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,
  55                  CORE_ADDR pc, int count)
  56 {
  57   struct ui_file *gdb_dis_out;
  58
  59   /* Now init the ui_file structure.  */
  60   gdb_dis_out = tui_sfileopen (256);
  61
  62   /* Now construct each line.  */
  63   for (; count > 0; count--, asm_lines++)
  64     {
  65       if (asm_lines->addr_string)
  66         xfree (asm_lines->addr_string);
  67       if (asm_lines->insn)
  68         xfree (asm_lines->insn);
  69
  70       print_address (pc, gdb_dis_out);
  71       asm_lines->addr = pc;
  72       asm_lines->addr_string = xstrdup (tui_file_get_strbuf (gdb_dis_out));
  73
  74       ui_file_rewind (gdb_dis_out);
  75
  76       pc = pc + gdb_print_insn (pc, gdb_dis_out, NULL);
  77
  78       asm_lines->insn = xstrdup (tui_file_get_strbuf (gdb_dis_out));
  79
  80       /* Reset the buffer to empty.  */
  81       ui_file_rewind (gdb_dis_out);
  82     }
  83   ui_file_delete (gdb_dis_out);
  84   return pc;
  85 }
  86
  87 /* Find the disassembly address that corresponds to FROM lines above
  88    or below the PC.  Variable sized instructions are taken into
  89    account by the algorithm.  */
  90 static CORE_ADDR
  91 tui_find_disassembly_address (CORE_ADDR pc, int from)
  92 {
  93   CORE_ADDR new_low;
  94   int max_lines;
  95   int i;
  96   struct tui_asm_line *asm_lines;
  97
  98   max_lines = (from > 0) ? from : - from;
  99   if (max_lines <= 1)
 100      return pc;
 101
 102   asm_lines = (struct tui_asm_line*) alloca (sizeof (struct tui_asm_line)
 103                                          * max_lines);
 104   memset (asm_lines, 0, sizeof (struct tui_asm_line) * max_lines);
 105
 106   new_low = pc;
 107   if (from > 0)
 108     {
 109       tui_disassemble (asm_lines, pc, max_lines);
 110       new_low = asm_lines[max_lines - 1].addr;
 111     }
 112   else
 113     {
 114       CORE_ADDR last_addr;
 115       int pos;
 116       struct minimal_symbol *msymbol;
 117
 118       /* Find backward an address which is a symbol and for which
 119          disassembling from that address will fill completely the
 120          window.  */
 121       pos = max_lines - 1;
 122       do {
 123          new_low -= 1 * max_lines;
 124          msymbol = lookup_minimal_symbol_by_pc_section (new_low, 0);
 125
 126          if (msymbol)
 127             new_low = SYMBOL_VALUE_ADDRESS (msymbol);
 128          else
 129             new_low += 1 * max_lines;
 130
 131          tui_disassemble (asm_lines, new_low, max_lines);
 132          last_addr = asm_lines[pos].addr;
 133       } while (last_addr > pc && msymbol);
 134
 135       /* Scan forward disassembling one instruction at a time until
 136          the last visible instruction of the window matches the pc.
 137          We keep the disassembled instructions in the 'lines' window
 138          and shift it downward (increasing 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
 197                                                            hilite.  */
 198
 199   /* Get temporary table that will hold all strings (addr & insn).  */
 200   asm_lines = (struct tui_asm_line*) alloca (sizeof (struct tui_asm_line)
 201                                          * max_lines);
 202   memset (asm_lines, 0, sizeof (struct tui_asm_line) * max_lines);
 203
 204   line_width = TUI_DISASM_WIN->generic.width - 1;
 205
 206   tui_disassemble (asm_lines, pc, max_lines);
 207
 208   /* See what is the maximum length of an address and of a line.  */
 209   addr_size = 0;
 210   max_size = 0;
 211   for (i = 0; i < max_lines; i++)
 212     {
 213       size_t len = strlen (asm_lines[i].addr_string);
 214       if (len > addr_size)
 215         addr_size = len;
 216
 217       len = strlen (asm_lines[i].insn) + tab_len;
 218       if (len > max_size)
 219         max_size = len;
 220     }
 221   max_size += addr_size + tab_len;
 222
 223   /* Allocate memory to create each line.  */
 224   line = (char*) alloca (max_size);
 225   insn_pos = (1 + (addr_size / tab_len)) * tab_len;
 226
 227   /* Now construct each line.  */
 228   for (i = 0; i < max_lines; i++)
 229     {
 230       struct tui_win_element *element;
 231       struct tui_source_element *src;
 232       int cur_len;
 233
 234       element = (struct tui_win_element *) TUI_DISASM_WIN->generic.content[i];
 235       src = &element->which_element.source;
 236       strcpy (line, asm_lines[i].addr_string);
 237       cur_len = strlen (line);
 238
 239       /* Add spaces to make the instructions start on the same
 240          column.  */
 241       while (cur_len < insn_pos)
 242         {
 243           strcat (line, " ");
 244           cur_len++;
 245         }
 246
 247       strcat (line, asm_lines[i].insn);
 248
 249       /* Now copy the line taking the offset into account.  */
 250       if (strlen (line) > offset)
 251         strcpy (src->line, &line[offset]);
 252       else
 253         src->line[0] = '\0';
 254
 255       src->line_or_addr.loa = LOA_ADDRESS;
 256       src->line_or_addr.u.addr = asm_lines[i].addr;
 257       src->is_exec_point = asm_lines[i].addr == cur_pc;
