From 000d68443e5935390108827db9892f5ffe175e43 Mon Sep 17 00:00:00 2001
From: Valentin Haenel <vhaenel@anaconda.com>
Date: Tue, 14 Jan 2020 12:28:28 +0100
Subject: [PATCH 1/2] Catch the use of global typed-list in JITed functions

As Numba treats globals as compile time constants, we detect the use of
a global typed-list inside a JITed function early on during
type-inference and emit an appropriate error. The previous behaviour was
to error out during lowering with a less informative error message.

Includes test.

Fixes: 5041
---
 numba/ir_utils.py             |  2 +-
 numba/tests/test_typedlist.py | 25 +++++++++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/numba/ir_utils.py b/numba/ir_utils.py
index 2dea66345a2..5a27b3aea5a 100644
--- a/numba/ir_utils.py
+++ b/numba/ir_utils.py
@@ -1987,7 +1987,7 @@ def raise_on_unsupported_feature(func_ir, typemap):
                        "compile-time constants and there is no known way to "
                        "compile a %s type as a constant.")
                 if (getattr(ty, 'reflected', False) or
-                    isinstance(ty, types.DictType)):
+                    isinstance(ty, (types.DictType, types.ListType))):
                     raise TypingError(msg % (ty, stmt.value.name, ty), loc=stmt.loc)
 
             # checks for generator expressions (yield in use when func_ir has
diff --git a/numba/tests/test_typedlist.py b/numba/tests/test_typedlist.py
index 5fb393a7625..f7cb05ca809 100644
--- a/numba/tests/test_typedlist.py
+++ b/numba/tests/test_typedlist.py
@@ -9,6 +9,7 @@
 from numba import jitclass, typeof
 from numba.typed import List, Dict
 from numba.utils import IS_PY3
+from numba.errors import TypingError
 from .support import (TestCase, MemoryLeakMixin, unittest, override_config,
                       forbid_codegen)
 
@@ -18,6 +19,11 @@
 
 skip_py2 = unittest.skipUnless(IS_PY3, reason='not supported in py2')
 
+# global typed-list for testing purposes
+global_typed_list = List.empty_list(int32)
+for i in (int32(1), int32(2), int32(3)):
+    global_typed_list.append(i)
+
 
 def to_tl(l):
     """ Convert cpython list to typed-list. """
@@ -459,6 +465,25 @@ def test_list_create_no_jit_using_List(self):
                 l = List()
                 self.assertEqual(type(l), list)
 
+    def test_catch_global_typed_list(self):
+        @njit()
+        def foo():
+            x = List()
+            for i in global_typed_list:
+                x.append(i)
+
+        expected_message = ("The use of a ListType[int32] type, assigned to "
+                            "variable 'global_typed_list' in globals, is not "
+                            "supported as globals are considered compile-time "
+                            "constants and there is no known way to compile "
+                            "a ListType[int32] type as a constant.")
+        with self.assertRaises(TypingError) as raises:
+            foo()
+        self.assertIn(
+            expected_message,
+            str(raises.exception),
+        )
+
 
 class TestAllocation(MemoryLeakMixin, TestCase):
 

From 3284d11f46c573849815d699039ab3f799b2d3fb Mon Sep 17 00:00:00 2001
From: Valentin Haenel <vhaenel@anaconda.com>
Date: Wed, 15 Jan 2020 15:31:04 +0100
Subject: [PATCH 2/2] refactor for loop to make it shorter

As title.
---
 numba/tests/test_typedlist.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/numba/tests/test_typedlist.py b/numba/tests/test_typedlist.py
index f7cb05ca809..8c48d199f08 100644
--- a/numba/tests/test_typedlist.py
+++ b/numba/tests/test_typedlist.py
@@ -21,8 +21,8 @@
 
 # global typed-list for testing purposes
 global_typed_list = List.empty_list(int32)
-for i in (int32(1), int32(2), int32(3)):
-    global_typed_list.append(i)
+for i in (1, 2, 3):
+    global_typed_list.append(int32(i))
 
 
 def to_tl(l):