gdb/tui/tui-regs.c

   1 /* TUI display registers in window.
   2
   3    Copyright (C) 1998-2021 Free Software Foundation, Inc.
   4
   5    Contributed by Hewlett-Packard Company.
   6
   7    This file is part of GDB.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22 #include "defs.h"
  23 #include "arch-utils.h"
  24 #include "tui/tui.h"
  25 #include "tui/tui-data.h"
  26 #include "symtab.h"
  27 #include "gdbtypes.h"
  28 #include "gdbcmd.h"
  29 #include "frame.h"
  30 #include "regcache.h"
  31 #include "inferior.h"
  32 #include "target.h"
  33 #include "tui/tui-layout.h"
  34 #include "tui/tui-win.h"
  35 #include "tui/tui-wingeneral.h"
  36 #include "tui/tui-file.h"
  37 #include "tui/tui-regs.h"
  38 #include "tui/tui-io.h"
  39 #include "reggroups.h"
  40 #include "valprint.h"
  41 #include "completer.h"
  42
  43 #include "gdb_curses.h"
  44
  45 /* A subclass of string_file that expands tab characters.  */
  46 class tab_expansion_file : public string_file
  47 {
  48 public:
  49
  50   tab_expansion_file () = default;
  51
  52   void write (const char *buf, long length_buf) override;
  53
  54 private:
  55
  56   int m_column = 0;
  57 };
  58
  59 void
  60 tab_expansion_file::write (const char *buf, long length_buf)
  61 {
  62   for (long i = 0; i < length_buf; ++i)
  63     {
  64       if (buf[i] == '\t')
  65         {
  66           do
  67             {
  68               string_file::write (" ", 1);
  69               ++m_column;
  70             }
  71           while ((m_column % 8) != 0);
  72         }
  73       else
  74         {
  75           string_file::write (&buf[i], 1);
  76           if (buf[i] == '\n')
  77             m_column = 0;
  78           else
  79             ++m_column;
  80         }
  81     }
  82 }
  83
  84 /* Get the register from the frame and return a printable
  85    representation of it.  */
  86
  87 static std::string
  88 tui_register_format (struct frame_info *frame, int regnum)
  89 {
  90   struct gdbarch *gdbarch = get_frame_arch (frame);
  91
  92   /* Expand tabs into spaces, since ncurses on MS-Windows doesn't.  */
  93   tab_expansion_file stream;
  94
  95   scoped_restore save_pagination
  96     = make_scoped_restore (&pagination_enabled, 0);
  97   scoped_restore save_stdout
  98     = make_scoped_restore (&gdb_stdout, &stream);
  99
 100   gdbarch_print_registers_info (gdbarch, &stream, frame, regnum, 1);
 101
 102   /* Remove the possible \n.  */
 103   std::string &str = stream.string ();
 104   if (!str.empty () && str.back () == '\n')
 105     str.resize (str.size () - 1);
 106
 107   return str;
 108 }
 109
 110 /* Get the register value from the given frame and format it for the
 111    display.  When changep is set, check if the new register value has
 112    changed with respect to the previous call.  */
 113 static void
 114 tui_get_register (struct frame_info *frame,
 115                   struct tui_data_item_window *data,
 116                   int regnum, bool *changedp)
 117 {
 118   if (changedp)
 119     *changedp = false;
 120   if (target_has_registers ())
 121     {
 122       std::string new_content = tui_register_format (frame, regnum);
 123
 124       if (changedp != NULL && data->content != new_content)
 125         *changedp = true;
 126
 127       data->content = std::move (new_content);
 128     }
 129 }
 130
 131 /* See tui-regs.h.  */
 132
 133 int
 134 tui_data_window::last_regs_line_no () const
 135 {
 136   int num_lines = m_regs_content.size () / m_regs_column_count;
 137   if (m_regs_content.size () % m_regs_column_count)
 138     num_lines++;
 139   return num_lines;
 140 }
 141
 142 /* See tui-regs.h.  */
 143
 144 int
 145 tui_data_window::line_from_reg_element_no (int element_no) const
 146 {
 147   if (element_no < m_regs_content.size ())
 148     {
 149       int i, line = (-1);
 150
 151       i = 1;
 152       while (line == (-1))
 153         {
 154           if (element_no < m_regs_column_count * i)
 155             line = i - 1;
 156           else
 157             i++;
