gdb/python/py-tui.c

   1 /* TUI windows implemented in Python
   2
   3    Copyright (C) 2020-2021 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20
  21 #include "defs.h"
  22 #include "arch-utils.h"
  23 #include "python-internal.h"
  24
  25 #ifdef TUI
  26
  27 /* Note that Python's public headers may define HAVE_NCURSES_H, so if
  28    we unconditionally include this (outside the #ifdef above), then we
  29    can get a compile error when ncurses is not in fact installed.  See
  30    PR tui/25597; or the upstream Python bug
  31    https://bugs.python.org/issue20768.  */
  32 #include "gdb_curses.h"
  33
  34 #include "tui/tui-data.h"
  35 #include "tui/tui-io.h"
  36 #include "tui/tui-layout.h"
  37 #include "tui/tui-wingeneral.h"
  38 #include "tui/tui-winsource.h"
  39
  40 class tui_py_window;
  41
  42 /* A PyObject representing a TUI window.  */
  43
  44 struct gdbpy_tui_window
  45 {
  46   PyObject_HEAD
  47
  48   /* The TUI window, or nullptr if the window has been deleted.  */
  49   tui_py_window *window;
  50
  51   /* Return true if this object is valid.  */
  52   bool is_valid () const;
  53 };
  54
  55 extern PyTypeObject gdbpy_tui_window_object_type
  56     CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("gdbpy_tui_window");
  57
  58 /* A TUI window written in Python.  */
  59
  60 class tui_py_window : public tui_win_info
  61 {
  62 public:
  63
  64   tui_py_window (const char *name, gdbpy_ref<gdbpy_tui_window> wrapper)
  65     : m_name (name),
  66       m_wrapper (std::move (wrapper))
  67   {
  68     m_wrapper->window = this;
  69   }
  70
  71   ~tui_py_window ();
  72
  73   DISABLE_COPY_AND_ASSIGN (tui_py_window);
  74
  75   /* Set the "user window" to the indicated reference.  The user
  76      window is the object returned the by user-defined window
  77      constructor.  */
  78   void set_user_window (gdbpy_ref<> &&user_window)
  79   {
  80     m_window = std::move (user_window);
  81   }
  82
  83   const char *name () const override
  84   {
  85     return m_name.c_str ();
  86   }
  87
  88   void rerender () override;
  89   void do_scroll_vertical (int num_to_scroll) override;
  90   void do_scroll_horizontal (int num_to_scroll) override;
  91
  92   void refresh_window () override
  93   {
  94     tui_win_info::refresh_window ();
  95     if (m_inner_window != nullptr)
  96       {
  97         touchwin (m_inner_window.get ());
  98         tui_wrefresh (m_inner_window.get ());
  99       }
 100   }
 101
 102   /* Erase and re-box the window.  */
 103   void erase ()
 104   {
 105     if (is_visible () && m_inner_window != nullptr)
 106       {
 107         werase (m_inner_window.get ());
 108         check_and_display_highlight_if_needed ();
 109       }
 110   }
 111
 112   /* Write STR to the window.  */
 113   void output (const char *str);
 114
 115   /* A helper function to compute the viewport width.  */
 116   int viewport_width () const
 117   {
 118     return std::max (0, width - 2);
 119   }
 120
 121   /* A helper function to compute the viewport height.  */
 122   int viewport_height () const
 123   {
 124     return std::max (0, height - 2);
 125   }
 126
 127 private:
 128
 129   /* The name of this window.  */
 130   std::string m_name;
 131
 132   /* We make our own inner window, so that it is easy to print without
 133      overwriting the border.  */
 134   std::unique_ptr<WINDOW, curses_deleter> m_inner_window;
 135
 136   /* The underlying Python window object.  */
 137   gdbpy_ref<> m_window;
 138
 139   /* The Python wrapper for this object.  */
 140   gdbpy_ref<gdbpy_tui_window> m_wrapper;
 141 };
 142
 143 /* See gdbpy_tui_window declaration above.  */
 144
 145 bool
 146 gdbpy_tui_window::is_valid () const
 147 {
 148   return window != nullptr && tui_active;
 149 }
 150
 151 tui_py_window::~tui_py_window ()
 152 {
 153   gdbpy_enter enter_py (get_current_arch (), current_language);
 154
 155   /* This can be null if the user-provided Python construction
 156      function failed.  */
 157   if (m_window != nullptr
 158       && PyObject_HasAttrString (m_window.get (), "close"))
 159     {
 160       gdbpy_ref<> result (PyObject_CallMethod (m_window.get (), "close",
