Merge pull request #1917 from Smit-create/i-1915

CPython: Fix Union bugs

Author: certik

integration_tests/CMakeLists.txt

@@ -559,7 +559,7 @@ RUN(NAME enum_06             LABELS cpython llvm c)
 RUN(NAME enum_07             IMPORT_PATH ..
                              LABELS cpython llvm c)
 RUN(NAME union_01            LABELS cpython llvm c)
-RUN(NAME union_02            LABELS llvm c)
+RUN(NAME union_02            LABELS cpython llvm c)
 RUN(NAME union_03            LABELS cpython llvm c)
 RUN(NAME union_04            IMPORT_PATH ..
                              LABELS cpython llvm c)

integration_tests/union_02.py

@@ -19,9 +19,9 @@ class C:
 @ccall
 @union
 class D(Union):
-    a: A = A()
-    b: B = B()
-    c: C = C()
+    a: A = A(0, 3.0)
+    b: B = B(i64(0), 2.0)
+    c: C = C(i64(0), 0.0, 1.0)
 
 def test_struct_union():
     d: D = D()

src/runtime/lpython/lpython.py

@@ -4,6 +4,7 @@
 import platform
 from dataclasses import dataclass as py_dataclass, is_dataclass as py_is_dataclass
 
+
 # TODO: this does not seem to restrict other imports
 __slots__ = ["i8", "i16", "i32", "i64", "u8", "u16", "u32", "u64", "f32", "f64", "c32", "c64", "CPtr",
         "overload", "ccall", "TypeVar", "pointer", "c_p_pointer", "Pointer",
@@ -89,10 +90,19 @@ def __init__(self, type, dims):
 Const = ConstType("Const")
 Callable = Type("Callable")
 Allocatable = Type("Allocatable")
-Union = ctypes.Union
 Pointer = PointerType("Pointer")
 
 
+class Union:
+    def __init__(self):
+        pass
+
+    def __setattr__(self, name: str, value):
+        self.__dict__[name] = value
+
+    def __getattr__(self, name: str):
+        return self.__dict__[name]
+
 class Intent:
     def __init__(self, type):
         self._type = type
@@ -381,7 +391,6 @@ def convert_to_ctypes_Union(f):
     for name in f.__annotations__:
         ltype_ = f.__annotations__[name]
         fields.append((name, convert_type_to_ctype(ltype_)))
-
     f._fields_ = fields
     f.__annotations__ = {}
 
@@ -467,12 +476,16 @@ def inner(fn):
 
 def union(f):
     fields = []
+    fa = {}
     for name in f.__annotations__:
         ltype_ = f.__annotations__[name]
-        fields.append((name, convert_type_to_ctype(ltype_)))
+        ltype_ = convert_type_to_ctype(ltype_)
+        fa[name] = ltype_
+
+        fields.append((name, ltype_))
 
     f._fields_ = fields
-    f.__annotations__ = {}
+    f.__annotations__ = fa
     return f
 
 def pointer(x, type_=None):