aidl_to_cpp_common.cpp

/*
 * Copyright (C) 2018, 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 "aidl_to_cpp_common.h"

#include <android-base/strings.h>
#include <unordered_map>

#include "ast_cpp.h"
#include "logging.h"
#include "os.h"

using ::android::base::Join;

namespace android {
namespace aidl {
namespace cpp {

string ClassName(const AidlDefinedType& defined_type, ClassNames type) {
  string base_name = defined_type.GetName();
  if (base_name.length() >= 2 && base_name[0] == 'I' && isupper(base_name[1])) {
    base_name = base_name.substr(1);
  }

  switch (type) {
    case ClassNames::CLIENT:
      return "Bp" + base_name;
    case ClassNames::SERVER:
      return "Bn" + base_name;
    case ClassNames::INTERFACE:
      return "I" + base_name;
    case ClassNames::DEFAULT_IMPL:
      return "I" + base_name + "Default";
    case ClassNames::BASE:
      return base_name;
    case ClassNames::RAW:
      [[fallthrough]];
    default:
      return defined_type.GetName();
  }
}

std::string HeaderFile(const AidlDefinedType& defined_type, ClassNames class_type,
                       bool use_os_sep) {
  std::string file_path = defined_type.GetPackage();
  for (char& c : file_path) {
    if (c == '.') {
      c = (use_os_sep) ? OS_PATH_SEPARATOR : '/';
    }
  }
  if (!file_path.empty()) {
    file_path += (use_os_sep) ? OS_PATH_SEPARATOR : '/';
  }
  file_path += ClassName(defined_type, class_type);
  file_path += ".h";

  return file_path;
}

void EnterNamespace(CodeWriter& out, const AidlDefinedType& defined_type) {
  const std::vector<std::string> packages = defined_type.GetSplitPackage();
  for (const std::string& package : packages) {
    out << "namespace " << package << " {\n";
  }
}
void LeaveNamespace(CodeWriter& out, const AidlDefinedType& defined_type) {
  const std::vector<std::string> packages = defined_type.GetSplitPackage();
  for (auto it = packages.rbegin(); it != packages.rend(); ++it) {
    out << "}  // namespace " << *it << "\n";
  }
}

string BuildVarName(const AidlArgument& a) {
  string prefix = "out_";
  if (a.GetDirection() & AidlArgument::IN_DIR) {
    prefix = "in_";
  }
  return prefix + a.GetName();
}

struct TypeInfo {
  // name of the type in C++ output
  std::string cpp_name;

  // function that writes an expression to convert a variable to a Json::Value
  // object
  std::function<void(CodeWriter& w, const string& var_name, bool isNdk)> toJsonValueExpr;
};

const static std::unordered_map<std::string, TypeInfo> kTypeInfoMap = {
    {"void", {"void", nullptr}},
    {"boolean",
     {
         "bool",
         [](CodeWriter& c, const string& var_name, bool) {
           c << "Json::Value(" << var_name << "? \"true\" : \"false\")";
         },
     }},
    {"byte",
     {
         "int8_t",
         [](CodeWriter& c, const string& var_name, bool) {
           c << "Json::Value(" << var_name << ")";
         },
     }},
    {"char",
     {
         "char16_t",
         [](CodeWriter& c, const string& var_name, bool isNdk) {
           if (isNdk) {
             c << "Json::Value(" << var_name << ")";
           } else {
             c << "Json::Value(std::string(android::String8(&" << var_name << ", 1)))";
           }
         },
     }},
    {"int",
     {
         "int32_t",
         [](CodeWriter& c, const string& var_name, bool) {
           c << "Json::Value(" << var_name << ")";
         },
     }},
    {"long",
     {
         "int64_t",
         [](CodeWriter& c, const string& var_name, bool) {
           c << "Json::Value(static_cast<Json::Int64>(" << var_name << "))";
         },
     }},
    {"float",
     {
         "float",
         [](CodeWriter& c, const string& var_name, bool) {
           c << "Json::Value(" << var_name << ")";
         },
     }},
    {"double",
     {
         "double",
         [](CodeWriter& c, const string& var_name, bool) {
           c << "Json::Value(" << var_name << ")";
         },
     }},
    {"String",
     {
         "std::string",
         [](CodeWriter& c, const string& var_name, bool) {
           c << "Json::Value(" << var_name << ")";
         },
     }}
    // missing List, Map, ParcelFileDescriptor, IBinder
};

