/* Print symbol information from ELF file in human-readable form.
   Copyright (C) 2000-2008, 2009, 2011, 2012, 2014, 2015 Red Hat, Inc.
   This file is part of elfutils.
   Written by Ulrich Drepper <drepper@redhat.com>, 2000.

   This file 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.

   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 this program.  If not, see <http://www.gnu.org/licenses/>.  */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include <ar.h>
#include <argp.h>
#include <assert.h>
#include <ctype.h>
#include <dwarf.h>
#include <errno.h>
#include <fcntl.h>
#include <gelf.h>
#include <inttypes.h>
#include <libdw.h>
#include <libintl.h>
#include <locale.h>
#include <obstack.h>
#include <search.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdio_ext.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <libeu.h>
#include <system.h>
#include <color.h>
#include <printversion.h>
#include "../libebl/libeblP.h"
#include "../libdwfl/libdwflP.h"


/* Name and version of program.  */
ARGP_PROGRAM_VERSION_HOOK_DEF = print_version;

/* Bug report address.  */
ARGP_PROGRAM_BUG_ADDRESS_DEF = PACKAGE_BUGREPORT;


/* Values for the parameters which have no short form.  */
#define OPT_DEFINED		0x100
#define OPT_MARK_SPECIAL	0x101

/* Definitions of arguments for argp functions.  */
static const struct argp_option options[] =
{
  { NULL, 0, NULL, 0, N_("Output selection:"), 0 },
  { "debug-syms", 'a', NULL, 0, N_("Display debugger-only symbols"), 0 },
  { "defined-only", OPT_DEFINED, NULL, 0, N_("Display only defined symbols"),
    0 },
  { "dynamic", 'D', NULL, 0,
    N_("Display dynamic symbols instead of normal symbols"), 0 },
  { "extern-only", 'g', NULL, 0, N_("Display only external symbols"), 0 },
  { "undefined-only", 'u', NULL, 0, N_("Display only undefined symbols"), 0 },
  { "print-armap", 's', NULL, 0,
    N_("Include index for symbols from archive members"), 0 },

  { NULL, 0, NULL, 0, N_("Output format:"), 0 },
  { "print-file-name", 'A', NULL, 0,
    N_("Print name of the input file before every symbol"), 0 },
  { NULL, 'o', NULL, OPTION_HIDDEN, "Same as -A", 0 },
  { "format", 'f', "FORMAT", 0,
    N_("Use the output format FORMAT.  FORMAT can be `bsd', `sysv' or `posix'.  The default is `sysv'"),
    0 },
  { NULL, 'B', NULL, 0, N_("Same as --format=bsd"), 0 },
  { "portability", 'P', NULL, 0, N_("Same as --format=posix"), 0 },
  { "radix", 't', "RADIX", 0, N_("Use RADIX for printing symbol values"), 0 },
  { "mark-special", OPT_MARK_SPECIAL, NULL, 0, N_("Mark special symbols"), 0 },
  { "mark-weak", OPT_MARK_SPECIAL, NULL, OPTION_HIDDEN, "", 0 },
  { "print-size", 'S', NULL, 0, N_("Print size of defined symbols"), 0 },

  { NULL, 0, NULL, 0, N_("Output options:"), 0 },
  { "numeric-sort", 'n', NULL, 0, N_("Sort symbols numerically by address"),
    0 },
  { "no-sort", 'p', NULL, 0, N_("Do not sort the symbols"), 0 },
  { "reverse-sort", 'r', NULL, 0, N_("Reverse the sense of the sort"), 0 },
#ifdef USE_DEMANGLE
  { "demangle", 'C', NULL, 0,
    N_("Decode low-level symbol names into source code names"), 0 },
#endif
  { NULL, 0, NULL, 0, N_("Miscellaneous:"), 0 },
  { NULL, 0, NULL, 0, NULL, 0 }
};

/* Short description of program.  */
static const char doc[] = N_("List symbols from FILEs (a.out by default).");

/* Strings for arguments in help texts.  */
static const char args_doc[] = N_("[FILE...]");

/* Prototype for option handler.  */
static error_t parse_opt (int key, char *arg, struct argp_state *state);

/* Parser children.  */
static struct argp_child argp_children[] =
  {
    { &color_argp, 0, N_("Output formatting"), 2 },
    { NULL, 0, NULL, 0}
  };

/* Data structure to communicate with argp functions.  */
static struct argp argp =
{
  options, parse_opt, args_doc, doc, argp_children, NULL, NULL
};


/* Print symbols in file named FNAME.  */
static int process_file (const char *fname, bool more_than_one);

/* Handle content of archive.  */
static int handle_ar (int fd, Elf *elf, const char *prefix, const char *fname,
		      const char *suffix);

/* Handle ELF file.  */
static int handle_elf (int fd, Elf *elf, const char *prefix, const char *fname,
		       const char *suffix);


#define INTERNAL_ERROR(fname) \
  error (EXIT_FAILURE, 0, gettext ("%s: INTERNAL ERROR %d (%s): %s"),      \
	 fname, __LINE__, PACKAGE_VERSION, elf_errmsg (-1))


/* Internal representation of symbols.  */
typedef struct GElf_SymX
{
  GElf_Sym sym;
  Elf32_Word xndx;
  char *where;
} GElf_SymX;


/* User-selectable options.  */

/* The selected output format.  */
static enum
{
  format_sysv = 0,
  format_bsd,
  format_posix
} format;

/* Print defined, undefined, or both?  */
static bool hide_undefined;
static bool hide_defined;

/* Print local symbols also?  */
static bool hide_local;

/* Nonzero if full filename should precede every symbol.  */
static bool print_file_name;

/* If true print size of defined symbols in BSD format.  */
static bool print_size;

/* If true print archive index.  */
static bool print_armap;

/* If true reverse sorting.  */
static bool reverse_sort;

#ifdef USE_DEMANGLE
/* If true demangle symbols.  */
static bool demangle;
#endif

/* Type of the section we are printing.  */
static GElf_Word symsec_type = SHT_SYMTAB;

/* Sorting selection.  */
static enum
{
  sort_name = 0,
  sort_numeric,
  sort_nosort
} sort;

/* Radix for printed numbers.  */
static enum
{
  radix_hex = 0,
  radix_decimal,
  radix_octal
} radix;

/* If nonzero mark special symbols:
   - weak symbols are distinguished from global symbols by adding
     a `*' after the identifying letter for the symbol class and type.
   - TLS symbols are distinguished from normal symbols by adding
     a '@' after the identifying letter for the symbol class and type.  */
static bool mark_special;


int
main (int argc, char *argv[])
{
  int remaining;
  int result = 0;

