Replacement of internal RegEx with PCRE2

The pattern and replacement matching behaviour has been changed purely
due to the nature of switching to a standards-compliant library.

One mistake in the previous behaviour was that named groups didn't have
a number. This has been corrected.

As names are actually just an alias of numbered groups,
RegExMatch::get_name_dict() is now get_names() and is a dict
referring to the group number it represents.

Duplicate names are enabled and the with the first matching instance
used.

Due the lack of a suitable equivalent in PCRE2, RegExMatch::expand() was
removed.

1 files changed, 325 insertions, 0 deletions

diff --git a/thirdparty/pcre2/src/pcre2_error.c b/thirdparty/pcre2/src/pcre2_error.c
new file mode 100644
index 0000000000..437bdfd202
--- /dev/null
+++ b/thirdparty/pcre2/src/pcre2_error.c
@@ -0,0 +1,325 @@
+/*************************************************
+*      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
+     Original API code Copyright (c) 1997-2012 University of Cambridge
+         New API code Copyright (c) 2016 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.
+-----------------------------------------------------------------------------
+*/
+
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "pcre2_internal.h"
+
+#define STRING(a)  # a
+#define XSTRING(s) STRING(s)
+
+/* The texts of compile-time error messages. Compile-time error numbers start
+at COMPILE_ERROR_BASE (100).
+
+This used to be a table of strings, but in order to reduce the number of
+relocations needed when a shared library is loaded dynamically, it is now one
+long string. We cannot use a table of offsets, because the lengths of inserts
+such as XSTRING(MAX_NAME_SIZE) are not known. Instead,
+pcre2_get_error_message() counts through to the one it wants - this isn't a
+performance issue because these strings are used only when there is an error.
+
+Each substring ends with \0 to insert a null character. This includes the final
+substring, so that the whole string ends with \0\0, which can be detected when
+counting through. */
+
+static const unsigned char compile_error_texts[] =
+  "no error\0"
+  "\\ at end of pattern\0"
+  "\\c at end of pattern\0"
+  "unrecognized character follows \\\0"
+  "numbers out of order in {} quantifier\0"
+  /* 5 */
+  "number too big in {} quantifier\0"
+  "missing terminating ] for character class\0"
+  "invalid escape sequence in character class\0"
+  "range out of order in character class\0"
+  "quantifier does not follow a repeatable item\0"
+  /* 10 */
+  "internal error: unexpected repeat\0"
+  "unrecognized character after (? or (?-\0"
+  "POSIX named classes are supported only within a class\0"
+  "POSIX collating elements are not supported\0"
+  "missing closing parenthesis\0"
+  /* 15 */
+  "reference to non-existent subpattern\0"
+  "pattern passed as NULL\0"
+  "unrecognised compile-time option bit(s)\0"
+  "missing ) after (?# comment\0"
+  "parentheses are too deeply nested\0"
+  /* 20 */
+  "regular expression is too large\0"
+  "failed to allocate heap memory\0"
+  "unmatched closing parenthesis\0"
+  "internal error: code overflow\0"
+  "missing closing parenthesis for condition\0"
+  /* 25 */
+  "lookbehind assertion is not fixed length\0"
+  "a relative value of zero is not allowed\0"
+  "conditional group contains more than two branches\0"
+  "assertion expected after (?( or (?(?C)\0"
+  "digit expected after (?+ or (?-\0"
+  /* 30 */
+  "unknown POSIX class name\0"
+  "internal error in pcre2_study(): should not occur\0"
+  "this version of PCRE2 does not have Unicode support\0"
+  "parentheses are too deeply nested (stack check)\0"
+  "character code point value in \\x{} or \\o{} is too large\0"
+  /* 35 */
+  "lookbehind is too complicated\0"
+  "\\C is not allowed in a lookbehind assertion in UTF-" XSTRING(PCRE2_CODE_UNIT_WIDTH) " mode\0"
+  "PCRE does not support \\L, \\l, \\N{name}, \\U, or \\u\0"
