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/* GDB routines for manipulating objfiles.

   Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,

   2002, 2003, 2004, 2007, 2008 Free Software Foundation, Inc.

   Contributed by Cygnus Support, using pieces from other GDB modules.

   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 3 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, see <http://www.gnu.org/licenses/>.  */

/* This file contains support routines for creating, manipulating, and

   destroying objfile structures. */

#include "defs.h"

#include "bfd.h"                /* Binary File Description */

#include "symtab.h"

#include "symfile.h"

#include "objfiles.h"

#include "gdb-stabs.h"

#include "target.h"

#include "bcache.h"

#include "mdebugread.h"

#include "expression.h"

#include "parser-defs.h"

#include "gdb_assert.h"

#include <sys/types.h>

#include "gdb_stat.h"

#include <fcntl.h>

#include "gdb_obstack.h"

#include "gdb_string.h"

#include "hashtab.h"

#include "breakpoint.h"

#include "block.h"

#include "dictionary.h"

#include "source.h"

#include "addrmap.h"

/* Prototypes for local functions */

static void objfile_alloc_data (struct objfile *objfile);

static void objfile_free_data (struct objfile *objfile);

/* Externally visible variables that are owned by this module.

   See declarations in objfile.h for more info. */

struct objfile *object_files;   /* Linked list of all objfiles */

struct objfile *current_objfile;        /* For symbol file being read in */

struct objfile *symfile_objfile;        /* Main symbol table loaded from */

struct objfile *rt_common_objfile;      /* For runtime common symbols */

/* Locate all mappable sections of a BFD file.

   objfile_p_char is a char * to get it through

   bfd_map_over_sections; we cast it back to its proper type.  */

#ifndef TARGET_KEEP_SECTION

#define TARGET_KEEP_SECTION(ASECT)      0

#endif

/* Called via bfd_map_over_sections to build up the section table that

   the objfile references.  The objfile contains pointers to the start

   of the table (objfile->sections) and to the first location after

   the end of the table (objfile->sections_end). */

static void

add_to_objfile_sections (struct bfd *abfd, struct bfd_section *asect,

                         void *objfile_p_char)

{

  struct objfile *objfile = (struct objfile *) objfile_p_char;

  struct obj_section section;

  flagword aflag;

  aflag = bfd_get_section_flags (abfd, asect);

  if (!(aflag & SEC_ALLOC) && !(TARGET_KEEP_SECTION (asect)))

    return;

  if (0 == bfd_section_size (abfd, asect))

    return;

  section.offset = 0;

  section.objfile = objfile;

  section.the_bfd_section = asect;

  section.ovly_mapped = 0;

  section.addr = bfd_section_vma (abfd, asect);

  section.endaddr = section.addr + bfd_section_size (abfd, asect);

  obstack_grow (&objfile->objfile_obstack, (char *) &section, sizeof (section));

  objfile->sections_end = (struct obj_section *) (((unsigned long) objfile->sections_end) + 1);

}

/* Builds a section table for OBJFILE.

   Returns 0 if OK, 1 on error (in which case bfd_error contains the

   error).

   Note that while we are building the table, which goes into the

   psymbol obstack, we hijack the sections_end pointer to instead hold

   a count of the number of sections.  When bfd_map_over_sections

   returns, this count is used to compute the pointer to the end of

   the sections table, which then overwrites the count.

   Also note that the OFFSET and OVLY_MAPPED in each table entry

   are initialized to zero.

   Also note that if anything else writes to the psymbol obstack while

   we are building the table, we're pretty much hosed. */

int

build_objfile_section_table (struct objfile *objfile)

{

  /* objfile->sections can be already set when reading a mapped symbol

     file.  I believe that we do need to rebuild the section table in

     this case (we rebuild other things derived from the bfd), but we

     can't free the old one (it's in the objfile_obstack).  So we just

     waste some memory.  */

  objfile->sections_end = 0;

  bfd_map_over_sections (objfile->obfd, add_to_objfile_sections, (char *) objfile);

  objfile->sections = (struct obj_section *)

    obstack_finish (&objfile->objfile_obstack);

  objfile->sections_end = objfile->sections + (unsigned long) objfile->sections_end;

  return (0);

}

/* Given a pointer to an initialized bfd (ABFD) and some flag bits

   allocate a new objfile struct, fill it in as best we can, link it

   into the list of all known objfiles, and return a pointer to the

   new objfile struct.

