Import Tcl-core 8.6.6 (as of svn r86089)

compat/strtoul.c

@@ -0,0 +1,214 @@
+/*
+ * strtoul.c --
+ *
+ *	Source code for the "strtoul" library procedure.
+ *
+ * Copyright (c) 1988 The Regents of the University of California.
+ * Copyright (c) 1994 Sun Microsystems, Inc.
+ *
+ * See the file "license.terms" for information on usage and redistribution of
+ * this file, and for a DISCLAIMER OF ALL WARRANTIES.
+ */
+
+#include "tclInt.h"
+
+/*
+ * The table below is used to convert from ASCII digits to a numerical
+ * equivalent. It maps from '0' through 'z' to integers (100 for non-digit
+ * characters).
+ */
+
+static const char cvtIn[] = {
+    0, 1, 2, 3, 4, 5, 6, 7, 8, 9,		/* '0' - '9' */
+    100, 100, 100, 100, 100, 100, 100,		/* punctuation */
+    10, 11, 12, 13, 14, 15, 16, 17, 18, 19,	/* 'A' - 'Z' */
+    20, 21, 22, 23, 24, 25, 26, 27, 28, 29,
+    30, 31, 32, 33, 34, 35,
+    100, 100, 100, 100, 100, 100,		/* punctuation */
+    10, 11, 12, 13, 14, 15, 16, 17, 18, 19,	/* 'a' - 'z' */
+    20, 21, 22, 23, 24, 25, 26, 27, 28, 29,
+    30, 31, 32, 33, 34, 35};
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * strtoul --
+ *
+ *	Convert an ASCII string into an integer.
+ *
+ * Results:
+ *	The return value is the integer equivalent of string. If endPtr is
+ *	non-NULL, then *endPtr is filled in with the character after the last
+ *	one that was part of the integer. If string doesn't contain a valid
+ *	integer value, then zero is returned and *endPtr is set to string.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+unsigned long int
+strtoul(
+    const char *string,		/* String of ASCII digits, possibly preceded
+				 * by white space. For bases greater than 10,
+				 * either lower- or upper-case digits may be
+				 * used. */
+    char **endPtr,		/* Where to store address of terminating
+				 * character, or NULL. */
+    int base)			/* Base for conversion.  Must be less than 37.
+				 * If 0, then the base is chosen from the
+				 * leading characters of string: "0x" means
+				 * hex, "0" means octal, anything else means
+				 * decimal. */
+{
+    register const char *p;
+    register unsigned long int result = 0;
+    register unsigned digit;
+    int anyDigits = 0;
+    int negative=0;
+    int overflow=0;
+
+    /*
+     * Skip any leading blanks.
+     */
+
+    p = string;
+    while (isspace(UCHAR(*p))) {
+	p += 1;
+    }
+    if (*p == '-') {
+        negative = 1;
+        p += 1;
+    } else {
+        if (*p == '+') {
+            p += 1;
+        }
+    }
+
+    /*
+     * If no base was provided, pick one from the leading characters of the
+     * string.
+     */
+
+    if (base == 0) {
+	if (*p == '0') {
+	    p += 1;
+	    if ((*p == 'x') || (*p == 'X')) {
+		p += 1;
+		base = 16;
+	    } else {
+		/*
+		 * Must set anyDigits here, otherwise "0" produces a "no
+		 * digits" error.
+		 */
+
+		anyDigits = 1;
+		base = 8;
+	    }
+	} else {
+	    base = 10;
+	}
+    } else if (base == 16) {
+	/*
+	 * Skip a leading "0x" from hex numbers.
+	 */
+
+	if ((p[0] == '0') && ((p[1] == 'x') || (p[1] == 'X'))) {
+	    p += 2;
+	}
+    }
+
+    /*
+     * Sorry this code is so messy, but speed seems important. Do different
+     * things for base 8, 10, 16, and other.
+     */
+
+    if (base == 8) {
+	unsigned long maxres = ULONG_MAX >> 3;
+
+	for ( ; ; p += 1) {
+	    digit = *p - '0';
+	    if (digit > 7) {
+		break;
+	    }
+	    if (result > maxres) { overflow = 1; }
+	    result = (result << 3);
+	    if (digit > (ULONG_MAX - result)) { overflow = 1; }
+	    result += digit;
+	    anyDigits = 1;
+	}
+    } else if (base == 10) {
+	unsigned long maxres = ULONG_MAX / 10;
+
+	for ( ; ; p += 1) {
+	    digit = *p - '0';
+	    if (digit > 9) {
+		break;
+	    }
+	    if (result > maxres) { overflow = 1; }
+	    result *= 10;
+	    if (digit > (ULONG_MAX - result)) { overflow = 1; }
+	    result += digit;
+	    anyDigits = 1;
+	}
+    } else if (base == 16) {
+	unsigned long maxres = ULONG_MAX >> 4;
+
+	for ( ; ; p += 1) {
+	    digit = *p - '0';
+	    if (digit > ('z' - '0')) {
+		break;
+	    }
+	    digit = cvtIn[digit];
+	    if (digit > 15) {
+		break;
+	    }
+	    if (result > maxres) { overflow = 1; }
+	    result = (result << 4);
+	    if (digit > (ULONG_MAX - result)) { overflow = 1; }
+	    result += digit;
+	    anyDigits = 1;
+	}
+    } else if (base >= 2 && base <= 36) {
+	unsigned long maxres = ULONG_MAX / base;
+
+	for ( ; ; p += 1) {
+	    digit = *p - '0';
+	    if (digit > ('z' - '0')) {
+		break;
+	    }
+	    digit = cvtIn[digit];
+	    if (digit >= ( (unsigned) base )) {
+		break;
+	    }
+	    if (result > maxres) { overflow = 1; }
+	    result *= base;
+	    if (digit > (ULONG_MAX - result)) { overflow = 1; }
+	    result += digit;
+	    anyDigits = 1;
+	}
+    }
+
+    /*
+     * See if there were any digits at all.
+     */
+
+    if (!anyDigits) {
+	p = string;
+    }
+
+    if (endPtr != 0) {
+	/* unsafe, but required by the strtoul prototype */
+	*endPtr = (char *) p;
+    }
+
+    if (overflow) {
+	errno = ERANGE;
+	return ULONG_MAX;
+    }
+    if (negative) {
+	return -result;
+    }
+    return result;
+}