From 5e55e1c65199b41f31286a78e4bb577806056afa Mon Sep 17 00:00:00 2001
From: uz <uz@b7a2c559-68d2-44c3-8de9-860c34a00d81>
Date: Tue, 15 Sep 2009 21:45:25 +0000
Subject: [PATCH] Added a (currently untested) strtoul implementation. strtol
 and strtoul should probably get merged somehow, because they share quite some
 code.

git-svn-id: svn://svn.cc65.org/cc65/trunk@4180 b7a2c559-68d2-44c3-8de9-860c34a00d81
---
 libsrc/common/Makefile  |   1 +
 libsrc/common/strtoul.c | 119 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 120 insertions(+)
 create mode 100644 libsrc/common/strtoul.c

diff --git a/libsrc/common/Makefile b/libsrc/common/Makefile
index 0a792b59b..0ef066888 100644
--- a/libsrc/common/Makefile
+++ b/libsrc/common/Makefile
@@ -74,6 +74,7 @@ C_OBJS =	_afailed.o	        \
                 strftime.o              \
 		strtok.o	        \
                 strtol.o                \
+                strtoul.o               \
 		strxfrm.o	        \
                 system.o                \
                 timezone.o
diff --git a/libsrc/common/strtoul.c b/libsrc/common/strtoul.c
new file mode 100644
index 000000000..15b01ec23
--- /dev/null
+++ b/libsrc/common/strtoul.c
@@ -0,0 +1,119 @@
+#include <limits.h>
+#include <ctype.h>
+#include <errno.h>
+#include <stdlib.h>
+
+
+
+unsigned long __fastcall__ strtoul (const char* nptr, char** endptr, int base)
+/* Convert a string to a long unsigned int */
+{
+    register const char* S          = nptr;
+    unsigned long        Val        = 0;
+    unsigned char        Minus      = 0;
+    unsigned char        Ovf        = 0;
+    unsigned             CvtCount   = 0;
+    unsigned char        DigitVal;
+    unsigned long        MaxVal;
+    unsigned char        MaxDigit;
+
+
+    /* Skip white space */
+    while (isspace (*S)) {
+        ++S;
+    }
+
+    /* Check for leading + or - sign */
+    switch (*S) {
+        case '-':
+            Minus = 1;
+            /* FALLTHROUGH */
+        case '+':
+            ++S;
+    }
+
+    /* If base is zero, we may have a 0 or 0x prefix. If base is 16, we may
+     * have a 0x prefix.
+     */
+    if (base == 0) {
+        if (*S == '0') {
+            ++S;
+            if (*S == 'x' || *S == 'X') {
+                ++S;
+                base = 16;
+            } else {
+                base = 8;
+            }
+        } else {
+            base = 10;
+        }
+    } else if (base == 16 && *S == '0' && (S[1] == 'x' || S[1] == 'X')) {
+        S += 2;
+    }
+
+    /* Determine the maximum valid number and (if the number is equal to this
+     * value) the maximum valid digit.
+     */
+    MaxDigit = ULONG_MAX % base;
+    MaxVal   = ULONG_MAX / base;
+
+    /* Convert the number */
+    while (1) {
+
+        /* Convert the digit into a numeric value */
+        if (isdigit (*S)) {
+            DigitVal = *S - '0';
+        } else if (isupper (*S)) {
+            DigitVal = *S - ('A' - 10);
+        } else if (islower (*S)) {
+            DigitVal = *S - ('a' - 10);
+        } else {
+            /* Unknown character */
+            break;
+        }
+
+        /* Don't accept a character that doesn't match base */
+        if (DigitVal >= base) {
+            break;
+        }
+
+        /* Don't accept anything that makes the final value invalid */
+        if (Val > MaxVal || (Val == MaxVal && DigitVal > MaxDigit)) {
+            Ovf = 1;
+        }
+
+        /* Calculate the next value if digit is not invalid */
+        if (Ovf == 0) {
+            Val = (Val * base) + DigitVal;
+            ++CvtCount;
+        }
+
+        /* Next character from input */
+        ++S;
+    }
+
+    /* Store the end pointer. If no conversion was performed, the value of
+     * nptr is returned in endptr.
+     */
+    if (endptr) {
+        if (CvtCount > 0) {
+            *endptr = (char*) S - 1;
+        } else {
+            *endptr = (char*) nptr;
+        }
+    }
+
+    /* Handle overflow */
+    if (Ovf) {
+        errno = ERANGE;
+        return ULONG_MAX;
+    }
+
+    /* Return the result */
+    if (Minus) {
+        return (unsigned long) -(long)Val;
+    } else {
+        return Val;
+    }
+}
+
-- 
2.39.2