  /* We use no threads here which can interfere with handling a stream.  */
  (void) __fsetlocking (stdin, FSETLOCKING_BYCALLER);
  (void) __fsetlocking (stdout, FSETLOCKING_BYCALLER);
  (void) __fsetlocking (stderr, FSETLOCKING_BYCALLER);

  /* Set locale.  */
  (void) setlocale (LC_ALL, "");

  /* Make sure the message catalog can be found.  */
  (void) bindtextdomain (PACKAGE_TARNAME, LOCALEDIR);

  /* Initialize the message catalog.  */
  (void) textdomain (PACKAGE_TARNAME);

  /* Parse and process arguments.  */
  (void) argp_parse (&argp, argc, argv, 0, &remaining, NULL);

  /* Tell the library which version we are expecting.  */
  (void) elf_version (EV_CURRENT);

  if (remaining == argc)
    /* The user didn't specify a name so we use a.out.  */
    result = process_file ("a.out", false);
  else
    {
      /* Process all the remaining files.  */
      const bool more_than_one = remaining + 1 < argc;

      do
	result |= process_file (argv[remaining], more_than_one);
      while (++remaining < argc);
    }

  return result;
}


/* Handle program arguments.  */
static error_t
parse_opt (int key, char *arg,
	   struct argp_state *state __attribute__ ((unused)))
{
  switch (key)
    {
    case 'a':
      /* XXX */
      break;

#ifdef USE_DEMANGLE
    case 'C':
      demangle = true;
      break;
#endif

    case 'f':
      if (strcmp (arg, "bsd") == 0)
	format = format_bsd;
      else if (strcmp (arg, "posix") == 0)
	format = format_posix;
      else
	/* Be bug compatible.  The BFD implementation also defaulted to
	   using the SysV format if nothing else matches.  */
	format = format_sysv;
      break;

    case 'g':
      hide_local = true;
      break;

    case 'n':
      sort = sort_numeric;
      break;

    case 'p':
      sort = sort_nosort;
      break;

    case 't':
      if (strcmp (arg, "10") == 0 || strcmp (arg, "d") == 0)
	radix = radix_decimal;
      else if (strcmp (arg, "8") == 0 || strcmp (arg, "o") == 0)
	radix = radix_octal;
      else
	radix = radix_hex;
      break;

    case 'u':
      hide_undefined = false;
      hide_defined = true;
      break;

    case 'A':
    case 'o':
      print_file_name = true;
      break;

    case 'B':
      format = format_bsd;
      break;

    case 'D':
      symsec_type = SHT_DYNSYM;
      break;

    case 'P':
      format = format_posix;
      break;

    case OPT_DEFINED:
      hide_undefined = true;
      hide_defined = false;
      break;

    case OPT_MARK_SPECIAL:
      mark_special = true;
      break;

    case 'S':
      print_size = true;
      break;

    case 's':
      print_armap = true;
      break;

    case 'r':
      reverse_sort = true;
      break;

    default:
      return ARGP_ERR_UNKNOWN;
    }
  return 0;
}


/* Open the file and determine the type.  */
static int
process_file (const char *fname, bool more_than_one)
{
  /* Open the file.  */
  int fd = open (fname, O_RDONLY);
  if (fd == -1)
    {
      error (0, errno, gettext ("cannot open '%s'"), fname);
      return 1;
    }

  /* Now get the ELF descriptor.  */
  Elf *elf = elf_begin (fd, ELF_C_READ_MMAP, NULL);
  if (elf != NULL)
    {
      if (elf_kind (elf) == ELF_K_ELF)
	{
	  int result = handle_elf (fd, elf, more_than_one ? "" : NULL,
				   fname, NULL);

	  if (elf_end (elf) != 0)
	    INTERNAL_ERROR (fname);

	  if (close (fd) != 0)
	    error (EXIT_FAILURE, errno, gettext ("while closing '%s'"), fname);

	  return result;
	}
      else if (elf_kind (elf) == ELF_K_AR)
	{
	  int result = handle_ar (fd, elf, NULL, fname, NULL);

	  if (elf_end (elf) != 0)
	    INTERNAL_ERROR (fname);

	  if (close (fd) != 0)
	    error (EXIT_FAILURE, errno, gettext ("while closing '%s'"), fname);

	  return result;
	}

      /* We cannot handle this type.  Close the descriptor anyway.  */
      if (elf_end (elf) != 0)
	INTERNAL_ERROR (fname);
    }

  error (0, 0, gettext ("%s: File format not recognized"), fname);

  return 1;
}


static int
handle_ar (int fd, Elf *elf, const char *prefix, const char *fname,
	   const char *suffix)
{
  size_t fname_len = strlen (fname) + 1;
  size_t prefix_len = prefix != NULL ? strlen (prefix) : 0;
  char new_prefix[prefix_len + fname_len + 2];
  size_t suffix_len = suffix != NULL ? strlen (suffix) : 0;
  char new_suffix[suffix_len + 2];
  Elf *subelf;
  Elf_Cmd cmd = ELF_C_READ_MMAP;
  int result = 0;

  char *cp = new_prefix;
  if (prefix != NULL)
    cp = stpcpy (cp, prefix);
  cp = stpcpy (cp, fname);
  stpcpy (cp, "[");

  cp = new_suffix;
  if (suffix != NULL)
    cp = stpcpy (cp, suffix);
  stpcpy (cp, "]");

  /* First print the archive index if this is wanted.  */
  if (print_armap)
    {
      Elf_Arsym *arsym = elf_getarsym (elf, NULL);

      if (arsym != NULL)
	{
	  Elf_Arhdr *arhdr = NULL;
	  size_t arhdr_off = 0;	/* Note: 0 is no valid offset.  */

	  fputs_unlocked (gettext("\nArchive index:\n"), stdout);

	  while (arsym->as_off != 0)
	    {
	      if (arhdr_off != arsym->as_off
		  && (elf_rand (elf, arsym->as_off) != arsym->as_off
		      || (subelf = elf_begin (fd, cmd, elf)) == NULL
		      || (arhdr = elf_getarhdr (subelf)) == NULL))
		{
		  error (0, 0, gettext ("invalid offset %zu for symbol %s"),
			 arsym->as_off, arsym->as_name);
		  break;
		}

	      printf (gettext ("%s in %s\n"), arsym->as_name, arhdr->ar_name);

