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generate_cpp.cpp
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generate_cpp.cpp
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/**
* Copyright (C) 2015, 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 "generate_cpp.h"
#include "aidl.h"
#include <algorithm>
#include <cctype>
#include <cstring>
#include <memory>
#include <random>
#include <set>
#include <string>
#include <android-base/format.h>
#include <android-base/stringprintf.h>
#include <android-base/strings.h>
#include "aidl_language.h"
#include "aidl_to_cpp.h"
#include "logging.h"
#include "os.h"
using android::base::Join;
using android::base::StringPrintf;
using std::set;
using std::string;
using std::unique_ptr;
using std::vector;
namespace android {
namespace aidl {
namespace cpp {
namespace internals {
namespace {
const char kAndroidStatusVarName[] = "_aidl_ret_status";
const char kCodeVarName[] = "_aidl_code";
const char kFlagsVarName[] = "_aidl_flags";
const char kDataVarName[] = "_aidl_data";
const char kErrorLabel[] = "_aidl_error";
const char kImplVarName[] = "_aidl_impl";
const char kDelegateImplVarName[] = "_aidl_delegate";
const char kParcelVarName[] = "_aidl_parcel";
const char kReplyVarName[] = "_aidl_reply";
const char kReturnVarName[] = "_aidl_return";
const char kStatusVarName[] = "_aidl_status";
const char kTraceVarName[] = "_aidl_trace";
const char kAndroidParcelLiteral[] = "::android::Parcel";
const char kAndroidStatusLiteral[] = "::android::status_t";
const char kAndroidStatusOk[] = "::android::OK";
const char kAndroidStatusBadValue[] = "::android::BAD_VALUE";
const char kBinderStatusLiteral[] = "::android::binder::Status";
const char kIBinderHeader[] = "binder/IBinder.h";
const char kIInterfaceHeader[] = "binder/IInterface.h";
const char kBinderDelegateHeader[] = "binder/Delegate.h";
const char kParcelHeader[] = "binder/Parcel.h";
const char kStabilityHeader[] = "binder/Stability.h";
const char kStatusHeader[] = "binder/Status.h";
const char kString16Header[] = "utils/String16.h";
const char kTraceHeader[] = "binder/Trace.h";
const char kStrongPointerHeader[] = "utils/StrongPointer.h";
const char kAndroidBaseMacrosHeader[] = "android-base/macros.h";
void GenerateBreakOnStatusNotOk(CodeWriter& out) {
out.Write("if (((%s) != (%s))) {\n", kAndroidStatusVarName, kAndroidStatusOk);
out.Write(" break;\n");
out.Write("}\n");
}
void GenerateGotoErrorOnBadStatus(CodeWriter& out) {
out.Write("if (((%s) != (%s))) {\n", kAndroidStatusVarName, kAndroidStatusOk);
out.Write(" goto %s;\n", kErrorLabel);
out.Write("}\n");
}
// Format three types of arg list for method.
// for_declaration & !type_name_only: int a // for method decl with type and arg
// for_declaration & type_name_only: int /*a*/ // for method decl with type
// !for_declaration : a // for method call with arg (with direction)
string GenerateArgList(const AidlTypenames& typenames, const AidlMethod& method,
bool for_declaration, bool type_name_only) {
vector<string> method_arguments;
for (const unique_ptr<AidlArgument>& a : method.GetArguments()) {
string literal;
// b/144943748: CppNameOf FileDescriptor is unique_fd. Don't pass it by
// const reference but by value to make it easier for the user to keep
// it beyond the scope of the call. unique_fd is a thin wrapper for an
// int (fd) so passing by value is not expensive.
const bool non_copyable = IsNonCopyableType(a->GetType(), typenames);
if (for_declaration) {
// Method declarations need typenames, pointers to out params, and variable
// names that match the .aidl specification.
literal = CppNameOf(a->GetType(), typenames);
if (a->IsOut()) {
literal = literal + "*";
} else {
const auto defined_type = typenames.TryGetDefinedType(a->GetType().GetName());
const bool is_enum = defined_type && defined_type->AsEnumDeclaration() != nullptr;
const bool is_primitive = AidlTypenames::IsPrimitiveTypename(a->GetType().GetName());
// We pass in parameters that are not primitives by const reference.
// Arrays of primitives are not primitives.
