[PATCHv4 3/4] gdb/python: add gdb.RemoteTargetConnection.send_packet
Andrew Burgess
andrew.burgess@embecosm.com
Fri Oct 22 10:58:54 GMT 2021
This commits adds a new sub-class of gdb.TargetConnection,
gdb.RemoteTargetConnection. This sub-class is created for all
'remote' and 'extended-remote' targets.
This new sub-class has one additional method over its base class,
'send_packet'. This new method is equivalent to the 'maint
packet' CLI command, it allows a custom packet to be sent to a remote
target.
The result of calling RemoteTargetConnection.send_packet is a string
containing the reply that came from the remote.
---
gdb/NEWS | 8 +-
gdb/doc/gdb.texinfo | 1 +
gdb/doc/python.texi | 40 ++++-
gdb/python/py-connection.c | 174 +++++++++++++++++++-
gdb/testsuite/gdb.python/py-connection.exp | 14 +-
gdb/testsuite/gdb.python/py-send-packet.c | 22 +++
gdb/testsuite/gdb.python/py-send-packet.exp | 56 +++++++
gdb/testsuite/gdb.python/py-send-packet.py | 81 +++++++++
8 files changed, 385 insertions(+), 11 deletions(-)
create mode 100644 gdb/testsuite/gdb.python/py-send-packet.c
create mode 100644 gdb/testsuite/gdb.python/py-send-packet.exp
create mode 100644 gdb/testsuite/gdb.python/py-send-packet.py
diff --git a/gdb/NEWS b/gdb/NEWS
index 3bd13993005..a2d3505d14e 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -46,7 +46,9 @@ maint show internal-warning backtrace
before GDB starts to clean up its internal state.
** New gdb.TargetConnection object type that represents a connection
- (as displayed by the 'info connections' command).
+ (as displayed by the 'info connections' command). A sub-class,
+ gdb.RemoteTargetConnection, is used to represent 'remote' and
+ 'extended-remote' connections.
** The gdb.Inferior type now has a 'connection' property which is an
instance of gdb.TargetConnection, the connection used by this
@@ -60,6 +62,10 @@ maint show internal-warning backtrace
** New gdb.connections() function that returns a list of all
currently active connections.
+ ** New gdb.RemoteTargetConnection.send_packet(STRING) method. This
+ is equivalent to the existing 'maint packet' CLI command; it
+ allows a user specified packet to be sent to the remote target.
+
*** Changes in GDB 11
* The 'set disassembler-options' command now supports specifying options
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 631a7c03b31..89cf86210ab 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -39269,6 +39269,7 @@
error stream. This is @samp{on} by default for @code{internal-error}
and @samp{off} by default for @code{internal-warning}.
+@anchor{maint packet}
@kindex maint packet
@item maint packet @var{text}
If @value{GDBN} is talking to an inferior via the serial protocol,
diff --git a/gdb/doc/python.texi b/gdb/doc/python.texi
index e62e2703b85..587cc934ca4 100644
--- a/gdb/doc/python.texi
+++ b/gdb/doc/python.texi
@@ -5980,9 +5980,9 @@
Examples of different connection types are @samp{native} and
@samp{remote}. @xref{Inferiors Connections and Programs}.
-@value{GDBN} uses the @code{gdb.TargetConnection} object type to
-represent a connection in Python code. To get a list of all
-connections use @code{gdb.connections}
+Connections in @value{GDBN} are represented as instances of
+@code{gdb.TargetConnection}, or as one of its sub-classes. To get a
+list of all connections use @code{gdb.connections}
(@pxref{gdbpy_connections,,gdb.connections}).
To get the connection for a single @code{gdb.Inferior} read its
@@ -6035,6 +6035,40 @@
to the remote target.
@end defvar
+The @code{gdb.RemoteTargetConnection} class is a sub-class of
+@code{gdb.TargetConnection}, and is used to represent @samp{remote}
+and @samp{extended-remote} connections. In addition to the attributes
+and methods available from the @code{gdb.TargetConnection} base class,
+a @code{gdb.RemoteTargetConnection} has the following method:
+
+@kindex maint packet
+@defun RemoteTargetConnection.send_packet (@var{packet})
+This method sends @var{packet}, which should be a non-empty string, to
+the remote target and returns the response. If @var{packet} is not a
+string, or is the empty string, then an exception of type
+@code{ValueError} is thrown.
+
+In Python 3, the response is returned as a @code{bytes} buffer, if it
+is known that the response can be represented as a string then this
+can be decoded from the buffer. For example, if it is known that the
+response is an @code{"ascii"} string:
+
+@smallexample
+remote_connection.send_packet("some_packet").decode("ascii")
+@end smallexample
+
+In Python 2, the response is returned as a @code{str}, which may
+contain non-printable characters.
