[binutils-gdb] Convert py-tui.c to the "python safety" approach

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=c7c7858871f77bb265bbce492d39716f39e0d462

commit c7c7858871f77bb265bbce492d39716f39e0d462
Author: Tom Tromey <[email protected]>
Date:   Fri May 15 11:42:08 2026 -0600

    Convert py-tui.c to the "python safety" approach
    
    This patch mostly converts py-tui.c to use the new Python safety code.
    
    In particular:
    
    * All methods of gdb.TuiWindow are now implemented as straightforward
      methods of gdbpy_tui_window.
    
    * gdbpy_register_tui_window is converted and simply returns 'void'.
    
    I converted this particular file because it was relatively
    straightforward, while also demonstrating most of the features of the
    new approach.  For example, explicit result checks aren't needed,
    try/catch can be removed, and the methods are now written in a natural
    style.
    
    Note that more conversion remains to be done here:
    
    * gdbpy_tui_enabled hasn't been converted and still does explicit
      checks.
    
    * There's one explicit check in gdbpy_tui_window::set_title.  Fully
      implementing the safety approach means that some low-level things
      should eventually be converted to throw; but some work has to be
      deferred until a lot of the work is complete.
    
    Acked-By: Tom de Vries <[email protected]>

Diff:
---
 gdb/python/py-tui.c          | 209 ++++++++++++++++++-------------------------
 gdb/python/python-internal.h |   5 +-
 gdb/python/python.c          |   5 +-
 3 files changed, 94 insertions(+), 125 deletions(-)

diff --git a/gdb/python/py-tui.c b/gdb/python/py-tui.c
index ca0fb89ea49..5a36814debb 100644
--- a/gdb/python/py-tui.c
+++ b/gdb/python/py-tui.c
@@ -44,13 +44,40 @@ class tui_py_window;
 
 /* A PyObject representing a TUI window.  */
 
-struct gdbpy_tui_window: public PyObject
+struct gdbpy_tui_window : public PyObject
 {
   /* The TUI window, or nullptr if the window has been deleted.  */
   tui_py_window *window;
 
   /* Return true if this object is valid.  */
   bool is_valid () const;
+
+  /* Require that this object be valid.  Throws exception if not.  */
+  void require_valid () const
+  {
+    if (!is_valid ())
+      gdbpy_err_format (PyExc_RuntimeError, _("TUI window is invalid."));
+  }
+
+  /* Erase the TUI window.  */
+  void erase ();
+
+  /* Python function that writes some text to a TUI window.  */
+  void write (gdbpy_borrowed_ref<> args, gdbpy_opt_borrowed_ref<> kw);
+
+  /* Return the width of the TUI window.  */
+  int width () const;
+
+  /* Return the height of the TUI window.  */
+  int height () const;
+
+  /* Return the title of the TUI window.  */
+  const std::string &title () const;
+
+  /* Set the title of the TUI window.  */
+  void set_title (gdbpy_opt_borrowed_ref<> new_title);
+
+  static PyTypeObject *corresponding_object_type;
 };
 
 static_assert (gdb::is_python_allocatable_v<gdbpy_tui_window>);
@@ -408,173 +435,112 @@ gdbpy_tui_window_maker::operator() (const char *win_name)
 
 /* Implement "gdb.register_window_type".  */
 
-PyObject *
-gdbpy_register_tui_window (PyObject *self, PyObject *args, PyObject *kw)
+void
+gdbpy_register_tui_window (gdbpy_borrowed_ref<> args,
+			   gdbpy_opt_borrowed_ref<> kw)
 {
   static const char *keywords[] = { "name", "constructor", nullptr };
-
   const char *name;
   PyObject *cons_obj;
+  gdbpy_arg_parse_tuple_and_keywords (args, kw, "sO", keywords,
+				      &name, &cons_obj);
 
-  if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "sO", keywords,
-					&name, &cons_obj))
-    return nullptr;
-
-  try
-    {
-      gdbpy_tui_window_maker constr (gdbpy_ref<>::new_reference (cons_obj));
-      tui_register_window (name, constr);
-    }
-  catch (const gdb_exception &except)
-    {
-      return gdbpy_handle_gdb_exception (nullptr, except);
-    }
-
-  return py_none ().release ();
+  gdbpy_tui_window_maker constr (gdbpy_ref<>::new_reference (cons_obj));
+  tui_register_window (name, constr);
 }
 
 
 
