How to use gdb to debug C1 compiler's internal error?

[Leslie Zhai]

Hi Thomas,

Thanks for your response!


在 2018年03月26日 19:20, Thomas Stüfe 写道:
>
>
> On Mon, Mar 26, 2018 at 11:48 AM, Andrew Haley <aph at redhat.com 
> <mailto:aph at redhat.com>> wrote:
>
>     On 03/22/2018 04:32 PM, Leslie Zhai wrote:
>     > So backtrace or set breakpoint might be helpful for debugging
>     compiling
>     > thread, but doesn't work for running thread? I am reading
>     Analyzing and
>     > Debugging the HotSpot VM at the OS Level[1] please give me some
>     advice,
>     > thanks a lot!
>     >
>     > [1]
>     http://www.progdoc.de/papers/JavaOne2014/javaone2014_con3138.html
>     <http://www.progdoc.de/papers/JavaOne2014/javaone2014_con3138.html>
>
>     You'll first need to set a breakpoint in the segfault handler here in
>     JVM_handle_linux_signal:
>
>       VMError::report_and_die(t, sig, pc, info, ucVoid);
>
>     Then you can use gdb to go up the stack to the point of the crash.
>
>     At that point you'll be inspecting the stack to see what's there.  If
>     you can't tell, then your next plan should be to instrument the code
>     you're generating to add tracing information so that when it does, you
>     know where you are.
>
>
> small addition, until you hit the breakpoint at 
> VMError::report_and_die() gdb may trip over any number of SIGSEGV or 
> SIGBUS. That is usually normal, since signals are also used internally 
> for non-error purposes. Just continue until you hit 
> VMError::report_and_die(), which when you hit it indicates a real 
> error. Or, set the SIGSEGV handler to nostop.

Yes, Fedora's wiki mentions that 
https://fedoraproject.org/wiki/Java/StackTraces
And I am able to discover the normal SIGSEGV or SIGBUS with my eyes now :P

Thread 2 "java" received signal SIGSEGV, Segmentation fault.
0x00007fffd8f5319c in ?? ()


>
> Best Regards, Thomas
>
>     --
>     Andrew Haley
>     Java Platform Lead Engineer
>     Red Hat UK Ltd. <https://www.redhat.com>
>     EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671
>
>

-- 
Regards,
Leslie Zhai