if (!(is_primitive || is_enum || non_copyable) || a->GetType().IsArray()) {
literal = "const " + literal + "&";
}
}
if (type_name_only) {
literal += " /*" + a->GetName() + "*/";
} else {
literal += " " + a->GetName();
}
} else {
std::string var_name = BuildVarName(*a);
if (a->IsOut()) {
literal = "&" + var_name;
} else if (non_copyable) {
literal = "std::move(" + var_name + ")";
} else {
literal = var_name;
}
}
method_arguments.push_back(literal);
}
if (method.GetType().GetName() != "void") {
string literal;
if (for_declaration) {
literal = CppNameOf(method.GetType(), typenames) + "*";
if (type_name_only) {
literal += " /*" + string(kReturnVarName) + "*/";
} else {
literal += " " + string(kReturnVarName);
}
} else {
literal = string{"&"} + kReturnVarName;
}
method_arguments.push_back(literal);
}
return Join(method_arguments, ", ");
}
void GenerateMethodDecl(CodeWriter& out, const AidlTypenames& types, const AidlMethod& method,
const string& clazz) {
string clazz_prefix = clazz.empty() ? "" : clazz + "::";
out << "::android::binder::Status " << clazz_prefix << method.GetName() << "("
<< GenerateArgList(types, method, /*for_declartion=*/true, /*type_name_only=*/false) << ")";
}
void GenerateClientTransaction(CodeWriter& out, const AidlTypenames& typenames,
const AidlInterface& interface, const AidlMethod& method,
const Options& options) {
const string i_name = ClassName(interface, ClassNames::INTERFACE);
const string bp_name = GetQualifiedName(interface, ClassNames::CLIENT);
const string bn_name = GetQualifiedName(interface, ClassNames::SERVER);
GenerateMethodDecl(out, typenames, method, bp_name);
out << " {\n";
out.Indent();
// Declare parcels to hold our query and the response.
out.Write("%s %s;\n", kAndroidParcelLiteral, kDataVarName);
if (interface.IsSensitiveData()) {
out.Write("%s.markSensitive();\n", kDataVarName);
}
out.Write("%s.markForBinder(remoteStrong());\n", kDataVarName);
// Even if we're oneway, the transact method still takes a parcel.
out.Write("%s %s;\n", kAndroidParcelLiteral, kReplyVarName);
// Declare the status_t variable we need for error handling.
out.Write("%s %s = %s;\n", kAndroidStatusLiteral, kAndroidStatusVarName, kAndroidStatusOk);
// We unconditionally return a Status object.
out.Write("%s %s;\n", kBinderStatusLiteral, kStatusVarName);
if (options.GenTraces()) {
out.Write(
"::android::binder::ScopedTrace %s(ATRACE_TAG_AIDL, \"AIDL::cpp::%s::%s::cppClient\");\n",
kTraceVarName, interface.GetName().c_str(), method.GetName().c_str());
}
if (options.GenLog()) {
out << GenLogBeforeExecute(bp_name, method, false /* isServer */, false /* isNdk */);
}
// Add the name of the interface we're hoping to call.
out.Write("%s = %s.writeInterfaceToken(getInterfaceDescriptor());\n", kAndroidStatusVarName,
kDataVarName);
GenerateGotoErrorOnBadStatus(out);
for (const auto& a : method.GetArguments()) {
const string var_name = ((a->IsOut()) ? "*" : "") + a->GetName();
if (a->IsIn()) {
// Serialization looks roughly like:
// _aidl_ret_status = _aidl_data.WriteInt32(in_param_name);
// if (_aidl_ret_status != ::android::OK) { goto error; }
out.Write("%s = %s.%s(%s);\n", kAndroidStatusVarName, kDataVarName,
ParcelWriteMethodOf(a->GetType(), typenames).c_str(),
ParcelWriteCastOf(a->GetType(), typenames, var_name).c_str());
GenerateGotoErrorOnBadStatus(out);
} else if (a->IsOut() && a->GetType().IsDynamicArray()) {
// Special case, the length of the out array is written into the parcel.
// _aidl_ret_status = _aidl_data.writeVectorSize(&out_param_name);
// if (_aidl_ret_status != ::android::OK) { goto error; }
out.Write("%s = %s.writeVectorSize(%s);\n", kAndroidStatusVarName, kDataVarName,
var_name.c_str());
GenerateGotoErrorOnBadStatus(out);
}
}
// Invoke the transaction on the remote binder and confirm status.
std::vector<std::string> flags;
if (method.IsOneway()) flags.push_back("::android::IBinder::FLAG_ONEWAY");
if (interface.IsSensitiveData()) flags.push_back("::android::IBinder::FLAG_CLEAR_BUF");
out.Write("%s = remote()->transact(%s, %s, &%s, %s);\n", kAndroidStatusVarName,
GetTransactionIdFor(bn_name, method).c_str(), kDataVarName, kReplyVarName,
flags.empty() ? "0" : Join(flags, " | ").c_str());
// If the method is not implemented in the remote side, try to call the
// default implementation, if provided.
vector<string> arg_names;
for (const auto& a : method.GetArguments()) {
if (IsNonCopyableType(a->GetType(), typenames)) {
arg_names.emplace_back(StringPrintf("std::move(%s)", a->GetName().c_str()));
} else {
arg_names.emplace_back(a->GetName());
}
}
if (method.GetType().GetName() != "void") {
arg_names.emplace_back(kReturnVarName);
}
out.Write("if (UNLIKELY(%s == ::android::UNKNOWN_TRANSACTION && %s::getDefaultImpl())) {\n",
kAndroidStatusVarName, i_name.c_str());
out.Write(" return %s::getDefaultImpl()->%s(%s);\n", i_name.c_str(), method.GetName().c_str(),
Join(arg_names, ", ").c_str());
out.Write("}\n");
GenerateGotoErrorOnBadStatus(out);
if (!method.IsOneway()) {
// Strip off the exception header and fail if we see a remote exception.
