warning: ‘void* memset(void*, int, size_t)’ specified size 18446744073709551613 exceeds maximum object size 9223372036854775807 [-Wstringop-overflow=]

[bhalevy]

Seen when building seastar from scylla.

[38/69] Building CXX object CMakeFiles/seastar.dir/src/core/prometheus.cc.o
In file included from ../../include/seastar/core/ragel.hh:24,
                 from gen/include/seastar/http/request_parser.hh:24,
                 from ../../include/seastar/http/httpd.hh:24,
                 from ../../include/seastar/core/prometheus.hh:24,
                 from ../../src/core/prometheus.cc:22:
In constructor ‘seastar::basic_sstring<char_type, Size, max_size, NulTerminate>::basic_sstring(size_t, char_type) [with char_type = char; Size = unsigned int; Size max_size = 15; bool NulTerminate = true]’,
    inlined from ‘void seastar::basic_sstring<char_type, Size, max_size, NulTerminate>::resize(size_t, char_type) [with char_type = char; Size = unsigned int; Size max_size = 15; bool NulTerminate = true]’ at ../../include/seastar/core/sstring.hh:360:19,
    inlined from ‘bool seastar::prometheus::metrics_handler::trim_asterisk(seastar::sstring&)’ at ../../src/core/prometheus.cc:654:24,
    inlined from ‘virtual seastar::future<std::unique_ptr<seastar::httpd::reply, std::default_delete<seastar::httpd::reply> > > seastar::prometheus::metrics_handler::handle(const sstring&, std::unique_ptr<seastar::httpd::request>, std::unique_ptr<seastar::httpd::reply>)’ at ../../src/core/prometheus.cc:666:36:
../../include/seastar/core/sstring.hh:238:15: warning: ‘void* memset(void*, int, size_t)’ specified size 18446744073709551613 exceeds maximum object size 9223372036854775807 [-Wstringop-overflow=]
         memset(begin(), x, size);
         ~~~~~~^~~~~~~~~~~~~~~~~~

$ git submodule status seastar
 2f3573178e7268f36d21ecdf09b4a83e22665579 seastar (seastar-18.08.0-343-g2f357317)

src/core/prometheus.cc:
metrics_handler::trim_asterisk:

653        if (boost::algorithm::ends_with(name, "%2A")) {
654           name.resize(name.length() - 3);
>>> Note that int64_t(18446744073709551613) == -3
>>> oddly, can name.length() be 0 at this point?
655           return true;
656       }

[espindola]

I have delta running on this.

[espindola]

Finally got back to this and reported https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89337

[bhalevy]

Finally got back to this and reported https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89337

Thanks!