Add a function to get an unicode codepoint from a utf-8 string. This can be used to convert strings to other representations. Also rewrite the l_utf8_validdate to use the new function. --- ell/string.c | 86 +++++++++++++++++++++++++++++++++++++++--------------------- ell/string.h | 2 ++ 2 files changed, 58 insertions(+), 30 deletions(-) diff --git a/ell/string.c b/ell/string.c index 6c443d0..0ae099c 100644 --- a/ell/string.c +++ b/ell/string.c @@ -345,6 +345,58 @@ static inline bool __attribute__ ((always_inline)) } /** + * l_utf8_get_codepoint + * @str: a pointer to codepoint data + * @len: maximum bytes to read + * @cp: destination for codepoint + * + * Returns: number of bytes read, or -1 for invalid coddepoint + **/ +LIB_EXPORT int l_utf8_get_codepoint(const char *str, size_t len, wchar_t *cp) +{ + static const int mins[3] = { 1 << 7, 1 << 11, 1 << 16 }; + unsigned int expect_bytes; + wchar_t val; + size_t i; + + if (str[0] > 0) { + *cp = str[0]; + return 1; + } + + expect_bytes = __builtin_clz(~(str[0] << 24)); + + if (expect_bytes < 2 || expect_bytes > 4) + goto error; + + if (expect_bytes > len) + goto error; + + val = str[0] & (0xff >> (expect_bytes + 1)); + + for (i = 1; i < expect_bytes; i++) { + if ((str[i] & 0xc0) == 0) + goto error; + + val <<= 6; + val |= str[i] & 0x3f; + } + + if (val < mins[expect_bytes - 2]) + goto error; + + if (valid_unicode(val) == false) + goto error; + + *cp = val; + return expect_bytes; + +error: + *cp = 0; + return -1; +} + +/** * l_utf8_validate: * @str: a pointer to character data * @len: max bytes to validate @@ -359,43 +411,17 @@ static inline bool __attribute__ ((always_inline)) **/ LIB_EXPORT bool l_utf8_validate(const char *str, size_t len, const char **end) { - static const int mins[3] = { 1 << 7, 1 << 11, 1 << 16 }; size_t pos = 0; - unsigned int expect_bytes; + int ret; wchar_t val; - size_t i; while (pos < len && str[pos]) { - if (str[pos] > 0) { - pos += 1; - continue; - } - - expect_bytes = __builtin_clz(~(str[pos] << 24)); - - if (expect_bytes < 2 || expect_bytes > 4) - goto error; - - if (pos + expect_bytes > len) - goto error; - - val = str[pos] & (0xff >> (expect_bytes + 1)); - - for (i = pos + 1; i < pos + expect_bytes; i++) { - if ((str[i] & 0xc0) == 0) - goto error; - - val <<= 6; - val |= str[i] & 0x3f; - } - - if (val < mins[expect_bytes - 2]) - goto error; + ret = l_utf8_get_codepoint(str + pos, len - pos, &val); - if (valid_unicode(val) == false) + if (ret < 0) goto error; - pos += expect_bytes; + pos += ret; } error: diff --git a/ell/string.h b/ell/string.h index 6549a05..09e6f2d 100644 --- a/ell/string.h +++ b/ell/string.h @@ -25,6 +25,7 @@ #include <stdbool.h> #include <stdarg.h> +#include <wchar.h> #ifdef __cplusplus extern "C" { @@ -117,6 +118,7 @@ struct l_string *l_string_truncate(struct l_string *string, size_t new_size); unsigned int l_string_length(struct l_string *string); bool l_utf8_validate(const char *src, size_t len, const char **end); +int l_utf8_get_codepoint(const char *str, size_t len, wchar_t *cp); size_t l_utf8_strlen(const char *src); #ifdef __cplusplus -- 2.10.2