#include "glsl_types.h"
#include "ir.h"
+#include "glsl_parser_extras.h"
+#include "main/errors.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_FUNCTION:
- 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);
-}
+typedef enum {
+ PARAMETER_LIST_NO_MATCH,
+ PARAMETER_LIST_EXACT_MATCH,
+ PARAMETER_LIST_INEXACT_MATCH /*< Match requires implicit conversion. */
+} parameter_list_match_t;
-
-static int
-parameter_lists_match(const exec_list *list_a, const exec_list *list_b)
+/**
+ * \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(_mesa_glsl_parse_state *state,
+ 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;
- switch ((enum ir_variable_mode)(param->mode)) {
+ 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->data.mode)) {
case ir_var_auto:
case ir_var_uniform:
+ case ir_var_shader_storage:
case ir_var_temporary:
/* These are all error conditions. It is invalid for a parameter to
* a function to be declared as auto (not in, out, or inout) or
* as uniform.
*/
assert(0);
- return -1;
+ return PARAMETER_LIST_NO_MATCH;
- case ir_var_in:
- score = type_compare(param->type, actual->type);
+ case ir_var_const_in:
+ case ir_var_function_in:
+ if (!actual->type->can_implicitly_convert_to(param->type, state))
+ return PARAMETER_LIST_NO_MATCH;
break;
- case ir_var_out:
- score = type_compare(actual->type, param->type);
+ case ir_var_function_out:
+ if (!param->type->can_implicitly_convert_to(actual->type, state))
+ return PARAMETER_LIST_NO_MATCH;
break;
- case ir_var_inout:
+ case ir_var_function_inout:
/* Since there are no bi-directional automatic conversions (e.g.,
* 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)
+/* Classes of parameter match, sorted (mostly) best matches first.
+ * See is_better_parameter_match() below for the exceptions.
+ * */
+typedef enum {
+ PARAMETER_EXACT_MATCH,
+ PARAMETER_FLOAT_TO_DOUBLE,
+ PARAMETER_INT_TO_FLOAT,
+ PARAMETER_INT_TO_DOUBLE,
+ PARAMETER_OTHER_CONVERSION,
+} parameter_match_t;
+
+
+static parameter_match_t
+get_parameter_match_type(const ir_variable *param,
+ const ir_rvalue *actual)
{
- ir_function_signature *match = NULL;
+ const glsl_type *from_type;
+ const glsl_type *to_type;
+
+ if (param->data.mode == ir_var_function_out) {
+ from_type = param->type;
+ to_type = actual->type;
+ } else {
+ from_type = actual->type;
+ to_type = param->type;
+ }
- foreach_iter(exec_list_iterator, iter, signatures) {
- ir_function_signature *const sig =
- (ir_function_signature *) iter.get();
+ if (from_type == to_type)
+ return PARAMETER_EXACT_MATCH;
- const int score = parameter_lists_match(& sig->parameters,
- actual_parameters);
+ if (to_type->base_type == GLSL_TYPE_DOUBLE) {
+ if (from_type->base_type == GLSL_TYPE_FLOAT)
+ return PARAMETER_FLOAT_TO_DOUBLE;
+ return PARAMETER_INT_TO_DOUBLE;
+ }
- if (score == 0)
- return sig;
+ if (to_type->base_type == GLSL_TYPE_FLOAT)
+ return PARAMETER_INT_TO_FLOAT;
+
+ /* int -> uint and any other oddball conversions */
+ return PARAMETER_OTHER_CONVERSION;
+}
- if (score > 0) {
- if (match != NULL)
- return NULL;
- match = sig;
+static bool
+is_better_parameter_match(parameter_match_t a_match,
+ parameter_match_t b_match)
+{
+ /* From section 6.1 of the GLSL 4.00 spec (and the ARB_gpu_shader5 spec):
+ *
+ * 1. An exact match is better than a match involving any implicit
+ * conversion.
+ *
+ * 2. A match involving an implicit conversion from float to double
+ * is better than match involving any other implicit conversion.
+ *
+ * [XXX: Not in GLSL 4.0: Only in ARB_gpu_shader5:
+ * 3. A match involving an implicit conversion from either int or uint
+ * to float is better than a match involving an implicit conversion
+ * from either int or uint to double.]
+ *
+ * If none of the rules above apply to a particular pair of conversions,
+ * neither conversion is considered better than the other.
+ *
+ * --
+ *
+ * Notably, the int->uint conversion is *not* considered to be better
+ * or worse than int/uint->float or int/uint->double.
+ */
+
+ if (a_match >= PARAMETER_INT_TO_FLOAT && b_match == PARAMETER_OTHER_CONVERSION)
+ return false;
+
+ return a_match < b_match;
+}
+
+
+static bool
+is_best_inexact_overload(const exec_list *actual_parameters,
+ ir_function_signature **matches,
+ int num_matches,
+ ir_function_signature *sig)
+{
+ /* From section 6.1 of the GLSL 4.00 spec (and the ARB_gpu_shader5 spec):
+ *
+ * "A function definition A is considered a better
+ * match than function definition B if:
+ *
+ * * for at least one function argument, the conversion for that argument
+ * in A is better than the corresponding conversion in B; and
+ *
+ * * there is no function argument for which the conversion in B is better
+ * than the corresponding conversion in A.
