From b5586a6c4294b46eb23d1fc527ff63dcd27e23ac Mon Sep 17 00:00:00 2001 From: Ran Benita Date: Fri, 2 Dec 2016 22:15:19 +0200 Subject: [PATCH] keysym: fix locale dependence in xkb_keysym_from_name() We currently use strcasecmp, which is locale-dependent. In particular, one well-known surprise even if restricted just ASCII input is found in the tr_TR (Turkish) locale, see e.g. https://msdn.microsoft.com/en-us/library/ms973919.aspx#stringsinnet20_topic5 We have known to avoid locale-dependent functions before, but in this case, we forgot. Fix it by implementing our own simple ASCII-only strcasecmp/strncasecmp. Might have been possible to use strcasecmp_l() with the C locale, but went the easy route. Side advantage is that even this non-optimized version is faster than the optimized libc one (__strcasecmp_l_sse42) since it doesn't need to do the locale stuff. xkb_keysym_from_name(), which uses strcasecmp heavily, becomes faster, and so for example Compose file parsing, which uses xkb_keysym_from_name() heavily, becomes ~20% faster. Resolves https://github.com/xkbcommon/libxkbcommon/issues/42 Signed-off-by: Ran Benita --- configure.ac | 6 ------ src/keysym.c | 8 ++++---- src/utils.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++ src/utils.h | 14 +++++++++++--- test/keysym.c | 22 +++++++++++++++++++++ 5 files changed, 90 insertions(+), 13 deletions(-) diff --git a/configure.ac b/configure.ac index fdab4ab..3484c8c 100644 --- a/configure.ac +++ b/configure.ac @@ -68,12 +68,6 @@ AS_IF([test ! -f "src/xkbcomp/parser.c" -a "x$YACC_INST" = x], [ ]) # Checks for library functions. -AC_CHECK_FUNCS([strcasecmp strncasecmp]) -AS_IF([test "x$ac_cv_func_strcasecmp" = xno -o \ - "x$ac_cv_func_strncasecmp" = xno], [ - AC_MSG_ERROR([C library does not support strcasecmp/strncasecmp]) -]) - AC_CHECK_FUNCS([eaccess euidaccess mmap]) AC_CHECK_FUNCS([secure_getenv __secure_getenv]) diff --git a/src/keysym.c b/src/keysym.c index db0e973..9e7b4fb 100644 --- a/src/keysym.c +++ b/src/keysym.c @@ -76,7 +76,7 @@ compare_by_name(const void *a, const void *b) { const char *key = a; const struct name_keysym *entry = b; - return strcasecmp(key, get_name(entry)); + return istrcmp(key, get_name(entry)); } XKB_EXPORT int @@ -109,7 +109,7 @@ xkb_keysym_get_name(xkb_keysym_t ks, char *buffer, size_t size) /* * Find the correct keysym if one case-insensitive match is given. * - * The name_to_keysym table is sorted by strcasecmp(). So bsearch() may return + * The name_to_keysym table is sorted by istrcmp(). So bsearch() may return * _any_ of all possible case-insensitive duplicates. This function searches the * returned entry @entry, all previous and all next entries that match by * case-insensitive comparison and returns the exact match to @name. If @icase @@ -138,7 +138,7 @@ find_sym(const struct name_keysym *entry, const char *name, bool icase) for (iter = entry - 1; iter >= name_to_keysym; --iter) { if (!icase && strcmp(get_name(iter), name) == 0) return iter; - if (strcasecmp(get_name(iter), get_name(entry)) != 0) + if (istrcmp(get_name(iter), get_name(entry)) != 0) break; if (icase && xkb_keysym_is_lower(iter->keysym)) return iter; @@ -148,7 +148,7 @@ find_sym(const struct name_keysym *entry, const char *name, bool icase) for (iter = entry + 1; iter < last; ++iter) { if (!icase && strcmp(get_name(iter), name) == 0) return iter; - if (strcasecmp(get_name(iter), get_name(entry)) != 0) + if (istrcmp(get_name(iter), get_name(entry)) != 0) break; if (icase && xkb_keysym_is_lower(iter->keysym)) return iter; diff --git a/src/utils.c b/src/utils.c index d725bbd..a71b570 100644 --- a/src/utils.c +++ b/src/utils.c @@ -108,3 +108,56 @@ unmap_file(char *str, size_t size) } #endif + +// ASCII lower-case map. +static const unsigned char lower_map[] = { + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, + 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, + 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, + 59, 60, 61, 62, 63, 64, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, + 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, + 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, + 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, + 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, + 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, + 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, + 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, + 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, + 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, + 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, + 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, + 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255 +}; + +// ASCII tolower (to avoid locale issues). +char +to_lower(char c) +{ + return (char) lower_map[(unsigned char) c]; +} + +// ASCII strcasecmp (to avoid locale issues). +int +istrcmp(const char *a, const char *b) +{ + for (size_t i = 0; ; i++) { + if (to_lower(a[i]) != to_lower(b[i])) + return (int) to_lower(a[i]) - (int) to_lower(b[i]); + if (!a[i]) + break; + } + return 0; +} + +// ASCII strncasecmp (to avoid locale issues). +int +istrncmp(const char *a, const char *b, size_t n) +{ + for (size_t i = 0; i < n; i++) { + if (to_lower(a[i]) != to_lower(b[i])) + return (int) to_lower(a[i]) - (int) to_lower(b[i]); + if (!a[i]) + break; + } + return 0; +} diff --git a/src/utils.h b/src/utils.h index d63d23a..cb98e8e 100644 --- a/src/utils.h +++ b/src/utils.h @@ -29,7 +29,6 @@ #include #include #include -#include #include "darray.h" @@ -44,6 +43,15 @@ switch (0) { case 0: case (expr): ; } \ } while (0) +char +to_lower(char c); + +int +istrcmp(const char *a, const char *b); + +int +istrncmp(const char *a, const char *b, size_t n); + static inline bool streq(const char *s1, const char *s2) { @@ -61,13 +69,13 @@ streq_not_null(const char *s1, const char *s2) static inline bool istreq(const char *s1, const char *s2) { - return strcasecmp(s1, s2) == 0; + return istrcmp(s1, s2) == 0; } static inline bool istreq_prefix(const char *s1, const char *s2) { - return strncasecmp(s1, s2, strlen(s1)) == 0; + return istrncmp(s1, s2, strlen(s1)) == 0; } static inline char * diff --git a/test/keysym.c b/test/keysym.c index 439622c..4414523 100644 --- a/test/keysym.c +++ b/test/keysym.c @@ -20,6 +20,7 @@ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * DEALINGS IN THE SOFTWARE. */ +#include #include "test.h" #include "keysym.h" /* For unexported is_lower/upper/keypad() */ @@ -81,6 +82,25 @@ test_utf8(xkb_keysym_t keysym, const char *expected) return streq(s, expected); } +static void +test_github_issue_42(void) +{ + // Verify we are not dependent on locale, Turkish-i problem in particular. + if (setlocale(LC_CTYPE, "tr_TR.UTF-8") == NULL) { + // The locale is not available, probably; skip. + return; + } + + assert(test_string("i", XKB_KEY_i)); + assert(test_string("I", XKB_KEY_I)); + assert(test_casestring("i", XKB_KEY_i)); + assert(test_casestring("I", XKB_KEY_i)); + assert(xkb_keysym_to_upper(XKB_KEY_i) == XKB_KEY_I); + assert(xkb_keysym_to_lower(XKB_KEY_I) == XKB_KEY_i); + + setlocale(LC_CTYPE, "C"); +} + int main(void) { @@ -196,5 +216,7 @@ main(void) assert(xkb_keysym_to_upper(XKB_KEY_eacute) == XKB_KEY_Eacute); assert(xkb_keysym_to_lower(XKB_KEY_Eacute) == XKB_KEY_eacute); + test_github_issue_42(); + return 0; }