On Sat, 16 Apr 2022 at 16:32, Heinrich Schuchardt xypron.glpk@gmx.de wrote:
On 3/24/22 14:54, Masahisa Kojima wrote:
Provide u16 string version of strlcat().
Signed-off-by: Masahisa Kojima masahisa.kojima@linaro.org Reviewed-by: Simon Glass sjg@chromium.org
Changes in v4:
- add blank line above the return statement
Changes in v2:
implement u16_strlcat(with the destination buffer size in argument) instead of u16_strcat
include/charset.h | 15 +++++++++++++++ lib/charset.c | 21 +++++++++++++++++++++ 2 files changed, 36 insertions(+)
diff --git a/include/charset.h b/include/charset.h index b93d023092..dc5fc275ec 100644 --- a/include/charset.h +++ b/include/charset.h @@ -259,6 +259,21 @@ u16 *u16_strcpy(u16 *dest, const u16 *src); */ u16 *u16_strdup(const void *src);
+/**
- u16_strlcat() - Append a length-limited, %NUL-terminated string to another
- Append the src string to the dest string, overwriting the terminating
- null word at the end of dest, and then adds a terminating null word.
- It will append at most size - u16_strlen(dst) - 1 bytes, NUL-terminating the result.
Why "- 1"?
It is my mistake, it should be 2.
If size is even, we append up to size - u16_strlen(dst) - 2 bytes. The two extra bytes used for 0x0000. If size is odd, we append up to size - u16_strlen(dst) - 3 bytes leaving one byte of the buffer unused.
Thanks, It clearly explains the behavior.
- @dest: destination buffer (null terminated)
- @src: source buffer (null terminated)
- @size: destination buffer size in bytes
s/$/ including the trailing 0x0000/
OK, I will update "(null terminated)" to the suggested one.
- Return: total size of the created string in bytes.
If return value >= size, truncation occurred.- */
+size_t u16_strlcat(u16 *dest, const u16 *src, size_t size);
- /**
- utf16_to_utf8() - Convert an utf16 string to utf8
diff --git a/lib/charset.c b/lib/charset.c index f44c58d9d8..47997eca7d 100644 --- a/lib/charset.c +++ b/lib/charset.c @@ -428,6 +428,27 @@ u16 *u16_strdup(const void *src) return new; }
+size_t u16_strlcat(u16 *dest, const u16 *src, size_t size) +{
If you start the function with
size >>= 1;or
size /= sizeof(u16);this might simplify the code.
In u16_strlcat(), there are two size definitions, u16 string size and buffer size. I will rename some of the variables to clearly identify the meaning.
size_t dstrlen = u16_strnlen(dest, size >> 1);size_t dlen = dstrlen * sizeof(u16);size_t len = u16_strlen(src) * sizeof(u16);size_t ret = dlen + len;This misses the trailing 0x0000.
Strlcat() is not the C standard function, but the linux implementation of strlcat() does not include trailing 0x00[1], also the same for openbsd. [1] https://github.com/torvalds/linux/blob/master/lib/string.c#L319.
The current U-Boot strlcat() contains trailing 0x00, I think it needs to be updated.
Thanks, Masahisa Kojima
Best regards
Heinrich
if (dlen >= size)return ret;dest += dstrlen;size -= dlen;if (len >= size)len = size - sizeof(u16);memcpy(dest, src, len);dest[len >> 1] = u'\0';return ret;+}
- /* Convert UTF-16 to UTF-8. */ uint8_t *utf16_to_utf8(uint8_t *dest, const uint16_t *src, size_t size) {