| xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame] | 1 | /* Compare strings while treating digits characters numerically. |
| 2 | Copyright (C) 1997-2016 Free Software Foundation, Inc. |
| 3 | This file is part of the GNU C Library. |
| 4 | Contributed by Jean-François Bignolles <bignolle@ecoledoc.ibp.fr>, 1997. |
| 5 | |
| 6 | The GNU C Library is free software; you can redistribute it and/or |
| 7 | modify it under the terms of the GNU Lesser General Public |
| 8 | License as published by the Free Software Foundation; either |
| 9 | version 2.1 of the License, or (at your option) any later version. |
| 10 | |
| 11 | The GNU C Library is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | Lesser General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU Lesser General Public |
| 17 | License along with the GNU C Library; if not, see |
| 18 | <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include <stdint.h> |
| 21 | #include <string.h> |
| 22 | #include <ctype.h> |
| 23 | |
| 24 | /* states: S_N: normal, S_I: comparing integral part, S_F: comparing |
| 25 | fractionnal parts, S_Z: idem but with leading Zeroes only */ |
| 26 | #define S_N 0x0 |
| 27 | #define S_I 0x3 |
| 28 | #define S_F 0x6 |
| 29 | #define S_Z 0x9 |
| 30 | |
| 31 | /* result_type: CMP: return diff; LEN: compare using len_diff/diff */ |
| 32 | #define CMP 2 |
| 33 | #define LEN 3 |
| 34 | |
| 35 | |
| 36 | /* Compare S1 and S2 as strings holding indices/version numbers, |
| 37 | returning less than, equal to or greater than zero if S1 is less than, |
| 38 | equal to or greater than S2 (for more info, see the texinfo doc). |
| 39 | */ |
| 40 | |
| 41 | int |
| 42 | __strverscmp (const char *s1, const char *s2) |
| 43 | { |
| 44 | const unsigned char *p1 = (const unsigned char *) s1; |
| 45 | const unsigned char *p2 = (const unsigned char *) s2; |
| 46 | |
| 47 | /* Symbol(s) 0 [1-9] others |
| 48 | Transition (10) 0 (01) d (00) x */ |
| 49 | static const uint8_t next_state[] = |
| 50 | { |
| 51 | /* state x d 0 */ |
| 52 | /* S_N */ S_N, S_I, S_Z, |
| 53 | /* S_I */ S_N, S_I, S_I, |
| 54 | /* S_F */ S_N, S_F, S_F, |
| 55 | /* S_Z */ S_N, S_F, S_Z |
| 56 | }; |
| 57 | |
| 58 | static const int8_t result_type[] = |
| 59 | { |
| 60 | /* state x/x x/d x/0 d/x d/d d/0 0/x 0/d 0/0 */ |
| 61 | |
| 62 | /* S_N */ CMP, CMP, CMP, CMP, LEN, CMP, CMP, CMP, CMP, |
| 63 | /* S_I */ CMP, -1, -1, +1, LEN, LEN, +1, LEN, LEN, |
| 64 | /* S_F */ CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, |
| 65 | /* S_Z */ CMP, +1, +1, -1, CMP, CMP, -1, CMP, CMP |
| 66 | }; |
| 67 | |
| 68 | if (p1 == p2) |
| 69 | return 0; |
| 70 | |
| 71 | unsigned char c1 = *p1++; |
| 72 | unsigned char c2 = *p2++; |
| 73 | /* Hint: '0' is a digit too. */ |
| 74 | int state = S_N + ((c1 == '0') + (isdigit (c1) != 0)); |
| 75 | |
| 76 | int diff; |
| 77 | while ((diff = c1 - c2) == 0) |
| 78 | { |
| 79 | if (c1 == '\0') |
| 80 | return diff; |
| 81 | |
| 82 | state = next_state[state]; |
| 83 | c1 = *p1++; |
| 84 | c2 = *p2++; |
| 85 | state += (c1 == '0') + (isdigit (c1) != 0); |
| 86 | } |
| 87 | |
| 88 | state = result_type[state * 3 + (((c2 == '0') + (isdigit (c2) != 0)))]; |
| 89 | |
| 90 | switch (state) |
| 91 | { |
| 92 | case CMP: |
| 93 | return diff; |
| 94 | |
| 95 | case LEN: |
| 96 | while (isdigit (*p1++)) |
| 97 | if (!isdigit (*p2++)) |
| 98 | return 1; |
| 99 | |
| 100 | return isdigit (*p2) ? -1 : diff; |
| 101 | |
| 102 | default: |
| 103 | return state; |
| 104 | } |
| 105 | } |
| 106 | libc_hidden_def (__strverscmp) |
| 107 | weak_alias (__strverscmp, strverscmp) |