Initial pass at resolving function calls
The code is still really rough and *REALLY* incomplete. This at least
passes the first few trivially simple test cases.
diff --git a/ir_function.cpp b/ir_function.cpp
new file mode 100644
index 0000000..a14b546
--- /dev/null
+++ b/ir_function.cpp
@@ -0,0 +1,185 @@
+/*
+ * Copyright © 2010 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include "glsl_types.h"
+#include "ir.h"
+
+int
+type_compare(const glsl_type *a, const glsl_type *b)
+{
+ switch (a->base_type) {
+ case GLSL_TYPE_UINT:
+ case GLSL_TYPE_INT:
+ case GLSL_TYPE_FLOAT:
+ case GLSL_TYPE_BOOL:
+ if ((a->vector_elements != b->vector_elements)
+ || (a->matrix_rows != b->matrix_rows))
+ return -1;
+
+ if (a->base_type == b->base_type)
+ return 0;
+
+ /* There is no implicit conversion to or from bool.
+ */
+ if ((a->base_type == GLSL_TYPE_BOOL)
+ || (b->base_type == GLSL_TYPE_BOOL))
+ return -1;
+
+ return 1;
+
+ case GLSL_TYPE_SAMPLER:
+ return ((a->sampler_dimensionality == b->sampler_dimensionality)
+ && (a->sampler_shadow == b->sampler_shadow)
+ && (a->sampler_array == b->sampler_array)
+ && (a->sampler_type == b->sampler_type))
+ ? 0 : -1;
+
+ case GLSL_TYPE_STRUCT:
+ return (strcmp(a->name, b->name) == 0) ? 0 : -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);
+}
+
+
+static int
+parameter_lists_match(exec_list *list_a, exec_list *list_b)
+{
+ exec_list_iterator iter_a = list_a->iterator();
+ exec_list_iterator iter_b = list_b->iterator();
+ int total_score = 0;
+
+ for (/* empty */ ; iter_a.has_next(); iter_a.next(), iter_b.next()) {
+ /* If all of the parameters from the other parameter list have been
+ * exhausted, the lists have different length and, by definition,
+ * do not match.
+ */
+ if (!iter_b.has_next())
+ return -1;
+
+
+ const ir_variable *const param = (ir_variable *) iter_a.get();
+ const ir_instruction *const actual = (ir_instruction *) iter_b.get();
+
+ /* 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)) {
+ case ir_var_auto:
+ case ir_var_uniform:
+ /* 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;
+
+ case ir_var_in:
+ score = type_compare(param->type, actual->type);
+ break;
+
+ case ir_var_out:
+ /* FINISHME: Make sure that actual is a valid lvalue. */
+ score = type_compare(actual->type, param->type);
+ break;
+
+ case ir_var_inout:
+ /* FINISHME: Make sure that actual is a valid lvalue. */
+
+ /* 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;
+ }
+
+ if (score < 0)
+ return -1;
+
+ total_score += score;
+ }
+
+ /* If all of the parameters from the other parameter list have been
+ * exhausted, the lists have different length and, by definition, do not
+ * match.
+ */
+ if (iter_b.has_next())
+ return -1;
+
+ return total_score;
+}
+
+
+const ir_function_signature *
+ir_function::matching_signature(exec_list *actual_parameters)
+{
+ ir_function_signature *match = NULL;
+
+ 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 (score == 0)
+ return sig;
+
+ if (score > 0) {
+ if (match != NULL)
+ return NULL;
+
+ match = sig;
+ }
+ }
+
+ return match;
+}