 161                                                nullptr));
 162       if (result == nullptr)
 163         gdbpy_print_stack ();
 164     }
 165
 166   /* Unlink.  */
 167   m_wrapper->window = nullptr;
 168   /* Explicitly free the Python references.  We have to do this
 169      manually because we need to hold the GIL while doing so.  */
 170   m_wrapper.reset (nullptr);
 171   m_window.reset (nullptr);
 172 }
 173
 174 void
 175 tui_py_window::rerender ()
 176 {
 177   tui_win_info::rerender ();
 178
 179   gdbpy_enter enter_py (get_current_arch (), current_language);
 180
 181   int h = viewport_height ();
 182   int w = viewport_width ();
 183   if (h == 0 || w == 0)
 184     {
 185       /* The window would be too small, so just remove the
 186          contents.  */
 187       m_inner_window.reset (nullptr);
 188       return;
 189     }
 190   m_inner_window.reset (newwin (h, w, y + 1, x + 1));
 191
 192   if (PyObject_HasAttrString (m_window.get (), "render"))
 193     {
 194       gdbpy_ref<> result (PyObject_CallMethod (m_window.get (), "render",
 195                                                nullptr));
 196       if (result == nullptr)
 197         gdbpy_print_stack ();
 198     }
 199 }
 200
 201 void
 202 tui_py_window::do_scroll_horizontal (int num_to_scroll)
 203 {
 204   gdbpy_enter enter_py (get_current_arch (), current_language);
 205
 206   if (PyObject_HasAttrString (m_window.get (), "hscroll"))
 207     {
 208       gdbpy_ref<> result (PyObject_CallMethod (m_window.get(), "hscroll",
 209                                                "i", num_to_scroll, nullptr));
 210       if (result == nullptr)
 211         gdbpy_print_stack ();
 212     }
 213 }
 214
 215 void
 216 tui_py_window::do_scroll_vertical (int num_to_scroll)
 217 {
 218   gdbpy_enter enter_py (get_current_arch (), current_language);
 219
 220   if (PyObject_HasAttrString (m_window.get (), "vscroll"))
 221     {
 222       gdbpy_ref<> result (PyObject_CallMethod (m_window.get (), "vscroll",
 223                                                "i", num_to_scroll, nullptr));
 224       if (result == nullptr)
 225         gdbpy_print_stack ();
 226     }
 227 }
 228
 229 void
 230 tui_py_window::output (const char *text)
 231 {
 232   if (m_inner_window != nullptr)
 233     {
 234       tui_puts (text, m_inner_window.get ());
 235       tui_wrefresh (m_inner_window.get ());
 236     }
 237 }
 238
 239 \f
 240
 241 /* A callable that is used to create a TUI window.  It wraps the
 242    user-supplied window constructor.  */
 243
 244 class gdbpy_tui_window_maker
 245 {
 246 public:
 247
 248   explicit gdbpy_tui_window_maker (gdbpy_ref<> &&constr)
 249     : m_constr (std::move (constr))
 250   {
 251   }
 252
 253   ~gdbpy_tui_window_maker ();
 254
 255   gdbpy_tui_window_maker (gdbpy_tui_window_maker &&other) noexcept
 256     : m_constr (std::move (other.m_constr))
 257   {
 258   }
 259
 260   gdbpy_tui_window_maker (const gdbpy_tui_window_maker &other)
 261   {
 262     gdbpy_enter enter_py (get_current_arch (), current_language);
 263     m_constr = other.m_constr;
 264   }
 265
 266   gdbpy_tui_window_maker &operator= (gdbpy_tui_window_maker &&other)
 267   {
 268     m_constr = std::move (other.m_constr);
 269     return *this;
 270   }
 271
 272   gdbpy_tui_window_maker &operator= (const gdbpy_tui_window_maker &other)
 273   {
 274     gdbpy_enter enter_py (get_current_arch (), current_language);
 275     m_constr = other.m_constr;
 276     return *this;
 277   }
 278
 279   tui_win_info *operator() (const char *name);
 280
 281 private:
 282
 283   /* A constructor that is called to make a TUI window.  */
 284   gdbpy_ref<> m_constr;
 285 };
 286
 287 gdbpy_tui_window_maker::~gdbpy_tui_window_maker ()
 288 {
 289   gdbpy_enter enter_py (get_current_arch (), current_language);
 290   m_constr.reset (nullptr);
 291 }
 292
 293 tui_win_info *
 294 gdbpy_tui_window_maker::operator() (const char *win_name)
 295 {
 296   gdbpy_enter enter_py (get_current_arch (), current_language);
 297
 298   gdbpy_ref<gdbpy_tui_window> wrapper
 299     (PyObject_New (gdbpy_tui_window, &gdbpy_tui_window_object_type));
 300   if (wrapper == nullptr)
 301     {
 302       gdbpy_print_stack ();
