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-rw-r--r--libc/stdlib/strto_l.c192
1 files changed, 192 insertions, 0 deletions
diff --git a/libc/stdlib/strto_l.c b/libc/stdlib/strto_l.c
new file mode 100644
index 000000000..a83cf4095
--- /dev/null
+++ b/libc/stdlib/strto_l.c
@@ -0,0 +1,192 @@
+/*
+ * Copyright (C) 2000 Manuel Novoa III
+ *
+ * Notes:
+ *
+ * The primary objective of this implementation was minimal size.
+ *
+ * Note: Assumes char layout 0-9.*A-Z.*a-z for ordinals values.
+ *
+ * There are a couple of compile-time options below.
+ *
+ */
+
+/*****************************************************************************/
+/* OPTIONS */
+/*****************************************************************************/
+
+/* Set if we want strtod to set errno appropriately. */
+/* NOTE: Implies _STRTO_ENDPTR below */
+#define _STRTO_ERRNO 0
+
+/* Set if we want support for the endptr arg. */
+/* Implied by _STRTO_ERRNO. */
+#define _STRTO_ENDPTR 1
+
+/*****************************************************************************/
+/* Don't change anything that follows. */
+/*****************************************************************************/
+
+#if _STRTO_ERRNO
+#undef _STRTO_ENDPTR
+#define _STRTO_ENDPTR 1
+#endif
+
+/*****************************************************************************/
+
+/* Are there actually any machines where this might fail? */
+#if 'A' > 'a'
+#error ordering assumption violated : 'A' > 'a'
+#endif
+
+#include <stdlib.h>
+#include <limits.h>
+#include <ctype.h>
+
+#if _STRTO_ERRNO
+#include <errno.h>
+#endif
+
+unsigned long _strto_l(const char *str, char **endptr, int base, int uflag);
+
+#if L_strto_l
+
+/*
+ * This is the main work fuction which handles both strtol (uflag = 0) and
+ * strtoul (uflag = 1).
+ */
+
+unsigned long _strto_l(const char *str, char **endptr, int base, int uflag)
+{
+ unsigned long number = 0;
+ unsigned long cutoff;
+ char *pos = (char *) str;
+#if _STRTO_ENDPTR
+ char *fail_char = (char *) str;
+#endif
+ int digit, cutoff_digit;
+ int negative;
+
+ while (isspace(*pos)) { /* skip leading whitespace */
+ ++pos;
+ }
+
+ /* handle optional sign */
+ negative = 0;
+ switch(*pos) {
+ case '-': negative = 1; /* fall through to increment pos */
+ case '+': ++pos;
+ }
+
+ if ((base == 16) && (*pos == '0')) { /* handle option prefix */
+ ++pos;
+#if _STRTO_ENDPTR
+ fail_char = pos;
+#endif
+ if ((*pos == 'x') || (*pos == 'X')) {
+ ++pos;
+ }
+ }
+
+ if (base == 0) { /* dynamic base */
+ base = 10; /* default is 10 */
+ if (*pos == '0') {
+ ++pos;
+ base -= 2; /* now base is 8 (or 16) */
+#if _STRTO_ENDPTR
+ fail_char = pos;
+#endif
+ if ((*pos == 'x') || (*pos == 'X')) {
+ base += 8; /* base is 16 */
+ ++pos;
+ }
+ }
+ }
+
+ if ((base < 2) || (base > 36)) { /* illegal base */
+ goto DONE;
+ }
+
+ cutoff = ULONG_MAX / base;
+ cutoff_digit = ULONG_MAX - cutoff * base;
+
+ while (1) {
+ digit = 40;
+ if ((*pos >= '0') && (*pos <= '9')) {
+ digit = (*pos - '0');
+ } else if (*pos >= 'a') {
+ digit = (*pos - 'a' + 10);
+ } else if (*pos >= 'A') {
+ digit = (*pos - 'A' + 10);
+ } else break;
+
+ if (digit >= base) {
+ break;
+ }
+
+ ++pos;
+#if _STRTO_ENDPTR
+ fail_char = pos;
+#endif
+
+ /* adjust number, with overflow check */
+ if ((number > cutoff)
+ || ((number == cutoff) && (digit > cutoff_digit))) {
+ number = ULONG_MAX;
+ if (uflag) {
+ negative = 0; /* since unsigned returns ULONG_MAX */
+ }
+#if _STRTO_ERRNO
+ errno = ERANGE;
+#endif
+ } else {
+ number = number * base + digit;
+ }
+
+ }
+
+ DONE:
+#if _STRTO_ENDPTR
+ if (endptr) {
+ *endptr = fail_char;
+ }
+#endif
+
+ if (negative) {
+ if (!uflag && (number > ((unsigned long)(-(1+LONG_MIN)))+1)) {
+#if _STRTO_ERRNO
+ errno = ERANGE;
+#endif
+ return (unsigned long) LONG_MIN;
+ }
+ return (unsigned long)(-((long)number));
+ } else {
+ if (!uflag && (number > (unsigned long) LONG_MAX)) {
+#if _STRTO_ERRNO
+ errno = ERANGE;
+#endif
+ return LONG_MAX;
+ }
+ return number;
+ }
+}
+
+#endif
+
+#if L_strtoul
+
+unsigned long strtoul(const char *str, char **endptr, int base)
+{
+ return _strto_l(str, endptr, base, 1);
+}
+
+#endif
+
+#if L_strtol
+
+long strtol(const char *str, char **endptr, int base)
+{
+ return _strto_l(str, endptr, base, 0);
+}
+
+#endif