https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92708
Bug ID: 92708
Summary: [Issue] dynamic_cast unexpected behavior in my code
Product: gcc
Version: 6.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: akhilesh.k at samsung dot com
Target Milestone: ---
Hello
In below code I used class A and a class B which is derived from A. Now, I did
dynamic_cast I got segmentation fault. same behaviors I observed on ARM also.
is this expected behavior ? or some limitation.
As per below link seems some limitation with shared libraries.
https://gcc.gnu.org/faq.html#dso
akhilesh.k@DELL-BUILD10:$ cat hello.c
#include <stdio.h>
#include <iostream>
using namespace std;
class A
{
public:
A(){}
virtual ~A(){};
};
class B : public A
{
public:
B(){}
virtual ~B(){}
};
int main()
{
A *pa, *pa2;
B *pb, *pb2;
pa = new A;
pb = new B;
delete pb;
pa2 = dynamic_cast<A*>(pb);
pb2 = dynamic_cast<B*>(pb);
pb2 = dynamic_cast<B*>(pa2);
printf("pb2 = %p\n", pb2);
pb2 = dynamic_cast<B*>(pa);
printf("pb2 = %p\n", pb2);
delete pa;
delete pb;
return 0;
}
akhilesh.k@DELL-BUILD10:$ g++ -g hello.c
akhilesh.k@DELL-BUILD10:$ gdb a.out
GNU gdb (Ubuntu 7.7.1-0ubuntu5~14.04.3) 7.7.1
Copyright (C) 2014 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
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and "show warranty" for details.
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Type "show configuration" for configuration details.
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Reading symbols from a.out...done.
(gdb) r
Starting program: /data2/2706/akhilesh.k/a.out
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff7b33156 in __dynamic_cast () from
/usr/lib/x86_64-linux-gnu/libstdc++.so.6
(gdb) bt
#0 0x00007ffff7b33156 in __dynamic_cast () from
/usr/lib/x86_64-linux-gnu/libstdc++.so.6
#1 0x000000000040095d in main () at hello.c:29
(gdb)
