gdb/tui/tui-disasm.c

   1 /* Disassembly display.
   2
   3    Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2007
   4    Free Software Foundation, Inc.
   5
   6    Contributed by Hewlett-Packard Company.
   7
   8    This file is part of GDB.
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  22
  23 #include "defs.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 "gdb_string.h"
  31 #include "tui/tui.h"
  32 #include "tui/tui-data.h"
  33 #include "tui/tui-win.h"
  34 #include "tui/tui-layout.h"
  35 #include "tui/tui-winsource.h"
  36 #include "tui/tui-stack.h"
  37 #include "tui/tui-file.h"
  38
  39 #include "gdb_curses.h"
  40
  41 struct tui_asm_line
  42 {
  43   CORE_ADDR addr;
  44   char *addr_string;
  45   char *insn;
  46 };
  47
  48 /* Function to set the disassembly window's content.
  49    Disassemble count lines starting at pc.
  50    Return address of the count'th instruction after pc.  */
  51 static CORE_ADDR
  52 tui_disassemble (struct tui_asm_line *asm_lines,
  53                  CORE_ADDR pc, int count)
  54 {
  55   struct ui_file *gdb_dis_out;
  56
  57   /* Now init the ui_file structure.  */
  58   gdb_dis_out = tui_sfileopen (256);
  59
  60   /* Now construct each line.  */
  61   for (; count > 0; count--, asm_lines++)
  62     {
  63       if (asm_lines->addr_string)
  64         xfree (asm_lines->addr_string);
  65       if (asm_lines->insn)
  66         xfree (asm_lines->insn);
  67
  68       print_address (pc, gdb_dis_out);
  69       asm_lines->addr = pc;
  70       asm_lines->addr_string = xstrdup (tui_file_get_strbuf (gdb_dis_out));
  71
  72       ui_file_rewind (gdb_dis_out);
  73
  74       pc = pc + gdb_print_insn (pc, gdb_dis_out, NULL);
  75
  76       asm_lines->insn = xstrdup (tui_file_get_strbuf (gdb_dis_out));
  77
  78       /* Reset the buffer to empty.  */
  79       ui_file_rewind (gdb_dis_out);
  80     }
  81   ui_file_delete (gdb_dis_out);
  82   return pc;
  83 }
  84
  85 /* Find the disassembly address that corresponds to FROM lines above
  86    or below the PC.  Variable sized instructions are taken into
  87    account by the algorithm.  */
  88 static CORE_ADDR
  89 tui_find_disassembly_address (CORE_ADDR pc, int from)
  90 {
  91   CORE_ADDR new_low;
  92   int max_lines;
  93   int i;
  94   struct tui_asm_line *asm_lines;
  95
  96   max_lines = (from > 0) ? from : - from;
  97   if (max_lines <= 1)
  98      return pc;
  99
 100   asm_lines = (struct tui_asm_line*) alloca (sizeof (struct tui_asm_line)
 101                                          * max_lines);
 102   memset (asm_lines, 0, sizeof (struct tui_asm_line) * max_lines);
 103
 104   new_low = pc;
 105   if (from > 0)
 106     {
 107       tui_disassemble (asm_lines, pc, max_lines);
 108       new_low = asm_lines[max_lines - 1].addr;
 109     }
 110   else
 111     {
 112       CORE_ADDR last_addr;
 113       int pos;
 114       struct minimal_symbol *msymbol;
 115
 116       /* Find backward an address which is a symbol and for which
 117          disassembling from that address will fill completely the
 118          window.  */
 119       pos = max_lines - 1;
 120       do {
 121          new_low -= 1 * max_lines;
 122          msymbol = lookup_minimal_symbol_by_pc_section (new_low, 0);
 123
 124          if (msymbol)
 125             new_low = SYMBOL_VALUE_ADDRESS (msymbol);
 126          else
 127             new_low += 1 * max_lines;
 128
 129          tui_disassemble (asm_lines, new_low, max_lines);
 130          last_addr = asm_lines[pos].addr;
 131       } while (last_addr > pc && msymbol);
 132
 133       /* Scan forward disassembling one instruction at a time until
 134          the last visible instruction of the window matches the pc.
