Modify based on code review

Author: sgbihu

cores/arduino/printk.cpp

@@ -29,175 +29,24 @@
  */
 
 #include <stdarg.h>
+#include <cstdio>
 #include "UARTClass.h"
 
 extern "C" void printk(const char *fmt, va_list args);
-int __vsnprintf(char *dest, int size, const char *fmt, va_list args)
-{
-    int might_format = 0;
-    int len = 0;
-    char lastchar = 0;
-    bool binary_format = false;
-
-    if (!dest || !size)
-        return 0;
-
-    while (*fmt && len < size) {
-        if (!might_format) {
-            if (*fmt == '\n' && lastchar != '\r') {
-                if (len < size) {
-                    lastchar = *dest++ = '\r', len++;
-                    continue;
-                } else
-                    break;
-            } else if (*fmt != '%') {
-                if (len < size)
-                    lastchar = *dest++ = *fmt, len++;
-                else
-                    break;
-            } else
-                might_format = 1;
-        } else {
-            if (*fmt == '%') {
-                if (len < size)
-                    *dest++ = '%', len++;
-                else
-                    break;
-                might_format = 0;
-            } else {
-                switch (*fmt) {
-                case '0':
-                case '1':
-                    might_format |= 2;
-                    goto still_format;
-                    break;
-                case '2':
-                    might_format |= 4;
-                    goto still_format;
-                    break;
-                case '4':
-                    might_format |= 8;
-                    goto still_format;
-                    break;
-                case 'b':
-                    binary_format = true;
-                    goto still_format;
-                    break;
-                case 'd':
-                case 'i':
-                case 'u':
-                    if (!binary_format) {
-                        unsigned long num =
-                            va_arg(args,
-                                   unsigned long);
-                        unsigned long pos = 999999999;
-                        unsigned long remainder = num;
-                        int found_largest_digit = 0;
-
-                        if (*fmt != 'u'
-                            && (num & (1 << 31))) {
-                            if (len < size)
-                                *dest++ = '-',
-                                len++;
-                            num = (~num) + 1;
-                            remainder = num;
-                        }
-                        while (pos >= 9) {
-                            if (found_largest_digit
-                                || remainder >
-                                pos) {
-                                found_largest_digit
-                                    = 1;
-                                if (len < size)
-                                    *dest++ = (char)((remainder / (pos + 1)) + 48),
-                                    len++;
-                                else
-                                    break;
-                            }
-                            remainder %= (pos + 1);
-                            pos /= 10;
-                        }
-                        if (len < size)
-                            *dest++ = (char)(remainder + 48),
-                            len++;
-                        break;
-                    }
-                case 'x':
-                case 'X':
-                case 'p': {
-                    unsigned long num =
-                        va_arg(args, unsigned long);
-                    int sz = sizeof(num) * 2;
-
-                    if (might_format & 8) {
-                        sz = 4;
-                    } else if (might_format & 4) {
-                        sz = 2;
-                    } else if (might_format & 2) {
-                        sz = 1;
-                    }
-                    for (; sz; sz--) {
-                        char nibble;
-                        if (!binary_format) {
-                            nibble = (num >> ((sz - 1) << 2) & 0xf);
-                            nibble += nibble > 9 ? 87 : 48;
-                        } else {
-                            nibble = (num >> ((sz - 1) << 3) & 0xff);
-                        }
-                        if (len < size)
-                            *dest++ = nibble,
-                            len++;
-                        else
-                            break;
-                    }
-                    break;
-                }
-                case 's': {
-                    char *s = va_arg(args, char *);
-                    while (*s)
-                        if (len < size)
-                            *dest++ =
-                                *s++, len++;
-                        else
-                            break;
-                    break;
-                }
-                case 'c': {
-                    char c = va_arg(args, int);
-                    if (len < size)
-                        *dest++ = c, len++;
-                    break;
-                }
-                default:
-                    if (len < size)
-                        *dest++ = '%', len++;
-                    if (len < size)
-                        *dest++ = *fmt, len++;
-                    break;
-                }
-                might_format = 0;
-still_format:
-                (void)might_format;
-            }
-        }
-        ++fmt;
-    }
-    *dest = '\0';
-    return len;
-}
-
 extern UARTClass Serial1;
 #define PRINTK_BUFSIZ 256
+
 void printk(const char *fmt, va_list args)
 {
 #ifdef CONFIGURE_DEBUG_CORELIB_ENABLED
     int len = 0;
 
     char tmp[PRINTK_BUFSIZ];
 
-    len = __vsnprintf(tmp, PRINTK_BUFSIZ, fmt, args);
+    len = vsnprintf(tmp, PRINTK_BUFSIZ, fmt, args);
 
     tmp[len] = '\0';
     Serial1.println(tmp);
 #endif
 }
+