// _aidl_ret_status = _aidl_status.readFromParcel(_aidl_reply);
// if (_aidl_ret_status != ::android::OK) { goto error; }
// if (!_aidl_status.isOk()) { return _aidl_ret_status; }
out.Write("%s = %s.readFromParcel(%s);\n", kAndroidStatusVarName, kStatusVarName,
kReplyVarName);
GenerateGotoErrorOnBadStatus(out);
out.Write("if (!%s.isOk()) {\n", kStatusVarName);
out.Write(" return %s;\n", kStatusVarName);
out.Write("}\n");
}
// Type checking should guarantee that nothing below emits code until "return
// status" if we are a oneway method, so no more fear of accessing reply.
// If the method is expected to return something, read it first by convention.
if (method.GetType().GetName() != "void") {
out.Write("%s = %s.%s(%s);\n", kAndroidStatusVarName, kReplyVarName,
ParcelReadMethodOf(method.GetType(), typenames).c_str(),
ParcelReadCastOf(method.GetType(), typenames, kReturnVarName).c_str());
GenerateGotoErrorOnBadStatus(out);
}
for (const AidlArgument* a : method.GetOutArguments()) {
// Deserialization looks roughly like:
// _aidl_ret_status = _aidl_reply.ReadInt32(out_param_name);
// if (_aidl_status != ::android::OK) { goto _aidl_error; }
out.Write("%s = %s.%s(%s);\n", kAndroidStatusVarName, kReplyVarName,
ParcelReadMethodOf(a->GetType(), typenames).c_str(),
ParcelReadCastOf(a->GetType(), typenames, a->GetName()).c_str());
GenerateGotoErrorOnBadStatus(out);
}
// If we've gotten to here, one of two things is true:
// 1) We've read some bad status_t
// 2) We've only read status_t == OK and there was no exception in the
// response.
// In both cases, we're free to set Status from the status_t and return.
out.Write("%s:\n", kErrorLabel);
out.Write("%s.setFromStatusT(%s);\n", kStatusVarName, kAndroidStatusVarName);
if (options.GenLog()) {
out << GenLogAfterExecute(bp_name, interface, method, kStatusVarName, kReturnVarName,
false /* isServer */, false /* isNdk */);
}
out.Write("return %s;\n", kStatusVarName);
out.Dedent();
out << "}\n";
}
void GenerateClientMetaTransaction(CodeWriter& out, const AidlInterface& interface,
const AidlMethod& method, const Options& options) {
AIDL_FATAL_IF(method.IsUserDefined(), method);
const string bp_name = GetQualifiedName(interface, ClassNames::CLIENT);
const string bn_name = GetQualifiedName(interface, ClassNames::SERVER);
if (method.GetName() == kGetInterfaceVersion && options.Version() > 0) {
// Note: race condition can happen here, but no locking is required
// because 1) writing an interger is atomic and 2) this transaction
// will always return the same value, i.e., competing threads will
// give write the same value to cached_version_.
out << "int32_t " << bp_name << "::" << kGetInterfaceVersion << "() {\n"
<< " if (cached_version_ == -1) {\n"
<< " ::android::Parcel data;\n"
<< " ::android::Parcel reply;\n"
<< " data.writeInterfaceToken(getInterfaceDescriptor());\n"
<< " ::android::status_t err = remote()->transact("
<< GetTransactionIdFor(bn_name, method) << ", data, &reply);\n"
<< " if (err == ::android::OK) {\n"
<< " ::android::binder::Status _aidl_status;\n"
<< " err = _aidl_status.readFromParcel(reply);\n"
<< " if (err == ::android::OK && _aidl_status.isOk()) {\n"
<< " cached_version_ = reply.readInt32();\n"
<< " }\n"
<< " }\n"
<< " }\n"
<< " return cached_version_;\n"
<< "}\n";
out << "\n";
}
if (method.GetName() == kGetInterfaceHash && !options.Hash().empty()) {
out << "std::string " << bp_name << "::" << kGetInterfaceHash << "() {\n"
<< " std::lock_guard<std::mutex> lockGuard(cached_hash_mutex_);\n"
<< " if (cached_hash_ == \"-1\") {\n"
<< " ::android::Parcel data;\n"
<< " ::android::Parcel reply;\n"
<< " data.writeInterfaceToken(getInterfaceDescriptor());\n"
<< " ::android::status_t err = remote()->transact("
<< GetTransactionIdFor(bn_name, method) << ", data, &reply);\n"
<< " if (err == ::android::OK) {\n"
<< " ::android::binder::Status _aidl_status;\n"
<< " err = _aidl_status.readFromParcel(reply);\n"
<< " if (err == ::android::OK && _aidl_status.isOk()) {\n"
<< " reply.readUtf8FromUtf16(&cached_hash_);\n"
<< " }\n"
<< " }\n"
<< " }\n"
<< " return cached_hash_;\n"
<< "}\n";
}
}
} // namespace
void GenerateClientSource(CodeWriter& out, const AidlInterface& interface,
const AidlTypenames& typenames, const Options& options) {
vector<string> include_list = {
HeaderFile(interface, ClassNames::CLIENT, false),
HeaderFile(interface, ClassNames::SERVER, false), // for TRANSACTION_* consts
kParcelHeader, kAndroidBaseMacrosHeader};
if (options.GenLog()) {
include_list.emplace_back("chrono");
include_list.emplace_back("functional");
}
for (const auto& path : include_list) {
out << "#include <" << path << ">\n";
}
out << "\n";
const string i_name = ClassName(interface, ClassNames::INTERFACE);
const string bp_name = ClassName(interface, ClassNames::CLIENT);
const string q_name = GetQualifiedName(interface, ClassNames::CLIENT);
EnterNamespace(out, interface);
out << "\n";
// The constructor just passes the IBinder instance up to the super
// class.
