Question

My C++ program exits with a std::logic_error and I’d like to track down the source line that caused it. How can I do that?

TBH, I’m using gdb, using g++ -g in order to add debug info. All I can get are these messages:

This application has requested the Runtime to terminate it in an unusual way.
Please contact the application’s support team for more information.
terminate called after throwing an instance of ‘std::logic_error’
what(): basic_string::_S_construct null not valid

Catchpoint 1 (exception thrown), 0x0045ffa0 in __cxa_throw ()
(gdb) bt
#0  0x0045ffa0 in __cxa_throw ()
#1  0x004601e8 in std::__throw_logic_error(char const*) ()
#2  0x00502238 in typeinfo for std::__timepunct<wchar_t> ()
#3  0x004685f8 in std::runtime_error::what() const ()
#4  0x03210da8 in ?? ()
#5  0x002efbcc in ?? ()
#6  0x00468734 in std::domain_error::~domain_error() ()
#7  0x00000000 in ?? ()
(gdb)

Answer 1

The exception objects don’t carry any source information with them. However, they hopefully contain a useful message accessible using the what() member. Other than that you’d either have to use a debugger allowing to break when exceptions are thrown or set a break point into the constructor of std::logic_error. As long as exceptions are exceptional this works OK. It doesn’t work too well with code throwing exceptions in non-exceptional cases.