RFR[16] 8248495: [macos] zerovm is broken due to libffi headers location

[jiefu(傅杰)]

Hi Vladimir and Magnus,

How about configuring with --with-libffi=... like this:
        --with-libffi=/usr/local/Cellar/libffi/3.2.1/lib/libffi-3.2.1     --disable-warnings-as-errors

I can compile zero vm on our macos platforms with that configuration.

Thanks.
Best regards,
Jie

On 2020/7/1, 3:15 AM, "build-dev on behalf of Vladimir Kempik" <build-dev-retn at openjdk.java.net on behalf of vkempik at azul.com> wrote:

    Hello
    
    I agree modding  hpp files is a bad idea
    
    Thanks for idea with setting LIBFFI_CFLAGS
    
    here is updated webrev: http://cr.openjdk.java.net/~vkempik/8248495/webrev.01/
    
    AC_CHECK_HEADERS ignored CFLAGS for some reason, so modding header_name for it was still needed.
    This special case only applies to macos/clang when sysroot is set and no libffi configure options is used. (which is default case)
    
    Thanks, Vladimir
    
    
    > 30 июня 2020 г., в 19:46, Magnus Ihse Bursie <magnus.ihse.bursie at oracle.com> написал(а):
    > 
    > Vladimir,
    > 
    > This looks like it can break in other situation than your specific case.
    > 
    > It sounds like you should set LIBFFI_CFLAGS= to  -I<path to your ffi installation>, such that "<path to your ffi installation>/ffi.h" exists. In particular, the change of include path in globalDefinitions_zero.hpp looks bad.
    > 
    > /Magnus
    > 
    > On 2020-06-30 15:33, Vladimir Kempik wrote:
    >> Hello
    >> 
    >> Please review this fix for zero vm building on macos.
    >> 
    >> The issue comes from the libffi, it’s headers are located inside usr/include/ffi/ folder in Macos.sdk, so it can’t be found by configure script.
    >> 
    >> If one wants to use system’s libffi and pass path to libffi via configure argument as --with-libffi-include=/usr/include/ffi, then it won’t be found by configure because clang will look exactly in /usr/include/ffi, but not in macos.sdk
    >> The system, at least on 10.15 doesn’t have /usr/includes at all.
    >> 
    >> This patch makes jdk to look for ffi/ffi.h header in case of Macos/clang and no --with-libffi-include argument.
    >> 
    >> However there is one issue with this patch, if --with-libffi-include passed then c++ code will still try to include <ffi/ffi.h>
    >> 
    >> I’m not sure which way is the best for such rare case. it could be possible to define include filename in configure and pass it via -D and CFLAGS to c++ code.
    >> 
    >> 
    >> The webrev - http://cr.openjdk.java.net/~vkempik/8248495/webrev.00/
    >> 
    >> The bug - https://bugs.openjdk.java.net/browse/JDK-8248495
    >> 
    >> Thanks, Vladimir