out << q_name << "::" << bp_name << "(const ::android::sp<::android::IBinder>& _aidl_impl)\n";
out << " : BpInterface<" + i_name + ">(_aidl_impl){\n";
out << "}\n";
out << "\n";
if (options.GenLog()) {
out << "std::function<void(const " + q_name + "::TransactionLog&)> " << q_name
<< "::logFunc;\n";
out << "\n";
}
// Clients define a method per transaction.
for (const auto& method : interface.GetMethods()) {
if (method->IsUserDefined()) {
GenerateClientTransaction(out, typenames, interface, *method, options);
} else {
GenerateClientMetaTransaction(out, interface, *method, options);
}
out << "\n";
}
LeaveNamespace(out, interface);
}
namespace {
void GenerateConstantDefinitions(CodeWriter& out, const AidlDefinedType& type,
const AidlTypenames& typenames, const string& template_decl,
const string& q_name) {
for (const auto& constant : type.GetConstantDeclarations()) {
const AidlConstantValue& value = constant->GetValue();
if (value.GetType() != AidlConstantValue::Type::STRING) continue;
std::string cpp_type = CppNameOf(constant->GetType(), typenames);
out << template_decl;
out << "const " << cpp_type << "& " << q_name << "::" << constant->GetName() << "() {\n";
out << " static const " << cpp_type << " value("
<< constant->ValueString(ConstantValueDecorator) << ");\n";
out << " return value;\n";
out << "}\n";
}
}
void GenerateConstantDeclarations(CodeWriter& out, const AidlDefinedType& type,
const AidlTypenames& typenames) {
for (const auto& constant : type.GetConstantDeclarations()) {
const AidlTypeSpecifier& type = constant->GetType();
const auto cpp_type = CppNameOf(type, typenames);
if (type.Signature() == "String") {
out << "static const " << cpp_type << "& " << constant->GetName() << "()";
GenerateDeprecated(out, *constant);
out << ";\n";
} else if (type.Signature() == "float" || type.Signature() == "double") {
out << "static constexpr " << cpp_type << " " << constant->GetName();
GenerateDeprecated(out, *constant);
out << " = " << constant->ValueString(ConstantValueDecorator) << ";\n";
} else {
out << "enum : " << cpp_type << " { " << constant->GetName();
GenerateDeprecated(out, *constant);
out << " = " << constant->ValueString(ConstantValueDecorator) << " };\n";
}
}
}
void GenerateServerTransaction(CodeWriter& out, const AidlInterface& interface,
const AidlMethod& method, const AidlTypenames& typenames,
const Options& options) {
const string bn_name = GetQualifiedName(interface, ClassNames::SERVER);
// Declare all the parameters now. In the common case, we expect no errors
// in serialization.
for (const unique_ptr<AidlArgument>& a : method.GetArguments()) {
out.Write("%s %s;\n", CppNameOf(a->GetType(), typenames).c_str(), BuildVarName(*a).c_str());
}
// Declare a variable to hold the return value.
if (method.GetType().GetName() != "void") {
out.Write("%s %s;\n", CppNameOf(method.GetType(), typenames).c_str(), kReturnVarName);
}
// Check that the client is calling the correct interface.
out.Write("if (!(%s.checkInterface(this))) {\n", kDataVarName);
out.Write(" %s = ::android::BAD_TYPE;\n", kAndroidStatusVarName);
out.Write(" break;\n");
out.Write("}\n");
if (options.GenTraces()) {
out.Write(
"::android::binder::ScopedTrace %s(ATRACE_TAG_AIDL, \"AIDL::cpp::%s::%s::cppServer\");\n",
kTraceVarName, interface.GetName().c_str(), method.GetName().c_str());
}
if (interface.EnforceExpression() || method.GetType().EnforceExpression()) {
out.Write("#error Permission checks not implemented for the cpp backend\n");
}
// Deserialize each "in" parameter to the transaction.
for (const auto& a: method.GetArguments()) {
// Deserialization looks roughly like:
// _aidl_ret_status = _aidl_data.ReadInt32(&in_param_name);
// if (_aidl_ret_status != ::android::OK) { break; }
const string& var_name = "&" + BuildVarName(*a);
if (a->IsIn()) {
out.Write("%s = %s.%s(%s);\n", kAndroidStatusVarName, kDataVarName,
ParcelReadMethodOf(a->GetType(), typenames).c_str(),
ParcelReadCastOf(a->GetType(), typenames, var_name).c_str());
GenerateBreakOnStatusNotOk(out);
} else if (a->IsOut() && a->GetType().IsDynamicArray()) {
// Special case, the length of the out array is written into the parcel.
