efi_loader: rename utf16_strlen, utf16_strnlen

The function names utf16_strlen() and utf16_strnlen() are misnomers.
The functions do not count utf-16 characters but non-zero words.
So let's rename them to u16_strlen and u16_strnlen().

In utf16_dup() avoid assignment in if clause.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>

include/charset.h

@@ -13,29 +13,29 @@
 #define MAX_UTF8_PER_UTF16 3
 
 /**
- * utf16_strlen() - Get the length of an utf16 string
+ * u16_strlen - count non-zero words
  *
- * Returns the number of 16 bit characters in an utf16 string, not
- * including the terminating NULL character.
+ * This function matches wsclen() if the -fshort-wchar compiler flag is set.
+ * In the EFI context we explicitly need a function handling u16 strings.
  *
- * @in     the string to measure
- * @return the string length
+ * @in:			null terminated u16 string
+ * ReturnValue:		number of non-zero words.
+ *			This is not the number of utf-16 letters!
  */
-size_t utf16_strlen(const uint16_t *in);
+size_t u16_strlen(const u16 *in);
 
 /**
- * utf16_strnlen() - Get the length of a fixed-size utf16 string.
+ * u16_strlen - count non-zero words
  *
- * Returns the number of 16 bit characters in an utf16 string,
- * not including the terminating NULL character, but at most
- * 'count' number of characters.  In doing this, utf16_strnlen()
- * looks at only the first 'count' characters.
+ * This function matches wscnlen_s() if the -fshort-wchar compiler flag is set.
+ * In the EFI context we explicitly need a function handling u16 strings.
  *
- * @in     the string to measure
- * @count  the maximum number of characters to count
- * @return the string length, up to a maximum of 'count'
+ * @in:			null terminated u16 string
+ * @count:		maximum number of words to count
+ * ReturnValue:		number of non-zero words.
+ *			This is not the number of utf-16 letters!
  */
-size_t utf16_strnlen(const uint16_t *in, size_t count);
+size_t u16_strnlen(const u16 *in, size_t count);
 
 /**
  * utf16_strcpy() - UTF16 equivalent of strcpy()

lib/charset.c

@@ -12,14 +12,14 @@
  * utf8/utf16 conversion mostly lifted from grub
  */
 
-size_t utf16_strlen(const uint16_t *in)
+size_t u16_strlen(const u16 *in)
 {
 	size_t i;
 	for (i = 0; in[i]; i++);
 	return i;
 }
 
-size_t utf16_strnlen(const uint16_t *in, size_t count)
+size_t u16_strnlen(const u16 *in, size_t count)
 {
 	size_t i;
 	for (i = 0; count-- && in[i]; i++);
@@ -39,7 +39,11 @@ uint16_t *utf16_strcpy(uint16_t *dest, const uint16_t *src)
 uint16_t *utf16_strdup(const uint16_t *s)
 {
 	uint16_t *new;
-	if (!s || !(new = malloc((utf16_strlen(s) + 1) * 2)))
+
+	if (!s)
+		return NULL;
+	new = malloc((u16_strlen(s) + 1) * 2);
+	if (!new)
 		return NULL;
 	utf16_strcpy(new, s);
 	return new;

lib/efi_loader/efi_bootmgr.c

@@ -60,7 +60,7 @@ static void parse_load_option(struct load_option *lo, void *ptr)
 	ptr += sizeof(u16);
 
 	lo->label = ptr;
-	ptr += (utf16_strlen(lo->label) + 1) * 2;
+	ptr += (u16_strlen(lo->label) + 1) * 2;
 
 	lo->file_path = ptr;
 	ptr += lo->file_path_length;

lib/efi_loader/efi_console.c

@@ -114,7 +114,7 @@ static efi_status_t EFIAPI efi_cout_output_string(
 
 	EFI_ENTRY("%p, %p", this, string);
 
-	unsigned int n16 = utf16_strlen(string);
+	unsigned int n16 = u16_strlen(string);
 	char buf[MAX_UTF8_PER_UTF16 * n16 + 1];
 	u16 *p;
 

lib/efi_loader/efi_file.c

@@ -140,7 +140,7 @@ static struct efi_file_handle *file_open(struct file_system *fs,
 
 	if (file_name) {
 		utf16_to_utf8((u8 *)f0, (u16 *)file_name, 1);
-		flen = utf16_strlen((u16 *)file_name);
+		flen = u16_strlen((u16 *)file_name);
 	}
 
 	/* we could have a parent, but also an absolute path: */

lib/efi_loader/efi_variable.c

@@ -106,7 +106,7 @@ static efi_status_t efi_to_native(char *native, u16 *variable_name,
 {
 	size_t len;
 
-	len = utf16_strlen((u16 *)variable_name);
+	len = u16_strlen((u16 *)variable_name);
 	if (len >= MAX_VAR_NAME)
 		return EFI_DEVICE_ERROR;
 

lib/vsprintf.c

@@ -280,7 +280,7 @@ static char *string16(char *buf, char *end, u16 *s, int field_width,
 		int precision, int flags)
 {
 	u16 *str = s ? s : L"<NULL>";
-	int utf16_len = utf16_strnlen(str, precision);
+	int utf16_len = u16_strnlen(str, precision);
 	u8 utf8[utf16_len * MAX_UTF8_PER_UTF16];
 	int utf8_len, i;