gdb/disasm.c

   1 /* Disassemble support for GDB.
   2
   3    Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009
   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 3 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, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include "defs.h"
  22 #include "target.h"
  23 #include "value.h"
  24 #include "ui-out.h"
  25 #include "gdb_string.h"
  26 #include "disasm.h"
  27 #include "gdbcore.h"
  28 #include "dis-asm.h"
  29
  30 /* Disassemble functions.
  31    FIXME: We should get rid of all the duplicate code in gdb that does
  32    the same thing: disassemble_command() and the gdbtk variation. */
  33
  34 /* This Structure is used to store line number information.
  35    We need a different sort of line table from the normal one cuz we can't
  36    depend upon implicit line-end pc's for lines to do the
  37    reordering in this function.  */
  38
  39 struct dis_line_entry
  40 {
  41   int line;
  42   CORE_ADDR start_pc;
  43   CORE_ADDR end_pc;
  44 };
  45
  46 /* Like target_read_memory, but slightly different parameters.  */
  47 static int
  48 dis_asm_read_memory (bfd_vma memaddr, gdb_byte *myaddr, unsigned int len,
  49                      struct disassemble_info *info)
  50 {
  51   return target_read_memory (memaddr, myaddr, len);
  52 }
  53
  54 /* Like memory_error with slightly different parameters.  */
  55 static void
  56 dis_asm_memory_error (int status, bfd_vma memaddr,
  57                       struct disassemble_info *info)
  58 {
  59   memory_error (status, memaddr);
  60 }
  61
  62 /* Like print_address with slightly different parameters.  */
  63 static void
  64 dis_asm_print_address (bfd_vma addr, struct disassemble_info *info)
  65 {
  66   struct gdbarch *gdbarch = info->application_data;
  67   print_address (gdbarch, addr, info->stream);
  68 }
  69
  70 static int
  71 compare_lines (const void *mle1p, const void *mle2p)
  72 {
  73   struct dis_line_entry *mle1, *mle2;
  74   int val;
  75
  76   mle1 = (struct dis_line_entry *) mle1p;
  77   mle2 = (struct dis_line_entry *) mle2p;
  78
  79   val = mle1->line - mle2->line;
  80
  81   if (val != 0)
  82     return val;
  83
  84   return mle1->start_pc - mle2->start_pc;
  85 }
  86
  87 static int
  88 dump_insns (struct gdbarch *gdbarch, struct ui_out *uiout,
  89             struct disassemble_info * di,
  90             CORE_ADDR low, CORE_ADDR high,
  91             int how_many, int flags, 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_text (uiout, pc_prefix (pc));
 117       ui_out_field_core_addr (uiout, "address", gdbarch, pc);
 118
 119       if (!build_address_symbolic (pc, 0, &name, &offset, &filename,
 120                                    &line, &unmapped))
 121         {
 122           /* We don't care now about line, filename and
 123              unmapped. But we might in the future. */
 124           ui_out_text (uiout, " <");
 125           ui_out_field_string (uiout, "func-name", name);
 126           ui_out_text (uiout, "+");
 127           ui_out_field_int (uiout, "offset", offset);
 128           ui_out_text (uiout, ">:\t");
 129         }
 130       else
 131         ui_out_text (uiout, ":\t");
 132
 133       if (filename != NULL)
 134         xfree (filename);
 135       if (name != NULL)
 136         xfree (name);
 137
 138       ui_file_rewind (stb->stream);
 139       if (flags & DISASSEMBLY_RAW_INSN)
 140         {
 141           CORE_ADDR old_pc = pc;
 142           bfd_byte data;
 143           int status;
 144           pc += gdbarch_print_insn (gdbarch, pc, di);
 145           for (;old_pc < pc; old_pc++)
 146             {
 147               status = (*di->read_memory_func) (old_pc, &data, 1, di);
 148               if (status != 0)
 149                 (*di->memory_error_func) (status, old_pc, di);
