| /* |
| * Copyright (C) 2019, The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include "parser.h" |
| #include "aidl_language_y.h" |
| #include "logging.h" |
| |
| void yylex_init(void**); |
| void yylex_destroy(void*); |
| void yyset_in(FILE* f, void*); |
| int yyparse(Parser*); |
| YY_BUFFER_STATE yy_scan_buffer(char*, size_t, void*); |
| void yy_delete_buffer(YY_BUFFER_STATE, void*); |
| |
| const AidlDocument* Parser::Parse(const std::string& filename, |
| const android::aidl::IoDelegate& io_delegate, |
| AidlTypenames& typenames, bool is_preprocessed) { |
| auto clean_path = android::aidl::IoDelegate::CleanPath(filename); |
| // reuse pre-parsed document from typenames |
| for (auto& doc : typenames.AllDocuments()) { |
| if (doc->GetLocation().GetFile() == clean_path) { |
| return doc.get(); |
| } |
| } |
| // Make sure we can read the file first, before trashing previous state. |
| unique_ptr<string> raw_buffer = io_delegate.GetFileContents(clean_path); |
| if (raw_buffer == nullptr) { |
| AIDL_ERROR(clean_path) << "Error while opening file for parsing"; |
| return nullptr; |
| } |
| |
| // We're going to scan this buffer in place, and yacc demands we put two |
| // nulls at the end. |
| raw_buffer->append(2u, '\0'); |
| |
| Parser parser(clean_path, *raw_buffer, is_preprocessed); |
| |
| if (yy::parser(&parser).parse() != 0 || parser.HasError()) { |
| return nullptr; |
| } |
| |
| // transfer ownership to AidlTypenames and return the raw pointer |
| const AidlDocument* result = parser.document_.get(); |
| if (!typenames.AddDocument(std::move(parser.document_))) { |
| return nullptr; |
| } |
| return result; |
| } |
| |
| void Parser::SetTypeParameters(AidlTypeSpecifier* type, |
| std::vector<std::unique_ptr<AidlTypeSpecifier>>* type_args) { |
| if (type->IsArray()) { |
| AIDL_ERROR(type) << "Must specify type parameters (<>) before array ([])."; |
| AddError(); |
| } |
| if (!type->SetTypeParameters(type_args)) { |
| AIDL_ERROR(type) << "Can only specify one set of type parameters."; |
| AddError(); |
| delete type_args; |
| } |
| } |
| |
| void Parser::CheckValidTypeName(const AidlToken& token, const AidlLocation& loc) { |
| if (!is_preprocessed_ && token.GetText().find('.') != std::string::npos) { |
| AIDL_ERROR(loc) << "Type name can't be qualified. Use `package`."; |
| AddError(); |
| } |
| } |
| |
| void Parser::SetPackage(const AidlPackage& package) { |
| if (is_preprocessed_) { |
| AIDL_ERROR(package) << "Preprocessed file can't declare package."; |
| AddError(); |
| } |
| package_ = package.GetName(); |
| } |
| |
| const AidlDefinedType* AsDefinedType(const AidlNode& node) { |
| struct Visitor : AidlVisitor { |
| const AidlDefinedType* defined_type = nullptr; |
| void Visit(const AidlInterface& t) override { defined_type = &t; } |
| void Visit(const AidlEnumDeclaration& t) override { defined_type = &t; } |
| void Visit(const AidlStructuredParcelable& t) override { defined_type = &t; } |
| void Visit(const AidlUnionDecl& t) override { defined_type = &t; } |
| void Visit(const AidlParcelable& t) override { defined_type = &t; } |
| } v; |
| node.DispatchVisit(v); |
| return v.defined_type; |
| } |
| |
| bool CheckNoRecursiveDefinition(const AidlNode& node) { |
| struct Visitor : AidlVisitor { |
| enum { |
| NOT_STARTED = 0, |
| STARTED = 1, |
| FINISHED = 2, |
| }; |
| std::map<const AidlParcelable*, int> visited; |
| std::vector<std::string> path; |
| bool found_cycle = false; |
| |
| void Visit(const AidlStructuredParcelable& t) override { FindCycle(&t); } |
| void Visit(const AidlUnionDecl& t) override { FindCycle(&t); } |
| void Visit(const AidlParcelable& t) override { FindCycle(&t); } |
| |
| bool FindCycle(const AidlParcelable* p) { |
| // no need to search further |
| if (found_cycle) { |
| return true; |
| } |
| // we just found a cycle |
| if (visited[p] == STARTED) { |
| path.push_back(p->GetName()); |
| AIDL_ERROR(p) << p->GetName() |
| << " is a recursive parcelable: " << android::base::Join(path, "->"); |
| return (found_cycle = true); |
| } |
| // we arrived here with a different route. |
| if (visited[p] == FINISHED) { |
| return false; |
| } |
| // start DFS |
| visited[p] = STARTED; |
| path.push_back(p->GetName()); |
| for (const auto& f : p->GetFields()) { |
| const auto& ref = f->GetType(); |
| if (!ref.IsArray() && !ref.IsHeapNullable()) { |
| const auto& type = ref.GetDefinedType(); |
| if (type && type->AsParcelable()) { |
| if (FindCycle(type->AsParcelable())) { |
| return true; |
| } |
