https://gcc.gnu.org/bugzilla/show_bug.cgi?id=45065
--- Comment #4 from Eric Gallager <egallager at gcc dot gnu.org> ---
(In reply to Eric Gallager from comment #3)
> (In reply to Dean Edmonds from comment #0)
> > Compiling with -fvisibility=hidden and -fvisibility-inlines-hidden.
> >
> > I have a Base class with default visibility which contains two virtual
> > methods, one inlined and the other not. A Derived class with hidden
> > visibility overrides the non-inlined method and doesn't touch the inlined
> > one. If the declaration of the overridden method appears *before* the
> > Derived's virtual destructor then the object file for Derived weakly exports
> > the Base class's inlined method. But if the declaration appears *after*
> > Derived's virtual destructor then the object for Derived doesn't export the
> > Base class's inlined method at all.
> >
> > Given that I'm compiling with -fvisibility-inlines-hidden I *think* that
> > means that the Base class's inlined method should never be exported. Even if
> > I'm wrong about that, surely it should not matter the order in which the
> > Derived class's methods are declared.
> >
> > Here's an example which demonstrates the problem:
> >
> > class __attribute__ ((visibility("default"))) Base
> > {
> > public:
> > Base();
> > virtual ~Base();
> > virtual void func() const;
> > virtual void inlineFunc() {}
> > };
> >
> > class Derived : public Base
> > {
> > public:
> > Derived();
> > void func() const;
> > virtual ~Derived();
> > };
> >
> > void Derived::func() const
> > {}
> >
> > Compiled on OSX 10.6.4 with g++ 4.2.1, using the following command:
> >
> > g++-4.2 -Wall -c -arch x86_64 -fvisibility=hidden
> > -fvisibility-inlines-hidden -O3 -m64 -isysroot
> > /Developer/SDKs/MacOSX10.6.sdk -mmacosx-version-min=10.6 -o Derived.o
> > Derived.cpp
> >
> > Looking at the object file using 'nm -m Derived.o | grep inlineFunc' gives:
> >
> > 0000000000000010 (__TEXT,__textcoal_nt) weak private external
> > __ZN6Common10inlineFuncEv
> > 0000000000000098 (__TEXT,__eh_frame) weak private external
> > __ZN6Common10inlineFuncEv.eh
> >
> > If I move the declaration of Derived::func() so that it comes after
> > ~Derived() then 'nm -m Derived.o | grep inlineFunc' returns nothing.
> >
> >
>
> On 10.5 with gcc8, the grep only returns one line:
>
> $ /usr/local/bin/g++ -Wall -c -arch x86_64 -fvisibility=hidden
> -fvisibility-inlines-hidden -O3 -m64 -isysroot
> /Developer/SDKs/MacOSX10.5.sdk -mmacosx-version-min=10.5 -Wextra -pedantic
> -o 45065.o 45065.cc
> $ nm -m 45065.o | grep inlineFunc
> 0000000000000010 (__TEXT,__textcoal_nt) weak private external
> __ZN4Base10inlineFuncEv
>
> The difference is no version suffixed with '.eh' so I think it's a 10.5 to
> 10.6 difference.
huh, that's strange, I checked on 10.6 and I don't get the '.eh'-suffixed
version here either, so I guess it isn't a 10.5 vs. 10.6 difference after
all... what version cctools were you using?
>
> > I see similar behaviour on GNU/Linux (2.6.30.9-96.fc11.x86_64) using g++
> > 4.4.1. Compiling with this command:
> >
> > g++ -Wall -c -fvisibility=hidden -fvisibility-inlines-hidden -O3 -m64 -o
> > Derived.o Derived.cpp
> >
> > and using 'objdump -t Derived.o | grep inlineFunc' to inspect the result
> > gives this when Derived::func() is declared before ~Derived():
> >
> > 0000000000000000 l d .text._ZN4Base10inlineFuncEv 0000000000000000
> > .text._ZN4Base10inlineFuncEv
> > 0000000000000000 w F .text._ZN4Base10inlineFuncEv 0000000000000002
> > .hidden _ZN4Base10inlineFuncEv
> >
> > and gives nothing when Derived::func() is declared after ~Derived().
>
> (In reply to Paolo Carlini from comment #2)
> > I can confirm the behavior with today's mainline. And seems weird indeed.
>
> Changing status to NEW then since it's confirmed.