 150               ui_out_message (uiout, 0, " %02x", (unsigned)data);
 151             }
 152           ui_out_text (uiout, "\t");
 153         }
 154       else
 155         pc += gdbarch_print_insn (gdbarch, pc, di);
 156       ui_out_field_stream (uiout, "inst", stb);
 157       ui_file_rewind (stb->stream);
 158       do_cleanups (ui_out_chain);
 159       ui_out_text (uiout, "\n");
 160     }
 161   return num_displayed;
 162 }
 163
 164 /* The idea here is to present a source-O-centric view of a
 165    function to the user.  This means that things are presented
 166    in source order, with (possibly) out of order assembly
 167    immediately following.  */
 168 static void
 169 do_mixed_source_and_assembly (struct gdbarch *gdbarch, struct ui_out *uiout,
 170                               struct disassemble_info *di, int nlines,
 171                               struct linetable_entry *le,
 172                               CORE_ADDR low, CORE_ADDR high,
 173                               struct symtab *symtab,
 174                               int how_many, int flags, struct ui_stream *stb)
 175 {
 176   int newlines = 0;
 177   struct dis_line_entry *mle;
 178   struct symtab_and_line sal;
 179   int i;
 180   int out_of_order = 0;
 181   int next_line = 0;
 182   CORE_ADDR pc;
 183   int num_displayed = 0;
 184   struct cleanup *ui_out_chain;
 185   struct cleanup *ui_out_tuple_chain = make_cleanup (null_cleanup, 0);
 186   struct cleanup *ui_out_list_chain = make_cleanup (null_cleanup, 0);
 187
 188   mle = (struct dis_line_entry *) alloca (nlines
 189                                           * sizeof (struct dis_line_entry));
 190
 191   /* Copy linetable entries for this function into our data
 192      structure, creating end_pc's and setting out_of_order as
 193      appropriate.  */
 194
 195   /* First, skip all the preceding functions.  */
 196
 197   for (i = 0; i < nlines - 1 && le[i].pc < low; i++);
 198
 199   /* Now, copy all entries before the end of this function.  */
 200
 201   for (; i < nlines - 1 && le[i].pc < high; i++)
 202     {
 203       if (le[i].line == le[i + 1].line && le[i].pc == le[i + 1].pc)
 204         continue;               /* Ignore duplicates */
 205
 206       /* Skip any end-of-function markers.  */
 207       if (le[i].line == 0)
 208         continue;
 209
 210       mle[newlines].line = le[i].line;
 211       if (le[i].line > le[i + 1].line)
 212         out_of_order = 1;
 213       mle[newlines].start_pc = le[i].pc;
 214       mle[newlines].end_pc = le[i + 1].pc;
 215       newlines++;
 216     }
 217
 218   /* If we're on the last line, and it's part of the function,
 219      then we need to get the end pc in a special way.  */
 220
 221   if (i == nlines - 1 && le[i].pc < high)
 222     {
 223       mle[newlines].line = le[i].line;
 224       mle[newlines].start_pc = le[i].pc;
 225       sal = find_pc_line (le[i].pc, 0);
 226       mle[newlines].end_pc = sal.end;
 227       newlines++;
 228     }
 229
 230   /* Now, sort mle by line #s (and, then by addresses within
 231      lines). */
 232
 233   if (out_of_order)
 234     qsort (mle, newlines, sizeof (struct dis_line_entry), compare_lines);
 235
 236   /* Now, for each line entry, emit the specified lines (unless
 237      they have been emitted before), followed by the assembly code
 238      for that line.  */
 239
 240   ui_out_chain = make_cleanup_ui_out_list_begin_end (uiout, "asm_insns");
 241
 242   for (i = 0; i < newlines; i++)
 243     {
 244       /* Print out everything from next_line to the current line.  */
 245       if (mle[i].line >= next_line)
 246         {
 247           if (next_line != 0)
 248             {
 249               /* Just one line to print. */
 250               if (next_line == mle[i].line)
 251                 {
 252                   ui_out_tuple_chain
