Merge pull request #1 from xxxajk/master

Add missing _P versions of printf family

teensy3/avr/pgmspace.h

 #define strspn_P(str, chrs) strspn((str), (chrs))
 #define strstr_P(a, b) strstr((a), (b))
 #define sprintf_P(s, f, ...) sprintf((s), (f), __VA_ARGS__)
+#define vfprintf_P(s, f, ...) vfprintf((s), (f), __VA_ARGS__)
+#define printf_P(f, ...) printf((f), __VA_ARGS__)
+#define snprintf_P(s, n, f, ...) ((s), (n), (f), __VA_ARGS__)
+#define vsprintf_P(s, f, ...) ((s), (f),__VA_ARGS__)
+#define vsnprintf_P(s, n, f, ...) ((s), (n), (f),__VA_ARGS__)
+#define fprintf_P(s, f, ...) ((s), (f),__VA_ARGS__)
 
 #define pgm_read_byte(addr) (*(const unsigned char *)(addr))
 #define pgm_read_word(addr) (*(const unsigned short *)(addr))

teensy3/mk20dx128.c

 	return prev;
 }
 
+__attribute__((weak)) 
 int _read(int file, char *ptr, int len)
 {
 	return 0;
 }
 
+__attribute__((weak)) 
 int _write(int file, char *ptr, int len)
 {
 	return 0;
 }
 
+__attribute__((weak)) 
 int _close(int fd)
 {
 	return -1;
 
 #include <sys/stat.h>
 
+__attribute__((weak)) 
 int _fstat(int fd, struct stat *st)
 {
 	st->st_mode = S_IFCHR;
 	return 0;
 }
 
+__attribute__((weak)) 
 int _isatty(int fd)
 {
 	return 1;
 }
 
+__attribute__((weak)) 
 int _lseek(int fd, long long offset, int whence)
 {
 	return -1;
 }
 
+__attribute__((weak)) 
 void _exit(int status)
 {
 	while (1);
 }
 
+__attribute__((weak)) 
 void __cxa_pure_virtual()
 {
 	while (1);
 }
 
+__attribute__((weak)) 
 int __cxa_guard_acquire (int *g) 
 {
 	return 1;
 }
 
+__attribute__((weak)) 
 void __cxa_guard_release(int *g)
 {
 }