[gentoo-user] Re: [OFF TOPIC] Qt Creator unable to access containers in debug mode

[Nikos Chantziaras <realnc@gmail.com>]

Note that gdb cannot inspect containers. It doesn't know anything about 
them.

Qt Creator uses "debugging helpers" for that. See:

   https://qt-project.org/doc/qtcreator-2.8/creator-debugging-helpers.html

Since you're using a deprecated version of Creator (2.8 is from 2013 and 
not maintained anymore), those helpers are probably not updated for new 
gdb versions.

If you don't want to upgrade Creator through portage, you could instead 
use the binary Qt Creator installer, and simply install it in your home 
directory (I did that in the past, before Qt5 was put in ~arch.)


On 24/03/15 22:43, Francisco Ares wrote:
> Thank you all for those clues, pretty interesting.
>
> For now I suppose it is a gdb thing, as QtCreator is able to show
> details about STL containers as expected.
>
> Going to fiddle in gdb a bit more...
>
>
> 2015-03-24 17:07 GMT-03:00 Fernando Rodriguez
> <frodriguez.developer@outlook.com
> <mailto:frodriguez.developer@outlook.com>>:
>
>     On Tuesday, March 24, 2015 9:32:07 PM Nikos Chantziaras wrote:
>      > On 24/03/15 21:12, Fernando Rodriguez wrote:
>      > > On Tuesday, March 24, 2015 10:07:56 AM Francisco Ares wrote:
>      > >> Hi,
>      > >>
>      > >> Recently - but can't figure out exactly when - Qt Creator has
>     become
>     unable
>      > >> to access Qt containers (where the STL ones work as expected)
>     on the
>     debug
>      > >> panel.  It shows <not accessible> in place of the expected
>     item quantity
>      > >> for a QList, for instance, but for a std::vector<std::string>,
>     it works,
>      > >> allowing inspection of all items.
>      > >>
>      > >> Any hints on what I may be doing wrong? The headers are all
>     accessible,
>     for
>      > >> instance. Should I build Qt with debug symbols enabled, as
>     recommended
>     for
>      > >> glibc?
>      > >>
>      > >> Using current Qt 4.8.5, Qt Creator 2.8.1, gdb 7.7.1, gcc 4.8.3
>      > >>
>      > >> Thanks!
>      > >> Francisco
>      > >
>      > > Try to print it from gdb cli, if it works you'll know the issue
>     QtCreator,
>      > > otherwise you're likely missing some symbols. You should always
>     compile
>     any
>      > > development libraries with debug symbols.
>      >
>      > You don't need debug symbols for inspecting containers. They are not
>      > needed. The only reason for enabling debug symbols in Qt is if
>     you want
>      > to step into Qt's code.
>
>     Thank you. You do need symbols though, just not Qts for this
>     specific case.
>     There are many reasons why you should compile your development
>     libraries with
>     symbols besides stepping into the code. Such as getting a backtrace.
>     Even
>     proprietary (closed-source) libraries often make the symbols
>     available for
>     this reason.