gdb/python/py-tui.c

   1 /* TUI windows implemented in Python
   2
   3    Copyright (C) 2020 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
  52 extern PyTypeObject gdbpy_tui_window_object_type
  53     CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("gdbpy_tui_window");
  54
  55 /* A TUI window written in Python.  */
  56
  57 class tui_py_window : public tui_win_info
  58 {
  59 public:
  60
  61   tui_py_window (const char *name, gdbpy_ref<gdbpy_tui_window> wrapper)
  62     : m_name (name),
  63       m_wrapper (std::move (wrapper))
  64   {
  65     m_wrapper->window = this;
  66   }
  67
  68   ~tui_py_window ();
  69
  70   DISABLE_COPY_AND_ASSIGN (tui_py_window);
  71
  72   /* Set the "user window" to the indicated reference.  The user
  73      window is the object returned the by user-defined window
  74      constructor.  */
  75   void set_user_window (gdbpy_ref<> &&user_window)
  76   {
  77     m_window = std::move (user_window);
  78   }
  79
  80   const char *name () const override
  81   {
  82     return m_name.c_str ();
  83   }
  84
  85   void rerender () override;
  86   void do_scroll_vertical (int num_to_scroll) override;
  87   void do_scroll_horizontal (int num_to_scroll) override;
  88
  89   /* Erase and re-box the window.  */
  90   void erase ()
  91   {
  92     if (is_visible ())
  93       {
  94         werase (handle.get ());
  95         check_and_display_highlight_if_needed ();
  96         cursor_x = 0;
  97         cursor_y = 0;
  98       }
  99   }
 100
 101   /* Write STR to the window.  */
 102   void output (const char *str);
 103
 104   /* A helper function to compute the viewport width.  */
 105   int viewport_width () const
 106   {
 107     return std::max (0, width - 2);
 108   }
 109
 110   /* A helper function to compute the viewport height.  */
 111   int viewport_height () const
 112   {
 113     return std::max (0, height - 2);
 114   }
 115
 116 private:
 117
 118   /* Location of the cursor.  */
 119   int cursor_x = 0;
 120   int cursor_y = 0;
 121
 122   /* The name of this window.  */
 123   std::string m_name;
 124
 125   /* The underlying Python window object.  */
 126   gdbpy_ref<> m_window;
 127
 128   /* The Python wrapper for this object.  */
 129   gdbpy_ref<gdbpy_tui_window> m_wrapper;
 130 };
 131
 132 tui_py_window::~tui_py_window ()
 133 {
 134   gdbpy_enter enter_py (get_current_arch (), current_language);
 135
 136   if (PyObject_HasAttrString (m_window.get (), "close"))
 137     {
 138       gdbpy_ref<> result (PyObject_CallMethod (m_window.get (), "close",
 139                                                nullptr));
 140       if (result == nullptr)
 141         gdbpy_print_stack ();
 142     }
 143
 144   /* Unlink.  */
 145   m_wrapper->window = nullptr;
 146   /* Explicitly free the Python references.  We have to do this
 147      manually because we need to hold the GIL while doing so.  */
 148   m_wrapper.reset (nullptr);
 149   m_window.reset (nullptr);
 150 }
 151
 152 void
 153 tui_py_window::rerender ()
 154 {
 155   gdbpy_enter enter_py (get_current_arch (), current_language);
 156
 157   if (PyObject_HasAttrString (m_window.get (), "render"))
 158     {
 159       gdbpy_ref<> result (PyObject_CallMethod (m_window.get (), "render",
 160                                                nullptr));
 161       if (result == nullptr)
 162         gdbpy_print_stack ();
 163     }
 164 }
 165
 166 void
 167 tui_py_window::do_scroll_horizontal (int num_to_scroll)
 168 {
 169   gdbpy_enter enter_py (get_current_arch (), current_language);
 170
 171   if (PyObject_HasAttrString (m_window.get (), "hscroll"))
 172     {
