src/Makefile.am: install Python module in src/swig_python/ for testing

Running the SWIG Python tests requires that Python is able to find the
wallycore native extension. To save users from needing to build it
manually and add its location to `PYTHONPATH` themselves, we add a
target dependency in `src/Makefile.am` to trigger the Python build
before we'll need the native extension for running the SWIG Python
tests. It's unfortunate that we can't merely call `setup.py build` and
then ask setuptools where it stashed its staging copy of the module, as
there seems to be no accessible query interface for that information. So
instead we have to tell `setup.py` to install the module to a location
that we do know, and then we can pass that location in `PYTHONPATH` when
we run the SWIG Python tests.

See: #501 (comment)

Author: whitslack

.gitignore

@@ -46,9 +46,10 @@ src/swig_java/swig_java_wrap.c
 src/swig_java/*.java
 src/swig_java/*.jar
 src/swig_java/src/com/blockstream/libwally
+src/swig_python/_wallycore.*.so
 src/swig_python/swig_python_wrap.c
 src/swig_python/wallycore/__init__.py
-src/swig_python/wallycore/wallycore.egg-info
+src/swig_python/wallycore*.egg-info
 tools/build-aux/m4/l*.m4
 tools/build-aux/test-driver
 tools/build-aux/*-e

src/Makefile.am

@@ -46,7 +46,13 @@ swig_python/swig_python_wrap.c : swig_python/swig.i swig_python/python_extra.py_
     cat swig_python/wallycore.py swig_python/python_extra.py_in > swig_python/wallycore/__init__.py && \
     rm swig_python/wallycore.py
 
-PYTHON_SWIGTEST = LD_LIBRARY_PATH=.libs PYTHONDONTWRITEBYTECODE=1 $(PYTHON)
+PYTHON_SWIGTEST = LD_LIBRARY_PATH=.libs PYTHONPATH=swig_python PYTHONDONTWRITEBYTECODE=1 $(PYTHON)
+
+if SHARED_BUILD_ENABLED
+SWIG_PYTHON_TEST_DEPS = swig_python/wallycore.egg-info
+swig_python/wallycore.egg-info :
+	cd $(top_srcdir) && WALLY_ABI_PY_WHEEL_USE_LIB=shared $(PYTHON) setup.py install --install-lib src/swig_python/
+endif
 
 clean-swig-python:
 	$(AM_V_at)rm -f swig_python/swig_python_wrap.c swig_python/wallycore/__init__.py