 303       return nullptr;
 304     }
 305
 306   std::unique_ptr<tui_py_window> window
 307     (new tui_py_window (win_name, wrapper));
 308
 309   gdbpy_ref<> user_window
 310     (PyObject_CallFunctionObjArgs (m_constr.get (),
 311                                    (PyObject *) wrapper.get (),
 312                                    nullptr));
 313   if (user_window == nullptr)
 314     {
 315       gdbpy_print_stack ();
 316       return nullptr;
 317     }
 318
 319   window->set_user_window (std::move (user_window));
 320   /* Window is now owned by the TUI.  */
 321   return window.release ();
 322 }
 323
 324 /* Implement "gdb.register_window_type".  */
 325
 326 PyObject *
 327 gdbpy_register_tui_window (PyObject *self, PyObject *args, PyObject *kw)
 328 {
 329   static const char *keywords[] = { "name", "constructor", nullptr };
 330
 331   const char *name;
 332   PyObject *cons_obj;
 333
 334   if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "sO", keywords,
 335                                         &name, &cons_obj))
 336     return nullptr;
 337
 338   try
 339     {
 340       gdbpy_tui_window_maker constr (gdbpy_ref<>::new_reference (cons_obj));
 341       tui_register_window (name, constr);
 342     }
 343   catch (const gdb_exception &except)
 344     {
 345       gdbpy_convert_exception (except);
 346       return nullptr;
 347     }
 348
 349   Py_RETURN_NONE;
 350 }
 351
 352 \f
 353
 354 /* Require that "Window" be a valid window.  */
 355
 356 #define REQUIRE_WINDOW(Window)                                  \
 357     do {                                                        \
 358       if (!(Window)->is_valid ())                               \
 359         return PyErr_Format (PyExc_RuntimeError,                \
 360                              _("TUI window is invalid."));      \
 361     } while (0)
 362
 363 /* Require that "Window" be a valid window.  */
 364
 365 #define REQUIRE_WINDOW_FOR_SETTER(Window)                       \
 366     do {                                                        \
 367       if (!(Window)->is_valid ())                               \
 368         {                                                       \
 369           PyErr_Format (PyExc_RuntimeError,                     \
 370                         _("TUI window is invalid."));           \
 371           return -1;                                            \
 372         }                                                       \
 373     } while (0)
 374
 375 /* Python function which checks the validity of a TUI window
 376    object.  */
 377 static PyObject *
 378 gdbpy_tui_is_valid (PyObject *self, PyObject *args)
 379 {
 380   gdbpy_tui_window *win = (gdbpy_tui_window *) self;
 381
 382   if (win->is_valid ())
 383     Py_RETURN_TRUE;
 384   Py_RETURN_FALSE;
 385 }
 386
 387 /* Python function that erases the TUI window.  */
 388 static PyObject *
 389 gdbpy_tui_erase (PyObject *self, PyObject *args)
 390 {
 391   gdbpy_tui_window *win = (gdbpy_tui_window *) self;
 392
 393   REQUIRE_WINDOW (win);
 394
 395   win->window->erase ();
 396
 397   Py_RETURN_NONE;
 398 }
 399
 400 /* Python function that writes some text to a TUI window.  */
 401 static PyObject *
 402 gdbpy_tui_write (PyObject *self, PyObject *args)
 403 {
 404   gdbpy_tui_window *win = (gdbpy_tui_window *) self;
 405   const char *text;
 406
 407   if (!PyArg_ParseTuple (args, "s", &text))
 408     return nullptr;
 409
 410   REQUIRE_WINDOW (win);
 411
 412   win->window->output (text);
 413
 414   Py_RETURN_NONE;
 415 }
 416
 417 /* Return the width of the TUI window.  */
 418 static PyObject *
 419 gdbpy_tui_width (PyObject *self, void *closure)
 420 {
 421   gdbpy_tui_window *win = (gdbpy_tui_window *) self;
 422   REQUIRE_WINDOW (win);
 423   gdbpy_ref<> result
 424     = gdb_py_object_from_longest (win->window->viewport_width ());
 425   return result.release ();
 426 }
 427
 428 /* Return the height of the TUI window.  */
 429 static PyObject *
 430 gdbpy_tui_height (PyObject *self, void *closure)
 431 {
 432   gdbpy_tui_window *win = (gdbpy_tui_window *) self;
 433   REQUIRE_WINDOW (win);
 434   gdbpy_ref<> result
 435     = gdb_py_object_from_longest (win->window->viewport_height ());
