/* Standard argp argument parsers for tools using libdwfl.
   Copyright (C) 2005-2010 Red Hat, Inc.
   This file is part of Red Hat elfutils.

   Red Hat elfutils 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; version 2 of the License.

   Red Hat elfutils 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 Red Hat elfutils; if not, write to the Free Software Foundation,
   Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.

   In addition, as a special exception, Red Hat, Inc. gives You the
   additional right to link the code of Red Hat elfutils with code licensed
   under any Open Source Initiative certified open source license
   (http://www.opensource.org/licenses/index.php) which requires the
   distribution of source code with any binary distribution and to
   distribute linked combinations of the two.  Non-GPL Code permitted under
   this exception must only link to the code of Red Hat elfutils through
   those well defined interfaces identified in the file named EXCEPTION
   found in the source code files (the "Approved Interfaces").  The files
   of Non-GPL Code may instantiate templates or use macros or inline
   functions from the Approved Interfaces without causing the resulting
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   Inc. may make changes or additions to the list of Approved Interfaces.
   Red Hat's grant of this exception is conditioned upon your not adding
   any new exceptions.  If you wish to add a new Approved Interface or
   exception, please contact Red Hat.  You must obey the GNU General Public
   License in all respects for all of the Red Hat elfutils code and other
   code used in conjunction with Red Hat elfutils except the Non-GPL Code
   covered by this exception.  If you modify this file, you may extend this
   exception to your version of the file, but you are not obligated to do
   so.  If you do not wish to provide this exception without modification,
   you must delete this exception statement from your version and license
   this file solely under the GPL without exception.

   Red Hat elfutils is an included package of the Open Invention Network.
   An included package of the Open Invention Network is a package for which
   Open Invention Network licensees cross-license their patents.  No patent
   license is granted, either expressly or impliedly, by designation as an
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#include "libdwflP.h"
#include <argp.h>
#include <stdlib.h>
#include <assert.h>
#include <libintl.h>
#include <fcntl.h>
#include <unistd.h>

/* gettext helper macros.  */
#define _(Str) dgettext ("elfutils", Str)


#define OPT_DEBUGINFO	0x100
#define OPT_COREFILE	0x101

static const struct argp_option options[] =
{
  { NULL, 0, NULL, 0, N_("Input selection options:"), 0 },
  { "executable", 'e', "FILE", 0, N_("Find addresses in FILE"), 0 },
  { "core", OPT_COREFILE, "COREFILE", 0,
    N_("Find addresses from signatures found in COREFILE"), 0 },
  { "pid", 'p', "PID", 0,
    N_("Find addresses in files mapped into process PID"), 0 },
  { "linux-process-map", 'M', "FILE", 0,
    N_("Find addresses in files mapped as read from FILE"
       " in Linux /proc/PID/maps format"), 0 },
  { "kernel", 'k', NULL, 0, N_("Find addresses in the running kernel"), 0 },
  { "offline-kernel", 'K', "RELEASE", OPTION_ARG_OPTIONAL,
    N_("Kernel with all modules"), 0 },
  { "debuginfo-path", OPT_DEBUGINFO, "PATH", 0,
    N_("Search path for separate debuginfo files"), 0 },
  { NULL, 0, NULL, 0, NULL, 0 }
};

static char *debuginfo_path;

static const Dwfl_Callbacks offline_callbacks =
  {
    .find_debuginfo = INTUSE(dwfl_standard_find_debuginfo),
    .debuginfo_path = &debuginfo_path,

    .section_address = INTUSE(dwfl_offline_section_address),

    /* We use this table for core files too.  */
    .find_elf = INTUSE(dwfl_build_id_find_elf),
  };

static const Dwfl_Callbacks proc_callbacks =
  {
    .find_debuginfo = INTUSE(dwfl_standard_find_debuginfo),
    .debuginfo_path = &debuginfo_path,

    .find_elf = INTUSE(dwfl_linux_proc_find_elf),
  };

static const Dwfl_Callbacks kernel_callbacks =
  {
    .find_debuginfo = INTUSE(dwfl_standard_find_debuginfo),
    .debuginfo_path = &debuginfo_path,

    .find_elf = INTUSE(dwfl_linux_kernel_find_elf),
    .section_address = INTUSE(dwfl_linux_kernel_module_section_address),
  };

static error_t
parse_opt (int key, char *arg, struct argp_state *state)
{
  inline void failure (Dwfl *dwfl, int errnum, const char *msg)
    {
      if (dwfl != NULL)
	dwfl_end (dwfl);
      if (errnum == -1)
	argp_failure (state, EXIT_FAILURE, 0, "%s: %s",
		      msg, INTUSE(dwfl_errmsg) (-1));
      else
	argp_failure (state, EXIT_FAILURE, errnum, "%s", msg);
    }
  inline error_t fail (Dwfl *dwfl, int errnum, const char *msg)
    {
      failure (dwfl, errnum, msg);
      return errnum == -1 ? EIO : errnum;
    }

  switch (key)
    {
    case OPT_DEBUGINFO:
      debuginfo_path = arg;
      break;

    case 'e':
      {
	Dwfl *dwfl = state->hook;
	if (dwfl == NULL)
	  {
	    dwfl = INTUSE(dwfl_begin) (&offline_callbacks);
	    if (dwfl == NULL)
	      return fail (dwfl, -1, arg);
	    state->hook = dwfl;

