Add support for 64-bit number printing (SmingHub#1822)

Adds support to `Print` and `String` classes for `long long` and `unsigned long long` numbers using revised `stringconversion` routines.
`Print` class revised to use `stringconversion` routines for consistency with `String`.
Note that Print used its own code for this which produced hex in uppercase, rather than lowercase.

`stringconversion` updates:

* Fix incorrect `width` parameter passing in `ultoa_wp()`
* Move alias functions into header as static inline (removes redundant function calls)
* Eliminate code duplication by calling `ultoa_wp` from `ltoa_wp`
* Avoid un-necessary use of strlen in conversions
* Check `base` parameter and default to base 10 if invalid - this was in Print.cpp but moving it here ensures it's applied consistently
* Add 64-bit string conversion functions for `long long` and `unsigned long long`.

Author: mikee47

Sming/System/include/stringconversion.h

@@ -17,20 +17,75 @@
 extern "C" {
 #endif
 
-int atoi(const char *nptr); // Already implemented
+/*
+ * Since C does not support default func parameters, we define inline versions which
+ * translate to ltoa_wp, ultoa_wp, lltoa_wp and ulltoa_wp functions.
+ */
 
 extern char* ltoa_wp(long val, char* buffer, int base, int width, char pad);
-extern char* ltoa_w (long, char*, int, int width);
-extern char* ltoa (long, char*, int);
+
+static inline char* ltoa_w(long val, char* buffer, int base, int width)
+{
+	return ltoa_wp(val, buffer, base, width, ' ');
+}
+
+static inline char* ltoa (long val, char* buffer, int base)
+{
+	return ltoa_wp(val, buffer, base, 0, ' ');
+}
+
+static inline char* itoa (int val, char* buffer, int base)
+{
+	return ltoa_wp(val, buffer, base, 0, ' ');
+}
 
 extern char* ultoa_wp(unsigned long val, char* buffer, unsigned int base, int width, char pad);
-extern char* ultoa_w(unsigned long val, char* buffer, unsigned int base, int width);
-extern char* ultoa(unsigned long val, char* buffer, unsigned int base);
+
+static inline char* ultoa_w(unsigned long val, char* buffer, unsigned int base, int width)
+{
+	return ultoa_wp(val, buffer, base, width, ' ');
+}
+
+static inline char* ultoa(unsigned long val, char* buffer, unsigned int base)
+{
+	return ultoa_wp(val, buffer, base, 0, ' ');
+}
+
+extern char* lltoa_wp(long long val, char* buffer, int base, int width, char pad);
+
+static inline char* lltoa_w(long long val, char* buffer, int base, int width)
+{
+	return lltoa_wp(val, buffer, base, width, ' ');
+}
+
+static inline char* lltoa(long long val, char* buffer, int base)
+{
+	return lltoa_wp(val, buffer, base, 0, ' ');
+}
+
+
+extern char* ulltoa_wp(unsigned long long val, char* buffer, unsigned int base, int width, char pad);
+
+static inline char* ulltoa_w(unsigned long long val, char* buffer, unsigned int base, int width)
+{
+	return ulltoa_wp(val, buffer, base, width, ' ');
+}
+
+static inline char* ulltoa(unsigned long long val, char* buffer, unsigned int base)
+{
+	return ulltoa_wp(val, buffer, base, 0, ' ');
+}
+
 
 extern char* itoa(int, char*, int);
 
 extern char *dtostrf_p(double floatVar, int minStringWidthIncDecimalPoint, int numDigitsAfterDecimal, char *outputBuffer, char pad);
-extern char *dtostrf(double floatVar, int minStringWidthIncDecimalPoint, int numDigitsAfterDecimal, char *outputBuffer);
+
+static inline char *dtostrf(double floatVar, int minStringWidthIncDecimalPoint, int numDigitsAfterDecimal, char *outputBuffer)
+{
+	return dtostrf_p(floatVar, minStringWidthIncDecimalPoint, numDigitsAfterDecimal, outputBuffer, ' ');
+}
+
 long atol(const char *nptr);
 extern long os_strtol(const char* str, char** endptr, int base);
 extern double os_strtod(const char* str, char** endptr);

Sming/System/stringconversion.cpp

@@ -14,86 +14,97 @@
 #include "stringconversion.h"
 #include "stringutil.h"
 
-//Since C does not support default func parameters, keep this function as used by framework
-//and create extended _w funct to handle width
-char* ltoa(long val, char* buffer, int base)
-{
-	return ltoa_w(val, buffer, base, 0);
-}
-
-char* itoa (int, char*, int) __attribute__((alias("ltoa")));
 
