Commit upstream pcre-8.39.tar.bz2

1 files changed, 301 insertions, 0 deletions

diff --git a/pcre_valid_utf8.c b/pcre_valid_utf8.c
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+++ b/pcre_valid_utf8.c
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+/*************************************************
+*      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) 1997-2013 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 for validating UTF-8 character
+strings. */
+
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "pcre_internal.h"
+
+
+/*************************************************
+*         Validate a UTF-8 string                *
+*************************************************/
+
+/* This function is called (optionally) at the start of compile or match, to
+check that a supposed UTF-8 string is actually valid. The early check means
+that subsequent code can assume it is dealing with a valid string. The check
+can be turned off for maximum performance, but the consequences of supplying an
+invalid string are then undefined.
+
+Originally, this function checked according to RFC 2279, allowing for values in
+the range 0 to 0x7fffffff, up to 6 bytes long, but ensuring that they were in
+the canonical format. Once somebody had pointed out RFC 3629 to me (it
+obsoletes 2279), additional restrictions were applied. The values are now
+limited to be between 0 and 0x0010ffff, no more than 4 bytes long, and the
+subrange 0xd000 to 0xdfff is excluded. However, the format of 5-byte and 6-byte
+characters is still checked.
+
+From release 8.13 more information about the details of the error are passed
+back in the returned value:
+
+PCRE_UTF8_ERR0   No error
+PCRE_UTF8_ERR1   Missing 1 byte at the end of the string
+PCRE_UTF8_ERR2   Missing 2 bytes at the end of the string
+PCRE_UTF8_ERR3   Missing 3 bytes at the end of the string
+PCRE_UTF8_ERR4   Missing 4 bytes at the end of the string
+PCRE_UTF8_ERR5   Missing 5 bytes at the end of the string
+PCRE_UTF8_ERR6   2nd-byte's two top bits are not 0x80
+PCRE_UTF8_ERR7   3rd-byte's two top bits are not 0x80
+PCRE_UTF8_ERR8   4th-byte's two top bits are not 0x80
+PCRE_UTF8_ERR9   5th-byte's two top bits are not 0x80
+PCRE_UTF8_ERR10  6th-byte's two top bits are not 0x80
+PCRE_UTF8_ERR11  5-byte character is not permitted by RFC 3629
+PCRE_UTF8_ERR12  6-byte character is not permitted by RFC 3629
+PCRE_UTF8_ERR13  4-byte character with value > 0x10ffff is not permitted
+PCRE_UTF8_ERR14  3-byte character with value 0xd000-0xdfff is not permitted
+PCRE_UTF8_ERR15  Overlong 2-byte sequence
+PCRE_UTF8_ERR16  Overlong 3-byte sequence
+PCRE_UTF8_ERR17  Overlong 4-byte sequence
+PCRE_UTF8_ERR18  Overlong 5-byte sequence (won't ever occur)
+PCRE_UTF8_ERR19  Overlong 6-byte sequence (won't ever occur)
+PCRE_UTF8_ERR20  Isolated 0x80 byte (not within UTF-8 character)
+PCRE_UTF8_ERR21  Byte with the illegal value 0xfe or 0xff
+PCRE_UTF8_ERR22  Unused (was non-character)
+
+Arguments:
+  string       points to the string
+  length       length of string, or -1 if the string is zero-terminated
+  errp         pointer to an error position offset variable
+
+Returns:       = 0    if the string is a valid UTF-8 string
+               > 0    otherwise, setting the offset of the bad character
+*/
+
+int
+PRIV(valid_utf)(PCRE_PUCHAR string, int length, int *erroroffset)
+{
+#ifdef SUPPORT_UTF
+register PCRE_PUCHAR p;
+
+if (length < 0)
+  {
+  for (p = string; *p != 0; p++);
+  length = (int)(p - string);
+  }
+
+for (p = string; length-- > 0; p++)
+  {
+  register pcre_uchar ab, c, d;
+
+  c = *p;
+  if (c < 128) continue;                /* ASCII character */
+
+  if (c < 0xc0)                         /* Isolated 10xx xxxx byte */
+    {
+    *erroroffset = (int)(p - string);
+    return PCRE_UTF8_ERR20;
+    }
+
+  if (c >= 0xfe)                        /* Invalid 0xfe or 0xff bytes */
+    {
+    *erroroffset = (int)(p - string);
+    return PCRE_UTF8_ERR21;
+    }
+
+  ab = PRIV(utf8_table4)[c & 0x3f];     /* Number of additional bytes */
+  if (length < ab)
+    {
+    *erroroffset = (int)(p - string);          /* Missing bytes */
+    return ab - length;                 /* Codes ERR1 to ERR5 */
+    }
+  length -= ab;                         /* Length remaining */
+
+  /* Check top bits in the second byte */
+
+  if (((d = *(++p)) & 0xc0) != 0x80)
+    {