	    /* Start at zero so if there is just one -e foo.so,
	       the DSO is shown without address bias.  */
	    dwfl->offline_next_address = 0;
	  }
	if (dwfl->callbacks == &offline_callbacks)
	  {
	    if (INTUSE(dwfl_report_offline) (dwfl, "", arg, -1) == NULL)
	      return fail (dwfl, -1, arg);
	    state->hook = dwfl;
	  }
	else
	  {
	  toomany:
	    argp_error (state, "%s",
			_("only one of -e, -p, -k, -K, or --core allowed"));
	    return EINVAL;
	  }
      }
      break;

    case 'p':
      if (state->hook == NULL)
	{
	  Dwfl *dwfl = INTUSE(dwfl_begin) (&proc_callbacks);
	  int result = INTUSE(dwfl_linux_proc_report) (dwfl, atoi (arg));
	  if (result != 0)
	    return fail (dwfl, result, arg);
	  state->hook = dwfl;
	}
      else
	goto toomany;
      break;

    case 'M':
      if (state->hook == NULL)
	{
	  FILE *f = fopen (arg, "r");
	  if (f == NULL)
	  nofile:
	    {
	      int code = errno;
	      argp_failure (state, EXIT_FAILURE, code,
			    "cannot open '%s'", arg);
	      return code;
	    }
	  Dwfl *dwfl = INTUSE(dwfl_begin) (&proc_callbacks);
	  int result = INTUSE(dwfl_linux_proc_maps_report) (dwfl, f);
	  fclose (f);
	  if (result != 0)
	    return fail (dwfl, result, arg);
	  state->hook = dwfl;
	}
      else
	goto toomany;
      break;

    case OPT_COREFILE:
      {
	Dwfl *dwfl = state->hook;
	if (dwfl == NULL)
	  state->hook = dwfl = INTUSE(dwfl_begin) (&offline_callbacks);
	/* Permit -e and --core together.  */
	else if (dwfl->callbacks != &offline_callbacks)
	  goto toomany;

	int fd = open64 (arg, O_RDONLY);
	if (fd < 0)
	  goto nofile;

	Elf *core;
	Dwfl_Error error = __libdw_open_file (&fd, &core, true, false);
	if (error != DWFL_E_NOERROR)
	  {
	    argp_failure (state, EXIT_FAILURE, 0,
			  _("cannot read ELF core file: %s"),
			  INTUSE(dwfl_errmsg) (error));
	    return error == DWFL_E_ERRNO ? errno : EIO;
	  }

	int result = INTUSE(dwfl_core_file_report) (dwfl, core);
	if (result < 0)
	  {
	    elf_end (core);
	    close (fd);
	    return fail (dwfl, result, arg);
	  }

	/* From now we leak FD and CORE.  */

	if (result == 0)
	  {
	    argp_failure (state, EXIT_FAILURE, 0,
			  _("No modules recognized in core file"));
	    return ENOENT;
	  }
      }
      break;

    case 'k':
      if (state->hook == NULL)
	{
	  Dwfl *dwfl = INTUSE(dwfl_begin) (&kernel_callbacks);
	  int result = INTUSE(dwfl_linux_kernel_report_kernel) (dwfl);
	  if (result != 0)
	    return fail (dwfl, result, _("cannot load kernel symbols"));
	  result = INTUSE(dwfl_linux_kernel_report_modules) (dwfl);
	  if (result != 0)
	    /* Non-fatal to have no modules since we do have the kernel.  */
	    failure (dwfl, result, _("cannot find kernel modules"));
	  state->hook = dwfl;
	}
      else
	goto toomany;
      break;

    case 'K':
      if (state->hook == NULL)
	{
	  Dwfl *dwfl = INTUSE(dwfl_begin) (&offline_callbacks);
	  int result = INTUSE(dwfl_linux_kernel_report_offline) (dwfl, arg,
								 NULL);
	  if (result != 0)
	    return fail (dwfl, result, _("cannot find kernel or modules"));
	  state->hook = dwfl;
	}
      else
	goto toomany;
      break;

    case ARGP_KEY_SUCCESS:
      {
	Dwfl *dwfl = state->hook;

	if (dwfl == NULL)
	  {
	    /* Default if no -e, -p, or -k, is "-e a.out".  */
	    arg = "a.out";
	    dwfl = INTUSE(dwfl_begin) (&offline_callbacks);
	    if (INTUSE(dwfl_report_offline) (dwfl, "", arg, -1) == NULL)
	      return fail (dwfl, -1, arg);
	    state->hook = dwfl;
	  }

	/* One of the three flavors has done dwfl_begin and some reporting
	   if we got here.  Tie up the Dwfl and return it to the caller of
	   argp_parse.  */

	int result = INTUSE(dwfl_report_end) (dwfl, NULL, NULL);
	assert (result == 0);
      }
      break;

    case ARGP_KEY_ERROR:
      dwfl_end (state->hook);
      state->hook = NULL;
      break;

    default:
      return ARGP_ERR_UNKNOWN;
    }

  /* Update the input all along, so a parent parser can see it.  */
  *(Dwfl **) state->input = state->hook;
  return 0;
}

static const struct argp libdwfl_argp =
  { .options = options, .parser = parse_opt };

const struct argp *
dwfl_standard_argp (void)
{
  return &libdwfl_argp;
}

#ifdef _MUDFLAP
/* In the absence of a mudflap wrapper for argp_parse, or a libc compiled
   with -fmudflap, we'll see spurious errors for using the struct argp_state
   on argp_parse's stack.  */

void __attribute__ ((constructor))
__libdwfl_argp_mudflap_options (void)
{
  __mf_set_options ("-heur-stack-bound");
}
#endif
