[libc] Rewrite strtoul()

The implementation of strtoul() has a partially unknown provenance.
Rewrite this code to avoid potential licensing uncertainty.

Since we now use -ffunction-sections, there is no need to place
strtoull() in a separate file from strtoul().

Signed-off-by: Michael Brown <mcb30@ipxe.org>

4 files changed, 134 insertions, 126 deletions

diff --git a/src/core/base16.c b/src/core/base16.c
index bf9cc21bb..d2977bde1 100644
--- a/src/core/base16.c
+++ b/src/core/base16.c
@@ -20,9 +20,10 @@
 FILE_LICENCE ( GPL2_OR_LATER );
 
 #include <stdint.h>
-#include <stdlib.h>
 #include <stdio.h>
 #include <errno.h>
+#include <assert.h>
+#include <ipxe/string.h>
 #include <ipxe/base16.h>
 
 /** @file
@@ -87,13 +88,13 @@ int hex_decode ( const char *encoded, char separator, void *data, size_t len ) {
 
 		/* Extract digits.  Note that either digit may be NUL,
 		 * which would be interpreted as an invalid value by
-		 * strtoul_charval(); there is therefore no need for an
+		 * digit_value(); there is therefore no need for an
 		 * explicit end-of-string check.
 		 */
-		sixteens = strtoul_charval ( *(encoded++) );
+		sixteens = digit_value ( *(encoded++) );
 		if ( sixteens >= 16 )
 			return -EINVAL;
-		units = strtoul_charval ( *(encoded++) );
+		units = digit_value ( *(encoded++) );
 		if ( units >= 16 )
 			return -EINVAL;
 
