gdb/tui/tui-disasm.c

   1 /* Disassembly display.
   2
   3    Copyright (C) 1998-2019 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 "symtab.h"
  25 #include "breakpoint.h"
  26 #include "frame.h"
  27 #include "value.h"
  28 #include "source.h"
  29 #include "disasm.h"
  30 #include "tui/tui.h"
  31 #include "tui/tui-data.h"
  32 #include "tui/tui-win.h"
  33 #include "tui/tui-layout.h"
  34 #include "tui/tui-winsource.h"
  35 #include "tui/tui-stack.h"
  36 #include "tui/tui-file.h"
  37 #include "tui/tui-disasm.h"
  38 #include "progspace.h"
  39 #include "objfiles.h"
  40
  41 #include "gdb_curses.h"
  42
  43 struct tui_asm_line
  44 {
  45   CORE_ADDR addr;
  46   char *addr_string;
  47   char *insn;
  48 };
  49
  50 /* Function to set the disassembly window's content.
  51    Disassemble count lines starting at pc.
  52    Return address of the count'th instruction after pc.  */
  53 static CORE_ADDR
  54 tui_disassemble (struct gdbarch *gdbarch, struct tui_asm_line *asm_lines,
  55                  CORE_ADDR pc, int count)
  56 {
  57   string_file gdb_dis_out;
  58
  59   /* Now construct each line.  */
  60   for (; count > 0; count--, asm_lines++)
  61     {
  62       if (asm_lines->addr_string)
  63         xfree (asm_lines->addr_string);
  64       if (asm_lines->insn)
  65         xfree (asm_lines->insn);
  66
  67       print_address (gdbarch, pc, &gdb_dis_out);
  68       asm_lines->addr = pc;
  69       asm_lines->addr_string = xstrdup (gdb_dis_out.c_str ());
  70
  71       gdb_dis_out.clear ();
  72
  73       pc = pc + gdb_print_insn (gdbarch, pc, &gdb_dis_out, NULL);
  74
  75       asm_lines->insn = xstrdup (gdb_dis_out.c_str ());
  76
  77       /* Reset the buffer to empty.  */
  78       gdb_dis_out.clear ();
  79     }
  80   return pc;
  81 }
  82
  83 /* Find the disassembly address that corresponds to FROM lines above
  84    or below the PC.  Variable sized instructions are taken into
  85    account by the algorithm.  */
  86 static CORE_ADDR
  87 tui_find_disassembly_address (struct gdbarch *gdbarch, CORE_ADDR pc, int from)
  88 {
  89   CORE_ADDR new_low;
  90   int max_lines;
  91   int i;
  92   struct tui_asm_line *asm_lines;
  93
  94   max_lines = (from > 0) ? from : - from;
  95   if (max_lines <= 1)
  96      return pc;
  97
  98   asm_lines = XALLOCAVEC (struct tui_asm_line, max_lines);
  99   memset (asm_lines, 0, sizeof (struct tui_asm_line) * max_lines);
 100
 101   new_low = pc;
 102   if (from > 0)
 103     {
 104       tui_disassemble (gdbarch, asm_lines, pc, max_lines);
 105       new_low = asm_lines[max_lines - 1].addr;
 106     }
 107   else
 108     {
 109       CORE_ADDR last_addr;
 110       int pos;
 111       struct bound_minimal_symbol msymbol;
 112
 113       /* Find backward an address which is a symbol and for which
 114          disassembling from that address will fill completely the
 115          window.  */
 116       pos = max_lines - 1;
 117       do {
 118          new_low -= 1 * max_lines;
 119          msymbol = lookup_minimal_symbol_by_pc_section (new_low, 0);
 120
 121          if (msymbol.minsym)
 122             new_low = BMSYMBOL_VALUE_ADDRESS (msymbol);
 123          else
 124             new_low += 1 * max_lines;
 125
 126          tui_disassemble (gdbarch, asm_lines, new_low, max_lines);
 127          last_addr = asm_lines[pos].addr;
 128       } while (last_addr > pc && msymbol.minsym);
 129
 130       /* Scan forward disassembling one instruction at a time until
 131          the last visible instruction of the window matches the pc.
