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 2 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, write to the Free Software
  22    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  23    Boston, MA 02110-1301, USA.  */
  24
  25 #include "defs.h"
  26 #include "symtab.h"
  27 #include "breakpoint.h"
  28 #include "frame.h"
  29 #include "value.h"
  30 #include "source.h"
  31 #include "disasm.h"
  32 #include "gdb_string.h"
  33 #include "tui/tui.h"
  34 #include "tui/tui-data.h"
  35 #include "tui/tui-win.h"
  36 #include "tui/tui-layout.h"
  37 #include "tui/tui-winsource.h"
  38 #include "tui/tui-stack.h"
  39 #include "tui/tui-file.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 tui_asm_line *asm_lines, CORE_ADDR pc, int count)
  55 {
  56   struct ui_file *gdb_dis_out;
  57
  58   /* now init the ui_file structure */
  59   gdb_dis_out = tui_sfileopen (256);
  60
  61   /* Now construct each line */
  62   for (; count > 0; count--, asm_lines++)
  63     {
  64       if (asm_lines->addr_string)
  65         xfree (asm_lines->addr_string);
  66       if (asm_lines->insn)
  67         xfree (asm_lines->insn);
  68
  69       print_address (pc, gdb_dis_out);
  70       asm_lines->addr = pc;
  71       asm_lines->addr_string = xstrdup (tui_file_get_strbuf (gdb_dis_out));
  72
  73       ui_file_rewind (gdb_dis_out);
  74
  75       pc = pc + gdb_print_insn (pc, gdb_dis_out, NULL);
  76
  77       asm_lines->insn = xstrdup (tui_file_get_strbuf (gdb_dis_out));
  78
  79       /* reset the buffer to empty */
  80       ui_file_rewind (gdb_dis_out);
  81     }
  82   ui_file_delete (gdb_dis_out);
  83   return pc;
  84 }
  85
  86 /* Find the disassembly address that corresponds to FROM lines
  87    above or below the PC.  Variable sized instructions are taken
  88    into account by the algorithm.  */
  89 static CORE_ADDR
  90 tui_find_disassembly_address (CORE_ADDR pc, int from)
  91 {
  92   CORE_ADDR new_low;
  93   int max_lines;
  94   int i;
  95   struct tui_asm_line *asm_lines;
  96
  97   max_lines = (from > 0) ? from : - from;
  98   if (max_lines <= 1)
  99      return pc;
 100
 101   asm_lines = (struct tui_asm_line*) alloca (sizeof (struct tui_asm_line)
 102                                          * max_lines);
 103   memset (asm_lines, 0, sizeof (struct tui_asm_line) * max_lines);
 104
 105   new_low = pc;
 106   if (from > 0)
 107     {
 108       tui_disassemble (asm_lines, pc, max_lines);
 109       new_low = asm_lines[max_lines - 1].addr;
 110     }
 111   else
 112     {
 113       CORE_ADDR last_addr;
 114       int pos;
 115       struct minimal_symbol *msymbol;
 116
 117       /* Find backward an address which is a symbol
 118          and for which disassembling from that address will fill
 119          completely the window.  */
 120       pos = max_lines - 1;
 121       do {
 122          new_low -= 1 * max_lines;
 123          msymbol = lookup_minimal_symbol_by_pc_section (new_low, 0);
 124
 125          if (msymbol)
 126             new_low = SYMBOL_VALUE_ADDRESS (msymbol);
 127          else
 128             new_low += 1 * max_lines;
 129
 130          tui_disassemble (asm_lines, new_low, max_lines);
 131          last_addr = asm_lines[pos].addr;
 132       } while (last_addr > pc && msymbol);
 133
 134       /* Scan forward disassembling one instruction at a time
 135          until the last visible instruction of the window
 136          matches the pc.  We keep the disassembled instructions
 137          in the 'lines' window and shift it downward (increasing
 138          its addresses).  */
 139       if (last_addr < pc)
 140         do
 141           {
 142             CORE_ADDR next_addr;
 143
 144             pos++;
 145             if (pos >= max_lines)
 146               pos = 0;
 147
 148             next_addr = tui_disassemble (&asm_lines[pos], last_addr, 1);
 149
 150             /* If there are some problems while disassembling exit.  */
 151             if (next_addr <= last_addr)
 152               break;
 153             last_addr = next_addr;
 154           } while (last_addr <= pc);
 155       pos++;
 156       if (pos >= max_lines)
 157          pos = 0;
 158       new_low = asm_lines[pos].addr;
 159     }
 160   for (i = 0; i < max_lines; i++)
 161     {
 162       xfree (asm_lines[i].addr_string);
 163       xfree (asm_lines[i].insn);
 164     }
 165   return new_low;
 166 }
 167
 168 /* Function to set the disassembly window's content.  */
 169 enum tui_status
 170 tui_set_disassem_content (CORE_ADDR pc)
 171 {
 172   enum tui_status ret = TUI_FAILURE;
 173   int i;