	      ++arsym;
	    }

	  if (elf_rand (elf, SARMAG) != SARMAG)
	    {
	      error (0, 0,
		     gettext ("cannot reset archive offset to beginning"));
	      return 1;
	    }
	}
    }

  /* Process all the files contained in the archive.  */
  while ((subelf = elf_begin (fd, cmd, elf)) != NULL)
    {
      /* The the header for this element.  */
      Elf_Arhdr *arhdr = elf_getarhdr (subelf);

      /* Skip over the index entries.  */
      if (strcmp (arhdr->ar_name, "/") != 0
	  && strcmp (arhdr->ar_name, "//") != 0
	  && strcmp (arhdr->ar_name, "/SYM64/") != 0)
	{
	  if (elf_kind (subelf) == ELF_K_ELF)
	    result |= handle_elf (fd, subelf, new_prefix, arhdr->ar_name,
				  new_suffix);
	  else if (elf_kind (subelf) == ELF_K_AR)
	    result |= handle_ar (fd, subelf, new_prefix, arhdr->ar_name,
				 new_suffix);
	  else
	    {
	      error (0, 0, gettext ("%s%s%s: file format not recognized"),
		     new_prefix, arhdr->ar_name, new_suffix);
	      result = 1;
	    }
	}

      /* Get next archive element.  */
      cmd = elf_next (subelf);
      if (elf_end (subelf) != 0)
	INTERNAL_ERROR (fname);
    }

  return result;
}


/* Mapping of radix and binary class to length.  */
static const int length_map[2][3] =
{
  [ELFCLASS32 - 1] =
  {
    [radix_hex] = 8,
    [radix_decimal] = 10,
    [radix_octal] = 11
  },
  [ELFCLASS64 - 1] =
  {
    [radix_hex] = 16,
    [radix_decimal] = 20,
    [radix_octal] = 22
  }
};


static int
global_compare (const void *p1, const void *p2)
{
  const Dwarf_Global *g1 = (const Dwarf_Global *) p1;
  const Dwarf_Global *g2 = (const Dwarf_Global *) p2;

  return strcmp (g1->name, g2->name);
}


static void *global_root;


static int
get_global (Dwarf *dbg __attribute__ ((unused)), Dwarf_Global *global,
	    void *arg __attribute__ ((unused)))
{
  tsearch (memcpy (xmalloc (sizeof (Dwarf_Global)), global,
		   sizeof (Dwarf_Global)),
	   &global_root, global_compare);

  return DWARF_CB_OK;
}


struct local_name
{
  const char *name;
  const char *file;
  Dwarf_Word lineno;
  Dwarf_Addr lowpc;
  Dwarf_Addr highpc;
};


static int
local_compare (const void *p1, const void *p2)
{
  struct local_name *g1 = (struct local_name *) p1;
  struct local_name *g2 = (struct local_name *) p2;
  int result;

  result = strcmp (g1->name, g2->name);
  if (result == 0)
    {
      if (g1->lowpc <= g2->lowpc && g1->highpc >= g2->highpc)
	{
	  /* g2 is contained in g1.  Update the data.  */
	  g2->lowpc = g1->lowpc;
	  g2->highpc = g1->highpc;
	  result = 0;
	}
      else if (g2->lowpc <= g1->lowpc && g2->highpc >= g1->highpc)
	{
	  /* g1 is contained in g2.  Update the data.  */
	  g1->lowpc = g2->lowpc;
	  g1->highpc = g2->highpc;
	  result = 0;
	}
      else
	result = g1->lowpc < g2->lowpc ? -1 : 1;
    }

  return result;
}


static int
get_var_range (Dwarf_Die *die, Dwarf_Word *lowpc, Dwarf_Word *highpc)
{
  Dwarf_Attribute locattr_mem;
  Dwarf_Attribute *locattr = dwarf_attr (die, DW_AT_location, &locattr_mem);
  if  (locattr == NULL)
    return 1;

  Dwarf_Op *loc;
  size_t nloc;
  if (dwarf_getlocation (locattr, &loc, &nloc) != 0)
    return 1;

  /* Interpret the location expressions.  */
  // XXX For now just the simple one:
  if (nloc == 1 && loc[0].atom == DW_OP_addr)
    {
      *lowpc = *highpc = loc[0].number;
      return 0;
    }

  return 1;
}



static void *local_root;


static void
get_local_names (Dwarf *dbg)
{
  Dwarf_Off offset = 0;
  Dwarf_Off old_offset;
  size_t hsize;

  while (dwarf_nextcu (dbg, old_offset = offset, &offset, &hsize, NULL, NULL,
		       NULL) == 0)
    {
      Dwarf_Die cudie_mem;
      Dwarf_Die *cudie = dwarf_offdie (dbg, old_offset + hsize, &cudie_mem);

      /* If we cannot get the CU DIE there is no need to go on with
	 this CU.  */
      if (cudie == NULL)
	continue;
      /* This better be a CU DIE.  */
      if (dwarf_tag (cudie) != DW_TAG_compile_unit)
	continue;

      /* Get the line information.  */
      Dwarf_Files *files;
      size_t nfiles;
      if (dwarf_getsrcfiles (cudie, &files, &nfiles) != 0)
	continue;

      Dwarf_Die die_mem;
      Dwarf_Die *die = &die_mem;
      if (dwarf_child (cudie, die) == 0)
	/* Iterate over all immediate children of the CU DIE.  */
	do
	  {
	    int tag = dwarf_tag (die);
	    if (tag != DW_TAG_subprogram && tag != DW_TAG_variable)
	      continue;

	    /* We are interested in five attributes: name, decl_file,
	       decl_line, low_pc, and high_pc.  */
	    Dwarf_Attribute attr_mem;
	    Dwarf_Attribute *attr = dwarf_attr (die, DW_AT_name, &attr_mem);
	    const char *name = dwarf_formstring (attr);
	    if (name == NULL)
	      continue;

	    Dwarf_Word fileidx;
	    attr = dwarf_attr (die, DW_AT_decl_file, &attr_mem);
	    if (dwarf_formudata (attr, &fileidx) != 0 || fileidx >= nfiles)
	      continue;

	    Dwarf_Word lineno;
	    attr = dwarf_attr (die, DW_AT_decl_line, &attr_mem);
	    if (dwarf_formudata (attr, &lineno) != 0 || lineno == 0)
	      continue;