 158         }
 159
 160       return line;
 161     }
 162   else
 163     return (-1);
 164 }
 165
 166 /* See tui-regs.h.  */
 167
 168 int
 169 tui_data_window::first_reg_element_no_inline (int line_no) const
 170 {
 171   if (line_no * m_regs_column_count <= m_regs_content.size ())
 172     return ((line_no + 1) * m_regs_column_count) - m_regs_column_count;
 173   else
 174     return (-1);
 175 }
 176
 177 /* Show the registers of the given group in the data window
 178    and refresh the window.  */
 179 void
 180 tui_data_window::show_registers (struct reggroup *group)
 181 {
 182   if (group == 0)
 183     group = general_reggroup;
 184
 185   if (target_has_registers () && target_has_stack () && target_has_memory ())
 186     {
 187       show_register_group (group, get_selected_frame (NULL),
 188                            group == m_current_group);
 189
 190       /* Clear all notation of changed values.  */
 191       for (auto &&data_item_win : m_regs_content)
 192         data_item_win.highlight = false;
 193       m_current_group = group;
 194     }
 195   else
 196     {
 197       m_current_group = 0;
 198       m_regs_content.clear ();
 199     }
 200
 201   rerender ();
 202 }
 203
 204
 205 /* Set the data window to display the registers of the register group
 206    using the given frame.  Values are refreshed only when
 207    refresh_values_only is true.  */
 208
 209 void
 210 tui_data_window::show_register_group (struct reggroup *group,
 211                                       struct frame_info *frame,
 212                                       bool refresh_values_only)
 213 {
 214   struct gdbarch *gdbarch = get_frame_arch (frame);
 215   int nr_regs;
 216   int regnum, pos;
 217
 218   /* Make a new title showing which group we display.  */
 219   title = string_printf ("Register group: %s", reggroup_name (group));
 220
 221   /* See how many registers must be displayed.  */
 222   nr_regs = 0;
 223   for (regnum = 0; regnum < gdbarch_num_cooked_regs (gdbarch); regnum++)
 224     {
 225       const char *name;
 226
 227       /* Must be in the group.  */
 228       if (!gdbarch_register_reggroup_p (gdbarch, regnum, group))
 229         continue;
 230
 231       /* If the register name is empty, it is undefined for this
 232          processor, so don't display anything.  */
 233       name = gdbarch_register_name (gdbarch, regnum);
 234       if (name == 0 || *name == '\0')
 235         continue;
 236
 237       nr_regs++;
 238     }
 239
 240   m_regs_content.resize (nr_regs);
 241
 242   /* Now set the register names and values.  */
 243   pos = 0;
 244   for (regnum = 0; regnum < gdbarch_num_cooked_regs (gdbarch); regnum++)
 245     {
 246       struct tui_data_item_window *data_item_win;
 247       const char *name;
 248
 249       /* Must be in the group.  */
 250       if (!gdbarch_register_reggroup_p (gdbarch, regnum, group))
 251         continue;
 252
 253       /* If the register name is empty, it is undefined for this
 254          processor, so don't display anything.  */
 255       name = gdbarch_register_name (gdbarch, regnum);
 256       if (name == 0 || *name == '\0')
 257         continue;
 258
 259       data_item_win = &m_regs_content[pos];
 260       if (!refresh_values_only)
 261         {
 262           data_item_win->regno = regnum;
 263           data_item_win->highlight = false;
 264         }
 265       tui_get_register (frame, data_item_win, regnum, 0);
 266       pos++;
 267     }
 268 }
 269
 270 /* See tui-regs.h.  */
 271
 272 void
 273 tui_data_window::display_registers_from (int start_element_no)
 274 {
 275   int max_len = 0;
 276   for (auto &&data_item_win : m_regs_content)
 277     {
 278       int len = data_item_win.content.size ();
 279
 280       if (len > max_len)
 281         max_len = len;
 282     }
 283   m_item_width = max_len + 1;
 284
 285   int i;
 286   /* Mark register windows above the visible area.  */
 287   for (i = 0; i < start_element_no; i++)
 288     m_regs_content[i].y = 0;
 289