 436   return result.release ();
 437 }
 438
 439 /* Return the title of the TUI window.  */
 440 static PyObject *
 441 gdbpy_tui_title (PyObject *self, void *closure)
 442 {
 443   gdbpy_tui_window *win = (gdbpy_tui_window *) self;
 444   REQUIRE_WINDOW (win);
 445   return host_string_to_python_string (win->window->title.c_str ()).release ();
 446 }
 447
 448 /* Set the title of the TUI window.  */
 449 static int
 450 gdbpy_tui_set_title (PyObject *self, PyObject *newvalue, void *closure)
 451 {
 452   gdbpy_tui_window *win = (gdbpy_tui_window *) self;
 453
 454   REQUIRE_WINDOW_FOR_SETTER (win);
 455
 456   if (newvalue == nullptr)
 457     {
 458       PyErr_Format (PyExc_TypeError, _("Cannot delete \"title\" attribute."));
 459       return -1;
 460     }
 461
 462   gdb::unique_xmalloc_ptr<char> value
 463     = python_string_to_host_string (newvalue);
 464   if (value == nullptr)
 465     return -1;
 466
 467   win->window->title = value.get ();
 468   return 0;
 469 }
 470
 471 static gdb_PyGetSetDef tui_object_getset[] =
 472 {
 473   { "width", gdbpy_tui_width, NULL, "Width of the window.", NULL },
 474   { "height", gdbpy_tui_height, NULL, "Height of the window.", NULL },
 475   { "title", gdbpy_tui_title, gdbpy_tui_set_title, "Title of the window.",
 476     NULL },
 477   { NULL }  /* Sentinel */
 478 };
 479
 480 static PyMethodDef tui_object_methods[] =
 481 {
 482   { "is_valid", gdbpy_tui_is_valid, METH_NOARGS,
 483     "is_valid () -> Boolean\n\
 484 Return true if this TUI window is valid, false if not." },
 485   { "erase", gdbpy_tui_erase, METH_NOARGS,
 486     "Erase the TUI window." },
 487   { "write", (PyCFunction) gdbpy_tui_write, METH_VARARGS,
 488     "Append a string to the TUI window." },
 489   { NULL } /* Sentinel.  */
 490 };
 491
 492 PyTypeObject gdbpy_tui_window_object_type =
 493 {
 494   PyVarObject_HEAD_INIT (NULL, 0)
 495   "gdb.TuiWindow",                /*tp_name*/
 496   sizeof (gdbpy_tui_window),      /*tp_basicsize*/
 497   0,                              /*tp_itemsize*/
 498   0,                              /*tp_dealloc*/
 499   0,                              /*tp_print*/
 500   0,                              /*tp_getattr*/
 501   0,                              /*tp_setattr*/
 502   0,                              /*tp_compare*/
 503   0,                              /*tp_repr*/
 504   0,                              /*tp_as_number*/
 505   0,                              /*tp_as_sequence*/
 506   0,                              /*tp_as_mapping*/
 507   0,                              /*tp_hash */
 508   0,                              /*tp_call*/
 509   0,                              /*tp_str*/
 510   0,                              /*tp_getattro*/
 511   0,                              /*tp_setattro */
 512   0,                              /*tp_as_buffer*/
 513   Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,  /*tp_flags*/
 514   "GDB TUI window object",        /* tp_doc */
 515   0,                              /* tp_traverse */
 516   0,                              /* tp_clear */
 517   0,                              /* tp_richcompare */
 518   0,                              /* tp_weaklistoffset */
 519   0,                              /* tp_iter */
 520   0,                              /* tp_iternext */
 521   tui_object_methods,             /* tp_methods */
 522   0,                              /* tp_members */
 523   tui_object_getset,              /* tp_getset */
 524   0,                              /* tp_base */
 525   0,                              /* tp_dict */
 526   0,                              /* tp_descr_get */
 527   0,                              /* tp_descr_set */
 528   0,                              /* tp_dictoffset */
 529   0,                              /* tp_init */
 530   0,                              /* tp_alloc */
 531 };
 532
 533 #endif /* TUI */
 534
 535 /* Initialize this module.  */
 536
 537 int
 538 gdbpy_initialize_tui ()
 539 {
 540 #ifdef TUI
 541   gdbpy_tui_window_object_type.tp_new = PyType_GenericNew;
 542   if (PyType_Ready (&gdbpy_tui_window_object_type) < 0)
 543     return -1;
 544 #endif  /* TUI */
 545
 546   return 0;
 547 }