[lldb-dev] Antwort: Re: LLDB fails to load C++ Plugin (sharedlib) - error: this file does not represent a loadable dylib

Mon Jun 11 03:00:58 PDT 2018

Hello,

Thanks to Ted, Pavel and Greg for your reply with suggestion on how to resolve the issue. Greg's comment below help me to resolve the issue. 

>I am guessing that maybe your libModel_LLDB_Debugger.so shared
>library can't find all the dependencies it requires when being
>loaded. Try making a small a.out file that links against this library
>and try to run your a.out program. See if you see any errors when the
>a.out tries to launch.

While I already had an executable linking to the library, I didnot call functions referencing to Clang and XML parsing from the libModel_LLDB_Debugger.so. I simple called a function to print out the size of a map container I have within my lib. Which worked fine. Based on Greg's comment, I then extended this to call more functions which does the XML parsing and AST Parsing, then linking failed with error: undefined reference to `typeinfo for clang::ASTConsumer'. I searched on google and found out that this error has to do with the fact that LLVM and Clang are compiled with -fno-rtti by default and I am not explicitly setting the compile flag -fno-rtti in my project. I then added this to the "ASTConsumer derived class" in my project and it resolved the issue. 

Thanks once more. 

Thanks and Regards,

Bewoayia

-------------
Dipl.- Ing. Bewoayia Kebianyor
Researcher - Hardware/Software Design Methodology Group

OFFIS e.V. - Institut für Informatik
FuE Bereich Verkehr | R&D Division Transportation
Escherweg 2 - 26121 Oldenburg - Germany
Phone/Fax.: +49 441 9722 237/-278
E-Mail: bewoayia.kebianyor at offis.de
URL: http://www.offis.de

-----Greg Clayton <clayborg at gmail.com> schrieb: -----

>An: Bewoayia Kebianyor <Bewoayia.Kebianyor at offis.de>
>Von: Greg Clayton <clayborg at gmail.com>
>Datum: 08.06.2018 18:30
>Kopie: lldb-dev at lists.llvm.org
>Betreff: Re: [lldb-dev] LLDB fails to load C++ Plugin (sharedlib) -
>error: this file does not represent a loadable dylib
>
>Comments inlined below.
>
>
>On Jun 8, 2018, at 2:52 AM, Bewoayia Kebianyor via lldb-dev
><lldb-dev at lists.llvm.org> wrote:
>Hello Everyone,
> 
> I started looking into the LLDB with the intention of adding custom
>commands for my SW debugging purpose. For a better Understanding let
>me explain what I intend to do. I have an source file generated
>automatically from a Model with certain anotations added as comments
>in the code. This code will would be compiled and in error cases
>debugged. When debugging I may have to set breakpoints at certain
>statements in the code based on the anotations incerted by the code
>generator. This is done by specifying the source file and the line
>number. I Use CLANG to get the line number and source file for the
>comments. 
>
>Did you know we have the ability to set breakpoints using source
>regular expression?
>
>(lldb) breakpoint set --source-pattern-regexp "// breakpoint [0-9]+"
>--file /path/to/foo.cpp
>
>This will use a regular expression to search the source file for the
>regular expression you specify and have one breakpoint that has
>multiple locations.
>
> I would like to have custom commands for this and internally map the
>to already existing commands  e.g. "breakpoint set -f -l". I found
>some examples for python, and for c++ I only found the example
>"lldb/examples/plugins/commands/fooplugin.cpp" for writing C++ plugin
>(dynLib) shipped with the LLDB source. In this example adding a new
>commands was straight forward and in the DoExecute function, I call
>the interpreter to handle a breakpoint command. I intend to use C++
>rather than Python.
>
>Do you even need this custom command given what I said above?
> 
> This works fine for a simple shared lib (Simple modification of the
>Example provided in LLDB. In Do execute call interpreter to handle a
>breakpoint command). However if I add other C++ sources which does
>XML parsing, CLANG RecursiveASTVisitor etc to the Library, creating
>the shared library with eclipse is sucessful. I can link the created
>library to an application and it works well. However when I load this
>in lldb with the command ==> plugin load
> "/home/bkebianyor/eclipse-workspace/Model_LLDB_Debugger/Debug/libMod
>el_LLDB_Debugger.so", I get the error message: "error: this file does
>not represent a loadable dylib".
> 
> 
> #Loading the shared lib that is linked just to the liblldb.so -
>SUCESSFUL
> (lldb) 
> (lldb) plugin load
> /home/bkebianyor/eclipse-workspace/DynLib/Debug/libDynLib.so
> (lldb)
> 
> #Loading the shared lib that is linked just to the liblldb.so +
>libxerces-c-3.2.so - FAILS
> 
> (lldb) plugin load
> "/home/bkebianyor/eclipse-workspace/Model_LLDB_Debugger/Debug/libMod
>el_LLDB_Debugger.so"
> error: this file does not represent a loadable dylib
> 
> I have searched for this error on google, but could not find out how
>to resolve this error. Most answers pointed to a mismatch of the lldb
>version in the shared lib to be loaded and that linked to lldb, but
>that is not my case. I am using lldb-5.0.2 and LLVM/CLANG 5.0.2
>toolcahin on Linux 16.04.1-Ubuntu and Eclipse IDE. LLVM was built
>with SHARED_LIBS set to ON.
>
>I am guessing that maybe your libModel_LLDB_Debugger.so shared
>library can't find all the dependencies it requires when being
>loaded. Try making a small a.out file that links against this library
>and try to run your a.out program. See if you see any errors when the
>a.out tries to launch.
>
>Greg
>
> 
> Would be grateful for an answer.
> 
> 
> Thanks and Regards,
> 
> Bewoayia
>
>
>
>
>  
>------------- 
>Dipl.- Ing. Bewoayia Kebianyor
> Researcher - Hardware/Software Design Methodology Group
> 
> OFFIS e.V. - Institut für Informatik
> FuE Bereich Verkehr | R&D Division Transportation
> Escherweg 2 - 26121 Oldenburg - Germany
> Phone/Fax.: +49 441 9722 237/-278
> E-Mail: bewoayia.kebianyor at offis.de
> URL: http://www.offis.de
> 
> Registergericht: Amtsgericht Oldenburg VR 1956
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>techn. Susanne Boll-Westermann, Prof. Dr. Werner Damm, Prof. Dr.-Ing.
>Axel Hahn, Prof. Dr.-Ing. Andreas Hein, Prof. Dr. Sebastian Lehnhoff
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