Hi
I am trying to compile a quite large software system with a new
compiler. During that attempt I am facing problems during the link
phase, and I have traced it down to the following construct:
test.cc:
class Foo
{
public:
virtual ~Foo();
};
class Bar : public Foo
{
public:
virtual ~Bar() {};
};
If I compile this unit all of the previous compilers I have tried will
generate _no_ symbols, since I don't actually use anything here. The
new compiler I have tried gives me:
Undefined symbols from test.o:
typeid<Foo>
Foo::~Foo()
Class tables [Vtable] dependent on key function:
"__versioned_ty pe_info::~__ver sioned_type_inf o()"
So the question is as simple as: Is this a "bug" in the new compiler I
have used, or is it "allowed" to do this according to the
specification.. .
(In my "real" program the classes reside in separate header files
included by a lot of different "modules" in my system...)
Trond 3 2855 tr**********@gm ail.com wrote:
I am trying to compile a quite large software system with a new
compiler. During that attempt I am facing problems during the link
phase, and I have traced it down to the following construct:
test.cc:
class Foo
{
public:
virtual ~Foo();
A virtual function will be defined or declared pure or both. You
cannot declare a function virtual without providing its definition
somewhere. Period.
};
class Bar : public Foo
{
public:
virtual ~Bar() {};
};
If I compile this unit all of the previous compilers I have tried will
generate _no_ symbols, since I don't actually use anything here. The
new compiler I have tried gives me:
Undefined symbols from test.o:
typeid<Foo>
Foo::~Foo()
Class tables [Vtable] dependent on key function:
"__versioned_ty pe_info::~__ver sioned_type_inf o()"
So the question is as simple as: Is this a "bug" in the new compiler I
have used, or is it "allowed" to do this according to the
specification.. .
It is not allowed to have a virtual function that is not pure without
a definition. You can only omit the definition of a virtual function
iff you declare it pure.
(In my "real" program the classes reside in separate header files
included by a lot of different "modules" in my system...)
That doesn't matter.
V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask
Victor Bazarov wrote:
So the question is as simple as: Is this a "bug" in the new compiler I
have used, or is it "allowed" to do this according to the
specification.. .
It is not allowed to have a virtual function that is not pure without
a definition. You can only omit the definition of a virtual function
iff you declare it pure.
(In my "real" program the classes reside in separate header files
included by a lot of different "modules" in my system...)
That doesn't matter.
This was _exactly_ the kind of information I was looking for :-)
regards,
Trond
In article <11************ **********@b28g 2000cwb.googleg roups.com>,
<tr**********@g mail.comwrote:
>I am trying to compile a quite large software system with a new compiler. During that attempt I am facing problems during the link phase, and I have traced it down to the following construct:
test.cc: class Foo {
public:
virtual ~Foo(); };
class Bar : public Foo {
public:
virtual ~Bar() {}; };
If I compile this unit all of the previous compilers I have tried will generate _no_ symbols, since I don't actually use anything here. The new compiler I have tried gives me:
Undefined symbols from test.o:
typeid<Foo>
Foo::~Foo()
Class tables [Vtable] dependent on key function: "__versioned_t ype_info::~__ve rsioned_type_in fo()"
So the question is as simple as: Is this a "bug" in the new compiler I have used, or is it "allowed" to do this according to the specification. ..
(In my "real" program the classes reside in separate header files included by a lot of different "modules" in my system...)
I don't have my standard in front of me, but I'm fairly
certain that it says that the virtuals need to be defined
but that a diagnostic is not required.
--
Greg Comeau / 20 years of Comeauity! Intel Mac Port now in alpha!
Comeau C/C++ ONLINE == http://www.comeaucomputing.com/tryitout
World Class Compilers: Breathtaking C++, Amazing C99, Fabulous C90.
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