RE: GDB support: Couldn't find method

[Viesturs Veckalns <viesturs dot veckalns at cern dot ch>]

Hello Simon,
It turns out gdb does not know anything about class methods and nested classes loaded from the shared library:

(gdb) ptype GetLevel(resultcode)             
type = struct CompoundHistoUnfolding::Level {
    <incomplete type>
} *
(gdb) ptype CompoundHistoUnfolding::Level         
There is no field named Level

gdb can list members of class CompoundHistoUnfolding but does not know about classes interfaced with the #include directive:

(gdb) ptype CompoundHistoUnfolding       
type = class CompoundHistoUnfolding : public TNamed {
  private:
Python Exception <class 'gdb.error'> No type named TString.: 
    std::map<TString, HistoUnfolding*, std::less<TString>, std::allocator<std::pair<TString const, HistoUnfolding*> > > aggrbackgroundMC;
Python Exception <class 'gdb.error'> No type named HistoUnfolding*.: 
    std::vector<HistoUnfolding*, std::allocator<HistoUnfolding*> > _vbackgroundhistos;
Python Exception <class 'gdb.error'> No type named SampleDescriptor*.: 
    std::vector<SampleDescriptor*, std::allocator<SampleDescriptor*> > _expsyssamples;
    std::vector<SampleDescriptor*, std::allocator<SampleDescriptor*> > _markedsyssamples;
    HistoUnfoldingTH2 *totalbackground;
    char _signal_title[64];
...

How to proceed from this point?
Viesturs
________________________________________
From: Simon Marchi [simon.marchi@polymtl.ca]
Sent: 08 August 2018 02:27
To: Viesturs Veckalns
Cc: gdb@sourceware.org
Subject: Re: GDB support: Couldn't find method

On 2018-08-04 07:48, Viesturs Veckalns wrote:
> Hello!
> I compile a binary by linking a library:
>
> -L${LIBDIR}/lib -lCompoundHisto
>
> In the debug session the library is listed under
>
> info sharedlibrary
>
> Additionally, I requested to read symbols from the relevant source
> files by
>
> set debug-file-directory ${LIBDIR}/interface
> set debug-file-directory ${LIBDIR}/src
>
> Nevertheless, I encounter the following problem:
>
> p GetLevel(resultcode) -> GetHU(mo)
> Couldn't find method CompoundHistoUnfolding::Level::GetHU
>
> The methods are described in the source to build libCompoundHisto.so
>
> What is wrong?
>
> My gdb version is 7.11.
> Viesturs

Hi Viesturs,

A sanity check to see if GDB knows about any GetHU method would to do

   (gdb) ptype GetLevel(resultcode)

or

   (gdb) ptype CompoundHistoUnfolding::Level

Do you see GetHU listed?

Simon