+  "number after (?C is greater than 255\0"
+  "closing parenthesis for (?C expected\0"
+  /* 40 */
+  "invalid escape sequence in (*VERB) name\0"
+  "unrecognized character after (?P\0"
+  "syntax error in subpattern name (missing terminator)\0"
+  "two named subpatterns have the same name (PCRE2_DUPNAMES not set)\0"
+  "group name must start with a non-digit\0"
+  /* 45 */
+  "this version of PCRE2 does not have support for \\P, \\p, or \\X\0"
+  "malformed \\P or \\p sequence\0"
+  "unknown property name after \\P or \\p\0"
+  "subpattern name is too long (maximum " XSTRING(MAX_NAME_SIZE) " characters)\0"
+  "too many named subpatterns (maximum " XSTRING(MAX_NAME_COUNT) ")\0"
+  /* 50 */
+  "invalid range in character class\0"
+  "octal value is greater than \\377 in 8-bit non-UTF-8 mode\0"
+  "internal error: overran compiling workspace\0"
+  "internal error: previously-checked referenced subpattern not found\0"
+  "DEFINE group contains more than one branch\0"
+  /* 55 */
+  "missing opening brace after \\o\0"
+  "internal error: unknown newline setting\0"
+  "\\g is not followed by a braced, angle-bracketed, or quoted name/number or by a plain number\0"
+  "(?R (recursive pattern call) must be followed by a closing parenthesis\0"
+  "an argument is not allowed for (*ACCEPT), (*FAIL), or (*COMMIT)\0"
+  /* 60 */
+  "(*VERB) not recognized or malformed\0"
+  "group number is too big\0"
+  "subpattern name expected\0"
+  "internal error: parsed pattern overflow\0"
+  "non-octal character in \\o{} (closing brace missing?)\0"
+  /* 65 */
+  "different names for subpatterns of the same number are not allowed\0"
+  "(*MARK) must have an argument\0"
+  "non-hex character in \\x{} (closing brace missing?)\0"
+#ifndef EBCDIC
+  "\\c must be followed by a printable ASCII character\0"
+#else
+  "\\c must be followed by a letter or one of [\\]^_?\0"
+#endif
+  "\\k is not followed by a braced, angle-bracketed, or quoted name\0"
+  /* 70 */
+  "internal error: unknown meta code in check_lookbehinds()\0"
+  "\\N is not supported in a class\0"
+  "callout string is too long\0"
+  "disallowed Unicode code point (>= 0xd800 && <= 0xdfff)\0"
+  "using UTF is disabled by the application\0"
+  /* 75 */
+  "using UCP is disabled by the application\0"
+  "name is too long in (*MARK), (*PRUNE), (*SKIP), or (*THEN)\0"
+  "character code point value in \\u.... sequence is too large\0"
+  "digits missing in \\x{} or \\o{}\0"
+  "syntax error or number too big in (?(VERSION condition\0"
+  /* 80 */
+  "internal error: unknown opcode in auto_possessify()\0"
+  "missing terminating delimiter for callout with string argument\0"
+  "unrecognized string delimiter follows (?C\0"
+  "using \\C is disabled by the application\0"
+  "(?| and/or (?J: or (?x: parentheses are too deeply nested\0"
+  /* 85 */
+  "using \\C is disabled in this PCRE2 library\0"
+  "regular expression is too complicated\0"
+  "lookbehind assertion is too long\0"
+  "pattern string is longer than the limit set by the application\0"
+  "internal error: unknown code in parsed pattern\0"
+  /* 90 */
+  "internal error: bad code value in parsed_skip()\0"
+  ;
+
+/* Match-time and UTF error texts are in the same format. */
+
+static const unsigned char match_error_texts[] =
+  "no error\0"
+  "no match\0"
+  "partial match\0"
+  "UTF-8 error: 1 byte missing at end\0"
+  "UTF-8 error: 2 bytes missing at end\0"
+  /* 5 */
+  "UTF-8 error: 3 bytes missing at end\0"
+  "UTF-8 error: 4 bytes missing at end\0"
+  "UTF-8 error: 5 bytes missing at end\0"
+  "UTF-8 error: byte 2 top bits not 0x80\0"
+  "UTF-8 error: byte 3 top bits not 0x80\0"
+  /* 10 */
+  "UTF-8 error: byte 4 top bits not 0x80\0"
+  "UTF-8 error: byte 5 top bits not 0x80\0"
+  "UTF-8 error: byte 6 top bits not 0x80\0"
+  "UTF-8 error: 5-byte character is not allowed (RFC 3629)\0"
+  "UTF-8 error: 6-byte character is not allowed (RFC 3629)\0"
+  /* 15 */
