157 lines
		
	
	
		
			4.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			157 lines
		
	
	
		
			4.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*************************************************
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| *      Perl-Compatible Regular Expressions       *
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| *************************************************/
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| 
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| /* PCRE is a library of functions to support regular expressions whose syntax
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| and semantics are as close as possible to those of the Perl 5 language.
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| 
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|                        Written by Philip Hazel
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|            Copyright (c) 1997-2012 University of Cambridge
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| 
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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 are met:
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| 
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|     * Redistributions of source code must retain the above copyright notice,
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|       this list of conditions and the following disclaimer.
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| 
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|     * Redistributions in binary form must reproduce the above copyright
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|       notice, this list of conditions and the following disclaimer in the
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|       documentation and/or other materials provided with the distribution.
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| 
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|     * Neither the name of the University of Cambridge nor the names of its
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|       contributors may be used to endorse or promote products derived from
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|       this software without specific prior written permission.
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| 
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| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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| AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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| IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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| ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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| LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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| CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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| SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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| INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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| CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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| ARISING IN 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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| 
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| /* This module contains an internal function for validating UTF-16 character
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| strings. */
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| 
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| 
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| #ifdef HAVE_CONFIG_H
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| #include "config.h"
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| #endif
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| 
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| /* Generate code with 16 bit character support. */
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| #define COMPILE_PCRE16
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| 
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| #include "pcre_internal.h"
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| 
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| 
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| /*************************************************
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| *         Validate a UTF-16 string                *
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| *************************************************/
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| 
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| /* This function is called (optionally) at the start of compile or match, to
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| check that a supposed UTF-16 string is actually valid. The early check means
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| that subsequent code can assume it is dealing with a valid string. The check
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| can be turned off for maximum performance, but the consequences of supplying an
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| invalid string are then undefined.
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| 
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| From release 8.21 more information about the details of the error are passed
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| back in the returned value:
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| 
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| PCRE_UTF16_ERR0  No error
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| PCRE_UTF16_ERR1  Missing low surrogate at the end of the string
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| PCRE_UTF16_ERR2  Invalid low surrogate
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| PCRE_UTF16_ERR3  Isolated low surrogate
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| PCRE_UTF16_ERR4  Non-character
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| 
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| Arguments:
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|   string       points to the string
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|   length       length of string, or -1 if the string is zero-terminated
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|   errp         pointer to an error position offset variable
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| 
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| Returns:       = 0    if the string is a valid UTF-16 string
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|                > 0    otherwise, setting the offset of the bad character
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| */
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| 
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| int
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| PRIV(valid_utf)(PCRE_PUCHAR string, int length, int *erroroffset)
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| {
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| #ifdef SUPPORT_UTF
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| register PCRE_PUCHAR p;
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| register pcre_uint32 c;
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| 
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| if (length < 0)
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|   {
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|   for (p = string; *p != 0; p++);
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|   length = p - string;
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|   }
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| 
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| for (p = string; length-- > 0; p++)
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|   {
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|   c = *p;
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| 
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|   if ((c & 0xf800) != 0xd800)
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|     {
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|     /* Normal UTF-16 code point. Neither high nor low surrogate. */
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| 
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|     /* Check for non-characters */
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|     if ((c & 0xfffeu) == 0xfffeu || (c >= 0xfdd0u && c <= 0xfdefu))
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|       {
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|       *erroroffset = p - string;
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|       return PCRE_UTF16_ERR4;
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|       }
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|     }
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|   else if ((c & 0x0400) == 0)
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|     {
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|     /* High surrogate. */
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| 
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|     /* Must be a followed by a low surrogate. */
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|     if (length == 0)
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|       {
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|       *erroroffset = p - string;
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|       return PCRE_UTF16_ERR1;
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|       }
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|     p++;
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|     length--;
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|     if ((*p & 0xfc00) != 0xdc00)
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|       {
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|       *erroroffset = p - string;
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|       return PCRE_UTF16_ERR2;
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|       }
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|     else
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|       {
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|       /* Valid surrogate, but check for non-characters */
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|       c = (((c & 0x3ffu) << 10) | (*p & 0x3ffu)) + 0x10000u;
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|       if ((c & 0xfffeu) == 0xfffeu)
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|         {
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|         *erroroffset = p - string;
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|         return PCRE_UTF16_ERR4;
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|         }
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|       }
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|     }
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|   else
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|     {
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|     /* Isolated low surrogate. Always an error. */
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|     *erroroffset = p - string;
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|     return PCRE_UTF16_ERR3;
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|     }
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|   }
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| 
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| #else  /* SUPPORT_UTF */
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| (void)(string);  /* Keep picky compilers happy */
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| (void)(length);
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| (void)(erroroffset);
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| #endif /* SUPPORT_UTF */
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| 
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| return PCRE_UTF16_ERR0;   /* This indicates success */
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| }
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| 
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| /* End of pcre16_valid_utf16.c */
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