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      1 /* Retrieve ELF descriptor used for DWARF access.
      2    Copyright (C) 2002, 2003, 2004, 2005 Red Hat, Inc.
      3    This file is part of Red Hat elfutils.
      4    Written by Ulrich Drepper <drepper (at) redhat.com>, 2002.
      5 
      6    Red Hat elfutils is free software; you can redistribute it and/or modify
      7    it under the terms of the GNU General Public License as published by the
      8    Free Software Foundation; version 2 of the License.
      9 
     10    Red Hat elfutils is distributed in the hope that it will be useful, but
     11    WITHOUT ANY WARRANTY; without even the implied warranty of
     12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     13    General Public License for more details.
     14 
     15    You should have received a copy of the GNU General Public License along
     16    with Red Hat elfutils; if not, write to the Free Software Foundation,
     17    Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
     18 
     19    In addition, as a special exception, Red Hat, Inc. gives You the
     20    additional right to link the code of Red Hat elfutils with code licensed
     21    under any Open Source Initiative certified open source license
     22    (http://www.opensource.org/licenses/index.php) which requires the
     23    distribution of source code with any binary distribution and to
     24    distribute linked combinations of the two.  Non-GPL Code permitted under
     25    this exception must only link to the code of Red Hat elfutils through
     26    those well defined interfaces identified in the file named EXCEPTION
     27    found in the source code files (the "Approved Interfaces").  The files
     28    of Non-GPL Code may instantiate templates or use macros or inline
     29    functions from the Approved Interfaces without causing the resulting
     30    work to be covered by the GNU General Public License.  Only Red Hat,
     31    Inc. may make changes or additions to the list of Approved Interfaces.
     32    Red Hat's grant of this exception is conditioned upon your not adding
     33    any new exceptions.  If you wish to add a new Approved Interface or
     34    exception, please contact Red Hat.  You must obey the GNU General Public
     35    License in all respects for all of the Red Hat elfutils code and other
     36    code used in conjunction with Red Hat elfutils except the Non-GPL Code
     37    covered by this exception.  If you modify this file, you may extend this
     38    exception to your version of the file, but you are not obligated to do
     39    so.  If you do not wish to provide this exception without modification,
     40    you must delete this exception statement from your version and license
     41    this file solely under the GPL without exception.
     42 
     43    Red Hat elfutils is an included package of the Open Invention Network.
     44    An included package of the Open Invention Network is a package for which
     45    Open Invention Network licensees cross-license their patents.  No patent
     46    license is granted, either expressly or impliedly, by designation as an
     47    included package.  Should you wish to participate in the Open Invention
     48    Network licensing program, please visit www.openinventionnetwork.com
     49    <http://www.openinventionnetwork.com>.  */
     50 
     51 #ifdef HAVE_CONFIG_H
     52 # include <config.h>
     53 #endif
     54 
     55 #include <assert.h>
     56 #include <stddef.h>
     57 
     58 #include "libdwP.h"
     59 
     60 
     61 #ifdef USE_TLS
     62 /* The error number.  */
     63 static __thread int global_error;
     64 #else
     65 /* This is the key for the thread specific memory.  */
     66 static tls_key_t key;
     67 
     68 /* The error number.  Used in non-threaded programs.  */
     69 static int global_error;
     70 static bool threaded;
     71 /* We need to initialize the thread-specific data.  */
     72 once_define (static, once);
     73 
     74 /* The initialization and destruction functions.  */
     75 static void init (void);
     76 static void free_key_mem (void *mem);
     77 #endif	/* TLS */
     78 
     79 
     80 int
     81 dwarf_errno (void)
     82 {
     83   int result;
     84 
     85 #ifndef USE_TLS
     86   /* If we have not yet initialized the buffer do it now.  */
     87   once_execute (once, init);
     88 
     89   if (threaded)
     90     {
     91     /* We do not allocate memory for the data.  It is only a word.
