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_gen_win_info *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->content[0]->which_element.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   for (i = 0; i < max_lines; i++)
 223     {
 224       struct tui_win_element *element;
 225       struct tui_source_element *src;
 226       int cur_len;
 227
 228       element = TUI_DISASM_WIN->content[i];
 229       src = &element->which_element.source;
 230       strcpy (line, asm_lines[i].addr_string);
 231       cur_len = strlen (line);
 232       memset (line + cur_len, ' ', insn_pos - cur_len);
 233       strcpy (line + insn_pos, asm_lines[i].insn);
 234
 235       /* Now copy the line taking the offset into account.  */
 236       if (strlen (line) > offset)
 237         {
 238           strncpy (src->line, &line[offset], line_width);
 239           src->line[line_width] = '\0';
 240         }
 241       else
 242         src->line[0] = '\0';
 243
 244       src->line_or_addr.loa = LOA_ADDRESS;
 245       src->line_or_addr.u.addr = asm_lines[i].addr;
 246       src->is_exec_point = asm_lines[i].addr == cur_pc;
 247
 248       /* See whether there is a breakpoint installed.  */
 249       src->has_break = (!src->is_exec_point
 250                         && breakpoint_here_p (current_program_space->aspace,
 251                                               pc)
 252                         != no_breakpoint_here);
 253
 254       xfree (asm_lines[i].addr_string);
 255       xfree (asm_lines[i].insn);
 256     }
 257   TUI_DISASM_WIN->content_size = i;
 258   return TUI_SUCCESS;
 259 }
 260
 261
 262 /* Function to display the disassembly window with disassembled code.  */
 263 void
 264 tui_show_disassem (struct gdbarch *gdbarch, CORE_ADDR start_addr)
 265 {
 266   struct symtab *s = find_pc_line_symtab (start_addr);
 267   struct tui_win_info *win_with_focus = tui_win_with_focus ();
 268   struct tui_line_or_address val;
 269
 270   val.loa = LOA_ADDRESS;
 271   val.u.addr = start_addr;
 272   tui_add_win_to_layout (DISASSEM_WIN);
 273   tui_update_source_window (TUI_DISASM_WIN, gdbarch, s, val, FALSE);
 274
 275   /* If the focus was in the src win, put it in the asm win, if the
 276      source view isn't split.  */
 277   if (tui_current_layout () != SRC_DISASSEM_COMMAND
 278       && win_with_focus == TUI_SRC_WIN)
 279     tui_set_win_focus_to (TUI_DISASM_WIN);
 280
 281   return;
 282 }
 283
 284
 285 /* Function to display the disassembly window.  */
 286 void
 287 tui_show_disassem_and_update_source (struct gdbarch *gdbarch,
 288                                      CORE_ADDR start_addr)
 289 {
 290   struct symtab_and_line sal;
 291
 292   tui_show_disassem (gdbarch, start_addr);
 293   if (tui_current_layout () == SRC_DISASSEM_COMMAND)
 294     {
 295       struct tui_line_or_address val;
 296
 297       /* Update what is in the source window if it is displayed too,
 298          note that it follows what is in the disassembly window and
 299          visa-versa.  */
 300       sal = find_pc_line (start_addr, 0);
 301       val.loa = LOA_LINE;
 302       val.u.line_no = sal.line;
 303       tui_update_source_window (TUI_SRC_WIN, gdbarch, sal.symtab, val, TRUE);
 304       if (sal.symtab)
 305         {
 306           set_current_source_symtab_and_line (sal);
 307           tui_update_locator_fullname (symtab_to_fullname (sal.symtab));
 308         }
 309       else
 310         tui_update_locator_fullname ("?");
 311     }
 312
 313   return;
 314 }
 315
 316 void
 317 tui_get_begin_asm_address (struct gdbarch **gdbarch_p, CORE_ADDR *addr_p)
 318 {
 319   struct tui_gen_win_info *locator;
 320   struct tui_locator_element *element;
 321   struct gdbarch *gdbarch = get_current_arch ();
 322   CORE_ADDR addr;
 323
 324   locator = tui_locator_win_info_ptr ();
 325   element = &locator->content[0]->which_element.locator;
 326
 327   if (element->addr == 0)
 328     {
 329       struct bound_minimal_symbol main_symbol;
 330
 331       /* Find address of the start of program.
 332          Note: this should be language specific.  */
 333       main_symbol = lookup_minimal_symbol ("main", NULL, NULL);
 334       if (main_symbol.minsym == 0)
 335         main_symbol = lookup_minimal_symbol ("MAIN", NULL, NULL);
 336       if (main_symbol.minsym == 0)
 337         main_symbol = lookup_minimal_symbol ("_start", NULL, NULL);
 338       if (main_symbol.minsym)
 339         addr = BMSYMBOL_VALUE_ADDRESS (main_symbol);
 340       else
 341         addr = 0;
 342     }
 343   else                          /* The target is executing.  */
 344     {
 345       gdbarch = element->gdbarch;
 346       addr = element->addr;
 347     }
 348
 349   *gdbarch_p = gdbarch;
 350   *addr_p = addr;
 351 }
 352
 353 /* Determine what the low address will be to display in the TUI's
 354    disassembly window.  This may or may not be the same as the low
 355    address input.  */
 356 CORE_ADDR
 357 tui_get_low_disassembly_address (struct gdbarch *gdbarch,
 358                                  CORE_ADDR low, CORE_ADDR pc)
 359 {
 360   int pos;
 361
 362   /* Determine where to start the disassembly so that the pc is about
 363      in the middle of the viewport.  */
 364   pos = tui_default_win_viewport_height (DISASSEM_WIN, DISASSEM_COMMAND) / 2;
 365   pc = tui_find_disassembly_address (gdbarch, pc, -pos);
 366
 367   if (pc < low)
 368     pc = low;
 369   return pc;
 370 }
 371
 372 /* Scroll the disassembly forward or backward vertically.  */
 373 void
 374 tui_disasm_window::do_scroll_vertical (int num_to_scroll)
 375 {
 376   if (content != NULL)
 377     {
 378       CORE_ADDR pc;
 379       struct tui_line_or_address val;
 380
 381       pc = content[0]->which_element.source.line_or_addr.u.addr;
 382       if (num_to_scroll >= 0)
 383         num_to_scroll++;
 384       else
 385         --num_to_scroll;
 386
 387       val.loa = LOA_ADDRESS;
 388       val.u.addr = tui_find_disassembly_address (gdbarch, pc, num_to_scroll);
 389       tui_update_source_window_as_is (this, gdbarch,
 390                                       NULL, val, FALSE);
 391     }
 392 }