	    Dwarf_Addr lowpc;
	    Dwarf_Addr highpc;
	    if (tag == DW_TAG_subprogram)
	      {
		if (dwarf_lowpc (die, &lowpc) != 0
		    || dwarf_highpc (die, &highpc) != 0)
		  continue;
	      }
	    else
	      {
		if (get_var_range (die, &lowpc, &highpc) != 0)
		  continue;
	      }

	    /* We have all the information.  Create a record.  */
	    struct local_name *newp
	      = (struct local_name *) xmalloc (sizeof (*newp));
	    newp->name = name;
	    newp->file = dwarf_filesrc (files, fileidx, NULL, NULL);
	    newp->lineno = lineno;
	    newp->lowpc = lowpc;
	    newp->highpc = highpc;

	   /* Check whether a similar local_name is already in the
	      cache.  That should not happen.  But if it does, we
	      don't want to leak memory.  */
	    struct local_name **tres = tsearch (newp, &local_root,
						local_compare);
	    if (tres == NULL)
              error (EXIT_FAILURE, errno,
                     gettext ("cannot create search tree"));
	    else if (*tres != newp)
	      free (newp);
	  }
	while (dwarf_siblingof (die, die) == 0);
    }
}

/* Do elf_strptr, but return a backup string and never NULL.  */
static const char *
sym_name (Elf *elf, GElf_Word strndx, GElf_Word st_name, char buf[], size_t n)
{
  const char *symstr = elf_strptr (elf, strndx, st_name);
  if (symstr == NULL)
    {
      snprintf (buf, n, "[invalid st_name %#" PRIx32 "]", st_name);
      symstr = buf;
    }
  return symstr;
}

/* Show symbols in SysV format.  */
static void
show_symbols_sysv (Ebl *ebl, GElf_Word strndx, const char *fullname,
		   GElf_SymX *syms, size_t nsyms, int longest_name,
		   int longest_where)
{
  size_t shnum;
  if (elf_getshdrnum (ebl->elf, &shnum) < 0)
    INTERNAL_ERROR (fullname);

  bool scnnames_malloced = shnum * sizeof (const char *) > 128 * 1024;
  const char **scnnames;
  if (scnnames_malloced)
    scnnames = (const char **) xmalloc (sizeof (const char *) * shnum);
  else
    scnnames = (const char **) alloca (sizeof (const char *) * shnum);
  /* Get the section header string table index.  */
  size_t shstrndx;
  if (elf_getshdrstrndx (ebl->elf, &shstrndx) < 0)
    error (EXIT_FAILURE, 0,
	   gettext ("cannot get section header string table index"));

  /* Cache the section names.  */
  Elf_Scn *scn = NULL;
  size_t cnt = 1;
  while ((scn = elf_nextscn (ebl->elf, scn)) != NULL)
    {
      GElf_Shdr shdr_mem;

      assert (elf_ndxscn (scn) == cnt);
      cnt++;

      char *name = elf_strptr (ebl->elf, shstrndx,
			       gelf_getshdr (scn, &shdr_mem)->sh_name);
      if (unlikely (name == NULL))
	{
	  const size_t bufsz = sizeof "[invalid sh_name 0x12345678]";
	  name = alloca (bufsz);
	  snprintf (name, bufsz, "[invalid sh_name %#" PRIx32 "]",
		    gelf_getshdr (scn, &shdr_mem)->sh_name);
	}
      scnnames[elf_ndxscn (scn)] = name;
    }

  int digits = length_map[gelf_getclass (ebl->elf) - 1][radix];

  /* We always print this prolog.  */
  printf (gettext ("\n\nSymbols from %s:\n\n"), fullname);

  /* The header line.  */
  printf (gettext ("%*s%-*s %-*s Class  Type     %-*s %*s Section\n\n"),
	  print_file_name ? (int) strlen (fullname) + 1: 0, "",
	  longest_name, sgettext ("sysv|Name"),
	  /* TRANS: the "sysv|" parts makes the string unique.  */
	  digits, sgettext ("sysv|Value"),
	  /* TRANS: the "sysv|" parts makes the string unique.  */
	  digits, sgettext ("sysv|Size"),
	  /* TRANS: the "sysv|" parts makes the string unique.  */
	  longest_where, sgettext ("sysv|Line"));

#ifdef USE_DEMANGLE
  size_t demangle_buffer_len = 0;
  char *demangle_buffer = NULL;
#endif

  /* Iterate over all symbols.  */
  for (cnt = 1; cnt < nsyms; ++cnt)
    {
      /* In this format SECTION entries are not printed.  */
      if (GELF_ST_TYPE (syms[cnt].sym.st_info) == STT_SECTION)
	continue;

      char symstrbuf[50];
      const char *symstr = sym_name (ebl->elf, strndx, syms[cnt].sym.st_name,
				     symstrbuf, sizeof symstrbuf);

#ifdef USE_DEMANGLE
      /* Demangle if necessary.  Require GNU v3 ABI by the "_Z" prefix.  */
      if (demangle && symstr[0] == '_' && symstr[1] == 'Z')
	{
	  int status = -1;
	  char *dmsymstr = __cxa_demangle (symstr, demangle_buffer,
					   &demangle_buffer_len, &status);

	  if (status == 0)
	    symstr = dmsymstr;
	}
#endif

      char symbindbuf[50];
      char symtypebuf[50];
      char secnamebuf[1024];
      char addressbuf[(64 + 2) / 3 + 1];
      char sizebuf[(64 + 2) / 3 + 1];

      /* If we have to precede the line with the file name.  */
      if (print_file_name)
	{
	  fputs_unlocked (fullname, stdout);
	  putchar_unlocked (':');
	}

      /* Covert the address.  */
      if (syms[cnt].sym.st_shndx == SHN_UNDEF)
	addressbuf[0] = sizebuf[0] = '\0';
      else
	{
	  snprintf (addressbuf, sizeof (addressbuf),
		    (radix == radix_hex ? "%0*" PRIx64
		     : (radix == radix_decimal ? "%0*" PRId64
			: "%0*" PRIo64)),
		    digits, syms[cnt].sym.st_value);
	  snprintf (sizebuf, sizeof (sizebuf),
		    (radix == radix_hex ? "%0*" PRIx64
		     : (radix == radix_decimal ? "%0*" PRId64
			: "%0*" PRIo64)),
		    digits, syms[cnt].sym.st_size);
	}

