On Sun, Aug 7, 2016 at 11:53 AM, leif <not.rea...@online.de> wrote: > Jeroen Demeyer wrote: >> On 2016-08-07 17:26, Simon King wrote: >>> I build all these extension modules with >>> libraries = ['mtx', 'modres'] >> >> This isn't the topic of this thread, but I think it is better style to >> never put libraries in module_list.py. I prefer putting libraries in "# >> distutils" directives where you actually declare the library interface >> (that would be src/sage/libs/meataxe.pxd). See >> src/sage/libs/pari/paridecl.pxd for an example. >> >> This way, you never need to guess which modules need to link against >> -lmtx. Cython will automatically add -lmtx to anything cimporting >> meataxe.pxd. > > But this has a drawback as well, since people tend to import / include > randomly (with recursive effects) more than perhaps randomly adding > libraries in module_list (although the latter happened as well, and more > than once caused problems). ;-)
It's still the recommended way to go, as cimporting from a module that requires library X without linking library X is always an error. > And sometimes it's easier to look at one file (module_list.py) than to > scan all Cython files and guess what effectively an extension module > includes and (probably unintentionally) links to. When does one need this information? Perhaps Cython could provide better introspection (though the set of C files now include a "metadata" header about what distutils arguments should be passed for each). As to the original question, having a single meataxe shared library seems cleaner to me than each extension linking in its own separate copy, with the global set once by __init__.py, but I don't know how well meataxe lends itself to this. >> One caveat: this works better if you split the declarations of types >> from the declarations of functions. See src/sage/libs/gmp/types.pxd for >> an example. This types.pxd does not need to link against the library. >> >> In src/sage/matrix/matrix_gfpn_dense.pxd you can then replace the line >> from sage.libs.meataxe cimport * >> by >> from sage.libs.meataxe.types cimport Matrix_t >> Of course, the file src/sage/matrix/matrix_gfpn_dense.pyx would need to >> cimport more stuff from meataxe. > > That doesn't just apply to Cython headers, but also upstream (in this > case, meataxe.h). Also PARI is a good example to look at; split public > and private/internal, type definitions, inline functions, macros, > function declarations, [global] variable *declarations* (if at all > necessary) into separate header files. (Likewise, if at all needed, > global variables could be put into a separate module, as opposed to > putting them also into the library everybody links to.) > > > -leif > > > -- > You received this message because you are subscribed to the Google Groups > "sage-devel" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sage-devel+unsubscr...@googlegroups.com. > To post to this group, send email to sage-devel@googlegroups.com. > Visit this group at https://groups.google.com/group/sage-devel. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
