Change shared library installation directory from /lib/python3.10/site-packages/ to /usr/lib.
#2686 and this PR improve how we load shared libraries. The future goal
of these PRs is to load shared libraries on demand, instead of pre-loading
all shared libraries, which will reduce initial package load time.
With newer versions of emscripten, linker errors surface eariler.
This makes it easier to find function pointer cast errors without
having to execute the bad code path -- the errors happen when the
wasm modules are linked (at load time in the browser)
Anyways, this fixes more linker errors. Mostly the problems have
to do with LAPACK functions that take string arguments. Most
LAPACK functions that take string arguments use them as enums and
only care about the first character of the string. Because of the
way that f2c works, we need to replace these strings with the ascii
code of the first character so we should replace:
sTRSV( 'UPPER', 'NOTRANS', 'NONUNIT', J, H, LDH, Y, 1 )
==>
CALL sTRSV( 85, 78, 78, J, H, LDH, Y, 1 )
where 85 and 78 are the ascii codes of U and N. Various character
variables are subbed into being integer variables. The two
functions `ilaenv` and `xerbla` expect actual C strings as an
argument, but it is very annoying to produce C strings so instead
I added wrapper functions ilaenvf2c and xerblaf2c to clapack and
instead of calling ilaenv and xerbla we call the f2c versions.
This patch makes everything in numpy, scipy and CLAPACK that began life as a fortran subroutine return int, whereas before they were a smattering of void plus lots of int, with a bunch of conflicts where the same function was defined as int in some and void in others. This matters because on upstream emscripten, these packages will not build due to linker conflicts, as the wasm linker can't link a function returning int to a function returning void.
Annoyingly, this has to be int return not void, because whereas a normal fortran subroutine doesn't return anything, there's an obscure feature of fortran 77 called alternative returns which allows subroutines to say they want to return by jumping to some other place in the code. f2c handles this with integer return values.
This addresses part of #713, by listing and building C libraries as
dependencies. This means we automatically build CLAPACK when needed, and
`lxml`'s C dependencies are not built if lxml is not. In particular,
building "core" should now be faster.
The building itself is still performed by Makefile.
Gyeongjae Choi