WASM build

[agriyakhetarpal]

Closes #234

• Build
  • libgmp
  • libmpfr
  • flint
  • python-flint
• Test

[agriyakhetarpal]

I've been testing it a bit through a PR in my fork, and it all builds well, up to one point in the Cython sources where it fails in step 107/114: https://github.com/agriyakhetarpal/python-flint/actions/runs/13576857716/job/37954995494?pr=1

with the following error trace:

FAILED: src/flint/types/_gr.cpython-312-wasm32-emscripten.so.p/meson-generated_src_flint_types__gr.pyx.c.o 
/tmp/tmp8t79rr74/cc -Isrc/flint/types/_gr.cpython-312-wasm32-emscripten.so.p -Isrc/flint/types -I../src/flint/types -I/opt/hostedtoolcache/Python/3.12.9/x64/include/python3.12 -I/home/runner/work/python-flint/python-flint/wasm-library-dir/include -fvisibility=hidden -fdiagnostics-color=always -DNDEBUG -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -O3 -fPIC -MD -MQ src/flint/types/_gr.cpython-312-wasm32-emscripten.so.p/meson-generated_src_flint_types__gr.pyx.c.o -MF src/flint/types/_gr.cpython-312-wasm32-emscripten.so.p/meson-generated_src_flint_types__gr.pyx.c.o.d -o src/flint/types/_gr.cpython-312-wasm32-emscripten.so.p/meson-generated_src_flint_types__gr.pyx.c.o -c src/flint/types/_gr.cpython-312-wasm32-emscripten.so.p/src/flint/types/_gr.pyx.c
src/flint/types/_gr.cpython-312-wasm32-emscripten.so.p/src/flint/types/_gr.pyx.c:19051:65: error: incompatible integer to pointer conversion passing 'mp_limb_t' (aka 'unsigned long') to parameter of type 'const fmpz *' (aka 'const long *') [-Wint-conversion]
 19051 |   gr_ctx_init_fq_nmod(__pyx_v_ctx->__pyx_base.__pyx_base.ctx_t, __pyx_v_p, __pyx_v_d, __pyx_v_name);
       |                                                                 ^~~~~~~~~
/home/runner/work/python-flint/python-flint/wasm-library-dir/include/flint/gr.h:1366:53: note: passing argument to parameter 'p' here
 1366 | void gr_ctx_init_fq_nmod(gr_ctx_t ctx, const fmpz_t p, slong d, const char * var);
      |                                                     ^
src/flint/types/_gr.cpython-312-wasm32-emscripten.so.p/src/flint/types/_gr.pyx.c:19150:65: error: incompatible integer to pointer conversion passing 'mp_limb_t' (aka 'unsigned long') to parameter of type 'const fmpz *' (aka 'const long *') [-Wint-conversion]
 19150 |   gr_ctx_init_fq_zech(__pyx_v_ctx->__pyx_base.__pyx_base.ctx_t, __pyx_v_p, __pyx_v_d, __pyx_v_name);
       |                                                                 ^~~~~~~~~
/home/runner/work/python-flint/python-flint/wasm-library-dir/include/flint/gr.h:1367:53: note: passing argument to parameter 'p' here
 1367 | void gr_ctx_init_fq_zech(gr_ctx_t ctx, const fmpz_t p, slong d, const char * var);
      |                                                     ^
2 errors generated.

[agriyakhetarpal]

FWIW; I hardly have any Cython development experience, so I will have to wrap my head around this a bit, unless someone has an idea for a fix. The basis for the failure here is that WASM is stricter about type conversions than compilation for other platforms, which is why this mismatch is causing errors.

[agriyakhetarpal]

Okay – the cause of the error, more specifically, is that gr_fq_nmod_ctx and gr_fq_zech_ctx pass a ulong parameter p

python-flint/src/flint/types/_gr.pxd

Lines 1189 to 1202 in 34dbb5d

	@cython.no_gc
	cdef class gr_fq_zech_ctx(gr_scalar_ctx):
	cdef ulong p
	cdef slong d
	@staticmethod
	cdef inline gr_fq_zech_ctx _new(ulong p, slong d, char* name):
	cdef gr_fq_zech_ctx ctx
	ctx = gr_fq_zech_ctx.__new__(gr_fq_zech_ctx)
	ctx.p = p
	ctx.d = d
	gr_ctx_init_fq_zech(ctx.ctx_t, p, d, name)
	ctx._init = True
	return ctx

but flint/gr.h has fmpz_t in version 3.0.1: https://github.com/flintlib/flint/blob/c05007be863b1aae7221f11a9c135d673d968638/src/gr.h#L1366-L1367

and this has apparently been fixed in version v3.1.0. I'll try updating flint to v3.1.0 (before proceeding to try out v3.1.2, if I do)

[agriyakhetarpal]

Successful build: https://github.com/agriyakhetarpal/python-flint/actions/runs/13577635441?pr=1 ✨

The next task is to run tests, which I can take a look at later in the day.

[oscarbenjamin]

I haven't looked through this yet but thanks!

[oscarbenjamin]

but flint/gr.h has fmpz_t in version 3.0.1:

Best to keep with latest FLINT version for the pyodide build. There is no need to support a range of versions in pyodide. Generally python-flint tracks the latest version but has some #ifdef type stuff for older versions so that someone could build against them. No one is going to build against old versions in WASM though.

[agriyakhetarpal]

Sounds good to me! I think the tests will have a bunch of function signature mismatches, though 😬 based on what I noticed through my fork's run. Also, building itself takes ~20 minutes in total – we could get to half of that if we have prebuilt WASM binaries. I guess they could be hosted somewhere in a GitHub release when things are ready.