TypeInfo GetTypeInfo(const AidlTypeSpecifier& aidl) {
  CHECK(aidl.IsResolved()) << aidl.ToString();
  const string& aidl_name = aidl.GetName();

  TypeInfo info;
  if (AidlTypenames::IsBuiltinTypename(aidl_name)) {
    auto it = kTypeInfoMap.find(aidl_name);
    if (it != kTypeInfoMap.end()) {
      info = it->second;
    }
  }
  // Missing interface and parcelable type
  return info;
}

inline bool CanWriteLog(const TypeInfo& t) {
  return t.cpp_name != "";
}

bool CanWriteLog(const AidlTypeSpecifier& aidl) {
  return CanWriteLog(GetTypeInfo(aidl));
}

void WriteLogFor(CodeWriter& writer, const AidlTypeSpecifier& type, const std::string& name,
                 bool isPointer, const std::string& log, bool isNdk) {
  const TypeInfo info = GetTypeInfo(type);
  if (!CanWriteLog(info)) {
    return;
  }

  const string var_object_expr = ((isPointer ? "*" : "")) + name;
  if (type.IsArray()) {
    writer << log << " = Json::Value(Json::arrayValue);\n";
    writer << "for (const auto& v: " << var_object_expr << ") " << log << ".append(";
    info.toJsonValueExpr(writer, "v", isNdk);
    writer << ");";
  } else {
    writer << log << " = ";
    info.toJsonValueExpr(writer, var_object_expr, isNdk);
    writer << ";";
  }
  writer << "\n";
}

void WriteLogForArguments(CodeWriterPtr& writer, const AidlArgument& a, bool isServer,
                          string logVarName, bool isNdk) {
  if (!CanWriteLog(a.GetType())) {
    return;
  }
  string logElementVarName = "_log_arg_element";
  (*writer) << "{\n";
  (*writer).Indent();
  (*writer) << "Json::Value " << logElementVarName << "(Json::objectValue);\n";
  string varName = isServer || isNdk ? BuildVarName(a) : a.GetName();
  (*writer) << logElementVarName << "[\"name\"] = \"" << varName << "\";\n";

  bool isPointer = a.IsOut() && !isServer;
  WriteLogFor(*(writer.get()), a.GetType(), varName, isPointer, logElementVarName + "[\"value\"]",
              isNdk);
  (*writer) << logVarName << ".append(" << logElementVarName << ");\n";
  (*writer) << "}\n";
  (*writer).Dedent();
}

const string GenLogBeforeExecute(const string className, const AidlMethod& method, bool isServer,
                                 bool isNdk) {
  string code;
  CodeWriterPtr writer = CodeWriter::ForString(&code);
  (*writer) << "Json::Value _log_input_args(Json::arrayValue);\n";

  (*writer) << "if (" << className << "::logFunc != nullptr) {\n";
  (*writer).Indent();

  for (const auto& a : method.GetArguments()) {
    if (a->IsIn()) {
      WriteLogForArguments(writer, *a, isServer, "_log_input_args", isNdk);
    }
  }

  (*writer).Dedent();
  (*writer) << "}\n";

  (*writer) << "auto _log_start = std::chrono::steady_clock::now();\n";
  writer->Close();
  return code;
}

const string GenLogAfterExecute(const string className, const AidlInterface& interface,
                                const AidlMethod& method, const string& statusVarName,
                                const string& returnVarName, bool isServer, bool isNdk) {
  string code;
  CodeWriterPtr writer = CodeWriter::ForString(&code);

  (*writer) << "if (" << className << "::logFunc != nullptr) {\n";
  (*writer).Indent();

  // Write the log as a Json object. For example,
  //
  // Json log object for following interface description
  //
  // package foo.bar;
  // interface IFoo {
  //   String TestMethod(int arg1, inout String[] arg2, out double arg3);
  // }
  //
  // would be:
  //
  // {
  //   duration_ms: 100.42,
  //   interface_name: "foo.bar.IFoo",
  //   method_name: "TestMethod",
  //   (proxy|stub)_address: "0x12345678",
  //   input_args: [
  //     {name: "arg1", value: 30,},
  //     {name: "arg2", value: ["apple", "grape"],},
  //   ],
  //   output_args: [
  //     {name: "arg2", value: ["mango", "banana"],},
  //     {name: "arg3", value: "10.5",},
  //   ],
  //   _aidl_return: "ok",
  //   binder_status: {
  //     exception_code: -8,
  //     exception_message: "Something wrong",
  //     transaction_error: 0,
  //     service_specific_error_code: -42,
  //   },
  // }
  (*writer) << "auto _log_end = std::chrono::steady_clock::now();\n";
  (*writer) << "Json::Value _log_transaction(Json::objectValue);\n";
  (*writer) << "_log_transaction[\"duration_ms\"] = "
            << "std::chrono::duration<double, std::milli>(_log_end - "
               "_log_start).count();\n";
  (*writer) << "_log_transaction[\"interface_name\"] = "
            << "Json::Value(\"" << interface.GetCanonicalName() << "\");\n";
  (*writer) << "_log_transaction[\"method_name\"] = "
            << "Json::Value(\"" << method.GetName() << "\");\n";

