trying a change that limits arduino.h to not be included in library discovery, this may help compile times. Add dtostrf implementation from deprecated arduino api, we will likely not need this after we add float printing support

Author: Wenn0101

Arduino.h

@@ -5,7 +5,10 @@
 
 // The "Arduino.h" header file is intended to only be included by C++ sources.
 
-#ifndef _ARDUINO_MBED_BRIDGE_ARDUINO_H_
+#if ARDUINO_LIBRARY_DISCOVERY_PHASE == 1
+#define ARDUINO_LIB_DISCOVERY_PHASE
+#endif
+#if !defined(_ARDUINO_MBED_BRIDGE_ARDUINO_H_) && !defined(ARDUINO_LIB_DISCOVERY_PHASE)
 #define _ARDUINO_MBED_BRIDGE_ARDUINO_H_
 
 #include "mbed.h"

core-extend/dtostrf.h

@@ -0,0 +1,33 @@
+/*
+  dtostrf - Emulation for dtostrf function from avr-libc
+  Copyright (c) 2015 Arduino LLC.  All rights reserved.
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library 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
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#pragma once
+
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+char *dtostrf(double val, signed char width, unsigned char prec, char *sout);
+
+#ifdef __cplusplus
+}
+#endif
+

core-implement/dtostrf.c

@@ -0,0 +1,37 @@
+/*
+  dtostrf - Emulation for dtostrf function from avr-libc
+  Copyright (c) 2016 Arduino LLC.  All rights reserved.
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library 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
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+// This is a default implementation for dtostrf function.
+// This file should be used if the standard lib doesn't provide an
+// implementation of dtostrf.
+
+// Create a file called "dtostrf.c" with the following include:
+// #include "api/deprecated-avr-comp/avr/dtostrf.c.impl"
+
+#include <stdio.h>
+
+char *dtostrf (double val, signed char width, unsigned char prec, char *sout) {
+  asm(".global _printf_float");
+
+  char fmt[20];
+  sprintf(fmt, "%%%d.%df", width, prec);
+  sprintf(sout, fmt, val);
+  return sout;
+}
+