lib: move strspn()

Allow the function to be individually linkable, discardable, and
overridable. In fact the function is unused at present, and hence will
now get omitted from the final binaries.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>

xen/common/string.c

@@ -8,33 +8,6 @@
 #include <xen/string.h>
 #include <xen/ctype.h>
 
-#ifndef __HAVE_ARCH_STRSPN
-/**
- * strspn - Calculate the length of the initial substring of @s which only
- * 	contain letters in @accept
- * @s: The string to be searched
- * @accept: The string to search for
- */
-size_t strspn(const char *s, const char *accept)
-{
-	const char *p;
-	const char *a;
-	size_t count = 0;
-
-	for (p = s; *p != '\0'; ++p) {
-		for (a = accept; *a != '\0'; ++a) {
-			if (*p == *a)
-				break;
-		}
-		if (*a == '\0')
-			return count;
-		++count;
-	}
-
-	return count;
-}
-#endif
-
 #ifndef __HAVE_ARCH_STRPBRK
 /**
  * strpbrk - Find the first occurrence of a set of characters

xen/lib/Makefile

@@ -24,6 +24,7 @@ lib-y += strncasecmp.o
 lib-y += strncmp.o
 lib-y += strnlen.o
 lib-y += strrchr.o
+lib-y += strspn.o
 lib-y += strstr.o
 lib-$(CONFIG_X86) += xxhash32.o
 lib-$(CONFIG_X86) += xxhash64.o

xen/lib/strspn.c

@@ -0,0 +1,40 @@
+/*
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+#include <xen/string.h>
+
+/**
+ * strspn - Calculate the length of the initial substring of @s which only
+ * 	contain letters in @accept
+ * @s: The string to be searched
+ * @accept: The string to search for
+ */
+size_t strspn(const char *s, const char *accept)
+{
+	const char *p;
+	const char *a;
+	size_t count = 0;
+
+	for (p = s; *p != '\0'; ++p) {
+		for (a = accept; *a != '\0'; ++a) {
+			if (*p == *a)
+				break;
+		}
+		if (*a == '\0')
+			return count;
+		++count;
+	}
+
+	return count;
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 8
+ * tab-width: 8
+ * indent-tabs-mode: t
+ * End:
+ */