// _aidl_ret_status = _aidl_data.resizeOutVector(&out_param_name);
// if (_aidl_ret_status != ::android::OK) { break; }
out.Write("%s = %s.resizeOutVector(%s);\n", kAndroidStatusVarName, kDataVarName,
var_name.c_str());
GenerateBreakOnStatusNotOk(out);
}
}
if (options.GenLog()) {
out << GenLogBeforeExecute(bn_name, method, true /* isServer */, false /* isNdk */);
}
if (!method.GetArguments().empty() && options.GetMinSdkVersion() >= SDK_VERSION_Tiramisu) {
out << "if (auto st = _aidl_data.enforceNoDataAvail(); !st.isOk()) {\n";
out << " _aidl_ret_status = st.writeToParcel(_aidl_reply);\n";
out << " break;\n";
out << "}\n";
}
// Call the actual method. This is implemented by the subclass.
out.Write("%s %s(%s(%s));\n", kBinderStatusLiteral, kStatusVarName, method.GetName().c_str(),
GenerateArgList(typenames, method, /*for_declaration=*/false, /*type_name_only=*/false)
.c_str());
if (options.GenLog()) {
out << GenLogAfterExecute(bn_name, interface, method, kStatusVarName, kReturnVarName,
true /* isServer */, false /* isNdk */);
}
// Write exceptions during transaction handling to parcel.
if (!method.IsOneway()) {
out.Write("%s = %s.writeToParcel(%s);\n", kAndroidStatusVarName, kStatusVarName, kReplyVarName);
GenerateBreakOnStatusNotOk(out);
out.Write("if (!%s.isOk()) {\n", kStatusVarName);
out.Write(" break;\n");
out.Write("}\n");
}
// If we have a return value, write it first.
if (method.GetType().GetName() != "void") {
out.Write("%s = %s->%s(%s);\n", kAndroidStatusVarName, kReplyVarName,
ParcelWriteMethodOf(method.GetType(), typenames).c_str(),
ParcelWriteCastOf(method.GetType(), typenames, kReturnVarName).c_str());
GenerateBreakOnStatusNotOk(out);
}
// Write each out parameter to the reply parcel.
for (const AidlArgument* a : method.GetOutArguments()) {
// Serialization looks roughly like:
// _aidl_ret_status = data.WriteInt32(out_param_name);
// if (_aidl_ret_status != ::android::OK) { break; }
out.Write("%s = %s->%s(%s);\n", kAndroidStatusVarName, kReplyVarName,
ParcelWriteMethodOf(a->GetType(), typenames).c_str(),
ParcelWriteCastOf(a->GetType(), typenames, BuildVarName(*a)).c_str());
GenerateBreakOnStatusNotOk(out);
}
}
void GenerateServerMetaTransaction(CodeWriter& out, const AidlInterface& interface,
const AidlMethod& method, const Options& options) {
AIDL_FATAL_IF(method.IsUserDefined(), method);
string iface = ClassName(interface, ClassNames::INTERFACE);
if (method.GetName() == kGetInterfaceVersion && options.Version() > 0) {
out << "_aidl_data.checkInterface(this);\n"
<< "_aidl_reply->writeNoException();\n"
<< "_aidl_reply->writeInt32(" << iface << "::VERSION);\n";
}
if (method.GetName() == kGetInterfaceHash && !options.Hash().empty()) {
out << "_aidl_data.checkInterface(this);\n"
<< "_aidl_reply->writeNoException();\n"
<< "_aidl_reply->writeUtf8AsUtf16(" << iface << "::HASH);\n";
}
}
} // namespace
void GenerateServerOnTransact(CodeWriter& out, const AidlInterface& interface,
const AidlTypenames& typenames, const Options& options) {
const string bn_name = ClassName(interface, ClassNames::SERVER);
const string q_name = GetQualifiedName(interface, ClassNames::SERVER);
bool deprecated = interface.IsDeprecated() ||
std::any_of(interface.GetMethods().begin(), interface.GetMethods().end(),
[](const auto& m) { return m->IsDeprecated(); });
if (deprecated) {
out << "#pragma clang diagnostic push\n";
out << "#pragma clang diagnostic ignored \"-Wdeprecated\"\n";
out << "\n";
}
out.Write("%s %s::onTransact(uint32_t %s, const %s& %s, %s* %s, uint32_t %s) {\n",
kAndroidStatusLiteral, q_name.c_str(), kCodeVarName, kAndroidParcelLiteral,
kDataVarName, kAndroidParcelLiteral, kReplyVarName, kFlagsVarName);
out.Indent();
// Declare the status_t variable
out.Write("%s %s = %s;\n", kAndroidStatusLiteral, kAndroidStatusVarName, kAndroidStatusOk);
// Add the all important switch statement
out.Write("switch (%s) {\n", kCodeVarName);
// The switch statement has a case statement for each transaction code.
for (const auto& method : interface.GetMethods()) {
out.Write("case %s:\n", GetTransactionIdFor(bn_name, *method).c_str());
out << "{\n";
out.Indent();
if (method->IsUserDefined()) {
GenerateServerTransaction(out, interface, *method, typenames, options);
} else {
GenerateServerMetaTransaction(out, interface, *method, options);
}
out.Dedent();
out << "}\n";
out << "break;\n";
}
// The switch statement has a default case which defers to the super class.
