Re: 5.2 rc2 tarball now available

[Daniel J S. <dan...@ie...>]

On 07/04/2017 08:07 PM, Daniel J Sebald wrote:
> On 07/04/2017 06:23 PM, sfeam via gnuplot-beta wrote:
>> On Wednesday, 05 July 2017 01:08:35 Petr Mikulik wrote:
>>>>> I have troubles compiling rc2 on Linux (OpenSUSE 42.2, and some
>>>>> Ubuntu) -
>>>>> linking fails.
>>>>>
>>>>> It is this problem:
>>>>>      https://sourceforge.net/p/gnuplot/support-requests/196/
>>>>>
>>>>> The workaround
>>>>>      configure --with-X11
>>>>> described above does not help, while
>>>>>      TERMLIBS="-lX11" ./configure
>>>>> let me gnuplot compile.
>>>>>
>>>>> Can this be fixed?
>>>>
>>>>   No.  It is a bug in the configuration files distributed for libwxgtk.
>>>
>>> Unfortunately it seems to be a wide-spread bug. It is quite
>>> embarassing that a
>>> compile needs googling to fix it locally.
>>>
>>> Cannot "./configure" take care of this? I.e. add the "-lX11" flag if
>>> "something"?
>>
>> That "something" is exactly the problem.   Only some versions of
>> wxWidgets need this, and only for some configurations.   The
>> wx-config tool is supposed to tell us what libraries are needed so
>> we can link them.  But it doesn't mention X11.    So how are we to know?
>
> Actually, I think this is gnuplot's responsibility.  If I do
>
> sebald@ ~ $ wx-config --libs
> -L/usr/lib/x86_64-linux-gnu -pthread   -lwx_gtk2u_xrc-3.0
> -lwx_gtk2u_html-3.0 -lwx_gtk2u_qa-3.0 -lwx_gtk2u_adv-3.0
> -lwx_gtk2u_core-3.0 -lwx_baseu_xml-3.0 -lwx_baseu_net-3.0 -lwx_baseu-3.0
>
> in that list is "pthread" which I believe is to inform the gcc/c++
> compiler that posix threads are to be used in compiling and linking.  (I
> think pthread is standard across compilers, but I'm not sure.)  In other
> words, it's supposed to be the responsibility of the compiler to deal
> with all the threads issues so long as wxWidgets follows posix.
>
> In the fix for this bug
>
> http://gnuplot.10905.n7.nabble.com/crash-when-using-wxt-in-Ubuntu-12-04-td17318.html
>
>
> the following line was added:
>
> /* Define a new application type, each gui should derive a class from
> wxApp */
> class wxtApp : public wxApp
> {
> public:
> #if defined(WXT_MULTITHREADED) && defined(WX_NEEDS_XINITTHREADS) &&
> defined(X11)
>     /* Magic fix needed by wxgtk3.0 */
>         wxtApp() : wxApp() { XInitThreads(); }
> #endif

I'm not having any problems building/running if I just comment out this 
line.  Then again, from my wx-config test, I might be using GTK2 rather 
than GTK3, which might be the issue if "wxgtk3.0" is in the comment.

This looks to have been a thread from 2013.  Maybe we should open a bug 
report and move the discussion there in hopes of finding someone for 
which that crash can be replicated when there is no XInitThreads().

Dan