Use 'Expression.MakeStruct' rather than a sequence of cast operations to construct lists.

Author: braxtonmckee

typed_python/compiler/native_ast_to_llvm.py

@@ -849,7 +849,7 @@ def _convert(self, expr):
             for i in range(len(exprs)):
                 value = self.builder.insert_value(value, exprs[i], i)
 
-            return TypedLLVMValue(value, native_ast.Type.Struct(names_and_types))
+            return TypedLLVMValue(value, native_ast.Type.Struct(element_types=names_and_types))
 
         if expr.matches.StructElementByIndex:
             val = self.convert(expr.left)

typed_python/compiler/tests/list_of_compilation_test.py

@@ -42,6 +42,16 @@ def checkFunction(self, f, argsToCheck):
             self.assertEqual(fastval, slowval)
         return t_py, t_fast
 
+    def test_compiled_empty_list(self):
+        @Entrypoint
+        def f():
+            return ListOf(int)()
+
+        lst = f()
+
+        assert isinstance(lst, ListOf(int))
+        assert lst.reserved() == 1
+
     def test_list_of_list_refcounts(self):
         @Compiled
         def f(x: ListOf(ListOf(int)), z: bool):

typed_python/compiler/type_wrappers/list_of_wrapper.py

@@ -360,13 +360,17 @@ def createEmptyList(self, context, out):
             out.expr.store(
                 runtime_functions.malloc.call(28).cast(self.getNativeLayoutType())
             )
-            >> out.nonref_expr.ElementPtrIntegers(0, 0).store(native_ast.const_int_expr(1))  # refcount
-            >> out.nonref_expr.ElementPtrIntegers(0, 1).store(native_ast.const_int32_expr(-1))  # hash cache
-            >> out.nonref_expr.ElementPtrIntegers(0, 2).store(native_ast.const_int32_expr(0))  # count
-            >> out.nonref_expr.ElementPtrIntegers(0, 3).store(native_ast.const_int32_expr(1))  # reserved
-            >> out.nonref_expr.ElementPtrIntegers(0, 4).store(
-                runtime_functions.malloc.call(self.underlyingWrapperType.getBytecount())
-            )  # data
+            >> out.nonref_expr.ElementPtrIntegers(0).store(
+                native_ast.Expression.MakeStruct(
+                    args=(
+                        ('refcount', native_ast.const_int_expr(1)),
+                        ('hash_cache', native_ast.const_int32_expr(-1)),
+                        ('count', native_ast.const_int32_expr(0)),
+                        ('reserved', native_ast.const_int32_expr(1)),
+                        ('data', runtime_functions.malloc.call(self.underlyingWrapperType.getBytecount())),
+                    )
+                )
+            )
         )
 
     def convert_setitem(self, context, expr, index, item):

typed_python/compiler/type_wrappers/tuple_of_wrapper.py

@@ -162,16 +162,23 @@ def initializeEmptyListExpr(self, out, length):
                 runtime_functions.malloc.call(native_ast.const_int_expr(28))
                     .cast(self.tupleTypeWrapper.getNativeLayoutType())
             ) >>
-            out.expr.load().ElementPtrIntegers(0, 4).store(
-                runtime_functions.malloc.call(
-                    length.nonref_expr
-                    .mul(native_ast.const_int_expr(self.underlyingWrapperType.getBytecount()))
-                ).cast(native_ast.UInt8Ptr)
-            ) >>
-            out.expr.load().ElementPtrIntegers(0, 0).store(native_ast.const_int_expr(1)) >>
-            out.expr.load().ElementPtrIntegers(0, 1).store(native_ast.const_int32_expr(-1)) >>
-            out.expr.load().ElementPtrIntegers(0, 2).store(native_ast.const_int32_expr(0)) >>
-            out.expr.load().ElementPtrIntegers(0, 3).store(length.nonref_expr.cast(native_ast.Int32))
+            out.expr.load().ElementPtrIntegers(0).store(
+                native_ast.Expression.MakeStruct(
+                    args=(
+                        ('refcount', native_ast.const_int_expr(1)),
+                        ('hash_cache', native_ast.const_int32_expr(-1)),
+                        ('count', native_ast.const_int32_expr(0)),
+                        ('reserved', length.nonref_expr.cast(native_ast.Int32)),
+                        (
+                            'data',
+                            runtime_functions.malloc.call(
+                                length.nonref_expr
+                                .mul(native_ast.const_int_expr(self.underlyingWrapperType.getBytecount()))
+                            )
+                        ),
+                    )
+                )
+            )
         )