Re: [Plplot-devel] Problem with wxWidgets under MinGW-w64/MSYS2

[Alan W. I. <ir...@be...>]

On 2017-06-23 11:12-0000 Arjen Markus wrote:

> Hi Alan,
>
>
>
>> -----Original Message-----
>> From: Alan W. Irwin [mailto:ir...@be...]
>> Sent: Friday, June 23, 2017 1:04 PM
>>
>> Hi Arjen:
>>
>> Thanks very much for that quick turnaround.
>>
> You're welcome :)
>
>>> I get compile errors as can be seen in the attached tarball (output
>> from CMake and make, as well as the config header file). We need to sort out these
>> things before a comprehensive build is going to stand any chance.
>>
>> From what I can tell from your current extremely limited make.out (please generate
>> that next time with VERBOSE=1), it looks like these build issues have nothing to do
>> with PLplot code and instead are wxwidgets header incompatibilities _for the
>> compile flags that are being generated by your current  Unix wxwidgets find
>> method_.
>>
>> Therefore, I am pretty sure the current build issue is caused by your build using
>> Unix wxwidgets compile and link flags when it should be using Windows wxwidgets
>> compile and link flags for the MinGW-w64/MSYS2 platform. So to get access to the
>> latter flags, I suggest you use the _Windows_ wxwidgets find method (which I
>> understand you automatically obtain if you use the "MSYS Makefiles" generator.)
>>
>
> I do not think so, the condition definitely says "AND NOT MSYS" - so that would use the Unix method.

You are right.  So without your one-line change to
FindwxWidgets.cmake, the "Unix Makefiles" generator or "MinGW
Makefiles" generator will yield

set(wxWidgets_FIND_STYLE "win32")

while (confusing) the "MSYS Makefiles" generator will yield

set(wxWidgets_FIND_STYLE "unix")

>
>> If I have understood correctly what you said before, the Windows wxwidgets find
>> method currently does not work for the MinGW-w64/MSYS2 platform. Nevertheless,
>> since our wxwidgets code with old IPC method did build correctly on MSVC before
>> with this find method, I assume whatever correction you have to make to
>> cmake/modules/findwxWidgets.cmake to get the Windows find method to work
>> correctly on the MinGW-w64/MSYS2 platform should be quite small.
>> And as per usual, the cmake options --debug-output --trace are extremely useful for
>> debugging find modules, but if those are not sufficient to discover the problem, you
>> can always locally insert
>> message(...) commands in cmake/modules/findwxWidgets.cmake.
>>
>

> Ah, but the issue is that under MinGW-w64/MSYS2 things are installed
in different directories and possibly a different structure than under
Windows with MSVC. MinGW-w64/MSYS2 is a bit of a hybrid system, though
leaning towards the Unix way.

I agree on the hybrid nature of that platform and very likely part of
that is the wxwidgets libraries are built on MinGW-w64/MSYS2 the
"Windows" way since X is (thankfully since it is so slow on Windows)
not available on that platform.

Anyhow, I would advise dumping out compile (and link) flag results for both the

set(wxWidgets_FIND_STYLE "win32")

and

set(wxWidgets_FIND_STYLE "unix")

cases to see what the differences are (which I think were originally
designed for the "MinGW Makefiles" and "MSYS Makefiles" cases for the
old MinGW/MSYS platform).

Because of the hybrid nature of MinGW-w64/MSYS2 you might need some
combination of both sets of those compile flags (e.g., -I flags
from "unix" results and the other non-I compile flags from "win32"
results.  Or vice versa).

Alan
__________________________
Alan W. Irwin

Astronomical research affiliation with Department of Physics and Astronomy,
University of Victoria (astrowww.phys.uvic.ca).

Programming affiliations with the FreeEOS equation-of-state
implementation for stellar interiors (freeeos.sf.net); the Time
Ephemerides project (timeephem.sf.net); PLplot scientific plotting
software package (plplot.sf.net); the libLASi project
(unifont.org/lasi); the Loads of Linux Links project (loll.sf.net);
and the Linux Brochure Project (lbproject.sf.net).
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