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      1 /*************************************************
      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      Original API code Copyright (c) 1997-2012 University of Cambridge
     10          New API code Copyright (c) 2016 University of Cambridge
     11 
     12 -----------------------------------------------------------------------------
     13 Redistribution and use in source and binary forms, with or without
     14 modification, are permitted provided that the following conditions are met:
     15 
     16     * Redistributions of source code must retain the above copyright notice,
     17       this list of conditions and the following disclaimer.
     18 
     19     * Redistributions in binary form must reproduce the above copyright
     20       notice, this list of conditions and the following disclaimer in the
     21       documentation and/or other materials provided with the distribution.
     22 
     23     * Neither the name of the University of Cambridge nor the names of its
     24       contributors may be used to endorse or promote products derived from
     25       this software without specific prior written permission.
     26 
     27 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
     28 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     29 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     30 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
     31 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     32 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     33 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     34 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     35 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     36 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     37 POSSIBILITY OF SUCH DAMAGE.
     38 -----------------------------------------------------------------------------
     39 */
     40 
     41 
     42 #ifdef HAVE_CONFIG_H
     43 #include "config.h"
     44 #endif
     45 
     46 #include "pcre2_internal.h"
     47 
     48 #define STRING(a)  # a
     49 #define XSTRING(s) STRING(s)
     50 
     51 /* The texts of compile-time error messages. Compile-time error numbers start
     52 at COMPILE_ERROR_BASE (100).
     53 
     54 This used to be a table of strings, but in order to reduce the number of
     55 relocations needed when a shared library is loaded dynamically, it is now one
     56 long string. We cannot use a table of offsets, because the lengths of inserts
     57 such as XSTRING(MAX_NAME_SIZE) are not known. Instead,
     58 pcre2_get_error_message() counts through to the one it wants - this isn't a
     59 performance issue because these strings are used only when there is an error.
     60 
     61 Each substring ends with \0 to insert a null character. This includes the final
     62 substring, so that the whole string ends with \0\0, which can be detected when
     63 counting through. */
     64 
     65 static const unsigned char compile_error_texts[] =
     66   "no error\0"
     67   "\\ at end of pattern\0"
     68   "\\c at end of pattern\0"
     69   "unrecognized character follows \\\0"
     70   "numbers out of order in {} quantifier\0"
     71   /* 5 */
     72   "number too big in {} quantifier\0"
     73   "missing terminating ] for character class\0"
     74   "invalid escape sequence in character class\0"
     75   "range out of order in character class\0"
     76   "quantifier does not follow a repeatable item\0"
     77   /* 10 */
     78   "internal error: unexpected repeat\0"
     79   "unrecognized character after (? or (?-\0"
     80   "POSIX named classes are supported only within a class\0"
     81   "POSIX collating elements are not supported\0"
     82   "missing closing parenthesis\0"
     83   /* 15 */
     84   "reference to non-existent subpattern\0"
     85   "pattern passed as NULL\0"
     86   "unrecognised compile-time option bit(s)\0"
     87   "missing ) after (?# comment\0"
     88   "parentheses are too deeply nested\0"
     89   /* 20 */
     90   "regular expression is too large\0"
     91   "failed to allocate heap memory\0"
     92   "unmatched closing parenthesis\0"
     93   "internal error: code overflow\0"
     94   "letter or underscore expected after (?< or (?'\0"
     95   /* 25 */
     96   "lookbehind assertion is not fixed length\0"
     97   "malformed number or name after (?(\0"
     98   "conditional group contains more than two branches\0"
     99   "assertion expected after (?( or (?(?C)\0"
    100   "(?R or (?[+-]digits must be followed by )\0"
    101   /* 30 */
    102   "unknown POSIX class name\0"
    103   "internal error in pcre2_study(): should not occur\0"
