Re: [gimplefe] Patch for recognizing function declarations

[Diego Novillo <dnovillo at google dot com>]

On Tue, Jul 31, 2012 at 11:06 AM, Sandeep Soni <soni.sandeepb@gmail.com> wrote:

> +/* The syntax of a function declaration is as follows:
> +
> +   FUNCTION_DECL<Name, Type, Parms>
> +   <
> +      function body
> +   >
> +
> +   Here, each of the PARMS in itself is a parameter declaration similar to a
> +   variable declaration, TYPE is the type of the variable that this
> +   function returns and FUNCTION BODY is the series of statements that define
> +   the beahavior of the function.
> +
> +   Following are some of the examples for which the syntax of the function
> +   declarations are described.
> +
> +   1. C-like function as
> +      void foo (int first, float second)
> +        {
> +          first = second;
> +        }
> +
> +   The corresponding gimple syntax is:
> +     FUNCTION_DECL <foo, VOID_TYPE,
> +                    PARM_DECL<first, INTEGER_TYPE<4>>,
> +                    PARM_DECL<second, REAL_TYPE<4>>>
> +     <
> +       GIMPLE_ASSIGN <PARM_DECL,first, second, NULL>
> +     >
> +
> +   2. C-like function as
> +      int foo (int first, float second)
> +       {
> +          int local_first;
> +          float local_second;
> +
> +          local_first = first;
> +          local_second = second;
> +
> +          return local_first;
> +       }
> +
> +   The corresponding gimple syntax is:
> +     FUNCTION_DECL <foo, INTEGER_TYPE<4>,
> +                    PARM_DECL<first, INTEGER_TYPE<4>>,
> +                    PARM_DECL<second, REAL_TYPE<4>>>
> +     <
> +        VAR_DECL <local_first, INTEGER_TYPE<4>>
> +       VAR_DECL <local_second, REAL_TYPE<4>>
> +       VAR_DECL <return_var, INTEGER_TYPE<4>>
> +
> +       gimple_assign <parm_decl, local_first, first, NULL>
> +       gimple_assign <parm_decl, local_second, second, NULL>
> +       gimple_assign <parm_decl, return_var, first, NULL>
> +       gimple_return <return_var>
> +     >
> +
> +   Note: 1) The syntax closely mimics the -fdump-tree-gimple-raw option.
> +        2) The function declaration tuple needs to be checked against the
> +           call of the function for order and the number of arguments.
> +        3) A symbol table entry for the function should be made. The
> +           variables defined within the function should be made to have
> +           function scope.  */

Nice.  Thanks for this documentation.

> +  next_token = gl_consume_token (parser->lexer);
> +  while (!gl_at_eof(parser->lexer))

Space before '('.

> +    {
> +      if (next_token->type == CPP_COMMA)
> +       {
> +         next_token = gl_consume_token (parser->lexer);
> +         if (gl_tree_code_for_token (next_token) == PARM_DECL)
> +            gp_parse_parm_decl (parser);
> +         else
> +           error_at (next_token->location,
> +                     "Unsupported declaration of parameters");
> +      else if (next_token->type == CPP_GREATER)
> +       break;
> +    }

Could you factor this into its own function? You will likely need to
parse other comma-separated lists.

Also, please add some test cases with the patch.


Diego.