Add test for loading libraries via ctypes

Author: msimacek

graalpython/com.oracle.graal.python.test/src/tests/test_ctypes.py

@@ -0,0 +1,125 @@
+# Copyright (c) 2025, Oracle and/or its affiliates. All rights reserved.
+# DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+#
+# The Universal Permissive License (UPL), Version 1.0
+#
+# Subject to the condition set forth below, permission is hereby granted to any
+# person obtaining a copy of this software, associated documentation and/or
+# data (collectively the "Software"), free of charge and under any and all
+# copyright rights in the Software, and any and all patent rights owned or
+# freely licensable by each licensor hereunder covering either (i) the
+# unmodified Software as contributed to or provided by such licensor, or (ii)
+# the Larger Works (as defined below), to deal in both
+#
+# (a) the Software, and
+#
+# (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
+# one is included with the Software each a "Larger Work" to which the Software
+# is contributed by such licensors),
+#
+# without restriction, including without limitation the rights to copy, create
+# derivative works of, display, perform, and distribute the Software and make,
+# use, sell, offer for sale, import, export, have made, and have sold the
+# Software and the Larger Work(s), and to sublicense the foregoing rights on
+# either these or other terms.
+#
+# This license is subject to the following condition:
+#
+# The above copyright notice and either this complete permission notice or at a
+# minimum a reference to the UPL must be included in all copies or substantial
+# portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+import shutil
+import subprocess
+import sys
+import tempfile
+import textwrap
+import unittest
+from pathlib import Path
+
+from tests.testlib_helper import build_testlib
+
+
+class TestCtypesInterop(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        orig_root = Path(__file__).parent.resolve()
+        orig_testlib = orig_root / "testlib"
+        cls.tmpdir = Path(tempfile.mkdtemp(prefix="testctypes_tmp_"))
+        cls.lib_path = build_testlib(cls.tmpdir, orig_testlib)
+
+    @classmethod
+    def tearDownClass(cls):
+        shutil.rmtree(cls.tmpdir, ignore_errors=True)
+
+    def run_in_subprocess(self, code, *args):
+        proc = subprocess.run(
+            [sys.executable, "-c", code, *args],
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+            text=True,
+        )
+        if proc.returncode != 0:
+            self.fail(
+                "Subprocess failed with exit code {}\nstdout:\n{}\nstderr:\n{}".format(
+                    proc.returncode, proc.stdout, proc.stderr
+                )
+            )
+
+    def test_ctypes_load_and_call(self):
+        # Pass the library path as an argument
+        code = textwrap.dedent(
+            """
+            import sys
+            from ctypes import CDLL, c_int
+            lib_path = sys.argv[1]
+            lib = CDLL(lib_path)
+            get_answer = lib.get_answer
+            get_answer.restype = c_int
+            result = get_answer()
+            assert result == 42, f'expected 42, got {result}'
+            """
+        )
+        self.run_in_subprocess(code, str(self.lib_path))
+
+    @unittest.skipIf(sys.platform != "win32", "Windows-only test")
+    def test_os_add_dll_directory_and_unload(self):
+        # Pass the library dir as argument
+        code = textwrap.dedent(
+            """
+            import os
+            import sys
+            from pathlib import Path
+            from ctypes import CDLL, c_int
+            lib_dir = Path(sys.argv[1])
+            dll_dir = lib_dir.parent
+            dll_name = lib_dir.name
+            # Should fail to load when DLL dir not added
+            try:
+                CDLL(dll_name)
+            except OSError:
+                pass
+            else:
+                raise AssertionError("CDLL(dll_name) should fail outside dll dir context")
+            # Should succeed when DLL dir is temporarily added
+            with os.add_dll_directory(dll_dir):
+                lib = CDLL(dll_name)
+                get_answer = lib.get_answer
+                get_answer.restype = c_int
+                result = get_answer()
+                assert result == 42, f'expected 42, got {result}'
+            """
+        )
+        self.run_in_subprocess(code, str(self.lib_path))
+
+
+if __name__ == "__main__":
+    unittest.main()

graalpython/com.oracle.graal.python.test/src/tests/test_wheel.py

@@ -65,7 +65,7 @@ def test_build_install_and_run(self):
             repaired_dir = tmpdir / "repaired"
 
             shutil.copytree(orig_test_wheel, tmp_test_wheel)
-            testlib_build = build_testlib(tmpdir, orig_testlib)
+            testlib_build = build_testlib(tmpdir, orig_testlib).parent
 
             cmd = [sys.executable, "-m", "venv", str(venv_dir)]
             print("Running:", shlex.join(cmd))

graalpython/com.oracle.graal.python.test/src/tests/testlib_helper.py

@@ -40,6 +40,7 @@
 import shlex
 import shutil
 import subprocess
+import sys
 
 
 def build_testlib(tmpdir, orig_testlib):
@@ -56,4 +57,15 @@ def build_testlib(tmpdir, orig_testlib):
     cmd = ["cmake", "--build", ".", "--config", "Release"]
     print("Running:", shlex.join(cmd))
     subprocess.check_call(cmd, cwd=str(testlib_build))
-    return testlib_build
+
+    if sys.platform == 'win32':
+        lib_name = "answer.dll"
+    elif sys.platform == 'darwin':
+        lib_name = "libanswer.dylib"
+    else:
+        lib_name = 'libanswer.so'
+    lib_path = testlib_build / lib_name
+    if not lib_path.exists():
+        raise FileNotFoundError(f"Failed to locate built library at: {lib_path}")
+
+    return lib_path