-char* ltoa_w(long val, char* buffer, int base, int width)
+char* ltoa_wp(long val, char* buffer, int base, int width, char pad)
 {
-	return ltoa_wp(val, buffer, base, width, ' ');
+	if(val < 0) {
+		*buffer++ = '-';
+		val = -val;
+	}
+	return ultoa_wp((unsigned long)val, buffer, base, width, pad);
 }
 
-char* ltoa_wp(long val, char* buffer, int base, int width, char pad)
+char* ultoa_wp(unsigned long val, char* buffer, unsigned int base, int width, char pad)
 {
-	int i = 38, p = 0;
-	char buf[40] = {0};
-	bool ngt = val < 0;
-	if (ngt) val = -val;
+	char buf[40];
+	constexpr int nulpos = sizeof(buf) - 1;
+	buf[nulpos] = '\0';
 
-	for(; val && i ; --i, p++, val /= base)
-		buf[i] = hexchar(val % base);
-	if (p == 0) buf[i--] = '0'; // case for zero
+	// prevent crash if called with base == 1
+	if(base < 2 || base > 16) {
+		base = 10;
+	}
 
-	if (ngt)
-		buf[i--] = '-';
+	int i = nulpos - 1;
+	int p = 0;
+	for(; val != 0 && i != 0; --i, p++, val /= base) {
+		buf[i] = hexchar(val % base);
+	}
+	if (p == 0) {
+		buf[i--] = '0'; // case for zero
+	}
 
 	if(width != 0)
 	{
-		width -= strlen(&buf[i+1]);
+		width -= (nulpos - i - 1);
 		if(width > 0)
 		{
 			memset(buffer, pad, width);
 		}
-		else width = 0;
+		else {
+			width = 0;
+		}
 	}
+	memcpy(buffer + width, &buf[i+1], nulpos - i);
 
-	strcpy(buffer + width, &buf[i+1]);
 	return buffer;
 }
 
-//Since C does not support default func parameters, keep this function as used by framework
-//and create extended _w funct to handle width
-char* ultoa(unsigned long val, char* buffer, unsigned int base)
+char* lltoa_wp(long long val, char* buffer, int base, int width, char pad)
 {
-	return ultoa_w(val, buffer, base, 0);
+	if(val < 0) {
+		*buffer++ = '-';
+		val = -val;
+	}
+	return ulltoa_wp((unsigned long long)val, buffer, base, width, pad);
 }
 
-char* ultoa_w(unsigned long val, char* buffer, unsigned int base, int width)
-{
-	return ultoa_wp(val, buffer, base, 0, ' ');
-}
-char* ultoa_wp(unsigned long val, char* buffer, unsigned int base, int width, char pad)
+char* ulltoa_wp(unsigned long long val, char* buffer, unsigned int base, int width, char pad)
 {
-	int i = 38, p = 0;
-	char buf[40] = {0};
+	char buf[80];
+	constexpr int nulpos = sizeof(buf) - 1;
+	buf[nulpos] = '\0';
+
+	// prevent crash if called with base == 1
+	if(base < 2) {
+		base = 10;
+	}
 
-	for(; val && i ; --i, p++, val /= base)
+	int i = nulpos - 1;
+	int p = 0;
+	for(; val != 0 && i != 0; --i, p++, val /= base) {
 		buf[i] = hexchar(val % base);
-	if (p == 0) buf[i--] = '0'; // case for zero
+	}
+	if (p == 0) {
+		buf[i--] = '0'; // case for zero
+	}
 
 	if(width != 0)
 	{
-		width -= strlen(&buf[i+1]);
+		width -= (nulpos - i - 1);
 		if(width > 0)
 		{
 			memset(buffer, pad, width);
 		}
-		else width = 0;
+		else {
+			width = 0;
+		}
 	}
-	strcpy(buffer + width, &buf[i+1]);
+	memcpy(buffer + width, &buf[i+1], nulpos - i);
 
 	return buffer;
 }
 
-char *dtostrf(double floatVar, int minStringWidthIncDecimalPoint, int numDigitsAfterDecimal, char *outputBuffer)
-{
-	return dtostrf_p(floatVar, minStringWidthIncDecimalPoint, numDigitsAfterDecimal, outputBuffer, ' ');
-}
 // Author zitron: http://forum.arduino.cc/index.php?topic=37391#msg276209
 // modified by ADiea: remove dependencies strcat, floor, round; reorganize+speedup code
 char *dtostrf_p(double floatVar, int minStringWidthIncDecimalPoint, int numDigitsAfterDecimal, char *outputBuffer, char pad)