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

[Dmitry Samersoff]

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?

-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 ...