Re: [Tarantool-patches] [PATCH v4 1/4] util: introduce strlcpy helper

[Serge Petrenko <sergepetrenko@tarantool.org>]

11.12.2020 10:34, Serge Petrenko via Tarantool-patches пишет:
>
> 10.12.2020 19:18, Cyrill Gorcunov пишет:
>> Very convenient to have this string extension.
>> We will use it in crash handling.
>>
>> Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
>> ---
>
> Hi! Thanks for the patch!
>
> LGTM.
>
>> CMakeLists.txt            |  1 +
>>   src/lib/core/util.c       | 14 ++++++++++++++
>>   src/trivia/config.h.cmake |  5 +++++
>>   src/trivia/util.h         | 15 +++++++++++++++
>>   4 files changed, 35 insertions(+)
>>
>> diff --git a/CMakeLists.txt b/CMakeLists.txt
>> index fa6818f8e..aa23113b3 100644
>> --- a/CMakeLists.txt
>> +++ b/CMakeLists.txt
>> @@ -126,6 +126,7 @@ set(CMAKE_REQUIRED_LIBRARIES "")
>>   check_function_exists(clock_gettime HAVE_CLOCK_GETTIME_WITHOUT_RT)
>>     check_symbol_exists(__get_cpuid cpuid.h HAVE_CPUID)
>> +check_symbol_exists(strlcpy string.h HAVE_STRLCPY)
>>     # Checks for libev
>>   include(CheckStructHasMember)
>> diff --git a/src/lib/core/util.c b/src/lib/core/util.c
>> index dfce317f0..7b168a177 100644
>> --- a/src/lib/core/util.c
>> +++ b/src/lib/core/util.c
>> @@ -250,6 +250,20 @@ int2str(long long int val)
>>       return buf;
>>   }
>>   +#ifndef HAVE_STRLCPY
>> +size_t
>> +strlcpy(char *dst, const char *src, size_t size)
>> +{
>> +    size_t src_len = strlen(src);
>> +    if (size) {


One nit: we usually use `if(smth)` for boolean values only.

For integer values please use the explicit variant: `if(size != 0)`


>> +        size_t len = (src_len >= size) ? size - 1 : src_len;
>> +        memcpy(dst, src, len);
>> +        dst[len] = '\0';
>> +    }
>> +    return src_len;
>> +}
>> +#endif
>> +
>>   int
>>   utf8_check_printable(const char *start, size_t length)
>>   {
>> diff --git a/src/trivia/config.h.cmake b/src/trivia/config.h.cmake
>> index 89e0d39c6..21efb978e 100644
>> --- a/src/trivia/config.h.cmake
>> +++ b/src/trivia/config.h.cmake
>> @@ -47,6 +47,11 @@
>>    */
>>   #cmakedefine HAVE_CPUID 1
>>   +/**
>> + * Defined if strlcpy() string extension helper present.
>> + */
>> + #cmakedefine HAVE_STRLCPY 1
>> +
>>   /*
>>    * Defined if gcov instrumentation should be enabled.
>>    */
>> diff --git a/src/trivia/util.h b/src/trivia/util.h
>> index da5a3705e..8dcc48ada 100644
>> --- a/src/trivia/util.h
>> +++ b/src/trivia/util.h
>> @@ -450,6 +450,21 @@ fpconv_strtod(const char *nptr, char **endptr)
>>       return strtod(nptr, endptr);
>>   }
>>   +#ifndef HAVE_STRLCPY
>> +/**
>> + * Copy string. Unlike \a strncpy the result string
>> + * is always null-terminated.
>> + *
>> + * @param dst destination buffer.
>> + * @param src source string.
>> + * @param size destination buffer size.
>> + *
>> + * @return size of \a src string.
>> + */
>> +size_t
>> +strlcpy(char *dst, const char *src, size_t size);
>> +#endif
>> +
>>   /**
>>    * Check that @a str is valid utf-8 sequence and can be printed
>>    * unescaped.
>
-- 
Serge Petrenko