emscripten-core/emscripten#2917

Makefile

.PHONY: clean do

CFLAGS=-O0 -m32
EMFLAGS=\
	--memory-init-file 0

do: clean x.o y.o z.o
	emar rc libtest.a y.o
	emar rc libtest.a x.o
	emranlib libtest.a
	EMCC_DEBUG=2 emcc -s EXPORTED_FUNCTIONS="['_aaa']" $(EMFLAGS) $(CFLAGS) -o out.html z.o libtest.a

clean:
	rm -f *.o py/*.o *.a *.js *.html

%.o: %.c
	emcc $(CFLAGS) -c -o $@ $<

x.c

int init_weakref(int a, int b) {
    return a + b;
}

y.c

static int init_weakref(void) {
    return 150;
}

int testy(void) {
    return init_weakref();
}

z.c

extern int init_weakref(int, int);
extern int testy(void);

int aaa(void) {
    return testy() + init_weakref(5, 6);
}