 173       gdbpy_ref<> result (PyObject_CallMethod (m_window.get(), "hscroll",
 174                                                "i", num_to_scroll, nullptr));
 175       if (result == nullptr)
 176         gdbpy_print_stack ();
 177     }
 178 }
 179
 180 void
 181 tui_py_window::do_scroll_vertical (int num_to_scroll)
 182 {
 183   gdbpy_enter enter_py (get_current_arch (), current_language);
 184
 185   if (PyObject_HasAttrString (m_window.get (), "vscroll"))
 186     {
 187       gdbpy_ref<> result (PyObject_CallMethod (m_window.get (), "vscroll",
 188                                                "i", num_to_scroll, nullptr));
 189       if (result == nullptr)
 190         gdbpy_print_stack ();
 191     }
 192 }
 193
 194 void
 195 tui_py_window::output (const char *text)
 196 {
 197   int vwidth = viewport_width ();
 198
 199   while (cursor_y < viewport_height () && *text != '\0')
 200     {
 201       wmove (handle.get (), cursor_y + 1, cursor_x + 1);
 202
 203       std::string line = tui_copy_source_line (&text, 0, 0,
 204                                                vwidth - cursor_x, 0);
 205       tui_puts (line.c_str (), handle.get ());
 206
 207       if (*text == '\n')
 208         {
 209           ++text;
 210           ++cursor_y;
 211           cursor_x = 0;
 212         }
 213       else
 214         cursor_x = getcurx (handle.get ()) - 1;
 215     }
 216
 217   wrefresh (handle.get ());
 218 }
 219
 220 \f
 221
 222 /* A callable that is used to create a TUI window.  It wraps the
 223    user-supplied window constructor.  */
 224
 225 class gdbpy_tui_window_maker
 226 {
 227 public:
 228
 229   explicit gdbpy_tui_window_maker (gdbpy_ref<> &&constr)
 230     : m_constr (std::move (constr))
 231   {
 232   }
 233
 234   ~gdbpy_tui_window_maker ();
 235
 236   gdbpy_tui_window_maker (gdbpy_tui_window_maker &&other)
 237     : m_constr (std::move (other.m_constr))
 238   {
 239   }
 240
 241   gdbpy_tui_window_maker (const gdbpy_tui_window_maker &other)
 242   {
 243     gdbpy_enter enter_py (get_current_arch (), current_language);
 244     m_constr = other.m_constr;
 245   }
 246
 247   gdbpy_tui_window_maker &operator= (gdbpy_tui_window_maker &&other)
 248   {
 249     m_constr = std::move (other.m_constr);
 250     return *this;
 251   }
 252
 253   gdbpy_tui_window_maker &operator= (const gdbpy_tui_window_maker &other)
 254   {
 255     gdbpy_enter enter_py (get_current_arch (), current_language);
 256     m_constr = other.m_constr;
 257     return *this;
 258   }
 259
 260   tui_win_info *operator() (const char *name);
 261
 262 private:
 263
 264   /* A constructor that is called to make a TUI window.  */
 265   gdbpy_ref<> m_constr;
 266 };
 267
 268 gdbpy_tui_window_maker::~gdbpy_tui_window_maker ()
 269 {
 270   gdbpy_enter enter_py (get_current_arch (), current_language);
 271   m_constr.reset (nullptr);
 272 }
 273
 274 tui_win_info *
 275 gdbpy_tui_window_maker::operator() (const char *win_name)
 276 {
 277   gdbpy_enter enter_py (get_current_arch (), current_language);
 278
 279   gdbpy_ref<gdbpy_tui_window> wrapper
 280     (PyObject_New (gdbpy_tui_window, &gdbpy_tui_window_object_type));
 281   if (wrapper == nullptr)
 282     {
 283       gdbpy_print_stack ();
 284       return nullptr;
 285     }
 286
 287   std::unique_ptr<tui_py_window> window
 288     (new tui_py_window (win_name, wrapper));
 289
 290   gdbpy_ref<> user_window
 291     (PyObject_CallFunctionObjArgs (m_constr.get (),
 292                                    (PyObject *) wrapper.get (),
 293                                    nullptr));
 294   if (user_window == nullptr)
 295     {
 296       gdbpy_print_stack ();
 297       return nullptr;
