usr/src/tools/ctf/common/symbol.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28
  29 #include <sys/types.h>
  30 #include <string.h>
  31
  32 #include "symbol.h"
  33
  34 int
  35 ignore_symbol(GElf_Sym *sym, const char *name)
  36 {
  37         uchar_t type = GELF_ST_TYPE(sym->st_info);
  38
  39         /*
  40          * As an optimization, we do not output function or data object
  41          * records for undefined or anonymous symbols.
  42          */
  43         if (sym->st_shndx == SHN_UNDEF || sym->st_name == 0)
  44                 return (1);
  45
  46         /*
  47          * _START_ and _END_ are added to the symbol table by the
  48          * linker, and will never have associated type information.
  49          */
  50         if (strcmp(name, "_START_") == 0 || strcmp(name, "_END_") == 0)
  51                 return (1);
  52
  53         /*
  54          * Do not output records for absolute-valued object symbols
  55          * that have value zero.  The compiler insists on generating
  56          * things like this for __fsr_init_value settings, etc.
  57          */
  58         if (type == STT_OBJECT && sym->st_shndx == SHN_ABS &&
  59             sym->st_value == 0)
  60                 return (1);
  61         return (0);
  62 }