RFR(S) 8193318: ELF decoder should be able to use external debug info file

[Zhengyu Gu]

Ping! I can get formal review?

Thanks,

-Zhengyu


On 02/23/2018 12:26 PM, Zhengyu Gu wrote:
> Thanks, Aleksey.
> 
> On 02/23/2018 12:01 PM, Aleksey Shipilev wrote:
>> On 02/15/2018 06:59 PM, Zhengyu Gu wrote:
>>> This Linux only patch allows OpenJDK Linux distributions, which strip 
>>> out debug symbols in
>>> production bundles, to use external debuginfo bundles, if present, to 
>>> decode stacks.
>>>
>>> The implementation mirrors SA implementation [1][2]. It has minimal 
>>> impact to Oracle's JDK, which
>>> always contains symbol tables.
>>>
>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8193318
>>> Webrev: http://cr.openjdk.java.net/~zgu/8193318/webrev.00/
>>
>> Looks OK on my untrained eye.
>>
>> *) I am wondering if we can merge the existing implementation in
>> src/jdk.hotspot.agent/linux/native/libsaproc/symtab.c and this mirror 
>> implementation in
>> src/hotspot/os/linux/decoder_linux.cpp? Notably, moving 
>> gnu_debuglink_crc32 to some shared file
>> would trim down the change.
> 
> Yes, but I don't know if there is a way.
> 
>>
>> Andrew Haley knows this better, as he is the author of the related 
>> change.
> 
> Cc'ed Andrew Haley.
> 
> -Zhengyu
> 
> 
> 
>>
>> Thanks,
>> -Aleksey
>>