#include "glsl_types.h"
#include "ir.h"
-int
-type_compare(const glsl_type *a, const glsl_type *b)
-{
- /* If the types are the same, they trivially match.
- */
- if (a == b)
- return 0;
-
- switch (a->base_type) {
- case GLSL_TYPE_UINT:
- case GLSL_TYPE_INT:
- case GLSL_TYPE_BOOL:
- /* There is no implicit conversion to or from integer types or bool.
- */
- if ((a->is_integer() != b->is_integer())
- || (a->is_boolean() != b->is_boolean()))
- return -1;
-
- /* FALLTHROUGH */
-
- case GLSL_TYPE_FLOAT:
- if ((a->vector_elements != b->vector_elements)
- || (a->matrix_columns != b->matrix_columns))
- return -1;
-
- return 1;
-
- case GLSL_TYPE_SAMPLER:
- case GLSL_TYPE_STRUCT:
- /* Samplers and structures must match exactly.
- */
- return -1;
-
- case GLSL_TYPE_ARRAY:
- if ((b->base_type != GLSL_TYPE_ARRAY)
- || (a->length != b->length))
- return -1;
-
- /* From GLSL 1.50 spec, page 27 (page 33 of the PDF):
- * "There are no implicit array or structure conversions."
- *
- * If the comparison of the array element types detects that a conversion
- * would be required, the array types do not match.
- */
- return (type_compare(a->fields.array, b->fields.array) == 0) ? 0 : -1;
-
- case GLSL_TYPE_VOID:
- case GLSL_TYPE_ERROR:
- default:
- /* These are all error conditions. It is invalid for a parameter to
- * a function to be declared as error, void, or a function.
- */
- return -1;
- }
-
- /* This point should be unreachable.
- */
- assert(0);
-}
-
-
-static int
+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.
+ * \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;
const exec_node *node_b = list_b->head;
- int total_score = 0;
+
+ /* This is set to true if there is an inexact match requiring an implicit
+ * conversion. */
+ bool inexact_match = false;
for (/* empty */
; !node_a->is_tail_sentinel()
* 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;
- const ir_instruction *const actual = (ir_instruction *) node_b;
+ const ir_rvalue *const actual = (ir_rvalue *) node_b;
- /* Determine whether or not the types match. If the types are an
- * exact match, the match score is zero. If the types don't match
- * but the actual parameter can be coerced to the type of the declared
- * parameter, the match score is one.
- */
- int score;
+ if (param->type == actual->type)
+ continue;
+
+ /* Try to find an implicit conversion from actual to param. */
+ inexact_match = true;
switch ((enum ir_variable_mode)(param->mode)) {
case ir_var_auto:
case ir_var_uniform:
* as uniform.
*/
assert(0);
- return -1;
+ return PARAMETER_LIST_NO_MATCH;
case ir_var_const_in:
case ir_var_in:
- score = type_compare(param->type, actual->type);
+ if (!actual->type->can_implicitly_convert_to(param->type))
+ return PARAMETER_LIST_NO_MATCH;
break;
case ir_var_out:
- score = type_compare(actual->type, param->type);
+ if (!param->type->can_implicitly_convert_to(actual->type))
+ return PARAMETER_LIST_NO_MATCH;
break;
case ir_var_inout:
* there is int -> float but no float -> int), inout parameters must
* be exact matches.
*/
- score = (type_compare(actual->type, param->type) == 0) ? 0 : -1;
- break;
+ return PARAMETER_LIST_NO_MATCH;
default:
assert(false);
+ return PARAMETER_LIST_NO_MATCH;
}
-
- if (score < 0)
- return -1;
-
- total_score += score;
}
/* If all of the parameters from the other parameter list have been
* match.
*/
if (!node_b->is_tail_sentinel())
- return -1;
+ return PARAMETER_LIST_NO_MATCH;
- return total_score;
+ if (inexact_match)
+ return PARAMETER_LIST_INEXACT_MATCH;
+ else
+ return PARAMETER_LIST_EXACT_MATCH;
}
ir_function_signature *
ir_function::matching_signature(const exec_list *actual_parameters)
{
- ir_function_signature *match = NULL;
- int matched_score = 0;
+ bool is_exact;
+ return matching_signature(actual_parameters, &is_exact);
+}
+ir_function_signature *
+ir_function::matching_signature(const exec_list *actual_parameters,
+ bool *is_exact)
+{
+ ir_function_signature *match = NULL;
+ bool multiple_inexact_matches = false;
+
+ /* From page 42 (page 49 of the PDF) of the GLSL 1.20 spec:
+ *
+ * "If an exact match is found, the other signatures are ignored, and
+ * the exact match is used. Otherwise, if no exact match is found, then
+ * the implicit conversions in Section 4.1.10 "Implicit Conversions" will
+ * be applied to the calling arguments if this can make their types match
+ * a signature. In this case, it is a semantic error if there are
+ * multiple ways to apply these conversions to the actual arguments of a
+ * call such that the call can be made to match multiple signatures."
+ */
foreach_iter(exec_list_iterator, iter, signatures) {
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:
+ *is_exact = true;
return sig;
-
- /* If we found a match with fewer conversions, use that instead */
- if (score > 0 && (match == NULL || score < matched_score)) {
- match = sig;
- matched_score = score;
+ 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;
}
}
+ /* There is no exact match (we would have returned it by now). If there
+ * are multiple inexact matches, the call is ambiguous, which is an error.
+ *
+ * FINISHME: Report a decent error. Returning NULL will likely result in
+ * FINISHME: a "no matching signature" error; it should report that the
+ * FINISHME: call is ambiguous. But reporting errors from here is hard.
+ */
+ *is_exact = false;
+
+ if (multiple_inexact_matches)
+ return NULL;
+
return match;
}