machoread.c   [plain text]

/* Mac OS X support for GDB, the GNU debugger.
   Copyright 1997, 1998, 1999, 2000, 2001, 2002
   Free Software Foundation, Inc.

   Contributed by Apple Computer, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include "defs.h"
#include "symtab.h"
#include "gdbtypes.h"
#include "breakpoint.h"
#include "bfd.h"
#include "symfile.h"
#include "objfiles.h"
#include "buildsym.h"
#include "obstack.h"
#include "gdb-stabs.h"
#include "stabsread.h"
#include "gdbcmd.h"
#include "completer.h"

#include "mach-o.h"

#include <string.h>

static int mach_o_process_exports_flag = 1;

struct macho_symfile_info {
  asymbol **syms;
  long nsyms;
};

static int macho_read_indirect_symbols (bfd *abfd, 
                             struct bfd_mach_o_dysymtab_command *dysymtab, 
                             struct bfd_mach_o_symtab_command *symtab, 
                             struct objfile *objfile, 
                             char *symbol_name);

static void
macho_new_init (objfile)
     struct objfile *objfile;
{
}

static void
macho_symfile_init (objfile)
     struct objfile *objfile;
{
  objfile->sym_stab_info = 
    xmmalloc (objfile->md, sizeof (struct dbx_symfile_info));

  memset ((PTR) objfile->sym_stab_info, 0, sizeof (struct dbx_symfile_info));

  objfile->sym_private = 
    xmmalloc (objfile->md,sizeof (struct macho_symfile_info));

  memset (objfile->sym_private, 0, sizeof (struct macho_symfile_info));

  objfile->flags |= OBJF_REORDERED;
  init_entry_point_info (objfile);
}

static void
macho_symfile_read (objfile, mainline)
     struct objfile *objfile;
     int mainline;
{
  bfd *abfd = objfile->obfd;

  struct bfd_mach_o_load_command *gsymtab, *gdysymtab;

  struct bfd_mach_o_symtab_command *symtab = NULL;
  struct bfd_mach_o_dysymtab_command *dysymtab = NULL;
  struct bfd_mach_o_section *section = NULL;

  int ret;

  CHECK_FATAL (objfile != NULL);
  CHECK_FATAL (abfd != NULL);
  CHECK_FATAL (abfd->filename != NULL);

  init_minimal_symbol_collection ();
  make_cleanup_discard_minimal_symbols ();
    
  stabsect_build_psymtabs (objfile, mainline,
			   "LC_SYMTAB.stabs", "LC_SYMTAB.stabstr",
			   "LC_SEGMENT.__TEXT.__text",
			   "LC_SEGMENT.__DATA.__data",
			   NULL);

  if (mach_o_process_exports_flag) {

    ret = bfd_mach_o_lookup_command (abfd, BFD_MACH_O_LC_SYMTAB, &gsymtab);
    if (ret != 1) {
      /* warning ("Error fetching LC_SYMTAB load command from object file \"%s\"", 
                  abfd->filename); */
      install_minimal_symbols (objfile);
      return;
    }

    ret = bfd_mach_o_lookup_command (abfd, BFD_MACH_O_LC_DYSYMTAB, &gdysymtab);
    if (ret != 1) {
      /* warning ("Error fetching LC_DYSYMTAB load command from object file \"%s\"", 
                  abfd->filename); */
      install_minimal_symbols (objfile);
      return;
    }

    CHECK_FATAL (gsymtab->type == BFD_MACH_O_LC_SYMTAB);
    CHECK_FATAL (gdysymtab->type == BFD_MACH_O_LC_DYSYMTAB);

    symtab = &gsymtab->command.symtab;
    dysymtab = &gdysymtab->command.dysymtab;
    
    CHECK_FATAL (DBX_STRINGTAB (objfile) != NULL);
    if (symtab->strtab == NULL) {
      symtab->strtab = DBX_STRINGTAB (objfile);
    }

    if (symtab->strtab == NULL) {
      ret = bfd_mach_o_scan_read_symtab_strtab (abfd, symtab);
      if (ret != 0) { 
	warning ("Unable to read symbol table for \"%s\": %s", 
		 abfd->filename, bfd_errmsg (bfd_get_error ()));
	install_minimal_symbols (objfile);
	return;
      }
    }

    /* FIXME: Technically, we should iterate over all the sections and get 
       all the ones of type SYMBOL_STUB. */
    if (!macho_read_indirect_symbols (abfd, dysymtab, symtab, 
                                      objfile, 
                                      "LC_SEGMENT.__TEXT.__picsymbol_stub"))
      {
        install_minimal_symbols (objfile);
        return;
      }
                                 
    if (!macho_read_indirect_symbols (abfd, dysymtab, symtab, 
                                      objfile, 
                                      "LC_SEGMENT.__TEXT.__symbol_stub"))
      {
        install_minimal_symbols (objfile);
        return;
      }
                                 
