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//===========================================================================

//

//      strchr.cxx

//

//      ANSI standard strchr() routine

//

//===========================================================================

//####ECOSGPLCOPYRIGHTBEGIN####

// -------------------------------------------

// This file is part of eCos, the Embedded Configurable Operating System.

// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.

//

// eCos is free software; you can redistribute it and/or modify it under

// the terms of the GNU General Public License as published by the Free

// Software Foundation; either version 2 or (at your option) any later version.

//

// eCos is distributed in the hope that it will be useful, but WITHOUT ANY

// WARRANTY; without even the implied warranty of MERCHANTABILITY or

// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

// for more details.

//

// You should have received a copy of the GNU General Public License along

// with eCos; if not, write to the Free Software Foundation, Inc.,

// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.

//

// As a special exception, if other files instantiate templates or use macros

// or inline functions from this file, or you compile this file and link it

// with other works to produce a work based on this file, this file does not

// by itself cause the resulting work to be covered by the GNU General Public

// License. However the source code for this file must still be made available

// in accordance with section (3) of the GNU General Public License.

//

// This exception does not invalidate any other reasons why a work based on

// this file might be covered by the GNU General Public License.

//

// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.

// at http://sources.redhat.com/ecos/ecos-license/

// -------------------------------------------

//####ECOSGPLCOPYRIGHTEND####

//===========================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):    jlarmour

// Contributors:  

// Date:         2000-04-14

// Purpose:     

// Description: 

// Usage:       

//

//####DESCRIPTIONEND####

//

//===========================================================================

// CONFIGURATION

#include <pkgconf/libc_string.h>   // Configuration header

// INCLUDES

#include <cyg/infra/cyg_type.h>    // Common type definitions

#include <cyg/infra/cyg_trac.h>    // Tracing support

#include <cyg/infra/cyg_ass.h>     // Assertion support

#include <string.h>                // Header for this file

#include <stddef.h>         // Compiler definitions such as size_t, NULL etc.

#include <cyg/libc/string/stringsupp.hxx> // Useful string function support and

                                          // prototypes

// EXPORTED SYMBOLS

externC char *

strchr( const char *s, int c ) CYGBLD_ATTRIB_WEAK_ALIAS(__strchr);

// MACROS

// DETECTCHAR returns nonzero if X contains the byte used 

// to fill MASK.

#define DETECTCHAR(X,MASK) (CYG_LIBC_STR_DETECTNULL( (X) ^ (MASK) ))

// FUNCTIONS

char *

__strchr( const char *s, int c )

{

    CYG_REPORT_FUNCNAMETYPE( "__strchr", "returning %08x" );

    CYG_REPORT_FUNCARG2( "s=%08x, c=%d", s, c );

    CYG_CHECK_DATA_PTR( s, "s is not a valid pointer!" );

#if defined(CYGIMP_LIBC_STRING_PREFER_SMALL_TO_FAST) || defined(__OPTIMIZE_SIZE__)

    char charc = c;

    while (*s && *s != charc)

    {

        s++;

    }

    if (*s != charc)

    {

        s = NULL;

    }

    CYG_REPORT_RETVAL( s );

    return (char *) s;

#else

    char charc = c;

    CYG_WORD mask;

    CYG_WORD j;

    CYG_WORD *aligned_addr;

    if (CYG_LIBC_STR_UNALIGNED (s))

    {

        while (*s && *s != charc)

            s++;

        if (*s != charc)

            s = NULL;

        CYG_REPORT_RETVAL( s );

        return (char *) s;

    }

    for (j = 0, mask = 0; j < sizeof(mask); j++)

        mask = (mask << 8) + charc;

    aligned_addr = (CYG_WORD *)s;

    while (!CYG_LIBC_STR_DETECTNULL (*aligned_addr) &&

           !DETECTCHAR (*aligned_addr, mask))

        aligned_addr++;

    // The block of bytes currently pointed to by aligned_addr

    // contains either a null or the target char, or both.  We

    // catch it using the bytewise search.

    s = (char *)aligned_addr;

    while (*s && *s != charc)

        s++;

    if (*s != charc)

        s = NULL;

    CYG_REPORT_RETVAL( s );

    return (char *)s;

#endif // not defined(CYGIMP_LIBC_STRING_PREFER_SMALL_TO_FAST) ||

       //     defined(__OPTIMIZE_SIZE__)

} // __strchr()

// EOF strchr.cxx