Add strcasecmp() and strncasecmp()

strncasecmp() is present as strnicmp() but disabled. Make it available
and define strcasecmp() also. There is a only a small performance penalty
to having strcasecmp() call strncasecmp(), so do this instead of a
standalone function, to save code space.

Update the prototype in arch-specific headers as needed to avoid warnings.

Signed-off-by: Simon Glass <sjg@chromium.org>

arch/m68k/include/asm/string.h

@@ -16,7 +16,7 @@
 #endif
 
 extern int strcasecmp(const char *, const char *);
-extern int strncasecmp(const char *, const char *, int);
+extern int strncasecmp(const char *, const char *, __kernel_size_t);
 extern char * strcpy(char *,const char *);
 extern char * strncpy(char *,const char *, __kernel_size_t);
 extern __kernel_size_t strlen(const char *);

arch/powerpc/include/asm/string.h

@@ -14,7 +14,7 @@
 #define __HAVE_ARCH_MEMCHR
 
 extern int strcasecmp(const char *, const char *);
-extern int strncasecmp(const char *, const char *, int);
+extern int strncasecmp(const char *, const char *, __kernel_size_t);
 extern char * strcpy(char *,const char *);
 extern char * strncpy(char *,const char *, __kernel_size_t);
 extern __kernel_size_t strlen(const char *);

arch/sparc/include/asm/string.h

@@ -40,7 +40,7 @@
 */
 
 extern int strcasecmp(const char *, const char *);
-extern int strncasecmp(const char *, const char *, int);
+extern int strncasecmp(const char *, const char *, __kernel_size_t);
 extern char *strcpy(char *, const char *);
 extern char *strncpy(char *, const char *, __kernel_size_t);
 extern __kernel_size_t strlen(const char *);

include/linux/string.h

@@ -38,8 +38,11 @@ extern int strcmp(const char *,const char *);
 #ifndef __HAVE_ARCH_STRNCMP
 extern int strncmp(const char *,const char *,__kernel_size_t);
 #endif
-#if 0 /* not used - was: #ifndef __HAVE_ARCH_STRNICMP */
-extern int strnicmp(const char *, const char *, __kernel_size_t);
+#ifndef __HAVE_ARCH_STRCASECMP
+int strcasecmp(const char *s1, const char *s2);
+#endif
+#ifndef __HAVE_ARCH_STRNCASECMP
+extern int strncasecmp(const char *s1, const char *s2, __kernel_size_t len);
 #endif
 #ifndef __HAVE_ARCH_STRCHR
 extern char * strchr(const char *,int);

lib/string.c

@@ -21,14 +21,13 @@
 #include <malloc.h>
 
 
-#if 0 /* not used - was: #ifndef __HAVE_ARCH_STRNICMP */
 /**
- * strnicmp - Case insensitive, length-limited string comparison
+ * strncasecmp - Case insensitive, length-limited string comparison
  * @s1: One string
  * @s2: The other string
  * @len: the maximum number of characters to compare
  */
-int strnicmp(const char *s1, const char *s2, size_t len)
+int strncasecmp(const char *s1, const char *s2, size_t len)
 {
 	/* Yes, Virginia, it had better be unsigned */
 	unsigned char c1, c2;
@@ -52,7 +51,16 @@ int strnicmp(const char *s1, const char *s2, size_t len)
 	}
 	return (int)c1 - (int)c2;
 }
-#endif
+
+/**
+ * strcasecmp - Case insensitive string comparison
+ * @s1: One string
+ * @s2: The other string
+ */
+int strcasecmp(const char *s1, const char *s2)
+{
+	return strncasecmp(s1, s2, -1U);
+}
 
 char * ___strtok;