gcc 7.3.1 build - warnings as errors in harfbuzz

[Baesken, Matthias]

Hello  , when  compiling   jdk/jdk   with  gcc 7.3.1    on linux x86_64 (or 
also on   linux ppc64)   I run into this build error :


/open_jdk/jdk_just_clone/jdk/src/java.desktop/share/native/libfontmanager/harfbuzz/hb-common.cc:
 In function 'void hb_variation_to_string(hb_variation_t*, char*, unsigned 
int)':
/open_jdk/jdk_just_clone/jdk/src/java.desktop/share/native/libfontmanager/harfbuzz/hb-common.cc:1066:27:
 error: '%g' directive output between 1 and 18446744073709551615 bytes may 
cause result to exceed 'INT_MAX' [-Werror=format-truncation=]
   len += MAX (0, snprintf (s + len, ARRAY_LENGTH (s) - len, "%g", 
variation->value));
                  
~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/open_jdk/jdk_just_clone/jdk/src/java.desktop/share/native/libfontmanager/harfbuzz/hb-common.cc:1066:27:
 note: assuming directive output of 2147488582 bytes
cc1plus: all warnings being treated as errors

(build is a product - build)

Setting –disable-warnings-as-errors  works  as a workaround  ,  but of course 
this is not really   what we want to do .

Fixing  in the    harfbuzz   sources  in OpenJDk  might be also not so nice 
because it would clash with imports of new versions of harfbuzz .
Do you think we could disable  the specific warning for the library compilation 
?

Any other great suggestions 😉 ?


Thanks, Matthias