 290   m_regs_column_count = (width - 2) / m_item_width;
 291   if (m_regs_column_count == 0)
 292     m_regs_column_count = 1;
 293   m_item_width = (width - 2) / m_regs_column_count;
 294
 295   /* Now create each data "sub" window, and write the display into
 296      it.  */
 297   int cur_y = 1;
 298   while (i < m_regs_content.size () && cur_y <= height - 2)
 299     {
 300       for (int j = 0;
 301            j < m_regs_column_count && i < m_regs_content.size ();
 302            j++)
 303         {
 304           /* Create the window if necessary.  */
 305           m_regs_content[i].x = (m_item_width * j) + 1;
 306           m_regs_content[i].y = cur_y;
 307           m_regs_content[i].visible = true;
 308           m_regs_content[i].rerender (handle.get (), m_item_width);
 309           i++;          /* Next register.  */
 310         }
 311       cur_y++;          /* Next row.  */
 312     }
 313
 314   /* Mark register windows below the visible area.  */
 315   for (; i < m_regs_content.size (); i++)
 316     m_regs_content[i].y = 0;
 317
 318   refresh_window ();
 319 }
 320
 321 /* See tui-regs.h.  */
 322
 323 void
 324 tui_data_window::display_reg_element_at_line (int start_element_no,
 325                                               int start_line_no)
 326 {
 327   int element_no = start_element_no;
 328
 329   if (start_element_no != 0 && start_line_no != 0)
 330     {
 331       int last_line_no, first_line_on_last_page;
 332
 333       last_line_no = last_regs_line_no ();
 334       first_line_on_last_page = last_line_no - (height - 2);
 335       if (first_line_on_last_page < 0)
 336         first_line_on_last_page = 0;
 337
 338       /* If the element_no causes us to scroll past the end of the
 339          registers, adjust what element to really start the
 340          display at.  */
 341       if (start_line_no > first_line_on_last_page)
 342         element_no = first_reg_element_no_inline (first_line_on_last_page);
 343     }
 344   display_registers_from (element_no);
 345 }
 346
 347 /* See tui-regs.h.  */
 348
 349 int
 350 tui_data_window::display_registers_from_line (int line_no)
 351 {
 352   int element_no;
 353
 354   if (line_no < 0)
 355     line_no = 0;
 356   else
 357     {
 358       /* Make sure that we don't display off the end of the
 359          registers.  */
 360       if (line_no >= last_regs_line_no ())
 361         {
 362           line_no = line_from_reg_element_no (m_regs_content.size () - 1);
 363           if (line_no < 0)
 364             line_no = 0;
 365         }
 366     }
 367
 368   element_no = first_reg_element_no_inline (line_no);
 369   if (element_no < m_regs_content.size ())
 370     display_reg_element_at_line (element_no, line_no);
 371   else
 372     line_no = (-1);
 373
 374   return line_no;
 375 }
 376
 377
 378 /* Answer the index first element displayed.  If none are displayed,
 379    then return (-1).  */
 380 int
 381 tui_data_window::first_data_item_displayed ()
 382 {
 383   for (int i = 0; i < m_regs_content.size (); i++)
 384     {
 385       if (m_regs_content[i].visible)
 386         return i;
 387     }
 388
 389   return -1;
 390 }
 391
 392 /* See tui-regs.h.  */
 393
 394 void
 395 tui_data_window::delete_data_content_windows ()
 396 {
 397   for (auto &win : m_regs_content)
 398     win.visible = false;
 399 }
 400
 401
 402 void
 403 tui_data_window::erase_data_content (const char *prompt)
 404 {
 405   werase (handle.get ());
 406   check_and_display_highlight_if_needed ();
 407   if (prompt != NULL)
 408     {
 409       int half_width = (width - 2) / 2;
 410       int x_pos;
 411
 412       if (strlen (prompt) >= half_width)
 413         x_pos = 1;
 414       else
 415         x_pos = half_width - strlen (prompt);
 416       mvwaddstr (handle.get (), (height / 2), x_pos, (char *) prompt);
 417     }
 418   tui_wrefresh (handle.get ());
 419 }
 420
 421 /* See tui-regs.h.  */
 422
 423 void
 424 tui_data_window::rerender ()
 425 {
 426   if (m_regs_content.empty ())
 427     erase_data_content (_("[ Register Values Unavailable ]"));
