From dac9d4767175541aaaaf0e2f873322f5f1db3b0c Mon Sep 17 00:00:00 2001
From: Damien George <damien.p.george@gmail.com>
Date: Thu, 21 Feb 2019 14:07:44 +1100
Subject: [PATCH] py/objgenerator: Fix handling of None passed as 2nd arg to
throw().
Fixes issue #4527.
---
py/objgenerator.c | 17 ++++++++++++++++-
tests/basics/gen_yield_from_throw.py | 22 ++++++++++++++++++++--
tests/basics/generator_throw.py | 14 ++++++++++++--
3 files changed, 48 insertions(+), 5 deletions(-)
diff --git a/py/objgenerator.c b/py/objgenerator.c
index c306bb0c5..92bafea6a 100644
--- a/py/objgenerator.c
+++ b/py/objgenerator.c
@@ -252,7 +252,22 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_2(gen_instance_send_obj, gen_instance_send);
STATIC mp_obj_t gen_instance_close(mp_obj_t self_in);
STATIC mp_obj_t gen_instance_throw(size_t n_args, const mp_obj_t *args) {
- mp_obj_t exc = (n_args == 2) ? args[1] : args[2];
+ // The signature of this function is: throw(type[, value[, traceback]])
+ // CPython will pass all given arguments through the call chain and process them
+ // at the point they are used (native generators will handle them differently to
+ // user-defined generators with a throw() method). To save passing multiple
+ // values, MicroPython instead does partial processing here to reduce it down to
+ // one argument and passes that through:
+ // - if only args[1] is given, or args[2] is given but is None, args[1] is
+ // passed through (in the standard case it is an exception class or instance)
+ // - if args[2] is given and not None it is passed through (in the standard
+ // case it would be an exception instance and args[1] its corresponding class)
+ // - args[3] is always ignored
+
+ mp_obj_t exc = args[1];
+ if (n_args > 2 && args[2] != mp_const_none) {
+ exc = args[2];
+ }
mp_obj_t ret = gen_resume_and_raise(args[0], mp_const_none, exc);
if (ret == MP_OBJ_STOP_ITERATION) {
diff --git a/tests/basics/gen_yield_from_throw.py b/tests/basics/gen_yield_from_throw.py
index 703158f4d..804c53dda 100644
--- a/tests/basics/gen_yield_from_throw.py
+++ b/tests/basics/gen_yield_from_throw.py
@@ -1,8 +1,8 @@
def gen():
try:
yield 1
- except ValueError:
- print("got ValueError from upstream!")
+ except ValueError as e:
+ print("got ValueError from upstream!", repr(e.args))
yield "str1"
raise TypeError
@@ -16,3 +16,21 @@ try:
print(next(g))
except TypeError:
print("got TypeError from downstream!")
+
+# passing None as second argument to throw
+g = gen2()
+print(next(g))
+print(g.throw(ValueError, None))
+try:
+ print(next(g))
+except TypeError:
+ print("got TypeError from downstream!")
+
+# passing an exception instance as second argument to throw
+g = gen2()
+print(next(g))
+print(g.throw(ValueError, ValueError(123)))
+try:
+ print(next(g))
+except TypeError:
+ print("got TypeError from downstream!")
diff --git a/tests/basics/generator_throw.py b/tests/basics/generator_throw.py
index bf5ff33a2..1b43c125e 100644
--- a/tests/basics/generator_throw.py
+++ b/tests/basics/generator_throw.py
@@ -28,8 +28,8 @@ except StopIteration:
def gen():
try:
yield 123
- except GeneratorExit:
- print('GeneratorExit')
+ except GeneratorExit as e:
+ print('GeneratorExit', repr(e.args))
yield 456
# thrown a class
@@ -41,3 +41,13 @@ print(g.throw(GeneratorExit))
g = gen()
print(next(g))
print(g.throw(GeneratorExit()))
+
+# thrown an instance with None as second arg
+g = gen()
+print(next(g))
+print(g.throw(GeneratorExit(), None))
+
+# thrown a class and instance
+g = gen()
+print(next(g))
+print(g.throw(GeneratorExit, GeneratorExit(123)))
--
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