    
  }

  install_minimal_symbols (objfile);
}

int
macho_read_indirect_symbols (bfd *abfd, 
                             struct bfd_mach_o_dysymtab_command *dysymtab, 
                             struct bfd_mach_o_symtab_command *symtab, 
                             struct objfile *objfile,
                             char *section_name)
{

  unsigned long i, nsyms, ret;
  asymbol sym;
  asection *bfdsec = NULL;
  struct bfd_mach_o_section *section = NULL;
  struct bfd_mach_o_load_command *lcommand = NULL;

  bfdsec = bfd_get_section_by_name (abfd, section_name);
  if (bfdsec == NULL) {
    /* warning ("Error fetching __TEXT.__picsymbol_stub section from object file."); */
    return 0;
  }

  ret = bfd_mach_o_lookup_section (abfd, bfdsec, &lcommand, &section);
  if ((ret != 1) || (lcommand != NULL)) {
    /* warning ("Error fetching __TEXT.__picsymbol_stub section from object file."); */
    return 0;
  }

  CHECK_FATAL (section != NULL);
    
  nsyms = section->size / section->reserved2;

  for (i = 0; i < nsyms; i++) {
  
    unsigned long cursym = section->reserved1 + i;
    CORE_ADDR stubaddr = section->addr + (i * section->reserved2);
    const char *sname = NULL;
    char nname[4096];

    if (cursym >= dysymtab->nindirectsyms) {
      warning ("Indirect symbol entry out of range in \"%s\" (%lu >= %lu)",
                abfd->filename, cursym, (unsigned long) dysymtab->nindirectsyms);
      return 0;
    } 
    ret = bfd_mach_o_scan_read_dysymtab_symbol (abfd, dysymtab, symtab, &sym, cursym);
    if (ret != 0) {
      return 0;
    }

    sname = sym.name;
    CHECK_FATAL (sname != NULL);
    if (sname[0] == bfd_get_symbol_leading_char (abfd)) {
      sname++;
    }

    CHECK_FATAL ((strlen (sname) + sizeof ("__dyld_stub_") + 1) < 4096);
    sprintf (nname, "dyld_stub_%s", sname);

    stubaddr += ANOFFSET (objfile->section_offsets, SECT_OFF_TEXT (objfile));
    prim_record_minimal_symbol_and_info
      (nname, stubaddr, mst_solib_trampoline, NULL, SECT_OFF_TEXT (objfile), bfd_get_section (&sym), objfile);
  }
  return 1;
}

static void
macho_symfile_finish (objfile)
     struct objfile *objfile;
{
}

static void
macho_symfile_offsets (objfile, addrs)
     struct objfile *objfile;
     struct section_addr_info *addrs;
{
  unsigned int i;

  objfile->num_sections = SECT_OFF_MAX;
  objfile->section_offsets = (struct section_offsets *)
    obstack_alloc (&objfile->psymbol_obstack, SIZEOF_SECTION_OFFSETS);
  memset (objfile->section_offsets, 0, SIZEOF_SECTION_OFFSETS);

  for (i = 0; i < objfile->sections_end - objfile->sections; i++) {
    objfile->sections[i].addr += addrs->other[0].addr;
    objfile->sections[i].endaddr += addrs->other[0].addr;
  }

  for (i = 0; i < MAX_SECTIONS; i++) {
    objfile->section_offsets->offsets[i] = (long) addrs->other[0].addr;
  }

  objfile->sect_index_text = 0;
  objfile->sect_index_data = 0;
  objfile->sect_index_bss = 0;
  objfile->sect_index_rodata = 0;
}

static struct sym_fns macho_sym_fns =
{
  bfd_target_mach_o_flavour,

  macho_new_init,		/* sym_new_init: init anything gbl to entire symtab */
  macho_symfile_init,		/* sym_init: read initial info, setup for sym_read() */
  macho_symfile_read,		/* sym_read: read a symbol file into symtab */
  macho_symfile_finish,		/* sym_finish: finished with file, cleanup */
  macho_symfile_offsets,	/* sym_offsets:  xlate external to internal form */
  NULL				/* next: pointer to next struct sym_fns */
};

void
_initialize_machoread ()
{
  struct cmd_list_element *cmd;

  add_symtab_fns (&macho_sym_fns);

  cmd = add_set_cmd ("mach-o-process-exports", class_obscure, var_boolean, 
		     (char *) &mach_o_process_exports_flag,
		     "Set if GDB should process indirect function stub symbols from object files.",
		     &setlist);
  add_show_from_set (cmd, &showlist);		
}