 132          We keep the disassembled instructions in the 'lines' window
 133          and shift it downward (increasing its addresses).  */
 134       if (last_addr < pc)
 135         do
 136           {
 137             CORE_ADDR next_addr;
 138
 139             pos++;
 140             if (pos >= max_lines)
 141               pos = 0;
 142
 143             next_addr = tui_disassemble (gdbarch, &asm_lines[pos],
 144                                          last_addr, 1);
 145
 146             /* If there are some problems while disassembling exit.  */
 147             if (next_addr <= last_addr)
 148               break;
 149             last_addr = next_addr;
 150           } while (last_addr <= pc);
 151       pos++;
 152       if (pos >= max_lines)
 153          pos = 0;
 154       new_low = asm_lines[pos].addr;
 155     }
 156   for (i = 0; i < max_lines; i++)
 157     {
 158       xfree (asm_lines[i].addr_string);
 159       xfree (asm_lines[i].insn);
 160     }
 161   return new_low;
 162 }
 163
 164 /* Function to set the disassembly window's content.  */
 165 enum tui_status
 166 tui_set_disassem_content (struct gdbarch *gdbarch, CORE_ADDR pc)
 167 {
 168   enum tui_status ret = TUI_FAILURE;
 169   int i;
 170   int offset = TUI_DISASM_WIN->horizontal_offset;
 171   int max_lines, line_width;
 172   CORE_ADDR cur_pc;
 173   struct tui_gen_win_info *locator = tui_locator_win_info_ptr ();
 174   int tab_len = tui_tab_width;
 175   struct tui_asm_line *asm_lines;
 176   int insn_pos;
 177   int addr_size, insn_size;
 178   char *line;
 179
 180   if (pc == 0)
 181     return TUI_FAILURE;
 182
 183   ret = tui_alloc_source_buffer (TUI_DISASM_WIN);
 184   if (ret != TUI_SUCCESS)
 185     return ret;
 186
 187   tui_source_window_base *base = TUI_DISASM_WIN;
 188   base->gdbarch = gdbarch;
 189   base->start_line_or_addr.loa = LOA_ADDRESS;
 190   base->start_line_or_addr.u.addr = pc;
 191   cur_pc = locator->content[0]->which_element.locator.addr;
 192
 193   /* Window size, excluding highlight box.  */
 194   max_lines = TUI_DISASM_WIN->height - 2;
 195   line_width = TUI_DISASM_WIN->width - 2;
 196
 197   /* Get temporary table that will hold all strings (addr & insn).  */
 198   asm_lines = XALLOCAVEC (struct tui_asm_line, max_lines);
 199   memset (asm_lines, 0, sizeof (struct tui_asm_line) * max_lines);
 200
 201   tui_disassemble (gdbarch, asm_lines, pc, max_lines);
 202
 203   /* Determine maximum address- and instruction lengths.  */
 204   addr_size = 0;
 205   insn_size = 0;
 206   for (i = 0; i < max_lines; i++)
 207     {
 208       size_t len = strlen (asm_lines[i].addr_string);
 209
 210       if (len > addr_size)
 211         addr_size = len;
 212
 213       len = strlen (asm_lines[i].insn);
 214       if (len > insn_size)
 215         insn_size = len;
 216     }
 217
 218   /* Align instructions to the same column.  */
 219   insn_pos = (1 + (addr_size / tab_len)) * tab_len;
 220
 221   /* Allocate memory to create each line.  */
 222   line = (char*) alloca (insn_pos + insn_size + 1);
 223
 224   /* Now construct each line.  */
 225   for (i = 0; i < max_lines; i++)
 226     {
 227       struct tui_win_element *element;
 228       struct tui_source_element *src;
 229       int cur_len;
 230
 231       element = TUI_DISASM_WIN->content[i];
 232       src = &element->which_element.source;
 233       strcpy (line, asm_lines[i].addr_string);
 234       cur_len = strlen (line);
 235       memset (line + cur_len, ' ', insn_pos - cur_len);
 236       strcpy (line + insn_pos, asm_lines[i].insn);
 237
 238       /* Now copy the line taking the offset into account.  */
 239       if (strlen (line) > offset)
 240         {
 241           strncpy (src->line, &line[offset], line_width);
 242           src->line[line_width] = '\0';
 243         }
 244       else
 245         src->line[0] = '\0';
 246
 247       src->line_or_addr.loa = LOA_ADDRESS;
 248       src->line_or_addr.u.addr = asm_lines[i].addr;
 249       src->is_exec_point = asm_lines[i].addr == cur_pc;
 250
 251       /* See whether there is a breakpoint installed.  */
 252       src->has_break = (!src->is_exec_point
 253                         && breakpoint_here_p (current_program_space->aspace,
 254                                               pc)
 255                         != no_breakpoint_here);
 256
 257       xfree (asm_lines[i].addr_string);
 258       xfree (asm_lines[i].insn);
 259     }
 260   TUI_DISASM_WIN->content_size = i;
 261   return TUI_SUCCESS;
 262 }
 263
 264
 265 /* Function to display the disassembly window with disassembled code.  */