      /* Print the actual string.  */
      printf ("%-*s|%s|%-6s|%-8s|%s|%*s|%s\n",
	      longest_name, symstr, addressbuf,
	      ebl_symbol_binding_name (ebl,
				       GELF_ST_BIND (syms[cnt].sym.st_info),
				       symbindbuf, sizeof (symbindbuf)),
	      ebl_symbol_type_name (ebl, GELF_ST_TYPE (syms[cnt].sym.st_info),
				    symtypebuf, sizeof (symtypebuf)),
	      sizebuf, longest_where, syms[cnt].where,
	      ebl_section_name (ebl, syms[cnt].sym.st_shndx, syms[cnt].xndx,
				secnamebuf, sizeof (secnamebuf), scnnames,
				shnum));
    }

#ifdef USE_DEMANGLE
  free (demangle_buffer);
#endif

  if (scnnames_malloced)
    free (scnnames);
}


static char
class_type_char (Elf *elf, const GElf_Ehdr *ehdr, GElf_Sym *sym)
{
  int local_p = GELF_ST_BIND (sym->st_info) == STB_LOCAL;

  /* XXX Add support for architecture specific types and classes.  */
  if (sym->st_shndx == SHN_ABS)
    return local_p ? 'a' : 'A';

  if (sym->st_shndx == SHN_UNDEF)
    /* Undefined symbols must be global.  */
    return 'U';

  char result = "NDTSFBD         "[GELF_ST_TYPE (sym->st_info)];

  if (result == 'D')
    {
      /* Special handling: unique data symbols.  */
      if (ehdr->e_ident[EI_OSABI] == ELFOSABI_LINUX
	  && GELF_ST_BIND (sym->st_info) == STB_GNU_UNIQUE)
	result = 'u';
      else
	{
	  GElf_Shdr shdr_mem;
	  GElf_Shdr *shdr = gelf_getshdr (elf_getscn (elf, sym->st_shndx),
					  &shdr_mem);
	  if (shdr != NULL)
	    {
	      if ((shdr->sh_flags & SHF_WRITE) == 0)
		result = 'R';
	      else if (shdr->sh_type == SHT_NOBITS)
		result = 'B';
	    }
	}
    }

  return local_p ? tolower (result) : result;
}


static void
show_symbols_bsd (Elf *elf, const GElf_Ehdr *ehdr, GElf_Word strndx,
		  const char *prefix, const char *fname, const char *fullname,
		  GElf_SymX *syms, size_t nsyms)
{
  int digits = length_map[gelf_getclass (elf) - 1][radix];

  if (prefix != NULL && ! print_file_name)
    printf ("\n%s:\n", fname);

#ifdef USE_DEMANGLE
  size_t demangle_buffer_len = 0;
  char *demangle_buffer = NULL;
#endif

  /* Iterate over all symbols.  */
  for (size_t cnt = 0; cnt < nsyms; ++cnt)
    {
      char symstrbuf[50];
      const char *symstr = sym_name (elf, strndx, syms[cnt].sym.st_name,
				     symstrbuf, sizeof symstrbuf);

      /* Printing entries with a zero-length name makes the output
	 not very well parseable.  Since these entries don't carry
	 much information we leave them out.  */
      if (symstr[0] == '\0')
	continue;

      /* We do not print the entries for files.  */
      if (GELF_ST_TYPE (syms[cnt].sym.st_info) == STT_FILE)
	continue;

#ifdef USE_DEMANGLE
      /* Demangle if necessary.  Require GNU v3 ABI by the "_Z" prefix.  */
      if (demangle && symstr[0] == '_' && symstr[1] == 'Z')
	{
	  int status = -1;
	  char *dmsymstr = __cxa_demangle (symstr, demangle_buffer,
					   &demangle_buffer_len, &status);

	  if (status == 0)
	    symstr = dmsymstr;
	}
#endif

      /* If we have to precede the line with the file name.  */
      if (print_file_name)
	{
	  fputs_unlocked (fullname, stdout);
	  putchar_unlocked (':');
	}

      bool is_tls = GELF_ST_TYPE (syms[cnt].sym.st_info) == STT_TLS;
      bool is_weak = GELF_ST_BIND (syms[cnt].sym.st_info) == STB_WEAK;
      const char *marker = (mark_special
			    ? (is_tls ? "@" : (is_weak ? "*" : " ")) : "");

      if (syms[cnt].sym.st_shndx == SHN_UNDEF)
	{
	  const char *color = "";
	  if (color_mode)
	    {
	      if (is_tls)
		color = color_undef_tls;
	      else if (is_weak)
		color = color_undef_weak;
	      else
		color = color_undef;
	    }

	  printf ("%*s %sU%s %s", digits, "", color, marker, symstr);
	}
      else
	{
	  const char *color = "";
	  if (color_mode)
	    {
	      if (is_tls)
		color = color_tls;
	      else if (is_weak)
		color = color_weak;
	      else
		color = color_symbol;
	    }
	  if (print_size && syms[cnt].sym.st_size != 0)
	    {
#define HEXFMT "%6$s%2$0*1$" PRIx64 "%8$s %10$0*9$" PRIx64 " %7$s%3$c%4$s %5$s"
#define DECFMT "%6$s%2$*1$" PRId64 "%8$s %10$*9$" PRId64 " %7$s%3$c%4$s %5$s"
#define OCTFMT "%6$s%2$0*1$" PRIo64 "%8$s %10$0*9$" PRIo64 " %7$s%3$c%4$s %5$s"
	      printf ((radix == radix_hex ? HEXFMT
		       : (radix == radix_decimal ? DECFMT : OCTFMT)),
		      digits, syms[cnt].sym.st_value,
		      class_type_char (elf, ehdr, &syms[cnt].sym), marker,
		      symstr,
		      color_mode ? color_address : "",
		      color,
		      color_mode ? color_off : "",
		      digits, (uint64_t) syms[cnt].sym.st_size);
#undef HEXFMT
#undef DECFMT
#undef OCTFMT
	    }
	  else
	    {
#define HEXFMT "%6$s%2$0*1$" PRIx64 "%8$s %7$s%3$c%4$s %5$s"
#define DECFMT "%6$s%2$*1$" PRId64 "%8$s %7$s%3$c%4$s %5$s"
#define OCTFMT "%6$s%2$0*1$" PRIo64 "%8$s %7$s%3$c%4$s %5$s"
	      printf ((radix == radix_hex ? HEXFMT
		       : (radix == radix_decimal ? DECFMT : OCTFMT)),
		      digits, syms[cnt].sym.st_value,
		      class_type_char (elf, ehdr, &syms[cnt].sym), marker,
		      symstr,
		      color_mode ? color_address : "",
		      color,
		      color_mode ? color_off : "");
#undef HEXFMT
#undef DECFMT
#undef OCTFMT
	    }
	}

      if (color_mode)
	fputs_unlocked (color_off, stdout);
      putchar_unlocked ('\n');
    }