// The superclass handles a few pre-defined transactions.
out << "default:\n";
out << "{\n";
out.Write(" %s = ::android::BBinder::onTransact(%s, %s, %s, %s);\n", kAndroidStatusVarName,
kCodeVarName, kDataVarName, kReplyVarName, kFlagsVarName);
out << "}\n";
out << "break;\n";
out << "}\n"; // switch
// If we saw a null reference, we can map that to an appropriate exception.
out.Write("if (%s == ::android::UNEXPECTED_NULL) {\n", kAndroidStatusVarName);
out.Write(" %s = %s::fromExceptionCode(%s::EX_NULL_POINTER).writeOverParcel(%s);\n",
kAndroidStatusVarName, kBinderStatusLiteral, kBinderStatusLiteral, kReplyVarName);
out.Write("}\n");
// Finally, the server's onTransact method just returns a status code.
out.Write("return %s;\n", kAndroidStatusVarName);
out.Dedent();
out << "}\n";
out << "\n";
if (deprecated) {
out << "#pragma clang diagnostic pop\n";
out << "\n";
}
}
void GenerateServerSource(CodeWriter& out, const AidlInterface& interface,
const AidlTypenames& typenames, const Options& options) {
vector<string> include_list{
HeaderFile(interface, ClassNames::SERVER, false),
kParcelHeader,
kStabilityHeader,
};
if (options.GenLog()) {
include_list.emplace_back("chrono");
include_list.emplace_back("functional");
}
for (const auto& include : include_list) {
out << "#include <" << include << ">\n";
}
out << "\n";
const string i_name = ClassName(interface, ClassNames::INTERFACE);
const string bn_name = ClassName(interface, ClassNames::SERVER);
const string q_name = GetQualifiedName(interface, ClassNames::SERVER);
EnterNamespace(out, interface);
out << "\n";
// constructor
out.Write("%s::%s()\n", q_name.c_str(), bn_name.c_str());
out << "{\n";
out.Indent();
if (interface.IsVintfStability()) {
out << "::android::internal::Stability::markVintf(this);\n";
} else {
out << "::android::internal::Stability::markCompilationUnit(this);\n";
}
out.Dedent();
out << "}\n";
out << "\n";
GenerateServerOnTransact(out, interface, typenames, options);
if (options.Version() > 0) {
out << "int32_t " << q_name << "::" << kGetInterfaceVersion << "() {\n"
<< " return " << i_name << "::VERSION;\n"
<< "}\n";
}
if (!options.Hash().empty()) {
out << "std::string " << q_name << "::" << kGetInterfaceHash << "() {\n"
<< " return " << i_name << "::HASH;\n"
<< "}\n";
}
if (options.GenLog()) {
out << "std::function<void(const " + q_name + "::TransactionLog&)> " << q_name
<< "::logFunc;\n";
}
LeaveNamespace(out, interface);
}
void GenerateInterfaceSource(CodeWriter& out, const AidlInterface& interface,
const AidlTypenames& typenames, const Options&) {
out << "#include <" << HeaderFile(interface, ClassNames::RAW, false) << ">\n";
out << "#include <" << HeaderFile(interface, ClassNames::CLIENT, false) << ">\n";
EnterNamespace(out, interface);
if (auto parent = interface.GetParentType(); parent) {
out << fmt::format("DO_NOT_DIRECTLY_USE_ME_IMPLEMENT_META_NESTED_INTERFACE({}, {}, \"{}\")\n",
GetQualifiedName(*parent), ClassName(interface, ClassNames::BASE),
interface.GetDescriptor());
} else {
out << fmt::format("DO_NOT_DIRECTLY_USE_ME_IMPLEMENT_META_INTERFACE({}, \"{}\")\n",
ClassName(interface, ClassNames::BASE), interface.GetDescriptor());
}
GenerateConstantDefinitions(out, interface, typenames, /*template_decl=*/"",
ClassName(interface, ClassNames::INTERFACE));
LeaveNamespace(out, interface);
}
void GenerateClientClassDecl(CodeWriter& out, const AidlInterface& interface,
const AidlTypenames& typenames, const Options& options) {
const string bp_name = ClassName(interface, ClassNames::CLIENT);
const string iface = ClassName(interface, ClassNames::INTERFACE);
out << "class";
GenerateDeprecated(out, interface);
out << " " << bp_name << " : public ::android::BpInterface<" << iface << "> {\n";
out << "public:\n";
out.Indent();
out << "explicit " << bp_name << "(const ::android::sp<::android::IBinder>& " << kImplVarName
<< ");\n";
out << "virtual ~" << bp_name << "() = default;\n";
for (const auto& method : interface.GetMethods()) {
if (method->IsUserDefined()) {
GenerateMethodDecl(out, typenames, *method, /*clazz=*/"");
out << " override";
GenerateDeprecated(out, *method);
out << ";\n";
} else if (method->GetName() == kGetInterfaceVersion && options.Version() > 0) {
out << "int32_t " << method->GetName() << "() override;\n";
} else if (method->GetName() == kGetInterfaceHash && !options.Hash().empty()) {
out << "std::string " << method->GetName() << "() override;\n";
}
}
if (options.GenLog()) {
out << kTransactionLogStruct;
out << "static std::function<void(const TransactionLog&)> logFunc;\n";
}
out.Dedent();
if (options.Version() > 0 || !options.Hash().empty()) {
out << "private:\n";
out.Indent();
if (options.Version() > 0) {
out << "int32_t cached_version_ = -1;\n";
}
if (!options.Hash().empty()) {
out << "std::string cached_hash_ = \"-1\";\n";
out << "std::mutex cached_hash_mutex_;\n";
}
out.Dedent();
}
out << "}; // class " << bp_name << "\n";
}
void GenerateClientHeader(CodeWriter& out, const AidlInterface& interface,
const AidlTypenames& typenames, const Options& options) {
out << "#pragma once\n\n";
out << "#include <" << kIBinderHeader << ">\n";
out << "#include <" << kIInterfaceHeader << ">\n";
out << "#include <utils/Errors.h>\n";
out << "#include <" << HeaderFile(interface, ClassNames::RAW, false) << ">\n";
if (options.GenLog()) {
out << "#include <functional>\n"; // for std::function
out << "#include <android/binder_to_string.h>\n";
}
out << "\n";
EnterNamespace(out, interface);
GenerateClientClassDecl(out, interface, typenames, options);
LeaveNamespace(out, interface);
}
// Some interfaces are declared in .aidl files, but defined elsewhere.
