The value of strings doesn't appear in eclipse mars CDT

Question

Why does the value of strings in Eclipse Mars CDT not appear in the expression or variables windows? It appears {...} but i want to see the value itself under the value tab.

How can i do this?

Answer 1

What is going on here is CDT is showing the information that GDB is providing to it.

For a trivial program, with the debugger stopped on the line with return 0;

#include <string>
using namespace std;

int main() {
    string mystring = "my string here";
    return 0;
}

this is what I see in the CDT variable view:

which matches what I see in GDB:

(gdb) p mystring 
$1 = {static npos = <optimised out>, 
  _M_dataplus = {<std::allocator<char>> = {<__gnu_cxx::new_allocator<char>> = {<No data fields>}, <No data fields>}, 
    _M_p = 0x602028 "my string here"}}

Pretty Printing C++

However, what I suspect you want is the pretty printers for libstdc++ which makes the variables view look like this:

Create a ~/.gdbinit file with the following contents (updating the path for your machine)

python
import sys
sys.path.insert(0, '/usr/share/gcc-4.8/python/')
from libstdcxx.v6.printers import register_libstdcxx_printers
register_libstdcxx_printers (None)
end

Then point your launch configuration at that gdbinit file and start debugging.

• GDB wiki entry on the subject: https://sourceware.org/gdb/wiki/STLSupport
• GCC manual entry: https://gcc.gnu.org/onlinedocs/libstdc++/manual/debug.html