Make gdb.selected_thread().inferior return a new reference
Commit Message
thpy_get_inferior function should return a new reference to the
existing inferior object, and therefore should increment its refcount.
Fixed bug lokks like this.
If multiple time call gdb.selected_thread ().inferior, gdb throws exception:
(gdb) pi gdb.selected_thread().inferior
<gdb.Inferior object at 0x7f1952bea698>
(gdb) pi gdb.selected_thread().inferior
Python Exception <type 'exceptions.AttributeError'> 'NoneType' object
has no attribute 'inferior':
Error while executing Python code.
(gdb) info threads
Id Target Id Frame
* 1 Thread 0x7f54f0474740 (LWP 584) "mc" 0x00007f54ef055c33 in
---
gdb/ChangeLog | 6 ++++++
gdb/python/py-infthread.c | 1 +
gdb/testsuite/ChangeLog | 6 ++++++
gdb/testsuite/gdb.python/py-infthread.exp | 9 +++++++++
4 files changed, 22 insertions(+)
Comments
Thanks! I pushed the patch with the following changes:
On 2017-10-28 14:14, Maksim Dzabraev wrote:
> thpy_get_inferior function should return a new reference to the
> existing inferior object, and therefore should increment its refcount.
>
> Fixed bug lokks like this.
lokks -> looks
> If multiple time call gdb.selected_thread ().inferior, gdb throws
> exception:
> (gdb) pi gdb.selected_thread().inferior
> <gdb.Inferior object at 0x7f1952bea698>
> (gdb) pi gdb.selected_thread().inferior
> Python Exception <type 'exceptions.AttributeError'> 'NoneType' object
> has no attribute 'inferior':
> Error while executing Python code.
> (gdb) info threads
> Id Target Id Frame
> * 1 Thread 0x7f54f0474740 (LWP 584) "mc" 0x00007f54ef055c33 in
> ---
> gdb/ChangeLog | 6 ++++++
> gdb/python/py-infthread.c | 1 +
> gdb/testsuite/ChangeLog | 6 ++++++
> gdb/testsuite/gdb.python/py-infthread.exp | 9 +++++++++
> 4 files changed, 22 insertions(+)
>
> diff --git a/gdb/ChangeLog b/gdb/ChangeLog
> index 9fe632985e..4583a78fe5 100644
> --- a/gdb/ChangeLog
> +++ b/gdb/ChangeLog
> @@ -1,3 +1,9 @@
> +2017-10-28 Maksim Dzabraev <dzabraew@gmail.com>
> +
> + PR python/21213
> + * python/py-infthread.c (thpy_get_inferior): Increment reference
> + of inferior before returning it.
> +
> 2017-10-27 Simon Marchi <simon.marchi@ericsson.com>
>
> * unittests/common-utils-selftests.c (format): Add
> diff --git a/gdb/python/py-infthread.c b/gdb/python/py-infthread.c
> index 626c15cedb..31d576f7c7 100644
> --- a/gdb/python/py-infthread.c
> +++ b/gdb/python/py-infthread.c
> @@ -162,6 +162,7 @@ thpy_get_inferior (PyObject *self, void *ignore)
> thread_object *thread_obj = (thread_object *) self;
>
> THPY_REQUIRE_VALID (thread_obj);
> + Py_INCREF (thread_obj->inf_obj);
>
> return thread_obj->inf_obj;
> }
> diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
> index 0254a28550..72334fd3e2 100644
> --- a/gdb/testsuite/ChangeLog
> +++ b/gdb/testsuite/ChangeLog
> @@ -1,3 +1,9 @@
> +2017-10-28 Maksim Dzabraev <dzabraew@gmail.com>
Used two spaces between fields.
Simon
@@ -1,3 +1,9 @@
+2017-10-28 Maksim Dzabraev <dzabraew@gmail.com>
+
+ PR python/21213
+ * python/py-infthread.c (thpy_get_inferior): Increment reference
+ of inferior before returning it.
+
2017-10-27 Simon Marchi <simon.marchi@ericsson.com>
* unittests/common-utils-selftests.c (format): Add
@@ -162,6 +162,7 @@ thpy_get_inferior (PyObject *self, void *ignore)
thread_object *thread_obj = (thread_object *) self;
THPY_REQUIRE_VALID (thread_obj);
+ Py_INCREF (thread_obj->inf_obj);
return thread_obj->inf_obj;
}
@@ -1,3 +1,9 @@
+2017-10-28 Maksim Dzabraev <dzabraew@gmail.com>
+
+ PR python/21213
+ * gdb.python/py-infthread.exp: Test calling
+ InferiorThread.inferior () multiple times in a row.
+
2017-10-27 Keith Seitz <keiths@redhat.com>
* gdb.opt/inline-break.exp (break_info_1): New procedure.
@@ -51,6 +51,15 @@ gdb_test "python print(seen_a_thread)" "True"
# Test basic gdb.Inferior attributes and methods.
+# Make sure that InferiorThread.inferior returns a new reference (see PR 21213).
+
+gdb_py_test_silent_cmd "python gdb.selected_thread ().inferior" "test InferiorThread.inferior 1" 1
+gdb_py_test_silent_cmd "python gdb.selected_thread ().inferior" "test InferiorThread.inferior 2" 1
+gdb_test_no_output "python import gc; gc.collect()" "call Python garbage collection"
+gdb_py_test_silent_cmd "python gdb.selected_thread ().inferior" "test InferiorThread.inferior 3" 1
+gdb_py_test_silent_cmd "python gdb.selected_thread ().inferior" "test InferiorThread.inferior 4" 1
+
+
gdb_py_test_silent_cmd "python t0 = gdb.selected_thread ()" "test gdb.selected_thread" 1
gdb_test "python print (t0)" "\\<gdb.InferiorThread object at 0x\[\[:xdigit:\]\]+>" "verify InferiorThread object"
gdb_test "python print ('result = %s' % t0.num)" " = 1" "test InferiorThread.num"