https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68738
--- Comment #3 from Rian Quinn <rianquinn at gmail dot com> ---
Just for completeness, here is the exact code out objdump output:
class Blah1
{
public:
Blah1() {}
virtual ~Blah1() {}
virtual int foo() { return 0; }
};
class Blah2 : public Blah1
{
public:
Blah2() {}
~Blah2() {}
int foo() override { return 1; }
};
Blah2 g_blah2;
void
do_something()
{
Blah2 *bp1 = &g_blah2;
Blah2 &bp2 = g_blah2;
bp1->foo(); // Crashes
bp2.foo(); // Does not crash
}
Using the cross-compiler (TARGET=x86_64-elf) you get the following:
0000000000000cd5 <_Z12do_somethingv>:
cd5: 55 push %rbp
cd6: 48 89 e5 mov %rsp,%rbp
cd9: 48 83 ec 10 sub $0x10,%rsp
cdd: 48 8b 05 3c 07 20 00 mov 0x20073c(%rip),%rax # 201420
<_DYNAMIC+0x150>
ce4: 48 89 45 f8 mov %rax,-0x8(%rbp)
ce8: 48 8b 05 31 07 20 00 mov 0x200731(%rip),%rax # 201420
<_DYNAMIC+0x150>
cef: 48 89 45 f0 mov %rax,-0x10(%rbp)
cf3: 48 8b 45 f8 mov -0x8(%rbp),%rax
cf7: 48 8b 00 mov (%rax),%rax
cfa: 48 83 c0 10 add $0x10,%rax
cfe: 48 8b 00 mov (%rax),%rax
d01: 48 8b 55 f8 mov -0x8(%rbp),%rdx
d05: 48 89 d7 mov %rdx,%rdi
d08: ff d0 callq *%rax
d0a: 48 8b 45 f0 mov -0x10(%rbp),%rax
d0e: 48 89 c7 mov %rax,%rdi
d11: e8 5a fe ff ff callq b70 <_ZN5Blah23fooEv@plt>
d16: 90 nop
d17: c9 leaveq
d18: c3 retq
For the Native Ubuntu compiler I get:
0000000000400b58 <_Z12do_somethingv>:
400b58: 55 push %rbp
400b59: 48 89 e5 mov %rsp,%rbp
400b5c: 48 83 ec 10 sub $0x10,%rsp
400b60: 48 c7 45 f0 50 22 60 movq $0x602250,-0x10(%rbp)
400b67: 00
400b68: 48 c7 45 f8 50 22 60 movq $0x602250,-0x8(%rbp)
400b6f: 00
400b70: 48 8b 45 f0 mov -0x10(%rbp),%rax
400b74: 48 8b 00 mov (%rax),%rax
400b77: 48 83 c0 10 add $0x10,%rax
400b7b: 48 8b 00 mov (%rax),%rax
400b7e: 48 8b 55 f0 mov -0x10(%rbp),%rdx
400b82: 48 89 d7 mov %rdx,%rdi
400b85: ff d0 callq *%rax
400b87: 48 8b 45 f8 mov -0x8(%rbp),%rax
400b8b: 48 89 c7 mov %rax,%rdi
400b8e: e8 9f 06 00 00 callq 401232 <_ZN5Blah23fooEv>
400b93: 90 nop
400b94: c9 leaveq
400b95: c3 retq
The flags I am passing to the cross-compiler are:
-fpic -fno-rtti -fno-sized-deallocation -fno-exceptions -fno-use-cxa-atexit
-fno-threadsafe-statics
- Rian
