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/* Core dump and executable file functions below target vector, for GDB.

   Copyright 1986, 1987, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997,

   1998, 1999, 2000, 2001

   Free Software Foundation, 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 "gdb_string.h"

#include <errno.h>

#include <signal.h>

#include <fcntl.h>

#ifdef HAVE_SYS_FILE_H

#include <sys/file.h>           /* needed for F_OK and friends */

#endif

#include "frame.h"              /* required by inferior.h */

#include "inferior.h"

#include "symtab.h"

#include "command.h"

#include "bfd.h"

#include "target.h"

#include "gdbcore.h"

#include "gdbthread.h"

#include "regcache.h"

#ifndef O_BINARY

#define O_BINARY 0

#endif

/* List of all available core_fns.  On gdb startup, each core file register

   reader calls add_core_fns() to register information on each core format it

   is prepared to read. */

static struct core_fns *core_file_fns = NULL;

/* The core_fns for a core file handler that is prepared to read the core

   file currently open on core_bfd. */

static struct core_fns *core_vec = NULL;

static void core_files_info (struct target_ops *);

#ifdef SOLIB_ADD

static int solib_add_stub (PTR);

#endif

static struct core_fns *sniff_core_bfd (bfd *);

static boolean gdb_check_format (bfd *);

static void core_open (char *, int);

static void core_detach (char *, int);

static void core_close (int);

static void core_close_cleanup (void *ignore);

static void get_core_registers (int);

static void add_to_thread_list (bfd *, asection *, PTR);

static int ignore (CORE_ADDR, char *);

static int core_file_thread_alive (ptid_t tid);

static void init_core_ops (void);

void _initialize_corelow (void);

struct target_ops core_ops;

/* Link a new core_fns into the global core_file_fns list.  Called on gdb

   startup by the _initialize routine in each core file register reader, to

   register information about each format the the reader is prepared to

   handle. */

void

add_core_fns (struct core_fns *cf)

{

  cf->next = core_file_fns;

  core_file_fns = cf;

}

/* The default function that core file handlers can use to examine a

   core file BFD and decide whether or not to accept the job of

   reading the core file. */

int

default_core_sniffer (struct core_fns *our_fns, bfd *abfd)

{

  int result;

  result = (bfd_get_flavour (abfd) == our_fns -> core_flavour);

  return (result);

}

/* Walk through the list of core functions to find a set that can

   handle the core file open on ABFD.  Default to the first one in the

   list if nothing matches.  Returns pointer to set that is

   selected. */

static struct core_fns *

sniff_core_bfd (bfd *abfd)

{

  struct core_fns *cf;

  struct core_fns *yummy = NULL;

  int matches = 0;;

  for (cf = core_file_fns; cf != NULL; cf = cf->next)

    {

      if (cf->core_sniffer (cf, abfd))

        {

          yummy = cf;

          matches++;

        }

    }

  if (matches > 1)

    {

      warning ("\"%s\": ambiguous core format, %d handlers match",

               bfd_get_filename (abfd), matches);

    }

  else if (matches == 0)

    {

      warning ("\"%s\": no core file handler recognizes format, using default",

               bfd_get_filename (abfd));

    }

  if (yummy == NULL)

    {

      yummy = core_file_fns;

    }

  return (yummy);

}

/* The default is to reject every core file format we see.  Either

   BFD has to recognize it, or we have to provide a function in the

   core file handler that recognizes it. */

int

default_check_format (bfd *abfd)

{

  return (0);

}

/* Attempt to recognize core file formats that BFD rejects. */

static boolean

gdb_check_format (bfd *abfd)

{

  struct core_fns *cf;

  for (cf = core_file_fns; cf != NULL; cf = cf->next)

    {

      if (cf->check_format (abfd))

        {

          return (true);

        }

    }

  return (false);

}

/* Discard all vestiges of any previous core file and mark data and stack

   spaces as empty.  */

/* ARGSUSED */

static void

core_close (int quitting)

{

  char *name;

  if (core_bfd)

    {

      inferior_ptid = null_ptid;        /* Avoid confusion from thread stuff */

      /* Clear out solib state while the bfd is still open. See

         comments in clear_solib in solib.c. */

#ifdef CLEAR_SOLIB

      CLEAR_SOLIB ();

#endif

      name = bfd_get_filename (core_bfd);

      if (!bfd_close (core_bfd))

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

                 name, bfd_errmsg (bfd_get_error ()));

      xfree (name);

      core_bfd = NULL;

      if (core_ops.to_sections)

        {

          xfree (core_ops.to_sections);

          core_ops.to_sections = NULL;

          core_ops.to_sections_end = NULL;

        }

    }

  core_vec = NULL;

}

static void

core_close_cleanup (void *ignore)

{

  core_close (0/*ignored*/);

}

#ifdef SOLIB_ADD

/* Stub function for catch_errors around shared library hacking.  FROM_TTYP

   is really an int * which points to from_tty.  */

static int

solib_add_stub (PTR from_ttyp)