#ifdef USE_DEMANGLE
  free (demangle_buffer);
#endif
}


static void
show_symbols_posix (Elf *elf, const GElf_Ehdr *ehdr, GElf_Word strndx,
		    const char *prefix, const char *fullname, GElf_SymX *syms,
		    size_t nsyms)
{
  if (prefix != NULL && ! print_file_name)
    printf ("%s:\n", fullname);

  int digits = length_map[gelf_getclass (elf) - 1][radix];

#ifdef USE_DEMANGLE
  size_t demangle_buffer_len = 0;
  char *demangle_buffer = NULL;
#endif

  /* Iterate over all symbols.  */
  for (size_t cnt = 0; cnt < nsyms; ++cnt)
    {
      char symstrbuf[50];
      const char *symstr = sym_name (elf, strndx, syms[cnt].sym.st_name,
				     symstrbuf, sizeof symstrbuf);

      /* Printing entries with a zero-length name makes the output
	 not very well parseable.  Since these entries don't carry
	 much information we leave them out.  */
      if (symstr[0] == '\0')
	continue;

#ifdef USE_DEMANGLE
      /* Demangle if necessary.  Require GNU v3 ABI by the "_Z" prefix.  */
      if (demangle && symstr[0] == '_' && symstr[1] == 'Z')
	{
	  int status = -1;
	  char *dmsymstr = __cxa_demangle (symstr, demangle_buffer,
					   &demangle_buffer_len, &status);

	  if (status == 0)
	    symstr = dmsymstr;
	}
#endif

      /* If we have to precede the line with the file name.  */
      if (print_file_name)
	{
	  fputs_unlocked (fullname, stdout);
	  putchar_unlocked (':');
	  putchar_unlocked (' ');
	}

      printf ((radix == radix_hex
	       ? "%s %c%s %0*" PRIx64 " %0*" PRIx64 "\n"
	       : (radix == radix_decimal
		  ? "%s %c%s %*" PRId64 " %*" PRId64 "\n"
		  : "%s %c%s %0*" PRIo64 " %0*" PRIo64 "\n")),
	      symstr,
	      class_type_char (elf, ehdr, &syms[cnt].sym),
	      mark_special
	      ? (GELF_ST_TYPE (syms[cnt].sym.st_info) == STT_TLS
		 ? "@"
		 : (GELF_ST_BIND (syms[cnt].sym.st_info) == STB_WEAK
		    ? "*" : " "))
	      : "",
	      digits, syms[cnt].sym.st_value,
	      digits, syms[cnt].sym.st_size);
    }

#ifdef USE_DEMANGLE
  free (demangle_buffer);
#endif
}


/* Maximum size of memory we allocate on the stack.  */
#define MAX_STACK_ALLOC	65536

static int
sort_by_address (const void *p1, const void *p2)
{
  GElf_SymX *s1 = (GElf_SymX *) p1;
  GElf_SymX *s2 = (GElf_SymX *) p2;

  int result = (s1->sym.st_value < s2->sym.st_value
		? -1 : (s1->sym.st_value == s2->sym.st_value ? 0 : 1));

  return reverse_sort ? -result : result;
}

static Elf_Data *sort_by_name_strtab;

static int
sort_by_name (const void *p1, const void *p2)
{
  GElf_SymX *s1 = (GElf_SymX *) p1;
  GElf_SymX *s2 = (GElf_SymX *) p2;

  const char *n1 = sort_by_name_strtab->d_buf + s1->sym.st_name;
  const char *n2 = sort_by_name_strtab->d_buf + s2->sym.st_name;

  int result = strcmp (n1, n2);

  return reverse_sort ? -result : result;
}

/* Stub libdwfl callback, only the ELF handle already open is ever
   used.  Only used for finding the alternate debug file if the Dwarf
   comes from the main file.  We are not interested in separate
   debuginfo.  */
static int
find_no_debuginfo (Dwfl_Module *mod,
		   void **userdata,
		   const char *modname,
		   Dwarf_Addr base,
		   const char *file_name,
		   const char *debuglink_file,
		   GElf_Word debuglink_crc,
		   char **debuginfo_file_name)
{
  Dwarf_Addr dwbias;
  dwfl_module_info (mod, NULL, NULL, NULL, &dwbias, NULL, NULL, NULL);

  /* We are only interested if the Dwarf has been setup on the main
     elf file but is only missing the alternate debug link.  If dwbias
     hasn't even been setup, this is searching for separate debuginfo
     for the main elf.  We don't care in that case.  */
  if (dwbias == (Dwarf_Addr) -1)
    return -1;

  return dwfl_standard_find_debuginfo (mod, userdata, modname, base,
				       file_name, debuglink_file,
				       debuglink_crc, debuginfo_file_name);
}

/* Get the Dwarf for the module/file we want.  */
struct getdbg
{
  const char *name;
  Dwarf **dbg;
};

static int
getdbg_dwflmod (Dwfl_Module *dwflmod,
		void **userdata __attribute__ ((unused)),
		const char *name,
		Dwarf_Addr base __attribute__ ((unused)),
		void *arg)
{
  struct getdbg *get = (struct getdbg *) arg;
  if (get != NULL && get->name != NULL && strcmp (get->name, name) == 0)
    {
      Dwarf_Addr bias;
      *get->dbg = dwfl_module_getdwarf (dwflmod, &bias);
      return DWARF_CB_ABORT;
    }

  return DWARF_CB_OK;
}

static void
show_symbols (int fd, Ebl *ebl, GElf_Ehdr *ehdr,
	      Elf_Scn *scn, Elf_Scn *xndxscn,
	      GElf_Shdr *shdr, const char *prefix, const char *fname,
	      const char *fullname)
{
  /* Get the section header string table index.  */
  size_t shstrndx;
  if (elf_getshdrstrndx (ebl->elf, &shstrndx) < 0)
    error (EXIT_FAILURE, 0,
	   gettext ("cannot get section header string table index"));

  /* The section is that large.  */
  size_t size = shdr->sh_size;
  /* One entry is this large.  */
  size_t entsize = shdr->sh_entsize;

