By default, the linker uses demangled symbol names in diagnostics. For example:
| undefined symbol | first referenced in file | ||
| ANewClass::getValue() | test.cpp.obj | 
The --no_demangle option instead shows the linkname for symbols in diagnostics. For example:
| undefined symbol | first referenced in file | ||
| _ZN9ANewClass8getValueEv | test.cpp.obj | 
For information on referencing symbol names, see Section 5.11. For information specifically about C++ symbol naming, see Section 14.