 428   else
 429     {
 430       erase_data_content (NULL);
 431       delete_data_content_windows ();
 432       display_registers_from (0);
 433     }
 434 }
 435
 436
 437 /* Scroll the data window vertically forward or backward.  */
 438 void
 439 tui_data_window::do_scroll_vertical (int num_to_scroll)
 440 {
 441   int first_element_no;
 442   int first_line = (-1);
 443
 444   first_element_no = first_data_item_displayed ();
 445   if (first_element_no < m_regs_content.size ())
 446     first_line = line_from_reg_element_no (first_element_no);
 447   else
 448     { /* Calculate the first line from the element number which is in
 449         the general data content.  */
 450     }
 451
 452   if (first_line >= 0)
 453     {
 454       first_line += num_to_scroll;
 455       erase_data_content (NULL);
 456       delete_data_content_windows ();
 457       display_registers_from_line (first_line);
 458     }
 459 }
 460
 461 /* This function check all displayed registers for changes in values,
 462    given a particular frame.  If the values have changed, they are
 463    updated with the new value and highlighted.  */
 464 void
 465 tui_data_window::check_register_values (struct frame_info *frame)
 466 {
 467   if (m_regs_content.empty ())
 468     show_registers (m_current_group);
 469   else
 470     {
 471       for (auto &&data_item_win : m_regs_content)
 472         {
 473           int was_hilighted;
 474
 475           was_hilighted = data_item_win.highlight;
 476
 477           tui_get_register (frame, &data_item_win,
 478                             data_item_win.regno,
 479                             &data_item_win.highlight);
 480
 481           /* Register windows whose y == 0 are outside the visible area.  */
 482           if ((data_item_win.highlight || was_hilighted)
 483               && data_item_win.y > 0)
 484             data_item_win.rerender (handle.get (), m_item_width);
 485         }
 486     }
 487
 488   tui_wrefresh (handle.get ());
 489 }
 490
 491 /* Display a register in a window.  If hilite is TRUE, then the value
 492    will be displayed in reverse video.  */
 493 void
 494 tui_data_item_window::rerender (WINDOW *handle, int field_width)
 495 {
 496   if (highlight)
 497     /* We ignore the return value, casting it to void in order to avoid
 498        a compiler warning.  The warning itself was introduced by a patch
 499        to ncurses 5.7 dated 2009-08-29, changing this macro to expand
 500        to code that causes the compiler to generate an unused-value
 501        warning.  */
 502     (void) wstandout (handle);
 503
 504   mvwaddnstr (handle, y, x, content.c_str (), field_width - 1);
 505   if (content.size () < field_width)
 506     waddstr (handle, n_spaces (field_width - content.size ()));
 507
 508   if (highlight)
 509     /* We ignore the return value, casting it to void in order to avoid
 510        a compiler warning.  The warning itself was introduced by a patch
 511        to ncurses 5.7 dated 2009-08-29, changing this macro to expand
 512        to code that causes the compiler to generate an unused-value
 513        warning.  */
 514     (void) wstandend (handle);
 515 }
 516
 517 /* Helper for "tui reg next", wraps a call to REGGROUP_NEXT, but adds wrap
 518    around behaviour.  Returns the next register group, or NULL if the
 519    register window is not currently being displayed.  */
 520
 521 static struct reggroup *
 522 tui_reg_next (struct reggroup *current_group, struct gdbarch *gdbarch)
 523 {
 524   struct reggroup *group = NULL;
 525
 526   if (current_group != NULL)
 527     {
 528       group = reggroup_next (gdbarch, current_group);
 529       if (group == NULL)
 530         group = reggroup_next (gdbarch, NULL);
 531     }
 532   return group;
 533 }
 534
 535 /* Helper for "tui reg prev", wraps a call to REGGROUP_PREV, but adds wrap
 536    around behaviour.  Returns the previous register group, or NULL if the
 537    register window is not currently being displayed.  */
 538
