GDB, the GNU Project debugger, allows you to see what is going on `inside' another program while it executes -- or what another program was doing at the moment it crashed.
GDB can do four main kinds of things (plus other things in support of these) to help you catch bugs in the act:
- Start your program, specifying anything that might affect its behavior.
- Make your program stop on specified conditions.
- Examine what has happened, when your program has stopped.
- Change things in your program, so you can experiment with correcting the effects of one bug and go on to learn about another.
module spider gdb to find out what environment modules are available for this application.
- HPC_GDB_DIR - installation directory
- HPC_GDB_BIN - executable directory
See https://sourceware.org/gdb/onlinedocs/gdb/Pretty-Printing.html#Pretty-Printing for information on pretty printers in GDB.
Pretty printers are provided by the compiler module (i.e. gcc/9.3.0), so you will need to load the GCC module and customize your ~/.gdbinit file:
Create or modify ".gdbinit" in your home directory so that it contains the following code to look for and load the compiler module's pretty-print driver:
python import os, sys gcc_python_dir = os.environ.get('HPC_GCC_PYTHON_DIR') if gcc_python_dir: sys.path.insert(0, gcc_python_dir) from libstdcxx.v6.printers import register_libstdcxx_printers register_libstdcxx_printers (None) end
NOTE: it is Python, so indentation matters...
Whenever you load the GDB module, load the appropriate GCC module along with it:
module load gdb/9.2 gcc/9.3.0
Now, when you start GDB, the libstdcxx pretty-printers will be available:
$ gdb -q
(gdb) info pretty-printer global pretty-printers: builtin mpx_bound128 libstdc++-v6 __gnu_cxx::_Slist_iterator __gnu_cxx::__8::_Slist_iterator ... ...