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->detail.source_info.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_DISASM_WIN->detail.source_info.gdbarch = gdbarch;
 188   TUI_DISASM_WIN->detail.source_info.start_line_or_addr.loa = LOA_ADDRESS;
 189   TUI_DISASM_WIN->detail.source_info.start_line_or_addr.u.addr = pc;
 190   cur_pc = locator->content[0]->which_element.locator.addr;
 191
 192   /* Window size, excluding highlight box.  */
 193   max_lines = TUI_DISASM_WIN->generic.height - 2;
 194   line_width = TUI_DISASM_WIN->generic.width - 2;
 195
 196   /* Get temporary table that will hold all strings (addr & insn).  */
 197   asm_lines = XALLOCAVEC (struct tui_asm_line, max_lines);
 198   memset (asm_lines, 0, sizeof (struct tui_asm_line) * max_lines);
 199
 200   tui_disassemble (gdbarch, asm_lines, pc, max_lines);
 201
 202   /* Determine maximum address- and instruction lengths.  */
 203   addr_size = 0;
 204   insn_size = 0;
 205   for (i = 0; i < max_lines; i++)
 206     {
 207       size_t len = strlen (asm_lines[i].addr_string);
 208
 209       if (len > addr_size)
 210         addr_size = len;
 211
 212       len = strlen (asm_lines[i].insn);
 213       if (len > insn_size)
 214         insn_size = len;
 215     }
 216
 217   /* Align instructions to the same column.  */
 218   insn_pos = (1 + (addr_size / tab_len)) * tab_len;
 219
 220   /* Allocate memory to create each line.  */
 221   line = (char*) alloca (insn_pos + insn_size + 1);
 222
 223   /* Now construct each line.  */
 224   for (i = 0; i < max_lines; i++)
 225     {
 226       struct tui_win_element *element;
 227       struct tui_source_element *src;
 228       int cur_len;
 229
 230       element = TUI_DISASM_WIN->generic.content[i];
 231       src = &element->which_element.source;
 232       strcpy (line, asm_lines[i].addr_string);
 233       cur_len = strlen (line);
 234       memset (line + cur_len, ' ', insn_pos - cur_len);
 235       strcpy (line + insn_pos, asm_lines[i].insn);
 236
 237       /* Now copy the line taking the offset into account.  */
 238       if (strlen (line) > offset)
 239         {
 240           strncpy (src->line, &line[offset], line_width);
 241           src->line[line_width] = '\0';
 242         }
 243       else
 244         src->line[0] = '\0';
 245
 246       src->line_or_addr.loa = LOA_ADDRESS;
 247       src->line_or_addr.u.addr = asm_lines[i].addr;
 248       src->is_exec_point = asm_lines[i].addr == cur_pc;
 249
 250       /* See whether there is a breakpoint installed.  */
 251       src->has_break = (!src->is_exec_point
 252                         && breakpoint_here_p (current_program_space->aspace,
 253                                               pc)
 254                         != no_breakpoint_here);
 255
 256       xfree (asm_lines[i].addr_string);
 257       xfree (asm_lines[i].insn);
 258     }
 259   TUI_DISASM_WIN->generic.content_size = i;
 260   return TUI_SUCCESS;
 261 }
 262
 263
 264 /* Function to display the disassembly window with disassembled code.  */
 265 void
 266 tui_show_disassem (struct gdbarch *gdbarch, CORE_ADDR start_addr)
 267 {
 268   struct symtab *s = find_pc_line_symtab (start_addr);
 269   struct tui_win_info *win_with_focus = tui_win_with_focus ();
 270   struct tui_line_or_address val;
 271
 272   val.loa = LOA_ADDRESS;
 273   val.u.addr = start_addr;
 274   tui_add_win_to_layout (DISASSEM_WIN);
 275   tui_update_source_window (TUI_DISASM_WIN, gdbarch, s, val, FALSE);
 276
 277   /* If the focus was in the src win, put it in the asm win, if the
 278      source view isn't split.  */
 279   if (tui_current_layout () != SRC_DISASSEM_COMMAND
 280       && win_with_focus == TUI_SRC_WIN)
 281     tui_set_win_focus_to (TUI_DISASM_WIN);
 282
 283   return;
 284 }
 285
 286
 287 /* Function to display the disassembly window.  */
 288 void
 289 tui_show_disassem_and_update_source (struct gdbarch *gdbarch,
