[Mesa-dev] [PATCH 5/5] glsl: Clarify ir_function::matching_sigature()

[Chris Bandy]

On 07/29/2011 08:59 PM, Chad Versace wrote:
> The function used a variable named 'score', which was an outright lie.
> A signature matches or it doesn't; there is no fuzzy scoring.
>
> Change the return type of parameter_lists_match() to an enum, and
> let ir_function::matching_sigature() switch on that enum.
>
> CC: Ian Romanick <ian.d.romanick at intel.com>
> CC: Kenneth Graunke <kenneth at whitecape.org>
> Signed-off-by: Chad Versace <chad at chad-versace.us>
> ---
>  src/glsl/ir_function.cpp |   53 ++++++++++++++++++++++++++++-----------------
>  1 files changed, 33 insertions(+), 20 deletions(-)
>
> diff --git a/src/glsl/ir_function.cpp b/src/glsl/ir_function.cpp
> index dd63e30..6cfc32c 100644
> --- a/src/glsl/ir_function.cpp
> +++ b/src/glsl/ir_function.cpp
> @@ -24,17 +24,28 @@
>  #include "glsl_types.h"
>  #include "ir.h"
>  
> +typedef enum {
> +   PARAMETER_LIST_NO_MATCH,
> +   PARAMETER_LIST_EXACT_MATCH,
> +   PARAMETER_LIST_INEXACT_MATCH, /*< Match requires implicit conversion. */
> +} parameter_list_match_t;
> +
>  /**
>   * \brief Check if two parameter lists match.
>   *
>   * \param list_a Parameters of the function definition.
>   * \param list_b Actual parameters passed to the function.
> - * \return If an exact match, return 0.
> - *         If an inexact match requiring implicit conversion, return 1.
> - *         If not a match, return -1.
>   * \see matching_signature()
>   */

Looks like the above comment block is now duplicated here.

> -static int
> +
> +/**
> + * \brief Check if two parameter lists match.
> + *
> + * \param list_a Parameters of the function definition.
> + * \param list_b Actual parameters passed to the function.
> + * \see matching_signature()
> + */
> +static parameter_list_match_t
>  parameter_lists_match(const exec_list *list_a, const exec_list *list_b)
>  {
>     const exec_node *node_a = list_a->head;
> @@ -52,7 +63,7 @@ parameter_lists_match(const exec_list *list_a, const exec_list *list_b)
>         * do not match.
>         */
>        if (node_b->is_tail_sentinel())
> -	 return -1;
> +	 return PARAMETER_LIST_NO_MATCH;
>  
>  
>        const ir_variable *const param = (ir_variable *) node_a;
> @@ -72,17 +83,17 @@ parameter_lists_match(const exec_list *list_a, const exec_list *list_b)
>  	  * as uniform.
>  	  */
>  	 assert(0);
> -	 return -1;
> +	 return PARAMETER_LIST_NO_MATCH;
>  
>        case ir_var_const_in:
>        case ir_var_in:
>  	 if (!actual->type->can_implicitly_convert_to(param->type))
> -	    return -1;
> +	    return PARAMETER_LIST_NO_MATCH;
>  	 break;
>  
>        case ir_var_out:
>  	 if (!param->type->can_implicitly_convert_to(actual->type))
> -	    return -1;
> +	    return PARAMETER_LIST_NO_MATCH;
>  	 break;
>  
>        case ir_var_inout:
> @@ -90,11 +101,11 @@ parameter_lists_match(const exec_list *list_a, const exec_list *list_b)
>  	  * there is int -> float but no float -> int), inout parameters must
>  	  * be exact matches.
>  	  */
> -	 return -1;
> +	 return PARAMETER_LIST_NO_MATCH;
>  
>        default:
>  	 assert(false);
> -	 return -1;
> +	 return PARAMETER_LIST_NO_MATCH;
>        }
>     }
>  
> @@ -103,12 +114,12 @@ parameter_lists_match(const exec_list *list_a, const exec_list *list_b)
>      * match.
>      */
>     if (!node_b->is_tail_sentinel())
> -      return -1;
> +      return PARAMETER_LIST_NO_MATCH;
>  
>     if (inexact_match)
> -      return 1;
> +      return PARAMETER_LIST_INEXACT_MATCH;
>     else
> -      return 0;
> +      return PARAMETER_LIST_EXACT_MATCH;
>  }
>  
>  
> @@ -132,18 +143,20 @@ ir_function::matching_signature(const exec_list *actual_parameters)
>        ir_function_signature *const sig =
>  	 (ir_function_signature *) iter.get();
>  
> -      const int score = parameter_lists_match(& sig->parameters,
> -					      actual_parameters);
> -
> -      /* If we found an exact match, simply return it */
> -      if (score == 0)
> +      switch (parameter_lists_match(& sig->parameters, actual_parameters)) {
> +      case PARAMETER_LIST_EXACT_MATCH:
>  	 return sig;
> -
> -      if (score > 0) {
> +      case PARAMETER_LIST_INEXACT_MATCH:
>  	 if (match == NULL)
>  	    match = sig;
>  	 else
>  	    multiple_inexact_matches = true;
> +	 continue;
> +      case PARAMETER_LIST_NO_MATCH:
> +	 continue;
> +      default:
> +	 assert(false);
> +	 return NULL;
>        }
>     }
>