JDK Build on Fedora 28

[Patrick Reinhart]

I went thru the remaining warnings, that show up when building under gcc 
8.1.1 on Fedora 28:

/home/rep/sources/jdk/src/jdk.jdwp.agent/share/native/libjdwp/debugInit.c: 
In function ‘jniFatalError’:
/home/rep/sources/jdk/src/jdk.jdwp.agent/share/native/libjdwp/debugInit.c:650:24: 
warning: passing argument 1 to restrict-qualified parameter aliases with 
argument 4 [-Wrestrict]
          (void)snprintf(buf, sizeof(buf), "JDWP %s", buf);
                         ^~~                          ~~~
/home/rep/sources/jdk/src/jdk.jdwp.agent/share/native/libjdwp/debugInit.c: 
In function ‘jniFatalError.constprop’:
/home/rep/sources/jdk/src/jdk.jdwp.agent/share/native/libjdwp/debugInit.c:650:48: 
warning: ‘%s’ directive output may be truncated writing up to 511 bytes 
into a region of size 507 [-Wformat-truncation=]
          (void)snprintf(buf, sizeof(buf), "JDWP %s", buf);
                                                 ^~   ~~~
/home/rep/sources/jdk/src/jdk.jdwp.agent/share/native/libjdwp/debugInit.c:650:15: 
note: ‘snprintf’ output between 6 and 517 bytes into a destination of 
size 512
          (void)snprintf(buf, sizeof(buf), "JDWP %s", buf);
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/rep/sources/jdk/src/jdk.jdwp.agent/share/native/libjdwp/log_messages.c: 
In function ‘log_message_end’:
/home/rep/sources/jdk/src/jdk.jdwp.agent/share/native/libjdwp/log_messages.c:75:24: 
warning: ‘%.3d’ directive output may be truncated writing between 3 and 
11 bytes into a region of size between 0 and 80 [-Wformat-truncation=]
                     "%s.%.3d %s", timestamp_prefix,
                         ^~~~
/home/rep/sources/jdk/src/jdk.jdwp.agent/share/native/libjdwp/log_messages.c:75:20: 
note: using the range [-2147483648, 2147483647] for directive argument
                     "%s.%.3d %s", timestamp_prefix,
                     ^~~~~~~~~~~~
/home/rep/sources/jdk/src/jdk.jdwp.agent/share/native/libjdwp/log_messages.c:74:11: 
note: ‘snprintf’ output between 6 and 174 bytes into a destination of 
size 81
      (void)snprintf(tbuf, ltbuf,
            ^~~~~~~~~~~~~~~~~~~~~
                     "%s.%.3d %s", timestamp_prefix,
                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                     (int)(millisecs), timestamp_postfix);
                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


and a lot of those:

/home/rep/sources/jdk/src/java.desktop/share/native/libfontmanager/harfbuzz/hb-debug.hh:130:1: 
warning: explicit specialization ‘void _hb_debug_msg_va(const char*, 
const void*, const char*, bool, unsigned int, int, const char*, 
__va_list_tag*) [with int max_level = 0]’ may be missing attributes 
[-Wmissing-attributes]
  _hb_debug_msg_va<0> (const char *what HB_UNUSED,
  ^~~~~~~~~~~~~~~~~~~




On 2018-06-19 11:20, Andrew Haley wrote:
> On 06/19/2018 03:30 AM, David Holmes wrote:
>> I've filed:
>> 
>> https://bugs.openjdk.java.net/browse/JDK-8205201
>> 
>> for the underlying issue. Hotspot folk need to check if the warnings 
>> are
>> legitmate or not. If not then we may need to disable this warning in 
>> the
>> build.
> 
> The warnings are legitimate: it's unnecessarily hairy code.  It could
> easily be rewritten to use memcpy(), would be obviously guaranteed not
> to exceed array bounds, and might even be slightly faster.  Fixing
> these warnings is an opportunity to clean up some of this code.