  /* Consistency checks.  */
  if (entsize == 0
      || entsize != gelf_fsize (ebl->elf, ELF_T_SYM, 1, EV_CURRENT))
    error (0, 0,
	   gettext ("%s: entry size in section %zd `%s' is not what we expect"),
	   fullname, elf_ndxscn (scn),
	   elf_strptr (ebl->elf, shstrndx, shdr->sh_name));
  else if (size % entsize != 0)
    error (0, 0,
	   gettext ("%s: size of section %zd `%s' is not multiple of entry size"),
	   fullname, elf_ndxscn (scn),
	   elf_strptr (ebl->elf, shstrndx, shdr->sh_name));

  /* Compute number of entries.  Handle buggy entsize values.  */
  size_t nentries = size / (entsize ?: 1);


#define obstack_chunk_alloc xmalloc
#define obstack_chunk_free free
  struct obstack whereob;
  obstack_init (&whereob);

  /* Get a DWARF debugging descriptor.  It's no problem if this isn't
     possible.  We just won't print any line number information.  */
  Dwarf *dbg = NULL;
  Dwfl *dwfl = NULL;
  if (format == format_sysv)
    {
      if (ehdr->e_type != ET_REL)
	dbg = dwarf_begin_elf (ebl->elf, DWARF_C_READ, NULL);
      else
	{
	  /* Abuse libdwfl to do the relocations for us.  This is just
	     for the ET_REL file containing Dwarf, so no need for
	     fancy lookups.  */

	  /* Duplicate an fd for dwfl_report_offline to swallow.  */
	  int dwfl_fd = dup (fd);
	  if (likely (dwfl_fd >= 0))
	    {
	      static const Dwfl_Callbacks callbacks =
		{
		  .section_address = dwfl_offline_section_address,
		  .find_debuginfo = find_no_debuginfo
		};
	      dwfl = dwfl_begin (&callbacks);
	      if (likely (dwfl != NULL))
		{
		  /* Let 0 be the logical address of the file (or
		     first in archive).  */
		  dwfl->offline_next_address = 0;
		  if (dwfl_report_offline (dwfl, fname, fname, dwfl_fd)
		      == NULL)
		    {
		      /* Consumed on success, not on failure.  */
		      close (dwfl_fd);
		    }
		  else
		    {
		      dwfl_report_end (dwfl, NULL, NULL);

		      struct getdbg get = { .name = fname, .dbg = &dbg };
		      dwfl_getmodules (dwfl, &getdbg_dwflmod, &get, 0);
		    }
		}
	    }
	}
      if (dbg != NULL)
	{
	  (void) dwarf_getpubnames (dbg, get_global, NULL, 0);

	  get_local_names (dbg);
	}
    }

  /* Get the data of the section.  */
  Elf_Data *data = elf_getdata (scn, NULL);
  Elf_Data *xndxdata = elf_getdata (xndxscn, NULL);
  if (data == NULL || (xndxscn != NULL && xndxdata == NULL))
    INTERNAL_ERROR (fullname);

  /* Allocate the memory.

     XXX We can use a dirty trick here.  Since GElf_Sym == Elf64_Sym we
     can use the data memory instead of copying again if what we read
     is a 64 bit file.  */
  if (nentries > SIZE_MAX / sizeof (GElf_SymX))
    error (EXIT_FAILURE, 0,
          gettext ("%s: entries (%zd) in section %zd `%s' is too large"),
          fullname, nentries, elf_ndxscn (scn),
          elf_strptr (ebl->elf, shstrndx, shdr->sh_name));
  GElf_SymX *sym_mem;
  if (nentries * sizeof (GElf_SymX) < MAX_STACK_ALLOC)
    sym_mem = (GElf_SymX *) alloca (nentries * sizeof (GElf_SymX));
  else
    sym_mem = (GElf_SymX *) xmalloc (nentries * sizeof (GElf_SymX));

  /* Iterate over all symbols.  */
#ifdef USE_DEMANGLE
  size_t demangle_buffer_len = 0;
  char *demangle_buffer = NULL;
#endif
  int longest_name = 4;
  int longest_where = 4;
  size_t nentries_used = 0;
  for (size_t cnt = 0; cnt < nentries; ++cnt)
    {
      GElf_Sym *sym = gelf_getsymshndx (data, xndxdata, cnt,
					&sym_mem[nentries_used].sym,
					&sym_mem[nentries_used].xndx);
      if (sym == NULL)
	INTERNAL_ERROR (fullname);

      /* Filter out administrative symbols without a name and those
	 deselected by the user with command line options.  */
      if ((hide_undefined && sym->st_shndx == SHN_UNDEF)
	  || (hide_defined && sym->st_shndx != SHN_UNDEF)
	  || (hide_local && GELF_ST_BIND (sym->st_info) == STB_LOCAL))
	continue;

      sym_mem[nentries_used].where = "";
      if (format == format_sysv)
	{
	  const char *symstr = elf_strptr (ebl->elf, shdr->sh_link,
					   sym->st_name);
	  if (symstr == NULL)
	    continue;

#ifdef USE_DEMANGLE
	  /* Demangle if necessary.  Require GNU v3 ABI by the "_Z" prefix.  */
	  if (demangle && symstr[0] == '_' && symstr[1] == 'Z')
	    {
	      int status = -1;
	      char *dmsymstr = __cxa_demangle (symstr, demangle_buffer,
					       &demangle_buffer_len, &status);

	      if (status == 0)
		symstr = dmsymstr;
	    }
#endif

	  longest_name = MAX ((size_t) longest_name, strlen (symstr));

	  if (sym->st_shndx != SHN_UNDEF
	      && GELF_ST_BIND (sym->st_info) != STB_LOCAL
	      && global_root != NULL)
	    {
	      Dwarf_Global fake = { .name = symstr };
	      Dwarf_Global **found = tfind (&fake, &global_root,
					    global_compare);
	      if (found != NULL)
		{
		  Dwarf_Die die_mem;
		  Dwarf_Die *die = dwarf_offdie (dbg, (*found)->die_offset,
						 &die_mem);

		  Dwarf_Die cudie_mem;
		  Dwarf_Die *cudie = NULL;

		  Dwarf_Addr lowpc;
		  Dwarf_Addr highpc;
		  if (die != NULL
		      && dwarf_lowpc (die, &lowpc) == 0
		      && lowpc <= sym->st_value
		      && dwarf_highpc (die, &highpc) == 0
		      && highpc > sym->st_value)
		    cudie = dwarf_offdie (dbg, (*found)->cu_offset,
					  &cudie_mem);
		  if (cudie != NULL)
		    {
		      Dwarf_Line *line = dwarf_getsrc_die (cudie,
							   sym->st_value);
		      if (line != NULL)
			{
			  /* We found the line.  */
			  int lineno;
			  (void) dwarf_lineno (line, &lineno);
			  const char *file = dwarf_linesrc (line, NULL, NULL);
			  file = (file != NULL) ? basename (file) : "???";
			  int n;
			  n = obstack_printf (&whereob, "%s:%d%c", file,
					      lineno, '\0');
			  sym_mem[nentries_used].where
			    = obstack_finish (&whereob);

