TEST: Add cpython_interop initial example for LLVM

Author: ubaidsk

integration_tests/CMakeLists.txt

@@ -599,6 +599,7 @@ RUN(NAME bindpy_01           LABELS cpython c_py ENABLE_CPYTHON NOFAST COPY_TO_B
 RUN(NAME bindpy_02           LABELS cpython c_py LINK_NUMPY COPY_TO_BIN bindpy_02_module.py)
 RUN(NAME bindpy_03           LABELS cpython c_py LINK_NUMPY NOFAST COPY_TO_BIN bindpy_03_module.py)
 RUN(NAME bindpy_04           LABELS cpython c_py LINK_NUMPY NOFAST COPY_TO_BIN bindpy_04_module.py)
+RUN(NAME bindpy_05           LABELS llvm_py c_py ENABLE_CPYTHON COPY_TO_BIN bindpy_05_module.py)
 RUN(NAME test_generics_01    LABELS cpython llvm c NOFAST)
 RUN(NAME test_cmath          LABELS cpython llvm c NOFAST)
 RUN(NAME test_complex_01        LABELS cpython llvm c wasm wasm_x64)

integration_tests/bindpy_05.py

@@ -0,0 +1,80 @@
+from lpython import ccall, Pointer, i32, empty_c_void_p, CPtr, pointer
+
+
+@ccall(header="Python.h")
+def Py_Initialize():
+    pass
+
+@ccall(header="Python.h")
+def Py_DecodeLocale(s: str, p: CPtr) -> CPtr:
+    pass
+
+@ccall(header="Python.h")
+def PySys_SetArgv(n: i32, args: Pointer[CPtr]):
+    pass
+
+@ccall(header="Python.h")
+def Py_FinalizeEx() -> i32:
+    pass
+
+@ccall(header="Python.h")
+def PyUnicode_FromString(s: str) -> CPtr:
+    pass
+
+@ccall(header="Python.h")
+def PyImport_Import(name: CPtr) -> CPtr:
+    pass
+
+@ccall(header="Python.h")
+def _Py_DecRef(name: CPtr):
+    pass
+
+@ccall(header="Python.h")
+def PyObject_GetAttrString(m: CPtr, s: str) -> CPtr:
+    pass
+
+@ccall(header="Python.h")
+def PyTuple_New(n: i32) -> CPtr:
+    pass
+
+@ccall(header="Python.h")
+def PyObject_CallObject(a: CPtr, b: CPtr) -> CPtr:
+    pass
+
+@ccall(header="Python.h")
+def PyLong_AsLongLong(a: CPtr) -> i32:
+    pass
+
+def my_f():
+    pName: CPtr; pModule: CPtr; pFunc: CPtr; pArgs: CPtr; pValue: CPtr
+
+    pName = PyUnicode_FromString("bindpy_05_module")
+    assert pName != empty_c_void_p(), "Failed to convert to unicode string bindpy_05_module\n"
+
+    pModule = PyImport_Import(pName)
+    _Py_DecRef(pName)
+    assert pModule != empty_c_void_p(), "Failed to load python module bindpy_05_module\n"
+
+    pFunc = PyObject_GetAttrString(pModule, "my_f")
+    assert pFunc !=  empty_c_void_p(), "Cannot find function my_f\n"
+
+    pArgs = PyTuple_New(0)
+    pValue = PyObject_CallObject(pFunc, pArgs)
+    _Py_DecRef(pArgs)
+    assert pValue !=  empty_c_void_p(), "Call to my_f failed\n"
+
+    ans: i32 = PyLong_AsLongLong(pValue)
+    print("Ans is", ans)
+    assert ans == 5
+
+
+def main0():
+    Py_Initialize()
+    argv1: CPtr = Py_DecodeLocale("", empty_c_void_p())
+    PySys_SetArgv(1, pointer(argv1))
+
+    my_f()
+
+    assert(Py_FinalizeEx() >= 0), "BindPython: Unknown Error in FinalizeEx()\n"
+
+main0()

integration_tests/bindpy_05_module.py

@@ -0,0 +1,3 @@
+def my_f():
+    print("hello from python")
+    return 5