CppInterpreter

[Severin Gehwolf]

Hi,

On Wed, 2015-12-16 at 17:18 +0100, Sebastian Sickelmann wrote:
> Hi,
> 
> is it possible to compile openjdk with --with-jvm-interpreter=cpp but
> without --with-jvm-variants=zero ?
> 
> I am getting the following error when i try it on the actual
> http://hg.openjdk.java.net/jdk9/hs-rt/hotspot sources.
> 
> Building target 'images' in configuration
> 'linux-x86_64-normal-server-slowdebug'
> ../../../../../hotspot/src/cpu/x86/vm/frame_x86.cpp: In member function
> ‘bool frame::safe_for_sender(JavaThread*)’:
> ../../../../../hotspot/src/cpu/x86/vm/frame_x86.cpp:139:53: error:
> ‘interpreter_frame_sender_sp_offset’ is not a member of ‘frame’
>        sender_unextended_sp = (intptr_t*)
> this->fp()[frame::interpreter_frame_sender_sp_offset];
>                                                      ^
> ../../../../../hotspot/src/cpu/x86/vm/frame_x86.cpp: In member function
> ‘void frame::describe_pd(FrameValues&, int)’:
> ../../../../../hotspot/src/cpu/x86/vm/frame_x86.cpp:698:48: error: a
> function-definition is not allowed here before ‘{’ token
>  intptr_t *frame::initial_deoptimization_info() {
>                                                 ^
> ../../../../../hotspot/src/cpu/x86/vm/frame_x86.cpp:703:34: error: a
> function-definition is not allowed here before ‘{’ token
>  intptr_t* frame::real_fp() const {
>                                   ^
> ../../../../../hotspot/src/cpu/x86/vm/frame_x86.cpp:720:1: error:
> expected ‘}’ at end of input
>  }
> 
> For the errors in line 698, 703 and 720 i think there is a problem with
> the #ifdefs and the curly braces.
> 
> Maybe the following patch does the trick:
> 
> diff -r f0141966004b src/cpu/x86/vm/frame_x86.cpp
> --- a/src/cpu/x86/vm/frame_x86.cpp    Tue Dec 15 17:57:08 2015 +0000
> +++ b/src/cpu/x86/vm/frame_x86.cpp    Wed Dec 16 16:40:07 2015 +0100
> @@ -690,8 +690,8 @@
>        values.describe(frame_no, fp() - i, err_msg("call_stub word fp -
> %d", i));
>      }
>  #endif // AMD64
> +#endif
>    }
> -#endif
>  }
>  #endif // !PRODUCT
> 
> 
> But for the missing interpreter_frame_sender_sp_offset I have no idea
> how to fix it.
> 
> I would love to create a ticket in JBS and start working on it,  if the
> cppInterpreter (without zero) should be supported and there is not
> ticket yet.

I believe Zero is the only user of the C++ interpreter at this point.
At least as far as I'm aware of. There is also plans to remove it
entirely. See:
https://bugs.openjdk.java.net/browse/JDK-8074457

Cheers,
Severin