    104   "this version of PCRE2 does not have Unicode support\0"
    105   "parentheses are too deeply nested (stack check)\0"
    106   "character code point value in \\x{} or \\o{} is too large\0"
    107   /* 35 */
    108   "invalid condition (?(0)\0"
    109   "\\C is not allowed in a lookbehind assertion in UTF-" XSTRING(PCRE2_CODE_UNIT_WIDTH) " mode\0"
    110   "PCRE does not support \\L, \\l, \\N{name}, \\U, or \\u\0"
    111   "number after (?C is greater than 255\0"
    112   "closing parenthesis for (?C expected\0"
    113   /* 40 */
    114   "invalid escape sequence in (*VERB) name\0"
    115   "unrecognized character after (?P\0"
    116   "syntax error in subpattern name (missing terminator)\0"
    117   "two named subpatterns have the same name (PCRE2_DUPNAMES not set)\0"
    118   "group name must start with a non-digit\0"
    119   /* 45 */
    120   "this version of PCRE2 does not have support for \\P, \\p, or \\X\0"
    121   "malformed \\P or \\p sequence\0"
    122   "unknown property name after \\P or \\p\0"
    123   "subpattern name is too long (maximum " XSTRING(MAX_NAME_SIZE) " characters)\0"
    124   "too many named subpatterns (maximum " XSTRING(MAX_NAME_COUNT) ")\0"
    125   /* 50 */
    126   "invalid range in character class\0"
    127   "octal value is greater than \\377 in 8-bit non-UTF-8 mode\0"
    128   "internal error: overran compiling workspace\0"
    129   "internal error: previously-checked referenced subpattern not found\0"
    130   "DEFINE group contains more than one branch\0"
    131   /* 55 */
    132   "missing opening brace after \\o\0"
    133   "internal error: unknown newline setting\0"
    134   "\\g is not followed by a braced, angle-bracketed, or quoted name/number or by a plain number\0"
    135   "a numbered reference must not be zero\0"
    136   "an argument is not allowed for (*ACCEPT), (*FAIL), or (*COMMIT)\0"
    137   /* 60 */
    138   "(*VERB) not recognized or malformed\0"
    139   "number is too big\0"
    140   "subpattern name expected\0"
    141   "digit expected after (?+\0"
    142   "non-octal character in \\o{} (closing brace missing?)\0"
    143   /* 65 */
    144   "different names for subpatterns of the same number are not allowed\0"
    145   "(*MARK) must have an argument\0"
    146   "non-hex character in \\x{} (closing brace missing?)\0"
    147 #ifndef EBCDIC
    148   "\\c must be followed by a printable ASCII character\0"
    149 #else
    150   "\\c must be followed by a letter or one of [\\]^_?\0"
    151 #endif
    152   "\\k is not followed by a braced, angle-bracketed, or quoted name\0"
    153   /* 70 */
    154   "internal error: unknown opcode in find_fixedlength()\0"
    155   "\\N is not supported in a class\0"
    156   "SPARE ERROR\0"
    157   "disallowed Unicode code point (>= 0xd800 && <= 0xdfff)\0"
    158   "using UTF is disabled by the application\0"
    159   /* 75 */
    160   "using UCP is disabled by the application\0"
    161   "name is too long in (*MARK), (*PRUNE), (*SKIP), or (*THEN)\0"
    162   "character code point value in \\u.... sequence is too large\0"
    163   "digits missing in \\x{} or \\o{}\0"
    164   "syntax error in (?(VERSION condition\0"
    165   /* 80 */
    166   "internal error: unknown opcode in auto_possessify()\0"
    167   "missing terminating delimiter for callout with string argument\0"
    168   "unrecognized string delimiter follows (?C\0"
    169   "using \\C is disabled by the application\0"
    170   "(?| and/or (?J: or (?x: parentheses are too deeply nested\0"
    171   /* 85 */
    172   "using \\C is disabled in this PCRE2 library\0"
    173   "regular expression is too complicated\0"
    174   "lookbehind assertion is too long\0"
    175   "pattern string is longer than the limit set by the application\0"
    176   ;
    177 
    178 /* Match-time and UTF error texts are in the same format. */
    179 
    180 static const unsigned char match_error_texts[] =
    181   "no error\0"
    182   "no match\0"
    183   "partial match\0"
    184   "UTF-8 error: 1 byte missing at end\0"
    185   "UTF-8 error: 2 bytes missing at end\0"
    186   /* 5 */
    187   "UTF-8 error: 3 bytes missing at end\0"
    188   "UTF-8 error: 4 bytes missing at end\0"
    189   "UTF-8 error: 5 bytes missing at end\0"
    190   "UTF-8 error: byte 2 top bits not 0x80\0"
    191   "UTF-8 error: byte 3 top bits not 0x80\0"
    192   /* 10 */
    193   "UTF-8 error: byte 4 top bits not 0x80\0"
    194   "UTF-8 error: byte 5 top bits not 0x80\0"
    195   "UTF-8 error: byte 6 top bits not 0x80\0"
    196   "UTF-8 error: 5-byte character is not allowed (RFC 3629)\0"
    197   "UTF-8 error: 6-byte character is not allowed (RFC 3629)\0"
    198   /* 15 */
