keychron_qmk_firmware/common/mbed/xprintf.cpp
2014-07-30 14:07:43 +09:00

47 lines
1.2 KiB
C++

#include <cstdarg>
//#include <stdarg.h>
#include "mbed.h"
#include "mbed/xprintf.h"
#define STRING_STACK_LIMIT 120
/* mbed Serial */
Serial ser(UART_TX, UART_RX);
/* TODO: Need small implementation for embedded */
int xprintf(const char* format, ...)
{
/* copy from mbed/common/RawSerial.cpp */
std::va_list arg;
va_start(arg, format);
int len = vsnprintf(NULL, 0, format, arg);
if (len < STRING_STACK_LIMIT) {
char temp[STRING_STACK_LIMIT];
vsprintf(temp, format, arg);
ser.puts(temp);
} else {
char *temp = new char[len + 1];
vsprintf(temp, format, arg);
ser.puts(temp);
delete[] temp;
}
va_end(arg);
return len;
/* Fail: __builtin_va_arg_pack?
* https://gcc.gnu.org/onlinedocs/gcc-4.3.5/gcc/Constructing-Calls.html#Constructing-Calls
void *arg = __builtin_apply_args();
void *ret = __builtin_apply((void*)(&(ser.printf)), arg, 100);
__builtin_return(ret)
*/
/* Fail: varargs can not be passed to printf
//int r = ser.printf("test %i\r\n", 123);
va_list arg;
va_start(arg, format);
int r = ser.printf(format, arg);
va_end(arg);
return r;
*/
}