-/* Require that "Window" be a valid window.  */
-
-#define REQUIRE_WINDOW(Window)					\
-    do {							\
-      if (!(Window)->is_valid ())				\
-	return PyErr_Format (PyExc_RuntimeError,		\
-			     _("TUI window is invalid."));	\
-    } while (0)
-
-/* Require that "Window" be a valid window.  */
-
-#define REQUIRE_WINDOW_FOR_SETTER(Window)			\
-    do {							\
-      if (!(Window)->is_valid ())				\
-	{							\
-	  PyErr_Format (PyExc_RuntimeError,			\
-			_("TUI window is invalid."));		\
-	  return -1;						\
-	}							\
-    } while (0)
-
-/* Python function which checks the validity of a TUI window
-   object.  */
-static PyObject *
-gdbpy_tui_is_valid (PyObject *self, PyObject *args)
-{
-  gdbpy_tui_window *win = (gdbpy_tui_window *) self;
-
-  if (win->is_valid ())
-    return py_true ().release ();
-  return py_false ().release ();
-}
-
 /* Python function that erases the TUI window.  */
-static PyObject *
-gdbpy_tui_erase (PyObject *self, PyObject *args)
+void
+gdbpy_tui_window::erase ()
 {
-  gdbpy_tui_window *win = (gdbpy_tui_window *) self;
-
-  REQUIRE_WINDOW (win);
-
-  win->window->erase ();
-
-  return py_none ().release ();
+  require_valid ();
+  window->erase ();
 }
 
 /* Python function that writes some text to a TUI window.  */
-static PyObject *
-gdbpy_tui_write (PyObject *self, PyObject *args, PyObject *kw)
+void
+gdbpy_tui_window::write (gdbpy_borrowed_ref<> args,
+			 gdbpy_opt_borrowed_ref<> kw)
 {
+  require_valid ();
+
   static const char *keywords[] = { "string", "full_window", nullptr };
 
-  gdbpy_tui_window *win = (gdbpy_tui_window *) self;
   const char *text;
   int full_window = 0;
 
-  if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "s|i", keywords,
-					&text, &full_window))
-    return nullptr;
-
-  REQUIRE_WINDOW (win);
+  gdbpy_arg_parse_tuple_and_keywords (args, kw, "s|i", keywords,
+				      &text, &full_window);
 
-  win->window->output (text, full_window);
-
-  return py_none ().release ();
+  window->output (text, full_window);
 }
 
-/* Return the width of the TUI window.  */
-static PyObject *
-gdbpy_tui_width (PyObject *self, void *closure)
+int
+gdbpy_tui_window::width () const
 {
-  gdbpy_tui_window *win = (gdbpy_tui_window *) self;
-  REQUIRE_WINDOW (win);
-  gdbpy_ref<> result
-    = gdb_py_object_from_longest (win->window->viewport_width ());
-  return result.release ();
+  require_valid ();
+  return window->viewport_width ();
 }
 
-/* Return the height of the TUI window.  */
-static PyObject *
-gdbpy_tui_height (PyObject *self, void *closure)
+int
+gdbpy_tui_window::height () const
 {
-  gdbpy_tui_window *win = (gdbpy_tui_window *) self;
-  REQUIRE_WINDOW (win);
-  gdbpy_ref<> result
-    = gdb_py_object_from_longest (win->window->viewport_height ());
-  return result.release ();
+  require_valid ();
+  return window->viewport_height ();
 }
 
-/* Return the title of the TUI window.  */
-static PyObject *
-gdbpy_tui_title (PyObject *self, void *closure)
+const std::string &
+gdbpy_tui_window::title () const
 {
-  gdbpy_tui_window *win = (gdbpy_tui_window *) self;
-  REQUIRE_WINDOW (win);
-  return host_string_to_python_string (win->window->title ().c_str ()).release ();
+  require_valid ();
+  return window->title ();
 }
 
 /* Set the title of the TUI window.  */
-static int
-gdbpy_tui_set_title (PyObject *self, PyObject *newvalue, void *closure)
+void
+gdbpy_tui_window::set_title (gdbpy_opt_borrowed_ref<> new_title)
 {
-  gdbpy_tui_window *win = (gdbpy_tui_window *) self;
+  require_valid ();
 
-  REQUIRE_WINDOW_FOR_SETTER (win);
-
-  if (newvalue == nullptr)
-    {
-      PyErr_Format (PyExc_TypeError, _("Cannot delete \"title\" attribute."));
-      return -1;
-    }
+  if (new_title == nullptr)
+    gdbpy_err_format (PyExc_TypeError,
+		      _("Cannot delete \"title\" attribute."));
 