 539 static struct reggroup *
 540 tui_reg_prev (struct reggroup *current_group, struct gdbarch *gdbarch)
 541 {
 542   struct reggroup *group = NULL;
 543
 544   if (current_group != NULL)
 545     {
 546       group = reggroup_prev (gdbarch, current_group);
 547       if (group == NULL)
 548         group = reggroup_prev (gdbarch, NULL);
 549     }
 550   return group;
 551 }
 552
 553 /* Implement the 'tui reg' command.  Changes the register group displayed
 554    in the tui register window.  Displays the tui register window if it is
 555    not already on display.  */
 556
 557 static void
 558 tui_reg_command (const char *args, int from_tty)
 559 {
 560   struct gdbarch *gdbarch = get_current_arch ();
 561
 562   if (args != NULL)
 563     {
 564       struct reggroup *group, *match = NULL;
 565       size_t len = strlen (args);
 566
 567       /* Make sure the curses mode is enabled.  */
 568       tui_enable ();
 569
 570       tui_suppress_output suppress;
 571
 572       /* Make sure the register window is visible.  If not, select an
 573          appropriate layout.  We need to do this before trying to run the
 574          'next' or 'prev' commands.  */
 575       if (TUI_DATA_WIN == NULL || !TUI_DATA_WIN->is_visible ())
 576         tui_regs_layout ();
 577
 578       struct reggroup *current_group = TUI_DATA_WIN->get_current_group ();
 579       if (strncmp (args, "next", len) == 0)
 580         match = tui_reg_next (current_group, gdbarch);
 581       else if (strncmp (args, "prev", len) == 0)
 582         match = tui_reg_prev (current_group, gdbarch);
 583
 584       /* This loop matches on the initial part of a register group
 585          name.  If this initial part in ARGS matches only one register
 586          group then the switch is made.  */
 587       for (group = reggroup_next (gdbarch, NULL);
 588            group != NULL;
 589            group = reggroup_next (gdbarch, group))
 590         {
 591           if (strncmp (reggroup_name (group), args, len) == 0)
 592             {
 593               if (match != NULL)
 594                 error (_("ambiguous register group name '%s'"), args);
 595               match = group;
 596             }
 597         }
 598
 599       if (match == NULL)
 600         error (_("unknown register group '%s'"), args);
 601
 602       TUI_DATA_WIN->show_registers (match);
 603     }
 604   else
 605     {
 606       struct reggroup *group;
 607       int first;
 608
 609       printf_unfiltered (_("\"tui reg\" must be followed by the name of "
 610                            "either a register group,\nor one of 'next' "
 611                            "or 'prev'.  Known register groups are:\n"));
 612
 613       for (first = 1, group = reggroup_next (gdbarch, NULL);
 614            group != NULL;
 615            first = 0, group = reggroup_next (gdbarch, group))
 616         {
 617           if (!first)
 618             printf_unfiltered (", ");
 619           printf_unfiltered ("%s", reggroup_name (group));
 620         }
 621
 622       printf_unfiltered ("\n");
 623     }
 624 }
 625
 626 /* Complete names of register groups, and add the special "prev" and "next"
 627    names.  */
 628
 629 static void
 630 tui_reggroup_completer (struct cmd_list_element *ignore,
 631                         completion_tracker &tracker,
 632                         const char *text, const char *word)
 633 {
 634   static const char * const extra[] = { "next", "prev", NULL };
 635
 636   reggroup_completer (ignore, tracker, text, word);
 637
 638   complete_on_enum (tracker, extra, text, word);
 639 }
 640
 641 void _initialize_tui_regs ();
 642 void
 643 _initialize_tui_regs ()
 644 {
 645   struct cmd_list_element **tuicmd, *cmd;
 646
 647   tuicmd = tui_get_cmd_list ();
 648
 649   cmd = add_cmd ("reg", class_tui, tui_reg_command, _("\
 650 TUI command to control the register window.\n\
 651 Usage: tui reg NAME\n\
 652 NAME is the name of the register group to display"), tuicmd);
 653   set_cmd_completer (cmd, tui_reggroup_completer);
 654 }