+ *
+ * If a single function definition is considered a better match than every
+ * other matching function definition, it will be used. Otherwise, a
+ * semantic error occurs and the shader will fail to compile."
+ */
+ for (ir_function_signature **other = matches;
+ other < matches + num_matches; other++) {
+ if (*other == sig)
+ continue;
+
+ const exec_node *node_a = sig->parameters.head;
+ const exec_node *node_b = (*other)->parameters.head;
+ const exec_node *node_p = actual_parameters->head;
+
+ bool better_for_some_parameter = false;
+
+ for (/* empty */
+ ; !node_a->is_tail_sentinel()
+ ; node_a = node_a->next,
+ node_b = node_b->next,
+ node_p = node_p->next) {
+ parameter_match_t a_match = get_parameter_match_type(
+ (const ir_variable *)node_a,
+ (const ir_rvalue *)node_p);
+ parameter_match_t b_match = get_parameter_match_type(
+ (const ir_variable *)node_b,
+ (const ir_rvalue *)node_p);
+
+ if (is_better_parameter_match(a_match, b_match))
+ better_for_some_parameter = true;
+
+ if (is_better_parameter_match(b_match, a_match))
+ return false; /* B is better for this parameter */
+ }
+
+ if (!better_for_some_parameter)
+ return false; /* A must be better than B for some parameter */
+
+ }
+
+ return true;
+}
+
+
+static ir_function_signature *
+choose_best_inexact_overload(_mesa_glsl_parse_state *state,
+ const exec_list *actual_parameters,
+ ir_function_signature **matches,
+ int num_matches)
+{
+ if (num_matches == 0)
+ return NULL;
+
+ if (num_matches == 1)
+ return *matches;
+
+ /* Without GLSL 4.0 / ARB_gpu_shader5, there is no overload resolution
+ * among multiple inexact matches. Note that state may be NULL here if
+ * called from the linker; in that case we assume everything supported in
+ * any GLSL version is available. */
+ if (!state || state->is_version(400, 0) || state->ARB_gpu_shader5_enable) {
+ for (ir_function_signature **sig = matches; sig < matches + num_matches; sig++) {
+ if (is_best_inexact_overload(actual_parameters, matches, num_matches, *sig))
+ return *sig;
}
}
+ return NULL; /* no best candidate */
+}
+
+
+ir_function_signature *
+ir_function::matching_signature(_mesa_glsl_parse_state *state,
+ const exec_list *actual_parameters,
+ bool allow_builtins)
+{
+ bool is_exact;
+ return matching_signature(state, actual_parameters, allow_builtins,
+ &is_exact);
+}
+
+ir_function_signature *
+ir_function::matching_signature(_mesa_glsl_parse_state *state,
+ const exec_list *actual_parameters,
+ bool allow_builtins,
+ bool *is_exact)
+{
+ ir_function_signature **inexact_matches = NULL;
+ ir_function_signature **inexact_matches_temp;
+ ir_function_signature *match = NULL;
+ int num_inexact_matches = 0;
+
+ /* 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_in_list(ir_function_signature, sig, &this->signatures) {
+ /* Skip over any built-ins that aren't available in this shader. */
+ if (sig->is_builtin() && (!allow_builtins ||
+ !sig->is_builtin_available(state)))
+ continue;
+
+ switch (parameter_lists_match(state, & sig->parameters, actual_parameters)) {
+ case PARAMETER_LIST_EXACT_MATCH:
+ *is_exact = true;
+ free(inexact_matches);
+ return sig;
+ case PARAMETER_LIST_INEXACT_MATCH:
+ inexact_matches_temp = (ir_function_signature **)
+ realloc(inexact_matches,
+ sizeof(*inexact_matches) *
+ (num_inexact_matches + 1));
+ if (inexact_matches_temp == NULL) {
+ _mesa_error_no_memory(__func__);
+ free(inexact_matches);
+ return NULL;
+ }
+ inexact_matches = inexact_matches_temp;
+ inexact_matches[num_inexact_matches++] = sig;
+ 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;
+
+ match = choose_best_inexact_overload(state, actual_parameters,
+ inexact_matches, num_inexact_matches);
+
+ free(inexact_matches);
return match;
}
}
ir_function_signature *
-ir_function::exact_matching_signature(const exec_list *actual_parameters)
+ir_function::exact_matching_signature(_mesa_glsl_parse_state *state,
+ const exec_list *actual_parameters)
{
- foreach_iter(exec_list_iterator, iter, signatures) {
- ir_function_signature *const sig =
- (ir_function_signature *) iter.get();
+ foreach_in_list(ir_function_signature, sig, &this->signatures) {
+ /* Skip over any built-ins that aren't available in this shader. */
+ if (sig->is_builtin() && !sig->is_builtin_available(state))
+ continue;
if (parameter_lists_match_exact(&sig->parameters, actual_parameters))
return sig;