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      1 /* Create new COMMON symbol.
      2    Copyright (C) 2002 Red Hat, Inc.
      3    This file is part of elfutils.
      4    Written by Ulrich Drepper <drepper (at) 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 asm_newcomsym (ctx, name, size, align)
     56      AsmCtx_t *ctx;
     57      const char *name;
     58      GElf_Xword size;
     59      GElf_Addr align;
     60 {
     61   AsmSym_t *result;
     62 
     63   if (ctx == NULL)
     64     /* Something went wrong before.  */
     65     return NULL;
     66 
     67   /* Common symbols are public.  Therefore the user must provide a
     68      name.  */
     69   if (name == NULL)
     70     {
     71       __libasm_seterrno (ASM_E_INVALID);
     72       return NULL;
     73     }
     74 
     75   rwlock_wrlock (ctx->lock);
     76 
     77   result = (AsmSym_t *) malloc (sizeof (AsmSym_t));
     78   if (result == NULL)
     79     return NULL;
     80 
     81   result->scn = (AsmScn_t *) &__libasm_com_scn;
     82   result->size = size;
     83   /* XXX Do we have to allow a different type?  */
     84   result->type = STT_OBJECT;
     85   /* XXX Do we have to allow a different binding?  */
     86   result->binding = STB_GLOBAL;
     87   result->symidx = 0;
     88   result->strent = ebl_strtabadd (ctx->symbol_strtab, name, 0);
     89 
     90   /* The value of a COM symbol is the alignment.  Since there are no
     91      subsection and the initial offset of the section is 0 we can get
     92      the alignment recorded by storing it into the offset field.  */
     93   result->offset = align;
     94 
     95   if (unlikely (ctx->textp))
     96     fprintf (ctx->out.file, "\t.comm %s, %" PRIuMAX ", %" PRIuMAX "\n",
     97 	     name, (uintmax_t) size, (uintmax_t) align);
     98   else
     99     {
    100       /* Put the symbol in the hash table so that we can later find it.  */
    101       if (asm_symbol_tab_insert (&ctx->symbol_tab, elf_hash (name), result)
    102 	  != 0)
    103 	{
    104 	  /* The symbol already exists.  */
    105 	  __libasm_seterrno (ASM_E_DUPLSYM);
    106 	  free (result);
    107 	  result = NULL;
    108 	}
    109       else if (name != NULL && asm_emit_symbol_p (name))
    110 	/* Only count non-private symbols.  */
    111 	++ctx->nsymbol_tab;
    112     }
    113 
    114   rwlock_unlock (ctx->lock);
    115 
    116   return result;
    117 }
    118