[binutils-gdb] gdb: cast all Python extension objects passed to gdbpy_ref_policy to PyObject*
Matthieu Longo
mlongo@sourceware.org
Thu Jan 29 16:46:55 GMT 2026
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=1fe7c3b74924ab69da0469fd93a9de089843e65d
commit 1fe7c3b74924ab69da0469fd93a9de089843e65d
Author: Matthieu Longo <matthieu.longo@arm.com>
Date: Sat Oct 25 23:55:29 2025 +0100
gdb: cast all Python extension objects passed to gdbpy_ref_policy to PyObject*
When enabling the Python limited API, pointers to Python C extension
objects can no longer be implicitly converted to 'PyObject *' by the
compiler.
gdbpy_ref_policy is a templated class that provides a generic interface
for incrementing and decrementing the reference counter on the given
object. It is used as a specialisation of the policy parameter in
gdb::ref_ptr, together with PyObject as the parameter type. As a result,
gdbpy_ref_policy always expects an argument derived from PyObject.
This patch fixes the resulting compilation issue by adding an explicit
static_cast to 'PyObject *' before passing the value to Py_INCREF and
Py_DECREF. As a side effect, these casts enforce, at compile time, that
the template type passed to gdbpy_ref_policy is a subclass of PyObject.
To provide a clearer diagnostic when an incorrect type is used, a
static_assert is added to gdbpy_ref_policy, avoiding obscure errors
originating from the static_cast. Finally, all C Python extension types
passed to gdbpy_ref_policy are updated to inherit from PyObject.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=23830
Approved-By: Tom Tromey <tom@tromey.com>
Diff:
---
gdb/python/py-breakpoint.c | 4 +---
gdb/python/py-cmd.c | 4 +---
gdb/python/py-color.c | 4 +---
gdb/python/py-connection.c | 4 +---
gdb/python/py-corefile.c | 8 ++------
gdb/python/py-disasm.c | 8 ++------
gdb/python/py-events.h | 4 +---
gdb/python/py-frame.c | 4 ++--
gdb/python/py-membuf.c | 5 ++---
gdb/python/py-micmd.c | 4 +---
gdb/python/py-ref.h | 7 +++++--
gdb/python/py-registers.c | 10 ++++------
gdb/python/py-tui.c | 4 +---
gdb/python/python-internal.h | 4 +---
14 files changed, 25 insertions(+), 49 deletions(-)
diff --git a/gdb/python/py-breakpoint.c b/gdb/python/py-breakpoint.c
index fc53213966a..408d4b9d857 100644
--- a/gdb/python/py-breakpoint.c
+++ b/gdb/python/py-breakpoint.c
@@ -37,10 +37,8 @@
extern PyTypeObject breakpoint_location_object_type;
-struct gdbpy_breakpoint_location_object
+struct gdbpy_breakpoint_location_object : public PyObject
{
- PyObject_HEAD
-
/* An owning reference to the gdb breakpoint location object. */
bp_location *bp_loc;
diff --git a/gdb/python/py-cmd.c b/gdb/python/py-cmd.c
index 6b40b1796c6..3fbc26b0cde 100644
--- a/gdb/python/py-cmd.c
+++ b/gdb/python/py-cmd.c
@@ -50,10 +50,8 @@ static const struct cmdpy_completer completers[] =
/* A gdb command. For the time being only ordinary commands (not
set/show commands) are allowed. */
-struct cmdpy_object
+struct cmdpy_object : public PyObject
{
- PyObject_HEAD
-
/* The corresponding gdb command object, or NULL if the command is
no longer installed. */
struct cmd_list_element *command;
diff --git a/gdb/python/py-color.c b/gdb/python/py-color.c
index b41dff2edd7..0bec51b1e52 100644
--- a/gdb/python/py-color.c
+++ b/gdb/python/py-color.c
@@ -37,10 +37,8 @@ static struct {
};
/* A color. */
-struct colorpy_object
+struct colorpy_object : public PyObject
{
- PyObject_HEAD
-
/* Underlying value. */
ui_file_style::color color;
};
diff --git a/gdb/python/py-connection.c b/gdb/python/py-connection.c
index bef50b07f18..e2c29f6f180 100644
--- a/gdb/python/py-connection.c
+++ b/gdb/python/py-connection.c
@@ -31,10 +31,8 @@
/* The Python object that represents a connection. */
-struct connection_object
+struct connection_object : public PyObject
{
- PyObject_HEAD
-
/* The process target that represents this connection. When a
connection_object is created this field will always point at a valid
target. Later, if GDB stops using this target (the target is popped
diff --git a/gdb/python/py-corefile.c b/gdb/python/py-corefile.c
index 24b573b2dbd..88fedbd718c 100644
--- a/gdb/python/py-corefile.c
+++ b/gdb/python/py-corefile.c
@@ -45,10 +45,8 @@ extern PyTypeObject corefile_object_type;
/* A gdb.CorefileMapped object. */
-struct corefile_mapped_file_object
+struct corefile_mapped_file_object : public PyObject
{
- PyObject_HEAD
-
/* The name of a file that was mapped when the core file was created.