   The FLAGS word contains various bits (OBJF_*) that can be taken as

   requests for specific operations.  Other bits like OBJF_SHARED are

   simply copied through to the new objfile flags member. */

/* NOTE: carlton/2003-02-04: This function is called with args NULL, 0

   by jv-lang.c, to create an artificial objfile used to hold

   information about dynamically-loaded Java classes.  Unfortunately,

   that branch of this function doesn't get tested very frequently, so

   it's prone to breakage.  (E.g. at one time the name was set to NULL

   in that situation, which broke a loop over all names in the dynamic

   library loader.)  If you change this function, please try to leave

   things in a consistent state even if abfd is NULL.  */

struct objfile *

allocate_objfile (bfd *abfd, int flags)

{

  struct objfile *objfile = NULL;

  struct objfile *last_one = NULL;

  /* If we don't support mapped symbol files, didn't ask for the file to be

     mapped, or failed to open the mapped file for some reason, then revert

     back to an unmapped objfile. */

  if (objfile == NULL)

    {

      objfile = (struct objfile *) xmalloc (sizeof (struct objfile));

      memset (objfile, 0, sizeof (struct objfile));

      objfile->md = NULL;

      objfile->psymbol_cache = bcache_xmalloc ();

      objfile->macro_cache = bcache_xmalloc ();

      /* We could use obstack_specify_allocation here instead, but

         gdb_obstack.h specifies the alloc/dealloc functions.  */

      obstack_init (&objfile->objfile_obstack);

      terminate_minimal_symbol_table (objfile);

    }

  objfile_alloc_data (objfile);

  /* Update the per-objfile information that comes from the bfd, ensuring

     that any data that is reference is saved in the per-objfile data

     region. */

  objfile->obfd = abfd;

  if (objfile->name != NULL)

    {

      xfree (objfile->name);

    }

  if (abfd != NULL)

    {

      objfile->name = xstrdup (bfd_get_filename (abfd));

      objfile->mtime = bfd_get_mtime (abfd);

      /* Build section table.  */

      if (build_objfile_section_table (objfile))

        {

          error (_("Can't find the file sections in `%s': %s"),

                 objfile->name, bfd_errmsg (bfd_get_error ()));

        }

    }

  else

    {

      objfile->name = xstrdup ("<<anonymous objfile>>");

    }

  /* Initialize the section indexes for this objfile, so that we can

     later detect if they are used w/o being properly assigned to. */

  objfile->sect_index_text = -1;

  objfile->sect_index_data = -1;

  objfile->sect_index_bss = -1;

  objfile->sect_index_rodata = -1;

  /* We don't yet have a C++-specific namespace symtab.  */

  objfile->cp_namespace_symtab = NULL;

  /* Add this file onto the tail of the linked list of other such files. */

  objfile->next = NULL;

  if (object_files == NULL)

    object_files = objfile;

  else

    {

      for (last_one = object_files;

           last_one->next;

           last_one = last_one->next);

      last_one->next = objfile;

    }

  /* Save passed in flag bits. */

  objfile->flags |= flags;

  return (objfile);

}

/* Initialize entry point information for this objfile. */

void

init_entry_point_info (struct objfile *objfile)

{

  /* Save startup file's range of PC addresses to help blockframe.c

     decide where the bottom of the stack is.  */

  if (bfd_get_file_flags (objfile->obfd) & EXEC_P)

    {

      /* Executable file -- record its entry point so we'll recognize

         the startup file because it contains the entry point.  */

      objfile->ei.entry_point = bfd_get_start_address (objfile->obfd);

    }

  else

    {

      /* Examination of non-executable.o files.  Short-circuit this stuff.  */

      objfile->ei.entry_point = INVALID_ENTRY_POINT;

    }

}

/* Get current entry point address.  */

CORE_ADDR

entry_point_address (void)

{

  return symfile_objfile ? symfile_objfile->ei.entry_point : 0;

}

/* Create the terminating entry of OBJFILE's minimal symbol table.

   If OBJFILE->msymbols is zero, allocate a single entry from

   OBJFILE->objfile_obstack; otherwise, just initialize

   OBJFILE->msymbols[OBJFILE->minimal_symbol_count].  */

void

terminate_minimal_symbol_table (struct objfile *objfile)

{

  if (! objfile->msymbols)

    objfile->msymbols = ((struct minimal_symbol *)

                         obstack_alloc (&objfile->objfile_obstack,

                                        sizeof (objfile->msymbols[0])));

  {

    struct minimal_symbol *m

      = &objfile->msymbols[objfile->minimal_symbol_count];

    memset (m, 0, sizeof (*m));

    /* Don't rely on these enumeration values being 0's.  */

    MSYMBOL_TYPE (m) = mst_unknown;

    SYMBOL_INIT_LANGUAGE_SPECIFIC (m, language_unknown);

  }

}

/* Put one object file before a specified on in the global list.

