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

[Zhengyu Gu]

Thanks for reviewing, Yumin.

-Zhengyu

On 03/14/2018 12:16 AM, yumin qi wrote:
> It looks good  though the resource mark is too far before second 
> NEW_RESOUCE_ARRAY which leads me to think there is a problem(No problem!).
> 
> Thanks
> Yumin
> 
> On Thu, Mar 8, 2018 at 8:12 AM, Zhengyu Gu <zgu at redhat.com 
> <mailto:zgu at redhat.com>> wrote:
> 
>     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
>                 <https://bugs.openjdk.java.net/browse/JDK-8193318>
>                 Webrev:
>                 http://cr.openjdk.java.net/~zgu/8193318/webrev.00/
>                 <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
> 
>