code/trunk/pcre_byte_order.c

/*************************************************
*      Perl-Compatible Regular Expressions       *
*************************************************/

/* PCRE is a library of functions to support regular expressions whose syntax
and semantics are as close as possible to those of the Perl 5 language.

                       Written by Philip Hazel
           Copyright (c) 1997-2009 University of Cambridge

-----------------------------------------------------------------------------
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice,
      this list of conditions and the following disclaimer.

    * 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.

    * Neither the name of the University of Cambridge 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.
-----------------------------------------------------------------------------
*/


/* This module contains an internal function that tests a compiled pattern to
see if it was compiled with the opposite endianness. If so, it uses an
auxiliary local function to flip the appropriate bytes. */


#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "pcre_internal.h"


/*************************************************
*         Flip bytes in an integer               *
*************************************************/

/* This function is called when the magic number in a regex doesn't match, in
order to flip its bytes to see if we are dealing with a pattern that was
compiled on a host of different endianness. If so, this function is used to
flip other byte values.

Arguments:
  value        the number to flip
  n            the number of bytes to flip (assumed to be 2 or 4)

Returns:       the flipped value
*/

static unsigned long int
byteflip(unsigned long int value, int n)
{
if (n == 2) return ((value & 0x00ff) << 8) | ((value & 0xff00) >> 8);
return ((value & 0x000000ff) << 24) |
       ((value & 0x0000ff00) <<  8) |
       ((value & 0x00ff0000) >>  8) |
       ((value & 0xff000000) >> 24);
}


/*************************************************
*       Test for a byte-flipped compiled regex   *
*************************************************/

/* This function is called from pcre_exec(), pcre_dfa_exec(), and also from
pcre_fullinfo(). Its job is to test whether the regex is byte-flipped - that
is, it was compiled on a system of opposite endianness. The function is called
only when the native MAGIC_NUMBER test fails. If the regex is indeed flipped,
we flip all the relevant values into a different data block, and return it.

Arguments:
  re               points to the regex
  study            points to study data, or NULL
  internal_re      points to a new regex block
  internal_study   points to a new study block

Returns:           the new block if is is indeed a byte-flipped regex
                   NULL if it is not
*/

real_pcre *
PRIV(try_flipped)(const real_pcre *re, real_pcre *internal_re,
  const pcre_study_data *study, pcre_study_data *internal_study)
{
if (byteflip(re->magic_number, sizeof(re->magic_number)) != MAGIC_NUMBER)
  return NULL;

*internal_re = *re;           /* To copy other fields */
internal_re->size = byteflip(re->size, sizeof(re->size));
internal_re->options = byteflip(re->options, sizeof(re->options));
internal_re->flags = (pcre_uint16)byteflip(re->flags, sizeof(re->flags));
internal_re->top_bracket =
  (pcre_uint16)byteflip(re->top_bracket, sizeof(re->top_bracket));
internal_re->top_backref =
  (pcre_uint16)byteflip(re->top_backref, sizeof(re->top_backref));
internal_re->first_char =
  (pcre_uint16)byteflip(re->first_char, sizeof(re->first_char));
internal_re->req_char =
  (pcre_uint16)byteflip(re->req_char, sizeof(re->req_char));
internal_re->name_table_offset =
  (pcre_uint16)byteflip(re->name_table_offset, sizeof(re->name_table_offset));
internal_re->name_entry_size =
  (pcre_uint16)byteflip(re->name_entry_size, sizeof(re->name_entry_size));
internal_re->name_count =
  (pcre_uint16)byteflip(re->name_count, sizeof(re->name_count));

if (study != NULL)
  {
  *internal_study = *study;   /* To copy other fields */
  internal_study->size = byteflip(study->size, sizeof(study->size));
  internal_study->flags = byteflip(study->flags, sizeof(study->flags));
  internal_study->minlength = byteflip(study->minlength,
    sizeof(study->minlength));
  }

