standalone: Disable tests requiring return of non-primitive values

Non-primitive values are represented by an `alloca`-ed value in the
function body, and when the pointer is returned from the function, the
`alloca`-ed object is deallocated on the stack.

Related to #54.

nac3core/src/typecheck/function_check.rs

@@ -3,7 +3,7 @@ use crate::typecheck::typedef::TypeEnum;
 use super::type_inferencer::Inferencer;
 use super::typedef::Type;
 use nac3parser::ast::{self, Constant, Expr, ExprKind, Operator::{LShift, RShift}, Stmt, StmtKind, StrRef};
-use std::{collections::HashSet, iter::once};
+use std::{collections::HashSet, iter::once, ops::Not};
 
 impl<'a> Inferencer<'a> {
     fn should_have_value(&mut self, expr: &Expr<Option<Type>>) -> Result<(), HashSet<String>> {
@@ -302,6 +302,31 @@ impl<'a> Inferencer<'a> {
                 if let Some(value) = value {
                     self.check_expr(value, defined_identifiers)?;
                     self.should_have_value(value)?;
+
+                    // Check that the return value is a non-`alloca` type, effectively only allowing primitive types.
+                    // This is a workaround preventing the caller from using a variable `alloca`-ed in the body, which
+                    // is freed when the function returns.
+                    if let Some(ret_ty) = value.custom {
+                        if [
+                            self.primitives.int32,
+                            self.primitives.int64,
+                            self.primitives.uint32,
+                            self.primitives.uint64,
+                            self.primitives.float,
+                            self.primitives.bool,
+                        ].iter().any(|allowed_ty| self.unifier.unioned(ret_ty, *allowed_ty)).not() {
+                            // Explicitly allow ellipsis as a return value, as the type of the ellipsis is contextually
+                            // inferred and just generates an unconditional assertion
+                            if matches!(value.node, ExprKind::Constant { value: Constant::Ellipsis, .. }).not() {
+                                return Err(HashSet::from([
+                                    format!(
+                                        "return value of type {} must be a primitive",
+                                        self.unifier.stringify(ret_ty),
+                                    ),
+                                ]))
+                            }
+                        }
+                    }
                 }
                 Ok(true)
             }

nac3standalone/demo/src/classes.py

@@ -23,8 +23,8 @@ class A:
     def get_a(self) -> int32:
         return self.a
     
-    def get_b(self) -> B:
-        return self.b
+    # def get_b(self) -> B:
+    #     return self.b
 
 
 def run() -> int32:

nac3standalone/demo/src/operators.py

@@ -21,8 +21,8 @@ def run() -> int32:
     test_uint32()
     test_int64()
     test_uint64()
-    test_A()
-    test_B()
+    # test_A()
+    # test_B()
     return 0
 
 def test_int32():
@@ -173,91 +173,92 @@ def test_uint64():
     a >>= uint32(b)
     output_uint64(a)
 
-class A:
-    a: int32
-    def __init__(self, a: int32):
-        self.a = a
-    
-    def __add__(self, other: A) -> A:
-        output_int32(self.a + other.a)
-        return A(self.a + other.a)
-
-    def __sub__(self, other: A) -> A:
-        output_int32(self.a - other.a)
-        return A(self.a - other.a)
-
-def test_A():
-    a = A(17)
-    b = A(3)
-    
-    c = a + b
-    # fail due to alloca in __add__ function
-    # output_int32(c.a)
-
-    a += b
-    # fail due to alloca in __add__ function
-    # output_int32(a.a)
-    
-    a = A(17)
-    b = A(3)
-    d = a - b
-    # fail due to alloca in __add__ function
-    # output_int32(c.a)
-
-    a -= b
-    # fail due to alloca in __add__ function
-    # output_int32(a.a)
-
-    a = A(17)
-    b = A(3)
-    a.__add__(b)
-    a.__sub__(b)
-
-
-class B:
-    a: int32
-    def __init__(self, a: int32):
-        self.a = a
-    
-    def __add__(self, other: B) -> B:
-        output_int32(self.a + other.a)
-        return B(self.a + other.a)
-
-    def __sub__(self, other: B) -> B:
-        output_int32(self.a - other.a)
-        return B(self.a - other.a)
-    
-    def __iadd__(self, other: B) -> B:
-        output_int32(self.a + other.a + 24)
-        return B(self.a + other.a + 24)
-
-    def __isub__(self, other: B) -> B:
-        output_int32(self.a - other.a - 24)
-        return B(self.a - other.a - 24)
-
-def test_B():
-    a = B(17)
-    b = B(3)
-    
-    c = a + b
-    # fail due to alloca in __add__ function
-    # output_int32(c.a)
-
-    a += b
-    # fail due to alloca in __add__ function
-    # output_int32(a.a)
-    
-    a = B(17)
-    b = B(3)
-    d = a - b
-    # fail due to alloca in __add__ function
-    # output_int32(c.a)
-
-    a -= b
-    # fail due to alloca in __add__ function
-    # output_int32(a.a)
-
-    a = B(17)
-    b = B(3)
-    a.__add__(b)
-    a.__sub__(b)
+# FIXME Fix returning objects of non-primitive types; Currently this is disabled in the function checker
+# class A:
+#     a: int32
+#     def __init__(self, a: int32):
+#         self.a = a
+#
+#     def __add__(self, other: A) -> A:
+#         output_int32(self.a + other.a)
+#         return A(self.a + other.a)
+#
+#     def __sub__(self, other: A) -> A:
+#         output_int32(self.a - other.a)
+#         return A(self.a - other.a)
+#
+# def test_A():
+#     a = A(17)
+#     b = A(3)
+#
+#     c = a + b
+#     # fail due to alloca in __add__ function
+#     # output_int32(c.a)
+#
+#     a += b
+#     # fail due to alloca in __add__ function
+#     # output_int32(a.a)
+#
+#     a = A(17)
+#     b = A(3)
+#     d = a - b
+#     # fail due to alloca in __add__ function
+#     # output_int32(c.a)
+#
+#     a -= b
+#     # fail due to alloca in __add__ function
+#     # output_int32(a.a)
+#
+#     a = A(17)
+#     b = A(3)
+#     a.__add__(b)
+#     a.__sub__(b)
+#
+#
+# class B:
+#     a: int32
+#     def __init__(self, a: int32):
+#         self.a = a
+#
+#     def __add__(self, other: B) -> B:
+#         output_int32(self.a + other.a)
+#         return B(self.a + other.a)
+#
+#     def __sub__(self, other: B) -> B:
+#         output_int32(self.a - other.a)
+#         return B(self.a - other.a)
+#
+#     def __iadd__(self, other: B) -> B:
+#         output_int32(self.a + other.a + 24)
+#         return B(self.a + other.a + 24)
+#
+#     def __isub__(self, other: B) -> B:
+#         output_int32(self.a - other.a - 24)
+#         return B(self.a - other.a - 24)
+#
+# def test_B():
+#     a = B(17)
+#     b = B(3)
+#
+#     c = a + b
+#     # fail due to alloca in __add__ function
+#     # output_int32(c.a)
+#
+#     a += b
+#     # fail due to alloca in __add__ function
+#     # output_int32(a.a)
+#
+#     a = B(17)
+#     b = B(3)
+#     d = a - b
+#     # fail due to alloca in __add__ function
+#     # output_int32(c.a)
+#
+#     a -= b
+#     # fail due to alloca in __add__ function
+#     # output_int32(a.a)
+#
+#     a = B(17)
+#     b = B(3)
+#     a.__add__(b)
+#     a.__sub__(b)