xnu-201.tar.gz

[apple/xnu.git] / iokit / Kernel / IOStringFuncs.c

diff --git a/iokit/Kernel/IOStringFuncs.c b/iokit/Kernel/IOStringFuncs.c
index 8fe5ddec5b808bc02e650913750340f7b30cc443..0e20f8c505fca6906d30ae4a8376d0748e5dd612 100644 (file)
--- a/iokit/Kernel/IOStringFuncs.c
+++ b/iokit/Kernel/IOStringFuncs.c
@@ -70,6 +70,7 @@
 #include <stdlib.h>
 #include <limits.h>
 */
+#include <sys/types.h>
 #include <stddef.h>
 #include <machine/limits.h>
 
@@ -257,6 +258,172 @@ strtoul(nptr, endptr, base)
        return (acc);
 }
 
+/*
+ * Convert a string to a quad integer.
+ *
+ * Ignores `locale' stuff.  Assumes that the upper and lower case
+ * alphabets and digits are each contiguous.
+ */
+quad_t
+strtoq(nptr, endptr, base)
+       const char *nptr;
+       char **endptr;
+       register int base;
+{
+       register const char *s;
+       register u_quad_t acc;
+       register int c;
+       register u_quad_t qbase, cutoff;
+       register int neg, any, cutlim;
+
+       /*
+        * Skip white space and pick up leading +/- sign if any.
+        * If base is 0, allow 0x for hex and 0 for octal, else
+        * assume decimal; if base is already 16, allow 0x.
+        */
+       s = nptr;
+       do {
+               c = *s++;
+       } while (isspace(c));
+       if (c == '-') {
+               neg = 1;
+               c = *s++;
+       } else {
+               neg = 0;
+               if (c == '+')
+                       c = *s++;
+       }
+       if ((base == 0 || base == 16) &&
+           c == '0' && (*s == 'x' || *s == 'X')) {
+               c = s[1];
+               s += 2;
+               base = 16;
+       }
+       if (base == 0)
+               base = c == '0' ? 8 : 10;
+
+       /*
+        * Compute the cutoff value between legal numbers and illegal
+        * numbers.  That is the largest legal value, divided by the
+        * base.  An input number that is greater than this value, if
+        * followed by a legal input character, is too big.  One that
+        * is equal to this value may be valid or not; the limit
+        * between valid and invalid numbers is then based on the last
+        * digit.  For instance, if the range for quads is
+        * [-9223372036854775808..9223372036854775807] and the input base
+        * is 10, cutoff will be set to 922337203685477580 and cutlim to
+        * either 7 (neg==0) or 8 (neg==1), meaning that if we have
+        * accumulated a value > 922337203685477580, or equal but the
+        * next digit is > 7 (or 8), the number is too big, and we will
+        * return a range error.
+        *
+        * Set any if any `digits' consumed; make it negative to indicate
+        * overflow.
+        */
+       qbase = (unsigned)base;
+       cutoff = neg ? -(u_quad_t)QUAD_MIN : QUAD_MAX;
+       cutlim = cutoff % qbase;
+       cutoff /= qbase;
+       for (acc = 0, any = 0;; c = *s++) {
+               if (isdigit(c))
+                       c -= '0';
+               else if (isalpha(c))
+                       c -= isupper(c) ? 'A' - 10 : 'a' - 10;
+               else
+                       break;
+               if (c >= base)
+                       break;
+               if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim)
+                       any = -1;
+               else {
+                       any = 1;
+                       acc *= qbase;
+                       acc += c;
+               }
+       }
+       if (any < 0) {
+               acc = neg ? QUAD_MIN : QUAD_MAX;
+//             errno = ERANGE;
+       } else if (neg)
+               acc = -acc;
+       if (endptr != 0)
+               *endptr = (char *)(any ? s - 1 : nptr);
+       return (acc);
+}
+
+
+/*
+ * Convert a string to an unsigned quad integer.
+ *
+ * Ignores `locale' stuff.  Assumes that the upper and lower case
+ * alphabets and digits are each contiguous.
+ */
+u_quad_t
+strtouq(nptr, endptr, base)
+       const char *nptr;
+       char **endptr;
+       register int base;
+{
+       register const char *s = nptr;
+       register u_quad_t acc;
+       register int c;
+       register u_quad_t qbase, cutoff;
+       register int neg, any, cutlim;
+
+       /*
+        * See strtoq for comments as to the logic used.
+        */
+       s = nptr;
+       do {
+               c = *s++;
+       } while (isspace(c));
+       if (c == '-') {
+               neg = 1;
+               c = *s++;
+       } else { 
+               neg = 0;
+               if (c == '+')
+                       c = *s++;
+       }
+       if ((base == 0 || base == 16) &&
+           c == '0' && (*s == 'x' || *s == 'X')) {
+               c = s[1];
+               s += 2;
+               base = 16;
+       }
+       if (base == 0)
+               base = c == '0' ? 8 : 10;
+       qbase = (unsigned)base;
+       cutoff = (u_quad_t)UQUAD_MAX / qbase;
+       cutlim = (u_quad_t)UQUAD_MAX % qbase;
+       for (acc = 0, any = 0;; c = *s++) {
+               if (isdigit(c))
+                       c -= '0';
+               else if (isalpha(c))
+                       c -= isupper(c) ? 'A' - 10 : 'a' - 10;
+               else
+                       break;
+               if (c >= base)
+                       break;
+               if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim)
+                       any = -1;
+               else {
+                       any = 1;
+                       acc *= qbase;
+                       acc += c;
+               }
+       }
+       if (any < 0) {
+               acc = UQUAD_MAX;
+//             errno = ERANGE;
+       } else if (neg)
+               acc = -acc;
+       if (endptr != 0)
+               *endptr = (char *)(any ? s - 1 : nptr);
+       return (acc);
+}
+
+
 /*
  *
  */