A number of updates from Manuel Novoa III. Things look good...

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