1 /*
2 * Copyright 2019 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "struct_parser_generator.h"
18
StructParserGenerator(const Declarations & decls)19 StructParserGenerator::StructParserGenerator(const Declarations& decls) {
20 is_little_endian = decls.is_little_endian;
21 for (const auto& s : decls.type_defs_queue_) {
22 if (s.second->GetDefinitionType() == TypeDef::Type::STRUCT) {
23 const auto* struct_def = dynamic_cast<const StructDef*>(s.second);
24 variable_struct_fields_.emplace_back(struct_def);
25 }
26 }
27 for (const auto& node : variable_struct_fields_) {
28 if (node.struct_def_->parent_ != nullptr) {
29 for (auto& parent : variable_struct_fields_) {
30 if (node.struct_def_->parent_->name_ == parent.struct_def_->name_) {
31 parent.children_.push_back(&node);
32 }
33 }
34 }
35 }
36 }
37
explore_children(const TreeNode & node,std::ostream & s) const38 void StructParserGenerator::explore_children(const TreeNode& node, std::ostream& s) const {
39 auto field = node.packet_field_;
40 if (!node.children_.empty()) {
41 s << "bool " << field->GetName() << "_child_found = false; /* Greedy match */";
42 }
43 for (const auto& child : node.children_) {
44 s << "if (!" << field->GetName() << "_child_found && ";
45 s << child->struct_def_->name_ << "::IsInstance(*" << field->GetName() << "_value.get())) {";
46 s << field->GetName() << "_child_found = true;";
47 s << "std::unique_ptr<" << child->struct_def_->name_ << "> " << child->packet_field_->GetName() << "_value;";
48 s << child->packet_field_->GetName() << "_value.reset(new ";
49 s << child->struct_def_->name_ << "(*" << field->GetName() << "_value));";
50 if (child->struct_def_->fields_.HasBody()) {
51 s << "auto optional_it = ";
52 s << child->struct_def_->name_ << "::Parse( " << child->packet_field_->GetName() << "_value.get(), ";
53 s << "to_bound, false);";
54 s << "if (optional_it) {";
55 s << "} else { return " << field->GetName() << "_value;}";
56 } else {
57 s << child->struct_def_->name_ << "::Parse( " << child->packet_field_->GetName() << "_value.get(), ";
58 s << "to_bound, false);";
59 }
60 explore_children(*child, s);
61 s << field->GetName() << "_value = std::move(" << child->packet_field_->GetName() << "_value);";
62
63 s << " }";
64 }
65 }
66
Generate(std::ostream & s) const67 void StructParserGenerator::Generate(std::ostream& s) const {
68 for (const auto& node : variable_struct_fields_) {
69 if (node.children_.empty()) {
70 continue;
71 }
72 auto field = node.packet_field_;
73 s << "inline std::unique_ptr<" << node.struct_def_->name_ << "> Parse" << node.struct_def_->name_;
74 if (is_little_endian) {
75 s << "(Iterator<kLittleEndian> to_bound) {";
76 } else {
77 s << "(Iterator<!kLittleEndian> to_bound) {";
78 }
79 s << field->GetDataType() << " " << field->GetName() << "_value = ";
80 s << "std::make_unique<" << node.struct_def_->name_ << ">();";
81
82 s << "auto " << field->GetName() << "_it = to_bound;";
83 s << "auto parent_optional_it = ";
84 s << node.struct_def_->name_ << "::Parse( " << field->GetName() << "_value.get(), ";
85 s << field->GetName() << "_it";
86 if (node.struct_def_->parent_ != nullptr) {
87 s << ", true);";
88 } else {
89 s << ");";
90 }
91 s << "if (parent_optional_it) {";
92 s << field->GetName() << "_it = *parent_optional_it;";
93 s << "} else { return nullptr; }";
94
95 explore_children(node, s);
96 s << "return " << field->GetName() << "_value; }";
97 }
98 }
99