    199   "UTF-8 error: code points greater than 0x10ffff are not defined\0"
    200   "UTF-8 error: code points 0xd800-0xdfff are not defined\0"
    201   "UTF-8 error: overlong 2-byte sequence\0"
    202   "UTF-8 error: overlong 3-byte sequence\0"
    203   "UTF-8 error: overlong 4-byte sequence\0"
    204   /* 20 */
    205   "UTF-8 error: overlong 5-byte sequence\0"
    206   "UTF-8 error: overlong 6-byte sequence\0"
    207   "UTF-8 error: isolated byte with 0x80 bit set\0"
    208   "UTF-8 error: illegal byte (0xfe or 0xff)\0"
    209   "UTF-16 error: missing low surrogate at end\0"
    210   /* 25 */
    211   "UTF-16 error: invalid low surrogate\0"
    212   "UTF-16 error: isolated low surrogate\0"
    213   "UTF-32 error: code points 0xd800-0xdfff are not defined\0"
    214   "UTF-32 error: code points greater than 0x10ffff are not defined\0"
    215   "bad data value\0"
    216   /* 30 */
    217   "patterns do not all use the same character tables\0"
    218   "magic number missing\0"
    219   "pattern compiled in wrong mode: 8/16/32-bit error\0"
    220   "bad offset value\0"
    221   "bad option value\0"
    222   /* 35 */
    223   "invalid replacement string\0"
    224   "bad offset into UTF string\0"
    225   "callout error code\0"              /* Never returned by PCRE2 itself */
    226   "invalid data in workspace for DFA restart\0"
    227   "too much recursion for DFA matching\0"
    228   /* 40 */
    229   "backreference condition or recursion test is not supported for DFA matching\0"
    230   "function is not supported for DFA matching\0"
    231   "pattern contains an item that is not supported for DFA matching\0"
    232   "workspace size exceeded in DFA matching\0"
    233   "internal error - pattern overwritten?\0"
    234   /* 45 */
    235   "bad JIT option\0"
    236   "JIT stack limit reached\0"
    237   "match limit exceeded\0"
    238   "no more memory\0"
    239   "unknown substring\0"
    240   /* 50 */
    241   "non-unique substring name\0"
    242   "NULL argument passed\0"
    243   "nested recursion at the same subject position\0"
    244   "recursion limit exceeded\0"
    245   "requested value is not available\0"
    246   /* 55 */
    247   "requested value is not set\0"
    248   "offset limit set without PCRE2_USE_OFFSET_LIMIT\0"
    249   "bad escape sequence in replacement string\0"
    250   "expected closing curly bracket in replacement string\0"
    251   "bad substitution in replacement string\0"
    252   /* 60 */
    253   "match with end before start is not supported\0"
    254   "too many replacements (more than INT_MAX)\0"
    255   "bad serialized data\0"
    256   ;
    257 
    258 
    259 /*************************************************
    260 *            Return error message                *
    261 *************************************************/
    262 
    263 /* This function copies an error message into a buffer whose units are of an
    264 appropriate width. Error numbers are positive for compile-time errors, and
    265 negative for match-time errors (except for UTF errors), but the numbers are all
    266 distinct.
    267 
    268 Arguments:
    269   enumber       error number
    270   buffer        where to put the message (zero terminated)
    271   size          size of the buffer
    272 
    273 Returns:        length of message if all is well
    274                 negative on error
    275 */
    276 
    277 PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
    278 pcre2_get_error_message(int enumber, PCRE2_UCHAR *buffer, size_t size)
    279 {
    280 const unsigned char *message;
    281 size_t i;
    282 int n;
    283 
    284 if (size == 0) return PCRE2_ERROR_NOMEMORY;
    285 
    286 if (enumber >= COMPILE_ERROR_BASE)  /* Compile error */
    287   {
    288   message = compile_error_texts;
    289   n = enumber - COMPILE_ERROR_BASE;
    290   }
    291 else if (enumber < 0)               /* Match or UTF error */
    292   {
    293   message = match_error_texts;
    294   n = -enumber;
    295   }
    296 else                                /* Invalid error number */
    297   {
    298   message = (unsigned char *)"\0";  /* Empty message list */
    299   n = 1;
    300   }
    301 
    302 for (; n > 0; n--)
    303   {
    304   while (*message++ != CHAR_NULL) {};
    305   if (*message == CHAR_NULL) return PCRE2_ERROR_BADDATA;
    306   }
    307 
    308 for (i = 0; *message != 0; i++)
    309   {
    310   if (i >= size - 1)
    311     {
    312     buffer[i] = 0;     /* Terminate partial message */
    313     return PCRE2_ERROR_NOMEMORY;
    314     }
    315   buffer[i] = *message++;
    316   }
    317 
    318 buffer[i] = 0;
    319 return (int)i;
    320 }
    321 
    322 /* End of pcre2_error.c */
    323