gcc 7.3.1 build - warnings as errors in harfbuzz

[Baesken, Matthias]

Hi Erik,  so I think I could disable  the warning here :


Awt2dLibraries.gmk
---------------------------------

$(eval $(call SetupJdkLibrary, BUILD_LIBFONTMANAGER, \
    NAME := fontmanager, \
  ....
    WARNINGS_AS_ERRORS_xlc := false, \
    DISABLED_WARNINGS_gcc := format-truncation sign-compare int-to-pointer-cast \
        type-limits missing-field-initializers implicit-fallthrough \
        strict-aliasing undef unused-function, \
    DISABLED_WARNINGS_CXX_gcc := format-truncation  reorder delete-non-virtual-dtor strict-overflow \
        maybe-uninitialized, \
 ...

(add   format-truncation    for gcc in the  warning-disabling section).
However this would disable it also for other versions of gcc  where the issue never showed up .

Do you think this is fine  (and safe for older gcc) ?


Best regards, Matthias

> -----Original Message-----
> From: Erik Joelsson <erik.joelsson at oracle.com>
> Sent: Mittwoch, 10. Oktober 2018 17:33
> To: Baesken, Matthias <matthias.baesken at sap.com>; 'build-
> dev at openjdk.java.net' <build-dev at openjdk.java.net>
> Subject: Re: gcc 7.3.1 build - warnings as errors in harfbuzz
> 
> In this case, disabling the warning seems like the right thing to do.
> 
> /Erik
> 
> 
> On 2018-10-10 06:14, Baesken, Matthias wrote:
> > 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/libfontmanag
> er/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/libfontmanag
> er/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/libfontmanag
> er/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