Take the following source code:
struct Foo {
Foo(){}
};
Foo f;
When compiled with clang++, it creates a single symbol for the constructor:
clang++ -c foo.cpp
nm -C foo.o | grep Foo
0000000000000000 W Foo::Foo()
However, when compiled with g++, it creates multiple symbols for the constructor:
g++ -c foo.cpp;
nm -C foo.o | grep Foo
0000000000000000 W Foo::Foo()
0000000000000000 W Foo::Foo()
0000000000000000 n Foo::Foo()
Why would g++ create duplicate weak symbols in the same object file?
My only theory, is that it has to do with inlining, but that's just a guess.
I should note, the mangled names appear as so:
g++ -c foo.cpp; nm foo.o | grep Foo
0000000000000000 W _ZN3FooC1Ev
0000000000000000 W _ZN3FooC2Ev
0000000000000000 n _ZN3FooC5Ev
So although the unmangled names are the same, ZN3FooC1Ev and ZN3FooC2Ev are different.
