BLD: enabled negation of library choices in NPY_*_ORDER (#17219)

BLD: enabled negation of library choices in NPY_*_ORDER

When users build for a particular order it may be beneficial
to disallow certain libraries.

In particular a user may not care about which accelerated
BLAS library is used, so long as the NetLIB or ATLAS library isn't used.

This is now possible with:

   NPY_BLAS_ORDER='^blas,atlas'

or

   NPY_BLAS_ORDER='!blas,atlas'

Since we may envision more BLAS/LAPACK libraries to the pool, this
will provide greater flexibility as they enter.

A new (local) method is added in system_info.py which removes duplicate
code and allows for easier usage across libraries.

1 files changed, 27 insertions, 0 deletions

diff --git a/numpy/distutils/tests/test_system_info.py b/numpy/distutils/tests/test_system_info.py
index 0768ffdde..46ad9b103 100644
--- a/numpy/distutils/tests/test_system_info.py
+++ b/numpy/distutils/tests/test_system_info.py
@@ -285,3 +285,30 @@ class TestSystemInfoReading:
         finally:
             os.chdir(previousDir)
         
+
+def test_distutils_parse_env_order(monkeypatch):
+    from numpy.distutils.system_info import _parse_env_order
+    env = 'NPY_TESTS_DISTUTILS_PARSE_ENV_ORDER'
+
+    base_order = list('abcdef')
+
+    monkeypatch.setenv(env, 'b,i,e,f')
+    order, unknown = _parse_env_order(base_order, env)
+    assert len(order) == 3
+    assert order == list('bef')
+    assert len(unknown) == 1
+
+    for prefix in '^!':
+        monkeypatch.setenv(env, f'{prefix}b,i,e')
+        order, unknown = _parse_env_order(base_order, env)
+        assert len(order) == 4
+        assert order == list('acdf')
+        assert len(unknown) == 1
+
+    with pytest.raises(ValueError):
+        monkeypatch.setenv(env, 'b,^e,i')
+        _parse_env_order(base_order, env)
+
+    with pytest.raises(ValueError):
+        monkeypatch.setenv(env, '!b,^e,i')
+        _parse_env_order(base_order, env)