Re: Top Dowm Variable Communication

[Ramón García]

You have to put the register_name as an attribute of Register_decl_control

%union {
  struct register_decl_contd_data {
      const char* register_name;
      /* other data that you want for register_decl_contd */
   } register_decl_contd_data;
   // Other union members for other terminals and non terminals
}

/* Associate the symbol register_decl_contd with that union member */

%type <register_decl_contd_data> Register_decl_contd


%%

/* In the grammar  read and write into the member */

Register_decl: REGISTER IDENTIFIER { $3.register_name = $2;  }
Register_decl_contd

Register_decl_contd { work with $0.register_name }

Do yourself a favour, and buy the Dragon book (Aho, Seti, Ullman,
"Compilers. Principles Techniques and Tools") Chapter 5 "Syntax
directed translation" has all the details.. I think that Synopsys, a
company that charges about 10000 $ for each software license, can
afford a 30 $ book.

On 8/22/07, Arijit Das <address@hidden> wrote:
> Even though Bison is a bottom up parser, if I need to pass a variable's
> content top-down, what are the possible ways (except using global
> variable)?
>
>
> Register_decl
>         : REGISTER IDENTIFIER Register_decl_contd
>                 {
>                         Char * register_name = $2;
>                         // $2 has the 'register_name' now. I wanted that
> name to be communicated down to the scope of the non-terminal
> 'Register_decl_contd'
>                 }
>         ;
>
>
> Register_decl_contd
>         : '.' IDENTIFIER ...something...
>                 { ... }
>         | '=' IDENTIFIER ...something...
>                 { ... }
>         | '[' IDENTIFIER ...something...
>                 {
>                         // I want to use get the content of
> 'register_name' here to be able to print user friendly error messages,
> if required.
>                         // How can I get that info since register_name
> is defined in a top level scope in the non-terminal hierarchy? Any help?
>                 }
>
>         ;
>
>
> Thanks
> Arijit
>
>
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