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| author | Paul Eggert <eggert@cs.ucla.edu> | 2016-02-21 13:25:24 -0800 |
|---|---|---|
| committer | Paul Eggert <eggert@cs.ucla.edu> | 2016-02-21 13:27:40 -0800 |
| commit | 1f7feecaee0ed3fb79758fe60020aefb30d9ff01 (patch) | |
| tree | b0476096aabea32658be041242caa74e7a5232cd /lib/filevercmp.c | |
| parent | 3e67708d7239cde24b0988d4d1288bc75585cfea (diff) | |
| download | emacs-1f7feecaee0ed3fb79758fe60020aefb30d9ff01.tar.gz emacs-1f7feecaee0ed3fb79758fe60020aefb30d9ff01.tar.bz2 emacs-1f7feecaee0ed3fb79758fe60020aefb30d9ff01.zip | |
Use Gnulib filevercmp for version comparison
* admin/merge-gnulib (GNULIB_MODULES): Add filevercmp.
* doc/lispref/strings.texi (Text Comparison):
* etc/NEWS, src/fns.c:
* test/src/fns-tests.el (fns-tests-string-version-lessp):
Rename newly-introduced function to string-version-lessp, by
analogy with strverscmp.
* lib/filevercmp.c, lib/filevercmp.h: New files, copied from gnulib.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
* src/fns.c: Include <filevercmp.h>.
(gather_number_from_string): Remove.
(Fstring_version_lessp): Reimplement via filevercmp.
Diffstat (limited to 'lib/filevercmp.c')
| -rw-r--r-- | lib/filevercmp.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/lib/filevercmp.c b/lib/filevercmp.c new file mode 100644 index 00000000000..a75c9468e31 --- /dev/null +++ b/lib/filevercmp.c @@ -0,0 +1,181 @@ +/* + Copyright (C) 1995 Ian Jackson <iwj10@cus.cam.ac.uk> + Copyright (C) 2001 Anthony Towns <aj@azure.humbug.org.au> + Copyright (C) 2008-2016 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + +#include <config.h> +#include "filevercmp.h" + +#include <sys/types.h> +#include <stdlib.h> +#include <stdbool.h> +#include <string.h> +#include <c-ctype.h> +#include <limits.h> + +/* Match a file suffix defined by this regular expression: + /(\.[A-Za-z~][A-Za-z0-9~]*)*$/ + Scan the string *STR and return a pointer to the matching suffix, or + NULL if not found. Upon return, *STR points to terminating NUL. */ +static const char * +match_suffix (const char **str) +{ + const char *match = NULL; + bool read_alpha = false; + while (**str) + { + if (read_alpha) + { + read_alpha = false; + if (!c_isalpha (**str) && '~' != **str) + match = NULL; + } + else if ('.' == **str) + { + read_alpha = true; + if (!match) + match = *str; + } + else if (!c_isalnum (**str) && '~' != **str) + match = NULL; + (*str)++; + } + return match; +} + +/* verrevcmp helper function */ +static int +order (unsigned char c) +{ + if (c_isdigit (c)) + return 0; + else if (c_isalpha (c)) + return c; + else if (c == '~') + return -1; + else + return (int) c + UCHAR_MAX + 1; +} + +/* slightly modified verrevcmp function from dpkg + S1, S2 - compared string + S1_LEN, S2_LEN - length of strings to be scanned + + This implements the algorithm for comparison of version strings + specified by Debian and now widely adopted. The detailed + specification can be found in the Debian Policy Manual in the + section on the 'Version' control field. This version of the code + implements that from s5.6.12 of Debian Policy v3.8.0.1 + http://www.debian.org/doc/debian-policy/ch-controlfields.html#s-f-Version */ +static int _GL_ATTRIBUTE_PURE +verrevcmp (const char *s1, size_t s1_len, const char *s2, size_t s2_len) +{ + size_t s1_pos = 0; + size_t s2_pos = 0; + while (s1_pos < s1_len || s2_pos < s2_len) + { + int first_diff = 0; + while ((s1_pos < s1_len && !c_isdigit (s1[s1_pos])) + || (s2_pos < s2_len && !c_isdigit (s2[s2_pos]))) + { + int s1_c = (s1_pos == s1_len) ? 0 : order (s1[s1_pos]); + int s2_c = (s2_pos == s2_len) ? 0 : order (s2[s2_pos]); + if (s1_c != s2_c) + return s1_c - s2_c; + s1_pos++; + s2_pos++; + } + while (s1[s1_pos] == '0') + s1_pos++; + while (s2[s2_pos] == '0') + s2_pos++; + while (c_isdigit (s1[s1_pos]) && c_isdigit (s2[s2_pos])) + { + if (!first_diff) + first_diff = s1[s1_pos] - s2[s2_pos]; + s1_pos++; + s2_pos++; + } + if (c_isdigit (s1[s1_pos])) + return 1; + if (c_isdigit (s2[s2_pos])) + return -1; + if (first_diff) + return first_diff; + } + return 0; +} + +/* Compare version strings S1 and S2. + See filevercmp.h for function description. */ +int +filevercmp (const char *s1, const char *s2) +{ + const char *s1_pos; + const char *s2_pos; + const char *s1_suffix, *s2_suffix; + size_t s1_len, s2_len; + int result; + + /* easy comparison to see if strings are identical */ + int simple_cmp = strcmp (s1, s2); + if (simple_cmp == 0) + return 0; + + /* special handle for "", "." and ".." */ + if (!*s1) + return -1; + if (!*s2) + return 1; + if (0 == strcmp (".", s1)) + return -1; + if (0 == strcmp (".", s2)) + return 1; + if (0 == strcmp ("..", s1)) + return -1; + if (0 == strcmp ("..", s2)) + return 1; + + /* special handle for other hidden files */ + if (*s1 == '.' && *s2 != '.') + return -1; + if (*s1 != '.' && *s2 == '.') + return 1; + if (*s1 == '.' && *s2 == '.') + { + s1++; + s2++; + } + + /* "cut" file suffixes */ + s1_pos = s1; + s2_pos = s2; + s1_suffix = match_suffix (&s1_pos); + s2_suffix = match_suffix (&s2_pos); + s1_len = (s1_suffix ? s1_suffix : s1_pos) - s1; + s2_len = (s2_suffix ? s2_suffix : s2_pos) - s2; + + /* restore file suffixes if strings are identical after "cut" */ + if ((s1_suffix || s2_suffix) && (s1_len == s2_len) + && 0 == strncmp (s1, s2, s1_len)) + { + s1_len = s1_pos - s1; + s2_len = s2_pos - s2; + } + + result = verrevcmp (s1, s1_len, s2, s2_len); + return result == 0 ? simple_cmp : result; +} |