https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84044
Bug ID: 84044
Summary: Spurious -Wodr warning with -flto
Product: gcc
Version: 7.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: lto
Assignee: unassigned at gcc dot gnu.org
Reporter: geoffrey at allott dot email
CC: marxin at gcc dot gnu.org
Target Milestone: ---
a.cpp
=====
struct A {
virtual ~A();
};
A::~A() {}
b.cpp
=====
struct A {
virtual ~A();
};
struct B {
A a;
A get();
};
A B::get() {
return a;
}
Makefile
========
main: a.cpp b.cpp
$(CXX) a.cpp -c -fno-semantic-interposition -fpic -flto
$(CXX) b.cpp -c -flto -O1
$(CXX) a.o b.o
This results in:
b.cpp:1:8: warning: virtual table of type ‘struct A’ violates one definition
rule [-Wodr]
struct A {
^
a.cpp:1:8: note: the conflicting type defined in another translation unit
struct A {
^
a.cpp:5:1: note: virtual method ‘__base_dtor ’
A::~A() {}
^
a.cpp:5:1: note: ought to match virtual method ‘__base_dtor ’ but does not
Note that even something as simple as inlining the definition of the destructor
or the `get` function cause the warning to go away. All of the flags are
necessary to reproduce the error.
