lib: pull base-guessing logic to helper function

The default base is 10 unless there is a leading zero, in which
case the base will be guessed as 8.

The base will only be guesed as 16 when the string starts with '0x'
the third character is a valid hex digit.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 4c6674a..1a9c6b9 100644 (file)
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -32,6 +32,18 @@
 /* Works only for digits and letters, but small and fast */
 #define TOLOWER(x) ((x) | 0x20)
 
+static unsigned int simple_guess_base(const char *cp)
+{
+       if (cp[0] == '0') {
+               if (TOLOWER(cp[1]) == 'x' && isxdigit(cp[2]))
+                       return 16;
+               else
+                       return 8;
+       } else {
+               return 10;
+       }
+}
+
 /**
  * simple_strtoul - convert a string to an unsigned long
  * @cp: The start of the string
@@ -40,32 +52,28 @@
  */
 unsigned long simple_strtoul(const char *cp,char **endp,unsigned int base)
 {
-       unsigned long result = 0,value;
+       unsigned long result = 0;
 
-       if (!base) {
-               base = 10;
-               if (*cp == '0') {
-                       base = 8;
-                       cp++;
-                       if ((TOLOWER(*cp) == 'x') && isxdigit(cp[1])) {
-                               cp++;
-                               base = 16;
-                       }
-               }
-       } else if (base == 16) {
-               if (cp[0] == '0' && TOLOWER(cp[1]) == 'x')
-                       cp += 2;
-       }
-       while (isxdigit(*cp) &&
-              (value = isdigit(*cp) ? *cp-'0' : TOLOWER(*cp)-'a'+10) < base) {
-               result = result*base + value;
+       if (!base)
+               base = simple_guess_base(cp);
+
+       if (base == 16 && cp[0] == '0' && TOLOWER(cp[1]) == 'x')
+               cp += 2;
+
+       while (isxdigit(*cp)) {
+               unsigned int value;
+
+               value = isdigit(*cp) ? *cp - '0' : TOLOWER(*cp) - 'a' + 10;
+               if (value >= base)
+                       break;
+               result = result * base + value;
                cp++;
        }
+
        if (endp)
                *endp = (char *)cp;
        return result;
 }
-
 EXPORT_SYMBOL(simple_strtoul);
 
 /**
@@ -91,32 +99,28 @@ EXPORT_SYMBOL(simple_strtol);
  */
 unsigned long long simple_strtoull(const char *cp,char **endp,unsigned int base)
 {
-       unsigned long long result = 0,value;
+       unsigned long long result = 0;
 
-       if (!base) {
-               base = 10;
-               if (*cp == '0') {
-                       base = 8;
-                       cp++;
-                       if ((TOLOWER(*cp) == 'x') && isxdigit(cp[1])) {
-                               cp++;
-                               base = 16;
-                       }
-               }
-       } else if (base == 16) {
-               if (cp[0] == '0' && TOLOWER(cp[1]) == 'x')
-                       cp += 2;
-       }
-       while (isxdigit(*cp)
-        && (value = isdigit(*cp) ? *cp-'0' : TOLOWER(*cp)-'a'+10) < base) {
-               result = result*base + value;
+       if (!base)
+               base = simple_guess_base(cp);
+
+       if (base == 16 && cp[0] == '0' && TOLOWER(cp[1]) == 'x')
+               cp += 2;
+
+       while (isxdigit(*cp)) {
+               unsigned int value;
+
+               value = isdigit(*cp) ? *cp - '0' : TOLOWER(*cp) - 'a' + 10;
+               if (value >= base)
+                       break;
+               result = result * base + value;
                cp++;
        }
+
        if (endp)
                *endp = (char *)cp;
        return result;
 }
-
 EXPORT_SYMBOL(simple_strtoull);
 
 /**