clang++ warns

[c.]

Hi,

Compiling a recent version of the default branch with clang++ I see many many 
repetitions of the warnings below.
It is just warnings, I don't know whether this is expected or it is something 
to worry about, but I thought it might be worth reporting.

CC-ing jwe as this seems related to his new rework of the interpreter.

c.



In file included from ../octave/libinterp/corefcn/call-stack.h:38:
../octave/libinterp/corefcn/stack-frame.h:923:18: warning: 
'octave::user_fcn_stack_frame::varval' hides overloaded virtual function 
[-Woverloaded-virtual]
    octave_value varval (const symbol_record& sym) const;
                 ^
../octave/libinterp/corefcn/stack-frame.h:831:18: note: hidden overloaded 
virtual function 'octave::base_value_stack_frame::varval' declared here: type 
mismatch at 1st
      parameter ('size_t' (aka 'unsigned long') vs 'const octave::symbol_record 
&')
    octave_value varval (size_t data_offset) const
                 ^
../octave/libinterp/corefcn/stack-frame.h:925:19: warning: 
'octave::user_fcn_stack_frame::varref' hides overloaded virtual function 
[-Woverloaded-virtual]
    octave_value& varref (const symbol_record& sym);
                  ^
../octave/libinterp/corefcn/stack-frame.h:836:19: note: hidden overloaded 
virtual function 'octave::base_value_stack_frame::varref' declared here: type 
mismatch at 1st
      parameter ('size_t' (aka 'unsigned long') vs 'const octave::symbol_record 
&')
    octave_value& varref (size_t data_offset)
                  ^
../octave/libinterp/corefcn/stack-frame.h:983:18: warning: 
'octave::scope_stack_frame::varval' hides overloaded virtual function 
[-Woverloaded-virtual]
    octave_value varval (const symbol_record& sym) const;
                 ^
../octave/libinterp/corefcn/stack-frame.h:831:18: note: hidden overloaded 
virtual function 'octave::base_value_stack_frame::varval' declared here: type 
mismatch at 1st
      parameter ('size_t' (aka 'unsigned long') vs 'const octave::symbol_record 
&')
    octave_value varval (size_t data_offset) const
                 ^
../octave/libinterp/corefcn/stack-frame.h:985:19: warning: 
'octave::scope_stack_frame::varref' hides overloaded virtual function 
[-Woverloaded-virtual]
    octave_value& varref (const symbol_record& sym);
                  ^
../octave/libinterp/corefcn/stack-frame.h:836:19: note: hidden overloaded 
virtual function 'octave::base_value_stack_frame::varref' declared here: type 
mismatch at 1st
      parameter ('size_t' (aka 'unsigned long') vs 'const octave::symbol_record 
&')
    octave_value& varref (size_t data_offset)
                  ^