			  /* The return value of obstack_print included the
			     NUL byte, so subtract one.  */
			  if (--n > (int) longest_where)
			    longest_where = (size_t) n;
			}
		    }
		}
	    }

	  /* Try to find the symbol among the local symbols.  */
	  if (sym_mem[nentries_used].where[0] == '\0')
	    {
	      struct local_name fake =
		{
		  .name = symstr,
		  .lowpc = sym->st_value,
		  .highpc = sym->st_value,
		};
	      struct local_name **found = tfind (&fake, &local_root,
						 local_compare);
	      if (found != NULL)
		{
		  /* We found the line.  */
		  int n = obstack_printf (&whereob, "%s:%" PRIu64 "%c",
					  basename ((*found)->file),
					  (*found)->lineno,
					  '\0');
		  sym_mem[nentries_used].where = obstack_finish (&whereob);

		  /* The return value of obstack_print included the
		     NUL byte, so subtract one.  */
		  if (--n > (int) longest_where)
		    longest_where = (size_t) n;
		}
	    }
	}

      /* We use this entry.  */
      ++nentries_used;
    }
#ifdef USE_DEMANGLE
  free (demangle_buffer);
#endif
  /* Now we know the exact number.  */
  nentries = nentries_used;

  /* Sort the entries according to the users wishes.  */
  if (sort == sort_name)
    {
      sort_by_name_strtab = elf_getdata (elf_getscn (ebl->elf, shdr->sh_link),
					 NULL);
      qsort (sym_mem, nentries, sizeof (GElf_SymX), sort_by_name);
    }
  else if (sort == sort_numeric)
    qsort (sym_mem, nentries, sizeof (GElf_SymX), sort_by_address);

  /* Finally print according to the users selection.  */
  switch (format)
    {
    case format_sysv:
      show_symbols_sysv (ebl, shdr->sh_link, fullname, sym_mem, nentries,
			 longest_name, longest_where);
      break;

    case format_bsd:
      show_symbols_bsd (ebl->elf, ehdr, shdr->sh_link, prefix, fname, fullname,
			sym_mem, nentries);
      break;

    case format_posix:
    default:
      assert (format == format_posix);
      show_symbols_posix (ebl->elf, ehdr, shdr->sh_link, prefix, fullname,
			  sym_mem, nentries);
      break;
    }

  /* Free all memory.  */
  if (nentries * sizeof (sym_mem[0]) >= MAX_STACK_ALLOC)
    free (sym_mem);

  obstack_free (&whereob, NULL);

  if (dbg != NULL)
    {
      tdestroy (global_root, free);
      global_root = NULL;

      tdestroy (local_root, free);
      local_root = NULL;

      if (dwfl == NULL)
	(void) dwarf_end (dbg);
    }
  if (dwfl != NULL)
    dwfl_end (dwfl);
}


static int
handle_elf (int fd, Elf *elf, const char *prefix, const char *fname,
	    const char *suffix)
{
  size_t prefix_len = prefix == NULL ? 0 : strlen (prefix);
  size_t suffix_len = suffix == NULL ? 0 : strlen (suffix);
  size_t fname_len = strlen (fname) + 1;
  char fullname[prefix_len + 1 + fname_len + suffix_len];
  char *cp = fullname;
  Elf_Scn *scn = NULL;
  int any = 0;
  int result = 0;
  GElf_Ehdr ehdr_mem;
  GElf_Ehdr *ehdr;
  Ebl *ebl;

  /* Get the backend for this object file type.  */
  ebl = ebl_openbackend (elf);

  /* We need the ELF header in a few places.  */
  ehdr = gelf_getehdr (elf, &ehdr_mem);
  if (ehdr == NULL)
    INTERNAL_ERROR (fullname);

  /* If we are asked to print the dynamic symbol table and this is
     executable or dynamic executable, fail.  */
  if (symsec_type == SHT_DYNSYM
      && ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN)
    {
      /* XXX Add machine specific object file types.  */
      error (0, 0, gettext ("%s%s%s%s: Invalid operation"),
	     prefix ?: "", prefix ? "(" : "", fname, prefix ? ")" : "");
      result = 1;
      goto out;
    }

  /* Create the full name of the file.  */
  if (prefix != NULL)
    cp = mempcpy (cp, prefix, prefix_len);
  cp = mempcpy (cp, fname, fname_len);
  if (suffix != NULL)
    memcpy (cp - 1, suffix, suffix_len + 1);

  /* Find the symbol table.

     XXX Can there be more than one?  Do we print all?  Currently we do.  */
  while ((scn = elf_nextscn (elf, scn)) != NULL)
    {
      GElf_Shdr shdr_mem;
      GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);

      if (shdr == NULL)
	INTERNAL_ERROR (fullname);

      if (shdr->sh_type == symsec_type)
	{
	  Elf_Scn *xndxscn = NULL;

	  /* We have a symbol table.  First make sure we remember this.  */
	  any = 1;

	  /* Look for an extended section index table for this section.  */
	  if (symsec_type == SHT_SYMTAB)
	    {
	      size_t scnndx = elf_ndxscn (scn);

	      while ((xndxscn = elf_nextscn (elf, xndxscn)) != NULL)
		{
		  GElf_Shdr xndxshdr_mem;
		  GElf_Shdr *xndxshdr = gelf_getshdr (xndxscn, &xndxshdr_mem);

		  if (xndxshdr == NULL)
		    INTERNAL_ERROR (fullname);

		  if (xndxshdr->sh_type == SHT_SYMTAB_SHNDX
		      && xndxshdr->sh_link == scnndx)
		    break;
		}
	    }

	  show_symbols (fd, ebl, ehdr, scn, xndxscn, shdr, prefix, fname,
			fullname);
	}
    }

  if (! any)
    {
      error (0, 0, gettext ("%s%s%s: no symbols"),
	     prefix ?: "", prefix ? ":" : "", fname);
      result = 1;
    }

 out:
  /* Close the ELF backend library descriptor.  */
  ebl_closebackend (ebl);

  return result;
}


#include "debugpred.h"