// These interfaces can not have Delegators and need to be avoided.
// TODO(b/242920522) These should all be defined in .aidl files.
bool isKnownUndefinedInterface(const std::string& canonicalName) {
static const auto* kKnownUndefinedInterfaces = new std::set<std::string>{
"android.hardware.ICamera", "android.hardware.ICameraClient",
"android.IOMXNode", "android.IMediaExtractor",
"android.IDataSource",
};
return kKnownUndefinedInterfaces->find(canonicalName) != kKnownUndefinedInterfaces->end();
};
bool isDelegateable(const AidlTypeSpecifier& type) {
return type.GetDefinedType() && type.GetDefinedType()->AsInterface() &&
!isKnownUndefinedInterface(type.GetDefinedType()->GetCanonicalName()) && !type.IsArray();
}
void wrapDelegate(CodeWriter& out, const std::string& argName, const AidlTypeSpecifier& type,
bool in) {
const std::string argRef = in ? argName : "*" + argName;
const std::string targetArgName = in ? "_" + argName : argName;
const std::string targetArgRef = in ? targetArgName : "*" + targetArgName;
// input binders need local variables for each arg to pass to the delegate
// because the parameters are const
if (in) {
out << "::android::sp<::" << Join(type.GetSplitName(), "::") << "Delegator> " << targetArgName
<< ";\n";
}
out << "if (" << argRef << ") {\n";
out.Indent();
out << targetArgRef << " = ::android::sp<::" << Join(type.GetSplitName(), "::")
<< "Delegator>::cast(delegate(" << argRef << "));\n";
out.Dedent();
out << "}\n";
}
void GenerateServerClassDecl(CodeWriter& out, const AidlInterface& interface,
const AidlTypenames& typenames, const Options& options) {
const string bn_name = ClassName(interface, ClassNames::SERVER);
const string iface = ClassName(interface, ClassNames::INTERFACE);
out << "class";
GenerateDeprecated(out, interface);
out << " " << bn_name << " : public "
<< "::android::BnInterface<" << iface << "> {\n";
out << "public:\n";
out.Indent();
for (const auto& method : interface.GetMethods()) {
out << "static constexpr uint32_t TRANSACTION_" << method->GetName() << " = "
<< "::android::IBinder::FIRST_CALL_TRANSACTION + " << std::to_string(method->GetId())
<< ";\n";
}
out << "explicit " << bn_name << "();\n";
out << fmt::format("{} onTransact(uint32_t {}, const {}& {}, {}* {}, uint32_t {}) override;\n",
kAndroidStatusLiteral, kCodeVarName, kAndroidParcelLiteral, kDataVarName,
kAndroidParcelLiteral, kReplyVarName, kFlagsVarName);
if (options.Version() > 0) {
out << "int32_t " << kGetInterfaceVersion << "();\n";
}
if (!options.Hash().empty()) {
out << "std::string " << kGetInterfaceHash << "();\n";
}
if (options.GenLog()) {
out << kTransactionLogStruct;
out << "static std::function<void(const TransactionLog&)> logFunc;\n";
}
out.Dedent();
out << "}; // class " << bn_name << "\n\n";
std::string d_name = ClassName(interface, ClassNames::DELEGATOR_IMPL);
out << "class";
GenerateDeprecated(out, interface);
out << " " << d_name << " : public " << bn_name << " {\n";
out << "public:\n";
out.Indent();
out << "explicit " << d_name << "("
<< StringPrintf("const ::android::sp<%s> &impl", iface.c_str()) << ") "
<< StringPrintf(": %s(impl)", kDelegateImplVarName) << " {}\n\n";
out << "::android::sp<" << iface << "> getImpl() { return " << kDelegateImplVarName << "; }\n";
for (const auto& method : interface.GetMethods()) {
if (method->IsUserDefined()) {
GenerateMethodDecl(out, typenames, *method, /*clazz=*/"");
out << " override";
GenerateDeprecated(out, *method);
std::vector<std::string> args;
// arg name, type
std::vector<pair<const std::string, const AidlTypeSpecifier&>> outBinders;
std::vector<pair<const std::string, const AidlTypeSpecifier&>> inBinders;
for (const auto& arg : method->GetArguments()) {
if (isDelegateable(arg->GetType())) {
if (arg->IsOut()) {
outBinders.push_back({arg->GetName(), arg->GetType()});
} else if (arg->IsIn()) {
inBinders.push_back({arg->GetName(), arg->GetType()});
} else {
AIDL_FATAL(*arg) << "inout interface?";
}
AIDL_FATAL_IF(!arg->IsIn() && !arg->IsOut(), *arg) << "Not in or out?";
args.push_back("_" + arg->GetName());
} else {
