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   int i;
 169   int offset = TUI_DISASM_WIN->horizontal_offset;
 170   int max_lines, line_width;
 171   CORE_ADDR cur_pc;
 172   struct tui_locator_window *locator = tui_locator_win_info_ptr ();
 173   int tab_len = tui_tab_width;
 174   struct tui_asm_line *asm_lines;
 175   int insn_pos;
 176   int addr_size, insn_size;
 177   char *line;
 178
 179   if (pc == 0)
 180     return TUI_FAILURE;
 181
 182   tui_alloc_source_buffer (TUI_DISASM_WIN);
 183
 184   tui_source_window_base *base = TUI_DISASM_WIN;
 185   base->gdbarch = gdbarch;
 186   base->start_line_or_addr.loa = LOA_ADDRESS;
 187   base->start_line_or_addr.u.addr = pc;
 188   cur_pc = locator->addr;
 189
 190   /* Window size, excluding highlight box.  */
 191   max_lines = TUI_DISASM_WIN->height - 2;
 192   line_width = TUI_DISASM_WIN->width - 2;
 193
 194   /* Get temporary table that will hold all strings (addr & insn).  */
 195   asm_lines = XALLOCAVEC (struct tui_asm_line, max_lines);
 196   memset (asm_lines, 0, sizeof (struct tui_asm_line) * max_lines);
 197
 198   tui_disassemble (gdbarch, asm_lines, pc, max_lines);
 199
 200   /* Determine maximum address- and instruction lengths.  */
 201   addr_size = 0;
 202   insn_size = 0;
 203   for (i = 0; i < max_lines; i++)
 204     {
 205       size_t len = strlen (asm_lines[i].addr_string);
 206
 207       if (len > addr_size)
 208         addr_size = len;
 209
 210       len = strlen (asm_lines[i].insn);
 211       if (len > insn_size)
 212         insn_size = len;
 213     }
 214
 215   /* Align instructions to the same column.  */
 216   insn_pos = (1 + (addr_size / tab_len)) * tab_len;
 217
 218   /* Allocate memory to create each line.  */
 219   line = (char*) alloca (insn_pos + insn_size + 1);
 220
 221   /* Now construct each line.  */
 222   TUI_DISASM_WIN->content.resize (max_lines);
 223   for (i = 0; i < max_lines; i++)
 224     {
 225       int cur_len;
 226
 227       tui_source_element *src = &TUI_DISASM_WIN->content[i];
 228       strcpy (line, asm_lines[i].addr_string);
 229       cur_len = strlen (line);
 230       memset (line + cur_len, ' ', insn_pos - cur_len);
 231       strcpy (line + insn_pos, asm_lines[i].insn);
 232
 233       /* Now copy the line taking the offset into account.  */
 234       xfree (src->line);
 235       if (strlen (line) > offset)
 236         src->line = xstrndup (&line[offset], line_width);
 237       else
 238         src->line = xstrdup ("");
 239
 240       src->line_or_addr.loa = LOA_ADDRESS;
 241       src->line_or_addr.u.addr = asm_lines[i].addr;
 242       src->is_exec_point = asm_lines[i].addr == cur_pc;
 243
 244       /* See whether there is a breakpoint installed.  */
 245       src->has_break = (!src->is_exec_point
 246                         && breakpoint_here_p (current_program_space->aspace,
 247                                               pc)
 248                         != no_breakpoint_here);
 249
 250       xfree (asm_lines[i].addr_string);
 251       xfree (asm_lines[i].insn);
 252     }
 253   return TUI_SUCCESS;
 254 }
 255
 256
 257 /* Function to display the disassembly window with disassembled code.  */
 258 void
 259 tui_show_disassem (struct gdbarch *gdbarch, CORE_ADDR start_addr)
 260 {
 261   struct symtab *s = find_pc_line_symtab (start_addr);
 262   struct tui_win_info *win_with_focus = tui_win_with_focus ();
 263   struct tui_line_or_address val;
 264
 265   val.loa = LOA_ADDRESS;
 266   val.u.addr = start_addr;
 267   tui_add_win_to_layout (DISASSEM_WIN);
 268   tui_update_source_window (TUI_DISASM_WIN, gdbarch, s, val, FALSE);
 269
 270   /* If the focus was in the src win, put it in the asm win, if the
 271      source view isn't split.  */
