extern Óë attribute µÄ hidden

DevNet_17_82_sles10sp1:attribute> readelf  -a libfoo.so  | grep OBJECT | grep foo
    11: 000015e0     4 OBJECT  GLOBAL DEFAULT   19 _foo
    51: 000015e0     4 OBJECT  LOCAL  HIDDEN   19 foo
    55: 000015e0     4 OBJECT  GLOBAL DEFAULT   19 _foo

DevNet_17_82_sles10sp1:attribute> cat ./foo.c 
int _foo = 5;

extern int foo __attribute__(( alias("_foo"), visibility("hidden")));

DevNet_17_82_sles10sp1:attribute> gcc -shared -o libfoo.so foo.c