RFR: 8002034 and 8001756 - FDS changes mainly re cross-compiling

[Dmitry Samersoff]

David,

OK. Thank you for the explanation!

-Dmitry

On 2012-11-04 13:45, David Holmes wrote:
> On 3/11/2012 2:17 AM, Dmitry Samersoff wrote:
>> David,
>>
>> Other projects e.g. linux kernel sets CROSS_COMPILE, to specify the
>> prefix for all executables used during compilation.
>>
>> e.g.
>>    make CROSS_COMPILE=ia64-linux-
>>
>> will cause
>>      CC=ia64-linux-gcc
>>      OBJCOPY=ia64-linux-objcopy
>> etc
>>
>> Could we adopt this convention?
> 
> The new build handles cross-compilation more like the above, but hotspot
> makefiles have not been re-written in this way. Regardless that is a
> project way beyond the scope of this CR which requires that we get FDS
> enabled for 7u12 (and hence first in 8).
> 
> David
> 
> 
>> -Dmitry
>>
>>
>> On 2012-11-02 06:39, David Holmes wrote:
>>> On 2/11/2012 12:03 PM, BILL PITTORE wrote:
>>>> On 11/1/2012 7:47 PM, David Holmes wrote:
>>>>> On 2/11/2012 8:49 AM, Dmitry Samersoff wrote:
>>>>>> David,
>>>>>>
>>>>>> Sorry, (my eyes) I misread if
>>>>>>
>>>>>> As far as I understand, cross compilation require explicit
>>>>>> ALT_OBJCOPY.
>>>>>
>>>>> Yes.
>>>>>
>>>>>> Is there any defaults?
>>>>>
>>>>> No. The makefiles know nothing about the toolsets for cross-compiling.
>>>> We set CC, CPP, CXX using COMPILER_PATH which gets us to the cross
>>>> tools, why not go for OBJCOPY as well? It may or may not exist. Is that
>>>> worse than the current situation?
>>>
>>> Fair point, we could just assume that when cross-compiling we find
>>> objcopy in the same place as gcc etc.
>>>
>>> Thanks,
>>> David
>>>
>>>
>>>> bill
>>>>
>>>>>
>>>>>> Does it make sense to warn if ALT_OBJCOPY isn't set?
>>>>>
>>>>> The build already reports:
>>>>>
>>>>> INFO: ENABLE_FULL_DEBUG_SYMBOLS=1
>>>>> INFO: no objcopy cmd found so cannot create .debuginfo files.
>>>>> INFO: ENABLE_FULL_DEBUG_SYMBOLS=0
>>>>>
>>>>> I could extend that to say:
>>>>>
>>>>> INFO: ENABLE_FULL_DEBUG_SYMBOLS=1
>>>>> INFO: no objcopy cmd found so cannot create .debuginfo files. You may
>>>>> need to set ALT_OBJCOPY.
>>>>> INFO: ENABLE_FULL_DEBUG_SYMBOLS=0
>>>>>
>>>>> Thanks,
>>>>> David
>>>>>>
>>>>>> -Dmitry
>>>>>>
>>>>>> On 2012-11-02 02:15, David Holmes wrote:
>>>>>>> Thanks for the review Dmitry.
>>>>>>>
>>>>>>> On 1/11/2012 10:02 PM, Dmitry Samersoff wrote:
>>>>>>>> David,s
>>>>>>>>
>>>>>>>> if we use host /usr/bin/objcopy for cross compiling,
>>>>>>>> changes looks good for me.
>>>>>>>
>>>>>>> ??? We don't use host /usr/bin/objcopy for cross-compiling that
>>>>>>> is why
>>>>>>> DEF_OBJCOPY is only set when not cross-compiling.
>>>>>>>
>>>>>>> Of course you can set ALT_OBJCOPY=/usr/bin/objcopy when
>>>>>>> cross-compiling.
>>>>>>> It probably won't work but you can do it.
>>>>>>>
>>>>>>> David
>>>>>>>
>>>>>>>> -Dmitry
>>>>>>>>
>>>>>>>> On 2012-11-01 07:41, David Holmes wrote:
>>>>>>>>> No takers so far - don't be shy, it's not a difficult one I
>>>>>>>>> promise :)
>>>>>>>>>
>>>>>>>>> Updated webrev:
>>>>>>>>> http://cr.openjdk.java.net/~dholmes/8002034/webrev.01/
>>>>>>>>>
>>>>>>>>> Because of the multiple sub-make invocations that occur during a
>>>>>>>>> build
>>>>>>>>> the FDS logic gets processed numerous times, many of which are not
>>>>>>>>> needed and which might show confusing output (eg that FDS is
>>>>>>>>> enabled
>>>>>>>>> when you have disabled it). So I added another conditional to at
>>>>>>>>> least
>>>>>>>>> check that BUILD_FLAVOR has been set - that excludes a couple
>>>>>>>>> of the
>>>>>>>>> unnecessary executions.
>>>>>>>>>
>>>>>>>>> Thanks,
>>>>>>>>> David
>>>>>>>>>
>>>>>>>>> On 31/10/2012 5:29 PM, David Holmes wrote:
>>>>>>>>>> http://cr.openjdk.java.net/~dholmes/8002034/webrev/
>>>>>>>>>>
>>>>>>>>>> This mainly addresses
>>>>>>>>>>
>>>>>>>>>> JDK-8002034 Allow Full Debug Symbols when cross-compiling
>>>>>>>>>>
>>>>>>>>>> The initial FDS work simply disables FDS when
>>>>>>>>>> cross-compilation is
>>>>>>>>>> involved. But we're now ready to deal with the cross-compilation
>>>>>>>>>> case
>>>>>>>>>> (and even if we weren't these changes would be fine anyway). So
>>>>>>>>>> if FDS
>>>>>>>>>> is initially enabled we will rely on ALT_OBJCOPY being set to the
>>>>>>>>>> correct value for cross-compilation; and we don't set the default
>>>>>>>>>> OBJCOPY in that case. So if you do nothing when cross-compiling
>>>>>>>>>> OBJCOPY
>>>>>>>>>> will be empty and that will cause the build to disable FDS, just
>>>>>>>>>> as if
>>>>>>>>>> the OBJCOPY command was not found.
>>>>>>>>>>
>>>>>>>>>> As this is the same code that causes:
>>>>>>>>>>
>>>>>>>>>> JDK-8001756 Hotspot makefiles report missing OBJCOPY command
>>>>>>>>>> in the
>>>>>>>>>> wrong circumstances
>>>>>>>>>>
>>>>>>>>>> I also fixed this by moving the OBJCOPY checks inside the
>>>>>>>>>> ENABLE_FULL_DEBUG_SYMBOLS=1 conditional. Basically unless we are
>>>>>>>>>> asking
>>>>>>>>>> for FDS we shouldn't complain if the OBJCOPY command is not
>>>>>>>>>> found.
>>>>>>>>>>
>>>>>>>>>> This will be pushed to the hotspot-emb repo as it is needed there
>>>>>>>>>> ASAP.
>>>>>>>>>>
>>>>>>>>>> I'll be doing a similar change, under 8002040, for the JDK
>>>>>>>>>> side of
>>>>>>>>>> things.
>>>>>>>>>>
>>>>>>>>>> Thanks,
>>>>>>>>>> David
>>>>>>>>
>>>>>>>>
>>>>>>
>>>>>>
>>>>
>>
>>


-- 
Dmitry Samersoff
Java development team, SPB04
* There will come soft rains ...