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

[Vladimir Kempik]

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