signal SIGSEGV, Segmentation fault on return

[omerbrandis]

hello ,

I'm getting :
Program terminated with signal SIGSEGV, Segmentation fault.
#0 __GI___libc_free (mem=0x10172d1f1) at malloc.c:2951

this happes on method return statement .
method uses csv parser & decimal_for_cpp , i think its something about their interaction ...

this is the back trace from the generated core file:
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x00007fc57a18c512 in ?? ()
[Current thread is 1 (LWP 14230)]
(gdb) bt
#0 0x00007fc57a18c512 in ?? ()
#1 0x00007ffe00000000 in ?? ()
#2 0x000000000172d130 in ?? ()
#3 0x000000000172d120 in ?? ()
#4 0x00007ffea71201f8 in ?? ()
#5 0x0000000000000042 in ?? ()
#6 0x0000000000000042 in ?? ()
#7 0x00007ffea711ff80 in ?? ()
#8 0x000000010172d1f1 in ?? ()
#9 0x00007ffea7120750 in ?? ()
#10 0x00000000004211e8 in std::__detail::_Hashtable_alloc<std::allocator<std::__detail::_Hash_node<unsigned long, false> > >::_M_deallocate_buckets (this=0x10172d1f1, __bkts=0x7ffea711ff80, __n=66)
at /usr/include/c++/7/bits/hashtable_policy.h:2119
#11 0x000000000041c171 in std::_Vector_base<csv::internals::RawCSVField*, std::allocatorcsv::internals::RawCSVField* >::_Vector_impl::_Vector_impl (this=0x7ffea7120410)
at /usr/include/c++/7/bits/stl_vector.h:88
#12 0x000000000041797a in std::_Hashtable<std::__cxx11::basic_string<char, std::char_traits, std::allocator >, std::pair<std::__cxx11::basic_string<char, std::char_traits, std::allocator > const, unsigned long>, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits, std::allocator > const, unsigned long> >, std::__detail::_Select1st, std::equal_to<std::__cxx11::basic_string<char, std::char_traits, std::allocator > >, std::hash<std::__cxx11::basic_string<char, std::char_traits, std::allocator > >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true, false, true> >::_M_deallocate_buckets (this=0x7ffea7120030)
at /usr/include/c++/7/bits/hashtable.h:368
#13 0x000000000041765e in std::__cxx11::basic_string<char, std::char_traits, std::allocator >::_M_set_length (
this=0x41765e <std::__cxx11::basic_string<char, std::char_traits, std::allocator >::_M_set_length(unsigned long)+90>, __n=140731701395456) at /usr/include/c++/7/bits/basic_string.h:206
#14 0x0000000000412572 in std::__cxx11::basic_string<char, std::char_traits, std::allocator >::~basic_string (this=0x7ffea7120410, __in_chrg=)
at /usr/include/c++/7/bits/basic_string.h:647
#15 0x0000000000409fee in MainWindow::MainWindow (this=0x7ffea7120610, parent=0x0) at ../mainwindow.cpp:74
#16 0x00000000004092cf in main (argc=1, argv=0x7ffea7120758) at ../main.cpp:7

i've tried to debug it a little.
creating the csv::CSVReader object is not the cause.
reading the data is not the problem. (for (auto& row: MyCsvReader))

using strings is somehow causing the problem.
but have not yet found the logic to it :

code :
for (auto& row: MyCsvReader)
{
LongitudeAsString = row["Longitude"].getstd::string();
LatitudeString = row["Latitude"].getstd::string();
}

as is, works without the segfaut.

adding
Dec8Longitude = DEC_NAMESPACE::fromString<DEC_NAMESPACE::decimal<8>>(LongitudeAsString);

still works.

adding Dec8Latitude = DEC_NAMESPACE::fromString<DEC_NAMESPACE::decimal<8>>(LatitudeString);
leads to the crash.

tried
Dec8Latitude = DEC_NAMESPACE::fromString<DEC_NAMESPACE::decimal<8>>("2"); -> no crash.

tried
reusing same std::string twice
Dec8Longitude = DEC_NAMESPACE::fromString<DEC_NAMESPACE::decimal<8>>(LatitudeString)
Dec8Latitude = DEC_NAMESPACE::fromString<DEC_NAMESPACE::decimal<8>>(LatitudeString);
no crash. ( leads me to think its not the data in the file )

please advise,
Omer.

[omerbrandis]

( i've also opened an issue at dec for cpp ...vpiotr/decimal_for_cpp#49 )

[omerbrandis]

may have tracked it to something else ( in my code ) , but not closing this issue yet.

[omerbrandis]

my bad, corrupted the stack later in the code with the actual value...