C++ symbols in jhsdb jstack --mixed

[David Holmes]

Hi Yasumasa,

New build dependencies cannot be added lightly. This impacts everyone 
who maintains build/test farms.

We already use the C++ demangling capabilities in the VM. Is there some 
way to export that for use by libsaproc ?

Otherwise using C++ demangle may still be the better choice given we 
already have it as a dependency.

David

On 1/11/2019 12:58 am, Chris Plummer wrote:
> Hi Yasumasa,
> 
> Here's the failure during configure:
> 
> [2019-10-31T06:07:45,131Z] checking demangle.h usability... no
> [2019-10-31T06:07:45,150Z] checking demangle.h presence... no
> [2019-10-31T06:07:45,150Z] checking for demangle.h... no
> [2019-10-31T06:07:45,151Z] configure: error: Could not find demangle.h! 
> You might be able to fix this by running 'sudo yum install binutils-devel'.
> 
> Chris
> 
> 
> On 10/31/19 1:08 AM, Yasumasa Suenaga wrote:
>> Hi,
>>
>> I filed this enhancement to JBS:
>>
>>   https://bugs.openjdk.java.net/browse/JDK-8233285
>>
>> Also I pushed the changes to submit repo, but it was failed.
>>
>>   http://hg.openjdk.java.net/jdk/submit/rev/bfbc49233c26
>>   http://hg.openjdk.java.net/jdk/submit/rev/430e4f65ef25
>>
>> According to the email from Mach 5, dependency errors were occurred in 
>> jib.
>> Can someone share the details?
>> I'm not familiar in jib, so I want help.
>>
>>   mach5-one-ysuenaga-JDK-8233285-20191031-0606-6301426
>>
>>
>> Thanks,
>>
>> Yasumasa
>>
>>
>> On 2019/10/31 11:23, Chris Plummer wrote:
>>> You can change the configure script. I don't know if there's any 
>>> concerns with using libiberty.a. That's possibly a legal question 
>>> (GNU GPL). You might want to ask that on jdk-dev and/or build-dev.
>>>
>>> Chris
>>>
>>> On 10/30/19 7:14 PM, Yasumasa Suenaga wrote:
>>>> Hi Chris,
>>>>
>>>> Thanks for quick reply!
>>>>
>>>> If we convert LinuxDebuggerLocal.c to C++ code, we have to convert a 
>>>> lot of JNI calls to C++ style.
>>>> For example:
>>>>
>>>>   (*env)->FindClass(env, "java/lang/String")
>>>>       to
>>>>   env->FindClass("java/lang/String")
>>>>
>>>> Can it be accepted?
>>>>
>>>> OTOH I said in my email, to use cplus_demangle(), we need to link 
>>>> libiberty.a which is provided by binutils. Thus I think we need to 
>>>> check libiberty.a in configure script. Is it ok?
>>>>
>>>>
>>>> I prefer to use cplus_demangle() if we can change configure script.
>>>>
>>>>
>>>> Yasumasa
>>>>
>>>>
>>>> On 2019/10/31 11:03, Chris Plummer wrote:
>>>>> Hi Yasumasa,
>>>>>
>>>>> I don't have concerns with adding C++ source to SA, but in order to 
>>>>> do so you've put the new native code in its own file rather than in 
>>>>> LinuxDebuggerLocal.c. I'd like to see that resolved. So either 
>>>>> convert LinuxDebuggerLocal.c to C++, or use cplus_demangle().
>>>>>
>>>>> thanks,
>>>>>
>>>>> Chris
>>>>>
>>>>> On 10/30/19 6:54 PM, Yasumasa Suenaga wrote:
>>>>>> Hi all,
>>>>>>
>>>>>> I saw C++ frames in `jhsdb jstack --mixed`, and they were mangled 
>>>>>> as below:
>>>>>>
>>>>>>
>>>>>> 0x00007ff255a8fa4c 
>>>>>> _ZN9JavaCalls11call_helperEP9JavaValueRK12methodHandleP17JavaCallArgumentsP6Thread 
>>>>>> + 0x6ac
>>>>>> 0x00007ff255a8cc1d 
>>>>>> _ZN9JavaCalls12call_virtualEP9JavaValueP5KlassP6SymbolS5_P17JavaCallArgumentsP6Thread 
>>>>>> + 0x33d
>>>>>>
>>>>>>
>>>>>> We can demangle them via c++filt, but I think it is more 
>>>>>> convenience if jstack can show demangling symbols.
>>>>>> I think we can demangle in jstack with this patch. If it is 
>>>>>> accepted, I will file it to JBS and send review request.
>>>>>> What do you think?
>>>>>>
>>>>>>   http://cr.openjdk.java.net/~ysuenaga/sa-demangle/
>>>>>>
>>>>>> We can get the stack as below after applying this patch:
>>>>>>
>>>>>>
>>>>>> 0x00007ff1aba20a4c      JavaCalls::call_helper(JavaValue*, 
>>>>>> methodHandle const&, JavaCallArguments*, Thread*) + 0x6ac
>>>>>> 0x00007ff1aba1dc1d JavaCalls::call_virtual(JavaValue*, Klass*, 
>>>>>> Symbol*, Symbol*, JavaCallArguments*, Thread*) + 0x33d
>>>>>>
>>>>>>
>>>>>> I use abi::__cxa_demangle() for demangling, so this patch adds C++ 
>>>>>> source to SA.
>>>>>> If it is not comfortable, we can use cplus_demangle().
>>>>>> But this function is provided by libiberty.a, so we need to link 
>>>>>> it to libsaproc and need to check libiberty.a in configure script.
>>>>>>
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> Yasumasa
>>>>>
>>>>>
>>>
>>>
> 
>