Merge pull request #18361 from pearu/16347

ENH: Share memory of read-only intent(in) arrays.

3 files changed, 16 insertions, 3 deletions

diff --git a/numpy/f2py/rules.py b/numpy/f2py/rules.py
index 4e1cf0c7d..b9cbc5487 100755
--- a/numpy/f2py/rules.py
+++ b/numpy/f2py/rules.py
@@ -809,7 +809,7 @@ if (#varname#_cb.capi==Py_None) {
 """,
             {debugcapi: ["""\
         fprintf(stderr,\"debug-capi:Assuming %d arguments; at most #maxnofargs#(-#nofoptargs#) is expected.\\n\",#varname#_cb.nofargs);
-        CFUNCSMESSPY(\"for #varname#=\",#cbname#_capi);""",
+        CFUNCSMESSPY(\"for #varname#=\",#varname#_cb.capi);""",
                          {l_not(isintent_callback): """        fprintf(stderr,\"#vardebugshowvalue# (call-back in C).\\n\",#cbname#);"""}]},
             """\
         CFUNCSMESS(\"Saving callback variables for `#varname#`.\\n\");
diff --git a/numpy/f2py/src/fortranobject.c b/numpy/f2py/src/fortranobject.c
index 3275f90ad..b9ef18701 100644
--- a/numpy/f2py/src/fortranobject.c
+++ b/numpy/f2py/src/fortranobject.c
@@ -799,7 +799,7 @@ PyArrayObject* array_from_pyobj(const int type_num,
             && ARRAY_ISCOMPATIBLE(arr,type_num)
             && F2PY_CHECK_ALIGNMENT(arr, intent)
             ) {
-            if ((intent & F2PY_INTENT_C)?PyArray_ISCARRAY(arr):PyArray_ISFARRAY(arr)) {
+            if ((intent & F2PY_INTENT_C)?PyArray_ISCARRAY_RO(arr):PyArray_ISFARRAY_RO(arr)) {
                 if ((intent & F2PY_INTENT_OUT)) {
                     Py_INCREF(arr);
                 }
@@ -807,9 +807,9 @@ PyArrayObject* array_from_pyobj(const int type_num,
                 return arr;
             }
         }
-
         if (intent & F2PY_INTENT_INOUT) {
             strcpy(mess, "failed to initialize intent(inout) array");
+            /* Must use PyArray_IS*ARRAY because intent(inout) requires writable input */
             if ((intent & F2PY_INTENT_C) && !PyArray_ISCARRAY(arr))
                 strcat(mess, " -- input not contiguous");
             if (!(intent & F2PY_INTENT_C) && !PyArray_ISFARRAY(arr))
diff --git a/numpy/f2py/tests/test_array_from_pyobj.py b/numpy/f2py/tests/test_array_from_pyobj.py
index 0524da342..77149e4e7 100644
--- a/numpy/f2py/tests/test_array_from_pyobj.py
+++ b/numpy/f2py/tests/test_array_from_pyobj.py
@@ -233,6 +233,7 @@ class Array:
                     order=self.intent.is_intent('c') and 'C' or 'F')
             assert_(self.pyarr.dtype == typ,
                     repr((self.pyarr.dtype, typ)))
+        self.pyarr.setflags(write=self.arr.flags['WRITEABLE'])
         assert_(self.pyarr.flags['OWNDATA'], (obj, intent))
         self.pyarr_attr = wrap.array_attrs(self.pyarr)
 
@@ -326,6 +327,18 @@ class TestSharedMemory:
             else:
                 assert_(not a.has_shared_memory(), repr(t.dtype))
 
+    @pytest.mark.parametrize('write', ['w', 'ro'])
+    @pytest.mark.parametrize('order', ['C', 'F'])
+    @pytest.mark.parametrize('inp', ['2seq', '23seq'])
+    def test_in_nocopy(self, write, order, inp):
+        """Test if intent(in) array can be passed without copies
+        """
+        seq = getattr(self, 'num' + inp)
+        obj = np.array(seq, dtype=self.type.dtype, order=order)
+        obj.setflags(write=(write == 'w'))
+        a = self.array(obj.shape, ((order=='C' and intent.in_.c) or intent.in_), obj)
+        assert a.has_shared_memory()
+
     def test_inout_2seq(self):
         obj = np.array(self.num2seq, dtype=self.type.dtype)
         a = self.array([len(self.num2seq)], intent.inout, obj)