From: Andrew Burgess <aburgess@redhat.com>
To: gdb-patches@sourceware.org
Subject: [PATCH 1/3] gdb/python: break dependencies between gdbpy_initialize_* functions
Date: Sun, 2 Oct 2022 17:53:03 +0100 [thread overview]
Message-ID: <5353d718bda4d304a38d1b29ae7ce6d455614acd.1664729134.git.aburgess@redhat.com> (raw)
In-Reply-To: <cover.1664729134.git.aburgess@redhat.com>
In a later commit in this series I will propose removing all of the
explicit gdbpy_initialize_* calls from python.c and replace these
calls with a more generic mechanism.
One of the side effects of this generic mechanism is that the order in
which the various Python sub-systems within GDB are initialized is no
longer guaranteed.
On the whole I don't think this matters, most of the sub-systems are
independent of each other, though testing did reveal a few places
where we did have dependencies, though I don't think those
dependencies were explicitly documented in a comment anywhere.
This commit removes the first dependency issue, with this and the next
commit, all of the implicit inter-sub-system dependencies will be
replaced by explicit dependencies, which will allow me to, I think,
clean up how the sub-systems are initialized.
The dependency is around the py_insn_type. This type is setup in
gdbpy_initialize_instruction and used in gdbpy_initialize_record.
Rather than depend on the calls to these two functions being in a
particular order, in this commit I propose adding a new function
py_insn_get_insn_type. This function will take care of setting up the
py_insn_type type and calling PyType_Ready. This helper function can
be called from gdbpy_initialize_record and
gdbpy_initialize_instruction, and the py_insn_type will be initialized
just once.
To me this is better, the dependency is now really obvious, but also,
we no longer care in which order gdbpy_initialize_record and
gdbpy_initialize_instruction are called.
There should be no user visible changes after this commit.
---
gdb/python/py-instruction.c | 41 +++++++++++++++++++++++++++++--------
gdb/python/py-instruction.h | 13 ++++++++----
gdb/python/py-record.c | 2 +-
3 files changed, 42 insertions(+), 14 deletions(-)
diff --git a/gdb/python/py-instruction.c b/gdb/python/py-instruction.c
index e1ad49a5143..fee5bba4015 100644
--- a/gdb/python/py-instruction.c
+++ b/gdb/python/py-instruction.c
@@ -20,7 +20,9 @@
#include "defs.h"
#include "py-instruction.h"
-/* See py-instruction.h. */
+/* Python type object for the abstract gdb.Instruction class. This class
+ contains getters for four elements: "pc" (int), "data" (buffer), "decode"
+ (str) and "size" (int) that must be overridden by sub classes. */
PyTypeObject py_insn_type = {
PyVarObject_HEAD_INIT (NULL, 0)
@@ -51,17 +53,38 @@ static gdb_PyGetSetDef py_insn_getset[] =
{NULL}
};
+/* See py-instruction.h. */
+
+PyTypeObject *
+py_insn_get_insn_type ()
+{
+ if (py_insn_type.tp_new == nullptr)
+ {
+ py_insn_type.tp_new = PyType_GenericNew;
+ py_insn_type.tp_flags = Py_TPFLAGS_DEFAULT;
+ py_insn_type.tp_basicsize = sizeof (py_insn_obj);
+ py_insn_type.tp_name = "gdb.Instruction";
+ py_insn_type.tp_doc = "GDB instruction object";
+ py_insn_type.tp_getset = py_insn_getset;
+
+ if (PyType_Ready (&py_insn_type) < 0)
+ {
+ /* Reset the tp_new field so any subsequent calls to this
+ function will retry to make the type ready. */
+ py_insn_type.tp_new = nullptr;
+ return nullptr;
+ }
+ }
+
+ return &py_insn_type;
+}
+
/* Sets up the gdb.Instruction type. */
int
gdbpy_initialize_instruction (void)
{
- py_insn_type.tp_new = PyType_GenericNew;
- py_insn_type.tp_flags = Py_TPFLAGS_DEFAULT;
- py_insn_type.tp_basicsize = sizeof (py_insn_obj);
- py_insn_type.tp_name = "gdb.Instruction";
- py_insn_type.tp_doc = "GDB instruction object";
- py_insn_type.tp_getset = py_insn_getset;
-
- return PyType_Ready (&py_insn_type);
+ if (py_insn_get_insn_type () == nullptr)
+ return -1;
+ return 0;
}
diff --git a/gdb/python/py-instruction.h b/gdb/python/py-instruction.h
index 59f0893e641..1e602636a39 100644
--- a/gdb/python/py-instruction.h
+++ b/gdb/python/py-instruction.h
@@ -22,9 +22,14 @@
#include "python-internal.h"
-/* Python type object for the abstract gdb.Instruction class. This class
- contains getters for four elements: "pc" (int), "data" (buffer), "decode"
- (str) and "size" (int) that must be overridden by sub classes. */
-extern PyTypeObject py_insn_type;
+/* Return a pointer to the py_insn_type object (see py-instruction.c), but
+ ensure that PyType_Ready has been called for the type first. If the
+ PyType_Ready call is successful then subsequent calls to this function
+ will not call PyType_Ready, the type pointer will just be returned.
+
+ If the PyType_Ready call is not successful then nullptr is returned and
+ subsequent calls to this function will call PyType_Ready again. */
+
+extern PyTypeObject *py_insn_get_insn_type ();
#endif /* PYTHON_PY_INSTRUCTION_H */
diff --git a/gdb/python/py-record.c b/gdb/python/py-record.c
index 51084dfac72..fd5cfee84eb 100644
--- a/gdb/python/py-record.c
+++ b/gdb/python/py-record.c
@@ -563,7 +563,7 @@ gdbpy_initialize_record (void)
recpy_insn_type.tp_getset = recpy_insn_getset;
recpy_insn_type.tp_richcompare = recpy_element_richcompare;
recpy_insn_type.tp_hash = recpy_element_hash;
- recpy_insn_type.tp_base = &py_insn_type;
+ recpy_insn_type.tp_base = py_insn_get_insn_type ();
recpy_func_type.tp_new = PyType_GenericNew;
recpy_func_type.tp_flags = Py_TPFLAGS_DEFAULT;
--
2.25.4
next prev parent reply other threads:[~2022-10-02 16:53 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-02 16:53 [PATCH 0/3] New mechanism to initialise Python components in GDB Andrew Burgess
2022-10-02 16:53 ` Andrew Burgess [this message]
2022-10-14 17:06 ` [PATCH 1/3] gdb/python: break dependencies between gdbpy_initialize_* functions Tom Tromey
2022-10-20 15:58 ` Andrew Burgess
2022-10-02 16:53 ` [PATCH 2/3] gdb/python: break more " Andrew Burgess
2022-10-14 17:06 ` Tom Tromey
2022-10-20 15:59 ` Andrew Burgess
2022-10-02 16:53 ` [PATCH 3/3] gdb/python: add gdbpy_register_subsystem mechanism Andrew Burgess
2022-10-14 17:20 ` Tom Tromey
2022-10-21 13:17 ` [PATCHv2] gdb/python: add mechanism to manage Python initialization functions Andrew Burgess
2023-04-17 15:26 ` Tom Tromey
2023-05-05 17:27 ` Andrew Burgess
2023-05-05 20:07 ` Tom Tromey
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