 272   if (tui_current_layout () != SRC_DISASSEM_COMMAND
 273       && win_with_focus == TUI_SRC_WIN)
 274     tui_set_win_focus_to (TUI_DISASM_WIN);
 275
 276   return;
 277 }
 278
 279
 280 /* Function to display the disassembly window.  */
 281 void
 282 tui_show_disassem_and_update_source (struct gdbarch *gdbarch,
 283                                      CORE_ADDR start_addr)
 284 {
 285   struct symtab_and_line sal;
 286
 287   tui_show_disassem (gdbarch, start_addr);
 288   if (tui_current_layout () == SRC_DISASSEM_COMMAND)
 289     {
 290       struct tui_line_or_address val;
 291
 292       /* Update what is in the source window if it is displayed too,
 293          note that it follows what is in the disassembly window and
 294          visa-versa.  */
 295       sal = find_pc_line (start_addr, 0);
 296       val.loa = LOA_LINE;
 297       val.u.line_no = sal.line;
 298       tui_update_source_window (TUI_SRC_WIN, gdbarch, sal.symtab, val, TRUE);
 299       if (sal.symtab)
 300         {
 301           set_current_source_symtab_and_line (sal);
 302           tui_update_locator_fullname (symtab_to_fullname (sal.symtab));
 303         }
 304       else
 305         tui_update_locator_fullname ("?");
 306     }
 307
 308   return;
 309 }
 310
 311 void
 312 tui_get_begin_asm_address (struct gdbarch **gdbarch_p, CORE_ADDR *addr_p)
 313 {
 314   struct tui_locator_window *locator;
 315   struct gdbarch *gdbarch = get_current_arch ();
 316   CORE_ADDR addr;
 317
 318   locator = tui_locator_win_info_ptr ();
 319
 320   if (locator->addr == 0)
 321     {
 322       struct bound_minimal_symbol main_symbol;
 323
 324       /* Find address of the start of program.
 325          Note: this should be language specific.  */
 326       main_symbol = lookup_minimal_symbol ("main", NULL, NULL);
 327       if (main_symbol.minsym == 0)
 328         main_symbol = lookup_minimal_symbol ("MAIN", NULL, NULL);
 329       if (main_symbol.minsym == 0)
 330         main_symbol = lookup_minimal_symbol ("_start", NULL, NULL);
 331       if (main_symbol.minsym)
 332         addr = BMSYMBOL_VALUE_ADDRESS (main_symbol);
 333       else
 334         addr = 0;
 335     }
 336   else                          /* The target is executing.  */
 337     {
 338       gdbarch = locator->gdbarch;
 339       addr = locator->addr;
 340     }
 341
 342   *gdbarch_p = gdbarch;
 343   *addr_p = addr;
 344 }
 345
 346 /* Determine what the low address will be to display in the TUI's
 347    disassembly window.  This may or may not be the same as the low
 348    address input.  */
 349 CORE_ADDR
 350 tui_get_low_disassembly_address (struct gdbarch *gdbarch,
 351                                  CORE_ADDR low, CORE_ADDR pc)
 352 {
 353   int pos;
 354
 355   /* Determine where to start the disassembly so that the pc is about
 356      in the middle of the viewport.  */
 357   pos = tui_default_win_viewport_height (DISASSEM_WIN, DISASSEM_COMMAND) / 2;
 358   pc = tui_find_disassembly_address (gdbarch, pc, -pos);
 359
 360   if (pc < low)
 361     pc = low;
 362   return pc;
 363 }
 364
 365 /* Scroll the disassembly forward or backward vertically.  */
 366 void
 367 tui_disasm_window::do_scroll_vertical (int num_to_scroll)
 368 {
 369   if (!content.empty ())
 370     {
 371       CORE_ADDR pc;
 372       struct tui_line_or_address val;
 373
 374       pc = content[0].line_or_addr.u.addr;
 375       if (num_to_scroll >= 0)
 376         num_to_scroll++;
 377       else
 378         --num_to_scroll;
 379
 380       val.loa = LOA_ADDRESS;
 381       val.u.addr = tui_find_disassembly_address (gdbarch, pc, num_to_scroll);
 382       tui_update_source_window_as_is (this, gdbarch,
 383                                       NULL, val, FALSE);
 384     }
 385 }