Inheritance of gfc_symbol / gfc_component

[Tobias Burnus]

On 08/16/2012 02:59 PM, Tobias Schlüter wrote:
> A place where C++ inheritance is a trivial improvement is the 
> red-black tree used for storing various objects (gfc_symtree, 
> gfc_gsymbol, gfc_st_label, I think).  This is currently implemented 
> with macro-based inheritance.  It is trivial to replace the macro with 
> C++ inheritance, but if one touches this code, it might make more 
> sense to do a real job instead and to convert the symbol-keeping code 
> to the compiler's hash-table implementation, which as a benefit should 
> make the compiler faster by get rid of lots of string comparisons. 

Well, most string comparisons in gfortran are of the type ..->name ==  
...->name, which is fast. The reason is that those are obtained via 
gfc_get_string, which in turn calls:
   ident = get_identifier (temp_name);
   return IDENTIFIER_POINTER (ident);

Thus, same name == same pointer. (I think in some cases we do call 
strcmp even when a normal comparison would do.)

(I haven't carefully looked at the patch and thus cannot comment on it.)

Tobias