+
+The prefix, suffix, and checksum (as required by the remote serial
+protocol) are automatically added to the outgoing packet, and removed
+from the incoming packet before the contents of the reply are
+returned.
+
+This is equivalent to the @code{maintenance packet} command
+(@pxref{maint packet}).
+@end defun
+
@node TUI Windows In Python
@subsubsection Implementing new TUI windows
@cindex Python TUI Windows
diff --git a/gdb/python/py-connection.c b/gdb/python/py-connection.c
index f1dfa26e39c..f47182d720e 100644
--- a/gdb/python/py-connection.c
+++ b/gdb/python/py-connection.c
@@ -26,6 +26,8 @@
#include "py-events.h"
#include "py-event.h"
#include "arch-utils.h"
+#include "remote.h"
+#include "charset.h"
#include <map>
@@ -47,6 +49,9 @@ struct connection_object
extern PyTypeObject connection_object_type
CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("connection_object");
+extern PyTypeObject remote_connection_object_type
+ CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("remote_connection_object");
+
/* Require that CONNECTION be valid. */
#define CONNPY_REQUIRE_VALID(connection) \
do { \
@@ -81,8 +86,15 @@ target_to_connection_object (process_stratum_target *target)
auto conn_obj_iter = all_connection_objects.find (target);
if (conn_obj_iter == all_connection_objects.end ())
{
- conn_obj.reset (PyObject_New (connection_object,
- &connection_object_type));
+ PyTypeObject *type;
+
+ std::string connection_type = target->shortname ();
+ if (connection_type == "remote" || connection_type == "extended-remote")
+ type = &remote_connection_object_type;
+ else
+ type = &connection_object_type;
+
+ conn_obj.reset (PyObject_New (connection_object, type));
if (conn_obj == nullptr)
return nullptr;
conn_obj->target = target;
@@ -284,9 +296,111 @@ gdbpy_initialize_connection (void)
(PyObject *) &connection_object_type) < 0)
return -1;
+ if (PyType_Ready (&remote_connection_object_type) < 0)
+ return -1;
+
+ if (gdb_pymodule_addobject (gdb_module, "RemoteTargetConnection",
+ (PyObject *) &remote_connection_object_type) < 0)
+ return -1;
+
return 0;
}
+/* Set of callbacks used to implement gdb.send_packet. */
+
+struct py_send_packet_callbacks : public send_remote_packet_callbacks
+{
+ /* Constructor, initialise the result to None. */
+
+ py_send_packet_callbacks ()
+ : m_result (Py_None)
+ { /* Nothing. */ }
+
+ /* There's nothing to do when the packet is sent. */
+
+ void sending (const char *args) override
+ { /* Nothing. */ }
+
+ /* When the result is returned create a Python string and assign this
+ into the result member variable. */
+
+ void received (const gdb::char_vector &buf) override
+ {
+ /* m_result is initialized to None, leave it untouched unless we got
+ back a useful result. */
+ if (buf.data ()[0] != '\0')
+ {
+ PyObject *result;
+
+#ifdef IS_PY3K
+ result = Py_BuildValue("y#", buf.data (), strlen (buf.data ()));
+#else
+ result = PyString_FromStringAndSize (buf.data (),
+ strlen (buf.data ()));
+#endif
+
+ if (result != nullptr)
+ m_result = gdbpy_ref<> (result);
+ }
+ }
+
+ /* Get a reference to the result as a Python object. */
+
+ gdbpy_ref<> result () const
+ {
+ return m_result;
+ }
+
+private:
+
+ /* A reference to a valid result value. This is initialized in the
+ constructor, and so will always point to a valid value, even if this
+ is just None. */
+
+ gdbpy_ref<> m_result;
+};
+
+/* Implement RemoteTargetConnection.send_packet function. Send a packet to
+ the target identified by SELF. The connection must still be valid, and
+ the packet to be sent must be non-empty, otherwise an exception will be
+ thrown. */
+
+static PyObject *
+connpy_send_packet (PyObject *self, PyObject *args, PyObject *kw)
+{
+ connection_object *conn = (connection_object *) self;
+
