RFR(S) 8134898: Small fixes found during JVMCI work

[Vladimir Kozlov]

 > To resolve the incompatibility, you can simply remove
 > CHECK_UNHANDLED_OOPS around the field in Thread, and put it under
 > #ifndef PRODUCT.

Wonderful! :) I thought it requires #ifdef CHECK_UNHANDLED_OOPS.

Please, look on new changes:

http://cr.openjdk.java.net/~kvn/8134898/webrev.01/

Thanks,
Vladimir

On 9/1/15 8:55 PM, Coleen Phillimore wrote:
>
>
> On 9/1/15 7:59 PM, Vladimir Kozlov wrote:
>> http://cr.openjdk.java.net/~kvn/8134898/webrev/
>> https://bugs.openjdk.java.net/browse/JDK-8134898
>>
>> During review of JVMCI changes we were asked to push not related small
>> changes separately.
>>
>> Removed jre/ from jdk paths in makefiles since jdk9 does not have it
>> anymore.
>> Solaris vm.make and buildtree.make missed changes other unix platforms
>> have.
>> Fix type in doc.
>> Added -DCHECK_UNHANDLED_OOPS to debug build. I very strongly want to
>> do that.
> Adding -DCHECK_UNHANDLED_OOPS to the debug build adds a level of
> indirection to the oops that are somewhat annoying during debugging:
>
> eg.
>
> 692    void java_lang_Class::set_component_mirror(oop java_class, oop
> comp_mirror) {
> 693      assert(_component_mirror_offset != 0, "must be set");
> 694        java_class->obj_field_put(_component_mirror_offset,
> comp_mirror);
> 695      }
>
> (gdb) print java_class
> $7 = {_o = 0x8cb003b8}
> (gdb) print java_mirror
> No symbol "java_mirror" in current context.
> (gdb) print comp_mirror
> $8 = {_o = 0x8cb001b0}
> (gdb) call hsfind(java_class._o)
> warning: Using non-standard conversion to match function hsfind to
> supplied arguments
>
> "Executing hsfind"
> 0x000000008cb003b8 is an oop
> java.lang.Class
>   - klass: 'java/lang/Class'
>   - ---- fields (total size 13 words):
> ...
>
>
> vs.
>
> 693      assert(_component_mirror_offset != 0, "must be set");
> (gdb) print java_class
> $1 = (oop) 0x8cb003b8
> (gdb) print comp_mirror
> $2 = (oop) 0x8cb001b0
> (gdb) print hsfind(java_class)
> warning: Using non-standard conversion to match function hsfind to
> supplied arguments
>
> "Executing hsfind"
> 0x000000008cb003b8 is an oop
> java.lang.Class
>   - klass: 'java/lang/Class'
>   - ---- fields (total size 13 words):
> ...
>
>
> The GC people deal with far more 'oop' objects in their debugging, which
> is why they asked me originally not to enable CHECK_UNHANDLED_OOPS in
> the debug build.
>
> To resolve the incompatibility, you can simply remove
> CHECK_UNHANDLED_OOPS around the field in Thread, and put it under
> #ifndef PRODUCT.
>
> Coleen
>> It is the only incompatibility in memory layout between fastdebug and
>> debug VM. We maintained such compatibility for long time and it was
>> broken with 7195622 changes.
>> For AOT project it is very important to keep compatibility because we
>> use fastdebug VM for JAOTC tool to compile aot code and we want to be
>> able use debug VM to debug execution of aot code.
>> Note, using debug VM with JAOTC will take 5-10 times longer to compile.
>>
>> Thanks,
>> Vladimir
>