 174   int offset = TUI_DISASM_WIN->detail.source_info.horizontal_offset;
 175   int line_width, max_lines;
 176   CORE_ADDR cur_pc;
 177   struct tui_gen_win_info *locator = tui_locator_win_info_ptr ();
 178   int tab_len = tui_default_tab_len ();
 179   struct tui_asm_line *asm_lines;
 180   int insn_pos;
 181   int addr_size, max_size;
 182   char *line;
 183
 184   if (pc == 0)
 185     return TUI_FAILURE;
 186
 187   ret = tui_alloc_source_buffer (TUI_DISASM_WIN);
 188   if (ret != TUI_SUCCESS)
 189     return ret;
 190
 191   TUI_DISASM_WIN->detail.source_info.start_line_or_addr.loa = LOA_ADDRESS;
 192   TUI_DISASM_WIN->detail.source_info.start_line_or_addr.u.addr = pc;
 193   cur_pc = (CORE_ADDR)
 194     (((struct tui_win_element *) locator->content[0])->which_element.locator.addr);
 195
 196   max_lines = TUI_DISASM_WIN->generic.height - 2;       /* account for hilite */
 197
 198   /* Get temporary table that will hold all strings (addr & insn).  */
 199   asm_lines = (struct tui_asm_line*) alloca (sizeof (struct tui_asm_line)
 200                                          * max_lines);
 201   memset (asm_lines, 0, sizeof (struct tui_asm_line) * max_lines);
 202
 203   line_width = TUI_DISASM_WIN->generic.width - 1;
 204
 205   tui_disassemble (asm_lines, pc, max_lines);
 206
 207   /* See what is the maximum length of an address and of a line.  */
 208   addr_size = 0;
 209   max_size = 0;
 210   for (i = 0; i < max_lines; i++)
 211     {
 212       size_t len = strlen (asm_lines[i].addr_string);
 213       if (len > addr_size)
 214         addr_size = len;
 215
 216       len = strlen (asm_lines[i].insn) + tab_len;
 217       if (len > max_size)
 218         max_size = len;
 219     }
 220   max_size += addr_size + tab_len;
 221
 222   /* Allocate memory to create each line.  */
 223   line = (char*) alloca (max_size);
 224   insn_pos = (1 + (addr_size / tab_len)) * tab_len;
 225
 226   /* Now construct each line */
 227   for (i = 0; i < max_lines; i++)
 228     {
 229       struct tui_win_element *element;
 230       struct tui_source_element *src;
 231       int cur_len;
 232
 233       element = (struct tui_win_element *) TUI_DISASM_WIN->generic.content[i];
 234       src = &element->which_element.source;
 235       strcpy (line, asm_lines[i].addr_string);
 236       cur_len = strlen (line);
 237
 238       /* Add spaces to make the instructions start on the same 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    */
 285   if (tui_current_layout () != SRC_DISASSEM_COMMAND && 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       /*
 304          ** Update what is in the source window if it is displayed too,
 305          ** note that it follows what is in the disassembly window and visa-versa
 306        */
 307       sal = find_pc_line (start_addr, 0);
 308       val.loa = LOA_LINE;
 309       val.u.line_no = sal.line;
 310       tui_update_source_window (TUI_SRC_WIN, sal.symtab, val, TRUE);
 311       if (sal.symtab)
 312         {
 313           set_current_source_symtab_and_line (&sal);
 314           tui_update_locator_filename (sal.symtab->filename);
 315         }
 316       else
 317         tui_update_locator_filename ("?");
 318     }
 319
 320   return;
 321 }
 322
 323 CORE_ADDR
 324 tui_get_begin_asm_address (void)
 325 {
 326   struct tui_gen_win_info *locator;
 327   struct tui_locator_element *element;
 328   CORE_ADDR addr;
 329
 330   locator = tui_locator_win_info_ptr ();
 331   element = &((struct tui_win_element *) locator->content[0])->which_element.locator;
 332
 333   if (element->addr == 0)
 334     {
 335       struct minimal_symbol *main_symbol;
 336
 337       /* Find address of the start of program.
 338          Note: this should be language specific.  */
 339       main_symbol = lookup_minimal_symbol ("main", NULL, NULL);
 340       if (main_symbol == 0)
 341         main_symbol = lookup_minimal_symbol ("MAIN", NULL, NULL);
 342       if (main_symbol == 0)
 343         main_symbol = lookup_minimal_symbol ("_start", NULL, NULL);
 344       if (main_symbol)
 345         addr = SYMBOL_VALUE_ADDRESS (main_symbol);
 346       else
 347         addr = 0;
 348     }
 349   else                          /* the target is executing */
 350     addr = element->addr;
 351
 352   return 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
 357    low address input.  */
 358 CORE_ADDR
 359 tui_get_low_disassembly_address (CORE_ADDR low, CORE_ADDR pc)
 360 {
 361   int pos;
 362
 363   /* Determine where to start the disassembly so that the pc is about in the
 364      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 }