     92        We can store it in place of the pointer.  */
     93       result = (intptr_t) getspecific (key);
     94 
     95       setspecific (key, (void *) (intptr_t) DWARF_E_NOERROR);
     96       return result;
     97     }
     98 #endif	/* TLS */
     99 
    100   result = global_error;
    101   global_error = DWARF_E_NOERROR;
    102   return result;
    103 }
    104 INTDEF(dwarf_errno)
    105 
    106 
    107 /* XXX For now we use string pointers.  Once the table stablelizes
    108    make it more DSO-friendly.  */
    109 static const char *errmsgs[] =
    110   {
    111     [DWARF_E_NOERROR] = N_("no error"),
    112     [DWARF_E_UNKNOWN_ERROR] = N_("unknown error"),
    113     [DWARF_E_INVALID_ACCESS] = N_("invalid access"),
    114     [DWARF_E_NO_REGFILE] = N_("no regular file"),
    115     [DWARF_E_IO_ERROR] = N_("I/O error"),
    116     [DWARF_E_INVALID_ELF] = N_("invalid ELF file"),
    117     [DWARF_E_NO_DWARF] = N_("no DWARF information"),
    118     [DWARF_E_NOELF] = N_("no ELF file"),
    119     [DWARF_E_GETEHDR_ERROR] = N_("cannot get ELF header"),
    120     [DWARF_E_NOMEM] = N_("out of memory"),
    121     [DWARF_E_UNIMPL] = N_("not implemented"),
    122     [DWARF_E_INVALID_CMD] = N_("invalid command"),
    123     [DWARF_E_INVALID_VERSION] = N_("invalid version"),
    124     [DWARF_E_INVALID_FILE] = N_("invalid file"),
    125     [DWARF_E_NO_ENTRY] = N_("no entries found"),
    126     [DWARF_E_INVALID_DWARF] = N_("invalid DWARF"),
    127     [DWARF_E_NO_STRING] = N_("no string data"),
    128     [DWARF_E_NO_ADDR] = N_("no address value"),
    129     [DWARF_E_NO_CONSTANT] = N_("no constant value"),
    130     [DWARF_E_NO_REFERENCE] = N_("no reference value"),
    131     [DWARF_E_INVALID_REFERENCE] = N_("invalid reference value"),
    132     [DWARF_E_NO_DEBUG_LINE] = N_(".debug_line section missing"),
    133     [DWARF_E_INVALID_DEBUG_LINE] = N_("invalid .debug_line section"),
    134     [DWARF_E_TOO_BIG] = N_("debug information too big"),
    135     [DWARF_E_VERSION] = N_("invalid DWARF version"),
    136     [DWARF_E_INVALID_DIR_IDX] = N_("invalid directory index"),
    137     [DWARF_E_ADDR_OUTOFRANGE] = N_("address out of range"),
    138     [DWARF_E_NO_LOCLIST] = N_("no location list value"),
    139     [DWARF_E_NO_BLOCK] = N_("no block data"),
    140     [DWARF_E_INVALID_LINE_IDX] = N_("invalid line index"),
    141     [DWARF_E_INVALID_ARANGE_IDX] = N_("invalid address range index"),
    142     [DWARF_E_NO_MATCH] = N_("no matching address range"),
    143     [DWARF_E_NO_FLAG] = N_("no flag value"),
    144     [DWARF_E_INVALID_OFFSET] = N_("invalid offset"),
    145     [DWARF_E_NO_DEBUG_RANGES] = N_(".debug_ranges section missing"),
    146   };
    147 #define nerrmsgs (sizeof (errmsgs) / sizeof (errmsgs[0]))
    148 
    149 
    150 void
    151 __libdw_seterrno (value)
    152      int value;
    153 {
    154 #ifndef USE_TLS
    155   /* If we have not yet initialized the buffer do it now.  */
    156   once_execute (once, init);
    157 
    158   if (threaded)
    159     /* We do not allocate memory for the data.  It is only a word.
    160        We can store it in place of the pointer.  */
    161     setspecific (key, (void *) (intptr_t) value);
    162 #endif	/* TLS */
    163 
    164   global_error = (value >= 0 && value < (int) nerrmsgs
    165 		  ? value : DWARF_E_UNKNOWN_ERROR);
    166 }
    167 
    168 
    169 const char *
    170 dwarf_errmsg (error)
    171      int error;
    172 {
    173   int last_error;
    174 
    175 #ifndef USE_TLS
    176   /* If we have not yet initialized the buffer do it now.  */
    177   once_execute (once, init);
    178 
    179   if ((error == 0 || error == -1) && threaded)
    180     /* We do not allocate memory for the data.  It is only a word.
    181        We can store it in place of the pointer.  */
    182     last_error = (intptr_t) getspecific (key);
    183   else
    184 #endif	/* TLS */
    185     last_error = global_error;
    186 
    187   if (error == 0)
    188     return last_error != 0 ? _(errmsgs[last_error]) : NULL;
    189   else if (error < -1 || error >= (int) nerrmsgs)
    190     return _(errmsgs[DWARF_E_UNKNOWN_ERROR]);
    191 
    192   return _(errmsgs[error == -1 ? last_error : error]);
    193 }
    194 INTDEF(dwarf_errmsg)
    195 
    196 
    197 #ifndef USE_TLS
    198 /* Free the thread specific data, this is done if a thread terminates.  */
    199 static void
    200 free_key_mem (void *mem __attribute__ ((unused)))
    201 {
    202   setspecific (key, NULL);
    203 }
    204 
    205 
    206 /* Initialize the key for the global variable.  */
    207 static void
    208 init (void)
    209 {
    210   // XXX Screw you, gcc4, the unused function attribute does not work.
    211   __asm ("" :: "r" (free_key_mem));
    212 
    213   if (key_create (&key, free_key_mem) == 0)
    214     /* Creating the key succeeded.  */
    215     threaded = true;
    216 }
    217 #endif	/* TLS */
    218