Support syntax for passing struct in CPython

integration_tests/CMakeLists.txt

@@ -455,7 +455,7 @@ RUN(NAME structs_01          LABELS cpython llvm c)
 RUN(NAME structs_02          LABELS cpython llvm c)
 RUN(NAME structs_03          LABELS llvm c)
 RUN(NAME structs_04          LABELS cpython llvm c)
-RUN(NAME structs_05          LABELS llvm c)
+RUN(NAME structs_05          LABELS cpython llvm c)
 RUN(NAME structs_06          LABELS cpython llvm c)
 RUN(NAME structs_07          LABELS llvm c
         EXTRAFILES structs_07b.c)
@@ -480,6 +480,7 @@ RUN(NAME structs_21          LABELS cpython llvm c)
 RUN(NAME structs_22          LABELS cpython llvm c)
 RUN(NAME structs_23          LABELS cpython llvm c)
 RUN(NAME structs_24          LABELS cpython llvm c)
+RUN(NAME structs_25          LABELS cpython llvm c)
 RUN(NAME sizeof_01           LABELS llvm c
         EXTRAFILES sizeof_01b.c)
 RUN(NAME sizeof_02           LABELS cpython llvm c)

integration_tests/structs_05.py

@@ -50,7 +50,6 @@ def update_2(s: A[:]):
     s[1].c = i8(3)
 
 def g():
-    # TODO: Enable cpython in integration_tests.
     y: A[2] = empty([2], dtype=A)
     y[0] = A(1.1, 1, i64(1), f32(1.1), i16(1), i8(1), True)
     y[1] = A(2.2, 2, i64(2), f32(2.2), i16(2), i8(2), True)

integration_tests/structs_25.py

@@ -0,0 +1,20 @@
+from lpython import i32, dataclass
+from numpy import empty
+
+@dataclass
+class Foo:
+     x: i32
+     y: i32
+
+def init(foos: Foo[:]) -> None:
+    foos[0] = Foo(5, 21)
+
+def main0() -> None:
+    foos: Foo[1] = empty(1, dtype=Foo)
+    init(foos)
+    print("foos[0].x =", foos[0].x)
+
+    assert foos[0].x == 5
+    assert foos[0].y == 21
+
+main0()

src/runtime/lpython/lpython.py

@@ -44,6 +44,7 @@ def __call__(self, arg):
         return self._convert(arg)
 
 def dataclass(arg):
+    arg.__class_getitem__ = lambda self: None
     return py_dataclass(arg)
 
 def is_dataclass(obj):

tests/reference/asr-structs_05-fa98307.json

@@ -2,7 +2,7 @@
     "basename": "asr-structs_05-fa98307",
     "cmd": "lpython --show-asr --no-color {infile} -o {outfile}",
     "infile": "tests/../integration_tests/structs_05.py",
-    "infile_hash": "0ca482232f99c40614dc5b994fa8c9f4865fbe72f5a133b02914b5ad",
+    "infile_hash": "94d06fb2844e1060d5df5291c3ccc4bd0e2bc8a8a59651814f0c4f0e",
     "outfile": null,
     "outfile_hash": null,
     "stdout": "asr-structs_05-fa98307.stdout",