 258
 259       /* See whether there is a breakpoint installed.  */
 260       src->has_break = (!src->is_exec_point
 261                        && breakpoint_here_p (pc) != no_breakpoint_here);
 262
 263       xfree (asm_lines[i].addr_string);
 264       xfree (asm_lines[i].insn);
 265     }
 266   TUI_DISASM_WIN->generic.content_size = i;
 267   return TUI_SUCCESS;
 268 }
 269
 270
 271 /* Function to display the disassembly window with disassembled code.  */
 272 void
 273 tui_show_disassem (CORE_ADDR start_addr)
 274 {
 275   struct symtab *s = find_pc_symtab (start_addr);
 276   struct tui_win_info *win_with_focus = tui_win_with_focus ();
 277   struct tui_line_or_address val;
 278
 279   val.loa = LOA_ADDRESS;
 280   val.u.addr = start_addr;
 281   tui_add_win_to_layout (DISASSEM_WIN);
 282   tui_update_source_window (TUI_DISASM_WIN, s, val, FALSE);
 283
 284   /* If the focus was in the src win, put it in the asm win, if the
 285      source view isn't split.  */
 286   if (tui_current_layout () != SRC_DISASSEM_COMMAND
 287       && win_with_focus == TUI_SRC_WIN)
 288     tui_set_win_focus_to (TUI_DISASM_WIN);
 289
 290   return;
 291 }
 292
 293
 294 /* Function to display the disassembly window.  */
 295 void
 296 tui_show_disassem_and_update_source (CORE_ADDR start_addr)
 297 {
 298   struct symtab_and_line sal;
 299
 300   tui_show_disassem (start_addr);
 301   if (tui_current_layout () == SRC_DISASSEM_COMMAND)
 302     {
 303       struct tui_line_or_address val;
 304
 305       /* Update what is in the source window if it is displayed too,
 306          note that it follows what is in the disassembly window and
 307          visa-versa.  */
 308       sal = find_pc_line (start_addr, 0);
 309       val.loa = LOA_LINE;
 310       val.u.line_no = sal.line;
 311       tui_update_source_window (TUI_SRC_WIN, sal.symtab, val, TRUE);
 312       if (sal.symtab)
 313         {
 314           set_current_source_symtab_and_line (&sal);
 315           tui_update_locator_filename (sal.symtab->filename);
 316         }
 317       else
 318         tui_update_locator_filename ("?");
 319     }
 320
 321   return;
 322 }
 323
 324 CORE_ADDR
 325 tui_get_begin_asm_address (void)
 326 {
 327   struct tui_gen_win_info *locator;
 328   struct tui_locator_element *element;
 329   CORE_ADDR addr;
 330
 331   locator = tui_locator_win_info_ptr ();
 332   element = &((struct tui_win_element *) locator->content[0])->which_element.locator;
 333
 334   if (element->addr == 0)
 335     {
 336       struct minimal_symbol *main_symbol;
 337
 338       /* Find address of the start of program.
 339          Note: this should be language specific.  */
 340       main_symbol = lookup_minimal_symbol ("main", NULL, NULL);
 341       if (main_symbol == 0)
 342         main_symbol = lookup_minimal_symbol ("MAIN", NULL, NULL);
 343       if (main_symbol == 0)
 344         main_symbol = lookup_minimal_symbol ("_start", NULL, NULL);
 345       if (main_symbol)
 346         addr = SYMBOL_VALUE_ADDRESS (main_symbol);
 347       else
 348         addr = 0;
 349     }
 350   else                          /* The target is executing.  */
 351     addr = element->addr;
 352
 353   return addr;
 354 }
 355
 356 /* Determine what the low address will be to display in the TUI's
 357    disassembly window.  This may or may not be the same as the low
 358    address input.  */
 359 CORE_ADDR
 360 tui_get_low_disassembly_address (CORE_ADDR low,
 361                                  CORE_ADDR pc)
 362 {
 363   int pos;
 364
 365   /* Determine where to start the disassembly so that the pc is about
 366      in the middle of the viewport.  */
 367   pos = tui_default_win_viewport_height (DISASSEM_WIN, DISASSEM_COMMAND) / 2;
 368   pc = tui_find_disassembly_address (pc, -pos);
 369
 370   if (pc < low)
 371     pc = low;
 372   return pc;
 373 }
 374
 375 /* Scroll the disassembly forward or backward vertically.  */
 376 void
 377 tui_vertical_disassem_scroll (enum tui_scroll_direction scroll_direction,
 378                               int num_to_scroll)
 379 {
 380   if (TUI_DISASM_WIN->generic.content != NULL)
 381     {
 382       CORE_ADDR pc;
 383       tui_win_content content;
 384       struct symtab *s;
 385       struct tui_line_or_address val;
 386       int max_lines, dir;
 387       struct symtab_and_line cursal = get_current_source_symtab_and_line ();
 388
 389       content = (tui_win_content) TUI_DISASM_WIN->generic.content;
 390       if (cursal.symtab == (struct symtab *) NULL)
 391         s = find_pc_symtab (get_frame_pc (get_selected_frame (NULL)));
 392       else
 393         s = cursal.symtab;
 394
 395       /* Account for hilite.  */
 396       max_lines = TUI_DISASM_WIN->generic.height - 2;
 397       pc = content[0]->which_element.source.line_or_addr.u.addr;
 398       dir = (scroll_direction == FORWARD_SCROLL) ? max_lines : - max_lines;
 399
 400       val.loa = LOA_ADDRESS;
 401       val.u.addr = tui_find_disassembly_address (pc, dir);
 402       tui_update_source_window_as_is (TUI_DISASM_WIN, s, val, FALSE);
 403     }
 404 }