gdb/disasm.c

   1 /* Disassemble support for GDB.
   2
   3    Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005
   4    Free Software Foundation, Inc.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  21    Boston, MA 02110-1301, USA.  */
  22
  23 #include "defs.h"
  24 #include "target.h"
  25 #include "value.h"
  26 #include "ui-out.h"
  27 #include "gdb_string.h"
  28 #include "disasm.h"
  29 #include "gdbcore.h"
  30 #include "dis-asm.h"
  31
  32 /* Disassemble functions.
  33    FIXME: We should get rid of all the duplicate code in gdb that does
  34    the same thing: disassemble_command() and the gdbtk variation. */
  35
  36 /* This Structure is used to store line number information.
  37    We need a different sort of line table from the normal one cuz we can't
  38    depend upon implicit line-end pc's for lines to do the
  39    reordering in this function.  */
  40
  41 struct dis_line_entry
  42 {
  43   int line;
  44   CORE_ADDR start_pc;
  45   CORE_ADDR end_pc;
  46 };
  47
  48 /* Like target_read_memory, but slightly different parameters.  */
  49 static int
  50 dis_asm_read_memory (bfd_vma memaddr, gdb_byte *myaddr, unsigned int len,
  51                      struct disassemble_info *info)
  52 {
  53   return target_read_memory (memaddr, myaddr, len);
  54 }
  55
  56 /* Like memory_error with slightly different parameters.  */
  57 static void
  58 dis_asm_memory_error (int status, bfd_vma memaddr,
  59                       struct disassemble_info *info)
  60 {
  61   memory_error (status, memaddr);
  62 }
  63
  64 /* Like print_address with slightly different parameters.  */
  65 static void
  66 dis_asm_print_address (bfd_vma addr, struct disassemble_info *info)
  67 {
  68   print_address (addr, info->stream);
  69 }
  70
  71 static int
  72 compare_lines (const void *mle1p, const void *mle2p)
  73 {
  74   struct dis_line_entry *mle1, *mle2;
  75   int val;
  76
  77   mle1 = (struct dis_line_entry *) mle1p;
  78   mle2 = (struct dis_line_entry *) mle2p;
  79
  80   val = mle1->line - mle2->line;
  81
  82   if (val != 0)
  83     return val;
  84
  85   return mle1->start_pc - mle2->start_pc;
  86 }
  87
  88 static int
  89 dump_insns (struct ui_out *uiout, struct disassemble_info * di,
  90             CORE_ADDR low, CORE_ADDR high,
  91             int how_many, struct ui_stream *stb)
  92 {
  93   int num_displayed = 0;
  94   CORE_ADDR pc;
  95
  96   /* parts of the symbolic representation of the address */
  97   int unmapped;
  98   int offset;
  99   int line;
 100   struct cleanup *ui_out_chain;
 101
 102   for (pc = low; pc < high;)
 103     {
 104       char *filename = NULL;
 105       char *name = NULL;
 106
 107       QUIT;
 108       if (how_many >= 0)
 109         {
 110           if (num_displayed >= how_many)
 111             break;
 112           else
 113             num_displayed++;
 114         }
 115       ui_out_chain = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
 116       ui_out_field_core_addr (uiout, "address", pc);
 117
 118       if (!build_address_symbolic (pc, 0, &name, &offset, &filename,
 119                                    &line, &unmapped))
 120         {
 121           /* We don't care now about line, filename and
 122              unmapped. But we might in the future. */
 123           ui_out_text (uiout, " <");
 124           ui_out_field_string (uiout, "func-name", name);
 125           ui_out_text (uiout, "+");
 126           ui_out_field_int (uiout, "offset", offset);
 127           ui_out_text (uiout, ">:\t");
 128         }
 129       else
 130         ui_out_text (uiout, ":\t");
 131
 132       if (filename != NULL)
 133         xfree (filename);
 134       if (name != NULL)
 135         xfree (name);
 136
 137       ui_file_rewind (stb->stream);
 138       pc += TARGET_PRINT_INSN (pc, di);
 139       ui_out_field_stream (uiout, "inst", stb);
 140       ui_file_rewind (stb->stream);
 141       do_cleanups (ui_out_chain);
 142       ui_out_text (uiout, "\n");
 143     }
 144   return num_displayed;
 145 }
 146
 147 /* The idea here is to present a source-O-centric view of a
 148    function to the user.  This means that things are presented
 149    in source order, with (possibly) out of order assembly
 150    immediately following.  */
 151 static void
 152 do_mixed_source_and_assembly (struct ui_out *uiout,
 153                               struct disassemble_info *di, int nlines,
 154                               struct linetable_entry *le,
 155                               CORE_ADDR low, CORE_ADDR high,
 156                               struct symtab *symtab,
 157                               int how_many, struct ui_stream *stb)
 158 {
 159   int newlines = 0;
 160   struct dis_line_entry *mle;
 161   struct symtab_and_line sal;
 162   int i;
 163   int out_of_order = 0;
 164   int next_line = 0;
 165   CORE_ADDR pc;
 166   int num_displayed = 0;
 167   struct cleanup *ui_out_chain;
 168   struct cleanup *ui_out_tuple_chain = make_cleanup (null_cleanup, 0);
 169   struct cleanup *ui_out_list_chain = make_cleanup (null_cleanup, 0);
 170
 171   mle = (struct dis_line_entry *) alloca (nlines
 172                                           * sizeof (struct dis_line_entry));
 173
 174   /* Copy linetable entries for this function into our data
 175      structure, creating end_pc's and setting out_of_order as
 176      appropriate.  */
 177
 178   /* First, skip all the preceding functions.  */
 179
 180   for (i = 0; i < nlines - 1 && le[i].pc < low; i++);
 181
 182   /* Now, copy all entries before the end of this function.  */
