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LibGAP ====== A C library version of the GAP kernel. GAP (http://www.gap-system.org) is a system for computational group theory. This repo contains a shared library version of the GAP kernel, allowing to directly talk to GAP from C/C++ code. Much of the group theory in SageMath (http://www.sagemath.org) is implemented using LibGAP. Requirements ============ Runtime: * the GAP library (scripts in the GAP language) * GMP/MPIR shared library Compile-time: * GMP/MPIR headers Packaging (to run "make dist"): * Python * The Python PLY module (http://www.dabeaz.com/ply) Packaging ========= The current tarball can be found at https://bitbucket.org/vbraun/libgap/downloads/libgap-x.y.z.tar.gz * Always use the libgap-x.y.z.tar.gz tarball (the output of "make dist"), and not the files in the repository. Only the former has its symbols transformed with the "libGAP_" prefix. * For the testsuite, you need to have the gap library installed somewhere. Configure and make libGAP with -DSYS_DEFAULT_PATHS=<gap_root> cflags tests, where the path is quoted so as to end up with quotation marks in C sources: $ ./configure CFLAGS='-DSYS_DEFAULT_PATHS=\"/path/to/gap\"' or $ export CFLAGS='-DSYS_DEFAULT_PATHS=\"/home/vbraun/Sage/git/local/gap/latest\"' $ ./configure $ make check For example, using the GAP installation in SageMath: $ ./configure CFLAGS='-DSYS_DEFAULT_PATHS=\"$SAGE_ROOT/local/gap/latest\"' Hacking ======= LibGAP aims to track upstream GAP development as close as possible. To update LibGAP-x.y.z to a new GAP-x.y.(z+1) release, use the following steps: 1. Copy the previous and new GAP src directory to upstream-gap-x.y.z and upstream-gap-x.y.(z+1), respectively. 2. Run scripts/generate_patch.sh, which will generate patches/gap-x.y.z.patch 3. Replace the C sources in LibGAP's src with the new upstream-gap-x.y.(z+1): cp upstream/src/*.[c,h] src/ 4. Apply patches/gap-x.y.z.patch to the new src directory. Hopefully, there are no conflicts. Good luck! $ cd src && patch -p1 < ../patches/gap-x.y.z.patch 5. Update src/Makefile.am if C sources have been added/removed. 6. Update the version in src/libgap.map. 7. Update the version in configure.ac and run $ autoreconf -fiv 8. Run "make distcheck" (the testsuite will fail because it does not pass CFLAGS -- ignore that). The tests use unescaped GAP symbols since it's easier to develop. The test/Makefile.am dist-hook rewrites them with the libGAP_ prefix. If you change tests make sure to update the dist-hook to also prefix any new GAP symbols that you use in the tests. For debugging you should probably build GAP and LibGAP with debug symbols: $ ./configure CFLAGS='-O0 -g3' # standalone GAP $ SAGE_DEBUG=yes ./sage -f gap # inside SageMath $ ./configure CFLAGS='-DSYS_DEFAULT_PATHS=\"/path/to/gap\" -O0 -g3 -DDEBUG_MASTERPOINTERS -DDEBUG_GLOBAL_BAGS -DDEBUG_FUNCTIONS_BAGS' Usage ===== See SageMath, and in particular $SAGE_ROOT/sage/libs/gap/, for real-world usage of LibGAP. SageMath contains a Cython interface to LibGAP if you are so inclined. Talk about LibGAP: * Slides: https://bitbucket.org/vbraun/libgap/downloads/libGAP.pdf * Video: https://www.youtube.com/watch?v=0gOL0QRHkmA