Elliott Hughes | 9bc971b | 2018-07-27 13:23:14 -0700 | [diff] [blame] | 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 |
Elliott Hughes | 0c26e19 | 2019-08-07 12:24:46 -0700 | [diff] [blame^] | 10 | New API code Copyright (c) 2016-2019 University of Cambridge |
Elliott Hughes | 9bc971b | 2018-07-27 13:23:14 -0700 | [diff] [blame] | 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 | /* This module contains an internal function that is used to match a Unicode |
| 42 | extended grapheme sequence. It is used by both pcre2_match() and |
| 43 | pcre2_def_match(). However, it is called only when Unicode support is being |
| 44 | compiled. Nevertheless, we provide a dummy function when there is no Unicode |
| 45 | support, because some compilers do not like functionless source files. */ |
| 46 | |
| 47 | |
| 48 | #ifdef HAVE_CONFIG_H |
| 49 | #include "config.h" |
| 50 | #endif |
| 51 | |
| 52 | |
| 53 | #include "pcre2_internal.h" |
| 54 | |
| 55 | |
| 56 | /* Dummy function */ |
| 57 | |
| 58 | #ifndef SUPPORT_UNICODE |
| 59 | PCRE2_SPTR |
| 60 | PRIV(extuni)(uint32_t c, PCRE2_SPTR eptr, PCRE2_SPTR start_subject, |
| 61 | PCRE2_SPTR end_subject, BOOL utf, int *xcount) |
| 62 | { |
| 63 | (void)c; |
| 64 | (void)eptr; |
| 65 | (void)start_subject; |
| 66 | (void)end_subject; |
| 67 | (void)utf; |
| 68 | (void)xcount; |
| 69 | return NULL; |
| 70 | } |
| 71 | #else |
| 72 | |
| 73 | |
| 74 | /************************************************* |
| 75 | * Match an extended grapheme sequence * |
| 76 | *************************************************/ |
| 77 | |
| 78 | /* |
| 79 | Arguments: |
| 80 | c the first character |
| 81 | eptr pointer to next character |
| 82 | start_subject pointer to start of subject |
| 83 | end_subject pointer to end of subject |
| 84 | utf TRUE if in UTF mode |
| 85 | xcount pointer to count of additional characters, |
| 86 | or NULL if count not needed |
| 87 | |
| 88 | Returns: pointer after the end of the sequence |
| 89 | */ |
| 90 | |
| 91 | PCRE2_SPTR |
| 92 | PRIV(extuni)(uint32_t c, PCRE2_SPTR eptr, PCRE2_SPTR start_subject, |
| 93 | PCRE2_SPTR end_subject, BOOL utf, int *xcount) |
| 94 | { |
| 95 | int lgb = UCD_GRAPHBREAK(c); |
| 96 | |
| 97 | while (eptr < end_subject) |
| 98 | { |
| 99 | int rgb; |
| 100 | int len = 1; |
| 101 | if (!utf) c = *eptr; else { GETCHARLEN(c, eptr, len); } |
| 102 | rgb = UCD_GRAPHBREAK(c); |
Elliott Hughes | 0c26e19 | 2019-08-07 12:24:46 -0700 | [diff] [blame^] | 103 | if ((PRIV(ucp_gbtable)[lgb] & (1u << rgb)) == 0) break; |
Elliott Hughes | 9bc971b | 2018-07-27 13:23:14 -0700 | [diff] [blame] | 104 | |
| 105 | /* Not breaking between Regional Indicators is allowed only if there |
| 106 | are an even number of preceding RIs. */ |
| 107 | |
| 108 | if (lgb == ucp_gbRegionalIndicator && rgb == ucp_gbRegionalIndicator) |
| 109 | { |
| 110 | int ricount = 0; |
| 111 | PCRE2_SPTR bptr = eptr - 1; |
| 112 | if (utf) BACKCHAR(bptr); |
| 113 | |
| 114 | /* bptr is pointing to the left-hand character */ |
| 115 | |
| 116 | while (bptr > start_subject) |
| 117 | { |
| 118 | bptr--; |
| 119 | if (utf) |
| 120 | { |
| 121 | BACKCHAR(bptr); |
| 122 | GETCHAR(c, bptr); |
| 123 | } |
| 124 | else |
| 125 | c = *bptr; |
| 126 | if (UCD_GRAPHBREAK(c) != ucp_gbRegionalIndicator) break; |
| 127 | ricount++; |
| 128 | } |
| 129 | if ((ricount & 1) != 0) break; /* Grapheme break required */ |
| 130 | } |
| 131 | |
Elliott Hughes | 653c210 | 2019-01-09 15:41:36 -0800 | [diff] [blame] | 132 | /* If Extend or ZWJ follows Extended_Pictographic, do not update lgb; this |
| 133 | allows any number of them before a following Extended_Pictographic. */ |
Elliott Hughes | 9bc971b | 2018-07-27 13:23:14 -0700 | [diff] [blame] | 134 | |
Elliott Hughes | 653c210 | 2019-01-09 15:41:36 -0800 | [diff] [blame] | 135 | if ((rgb != ucp_gbExtend && rgb != ucp_gbZWJ) || |
| 136 | lgb != ucp_gbExtended_Pictographic) |
Elliott Hughes | 9bc971b | 2018-07-27 13:23:14 -0700 | [diff] [blame] | 137 | lgb = rgb; |
| 138 | |
| 139 | eptr += len; |
| 140 | if (xcount != NULL) *xcount += 1; |
| 141 | } |
| 142 | |
| 143 | return eptr; |
| 144 | } |
| 145 | |
| 146 | #endif /* SUPPORT_UNICODE */ |
| 147 | |
| 148 | /* End of pcre2_extuni.c */ |