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/* GDB routines for manipulating objfiles.

   Copyright 1992, 1993, 1994, 1995 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 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.  */

/* 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 <sys/types.h>

#include "gdb_stat.h"

#include <fcntl.h>

#include "obstack.h"

#include "gdb_string.h"

#include "breakpoint.h"

/* Prototypes for local functions */

#if defined(USE_MMALLOC) && defined(HAVE_MMAP)

static int

open_existing_mapped_file PARAMS ((char *, long, int));

static int

open_mapped_file PARAMS ((char *filename, long mtime, int flags));

static PTR

  map_to_file PARAMS ((int));

#endif /* defined(USE_MMALLOC) && defined(HAVE_MMAP) */

static void

add_to_objfile_sections PARAMS ((bfd *, sec_ptr, PTR));

/* 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 */

int mapped_symbol_files;        /* Try to use mapped symbol files */

/* 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 (abfd, asect, objfile_p_char)

     bfd *abfd;

     sec_ptr asect;

     PTR 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->psymbol_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 (objfile)

     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 psymbol_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->psymbol_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, like trying to open a mapped

   version of the objfile (OBJF_MAPPED).  Other bits like

   OBJF_SHARED are simply copied through to the new objfile flags

   member. */

struct objfile *

allocate_objfile (abfd, flags)

     bfd *abfd;

     int flags;

{

  struct objfile *objfile = NULL;

  struct objfile *last_one = NULL;

  if (mapped_symbol_files)

    flags |= OBJF_MAPPED;

#if defined(USE_MMALLOC) && defined(HAVE_MMAP)

  if (abfd != NULL)

    {

      /* If we can support mapped symbol files, try to open/reopen the

         mapped file that corresponds to the file from which we wish to

         read symbols.  If the objfile is to be mapped, we must malloc

         the structure itself using the mmap version, and arrange that

         all memory allocation for the objfile uses the mmap routines.

         If we are reusing an existing mapped file, from which we get

         our objfile pointer, we have to make sure that we update the

         pointers to the alloc/free functions in the obstack, in case

         these functions have moved within the current gdb.  */

      int fd;

      fd = open_mapped_file (bfd_get_filename (abfd), bfd_get_mtime (abfd),

                             flags);

      if (fd >= 0)

        {

          PTR md;

          if ((md = map_to_file (fd)) == NULL)

            {

              close (fd);

            }

          else if ((objfile = (struct objfile *) mmalloc_getkey (md, 0)) != NULL)

            {

              /* Update memory corruption handler function addresses. */

              init_malloc (md);

              objfile->md = md;

              objfile->mmfd = fd;

              /* Update pointers to functions to *our* copies */

              obstack_chunkfun (&objfile->psymbol_cache.cache, xmmalloc);

              obstack_freefun (&objfile->psymbol_cache.cache, mfree);

              obstack_chunkfun (&objfile->psymbol_obstack, xmmalloc);

              obstack_freefun (&objfile->psymbol_obstack, mfree);

              obstack_chunkfun (&objfile->symbol_obstack, xmmalloc);

              obstack_freefun (&objfile->symbol_obstack, mfree);

              obstack_chunkfun (&objfile->type_obstack, xmmalloc);

              obstack_freefun (&objfile->type_obstack, mfree);

              /* If already in objfile list, unlink it. */

              unlink_objfile (objfile);

              /* Forget things specific to a particular gdb, may have changed. */

              objfile->sf = NULL;

            }

          else

            {

              /* Set up to detect internal memory corruption.  MUST be

                 done before the first malloc.  See comments in

                 init_malloc() and mmcheck().  */

              init_malloc (md);

              objfile = (struct objfile *)

                xmmalloc (md, sizeof (struct objfile));

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

              objfile->md = md;

              objfile->mmfd = fd;

              objfile->flags |= OBJF_MAPPED;

              mmalloc_setkey (objfile->md, 0, objfile);

              obstack_specify_allocation_with_arg (&objfile->psymbol_cache.cache,

                                                   0, 0, xmmalloc, mfree,

                                                   objfile->md);

              obstack_specify_allocation_with_arg (&objfile->psymbol_obstack,

                                                   0, 0, xmmalloc, mfree,

                                                   objfile->md);

              obstack_specify_allocation_with_arg (&objfile->symbol_obstack,

                                                   0, 0, xmmalloc, mfree,

                                                   objfile->md);

              obstack_specify_allocation_with_arg (&objfile->type_obstack,

                                                   0, 0, xmmalloc, mfree,

                                                   objfile->md);

            }

        }

      if ((flags & OBJF_MAPPED) && (objfile == NULL))

        {

          warning ("symbol table for '%s' will not be mapped",

                   bfd_get_filename (abfd));

          flags &= ~OBJF_MAPPED;

        }

    }

#else /* !defined(USE_MMALLOC) || !defined(HAVE_MMAP) */

  if (flags & OBJF_MAPPED)

    {

      warning ("mapped symbol tables are not supported on this machine; missing or broken mmap().");

      /* Turn off the global flag so we don't try to do mapped symbol tables

         any more, which shuts up gdb unless the user specifically gives the

         "mapped" keyword again. */

      mapped_symbol_files = 0;

      flags &= ~OBJF_MAPPED;