return internal_re;
}

/* End of pcre_tryflipped.c */
1	nigel	77	/*************************************************
2			* Perl-Compatible Regular Expressions *
3			*************************************************/
4
5			/* PCRE is a library of functions to support regular expressions whose syntax
6			and semantics are as close as possible to those of the Perl 5 language.
7
8			Written by Philip Hazel
9	ph10	455	Copyright (c) 1997-2009 University of Cambridge
10	nigel	77
11			-----------------------------------------------------------------------------
12			Redistribution and use in source and binary forms, with or without
13			modification, are permitted provided that the following conditions are met:
14
15			* Redistributions of source code must retain the above copyright notice,
16			this list of conditions and the following disclaimer.
17
18			* Redistributions in binary form must reproduce the above copyright
19			notice, this list of conditions and the following disclaimer in the
20			documentation and/or other materials provided with the distribution.
21
22			* Neither the name of the University of Cambridge nor the names of its
23			contributors may be used to endorse or promote products derived from
24			this software without specific prior written permission.
25
26			THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
27			AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28			IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29			ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
30			LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31			CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32			SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33			INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34			CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35			ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36			POSSIBILITY OF SUCH DAMAGE.
37			-----------------------------------------------------------------------------
38			*/
39
40
41			/* This module contains an internal function that tests a compiled pattern to
42			see if it was compiled with the opposite endianness. If so, it uses an
43			auxiliary local function to flip the appropriate bytes. */
44
45
46	ph10	200	#ifdef HAVE_CONFIG_H
47	ph10	236	#include "config.h"
48	ph10	200	#endif
49	ph10	199
50	nigel	77	#include "pcre_internal.h"
51
52
53			/*************************************************
54			* Flip bytes in an integer *
55			*************************************************/
56
57			/* This function is called when the magic number in a regex doesn't match, in
58			order to flip its bytes to see if we are dealing with a pattern that was
59			compiled on a host of different endianness. If so, this function is used to
60			flip other byte values.
61
62			Arguments:
63			value the number to flip
64			n the number of bytes to flip (assumed to be 2 or 4)
65
66			Returns: the flipped value
67			*/
68
69	nigel	91	static unsigned long int
70			byteflip(unsigned long int value, int n)
71	nigel	77	{
72			if (n == 2) return ((value & 0x00ff) << 8) \| ((value & 0xff00) >> 8);
73			return ((value & 0x000000ff) << 24) \|
74			((value & 0x0000ff00) << 8) \|
75			((value & 0x00ff0000) >> 8) \|
76			((value & 0xff000000) >> 24);
77			}
78
79
80
81			/*************************************************
82			* Test for a byte-flipped compiled regex *
83			*************************************************/
84
85			/* This function is called from pcre_exec(), pcre_dfa_exec(), and also from
86			pcre_fullinfo(). Its job is to test whether the regex is byte-flipped - that
87			is, it was compiled on a system of opposite endianness. The function is called
88			only when the native MAGIC_NUMBER test fails. If the regex is indeed flipped,
89			we flip all the relevant values into a different data block, and return it.
90
91			Arguments:
92			re points to the regex
93			study points to study data, or NULL
94			internal_re points to a new regex block
95			internal_study points to a new study block
96
97			Returns: the new block if is is indeed a byte-flipped regex
98			NULL if it is not
99			*/
100
101	nigel	87	real_pcre *
102	zherczeg	764	PRIV(try_flipped)(const real_pcre re, real_pcre internal_re,
103	nigel	77	const pcre_study_data study, pcre_study_data internal_study)
104			{
105			if (byteflip(re->magic_number, sizeof(re->magic_number)) != MAGIC_NUMBER)
106			return NULL;
107
108			internal_re = re; /* To copy other fields */
109			internal_re->size = byteflip(re->size, sizeof(re->size));
110			internal_re->options = byteflip(re->options, sizeof(re->options));
111	ph10	230	internal_re->flags = (pcre_uint16)byteflip(re->flags, sizeof(re->flags));
112	nigel	77	internal_re->top_bracket =
113			(pcre_uint16)byteflip(re->top_bracket, sizeof(re->top_bracket));
114			internal_re->top_backref =
115			(pcre_uint16)byteflip(re->top_backref, sizeof(re->top_backref));
116	zherczeg	774	internal_re->first_char =
117			(pcre_uint16)byteflip(re->first_char, sizeof(re->first_char));
118			internal_re->req_char =
119			(pcre_uint16)byteflip(re->req_char, sizeof(re->req_char));
120	nigel	77	internal_re->name_table_offset =
121			(pcre_uint16)byteflip(re->name_table_offset, sizeof(re->name_table_offset));
122			internal_re->name_entry_size =
123			(pcre_uint16)byteflip(re->name_entry_size, sizeof(re->name_entry_size));
124			internal_re->name_count =
125			(pcre_uint16)byteflip(re->name_count, sizeof(re->name_count));
126
127			if (study != NULL)
128			{
129			internal_study = study; /* To copy other fields */
130			internal_study->size = byteflip(study->size, sizeof(study->size));
131	ph10	455	internal_study->flags = byteflip(study->flags, sizeof(study->flags));
132	ph10	461	internal_study->minlength = byteflip(study->minlength,
133	ph10	455	sizeof(study->minlength));
134	nigel	77	}
135
136			return internal_re;
137			}
138
139			/* End of pcre_tryflipped.c */
Name	Value
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svn:keywords	"Author Date Id Revision Url"