 290                                      CORE_ADDR start_addr)
 291 {
 292   struct symtab_and_line sal;
 293
 294   tui_show_disassem (gdbarch, start_addr);
 295   if (tui_current_layout () == SRC_DISASSEM_COMMAND)
 296     {
 297       struct tui_line_or_address val;
 298
 299       /* Update what is in the source window if it is displayed too,
 300          note that it follows what is in the disassembly window and
 301          visa-versa.  */
 302       sal = find_pc_line (start_addr, 0);
 303       val.loa = LOA_LINE;
 304       val.u.line_no = sal.line;
 305       tui_update_source_window (TUI_SRC_WIN, gdbarch, sal.symtab, val, TRUE);
 306       if (sal.symtab)
 307         {
 308           set_current_source_symtab_and_line (sal);
 309           tui_update_locator_fullname (symtab_to_fullname (sal.symtab));
 310         }
 311       else
 312         tui_update_locator_fullname ("?");
 313     }
 314
 315   return;
 316 }
 317
 318 void
 319 tui_get_begin_asm_address (struct gdbarch **gdbarch_p, CORE_ADDR *addr_p)
 320 {
 321   struct tui_gen_win_info *locator;
 322   struct tui_locator_element *element;
 323   struct gdbarch *gdbarch = get_current_arch ();
 324   CORE_ADDR addr;
 325
 326   locator = tui_locator_win_info_ptr ();
 327   element = &locator->content[0]->which_element.locator;
 328
 329   if (element->addr == 0)
 330     {
 331       struct bound_minimal_symbol main_symbol;
 332
 333       /* Find address of the start of program.
 334          Note: this should be language specific.  */
 335       main_symbol = lookup_minimal_symbol ("main", NULL, NULL);
 336       if (main_symbol.minsym == 0)
 337         main_symbol = lookup_minimal_symbol ("MAIN", NULL, NULL);
 338       if (main_symbol.minsym == 0)
 339         main_symbol = lookup_minimal_symbol ("_start", NULL, NULL);
 340       if (main_symbol.minsym)
 341         addr = BMSYMBOL_VALUE_ADDRESS (main_symbol);
 342       else
 343         addr = 0;
 344     }
 345   else                          /* The target is executing.  */
 346     {
 347       gdbarch = element->gdbarch;
 348       addr = element->addr;
 349     }
 350
 351   *gdbarch_p = gdbarch;
 352   *addr_p = addr;
 353 }
 354
 355 /* Determine what the low address will be to display in the TUI's
 356    disassembly window.  This may or may not be the same as the low
 357    address input.  */
 358 CORE_ADDR
 359 tui_get_low_disassembly_address (struct gdbarch *gdbarch,
 360                                  CORE_ADDR low, CORE_ADDR pc)
 361 {
 362   int pos;
 363
 364   /* Determine where to start the disassembly so that the pc is about
 365      in the middle of the viewport.  */
 366   pos = tui_default_win_viewport_height (DISASSEM_WIN, DISASSEM_COMMAND) / 2;
 367   pc = tui_find_disassembly_address (gdbarch, pc, -pos);
 368
 369   if (pc < low)
 370     pc = low;
 371   return pc;
 372 }
 373
 374 /* Scroll the disassembly forward or backward vertically.  */
 375 void
 376 tui_vertical_disassem_scroll (enum tui_scroll_direction scroll_direction,
 377                               int num_to_scroll)
 378 {
 379   if (TUI_DISASM_WIN->generic.content != NULL)
 380     {
 381       struct gdbarch *gdbarch = TUI_DISASM_WIN->detail.source_info.gdbarch;
 382       CORE_ADDR pc;
 383       tui_win_content content;
 384       struct tui_line_or_address val;
 385       int dir;
 386
 387       content = TUI_DISASM_WIN->generic.content;
 388
 389       pc = content[0]->which_element.source.line_or_addr.u.addr;
 390       num_to_scroll++;
 391       dir = (scroll_direction == FORWARD_SCROLL)
 392         ? num_to_scroll : -num_to_scroll;
 393
 394       val.loa = LOA_ADDRESS;
 395       val.u.addr = tui_find_disassembly_address (gdbarch, pc, dir);
 396       tui_update_source_window_as_is (TUI_DISASM_WIN, gdbarch,
 397                                       NULL, val, FALSE);
 398     }
 399 }