 253                     = make_cleanup_ui_out_tuple_begin_end (uiout,
 254                                                            "src_and_asm_line");
 255                   print_source_lines (symtab, next_line, mle[i].line + 1, 0);
 256                 }
 257               else
 258                 {
 259                   /* Several source lines w/o asm instructions associated. */
 260                   for (; next_line < mle[i].line; next_line++)
 261                     {
 262                       struct cleanup *ui_out_list_chain_line;
 263                       struct cleanup *ui_out_tuple_chain_line;
 264
 265                       ui_out_tuple_chain_line
 266                         = make_cleanup_ui_out_tuple_begin_end (uiout,
 267                                                                "src_and_asm_line");
 268                       print_source_lines (symtab, next_line, next_line + 1,
 269                                           0);
 270                       ui_out_list_chain_line
 271                         = make_cleanup_ui_out_list_begin_end (uiout,
 272                                                               "line_asm_insn");
 273                       do_cleanups (ui_out_list_chain_line);
 274                       do_cleanups (ui_out_tuple_chain_line);
 275                     }
 276                   /* Print the last line and leave list open for
 277                      asm instructions to be added. */
 278                   ui_out_tuple_chain
 279                     = make_cleanup_ui_out_tuple_begin_end (uiout,
 280                                                            "src_and_asm_line");
 281                   print_source_lines (symtab, next_line, mle[i].line + 1, 0);
 282                 }
 283             }
 284           else
 285             {
 286               ui_out_tuple_chain
 287                 = make_cleanup_ui_out_tuple_begin_end (uiout, "src_and_asm_line");
 288               print_source_lines (symtab, mle[i].line, mle[i].line + 1, 0);
 289             }
 290
 291           next_line = mle[i].line + 1;
 292           ui_out_list_chain
 293             = make_cleanup_ui_out_list_begin_end (uiout, "line_asm_insn");
 294         }
 295
 296       num_displayed += dump_insns (gdbarch, uiout, di,
 297                                    mle[i].start_pc, mle[i].end_pc,
 298                                    how_many, flags, stb);
 299
 300       /* When we've reached the end of the mle array, or we've seen the last
 301          assembly range for this source line, close out the list/tuple.  */
 302       if (i == (newlines - 1) || mle[i + 1].line > mle[i].line)
 303         {
 304           do_cleanups (ui_out_list_chain);
 305           do_cleanups (ui_out_tuple_chain);
 306           ui_out_tuple_chain = make_cleanup (null_cleanup, 0);
 307           ui_out_list_chain = make_cleanup (null_cleanup, 0);
 308           ui_out_text (uiout, "\n");
 309         }
 310       if (how_many >= 0 && num_displayed >= how_many)
 311         break;
 312     }
 313   do_cleanups (ui_out_chain);
 314 }
 315
 316
 317 static void
 318 do_assembly_only (struct gdbarch *gdbarch, struct ui_out *uiout,
 319                   struct disassemble_info * di,
 320                   CORE_ADDR low, CORE_ADDR high,
 321                   int how_many, int flags, struct ui_stream *stb)
 322 {
 323   int num_displayed = 0;
 324   struct cleanup *ui_out_chain;
 325
 326   ui_out_chain = make_cleanup_ui_out_list_begin_end (uiout, "asm_insns");
 327
 328   num_displayed = dump_insns (gdbarch, uiout, di, low, high, how_many,
 329                               flags, stb);
 330
 331   do_cleanups (ui_out_chain);
 332 }
 333
 334 /* Initialize the disassemble info struct ready for the specified
 335    stream.  */
 336
 337 static int ATTR_FORMAT (printf, 2, 3)
 338 fprintf_disasm (void *stream, const char *format, ...)