  (*writer) << "_log_transaction[\"" << (isServer ? "stub_address" : "proxy_address") << "\"] = ";
  (*writer) << "Json::Value("
            << "(std::ostringstream() << "
            << (isNdk && isServer ? "_aidl_impl" : "static_cast<const void*>(this)") << ").str()"
            << ");\n";
  (*writer) << "_log_transaction[\"input_args\"] = _log_input_args;\n";
  (*writer) << "Json::Value _log_output_args(Json::arrayValue);\n";

  (*writer) << "Json::Value _log_status(Json::objectValue);\n";
  if (isNdk) {
    (*writer) << "_log_status[\"exception_code\"] = Json::Value(AStatus_getExceptionCode("
              << statusVarName << ".get()));\n";
    (*writer) << "_log_status[\"exception_message\"] = Json::Value(AStatus_getMessage("
              << statusVarName << ".get()));\n";
    (*writer) << "_log_status[\"transaction_error\"] = Json::Value(AStatus_getStatus("
              << statusVarName << ".get()));\n";
    (*writer) << "_log_status[\"service_specific_error_code\"] = "
                 "Json::Value(AStatus_getServiceSpecificError("
              << statusVarName << ".get()));\n";
  } else {
    (*writer) << "_log_status[\"exception_code\"] = Json::Value(" << statusVarName
              << ".exceptionCode());\n";
    (*writer) << "_log_status[\"exception_message\"] = Json::Value(" << statusVarName
              << ".exceptionMessage());\n";
    (*writer) << "_log_status[\"transaction_error\"] = Json::Value(" << statusVarName
              << ".transactionError());\n";
    (*writer) << "_log_status[\"service_specific_error_code\"] = Json::Value(" << statusVarName
              << ".serviceSpecificErrorCode());\n";
  }

  (*writer) << "_log_transaction[\"binder_status\"] = _log_status;\n";

  for (const auto& a : method.GetOutArguments()) {
    WriteLogForArguments(writer, *a, isServer, "_log_output_args", isNdk);
  }

  (*writer) << "_log_transaction[\"output_args\"] = _log_output_args;\n";

  if (method.GetType().GetName() != "void") {
    WriteLogFor(*(writer.get()), method.GetType(), returnVarName, !isServer,
                "_log_transaction[\"" + returnVarName + "\"]", isNdk);
  }

  // call the user-provided function with the Json object for the entire
  // transaction
  (*writer) << className << "::logFunc(_log_transaction);\n";

  (*writer).Dedent();
  (*writer) << "}\n";

  writer->Close();
  return code;
}

std::string GenerateEnumValues(const AidlEnumDeclaration& enum_decl,
                               const std::vector<std::string>& enclosing_namespaces_of_enum_decl) {
  const auto fq_name =
      Join(Append(enclosing_namespaces_of_enum_decl, enum_decl.GetSplitPackage()), "::") +
      "::" + enum_decl.GetName();
  const auto size = enum_decl.GetEnumerators().size();
  std::ostringstream code;
  code << "#pragma clang diagnostic push\n";
  code << "#pragma clang diagnostic ignored \"-Wc++17-extensions\"\n";
  code << "template <>\n";
  code << "constexpr inline std::array<" << fq_name << ", " << size << "> enum_values<" << fq_name
       << "> = {\n";
  for (const auto& enumerator : enum_decl.GetEnumerators()) {
    code << "  " << fq_name << "::" << enumerator->GetName() << ",\n";
  }
  code << "};\n";
  code << "#pragma clang diagnostic pop\n";
  return code.str();
}

}  // namespace cpp
}  // namespace aidl
}  // namespace android