e385b1074b
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@2362 42af7a65-404d-4744-a932-0658087f49c3
122 lines
4.6 KiB
C
122 lines
4.6 KiB
C
/****************************************************************************
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* binfmt/symtab_findbyvalue.c
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*
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* Copyright (C) 2009 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <stddef.h>
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#include <debug.h>
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#include <assert.h>
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#include <errno.h>
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#include <nuttx/symtab.h>
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/****************************************************************************
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* Pre-processor Definitions
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****************************************************************************/
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/****************************************************************************
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* Private Function Prototypes
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****************************************************************************/
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/****************************************************************************
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* Private Data
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****************************************************************************/
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/****************************************************************************
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* Private Functions
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****************************************************************************/
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/***********************************************************************
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* Public Functions
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***********************************************************************/
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/****************************************************************************
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* Name: symtab_findbyvalue
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*
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* Description:
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* Find the symbol in the symbol table whose value closest (but not greater
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* than), the provided value. This version assumes that table is not ordered
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* with respect to symbol name and, hence, access time will be linear with
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* respect to nsyms.
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*
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* Returned Value:
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* A reference to the symbol table entry if an entry with the matching
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* name is found; NULL is returned if the entry is not found.
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*
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****************************************************************************/
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FAR const struct symtab_s *
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symtab_findbyvalue(FAR const struct symtab_s *symtab,
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FAR void *value, int nsyms)
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{
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FAR const struct symtab_s *retval = NULL;
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DEBUGASSERT(symtab != NULL);
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for (; nsyms > 0; symtab++, nsyms--)
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{
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/* Look for symbols of lesser or equal value (probably address) to value */
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if (symtab->sym_value <= value)
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{
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/* Found one. Is it the largest we have found so far? */
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if (!retval || symtab->sym_value > retval->sym_value)
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{
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/* Yes, then it is the new candidate for the symbol whose value
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* just below 'value'
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*/
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retval = symtab;
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/* If it is exactly equal to the search 'value', then we might as
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* well terminate early because we can't do any better than that.
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*/
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if (retval->sym_value == value)
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{
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break;
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}
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}
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}
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}
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return retval;
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}
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