https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67735
Bug ID: 67735
Summary: internal compiler error while trying to use
__direct_bases to create parallel hierarchy of classes
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: piotrwn1 at gmail dot com
Target Milestone: ---
When used new extensions of __direct_bases to create parallel hierarchy of
classes - I got the internal compiler error.
Link to online compiler with this issue:
http://melpon.org/wandbox/permlink/JJiMLfGJWth94oV2#wandbox-resultwindow-code-body-5
I know this is about experimental feature - but since asked then - here you
are:
#include <type_traits>
template <typename T>
class CallUp : public CallUp<__direct_bases(T)>...
{
public:
CallUp(T* obj) : CallUp<__direct_bases(T)>(obj)..., obj(obj)
{
}
~CallUp()
{
obj->resetThis();
}
private:
T* obj;
};
template <typename T>
auto callUp(T* obj)
{
return CallUp<T>(obj);
}
class Foo0
{
public:
using Base = NoBase;
void resetThis()
{
std::cout << "reset Foo0\n";
}
void reset()
{
callUp(this);
}
};
class Foo1 : public Foo0
{
public:
using Base = Foo0;
void resetThis()
{
std::cout << "reset Foo1\n";
}
void reset()
{
callUp(this);
}
};
class Foo2 : public Foo1
{
public:
using Base = Foo1;
void resetThis()
{
std::cout << "reset Foo2\n";
}
void reset()
{
callUp(this);
}
};
int main() {
Foo2 foo2;
foo2.reset();
}
The output:
prog.cc:4:48: internal compiler error: Segmentation fault
class CallUp : public CallUp<__direct_bases(T)>...
^
0xa6c33f crash_signal
/home/heads/gcc/gcc-source/gcc/toplev.c:353
0x5cd1b2 xref_basetypes(tree_node*, tree_node*)
/home/heads/gcc/gcc-source/gcc/cp/decl.c:12866
0x638e04 cp_parser_class_head
/home/heads/gcc/gcc-source/gcc/cp/parser.c:21382
0x638e04 cp_parser_class_specifier_1
/home/heads/gcc/gcc-source/gcc/cp/parser.c:20642
0x638e04 cp_parser_class_specifier
/home/heads/gcc/gcc-source/gcc/cp/parser.c:20938
0x638e04 cp_parser_type_specifier
/home/heads/gcc/gcc-source/gcc/cp/parser.c:15298
0x6499fb cp_parser_decl_specifier_seq
/home/heads/gcc/gcc-source/gcc/cp/parser.c:12264
0x656ee8 cp_parser_single_declaration
/home/heads/gcc/gcc-source/gcc/cp/parser.c:25064
0x657212 cp_parser_template_declaration_after_parameters
/home/heads/gcc/gcc-source/gcc/cp/parser.c:24756
0x657a2e cp_parser_explicit_template_declaration
/home/heads/gcc/gcc-source/gcc/cp/parser.c:24991
0x657a2e cp_parser_template_declaration_after_export
/home/heads/gcc/gcc-source/gcc/cp/parser.c:25009
0x65c8e9 cp_parser_declaration
/home/heads/gcc/gcc-source/gcc/cp/parser.c:11631
0x65adca cp_parser_declaration_seq_opt
/home/heads/gcc/gcc-source/gcc/cp/parser.c:11553
0x65b0e5 cp_parser_translation_unit
/home/heads/gcc/gcc-source/gcc/cp/parser.c:4169
0x65b0e5 c_parse_file()
/home/heads/gcc/gcc-source/gcc/cp/parser.c:34539
0x71cee2 c_common_parse_file()
/home/heads/gcc/gcc-source/gcc/c-family/c-opts.c:1064
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.
