Linker errors when using static variables

[loopj]

When writing code like this:

class BMP085 {
public:
    static BMP085& getInstance() {
        static BMP085 instance;
        return instance;
    }
};

I'm seeing linker errors complaining about missing abi functions __cxa_guard_acquire and __cxa_guard_release:

Sensors.cpp:(.text._ZN6BMP08511getInstanceEv[BMP085::getInstance()]+0x29): undefined reference to `__cxa_guard_acquire'
Sensors.cpp:(.text._ZN6BMP08511getInstanceEv[BMP085::getInstance()]+0x38): undefined reference to `__cxa_guard_release'

Should we add definitions for these functions to abi.h/abi.c to allow use of statics in these situtions? This is what arduino's avr core does:

__extension__ typedef int __guard __attribute__((mode (__DI__)));
extern "C" {
    int __cxa_guard_acquire(__guard *g) {return !*(char *)(g);};
    void __cxa_guard_release(__guard *g) {*(char *)g = 1;};
}

Or am I doing something fundamentally wrong here? Happy to provide a PR.

[loopj]

Looks like there is already a PR open for this at #1586! Closing this issue