Debugin Hotspot VM in Netbeans - Ubuntu Linux 14

[Volker Simonis]

Hi Marcelino,

if you are using a recent clone of jdk9 you have to replace
--disable-zip-debug-info with --with-native-debug-symbols=external
during configure (there's a warning line at the end of configure which
warns you about --disable-zip-debug-info being ignored, but it can be
easily overlooked).

Without --with-native-debug-symbols=external the debug info will be in
libjvm.diz and gdb can not find the line number and symbol
information. Unzipping libjvm.diz (in-place) will give you
libjvm.debuginfo which will be automatically loaded by gdb if it is
located in the same directory like libjvm.so.

Regards,
Volker



On Wed, Feb 17, 2016 at 2:53 PM, Marcelino Rodriguez cancio
<marcelino.rodriguez-cancio at irisa.fr> wrote:
> Hello all,
>
> I'm trying to debug the with OpenJDK9 Hotspot in Linux Ubuntu 14 using Netbeans.
>
> My problem is that the gdb debugger, which I launch from the IDE, don't stop in certain breakpoints, specifically in :
> /9dev/hotspot/src/share/vm/opto/loopPredicate.cpp/loopPredicate.cpp:909
>
> I'm able to launch the compiler and stop in: /9dev/jdk/src/java.base/share/native/libjli/java.cjava.c:1138, for example.
>
> I believe this happens because gdb does not attach to the VM thread, which seems to me is a child thread, only the parent launched from the Java executable (images/jdk/java).
>
> I'm total newby to gdb and I would like to debug from the IDE if possible. Any hints, leads or advice on this?
>
>
>
>
> My SETUP is as Follows:
>
> I can see that the code containing the breakpoint is executed looking at the trace of the Hotspot (I'm using -XX:+TraceLoopPredicate ):
> rc_predicate init <u range
> lower bound check if: 475
> rc_predicate (limit - stride) <u range
> upper bound check if: 475
> Loop Predication Performed: Loop: N467/N273 limit_check predicated counted [int,int),+1 (-1 iters) has_sfpt rce
> rc_predicate init <u range
> lower bound check if: 200
> rc_predicate (limit - stride) <u range
> upper bound check if: 200
> Loop Predication Performed: Loop: N198/N184 limit_check predicated counted [int,int),+1 (-1 iters) has_sfpt rce
> no main manifest attribute, in /home/elmarce/PROJECTS/PHD/predicateloop/target/predicateloop-1.0-SNAPSHOT.jar
>
> I have described the way I compiled OpenJDK in here:
> http://marcelinorc.com/2016/02/11/compiling-openjdk-9/
>
> And the way I created the Netbeans project in here:
> http://marcelinorc.com/2016/02/17/using-netbeans-to-hack-openjdk9-in-ubuntu/
>
> I have configurated the compilation with the flags:
> --with-debug-level=slowdebug --with-target-bits=64 --disable-zip-debug-info
>
> I'm using as build result: build/linux-x86_64-normal-server-slowdebug/jdk/bin/java
>
> And as Run Command: "${OUTPUT_PATH}" -XX:+TraceLoopPredicate -jar /path/to/file/predicateloop-1.0-SNAPSHOT.jar
>
>
>
> I have read the post by Simonis:
> https://community.oracle.com/blogs/simonis/2008/01/24/hotspot-development-linux-netbeans-part-2#NB_Debug
>
> And then Watched the video:
> https://www.youtube.com/watch?v=k7IX_diKCEo
>
>
>
> Thanks
> Marcelino