 339 {
 340   va_list args;
 341   va_start (args, format);
 342   vfprintf_filtered (stream, format, args);
 343   va_end (args);
 344   /* Something non -ve.  */
 345   return 0;
 346 }
 347
 348 static struct disassemble_info
 349 gdb_disassemble_info (struct gdbarch *gdbarch, struct ui_file *file)
 350 {
 351   struct disassemble_info di;
 352   init_disassemble_info (&di, file, fprintf_disasm);
 353   di.flavour = bfd_target_unknown_flavour;
 354   di.memory_error_func = dis_asm_memory_error;
 355   di.print_address_func = dis_asm_print_address;
 356   /* NOTE: cagney/2003-04-28: The original code, from the old Insight
 357      disassembler had a local optomization here.  By default it would
 358      access the executable file, instead of the target memory (there
 359      was a growing list of exceptions though).  Unfortunately, the
 360      heuristic was flawed.  Commands like "disassemble &variable"
 361      didn't work as they relied on the access going to the target.
 362      Further, it has been supperseeded by trust-read-only-sections
 363      (although that should be superseeded by target_trust..._p()).  */
 364   di.read_memory_func = dis_asm_read_memory;
 365   di.arch = gdbarch_bfd_arch_info (gdbarch)->arch;
 366   di.mach = gdbarch_bfd_arch_info (gdbarch)->mach;
 367   di.endian = gdbarch_byte_order (gdbarch);
 368   di.endian_code = gdbarch_byte_order_for_code (gdbarch);
 369   di.application_data = gdbarch;
 370   disassemble_init_for_target (&di);
 371   return di;
 372 }
 373
 374 void
 375 gdb_disassembly (struct gdbarch *gdbarch, struct ui_out *uiout,
 376                 char *file_string,
 377                 int flags,
 378                 int how_many, CORE_ADDR low, CORE_ADDR high)
 379 {
 380   struct ui_stream *stb = ui_out_stream_new (uiout);
 381   struct cleanup *cleanups = make_cleanup_ui_out_stream_delete (stb);
 382   struct disassemble_info di = gdb_disassemble_info (gdbarch, stb->stream);
 383   /* To collect the instruction outputted from opcodes. */
 384   struct symtab *symtab = NULL;
 385   struct linetable_entry *le = NULL;
 386   int nlines = -1;
 387
 388   /* Assume symtab is valid for whole PC range */
 389   symtab = find_pc_symtab (low);
 390
 391   if (symtab != NULL && symtab->linetable != NULL)
 392     {
 393       /* Convert the linetable to a bunch of my_line_entry's.  */
 394       le = symtab->linetable->item;
 395       nlines = symtab->linetable->nitems;
 396     }
 397
 398   if (!(flags & DISASSEMBLY_SOURCE) || nlines <= 0
 399       || symtab == NULL || symtab->linetable == NULL)
 400     do_assembly_only (gdbarch, uiout, &di, low, high, how_many, flags, stb);
 401
 402   else if (flags & DISASSEMBLY_SOURCE)
 403     do_mixed_source_and_assembly (gdbarch, uiout, &di, nlines, le, low,
 404                                   high, symtab, how_many, flags, stb);
 405
 406   do_cleanups (cleanups);
 407   gdb_flush (gdb_stdout);
 408 }
 409
 410 /* Print the instruction at address MEMADDR in debugged memory,
 411    on STREAM.  Returns the length of the instruction, in bytes,
 412    and, if requested, the number of branch delay slot instructions.  */
 413
 414 int
 415 gdb_print_insn (struct gdbarch *gdbarch, CORE_ADDR memaddr,
 416                 struct ui_file *stream, int *branch_delay_insns)
 417 {
 418   struct disassemble_info di;
 419   int length;
 420
 421   di = gdb_disassemble_info (gdbarch, stream);
 422   length = gdbarch_print_insn (gdbarch, memaddr, &di);
 423   if (branch_delay_insns)
 424     {
 425       if (di.insn_info_valid)
 426         *branch_delay_insns = di.branch_delay_insns;
 427       else
 428         *branch_delay_insns = 0;
 429     }
 430   return length;
 431 }