 266 void
 267 tui_show_disassem (struct gdbarch *gdbarch, CORE_ADDR start_addr)
 268 {
 269   struct symtab *s = find_pc_line_symtab (start_addr);
 270   struct tui_win_info *win_with_focus = tui_win_with_focus ();
 271   struct tui_line_or_address val;
 272
 273   val.loa = LOA_ADDRESS;
 274   val.u.addr = start_addr;
 275   tui_add_win_to_layout (DISASSEM_WIN);
 276   tui_update_source_window (TUI_DISASM_WIN, gdbarch, s, val, FALSE);
 277
 278   /* If the focus was in the src win, put it in the asm win, if the
 279      source view isn't split.  */
 280   if (tui_current_layout () != SRC_DISASSEM_COMMAND
 281       && win_with_focus == TUI_SRC_WIN)
 282     tui_set_win_focus_to (TUI_DISASM_WIN);
 283
 284   return;
 285 }
 286
 287
 288 /* Function to display the disassembly window.  */
 289 void
 290 tui_show_disassem_and_update_source (struct gdbarch *gdbarch,
 291                                      CORE_ADDR start_addr)
 292 {
 293   struct symtab_and_line sal;
 294
 295   tui_show_disassem (gdbarch, start_addr);
 296   if (tui_current_layout () == SRC_DISASSEM_COMMAND)
 297     {
 298       struct tui_line_or_address val;
 299
 300       /* Update what is in the source window if it is displayed too,
 301          note that it follows what is in the disassembly window and
 302          visa-versa.  */
 303       sal = find_pc_line (start_addr, 0);
 304       val.loa = LOA_LINE;
 305       val.u.line_no = sal.line;
 306       tui_update_source_window (TUI_SRC_WIN, gdbarch, sal.symtab, val, TRUE);
 307       if (sal.symtab)
 308         {
 309           set_current_source_symtab_and_line (sal);
 310           tui_update_locator_fullname (symtab_to_fullname (sal.symtab));
 311         }
 312       else
 313         tui_update_locator_fullname ("?");
 314     }
 315
 316   return;
 317 }
 318
 319 void
 320 tui_get_begin_asm_address (struct gdbarch **gdbarch_p, CORE_ADDR *addr_p)
 321 {
 322   struct tui_gen_win_info *locator;
 323   struct tui_locator_element *element;
 324   struct gdbarch *gdbarch = get_current_arch ();
 325   CORE_ADDR addr;
 326
 327   locator = tui_locator_win_info_ptr ();
 328   element = &locator->content[0]->which_element.locator;
 329
 330   if (element->addr == 0)
 331     {
 332       struct bound_minimal_symbol main_symbol;
 333
 334       /* Find address of the start of program.
 335          Note: this should be language specific.  */
 336       main_symbol = lookup_minimal_symbol ("main", NULL, NULL);
 337       if (main_symbol.minsym == 0)
 338         main_symbol = lookup_minimal_symbol ("MAIN", NULL, NULL);
 339       if (main_symbol.minsym == 0)
 340         main_symbol = lookup_minimal_symbol ("_start", NULL, NULL);
 341       if (main_symbol.minsym)
 342         addr = BMSYMBOL_VALUE_ADDRESS (main_symbol);
 343       else
 344         addr = 0;
 345     }
 346   else                          /* The target is executing.  */
 347     {
 348       gdbarch = element->gdbarch;
 349       addr = element->addr;
 350     }
 351
 352   *gdbarch_p = gdbarch;
 353   *addr_p = addr;
 354 }
 355
 356 /* Determine what the low address will be to display in the TUI's
 357    disassembly window.  This may or may not be the same as the low
 358    address input.  */
 359 CORE_ADDR
 360 tui_get_low_disassembly_address (struct gdbarch *gdbarch,
 361                                  CORE_ADDR low, CORE_ADDR pc)
 362 {
 363   int pos;
 364
 365   /* Determine where to start the disassembly so that the pc is about
 366      in the middle of the viewport.  */
 367   pos = tui_default_win_viewport_height (DISASSEM_WIN, DISASSEM_COMMAND) / 2;
 368   pc = tui_find_disassembly_address (gdbarch, pc, -pos);
 369
 370   if (pc < low)
 371     pc = low;
 372   return pc;
 373 }
 374
 375 /* Scroll the disassembly forward or backward vertically.  */
 376 void
 377 tui_disasm_window::do_scroll_vertical
 378   (enum tui_scroll_direction scroll_direction, int num_to_scroll)
 379 {
 380   if (content != NULL)
 381     {
 382       CORE_ADDR pc;
 383       struct tui_line_or_address val;
 384       int dir;
 385
 386       pc = content[0]->which_element.source.line_or_addr.u.addr;
 387       num_to_scroll++;
 388       dir = (scroll_direction == FORWARD_SCROLL)
 389         ? num_to_scroll : -num_to_scroll;
 390
 391       val.loa = LOA_ADDRESS;
 392       val.u.addr = tui_find_disassembly_address (gdbarch, pc, dir);
 393       tui_update_source_window_as_is (this, gdbarch,
 394                                       NULL, val, FALSE);
 395     }
 396 }