 298     }
 299
 300   window->set_user_window (std::move (user_window));
 301   /* Window is now owned by the TUI.  */
 302   return window.release ();
 303 }
 304
 305 /* Implement "gdb.register_window_type".  */
 306
 307 PyObject *
 308 gdbpy_register_tui_window (PyObject *self, PyObject *args, PyObject *kw)
 309 {
 310   static const char *keywords[] = { "name", "constructor", nullptr };
 311
 312   const char *name;
 313   PyObject *cons_obj;
 314
 315   if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "sO", keywords,
 316                                         &name, &cons_obj))
 317     return nullptr;
 318
 319   try
 320     {
 321       gdbpy_tui_window_maker constr (gdbpy_ref<>::new_reference (cons_obj));
 322       tui_register_window (name, constr);
 323     }
 324   catch (const gdb_exception &except)
 325     {
 326       gdbpy_convert_exception (except);
 327       return nullptr;
 328     }
 329
 330   Py_RETURN_NONE;
 331 }
 332
 333 \f
 334
 335 /* Require that "Window" be a valid window.  */
 336
 337 #define REQUIRE_WINDOW(Window)                                  \
 338     do {                                                        \
 339       if ((Window)->window == nullptr)                          \
 340         return PyErr_Format (PyExc_RuntimeError,                \
 341                              _("TUI window is invalid."));      \
 342     } while (0)
 343
 344 /* Python function which checks the validity of a TUI window
 345    object.  */
 346 static PyObject *
 347 gdbpy_tui_is_valid (PyObject *self, PyObject *args)
 348 {
 349   gdbpy_tui_window *win = (gdbpy_tui_window *) self;
 350
 351   if (win->window != nullptr)
 352     Py_RETURN_TRUE;
 353   Py_RETURN_FALSE;
 354 }
 355
 356 /* Python function that erases the TUI window.  */
 357 static PyObject *
 358 gdbpy_tui_erase (PyObject *self, PyObject *args)
 359 {
 360   gdbpy_tui_window *win = (gdbpy_tui_window *) self;
 361
 362   REQUIRE_WINDOW (win);
 363
 364   win->window->erase ();
 365
 366   Py_RETURN_NONE;
 367 }
 368
 369 /* Python function that writes some text to a TUI window.  */
 370 static PyObject *
 371 gdbpy_tui_write (PyObject *self, PyObject *args)
 372 {
 373   gdbpy_tui_window *win = (gdbpy_tui_window *) self;
 374   const char *text;
 375
 376   if (!PyArg_ParseTuple (args, "s", &text))
 377     return nullptr;
 378
 379   REQUIRE_WINDOW (win);
 380
 381   win->window->output (text);
 382
 383   Py_RETURN_NONE;
 384 }
 385
 386 /* Return the width of the TUI window.  */
 387 static PyObject *
 388 gdbpy_tui_width (PyObject *self, void *closure)
 389 {
 390   gdbpy_tui_window *win = (gdbpy_tui_window *) self;
 391   REQUIRE_WINDOW (win);
 392   return PyLong_FromLong (win->window->viewport_width ());
 393 }
 394
 395 /* Return the height of the TUI window.  */
 396 static PyObject *
 397 gdbpy_tui_height (PyObject *self, void *closure)
 398 {
 399   gdbpy_tui_window *win = (gdbpy_tui_window *) self;
 400   REQUIRE_WINDOW (win);
 401   return PyLong_FromLong (win->window->viewport_height ());
 402 }
 403
 404 /* Return the title of the TUI window.  */
 405 static PyObject *
 406 gdbpy_tui_title (PyObject *self, void *closure)
 407 {
 408   gdbpy_tui_window *win = (gdbpy_tui_window *) self;
 409   REQUIRE_WINDOW (win);
 410   return host_string_to_python_string (win->window->title.c_str ()).release ();
 411 }
 412
 413 /* Set the title of the TUI window.  */
 414 static int
 415 gdbpy_tui_set_title (PyObject *self, PyObject *newvalue, void *closure)
 416 {
 417   gdbpy_tui_window *win = (gdbpy_tui_window *) self;
 418
 419   if (win->window == nullptr)
 420     {
 421       PyErr_Format (PyExc_RuntimeError, _("TUI window is invalid."));