   This can be used to make sure an object file is destroyed before

   another when using ALL_OBJFILES_SAFE to free all objfiles. */

void

put_objfile_before (struct objfile *objfile, struct objfile *before_this)

{

  struct objfile **objp;

  unlink_objfile (objfile);

  for (objp = &object_files; *objp != NULL; objp = &((*objp)->next))

    {

      if (*objp == before_this)

        {

          objfile->next = *objp;

          *objp = objfile;

          return;

        }

    }

  internal_error (__FILE__, __LINE__,

                  _("put_objfile_before: before objfile not in list"));

}

/* Put OBJFILE at the front of the list.  */

void

objfile_to_front (struct objfile *objfile)

{

  struct objfile **objp;

  for (objp = &object_files; *objp != NULL; objp = &((*objp)->next))

    {

      if (*objp == objfile)

        {

          /* Unhook it from where it is.  */

          *objp = objfile->next;

          /* Put it in the front.  */

          objfile->next = object_files;

          object_files = objfile;

          break;

        }

    }

}

/* Unlink OBJFILE from the list of known objfiles, if it is found in the

   list.

   It is not a bug, or error, to call this function if OBJFILE is not known

   to be in the current list.  This is done in the case of mapped objfiles,

   for example, just to ensure that the mapped objfile doesn't appear twice

   in the list.  Since the list is threaded, linking in a mapped objfile

   twice would create a circular list.

   If OBJFILE turns out to be in the list, we zap it's NEXT pointer after

   unlinking it, just to ensure that we have completely severed any linkages

   between the OBJFILE and the list. */

void

unlink_objfile (struct objfile *objfile)

{

  struct objfile **objpp;

  for (objpp = &object_files; *objpp != NULL; objpp = &((*objpp)->next))

    {

      if (*objpp == objfile)

        {

          *objpp = (*objpp)->next;

          objfile->next = NULL;

          return;

        }

    }

  internal_error (__FILE__, __LINE__,

                  _("unlink_objfile: objfile already unlinked"));

}

/* Destroy an objfile and all the symtabs and psymtabs under it.  Note

   that as much as possible is allocated on the objfile_obstack

   so that the memory can be efficiently freed.

   Things which we do NOT free because they are not in malloc'd memory

   or not in memory specific to the objfile include:

   objfile -> sf

   FIXME:  If the objfile is using reusable symbol information (via mmalloc),

   then we need to take into account the fact that more than one process

   may be using the symbol information at the same time (when mmalloc is

   extended to support cooperative locking).  When more than one process

   is using the mapped symbol info, we need to be more careful about when

   we free objects in the reusable area. */

void

free_objfile (struct objfile *objfile)

{

  if (objfile->separate_debug_objfile)

    {

      free_objfile (objfile->separate_debug_objfile);

    }

  if (objfile->separate_debug_objfile_backlink)

    {

      /* We freed the separate debug file, make sure the base objfile

         doesn't reference it.  */

      objfile->separate_debug_objfile_backlink->separate_debug_objfile = NULL;

    }

  /* Remove any references to this objfile in the global value

     lists.  */

  preserve_values (objfile);

  /* First do any symbol file specific actions required when we are

     finished with a particular symbol file.  Note that if the objfile

     is using reusable symbol information (via mmalloc) then each of

     these routines is responsible for doing the correct thing, either

     freeing things which are valid only during this particular gdb

     execution, or leaving them to be reused during the next one. */

  if (objfile->sf != NULL)

    {

      (*objfile->sf->sym_finish) (objfile);

    }

  /* We always close the bfd. */

  if (objfile->obfd != NULL)

    {

      char *name = bfd_get_filename (objfile->obfd);

      if (!bfd_close (objfile->obfd))

        warning (_("cannot close \"%s\": %s"),

                 name, bfd_errmsg (bfd_get_error ()));

      xfree (name);

    }

  /* Remove it from the chain of all objfiles. */

  unlink_objfile (objfile);

  /* If we are going to free the runtime common objfile, mark it

     as unallocated.  */

  if (objfile == rt_common_objfile)

    rt_common_objfile = NULL;

  /* Before the symbol table code was redone to make it easier to

     selectively load and remove information particular to a specific

     linkage unit, gdb used to do these things whenever the monolithic

     symbol table was blown away.  How much still needs to be done

     is unknown, but we play it safe for now and keep each action until

     it is shown to be no longer needed. */

  /* Not all our callers call clear_symtab_users (objfile_purge_solibs,

     for example), so we need to call this here.  */

  clear_pc_function_cache ();

  /* Clear globals which might have pointed into a removed objfile.

