[libcamera-devel] [PATCH v6 1/5] libcamera: utils: Add strlcpy

[Laurent Pinchart]

Hi Paul,

Thank you for the patch.

On Fri, Jan 03, 2020 at 07:14:09PM -0500, Paul Elder wrote:
> strlcpy is available in libbsd, bionic, musl, and ulibc, but not in glibc.
> Instead of checking for strlcpy availability and modifying dependencies,
> implement it in utils, as a wrapper around strncpy.
> 
> Signed-off-by: Paul Elder <paul.elder at ideasonboard.com>
> 
> ---
> New in v6
> ---
>  src/libcamera/include/utils.h |  3 +++
>  src/libcamera/utils.cpp       | 19 +++++++++++++++++++
>  2 files changed, 22 insertions(+)
> 
> diff --git a/src/libcamera/include/utils.h b/src/libcamera/include/utils.h
> index a80f7d09..badc7753 100644
> --- a/src/libcamera/include/utils.h
> +++ b/src/libcamera/include/utils.h
> @@ -12,6 +12,7 @@
>  #include <memory>
>  #include <ostream>
>  #include <string>
> +#include <string.h>
>  #include <sys/time.h>
>  
>  #define ARRAY_SIZE(a)	(sizeof(a) / sizeof(a[0]))
> @@ -112,6 +113,8 @@ inline _hex hex<uint64_t>(uint64_t value, unsigned int width)
>  }
>  #endif
>  
> +size_t strlcpy(char *dst, const char *src, size_t size);
> +
>  } /* namespace utils */
>  
>  } /* namespace libcamera */
> diff --git a/src/libcamera/utils.cpp b/src/libcamera/utils.cpp
> index d632f6e6..2d6e082e 100644
> --- a/src/libcamera/utils.cpp
> +++ b/src/libcamera/utils.cpp
> @@ -182,6 +182,25 @@ operator<<(std::basic_ostream<char, std::char_traits<char>> &stream, const _hex
>   * otherwise. The \a os stream configuration is not modified.
>   */
>  
> +/**
> + * \brief Copy a string with a size limit
> + * \param[in] dst The destination string
> + * \param[in] src The source string
> + * \param[in] size The size of the destination string
> + *
> + * strlcpy is available in libbsd, bionic, musl, and ulibc, but not in glibc.
> + * Instead of checking for strlcpy availability and modifying dependencies,
> + * it is implemented here as a wrapper around strncpy.

Shouldn't you instead document what the function does ?

 * This function copy the null-terminated string \a src to \a dst with a limit
 * of \a size - 1 characters, and null-terminates the result if \a size is
 * larger than 0. If \a src is larger than \a size - 1, \a dst is truncated.

> + *
> + * \return The size of \a src
> + */
> +size_t strlcpy(char *dst, const char *src, size_t size)
> +{

	if (size) {

> +	strncpy(dst, src, size);
> +	dst[size - 1] = '\0';

	}

just to be safe ?

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

> +	return strlen(src);
> +}
> +
>  } /* namespace utils */
>  
>  } /* namespace libcamera */

-- 
Regards,

Laurent Pinchart