Building on AIX

[Volker Simonis]

Hi Steve,

sorry to say it, but I'm pretty sure this is yet another XLC bug and
one of the reasons why we are still tied to XLC 10 (which is a
shame!).
I could reproduce the error with a version of XLC 12:

IBM XL C/C++ for AIX, V12.1 (5765-J02, 5725-C72)
Version: 12.01.0000.0000

Unfortunately the 12 compiler is just on a test system where I can't
compile the whole JDK. But I could narrow the problem down to the
following little, self contained C++ program (based on the original
HotSpot sources):

/////////////////////////////////////////////private.cpp////////////////////////////////////////////////////////
class FOO {
 public:
  ~FOO() {}
};

class StackObj {
 public:
  void  operator delete(void* p) {}
};

class MethodHandleWalker : StackObj {
  FOO foo;
};

class MethodHandleCompiler : public MethodHandleWalker {
};

int main(int argc, char* argv[]) {

  {
    MethodHandleCompiler mh;
  }

  return 1;
}
/////////////////////////////////////////////private.cpp////////////////////////////////////////////////////////

If compiled with XLC 12, it provokes the very same error message:

> xlC_r -q64 -c -o /tmp/a.out ~/Bugs/xlC/private.cpp
"/sapmnt/home1/d046063/Bugs/xlC/private.cpp", line 11.28: 1540-0198
(W) The omitted keyword "private" is assumed for base class
"StackObj".
"/sapmnt/home1/d046063/Bugs/xlC/private.cpp", line 6.7: 1540-0300 (S)
The "private" member "class StackObj" cannot be accessed.
"/sapmnt/home1/d046063/Bugs/xlC/private.cpp", line 15.7: 1540-0719 (I)
The previous message was produced while processing the implicit member
function "MethodHandleCompiler::~MethodHandleCompiler()".
"/sapmnt/home1/d046063/Bugs/xlC/private.cpp", line 18.5: 1540-0700 (I)
The previous message was produced while processing "main(int, char
*[])".

This code works with all other compilers we know (at least  XLC 10,
GCC 4, MS Visual Studio, HP aCC, Sun Studio) an I'm pretty sure that
XLC 12 is wrong.
The problem is that XLC claims that the "StackObj" class is not
accessible from within the synthetically generated destructor of the
class "MethodHandleCompiler". That is true, because "StackObj" is a
private base class "MethodHandleWalker" from which
"MethodHandleCompiler" inherits.

But that's not the point here! The synthetically generated destructor
of the class "MethodHandleCompiler" (i.e.
"MethodHandleCompiler::~MethodHandleCompiler()") only has to destruct
the members of "MethodHandleCompiler" and call the destructor of its
base classes. And in turn, the synthetically generated destructor of
its base class "MethodHandleWalker" could access its base class
"StackObj" very well!

We would be really deeply grateful if you could escalate this bug to
your internal XLC compiler group colleagues. After all, the HotSpot
code is more than 10 years old C++ code which doesn't  use neither
Exception Handling nor RTTI and only some very simple template
constructs and I think this code should be correctly compilable by
every reasonably decent C++ compiler nowadays.

After all, your XLC team can freely access and build the OpenJDK
sources so it should be not too hard for them to reproduce this and
maybe other problems.

Regards,
Volker


On Mon, Nov 12, 2012 at 11:38 AM, Steve Poole <spoole at linux.vnet.ibm.com> wrote:
> hi guys.   The build instructions from Volker seem to work ok on my AIX   machine up to a point.
>
> Using V11 of the XLC compiler I hit a compiler bug.   When I move to the latest V12 version I get this below in the build log..
>
> Seems to be a pretty hard failure -  any advice?
>
> Cheers Steve
>
>
> Compiling /home/spoole/repos/aix-ppc/jdk7u/hotspot/src/share/vm/ci/ciObject.cpp
> rm -f ciObject.o
> xlC_r -DAIX -DPPC64 -DASSERT -DDEBUG  -I/home/spoole/repos/aix-ppc/jdk7u/hotspot/src/share/vm/prims -I/home/spoole/repos/aix-ppc/jdk7u/hotspot/src/share/vm -I/home/spoole/repos/aix-ppc/jdk7u/hotspot/src/share/vm/precompiled -I/home/spoole/repos/aix-ppc/jdk7u/hotspot/src/cpu/ppc/vm -I/home/spoole/repos/aix-ppc/jdk7u/hotspot/src/os_cpu/aix_ppc/vm -I/home/spoole/repos/aix-ppc/jdk7u/hotspot/src/os/aix/vm -I/home/spoole/repos/aix-ppc/jdk7u/hotspot/src/os/posix/vm -I../generated -DHOTSPOT_RELEASE_VERSION="\"23.2-b04\"" -DHOTSPOT_BUILD_TARGET="\"jvmg\"" -DHOTSPOT_BUILD_USER="\"spoole\"" -DHOTSPOT_LIB_ARCH=\"ppc64\" -DHOTSPOT_VM_DISTRO="\"OpenJDK\"" -DTARGET_OS_FAMILY_aix -DTARGET_ARCH_ppc -DTARGET_ARCH_MODEL_ppc_64 -DTARGET_OS_ARCH_aix_ppc -DTARGET_OS_ARCH_MODEL_aix_ppc_64 -DTARGET_COMPILER_xlc -qpic=large -qnortti -qnoeh -D_REENTRANT -q64 -DCC_INTERP -g -q64 -qlanglvl=c99vla -qlanglvl=noredefmac -qsuppress=1540-0198 -qsuppress=1540-1090 -qsuppress=1500-010 -DSAFEFETCH_STUBS -DINCLUDE_TRACE      -c -qmakedep=gcc -MF ../generated/dependencies/ciObject.o.d -o ciObject.o /home/spoole/repos/aix-ppc/jdk7u/hotspot/src/share/vm/ci/ciObject.cpp
> "/home/spoole/repos/aix-ppc/jdk7u/hotspot/src/share/vm/memory/allocation.hpp", line 112.7: 1540-0300 (S) The "private" member "class StackObj" cannot be accessed.
> "/home/spoole/repos/aix-ppc/jdk7u/hotspot/src/share/vm/prims/methodHandleWalk.hpp", line 272.7: 1540-0719 (I) The previous message was produced while processing the implicit member function "MethodHandleCompiler::~MethodHandleCompiler()".
> "/home/spoole/repos/aix-ppc/jdk7u/hotspot/src/share/vm/ci/ciMethodHandle.cpp", line 69.3: 1540-0700 (I) The previous message was produced while processing "ciMethodHandle::get_adapter_impl(bool)".
>