 135          We keep the disassembled instructions in the 'lines' window
 136          and shift it downward (increasing its addresses).  */
 137       if (last_addr < pc)
 138         do
 139           {
 140             CORE_ADDR next_addr;
 141
 142             pos++;
 143             if (pos >= max_lines)
 144               pos = 0;
 145
 146             next_addr = tui_disassemble (&asm_lines[pos], last_addr, 1);
 147
 148             /* If there are some problems while disassembling exit.  */
 149             if (next_addr <= last_addr)
 150               break;
 151             last_addr = next_addr;
 152           } while (last_addr <= pc);
 153       pos++;
 154       if (pos >= max_lines)
 155          pos = 0;
 156       new_low = asm_lines[pos].addr;
 157     }
 158   for (i = 0; i < max_lines; i++)
 159     {
 160       xfree (asm_lines[i].addr_string);
 161       xfree (asm_lines[i].insn);
 162     }
 163   return new_low;
 164 }
 165
 166 /* Function to set the disassembly window's content.  */
 167 enum tui_status
 168 tui_set_disassem_content (CORE_ADDR pc)
 169 {
 170   enum tui_status ret = TUI_FAILURE;
 171   int i;
 172   int offset = TUI_DISASM_WIN->detail.source_info.horizontal_offset;
 173   int line_width, max_lines;
 174   CORE_ADDR cur_pc;
 175   struct tui_gen_win_info *locator = tui_locator_win_info_ptr ();
 176   int tab_len = tui_default_tab_len ();
 177   struct tui_asm_line *asm_lines;
 178   int insn_pos;
 179   int addr_size, max_size;
 180   char *line;
 181
 182   if (pc == 0)
 183     return TUI_FAILURE;
 184
 185   ret = tui_alloc_source_buffer (TUI_DISASM_WIN);
 186   if (ret != TUI_SUCCESS)
 187     return ret;
 188
 189   TUI_DISASM_WIN->detail.source_info.start_line_or_addr.loa = LOA_ADDRESS;
 190   TUI_DISASM_WIN->detail.source_info.start_line_or_addr.u.addr = pc;
 191   cur_pc = (CORE_ADDR)
 192     (((struct tui_win_element *) locator->content[0])->which_element.locator.addr);
 193
 194   max_lines = TUI_DISASM_WIN->generic.height - 2;       /* Account for
 195                                                            hilite.  */
 196
 197   /* Get temporary table that will hold all strings (addr & insn).  */
 198   asm_lines = (struct tui_asm_line*) alloca (sizeof (struct tui_asm_line)
 199                                          * max_lines);
 200   memset (asm_lines, 0, sizeof (struct tui_asm_line) * max_lines);
 201
 202   line_width = TUI_DISASM_WIN->generic.width - 1;
 203
 204   tui_disassemble (asm_lines, pc, max_lines);
 205
 206   /* See what is the maximum length of an address and of a line.  */
 207   addr_size = 0;
 208   max_size = 0;
 209   for (i = 0; i < max_lines; i++)
 210     {
 211       size_t len = strlen (asm_lines[i].addr_string);
 212       if (len > addr_size)
 213         addr_size = len;
 214
 215       len = strlen (asm_lines[i].insn) + tab_len;
 216       if (len > max_size)
 217         max_size = len;
 218     }
 219   max_size += addr_size + tab_len;
 220
 221   /* Allocate memory to create each line.  */
 222   line = (char*) alloca (max_size);
 223   insn_pos = (1 + (addr_size / tab_len)) * tab_len;
 224
 225   /* Now construct each line.  */
 226   for (i = 0; i < max_lines; i++)
 227     {
 228       struct tui_win_element *element;
 229       struct tui_source_element *src;
 230       int cur_len;
 231
 232       element = (struct tui_win_element *) TUI_DISASM_WIN->generic.content[i];
 233       src = &element->which_element.source;
 234       strcpy (line, asm_lines[i].addr_string);
 235       cur_len = strlen (line);
 236
 237       /* Add spaces to make the instructions start on the same
 238          column.  */
 239       while (cur_len < insn_pos)
 240         {
 241           strcat (line, " ");
 242           cur_len++;
 243         }
 244
 245       strcat (line, asm_lines[i].insn);
 246
 247       /* Now copy the line taking the offset into account.  */
 248       if (strlen (line) > offset)
 249         strcpy (src->line, &line[offset]);
 250       else
 251         src->line[0] = '\0';
 252
 253       src->line_or_addr.loa = LOA_ADDRESS;
 254       src->line_or_addr.u.addr = asm_lines[i].addr;
 255       src->is_exec_point = asm_lines[i].addr == cur_pc;
 256
 257       /* See whether there is a breakpoint installed.  */
 258       src->has_break = (!src->is_exec_point
 259                        && breakpoint_here_p (pc) != no_breakpoint_here);
 260
 261       xfree (asm_lines[i].addr_string);
 262       xfree (asm_lines[i].insn);
 263     }
 264   TUI_DISASM_WIN->generic.content_size = i;
 265   return TUI_SUCCESS;
 266 }
 267
 268
 269 /* Function to display the disassembly window with disassembled code.  */