+  /* FIXME: Python safety.  Ideally python_string_to_host_string would
+     throw on error, but this can't be done until more of the code has
+     been converted.  */
   gdb::unique_xmalloc_ptr<char> value
-    = python_string_to_host_string (newvalue);
+    = python_string_to_host_string (new_title);
   if (value == nullptr)
-    return -1;
+    throw gdb_python_exception ();
 
-  win->window->set_title (value.get ());
-  return 0;
+  window->set_title (value.get ());
 }
 
 static gdb_PyGetSetDef tui_object_getset[] =
 {
-  { "width", gdbpy_tui_width, NULL, "Width of the window.", NULL },
-  { "height", gdbpy_tui_height, NULL, "Height of the window.", NULL },
-  { "title", gdbpy_tui_title, gdbpy_tui_set_title, "Title of the window.",
-    NULL },
-  { NULL }  /* Sentinel */
+  { "width", wrap_getter<gdbpy_tui_window, &gdbpy_tui_window::width>, nullptr,
+    "Width of the window.", nullptr },
+  { "height", wrap_getter<gdbpy_tui_window, &gdbpy_tui_window::height>, nullptr,
+    "Height of the window.", nullptr },
+  { "title", wrap_getter<gdbpy_tui_window, &gdbpy_tui_window::title>,
+    wrap_setter<gdbpy_tui_window, &gdbpy_tui_window::set_title>,
+    "Title of the window.", nullptr },
+  { nullptr }  /* Sentinel */
 };
 
 static PyMethodDef tui_object_methods[] =
 {
-  { "is_valid", gdbpy_tui_is_valid, METH_NOARGS,
+  noargs_method<gdbpy_tui_window, &gdbpy_tui_window::is_valid> ("is_valid",
     "is_valid () -> Boolean\n\
-Return true if this TUI window is valid, false if not." },
-  { "erase", gdbpy_tui_erase, METH_NOARGS,
-    "Erase the TUI window." },
-  { "write", (PyCFunction) gdbpy_tui_write, METH_VARARGS | METH_KEYWORDS,
-    "Append a string to the TUI window." },
-  { NULL } /* Sentinel.  */
+Return true if this TUI window is valid, false if not."),
+  noargs_method<gdbpy_tui_window, &gdbpy_tui_window::erase>
+    ("erase", "Erase the TUI window."),
+  varargs_method<gdbpy_tui_window, &gdbpy_tui_window::write> ("write",
+    "Append a string to the TUI window."),
+  { nullptr } /* Sentinel.  */
 };
 
 PyTypeObject gdbpy_tui_window_object_type =
@@ -618,6 +584,9 @@ PyTypeObject gdbpy_tui_window_object_type =
   0,				  /* tp_alloc */
 };
 
+PyTypeObject *gdbpy_tui_window::corresponding_object_type
+    = &gdbpy_tui_window_object_type;
+
 /* Called when TUI is enabled or disabled.  */
 
 static void
diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h
index 0793c7fa2af..1165f165e29 100644
--- a/gdb/python/python-internal.h
+++ b/gdb/python/python-internal.h
@@ -498,8 +498,9 @@ gdb::unique_xmalloc_ptr<char> gdbpy_parse_command_name
   (const char *name, struct cmd_list_element ***base_list,
    struct cmd_list_element **start_list,
    struct cmd_list_element **prefix_cmd = nullptr);
-PyObject *gdbpy_register_tui_window (PyObject *self, PyObject *args,
-				     PyObject *kw);
+
+void gdbpy_register_tui_window (gdbpy_borrowed_ref<> args,
+				gdbpy_opt_borrowed_ref<> kw);
 
 gdbpy_ref<> symtab_and_line_to_sal_object (struct symtab_and_line sal);
 gdbpy_ref<> symtab_to_symtab_object (struct symtab *symtab);
diff --git a/gdb/python/python.c b/gdb/python/python.c
index 214abd03905..7b5de98b903 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -3274,10 +3274,9 @@ or None if not set." },
 Set the value of the convenience variable $NAME." },
 
 #ifdef TUI
-  { "register_window_type", (PyCFunction) gdbpy_register_tui_window,
-    METH_VARARGS | METH_KEYWORDS,
+  varargs_function<gdbpy_register_tui_window> ("register_window_type",
     "register_window_type (NAME, CONSTRUCTOR) -> None\n\
-Register a TUI window constructor." },
+Register a TUI window constructor."),
 #endif	/* TUI */
 
   { "architecture_names", gdbpy_all_architecture_names, METH_NOARGS,