https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99251
Bug ID: 99251
Summary: Strange -Wnonnull warning behaviour with dynamic_cast
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: sirl at gcc dot gnu.org
Target Milestone: ---
With this testcase:
class cl1 {
virtual void m();
};
class cl2 : public cl1 {
public:
int g();
int h();
int i();
};
class cl3 {
cl1 *p;
int g();
int h();
int i();
};
int cl3::g() {
if (!p)
return 0;
cl2 *x = dynamic_cast<cl2 *>(p);
return x->g();
}
int cl3::h() {
if (!p)
return 0;
return (dynamic_cast<cl2 *>(p))->h();
}
int cl3::i() {
if (!p)
return 0;
return dynamic_cast<cl2 *>(p)->i();
}
compiled with g++-trunk@r11-7356 -Wnonnull this warning is issued:
testcase.cpp: In member function 'int cl3::i()':
testcase.cpp:30:36: warning: 'this' pointer is null [-Wnonnull]
30 | return dynamic_cast<cl2 *>(p)->i();
| ^
testcase.cpp:8:7: note: in a call to non-static member function 'int cl2::i()'
8 | int i();
| ^
I believe there should be no warning for cl3::i() like with g++-10.2.