+ CONNPY_REQUIRE_VALID (conn);
+
+ static const char *keywords[] = {"packet", nullptr};
+ const char *packet_str = nullptr;
+
+ if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "s", keywords,
+ &packet_str))
+ return nullptr;
+
+ if (packet_str == nullptr || *packet_str == '\0')
+ {
+ PyErr_SetString (PyExc_ValueError, _("Invalid remote packet"));
+ return nullptr;
+ }
+
+ try
+ {
+ scoped_restore_current_thread restore_thread;
+ switch_to_target_no_thread (conn->target);
+
+ py_send_packet_callbacks callbacks;
+ send_remote_packet (packet_str, &callbacks);
+ return callbacks.result ().release ();
+ }
+ catch (const gdb_exception &except)
+ {
+ gdbpy_convert_exception (except);
+ return nullptr;
+ }
+}
+
/* Global initialization for this file. */
void _initialize_py_connection ();
@@ -307,6 +421,17 @@ Return true if this TargetConnection is valid, false if not." },
{ NULL }
};
+/* Methods for the gdb.RemoteTargetConnection object type. */
+
+static PyMethodDef remote_connection_object_methods[] =
+{
+ { "send_packet", (PyCFunction) connpy_send_packet,
+ METH_VARARGS | METH_KEYWORDS,
+ "send_packet (PACKET) -> String\n\
+Send PACKET to a remote target, return the reply as a string." },
+ { NULL }
+};
+
/* Attributes for the gdb.TargetConnection object type. */
static gdb_PyGetSetDef connection_object_getset[] =
@@ -345,7 +470,7 @@ PyTypeObject connection_object_type =
0, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
- Py_TPFLAGS_DEFAULT, /* tp_flags */
+ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
"GDB target connection object", /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
@@ -364,3 +489,46 @@ PyTypeObject connection_object_type =
0, /* tp_init */
0 /* tp_alloc */
};
+
+/* Define the gdb.RemoteTargetConnection object type. */
+
+PyTypeObject remote_connection_object_type =
+{
+ PyVarObject_HEAD_INIT (NULL, 0)
+ "gdb.RemoteTargetConnection", /* tp_name */
+ sizeof (connection_object), /* tp_basicsize */
+ 0, /* tp_itemsize */
+ connpy_connection_dealloc, /* tp_dealloc */
+ 0, /* tp_print */
+ 0, /* tp_getattr */
+ 0, /* tp_setattr */
+ 0, /* tp_compare */
+ connpy_repr, /* tp_repr */
+ 0, /* tp_as_number */
+ 0, /* tp_as_sequence */
+ 0, /* tp_as_mapping */
+ 0, /* tp_hash */
+ 0, /* tp_call */
+ 0, /* tp_str */
+ 0, /* tp_getattro */
+ 0, /* tp_setattro */
+ 0, /* tp_as_buffer */
+ Py_TPFLAGS_DEFAULT, /* tp_flags */
+ "GDB remote target connection object", /* tp_doc */
+ 0, /* tp_traverse */
+ 0, /* tp_clear */
+ 0, /* tp_richcompare */
+ 0, /* tp_weaklistoffset */
+ 0, /* tp_iter */
+ 0, /* tp_iternext */
+ remote_connection_object_methods, /* tp_methods */
+ 0, /* tp_members */
+ 0, /* tp_getset */
+ &connection_object_type, /* tp_base */
+ 0, /* tp_dict */
+ 0, /* tp_descr_get */
+ 0, /* tp_descr_set */
+ 0, /* tp_dictoffset */
+ 0, /* tp_init */
+ 0 /* tp_alloc */
+};
diff --git a/gdb/testsuite/gdb.python/py-connection.exp b/gdb/testsuite/gdb.python/py-connection.exp
index b805b052f73..96c83781839 100644
--- a/gdb/testsuite/gdb.python/py-connection.exp
+++ b/gdb/testsuite/gdb.python/py-connection.exp
@@ -33,12 +33,18 @@ if ![runto_main] then {
return 0
}
+if { [target_info exists gdb_protocol] } {
+ set connection_type "RemoteTargetConnection"
+} else {
+ set connection_type "TargetConnection"
+}
+
# Create a gdb.TargetConnection object and check it is initially
# valid.
gdb_test_no_output "python conn = gdb.selected_inferior().connection"
gdb_test "python print(conn)" \
- "<gdb.TargetConnection num=1, what=\"\[^\"\]+\">" \
- "print gdb.TargetConnection while it is still valid"
+ "<gdb.${connection_type} num=1, what=\"\[^\"\]+\">" \
+ "print gdb.${connection_type} while it is still valid"
gdb_test "python print(conn.is_valid())" "True" "is_valid returns True"
