Re: [PATCH] DW_AT_calling_convention support REV 2

[Petr Sorfa <petrs@caldera.com>]

Hi Daniel,

> > Revised patch for supporting DW_AT_calling_convention. This helps GDB
> > identify the "main" program for languages that do not have a starting
> > subroutine called "main". It adds a new API set for keeping track of the
> > symbol associated with "main". Note that there are 3 checks for
> > DW_AT_calling_convention. They are all necessary as they are detected at
> > different times when processing program debug information.
> 
> I wasn't quite clear... there's one thing that should be different.
> 
> > + /* Determine whether the symbol passed is equivalent to
> > +    the ``main'' symbol. Returns 0 if not or if there is no ``main''
> > +    symbol set. */
> > + int
> > + is_main_symbol (struct symbol *check_symbol)
> > + {
> > +   return (check_symbol == NULL ? 0 : symbol_of_main == check_symbol);
> > + }
> >
> >   void
> >   _initialize_symtab (void)
> 
> I was thinking like:
> 
> int
> is_main_symbol (struct symbol *check_symbol)
> {
>   if (symbol_of_main && symbol_of_main == check_symbol)
>     return 1;
>   else if (strcmp (SYMBOL_NAME (check_symbol), get_main_name ()) == 0)
>     return 1;
>   return 0;
> }
Good, I agree, that makes it more generic. Need to check for
check_symbol for NULL as this might tank GDB at the second if.

> And then change all callers of get_main_name () to use this.
> 
> (Note that this requires being careful if symbol_of_main gets
> unloaded and we load a C program afterwards!)
> 
> Make sense?  Sound reasonable?
Um, you've lost me. There is no get_main_name() function, do you mean
get_main_symbol() or main_name()? I still not sure what the callers of
the function should do.

Although, I do agree that the patch should catch unloading the
main_symbol, but how?

Petr

> 
> --
> Daniel Jacobowitz                           Carnegie Mellon University
> MontaVista Software                         Debian GNU/Linux Developer