| /* |
| * 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" |
| |
| 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; |
| |
| /* 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() |
| ; node_a = node_a->next, node_b = node_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 (node_b->is_tail_sentinel()) |
| return PARAMETER_LIST_NO_MATCH; |
| |
| |
| const ir_variable *const param = (ir_variable *) node_a; |
| const ir_rvalue *const actual = (ir_rvalue *) node_b; |
| |
| 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: |
| 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 PARAMETER_LIST_NO_MATCH; |
| |
| case ir_var_const_in: |
| case ir_var_in: |
| if (!actual->type->can_implicitly_convert_to(param->type)) |
| return PARAMETER_LIST_NO_MATCH; |
| break; |
| |
| case ir_var_out: |
| if (!param->type->can_implicitly_convert_to(actual->type)) |
| return PARAMETER_LIST_NO_MATCH; |
| break; |
| |
| case ir_var_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. |
| */ |
| return PARAMETER_LIST_NO_MATCH; |
| |
| default: |
| assert(false); |
| return PARAMETER_LIST_NO_MATCH; |
| } |
| } |
| |
| /* 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 (!node_b->is_tail_sentinel()) |
| return PARAMETER_LIST_NO_MATCH; |
| |
| 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) |
| { |
| 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(); |
| |
| switch (parameter_lists_match(& sig->parameters, actual_parameters)) { |
| case PARAMETER_LIST_EXACT_MATCH: |
| *is_exact = true; |
| return sig; |
| 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; |
| } |
| |
| |
| static bool |
| parameter_lists_match_exact(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; |
| |
| for (/* empty */ |
| ; !node_a->is_tail_sentinel() && !node_b->is_tail_sentinel() |
| ; node_a = node_a->next, node_b = node_b->next) { |
| ir_variable *a = (ir_variable *) node_a; |
| ir_variable *b = (ir_variable *) node_b; |
| |
| /* If the types of the parameters do not match, the parameters lists |
| * are different. |
| */ |
| if (a->type != b->type) |
| return false; |
| } |
| |
| /* Unless both lists are exhausted, they differ in length and, by |
| * definition, do not match. |
| */ |
| return (node_a->is_tail_sentinel() == node_b->is_tail_sentinel()); |
| } |
| |
| ir_function_signature * |
| ir_function::exact_matching_signature(const exec_list *actual_parameters) |
| { |
| foreach_iter(exec_list_iterator, iter, signatures) { |
| ir_function_signature *const sig = |
| (ir_function_signature *) iter.get(); |
| |
| if (parameter_lists_match_exact(&sig->parameters, actual_parameters)) |
| return sig; |
| } |
| return NULL; |
| } |