Re: wxWidgets terminal (another bug report)

[<tim...@en...>]

>> Configuration fails if wxWidgets is disabled:
>>
>> lascaux [27] ./configure --disable-wxwidgets
>> checking for a BSD-compatible install... /usr/bin/install -c
>> checking whether build environment is sane... yes
>> checking for gawk... gawk
>> checking whether make sets $(MAKE)... yes
>> [...snip...]
>> checking for pdflib.h... yes
>> checking for PDF_begin_pattern in -lpdf... yes
>> checking for PDF_setdashpattern in -lpdf... yes
>> checking for PDF_begin_document in -lpdf... yes
>> checking for multi-byte support in x11... checking for XmbDrawString i=
n
>> -lX11... yes
>> configure: error: conditional "am__fastdepCXX" was never defined.
>> Usually this means the macro was only invoked conditionally.
>> lascaux [28]
>
> The error is pretty explicit. The problem is that I put the following
> checks in 'if' block :
>
> AC_PROG_CXX
> AC_PROG_CXXCPP
>
> I did that because C++ is not needed if the wxWidgets terminal is not
> compiled. But I have not found any information about such a case on the
> web.
> Obviously this doesn't work, so I will have to put them
> unconditionnally... at the risk of breaking a platform where there's no
> C++ compiler. Is it acceptable ?

I have been in big trouble !

The autotools are definitely not designed to make a language optional.

As reported above, the checks must be done unconditionally or Autoconf
won't work.

If I put the two checks unconditionally, and execute the resulting
'configure' on a system without any C++ compiler, the script itself will
succeed, and I can even disable the wxWidgets terminal, but it will fail
at compile time, because the autotools still think that the project
contains some C++ files, and tries to link with g++ by default, even when
it can't find it !

So this would oblige to have a C++ compiler to build gnuplot, even withou=
t
the wxWidgets terminal. I respond to my question above : this is obviousl=
y
not acceptable.

I have finally found a workaround : if the C++ compiler is really absent
(that can be tested easily), set CXX to $CC, so that automake will finall=
y
use $CC to do the link. I have tested it, and it seems to work as
expected.

(but I am not really happy with that, and it made me wonder once again if
I should throw wxWidgets in favor of gtk+, which is written in C...)

Timoth=E9e