{

  SOLIB_ADD (NULL, *(int *) from_ttyp, &current_target);

  re_enable_breakpoints_in_shlibs ();

  return 0;

}

#endif /* SOLIB_ADD */

/* Look for sections whose names start with `.reg/' so that we can extract the

   list of threads in a core file.  */

static void

add_to_thread_list (bfd *abfd, asection *asect, PTR reg_sect_arg)

{

  int thread_id;

  asection *reg_sect = (asection *) reg_sect_arg;

  if (strncmp (bfd_section_name (abfd, asect), ".reg/", 5) != 0)

    return;

  thread_id = atoi (bfd_section_name (abfd, asect) + 5);

  add_thread (pid_to_ptid (thread_id));

/* Warning, Will Robinson, looking at BFD private data! */

  if (reg_sect != NULL

      && asect->filepos == reg_sect->filepos)   /* Did we find .reg? */

    inferior_ptid = pid_to_ptid (thread_id);    /* Yes, make it current */

}

/* This routine opens and sets up the core file bfd.  */

static void

core_open (char *filename, int from_tty)

{

  const char *p;

  int siggy;

  struct cleanup *old_chain;

  char *temp;

  bfd *temp_bfd;

  int ontop;

  int scratch_chan;

  target_preopen (from_tty);

  if (!filename)

    {

      error (core_bfd ?

             "No core file specified.  (Use `detach' to stop debugging a core file.)"

             : "No core file specified.");

    }

  filename = tilde_expand (filename);

  if (filename[0] != '/')

    {

      temp = concat (current_directory, "/", filename, NULL);

      xfree (filename);

      filename = temp;

    }

  old_chain = make_cleanup (xfree, filename);

  scratch_chan = open (filename, O_BINARY | ( write_files ? O_RDWR : O_RDONLY ), 0);

  if (scratch_chan < 0)

    perror_with_name (filename);

  temp_bfd = bfd_fdopenr (filename, gnutarget, scratch_chan);

  if (temp_bfd == NULL)

    perror_with_name (filename);

  if (!bfd_check_format (temp_bfd, bfd_core) &&

      !gdb_check_format (temp_bfd))

    {

      /* Do it after the err msg */

      /* FIXME: should be checking for errors from bfd_close (for one thing,

         on error it does not free all the storage associated with the

         bfd).  */

      make_cleanup_bfd_close (temp_bfd);

      error ("\"%s\" is not a core dump: %s",

             filename, bfd_errmsg (bfd_get_error ()));

    }

  /* Looks semi-reasonable.  Toss the old core file and work on the new.  */

  discard_cleanups (old_chain); /* Don't free filename any more */

  unpush_target (&core_ops);

  core_bfd = temp_bfd;

  old_chain = make_cleanup (core_close_cleanup, 0 /*ignore*/);

  /* Find a suitable core file handler to munch on core_bfd */

  core_vec = sniff_core_bfd (core_bfd);

  validate_files ();

  /* Find the data section */

  if (build_section_table (core_bfd, &core_ops.to_sections,

                           &core_ops.to_sections_end))

    error ("\"%s\": Can't find sections: %s",

           bfd_get_filename (core_bfd), bfd_errmsg (bfd_get_error ()));

  set_gdbarch_from_file (core_bfd);

  ontop = !push_target (&core_ops);

  discard_cleanups (old_chain);

  p = bfd_core_file_failing_command (core_bfd);

  if (p)

    printf_filtered ("Core was generated by `%s'.\n", p);

  siggy = bfd_core_file_failing_signal (core_bfd);

  if (siggy > 0)

    /* NOTE: target_signal_from_host() converts a target signal value

       into gdb's internal signal value.  Unfortunately gdb's internal

       value is called ``target_signal'' and this function got the

       name ..._from_host(). */

    printf_filtered ("Program terminated with signal %d, %s.\n", siggy,

                     target_signal_to_string (target_signal_from_host (siggy)));

  /* Build up thread list from BFD sections. */

  init_thread_list ();

  bfd_map_over_sections (core_bfd, add_to_thread_list,

                         bfd_get_section_by_name (core_bfd, ".reg"));

  if (ontop)

    {

      /* Fetch all registers from core file.  */

      target_fetch_registers (-1);

      /* Add symbols and section mappings for any shared libraries.  */

#ifdef SOLIB_ADD

      catch_errors (solib_add_stub, &from_tty, (char *) 0,

                    RETURN_MASK_ALL);

#endif

      /* Now, set up the frame cache, and print the top of stack.  */

      flush_cached_frames ();

      select_frame (get_current_frame (), 0);

      print_stack_frame (selected_frame, selected_frame_level, 1);

    }

  else

    {

      warning (

                "you won't be able to access this core file until you terminate\n\

your %s; do ``info files''", target_longname);

    }

}

static void

core_detach (char *args, int from_tty)

{

  if (args)

    error ("Too many arguments");

  unpush_target (&core_ops);

  reinit_frame_cache ();

  if (from_tty)

    printf_filtered ("No core file now.\n");

}

/* Try to retrieve registers from a section in core_bfd, and supply

   them to core_vec->core_read_registers, as the register set numbered

   WHICH.