+    *erroroffset = (int)(p - string) - 1;
+    return PCRE_UTF8_ERR6;
+    }
+
+  /* For each length, check that the remaining bytes start with the 0x80 bit
+  set and not the 0x40 bit. Then check for an overlong sequence, and for the
+  excluded range 0xd800 to 0xdfff. */
+
+  switch (ab)
+    {
+    /* 2-byte character. No further bytes to check for 0x80. Check first byte
+    for for xx00 000x (overlong sequence). */
+
+    case 1: if ((c & 0x3e) == 0)
+      {
+      *erroroffset = (int)(p - string) - 1;
+      return PCRE_UTF8_ERR15;
+      }
+    break;
+
+    /* 3-byte character. Check third byte for 0x80. Then check first 2 bytes
+      for 1110 0000, xx0x xxxx (overlong sequence) or
+          1110 1101, 1010 xxxx (0xd800 - 0xdfff) */
+
+    case 2:
+    if ((*(++p) & 0xc0) != 0x80)     /* Third byte */
+      {
+      *erroroffset = (int)(p - string) - 2;
+      return PCRE_UTF8_ERR7;
+      }
+    if (c == 0xe0 && (d & 0x20) == 0)
+      {
+      *erroroffset = (int)(p - string) - 2;
+      return PCRE_UTF8_ERR16;
+      }
+    if (c == 0xed && d >= 0xa0)
+      {
+      *erroroffset = (int)(p - string) - 2;
+      return PCRE_UTF8_ERR14;
+      }
+    break;
+
+    /* 4-byte character. Check 3rd and 4th bytes for 0x80. Then check first 2
+       bytes for for 1111 0000, xx00 xxxx (overlong sequence), then check for a
+       character greater than 0x0010ffff (f4 8f bf bf) */
+
+    case 3:
+    if ((*(++p) & 0xc0) != 0x80)     /* Third byte */
+      {
+      *erroroffset = (int)(p - string) - 2;
+      return PCRE_UTF8_ERR7;
+      }
+    if ((*(++p) & 0xc0) != 0x80)     /* Fourth byte */
+      {
+      *erroroffset = (int)(p - string) - 3;
+      return PCRE_UTF8_ERR8;
+      }
+    if (c == 0xf0 && (d & 0x30) == 0)
+      {
+      *erroroffset = (int)(p - string) - 3;
+      return PCRE_UTF8_ERR17;
+      }
+    if (c > 0xf4 || (c == 0xf4 && d > 0x8f))
+      {
+      *erroroffset = (int)(p - string) - 3;
+      return PCRE_UTF8_ERR13;
+      }
+    break;
+
+    /* 5-byte and 6-byte characters are not allowed by RFC 3629, and will be
+    rejected by the length test below. However, we do the appropriate tests
+    here so that overlong sequences get diagnosed, and also in case there is
+    ever an option for handling these larger code points. */
+
+    /* 5-byte character. Check 3rd, 4th, and 5th bytes for 0x80. Then check for
+    1111 1000, xx00 0xxx */
+
+    case 4:
+    if ((*(++p) & 0xc0) != 0x80)     /* Third byte */
+      {
+      *erroroffset = (int)(p - string) - 2;
+      return PCRE_UTF8_ERR7;
+      }
+    if ((*(++p) & 0xc0) != 0x80)     /* Fourth byte */
+      {
+      *erroroffset = (int)(p - string) - 3;
+      return PCRE_UTF8_ERR8;
+      }
+    if ((*(++p) & 0xc0) != 0x80)     /* Fifth byte */
+      {
+      *erroroffset = (int)(p - string) - 4;
+      return PCRE_UTF8_ERR9;
+      }
+    if (c == 0xf8 && (d & 0x38) == 0)
+      {
+      *erroroffset = (int)(p - string) - 4;
+      return PCRE_UTF8_ERR18;
+      }
+    break;
+
+    /* 6-byte character. Check 3rd-6th bytes for 0x80. Then check for
+    1111 1100, xx00 00xx. */
+
+    case 5:
+    if ((*(++p) & 0xc0) != 0x80)     /* Third byte */
+      {
+      *erroroffset = (int)(p - string) - 2;
+      return PCRE_UTF8_ERR7;
+      }
+    if ((*(++p) & 0xc0) != 0x80)     /* Fourth byte */
+      {
+      *erroroffset = (int)(p - string) - 3;
+      return PCRE_UTF8_ERR8;
+      }
+    if ((*(++p) & 0xc0) != 0x80)     /* Fifth byte */
+      {
+      *erroroffset = (int)(p - string) - 4;
+      return PCRE_UTF8_ERR9;
+      }
+    if ((*(++p) & 0xc0) != 0x80)     /* Sixth byte */
+      {
+      *erroroffset = (int)(p - string) - 5;
+      return PCRE_UTF8_ERR10;
+      }
+    if (c == 0xfc && (d & 0x3c) == 0)
+      {
+      *erroroffset = (int)(p - string) - 5;
+      return PCRE_UTF8_ERR19;
+      }
+    break;
+    }
+
+  /* Character is valid under RFC 2279, but 4-byte and 5-byte characters are
+  excluded by RFC 3629. The pointer p is currently at the last byte of the
+  character. */
+
+  if (ab > 3)
+    {
+    *erroroffset = (int)(p - string) - ab;
+    return (ab == 4)? PCRE_UTF8_ERR11 : PCRE_UTF8_ERR12;
+    }
+  }
+
+#else  /* Not SUPPORT_UTF */
+(void)(string);  /* Keep picky compilers happy */
+(void)(length);
+(void)(erroroffset);
+#endif
+
+return PCRE_UTF8_ERR0;   /* This indicates success */
+}
+
+/* End of pcre_valid_utf8.c */