diff --git a/src/core/misc.c b/src/core/misc.c
deleted file mode 100644
index 84cfcd803..000000000
--- a/src/core/misc.c
+++ /dev/null
@@ -1,62 +0,0 @@
-/**************************************************************************
-MISC Support Routines
-**************************************************************************/
-
-FILE_LICENCE ( GPL2_OR_LATER );
-
-#include <stdlib.h>
-#include <ctype.h>
-#include <byteswap.h>
-#include <ipxe/in.h>
-#include <ipxe/timer.h>
-
-unsigned int strtoul_charval ( unsigned int charval ) {
-
-	if ( charval >= 'a' ) {
-		charval = ( charval - 'a' + 10 );
-	} else if ( charval >= 'A' ) {
-		charval = ( charval - 'A' + 10 );
-	} else if ( charval <= '9' ) {
-		charval = ( charval - '0' );
-	}
-
-	return charval;
-}
-
-unsigned long strtoul ( const char *p, char **endp, int base ) {
-	unsigned long ret = 0;
-	int negative = 0;
-	unsigned int charval;
-
-	while ( isspace ( *p ) )
-		p++;
-
-	if ( *p == '-' ) {
-		negative = 1;
-		p++;
-	}
-
-	base = strtoul_base ( &p, base );
-
-	while ( 1 ) {
-		charval = strtoul_charval ( *p );
-		if ( charval >= ( unsigned int ) base )
-			break;
-		ret = ( ( ret * base ) + charval );
-		p++;
-	}
-
-	if ( negative )
-		ret = -ret;
-
-	if ( endp )
-		*endp = ( char * ) p;
-
-	return ( ret );
-}
-
-/*
- * Local variables:
- *  c-basic-offset: 8
- * End:
- */
diff --git a/src/core/string.c b/src/core/string.c
index db80d6120..8000efcde 100644
--- a/src/core/string.c
+++ b/src/core/string.c
@@ -366,3 +366,132 @@ char * strndup ( const char *src, size_t max ) {
         }
         return dup;
 }
+
+/**
+ * Calculate digit value
+ *
+ * @v character		Digit character
+ * @ret digit		Digit value
+ *
+ * Invalid digits will be returned as a value greater than or equal to
+ * the numeric base.
+ */
+unsigned int digit_value ( unsigned int character ) {
+
+	if ( character >= 'a' )
+		return ( character - ( 'a' - 10 ) );
+	if ( character >= 'A' )
+		return ( character - ( 'A' - 10 ) );
+	if ( character <= '9' )
+		return ( character - '0' );
+	return character;
+}
+
+/**
+ * Preprocess string for strtoul() or strtoull()
+ *
+ * @v string		String
+ * @v negate		Final value should be negated
+ * @v base		Numeric base
+ * @ret string		Remaining string
+ */
+static const char * strtoul_pre ( const char *string, int *negate, int *base ) {
+
+	/* Skip any leading whitespace */
+	while ( isspace ( *string ) )
+		string++;
+
+	/* Process arithmetic sign, if present */
+	*negate = 0;
+	if ( *string == '-' ) {
+		string++;
+		*negate = 1;
+	} else if ( *string == '+' ) {
+		string++;
+	}
+
+	/* Process base, if present */
+	if ( *base == 0 ) {
+		*base = 10;
+		if ( *string == '0' ) {
+			string++;
+			*base = 8;
+			if ( ( *string & ~0x20 ) == 'X' ) {
+				string++;
+				*base = 16;
+			}
+		}
+	}
+
+	return string;
+}
+
+/**
+ * Convert string to numeric value
+ *
+ * @v string		String
+ * @v endp		End pointer (or NULL)
+ * @v base		Numeric base (or zero to autodetect)
+ * @ret value		Numeric value
+ */
+unsigned long strtoul ( const char *string, char **endp, int base ) {
+	unsigned long value = 0;
+	unsigned int digit;
+	int negate;
+
+	/* Preprocess string */
+	string = strtoul_pre ( string, &negate, &base );
+
+	/* Process digits */
+	for ( ; ; string++ ) {
+		digit = digit_value ( *string );
+		if ( digit >= ( unsigned int ) base )
+			break;
+		value = ( ( value * base ) + digit );
+	}
+
+	/* Negate value if, applicable */
+	if ( negate )
+		value = -value;
+
+	/* Fill in end pointer, if applicable */
+	if ( endp )
+		*endp = ( ( char * ) string );
+
+	return value;
+}
+
+/**
+ * Convert string to numeric value
+ *
+ * @v string		String
+ * @v endp		End pointer (or NULL)
+ * @v base		Numeric base (or zero to autodetect)
+ * @ret value		Numeric value
+ */
+unsigned long long strtoull ( const char *string, char **endp, int base ) {
+	unsigned long long value = 0;
+	unsigned int digit;
+	int negate;
+
+	/* Preprocess string */
+	string = strtoul_pre ( string, &negate, &base );
+
+	/* Process digits */
+	for ( ; ; string++ ) {
+		digit = digit_value ( *string );
+		if ( digit >= ( unsigned int ) base )
+			break;
+		value = ( ( value * base ) + digit );
+	}
+
+	/* Negate value if, applicable */
+	if ( negate )
+		value = -value;
+
+	/* Fill in end pointer, if applicable */
+	if ( endp )
+		*endp = ( ( char * ) string );
+
+	return value;
+}
diff --git a/src/core/strtoull.c b/src/core/strtoull.c
deleted file mode 100644
index 00986eef0..000000000
--- a/src/core/strtoull.c
+++ /dev/null
@@ -1,60 +0,0 @@
-/*
- * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>
- * Copyright (C) 2010 Piotr Jaroszyński <p.jaroszynski@gmail.com>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of the
- * License, or any later version.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- */
-
-FILE_LICENCE ( GPL2_OR_LATER );
-
-#include <stdlib.h>
-#include <ctype.h>
-
-/*
- * Despite being exactly the same as strtoul() except the long long instead of
- * long it ends up being much bigger so provide a separate implementation in a
- * separate object so that it won't be linked in if not used.
- */
-unsigned long long strtoull ( const char *p, char **endp, int base ) {
-	unsigned long long ret = 0;
-	int negative = 0;
-	unsigned int charval;
-
-	while ( isspace ( *p ) )
-		p++;
-
-	if ( *p == '-' ) {
-		negative = 1;
-		p++;
-	}
-
-	base = strtoul_base ( &p, base );
-
-	while ( 1 ) {
-		charval = strtoul_charval ( *p );
-		if ( charval >= ( unsigned int ) base )
-			break;
-		ret = ( ( ret * base ) + charval );
-		p++;
-	}
-
-	if ( negative )
-		ret = -ret;
-
-	if ( endp )
-		*endp = ( char * ) p;
-
-	return ( ret );
-}