    }

#endif /* defined(USE_MMALLOC) && defined(HAVE_MMAP) */

  /* 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;

      obstack_specify_allocation (&objfile->psymbol_cache.cache, 0, 0,

                                  xmalloc, free);

      obstack_specify_allocation (&objfile->psymbol_obstack, 0, 0, xmalloc,

                                  free);

      obstack_specify_allocation (&objfile->symbol_obstack, 0, 0, xmalloc,

                                  free);

      obstack_specify_allocation (&objfile->type_obstack, 0, 0, xmalloc,

                                  free);

      flags &= ~OBJF_MAPPED;

    }

  /* 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)

    {

      mfree (objfile->md, objfile->name);

    }

  if (abfd != NULL)

    {

      objfile->name = mstrsave (objfile->md, 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 ()));

        }

    }

  /* 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);

}

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

void

objfile_to_front (objfile)

     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 (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 ("objfiles.c (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 symbol_obstack and

   psymbol_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 (objfile)

     struct objfile *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 ()));

      free (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. */

  /* I *think* all our callers call clear_symtab_users.  If so, no need

     to call this here.  */

  clear_pc_function_cache ();

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

     non-reusable case, or detach from the mapped file for the reusable

     case.  Note that the mmalloc_detach or the mfree is the last thing

     we can do with this objfile. */

#if defined(USE_MMALLOC) && defined(HAVE_MMAP)

  if (objfile->flags & OBJF_MAPPED)

    {

      /* Remember the fd so we can close it.  We can't close it before

         doing the detach, and after the detach the objfile is gone. */

      int mmfd;

      mmfd = objfile->mmfd;

      mmalloc_detach (objfile->md);

      objfile = NULL;

      close (mmfd);

    }

#endif /* defined(USE_MMALLOC) && defined(HAVE_MMAP) */

  /* If we still have an objfile, then either we don't support reusable

     objfiles or this one was not reusable.  So free it normally. */

  if (objfile != NULL)

    {

      if (objfile->name != NULL)

        {

          mfree (objfile->md, objfile->name);

        }

      if (objfile->global_psymbols.list)

        mfree (objfile->md, objfile->global_psymbols.list);

      if (objfile->static_psymbols.list)

        mfree (objfile->md, objfile->static_psymbols.list);

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

      free_bcache (&objfile->psymbol_cache);

      obstack_free (&objfile->psymbol_obstack, 0);

      obstack_free (&objfile->symbol_obstack, 0);

      obstack_free (&objfile->type_obstack, 0);

      mfree (objfile->md, objfile);

      objfile = NULL;

    }

}

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

void

free_all_objfiles ()

{

  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 (objfile, new_offsets)

     struct objfile *objfile;

     struct section_offsets *new_offsets;

{

  struct section_offsets *delta =

    (struct section_offsets *) alloca (SIZEOF_SECTION_OFFSETS);

  {

    int i;

    int something_changed = 0;

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

      {

        ANOFFSET (delta, 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;

          int j;

          b = BLOCKVECTOR_BLOCK (bv, i);

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

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

          for (j = 0; j < BLOCK_NSYMS (b); ++j)

            {

              struct symbol *sym = BLOCK_SYM (b, j);

              /* The RS6000 code from which this was taken skipped

                 any symbols in STRUCT_NAMESPACE or UNDEF_NAMESPACE.

                 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));

                }

#ifdef MIPS_EFI_SYMBOL_NAME

              /* Relocate Extra Function Info for ecoff.  */

              else if (SYMBOL_CLASS (sym) == LOC_CONST

                       && SYMBOL_NAMESPACE (sym) == LABEL_NAMESPACE

                   && STRCMP (SYMBOL_NAME (sym), MIPS_EFI_SYMBOL_NAME) == 0)

                ecoff_relocate_efi (sym, ANOFFSET (delta,

                                                   s->block_line_section));

#endif

            }

        }

    }

  }

  {

    struct partial_symtab *p;

    ALL_OBJFILE_PSYMTABS (objfile, p)

    {

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

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

    }

  }

  {

    struct partial_symbol **psym;

    for (psym = objfile->global_psymbols.list;

         psym < objfile->global_psymbols.next;

         psym++)

      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++)

      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)

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

  }

  {

    struct obj_section *s;

    bfd *abfd;

    abfd = objfile->obfd;

    ALL_OBJFILE_OSECTIONS (objfile, s)

      {

        flagword flags;

        flags = bfd_get_section_flags (abfd, s->the_bfd_section);

        if (flags & SEC_CODE)

          {

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

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

          }

        else if (flags & (SEC_DATA | SEC_LOAD))

          {

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

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

          }

        else if (flags & SEC_ALLOC)

          {

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

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

          }

      }

  }

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

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

  if (objfile->ei.entry_func_lowpc != INVALID_ENTRY_LOWPC)

    {

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

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

    }

  if (objfile->ei.entry_file_lowpc != INVALID_ENTRY_LOWPC)

    {

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

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

    }

  if (objfile->ei.main_func_lowpc != INVALID_ENTRY_LOWPC)

    {

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

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

    }

  /* 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 ()

{

  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