   If inferior_ptid is zero, do the single-threaded thing: look for a

   section named NAME.  If inferior_ptid is non-zero, do the

   multi-threaded thing: look for a section named "NAME/PID", where

   PID is the shortest ASCII decimal representation of inferior_ptid.

   HUMAN_NAME is a human-readable name for the kind of registers the

   NAME section contains, for use in error messages.

   If REQUIRED is non-zero, print an error if the core file doesn't

   have a section by the appropriate name.  Otherwise, just do nothing.  */

static void

get_core_register_section (char *name,

                           int which,

                           char *human_name,

                           int required)

{

  char section_name[100];

  sec_ptr section;

  bfd_size_type size;

  char *contents;

  if (PIDGET (inferior_ptid))

    sprintf (section_name, "%s/%d", name, PIDGET (inferior_ptid));

  else

    strcpy (section_name, name);

  section = bfd_get_section_by_name (core_bfd, section_name);

  if (! section)

    {

      if (required)

        warning ("Couldn't find %s registers in core file.\n", human_name);

      return;

    }

  size = bfd_section_size (core_bfd, section);

  contents = alloca (size);

  if (! bfd_get_section_contents (core_bfd, section, contents,

                                  (file_ptr) 0, size))

    {

      warning ("Couldn't read %s registers from `%s' section in core file.\n",

               human_name, name);

      return;

    }

  core_vec->core_read_registers (contents, size, which,

                                 ((CORE_ADDR)

                                  bfd_section_vma (core_bfd, section)));

}

/* Get the registers out of a core file.  This is the machine-

   independent part.  Fetch_core_registers is the machine-dependent

   part, typically implemented in the xm-file for each architecture.  */

/* We just get all the registers, so we don't use regno.  */

/* ARGSUSED */

static void

get_core_registers (int regno)

{

  int status;

  if (core_vec == NULL

      || core_vec->core_read_registers == NULL)

    {

      fprintf_filtered (gdb_stderr,

                     "Can't fetch registers from this type of core file\n");

      return;

    }

  get_core_register_section (".reg", 0, "general-purpose", 1);

  get_core_register_section (".reg2", 2, "floating-point", 0);

  get_core_register_section (".reg-xfp", 3, "extended floating-point", 0);

  registers_fetched ();

}

static void

core_files_info (struct target_ops *t)

{

  print_section_info (t, core_bfd);

}

/* If mourn is being called in all the right places, this could be say

   `gdb internal error' (since generic_mourn calls breakpoint_init_inferior).  */

static int

ignore (CORE_ADDR addr, char *contents)

{

  return 0;

}

/* Okay, let's be honest: threads gleaned from a core file aren't

   exactly lively, are they?  On the other hand, if we don't claim

   that each & every one is alive, then we don't get any of them

   to appear in an "info thread" command, which is quite a useful

   behaviour.

 */

static int

core_file_thread_alive (ptid_t tid)

{

  return 1;

}

/* Fill in core_ops with its defined operations and properties.  */

static void

init_core_ops (void)

{

  core_ops.to_shortname = "core";

  core_ops.to_longname = "Local core dump file";

  core_ops.to_doc =

    "Use a core file as a target.  Specify the filename of the core file.";

  core_ops.to_open = core_open;

  core_ops.to_close = core_close;

  core_ops.to_attach = find_default_attach;

  core_ops.to_require_attach = find_default_require_attach;

  core_ops.to_detach = core_detach;

  core_ops.to_require_detach = find_default_require_detach;

  core_ops.to_fetch_registers = get_core_registers;

  core_ops.to_xfer_memory = xfer_memory;

  core_ops.to_files_info = core_files_info;

  core_ops.to_insert_breakpoint = ignore;

  core_ops.to_remove_breakpoint = ignore;

  core_ops.to_create_inferior = find_default_create_inferior;

  core_ops.to_clone_and_follow_inferior = find_default_clone_and_follow_inferior;

  core_ops.to_thread_alive = core_file_thread_alive;

  core_ops.to_stratum = core_stratum;

  core_ops.to_has_memory = 1;

  core_ops.to_has_stack = 1;

  core_ops.to_has_registers = 1;

  core_ops.to_magic = OPS_MAGIC;

}

/* non-zero if we should not do the add_target call in

   _initialize_corelow; not initialized (i.e., bss) so that

   the target can initialize it (i.e., data) if appropriate.

   This needs to be set at compile time because we don't know

   for sure whether the target's initialize routine is called

   before us or after us. */

int coreops_suppress_target;

void

_initialize_corelow (void)

{

  init_core_ops ();

  if (!coreops_suppress_target)

    add_target (&core_ops);

}