     FIXME: It's not clear which of these are supposed to persist

     between expressions and which ought to be reset each time.  */

  expression_context_block = NULL;

  innermost_block = NULL;

  /* Check to see if the current_source_symtab belongs to this objfile,

     and if so, call clear_current_source_symtab_and_line. */

  {

    struct symtab_and_line cursal = get_current_source_symtab_and_line ();

    struct symtab *s;

    ALL_OBJFILE_SYMTABS (objfile, s)

      {

        if (s == cursal.symtab)

          clear_current_source_symtab_and_line ();

      }

  }

  /* The last thing we do is free the objfile struct itself. */

  objfile_free_data (objfile);

  if (objfile->name != NULL)

    {

      xfree (objfile->name);

    }

  if (objfile->global_psymbols.list)

    xfree (objfile->global_psymbols.list);

  if (objfile->static_psymbols.list)

    xfree (objfile->static_psymbols.list);

  /* Free the obstacks for non-reusable objfiles */

  bcache_xfree (objfile->psymbol_cache);

  bcache_xfree (objfile->macro_cache);

  if (objfile->demangled_names_hash)

    htab_delete (objfile->demangled_names_hash);

  obstack_free (&objfile->objfile_obstack, 0);

  xfree (objfile);

  objfile = NULL;

}

static void

do_free_objfile_cleanup (void *obj)

{

  free_objfile (obj);

}

struct cleanup *

make_cleanup_free_objfile (struct objfile *obj)

{

  return make_cleanup (do_free_objfile_cleanup, obj);

}

/* Free all the object files at once and clean up their users.  */

void

free_all_objfiles (void)

{

  struct objfile *objfile, *temp;

  ALL_OBJFILES_SAFE (objfile, temp)

  {

    free_objfile (objfile);

  }

  clear_symtab_users ();

}

/* Relocate OBJFILE to NEW_OFFSETS.  There should be OBJFILE->NUM_SECTIONS

   entries in new_offsets.  */

void

objfile_relocate (struct objfile *objfile, struct section_offsets *new_offsets)

{

  struct section_offsets *delta =

    ((struct section_offsets *)

     alloca (SIZEOF_N_SECTION_OFFSETS (objfile->num_sections)));

  {

    int i;

    int something_changed = 0;

    for (i = 0; i < objfile->num_sections; ++i)

      {

        delta->offsets[i] =

          ANOFFSET (new_offsets, i) - ANOFFSET (objfile->section_offsets, i);

        if (ANOFFSET (delta, i) != 0)

          something_changed = 1;

      }

    if (!something_changed)

      return;

  }

  /* OK, get all the symtabs.  */

  {

    struct symtab *s;

    ALL_OBJFILE_SYMTABS (objfile, s)

    {

      struct linetable *l;

      struct blockvector *bv;

      int i;

      /* First the line table.  */

      l = LINETABLE (s);

      if (l)

        {

          for (i = 0; i < l->nitems; ++i)

            l->item[i].pc += ANOFFSET (delta, s->block_line_section);

        }

      /* Don't relocate a shared blockvector more than once.  */

      if (!s->primary)

        continue;

      bv = BLOCKVECTOR (s);

      for (i = 0; i < BLOCKVECTOR_NBLOCKS (bv); ++i)

        {

          struct block *b;

          struct symbol *sym;

          struct dict_iterator iter;

          b = BLOCKVECTOR_BLOCK (bv, i);

          BLOCK_START (b) += ANOFFSET (delta, s->block_line_section);

          BLOCK_END (b) += ANOFFSET (delta, s->block_line_section);

          if (BLOCKVECTOR_MAP (bv))

            addrmap_relocate (BLOCKVECTOR_MAP (bv),

                              ANOFFSET (delta, s->block_line_section));

          ALL_BLOCK_SYMBOLS (b, iter, sym)

            {

              fixup_symbol_section (sym, objfile);

              /* The RS6000 code from which this was taken skipped

                 any symbols in STRUCT_DOMAIN or UNDEF_DOMAIN.

