Line data    Source code

       1             : /* Create new COMMON symbol.
       2             :    Copyright (C) 2002, 2016 Red Hat, Inc.
       3             :    This file is part of elfutils.
       4             :    Written by Ulrich Drepper <drepper@redhat.com>, 2002.
       5             : 
       6             :    This file is free software; you can redistribute it and/or modify
       7             :    it under the terms of either
       8             : 
       9             :      * the GNU Lesser General Public License as published by the Free
      10             :        Software Foundation; either version 3 of the License, or (at
      11             :        your option) any later version
      12             : 
      13             :    or
      14             : 
      15             :      * the GNU General Public License as published by the Free
      16             :        Software Foundation; either version 2 of the License, or (at
      17             :        your option) any later version
      18             : 
      19             :    or both in parallel, as here.
      20             : 
      21             :    elfutils is distributed in the hope that it will be useful, but
      22             :    WITHOUT ANY WARRANTY; without even the implied warranty of
      23             :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      24             :    General Public License for more details.
      25             : 
      26             :    You should have received copies of the GNU General Public License and
      27             :    the GNU Lesser General Public License along with this program.  If
      28             :    not, see <http://www.gnu.org/licenses/>.  */
      29             : 
      30             : #ifdef HAVE_CONFIG_H
      31             : # include <config.h>
      32             : #endif
      33             : 
      34             : #include <inttypes.h>
      35             : #include <stdio.h>
      36             : #include <stdlib.h>
      37             : #include <string.h>
      38             : 
      39             : #include <libasmP.h>
      40             : #include <system.h>
      41             : 
      42             : 
      43             : /* Object for special COMMON section.  */
      44             : static const AsmScn_t __libasm_com_scn =
      45             :   {
      46             :     .data = {
      47             :       .main = {
      48             :         .scn = ASM_COM_SCN
      49             :       }
      50             :     }
      51             :   };
      52             : 
      53             : 
      54             : AsmSym_t *
      55           1 : asm_newcomsym (AsmCtx_t *ctx, const char *name, GElf_Xword size,
      56             :                GElf_Addr align)
      57             : {
      58             :   AsmSym_t *result;
      59             : 
      60           1 :   if (ctx == NULL)
      61             :     /* Something went wrong before.  */
      62             :     return NULL;
      63             : 
      64             :   /* Common symbols are public.  Therefore the user must provide a
      65             :      name.  */
      66           1 :   if (name == NULL)
      67             :     {
      68           0 :       __libasm_seterrno (ASM_E_INVALID);
      69           0 :       return NULL;
      70             :     }
      71             : 
      72             :   rwlock_wrlock (ctx->lock);
      73             : 
      74           1 :   result = (AsmSym_t *) malloc (sizeof (AsmSym_t));
      75           1 :   if (result == NULL)
      76             :     return NULL;
      77             : 
      78           1 :   result->scn = (AsmScn_t *) &__libasm_com_scn;
      79           1 :   result->size = size;
      80             :   /* XXX Do we have to allow a different type?  */
      81           1 :   result->type = STT_OBJECT;
      82             :   /* XXX Do we have to allow a different binding?  */
      83           1 :   result->binding = STB_GLOBAL;
      84           1 :   result->symidx = 0;
      85           1 :   result->strent = dwelf_strtab_add (ctx->symbol_strtab, name);
      86             : 
      87             :   /* The value of a COM symbol is the alignment.  Since there are no
      88             :      subsection and the initial offset of the section is 0 we can get
      89             :      the alignment recorded by storing it into the offset field.  */
      90           1 :   result->offset = align;
      91             : 
      92           1 :   if (unlikely (ctx->textp))
      93           0 :     fprintf (ctx->out.file, "\t.comm %s, %" PRIuMAX ", %" PRIuMAX "\n",
      94             :              name, (uintmax_t) size, (uintmax_t) align);
      95             :   else
      96             :     {
      97             :       /* Put the symbol in the hash table so that we can later find it.  */
      98           1 :       if (asm_symbol_tab_insert (&ctx->symbol_tab, elf_hash (name), result)
      99             :           != 0)
     100             :         {
     101             :           /* The symbol already exists.  */
     102           0 :           __libasm_seterrno (ASM_E_DUPLSYM);
     103           0 :           free (result);
     104           0 :           result = NULL;
     105             :         }
     106           1 :       else if (name != NULL && asm_emit_symbol_p (name))
     107             :         /* Only count non-private symbols.  */
     108           1 :         ++ctx->nsymbol_tab;
     109             :     }
     110             : 
     111             :   rwlock_unlock (ctx->lock);
     112             : 
     113             :   return result;
     114             : }