http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50207
Bug #: 50207
Summary: G++ segv's on reduced test case
Classification: Unclassified
Product: gcc
Version: 4.7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: berg...@gcc.gnu.org
A G++ from today's trunk (20110826) segv's on a reduced test case (using delta)
like so:
bergner@igoo:~> cat minimal.ii
typedef long unsigned int size_t;
namespace std __attribute__ ((__visibility__ ("default")))
{
using::size_t;
}
typedef unsigned char uint8_t;
namespace std
{
namespace decimal
{
template < class _Fmt > struct _FmtTraits;
class decimal32;
}
}
namespace std
{
namespace decimal
{
template <> class _FmtTraits < decimal32 >
{
public:
static const std::size_t _NumBytes = 4UL;
};
template < class _Tr > class _DecBase
{
uint8_t _Bytes[_Tr::_NumBytes];
};
class decimal32:public _DecBase < _FmtTraits < decimal32 > >
{
decimal32 () { }
};
}
}
bergner@igoo:~> /home/bergner/gcc/install/gcc-mainline-debug/bin/g++ -Wall -S
minimal.ii
g++: internal compiler error: Segmentation fault (program cc1plus)
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.
GDB show this backtrace:
#0 0x0000000010412cc8 in decl_is_template_id (decl=0xfffb6edcc18,
template_info=0xfffb6edcc18)
at /home/bergner/gcc/gcc-mainline-base/gcc/cp/mangle.c:267
#1 0x000000001041b44c in write_nested_name (decl=0xfffb6e24ac0) at
/home/bergner/gcc/gcc-mainline-base/gcc/cp/mangle.c:928
#2 0x000000001041ab48 in write_name (decl=0xfffb6e24ac0, ignore_local_scope=0)
at /home/bergner/gcc/gcc-mainline-base/gcc/cp/mangle.c:855
#3 0x00000000104284e4 in write_class_enum_type (type=0xfffb6edd4a0) at
/home/bergner/gcc/gcc-mainline-base/gcc/cp/mangle.c:2398
#4 0x0000000010424840 in write_type (type=0xfffb6edd4a0) at
/home/bergner/gcc/gcc-mainline-base/gcc/cp/mangle.c:1884
#5 0x000000001042d1ec in write_template_arg (node=0xfffb6edcc18) at
/home/bergner/gcc/gcc-mainline-base/gcc/cp/mangle.c:2843
#6 0x0000000010428868 in write_template_args (args=0xfffb6f13a70) at
/home/bergner/gcc/gcc-mainline-base/gcc/cp/mangle.c:2427
#7 0x000000001041b50c in write_nested_name (decl=0xfffb6e245b8) at
/home/bergner/gcc/gcc-mainline-base/gcc/cp/mangle.c:932
#8 0x000000001041ab48 in write_name (decl=0xfffb6e245b8, ignore_local_scope=0)
at /home/bergner/gcc/gcc-mainline-base/gcc/cp/mangle.c:855
#9 0x00000000104284e4 in write_class_enum_type (type=0xfffb6edccc0) at
/home/bergner/gcc/gcc-mainline-base/gcc/cp/mangle.c:2398
#10 0x0000000010424840 in write_type (type=0xfffb6edccc0) at
/home/bergner/gcc/gcc-mainline-base/gcc/cp/mangle.c:1884
#11 0x000000001042d1ec in write_template_arg (node=0xfffb6edccc0) at
/home/bergner/gcc/gcc-mainline-base/gcc/cp/mangle.c:2843
#12 0x0000000010428868 in write_template_args (args=0xfffb6f14088) at
/home/bergner/gcc/gcc-mainline-base/gcc/cp/mangle.c:2427
#13 0x000000001041b50c in write_nested_name (decl=0xfffb6e24ac0) at
/home/bergner/gcc/gcc-mainline-base/gcc/cp/mangle.c:932
#14 0x000000001041ab48 in write_name (decl=0xfffb6e24ac0, ignore_local_scope=0)
at /home/bergner/gcc/gcc-mainline-base/gcc/cp/mangle.c:855
#15 0x00000000104284e4 in write_class_enum_type (type=0xfffb6edd4a0) at
/home/bergner/gcc/gcc-mainline-base/gcc/cp/mangle.c:2398
#16 0x0000000010424840 in write_type (type=0xfffb6edd4a0) at
/home/bergner/gcc/gcc-mainline-base/gcc/cp/mangle.c:1884
#17 0x000000001042d1ec in write_template_arg (node=0xfffb6edcc18) at
/home/bergner/gcc/gcc-mainline-base/gcc/cp/mangle.c:2843
#18 0x0000000010428868 in write_template_args (args=0xfffb6f13a70) at
/home/bergner/gcc/gcc-mainline-base/gcc/cp/mangle.c:2427
...
The backtrace also show we have 10's of thousands of frames stacked repeated
over and over, so it looks like we've gone into some type of infinite
recursion. A quick look at GCC 4.6 show's it fails in the same manner. I
haven't checked anything earlier.