                 But I'm leaving out that test, on the theory that

                 they can't possibly pass the tests below.  */

              if ((SYMBOL_CLASS (sym) == LOC_LABEL

                   || SYMBOL_CLASS (sym) == LOC_STATIC

                   || SYMBOL_CLASS (sym) == LOC_INDIRECT)

                  && SYMBOL_SECTION (sym) >= 0)

                {

                  SYMBOL_VALUE_ADDRESS (sym) +=

                    ANOFFSET (delta, SYMBOL_SECTION (sym));

                }

            }

        }

    }

  }

  {

    struct partial_symtab *p;

    ALL_OBJFILE_PSYMTABS (objfile, p)

    {

      p->textlow += ANOFFSET (delta, SECT_OFF_TEXT (objfile));

      p->texthigh += ANOFFSET (delta, SECT_OFF_TEXT (objfile));

    }

  }

  {

    struct partial_symbol **psym;

    for (psym = objfile->global_psymbols.list;

         psym < objfile->global_psymbols.next;

         psym++)

      {

        fixup_psymbol_section (*psym, objfile);

        if (SYMBOL_SECTION (*psym) >= 0)

          SYMBOL_VALUE_ADDRESS (*psym) += ANOFFSET (delta,

                                                    SYMBOL_SECTION (*psym));

      }

    for (psym = objfile->static_psymbols.list;

         psym < objfile->static_psymbols.next;

         psym++)

      {

        fixup_psymbol_section (*psym, objfile);

        if (SYMBOL_SECTION (*psym) >= 0)

          SYMBOL_VALUE_ADDRESS (*psym) += ANOFFSET (delta,

                                                    SYMBOL_SECTION (*psym));

      }

  }

  {

    struct minimal_symbol *msym;

    ALL_OBJFILE_MSYMBOLS (objfile, msym)

      if (SYMBOL_SECTION (msym) >= 0)

      SYMBOL_VALUE_ADDRESS (msym) += ANOFFSET (delta, SYMBOL_SECTION (msym));

  }

  /* Relocating different sections by different amounts may cause the symbols

     to be out of order.  */

  msymbols_sort (objfile);

  {

    int i;

    for (i = 0; i < objfile->num_sections; ++i)

      (objfile->section_offsets)->offsets[i] = ANOFFSET (new_offsets, i);

  }

  if (objfile->ei.entry_point != ~(CORE_ADDR) 0)

    {

      /* Relocate ei.entry_point with its section offset, use SECT_OFF_TEXT

         only as a fallback.  */

      struct obj_section *s;

      s = find_pc_section (objfile->ei.entry_point);

      if (s)

        objfile->ei.entry_point += ANOFFSET (delta, s->the_bfd_section->index);

      else

        objfile->ei.entry_point += ANOFFSET (delta, SECT_OFF_TEXT (objfile));

    }

  {

    struct obj_section *s;

    bfd *abfd;

    abfd = objfile->obfd;

    ALL_OBJFILE_OSECTIONS (objfile, s)

      {

        int idx = s->the_bfd_section->index;

        s->addr += ANOFFSET (delta, idx);

        s->endaddr += ANOFFSET (delta, idx);

      }

  }

  /* Relocate breakpoints as necessary, after things are relocated. */

  breakpoint_re_set ();

}

/* Many places in gdb want to test just to see if we have any partial

   symbols available.  This function returns zero if none are currently

   available, nonzero otherwise. */

int

have_partial_symbols (void)

{

  struct objfile *ofp;

  ALL_OBJFILES (ofp)

  {

    if (ofp->psymtabs != NULL)

      {

        return 1;

      }

  }

  return 0;

}

/* Many places in gdb want to test just to see if we have any full

   symbols available.  This function returns zero if none are currently

   available, nonzero otherwise. */

int

have_full_symbols (void)

{

  struct objfile *ofp;

  ALL_OBJFILES (ofp)

  {

    if (ofp->symtabs != NULL)

      {

        return 1;

      }

  }

  return 0;

}

/* This operations deletes all objfile entries that represent solibs that

   weren't explicitly loaded by the user, via e.g., the add-symbol-file

   command.

 */

void

objfile_purge_solibs (void)

{

  struct objfile *objf;

  struct objfile *temp;

  ALL_OBJFILES_SAFE (objf, temp)