| } |
| } |
| } |
| path.pop_back(); |
| visited[p] = FINISHED; |
| return false; |
| } |
| } v; |
| VisitTopDown(v, node); |
| return !v.found_cycle; |
| } |
| |
| class ReferenceResolver : public AidlVisitor { |
| public: |
| ReferenceResolver(TypeResolver& resolver, bool* success) |
| : resolver_(resolver), success_(success) {} |
| |
| void Visit(const AidlTypeSpecifier& t) override { |
| // We're visiting the same node again. This can happen when two constant references |
| // point to an ancestor of this node. |
| if (t.IsResolved()) { |
| return; |
| } |
| AIDL_FATAL_IF(scope_.empty(), t) << "Can't have an unresolved type in global scope"; |
| |
| AidlTypeSpecifier& type = const_cast<AidlTypeSpecifier&>(t); |
| if (!resolver_(scope_.back(), &type)) { |
| AIDL_ERROR(type) << "Failed to resolve '" << type.GetUnresolvedName() << "'"; |
| *success_ = false; |
| } |
| |
| // require definition: |
| // - parcelable, union |
| // - T |
| // - @nullable(heap=false) T |
| // interfaces, enums, arrays, @nullable(heap=true), we don't need a full definition |
| if (scope_.back()->AsParcelable()) { |
| auto resolved = t.GetDefinedType(); |
| if (resolved && resolved->AsParcelable()) { |
| if (!t.IsArray() && !t.IsHeapNullable()) { |
| VisitAll(*resolved); |
| } |
| } |
| } |
| } |
| |
| void Visit(const AidlConstantReference& v) override { |
| if (IsCircularReference(&v)) { |
| *success_ = false; |
| return; |
| } |
| |
| if (v.GetRefType()) { |
| VisitAll(*v.GetRefType()); |
| } |
| |
| const AidlConstantValue* resolved = v.Resolve(scope_.back()); |
| if (!resolved) { |
| AIDL_ERROR(v) << "Unknown reference '" << v.Literal() << "'"; |
| *success_ = false; |
| return; |
| } |
| |
| // On error, skip recursive visiting to avoid redundant messages |
| if (!*success_) { |
| return; |
| } |
| // resolve recursive references |
| PushConstRef(&v); |
| VisitAll(*resolved); |
| PopConstRef(); |
| } |
| |
| void VisitAll(const AidlNode& node) { |
| std::function<void(const AidlNode&)> top_down = [&](const AidlNode& a) { |
| a.DispatchVisit(*this); |
| auto defined_type = AsDefinedType(a); |
| if (defined_type) PushScope(defined_type); |
| a.TraverseChildren(top_down); |
| if (defined_type) PopScope(); |
| }; |
| top_down(node); |
| } |
| |
| private: |
| void PushConstRef(const AidlConstantReference* ref) { |
| stack_.push_back(ref); |
| if (ref->GetRefType()) { |
| PushScope(ref->GetRefType()->GetDefinedType()); |
| } |
| } |
| |
| void PopConstRef() { |
| if (stack_.back()->GetRefType()) { |
| PopScope(); |
| } |
| stack_.pop_back(); |
| } |
| |
| void PushScope(const AidlDefinedType* scope) { scope_.push_back(scope); } |
| |
| void PopScope() { scope_.pop_back(); } |
| |
| bool IsCircularReference(const AidlConstantReference* ref) { |
| auto it = |
| std::find_if(stack_.begin(), stack_.end(), [&](const auto& elem) { return elem == ref; }); |
| if (it == stack_.end()) { |
| return false; |
| } |
| std::vector<std::string> path; |
| while (it != stack_.end()) { |
| path.push_back((*it)->Literal()); |
| ++it; |
| } |
| path.push_back(ref->Literal()); |
| AIDL_ERROR(ref) << "Found a circular reference: " << android::base::Join(path, " -> "); |
| return true; |
| } |
| |
| TypeResolver& resolver_; |
| bool* success_; |
| std::vector<const AidlConstantReference*> stack_ = {}; |
| std::vector<const AidlDefinedType*> scope_ = {}; |
| }; |
| |
| // Resolve "unresolved" types in the "main" document. |
| bool ResolveReferences(const AidlDocument& document, TypeResolver& type_resolver) { |
| bool success = true; |
| |
| ReferenceResolver ref_resolver(type_resolver, &success); |
| ref_resolver.VisitAll(document); |
| |
| success &= CheckNoRecursiveDefinition(document); |
| |
| return success; |
| } |
| |
| Parser::Parser(const std::string& filename, std::string& raw_buffer, bool is_preprocessed) |
| : filename_(filename), is_preprocessed_(is_preprocessed) { |
| yylex_init(&scanner_); |
| buffer_ = yy_scan_buffer(&raw_buffer[0], raw_buffer.length(), scanner_); |
| } |
| |
| Parser::~Parser() { |
| yy_delete_buffer(buffer_, scanner_); |
| yylex_destroy(scanner_); |
| } |
| |
| void Parser::MakeDocument(const AidlLocation& location, const Comments& comments, |
| std::vector<std::unique_ptr<AidlImport>> imports, |
| std::vector<std::unique_ptr<AidlDefinedType>> defined_types) { |
| AIDL_FATAL_IF(document_.get(), location); |
| document_ = std::make_unique<AidlDocument>(location, comments, std::move(imports), |
| std::move(defined_types), is_preprocessed_); |
| } |