# Get the connection again, and ensure we get the exact same object.
@@ -53,8 +59,8 @@ gdb_test "disconnect" "" "kill the inferior" \
"A program is being debugged already\\. Kill it\\? .*y or n. $" "y"
gdb_test "info connections" "No connections\\." \
"info connections now all the connections have gone"
-gdb_test "python print(conn)" "<gdb.TargetConnection \\(invalid\\)>" \
- "print gdb.TargetConnection now its invalid"
+gdb_test "python print(conn)" "<gdb.${connection_type} \\(invalid\\)>" \
+ "print gdb.${connection_type} now its invalid"
gdb_test "python print(conn.is_valid())" "False" "is_valid returns False"
# Now check that accessing properties of the invalid connection cases
diff --git a/gdb/testsuite/gdb.python/py-send-packet.c b/gdb/testsuite/gdb.python/py-send-packet.c
new file mode 100644
index 00000000000..bfe52c018d4
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-send-packet.c
@@ -0,0 +1,22 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2021 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+int
+main (void)
+{
+ return 0;
+}
diff --git a/gdb/testsuite/gdb.python/py-send-packet.exp b/gdb/testsuite/gdb.python/py-send-packet.exp
new file mode 100644
index 00000000000..dde5c270f20
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-send-packet.exp
@@ -0,0 +1,56 @@
+# Copyright (C) 2021 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+# Test the gdb.RemoteTargetConnection.send_packet API. This is done
+# by connecting to a remote target and fetching the thread list in two
+# ways, first, we manually send the packets required to read the
+# thread list using gdb.TargetConnection.send_packet, then we compare
+# the results to the thread list using the standard API calls.
+
+load_lib gdb-python.exp
+load_lib gdbserver-support.exp
+
+standard_testfile
+
+if {[skip_gdbserver_tests]} {
+ return 0
+}
+
+if { [prepare_for_testing "failed to prepare" ${testfile} ${srcfile}] } {
+ return -1
+}
+
+if { [skip_python_tests] } {
+ return 0
+}
+
+# Make sure we're disconnected, in case we're testing with an
+# extended-remote board, therefore already connected.
+gdb_test "disconnect" ".*"
+
+gdbserver_run ""
+
+# Source the python script.
+set remote_python_file [gdb_remote_download host \
+ ${srcdir}/${subdir}/${testfile}.py]
+gdb_test "source $remote_python_file" "Sourcing complete\\." \
+ "source ${testfile}.py script"
+
+# The test is actually written in the Python script. Run it now.
+gdb_test "python run_send_packet_test()" "Send packet test passed"
+
+# Check the string representation of a remote target connection.
+gdb_test "python print(gdb.selected_inferior().connection)" \
+ "<gdb.RemoteTargetConnection num=$decimal, what=\".*\">"
diff --git a/gdb/testsuite/gdb.python/py-send-packet.py b/gdb/testsuite/gdb.python/py-send-packet.py
new file mode 100644
index 00000000000..35754164a98
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-send-packet.py
@@ -0,0 +1,81 @@
+# Copyright (C) 2021 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+import xml.etree.ElementTree as ET
+import gdb
+
+# Make use of gdb.RemoteTargetConnection.send_packet to fetch the
+# thread list from the remote target.
+#
+# Sending existing serial protocol packets like this is not a good
+# idea, there should be better ways to get this information using an
+# official API, this is just being used as a test case.
+#
+# Really, the send_packet API would be used to send target
+# specific packets to the target, but these are, by definition, target
+# specific, so hard to test in a general testsuite.
+def get_thread_list_str():
+ start_pos = 0
+ thread_desc = ""
+ conn = gdb.selected_inferior().connection
+ if not isinstance(conn, gdb.RemoteTargetConnection):
+ raise gdb.GdbError("connection is the wrong type")
+ while True:
+ str = conn.send_packet("qXfer:threads:read::%d,200" % start_pos).decode("ascii")
+ start_pos += 200
+ c = str[0]
+ str = str[1:]
+ thread_desc += str
+ if c == "l":
+ break
+ return thread_desc
+
+
+# Use gdb.RemoteTargetConnection.send_packet to manually fetch the
+# thread list, then extract the thread list using the gdb.Inferior and
+# gdb.InferiorThread API. Compare the two results to ensure we
+# managed to successfully read the thread list from the remote.
+def run_send_packet_test():
+ # Find the IDs of all current threads.
+ all_threads = {}
+ for inf in gdb.inferiors():
+ for thr in inf.threads():
+ id = "p%x.%x" % (thr.ptid[0], thr.ptid[1])
+ all_threads[id] = False
+
+ # Now fetch the thread list from the remote, and parse the XML.
+ str = get_thread_list_str()
+ threads_xml = ET.fromstring(str)
+
+ # Look over all threads in the XML list and check we expected to
+ # find them, mark the ones we do find.
+ for thr in threads_xml:
+ id = thr.get("id")
+ if not id in all_threads:
+ raise "found unexpected thread in remote thread list"
+ else:
+ all_threads[id] = True
+
+ # Check that all the threads were found in the XML list.
+ for id in all_threads:
+ if not all_threads[id]:
+ raise "thread missingt from remote thread list"
+
+ # Test complete.
+ print("Send packet test passed")
+
+
+# Just to indicate the file was sourced correctly.
+print("Sourcing complete.")
--
2.25.4
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