1 files changed, 140 insertions, 0 deletions

diff --git a/src/lib/libc/stdlib/strtoimax.c b/src/lib/libc/stdlib/strtoimax.c
new file mode 100644
index 0000000000..2c77f41650
--- /dev/null
+++ b/src/lib/libc/stdlib/strtoimax.c
@@ -0,0 +1,140 @@
+/*      $OpenBSD: strtoimax.c,v 1.1 2006/01/13 17:58:09 millert Exp $   */
+
+/*-
+ * Copyright (c) 1992 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <ctype.h>
+#include <errno.h>
+#include <inttypes.h>
+
+/*
+ * Convert a string to an intmax_t
+ *
+ * Ignores `locale' stuff.  Assumes that the upper and lower case
+ * alphabets and digits are each contiguous.
+ */
+intmax_t
+strtoimax(const char *nptr, char **endptr, int base)
+{
+        const char *s;
+        intmax_t acc, cutoff;
+        int c;
+        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 = (unsigned char) *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 intmax_t 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.
+         */
+        cutoff = neg ? INTMAX_MIN : INTMAX_MAX;
+        cutlim = cutoff % base;
+        cutoff /= base;
+        if (neg) {
+                if (cutlim > 0) {
+                        cutlim -= base;
+                        cutoff += 1;
+                }
+                cutlim = -cutlim;
+        }
+        for (acc = 0, any = 0;; c = (unsigned char) *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)
+                        continue;
+                if (neg) {
+                        if (acc < cutoff || (acc == cutoff && c > cutlim)) {
+                                any = -1;
+                                acc = INTMAX_MIN;
+                                errno = ERANGE;
+                        } else {
+                                any = 1;
+                                acc *= base;
+                                acc -= c;
+                        }
+                } else {
+                        if (acc > cutoff || (acc == cutoff && c > cutlim)) {
+                                any = -1;
+                                acc = INTMAX_MAX;
+                                errno = ERANGE;
+                        } else {
+                                any = 1;
+                                acc *= base;
+                                acc += c;
+                        }
+                }
+        }
+        if (endptr != 0)
+                *endptr = (char *) (any ? s - 1 : nptr);
+        return (acc);
+}