 183
 184   for (; i < nlines - 1 && le[i].pc < high; i++)
 185     {
 186       if (le[i].line == le[i + 1].line && le[i].pc == le[i + 1].pc)
 187         continue;               /* Ignore duplicates */
 188
 189       /* Skip any end-of-function markers.  */
 190       if (le[i].line == 0)
 191         continue;
 192
 193       mle[newlines].line = le[i].line;
 194       if (le[i].line > le[i + 1].line)
 195         out_of_order = 1;
 196       mle[newlines].start_pc = le[i].pc;
 197       mle[newlines].end_pc = le[i + 1].pc;
 198       newlines++;
 199     }
 200
 201   /* If we're on the last line, and it's part of the function,
 202      then we need to get the end pc in a special way.  */
 203
 204   if (i == nlines - 1 && le[i].pc < high)
 205     {
 206       mle[newlines].line = le[i].line;
 207       mle[newlines].start_pc = le[i].pc;
 208       sal = find_pc_line (le[i].pc, 0);
 209       mle[newlines].end_pc = sal.end;
 210       newlines++;
 211     }
 212
 213   /* Now, sort mle by line #s (and, then by addresses within
 214      lines). */
 215
 216   if (out_of_order)
 217     qsort (mle, newlines, sizeof (struct dis_line_entry), compare_lines);
 218
 219   /* Now, for each line entry, emit the specified lines (unless
 220      they have been emitted before), followed by the assembly code
 221      for that line.  */
 222
 223   ui_out_chain = make_cleanup_ui_out_list_begin_end (uiout, "asm_insns");
 224
 225   for (i = 0; i < newlines; i++)
 226     {
 227       /* Print out everything from next_line to the current line.  */
 228       if (mle[i].line >= next_line)
 229         {
 230           if (next_line != 0)
 231             {
 232               /* Just one line to print. */
 233               if (next_line == mle[i].line)
 234                 {
 235                   ui_out_tuple_chain
 236                     = make_cleanup_ui_out_tuple_begin_end (uiout,
 237                                                            "src_and_asm_line");
 238                   print_source_lines (symtab, next_line, mle[i].line + 1, 0);
 239                 }
 240               else
 241                 {
 242                   /* Several source lines w/o asm instructions associated. */
 243                   for (; next_line < mle[i].line; next_line++)
 244                     {
 245                       struct cleanup *ui_out_list_chain_line;
 246                       struct cleanup *ui_out_tuple_chain_line;
 247
 248                       ui_out_tuple_chain_line
 249                         = make_cleanup_ui_out_tuple_begin_end (uiout,
 250                                                                "src_and_asm_line");
 251                       print_source_lines (symtab, next_line, next_line + 1,
 252                                           0);
 253                       ui_out_list_chain_line
 254                         = make_cleanup_ui_out_list_begin_end (uiout,
 255                                                               "line_asm_insn");
 256                       do_cleanups (ui_out_list_chain_line);
 257                       do_cleanups (ui_out_tuple_chain_line);
 258                     }
 259                   /* Print the last line and leave list open for
 260                      asm instructions to be added. */
 261                   ui_out_tuple_chain
 262                     = make_cleanup_ui_out_tuple_begin_end (uiout,
 263                                                            "src_and_asm_line");
 264                   print_source_lines (symtab, next_line, mle[i].line + 1, 0);
 265                 }
 266             }
 267           else
 268             {
 269               ui_out_tuple_chain
 270                 = make_cleanup_ui_out_tuple_begin_end (uiout, "src_and_asm_line");
 271               print_source_lines (symtab, mle[i].line, mle[i].line + 1, 0);
 272             }
 273
 274           next_line = mle[i].line + 1;
 275           ui_out_list_chain
 276             = make_cleanup_ui_out_list_begin_end (uiout, "line_asm_insn");
 277         }
 278
 279       num_displayed += dump_insns (uiout, di, mle[i].start_pc, mle[i].end_pc,
 280                                    how_many, stb);
 281
 282       /* When we've reached the end of the mle array, or we've seen the last
 283          assembly range for this source line, close out the list/tuple.  */
 284       if (i == (newlines - 1) || mle[i + 1].line > mle[i].line)
 285         {
 286           do_cleanups (ui_out_list_chain);
 287           do_cleanups (ui_out_tuple_chain);
 288           ui_out_tuple_chain = make_cleanup (null_cleanup, 0);
 289           ui_out_list_chain = make_cleanup (null_cleanup, 0);
 290           ui_out_text (uiout, "\n");
 291         }
 292       if (how_many >= 0 && num_displayed >= how_many)
 293         break;
 294     }
 295   do_cleanups (ui_out_chain);
 296 }
 297
 298
 299 static void
 300 do_assembly_only (struct ui_out *uiout, struct disassemble_info * di,
 301                   CORE_ADDR low, CORE_ADDR high,
 302                   int how_many, struct ui_stream *stb)
 303 {
 304   int num_displayed = 0;
 305   struct cleanup *ui_out_chain;
 306
 307   ui_out_chain = make_cleanup_ui_out_list_begin_end (uiout, "asm_insns");
 308
 309   num_displayed = dump_insns (uiout, di, low, high, how_many, stb);
 310
 311   do_cleanups (ui_out_chain);
 312 }
 313
 314 /* Initialize the disassemble info struct ready for the specified
 315    stream.  */
 316
 317 static int ATTR_FORMAT (printf, 2, 3)
 318 fprintf_disasm (void *stream, const char *format, ...)
