From: Alan W. I. <ir...@be...> - 2009-07-15 20:48:55
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On 2009-07-15 19:29+0100 Andrew Ross wrote: > On Wed, Jul 15, 2009 at 01:14:59PM -0400, Hazen Babcock wrote: >> >> (1) Do we have a minimum c++ version requirement? I couldn't find >> anything in the archives but when I tried to run cmake on svn head I get >> this error: >> >> CMake version = 2.6.4 >> The CXX compiler identification is GNU >> CMake Error at cmake/modules/c++.cmake:57 (message): >> C++ compiler absolutely required to build this project. >> Call Stack (most recent call first): >> cmake/modules/plplot.cmake:127 (include) >> CMakeLists.txt:82 (include) >> >> I also tried with 5.9.4 and I did not see this problem. I have the >> standard mingw c++ version 3.4.5, which is perhaps a little dated? > > To follow on from Werner's response: You shouldn't _need_ a C++ compiler > to compile plplot. All the core code is C. Of course you won't get the > C++ bindings or the drivers which are written in C++. Having said this > it looks like the cmake system currently insists you have one. Actually, we _were_ dependent on having a C++ compiler because the psttf device and octave bindings failed horribly without one, and check_prototype_exists (unnecessarily) demanded a working C++ compiler. I have just now (revision 10150) fixed all those issues so that for the first time a working C++ compiler is optional, i.e., the -DENABLE_cxx=OFF option works for the first time (i.e., by automatically turning PLD_psttf and ENABLE_octave to OFF), and if you don't use that option, but a C++ compiler cannot be found, the build system recovers gracefully by forcing ENABLE_cxx=OFF. (I just checked that graceful recovery by temporarily renaming /usr/bin/g++.) Revision 10150 should clear up some obfuscating issues, but I suspect Hazen's underlying issue (cannot find a C++ compiler) will still generate a warning (and ENABLE_cxx=OFF). Hazen, will you confirm your problem now shows up as that warning for svn trunk? Furthermore, if you are still getting a warning (now) about a missing C++ compiler, I frankly don't understand why 5.9.4 works for you at all without erroring out at cmake time. The C++ language was an absolute requirement for 5.9.4. The method used to find C++ had a different top-level (the project command without any languages specified is the same as demanding C and C++), but the underlying method (CMakeDetermineCXXCompiler) for finding the C++ compiler should be identical. Are you using the exact same generator and environment variables for both PLplot 5.9.4 and PLplot svn trunk? The generator and CXX environment variable will make a difference to whether you find a C++ compiler or not. 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); PLplot scientific plotting software package (plplot.org); the libLASi project (unifont.org/lasi); the Loads of Linux Links project (loll.sf.net); and the Linux Brochure Project (lbproject.sf.net). __________________________ Linux-powered Science __________________________ |