC version is a bit newer (as shown in issue title):

$ gcc --version
gcc (GCC) 15.1.1 20250521 (Red Hat 15.1.1-2)
Copyright (C) 2025 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

[rzalamena]

I just rebased and tried the latest code (as of today) and all warnings are gone. Thanks!