ESP8266 cross-linked object initialization

Color.cpp

#include "Color.h"

Color WHITE(0xff, 0xff, 0xff);

Color.h

#ifndef Color_h_
#define Color_h_

#include <Arduino.h>

struct Color {
  uint8_t r, g, b;

  Color(uint8_t r_ = 0, uint8_t g_ = 0, uint8_t b_ = 0)
  : r(r_), g(g_), b(b_) { }
};


extern Color WHITE;

#endif  // Color_h_

output.txt

AVR:
----------------------------------------------------------------
WHITE: 255,255,255
w.getColor(): 255,255,255
wl.getColor(): 255,255,255
wls.getColor(): 255,255,255

GRAY: 85,85,85
g.getColor(): 85,85,85
gl.getColor(): 85,85,85
gls.getColor(): 85,85,85
----------------------------------------------------------------


================================================================

ESP:
----------------------------------------------------------------
WHITE: 255,255,255
w.getColor(): 0,0,0
wl.getColor(): 255,255,255

GRAY: 85,85,85
g.getColor(): 85,85,85
gl.getColor(): 85,85,85
----------------------------------------------------------------

TestGlobals.ino

#include "Color.h"

class Foo {
public:
  Foo () : c(WHITE) { }
  Foo (const Color &c_) : c(c_) { }

  const Color &getColor() const { return c; }
  
private:
  Color c;
};

static Color GRAY(0x55, 0x55, 0x55);

static Foo w;
static Foo g(GRAY);

static void debugPrintColor(const char* name, const Color& c) {
  Serial.print(name); Serial.print(": ");
  Serial.print(c.r); Serial.print(','); Serial.print(c.g); Serial.print(','); Serial.println(c.b);
  Serial.flush();
}


void setup() {
  Serial.begin(115200);

  Foo wl(WHITE);  // l: local
  Foo gl(GRAY);

// Local static fails to link with:
// TestGlobals.cpp.o: In function `debugPrintColor(char const*, Color const&)':
// TestGlobals.ino:23: undefined reference to `__cxa_guard_acquire'
// TestGlobals.ino:23: undefined reference to `__cxa_guard_release'
// TestGlobals.cpp.o: In function `setup':
// TestGlobals.ino:26: undefined reference to `__cxa_guard_acquire'
// TestGlobals.cpp.o: In function `HardwareSerial::begin(unsigned long)':
// .../1.6.5-947-g39819f0/cores/esp8266/HardwareSerial.h:77: undefined reference to `__cxa_guard_release'
// TestGlobals.cpp.o: In function `Foo':
// TestGlobals.ino:6: undefined reference to `__cxa_guard_acquire'
// TestGlobals.ino:6: undefined reference to `__cxa_guard_release'
// collect2: error: ld returned 1 exit status
#ifndef ESP8266 
  static Foo wls(WHITE);  // ls: local static
  static Foo gls(GRAY);
#endif

  debugPrintColor("WHITE", WHITE);
  debugPrintColor("w.getColor()", w.getColor());
  debugPrintColor("wl.getColor()", wl.getColor());
#ifndef ESP8266
  debugPrintColor("wls.getColor()", wls.getColor());
#endif

  Serial.println();

  debugPrintColor("GRAY", GRAY);
  debugPrintColor("g.getColor()", g.getColor());
  debugPrintColor("gl.getColor()", gl.getColor());
#ifndef ESP8266
  debugPrintColor("gls.getColor()", gls.getColor());
#endif

}

void loop() {
  // Do nothing
}