 319 {
 320   va_list args;
 321   va_start (args, format);
 322   vfprintf_filtered (stream, format, args);
 323   va_end (args);
 324   /* Something non -ve.  */
 325   return 0;
 326 }
 327
 328 static struct disassemble_info
 329 gdb_disassemble_info (struct gdbarch *gdbarch, struct ui_file *file)
 330 {
 331   struct disassemble_info di;
 332   init_disassemble_info (&di, file, fprintf_disasm);
 333   di.flavour = bfd_target_unknown_flavour;
 334   di.memory_error_func = dis_asm_memory_error;
 335   di.print_address_func = dis_asm_print_address;
 336   /* NOTE: cagney/2003-04-28: The original code, from the old Insight
 337      disassembler had a local optomization here.  By default it would
 338      access the executable file, instead of the target memory (there
 339      was a growing list of exceptions though).  Unfortunately, the
 340      heuristic was flawed.  Commands like "disassemble &variable"
 341      didn't work as they relied on the access going to the target.
 342      Further, it has been supperseeded by trust-read-only-sections
 343      (although that should be superseeded by target_trust..._p()).  */
 344   di.read_memory_func = dis_asm_read_memory;
 345   di.arch = gdbarch_bfd_arch_info (gdbarch)->arch;
 346   di.mach = gdbarch_bfd_arch_info (gdbarch)->mach;
 347   di.endian = gdbarch_byte_order (gdbarch);
 348   disassemble_init_for_target (&di);
 349   return di;
 350 }
 351
 352 void
 353 gdb_disassembly (struct ui_out *uiout,
 354                 char *file_string,
 355                 int line_num,
 356                 int mixed_source_and_assembly,
 357                 int how_many, CORE_ADDR low, CORE_ADDR high)
 358 {
 359   struct ui_stream *stb = ui_out_stream_new (uiout);
 360   struct cleanup *cleanups = make_cleanup_ui_out_stream_delete (stb);
 361   struct disassemble_info di = gdb_disassemble_info (current_gdbarch, stb->stream);
 362   /* To collect the instruction outputted from opcodes. */
 363   struct symtab *symtab = NULL;
 364   struct linetable_entry *le = NULL;
 365   int nlines = -1;
 366
 367   /* Assume symtab is valid for whole PC range */
 368   symtab = find_pc_symtab (low);
 369
 370   if (symtab != NULL && symtab->linetable != NULL)
 371     {
 372       /* Convert the linetable to a bunch of my_line_entry's.  */
 373       le = symtab->linetable->item;
 374       nlines = symtab->linetable->nitems;
 375     }
 376
 377   if (!mixed_source_and_assembly || nlines <= 0
 378       || symtab == NULL || symtab->linetable == NULL)
 379     do_assembly_only (uiout, &di, low, high, how_many, stb);
 380
 381   else if (mixed_source_and_assembly)
 382     do_mixed_source_and_assembly (uiout, &di, nlines, le, low,
 383                                   high, symtab, how_many, stb);
 384
 385   do_cleanups (cleanups);
 386   gdb_flush (gdb_stdout);
 387 }
 388
 389 /* Print the instruction at address MEMADDR in debugged memory,
 390    on STREAM.  Returns length of the instruction, in bytes.  */
 391
 392 int
 393 gdb_print_insn (CORE_ADDR memaddr, struct ui_file *stream)
 394 {
 395   struct disassemble_info di = gdb_disassemble_info (current_gdbarch, stream);
 396   return TARGET_PRINT_INSN (memaddr, &di);
 397 }