This is a 'str' object. */
PyObject *filename;
@@ -70,10 +68,8 @@ extern PyTypeObject corefile_mapped_file_object_type;
/* A gdb.CorefileMappedFileRegion object. */
-struct corefile_mapped_file_region_object
+struct corefile_mapped_file_region_object : public PyObject
{
- PyObject_HEAD
-
/* The start and end addresses for this mapping, these are addresses
within the inferior's address space. */
CORE_ADDR start;
diff --git a/gdb/python/py-disasm.c b/gdb/python/py-disasm.c
index c1aa4d0586a..a125907948c 100644
--- a/gdb/python/py-disasm.c
+++ b/gdb/python/py-disasm.c
@@ -28,10 +28,8 @@
/* Implement gdb.disassembler.DisassembleInfo type. An object of this type
represents a single disassembler request from GDB. */
-struct disasm_info_object
+struct disasm_info_object : public PyObject
{
- PyObject_HEAD
-
/* The architecture in which we are disassembling. */
struct gdbarch *gdbarch;
@@ -99,10 +97,8 @@ extern PyTypeObject disasm_part_object_type;
the disassembled instruction (in bytes), and the string representing the
disassembled instruction. */
-struct disasm_result_object
+struct disasm_result_object : public PyObject
{
- PyObject_HEAD
-
/* The length of the disassembled instruction in bytes. */
int length;
diff --git a/gdb/python/py-events.h b/gdb/python/py-events.h
index 9fc7a86920e..e44b4b4a761 100644
--- a/gdb/python/py-events.h
+++ b/gdb/python/py-events.h
@@ -27,10 +27,8 @@
/* Stores a list of objects to be notified when the event for which this
registry tracks occurs. */
-struct eventregistry_object
+struct eventregistry_object : public PyObject
{
- PyObject_HEAD
-
PyObject *callbacks;
};
diff --git a/gdb/python/py-frame.c b/gdb/python/py-frame.c
index 027ccb4112d..ab7883b4e73 100644
--- a/gdb/python/py-frame.c
+++ b/gdb/python/py-frame.c
@@ -28,8 +28,8 @@
#include "symfile.h"
#include "objfiles.h"
-struct frame_object {
- PyObject_HEAD
+struct frame_object : public PyObject
+{
struct frame_id frame_id;
struct gdbarch *gdbarch;
diff --git a/gdb/python/py-membuf.c b/gdb/python/py-membuf.c
index 832ab62cf52..e3bf5e2ceab 100644
--- a/gdb/python/py-membuf.c
+++ b/gdb/python/py-membuf.c
@@ -19,9 +19,8 @@
#include "python-internal.h"
-struct membuf_object {
- PyObject_HEAD
-
+struct membuf_object : public PyObject
+{
/* Pointer to the raw data, and array of gdb_bytes. */
void *buffer;
diff --git a/gdb/python/py-micmd.c b/gdb/python/py-micmd.c
index c6a96dc3ad5..0c820751c56 100644
--- a/gdb/python/py-micmd.c
+++ b/gdb/python/py-micmd.c
@@ -55,10 +55,8 @@ struct mi_command_py;
/* Representation of a Python gdb.MICommand object. */
-struct micmdpy_object
+struct micmdpy_object : public PyObject
{
- PyObject_HEAD
-
/* The object representing this command in the MI command table. This
pointer can be nullptr if the command is not currently installed into
the MI command table (see gdb.MICommand.installed property). */
diff --git a/gdb/python/py-ref.h b/gdb/python/py-ref.h
index 4d44ca90e21..1d07eeb3dc9 100644
--- a/gdb/python/py-ref.h
+++ b/gdb/python/py-ref.h
@@ -26,14 +26,17 @@
template<typename T>
struct gdbpy_ref_policy
{
+ static_assert(std::is_base_of<PyObject, T>::value,
+ "T must be a subclass of PyObject");
+
static void incref (T *ptr)
{
- Py_INCREF (ptr);
+ Py_INCREF (static_cast<PyObject *> (ptr));
}
static void decref (T *ptr)
{
- Py_DECREF (ptr);
+ Py_DECREF (static_cast<PyObject *> (ptr));
}
};
diff --git a/gdb/python/py-registers.c b/gdb/python/py-registers.c
index ac7480caea9..3d1683805d1 100644
--- a/gdb/python/py-registers.c
+++ b/gdb/python/py-registers.c
@@ -49,9 +49,8 @@ struct register_descriptor_iterator_object {
extern PyTypeObject register_descriptor_iterator_object_type;
/* A register descriptor. */
-struct register_descriptor_object {
- PyObject_HEAD
-
+struct register_descriptor_object : public PyObject
+{
/* The register this is a descriptor for. */
int regnum;
@@ -75,9 +74,8 @@ struct reggroup_iterator_object {
extern PyTypeObject reggroup_iterator_object_type;
/* A register group object. */
-struct reggroup_object {
- PyObject_HEAD
-
+struct reggroup_object : public PyObject
+{
/* The register group being described. */
const struct reggroup *reggroup;
};
diff --git a/gdb/python/py-tui.c b/gdb/python/py-tui.c
index 578ddfbcc67..be19193770f 100644
--- a/gdb/python/py-tui.c
+++ b/gdb/python/py-tui.c
@@ -44,10 +44,8 @@ class tui_py_window;
/* A PyObject representing a TUI window. */
-struct gdbpy_tui_window
+struct gdbpy_tui_window: public PyObject
{
- PyObject_HEAD
-
/* The TUI window, or nullptr if the window has been deleted. */
tui_py_window *window;
diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h
index f6915a62b7a..722edbd1a1c 100644
--- a/gdb/python/python-internal.h
+++ b/gdb/python/python-internal.h
@@ -350,10 +350,8 @@ extern PyTypeObject thread_object_type;
extern bool gdbpy_breakpoint_init_breakpoint_type ();
-struct gdbpy_breakpoint_object
+struct gdbpy_breakpoint_object : public PyObject
{
- PyObject_HEAD
-
/* The breakpoint number according to gdb. */
int number;
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