 422       return -1;
 423     }
 424
 425   if (win->window == nullptr)
 426     {
 427       PyErr_Format (PyExc_TypeError, _("Cannot delete \"title\" attribute."));
 428       return -1;
 429     }
 430
 431   gdb::unique_xmalloc_ptr<char> value
 432     = python_string_to_host_string (newvalue);
 433   if (value == nullptr)
 434     return -1;
 435
 436   win->window->title = value.get ();
 437   return 0;
 438 }
 439
 440 static gdb_PyGetSetDef tui_object_getset[] =
 441 {
 442   { "width", gdbpy_tui_width, NULL, "Width of the window.", NULL },
 443   { "height", gdbpy_tui_height, NULL, "Height of the window.", NULL },
 444   { "title", gdbpy_tui_title, gdbpy_tui_set_title, "Title of the window.",
 445     NULL },
 446   { NULL }  /* Sentinel */
 447 };
 448
 449 static PyMethodDef tui_object_methods[] =
 450 {
 451   { "is_valid", gdbpy_tui_is_valid, METH_NOARGS,
 452     "is_valid () -> Boolean\n\
 453 Return true if this TUI window is valid, false if not." },
 454   { "erase", gdbpy_tui_erase, METH_NOARGS,
 455     "Erase the TUI window." },
 456   { "write", (PyCFunction) gdbpy_tui_write, METH_VARARGS,
 457     "Append a string to the TUI window." },
 458   { NULL } /* Sentinel.  */
 459 };
 460
 461 PyTypeObject gdbpy_tui_window_object_type =
 462 {
 463   PyVarObject_HEAD_INIT (NULL, 0)
 464   "gdb.TuiWindow",                /*tp_name*/
 465   sizeof (gdbpy_tui_window),      /*tp_basicsize*/
 466   0,                              /*tp_itemsize*/
 467   0,                              /*tp_dealloc*/
 468   0,                              /*tp_print*/
 469   0,                              /*tp_getattr*/
 470   0,                              /*tp_setattr*/
 471   0,                              /*tp_compare*/
 472   0,                              /*tp_repr*/
 473   0,                              /*tp_as_number*/
 474   0,                              /*tp_as_sequence*/
 475   0,                              /*tp_as_mapping*/
 476   0,                              /*tp_hash */
 477   0,                              /*tp_call*/
 478   0,                              /*tp_str*/
 479   0,                              /*tp_getattro*/
 480   0,                              /*tp_setattro */
 481   0,                              /*tp_as_buffer*/
 482   Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,  /*tp_flags*/
 483   "GDB TUI window object",        /* tp_doc */
 484   0,                              /* tp_traverse */
 485   0,                              /* tp_clear */
 486   0,                              /* tp_richcompare */
 487   0,                              /* tp_weaklistoffset */
 488   0,                              /* tp_iter */
 489   0,                              /* tp_iternext */
 490   tui_object_methods,             /* tp_methods */
 491   0,                              /* tp_members */
 492   tui_object_getset,              /* tp_getset */
 493   0,                              /* tp_base */
 494   0,                              /* tp_dict */
 495   0,                              /* tp_descr_get */
 496   0,                              /* tp_descr_set */
 497   0,                              /* tp_dictoffset */
 498   0,                              /* tp_init */
 499   0,                              /* tp_alloc */
 500 };
 501
 502 #endif /* TUI */
 503
 504 /* Initialize this module.  */
 505
 506 int
 507 gdbpy_initialize_tui ()
 508 {
 509 #ifdef TUI
 510   gdbpy_tui_window_object_type.tp_new = PyType_GenericNew;
 511   if (PyType_Ready (&gdbpy_tui_window_object_type) < 0)
 512     return -1;
 513 #endif  /* TUI */
 514
 515   return 0;
 516 }