if (IsNonCopyableType(arg->GetType(), typenames)) {
args.push_back(StringPrintf("std::move(%s)", arg->GetName().c_str()));
} else {
args.push_back(arg->GetName());
}
}
}
if (method->GetType().GetName() != "void") {
if (isDelegateable(method->GetType())) {
outBinders.push_back({kReturnVarName, method->GetType()});
}
args.push_back(kReturnVarName);
}
out << " {\n";
out.Indent();
for (const auto binder : inBinders) {
wrapDelegate(out, binder.first, binder.second, true);
}
if (outBinders.empty()) {
out << "return " << kDelegateImplVarName << "->" << method->GetName() << "("
<< base::Join(args, ", ") << ");\n";
} else {
out << "auto _status = " << kDelegateImplVarName << "->" << method->GetName() << "("
<< base::Join(args, ", ") << ");\n";
for (const auto& binder : outBinders) {
wrapDelegate(out, binder.first, binder.second, false);
}
out << "return _status;\n";
}
out.Dedent();
out << "}\n";
} else if (method->GetName() == kGetInterfaceVersion && options.Version()) {
out << "int32_t " << kGetInterfaceVersion << "()"
<< " override {\n";
out.Indent();
out << "int32_t _delegator_ver = " << bn_name << "::" << kGetInterfaceVersion << "();\n";
out << "int32_t _impl_ver = " << kDelegateImplVarName << "->" << kGetInterfaceVersion
<< "();\n";
out << "return _delegator_ver < _impl_ver ? _delegator_ver : _impl_ver;\n";
out.Dedent();
out << "}\n";
} else if (method->GetName() == kGetInterfaceHash && !options.Hash().empty()) {
out << "std::string " << kGetInterfaceHash << "()"
<< " override {\n";
out << " return " << kDelegateImplVarName << "->" << kGetInterfaceHash << "();\n";
out << "}\n";
}
}
out.Dedent();
out << "private:\n";
out.Indent();
out << "::android::sp<" << iface << "> " << kDelegateImplVarName << ";\n";
out.Dedent();
out << "}; // class " << d_name << "\n";
}
// Collect all includes for the type's server header. Nested types are visited as well via
// VisitTopDown.
void GenerateServerHeaderIncludes(CodeWriter& out, const AidlDefinedType& defined_type,
const AidlTypenames& typenames, const Options& options) {
struct Visitor : AidlVisitor {
const AidlTypenames& typenames;
const Options& options;
std::set<std::string> includes;
Visitor(const AidlTypenames& typenames, const Options& options)
: typenames(typenames), options(options) {}
// Collect includes for each type reference
void Visit(const AidlTypeSpecifier& type) override {
// Add Bn* header files for types used in this header. The *Delegator
// definitions require them.
const auto defined_type = type.GetDefinedType();
if (defined_type && defined_type->AsInterface()) {
if (!isKnownUndefinedInterface(defined_type->GetCanonicalName())) {
includes.insert(HeaderFile(*defined_type, ClassNames::SERVER, /*use_os_sep=*/false));
}
}
}
// Collect implementation-specific includes for each type definition
void Visit(const AidlInterface& iface) override {
includes.insert(HeaderFile(iface, ClassNames::SERVER, false));
}
} v(typenames, options);
VisitTopDown(v, defined_type);
v.includes.insert(kBinderDelegateHeader);
for (const auto& path : v.includes) {
out << "#include <" << path << ">\n";
}
out << "\n";
}
void GenerateServerHeader(CodeWriter& out, const AidlInterface& interface,
const AidlTypenames& typenames, const Options& options) {
out << "#pragma once\n\n";
out << "#include <binder/IInterface.h>\n";
out << "#include <" << HeaderFile(interface, ClassNames::RAW, false) << ">\n";
if (options.GenLog()) {
out << "#include <functional>\n"; // for std::function
out << "#include <android/binder_to_string.h>\n";
}
GenerateServerHeaderIncludes(out, interface, typenames, options);
out << "\n";
EnterNamespace(out, interface);
GenerateServerClassDecl(out, interface, typenames, options);
LeaveNamespace(out, interface);
}
void GenerateClassDecl(CodeWriter& out, const AidlDefinedType& defined_type,
const AidlTypenames& typenames, const Options& options);
void GenerateNestedTypeDecls(CodeWriter& out, const AidlDefinedType& type,
const AidlTypenames& typenames, const Options& options) {
auto visit = [&](const auto& nested) { GenerateClassDecl(out, nested, typenames, options); };