Difference between revisions of "Building PLplot"

Revision as of 15:16, 10 January 2009

With the exception of DJGPP on (Free)DOS (where you should follow the directions at sys/dos/djgpp/readme) all PLplot builds are done with our CMake-based build system which gives good results on Unix, Linux, and Mac OS X and Cygwin, MinGW, MinGW/MSYS, and bare windows.

Building PLplot with our CMake-based build system

Our CMake-based build system has been made available as part of our development releases of PLplot starting with version 5.7.0 and is now with the exception of the DJGPP platform our sole build system. It is important to consult the CMake documentation to get the most out of our build system. That documentation is quite thorough but tends to be a bit scattered so we have collected what we think are the best general CMake documentation links for your convenience.

After consulting that documentation, install the appropriate package of CMake for your system platform. Note, you must use at least version 2.4.5 of CMake for your PLplot configuration, but our build system works with the latest version (2.6.2) of CMake as well.

Generic Unix instructions for our build system

(Optional) set environment variables to help cmake find system components that are installed in non-standard locations

Here is one particular example (which must be executed before the cmake invocation discussed below).

export CMAKE_INCLUDE_PATH=/home/software/autotools/install/include:/home/software/cgmlib/cd1.3
export CMAKE_LIBRARY_PATH=/home/software/autotools/install/lib:/home/software/cgmlib/cd1.3
export PKG_CONFIG_PATH=/home/software/libLASi/install/lib/pkgconfig

For this particular example, CMAKE_INCLUDE_PATH helps cmake to find the headers for libltdl and libcd in non-standard install locations; CMAKE_LIBRARY_PATH helps cmake to find the libltdl and libcd libraries in non-standard install locations; and PKG_CONFIG_PATH helps cmake to use the pkg-config command internally to find a libLASi pkg-config module file that is installed in a non-standard location.

In general, CMAKE_INCLUDE_PATH helps cmake find headers and other files that are installed in non-standard locations; CMAKE_LIBRARY_PATH helps cmake find libraries that are installed in non-standard locations; and PKG_CONFIG_PATH helps pkg-config (either externally or internally from cmake) find pkg-config modules installed in non-standard locations. Finally, although not used in the specific example above, the colon-separated environment variable PATH helps cmake find executables that are installed in non-standard locations.

(Optional) set environment variables to specify the compilers and compiler flags

Here is one particular example (which must be executed before the cmake invocation discussed below).

export CC="gcc -O2"
export CXX="g++ -O2"
export FC="g77 -O2"

If you don't set the environment variables above, then by default no compiler options (i.e., no optimization and no debugging symbols) are used for gcc-related compilers for our build system which makes for fast builds, but slow execution.

cmake invocation

Here is one typical example.

mkdir build_dir
cd build_dir
cmake -DCMAKE_INSTALL_PREFIX=/my/prefix \
../plplot_cmake >& cmake.out

(CMake is capable of generating builds within the source tree, but we have emphasized a build with a separate build tree here because of its fundamental advantage that the source tree remains clean with no generated files in it.)

Check the cmake.out file for any configuration issues, especially WARNING messages which signal that a component of PLplot has been removed because required system components for that component have not been found.

There are a large number of CMake options for PLplot which can be set for cmake to personalize your build. Use the ccmake front end to cmake to obtain documentation of all these options. In the above case we have specified a particular install prefix "/my/prefix" and verbose make results (essential if you want to see the exact commands used for the build).

Note in the above example an empty build directory called build_dir is used to insure a clean start, and ../plplot_cmake is a freshly checked out source tree from our svn repository or the name of the source tree created when you unpacked a PLplot source distribution tarball. Note, the name "plplot_cmake" is only for this example, and the name will most likely be something else on your system.

To start a fresh build, simply execute "cd build_dir; rm -rf *" before invoking cmake. Of course, "rm -rf *" is an extremely dangerous command (since it removes everything in the current directory and all subdirectories), but you should be okay so long as you cd to the correct directory before executing the "rm" command.

Post-cmake build, install, and build-tree and install-tree tests

The PLplot build and install follows the cmake invocation. Build-tree tests may be done with the "ctest" command. Note, these ctests can only be performed if cmake is invoked with the -DBUILD_TEST=ON option (which roughly doubles the build time because all the examples must be built). The installed tree can be tested with the PLplot install-tree test for a large variety of PLplot device drivers.