+  "UTF-8 error: code points greater than 0x10ffff are not defined\0"
+  "UTF-8 error: code points 0xd800-0xdfff are not defined\0"
+  "UTF-8 error: overlong 2-byte sequence\0"
+  "UTF-8 error: overlong 3-byte sequence\0"
+  "UTF-8 error: overlong 4-byte sequence\0"
+  /* 20 */
+  "UTF-8 error: overlong 5-byte sequence\0"
+  "UTF-8 error: overlong 6-byte sequence\0"
+  "UTF-8 error: isolated byte with 0x80 bit set\0"
+  "UTF-8 error: illegal byte (0xfe or 0xff)\0"
+  "UTF-16 error: missing low surrogate at end\0"
+  /* 25 */
+  "UTF-16 error: invalid low surrogate\0"
+  "UTF-16 error: isolated low surrogate\0"
+  "UTF-32 error: code points 0xd800-0xdfff are not defined\0"
+  "UTF-32 error: code points greater than 0x10ffff are not defined\0"
+  "bad data value\0"
+  /* 30 */
+  "patterns do not all use the same character tables\0"
+  "magic number missing\0"
+  "pattern compiled in wrong mode: 8/16/32-bit error\0"
+  "bad offset value\0"
+  "bad option value\0"
+  /* 35 */
+  "invalid replacement string\0"
+  "bad offset into UTF string\0"
+  "callout error code\0"              /* Never returned by PCRE2 itself */
+  "invalid data in workspace for DFA restart\0"
+  "too much recursion for DFA matching\0"
+  /* 40 */
+  "backreference condition or recursion test is not supported for DFA matching\0"
+  "function is not supported for DFA matching\0"
+  "pattern contains an item that is not supported for DFA matching\0"
+  "workspace size exceeded in DFA matching\0"
+  "internal error - pattern overwritten?\0"
+  /* 45 */
+  "bad JIT option\0"
+  "JIT stack limit reached\0"
+  "match limit exceeded\0"
+  "no more memory\0"
+  "unknown substring\0"
+  /* 50 */
+  "non-unique substring name\0"
+  "NULL argument passed\0"
+  "nested recursion at the same subject position\0"
+  "recursion limit exceeded\0"
+  "requested value is not available\0"
+  /* 55 */
+  "requested value is not set\0"
+  "offset limit set without PCRE2_USE_OFFSET_LIMIT\0"
+  "bad escape sequence in replacement string\0"
+  "expected closing curly bracket in replacement string\0"
+  "bad substitution in replacement string\0"
+  /* 60 */
+  "match with end before start is not supported\0"
+  "too many replacements (more than INT_MAX)\0"
+  "bad serialized data\0"
+  ;
+
+
+/*************************************************
+*            Return error message                *
+*************************************************/
+
+/* This function copies an error message into a buffer whose units are of an
+appropriate width. Error numbers are positive for compile-time errors, and
+negative for match-time errors (except for UTF errors), but the numbers are all
+distinct.
+
+Arguments:
+  enumber       error number
+  buffer        where to put the message (zero terminated)
+  size          size of the buffer
+
+Returns:        length of message if all is well
+                negative on error
+*/
+
+PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
+pcre2_get_error_message(int enumber, PCRE2_UCHAR *buffer, PCRE2_SIZE size)
+{
+const unsigned char *message;
+PCRE2_SIZE i;
+int n;
+
+if (size == 0) return PCRE2_ERROR_NOMEMORY;
+
+if (enumber >= COMPILE_ERROR_BASE)  /* Compile error */
+  {
+  message = compile_error_texts;
+  n = enumber - COMPILE_ERROR_BASE;
+  }
+else if (enumber < 0)               /* Match or UTF error */
+  {
+  message = match_error_texts;
+  n = -enumber;
+  }
+else                                /* Invalid error number */
+  {
+  message = (unsigned char *)"\0";  /* Empty message list */
+  n = 1;
+  }
+
+for (; n > 0; n--)
+  {
+  while (*message++ != CHAR_NULL) {};
+  if (*message == CHAR_NULL) return PCRE2_ERROR_BADDATA;
+  }
+
+for (i = 0; *message != 0; i++)
+  {
+  if (i >= size - 1)
+    {
+    buffer[i] = 0;     /* Terminate partial message */
+    return PCRE2_ERROR_NOMEMORY;
+    }
+  buffer[i] = *message++;
+  }
+
+buffer[i] = 0;
+return (int)i;
+}
+
+/* End of pcre2_error.c */