 270 void
 271 tui_show_disassem (CORE_ADDR start_addr)
 272 {
 273   struct symtab *s = find_pc_symtab (start_addr);
 274   struct tui_win_info *win_with_focus = tui_win_with_focus ();
 275   struct tui_line_or_address val;
 276
 277   val.loa = LOA_ADDRESS;
 278   val.u.addr = start_addr;
 279   tui_add_win_to_layout (DISASSEM_WIN);
 280   tui_update_source_window (TUI_DISASM_WIN, s, val, FALSE);
 281
 282   /* If the focus was in the src win, put it in the asm win, if the
 283      source view isn't split.  */
 284   if (tui_current_layout () != SRC_DISASSEM_COMMAND
 285       && win_with_focus == TUI_SRC_WIN)
 286     tui_set_win_focus_to (TUI_DISASM_WIN);
 287
 288   return;
 289 }
 290
 291
 292 /* Function to display the disassembly window.  */
 293 void
 294 tui_show_disassem_and_update_source (CORE_ADDR start_addr)
 295 {
 296   struct symtab_and_line sal;
 297
 298   tui_show_disassem (start_addr);
 299   if (tui_current_layout () == SRC_DISASSEM_COMMAND)
 300     {
 301       struct tui_line_or_address val;
 302
 303       /* Update what is in the source window if it is displayed too,
 304          note that it follows what is in the disassembly window and
 305          visa-versa.  */
 306       sal = find_pc_line (start_addr, 0);
 307       val.loa = LOA_LINE;
 308       val.u.line_no = sal.line;
 309       tui_update_source_window (TUI_SRC_WIN, sal.symtab, val, TRUE);
 310       if (sal.symtab)
 311         {
 312           set_current_source_symtab_and_line (&sal);
 313           tui_update_locator_filename (sal.symtab->filename);
 314         }
 315       else
 316         tui_update_locator_filename ("?");
 317     }
 318
 319   return;
 320 }
 321
 322 CORE_ADDR
 323 tui_get_begin_asm_address (void)
 324 {
 325   struct tui_gen_win_info *locator;
 326   struct tui_locator_element *element;
 327   CORE_ADDR addr;
 328
 329   locator = tui_locator_win_info_ptr ();
 330   element = &((struct tui_win_element *) locator->content[0])->which_element.locator;
 331
 332   if (element->addr == 0)
 333     {
 334       struct minimal_symbol *main_symbol;
 335
 336       /* Find address of the start of program.
 337          Note: this should be language specific.  */
 338       main_symbol = lookup_minimal_symbol ("main", NULL, NULL);
 339       if (main_symbol == 0)
 340         main_symbol = lookup_minimal_symbol ("MAIN", NULL, NULL);
 341       if (main_symbol == 0)
 342         main_symbol = lookup_minimal_symbol ("_start", NULL, NULL);
 343       if (main_symbol)
 344         addr = SYMBOL_VALUE_ADDRESS (main_symbol);
 345       else
 346         addr = 0;
 347     }
 348   else                          /* The target is executing.  */
 349     addr = element->addr;
 350
 351   return addr;
 352 }
 353
 354 /* Determine what the low address will be to display in the TUI's
 355    disassembly window.  This may or may not be the same as the low
 356    address input.  */
 357 CORE_ADDR
 358 tui_get_low_disassembly_address (CORE_ADDR low,
 359                                  CORE_ADDR pc)
 360 {
 361   int pos;
 362
 363   /* Determine where to start the disassembly so that the pc is about
 364      in the middle of the viewport.  */
 365   pos = tui_default_win_viewport_height (DISASSEM_WIN, DISASSEM_COMMAND) / 2;
 366   pc = tui_find_disassembly_address (pc, -pos);
 367
 368   if (pc < low)
 369     pc = low;
 370   return pc;
 371 }
 372
 373 /* Scroll the disassembly forward or backward vertically.  */
 374 void
 375 tui_vertical_disassem_scroll (enum tui_scroll_direction scroll_direction,
 376                               int num_to_scroll)
 377 {
 378   if (TUI_DISASM_WIN->generic.content != NULL)
 379     {
 380       CORE_ADDR pc;
 381       tui_win_content content;
 382       struct symtab *s;
 383       struct tui_line_or_address val;
 384       int max_lines, dir;
 385       struct symtab_and_line cursal = get_current_source_symtab_and_line ();
 386
 387       content = (tui_win_content) TUI_DISASM_WIN->generic.content;
 388       if (cursal.symtab == (struct symtab *) NULL)
 389         s = find_pc_symtab (get_frame_pc (get_selected_frame (NULL)));
 390       else
 391         s = cursal.symtab;
 392
 393       /* Account for hilite.  */
 394       max_lines = TUI_DISASM_WIN->generic.height - 2;
 395       pc = content[0]->which_element.source.line_or_addr.u.addr;
 396       dir = (scroll_direction == FORWARD_SCROLL) ? max_lines : - max_lines;
 397
 398       val.loa = LOA_ADDRESS;
 399       val.u.addr = tui_find_disassembly_address (pc, dir);
 400       tui_update_source_window_as_is (TUI_DISASM_WIN, s, val, FALSE);
 401     }
 402 }