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author | patacongo <patacongo@7fd9a85b-ad96-42d3-883c-3090e2eb8679> | 2011-12-19 19:24:09 +0000 |
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committer | patacongo <patacongo@7fd9a85b-ad96-42d3-883c-3090e2eb8679> | 2011-12-19 19:24:09 +0000 |
commit | add995c32e86f9de8fa8fc05172435332c25a895 (patch) | |
tree | 0191fde92a5c4dcd55a24b2aa760fa4c88713242 /nuttx/binfmt/symtab_findbyvalue.c | |
download | px4-firmware-add995c32e86f9de8fa8fc05172435332c25a895.tar.gz px4-firmware-add995c32e86f9de8fa8fc05172435332c25a895.tar.bz2 px4-firmware-add995c32e86f9de8fa8fc05172435332c25a895.zip |
Completes coding of the PWM module
git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@4200 7fd9a85b-ad96-42d3-883c-3090e2eb8679
Diffstat (limited to 'nuttx/binfmt/symtab_findbyvalue.c')
-rw-r--r-- | nuttx/binfmt/symtab_findbyvalue.c | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/nuttx/binfmt/symtab_findbyvalue.c b/nuttx/binfmt/symtab_findbyvalue.c new file mode 100644 index 000000000..80df74668 --- /dev/null +++ b/nuttx/binfmt/symtab_findbyvalue.c @@ -0,0 +1,121 @@ +/**************************************************************************** + * binfmt/symtab_findbyvalue.c + * + * Copyright (C) 2009 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <spudmonkey@racsa.co.cr> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name NuttX nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> + +#include <stddef.h> +#include <debug.h> +#include <assert.h> +#include <errno.h> + +#include <nuttx/symtab.h> + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Function Prototypes + ****************************************************************************/ + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/*********************************************************************** + * Public Functions + ***********************************************************************/ + +/**************************************************************************** + * Name: symtab_findbyvalue + * + * Description: + * Find the symbol in the symbol table whose value closest (but not greater + * than), the provided value. This version assumes that table is not ordered + * with respect to symbol name and, hence, access time will be linear with + * respect to nsyms. + * + * Returned Value: + * A reference to the symbol table entry if an entry with the matching + * name is found; NULL is returned if the entry is not found. + * + ****************************************************************************/ + +FAR const struct symtab_s * +symtab_findbyvalue(FAR const struct symtab_s *symtab, + FAR void *value, int nsyms) +{ + FAR const struct symtab_s *retval = NULL; + + DEBUGASSERT(symtab != NULL); + for (; nsyms > 0; symtab++, nsyms--) + { + /* Look for symbols of lesser or equal value (probably address) to value */ + + if (symtab->sym_value <= value) + { + /* Found one. Is it the largest we have found so far? */ + + if (!retval || symtab->sym_value > retval->sym_value) + { + /* Yes, then it is the new candidate for the symbol whose value + * just below 'value' + */ + + retval = symtab; + + /* If it is exactly equal to the search 'value', then we might as + * well terminate early because we can't do any better than that. + */ + + if (retval->sym_value == value) + { + break; + } + } + } + } + + return retval; +} + |