[RFC 4/8] mi/python: C++ify python MI command handling code

Jan Vrany
2019-04-18T15:24:04Z

Use gdbpy_ref<> instead of manually calling Py_DECREF().
Use gdb::unique_xmalloc_ptr<> instead of manually calling xfree().

gdb/Changelog:

* python/py-micmd.c (parse_mi_result): Use gdb::unique_xmalloc_ptr<>
instead of manually calling xfree().
(py_mi_invoke): Use gdbpy_ref<> instead of PyObject * with Py_DECREF().
Do not call Py_DECREF() on individual strings in python argument list
object as PyList_SetItem() steals reference.
(micmdpy_parse_command_name): Fix formatting.
(micmdpy_init): Use gdb::unique_xmalloc_ptr<> instead of manually
calling xfree().
---
gdb/ChangeLog | 11 ++++++++++
gdb/python/py-micmd.c | 50 ++++++++++++++++---------------------------
2 files changed, 29 insertions(+), 32 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index ef77fdbb5c..692b937fee 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,14 @@
+2018-12-11 Jan Vrany <jan.vrany@fit.cvut.cz>
+
+ * python/py-micmd.c (parse_mi_result): Use gdb::unique_xmalloc_ptr<>
+ instead of manually calling xfree().
+ (py_mi_invoke): Use gdbpy_ref<> instead of PyObject * with Py_DECREF().
+ Do not call Py_DECREF() on individual strings in python argument list
+ object as PyList_SetItem() steals reference.
+ (micmdpy_parse_command_name): Fix formatting.
+ (micmdpy_init): Use gdb::unique_xmalloc_ptr<> instead of manually
+ calling xfree().
+
2019-04-17 Tom Tromey <tromey@adacore.com>

* dwarf2read.c (dwarf2_init_complex_target_type): Check "tt"
diff --git a/gdb/python/py-micmd.c b/gdb/python/py-micmd.c
index ee612e2bc5..0683a02017 100644
--- a/gdb/python/py-micmd.c
+++ b/gdb/python/py-micmd.c
@@ -53,11 +53,9 @@ parse_mi_result (PyObject *result, const char *field_name)
ui_out_emit_list list_emitter (uiout, field_name);
for(i = 0; i < PyList_GET_SIZE (result); ++i)
{
- //struct cleanup *cleanup_item = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
ui_out_emit_tuple tuple_emitter (uiout, NULL);
item = PyList_GetItem (result, i);
parse_mi_result (item, NULL);
- //do_cleanups (cleanup_item);
}
}
else if ( PyDict_Check (result))
@@ -66,9 +64,8 @@ parse_mi_result (PyObject *result, const char *field_name)
Py_ssize_t pos = 0;
while ( PyDict_Next (result, &pos, &key, &value) )
{
- char *key_string = gdbpy_obj_to_string (key).release ();
- parse_mi_result (value, key_string);
- xfree ( (void *) key_string);
+ gdb::unique_xmalloc_ptr<char> key_string (gdbpy_obj_to_string (key));
+ parse_mi_result (value, key_string.get ());
}
}
}
@@ -79,7 +76,6 @@ void
py_mi_invoke (void *py_obj, char **argv, int argc)
{
micmdpy_object *obj = (micmdpy_object *) py_obj;
- PyObject *argobj, *result, **strings;
int i;

gdbpy_enter enter_py (get_current_arch (), current_language);
@@ -92,9 +88,8 @@ py_mi_invoke (void *py_obj, char **argv, int argc)
error (_("Python command object missing 'invoke' method."));
}

- strings = (PyObject **) malloc (sizeof(PyObject *) * argc);
- argobj = PyList_New (argc);
- if ( !argobj)
+ gdbpy_ref<> argobj (PyList_New (argc));
+ if (argobj == nullptr)
{
gdbpy_print_stack ();
error (_("Failed to create the python arguments list."));
@@ -102,28 +97,22 @@ py_mi_invoke (void *py_obj, char **argv, int argc)

for (i = 0; i < argc; ++i)
{
- strings[i] = PyUnicode_Decode (argv[i], strlen(argv[i]), host_charset (), NULL);
- if (PyList_SetItem (argobj, i, strings[i]) != 0)
+ /* Since PyList_SetItem steals the reference, we don't use
+ * gdbpy_ref<> to hold on arg string. */
+ PyObject* str = PyUnicode_Decode (argv[i], strlen (argv[i]), host_charset (), NULL);
+ if (PyList_SetItem (argobj.get (), i, str) != 0)
{
error (_("Failed to create the python arguments list."));
}
}

- result = PyObject_CallMethodObjArgs ((PyObject *) obj, invoke_cst, argobj,
- NULL);
+ gdbpy_ref<> result (PyObject_CallMethodObjArgs ((PyObject *) obj, invoke_cst, argobj.get (),
+ NULL));

- if (result)
+ if (result != nullptr)
{
- parse_mi_result (result, NULL);
- Py_DECREF (result);
+ parse_mi_result (result.get (), NULL);
}
-
- Py_DECREF (argobj);
- for (i = 0; i < argc; ++i)
- {
- Py_DECREF (strings[i]);
- }
- free (strings);
}

/* Parse the name of the MI command to register.
@@ -150,7 +139,7 @@ micmdpy_parse_command_name (const char *name)

/* Skip preceding whitespaces. */
/* Find first character of the final word. */
- for (; i > 0 && (isalnum (name[i - 1])
+ for (; i > 0 && (isalnum (name[i - 1])
|| name[i - 1] == '-'
|| name[i - 1] == '_');
--i)
@@ -158,10 +147,10 @@ micmdpy_parse_command_name (const char *name)
/* Skip the first dash to have to command name only.
* i.e. -thread-info -> thread-info
*/
- if(name[i] == '-' && i < len - 2)
+ if(name[i] == '-' && i < len - 2)
i++;

- if( i == lastchar)
+ if( i == lastchar)
{
PyErr_SetString (PyExc_RuntimeError, _("No command name found."));
return NULL;
@@ -185,20 +174,19 @@ static int
micmdpy_init (PyObject *self, PyObject *args, PyObject *kw)
{
const char *name;
- char *cmd_name;

if(! PyArg_ParseTuple (args, "s", &name))
return -1;

- cmd_name = micmdpy_parse_command_name (name);
- if (! cmd_name)
+ gdb::unique_xmalloc_ptr<char> cmd_name (micmdpy_parse_command_name (name));
+ if (cmd_name == nullptr)
return -1;

Py_INCREF (self);

try
{
- mi_command *micommand = new mi_command_py (cmd_name, NULL, (void *) self);
+ mi_command *micommand = new mi_command_py (cmd_name.get (), NULL, (void *) self);

bool result = insert_mi_cmd_entry (mi_cmd_up (micommand));

@@ -211,7 +199,6 @@ micmdpy_init (PyObject *self, PyObject *args, PyObject *kw)
}
catch (const gdb_exception &except)
{
- xfree (cmd_name);
Py_DECREF (self);
PyErr_Format (except.reason == RETURN_QUIT
? PyExc_KeyboardInterrupt : PyExc_RuntimeError,
@@ -219,7 +206,6 @@ micmdpy_init (PyObject *self, PyObject *args, PyObject *kw)
return -1;
}

- xfree (cmd_name);
return 0;
}

--
2.20.1